scholarly journals Velocity Boundary Layer Analysis of a Flat Plate Heat Exchanger in Laminar Flow: A Case Study

2012 ◽  
Vol 2 (6) ◽  
pp. 310-314
Author(s):  
M. Mirdrikvand ◽  
B. Roozbehani ◽  
S. I. Moqadam ◽  
A. C. Roshan ◽  
Y. Ramezani
Keyword(s):  
Boundary Layer ◽  
Heat Exchanger ◽  
Laminar Flow ◽  
Flat Plate ◽  
Cfd Simulation ◽  
Plate Heat Exchanger ◽  
Shear Stresses ◽  
Flat Plates ◽  
Plate Heat ◽  
Velocity Boundary Layer

In this article, a behavioral analysis of velocity boundary layer in a flat plate heat exchanger in laminar flow condition through CFD simulation using FLUENT software is done. The main objective of this study is to determine the velocity vectors between the flat plates of the heat exchanger. In addition, wake occurrence, differences of velocity at different surfaces between plates, angles of velocity vectors and the effect of wake phenomenon on the shear stresses exerted on the plates are discussed in detail. The study graphically illustrates results based on fluid’s behavior by a 3D and 2D simulation with air and water as cold and hot streams that affect plate’s situation and its hydro dynamical operations. Consequently, some important design features regarding wake point occurrence and pressure loss are investigated. In addition, eddy current and reverse flows in the wake area and the angles of the velocity vectors are described.

CFD SIMULATION OF A PLATE HEAT EXCHANGER WITH TRAPEZOIDAL CHEVRON

2016 ◽  
Vol 78 (8-4) ◽  
Author(s):  
Chin Yung Shin ◽  
Normah Mohd-Ghazali
Keyword(s):  
Heat Transfer ◽  
Nusselt Number ◽  
Heat Exchanger ◽  
Friction Factor ◽  
Cfd Simulation ◽  
General Pattern ◽  
Plate Heat Exchanger ◽  
Plate Heat ◽  
Flow Configuration ◽  
Heat Transfer Capacity

In this research, the trapezoidal shaped chevron plate heat exchanger (PHE) is simulated using computational fluid dynamics (CFD) software to determine its heat transfer capacity and friction factor. The PHE is modelled with chevron angles from 30° to 60°, and also the performances are compared with the plain PHE. The validation is done by comparing simulation result with published references using 30° trapezoidal chevron PHE. The Nusselt number and friction factor obtained from simulation model is plotted against different chevron angles. The Nusselt number and friction factor is also compared with available references, which some of the references used sinusoidal chevron PHE. The general pattern of Nusselt number and friction factor with increasing chevron angle agrees with the references. The heat transfer capacity found in current study is higher than the references used, and at the same time, the friction factor also increased. Besides this, it is also found that the counter flow configuration has better heat transfer capacity performance than the parallel flow configuration.

scholarly journals CFD SIMULATION OF THE HEAT TRANSFER PROCESS IN A CHEVRON PLATE HEAT EXCHANGER USING THE SST TURBULENCE MODEL

2015 ◽  
Vol 55 (4) ◽  
pp. 267 ◽  
Author(s):  
Jan Skočilas ◽  
Ievgen Palaziuk
Keyword(s):  
Heat Transfer ◽  
Heat Exchanger ◽  
Transfer Process ◽  
Cfd Simulation ◽  
Numerical Study ◽  
Analytical Calculation ◽  
Heat Transfer Process ◽  
Plate Heat Exchanger ◽  
Hot Water ◽  
Plate Heat

<p>This paper deals with a computational fluid dynamics (CFD) simulation of the heat transfer process during turbulent hot water flow between two chevron plates in a plate heat exchanger. A three-dimensional model with the simplified geometry of two cross-corrugated channels provided by chevron plates, taking into account the inlet and outlet ports, has been designed for the numerical study. The numerical model was based on the shear-stress transport (SST) <em>k-!</em> model. The basic characteristics of the heat exchanger, as values of heat transfer coefficient and pressure drop, have been investigated. A comparative analysis of analytical calculation results, based on experimental data obtained from literature, and of the results obtained by numerical simulation, has been carried out. The coefficients and the exponents in the design equations for the considered plates have been arranged by using simulation results. The influence on the main flow parameters of the corrugation inclination angle relative to the flow direction has been taken into account. An analysis of the temperature distribution across the plates has been carried out, and it has shown the presence of zones with higher heat losses and low fluid flow intensity.</p>

Experimental Study of Turbulent Flow Heat Transfer and Pressure Drop in a Plate Heat Exchanger With Chevron Plates

1999 ◽  
Vol 121 (1) ◽  
pp. 110-117 ◽  
Author(s):  
A. Muley ◽  
R. M. Manglik
Keyword(s):  
Heat Transfer ◽  
Heat Exchanger ◽  
Pressure Drop ◽  
Flat Plate ◽  
Plate Heat Exchanger ◽  
Plate Heat ◽  
Experimental Heat ◽  
Experimental Heat Transfer ◽  
Flow Heat ◽  
Phase Water

Experimental heat transfer and isothermal pressure drop data for single-phase water flows in a plate heat exchanger (PHE) with chevron plates are presented. In a single-pass U-type counterflow PHE, three different chevron plate arrangements are considered: two symmetric plate arrangements with β = 30 deg/30 deg and 60 deg/60 deg, and one mixed-plate arrangement with β = 30 deg/60 deg. For water (2 < Pr < 6) flow rates in the 600 < Re < 104 regime, data for Nu and f are presented. The results show significant effects of both the chevron angle β and surface area enlargement factor φ. As β increases, and compared to a flat-plate pack, up to two to five times higher Nu are obtained; the concomitant f, however, are 13 to 44 times higher. Increasing φ also has a similar, though smaller effect. Based on experimental data for Re a 7000 and 30 deg ≤ β ≤ 60 deg, predictive correlations of the form Nu = C1,(β) D1(φ) Rep1(β)Pr1/3(μ/μw)0.14 and f = C2(β) D2(φ) Rep2(β) are devised. Finally, at constant pumping power, and depending upon Re, β, and φ, the heat transfer is found to be enhanced by up to 2.8 times that in an equivalent flat-plate channel.

Generation of Electricity Utilizing Solar Hot Water Collectors and a Tesla Turbine

2009 ◽  
Author(s):  
Ryan Crowell
Keyword(s):  
Heat Exchanger ◽  
Flat Plate ◽  
Alternative Energy ◽  
Plate Heat Exchanger ◽  
Hot Water ◽  
Working Fluid ◽  
Solar Collectors ◽  
Gaseous State ◽  
Plate Heat ◽  
Ambient Temperatures

Threats of climate change and depleted petroleum supplies have prompted the need for eco-conscious alternative energy. This paper introduces a ground-breaking concept for harnessing the sun’s power that is significantly more efficient than existing systems. Solar collectors gather the electromagnetic radiation emitted by the sun and heat a propylene glycol to a high temperature that will then transfer the heat to a working fluid (Care30) through a plate heat exchanger. The Care30 then exits the heat exchanger in a gaseous state, and is passed through a Tesla turbine, which in turn rotates a shaft. The shaft is connected to a generator, which transforms the mechanical energy into electricity. The absorption efficiency of the solar collectors allows for mechanical loses while maintaining the overall efficiency at higher levels than any existing PV based system. Ambient temperatures drastically reduce the effectiveness of flat plate solar collectors, cooling the liquids inside before the heat can be efficiently consumed. In contrast, an evacuated tube collector maintains efficiency during such conditions. The collectors are insulated from ambient temperatures by the vacuum pressure inside the tube. A stainless steel flat plate heat exchanger is used to transfer the heat from the glycol/water solution to the refrigerant, which is sent to the turbine after it has been converted to its gaseous state. The solution also provides freeze protection in colder climates. A heat exchanger then cools the gas, returning it to its liquid state, which completes the cycle for the working fluid. The water used in the heat exchanger is then used as a supplementary heating source for the home, for domestic or radiant heating needs. As it is effective even in environments that compromise the functionality of existing PV systems, the proposed system responds effectively to the need for more efficient alternative energy sources.

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