Design and simulation of a process of seawater desalination (MED) using the residual heat of a PBMR nuclear power plant

In the present work it is demonstrated as the thermodynamic recuperative Brayton cycle with which operates a nuclear power plant type PBMR (Pebble Bed Modular Reactor) it allows to use the residual heat, removed in the coolers of the compression stage of the system, to produce vapor and to desalt seawater. The desalination process selected, starting from its operation characteristics and the derived advantages of them using nuclear heat, it the one of Multi-Effect Distillation, MED for its abbreviations in English, which described and it is justified to detail. This distillation process widely studied, allows us to use water vapor pressurized to temperatures between 70 and 110 C like energy source to evaporate the seawater in the first stage or effect of the process. The relatively low temperatures with which the vapor takes place of feeding to the process is it makes to the plant PBMR ideal for desalination of seawater, since does not require majors modifications to its design its operation, and on the contrary it allows to use the heat that previously was rejected, to produce the vapor. In this work an unit MED of six effects is designed, which undergoes a successive fall of pressure in each of them. Once obtained the agreed design to the conditions of operation of PBMR plant, it was model mathematically the MED process, including the coupling stage with the reactor coolers. The mathematical model was obtained by means of differential equations of mass balance and energy in the system, and with this it was implemented in SIMULINK a model equivalent to the MED process which is interconnected to the simulator coolers of the PBMR plant, constructed previously. One ran the program being obtained the results that are reported at the end of this article. (Author)