Experimental studies on a corrugated plate heat exchanger for small temperature difference applications

Experimental studies were performed on a corrugated plate heat exchanger for small temperature difference applications. Experiments were performed on a single corrugation pattern on 20 plates arranged parallelly, with a total heat transfer area of 1.16298 m(2). The spacing, Delta X, between the plates was varied (Delta X = 6 mm, 9 mm, and 12 mm) to experimentally determine the configuration that gives the optimum heat transfer. Water was used on both the hot and the cold channels with the flow being parallel and entering the heat exchanger from the bottom. The hot water flowrates were varied. The cold side flowrate and the hot and cold water inlet temperatures were kept constant. It is found that for a given Delta X, the average heat transfer between the two liquids increases with increasing hot water flowrates. The corrugations on the plates enhance turbulence at higher velocities, which improves the heat transfer. The optimum heat transfer between the two streams is obtained for the minimum spacing of Delta X = 6 mm. The pressure losses are found to increase with increasing flowrates. The overall heat transfer coefficients, U, the temperature difference between the two stream at outlet, and the thermal length are also presented for varying hot water flowrates and Delta X. The findings from this work would enhance the current knowledge in plate heat exchangers for small temperature difference applications and also help in the validation of CFD codes. (C) 2011 Elsevier Inc. All rights reserved.