scholarly journals Mathematical Model of Heat Transfer for a Finned Tube Cross-flow Heat Exchanger with Ice Slurry as Cooling Medium

2016 ◽  
Vol 146 ◽  
pp. 513-522 ◽  
Author(s):  
Youwei Long ◽  
Shugang Wang ◽  
Jihong Wang ◽  
Tengfei Zhang
Keyword(s):  
Heat Transfer ◽  
Mathematical Model ◽  
Heat Exchanger ◽  
Cross Flow ◽  
Finned Tube ◽  
Ice Slurry ◽  
Cooling Medium ◽  
Flow Heat

scholarly journals Fluid flow consideration in fin-tube heat exchanger optimization

2010 ◽  
Vol 31 (3) ◽  
pp. 87-104 ◽  
Author(s):  
Piotr Wais
Keyword(s):  
Heat Transfer ◽  
Fluid Flow ◽  
Heat Exchanger ◽  
Mass Flow ◽  
Cross Flow ◽  
Finned Tube ◽  
Tube Heat Exchanger ◽  
Flow Heat ◽  
The Cross ◽  
Fin Tube

Fluid flow consideration in fin-tube heat exchanger optimizationThe optimization of finned tube heat exchanger is presented focusing on different fluid velocities and the consideration of aerodynamic configuration of the fin. It is reasonable to expect an influence of fin profile on the fluid streamline direction. In the cross-flow heat exchanger, the air streams are not heated and cooled evenly. The fin and tube geometry affects the flow direction and influences temperature changes. The heat transfer conditions are modified by changing the distribution of fluid mass flow. The fin profile impact also depends on the air velocity value. Three-dimensional models are developed to find heat transfer characteristics between a finned tube and the air for different air velocities and fin shapes. Mass flow weighted average temperatures of air volume flow rate are calculated in the outlet section and compared for different fin/tube shapes in order to optimize heat transfer between the fin material and air during the air flow in the cross flow heat exchanger.

scholarly journals PRACTICAL STUDY TO IMPROVEMENT THE PERFORMANCE OF HEAT EXCHANGER USING PASSIVE TECHNIQUES

2020 ◽  
Vol 6 (8) ◽  
pp. 21-33
Author(s):  
Farah Abdulzahra Taher ◽  
Zena Khalefa Kadhim
Keyword(s):  
Heat Transfer ◽  
Heat Transfer Coefficient ◽  
Heat Exchanger ◽  
Transfer Coefficient ◽  
Flow Rate ◽  
Water Flow Rate ◽  
Cross Flow ◽  
Finned Tube ◽  
Water Stream ◽  
Flow Heat

The aim of this study to improve the performance of heat exchanger by using the medium integral fins on the cross flow heat exchanger practically, so, two the heat exchangers from copper were manufactures with eight passes for comparison under different boundary conditions. The water flow rate flow inner the tubes with (2, 3, 4, 5, 6) L/min with inlet temperatures (50, 60, 70) oC, as for the air flow rate were passed outer the tubes by speeds (1, 1.7, 2.3) m/sec. The results show that the medium integral finned tube gives more improvement the heat transfer than the smooth tube about 203.97% and 205.1% was enhancement factor. Motivation: The aim is improvement the heat transfer coefficient for cross flow heat exchanger by using medium integral finned tube. Study the effect of various water stream rate, air speed and inlet water temperature on heat transfer coefficient for them, Finding the cases which enhanced heat transfer for various ranges of air and water as well as inlet temperatures and the speed at the entrance. Develop the empirical correlations for (Nua) of smooth and medium integral finned tubes as function of (Pra) and (Rea).

Experimental Investigation of Heat Transfer Enhancement by Using Different Number of Fins in Circular Tube

2018 ◽  
Vol 6 (3) ◽  
pp. 1-12
Author(s):  
Kamil Abdul Hussien
Keyword(s):  
Heat Transfer ◽  
Heat Exchanger ◽  
Cold Water ◽  
Finned Tube ◽  
Hot Water ◽  
Copper Tube ◽  
Smooth Tube ◽  
Tube Heat Exchanger ◽  
Mass Flow Rates ◽  
Flow Heat

Abstract-The present work investigates the enhancement of heat transfer by using different number of circular fins (8, 10, 12, 16, and 20) in double tube counter flow heat exchanger experimentally. The fins are made of copper with dimensions 66 mm OD, 22 mm ID and 1 mm thickness. Each fin has three of 14 mm diameter perforations located at 120o from each to another. The fins are fixed on a straight smooth copper tube of 1 m length, 19.9 mm ID and 22.2 mm OD. The tube is inserted inside the insulated PVC tube of 100 mm ID. The cold water is pumped around the finned copper tube, inside the PVC, at mass flow rates range (0.01019 - 0.0219) kg/s. The Reynold's number of hot water ranges (640 - 1921). The experiment results are obtained using six double tube heat exchanger (1 smooth tube and the other 5 are finned one). The results, illustrated that the heat transfer coefficient proportionally with the number of fin. The results also showed that the enhancement ratio of heat transfer for finned tube is higher than for smooth tube with (9.2, 10.2, 11.1, 12.1 13.1) times for number of fins (8, 10, 12, 16 and 20) respectively.

Exact Solution to the Governing PDE of a Hot Water-to-Air Finned Tube Cross-Flow Heat Exchanger

2004 ◽  
Vol 10 (1) ◽  
pp. 21-31 ◽  
Author(s):  
Chris Delnero ◽  
Dave Dreisigmeyer ◽  
Douglas Hittle ◽  
Peter Young ◽  
Charles Anderson ◽  
...  
Keyword(s):  
Exact Solution ◽  
Heat Exchanger ◽  
Cross Flow ◽  
Finned Tube ◽  
Hot Water ◽  
Flow Heat

scholarly journals The Effect of Flowrate and Effectiveness on Theoretical Design and Thermal Characteristic of a GHE

2018 ◽  
Vol 225 ◽  
pp. 01023
Author(s):  
T.M. Yusof ◽  
M.F. Basrawi ◽  
A. Shahrani ◽  
H. Ibrahim
Keyword(s):  
Heat Transfer ◽  
Heat Exchanger ◽  
Thermal Characteristic ◽  
Variable Parameter ◽  
Cross Flow ◽  
Outlet Temperature ◽  
Performance Study ◽  
Commercial Unit ◽  
Hot Climate ◽  
Flow Heat

Ground heat exchanger is an exciting technique to reduce energy consumption in building especially in hot climate countries. Implementation of GHE for commercial unit in Malaysia is almost none in record. Thus, performance study of the GHE in Malaysia is crucial to be conducted either experimentally or numerically. Therefore, this paper presents the performance of GHE in term of effectiveness, outlet temperature and rate of heat transfer based on mathematical model. The model is developed based on cross flow heat exchanger with one fluid unmixed. There are two variable parameter used in the analysis which is effectiveness and flowrate of the air for 25 meter length of a PVC pipe. Three effectiveness values which is 0.8, 0.9 and 0.99 have been analysed in this study. Meanwhile, flowrate of air is ranging from 0.02 to 0.2 kg/s. Results show that flowrate at 0.02 kg/s gives great temperature reduction in the pipe compared with higher flowrate. However, flowrate of 0.2 kg/s produces higher cooling potential. Characteristic of the GHE for the rate of heat transfer with 80, 90 and 99 percent effectiveness also have been developed and it has been found that effectiveness of 0.9 provide good combination between flowrate and the rate of heat transfer for 25 meter length of the pipe

Performance Analysis of Multi-Pass Cross-Flow Heat Exchangers

2018 ◽  
Author(s):  
Kiran Lankalapalli ◽  
Ahmed ElSawy ◽  
Stephen Idem
Keyword(s):  
Heat Exchanger ◽  
Performance Analysis ◽  
Thermal Performance ◽  
Heat Exchangers ◽  
Cross Flow ◽  
Threshold Value ◽  
Finned Tube ◽  
Flow Heat ◽  
Rate Ratios ◽  
Side Flow

A steady state sensible performance analysis of multi-pass cross-flow finned-tube heat exchangers is reported. The investigation considers various flow circuiting, such as counter cross-flow, parallel cross-flow, and cross-flow where the tube-side flow is in parallel. A previously developed matrix approach is used to evaluate the heat exchanger performance in each tube pass. The equations required to model the thermal performance of these configurations are presented, and the thermal performance is compared for each type of flow circuiting. Thereafter a parametric study on cross-flow heat exchanger performance is performed by varying physically significant parameters such as number of transfer units (NTU) and capacity rate ratios, and the graphical results for each type of flow circuiting are presented both for both two-pass and three-pass arrangements. A consistent criterion is proposed for each case, wherein increasing the NTU beyond a certain threshold value does not significantly improve heat exchanger thermal performance.

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