Waste Water Heat Recovery Systems types and applications: Comprehensive review, critical analysis, and potential recommendations

One of the most effective ways to deal with the effects of the current global energy crisis is to reduce energy consumption and rely energy management strategies. As a result, waste heat/energy recovery might be a helpful option for decreasing energy costs and environmental effect. It entails finding a practical way to apply any engineering system’s wasted heat where the percentage of wasted heat is too high in global. In this context, waste hot water is a rich source of wasted energy that, if recovered, can significantly cut down on the amount of electricity used worldwide. Within this framework, the present research paper provides a thorough analysis of Waste Water Heat Recovery Systems (WWHRS) in terms of performance, design, tools and applications. In addition, it is highlighting the key elements associated with WWHRS, including the wastewater sources and approaches used in the literature for waste water heat recovery. Moreover, the present paper demonstrates the effect of the heat recovery from the drain waste water on economically and discuss the technical barriers to using WWHRS. It will be demonstrated that the feasibility of recovering heat from waste water could decrease significantly the cost of energy consumption for residential or industrial application. In addition, the main tools that are used for heat recovery systems is the heat exchanger where various types are used and the thermal performance are strongly affected by the choice of heat exchangers. Moreover, based on the literature review, it is shown that the methods of studying the thermal performance of the heat recovery system are experimental and/or numerical and in some cases the study is performed analytically. Finally, all discussed and presented studies demonstrate that the WWHRS has a significant benefits and could be considered for new residential construction.