Experimental Investigation to Enhance the Heat Transfer in Heat Exchanger by Made Groove in Outer Surface of the Inner Tube

2017 ◽  
Vol 5 (1) ◽  
pp. 1-15
Author(s):  
Zena K. Kadhim ◽  
Safaa Abed Mohammad
Keyword(s):  
Heat Transfer ◽  
Heat Exchanger ◽  
Flow Rate ◽  
Outer Surface ◽  
Hot Water ◽  
Outer Tube ◽  
Copper Tube ◽  
Working Fluid ◽  
Outer Diameter ◽  
Inner Diameter

This study deals with experimental work implementing to recover the benefit by changing the shape of the tube in heat exchanger (HE) and improving the heat transfer using water as the working fluid. The experimental tests were carried out in build and design a complete test system for counter flow heat exchanger. The tested system consisting of a copper tube with (1m) length (17.05) mm inner diameter (19.05) mm outer diameter, fixed concentric within the outer tube was made of a material PVC. With an “inner diameter (ID) (43 mm) and outer diameter (OD) (50 mm)” isolated from the outside by using insulating material to reduce heat loss. The modify tube was manufacture containing transverse grooves with the depth equivalent to the half thickness of the copper tube. The distance between the grooves on the outer surface of the copper tube is take as a ratio between (0.5, 1) from the outer tube diameter. The laboratory experiment use the hot water at a flow rate ranging between (1-5) LPM, passes in the inner copper tube. As well as the cooling water with the mass flow rate ranging between (3-7) LPM. Three temperatures were the hot fluid are the adoption of (40, 50 and 60) oC and (25) oC the cold fluid. The experiment result showed that the improvement for temperature difference ranging from (14.94 % to 43.2 %) for both corrugated tubes with respect to smooth tube.

scholarly journals Thermal Characteristics Analysis on Multi- Heat Pipe Induced Heat Exchanger

2019 ◽  
Vol 9 (2S2) ◽  
pp. 143-147 ◽  
Keyword(s):  
Heat Transfer ◽  
Heat Exchanger ◽  
Heat Pipe ◽  
Mass Flow Rate ◽  
Mass Flow ◽  
Flow Rate ◽  
Cold Water ◽  
Hot Water ◽  
Working Fluid ◽  
Physical Parameters

In this investigation of multi heat pipe induced in heat exchanger shows the developments in heat transfer is to improve the efficiency of heat exchangers. Water is used as a heat transfer fluid and acetone is used as a working fluid. Rotameter is set to measure the flow rate of cold water and hot water. To maintain the parameter as experimental setup. Then set the mass flow rate of hot water as 40 LPH, 60LPH, 80 LPH, 100LPH, 120 LPH and mass flow rate of cold water as 20 LPH, 30 LPH, 40 LPH, 50 LPH, and 60 LPH. Then 40 C, 45 ºC, 50 ºC, 55 C, 60 ºC are the temperatures of hot water at inlet are maintained. To find some various physical parameters of Qc , hc , Re ,, Pr , Rth. The maximum effectiveness of the investigation obtained from condition of Thi 60 C, Tci 32 C and 100 LPH mhi, 60 LPH mci the maximum effectiveness attained as 57.25. Then the mhi as 100 LPH, mci as 60 LPH and Thi at 40 C as 37.6%. It shows the effectiveness get increased about 34.3 to the maximum conditions.

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.

scholarly journals Enhancement of Thermal Efficiency of Heat Exchanger using Titanium – Oxide nanofluid

2019 ◽  
Vol 8 (9) ◽  
pp. 871-875
Keyword(s):  
Heat Transfer ◽  
Heat Exchanger ◽  
Flow Rate ◽  
Removal Rate ◽  
Heat Removal ◽  
Working Fluid ◽  
Viscous Property ◽  
Volume Percentage ◽  
Conducting Property ◽  
Thermal Conducting

Improvement of heat removal rate in heat exchanger using passive techniques is considered to be one of the most challenging task for engineers and scientist. In this study efficiency of the heat exchangers has been studied with TiO2 / water based nanofluid. The thermal properties, physical properties and heat removal efficiency of heat exchanger with nano-fluid as working fluid was investigated. Nanoparticle concentration of about 0.1 and 0.3 vol% was used. It was detected that the thermal conducting property and viscous property of the nanofluid increased proportionally with volume percentage. With the increased heat, the thermal conducting property increased while the viscous property of the nanofluid decreased. The heat removal rate on both shell outlet and tube outlet was estimated for different mass flow rate. The experiment results showed that with increased volume percentage and flow rate, the heat transfer performance improved. A maximum enhancement of 34% was observed at 0.3 vol% and 6l/min. Though there is increase in heat transfer rate the pressure dropped and pumping requirement increase with volume concentration and flow rate.

scholarly journals A Numerical Study for a Double Twisted Tube Heat Exchanger

2021 ◽  
Vol 39 (5) ◽  
pp. 1583-1589
Author(s):  
Ali K. Abdul Razzaq ◽  
Khudheyer S. Mushatet
Keyword(s):  
Heat Transfer ◽  
Heat Exchanger ◽  
Numerical Study ◽  
Hot Water ◽  
Flow Mode ◽  
Outer Diameter ◽  
Outlet Temperature ◽  
Ansys Fluent ◽  
Tube Heat Exchanger ◽  
Twisted Tube

The thermal and fluid physiognomies of a double twisted tube heat exchanger was examined numerically. Twisted engineering is a wide-use method to improve heat transfer in heat exchangers. A counter-flow mode utilizing hot water in the inner tube and cold air in the outer tube was considered. This study aims to progress the thermal performance of the double tube heat exchanger by using twisted tubes instead of plane tubes. The heat exchanger was (1m) length, outer diameter (0.05m) and inner diameter (0.025m), both with a thickness (0.004m). It was tested for different values of twist ratios (Tr= 5, 10, and 15 respectively) and Reynolds numbers (Re=5000 to 30000). The Navier - Stockes and energy equations besides the turbulence model in demand for modelling this physical problem. ANSYS Fluent code was used for the numerical simulation. The results showed that the twisted tube heat exchanger showed increasing heat transfer compared with a plain tube heat exchanger. It was found that the cold outlet temperature, pressure drop and effectiveness are increased as the twist ratio increases.

scholarly journals Design and Analysis of double- stacked Heat Exchanger for Brewery Application

2020 ◽  
Vol 9 (1) ◽  
pp. 1793-1798
Keyword(s):  
Heat Transfer ◽  
Heat Exchanger ◽  
Pressure Drop ◽  
Heat Transfer Rate ◽  
Flow Rate ◽  
Transfer Rate ◽  
Working Fluid ◽  
Support Weight ◽  
Tube Heat Exchanger ◽  
Shell And Tube

A heat exchanger is a device intensively used for enhancing the transfer of heat energy between two or more working fluids at different temperature, which are in thermal contact. The optimal design and efficient operation of heat exchanger and heat transfer network are of a great significance in any of the process industry. The heat transfer efficiency depends on both design of heat exchanger and property of working fluid. From various types of heat exchanger, the double stacked shell and tube heat exchanger with straight tube and single pass is to be under study. Here the redesign of heat exchanger takes place with the key objectives of optimizing the pressure drop, optimizing the heat transfer rate and reducing the saddle support weight used for cooling purpose in brewery application. The design calculations are carried out using the Kerns and Bell Delwar method and other important parameters dealing with material selection and geometries are also taken into consideration. FEA analysis for optimizing the saddle support weight is carried out using Dassault systeme’s Solidworks while the CFD analysis for optimizing pressure drop and heat transfer rate is carried out using Dassault systeme’s Solidworks analysis software and the design and working of Shell and tube heat exchanger is determined in terms of variables such as pressure ,temperature ,mass flow rate ,flow rate ,energy input output that are of particular interest in Shell and tube heat exchanger analysis.

scholarly journals Effect of uniform and variable fin height on charging and discharging of phase change material in a horizontal cylindrical thermal storage

2019 ◽  
Vol 23 (3 Part B) ◽  
pp. 1981-1988 ◽  
Author(s):  
Ramalingam Senthil
Keyword(s):  
Heat Transfer ◽  
Phase Change ◽  
Phase Change Material ◽  
Flow Rate ◽  
Cold Water ◽  
Copper Tube ◽  
Heat Transfer Fluid ◽  
Outer Diameter ◽  
The One ◽  
Change Material

The effect of fin profile on melting of phase change material (PCM) is presented. The test section contains an acrylic tube of 50 mm outer diameter and a copper tube of 16 mm outer diameter and a length of 1000 mm each. Both tubes are kept coaxially. The heat transfer fluid (HTF) flows through the copper tube. The PCM is paraffin wax and filled in the annular region. The considered fin profiles are the uniform and variable fin heights of circular, triangular and elliptical profiles. Fins are fixed on the HTF tube and protruded into the PCM. The total fin surface area is maintained same among the fin profiles and the fin arrangements. The one-third of the storage is provided with increasing fin height of 2- 3 mm to melt the settled solid PCM. The hot and cold water is used to charge and discharge the PCM, respectively. Experiments are performed by the hot and cold-water inlet temperatures of 70 ?C and 28 ?C at a flow rate of 0.5 kg per minute. A faster and effective heat transfer from HTF to PCM and vice-versa is investigated. The variable elliptical fins showed faster charging and discharging by 25% and 20%, respectively, than the variable circular fins. The variable elliptical fins showed faster charging and discharging by 11.8% and 11% than the variable triangular fins. The charging and discharging efficiency of 80% and 74% are observed for the elliptical fin profiles.

Experimental Study on Heat Transfer and Fluid Flow in Vertical Rifled

2012 ◽  
Vol 505 ◽  
pp. 524-533 ◽  
Author(s):  
Abdulati Muftah Mohamed Ibrahim ◽  
Bashir Rahuma Elhub ◽  
H. Abas A. Wahab
Keyword(s):  
Heat Transfer ◽  
Experimental Study ◽  
Fluid Flow ◽  
Pressure Drop ◽  
Flow Rate ◽  
Smooth Tube ◽  
Enhancement Effect ◽  
Outer Diameter ◽  
Flow Monitoring ◽  
Inner Diameter

In this paper, heat transfer and fluid flow monitoring experiments for pressure drop and efficiency were performed to investigate the fluid flow characteristics of rifled tubes in comparison with a smooth tube. The rifled tube has an outer diameter of 25mm, maximum inner diameter of 18.8 mm; minimum inner diameter of 17.50mm, rib height of 0.6835, rib width of 9.25, helix angles 60 o and the number of starts is four. The smooth tube has an outer diameter of 26.7mm and an inner diameter of 18.88 mm, with a wall thickness of 3.91mm. The experiments were conducted on a vertical orientation of the steel tubes (rifled and smooth) under varying flow rate of 15, 30, 40, 50, 60 and 70. The fluid used is 131.64 litres of water and the initial temperature is 25oC. The fluid is raised to an average temperature of 33oC during the experimental study. During the experiment, it was found that at 360 mins for the smooth tube, an increase in flow rate does not affect the time for the fluid (water) to attain a temperature of 33oC. For the rifled tube, as the flow rate increases, the time for the fluid (water) to attain a temperature of 33oC also increases. This is as a result of the effect of ribbing the tube. The time taken to attain the optimum temperature of 33oC is shorter using the rifled tube than the smooth tube. The rifled tube has heat transfer efficiency higher than the smooth tube. The pressure drop and the energy consumed by using the rifled tube were also found to be less than that of the smooth tube. The pressure drop increase factor was found to be 0.85 in the spirally rifled tube as compared to the smooth tube at the different flow rates. The enhancement effect of ribbing the tube is apparent.

scholarly journals FEA Analysis of Double Tube Heat Exchanger on Variable Baffle Pitch for Optimizing Thermal Efficiency

2020 ◽  
Vol 6 (6) ◽  
pp. 15-28
Author(s):  
Anil Kumar ◽  
Rashmi Dwivedi ◽  
Sanjay Chhalotre
Keyword(s):  
Heat Transfer ◽  
Heat Exchanger ◽  
Mass Flow Rate ◽  
Mass Flow ◽  
Flow Rate ◽  
Hot Water ◽  
Maximum Temperature ◽  
Outer Side ◽  
Inlet Temperature ◽  
Cold Fluid

The main objective of this work is to compare different configurations of helical baffles in the cold fluid side of a double tube heat exchanger. For this analysis double pipe heat exchangers are divided into three different domains such as two fluid domains hot fluid in the inner tube and cold fluid in the outer pipe and a solid domain as helical baffles on inner tube of hot fluid. The hot water flows inside the heat exchanger tube, while the cold fluid flows in the outer side in the direction of counter flow. Mass flow rate cold fluid was varied from 0.1 kg/s to 0.3 kg/s while the flow rate in the inner tube i.e. hot water was kept constant at 0.1 kg/s. the inlet temperature of hot fluid taken as 40oC while Cold fluid inlet temperature taken as 15oC. The fluent software is used to calculate the fluid flow and heat transfer in the computational domains. The governing equations are iteratively solved by the finite volume formulation with the SIMPLE algorithm. Results show that that the maximum temperature drop of 10.9 oC for hot fluid and the maximum temperature rise of 11.9 oC for cold fluid are observed at 0.3 kg/sec mass flow rate for double pipe heat exchanger with double helical baffles. It has been also observed that the heat transfer coefficient increasing with the increasing in the mass flow rate of cold fluid. The overall heat transfer coefficients differ significantly by 20.4 % at same mass flow rate, because the considerable difference between heat transfer surface area on the inner and outer side of the tube resulting in a prominent thermal enhancement of the cold fluid.

scholarly journals Experimentation on Augmenting Heat Transfer Characteristics of (Ethylene Glycol + Water) Mixture in A Combined (Pipe in Pipe and Shell & Tube) Heat Exchanger

2019 ◽  
Vol 8 (3) ◽  
pp. 4442-4449
Keyword(s):  
Heat Transfer ◽  
Heat Exchanger ◽  
Mass Flow Rate ◽  
Mass Flow ◽  
Flow Rate ◽  
Heat Exchangers ◽  
Working Fluid ◽  
Counter Flow ◽  
Tube Heat Exchanger ◽  
Overall Heat Transfer Coefficient

In this research work, the design of pipe in pipe, shelland-tube and combined heat exchanger (previously mentioned types were combined to consider as one unit) has been made. These three heat exchangers have been utilized for two kinds of flows i.e., parallel as well counter flow types individually. The design of combined heat exchanger takes been proposed with the idea of increasing the heat transfer area and to understand the behavior of various parameters involved by comparing with the individual heat exchangers. 75:25 aqueous Ethylene Glycols, have been used as the working fluid in all three heat exchangers of counter as well parallel flow conditions. Total quantity of working fluid is 12 liters, in which 6liters of fluid is used as cold fluid and the other half is used as hot fluid. As a result, overall heat transfer coefficient (U) has been increased with increase of mass flow rate. Highest overall heat transfer coefficient value observed as 1943w/m2 -k at highest mass flow rate (within the considerations of this work) of 0.145 kg/s. The highest decrement in LMTD recorded for 0.0425 to 0.145 increase of mass flow rate is 49.32% in shell-and-tube heat exchanger of parallel flow arrangement. The highest effectiveness is observed for pipe in pipe counter flow heat exchanger case, which is 0.39 at a mass flow rate of 0.145kg/s.

Simulation and Analysis of the Supercritical ORC Heat Exchanger

2018 ◽  
Author(s):  
Yung-Ming Li ◽  
Chi-Chuan Wang
Keyword(s):  
Heat Transfer ◽  
Heat Exchanger ◽  
Critical Point ◽  
Mass Flow Rate ◽  
Mass Flow ◽  
Flow Rate ◽  
Transfer Rate ◽  
Working Fluid ◽  
Total Heat Transfer ◽  
Working Pressure

The traditional organic Rankine cycle (ORC) is operated below critical point. However, the specific heat of the working fluid undergoes tremendous change near the critical point. This can improve the thermal performance of the system due to the enhancement of heat transfer coefficient within the heat exchanger. However, the strong temperature dependence of thermo-physical properties of the working fluid especially at near the critical point requires much more efforts in designing a heat exchanger. Hence, more elaborate calculation involving stepwise integration is needed as far as accuracy is concerned. Therefore the heat exchanger is divided into several segments. The outlet temperatures of the first segment serve as the input parameters for the second segment, and the process is carried out further on. The fluid properties are calculated with the actual bulk temperature of each segment. With increasing number of segments, better resolution of temperature distribution of both heat source and working fluid within the heat exchanger is achieved. In the present study, a plate heat exchanger was numerically examined by using R-245fa as a working fluid at a supercritical condition. The effects of the working pressure and mass flow rate were examined in detail. For all cases in this study, the maximum of the total heat transfer rate was achieved by a working pressure of 3700 kPa, especially close to critical pressure. It is found that at a working pressure of 4000 kPa and mass flow rate ranging from 1 kg/s to 1.75 kg/s, the total heat transfer rate was independent of the mass flow rate.

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