Coupling Optimization And Trigger Price Of Multi Energy System With Carbon Capture And Power To Gas

The carbon emissions of China’s power system account for about half of the national energy-related carbon emissions.Decarbonization of the power system is crucial for China to achieve the "30·60" climate target.China’s energy situation and power system structure determine that the efficient utilization of thermal power and the high proportion penetration of renewable energy are the key to the future low-carbon energy system.Multi-energy systems with carbon capture system(CCS)and power to gas(P2G)can reduce carbon emissions while increasing the consumption of renewable energy,forming a coupling cycle of carbon chain and energy flow,which helps to realize the synergy between non-renewable and renewable resources and to realize the mutual benefit of renewable energy increment and thermal power stock.However,the complexity of the multi-energy system architecture and operation strategy,the uncertainty of trigger price required for system feasibility,the coupling of impact on different energy sectors and the uncertainty of support policies need to be further studied.Based on the above analysis,this paper takes the multi-energy system with CCS and P2G as the research object,and focuses on the key problems such as its coupling optimization operation mechanism and trigger price mechanism.The main research contents are as follows:(1)The carbon-energy cycle operation optimization model of the multi-energy system with CCS and P2G is constructed,and the system architecture and operation optimization strategy are studied.Firstly,the system architecture of CCS and P2G coupling is designed and extended to the integrated energy system including electricity,heat and gas.Secondly,based on the carbon chain and energy flow cycle,the operation optimization strategy of carbon-energy cycle of the multi-energy system with CCS and P2G are proposed to realize the dynamic utilization and non-fugitive emission of carbon,and energy flow coupling.Finally,through multi scenario simulation analysis,the advantages of the multi-energy system with CCS and P2G in renewable regulation and consumption,carbon utilization,non-fugitive emissions and gas dependence are verified.(2)A multivariate function cost-benefit model of carbon-gas-electricity price is constructed to study the trigger price required for the sustainable development of the multi-energy system with CCS and P2G.First,the coupling model of CCS and P2G is improved,and the system income is expressed as a multivariate function including energy price.In addition,the multivariate function is transformed into a linear function of power generation.By analyzing the properties of the function,the benefit function image is drawn,the functional relationship satisfied by the carbon-gas-electricity trigger price combination under the uncertainty of single,double and triple energy prices is deduced,and the value range of the trigger price combination is obtained.Finally,based on the numerical experiment,the carbon-gas-electricity price trigger combination that makes the net cash flow of the multi energy system positive and its functional relationship are determined,and the critical output of the system is given.(3)A cost-benefit-subsidy nonlinear optimization model under various subsidy modes is proposed to study the subsidy trigger price.The cooperation mode and profitability of stakeholders in the industrial chain of the multi-energy system with CCS and P2G are analyzed,and three suitable business models are designed.Besides,this paper puts forward the cost benefit subsidy nonlinear optimization model under various subsidy models,such as investment subsidy,operation subsidy and double subsidy for investment and operation.The optimization model is transformed into a mixed integer linear programming,which provides a model framework for calculating the trigger price of key parameters and the policy cost of support mechanism.Furthermore,the system benefits under the benchmark scenario and subsidy mode are obtained through simulation,and the combination of energy price and subsidy price that can make the system achieve a reasonable rate of return is calculated.(4)A long-term equilibrium model including electricity,gas and carbon market with multi-agent is constructed to study the price effect of the multi-energy system with CCS and P2G and its impact on the carbon-gas-power sector.First of all,a long-term equilibrium model including power,gas and carbon markets is established.Different markets of specific industries have market clearing constraints through CCS and P2G coupling.Moreover,the optimization problem of each market participant is replaced by equivalent KKT optimality conditions to form an equivalent mixed complementarity problem.The generalized Nash equilibrium problem is solved based on PATH,and the optimal decision-making and long-term equilibrium price of each market participant are determined.Finally.the participation of large-scale multi-energy system with CCS and P2G in the long-term equilibrium of carbon-gas-power market is simulated,and the impact of the multi-energy system with CCS and P2G on carbon-gas-power sector and the significance of coupling between sectors is discussed from short-term and long-term.(5)The incentive policies for the deployment of the multi-energy system with CCS and P2G are proposed.Firstly,the barriers existing in the current deployment situation is combed,including insufficient policy enforceability,exorbitant energy price and unclear financial support.Secondly,the incentive policies are put forward,such as giving full play to the functions of government planning and policy incentive,enhancing policy feasibility,strengthening responsibility awareness,adhering to scientific decision-making,exploring appropriate business models and operation strategies,and strengthening multi-party cooperation.so as to promote the deployment of the multi-energy system.