scholarly journals Nanofluid-Enhancing Shell and Tube Heat Exchanger Effectiveness with Modified Baffle Architecture

2021 ◽  
Author(s):  
I Made Arsana ◽  
Ruri Agung Wahyuono

As shell and tube heat exchanger is widely employed in various field of industries, heat exchanger design remains a constant optimization challenge to improve its performance. The heat exchanger design includes not only the architectural geometry of either the shell and tube configuration or the additional baffles but also the working fluid. The baffle design including the baffle angle and the baffle distance has been understood as key parameter controlling the overall heat exchanger effectiveness. In addition, a room of improvement is open by substituting the conventional working fluid with the nanomaterials-enriched nanofluid. The nanomaterials, e.g. Al2O3, SiO2, TiO2, increases the thermal conductivity of the working fluids, and hence, the more efficient heat transfer process can be achieved. This chapter provide an insight on the performance improvement of shell and tube heat exchanger by modifying the baffle design and utilizing nanofluids.

Author(s):  
S. V. Sridhar ◽  
R. Karuppasamy ◽  
G. D. Sivakumar

Abstract In this investigation, the performance of the shell and tube heat exchanger operated with tin nanoparticles-water (SnO2-W) and silver nanoparticles-water (Ag-W) nanofluids was experimentally analyzed. SnO2-W and Ag-W nanofluids were prepared without any surface medication of nanoparticles. The effects of volume concentrations of nanoparticles on thermal conductivity, viscosity, heat transfer coefficient, fiction factor, Nusselt number, and pressure drop were analyzed. The results showed that thermal conductivity of nanofluids increased by 29% and 39% while adding 0.1 wt% of SnO2 and Ag nanoparticles, respectively, due to the unique intrinsic property of the nanoparticles. Further, the convective heat transfer coefficient was enhanced because of improvement of thermal conductivity of the two phase mixture and friction factor increased due to the increases of viscosity and density of nanofluids. Moreover, Ag nanofluid showed superior pressure drop compared to SnO2 nanofluid owing to the improvement of thermophysical properties of nanofluid.


Author(s):  
Paritosh Singh

Abstract: Research in convective heat transfer using suspensions of nanometer sized solid particles in a base fluid started only over the past decade. Recent investigations on nanofluids, as such suspensions are often called, indicate that the suspended nanoparticles markedly change the transport properties and heat transfer characteristics of the suspension. The very first part of the research work summarizes about the various thermo physical properties of Al2O3 Nanofluid. In evacuated tube solar water heating system nanofluids are used as primary fluid and DM water as secondary fluid in Shell and Tube Heat Exchanger. The experimental analysis of Shell and Tube heat exchanger integrated with Evacuated tube solar collector have been carried out with two types of primary fluids. Research study of shell and tube heat exchanger is focused on heat transfer enhancement by usage of nano fluids. Conventional heat transfer fluids have inherently low thermal conductivity that greatly limits the heat exchange efficiency. The result of analysis shows that average relative variation in LMTD and overall heat transfer coefficient is 24.56% and 52.0% respectively. The payback period of system is reduced by 0.4 years due to saving is in replacement cost of Evacuated Tube Collector. Keywords: ETC; Nanofluid; LMTD; Thermal Conductivity; Overall heat transfer coefficient


Author(s):  
Syed Sameer ◽  
SB Prakash ◽  
G Narayana Swamy

Nanoparticles enhances the heat transfer between particles and the fluids due to their high specific surface area and adjustable properties, including thermal conductivity and surface wettability, by varying particle volume concentrations in the base fluid to suit different applications. This article is an experimental study on the effectiveness and overall heat transfer coefficient in STHE (shell and tube heat exchanger), comprising baffle cut 25% with a nanofluid at 0.05, 0.1, and 0.2 percentage concentrations of CuO nanoparticles in the DW (distilled water) base-fluid. The inclusion of 0.15% SDBS (Sodium dodecyl-benzene sulphonate) by a two-step method as a surfactant improves the stability of dispersed CuO nanoparticles. The CuO/DW nanofluid thermo-physical properties such as thermal conductivity (k), density (ρ), and dynamic viscosity (μ), have increased. However, the nanofluid's specific heat (Cp) reduces as the nanoparticles proportion rises in the DW base fluid. There is an enhancement of the overall heat transfer coefficient and effectiveness compared to water during parallel flow variation. The maximum heat exchanger effectiveness was 3.01%, 4.01%, and 5.94% higher than water at 0.6 lpm mass flow rate and temperature T = 80 °C for volume fractions of 0.05, 0.1, and 0.2 percentage of CuO/DW nanofluid respectively during parallel flow.


2020 ◽  
Author(s):  
sreejesh S R chandran ◽  
Debabrata Barik ◽  
ANSALAM RAJ T G ◽  
Reby ROY

Abstract Nanofluids are generally utilized in providing cooling, lubrication phenomenon, controlling the thermophysical properties of the working fluid. In this work, nanoparticles of Al2O3 are added to the base fluid which flows through the counter flow arrangement in a turbulent flow condition. The hot and cold fluids used are ethylbenzene and water respectively and have different velocities on both shell and tube side. This study emphasizes the analysis of flow properties, friction loss, and energy transfer in terms of heat using nanofluid in the heat exchanger. The heat transfer rate of present investigation with nanoparticle addition is 4.63% higher in comparision to Dittus Boelter correlation. Apart from this, the obtained friction factor is 0.0376 very much closer to Gnielinski and Blasius correlations. This investigation proved that appropriate nanoparticle additions and baffle inclinations have fabulous impact upon the performance of heat exchanger and its effectiveness.


2020 ◽  
Vol 9 (1) ◽  
pp. 1793-1798

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.


Author(s):  
S. Mohanty ◽  
R. Arora

In this investigation, a comprehensive approach is established in detail to analyse the effectiveness of the shell and tube heat exchanger (STE) with 50% baffle cuts (Bc) with varying number of baffles. CFD simulations were conducted on a single pass and single tube heat exchanger(HE) using water as working fluid. A counterflow technique is implemented for this simulation study. Based on different approaches made on design analysis for a heat exchanger, here, a mini shell and tube exchanger (STE) computational model is developed. Commercial CFD software package ANSYS-Fluent 14.0 was used for computational analysis and comparison with existing literature in the view of certain variables; in particular, baffle cut, baffle spacing, the outcome of shell and tube diameter on the pressure drop and heat transfer coefficient. However, the simulation results are more circumscribed with the applied turbulence models such as Spalart-Allmaras, k-ɛ standard and k-ɛ realizable. For determining the best among the turbulence models, the computational results are validated with the existing literature. The proposed study portrays an in-depth outlook and visualization of heat transfer coefficient and pressure drop along the length of the heat exchanger(HE). The modified design of the heat exchanger yields a maximum of 44% pressure drop reduction and an increment of 60.66% in heat transfer.


2017 ◽  
Vol 5 (2) ◽  
pp. 42-54
Author(s):  
Najim Abid Jassim ◽  
Kamel Abdul Hussin ◽  
Noor Yahya Abdul Abbass

In the present work the analysis of three different width ratio of twisted tape in a shell and tube heat exchanger done by ANSYS FLUINT14.0. Heat exchanger type shell and tube have been widely used in industrial application such as refrigeration and environment protection, electrical power generation and chemical engineering. This work deals with the theoretical investigation, which was to evaluate the benefit of changing the width of twisted tape in the heat exchanger and the improving the heat transfer by using water as the working fluid in the first case, then using Nano fluids as a heat transfer working fluid. From the use of the condition in table (1) the simulation shows results of enhancement in heat transfer rate ranging from (53.24% to 55.55%) at width ratio 0.71, (53.62% to 56.09%) at width ratio 0.854 and (52.44% to 57.17%) at width ratio 1, for plain tube with twisted tape with respect to plain tube without twisted tape by using water as cooling fluid. By using Nano- fluid (AL2O3) the enhancement in heat transfer is (69.14% to 60.44%) at width ratio 0.71, (58.36% to 61.51%) at width ratio 0.854 and (56.76% to 63.35%) at width ratio1, for plain tube with twisted tape with respect to plain tube without twisted tape.


Author(s):  
Shamkuwar S.C ◽  
◽  
Nitin Chopra ◽  
Mihir Kulkarni ◽  
Nikhil Ahire ◽  
...  

The main objective of the paper is to compare the performance of Shell and tube heat exchanger (STHE) and Plate heat exchanger (PHE) used in chillers. The paper deals with experimental investigation and comparison, which is based on actual testing of STHE and PHE. Both heat exchangers were designed and tested for a heat load of 6000 kcal/hr. In both types of heat exchangers, the primary working fluid used is Refrigerant R22 and secondary working fluid used is water. Theoretical analysis shows that PHE has a 9.67 % less heat transfer area than STHE. Experimental results show that overall heat transfer coefficient (OHTC) for PHE is higher than STHE by 30.96%. The paper also includes a comparison of the heat transfer rate (Q) of the two heat exchangers experimentally.


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