Prediction of Fuel Vapor Generation From a Vehicle Fuel Tank as a Function of Fuel RVP and Temperature

1989 ◽  
Author(s):  
S. Raghuma Reddy
Trudy NAMI ◽  
2021 ◽  
pp. 74-86
Author(s):  
G. G. Ter-Mkrtich'yan

Introduction (problem statement and relevance). Hydrocarbon emissions from vaporizationtank fuel contribute significantly to the total emissions of hazardous substances from vehicles equipped with spark ignition engines. To meet the established standards for limiting hydrocarbon emissions caused by evaporation, all modern vehicles use fuel vapor recovery systems, the optimal parameters of which require the availability and application of mathematical models and methods for their determination.The purpose of the research was to develop a model of vapor generation processes in the car fuel tank and a methodology for determining the main quantitative parameters of the vapor-air mixture.Methodology and research methods. The analysis of the processes of vapor generation in the fuel tank was carried out. It was shown that the mass of hydrocarbons generated in the steam space was directly proportional to its volume and did not depend on the amount of fuel in the tank.Scientific novelty and results. New analytical dependences of the vaporization amount on the saturated vapor pressure, barometric pressure, initial fuel temperature and fuel heating during parking have been obtained.Practical significance. A formula was obtained to estimate the temperature of gasoline boiling starting in the tank, depending on the altitude above sea level and the volatility of gasoline, determined by the pressure of saturated vapors. Using the new equations, the vaporization analysis in real situations (parking, idling, refueling, explosive concentration of vapors) was carried out.


2014 ◽  
Vol 568-570 ◽  
pp. 137-140
Author(s):  
Yan Cai ◽  
Gui Ping Lin

There are several oxygen concentration measurement methods applied in aircraft fuel tank inerting systems. In this work, an aircraft fuel tank inerting experiment system was built and oxygen concentration of the fuel tank ullage (fuel tank space above the surface of the fuel which is filled with fuel vapor and air) and the dissolved oxygen in the fuel was detected with the methods of light absorption and optical fluorescence. The experiment was conducted through different operating conditions and results has illustrated that the light absorption method as well as the optical fluorescence method has the same accuracy sensing calibration gases, but the suitable condition of the two methods are different. Results have shown that the method of light absorption is more suitable to test oxygen concentration of gas mixture, and the method of optical fluorescence is more suitable to detect the concentration of dissolved oxygen in liquid substance.


Energies ◽  
2019 ◽  
Vol 12 (4) ◽  
pp. 704 ◽  
Author(s):  
Chien-Hsun Wu ◽  
Cheng-Ta Chung ◽  
Wei-Chen Lin ◽  
You-Ya Lin

This paper aims at the development of a novel onboard refueling vapor recovery (ORVR) system for scooters. The corresponding feasibility and evaporative emission are evaluated so that this preliminary study may offer important contributions for developing an effective ORVR system in Taiwan. A survey of research is initially conducted to compare the evaporative emission of the ORVR systems mounted on vehicles with that of the vapor recovery systems of Stage II installed at gas stations. The results show that the ORVR technology possesses better controllability and lower cost. Then, a novel ORVR system for scooters consisting of a self-made fuel tank, a self-made carbon canister, a vapor pipe, a fuel limit vent valve, and a surge protector etc. is developed and tested. The proposed self-made carbon canister possesses the storage capacity of fuel vapor large enough to perform the adsorption tests of diurnal and hot soak for as long as three consecutive days. Finally, the designed ORVR system is installed on a scooter and tested for evaporative emission under the regulation of Taiwan so as to check if it fulfills the requirements. The results are further compared with those with the evaporative emission control system (EVAP). A significant improvement on the leaking problem of fuel vapor is gained by using the proposed ORVR system. Consequently, the study can offer a valuable reference for developing an economical and effective ORVR system in the future.


Author(s):  
Emma Frosina ◽  
Adolfo Senatore ◽  
Assunta Andreozzi ◽  
Gianluca Marinaro ◽  
Dario Buono ◽  
...  

This paper is focused on the study of the sloshing in the fuel tank of vehicles. As well known, fluid dynamic in an automotive fuel tank have to be studied and optimized to allow the correct fuel suction in all driving conditions, prevent undesired slosh noise and limit its influence on fuel vapor formation and management. Experimentation to predict the sloshing with a good accuracy depends on the ability to replace real working parameters and conditions like accelerations, decelerations, slope variations and rotations. This paper shows results obtained studying the sloshing inside a reference tank with computational fluid-dynamic and experimental approaches. The test bench for automotive fuel tank, employed in this analysis, has been designed by Moog Inc. on specification from Fiat Chrysler Automobiles and it is aimed at covering the wider possible range of dynamic conditions. It basically consists of a hexapod, which uses six independent actuators arranged in three triangles and connecting a base and a top platform, thus allowing all six DOFs. Above the top platform is mounted a tilt table with two additional actuators, to extend pitch and roll envelope, thus the name of “8-DOF bench”. A dedicated CFD model has been built up using a CFD commercial code. The model has been integrated with the multiphase tool in order to correctly reply the real free surface. Results, numerical and experimental, have been post-processed with Matlab® comparing percentage gaps of the free surfaces each other. The comparison has shown a good agreement. This research is the result of a scientific collaboration between the Industrial Engineering Department of University of Naples Federico II and FCA Fiat Chrysler Automobiles.


Author(s):  
Donna J. Michalek ◽  
Krista L. Stalsberg-Zarling ◽  
Lawrence W. Evers

Recently, additional scrutiny is being placed on all vapor releases to the environment from the fuel system of an automobile. In an effort to lower the overall release of fuel vapor, a preliminary study of the vapor formation processes that occur in a low pressure supply fuel rail was undertaken. The first objective of this work was to determine the means by which fuel vapor is generated within the fuel rail, particularly during hot soak conditions. Then, using this information, the next task was to develop a computational fluid dynamics (CFD) code which would model the vapor formation in the rail. An investigation of the fuel rail material and design revealed that the probable mechanism for vapor formation is nucleate boiling from cavities in the fuel rail surface and at the o-ring connections with the fuel injectors. Therefore, an experiment was constructed to investigate the vapor formation from artificial cavities on a metallic surface and at an o-ring interface. The data collected from the experiment included the departure diameter of the vapor bubbles, the bubble frequency, and the bubble rise velocity. These values, which are used to determine the vapor generation rate, were compared to the results predicted by various correlations available in the literature. Subsequently, a CFD model was constructed of the fuel rail, using Star-CD, by incorporating the appropriate vapor generation correlations as user-defined subroutines. The experimental observations clearly demonstrated that a large amount of vapor was generated at the o-ring interface and, to a lesser degree, from the cavities in the metallic surface. A CFD model was constructed to predict the vapor generated in a fuel rail from these cavities. Existing correlations that describe nucleate boiling adequately model this generation mechanism in the fuel rail. This CFD code can be used to determine the amount of vapor formed under various hot soak conditions. An analytical means of predicting the vapor formation at the o-ring interface will have to be developed in order to complete the CFD model.


1975 ◽  
Vol 26 (2) ◽  
pp. 165-171 ◽  
Author(s):  
A. B. Reynolds ◽  
C. A. Erdman ◽  
M. Kirbiyik
Keyword(s):  

Author(s):  
Luca Romagnuolo ◽  
Emma Frosina ◽  
Assunta Andreozzi ◽  
Adolfo Senatore ◽  
Francesco Fortunato ◽  
...  

Abstract Vehicle evaporative emission is one of the most important sources of pollution from a gasoline-fueled vehicle. Since international regulations on Volatile Organic Compounds (VOC) emission are becoming increasingly stringent every year, the study of the VOC generation has become of fundamental importance. It is known that VOC generation is particularly high during the refueling phase: fresh fuel coming from the refueling nozzle impacts on the filling pipe wall and it is a source for sloshing in the fuel tank. Fuel vapor generated can be collected by a vapor recovery nozzle and stored in the gas station tank (Stage II vapor recovery system, European normative) or trapped by the vehicle carbon canister (On-board Refueling Vapor Recovery system, U.S. normative). In this activity, an automotive gasoline fuel tank for U.S. applications has been used for both experimental and numerical analyses, provided by FCA. Experiments were performed in FCA laboratories, in a sealed and thermal controlled environment (mini-SHED): vapor flow exiting the fuel tank during refueling has been measured, and fuel vapor mass has been evaluated by dynamically measuring the weight variation of a carbon canister filter connected to the fuel tank vent system. A CFD model was built based on CAD geometries provided by FCA, and numerical analysis of the refueling process has then been executed by using a commercial 3D CFD software. Results were then compared with experimental data. This activity is a part of a collaboration between University of Naples Federico II and FCA Italy about fuel vapor emissions control and prediction.


1966 ◽  
Vol 39 (4) ◽  
pp. 1200-1214
Author(s):  
W. F. Anspach

Abstract Supersonic aircraft in the Mach 3 range have increased temperature requirements for many materials of construction. One of the most critical problem areas is the integral fuel tank where state-of-the-art elastomeric sealants no longer meet those requirements. New sealants resistant to hydrocarbon fuels at temperatures in excess of 500° F are urgently needed. A high temperature integral fuel tank filleting sealant has been developed based on a mixture of high and low molecular weight hydrofluoroearbon polymers. This sealant has a solids content of 85 per cent and cures at modest temperatures. It is a one component system stable for several weeks at ambient temperatures and for longer periods if refrigerated. The sealant exhibits good room temperature and high temperature mechanical properties both before and after aging in hydrocarbon fuel and fuel vapor at temperatures up to 500° F. A typical formulation showed an increase in tensile strength and better than 50 per cent retention of elongation after 1000 continuous hours exposure to fuel vapor at 500° F. Adhesion to metal substrates is good and samples have resisted rupture and loss of adhesion when pressurized at 500° F for 1000 hours. This is only an interim solution to the critical fuel tank sealant problem in Mach 3 aircraft. Research is continuing to improve its useable life and to eliminate a possibly serious corrosion problem with titanium substrates. It must be emphasized, however, that sealants based on hydrofluorocarbons, fluorosilicones, and other available elastomers can at best provide interim solutions to the high temperature sealant problems and that new base polymers, such as the triazine and polyether elastomers currently being developed by the Air Force Materials Laboratory, are needed to provide sealants which completely meet requirements.


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