Explosion-proof diesel engine has a strong adaptability to harsh environment, but also has strict requirements for oil injection characteristics. According to the theory of hydrodynamics, a physical model was built to test the capture rate under different spacing between nozzle hole and oil inlet. The relationship between injection temperature and pressure in injection chamber and injection characteristics of nozzle was obtained. When the second-order effect of piston reciprocating motion is neglected, the diffusive angle of the nozzle holes with vertical structure is smaller under the experimental parameters. It can be seen that the size of injection cross-section has little effect on the capture rate, and the reflux characteristic of the oil chamber is the key factor affecting the capture rate.
