Investigation of Ethylene Glycol Heat Transfer Coefficient Trough Double Pipe and Coil Heat Exchanger

2021 ◽  
Vol 874 ◽  
pp. 165-170
Author(s):  
Sri Wuryanti ◽  
Tina Mulya Gantina ◽  
Indriyani
Keyword(s):  
Heat Transfer ◽  
Heat Transfer Coefficient ◽  
Ethylene Glycol ◽  
Transfer Coefficient ◽  
Heat Transfer Rate ◽  
Transfer Rate ◽  
Test System ◽  
Double Pipe ◽  
The Heat Transfer Coefficient ◽  
Outer Pipe

The research objective is to assemble a convection test system which acts as a heat exchanger (HE) and test its applicability using ethylene glycol. A Double Pipe (DP)-type HE consists of an inner pipe surrounded by an outer pipe (annulus) whereas a Coil-type HE composed of a coil surrounded by an outer pipe. Water flows through the outer pipe in both types of HE, while ethylene glycol flows through the inner piper or coil. HE in combination with other components (such as) forms a convection test system. The applicability of the system was tested to determine the heat transfer coefficient of ethylene glycol in a DP-type and Coil-type HEs. After that, the heat transfer rate was calculated and compared. The results show that the heat transfer coefficient in the DP-type HE is the lowest at 12.2 W/m2 oC and the highest at 26.8 W/m2 oC; and the corresponding heat transfer rate is the lowest at 8.3 W and the highest is 56.3 W. In comparison, for Coil-type HE, the lowest heat transfer coefficient is 38.9 W/m2 oC and the highest is 66.2 W/m2 oC which correspond to the heat transfer rate 19.9 W at the lowest and 225 W at the highest.

scholarly journals Enhancement of Temperature Distribution and Heat Transfer Coefficient of Ribbed Tube by Simulation

2021 ◽  
Vol 7 (1) ◽  
pp. 21-28
Author(s):  
Rahul Kunar ◽  
Dr Sukul Lomash
Keyword(s):  
Heat Transfer ◽  
Heat Transfer Coefficient ◽  
Temperature Distribution ◽  
Transfer Coefficient ◽  
Heat Transfer Rate ◽  
Transfer Rate ◽  
Flow Analysis ◽  
Total Heat ◽  
Total Heat Transfer ◽  
The Heat Transfer Coefficient

The heat transfer from surface may in general be enhanced by increasing the heat transfer coefficient between a surface and its surrounding or by increasing heat transfer area of the surface or by both. The main objective of the study and calculate the total heat transfer coefficient. Improve the heat transfer rate by using ANSYS CFD. During the CFD calculations of the flow in internally ribbed tubes. And calculated the temperature distribution and pressure inside the tube by using ansys. The model was created using CatiaV5 and meshed with Ansys, and the flow analysis is done with Ansys 19.2. The results showing that the heat transfer is increased. The enthalpy and temperature increase with flow is advancing when compare with normal boiler tube. In this study the total heat transfer rate of the pipe increase with the increase the rib height. Total heat transfer rate increase up to 7.7kw. The study show that the improvement in furnace heat transfer can be achieved by changing the internal rib design.

Heat Transfer Studies in Coiled Agitated Vessel with Varying Heat Input

2011 ◽  
Vol 7 (4) ◽  
Author(s):  
V T Perarasu ◽  
M Arivazhagan ◽  
P Sivashanmugam
Keyword(s):  
Heat Transfer ◽  
Heat Transfer Coefficient ◽  
Transfer Coefficient ◽  
Heat Transfer Rate ◽  
Heat Input ◽  
Transfer Rate ◽  
Empirical Correlations ◽  
Agitated Vessel ◽  
Experimental Values ◽  
The Heat Transfer Coefficient

Heat transfer studies in a coiled agitated vessel with varying heat input is presented using two agitators namely propeller and disk turbine. Heat transfer rate increases with agitator speed for both the agitators for a given heat input. The heat transfer coefficient also increases with heat input for a given agitator speed for turbine agitator for all the heat inputs, whereas for propeller it is increasing up to a certain value and then decreases. The heat transfer coefficient (heat transfer rate) for turbine agitator is higher than that for propeller for all heat inputs. Empirical correlations separately were formed for each agitator and found to fit the experimental values within range of ±15% for both the agitators.

Heat Transfer Enhancement in a Horizontal Channel by the Addition of Curved Baffles

2006 ◽  
Author(s):  
J. L. Luviano ◽  
A. Hernandez ◽  
C. Rubio ◽  
D. Banerjee
Keyword(s):  
Heat Transfer ◽  
Heat Transfer Coefficient ◽  
Transfer Coefficient ◽  
Transfer Rate ◽  
Fluid Motion ◽  
Horizontal Channel ◽  
Parallel Plates ◽  
Energy Transfer Rate ◽  
Transfer Enhancement ◽  
The Heat Transfer Coefficient

This paper presents the heat transfer and fluid dynamics analysis of a horizontal channel formed by parallel plates with periodic insertions of heated blocks, having curved deflectors to direct the flow. The heat transfer coefficient investigated is compared with that of the horizontal channel without deflectors. The aim of the deflectors is to lead the fluid to the space between the heated blocks increasing the dynamics in this area. This zone will normally, without deflectors, become a stagnant fluid zone in which low energy transfer rate occurs. The results show that the heat transfer coefficient is larger as compared to that of the case without deflectors. The increment in the heat transfer coefficient is due primarily to the fluid motion stirred in the area between the heated block due to the deflectors. However, it must be pointed out. This implementation also increases the pressure drop in the channel.

Numerical Simulation about Heat Transfer Coefficient for the Double Pipe Heat Exchangers

2011 ◽  
Vol 71-78 ◽  
pp. 2577-2580 ◽  
Author(s):  
Hui Fan Zheng ◽  
Jing Bai ◽  
Jing Wei ◽  
Lan Yu Huang
Keyword(s):  
Heat Transfer ◽  
Heat Transfer Coefficient ◽  
Transfer Coefficient ◽  
Temperature Difference ◽  
Heat Exchangers ◽  
Total Heat Transfer ◽  
Double Pipe ◽  
Heat Exchanges ◽  
The Heat Transfer Coefficient ◽  
Pipe Heat

Based on the EES software, a heat transfer coefficient calculation program about double pipe heat exchanges is established. Some experimental data are compared to the simulation data for proving that the program can predict the heat transfer coefficient of the double pipe heat exchangers, and then the change of heat transfer coefficient is calculated and analyzed with relevant parameters. The results show that the heat transfer coefficient of heat exchanger are increasing with the flow of the shell side, the tube side and the logarithmic mean temperature difference, and when the temperature difference equals to 12°C, the total heat transfer coefficient can up to 2400W/m2.K or so.

CFD Investigation of Hydrodynamic and Heat Transfer Phenomena around Trilobe Particles in Hydrocracking Reactor

2012 ◽  
Vol 10 (1) ◽  
Author(s):  
Mohammad Reza Bandari ◽  
Yaghoub Behjat ◽  
Shahrokh Shahhosseini
Keyword(s):  
Heat Transfer ◽  
Heat Transfer Coefficient ◽  
Liquid Film ◽  
Transfer Coefficient ◽  
Heat Transfer Rate ◽  
Transfer Rate ◽  
Volume Fraction ◽  
Film Formation ◽  
Liquid Volume ◽  
Liquid Volume Fraction

In this work, computational fluid dynamics (CFD) has been employed to compute local convection heat transfer coefficient (h) that is the key parameter in calculation of heat transfer rate between the particle and fluids in packed bed reactors. In addition, the relation between Reynolds number and Nusselt number for spherical and trilobe catalyst particles have been investigated. Moreover, the parameters of Ranz-Marshall (R-M) correlation have been estimated in order to use it for trilobe catalyst particle. The heat transfer coefficients of the spherical and trilobe particles were compared and the effect of particle shape and configuration on heat transfer rate has been investigated. Eulerian-Eulerian approach was employed in order to investigate gas-liquid hydrodynamic especially liquid film formation around trilobe particles. The effects of liquid film around a trilobe particle and liquid volume fraction on heat transfer coefficient have also been studied. The CFD simulation results indicate that increasing inlet liquid volume fraction raises the liquid film thickness around the particles leading to reduction of heat transfer coefficient. In addition, the results revealed that flow field and temperature profiles around the particles became more complicated as a result of liquid film formation and gas-liquid interactions.

Experimental Study and High Speed Visualization of Flow Boiling Characteristics in Silicon Microgap Heat Sink

2012 ◽  
Author(s):  
Tamanna Alam ◽  
Poh Seng Lee ◽  
Christopher R. Yap ◽  
Liwen Jin
Keyword(s):  
Heat Transfer ◽  
Heat Flux ◽  
Heat Transfer Coefficient ◽  
Transfer Coefficient ◽  
Heat Transfer Rate ◽  
Heat Sink ◽  
Transfer Rate ◽  
High Speed ◽  
Flow Boiling ◽  
Gap Size

Flow boiling in microgap heat sink is very attractive for high-performance electronics cooling due to its high heat transfer rate and easy fabrication process. In absence of thermal interface material between the active electronic component and a microgap cold plate, significant reduction in interface thermal resistance and enhancement in heat transfer rate can be achieved. In earlier studies by these authors, encouraging results have been obtained using microgap heat sink as it can potentially mitigate flow instabilities, flow reversal and maintain uniform wall temperatures over the heated surface. So, more work should be carried out to advance the fundamental understanding of the two-phase flow heat transfer associated with microgap heat sink and the underlying mechanisms. In this study, local flow boiling phenomena in different microgap sizes have been investigated experimentally. Experiments are performed in silicon based microgap heat sink having microgap depth ranging from 80 μm to 500 μm, using deionized water with 10 °C subcooled inlet temperature. The effects of mass flux and heat flux on heat transfer coefficient and pressure drop characteristics are examined by using different mass fluxes ranging from 400 kg/m2s to 1000 kg/m2s and effective heat flux varying from 0 to 100 W/cm2. Apart from these experimental investigations, simultaneous high speed visualizations are conducted to observe and explore the mechanism of flow boiling in microgap. Confined slug and annular boiling are observed as the two main heat transfer mechanisms in microgap. Moreover, experimental results show that flow boiling heat transfer coefficients are dependent on gap size, and the lower the gap size, higher the heat transfer coefficient.

Condensation of Freon-114 in the Presence of a Strong Nonuniform, Alternating Electric Field

1970 ◽  
Vol 92 (4) ◽  
pp. 616-620 ◽  
Author(s):  
R. E. Holmes ◽  
A. J. Chapman
Keyword(s):  
Heat Transfer ◽  
Experimental Data ◽  
Heat Transfer Coefficient ◽  
Electric Field ◽  
Transfer Coefficient ◽  
Flat Plate ◽  
Transfer Rate ◽  
Reasonable Agreement ◽  
Alternating Electric Field ◽  
The Heat Transfer Coefficient

The condensation of Freon-114 in the presence of a nonuniform, alternating, 60-cycle, electric field was examined experimentally. The condensing surface was a grounded, cooled flat plate, and the electric field was produced by applying a voltage to a second plate placed above the first. Voltages up to 60 kv were imposed, and nonuniformities in the field were created by varying the angle between the plates. Analytical predictions were made of the expected heat-transfer rate, and reasonable agreement with the experimental data was obtained for voltages less than 40 kv. Above 40 kv the results were unpredictable, but increases in the heat-transfer coefficient as high as ten times that for no field were obtained.

scholarly journals Heat transfer characteristics of molten salt flowing in steam generator

2021 ◽  
pp. 225-225
Author(s):  
Shiquan He ◽  
Linhao Wei ◽  
Jianfeng Lu ◽  
Weilong Wang
Keyword(s):  
Heat Transfer ◽  
Heat Transfer Coefficient ◽  
Transfer Coefficient ◽  
Molten Salt ◽  
Steam Generator ◽  
Inlet Temperature ◽  
Heat Transfer Characteristics ◽  
Shell And Tube ◽  
Double Pipe ◽  
The Heat Transfer Coefficient

The paper respectively investigated the heat transfer characteristics of molten salt flowed in shell-and-tube and double-pipe steam generator. The shell-and-tube steam generator had seven tubes and molten salt flowed outside the tubes, while the double-pipe steam generator had two concentric tubes and molten salt flowed in the annular duct formed by two tubes. Inlet temperature of molten salt ranged from 270?C to 420?C. The experimental results showed the effect of temperature on heat transfer coefficient was more significant in the double-pipe steam generator compared to the shell-and-tube steam generator. The heat transfer coefficient firstly increased and then decreased as the increase of temperature. Further numerical study was conducted and the results showed, in the shell-and-tube steam generator, the flow is disturbed by the tube bundle and the boundary layer near the inner wall is deformed, so the temperature of molten salt cannot obviously affect the heat transfer. In the double-pipe steam generator, an opposite flow was generated in the near cooled wall region by the buoyancy force. When the inlet temperature was below 315?C, the velocity of the opposite flow was quite low. In this stage, the heat transfer coefficient increased with the increase of temperature. When the inlet temperature continues to rise to 390?C, the opposite flow was enhanced and a stable layer with low velocity formed between the mainstream and the inner cooled wall, resulting increase of heat transfer resistance and impairment of heat transfer coefficient.

Turbulent Multi-Jet Air Impingement for Applications in Commercial Cooking

2018 ◽  
Author(s):  
Shantanu S. Shevade ◽  
Muhammad M. Rahman ◽  
Rasim O. Guldiken
Keyword(s):  
Heat Transfer ◽  
Heat Transfer Coefficient ◽  
Surface Temperature ◽  
Transfer Coefficient ◽  
Convective Heat Transfer ◽  
Heat Transfer Rate ◽  
Transfer Rate ◽  
Convective Heat Transfer Coefficient ◽  
Diameter Ratio ◽  
Impingement Surface

Convective heat transfer coefficient and its interdependency with various key parameters is analyzed for turbulent multi-jet impingement. Air is used as the working fluid impinging on the flat surface via a three-nozzle arrangement. A thorough investigation of velocity and temperature distribution is performed by varying Nozzle Velocity, Height over Diameter ratio (H/D) and Spacing over Diameter ratio (S/D). Convective heat transfer coefficient, average impingement surface temperature, and heat transfer rate are calculated over the impingement surface. It was found that higher S/D ratios result in higher local heat transfer coefficient values near stagnation point. However, increased spacing between the neighboring jets results in less coverage of the impingement surface reducing the average heat transfer. Lower H/D ratios result in higher heat transfer coefficient peaks. The peaks for all three nozzles are more uniform for H/D ratios between 6 and 8. For a fixed nozzle velocity, heat transfer coefficient values are directly proportional to nozzle diameter. For a fixed H/D and S/D ratio, heat transfer rate and average impingement surface temperature increase as the nozzle velocity increases until it reaches a limiting value. Further increase in nozzle velocity causes drop in heat transfer rate due to ingress of large amounts of cold ambient air in the cooking space.

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