A New Approach to Numerical Simulation of Small Sized Plate Heat Exchangers With Chevron Plates

2006 ◽  
Vol 129 (3) ◽  
pp. 291-297 ◽  
Author(s):  
Sanjeev Jain ◽  
Aniruddha Joshi ◽  
P. K. Bansal

A numerical and experimental study of heat transfer and fluid flow in a single pass counter flow plate heat exchanger with chevron plates has been presented in this paper. CFD analysis of small sized plate heat exchanger was carried out by taking the complete geometry of the heat transfer surface and more realistic hydrodynamic and thermal boundary conditions. A cold channel with two chevron plates and two halves of hot channels on either side having flat periodic boundaries was selected as the computational domain. The numerical model was validated with data from experiments and empirical correlations from literature. Heat transfer and pressure drop data were obtained experimentally with water as the working fluid, in the Reynolds number range 400–1300 and the Prandtl number range 4.4–6.3.

Author(s):  
Kohei Koyama ◽  
Yuya Nakamura ◽  
Hirofumi Arima

This study investigates FC-72 (Perfluorohexane) flow boiling in a plate heat exchanger. A plate heat exchanger which has a transparent cover plate is manufactured to visualize boiling two-phase flow pattern of the working fluid FC-72 heated by hot water. Titanium is used for heat transfer plate, which has micro pin-fin structure on the heat transfer surface to enhance heat transfer. Experiment is conducted for parallel- and counter-flow arrangements to compare thermal and hydraulic performances. Flow boiling is photographed by a digital camera and instantaneous images are processed to classify flow pattern and to measure void fraction in the heat exchanger. Flow rates and temperatures of FC-72 and hot water at inlet and outlet of the heat exchanger are simultaneously measured to obtain overall heat transfer coefficient. Two-phase flow pattern of FC-72 flow boiling and void fraction along flow direction as well as thermal performance are discussed. Experimental results show that bubbly flow, slug flow, and churn flow are observed for the experimental range of this study. Extent of churn flow in the parallel-flow heat exchanger is larger than that of the counter-flow one due to generated bubbles at upstream region in working fluid channel. Void fraction of the parallel-flow plate heat exchanger increases rapidly compared with that of the counter-flow one due to location of onset of nucleate boiling. Overall heat transfer coefficients for the parallel-flow arrangement is larger than that of the counter-flow due to destruction of thermal boundary layer. The experimental results show that flow arrangement of a plate heat exchanger has the potential to improve its thermal performance.


2021 ◽  
Vol 3 (4) ◽  
Author(s):  
Sirine Chtourou ◽  
Hassene Djemel ◽  
Mohamed Kaffel ◽  
Mounir Baccar

AbstractThis study presents a numerical analysis of a laminar counter flow inside small channels plate heat exchanger fitted with Y and C shape obstacles. Using the Computational Fluid Dynamics CFD, an advanced and modern simulation technique, the influence of the geometrical parameters (such as geometry, rib pitch) on the flow characteristics, the thermal and the hydrodynamics performance of the PHE (plate heat exchanger) is investigated numerically. The main goal of this work is to increase the flow turbulence, enhance the heat transfer and the thermal efficiency by inserting new obstacles forms. The computational domain is a conjugate model which is developed by the Computer Aided Design CAD software Solidworks. The results, obtained with Ansys Fluent, show that the presence of the shaped ribs provides enhancement in heat transfer and fluid turbulence. The CFD analysis is validated with the previous study. The non-dimensional factors such as the Nusselt number Nu, the skin friction factor Cf and the thermo-hydraulic performance parameter THPP are predicted with a Reynolds number Re range of 200–800. The temperature and the velocity distribution are presented and analyzed. The Y ribs and the C ribs offer as maximum THPP values respectively about 1.44 and 2.6 times of a smooth duct.


Author(s):  
Marjan Goodarzi ◽  
Ahmad Amiri ◽  
Mohammad Shahab Goodarzi ◽  
Mohammad Reza Safaei ◽  
Arash Karimipour ◽  
...  

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.


Author(s):  
Wenjing Du ◽  
Fei Wang ◽  
Gongming Xin ◽  
Shihu Zhang ◽  
Lin Cheng

In conventional Plate Heat Exchangers (PHEs), a good heat transfer performance is usually obtained at the cost of much pumping power consumption. In order to address this dilemma, a novel Regular Hexagonal Plate Heat Exchanger (RHPHE) is proposed in this paper. Specially-shaped spherical ribs and quasi-spiral flow paths are designed on plates with the purpose of achieving a best trade-off between the heat transfer and fluid flow performance. Because of its regular hexagonal structure with 3 inlets and 3 outlets, three or at least two kinds of fluids with different temperatures can exchange heat in a single set of heat exchanger. It is an innovation that multiple fluids heat transfer in a PHE without the assistance of supplementary baffles. Numerical investigation is carried out on the RHPHE and water is the working fluid. The heat transfer and flow performance of the RHPHE in a series of working conditions are investigated. Results show that heat transfer coefficient per unit pressure drop of the RHPHE is much better than that of the widely accepted PHE with 60° chevron corrugations. Also studied is the influence of various combinations of inlet and outlet positions on heat transfer and fluid flow performance. For the thermodynamic analysis, the entropy generation caused by heat conduction under finite temperature difference and fluid friction is obtained numerically. The variation of the entropy generation number with respect to the Reynolds number is depicted, which provides reference for the future optimization design of the RHPHE.


Author(s):  
Adnan Sözen ◽  
Ataollah Khanları ◽  
Erdem Çiftçi

Plate heat exchangers having high efficiency and small size are one of the mostly used heat exchangers. They are used in many applications ranging from cooling to heating. Heat transfer improvement of plate heat exchangers can be performed using nanoparticle-including working fluids, i.e. nanofluids. Influences of kaolin-including nanofluid utilization as working fluid on heat transfer performance of the plate heat exchanger were experimentally investigated in this study. The prepared nanofluid included 2% (wt/wt) nanoparticle content and Triton X-100 surfactant was added to the prepared mixture at the rate of 0.2% of a final concentration to increase the solubility of nanoparticles. The experiments were performed in various working conditions with changes in mass flow rate and temperature. The obtained results showed that nanofluid usage as the working fluid enhanced the heat transfer rate in plate heat exchanger in comparison to the results acquired from the tests conducted by deionized water. The improvement rate in mean heat transfer coefficient was achieved as 9.3% when kaolin–deionized water nanofluid was used as the working fluid in plate heat exchanger.


2019 ◽  
Vol 8 (1) ◽  
pp. 27 ◽  
Author(s):  
Adnan Sözen ◽  
Ataollah Khanları ◽  
Erdem Çiftçi

Plate heat exchangers, a compact-type heat exchanger, are commonly used heat transfer devices because of their superior characteristics. Their thermal performances are strongly dependent to working fluid circulating inside the system. The influences of nanofluid utilization as the working fluid in a plate heat exchanger was experimentally and numerically analysed in this study. In order to show off the improvement rate in heat transfer, the experiments were performed by using deionized water and TiO2-deionized water nanofluid. The nanofluid was prepared at the rate of 1.5 % as weighted. A surface-active agent, Triton X-100, was also doped into the mixture at the rate of 0.2% of a final concentration to prevent the sedimentation and flocculation of the nanoparticles inside the solution. The experiments were performed in different temperatures as 40°C, 45°C, 50°C and varying cold fluid mass flow rates as 3,4, 5, 6 and 7 lpm.  In addition, using the experimental data, a numerical simulation was realized by ANSYS Fluent software.  The both results indicate that heat transfer rate in plate heat exchanger can be improved using nanofluid as the working fluid in place of deionized water. The maximum improvement rate in heat transfer was obtained as 11 % in experimental study. It is also seen that experimental and numerical results are in good agreement.©2019. CBIORE-IJRED. All rights reservedArticle History: Received May 18th 2018; Received in revised form October 17th 2018; Accepted January 8th 2019; Available onlineHow to Cite This Article: Sözen, A., Khanlari, A., and Çiftçi, E. (2019) Experimental and Numerical Investigation of Nanofluid Usage in a Plate Heat Exchanger for Performance Improvement. Int. Journal of Renewable Energy Development, 8(1), 27-32.https://doi.org/10.14710/ijred.8.1.27-32


2013 ◽  
Vol 860-863 ◽  
pp. 696-699 ◽  
Author(s):  
Yu Han Zhao ◽  
Yi Fan Wu ◽  
Hai Jin Cheng ◽  
Guo Lei Zhu

In this paper the numerical simulation is performed by using the CFD soft FLUENT. A 3D geometric model is established and whose mesh is generated. The fields of the temperature, pressure and velocity in the computational domain are simulated. And the effect of the corrugation depth on the heat transfer and flow is analyzed.


Energies ◽  
2021 ◽  
Vol 14 (20) ◽  
pp. 6761
Author(s):  
Junhyeok Yong ◽  
Junggyun Ham ◽  
Ohkyung Kwon ◽  
Honghyun Cho

In this study, the heat exchange characteristics of water–LiBr solutions used as working fluid in a plate heat exchanger (PHE) were experimentally investigated at various concentrations. To analyze the heat transfer characteristics under LiBr/water conditions, a brazing type plate heat exchanger was installed, and the LiBr concentration on the high-temperature side was controlled at 56%, 58%, 60% and 60%. The results showed that the average heat transfer rate under water/water conditions was higher than that under LiBr/water conditions and the average heat transfer rate decreased as the LiBr concentration on the hot side increased. In addition, under both water/water and LiBr/water conditions, the average heat transfer rate and overall heat transfer coefficient increased as the mass flow rate of the working fluid on the hot side increased. When LiBr was used, the Reynolds number (Re) of LiBr on the hot side was more than nine times lower than that of water at the same mass flow rate owing to the influence of the increased viscosity. Based on the data obtained from the water/water and LiBr/water experiments, a correlation for predicting the Nusselt number (Nu) on the hot side in a wide range was developed.


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