The Effect of Real Gas Approximations on S-CO2 Compressor Design

From the efforts of many researchers and engineers related to the S-CO2 Brayton cycle technology development, the S-CO2 Brayton cycle is now considered as one of the key power technologies for the future. Since the S-CO2 Brayton cycle has advantages in economics due to high efficiency and compactness of the system, various industries have been trying to develop baseline technology on the design and analysis of the S-CO2 Brayton cycle components. According to the previous researches on the S-CO2 Brayton cycle component technology, the treatment of a thermodynamic property near the critical point of CO2 is one of the main concerns since conventional design and analysis methodologies cannot be used for the near critical point region. Among many thermodynamic properties, the stagnation to static condition conversion process is important since the flow in a compressor is at high flow velocity. In this paper, the impact of various stagnation to static conversion methods on the S-CO2 compressor design near the critical point will be evaluated. From the evaluation, the limitation of a certain stagnation to static conversion method will be discussed to provide a guideline for the future S-CO2 compressor designers.