An Overview of Influencing Parameters on Performance of a Mantle Heat Exchanger for a Solar Water Heater – A Simulation Study

Solar domestic hot water systems are used for absorbing solar energy during day time and using it on
demand. In open-circuit cycle solar domestic hot water system, fluid inside the collector is directly
injected to water inside the tank. In the case of closed-circuit cycle, in order to transfer heat between
collector fluid and water inside the tank, a heat exchanger is used. Among all types, mantle heat
exchanger is commonly used for solar water heaters.
In this research work, the performance of an innovative collector loop heat exchanger used in solar
water heater is investigated experimentally. The heat exchanger evaluated in this work is a narrow
gap mantle on a vertical tank. The heat exchanger is assessed for a range of operating conditions to
quantify both the mantle side and the tank side heat transfer coefficients and the effect of thermal
stratification in the tank. The experiments arte simulated and validated by using CFD tool ANSYSCFX
and a good agreement is obtained between experiments and simulations.