为在点燃式发动机上利用醇类混合燃料实现减碳节能的目标,基于 LJ4K18QS 发动机建模,利用醇类混合燃料对运行参数开展优化研究,揭示了空燃比及点火提前角
对发动机动力性、经济性和排放特性的影响规律。 结果表明:在负荷特性下,随着空燃比的增加,发动机扭矩和 NO_x排放先增大后减小,发动机燃油消耗率先减小后增大,CO排放逐渐减少,HC 排放逐渐增大;随着点火提前角的减小,发动机的扭矩先增大后减小,燃油消耗率和 CO 排放先减小后增大,NO_x 排放逐渐减小,HC 排放逐渐增大;同时,得到了发动机在不同负荷下的最佳空燃比和最佳点火提前角,可为后续研究提供一定的理论参考。

In  ord er to a chieve t he goal  of re duci ng car bon and saving e nergy by u sing alcoho l blende d fuel on s park ignition engine, bas ed o n LJ4 K1 8QS eng ine modeling, the alcohol ble nded fuel was us ed to op timiz e the operati ng param eters,  an d the i nfluence of air-fue l rat io and ig nition advance angle on engine power, economy and emission characteristics were reve aled . The re sult s show  that un der loa d chara cteri stics, with the increase of air -fuel rati o, engine torque and NOx emission s increase f irstly and then decrea se, e ngine fuel con- sumpt ion decrea ses and then inc reases, CO emissio ns de- crease gradually and H C emission s in crease graduall y. As the ignitio n ad vanc e angle dec reas es, t he engine tor que incre ases firstly and then de creases , the fuel consumpti on rate and CO emission s decrease firs tly a nd then i ncrease, NOx emissi ons dec rease gradu ally and HC emissio ns in crea se gradu ally. At the s am e ti me, the optimu m air-fue l ratio and ignition a dvance ang le of the en gine under different l oad s are obtain ed, which can provide the theo retical refer ence for subsequent research.