Development Of The BL20L LNG Engine

With the continuously increase of the world economy, oil crisis has become a huge problem for human to confront. In addition, as the auto possession increasing, the environmental pollution caused by the emission of cars has brought more attention of public. Among the variety of alternative fuels used by cars, natural gas has become a better alternative fuel that can solve these problems because of the advantages such as abundant resources or a high degree of cleanliness. In the future for the development, there are a plenty of advantages by using the natural gas, and as a vehicle alternative fuel, it is regarded as a very promising cleaning vehicle fuel. The Liquefied Natural Gas Vehicle (LNGV), with the characters such as economical, safe and slight emission, has been a new generation of NGV. It also can make LNGV driving longer distance, and facilitating the application of LNGV in the long-distance driving. Therefore, it will be a new direction for developing the natural gas vehicles, and it is also an effective method to solve the oil crisis and the environmental problems.This article is based on the introduction of original BL2.0L gasoline engine, and through the designing and developing of the gas supply system, ignition system and electronic control system, the original machine has been transformed into an multi-point injection LNG engine of a single fuel. The electronic control system can precisely control the intake of the gas, the injection of LNG, the phases of the intake VVT, and the ignition timing. Thereby the engine will have good power performance and economy, and its emission reach the emission standard of Countryâ…£. In order to achieve the objectives of engine development, we did a matching and calibrating test of the LNG engine. According to the corresponding investigation target, the MAP of the jet pulse width of the natural gas, the MAP of the ignition timing, the MAP of the amount of intake air and the MAP of the phases of the intake VVT were calibrated and stored in ECU. And then the LNG engine is running with the results of the calibration.According to the results of the calibration which LNG engine performance, we can draw that the power performance and economy of LNG engine have reached the targets of developing. By comparing and analyzing the outside characteristic curve of LNG engine and the original gasoline engine, we can learn that the power performance of LNG engine has decline, because the natural gas has affect the charging efficiency of air by which the gaseous form entering the intake manifold. However, the economy of the LNG engine has improved, and the gas mixing the air well. We can get the conclusion that the LNG engine has a better economic of fuel. In addition, by studying the reliability of the LNG engine, the research shows:according to the results of the reliability test, the power, torque and consumption rate are less than 4%.The change of the oil gas rate and the cylinders pressure are inconspicuous, so they are all within acceptable limits.In this article, the power performance, economical and reliability of the LNG engine are all reaching the objectives of the development. They reflect the characteristics of the LNG engine and proof that LNGV has a better development potential.