Study On Optimization Matching Technology Of Gross Energy Hierarchical Utilization For Marine Diesel Engine

Aimed at waste heat recycling of the low speed marine diesel engine,based on the principle of "According to the quality of energy,each with its" and "By the quality of energy,quality matching",the paper sets up the system simulation model of gross energy hierarchical utilization for marine diesel engineon the basis of the analysis of the energy and energyquality.Studying on optimization matching technology of gross energy hierarchical utilization for marine diesel engine,realizing the reasonable utilization of the total energy of the system,and the thermal efficiency of the system is improved greatly,and the energy recovery effect of the system is remarkable.Having theoretical guidance and practical value in engineering for the design of gross energy hierarchical utilization system for marine diesel engine subsequently.Based on the theory and method of energy analysis based on heat balance analysis and yòng balance analysis,this paper analyzes the grossenergy of marine diesel engine,and puts forward the corresponding system scheme of gross energy hierarchical utilization for marine diesel engine.And marine diesel engine model,power turbine model,the Rankine cycle system simulation model and the diesel engine compound power turbine system model,the diesel engine combined with the Rankine cycle system model,the diesel engine compound power turbine system combined with the Rankine cycle system model are established.Aiming at the different schemes of the total energy hierarchicalutilization system of marine diesel engine,the diesel engine compound power turbine system,the diesel engine combined with the Rankine cycle system,the diesel engine compound power turbine system and the Rankine cycle system are carried out with the aim of the highest system energy efficiency and thermal efficiency as the goal,Which can be used to optimize the matching of the system,and the recovery effect of the residual heat energy is analyzed.The results show that the diesel engine compound power turbine system combined with the Rankine cycle system has obvious superiority compared with the diesel engine compound power turbine system and the diesel engine combined with the Rankine cycle system.Under the 85% working condition,the thermal efficiency of the diesel engine compound power turbine system combined with the Rankine cycle system can be achieved the best 50.38%,and has the best economic efficiency.In 100% operating conditions,the power turbine’s net power recovery accounts for 3.19% of diesel power,and Rankine cycle system accounts for 6.14%,the thermal efficiency of total systemincreases 3.33%.The energy efficiency of the diesel engine compound power turbine system combined with the Rankine cycle system is calculated,and based on the calculated results,the thermal(energy)flow diagram,the Yòngflow chart and the heat flux energy level chart of the total system are presented.The results show that the recovery Capacity and Yòngefficiency of the power turbinecan be improved by increasing the isentropic efficiency.The waste heat boiler and steam turbine can be used as the weak link of the total energy utilization system,the improvement of the waste heat boiler and steam turbine can be one way to higher Yòngefficiency.Different energy levels of their ability to do different,the higher the level of energy to do more power.Finally,the technical and economic analysis of the three schemes shows that the diesel engine compound power turbine system combined with the Rankine cycle system’s economical and energy saving are superior to the diesel engine compound power turbine system,the diesel engine combined with the Rankine cycle system,having stronger competitive power in the market.