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降低油耗和减少 NO_x 排放量通常是矛盾的。为使这两者统一起来,可改变直喷式柴油机的进气涡流。因此,我们研制了涡流随发动机转速、负荷可转换到最佳值的装置。开始,我们探讨了决定涡流强弱的主要因素。在此基础上,进行了各种可变涡流进气道的稳流试验。最后,确定了用副进气道控制从进气门流向气缸的逆向涡流角动量是最好的方法。在发动机上使用这种可变涡流进气道研究了涡流和发动机各种性能之间的关系,试验结果如下:(1)不管发动机转速、负荷如何,NO_x、P_(max)和 dp/dθ总是随着涡流的减弱而降低。(2)高速时,燃油消耗率和排烟浓度随涡流减弱而降低,低速时则相反。(3)低速燃油消耗率在轻负荷时,与全负荷时的情况相反,涡流弱时才降低。综合以上的结果即可得到适当的涡流图。在实际发动机上使用传感器、执行器,同时安装了可变涡流进气道,结果,NO_x 排放量并未增加,但低速扭矩增大了,燃油消耗率降低了。
Reducing fuel consumption and reducing NOx emissions is often contradictory. In order to unify the two, it can change the direct injection diesel engine intake vortex. Therefore, we developed a device that eddy current can be switched to the optimal value with engine speed. Initially, we explored the main factors that determine eddy current strength. On this basis, a variety of variable vortex inlet steady flow test. Finally, it is determined that the counter-flow angular momentum from the intake port to the cylinder controlled by the sub-port is the best method. The relationship between eddy current and various performances of the engine was studied on the engine using this variable eddy inlet. The test results are as follows: (1) The total NO_x, P_ (max) and dp / dθ regardless of engine speed and load Is reduced as the eddy current weakens. (2) At high speed, the fuel consumption rate and exhaust smoke concentration decrease as the eddy current weakens, and vice versa at low speed. (3) Low-speed fuel consumption rate In the light load, contrary to the situation at full load, the eddy current is reduced only when it is weak. The above results can be obtained by the appropriate eddy current map. Sensors and actuators were used on the actual engine with a variable vortex inlet installed. As a result, NO_x emissions did not increase, but low-speed torque increased and fuel consumption was reduced.