A novel organic thermodynamic cycle on the use of gravity for pressurization

Li, Jing; Pei, Gang; Ji, Jie

Abstract

Compared with water pump used in the steam Rankine cycle, pump for the organic Rankine cycle (ORC) has several disadvantages such as great difficulty in manufacture, low efficiency, easily-invited cavitation and high cost. A novel organic fluid thermodynamic cycle is proposed in this paper for heat to power conversion. Instead of pumping, the liquid from the condenser is pressurized due to gravity acting. Three kinds of dry fluids, R113, R123 and R245fa, are used to analyze the cycle performance on different evaporation and condensation conditions. The ORC pump is also tested. Based on the practical pumping efficiency, performances of the proposed thermodynamic cycle and the ORC cycle are compared. The results indicate that the height difference required for pressurization of working fluid in the gravity field is lower when high boiling point and liquid density fluid is used. On the condition of evaporation temperature of 100°C and condensation temperature of 50°C, the required height difference and the cycle power efficiency for R113 are 22.2 m and 8.1%, respectively. And the efficiency of the proposed cycle is higher than that of pump-assisted ORC cycle by 0.8%. The proposed thermodynamic cycle underscores its potential for combined heat and power generation.

Citation

Li, J., Pei, G., & Ji, J. (2012). A novel organic thermodynamic cycle on the use of gravity for pressurization. Kung Cheng Je Wu Li Hsueh Pao/Journal of Engineering Thermophysics, 33(5), 729-734

• Journal Article Type: Article
• Publication Date: May 1, 2012
• Deposit Date: Mar 24, 2022
• Journal: Kung Cheng Je Wu Li Hsueh Pao/Journal of Engineering Thermophysics
• Print ISSN: 0253-231X
• Peer Reviewed: Peer Reviewed
• Volume: 33
• Issue: 5
• Pages: 729-734
• Public URL: https://hull-repository.worktribe.com/output/3647564
• Publisher URL: No URL available