The core of a small cooling system is the compressor, which is developed to pump cool refrigerant vapor from the evaporator into the condenser to accomplish the cooling effect. Since the compressor plays such an important role in the system, it needs to be properly maintained and requires periodic inspection and testing to keep it in good operation.
As a vendor offering a lineup of mini dc compressors and compact refrigeration systems, MOIR is a good believer that product quality, functionality, and after-sales is the key to success in our micro cooling industry. We are big on user experience. In doing so, all of the units shipped are undergone strict inspection through our Quality Process Management, to ensure they are beyond customers’ expectations. While like many other equipment, the problems of the refrigeration system cannot be guaranteed avoidance due to various factors.
So it is necessary to determine the common failure of the systems and maintain it in time.
In this article, we sort up 10 common problem analyses for refrigeration failure and provide our solutions for the problems based on our know-how in this industry for your consideration.
Let’s dive right in.
1 Refrigerant Leakage
[Fault analysis]
In miniature refrigeration systems, the refrigerant leakage will cause insufficient cooling capacity, lower the suction and discharge pressure, and lead to an unexpected intermittent and lounder squeaking air flow sound. Besides, the evaporator won’t hang frost or only hangs a small amount of frost float. Even enlarging the expansion valve hole, the suction pressure still cannot change significantly.
After the shutdown of the operation, the equilibrium pressure in the small cooling system is generally lower than the saturation pressure corresponding to the same ambient temperature.
[Troubleshooting]
If the refrigeration system occurred refrigerant leakage, do not rush to fill the system with refrigerant. The first thing should immediately look over and find out where the leakage takes place and fix it. Then fill the refrigerant to the right level after the maintenance.
2 Excessive Refrigerant Refilled
[Fault analysis]
After the maintenance of the compact cooling system, the refrigerant is refilled over the standard level which takes up a certain room of the condenser. This will reduce the area for heat dissipation which decreases refrigeration efficiency. As a result, it caused the suction and discharged pressure to be higher than the standard pressure value, the evaporator frost is not solid and slow cooling.
[Troubleshooting]
According to the operation process, the excess refrigerant must be released at the high-pressure end after the shutdown for a few minutes, and the residual air in the small cooling system can also be released simultaneously.
3 Air in the Refrigeration System
[Fault analysis]
Air in the micro refrigeration system will reduce the refrigeration efficiency. The prominent phenomenon is that the suction and discharge pressure increase (but the discharge pressure has not exceeded the rated value). And the temperature from the miniature compressor outlet to the condenser inlet is significantly increased. Because of the extra air in the micro cooling system, the discharge pressure and temperature are increased.
[Troubleshooting]
The air in the system can be released by several times in a low from the high-pressure end ( condenser side ) after the shutdown for a few minutes. And a certain refrigerant can be charged appropriately according to the actual situation.
4 Low Compressor Efficiency
[Fault analysis]
The low efficiency of the miniature refrigeration compressor means that under constant working conditions, the actual displacement decreases, leading to a corresponding cooling capacity reduction.
This phenomenon often occurs in the mini compressors that have been used for a long time. The large wear and tear, and the large fitting clearance between the components lead to a decrease in the sealing performance of the air-tight valve, resulting in a decrease in the actual displacement.
[Troubleshooting]
Check whether the cylinder head paper gasket is broken down and causing leakage, and replace it if any.
Check whether the high and low-pressure discharge valve is loosely closed, and replace it if necessary.
Check the clearance gap between the piston and cylinder, and replace it if the clearance is too large.
5 Too Thick Frost on Evaporator Surface
[Fault analysis]
The evaporator used for a long time should be defrosted regularly. If it is not defrosted, the frost on the evaporator pipe will build up thicker and thicker. When the pipeline is wrapped entirely by the transparent ice.
It will seriously affect the heat transfer and cause the temperature in space to fall below the required range.
[Troubleshooting]
Stop the defrosting and use airflow or fans to speed up the circulation, shortening the defrosting time.
6 Residual Oil in the Evaporator Pipeline
[Fault analysis]
During the refrigeration cycle, some refrigerated oil remains in the evaporator pipeline. After a long period of use, when there is more residual oil in the evaporator, it will seriously affect its heat transfer effect and cause poor refrigeration.
[Troubleshooting]
Clear the refrigeration oil in the evaporator. Remove the evaporator, blow it out and then dry it. If it is not easy to disassemble, a mini rotary compressor can be used to pump air and blow dirt out from the evaporator inlet.
7 The Refrigeration System Not Runs Smoothly
【 Fault analysis 】
Because the microclimate cooling system is not cleaned thoroughly yet, after a certain period of use, the dirt gradually accumulated in the filter, and some meshes are blocked, resulting in the reduction of refrigerant flow and affecting the refrigeration effect.
In the micro cooling system, the filter at the inlet of the compressor is also slightly blocked.
[Troubleshooting]
Remove the micro-blocking components, clean and dry them, and install them back.
8 Filter Blockage
[Fault analysis]
The desiccant has been used for a long time and becomes a paste that seals the filter, or the dirt gradually buildups in the filter that causes blockage.
[Troubleshooting]
Remove the filter, clean and dry it, replace it with a new desiccant, and put it back into the system.
9 Improper Orientation and Positioning
[Fault analysis]
The orientation and position of a compressor can affect the flow of lubricant. Moir’s mini-size compressor operates properly when it is oriented within ±35° of vertically. Some mobile or portable refrigeration units such as refrigerators are not always oriented vertically.
If the mini-size compressor’s position is more than 35° from vertical, oil flow will be affected and the first sign of this is a decrease in cooling capacity.
[Troubleshooting]
Position the vapor compression refrigeration units vertically as much as possible. If they are permanently operated in extreme orientations, their life will be shortened.
10 Poor Heat Dissipation of Condenser
[Fault analysis]
If the condenser does not dissipate heat well, it will cause low refrigeration capacity or even no refrigeration.
[Troubleshooting]
Clean the condenser, and pay attention to cleaning the dirt inside the fin. And avoid obstacles at the outlet of the condenser. Also, clean the scale in the condenser.
In an era full of small cooling solution providers, reputation and trust have to be earned. So our commitment does not end with the device’s delivery. We are available online at any time for any technical support and solution inquiry. Feel free to drop us a message or email us at info@moircooling.
