Study On The Dynamic Cost Of Cooling,heating And Electric Power Of Integrated Energy System

Traditional energy supply systems have low energy efficiency and high carbon emissions,which lead to increasingly prominent energy and environmental problems.However,the distributed integrated energy system(IES)for combined cooling,heating and power(CCHP)has great development potential in improving energy utilization rate,improving environmental benefits and realizing energy cascade utilization.One of the key problems of IES system research is the cost allocation problem caused by multi energy flow coupling.The research of cost allocation usually adopts heat method or actual enthalpy drop method,the core of which is to regard heat energy or electric energy as main product,and the other as by-product.This kind of allocation method only pays attention to the influence of "quantity" and ignores the cost difference caused by different energy tastes.Thermoeconomic analysis method can simultaneously consider the impact of energy quality and quantity on product cost,and can quantify the difference of different energy quality.The existing thermoeconomics research mainly focuses on the product cost of polygeneration system in the industrial field.Most of the system equipment is in steady-state operation condition,so the product cost is constant and belongs to static cost.However,the existing integrated energy system mainly serves the construction field dominated by the park,and the cooling,heating and power load demand of the user side is dynamic,which may lead to the equipment operating under partial load condition,and then cause the dynamic change of product cost.In addition,in the context of the vigorous development of photovoltaic po Wer generation and energy storage technology in the integrated energy system,the randomness and uncertainty of photovoltaic power generation and the periodicity of energy storage device scheduling greatly increase the complexity of the system cost allocation.Therefore,this paper introduces the dynamic economic model to realize the analysis of the impact of photovoltaic system and energy storage device on the cost sharing of cooling,heating and power of integrated energy system under dynamic load.The results can provide theoretical support for the reasonable pricing of integrated energy services products and the optimal design and operation of the system.The main research contents and results are as followsFirstly,the theory of thermoeconomics is introduced,and the basic ideas of thermoeconomics research and the related concepts of thermoeconomics cost are introduced in detail.By comparing the existing thermoeconomics analysis methods,the advantages and disadvantages and applicability of each analysis method are summarized.Taking matrix model thermoeconomics as the basic research tool,the calculation method of product cost is deeply studied by using matrix analysis method,and the core of matrix model thermoeconomics analysis method is revealed.Taking the Jinghu project as an example,the energy quality coefficient method is used as the principle of establishing the supplementary equation to reasonably solve the product cost of the polygeneration system in the example.Secondly,taking No.3 energy station in Jinghu District,Shaoxing City,Zhejiang Province as the project background,based on the theory of thermoeconomics,the flow chart of the integrated energy system is drawn and the value table of the system under rated conditions is calculated.On this basis,the equilibrium equation matrix and supplementary equation matrix of thermoeconomics are listed by matrix analysis method,and the static cost of system products is obtained.The unit electric power,unit cold po Wer and unit thermal power are 0.69,0.29 and 0.33 yuan / k W.h,respectively.By changing the gas price,investment payback period and unit capacity price of equipment,the cost sensitivity analysis of cooling,heating and power products is carried out.The results show that with the increase of gas price,the cost of cooling,heating and po Wer increases,and the cost of electricity is the most sensitive to the change of gas price,follo Wed by cooling load.With the increase of payback period,the cost of cooling,heating and po Wer increases.The electricity cost increases rapidly with the increase of unit capacity price of internal combustion engine,While the cooling cost increases with the increase of unit capacity cost of lithium bromide unit.Finally,the dynamic thermoeconomic model of integrated energy system is proposed and established,and the product cost of integrated energy system with photovoltaic modules and cold storage devices is analyzed in depth.It is proposed to allocate non energy cost according to product output,which solves the problem of product cost allocation under partial load conditions.In addition,the product cost allocation of cold storage devices is studied in depth,and the comprehensive evaluation is carried out considering the influence of energy storage and energy storage time on the cost,the relationship between the product cost of each period of the cold storage device is revealed.The results show that: photovoltaic modules can effectively reduce the cost of cooling,heating and power;energy storage device can absorb the Waste heat of internal combustion engine,so as to improve the system operation economy and further reduce the cost of cooling,heating and power.The product cost allocation of integrated energy system with multi energy flow coupling is a key technical problem of integrated energy services.Reasonable product cost allocation is not only related to the vital interests of energy operators,but also closely related to the energy consumption behavior of users.This study can provide reference for real-time pricing and operation optimization of integrated energy system products.