The Influence of Residual Volume on Volumetric Efficiency of Plunger Pump

To raise the availability of the bar piston pump,we have studied the influences of residual volume and the gap of piston-cylinder pair on the efficiency of plunger pump.Through the theoretical analysis,we found that the reduction of residual volume could effectively improve the volumetric efficiency of plunger pump,but too smaller volume in the plunger chamber can make the plunger over-heated and have it killed.It can be improved by increasing the gap of the piston-cylinder pair.In combination with state balance and fluid mechanics,we derived the circumferential friction force equation,and to solve it,we used a digital simulation program.Simulations show that,with the plunger clearances increased,the circumferential friction force will also increase,thus reducing the mechanical efficiency of the pump.Therefore,an appropriate adjustment of residual volume is needed.