天然气分输站压力能利用方式经济性分析

天然气分输站压力能利用方式多样，需根据分输站条件选择最经济的系统方案。本文以流量为106 m³·d^?1的分输站为例，用HYSYS模拟计算直接膨胀发电、制取干冰、制取液化天然气三种压力能利用方案在不同初始压力、不同压差下的产出，并用净现值法分析方案经济性，结果表明：利用压力能制取LNG具有最好的经济性，并且对分输站初始压力和压差要求低；只有当分输站初始压力和压差达到某一值时，利用压力能膨胀发电才能产生经济效益；只有当分输站初始压力和压差达到某一值时，利用压力能制取干冰才能有产出；当分输站初始压力和压差处于中等条件时，直接膨胀发电经济效益好于制取干冰，当初始压力和压差足够大时，制取干冰经济效益好于膨胀发电。

Economic analysis of pressure energy utilization in natural gas distribution station

There are various ways to utilize pressure energy in natural gas distributing stations. It is necessary to select the most economical system according to the conditions of station. Taking a distribution station with the flow rate of 10⁶ m³·d^-1 as an example, HYSYS is used to calculate the output of three systems (power generation by expanding directly, dry ice production and liquefied natural gas production) under different initial pressures and pressure drops. This paper uses the net present value to analyze the economy of these three systems and choose the most suitable one based on their advantages and disadvantages. The results show that utilizing pressure energy to produce LNG has the best economy, and it has low requirement for the initial pressure and pressure difference; only when the initial pressure and pressure difference reach certain conditions, utilizing pressure energy to generate power can be valuable; only when the initial pressure and pressure difference reach certain conditions, the system to produce dry ice can work. When the initial pressure and differential pressure are in moderate conditions, the economy of direct expansion power generation is better than that of producing dry ice. When the initial pressure and pressure difference are large enough, the system producing dry ice is more economical than power generation.