Cylinder pressure control technology of natural gas-diesel dual-fuel engine based on pressure self-adaptive piston

In order to improve the economic performance and knock suppression of natural gas-diesel dual-fuel engine, the cylinder pressure control technology based on pressure self-adaptive piston (PSAP) was studied. The engine working process model was established in AVL-BOOST, the piston dynamics model was established in Matlab/Simulink, and the dual-model coupling was realized. The simulation results show that: PSAP can effectively control cylinder pressure, and can increase the maximum burst pressure to 8.12 MPa under 25% load conditions, and reduce the maximum burst pressure to 13.82 MPa under 100% load conditions; PSAP can reduce cyclic pressure fluctuation, compared with the original engine, the maximum reduction is 0.19 MPa; PSAP can reduce the fuel consumption rate under low load condition, and suppress knock by displacement of the piston head under high load condition.