Reasons for low suction pressure of compressor cold storage equipment
1. The liquid supply pipe, expansion valve or filter of the refrigeration system is blocked by dirt, or the opening is too small, the float valve fails, the system ammonia liquid circulation is small, the intermediate cooler liquid supply height difference is insufficient or the pipe diameter is too small, which will cause the compressor suction pressure to be too low.
2. Insufficient refrigerant filling or liquid supply in the refrigeration system, improper throttle valve adjustment will cause low suction pressure of the compression molding machine.
3. If the evaporator pipeline is too long or the design of the suction main pipe is improper for multiple compressors in parallel, the compressor suction pressure will be low.
4. The oil content of the Freon system that is easy to dissolve oil is too high, which reduces the suction pressure.
5. The evaporator in the warehouse is frosted thickly or the inner wall is oily, which increases the thermal resistance and reduces the suction pressure.
2. Hazards and specific reasons of too low suction pressure in refrigeration system
1. Hazards: The hazards caused by too low suction pressure in refrigeration system are basically the same as those caused by too high exhaust pressure;
2. The main reasons for too low suction pressure in refrigeration system are as follows:
a. The frost on the air cooler in the warehouse is too thick;
b. The motor or fan blades of the air cooler are damaged;
c. The system has a refrigerant leak;
What is the normal value of the air conditioning compressor pressure?
1. The normal high pressure should be 1.3-1.7MPa (13-17kg/cm2 or 190-250Lbf/in2); the normal low pressure should be between 0.15-0.25MPa (1.5-2.5kg/cm2 or 20-35Lbf/in2). If the low pressure is higher or lower than this range, it means that the expansion valve is not adjusted normally. If there is a problem with the compressor, it is not in this category.
2. To measure the high and low pressures of the air conditioning system, the engine should be running at idle speed, and the measurement should be based on the ambient temperature of 35℃.
3. When the engine increases the throttle, the measured low pressure should decrease with the engine speed. The faster the speed, the more (faster) the pressure drops. This indicates that the performance of the compressor is good, otherwise it indicates that the compressor is faulty.
4. The air-conditioning compressor plays the role of compressing and driving the refrigerant in the air-conditioning refrigerant circuit. The air-conditioning compressor is generally installed in the outdoor unit. The air-conditioning compressor extracts the refrigerant from the low-pressure area and sends it to the high-pressure area for cooling and condensation after compression. The heat is dissipated into the air through the heat sink, and the refrigerant also changes from gas to liquid, and the pressure increases.
5. The working circuit of the air-conditioning compressor is divided into an evaporation area (low-pressure area) and a condensation area (high-pressure area). The indoor and outdoor units of the air conditioner belong to the low-pressure or high-pressure area respectively (depending on the working status). The refrigerant then flows from the high-pressure area to the low-pressure area, and is sprayed into the evaporator through the capillary tube. The pressure drops suddenly, and the liquid refrigerant immediately becomes gaseous, absorbing a large amount of heat in the air through the heat sink. In this way, the air-conditioning compressor keeps working, constantly absorbing the heat at one end of the low-pressure area into the refrigerant and then sending it to the high-pressure area to dissipate into the air, thereby regulating the temperature.
Guangxi Cooler Refrigeration Equipment Co.,Ltd.
Email:karen@coolerfreezerunit.com
Tel/Whatsapp:+8613367611012
Post time: Jul-16-2024