CAJ | 학술논문

为了解决传统增压匹配方法不能保证所选涡轮增压器与柴油机最佳匹配的问题，以及内燃机是高度的非线性系统，难以使用具体的数学公式来表示某一参数与其他参数之间的相互关系，基于一款非道路用柴油机的设计开发需求，提出了利用参变量扫值进行增压匹配的方法，以GT-Power软件为载体建立相应的增压柴油机模型，通过对不同大小的压气机和涡轮进行参变量扫值计算，在满足柴油机设计指标与耐久性约束的条件下，综合选取了与柴油机匹配良好的涡轮增压器。为了折中增压之后表征机械负荷的最高气缸压力与表征热负荷的排气歧管温度，又通过模拟分析确定了合理的增压压力和燃烧始点。台架试验结果表明：选定的涡轮增压器与柴油机匹配良好，各项性能参数与排放指标均达到了设计要求，合理匹配增压压力和燃烧始点可有效平衡最高气缸压力与排气歧管温度之间的矛盾。参变量扫值方法代替了实际增压匹配的复杂调整过程，并为实际的标定工作提供了一定的借鉴指导。
위료해결전통증압필배방법불능보증소선와륜증압기여시유궤최가필배적문제，이급내연궤시고도적비선성계통，난이사용구체적수학공식래표시모일삼수여기타삼수지간적상호관계，기우일관비도로용시유궤적설계개발수구，제출료이용삼변량소치진행증압필배적방법，이GT-Power연건위재체건립상응적증압시유궤모형，통과대불동대소적압기궤화와륜진행삼변량소치계산，재만족시유궤설계지표여내구성약속적조건하，종합선취료여시유궤필배량호적와륜증압기。위료절중증압지후표정궤계부하적최고기항압력여표정열부하적배기기관온도，우통과모의분석학정료합리적증압압력화연소시점。태가시험결과표명：선정적와륜증압기여시유궤필배량호，각항성능삼수여배방지표균체도료설계요구，합리필배증압압력화연소시점가유효평형최고기항압력여배기기관온도지간적모순。삼변량소치방법대체료실제증압필배적복잡조정과정，병위실제적표정공작제공료일정적차감지도。
A certain number of turbochargers are usually selected according to calculation parameters to conduct the bench test with diesel engine and the best one among the several turbochargers will be chosen with the traditional turbocharger matching method. However, this method can’t guarantee that the selected turbocharger is the best choice. Because the internal combustion engine is a highly nonlinear system, it is difficult to use specific mathematical formula to represent a certain relationship between a parameter and other ones. Parametric sweeping to calculate objective functions to find optima is an optimization. It computes the objective function by directly sweeping the factors and then finds the optima by checking the sweeping results against the constraints. The parameter sweeping method is usually restricted to only one or two deign factors, because it is difficult to plot the parametric data of more than three factors. Meanwhile, the turbocharger matching just has two factors, i.e., compressor and turbine. Therefore, based on the design and development demand of a non-road diesel engine, a turbocharger matching method conducted by parametric sweeping was put forward, the corresponding turbocharged diesel engine model was developed according to the primarily selected turbocharger with GT-Power software as a carrier. In order to choose the best compressor and turbine, parametric sweeping study of normalized compressor mass multiplier and normalized turbine mass multiplier was conducted. The effects of compressors and turbines of different sizes on air-fuel ratio, brake specific fuel consumption, peak cylinder pressure and exhaust manifold temperature were analyzed. The final turbocharger having a good matching with diesel engine was selected under the conditions of the diesel engine design objective and durability constraints. However, the cylinder pressure and temperature will significantly increase when the internal combustion engine is equipped with a turbocharger, and both of the mechanical loading and thermal loading will increase, too. In order to weigh peak cylinder pressure (an indicator of mechanical loading) and exhaust manifold gas temperature (an indicator of thermal loading) after turbocharged, the parametric sweeping simulations of the boost pressure and start of combustion were also conducted. The two appropriate parameters were determined based on the simulation results under the durability constraints. The bench test showed that the selected turbocharger matched well with diesel engine, and the power capability, fuel economy, low-end torque and emissions targets have all reached the design requirements. The diesel engine durability constraints were also within the scope of the limit. Parametric sweeping study displayed the effects of compressors and turbines of different sizes, boost pressure and start of combustion on the diesel engine performance visually. It also can replace the complicated adjustment process of the real turbocharger matching and provide a reference guide for the actual calibration work. In addition, it can effectively balance the contradiction between the peak cylinder pressure and the exhaust manifold gas temperature by the calibration of the boost pressure and start of combustion reasonably.