Abstract
The leakage research on supercritical carbon dioxide fluid in rolling piston expander was investigated experimentally. Using expander instead of throttle valve is an important way to improve the efficiency of carbon dioxide refrigeration system. However, the supercritical fluid leakage in expander is serious and is the main factor affecting the expander’s efficiency. This paper presented and compared four classic leakage models. The analysis indicated that laminar leakage model is suitable in leakage simulation of expander. A leakage test system, including the leakage test part which has two types of leakage specimens with different gaps ranging from 5 to 15 μm, was established. The experimental results indicated that lubricant film played an important role. When the leakage clearance of cylindrical specimen was 5 μm, the mass flow rate of leakage was about 0.88 g s−1. The data was 3.638 g s−1 with leakage clearance being 10 μm and 7.11g s−1 with leakage clearance being 15 μm. A modified leakage model was developed, whose average deviation was within 10% compared with the experimental data. At last, this paper simulated the leakage in rolling piston expander presented by Tian et al. (2010). The leakage between rolling piston and cylinder was the most serious part with the value up to 0.04 kg s−1.
Similar content being viewed by others
References
European Union. Regulation (EC) No 842/2006 of the European Parliament and of the Council. Official Journal of the European Union, 2006, L161/1-10
European Union. Relating to emissions from air-conditioning systems in motor vehicles and amending Council Directive 70/156/EEC. Official Journal of the European Union. 2006, L161/12–18
Calm J M. Options and outlook for chiller refrigerants. Int J Refrig, 2002, 25(6): 705–715
Lorentzen G. The use of natural refrigerants: a complete solution to the CFC/HCFC predicament. Int J Refrig, 1995, 18(3):190–197
Tamura I, Taniguchi H, Sasaki H, et al. An analytical investigation of high-temperature heat pump system with screw compressor and screw expander for power recovery. Energy Convers Manage, 1997, 38: 1007–1013
Lorenzo C, Yunho H, Reinhard R. Experimental Investigation of Oil Retention in Air Conditioning Systems. Int J Refrig, 2005, 28(7): 1018–1028
Robinson D M, Groll E A. Efficiencies of trans-critical CO2 cycles with and without an expansion turbine. Int J Refrig, 1998, 21(7): 577–589
Ma Y T, Wang K H, Yang Z, et al. Thermodynamic analysis of CO2 transcritical contrary cycle with an expander (in Chinese). J Eng Thermophys, 1999, 20(6): 661–665
Yang J L, Ma Y T. Exergy analysis of transcritical carbon dioxide refrigeration cycle with an expander. Energy, 2005, 30(7): 1162–1175
Yang J L, Ma Y T, Li M X, et al. Simulation and experimental study for transcritical CO2 heat pump system with expander (in Chinese). J Tianjin Univ, 2007, 40(9): 1099–1104
Li M X, Ma Y T, Tian H. A rolling piston-type two-phase expander in the transcritical CO2 cycle. HVAC&R Research, 2009, 15(4): 729–741
Fukuta M, Yanagisawa T, Higashiyama M, et al. Performance of vane-type CO2 expander and characteristics of transcritical expansion process. HVAC&R Research J, 2009, 15(4): 711–727
Guan H Q, Ma Y T, Li M X, et al. Efficiency analysis on carbon dioxide reciprocating expander (in Chinese). Refrig Air-cond, 2004, 4(6): 35–38
Fukuta M, Adachi M, Yanagisawa T, et al. Trans-critical leakage flow in CO2 expander. In: International Symposium on Next-Generation Air Conditioning and Refrigeration Technology, Tokyo, 2010. 17–19
Fukuta M, Yanagisawa T, Shimizu T, et al. Flow characteristics of refrigerant-oil mixture through narrow clearance (in Japanese). Trans JSRAE, 1996, (13): 175–186
Xing Z W, Peng X Y. Leakage characteristics in twin screw compressor with refrigerant R134a (in Chinese). J Refrig, 2000, 4: 23–28
Xing Z W. Theory of Screw Compressor for Designed and Application (in Chinese). Beijing: China Machine Press, 2001
Sun F T, Ma Y T, Li M X, et al. The effect of lubricant on system of carbon dioxide transcritical cycle with expander. J Eng Thermophys, 2007, 28: 369–372
Ma G Y, Li H Q. Rotary Compressor (in Chinese). Beijing: China Machine Press, 2003
Incropera F P, Dewitt D P. Fundamentals of Heat and Mass Transfer, New York: John Wiley, 2001
Tian H, Ma Y T, Li M X, et al. Study on expansion power recovery in CO2 trans-critical cycle. Energy Conversion Manage, 2010, 51: 2516–2522
Sun F T. Theoretical and experimental research on cooling heat transfer of supercritical CO2-lubricant oil mixture (in Chinese). Doctoral Dissertation. Tianjin: Tianjin University, 2007
Zhang P S, Lu S C. Elastohydrodynamic Lubrication and Its Application (in Chinese). Beijing: Higher Education Press, 1995
Tong J S. The Application and Theory of Molecular Aggregation (in Chinese). Beijing: Science Press, 1999
Author information
Authors and Affiliations
Corresponding author
Rights and permissions
About this article
Cite this article
Tian, H., Ma, Y., Li, M. et al. Leakage research on supercritical carbon dioxide fluid in rolling piston expander. Sci. China Technol. Sci. 55, 1711–1718 (2012). https://doi.org/10.1007/s11431-012-4831-8
Received:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s11431-012-4831-8