Simulation and Real-World Investigation of the Vacuum Pumping Process for Liquid Nitrogen Vapour

We performed the required theoretical computations to simulate the process of pumping saturated liquid nitrogen vapours, accounting for the assumptions adopted. The paper provides a schematic of the test bench and describes the sequence of experiment stages. We checked whether the storage Dewar and volumetric vacuum pump were selected correctly so as to ensure the required evacuation level above the liquid nitrogen surface. We built our test bench and conducted an experiment involving thermostatting in the 63 to 77 K temperature range, and achieved a phase transition in the nitrogen, it turning from liquid to solid. We computed the mass of the nitrogen evaporated required to reach its triple point temperature. We calculated the effective evacuation rate in the system, taking into account the conductivity of separate components. We determined the minimum vapour evacuation time required. We plotted system temperature and pressure as functions of time. The paper describes possible modernisation of the experimental installation, that is, introducing additional crystallisation centres and monitoring the liquid nitrogen mass using electronic scales

References

[1] Malkov M.P., ed. Spravochnik po fiziko-tekhnicheskim osnovam kriogeniki [Handbook on cryogenics physical and technical fundamentals]. Moscow, Energoatomizdat Publ., 1985.

[2] Sychev V.V., Vasserman A.A., Kozlov A.D., et al. Termodinamicheskie svoystva azota [Thermodynamic properties of nitrogen]. Moscow, Izdatel’stvo standartov Publ., 1977.

[3] Levchenko A.V., Artem’yev O.G., Lavrov N.A., et al. Compensation of nitrogen losses in the atmosphere of hermetically closed habitable object. Khimicheskoe i neftegazovoe mashinostroenie [Chemical and Petroleum Engineering], 2018, no. 11, pp. 33--34 (in Russ.).

[4] Grezin A.K., Zinov’yev V.S. Mikrokriogennaya tekhnika [Microcryogenics]. Moscow, Mashinostroenie Publ., 1977.

[5] Song J.B., Kim K.L., Kim K.J., et al. The design, fabrication and testing of a cooling system using solid nitrogen for a resistive high-TC superconducting fault current limiter. Supercond. Sc. Technol., 2018, vol. 21, no. 2, art. 115023. DOI: https://doi.org/10.1088/0953-2048/21/11/115023

[6] Demikhov K.E., Panfilov Yu.V., eds. Vakuumnaya tekhnika [Vacuum technics]. Moscow, Mashinostroenie Publ., 2009.

[7] Barron R.F. Cryogenic systems. Oxford University Press, 1985.

[8] Журлова П.Ю., Губин М.В. Исследование процесса вакуумной откачки паров насыщенного азота с целью получения температур на уровне 63--77 K. Молодежный научно-технический вестник, 2016, № 2. URL: http://ainsnt.ru/doc/834165.html

[9] Frolov E.S., Minaychev V.S., eds. Vakuumnaya tekhnika [Vacuum techniques]. Moscow, Mashinostroenie Publ., 1985.

[10] Hoffman D., Singh B., Thomas III J.H. Handbook of vacuum science and technology. Academic Press, 1997.

[11] Rozanov L.N. Vakuumnaya tekhnika [Vacuum techniques]. Moscow, Vysshaya shkola Publ., 2007.

[12] Arkharov A.M., Arkharov I.A., Tychkova S.O. On problem of changing cryogenic liquids temperature at the pumping out and storing their vapors. Vestn. Mosk. Gos. Tekh. Univ. im. N.E. Baumana, Mashinostr. [Herald of the Bauman Moscow State Tech. Univ., Mechan. Eng.], 2010, no. S1, pp. 41--45 (in Russ.).

[13] Nikulin N.K., Anufriev I.I. [Experimental determination of gas amount adsorbed on the technological surfaces of pumped objects]. Sb. nauch. rabot 37y Mezhdunar. nauch. konf. Evraziyskogo Nauchnogo Ob"edineniya [Proc. 37th Int. Sc. Conf. Eurasian Scientific Association]. Moscow, ENO Publ., 2018, pp. 43--45 (in Russ.).

[14] Grigor’yev V.A., Pavlov Yu.M., Ametistov E.V. Kipenie kriogennykh zhidkostey [Boiling of cryogenic liquids]. Moscow, Energiya Publ., 1977.

[15] Samoylovich G.S. Gidrogazodinamika [Fluid dynamics]. Moscow, Mashinostroenie Publ., 1990.