Refrigeration system and control method for a refrigeration system

Abstract

The application discloses a refrigeration system and a control method thereof. The refrigeration system is used for a vehicle and comprises a compressor, a condenser, a liquid storage tank, an evaporator, a first branch and a pressure relief valve. One end of the condenser is communicated with a discharge port of the compressor; the other end of the condenser is communicated with an internal space of the liquid storage tank, the liquid storage tank is internally provided with a heat exchange pipe, one end of the heat exchange pipe is communicated with a return air port of the compressor; one end of the evaporator is communicated with the internal space of the liquid storage tank, and the other end of the evaporator is communicated with the other end of the heat exchange pipe; the first branch is connected with the discharge port of the compressor and one end of the heat exchange pipe which is away from the return air port of the compressor; and the pressure relief valve is arranged on the first branch. According to the refrigeration system, when the pressure of the refrigerant flowing out of the discharge port of the compressor is too large, the pressure values at the discharge port and the intake port of the compressor can be adjusted, the compressor can be prevented from being in an overload state for a long time, the refrigeration system can be prevented from being caused to fail, and the refrigeration of the vehicle can be prevented from being invalid.

Description

TECHNICAL FIELD

[0001] The present application mainly relates to the technical field of refrigeration systems, and in particular to a refrigeration system and a control method of the refrigeration system. BACKGROUND

[0002] In the prior art, the compressor of the refrigeration system of a vehicle can compress and pressurize refrigerant, but lacks protection measures for high-pressure gas discharged by the compressor to the condenser. When the pressure difference of the compressor is large, the compressor is prone to be in an overload state for a long time, which will cause over-power and over-flow of the compressor, and further cause failure of the refrigeration system, resulting in stopping of the vehicle from refrigeration or heating. SUMMARY

[0003] The present application aims to at least solve one of the technical problems in the prior art. To this end, the present application provides a refrigeration system, which can adjust the pressure values at the discharge port and the intake port of the compressor, so as to avoid the compressor being in an overload state for a long time and causing failure of the refrigeration system.

[0004] The present application also provides a control method of a refrigeration system, wherein the refrigeration system in the control method is the refrigeration system described above.

[0005] The refrigeration system according to the embodiments of the present application is used for a vehicle and comprises a compressor, a condenser, a liquid storage tank, an evaporator, a first branch and a pressure relief valve. One end of the condenser is in communication with a discharge port of the compressor; the other end of the condenser is in communication with an internal space of the liquid storage tank, which has a heat exchange pipe therein, one end of the heat exchange pipe being in communication with a back gas port of the compressor; one end of the evaporator is in communication with the internal space of the liquid storage tank, and the other end of the evaporator is in communication with the other end of the heat exchange pipe; the first branch connects the discharge port of the compressor and one end of the heat exchange pipe which is away from the back gas port of the compressor; and the pressure relief valve is arranged on the first branch.

[0006] According to the refrigeration system of the embodiment of the present application, one end of the condenser is communicated with the exhaust port of the compressor, the other end of the condenser is communicated with the internal space of the liquid storage tank, the liquid storage tank has the heat exchange pipe therein, one end of the heat exchange pipe is communicated with the return air port of the compressor, one end of the evaporator is communicated with the internal space of the liquid storage tank, and the other end of the evaporator is communicated with the other end of the heat exchange pipe. The liquid storage tank can realize heat exchange between the liquid refrigerant or gas-liquid mixed refrigerant with higher temperature in the internal space of the liquid storage tank and the gaseous refrigerant or gas-liquid mixed refrigerant with lower temperature in the heat exchange pipe, and improve the heat exchange performance of the liquid refrigerant after entering the evaporator. The pressure relief valve is arranged on the first branch connected with the exhaust port of the compressor and the end of the heat exchange pipe away from the return air port of the compressor. When the pressure of the refrigerant flowing out of the exhaust port of the compressor is too large, the pressure relief valve on the first branch can open the first branch, and the compressor can discharge pressure to the heat exchange pipe through the first branch, so as to adjust the pressure values at the exhaust port and the intake port of the compressor, avoid the compressor being in the overloading state for a long time, avoid the problems of over-power and over-flow of the compressor, avoid causing the refrigeration system to fail, and avoid causing the refrigeration of the vehicle to fail.

[0007] In some embodiments of the present application, the refrigeration system further comprises a first sensor for detecting the temperature and pressure of the refrigerant flowing from the exhaust port of the compressor to the condenser.

[0008] In some embodiments of the present application, the exhaust port of the compressor and the condenser are connected through a second branch, and the first sensor is arranged on the second branch.

[0009] In some embodiments of the present application, the refrigeration system further comprises a second sensor for detecting the pressure of the refrigerant flowing from the evaporator to the heat exchange pipe.

[0010] In some embodiments of the present application, the evaporator and the heat exchange pipe are connected through a third branch, and the second sensor is arranged on the third branch.

[0011] In some embodiments of the present application, the refrigeration system further comprises an expansion valve arranged between the liquid storage tank and the evaporator.

[0012] In some embodiments of the present application, the refrigeration system further comprises a refrigeration circuit, which comprises a refrigeration heat exchanger, a refrigeration core and a refrigeration water pump. The refrigeration heat exchanger and the refrigeration core are connected to form a circuit, the refrigeration water pump is arranged between the refrigeration heat exchanger and the refrigeration core, and is used to drive the circulation of the heat exchange medium between the refrigeration heat exchanger and the refrigeration core. The refrigeration heat exchanger exchanges heat with the evaporator.

[0013] In some embodiments of the present application, the refrigeration system further comprises a heating circuit, the heating circuit comprising a heating heat exchanger, a heating core and a heating water pump, the heating heat exchanger and the heating core being connected to form a circuit, the heating water pump being arranged between the heating heat exchanger and the heating core for driving the circulation of the heat exchange medium between the heating heat exchanger and the heating core, the heating heat exchanger and the condenser being in heat exchange.

[0014] The control method of the refrigeration system according to the embodiments of the present application, the refrigeration system being the refrigeration system described above, the control method of the refrigeration system comprising: obtaining refrigerant pressure P1 flowing into the condenser and refrigerant pressure P2 flowing out of the evaporator; determining whether the compressor satisfies a starting condition according to the refrigerant pressure P1 and the refrigerant pressure P2; if the compressor satisfies the starting condition, controlling the compressor to operate at a target speed according to the refrigerant pressure P1 and the refrigerant pressure P2; if the compressor does not satisfy the starting condition, opening the pressure relief valve to make the compressor satisfy the starting condition.

[0015] The control method of the refrigeration system according to the embodiments of the present application, by connecting one end of the condenser with the exhaust port of the compressor, connecting the other end of the condenser with the internal space of the liquid storage tank, having a heat exchange pipe in the liquid storage tank, connecting one end of the heat exchange pipe with the return air port of the compressor, connecting one end of the evaporator with the internal space of the liquid storage tank, and connecting the other end of the evaporator with the other end of the heat exchange pipe. The liquid storage tank can realize heat exchange between the liquid refrigerant or gas-liquid mixed refrigerant with higher temperature in the internal space of the liquid storage tank and the gaseous refrigerant or gas-liquid mixed refrigerant with lower temperature in the heat exchange pipe, and improve the heat exchange performance of the liquid refrigerant after entering the evaporator. The pressure relief valve is arranged on the first branch connecting the exhaust port of the compressor and the end of the heat exchange pipe away from the return air port of the compressor. When the pressure of the refrigerant flowing out of the exhaust port of the compressor is too high, the pressure relief valve on the first branch can open the first branch, and the compressor can discharge pressure to the heat exchange pipe through the first branch, so as to adjust the pressure values at the exhaust port and the intake port of the compressor, avoid the compressor being in an overloading state for a long time, avoid the problems of over-power and over-flow of the compressor, avoid causing the failure of the refrigeration system, and avoid causing the refrigeration failure of the vehicle.

[0016] In some embodiments of the present application, the starting condition of the compressor comprises that the refrigerant pressure P1 and the refrigerant pressure P2 satisfy the following conditions simultaneously: 0.1 MPa≤P2≤3.2 MPa, 0.1 MPa≤P1≤0.8 MPa, and P1≤P2+2.9.

[0017] In some embodiments of the present application, the control of the compressor to operate at the target speed according to the refrigerant pressure P1 and the refrigerant pressure P2 comprises:

[0018] The refrigerant pressure P1 and the refrigerant pressure P2 are in an overlapping region defined by three conditions of 0.1MPa≤P2≤1.8MPa, 0.3MPa≤P1≤0.6MPa, P1≤2*P2+1, and the compressor is controlled to operate at a first target speed; the refrigerant pressure P1 and the refrigerant pressure P2 are in an overlapping region defined by three conditions of 0.1MPa≤P2≤3.2MPa, 0.1MPa≤P1≤0.8MPa, P1≤P2+2.9, and outside the overlapping region defined by three conditions of 0.1MPa≤P2≤1.8MPa, 0.3MPa≤P1≤0.6MPa, P1≤2*P2+1, and the compressor is controlled to operate at a second target speed, wherein the first target speed is less than the second target speed.

[0019] In some embodiments of the present application, the first target speed is 800-3000rpm, and / or the second target speed is 3000-10000rpm.

[0020] In some embodiments of the present application, the refrigeration system is applied to a vehicle, and the control method of the refrigeration system further comprises:

[0021] According to the refrigerant pressure P1, the refrigerant pressure P2, and the demand of the vehicle for the refrigeration capacity of the refrigeration system, it is judged whether the refrigeration system is in a stable operation state; when the refrigeration system is in a non-stable operation state, the opening or closing of the pressure relief valve and the opening degree when opened are adjusted.

[0022] In some embodiments of the present application, the stable operation state comprises: the refrigerant pressure P1 and the refrigerant pressure P2 simultaneously satisfy 0.1MPa≤P2≤3.2MPa, 0.1MPa≤P1≤0.8MPa, P1≤P2+2.9.

[0023] In some embodiments of the present application, when the refrigeration system is in a stable operation state, the control method of the refrigeration system further comprises:

[0024] It is judged whether the refrigeration system is in an optimal operation interval; when the refrigeration system is not in the optimal operation interval, the opening or closing of the pressure relief valve and the opening degree when opened are adjusted.

[0025] In some embodiments of the present application, the optimal operation interval comprises: the speed of the compressor is 3000-5000rpm.

[0026] Additional aspects and advantages of the present application will be made apparent from the following description. BRIEF DESCRIPTION OF DRAWINGS

[0027] The above and / or additional aspects and advantages of the present application will become apparent and more readily appreciated from the following description, taken in conjunction with the following drawings of which:

[0028] Figure 1 is a schematic view of a pressure relief valve opening a first branch of a refrigeration system according to an embodiment of the present application;

[0029] Figure 2 is a schematic view of a pressure relief valve closing a first branch of a refrigeration system according to an embodiment of the present application;

[0030] Figure 3 is a schematic view of a pressure range of a compressor of a control method of a refrigeration system according to an embodiment of the present application;

[0031] Figure 4 is a flowchart of a control method of a refrigeration system according to an embodiment of the present application.

[0032] Reference numerals:

[0033] 100, a refrigeration system;

[0034] 1, a compressor; 11, a discharge port; 12, a suction port; 13, a first branch;

[0035] 2, a condenser;

[0036] 3, a receiver; 31, a heat exchange tube;

[0037] 4, an evaporator; 41, an expansion valve;

[0038] 5, a pressure relief valve;

[0039] 6, a first sensor; 61, a second branch;

[0040] 7, a second sensor; 71, a third branch;

[0041] 8, a refrigeration circuit; 81, a refrigeration heat exchanger; 82, a refrigeration core; 83, a refrigeration water pump;

[0042] 9, a heating circuit; 91, a heating heat exchanger; 92, a heating core; 93, a heating water pump;

[0043] 10, an optimal operation range. DETAILED DESCRIPTION

[0044] Embodiments of the present application are described in detail below with reference to the attached drawings, which show by way of example, embodiments in which like numerals indicate like elements or elements having the same or similar function. The embodiments described below are exemplary only, and are not to be construed as limiting the present application.

[0045] In the description of the present application, it is to be understood that the orientations or positional relationships indicated by the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like are based on the orientations or positional relationships shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the present application. In addition, the features defined with "first", "second" can explicitly or implicitly include one or more of the features. In the description of the present application, unless otherwise specified, the meaning of "a plurality of" is two or more.

[0046] In the description of the present application, it should be noted that, unless otherwise specified and limited, the terms "mounting", "connecting", "connection" should be understood broadly, for example, it can be fixedly connected, or it can be detachably connected, or integrally connected; it can be mechanically connected, or it can be electrically connected; it can be directly connected, or it can be indirectly connected through an intermediate medium; it can be the communication inside two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0047] Reference will be made to the drawings Figures 1-2 The refrigeration system 100 according to an embodiment of the present application is described.

[0048] As Figure 1 shown, the refrigeration system 100 according to an embodiment of the present application includes a compressor 1, a condenser 2, a liquid accumulator 3, an evaporator 4, a first branch 13, and a pressure relief valve 5.

[0049] Specifically, the refrigeration system 100 is used in a vehicle, such as Figure 1 and Figure 2As shown, one end of the condenser 2 is communicated with the exhaust port 11 of the compressor 1, the other end of the condenser 2 is communicated with the internal space of the liquid storage tank 3, the liquid storage tank 3 has a heat exchange pipe 31, one end of the heat exchange pipe 31 is communicated with the return port 12 of the compressor 1, one end of the evaporator 4 is communicated with the internal space of the liquid storage tank 3, and the other end of the heat exchange pipe 31 is communicated with the other end of the evaporator 4. It can be understood that when the refrigeration system 100 works, the liquid refrigerant in the internal space of the liquid storage tank 3 enters the evaporator 4, the liquid refrigerant exchanges heat with the external environment in the evaporator 4, the refrigerant in the evaporator 4 absorbs heat and changes phase, and the low-temperature gaseous refrigerant or gas-liquid mixed refrigerant after phase change enters the heat exchange pipe 31 and exchanges heat with the high-temperature liquid refrigerant in the internal space of the liquid storage tank 3, which can increase the temperature of the gaseous refrigerant or gas-liquid mixed refrigerant in the heat exchange pipe 31, promote the refrigerant in the heat exchange pipe 31 to change into gaseous refrigerant, and increase the temperature of the liquid refrigerant in the liquid storage tank 3, so that the temperature of the liquid refrigerant entering the evaporator 4 is higher, which is convenient for the liquid refrigerant in the evaporator 4 to exchange heat with the external environment.

[0050] As shown in Figure 1 and Figure 2 , the gaseous refrigerant in the heat exchange pipe 31 flows out and enters the return port 12 of the compressor 1, the gaseous refrigerant is compressed into high-temperature and high-pressure gaseous refrigerant in the compressor 1, the high-temperature and high-pressure gaseous refrigerant enters the condenser 2 through the exhaust port 11 of the compressor 1, the high-temperature and high-pressure gaseous refrigerant in the condenser 2 exchanges heat with the external environment, the gaseous refrigerant in the condenser 2 changes phase and releases heat, the high-temperature liquid refrigerant or gas-liquid mixed refrigerant after phase change enters the internal space of the liquid storage tank 3 and exchanges heat with the low-temperature gaseous refrigerant or gas-liquid mixed refrigerant in the heat exchange pipe 31, realizing the circulation of the refrigeration system 100. And the liquid storage tank 3 can realize the heat exchange between the high-temperature liquid refrigerant or gas-liquid mixed refrigerant in the internal space of the liquid storage tank 3 and the low-temperature gaseous refrigerant or gas-liquid mixed refrigerant in the heat exchange pipe 31, which can perform secondary cooling for the liquid refrigerant or gas-liquid mixed refrigerant flowing out of the condenser 2 and entering the internal space of the liquid storage tank 3, and improve the heat exchange performance of the liquid refrigerant entering the evaporator 4.

[0051] As shown in Figure 1 and Figure 2As shown, the first branch 13 connects the exhaust port 11 of the compressor 1 and one end of the heat exchange pipe 31 away from the return air port 12 of the compressor 1, and the pressure relief valve 5 is arranged on the first branch 13. When the pressure of the refrigerant flowing out of the exhaust port 11 of the compressor 1 is too high, the pressure relief valve 5 on the first branch 13 can open the first branch 13, and the high-temperature and high-pressure gaseous refrigerant in the compressor 1 can be discharged to the heat exchange pipe 31 through the first branch 13, so as to adjust the pressure values at the exhaust port 11 and the intake port of the compressor 1, balance the pressure values inside the refrigeration system 100, avoid the compressor 1 being in an overload state for a long time, avoid the problems of over-power and over-flow of the compressor 1, avoid causing the refrigeration system 100 to fail, and avoid causing the refrigeration of the vehicle to fail.

[0052] According to the refrigeration system 100 of the embodiment of the present application, one end of the condenser 2 is communicated with the exhaust port 11 of the compressor 1, the other end of the condenser 2 is communicated with the internal space of the liquid storage tank 3, the liquid storage tank 3 has the heat exchange pipe 31, one end of the heat exchange pipe 31 is communicated with the return air port 12 of the compressor 1, one end of the evaporator 4 is communicated with the internal space of the liquid storage tank 3, and the other end of the evaporator 4 is communicated with the other end of the heat exchange pipe 31. The liquid storage tank 3 can realize heat exchange between the liquid refrigerant or the gas-liquid mixed refrigerant with a higher temperature in the internal space of the liquid storage tank 3 and the gaseous refrigerant or the gas-liquid mixed refrigerant with a lower temperature in the heat exchange pipe 31, and improve the heat exchange performance of the liquid refrigerant after entering the evaporator 4. Moreover, the pressure relief valve 5 is arranged on the first branch 13 connecting the exhaust port 11 of the compressor 1 and one end of the heat exchange pipe 31 away from the return air port 12 of the compressor 1. When the pressure of the refrigerant flowing out of the exhaust port 11 of the compressor 1 is too high, the pressure relief valve 5 on the first branch 13 can open the first branch 13, and the compressor 1 can be discharged to the heat exchange pipe 31 through the first branch 13, so as to adjust the pressure values at the exhaust port 11 and the intake port of the compressor 1, balance the pressure values inside the refrigeration system 100, avoid the compressor 1 being in an overload state for a long time, avoid the problems of over-power and over-flow of the compressor 1, avoid causing the refrigeration system 100 to fail, and avoid causing the refrigeration of the vehicle to fail.

[0053] In some embodiments of the present application, as shown in Figure 1 and Figure 2 As shown, the refrigeration system 100 further comprises a first sensor 6, which is used to detect the temperature and pressure of the refrigerant flowing from the exhaust port 11 of the compressor 1 to the condenser 2. When the temperature of the refrigerant flowing from the exhaust port 11 of the compressor 1 to the condenser 2 is too high, the first sensor 6 can transmit a signal to the controller of the refrigeration system 100, so as to realize the timely shutdown of the compressor 1 and avoid the compressor 1 from failing. At the same time, when the pressure of the refrigerant flowing from the exhaust port 11 of the compressor 1 to the condenser 2 is too high or too low, the first sensor 6 can transmit a signal to the controller of the refrigeration system 100, so as to realize the timely shutdown of the compressor 1 and avoid the compressor 1 from failing.

[0054] Further, as shown inFigure 1 and Figure 2 As shown, the compressor 1's exhaust port 11 and the condenser 2 are connected by a second branch 61. The first sensor 6 is located on the second branch 61. The first sensor 6 can conveniently detect the temperature and pressure of the refrigerant flowing from the compressor 1's exhaust port 11 to the condenser 2. When the pressure and temperature are abnormal, it transmits a signal to the controller of the refrigeration system 100 to realize the timely shutdown of the compressor 1 and avoid compressor 1 from malfunctioning.

[0055] In some embodiments of the present invention, such as Figure 1 and Figure 2 As shown, the refrigeration system 100 also includes a second sensor 7, which is used to detect the pressure of the refrigerant flowing from the evaporator 4 to the heat exchange tube 31. When the second sensor 7 detects that the pressure of the refrigerant flowing from the evaporator 4 to the heat exchange tube 31 is too high or too low, it can send a signal to the controller of the refrigeration system 100 to realize the timely shutdown of the compressor 1 and avoid compressor 1 failure.

[0056] Furthermore, such as Figure 1 and Figure 2 As shown, the evaporator 4 and the heat exchange tube 31 are connected by a third branch 71. The second sensor 7 is located on the third branch 71. The first sensor 6 can conveniently detect the pressure of the refrigerant flowing from the evaporator 4 to the heat exchange tube 31. When the pressure is abnormal, it transmits a signal to the controller of the refrigeration system 100 to realize the timely shutdown of the compressor 1 and avoid the compressor 1 from malfunctioning.

[0057] In some embodiments of the present invention, such as Figure 1 and Figure 2 As shown, the refrigeration system 100 also includes an expansion valve 41, which is located between the liquid receiver 3 and the evaporator 4. It can be understood that the gaseous refrigerant flowing out of the evaporator 4 enters the compressor 1 and is compressed into a high-temperature, high-pressure gaseous refrigerant within the compressor 1. The high-temperature, high-pressure gaseous refrigerant then enters the condenser 2, releasing heat and transforming into a high-pressure liquid refrigerant. The high-pressure liquid refrigerant then enters the expansion valve 41, where it is throttled and depressurized, causing the refrigerant to flow out of the expansion valve 41 as a low-pressure wet vapor, ensuring that the refrigerant can fully evaporate within the evaporator 4.

[0058] In some embodiments, the expansion valve 41 is an electronic expansion valve, and the second sensor 7 is a pressure and temperature sensor. The second sensor 7 can detect the pressure and temperature of the refrigerant flowing from the evaporator 4 to the heat exchange tube 31, thereby determining the superheat of the refrigerant flowing from the evaporator 4 to the heat exchange tube 31. For example, the superheat S, the saturation temperature T' of the refrigerant flowing out of the evaporator 4 at pressure P, and the refrigerant temperature T flowing out of the evaporator 4 satisfy: S = T - T'. The opening of the electronic expansion valve can be changed according to the superheat S, thereby changing the throttling and pressure reduction effect of the electronic expansion valve to ensure that the refrigerant can fully evaporate in the evaporator 4.

[0059] In some embodiments of the present application, as shown in Figure 1 and Figure 2 The refrigeration system 100 further comprises a refrigeration circuit 8, the refrigeration circuit 8 comprising a refrigeration heat exchanger 81, a refrigeration core 82, and a refrigeration water pump 83, the refrigeration heat exchanger 81 and the refrigeration core 82 being connected to form a circuit, the refrigeration water pump 83 being arranged between the refrigeration heat exchanger 81 and the refrigeration core 82, and being configured to drive the heat exchange medium to flow between the refrigeration heat exchanger 81 and the refrigeration core 82, and the refrigeration heat exchanger 81 being in heat exchange with the evaporator 4. It can be understood that when the refrigeration system 100 is in operation, the liquid refrigerant in the inner space of the liquid storage tank 3 enters the evaporator 4, and the liquid refrigerant in the evaporator 4 exchanges heat with the heat exchange medium in the refrigeration heat exchanger 81, and the refrigerant in the evaporator 4 absorbs heat and changes phase, and the heat exchange medium in the refrigeration heat exchanger 81 releases heat, and the refrigeration water pump 83 drives the heat exchange medium with lower temperature in the refrigeration heat exchanger 81 to flow to the refrigeration core 82, and the refrigeration core 82 can blow cold air to the passenger compartment of the vehicle to meet the refrigeration demand of the passengers. The heat exchange medium in the refrigeration core 82 after heat exchange and temperature rise returns to the refrigeration heat exchanger 81 under the driving of the refrigeration water pump 83, and the heat exchange between the liquid refrigerant in the evaporator 4 and the heat exchange medium in the refrigeration heat exchanger 81 is realized again, and the continuous refrigeration in the passenger compartment is realized.

[0060] In some embodiments of the present application, as shown in Figure 1 and Figure 2 The refrigeration system 100 further comprises a heating circuit 9, the heating circuit 9 comprising a heating heat exchanger 91, a heating core 92, and a heating water pump 93, the heating heat exchanger 91 and the heating core 92 being connected to form a circuit, the heating water pump 93 being arranged between the heating heat exchanger 91 and the heating core 92, and being configured to drive the heat exchange medium to flow between the heating heat exchanger 91 and the heating core 92, and the heating heat exchanger 91 being in heat exchange with the condenser 2. It can be understood that when the refrigeration system 100 is in operation, the high-temperature and high-pressure gaseous refrigerant enters the condenser 2 through the exhaust port 11 of the compressor 1, the high-temperature and high-pressure gaseous refrigerant in the condenser 2 exchanges heat with the heat exchange medium in the heating heat exchanger 91, the refrigerant in the condenser 2 releases heat and changes phase, the heat exchange medium in the heating heat exchanger 91 absorbs heat, the heating water pump 93 drives the heat exchange medium with higher temperature in the heating heat exchanger 91 to flow to the heating core 92, and the heating core 92 can blow hot air to the passenger compartment of the vehicle to meet the heating demand of the passengers. The heat exchange medium in the heating core 92 after heat exchange and temperature drop returns to the heating heat exchanger 91 under the driving of the heating water pump 93, and the heat exchange between the high-temperature and high-pressure gaseous refrigerant in the condenser 2 and the heat exchange medium in the heating heat exchanger 91 is realized again, and the continuous heating in the passenger compartment is realized.

[0061] In the embodiment, the refrigerant is R290, which is a natural refrigerant and has a low GWP (global warming potential) value. R290 is flammable. By introducing the refrigeration circuit 8 and the heating circuit 9 into the refrigeration system 100, the refrigerant and the components of the refrigeration system 100 in which the refrigerant is located do not need to enter the engine compartment of the vehicle, thereby reducing the risk of R290 combustion during vehicle driving.

[0062] In some embodiments of the application, the heat exchange pipe 31 is a serpentine coil. The serpentine coil can increase the heat exchange effect between the liquid refrigerant or gas-liquid mixed refrigerant with a high temperature in the internal space of the liquid storage tank 3 and the gaseous refrigerant or gas-liquid mixed refrigerant with a low temperature in the heat exchange pipe 31. The heat exchange effect is shown in the following table:

[0063]

[0064] Table 1 Heat exchange performance of the liquid storage tank

[0065] As shown in Table 1, when the heat exchange pipe 31 is a serpentine coil, the minimum heat exchange amount is large, and the heat exchange effect is good.

[0066] The control method of the refrigeration system 100 according to the embodiment of the application is as shown in Figure 4 The refrigeration system 100 is the refrigeration system 100 described above. The control method of the refrigeration system 100 includes the following steps:

[0067] The refrigerant pressure P1 flowing into the condenser 2 and the refrigerant pressure P2 flowing out of the evaporator 4 are obtained. P1 corresponds to the refrigerant pressure at the exhaust port 11 of the compressor 1, and P2 corresponds to the refrigerant pressure at the suction port 12 of the compressor 1.

[0068] Whether the compressor 1 meets the starting condition is determined according to the refrigerant pressure P1 and the refrigerant pressure P2. This avoids damage to the compressor 1 caused by forced starting of the compressor 1 when the starting condition is not met, thereby improving the use reliability of the compressor 1.

[0069] If the compressor 1 meets the starting condition, the compressor 1 is controlled to operate at a target speed according to the refrigerant pressure P1 and the refrigerant pressure P2. The refrigeration system 100 can start to work.

[0070] If the compressor 1 does not meet the starting condition, the pressure relief valve 5 is opened to make the compressor 1 meet the starting condition. The high-temperature and high-pressure gaseous refrigerant in the compressor 1 can be discharged to the heat exchange pipe 31 through the first branch 13. The pressure values at the exhaust port 11 and the suction port of the compressor 1 can be adjusted, and the pressure values inside the refrigeration system 100 can be balanced. This avoids the compressor 1 being in an overloading state for a long time, avoids problems such as over-power and over-flow of the compressor 1, avoids causing a failure of the refrigeration system 100, and avoids causing a refrigeration failure of the vehicle.

[0071] The control method of the refrigeration system 100 according to the embodiments of the present application, by connecting one end of the condenser 2 with the exhaust port 11 of the compressor 1, connecting the other end of the condenser 2 with the internal space of the liquid accumulator 3, having the heat exchange pipe 31 in the liquid accumulator 3, connecting one end of the heat exchange pipe 31 with the return port 12 of the compressor 1, connecting one end of the evaporator 4 with the internal space of the liquid accumulator 3, and connecting the other end of the heat exchange pipe 31 with the other end of the evaporator 4. The liquid accumulator 3 can realize heat exchange between the liquid refrigerant or gas-liquid mixed refrigerant with higher temperature in the internal space of the liquid accumulator 3 and the gaseous refrigerant or gas-liquid mixed refrigerant with lower temperature in the heat exchange pipe 31, and improve the heat exchange performance of the liquid refrigerant after entering the evaporator 4. The pressure relief valve 5 is arranged on the first branch 13 connecting the exhaust port 11 of the compressor 1 and the end of the heat exchange pipe 31 away from the return port 12 of the compressor 1. When the pressure of the refrigerant flowing out of the exhaust port 11 of the compressor 1 is too large, the pressure relief valve 5 on the first branch 13 can open the first branch 13, and the compressor 1 can discharge pressure into the heat exchange pipe 31 through the first branch 13, so as to adjust the pressure values at the exhaust port 11 and the intake port of the compressor 1, avoid the compressor 1 being in an overloading state for a long time, avoid the problems of over-power and over-flow of the compressor 1, avoid causing the refrigeration system 100 to malfunction, and avoid causing the refrigeration of the vehicle to fail.

[0072] In some embodiments of the present application, the start-up conditions of the compressor 1 include that the refrigerant pressure P1 and the refrigerant pressure P2 satisfy: 0.1MPa≤P2≤3.2MPa, 0.1MPa≤P1≤0.8MPa, and P1≤P2+2.9 (such as the refrigerant pressure P1 and the refrigerant pressure P2 value range defined by BACDE in Figure 3 ). At this time, the refrigerant pressure P1 at the exhaust port 11 of the compressor 1 and the refrigerant pressure P2 at the return port 12 of the compressor 1 satisfy the start-up requirements of the compressor 1, and the compressor 1 can start working normally.

[0073] In some embodiments of the present application, according to the refrigerant pressure P1 and the refrigerant pressure P2, the control of the compressor 1 to operate at a target speed includes: when the refrigerant pressure P1 and the refrigerant pressure P2 are in the overlapping region defined by three conditions of 0.1MPa≤P2≤1.8MPa, 0.3MPa≤P1≤0.6MPa, and P1≤2*P2+1 (such as the refrigerant pressure P1 and the refrigerant pressure P2 value range defined by BACDE in Figure 3 ), the compressor 1 is controlled to operate at a first target speed; and when the refrigerant pressure P1 and the refrigerant pressure P2 are in the overlapping region defined by three conditions of 0.1MPa≤P2≤3.2MPa, 0.1MPa≤P1≤0.8MPa, and P1≤P2+2.9, and outside the overlapping region defined by three conditions of 0.1MPa≤P2≤1.8MPa, 0.3MPa≤P1≤0.6MPa, and P1≤2*P2+1 (such as the refrigerant pressure P1 and the refrigerant pressure P2 value range defined by BACDE in Figure 3When the refrigerant pressure P1 at the discharge port 11 of the compressor 1 and the refrigerant pressure P2 at the return port 12 of the compressor 1 are within the overlapping region defined by the three conditions of 0.1 MPa≤P2≤1.8 MPa, 0.3 MPa≤P1≤0.6 MPa, and P1≤2*P2+1, the compressor 1 is controlled to operate at a second target rotational speed, where the first target rotational speed is less than the second target rotational speed.

[0074] It can be understood that the rotational speed of the compressor 1 can be changed according to the numerical range of the refrigerant pressure P1 at the discharge port 11 of the compressor 1 and the refrigerant pressure P2 at the return port 12 of the compressor 1, so that the working efficiency of the compressor 1 is always high, and the refrigeration efficiency of the refrigeration system 100 can be increased, thereby increasing the refrigeration or heating efficiency in the passenger compartment.

[0075] Further, the first target rotational speed is 800-3000 rpm. It can be understood that the first target rotational speed can be 800 rpm, 900 rpm, 1000 rpm, 1100 rpm, 1200 rpm, 1300 rpm, 1400 rpm, 1500 rpm, 1600 rpm, 1700 rpm, 1800 rpm, 1900 rpm, 2000 rpm, 2100 rpm, 2200 rpm, 2300 rpm, 2400 rpm, 2500 rpm, 2600 rpm, 2700 rpm, 2800 rpm, 2900 rpm, or 3000 rpm. The first target rotational speed is not less than 800 rpm, which can avoid the rotational speed of the compressor 1 being too low, thereby avoiding low working efficiency of the compressor 1 or damage to the compressor 1. The first target rotational speed is not greater than 3000 rpm, which can avoid the rotational speed of the compressor 1 being too high when the refrigerant pressure P1 and the refrigerant pressure P2 are within the overlapping region defined by the three conditions of 0.1 MPa≤P2≤1.8 MPa, 0.3 MPa≤P1≤0.6 MPa, and P1≤2*P2+1, thereby avoiding waste of the working efficiency of the compressor 1.

[0076] The second target rotating speed is 3000-10000 rpm. It can be understood that the second target rotating speed can be 3000 rpm, 3500 rpm, 4000 rpm, 4500 rpm, 5000 rpm, 5500 rpm, 6000 rpm, 6500 rpm, 7000 rpm, 7500 rpm, 8000 rpm, 8500 rpm, 9000 rpm, 9500 rpm or 10000 rpm. The second target rotating speed is not less than 3000 rpm, which can ensure the compression effect of the compressor 1 and avoid waste of the refrigeration effect of the refrigerant when the refrigerant pressure P1 and the refrigerant pressure P2 are in the overlapping area defined by the three conditions of 0.1 MPa≤P2≤3.2 MPa, 0.1 MPa≤P1≤0.8 MPa and P1≤P2+2.9, and are out of the overlapping area defined by the three conditions of 0.1 MPa≤P2≤1.8 MPa, 0.3 MPa≤P1≤0.6 MPa and P1≤2*P2+1; and the second target rotating speed is not greater than 10000 rpm, which can avoid vibration of the compressor 1 and damage caused by the vibration.

[0077] In some embodiments of the present application, as shown in Figure 4 the refrigeration system 100 is applied to a vehicle, and the control method of the refrigeration system 100 further comprises:

[0078] According to the refrigerant pressure P1, the refrigerant pressure P2 and the demand of the vehicle for the refrigeration capacity of the refrigeration system 100, it is determined whether the refrigeration system 100 is in a stable operation state. The values of the refrigerant pressure P1 at the exhaust port 11 of the compressor 1 and the refrigerant pressure P2 at the return port 12 can be monitored at any time, which can avoid the compressor 1 being in an overload state for a long time during the operation of the refrigeration system 100, avoid problems such as over-power and over-flow of the compressor 1, avoid causing failure of the refrigeration system 100, and avoid causing refrigeration failure of the vehicle.

[0079] When the refrigeration system 100 is in a non-stable operation state, the opening or closing of the pressure relief valve 5 and the opening degree when the pressure relief valve 5 is open can be adjusted, so that the refrigerant pressure P1 at the exhaust port 11 of the compressor 1 and the refrigerant pressure P2 at the return port 12 can be adjusted in time, and the normal operation of the refrigeration system 100 can be ensured.

[0080] In some embodiments of the present application, the stable operation state includes that the refrigerant pressure P1 and the refrigerant pressure P2 simultaneously satisfy 0.1 MPa≤P2≤3.2 MPa, 0.1 MPa≤P1≤0.8 MPa and P1≤P2+2.9 (the refrigerant pressure P1 and the refrigerant pressure P2 are in the value interval defined by BACDE in Figure 3 ). At this time, the refrigerant pressure P1 at the exhaust port 11 of the compressor 1 and the refrigerant pressure P2 at the return port 12 satisfy the stable operation state of the compressor 1, and the compressor 1 can start working normally.

[0081] In some embodiments of the present application, as shown in FIG. 1, when the refrigeration system 100 is in a stable operation state, the control method of the refrigeration system 100 further comprises judging whether the refrigeration system 100 is in an optimal operation interval 10 (as shown in FIG. 1); when the refrigeration system 100 is not in the optimal operation interval 10, adjusting the opening or closing of the pressure relief valve 5 and the opening degree when opened, so that the compressor 1 is in the optimal operation interval 10 of the compressor 1 as much as possible, improving the operation efficiency of the compressor 1, improving the operation efficiency of the refrigeration system 100, and saving the energy consumption of the refrigeration system 100. Figure 4 Figure 3 In some embodiments of the present application, as shown in FIG. 1, when the refrigeration system 100 is in a stable operation state, the control method of the refrigeration system 100 further comprises judging whether the refrigeration system 100 is in an optimal operation interval 10 (as shown in FIG. 1); when the refrigeration system 100 is not in the optimal operation interval 10, adjusting the opening or closing of the pressure relief valve 5 and the opening degree when opened, so that the compressor 1 is in the optimal operation interval 10 of the compressor 1 as much as possible, improving the operation efficiency of the compressor 1, improving the operation efficiency of the refrigeration system 100, and saving the energy consumption of the refrigeration system 100.

[0082] In some embodiments of the present application, the optimal operation interval 10 includes that the rotation speed of the compressor 1 is 3000-5000 rpm. It can be understood that the rotation speed of the compressor 1 in the optimal operation interval 10 can be 3000 rpm, 3100 rpm, 3200 rpm, 3300 rpm, 3400 rpm, 3500 rpm, 3600 rpm, 3700 rpm, 3800 rpm, 3900 rpm, 4000 rpm, 4100 rpm, 4200 rpm, 4300 rpm, 4400 rpm, 4500 rpm, 4600 rpm, 4700 rpm, 4800 rpm, 4900 rpm or 5000 rpm. The rotation speed of the compressor 1 in the optimal operation interval 10 is not less than 3000 rpm, which can ensure the compression effect of the compressor 1 and avoid wasting the refrigeration effect of the refrigerant; the rotation speed of the compressor 1 in the optimal operation interval 10 is not more than 5000 rpm, which can avoid the vibration of the compressor 1 and avoid damage caused by the vibration of the compressor 1.

[0083] Other configurations and operations of the refrigeration system 100 and the control method of the refrigeration system 100 according to the embodiments of the present application are known to those skilled in the art, and will not be described in detail herein.

[0084] In the description of the present specification, the description of the terms "one embodiment", "some embodiments", "exemplary embodiment", "example", "specific example", or "some examples" means that the specific features, structures, materials or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present application. In the present specification, the exemplary description of the above terms does not necessarily mean the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0085] ​While embodiments of the application have been shown and described, it is to be understood that the embodiments described are merely divergences of the principles and application of the present application and that numerous modifications, changes, substitutions, and alterations can be made thereto without departing from the spirit and scope of the present application, which is defined by the following claims and their equivalents.

Claims

1. A refrigeration system, characterized in that, For use in vehicles and including: compressor; A condenser, one end of which is connected to the exhaust port of the compressor; The liquid storage tank has one end connected to the internal space of the condenser, and the liquid storage tank has a heat exchange tube, one end of which is connected to the return port of the compressor. An evaporator, one end of which is connected to the internal space of the liquid storage tank, and the other end of which is connected to the other end of the heat exchange tube; The first branch connects the exhaust port of the compressor to the end of the heat exchange tube opposite to the return port of the compressor. A pressure relief valve is provided on the first branch.

2. The refrigeration system according to claim 1, characterized in that, Also includes: A first sensor is used to detect the temperature and pressure of the refrigerant flowing from the compressor exhaust port to the condenser.

3. The refrigeration system according to claim 2, characterized in that, The compressor's exhaust port and the condenser are connected via a second branch, and the first sensor is located on the second branch.

4. The refrigeration system according to claim 1, characterized in that, Also includes: A second sensor is used to detect the pressure of the refrigerant flowing from the evaporator to the heat exchange tube.

5. The refrigeration system according to claim 4, characterized in that, The evaporator and the heat exchange tube are connected by a third branch, and the second sensor is located on the third branch.

6. The refrigeration system according to claim 1, characterized in that, Also includes: An expansion valve is provided between the liquid storage tank and the evaporator.

7. The refrigeration system according to claim 1, characterized in that, It also includes a refrigeration circuit, which includes: The system includes a refrigeration heat exchanger, a refrigeration core, and a refrigeration water pump. The refrigeration heat exchanger and the refrigeration core are connected to form a circuit. The refrigeration water pump is located between the refrigeration heat exchanger and the refrigeration core and is used to drive the heat exchange medium to circulate between the refrigeration heat exchanger and the refrigeration core. The refrigeration heat exchanger exchanges heat with the evaporator.

8. The refrigeration system according to claim 1, characterized in that, It also includes a heating circuit, which includes: The system includes a heating heat exchanger, a heating core, and a hot water pump. The heating heat exchanger and the heating core are connected to form a circuit. The hot water pump is located between the heating heat exchanger and the heating core and is used to drive the heat exchange medium to circulate between the heating heat exchanger and the heating core. The heating heat exchanger exchanges heat with the condenser.

9. A control method for a refrigeration system, characterized in that, The refrigeration system is the refrigeration system according to any one of claims 1-8, and the control method of the refrigeration system includes: Obtain the refrigerant pressure P1 flowing into the condenser and the refrigerant pressure P2 flowing out of the evaporator; Determine whether the compressor meets the start-up conditions based on refrigerant pressure P1 and refrigerant pressure P2; If the compressor meets the start-up conditions, the compressor is controlled to run at the target speed according to the refrigerant pressure P1 and refrigerant pressure P2; If the compressor does not meet the starting conditions, the pressure relief valve is opened to enable the compressor to meet the starting conditions.

10. The control method for the refrigeration system according to claim 9, characterized in that, The compressor's start-up conditions include: The refrigerant pressures P1 and P2 simultaneously satisfy the following conditions: 0.1MPa≤P2≤3.2MPa, 0.1MPa≤P1≤0.8MPa, and P1≤P2+2.

9.

11. The control method for the refrigeration system according to claim 9, characterized in that, The step of controlling the compressor to operate at the target speed based on refrigerant pressure P1 and refrigerant pressure P2 includes: When the refrigerant pressures P1 and P2 are within the overlapping range defined by the three conditions 0.1MPa≤P2≤1.8MPa, 0.3MPa≤P1≤0.6MPa, and P1≤2*P2+1, the compressor is controlled to operate at the first target speed. When refrigerant pressures P1 and P2 are within the overlapping range defined by the three conditions 0.1MPa≤P2≤3.2MPa, 0.1MPa≤P1≤0.8MPa, and P1≤P2+2.9, and outside the overlapping range defined by the three conditions 0.1MPa≤P2≤1.8MPa, 0.3MPa≤P1≤0.6MPa, and P1≤2*P2+1, the compressor is controlled to operate at a second target speed, wherein the first target speed is less than the second target speed.

12. The control method for the refrigeration system according to claim 11, characterized in that, The first target speed is 800-3000 rpm; And / or, the second target speed is 3000-10000 rpm.

13. The control method for the refrigeration system according to claim 9, characterized in that, The refrigeration system is applied to a vehicle, and the control method for the refrigeration system further includes: Based on refrigerant pressure P1, refrigerant pressure P2, and the vehicle's demand for cooling capacity, determine whether the refrigeration system is in a stable operating state. When the refrigeration system is in an unstable operating state, adjust the opening or closing of the pressure relief valve and the opening degree when it is open.

14. The control method for the refrigeration system according to claim 13, characterized in that, The stable operating state includes the following conditions: refrigerant pressure P1 and refrigerant pressure P2 simultaneously satisfy: 0.1MPa≤P2≤3.2MPa, 0.1MPa≤P1≤0.8MPa, P1≤P2+2.

9.

15. The control method for the refrigeration system according to claim 13, characterized in that, When the refrigeration system is in a stable operating state, the refrigeration system control method further includes: Determine whether the refrigeration system is in its optimal operating range; When the refrigeration system is not in its optimal operating range, adjust the opening or closing of the pressure relief valve and the degree of opening when it is open.

16. The control method for the refrigeration system according to claim 15, characterized in that, The optimal operating range includes a compressor speed of 3000-5000 rpm.

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