SCI和EI收录∣中国化工学会会刊

中国化学工程学报 ›› 2023, Vol. 61 ›› Issue (9): 180-191.DOI: 10.1016/j.cjche.2023.02.008

• Full Length Article • 上一篇    下一篇

Numerical study of the deep removal of R134a from non-condensable gas mixture by cryogenic condensation and de-sublimation

Hongbo Tan, Boshi Shao, Na Wen   

  1. Department of Refrigeration and Cryogenic Engineering, School of Energy and Power Engineering, Xi ’an Jiaotong University, Xi’an 710049, China
  • 收稿日期:2022-09-22 修回日期:2023-02-13 出版日期:2023-09-28 发布日期:2023-12-14
  • 通讯作者: Hongbo Tan,E-mail:hongbotan@xjtu.edu.cn;Boshi Shao,E-mail:shaobs1998@stu.xjtu.edu.cn
  • 基金资助:
    The work was funded by the National Natural Science Foundation of China (52076159).

Numerical study of the deep removal of R134a from non-condensable gas mixture by cryogenic condensation and de-sublimation

Hongbo Tan, Boshi Shao, Na Wen   

  1. Department of Refrigeration and Cryogenic Engineering, School of Energy and Power Engineering, Xi ’an Jiaotong University, Xi’an 710049, China
  • Received:2022-09-22 Revised:2023-02-13 Online:2023-09-28 Published:2023-12-14
  • Contact: Hongbo Tan,E-mail:hongbotan@xjtu.edu.cn;Boshi Shao,E-mail:shaobs1998@stu.xjtu.edu.cn
  • Supported by:
    The work was funded by the National Natural Science Foundation of China (52076159).

摘要: Nowadays, the limits on greenhouse gas emissions are becoming increasingly stringent. In present research, a two-dimensional numerical model was established to simulate the deep removal of 1,1,1,2-tetrafluoroethane (R134a) from the non-condensable gas (NCG) mixture by cryogenic condensation and de-sublimation. The wall condensation method was compiled into the Fluent software to calculate the condensation of R134a from the gas mixture. Besides, the saturated thermodynamic properties of R134a under its triple point were extrapolated by the equation of state. The simulation of the steam condensation with NCG was conducted to verify the validity of the model, the results matched well with the experimental data. Subsequently, the condensation characteristics of R134a with NCG and the thermodynamic parameters affecting condensation were studied. The results show that the section with relatively higher removal efficiency is usually near the inlet. The cold wall temperature has a great influence on the R134a removal performance, e.g., a 15 K reduction of the wall temperature brings a reduction in the outlet R134a molar fraction by 85.43%. The effect of changing mass flow rate on R134a removal is mainly reflected at the outlet, where an increase in mass flow rate of 12.6% can aggravate the outlet molar fraction to 210.3% of the original. The research can provide a valuable reference for the simulation of the deep removal of various low-concentration gas using condensation and de-sublimation methods.

关键词: Numerical simulation, Greenhouse gas, Condensation, De-sublimation, Vapor deep removal, Non-condensable gas

Abstract: Nowadays, the limits on greenhouse gas emissions are becoming increasingly stringent. In present research, a two-dimensional numerical model was established to simulate the deep removal of 1,1,1,2-tetrafluoroethane (R134a) from the non-condensable gas (NCG) mixture by cryogenic condensation and de-sublimation. The wall condensation method was compiled into the Fluent software to calculate the condensation of R134a from the gas mixture. Besides, the saturated thermodynamic properties of R134a under its triple point were extrapolated by the equation of state. The simulation of the steam condensation with NCG was conducted to verify the validity of the model, the results matched well with the experimental data. Subsequently, the condensation characteristics of R134a with NCG and the thermodynamic parameters affecting condensation were studied. The results show that the section with relatively higher removal efficiency is usually near the inlet. The cold wall temperature has a great influence on the R134a removal performance, e.g., a 15 K reduction of the wall temperature brings a reduction in the outlet R134a molar fraction by 85.43%. The effect of changing mass flow rate on R134a removal is mainly reflected at the outlet, where an increase in mass flow rate of 12.6% can aggravate the outlet molar fraction to 210.3% of the original. The research can provide a valuable reference for the simulation of the deep removal of various low-concentration gas using condensation and de-sublimation methods.

Key words: Numerical simulation, Greenhouse gas, Condensation, De-sublimation, Vapor deep removal, Non-condensable gas