PRELIMINARY EXPERIMENTAL STUDY OF PRECOOLER IN SUPERCRITICAL CO2 BRAYTON CYCLE

Abstract

The supercritical carbon dioxide (S-CO2) Brayton power conversion cycle has been receiving worldwide attention because of high thermal efficiency due to relatively low compression work near the critical point (30.98℃, 7.38MPa) of CO2. The S-CO2 Brayton cycle can achieve high efficiency with simple cycle configuration at moderate turbine inlet temperature (450~650℃) and relatively high density of S-CO2 makes possible to design compact power conversion cycle. In order to achieve compact cycle layout, a highly compact heat exchanger such as printed circuit heat exchanger (PCHE) is widely used. Since, the cycle thermal efficiency is a strong function of the compressor inlet temperature in the S-CO2 power cycle, the research team at KAIST is focusing on the thermal hydraulic performance of the PCHE as a precooler. The investigation was performed by first developing a PCHE in-house design code named KAIST-HXD. This was followed by constructing the designed PCHE and testing it in the KAIST experimental facility, S-CO2PE. The test results of the PCHE were compared to the test results of a shell and tube type heat exchanger as well.