Response of a Compact Recuperator to Thermal Transients in a Supercritical Carbon Dioxide Brayton Cycle

Abstract

Supercritical carbon dioxide (sCO2) power cycle designs are typically highly recuperated, transferring heat from the high temperature turbine exhaust stream to the compressor discharge stream thereby increasing overall cycle efficiency. Compact heat exchangers are preferred for this application due to their high surface area-to-volume ratio enabling much smaller heat exchangers as compared to conventional designs. However, compact heat exchangers have a higher metal density than conventional heat exchangers which could result in thermal lag during rapid temperature transients. The Naval Nuclear Laboratory has been operating the Integrated System Test (IST) with the objective of demonstrating the ability to operate and control an sCO2 Brayton power cycle over a wide range of conditions. Rapid turbomachinery startups and power transients result in thermal transients on the recuperator. This paper presents thermal transients observed in the IST recuperator during loop startup and power transients and illustrates the time to achieve thermal equilibrium following the transients.

Off-design and annual performance analysis of supercritical carbon dioxide cycle with thermal storage for CSP application

“…Tang et al [37]. used the Dittus-Boelter correlation for straight channel PCHE and validated the simulation results with experimental data published in Clementoni et al[38]. Jiang et al[39] proposed 0.809 as the Reynolds…”

Scalable Continuous Flow Metal–Organic Framework (MOF) Synthesis Using Supercritical CO2

“…Historically, continuous-flow scCO 2 processes focused on applications involving botanical extraction, coal gasification, and turbomachinery power cycles − – not on the synthesis of complex materials such as MOFs. Recently in a batch process, scCO 2 was used to synthesize MOFs, but in addition to being noncontinuous, the method also had long reaction times, ranging between 3 and 90 h .…”