Design Methodology for Branching Fluid Network Heat Sinks

2006 ◽  
Author(s):  
R. M. Moreno ◽  
Y.-X. Tao
Keyword(s):  
Entropy Generation ◽  
Design Methodology ◽  
Heat Sinks ◽  
Constructal Theory ◽  
Pumping Power ◽  
Thermal Systems ◽  
Entropy Generation Minimization ◽  
Fluid Network ◽  
Fluid Networks

In this paper recent works from the areas of entropy generation minimization and constructal theory are extended and combined with previous works from the area of physiological transport geometry prediction. From this a design methodology is developed which can be applied to branching fluid networks having the objective of maximizing the removal of heat from a given volume while minimizing the pumping power required. The methods are essentially a set of equations that serve as a resource for designers incorporating branching fluid networks as components within fluid-thermal systems that have the goal of transferring and remove heat while minimizing the entropy generation or destruction of available work.

Optimized Cooling System for PEM Fuel Cell Stack Based on Entropy Generation Minimization

Volume 1 ◽  
2004 ◽  
Author(s):  
M. H. Saidi ◽  
A. A. Mozafari ◽  
L. Sharifian
Keyword(s):  
Fuel Cell ◽  
Turbulent Flow ◽  
Turbulent Flows ◽  
Entropy Generation ◽  
Design Methodology ◽  
Cooling System ◽  
Pem Fuel Cell ◽  
Fuel Cell Stack ◽  
Entropy Generation Minimization ◽  
Lower Entropy

Cell temperature in fuel cells is an important parameter which highly affects fuel cell stack efficiency. A suitable cooling system should satisfy an acceptable temperature range. In this research a relevant cooling system for a specified PEM fuel cell stack has been proposed complying with the criteria and cooling requirements of the fuel cell. The effect of various parameters on the entropy generation and temperature distribution in the cooling plates are surveyed. The number of cooling plates, the number of channels in each cooling plate and the channel width is determined. Two flow regimes namely laminar and turbulent flows of the cooling fluid in channels are analyzed and a design methodology is proposed for each regime of flow. The proposed design methodology in turbulent flow will be optimized while the work destruction is minimized. However, the proposed design in laminar flow is not the optimum one but the most efficient between different configurations. The comparison between these two proposed designs show that the turbulent flow has a lower entropy generation. In addition to entropy generation minimization, to have a desirable optimum cooling system, other parameters such as the size of the cooling plates and temperature uniformity inside cooling system have been investigated in this analysis.

Optimization of Pin-Fin Heat Sinks in Bypass Flow Using Entropy Generation Minimization Method

2008 ◽  
Vol 130 (3) ◽  
Author(s):  
W. A. Khan ◽  
J. R. Culham ◽  
M. M. Yovanovich
Keyword(s):  
Heat Transfer ◽  
Pressure Drop ◽  
Entropy Generation ◽  
Heat Sink ◽  
Heat Sinks ◽  
Entropy Generation Rate ◽  
Bypass Flow ◽  
Minimization Method ◽  
Pin Fin ◽  
Entropy Generation Minimization

An entropy generation minimization method is applied to study the thermodynamic losses caused by heat transfer and pressure drop for the fluid in a cylindrical pin-fin heat sink and bypass flow regions. A general expression for the entropy generation rate is obtained by considering control volumes around the heat sink and bypass regions. The conservation equations for mass and energy with the entropy balance are applied in both regions. Inside the heat sink, analytical/empirical correlations are used for heat transfer coefficients and friction factors, where the reference velocity used in the Reynolds number and the pressure drop is based on the minimum free area available for the fluid flow. In bypass regions theoretical models, based on laws of conservation of mass, momentum, and energy, are used to predict flow velocity and pressure drop. Both in-line and staggered arrangements are studied and their relative performance is compared to the same thermal and hydraulic conditions. A parametric study is also performed to show the effects of bypass on the overall performance of heat sinks.

Optimization of the PEM Fuel Cell Cooling System by Entropy Generation Minimization

2005 ◽  
Author(s):  
L. Sharifian ◽  
M. H. Saidi
Keyword(s):  
Fuel Cell ◽  
Entropy Generation ◽  
Cooling System ◽  
Optimization Technique ◽  
Pem Fuel Cell ◽  
Pumping Power ◽  
Plate Temperature ◽  
Cooling Fluid ◽  
Cooling Channels ◽  
Entropy Generation Minimization

Cooling system is essential for high power fuel cells to maintain cells temperature in an acceptable limit. In this paper a suitable cooling system for the PEM fuel cell has been designed and optimized. The design includes the number of the cooling plates, the proper circuit of the cooling channels in the plates, the channel dimensions, the flow rate of the cooling fluid and its temperature. The optimization technique is minimization of the entropy generation through the cooling plates. The design of the cooling channels and plates is such that the plate temperature doesn’t exceed from a desired temperature and the temperature variation in the plate becomes minimized. In this design, the coolant has a minimum pressure drop and the system needs minimum pumping power.

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