A phase change material cold storage refrigerator and a control method thereof

Abstract

The existing phase change material is slow in temperature reduction in the starting stage and inconsistent in power consumption in the stopping stage when used in a refrigerator. The application provides a phase change material cold storage refrigerator, which comprises a chamber, a foaming layer and an air duct. The chamber has a shelf assembly. The shelf assembly comprises a plurality of shelves. The shelves have phase change materials. The phase change temperatures of each layer of phase change materials are different. The phase change materials have heat pipes. The heat pipes comprise evaporation sections and condensation sections. The phase change materials are in contact with the evaporation sections. The condensation sections are in rotatable liquid storage bags. The rotatable liquid storage bags are in the foaming layer. The refrigerator has a temperature sensor. The temperature sensor, a controller and the rotatable liquid storage bag are sequentially connected. The air duct has a fan and an evaporator. The evaporator is connected with the rotatable liquid storage bag or a compressor. The rotatable liquid storage bag is connected with the compressor. The compressor, a condenser, a capillary tube and the evaporator are sequentially connected. The rotatable liquid storage bag is connected with a motor. The effect of high uniformity of the temperature of the chamber of the refrigerator is achieved.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of refrigeration, and particularly relates to a phase change material cold storage refrigerator and a control method thereof. BACKGROUND

[0002] The refrigerator is one of household electrical appliances with high energy consumption, and the cold loss of the existing product mainly comes from the opening door, the cold loss of the cabinet, defrosting and the large temperature difference caused by the uneven temperature distribution in the internal space of the refrigerator. The heat load of the refrigerator is increased, and the compressor of the refrigerator is frequently started and stopped. With the wide use of the cold storage technology in the refrigeration and freezing field, the phase change material is used to absorb the excessive cold released by the refrigeration system, and the cold is released when the system load is increased including the loss or shutdown, so that the temperature fluctuation of the compartment of the refrigerator is reduced, the starting and stopping frequency of the compressor is reduced, and the purpose of energy saving is achieved.

[0003] After the refrigerator is stopped, the compartment stops cooling, and the air in the compartment appears the phenomenon that the cold air sinks and the hot air floats due to the natural convection. The air in the compartment presents the distribution state that the air temperature at the top is high and the air temperature at the bottom is low, and the temperature difference can reach more than 3 DEG C, which has a certain influence on the food quality. When the phase change material is used in the refrigerator, the temperature is slowly reduced in the starting stage, and the consumption rate is inconsistent in the shutdown stage. SUMMARY

[0004] 1. Technical problem to be solved

[0005] After the refrigerator is stopped, the compartment stops cooling, and the air in the compartment appears the phenomenon that the cold air sinks and the hot air floats due to the natural convection. The air in the compartment presents the distribution state that the air temperature at the top is high and the air temperature at the bottom is low, and the temperature difference can reach more than 3 DEG C, which has a certain influence on the food quality. When the phase change material is used in the refrigerator, the temperature is slowly reduced in the starting stage, and the consumption rate is inconsistent in the shutdown stage.

[0006] 2. Technical scheme

[0007] In order to achieve the above-mentioned purpose, the application provides a phase change material cold storage refrigerator, which comprises a chamber, a foaming layer arranged outside the chamber, an air duct arranged between the chamber and the foaming layer, a shelf assembly arranged in the chamber, the shelf assembly comprising a plurality of shelves, phase change materials arranged in the shelves, the phase change temperatures of the phase change materials in different layers being different, heat pipes arranged in the phase change materials, one end of the heat pipes being an evaporation section, the other end of the heat pipes being a condensation section, the phase change materials being in contact with the evaporation section, the condensation section being arranged in a rotatable liquid storage bag, the rotatable liquid storage bag being arranged in the foaming layer, a temperature sensor arranged in the refrigerator, the temperature sensor being connected with a controller, the rotatable liquid storage bag being connected with the controller, a fan and an evaporator arranged in the air duct, the evaporator being connected with the rotatable liquid storage bag or a compressor, the rotatable liquid storage bag being connected with the compressor, the compressor, a condenser, a capillary tube and the evaporator being sequentially connected, and the rotatable liquid storage bag being connected with a motor.

[0008] Another embodiment provided by the application is that fins are arranged in the shelves, and the fins are connected with the evaporation section.

[0009] Another embodiment provided by the application is that the fins are sawtooth-shaped.

[0010] Another embodiment provided by the application is that the shelves are three layers, the refrigerator is divided into four parts by the three layers of shelves, the average air temperature difference of each layer is b℃, the average air temperatures of the four parts from top to bottom after the refrigerator stops are x, x-b, x-2b and x-3b, the phase change temperatures of the phase change materials in different layers are different, and the mass ratio of the phase change materials is calculated according to the different phase change temperatures.

[0011] Another embodiment provided by the application is that the position of the rotatable liquid storage bag is higher than that of the shelf assembly.

[0012] Another embodiment provided by the application is that the refrigerant in the rotatable liquid storage bag does not reach the condensation section, the liquid level of the refrigerant is controlled by the motor, and the condensation section is three, the directions of the three condensation sections are upward, horizontal and downward respectively.

[0013] Another embodiment provided by the application is that the heat pipes in the first layer are driven by capillary force, the heat pipes in the second layer are driven by gravity, and the heat pipes in the third layer are driven by gravity.

[0014] Another embodiment provided by the application is that the evaporator is connected with the rotatable liquid storage bag or the compressor through a three-way valve.

[0015] This application also provides a control method for the aforementioned phase change material cold storage refrigerator. The method includes setting a maximum temperature Tr1 and a minimum temperature Tr2 for each compartment, and a phase change temperature of Tp1 for the first layer of phase change material. After the refrigerator is powered on, the temperature Tp of the phase change material shelf interlayer and the temperature Tr of the refrigerator compartment are monitored simultaneously to determine the connection strategy between the fan and evaporator and the rotatable liquid storage tank or the compressor. When both Tp and Tr are greater than the set values ​​Tp1 and Tr2, the refrigerator operates normally, the fan is turned on, and the refrigerant flows to the rotatable liquid storage tank. When Tr is less than the set value Tr1, and Tp is greater than the set value Tp1, the fan is turned off to prevent the air in the compartment from becoming too cold and affecting food quality, and the refrigerant flows to the rotatable liquid storage tank. When Tr is greater than the set value Tr2, and Tp is less than the set value Tp1, the fan is turned on to continue cooling the compartment, and the refrigerant flows to the compressor inlet to reduce the system's additional power consumption. When both Tp and Tr are less than the set values ​​Tp1 and Tr2, the refrigerator stops.

[0016] Another implementation method provided in this application is as follows: when the refrigerator is running stably, the rotatable liquid storage bag starts to work. When the refrigerator door is opened, the temperature sensor detects the temperature inside the shelf. If the temperature difference of the corresponding shelf is less than 0.5℃ in three collections, there are no items to be cooled. If the temperature difference is greater than 0.5℃ in three collections, the rotatable liquid storage bag works according to the control strategy. The internal refrigerant liquid level is above the corresponding heat pipe condensation section, and the heat pipe is activated to quickly cool down and stabilize the cabinet temperature.

[0017] 3. Beneficial effects

[0018] Compared with the prior art, the beneficial effects of the phase change material cold storage refrigerator and its control method provided in this application are as follows:

[0019] The phase change material cold storage refrigerator provided in this application achieves the purpose of improving temperature uniformity without occupying additional compartment volume.

[0020] The phase change material cold storage refrigerator provided in this application utilizes heat pipes and air cooling to rapidly cool the phase change material shelves with different phase change temperatures during refrigerator startup, so that they can provide different levels of cooling after the refrigerator stops, thereby achieving a high degree of temperature uniformity in the refrigerator compartments.

[0021] The phase change material cold storage refrigerator provided in this application can use a combination of heat pipes and air cooling to cool the phase change material during the start-up phase, thereby completing its cold storage during the start-up phase.

[0022] The phase change material cold storage refrigerator provided in this application can independently provide cooling capacity for the compartments or phase change materials, minimizing unnecessary energy consumption. Attached Figure Description

[0023] Figure 1 This is a schematic diagram of the phase change material cold storage refrigerator structure of this application;

[0024] Figure 2 This is a schematic diagram of the phase change material cold storage refrigerator of this application;

[0025] Figure 3 This is a schematic diagram of the connection between the rotatable liquid storage bag and the heat pipe in this application;

[0026] Figure 4 This is a schematic diagram of the fin structure of this application;

[0027] Figure 5 This is a schematic diagram of the control method flow of this application;

[0028] Figure 6 This is a schematic diagram of the control process for the rotatable liquid storage tank in this application;

[0029] Figure 7 This is a schematic diagram of the working process of the rotatable liquid storage bag of this application;

[0030] Figure 8 This is a second schematic diagram of the working process of the rotatable liquid storage bag of this application;

[0031] Figure 9 This is the third schematic diagram of the working process of the rotatable liquid storage bag of this application. Detailed Implementation

[0032] In the following, specific embodiments of this application will be described in detail with reference to the accompanying drawings. Based on these detailed descriptions, those skilled in the art will be able to clearly understand and implement this application. Without departing from the principles of this application, features from various embodiments can be combined to obtain new implementations, or certain features from some embodiments can be substituted to obtain other preferred implementations.

[0033] See Figures 1-9This application provides a phase change material (PCM) cold storage refrigerator, including a compartment. A foamed layer 2 is disposed outside the compartment, and an air duct is provided between the foamed layer 2 and the compartment. A shelf assembly is disposed inside the compartment, and the shelf assembly includes several shelves 3. Phase change material is disposed on the shelves 3, with each layer of phase change material having a different phase change temperature. A heat pipe 1 is disposed within the phase change material. One end of the heat pipe 1 is an evaporation section 102, and the other end is a condensation section 103. The phase change material is in contact with the evaporation section 102, and the condensation section 103... 03 is disposed within a rotatable liquid storage bag 6, which is disposed within the foaming layer 2. A temperature sensor is disposed inside the refrigerator and is connected to a controller. The rotatable liquid storage bag 6 is connected to the controller. A fan 5 and an evaporator 4 are disposed within the air duct. The evaporator 4 is connected to the rotatable liquid storage bag 6 or a compressor 7. The rotatable liquid storage bag 6 is connected to the compressor 7. The compressor 7, condenser 8, capillary tube 9 are sequentially connected to the evaporator 4. The rotatable liquid storage bag 6 is connected to a motor.

[0034] Shelves 3 for phase change materials with different phase change temperatures are arranged in the refrigerator compartment. Each shelf contains an evaporation section 102 and fins 101 of a heat pipe 1. The condensation section 103 of the heat pipe 1 is arranged inside a rotatable liquid storage bag 6, which is located inside a foaming layer 2. The refrigerator evaporator 4 and fan 5 are arranged in the evaporator duct. The compressor 7, condenser 8, and capillary tube 9 are not specially arranged.

[0035] When the refrigerator is turned on, fan 5 draws air through evaporator 4 and blows it into the compartment to cool the phase change material shelf 3. Through air cooling and heat pipe coupling heat transfer, the phase change material shelf 3 cools down rapidly when the refrigerator is turned on, achieving the purpose of rapid condensation of the phase change material. When the refrigerator is running stably, items to be refrigerated are placed inside. The internal temperature sensor (infrared thermometer) senses the load and transmits the relevant data to the controller. The controller processes the data, formulates and issues a rotation control strategy for the rotatable liquid storage tank 6, and the internal refrigerant liquid level is above the corresponding heat pipe condensation section 103, activating heat pipe 1 for rapid cooling and stabilizing the compartment temperature. When the refrigerator is turned off, natural air convection in the compartment will create a temperature distribution with a high temperature at the top and a low temperature at the bottom. From top to bottom, the phase change material shelf 3, with its phase change temperature and mass increasing sequentially, transfers cold energy to different heights in the compartment, greatly improving the temperature uniformity of the compartment, while the phase change material consumption rate tends to be uniform.

[0036] The phase change material cold storage refrigerator provided in this application uses shelves made of phase change materials with different phase change temperatures to cope with different temperature zones, ensuring temperature consistency in each zone.

[0037] The phase change material cold storage refrigerator provided in this application uses shelves with different masses of phase change material to cope with different temperature zones, ensuring that the consumption ratio of phase change material in each zone is consistent and avoiding waste of phase change material.

[0038] The phase change material cold storage refrigerator provided in this application uses a rotatable liquid storage bag to quickly and accurately cool a single heat pipe, stabilize the refrigerator temperature, reduce the frequency of refrigerator operation, and reduce energy consumption.

[0039] Furthermore, the shelf 3 is provided with fins 101, which are connected to the evaporation section 102. The evaporation section 102 of the heat pipe 1 increases the heat transfer area through the fins 101, thereby cooling the phase change material shelf 3.

[0040] Furthermore, the fins 101 are serrated. The serrated fins 101 are arranged to exchange heat fully with the phase change material shelf 3 to achieve faster cooling.

[0041] Furthermore, the shelf 3 has three layers, which divide the refrigerator into four parts. The average air temperature difference of each layer is b℃. After the refrigerator is stopped, the average air temperature of the four parts from top to bottom can be set as x, xb, x-2b and x-3b. That is, the phase change temperature of the phase change material in each layer is different. The mass ratio of the phase change material is calculated based on the different phase change temperatures.

[0042] The phase change temperature of the material increases by a℃ from top to bottom, which can be denoted as y, y+a, and y+2a. This improves the temperature distribution caused by natural convection after the refrigerator stops, resulting in a higher temperature at the top and a lower temperature at the bottom. The heat transfer coefficient and thermal conductivity of the phase change material are not significantly different from those of air. For the phase change material shelf 3, from top to bottom, according to the formula q = hΔT, the heat transfer can be expressed in terms of temperature difference. Considering only the latent heat storage of the phase change material, the mass ratio of each layer of phase change material from top to bottom should be: Because the refrigerator's temperature distribution is affected by natural convection after shutdown, resulting in a higher temperature at the top and a lower temperature at the bottom, the temperature difference between the phase change material and the air in the compartment increases sequentially from top to bottom. Conversely, the mass of phase change material used decreases proportionally from top to bottom, improving the consistency of phase change material consumption rate during startup. Here, x represents the average air temperature of the highest layer, ranging from 5 to 13℃; b represents the temperature difference between adjacent air layers, ranging from 1 to 3℃; y represents the relative temperature of the phase change material in the highest layer, ranging from 4 to 6℃; and a represents the temperature difference between adjacent phase change materials, ranging from 1 to 2℃.

[0043] like Figure 1 As shown in the example in this application, there is a 3-layer shelf 3. Of course, in actual use, the number of layers can be set as needed.

[0044] Furthermore, the rotatable liquid storage tank 6 is positioned higher than the shelf assembly. The refrigerant in the rotatable liquid storage tank 6 submerges the condenser section 103, and the refrigerant level is controlled by the motor. There are three condenser sections 103, and the directions of the three condenser sections 103 are upward 10301, horizontal 10302, and downward 10303, respectively.

[0045] The rotatable liquid storage tank 6 is positioned higher than the first-layer phase change material shelf 3. It contains a condensation section 103 with three heat pipes 1 arranged in three directions: upward 10301, horizontal 10302, and downward 10303. To ensure sufficient heat exchange in the condensation section, the rotatable liquid storage tank 6 must be sized such that the refrigerant liquid completely covers the condensation section 103 of the heat pipes. After stabilization, the liquid level is controlled by a motor next to the rotatable liquid storage tank 6 to adapt to newly added items and quickly stabilize the chamber temperature.

[0046] Furthermore, the heat pipe 1 inside the highest layer phase change material shelf 3 is driven by capillary force, while the heat pipes 1 inside the middle and lowest layer phase change material shelves 3 are driven by gravity. Because the height difference between the highest layer condensation section 103 and the evaporation section 102 is limited, and the phase change material has the least mass, capillary force is used for driving. The height difference between the middle and lowest layers is sufficient, and the evaporation sections 102 of the gravity-driven heat pipes 1 are evenly arranged inside the phase change material shelf 3.

[0047] Capillary force drive involves filling the insulating section (between the condensing section 103 and the evaporating section 102) of the heat pipe 1 with a wick made of porous material, such as wire mesh, grooves, sintered powder, fiber, or foamed metal, using capillary action to transport liquid from the condensing section to the evaporating section. In this application, capillary force coupled with gravity is used to provide power for the operation of the heat pipe, thereby solving the problem of insufficient operating power due to insufficient temperature difference between the evaporating section 102 and the condensing section 103 of the heat pipe 1.

[0048] Furthermore, the evaporator 4 is connected to the rotatable liquid receiver 6 or the compressor 7 via a three-way valve 10. The refrigerant from the refrigerator evaporator 4 is switched via the three-way valve 10 to flow to the inlet of the rotatable liquid receiver 6 or the compressor 7.

[0049] This application also provides a control method for the aforementioned phase change material (PCM) cold storage refrigerator. The method includes setting a maximum temperature Tr1 and a minimum temperature Tr2 for each compartment, and setting the phase change temperature of the first layer of PCM to Tp1. After the refrigerator is powered on, the temperature Tp of the PCM shelf interlayer and the refrigerator compartment temperature Tr are simultaneously monitored to determine the fan start / stop and the three-way valve control strategy. This control method achieves both cooling of the compartments and the PCM shelf while ensuring no additional power consumption.

[0050] Specifically, the refrigerator is set with the maximum temperature Tr1 and the minimum temperature Tr2 of the compartment, and the phase change temperature of the first-layer phase change material is Tp1. After the refrigerator is powered on, the temperature Tp in the sandwich layer of the phase change material shelf 3 and the temperature Tr in the refrigerating compartment are monitored simultaneously to determine the control strategies of the fan 5 and the three-way valve 11. When both Tp and Tr are greater than the set values Tp1 and Tr2, the refrigerator operates normally, the fan 5 is turned on, the inlet 11 of the three-way valve 10 is connected to the first outlet 13, and the refrigerant flows to the rotatable liquid storage package 6; when Tr is less than the set value Tr1 and Tp is greater than the set value Tp1, the fan 5 is turned off to avoid overcooling the air in the compartment and affecting the food quality, and the inlet 11 of the three-way valve 10 is connected to the first outlet 13, and the refrigerant flows to the rotatable liquid storage package 6; when Tr is greater than the set value Tr2 and Tp is less than the set value Tp1, the fan 5 is turned on to continue cooling the compartment, the three-way valve 10 is connected to the second outlet 12, and the refrigerant flows to the inlet of the compressor 7 to reduce the additional power consumption of the system; when both Tp and Tr are less than the set values Tp1 and Tr2, the refrigerator stops. By this control method, while taking into account the refrigeration of the compartment and the phase change material shelf 3, it is ensured that no additional power consumption is increased. The specific control method is as follows: S101: After the refrigerator is powered on, the temperature Tr in the compartment is monitored and compared with the refrigerator startup temperature Tr1: when Tr > Tr1, the refrigerator starts, the fan starts, the inlet 11 of the three-way valve 10 is connected to the second outlet 12, and step S102 is entered; when Tr < Tr1, it stops.

[0051] S102: Monitor the temperature Tr in the compartment and compare it with the refrigerator shutdown temperature Tr1: when Tr > Tr2, the fan starts; when Tr < Tr2, the fan stops. Enter step S103.

[0052] S103: Monitor the temperature Tp in the first-layer phase change material shelf of the compartment and compare it with its phase change temperature Tp1: when Tp > Tp1, the inlet 11 of the three-way valve 10 is connected to the second outlet 13; when Tp < Tp1, the inlet 11 of the three-way valve 10 is connected to the second outlet 12. Enter step S104.

[0053] S104: When Tr < Tr2 and Tp < Tp1, the refrigerator stops, otherwise enter S101.

[0054] Furthermore, when the refrigerator is running stably, after the refrigerator door is opened, the rotatable liquid storage package starts to work, and the temperature is collected by the infrared thermometer in the box to determine whether rapid cooling is required. When there are items to be cooled detected by the infrared thermometer in the box, the rotatable liquid storage package rotates according to the control strategy, and the liquid level of the internal refrigerant covers the corresponding heat pipe condensation section. The rotatable liquid storage package storing the refrigerant is used to start a single heat pipe for rapid and precise cooling, stabilize the box temperature, reduce the startup frequency of the refrigerator, and reduce the energy consumption.

[0055] Specifically, the control strategy for the rotatable liquid reservoir is as follows: When the refrigerator is running stably, the rotatable liquid reservoir starts working. When the refrigerator door is opened, an infrared thermometer checks the temperature inside each shelf every 15 seconds within one minute. If the temperature difference between the three temperature checks is less than 0.5℃, there are no items to be cooled. If the temperature difference is greater than 0.5℃, the rotatable liquid reservoir 6 operates according to the control strategy, and the internal refrigerant level rises above the corresponding heat pipe condensation section 103, activating heat pipe 1 for rapid cooling and stabilizing the refrigerator temperature. This control method achieves rapid temperature stabilization and saves energy. The specific control method is as follows:

[0056] S101: After the refrigerator is running stably, the rotatable liquid storage bag can be kept in its original position to detect whether the refrigerator door is open. When the refrigerator door is opened or closed, the infrared thermometer inside the refrigerator will detect whether there are items that need to be cooled.

[0057] S102: Detect whether the item to be cooled is on the first shelf: When the item to be cooled is on the first shelf, the liquid storage bag can be rotated 90°, and the liquid level inside will cover the upward, downward and horizontal condensation sections to quickly cool the items on the three shelves. After cooling is completed, proceed to step S105; when the item to be cooled is not on the first shelf, proceed to step S103.

[0058] S103: Detect whether the item to be cooled is on the second shelf: When the item to be cooled is on the second shelf, the liquid storage bag can be rotated 45°, the liquid level inside is above the downward and horizontally arranged condensation section, to quickly cool the items on the second and third shelves. After cooling is completed, proceed to step S105; when the item to be cooled is not on the second shelf, proceed to step S104.

[0059] S104: Detect whether the item to be cooled is on the third shelf: When the item to be cooled is on the third shelf, the liquid storage bag can be rotated 30°, the liquid level inside is above the downward-facing condensation section, to quickly cool the item on the third shelf. After cooling is completed, proceed to step S105; when the item to be cooled is not on the third shelf, proceed to step S105.

[0060] S105: Cooling is complete, the refrigerator is running stably, and the rotatable liquid storage tank is reset.

[0061] Although this application has been described above with reference to specific embodiments, those skilled in the art will understand that many modifications can be made to the configurations and details disclosed in this application within the principles and scope of the disclosure. The scope of protection of this application is determined by the appended claims, and the claims are intended to cover all modifications included in the literal meaning or scope of equivalents of the technical features in the claims.

Claims

1. A phase change material cold storage refrigerator, characterized in that: The refrigerator includes a compartment, an outer foam layer, and an air duct between the foam layer and the compartment. Inside the compartment is a shelving assembly comprising several shelves, each shelf containing a phase change material (PCM). Each PCM layer has a different PCM temperature. A heat pipe is embedded within the PCM, with one end serving as an evaporation section and the other as a condensation section. The PCM is in contact with the evaporation section. The condensation section is housed within a rotatable liquid storage tank, which is located within the foam layer. A temperature sensor is installed inside the refrigerator and connected to a controller. The rotatable liquid storage tank is also connected to the controller. A fan and an evaporator are located within the air duct. The evaporator is connected to either the rotatable liquid storage tank or a compressor. The rotatable liquid storage tank is connected to the compressor. The compressor, condenser, and capillary tube are sequentially connected to the evaporator. The rotatable liquid storage tank is connected to a motor. The refrigerant in the rotatable liquid storage tank is submerged above the condensation section, and the liquid level of the refrigerant is controlled by the motor; there are three condensation sections, and the directions of the three condensation sections are upward, horizontal and downward, respectively.

2. The phase change material cold storage refrigerator as described in claim 1, characterized in that: The shelf is equipped with fins, which are connected to the evaporation section.

3. The phase change material cold storage refrigerator as described in claim 2, characterized in that: The fins are serrated.

4. The phase change material cold storage refrigerator as described in claim 2, characterized in that: The shelf has three layers, which divide the refrigerator into four parts. The average air temperature difference between each layer is b℃. After the refrigerator is turned off, the average air temperature of the four parts from top to bottom is x, xb, x-2b, and x-3b. The phase change material of each layer has a different phase change temperature, and the mass ratio of the phase change material is calculated based on the different phase change temperatures.

5. The phase change material cold storage refrigerator as described in claim 4, characterized in that: The rotatable liquid storage bag is positioned higher than the shelf assembly.

6. The phase change material cold storage refrigerator as described in claim 5, characterized in that: The heat pipes in the first layer are driven by capillary force, the heat pipes in the second layer are driven by gravity, and the heat pipes in the third layer are driven by gravity.

7. The phase change material cold storage refrigerator as described in any one of claims 1 to 6, characterized in that: The evaporator is connected to the rotatable liquid reservoir or the compressor via a three-way valve.

8. A control method for a phase change material cold storage refrigerator according to any one of claims 1 to 6, characterized in that: The method includes setting a maximum temperature Tr1 and a minimum temperature Tr2 for each compartment of the refrigerator, with the phase change temperature of the first layer of phase change material set to Tp1. After the refrigerator is powered on, the temperature Tp of the phase change material shelf interlayer and the temperature Tr of the refrigerator compartment are monitored simultaneously to determine the connection strategy between the fan and evaporator and the rotatable liquid storage tank or the compressor. When both Tp and Tr are greater than the set values ​​Tp1 and Tr2, the refrigerator operates normally, the fan is turned on, and the refrigerant flows to the rotatable liquid storage tank. When Tr is less than the set value Tr1, and Tp is greater than the set value Tp1, the fan is turned off to prevent the air in the compartment from becoming too cold and affecting food quality, and the refrigerant flows to the rotatable liquid storage tank. When Tr is greater than the set value Tr2, and Tp is less than the set value Tp1, the fan is turned on to continue cooling the compartment, and the refrigerant flows to the compressor inlet to reduce the system's additional power consumption. When both Tp and Tr are less than the set values ​​Tp1 and Tr2, the refrigerator stops.

9. The phase change material cold storage refrigerator as described in claim 8, characterized in that: When the refrigerator is running stably, the rotatable liquid storage tank starts working. When the refrigerator door is opened, the temperature sensor detects the temperature inside the shelf. If the temperature difference between the three corresponding shelf measurements is less than 0.5℃, there are no items to be cooled. If the temperature difference between the three measurements is greater than 0.5℃, the rotatable liquid storage tank works according to the control strategy, and the internal refrigerant liquid level is above the corresponding heat pipe condensation section, activating the heat pipe for rapid cooling and stabilizing the refrigerator temperature.

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