地热与生物质直燃耦合的热电联产系统热力学性能分析

Thermodynamic Performance Analysis of Cogeneration System for Coupling of Geothermal and Biomass-fired Plant

提出不同温度地热水与生物质热电联产机组集成的新耦合系统。该系统将地热能集成到生物质热电联产机组的汽水循环中,取代部分汽轮机抽汽。基于某35 MW生物质热电联产机组对新耦合系统的热力学性能进行评估。结果表明:对于地热水温度为110℃的新耦合系统,抽取的地热水处于较高温度,可以作为驱动热泵的热源,节省了抽汽;新耦合系统发电功率的增加分为3部分,即机组本身改造、新设置的抽引器以及地热辅助;不同地热水温度下新耦合系统的总[火用]效率均有较大提升;新耦合系统具有显著的经济优势。

A new coupling system integrating geothermal water under different temperatures with biomass cogeneration units was proposed,in which,geothermal energy was integrated into steam-water cycle of the biomass cogeneration unit to replace part of extraction steam of steam turbine.Based on a 35 MW biomass cogeneration unit,thermodynamic performance of the new coupling system was evaluated.Results show that for the new coupling system with geothermal water temperature of 110℃,the extracted geothermal water is in a state of relatively high temperature,which can be used as the heat source to drive the heat pump and save extraction steam.The increase of generation power of the new coupling system can be divided into three parts,including the transformation of the unit,the newly set extractor and geothermal auxiliary.Total exergy efficiency of the new coupling system can be greatly improved under different geothermal water temperatures.The new coupling system shows significant economic advantages.