Abstract
In this article, the performance improvement of supercritical carbon dioxide (sCO(2)) Brayton cycles through heat recovery and advanced heat exchanger (HX) design is reviewed. The configuration of sCO(2) cycles and the bottleneck of the design of an efficient sCO(2) cycle is first evaluated. It was found that heat rejected in the precooler is a large waste that could potentially enhance the overall sCO(2) system performance. Then integration of the absorption cycle, organic Rankine cycle, and thermal desalination plant to the sCO(2) cycle to recover the waste thermal energy is reviewed and discussed. Results showed that these bottoming heat recovery cycles could substantially improve the overall sCO(2) system efficiency. The combined system of sCO(2)/absorption chiller, sCO(2)/ORC increases the cycle efficiency to about 78% and 79%, respectively. Also, a combined system of sCO(2)/desalination produces about 200 000 m(3)/day with a cost of less than $1.0/m(3). Based on the review, the evaluation criteria are proposed for decision-makers. Another bottleneck of the design of the sCO(2) system is the HXs (recuperators) used in the sCO(2) cycle which are relatively large and negatively affect the cycle compactness and performance. Therefore, various types of recuperators proposed and designed for sCO(2) cycles are reviewed and evaluated. This review highlights the need for further research to enhance heat recovery, reduce the cost of bottoming cycles, and improve the design of HXs.