中文摘要：

基于理论循环和校准后的GT-Power模型研究了燃烧放热率对车用发动机热效率、最高燃烧压力、压力升高率及能量分配的影响规律。理论循环研究表明热效率仅取决于加热时刻相对于上止点的角度，与上止点前后无关，即加热时刻所对应的热效率关于上止点具有对称性。GT-Power模拟研究表明：实际循环中由于传热、摩擦损失的增加使得放热率对应热效率沿上止点不对称，持续期越长、重心越偏离上止点不对称性越明显；对于HCCI燃烧模式，由于放热持续期很短、且靠近上止点，即使完全在上止点前燃烧其热效率也较高；均质、低温、稀燃燃烧模式，由于加热量直接决定缸内温度及传热量，其负荷拓展受到理论上的限制。

英文摘要：

The effects of heat release patterns on the indicated thermal efficiency, in-cylinder peak pres-sure, pressure rise rate and the energy loss fractions were investigated based on theoretical cycle analysis and GT-Power simulation. Theoretical cycle analysis shows that thermal efficiency is depended on the timing of heat release to the top dead center （TDC）. Simulation with GT-Power mode shows that, due to an increased heat transfer and friction loss, the thermal efficiency isn＇t symmetrical to TDC. Long heat release duration makes more asymmetrically in heat release pattern. The HCCI combustion mode still gives higher thermal efficiency even if combustion is completed before TDC due to shorter heat release duration and closing to the TDC. Load extension of homogenous charge, low temperature and lean mixture combustion mode is restricted by in-cylinder temperature, heat transfer fraction and peak pressure.