柴油机两相工质动力循环研究

Investigation on 2-phases Working Fluid Thermal Cycle for Diesel Engine

摘要:

提出了一种柴油机两相工质动力循环，该循环由混合加热循环和郎肯循环耦合而成。对两相工质动力循环进行了热力学分析，推导出其性能指标的计算公式，探讨采用两相工质动力循环提高柴油机功率密度的可行性。并以水为例，研究了相变工质的喷入参数和工质物性对循环性能的影响规律。研究表明缸内喷入液态工质可降低热负荷，与传统柴油机循环相比，在相同最高压力和最高温度条件下，两相工质动力循环的循环热效率降低，循环输出功增加。在每循环中喷入与燃油同质量的水后，循环的热效率下降了5.79%，输出功提高了6.36%。

Abstract:

A new thermal cycle called 2-phase working fluid thermal cycle for diesel engine was proposed, which consists of the dual cycle and Rankin cycle. The noble cycle was analyzed by thermodynamic method and the forums to calculate performance indexes were deduced. Take water as the phase-changing fluid for example, the influence rules between injection parameters and cycle performance were studied. The result demonstrates that the injection of water could alleviate heat load and enhance the power of engine, while the efficiency would be decreased compared with the traditional dual cycle. When the injection mass of water and fuel are equal at one cycle, the efficiency drops by 5.79% and the power rises by 6.36%.