scholarly journals Performance Evaluation of Concentric Triple Tube Heat Exchanger by using CFD

2021 ◽  
pp. 1-10
Author(s):  
Mr Suryakant ◽  
Shravan Vishwakarma ◽  
Jitendra Mishra
Keyword(s):  
Heat Exchanger ◽  
Heat Flow ◽  
Creep Condition ◽  
Propagation Speed ◽  
Simple Calculation ◽  
Outer Side ◽  
Tube Heat Exchanger ◽  
Thermal Movement ◽  
The Impact ◽  
Pressure Factor

The main objective of this work is to design a concentric three-cylinder heat exchanger for better heat movement, using a sum of four expansions to verify its hot presentation under similar boundary conditions. For this reason, the second creep condition is specified for robust dividers where the heat flow for the outer side divider is concentrated to achieve an adiabatic state while the dividers and inner vanes of the cylinder are coupled. The deltas for the outside and inside of the line are characterized as mass flow trees; The power source is marked as an outlet with a pressure factor. Flow programming is used to determine the movement of liquid and heat flow in the measurement zones. The applicable conditions are governed iteratively by the limited volume details with the SIMPLE calculation. The RNG-k-epsilon model is used for storm currents because the impact of eddies on strong currents is more accurate than the standard k-epsilon model and the second booster graph method is used for the deflection of the eruptive energy and the its propagation speed. The results show that computer examination of the liquid elements of a concentric three-tube heat exchanger with inclined scales at 45 ° C provides the circulation temperature, the speed of heat movement, and, in general, a coefficient of thermal movement. more than 11.74% higher than sloped blades are at 30 ° C and 28.96% higher than straight stairs, 9mm high and 42.22% higher than three tube heat exchangers concentric fins.

Investigation of the impact of structural gaps on the hydrodynamics of the flow shell and tube heat exchanger

2019 ◽  
Author(s):  
V. N. Gushshamova ◽  
S. V. Mordanov ◽  
I. E. Shtyrlyaev
Keyword(s):  
Heat Exchanger ◽  
Tube Heat Exchanger ◽  
Shell And Tube ◽  
The Impact

Simulation Research of the Impact on the Heat Transfer Capability of Structural Changes in Tube Heat Exchanger

2011 ◽  
Vol 255-260 ◽  
pp. 1378-1382
Author(s):  
Bai Sheng Liao
Keyword(s):  
Heat Transfer ◽  
Heat Exchanger ◽  
Structural Changes ◽  
Ansys Software ◽  
Counter Flow ◽  
Simulation Research ◽  
Tube Heat Exchanger ◽  
Software Company ◽  
Transfer Capability ◽  
The Impact

This article apply the CFX computational fluid software of ANSYS software company to casing tube heat exchanger of inside diameter of 10mm, 16mm, wall thickness of 1mm, pipe sections of the counter-flow 1000mm long, including concentric and eccentric placement of three kinds of state and other conditions in different conducted, draw a conclusion that the speed of the fluid and temperature distribution in the tube, and compared the case of three kinds of heat transfer coefficient.

scholarly journals Thermal Calculations of Four-Row Plate-Fin and Tube Heat Exchanger Taking into Account Different Air-Side Correlations on Individual Rows of Tubes for Low Reynold Numbers

Energies ◽  
2021 ◽  
Vol 14 (21) ◽  
pp. 6978
Author(s):  
Mateusz Marcinkowski ◽  
Dawid Taler ◽  
Jan Taler ◽  
Katarzyna Węglarz
Keyword(s):  
Nusselt Number ◽  
Heat Exchanger ◽  
Heat Flow ◽  
Least Squares Method ◽  
Heat Output ◽  
Optimum Number ◽  
Heat Flow Rate ◽  
Cfd Modelling ◽  
Tube Heat Exchanger ◽  
Average Value

Currently, when designing plate-fin and tube heat exchangers, only the average value of the heat transfer coefficient (HTC) is considered. However, each row of the heat exchanger (HEX) has different hydraulic–thermal characteristics. When the air velocity upstream of the HEX is lower than approximately 3 m/s, the exchanged heat flow rates at the first rows of tubes are higher than the average value for the entire HEX. The heat flow rate transferred in the first rows of tubes can reach up to 65% of the heat output of the entire exchanger. This article presents the method of determination of the individual correlations for the air-side Nusselt numbers on each row of tubes for a four-row finned HEX with continuous flat fins and round tubes in a staggered tube layout. The method was built based on CFD modelling using the numerical model of the designed HEX. Mass average temperatures for each row were simulated for over a dozen different airflow velocities from 0.3 m/s to 2.5 m/s. The correlations for the air-side Nusselt number on individual rows of tubes were determined using the least-squares method with a 95% confidence interval. The obtained correlations for the air-side Nusselt number on individual rows of tubes will enable the selection of the optimum number of tube rows for a given heat output of the HEX. The investment costs of the HEX can be reduced by decreasing the tube row number. Moreover, the operating costs of the HEX can also be lowered, as the air pressure losses on the HEX will be lower, which in turn enables the reduction in the air fan power.

Air-Side Heat-Transfer Enhancement by a New Winglet-Type Vortex Generator Array in a Plain-Fin Round-Tube Heat Exchanger

2010 ◽  
Vol 132 (7) ◽  
Author(s):  
J. He ◽  
L. Liu ◽  
A. M. Jacobi
Keyword(s):  
Heat Transfer ◽  
Heat Exchanger ◽  
Vortex Generator ◽  
Round Tube ◽  
Number Range ◽  
Tube Heat Exchanger ◽  
Large Pair ◽  
Goodness Factor ◽  
The Impact ◽  
Heat Transfer Improvement

The impact of a vortex-generation technique for air-side heat-transfer improvement is experimentally investigated through full-scale wind-tunnel testing of a plain-fin round-tube heat exchanger under dry-surface conditions. Inspired by the formation locomotion of animals in nature, a new vortex generator (VG) array deployed in a “V” is proposed in the present work, aiming to create constructive interference between vortices. The array is composed of two delta-winglet pairs and placed at an attack angle of 10 deg or 30 deg. Its effectiveness is compared with a baseline configuration and two conventional single-pair designs placed at 30 deg, a small pair with half the area of the array and a large pair with the same area as the array. The frontal air velocity considered ranges from 2.3 m/s to 5.5 m/s, corresponding to a Reynolds number range based on the hydraulic diameter of 1400–3400. The experimental results show little impact of the 10 deg array and a moderate heat-transfer improvement of up to 32% for the small pair, both introducing additional pressure loss of approximately 20–40%. For the 30 deg array and the large pair, similar augmentation of 25–55% in air-side heat-transfer coefficient is obtained accompanied by average pressure drop penalties of 90% and 140%, respectively. Performance evaluation using the criteria of the modified area goodness factor and the volume goodness factor indicates the superiority of the heat exchanger enhanced by the 30 deg array among all the investigated VGs. The VG array is found more effective at comparatively low Reynolds numbers, representative of many heating, ventilation, air-conditioning, and refrigeration applications and compact heat-exchanger designs.

scholarly journals A Novel Heat Exchanger Design Method Using a Delayed Rejection Adaptive Metropolis Hasting Algorithm

2018 ◽  
Author(s):  
Javier Bonilla
Keyword(s):  
Heat Exchanger ◽  
Probability Distribution ◽  
Optimization Methods ◽  
Optimization Method ◽  
Total Annual Cost ◽  
Tube Heat Exchanger ◽  
Design Variables ◽  
Shell And Tube ◽  
Delayed Rejection ◽  
The Impact

In this study, a shell-and-tube heat exchanger (STHX) design based on seven continuous independent design variables is proposed. Delayed Rejection Adaptive Metropolis hasting (DRAM) was utilized as a powerful tool in the Markov chain Monte Carlo (MCMC) sampling method. This Reverse Sampling (RS) method was used to find the probability distribution of design variables of the shell and tube heat exchanger. Thanks to this probability distribution, an uncertainty analysis was also performed to find the quality of these variables. In addition, a decision-making strategy based on confidence intervals of design variables and on the Total Annual Cost (TAC) provides the final selection of design variables. Results indicated high accuracies for the estimation of design variables which leads to marginally improved performance compared to commonly used optimization methods. In order to verify the capability of the proposed method, a case of study is also presented, it shows that a significant cost reduction is feasible with respect to multi-objective and single-objective optimization methods. Furthermore, the selected variables have good quality (in terms of probability distribution) and a lower TAC was also achieved. Results show that the costs of the proposed design are lower than those obtained from optimization method reported in previous studies. The algorithm was also used to determine the impact of using probability values for the design variables rather than single values to obtain the best heat transfer area and pumping power. In particular, a reduction of the TAC up to 3.5% was achieved in the case considered.

scholarly journals Experimental Verification of an Analytical Mathematical Model of a Round or Oval Tube Two-Row Car Radiator

Energies ◽  
2020 ◽  
Vol 13 (13) ◽  
pp. 3399
Author(s):  
Dawid Taler ◽  
Jan Taler ◽  
Marcin Trojan
Keyword(s):  
Mathematical Model ◽  
Heat Exchanger ◽  
Heat Flow ◽  
Heat Exchangers ◽  
Cfd Simulation ◽  
Experimental Studies ◽  
Hot Water ◽  
Heat Flow Rate ◽  
Cfd Modelling ◽  
Tube Heat Exchanger

The paper presents an analytical mathematical model of a car radiator, which takes into account various heat transfer coefficients (HTCs) on each row of pipes. The air-side HTCs in a specific row of pipes in the first and second passes were calculated using equations for the Nusselt number, which were determined by CFD simulation by the ANSYS program (Version 19.1, Ansys Inc., Canonsburg, PA, USA). The liquid flow in the pipes can be laminar, transition, or turbulent. When changing the flow form from laminar to transition and from transition to turbulent, the HTC continuity is maintained. Mathematical models of two radiators were developed, one of which was made of round tubes and the other of oval tubes. The model allows for the calculation of the thermal output of every row of pipes in both passes of the heat exchangers. Small relative differences between the total heat flow transferred in the heat exchanger from hot water to cool air exist for different and uniform HTCs. However, the heat flow rate in the first row is much higher than the heat flow in the second row if the air-side HTCs are different for each row compared to a situation where the HTC is constant throughout the heat exchanger. The thermal capacities of both radiators calculated using the developed mathematical model were compared with the results of experimental studies. The plate-fin and tube heat exchanger (PFTHE) modeling procedure developed in the article does not require the use of empirical correlations to calculate HTCs on both sides of the pipes. The suggested method of calculating plate-fin and tube heat exchangers, taking into account the different air-side HTCs estimated using CFD modelling, may significantly reduce the cost of experimental research for a new design of heat exchangers implemented in manufacturing.

scholarly journals Heat Transfer Characteristics of Inclined Helical Coil Tube by Forced and Free Convection : A Review

2020 ◽  
pp. 322-328
Author(s):  
Sagar S. Gaddamwar ◽  
Rajeshkumar U. Sambhe
Keyword(s):  
Heat Transfer ◽  
Heat Exchanger ◽  
Thermal Power ◽  
Relative Advantage ◽  
Outer Side ◽  
Helical Coil ◽  
Straight Tube ◽  
Tube Heat Exchanger ◽  
Heat Transfer Augmentation ◽  
Augmentation Techniques

Aim of this review work is to examine the relative advantage of using an inclined helical coil tube heat exchanger for high-pressure syngas under various industries application. It observed that the heat transfer in the helical coil tube is higher as compared to the straight tube due to their shape. Inclined helical coil tube heat exchanger offers advantageous over straight tubes due to their compactness and increased heat transfer coefficient. The increased heat transfer coefficients are a consequence of the curvature of the coil, which induces centrifugal forces to act on the moving syngas. Due to the curvature effect, the fluid streams in the outer side of the pipe moves faster than the syngas streams on the inner side of the tube. Heat transfer augmentation techniques refer to various methods used to increase the heat transfer rate without changing much the overall performance of the system. The arrangements are useful in a variety of applications where more heat transfer rates desired. Some of the claims involved in heat exchanger used in Thermal Power plants, process industries, air-conditioning equipment, heating and cooling in evaporators, radiators for space vehicles, automobiles, refrigerators. These techniques broadly of three types viz. passive, active, compound heat transfer augmentation techniques. The present paper reviews the experimental investigation of free and forced convection heat transfer from different helical coiled tubes.

scholarly journals The CFD Based Method for Determining Heat Transfer Correlations on Individual Rows of Plate-Fin and Tube Heat Exchangers

2021 ◽  
Author(s):  
Dawid Taler ◽  
Jan Taler ◽  
Marcin Trojan
Keyword(s):  
Heat Transfer ◽  
Mathematical Model ◽  
Heat Exchanger ◽  
Heat Flow ◽  
Heat Exchangers ◽  
Cfd Simulation ◽  
Cfd Modeling ◽  
Transfer Coefficients ◽  
Tube Heat Exchanger ◽  
The Cost

The chapter provides an analytical mathematical model of a car radiator, which includes different heat transfer coefficients (HTCs) on the first and second row of pipes. The air-side HTCs in the first and second row of pipes in the first and second pass were calculated using the correlations for the Nusselt number, which were determined by CFD simulation using the ANSYS software. Mathematical models of two radiators were built, one of which was manufactured of round tubes and the other of oval tubes. The model permits the determination of thermal output of the first and second row of tubes in the first and second pass. The small relative differences between the thermal capacities of the heat exchanger occur for different and uniform HTCs. However, the heat flow rate in the first row is much greater than the heat flow in the second row if the air-side HTCs are different on the first and second tube row compared to a case where the HTC is uniform in the whole heat exchanger. The heat transfer rates in both radiators calculated using the developed mathematical model were compared with those determined experimentally. The method for modeling of plate-fin and tube heat exchanger (PFTHE) proposed in the paper does not require empirical correlations to calculate HTCs both on the air side and on the inner surfaces of pipes. The presented method of calculating PFTHEs, considering different air-side HTCs evaluated using CFD modeling, may considerably reduce the cost of experimental research concerning new design heat exchangers implemented in manufacturing.

APPLICATION OF ENTROPY GENERATION MINIMIZATION FOR OPTIMIZING THE GEOMETRY OF A DOUBLE-TUBE HEAT EXCHANGER

2017 ◽  
Vol 48 (11) ◽  
pp. 955-968
Author(s):  
Rafal Laskowski ◽  
Pawel Tomczak ◽  
Maciej Jaworski
Keyword(s):  
Heat Exchanger ◽  
Entropy Generation ◽  
Tube Heat Exchanger ◽  
Entropy Generation Minimization
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