Solution to the condensing pressure of the chiller refrigeration system

Solution to the condensing pressure of the chiller refrigeration system

1. The condenser of the chiller is dirty

Computer room chillers generally use air-cooled condensers, which are composed of multiple sets of coils, and fins are added to the coils to increase the heat transfer area on the air side. At the same time, fans are used to accelerate the flow of air to increase the transmission on the air side. Thermal effect. Due to the small distance between the fins and the continuous use of the chiller in the computer room for a long time, flying insects and dust stick to the condenser fins, so that the air cannot pass through the condenser in a large amount, and the thermal resistance increases, which affects the heat transfer effect and causes condensation The effect is reduced, the pressure on the high-pressure side is increased, and the cooling effect is reduced, while more power is consumed. For every increase of 1kg/cm2 of condensing pressure, the power consumption increases by 6-8%.

Countermeasures: According to the environment of the chiller, periodically flush the outside of the chiller according to the ash formation. The specific method is to flush the air-conditioning condenser from the inside to the outside with a water gun or compressed air to remove debris and dust attached to the condenser. , Verizon Communications in New York now flushes the outside of the computer room air conditioner twice a year to ensure good heat dissipation and save a lot of energy.

　　2. Improper condenser configuration

In order to save costs and maximize profits, some manufacturers deliberately configure a small condenser to reduce the cooling effect of the chiller. This situation should be avoided when the chiller is designed, but it sometimes happens, causing frequent high pressure in the chiller in summer. Warning, frequent flushing of the external unit of the chiller will not help, seriously increasing the workload of the maintenance personnel and the condenser must be replaced. For example, in the Zhuantang and new fan rooms in Hangzhou, due to the small condenser configuration and high-pressure failures at both ends of the three days in summer, maintenance personnel are exhausted and waste a lot of manpower and material resources. Now the Hangzhou Telecom branch has replaced the unreasonable condenser. This problem is solved very well.

　　 3. There is air inside the system

　　If the vacuum of the chiller is not enough, air will be mixed in when adding liquid accidentally. Air is harmful in the refrigeration system. It will affect the condensation and heat release of the refrigerating agent's steam, which will increase the working pressure of the condenser. For example, when the condensing temperature is 35 degrees, the corresponding condensing pressure is 12.5kg/cm2 gauge pressure. , But the actual pressure of the pressure gauge may be 14kg/cm2, this extra 1.5 kg/cm2 of air is occupied in the condenser (Dalton's law), due to the increase of the exhaust pressure, the exhaust temperature also increases, and the cooling capacity Reduce and increase power consumption, so the air in the high-voltage system must be removed. Countermeasure: Perform air venting operation. In the case of shutdown, vent the air from the exhaust port or the condenser plug for air venting.

　　4. Too much refrigerant injection will increase the condensing pressure. Since the excess refrigerant will occupy the area of the condenser, the condensing area is reduced and the condensing effect becomes worse.

Conclusion: Through the above methods, the chiller can be guaranteed to work in the best condition, which not only reduces the failure rate of the chiller, but also a single chiller can save 10-20% of the energy in summer. Therefore, strengthen the maintenance of the chiller. The cooling effect of the air conditioner, the life of the air conditioner, and especially the energy saving are of great significance.