Modeling And Capacity Optimization Of Ship Comprehensive Energy System

The huge energy consumption of the shipbuilding industry has brought serious energy crisis and environmental pollution problems.The relevant ship energy efficiency rules and pollutant emission requirements are becoming more and more stringent.Therefore,it is urgent to improve ship energy efficiency,energy conservation and emission reduction.As a new energy system with high efficiency and environmental protection,ship comprehensive energy system is an important development direction of ship industry in the future.Aiming at the shortcomings of the existing research on ship comprehensive energy system,this thesis studies the modeling,simulation and capacity optimization of ship comprehensive energy system.Firstly,taking"Yu Kun"as the research object,the cold,heat and electric loads of its berthing conditions in summer are estimated.According to the load index method,the cooling load of the ship is estimated to be 520k W;Considering that the heat load under this working condition is mainly domestic hot water,the heat load of the ship is 108k W according to the domestic hot water load estimation method in the residential area;According to the demand coefficient method,the electrical load of the ship is 362k W.Then the Simulink simulation model of ship comprehensive energy system is established and verified.The system takes the gas turbine as the prime mover and is based on the principle of cascade utilization of energy.High-grade energy is used for power generation and low-grade energy is used for refrigeration and heating.Based on the cooling,heating and electric load information of"Yu Kun",select the gas turbine,lithium bromide refrigerator and heat exchanger in the system;The gas turbine and its control system,electrical equipment,lithium bromide refrigerator,heat exchanger and other equipment in the system are introduced in detail,which are mathematically modeled and simulated with MATLAB/Simulink;The error between the reference data and simulation data of the design point parameters of the calculation equipment is less than 2%,which shows that the built ship comprehensive energy system has high accuracy and certain practicability.Finally,the capacity of ship comprehensive energy system is optimized.Establish capacity optimization model with energy efficiency,economy and environmental protection as optimization objectives;Genetic algorithm is selected to solve the capacity optimization model to obtain the optimal capacity allocation of the system;In the case study,in terms of energy efficiency,compared with the original system of"Yu Kun",the energy utilization rate of the ship comprehensive energy system is increased by 43.3%.After optimizing the capacity of the ship comprehensive energy system,the energy utilization rate of the system is further increased by 5.7%;In terms of economy,compared with the total cost of the original system of"Yu Kun",the total cost of the ship comprehensive energy system increased by 74.45%,and the total cost of the optimized ship comprehensive energy system decreased by 10%;In terms of CO₂emissions of ships after the optimization of the original energy system,the annual CO₂emissions of ships have been reduced by 87.3%compared with that of the original energy system.Through the analysis of capacity optimization results in terms of energy efficiency,economy and environmental protection,it is concluded that the optimized ship comprehensive energy system has the best performance in three aspects,which verifies the necessity and effectiveness of capacity optimization of ship comprehensive energy system.