水煤浆热电联产集中供暖系统[火用]环境分析

Exergoenvironmental analysis of a combined heat and power system for district heating using coal water slurry

采用清洁燃料水煤浆的热电联产系统被视为传统燃煤系统的高效替代,目前缺乏针对此类系统环境性能的定量评价研究,且现有研究大多建立在仿真模型的基础上。本文以某实际运行的热电联产集中供暖系统为例,采用[火用]环境分析方法,对其热力学性能和环境学性能进行了量化评估。从系统和设备2个层面,确定了其性能水平和提升潜力。结果表明:该系统热力和电力的单位[火用]环境学影响值分别为5 434 mPts/GJ和3 617 mPts/GJ,环境学影响的主要来源为设备内部[火用]损失,改善措施主要为提高设备[火用]效率;水煤浆锅炉和汽水换热器具有较大的环境学性能提升潜力。

The combined heat and power(CHP)system using clean fuel coal water slurry has been regarded as a high-efficiency alternative for conventional coal-fired district heating systems.However,there is a lack of quantitative evaluation of the environmental performance of such systems,and the previous research is mostly based on the simulation model.In this paper,taking an actual running CHP system for district heating as an example,the thermodynamic and environmental performances are quantitatively evaluated by means of exergoenvironmental analysis.From the two levels of system and equipment,the performance level and improvement potential are determined.The results show that the environmental impacts per unit exergy of thermal and the power of the system are 5434 mPts/GJ and 3617 mPts/GJ,respectively.The exergy destruction of system components is the dominant source of total environmental impacts,and the improvements in the environmental performance should focus on enhancing components’exergy efficiency.The coal water slurry boiler and the steam-water heat exchanger have greater potential to improve environmental performance.