Design Optimization Of LNG Automobile Filling Station

Compared with fuel and compressed natural gas(CNG),etc.liquefied natural gas(LNG)as automotive fuel has higher safety,better economic returns,and lighter environmental pollution,which develops rapidly with the national application of the clean energy.With the promotion of LNG vehicles,the demand for LNG filling stations is also increasing.TheDesign is an important subject of research on LNG refueling stations.Considering the unreasonable overall technology roadmap of the current design,conservative technological process layout and low economic and technical indexes,this paper mainly focused on the technological process and equipment selection optimization and with in-depth study,the main research work was as follows:Firstly,taking Qingyang LNG station design as an example,the characteristics and application of LNG was studied;LNG station siting principles was expounded;the basic technological process and main equipment were analyzed;and problems over the design and equipment of the existing LNG station were studied.Secondly,considering the characteristics of the LNG filling station equipment,optimized selection and design of major equipment such as storage tanks,LNG cryogenic submersible pumps,vaporizers,cryogenic piping was conducted.Suitable materials were selected through experimental evaluation.Equipment structure was designed to improve equipment insulation performance,to reduce Boiled Off Gas(BOG)loss,and to save construction costs.Thirdly,this paper analyzed the index factors of unloading process,BOG flow.The unloading time was reduced by at least 20% while the BOG was reduced at least up to 20m3 through process optimization arrangement.The pump flow was increased and the piping arrangement was improved to enhance the equipment utilization.Since most of the existing design has no BOG recovery process,the generation process and output of the BOG was analyzed and four different alternatives were designed for technical and economic comparison.Different options can be selected according to actual conditions.Fourthly,automatic control system designs were studied.Security-related station’s equipment,process piping and production were taken into overall consideration.Probability of basic events influencing the security of LNG filling stations was calculated through security tree analysis to identify the most dangerous factor,and to develop countermeasures.Through this study,the technical level of LNG filling stations was improved;the unloading time and loss was reduced;the major equipment insulation performance was improved and the labor intensity in the station was reduced,all of which has good economic and environmental benefits of LNG filling stations and has a guiding role in LNG filling stations design construction.