Refrigerating system and control method of refrigerating system

Abstract

The invention discloses a refrigerating system and a control method of the refrigerating system. The refrigerating system is used for a vehicle and comprises a compressor, a condenser, a liquid storage tank, an evaporator, a first branch and a pressure release valve. One end of the condenser is communicated with an exhaust port of the compressor; the other end of the condenser communicates with the inner space of the liquid storage tank, a heat exchange pipe is arranged in the liquid storage tank, and one end of the heat exchange pipe communicates with an air return opening of the compressor. One end of the evaporator is communicated with the internal space of the liquid storage tank, and the other end is communicated with the other end of the heat exchange tube; the first branch is connected with an exhaust port of the compressor and one end, deviating from an air return port of the compressor, of the heat exchange tube; and the pressure release valve is arranged on the first branch. According to the refrigerating system, when the pressure of the refrigerant flowing out of the exhaust port of the compressor is too large, the pressure values of the exhaust port and the air inlet of the compressor can be adjusted, the situation that the compressor is in an overload state for a long time is avoided, refrigerating system faults are avoided, and refrigerating failure of a vehicle is avoided.

Description

Technical Field

[0001] The present invention mainly relates to the technical field of refrigeration systems, and in particular to a refrigeration system and a control method for the refrigeration system. Background Art

[0002] In the prior art, the compressor of the vehicle's refrigeration system can compress and boost the refrigerant, but there is a lack of protection measures for the high-pressure gas discharged by the compressor to the condenser. When the pressure difference of the compressor is large, it is easy for the compressor to be in an overloaded state for a long time, which will cause the compressor to have problems such as overpower and overcurrent, and then cause the refrigeration system to fail, causing the vehicle to stop cooling or heating. Summary of the invention

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

[0004] The present invention further provides a control method for a refrigeration system, wherein the refrigeration system in the control method for a refrigeration system is the refrigeration system described above.

[0005] The refrigeration system according to an embodiment of the present invention is used for a vehicle and includes a compressor, a condenser, a liquid storage tank, an evaporator, a first branch and a pressure relief valve. One end of the condenser is connected to the exhaust port of the compressor; the other end of the condenser is connected to the internal space of the liquid storage tank, and the liquid storage tank has a heat exchange tube, one end of the heat exchange tube is connected to the return air port of the compressor; one end of the evaporator is connected to the internal space of the liquid storage tank, and the other end is connected to the other end of the heat exchange tube; the first branch connects the exhaust port of the compressor and the end of the heat exchange tube away from the return air port of the compressor; the pressure relief valve is arranged on the first branch.

[0006] According to the refrigeration system of the embodiment of the present invention, one end of the condenser is connected to the exhaust port of the compressor, the other end of the condenser is connected to the internal space of the liquid storage tank, a heat exchange tube is provided in the liquid storage tank, one end of the heat exchange tube is connected to the return air port of the compressor, one end of the evaporator is connected to the internal space of the liquid storage tank, and the other end is connected to the other end of the heat exchange tube. The liquid storage tank can achieve heat exchange between the liquid refrigerant or gas-liquid mixed refrigerant with a higher temperature in the internal space of the liquid storage tank and the gaseous refrigerant or gas-liquid mixed refrigerant with a lower temperature in the heat exchange tube, thereby improving 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 tube 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 relieve pressure into the heat exchange tube through the first branch. The pressure values ​​at the exhaust port and the air inlet of the compressor can be adjusted to avoid the compressor being in an overloaded state for a long time, to avoid problems such as overpower and overcurrent in the compressor, to avoid causing refrigeration system failure, and to avoid causing refrigeration failure of the vehicle.

[0007] In some embodiments of the present invention, the refrigeration system further includes a first sensor, and the first sensor is used to detect the temperature and pressure of the refrigerant flowing from the compressor exhaust port to the condenser.

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

[0009] In some embodiments of the present invention, the refrigeration system further includes a second sensor, and the second sensor is used to detect the pressure of the refrigerant flowing from the evaporator to the heat exchange tube.

[0010] In some embodiments of the present invention, the evaporator and the heat exchange tube are connected via a third branch, and the second sensor is disposed on the third branch.

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

[0012] In some embodiments of the present invention, the refrigeration system also includes a refrigeration circuit, which 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 arranged between the refrigeration heat exchanger and the refrigeration core to drive the heat exchange medium to circulate between the refrigeration heat exchanger and the refrigeration core, and the refrigeration heat exchanger and the evaporator exchange heat.

[0013] In some embodiments of the present invention, the refrigeration system also includes a heating circuit, which 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 arranged between the heating heat exchanger and the heating core to drive the heat exchange medium to circulate between the heating heat exchanger and the heating core, and the heating heat exchanger and the condenser exchange heat.

[0014] According to the control method of the refrigeration system of an embodiment of the present invention, the refrigeration system is the above-mentioned refrigeration system, and the control method of the refrigeration system includes: obtaining the refrigerant pressure P1 flowing into the condenser and the refrigerant pressure P2 flowing out of the evaporator; judging whether the compressor meets the starting conditions according to the refrigerant pressure P1 and the refrigerant pressure P2; if the compressor meets the starting conditions, controlling the compressor to run at a target speed according to the refrigerant pressure P1 and the refrigerant pressure P2; if the compressor does not meet the starting conditions, opening the pressure relief valve to make the compressor meet the starting conditions.

[0015] According to the control method of the refrigeration system of the embodiment of the present invention, one end of the condenser is connected to the exhaust port of the compressor, the other end of the condenser is connected to the internal space of the liquid storage tank, a heat exchange tube is provided in the liquid storage tank, one end of the heat exchange tube is connected to the return air port of the compressor, one end of the evaporator is connected to the internal space of the liquid storage tank, and the other end is connected to the other end of the heat exchange tube. The liquid storage tank can realize the heat exchange between the liquid refrigerant or gas-liquid mixed refrigerant with a higher temperature in the internal space of the liquid storage tank and the gaseous refrigerant or gas-liquid mixed refrigerant with a lower temperature in the heat exchange tube, thereby improving 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 tube 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 relieve pressure into the heat exchange tube through the first branch. The pressure values ​​at the exhaust port and the air inlet of the compressor can be adjusted to avoid the compressor being in an overloaded state for a long time, to avoid problems such as overpower and overcurrent in the compressor, to avoid causing refrigeration system failure, and to avoid causing refrigeration failure of the vehicle.

[0016] In some embodiments of the present invention, the start-up conditions of the compressor include the refrigerant pressure P1 and the refrigerant pressure P2 simultaneously satisfying: 0.1 MPa≤P2≤3.2 MPa, 0.1 MPa≤P1≤0.8 MPa, P1≤P2+2.9.

[0017] In some embodiments of the present invention, controlling the compressor to operate at a target speed according to the refrigerant pressure P1 and the refrigerant pressure P2 includes:

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

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

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

[0021] According to the refrigerant pressure P1, the refrigerant pressure P2 and the vehicle's demand for the refrigeration system's 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 opened.

[0022] In some embodiments of the present invention, the stable operating state includes: 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, P1≤P2+2.9.

[0023] In some embodiments of the present invention, when the refrigeration system is in a stable operating state, the refrigeration system control method further includes:

[0024] Determine whether the refrigeration system is in an optimal operating range; when the refrigeration system is not in the optimal operating range, adjust the opening or closing of the pressure relief valve and the opening degree of the pressure relief valve when it is opened.

[0025] In some embodiments of the present invention, the optimal operating range includes: the rotation speed of the compressor is 3000-5000 rpm.

[0026] Additional aspects and advantages of the present invention will be given in part in the following description and in part will be obvious from the following description, or will be learned through practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] The above and / or additional aspects and advantages of the present invention will become apparent and easily understood from the description of the embodiments in conjunction with the following drawings, in which:

[0028] Figure 1 is a schematic diagram of a first branch opened by a pressure relief valve of a refrigeration system according to an embodiment of the present invention;

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

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

[0031] Figure 4 is a flow chart of a control method for a refrigeration system according to an embodiment of the present invention.

[0032] Reference numerals:

[0033] 100. Refrigeration system;

[0034] 1. Compressor; 11. Exhaust port; 12. Air return port; 13. First branch;

[0035] 2. Condenser;

[0036] 3. Liquid storage tank; 31. Heat exchange tube;

[0037] 4. Evaporator; 41. Expansion valve;

[0038] 5. Pressure relief valve;

[0039] 6. First sensor; 61. Second branch;

[0040] 7. Second sensor; 71. Third branch;

[0041] 8. Refrigeration circuit; 81. Refrigeration heat exchanger; 82. Refrigeration core; 83. Refrigeration water pump;

[0042] 9. Heating circuit; 91. Heating heat exchanger; 92. Heating core; 93. Heating water pump;

[0043] 10. Optimal operating range. DETAILED DESCRIPTION

[0044] Embodiments of the present invention are described in detail below, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and cannot be understood as limiting the present invention.

[0045] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, 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 therefore cannot be understood as a limitation on the present invention. In addition, features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, unless otherwise specified, "multiple" means two or more.

[0046] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0047] Reference below Figure 1-Figure 2 A refrigeration system 100 according to an embodiment of the present invention is described.

[0048] like Figure 1 As shown, a refrigeration system 100 according to an embodiment of the present invention includes a compressor 1, a condenser 2, a liquid storage tank 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 connected to the exhaust port 11 of the compressor 1, and the other end of the condenser 2 is connected to the internal space of the liquid storage tank 3. The liquid storage tank 3 has a heat exchange tube 31, and one end of the heat exchange tube 31 is connected to the return air port 12 of the compressor 1. One end of the evaporator 4 is connected to the internal space of the liquid storage tank 3, and the other end is connected to the other end of the heat exchange tube 31. It can be understood that when the refrigeration system 100 is working, 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, and the refrigerant in the evaporator 4 absorbs heat and changes phase. After the phase change, the gaseous refrigerant or gas-liquid mixed refrigerant with a lower temperature enters the heat exchange tube 31 and exchanges heat with the liquid refrigerant with a higher temperature in the internal space of the liquid storage tank 3. The temperature of the gaseous refrigerant or gas-liquid mixed refrigerant in the heat exchange tube 31 can be increased, and the refrigerant in the heat exchange tube 31 is promoted to be converted into gaseous refrigerant, and the temperature of the liquid refrigerant in the liquid storage tank 3 is increased, so that the temperature of the liquid refrigerant entering the evaporator 4 is higher, which is convenient for the liquid in the evaporator 4 to exchange heat with the external environment.

[0050] like Figure 1 and Figure 2 As shown, the gaseous refrigerant in the heat exchange tube 31 flows out and enters the return air port 12 of the compressor 1, and the gaseous refrigerant is compressed into a high-temperature and high-pressure gaseous refrigerant in the compressor 1, and the high-temperature and high-pressure gaseous refrigerant enters the condenser 2 through the exhaust port 11 of the compressor 1, and the high-temperature and high-pressure gaseous refrigerant in the condenser 2 exchanges heat with the external environment, and the gaseous refrigerant in the condenser 2 releases heat and changes phase. After the phase change, the liquid refrigerant or gas-liquid mixed refrigerant with a higher temperature enters the internal space of the liquid storage tank 3, and exchanges heat with the gaseous refrigerant or gas-liquid mixed refrigerant with a lower temperature in the heat exchange tube 31, thereby realizing the circulation of the refrigeration system 100. The liquid storage tank 3 can realize heat exchange between the liquid refrigerant or gas-liquid mixed refrigerant with a higher temperature in the internal space of the liquid storage tank 3 and the gaseous refrigerant or gas-liquid mixed refrigerant with a lower temperature in the heat exchange tube 31. It can perform secondary cooling on the liquid refrigerant or gas-liquid mixed refrigerant that enters the internal space of the liquid storage tank 3 after flowing out of the condenser 2, thereby improving the heat exchange performance of the liquid refrigerant after entering the evaporator 4.

[0051] like Figure 1 and Figure 2As shown, the first branch 13 connects the exhaust port 11 of the compressor 1 and the end of the heat exchange tube 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 depressurized into the heat exchange tube 31 through the first branch 13. The pressure values ​​at the exhaust port 11 and the air inlet of the compressor 1 can be adjusted, and the pressure value inside the refrigeration system 100 can be balanced, so as to avoid the compressor 1 being in an overloaded state for a long time, avoid problems such as overpower and overcurrent in the compressor 1, avoid causing malfunctions of the refrigeration system 100, and avoid causing refrigeration failure of the vehicle.

[0052] According to the refrigeration system 100 of the embodiment of the present invention, one end of the condenser 2 is connected to the exhaust port 11 of the compressor 1, and the other end of the condenser 2 is connected to the internal space of the liquid storage tank 3. The liquid storage tank 3 has a heat exchange tube 31, one end of the heat exchange tube 31 is connected to the return air port 12 of the compressor 1, and one end of the evaporator 4 is connected to the internal space of the liquid storage tank 3, and the other end is connected to the other end of the heat exchange tube 31. The liquid storage tank 3 can achieve heat exchange between the liquid refrigerant or gas-liquid mixed refrigerant with a higher temperature in the internal space of the liquid storage tank 3 and the gaseous refrigerant or gas-liquid mixed refrigerant with a lower temperature in the heat exchange tube 31, thereby improving 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 tube 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 relieve pressure into the heat exchange tube 31 through the first branch 13. The pressure values ​​at the exhaust port 11 and the air inlet of the compressor 1 can be adjusted to avoid the compressor 1 being in an overload state for a long time, to avoid problems such as overpower and overcurrent in the compressor 1, to avoid causing malfunctions of the refrigeration system 100, and to avoid causing refrigeration failure of the vehicle.

[0053] In some embodiments of the present invention, Figure 1 and Figure 2 As shown, the refrigeration system 100 also includes 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. The first sensor 6 can transmit a signal to the controller of the refrigeration system 100 when it detects that the temperature of the refrigerant flowing from the exhaust port 11 of the compressor 1 to the condenser 2 is too high, so as to realize the timely shutdown of the compressor 1 and avoid the failure of the compressor 1. At the same time, the first sensor 6 can transmit a signal to the controller of the refrigeration system 100 when it detects that 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, so as to realize the timely shutdown of the compressor 1 and avoid the failure of the compressor 1.

[0054] Furthermore, if Figure 1 and Figure 2 As shown, the exhaust port 11 of the compressor 1 and the condenser 2 are connected via a second branch 61, and the first sensor 6 is disposed on the second branch 61. The first sensor 6 can conveniently detect the temperature and pressure of the refrigerant flowing from the exhaust port 11 of the compressor 1 to the condenser 2, and transmit a signal to the controller of the refrigeration system 100 when the pressure and temperature are abnormal, thereby realizing the timely shutdown of the compressor 1 and avoiding failure of the compressor 1.

[0055] In some embodiments of the present invention, Figure 1 and Figure 2 As shown, the refrigeration system 100 further 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. The second sensor 7 can transmit a signal to the controller of the refrigeration system 100 when detecting that the pressure of the refrigerant flowing from the evaporator 4 to the heat exchange tube 31 is too high or too low, so as to realize the timely shutdown of the compressor 1 and avoid the failure of the compressor 1.

[0056] Furthermore, if Figure 1 and Figure 2 As shown, the evaporator 4 and the heat exchange tube 31 are connected via a third branch 71, the second sensor 7 is disposed on the third branch 71, and the first sensor 6 can more conveniently detect the pressure of the refrigerant flowing from the evaporator 4 to the heat exchange tube 31, and transmit a signal to the controller of the refrigeration system 100 when the pressure is abnormal, so as to realize the timely shutdown of the compressor 1 and avoid failure of the compressor 1.

[0057] In some embodiments of the present invention, Figure 1 and Figure 2 As shown, the refrigeration system 100 further includes an expansion valve 41, which is disposed between the liquid storage tank 3 and the evaporator 4. It is understandable that the gaseous refrigerant flowing out of the evaporator 4 enters the compressor 1 and is compressed into a high-temperature and high-pressure gaseous refrigerant in the compressor 1. The high-temperature and high-pressure gaseous refrigerant enters the condenser 2 to release heat and phase-change into a high-pressure liquid refrigerant. The high-pressure liquid refrigerant enters the expansion valve 41 and is throttled and depressurized, so that the refrigerant becomes a low-pressure wet steam when it flows out of the expansion valve 41, ensuring that the refrigerant can be fully evaporated in 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 obtaining 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' at the refrigerant pressure P flowing out of the evaporator 4, 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 be fully evaporated in the evaporator 4.

[0059] In some embodiments of the present invention, Figure 1 and Figure 2 As shown, the refrigeration system 100 also includes a refrigeration circuit 8, which includes 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 are connected to form a circuit. The refrigeration water pump 83 is arranged between the refrigeration heat exchanger 81 and the refrigeration core 82, and is used to drive the heat exchange medium to circulate between the refrigeration heat exchanger 81 and the refrigeration core 82, and the refrigeration heat exchanger 81 exchanges heat with the evaporator 4. It can be understood that when the refrigeration system 100 is working, the liquid refrigerant in the internal space of the liquid storage tank 3 enters the evaporator 4, and the liquid refrigerant exchanges heat with the heat exchange medium in the refrigeration heat exchanger 81 in the evaporator 4. The refrigerant in the evaporator 4 absorbs heat and changes phase, and the heat exchange medium in the refrigeration heat exchanger 81 dissipates heat. The refrigeration water pump 83 drives the heat exchange medium with a 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 needs of the passengers. The heat exchange medium heated up after heat exchange in the refrigeration core 82 is driven by the refrigeration water pump 83 to return to the refrigeration heat exchanger 81, and the liquid refrigerant in the evaporator 4 and the heat exchange medium in the refrigeration heat exchanger 81 are exchanged again to achieve continuous cooling in the passenger compartment.

[0060] In some embodiments of the present invention, Figure 1 and Figure 2 As shown, the refrigeration system 100 also includes a heating circuit 9, which includes a heating heat exchanger 91, a heating core 92 and a hot water pump 93. The heating heat exchanger 91 and the heating core 92 are connected to form a circuit. The hot water pump 93 is arranged between the heating heat exchanger 91 and the heating core 92 to drive the heat exchange medium to circulate between the heating heat exchanger 91 and the heating core 92, and the heating heat exchanger 91 exchanges heat with the condenser 2. It is understandable that when the refrigeration system 100 is working, the high-temperature and high-pressure gaseous refrigerant enters the condenser 2 through the exhaust port 11 of the compressor 1, and 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, and the heat exchange medium in the heating heat exchanger 91 absorbs heat. The hot water pump 93 drives the heat exchange medium with a higher temperature in the heating heat exchanger 91 to flow toward the heating core 92, and the heating core 92 can blow hot air to the passenger compartment of the vehicle to meet the heating needs of the passengers. The heat exchange medium that has been cooled down after heat exchange in the heating core 92 returns to the heating heat exchanger 91 under the drive of the hot water pump 93, and the high-temperature and high-pressure gaseous refrigerant in the condenser 2 and the heat exchange medium in the heating heat exchanger 91 are exchanged again to achieve continuous heating in the passenger compartment.

[0061] In this embodiment, the refrigerant is R290, which is a natural refrigerant with a low GWP (global warming potential) value. R290 is relatively 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 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 present invention, the heat exchange tube 31 is a serpentine coil, which can increase the heat exchange effect between the liquid refrigerant or gas-liquid mixed refrigerant with a higher temperature in the internal space of the liquid storage tank 3 and the gas refrigerant or gas-liquid mixed refrigerant with a lower temperature in the heat exchange tube 31. The heat exchange effect is shown in the following table:

[0063]

[0064] Table 1 Heat transfer performance of liquid storage tank

[0065] As shown in Table 1, when the heat exchange tube 31 is a serpentine coil, the minimum heat exchange capacity is larger and the heat exchange effect is better.

[0066] According to the control method of the refrigeration system 100 of the embodiment of the present invention, Figure 4 As shown, the refrigeration system 100 is the above-mentioned refrigeration system 100, and the control method of the refrigeration system 100 includes the following:

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

[0068] Whether the compressor 1 meets the starting conditions is determined according to the refrigerant pressure P1 and the refrigerant pressure P2, so as to avoid damage to the compressor 1 caused by forced starting when the starting conditions are not met, thereby improving the reliability of the compressor 1.

[0069] If the compressor 1 meets the start-up conditions, the compressor 1 is controlled to run at a target speed according to the refrigerant pressure P1 and the refrigerant pressure P2, and the refrigeration system 100 can start working.

[0070] If the compressor 1 does not meet the starting conditions, the pressure relief valve 5 is opened to make the compressor 1 meet the starting conditions. The high-temperature and high-pressure gaseous refrigerant in the compressor 1 can be depressurized into the heat exchange tube 31 through the first branch 13, and the pressure values ​​at the exhaust port 11 and the air inlet of the compressor 1 can be adjusted. The pressure value inside the refrigeration system 100 can be balanced, thereby preventing the compressor 1 from being in an overloaded state for a long time, preventing the compressor 1 from having problems such as overpower and overcurrent, preventing the refrigeration system 100 from malfunctioning, and preventing the vehicle's refrigeration from failing.

[0071] According to the control method of the refrigeration system 100 of the embodiment of the present invention, one end of the condenser 2 is connected to the exhaust port 11 of the compressor 1, and the other end of the condenser 2 is connected to the internal space of the liquid storage tank 3. The liquid storage tank 3 has a heat exchange tube 31, and one end of the heat exchange tube 31 is connected to the return air port 12 of the compressor 1. One end of the evaporator 4 is connected to the internal space of the liquid storage tank 3, and the other end is connected to the other end of the heat exchange tube 31. The liquid storage tank 3 can realize the 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 tube 31, thereby improving 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 tube 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 relieve pressure into the heat exchange tube 31 through the first branch 13. The pressure values ​​at the exhaust port 11 and the air inlet of the compressor 1 can be adjusted to avoid the compressor 1 being in an overload state for a long time, to avoid problems such as overpower and overcurrent in the compressor 1, to avoid causing malfunctions of the refrigeration system 100, and to avoid causing refrigeration failure of the vehicle.

[0072] In some embodiments of the present invention, the start-up conditions of the compressor 1 include that 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 (such as 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 meet the startup requirements of the compressor 1, and the compressor 1 can start working normally.

[0073] In some embodiments of the present invention, according to the refrigerant pressure P1 and the refrigerant pressure P2, controlling the compressor 1 to operate at the target speed includes: the refrigerant pressure P1 and the refrigerant pressure P2 are in the overlapping area defined by the three conditions of 0.1MPa≤P2≤1.8MPa, 0.3MPa≤P1≤0.6MPa, and P1≤2*P2+1 (such as Figure 3 When the refrigerant pressure P1 and the refrigerant pressure P2 are within the value range of the refrigerant pressure P1 and the refrigerant pressure P2 defined by the BACDE in , the compressor 1 is controlled to run at the first target speed; the refrigerant pressure P1 and the refrigerant pressure P2 are within the overlapping area defined by the three conditions of 0.1MPa≤P2≤3.2MPa, 0.1MPa≤P1≤0.8MPa, and P1≤P2+2.9, and are outside the overlapping area defined by the three conditions of 0.1MPa≤P2≤1.8MPa, 0.3MPa≤P1≤0.6MPa, and P1≤2*P2+1 (such as Figure 3When the refrigerant pressure P1 and the refrigerant pressure P2 are within the BACDE in and the value interval of the refrigerant pressure P2 defined by UFGHV, the compressor 1 is controlled to operate at the second target speed, wherein the first target speed is less than the second target speed.

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

[0075] Further, the first target speed is 800-3000rpm. It can be understood that the first target speed can be 800rpm, 900rpm, 1000rpm, 1100rpm, 1200rpm, 1300rpm, 1400rpm, 1500rpm, 1600rpm, 1700rpm, 1800rpm, 1900rpm, 2000rpm, 2100rpm, 2200rpm, 2300rpm, 2400rpm, 2500rpm, 2600rpm, 2700rpm, 2800rpm, 2900rpm or 3000rpm. The first target speed is not less than 800 rpm, which can prevent the speed of compressor 1 from being too low, thereby preventing the working efficiency of compressor 1 from being low or causing damage to compressor 1; the first target speed is not greater than 3000 rpm, 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≤1.8 MPa, 0.3 MPa≤P1≤0.6 MPa, and P1≤2*P2+1, the speed of compressor 1 is prevented from being too high, thereby preventing the working efficiency of compressor 1 from being wasted.

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

[0077] In some embodiments of the present invention, Figure 4 As shown, the refrigeration system 100 is applied to a vehicle, and the control method of the refrigeration system 100 further includes:

[0078] According to the refrigerant pressure P1, the refrigerant pressure P2 and the vehicle's demand for the cooling capacity of the refrigeration system 100, it is determined whether the refrigeration system 100 is in a stable operating 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. This can prevent the compressor 1 from being in an overload state for a long time during the operation of the refrigeration system 100, avoid problems such as overpower and overcurrent in the compressor 1, avoid causing malfunctions of the refrigeration system 100, and avoid causing refrigeration failure of the vehicle.

[0079] When the refrigeration system 100 is in an unstable operating state, by adjusting the opening or closing of the pressure relief valve 5 and the opening degree when it is opened, 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 to ensure the normal operation of the refrigeration system 100.

[0080] In some embodiments of the present invention, the stable operation state includes the refrigerant pressure P1 and the refrigerant pressure P2 satisfying the following conditions: 0.1 MPa ≤ P2 ≤ 3.2 MPa, 0.1 MPa ≤ P1 ≤ 0.8 MPa, P1 ≤ P2 + 2.9 (e.g. 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 meet the stable operation state of the compressor 1, and the compressor 1 can start working normally.

[0081] In some embodiments of the present invention, Figure 4 As shown, when the refrigeration system 100 is in a stable operating state, the refrigeration system 100 control method further includes determining whether the refrigeration system 100 is in an optimal operating range 10 (such as Figure 3 When the refrigeration system 100 is not in the optimal operating range 10, the opening or closing of the pressure relief valve 5 and the opening degree when it is opened are adjusted so that the compressor 1 is in the optimal operating range 10 of the compressor 1 as much as possible, thereby improving the operating efficiency of the compressor 1, improving the operating efficiency of the refrigeration system 100, and saving the energy consumption of the refrigeration system 100.

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

[0083] Other structures and operations of the refrigeration system 100 and the control method of the refrigeration system 100 according to the embodiment of the present invention are known to those skilled in the art and will not be described in detail here.

[0084] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "illustrative embodiments", "examples", "specific examples", or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner.

[0085] Although the embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the claims and their equivalents.

Claims

1. A refrigeration system, characterized in that: For vehicles and including: compressor; A condenser, one end of which is connected to the exhaust port of the compressor; A liquid storage tank, wherein the other end of the condenser is in communication with the inner space of the liquid storage tank, and a heat exchange tube is provided in the liquid storage tank, and one end of the heat exchange tube is in communication with the return air port of the compressor; an evaporator, one end of the evaporator being in communication with the inner space of the liquid storage tank, and the other end of the evaporator being in communication with the other end of the heat exchange tube; A first branch, the first branch connecting the exhaust port of the compressor and an end of the heat exchange tube away from 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 exhaust port of the compressor and the condenser are connected via a second branch, and the first sensor is arranged 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 via a third branch, and the second sensor is arranged 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: Also included is a refrigeration circuit, the refrigeration circuit comprising: A refrigeration heat exchanger, a refrigeration core and a refrigeration water pump, wherein the refrigeration heat exchanger and the refrigeration core are connected to form a loop, and the refrigeration water pump is arranged between the refrigeration heat exchanger and the refrigeration core to drive the heat exchange medium to circulate between the refrigeration heat exchanger and the refrigeration core, and the refrigeration heat exchanger and the evaporator exchange heat.

8. The refrigeration system according to claim 1, characterized in that: Also included is a heating circuit, the heating circuit comprising: A heating heat exchanger, a heating core and a hot water pump, wherein the heating heat exchanger and the heating core are connected to form a loop, and the hot water pump is arranged between the heating heat exchanger and the heating core to drive the heat exchange medium to circulate between the heating heat exchanger and the heating core, and the heating heat exchanger and the condenser exchange heat.

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

10. The control method of the refrigeration system according to claim 9, characterized in that: The starting conditions of the compressor include: 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.

11. The control method of a refrigeration system according to claim 9, characterized in that: According to the refrigerant pressure P1 and the refrigerant pressure P2, controlling the compressor to operate at a target speed includes: When the refrigerant pressure P1 and the refrigerant pressure P2 are in the overlapping region defined by the three conditions of 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 the refrigerant pressure P1 and the refrigerant pressure P2 are within the overlapping area defined by the three conditions of 0.1MPa≤P2≤3.2MPa, 0.1MPa≤P1≤0.8MPa, and P1≤P2+2.9, and outside the overlapping area defined by the three conditions of 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 of the refrigeration system according to claim 11, characterized in that: The first target speed is 800-3000rpm; And / or, the second target rotation speed is 3000-10000 rpm.

13. The control method of a refrigeration system according to claim 9, characterized in that: The refrigeration system is applied to a vehicle, and the control method of the refrigeration system further includes: According to the refrigerant pressure P1, the refrigerant pressure P2 and the vehicle's demand for the refrigeration capacity of the refrigeration system, determining whether the refrigeration system is in a stable operating state; When the refrigeration system is in an unstable operating state, the opening or closing of the pressure relief valve and the opening degree of the pressure relief valve when the pressure relief valve is opened are adjusted.

14. The control method of the refrigeration system according to claim 13, characterized in that: The stable operating state includes: 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.

15. The control method of a 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: Determining whether the refrigeration system is in an optimal operating range; When the refrigeration system is not in the optimal operating range, the opening or closing of the pressure relief valve and the opening degree of the pressure relief valve when opened are adjusted.

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

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