Studies on Carbon Dioxide Cycles for Power Generation : 3rd Report, Analysis with Approximate Equation of state of CO₂

抄録

Further improvements in thermal efficiency of steam and nuclear power plants are an important problem in the present energy crisis. Following the 1st and 2nd reports⁽¹⁾⁽²⁾, this paper presents a performance analysis of condensation cycles using carbon dioxide as a working fluid. The approximate equations of sufficient accuracy are derived for the enthalpy, the entropy, the mechanical works and cold end (minimum) enthalpy difference in regenerators in order to analyze CO₂ cycle performance. By utilizing these approximate equations, the performance characteristics of CO₂ condensation cycles with non-regenerator, 1-regenerator and 2-regenerator, and values of optimum reheat pressures have been analyzed and discussed. As a result, the effects of cycle parameters on the cycle performance can be expressed by an equation. This method makes it easier to understand the effect of each parameter on the CO₂ cycle performance owing to the expression by analytical equations than the direct calculation method from the data on the thermodynamic properties.