Optimization of the Operational Energy of Tankless Water Heater

Objective/Contributions:

Fin-and-tube heat exchangers are commonly used heat exchangers for thermal energy conversion with a wide range of applications such as air conditioning, refrigeration, automotive industry, electronic devices, and the like. The demand for more efficient cooling and heating by more compact heat exchangers leads to tremendous research on this subject. This project aims to report a numerical investigation and experimental validation of the finned-tube heat exchanger used in Tankless gas water heater (TGWH) operation. Since the demand for hot water is crucial in almost any residential building, the tankless gas water heater is the most used device for that purpose compared with the storage water heater because of its small size, reduced energy use, longer life, and continuous flow of heated water. On the one hand, 3D models in real dimensions, for a typical TGWH will be created to be used in the Computational Fluid Dynamics (CFD) simulations to study the thermal and hydraulic performance of the heat exchanger.

On the other hand, an experimental setup will be built to validate the obtained numerical results to show that the study can predict the flow field and temperature field in the tankless water heater with acceptable accuracy. The study will cover the effect of heat exchanger parameters on the air-side flow and heat transfer characteristics, aiming to increase the operational efficiency without taking the dew point limit into consideration. Then, the increase in the efficiency will be used to decrease the amount of copper used in the heat exchanger, taking into consideration the limit on the efficiency imposed by the dew point. Additionally, suitable sensors will be selected and integrated with predictive control strategies will be developed which, due to their predictive nature, allow anticipating and minimizing the undesired effects on water temperature due to sudden variations of water flow rate. The foremost expected outcome is a direct impact on the local industry of manufacturing the heat exchanger of TGWT, especially since we have two collaborators from the industry namely, Matin technology company and Universal company since the project will suggest an enhanced model of heat exchanger be used in commercial TGWH in Egypt, accordingly reduction in the used material which will reduce the manufacturing cost, also successfully implementing a predictive control strategy for more efficient and sustainable use of energy. 

Outcome: Publications

• El-Sahhar, T.M., Guaily, A. and Boraev, M.A., 2022, October. Numerical investigation of thermal and hydraulic performance of tankless water heater tubes with various aspect ratio. In 2022 4th Novel Intelligent and Leading Emerging Sciences Conference (NILES) (pp. 221-224). IEEE. 
• El-Sahhar, T.M., Guaily, A. and Boraey, M.A., 2022, October. Numerical Investigation of Tankless Water Heater thermal performance. In 2022 4th Novel Intelligent and Leading Emerging Sciences Conference (NILES) (pp. 01-04). IEEE.