Study On Impact Of Valve On Discharge Capacity In Reciprocating Compressor And Application

The valve has an important influence on discharge capacity in reciprocating compressor.The valve affects the compressor’s clearance volume,which affects the compressor’s volume coefficient and discharge capacity.When the valve is closed,the spring force per unit area on the valve plate affects the pressure coefficient and discharge capacity.The air tightness of the valve and whether the valve is closed late will affect the compressor’s leakage coefficient and discharge capacity.It is generally believed that the valve throttling will cause the power consumption and reduce the economy of compressor,but the influence of valve throttling effect on discharge capacity is not clear in reciprocating compressor.The paper expounds that the valve throttling effect will reduce the temperature coefficient and discharge capacity,the larger suction valve power consumption caused by throttling,the smaller the temperature coefficient and discharge capacity.In this paper,the simple calculation method of temperature coefficient is obtained to estimate the influence of the suction valve power consumption on discharge capacity in reciprocating compressor.The effects of different valve types on volume coefficient,pressure coefficient,leakage coefficient and temperature coefficient are analyzed.When the compressor is designed,the big valve is used instead of the multiple valve to increase the valve installation area;the valve with a larger area utilization coefficient can increase the effective flow area of the valve.When designing the compressor valve,it should be ensured that the valve opens and closes timely and has a long full opening period.Through the investigation in the field of coal chemical industry,it is found that the actual discharge capacity is lower than design in compressor,resulting in low production capacity.It shows that this is mainly caused by the small effective flow area and large power consumption of the valve.In addition,as the feed gas flowing through the compressor contains more dust,tar and other impurities,the valve is easy to block.In order to solve this problem,the paper proposes the following measures:（1）Change the structure of the valve to improve the air tightness and anti-blocking performance;（2）Increase the valve lift to improve the valve effective flow area;（3）Match the spring force of the valve reasonably to ensure that the valve has a good movement law.In view of the problem that the discharge capacity of 6MD32（4）B-256/54 and S6M50（X）-SM-333/260 N₂/H₂compressor is lower than designed,the measures proposed above were adopted to transform the valve in compressor.After the transformation,the discharge capacity of the 6MD32（4）B-256/54 N₂/H₂compressor increased by 4.4%,and the discharge capacity of the S6M50（X）-SM-333/260 N₂/H₂compressor increased by 8.6%.