CN115523130A - A Method of Compressor Reliability Evaluation - Google Patents

Abstract

The invention relates to a method for evaluating the reliability of a compressor, which belongs to the technical field of detection. Including: a. Connect the balance valve (4) and expansion valve (5) in parallel to the inlet and outlet of the compressor (1), open the balance valve (4) to vacuumize; b. Add refrigerant until the pressure reaches 0.3-0.45MPa , close the balance valve (4), start the compressor (1); c, adjust the expansion valve (5) to make the suction pressure reach 0.55-0.6MPa, and shut down after the exhaust pressure reaches 1.5-1.7MPa; d, open the balance valve (4) After the pressure is balanced, close the balance valve (4), restart the compressor (1), and repeat steps c; e, open the shell and check the components of the compressor (1). After the method ends, the parts are directly inspected, the reliability evaluation is realized, and the operation is simple and the detection is fast. The problem that the existing compressor (1) life test method cannot effectively evaluate the reliability of mechanical parts of the compressor (1) is solved.

Description

A Method of Compressor Reliability Evaluation

technical field

The invention relates to a method for evaluating the reliability of a compressor, which belongs to the technical field of compressor detection.

Background technique

In the production process of refrigeration appliances such as refrigerators and freezers, it is necessary to charge a large amount of refrigerant into the compressor in a short period of time, and then immediately turn on the power for a start-up test. After the system is filled with refrigerant, a large amount of refrigerant evaporates rapidly, and the temperature of the compressor core drops, resulting in changes in the fit clearance of the compressor. At the same time, the refrigerant has not yet volatilized into the refrigeration system, and a large amount of liquid refrigerant is mixed in the refrigeration oil of the compressor, and the viscosity of the refrigeration oil decreases, which is not conducive to the formation of an oil film on the surface of the mechanical motion pair. At this time, when the system pressure is not balanced, the load of the compressor increases; the pump oil system of the compressor sucks refrigeration oil mixed with refrigerant into the moving pair, and the refrigerant cleans the oil film on the surface of the moving pair, making the The thickness of the oil film is reduced, or even unable to form, resulting in poor lubricity of the compressor; under the simultaneous action of increased load and poor lubricity, it is easy to cause damage to the mechanical parts of the compressor, and the existing life test methods cannot effectively evaluate the reliability of the mechanical parts of the compressor .

Contents of the invention

The technical problem to be solved by the present invention is that the existing compressor life test method cannot effectively evaluate the reliability of mechanical parts of the compressor.

The technical scheme that the present invention adopts to solve its technical problem is: a kind of method for compressor reliability evaluation, comprises the steps:

a. Connect the test device, connect the balance valve and expansion valve in parallel to the inlet and outlet of the compressor, open the balance valve and vacuum the system;

b. Add refrigerant, wait until the equilibrium pressure reaches 0.3-0.45MPa, close the balance valve, and start the compressor;

c. Adjust the expansion valve so that the suction pressure of the system reaches 0.55-0.6MPa, and the exhaust pressure reaches 1.5-1.7MPa, then shut down the compressor to run;

d. Open the balance valve to balance the system pressure, then close the balance valve to restart the compressor, and repeat step c;

e. Open the shell and check the mechanical parts of the compressor.

Wherein, in the above method, the inlet and outlet pipes of the compressor are respectively provided with a suction pressure gauge and a discharge pressure gauge.

Wherein, the system is evacuated to -0.12 to -0.08MPa in step a of the above method.

Further, the degree of vacuum in step a in the above method is measured by gauge pressure.

Wherein, in the step b of the above method, a refrigerant cylinder is used to add refrigerant, and the refrigerant is liquid R314a.

Wherein, in the above method, the inlet and outlet pipes of the compressor are respectively provided with a suction valve and an exhaust valve.

Wherein, the pressure in step b and/or c in the above method is gauge pressure.

Wherein, step c needs to be repeated once or twice in step d in the above method.

The beneficial effect of the invention is that: the test method of the method is used to evaluate the reliability of mechanical components of the compressor when the compressor is filled with large flow or liquid refrigerant, the load increases and the lubricity is poor. In fact, by continuously starting and stopping the compressor, after the test, the compressor is opened to check whether the parts are abnormally damaged or worn, thereby realizing the evaluation of the reliability of the compressor, which has the advantages of simple operation and fast detection.

Description of drawings

Fig. 1 is a schematic diagram of the system connection structure of the present invention.

The marks in the figure are: 1 is the compressor, 2 is the exhaust pressure gauge, 3 is the exhaust valve, 4 is the balance valve, 5 is the expansion valve, 6 is the suction valve, and 7 is the suction pressure gauge.

detailed description

The present invention will be further described below in conjunction with the accompanying drawings.

As shown in Figure 1, a kind of method for compressor reliability evaluation of the present invention, comprises the following steps:

a. Connect the test device, connect the balance valve 4 and the expansion valve 5 in parallel to the inlet and outlet of the compressor 1, open the balance valve 4 and vacuumize the system;

b. Add refrigerant, wait until the equilibrium pressure reaches 0.3-0.45MPa, close the balance valve 4, and start the compressor 1;

c. Adjust the expansion valve 5 to make the suction pressure of the system reach 0.55-0.6MPa, and shut down the compressor 1 after the exhaust pressure reaches 1.5-1.7MPa;

d. Open the balance valve 4 to balance the system pressure, then close the balance valve and restart the compressor 1, and repeat step c to stop the compressor 1;

e. Open the shell and check the mechanical parts of compressor 1. Those skilled in the art can understand that this method is mainly to control the pressure of each step. During the test, the gas cylinder is not closed. During the simulation of the lift of the refrigerator, after a large amount of refrigerant is charged in a short period of time, the compressor will start immediately, which will affect the compression. Damage to machine parts. In order to detect the loss of the internal components of the compressor 1 cold start refrigerant, so in order to simulate the real start, this method first needs to be independently connected to the test device, specifically in step a, the balance valve 4 and the expansion valve 5 are connected in parallel and then connected to the compressor 1 The inlet and outlet of compressor 1 are connected so that the inlet and outlet of compressor 1 communicate with balance valve 4 and expansion valve 5 respectively. Balance valve 4 and expansion valve 5 are mainly used to adjust the pressure of the entire compressor system. At the same time, in order to ensure that the refrigerant is charged, it is preferable to open the balance valve 4 and vacuumize the system before starting the compressor, so that the entire test device is in a negative pressure environment. Step b is mainly to charge in the refrigerant and start the compressor 1 . In step c, the expansion valve 5 is adjusted so that the pressure at the inlet and outlet of the compressor 1 reaches its working pressure, so as to ensure that the test data is more realistic. Step d verifies the working condition of the compressor 1, and repeats step c to ensure the authenticity of the data. Step e directly checks the damage degree of the components of the compressor 1 by opening the shell, and then determines whether it can meet the process requirements.

Preferably, in the above method, the inlet and outlet pipes of the compressor 1 are respectively provided with a suction pressure gauge 7 and a discharge pressure gauge 2 . Those skilled in the art can understand that, in order to measure the pressure on the inlet and outlet pipelines of the compressor 1 conveniently, in this method, the suction pressure gauge 7 and the discharge pressure gauge 2 are preferably arranged on the corresponding compressor 1 inlet and outlet pipelines.

Preferably, the step a in the above method is evacuated to -0.12 to -0.08MPa. Those skilled in the art can understand that, in order to ensure the filling of the refrigerant, it is preferable to vacuumize to -0.12 to -0.08MPa in step a

Preferably, the degree of vacuum in step a in the above method is measured by gauge pressure. Those skilled in the art can understand that, in order to display the vacuum degree of the system conveniently and in time, it can actually be directly measured by a vacuum gauge.

Preferably, in the step b of the above method, a refrigerant cylinder is used to add refrigerant, and the refrigerant is liquid R314a. Those skilled in the art can understand that, in order to facilitate the filling of refrigerant, this method preferably uses a refrigerant gas cylinder to hold refrigerant, so that the refrigerant gas cylinder is actually inverted and the nozzle of the refrigerant bottle is connected to the interface of the test device, and the opening Fill the gas cylinder valve with liquid R134a refrigerant into the refrigeration system. When the equilibrium pressure reaches 0.3-0.45MPa, close the balance valve 4, then start the compressor 1 to run, and at the same time, just put the gas cylinder upright.

Preferably, in the above method, the inlet and outlet pipes of the compressor 1 are respectively provided with a suction valve 6 and an exhaust valve 3 . Those skilled in the art can understand that, in order to facilitate the suction and exhaust of the test device, it is preferable to respectively set the suction valve 6 and the discharge valve 3 on the inlet and outlet pipes of the compressor 1 .

Preferably, the pressures in steps b and/or c in the above method are all gauge pressures. Those skilled in the art can understand that, in order to facilitate pressure measurement, it is preferable that the balance pressure, suction pressure and exhaust pressure are all gauge pressures, which can be actually measured by pressure gauges.

Preferably, step c needs to be repeated once or twice in step d in the above method. Those skilled in the art can understand that, in order to facilitate the observation of the wear of the internal components of the compressor 1 , in this method, it is preferable to repeat step c once or twice in step d to simulate actual working conditions.

Example 1

The compressor 1 is connected to the testing device, the balance valve 4 and the expansion valve 5 are connected in parallel and then connected to the inlet and outlet of the compressor 1, and the balance valve 4 is opened to evacuate the system to -0.1MPa (gauge pressure). Turn the gas cylinder upside down, fill it with liquid R134a refrigerant to make the equilibrium pressure reach 0.43MPa (gauge pressure), close the balance valve 4, start the compressor 1, and at the same time put the gas cylinder upright. Adjust the expansion valve 5 to make the suction pressure of the system reach 0.57MPa (gauge pressure), stop the operation of compressor 1 after the exhaust pressure reaches 1.6MPa (gauge pressure), open the balance valve 4 to balance the system pressure, and the balance pressure is 0.60MPa (gauge pressure) pressure), close the balance valve 4 and restart compressor 1, adjust the expansion valve 5 to make the suction pressure of the system reach 0.6MPa (gauge pressure), and stop the operation of compressor 1 after the exhaust pressure reaches 1.68MPa (gauge pressure). Open the shell to check whether the mechanical parts are abnormally damaged or worn. After opening the shell, it is found that the elastic pin is broken, the small end of the connecting rod and the piston pin are severely worn, and the wear reaches level 5.

Among them, the evaluation standard for parts wear is 0-5 grades, and ≤3 grades are qualified. The specific requirements are as follows:

0-Looks like new: no polish, no signs of wear;

1- Very slight wear: there is very slight polishing in some parts, no defects on the surface, no scratches;

2-Slight wear: There is slight polishing, slight scratches in a small area, and the surface of the slightly damaged surface is smoother than the original surface;

3- Moderate wear: moderately scratched, moderately polished, no surface cracks, no scratches, no chipping marks;

4-Slightly aggressive wear: moderate scratches, light abrasive wear, light scratches, heavy burnishing, slight surface cracking;

5- Aggressive Severe Wear: Severe scratches, severe abrasive wear, scratches, gouges, surface cracks, surface damage, very severe burnishing, corrosion, bonding.

Claims (8)

1. a method for compressor reliability assessment, is characterized in that comprising the steps: a. Connect the test device, connect the balance valve (4) and expansion valve (5) in parallel to the inlet and outlet of the compressor (1), open the balance valve (4) and vacuumize the system; b. Add refrigerant, wait until the equilibrium pressure reaches 0.3-0.45MPa, close the balance valve (4), and start the compressor (1); c. Adjust the expansion valve (5) to make the suction pressure of the system reach 0.55-0.6MPa, and shut down the compressor (1) after the exhaust pressure reaches 1.5-1.7MPa; d. Open the balance valve (4) to balance the system pressure, then close the balance valve (4) to restart the compressor (1), and repeat step c; e. Open the shell and check the mechanical parts of the compressor (1). 2. A method for evaluating the reliability of a compressor according to claim 1, characterized in that: the inlet and outlet pipes of the compressor (1) are respectively provided with a suction pressure gauge (7) and a discharge pressure gauge ( 2). 3. A compressor reliability assessment method according to claim 1, characterized in that: in said step a, the system is evacuated to -0.12 to -0.08MPa. 4. A method for evaluating the reliability of a compressor according to claim 3, characterized in that: the degree of vacuum in said step a is measured by gauge pressure. 5. A compressor reliability evaluation method according to claim 1, characterized in that: in said step b, a refrigerant cylinder is used to add refrigerant, and the refrigerant is liquid R314a. 6. A method for evaluating the reliability of a compressor according to claim 1, characterized in that: said inlet and outlet pipes of the compressor (1) are respectively provided with a suction valve (6) and an exhaust valve (3 ). 7. The method for evaluating the reliability of a compressor according to claim 1, wherein the pressures in steps b and/or c are all gauge pressures. 8. A compressor reliability assessment method according to claim 1, characterized in that: step c needs to be repeated once or twice in step d.

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