Optimization Of Energy-Saving System In Food Industry Based On Combined Cooling And Heating And Cascade Energy Consumption

At present,exploring clean and low-carbon industrial energy supply mode is an important direction of energy saving and emission reduction.In order to solve the problems of single cold and heat source and unreasonable energy consumption system in food industry,this paper puts forward a system integration idea based on cold and heat joint preparation and cascade energy consumption,realizes cascade heating and cooling of the system with lower heat source(cold source)cost,establishes a new system comprehensive energy efficiency evaluation method,and conducts in-depth research around system integration optimization and operation.Firstly,a system based on cold and heat combined preparation and cascade energy consumption is constructed,and the basic mathematical model and TRNSYS system simulation model are established respectively for the heat pump,cascade heating(cooling)system and heat storage system of cold and heat combined preparation.In addition,for the new industrial energy-saving system,the multi-objective evaluation index and method are established,which provides the necessary theoretical basis for the optimization and integration of the new system.Secondly,TRNSYS software is used to simulate the heat pump with combined cold and heat preparation,in which,the off-design characteristic analysis program of electric compression heat pump is written by C++ language,and the influence of outlet temperature of evaporator side and condenser side of heat pump on each performance coefficient of heat pump is analyzed,and the integration law of heat pump with combined cold and heat preparation is obtained,which provides theoretical analysis for the integration optimization and operation of the new system.Thirdly,the cascade heating(cooling)system is simulated by TRNSYS software,and the Hooke-Jeeves optimization algorithm is called to optimize the key parameters of the system with the minimum annual cost as the optimization goal.In the daily periodic operation,the operation strategies with the priority of improving the energy efficiency of heat source and reducing the energy cost are designed respectively,and the optimal effects of the annual performance coefficient and annual cost of the system under different operation strategies are compared.Finally,taking a meat processing factory in Qinhuangdao as an engineering case,a system integration design based on cold and heat combined preparation and cascade energy consumption is carried out,and the application of the optimized new system and the conventional cold and hot water preparation scheme is analyzed and compared from the aspects of energy saving,environmental protection and economic performance.In addition,the sensitivity analysis of uncertain factors such as equipment unit price and regional electricity price is carried out to test whether the new system scheme has good anti-risk ability.