Published Paper Details:

Heat transfer fluids carry heat from heat collectors to the heat storage tanks in heating (and cooling) systems. The fluids most commonly used are water, propylene glycol, ethylene glycol and air. Less common fluids are synthetic hydrocarbons, paraffin hydrocarbons, aromatic refined mineral oils, refrigerants, and silicones. While selecting a heat transfer fluid, we consider the following criteria the coefficient of expansion, viscosity, thermal capacity; freezing point, boiling point, and flash point are considered. For example, in a cold climate, solar systems require fluids with low freezing points. Fluids exposed to high temperatures, as in a desert climate, should have a high boiling point. Viscosity and thermal capacity determine the amount of pumping energy required. A fluid with low viscosity and high specific heat is easier to pump, because it is less resistant to flow and transfers more heat. Other properties that help determine the effectiveness of a fluid is its corrosiveness and stability. In the present work an attempt was made to arrive at the best combination which would give the best heat transfer rate and how the porosity effected the heat transfer rate in the system.