压缩天然气卸气过程的非稳态分析

Non-steady state analysis of unload gas process of CNG

针对CNG卸气过程以往存在的节流系数取值单一、设备配置粗略、成本及能耗较高等问题,文章基于适当简化的实际气体状态方程—RK方程和节流过程的绝热等焓假设,通过对CNG卸气这一典型非稳态过程的研究,主要探索了平均节流系数的影响因素以及卸气过程中压力、质量流量和加热功率随时间的变化规律。结果表明:CNG卸气减压过程的平均节流系数与压降大小和初始温度密切相关,调压器配置换热器时,宜采用不同运行工况的节流系数;CNG卸气质量流量及加热功率随时间的变化呈现一定的相似性。

In view of the problems existing in the unload gas process of CNG like single throttle coeffi- cient value, rough equipment configuration and higher cost and energy consumption, and based on slightly simplified RK equation of real gas state equation and assumption of isenthalpic and adiabatic in throttling process, the paper analyzes the influencing factors of the average throttle coefficient and the variation with time of pressure and mass flow and heating power in the unload gas process. The re- suits show that pressure drop size and initial temperature are closely related to the average throttling coefficient and that different throttle coefficient of different operating conditions should be adopted with the configuration of the voltage regulator and heat exchanger. There is a certain similarity in the varia- tion with time of pressure and mass flow and heating power in the unload gas process.