S.Yu. Belousova, Lead Engineer Ya. G. Osadchiy, Dr. Sci. (Eng.), General Director ZAO NPP Mashtest, Moscow, Russia V.S. Zarubin, Dr. Sci. (Eng.), Prof., email@example.com MGTU in the Name of N.E. Bauman, Moscow, Russia V.M. Frum, General Director OOO NPF Real-Shtorm, Izhevsk, Russia
When using compressed natural gas as a fuel in the automobile engines, there is a potential danger of this gas pressuire increase up to the specified working pressure in the pre-filled cylinders. This pressure increase is caused by an increase in the ambient temperature compared to the temperature of the compressed natural gas corresponding to the completion of the filling process. If after cylinder filling before methane consumption there will be rather long pause, during which the ambient temperature rises, the pressure in the cylinder may exceed the permissible operating value, cause the reduction of the residual life and eventually lead to the destruction of the cylinder with the subsequent ignition of compressed natural gas.
To obtain quantitative estimates of possible pressure increase of the compressed natural gas in the automobile cylinder caused by ambient temperature increase, it is required to use up-to-date methods of mathematical simulation. Reliability of such estimates characterizing the permissible temperature regimes of operation of the filled automobile cylinders with compressed natural gas is determined by the adequacy of the mathematical model describing the thermal processes in the typical cylinders with compressed natural gas during their filling and subsequent storage. One of the main elements of such a model is the dependence, which is in a good agreement with the experimental data, between the main parameters describing the compressed natural gas state in the cylinder. As such parameters for any gas its pressure, temperature and density are normally used, which are specified in the equation of the given gas state.
When building the mathematical model the option of the equation related to the methane state is utilized, which is the main part of the compressed natural gas commonly used in the motor transport. This option establishes the dependence between the pressure, temperature and methane density confirmed experimentally within the accuracy of a tenth of one percent. Used at quantitative analysis models related to dependence of heating capacity, viscosity, thermal conductivity and volumetric expansion of the methane on its temperature and density are also in a good agreement with the experimental data.
1. GOST R 51753—2001. High pressure cylinders for compressed natural gas used as motor fuel for motor vehicles. General specifications. Available at: http://docs.cntd.ru/document/1200012999 (accessed: May 4, 2018). (In Russ.).
2. RD 03112194-1095—03. Guidance on the organization of operation of gas-cylinder vehicles operating on compressed natural gas. Available at: http://docs.cntd.ru/document/1200034846 (accessed: May 4, 2018). (In Russ.).
3. Aliev A.V., Mishchenkova O.V. Mathematical simulation in engineering. Moscow-Izhevsk: Institut kompyuternykh issledovaniy, 2012. 476 p. (In Russ.).
4. Zarubin V.S. Simulation. Moscow: Izdatelskiy tsentr «Akademiya», 2013. 336 p. (In Russ.).
5. Viktorova V.S., Stepanyants A.S. Models and methods for calculating the reliability of technical systems. Moscow: Lenand, 2016. 256 p. (In Russ.).
6. Prokhorov A.M. Physical encyclopedic dictionary. Moscow: Sovetskaya entsiklopediya, 1983. 928 p. (In Russ.).
7. Malkova M.P. Reference book on physical and technical basics of cryogenics. Moscow: Energoatomizdat, 1985. 432 p. (In Russ.).
8. Grigoreva I.S., Meylikhova E.Z. Physical values: Reference book. Moscow: Energoatomizdat, 1991. 1232 p. (In Russ.).
9. Aleksandrova A.A., Markova V.A. Alternative fuels for internal combustion engines. Moscow: OOO NITs «Inzhener», OOO «Oniko-M», 2012. 790 p. (In Russ.).
10. Setzmann U., Wagner W. A new equation of state and tables of thermodynamic properties for methane covering the range from melting line to 625 K at pressures up to 100 MPa. Journal of Physical and Chemical Reference Data. 1991. Vol. 20. № 6. pp. 1061–1155.
11. Belousova S.Yu., Zarubin V.S., Osadchiy Ya.G. Mathematical model of thermal processes in the automobile cylinders with methane. Transport na alternativnom toplive = Transport on Alternative Fuel. 2014. № 4. pp. 5–13. (In Russ.).
12. Cristancho D.E., Mantilla I.D., Ejaz S., Hall K.R. Accurate p—p—T Data for Methane from (300 to 450) K up to 180 Mpa. Journal Chemical and Engineering Data. 2010. Vol. 55. № 2. pp. 826–829. DOI: 10.1021/je9004849
13. Zhu X., Zhao Ya-Pu. Atomic Mechanisms and Equation of State of Methane Adsorption in Carbon Nanopores. Journal of Physical Chemistry C. 2014. Vol. 118. № 31. pp. 17737–17744. DOI: 10.1021/jp5047003
14. Tibaduiza A., Cristancho D.E., Ramirez H.A. Accurate p—p—T Data for a Synthetic Residual Natural Gas Mixture (0.95 CH4 + 0.04 C2H6 + 0.01 C3H8) at Temperatures between (135 and 500) K at Pressures to 200 Mpa. Journal Chemical and Engineering Data. 2016. Vol. 61. № 8. P. 2771–2781. DOI: 10.1021/acs.jced.6b00137
15. Ahmadi P., Chapoy A., Tohidi B. Density, speed of sound and derived thermodynamic properties of a synthetic natural gas. Journal of Natural Gas Science and Engineering. 2017. Vol. 40. № 2. pp. 249–266.
16. Belousova S.Yu., Krylov E.N., Osadchiy Ya.G., Zarubin V.S.Thermal processes in the automobile cylinders with methane during filling and emptying. Bezopasnost truda v promyshlennosti = Occupational Safety in Industry. 2017. № 4. pp. 68–77. DOI: 10.24000/0409-2961-2017-4-68-77. (In Russ.).
17. Leonteva A.I.Theory of heat and mass transfer. Moscow: Izd-vo MGTU im. N.E. Baumana, 1997. 683 p. (In Russ.).