涡轮增压天然气发动机电控系统进气模型研究
Intake Charge Model of Electronically Controlled Turbocharged Natural Gas Engine

针对天然气发动机普遍采用的进气充量标定方法精度和可移植性不高的问题,以一台潍柴WP10NG336涡轮增压火花点燃单点喷射全电控天然气发动机为研究对象,研究了基于物理模型的适合天然气发动机的进气充量模型。在平均值模型的假设基础上,采用折合气体流量描述进气过程,将进气过程流经缸内的气体细分为回流废气、扫气废气、倒流废气、始终驻留废气和新鲜折合气体,对涡轮增压器、节气门、进气管、排气管和气缸进行综合建模,并通过进气惯性对充量的影响来对模型进行简单修正。为验证模型的精确性,开展了针对WP10NG336天然气发动机的台架试验。试验结果表明,本文所提出的进气模型误差范围在4％以内,在占用较少计算资源的情况下能够准确地估计各种工作条件下发动机的实际稳态进气充量。
Aiming at the problem of poor accuracy and portability of normal intake charge calibrating method used in natural gas engine and taking a Weicai WP10NG336 turbocharged single？？point injection natural gas engine as the research object, an intake charge model suitable for natural gas engine was studied. Based on the mean model, the equivalent gas flow was used to describe the intake process. The gas flowing through the cylinders was divided into reversing flow exhaust gas, scavenging exhaust gas, backflow residual gas, consistently stayed residual gas and fresh equivalent gas. Synthetic modeling and analyses were conducted on the turbocharger, throttle valve, intake manifold, exhaust manifold and cylinders, and the model was verified in consideration of the influence of intake inertia. Experiments on the WP10NG336 turbocharged natural gas engine were conducted, and results showed that the error range of the intake model proposed in this paper is within 4％ and the air charge model is able to accurately estimate the actual air charge under different working conditions while occupying little computing resources