Performance investigation of a novel water–power cogeneration plant (WPCP) based on humidification dehumidification (HDH) method

Abstract

Humidification dehumidification (HDH) technology was well applied to produce freshwater in the desalination system. However, besides the demand of freshwater, power is also required simultaneously in most situations. In the paper, a novel water–power cogeneration plant (WPCP) based on the HDH desalination system coupled with the organic Rankine cycle (ORC) is proposed. Energy analysis for the proposed combined system at different appointed operation parameters is achieved, and the corresponding performance correlation between the HDH desalination and ORC power system are revealed. It is verified that the production of freshwater and electricity can be gained synchronously in the suggested novel platform, and the performance of the whole system is really sensitive to the operation parameters of the HDH desalination system. It is found that after the regulation of the operation pressure, p, and the seawater temperature at the outlet of the seawater heater, Tsw,2, for the HDH desalination from p=0.1MPa, Tsw,2=353.15K to p=0.3MPa, Tsw,2=383.15K, a maximum elevation, 25.46kgh−1 for the freshwater production, 4.17kW for the electricity and 2% for the extended gained output ratio (EGOR) is obtained. Furthermore, owing to the asynchronism between the specific production and the final energy utilization efficiency, the balance should be optimized among the demand of the freshwater and power and the efficiency of the novel WPCP.