太阳能耦合1000 MW二次再热超超临界机组节能优化设计

Energy-saving optimization study on 1 000 MW double reheat ultra-supercritical coal-fired power generation system integrated with solar energy

为降低600℃二次再热超超临界燃煤发电机组的发电煤耗和碳排放量,针对某1 000 MW典型二次再热超超临界燃煤发电机组(方案1),提出耦合太阳能加热除氧器出口回热系统给水的设计方案(方案2),并进行对比研究。采用基于[火用]分析的单耗分析法对比了1 000 MW等级600℃二次再热机组不同方案的热力性能,并分析各方案在变工况下的能耗分布情况。结果表明:二次再热燃煤机组集成太阳能后,显著降低发电煤耗和碳排放量;耦合太阳能的二次再热燃煤机组方案2在各工况下发电煤耗均低于方案1,100%THA工况下,方案2抽取除氧器出口10%、30%、50%、70%、100%的给水用太阳能加热时,发电煤耗分别降低4.59、15.70、24.96、32.56、41.32 g/kWh,碳排放量分别降低12.70、43.50、69.10、90.28、114.50 g/kWh,节煤降碳效果明显;采用单耗分析法研究机组各设备单元的附加单耗,方案2锅炉、回热加热器和冷凝器的附加单耗相比方案1均下降;随除氧器出口给水采用塔式太阳能加热比例的提高,方案2锅炉的附加单耗明显降低,方案2增加了太阳能设备,太阳能的附加单耗高于方案1。因此,耦合太阳能有助于进一步提升火电机组性能。

In order to reduce the coal consumption and carbon emission of 600 ℃ double reheat ultra-supercritical(USC) coal-fired power generation system, an optimized system(scheme 2) for coupling tower solar energy to heat regenerative system feed water out of deaerator was proposed and compared on the basis of a 1 000 MW typical double reheat USC unit(scheme 1). The unit consumption analysis method based on exergy analysis is used to compare the thermal performance of different schemes of 1 000 MW level 600 ℃ double reheat unit and the energy consumption distribution of each scheme under variable working conditions was analyzed. The results show that the integration of solar energy heat into 600 ℃ double reheat USC coal-fired units can effectively reduce the coal consumption and carbon emission of unit. The standard power generation coal consumption rates of scheme 2 are lower than that of scheme 1 under variable conditions. Under 100% THA working condition, when 10%, 30%, 50%, 70% and 100% of the feeding water supply out of the deaerator are heated by solar energy, the standard power generation coal consumption rates of scheme 2 are reduced by 4.59,15.70,24.96,32.56 and 41.32 g/kWh, and the carbon emission are reduced by 12.70,43.50,69.10,90.28,114.50 g/kWh, respectively, so the effect of coal saving and carbon reduction is obvious. The unit consumption analysis method is used to study the additional unit consumption of each equipment unit of the unit. The additional unit consumptions of boiler, regenerative heater and condenser in scheme 2 are lower than that in scheme 1. The additional unit consumption of the boiler in scheme 2 is obviously reduced with the increase of the proportion of tower solarheating, while the additional unit consumption of tower solar energy is increased in scheme 2. Integration with solar energy can further improve the performance of coal-fired power plant.