Generalized energy model of the open thermodynamic system “vehicle fuel tank”. Processes of non-stationary heat transfer with a variable fuel mass

Introduction (statement of the problem and relevance). While gasoline-powered vehicles generate a significant amount of hydrocarbons in the form of the fuel system emitted vapors, the main element of the system being the fuel tank, modern requirements for evaporative emission limits are significantly tightened. At the same time, the vaporization process parameters and the fuel vapor amount are determined by the dynamics of fuel heating in the tank under various modes of vehicle operation.

The purpose of the research was to develop a “vehicle fuel tank” energy model, seeking to create an open thermodynamic system which can exchange matter and energy with the environment depending on the variable amount of fuel in the tank.

Methodology and research methods. The analysis of heat flush connected to the fuel tank and taken away from it was being carried out. As a result of solving equations for open and closed thermodynamic systems, the parameters characterizing the thermal properties of the fuel tank were obtained.

Scientific novelty and results. Additional complex parameters have been proposed, the main of which are: heat transfer of the tank; tank heat capacity; supplied heat flux; the rate of heat capacity change; tank emptying time; fuel heating acceleration factor; the maximum rate of change in temperature difference. To assess the heat and power properties of the fuel tank, an additional parameter of the sphere surface area ratio to the surface area of the same volume tank has been proposed, which allowed estimating the fuel tank heat transfer to the environment.

Practical significance. Equations have been obtained that allow estimating the level of fuel temperature depending on the thermal properties and shape of the fuel tank in the absence and presence of fuel pump control.

1. Grigor’ev M.A., Zheltyakov V.T., Ter-Mkrtich’yan G.G., Terekhin A.N. [Modern vehicle engines and their prospects]. Avtomobil’naya promyshlennost’, 1996, no. 6, pp. 10–14. (In Russian)

2. Saykin A.M., Ter-Mkrtich’yan G.G., Karpukhin K.E., Pereladov A.S., Zhuravlev A.V., Yakunova E.A. [Ecological problems of modern transport vehicles including electromobiles]. Vestnik mashinostroeniya, 2017, no. 2, pp. 84–87. (In Russian)

3. Ter-Mkrtich’yan G.G. [Analysis of the vaporization processes in the vehicle fuel tank. New equation for determining the vapor amount]. Trudy NAMI, 2021, no. 2 (285), pp. 74–86. DOI: 10.51187/0135-3152-2021-2-74-86. (In Russian)

4. Ter-Mkrtich’yan G.G., Mikerin N.A., Glaviznin V.V., Balashov D.Yu., Arabyan M.E. [The thermodynamic system “fuel tank of a vehicle” energy model. Processes of unsteady heat transfer at constant fuel mass]. Trudy NAMI, 2020, no. 4 (283), pp. 82–93. DOI: 10.51187/0135-31522020-4-82-93. (In Russian)

5. Reddy S.R. Mathematical Models for Predicting Vehicle Refuelling Vapour Generation. SAE 2010 World Congress & Exhibition, 2010.

6. Liu H., Man H.Y., Tschantz M., Wu Y., He K.B., Hao J. M. VOC from vehicular evaporation emissions: status and control strategy. Environ. Sci. Technol, 2015, no. 49, pp. 14424–14431.

7. Itakura H., Kato N., Kohama T., Hyoudou Y., Murai T. Studies on Carbon Canester to Satisfy LEVII EVAP Regulations. SAE Technical Paper, 2000, 2000-01-0895. DOI: 10.4271/2000-01-0895.

8. Ntziachristos L., Gkatzofliasb D., Kouridis C., Samaras Z. COPERT: A European Road Transport Emission Inventory Model. Information Technologies in Environmental Engineering, 2009, pp. 491–504.

9. Mellios G., Samaras Z. An empirical model for estimating evaporative hydrocarbon emissions from canisterequipped vehicles. Fuel, 2007, no. 86, pp. 2254–2261.

10. Smith L., Hussain A., Pautasso E., Servetto E., Graziano E., Brown J. EVAP System Fluid-Dynamics and Chemistry Modelling for EMS Purge Control Development and Optimization. SIA Powertrain Conference, Versailles, 2015.

11. Zheng J., He H., Alimohammadi H. Three-dimensional Wadell roundness for particle angularity characterization of granular soils. Acta Geotechnica, 2021, no. 16, pp. 133–149. https://doi.org/10.1007/s11440-020-01004-9.

12. Hussain S. How to Calculate Sphericity. Available at: https://sciencing.com/calculate-sphericity-5143572.html (accessed 15 February 2022).