Research On Design And Optimization Of Power Generation Process Using LNG Cold Energy

With the development of natural gas industry in the world,it promotes the prosperity of LNG market in the world.Considering the increasingly serious energy demand in China,LNG terminals have been set up in coastal areas to ensure the domestic supply.In the process of LNG utilization,a large amount of cold energy will be released.It is necessary to comprehensively utilize LNG cold energy.LNG cold power generation is one of the most effective ways.Based on this,this paper studies the LNG cold power generation system,mainly including the following contents:?1?This paper reviews,studies and summarizes the utilization of LNG cold energy at home and abroad,the development of LNG cold energy power generation technology,the upgrading and improvement effect of cycle structure.Through research and investigation,the advantages and disadvantages of different cold energy utilization plan measures are clarified.?2?Based on the theoretical point of view,this paper studies and analyzes the release of LNG cold energy and cold energy,LNG gasification characteristics,cascade utilization scheme of LNG cold energy,and the selection of circulation process in different situations.?3?Analyze the screening principle of Rankine cycle working medium,make the primary selection of working medium,then establish a single-stage Rankine cycle system,simulate and analyze the performance of different working medium cycle systems,and on this basis,add a regenerator to discuss the influence of the regenerative structure on the system.?4?Considering the subsection utilization of LNG cold energy,a new type of combined power cycle system is established.The combination of two-stage Rankine cycle and LNG direct expansion cycle is adopted.The Transcritical CO₂Rankine cycle is the first stage cycle,the organic Rankine cycle is the second stage cycle,and the organic working medium is R134a.The two-stage solar energy collection cycle is used as the heat source of the system to establish the physics of the new combined power cycle Model and mathematical model,and analyze the influence of the parameters of the cycle on the overall performance of the system.?5?The communication between MATLAB and HYSYS is realized by COM technology,and the data is combined and interacted.The improved genetic algorithm is adopted,which is a hybrid mode of adaptive and optimal reservation.According to matlab genetic algorithm toolbox,a new program is written.The appropriate variables are selected as the optimization parameters,and the exergy efficiency is taken as the objective function to optimize the new combined power cycle,and the parameters are searched globally to select the optimal operating conditions.?6?The grey box analysis model is used to analyze the condition of the whole circulation system,calculate the efficiency and loss of each equipment,so as to find out the lowest equipment unit.