Patent Description:
Patent Literature <NUM> (<CIT>) discloses a heating apparatus with improved cost effectiveness, the heating apparatus including an electrically driven heat pump and a fuel combustion boiler. This heating apparatus is controlled based on a building envelope coefficient of performance (BECOP) with attention given to an electricity rate and a fuel charge, in order to reduce the running cost.

<CIT> discloses a fluid heating system comprising: a heat pump apparatus including a refrigerant circuit through which a refrigerant circulates, the heat pump apparatus being configured to carry out an operation with electric power supplied by a power company having power generation plants; a flow path through which a fluid heated with the refrigerant flows; a combustion apparatus including a combustion unit, the combustion apparatus being configured to carry out an operation of heating the fluid, separately from the heat pump apparatus; and a control unit including an upper limit value acquisition unit configured to acquire an upper limit value of power consumption by the heat pump apparatus, and an operation control unit configured to control the operation of the heat pump apparatus to maintain the power consumption at a value below the upper limit value, and configured to cause the combustion apparatus to carry out the operation when an amount of heat applied to the fluid by the heat pump apparatus is insufficient.

Reducing a running cost is significant for a fluid heating system configured to heat a fluid, such as a heating apparatus, from a user's point of view.

For such a fluid heating system, however, control with only the running cost as an index is not necessarily suitable from another point of view.

A first aspect is directed to a fluid heating system including a heat pump apparatus, a flow path, a combustion apparatus, and a control unit. The heat pump apparatus includes a refrigerant circuit through which a refrigerant circulates. The heat pump apparatus is configured to carry out an operation with electric power. A fluid heated with the refrigerant flows through the flow path. The combustion apparatus includes a combustion unit. The combustion apparatus is configured to carry out an operation of heating the fluid, separately from the heat pump apparatus. The control unit includes an upper limit value acquisition unit and an operation control unit. The upper limit value acquisition unit is configured to acquire an upper limit value of power consumption by the heat pump apparatus. The operation control unit is configured to control the operation of the heat pump apparatus to maintain the power consumption at a value below the upper limit value in a first period of time during which the power consumption is restricted to a value below the upper limit value. The operation control unit is also configured to cause the combustion apparatus to carry out the operation on condition that an amount of heat applied to the fluid by the heat pump apparatus is insufficient in the first period of time.

According to this configuration, the operation control unit controls the operation of the heat pump apparatus to maintain the power consumption at a value below the upper limit value in the first period of time during which the power consumption is restricted to a value below the upper limit value. This configuration thus enables reduction in power consumption by the heat pump apparatus during peak hours of electric power supply in a region where the fluid heating system is installed, and also enables achievement of a balance between a supply of electricity and a demand for electricity in the region, for example.

According to this configuration, the operation control unit also causes the combustion apparatus to carry out the operation for a supplemental purpose when an amount of heat applied to the fluid by the heat pump apparatus is insufficient in the first period of time. This configuration thus allows a user of the fluid heating system to enjoy air heating, hot water supply, and the like without considerable deterioration in comfort.

A second aspect is directed to the fluid heating system according to the first aspect, in which the upper limit value acquisition unit receives, from an external apparatus, information about the upper limit value determined in accordance with a situation of an external power generation plant.

According to this configuration, the upper limit value acquisition unit acquires information about the upper limit value from, for example, a power supply company that supplies electricity to the heat pump apparatus or an aggregator that provides an energy management service for keeping a balance between a supply of electricity and a demand for electricity. This configuration allows a user or a manager of the fluid heating system to directly or indirectly give cooperation to an electricity supplier.

A third aspect is directed to the fluid heating system according to the first aspect, further including a first calculation unit and a second calculation unit. The first calculation unit is configured to calculate a total emission of carbon dioxide, based on information on an emission of carbon dioxide in producing electric power per unit supply power. The total emission of carbon dioxide corresponds to a sum of an emission of carbon dioxide from the heat pump apparatus during the operation and an emission of carbon dioxide from the combustion apparatus during the operation. The second calculation unit is configured to calculate the upper limit value of the power consumption, so as to reduce the total emission of carbon dioxide. The upper limit value acquisition unit acquires the upper limit value of the power consumption, from the second calculation unit.

It is typically recognized that carbon dioxide is emitted in large amounts from a combustion apparatus. In addition, carbon dioxide is emitted in generating (producing) electric power to be consumed by a heat pump apparatus. Furthermore, carbon dioxide is emitted upon thermal power generation since oil is burned, and carbon dioxide is also emitted in manufacturing a power generation apparatus that uses natural energy. In view of these respects, according to this configuration, the upper limit value acquisition unit calculates the upper limit value of the power consumption, so as to reduce the total emission of carbon dioxide. This configuration allows the fluid heating system to effectively contribute to reduction in emission of carbon dioxide on a global scale.

A fourth aspect is directed to the fluid heating system according to any one of the first to third aspects, in which on condition that the amount of heat applied to the fluid by the heat pump apparatus is insufficient in the first period of time, the operation control unit causes the combustion apparatus to carry out the operation to heat the fluid by an insufficient amount of heat owing to the restriction on the power consumption by the heat pump apparatus to a value below the upper limit value.

Typically, the emission of carbon dioxide from the heat pump apparatus during operation is smaller than the emission of carbon dioxide from the combustion apparatus during operation. In view of this respect, according to this configuration, the operation control unit causes the heat pump apparatus to carry out the operation preferentially and causes the combustion apparatus to carry out the operation in the first period of time during which the power consumption is restricted to a value below the upper limit value, by the insufficient amount of heat owing to the restriction on the power consumption by the heat pump apparatus to a value below the upper limit value. This configuration allows the fluid heating system to effectively contribute to reduction in emission of carbon dioxide on a global scale.

A fifth aspect is directed to the fluid heating system according to the second aspect, further including a first calculation unit. The first calculation unit is configured to calculate a total emission of carbon dioxide corresponding to a sum of an emission of carbon dioxide from the heat pump apparatus during the operation and an emission of carbon dioxide from the combustion apparatus during the operation. The operation control unit determines a ratio between heat applied to the fluid by the heat pump apparatus and heat applied to the fluid by the combustion apparatus and controls the operation of the heat pump apparatus and the operation of the combustion apparatus, so as to reduce the total emission of carbon dioxide, in a second period of time during which the power consumption is not necessarily restricted to a value below the upper limit value.

According to this configuration, in the second period of time during which the power consumption is not necessarily restricted to a value below the upper limit value, the operation control unit performs the control different from the control in the first period of time. The fluid heating system controls the operation of the heat pump apparatus and the operation of the combustion apparatus so as to reduce the total emission of carbon dioxide in the second period of time, thereby effectively contributing to reduction in emission of carbon dioxide on a global scale.

A sixth aspect is directed to the fluid heating system according to the second or fifth aspect, further including a third calculation unit. The third calculation unit is configured to calculate a first running cost of the heat pump apparatus during the operation and a second running cost of the combustion apparatus during the operation. The operation control unit determines a ratio between heat applied to the fluid by the heat pump apparatus and heat applied to the fluid by the combustion apparatus and controls the operation of the heat pump apparatus and the operation of the combustion apparatus, so as to reduce a sum of the first running cost and the second running cost, in a third period of time during which the power consumption is not necessarily restricted to a value below the upper limit value.

According to this configuration, in the third period of time during which the power consumption is not necessarily restricted to a value below the upper limit value, the operation control unit performs the control different from the control in the first period of time. The fluid heating system controls the operation of the heat pump apparatus and the operation of the combustion apparatus so as to reduce the sum of the first running cost and the second running cost in the third period of time, thereby allowing the user to enjoy a merit of cost reduction. On the other hand, the fluid heating system could keep the balance between the supply of electricity and the demand for electricity in the region in the first period of time as described above, thereby allowing the user to enjoy air heating, hot water supply, and the like without considerable deterioration in comfort.

A seventh aspect is directed to the fluid heating system according to any one of the first to sixth aspects, in which the fluid to be heated with the refrigerant is water. The water heated in the flow path is used for one of or both air heating and hot water supply.

An eighth aspect is directed to the fluid heating system according to any one of the first to sixth aspects, in which the fluid to be heated with the refrigerant is air. The air heated in the flow path is used for air heating.

A heating system <NUM> illustrated in <FIG> and <FIG> is an example of a fluid heating system for carrying out a heating operation by supplying, to a heat dissipator, water (an example of a fluid) heated by one of or both a heat pump unit to be driven with electric power and a boiler unit configured to burn fuel. The heating system <NUM> is one of appliances <NUM> owned by a user who is an electricity consumer, in a power consumption management system illustrated in <FIG>. The following describes the power consumption management system first, and then describes the heating system <NUM> in detail.

<FIG> is a schematic diagram illustrating the power consumption management system. The power consumption management system refers to a mechanism that gives an incentive to a user of an appliance <NUM> when the user makes an adjustment to an amount of electric power to be consumed by the appliance <NUM> for a predetermined period (hereinafter, referred to as an adjustment period) in accordance with a control request from a power company 1a. The power consumption management system gives an incentive for each user of a plurality of appliances <NUM>. Each user has contract with the power company 1a as to the use of electric power in advance, and the details of an incentive are determined based on the contract in advance. The power consumption management system is constituted of the power company 1a which is an electricity supplier as well as apparatuses, appliances, and devices installed in buildings A and B which are electricity consumers.

The power company 1a has a power management apparatus <NUM>. The power management apparatus <NUM> issues a "control request" for encouraging a power adjustment to each of the appliances <NUM>. The power management apparatus <NUM> also performs, for example, calculation of an amount of an incentive to be given to each user, based on, for example, a record showing that the appliances <NUM> respond to the control request.

Examples of facilities 3a and 3b in the buildings A and B may include, but not limited to, an office, a tenant, a factory, and an ordinary household. The buildings A and B are each equipped with, in addition to the appliances <NUM>, a power source <NUM> configured to supply electric power to the appliances <NUM>, a power meter <NUM> configured to measure amounts of electric power supplied from the power source <NUM> to the appliances <NUM>, and a control device <NUM> configured to control the appliances <NUM>. The facilities 3a and 3b in the buildings A and B receive electric power from the power company 1a through a power supply line 102a. In each building, the appliances <NUM> receive electric power from the power source <NUM> through a power supply line 102b located indoors. The power management apparatus <NUM> is connected to the control devices <NUM> via, for example, the Internet 101a. In each building, the control device <NUM> is connected to the appliances <NUM> via, for example, a dedicated control line 101b.

It should be noted that <FIG> illustrates the limited number of buildings A and B as well as the limited numbers of apparatuses, appliances, and devices in each building; however, the present disclosure is not limited to these numbers.

According to an aspect, the foregoing power consumption management system is a "demand response", and power adjustment control for achieving the demand response is referred to as "demand response control". Control to be performed on each heating system <NUM> in a first period of time (to be described later) is an example of the "demand response control".

<FIG> is a schematic diagram illustrating a configuration of the power management apparatus <NUM>. The power management apparatus <NUM> includes a communication unit <NUM>, an input unit <NUM>, an output unit <NUM>, a storage unit <NUM>, and a computation unit <NUM>.

The communication unit <NUM> is configured to communicate with the control devices <NUM>. For example, the communication unit <NUM> includes a network interface that enables a connection to the Internet 101a.

The input unit <NUM> is configured to input information to the power management apparatus <NUM>. For example, the input unit <NUM> includes an operation button, a keyboard, and a mouse.

The output unit <NUM> is configured to output, for example, information stored in the power management apparatus <NUM>. For example, the output unit <NUM> includes a display.

The storage unit <NUM> is configured to store, for example, information input to the power management apparatus <NUM>. For example, the storage unit <NUM> includes a hard disk. As illustrated in <FIG>, the storage unit <NUM> stores, for example, combinations of an adjustable amount of electric power with an adjustable period of time in each of the buildings A and B. The storage unit <NUM> is also configured to store, for example, a program to be executed by the computation unit <NUM>.

The computation unit <NUM> is configured to perform various computations based on, for example, information stored in the power management apparatus <NUM>. The computation unit <NUM> is practicable using a computer. The computation unit <NUM> includes a control computation device and a storage device. The control computation device may be a processor such as a central processing unit (CPU) or a graphics processing unit (GPU). The control computation device reads a program from the storage unit <NUM>, and performs predetermined image processing and computation processing in accordance with this program. In addition, the control computation device is capable of writing a result of the computation processing in the storage device, and reading information from the storage device, in accordance with the program. The computation unit <NUM> has various functions illustrated in the form of functional blocks in <FIG> and practicable by the control computation device. Specifically, when the control computation device reads and executes a program, the computation unit <NUM> functions as a power consumption prediction unit 15a, a power adjustment determination unit 15b, an appliance selection unit 15c, a control request issuance unit 15d, and an incentive information determination unit 15e each illustrated in <FIG>.

The power consumption prediction unit 15a is configured to predict a supply of electricity and a demand for electricity and to predict power consumption after a lapse of a predetermined time. The power consumption prediction unit 15a is also configured to determine whether the demand for electricity after the lapse of the predetermined time possibly exceeds a predetermined supply of electricity. The supply of electricity is determined depending on a situation of a power generation plant operated by the power company 1a. The power generation plant refers to a plant that generates electric power by, for example, thermal power, wind power, or solar power.

The power adjustment determination unit 15b is configured to determine, when the power consumption prediction unit 15a determines that the demand for electricity after the lapse of the predetermined time possibly exceeds the predetermined supply of electricity, an adjustment amount, an adjustment time of day, and an adjustment period for reduction in power consumption.

The appliance selection unit 15c is configured to select one of the appliances <NUM> to be subjected to demand response control, based on information on the appliances <NUM> stored in the storage unit <NUM> and the information for reduction in power consumption determined by the power adjustment determination unit 15b.

The control request issuance unit 15d is configured to issue a "control request" for encouraging an adjustment to electric power usage, to the corresponding control device <NUM> selected by the appliance selection unit 15c. The control request includes information such as an amount of electric power to be adjusted and a period of time to be adjusted. An amount of electric power to be adjusted is previously agreed depending on contract between an electricity supplier and an electricity consumer in some cases. In such a case, the control request does not include information about the amount of electric power to be adjusted.

The incentive information determination unit 15e is configured to determine information about an amount of an incentive to be given to the corresponding user. The amount of the incentive is determined from, for example, the product of an amount of electric power adjusted and a unit price of the incentive. The incentive information determination unit 15e changes, for example, the unit price of the incentive in accordance with a situation.

The appliances <NUM> are each configured to operate under a control condition set by the corresponding control device <NUM>. The power consumption management system adjusts an amount of electric power to be consumed, by causing the appliances <NUM> to operate under a control condition satisfying a control request from the power management apparatus <NUM>.

The appliances <NUM> include, in addition to the heating system <NUM>, a ventilation fan <NUM>, a lighting appliance <NUM>, and the like. The ventilation fan <NUM> is switched between an ON state and an OFF state. The ventilation fan <NUM> consumes a certain amount of electric power during operation. An example of the lighting appliance <NUM> is a lighting appliance that is switched between an ON state and an OFF state, and the lighting appliance of this type consumes a certain amount of electric power during operation. Another example of the lighting appliance <NUM> is a lighting appliance whose illuminance is switched in a multilevel manner, and the lighting appliance of this type consumes an amount of electric power that varies for each illuminance. Each heating system <NUM>, which is an example of a fluid heating system, includes the boiler unit <NUM> that consumes a slight amount of electric power and the heat pump unit <NUM> that consumes a large amount of electric power, as described above. The heating system <NUM> will be described in detail later.

<FIG> is a schematic diagram illustrating a configuration of each control device <NUM>. Each control device <NUM> is used in the power consumption management system and is configured to control the corresponding appliances <NUM>. Each control device <NUM> includes a communication unit <NUM>, an input unit <NUM>, an output unit <NUM>, a storage unit <NUM>, a setting unit <NUM>, a computation unit <NUM>, and a control unit <NUM>.

The communication unit <NUM> is configured to communicate with the power management apparatus <NUM>. For example, the communication unit <NUM> includes a network interface that enables a connection to the Internet 101a.

The input unit <NUM> is configured to input information to the control device <NUM>. For example, the input unit <NUM> includes a touch screen that covers an operation button and a display of the output unit <NUM>. The input unit <NUM> allows the corresponding user to input various commands, such as a change to settings and a change to operating modes, for each appliance <NUM>.

The output unit <NUM> is configured to output, for example, information stored in the control device <NUM>. For example, the output unit <NUM> includes the display. For example, the output unit <NUM> outputs, to the display, a screen showing an operating state of each appliance <NUM> to present, to the user, an ON or OFF state, an operating mode, a set temperature, an illuminance, an amount of ventilation, an operating time, an operating rate, and other kinds of information about an operating capacity of the appliance <NUM> during operation, and a current amount of electric power consumed by the appliance <NUM>.

The storage unit <NUM> is configured to store, for example, information input to the control device <NUM>. For example, the storage unit <NUM> includes a hard disk. The storage unit <NUM> is also configured to store a program readable and executable by the computation unit <NUM> to be described later. The storage unit <NUM> is also configured to store information on a control condition and power consumption, according to the type of appliance <NUM>.

The setting unit <NUM> is configured to set a control condition for each appliance <NUM>, based on, for example, information input through the input unit <NUM>.

The computation unit <NUM> is configured to perform various computations based on, for example, information stored in the control device <NUM>. For example, the computation unit <NUM> includes a CPU, a read only memory (ROM), and a random access memory (RAM). The computation unit <NUM> has a function practicable by reading and executing the foregoing program stored in the storage unit <NUM>. The computation unit <NUM> has a function of calculating an amount of a gained incentive, based on a control condition set by the setting unit <NUM>.

The control unit <NUM> is configured to control each appliance <NUM>, based on, for example, a control condition set by the setting unit <NUM>.

As illustrated in <FIG> and <FIG>, each heating system <NUM>, which is an example of a fluid heating system, includes, in addition to the boiler unit <NUM> and the heat pump unit <NUM>, a heat dissipation unit <NUM> and a heating control unit <NUM>.

The heat dissipation unit <NUM> includes, in a case where the heating system <NUM> is used for, for example, air heating in a house, a plurality of heat dissipators respectively placed in a plurality of rooms which are heating target spaces. Each of the heat dissipators is a heat exchanger such as a radiator, an underfloor heater, or a convection heater. In <FIG>, the plurality of heat dissipators are collectively illustrated with a block indicated by reference sign <NUM>. In addition, one or more thermostats <NUM> each including a room temperature sensor <NUM> are placed in each heating target space. Each room temperature sensor <NUM> is configured to measure a temperature in a room where the room temperature sensor <NUM> is placed. In a case where the heat dissipation unit <NUM> heats the plurality of rooms corresponding to the heating target spaces, the thermostats <NUM> are respectively placed in the rooms or are placed in many of the rooms. Each thermostat <NUM> includes the room temperature sensor <NUM>. The user of the heating system <NUM> sets a required room temperature, using each thermostat <NUM>. The user may set a different required room temperature for each room. The required room temperatures in the heating target spaces may be set in a centralized manner. Each room temperature sensor <NUM> is configured to measure a current room temperature in the corresponding room.

The heat pump unit <NUM> is an example of a heat pump apparatus configured to carry out an operation with electric power. In the present application, "HP" in the drawings represents the heat pump unit <NUM>. The heat pump unit <NUM> includes a known heat pump circuit <NUM>. The heat pump circuit <NUM> is an annular refrigerant circuit including a compressor, a condenser, an expansion mechanism, and an evaporator that are connected with a refrigerant pipe. In a heating mode, a first heat exchanger <NUM> functions as the condenser. The evaporator (not illustrated) is disposed in an outdoor unit <NUM>. Each of the compressor (not illustrated) and the expansion mechanism (not illustrated) is also disposed in the outdoor unit <NUM>. The heat pump circuit <NUM> used herein is an air heat pump. The evaporator in the outdoor unit <NUM> takes away heat from outdoor air, so that the refrigerant flowing through the heat pump circuit <NUM> evaporates and then flows toward the heat exchanger <NUM> for condensation. In a condensation process, the heat of the refrigerant is transferred to a working fluid (to be described later). Desirably, the compressor in the heat pump circuit <NUM> operates in variable frequency so as to be operable at partial load. An outdoor temperature sensor may be disposed in the outdoor unit <NUM> or may be placed at a different position where the outdoor temperature sensor is capable of measuring an outdoor temperature with reliability.

The boiler unit <NUM> is an example of a combustion apparatus. The boiler unit <NUM> is a known condensing boiler of a gas combustion type. The boiler unit <NUM> includes a burner <NUM> for heating the working fluid (to be described later). The burner <NUM> is an example of a combustion unit. The burner <NUM> is configured to heat the working fluid, separately from the heat pump unit <NUM>. The burner <NUM> is also configured to produce domestic hot water <NUM>. The domestic hot water <NUM> is directly heated, in use, by the burner <NUM> when flowing through a pipe <NUM>. The boiler unit <NUM> includes an inflow pipe <NUM> connected to an inlet of a second heat exchanger 211a to be heated by the burner <NUM>. The boiler unit <NUM> also includes an outflow pipe <NUM> connected to an outlet of the second heat exchanger 211a.

The heat pump unit <NUM> includes a first inflow pipe <NUM> and a first outflow pipe <NUM>. The first inflow pipe <NUM> is connected, via a three-way valve <NUM>, to an inlet of the first heat exchanger <NUM> and a bypass pipe <NUM> for bypassing the first heat exchanger <NUM>. The first outflow pipe <NUM> is connected to an outlet of the first heat exchanger <NUM> and the bypass pipe <NUM>. The heat pump unit <NUM> also includes a second inflow pipe <NUM>. The second inflow pipe <NUM> is connected to a second outflow pipe <NUM> via a pump <NUM> and a flow rate sensor <NUM>.

A three-way valve <NUM> and a bypass pipe <NUM> are disposed between the boiler unit <NUM> and the heat pump unit <NUM>. The bypass pipe <NUM> is a pipe for bypassing the boiler unit <NUM>. The working fluid (to be described later) bypassing the boiler unit <NUM> can be heated only by the heat pump unit <NUM>.

The second outflow pipe <NUM> of the heat pump unit <NUM> is connected to an inflow pipe <NUM> of the heat dissipation unit <NUM>. The heat dissipation unit <NUM> includes an outflow pipe <NUM> connected to the first inflow pipe <NUM> of the heat pump unit <NUM>.

A first temperature sensor <NUM> is disposed on the inflow pipe <NUM> of the heat dissipation unit <NUM> or is disposed on the second outflow pipe <NUM> of the heat pump unit <NUM> upstream of the inflow pipe <NUM>. A second temperature sensor <NUM> is disposed on the outflow pipe <NUM> of the heat dissipation unit <NUM> or is disposed on the first inflow pipe <NUM> of the heat pump unit <NUM> downstream of the outflow pipe <NUM>. A third temperature sensor <NUM> is disposed on the first outflow pipe <NUM> of the heat pump unit <NUM>.

The pipes <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, and <NUM> form a flow circuit 203a and cause the working fluid, such as water, to flow toward the heat dissipation unit <NUM>. The working fluid used herein is water. The first temperature sensor <NUM> is configured to measure a temperature of the working fluid flowing into the heat dissipation unit <NUM> through the pipe <NUM>. The second temperature sensor <NUM> is configured to measure a temperature of the working fluid flowing out of the heat dissipation unit <NUM>. The third temperature sensor <NUM> is configured to measure a temperature of the working fluid at a position downstream of the first heat exchanger <NUM> of the heat pump unit <NUM>. The pump <NUM> is configured to allow the working fluid to circulate through the flow circuit 203a. The flow rate sensor <NUM> is configured to measure a flow rate of the working fluid.

The heating control unit <NUM> is configured to control, for example, the compressor and expansion mechanism of the heat pump unit <NUM>, the pump <NUM>, the three-way valve <NUM>, the burner <NUM> of the boiler unit <NUM>, and the three-way valve <NUM>, in accordance with an instruction and a request from each thermostat <NUM>. The heating control unit <NUM> is practicable using a computer. The heating control unit <NUM> includes a control computation device and a storage unit <NUM>. The control computation device may be a processor such as a CPU or a GPU. The control computation device reads a program storaged in the storage unit <NUM>, and performs predetermined image processing and computation processing in accordance with this program. In addition, the control computation device is capable of writing a result of the computation processing in the storage device, and reading information from the storage unit <NUM>, in accordance with the program. The heating control unit <NUM> includes various functional units <NUM>, <NUM>, <NUM>, and <NUM> (see <FIG>) practicable by the control computation device. The storage unit <NUM> may serve as a database.

As illustrated in <FIG>, the heating control unit <NUM> includes, in addition to the storage unit <NUM>, an upper limit value acquisition unit <NUM>, an operation control unit <NUM>, a first calculation unit <NUM>, and a third calculation unit <NUM>.

The upper limit value acquisition unit <NUM> is configured to acquire an upper limit value of power consumption for each period of time. This upper limit value is determined by the power management apparatus <NUM> and is imposed on the heating system <NUM>. Specifically, the control request issuance unit 15d of the power management apparatus <NUM> issues a "control request" to the control device <NUM> such that an amount of electric power to be consumed by the heating system <NUM> in each building falls below a predetermined upper limit value during a period of time from <NUM>:<NUM> to <NUM>:<NUM>, for example. The control device <NUM> then sends the upper limit value of power consumption by the heating system <NUM>, to the upper limit value acquisition unit <NUM>. The upper limit value acquisition unit <NUM> thus receives the upper limit value.

As described above, the power management apparatus <NUM> determines, for each period of time, an upper limit value of power consumption by each of the appliances <NUM> including the heating system <NUM>, based on a supply of electricity which is determined in accordance with a situation of the power generation plant during operation, and a demand for electricity which is predicted. Specifically, the power adjustment determination unit 15b determines an adjustment amount, an adjustment time of day, and an adjustment period for reduction in power consumption. The control request issuance unit 15d then issues a "control request" for encouraging an adjustment to electric power usage, to each control device <NUM>.

The first calculation unit <NUM> is configured to calculate a total emission of carbon dioxide, based on information on an emission of carbon dioxide in producing electric power per unit supply power. In the present application, "CO2" represents carbon dioxide, and "CO2 EMISSION" represents an emission of carbon dioxide in the drawings. The total emission of carbon dioxide corresponds to a sum of an emission of carbon dioxide concerning power consumption by the heat pump unit <NUM> during operation and an emission of carbon dioxide resulting from fuel combustion by the boiler unit <NUM> during operation. The heating control unit <NUM> receives the information on the emission of carbon dioxide in producing electric power per unit supply power, periodically from the power management apparatus <NUM> via the control device <NUM>.

It should be noted that the emission of carbon dioxide in producing electric power per unit supply power varies depending on, for example, the number of operating power generation plants of the power company 1a and the operating rate of each operating power generation plant. For example, in a case where the power company 1a mainly relies on photovoltaic power generation and wind power generation rather than thermal power generation, an emission of carbon dioxide per unit supply power decreases. On the other hand, in a case where the power company 1a mainly relies on thermal power generation, the emission of carbon dioxide per unit supply power increases. The emission of carbon dioxide resulting from the power consumption by the heat pump unit <NUM> during operation decreases in a case where the heat pump unit <NUM> is capable of carrying out the operation under an environmental condition with good coefficient of performance (COP). However, this emission of carbon dioxide increases when the COP of the heat pump unit <NUM> lowers due to, for example, a low outside temperature.

The third calculation unit <NUM> is configured to calculate a first running cost of the heat pump unit <NUM> during operation and a second running cost of the boiler unit <NUM> during operation. Specifically, the first running cost refers to an electricity rate for the operation of the heat pump unit <NUM>. The second running cost refers to a fuel (e.g., gas) charge for the operation of the boiler unit <NUM>. The third calculation unit <NUM> calculates the first running cost and the second running cost as disclosed in, for example, <CIT>).

The operation control unit <NUM> is configured to control the operation of the heat pump unit <NUM> to maintain the power consumption by the heat pump unit <NUM> at a value below the upper limit value in a first period of time during which the power consumption in the heating system <NUM> is restricted to a value below the upper limit value. For example, the operation control unit <NUM> lowers the capacity of the compressor of the heat pump unit <NUM>, thereby reducing the power consumption by the heat pump unit <NUM>.

It should be noted that the first period of time is determined from the adjustment time of day and adjustment period of the foregoing "control request". The upper limit value of the power consumption is determined based on the adjustment amount of the "control request" for reducing the power consumption.

When the amount of heat applied to the working fluid only by the heat pump unit <NUM> is insufficient in the first period of time, the operation control unit <NUM> causes the boiler unit <NUM> to carry out the operation, so that the burner <NUM> operates to apply heat to the working fluid by an insufficient amount of heat owing to the restriction on the power consumption by the heat pump unit <NUM> to a value below the upper limit value.

The operation control unit <NUM> is also configured to determine a ratio between the heat applied to the working fluid by the heat pump unit <NUM> and the heat applied to the working fluid by the boiler unit <NUM> and control the operation of the heat pump unit <NUM> and the operation of the boiler unit <NUM>, so as to reduce the total emission of carbon dioxide in a second period of time during which the power consumption is not necessarily restricted to a value below the upper limit value.

The operation control unit <NUM> is also configured to determine a ratio between the heat applied to the working fluid by the heat pump unit <NUM> and the heat applied to the working fluid by the boiler unit <NUM> and control the operation of the heat pump unit <NUM> and the operation of the boiler unit <NUM>, so as to reduce a sum of the first running cost and the second running cost in a third period of time during which the power consumption is not necessarily restricted to a value below the upper limit value. The operation control unit <NUM> carries out an operation of reducing a running cost (an operation cost) as disclosed in, for example, <CIT>).

It should be noted that the periods of time other than the first period of time are set at the second period of time by default. The user is able to set and change a part of the second period of time or the entire second period of time as the third period of time, using the thermostat <NUM> or another setting device. In a case where the reduction in running cost is prioritized over the reduction in emission of carbon dioxide, the user is able to change a part of the second period of time or the entire second period of time to the third period of time.

<FIG> illustrates a comparison between the control performed by the operation control unit <NUM> in the second period of time and the control performed by the operation control unit <NUM> in the third period of time, in the form of an HP operating ratio relative to an outside temperature. The HP operating ratio refers to a ratio of the amount of heat applied by the heat pump unit <NUM> in a sum of the amount of heat applied by the heat pump unit <NUM> and the amount of heat applied by the boiler unit <NUM>. As illustrated in <FIG>, when the outside temperature is low, the COP of the heat pump unit <NUM> is small. As a result, the HP operating ratio is <NUM>%, so that the boiler unit <NUM> heats the working fluid singly. When the outside temperature is high, the COP of the heat pump unit <NUM> is high. As a result, the HP operating ratio is <NUM>%, so that the heat pump unit <NUM> heats the working fluid singly.

In the second period of time, the operation control unit <NUM> performs the control to prioritize the reduction in emission of carbon dioxide. In the third period of time, the operation control unit <NUM> performs the control to prioritize the reduction in running cost. As illustrated in <FIG>, the HP operating ratio tends to be high by the control that prioritizes the reduction in emission of carbon dioxide while the HP operating ratio tends to be low by the control that prioritizes the reduction in running cost, even at the same outside temperature. The graph of <FIG> is not fixed, and varies in accordance with changes in, for example, prices of electricity and fuel, a COP of the heat pump unit <NUM>, and an emission of carbon dioxide in producing electric power per unit supply power.

<FIG> is such a graph that an exemplary relationship between the outside temperature and the power consumption is added to the lower side of <FIG>. As the HP operating ratio increases, the power consumption at or below a certain outside temperature also increases. When the outside temperature exceeds the certain temperature, the amount of heat for air heating decreases, so that the power consumption lowers gradually.

The graph of <FIG> also shows an upper limit of the power consumption acquired by the upper limit value acquisition unit <NUM> (i.e., the upper limit value of the power consumption set for the heating system <NUM>). The operation control unit <NUM> controls the operation of the heat pump unit <NUM> to maintain the power consumption by the heat pump unit <NUM> at a value below the upper limit of power consumption in <FIG>, in the first period of time corresponding to the adjustment period of the "control request" from the control request issuance unit 15d to the control device <NUM>. Then, when the amount of heat applied to the working fluid only by the heat pump unit <NUM> is insufficient in the first period of time, the operation control unit <NUM> causes the boiler unit <NUM> to carry out the operation, so that the burner <NUM> applies heat to the working fluid by an insufficient amount of heat owing to the restriction on the power consumption by the heat pump unit <NUM> to a value below the upper limit value.

As described above, in the second period of time, the HP operating ratio is determined such that the emission of carbon dioxide from the heating system <NUM> is reduced, and in the third period of time, the HP operating ratio is determined such that the running cost of the heating system <NUM> is reduced. In the first period of time, on the basis of the control, the operation of the heat pump unit <NUM> is controlled such that the power consumption by the heat pump unit <NUM> does not exceed the upper limit of power consumption. When the amount of heat for air heating cannot be secured in the first period of time due to the reduction in performance of the heat pump unit <NUM>, the operation control unit <NUM> starts the boiler unit <NUM> or enhances the operation of the boiler unit <NUM> to compensate for the insufficient amount of heat.

<FIG> is a graph showing a comparison between an HP operating ratio under control for "CO2 emission first" in the second period of time during which a priority is given to the reduction in emission of carbon dioxide and an HP operating ratio under control for "power consumption limit" in the first period of time in response to the "control request". The HP operating ratio at "power consumption limit", which is indicated by a dashed line, becomes smaller than the HP operating ratio under the control for "CO2 emission first". The amount of heat applied by the heat pump unit <NUM> is reduced due to the power consumption limit, and the operation control unit <NUM> causes the boiler unit <NUM> to compensate for the insufficient amount of heat; therefore, the HP operating ratio at "power consumption limit" decreases.

<FIG>, similar to <FIG>, illustrates a comparison between an HP operating ratio under the control for "CO2 emission first" in the second period of time and an HP operating ratio under the control for "power consumption limit" in the first period of time. <FIG> also illustrates a comparison between an HP operating ratio under control for "running cost first" in the third period of time and an HP operating ratio under control for "power consumption limit" in the first period of time. According to each comparison, the amount of heat applied by the heat pump unit <NUM> is reduced at "power consumption limit", and the operation control unit <NUM> causes the boiler unit <NUM> to compensate for the insufficient amount of heat; therefore, the HP operating ratio decreases.

<FIG> is a graph showing a relationship between various kinds of control by the operation control unit <NUM> and a CO2 emission. <FIG> illustrates a CO2 emission under six kinds of control, that is, control to apply heat for air heating singly by the boiler unit <NUM>, control to apply heat for air heating singly by the heat pump unit <NUM>, control for "running cost first" in the third period of time, control for "power consumption limit" in the first period of time based on the control for "running cost first" in the third period of time, control for "CO2 emission first" in the second period of time, and control for "power consumption limit" in the first period of time based on the control for "CO2 emission first" in the second period of time. As illustrated in <FIG>, assuming that the CO2 emission under the control to apply heat for air heating singly by the boiler unit <NUM> is <NUM>, the CO2 emissions under the remaining five kinds of control are respectively <NUM>, <NUM>, <NUM>, <NUM>, and <NUM>. It should be noted that the graph of <FIG> shows an average value of numerical values at some typical outside temperatures.

According to the heating system <NUM>, the operation control unit <NUM> controls the operation of the heat pump unit <NUM> to maintain the power consumption at a value below the upper limit value (e.g., the upper limit of power consumption in <FIG>) in the first period of time during which the power consumption is restricted to a value below the upper limit value. This configuration reduces the power consumption by the heat pump unit <NUM> during peak hours of electric power supply by the power company 1a in the region where the heating system <NUM> is installed, and keeps a balance between a supply of electricity and a demand for electricity in the region.

According to the heating system <NUM>, in addition, the operation control unit <NUM> causes the boiler unit <NUM> to carry out the operation for a supplemental purpose when the amount of heat applied to the working fluid by the heat pump unit <NUM> is insufficient in the first period of time in which the power management apparatus <NUM> of the power company 1a issues a "control request" (i.e., the electric power adjustment period). This configuration allows the user of the heating system <NUM> to enjoy air heating, hot water supply, and the like without considerable deterioration in comfort.

According to the heating system <NUM>, the upper limit value acquisition unit <NUM> acquires the information about the upper limit value of the power consumption, from the power management apparatus <NUM> of the power company 1a that supplies electric power to the heat pump unit <NUM>. This configuration allows the user or manager of the heating system <NUM> to give cooperation to the power company 1a which as an electricity supplier, as to achievement in the balance between the supply of electricity and the demand for electricity in the region.

Typically, the emission of carbon dioxide from the heat pump unit <NUM> during operation is smaller than the emission of carbon dioxide from the boiler unit <NUM> during operation. In view of this respect, according to the heating system <NUM>, the operation control unit <NUM> causes the heat pump unit <NUM> to carry out the operation preferentially under the control for "CO2 emission first" in the second period of time and causes the boiler unit <NUM> to carry out the operation in the first period of time during which the power consumption by the heat pump unit <NUM> is restricted to a value below the upper limit value, by the insufficient amount of heat owing to the restriction on the power consumption to a value below the upper limit value. This configuration allows the heating system <NUM> to effectively contribute to reduction in emission of carbon dioxide on a global scale.

According to the heating system <NUM>, the operation control unit <NUM> controls the operation of the heat pump unit <NUM> and the operation of the boiler unit <NUM> so as to reduce the total emission of carbon dioxide in the second period of time during which the power consumption is not necessarily restricted to a value below the upper limit value. This configuration allows the heating system <NUM> to effectively contribute to reduction in emission of carbon dioxide on a global scale even in the second period of time.

In the heating system <NUM>, basically, the periods of time other than the first period of time are set at the second period of time. However, the user is able to change a part of the second period of time or the entire second period of time to the third period of time. In the third period of time, the operation control unit <NUM> causes the heat pump unit <NUM> and the boiler unit <NUM> to carry out the operations so as to reduce the sum of the first running cost, which is an electricity rate, of the heat pump unit <NUM> and the second running cost, which is a fuel charge, of the boiler unit <NUM>. As described above, the heating system <NUM> is capable of carrying out the operation for "running cost first" by changing a part of the second period of time or the entire second period of time during which the control for "CO2 emission first" is performed, to the third period of time in accordance with the need of the user. This configuration allows the user to enjoy a merit of cost reduction. The heating system <NUM> enables achievement in balance between the supply of electricity and the demand for electricity in the region in the first period of time.

In the foregoing embodiment, the present disclosure is directed to each heating system <NUM> configured to heat air in a room with the working fluid, such as water, that circulates through the flow circuit 203a. The present disclosure may alternatively be directed to, as illustrated in <FIG>, an air conditioning system <NUM> configured to carry out a heating operation by heating air with a heat pump <NUM> and a combustion apparatus <NUM>.

As illustrated in <FIG> and <FIG>, the air conditioning system <NUM> mainly includes the heat pump <NUM> including a refrigerant circuit in which a refrigerant is sealed, the combustion apparatus <NUM> configured to generate heat with flame, and a fan <NUM> configured to send, to rooms R1, air heated by the heat pump <NUM> and the combustion apparatus <NUM>.

The air conditioning system <NUM> includes a first unit 1A accommodating utilization-side components of the heat pump <NUM>, combustion apparatus <NUM>, and fan <NUM>, and a second unit 1B accommodating a heat source-side component of the heat pump <NUM>. The first unit 1A includes, for example, a utilization-side heat exchanger <NUM> of the heat pump <NUM>, a furnace heat exchanger <NUM> of the combustion apparatus <NUM>, and the fan <NUM>. The first unit 1A has an opening (an air outlet H1) for sending air. The air outlet H1 communicates with one end of a duct D1. The first unit 1A also has an opening (an air inlet H2) for taking in air to be sucked into the fan <NUM>. The second unit 1B includes a heat source-side heat exchanger <NUM> of the heat pump <NUM>. One of or both the first unit 1A and the second unit 1B is or are each equipped with a microcomputer for controlling operations of the respective units of the air conditioning system <NUM>, and various electric components.

In the air conditioning system <NUM>, the first unit 1A, the second unit 1B, and refrigerant connection pipes <NUM> and <NUM> constitute the refrigerant circuit in the heat pump <NUM>. The heat pump <NUM> is configured, during operation, to heat or cool air to be sent to the duct D1, by a vapor compression refrigeration cycle achieved in the refrigerant circuit. The combustion apparatus <NUM> is configured to heat air to be sent to the duct D1, with a heat source different from the heat pump <NUM> (specifically, heat generated by fuel combustion).

The air conditioning system <NUM> may be installed in a building, such as a house, in various manners including a duct split type and a rooftop type. For example, in a case where the air conditioning system <NUM> is installed in a house <NUM> as illustrated in <FIG>, the first unit 1A and the second unit 1B are disposed separately. In the example illustrated in <FIG>, the first unit 1A is installed in a basement B1, the second unit 1B is installed outside, and the first unit 1A and the second unit 1B are connected with the refrigerant connection pipes <NUM> and <NUM>. In <FIG>, dashed arrows indicate a direction of air flowing from the air conditioning system <NUM> to the rooms R1 through the duct D1.

The air conditioning system <NUM> illustrated in <FIG> and <FIG>, as in the foregoing heating system <NUM>, reduces power consumption by the heat pump <NUM> during peak hours of electric power supply, and keeps a balance between a supply of electricity and a demand for electricity in a region. According to the air conditioning system <NUM>, in addition, when an amount of heat applied to a working fluid only by the heat pump <NUM> is insufficient, the combustion apparatus <NUM> carries out an operation for a supplemental purpose. This configuration therefore allows a user to enjoy air heating without considerable deterioration in comfort.

In the foregoing embodiment, the power meter <NUM> is disposed in each of the buildings A and B, and the control device <NUM> controls each appliance <NUM> in response to a "control request" issued from the control request issuance unit 15d of the power management apparatus <NUM>. This configuration keeps the balance between the supply of electricity and the demand for electricity in the region. Each heating system <NUM> itself does not include a power meter device. In restricting the power consumption by the heating system <NUM> to a value below the predetermined upper limit value, the heating system <NUM> estimates the power consumption by the heat pump unit <NUM> from, for example, the capacity of the compressor.

Each heating system <NUM> itself may alternatively include a power meter <NUM> and may cause the heat pump unit <NUM> to carry out the operation to maintain a measured value of the power meter <NUM> at a value below the upper limit value of the power consumption by the heat pump unit <NUM>.

In the foregoing embodiment, the power management apparatus <NUM> of the power company 1a issues a "control request" for encouraging an adjustment to electric power usage, to the control device <NUM> in each of the buildings A and B. However, a service entity for achieving a balance between a supply of electricity and a demand for electricity is not limited to the power company 1a. For example, an aggregator may serve as an energy management service entity. The aggregator refers to a service provider that issues a "control request" for encouraging an adjustment to electric power usage, to an electricity consumer, such as each of the buildings A and B, in response to instructions for power saving and output control from a power company. In this case, the upper limit value acquisition unit <NUM> of each heating system <NUM> indirectly acquires the "control request" for encouraging an adjustment to electric power usage, from the aggregator.

Also in the foregoing embodiment, the control device <NUM> and heating system <NUM> in each of the buildings A and B are connected to the power management apparatus <NUM> of the power company 1a via the Internet 101a. However, the control device <NUM> and the heating system <NUM> are not necessarily connected to the power management apparatus <NUM>. In the case where the control device <NUM> and the heating system <NUM> are not connected to the power management apparatus <NUM>, a "control request" for encouraging an adjustment to, for example, electric power usage for the next day is input manually to the control device <NUM> or the heating system <NUM>.

In the foregoing embodiment, each upper limit value acquisition unit <NUM> indirectly acquires the upper limit value of the power consumption by the corresponding heating system <NUM>, from the power management apparatus <NUM> of the power company 1a.

Alternatively, each heating control unit <NUM> may include a second calculation unit <NUM> (see a dashed line in <FIG>) configured to calculate an upper limit value of power consumption by the corresponding heating system <NUM> so as to reduce a total emission of carbon dioxide. The second calculation unit <NUM> may be disposed as a functional block practicable by the control computation device of the heating control unit <NUM>. Information for the calculation of the upper limit value of the power consumption by the heating system <NUM> is preferably stored in the storage unit <NUM> in advance; however, the user may alternatively input this information manually.

It is typically recognized that carbon dioxide is emitted in large amounts from the boiler unit <NUM>. In addition, carbon dioxide is also emitted in generating (producing) electric power to be consumed by the heat pump unit <NUM>. Furthermore, carbon dioxide is emitted upon thermal power generation since oil is burned, and carbon dioxide is also emitted in manufacturing a power generation apparatus that uses natural energy. In view of these respects, according to Modification D, the second calculation unit <NUM> calculates the upper limit value of the power consumption, so as to reduce the total emission of carbon dioxide. According to Modification D, a heating system including the second calculation unit <NUM> is capable of effectively contributing to reduction in emission of carbon dioxide on a global scale even in a case where the heating system is not connected to, for example, the power management apparatus <NUM> of the power company 1a.

In the foregoing embodiment, the fluid to be heated is water; however, an antifreeze may be used in place of water.

While various embodiments of a fluid heating system have been described herein above, it is to be appreciated that various changes in form and detail may be made without departing from the scope of the appended claims.

Claim 1:
A fluid heating system (<NUM>) comprising:
a heat pump apparatus (<NUM>) including a refrigerant circuit (<NUM>) through which a refrigerant circulates, the heat pump apparatus being configured to carry out an operation with electric power supplied by a power company having power generation plants;
a flow path (203a) through which a fluid heated with the refrigerant flows;
a combustion apparatus (<NUM>) including a combustion unit (<NUM>), the combustion apparatus being configured to carry out an operation of heating the fluid, separately from the heat pump apparatus; and
a control unit (<NUM>) including
an upper limit value acquisition unit (<NUM>) configured to acquire an upper limit value of power consumption by the heat pump apparatus, and
an operation control unit (<NUM>) configured to control the operation of the heat pump apparatus to maintain the power consumption at a value below the upper limit value, and configured to cause the combustion apparatus to carry out the operation when an amount of heat applied to the fluid by the heat pump apparatus is insufficient, characterized in that:
the power consumption is restricted to the value below the upper limit value during a first period of time;
the combustion apparatus is caused to carry out the operation on condition that the amount of heat applied to the fluid by the heat pump apparatus is insufficient in the first period of time;
the control unit is configured to periodically receive information on an emission of carbon dioxide in producing electric power per unit supply power,
the emission of carbon dioxide in producing electric power per unit supply power varying depending on the number of the power generation plants in operation and the operating rate of each operating power generation plant;
the fluid heating system further comprises
a first calculation unit configured to calculate a total emission of carbon dioxide corresponding to a sum of an emission of carbon dioxide from the heat pump apparatus during the operation and an emission of carbon dioxide from the combustion apparatus during the operation, based on the information on the emission of carbon dioxide in producing electric power per unit supply power, and
a second calculation unit configured to calculate the upper limit value so as to reduce the total emission of carbon dioxide; and
the upper limit value acquisition unit is configured to acquire the upper limit value from the second calculation unit.