富氧燃烧系统余热利用优化及经济性研究

Optimization and economic study on waste heat utilization for oxygen-enriched combustion system

以某亚临界600 MW燃煤机组作为参考对象,利用Aspen plus和Ebsilon professional软件建立富氧燃烧发电系统的全流程模型。在此基础上基于能量梯级利用原理,运用等效焓降法提出针对富氧发电、空气分离与烟气压缩纯化子系统的6种不同的余热利用方案,并开展方案比选和经济敏感性分析。结果表明:采用最佳方案后机组热效率提高0.76%,单位供电标准煤耗降低9.50 g/(kW·h);煤价提高导致碳减排成本、供电成本提高,单位投资回报降低;碳税对常规燃煤电站的影响比富氧燃烧电站更为显著,在煤价为210元/t,碳税分别为183.0元/t和167.5元/t时,采用最佳方案的富氧燃烧电站与常规燃煤电站的供电成本和单位投资回报率相同。

With Aspen plus and Ebsilon professional software,the whole process model of oxygen-rich combustion power generation system was established for a subcritical 600 MW coal-fired power unit.On this basis,according to the principle of energy cascade utilization,the equivalent enthalpy drop method was used to propose six different waste heat utilization schemes for the subsystem of oxygen-rich power generation,air separation and flue gas compression and purification,and the scheme comparison and economic sensitivity analysis were carried out.The results show that,the unit’s thermal efficiency increases by 0.76%and the standard coal consumption per unit power supply decreases by 9.50 g/(kW·h).The increase of coal price leads to an increase in carbon emission reduction cost and power supply cost and a decrease in unit investment return.The effect of carbon tax on the conventional coal-fired power stations is more significant than that on oxygen-enriched ones.When the coal price is 210 yuan/t and the carbon tax is 183.0 yuan/t and 167.5 yuan/t respectively,the power supply cost and unit investment return rate of the oxygen-rich combustion power stations adopting the optimal scheme are the same as those of the conventional coal-fired power stations.