The Experimental Research And Numerical Simulation Of The Thermal Load Of CNG/Diesel Dual Fuel Engine

With the development of internal-combustion engine towards high speed and aggrandizement constantly, the problems of its heat transfer and thermal load become more and more outstanding. Then how to settle the thermal load problem of internal-combustion engine availably and improve the reliability and usage life of the heated parts of internal-combustion engine becomes more and more important and urgent. Because of the influence of thermal load, many malfunctions, such as abnormal wear of the heated parts of internal-combustion engine, corrosion and ablation of materials and destroy by thermal fatigue etc, often occurs. And it influents the power capability, economic capability and reliability of internal-combustion engine directly or indirectly. Accordingly, the research of heat conduction and thermal load is becoming an all-important project in the research of internal-combustion engine. Besides, due to shortage of the fuel oil and the increasing requirement to emission, the research and development of the alternative fuel engine has got people's much attention.In this paper the development and actuality of the research of the heat transfer and thermal load in the internal-combustion engine project are reviewed, then the thermal condition, thermal load and thermal load malfunction are defined and explained. Then the basic fundamental and method of the computation of thermal load of the heated parts of internal-combustion engine are elaborated, the deflective differential equation of heat conduction, basic equation and boundary condition of the theory of thermo elasticity and numerical computation by FEA are introduced.The method of the temperature measurement of the heated parts of diesel/CNG dual fuel engine is hardness tucks way in the paper. Through the measurement for the heated parts of fire chamber, whether the temperature is in the admit extent of the capability of the used material can be inspected. Then the law of heat flow and the distribution of the heat loss are estimated. In this paper the numerical simulations of the temperature field and the thermal deformation of the piston of 4112 diesel/CNGdual fuel engine are carried by ANSYS software.Through the experimental research and numerical simulation of the thermal load of 4112 diesel/CNG dual fuel engine at different fuel supply advance angle and in different diesel/CNG supply rate, the statuses of its thermal load are gotten, and the different statuses are analyzed, compared and evaluated. That will point out approach or find out the method for the reform of the thermal load, and provide the direction and the important reference for the optimization of fuel supply advance angle and diesel/CNG supply rate of diesel/CNG dual fuel engine in the future. On the other hand, in the design stage of diesel engine, the forecast for thermal load can be carried through the database, graphic base of the thermal load and the law and experience of heat transfer for the purpose of shortening the period of design, trial production and experiment.