Thermoeconomic Analysis And Optimization Of A Combined Cooling,Heating And Power System Based On AA-CAES

Nowadays it’s pressed for increasing the proportion of renewable energy utilization and reducing the consumption of fossil fuels to figure out the energy crisis and environmental pollution.However,the grid-connected progress faces huge challenges because the renewable energy is difficult to predict and control.In addition,the total amount of electricity consumption is rising rapidly as the economy advances,and the power shortage are also getting worse.Electric energy storage technology can stockpile the electricity during non-rush hour and release it to the user during rush hour,which has been proved to be a better choice to solving these problems.Compressed air energy storage is regarded as one of the best methods due to its high reliability,low cost and low environmental impact.Traditional compressed air energy storage uses gas turbine to generate electricity during the energy release stage,which not only consumes fossil fuels,but also causes greenhouse effect.Therefore,an advanced adiabatic compressed air energy storage(AA-CAES)system was put forward to recover and utilize the compressed heat through a heat storage device,thus eliminating the need to burn fossil fuels at the discharge time,and finally achieving clean and pollution-free.To improve the energy utilization rate of AA-CAES system,realize the cascade utilization of energy,and satisfy the diversified requirements of society,this article put forward a CCHP system based on AA-CAES.Through simulation,the thermo-economic performance of the system in operation are explored and discussed.The major research details and verdicts are:(1)The thermodynamic model,exergy analysis and economic model of the CCHP system based on AA-CAES are established.Five heat distribution schemes are proposed,and the thermodynamic and economic performance of the system under five patterns are contrasted through numerical modeling.The research finding that the higher the heat distribution ratio,the higher the exergy efficiency and the smaller the annual profit margin.(2)To deeply study the influence of different working medium and export patterns on the property of the CCHP system based on AA-CAES,four operating schemes are proposed.Through simulation calculation,the difference the thermodynamic and economic characteristics of the system under four different schemes are compared and analyzed,and the sensitivity of the critical parameters are explored.It is found that the exergy efficiency of scheme two is the highest while the annual profit margin of scheme four is the largest.The exergy efficiency and annual profit margin of the four schemes reduce with the extend of time interval.As the convective heat transfer coefficient becomes bigger and bigger,the exergy efficiency and annual profit margin of the system decrease first and then increase.The higher the initial pressure of working medium,the higher the exergy efficiency and annual profit margin of the four schemes.(3)The model of the AA-CAES coupled with solar auxiliary heat system are established.The thermodynamic and economic properties of the two systems with imparity export patterns are compared,and the sensitivity of the basic parameters are studied.The consequences expressed that the exergy efficiency is the maximum when the original system employs scheme one,while the annual profit margin is the biggest when the coupling system employs scheme two.It has a positive effect on the exergy efficiency and annual profit margin of the two systems when the energy storage power increase,while the increase of energy release power has a negative effect on them.When the environmental pressure increases,the exergy efficiency and annual profit margin of the two systems under different schemes all increase.