The Performance Analysis Of The Integration Of A Coal-Fired Power Plant With An Ammonia-Based CO₂ Capture Process

At present,the rising temperature that mainly caused by CO2 emissions,has become one of the major environmental concerns in the world.China leads the world in CO2 emissions,most of which come from coal-fired power plants.Therefore,reducing the emission of CO2 of coal-fired power plants as much as possible is of great significance to the emission reduction of CO2 in China and slowing down the rise of global temperature.In the current research,chemical absorption method is relatively advanced in capturing CO2,among which NH3-based CO2 capture method has attracted the attention due to its advantages of large capture volume,not easy degradation to produce harmful substances,and high capture efficiency.However,the CO2 regeneration process of a carbon capture system requires an external supply of heat,which is usually provided by the extraction of steam from coal-fired power plants,resulting in a decrease in the efficiency of coal-fired power plants.Therefore,how to reduce the energy consumption of carbon capture system and improve the efficiency of the coal fired power plant which integrated with CO2 capture system is the focus of current research.In this paper,a 660MW coal-fired power plant is taken as the research object.Based on EBSILON software and the principle of energy cascade utilization,a simulation is built to simulate its integrating with the advanced NH3 based CO2 capture system.Steam is extracted from the drilling of the LP turbine,and the condensed water is returned to the deaerator through the reboiler.Based on this model,the output reduction mode,the constant output and CO2 capture amount mode,and the constant output and CO2 capture rate mode are analyzed.The output power of the selected optimized operation mode is guaranteed to remain unchanged,with the efficiency reaching 42%.The influence of different cooling modes on water consumption under different operating modes is further considered.Under the three operating modes,the coal fired power plant and carbon capture power plant both adopt the natural draft cooling tower which is 45.69%higher,66.64%higher and 64.86%higher than the original coal fired power plant respectively.The water consumption of the integtaion system that the coal-fired power plants adopt natural draft cooling tower,and the CO2 capture system adopts air cooling system,decreases by 20.82%,11.48%and 10.21%respectively compared with orginal coal-fired power plants.The energy penalty may be the same when the parameters of integration are different.Therefore,the influence of extraction required by CO2 capture system on extraction flow and exergy loss at the regenerative system of coal-fired power plant is further analyzed.It is found that exergy loss is different when the energy penalty is the same,which further provides a direction for system integration.