CAJ | 학술논문

电控喷油器作为高压共轨喷油系统关键部件工作过程中涉及机、电、液多物理场耦合，为预测不同工况下系统喷油量特性，揭示系统多物理场耦合特性机理，该文考虑可变液容及燃油物性等对系统动态喷射特性的影响，运用键合图理论建立了共轨式喷油器各主要组成部件数值模型，得到了系统状态方程，通过对系统状态方程组数值求解计算，得到了不同工况下系统喷油量。建立了高压共轨喷油系统喷油量测试试验台，比较了轨压分别为80、100和120 MPa不同控制脉宽下系统喷油量测量结果与键合图数值模型计算值。结果表明计算结果与测量值最大相对误差为4%，因此基于键合图理论建立的共轨式喷油器数值模型可较好地预测系统喷油量特性。该研究对高压共轨喷油系统多物理场建模及系统喷射性能数值计算提供了参考。
전공분유기작위고압공궤분유계통관건부건공작과정중섭급궤、전、액다물리장우합，위예측불동공황하계통분유량특성，게시계통다물리장우합특성궤리，해문고필가변액용급연유물성등대계통동태분사특성적영향，운용건합도이론건립료공궤식분유기각주요조성부건수치모형，득도료계통상태방정，통과대계통상태방정조수치구해계산，득도료불동공황하계통분유량。건립료고압공궤분유계통분유량측시시험태，비교료궤압분별위80、100화120 MPa불동공제맥관하계통분유량측량결과여건합도수치모형계산치。결과표명계산결과여측량치최대상대오차위4%，인차기우건합도이론건립적공궤식분유기수치모형가교호지예측계통분유량특성。해연구대고압공궤분유계통다물리장건모급계통분사성능수치계산제공료삼고。
In order to comply with increasingly strict emission regulations and energy-saving means, it is necessary to reduce emissions and improve fuel economy and a new generation of fuel injection system has to be developed. The introduction of high pressure common rail fuel injection system certainly plays an essential role in achieving the current performance of diesel engines. As the critical component of high pressure common rail fuel injection system, electronic controlled injector involves the multi-physical fields coupled together including mechanical field, electrical field and hydraulic field during the working process. The equations of the traditional fluid dynamics modeling method are complicated. Moreover, the accuracy of solution for the system state equations increases with the complex of the numerical solution method. Power bond graph is a system dynamic graphical modeling method. It can systematically describe the composition, the transformation of the power flow and the logical relationship between variables in the system. In addition, the basic physical characteristics of the system and the relations of energy conversion and conservation also can be represented using the power bond graph method. In order to predict the fuel injection quantity characteristics of the high pressure common rail fuel injection system under different working conditions, and reveal the multi-physical fields coupling characteristic mechanism of the system, a bond graph numerical model of common rail injector is proposed based on the composition and the operating principle of the injector in this paper. The fuel physical properties and variable liquid capacitance which have influence on the dynamic injection characteristics of the system have been taken into consideration. The common rail injector bond graph model includes the main components such as high pressure fuel pipeline, high pressure fuel pipeline joint, pipeline between inlet of the injector and nozzle volume, nozzle volume, pipeline between nozzle volume and needle chamber, nozzle, needle moving parts, control chamber and solenoid valve. The state equations are derived based on the bond graph model of the common rail injector, and the equations are numerically solved by Matlab programming. Fuel injection quantity of the system at different common rail pressure and different control pulse width is obtained. The test bench of high pressure common rail fuel injection system is established in order to validate the accuracy of the developed bond graph numerical model. The experimental measured fuel injection quantities of the system and the calculation values of the bond graph numerical model are compared at common rail pressure of 80, 100 and 120 MPa and control pulse width of 800, 1 000, 1 200, 1 400 and 1 600μs respectively. It can be concluded that the developed bond graph numerical model of common rail injector for high pressure common rail fuel injection system has an acceptable calculation precision. The numerical model of common rail injector based on the power bond graph method can be used to predict the fuel injection quantity characteristics of the fuel injection system, and the bond graph method is an effective modeling tool for system dynamic numerical calculation. The results have a significant theoretical guidance for the multi-physical fields modeling of high pressure common rail fuel injection system and the numerical calculation of fuel injection characteristics of the system.