Study On Exhaust Gas Heat Regulation Of Diesel/CNG Dual Fuel Engine And Flow Field Numerical Simulation

The research of CNG Engine has been a important progress in engine technologynowadays, a disquisitive issue on the engine industry within the country and abroadthese years.Diesel/CNG Dual Fuel Engine ignited by diesel is among these enginetechnologies, which is attached great importance by the scientists with its virtue ofconvenient refit, economical oil-consumption, flexible fuel-used, high efficiencyheating and good performance of exhausting gas. Refitting the Diesel engine toDiesel/CNG Dual Fuel Engine, is of great significance in optimizing energy sourcesstructure, minimizing the pollution of diesel exhausting gas and developing thecontinuable tactic.In this assay, firstly I analyze the combustion characteristic of diesel enginemixed-combusting CNG, and then establish a Two-dimensional model of Diesel/CNGDual Fuel Engine combusting process. The combusting process of Diesel/CNG DualFuel Engine has the two-tier characteristic of pre-mixed combustion and diffusiblecombustion, which makes it exhaust gas well. However, the temperature ofDiesel/CNG Dual Fuel Engine exhausting gas would be degressive and the degressivedegree is direct proportion with the diesel/CNG supply rate, due to the mixed-gas'thermal value of CNG and air is lower than the mixed-gas' thermal value of dieseland air.Diesel/CNG Dual Fuel Engine refitted from the 2135 diesel engine, its thermalvalue of exhausting gas is taken into researching experiment. After that, scientists getthe mathematics model between exhausting gas heating and the rotation, load, diesel/CNG supply rate, which provides academic evidence of utilizing the exhausting gasheating. After the analyzing of the experiment result, scientists get the conclusions:exhausting gas heating is direct proportion with the load and rotation, inverseproportion with diesel/CNG supply rate.In the assay, it introduces the development and actuality of diathermanousheating load research in internal-combustion engine, simulating the process ofinternal-combustion engine combusting with the value, defining and narrating Computational Fluid Dynamics. Following, expounding the essential priciples andmathods to solve thermal distributing of the gas engine exhausting gas flow field,introducing essential priciples of the deflective differential equation of heatconduction,basic quation of Boudary theomory and the method of confirm theboundary condition of the flow field and finite element mothods.To measure the thermal values of exhausting flow field through thermocoupleand hardness tucks, take the temperature values measured as the essential data, get theboundary term of exhausting gas through calculating and desposing, use finiteelement sofewares as the tool of numerical simulation, peolple numerically simulatethe the thermal field, compressive field and velocity field on the 2135 Diesel/CNGDual Fuel Engine's exhausting gas. Finally, they get the thermal distributing in thevent-pipe of the Diesel/ CNG Dual Fuel Engine in nomal conditon, supplingacademic evidence of how to use the exhausting gas of Diesel/ CNG Dual FuelEngine rationally.