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J. Coates

Bio: J. Coates is an academic researcher. The author has contributed to research in topics: Convection & Reynolds number. The author has an hindex of 1, co-authored 1 publications receiving 9 citations.

Papers
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Journal Article
Abstract: A review is presented on methods of calculating heat transfer to moving fluids. Correlations are given for heat transfer coefiicients for fluids undergoing no change of phase, both inside and outside a conduit. Various resistances encountered in convective heat transfer are given. The use of dimensional analysis to correlate data is discussed, with correlations for low Reynolds numbers. Film coefficients for phase changes are discussed. (C.J.G.)

9 citations


Cited by
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Journal ArticleDOI
03 Jun 2016-Energies
TL;DR: In this paper, a helical coil heat exchanger was designed by using heat transfer correlations from the literature and their estimated uncertainty is ~20% in order to account for the heat transfer correlation uncertainties this component was oversized by 20%.
Abstract: Worldwide interest in low grade heat valorization using organic Rankine cycle (ORC) technologies has increased significantly. A new small-scale ORC with a net capacity of 3 kW was efficiently integrated with a concentrated solar power technology for electricity generation. The excess heat source from Photovoltaic (PV) collectors with a maximum temperature of 100 °C was utilized through a supercritical heat exchanger that uses R-404A as working medium. By ensuring supercritical heat transfer leads to a better thermal match in the heat exchanger and improved overall cycle efficiency. A helical coil heat exchanger was designed by using heat transfer correlations from the literature. These heat transfer correlations were derived for different conditions than ORCs and their estimated uncertainty is ~20%. In order to account for the heat transfer correlation uncertainties this component was oversized by 20%. Next, a prototype was built and installed in an integrated concentrated photovoltaic/thermal (CPV/T)/Rankine system. The results from the measurements show that for better estimation of the sizing of the heat exchanger a more accurate correlation is required in order to design an optimal configuration and thus employ cheaper components.

38 citations

Journal ArticleDOI
TL;DR: In this article, a model was established to simulate the heat transfer of shell-side film flow in real working conditions, and the influence of rolling parameters and working parameters on shell side heat transfer characteristic was investigated.

34 citations

Journal ArticleDOI
TL;DR: In this paper, the authors numerically study boiling heat transfer on the shell-side of spiral wound heat exchanger (SWHE), and the physical model for the shell side of SWHE is established and the volume of fluid (VOF) method is used in the calculation.
Abstract: The aim of this paper is to numerically study boiling heat transfer on the shell-side of spiral wound heat exchanger (SWHE). The physical model for the shell-side of SWHE is established and the volume of fluid (VOF) method is used in the calculation. For propane and ethane, there are thirty cases to be simulated . Through the comparison with experimental data, the cause which leads to the simulation distortion is found, and the satisfied results of calculation are finally achieved. The simulation results show that the VOF model can be adopted well to those calculations whose inlet quality are lower than 0.1 kg/kg, and the calculation deviations are generally within ±20 %. In falling film flow, the heat transfer performance for the shell-side of SWHE is primarily influenced by Reynolds number. The visualization of simulation results displays that the boiling bubbles have three flow directions, besides flowing down with liquid phase, one portion of bubbles flows reversely up, and another portion is blocked at axial gaps of coils where the heat transfer is reduced. The studies of boiling on the shell-side of SWHE not only reveal the characteristics of heat transfer, but also point out the improvement direction of SWHE.

24 citations

Journal ArticleDOI
TL;DR: In this article, a three fluid heat exchanger is analytically modeled in order to predict the effects of different design parameters on its thermal performances, and the optimum values of these parameters relating to maximum heat transfer and minimum pressure drop are assessed using Taguchi based optimization technique.
Abstract: In this paper, a three fluid heat exchanger is analytically modeled in order to predict the effects of different design parameters on its thermal performances. The optimum values of these parameters relating to maximum heat transfer and minimum pressure drop are assessed using Taguchi based optimization technique. The present heat exchanger is an improvement of double tube heat exchanger, where a helical coil is inserted in the annular space occupied in between two straight tubes. It is different from other three fluid heat exchangers with respect to construction, flow arrangement and thermal communication point of view, where the hot water is flowing through the helical coil as the heating fluid and continuously transferring thermal energy to normal water and air, which are flowing, in outer annulus and innermost straight tube. The results of the analytical approach are compared and validated against literature and good conformity between them is observed. The temperature distributions of three different fluids along the length of the present heat exchanger are assessed analytically for different flow configurations. Three different non-dimensional design parameters i.e. curvature ratio, non dimensional coil pitch and coil side Reynolds number are selected and their effect on heat transfer and pressure drop characteristics i.e. coil side Nusselt number, effectiveness and friction factor respectively are assessed. It is found that, for tube size 0.0045 m, coil pitch 0.013 m, coil diameter 0.04253 m and hot water flow rate 5 liters per minute, present heat exchanger will perform optimum. It is also resulted that, volumetric flow rate of hot water is the most effective parameter affecting heat transfer with a contribution ratio of 66.82% and tube size is the most effective parameters affecting pressure drop with a contribution ratio of 71.07%.

10 citations

Journal ArticleDOI
TL;DR: In this article, a shell and helical coil type of Solution Heat Exchanger (SHX) is investigated with more emphasis on the dimensionless correlation of shell side co-efficient, which decides the overall heat transfer coefficient and the size of heat exchanger.

10 citations