A liquid injection cooling device for an air conditioner compressor

Abstract

The utility model provides a kind of air conditioner compressor liquid injection cooling device;The device includes: connecting low pressure side pipeline's pressure sensor and temperature sensor;High-pressure liquid storage tank connected with high pressure side pipeline, for storing liquid refrigerant when outdoor temperature rises;Electronic expansion valve input end connects high-pressure liquid storage tank outlet, and output end is connected with low pressure side pipeline through flash tank.Electronic expansion valve initial opening degree is based on outdoor temperature adjustment, and real-time opening degree is adjusted according to low pressure side pressure and temperature, and high pressure side liquid refrigerant is injected into low pressure side after throttling;Flash tank promotes liquid refrigerant flash evaporation, reduces its temperature.The utility model can ensure that high-temperature environment air conditioner operation can protect compressor compressor, and also ensure that it will not return liquid, and the indoor refrigeration capacity is not attenuated when opening liquid injection cooling.

Description

Technical Field

[0001] This utility model relates to a cooling device, and more particularly to an air conditioning compressor liquid injection cooling device, belonging to the field of air conditioning compressor liquid injection cooling technology. Background Technology

[0002] To prevent compressor overheating and burnout, current air conditioning technology incorporates liquid refrigerant injection cooling into the system. Liquid refrigerant injection is a method of bypassing liquid refrigerant to the low-pressure side (return gas side) of the system, controlled by a solenoid valve. This cooling limits exhaust temperature, preventing compressor overheating that could lead to lubricant deterioration and winding insulation aging.

[0003] Current air conditioning products mainly use exhaust temperature or exhaust superheat to control the opening and closing of solenoid valves. This structure and control method have the following problems:

[0004] First, the solenoid valve only has two states: open and closed. The refrigerant flow rate is not adjustable. For systems without a gas-liquid separator on the low-pressure side, this can easily cause a large amount of refrigerant to enter the compressor in a short period of time, resulting in compressor liquid compression, which affects the compressor's lifespan and system reliability.

[0005] Secondly, under high-temperature cooling conditions, the liquid injection cooling function will be used frequently. At this time, the solenoid valve will frequently open and close, and the refrigerant flow of the indoor unit will also change frequently. As a result, the cooling capacity of the indoor unit will fluctuate, and the perceived indoor temperature will fluctuate, affecting the user experience.

[0006] Third, the control based on exhaust temperature or exhaust superheat is often affected by the ambient temperature of the sensor and cannot accurately determine the bypass time. In addition, the position of the sensor determines the exhaust temperature, and the exhaust temperature sensor cannot intuitively reflect whether the liquid refrigerant drawn in on the low-pressure side will cause liquid compression in the compressor in a short time, and its control has a delay. Summary of the Invention

[0007] In view of this, the present invention provides an air conditioning compressor liquid spraying cooling device to solve or alleviate the technical problems existing in the prior art, and at least provides a beneficial option.

[0008] The technical solution of this utility model embodiment is implemented as follows: An air conditioning compressor liquid injection cooling device includes at least a liquid injection device, which includes a pressure sensor, a temperature sensor, a high-pressure liquid storage tank, an electronic expansion valve, and a flash evaporator. The pressure sensor and temperature sensor are connected to the low-pressure side pipeline and are used to detect the low-pressure side gas pipe pressure and temperature in real time, respectively. The high-pressure liquid storage tank is connected to the high-pressure side pipeline and is used to store liquid refrigerant when the air side temperature of the outdoor unit rises. The input end of the electronic expansion valve is connected to the outlet of the high-pressure liquid storage tank, and the output end is connected to the low-pressure side pipeline. The initial opening of the electronic expansion valve is adjusted based on the air side temperature of the outdoor unit, and the real-time opening of the electronic expansion valve is adjusted based on the low-pressure side gas pipe pressure and temperature, so that the liquid refrigerant in the high-pressure side pipeline is transferred to the low-pressure side pipeline. The flash evaporator is disposed between the electronic expansion valve and the low-pressure side pipeline to promote the flash evaporation of the liquid refrigerant, thereby reducing the temperature of the liquid refrigerant in the low-pressure side pipeline.

[0009] A further preferred embodiment: the inlet of the high-pressure liquid storage tank is connected to the high-pressure side pipeline between the compressor exhaust port and the outdoor unit heat exchanger.

[0010] A further preferred embodiment: the outlet of the flash tank is connected to the return gas line of the compressor via a three-way valve.

[0011] A further preferred embodiment: the liquid spraying device is disposed in the connecting pipeline between the outdoor unit and the indoor unit; the outdoor unit includes at least a compressor, an outdoor fan, an outdoor heat exchanger, an exhaust temperature sensor, a return air temperature sensor, and an ambient temperature sensor; the indoor unit includes at least a thermal expansion valve, an indoor fan, and an indoor heat exchanger.

[0012] A further preferred embodiment: the exhaust temperature sensor is located outside the compressor and connected to the low-pressure side pipeline; the exhaust temperature sensor is used to detect the exhaust temperature of the compressor; the return gas temperature sensor is located outside the compressor and connected to the return gas pipeline of the compressor; the return gas temperature sensor is used to detect the return gas temperature of the compressor; the ambient temperature sensor is located inside the outdoor unit; the ambient temperature sensor is used to detect the air-side temperature of the outdoor unit.

[0013] A further preferred embodiment: the inlet of the outdoor unit heat exchanger is connected to the exhaust temperature sensor, and the outlet is connected to the high-pressure side pipeline.

[0014] A further preferred embodiment: the input end of the thermostatic expansion valve is connected to the high-pressure side pipeline, and the output end is connected to the inlet of the indoor unit heat exchanger.

[0015] A further preferred embodiment: the outlet of the indoor unit heat exchanger is connected to the low-pressure side pipeline, and simultaneously connected to the temperature sensing bulb of the thermal expansion valve.

[0016] A further preferred embodiment: the outdoor unit fan and the indoor unit fan are respectively located inside the outdoor unit and the indoor unit.

[0017] The present invention has the following advantages due to the adoption of the above technical solution:

[0018] This invention can ensure that the air conditioner can protect the compressor in high-temperature environments while preventing liquid backflow, and the cooling capacity of the internal unit will not be reduced when liquid spray cooling is turned on.

[0019] The above overview is for illustrative purposes only and is not intended to be limiting in any way. In addition to the illustrative aspects, embodiments, and features described above, further aspects, embodiments, and features of the present invention will become readily apparent from the accompanying drawings and the following detailed description. Attached Figure Description

[0020] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0021] Figure 1 This is a structural diagram of the liquid injection cooling device for the air conditioning compressor described in this utility model.

[0022] Figure label:

[0023] 100-Outdoor unit of air conditioner, 101-Compressor, 102-Outdoor unit fan, 103-Outdoor unit heat exchanger, 104-Exhaust temperature sensor, 105-Return gas temperature sensor, 106-Ambient temperature sensor, 200-Indoor unit, 201-Thermal expansion valve, 202-Indoor unit fan, 203-Indoor unit heat exchanger, 300-Liquid spraying device, 301-Pressure sensor, 302-Temperature sensor, 303-High pressure liquid storage pipe, 304-Electronic expansion valve, 305-Flash tank. Detailed Implementation

[0024] In the following description, only certain exemplary embodiments are briefly described. As those skilled in the art will recognize, the described embodiments can be modified in various ways without departing from the spirit or scope of this invention. Therefore, the drawings and description are considered exemplary in nature and not restrictive.

[0025] The embodiments of this utility model will now be described in detail with reference to the accompanying drawings.

[0026] like Figure 1 As shown, this utility model embodiment provides a liquid injection cooling device for an air conditioning compressor 101, including at least a liquid injection device 300. The liquid injection device 300 includes a pressure sensor 301, a temperature sensor 302, a high-pressure liquid storage tank 303, an electronic expansion valve 304, and a flash tank 305. The pressure sensor 301 and temperature sensor 302 are connected to the low-pressure side pipeline and are used to detect the low-pressure side gas pipe pressure and temperature in real time, respectively. The high-pressure liquid storage tank 303 is connected to the high-pressure side pipeline and is used to store liquid refrigerant when the air-side temperature of the outdoor unit 100 rises. The electronic expansion valve 304... The input end of valve 304 is connected to the outlet of the high-pressure liquid receiver 303, and the output end is connected to the low-pressure side pipeline. The initial opening of the electronic expansion valve 304 is adjusted based on the air-side temperature of the outdoor unit 100, and the real-time opening of the electronic expansion valve 304 is adjusted based on the low-pressure side gas pipe pressure and low-pressure side gas pipe temperature, so that the liquid refrigerant in the high-pressure side pipeline is transferred to the low-pressure side pipeline. The flash tank 305 is disposed between the electronic expansion valve 304 and the low-pressure side pipeline to promote the flash evaporation of the liquid refrigerant, thereby reducing the temperature of the liquid refrigerant in the low-pressure side pipeline.

[0027] A further preferred embodiment: the inlet of the high-pressure liquid storage tank 303 is connected to the high-pressure side pipeline between the exhaust port of the compressor 101 and the outdoor unit heat exchanger 103.

[0028] A further preferred embodiment: the outlet of the flash tank 305 is connected to the return gas pipeline of the compressor 101 via a three-way valve.

[0029] Further preferred embodiment: the liquid spraying device 300 is disposed in the connecting pipeline between the outdoor unit 100 and the indoor unit 200; the outdoor unit 100 includes at least a compressor 101, an outdoor unit fan 102, an outdoor unit heat exchanger 103, an exhaust temperature sensor 104, a return gas temperature sensor 105, and an ambient temperature sensor 106; the indoor unit 200 includes at least a thermal expansion valve 201, an indoor unit fan 202, and an indoor unit heat exchanger 203.

[0030] Further preferably: the exhaust temperature sensor 104 is disposed on the outside of the compressor 101 and connected to the low-pressure side pipeline; the exhaust temperature sensor 104 is used to detect the exhaust temperature of the compressor 101; the return gas temperature sensor 105 is disposed on the outside of the compressor 101 and connected to the return gas pipeline of the compressor 101; the return gas temperature sensor 105 is used to detect the return gas temperature of the compressor 101; the ambient temperature sensor 106 is disposed inside the outdoor unit 100; the ambient temperature sensor 106 is used to detect the air-side temperature of the outdoor unit 100.

[0031] A further preferred embodiment: the inlet of the outdoor unit heat exchanger 103 is connected to the exhaust temperature sensor 104, and the outlet is connected to the high-pressure side pipeline.

[0032] A further preferred embodiment: the input end of the thermal expansion valve 201 is connected to the high-pressure side pipeline, and the output end is connected to the inlet of the indoor unit heat exchanger 203.

[0033] A further preferred embodiment: the outlet of the indoor heat exchanger 203 is connected to the low-pressure side pipeline, and simultaneously connected to the temperature sensing bulb of the thermal expansion valve 201.

[0034] A further preferred embodiment: the outdoor unit fan 102 and the indoor unit fan 202 are respectively disposed inside the outdoor unit 100 and the indoor unit 200.

[0035] When this utility model is in operation:

[0036] Without the liquid injection device 300: When the outdoor ambient temperature is high, and the indoor unit uses a thermal expansion valve 201, and the indoor ambient temperature is low, the condensation temperature of the refrigerant in the outdoor unit heat exchanger 103 also increases, and the corresponding refrigerant condensation pressure also increases, leading to an increase in the compressor 101 discharge pressure. Simultaneously, due to the lower indoor temperature, the indoor unit heat exchanger 203 cannot completely evaporate the refrigerant, thus reducing the superheat of the refrigerant in the indoor gas pipe. To maintain the superheat in the gas pipe, the thermal expansion valve 201 will control the orifice to narrow, resulting in a low pressure drop. The pressure difference between the intake and exhaust of compressor 101 increases, and the load on compressor 101 further increases. At the same time, due to heat exchange between the copper tubes and the ambient temperature, the superheat at the return gas point of compressor 101 is much higher than the superheat controlled by the thermal expansion valve 201. This causes the heat exchange effect of the refrigerant inside compressor 101 on the windings to decrease. Under the accumulation of multiple factors, the power of compressor 101 increases, the winding current increases, and the winding temperature of compressor 101 rises. This can easily cause the oil in compressor 101 to deteriorate and the insulation material of the windings to fail, leading to the burnout of compressor 101.

[0037] If the liquid injection device 300 is installed: the pressure sensor 301 detects the low-pressure side gas pipe pressure as P1 in real time, and the corresponding refrigerant saturation temperature is Te; the temperature sensor 302 detects the low-pressure side gas pipe temperature as T1 in real time. Then the return gas superheat is ΔTs=T1-Te, and the preset return gas superheat target value is Ta.

[0038] When the external temperature rises, the high-pressure liquid storage pipe of the liquid injection device 300 can store some liquid refrigerant to prevent a rapid increase in pressure. Simultaneously, when the thermal expansion valve 201 reduces its orifice due to the decrease in the indoor temperature, the opening of the electronic expansion valve 304 is adjusted using a PI control based on the error e = (ΔTs - Ta) between the return gas superheat and the preset target value of the return gas superheat. That is, when the orifice of the thermal expansion valve 201 shrinks, the opening of the electronic expansion valve 304 increases, allowing some of the liquid refrigerant on the high-pressure side to pass through the liquid injection device 300. Upon reaching the low-pressure side, the refrigerant absorbs heat during flash evaporation, thereby reducing the temperature of the refrigerant on the low-pressure side. This ensures that the return gas superheat ΔTs at the compressor 101 return gas port can be stabilized near the preset return gas superheat Ta, thus reducing the return gas temperature of the compressor 101 and enhancing the heat exchange efficiency between the internal windings and the refrigerant of the compressor 101. At the same time, it can also reduce the pressure on the high-pressure side, reduce the pressure difference between the high-pressure side and the low-pressure side of the compressor 101, reduce the load on the compressor 101, and thus reduce the heat generation of the compressor 101 windings; ultimately achieving the purpose of protecting the compressor 101.

[0039] In addition, the liquid refrigerant in the flash tank 305 has a lower temperature. After entering the main circuit, it can reduce the temperature of the main circuit refrigerant, allowing the refrigerant per unit mass flow rate flowing into the indoor unit 200 to absorb more heat, thereby compensating for the loss of cooling capacity caused by the reduced refrigerant flow rate into the indoor unit 200.

[0040] Specifically: Each time power is applied, the electronic expansion valve 304 sets an initial opening to prevent the compressor 101 from heating up too quickly during high-temperature startup, thus ensuring timely adjustment by the electronic expansion valve 304. The initial opening is related to the ambient temperature Th detected by the ambient temperature sensor 106, as shown in the table below:

[0041]

[0042] The number of expansion valve steps is calculated according to the formula below, so as to adjust the real-time opening of the electronic expansion valve 304 based on the number of opening steps and the size of the throttle orifice of the thermostatic expansion valve 201.

[0043] The opening step number STEP2 = STEP1 + ln(Tp) * e1 + (Ts - T1) * A * (e1 + e2) * ΔT; STEP1 represents the previous opening step number, Tp represents the exhaust temperature, e1 and e2 represent the previous setting error and the current setting error; Ts represents the return gas temperature, T1 represents the low-pressure side gas pipe temperature, A represents the temperature loss correction coefficient, and ΔT represents the integration time (the time interval between each adjustment); the setting error e = (ΔTs - Ta), ΔTs = T1 - Te; where Ta represents the preset return gas superheat target value, and Te represents the refrigerant saturation temperature corresponding to the low-pressure side gas pipe pressure.

[0044] The above description is merely a specific embodiment of this utility model, but the protection scope of this utility model is not limited thereto. Any person skilled in the art can easily conceive of various variations or substitutions within the technical scope disclosed in this utility model, and these should all be included within the protection scope of this utility model. Therefore, the protection scope of this utility model should be determined by the protection scope of the claims.

Claims

1. A liquid-spraying cooling device for an air conditioning compressor, characterized in that, It includes at least a liquid spraying device, which includes a pressure sensor, a temperature sensor, a high-pressure liquid storage tank, an electronic expansion valve, and a flash tank; The pressure sensor and temperature sensor are connected to the low-pressure side pipeline and are used to detect the low-pressure side tracheal pressure and low-pressure side tracheal temperature in real time, respectively. The high-pressure liquid storage tank is connected to the high-pressure side pipeline and is used to store liquid refrigerant when the air side temperature of the outdoor unit rises. The input end of the electronic expansion valve is connected to the outlet of the high-pressure liquid receiver, and the output end is connected to the low-pressure side pipeline; wherein, the initial opening degree of the electronic expansion valve is adjusted based on the air side temperature of the outdoor unit, and the real-time opening degree of the electronic expansion valve is adjusted based on the low-pressure side gas pipe pressure and low-pressure side gas pipe temperature, so that the liquid refrigerant in the high-pressure side pipeline is transferred to the low-pressure side pipeline. The flash tank is located between the electronic expansion valve and the low-pressure side pipeline to promote the flash evaporation of the liquid refrigerant, thereby reducing the temperature of the liquid refrigerant in the low-pressure side pipeline.

2. The air conditioning compressor liquid injection cooling device according to claim 1, characterized in that, The inlet of the high-pressure liquid storage tank is connected to the high-pressure side pipeline between the compressor exhaust port and the outdoor unit heat exchanger.

3. The air conditioning compressor liquid spray cooling device according to claim 1, characterized in that, The outlet of the flash tank is connected to the return gas line of the compressor via a three-way valve.

4. The air conditioning compressor liquid spray cooling device according to claim 1, characterized in that, The spraying device is installed in the connecting pipe between the outdoor unit and the indoor unit; The outdoor unit includes at least a compressor, an outdoor unit fan, an outdoor unit heat exchanger, an exhaust temperature sensor, a return air temperature sensor, and an ambient temperature sensor; The indoor unit includes at least a thermal expansion valve, an indoor unit fan, and an indoor unit heat exchanger.

5. The air conditioning compressor liquid spray cooling device according to claim 4, characterized in that, The exhaust temperature sensor is located on the outside of the compressor and connected to the low-pressure side pipeline; the exhaust temperature sensor is used to detect the exhaust temperature of the compressor. The return gas temperature sensor is located on the outside of the compressor and connected to the return gas pipeline of the compressor; the return gas temperature sensor is used to detect the return gas temperature of the compressor. The ambient temperature sensor is located inside the outdoor unit; the ambient temperature sensor is used to detect the air temperature on the outdoor unit.

6. The air conditioning compressor liquid spray cooling device according to claim 4, characterized in that, The inlet of the outdoor unit heat exchanger is connected to the exhaust temperature sensor, and the outlet is connected to the high-pressure side pipeline.

7. The air conditioning compressor liquid spray cooling device according to claim 4, characterized in that, The input end of the thermostatic expansion valve is connected to the high-pressure side pipeline, and the output end is connected to the inlet of the indoor unit heat exchanger.

8. The air conditioning compressor liquid spray cooling device according to claim 7, characterized in that, The outlet of the indoor unit heat exchanger is connected to the low-pressure side pipeline and simultaneously to the temperature sensing bulb of the thermal expansion valve.

9. The air conditioning compressor liquid spray cooling device according to claim 4, characterized in that, The outdoor unit fan and the indoor unit fan are respectively located inside the outdoor unit and the indoor unit.

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