By combing a supercritical CO2 (sCO2) Brayton cycle and a direct contact membrane distillation (DCMD) block, an energy-efficient water and electricity cogeneration is proposed. Two layouts of the hybrid system are designed. Thermodynamic analysis for the hybrid system is carried out by considering the effects of the operation conditions and the membrane properties. With the on-design parameters input, the energy efficiency of the layout 1 and layout 2 is 38.48% and 37.52%, respectively. By optimizing the parameters, the energy efficiency can be further improved. Although the layout 1 has higher energy efficiency, the layout 2 has larger variation ranges of the parameters due to the less limitation of the pinch point temperature difference in the intermediate heat exchanger (IHX).
Keywords sCO2 power cycle, Membrane distillation, Electricity/water cogeneration, Thermodynamic analysis