Optimizing Natural Gas Fueling Station Reservoirs Pressure Based on Ideal Gas Model

Abstract

At CNG fuelling station, natural gas is usually stored in a cascade storage system to utilize the station more effi cient. The cascade storage system is generally divided into three reservoirs, commonly termed low, medium and high-pressure reservoirs. The pressures within these three reservoirs have huge effects on the performance of a CNG fuelling station and a fast fi lling process of natural gas vehicle's (NGV) cylinder. A theoretical analysis is developed to study the effects of the reservoirs pressures and temperatures on the performance of the CNG station. The analysis is based on the fi rst and the second law of thermodynamics, conservation of mass and ideal gas assumptions. The results show that as the reservoir temperature decreases, the fi ll ratio increases and the pressure within the fi lling station reservoirs has no effects on the fi ll ratio. The non-dimensional entropy generation and fi lling time profi les have opposite trends and as entropy generation decreases, the fi lling time increases. The optimized non-dimensional low and medium pressure-reservoir pressures are found to be as 0.24 and 0.58 respectively in thermodynamic point of view.

Mathematical modeling of fast filling process at CNG refueling stations considering connecting pipes

“…As is shown in this figure growth rate for temperature at the beginning of the process is higher for the buffer storage system. The same trend in the temperature profile has been seen in previse studies (FarzanehGord et al, 2011(FarzanehGord et al, , 2007(FarzanehGord et al, , 2008Kountz, 1994;Deymi-Dashtebayaz et al, 2012;Farzaneh-Gord et al, 2012a;Farzaneh-Gord and Deymi-Dashtebayaz, 2013;Farzaneh-Gord et al, 2012b, 2014. The final temperature of the actual conditions may be less than the modeling value.…”

The Complete Modelling of the Filling Process of Hydrogen Onboard Vehicle Cylinders

“…It was also found that ambient temperature influences the filling process and storage capacity (Shipley, 2002). Farzaneh-Gord et al (2007, 2008a, 2008b, 2012b, 2012c, 2013b have also simulated the fast filling process of CNG in several studies. The results indicated that ambient temperature has considerable effects on the filling process and final cylinder conditions.…”

Empirical study on the outliers of compressed nagural gas (CNG) refueling behaviors

“…Accordingtothe17thChinainternationalNGVsandgasstationequipmentexhibition&summit forum[1],thereare5,030,000NGVsontheroadinChina,withover4,800,000CNGVs,andover 4,700CNGfillingstations.BoththenumbersofCNGVandCNGfillingstationsaretopoftheworld. Obviously,forCNG'scheaperandfeweremissionthangasoline,thereisroomforsignificantgrowth worldwideandinChina.However,CNGVsrequireagreateramountofspaceforfuelstorage [2,3]. TheonboardstoragecapacityofNGVislimited.InChina,afullyfilledtankofCNGVcanrunabout 200km.Therefore,aCNGVdriverhastorefuelthenaturalgaspoweredvehiclefrequently.Butthe numberofCNGsecondaryfillingstationsislimitedanditseffectivenessisneedtobeimproved.In Tianjin,CNGVdriversneedtowaitmorethan2hourstofillupthenaturalgasvehicles.…”

“…Therefore,toimprovetheCNGrefuelingeffectivenessisnecessaryandimportant,andalotof studieshavebeendone [2][3][4][5][6].Abibliography [7] …”