Experimental and Numerical Study of Double Pipe Heat Exchanger (DPHE) Performance with Variation of Jagged Twisted Tape Inserts

Abstract

Double Pipe Heat Exchanger is a heat transfer device in two or more fluids, or between surfaces of solids with fluids of different temperatures. An important parameter in the heat exchanger to observe is performance because it greatly affects the overall process. Double pipe heat exchanger performance in terms of three main parameters is heat transfer, pressure drop, and effectiveness. Good performance is shown with high Nusselt numbers and effectiveness but low-pressure drop. The twisted tape is one of the most commonly used passive methods of increasing heat transfer in circular pipes, but its use can increase pressure drop. In a previous study conducted on a high flow regime above 6000 led to an increase in thermal performance and decreased pressure drop performance. This research analyzes the effect of jagged forms on twisted tape with triangular, rectangular, and trapezoidal forms in inner pipes at low flow regimes or below 5000. The length of the pipe is 1.58 m in diameter 0.017 m, the outer pipe with length 0.86 m with a diameter of 0.04 m. The heated fluid was flowed through the inner pipe with Reynolds number of 1000 to 5000 cold fluid in the outer pipe with a constant Reynolds number of 2000. From the research results obtained the highest Nusselt value among the three jagged forms is triangular with 84.47. In addition, the highest effectiveness is on a triangular variation is 0.45 with NTU is 0.33. As for the highest pressure drop value is triangular with the highest value is 865.84 Pa in a plain twist but lowest on the variation of trapezoidal form.