Refrigeration unit control system, method, cold storage and readable storage medium

Abstract

This invention proposes a refrigeration unit control system, method, cold storage, and readable storage medium. The method includes the following steps: by setting up an ejector, and in defrosting mode, connecting the ejector's inlet to the bottom of a gas-liquid separator, and connecting the nozzle to the compressor's outlet, the high-temperature, high-pressure refrigerant generated by the compressor reaches the ejector's nozzle, creating a negative pressure within the ejector. This draws the liquid refrigerant from the bottom of the gas-liquid separator into the ejector, where it is vaporized by the high-temperature, high-pressure refrigerant generated by the compressor to obtain gaseous refrigerant, which is then output to the gas-liquid separator. This avoids excessive liquid refrigerant in the gas-liquid separator, preventing problems such as liquid slugging or oil shortage wear in the compressor.

Description

Technical Field

[0001] This invention relates to the field of refrigeration, and more particularly to a refrigeration unit control system, method, cold storage, and readable storage medium. Background Technology

[0002] Existing cryogenic cold storage refrigeration systems introduce high-temperature, high-pressure exhaust gas into the extremely low-temperature evaporator during defrosting, causing the refrigerant to condense instantly and generate a large amount of liquid return. This liquid then enters the gas-liquid separator. Since the gas-liquid separator can only passively dissolve the liquid, the large amount of liquid return can cause liquid level overflow, leading to liquid slugging in the compressor. Furthermore, the low-temperature liquid refrigerant will remain in the gas-liquid separator, causing the compressor to suffer from oil shortage and wear, which greatly affects the normal operation of the compressor. Summary of the Invention

[0003] The main objective of this invention is to provide a refrigeration unit control system, method, cold storage, and readable storage medium, aiming to solve the problem in the prior art where defrosting causes liquid return to enter the gas-liquid separator, affecting compressor operation.

[0004] To achieve the above objectives, the present invention provides a refrigeration unit control system, which includes a compressor, a gas-liquid separator, a condenser, an evaporator, a liquid receiver, and an ejector. The compressor's exhaust port is connected to the first end of the condenser; the second end of the condenser is connected to the first input end of the liquid receiver; the first output end of the liquid receiver is connected to the first end of the evaporator; and the second output end of the liquid receiver is connected to the nozzle of the ejector. The first end of the evaporator is connected to the compressor's exhaust port; the second end of the evaporator is also connected to the first end of the gas-liquid separator; the second end of the evaporator is also connected to the ejector's inlet; the ejector's inlet is also connected to the second end of the gas-liquid separator, which is located at its bottom. The ejector's nozzle is connected to the compressor's exhaust port; the ejector's outlet is connected to the third end of the gas-liquid separator; and the fourth end of the gas-liquid separator is connected to the compressor's inlet. Wherein: In defrost mode, the compressor, the evaporator, and the gas-liquid separator constitute a refrigerant circuit, and the exhaust port of the compressor is connected to the nozzle of the ejector, the second end of the gas-liquid separator is connected to the suction port of the ejector, and the outlet of the ejector is connected to the third end of the gas-liquid separator.

[0005] Optionally, the refrigeration unit control system further includes a first electronic expansion valve, a first solenoid valve, a second solenoid valve, a third solenoid valve, and a fourth solenoid valve; wherein: The first end of the first electronic expansion valve is connected to the second output end of the liquid reservoir, the first end of the first electronic expansion valve is also connected to the exhaust port of the compressor, and the second end of the first electronic expansion valve is connected to the nozzle of the ejector. The first solenoid valve is located between the compressor and the evaporator; The second solenoid valve is located between the evaporator and the gas-liquid separator; The third solenoid valve is located between the evaporator and the ejector inlet; The fourth solenoid valve is located between the second end of the gas-liquid separator and the inlet of the ejector; wherein: In the defrosting mode, the first electronic expansion valve, the first solenoid valve, the second solenoid valve, the third solenoid valve, and the fourth solenoid valve are activated.

[0006] Optionally, the refrigeration unit control system further includes a second electronic expansion valve; wherein: The second electronic expansion valve is disposed between the compressor's discharge port and the evaporator; wherein: After the defrosting mode is activated, the second electronic expansion valve opens, and the opening degree of the second electronic expansion valve is less than the preset activation opening degree.

[0007] Optionally, the refrigeration unit control system further includes a first electronic expansion valve, a third electronic expansion valve, a fifth solenoid valve, a sixth solenoid valve, a seventh solenoid valve, and an eighth solenoid valve; wherein: The fifth solenoid valve is connected between the exhaust port of the compressor and the condenser; The first output terminal of the liquid reservoir is connected to the evaporator in sequence through the sixth solenoid valve and the third electronic expansion valve; The seventh solenoid valve is connected between the second output terminal of the liquid reservoir and the first terminal of the first electronic expansion valve, and the second terminal of the first electronic expansion valve is connected to the nozzle of the ejector. The eighth solenoid valve is connected between the exhaust port of the compressor and the first end of the first electronic expansion valve; wherein: In the heat preservation mode, the fifth solenoid valve, the condenser, the liquid receiver, the sixth solenoid valve, the third electronic expansion valve, the evaporator, the third solenoid valve, the ejector, and the gas-liquid separator constitute a refrigerant circuit, and the eighth solenoid valve is closed.

[0008] To achieve the above objectives, the present invention also provides a refrigeration unit control method, which is applied to the refrigeration unit control system described above, and the refrigeration unit control method includes: If the defrost mode is triggered, the compressor, the evaporator, and the gas-liquid separator are controlled to form a refrigerant circuit, and the exhaust port of the compressor is connected to the nozzle of the ejector, the second end of the gas-liquid separator is connected to the suction port of the ejector, and the outlet of the ejector is connected to the third end of the gas-liquid separator.

[0009] Optionally, if the defrost mode is triggered, controlling the compressor, evaporator, ejector, and gas-liquid separator to form a refrigerant circuit includes: If the defrosting mode is triggered, the first solenoid valve, the second solenoid valve, the fourth solenoid valve, the eighth solenoid valve, the first electronic expansion valve, and the second electronic expansion valve will be opened, wherein the opening degree of the second electronic expansion valve is less than the preset start-up opening degree.

[0010] Optionally, the opening of the first solenoid valve, the second solenoid valve, the fourth solenoid valve, the eighth solenoid valve, the first electronic expansion valve, and the second electronic expansion valve includes: Obtain the real-time liquid level inside the gas-liquid separator; The opening degrees of the first electronic expansion valve and the second electronic expansion valve are adjusted according to the real-time liquid level, wherein the opening degree of the first electronic expansion valve is positively correlated with the real-time liquid level, and the opening degree of the second electronic expansion valve is negatively correlated with the real-time liquid level.

[0011] Optionally, the refrigeration unit control method further includes: Obtain the real-time temperature of the cooling zone and determine whether the real-time temperature is less than or equal to the target cooling temperature; If the real-time temperature is less than or equal to the target cooling temperature, the system switches to heat preservation mode, controlling the fifth solenoid valve, the sixth solenoid valve, the third electronic expansion valve, and the third solenoid valve to open, while the eighth solenoid valve closes.

[0012] To achieve the above objectives, the present invention also provides a cold storage facility, the cold storage facility including the refrigeration unit control system as described above, the cold storage facility further including a memory, a processor and a computer program stored on the memory and executable on the processor, the computer program being executed by the processor to implement the steps of the refrigeration unit control method as described above.

[0013] To achieve the above objectives, the present invention also provides a computer-readable storage medium storing a computer program, which, when executed by a processor, implements the steps of the refrigeration unit control method described above.

[0014] This invention proposes a refrigeration unit control system, method, cold storage, and readable storage medium. The refrigeration unit control system includes a compressor, a gas-liquid separator, a condenser, an evaporator, a liquid receiver, and an ejector. The compressor's discharge port is connected to a first end of the condenser, the second end of the condenser is connected to a first input end of the liquid receiver, the first output end of the liquid receiver is connected to a first end of the evaporator, and the second output end of the liquid receiver is connected to the nozzle of the ejector. The first end of the evaporator is connected to the compressor's discharge port, the second end of the evaporator is also connected to the first end of the gas-liquid separator, and the second end of the evaporator is also connected to the ejector's inlet. The ejector's inlet is also connected to the second end of the gas-liquid separator, which is located at the bottom. The ejector's nozzle is connected to the compressor's outlet, the ejector's outlet is connected to the third end of the gas-liquid separator, and the gas-liquid separator's fourth end is connected to the compressor's inlet. In defrost mode, the compressor, evaporator, and gas-liquid separator form a refrigerant circuit, with the compressor's outlet connected to the ejector's nozzle, the gas-liquid separator's second end connected to the ejector's inlet, and the ejector's outlet connected to the gas-liquid separator's third end. By setting up an ejector and connecting its inlet to the bottom of the gas-liquid separator and its nozzle to the compressor's outlet in defrost mode, the high-temperature, high-pressure refrigerant generated by the compressor reaches the nozzle of the ejector, creating a negative pressure inside the ejector. This draws the liquid refrigerant from the bottom of the gas-liquid separator into the ejector, where it is vaporized by the high-temperature, high-pressure refrigerant generated by the compressor, resulting in gaseous refrigerant that is then output to the gas-liquid separator. This avoids excessive liquid refrigerant in the gas-liquid separator, preventing problems such as liquid slugging or oil shortage wear in the compressor. Attached Figure Description

[0015] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with the invention and, together with the description, serve to explain the principles of the invention.

[0016] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, for those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0017] Figure 1 This is a schematic diagram of the refrigeration unit control system of the present invention; Figure 2 This is a flowchart illustrating the mode switching process of the refrigeration unit control method of the present invention. Figure 3 This is a schematic diagram of the refrigeration unit control method of the present invention; Figure 4 This is a schematic diagram of the modular structure of the cold storage of the present invention.

[0018] Explanation of icon numbers: Detailed Implementation

[0019] It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention. To enable those skilled in the art to better understand the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present application, and not all of them. Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of this application.

[0020] This invention provides a refrigeration unit control system, see below. Figure 1 , Figure 1 This is a schematic diagram of the structure of the refrigeration unit control system of the present invention. The refrigeration unit control system includes a compressor Q1, a gas-liquid separator B1, a condenser C1, an evaporator Z1, a liquid receiver O1, and an ejector Y1. The discharge port of compressor Q1 is connected to the first end of condenser C1, the second end of condenser C1 is connected to the first input end of liquid receiver O1, the first output end of liquid receiver O1 is connected to the first end of evaporator Z1, and the second output end of liquid receiver O1 is connected to the nozzle of ejector Y1; the first end of evaporator Z1 is connected to the discharge port of compressor Q1, the second end of evaporator Z1 is also connected to the first end of gas-liquid separator B1, the second end of evaporator Z1 is also connected to the inlet of ejector Y1, the inlet of ejector Y1 is also connected to the second end of gas-liquid separator B1, and the second end of gas-liquid separator B1 is located at the bottom of gas-liquid separator B1; the nozzle of ejector Y1 is connected to the discharge port of compressor Q1, the outlet of ejector Y1 is connected to the third end of gas-liquid separator B1, and the fourth end of gas-liquid separator B1 is connected to the inlet of compressor Q1; wherein: In defrost mode, the compressor Q1, the evaporator Z1, and the gas-liquid separator B1 form a refrigerant circuit. The exhaust port of the compressor Q1 is connected to the nozzle of the ejector Y1, the second end of the gas-liquid separator B1 is connected to the suction port of the ejector Y1, and the outlet of the ejector Y1 is connected to the third end of the gas-liquid separator B1.

[0021] In cooling mode, compressor Q1, condenser C1, receiver O1, evaporator Z1, and gas-liquid separator B1 constitute the refrigerant circuit. The high-temperature, high-pressure refrigerant output from compressor Q1 reaches condenser C1 for heat exchange and then flows into receiver O1. The refrigerant in receiver O1 reaches evaporator Z1 for heat exchange, and the refrigerant after heat exchange is output to gas-liquid separator B1 and then supplied to compressor Q1 to complete the cycle.

[0022] The defrost mode is used to melt the frost on the evaporator Z1. Understandably, in cooling mode, the refrigerant absorbs heat from the environment at the evaporator Z1, resulting in a lower temperature at that location and thus frost formation. Excessive frost on the evaporator Z1 can affect the cooling performance of the refrigeration unit; therefore, defrosting the evaporator Z1 is necessary. The specific triggering method for the defrost mode can be set based on actual needs, such as manual triggering, triggering at a fixed time interval, or detecting the frost condition on the evaporator Z1 and triggering it when defrost conditions are met. In defrosting mode, high-temperature refrigerant is delivered to evaporator Z1 to raise the temperature of evaporator Z1, thereby defrosting evaporator Z1. After the refrigerant flows through evaporator Z1, it releases heat, cools down and becomes liquid, and is then output to gas-liquid separator B1. When there is too much liquid refrigerant in gas-liquid separator B1, it will cause liquid slugging in compressor Q1. At the same time, low-temperature liquid refrigerant will remain in gas-liquid separator B1, causing compressor Q1 to lack oil and wear.

[0023] In this embodiment, an ejector Y1 is added to the refrigeration unit. The inlet of ejector Y1 is connected to the second end of the bottom of gas-liquid separator B1, the outlet is connected to the third end of gas-liquid separator B1, and the nozzle is connected to the exhaust port of compressor Q1. It can be understood that ejector Y1 is a non-powered fluid transport device. When high-pressure fluid flows into the nozzle of ejector Y1, a low-pressure area is generated inside ejector Y1. Based on this low-pressure area, the fluid in the inlet of ejector Y1 can be drawn in and output through the outlet.

[0024] In defrost mode, the compressor Q1 discharges high-temperature, high-pressure gas. One path is sent to the evaporator Z1 for defrosting, and the other path is sent to the nozzle of the ejector Y1 to create a negative pressure area within the ejector Y1. At this time, the liquid refrigerant at the bottom of the gas-liquid separator B1 is drawn into the ejector Y1 from the suction port under the negative pressure of the ejector Y1. Inside the ejector Y1, it is vaporized by the high-temperature, high-pressure gas discharged from the compressor Q1 discharge port, and converted into high-temperature, high-pressure dry vapor. Then, it returns to the gas-liquid separator B1 through the discharge port of the ejector Y1, and then enters the compressor Q1.

[0025] In defrost mode, ejector Y1 vaporizes the liquid refrigerant at the bottom of gas-liquid separator B1, thereby reducing the amount of liquid refrigerant in gas-liquid separator B1. This prevents excessive liquid refrigerant from entering compressor Q1 and causing liquid slugging, and also avoids the problem of oil shortage and wear in compressor Q1.

[0026] In this embodiment, by setting up an ejector Y1 and connecting its inlet to the bottom of the gas-liquid separator B1 in defrost mode, and connecting its nozzle to the outlet of the compressor Q1, the high-temperature, high-pressure refrigerant generated by the compressor Q1 reaches the nozzle of the ejector Y1, creating a negative pressure within the ejector Y1. This draws the liquid refrigerant at the bottom of the gas-liquid separator B1 into the ejector Y1, where it is vaporized by the high-temperature, high-pressure refrigerant generated by the compressor Q1, resulting in gaseous refrigerant that is then output to the gas-liquid separator B1. This avoids excessive liquid refrigerant in the gas-liquid separator B1, preventing problems such as liquid slugging or oil shortage wear in the compressor Q1.

[0027] Furthermore, the refrigeration unit control system also includes a first electronic expansion valve S1, a first solenoid valve T1, a second solenoid valve T2, a third solenoid valve T3, and a fourth solenoid valve T4; wherein: The first end of the first electronic expansion valve S1 is connected to the second output end of the liquid reservoir O1, the first end of the first electronic expansion valve S1 is also connected to the exhaust port of the compressor Q1, and the second end of the first electronic expansion valve S1 is connected to the nozzle of the ejector Y1. The first solenoid valve T1 is disposed between the compressor Q1 and the evaporator Z1; The second solenoid valve T2 is disposed between the evaporator Z1 and the gas-liquid separator B1; The third solenoid valve T3 is located between the evaporator Z1 and the suction port of the ejector Y1; The fourth solenoid valve T4 is located between the second end of the gas-liquid separator B1 and the suction port of the ejector Y1; wherein: In the defrosting mode, the first electronic expansion valve S1, the first solenoid valve T1, the second solenoid valve T2, the third solenoid valve T3, and the fourth solenoid valve T4 are turned on.

[0028] In this embodiment, the operating mode of the refrigeration unit is switched by setting an electronic expansion valve and a solenoid valve.

[0029] The first electronic expansion valve S1 is used to regulate the rate at which the refrigerant enters the nozzle of the ejector Y1.

[0030] The first solenoid valve T1 is used to control the on / off state between the compressor Q1 and the evaporator Z1.

[0031] The second solenoid valve T2 is used to control the on / off state between the gas-liquid separator B1 and the evaporator Z1.

[0032] The third solenoid valve T3 is used to control the on / off state between the suction port of ejector Y1 and evaporator Z1.

[0033] The fourth solenoid valve T4 is used to control the on / off state between the suction port of ejector Y1 and the second end of gas-liquid separator B1.

[0034] In defrosting mode, the first solenoid valve T1, the second solenoid valve T2, the third solenoid valve T3, and the fourth solenoid valve T4 are turned on, and the first electronic expansion valve S1 is turned on and its opening degree is controlled according to actual needs.

[0035] After the refrigerant flows out of the compressor Q1, it passes through the first solenoid valve T1, the evaporator Z1, and the second solenoid valve T2 in sequence to reach the gas-liquid separator B1; when the refrigerant passes through the evaporator Z1, it cools down and forms liquid refrigerant before being output to the gas-liquid separator B1. Another path leads to the nozzle of ejector Y1 through the first electronic expansion valve S1, creating a negative pressure area in ejector Y1, thereby drawing the liquid refrigerant at the bottom of gas-liquid separator B1 into ejector Y1 for vaporization, and then outputting it back to gas-liquid separator B1 through the third end of gas-liquid separator B1 after vaporization. Gas-liquid separator B1 provides refrigerant to compressor Q1 to achieve circulation.

[0036] Understandably, the larger the opening of the first electronic expansion valve S1, the greater the speed at which the refrigerant flows into the nozzle of the ejector Y1, resulting in a greater negative pressure within the ejector Y1, a greater ability to control the liquid refrigerant in the gas-liquid separator B1, and a better anti-liquid slugging effect. However, since both refrigerant lines originate from the compressor Q1, a larger opening of the first electronic expansion valve S1 results in a smaller flow rate of the other refrigerant line, which affects the defrosting effect of the evaporator Z1. Therefore, in practical applications, the opening of the first electronic expansion valve S1 can be adjusted based on actual needs.

[0037] In this embodiment, the refrigerant circuit in defrosting mode is constructed by setting an electronic expansion valve and a solenoid valve.

[0038] Furthermore, the refrigeration unit control system also includes a second electronic expansion valve S2; wherein: The second electronic expansion valve S2 is disposed between the exhaust port of the compressor Q1 and the evaporator Z1; wherein: After the defrosting mode is activated, the second electronic expansion valve S2 opens, and the opening degree of the second electronic expansion valve S2 is less than the preset activation opening degree.

[0039] In existing refrigeration units, a four-way valve is used to switch between refrigeration and defrosting modes. In this case, at the moment the four-way valve switches, the copper tube of the evaporator Z1 is at a low temperature. For example, for a refrigeration unit in a deep-cold storage room at -25°C, the temperature of the copper tube of the evaporator Z1 is -25°C. The high-temperature and high-pressure refrigerant output by the compressor Q1 directly impacts the copper tube of the evaporator Z1. The huge temperature difference will generate severe thermal stress and pressure change. This will not only cause system oscillation, but also lead to fatigue cracking of the solder pads of the copper tube of the evaporator Z1 in the long run, resulting in refrigerant leakage.

[0040] To address this issue, the four-way valve is omitted in this embodiment; instead, mode switching is achieved through a solenoid valve and an electronic expansion valve.

[0041] The preset start-up opening is the opening of the second electronic expansion valve S2 to avoid generating severe thermal stress and pressure changes. The specific value of the preset start-up opening can be set based on pre-calibration.

[0042] When switching to defrost mode, the first solenoid valve T1 and the second electronic expansion valve S2 open, with the opening degree of the second electronic expansion valve S2 being less than the preset start-up opening degree. At this time, the copper tube of the evaporator Z1 is in a low-temperature state. Under the opening degree limitation of the second electronic expansion valve S2, the high-temperature, high-pressure refrigerant output by the compressor Q1 slowly and quantitatively enters the evaporator Z1 to defrost the evaporator Z1, providing a preheating buffer for the evaporator Z1, thereby avoiding a large amount of high-temperature refrigerant being input into the evaporator Z1 in a short period of time, and avoiding the generation of instantaneous huge pressure difference and thermal stress. Afterwards, the opening degree of the second electronic expansion valve S2 can be adjusted based on the actual defrosting situation.

[0043] The larger the opening of the second electronic expansion valve S2, the faster the high-temperature, high-pressure refrigerant flows into the evaporator Z1, resulting in a better defrosting effect. However, this may lead to an increase in pressure difference and thermal stress. Therefore, the opening of the second electronic expansion valve S2 can be adjusted based on actual needs.

[0044] In defrosting mode, the first solenoid valve T1, the second solenoid valve T2, the third solenoid valve T3, and the fourth solenoid valve T4 are turned on, and the first electronic expansion valve S1 and the second electronic expansion valve S2 are turned on and their opening degree is controlled according to actual needs.

[0045] After the refrigerant flows out of the compressor Q1, it passes through the first solenoid valve T1, the second electronic expansion valve S2, the evaporator Z1, and the second solenoid valve T2 in sequence to reach the gas-liquid separator B1; when the refrigerant passes through the evaporator Z1, it cools down to form liquid refrigerant and is then output to the gas-liquid separator B1. Another path leads to the nozzle of ejector Y1 through the first electronic expansion valve S1, creating a negative pressure area in ejector Y1, thereby drawing the liquid refrigerant at the bottom of gas-liquid separator B1 into ejector Y1 for vaporization, and then outputting it back to gas-liquid separator B1 through the third end of gas-liquid separator B1 after vaporization. Gas-liquid separator B1 provides refrigerant to compressor Q1 to achieve circulation.

[0046] Understandably, the larger the opening of the first electronic expansion valve S1, the better the defrosting effect, the more liquid refrigerant flows into the gas-liquid separator B1, and the faster the liquid level in the gas-liquid separator B1 rises. However, if the liquid level in the gas-liquid separator B1 rises too quickly, it can also cause liquid slugging in the compressor Q1. Therefore, it is necessary to adjust the opening of the first electronic expansion valve S1 based on the liquid level in the gas-liquid separator B1.

[0047] A liquid level sensor is installed inside the gas-liquid separator B1.

[0048] Obtain the real-time liquid level inside the gas-liquid separator B1; The opening degrees of the first electronic expansion valve S1 and the second electronic expansion valve S2 are adjusted according to the real-time liquid level, wherein the opening degree of the first electronic expansion valve S1 is positively correlated with the real-time liquid level, and the opening degree of the second electronic expansion valve S2 is negatively correlated with the real-time liquid level.

[0049] The opening of the first electronic expansion valve S1 can control the amount of liquid refrigerant input into the gas-liquid separator B1, while the opening of the second electronic expansion valve S2 can control the amount of liquid refrigerant drawn into the ejector Y1 from the gas-liquid separator B1. Therefore, by adjusting the first electronic expansion valve S1 and the second electronic expansion valve S2, the liquid level balance in the gas-liquid separator B1 can be achieved.

[0050] When the liquid level in the gas-liquid separator B1 is too high, it needs to be lowered. This is achieved simultaneously in two ways: first, by reducing the opening of the first electronic expansion valve S1, thereby reducing the amount of liquid refrigerant output from the evaporator Z1 and slowing down the rise in liquid level; second, by increasing the opening of the second electronic expansion valve S2, thereby increasing the amount of liquid refrigerant drawn into the ejector Y1 and accelerating the drop in liquid level. Both methods work together to reduce the amount of liquid refrigerant in the gas-liquid separator B1. When the liquid level in the gas-liquid separator B1 is too low, the opening of the first electronic expansion valve S1 can be increased to improve the defrosting effect of the evaporator Z1. At the same time, the opening of the second electronic expansion valve S2 can be reduced to prevent insufficient refrigerant from flowing into the evaporator Z1.

[0051] Therefore, in this embodiment, the opening degree of the first electronic expansion valve S1 is set to be positively correlated with the real-time liquid level, and the opening degree of the second electronic expansion valve S2 is set to be negatively correlated with the real-time liquid level; thereby, dynamic balance of the liquid level in the gas-liquid separator B1 can be achieved.

[0052] When adjusting the opening of the first electronic expansion valve S1 and the second electronic expansion valve S2, the adjustment method can be set according to actual needs. For example, a fixed adjustment step size can be set. Each time the opening of the first electronic expansion valve S1 and the second electronic expansion valve S2 needs to be adjusted, the opening can be increased or decreased by a fixed adjustment step size, thereby avoiding system instability caused by large-scale adjustment. Alternatively, the adjustment step size can be determined based on the real-time liquid level in the gas-liquid separator B1. For example, the appropriate adjustment step size for different real-time liquid levels in the gas-liquid separator B1 can be determined in advance based on experiments. After determining the real-time liquid level, the corresponding adjustment step size can be matched.

[0053] Furthermore, the refrigeration unit control system also includes a first electronic expansion valve S1, a third electronic expansion valve S3, a fifth solenoid valve T5, a sixth solenoid valve T6, a seventh solenoid valve T7, and an eighth solenoid valve T8; wherein: The fifth solenoid valve T5 is connected between the exhaust port of the compressor Q1 and the condenser C1; The first output terminal of the liquid reservoir O1 is connected to the evaporator Z1 in sequence through the sixth solenoid valve T6 and the third electronic expansion valve S3; The seventh solenoid valve T7 is connected between the second output terminal of the liquid reservoir O1 and the first terminal of the first electronic expansion valve S1, and the second terminal of the first electronic expansion valve S1 is connected to the nozzle of the ejector Y1. The eighth solenoid valve T8 is connected between the exhaust port of the compressor Q1 and the first end of the first electronic expansion valve S1; wherein: In the heat preservation mode, the fifth solenoid valve T5, the condenser C1, the liquid receiver O1, the sixth solenoid valve T6, the third electronic expansion valve S3, the evaporator Z1, the third solenoid valve T3, the ejector Y1, and the gas-liquid separator B1 constitute a refrigerant circuit, and the eighth solenoid valve T8 is closed.

[0054] In existing refrigeration units, in order to maintain deep-cold operation, the single-stage compressor Q1 system needs to maintain an extremely low evaporation temperature. However, the huge heat exchange temperature difference causes the evaporator Z1 to over-dehumidify, resulting in high dry loss of goods in the cold storage. At the same time, it also causes significant irreversible losses in the throttling expansion process, making it difficult to improve the system's COP (Coefficient of Performance).

[0055] To address this issue, in this embodiment, an ejector Y1 is used to construct a heat preservation mode, thus avoiding excessive dehumidification.

[0056] The heat preservation mode is the mode that the refrigeration unit switches to after reaching the target cooling temperature in the cooling mode to maintain the target cooling temperature.

[0057] In heat preservation mode, the fifth solenoid valve T5, the sixth solenoid valve T6, and the third solenoid valve T3 are turned on, and the third electronic expansion valve S3 is turned on and its opening degree is controlled according to actual needs, such as PID adjustment based on the real-time temperature of the refrigeration zone and the target refrigeration temperature.

[0058] After the refrigerant flows out of the compressor Q1, it passes through the fifth solenoid valve T5, condenser C1, liquid receiver O1, sixth solenoid valve T6, third electronic expansion valve S3, evaporator Z1, third solenoid valve T3, ejector Y1 in sequence to reach the gas-liquid separator B1. The gas-liquid separator B1 provides refrigerant to the compressor Q1 to achieve circulation. Meanwhile, the refrigerant in the receiver O1 also reaches the nozzle of the ejector Y1 through the seventh solenoid valve T7 and the first electronic expansion valve S1.

[0059] The high-temperature, atmospheric-pressure refrigerant in the receiver O1 acts as a driving force, flowing through the first electronic expansion valve S1 to the nozzle of the ejector Y1. This creates a negative pressure within the ejector Y1, which actively draws back the gas from the evaporator Z1. This increases the operating pressure and evaporation temperature of the evaporator Z1, reduces the heat exchange temperature difference of the evaporator Z1, thereby reducing the dehumidification rate of the evaporator Z1 in the cold storage, suppressing the desiccation of goods in the cold storage, and improving the system's energy efficiency ratio. At the same time, reducing the heat exchange temperature difference of the evaporator Z1 also slows down the frosting of the evaporator Z1.

[0060] The overall principle of the refrigeration unit is explained below: In cooling mode: The fifth solenoid valve T5, the sixth solenoid valve T6, and the second solenoid valve T2 are open; the third electronic expansion valve S3 is open and performs PID regulation based on the real-time temperature of the refrigeration zone and the target refrigeration temperature. Other solenoid valves and electronic expansion valves are closed; The high-temperature, high-pressure refrigerant output by compressor Q1 reaches the condenser C1 for heat exchange and then flows into the liquid receiver O1. The refrigerant in the liquid receiver O1 reaches the evaporator Z1 for heat exchange, and the refrigerant after heat exchange is output to the gas-liquid separator B1 and then supplied to compressor Q1 to achieve circulation.

[0061] At this time, the refrigeration unit executes a standard single-stage refrigeration cycle to maximize its cooling capacity and achieve rapid cooling in the initial stage of receiving goods.

[0062] In heat preservation mode: The fifth solenoid valve T5, the sixth solenoid valve T6, the seventh solenoid valve T7, and the third solenoid valve T3 are opened; the first electronic expansion valve S1 is opened and its opening degree is adjusted according to actual needs; the third electronic expansion valve S3 is opened and its PID adjustment is performed based on the real-time temperature of the refrigeration zone and the target refrigeration temperature. Other solenoid valves and electronic expansion valves are closed; After the refrigerant flows out of the compressor Q1, it passes through the fifth solenoid valve T5, condenser C1, liquid receiver O1, sixth solenoid valve T6, third electronic expansion valve S3, evaporator Z1, third solenoid valve T3, ejector Y1 in sequence to reach the gas-liquid separator B1. The gas-liquid separator B1 provides refrigerant to the compressor Q1 to achieve circulation. Meanwhile, the refrigerant in the receiver O1 also reaches the nozzle of the ejector Y1 through the seventh solenoid valve T7 and the first electronic expansion valve S1.

[0063] In Frost Defrost Mode: The first solenoid valve T1, the second solenoid valve T2, the third solenoid valve T3, the fourth solenoid valve T4, and the eighth solenoid valve T8 are open; the first electronic expansion valve S1 and the second electronic expansion valve S2 are open and their opening degree is adjusted based on the liquid level of the gas-liquid separator B1. Other solenoid valves and electronic expansion valves are closed; After the refrigerant flows out of the compressor Q1, it passes through the first solenoid valve T1, the second electronic expansion valve S2, the evaporator Z1, and the second solenoid valve T2 in sequence to reach the gas-liquid separator B1; when the refrigerant passes through the evaporator Z1, it cools down to form liquid refrigerant and is then output to the gas-liquid separator B1. Another path leads to the nozzle of ejector Y1 through the first electronic expansion valve S1, creating a negative pressure area in ejector Y1, thereby drawing the liquid refrigerant at the bottom of gas-liquid separator B1 into ejector Y1 for vaporization, and then outputting it back to gas-liquid separator B1 through the third end of gas-liquid separator B1 after vaporization. Gas-liquid separator B1 provides refrigerant to compressor Q1 to achieve circulation.

[0064] Meanwhile, the opening degree of the first electronic expansion valve S1 is set to be positively correlated with the real-time liquid level, and the opening degree of the second electronic expansion valve S2 is set to be negatively correlated with the real-time liquid level; thus achieving dynamic balance of the liquid level in the gas-liquid separator B1.

[0065] This invention provides a refrigeration unit control method, referring to... Figure 1 , Figure 1 This is a flowchart illustrating the first embodiment of the refrigeration unit control method of the present invention. The refrigeration unit control method is applied to the refrigeration unit control system described above, and the method includes the following steps: Step S10: If the defrosting mode is triggered, the compressor Q1, the evaporator Z1, and the gas-liquid separator B1 are controlled to form a refrigerant circuit, and the exhaust port of the compressor Q1 is connected to the nozzle of the ejector Y1, the second end of the gas-liquid separator B1 is connected to the suction port of the ejector Y1, and the discharge port of the ejector Y1 is connected to the third end of the gas-liquid separator B1.

[0066] The defrost mode is used to melt the frost on the evaporator Z1. Understandably, in cooling mode, the refrigerant absorbs heat from the environment at the evaporator Z1, resulting in a lower temperature at that location and thus frost formation. Excessive frost on the evaporator Z1 can affect the cooling performance of the refrigeration unit; therefore, defrosting the evaporator Z1 is necessary. The specific triggering method for the defrost mode can be set based on actual needs, such as manual triggering, triggering at a fixed time interval, or detecting the frost condition on the evaporator Z1 and triggering it when defrost conditions are met. In defrosting mode, high-temperature refrigerant is delivered to evaporator Z1 to raise the temperature of evaporator Z1, thereby defrosting evaporator Z1. After the refrigerant flows through evaporator Z1, it releases heat, cools down and becomes liquid, and is then output to gas-liquid separator B1. When there is too much liquid refrigerant in gas-liquid separator B1, it will cause liquid slugging in compressor Q1. At the same time, low-temperature liquid refrigerant will remain in gas-liquid separator B1, causing compressor Q1 to lack oil and wear.

[0067] In this embodiment, an ejector Y1 is added to the refrigeration unit. The inlet of ejector Y1 is connected to the second end of the bottom of gas-liquid separator B1, the outlet is connected to the third end of gas-liquid separator B1, and the nozzle is connected to the exhaust port of compressor Q1. It can be understood that ejector Y1 is a non-powered fluid transport device. When high-pressure fluid flows into the nozzle of ejector Y1, a low-pressure area is generated inside ejector Y1. Based on this low-pressure area, the fluid in the inlet of ejector Y1 can be drawn in and output through the outlet.

[0068] In defrost mode, the compressor Q1 discharges high-temperature, high-pressure gas. One path is sent to the evaporator Z1 for defrosting, and the other path is sent to the nozzle of the ejector Y1 to create a negative pressure area within the ejector Y1. At this time, the liquid refrigerant at the bottom of the gas-liquid separator B1 is drawn into the ejector Y1 from the suction port under the negative pressure of the ejector Y1. Inside the ejector Y1, it is vaporized by the high-temperature, high-pressure gas discharged from the compressor Q1 discharge port, and converted into high-temperature, high-pressure dry vapor. Then, it returns to the gas-liquid separator B1 through the discharge port of the ejector Y1, and then enters the compressor Q1.

[0069] In defrost mode, ejector Y1 vaporizes the liquid refrigerant at the bottom of gas-liquid separator B1, thereby reducing the amount of liquid refrigerant in gas-liquid separator B1. This prevents excessive liquid refrigerant from entering compressor Q1 and causing liquid slugging, and also avoids the problem of oil shortage and wear in compressor Q1.

[0070] In this embodiment, by setting up an ejector Y1 and connecting its inlet to the bottom of the gas-liquid separator B1 in defrost mode, and connecting its nozzle to the outlet of the compressor Q1, the high-temperature, high-pressure refrigerant generated by the compressor Q1 reaches the nozzle of the ejector Y1, creating a negative pressure within the ejector Y1. This draws the liquid refrigerant at the bottom of the gas-liquid separator B1 into the ejector Y1, where it is vaporized by the high-temperature, high-pressure refrigerant generated by the compressor Q1, resulting in gaseous refrigerant that is then output to the gas-liquid separator B1. This avoids excessive liquid refrigerant in the gas-liquid separator B1, preventing problems such as liquid slugging or oil shortage wear in the compressor Q1.

[0071] Furthermore, in the second embodiment of the refrigeration unit control method of the present invention based on the first embodiment of the present invention, step S10 includes the following steps: Step S11: If the defrosting mode is triggered, control the first solenoid valve T1, the second solenoid valve T2, the fourth solenoid valve T4, the eighth solenoid valve T8, the first electronic expansion valve S1, and the second electronic expansion valve S2 to open, wherein the opening degree of the second electronic expansion valve S2 is less than the preset start-up opening degree.

[0072] In defrosting mode, the first solenoid valve T1, the second solenoid valve T2, the third solenoid valve T3, and the fourth solenoid valve T4 are turned on, and the first electronic expansion valve S1 is turned on and its opening degree is controlled according to actual needs.

[0073] After the refrigerant flows out of the compressor Q1, it passes through the first solenoid valve T1, the evaporator Z1, and the second solenoid valve T2 in sequence to reach the gas-liquid separator B1; when the refrigerant passes through the evaporator Z1, it cools down and forms liquid refrigerant before being output to the gas-liquid separator B1. Another path leads to the nozzle of ejector Y1 through the first electronic expansion valve S1, creating a negative pressure area in ejector Y1, thereby drawing the liquid refrigerant at the bottom of gas-liquid separator B1 into ejector Y1 for vaporization, and then outputting it back to gas-liquid separator B1 through the third end of gas-liquid separator B1 after vaporization. Gas-liquid separator B1 provides refrigerant to compressor Q1 to achieve circulation.

[0074] Understandably, the larger the opening of the first electronic expansion valve S1, the greater the speed at which the refrigerant flows into the nozzle of the ejector Y1, resulting in a greater negative pressure within the ejector Y1, a greater ability to control the liquid refrigerant in the gas-liquid separator B1, and a better anti-liquid slugging effect. However, since both refrigerant lines originate from the compressor Q1, a larger opening of the first electronic expansion valve S1 results in a smaller flow rate of the other refrigerant line, which affects the defrosting effect of the evaporator Z1. Therefore, in practical applications, the opening of the first electronic expansion valve S1 can be adjusted based on actual needs.

[0075] In this embodiment, the refrigerant circuit in defrosting mode is constructed by setting an electronic expansion valve and a solenoid valve.

[0076] Further, step S11 is followed by: Step S12: Obtain the real-time liquid level inside the gas-liquid separator B1; Step S13: Adjust the opening degree of the first electronic expansion valve S1 and the second electronic expansion valve S2 according to the real-time liquid level, wherein the opening degree of the first electronic expansion valve S1 is positively correlated with the real-time liquid level, and the opening degree of the second electronic expansion valve S2 is negatively correlated with the real-time liquid level.

[0077] The opening of the first electronic expansion valve S1 can control the amount of liquid refrigerant input into the gas-liquid separator B1, while the opening of the second electronic expansion valve S2 can control the amount of liquid refrigerant drawn into the ejector Y1 from the gas-liquid separator B1. Therefore, by adjusting the first electronic expansion valve S1 and the second electronic expansion valve S2, the liquid level balance in the gas-liquid separator B1 can be achieved.

[0078] When the liquid level in the gas-liquid separator B1 is too high, it needs to be lowered. This is achieved simultaneously in two ways: first, by reducing the opening of the first electronic expansion valve S1, thereby reducing the amount of liquid refrigerant output from the evaporator Z1 and slowing down the rise in liquid level; second, by increasing the opening of the second electronic expansion valve S2, thereby increasing the amount of liquid refrigerant drawn into the ejector Y1 and accelerating the drop in liquid level. Both methods work together to reduce the amount of liquid refrigerant in the gas-liquid separator B1. When the liquid level in the gas-liquid separator B1 is too low, the opening of the first electronic expansion valve S1 can be increased to improve the defrosting effect of the evaporator Z1. At the same time, the opening of the second electronic expansion valve S2 can be reduced to prevent insufficient refrigerant from flowing into the evaporator Z1.

[0079] Therefore, in this embodiment, the opening degree of the first electronic expansion valve S1 is set to be positively correlated with the real-time liquid level, and the opening degree of the second electronic expansion valve S2 is set to be negatively correlated with the real-time liquid level; thereby, dynamic balance of the liquid level in the gas-liquid separator B1 can be achieved.

[0080] When adjusting the opening of the first electronic expansion valve S1 and the second electronic expansion valve S2, the adjustment method can be set according to actual needs. For example, a fixed adjustment step size can be set. Each time the opening of the first electronic expansion valve S1 and the second electronic expansion valve S2 needs to be adjusted, the opening can be increased or decreased by a fixed adjustment step size, thereby avoiding system instability caused by large-scale adjustment. Alternatively, the adjustment step size can be determined based on the real-time liquid level in the gas-liquid separator B1. For example, the appropriate adjustment step size for different real-time liquid levels in the gas-liquid separator B1 can be determined in advance based on experiments. After determining the real-time liquid level, the corresponding adjustment step size can be matched.

[0081] Furthermore, the refrigeration unit control method further includes: Step S20: Obtain the real-time temperature of the cooling zone and determine whether the real-time temperature is less than or equal to the target cooling temperature; Step S30: If the real-time temperature is less than or equal to the target cooling temperature, switch to the heat preservation mode, control the fifth solenoid valve T5, the sixth solenoid valve T6, the third electronic expansion valve S3, and the third solenoid valve T3 to open, and the eighth solenoid valve T8 to close.

[0082] The refrigeration area refers to the object being refrigerated by the refrigeration unit; for example, if a refrigeration unit is installed for a cold storage facility, the corresponding refrigeration area is the low-temperature storage space within the cold storage facility.

[0083] The target cooling temperature is the temperature that the cooling zone needs to reach; the specific value of the target control temperature can be set based on actual needs.

[0084] After the refrigeration unit is started, it operates in refrigeration mode. When the real-time temperature of the refrigeration area drops to less than or equal to the target refrigeration temperature, it is considered that the refrigeration demand of the refrigeration area has been met. Therefore, in order to avoid the energy efficiency ratio from decreasing due to continued refrigeration, this embodiment switches to heat preservation mode to avoid the problem of excessive dehumidification.

[0085] In heat preservation mode, the fifth solenoid valve T5, the sixth solenoid valve T6, and the third solenoid valve T3 are turned on, and the third electronic expansion valve S3 is turned on and its opening degree is controlled according to actual needs, such as PID adjustment based on the real-time temperature of the refrigeration zone and the target refrigeration temperature.

[0086] After the refrigerant flows out of the compressor Q1, it passes through the fifth solenoid valve T5, condenser C1, liquid receiver O1, sixth solenoid valve T6, third electronic expansion valve S3, evaporator Z1, third solenoid valve T3, ejector Y1 in sequence to reach the gas-liquid separator B1. The gas-liquid separator B1 provides refrigerant to the compressor Q1 to achieve circulation. Meanwhile, the refrigerant in the receiver O1 also reaches the nozzle of the ejector Y1 through the seventh solenoid valve T7 and the first electronic expansion valve S1.

[0087] The high-temperature, atmospheric-pressure refrigerant in the receiver O1 acts as a driving force, flowing through the first electronic expansion valve S1 to the nozzle of the ejector Y1. This creates a negative pressure within the ejector Y1, which actively draws back the gas from the evaporator Z1. This increases the operating pressure and evaporation temperature of the evaporator Z1, reduces the heat exchange temperature difference of the evaporator Z1, thereby reducing the dehumidification rate of the evaporator Z1 in the cold storage, suppressing the desiccation of goods in the cold storage, and improving the system's energy efficiency ratio. At the same time, reducing the heat exchange temperature difference of the evaporator Z1 also slows down the frosting of the evaporator Z1.

[0088] The overall implementation of this application is described below: See Figure 3 This application sets three control modes. Mode 1: Cooling mode; Mode 2: Heat preservation mode, used to suppress dryness loss; Mode 3: Defrosting mode, actively preventing liquid slugging.

[0089] Mode 1: Open the fifth solenoid valve T5, the sixth solenoid valve T6, and the second solenoid valve T2. Forcefully close all valves associated with ejector Y1. The third electronic expansion valve S3 activates PID regulation, while the first electronic expansion valve S1 is locked. The refrigerant bypasses ejector Y1 and returns directly, eliminating the suction resistance caused by the internal constriction of ejector Y1. The system reverts to a standard single-stage refrigeration cycle, maximizing cooling capacity and achieving rapid temperature rise during the initial loading phase.

[0090] Mode 2: After the cold storage temperature reaches the standard and enters the insulation period, close the second solenoid valve T2. Open the seventh solenoid valve T7 to introduce high-pressure room-temperature liquid into the first electronic expansion valve S1 as the driving flow; open the third solenoid valve T3 to connect the outlet of evaporator Z1 with the side suction port of ejector Y1. Close other valves. The high-pressure liquid injected by the first electronic expansion valve S1 drives ejector Y1 to actively draw back gas from evaporator Z1 and recover the throttling expansion work. This significantly increases the operating pressure and evaporation temperature of evaporator Z1, effectively reduces the heat exchange temperature difference, greatly reduces the dehumidification rate of the cold storage, and suppresses the dry loss of goods; at the same time, it delays the frosting cycle and improves the overall energy efficiency ratio under deep-cryogenic conditions.

[0091] Mode 3: Close the fifth solenoid valve T5, the sixth solenoid valve T6, and the third electronic expansion valve S3. Open the second electronic expansion valve S2 and the first solenoid valve T1 to perform a soft-start valve opening; simultaneously open the eighth solenoid valve T8 to introduce extremely high-temperature exhaust gas into the first electronic expansion valve S1; open the fourth solenoid valve T4 to connect the bottom of the gas-liquid separator B1 with the suction port of the ejector Y1. The activation control of the second electronic expansion valve S2 allows the high-temperature gas flow to slowly and quantitatively enter the evaporator Z1, providing preheating buffer and eliminating pipeline vibration and abnormal noise caused by instantaneous huge pressure difference and thermal stress.

[0092] Active anti-liquid slugging and forced oil return: The first electronic expansion valve S1 sprays high-temperature hot gas to generate a huge negative pressure, drawing the dangerous ice-water mixture (and deposited refrigeration oil) from the bottom of the gas-liquid separator B1 into the ejector Y1. The high-temperature airflow then "dries" it into safe dry steam, which returns to the compressor Q1, thus preventing liquid slugging. Dynamic liquid level balance: If defrosting is extremely vigorous and causes a surge in liquid level, the system adaptively closes the second electronic expansion valve S2 (reducing liquid discharge at the source) and opens the first electronic expansion valve S1 (enhancing suction), ensuring that the defrosting heat input and anti-liquid slugging suction capacity are always in optimal dynamic balance.

[0093] Beneficial effects: 1. It breaks through the limitations of the traditional ejector Y1, which has a single and fixed function. By cleverly arranging a multi-stage solenoid valve group and a bypass direct-connect valve, the ejector Y1 achieves dynamic reconfiguration of the medium under different operating conditions: it is used as "gas phase suction" during refrigeration and preservation, as "liquid phase suction" during defrosting, and as a physical bypass in case of rapid freezing or failure. This greatly improves the utilization rate of the core expensive hardware and the fault tolerance of the system.

[0094] 2. Establish a directional physical channel between the dangerous liquid accumulation area at the bottom of the gas-liquid separator B1 and the side suction port of the ejector Y1. Utilize the high-temperature exhaust gas from the compressor Q1 during defrosting as a power source to actively and forcibly draw the dangerous liquid into the ejector Y1, where it undergoes intense flash vaporization and heat-mass exchange, eliminating the source of liquid slugging and achieving forced oil return.

[0095] 3. The directional switching valve is abandoned, and an independent ejector power regulating valve and defrost main circuit regulating valve are innovatively adopted. The control system is based on the coordinated PID regulation of two electronic expansion valves (such as "soft start" and "dynamic balance of extraction and discharge" during defrosting), and the refrigeration main valve and defrost main valve are physically and logically isolated to prevent cross-flow of hot and cold media.

[0096] It should be noted that, for the sake of simplicity, the foregoing method embodiments are all described as a series of actions. However, those skilled in the art should understand that this application is not limited to the described order of actions, as some steps may be performed in other orders or simultaneously according to this application. Furthermore, those skilled in the art should also understand that the embodiments described in the specification are preferred embodiments, and the actions and modules involved are not necessarily essential to this application.

[0097] Through the above description of the embodiments, those skilled in the art can clearly understand that the methods according to the above embodiments can be implemented by means of software plus necessary general-purpose hardware platforms. Of course, they can also be implemented by hardware, but in many cases the former is a better implementation method. Based on this understanding, the technical solution of this application, in essence, or the part that contributes to the prior art, can be embodied in the form of a software product. This computer software product is stored in a storage medium (such as ROM / RAM, magnetic disk, optical disk), and includes several instructions to cause a terminal device (which may be a mobile phone, computer, server, or network device, etc.) to execute the methods described in the various embodiments of this application.

[0098] Reference Figure 4 In terms of hardware structure, the cold storage may include the refrigeration unit control system described above. The cold storage also includes components such as a communication module 10, a memory 20, and a processor 30. In the cold storage, the processor 30 is connected to both the memory 20 and the communication module 10. The memory 20 stores a computer program, which is simultaneously executed by the processor 30. When the computer program is executed, it implements the steps of the method embodiments described above.

[0099] The communication module 10 can connect to external communication devices via a network. The communication module 10 can receive requests from the external communication devices and can also send requests, instructions, and information to the external communication devices, which can be other cold storage facilities, servers, or IoT devices, such as televisions, etc.

[0100] The memory 20 can be used to store software programs and various data. The memory 20 may primarily include a program storage area and a data storage area. The program storage area may store the operating system, at least one application program required for a function (e.g., controlling the compressor, evaporator, and gas-liquid separator to form a refrigerant circuit if the defrost mode is triggered); the data storage area may include a database, storing data or information created based on system usage. Furthermore, the memory 20 may include high-speed random access memory and may also include non-volatile memory, such as at least one disk storage device, flash memory device, or other volatile solid-state storage device.

[0101] Processor 30 is the control center of the cold storage. It connects various parts of the cold storage via various interfaces and lines. By running or executing software programs and / or modules stored in memory 20, and by calling data stored in memory 20, it performs various functions and processes data, thereby providing overall monitoring of the cold storage. Processor 30 may include one or more processing units; optionally, processor 30 may integrate an application processor and a modem processor. The application processor mainly handles the operating system, user interface, and applications, while the modem processor mainly handles wireless communication. It is understood that the modem processor may not be integrated into processor 30.

[0102] although Figure 4 Not shown, but the aforementioned cold storage may also include a circuit control module, which is used to connect to a power source to ensure the normal operation of other components. Those skilled in the art will understand that... Figure 4 The cold storage structure shown does not constitute a limitation on the cold storage, and may include more or fewer components than shown, or combine certain components, or have different component arrangements.

[0103] The present invention also proposes a computer-readable storage medium having a computer program stored thereon. The computer-readable storage medium may be... Figure 4 The storage 20 in the cold storage can also be at least one of ROM (Read-Only Memory) / RAM (Random Access Memory), magnetic disk, optical disk, etc. The computer-readable storage medium includes a number of instructions to cause a terminal device with a processor (which may be a television, automobile, mobile phone, computer, server, terminal, or network device, etc.) to execute the methods described in the various embodiments of the present invention.

[0104] In this invention, the terms "first," "second," "third," "fourth," and "fifth" are used for descriptive purposes only and should not be construed as indicating or implying relative importance. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0105] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0106] Although embodiments of the present invention have been shown and described above, the scope of protection of the present invention is not limited thereto. It is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, and substitutions to the above embodiments within the scope of the present invention, and such changes, modifications, and substitutions should all be covered within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A refrigeration unit control system, characterized in that, The refrigeration unit control system includes a compressor, a gas-liquid separator, a condenser, an evaporator, a liquid receiver, and an ejector. The compressor's exhaust port is connected to the first end of the condenser; the second end of the condenser is connected to the first input end of the liquid receiver; the first output end of the liquid receiver is connected to the first end of the evaporator; and the second output end of the liquid receiver is connected to the nozzle of the ejector. The first end of the evaporator is connected to the compressor's exhaust port; the second end of the evaporator is also connected to the first end of the gas-liquid separator; the second end of the evaporator is also connected to the ejector's inlet; the ejector's inlet is also connected to the second end of the gas-liquid separator, which is located at its bottom. The ejector's nozzle is connected to the compressor's exhaust port; the ejector's outlet is connected to the third end of the gas-liquid separator; and the fourth end of the gas-liquid separator is connected to the compressor's inlet. Wherein: In defrost mode, the compressor, the evaporator, and the gas-liquid separator constitute a refrigerant circuit, and the exhaust port of the compressor is connected to the nozzle of the ejector, the second end of the gas-liquid separator is connected to the suction port of the ejector, and the outlet of the ejector is connected to the third end of the gas-liquid separator.

2. The refrigeration unit control system as described in claim 1, characterized in that, The refrigeration unit control system further includes a first electronic expansion valve, a first solenoid valve, a second solenoid valve, a third solenoid valve, and a fourth solenoid valve; wherein: The first end of the first electronic expansion valve is connected to the second output end of the liquid reservoir, the first end of the first electronic expansion valve is also connected to the exhaust port of the compressor, and the second end of the first electronic expansion valve is connected to the nozzle of the ejector. The first solenoid valve is located between the compressor and the evaporator; The second solenoid valve is located between the evaporator and the gas-liquid separator; The third solenoid valve is located between the evaporator and the ejector inlet; The fourth solenoid valve is located between the second end of the gas-liquid separator and the inlet of the ejector; wherein: In the defrosting mode, the first electronic expansion valve, the first solenoid valve, the second solenoid valve, the third solenoid valve, and the fourth solenoid valve are activated.

3. The refrigeration unit control system as described in claim 1, characterized in that, The refrigeration unit control system also includes a second electronic expansion valve; wherein: The second electronic expansion valve is disposed between the compressor's discharge port and the evaporator; wherein: After the defrosting mode is activated, the second electronic expansion valve opens, and the opening degree of the second electronic expansion valve is less than the preset activation opening degree.

4. The refrigeration unit control system as described in claim 1, characterized in that, The refrigeration unit control system further includes a first electronic expansion valve, a third electronic expansion valve, a fifth solenoid valve, a sixth solenoid valve, a seventh solenoid valve, and an eighth solenoid valve; wherein: The fifth solenoid valve is connected between the exhaust port of the compressor and the condenser; The first output terminal of the liquid reservoir is connected to the evaporator in sequence through the sixth solenoid valve and the third electronic expansion valve; The seventh solenoid valve is connected between the second output terminal of the liquid reservoir and the first terminal of the first electronic expansion valve, and the second terminal of the first electronic expansion valve is connected to the nozzle of the ejector. The eighth solenoid valve is connected between the exhaust port of the compressor and the first end of the first electronic expansion valve; wherein: In the heat preservation mode, the fifth solenoid valve, the condenser, the liquid receiver, the sixth solenoid valve, the third electronic expansion valve, the evaporator, the third solenoid valve, the ejector, and the gas-liquid separator constitute a refrigerant circuit, and the eighth solenoid valve is closed.

5. A refrigeration unit control method, characterized in that, The refrigeration unit control method is applied to the refrigeration unit control system as described in any one of claims 1 to 4, and the refrigeration unit control method includes: If the defrost mode is triggered, the compressor, the evaporator, and the gas-liquid separator are controlled to form a refrigerant circuit, and the exhaust port of the compressor is connected to the nozzle of the ejector, the second end of the gas-liquid separator is connected to the suction port of the ejector, and the outlet of the ejector is connected to the third end of the gas-liquid separator.

6. The refrigeration unit control method as described in claim 5, characterized in that, If the defrost mode is triggered, the refrigerant circuit consisting of the compressor, evaporator, ejector, and gas-liquid separator includes: If the defrosting mode is triggered, the first solenoid valve, the second solenoid valve, the fourth solenoid valve, the eighth solenoid valve, the first electronic expansion valve, and the second electronic expansion valve will be opened, wherein the opening degree of the second electronic expansion valve is less than the preset start-up opening degree.

7. The refrigeration unit control method as described in claim 6, characterized in that, The control of the first solenoid valve, the second solenoid valve, the fourth solenoid valve, the eighth solenoid valve, the first electronic expansion valve, and the second electronic expansion valve after opening includes: Obtain the real-time liquid level inside the gas-liquid separator; The opening degrees of the first electronic expansion valve and the second electronic expansion valve are adjusted according to the real-time liquid level, wherein the opening degree of the first electronic expansion valve is positively correlated with the real-time liquid level, and the opening degree of the second electronic expansion valve is negatively correlated with the real-time liquid level.

8. The refrigeration unit control method as described in claim 5, characterized in that, The refrigeration unit control method further includes: Obtain the real-time temperature of the cooling zone and determine whether the real-time temperature is less than or equal to the target cooling temperature; If the real-time temperature is less than or equal to the target cooling temperature, the system switches to heat preservation mode, controlling the fifth solenoid valve, the sixth solenoid valve, the third electronic expansion valve, and the third solenoid valve to open, while the eighth solenoid valve closes.

9. A cold storage facility, characterized in that, The cold storage includes a refrigeration unit control system as described in any one of claims 1 to 4, and the cold storage further includes a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the computer program, when executed by the processor, implements the steps of the refrigeration unit control method as described in any one of claims 5 to 8.

10. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores a computer program that, when executed by a processor, implements the steps of the refrigeration unit control method as described in any one of claims 5 to 8.

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