Control method of a refrigeration appliance and refrigeration appliance

Abstract

This invention discloses a control method for a refrigeration device and the refrigeration device itself. The method includes the following steps: controlling the compressor's operating rate between a preset first operating rate threshold and a preset second operating rate threshold; opening the refrigeration electronic expansion valve; determining whether the return gas temperature is between a preset first refrigeration temperature threshold and a preset second refrigeration temperature threshold; otherwise, if the return gas temperature is less than the first refrigeration temperature threshold, controlling the opening of the refrigeration electronic expansion valve to decrease; if the return gas temperature is greater than the second refrigeration temperature threshold, controlling the opening of the refrigeration electronic expansion valve to increase; and returning to the point where the compressor's operating rate is controlled between the preset first operating rate threshold and the preset second operating rate threshold. This control method ensures that both the operating rate and the return gas temperature are within preset ranges, resulting in the most energy-efficient compressor speed and refrigeration electronic expansion valve opening during refrigeration, thus meeting refrigeration requirements while making the refrigeration device more energy-efficient.

Description

Technical Field

[0001] This invention relates to refrigeration equipment, and particularly to a control method for refrigeration equipment and refrigeration equipment. Background Technology

[0002] Against the backdrop of energy conservation and emission reduction, how to further reduce the power consumption of refrigeration equipment such as refrigerators and freezers has always been a challenge for the industry. Existing refrigeration systems consist of parallel refrigeration evaporators and freezing evaporators, with each evaporator equipped with a capillary tube. An electric valve switches the refrigerant between the refrigeration and freezing evaporators. However, the capillary tube cannot actively regulate the refrigerant flow; the refrigerant flow mainly changes with the compressor speed. Furthermore, the refrigerant flow is affected by ambient temperature and the heat load of the refrigeration equipment, resulting in either excessively high compressor speed leading to high power consumption or excessively low speed resulting in poor cooling performance. Summary of the Invention

[0003] The purpose of this invention is to provide a control method and a refrigeration device for refrigeration equipment, so as to make the refrigeration equipment more energy-efficient while meeting refrigeration needs.

[0004] To achieve one of the above-mentioned objectives, one embodiment of the present invention provides a control method for a refrigeration device, comprising the following steps:

[0005] The compressor's operating rate is controlled between a preset first operating rate threshold and a second operating rate threshold, wherein the second operating rate threshold is greater than the first operating rate threshold.

[0006] Open the refrigeration electronic expansion valve between the refrigeration evaporator and the compressor;

[0007] Determine whether the return air temperature is between a preset first refrigeration temperature threshold and a preset second refrigeration temperature threshold, wherein the second refrigeration temperature threshold is greater than the first refrigeration temperature threshold;

[0008] If so, the refrigeration electronic expansion valve between the refrigeration evaporator and the compressor is opened; wherein, the first branch formed by the refrigeration electronic expansion valve and the refrigeration evaporator connected in series is connected in parallel with the second branch formed by the refrigeration electronic expansion valve and the refrigeration evaporator connected in series;

[0009] Otherwise, when the return air temperature is less than the first refrigeration temperature threshold, the opening of the refrigeration electronic expansion valve is controlled to decrease, and when the return air temperature is greater than the second refrigeration temperature threshold, the opening of the refrigeration electronic expansion valve is controlled to increase; the compressor's operating rate is then controlled to be between the preset first operating rate threshold and the second operating rate threshold.

[0010] As a further improvement to one embodiment of the present invention, the step of "controlling the compressor's operating rate between a preset first operating rate threshold and a second operating rate threshold; opening the refrigeration electronic expansion valve between the refrigeration evaporator and the compressor" specifically means:

[0011] Determine whether the compressor's operating rate is greater than or equal to the first operating rate threshold and less than the second operating rate threshold;

[0012] If so, execute the command "Open the refrigeration electronic expansion valve between the refrigeration evaporator and the compressor";

[0013] Otherwise, adjust the compressor speed to adjust the operating rate, and return to the step of "determining whether the compressor operating rate is greater than or equal to the first operating rate threshold and less than the second operating rate threshold".

[0014] As a further improvement to one embodiment of the present invention, the "adjusting the operating rate by adjusting the compressor speed" specifically means:

[0015] If the compressor's operating rate is less than a first operating rate threshold, then the compressor speed is controlled to decrease.

[0016] If the compressor's operating rate is greater than or equal to the second operating rate threshold, then the compressor speed is controlled to increase.

[0017] As a further improvement of one embodiment of the present invention, the first start-up rate threshold is 90%, the second start-up rate threshold is 100%, the compressor speed decreases by 50 rpm in the "control compressor speed decrease" and the compressor speed increases by 50 rpm in the "control compressor speed increase".

[0018] As a further improvement of one embodiment of the present invention, the first refrigeration temperature threshold is lower than the ambient temperature, and the second refrigeration temperature threshold is higher than the ambient temperature.

[0019] As a further improvement of one embodiment of the present invention, the difference between the ambient temperature and the first refrigeration temperature threshold is 2°C, and the difference between the second refrigeration temperature threshold and the ambient temperature is 1°C.

[0020] As a further improvement of one embodiment of the present invention, the opening degree of the refrigeration electronic expansion valve decreases by 20% in the "controlling the opening degree of the refrigeration electronic expansion valve to decrease", and the opening degree of the refrigeration electronic expansion valve increases by 20% in the "controlling the opening degree of the refrigeration electronic expansion valve to increase".

[0021] As a further improvement to one embodiment of the present invention, after the step of "opening the electronic expansion valve for refrigeration between the evaporator and the compressor", the following is also included:

[0022] Determine whether the return gas temperature is between a preset first freezing temperature threshold and a second freezing temperature threshold, wherein the second freezing temperature threshold is greater than the first freezing temperature threshold;

[0023] This maintains the compressor's operating rate and the opening degree of the refrigeration electronic expansion valve and the freezing electronic expansion valve;

[0024] Otherwise, when the return gas temperature is less than the first freezing temperature threshold, the opening of the refrigeration electronic expansion valve is controlled to decrease, and when the return gas temperature is greater than the second freezing temperature threshold, the opening of the refrigeration electronic expansion valve is controlled to increase; the compressor's operating rate is then controlled to be between the preset first operating rate threshold and the second operating rate threshold.

[0025] As a further improvement of one embodiment of the present invention, the first freezing temperature threshold is less than the ambient temperature, the second freezing temperature threshold is greater than the ambient temperature, and the difference between the ambient temperature and the first freezing temperature threshold is 2°C, and the difference between the second freezing temperature threshold and the ambient temperature is 1°C.

[0026] As a further improvement of one embodiment of the present invention, the opening degree of the refrigeration electronic expansion valve decreases by 20% in the "controlling the opening degree of the refrigeration electronic expansion valve to decrease", and the opening degree of the refrigeration electronic expansion valve increases by 20% in the "controlling the opening degree of the refrigeration electronic expansion valve to increase".

[0027] To achieve one of the above-mentioned objectives, one embodiment of the present invention provides a refrigeration device, including a refrigeration system and a control system. The refrigeration system includes a compressor, a condenser connected to the outlet of the compressor, and a first branch and a second branch connected in parallel between the condenser and the return port of the compressor. The first branch includes a refrigeration electronic expansion valve connected to the condenser and a refrigeration evaporator connected to the return port of the compressor. The second branch includes a freezing electronic expansion valve connected to the condenser and a freezing evaporator connected to the return port of the compressor.

[0028] The control system includes a memory and a processor. The memory stores a computer program that can run on the processor. When the processor executes the program, it implements the control method of the refrigeration equipment described in the above embodiments.

[0029] As a further improvement of one embodiment of the present invention, both the refrigeration evaporator and the freezing evaporator are connected to the return port of the compressor through a return gas pipe. The refrigeration system also includes a heat exchange pipe located between the condenser and the first branch and the second branch, and the return gas pipe is in contact with the surface of the heat exchange pipe.

[0030] Compared with the prior art, the beneficial effects of the present invention are as follows: the control method of the refrigeration equipment of the present invention can make the operating rate and return gas temperature within a preset range. At this time, the compressor speed and the opening degree of the refrigeration electronic expansion valve of the refrigeration equipment are obtained at the most energy-saving time during refrigeration, so as to make the refrigeration equipment more energy-efficient while meeting the refrigeration demand. Attached Figure Description

[0031] Figure 1 This is a schematic diagram of the structure of a refrigeration system according to an embodiment of the present invention;

[0032] Figure 2 This is a flowchart of a control method for a refrigeration device according to an embodiment of the present invention;

[0033] Among them, 10 is the compressor; 20 is the condenser; 30 is the heat exchanger; 40 is the refrigeration electronic expansion valve; 50 is the refrigeration evaporator; 60 is the refrigeration electronic expansion valve; 70 is the refrigeration evaporator; and 80 is the return gas pipe. Detailed Implementation

[0034] The present invention will now be described in detail with reference to the specific embodiments shown in the accompanying drawings. However, these embodiments do not limit the present invention, and any structural, methodological, or functional modifications made by those skilled in the art based on these embodiments are included within the scope of protection of the present invention.

[0035] In the various illustrations of this invention, for ease of illustration, certain dimensions of structures or parts may be enlarged relative to other structures or parts; therefore, only the basic structure of the subject matter of this invention is used to illustrate the invention.

[0036] One embodiment of the present invention provides a control method for a refrigeration device and a refrigeration device.

[0037] The refrigeration equipment refers to refrigerators, wine cabinets, and other devices used for refrigerating and freezing items.

[0038] The refrigeration equipment includes a housing, a door, a refrigeration system, and a control system. (The housing, door, and control system are not shown in the diagram.)

[0039] The cabinet is equipped with a refrigerator compartment and a freezer compartment, and the door is installed on the cabinet to open or close the refrigerator compartment and the freezer compartment.

[0040] like Figure 1As shown, the refrigeration system includes a compressor 10, a condenser 20 connected to the outlet of the compressor 10, and a first branch and a second branch connected in parallel between the condenser 20 and the return port of the compressor 10. The first branch includes a refrigeration electronic expansion valve 40 connected to the condenser 20 and a refrigeration evaporator 50 connected to the return port of the compressor 10. The second branch includes a freezing electronic expansion valve 60 connected to the condenser 20 and a freezing evaporator 70 connected to the return port of the compressor 10.

[0041] The refrigeration evaporator 50 is used to cool the refrigeration compartment, and the freezing evaporator 70 is used to cool the freezing compartment.

[0042] Specifically, the working process of the refrigeration system is as follows: When the refrigeration equipment needs to be refrigerated, the refrigeration electronic expansion valve 40 opens and the freezing electronic expansion valve 60 closes. After the compressor 10 starts, the liquid refrigerant absorbs heat in the refrigeration evaporator 50 and vaporizes into low-temperature, low-pressure steam. Then, it is drawn into the compressor 10 and compressed into high-pressure, high-temperature steam before being discharged into the condenser 20. After releasing heat in the condenser 20, it condenses into high-pressure liquid, which is then throttled by the refrigeration electronic expansion valve 40 into low-pressure, low-temperature refrigerant. It then re-enters the refrigeration evaporator 50 to absorb heat and vaporize, thus achieving the purpose of cyclic refrigeration. When the refrigeration equipment needs to freeze, the refrigeration electronic expansion valve 60 opens, and the refrigeration electronic expansion valve 40 closes. After the compressor 10 starts, the liquid refrigerant absorbs heat in the refrigeration evaporator 70 and vaporizes into low-temperature, low-pressure vapor. This vapor is then drawn into the compressor 10 and compressed into high-pressure, high-temperature vapor before being discharged into the condenser 20. In the condenser 20, it releases heat and condenses into a high-pressure liquid. This liquid is then throttled by the refrigeration electronic expansion valve 60 into low-pressure, low-temperature refrigerant, which then re-enters the refrigeration evaporator 70 to absorb heat and vaporize, achieving a cyclic refrigeration process. Of course, the refrigeration electronic expansion valve 60 and the refrigeration electronic expansion valve 40 can be opened simultaneously, allowing freezing and refrigeration to occur concurrently.

[0043] The refrigeration electronic expansion valve 40 is installed on the refrigeration evaporator 50, and the freezing electronic expansion valve 60 is installed on the freezing evaporator 70.

[0044] The control system includes a memory and a processor. The memory stores a computer program that can run on the processor. When the processor executes the program, it implements the control method for the refrigeration equipment.

[0045] Furthermore, both the refrigerated evaporator 50 and the frozen evaporator 70 are connected to the return port of the compressor 10 via a return pipe 80. The refrigeration system also includes a heat exchange tube located between the condenser 20 and the first and second branches. The return pipe 80 is in contact with the surface of the heat exchange tube, thereby enabling heat exchange between the return pipe 80 and the heat exchange tube, which lowers the temperature of the refrigerant before throttling, achieving the purpose of subcooling.

[0046] The electronic expansion valve can be completely closed. Compared to existing refrigeration systems that combine capillary tubes with electric valves, the refrigeration system in this embodiment does not require an electric valve to switch the refrigerant flow path. The refrigeration and freezing electronic expansion valves can also be switched on and off and their opening degrees adjusted to achieve functions such as separate refrigeration and freezing, or simultaneous refrigeration and freezing. This design not only regulates refrigerant flow and controls flow on / off, but also enhances heat exchange and ensures a proper match between refrigerant flow and compressor speed, resulting in minimal refrigerator power consumption.

[0047] First, it should be noted that the lower the compressor speed, the lower the average power, the higher the compressor operating rate, the smaller the temperature difference inside the casing, the less heat exchange loss in the evaporator and inside the casing, and the lower the power consumption. Therefore, when adjusting the compressor speed, the principle is that the higher the operating rate, the better.

[0048] like Figure 2 As shown, the control method for the refrigeration equipment includes the following steps:

[0049] S1. Control the compressor 10 to operate between a preset first operating rate threshold and a second operating rate threshold, wherein the second operating rate threshold is greater than the first operating rate threshold.

[0050] By using S1, the operating rate of compressor 10 is kept within a reasonable range, avoiding excessive power consumption due to a low operating rate of compressor 10, and also avoiding excessive operating time of compressor 10 due to a high operating rate, which would reduce its lifespan.

[0051] S2. Open the refrigeration electronic expansion valve 40 between the refrigeration evaporator 50 and the compressor 10.

[0052] S2 initiates the refrigeration operation of the refrigeration equipment.

[0053] S3. Determine whether the return air temperature is between the preset first refrigeration temperature threshold and the second refrigeration temperature threshold, wherein the second refrigeration temperature threshold is greater than the first refrigeration temperature threshold.

[0054] The result of S3 is yes, indicating that the return gas temperature is suitable. Therefore:

[0055] S4. Open the refrigeration electronic expansion valve 60 between the refrigeration evaporator 70 and the compressor 10; wherein, the first branch formed by the refrigeration electronic expansion valve 40 and the refrigeration evaporator 50 connected in series is connected in parallel with the second branch formed by the refrigeration electronic expansion valve 60 and the refrigeration evaporator 70 connected in series.

[0056] If the result of S3 is negative, it indicates that the return gas temperature is not suitable.

[0057] S5. When the return air temperature is less than the first refrigeration temperature threshold, control the opening of the refrigeration electronic expansion valve 40 to decrease; when the return air temperature is greater than the second refrigeration temperature threshold, control the opening of the refrigeration electronic expansion valve 40 to increase. Then return to "S1. Control the compressor 10's operating rate between the preset first operating rate threshold and the second operating rate threshold".

[0058] If the return gas temperature is lower than the first refrigeration temperature threshold, it indicates that the refrigerant flow is too high, resulting in a low return gas temperature and wasted cooling capacity. In this case, the opening of the refrigeration electronic expansion valve 40 needs to be reduced to decrease the flow rate. If the return gas temperature is higher than the second refrigeration temperature threshold, it indicates that the refrigerant flow is insufficient, causing the refrigerant to overheat at the evaporator outlet and resulting in wasted work by the compressor 10. In this case, the opening of the refrigeration electronic expansion valve 40 needs to be increased. However, after adjusting the opening, the operating rate of the compressor 10 will also change. It is necessary to return to the first step to bring the operating rate back to between the first and second operating rate thresholds. The specific adjustment method is to adjust the speed of the compressor 10 and then re-determine whether the return gas temperature is between the first and second refrigeration temperature thresholds. Repeat the cycle until both the operating rate and the return gas temperature are within the preset range. At this point, the most energy-efficient compressor 10 speed and refrigeration electronic expansion valve 40 opening are obtained for refrigeration, which satisfies the refrigeration demand while making the refrigeration equipment more energy-efficient.

[0059] The calculation method for the power-on rate is a conventional technique in this field, and will not be elaborated upon in this invention.

[0060] Furthermore, the steps "S1, controlling the operating rate of compressor 10 between a preset first operating rate threshold and a second operating rate threshold; S2, opening the refrigeration electronic expansion valve 40 between the refrigeration evaporator 50 and compressor 10" specifically refer to:

[0061] S101. Determine whether the operating rate of compressor 10 is greater than or equal to the first operating rate threshold and less than the second operating rate threshold.

[0062] If the result of S101 is yes, then execute "S2, open the refrigeration electronic expansion valve 40 between the refrigeration evaporator 50 and the compressor 10";

[0063] The result of S101 is otherwise: S102, adjust the operating rate by adjusting the speed of compressor 10, and return to execute "S101, determine whether the operating rate of compressor 10 is greater than or equal to the first operating rate threshold and less than the second operating rate threshold".

[0064] Furthermore, "S102, adjusting the operating rate by adjusting the compressor speed" specifically means:

[0065] If the operating rate of the compressor 10 is less than the first operating rate threshold, the speed of the compressor 10 is controlled to decrease, thereby increasing the operating rate of the compressor 10.

[0066] If the operating rate of the compressor 10 is greater than or equal to the second operating rate threshold, the speed of the compressor 10 is controlled to increase, thereby reducing the operating rate of the compressor 10.

[0067] Furthermore, the first start-up rate threshold is 90%, the second start-up rate threshold is 100%, the compressor 10 speed decreases by 50 rpm in the "control compressor 10 speed decrease" and the compressor 10 speed increases by 50 rpm in the "control compressor 10 speed increase".

[0068] Therefore, in summary, the specific steps of "S1. Controlling the operating rate of compressor 10 between a preset first operating rate threshold and a second operating rate threshold; S2. Opening the refrigeration electronic expansion valve 40 between the refrigeration evaporator 50 and compressor 10" are as follows:

[0069] S111. Determine whether the operating rate of compressor 10 is greater than or equal to 90% and less than 100%.

[0070] If the result of S111 is yes, then execute "S2, open the refrigeration electronic expansion valve 40 between the refrigeration evaporator 50 and the compressor 10".

[0071] The result of S111 is otherwise: S112, determine whether the operating rate of compressor 10 is less than 90%.

[0072] If the result of S112 is yes, then S113, control the compressor 10 speed to decrease by 50 rpm.

[0073] The result of S112 is otherwise: S114, control the compressor speed to increase by 50 rpm.

[0074] After S113 and S114 are completed, return to the statement "Determine whether the operating rate of compressor 10 is greater than or equal to 90% and less than 100%".

[0075] Furthermore, the first refrigeration temperature threshold is lower than the ambient temperature, and the second refrigeration temperature threshold is higher than the ambient temperature. That is, the appropriateness of the opening degree of the refrigeration electronic expansion valve 40 is determined by the ambient temperature, and the most energy-efficient compressor speed 10 and the opening degree of the refrigeration electronic expansion valve 40 are matched under different ambient temperatures, so that the refrigeration equipment is in the most energy-efficient operating state regardless of the ambient temperature.

[0076] Specifically, the difference between the ambient temperature and the first refrigeration temperature threshold is 2°C to avoid excessively low return air temperature. Excessively low return air temperature indicates excessive flow, excess cooling capacity, and insufficient heat exchange in the return pipe 80, resulting in wasted cooling capacity flowing back to the compressor 10. It also leads to failure of the anti-condensation test, with condensation occurring in the return pipe 80.

[0077] The difference between the second refrigeration temperature threshold and the ambient temperature is 1°C to avoid excessively high return temperature. Excessively high return temperature indicates insufficient refrigerant, leading to overheating of the evaporator outlet and increased condensation temperature, thus increasing power consumption.

[0078] Specifically, S5 is:

[0079] S501. Determine whether the return air temperature is less than the first refrigeration temperature threshold.

[0080] If the result of S501 is yes, then S502 controls the opening degree of the refrigeration electronic expansion valve 40 to decrease.

[0081] If the result of S501 is negative, it indicates that the return air temperature is greater than the second refrigeration temperature threshold. Then, S503 controls the opening degree of the refrigeration electronic expansion valve 40 to increase.

[0082] After S502 or S503 is completed, return to S1 to readjust the operating rate of compressor 10.

[0083] Specifically, in the phrase "controlling the opening of the refrigeration electronic expansion valve 40 to decrease", the opening of the refrigeration electronic expansion valve 40 decreases by 20%, and in the phrase "controlling the opening of the refrigeration electronic expansion valve 40 to increase", the opening of the refrigeration electronic expansion valve 40 increases by 20%.

[0084] If the ambient temperature change is detected to exceed a certain range, the above steps will be restarted.

[0085] Furthermore, after step S4, opening the electronic expansion valve 60 between the refrigeration evaporator 70 and the compressor 10, the following is also included:

[0086] S6. Determine whether the return gas temperature is between a preset first freezing temperature threshold and a second freezing temperature threshold, wherein the second freezing temperature threshold is greater than the first freezing temperature threshold.

[0087] If the result of S6 is yes, then S7 maintains the operating rate of the compressor 10 and the opening degree of the refrigeration electronic expansion valve 40 and the freezing electronic expansion valve 60.

[0088] If the result of S6 is negative, it indicates that the return gas temperature is not suitable. Then, in S8, when the return gas temperature is less than the first freezing temperature threshold, the opening of the freezing electronic expansion valve 60 is controlled to decrease, and when the return gas temperature is greater than the second freezing temperature threshold, the opening of the freezing electronic expansion valve 60 is controlled to increase.

[0089] Return to "S1, control the compressor 10's operating rate between the preset first operating rate threshold and the second operating rate threshold".

[0090] If the return gas temperature is lower than the first freezing temperature threshold, it indicates that the refrigerant flow is too large, resulting in a low return gas temperature and wasted cooling capacity. In this case, the opening of the refrigeration electronic expansion valve 60 needs to be reduced to decrease the flow rate. If the return gas temperature is higher than the second freezing temperature threshold, it indicates that the refrigerant flow is insufficient, causing the refrigerant to overheat at the evaporator outlet and resulting in wasted work by the compressor 10. In this case, the opening of the refrigeration electronic expansion valve 60 needs to be increased. However, after adjusting the opening, the operating rate of the compressor 10 will also change. It is necessary to return to the first step to bring the operating rate back to between the first and second operating rate thresholds. The specific adjustment method is to adjust the speed of the compressor 10 and then re-determine whether the return gas temperature is between the first and second refrigeration temperature thresholds, and whether it is between the first and second freezing temperature thresholds. The cycle is repeated until the operating rate and return gas temperature are both within the preset range. At this point, the most energy-efficient compressor speed (10), refrigeration electronic expansion valve opening (40), and refrigeration electronic expansion valve opening (60) are obtained for both refrigeration and freezing. Then, the compressor speed (10), refrigeration electronic expansion valve opening (40), and refrigeration electronic expansion valve opening (60) are maintained to make the refrigeration equipment more energy-efficient while meeting the refrigeration and freezing requirements.

[0091] Furthermore, the first freezing temperature threshold is lower than the ambient temperature, and the second freezing temperature threshold is higher than the ambient temperature. That is, the appropriateness of the opening degree of the refrigeration electronic expansion valve 60 is determined by the ambient temperature, and the most energy-efficient compressor speed 10 and the opening degree of the refrigeration electronic expansion valve 60 are matched under different ambient temperatures, so that the refrigeration equipment is in the most energy-efficient operating state regardless of the ambient temperature.

[0092] Furthermore, the difference between the ambient temperature and the first freezing temperature threshold is 2°C. This is to avoid excessively low return air temperature. Excessively low return air temperature indicates excessive flow, excess cooling capacity, and insufficient heat exchange in the return pipe 80, resulting in wasted cooling capacity flowing back to the compressor 10. It also leads to failure of the anti-condensation test, with condensation occurring in the return pipe 80.

[0093] The difference between the second freezing temperature threshold and the ambient temperature is 1°C to prevent excessively high return temperature. Excessively high return temperature indicates insufficient refrigerant, leading to overheating of the evaporator outlet and increased condensation temperature, thus increasing power consumption.

[0094] Specifically, S8 is:

[0095] S801. Determine whether the return gas temperature is less than the first freezing temperature threshold.

[0096] If the result of S801 is yes, then S802 controls the opening degree of the refrigeration electronic expansion valve 60 to decrease;

[0097] If the result of S801 is negative, it indicates that the return gas temperature is greater than the second freezing temperature threshold. Then, in S803, the opening degree of the electronic expansion valve 60 is increased.

[0098] After S502 or S503 is completed, return to S1 to readjust the operating rate of compressor 10.

[0099] In the phrase "controlling the opening degree of the refrigeration electronic expansion valve 60 to decrease", the opening degree of the refrigeration electronic expansion valve 60 decreases by 20%; in the phrase "controlling the opening degree of the refrigeration electronic expansion valve 60 to increase", the opening degree of the refrigeration electronic expansion valve 60 increases by 20%.

[0100] If the ambient temperature change is detected to exceed a certain range, the above steps will be restarted.

[0101] The control method for the refrigeration equipment is activated after the refrigeration equipment has been running stably. Specifically, it is not activated immediately after the equipment has been turned on for a period of time, but rather after the equipment has stabilized. For example, the temperature variation in the refrigerator and freezer compartments is within 5°C over an hourly period. The return gas temperature is detected by a temperature sensor located at the return gas inlet of the compressor 10 and the return gas pipe 80.

[0102] The detailed descriptions listed above are merely specific descriptions of feasible embodiments of the present invention, and are not intended to limit the scope of protection of the present invention. All equivalent embodiments or modifications made without departing from the spirit of the present invention should be included within the scope of protection of the present invention.

Claims

1. A control method for a refrigeration device, characterized in that, Includes the following steps: The compressor's operating rate is controlled to be between a preset first operating rate threshold and a second operating rate threshold, wherein the second operating rate threshold is greater than the first operating rate threshold. Open the refrigeration electronic expansion valve between the refrigeration evaporator and the compressor; Determine whether the return air temperature is between a preset first refrigeration temperature threshold and a preset second refrigeration temperature threshold, wherein the second refrigeration temperature threshold is greater than the first refrigeration temperature threshold; If so, the refrigeration electronic expansion valve between the refrigeration evaporator and the compressor is opened; wherein, the first branch formed by the refrigeration electronic expansion valve and the refrigeration evaporator connected in series is connected in parallel with the second branch formed by the refrigeration electronic expansion valve and the refrigeration evaporator connected in series; Otherwise, when the return air temperature is less than the first refrigeration temperature threshold, the opening of the refrigeration electronic expansion valve is controlled to decrease, and when the return air temperature is greater than the second refrigeration temperature threshold, the opening of the refrigeration electronic expansion valve is controlled to increase; the compressor's operating rate is then controlled to be between the preset first operating rate threshold and the second operating rate threshold.

2. The control method for the refrigeration equipment according to claim 1, characterized in that, The phrase "controlling the compressor's operating rate between a preset first operating rate threshold and a second operating rate threshold; opening the refrigeration electronic expansion valve between the refrigeration evaporator and the compressor" specifically refers to: Determine whether the compressor's operating rate is greater than or equal to the first operating rate threshold and less than the second operating rate threshold; If so, execute the command "Open the refrigeration electronic expansion valve between the refrigeration evaporator and the compressor"; Otherwise, adjust the compressor speed to adjust the operating rate, and return to the step of "determining whether the compressor operating rate is greater than or equal to the first operating rate threshold and less than the second operating rate threshold".

3. The control method for the refrigeration equipment according to claim 2, characterized in that, The phrase "adjusting the operating rate by adjusting the compressor speed" specifically refers to: If the compressor's operating rate is less than a first operating rate threshold, then the compressor speed is controlled to decrease. If the compressor's operating rate is greater than or equal to the second operating rate threshold, then the compressor speed is controlled to increase.

4. The control method for the refrigeration equipment according to claim 3, characterized in that, The first start-up rate threshold is 90%, the second start-up rate threshold is 100%, the compressor speed decreases by 50 rpm in "controlling the compressor speed to decrease", and the compressor speed increases by 50 rpm in "controlling the compressor speed to increase".

5. The control method for the refrigeration equipment according to claim 1, characterized in that, The first refrigeration temperature threshold is lower than the ambient temperature, and the second refrigeration temperature threshold is higher than the ambient temperature.

6. The control method for the refrigeration equipment according to claim 5, characterized in that, The difference between the ambient temperature and the first refrigeration temperature threshold is 2°C, and the difference between the second refrigeration temperature threshold and the ambient temperature is 1°C.

7. The control method for the refrigeration equipment according to claim 1, characterized in that, The "controlling the opening degree of the refrigeration electronic expansion valve to decrease" means that the opening degree of the refrigeration electronic expansion valve decreases by 20%, and the "controlling the opening degree of the refrigeration electronic expansion valve to increase" means that the opening degree of the refrigeration electronic expansion valve increases by 20%.

8. The control method for the refrigeration equipment according to claim 1, characterized in that, Following the statement "opening the electronic expansion valve for refrigeration between the evaporator and the compressor", the following is also included: Determine whether the return gas temperature is between a preset first freezing temperature threshold and a second freezing temperature threshold, wherein the second freezing temperature threshold is greater than the first freezing temperature threshold; This maintains the compressor's operating rate and the opening degree of the refrigeration electronic expansion valve and the freezing electronic expansion valve; Otherwise, when the return gas temperature is less than the first freezing temperature threshold, the opening of the refrigeration electronic expansion valve is controlled to decrease, and when the return gas temperature is greater than the second freezing temperature threshold, the opening of the refrigeration electronic expansion valve is controlled to increase; the compressor's operating rate is then controlled to be between the preset first operating rate threshold and the second operating rate threshold.

9. The control method for the refrigeration equipment according to claim 8, characterized in that, The first freezing temperature threshold is lower than the ambient temperature, the second freezing temperature threshold is higher than the ambient temperature, and the difference between the ambient temperature and the first freezing temperature threshold is 2°C, and the difference between the second freezing temperature threshold and the ambient temperature is 1°C.

10. The control method for the refrigeration equipment according to claim 8, characterized in that, The "controlling the opening degree of the refrigeration electronic expansion valve to decrease" means that the opening degree of the refrigeration electronic expansion valve decreases by 20%, and the "controlling the opening degree of the refrigeration electronic expansion valve to increase" means that the opening degree of the refrigeration electronic expansion valve increases by 20%.

11. A refrigeration device, characterized in that, The system includes a refrigeration system and a control system. The refrigeration system includes a compressor, a condenser connected to the outlet of the compressor, and a first branch and a second branch connected in parallel between the condenser and the return port of the compressor. The first branch includes a refrigeration electronic expansion valve connected to the condenser and a refrigeration evaporator connected to the return port of the compressor. The second branch includes a freezing electronic expansion valve connected to the condenser and a freezing evaporator connected to the return port of the compressor. The control system includes a memory and a processor. The memory stores a computer program that can run on the processor. When the processor executes the program, it implements the control method for the refrigeration equipment as described in any one of claims 1-10.

12. The refrigeration equipment according to claim 11, characterized in that, Both the refrigeration evaporator and the freezing evaporator are connected to the return port of the compressor via return pipes. The refrigeration system also includes a heat exchange tube located between the condenser and the first and second branches, with the return pipe in contact with the surface of the heat exchange tube.

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