| Using LNG as the gas source,L-CNG filling stations fill the CNG cars by compressing LNG to 25 MPa through reciprocating cryogenic pumps and then gasification.In recent years,the price advantage of imported LNG is gradually becoming notable.So gas station operators have invested in some new L-CNG filling stations or adding L-CNG facilities on the basis of the original gas station.Because of the late start of L-CNG filling stations in China,the related research is incomplete.In the actual operation of L-CNG station,it often emerges problems such as the higher actual energy consumption than the expected,the waste of resources and overloaded operation on account of the mismatch of selection and filling ability of equipment,and the phenomena such as dysfunction of reciprocating cryogenic pump,cavitation and empty cars caused by the unreasonable layout of gas pipeline in L-CNG filling stations.Therefore,the analysis of energy consumption and system configuration of L-CNG filling station and the deep research of the station optimization process piping are in need which can provide theoretical and technical support for the design and operation of L-CNG gas stations and make the operation more economic and reasonable.In this paper,it describes the gas station system configuration and related technology based on L-CNG station system configuration and operation energy consumption,analysis of gas station operation in the process of energy consumption distribution,inhalation performance of maximum energy consuming unit pressurization system in gas station and simulation of gas station filling process and supply mode.The specific works are as follows.First,the L-CNG gas station system configuration and related technology to understand gas consuming regulation through the investigation of different data are elaborated.Based on that,it provides relevant selection methods on key equipment on filling stations(LNG tank,LNG pressurized gasification device,charging device etc.)in different objective conditions.Second,this paper analyzed the operation of L-CNG filling station in the process of energy consumption through the definition of gas station operation process energy consumption evaluation scope,selected of unit product direct comprehensive energy consumption as the analysis basis,converted the energy consumption of L-CNG into standard coal consumption quantity,studied the way and characteristics of energy consumption of each process and revealed that compression system is the most energy-consuming segment.Third,the suction performance of L-CNG filling station turbocharging system and the unsteady flow Bernoulli equation to analyze necessary conditions of low temperature high pressure pump for normal inhalation are studied.Reciprocating cryogenic pump NPSH(net positive suction head)is used to explain the reciprocating cryogenic pump to meet the requirements of normal work.The influencing factors of low temperature and high pressure pump NPSHa is calculated and analyzed by MATLAB.The NPSH(a)value analysis platform is established based on the MATLAB GUI,and the platform is used to evaluate the pressurization system of the actual filling station.Fourth,on the foundation of simulation of gas station filling process and supplication mode,the mathematical model of CNG automobile gas filling process and the simulation of gas filling in the L-CNG gas station is carried out.In order to achieve the largest gas utilization rate,the matching ratio of high,medium and low pressure cylinders is determined,as well as the switching pressure differential.Based on the calculation of the working sequence of two different air supply modes(gas supplication by only gas storage cylinders group and by gas storage cylinders group along with reciprocating cryogenic pump),the optimal gas supplication mode under the special condition of L-CNG filling station is analyzed. |
