Helical heat exchangers are commonly used to exchange the thermal energy in waste heat recovery systems. Ammonia rectifier in absorption chiller and heat recovery steam generator are examples typically found in open literature. They are widely employed because of its compactness, high heat exchange rate, compensation of thermal expansion, vibration resistance, simple construction, and low capital cost. Heat exchanger researches have almost focused on straight tubes. However, study on helical heat exchanger has not been paid attention. In this study, a simplified model is developed to predict single phase heat transfer and pressure loss in the helical heat exchanger under various operating conditions without geometrical information inside the exchanger required. Methods of LMTD and e-NTU, and selective empirical correlations are presented in the model. Simulation results were achieved good agreement with the experimental data with a moderate tolerance. The model would be expected as a good tool for designers to the pre-design and correct selection of helical heat exchanger in thermal network.
Cited as: Phu, N.M., Huy, H.T.T, Truyen, L.T. and Tho, T.T., 2016. Prediction in off-design operation for the helical heat recovery exchanger. Can Tho University Journal of Science. Special issue: Renewable Energy: 46-51.
Tạp chí khoa học Trường Đại học Cần Thơ
Lầu 4, Nhà Điều Hành, Khu II, đường 3/2, P. Xuân Khánh, Q. Ninh Kiều, TP. Cần Thơ
Điện thoại: (0292) 3 872 157; Email: tapchidhct@ctu.edu.vn
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