Thermal Performance Analysis on shell-and-tube heat exchangers by Utilizing Liquid Carbon Dioxide for Mine Cooling

ABSTRACT

Liquid carbon dioxide (LCO₂) shows great potential in mitigating heat damage in high-temperature mines. To address cooling needs of mine working faces, a shell-and-tube heat exchanger utilizing LCO₂ was designed and relevant performance parameters were analyzed. After analyzing 290 sets of experimental data, we compared 7 heat transfer models and pressure drop correlations for predicting CO₂ two-phase flow, among which the lowest prediction errors are 23.7% and 18.8%, respectively. By adapting variable thermal properties of LCO₂ from NIST (National Institute of Standards and Technology), the appropriate parameter size for the heat exchanger has been obtained through detailed iterative solutions. The various influencing factors were investigated as well. The results show that increasing the outside diameter from 9 mm to 10 mm and decreasing the baffle spacing from 140 mm to 100 mm significantly improves the heat transfer performance. However, the inner diameter and the mass flow rate have a greater impact on pressure drop than heat transfer, with final pressure drops of 5.9 kPa, 12.1 kPa, and 27.1 kPa, respectively. This work can serve as a foundation for further investigations on CO₂ utilization and provide technical guidance for the design of LCO₂ shell-and-tube heat exchangers.

KEYWORDS:

• LCO₂
• Two-phase flow
• Heat transfer
• Pressure drop
• Heat exchanger

Acknowledgements

This work was supported by the National Natural Science Foundation of China (51806235). The corresponding author is grateful to the China Scholarship Council for funding his oversea study (202006425010).

Disclosure statement

No potential conflict of interest was reported by the authors.