Research On The Thermal System Optimization Of Carbon Capture In Solar Assisted Coal Fired Power Plant

Environmental and energy issues are currently important international issues that need to be resolved urgently.Coal combustion in China accounts for 76.8%of carbon dioxide emissions.Among them,the carbon emissions of thermal power generation account for about 38%of the country’s total.Carbon capture technology is an effective measure to solve the large carbon emissions of thermal power generation and has broad development prospects.Solar energy,as one of the clean energy sources,is abundant in China and is the most ideal external clean energy source.Related national policies also indicate that the future development of the energy industry will focus on renewable clean energy sources.This article takes a 1000MW coal-fired unit as a reference object,adds a carbon capture system,and captures the CO₂emitted by the power plant.Due to the huge energy penalty caused by the addition of a carbon capture system,a solar-assisted coal-fired power plant carbon capture scheme is proposed.Solar thermal field replaces coal-fired power plants and carbon capture systems to do work to make up for energy losses.Six types of steam supply methods for carbon capture systems were proposed,and the proposed scheme was simulated and calculated using EBSILON thermal balance calculation software.The results were analyzed for thermodynamic performance.It was found that when the secondary reheat cooling section was used to supply steam,the unit cycle The thermal efficiency is the highest of the six extraction schemes,which is 44.06%.The CO₂emission rate is the lowest,as low as122.06g/（k W×h）.The standard coal consumption rate and heat consumption rate for power generation are the lowest.Based on the steam resupply scheme in the secondary reheating and cooling stage,three types of carbon capture schemes for solar-assisted coal-fired power plants were proposed.After calculation,the high-energy-consumption scheme for solar energy was used to make the CO₂emission rate of coal-fired power plants Reduced 594.87g/（k W·h）,the decarburization rate reached 85%.Based on the coal-carbon capture system,the output of the solar-assisted coal-carbon capture system has increased by 237.449MW,the cycle thermal efficiency has been increased by 9.59 percentage points,and the CO₂emission rate has been reduced by 21.83g/（k W·h）.Economic indicators such as investment in coal saving,average solar carbon capture cost,and leveled power generation cost are introduced to analyze the integrated system.In order to analyze the energy distribution of the system and evaluate the rationality of the energy utilization of the system,this paper uses the unitary equilibrium analysis method to evaluate the integration method.The results show that the boiler damage is the largest among coal-fired units and coal-carbon capture units,accounting for more than 90%of the machine’s damage,and the efficiency is the lowest.After the introduction of the solar thermal field,the solar thermal field has the lowest efficiency,and the maximum loss is the largest other than the boiler.For the solar thermal field,the schemeⅠhas the highest efficiency and considers the most reasonable use of solar energy.