scholarly journals Development of evaporative intercooler heat exchanger for vehicle charge air enhancement using CFD simulation

2019 ◽  
Vol 13 (4) ◽  
pp. 6195-6217
Author(s):  
Pshtiwan M. Sharif ◽  
A. Aziz Hairuddin ◽  
Azizan As'ary ◽  
Khairil Anas Md Rezali ◽  
M. M. Noor ◽  
...  
Keyword(s):  
Heat Exchanger ◽  
Pressure Drop ◽  
Cfd Simulation ◽  
Engine Performance ◽  
Cooling Capacity ◽  
Tube Length ◽  
Cooling Load ◽  
Shell Size ◽  
Flexibility Design ◽  
Geometry Configuration

Nowadays, the concern of vehicle manufacturers towards improving engine performance, reducing fuel consumption and exhaust emissions that can cause the pollution of the atmosphere, concerns of strict emission pollution control regulations. Intercooler heat exchanger devices are used for engine charge air temperature improving for engine performance and emissions reduction. This paper introduces a new add-on technology of intercooler heat exchanger- (IHE) developed for utilizing in intake charge air density enhancement in engine combustion for better performance. Presenting a challenge in contributing a framework process for geometry designing development procedure for accurate and reliable scale design size of an air-vapour gas shell-and-tube IHE type, used refrigerant coolant medium. The process presents effective IHE in design time consumption, accurate in scale with higher performance and reliability operation in all environment weather due to reversibility system. A selected design geometry of 60 bunches of tubes with 7.53 mm inner diameter and 150 mm long placed. Effectiveness and design parameter geometry calculation are conditions of the IHE dependent relations of the shell size to tube length in condition of engine space availability control. Pressure drop and cooling capacity of IHE configuration design are proportional to the availability of design space or pressure drop control by the engine. Numerical and simulation results expressed a significant ability of IHE of 2–13 kW cooling load and process applicability for qualified design geometry configuration for selected IHE type. The developments present significant geometry flexibility design with the ability of cooling load or heating effect if reversible system, which offered multipurpose use in widely all vehicle types.

CFD Simulation of Fin-and-Tube Heat Exchanger with Louvered Fin Configuration: Technical Note

2017 ◽  
Vol 9 (3) ◽  
Author(s):  
M. Sabari ◽  
D. Channankiah ◽  
D. Shivalingappa
Keyword(s):  
Heat Transfer ◽  
Heat Exchanger ◽  
Pressure Drop ◽  
Cfd Simulation ◽  
Calculated Data ◽  
Technical Note ◽  
Operating Conditions ◽  
Tube Heat Exchanger ◽  
Louvered Fin ◽  
Almost All

Heat exchanger plays a major role in almost all mechanical industries. Enhancement of heat transfer surface plays major role in numerous applications such as in heat exchangers, refrigeration and air conditioning systems etc. This paper examines the fluid flow and heat exchange on the air side of a multi-row fin-and-tube heat exchanger. A brief comparison is given between fin-and-tube heat exchanger attributes with louvered fins in a wider range of operating conditions defined by inlet air velocities. The brief representation on the calculated data for the louvered heat exchanger shows better heat transfer characteristics with a slightly higher pressure drop. The CFD procedure is validated by comparing the numerical simulation results with different inlet air velocities. Best combination of higher heat transfer and minimum pressure drop are occurred in inlet air velocity of 2.5 m/s.

Principles of Refrigerant Circuiting in Single Row Microchannel Evaporators

2013 ◽  
Author(s):  
Sunil Mehendale
Keyword(s):  
Heat Transfer ◽  
Heat Exchanger ◽  
Pressure Drop ◽  
Predictive Ability ◽  
Element Model ◽  
Cooling Capacity ◽  
Fixed Number ◽  
Wide Range ◽  
First Pass ◽  
Louvered Fin

Microchannel evaporators are being increasingly considered for application in residential and commercial cooling and heat pump applications. This work analyzes the principles of refrigerant circuiting design in refrigerant-to-air heat exchangers using an element-by-element model developed for a microchannel evaporator. Geometric parameters such as microchannel tube depth, tube height, and port size, louvered fin density, louver angle, louver height, louver pitch, and fin height, as well as the air side face velocity, the refrigerant pressure-drop and heat transfer as a function of refrigerant mass flux are considered in the analysis. The model was first validated using data available in the open literature, thus providing a high level of confidence in the predictive ability of the model. Starting with a given microchannel tube and louvered fin geometry and a fixed number of tubes (and fins), the thermal performance of the heat exchanger was simulated over a wide range of two pass circuit configurations and tube lengths. It was found that the heat transfer versus pressure-drop trade-off provides an optimum relationship between the fraction of tubes in the first pass and the heat exchanger length. The sensitivity of the evaporator cooling capacity to the percentage of tubes in the first pass was also explored.

scholarly journals Numerical Simulation of the Performance Characteristics of the Hybrid Closed Circuit Cooling Tower

2008 ◽  
Vol 13 (1) ◽  
pp. 89-101 ◽  
Author(s):  
M. M. A. Sarker ◽  
E. Kim ◽  
G. C. Moon ◽  
J. I. Yoon
Keyword(s):  
Pressure Drop ◽  
Experimental Measurement ◽  
Cooling Tower ◽  
Cfd Simulation ◽  
Air Flow ◽  
Flow Distribution ◽  
Cooling Capacity ◽  
Performance Characteristics ◽  
Closed Circuit ◽  
Flow Rates

The performance characteristics of the Hybrid Closed Circuit Cooling Tower (HCCCT) have been investigated applying computational fluid dynamics (CFD). Widely reported CFD techniques are applied to simulate the air-water two phase flow inside the HCCCT. The pressure drop and the cooling capacity were investigated from several perspectives. Three different transverse pitches were tested and found that a pitch of 45 mm had lower pressure drop. The CFD simulation indicated that when air is supplied from the side wall of the HCCCT, the pressure drop can be over predicted and the cooling capacity can be under predicted mainly due to the non-uniform air flow distribution across the coil bank. The cooling capacity in wet mode have been calculated with respect to wet-bulb temperature (WBT) and cooling water to air mass flow rates for different spray water volume flow rates and the results were compared to the experimental measurement and found to conform well for the air supply from the bottom end. The differences of the cooling capacity and pressure drop in between the CFD simulation and experimental measurement in hybrid mode were less than 5 % and 7 % respectively for the uniform air flow distribution.

CFD Simulation of an Alfa-Stirling Engine to Study the Geometrical Parameters on the Engine Performance

2019 ◽  
Author(s):  
Ana C. Ferreira ◽  
Senhorinha F. C. F. Teixeira ◽  
Ricardo F. Oliveira ◽  
José C. Teixeira
Keyword(s):  
Heat Exchanger ◽  
Power Output ◽  
Cfd Simulation ◽  
Engine Performance ◽  
Stirling Engine ◽  
Operating Conditions ◽  
Design Parameters ◽  
Working Fluid ◽  
Cold Temperatures ◽  
Temperature Heat

Abstract An alpha-Stirling configuration was modelled using a Computational Fluid Dynamic (CFD), using ANSYS® software. A Stirling engine is an externally heated engine which has the advantage of working with several heat sources with high efficiencies. The working gas flows between compression and expansion spaces by alternate crossing of, a low-temperature heat exchanger (cooler), a regenerator and a high-temperature heat exchanger (heater). Two pistons positioned at a phase angle of 90 degrees were designed and the heater and cooler were placed on the top of the pistons. The motion of the boundary conditions with displacement was defined through a User Defined Function (UDF) routine, providing the motion for the expansion and compression piston, respectively. In order to define the temperature differential between the engine hot and the cold sources, the walls of the heater and cooler were defined as constant temperatures, whereas the remaining are adiabatic. The objective is to study the thermal behavior of the working fluid considering the piston motion between the hot and cold sources and investigate the effect of operating conditions on engine performance. The influence of regenerator matrix porosity, hot and cold temperatures on the engine performance was investigated through predicting the PV diagram of the engine. The CFD simulation of the thermal engine’s performance provided a Stirling engine with 760W of power output. It was verified that the Stirling engine can be optimized when the best design parameters combination are applied, mostly the regenerator porosity and cylinders volume, which variation directly affect the power output.

Numerical Simulation of the Flow Boiling Heat Transfer Performance of R134a in a Microchannel Evaporator With Louvered Fins

2011 ◽  
Author(s):  
Justin J. Gossard ◽  
Andrew D. Sommers
Keyword(s):  
Heat Transfer ◽  
Heat Exchanger ◽  
Pressure Drop ◽  
Heat Exchangers ◽  
Flow Boiling ◽  
Control Volume ◽  
Cooling Capacity ◽  
Heat Exchanger Design ◽  
Microchannel Tubes ◽  
Louvered Fins

The need for more compact and more efficient heat exchangers in the aerospace, automotive, and HVAC&R industries has led to the development of heat exchangers that utilize minichannel or microchannel tubes coupled with louvered fins. Minichannel and microchannel heat exchangers exhibit enhanced heat transfer with a minimal increase in pressure drop over conventional round tube, plain fin heat exchangers often with a significant reduction in the required refrigeration charge and overall heat exchanger size. This paper presents the development and validation of a finite volume, steady-state evaporator model to be used as an aid in heat exchanger design and analysis. The model focuses on evaporator geometries that include minichannel and microchannel tubes with louvered fins and headers. Multiple published correlations provide the user with options for calculating the air-side and refrigerant-side heat transfer and pressure drops within the control volume. Once the model was validated, it was then briefly used to study the effects of maldistribution of refrigerant within the inlet headers on the cooling capacity and refrigerant side pressure drop.

Heat Transfer Characteristics of a Mini Channel Compact Heat Exchanger Using Copper Wire Spring Fins

2005 ◽  
Author(s):  
Yong-Bin Im ◽  
Ki-Taek Lee ◽  
Jong-Soo Kim Jon ◽  
Yoon-Hwan Choi
Keyword(s):  
Heat Transfer ◽  
Heat Exchanger ◽  
Pressure Drop ◽  
Capillary Tube ◽  
Copper Wire ◽  
Tube Length ◽  
Duct Flow ◽  
F Factor ◽  
Transfer Tube ◽  
Mini Channels

The heat transfer and pressure drop characteristics of compact heat exchangers having mini channels and copper wire spring fins are investigated experimentally. A copper capillary tube is used as heat transfer tube (length: 250 mm, inside diameter: 1.4 mm and wall thickness: 0.2 mm). The copper wire spring fin (CSF) is made of thin copper wire whose thickness is 0.5 mm and length is 8.4 m, respectively. The heat transfer area density of heat exchanger is 1,880 m2/m3. Water is employed inside the circular tube to transfer heat with air for convenience. The air flow entering into the test section is a fully developed duct flow and velocity is varied from 0.5 to 2.0 m/s with 0.5 m/s intervals. Based on the experimental data, heat transfer rate, pressure drop, f–factor and j–factor are investigated.

Numerical Study of Internally Finned Bayonet Tubes in a High Temperature Bayonet Tube Heat Exchanger With Inner and Outer Fins

2010 ◽  
Author(s):  
T. Ma ◽  
M. Lin ◽  
M. Zeng ◽  
Y. P. Ji ◽  
Q. W. Wang
Keyword(s):  
Heat Transfer ◽  
High Temperature ◽  
Heat Exchanger ◽  
Pressure Drop ◽  
Tube Length ◽  
Large Temperature ◽  
Tube Heat Exchanger ◽  
Temperature Environment ◽  
High Temperature Environment ◽  
Ultra High Temperature

A bayonet tube heat exchanger with fins being employed outside and inside outer tubes of bayonet-elements is recommended to be used in the ultra high temperature environment by our previous research, such as Externally Fired Combined Cycle and syngas production processes. The present study is concerned with the heat transfer and pressure drop characteristics in internally finned bayonet tubes. Two kinds of thermal boundary conditions applied to the model, i.e., constant wall temperature boundary and convective heat transfer boundary, are calculated and compared. Effects of different fluid flow patterns, inlet Reynolds number and tube length on the heat transfer and pressure drop characteristics are performed. Thermal stress is produced due to the large temperature difference between the inner and outer tube under ultra high temperature environment. Considering the safety of the heat exchanger, the alternative designs are suggested that there should be a small spacing between the inner fin and inner tube surface. The effects of various spacing on the heat transfer and pressure drop characteristics are discussed as well. Based on the results, the suitable spacing is proposed.

Critical Modeling & Exergy Analysis of Multi Phase Change Materials Storage System

2017 ◽  
Vol 13 (1) ◽  
Author(s):  
Seyedalireza Hosseininasab ◽  
Ebrahim Nemati Lay
Keyword(s):  
Heat Exchanger ◽  
Phase Change ◽  
Thermal Energy ◽  
Phase Change Materials ◽  
Exergy Analysis ◽  
Cfd Simulation ◽  
Storage System ◽  
Heat Transfer Fluid ◽  
Tube Length ◽  
Tube Heat Exchanger

AbstractUsing the phase change materials (PCMs) can help to store thermal energy as latent heat method in the multi PCMs storage system. In this research study, an analytical model has been developed for solar thermal storage system. An especial shell and tube heat exchanger is considered to heat exchange purpose. Double pipes have been used as tubes and PCMs allocated on the shell side of the double pipes for the heat exchanger. The hot heat transfer fluid (HTF) flows across the tube banks to charge the thermal energy storage system during the charging cycle. The thermal energy absorbed in PCMs while the HFT temperature reduced in the charging process. The heat exchanger tube length is function of HTF residence time then the equivalent length is defined in the presented model. The validity of the proposed model has been checked by comparison between the analytical results and numerical data obtained before using CFD simulation. The result shows that required times to melt of the PCMs for the presented study has the consistency of about 0.928 with CFD results in different PCMs melting percentages. Also the required time to melt of the PCMs for the presented study has the consistency of 0.915 with CFD results in different air inlet temperatures. Therefore the presented model can predict the system behavior also can apply for cascaded PCMs storage systems for exergy analysis.

scholarly journals Numerical Analysis of Heat Exchanger for Spray-Assisted Low-Temperature Desalination System

2020 ◽  
Vol 2020 ◽  
pp. 1-11
Author(s):  
Amour Othman Muhunzi ◽  
Yusufu Abeid Chande Jande ◽  
Revocatus Lazaro Machunda
Keyword(s):  
Heat Transfer ◽  
Heat Transfer Coefficient ◽  
Energy Consumption ◽  
Heat Exchanger ◽  
Pressure Drop ◽  
Low Temperature ◽  
Transfer Coefficient ◽  
Mass Flow ◽  
Tube Length ◽  
The Impact

A numerical study for heat exchanger for spray-assisted low-temperature desalination system is presented for an existing low-temperature desalination unit at Arusha Technical College. This is aimed at recognizing the effect of mass flow and physical parameters like tube layout (diameter and length) on the overall heat transferred and the pressure drop in the shell-and-tube heat exchanger (STHX), as well as the impact of these parameters on the heat transfer coefficient and the overdesign of the STHX. Also, the study provides a suitable mathematical model for the replacement of the current condensation unit which tends to reduce energy consumption by reducing some of the electrical components in the system. A Math CAD model was developed using the Delaware method to obtain the mentioned parameters. The results show that at 0.8 kg/s flow rate a maximum heat transfer coefficient of 23212 W/m2K is achieved in a minimum diameter of 10 mm within a maximum tube length of 1000 mm heat exchanger and the pressure drop seems to be very low in a range of 0.328-0.957 Pa from all configurations. The configuration with 1000 mm tube length and 10 mm diameter performed well on the mass flow of 0.3 kg/s-0.8 kg/s by providing a suitable overall heat transfer coefficient of 2306-2539 W/m2K, while 12.8 is a maximum overdesign coefficient achieved on 0.8 kg/s mass flow. The study results show the possibility of using STHX instead of the current condensation unit in implementing a proposed system layout with the minimum effect of energy consumption.

CFD Simulation Analysis of Pressure Drop in a Vertical Helical-Coil Heat Exchanger

2012 ◽  
Vol 562-564 ◽  
pp. 1095-1098
Author(s):  
Ning Jiang ◽  
Jia Li
Keyword(s):  
Heat Exchanger ◽  
Pressure Drop ◽  
Cfd Simulation ◽  
Simulation Analysis ◽  
Steel Tube ◽  
Stainless Steel Tube ◽  
Helical Coil ◽  
Two Phase ◽  
Coil Heat Exchanger ◽  
Coil Heat

The pressure drop in a helical-coil heat exchanger is studied. The helically coiled tube with a coil pitch of 1080 mm and coil diameter of 950 mm is fabricated by bending a stainless steel tube of 8m length and 15.6 mm inner diameter. The total height of the helix tube is 2.8 m. The concerned range of mass flow rate for two-phase flow is 25-100 kg/m2s. Computational fluid dynamics (CFD) simulation analysis of pressure drop in the vertical helical-coil heat exchanger is carried out.

Sign in / Sign up

Export Citation Format

Share Document