Search

This paper presents the model of heat exchanger dedicated to operate in supercritical CO2 cycles (Brayton). The models is built in the EBSILON software and validated against literature available experimental data. Relatively compact design of the supercritical CO2 cycle elements required using radial turbomachinery and thin plate heat exchangers. Thus, it seems that there is no general relationships for the turbomachinery and real characteristics need to be used for constructing the models. [ABSTRACT FROM AUTHOR]

This paper presents the model of heat exchanger dedicated to operate in supercritical CO2 cycles (Brayton). The models is built in the Ebsilon software and validated against literature available experimental data. Relatively compact design of the supercritical CO2 cycle elements required using radial turbomachinery and thin plate heat exchangers. Thus, it seems that there is no general relationships for the turbomachinery and real characteristics need to be used for constructing the models. [ABSTRACT FROM AUTHOR]

Since carbon dioxide used as a working fluid in both supercritical and transcritical power cycles operates mostly in the supercritical area, the ideal gas model cannot be applied to obtain the working parameters and the cycle performance. In this paper some equations of state and their modifications that are usually recommended in the literature are presented. In the high-precision equations the maximum relative error can reach approximately 20% in the near critical region. That is why some of the authors using corrections. The corrected equations can precisely predict the density of supercritical CO2, and the average relative error can be restricted to within 1.5%. The Lee-Kesler equation of state is recommended for further calculations owing to its good performance and availability in the software application to design a supercritical CO2 cycle. [ABSTRACT FROM AUTHOR]

In this paper, a supercritical CO2 cycle concept is investigated in terms of possible use as a power conversion cycle. Three types of most popular modifications of simple Brayton cycle (pre-compression, partial cooling and recompression) are described. As the most efficient, a recompression cycle was chosen for further investigation. The model of the recompression supercritical carbon dioxide Brayton cycle was created using GateCycle software. The results of simulation performed in GateCycle software show that the cycle achieves efficiency of 44% for CO2 turbine inlet conditions of 550°C and 20 MPa. Comparison of optimum turbine inlet pressure for cycle efficiency and net output power at turbine inlet is presented. [ABSTRACT FROM AUTHOR]