Suction temperature control system for positive displacement refrigerant compressor performance testing

Abstract

The present invention relates to an intake temperature control system for testing the performance of a positive displacement refrigerant compressor, comprising an exhaust port of a tested compressor, an oil separator, a calorimeter, and an intake port of the tested compressor, which are connected in sequence, and a superheater, wherein the superheater is connected and arranged between the calorimeter and the tested compressor, and the oil discharge port of the oil separator is connected to the front end of the superheater. The present invention adds a superheater to the original refrigerant compressor performance test system, separates the intake temperature control from the output power measurement of the calorimeter electric heater, increases the superheat at the calorimeter outlet, allows the refrigerant to fully evaporate, avoids errors caused by incomplete evaporation of the refrigerant when testing a small superheat, and improves the reliability of the measurement.

Description

Technical Field

[0001] The invention relates to the field of performance testing technology for volumetric refrigerant compressors, and is an intake temperature control system applied to the second refrigerant calorimeter method. Background Art

[0002] In the performance test of positive displacement refrigerant compressors, in some small superheat test conditions, the refrigerant will be in a gas-liquid two-phase state at the calorimeter outlet that has not been completely evaporated. The gas-liquid two-phase at the calorimeter outlet leads to inaccurate measurement of the enthalpy value at the calorimeter outlet, affecting the stability of control in the compressor performance test and the accuracy of the capacity test. This phenomenon will become more serious as the compressor suction superheat decreases and the compressor oil circulation rate increases. At present, in order to improve the energy efficiency of compressor development, there is an increasing demand for small suction superheat tests. In addition, variable frequency compressors have become mainstream. Compared with fixed frequency compressors, variable frequency compressors have a higher oil circulation rate at high frequencies. The contradiction between actual test needs and current tests is becoming more and more acute. Summary of the invention

[0003] The object of the present invention is to provide an intake temperature control system for testing the performance of a positive displacement refrigerant compressor, the system controls the outlet temperature of the refrigerant of a calorimeter and sets the temperature to be equal to the temperature before the throttle valve of the calorimeter; a superheater is added between the outlet of the calorimeter and the suction port of the compressor to independently control the intake temperature, thereby realizing the separation of the compressor refrigerant flow calculation and the compressor intake temperature control by the second calorimeter method; at the same time, a high-efficiency oil separator is used to filter out the compressor exhaust oil, and the oil separated from the oil separator is injected into the outlet of the calorimeter and re-enters the compressor cycle.

[0004] The present invention adopts the following technical solutions:

[0005] A suction temperature control system for testing the performance of a positive displacement refrigerant compressor comprises an exhaust port of a tested compressor 1, an oil separator 2, and a calorimeter 6 connected in sequence, and the suction port of the tested compressor 1 also comprises a superheater 7, wherein the superheater 7 is connected and arranged between the calorimeter 6 and the tested compressor 1, and the oil discharge port of the oil separator 2 is connected to the front end of the superheater 7.

[0006] Preferably, a first temperature measuring point g2 is set at the outlet of the heat exchanger in the calorimeter 6, and a second temperature measuring point T2 is set in front of the throttle valve at the inlet of the heat exchanger in the calorimeter 6. The first temperature measuring point g2 and the second temperature measuring point T2 are controlled by the heater in the calorimeter so that the temperature of the first temperature measuring point g2 is equal to that of the second temperature measuring point T2.

[0007] Preferably, the interior of the superheater 7 is a three-layer structure, the top layer is a cooling heat exchanger, the middle layer is a superheating heat exchanger, and the bottom layer is a balancing electric heater. The suction temperature of the compressor 1 under test is controlled by adjusting the output ratio of the balancing electric heater; the refrigerant is filled outside the heat exchanger tube inside the superheater as a heat exchange medium.

[0008] Preferably, it also includes a first condenser 3, a liquid storage device 4, and a second subcooler 5 which are connected in sequence and arranged between the oil separator 2 and the calorimeter 6.

[0009] Preferably, a first valve is provided before the calorimeter 6 .

[0010] The beneficial effects of the present invention are:

[0011] 1) A superheater is added to the original refrigerant compressor performance test system to separate the suction temperature control and the calorimeter electric heater output power measurement, increase the superheat at the calorimeter outlet, and allow the refrigerant to fully evaporate, avoiding errors caused by incomplete refrigerant evaporation when testing low superheat, thereby improving the reliability of the measurement.

[0012] 2) By setting the calorimeter outlet temperature and the temperature before the calorimeter valve to be consistent, the calorimeter power test deviation caused by the change of oil temperature in the system can be avoided.

[0013] 3) Use an oil filter to filter out the oil in the system to prevent the oil from entering the main system of the calorimeter and affecting the accuracy of the measurement.

[0014] 4) Re-inject the oil into the front end of the superheater to fully mix with the refrigerant. The oil-refrigerant mixture reaches the same suction temperature of the tested compressor after heat exchange in the superheater. This method can avoid the test error caused by incomplete evaporation of the refrigerant in the calorimeter under low superheat conditions.

[0015] 5) By setting and controlling the outlet temperature of the calorimeter, the refrigerant at the outlet of the calorimeter is fully evaporated, which improves the accuracy of the second refrigerant calorimeter method in measuring the refrigeration capacity of the measured compressor. It has the advantages of stable system operation and high measurement accuracy. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a structural schematic diagram of an intake temperature control system for testing the performance of a positive displacement refrigerant compressor of the present invention.

[0017] In the figure, 1. compressor under test, 2. oil separator, 3. first condenser, 4. liquid receiver, 5. second subcooler, 6. calorimeter, 7. superheater. DETAILED DESCRIPTION

[0018] The present invention is further described below in conjunction with the accompanying drawings and specific embodiments.

[0019] In this embodiment, a superheater and a high-efficiency oil separator are added to the traditional test system, and the control method is improved, including a tested compressor 1, an oil separator 2, a first condenser 3, a liquid storage device 4, a second subcooler 5, a calorimeter 6, and a superheater 7 connected in sequence.

[0020] A temperature measuring point is set at the outlet of the heat exchanger in the calorimeter 6, and the set temperature of the temperature measuring point is consistent with the set temperature before the inlet valve of the heat exchanger in the calorimeter 6.

[0021] A superheater 7 is set between the calorimeter 6 and the compressor 1 under test. The superheater 7 has a three-layer structure. The top layer is a cooling heat exchanger, the middle layer is a superheating heat exchanger, and the bottom layer is a balanced electric heater. The suction temperature of the compressor 1 under test is controlled by adjusting the output ratio of the electric heating; the refrigerant is filled outside the heat exchanger tube inside the superheater as a heat exchange medium.

[0022] A high-efficiency oil separator 2 is provided at the outlet of the compressor 1 to be tested, and the filtered oil is input into the pipeline between the calorimeter 6 and the superheater 7.

[0023] like Figure 1 As shown, the suction temperature control system for the performance test of the positive displacement refrigerant compressor works as follows:

[0024] The compressor 1 under test sucks in the superheated refrigerant gas from the superheater 7, and then continues to compress it into a high-temperature and high-pressure superheated refrigerant gas. The high-temperature and high-pressure refrigerant gas passes through the high-efficiency oil separator 2 and is condensed into a high-temperature and high-pressure refrigerant liquid through the first condenser 3. The refrigerant liquid passes through the liquid storage 4 and enters the second subcooler 5. After passing through the subcooler, the refrigerant temperature can be controlled to the set calorimeter valve front temperature. The refrigerant evaporates into superheated gas in the calorimeter 6. The temperature of the refrigerant superheated gas at the calorimeter outlet is controlled by adjusting the output ratio of the electric heating in the calorimeter (6). The set value of the refrigerant temperature at the calorimeter outlet is consistent with the set value of the calorimeter valve front temperature. The refrigerant superheated gas at the calorimeter outlet and the oil in the oil separator are mixed and enter the superheater 7. The superheater 7 is divided into a three-layer structure. The top layer is a cooling heat exchanger, the middle layer is a superheating heat exchanger, and the bottom layer is a balanced electric heating. The refrigerant is filled outside the heat exchanger tube inside the superheater as a heat exchange medium. The suction temperature of the tested compressor 1 is controlled by adjusting the electric heating output ratio. The superheater has both heating and cooling functions, and can accurately adjust the temperature of the refrigerant sucked into the tested compressor 1.

[0025] The present invention adds a superheater on the basis of the original refrigerant compressor performance test system, separates the suction temperature control and the output power measurement of the calorimeter electric heater, increases the superheat at the outlet of the calorimeter, allows the refrigerant to fully evaporate, avoids the error caused by incomplete refrigerant evaporation when testing a small superheat, and improves the reliability of the measurement. Setting the outlet temperature to be consistent with the temperature before the calorimeter valve can avoid the calorimeter power test deviation caused by the change of the oil temperature in the system. Use a high-efficiency oil filter to filter out the oil in the system to prevent the oil from entering the main system and affecting the accuracy of the measurement. The oil is re-injected into the front end of the superheater to be fully mixed with the refrigerant, and the oil-refrigerant mixture reaches the same suction temperature of the tested compressor after heat exchange in the superheater. This method can avoid the test error caused by incomplete evaporation of the refrigerant in the calorimeter under the condition of small superheat. By setting and controlling the outlet temperature of the calorimeter, the refrigerant at the outlet of the calorimeter is fully evaporated, which improves the accuracy of the second refrigerant calorimeter method in measuring the refrigeration capacity of the tested compressor. It has the advantages of stable system operation and high measurement accuracy.

[0026] The above are preferred embodiments of the present invention. A person skilled in the art may make various changes or improvements on this basis. Without departing from the general concept of the present invention, these changes or improvements should fall within the scope of protection claimed by the present invention.

Claims

1. A suction temperature control system for testing the performance of a positive displacement refrigerant compressor, comprising an exhaust port of a tested compressor (1), an oil separator (2), a calorimeter (6) connected in sequence, and an air intake port of the tested compressor (1), characterized in that: It also includes a superheater (7), the superheater (7) being connected and arranged between the calorimeter (6) and the compressor (1) to be tested, and the oil discharge port of the oil separator (2) being connected to the front end of the superheater (7); A first temperature measuring point (g2) is provided at the outlet of the heat exchanger in the calorimeter (6), and a second temperature measuring point (T2) is provided at the inlet of the heat exchanger in the calorimeter (6). The first temperature measuring point (g2) and the second temperature measuring point (T2) are controlled by a heater in the calorimeter so that the temperature of the first temperature measuring point (g2) and the second temperature measuring point (T2) are equal; The interior of the superheater (7) is a three-layer structure, the top layer is a cooling heat exchanger, the middle layer is a superheating heat exchanger, and the bottom layer is a balancing electric heater. The suction temperature of the compressor (1) under test is controlled by adjusting the output ratio of the balancing electric heater; the heat exchanger tube inside the superheater (7) is filled with refrigerant as a heat exchange medium.

2. The suction temperature control system for testing the performance of a positive displacement refrigerant compressor according to claim 1, characterized in that: It also includes a first condenser (3), a liquid storage device (4), and a second subcooler (5) which are arranged between the oil separator (2) and the calorimeter (6) and are connected in sequence.

3. The suction temperature control system for testing the performance of a positive displacement refrigerant compressor according to claim 1, characterized in that: A first valve is provided before the calorimeter (6).

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