DHX工艺丙烷回收(火用)经济分析

Exergy-economic analysis of DHX process for propane recovery

为降低采用直接换热(Direct Heat Exchange,DHX)工艺从天然气中进行丙烷回收时的运行成本,提高装置经济效益,以某天然气处理厂为例,利用Aspen HYSYS软件建模,对其DHX工艺进行了模拟,再采用常规㶲、高级㶲及㶲经济分析方法对DHX工艺进行分析。模拟发现,DHX工艺系统的总㶲损量和㶲效率分别为8998.23 kW和29.28%,其中膨胀机组及外输压缩机㶲损占比大,且可避免内源及外源㶲损成本过高,因此将其作为优化重点,并将改进方向放在参数优化上。基于优化策略,对主冷箱进行了参数敏感性分析。分析结果表明,在天然气处理量为1500×10^(4)m^(3)/d的情况下,当膨胀机组膨胀端出口压力保持在3550 kPa时,系统费用减少了43.76美元/h,经济效益十分显著。研究结果对DHX工艺参数的调节有指导意义。

In order to reduce the operating cost of propane recovery from natural gas in the DHX(Direct Heat Exchange)process,and improve the economic benefits of the process system,the propane recovery process of a natural gas processing plant was taken as an example whereby the DHX process was simulated by using Aspen HYSYS software.The process was then analysed using conventional exergy,advanced exergy and exergy economic analysis methods.From the analysis,it is found that the total exergy loss and exergy efficiency of the system are 8998.23 kW and 29.28%respectively.,The loss in the expansion unit and external compressor accounts for a large proportion of the exergy loss,and the cost of avoidable endogenous and exogenous exergy loss is relatively high.Hence it is the focus of optimization.,and the improvement direction is placed on parameter optimisation.Based on the optimization strategy,the parameter sensitivity analysis of the heat exchanger is carried out.The results show that in the case of natural gas processing capacity of 15×10^(6) m^(3)/d,when the outlet pressure of the expansion end is maintained at 3550 kPa,the system cost is reduced by 43.76$/h.The economic benefit is significant and the research results have strong guiding significance for the parameter adjustment of the propane recovery unit.