Internal Combustion Engine Cylinder Heat Transfer Test System Development

The study of internal combustion engine heat transfer is directly related to the engine performance, reliability, economy and emission characteristics. The heat transfer in cylinder is an important part of the internal combustion engine heat transfer, and it is highly implications for research. During the internal combustion engine cylinder heat transfer testing process, due to the working environment of cylinder is very complex, it is difficult to control the working conditions of the internal combustion engine, and it is not conducive to study the influence of single variable. It cause considerable difficulty for the analysis of test result. This test system of internal combustion engine heat transfer in cylinder is designed by using simulation test ideology. The engine is operated in a motored condition by converter motor, the high-temperature gas is external supplied. By controlling the change of motor rotational speed and the temperature of gas independently, the influence of average piston linear velocity and gas temperature on heat transfer in cylinder can be studied.The following works have been completed in this thesis:1. Analysis of the advantages and disadvantages of the test method, completing the overall design of the cylinder heat transfer test system, The engine is operated in a motored condition by converter motor, the high-temperature gas is supplied by external burner. The piston linear velocity and gas temperature is separated as single variable.2. Design high temperature gas produce and supply systems, compressed air generated by the compressor pass into the gas tank, the tube divided into two branches from the gas tank exports The first branch head to the burner which producing high-temperature gas, the other branch as a secondary intake adjust the temperature of the gas. Design regulator tube mixing the two airstreams, while preventing pressure fluctuations of single-cylinder engine intermittent intake affect burner’s combustion stability, the design of high temperature gas produce and supply systems can applies to multiple engine cylinder heat transfer test.3. Design signal acquisition、processing and control subsystem, choose NI cDAQ test equipment to develop measurement and control system, use NI Lab VIEW software to complete the test system acquisition and control program development. Choose piezoelectric pressure sensor measuring cylinder gas pressure; choose the angle encoder to measure converter motor speed and crank angle; made K-type thermocouple measurements required temperature data.4. Integrate and debug the cylinder heat transfer test system, the test is completed by application of the developed test system. Verify the function of test system, and study the cylinder heat transfer situation under different engine revolution speeds, draw the relationship of linear velocity of piston and heat exchange between gas and combustion chamber wall.