Impact of bumpers position variation on heat exchanger performance: an experimental and predictive analysis using an artificial neural network

Abstract

Experimentally and numerically, the thermal performance enhancement of counterflow twin-pipe heat exchanger with bumpers position variation was explored. A set of semicircular bumpers were positioned at varying distances from the fluid flow entrance on the annulus gap of the concentric pipe heat exchanger (10–70, 70–130, and 130–190 cm). The hot water entered the inner pipe at a constant mass flow rate of 0.0167 kg/s, whereas the cold air entered the annulus gap of a concentric pipe heat exchanger at changing mass flow rates of 2 × 10−5 to 14 × 10−5 kg/s. The numerical portion comprised simulating the efficacy of the heat exchanger with a smooth pipe and varied bumper placements using an artificial neural network (ANN) model. The experimental portion of the present work consisted of a series of tests to determine the optimal position of the bumpers for maximizing heat exchanger efficiency. At a constant fluid inlet temperature and with varied mass flow rates of the cold air, the numerical model was compared to the experimental results. When the bumpers are put at a distance of 130–190 cm, the heat exchanger has the highest thermal efficiency compared to other bumper placements and a smooth pipe. In all cases of the investigation, there is a good correlation between numerical and experimental data.