An effective engineering computational procedure to analyse and design rotary regenerators using a porous media approach

Alhusseny, Ahmed; Turan, Ali

doi:10.1016/j.ijheatmasstransfer.2015.12.033

Cited by 27 publications

(10 citation statements)

References 22 publications

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“…As in the porous media approach of the rotating regenerator studied by Ahmed Alhusseny and Turan, the rotor of the GGH system is assumed to be the porous media, and the input values of the porous elements are replaced by the results of the heating element analysis [24]. Among the diverse types of heating elements, in this study, the L-type heating element was used, owing to its efficient heat transfer rate and low pressure-loss coefficient.…”

Section: Integrated Analysis Modelmentioning

confidence: 99%

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Optimization of the Heating Element in a Gas-Gas Heater Using an Integrated Analysis Model

et al. 2017

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Gas-gas heaters (GGHs) are used to reheat gases through desulfurization in coal-fired power plants to reduce low-temperature corrosion and white smoke. Wrinkled heating elements are installed inside the GGH to perform effective heat exchange. An optimization study of the heating element shape was conducted to reduce the differential pressure effectively and improve performance. An integrated analysis model was applied. Based on actual operational data, a computational fluid dynamic analysis was conducted on the L-type heating element and GGH system. The experiments applied the optimal latin hypercube sampling method, and numerical analysis was performed for each sample. Based on the response surface, the result of the sample was optimized through the pointer algorithm. For the integrated analysis model, validation was performed by comparison with the actual operational data, and the thermal-fluid characteristics of the heating element and GGH system were analyzed to set three parameters: plate angle, undulated angle, and pitch 1. From the optimization result, increases in the undulated angle and pitch 1 reduce the pressure drop by widening the heating element cross section. By increasing the plate angle, the heat transfer area is secured and the reduced heat transfer coefficient is compensated, improving the GGH performance.

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Section: Integrated Analysis Modelmentioning

confidence: 99%

“…A conceptual optimization of a rotary heat exchanger was performed by Dallaire et al [23]. Recently, a rotary heat exchanger considering the shape of the heating element was studied [24].…”

Section: Introductionmentioning

confidence: 99%

Optimization of the Heating Element in a Gas-Gas Heater Using an Integrated Analysis Model

et al. 2017

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“…Many researchers have paid attention to heat wheels in the past years through numerical, analytical or experimental studies [2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18]. Most of attempts in this area were focused on modeling rotary regenerators to calculate their effectiveness, outlet temperatures, matrix temperature distribution, and leak flows.…”

Section: Introductionmentioning

confidence: 99%

“…Bearing in mind that they ignored flow leakage, it indicates that a CFD simulation (with methods and assumptions they used) may over predicts the heat transfer in a RAH. In another research [2], the authors demonstrated by a 3D numerical method in laminar regime that circular and square passages have a better overall system performance (heat transfer to pumping power) comparing to a triangular passage. Temperature distribution over a rotary regenerator was obtained in another work by CFD modeling and considering the matrix as a porous media [7].…”

Section: Introductionmentioning

confidence: 99%

Optimization of a three-layer rotary generator using genetic algorithm to minimize fuel consumption

Abroshan¹,

Goodarzi²

2020

JMES

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Reduction of fuel consumption in power plants is an important issue due to their high rate of fuel usage. In the present article, this was done by optimizing rotary regenerator which have a great role in recovering thermal energy in power stations. Heat transfer and pressure drop through 13 popular flow passages of power plant's rotary regenerators were obtained by CFD simulations. The outcomes were used in a mathematical model of the rotary air heater by considering air leakages. The model was capable of distinguishing between different heating surfaces. Then it was used for optimizing a regenerator by genetic algorithm. Rotational speed and dimensions of all three layers (hot end, intermediate layer, and cold end) were optimized to achieve the highest fuel saving. These dimensions were: hydraulic diameters, heating profile type, and length of each layer. Results showed that redesigning these parameters to the optimal values leads to saving of 443 kg of natural gas per hour for one regenerator. A 10 meter regenerator also had the highest reduction in fuel consumption (660 kg/hr). Finally, the influence of air and hot gas temperatures, and air mass flow rate on fuel saving and optimum values of design parameters was discussed.

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“…To achieve a high thermal efficiency in power generation systems, heat recirculation is applied between the cold intake and hot exhausts to recover a part of its thermal energy instead of releasing it directly to the environment (Alhusseny and Turan [1]). Heat recirculation is usually accomplished by means of two options.…”

Section: Introductionmentioning

confidence: 99%

Rotating metal foam structures for performance enhancement of double-pipe heat exchangers

Alhusseny

Turan

Nasser

2017

International Journal of Heat and Mass Transfer

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In order to enhance the amount of heat transported in a double-pipe heat exchanger, a compound enhancement is proposed incorporating both active and passive methods. The first one is through introducing secondary flows in the vicinity of the conducting surface using metal foam guiding vanes, which are fixed obliquely and rotating coaxially to trap fluid particles while rotation and then force them to flow over the conducting surface. The other is via covering the conducting surface between the two pipes with a metal foam layer to improve the heat conductance across it. This proposal is examined numerically by studying the three-dimensional, steady, incompressible, and laminar convective fluid flow in a counter-flow double-pipe heat exchanger partially filled with high porosity metal foam and rotating coaxially. With regards to the influence of rotation, both the centrifugal buoyancy and Coriolis forces are considered in the current study. The generalised model is used to mathematically simulate the momentum equations in the porous regions. Moreover, thermal dispersion has been taken into account while considering that fluid and solid phases are in a local thermal non-equilibrium. Computations are performed for a wide range of design parameters influencing the performance achieved such as the operating conditions, the configuration of the guiding vanes utilized, and the geometrical and thermal characteristics of the metal foam utilised. The results are presented by means of the heat exchanger effectiveness, pressure drop, and the overall system performance. The current proposed design has effectively proved its potential to enhance the heat transported considerably in view of the significant savings in the pumping power required compared to the heat exchangers fully filled with metal foams. Furthermore, the data obtained reveal an obvious impact of the design parameters inspected on both the heat exchanged and the pressure loss; and hence, the overall performance obtained. Although the heat exchanger effectiveness can be improved considerably by manipulating the design factors, care must be taken to avoid unnecessary expenses resulted from potential increases in pressure drop. KEYWORDS: Heat Exchanger, Compound Enhancement, Metal Foams, Rotation, Overall PerformanceNomenclature asf solid-to-fluid interfacial specific surface area cp specific heat of fluid phase Cc cold stream heat-capacity rate Cc = ṁc cp,c Ch cold stream heat-capacity rate Ch = ṁh cp,h Cmin the smaller of the hot (Ch) and the cold (Cc) fluid-phase heat-capacity rates df fiber diameter dp pore diameter Da Darcy number, Da=K / Dh 2 Dh hydraulic diameter of the channel Di1, Di2 internal and external diameters of the inner annular tube Do1, Do2 internal and external diameters of the outer annular tube F inertial coefficient hsf solid-to-fluid interfacial specific heat transfer coefficient Hsf dimensionless solid-to-fluid interfacial specific heat transfer coefficient k thermal conductivity K permeability of the porous medium

show abstract

An effective engineering computational procedure to analyse and design rotary regenerators using a porous media approach

Cited by 27 publications

References 22 publications

Optimization of the Heating Element in a Gas-Gas Heater Using an Integrated Analysis Model

Optimization of the Heating Element in a Gas-Gas Heater Using an Integrated Analysis Model

Optimization of a three-layer rotary generator using genetic algorithm to minimize fuel consumption

Rotating metal foam structures for performance enhancement of double-pipe heat exchangers

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