Small charge r290 refrigerant automobile air conditioner single heat exchanger test system

Abstract

The application discloses a small-charge R290 refrigerant automobile air conditioner single heat exchanger test system, which comprises the following: a superheater is arranged at the outlet of a compressor, and the outlet of the superheater is connected with a condenser; a first temperature and pressure sensor is arranged at the inlet of the measured condenser; a second temperature and pressure sensor is arranged at the outlet of the measured condenser; the condenser is a test piece or a matching piece; a flow meter is arranged at the outlet of the condenser, and the outlet of the flow meter is connected with a subcooler; the subcooler is arranged at the inlet of an expansion valve, and is used for controlling the temperature at the inlet of the expansion valve during evaporator testing; the expansion valve is arranged at the outlet of the subcooler; a third temperature and pressure sensor is arranged at the inlet of the expansion valve; an evaporator is arranged at the outlet of the expansion valve, and the evaporator is a test piece or a matching piece; a fourth temperature and pressure sensor is arranged at the outlet of the evaporator; a liquid storage tank is arranged on a connecting pipeline between the outlet of the flow meter and the inlet of the compressor; a recovery electromagnetic valve is arranged at the inlet of the liquid storage tank; and a filling electromagnetic valve is arranged at the outlet of the liquid storage tank.

Description

Technical Field

[0001] This invention relates to the field of environmental control, and in particular to a testing system for a single heat exchanger in an automotive air conditioning unit with a small charge of R290 refrigerant. Background Technology

[0002] In the automotive air conditioning field, with the global acceleration of the low-carbon transition, R290 (propane), as a natural hydrocarbon refrigerant, has great potential for application in closed air conditioning systems of electric passenger cars and commercial vehicles due to its excellent environmental performance, high energy efficiency, low cost, and compatibility with existing lubricants. However, because R290 is flammable and explosive, its research and application in automotive air conditioning systems still face many challenges. Among these challenges, the larger the amount of R290 refrigerant added to the automotive air conditioning heat exchanger testing system, the higher the risk. Therefore, the design and testing methods of small-volume systems will become a new direction for technological research and development.

[0003] Currently, there is a structural reference for testing systems of small-volume R290 refrigerants for automotive air conditioning unit heat exchangers. Figure 1 As shown, since the evaporator and condenser of the test unit cannot work simultaneously, an auxiliary condenser and calorimeter are also required to achieve the heat exchanger performance test. At the same time, the calorimeter requires auxiliary electric heating, pressure vessels and other expensive components to work. Therefore, the existing method has relatively high initial investment and operating costs. In addition, the complex system structure greatly increases the system piping and volume, which leads to a significant increase in the amount of flammable and explosive R290 charged, which drastically increases the test safety risk. Therefore, it is particularly important to design a test system and experimental method for small-volume R290 refrigerant automotive air conditioning unit heat exchanger. Summary of the Invention

[0004] The summary of this invention introduces a series of simplified concepts, all of which are simplifications of existing technologies in the field, and will be further explained in detail in the detailed description section. This summary is not intended to limit the key features and essential technical features of the claimed technical solution, nor is it intended to determine the scope of protection of the claimed technical solution.

[0005] The technical problem to be solved by the present invention is to provide a small-volume R290 refrigerant automotive air conditioning unit heat exchanger testing system for thermal performance testing of small-volume flammable and explosive refrigerants, which can reduce costs while minimizing the amount of flammable and explosive refrigerant added to the testing system, thereby reducing the safety risks of testing heat exchangers in flammable and explosive air conditioning systems.

[0006] To solve the above-mentioned technical problems, the present invention provides a testing system for small-capacity R290 refrigerant automotive air conditioning unit heat exchangers, comprising:

[0007] The compressor is used to power the circulation of flammable and explosive refrigerant in the test system;

[0008] The superheater is located at the compressor outlet, and its outlet is connected to the condenser being tested. It is used to control the inlet temperature of the condenser being tested during condenser testing.

[0009] The first temperature sensor and the first pressure sensor are located at the inlet of the condenser being tested;

[0010] The second temperature sensor and the second pressure sensor are located at the outlet of the condenser being tested.

[0011] Condenser, which is used as a fitting component in the testing of test pieces or evaporators;

[0012] A flow meter is installed at the outlet of the condenser, and its outlet is connected to the subcooler. It is used to measure the mass flow rate of the refrigerant during experiments.

[0013] The subcooler is located at the inlet of the expansion valve and is used to control the inlet temperature of the expansion valve during evaporator testing.

[0014] An expansion valve, located at the subcooler outlet, is used to control the evaporator outlet temperature.

[0015] The third temperature sensor and the third pressure sensor are located at the inlet of the expansion valve;

[0016] Evaporator, located at the outlet of the expansion valve, is a fitting component used in testing test pieces or condensers;

[0017] The fourth temperature sensor and the fourth pressure sensor are located at the evaporator outlet;

[0018] A liquid receiver is installed on the connecting pipe between the flow meter outlet and the compressor inlet to regulate the refrigerant circulation volume of the test system.

[0019] A recovery solenoid valve, located at the inlet of the liquid storage tank, is used to recover refrigerant in the test system;

[0020] A solenoid valve is installed at the outlet of the liquid storage tank and is used to add refrigerant to the test system.

[0021] Preferably, in the further improved small-capacity R290 refrigerant automotive air conditioning unit heat exchanger testing system, the compressor is an explosion-proof compressor.

[0022] Preferably, the improved test system for the small-capacity R290 refrigerant automotive air conditioning unit heat exchanger features an evaporator that is either air-cooled or water-cooled, and a condenser that is either a finned heat exchanger or a shell-and-tube heat exchanger.

[0023] Preferably, the small-capacity R290 refrigerant automotive air conditioning unit heat exchanger testing system is further improved, wherein the condenser refrigerant adopts direct heating or indirect system heating, and the electric heating used has explosion-proof characteristics.

[0024] Preferably, the test system for the small-charge R290 refrigerant automotive air conditioning unit heat exchanger is further improved such that, when performing the condenser heat exchange experiment, the enthalpy values ​​of the condenser inlet and outlet are H1 = f(T1, P1) and H2 = f(T2, P2), respectively.

[0025] When performing the evaporator heat exchange experiment, the enthalpy values ​​of the evaporator inlet and outlet are H3=f(T3,P3) and H4=f(T4,P4), respectively.

[0026] T1 to T4 represent the temperatures collected by the first to fourth temperature sensors, respectively.

[0027] P1 to P4 represent the pressures collected by the first to fourth pressure sensors, respectively.

[0028] Preferably, the small-charge R290 refrigerant automotive air conditioning unit heat exchanger test system is further improved by obtaining the refrigerant mass flow rate MF participating in the circulation during the condenser test based on the flow meter measurement; and calculating the heat exchange on the refrigerant side of the condenser: Qcond=MF*(H2-H1) / 3.6.

[0029] Preferably, the small-charge R290 refrigerant automotive air conditioning unit heat exchanger test system is further improved by obtaining the refrigerant mass flow rate MF participating in the circulation during the condenser test based on the flow meter measurement; and calculating the heat exchange on the refrigerant side of the evaporator: Qevap=MF*(H4-H3) / 3.6.

[0030] Compared to existing technologies that use flammable and explosive refrigerant replacement systems (approximately 5-8 kg of refrigerant), the present invention employs a whole-system flammable and explosive refrigerant single-unit testing method (approximately 1-1.5 kg of refrigerant), which greatly simplifies the system configuration (at least simplifying the calorimeter, system condenser, and related piping). The simplified piping reduces the required refrigerant charge, thus lowering the amount of refrigerant added to the system. This not only reduces hardware costs, the complexity of the testing system, and refrigerant loss, but also significantly improves the safety of testing flammable and explosive refrigerants. It allows for safer testing of the heat exchange performance of the evaporator and condenser in automotive flammable and explosive refrigerant air conditioning systems while reducing costs. Attached Figure Description

[0031] The accompanying drawings are intended to illustrate the general characteristics of the methods, structures, and / or materials used in specific exemplary embodiments of the invention, supplementing the description in the specification. However, the drawings are schematic diagrams not drawn to scale and may not accurately reflect the precise structural or performance characteristics of any of the given embodiments. The drawings should not be construed as limiting or restricting the range of numerical values ​​or properties covered by exemplary embodiments of the invention. The invention will now be described in further detail with reference to the accompanying drawings and specific embodiments:

[0032] Figure 1 This is a schematic diagram of an existing R290 refrigerant automotive air conditioning unit heat exchanger testing system;

[0033] Figure 2 This is a schematic diagram of the test system for a small-volume R290 refrigerant automotive air conditioning unit heat exchanger provided by the present invention; Detailed Implementation

[0034] The following specific embodiments illustrate the implementation of the present invention. Those skilled in the art can fully understand other advantages and technical effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through different specific embodiments, and various details in this specification can also be applied based on different viewpoints, with various modifications or changes made without departing from the overall design concept of the invention. It should be noted that, in the absence of conflict, the following embodiments and features in the embodiments can be combined with each other. The following exemplary embodiments of the present invention can be implemented in many different forms and should not be construed as being limited to the specific embodiments set forth herein. It should be understood that these embodiments are provided to make the disclosure of the present invention thorough and complete, and to fully convey the technical solutions of these exemplary embodiments to those skilled in the art. It should be understood that when an element is referred to as "connected" or "combined" to another element, the element can be directly connected or combined to the other element, or there may be intermediate elements. The difference is that when an element is referred to as "directly connected" or "directly combined" to another element, there are no intermediate elements. Throughout the drawings, the same reference numerals always denote the same elements.

[0035] First embodiment;

[0036] refer to Figure 2 As shown, this invention provides a testing system for a single heat exchanger in an automotive air conditioning unit with a small R290 refrigerant charge, comprising:

[0037] The compressor is used to power the circulation of flammable and explosive refrigerant in the test system;

[0038] The superheater is located at the compressor outlet, and its outlet is connected to the condenser being tested. It is used to control the inlet temperature of the condenser being tested during condenser testing.

[0039] The first temperature sensor and the first pressure sensor are located at the inlet of the condenser being tested;

[0040] The second temperature sensor and the second pressure sensor are located at the outlet of the condenser being tested.

[0041] Condenser, which is used as a fitting component in the testing of test pieces or evaporators;

[0042] A flow meter is installed at the outlet of the condenser, and its outlet is connected to the subcooler. It is used to measure the mass flow rate of the refrigerant during experiments.

[0043] The subcooler is located at the inlet of the expansion valve and is used to control the inlet temperature of the expansion valve during evaporator testing.

[0044] An expansion valve, located at the subcooler outlet, is used to control the evaporator outlet temperature.

[0045] The third temperature sensor and the third pressure sensor are located at the inlet of the expansion valve;

[0046] Evaporator, located at the outlet of the expansion valve, is a fitting component used in testing test pieces or condensers;

[0047] The fourth temperature sensor and the fourth pressure sensor are located at the evaporator outlet;

[0048] A liquid receiver is installed on the connecting pipe between the flow meter outlet and the compressor inlet to regulate the refrigerant circulation volume of the test system.

[0049] A recovery solenoid valve, located at the inlet of the liquid receiver, is used to recover refrigerant from the test system. During recovery, the condenser outlet temperature decreases and increases.

[0050] The solenoid valve, located at the outlet of the liquid receiver, is used to add refrigerant to the test system. During the adding process, the condenser outlet temperature decreases.

[0051] The compressor is an explosion-proof compressor, the evaporator is air-cooled or water-cooled, the condenser is a finned heat exchanger or a shell-and-tube heat exchanger, the refrigerant in the condenser is either directly heated or indirectly heated, and the electric heating used for heating has explosion-proof features.

[0052] The test system structure for a single heat exchanger of automotive air conditioning unit with small R290 refrigerant charge provided in the first embodiment;

[0053] When performing the condenser heat exchange experiment, the enthalpy values ​​of the condenser inlet and outlet are H1 = f(T1, P1) and H2 = f(T2, P2), respectively.

[0054] When performing the evaporator heat exchange experiment, the enthalpy values ​​of the evaporator inlet and outlet are H3=f(T3,P3) and H4=f(T4,P4), respectively.

[0055] T1 to T4 represent the temperatures collected by the first to fourth temperature sensors, respectively.

[0056] P1 to P4 represent the pressures collected by the first to fourth pressure sensors, respectively.

[0057] Therefore, based on the liquid flow meter method and enthalpy difference method for heat exchanger testing, the heat transfer on the refrigerant side of the condenser can be obtained as follows: Qcond=MF*(H2-H1) / 3.6;

[0058] Therefore, based on the liquid flow meter method and enthalpy difference method for heat exchanger testing, the heat transfer on the refrigerant side of the evaporator can be obtained as follows: Qevap=MF*(H4-H3) / 3.6;

[0059] Unless otherwise defined, all terms used herein (including technical and scientific terms) shall have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. It will also be understood that, unless expressly defined herein, terms such as those defined in a general dictionary shall be interpreted as having the meaning consistent with their meaning in the relevant field context, and not as having an idealized or overly formal meaning.

[0060] The present invention has been described in detail above through specific embodiments and examples, but these are not intended to limit the invention. Many modifications and improvements can be made by those skilled in the art without departing from the principles of the invention, and these should also be considered within the scope of protection of the present invention.

Claims

1. A testing system for a single heat exchanger in an automotive air conditioning unit with a small charge of R290 refrigerant, characterized in that, include: The compressor is used to power the circulation of flammable and explosive refrigerant in the test system; The superheater is located at the compressor outlet, and its outlet is connected to the condenser being tested. It is used to control the inlet temperature of the condenser being tested during condenser testing. The first temperature sensor and the first pressure sensor are located at the inlet of the condenser being tested; The second temperature sensor and the second pressure sensor are located at the outlet of the condenser being tested. Condenser, which is used as a fitting component in the testing of test pieces or evaporators; A flow meter is installed at the outlet of the condenser, and its outlet is connected to the subcooler. It is used to measure the mass flow rate of the refrigerant during experiments. The subcooler is located at the inlet of the expansion valve and is used to control the inlet temperature of the expansion valve during evaporator testing. An expansion valve, located at the subcooler outlet, is used to control the evaporator outlet temperature. The third temperature sensor and the third pressure sensor are located at the inlet of the expansion valve; Evaporator, located at the outlet of the expansion valve, is a fitting component used in testing test pieces or condensers; The fourth temperature sensor and the fourth pressure sensor are located at the evaporator outlet; A liquid receiver is installed on the connecting pipe between the flow meter outlet and the compressor inlet to regulate the refrigerant circulation volume of the test system. A recovery solenoid valve, located at the inlet of the liquid storage tank, is used to recover refrigerant in the test system; A solenoid valve is installed at the outlet of the liquid storage tank and is used to add refrigerant to the test system.

2. The testing system for a single heat exchanger of a small-capacity R290 refrigerant automotive air conditioning unit as described in claim 1, characterized in that: The compressor is an explosion-proof compressor.

3. The testing system for small-volume R290 refrigerant automotive air conditioning unit heat exchanger as described in claim 1, characterized in that: The evaporator is either air-cooled or water-cooled, and the condenser is either a finned heat exchanger or a shell-and-tube heat exchanger.

4. The testing system for a single heat exchanger of a small-capacity R290 refrigerant automotive air conditioning unit as described in claim 1, characterized in that: The condenser refrigerant is either directly heated or indirectly heated, and the electric heating used for heating has explosion-proof features.

5. The testing system for a single heat exchanger of a small-capacity R290 refrigerant automotive air conditioning unit as described in claim 1, characterized in that: When performing the condenser heat exchange experiment, the enthalpy values ​​of the condenser inlet and outlet are H1 = f(T1, P1) and H2 = f(T2, P2), respectively. When performing the evaporator heat exchange experiment, the enthalpy values ​​of the evaporator inlet and outlet are H3=f(T3,P3) and H4=f(T4,P4), respectively. T1 to T4 represent the temperatures collected by the first to fourth temperature sensors, respectively. P1 to P4 represent the pressures collected by the first to fourth pressure sensors, respectively.

6. The testing system for a single heat exchanger of a small-capacity R290 refrigerant automotive air conditioning unit as described in claim 5, characterized in that: The refrigerant mass flow rate MF participating in the circulation during the condenser test is obtained from the flow meter measurement; the heat exchange on the refrigerant side of the condenser is calculated as: Qcond=MF*(H2-H1) / 3.

6.

7. The test system for small-volume R290 refrigerant automotive air conditioning unit heat exchanger as described in claim 5, characterized in that: The refrigerant mass flow rate MF participating in the circulation during the condenser test is obtained from the flow meter measurement; the heat exchange on the refrigerant side of the evaporator is calculated as: Qevap=MF*(H4-H3) / 3.6.

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