Comprehensive Evaluation Of Cogeneration’s Heat Utilization, Exergy Transfer And The Carbon Conversion

The main source of CO₂emissions is the combustion of fossil fuels, As themain burning equipment of fossil fuels,boiler has close relationships to globalwarming and greenhouse effect.Fossil fuels include natural gas, oil and coal. Most ofthe carbon dioxide is produced by the coal combustion due to the the coal’s C/H ratiois minimum in its chemical.Owing to consumes about one-third of the coal,industrialcoal boiler has became an important source of greenhouse gases in our country.Energysaving is exergy saving because of energy is conserved,the actual process isirreversible and actual process is a energy quality process.Exergy analysis of energysystems and calculation of internal and external system of the irreversible exergyloss,exergy efficiency,exergy loss rate, etc can reveal the weak link of energy-usingprocesses.The purpose of energy saving can be achieved according to the results ofthe analysis.Firstly，this paper analyzes the present situation of energy utilization and thecharacteristics of carbon emissions in the context of global warming and promotinglow-carbon economy.This system dynamics model based on the analysis of the solidmineral fuel row carbon system’s feedback interactive mechanism among variouselements is established and the method of system simulation and STELLA softwareare applied to the model so that this model can predict and analysis the solid mineralfuel CO₂emissions.Then,this article sums up the CO₂emissions enlightenment andcountermeasures;This paper establishes the model of coal-fired,fuel-gas and fuel-oilboiler emissions of carbon dioxide and advances a new definition called "efficiency ofa coal-fired boiler carbon",the relationship between coal-fired boiler efficiency and itsthermal efficiency are also analyzed in this paper.Then this paper put forward theappropriate suggestion about boiler equipment modification technology to provide therelated basis on improving the efficiency of the boiler so as to reduce carbon dioxideemissions, reduce air pollution and realize sustainable development, to promote theharmonious development of the economy and environment to provide the related basis.This paper also introduced the the concept of mass quality coefficient andconversion mass quality coefficient,calculated the mass quality coefficient ofdifferent energy and deduced the relationships among exergy efficiency, energyefficiency and mass quality coefficient. In the last chapter, this paper puts forward amathematical model of cogeneration exergy analysis and calculates the related data onthe basis of the actual data, According to the results, boiler is the biggest exergy lossequipment of this cogeneration.Finally,thispaper discusses impact of the main steamtemperature and the pressure change on exergy efficiency of Cogeneration systemCarries on the analysis of Heat utilization, process of exergy transfer andcarbon conversion of the cogeneration system can provide a theoretical basis onreducing carbon emissions,the air pollution,sustainable development,promoting theharmonious development of the economy and environment.