Abstract:

There is much energy in high pressure natural gas pipeline network，and about 322 kJ/kg pressure energy can be recycled from the depressurization process of natural gas at 25℃ from 4.0MPa to 0.4MPa，however，only a little of which was recycled in the actual depressurization process. This paper describes tow recycling methods of natural gas pressure energy from high-pressure pipeline network，power generation and refrigeration. For power generation，combined with the technology of waste heat recovery and gas turbine inlet air cooling，there are mainly three power generation modes；for refrigeration，the cold energy from natural gas expansion cooling is mainly used for natural gas peak shaving，cold storages，cold water air conditioners，rubber cryogenic grinding and light hydrocarbon recycling. In order to improve the utilization efficiency of natural gas pressure energy，and to expand the flexibility of system operation，a new technology is proposed，which can recover the output power of turbo-expander for compressing refrigerant in the refrigeration system while high pressure natural gas is expanded for low temperature. Thus，the proposed new technology can substantially improve the refrigeration efficiency.

摘要：

天然气高压管网蕴含了大量的能量，25 ℃的天然气由4.0 MPa降为0.4 MPa时，可回收压力能约为322 kJ/kg，而实际过程却很少回收利用。文中阐述了目前高压管网天然气压力能用于发电和制冷的两种主要回收利用方式。在发电方面，结合发电厂的余热回收、燃气轮机进气冷却技术，主要有3种发电方式；在制冷方面，主要是膨胀制冷并用于燃气调峰、冷库、冷水空调、橡胶深冷粉碎以及轻烃回收等。针对目前所存在的问题，为了提高天然气压力能利用效率，扩展该系统操作弹性，文中提出了一种新型工艺，即在高压天然气膨胀制冷的同时，将膨胀机输出功用于压缩冷媒制冷系统，大幅提高制冷效果。