The Effect of the Corrugation Inclination Angle on the Thermohydraulic Performance of Plate Heat Exchangers
ABSTRACT It is well established that the inclination angle between plate corrugations and the overall flow direction is a major parameter in the thermohydraulic performance of plate heat exchangers. Application of an improved flow visualization technique has demonstrated that at angles up to about 80° the fluid flows mainly along the furrows on each plate. A secondary, swirling motion is imposed on the flow along a furrow when its path is crossed by streams flowing along furrows on the opposite wall. Through the use of the electrochemical mass transfer analogue, it is proved that this secondary motion determines the transfer process; as a consequence of this motion the transfer is fairly uniformly distributed across the width of the plates. The observed maximum transfer rate at an angle of about 80° is explained from the observed flow patterns. At higher angles the flow pattern becomes less effective for transfer ; in particular at 90° marked flow separation is observed.
- SourceAvailable from: Debendra K. Das
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- "These experimental results allowed us to compare quantitatively, the thermal and fluid dynamic performance of a nanofluid and abase fluid. Theoretical: A detailed theoretical study using the well-established single-phase fluid correlation of Focke et al.  for PHE was conducted by means of Matlab scripts to compare the fluid dynamic and thermal performance of four heat transfer mediums on the hot side. The mediums are: EG/W 60:40 pure liquid and three nanofluids of Al 2 O 3 , CuO and SiO 2 nanofluids of 1% volumetric concentration in the same base fluid. "
ABSTRACT: Three nanofluids comprising of aluminum oxide, copper oxide and silicon dioxide nanoparticles in ethylene glycol and water mixture have been studied theoretically to compare their performance in a compact minichannel plate heat exchanger (PHE). The study shows that for a dilute particle volumetric concentration of 1%, all the nanofluids show improvements in their performance over the base fluid. Comparisons have been made on the basis of three important parameters; equal mass flow rate, equal heat transfer rate and equal pumping power in the PHE. For each of these cases, all three nanofluids exhibit increase in convective heat transfer coefficient, reduction in the volumetric flow rate and reduction in the pumping power requirement for the same amount of heat transfer in the PHE. On the cold fluid side of the heat exchanger, a coolant, HFE-7000, has been studied, which has the potential for application in extremely low temperatures, but has not been investigated widely in the literature. Experimental data measured from a minichannel PHE in a test loop using water as the base fluid have validated the test apparatus with excellent agreement of predicted heat transfer rate and the overall heat transfer coefficient with the experimental values. From experiments on a 0.5% aluminum oxide nanofluid, preliminary correlations for the Nusselt number and the friction factor for nanofluid flow in a PHE has been derived. This apparatus will be useful to test different kinds of nanofluids to ultimately determine the effects of parameters such as: volumetric concentration, particle size and base fluid properties on thermal and fluid dynamic performance of nanofluids in compact heat exchangers.International Journal of Heat and Mass Transfer 04/2014; 71:732-746. DOI:10.1016/j.ijheatmasstransfer.2013.12.072 · 2.52 Impact Factor
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- "Also, it is possible to use a combination of different plates to create an intermediate NTU passage, which can be used to meet a specific NTU requirement. Focke.W.W  suggested that one of the important parameters in the thermal performance of the plate heat exchangers is the inclination angle between plate corrugations and the overall flow direction. Mehrabian and Pouter  investigated the local hydrodynamic and thermal characteristics of the flow between two identical APV SR3 plates. "
ABSTRACT: Introduction Plate Heat Exchangers have many applications in the food, petrochemical, power plant, oil and chemical industry. Compared to other types of heat exchangers, such as shell and tube, plate heat exchangers are commonly used because of their compactness, ease of production, sensitivity, easy care after set-up and efficiency. Basically, the plate heat exchanger is a series of individual plates that pressed between two heavy and covers. Depending on the application the heat exchanger, these plates are gasketed, welded or brazed together. The pressed pattern on each plate surface induces turbulence and minimizes stagnant areas and fouling. Unlike shell and tube heat exchangers, which can be custom-built to meet almost any capacity and operating conditions, the plates for plate and frame heat exchangers are mass-produced using expensive dies and presses. Although the plate heat exchangers are made from standard parts, each one is custom designed as variation in the chevron angle, flow path or flow gap can alter the number of transfer units in the heat exchangers. Decreasing the chevron angle from 90 o , the path becomes more tortuous and offers greater hydrodynamic resistance giving rise to high NTU (The number of transfer unit) characteristics. Also, it is possible to use a combination of different plates to create an intermediate NTU passage, which can be used to meet a specific NTU requirement. Focke.W.W  suggested that one of the important parameters in the thermal performance of the plate heat exchangers is the inclination angle between plate corrugations and the overall flow direction. Mehrabian and Pouter  investigated the local hydrodynamic and thermal characteristics of the flow between two identical APV SR3 plates. They also studied the effect of corrugation angle on the thermal performance of the heat exchanger when plate spacing is fixed. Laminar periodically developed forced convection in sinusoidal corrugated-plate channels with uniform wall temperature and single-phase constant property flows was considered by Metwally and Mbanglik . Gradeck et.al,  conducted experiments in order to study the effects of hydrodynamic conditions on the enhancement of heat transfer. They performed these experiments for a wide range of Reynolds numbers. Finally, they pointed out a strong relation between the wall velocity gradient and the Nusselt number. Bobbili and Sunden  conducted experimental investigations to find the flow and the pressure difference across the port to channel in plate heat exchangers for a wide range of Reynolds numbers ()
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- "Successive plates are assembled with the chevron patterns pointing in opposite directions, thereby producing a complex three-dimensional flow passage (Shah and Focke, 1988; Saunders, 1988). Previous investigations have shown that the corrugation angle is a major parameter influencing PHE thermal and hydraulic performance (Focke et al., 1985; Muley and Manglik, 1999). Moreover, the flow pattern inside the channel, which can be diagonal or parallel depending on the gasket type (see Figure 1), also influences the PHE performance, especially for wide plates (Bansal et al., 2001). "
ABSTRACT: The study of non-Newtonian flow in plate heat exchangers (PHEs) is of great importance for the food industry. The objective of this work was to study the pressure drop of pineapple juice in a PHE with 50º chevron plates. Density and flow properties of pineapple juice were determined and correlated with temperature (17.4 < T < 85.8ºC) and soluble solids content (11.0 < Xs< 52.4 ºBrix). The Ostwaldde Waele (power law) model described well the rheological behavior. The friction factor for non-isothermal flow of pineapple juice in the PHE was obtained for diagonal and parallel/side flow. Experimental results were well correlated with the generalized Reynolds number (20 < Reg< 1230) and were compared with predictions from equations from the literature. The mean absolute error for pressure drop prediction was 4% for the diagonal plate and 10% for the parallel plate.Brazilian Journal of Chemical Engineering 12/2010; 27(4):563-571. DOI:10.1590/S0104-66322010000400008 · 0.91 Impact Factor