Heat transfer measurement in a three-phase spray column direct contact heat exchanger for utilisation in energy recovery from low-grade sources.pdfVIP

Energy Conversion and Management 126 (2016) 342–351 Contents lists available at ScienceDirect Energy Conversion and Management journal homepage: /locate/enconman Heat transfer measurement in a three-phase spray column direct contact heat exchanger for utilisation in energy recovery from low-grade sources Ali Sh. Baqir a, Hameed B. Mahood b,?, Mudher S. Hameed b, Alasdair N. Campbell c a Al-Furat Al-Awsat Technical University, Al-Najaf Engineering Technical College, Department of Aeronautical Engineering, Al-Najaf, Iraq b University of Misan, Misan, Iraq c Department of Chemical and Process Engineering, University of Surrey, UK article info Article history: Received 11 June 2016 Received in revised form 26 July 2016 Accepted 8 August 2016 Available online 12 August 2016 Keywords: Spray column three-phase direct contact heat exchanger Local volumetric heat transfer coef?cient Active height Sparger con?guration abstract Energy recovery from low-grade energy resources requires an ef?cient thermal conversion system to be economically viable. The use of a liquid-liquid-vapour direct contact heat exchanger in such processes could be suitable due to their high thermal ef?ciency and low cost in comparison to a surface type heat exchanger. In this paper, the local volumetric heat transfer coef?cient (Uv) and the active height (Hv) of a spray column three-phase direct contact heat exchanger (evaporator) have been investigated experimentally. The heat exchanger comprised a cylindrical Perspex tube of 100 cm height and 10 cm diameter. Liquid pentane at its saturation temperature and warm water at 45 °C were used as the dispersed phase and the continuous phase respectively. Three different dispersed phase ?ow rates (10, 15 and 20 L/h) and four different continuous phase ?ow rates (10, 20, 30 and 40 L/h) were used throughout the experiments. In addition, three different sparger con?gurations (7, 19 and 36 nozzles) with two different nozzle diameters (1 and 1.25 mm) were tested. Th