A theoretical study of Cu-H2O nano-fluid effect on heat transfer enhancement of a solar water heater

In the present work, an attempt has been made to enhance the heat transfer in a solar water heater by using Cu nano-particles dispersed in water for various concentrations ranging from 0% to 5%. Considerable improvement in the solar collector efficiency is obtained by increasing the nano-particle concentration up to 17.5 for a concentration of 5% and for a mass flow rate ratio of 10. The outlet water temperature increases by increasing the nano-particle concentration up to 8.35% for a concentration of 5% and for a mass flow rate ratio of 5. The study showed that the solar heater collecting area takes into account significant factors for increasing the outlet temperature. An increase in the collecting area of the solar water heater by 6 times could increase the water temperature by 39% for a 5% nano-particle volume fraction. The helical heat exchanger effectiveness is increased up to 65.71 for a concentration of 5% for a mass flow rate ratio of 10. © 2015 Informa UK Limited, trading as Taylor & Francis Group.