System volume-adjustable device and method for evaluating starting characteristic of refrigeration compressor

Abstract

The present invention relates to the technical field of compressor performance testing and testing equipment manufacturing. Disclosed are a system volume-adjustable device and method for evaluating the starting characteristic of a refrigeration compressor. The evaluation device comprises a sample under test, a test refrigeration system and a test control system. By means of controlling a high-pressure-end volume regulator, a low-pressure-end volume regulator and a condensing coil, the evaluation device precisely adjusts a refrigeration system volume, so as to match the test requirements of different compressors for the refrigeration system volume, and provide a volume-adjustable substitute refrigeration system for starting characteristic testing. The present invention synchronously collects transient characteristic parameters such as intake and exhaust pressure, inter-phase voltage, phase line current and housing vibration acceleration at the instant of a compressor start, and non-transient characteristic parameters such as the in-housing temperature of a variable-frequency driver, the temperature of a power module and the temperature of a rectifier bridge, so as to accurately measure and evaluate the starting characteristics of the refrigeration compressor in specific environments.

Description

A device and method for evaluating the start-up characteristics of a refrigeration compressor with adjustable system volume. Technical Field

[0001] This invention relates to the field of performance testing and inspection equipment manufacturing technology for refrigeration appliance compressors, specifically to a device and method for evaluating the start-up characteristics of refrigeration appliance compressors with adjustable system volume. Background Technology

[0002] Variable frequency compressors use brushless DC motors, and the compressor startup is controlled by a variable frequency drive. Currently, the level of automation in evaluating the startup characteristics of variable frequency compressors in the refrigeration compressor industry is still relatively low. It is difficult to accurately measure parameters such as phase-to-phase voltage, phase line current, vibration acceleration, and suction and discharge pressure at the moment of startup of the variable frequency compressor, thus making it impossible to accurately evaluate the startup characteristics of the variable frequency compressor.

[0003] In summary, the development of an evaluation device for the starting characteristics of variable frequency compressors in refrigeration appliances, especially the system volume adjustable technology for matching refrigeration appliances with different cooling capacities, has become a key issue that the refrigeration compressor manufacturing industry urgently needs to address.

[0004] Summary of the Invention

[0005] In view of the above-mentioned problems in the prior art, the purpose of the present invention is to provide a compressor start-up characteristic evaluation device and method with adjustable system volume, so as to realize the accurate measurement and evaluation of the start-up characteristic parameters of variable frequency refrigeration compressor under specific conditions.

[0006] This invention provides the following technical solution:

[0007] An evaluation device for the start-up characteristics of a refrigeration compressor with adjustable system volume is disclosed. The device includes a test sample (inverter compressor and driver), a test refrigeration system, and a test control system. The evaluation device adopts a dual-environment structure, providing two assembly stations for the test sample to offer different test temperature environments: a room temperature test environment and a high temperature test environment. The device can perform alternating room temperature and high temperature tests on the test sample at both assembly stations. The test temperature in the room temperature test environment is the ambient temperature of the test sample, while the test temperature range in the high temperature test environment is from the ambient temperature to 90°C (inclusive).

[0008] Furthermore, the tested sample includes the tested variable frequency compressor and driver. When the tested variable frequency compressor and driver are tested under normal temperature conditions, the tested sample is placed in a normal temperature environment chamber. When the tested variable frequency compressor and driver are tested under high temperature conditions, the tested sample is placed in a high temperature environment chamber.

[0009] Furthermore, the test refrigeration system includes a main circulation subsystem, a low-pressure end volume regulation subsystem, a high-pressure end volume regulation subsystem, a liquid charging subsystem, a discharge subsystem, a recovery subsystem, and a vacuum subsystem. The main circulation subsystem consists of a normal temperature valve, a high-temperature valve, a high-temperature ambient chamber heating element, an exhaust pressure sensor, a large condensing coil valve, a large condensing coil, a small condensing coil valve, a small condensing coil, a condensing chamber heating element, a balance valve, a shut-off valve, an expansion valve, an evaporator coil, an evaporator fan, and a suction pressure sensor. The low-pressure end volume regulation subsystem consists of a low-pressure end volume valve and a low-pressure end volume regulator. The high-pressure end volume regulation subsystem consists of a high-pressure end volume valve and a high-pressure end volume regulator. The liquid charging subsystem consists of a check valve, a suction liquid charging valve, an exhaust liquid charging valve, a liquid charging needle valve, and a liquid charging manual valve. The discharge subsystem consists of a check valve, a suction discharge valve, an exhaust discharge valve, a discharge needle valve, and a discharge manual valve. The recovery subsystem consists of a return valve, a recovery valve, a recovery storage tank, a recovery condenser, an oil separator, a recovery pump, and a recovery valve. The vacuum subsystem consists of an evacuation valve and a vacuum pump.

[0010] Furthermore, the test and control system uses an industrial control computer as its control core to realize the system control, data acquisition, and data processing of the entire evaluation device. The industrial control computer uses a monitor, keyboard, mouse, and printer as input / output devices to enable human-machine interaction and report printing within the evaluation device. The industrial control computer uses a digital I / O control module to realize the digital input / output control of the evaluation device. The digital inputs include gas source underpressure alarm signal, ambient over-temperature alarm signal, and condenser over-temperature alarm signal. The digital outputs (digital outputs refer to 0 / 1 switch signals) include high-temperature ambient chamber heater (switch signal), condenser chamber heater (switch signal), high-temperature ambient chamber cooling unit (switch signal), frequency converter power supply frequency range (high / low range signal), frequency converter power supply voltage range (high / low range signal), ambient temperature valve (switch signal), high-temperature valve (switch signal), balance valve (switch signal), shut-off valve (switch signal), recovery pump (switch signal), recovery valve (switch signal), vacuum pump (switch signal), vacuum valve (switch signal), suction liquid filling valve (switch signal), suction discharge valve (switch signal), discharge liquid filling valve (switch signal), discharge discharge valve (switch signal), low-pressure side volume valve (switch signal), high-pressure side volume valve (switch signal), low-pressure side volume adjustment driver (PWM pulse signal), high-pressure side volume adjustment driver (PWM pulse signal), large condenser coil valve (switch signal), small condenser coil valve (switch signal), and the tested variable frequency compressor (start / stop signal). The industrial control computer uses a high-speed AI sampling module to synchronously acquire key start-up characteristic parameters (transient characteristic parameters) of the tested variable frequency compressor, including sensor data such as suction pressure, discharge pressure, UV voltage, VW voltage, WU voltage, bus current, U-phase current, V-phase current, W-phase current, vertical vibration acceleration, and horizontal vibration acceleration. The industrial control computer also uses a temperature sampling module to acquire temperature data (high-temperature chamber temperature, condenser temperature, and non-transient characteristic parameters) of key components of the tested variable frequency compressor and its driver, including sensor data such as high-temperature chamber temperature, condenser temperature, compressor casing temperature, variable frequency driver casing temperature, power module temperature, rectifier bridge temperature, filter capacitor temperature, and radiator temperature. The industrial control computer uses an AO output module to automatically adjust the expansion valve and variable frequency power supply voltage of the refrigeration system. The industrial control computer uses an electrical parameter table to acquire electrical parameters such as input voltage, current, power, and frequency of the variable frequency compressor and its driver. Finally, the industrial control computer uses a signal generator to automatically adjust the speed of the variable frequency compressor.

[0011] Furthermore, the aforementioned system volume adjustable refrigeration compressor start-up characteristic evaluation device measures the start-up characteristic parameters of the sample, including suction and discharge pressure, operating voltage, operating current, vibration acceleration, and temperatures of key components. The start-up characteristic parameters of the variable frequency compressor can be divided into transient and non-transient characteristic parameters. Transient characteristic parameters include the discharge pressure, suction pressure, vertical vibration acceleration, horizontal vibration acceleration, and the input UV voltage, VW voltage, WU voltage, bus current, U-phase current, V-phase current, and W-phase current of the variable frequency compressor. A high-speed synchronous acquisition mode is used, with a sampling rate range of 1KS / s to 50KS / s, selected according to the required accuracy of the characteristic parameter measurement. The default sampling rate of the evaluation device is 10KS / s. Non-transient characteristic parameters include the compressor casing temperature, the variable frequency drive casing temperature, the power module temperature, the rectifier bridge temperature, the filter capacitor temperature, and the radiator temperature, which are acquired through a temperature sampling module.

[0012] Furthermore, in the aforementioned refrigeration compressor start-up characteristic evaluation device with adjustable system volume, the refrigeration system volume can be adjusted via a high-pressure end volume regulator, a low-pressure end volume regulator, and a condensing coil. High-pressure end volume adjustment is achieved through the piston position within its internal cavity. Low-pressure end volume adjustment is also achieved through the piston position within its internal cavity. The system liquid storage volume is adjusted via the condensing coil; the opening and closing of the large and small condensing coil valves allows for three combinations of liquid storage volumes.

[0013] A method for evaluating the start-up characteristics of a refrigeration compressor with adjustable system volume, the method comprising the following steps:

[0014] Step 1: Installation of the variable frequency compressor and driver under test: Determine the environmental temperature requirements of the test sample. If the test is conducted at room temperature, place the variable frequency compressor and driver under test in a room temperature environment chamber. If the test is conducted at high temperature, place the variable frequency compressor and driver under test in a high temperature environment chamber. Then, complete the connection of the intake and exhaust pipes and electrical circuits of the variable frequency compressor under test.

[0015] Step 2: Setting Test Parameters and Test Modes: Before initiating the performance evaluation, the test conditions must be set. These parameters include exhaust pressure, intake pressure, ambient temperature, operating voltage, speed / frequency, and number of cycles. There are two test modes: single-condition testing and multi-condition testing. Single-condition testing involves testing the sample under a single set set of parameters to assess its startup characteristics, complete the performance evaluation, and generate a report. Multi-condition testing involves testing the sample under multiple set parameters. After one test condition is completed, the parameters are changed according to the set values, and the system automatically performs tests at new test conditions until all test conditions are completed, finally completing the performance evaluation and generating a report.

[0016] Step 3. Test the volume adjustment of the refrigeration system: Determine the system volume for evaluating the starting characteristics of the tested variable-frequency compressor according to the matching situation between the tested sample and the test refrigeration system. Then, complete the volume adjustment of the entire test refrigeration system of the compressor starting characteristic evaluation device through the piston positions of the high-pressure end volume regulator and the low-pressure end volume regulator, as well as the opening and closing of the large condenser coil valve and the small condenser coil valve;

[0017] Step 4. Test the adjustment of the test conditions of the refrigeration system: Automatically adjust parameters such as the suction pressure, discharge pressure, ambient temperature, working voltage, and rotational speed frequency of the compressor starting characteristic evaluation device. When all the condition parameters reach the set requirements, start the tested variable-frequency compressor through the variable-frequency drive;

[0018] Step 5. Collect the starting characteristic parameters: After the tested variable-frequency compressor starts, the high-speed AI sampling module of the test control system starts to synchronously collect various characteristic parameters, including the suction and discharge pressures, phase-to-phase voltage, phase current, vibration acceleration, etc. At the same time, the temperature sampling module collects the shell temperature of the variable-frequency compressor, the internal temperature of the shell of the driver, the power module temperature, etc. The test control system also collects other data, including various electrical parameters input by the variable-frequency drive. After the tested variable-frequency compressor runs for a certain period of time, the test control system shuts down the compressor, and then determines whether the number of cycles reaches the set requirements;

[0019] Step 6. Evaluate the starting characteristics: Process the collected test data, evaluate the starting characteristics of the tested variable-frequency compressor and the driver, generate a starting characteristic evaluation report, and finally save the test data and report to the database.

[0020] Furthermore, for the method for evaluating the starting characteristics of a refrigeration compressor with adjustable system volume, the evaluation of the starting transient characteristic parameters is the determination of parameters such as the suction and discharge pressures, vibration acceleration, phase-to-phase voltage, and phase current. During the starting process of the tested variable-frequency compressor, if the minimum value p s of the suction pressure is less than or equal to the design threshold p′ s min [[ID=...]] ≤ p′ s , it is determined that the suction pressure is qualified; otherwise, it is determined as unqualified. If the maximum value p d of the discharge pressure is greater than or equal to the design threshold p′ d max ≥ p′ d , it is determined that the discharge pressure is qualified; otherwise, it is determined as unqualified. If the maximum value a i of the vibration acceleration is less than or equal to the design threshold a′ imax ≤ a′ i , it is determined that the vibration acceleration is qualified; otherwise, it is determined as unqualified. If the maximum value U j of the phase-to-phase voltage is less than or equal to the design threshold U′ jmax ≤ U′j , the phase-to-phase voltage is determined to be qualified; otherwise, it is determined to be unqualified. If the phase current I k the maximum value of I kmax is less than or equal to the designed threshold I′ k , the phase current is determined to be qualified; otherwise, it is determined to be unqualified. The specific determination conditions are shown in formula (1):

[0021] In the formula, a1 is the vertical vibration acceleration, a′1 is the designed threshold of the vertical vibration acceleration; a2 is the horizontal vibration acceleration, a′2 is the designed threshold of the horizontal vibration acceleration; U1 is the UV voltage, U′1 is the designed threshold of the UV voltage; U2 is the VW voltage, U′2 is the designed threshold of the VW voltage; U3 is the WU voltage, U′3 is the designed threshold of the WU voltage; I1 is the bus current, I′1 is the designed threshold of the bus current; I2 is the U-phase current, I′2 is the designed threshold of the U-phase current; I3 is the V-phase current, I′3 is the designed threshold of the V-phase current; I4 is the W-phase current, I′4 is the designed threshold of the W-phase current.

[0022] Furthermore, for the method for evaluating the starting characteristics of a refrigeration compressor with adjustable system volume, the evaluation of the starting non-transient characteristic parameters is the determination of parameters such as the housing temperature, the temperature inside the housing of the variable frequency driver, the power module temperature, the rectifier bridge temperature, the filter capacitor temperature, and the radiator temperature. During the starting process of the tested variable frequency compressor, if the maximum value T imax is less than or equal to the designed threshold T′ i , it is determined to be qualified; otherwise, it is determined to be unqualified. The specific determination conditions are shown in formula (2): T imax ≤T′ i i = 1, 2, 3, 4, 5, 6 (2);

[0023] In the formula, T1 is the housing temperature, T′1 is the designed threshold of the housing temperature; T2 is the temperature inside the housing of the variable frequency driver, T′2 is the designed threshold of the temperature inside the housing of the variable frequency driver; T3 is the power module temperature, T′3 is the designed threshold of the power module temperature; T4 is the rectifier bridge temperature, T′4 is the designed threshold of the rectifier bridge temperature; T5 is the filter capacitor temperature, T′5 is the designed threshold of the filter capacitor temperature; T6 is the radiator temperature, T′6 is the designed threshold of the radiator temperature.

[0024] Furthermore, the aforementioned method for evaluating the start-up characteristics of a refrigeration compressor with adjustable system volume evaluates the start-up characteristics of the tested sample by assessing the real-time speed during the start-up phase. First, the phase current of the tested variable frequency compressor is transformed using a time-frequency conversion to obtain the time-frequency diagram of the start-up phase current, thereby obtaining the real-time speed of the tested variable frequency compressor. The start-up characteristics are then used to determine whether they meet the design requirements based on the real-time speed curve during the start-up phase. The real-time speed of the tested variable frequency compressor is calculated as shown in formula (3):

[0025] In the formula, n is the speed of the variable frequency compressor under test, and f is the current frequency of the variable frequency compressor under test.

[0026] By employing the above-described technology, the beneficial effects of the present invention compared to the prior art are as follows:

[0027] 1) The evaluation device of the present invention adopts a dual-environment structure. The test sample is tested in different environmental chambers under normal temperature and high temperature conditions. It can perform round-trip testing of the test sample at two assembly stations under normal temperature and high temperature conditions, which not only considers the economy of the evaluation device, but also improves the efficiency of testing.

[0028] 2) This invention achieves precise adjustment of the refrigeration system volume through the high-pressure end volume regulator, the low-pressure end volume regulator, and the condenser coil, matching the testing requirements of different compressors for the refrigeration system volume, providing a substitute refrigeration system with adjustable volume for start-up characteristic testing; it meets the testing requirements of the tested samples for different refrigeration system volumes, is suitable for the evaluation requirements of start-up characteristics of various displacement variable frequency compressors, and significantly improves the testing range of the device;

[0029] 3) In the testing of the device of the present invention, the test control system realizes intelligent control of the test medium filling volume, and automatically adds and discharges liquid according to the set suction and discharge pressure conditions, without the need for test personnel to operate, which greatly improves the intelligence level of the device.

[0030] 4) The combined function of the evaluation device, refrigeration system and test control system of this invention can realize fully automatic testing of the start-up characteristics of variable frequency compressors under different environments, single or multiple operating conditions, and complete the start-up characteristic judgment and test report generation, and save the test data in the database.

[0031] 5) This invention is applicable not only to the research on the matching of compressors and refrigeration systems, but also to the quality inspection in compressor manufacturing. Attached Figure Description

[0032] Figure 1 is a schematic diagram of the external structure of the device of the present invention;

[0033] Figure 2 is a side cross-sectional view of the device of the present invention;

[0034] Figure 3 is a structural diagram of the refrigeration system of the device of the present invention;

[0035] Figure 4 is a hardware architecture diagram of the test control system of the device of the present invention;

[0036] Figure 5 is a flowchart of the evaluation method of the present invention;

[0037] Figure 6 is a diagram of intake and exhaust pressures during the start-up phase of the evaluation method of the present invention.

[0038] Figure 7 is a vibration acceleration diagram during the start-up phase of the evaluation method of the present invention;

[0039] Figure 8 is a UV voltage diagram during the startup phase of the evaluation method of the present invention;

[0040] Figure 9 is a U-phase current diagram during the startup phase of the evaluation method of the present invention;

[0041] Figure 10 is a time-frequency diagram of the current during the startup phase described in the evaluation method of the present invention;

[0042] In the diagram: 1. Variable frequency power supply; 2. Industrial control computer; 3. Keyboard and mouse; 4. Emergency stop switch; 5. Main power switch; 6. Power selection switch; 7. Electrical parameter table; 8. Display; 9. Status indicator light; 10. Exhaust pressure gauge; 11. Unit high pressure gauge; 12. Intake pressure gauge; 13. Ambient temperature chamber; 14. Variable frequency compressor under test; 15. High temperature chamber; 16. Signal generator; 17. Electrical box door; 18. Electrical box; 19. Test refrigeration system; 20. Condensation chamber; 21. Ambient temperature chamber door;

[0043] 22. Ambient temperature valve, including 22-1, ambient temperature outlet valve, and 22-2, ambient temperature inlet valve;

[0044] 23. High-temperature valves, including 23-1, high-temperature outlet valve, and 23-2, high-temperature inlet valve;

[0045] 24. Exhaust pressure sensor;

[0046] 25. Large condenser coil valve, including 25-1, large condenser coil inlet valve, and 25-2, large condenser coil outlet valve;

[0047] 26. Small condenser coil valve, including 26-1, small condenser coil inlet valve, and 26-2, small condenser coil outlet valve;

[0048] 27. Large condenser coil; 28. Small condenser coil; 29. ​​Balancing valve; 30. Shut-off valve; 31. Expansion valve; 32. Evaporator coil; 33. Evaporator fan; 34. Suction pressure sensor; 35. Vacuum valve; 36. Vacuum pump; 37. Suction and discharge valve; 38. Check valve; 39. Suction and liquid filling valve; 40. Low-pressure end volume valve; 41. Low-pressure end volume regulator; 42. High-pressure end volume regulator; 43. High-pressure end volume valve; 44. Discharge and liquid filling valve; 45. Liquid filling needle valve; 46. Liquid filling manual valve; 47. Discharge and discharge valve; 48. Discharge needle valve; 49. Return manual valve; 50. Discharge manual valve; 51. Recovery manual valve; 52. Recovery storage tank; 53. Recovery condenser; 54. Oil separator; 55. Recovery pump; 56. Recovery valve 57. High-temperature ambient chamber heater; 58. Condensing chamber heater; 59. Printer; 60. Digital I / O control module; 61. High-speed AI sampling module; 62. Temperature sampling module; 63. AO output module; 64. Gas source undervoltage alarm signal; 65. Ambient over-temperature alarm signal; 66. Condensing chamber over-temperature alarm signal; 67. High-temperature ambient chamber cooling unit; 68. Low-pressure end volume regulation driver; 69. High-pressure end volume regulation driver; 70. UV voltage sensor; 71. VW voltage sensor; 72. WU voltage sensor; 73. Bus current sensor; 74. U-phase current sensor; 75. V-phase current sensor; 76. W-phase current sensor; 77. Vertical vibration sensor; 78. Horizontal vibration sensor; 79. Temperature sensor for high-temperature environmental chamber; 80. Temperature sensor for condenser chamber; 81. Temperature sensor for compressor housing; 82. Temperature sensor inside driver housing; 83. Temperature sensor for power module; 84. Temperature sensor for rectifier bridge; 85. Temperature sensor for filter capacitor; 86. Temperature sensor for radiator. Detailed Implementation

[0049] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0050] Conversely, this invention encompasses any substitutions, modifications, equivalent methods, and solutions made within the spirit and scope of the invention as defined in the claims. Furthermore, to provide a better understanding of the invention, certain specific details are described in detail below. However, those skilled in the art will fully understand the invention even without these detailed descriptions.

[0051] The external structure of an evaluation device for the start-up characteristics of a refrigeration compressor with adjustable system volume, as shown in Figure 1, includes a variable frequency compressor 14 under test and its driver, a test refrigeration system 19, and a test control system. The evaluation device adopts a dual-environment structure, providing two assembly stations for the test sample to offer different test temperature environments. During room temperature testing, the variable frequency compressor 14 and its driver are installed in a room temperature environment chamber 13; during high temperature testing, the variable frequency compressor 14 and its driver are installed in a high temperature environment chamber 15. An exhaust pressure gauge 10, a high-pressure gauge 11, and a suction pressure gauge 12 are installed on the top of the room temperature environment chamber 13. An emergency stop switch 4, a main power switch 5, a power selection switch 6, an electrical parameter table 7, a display 8, status indicator lights 9, and a signal generator 16 are located on the upper left side of the evaluation device. A variable frequency power supply 1, an industrial control computer 2, and a mouse and keyboard 3 are located on the lower left side of the evaluation device.

[0052] Figure 2 shows a side cross-section of a refrigeration compressor start-up characteristic evaluation device with adjustable system volume in this embodiment. An electrical box 18 with an electrical box door 17 is located on the left side of the evaluation device. An ambient temperature chamber 13 is located on the right side of the evaluation device, containing a sample mounting station and a test refrigeration system 19. The test refrigeration system 19 includes pipes, valves, a condenser chamber 20, etc. The ambient temperature chamber 13 has an ambient temperature chamber door 21 and a glass observation window.

[0053] This embodiment presents a device for evaluating the start-up characteristics of a refrigeration compressor with adjustable system volume. The structure of the refrigeration system 19 is shown in Figure 3, including a main circulation subsystem, a low-pressure end volume adjustment subsystem, a high-pressure end volume adjustment subsystem, a liquid charging subsystem, a discharge subsystem, a recovery subsystem, and a vacuuming subsystem. The test medium charged into the refrigeration system can be nitrogen or a refrigerant (R600a, R290, R1234yf, R134a, R404a, etc.).

[0054] In this embodiment, during the test of the main circulation subsystem of the refrigeration system, the exhaust port and suction port of the variable frequency compressor 14 under test are installed on the normal temperature outlet valve 22-1 and the normal temperature inlet valve 22-2, respectively, during the test of the high temperature condition. The ambient temperature outlet valve 22-1 and the high temperature outlet valve 23-1 are connected to the exhaust pressure sensor 24, the large condenser coil inlet valve 25-1, and the small condenser coil inlet valve 26-1, and then to the large condenser coil 27, the large condenser coil outlet valve 25-2, the small condenser coil 28, and the small condenser coil outlet valve 26-2, respectively. The large condenser coil outlet valve 25-2 and the small condenser coil outlet valve 26-2 are connected to the balance valve 29 and the shut-off valve 30, respectively. Then the shut-off valve 30 is connected to the expansion valve 31. The balance valve 29 and the expansion valve 31 are connected to the evaporator coil 32. The evaporator fan 33 is located in front of the evaporator coil 32. The evaporator coil 32 is connected to the suction pressure sensor 34, the ambient temperature inlet valve 22-2, and the high temperature inlet valve 23-2.

[0055] In this embodiment, the volume of the refrigeration system can be adjusted via a low-pressure end volume adjustment subsystem, a high-pressure end volume adjustment subsystem, and a condenser coil. In the low-pressure end volume adjustment subsystem, the low-pressure end volume regulator 41 is connected to the low-pressure end volume valve 40, which is connected to the evaporator coil 32, the balance valve 29, and the expansion valve 31. When the low-pressure end volume of the refrigeration system needs to be increased, the low-pressure end volume valve 40 is opened, and the range of volume increase is adjusted by the piston stroke of the low-pressure end volume regulator 41. In the high-pressure end volume adjustment subsystem, the high-pressure end volume regulator 42 is connected to the high-pressure end volume valve 43, which is connected to the ambient temperature outlet valve 22-1 and the high temperature outlet valve 23-1. When the high-pressure end volume of the refrigeration system needs to be increased, the high-pressure end volume valve 43 is opened, and the range of volume increase is adjusted by the piston stroke of the high-pressure end volume regulator 42. The liquid storage volume of the refrigeration system is adjusted via condenser coils. The switching of the large condenser coil inlet valve 25-1, large condenser coil outlet valve 25-2, and the small condenser coil inlet valve 26-1, small condenser coil outlet valve 26-2 allows for three combinations of liquid storage volumes: a single large condenser coil 27 volume, a single small condenser coil 28 volume, and a combination of large condenser coil 27 and small condenser coil 28. The large condenser coil 27 and small condenser coil 28 are located within the condensing chamber 20, which is equipped with a condenser heater 58. The condenser heater 58 regulates the temperature of the condensing chamber 20. When the temperature of the condensing chamber 20 is higher than the refrigerant condensation temperature, the refrigerant within the large condenser coil 27 and small condenser coil 28 vaporizes, thus regulating the gas-liquid state of the refrigerant inside.

[0056] In this embodiment, the refrigeration system automatically controls the amount of test medium charged into the pipeline through the adjustment of the liquid filling subsystem and the discharge subsystem. In the liquid filling subsystem, one end of the exhaust liquid filling valve 44 and the suction liquid filling valve 39 are connected to the ambient temperature outlet valve 22-1 and the ambient temperature inlet valve 22-2, respectively. The other end of the exhaust liquid filling valve 44 and the suction liquid filling valve 39 are connected to the liquid filling needle valve 45, which is then connected to the liquid filling manual valve 46. The liquid filling needle valve 45 controls the flow rate of the test medium entering the pipeline, preventing excessive pressure fluctuations in the system during the liquid filling process. In the discharge subsystem, one end of the exhaust discharge valve 47 and the suction discharge valve 37 are connected to the ambient temperature outlet valve 22-1 and the ambient temperature inlet valve 22-2, respectively. The other end of the exhaust discharge valve 47 and the suction discharge valve 37 are connected to the discharge needle valve 48, which is then connected to the discharge manual valve 50. The discharge needle valve 48 controls the flow rate of the test medium discharged from the pipeline, preventing excessive pressure fluctuations in the system during the discharge process.

[0057] This embodiment tests a refrigeration system that also features evacuation and recovery functions, implemented by a vacuuming subsystem and a recovery subsystem, respectively. In the vacuuming subsystem, one end of the evacuation valve 35 is connected to the ambient temperature inlet valve 22-2 and the high temperature inlet valve 23-2, while the other end is connected to the vacuum pump 36. When the refrigeration system requires evacuation, the evacuation valve 35 and the vacuum pump 36 are opened. In the recovery subsystem, one end of the recovery valve 56 is connected to the exhaust valve 47 and the suction valve 37, while the other end is connected to the recovery pump 55. Then, in sequence, the oil separator 54, the recovery condenser 53, the recovery liquid storage tank 52, and the recovery manual valve 51 are connected. The recovery liquid storage tank 52 is connected to the return manual valve 49, which in turn is connected to the liquid charging manual valve 46. The refrigerant recovered to the recovery liquid storage tank 52 can be reused by the refrigeration system, thereby improving the refrigerant utilization rate.

[0058] The hardware architecture of the test control system for an evaluation device for the start-up characteristics of a refrigeration compressor with adjustable system volume, as shown in Figure 4, is illustrated in this embodiment. The test control system uses an industrial control computer 2 as its control core to realize system control, data acquisition, and data processing of the entire evaluation device. The industrial control computer 2 uses a monitor 8, keyboard and mouse 3, and printer 59 as input / output devices to realize human-machine interaction and report printing for the evaluation device. The industrial control computer 2 uses a digital I / O control module 60 to realize digital input / output control of the evaluation device. The digital input signals include a gas source underpressure alarm signal 64, an ambient over-temperature alarm signal 65, and a condenser chamber over-temperature alarm signal 66. The digital outputs include: high temperature environment chamber heater 57, condenser heater 58, high temperature environment chamber cooling unit 67, frequency range of inverter power supply 1, voltage range of inverter power supply 1, ambient temperature valve 22, high temperature valve 23, balance valve 29, shut-off valve 30, recovery pump 55, recovery valve 56, vacuum pump 36, vacuum valve 35, suction liquid filling valve 39, suction discharge valve 37, discharge liquid filling valve 44, discharge discharge valve 47, low-pressure end volume valve 40, high-pressure end volume valve 43, low-pressure end volume regulating driver 68, high-pressure end volume regulating driver 69, large condenser coil valve 25, small condenser coil valve 26, and the inverter compressor under test 14 (digital output is 0 / 1 switch or high / low range signal). The industrial control computer 2 acquires data on the main start-up characteristic parameters of the tested variable frequency compressor through the high-speed AI sampling module 61, including sensor data from the suction pressure sensor 34, discharge pressure sensor 24, UV voltage sensor 70, VW voltage sensor 71, WU voltage sensor 72, bus current sensor 73, U-phase current sensor 74, V-phase current sensor 75, W-phase current sensor 76, vertical vibration acceleration sensor 77, and horizontal vibration acceleration sensor 77. The industrial control computer 2 acquires temperature data from key components of the tested variable frequency compressor 14 and its driver through the temperature sampling module 62, including sensor data from the high-temperature environmental chamber temperature sensor 79, condenser temperature sensor 80, compressor casing temperature sensor 81, driver casing temperature sensor 82, power module temperature sensor 83, rectifier bridge temperature sensor 84, filter capacitor temperature sensor 85, and radiator temperature sensor 86. The industrial control computer 2 automatically adjusts the voltage of the refrigeration system expansion valve 31 and the variable frequency power supply 1 through the AO output module 63. The industrial control computer 2 acquires the input voltage, current, power, frequency, and other electrical parameters of the driver of the variable frequency compressor 14 under test via the electrical parameter table 7. The industrial control computer 2 automatically adjusts the speed of the variable frequency compressor 14 under test via the signal generator 16.

[0059] In this embodiment, during the volume adjustment of the low-pressure and high-pressure sides of the refrigeration system, the low-pressure side volume adjustment driver 68 and the high-pressure side volume adjustment driver 69 receive a PWM pulse signal with a certain duty cycle generated by the digital I / O control module 60, and control the rotation angle of the stepper motors of the low-pressure side volume regulator 41 and the high-pressure side volume regulator 42, thereby adjusting the piston position of the low-pressure side volume regulator 41 and the high-pressure side volume regulator 42 to achieve system volume adjustment at the low-pressure and high-pressure sides.

[0060] This embodiment presents a method for evaluating the start-up characteristics of a refrigeration compressor with adjustable system volume. The evaluation process is shown in Figure 5 and includes the following steps:

[0061] Step 1: Installation of the tested variable frequency compressor and driver: In this embodiment, the tested sample is a fully enclosed reciprocating variable frequency refrigeration compressor and its variable frequency driver. The test environment temperature is room temperature. Place the tested variable frequency compressor 14 and driver in a room temperature environment chamber 13, and then connect the exhaust port and suction port of the tested variable frequency compressor 14 to the room temperature outlet valve 22-1 and the room temperature inlet valve 22-2.

[0062] Step 2: Setting Test Parameters and Test Mode: Before evaluating the startup characteristics, the test conditions are set. These parameters include exhaust pressure, intake pressure, ambient temperature, operating voltage, speed / frequency, and number of cycles. In this embodiment, the exhaust pressure is 0.36 MPa, the intake pressure is 0.36 MPa, the operating voltage is 220V, the speed / frequency is 120Hz, and the cycle test is set to 20 times. This embodiment uses a single-condition test mode, where the tested inverter compressor and driver undergo startup characteristic testing under the aforementioned set parameters.

[0063] Step 3: Refrigeration System Volume Adjustment: In this embodiment, the high-pressure end volume valve 43 is opened, and the stepper motor of the high-pressure end volume regulator 42 controls the internal piston to a set position, thereby adjusting the high-pressure end volume of the refrigeration system. The low-pressure end volume valve 40 is closed to adjust the low-pressure end volume of the refrigeration system. Simultaneously, the large condenser coil inlet valve 25-1 and the large condenser coil outlet valve 25-2 are closed, while the small condenser coil inlet valve 26-1 and the small condenser coil outlet valve 26-2 are opened to adjust the liquid storage volume of the refrigeration system. Finally, the volume adjustment of the entire refrigeration system is completed using the compressor start-up characteristic evaluation device.

[0064] Step 4: System Test Condition Adjustment: The suction and discharge pressure conditions of the variable frequency compressor start-up characteristic evaluation device are controlled by switching the discharge liquid filling valve 44, suction liquid filling valve 39, discharge valve 47, and suction discharge valve 37. The test environment temperature is normal temperature, and no temperature control is required. The operating voltage condition is controlled by the AO output module 63 to regulate the variable frequency power supply 1. The speed and frequency condition are controlled by the signal generator 16.

[0065] Step 5: Startup Characteristic Parameter Acquisition: In this embodiment, the high-speed AI sampling module of the test control system is set to an acquisition rate of 10KS / s. After the tested variable frequency compressor 14 and its driver are started, the high-speed AI sampling module 61 of the test control system begins to synchronously acquire various characteristic parameters, including suction and discharge pressure, phase-to-phase voltage, phase line current, vibration acceleration, etc. Simultaneously, the temperature sampling module 62 acquires other data, including the casing temperature of the variable frequency compressor, the casing temperature of the driver, the power module temperature, etc., and the electrical parameter table 7 acquires various electrical parameters input by the variable frequency driver. After the tested variable frequency compressor 14 has run for a certain period of time, the test control system shuts down the tested variable frequency compressor 14 and then determines whether the number of cycles has reached the set requirement. After the number of tests is reached, the startup characteristic evaluation begins.

[0066] Step 6: Start-up characteristic evaluation: Process the collected test data, evaluate the start-up characteristics of the tested variable frequency compressor 14 and its driver, generate a start-up characteristic evaluation report, and finally save the test data and report to the database.

[0067] This embodiment presents a method for evaluating the start-up characteristics of a refrigeration compressor with adjustable system volume. The evaluation of its transient start-up characteristics involves determining parameters such as suction and discharge pressures, vibration acceleration, phase-to-phase voltage, and phase line current. The suction and discharge pressures during the start-up process are shown in Figure 6. In this embodiment, the minimum suction pressure p of the tested variable frequency compressor is... smin The designed intake pressure threshold is 0.07 MPa. s The pressure should be 0.11 MPa; the suction pressure during the start-up process of the tested variable frequency compressor meets the design requirements. In this embodiment, the maximum value p of the tested variable frequency compressor discharge pressure is... dmax The designed exhaust pressure threshold is 2.12 MPa, p′. d The pressure is 0.97 MPa, and the discharge pressure during the start-up process of the tested variable frequency compressor meets the design requirements. The vibration acceleration during the start-up process is shown in Figure 7. The maximum vertical vibration acceleration a of the tested variable frequency compressor in this embodiment is... 1max It is 5.09 m / s 2 The vertical vibration acceleration threshold a′1 should be less than 1.0g (9.8 m / s²). 2 The vertical vibration acceleration during the start-up process of the tested variable frequency compressor meets the design requirements. The UV voltage during the start-up process is shown in Figure 8. In this embodiment, the maximum UV voltage U of the tested variable frequency compressor is... 1max The UV voltage is 136.82V, and the designed UV voltage threshold U′1 is 100-150V. The UV voltage during the start-up process of the tested variable frequency compressor meets the design requirements. The U-phase current during the start-up process is shown in Figure 9. The maximum value of the U-phase current of the tested variable frequency compressor in this embodiment is I. 2maxThe U-phase current threshold I′2 is designed to be 3.38 A and should be less than 4 A. The U-phase current during the startup process of the measured variable-frequency compressor meets the design requirements.

[0068] In this embodiment, a method for evaluating the startup characteristics of a refrigeration compressor with adjustable system volume. The evaluation of the startup non-transient characteristic parameters is the determination of parameters such as the shell temperature, the internal temperature of the variable-frequency drive, the power module temperature, the rectifier bridge temperature, the filter capacitor temperature, and the radiator temperature. During the startup process of the measured variable-frequency compressor, if the maximum value of each temperature is less than or equal to the designed threshold, it is determined to be qualified; otherwise, it is determined to be unqualified.

[0069] In this embodiment, a method for evaluating the startup characteristics of a refrigeration compressor with adjustable system volume evaluates the startup characteristics of the measured sample through the real-time speed during the startup stage. First, perform a time-frequency transformation on the phase current time-series signal of the measured variable-frequency compressor to obtain the time-frequency diagram of the phase current during the startup stage, as shown in Figure 10. The initial stage of the startup process in this embodiment can be divided into two stages, namely the positioning startup stage and the oiling platform stage. The designed time for the positioning startup stage should be less than 5 s, and the designed time for the oiling platform stage is generally 15 - 20 s, with a designed speed of 2000 - 2500 rpm. The rotor of the measured variable-frequency compressor in this embodiment has 3 pole pairs. Through the above formula (3), the real-time speed of the measured variable-frequency compressor can be calculated. The time T1 of the positioning startup stage of the measured variable-frequency compressor in this embodiment is 3.3 s, the time T2 of the oiling platform stage is 15.2 s, and the speed during the oiling platform stage is 2200 rpm. Therefore, the startup speed control of the measured variable-frequency compressor meets the design requirements.

[0070] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements, and improvements made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A device for evaluating the start-up characteristics of a refrigeration compressor with adjustable system volume, characterized in that, This includes the sample being tested, the test cooling system, and the test control system. The evaluation device adopts a dual-environment structure, setting up two assembly stations for the sample to be tested to provide different test temperature environments, namely a room temperature test environment and a high temperature test environment. The sample to be tested at the two assembly stations can be subjected to alternating tests at room temperature and high temperature. The test temperature of the room temperature test environment is the ambient temperature where the sample is located, and the test temperature range of the high temperature test environment is between the ambient temperature and 90°C. The tested sample includes the tested variable frequency compressor and driver. When the tested variable frequency compressor and driver are tested under normal temperature conditions, the tested sample is placed in the normal temperature environment chamber of the evaluation device. When the tested variable frequency compressor and driver are tested under high temperature conditions, the tested sample is placed in the high temperature environment chamber of the evaluation device. The test refrigeration system is capable of volume adjustment to meet the testing requirements of the sample for different refrigeration system volumes; the test refrigeration system includes a main circulation subsystem, a low-pressure end volume adjustment subsystem, a high-pressure end volume adjustment subsystem, a liquid addition subsystem, a discharge subsystem, a recovery subsystem, and a vacuum subsystem; The test and control system realizes the system control, data acquisition and data processing of the entire evaluation device; it includes an industrial control computer, a digital I / O control module, a high-speed AI sampling module, a temperature sampling module and an AO output module.

2. The system volume adjustable refrigeration compressor start-up characteristic evaluation device according to claim 1, characterized in that, The main circulation subsystem includes a normal temperature outlet valve (22-1), a normal temperature inlet valve (22-2), a high temperature outlet valve (23-1), a high temperature inlet valve (23-2), an exhaust pressure sensor (24), a large condensing coil (27), a large condensing coil inlet valve (25-1), a large condensing coil outlet valve (25-2), a small condensing coil (28), a small condensing coil inlet valve (26-1), a small condensing coil outlet valve (26-2), a balance valve (29), a shut-off valve (30), an expansion valve (31), an evaporator coil (32), an evaporator fan (33), and a suction pressure sensor (34). The ambient temperature outlet valve (22-1) and the high temperature outlet valve (23-1) are respectively connected to the exhaust pressure sensor (24), the large condensing coil inlet valve (25-1), and the small condensing coil inlet valve (26-1). The large condensing coil inlet valve (25-1) is connected to the inlet of the large condensing coil (27), and the outlet of the large condensing coil (27) is connected to the large condensing coil outlet valve (25-2). The small condensing coil inlet valve (26-1) is connected to the inlet of the small condensing coil (28), and the outlet of the small condensing coil (28) is connected to the small condensing coil outlet valve (26-2). The large condensing coil outlet valve (25-2) and the small condensing coil outlet valve (26-2) are respectively connected to the balance valve (29) and the stop valve (30). The stop valve (30) is connected to the expansion valve (31). The balance valve (29) and the expansion valve (31) are connected to the evaporator coil (32). The fan (33) is located in front of the evaporator coil (32), and the evaporator coil (32) is connected to the suction pressure sensor (34), the ambient temperature inlet valve (22-2), and the high temperature inlet valve (23-2) respectively. During normal temperature operation testing, the exhaust port and suction port of the variable frequency compressor (14) under test are installed on the normal temperature outlet valve (22-1) and the normal temperature inlet valve (22-2), respectively. During high temperature operation testing, the exhaust port and suction port of the variable frequency compressor (14) under test are installed on the high temperature outlet valve (23-1) and the high temperature inlet valve (23-2), respectively. The large condensing coil (27) and the small condensing coil (28) are respectively installed in the condensing chamber (20). The condensing chamber (20) is equipped with a condensing heater (58). The condensing heater (58) regulates the temperature of the condensing chamber (20). When the temperature of the condensing chamber (20) is higher than the refrigerant condensation temperature, the refrigerant in the large condensing coil (27) and the small condensing coil (28) vaporizes, which has a regulating effect on the gas-liquid state of the refrigerant inside.

3. The system volume adjustable refrigeration compressor start-up characteristic evaluation device according to claim 2, characterized in that, The low-pressure end volume regulation subsystem includes a low-pressure end volume valve (40) and a low-pressure end volume regulator (41); the low-pressure end volume regulator (41) is connected to the low-pressure end volume valve (40), and the low-pressure end volume valve (40) is connected to the evaporator coil (32), the balance valve (29), and the expansion valve (31) respectively. The high-pressure end volume regulation subsystem includes a high-pressure end volume valve (43) and a high-pressure end volume regulator (42); the high-pressure end volume regulator (42) is connected to the high-pressure end volume valve (43), and the high-pressure end volume valve (43) is connected to the ambient temperature outlet valve (22-1) and the high temperature outlet valve (23-1) respectively. The volume of the test refrigeration system is adjusted through the low-pressure end volume regulation subsystem, the high-pressure end volume regulation subsystem, and the condenser coil; When the volume of the low-pressure side of the refrigeration system needs to be increased, the low-pressure side volume valve (40) is opened, and the range of volume increase is adjusted by the piston stroke of the low-pressure side volume regulator (41). When the volume of the high-pressure end of the refrigeration system needs to be increased, the high-pressure end volume valve (43) is opened, and the range of volume increase is adjusted by the piston stroke of the high-pressure end volume regulator (42); The liquid storage volume of the test refrigeration system is adjusted by the condenser coil. The opening and closing of the large condenser coil inlet valve (25-1), the large condenser coil outlet valve (25-2), the small condenser coil inlet valve (26-1), and the small condenser coil outlet valve (26-2) can achieve three combinations of liquid storage volume: the volume of a single large condenser coil (27), the volume of a single small condenser coil (28), and the volume of a large condenser coil (27) plus a small condenser coil (28).

4. The system volume adjustable refrigeration compressor start-up characteristic evaluation device according to claim 2, characterized in that, The liquid filling subsystem includes a one-way valve, an intake liquid filling valve (39), an exhaust liquid filling valve (44), a liquid filling needle valve (45), and a liquid filling manual valve (46); one end of the exhaust liquid filling valve (44) and the intake liquid filling valve (39) are respectively connected to the ambient temperature outlet valve (22-1) and the ambient temperature inlet valve (22-2), and the other end of the exhaust liquid filling valve (44) and the intake liquid filling valve (39) are connected to the liquid filling needle valve (45), and the liquid filling needle valve (45) is then connected to the liquid filling manual valve (46); The emission subsystem includes a one-way valve (38), an intake emission valve (37), an exhaust emission valve (47), an emission needle valve (48), and an emission manual valve (50); one end of the exhaust emission valve (47) and the intake emission valve (37) are respectively connected to the ambient temperature outlet valve (22-1) and the ambient temperature inlet valve (22-2), and the other end of the exhaust emission valve (47) and the intake emission valve (37) are connected to the emission needle valve (48), and the emission needle valve (48) is then connected to the emission manual valve (50); The recovery subsystem includes a return hand valve (49), a recovery hand valve (51), a recovery storage tank (52), a recovery condenser (53), an oil separator (54), a recovery pump (55), and a recovery valve (56). One end of the recovery valve (56) is connected to the exhaust valve (47) and the intake valve (37), and the other end of the recovery valve (56) is connected to the recovery pump (55). Then, the oil separator (54), the recovery condenser (53), the recovery storage tank (52), and the recovery hand valve (51) are connected in sequence. The recovery storage tank (52) is connected to the return hand valve (49), and the return hand valve (49) is connected to the liquid filling hand valve (46). The refrigerant recovered to the recovery storage tank (52) is used in the refrigeration system for reuse, thereby improving the utilization rate of the refrigerant. The vacuum subsystem includes a vacuum valve (35) and a vacuum pump (36); one end of the vacuum valve (35) is connected to the ambient temperature inlet valve (22-2) and the high temperature inlet valve (23-2) respectively, and the other end of the vacuum valve (35) is connected to the vacuum pump (36). When the refrigeration system needs to be vacuumed, the vacuum valve (35) and the vacuum pump (36) are opened.

5. The system volume adjustable refrigeration compressor start-up characteristic evaluation device according to claim 1, characterized in that, The industrial control computer realizes digital input and output control of the evaluation device through the digital I / O control module; realizes high-speed synchronous acquisition of transient characteristic parameters of the tested variable frequency compressor through the high-speed AI sampling module; realizes acquisition of non-transient characteristic parameters of the tested variable frequency compressor and driver, as well as temperature data of corresponding parts of the evaluation device through the temperature sampling module; and realizes automatic adjustment of the expansion valve and variable frequency power supply voltage of the test refrigeration system through the AO output module.

6. The system volume adjustable refrigeration compressor start-up characteristic evaluation device according to claim 5, characterized in that, The transient characteristic parameters include the discharge pressure, intake pressure, vertical vibration acceleration, horizontal vibration acceleration of the variable frequency compressor under test, and the UV voltage, VW voltage, WU voltage, bus current, U-phase current, V-phase current, and W-phase current input to the variable frequency compressor. The non-transient characteristic parameters include the casing temperature of the variable frequency compressor under test, the casing temperature of the driver, the power module temperature, the rectifier bridge temperature, the filter capacitor temperature, and the heat sink temperature.

7. A method for evaluating the start-up characteristics of a refrigeration compressor with adjustable system volume, characterized in that, Includes the following steps: Step 1: Installation of the variable frequency compressor and driver under test: Determine the environmental temperature requirements for the test sample; for ambient temperature testing, place the variable frequency compressor and driver under test in an ambient temperature chamber; for high temperature testing, place the variable frequency compressor and driver under test in a high temperature chamber, and then complete the connection of the suction and exhaust pipes and electrical circuits of the variable frequency compressor under test. Step 2, Test Parameters and Test Mode Settings: Before starting the performance evaluation, the test conditions are set. The test conditions parameters include exhaust pressure, intake pressure, ambient temperature, operating voltage, speed frequency, and number of cycles. There are two test modes: single-condition test and multi-condition test. Step 3, Refrigeration system volume adjustment: Based on the matching between the sample under test and the test refrigeration system, determine the system volume for evaluating the start-up characteristics of the variable frequency compressor under test. Then, by adjusting the piston positions of the high-pressure end volume regulator and the low-pressure end volume regulator, as well as the opening and closing of the inlet and outlet valves of the large condensing coil and the small condensing coil, the volume adjustment of the entire test refrigeration system of the refrigeration compressor start-up characteristics evaluation device is completed. Step 4: System test condition adjustment: The test conditions for evaluating the start-up characteristics of the sample under test are automatically adjusted. When all test parameters meet the set requirements, the variable frequency compressor under test is started by the driver. Step 5: Start up characteristic parameter acquisition: After the tested variable frequency compressor starts, the test control system realizes high-speed synchronous acquisition of transient characteristic parameters of the tested variable frequency compressor through the high-speed AI sampling module; it realizes acquisition of non-transient characteristic parameters of the tested variable frequency compressor and driver, as well as temperature data of corresponding parts of the evaluation device through the temperature sampling module; after the tested variable frequency compressor runs for a specified time, the test control system shuts down the tested variable frequency compressor and then judges whether the number of cycles has reached the set requirements. Step 6: Start-up characteristic evaluation: Process the collected test data, evaluate the start-up characteristics of the tested variable frequency compressor and drive, generate a start-up characteristic evaluation report, and finally save the test data and report to the database.

8. The method for evaluating the start-up characteristics of a refrigeration compressor with adjustable system volume according to claim 7, characterized in that, In step 6, the starting characteristics of the tested variable frequency compressor and driver are evaluated by starting transient characteristic parameters: namely, the determination of suction and discharge pressure, vibration acceleration, phase-to-phase voltage, and phase line current parameters. During the startup process of the measured variable-frequency compressor, if the suction pressure p s 's minimum value p s min is less than or equal to the designed threshold p′ s , it is determined that the suction pressure is qualified; otherwise, it is determined as unqualified. If the discharge pressure p d 's maximum value p d max is greater than or equal to the designed threshold p′ d , it is determined that the discharge pressure is qualified; otherwise, it is determined as unqualified. If the vibration acceleration a i 's maximum value a imax is less than or equal to the designed threshold a′ i , it is determined that the vibration acceleration is qualified; otherwise, it is determined as unqualified. If the phase-to-phase voltage U j 's maximum value U jmax is less than or equal to the designed threshold U′ j , it is determined that the phase-to-phase voltage is qualified; otherwise, it is determined as unqualified. If the phase current I k 's maximum value I kmax is less than or equal to the designed threshold I′ k , it is determined that the phase current is qualified; otherwise, it is determined as unqualified. The specific determination conditions are shown in formula (1): In the formula, a1 is the vertical vibration acceleration, a′1 is the design threshold for vertical vibration acceleration; a2 is the horizontal vibration acceleration, a′2 is the design threshold for horizontal vibration acceleration; U1 is the UV voltage, U′1 is the UV voltage design threshold; U2 is the VW voltage, U′2 is the VW voltage design threshold; U3 is the WU voltage, U′3 is the WU voltage design threshold; I1 is the bus current, I′1 is the bus current design threshold; I2 is the U-phase current, I′2 is the U-phase current design threshold; I3 is the V-phase current, I′3 is the V-phase current design threshold; I4 is the W-phase current, I′4 is the W-phase current design threshold.

9. The method for evaluating the start-up characteristics of a refrigeration compressor with adjustable system volume according to claim 7, wherein in step 6, the start-up characteristics of the tested variable frequency compressor and driver are evaluated by non-transient start-up characteristic parameters: namely, the determination of parameters such as casing temperature, driver casing temperature, power module temperature, rectifier bridge temperature, filter capacitor temperature, and radiator temperature. During the startup process of the tested variable frequency compressor, if the maximum value T of each temperature is... imax Less than or equal to the design threshold T′ i , it is judged as qualified, otherwise it is judged as unqualified; the specific judgment conditions are shown in formula (2): T imax ≤T′ i i=1,2,3,4,5,6 (2); In the formula, T1 is the housing temperature, and T′1 is the housing temperature design threshold; T2 is the internal temperature of the frequency converter driver, and T′2 is the internal temperature design threshold of the frequency converter driver; T3 is the power module temperature, and T′3 is the power module temperature design threshold; T4 is the rectifier bridge temperature, and T′4 is the rectifier bridge temperature design threshold; T5 is the filter capacitor temperature, and T′5 is the filter capacitor temperature design threshold; T6 is the heat sink temperature, and T′6 is the heat sink temperature design threshold.

10. The method for evaluating the start-up characteristics of a refrigeration compressor with adjustable system volume according to claim 7, characterized in that, In step 6, the starting characteristics of the tested variable frequency compressor and driver are evaluated by the real-time speed during the startup phase: first, the phase current of the tested variable frequency compressor is transformed by time and frequency to obtain the time and frequency diagram of the current during the startup phase, and then the real-time speed of the tested variable frequency compressor is obtained. The startup characteristics are judged to meet the design requirements by the real-time speed curve during the startup phase. The real-time speed of the tested variable frequency compressor is calculated as shown in formula (3): In the formula, n is the speed of the variable frequency compressor under test, and f is the current frequency of the variable frequency compressor under test.

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