Experimental investigation on the internal working process of a CO2 rotary vane expander

Simulation and experiment research on wide ranging working process of scroll expander driven by compressed air

“…The volumetric efficiency increases from 0.59 to 0.69 at the rotating speed of 1140e2820 rpm and the maximum errors is 2.0%. The high volumetric efficiency is an advantage of scroll expander comparing with the other types, such as the rotary vane expander [19]. Although the tested volumetric is higher somewhat than the one in the previous report [8], the performance also has the scope for improvement.…”

Improved rotary vane expander for trans-critical CO2 cycle by introducing high-pressure gas into the vane slots

“…Fukuta and Yanagisawa (2003) investigated this kind of expander for the trans-critical CO 2 cycle through his mathematical model and found that the leakage in the expander had a dominant influence on the performance. Yang et al (2006Yang et al ( , 2008a and Jia et al (2009) have also been investigating the rotary vane expander since 2003, and a double acting rotary vane expander prototype has been developed and validated to have a stable operation in the CO 2 refrigeration system. However, serious leakage within the expander was observed and the tested volumetric efficiency and isentropic efficiency for the original prototype were less than 17% and 15%, respectively.…”

“…The suction pressure could only reach 6.6 MPa while the lowest discharge pressure was 5.2 MPa, which meant the working conditions did not fall into the super-critical region. The authors had investigated this problem in previous work (Yang et al, 2008a) and found that the loss of contact between the vane tip and cylinder wall was the major reason for the serious leakage in the original expander. Since then, improving the contact between the vane tip and cylinder wall has been the main approach for improving the expander performance.…”

Expanders for micro-CHP systems with organic Rankine cycle

“…Compared with other expander concepts, the rotary vane expander has simpler structure, easier manufacturing and lower cost [22]. Air motors are not designed to hold organic working fluids and hence leaking of ORC fluids is inevitable if they are used as expanders without proper modifications, because most turbines are designed for only one specific working fluid and a very narrow operating range [14].…”