Experimental investigation on heat transfer enhancement and pressure drop of double pipe heat exchanger in solar water heating system

This paper presents the design and performances of double pipe heat exchanger embedded straight rectangular fins in the annulus are presented. Solar water heating systems use heat exchangers to transfer solar energy absorbed in solar collectors to the working fluid used to heat the water or a space. An experimental investigation is conducted for different set values of mass flow rate and varying the number of rectangular fins. The experimental results are validated with plain double pipe heat exchanger. The results of rectangular fins in the annulus side causes increased rate of heat transfer and pressured drop compared to plain double pipe heat exchanger. The experimental study is performed by varying mass flow rate of 0.01 kg/s, 0.02 kg/s and 0.03 kg/s of cold fluid in the annulus side and the mass flow rate of hot fluid in the inner pipe is kept constant. The performance and increased pressure drop is a function of number of fins and mass flow rate.