PRESSURE COUPLED CONTROL METHOD AND SYSTEM FOR DIFFUSION COMBUSTION OF NATURAL GAS ENGINE

The present invention relates to a pressure coupled control method and system for diffusion combustion of a natural gas engine, the method comprising: S11: detecting an operating condition of a natural gas engine; S12: an electronic control unit calculating a target diesel fuel pressure value flowing into a fuel rail of the natural gas engine according to the operating condition, and detecting an actual diesel fuel pressure value flowing into the fuel rail by means of a diesel pressure sensor in the fuel rail; S13: the electronic control unit calculating a target natural gas pressure value flowing into a gas rail of the natural gas engine according to the actual diesel fuel pressure value, and regulating a natural gas flowing into the gas rail by means of a signal of a gas rail pressure sensor in the gas rail; S14: after the target diesel fuel pressure value and the target natural gas pressure value are established, successively injecting high pressure diesel fuel and a high pressure natural gas into a gas cylinder; S15: detecting in real time a real-time operating condition of the natural gas engine, and promptly regulating the target diesel fuel pressure value and the target natural gas pressure value according to the real-time operating condition. The present invention improves diffusion combustion efficiency by means of the pressure coupled control of diesel fuel and natural gas.