The Study For Evaluative System Of Natural Gas Form Used As Vehicle Fuel

It is universally acknowledged that liquefied natural gas as motor fuel attracted attention for its excellent emissions, safety and economy. However, a major shortcoming of natural gas as fuel for vehicles is too low energy density. Natural gas storage is a crucial technology in the commercial utilization of natural gas, the form of natural gas utilization in the vehicle mainly contain compressed natural gas (CNG) and liquefied natural gas (LNG). CNG automobile is earlier putted into business action for maturity of technology, and has been widely used around the world. Many cities of china are actively promoting the technology and has achieved remarkable economic and social benefits. With the low-temperature refrigeration technology being improved, LNGV market is moving towards. Compared LNG and CNG, LNG is better than CNG in environmental protection and usable convenience, but slightly worse than CNG in economy, and security is different in different aspects. Therefore, LNG and CNG comprehensive evaluation is a systematic project. It has a strong practical significance to offer reference in the macro decision-making of NGV development for government and to offer theoretical support in choosing alternative fuels for automobile owner, fuel filling companies and transport companies that we explore their advantages.Based on the theory of systems engineering, this article put natural gas that contain same components into the comparison platform. According to the factor which every component of NGV industry chain evaluate when they select automobile fuels, the corresponding mathematical model is established, qualitative and quantitative analysis is carried on, and the analysis method based on importance level of index is applied to compare the advantage of LNG and CNG. The main research results and characteristics of thesis are as follows:(1) Based on analyzing and summarizing the research work at home and abroad, the capacity of putting LNGV into action is demonstrated from the LNGV-promoted qualification: the source of LNG gas, the technology of LNG filling stations, the technology of LNGV applications.(2) This article follows the general steps of systematic evaluation and the general principles of evaluation index system, and establishes the structure of evaluation index system that by which way natural gas is applied in vehicle. Then it is analysis that which form is manifested when natural gas explore by variety case. And tree figure of natural gas fire and explosion is established.(3) The possibility and the injury extent of LNG and CNG storage tanks explosion, the economic benefits of every element in the industrial chain, the usable convenience of natural gas vehicles, environmental protection and other aspects is analysis and compared, and calculated the specific data.(4)The analysis method based on importance level of index and Multi-objective fuzzy decision method of quantitative indicators is united to analysis. The analysis method based on importance level of index is applied to determine the importance level of index. According to the specific data of index, Multi-objective fuzzy decision method of quantitative indicators is applied to analysis and compare the advantage of LNG and CNG. We can know whether LNGV should be developing from the specific data.(5) It is example of the analysis that Xichang should choose which mode of transporting LNG and that Maoxian should put LNGV or CNGV into action.