Optimized hydraulic diameter and operating condition of tube heat exchanger for food industry – A numerical study

This work reports the design optimization of a tube heat exchanger, which is widely employed and integrated in the stove system in small scale food processing industry in Indonesia. The optimization parameters were the tube diameter and the flow rate of working fluids, which are later corelated to the heat exchanger effectiveness (ε). Numerical investigation using Computational Fluid Dynamics (CFD) with viscous model of kε RNG was undertaken to obtain the optimum parameter. The tube diameter was varied by 0.5, 1, and 1.5 in while the flow rate was varied by using initial inlet velocity of 1.6, 3.6, and 5.6 m‧s^-1. The results indicate that the highest ε of 1.36 can be achieved using 0.5 in tube diameter with the slowest inlet velocity (1.6 m‧s^-1). This result is manifested by the higher temperature difference between the outflow and inflow, and the considerably low pressure drop amongst all variation. Therefore, this study recommends the current food processing industry to redesign the existing tube heat exchanger in order to increase the production efficiency.