Flowsheet Study of a Multistage Flash Desalination System for Cogeneration With High Temperature Gas-Cooled Reactor

High temperature gas-cooled reactor (HTGR) produces not only electricity but also high temperature heat for a variety of heat applications. In the Middle East countries, large demand exists for cogeneration of pure water and electricity from desalination plant coupling with power station. Desalination with an HTGR direct cycle gas turbine system can efficiently meet this demand because such system can produce pure water from using only the waste heat of power generation via secondary pressurized water loop. The waste heat of up to 248MWt is available for desalination from the reactor system of 600 MWt thermal power. In this paper, heat and mass balance was calculated for a new concept of desalination system which is shown to increase use of waste heat by incrementing the number of thermal loading steps at the heat recovery section. Calculation is performed at steady water production condition to clarify the optimum steps of incremental loading based on engineering considerations. As the result, it was found that heat transfer area of heat recovery section in case of brine heater number 3 was 28% smaller than that of number 2.