Optimal design of the structure and settings of nuclear HTR thermodynamic cycles

A thermal integration method has been used by Framatome-ANP since 2001 in order to optimize thermodynamic cycles (cogeneration and combined cycles) coupled to new nuclear high temperature reactors. This method allows the design of complex thermodynamic cycles that comply to a large number of industrial constraints, without any a priori assumption on the structure of the internal heat exchanger network. This paper briefly recalls the principles of the method and shows how accurate and rigorous exergy analyses can be carried out quite easily in an industrial context. It details on an example how industrial constraints and thermodynamical considerations interact to lead to an optimal cycle structure and settings. The efficiencies obtained are presented and discussed. In particular we discuss what we mean by optimal design. It is shown that this method is well suited to build optimal complex heat exchanger networks. The differences with other methods like the thermoeconomic ones are also briefly discussed.