A Fundamental Investigation On Working Processes Of I.C.Engines On Highland

While running at high altitude regions, an internal-combustion engine has its performance parameters decline markedly. It is difficult to ensure the engine can satisfy the demands at high altitude regions. Whether in our country or oversea, presently adopted correctional power and fuel consumption formulae are only applicable to the regions under altitude of 1000 meters, which can not express veritably the engines' performance when they are running at plateau. However, according to openly reports, systemically and embedded researches aim at engine running-process at various altitudes of plateau are few , thus affects the researches,designs and developments directly. Base on summarizations and analysis to the results of domestic and overseas researches to engine running process at different altitude regions, this paper develops a set of cyber-engine atmosphere-simulated integrated testing system. Correspondingly, it also develops the engines' performance parameters real-time-process-and-analyze software. It systemically test and study the influence and relationship of the atmospheric pressure to natural-inspiration diesel engine,gasoline engine,turbo-charged diesel engine and LPG/diesel double-fuel engine performance parameters and burning process under various altitudes, finally it obtains some new cognition and results. The results of the experiments show that the diesel engines' optimal pre-angle to provide fuel and the gasoline engines' optimal pre-angle to ignite won't change a lot with the increasing of the altitudes; Under the same condition of superfluous air coefficient, the carbon smog emission decreases; The diesel engine effectual fuel consumption rate and the correctional power coefficient attained by using coordinative superfluous air coefficient, augment with the decreasing of the superfluous air coefficient; With the heightening of the altitude, the turbo supercharger and the diesel associated running curves approach blow vibration borderline, and air compressor's efficiency comes down; In high altitude regions, adopting turbo charge and LPG/diesel double fuel engines will advantage the restoration of the engine's dynamic performance. The results of the experiments also show that, under different atmospheric pressure, the universal characteristic curves of the gasoline engine differ a great deal, under low atmospheric pressure, the universal characteristic curves'most economical fuel consumption region and corresponding effectual power region of gasoline engine get excursion adown markedly, and geometric proportion fuel consumption region narrows obviously. The economical fuel consumption ratio of the middle and low charge points, which the gasoline engines adapt to, has its effectual power minis. The results of study in this paper offer a theoretical foundation to the engine designs and ameliorations under different altitudes. At the same time, it offer experiment references to farther emendation of atmosphere correction standard.