Improving the efficiency of electric water heating systems is essential for reducing energy use and supporting sustainable energy utilization. This study presents the development and optimization of an ultra-efficient electric water heater incorporating graphene-enhanced thermal elements to improve heat-transfer performance and overall system efficiency. The proposed design utilizes graphene-based extended surfaces to enhance heat spreading and increase the effective heat-transfer area of the heating element. A combined numerical analysis and three-dimensional transient simulation approach was employed to evaluate the thermal behavior of the system and quantify the performance improvements achieved through design optimization. The results demonstrate significant enhancement in heating performance compared with conventional heater configuration. Under identical operating conditions, the optimized heater achieved up to a 68.4% reduction in the modeled heater-side thermal load, while maintaining the required heating performance. Additionally, the effective heat-transfer rate increased by approximately 108%, primarily due to a 102% increase in effective heat-transfer area resulting from geometric refinement of the heating surfaces. The incorporation of graphene improved heat distribution within the heating element and facilitated more efficient heat transfer to the surrounding water. These improvements lead to enhanced thermal utilization, reduced peak heating demand, and improved compatibility with renewable energy systems, highlighting the strong potential of graphene-based thermal enhancements for next-generation high-efficiency electric water heating technologies.
Alzahrani et al. (Fri,) studied this question.