Patent Description:
Patent Document <NUM> discloses that "a method for updating an ion exchange membrane according to the present embodiment includes a step of sandwiching the ion exchange membrane between an anode-side gasket and a cathode-side gasket,. " (paragraph <NUM>). Further, Patent Document 2describes a method for determining the optimal operation period of an ionic membrane electrolytic cell comprising the following specific steps: obtaining power consumption for per ton of alkali during initial operation of an ionic membrane; obtaining the power consumption for per ton of alkali when the ionic membrane runs for N years; obtaining an increment of the power consumption for per ton of alkali when the ionic membrane runs for N years or comprehensive cost at the N year; and, when the increment of the power consumption for per ton of alkali or the comprehensive cost is equal to membrane replacement cost, taking the operation age limit of the ionic membrane as the optimal operation period. The ionic membrane is determined to be replaced by calculating the optimal membrane replacement period and taking actual operation process and other factors into consideration, so management is optimized, and cost is reduced.

In an electrolytic apparatus including an ion exchange membrane or the like, when the performance of the ion exchange membrane or the like deteriorates, the production efficiency of the product produced by the electrolytic apparatus is likely to be reduced. Therefore, it is desirable that the ion exchange membrane with deteriorated performance is replaced. On the other hand, when the ion exchange membrane is replaced, the functioning of the electrolytic apparatus may be stopped. When the functioning of the electrolytic apparatus is stopped, the product is not produced during the stopped period, so that the production amount of the product is smaller than that when the functioning of the electrolytic apparatus is not stopped. Therefore, it is preferable that the replacement of the ion exchange membrane is performed at timing when a cost related to the functioning of the electrolytic apparatus is minimized.

In a production plan of the product produced by the electrolytic apparatus, the production amount of the product may depend on the moment. Therefore, it is preferable that the replacement of the ion exchange membrane is performed at a moment when the production plan of the product can be satisfied. Therefore, it is desirable that the operation assistance apparatus which assists the operation of the electrolytic apparatus can specify the replacing moment of the ion exchange membrane at which the production plan of the product can be satisfied while the total cost associated with the functioning of the electrolytic apparatus is reduced as much as possible.

A first aspect of the present invention provides an operation assistance apparatus. The operation assistance apparatus includes the features of claim <NUM>.

The plurality of electrolyzers each may include an anode chamber and a cathode chamber partitioned by the ion exchange membrane. An aqueous solution of an alkali metal chloride may be introduced into the anode chamber, and an aqueous solution of an alkali metal hydroxide may be discharged from the cathode chamber. The operation assistance apparatus may further include: a current calculation unit which calculates current which is supplied to each of the plurality of electrolyzers and at which a production amount of the product produced in the period by the plurality of electrolyzers is maximized, a power amount consumed in the period by the plurality of electrolyzers is minimized, mass of an alkali metal chloride, which is introduced into the anode chamber and is contained in the aqueous solution of the alkali metal hydroxide discharged from the cathode chamber, is minimized, or mass of oxygen contained in chlorine discharged from the anode chamber is minimized; and a current supply unit which supplies the current calculated by the current calculation unit to each of the plurality of electrolyzers.

The operation assistance apparatus may further include a power amount acquisition unit. The power amount acquisition unit may acquire a power amount for each of the plurality of electrolyzers to produce the product. The current calculation unit may calculate current at which the production amount of the product is maximized or the mass of the alkali metal chloride or the mass of the oxygen is minimized when the power amount is less than a predetermined power amount.

The operation assistance apparatus may further include an electrolyzer specification unit which specifies an electrolyzer, of which the power amount is maximum, among the plurality of electrolyzers.

The electrolyzer specification unit may specify the electrolyzer, of which the power amount is maximum, when the power amount in total in the predetermined period is minimum.

The operation assistance apparatus may further include an electrolyzer specification unit which specifies an electrolyzer, of which current efficiency of the electrolyzer is the lowest, among the plurality of electrolyzers.

The current calculation unit may calculate current at which the production amount of the product is maximized or the power amount is minimized when the mass of the alkali metal chloride or the mass of the oxygen is at less than a predetermined concentration.

The current calculation unit may calculate the current, at which a total production amount of the product by the plurality of electrolyzers in the predetermined period is maximized, supplied to each of the plurality of electrolyzers.

The operation assistance apparatus may further include an electrolyzer specification unit. The production amount acquisition unit may further acquire a production amount of the product produced in the period by each of the plurality of electrolyzers. The production amount calculation unit may further calculate the production amount of the product produced in the period by each of the plurality of electrolyzers. The electrolyzer specification unit may specify an electrolyzer, of which the ion exchange membrane is to be updated, among the plurality of electrolyzers on a basis of the production amount of the product acquired by the production amount acquisition unit and the production amount of the product calculated by the production amount calculation unit.

The electrolyzer specification unit may specify an electrolyzer, in which the production amount of the product acquired by the production amount acquisition unit is minimum, among the plurality of electrolyzers.

An aqueous solution of an alkali metal chloride may be discharged from the anode chamber. The operation assistance apparatus may further include a pH acquisition unit which acquires a pH of the aqueous solution of the alkali metal chloride introduced into the anode chamber and a pH of the aqueous solution of the alkali metal chloride discharged from the anode chamber. The electrolyzer specification unit may specify an electrolyzer, of which the ion exchange membrane is to be updated, among the plurality of electrolyzers on the basis of the pH of the aqueous solution of the alkali metal chloride acquired by the pH acquisition unit.

The operation assistance apparatus may further include a deterioration speed acquisition unit which acquires a deterioration speed of the ion exchange membrane in each of the plurality of electrolyzers. The electrolyzer specification unit may specify an electrolyzer, of which the ion exchange membrane is to be updated, among the plurality of electrolyzers on the basis of the deterioration speed of the ion exchange membrane.

When a deterioration speed of one ion exchange membrane among ion exchange membranes including the ion exchange membrane in each of the plurality of electrolyzers is equal to or higher than a predetermined deterioration speed, the electrolyzer specification unit may specify the electrolyzer having the one ion exchange membrane.

The production amount calculation unit may further calculate a maximum production amount of the product when the one ion exchange membrane specified by the electrolyzer specification unit is updated. The period specification unit may further specify the period during which the maximum production amount becomes equal to or more than the target production amount.

The alkali metal chloride may be a sodium chloride or a potassium chloride. When the alkali metal chloride is a sodium chloride, the alkali metal hydroxide may be a sodium hydroxide. When the alkali metal chloride is a potassium chloride, the alkali metal hydroxide may be a potassium hydroxide.

A second aspect of the present invention provides an operation assistance system. The operation assistance system includes: the operation assistance apparatus; and the one electrolyzer or the plurality of electrolyzers.

A third aspect of the present invention provides an operation assistance method as defined in claim <NUM>.

A fourth aspect of the present invention provides an operation assistance program as defined in claim <NUM>.

Hereinafter, the present invention will be described through embodiments of the present invention, but the following embodiments do not limit the present invention according to claims. In addition, not all of the combinations of features described in the embodiments are essential to the solving means of the invention.

<FIG> is a view illustrating an example of an electrolytic apparatus <NUM> according to one embodiment of the present invention. The electrolytic apparatus <NUM> of the present example includes a plurality of electrolyzers <NUM> (electrolyzers <NUM>-<NUM> to <NUM>-M, where M is an integer of <NUM> or more). The electrolyzer <NUM> is a tank for electrolyzing an electrolytic solution. The electrolytic apparatus <NUM> of the present example includes an introduction tube <NUM>, an introduction tube <NUM>, a discharge tube <NUM>, and a discharge tube <NUM>. The introduction tube <NUM> and the introduction tube <NUM> are connected to each of the plurality of electrolyzers <NUM>. The discharge tube <NUM> and the discharge tube <NUM> are connected to each of the plurality of electrolyzers <NUM>.

Liquid <NUM> is introduced into each of the plurality of electrolyzers <NUM>. The liquid <NUM> may be introduced into each of the plurality of electrolyzers <NUM> after passing through the introduction tube <NUM>. The liquid <NUM> is an aqueous solution of an alkali metal chloride. The alkali metal is an element belonging to group <NUM> of the periodic table of the elements. The liquid <NUM> may be an aqueous NaCl (sodium chloride) solution or an aqueous KCI (potassium chloride) solution. Liquid <NUM> is introduced into each of the plurality of electrolyzers <NUM>. The liquid <NUM> may be introduced into each of the plurality of electrolyzers <NUM> after passing through the introduction tube <NUM>. The liquid <NUM> is an aqueous solution of an alkali metal hydroxide. When the liquid <NUM> is an aqueous NaCl (sodium chloride) solution, the liquid <NUM> is an aqueous NaOH (sodium hydroxide) solution. When the liquid <NUM> is an aqueous KCI (potassium chloride) solution, the liquid <NUM> is an aqueous KOH (potassium hydroxide) solution.

Liquid <NUM> and gas <NUM> (described later) are discharged from each of the plurality of electrolyzers <NUM>. The liquid <NUM> and the gas <NUM> (described later) may be discharged to the outside of the electrolytic apparatus <NUM> after passing through the discharge tube <NUM>. The liquid <NUM> is an aqueous solution of an alkali metal hydroxide. When the liquid <NUM> is an aqueous NaCl (sodium chloride) solution, the liquid <NUM> is an aqueous NaOH (sodium hydroxide) solution. When the liquid <NUM> is an aqueous KCl (potassium chloride) solution, the liquid <NUM> is an aqueous KOH (potassium hydroxide) solution. In the present example, the gas <NUM> (described later) is H<NUM> (hydrogen).

Liquid <NUM> and gas <NUM> (described later) are discharged from each of the plurality of electrolyzers <NUM>. The liquid <NUM> and the gas <NUM> (described later) may be discharged to the outside of the electrolytic apparatus <NUM> after passing through the discharge tube <NUM>. The liquid <NUM> is an aqueous solution of an alkali metal chloride. When the liquid <NUM> is an aqueous NaCl (sodium chloride) solution, the liquid <NUM> is an aqueous NaCl (sodium chloride) solution. When the liquid <NUM> is an aqueous KCI (potassium chloride) solution, the liquid <NUM> is an aqueous KCl (potassium chloride) solution. In the present example, the gas <NUM> (described later) is Cl<NUM> (chlorine).

In the present example, the plurality of electrolyzers <NUM> are arranged in a predetermined direction. In the present specification, the predetermined arrangement direction of the plurality of electrolyzers <NUM> is defined as an X-axis direction. In the present specification, a direction orthogonal to the X-axis direction and directed from introduction tube <NUM> to the discharge tube <NUM> is defined as a Z axis. In the present specification, a direction orthogonal to the X axis and orthogonal to a Z-axis direction is defined as a Y axis. The Z-axis direction may be parallel to a vertical direction, and an XY plane may be a horizontal plane.

<FIG> is a view of the electrolytic apparatus <NUM> illustrated in <FIG> as viewed from the X-axis direction. In <FIG>, the electrolyzer <NUM>-M will be described as an example. One electrolyzer <NUM> may include a plurality of electrolysis cells <NUM> (electrolysis cells <NUM>-<NUM> to <NUM>-N, where N is an integer of <NUM> or more). N is, for example, <NUM>. In the present example, each of the electrolyzers <NUM>-<NUM> to <NUM>-M includes a plurality of electrolysis cells <NUM>.

The introduction tube <NUM> and introduction tube <NUM> are connected to each of the electrolysis cells <NUM>-<NUM> to <NUM>-N. The liquid <NUM> is introduced into each of the electrolysis cells <NUM>-<NUM> to <NUM>-N. The liquid <NUM> may be introduced into each of the electrolysis cells <NUM>-<NUM> to <NUM>-N after passing through the introduction tube <NUM>. The liquid <NUM> is introduced into each of the electrolysis cells <NUM>-<NUM> to <NUM>-N. The liquid <NUM> may be introduced into each of the electrolysis cells <NUM>-<NUM> to <NUM>-N after passing through the introduction tube <NUM>.

The discharge tube <NUM> and the discharge tube <NUM> are connected to each of the electrolysis cells <NUM>-<NUM> to <NUM>-N. The liquid <NUM> and the gas <NUM> (described later) are discharged from each of the electrolysis cells <NUM>-<NUM> to <NUM>-N. The liquid <NUM> and the gas <NUM> (described later) may be discharged to the outside of the electrolytic apparatus <NUM> after passing through the discharge tube <NUM>. The liquid <NUM> and the gas <NUM> (described later) are discharged from each of the electrolysis cells <NUM>-<NUM> to <NUM>-N. The liquid <NUM> and the gas <NUM> (described later) may be discharged to the outside of the electrolytic apparatus <NUM> after passing through the discharge tube <NUM>.

<FIG> is a view illustrating an example of details of one electrolysis cell <NUM> in <FIG>. The electrolysis cell <NUM> of the present example includes an anode <NUM>, a cathode <NUM>, and an ion exchange membrane <NUM>. The electrolysis cell <NUM> has an anode chamber <NUM> and a cathode chamber <NUM> partitioned by the ion exchange membrane <NUM>. The anode <NUM> is arranged in the anode chamber <NUM>. The cathode <NUM> is arranged in the cathode chamber <NUM>. The introduction tube <NUM> and the discharge tube <NUM> are connected to the anode chamber <NUM>. The introduction tube <NUM> and the discharge tube <NUM> are connected to the cathode chamber <NUM>.

The ion exchange membrane <NUM> is a membranous substance that prevents passage of ions having the same sign as the ions arranged in the ion exchange membrane <NUM> and allows passage of only ions having different signs. In the present example, the ion exchange membrane <NUM> is a cation exchange membrane that prevents passage of ions (that is, anions) having the same sign as the anions (an anion group <NUM> to be described later) arranged in the ion exchange membrane <NUM> and allows passage of only ions (that is, cations) having different signs. When the liquid <NUM> is an aqueous NaCl (sodium chloride) solution and the liquid <NUM> is an aqueous solution of an alkali metal hydroxide, the ion exchange membrane <NUM> is a membrane that allows Na+ (sodium ion) to pass therethrough and prevents OH- (hydroxide ion) and Cl- (chloride ion) from passing therethrough.

The anode <NUM> and the cathode <NUM> may be maintained at predetermined positive and negative potentials, respectively. The liquid <NUM> introduced into the anode chamber <NUM> and the liquid <NUM> introduced into the cathode chamber <NUM> are electrolyzed by a potential difference between the anode <NUM> and the cathode <NUM>. In the anode <NUM>, the following chemical reaction occurs.

(Chemical Formula <NUM>)     2Cl- → Cl<NUM> + 2e-.

When the liquid <NUM> is an aqueous NaCl (sodium chloride) solution, NaCl (sodium chloride) is ionized into Na+ (sodium ion) and Cl- (chloride ion). In the anode <NUM>, chlorine gas (Cl<NUM>) is generated by the chemical reaction represented by Chemical Formula <NUM>. Na+ (sodium ions) moves from the anode chamber <NUM> to the cathode chamber <NUM> via the ion exchange membrane <NUM> by an attractive force from the cathode <NUM>.

In the anode chamber <NUM>, liquid <NUM> may be retained. The liquid <NUM> is an aqueous solution of an alkali metal chloride. In the present example, the liquid <NUM> is defined to be an aqueous NaCl (sodium chloride) solution. The Na+ (sodium ion) concentration and the Cl- (chloride ion) concentration of the liquid <NUM> may be less than the Na+ (sodium ion) concentration and the Cl- (chloride ion) concentration of the liquid <NUM>.

In the cathode <NUM>, the following chemical reaction occurs.

(Chemical Formula <NUM>)     <NUM><NUM>O + 2e- → H<NUM> + 2OH-.

Liquid <NUM> may be retained in the cathode chamber <NUM>. The liquid <NUM> is an aqueous solution of an alkali metal hydroxide. In the present example, the liquid <NUM> is an aqueous NaOH (sodium hydroxide) solution. In the present example, in the cathode <NUM>, hydrogen gas (H<NUM>) and hydroxide ions (OH-) are generated by the chemical reaction represented by Chemical Formula <NUM>. In the present example, the liquid <NUM> in which hydroxide ions (OH-) generated by the chemical reaction represented by Chemical Formula <NUM> and Na+ (sodium ions) moved from the anode chamber <NUM> are dissolved is retained in the cathode chamber <NUM>.

<FIG> is an enlarged view of the vicinity of the ion exchange membrane <NUM> in the electrolysis cell <NUM> illustrated in <FIG>. The anion group <NUM> is fixed to the ion exchange membrane <NUM> of the present example. Since anions are repelled by the anion group <NUM>, the anions hardly pass through the ion exchange membrane <NUM>. In the present example, the anions are Cl- (chloride ion). Since cations <NUM> are not repelled by the anion group <NUM>, the cations can pass through the ion exchange membrane <NUM>. In the present example, the cations <NUM> are Na+ (sodium ion).

<FIG> is a diagram illustrating an example of a block diagram of an operation assistance apparatus <NUM> according to one embodiment of the present invention. The operation assistance apparatus <NUM> assists the operation of the electrolytic apparatus <NUM> (see <FIG>). The operation assistance apparatus <NUM> includes a production amount acquisition unit <NUM>, a production amount calculation unit <NUM>, a period specification unit <NUM>, and a control unit <NUM>. The period specification unit <NUM> will be described later. The operation assistance apparatus <NUM> may include an input unit <NUM>, a display unit <NUM>, and a cost calculation unit <NUM>. In addition, the control unit <NUM> may include a display control unit that controls the display unit <NUM>.

The operation assistance apparatus <NUM> is, for example, a computer including a CPU, a memory, an interface, and the like. The control unit <NUM> may be the CPU.

The production amount acquisition unit <NUM> acquires a target production amount of a product produced in a predetermined period by one or more electrolyzers <NUM> (see <FIG>). The product is defined as a product P. In the present example, the product P is at least one of NaOH (sodium hydroxide) or Cl<NUM> (chlorine). The predetermined period may be a period based on the production plan of the product. The predetermined period is defined as a period T. The target production amount of the product P may be a lower limit production amount of the product P in the period T. The production amount and the target production amount of the product P are defined as a production amount Pa and a target production amount Pg, respectively.

The production amount Pa in each electrolyzer <NUM> can be calculated by following Formula <NUM>. (Mathematical formula <NUM>) <MAT>.

A is a constant. When the product P is NaCl (sodium chloride), A is, for example, <NUM>. When the product P is KCI (potassium chloride), A is, for example, <NUM>.

In Formula <NUM>, le represents current in one electrolyzer <NUM>, CE represents current efficiency (described later) in one electrolyzer <NUM>, and n represents the number of the electrolysis cells <NUM> in the electrolyzer <NUM>. In the example of <FIG>, n = M. The current le can be obtained from an integrated production control system (DCS: Distributed Control System) that controls the electrolytic apparatus <NUM>. The current efficiency CE can be calculated from the current le, the number n of the electrolysis cells <NUM> in the electrolyzer <NUM>, the oxygen concentration in the chlorine gas to be generated, the acidity of the aqueous solution (the liquid <NUM> in <FIG>) of the alkali metal chloride supplied to the anode chamber <NUM>, the acidity of the aqueous solution (the liquid <NUM> in <FIG>) of the alkali metal chloride released from the anode chamber <NUM>, the generation amount of ClO- (hypochlorite ion), and the generation amount of ClO<NUM>- (chlorate ion).

The current efficiency CE can be calculated by subtracting, from <NUM>%, a loss due to an acidity difference between the acidity of the liquid <NUM> supplied to the anode chamber <NUM> and the acidity of the liquid <NUM> released from the anode chamber <NUM> (CEHCl), a loss of the current efficiency CE due to O<NUM> (oxygen) generation (CEO2), a loss of the current efficiency CE due to ClO- (hypochlorite ion) generation (CEClO), and a loss of the current efficiency CE due to ClO<NUM>- (chlorate ion) generation (CEClO3). (Mathematical formula <NUM>) <MAT> <MAT> In Formula <NUM>-<NUM>, F is a Faraday constant (= <NUM> A·hr/mol).

In Formula <NUM>-<NUM>, AC (mol/hr) is an acidity difference between the acidity of the aqueous solution (the liquid <NUM> in <FIG>) of the alkali metal chloride supplied to the anode chamber <NUM> and the acidity of the aqueous solution (the liquid <NUM> in <FIG>) of the alkali metal chloride released from the anode chamber <NUM>.

The acidity of the aqueous solution (the liquid <NUM> in <FIG>) of the alkali metal chloride supplied to the anode chamber <NUM> is denoted by Dh1, and the acidity of the aqueous solution (the liquid <NUM> in <FIG>) of the alkali metal chloride released from the anode chamber <NUM> is denoted by Dh2. A flow rate of the aqueous solution (the liquid <NUM> in <FIG>) of the alkali metal chloride supplied to the anode chamber <NUM> is denoted by V (L/hr), and a flow rate of the aqueous solution (the liquid <NUM> in <FIG>) of the alkali metal chloride released from the anode chamber <NUM> is denoted by V" (L/hr). AC in Formula <NUM>-<NUM> is expressed by following Formula <NUM>. (Mathematical formula <NUM>) <MAT>.

When the concentration of O<NUM> (oxygen) contained in chlorine (Cl2) (the gas <NUM> in <FIG>) is denoted by Do, the loss of the current efficiency CE due to O<NUM> (oxygen) generation (CEO2) in Formula <NUM>-<NUM> is expressed by following Formula <NUM>. (Mathematical formula <NUM>) <MAT>.

When the molar concentration of ClO- (hypochlorite ions) in the aqueous solution (the liquid <NUM> in <FIG>) of the alkali metal chloride supplied to the anode chamber <NUM> is denoted by Dm1, and the molar concentration of ClO- (hypochlorite ions) in the aqueous solution (the liquid <NUM> in <FIG>) of the alkali metal chloride released from the anode chamber <NUM> is denoted by Dm2, the loss of the current efficiency CE due to ClO- (hypochlorite ions) generation (CEClO) in Formula <NUM>-<NUM> is expressed by following Formula <NUM>. (Mathematical formula <NUM>) <MAT>.

When the molar concentration of ClO<NUM>- (chlorate ions) in the aqueous solution (the liquid <NUM> in <FIG>) of the alkali metal chloride supplied to the anode chamber <NUM> is denoted by Dm1', and the molar concentration of ClO<NUM>- (chlorate ions) in the aqueous solution (the liquid <NUM> in <FIG>) of the alkali metal chloride released from the anode chamber <NUM> is denoted by Dm2', the loss of the current efficiency CE due to ClO<NUM>- (chlorate ions) generation (CEClO3) in Formula <NUM>-<NUM> is expressed by following Formula <NUM>. (Mathematical formula <NUM>) <MAT>.

The target production amount Pg may be input by the input unit <NUM>. A user of the operation assistance apparatus <NUM> may input the target production amount Pg through the input unit <NUM>. The input unit <NUM> is, for example, a keyboard, a mouse, or the like.

The production amount calculation unit <NUM> calculates a maximum production amount (a post-update maximum production amount (production amount Pm2) to be described later) of the product P when the ion exchange membrane <NUM> (see <FIG> and <FIG>) is updated. The maximum production amount is the maximum production amount of the product P produced by the electrolyzer <NUM> in the period T. The maximum production amount is defined as a maximum production amount Pm. Note that the production amount calculation unit <NUM> may calculate the maximum production amount of the product P when a member, which is a member of the electrolyzer <NUM> (see <FIG> and <FIG>), other than the ion exchange membrane <NUM> is updated.

A case where the ion exchange membrane <NUM> has been updated is, for example, a case where, when the performance of the ion exchange membrane <NUM> has deteriorated, the ion exchange membrane <NUM> having deteriorated performance has been updated to a new ion exchange membrane <NUM>. Updating the ion exchange membrane <NUM> having deteriorated performance to a new ion exchange membrane <NUM> may refer to replacing the ion exchange membrane <NUM> having deteriorated performance with the ion exchange membrane <NUM> having a new electrolyzer <NUM>.

As described above, the ion exchange membrane <NUM> repels anions by the anion group <NUM>. The performance of the ion exchange membrane <NUM> refers to the ability of the ion exchange membrane <NUM> to repel anions by the anion group <NUM>. A case where the performance of the ion exchange membrane <NUM> has deteriorated refers to a case where the ability of the ion exchange membrane <NUM> to repel the anion group <NUM> has deteriorated due to attachment of the impurity of the cations to the anion group <NUM> as compared with a case where the impurity of the cations is not attached to the anion group <NUM>. The performance of the ion exchange membrane <NUM> is likely to deteriorate with the functioning time of the electrolyzer <NUM> (see <FIG> and <FIG>).

The maximum production amount refers to the production amount Pa at which the electrolytic apparatus <NUM> can theoretically produce the product P. In the present example, the maximum production amount is calculated from maximum current and current efficiency in each of the plurality of electrolyzers <NUM>. The maximum current and the current efficiency may be the maximum value and the current efficiency of the current measured when the electrolytic apparatus <NUM> is functioning. For example, the maximum current is <NUM> kA. Here, the current efficiency refers to a ratio of an actual production amount to the theoretical production amount Pa of the product P.

The calculated maximum production amount Pm may be displayed on the display unit <NUM>. The display unit <NUM> is, for example, a display, a monitor, or the like.

The cost calculation unit <NUM> calculates a cost related to the functioning of one or more electrolyzers <NUM>. The cost is defined as a cost C. The cost C includes an electricity cost for functioning of the electrolytic apparatus <NUM> (see <FIG> and <FIG>), and an unredeemed cost of the ion exchange membrane <NUM> when the ion exchange membrane <NUM> is replaced before the performance of the ion exchange membrane <NUM> completely deteriorates.

The electricity cost for functioning of the electrolytic apparatus <NUM> can be calculated by multiplying the electricity cost per unit power consumption amount by a power consumption amount in each electrolyzer <NUM>. The power consumption amount can be calculated by a product of a cell voltage CV (described later) of the electrolyzer <NUM>, the current flowing through the electrolyzer <NUM>, and a functioning time. When the electricity cost is an electricity cost per day, the functioning time may be <NUM> hours. The electricity cost for functioning of the electrolytic apparatus <NUM> may be the total electricity cost of the plurality of electrolyzers <NUM>.

The cost C may further include at least one of the maintenance cost of the electrolytic apparatus <NUM>, an opportunity loss cost, or a purchase cost of a new ion exchange membrane <NUM> when the ion exchange membrane <NUM> is updated. When the ion exchange membrane <NUM> is updated, a period during which the electrolytic apparatus <NUM> cannot function may occur. The opportunity loss cost refers to a profit of the product P that would have been obtained if the electrolytic apparatus <NUM> had been continuously functioned when a period during which the electrolytic apparatus <NUM> cannot function has occurred.

<FIG> is a diagram illustrating an example of a relationship between a time period t and the production amount Pa and an example of a relationship between the time period t and the cost C. In <FIG>, the target production amount is indicated by a thick solid line, the total cost is indicated by a two-dot chain line, a pre-update maximum production amount is indicated by a one-dot chain line, and a post-update maximum production amount is indicated by a rough broken line. The pre-update maximum production amount is the maximum production amount Pm of the product P by the electrolyzer <NUM> when the ion exchange membrane <NUM> is not updated. The pre-update maximum production amount is defined as a production amount Pm1. The post-update maximum production amount is the maximum production amount Pm of the product P by the electrolyzer <NUM> when the ion exchange membrane <NUM> is updated. The post-update maximum production amount is defined as a production amount Pm2.

When the ion exchange membrane <NUM> is updated, the functioning of the electrolytic apparatus <NUM> can be temporarily stopped. Therefore, with the update of the ion exchange membrane <NUM>, a time period during which the electrolyzer <NUM> cannot function may occur. Therefore, the production amount Pm2 is likely to be smaller than the production amount Pm1. The production amount Pm2 is equal to the production amount Pa obtained by subtracting, from the production amount Pm1, the production amount that could have been produced if the electrolyzer <NUM> could have functioned. Note that as described above, the performance of the ion exchange membrane <NUM> is likely to deteriorate with the functioning time of the electrolyzer <NUM> (see <FIG> and <FIG>), and thus the production amount Pm1 and the production amount Pm2 are likely to be reduced with the lapse of the time period t.

A period T from time zero to time t1 is defined as a period T1. A period T from time t1 to time t2 is defined as a period T2. A period T from time t2 to time t3 is defined as a period T3. A period T from time t3 to time t4 is defined as a period T4. In the present example, a plurality of periods T described above include the period T1 to the period T4. The period T1 is, for example, one month, and the period T2 to the period T4 are, for example, two months.

The target production amount Pg in the period T1 is defined as a target production amount Pg1. The target production amount Pg in the period T2 and the period T4 is defined as a target production amount Pg2. The target production amount Pg in the period T3 is defined as a target production amount Pg3. In the present example, the target production amount Pg2 is larger than the target production amount Pg1, and the target production amount Pg3 is smaller than the target production amount Pg1.

The period specification unit <NUM> (see <FIG>) specifies the period T during which the maximum production amount Pm (production amount Pm2) of the product P when the ion exchange membrane <NUM> is updated becomes equal to or more than the target production amount Pg. In the present example, the period specification unit <NUM> specifies at least one of the period T1 or the period T3. In the present example, the production amount Pm1 is larger than the target production amount Pg in the period T1 to the period T4. However, in the present example, the production amount Pm2 is smaller than the target production amount Pg in the period T2 and the period T4. Therefore, in the present example, when the ion exchange membrane <NUM> is updated, the electrolytic apparatus <NUM> (see <FIG> and <FIG>) cannot produce the product P of the target production amount Pg in the period T2 and the period T4. In <FIG>, the period T2 and the period T4 are indicated by hatching. In the present example, when the ion exchange membrane <NUM> is updated, the electrolytic apparatus <NUM> (see <FIG> and <FIG>) can produce the product P of the target production amount Pg in the period T1 and the period T3.

In the operation assistance apparatus <NUM>, the period specification unit <NUM> (see <FIG>) specifies a period during which the production amount Pm2 becomes equal to or more than the target production amount Pg. Therefore, the user of the operation assistance apparatus <NUM> can know the period T during which the ion exchange membrane <NUM> can be updated. Note that the period T may be displayed on the display unit <NUM>.

When the operation assistance apparatus <NUM> is a computer, the computer may be installed with an operation assistance program for causing the computer to function as the operation assistance apparatus <NUM>. The computer may be installed with an operation assistance program for executing a production amount acquisition function of acquiring the target production amount Pg of the product P produced in the predetermined period T by one or more electrolyzers <NUM>, a production amount calculation function of calculating the maximum production amount Pm of the product P when the ion exchange membrane <NUM> is updated, the maximum production amount being the maximum production amount Pm of the product P produced in the period T by one or more electrolyzers <NUM>, and a period specification function of specifying the period T during which the maximum production amount Pm becomes equal to or more than the target production amount Pg. When the operation assistance apparatus <NUM> is a computer, the computer may be installed with an operation assistance program for executing an operation assistance method to be described later.

Since the performance of the ion exchange membrane <NUM> is likely to deteriorate with the lapse of the time period, the electricity cost for functioning of the electrolytic apparatus <NUM> (see <FIG> and <FIG>) is likely to increase with the lapse of the time period. However, when the ion exchange membrane <NUM> is replaced before the performance of the ion exchange membrane <NUM> completely deteriorates, the unredeemed cost of the ion exchange membrane <NUM> is incurred. Before the performance of the ion exchange membrane <NUM> completely deteriorates, the unredeemed cost is likely to decrease with the lapse of the time period. Therefore, the cost C is likely to become minimum at a certain time with the lapse of the time period. In the present example, the time at which the cost C becomes minimum is defined as time ta. In <FIG>, the position of the cost C at the time ta is indicated by a black circle.

The period specification unit <NUM> (see <FIG>) may specify the timing at which the cost C is minimized in the period T during which the maximum production amount Pm (production amount Pm2) of the product P when the ion exchange membrane <NUM> is updated is becomes equal to or more than the target production amount Pg. In the present example, the time ta is included in the period T2 in which the production amount Pm2 is less than the target production amount Pg, the period specification unit <NUM> specifies the timing, at which the cost C is minimized, between the period T1 and the period T3. The time of the timing is defined as the time t2. As a result, the user of the operation assistance apparatus <NUM> can know the period T during which the ion exchange membrane <NUM> can be updated and the time t2 of the period T at which the cost C is minimized. In <FIG>, the position of the cost C at the time t2 is indicated by a white circle.

<FIG> is a diagram illustrating another example of the block diagram of the operation assistance apparatus <NUM> according to one embodiment of the present invention. The operation assistance apparatus <NUM> of the present example is different from the operation assistance apparatus <NUM> illustrated in <FIG> in that a power amount acquisition unit <NUM> and an electrolyzer specification unit <NUM> are further included.

The power amount acquisition unit <NUM> acquires a power amount for each of the plurality of electrolyzers <NUM> (see <FIG>) to produce the product P. The power amount is defined as a power amount Pw. The power amount acquisition unit <NUM> may acquire the power amount Pw for each of the plurality of electrolyzers <NUM> to produce the same amount of the product P. The power amount Pw for producing the product P may be the power amount Pw (so-called electric power consumption rate) necessary for producing a unit amount of the product P.

The electrolyzer specification unit <NUM> specifies the electrolyzer <NUM> having the maximum power amount Pw among the plurality of electrolyzers <NUM> (see <FIG>). The power amount Pw is the power amount Pw acquired by the power amount acquisition unit <NUM>. The electrolyzer specification unit <NUM> may specify one electrolyzer <NUM>, or may specify K (<NUM> < K < M, see <FIG>) electrolyzers <NUM>.

As the ion exchange membrane <NUM> deteriorates, the power amount Pw consumed by the electrolyzer <NUM> having the ion exchange membrane <NUM> is likely to increase. The electrolyzer <NUM> having the maximum power amount Pw may refer to the electrolyzer <NUM>, which consumes the most amount of power, among the electrolyzers <NUM> which consume more amount of power than before the deterioration of the ion exchange membrane <NUM> due to the deterioration of the ion exchange membrane <NUM>. The electrolyzer specification unit <NUM> specifies the electrolyzer <NUM> having the maximum power amount Pw, so that the user of the operation assistance apparatus <NUM> can know the electrolyzer <NUM> for which it is preferable to update the ion exchange membrane <NUM>.

The power amount acquisition unit <NUM> may acquire the total power amount Pw in the plurality of electrolyzers <NUM> (see <FIG>). The electrolyzer specification unit <NUM> may specify one or more electrolyzers <NUM> having the power amount Pw among the plurality of electrolyzers <NUM> when the total power amount Pw in the period T is minimum.

The electrolyzer specification unit <NUM> may specify the electrolyzer <NUM> having the lowest current efficiency among the plurality of electrolyzers <NUM> (see <FIG>). In the present example, the current efficiency refers to a ratio of the actual production amount Pa to the theoretical production amount Pa of the product P. When an aqueous NaCl (sodium chloride) solution is supplied to the anode chamber <NUM> (see <FIG>) and an aqueous NaOH (sodium hydroxide) solution is supplied to the cathode chamber <NUM> (see <FIG>), the theoretical production amount Pa is calculated on the basis of the maximum current flowing through the electrolyzer <NUM> and the current efficiency.

When the production amount Pa of the product P produced by the plurality of electrolyzers <NUM> (see <FIG>) in the period T is maximized, the power amount Pw consumed by the plurality of electrolyzers <NUM> in the period T is minimized, the mass of the alkali metal chloride contained in the aqueous solution (the liquid <NUM> in <FIG>) of the alkali metal hydroxide discharged from the cathode chamber <NUM> is minimized, or the mass of O<NUM> (oxygen) contained in the gas <NUM> (see <FIG>, Cl<NUM> (chlorine) in the present example) discharged from the anode chamber is minimized, the electrolyzer specification unit <NUM> may specify the electrolyzer <NUM> having the lowest current efficiency among the plurality of electrolyzers <NUM>. The operation assistance apparatus <NUM> may include a plurality of electrolyzer specification units <NUM>.

The production amount acquisition unit <NUM> may acquire the production amount Pa of the product P produced by each of the plurality of electrolyzers <NUM> (see <FIG>) in the period T. The production amount calculation unit <NUM> may calculate the production amount Pa of the product P produced by each of the plurality of electrolyzers <NUM> in the period T. In the present example, the period T is at least one of the period T1 to the period T4 (see <FIG>). The production amount Pa calculated by the production amount calculation unit <NUM> may refer to the production amount Pa that can be theoretically produced by the electrolytic apparatus <NUM> in the period T.

The electrolyzer specification unit <NUM> may specify the electrolyzer <NUM>, of which the ion exchange membrane <NUM> is to be updated, among the plurality of electrolyzers <NUM> on the basis of the production amount Pa of the product P acquired by the production amount acquisition unit <NUM> and the production amount Pa of the product P calculated by the production amount calculation unit <NUM>. The electrolyzer specification unit <NUM> may specify the electrolyzer <NUM> to be updated on the basis of a ratio between the acquired production amount Pa and the calculated production amount Pa. When the ion exchange membrane <NUM> deteriorates, the ratio is less than <NUM>. The electrolyzer <NUM>, of which the ion exchange membrane <NUM> is to be updated, may refer to the electrolyzer <NUM> for which it is preferable to update the ion exchange membrane <NUM> due to the deterioration in the performance of the ion exchange membrane <NUM>.

The electrolyzer specification unit <NUM> may specify the electrolyzer <NUM>, in which the production amount Pa of the product P acquired by the production amount acquisition unit <NUM> is minimum, among the plurality of electrolyzers <NUM> (see <FIG>). In the electrolyzers <NUM>-<NUM> to <NUM>-M illustrated in <FIG>, theoretically producible production amounts Pa in the respective electrolyzers <NUM> in the period T may be the same or different. The electrolyzer specification unit <NUM> may specify the electrolyzer <NUM> in which the production amount Pa is minimum regardless of whether the production amount Pa is the same or different.

<FIG> is a diagram illustrating another example of the block diagram of the operation assistance apparatus <NUM> according to one embodiment of the present invention. The operation assistance apparatus <NUM> of the present example is different from the operation assistance apparatus <NUM> illustrated in <FIG> in that a deterioration speed acquisition unit <NUM> is further included. The deterioration speed acquisition unit <NUM> acquires the deterioration speed of the ion exchange membrane <NUM> in each of the plurality of electrolyzers <NUM> (see <FIG>). The deterioration speed is defined as a deterioration speed Vd.

As described above, the performance of the ion exchange membrane <NUM> is likely to deteriorate with the functioning time of the electrolyzer <NUM> (see <FIG> and <FIG>). There is a case where the deterioration speed Vd of the ion exchange membrane <NUM> is different depending on the ion exchange membrane <NUM>. The case where the deterioration speed Vd of the ion exchange membrane <NUM> is different includes a case where the deterioration speed Vd is different due to individual differences within a range of a predetermined performance of the ion exchange membrane <NUM> and a case where the ion exchange membrane <NUM> is out of the range of the predetermined performance so that the deterioration speed Vd is higher than that of the ion exchange membrane <NUM> within the range of the predetermined performance. The predetermined performance of the ion exchange membrane <NUM> may be the performance of the ion exchange membrane <NUM> in specification. The case where the performance of the ion exchange membrane <NUM> is out of the range of the predetermined performance includes, for example, a case where the ion exchange membrane <NUM> is defective, a case where a hole is formed in the ion exchange membrane <NUM> while the electrolyzer <NUM> is in functioning, and the like.

When the deterioration speed Vd of the ion exchange membrane <NUM> is different, the deterioration speed Vd may be further different due to a difference in the type of the ion exchange membrane <NUM>. The type of the ion exchange membrane <NUM> may be the type of the anion group <NUM>. The types of the plurality of electrolyzers <NUM> (see <FIG>) may be the same or different from each other. The type of the electrolyzer <NUM> may be at least one type of the anode <NUM> or the cathode <NUM>. When the types of the plurality of electrolyzers <NUM> are different from each other, the types of the ion exchange membranes <NUM> optimum for respective electrolyzers <NUM> may be different.

The electrolyzer specification unit <NUM> may specify the electrolyzer <NUM>, of which the ion exchange membrane <NUM> is to be updated, among the plurality of electrolyzers <NUM> (see <FIG>) on the basis of the deterioration speed Vd of the ion exchange membrane <NUM> acquired by the deterioration speed acquisition unit <NUM>. On the basis of the deterioration speed Vd of the ion exchange membrane <NUM>, the electrolyzer specification unit <NUM> may specify the electrolyzer <NUM>, which has the ion exchange membrane <NUM> having the highest deterioration speed Vd, among the plurality of ion exchange membranes <NUM> within the range of the predetermined performance. The ion exchange membrane <NUM> of the electrolyzer <NUM> (see <FIG>) specified by the electrolyzer specification unit <NUM> may be updated.

When the performance of the ion exchange membrane <NUM> is within the range of the predetermined performance as described above, a predetermined deterioration speed Vd of the ion exchange membrane <NUM> is defined as a deterioration speed Vda. When the deterioration speed Vd of one ion exchange membrane <NUM> among the ion exchange membranes <NUM> in the plurality of respective electrolyzers <NUM> (see <FIG>) is equal to or higher than the deterioration speed Vda, the electrolyzer specification unit <NUM> may specify the electrolyzer <NUM> (see <FIG>) having the one ion exchange membrane <NUM>. The case where the deterioration speed Vd is equal to or higher than the deterioration speed Vda includes, for example, a case where the ion exchange membrane <NUM> is defective, a case where a hole is formed in the ion exchange membrane <NUM> while the electrolyzer <NUM> is functioning, and the like. The one ion exchange membrane <NUM> may be the ion exchange membrane <NUM> out of the range of the predetermined performance described above. The one ion exchange membrane <NUM> in the electrolyzer <NUM> specified by the electrolyzer specification unit <NUM> may be updated.

When the ion exchange membrane <NUM> is updated, the relationship between the time period t and the production amount Pm1, the relationship between the time period t and the production amount Pm2, and the relationship between the time period t and the cost C illustrated in <FIG> are updated. The production amount calculation unit <NUM> may further calculate the maximum production amount Pm of the product P when one ion exchange membrane <NUM> which is specified by the electrolyzer specification unit <NUM> and has the deterioration speed Vd equal to or higher than the deterioration speed Vda is updated. When the one ion exchange membrane <NUM> is updated, the period specification unit <NUM> may further specify the period T during which the maximum production amount Pm becomes equal to or more than the target production amount Pd, and may further specify the timing at which the cost C is minimized in the period T during which the maximum production amount Pm (production amount Pm2) of the product P becomes equal to or more than the target production amount Pg.

<FIG> is a diagram illustrating another example of the block diagram of the operation assistance apparatus <NUM> according to one embodiment of the present invention. The operation assistance apparatus <NUM> of the present example is different from the operation assistance apparatus <NUM> illustrated in <FIG> in that a pH acquisition unit <NUM>, a current calculation unit <NUM>, and a current supply unit <NUM> are further included. The pH acquisition unit <NUM> acquires a pH of the aqueous NaCl (sodium chloride) solution introduced into the anode chamber <NUM> (see <FIG>) and a pH of the aqueous NaCl (sodium chloride) solution discharged from the anode chamber <NUM>, or acquires a pH of the aqueous KCI (potassium chloride) solution introduced into the anode chamber <NUM> and a pH of the aqueous KCl (potassium chloride) solution discharged from the anode chamber <NUM>. The current calculation unit <NUM> and the current supply unit <NUM> will be described later. In the following description, a case where an aqueous NaCl (sodium chloride) solution is introduced into the anode chamber <NUM>, an aqueous NaOH (sodium hydroxide) solution is discharged from the cathode chamber <NUM>, an aqueous KCI (potassium chloride) solution is introduced into the anode chamber <NUM>, and an aqueous KOH (potassium hydroxide) solution is discharged from the cathode chamber <NUM> will not be described.

The electrolyzer specification unit <NUM> may specify the electrolyzer <NUM>, of which the ion exchange membrane <NUM> is to be updated, among the plurality of electrolyzers <NUM> (see <FIG>) on the basis of the pH of the aqueous NaCl (sodium chloride) solution acquired by the pH acquisition unit <NUM>. The aqueous NaCl (sodium chloride) solution may be the aqueous NaCl (sodium chloride) solution (the liquid <NUM> in <FIG>) introduced into the anode chamber <NUM>. The aqueous NaOH (sodium hydroxide) solution may be the aqueous NaOH (sodium hydroxide) solution (the liquid <NUM> in <FIG>) discharged from the cathode chamber <NUM>.

When the ion exchange membrane <NUM> does not deteriorate, OH- (hydroxide ions) of the cathode chamber <NUM> hardly passes through the ion exchange membrane <NUM>. However, when the ion exchange membrane <NUM> deteriorates, OH- (hydroxide ions) of the cathode chamber <NUM> may pass through the ion exchange membrane <NUM> and move to the anode chamber <NUM>. Therefore, the electrolyzer specification unit <NUM> can specify the electrolyzer <NUM> having the deteriorated ion exchange membrane <NUM> on the basis of the pH of the aqueous NaCl (sodium chloride) solution.

<FIG> is a diagram illustrating an example of a display mode on the display unit <NUM>. In the present example, a first selection unit <NUM>, a designation unit <NUM>, and a second selection unit <NUM> are displayed on the display unit <NUM>. In the present example, the user of the operation assistance apparatus <NUM> may input a first condition Cd1 for causing the electrolytic apparatus <NUM> (see <FIG>) to function in the first selection unit <NUM> and the designation unit <NUM> by the input unit <NUM> (see <FIG>). In the present example, the user of the operation assistance apparatus <NUM> inputs a second condition Cd2 for causing the electrolytic apparatus <NUM> to function in the second selection unit <NUM> by the input unit <NUM>.

In the present example, the first selection unit <NUM> includes three options <NUM> (options <NUM>-<NUM> to <NUM>-<NUM>), and the second selection unit <NUM> includes five options <NUM> (options <NUM>-<NUM> to <NUM>-<NUM>). In the present example, three designation units <NUM> (designation units <NUM>-<NUM> to <NUM>-<NUM>) are displayed on the display unit <NUM>.

The second condition Cd2 is a condition (that is, a target condition) that the user of the operation assistance apparatus <NUM> desires to achieve when the product P is produced by the electrolytic apparatus <NUM> (see <FIG>). The current calculation unit <NUM> (see <FIG>) calculates the current at which the production amount Pa of the product P produced by the plurality of electrolyzers <NUM> (see <FIG>) in the period T is maximized, the power amount Pw consumed in the period T is minimized, the mass of NaCl (sodium chloride), which is introduced into the anode chamber <NUM> and is contained in the aqueous NaOH (sodium hydroxide) solution discharged from the cathode chamber <NUM>, is minimized, or the mass of O<NUM> (oxygen) contained in Cl<NUM> (chlorine) discharged from the anode chamber <NUM> is minimized.

NaOH (sodium hydroxide) in the aqueous NaOH (sodium hydroxide) solution discharged from the cathode chamber <NUM> and Cl<NUM> (chlorine) discharged from the anode chamber <NUM> are the product P (that is, a target product) of the electrolyzer <NUM>. Therefore, the mass of NaCl (sodium chloride) contained in the NaOH (sodium hydroxide) and the mass of O<NUM> (oxygen) contained in the Cl<NUM> (chlorine) are preferably as small as possible.

When any option <NUM> of the options <NUM>-<NUM> to <NUM>-<NUM> is selected, with this as momentum, the current calculation unit <NUM> may calculate the current at which the production amount Pa is maximized, the power amount Pw is minimized, the mass of NaCl (sodium chloride) is minimized, or the mass of O<NUM> (oxygen) is minimized. The current calculation unit <NUM> (see <FIG>) may calculate the current at which the NaCl (sodium chloride) concentration of the aqueous NaOH (sodium hydroxide) solution discharged from the cathode chamber <NUM> is minimized or the O<NUM> (oxygen) concentration of the Cl<NUM> (chlorine) discharged from the anode chamber <NUM> is minimized.

The first condition Cd1 is a condition guaranteed while satisfying the second condition Cd2 in the case of producing the product P by the electrolytic apparatus <NUM> (see <FIG>). The first condition Cd1 may be a condition (that is, a constraint condition) that the user of the operation assistance apparatus <NUM> desires to guarantee while satisfying the second condition Cd2.

<FIG> is a diagram illustrating an example of the display mode of the display unit <NUM> when the second condition Cd2 is selected. In the present example, it is assumed that the first condition Cd1 is not selected, but a predetermined production amount Pa1 is designated as the production amount Pa of NaOH (sodium hydroxide). In the present example, the option <NUM>-<NUM> is selected as the second condition Cd2.

The current calculation unit <NUM> may calculate the current at which the power amount Pw is minimized when the production amount Pa of the product P is equal to or more than a predetermined production amount. In the present example, the current calculation unit <NUM> calculates the current at which the power amount Pw is minimized when the production amount Pa of NaOH (sodium hydroxide) is equal to or more than the production amount Pa1. The production amount Pa1 is, for example, <NUM> tons/day.

<FIG> is a diagram illustrating an example of an operation condition Cda and an optimal operation condition Cdb. The optimal operation condition Cdb is a condition optimized such that the current supplied to each of the plurality of electrolyzers <NUM> satisfies the second condition Cd2 while the electrolytic apparatus <NUM> satisfies the first condition Cd1. The operation condition Cda may be an operation condition before the optimal operation condition Cdb is applied. In the present example, it is assumed that the electrolytic apparatus <NUM> includes six electrolyzers <NUM> (electrolyzers <NUM>-<NUM> to <NUM>-<NUM>). In the present example, the operation condition Cda and the optimal operation condition Cdb may be displayed on the display unit <NUM>.

The cell voltage CV and the current efficiency CE of each of the plurality of electrolyzers <NUM>, and the production amount Pa and the power amount Pw in each of the plurality of electrolyzers <NUM> when each current is supplied to each of the plurality of electrolyzers <NUM> may be displayed together on the display unit <NUM>. Note that as described above, in the present example, the current efficiency CE refers to the ratio of the actual production amount Pa to the theoretical production amount Pa of the product P.

The total power amount consumed by the plurality of electrolyzers <NUM> (see <FIG>) is defined as a total power amount Pws. The current calculation unit <NUM> may calculate the current, at which the total power amount Pws is minimized, flowing to each of the electrolyzers <NUM>. As described above, the performances of the ion exchange membranes <NUM> included in the plurality of respective electrolyzers <NUM> may be different from each other. Therefore, when the magnitudes of the currents supplied to the plurality of electrolyzers <NUM> are different from each other, the total power amount Pws may be smaller than when the magnitudes of the currents are the same.

The current calculation unit <NUM> may calculate the magnitude of the current distributed to each of the plurality of electrolyzers <NUM> so as to minimize the total power amount Pws while maintaining the magnitude of the total current supplied to the plurality of electrolyzers <NUM>. The operation condition Cda illustrated in <FIG> is an example of a case where the total current (in the present example, the magnitude of <NUM> kA) is equally distributed to six electrolyzers <NUM>, and the operation condition Cdb is an example of a case where the total current (in the present example, the magnitude of <NUM> kA) is distributed so as to minimize the total power amount Pws. In the present example, the number N of the electrolysis cells <NUM> (see <FIG>) in one electrolyzer <NUM> is <NUM>.

The current supply unit <NUM> (see <FIG>) supplies the current calculated by the current calculation unit <NUM> to each of the plurality of electrolyzers <NUM>. The current supply unit <NUM> may supply, to each of the plurality of electrolyzers <NUM>, the current of the magnitude, which is calculated by the current calculation unit <NUM>, distributed to each of the plurality of electrolyzers <NUM>. As a result, the operation assistance apparatus <NUM> can assist the operation of the electrolytic apparatus <NUM> so as to minimize the power amount Pw while guaranteeing that the production amount Pa of NaOH (sodium hydroxide) is equal to or more than the production amount Pa1.

When the predetermined production amount Pa1 is designated as the production amount Pa of NaOH (sodium hydroxide) and the option <NUM>-<NUM> (that is, the production amount of NaOH (sodium hydroxide)) is selected as the second condition Cd2, the current calculation unit <NUM> may calculate the current at which the production amount Pa of the product P is equal to or more than the predetermined production amount and the production amount Pa is maximized.

<FIG> is a diagram illustrating another example of the display mode of the display unit <NUM> when the second condition Cd2 is selected. In the present example, the option <NUM>-<NUM> is selected as the second condition Cd2. The present example is different from the example illustrated in <FIG> in this respect. Also in the present example, it is assumed that the predetermined production amount Pa1 is designated as the production amount Pa of NaOH (sodium hydroxide). The option <NUM>-<NUM> may be selected as the second condition Cd2.

The current calculation unit <NUM> may calculate the current at which the mass of NaCl (sodium chloride) contained in the aqueous NaOH (sodium hydroxide) solution discharged from the cathode chamber <NUM> is minimized or the mass of O<NUM> (oxygen) contained in the Cl<NUM> (chlorine) discharged from the anode chamber <NUM> is minimized when the production amount Pa of the product P is equal to or more than the predetermined production amount Pa1. The current calculation unit <NUM> may calculate the magnitude of the current distributed to each of the plurality of electrolyzers <NUM> so as to minimize the mass of NaCl (sodium chloride) or minimize the mass of O<NUM> (oxygen) while maintaining the magnitude of the total current supplied to the plurality of electrolyzers <NUM>.

<FIG> is a diagram illustrating another example of the display mode of the display unit <NUM> when the first condition Cd1 and the second condition Cd2 are selected. In the present example, the option <NUM>-<NUM> is selected as the first condition Cd1, and a predetermined power amount Pw1 is input to the designation unit <NUM>-<NUM>. In the present example, the option <NUM>-<NUM> is selected as the second condition Cd2. The option <NUM>-<NUM> may be selected as the second condition Cd2.

The current calculation unit <NUM> may calculate the current at which the production amount Pa of the product P is maximized when the power amount Pw consumed in the period T by the plurality of electrolyzers <NUM> is less than a predetermined power amount. In the present example, the current calculation unit <NUM> calculates the current at which the production amount Pa is maximized when the power amount Pw consumed in the period T is less than the power amount Pw1. The power amount Pw1 is, for example, <NUM>,<NUM> kWh/day.

The total production amount in the period T by the plurality of electrolyzers <NUM> (see <FIG>) is defined as a total production amount Pas. The current calculation unit <NUM> may calculate the current, at which the total production amount Pas is maximized, flowing to each of the electrolyzers <NUM>. Similarly to the case of <FIG>, the current calculation unit <NUM> may calculate the magnitude of the current distributed to each of the plurality of electrolyzers <NUM> so as to maximize the total production amount Pas while maintaining the magnitude of the total current supplied to the plurality of electrolyzers <NUM>.

The current supply unit <NUM> may supply, to each of the plurality of electrolyzers <NUM>, the current of the magnitude, which is calculated by the current calculation unit <NUM>, distributed to each of the plurality of electrolyzers <NUM>. As a result, the operation assistance apparatus <NUM> can assist the operation of the electrolytic apparatus <NUM> so as to maximize the production amount Pa while guaranteeing that the power amount Pw consumed in the period T by the plurality of electrolyzers <NUM> is less than the power amount Pw1.

When the option <NUM>-<NUM> (that is, the power amount Pw) is selected as the first condition Cd1 and the option <NUM>-<NUM> (that is, the power amount Pw) is selected as the second condition Cd2, the current calculation unit <NUM> may calculate the current at which the power amount Pw consumed in the period T by the plurality of electrolyzers <NUM> is less than the predetermined power amount Pw1 and the power amount Pw is minimized.

<FIG> is a diagram illustrating another example of the display mode of the display unit <NUM> when the first condition Cd1 and the second condition Cd2 are selected. In the present example, the option <NUM>-<NUM> is selected as the second condition Cd2. the present example is different from the example illustrated in <FIG> in this respect. The option <NUM>-<NUM> may be selected as the second condition Cd2.

The current calculation unit <NUM> may calculate the current at which the mass of NaCl (sodium chloride) contained in the aqueous NaOH (sodium hydroxide) solution discharged from the cathode chamber <NUM> is minimized or the mass of O<NUM> (oxygen) contained in the Cl<NUM> (chlorine) discharged from the anode chamber <NUM> is minimized when the power amount Pw consumed in the period T by the plurality of electrolyzers <NUM> is less than the predetermined power amount Pw1. Similarly to the case of <FIG>, the current calculation unit <NUM> may calculate the magnitude of the current distributed to each of the plurality of electrolyzers <NUM> so as to minimize the mass of NaCl (sodium chloride) or minimize the mass of O<NUM> (oxygen) while maintaining the magnitude of the total power amount supplied to the plurality of electrolyzers <NUM>.

<FIG> is a diagram illustrating an example of a relationship between the time period t and the power amount Pw in the case of the operation condition Cda and the optimal operation condition Cdb. <FIG> is an example of the relationship between the time period t and the power amount Pw when the production of the product P is started at time t0. Each of time tL0 to time tL2 may be one time or a certain period (for example, one week or the like).

The threshold of the power amount Pw is defined as threshold power Pth. The threshold power Pth is, for example, a maximum value of power required from an electric power company. As described above, the performance of the ion exchange membrane <NUM> (see <FIG>) is likely to deteriorate with the functioning time of the electrolyzer <NUM> (see <FIG> and <FIG>). Therefore, the power amount Pw is likely to increase with the lapse of the time period t. In the present example, it is assumed that the power amount Pw is less than the threshold power Pth until the time tL1, but the power amount Pw becomes equal to or more than the threshold power Pth at the time tL2.

When the first condition Cd1 in at least one of the cases of <FIG> and <FIG> is selected, the current calculation unit <NUM> may calculate the magnitude of the current distributed to each of the plurality of electrolyzers <NUM> such that the power amount Pw is less than the threshold power Pth while maintaining the magnitude of the total power amount supplied to the plurality of electrolyzers <NUM>. As a result, the user of the operation assistance apparatus <NUM> can select to continue the functioning of the electrolytic apparatus <NUM> without replacing the ion exchange membrane <NUM> at the time tL2.

In the example illustrated in <FIG>, the current calculation unit <NUM> may calculate the magnitude of the current distributed to each of the plurality of electrolyzers <NUM> such that the power amount Pw is less than the threshold power Pth, and then may further calculate the current at which the production amount Pa of the product P is maximized. As a result, the operation assistance apparatus <NUM> can assist the operation of the electrolytic apparatus <NUM> so as to maximize the production amount Pa while guaranteeing that the power amount Pw consumed in the period T by the plurality of electrolyzers <NUM> is less than the threshold power Pth.

<FIG> is a diagram illustrating another example of the display mode of the display unit <NUM> when the first condition Cd1 and the second condition Cd2 are selected. In the present example, the option <NUM>-<NUM> is selected as the first condition Cd1, and predetermined mass M1 is input to the designation unit <NUM>-<NUM>. The option <NUM>-<NUM> may be selected as the first condition Cd1, and the predetermined mass M1 may be input to the designation unit <NUM>-<NUM>. In the present example, the option <NUM>-<NUM> is selected as the second condition Cd2. The option <NUM>-<NUM> may be selected as the second condition Cd2.

The current calculation unit <NUM> may calculate the current at which the production amount Pa of the product P is maximized when the mass of NaCl (sodium chloride) contained in the aqueous NaOH (sodium hydroxide) solution discharged from the cathode chamber <NUM> or the mass of O<NUM> (oxygen) contained in the Cl<NUM> (chlorine) discharged from the anode chamber <NUM> is less than predetermined mass. In the present example, the current calculation unit <NUM> calculates the current at which the production amount Pa is maximized when the mass of NaCl (sodium chloride) is less than the mass M1. The mass M1 is, for example, <NUM>/L.

The current calculation unit <NUM> may calculate the current flowing to each electrolyzer <NUM> at which the total production amount Pas of the product P is maximized when the mass of NaCl (sodium chloride) discharged from all the cathode chambers <NUM> of the plurality of electrolyzers <NUM> is less than the mass M1. Similarly to the case of <FIG>, the current calculation unit <NUM> may calculate the magnitude of the current distributed to each of the plurality of electrolyzers <NUM> so as to maximize the total production amount Pas while maintaining the magnitude of the total current supplied to the plurality of electrolyzers <NUM>.

The current supply unit <NUM> may supply, to each of the plurality of electrolyzers <NUM>, the current of the magnitude, which is calculated by the current calculation unit <NUM>, distributed to each of the plurality of electrolyzers <NUM>. As a result, the operation assistance apparatus <NUM> can assist the operation of the electrolytic apparatus <NUM> so as to maximize the production amount Pa while guaranteeing that the mass of NaCl (sodium chloride) contained in the aqueous NaOH (sodium hydroxide) solution discharged from the cathode chamber <NUM> or the mass of O<NUM> (oxygen) contained in the Cl<NUM> (chlorine) discharged from the anode chamber <NUM> is less than the predetermined mass M1.

When the option <NUM>-<NUM> (that is, the mass of NaCl (sodium chloride)) is selected as the first condition Cd1 and the option <NUM>-<NUM> (that is, the mass of NaCl (sodium chloride)) is selected as the second condition Cd2, the current calculation unit <NUM> may calculate the current at which the mass of NaCl (sodium chloride) contained in the aqueous NaOH (sodium hydroxide) solution discharged from the cathode chamber <NUM> is less than the predetermined mass M1 and the mass of the NaCl (sodium chloride) is minimized.

<FIG> is a diagram illustrating another example of the display mode of the display unit <NUM> when the first condition Cd1 and the second condition Cd2 are selected. In the present example, the option <NUM>-<NUM> is selected as the second condition Cd2. the present example is different from the example illustrated in <FIG> in this respect.

The current calculation unit <NUM> may calculate the current at which the power amount Pw (total power amount Pws) consumed in the period T by the plurality of electrolyzers <NUM> is minimized when the mass of NaCl (sodium chloride) contained in the aqueous NaOH (sodium hydroxide) solution discharged from the cathode chamber <NUM> or the mass of O<NUM> (oxygen) contained in the Cl<NUM> (chlorine) discharged from the anode chamber <NUM> is less than predetermined mass. Similarly to the case of <FIG>, the current calculation unit <NUM> may calculate the magnitude of the current distributed to each of the plurality of electrolyzers <NUM> so as to minimize the total power amount Pws while maintaining the magnitude of the total current supplied to the plurality of electrolyzers <NUM>.

<FIG> is a diagram illustrating an example of the relationship between the time period t and the quality of the product P in the case of the operation condition Cda and the optimal operation condition Cdb. In the present example, the quality of the product P is the mass of NaCl (sodium chloride) contained in the aqueous NaOH (sodium hydroxide) solution discharged from the cathode chamber <NUM> or the mass of O<NUM> (oxygen) contained in the Cl<NUM> (chlorine) discharged from the anode chamber <NUM>. <FIG> is an example of the relationship between the time period t and the quality of the product P when the production of the product P is started at the time t0.

As described above, the performance of the ion exchange membrane <NUM> (see <FIG>) is likely to deteriorate with the functioning time of the electrolyzer <NUM> (see <FIG> and <FIG>). Therefore, the quality of the product P is likely to deteriorate with the lapse of the time period t. The threshold of the quality of the product P is defined as a threshold Qth. In the present example, the threshold Qth is the maximum value of the mass of NaCl (sodium chloride) contained in the aqueous NaOH (sodium hydroxide) solution discharged from the cathode chamber <NUM> or the maximum value of the mass of O<NUM> (oxygen) contained in the Cl<NUM> (chlorine) discharged from the anode chamber <NUM>. In <FIG>, it is assumed that the quality is worse as the quality of the product P is larger than the threshold Qth, and the quality is better as the quality is smaller than the threshold Qth.

In the case of the operation condition Cda, the time at which the quality of the product P reaches the threshold Qth is defined as time tL1'. The time period from the time t0 to the time tL1' is defined as a time period TL1. In the case of the optimal operation condition Cdb, the time at which the quality of the product P reaches the threshold Qth is defined as time tL2'. The time period from the time t0 to the time tL2' is defined as a time period TL2.

When the first condition Cd1 in the case of at least one of <FIG> or <FIG> is selected, the current calculation unit <NUM> may calculate the magnitude of the current distributed to each of the plurality of electrolyzers <NUM> such that the mass of NaCl (sodium chloride) contained in the aqueous NaOH (sodium hydroxide) solution discharged from the cathode chamber <NUM> or the mass of O<NUM> (oxygen) contained in the Cl<NUM> (chlorine) discharged from the anode chamber <NUM> is less than the threshold Qth while maintaining the magnitude of the total current supplied to the plurality of electrolyzers <NUM>. As a result, the user of the operation assistance apparatus <NUM> can continue the functioning of the electrolytic apparatus <NUM> until the time tL2' without replacing the ion exchange membrane <NUM> at the time tL1'.

In the example illustrated in <FIG>, the current calculation unit <NUM> may calculate the magnitude of the current distributed to each of the plurality of electrolyzers <NUM> such that the mass of NaCl (sodium chloride) contained in the aqueous NaOH (sodium hydroxide) solution discharged from the cathode chamber <NUM> or the mass of O<NUM> (oxygen) contained in the Cl<NUM> (chlorine) discharged from the anode chamber <NUM> is less than the threshold Qth, and then may further calculate the current at which the production amount Pa of the product P is maximized. As a result, the operation assistance apparatus <NUM> can assist the operation of the electrolytic apparatus <NUM> so as to maximize the production amount Pa while guaranteeing that the mass of NaCl (sodium chloride) contained in the aqueous NaOH (sodium hydroxide) solution discharged from the cathode chamber <NUM> or the mass of O<NUM> (oxygen) contained in the Cl<NUM> (chlorine) discharged from the anode chamber <NUM> is less than the threshold Qth.

<FIG>, <FIG> <FIG>, and <FIG>are examples in which one first condition C1 is selected and one second condition C2 is selected. A plurality of first conditions C1 may be selected, and a plurality of second conditions C2 may be selected.

<FIG> is a schematic diagram illustrating an example of a method of deriving the optimal operation condition Cdb. When the first condition Cd1 (see <FIG> or the like), the second condition Cd2 (see <FIG> or the like), and a measurement value Me are input, an operation condition inference model <NUM> outputs the optimal operation condition Cdb for the first condition Cd1, the second condition Cd2, and the measurement value Me. Here, the measurement value Me may include at least one of the measurement value of the current supplied to each of the plurality of electrolyzers <NUM> (see <FIG>), the measurement value of the voltage supplied to each of the plurality of electrolyzers <NUM>, the temperature of each of the plurality of electrolyzers <NUM>, the concentration or mass of NaCl (sodium chloride) in the cathode chamber <NUM> of each of the plurality of electrolyzers <NUM>, the concentration or mass of O<NUM> (oxygen) in the anode chamber <NUM> of each of the plurality of electrolyzers <NUM>, the pH of the aqueous NaOH (sodium hydroxide) solution in the cathode chamber <NUM> of each of the plurality of electrolyzers <NUM>, or the pH of the aqueous NaCl (sodium chloride) solution in the anode chamber <NUM> of each of the plurality of electrolyzers <NUM>.

The operation condition inference model <NUM> may be generated by performing machine learning on the first condition Cd1 (see <FIG> or the like), the second condition Cd2 (see <FIG> or the like), the measurement value Me, and the optimal operation condition Cdb. The operation condition inference model <NUM> may be a regression formula.

<FIG> is a diagram illustrating an example of the relationship between the time period t and the cell voltage CV. <FIG> is a diagram illustrating an example of the relationship between the time period t and the current efficiency CE. In <FIG> and <FIG>, the current time is defined as time tp. As described above, the performance of the ion exchange membrane <NUM> (see <FIG>) is likely to deteriorate with the functioning time of the electrolyzer <NUM> (see <FIG> and <FIG>). Therefore, from the past to the current time tp, the cell voltage CV is likely to increase, and the current efficiency CE is likely to decrease.

The relationship between the time period t after the time tp and the cell voltage CV and the relationship between the time period t and the current efficiency CE may be calculated on the basis of the operation condition inference model <NUM>. In <FIG> and <FIG>, the calculated relationship between the time period t and the cell voltage CV and the calculated relationship between the time period t and the current efficiency CE are indicated by broken lines.

<FIG> is a flowchart illustrating an example of a method of deriving the optimal operation condition Cdb. Step S100 is a measurement value Me acquisition step. In step S100, the operation assistance apparatus <NUM> may acquire the measurement value Me. As described above, the measurement value Me may include at least one of the measurement value of the current supplied to each of the plurality of electrolyzers <NUM> (see <FIG>), the measurement value of the voltage supplied to each of the plurality of electrolyzers <NUM>, the temperature of each of the plurality of electrolyzers <NUM>, the concentration or mass of NaCl (sodium chloride) in the cathode chamber <NUM> of each of the plurality of electrolyzers <NUM>, the concentration or mass of O<NUM> (oxygen) in the anode chamber <NUM> of each of the plurality of electrolyzers <NUM>, the pH of the aqueous NaOH (sodium hydroxide) solution in the cathode chamber <NUM> of each of the plurality of electrolyzers <NUM>, or the pH of the aqueous NaCl (sodium chloride) solution in the anode chamber <NUM> of each of the plurality of electrolyzers <NUM>.

Step S102 is a prediction value calculation step. In step S102, the operation assistance apparatus <NUM> may calculate a prediction value Mp on the basis of the operation condition inference model <NUM>. The prediction value Mp is, for example, a value included in the broken line portions in <FIG> and <FIG>.

Step S104 is an operation condition Cda deriving step. In step S104, the operation assistance apparatus <NUM> may derive the operation condition satisfying the first condition Cd1 on the basis of the operation condition inference model <NUM>.

Step S106 is an optimal operation condition Cdb deriving step. In step S106, the operation assistance apparatus <NUM> may derive the operation condition further satisfying the second condition Cd2 on the basis of the operation condition inference model <NUM>.

Step S108 is a determination step. In step S108, the operation assistance apparatus <NUM> determines whether the optimal operation condition Cdb derived in step S106 satisfies a desired operation condition (for example, the first condition Cd1 and the second condition Cd2). When it is determined that the desired operation condition is satisfied, the operation assistance apparatus <NUM> ends deriving the optimal operation condition Cdb. When it is determined that the desired operation condition is not satisfied, the operation assistance apparatus <NUM> returns to step S104 to derive the operation condition Cda again.

<FIG> is a diagram illustrating an example of an update moment of the ion exchange membrane <NUM> (see <FIG>) in the case of the operation condition Cda and the case of the optimal operation condition Cdb. The case of the operation condition Cda may be an operation condition before the optimal operation condition Cdb is derived by the operation condition inference model <NUM>. In the case of the operation condition Cda, the optimal update moment of the ion exchange membrane <NUM> is set to be the electrolyzers <NUM>-<NUM> to <NUM>-<NUM> in the ascending order. In the case of the optimal operation condition Cdb, the magnitude of the current distributed to each of the plurality of electrolyzers <NUM> can change as compared with the case of the operation condition Cda. Therefore, in the case of the optimal operation condition Cdb, the optimal update moment of the ion exchange membrane <NUM> can change as compared with the case of the operation condition Cda. In the present example, the order of updating the electrolyzers <NUM>-<NUM> to <NUM>-<NUM> changes as compared with the case of the operation condition Cda.

<FIG> is a diagram illustrating an example of a flow when the method of deriving the optimal operation condition Cdb illustrated in <FIG> is repeatedly executed. A method of deriving the optimal operation condition Cdb may be repeatedly executed at intervals of a time period Ti. The time period Ti is, for example, one month. In the present example, in steps S200 to S204, first to third methods of deriving the optimal operation condition Cdb are executed, respectively.

In the optimal operation condition Cdb derived in step S202, the current distributed to each of the plurality of electrolyzers <NUM> (see <FIG>) may be different compared with the case of the optimal operation condition Cdb in step S200. In the present example, step S204 is set to be performed at the timing (timing at which the ion exchange membrane <NUM> can be updated and the cost C is minimized) of the time t2 illustrated in <FIG>. In step S204, the optimal operation condition Cdb may be derived after the ion exchange membrane <NUM> is updated. In step S210, it is assumed that the optimal operation condition Cdb does not satisfy the desired operation condition even if the optimal operation condition Cdb is derived. In step S210, the optimal operation condition Cdb may be derived after the cathode <NUM> and the anode <NUM> are updated.

<FIG> is a flowchart illustrating an example of the operation assistance method according to one embodiment of the present invention. The operation assistance method according to one embodiment of the present invention is an operation assistance method of assisting the operation of the electrolytic apparatus <NUM> (see <FIG>).

A production amount acquisition step S300 is a step in which the production amount acquisition unit <NUM> (see <FIG>) acquires the target production amount Pg (see <FIG>) of the product P produced in the predetermined period T by one or more electrolyzers <NUM> (see <FIG>). A production amount calculation step S302 is a step in which the production amount calculation unit <NUM> calculates the maximum production amount Pm (the production amount Pm2 in <FIG>) of the product P produced in the predetermined period T by one or more electrolyzers <NUM>. The maximum production amount Pm is the maximum production amount of the product P when the ion exchange membrane <NUM> (see <FIG>) is updated.

Note that the production amount calculation step S302 may be performed after the production amount acquisition step S300 or may be performed before the production amount acquisition step S300. The production amount calculation step S302 may be performed simultaneously with the production amount acquisition step S300.

A period specification step S318 is a step in which the period specification unit <NUM> (see <FIG>) specifies a period during which the maximum production amount Pm becomes equal to or more than the target production amount Pg. In the operation assistance method, in the period specification step S318, the period specification unit <NUM> specifies a period during which the maximum production amount Pm becomes equal to or more than the target production amount Pg. Therefore, the user of the operation assistance method can know the period T during which the ion exchange membrane <NUM> can be updated.

<FIG> is a flowchart illustrating an example of the operation assistance method according to one embodiment of the present invention. The operation assistance method of the present example is different from the operation assistance method illustrated in <FIG> in that steps S304 to S316 are further included.

A cost calculation step S304 is a step in which the cost calculation unit <NUM> (see <FIG>) calculates the cost related to the functioning of one or more electrolyzers <NUM> (see <FIG>). A deterioration speed acquisition step S306 is a step in which the deterioration speed acquisition unit <NUM> (see <FIG>) acquires the deterioration speed of the ion exchange membrane <NUM> (see <FIG>) in each of the plurality of electrolyzers <NUM>. A pH acquisition step S308 is a step in which the pH acquisition unit <NUM> (see <FIG>) acquires the pH of the aqueous solution of the alkali metal chloride introduced into the anode chamber <NUM> and the pH of the aqueous solution of the alkali metal chloride discharged from the anode chamber <NUM>.

The current calculation step S310 is a step in which the current calculation unit <NUM> (see <FIG>) calculates the current at which the total production amount Pas of the product P produced in the period T by the plurality of electrolyzers <NUM> (see <FIG>) is maximized, the total power amount Pws consumed in the period T by the plurality of electrolyzers <NUM> is minimized, the mass of the alkali metal chloride, which is introduced into the anode chamber <NUM> and is contained in the aqueous solution of the alkali metal hydroxide discharged from the cathode chamber <NUM>, is minimized, or the mass of O<NUM> (oxygen) contained in the Cl<NUM> (chlorine) discharged from the anode chamber <NUM> is minimized. A current supply step S312 is a step in which the current supply unit <NUM> (see <FIG>) supplies the current calculated in the current calculation step S310 to each of the plurality of electrolyzers <NUM> (see <FIG>).

A power amount acquisition step S314 is a step in which the power amount acquisition unit <NUM> (see <FIG>) acquires the power amount Pw for each of the plurality of electrolyzers <NUM> (see <FIG>) to produce the product P. An electrolyzer specification step S316 is a step in which the electrolyzer specification unit <NUM> (see <FIG>) specifies the electrolyzer <NUM> having the maximum power amount Pw among the plurality of electrolyzers <NUM>.

In the period specification step S318, the period specification unit <NUM> may specify timing (the time t2 in <FIG>), at which the cost C calculated in the cost calculation step S304 is minimized, in the period T. As a result, the user of the operation assistance method can know the period T during which the ion exchange membrane <NUM> (see <FIG>) can be updated and the time t2 of the period T at which the cost C is minimized.

In the electrolyzer specification step S316, the electrolyzer specification unit <NUM> (see <FIG>) specifies the electrolyzer <NUM> having the maximum power amount Pw among the plurality of electrolyzers <NUM>. As a result, the user of the operation assistance method can know the electrolyzer <NUM> (see <FIG>) for which it is preferable to update the ion exchange membrane <NUM> (see <FIG>). As described above, in the period specification step S318, the user of the operation assistance method can know the period T during which the ion exchange membrane <NUM> can be updated. As a result, the user of the operation assistance method can update the ion exchange membrane <NUM> in the period T.

<FIG> is a diagram illustrating an example of an operation assistance system <NUM> according to one embodiment of the present invention. The operation assistance system <NUM> includes the operation assistance apparatus <NUM> and one or more electrolyzers <NUM> (in the present example, the electrolyzers <NUM>-<NUM> to <NUM>-M). In <FIG>, the range of the operation assistance apparatus <NUM> is indicated by a rough broken line portion, and the range of the operation assistance system <NUM> is indicated by a fine broken line portion.

Various embodiments of the present invention may be described with reference to a flowchart and a block diagram. According to the various embodiments of the present invention, a block may represent (<NUM>) a step of a process where operations are executed or (<NUM>) a section of an apparatus having a role for executing operations.

A specific step may be executed by a dedicated circuit, a programmable circuit, or a processor. A specific section may be implemented by a dedicated circuit, a programmable circuit, or a processor. The programmable circuit and the processor may be supplied together with a computer readable instruction. The computer readable instruction may be stored on a computer readable medium.

The dedicated circuit may include at least one of a digital hardware circuit and an analog hardware circuit. The dedicated circuit may include at least one of an integrated circuit (IC) and a discrete circuit. The programmable circuit may a hardware circuit including include logical AND, logical OR, logical XOR, logical NAND, logical NOR, and other logical operations. The programmable circuit may include a reconfigurable hardware circuit including a flip-flop, a register, a memory element such as a field programmable gate array (FPGA) and a programmable logic array (PLA), and the like.

A computer readable medium may include any tangible device that can store instructions to be executed by a suitable device. Since the computer readable medium includes the tangible device, the computer readable medium having the instruction stored on the device constitutes a product including an instruction that may be executed in order to provide means to execute an operation specified by a flowchart or a block diagram.

The computer readable medium may be, for example, an electronic storage medium, a magnetic storage medium, an optical storage medium, an electromagnetic storage medium, a semiconductor storage medium, or the like. More specifically, for example, the computer readable medium may be a floppy (registered trademark) disk, a diskette, a hard disk, a random access memory (RAM), a read only memory (ROM), an erasable programmable read only memory (EPROM or flash memory), an electrically erasable programmable read only memory (EEPROM), a static random access memory (SRAM), a compact disk read only memory (CD-ROM), a digital versatile disk (DVD), a Blu-ray (registered trademark) disk, a memory stick, an integrated circuit card, or the like.

The computer readable instruction may include any of an assembler instruction, an instruction-set-architecture (ISA) instruction, a machine instruction, a machine dependent instruction, a microcode, a firmware instruction, state-setting data, a source code, and an object code. The source code and the object code may be written in any combination of one or more programming languages including an object oriented programming language and a procedural programming language in related art. The object oriented programming language may be, for example, Smalltalk (registered trademark), JAVA (registered trademark), C++, or the like. The procedural programming language may be, for example, a "C" programming language.

The computer readable instruction may be provided to a general purpose computer, a special purpose computer, or a processor or a programmable circuit of another programmable data processing apparatus locally or via a local area network (LAN) or a wide area network (WAN) such as the Internet. The processor or programmable circuit of a general purpose computer, a special purpose computer, or another programmable data processing apparatus may execute a computer-readable instruction in order to make means for performing the operation specified in the flowchart illustrated in <FIG> or the block diagram illustrated in <FIG>. The processor may be, for example, a computer processor, a processing unit, a microprocessor, a digital signal processor, a controller, a microcontroller, or the like.

<FIG> is a diagram illustrating an example of a computer <NUM> in which the operation assistance apparatus <NUM> according to an embodiment of the present invention may be embodied in whole or in part. The program installed in the computer <NUM> can cause the computer <NUM> to function as the operation associated with the operation assistance apparatus <NUM> according to an embodiment of the present invention or one or more sections of the operation assistance apparatus <NUM>, or to perform the operation or the one or more section, or cause the computer <NUM> to perform each step according to the operation assistance method of the present invention (see <FIG> and <FIG>). The program may be performed by the CPU <NUM> in order to cause the computer <NUM> to perform a particular operation associated with some or all of the blocks in the flowchart (<FIG> and <FIG>) and the block diagram (<FIG> and <FIG>) described in this specification.

The computer <NUM> according to the present embodiment includes a CPU <NUM>, a RAM <NUM>, a graphics controller <NUM>, and a display device <NUM>. The CPU <NUM>, the RAM <NUM>, the graphics controller <NUM>, and the display device <NUM> are mutually connected by a host controller <NUM>. The computer <NUM> further includes input and output units such as a communication interface <NUM>, a hard disk drive <NUM>, a DVD-ROM drive <NUM>, and an IC card drive. The communication interface <NUM>, the hard disk drive <NUM>, the DVD-ROM drive <NUM>, and the IC card drive, and the like are connected to the host controller <NUM> via an input and output controller <NUM>. The computer further includes legacy input and output units such as a ROM <NUM> and a keyboard <NUM>. The ROM <NUM>, the keyboard <NUM>, and the like are connected to the input and output controller <NUM> through an input and output chip <NUM>.

The CPU <NUM> operates according to programs stored in the ROM <NUM> and the RAM <NUM>, thereby controlling each unit. The graphics controller <NUM> obtains image data generated by the CPU <NUM> on a frame buffer or the like provided in the RAM <NUM> or in the RAM <NUM> itself to cause the image data to be displayed on the display device <NUM>.

The communication interface <NUM> communicates with other electronic devices via a network. The hard disk drive <NUM> stores programs and data used by the CPU <NUM> in the computer <NUM>. The DVD-ROM drive <NUM> reads the programs or the data from the DVD-ROM <NUM>, and provides the read programs or data to the hard disk drive <NUM> via the RAM <NUM>. The IC card drive reads programs and data from an IC card, or writes programs and data to the IC card.

The ROM <NUM> stores a boot program or the like executed by the computer <NUM> at the time of activation, or a program depending on the hardware of the computer <NUM>. The input and output chip <NUM> may connect various input and output units via a parallel port, a serial port, a keyboard port, a mouse port, or the like to the input and output controller <NUM>.

The program is provided by a computer readable medium such as the DVD-ROM <NUM> or the IC card. The program is read from a computer readable medium, installed in the hard disk drive <NUM>, the RAM <NUM>, or the ROM <NUM> which are also examples of the computer readable medium, and executed by the CPU <NUM>. The information processing described in these programs is read by the computer <NUM> and provides cooperation between the programs and various types of hardware resources. An apparatus or method may be constituted by realizing the operation or processing of information in accordance with the usage of the computer <NUM>.

For example, when a communication is performed between the computer <NUM> and an external device, the CPU <NUM> may execute a communication program loaded onto the RAM <NUM> to instruct communication processing to the communication interface <NUM>, on the basis of the processing described in the communication program. The communication interface <NUM>, under control of the CPU <NUM>, reads transmission data stored on a transmission buffering region provided in a recording medium such as the RAM <NUM>, the hard disk drive <NUM>, the DVD-ROM <NUM>, or the IC card, and transmits the read transmission data to a network or writes reception data received from a network to a reception buffering region or the like provided on the recording medium.

The CPU <NUM> may cause all or a necessary portion of a file or a database to be read into the RAM <NUM>, the file or the database having been stored in an external recording medium such as the hard disk drive <NUM>, the DVD-ROM drive <NUM> (DVD-ROM <NUM>), the IC card, or the like. The CPU <NUM> may perform various types of processing on the data on the RAM <NUM>. The CPU <NUM> may then write back the processed data to the external recording medium.

Various types of information, such as various types of programs, data, tables, and databases, may be stored in the recording medium to undergo information processing. The CPU <NUM> may perform various types of processing on the data read from the RAM <NUM>, which includes various types of operations, processing of information, condition judging, conditional branch, unconditional branch, search or replace of information, or the like, as described throughout the present disclosure and designated by an instruction sequence of programs. The CPU <NUM> may write the result back to the RAM <NUM>.

The CPU <NUM> may search for information in a file, a database, or the like in the recording medium. For example, when a plurality of entries, each having an attribute value of a first attribute associated with an attribute value of a second attribute, are stored in the recording medium, the CPU <NUM> may search for an entry matching the condition whose attribute value of the first attribute is designated, from among the plurality of entries, read the attribute value of the second attribute stored in the entry, and read a second attribute value to obtain the attribute value of the second attribute associated with the first attribute satisfying the predetermined condition.

The above-explained program or software modules may be stored in the computer readable media on the computer <NUM> or of the computer <NUM>. A recording medium such as a hard disk or a RAM provided in a server system connected to a dedicated communication network or the Internet can be used as the computer readable media. The program may be provided to the computer <NUM> by the recording medium.

Claim 1:
An operation assistance apparatus (<NUM>) comprising:
a production amount acquisition unit (<NUM>) which acquires a target production amount of a product produced in a predetermined period by one electrolyzer (<NUM>) or a plurality of electrolyzers (<NUM>-<NUM> to <NUM>-M);
a production amount calculation unit (<NUM>) which calculates a maximum production amount of the product when an ion exchange membrane (<NUM>) included in the one electrolyzer (<NUM>) or the plurality of electrolyzers (<NUM>-<NUM> to <NUM>-M) is updated, the maximum production amount being a maximum production amount of the product produced in the period by the one electrolyzer (<NUM>)or the plurality of electrolyzers (<NUM>-<NUM> to <NUM>-M);
a cost calculation unit (<NUM>) which calculates a cost related to functioning of the one electrolyzer (<NUM>) or the plurality of electrolyzers (<NUM>-<NUM> to <NUM>-M); and
a period specification unit (<NUM>) which specifies the period during which the maximum production amount becomes equal to or more than the target production amount and specifies timing, at which the cost is minimized, in the period during which the maximum production amount becomes equal to or more than the target production amount,
wherein the operation assistance allows a user to know the period during which the ion exchange membrane (<NUM>) can be updated.