Economizer performance test system and test method for heat pump air conditioning system

Abstract

The present application belongs to the technical field of heat pump air conditioner performance detection, and particularly relates to a heat pump air conditioner system economizer performance test system and test method. The test system comprises a first pressure transmitter arranged between a liquid accumulator and an economizer, a first mass flow meter arranged at the inlet of an electronic expansion valve, and a third pressure transmitter arranged between an evaporator and a gas-liquid separator of a heat pump air conditioner system to be tested. A first temperature transmitter is arranged along the main path pipeline connected to the economizer inlet direction, and a second temperature transmitter is arranged along the economizer outlet direction on the main path pipeline. A third temperature transmitter is arranged along the auxiliary path pipeline connected to the economizer inlet direction, and a fourth temperature transmitter, a second pressure transmitter and a second mass flow meter are sequentially arranged along the economizer outlet direction on the auxiliary path pipeline. The test system fills the gap of the current heat pump air conditioner system economizer performance test device and test method, and is conducive to promoting the development and application of heat pump air conditioner technology.

Description

Technical Field

[0001] This invention belongs to the field of heat pump air conditioning performance testing technology, specifically relating to a heat pump air conditioning system economizer performance testing system and testing method. Background Technology

[0002] Heat pump air conditioning is an energy-saving and environmentally friendly heating / cooling technology, and its future application prospects are very broad under the background of the "dual carbon" target.

[0003] Traditional scroll compressors in heat pump air conditioning systems experience problems such as increased suction volume, increased pressure ratio, and rapid rise in exhaust temperature when operating at low evaporation temperatures. This leads to decreased heating efficiency and seriously affects the safe operation of the compressor. Therefore, a scroll compressor with intermediate gas injection function, namely the gas injection enthalpy-increasing heat pump air conditioning system, has been developed. By additionally injecting medium-pressure, low-temperature refrigerant gas into the compressor's compression chamber, the exhaust volume is increased, the exhaust temperature and specific work are reduced, and the heating capacity is improved. Furthermore, the opening and closing of the gas injection channel can serve as an auxiliary means of capacity unloading regulation.

[0004] The core of the gas-fuel injection and enthalpy-increasing technology is the economizer. Specifically, the high-temperature, high-pressure refrigerant gas discharged from the compressor is condensed into a liquid after transferring heat to the heat transfer medium in the condenser. The high-pressure refrigerant liquid from the condenser is then divided into two streams after passing through the receiver: the main stream refrigerant liquid directly enters the economizer, while the auxiliary stream refrigerant liquid first passes through a solenoid valve, then through an expansion valve for throttling and pressure reduction, becoming a gas-liquid mixture before also entering the economizer. Heat exchange occurs between the two streams in the economizer; the auxiliary stream refrigerant liquid absorbs heat and becomes a gas, which is then drawn into the compressor's gas injection port. The main stream refrigerant releases heat, becoming a subcooled liquid, which is then throttled and pressure-reduced by the expansion valve before entering the evaporator. In the evaporator, the main stream refrigerant absorbs heat from the low-temperature environment and becomes a low-pressure gas, which is drawn into the compressor's suction port. The main and auxiliary stream refrigerants mix in the compressor's working chamber, are further compressed, and then discharged, completing the cycle.

[0005] The heat transfer and resistance characteristics of the economizer are crucial to the heating / cooling coefficient of performance, reliability, and cost of heat pump air conditioning systems. However, current industry focus is mostly on the development and optimization of evaporators and condensers, while performance testing equipment and methods for economizers in heat pump air conditioning systems remain lacking. Summary of the Invention

[0006] To address the aforementioned technical problems, this invention provides a heat pump air conditioning system economizer performance testing system.

[0007] The present invention adopts the following technical solution:

[0008] A heat pump air conditioning system economizer performance testing system is provided. In the heat pump air conditioning system under test, an economizer is installed between the liquid receiver and the electronic expansion valve. The economizer is connected to the liquid receiver of the heat pump air conditioning system under test through a main pipeline and an auxiliary pipeline, respectively. The refrigerant in the main pipeline enters the electronic expansion valve through the economizer, and the refrigerant in the auxiliary pipeline enters the compressor of the heat pump air conditioning system under test through the economizer.

[0009] The testing system includes a first pressure transmitter installed between the liquid receiver and the economizer, a first mass flow meter installed at the inlet of the electronic expansion valve, and a third pressure transmitter installed between the evaporator and the gas-liquid separator of the heat pump air conditioning system under test. A first temperature transmitter is installed on the main pipeline connecting to the economizer inlet, and a second temperature transmitter is installed on the main pipeline connecting to the economizer outlet. A third temperature transmitter and an electric regulating valve are installed on the auxiliary pipeline connecting to the economizer inlet, and a fourth temperature transmitter, a second pressure transmitter, and a second mass flow meter are sequentially installed on the auxiliary pipeline connecting to the economizer outlet.

[0010] Preferably, differential pressure transmitters are also installed on the main pipeline and the auxiliary pipeline of the economizer to measure the refrigerant pressure drop in the main pipeline and the auxiliary pipeline, respectively. The first differential pressure transmitter is connected to the main pipelines on both sides of the inlet and outlet of the economizer, and the second differential pressure transmitter is connected to the auxiliary pipelines on both sides of the inlet and outlet of the economizer.

[0011] Preferably, based on the refrigerant flow direction, the refrigerant inflow direction is defined as the front side and the refrigerant outflow direction as the rear side. Then, a ball-shaped shut-off valve is also provided on the front side of the first temperature transmitter, the rear side of the second temperature transmitter, the rear side of the third temperature transmitter, and the rear side of the fourth temperature transmitter.

[0012] Preferably, a first sight glass is also provided between the second pressure transmitter and the second mass flow meter for observing the phase state of the refrigerant at the outlet in the auxiliary pipeline.

[0013] The above-mentioned test method for the economizer performance testing system of a heat pump air conditioning system is based on the heat balance theory. By testing the pressure and temperature changes of the refrigerant in the main and auxiliary pipelines of the economizer, the enthalpy and heat transfer of the refrigerant in the auxiliary and main pipelines are calculated. Finally, the heat transfer, logarithmic mean temperature difference, and overall heat transfer coefficient of the economizer in the heat pump air conditioning system under test are calculated to obtain the comprehensive performance of the economizer of the heat pump air conditioning system under test.

[0014] Preferably, the specific steps for measurement and calculation are as follows:

[0015] S1. A test system is set up in the heat pump air conditioning system under test. In the heat pump air conditioning system under test, the high-pressure refrigerant in the receiver flows into the main pipeline and the auxiliary pipeline after passing through the first pressure transmitter. The main pipeline refrigerant enters the economizer after passing through the first temperature transmitter, and the auxiliary pipeline refrigerant enters the economizer after being throttled by the third temperature transmitter and the electric regulating valve on the auxiliary pipeline. The main pipeline refrigerant and the auxiliary pipeline refrigerant exchange heat in the economizer. After the heat exchange, the main pipeline refrigerant flows out of the economizer, passes through the second temperature transmitter and the first mass flow meter in sequence, and enters the evaporator in the heat pump air conditioning system under test. Then it passes through the third pressure transmitter and enters the gas-liquid separator. The auxiliary pipeline refrigerant flows out of the economizer, passes through the fourth temperature transmitter, the second pressure transmitter and the second mass flow meter in sequence, and directly enters the gas-liquid separator.

[0016] S2. The inlet pressure of the main pipeline of the economizer is obtained from the first pressure transmitter. The inlet temperature of the main pipeline of the economizer is obtained from the first temperature transmitter. The second temperature transmitter obtains the outlet temperature of the main pipeline of the economizer. The first differential pressure transmitter obtains the main line pressure drop. The first mass flow meter obtains the main refrigerant flow rate. ,but:

[0017] Main pipeline outlet pressure ,

[0018] Calculate the inlet enthalpy of the main pipeline based on the specific refrigerant properties and refer to the table. and the enthalpy value of the main pipeline outlet ,

[0019] Heat exchanger of the main pipeline of the economizer ,

[0020] The outlet temperature of the auxiliary pipeline of the economizer is obtained from the fourth temperature transmitter. The second pressure transmitter obtains the outlet pressure of the auxiliary pipeline of the economizer. The second differential pressure transmitter obtains the auxiliary circuit pressure drop. The second mass flow meter obtains the flow rate of the refrigerant in the auxiliary circuit. ,but:

[0021] Calculate the enthalpy value at the outlet of the auxiliary pipeline based on the specific refrigerant properties and refer to the table. The enthalpy value at the inlet of the auxiliary pipeline is obtained based on the third temperature transmitter and the first pressure transmitter. ,

[0022] Heat exchange of auxiliary pipelines of the economizer ;

[0023] S3. Calculate the heat exchanger of the economizer according to the following formulas. Thermal balance error Logarithmic mean temperature difference and overall heat transfer coefficient :

[0024]

[0025]

[0026]

[0027]

[0028] The heat exchange area of ​​the economizer.

[0029] Preferably, for the economizer performance test of the heat pump air conditioning system under specified operating conditions, the condensing pressure of the condenser in the heat pump air conditioning system is adjusted by controlling the flow rate of the condensing test water in the condenser, the evaporating pressure of the evaporator is adjusted by controlling the flow rate of the evaporating test water in the evaporator, the refrigerant flow rate in the main economizer pipeline is adjusted by changing the compressor frequency, and the refrigerant flow rate in the auxiliary economizer pipeline is adjusted by the opening of the electric regulating valve.

[0030] The beneficial effects of this invention are as follows:

[0031] The economizer performance testing system for heat pump air conditioning systems is built based on a conventional scroll compressor (non-gas-injection enthalpy-increasing compressor). The refrigerant at the economizer auxiliary circuit inlet becomes a two-phase gas-liquid mixture due to the throttling effect of the electric regulating valve. Since its dryness fraction cannot be measured, the inlet enthalpy cannot be obtained by measuring the inlet temperature and pressure. Considering that the throttling and pressure-reducing process is an isenthalpic process, and the refrigerant before the electric regulating valve is a single-phase liquid, this testing system uses a first pressure transmitter and a third temperature transmitter to obtain the refrigerant enthalpy before the valve, thus accurately determining the inlet enthalpy of the economizer auxiliary circuit refrigerant. By setting a first differential pressure transmitter and a first pressure transmitter, the main circuit outlet pressure can be obtained by subtracting the first differential pressure transmitter from the first pressure transmitter, and then, via the second temperature transmitter, the main circuit refrigerant outlet enthalpy can be accurately determined.

[0032] A first sight glass is installed at the outlet of the economizer auxiliary circuit to observe the phase state of the refrigerant at the outlet, accurately determine the stability test conditions of the economizer, and thus improve the accuracy of the test results.

[0033] Based on the testing system of this invention, a testing method for the thermal characteristics of the economizer in a heat pump air conditioning system is proposed for the first time, filling the gap in the current lack of testing devices and methods for the performance of the economizer in heat pump air conditioning systems, which is conducive to promoting the development and application of heat pump air conditioning technology. Attached Figure Description

[0034] Figure 1 A schematic diagram of a heat pump air conditioning system with an economizer in the prior art;

[0035] Figure 2 A schematic diagram of the heat pump air conditioning system structure for setting up the test system of this invention;

[0036] Figure 3 for Figure 2 Enlarged view of the test system;

[0037] Figure 4 This is a schematic diagram of the refrigerant flow control of the condenser and other components in the heat pump air conditioning system, which is used by this test system.

[0038] The meanings of the symbols in the diagram are as follows:

[0039] 10-Economy device; 11-Main pipeline; 12-Auxiliary pipeline; 13-Electric regulating valve

[0040] 20-First pressure transmitter; 21-First temperature transmitter; 22-Second temperature transmitter; 23-Third pressure transmitter; 24-First differential pressure transmitter; 25-Third temperature transmitter; 26-Second differential pressure transmitter; 27-Fourth temperature transmitter; 28-Second pressure transmitter; 29-First sight glass

[0041] 31-First mass flow meter; 32-Second mass flow meter

[0042] 41-High-pressure metal hose 42-Spherical shut-off valve

[0043] 50-Liquid reservoir; 51-Dryer filter; 52-Second sight glass; 53-Subcooler

[0044] 60 - Electronic expansion valve 70 - Evaporator

[0045] 80-Compressor 81-Gas-Liquid Separator 82-Oil Separator 83-Electric Heating Cable 84-Fourth Pressure Transmitter

[0046] 90-Condenser

[0047] A - First solenoid valve B - Second solenoid valve Detailed Implementation

[0048] The technical solution of the present invention will be described in more detail below with reference to the embodiments and accompanying drawings:

[0049] Example 1

[0050] like Figure 1The diagram shows the structure of an existing heat pump air conditioning system equipped with an economizer 10. It includes four main refrigeration components: a scroll compressor 80, a condenser 90, an electronic expansion valve 60, and an evaporator 70, as well as auxiliary equipment such as an oil separator 82, a liquid receiver 50, a dryer filter 51, a gas-liquid separator 81, and a second sight glass 52. The system's operation flow is as follows:

[0051] The compressor 80 discharges high-temperature, high-pressure refrigerant gas, which, after passing through the condenser 90 and transferring heat to the heat transfer medium, becomes liquid. The high-pressure refrigerant liquid from the condenser 90 passes through the receiver 50, and then through the dryer filter 51 and the second sight glass 52 before being divided into two paths. The main path refrigerant liquid directly enters the economizer 10, while the auxiliary path refrigerant liquid first passes through the solenoid valve, and then through the electronic expansion valve 60 for throttling and pressure reduction, becoming a gas-liquid mixture before also entering the economizer 10. The two paths exchange heat in the economizer 10. The auxiliary path refrigerant liquid absorbs heat and becomes gas, which is then drawn into the compressor 80's gas inlet. The main path refrigerant releases heat and becomes subcooled liquid, which, after being throttled and pressure-reduced by the electronic expansion valve 60, enters the evaporator 70. In the evaporator 70, the main path refrigerant absorbs heat from the low-temperature environment and becomes low-pressure gas, which is then drawn into the compressor 80's suction port after passing through the gas-liquid separator 81.

[0052] like Figure 2 As shown, depending on the heat pump air conditioning system under test, a subcooler 53 can be set in the heat pump air conditioning system under test to subcool the refrigerant liquid coming out of the condenser 90 to a set temperature in order to achieve the required subcooling degree. An electric heating tape 83 is set to adjust the temperature of the refrigerant entering the condenser 90. A fourth pressure transmitter 84 is set to measure the condensing pressure of the condenser 90, etc.

[0053] To test the performance of the economizer 10, the economizer performance testing system of the heat pump air conditioning system provided by the present invention is set in the heat pump air conditioning system to be tested. The main road and the auxiliary road of the economizer 10 are respectively called the main road pipe 11 and the auxiliary road pipe 12. The economizer 10 is connected to the liquid receiver 50 of the heat pump air conditioning system to be tested through the main road pipe 11 and the auxiliary road pipe 12 respectively.

[0054] The testing system includes a first pressure transmitter 20 located between the liquid receiver 50 and the economizer 10, a first mass flow meter 31 located at the inlet of the electronic expansion valve 60, and a third pressure transmitter 23 located between the evaporator 70 and the gas-liquid separator 81 of the heat pump air conditioning system under test. A first temperature transmitter 21 is installed on the main pipeline 11 connecting to the inlet of the economizer 10, and a second temperature transmitter 22 is installed on the main pipeline 11 connecting to the outlet of the economizer 10. A third temperature transmitter 25 and an electric regulating valve 13 are installed on the auxiliary pipeline 12 connecting to the inlet of the economizer 10, and a fourth temperature transmitter 27, a second pressure transmitter 28, and a second mass flow meter 32 are sequentially installed on the auxiliary pipeline 12 connecting to the outlet of the economizer 10.

[0055] Differential pressure transmitters are also installed on the main pipeline 11 and the auxiliary pipeline 12 of the economizer 10 to measure the refrigerant pressure drop in the main pipeline 11 and the auxiliary pipeline 12. The first differential pressure transmitter 24 is connected to the main pipeline 11 on both sides of the inlet and outlet of the economizer 10, and the second differential pressure transmitter 26 is connected to the auxiliary pipeline 12 on both sides of the inlet and outlet of the economizer 10.

[0056] Based on the refrigerant flow direction, the refrigerant inflow direction is defined as the front side and the refrigerant outflow direction as the rear side. Then, high-pressure metal hoses 41 and ball valves 42 are also provided on the front side of the first temperature transmitter 21, the rear side of the second temperature transmitter 22, the rear side of the third temperature transmitter 25, and the rear side of the fourth temperature transmitter 27. The high-pressure metal hoses 41 allow the main pipeline 11 and the auxiliary pipeline 12 to deform, which facilitates the replacement and control of various devices and equipment. The ball valves 42 are used to control the flow of refrigerant.

[0057] A first sight glass 29 is also installed between the second pressure transmitter 28 and the second mass flow meter 32 to observe the refrigerant phase at the outlet of the auxiliary pipeline 12. Typically, considering enthalpy changes, stable test conditions are only considered met when the refrigerant is completely vaporized or superheated. Figure 2 , Figure 3 As shown, in this test system, the second mass flow meter 32 is also interlocked with the electric regulating valve 13, which adjusts the flow rate of the auxiliary pipeline 12 of the economizer 10 under test by changing the opening of the electric regulating valve 13. Alternatively, the compressor 80 can be interlocked with the first mass flow meter 31, and the flow rate of the main pipeline 11 can be adjusted by controlling the frequency of the compressor 80.

[0058] The present invention provides a test method for the performance testing system of the economizer of a heat pump air conditioning system based on the heat balance theory. By testing the pressure and temperature changes of the refrigerant in the main pipeline 11 and the auxiliary pipeline 12 of the economizer 10 respectively, the enthalpy and heat transfer of the refrigerant in the auxiliary pipeline and the main pipeline are calculated. Finally, the heat transfer, logarithmic mean temperature difference and the overall heat transfer coefficient of the economizer 10 in the heat pump air conditioning system under test are calculated to obtain the comprehensive performance of the economizer of the heat pump air conditioning system under test.

[0059] The specific measurement and calculation steps are as follows:

[0060] S1. A test system is set up in the heat pump air conditioning system under test. In the heat pump air conditioning system under test, the high-temperature and high-pressure refrigerant liquid in the receiver 50 flows into the main pipeline 11 and the auxiliary pipeline 12 after passing through the first pressure transmitter 20. The main pipeline refrigerant enters the economizer 10 through the high-pressure metal hose 41 and the first temperature transmitter 21. The auxiliary pipeline refrigerant enters the economizer 10 after being throttled and depressurized by the third temperature transmitter 25 and the electric regulating valve 13 on the auxiliary pipeline 12, becoming a gas-liquid mixture. The main pipeline refrigerant liquid and the auxiliary pipeline refrigerant gas-liquid mixture undergo heat exchange in the economizer 10. After the heat exchange, the main pipeline refrigerant releases heat and becomes a subcooled liquid, flowing out of the economizer 10, and then sequentially passes through the first... After passing through the second temperature transmitter 22, high-pressure metal hose 41, ball shut-off valve 42, and first mass flow meter 31, the refrigerant enters the heat pump air conditioning system under test. The refrigerant is throttled and depressurized by the electronic expansion valve 60, becoming a gas-liquid two-phase system. It then passes through the evaporator 70, absorbing heat from the evaporation test water system and becoming a low-pressure gas, flowing through the third pressure transmitter 23. The auxiliary refrigerant absorbs heat and becomes a gas in the economizer 10, then flows out of the economizer 10 and sequentially passes through the fourth temperature transmitter 27, high-pressure metal hose 41, ball shut-off valve 42, second pressure transmitter 28, first sight glass 29, and second mass flow meter 32, mixing with the refrigerant gas in the main pipeline 11 before entering the gas-liquid separator 81.

[0061] During this process, the first differential pressure transmitter 24 and the second differential pressure transmitter 26 respectively measure the refrigerant pressure drop in the main pipeline 11. Refrigerant pressure drop in auxiliary pipeline 12 .

[0062] The main refrigerant and the auxiliary refrigerant are processed by the gas-liquid separator 81 and then enter the scroll compressor 80 for further compression before being discharged, thus forming a closed working cycle loop.

[0063] Before the formal test, the stability of the heat pump air conditioning system under test can be confirmed by observing the condensing pressure of the condenser 90 read by the fourth pressure transmitter 84 and the evaporating pressure of the evaporator 70 read by the third pressure transmitter 23. The pressure of the condenser 90 can be adjusted by controlling the flow rate of the condensing test water in the condenser 90, and the pressure of the evaporator 70 can be adjusted by controlling the flow rate of the evaporating test water in the evaporator 70.

[0064] S2. Based on the process in S1, the inlet pressure of the main pipeline 11 of the economizer is obtained from the first pressure transmitter 20. The inlet temperature of the main pipeline 11 is obtained from the first temperature transmitter 21. The second temperature transmitter 22 obtains the outlet temperature of the main pipeline 11. The first differential pressure transmitter 24 obtains the pressure drop of the main pipeline 11. The first mass flow meter 31 obtains the flow rate of the refrigerant in the main circuit. ,but:

[0065] Main pipeline 11 outlet pressure ,

[0066] Calculate the inlet enthalpy of the main pipeline 11 based on the specific refrigerant properties and refer to the table. and the enthalpy value of the outlet of the main pipeline 11 Specifically, it can be expressed as ,

[0067] Heat exchanger of main pipeline 11 of the economizer ,

[0068] The outlet temperature of the economizer auxiliary pipeline 12 is obtained from the fourth temperature transmitter 27. The second pressure transmitter 28 obtains the outlet pressure of the auxiliary pipeline 12 of the economizer. The second differential pressure transmitter 26 obtains the pressure drop of the auxiliary pipeline 12. The second mass flow meter 32 obtains the flow rate of the auxiliary refrigerant. .

[0069] Considering that the inlet of the auxiliary pipeline 12 of the economizer 10 is a gas-liquid two-phase system, and since its dryness cannot be measured, the inlet enthalpy cannot be obtained by measuring the inlet temperature and pressure. Therefore, it can be assumed that the enthalpy before and after the electric regulating valve 13 remains unchanged. Thus, the enthalpy at the inlet of the auxiliary pipeline 12 is... The pressure can be obtained from the first pressure transmitter 20 The temperature value obtained by the third temperature transmitter 25 The enthalpy value at the outlet of auxiliary pipeline 12 was calculated by referring to the corresponding data in the specific refrigerant property table. According to , And the calculation is obtained by referring to the corresponding data in the specific refrigerant property table.

[0070] It can be represented as , ,

[0071] Heat exchanger of auxiliary pipeline 12 of the economy unit .

[0072] S3. Calculate the heat exchange of economizer 10 according to the following formulas. Thermal balance error Logarithmic mean temperature difference and overall heat transfer coefficient :

[0073]

[0074]

[0075]

[0076]

[0077] The heat exchange area of ​​the economizer is 10.

[0078] In particular, the final performance data obtained by this testing system should be based on the premise that the thermal balance error is no more than 6% in order to ensure the accuracy of the test.

[0079] In addition, this testing system can also be used for performance testing of evaporator 70 and condenser 90. By adding a test pipe section instead of auxiliary pipe 12, the relevant testing methods are the same as the aforementioned economizer 10 testing principle, and will not be repeated here. Specifically, in one embodiment, such as... Figure 4 As shown, the subcooler 53 is also provided with a branch pipeline connected to the first mass flow meter 31. Furthermore, by setting the first electromagnetic switch valve A and the second electromagnetic switch valve B to control the refrigerant flow direction, the performance testing of the economizer 10, evaporator 70 and condenser 90 in the same heat pump air conditioning system under test can be realized.

[0080] The above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A performance testing system for an economizer in a heat pump air conditioning system, wherein the testing system is installed in the heat pump air conditioning system under test, and the heat pump air conditioning system under test has an economizer (10) installed between a liquid receiver (50) and an electronic expansion valve (60), and the economizer (10) is connected to the liquid receiver (50) of the heat pump air conditioning system under test through a main pipeline (11) and an auxiliary pipeline (12), respectively. The refrigerant in the main pipeline (11) enters the electronic expansion valve (60) through the economizer (10), and the refrigerant in the auxiliary pipeline (12) enters the compressor (80) of the heat pump air conditioning system under test through the economizer (10). The test system is characterized by comprising a first pressure transmitter (20) disposed between the liquid reservoir (50) and the economizer (10), a first mass flow meter (31) disposed at the inlet of the electronic expansion valve (60), and a third pressure transmitter (23) disposed between the evaporator (70) and the gas-liquid separator (81) of the heat pump air conditioning system under test; a first temperature transmitter (21) is disposed on the main pipeline (11) in the direction of connecting the inlet of the economizer (10), and a second temperature transmitter (22) is disposed on the main pipeline (11) in the direction of connecting the outlet of the economizer (10); a third temperature transmitter (25) and an electric regulating valve (13) are disposed on the auxiliary pipeline (12) in the direction of connecting the inlet of the economizer (10), and a fourth temperature transmitter (27), a second pressure transmitter (28), and a second mass flow meter (32) are disposed sequentially on the auxiliary pipeline (12) in the direction of connecting the inlet of the economizer (10); Differential pressure transmitters are also installed on the main pipeline (11) and auxiliary pipeline (12) of the economizer (10) to measure the refrigerant pressure drop in the main pipeline (11) and auxiliary pipeline (12). The first differential pressure transmitter (24) is connected to the main pipeline (11) on both sides of the inlet and outlet of the economizer (10), and the second differential pressure transmitter (26) is connected to the auxiliary pipeline (12) on both sides of the inlet and outlet of the economizer (10). Enthalpy at the inlet of the main pipeline (11) Enthalpy at the outlet of the main pipeline (11) Enthalpy value of inlet of auxiliary pipeline (12) Enthalpy value of the outlet of the auxiliary pipeline (12) The calculation method is as follows: The inlet pressure of the main pipeline (11) of the economizer is obtained from the first pressure transmitter (20). The inlet temperature of the main pipeline (11) is obtained from the first temperature transmitter (21). The second temperature transmitter (22) obtains the outlet temperature of the main pipeline (11). The first differential pressure transmitter (24) obtains the pressure drop of the main pipeline (11). ,but: Main pipeline (11) outlet pressure ; Calculate the enthalpy value at the outlet of the main pipeline (11) based on the specific refrigerant properties and refer to the table. and the inlet enthalpy of the main pipeline (11) Specifically, it can be expressed as , ; The outlet temperature of the economizer auxiliary pipeline (12) is obtained from the fourth temperature transmitter (27). The second pressure transmitter (28) obtains the outlet pressure of the auxiliary pipeline (12) of the economizer. The pressure obtained from the first pressure transmitter (20) The temperature value obtained by the third temperature transmitter (25) In addition to the specific refrigerant property data, the enthalpy value at the outlet of the auxiliary pipeline (12) It can be represented as Enthalpy value at the inlet of auxiliary pipeline (12) It can be represented as .

2. The economizer performance testing system for a heat pump air conditioning system as described in claim 1, characterized in that, Based on the refrigerant flow direction, the refrigerant inflow direction is defined as the front side and the refrigerant outflow direction is defined as the rear side. Then, a ball shut-off valve (42) is also provided on the front side of the first temperature transmitter (21), the rear side of the second temperature transmitter (22), the rear side of the third temperature transmitter (25), and the rear side of the fourth temperature transmitter (27).

3. The economizer performance testing system for a heat pump air conditioning system as described in claim 1, characterized in that, A first sight glass (29) is also provided between the second pressure transmitter (28) and the second mass flow meter (32) for observing the phase state of the outlet refrigerant in the auxiliary pipeline (12).

4. The test method for the economizer performance testing system of a heat pump air conditioning system as described in any one of claims 1-3, characterized in that, This method is based on the heat balance theory. By testing the pressure and temperature changes of the refrigerant in the main pipeline (11) and auxiliary pipeline (12) of the economizer (10) respectively, the enthalpy and heat exchange of the refrigerant in the auxiliary pipeline and the main pipeline are calculated. Finally, the heat exchange, logarithmic mean temperature difference and total heat transfer coefficient of the economizer (10) in the heat pump air conditioning system under test are calculated to obtain the comprehensive performance of the economizer of the heat pump air conditioning system under test.

5. The test method for the economizer performance test system of a heat pump air conditioning system as described in claim 4, characterized in that, The specific steps for measurement and calculation are as follows: S1. A test system is set up in the heat pump air conditioning system under test. In the heat pump air conditioning system under test, the high-pressure refrigerant in the receiver (50) flows into the main pipeline (11) and the auxiliary pipeline (12) respectively after passing through the first pressure transmitter (20). The main pipeline refrigerant enters the economizer (10) after passing through the first temperature transmitter (21), and the auxiliary pipeline refrigerant enters the economizer (10) after being throttled by the third temperature transmitter (25) and the electric regulating valve (13) on the auxiliary pipeline (12). The main pipeline refrigerant and the auxiliary pipeline refrigerant are subjected to cross-contamination in the economizer (10). Heat exchange; after heat exchange, the main refrigerant flows out of the economizer (10), passes through the second temperature transmitter (22) and the first mass flow meter (31) in sequence, and then enters the electronic expansion valve (60) of the heat pump air conditioning system under test, and then passes through the evaporator (70) and the third pressure transmitter (23) to enter the gas-liquid separator (81). The auxiliary refrigerant flows out of the economizer (10), passes through the fourth temperature transmitter (27), the second pressure transmitter (28) and the second mass flow meter (32) in sequence, and then enters the gas-liquid separator (81). S2. The inlet pressure of the main pipeline (11) of the economizer is obtained from the first pressure transmitter (20). The inlet temperature of the main pipeline (11) is obtained from the first temperature transmitter (21). The second temperature transmitter (22) obtains the outlet temperature of the main pipeline (11). The first differential pressure transmitter (24) obtains the pressure drop of the main pipeline (11). The first mass flow meter (31) obtains the flow rate of the refrigerant in the main circuit. ,but: Main pipeline (11) outlet pressure ; Calculate the inlet enthalpy of the main pipeline (11) based on the specific refrigerant properties and refer to the table. and the enthalpy value of the outlet of the main pipeline (11) , Heat exchange of the main pipeline (11) of the economizer ; The outlet temperature of the economizer auxiliary pipeline (12) is obtained from the fourth temperature transmitter (27). The second pressure transmitter (28) obtains the outlet pressure of the auxiliary pipeline (12) of the economizer. The second differential pressure transmitter (26) obtains the pressure drop of the auxiliary pipeline (12). The second mass flow meter (32) obtains the flow rate of the refrigerant in the auxiliary circuit. ,but: Calculate the outlet enthalpy of the auxiliary pipeline (12) based on the specific refrigerant properties and refer to the table. The inlet enthalpy of the auxiliary pipeline (12) is obtained from the third temperature transmitter (25) and the first pressure transmitter (20). , Heat exchange of auxiliary pipeline (12) of the economizer ; S3. Calculate the heat exchange of the economizer (10) according to the following formula. Thermal balance error Logarithmic mean temperature difference and overall heat transfer coefficient : The heat exchange area of ​​the economizer (10).

6. The test method for the economizer performance test system of a heat pump air conditioning system as described in claim 4, characterized in that, For the performance test of the economizer (10) of the heat pump air conditioning system under specified operating conditions, the condensing pressure of the condenser (90) in the heat pump air conditioning system is adjusted by controlling the flow rate of the condensing test water in the condenser (90), the evaporation pressure of the evaporator (70) is adjusted by controlling the flow rate of the evaporation test water in the evaporator (70), the refrigerant flow rate in the main pipeline (11) of the economizer (10) is adjusted by changing the frequency of the compressor (80), and the refrigerant flow rate in the auxiliary pipeline (12) of the economizer (10) is adjusted by the opening degree of the electric regulating valve (13).

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