Reasons for high exhaust temperature of chiller

Reasons for high exhaust temperature of chiller

The exhaust temperature of the compressor in the chiller unit determines whether the equipment can operate stably and efficiently. The compressor is prone to the problem of high exhaust temperature. Once this situation occurs, it is easy to cause the pressure and temperature of the chiller to rise, the load to be too high, and the working efficiency and cooling capacity of the chiller compressor to be reduced. It can also lead to various other problems. So what is the reason for the high exhaust temperature of the chiller? Below, the Jimes Refrigeration editor will provide a detailed introduction.

1. Compression ratio too high

The exhaust temperature is greatly affected by the compression ratio, and the higher the compression ratio, the higher the exhaust temperature. Reducing the compression ratio can significantly lower the exhaust temperature, including increasing the intake pressure and reducing the exhaust pressure.

The suction pressure is determined by the evaporation pressure and the resistance of the suction pipeline. Raising the evaporation temperature can effectively increase the suction pressure, rapidly reduce the compression ratio, and thus lower the exhaust temperature. Reducing the resistance of the return air pipeline can also increase the return air pressure. Specific methods include timely replacement of dirty and clogged return air filters, and minimizing the length of the evaporator pipe and return air pipeline as much as possible.

In addition, insufficient refrigerant is also a factor contributing to low suction pressure. After refrigerant leakage, it should be replenished in a timely manner.

The main reason for high exhaust pressure is high condensation pressure. Insufficient heat dissipation area, fouling, insufficient cooling air or water volume, and high cooling water or air temperature can all lead to high condensation pressure in the condenser. Choosing the appropriate condensation area and maintaining sufficient cooling medium flow rate are very important.

2. High return air temperature

The temperature of the return air is relative to the evaporation temperature. To prevent liquid reflux, the return air pipeline generally requires a superheat of 20 ° C. If the insulation of the return air pipeline is not good, the degree of superheat will far exceed 20 ° C.

The higher the return air temperature, the higher the cylinder intake and exhaust temperatures. For every 1 ° C increase in return air temperature, the exhaust temperature will increase by 1-1.3 ° C.

3. Motor heating

For the return air cooling refrigeration compressor, the snow vapor is heated by the motor when it flows through the motor chamber, and the cylinder suction temperature is once again increased. The heat generation of a motor is influenced by power and efficiency, while the power consumption is closely related to displacement, volumetric efficiency, operating conditions, frictional resistance, and other factors.

The temperature rise range of the refrigerant in the motor chamber of the return air cooling type semi sealed compressor is approximately between 15~45 ° C. In air-cooled compressors, the refrigeration system does not pass through the winding, so there is no problem of motor heating.

That's all for the reason why the exhaust temperature of the chiller is too high. We need to limit the exhaust temperature of the dedicated refrigeration compressor for chillers in order to better promote the development of the industry.