Simulation Of Turbocharged Diesel Engine Operating Under High Back Pressure Environment

Nowadays, as the development of technology, people are paying moreattention to exploring special area like the sea, therefore, diesel enginesbeing able to operate in high back pressure environment are needed. Thepaper studied the performance of turbocharged diesel engine under highback pressure environments.The fundamental principles and the working process of high-pressureair starting for the high back pressure diesel engine is comprehensivelydemonstrated. A simulation model is built in order to study the influence ofback pressure, the diameter of high pressure air pipe, the pressure of gasvessel, the temperature of lubricating oil and the starting position ofcrankshaft on the engine performance during starting process.Study on the flooding phenomenon in the tail exhaust pipe ofunderwater engine is conducted. A physic model is built to descript thisphenomenon. Through this model, the minimum exhaust gas velocitypreventing the water flooding is calculated.A simulation model of a high back pressure engine is built and testedfor the study of the influence of back pressure on the engine performance.Under the circumstance of high back pressure, the influence ofturbocharging system, the valve timing, the compression ratio and exhaustpipe system is also studied. Operation points with different structureparameters of post exhaust system are simulated to study their effect onengine steady and transient performance in changing back pressureconditions.Research on the adaptability of normal turbocharged diesel engine to high back pressure conditions is conducted. Two improvement methods areproposed to enhance the adaptability of engine for different back pressureconditions...