scholarly journals Numerical analysis and performance enhancement of compact heat exchanger using computational fluid dynamics

2021 ◽  
Author(s):  
Agarwal A. ◽  
◽  
Molwane O.B ◽  
Pitso I ◽  
◽  
...  
Keyword(s):  
Heat Transfer ◽  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Heat Exchanger ◽  
Heat Exchangers ◽  
Compact Heat Exchanger ◽  
Cfd Analysis ◽  
Heat Transfer Characteristics ◽  
Good Efficiency ◽  
Transfer Characteristics

Compact heat exchangers are used in various industries due to its good efficiency and compactness. The fluid used in heat exchanger has significant effect in augmentation of heat transfer characteristics of heat exchangers. In recent years, researchers have shown keen interest in uses of nanofluids for heat exchangers due to its good thermo-physical properties. The present study explores the application of ZnO /water nanofluid on compact heat exchanger with circular tubes using techniques of Computational Fluid Dynamics (CFD). The CAD model is developed in Creo design software and CFD analysis is conducted using ANSYS CFX. The volume concentration of nanoparticles used for analysis are .02,.04 and .07. The CFD analysis is conducted for both laminar and turbulent flow regime using SSG shear stress turbulence model. The temperature distribution, Nusselt number and pressure plots are generated to determine heat transfer characteristics. The results are encouraging, and significant enhancement of heat transfer is achieved using ZnO/water nanofluid. However, the pumping power requirement also increased with increase in nanoparticle concentration.

Study of Heat Transfer Characteristics for the Fuel Cell System of the Humidifier due to Analysis and the Hot Testing

2011 ◽  
Author(s):  
Seon-hwa Kim ◽  
Jae-jun Lee ◽  
Young-min Oh ◽  
Sang-hoon Lee ◽  
Jae-sik Kim
Keyword(s):  
Heat Transfer ◽  
Heat Exchanger ◽  
Fuel Cell ◽  
Heat Exchangers ◽  
Thermal Characteristic ◽  
Cell System ◽  
Test Facility ◽  
Heat Transfer Characteristics ◽  
Transfer Characteristics ◽  
Operation Temperature

The MCFC system of BOP (Balance of Plant) is contained various mechanical equipments. One of the equipments of the heat exchangers is important component for efficiency and cost. In MCFC system, several heat exchangers are used according to the application. Most typical heat exchanger is the humidifier in BOP for MCFC, which is named for the humidifier because it is to preheat the fuel and water so that a reactor will convert some of the incoming fuel to hydrogen. Then, hot side fluid service is used the exhausted gas from the fuel cell and cold side fluid service is the fuel and water. The operation temperature range is about 25∼500 Celsius Degree.[1] This heat exchanger has the problems of multiphase fluid and phase change heat transfer. So it is necessary to analyze the heat transfer characteristics and to propose the reasonable design methodology for the humidifier. In this study, the thermal characteristic for the humidifier is estimated by using commercial tool of heat exchanger design, rating and simulation. Also this study presents the results for test facility of fabrication and for testing.

The Technical Derivation of Heat Transfer Performance of the Airside of a Novel Pin Design Heat Exchanger Using Computational Fluid Dynamics

2012 ◽  
Author(s):  
Tosha Churitter
Keyword(s):  
Heat Transfer ◽  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Heat Exchanger ◽  
Mass Flow ◽  
Heat Exchangers ◽  
Heat Transfer Performance ◽  
Diameter Ratio ◽  
Transfer Performance ◽  
Extended Surface

Pins are a common type of extended surface used in the field of heat transfer; their main application being in the electronics field. Historically, pins used in heat exchangers have diameters that are considered negligible in comparison to their lengths and are therefore termed as tubes. In this report, the use of pins as an extended surface is investigated for the heat transfer on the airside (cold) of the Compact Advanced Pin Surface Heat Exchanger. The pins are circular in cross section and follow a staggered arrangement. The uniqueness of the pin design is such that they cannot be treated as tubes. Key Pin Design features are as follows: • Pins have a maximum Length: Diameter ratio of 3. • Pin Spacing to Pin Diameter ratio is greater than in traditional arrangements. • Pins function as a primary as well as secondary surface. The heat transfer performance of extended surfaces possessing the above features has not been characterized, using commercially available Computational Fluid Dynamics (CFD) software, in any research specifically focused on applications for the aerospace industry. Based on actual test results, this study specially develops a unique approach that can predict the outlet temperature of the heat exchanger to within 1% accuracy. This ‘developed’ approach is applied over cold-side mass flow rates ranging from 0.05 kg/s to 0.23 kg/s, while keeping the hot side mass flow rate constant at 0.05 kg/s. At worst, the simulation results lie within 5% accuracy and at best the simulation accuracy is 1%, a significant improvement on traditional derivations. This article specifically discusses the methodology developed to analyse the heat transfer performance of the novel pin design using Fluent 6.2. It highlights the current limitations of existing equations as well as the theoretical knowledge gap that currently exists in the analysis of pins as extended heat transfer surfaces in heat exchangers.

Experimental and computational fluid dynamics modeling of a novel tray humidifier column in humidification dehumidification desalination; evaluation of hydrodynamic and heat transfer characteristics

2020 ◽  
Vol 234 (3) ◽  
pp. 275-284
Author(s):  
Taleb Zarei ◽  
Reza Hamidi Jahromi ◽  
Arash Mohammadi Karachi
Keyword(s):  
Heat Transfer ◽  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Rectangular Cross Section ◽  
Seawater Temperature ◽  
Operating Conditions ◽  
Dynamics Modeling ◽  
Heat Transfer Characteristics ◽  
Computational Fluid Dynamics Modeling ◽  
Transfer Characteristics

In this article, a novel tray humidifier column for humidification dehumidification desalination was proposed. The performance of the humidifier column has been investigated with experimental and computational fluid dynamics simulations. The hydrodynamics and heat transfer characteristics of this tray humidifier has been studied. A stainless steel sieve tray with a rectangular cross section with a dimension of 20 × 50 cm was used in the experimental study. In computational fluid dynamics modeling, a transient three-dimensional model has been developed based on the volume of fluid framework by using standard k-epsilon model. The effect of air and seawater flow rate and inlet seawater temperature on the exit air temperature has been investigated. The results show that the humidifier effectiveness of the tray humidifier column varies between 0.67 and 0.87 depending on operating conditions. Then, tray column can be used in humidification dehumidification desalination systems with advantages such as compact equipment, low-pressure drop, and handling solids or other sources of fouling.

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