Supercritical carbon dioxide applications for energy conversion systems

In the present paper, the possibility of increasing the thermodynamic efficiency of an electric energy production plant, by using an advanced energy conversion system based on supercritical carbon dioxide (S-CO2) as working fluid, has been analyzed. Since the supercritical carbon dioxide cycles are being considered as a favorable candidate for the next generation of nuclear power plant energy conversion systems, a lead cooled fast reactor has been selected as reference in the present analyses. The main aim of the present study is to compare two different S-CO2 thermal cycles applied on the conversion system of a nuclear power plant. The reference Lead cooled Fast Reactor (LFR) used for the present analyses is the ALFRED reactor, which has a thermal power of 300 MW and it is considered the scaled down prototype of the industrial European Lead Fast Reactor (ELFR). Thermodynamic cycles selected for the present study are a Recompression Cycle and a Brayton Cycle with Regeneration. Each of them has been analyzed under several design conditions regarding the maximum pressure and the regeneration coefficient. Among different design conditions, the solution allowing the maximization of the overall efficiency has been identified. Thermodynamic analyses have been carried out with GateCycle™ v. 6.1.1, which is a General Electric software able to predict design and off-design performance of power plants

Supercritical carbon dioxide applications: features and advantages

The Supercritical carbon dioxide (SCO2) is widely used in many industrial applications as process or heat transfer fluid. The SCO2 is characterized by good chemical stability at high temperature, supercritical conditions at limited temperature and pressure and high thermodynamic efficiency. Because of these features, SCO2 allows to operate with small sized operating machines and higher efficiency compared to conventional applications. Moreover, the SCO2 can be used in conventional thermodynamic gas cycles reaching higher efficiency at the same temperature level. The main advantage is the possibility of reaching thermodynamic efficiency values close to 50%, much higher than conventional cycles. Moreover, the critical point of CO2, low pressure and low temperature (7 MPa and 300 K), makes systems more economic and technically feasible than systems powered by other supercritical fluids. SCO2 industrial applications are analyzed in the present paper and specific advantages will be investigated