Refrigeration system and control method thereof

Abstract

The present application provides a refrigeration system and a control method for adjusting the subcooling degree of the refrigerant in the refrigeration system. The refrigeration system provided by the present application includes a throttling device and a heat exchange device. The heat exchange device includes a first channel and a second channel. The throttling device is connected between the liquid storage tank and the first channel and is used to reduce the temperature of the refrigerant flowing from the liquid storage tank into the first channel. The second channel is connected between the liquid storage tank and the refrigerant pump, and heat exchange can be carried out between the second channel and the first channel. The refrigerant transfers heat to the refrigerant in the first channel in the second channel to reduce the temperature of the refrigerant flowing into the refrigerant pump. The present application reduces the temperature of the refrigerant flowing into the refrigerant pump through the throttling device and the heat exchange device, thereby increasing the subcooling degree of the refrigerant entering the refrigerant pump, avoiding cavitation of the refrigerant at the inlet of the refrigerant pump due to the sudden drop in pressure, and enabling the refrigeration system to operate stably.

Description

Technical Field

[0001] This application relates to the technical field of refrigeration equipment, and in particular to a refrigeration system and a control method thereof. Background Art

[0002] As the requirements for energy consumption in data centers are getting higher and higher, refrigerant pump technology has gradually been applied more and more widely. Especially in the working conditions of outdoor transitional weather and low-temperature weather, the energy efficiency of the refrigerant pump system has great advantages.

[0003] When the refrigerant pump runs at high speed, the saturation pressure (or saturation temperature) of the liquid refrigerant at the inlet of the refrigerant pump is low, and it is easy to cause cavitation due to the sudden drop in pressure, and the liquid refrigerant evaporates or flashes into gaseous refrigerant; the gaseous refrigerant blocks the inlet flow channel of the refrigerant pump, thus causing downtime, making it difficult for the refrigeration system using the refrigerant pump to operate stably. Summary of the Invention

[0004] This application provides a refrigeration system and a control method thereof. The refrigeration system provided by this application includes a heat exchange device, which can reduce the temperature of the refrigerant flowing into the refrigerant pump, thereby increasing the subcooling degree of the refrigerant entering the refrigerant pump, avoiding cavitation of the refrigerant at the inlet of the refrigerant pump due to the sudden drop in pressure, and enabling the refrigeration system to operate stably.

[0005] In a first aspect, this application provides a refrigeration system, including a liquid storage tank, a refrigerant pump, an evaporator, and a condenser that form a circulation loop; wherein, the refrigeration system further includes a throttling device and a heat exchange device. The inlet of the first channel is connected to the liquid storage tank. The refrigerant in the liquid storage tank has a first pressure and a first temperature, and the refrigerant in the first channel has a second pressure and a second temperature. The throttling device is connected between the liquid storage tank and the first channel, and the throttling device can reduce the pressure and temperature of the refrigerant flowing through the throttling device, so that the second pressure is less than the first pressure and the second temperature is less than the first temperature; the second channel is connected between the liquid storage tank and the refrigerant pump, and heat exchange can be carried out between the second channel and the first channel. The refrigerant in the liquid storage tank flows into the refrigerant pump through the second channel, and the refrigerant transfers heat to the refrigerant in the first channel in the second channel to reduce the temperature of the refrigerant flowing into the refrigerant pump.

[0006] This application reduces the temperature of the refrigerant flowing into the refrigerant pump through the throttling device and the heat exchange device, thereby increasing the subcooling degree of the refrigerant entering the refrigerant pump, avoiding cavitation of the refrigerant at the inlet of the refrigerant pump due to the sudden drop in pressure, and enabling the refrigeration system to operate stably.

[0007] In some implementation manners, the refrigeration system further includes a driving device. The heat exchange device includes a first channel and a second channel. The first channel is provided with an inlet and an outlet. The throttling device is connected between the liquid storage tank and the inlet of the first channel. The driving device is connected to the outlet of the first channel and the liquid storage tank for delivering the refrigerant in the first channel to the liquid storage tank.

[0008] In this implementation manner, since the second pressure is less than the first pressure, it is necessary for the driving device to deliver the refrigerant in the first channel to the liquid storage tank to prevent the refrigerant from staying in the first channel and being wasted without participating in the refrigeration cycle.

[0009] In some implementation manners, the refrigeration system further includes a compressor, and the compressor is connected between the evaporator and the condenser.

[0010] In this implementation manner, the refrigeration system jointly drives the refrigerant to circulate in the refrigeration system through the refrigerant pump and the compressor, increasing the circulation driving force of the refrigerant, thereby enhancing the refrigeration capacity to meet the refrigeration requirements of the data center at higher external temperatures. Compared with only using the compressor, the work done by the compressor is reduced, thereby reducing the energy consumption of the refrigeration system and achieving an energy-saving effect.

[0011] In some implementation manners, the driving device includes a vacuum pump, and the vacuum pump is connected between the outlet of the first channel and the liquid storage tank.

[0012] In this implementation manner, the vacuum pump is used to deliver the refrigerant in the first channel to the liquid storage tank so that there is a pressure difference between the liquid storage tank and the first channel, and the function of the driving device can be achieved. In addition, the vacuum pump has a small power and low energy consumption, thus meeting the energy consumption requirements of the refrigeration system.

[0013] In some implementation manners, the driving device includes a compressor, and the outlet of the first channel is connected to the compressor.

[0014] In this implementation manner, the compressor is used to deliver the refrigerant in the first channel to the liquid storage tank so that there is a pressure difference between the liquid storage tank and the first channel, and the function of the driving device can be achieved. In this implementation manner, the compressor is used as the driving device, thus eliminating the vacuum pump and reducing the energy consumption of the refrigeration system.

[0015] In some implementation manners, the driving device further includes a vacuum pump. The outlet of the first channel includes a first outlet and a second outlet. The vacuum pump is connected between the first outlet of the first channel and the liquid storage tank, and the second outlet of the first channel is connected to the compressor.

[0016] In this implementation, when the temperature outside the data center is relatively low, for example, under the working conditions of outdoor transitional weather and low-temperature weather, driving the refrigerant cycle through the refrigerant pump for refrigeration can meet the refrigeration demand, and the energy consumption of the refrigerant pump is small, which is conducive to meeting the low-energy consumption requirements of the data center. When the temperature outside the data center is relatively high, the refrigerant pump and the compressor can be used together to drive the refrigerant cycle, and the refrigeration capacity of the refrigeration system is better to meet the refrigeration demand of the data center under higher external temperatures. Compared with using only the compressor, the work done by the compressor is reduced, thereby reducing the energy consumption of the refrigeration system and achieving an energy-saving effect. When the compressor in the refrigeration system is running, the vacuum pump can be turned off, and at this time, the compressor serves as the driving device. When the compressor in the refrigeration system is turned off, the vacuum pump can be turned on, and at this time, the vacuum pump serves as the driving device. In addition, due to the small lift of the refrigerant pump, the pressure of the refrigerant entering the compressor through the refrigerant pump is still greater than the pressure of the refrigerant in the first channel, that is, the pressure of the refrigerant at the compressor inlet is greater than the pressure of the refrigerant in the first channel, and the refrigerant in the first channel can enter the compressor under the action of the pressure difference.

[0017] In some implementations, the refrigeration system further includes a second valve, and the second valve is connected between the outlet of the first channel and the compressor.

[0018] In this implementation, the second valve is connected between the outlet of the first channel of the heat exchange device and the compressor, and is used to control the discharge of the refrigerant in the first channel.

[0019] In some implementations, the liquid storage tank includes a liquid region and a gas region. The liquid refrigerant in the liquid storage tank is located in the liquid region, and the gaseous refrigerant in the liquid storage tank is located in the gas region. The refrigeration system further includes an intake pipe, one end of which is connected to the vacuum pump and the other end is connected to the gas region of the liquid storage tank.

[0020] In this implementation, the intake pipe is connected to the gas region of the liquid storage tank, thereby preventing the refrigerant output from the intake pipe from disturbing the liquid refrigerant in the liquid storage tank and generating bubbles, and being able to prevent cavitation of the liquid refrigerant, enabling the refrigerant pump to operate stably.

[0021] In some implementations, the throttling device uses a throttle valve or a capillary tube.

[0022] In this implementation, the throttling device effectively reduces the pressure of the refrigerant and lowers the temperature of the refrigerant by depressurizing and expanding the refrigerant from the liquid storage tank. Among them, the throttle valve and the capillary tube control the flow rate of the refrigerant by changing the throttle section or the throttle length, thereby changing the pressure and temperature of the refrigerant.

[0023] In some implementations, the heat exchange device uses a shell-and-tube heat exchanger, a double-pipe heat exchanger, or a plate heat exchanger.

[0024] In this implementation, a shell-and-tube heat exchanger (tubular heat exchanger) may include a shell and a tube bundle enclosed in the shell, and the wall surface of the tube bundle is used as the heat transfer surface for energy exchange. A double-pipe heat exchanger may include concentric circular sleeves, and two objects with a temperature difference flow in opposite or the same direction within the concentric circular sleeves to achieve the heat exchange effect. A plate heat exchanger may be formed by stacking multiple corrugated metal sheets, channels are formed on both sides of the metal sheets, and two objects with a temperature difference flow through the channels on both sides of the metal sheet respectively to exchange heat.

[0025] In some implementations, the refrigeration system further includes an expansion valve, and the expansion valve is connected between the refrigerant pump and the evaporator.

[0026] In this implementation, the expansion valve can be used to adjust the flow rate and pressure of the refrigerant to control the refrigeration effect of the refrigeration system.

[0027] In some implementations, the refrigeration system further includes a subcooling detector, and the subcooling detector is arranged at the inlet of the refrigerant pump and is used to detect the temperature and pressure of the refrigerant at the inlet of the refrigerant pump to obtain the temperature detection value and pressure detection value of the refrigerant at the inlet of the refrigerant pump.

[0028] In this implementation, the subcooling detector may include a temperature detection device and a pressure detection device, and the temperature of the refrigerant at the inlet of the refrigerant pump is detected through the temperature detection device to obtain the temperature detection value; the pressure of the refrigerant at the inlet of the refrigerant pump is detected through the pressure detection device to obtain the pressure detection value.

[0029] In some implementations, the refrigeration system further includes a control device, the control device is electrically connected to the subcooling detector, the subcooling detector can transmit the temperature detection value and the pressure detection value to the control device, and the control device can obtain the subcooling detection value of the refrigerant at the inlet of the refrigerant pump through the temperature detection value and the pressure detection value.

[0030] In this implementation, the control device can be electrically connected to a single or multiple components in the refrigeration system, so as to control the refrigeration system to implement corresponding functions.

[0031] Second aspect, the present application also provides a control method for a refrigeration system. The refrigeration system includes a liquid storage tank, a refrigerant pump, an evaporator, and a condenser that form a circulation loop; the refrigeration system further includes a heat exchange device, a throttling device, and a vacuum pump. The heat exchange device includes a first channel and a second channel. The first channel is provided with an inlet and an outlet. The inlet of the first channel is connected to the liquid storage tank. The throttling device is connected between the liquid storage tank and the inlet of the first channel. The refrigerant in the liquid storage tank has a first pressure and a first temperature, and the refrigerant in the first channel has a second pressure and a second temperature. The vacuum pump is connected to the outlet of the first channel and the liquid storage tank. The second channel is connected between the liquid storage tank and the refrigerant pump, and heat exchange can occur between the second channel and the first channel. The throttling device is a throttle valve.

[0032] In the present application, the control method includes: controlling a first portion of the refrigerant to flow from the liquid storage tank into the refrigerant pump through the second channel; obtaining a supercooling degree detection value of the refrigerant at the inlet of the refrigerant pump; if the supercooling degree detection value is less than or equal to a first supercooling degree preset value, adjusting the opening degree of the throttling device so that a second portion of the refrigerant enters the first channel from the liquid storage tank through the throttling device, and controlling the throttling device to reduce the pressure and temperature of the second portion of the refrigerant so that the second pressure is less than the first pressure and the second temperature is less than the first temperature. The second portion of the refrigerant absorbs the heat of the first portion of the refrigerant in the second channel to reduce the temperature of the first portion of the refrigerant flowing into the refrigerant pump, and controlling the vacuum pump to transport the second portion of the refrigerant in the first channel to the liquid storage tank.

[0033] The present application reduces the temperature of the refrigerant flowing into the refrigerant pump through the throttling device and the heat exchange device, thereby increasing the supercooling degree of the refrigerant entering the refrigerant pump, avoiding cavitation of the refrigerant at the inlet of the refrigerant pump due to a sudden drop in pressure, and enabling the refrigeration system to operate stably. In addition, since the second pressure is less than the first pressure, a driving device is required to transport the refrigerant in the first channel to the liquid storage tank to prevent the refrigerant from remaining in the first channel and being wasted without participating in the refrigeration cycle.

[0034] In some implementation manners, the control method further includes: if the supercooling degree detection value is greater than the first supercooling degree preset value, closing the throttling device and the vacuum pump.

[0035] In this implementation manner, when the supercooling degree detection value is greater than the first supercooling degree preset value, the throttling device and the vacuum pump are closed to avoid idling of the vacuum pump and wasting energy consumption.

[0036] In some implementation manners, the control method further includes: if the supercooling degree detection value is greater than the first supercooling degree preset value and less than or equal to a second supercooling degree preset value, obtaining the supercooling degree detection value of the refrigerant at the inlet of the refrigerant pump again after a second time period. The second supercooling degree preset value is greater than the first supercooling degree preset value; if the supercooling degree detection value is greater than the second supercooling degree preset value, closing the throttling device and the vacuum pump.

[0037] In this implementation manner, the subcooling degree detection value can be between the first subcooling degree preset value and the second subcooling degree preset value, or slightly greater than the second subcooling degree preset value, to ensure the stable operation of the refrigerant pump; and when the subcooling degree detection value is greater than the second subcooling degree preset value, the vacuum pump is turned off to reduce energy consumption.

[0038] In some implementation manners, the refrigeration system further includes a compressor, and the compressor is connected between the evaporator and the condenser.

[0039] In a third aspect, the present application further provides a control method for a refrigeration system. The refrigeration system includes a liquid storage tank, a refrigerant pump, an evaporator, a compressor, and a condenser that form a circulation loop; the refrigeration system further includes a heat exchange device and a throttling device. The heat exchange device includes a first channel and a second channel. The first channel is provided with an inlet and an outlet. The throttling device is connected between the liquid storage tank and the inlet of the first channel. The refrigerant in the liquid storage tank has a first pressure and a first temperature, and the refrigerant in the first channel has a second pressure and a second temperature. The outlet of the first channel is connected to the compressor. The second channel is connected between the liquid storage tank and the refrigerant pump, and heat exchange can be performed between the second channel and the first channel; the throttling device is a throttle valve.

[0040] In the present application, the control method includes: controlling a first part of the refrigerant to flow from the liquid storage tank through the second channel into the refrigerant pump; obtaining the subcooling degree detection value of the refrigerant at the inlet of the refrigerant pump; if the subcooling degree detection value is less than or equal to the first subcooling degree preset value, adjusting the opening degree of the throttling device so that a second part of the refrigerant enters the first channel from the liquid storage tank through the throttling device, and controlling the throttling device to reduce the pressure and temperature of the second part of the refrigerant, so that the second pressure is less than the first pressure and the second temperature is less than the first temperature. The second part of the refrigerant absorbs the heat of the first part of the refrigerant in the second channel to reduce the temperature of the first part of the refrigerant flowing into the refrigerant pump, and controlling the compressor to transport the refrigerant in the first channel to the liquid storage tank.

[0041] In the present application, the compressor is used to transport the refrigerant in the first channel to the liquid storage tank so that there is a pressure difference between the liquid storage tank and the first channel, and the function of the driving device can be realized. This implementation manner uses the compressor as the driving device, thus eliminating the vacuum pump and reducing the energy consumption of the refrigeration system.

[0042] In some implementation manners, the control method further includes: if the subcooling degree detection value is greater than the first subcooling degree preset value, closing the throttling device.

[0043] In this implementation manner, the throttling device is closed to prevent the refrigerant in the liquid storage tank from entering the first channel.

[0044] In some implementation manners, the control method further includes: if the supercooling degree detection value is greater than the first preset supercooling degree value and less than or equal to the second preset supercooling degree value, then after a second time period, the supercooling degree detection value of the refrigerant at the inlet of the refrigerant pump is obtained again, and the second preset supercooling degree value is greater than the first preset supercooling degree value; if the supercooling degree detection value is greater than the second preset supercooling degree value, the throttling device is closed.

[0045] In this implementation manner, the supercooling degree detection value can be between the first preset supercooling degree value and the second preset supercooling degree value, or slightly greater than the second preset supercooling degree value, so as to ensure the stable operation of the refrigerant pump.

[0046] In some implementation manners, adjusting the opening degree of the throttling device includes: if the throttling device is in a closed state, increasing the opening degree of the throttling device; if the throttling device is in an open state, decreasing the opening degree of the throttling device.

[0047] In this implementation manner, if the throttling device is in a closed state, increasing the opening degree of the throttling device enables the refrigerant in the liquid storage tank to enter the first channel; if the throttling device is in an open state, decreasing the opening degree of the throttling device reduces the temperature of the second part of the refrigerant, thereby increasing the supercooling degree of the refrigerant at the inlet of the refrigerant pump.

[0048] In some implementation manners, the control method further includes: if the supercooling degree detection value is less than or equal to the first preset supercooling degree value, then after a first time period, the supercooling degree detection value is obtained again.

[0049] In this implementation manner, after the vacuum pump is turned on and the opening degree of the throttling device is adjusted, it takes a certain amount of time for the supercooling degree of the refrigerant to reach a stable state. Detecting the supercooling degree of the refrigerant at the inlet of the refrigerant pump again after the first time period can enable detection when the supercooling degree of the refrigerant at the inlet of the refrigerant pump reaches a stable state, thereby improving the accuracy of the supercooling degree detection value and further improving the control precision of the control device for the supercooling degree. Description of the Drawings

[0050] Figure 1 is a schematic diagram of a refrigeration system provided by an embodiment of the present application;

[0051] Figure 2 is a kind of Figure 1 flow schematic diagram of the control method of the refrigeration system shown;

[0052] Figure 3 is a schematic diagram of the refrigeration system provided by the present application in some other embodiments;

[0053] Figure 4 is a schematic diagram of the refrigeration system provided by the present application in some other embodiments;

[0054] Figure 5 is a schematic flow chart of a control method for a refrigeration system provided in an embodiment of the present application; Figure 4

[0055] Figure 6 is provided by the present application Figure 4 schematic flow chart of the control method for the refrigeration system shown in some other embodiments;

[0056] Figure 7 is a schematic diagram of the refrigeration system provided by the present application in still some other embodiments. Detailed implementation manners

[0057] Please refer to Figure 1 , Figure 1 is a schematic diagram of a refrigeration system 100 provided in an embodiment of the present application.

[0058] In the first embodiment, the refrigeration system 100 may include a condenser 1, a liquid storage tank 2, a heat exchange device 3, a driving device 4, a refrigerant pump 5, an evaporator 6, a compressor 7, and a throttling device 8 that form a circulation loop. In the present application, the refrigeration system 100 may be used to lower the temperature of a data center. The refrigeration system 100 may use a refrigerant as a working medium, utilize the reversible phase change of the refrigerant for energy transfer, transfer the heat of the data center, and thus lower the temperature of the data center. Exemplarily, the refrigerant may adopt partial halogenated hydrocarbons, such as chlorofluorocarbons. In some other embodiments, the refrigerant may also adopt ammonia, sulfur dioxide, and non-halogenated hydrocarbons, such as methane, etc.

[0059] Among them, the liquid storage tank 2 is used to store the refrigerant and ensure the continuous liquid supply of the refrigeration system 100. The liquid storage tank 2 can also prevent the cavitation of the refrigerant pump 5; specifically, the liquid storage tank 2 may be disposed above the refrigerant pump 5 so that there may be a pressure difference between the liquid storage tank 2 and the refrigerant pump 5, thereby increasing the pressure of the refrigerant entering the refrigerant pump 5 from the liquid storage tank 2 and preventing the cavitation of the refrigerant pump 5.

[0060] ​Exemplarily, the liquid storage tank 2 has an inlet 21, an outlet 22, a bypass inlet 23 and a bypass outlet 24. The inlet 21 and the outlet 22 are respectively located at both ends of the liquid storage tank 2, and both the bypass inlet 23 and the bypass outlet 24 are located between the inlet 21 and the outlet 22. Exemplarily, the liquid storage tank 2 includes a liquid region 92 and a gas region 91. When all the liquid refrigerant circulating in the refrigeration system 100 is filled into the liquid storage tank 2, the occupied region is the liquid region 92 of the liquid storage tank 2. Among them, the liquid region 92 is located at the lower side of the liquid storage tank 2, and the gas region 91 is located at the upper side of the liquid storage tank 2. The refrigerant located in the liquid storage tank 2 includes gaseous refrigerant and liquid refrigerant. The liquid refrigerant is all located in the liquid region 92, and the gaseous refrigerant can be located in the gas region 91. In this application, the end of the liquid storage tank 2 close to the outlet 22 is the "lower side", and the end close to the inlet 21 is the "upper side". Among them, the orientation terms mentioned in the embodiments of this application, such as "upper" and "lower", are only with reference to the direction of the attached drawings. Therefore, the orientation terms used are for better and clearer explanation and understanding of the embodiments of this application, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus cannot be understood as a limitation to the embodiments of this application.

[0061] Among them, the refrigerant pump 5 is connected to the outlet 22 of the liquid storage tank 2 and is used to increase the pressure from the liquid storage tank 2 so that the refrigerant can overcome the resistance of the refrigeration system 100 and circulate in the refrigeration system 100, playing a role in transferring energy. The refrigerant pump 5 can also be called a refrigerant pump. Exemplarily, the refrigerant pump 5 can adopt a positive displacement gear pump or a dynamic centrifugal pump. The dynamic centrifugal pump has obvious advantages in terms of service life, and in the scenarios of large flow rate and small head, the centrifugal pump also has better operating efficiency. This application takes the refrigerant pump 5 adopting a centrifugal pump as an example for illustration. In some other embodiments, the refrigerant pump 5 can also adopt other pumps to drive the refrigerant to circulate, and this application does not make any limitation thereto.

[0062] Among them, the heat exchange device 3 is connected between the liquid storage tank 2 and the refrigerant pump 5. In this application, the pressure inside the refrigerant pump 5 decreases to suck in the liquid. Exemplarily, the centrifugal pump makes the liquid entering the centrifugal pump undergo centrifugal motion by the rotation of the impeller to increase the pressure of the liquid. When the liquid entering the centrifugal pump is thrown from the middle of the impeller to the periphery, a low-pressure area will be formed in the middle of the impeller, that is, the pressure in the middle of the impeller decreases to suck in the liquid. The refrigerant in the refrigerant pump 5 evaporates or flashes from liquid to gas due to the sudden drop in pressure, that is, cavitation occurs. The gaseous refrigerant blocks the inlet flow passage of the centrifugal pump, thus causing the shutdown of the machine. This application reduces the temperature of the refrigerant flowing from the outlet 22 of the liquid storage tank 2 into the refrigerant pump 5 through the heat exchange device 3, thereby increasing the subcooling degree of the refrigerant entering the refrigerant pump 5, avoiding cavitation of the refrigerant in the refrigerant pump 5 due to the sudden drop in pressure, and enabling the refrigeration system 100 to operate stably.

[0063] Exemplarily, the heat exchange device 3 may include a first channel 31 and a second channel 32. The first channel 31 is provided with an inlet 311 and an outlet 312, and the inlet 311 of the first channel 31 is connected to the liquid storage tank 2. The refrigerant in the liquid storage tank 2 has a first pressure and a first temperature, and the refrigerant in the first channel 31 has a second pressure and a second temperature. The throttling device 8 is connected between the liquid storage tank 2 and the inlet 311 of the first channel 31, that is, the throttling device 8 is connected between the liquid storage tank 2 and the first channel 31. The throttling device 8 can reduce the pressure and temperature of the refrigerant flowing through the throttling device 8, so that the second pressure is less than the first pressure and the second temperature is less than the first temperature. The second channel 32 is connected between the liquid storage tank 2 and the refrigerant pump 5, and heat exchange can be carried out between the second channel 32 and the first channel 31. The refrigerant in the liquid storage tank 2 flows into the refrigerant pump 5 through the second channel 32, and the refrigerant transfers heat to the refrigerant in the first channel 31 in the second channel 32 to reduce the temperature of the refrigerant flowing into the refrigerant pump 5, thereby increasing the subcooling degree of the refrigerant flowing into the refrigerant pump 5. It can be understood that the refrigerant in the first channel 31 can be all gaseous refrigerant, can also include liquid refrigerant and gaseous refrigerant, or can be all liquid refrigerant. This application does not make a limitation on this. In addition, the refrigerant with the second pressure has a saturation temperature. In this application, the absolute value of the difference between the saturation temperature and the second temperature, that is, the absolute value of the difference between the saturation temperature minus the second temperature, is the subcooling degree of the refrigerant.

[0064] This application reduces the temperature of the refrigerant flowing into the refrigerant pump 5 through the throttling device 8 and the heat exchange device 3, thereby increasing the subcooling degree of the refrigerant entering the refrigerant pump 5, avoiding cavitation of the refrigerant at the inlet of the refrigerant pump 5 due to the sudden drop in pressure, and enabling the refrigeration system 100 to operate stably.

[0065] Among them, the throttling device 8 is connected between the liquid storage tank 2 and the inlet 311 of the first channel 31 of the heat exchange device 3, and is used to control the entry of the refrigerant into the first channel 31, and is also used to reduce the temperature of the refrigerant flowing from the liquid storage tank 2 into the first channel 31, that is, to reduce the first temperature. The throttling device 8 effectively reduces the pressure and temperature of the refrigerant by depressurizing and expanding the refrigerant from the liquid storage tank 2, so that the temperature of the refrigerant in the first channel 31 is lower than the temperature of the refrigerant in the liquid storage tank 2, that is, the second temperature is lower than the first temperature. The throttling device 8 can adopt a throttle valve or a capillary tube. The throttle valve and the capillary tube control the flow rate of the refrigerant by changing the throttling section or the throttling length, thereby changing the pressure and temperature of the refrigerant.

[0066] Among them, the driving device 4 is connected to the outlet 312 of the first channel 31 and the liquid storage tank 2, and is used to transport the refrigerant in the first channel 31 to the liquid storage tank 2. Since the second pressure is less than the first pressure, it is necessary to use the driving device 4 to transport the refrigerant in the first channel 31 to the liquid storage tank 2, so as to prevent the refrigerant from staying in the first channel 31 and being wasted without participating in the refrigeration cycle. In some other embodiments, the refrigeration system 100 may not include the driving device 4, and the present application does not limit this.

[0067] Exemplarily, the driving device 4 may include a vacuum pump 41. The vacuum pump 41 has a small power and low energy consumption, thus meeting the energy consumption requirements of the refrigeration system 100. Among them, the vacuum pump 41 is connected between the outlet 312 of the first channel 31 and the liquid storage tank 2, and is used to transport the refrigerant in the first channel 31 to the liquid storage tank 2.

[0068] Among them, the evaporator 6 is used to enable the refrigerant to exchange heat with the air in the data center to achieve a refrigeration effect. The liquid refrigerant vaporizes and absorbs heat after passing through the evaporator 6 and becomes a gaseous refrigerant.

[0069] Among them, the compressor 7 is connected between the evaporator 6 and the condenser 1, and is used to increase the pressure and temperature of the gaseous refrigerant from the evaporator 6, thereby increasing the driving force for the refrigerant to circulate in the refrigeration system 100 to meet the power demand for the circulation of the refrigeration system 100.

[0070] Among them, the condenser 1 is used to dissipate the heat of the gaseous refrigerant, so that the gaseous refrigerant condenses into a liquid refrigerant.

[0071] As Figure 1 shown, the outlet 22 of the liquid storage tank 2 is connected to the heat exchange device 3, the heat exchange device 3 is connected to the inlet of the refrigerant pump 5, the outlet of the refrigerant pump 5 is sequentially connected to the evaporator 6, the compressor 7 and the condenser 1, and the condenser 1 is connected to the inlet 21 of the liquid storage tank 2 to form a circulation loop of the refrigeration system 100. In the present application, the refrigerant performs a refrigeration cycle along the circulation loop of the refrigeration system 100 under the drive of the refrigerant pump 5, taking away the heat of the air in the data center, thereby reducing the temperature at the data center to achieve a refrigeration effect. When the refrigeration system 100 performs a refrigeration cycle, the liquid refrigerant in the liquid storage tank 2 flows into the refrigerant pump 5 after being cooled by the throttling device 8 and the heat exchange device 3, and enters the evaporator 6 after being pressurized by the refrigerant pump 5. The liquid refrigerant absorbs the heat of the air in the data center at the evaporator 6 and becomes a gaseous refrigerant to take away the heat of the data center to achieve a refrigeration effect. The gaseous refrigerant enters the condenser 1 after being pressurized by the compressor 7, and releases the heat of the data center carried by it through the condenser 1 and condenses into a liquid refrigerant. The liquid refrigerant returns to the liquid storage tank 2 from the condenser 1 to complete a refrigeration cycle.

[0072] In the first embodiment, the refrigeration system 100 drives the refrigerant to circulate within the refrigeration system 100 through the combined action of the refrigerant pump 5 and the compressor 7, increasing the driving force for the refrigerant circulation, thereby enhancing the refrigeration capacity of the refrigeration system 100 to meet the refrigeration requirements of the data center at higher external temperatures. In addition, compared with only using the compressor 7, the work done by the compressor 7 is reduced, thereby lowering the energy consumption of the refrigeration system 100 and achieving an energy-saving effect. Exemplarily, the refrigeration system 100 may further include an expansion valve (not shown in the figure) (which may also be referred to as a throttle valve), and the expansion valve may be connected between the refrigerant pump 5 and the evaporator 6 for regulating the flow rate and pressure of the refrigerant to control the refrigeration effect of the refrigeration system 100.

[0073] Exemplarily, the heat exchange device 3 may employ a shell-and-tube heat exchanger (tubular heat exchanger), a double-pipe heat exchanger, or a plate heat exchanger. The shell-and-tube heat exchanger (tubular heat exchanger) may include a shell and a tube bundle enclosed in the shell, and the wall surface of the tube bundle is used as the heat transfer surface for energy exchange. The double-pipe heat exchanger may include concentric circular tubes, and two substances with a temperature difference flow in opposite or the same direction within the concentric circular tubes to achieve a heat exchange effect. The plate heat exchanger may be formed by stacking multiple corrugated metal sheets, and channels are formed on both sides of the metal sheets. Two substances with a temperature difference flow through the channels on both sides of the metal sheets respectively to conduct heat exchange. The specific structures of the shell-and-tube heat exchanger (tubular heat exchanger), or the double-pipe heat exchanger, or the plate heat exchanger may refer to the prior art and will not be elaborated herein.

[0074] Exemplarily, the first channel 31 and / or the second channel 32 of the heat exchange device 3 may include a plurality of pipes arranged at intervals to increase the contact area between the refrigerant in the first channel 31 and the refrigerant in the second channel 32, thereby enhancing the heat exchange efficiency between the two and effectively reducing the temperature of the refrigerant entering the refrigerant pump 5 from the second channel 32. Exemplarily, the heat exchange device 3 may adopt a metal material such as copper or copper alloy. The metal material such as copper or copper alloy has good thermal conductivity and can enhance the heat exchange efficiency between the gaseous refrigerant in the first channel 31 and the refrigerant liquid in the second channel 32. In some other embodiments, the heat exchange device 3 may also adopt other non-metal materials with good thermal conductivity, such as heat-conducting rubber containing carbon materials, etc., and the present application does not make any limitations in this regard.

[0075] Exemplarily, the inlet 311 of the first channel 31 of the heat exchange device 3 may be connected to the bypass outlet 24 of the liquid storage tank 2, and the outlet 312 of the first channel 31 of the heat exchange device 3 may be connected to the bypass inlet 23 of the liquid storage tank 2. The bypass outlet 24 of the liquid storage tank 2 may be connected to the liquid region 92 of the liquid storage tank 2, may also be connected to the gas region 91, or may be connected to both the liquid region 92 and the gas region 91 at the same time; the bypass inlet 23 of the liquid storage tank 2 may be connected to the liquid region 92, may also be connected to the gas region 91, or may be connected to both the liquid region 92 and the gas region 91 at the same time; the present application does not make any limitation thereto.

[0076] Exemplarily, as Figure 1 shown, the bypass outlet 24 of the liquid storage tank 2 may be connected to the gas region 91. At this time, the gaseous refrigerant in the liquid storage tank 2 enters the first channel 31 under the action of the pressure difference, and after exchanging heat with the refrigerant in the second channel 32, the gaseous refrigerant in the liquid storage tank 2 is sucked out of the first channel 31 by the vacuum pump 41 and returns to the liquid storage tank 2 from the bypass inlet 23 of the liquid storage tank 2.

[0077] Exemplarily, the driving device 4 may further include an intake pipe 42. One end of the intake pipe 42 is connected to the vacuum pump 41, and the other end of the intake pipe 42 is connected to the gas region 91 of the liquid storage tank 2, that is, the lower end of the intake pipe 42 is connected to the vacuum pump 41, and the upper end of the intake pipe 42 is connected to the gas region 91 of the liquid storage tank 2, so as to avoid generating bubbles in the liquid refrigerant in the liquid storage tank 2 by the gaseous refrigerant output from the intake pipe 42, and to avoid cavitation of the liquid refrigerant, so that the refrigerant pump 5 can operate stably.

[0078] In some other embodiments, a liquid level detector may also be provided in the liquid storage tank 2 to detect the height of the liquid level of the liquid refrigerant in the liquid storage tank 2. When it is detected that the liquid level of the liquid refrigerant in the liquid storage tank 2 is close to or higher than the upper end of the intake pipe 42, the flow rate of the refrigerant is adjusted by the refrigerant pump 5 to ensure that the upper end of the intake pipe 42 is located on the upper side of the liquid level of the refrigerant. In addition, the upper end of the intake pipe 42 may also be connected to the liquid region 91, and the present application does not make any limitation thereto.

[0079] In some other embodiments, the driving device 4 may not be provided with the intake pipe 42. At this time, the bypass inlet 23 of the liquid storage tank 2 may be connected to the gas region 91 of the liquid storage tank 2 to avoid contact between the gaseous refrigerant input from the bypass inlet 23 and the liquid refrigerant in the liquid storage tank 2, so as to avoid disturbing the liquid refrigerant in the liquid storage tank 2 by the refrigerant output from the intake pipe 42 and generating bubbles, thereby being able to avoid cavitation of the liquid refrigerant and enabling the refrigerant pump 5 to operate stably. In some other embodiments, the bypass inlet 23 may also be connected to the liquid region 92 of the liquid storage tank 2, and the present application does not make any limitation thereto.

[0080] Exemplarily, the refrigeration system 100 may further be provided with a subcooling degree detector and a control device. Among them, the subcooling degree detector (not shown in the figure) is arranged at the inlet of the refrigerant pump 5 and is used to detect the temperature and pressure of the refrigerant at the inlet of the refrigerant pump 5 to obtain the temperature detection value and pressure detection value of the refrigerant at the inlet of the refrigerant pump 5. Exemplarily, the subcooling degree detector may include a temperature detection device and a pressure detection device, and detect the temperature of the refrigerant at the inlet of the refrigerant pump 5 through the temperature detection device and detect the pressure of the refrigerant at the inlet of the refrigerant pump 5 through the pressure detection device. In some other embodiments, the subcooling degree detector may adopt other detection devices as long as the temperature detection value and pressure detection value of the refrigerant at the inlet of the refrigerant pump 5 can be obtained. In some other embodiments, the subcooling degree detector may further obtain the subcooling degree detection value of the refrigerant at the inlet of the refrigerant pump 5 according to the temperature detection value and pressure detection value. For example, the subcooling degree detector may include a processing device, and the processing device can calculate the temperature detection value and pressure detection value according to the existing program to obtain the subcooling degree detection value of the refrigerant.

[0081] Among them, the control device (not shown in the figure) may be electrically connected to a single or multiple components in the refrigeration system 100, so as to control the refrigeration system 100 to implement corresponding functions. For example, the control device may be electrically connected to the subcooling degree detector and is used to receive the temperature detection value and pressure detection value from the subcooling degree detector, and obtain the subcooling degree detection value of the refrigerant at the inlet of the refrigerant pump 5 according to the temperature detection value and pressure detection value. In some other embodiments, the control device may further receive the subcooling degree detection value from the subcooling degree detector. Exemplarily, the control device is further used to control the refrigeration system 100 according to the subcooling degree detection value of the refrigerant at the inlet of the refrigerant pump 5, such as adjusting the opening degree of the throttling device 8 and turning on or off the driving device 4, so as to adjust the subcooling degree of the refrigerant at the inlet of the refrigerant pump 5. The method for the control device to control the refrigeration system 100 to adjust the subcooling degree of the refrigerant will be described later.

[0082] Please refer to Figure 1 and Figure 2 , Figure 2 which is a schematic flow chart of a control method for a Figure 1 refrigeration system 100 provided by an embodiment of the present application. Figure 2 The control method shown is used to adjust the subcooling degree of the refrigerant in the refrigeration system 100.

[0083] Exemplarily, the control method of the refrigeration system 100 may include:

[0084] Step S1: Control the first part of the refrigerant to flow from the liquid storage tank 2 into the refrigerant pump 5 through the second channel 32. Understandably, the refrigerant flowing from the outlet 22 of the liquid storage tank 2 into the second channel 32 is the first part of the refrigerant, and the refrigerant flowing from the bypass outlet 24 of the liquid storage tank 2 into the first channel 31 is the second part of the refrigerant. In this application, the refrigerant in the first channel 31 is named "the second part of the refrigerant", and the refrigerant in the second channel 32 is named "the first part of the refrigerant" to distinguish the refrigerant in the first channel 31 from the refrigerant in the second channel 32, so as to more clearly illustrate the control method of the refrigeration system 100, and it should not be construed as a special limitation on the refrigerant in the refrigeration system 100.

[0085] Step S2: Obtain the supercooling degree detection value of the refrigerant at the inlet of the refrigerant pump 5;

[0086] Step S3: Determine whether the supercooling degree detection value is less than or equal to the first supercooling degree preset value;

[0087] If the supercooling degree detection value is less than or equal to the first supercooling degree preset value, adjust the opening degree of the throttling device 8 so that the second part of the refrigerant enters the first channel 31 from the liquid storage tank 2 through the throttling device 8, and control the throttling device 8 to reduce the pressure and temperature of the second part of the refrigerant, so that the second pressure is less than the first pressure and the second temperature is less than the first temperature. The second part of the refrigerant absorbs the heat of the first part of the refrigerant in the second channel 32 to reduce the temperature of the first part of the refrigerant flowing into the refrigerant pump 5, and control the vacuum pump 41 to transport the refrigerant in the first channel 31 to the liquid storage tank 2.

[0088] Exemplarily, step S3 may further include: if the supercooling degree detection value is greater than the first supercooling degree preset value, close the throttling device 8 and the vacuum pump 41.

[0089] Exemplarily, step S3 may further include: if the supercooling degree detection value is less than or equal to the first supercooling degree preset value, obtain the supercooling degree detection value of the refrigerant at the inlet of the refrigerant pump 5 again after the first time period, and so on until the supercooling degree detection value is greater than the first supercooling degree preset value. In this embodiment, after the vacuum pump 41 is turned on and the opening degree of the throttling device 8 is adjusted, the supercooling degree of the refrigerant takes a certain time to reach a stable state. Detecting the supercooling degree of the refrigerant at the inlet of the refrigerant pump 5 again after the first time period can enable detection when the supercooling degree of the refrigerant at the inlet of the refrigerant pump 5 reaches a stable state, thereby improving the accuracy of the supercooling degree detection value and further improving the control precision of the control device for the supercooling degree.

[0090] Exemplarily, the first supercooling degree preset value may be in the range of 1° to 1.5°, for example, 1°.

[0091] Exemplarily, the first time period can be in the range of 10 seconds to 30 seconds. For example, the first time period can be 10 seconds, 15 seconds, 25 seconds, etc. The length of the first time period can be adjusted according to requirements, and the present application does not limit this.

[0092] Exemplarily, the control method of the refrigeration system 100 may further include:

[0093] Step S4: If the supercooling degree detection value is greater than the first supercooling degree preset value, then determine whether the supercooling degree detection value is less than or equal to the second supercooling degree preset value;

[0094] If the supercooling degree detection value is greater than the first supercooling degree preset value and less than or equal to the second supercooling degree preset value, then after a second time period, the supercooling degree detection value of the refrigerant at the inlet of the refrigerant pump 5 is obtained again, and this is cycled until the supercooling degree detection value is greater than the second supercooling degree preset value.

[0095] Exemplarily, step S4 may further include: if the supercooling degree detection value is greater than the second supercooling degree preset value, then close the throttling device 8 and the vacuum pump 41.

[0096] In this embodiment, the supercooling degree detection value can be between the first supercooling degree preset value and the second supercooling degree preset value, or slightly greater than the second supercooling degree preset value to ensure the stable operation of the refrigerant pump 5; and when the supercooling degree detection value is greater than the second supercooling degree preset value, the vacuum pump 41 is closed to reduce energy consumption.

[0097] Exemplarily, the second supercooling degree preset value is greater than the first supercooling degree preset value. The second supercooling degree preset value can be in the range of 3.5° to 4.5°, for example 4°.

[0098] Exemplarily, the second time period can be in the range of 10 seconds to 60 seconds. For example, the second time period can be 10 seconds, 30 seconds, 45 seconds, etc. The second time period can be equal to the first time period or not equal to the first time period, and the present application does not limit this. In this embodiment, after the vacuum pump 41 is turned on and the opening degree of the throttling device 8 is adjusted, it takes a certain time for the supercooling degree of the refrigerant to reach a stable state. After the second time period, the supercooling degree of the refrigerant at the inlet of the refrigerant pump 5 is detected again, which can enable the detection to be performed when the supercooling degree of the refrigerant at the inlet of the refrigerant pump 5 reaches a stable state, thereby improving the accuracy of the supercooling degree detection value and further improving the control accuracy of the control device for the supercooling degree.

[0099] Exemplarily, the throttling device 8 of the refrigeration system 100 can be a throttle valve.

[0100] Among them, the specific steps of adjusting the opening degree of the throttling device 8 in step S3 and / or step S4 may include:

[0101] Determine whether the throttling device 8 is in a closed state;

[0102] If the throttling device 8 is in a closed state, increase the opening degree of the throttling device 8; if the throttling device 8 is in an open state, decrease the opening degree of the throttling device 8 to increase the subcooling degree of the refrigerant at the inlet of the refrigerant pump 5.

[0103] Among them, when the throttling device 8 is in a closed state, that is, the opening degree of the throttling device 8 is 0%; increasing the opening degree of the throttling device 8, that is, opening the throttling device 8, so that the second part of the refrigerant enters the first channel 31 through the throttling device 8 from the liquid storage tank 2. When the throttling device 8 is in an open state, that is, the opening degree of the throttling device 8 is greater than 0%, it can cause the refrigerant flowing through the throttling device 8 to depressurize and expand, effectively reducing the pressure of the refrigerant and lowering the temperature of the refrigerant, achieving the effect of increasing the subcooling degree of the refrigerant at the inlet of the refrigerant pump 5. It can be understood that when the opening degree of the throttling device 8 is 100% or 0%, the pressure difference between the inlet and outlet of the throttling device 8 is close to 0, that is, the pressure and temperature of the refrigerant flowing through the throttling device 8 hardly change. When the opening degree of the throttling device 8 is greater than 0% and less than 100%, there is a pressure difference between the inlet and outlet of the throttling device 8, so that the refrigerant flowing through the throttling device 8 can depressurize and expand, effectively reducing the pressure of the refrigerant and lowering the temperature of the refrigerant.

[0104] In addition, reducing the opening degree of the throttling device 8 can further increase the subcooling degree of the refrigerant at the inlet of the refrigerant pump 5 and improve the operating stability of the refrigerant pump. It can be understood that the smaller the opening degree of the throttling device 8, the greater the pressure difference between the inlet and outlet of the throttling device 8, that is, the greater the pressure drop of the refrigerant flowing through the throttling device 8 and the greater the temperature difference. Reducing the opening degree of the throttling device 8 can increase the pressure drop and temperature difference of the refrigerant flowing through the throttling device 8, thereby further reducing the second temperature of the refrigerant in the first channel 31 and further increasing the subcooling degree of the refrigerant at the inlet of the refrigerant pump 5.

[0105] Exemplarily, the control device can be electrically connected to the throttling device 8 and the vacuum pump 41, and the control device can achieve Figure 2 the shown control method by controlling the throttling device 8 and the vacuum pump 41. In some other embodiments, the control method shown can also be achieved by the user independently controlling the throttling device 8 and the vacuum pump 41. Figure 2 This application does not make any limitation thereto.

[0106] Exemplarily, the specific process of obtaining the subcooling degree detection value of the refrigerant at the inlet of the refrigerant pump 5 in step S1 may include:

[0107] The subcooling detector detects the temperature and pressure of the refrigerant at the inlet of the refrigerant pump 5, obtains the temperature detection value and the pressure detection value, and transmits the measured temperature detection value and pressure detection value to the control device; the control device calculates the subcooling detection value according to the temperature detection value and the pressure detection value.

[0108] In some other embodiments, the specific process of obtaining the subcooling detection value of the refrigerant at the inlet of the refrigerant pump 5 in step S1 may further include:

[0109] The subcooling detector detects the temperature and pressure of the refrigerant at the inlet of the refrigerant pump 5, obtains the temperature detection value and the pressure detection value, obtains the subcooling detection value according to the measured temperature detection value and pressure detection value, and transmits the subcooling detection value to the control device.

[0110] Please refer to Figure 3 , Figure 3 which is a schematic diagram of the refrigeration system 100a provided in the present application in some other embodiments.

[0111] In the second embodiment, the refrigeration system 100a may include a condenser 1a, a liquid storage tank 2a, a heat exchange device 3a, a driving device 4a, a refrigerant pump 5a, an evaporator 6a, and a throttling device 8a that form a circulation loop. Among them, the heat exchange device 3a is connected between the liquid storage tank 2a and the refrigerant pump 5a. The heat exchange device 3a may include a first channel 31a and a second channel 32a. The first channel 31a is provided with an inlet 311a and an outlet 312a, and the inlet 311a of the first channel 31a is connected to the liquid storage tank 2a. The refrigerant in the liquid storage tank 2a has a first pressure and a first temperature, and the refrigerant in the first channel 31a has a second pressure and a second temperature. The throttling device 8a is connected between the liquid storage tank 2a and the inlet 311a of the first channel 31a. The throttling device 8a can reduce the pressure and temperature of the refrigerant flowing through the throttling device 8a, so that the second pressure is less than the first pressure and the second temperature is less than the first temperature. The driving device 4a is connected to the outlet 312a of the first channel 31a and the liquid storage tank 2a, and is used to transport the refrigerant in the first channel 31a to the liquid storage tank 2a. The second channel 32a is connected between the liquid storage tank 2a and the refrigerant pump 5a, and heat exchange can be performed between the second channel 32a and the first channel 31a. The refrigerant in the liquid storage tank 2a flows into the refrigerant pump 5a through the second channel 32a, and the refrigerant transfers heat to the refrigerant in the first channel 31a in the second channel 32a to reduce the temperature of the refrigerant flowing into the refrigerant pump 5a, thereby increasing the subcooling degree of the refrigerant flowing into the refrigerant pump 5a. The driving device 4a may adopt a vacuum pump 41a. In some other embodiments, the refrigeration system 100a may also not include the driving device 4a, and the present application does not limit this.

[0112] Exemplarily, the refrigeration system 100a may further include a subcooling degree detector and a control device. The subcooling degree detector (not shown in the figure) is disposed at the inlet of the refrigerant pump 5a and is used to detect the temperature and pressure of the refrigerant at the inlet of the refrigerant pump 5a, so as to obtain the temperature detection value and pressure detection value of the refrigerant at the inlet of the refrigerant pump 5a. The control device (not shown in the figure) may be electrically connected to the throttling device 8a, the vacuum pump 41a, and the subcooling degree detector, and is used to receive the temperature detection value and pressure detection value from the subcooling degree detector, and obtain the subcooling degree detection value of the refrigerant at the inlet of the refrigerant pump 5a according to the temperature detection value and pressure detection value. The control device is further used to control the refrigeration system 100a according to the subcooling degree detection value of the refrigerant at the inlet of the refrigerant pump 5a, for example, adjust the opening degree of the throttling device 8a, and turn on or off the vacuum pump 41a, so as to adjust the subcooling degree of the refrigerant at the inlet of the refrigerant pump 5a.

[0113] It can be understood that the multiple devices included in the refrigeration system 100a in the second embodiment and the connections between the multiple devices may refer to the refrigeration system 100 in the first embodiment, and only the differences between the two are described herein. It should be understood that in the embodiments of the present application, when one component is designed with reference to another component, the structures of the two components may be completely the same, or the core structures of the two components may be the same, and there may be slight differences in a small amount of structures. The present application does not make strict limitations on this.

[0114] As Figure 3 shown, in the second embodiment, the refrigeration system 100a drives the refrigerant to circulate in the refrigeration system 100a through the refrigerant pump 5a to provide a refrigeration effect for the data center. When the temperature outside the data center is relatively low, for example, under the working conditions of outdoor transitional weather and low-temperature weather, driving the refrigerant to circulate through the refrigerant pump 5a for refrigeration can meet the refrigeration requirements, and the energy consumption of the refrigerant pump 5a is small, which is beneficial to meeting the low-energy consumption requirements of the data center. As Figure 1 shown, in the first embodiment, when the temperature outside the data center is relatively high, the refrigerant pump 5 and the compressor 7 can be used to drive the refrigerant to circulate, increasing the circulation driving force of the refrigerant, thereby enhancing the refrigeration capacity of the refrigeration system 100 to meet the refrigeration requirements of the data center under higher external temperatures. In addition, compared with only using the compressor 7, the work done by the compressor 7 is reduced, thereby reducing the energy consumption of the refrigeration system 100 and achieving an energy-saving effect.

[0115] Please refer to Figure 2 and Figure 3 , Figure 2 shown, the control method can also be used to adjust the subcooling degree of the refrigerant in the refrigeration system 100a shown in Figure 3 , which will not be elaborated herein.

[0116] Please refer to Figure 4 ,Figure 4 It is a schematic diagram of the refrigeration system 100b provided by the present application in some other embodiments.

[0117] In the third embodiment, the refrigeration system 100b may include a condenser 1b, a liquid storage tank 2b, a heat exchange device 3b, a driving device 4b, a refrigerant pump 5b, an evaporator 6b, a compressor 7b, and a throttling device 8b that form a circulation loop. Among them, the heat exchange device 3b is connected between the liquid storage tank 2b and the refrigerant pump 5b. The heat exchange device 3b may include a first channel 31b and a second channel 32b. The first channel 31b is provided with an inlet 311b and an outlet 312b, and the inlet 311b of the first channel 31b is connected to the liquid storage tank 2b. The refrigerant in the liquid storage tank 2b has a first pressure and a first temperature, and the refrigerant in the first channel 31b has a second pressure and a second temperature. The throttling device 8b is connected between the liquid storage tank 2b and the inlet 311b of the first channel 31b. The throttling device 8b can reduce the pressure and temperature of the refrigerant flowing through the throttling device 8b, so that the second pressure is less than the first pressure and the second temperature is less than the first temperature. The driving device 4b is connected to the outlet 312b of the first channel 31b and the liquid storage tank 2b, and is used to transport the refrigerant in the first channel 31b to the liquid storage tank 2b. The second channel 32b is connected between the liquid storage tank 2b and the refrigerant pump 5b, and heat exchange can be carried out between the second channel 32b and the first channel 31b. The refrigerant in the liquid storage tank 2b flows into the refrigerant pump 5b through the second channel 32b, and the refrigerant transfers heat to the refrigerant in the first channel 31b in the second channel 32b to reduce the temperature of the refrigerant flowing into the refrigerant pump 5b, thereby increasing the subcooling degree of the refrigerant flowing into the refrigerant pump 5b. In some other embodiments, the refrigeration system 100b may also not include the driving device 4b, and the present application does not limit this.

[0118] It can be understood that the multiple devices included in the refrigeration system 100b in the third embodiment and the connections between the multiple devices can refer to the refrigeration system 100 in the first embodiment, and only the differences between the two will be described here.

[0119] In the third embodiment, the driving device 4b may include the compressor 7b. The outlet 312b of the first channel 31b is connected to the compressor 7b. The compressor 7b is used to transport the refrigerant in the first channel 31b to the liquid storage tank 2b, and can realize the function of the driving device 4b. This embodiment can use the compressor 7b as the driving device 4b, thereby eliminating the vacuum pump and reducing the energy consumption of the refrigeration system 100b.

[0120] Exemplarily, the refrigeration system 100b may further include a subcooling degree detector and a control device. The subcooling degree detector (not shown in the figure) is disposed at the inlet of the refrigerant pump 5b and is used to detect the temperature and pressure of the refrigerant at the inlet of the refrigerant pump 5b, so as to obtain the temperature detection value and pressure detection value of the refrigerant at the inlet of the refrigerant pump 5b. The control device (not shown in the figure) may be electrically connected to the throttling device 8b and the subcooling degree detector, and is used to receive the temperature detection value and pressure detection value from the subcooling degree detector, and obtain the subcooling degree detection value of the refrigerant at the inlet of the refrigerant pump 5b according to the temperature detection value and pressure detection value. The control device is further used to control the refrigeration system 100b according to the subcooling degree detection value of the refrigerant at the inlet of the refrigerant pump 5b, for example, to adjust the opening degree of the throttling device 8b, so as to adjust the subcooling degree of the refrigerant at the inlet of the refrigerant pump 5b. The method by which the control device controls the refrigeration system 100b to adjust the subcooling degree of the refrigerant will be described later.

[0121] Exemplarily, the refrigeration system 100b may further include a second valve 9b. The second valve 9b is connected between the outlet 312b of the first channel 31b of the heat exchange device 3b and the compressor 7b, and is used to control the discharge of the refrigerant in the first channel 31b. In this embodiment, the control device may be electrically connected to the throttling device 8b and the second valve 9b. The control device is further used to control the refrigeration system 100b according to the subcooling degree detection value of the refrigerant at the inlet of the refrigerant pump 5b, for example, to adjust the opening degree of the throttling device 8b and open or close the second valve 9b, so as to adjust the subcooling degree of the refrigerant at the inlet of the refrigerant pump 5b.

[0122] Exemplarily, the liquid storage tank 2b has an inlet 21b, an outlet 22b and a bypass outlet 24b. The inlet 21b and the outlet 22b are respectively located at both ends of the liquid storage tank 2b. The liquid storage tank 2b includes a liquid region 92b and a gas region 91b. The region occupied when all the liquid refrigerant circulating in the refrigeration system 100 is filled into the liquid storage tank 2b is the liquid region 92b of the liquid storage tank 2b. Among them, the liquid region 92b is located at the lower side of the liquid storage tank 2b, and the gas region 91b is located at the upper side of the liquid storage tank 2b.

[0123] Exemplarily, the bypass outlet 24b may be connected to the gaseous region 91b. The inlet 311b of the first channel 31b is connected to the bypass outlet 24b of the liquid storage tank 2b. When the refrigeration system 100b is in the mode of mixed operation of the compressor 7b and the refrigerant pump 5b, the compressor 7b can suck the gaseous refrigerant in the first channel 31b out of the first channel 31b, pressurize it together with the gaseous refrigerant from the evaporator 6a, and send it to the condenser 1b. The condenser 1b condenses the gaseous refrigerant into a liquid refrigerant and sends it back to the liquid storage tank 2b from the inlet 21b of the liquid storage tank 2b. It can be understood that in the mixed operation mode, due to the relatively small head provided by the refrigerant pump 5b, the pressure of the gaseous refrigerant at the inlet of the compressor 7b is equal to or less than the pressure of the gaseous refrigerant in the first channel 31b, so that the gaseous refrigerant in the first channel 31b enters the compressor 7b under the action of the pressure difference. It can be understood that the pressure difference between the inlet and the outlet of the refrigerant pump 5b is the head of the refrigerant pump 5b. This embodiment can use the compressor 7b as the driving device 4b, thus eliminating the vacuum pump and reducing the energy consumption of the refrigeration system 100b.

[0124] Please refer to Figure 4 and Figure 5 , Figure 5 which is a schematic flow chart of a control method for a refrigeration system 100b provided by an embodiment of the present application. Figure 4 The control method shown is used to adjust the subcooling degree of the refrigerant in the refrigeration system 100b. Please refer to Figure 5 and Figure 2 and Figure 5 In this embodiment, Figure 4 the control method of the refrigeration system 100b shown can refer to Figure 2 the control Figure 1 method of the refrigeration system 100 shown, and only the differences will be described here.

[0125] Exemplarily, the control method of the refrigeration system 100b may include:

[0126] Step S1: Control a first part of the refrigerant to flow from the liquid storage tank 2b through the second channel 32b into the refrigerant pump 5b.

[0127] Step S2: Obtain the detected value of the subcooling degree of the refrigerant at the inlet of the refrigerant pump 5b;

[0128] Step S3: Determine whether the detected value of the subcooling degree is less than or equal to a first subcooling degree preset value;

[0129] If the subcooling degree detection value is less than or equal to the first subcooling degree preset value, adjust the opening degree of the throttling device 8b so that the second part of the refrigerant enters the first channel 31b from the liquid storage tank 2b through the throttling device 8b, and control the throttling device 8b to reduce the pressure and temperature of the second part of the refrigerant so that the second pressure is less than the first pressure and the second temperature is less than the first temperature. The second part of the refrigerant absorbs the heat of the first part of the refrigerant in the second channel 32b to reduce the temperature of the first part of the refrigerant flowing into the refrigerant pump 5b, and control the compressor 7b to transport the refrigerant in the first channel 31b to the liquid storage tank 2b.

[0130] Exemplarily, step S3 may further include: if the subcooling degree detection value is greater than the first subcooling degree preset value, close the throttling device 8b.

[0131] Exemplarily, step S3 may further include: if the subcooling degree detection value is less than or equal to the first subcooling degree preset value, obtain the subcooling degree detection value of the refrigerant at the inlet of the refrigerant pump 5b again after the first time period, and perform such a cycle until the subcooling degree detection value is greater than the first subcooling degree preset value.

[0132] Exemplarily, the control method of the refrigeration system 100b may further include:

[0133] Step S4: If the subcooling degree detection value is greater than the first subcooling degree preset value, determine whether the subcooling degree detection value is less than or equal to the second subcooling degree preset value;

[0134] If the subcooling degree detection value is greater than the first subcooling degree preset value and less than or equal to the second subcooling degree preset value, obtain the subcooling degree detection value of the refrigerant at the inlet of the refrigerant pump 5b again after the second time period, and perform such a cycle until the subcooling degree detection value is greater than the second subcooling degree preset value.

[0135] In this embodiment, the subcooling degree detection value may be between the first subcooling degree preset value and the second subcooling degree preset value, or slightly greater than the second subcooling degree preset value to ensure the stable operation of the refrigerant pump 5b.

[0136] Exemplarily, step S4 may further include: if the subcooling degree detection value is greater than the second subcooling degree preset value, close the throttling device 8b.

[0137] Exemplarily, the throttling device 8b of the refrigeration system 100b may be a throttle valve. By reducing the opening degree of the throttling device 8b, the subcooling degree of the refrigerant at the inlet of the refrigerant pump 5b can be increased.

[0138] Wherein, the specific steps of adjusting the opening degree of the throttling device 8b in step S3 and / or step S4 may include:

[0139] Determine whether the throttling device 8b is in a closed state;

[0140] If the throttling device 8b is in the closed state, increase the opening degree of the throttling device 8b; if the throttling device 8b is in the open state, decrease the opening degree of the throttling device 8b to increase the supercooling degree of the refrigerant at the inlet of the refrigerant pump 5b.

[0141] Please refer to Figure 4 and Figure 6 , Figure 6 is the flow schematic diagram of the control method of the refrigeration system 100b provided by the present application in some other embodiments. Figure 4 The shown control method is used to adjust the supercooling degree of the refrigerant of the refrigeration system 100b. Please refer to Figure 6 and Figure 5 and Figure 6 , in this embodiment, Figure 6 the shown control method can refer to Figure 5 the shown control method, and only the differences will be described herein.

[0142] In some other embodiments, the refrigeration system 100b may further include a second valve 9b. Exemplarily, the control method of the refrigeration system 100b may include:

[0143] Step S1: Control the first part of the refrigerant to flow from the liquid storage tank 2b through the second channel 32b into the refrigerant pump 5b.

[0144] Step S2: Obtain the supercooling degree detection value of the refrigerant at the inlet of the refrigerant pump 5b;

[0145] Step S3: Determine whether the supercooling degree detection value is less than or equal to the first supercooling degree preset value;

[0146] If the supercooling degree detection value is less than or equal to the first supercooling degree preset value, adjust the opening degree of the throttling device 8b so that the second part of the refrigerant enters the first channel 31b from the liquid storage tank 2b through the throttling device 8b, and control the throttling device 8b to reduce the pressure and temperature of the second part of the refrigerant so that the second pressure is less than the first pressure and the second temperature is less than the first temperature. The second part of the refrigerant absorbs the heat of the first part of the refrigerant in the second channel 32b to reduce the temperature of the first part of the refrigerant flowing into the refrigerant pump 5b, and open the second valve 9b, and control the compressor 7b to transport the refrigerant in the first channel 31b to the liquid storage tank 2b.

[0147] Exemplarily, step S3 may further include: if the supercooling degree detection value is greater than the first supercooling degree preset value, close the throttling device 8b and the second valve 9b.

[0148] Exemplarily, step S3 may further include: if the subcooling degree detection value is less than or equal to the first subcooling degree preset value, then after a first time period, the subcooling degree detection value of the refrigerant at the inlet of the refrigerant pump 5b is acquired again, and this cycle is performed until the subcooling degree detection value is greater than the first subcooling degree preset value.

[0149] Step S4: if the subcooling degree detection value is greater than the first subcooling degree preset value, then determine whether the subcooling degree detection value is less than or equal to the second subcooling degree preset value;

[0150] If the subcooling degree detection value is greater than the first subcooling degree preset value and less than or equal to the second subcooling degree preset value, then after a second time period, the subcooling degree detection value of the refrigerant at the inlet of the refrigerant pump 5b is acquired again, and this cycle is performed until the subcooling degree detection value is greater than the second subcooling degree preset value.

[0151] Exemplarily, step S4 may further include: if the subcooling degree detection value is greater than the second subcooling degree preset value, then close the throttling device 8b and the second valve 9b.

[0152] Please refer to Figure 7 , Figure 7 which is a schematic diagram of the refrigeration system 100c provided by the present application in some other embodiments.

[0153] In the fourth embodiment, the refrigeration system 100c may include a condenser 1c, a liquid storage tank 2c, a heat exchange device 3c, a driving device 4c, a refrigerant pump 5c, an evaporator 6c, a compressor 7c, and a throttling device 8c that form a circulation loop.

[0154] It can be understood that the multiple devices included in the refrigeration system 100c in the fourth embodiment and the connections between the multiple devices may refer to the refrigeration system 100 in the first embodiment, and only the differences between the two are described herein.

[0155] In the fourth embodiment, the heat exchange device 3c may include a first channel 31c and a second channel 32c. The first channel 31c is provided with an inlet 311c and an outlet. The inlet 311c of the first channel 31c is connected to the liquid storage tank 2c. The refrigerant in the liquid storage tank 2c has a first pressure and a first temperature, and the refrigerant in the first channel 31c has a second pressure and a second temperature. The throttling device 8c is connected between the liquid storage tank 2c and the inlet 311c of the first channel 31c. The throttling device 8c can reduce the pressure and temperature of the refrigerant flowing through the throttling device 8c, so that the second pressure is less than the first pressure and the second temperature is less than the first temperature. The driving device 4c is connected to the outlet of the first channel 31c and the liquid storage tank 2c, and is used to transport the refrigerant in the first channel 31c to the liquid storage tank 2c. Among them, the second channel 32c is connected between the liquid storage tank 2c and the refrigerant pump 5c, and heat exchange can be carried out between the second channel 32c and the first channel 31c. The refrigerant in the liquid storage tank 2c flows into the refrigerant pump 5c through the second channel 32c, and the refrigerant transfers heat to the refrigerant in the first channel 31c in the second channel 32c to reduce the temperature of the refrigerant flowing into the refrigerant pump 5c, thereby increasing the subcooling degree of the refrigerant flowing into the refrigerant pump 5c. In some other embodiments, the refrigeration system 100c may also not include the driving device 4c, and the present application does not limit this.

[0156] In the fourth embodiment, when the temperature outside the data center is relatively low, for example, in the working conditions of outdoor transitional weather and low-temperature weather, driving the refrigerant cycle for refrigeration by the refrigerant pump 5c can meet the refrigeration demand, and the energy consumption of the refrigerant pump 5c is small, which is beneficial to meeting the low-energy consumption requirements of the data center. When the temperature outside the data center is relatively high, the refrigerant pump 5c and the compressor 7c can be used to drive the refrigerant cycle, and the refrigeration capacity of the refrigeration system 100c is better to meet the refrigeration demand of the data center at a higher external temperature. In addition, compared with only using the compressor 7c, the work done by the compressor 7c is reduced, thereby reducing the energy consumption of the refrigeration system 100c and achieving an energy-saving effect.

[0157] In the fourth embodiment, the driving device 4c may include a compressor 7c and a vacuum pump 41c. The outlet of the first channel 31c includes a first outlet 312c and a second outlet 313c. The vacuum pump 41c is connected to the first outlet 312c of the first channel 31c and the liquid storage tank 2c, and the second outlet 313c of the first channel 31c is connected to the compressor 7c.

[0158] Among them, when the compressor 7c in the refrigeration system 100c operates, the vacuum pump 41c can be turned off. At this time, the compressor 7c serves as the driving device 4c. In addition, due to the small head of the refrigerant pump, the pressure of the refrigerant entering the compressor 7c through the refrigerant pump 5c is still greater than the pressure of the refrigerant in the first channel 31c, that is, the pressure of the refrigerant at the inlet of the compressor 7c is greater than the pressure of the refrigerant in the first channel 31c. The refrigerant in the first channel 31c can enter the compressor 7c under the action of the pressure difference. In this embodiment, the refrigeration system 100c can adopt Figure 5 the control method shown.

[0159] Exemplarily, the refrigeration system 100c may further include a second valve (not shown in the figure). The second valve is connected between the second outlet 313c of the first channel 31c and the compressor 7c, that is, the second valve is connected between the outlet of the first channel 31c and the compressor 7c. In this embodiment, the refrigeration system 100c can adopt Figure 6 the control method shown.

[0160] Among them, when the compressor 7c in the refrigeration system 100c is turned off, the vacuum pump 41c is turned on. At this time, the vacuum pump 41c serves as the driving device 4c. In this embodiment, the refrigeration system 100c can adopt Figure 2 the control method shown.

[0161] Exemplarily, the driving device 4c may further include an intake pipe 42c. One end of the intake pipe 42c is connected to the vacuum pump 41c, and the other end of the intake pipe 42c is connected to the gaseous region 91c of the liquid storage tank 2c. The intake pipe 42c is connected to the gaseous region 91c of the liquid storage tank 2c, thereby preventing the refrigerant output from the intake pipe 42c from disturbing the liquid refrigerant in the liquid storage tank 2c and generating bubbles, and being able to prevent cavitation of the liquid refrigerant, so that the refrigerant pump 5c can operate stably.

[0162] The above description is only the specific implementation manner of the present application, but the protection scope of the present application is not limited thereto. Any person skilled in the art within the technical scope disclosed by the present application can easily think of changes or substitutions, which should all be covered within the protection scope of the present application. Without conflict, the embodiments of the present application and the features in the embodiments can be combined with each other. Therefore, the protection scope of the present application should be subject to the protection scope of the claims.

Claims

1. A refrigeration system, characterized in that, it includes a liquid storage tank, a refrigerant pump, an evaporator and a condenser that form a circulation loop; the refrigeration system further includes a throttling device and a heat exchange device, the heat exchange device includes a first channel and a second channel, the refrigerant in the liquid storage tank has a first pressure and a first temperature, the refrigerant in the first channel has a second pressure and a second temperature, the throttling device is connected between the liquid storage tank and the first channel, and the throttling device can reduce the pressure and temperature of the refrigerant flowing through the throttling device, so that the second pressure is less than the first pressure and the second temperature is less than the first temperature; the second channel is connected between the liquid storage tank and the refrigerant pump, and heat exchange can be carried out between the second channel and the first channel. The refrigerant in the liquid storage tank flows into the refrigerant pump through the second channel, and the refrigerant in the second channel transfers heat to the refrigerant in the first channel to reduce the temperature of the refrigerant flowing into the refrigerant pump.

2. The refrigeration system according to claim 1, characterized in that, the refrigeration system further includes a driving device. The first channel is provided with an inlet and an outlet. The throttling device is connected between the liquid storage tank and the inlet of the first channel. The driving device is connected to the outlet of the first channel and the liquid storage tank for transporting the refrigerant in the first channel to the liquid storage tank.

3. The refrigeration system according to claim 2, characterized in that, the refrigeration system further includes a compressor, and the compressor is connected between the evaporator and the condenser.

4. The refrigeration system according to claim 2 or 3, characterized in that, the driving device includes a vacuum pump, and the vacuum pump is connected between the outlet of the first channel and the liquid storage tank.

5. The refrigeration system according to claim 3, characterized in that, the driving device includes the compressor, and the outlet of the first channel is connected to the compressor.

6. The refrigeration system according to claim 5, characterized in that, the driving device further includes a vacuum pump. The outlet of the first channel includes a first outlet and a second outlet. The vacuum pump is connected between the first outlet of the first channel and the liquid storage tank, and the second outlet of the first channel is connected to the compressor.

7. The refrigeration system according to claim 5 or 6, characterized in that, the refrigeration system further includes a second valve, and the second valve is connected between the outlet of the first channel and the compressor.

8. The refrigeration system according to claim 4 or 6, characterized in that, the liquid storage tank includes a liquid region and a gas region. The liquid refrigerant in the liquid storage tank is located in the liquid region, and the gaseous refrigerant in the liquid storage tank is located in the gas region. The refrigeration system further includes an intake pipe, one end of the intake pipe is connected to the vacuum pump, and the other end is connected to the gas region of the liquid storage tank.

9. The refrigeration system according to any one of claims 1 to 8, characterized in that, the throttling device adopts a throttle valve or a capillary tube.

10. The refrigeration system according to any one of claims 1 to 9, characterized in that, The heat exchange device adopts a shell-and-tube heat exchanger, a double-pipe heat exchanger or a plate heat exchanger.

11. The refrigeration system according to any one of claims 1 to 10, characterized in that, the refrigeration system further includes an expansion valve, and the expansion valve is connected between the refrigerant pump and the evaporator.

12. The refrigeration system according to any one of claims 1 to 11, characterized in that, the refrigeration system further includes a subcooling degree detector, and the subcooling degree detector is arranged at the inlet of the refrigerant pump for detecting the temperature and pressure of the refrigerant at the inlet of the refrigerant pump to obtain a temperature detection value and a pressure detection value of the refrigerant at the inlet of the refrigerant pump.

13. The refrigeration system according to claim 12, characterized in that, the refrigeration system further includes a control device, the control device is electrically connected to the subcooling degree detector, the subcooling degree detector can transmit the temperature detection value and the pressure detection value to the control device, and the control device can obtain a subcooling degree detection value of the refrigerant at the inlet of the refrigerant pump through the temperature detection value and the pressure detection value.

14. A control method for a refrigeration system, characterized in that, the refrigeration system includes a liquid storage tank, a refrigerant pump, an evaporator and a condenser forming a circulation loop; the refrigeration system further includes a heat exchange device, a throttling device and a vacuum pump, the heat exchange device includes a first channel and a second channel, the first channel is provided with an inlet and an outlet, the inlet of the first channel is connected to the liquid storage tank, the throttling device is connected between the liquid storage tank and the inlet of the first channel, the refrigerant in the liquid storage tank has a first pressure and a first temperature, the refrigerant in the first channel has a second pressure and a second temperature, the vacuum pump is connected to the outlet of the first channel and the liquid storage tank, the second channel is connected between the liquid storage tank and the refrigerant pump, and heat exchange can be carried out between the second channel and the first channel; the throttling device is a throttle valve; the control method includes: controlling a first part of the refrigerant to flow from the liquid storage tank through the second channel into the refrigerant pump; obtaining a subcooling degree detection value of the refrigerant at the inlet of the refrigerant pump; if the subcooling degree detection value is less than or equal to a first subcooling degree preset value, adjusting the opening degree of the throttling device so that a second part of the refrigerant enters the first channel from the liquid storage tank through the throttling device, and controlling the throttling device to reduce the pressure and temperature of the second part of the refrigerant, so that the second pressure is less than the first pressure and the second temperature is less than the first temperature, and the second part of the refrigerant absorbs the heat of the first part of the refrigerant in the second channel to reduce the temperature of the first part of the refrigerant flowing into the refrigerant pump, and controlling the vacuum pump to transport the second part of the refrigerant in the first channel to the liquid storage tank.

15. The control method according to claim 14, characterized in that, the control method further includes: if the subcooling degree detection value is greater than the first subcooling degree preset value, closing the throttling device and the vacuum pump.

16. The control method according to claim 14, characterized in that, the control method further comprises: if the subcooling degree detection value is greater than the first subcooling degree preset value and less than or equal to the second subcooling degree preset value, then after a second time period, the subcooling degree detection value of the refrigerant at the inlet of the refrigerant pump is acquired again, and the second subcooling degree preset value is greater than the first subcooling degree preset value; if the subcooling degree detection value is greater than the second subcooling degree preset value, the throttling device and the vacuum pump are closed.

17. The control method according to any one of claims 14 to 16, characterized in that, the refrigeration system further comprises a compressor, and the compressor is connected between the evaporator and the condenser.

18. A control method for a refrigeration system, characterized in that, the refrigeration system comprises a liquid storage tank, a refrigerant pump, an evaporator, a compressor and a condenser forming a circulation loop; the refrigeration system further comprises a heat exchange device and a throttling device, the heat exchange device comprises a first channel and a second channel, the first channel is provided with an inlet and an outlet, the throttling device is connected between the liquid storage tank and the inlet of the first channel, the refrigerant in the liquid storage tank has a first pressure and a first temperature, the refrigerant in the first channel has a second pressure and a second temperature, the outlet of the first channel is connected to the compressor, the second channel is connected between the liquid storage tank and the refrigerant pump, and heat exchange can be performed between the second channel and the first channel; the throttling device is a throttle valve; the control method comprises: controlling a first part of the refrigerant to flow from the liquid storage tank through the second channel into the refrigerant pump; acquiring the subcooling degree detection value of the refrigerant at the inlet of the refrigerant pump; if the subcooling degree detection value is less than or equal to the first subcooling degree preset value, adjusting the opening degree of the throttling device so that a second part of the refrigerant enters the first channel from the liquid storage tank through the throttling device, and controlling the throttling device to reduce the pressure and temperature of the second part of the refrigerant so that the second pressure is less than the first pressure and the second temperature is less than the first temperature, and the second part of the refrigerant absorbs the heat of the first part of the refrigerant in the second channel to reduce the temperature of the first part of the refrigerant flowing into the refrigerant pump, and controlling the compressor to transport the second part of the refrigerant in the first channel to the liquid storage tank.

19. The control method according to claim 18, characterized in that, the control method further comprises: if the subcooling degree detection value is greater than the first subcooling degree preset value, closing the throttling device.

20. The control method according to claim 18, characterized in that, the control method further comprises: if the subcooling degree detection value is greater than the first subcooling degree preset value and less than or equal to the second subcooling degree preset value, then after a second time period, the subcooling degree detection value of the refrigerant at the inlet of the refrigerant pump is acquired again, and the second subcooling degree preset value is greater than the first subcooling degree preset value; if the subcooling degree detection value is greater than the second subcooling degree preset value, closing the throttling device.

21. The control method according to any one of claims 14 to 20, characterized in that, the adjusting the opening degree of the throttling device includes: if the throttling device is in a closed state, increasing the opening degree of the throttling device; if the throttling device is in an open state, decreasing the opening degree of the throttling device.

22. The control method according to any one of claims 14 to 21, characterized in that, the control method further includes: if the detected value of the degree of undercooling is less than or equal to the first preset value of the degree of undercooling, acquiring the detected value of the degree of undercooling again after a first time period.

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