1.
油电混合车汽油发动机燃烧室的结构如图a,汽油机工作过程中在一个冲程内燃烧室内气体的
![](https://math.21cnjy.com/MathMLToImage?mml=%3Cmath+xmlns%3D%22http%3A%2F%2Fwww.w3.org%2F1998%2FMath%2FMathML%22%3E%3Cmi%3Ep%3C%2Fmi%3E%3Cmo%3E%E2%88%92%3C%2Fmo%3E%3Cmi%3EV%3C%2Fmi%3E%3C%2Fmath%3E)
曲线如图b所示,其中
B→
C和
D→
A为两个绝热过程。燃烧室内的气体可看做理想气体。一定质量的油气混合气体进入燃烧室,初始状态
A点处混合气体的温度为
![](https://math.21cnjy.com/MathMLToImage?mml=%3Cmath+xmlns%3D%22http%3A%2F%2Fwww.w3.org%2F1998%2FMath%2FMathML%22%3E%3Cmsub%3E%3Cmrow%3E%3Cmi%3ET%3C%2Fmi%3E%3C%2Fmrow%3E%3Cmrow%3E%3Cmn%3E1%3C%2Fmn%3E%3C%2Fmrow%3E%3C%2Fmsub%3E%3Cmo%3E%3D%3C%2Fmo%3E%3Cmn%3E3%3C%2Fmn%3E%3Cmn%3E0%3C%2Fmn%3E%3Cmn%3E0%3C%2Fmn%3E%3Cmtext%3EK%3C%2Fmtext%3E%3C%2Fmath%3E)
, 压强约为
![](https://math.21cnjy.com/MathMLToImage?mml=%3Cmath+xmlns%3D%22http%3A%2F%2Fwww.w3.org%2F1998%2FMath%2FMathML%22%3E%3Cmsub%3E%3Cmrow%3E%3Cmi%3EP%3C%2Fmi%3E%3C%2Fmrow%3E%3Cmrow%3E%3Cmn%3E1%3C%2Fmn%3E%3C%2Fmrow%3E%3C%2Fmsub%3E%3Cmo%3E%3D%3C%2Fmo%3E%3Cmn%3E1%3C%2Fmn%3E%3Cmn%3E0%3C%2Fmn%3E%3Cmn%3E0%3C%2Fmn%3E%3Cmtext%3Ek%3C%2Fmtext%3E%3Cmtext%3EP%3C%2Fmtext%3E%3Cmtext%3Ea%3C%2Fmtext%3E%3C%2Fmath%3E)
。火花塞点火瞬间,燃料燃烧使得燃烧室内的压强迅速增大到
![](https://math.21cnjy.com/MathMLToImage?mml=%3Cmath+xmlns%3D%22http%3A%2F%2Fwww.w3.org%2F1998%2FMath%2FMathML%22%3E%3Cmsub%3E%3Cmrow%3E%3Cmi%3EP%3C%2Fmi%3E%3C%2Fmrow%3E%3Cmrow%3E%3Cmn%3E2%3C%2Fmn%3E%3C%2Fmrow%3E%3C%2Fmsub%3E%3Cmo%3E%3D%3C%2Fmo%3E%3Cmn%3E3%3C%2Fmn%3E%3Cmn%3E0%3C%2Fmn%3E%3Cmn%3E0%3C%2Fmn%3E%3Cmtext%3Ek%3C%2Fmtext%3E%3Cmtext%3EP%3C%2Fmtext%3E%3Cmtext%3Ea%3C%2Fmtext%3E%3C%2Fmath%3E)
, 然后,活塞被推动向下移动,在经历
B→
C的绝热膨胀过程中,由于气体对外做功驱动汽车前进,使得气缸内温度降低了300K,膨胀结束到达状态
C时,燃烧室内压强降低到
![](https://math.21cnjy.com/MathMLToImage?mml=%3Cmath+xmlns%3D%22http%3A%2F%2Fwww.w3.org%2F1998%2FMath%2FMathML%22%3E%3Cmn%3E1%3C%2Fmn%3E%3Cmn%3E2%3C%2Fmn%3E%3Cmn%3E5%3C%2Fmn%3E%3Cmtext%3Ek%3C%2Fmtext%3E%3Cmtext%3EP%3C%2Fmtext%3E%3Cmtext%3Ea%3C%2Fmtext%3E%3C%2Fmath%3E)
, 求:
![](http://tikupic.21cnjy.com/2024/06/19/bb/ad/bbad9b693e2afb76ef13cdccdd1ef22c.png)