Patent Description:
With the development of technologies and the improvement of people's living standards, users have higher and higher requirements on refrigerators. A conventional refrigerator provided with only a refrigeration chamber, a freezing chamber and a variable-temperature chamber can no longer meet the diversified needs of users on storage spaces.

Prior art document <CIT> teaches an anti-condensation control method for a refrigerator, and a refrigerator using the anti-condensation control method.

<CIT>) discloses a sectorized cooling arrangement for refrigerators housing products, wherein the arrangement has a direct access to the products without having to open a cooling chamber of the refrigerator, which arrangement has a compartment defining sectorized housings and air passage regulators between the cooling chamber of the refrigerator and the compartment.

Further relevant prior art document is <CIT>.

In recent years, a composite door technology has emerged in the field of refrigerators. It is known to all that a conventional refrigerator door body is used to open or close a refrigerating chamber of a refrigerator body, and at most a bottle holder for placing bottled products is disposed at a lining of a refrigeration door body. However, a refrigerator with a composite door body is improved in structure and function of the door body, where the door body includes a main door and a secondary door, and the main door is used to open or close the refrigerating chamber. In addition, the main door defines a door chamber with an open front side, and the secondary door is used to open or close the door chamber. During rotation of the main door, the secondary door is kept closed. The door chamber may be used to place to-be-stored objects, and a user just needs to open the secondary door to take or put objects without opening the main door. This achieves more convenient and more efficient operation, and also avoids excessive loss of cold energy caused by frequent opening of the main door.

However, in an operating process of a composite door type refrigerator, frequent occurrence of condensation on the inner wall of the door chamber affects user experience and hinders further development of the composite door technology. Therefore, how to reduce or avoid condensation on the inner wall of the door chamber has become a technical problem to be solved urgently in the art.

The present invention is disclosed in the independent claims <NUM> and <NUM>.

The present invention aims to reduce or avoid condensation on an inner wall of a door chamber.

The present invention further aims to avoid adverse effects of temperature and humidity fluctuation in a refrigerator body chamber on a temperature and a humidity in the door chamber. However, the claimed subject-matter is defined by the claims.

The refrigerator and the control method therefor provided by the present invention, to a certain extent, solve the problem that condensation easily occurs on the inner wall of the second chamber defined by the door body in a composite door type refrigerator. Specifically, the inventors have realized that one significant reason for probable occurrence of condensation on the inner wall of the second chamber is that high-humidity air is introduced from the first chamber of the refrigerator body. Especially when the first chamber is just opened or closed, external air with relatively high humidity and temperature enters the first chamber, and if the air subsequently enters the second chamber, it is easy to produce condensation on the inner wall of the second chamber. Therefore, according to the present invention, before cold air in the first chamber is introduced into the second chamber, the expected relative humidity ϕ<NUM> of the air in the first chamber when the temperature changes to the air temperature T<NUM> in the second chamber, and the relative air humidity threshold ϕ<NUM> at which the air begins to condense on the inner wall of the second chamber (when the relative humidity of the air around the inner wall of the second chamber is higher than the relative air humidity threshold ϕ<NUM>, condensation will be absolutely produced on the inner wall) are calculated and determined first and then are compared; only when ϕ<NUM><ϕ<NUM>, the air supply port is enabled to supply air to the second chamber; otherwise, the air supply port is enabled to stop supplying air to the second chamber, thereby avoiding the problem about production of condensation on the inner wall of the second chamber caused by introduction of the cold air from the first chamber to the second chamber immediately after the first chamber is just opened or closed or after other operations that cause increase of the air humidity in the first chamber. In addition, according to the present invention, the external high-humidity and high-temperature air can be prevented from entering the second chamber after the first chamber is opened or closed, so that adverse effects of temperature fluctuation in the first chamber on a temperature and a humidity in the second chamber are prevented as well. In this way, the temperature and humidity of the air in the second chamber are kept at a reasonable level.

According to the present invention, before the air in the first chamber enters the second chamber, the expected relative humidity ϕ<NUM> of the air in the first chamber when the temperature changes to T<NUM> after the air enters the second chamber is predicted based on the absolute air humidity ρ<NUM> in the first chamber and the air temperature T<NUM>, so as to determine whether condensation will be produced on the inner wall of the second chamber after the air enters the second chamber. Such calculation manner ingeniously realizes prediction on a condensation condition and avoids production of condensation.

Further, in the refrigerator and the control method therefor provided by the present invention, the distances from the detection point of the air temperature T<NUM> in the first chamber, the detection point of the relative air humidity ϕ<NUM> in the first chamber, the temperature detection point on the rear wall of the second chamber, and the detection point of the air temperature T<NUM> of the second chamber to the air supply port are limited to make sure that the above detection points are closer to the air supply port, so that temperature and humidity detection is specially performed on an air flow that first enters the air supply port in a later period, thereby achieving more accurate prediction on whether condensation will be produced after the air flow in the first chamber flows into the second chamber.

Persons skilled in the art can more clearly understand the above and other purposes, advantages and features of the present invention according to detailed description of specific embodiments of the present invention with reference to the accompanying drawings.

Some specific embodiments of the present invention are described below in detail in an exemplary and unlimited way with reference to the accompanying drawings. The same or similar components or parts are indicated by the same reference numerals in the drawings. Persons skilled in the art should understand that these drawings are not necessarily drawn to scale. In the drawings:.

<FIG> is a schematic structural diagram of a refrigerator according to an embodiment of the present invention. <FIG> is a schematic block diagram of a refrigerator according to an embodiment of the present invention.

An embodiment of the present invention provides a control method for a refrigerator. As shown in <FIG> and <FIG>, the refrigerator according to claim <NUM> includes a refrigerator body <NUM>, a door body <NUM> and a controller <NUM>.

A front side of the refrigerator body <NUM> is opened to define a first chamber <NUM>. The door body <NUM> includes a main door <NUM> and a secondary door <NUM>, where the main door <NUM> is configured to open or close the first chamber <NUM> and defines a second chamber <NUM>, the secondary door <NUM> is configured to open or close the second chamber <NUM>, and a rear side of the main door <NUM> is provided with an air supply port <NUM> configured to introduce cold air in the first chamber <NUM> into the second chamber <NUM>. After cold air enters the second chamber <NUM>, the second chamber <NUM> is refrigerated. The main door <NUM> may be rotatably mounted on the refrigerator body <NUM> at the front side of the refrigerator body <NUM>; and a front side of the main door <NUM> is opened to define the second chamber <NUM>, and the secondary door <NUM> is rotatably mounted on the main door <NUM> at the front side of the main door <NUM>. When the main door <NUM> is opened, a user stores or gets objects in the first chamber <NUM>. When the main door <NUM> is closed and the secondary door <NUM> is opened, a user can store or get objects in the second chamber <NUM>. The controller <NUM> includes a processor <NUM> and a memory <NUM>, where the memory <NUM> stores a computer program <NUM>, and when the computer program <NUM> is executed by the processor <NUM>, the control method for a refrigerator according to claim <NUM> is implemented.

The refrigerator can perform refrigeration through a vapor compression refrigeration circulation system, a semiconductor refrigeration system, or other ways. According to differences of refrigeration temperatures, the chambers inside the refrigerator may be classified into a refrigeration chamber, a freezing chamber and a variable-temperature chamber. For example, a temperature in the refrigeration chamber is generally controlled between <NUM> and <NUM>, preferably between <NUM> and <NUM>. A temperature in the freezing chamber is generally controlled between -<NUM> and -<NUM>. A temperature in the variable-temperature chamber may be adjusted between -<NUM> and <NUM> so as to realize a temperature variation effect. Different types of objects should be stored at different optimal storage temperatures, and also should be stored in different storage chambers. For example, fruit and vegetable foods are suitable for being stored in a refrigeration chamber, while meat foods are suitable for being stored in a freezing chamber.

In some embodiments, the first chamber <NUM> is a refrigeration chamber. In addition, the air supply port <NUM> may be disposed at the top of the rear side of the main door <NUM>, and the bottom of the rear side of the main door <NUM> is further provided with an air return port <NUM> for enabling air in the second chamber <NUM> to flow to the first chamber <NUM>. After flowing from the air supply port <NUM> into the second chamber <NUM>, cold air, due to its relatively large density, sinks and flows down to sequentially refrigerate regions at all heights of the second chamber <NUM>, and the air flows back to the first chamber <NUM> via the air return port <NUM> at the bottom of the second chamber <NUM> after the temperature of the air rises gradually. In this way, smoother air path circulation is formed, which improves a refrigeration effect of the second chamber <NUM>. It can be understood that air returning can be implemented by the air supply port <NUM> if no air return port <NUM> is provided.

<FIG> is a schematic diagram of a control method for a refrigerator according to an embodiment of the present invention. The control method for a refrigerator according to this embodiment of the present invention is applicable to the refrigerators according to all the foregoing embodiments of the present invention. As shown in <FIG>, the control method for a refrigerator according to claim <NUM> includes:
Step S302: acquiring an absolute air humidity ρ<NUM> of the first chamber <NUM> and an air temperature T<NUM> of the second chamber <NUM>.

In step S302, the absolute air humidity ρ<NUM> of the first chamber <NUM> may be directly measured. However, the absolute air humidity ρ<NUM> is preferably indirectly obtained through calculation, so that a more accurate result can be obtained. Specifically, an air temperature T<NUM> in the first chamber <NUM> and a relative air humidity ϕ<NUM> in the first chamber <NUM> are detected first, and the absolute air humidity ρ<NUM> is calculated based on the air temperature T<NUM> and the relative air humidity ϕ<NUM>.

Step S304: calculating an expected relative humidity ϕ<NUM> of air in the first chamber <NUM> when the temperature changes to T<NUM> based on the absolute air humidity ρ<NUM> and the air temperature T<NUM>. In addition, a relative air humidity threshold ϕ<NUM> at which air in the second chamber <NUM> begins to condense on an inner wall of the second chamber <NUM> is determined.

It can be learned by persons skilled in the art that an absolute humidity of moist air (air containing vapor) refers to a mass of vapor contained in unit volume of moist air. Under a specified air pressure and a specified temperature, the vapor in unit volume of air has an upper limit. If the vapor in this volume of air exceeds the upper limit, that is, a maximum absolute humidity is reached, vapor condensation may occur. A relative humidity of moist air refers to a ratio of an absolute humidity of the moist air at a specified temperature to a reachable maximum absolute humidity of the moist air at the same temperature, and the ratio is a percentage. With a higher temperature, air can contain more vapor. Therefore, when an absolute humidity of moist air is unchanged, a relative humidity of the moist air will change dependent on temperature.

Accordingly, in step S304, the expected relative humidity ϕ<NUM> refers to a final relative humidity of an input air flow with an absolute humidity ρ<NUM> in the first chamber <NUM> as the temperature changes to be the same as the air temperature (namely T<NUM>) in the second chamber (<NUM>) when the input air flow exchanges heat with the air in the second chamber <NUM> after entering the second chamber <NUM>. A relative humidity threshold refers to a minimum relative humidity at which condensation is produced by the air on the inner wall of the second chamber <NUM> when the air temperature is T<NUM>, that is, a maximum relative humidity that enables the inner wall of the second chamber <NUM> to be kept with no condensation. When a relative humidity of the air around the inner wall of the second chamber <NUM> is higher than the relative air humidity threshold ϕ<NUM>, condensation may be produced on the inner wall.

Step S306: comparing the expected relative humidity ϕ<NUM> with the relative air humidity threshold ϕ<NUM>.

Step S308: If ϕ<NUM><ϕ<NUM>, enabling the air supply port <NUM> to supply air to the second chamber <NUM>, otherwise enabling the air supply port <NUM> to stop supplying air to the second chamber <NUM>.

Preferably, a fan <NUM> is mounted at the air supply port <NUM>. In step S308, if ϕ<NUM><ϕ<NUM>, the fan <NUM> is turned on to enable the air supply port <NUM> to supply air to the second chamber <NUM>, otherwise the fan is turned off to enable the air supply port <NUM> to stop supplying air to the second chamber <NUM>. In some alternative embodiments, a damper may be disposed at the air supply port <NUM>, and the damper is controlled to open or close so as to start or stop air supply to the second chamber <NUM>. Alternatively, the fan <NUM> and the damper are both provided, and the fan <NUM> and the damper are controlled to open or close simultaneously, so as to realize more accurate control on an air supply state of the air supply port <NUM>.

The above steps in this embodiment of the present invention are cyclically implemented. In other words, after the air supply port <NUM> is opened for air supply or stops air supply, step S302 to step S308 need to be implemented again, so that an open/close state of the air supply port <NUM> can be adjusted as soon as possible based on temperature and humidity changes of the first chamber <NUM> and the second chamber <NUM>.

The control method in this embodiment of the present invention, to a certain extent, solves the problem that condensation easily occurs on the inner wall of the second chamber <NUM> defined by the door body <NUM> in a composite door type refrigerator. Specifically, the inventors have realized that a significant reason for probable occurrence of condensation on the inner wall of the second chamber <NUM> is that high-humidity air is introduced from the first chamber <NUM> of the refrigerator body <NUM>. Especially when the first chamber <NUM> is just opened or closed, external air with relatively high humidity and temperature enters the first chamber <NUM>, and if the air subsequently enters the second chamber <NUM>, it is easier to produce condensation on the inner wall of the second chamber <NUM>. Therefore, according to the present invention, before cold air in the first chamber <NUM> is introduced into the second chamber <NUM>, the expected relative humidity ϕ<NUM> of the air in the first chamber <NUM> when the temperature changes to the air temperature T<NUM> in the second chamber <NUM>, and the relative air humidity threshold ϕ<NUM> at which the air begins to condense on the inner wall of the second chamber <NUM> are calculated first and are compared; only when ϕ<NUM><ϕ<NUM>, the air supply port <NUM> is enabled to supply air to the second chamber <NUM>; otherwise, the air supply port <NUM> is enabled to stop supplying air to the second chamber <NUM>, thereby avoiding the problem about production of condensation on the inner wall of the second chamber <NUM> caused by introduction of the cold air from the first chamber <NUM> to the second chamber <NUM> immediately after the first chamber <NUM> is just opened or closed or after other operations that cause increase of the air humidity in the first chamber <NUM>. According to the present invention, the external high-humidity and high-temperature air can be prevented from entering the second chamber <NUM> after the first chamber <NUM> is opened or closed, so that adverse effects of temperature fluctuation in the first chamber <NUM> on a temperature and a humidity in the second chamber <NUM> are prevented as well. In this way, the temperature and humidity of the air in the second chamber <NUM> are kept at a reasonable level.

According to the present invention, before the air in the first chamber <NUM> enters the second chamber <NUM>, the expected relative humidity ϕ<NUM> of the air in the first chamber <NUM> when the temperature changes to T<NUM> after the air enters the second chamber <NUM> is predicted based on the absolute air humidity ρ<NUM> in the first chamber <NUM> and the air temperature T<NUM>, so as to determine whether condensation will be produced on the inner wall of the second chamber <NUM> after the air enters the first chamber <NUM>. Such calculation manner ingeniously realizes prediction on a condensation condition and avoids production of condensation. The following describes in detail the control method for a refrigerator according to this embodiment in conjunction with introduction of an optional execution procedure of this embodiment. This embodiment is merely an example of the execution procedure.

<FIG> is a flowchart of a control method for a refrigerator according to an embodiment of the present invention. As shown in <FIG>, the control method for a refrigerator according to claim <NUM> may include the following steps:
Step S402: detecting an air temperature T<NUM> in the first chamber <NUM>, a relative air humidity ϕ<NUM> in the first chamber <NUM>, an air temperature T<NUM> in the second chamber <NUM>, and an air temperature T<NUM> of the inner wall of the second chamber <NUM>.

In this step, as shown in <FIG> and <FIG>, a first temperature sensor <NUM> is configured to detect the air temperature T<NUM> in the first chamber <NUM>; a relative humidity sensor <NUM> is configured to detect the relative air humidity ϕ<NUM> in the first chamber <NUM>; a second temperature sensor <NUM> is configured to detect the air temperature T<NUM> in the second chamber <NUM>; and a third temperature sensor <NUM> may be configured to detect the air temperature T<NUM> of the inner wall of the second chamber <NUM>. The first temperature sensor <NUM>, the relative humidity sensor <NUM>, the second temperature sensor <NUM> and optionally the third temperature sensor <NUM> are all connected to the controller <NUM>, so as to transmit detection signals to the controller <NUM>.

In this step, a temperature of the rear wall <NUM> of the second chamber <NUM> is detected, and is taken as the temperature T<NUM> of the inner wall. The inventors have realized that the rear wall <NUM> of the second chamber <NUM> is close to the first chamber <NUM>, and can transfer heat with the air in the first chamber <NUM> through heat conduction; therefore, the temperature of the rear wall <NUM> is lower than those at other wall surfaces of the second chamber <NUM>, and it is easier to produce condensation. As long as no condensation is produced on the rear wall <NUM>, it can be basically guaranteed that no condensation is produced on the other wall surfaces. Therefore, in this embodiment, only the temperature of the rear wall is detected, thereby better avoiding condensation.

Step S404: calculating an absolute air humidity ρ<NUM> in the first chamber <NUM> based on the air temperature T<NUM> in the first chamber <NUM> and the relative air humidity ϕ<NUM> in the first chamber <NUM>. A specific calculation manner for calculating an absolute humidity based on an air temperature and a relative humidity is known by all persons skilled in the art, and belongs to basic knowledge commonly used in the field of refrigeration. Specifically, the absolute humidity can be calculated according to a formula or obtained by querying in a table, which does not need to be described in detail herein.

Step S406: calculating an expected relative humidity ϕ<NUM> of the air in the first chamber <NUM> when the temperature changes to T<NUM> based on the absolute air humidity ρ<NUM> and the air temperature T<NUM>.

Step S408: calculating a relative air humidity threshold ϕ<NUM> based on a correspondence relationship of a dew-point temperature, an ambient temperature and a relative humidity by taking the temperature T<NUM> of the inner wall of the second chamber <NUM> as the dew-point temperature and the air temperature T<NUM> as the ambient temperature. Specifically, the "correspondence relationship of a dew-point temperature, an ambient temperature and a relative humidity" is known by all persons skilled in the art, belongs to basic knowledge commonly used in the field of refrigeration, and specifically includes a computational formula and a relationship table, which do not need to be described in detail herein. Step S404 and step S408 are both steps after step S402.

Step S410: determining whether ϕ<NUM><ϕ<NUM> is valid. If ϕ<NUM><ϕ<NUM> is valid, step S412 is implemented; otherwise, step S414 is implemented.

Step S412: turning on the fan <NUM>. A purpose for turning on the fan <NUM> is to enable the air supply port <NUM> to supply air to the second chamber <NUM>.

Step S414: turning off the fan <NUM>. A purpose for turning off the fan <NUM> is to enable the air supply port <NUM> to stop supplying air to the second chamber <NUM>.

The above steps in this embodiment are cyclically implemented. That is, after step S412 and step S414 are implemented, step S402 is implemented again to form a cycle. In this way, an open/close state of the air supply port <NUM> can be adjusted as soon as possible according to temperature and humidity changes of the first chamber <NUM> and the second chamber <NUM>.

Claim 1:
A control method for a refrigerator, wherein the refrigerator comprises a refrigerator body (<NUM>) having a front side opened to define a first chamber (<NUM>), and a door body (<NUM>) configured to open or close the first chamber (<NUM>); the door body (<NUM>) comprises a main door (<NUM>) and a secondary door (<NUM>); the main door (<NUM>) is configured to open or close the first chamber (<NUM>) and defines a second chamber (<NUM>); the secondary door (<NUM>) is configured to open or close the second chamber (<NUM>); a rear side of the main door (<NUM>) is provided with an air supply port (<NUM>) configured to introduce cold air from the first chamber (<NUM>) into the second chamber (<NUM>); characterized in that the control method comprises:
acquiring an absolute air humidity ρ<NUM> of the first chamber (<NUM>) and an air temperature T<NUM> of the second chamber (<NUM>);
calculating an expected relative humidity ϕ<NUM> of air in the first chamber (<NUM>) when the temperature changes to T<NUM> based on the absolute air humidity ρ<NUM> and the air temperature T<NUM>;
determining a relative air humidity threshold ϕ<NUM> at which air in the second chamber (<NUM>) begins to condense on an inner wall of the second chamber (<NUM>);
comparing the expected relative humidity ϕ<NUM> with the relative air humidity threshold ϕ<NUM>; and
if ϕ<NUM><ϕ<NUM>, enabling the air supply port (<NUM>) to supply air to the second chamber (<NUM>), otherwise enabling the air supply port (<NUM>) to stop supplying air to the second chamber (<NUM>).