CO2 has perfect environmental properties and has great potential to become a very ideal working fluid for power cycle. In the laboratory, a CO2 transcritical power cycle system was established, using a rolling piston expander. Experimental study was carried out on the operating parameters, the electric power generated and the thermal efficiency. The pump operating speed and the load resistance were used to regulate the operating parameters. The results showed that there was a sudden decrease for the electric power generated in the start-up process. The electric power rose with increasing the converter frequency. When the converter frequency kept constant, the electric current declined with increasing the load resistance. In the experimental study, the steady electric power generated could reach about 1100 W and the thermal efficiency 5.0% when the high pressure was about 11 MPa and the low pressure was about 4.6 MPa. Though the isentropic efficiency, about 21.4%, was unsatisfactory, it still has important significance for the study on CO2 expander.

http://dx.doi.org/10.1016/j.energy.2015.11.074

Project 51306198 supported by National Natural Science Foundation of China and the Instrument Developing Project of the Chinese Academy of Sciences (Grant No. YZ200830) are gratefully acknowledged. Prof. Yitai Ma and Dr. Hua Tian in Tianjin University, as well as Mr. Honglu Qu (Chinese Academy of Sciences) and Minghai Tu (Tianjin University) are very helpful for supporting the design and successful running of experimental system.

Pan LS,Li B,Wei XL,et al. Experimental investigation on the CO2 transcritical power cycle[J]. ENERGY,2016,95:247-254.