Study On The Performance Improvement Of High Power Gas Engine

This paper mainly focus on 12V190 natural gas engine and generated the theoretical calculation of the main systems (turbo charging, cooling, intake, exhaust, air distribution, etc.) by analyzing the worldwide market requirements, R&D application status and the key technological characteristics of large power gas engine, then predicted and verified the performance index of the whole gas engine by the simulation and laboratory testing. An effective technical approach, which was tested and verified by the bench-scale test, was proposed to improve the power and performance of the whole engine, by the optimal matching of the 12V190 main systems, the preliminary analysis of the whole engine simulation, and the estimation and evaluation of the engine performance like maximum continuous power and thermal efficiency.In order to achieve the desired objective of high-power and high-performance and to meet the higher emission requirement, a main technical approach and a feasible technical solution were proposed, and the main research work of this paper is as follows:1) After a matching recalculation of the turbocharger, picked a new turbocharger with higher quality from a better company to match. The new turbocharger should satisfy the high power and performance requirements of engine, and should achieve the highest comprehensive efficiency as well.2) With a new matched intercooler, secondary deep cooled the pressurized gas by the new secondary cooling technology, which is, the pressurized mixed gas was primary cooled by the high-temperature cooling water and be further cooled by the low cooling water. By this way, the temperature of the mixed gas can be reduced effectively, the benefits of which are:increasing the amount of intake air, enlarging the power, avoiding the detonation, and reducing the emission of nitrogen oxides.3) Applied the optimized layout of the intake and exhaust system, which could meet the requirements of the operation condition of the power unit and obtained the compactness and beauty of the whole engine.The optimum parameter of the intake structure were obtained by its calculation and analysis, and the optimum parameter of the exhaust structure were obtained by the calculation and estimation of the exhaust branch pipe, the exhaust ejection angle, the exhaust ejection shrink hole diameter and the exhaust main pipe.4) The parameter of the valve timing were recalculated and the intake and exhaust cam was redesigned by using GT-VTRAIN to match the upgraded gas engine, which could improve the fullness coefficient of the intake and exhaust valve and further improve the inflation efficiency of the engine.5) The whole optimized engine was modeled and simulated with the simulation calculation software GT-POWER, which could predict and validate whether the performance index could meet the design requirements and the technical proposal could be reasonable and correct.6) The first prototype performance test - the prototype trail-manufacture, running-up test, performance test (such as different compression ratio test, different spark plug test, the optimum ignition advance angle test, a sudden load test, booster matching test) - was made to examine whether the engine power and the performance index could meet the design requirements and the technical proposal of the main system could be reasonable and correct.The research and analysis work of the main system of 12V190 nature gas engine, like turbo charging system, secondary cooling system, intake and exhaust system, gas distribution system, has been done in this paper, which provides certain design and experimental foundations for the power and performance improvement and the new produce development of the multi cylinder high power gas engine.