Numerical Development of a Coupled 1D/3D CFD Method for Thermal Analysis with Flow Maldistribution

2020 ◽  
pp. 1-13
Author(s):  
Haimi Jordaan ◽  
P.S. Heyns ◽  
Siamak Hoseinzadeh
Keyword(s):  
Polynomial Regression ◽  
Fluid Dynamic ◽  
Transient Temperature ◽  
Cfd Analysis ◽  
Mapping Procedure ◽  
One Dimensional ◽  
Tube Heat Exchanger ◽  
Tube Bundles ◽  
Shell And Tube ◽  
Cfd Method

Abstract This work describes the development of a methodology that couples one-dimensional (1D) network elements with three-dimensional (3D) spatial computational fluid dynamic (CFD) elements to analyse shell-and-tube heat exchangers with dense tube bundles. The one-dimensional (1D) elements represent the tube flow while the spatial elements represent the external auxiliary flow. This reduces the computational expense significantly as compared to full CFD analysis of the same system, whilst a detailed transient temperature distribution can still be obtained. The methodology uses a unique combination of relaxation algorithms, a polynomial regression mapping procedure, and discretisation methods to create a coherent numerical methodology. Simulations are performed on a TEMA-FU type shell-and-tube heat exchanger. The methodology was validated against full CFD and indicates errors between the calculated logarithmic mean temperature differences (LMTD) of less than 2% over a range of turbulent flow conditions. Various combinations of media for primary and auxiliary fluids are considered, to test the applicability and robustness of the methodology. Finally, a transient simulation of timed step inputs for the flow rate and temperature of both primary and auxiliary fluids, also corresponds with a full CFD analysis. It is concluded that the proposed 1D-CFD method is effective for simplifying the analysis of flow through tube bundles.

Experimental and Numerical Studies of Shell-and-Tube Heat Exchangers With Helical Baffles

2009 ◽  
Author(s):  
Guidong Chen ◽  
Qiuwang Wang
Keyword(s):  
Heat Transfer ◽  
Nusselt Number ◽  
Friction Factor ◽  
Fluid Dynamic ◽  
Thermal Design ◽  
Number Range ◽  
Tube Heat Exchanger ◽  
Nusselt Numbers ◽  
Shell And Tube ◽  
Cfd Method

In the present paper, flow and heat transfer characteristics of shell-and-tube heat exchanger with continuous helical baffles (CH-STHX) is experimentally studied. Correlations for heat transfer and pressure drop, which are estimated by Nusselt number and friction factor, are fitted by experiment data for thermal design. Computational Fluid Dynamic (CFD) method is also used to compare the heat transfer and flow performance of STHX with continuous helical baffles (CH-STHX), STHX with combined helical baffles (CMH-STHX) and STHX with discontinuous helical baffles (DCH-STHX). The numerical results show that, for the same Reynolds number, the Nusselt numbers Nuo of the CMH-STHX and CH-STHX is about 37.6%, 78.2% higher than that of the DCH-STHX; the friction factor fo of the CH-STHX is about 14.8% and 150.2% higher than that of CMH-STHX and DCH-STHX. If the velocity ratios RCMH, CH and RDCH, CH are bigger than 1.55 and 4.0 in the Nusselt number range from 40 to 70, the CMH-STHX and the DCH-STHX may have higher Nusselt numbers than the CH-STHX for the same mass flow rate in the shell side.

scholarly journals Heat transfer rates in hot shell, cold tube inclined baffled small shell, and tube heat exchanger using CFD and experimental approach

2021 ◽  
Vol 9 (4B) ◽  
Author(s):  
Devanand D. Chillal ◽  
◽  
Uday C. Kapale ◽  
N.R. Banapurmath ◽  
T. M. Yunus Khan ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Heat Exchanger ◽  
Liquid Flow ◽  
Cfd Analysis ◽  
Transfer Coefficients ◽  
Transfer Rates ◽  
Tube Heat Exchanger ◽  
Heat Transfer Coefficients ◽  
Shell And Tube ◽  
Cold Liquid

The work presented is an effort to realize the changes occurring for convective coefficients of heat transfer in STHX fitted with inclined baffles. Effort has been undertaken using Fluent, a commercially available CFD code ona CAD model of small STHX with inclined baffles with cold liquid flowing into the tubes and hot liquid flowing in the shell. Four sets of CFD analysis have been carried out. The hot liquid flow rate through shell compartments varied from 0.2 kg/sec to 0.8 kg/sec in steps of 0.2 kg/sec, while keeping the cold liquid flow condition in tube at 0.4 kg/sec constant. Heat transfer rates, compartment temperatures, and overall heat transfer coefficients, for cold liquid and hot liquid, were studied. The results given by the software using CFD approach were appreciable and comparatively in agreement with the results available by the experimental work, which was undertaken for the same set of inlet pressure conditions, liquid flow rates, and inlet temperatures of liquid for both hot and cold liquids. The experimental output results were also used to validate the results given by the CFD software. The results from the CFD analysis were further used to conclude the effect of baffle inclination on heat duty. The process thus followed also helped realize the effects of baffle inclination on convective heat transfer coefficient of the liquid flow through the shell in an inclined baffle shell and tube heat exchanger. The temperature plots for both cold and hot liquid were also generated for understanding the compartmental temperature distributions inclusive of the inlet and outlet compartments. The heat duty for a heat exchanger has been found to increase with the increase in baffle inclinations from zero degree to 20 degrees. Likewise, the convective heat transfer coefficients have also been found to increase with the increase in baffle inclinations.

Numerical Studies of a Novel Combined Multiple Shell-Pass Shell-and-Tube Heat Exchanger With Helical Baffles

2008 ◽  
Author(s):  
Qiuwang Wang ◽  
Guidong Chen ◽  
Qiuyang Chen ◽  
Min Zeng ◽  
Dahai Zhang
Keyword(s):  
Heat Transfer ◽  
Pressure Drop ◽  
Heat Transfer Rate ◽  
Transfer Rate ◽  
Industrial Applications ◽  
The Novel ◽  
Tube Heat Exchanger ◽  
Shell And Tube ◽  
Save Energy ◽  
Cfd Method

In order to simplify the manufacture and improve heat transfer performance of shell-and-tube heat exchangers (STHXs), we have invented a combined multiple shell-pass STHX with continuous helical baffles. The novel combined multiple shell-pass STHX with continuous helical baffles (NOVEL STHX) is compared with the conventional STHX with segmental baffles by Computational Fluid Dynamics (CFD) method. The numerical results show that, under the same mass flow rate M and the same overall heat transfer rate Qm in the shell side, the overall pressure drop DP of the NOVEL STHX is lower than that of the STHX with segmental baffles by about 13%. The heat transfer rate Qm of the NOVEL STHX is higher than that of the STHX with segmental baffles by about 6% under the same overall pressure drop DP. The NOVEL STHX might be used to replace the conventional STHX with segmental baffles in industrial applications to save energy, reduce cost and prolong service life.

scholarly journals Optimization Performance on Plate Fin Tube Heat Exchanger

2019 ◽  
Vol 5 (3) ◽  
pp. 10
Author(s):  
Mahtab Alam ◽  
Dr. Dharmendra Singh Rajput
Keyword(s):  
Heat Transfer ◽  
Heat Exchanger ◽  
Circular Tube ◽  
Fluid Dynamic ◽  
Cfd Analysis ◽  
Maximum Heat ◽  
Tube Heat Exchanger ◽  
Tube Arrangement ◽  
Maximum Heat Transfer ◽  
Fin Tube

The main objective of the present work is to investigation of optimum design of plate fin tube heat exchanger using Computational fluid dynamic approach and maximizing thermal performance. There are total five designs of plate fin and tube heat exchanger are used in present work and CFD analysis have been performed in it to get maximum heat transfer. It has been observed from CFD analysis that the maximum heat transfer can be achieved from plate fin and tube heat exchanger with elliptical tube arrangement inclined at 30o with 23.22% more heat transfer capacity as compared to circular tube plate pin heat exchanger. So that it is recommended that if the plate fins and tube heat exchanger with inclined elliptical tube used in place of circular tube arrangement, batter heat transfer can be achieved.

scholarly journals Streamline characteristics using the computational fluid dynamic analysis in the flow of 18% EDTA irrigation solution to remove Ca(OH)2

2019 ◽  
Vol 4 (2) ◽  
pp. 67
Author(s):  
Anna Muryani ◽  
Hendra Dian Adhita Dharsono ◽  
Z. Zuleika ◽  
Ing. Mochammad Agoes Moelyadi ◽  
Diani Prisinda
Keyword(s):  
Experimental Research ◽  
Root Canal ◽  
Fluid Dynamic ◽  
Cfd Analysis ◽  
Canal Wall ◽  
Low Velocity ◽  
Computational Fluid Dynamic Analysis ◽  
Irrigation Flow ◽  
Irrigation Solution ◽  
Cfd Method

The remaining calcium hydroxide (Ca(OH)2) medicaments in the root canal wall can block the penetration of filling medicaments to the dentine tubule and cause the failure in the root canal treatment. One of the ways in cleaning the root canal wall from the remains of (Ca(OH)2) is by using 18% Ethylene Diamine Tetra Acetic Acid (EDTA) irrigation solution. The cleanliness of the root canal can be examined using the Computational Fluid Dynamics (CFD) analysis. The aim of this research was to see the description of the cleanliness of the root canal wall from the (Ca(OH)2) medicament with 18% EDTA irrigation by means of CFD analysis. This is a descriptive-explorative research. Having been validated with the experimental research using test specimen in the form of block resin made in accordance with the characteristics of root canal, the description of the cleanliness of the root canal wall from the (Ca(OH)2) medicament with the 18% EDTA irrigation was analyzed using CFD method. The irrigation needle used was the side-vented type with the position of 3 mm from the tooth apical. The results of the research showed the conformity between the result of experimental research and CFD research. One of the results of this research was the characteristics of streamline of 18% EDTA in the root canal showing a unique behavior due to the characteristics of the form of side vent irrigation needle. The irrigation flow in the coronal area of the inlet (side vent irrigation needle) showed a low velocity causing the more fluid flowing out from the inlet went to apical rather to the outlet (root canal orifice). In conclusion, this research showed that 18% EDTA solution indicated the conformity of validation results between experimental research and CFD research in the frames of 5, 10, 15, and 20 secs observed from experimental research with the of frame 0,010, 0,099, 0,150 and 0,410 secs as observed from CFD research.

scholarly journals Modeling and Performance Analysis of AC Plant Heat Exchanger

2021 ◽  
Vol 7 (09) ◽  
pp. 35-40
Author(s):  
V. Harika and Dr. K. Vasantha Kumar
Keyword(s):  
Heat Exchanger ◽  
Electrical Energy ◽  
Cfd Analysis ◽  
Tube Heat Exchanger ◽  
Pressure Application ◽  
Flow Heat ◽  
Shell And Tube ◽  
And Performance ◽  
Work Effect

AC plant Chiller is considered as a shell-and-tube heat exchanger and generally applied in a water-cooled chiller. These days shell and tube heat exchanger (STHX) is the most common type of heat exchanger broadly used in marine ships, due to its high pressure application. The AC plants fitted on-board Marine ships consist of a Chiller i.e. parallel flow heat exchanger with baffles. It is important to improve the performance of a chiller so that the usage of electrical energy can be reduced while the quality of a product can be increased. The water is cooled by using refrigerant in this chiller. This project mainly deals with modeling the prototype of basic geometry of shell and tube heat exchanger using Solidworks and meshing using simulation run using CFD package ANSYS. In this paper, by varying the number of baffles and different fluids they are water, R134a and R410a their performance of the chiller is studied. In this work, effect of the baffle spacing on the performance of a heat exchanger has been examined. Thermal and fatigue analysis is done in ANSYS for two materials Aluminum and Copper for better fluid at from CFD analysis.

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