Working Process Modeling and Performance Simulation of Half-Crank Internal Combustion Pump

Abstract

Half-Crank Internal Combustion Pump (HICP) is a new type agricultural power machine converting indicated work into pressure energy, whose crankshaft comprises only half a crank, reciprocating inertial forces of cylinders can entirely counteract each other, the structure is simple and compact, the route of energy transferring is shorter, the technologies based on are mature also. Considering the nonlinear factors including friction, coupling of fluid-solid-gas, etc., and the collaborative mechanism between many disciplines, the dynamic model of HICP is constructed to solve the transient movement and force. Facing the whole working process simulation of HICP, the stationary point iteration method through adjusting the output pressure to arrive at steady working state, is designed, so, the time course of every movement and force during one working cycle can be gotten for the analysis of power and economic performance. The evaluating index system of the performance of HICP was provided also. Through simulation, when throttle changes between 30%~100% and rotational speed changes between 900r/min~2300r/min, the output pressure and fuel consumption changed within 1.923Mpa~10.554Mpa and 220.0333g/(kW• h)~365.9479 g/(kW• h) respectively. The pressure is slightly influenced by rotational speed. Fuel consumption shows a middle concave shape and the best point is around the rotational speed of 1300r/min, and the fuel throttle of 70%. The nonlinear dynamic model and simulation method effectively realized the working process and performance simulation of HICP, of course, is suitable for many other machines also, and the simulation precision is decided by the boundary conditions.