两级膨胀器性能仿真

针对单级膨胀器的效率低下等缺陷,提出两级膨胀器的结构形式,并对其进行热力学和动力学分析,建立了数学模型。根据两级系统模型进行计算机仿真,结果表明:两级膨胀器在进气高压的工况下,高压气体膨胀更加充分,并符合膨胀器高扭矩、低转速的性能要求。此外,还选取若干个控制参数,研究其对气动效率和气动功率的影响。在相同的设计时速下,不同的进气行程比和传动比相匹配,系统的气动效率基本相同,且低负载率有利于提高系统效率;第二缸尺寸对系统气动效率影响不大,但对功率具有较大影响,需要选择适宜的尺寸。

Performance Simulation of Two-stage Expansion

For single-stage expander inefficiencies and other defects, two-stage expansion device is proposed by the thermodynamic and kinetic analysis method, and a mathematical model is built. According to two-stage system model computer simulation results show that: two-stage expansion in the high pressure conditions, high-pressure gas is expanded more fully in accordance with the high-torque, low-speed performance requirements. In addition, a number of control parameters are selected to study their impact on aerodynamic efficiency and pneumatic power. Under the same design speed, adopting different intake stroke ratio and the transmission ratio, the aerodynamic efficiency of the system is basically the same and the low load rate will improve the efficiency of the system; the second cylinder size has little effect on the aerodynamic efficiency of the system, but it has influence on pneumatic power, the appropriate size should be selected.