Search

The combined heat and water (CHW) system has been studied by many scholars since it was proposed, and a project has been implemented in Shandong, China in 2021. However, there have been few studies on optimization and comparisons of cases on the heat source side of CHW. Taking a coal-fired thermal power plant as an example, through the reasonable matching of steam flows and analysis of thermal economic parameters, the effect number and heat source steam temperature of a multi-effect distillation (MED) + multi-stage flash (MSF) combined heat and water production (CHWP) system were optimized. The optimal MED heat source temperature was found to be 70 °C, and the optimal MED and MSF effect numbers were 10 and 5, respectively. Finally, the waste heat in the power plant was utilized as much as possible throughout the year. Compared with two cases of the separate heat and water production (SHWP) system, the CHWP system easily achieved better water quality and economy under the condition of almost equal exergy efficiency, and it was easier to realize than the first case of the SHWP system. • Effect number and heat source temperature of desalination process are optimized. • Thermal economic analysis of combined heat and water production system is carried. • Annual utilization of waste heat from a thermal power plant is maximized. • Seasonal matching problem of the system is discussed and tried to be solved. [ABSTRACT FROM AUTHOR]