Experimental Investigation of Flow and Heat Transfer Characteristics of Latent Functionally Thermal Fluid in Mini-Tube

An experimental research using the latent functionally thermal fluid of n-hexadecane microcapsules in deionized water was conducted in order to investigate the flow and heat transfer characteristics of microencapsulated phase change material (MEPCM) slurry. Experimental measurements were done for a large region of Reynolds number in the mini-tube with a constant wall heat flux. Experimental measurements were also conducted using deionized water as the working fluid under the same conditions. Some important parameters such as pressure, temperatures of wall and fluid were obtained experimentally. The relationships between pressure drop and mass flow rate, dimensionless outlet temperature of working fluid and Reynolds number, mean convective heat transfer coefficient and Nusselt number and Reynolds number were obtained. Results show that the using of MEPCM particle increases the pressure drop and then close to that of single phase water with increasing mass flow rate. The outlet and wall temperatures decrease 50% comparing with single phase water under the same conditions. The Nusselt number of slurry containing small concentration MEPCM particle is about 2.0–2.3 times greater than that of single phase water in the minitube. The experimental data might be helpful in the design of thermal-energy transportation systems in small scale using MEPCM slurry.