Heat exchanger temperature alternating test system and test method

Abstract

The invention discloses a heat exchanger temperature alternating test system and test method. The heat exchanger temperature alternating test system comprises a compressor, a condenser, an expansion valve, an evaporator, a first bypass connecting pipe, a second bypass connecting pipe and a fourth bypass connecting pipe. A first three-way device is arranged on a pipeline between the compressor and the condenser, and a second three-way device is arranged on a pipeline between the compressor and the evaporator; the first bypass connecting pipe is connected to the first three-way device and is provided with a first constant-temperature heater and a first switch valve; the second bypass connecting pipe is connected to a pipeline between the first three-way device and the condenser, and a second switch valve is arranged on the second bypass connecting pipe; the first end of the third bypass connecting pipe is connected to the second three-way device, a second constant-temperature heater and a third switch valve are arranged on the third bypass connecting pipe, and the second end of the third bypass connecting pipe is connected to the first bypass connecting pipe; the first end of the fourth bypass connecting pipe is connected to the pipeline between the second three-way device and the compressor, a fourth switch valve is arranged on the fourth bypass connecting pipe, and the second end of the fourth bypass connecting pipe is connected to the second bypass connecting pipe.

Description

Technical Field

[0001] The invention relates to the technical field of temperature alternation testing of heat exchangers, and in particular to a temperature alternation testing system and a testing method for heat exchangers. Background Art

[0002] Currently, four-way valves are usually used in heat pump and refrigeration systems to switch the flow direction of the working fluid, so that the functions of the evaporator and condenser can be interchanged to meet the user's energy needs for cooling and heating at different times.

[0003] However, in actual use, since the alternating switching of cold and hot fluids in the heat exchanger will cause the working temperature to vary within a certain range, the heat exchanger will produce alternating thermal stress under certain temperature alternations, resulting in the risk of failure under the action of thermal stress. Therefore, it is necessary to conduct a temperature alternation test on the heat exchanger to verify the temperature alternation fatigue resistance of the heat exchanger. Summary of the invention

[0004] The present invention aims to overcome the defects in the above-mentioned prior art and provides a heat exchanger temperature alternation test system, which can facilitate the temperature alternation test by connecting the refrigerant inlet and outlet of the heat exchanger to be tested to the second ends of the first bypass pipe and the second bypass pipe of the system respectively, and can make the cold and hot fluids alternately switch into the heat exchanger to be tested by controlling the working states of a plurality of switch valves to test its temperature alternation fatigue resistance performance; and a method for performing a temperature alternation test on the heat exchanger to be tested by using the above-mentioned system.

[0005] To achieve the above object, the present invention provides a heat exchanger temperature alternation test system, which is used to test the fatigue resistance of the heat exchanger to be tested under temperature alternation conditions, including a compressor, a condenser, an expansion valve and an evaporator which are sequentially connected through a pipeline to form a loop; Wherein, a first three-way device with an adjustment function is provided on the pipeline between the high-temperature side of the refrigerant of the compressor and the condenser, and a second three-way device with an adjustment function is provided on the pipeline between the low-temperature side of the refrigerant of the compressor and the evaporator; The system also includes a first bypass pipe, a second bypass pipe, a third bypass pipe and a fourth bypass pipe; The first end of the first bypass pipe is connected to the third interface of the first three-way device and is provided with a first constant temperature heater and a first switch valve arranged in sequence, and the second end of the first bypass pipe is used to connect to the heat exchanger to be tested; The first end of the second bypass pipe is connected to the pipeline between the first three-way device and the condenser and is provided with a second switch valve, and the second end of the second bypass pipe is used to connect to the heat exchanger to be tested; The first end of the third bypass pipe is connected to the third interface of the second three-way device and is provided with a second constant temperature heater and a third switch valve arranged in sequence, and the second end of the third bypass pipe is connected to the pipe section between the first switch valve and the second end of the first bypass pipe; The first end of the fourth bypass pipe is connected to the pipeline between the second three-way device and the compressor and is provided with a fourth switch valve. The second end of the fourth bypass pipe is connected to the pipe section between the second switch valve and the second end of the second bypass pipe.

[0006] It is further configured as follows: it also includes a sealed box for installing the heat exchanger to be tested, and a refrigerant detector is arranged in the sealed box.

[0007] It is further configured as follows: a water storage tank, a circulation pump, and an air-cooled radiator are connected between the water side of the evaporator and the water side of the condenser.

[0008] It is further configured as follows: a fifth switch valve is provided on the pipe section between the first bypass pipe and the third bypass pipe and the second end, and a sixth switch valve is provided on the pipe section between the second bypass pipe and the fourth bypass pipe and the second end.

[0009] It is further configured as follows: a first regulating pipe is connected between the pipe section between the first constant temperature heater and the first switch valve corresponding to the first bypass pipe, and between the pipe section between the first end of the second bypass pipe and the second switch valve, and a first regulating pipe is provided with a first regulating valve.

[0010] It is further configured as follows: a second regulating pipe is connected between the second end of the third bypass pipe and the second end of the fourth bypass pipe, and a second regulating valve is arranged on the second regulating pipe.

[0011] It is further configured as follows: the first three-way device is a three-way regulating valve or a combination of a three-way regulating valve and a regulating valve or a combination of a three-way regulating valve and a regulating valve.

[0012] It is further configured as follows: the second three-way device is a three-way regulating valve or a combination of a three-way regulating valve and a regulating valve or a combination of a three-way regulating valve and a regulating valve.

[0013] The present invention also provides a heat exchanger temperature alternation test method, which is implemented based on the above-mentioned heat exchanger temperature alternation test system and includes the following steps: Step 1: Connect the system to the heat exchanger to be tested and perform initialization testing; Step 2: Start the circulating water system of the system and adjust the water flow to a given state; Step 3: Turn on the heat pump system of the system to adjust the compressor suction temperature, exhaust temperature and refrigerant flow rate to a given state; Step 4: Turn on the first constant temperature heater and the second constant temperature heater, close the first, second, fifth and sixth switch valves, and adjust the cold and hot fluids to be connected to the heat exchanger to be tested to a specified state.

[0014] Step 5: After the system movement is stable, the first, second, fifth and sixth switch valves are opened, the third and fourth switch valves are closed, and the hot fluid is connected to the heat exchanger to be tested for a specified time; Step 6: close the first and second switch valves, open the third and fourth switch valves, and connect the cold fluid to the heat exchanger to be tested for a specified time; When steps 5 and 6 are completed, a test cycle is completed; Continuously cycle step 5 and step 6 until the specified number of cycles is completed and the test is terminated; Alternatively, the heat exchanger to be tested fails and the test is terminated.

[0015] Compared with the prior art, the test system of the present invention has a simple and reasonable structure. By connecting the refrigerant inlet and outlet of the heat exchanger to be tested to the second ends of the first bypass pipe and the second bypass pipe of the system respectively, a temperature alternation test can be conveniently performed. By controlling the working states of a number of switch valves, hot and cold fluids can be alternately switched into the heat exchanger to be tested to test its temperature alternation fatigue resistance performance. At the same time, the test method implemented based on the above system also has the above advantages. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a structural schematic diagram of a heat exchanger temperature alternation test system of the present invention; Figure 2 It is a schematic diagram of the connection structure of the system corresponding to the high-temperature fluid; Figure 3 It is a schematic diagram of the connection structure of the system corresponding to the cryogenic fluid; Figure 4 This is a schematic diagram of the structure of a three-way device with an adjustment function. Figure 1 ; Figure 5 This is a schematic diagram of the structure of a three-way device with an adjustment function. Figure 2 .

[0017] The following reference numerals are marked on the drawings in conjunction with the drawings: 11. Compressor; 12. Condenser; 13. Expansion valve; 14. Evaporator; 15. First three-way device; 16. Second three-way device; 21. First bypass pipe; 22. Second bypass pipe; 23. First constant temperature heater; 24. First switch valve; 25. Second switch valve; 31. Third bypass pipe; 32. Fourth bypass pipe; 33. Second constant temperature heater; 34. Third switch valve; 35. Fourth switch valve; 41. Water tank; 42. Circulation pump; 43. Air-cooled radiator; 51. Heat exchanger to be tested; 52. Sealed box; 53. Refrigerant detector; 61. Fifth switch valve; 62. Sixth switch valve; 63. First regulating valve; 64. Second regulating valve. DETAILED DESCRIPTION

[0018] A specific implementation of the present invention is described in detail below in conjunction with the accompanying drawings, but it should be understood that the protection scope of the present invention is not limited by the specific implementation.

[0019] The present invention provides a heat exchanger temperature alternation test system as follows Figures 1 to 3 As shown, it is used to test the fatigue resistance of the heat exchanger 51 to be tested under temperature alternating conditions, including a compressor 11, a condenser 12, an expansion valve 13, an evaporator 14, a first bypass pipe 21, a second bypass pipe 22, a third bypass pipe 31 and a fourth bypass pipe 32, wherein the compressor 11, the condenser 12, the expansion valve 13 and the evaporator 14 are sequentially connected through pipelines to form a refrigerant circuit, the first ends of the first bypass pipe 21 and the second bypass pipe 22 are both connected to the pipeline between the high temperature side of the compressor 11 and the condenser 12, and the second ends of the first bypass pipe 21 and the second bypass pipe 22 are used to be respectively connected to the refrigerant inlet and outlet of the heat exchanger 51 to be tested to form a first bypass path; the first ends of the third bypass pipe 31 and the fourth bypass pipe 32 are both connected to the pipeline between the low temperature side of the compressor 11 and the evaporator 14, and the second ends of the third bypass pipe 31 and the fourth bypass pipe 32 are used to be respectively connected to the refrigerant inlet and outlet of the heat exchanger 51 to be tested to form a second bypass path.

[0020] In this embodiment, if Figures 1 to 3As shown, a first three-way device 15 with a regulating function is provided on the pipeline between the high-temperature side of the compressor 11 and the condenser 12, a first end of the first bypass pipe 21 is connected to the third interface of the first three-way device 15 and a first constant temperature heater 23 and a first switch valve 24 arranged in sequence are provided thereon, a first end of the second bypass pipe 22 is connected to the pipeline between the first three-way device 15 and the condenser 12 and a second switch valve 25 is provided thereon, so that the first bypass path and the refrigerant circuit can be connected or disconnected by controlling the synchronous opening or closing of the first switch valve 24 and the second switch valve 25; the first three-way device 15 is used to regulate the distribution of the refrigerant flow in the refrigerant circuit and the first bypass path, and the first three-way device 15 is preferably a three-way regulating valve ( Figure 1 ) or a combination of a three-way valve and a regulating valve ( Figure 4 ) or a combination of a three-way regulating valve and a regulating valve ( Figure 5 ).

[0021] In this embodiment, if Figures 1 to 3 As shown, a second three-way device 16 with an adjusting function is arranged on the pipeline between the low-temperature side of the compressor 11 and the evaporator 14, a first end of the third bypass pipe 31 is connected to the third interface of the second three-way device 16 and a second constant temperature heater 33 and a third switch valve 34 arranged in sequence are arranged thereon, a first end of the fourth bypass pipe 32 is connected to the pipeline between the second three-way device 16 and the compressor 11 and a fourth switch valve 35 is arranged thereon, so that the second bypass path and the refrigerant circuit can be connected or disconnected by controlling the synchronous opening or closing of the third switch valve 34 and the fourth switch valve 35; the second three-way device 16 is used to regulate the distribution of the refrigerant flow on the second bypass path and the refrigerant circuit, and the second three-way device 16 is preferably a three-way regulating valve or a combination of a three-way and a regulating valve or a combination of a three-way regulating valve and a regulating valve.

[0022] In the above scheme, preferably, the second end of the third bypass pipe 31 is connected to the pipe section between the first switch valve 24 and the second end of the first bypass pipe 21, and the second end of the fourth bypass pipe 32 is connected to the pipe section between the second switch valve 25 and the second end of the second bypass pipe 22. In this way, the heat exchanger 51 to be tested only needs to be connected to the second ends of the first and second bypass pipes 22 to enable the heat exchanger 51 to be tested to be connected to the first and second bypass paths.

[0023] like Figure 2As shown, by closing the third and fourth switch valves 35 and opening the first, second, fifth and sixth switch valves 62, the high-temperature fluid in the test system can flow into the heat exchanger 51 to be tested. The specific flow path of the high-temperature fluid is: high-temperature side of the compressor 11 → first three-way device 15 → first constant temperature heater 23 → first switch valve 24 → fifth switch valve 61 → heat exchanger 51 to be tested → sixth switch valve 62 → second switch valve 25 → condenser 12 → expansion valve 13 → evaporator 14 → second three-way device 16 → low-temperature side of the compressor 11.

[0024] like Figure 3 As shown, by closing the first and second switch valves 25 and opening the third, fourth, fifth and sixth switch valves 62, the low-temperature fluid in the test system can flow into the heat exchanger 51 to be tested. The specific flow path of the low-temperature fluid is: high-temperature side of the compressor 11 → first three-way device 15 → condenser 12 → expansion valve 13 → evaporator 14 → second three-way device 16 → second constant temperature heater 33 → third switch valve 34 → fifth switch valve 61 → heat exchanger 51 to be tested → sixth switch valve 62 → fourth switch valve 35 → low-temperature side of the compressor 11.

[0025] Such a system Figure 2 and Figure 3 The alternating switching between the high temperature fluid and the low temperature fluid can make the high temperature fluid and the low temperature fluid flow alternately into the heat exchanger 51 to be tested to perform a temperature alternation test.

[0026] In this embodiment, the system also includes a sealed box 52 with a sealed chamber. The heat exchanger 51 to be tested is installed in the sealed box 52 and a high-precision refrigerant detector 53 for detecting the refrigerant is provided therein. If the refrigerant detector 53 detects refrigerant in the sealed box 52, it indicates that the heat exchanger 51 to be tested has failed and leaked, and an alarm can be sounded for timely processing.

[0027] In this embodiment, a water tank 41, a circulating pump 42, and an air-cooled radiator 43 are connected between the water side of the evaporator 14 and the water side of the condenser 12. The condenser 12, the air-cooled radiator 43, the evaporator 14, the water tank 41, and the circulating pump 42 are connected to form a neutralization circuit. The neutralization circuit can neutralize the heat absorbed by the evaporator 14 and the heat released by the condenser 12, thereby greatly reducing the heat dissipation loss and saving the test energy consumption of the system.

[0028] In this embodiment, preferably, a fifth switch valve 61 is provided on the end section of the first bypass pipe 21 corresponding to the portion close to the second end, that is, the fifth switch valve 61 is provided on the pipe section between the first bypass pipe 21 and the portion where it is connected to the third bypass pipe 31, and the second end thereof; a sixth switch valve 62 is provided on the end section of the second bypass pipe 22 corresponding to the portion close to the second end, that is, the sixth switch valve 62 is provided on the pipe section between the second bypass pipe 22 and the portion where it is connected to the fourth bypass pipe 32, and the second end thereof; thus, by closing the fifth and sixth switch valves 62, the disassembly and assembly of the heat exchanger 51 to be tested can be facilitated.

[0029] In this embodiment, a first regulating pipe is connected between the pipe section between the first constant temperature heater 23 and the first switch valve 24 corresponding to the first bypass pipe 21, and a first regulating pipe is connected between the pipe section between the first end of the second bypass pipe 22 and the second switch valve 25, and a first regulating valve 63 is arranged on the first regulating pipe; a second regulating pipe is connected between the second end of the third bypass pipe 31 and the second end of the fourth bypass pipe 32, and a second regulating valve 64 is arranged on the second regulating pipe; in this way, the distribution of the refrigerant flow can be further adjusted by the first regulating valve 63 and the second regulating valve 64.

[0030] The present invention also provides a heat exchanger temperature alternation test method, which is implemented based on the above-mentioned heat exchanger temperature alternation test system and includes the following steps: Step 1: Connect the system to the heat exchanger to be tested and perform initialization testing; Step 2: Start the system's circulating water system and adjust the water flow to a given state; Step 3: Turn on the heat pump system of the system to adjust the compressor suction temperature, exhaust temperature and refrigerant flow rate to a given state; Step 4: Turn on the first constant temperature heater and the second constant temperature heater, close the first, second, fifth and sixth switch valves, and adjust the cold and hot fluids to be connected to the heat exchanger to be tested to a specified state; Step 5: After the system movement is stable, the first, second, fifth and sixth switch valves are opened, the third and fourth switch valves are closed, and the hot fluid is connected to the heat exchanger to be tested for a specified time; Step 6: close the first and second switch valves, open the third and fourth switch valves, and connect the cold fluid to the heat exchanger to be tested for a specified time; When steps 5 and 6 are completed, a test cycle is completed; Continuously cycle step 5 and step 6 until the specified number of cycles is completed and the test is terminated, indicating that the heat exchanger to be tested meets the temperature alternating fatigue resistance performance; Alternatively, the heat exchanger to be tested fails, the refrigerant detector alarms, and the test is terminated.

[0031] In this way, the temperature alternating fatigue resistance performance of the plate heat exchanger to be tested can be conveniently detected by the above test method.

[0032] Compared with the prior art, the test system of the present invention has a simple and reasonable structure. By connecting the refrigerant inlet and outlet of the heat exchanger to be tested to the second ends of the first bypass pipe and the second bypass pipe of the system respectively, a temperature alternation test can be conveniently performed. By controlling the working states of a number of switch valves, hot and cold fluids can be alternately switched into the heat exchanger to be tested to test its temperature alternation fatigue resistance performance. At the same time, the test method implemented based on the above system also has the above advantages.

[0033] The above disclosure is only an embodiment of the present invention, but the present invention is not limited thereto, and any changes that can be conceived by those skilled in the art should fall within the protection scope of the present invention.

Claims

1. A heat exchanger temperature alternation test system, characterized in that: It is used to test the fatigue resistance of the heat exchanger under temperature alternation conditions, including a compressor, a condenser, an expansion valve and an evaporator connected in sequence through a pipeline to form a loop; Wherein, a first three-way device with an adjustment function is provided on the pipeline between the high-temperature side of the compressor and the condenser, and a second three-way device with an adjustment function is provided on the pipeline between the low-temperature side of the compressor and the evaporator; The system also includes a first bypass pipe, a second bypass pipe, a third bypass pipe and a fourth bypass pipe; The first end of the first bypass pipe is connected to the third interface of the first three-way device and is provided with a first constant temperature heater and a first switch valve arranged in sequence, and the second end of the first bypass pipe is used to connect to the heat exchanger to be tested; The first end of the second bypass pipe is connected to the pipeline between the first three-way device and the condenser and is provided with a second switch valve, and the second end of the second bypass pipe is used to connect to the heat exchanger to be tested; The first end of the third bypass pipe is connected to the third interface of the second three-way device and is provided with a second constant temperature heater and a third switch valve arranged in sequence, and the second end of the third bypass pipe is connected to the pipe section between the first switch valve and the second end of the first bypass pipe; The first end of the fourth bypass pipe is connected to the pipeline between the second three-way device and the compressor and is provided with a fourth switch valve. The second end of the fourth bypass pipe is connected to the pipe section between the second switch valve and the second end of the second bypass pipe.

2. A heat exchanger temperature alternation test system according to claim 1, characterized in that: It also includes a sealed box for installing the heat exchanger to be tested, and a refrigerant detector is arranged in the sealed box.

3. A heat exchanger temperature alternation test system according to claim 1, characterized in that: A water storage tank, a circulation pump and an air-cooled radiator are connected between the water side of the evaporator and the water side of the condenser.

4. A heat exchanger temperature alternation test system according to claim 1, characterized in that: A fifth switch valve is provided on the pipe section between the first bypass pipe and the third bypass pipe and the second end, and a sixth switch valve is provided on the pipe section between the second bypass pipe and the fourth bypass pipe and the second end.

5. A heat exchanger temperature alternation test system according to claim 1, characterized in that: A first regulating pipe is connected between the pipe section between the first thermostatic heater and the first switch valve corresponding to the first bypass pipe and the pipe section between the first end of the second bypass pipe and the second switch valve, and a first regulating valve is arranged on the first regulating pipe.

6. A heat exchanger temperature alternation test system according to claim 1, characterized in that: A second regulating pipe is connected between the second end of the third bypass pipe and the second end of the fourth bypass pipe, and a second regulating valve is arranged on the second regulating pipe.

7. A heat exchanger temperature alternation test system according to claim 1, characterized in that: The first three-way device is a three-way regulating valve or a combination of a three-way regulating valve and a regulating valve or a combination of a three-way regulating valve and a regulating valve.

8. A heat exchanger temperature alternation test system according to claim 1, characterized in that: The second three-way device is a three-way regulating valve or a combination of a three-way regulating valve and a regulating valve or a combination of a three-way regulating valve and a regulating valve.

9. A heat exchanger temperature alternation test method, characterized in that: The method is implemented based on the heat exchanger temperature alternation test system according to any one of claims 1 to 8, and comprises the following steps: Step 1: Connect the system to the heat exchanger to be tested and perform initialization testing; Step 2: Start the circulating water system of the system and adjust the water flow to a given state; Step 3: Turn on the heat pump system of the system to adjust the compressor suction temperature, exhaust temperature and refrigerant flow rate to a given state; Step 4: Turn on the first constant temperature heater and the second constant temperature heater, close the first, second, fifth and sixth switch valves, and adjust the cold and hot fluids to be connected to the heat exchanger to be tested to a specified state; Step 5: After the system movement is stable, the first, second, fifth and sixth switch valves are opened, the third and fourth switch valves are closed, and the hot fluid is connected to the heat exchanger to be tested for a specified time; Step 6: close the first and second switch valves, open the third and fourth switch valves, and connect the cold fluid to the heat exchanger to be tested for a specified time; When steps 5 and 6 are completed, a test cycle is completed; Continuously cycle step 5 and step 6 until the specified number of cycles is completed and the test is terminated; Alternatively, the heat exchanger to be tested fails and the test is terminated.

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