在“双碳”目标下,天然气压力能回收作为分布式供能系统的关键环节,对降低企业运营成本、实现节能减排具有重要意义，研究余压发电技术在天然气净化厂至输配用环节的适用性是探索压力能高效回收的优化路径。基于某天然气净化厂、输气站及下游用户的实际运行参数,构建余压发电工艺系统模型,采用透平膨胀技术将压差能转化为电能,通过热力学计算与数值模拟对比分析单级/多级膨胀+复热方案的发电性能,结合全生命周期经济性评估优选工艺路线。研究表明:天然气外输工艺中应用余压发电技术具有可行性;采用多级膨胀+复热方案可避免低温结霜问题,较单级膨胀系统提升发电量约15%,投资回收期缩短至6.2年;CO₂减排可达3 159.9 t/a。余压发电技术能有效实现压力能—电能的高效转换,兼具经济性与环保性。在天然气开采、处理、输送、配用全流程环节推广余压发电技术,采用针对性的工艺系统,并融合智能调控系统以动态优化运行参数,可为天然气行业低碳转型提供技术支撑。

Driven by the “Dual Carbon” goals(carbon peaking and carbon neutrality), the recovery of natural gas pressure energy, as a key link in distributed energy supply systems, is of great significance for reducing enterprise operating costs and achieving energy conservation and emission reduction. This paper aims to study the applicability of residual pressure power generation technology in the process chain from natural gas purification plants to transportation, distribution, and end-use, and explore the optimization path for efficient pressure energy recovery. Based on the actual operating parameters of a natural gas purification plant, gas transmission stations, and downstream users, a process system model for residual pressure power generation is developed. Turbine expansion technology is used to convert differential pressure energy into electrical energy. The power generation efficiency and performance of single-stage/multi-stage expansion+reheating schemes is compared and analyzed through thermodynamic calculations and numerical simulations, and the optimal process route is selected by combining life-cycle economic evaluation. The research shows that: the application of residual pressure power generation technology in natural gas export processes is feasible; The multi-stage expansion+reheating scheme can avoid low-temperature frosting issues, increase power generation by approximately 15% compared to the single-stage expansion system, and shorten the investment payback period to 6.2 years; The annual reduction of CO₂ can reach 3 159.9 tons. Residual pressure power generation technology can effectively achieve efficient conversion of pressure energy to electrical energy, combining economic and environmental benefits. It is recommended to promote residual pressure power generation technology in the entire process of natural gas production, treatment, transportation, and distribution, adopt targeted process systems, and integrate intelligent control systems to dynamically optimize operating parameters, providing technical support for the low-carbon transformation of the natural gas industry.