Study On Accounting And Influencing Factors Of Carbon Emission Intensity Of Coal-fired Power Plants

With the proposed goal of"carbon peak by 2030 and carbon neutral by 2060",the coal power industry is facing severe pressure of carbon emission reduction.In order to achieve accurate calculation of carbon emissions at the unit level of coal-fired power plants,three carbon emission sources were selected in the coal burning process,the desulfurization process and the outsourcing power supply process to define the emission boundary,and three carbon emission level evaluation indicators were established for the unit standard coal CO₂generation coefficient of coal-fired units,and the carbon emission intensity of power generation and power supply.Respectively to pulverized coal fired boiler in coal-fired power plants and carbon emissions characteristics of CFB boiler were analyzed,and the research represented by limestone-gypsum method and the half dry flue gas desulfurization methods corresponding to the carbon footprint calculation method,on the basis of carbon balance method and sulfur balance method,put forward a kind of from the power supply coal consumption calculation of coal-fired units power supply carbon intensity method,The calculation model of power supply carbon emission intensity was established.In order to find carbon emission reduction measures from the perspective of operation,establish a conversion model of power supply carbon emission intensity,study the quantitative influence of unit operating state and each component of the generation system on power supply carbon emission intensity,and establish a carbon sensitivity calculation model for the main controllable operation parameters of the unit.The influence of the main controllable operating parameters in the thermal system and the variation of plant electricity consumption on the carbon emission intensity of power supply was studied.The calculation results of an example show that the carbon emission intensity of power supply of a coal-fired unit is negatively correlated with the load rate,and the carbon emission level of the same unit varies greatly under different working conditions and different coal quality.The higher the low calorific value of coal quality,the lower the basic carbon content received,and the lower the carbon emission intensity of coal power supply.The carbon emission intensity of desulfurization power supply is proportional to the received base sulfur content of coal.Different desulfurization methods correspond to different calculation models of carbon emission intensity of desulfurization power supply.Limestone-gypsum flue gas desulfurization method has certain advantages in the control of carbon emission.The unique combustion and two-stage desulfurization methods of CFB boiler make its carbon emission characteristics more complex,which are affected by coal quality,desulfurization efficiency,Ca/S ratio,power supply coal consumption and other factors.When the load of the unit increases,the carbon conversion intensity of the turbine system decreases the most,and the carbon conversion intensity of the plant power system decreases by 20.78%of its own value.The carbon sensitivity of boiler side controllable parameters is much higher than that of turbine side controllable parameters,and the carbon sensitivity of plant power consumption is higher under low working conditions,which has great potential of carbon emission reduction.