Modeling And Research On Cost Allocation Of Cogeneration Of Heat Power And Cool Units

The cogeneration unit of heat power and cool has high energy efficiency,which can satisfy diversified customers' needs.But the price of its product,including cold,hot and electric is influenced by many factors,such as policy and economic cost,and there is no uniform standard,which restricts the development of cogeneration unit.Product cost is the basis of pricing,and cost allocation is an important part in the product cost calculation.Choosing reasonable cost allocation method to reflect the principle of high quality and good price,is related to the vital interests of users and enterprises.Based on the cost allocation method of combined heat and power generation and Exergy analysis,this paper is combined the structural theory in thermal economics with the improved energy quality coefficient allocation method,the cost allocation model of cogeneration units is established in this paper.The working process of the energy release side of the system is divided into several micro-elements,which can reflect the relationship between the energy quality change and the cost of the thermal economics in the unit production process.First,the advantages and disadvantages of the traditional cost allocation methods of combined heat and power generation are introduced.And the cost allocation model of the cogeneration units,based on the definition of "fuel-product",quantifies the process of production interaction between equipment units,and obtains the unit thermal economics cost of each state point.Then,the total ther mal economics cost of the energy conversion of the system equipment is calculated by the integral,and then the cold,heat and electricity cost of the unit are gained.Second,taking a combined heat and power generation unit as an example,this paper validates the cost model of the cogeneration units based on the structural theory and compares it with the traditional universal matrix model.The results show that the unit exergy cost differences of fuels and products between the two models are no more than 3%,which satisfies the project allowable range.Then,using the cogeneration cost allocation model,the cost of electricity,cold and heat products of the gas-steam combined cycle unit in a future technology city is calculated.And based on the structure theory,the model equations of three kinds of cost allocation methods are established,including product Exergy equivalence method,energy quality coefficient method and improved energy quality coefficient method.The results of the contrastive analysis show that improved energy quality coefficient method can deepen the working process of the group element,and change the traditional way which only according to the energy Exergy value on the boundary to distribute energy cost.It makes the cost allocation r esult more accurate and reasonable,and the cost of the products is more objective and fit the actual engineering situation.Finally,according to the power price establishment mechanism of cogeneration units in China,the economic performance of gas-steam combined cycle unit is evaluated and analyzed,and the relationship between total investment,electricity,natural gas price,heat price and electricity price is analyzed in the 8% case of benchmark yield.