Heat transfer and fluid flow in a single pass counter flow chevron corrugated-plates plate heat exchanger considering nanofluids (SiO2 and CuO) as homogeneous mixtures has been presented in this dissertation using the Commercial CFD software, ANSYS FLUENT. The required thermo physical properties of the nanofluid have been taken from literature and used in CFD Model. Individual optimum concentration of SiO2/water and CuO/water nanofluids yields maximum heat transfer improvement with regards to the temperature, pressure and velocity fields. The results of CFD analysis of CuO and SiO2 were compared with Common fluid Water in order to verify the accuracy of the homogeneous model. Analysis can be performed to predict the plate heat exchanger performance with reasonable accuracy. SiO2/water gives better heat transfer performance compared to CuO/water. CFD Analysis shows that corrugation pattern of the plate develops turbulence and vortices of fluid which results in high heat transfer rates

Nagaraj, M.R.

Rafeeq, Mohammed

International Journal of Innovative Technology and Research (IJITR)

      Mohammed Rafeeq * et al. (IJITR) INTERNATIONAL JOURNAL OF INNOVATIVE TECHNOLOGY AND RESEARCH Volume No.5, Issue No.4, June – July 2017, 7010-7015. 2320 –5547 @ 2013-2017 http://www.ijitr.com All rights Reserved. Page | 7010 CFD Investigation Of Plate Heat Exchanger Using Nanofluids MOHAMMED RAFEEQ M.Tech Student in Department of Mechanical Engineering, PDA College of Engineering Kalaburagi, Karnataka, India. M.R. NAGARAJ Associate Professor, Department of Mechanical Engineering, PDA College of Engineering Kalaburagi, Karnataka, India.Abstract: Heat transfer and fluid flow in a single pass counter flow chevron corrugated-plates plate heat exchanger considering nanofluids (SiO2 and CuO) as homogeneous mixtures has been presented in this dissertation using the Commercial CFD software, ANSYS FLUENT. The required thermo physical properties of the nanofluid have been taken from literature and used in CFD Model. Individual optimum concentration of SiO2/water and CuO/water nanofluids yields maximum heat transfer improvement with regards to the temperature, pressure and velocity fields. The results of CFD analysis of CuO and SiO2 were compared with Common fluid Water in order to verify the accuracy of the homogeneous model. Analysis can be performed to predict the plate heat exchanger performance with reasonable accuracy. SiO2/water gives better heat transfer performance compared to CuO/water. CFD Analysis shows that corrugation pattern of the plate develops turbulence and vortices of fluid which results in high heat transfer rates. Keywords: Plate Heat Exchanger; Nanofluids; SiO2; CuO; Heat Transfer; CFD Analysis; I. INTRODUCTION Plate heat exchangers (PHEs) were introduced meet the hygienic demands of the dairy industry and are still the most popular heat transfer devices widely used in many engineering applications because of their several advantages such as small size and weight, high thermal efficiency, suitability in hygienic applications, flexibility and ease of sanitation as well as their superior thermal performance compared to other types of compact heat exchangers. Innovative heat transfer fluids with suspended nanometer-sized solid particles are called ‘nanofluids’, Plate heat exchangers (PHEs) are not a new concept or technology. One of the first patents was issued in 1890 to Langem and Hundhanssen, a German company. In the past, this type of exchanger has been successfully used in industries such as dairy, process, paper/pulp, and heating, ventilating, and air conditioning (HVAC). The main purpose of this article is to direct potential re-searchers to the subject of PHE, because current industries lack fundamental information about them. These types of evaporators are being used in the heating, ventilating, air conditioning, and refrigeration (HVAC&R) industry on a regular basis, yet there is no guidance whatsoever. The objective here is to present the status of industrial practice and methods after considering years of fieldwork and “real world” data. Early usage of the PHE was in the dairy industry, but innovative designs and improvements in its mechanical integrity and sealing aspects allowed application into new areas. These developments included several unique plate designs and complicated stamping techniques. Plates with high and low chevron angles began to be used in mixed configurations, which eventually resulted in a single mixed chevron plate. With the advent of fast computers, one could precisely distribute different chevron patterns in order to optimize the surface area at minimum pumping power. Since plate exchangers use gaskets for sealing, the air conditioning and refrigeration industry did not readily adopt this technology due to concerns over leakage. However, the industry was aware of the extraordinary performance and compactness of PHEs. With the advent of the ozone-depletion issue in the mid-1980s, some companies started seriously considering the introduction of plate exchangers because their compact-ness would result in a low refrigerant charge. Obviously, a low charge meant lower environmental impact and lower inventory costs. The higher thermal efficiency of these exchangers allowed a system to operate at closer approach temperatures than did shell and tube exchangers, which would result in energy savings.of 1223K.   Figure 1: Gasketed plate and frame exchanger (courtesy Mueller). Pantzali et al. [1] investigated experimentally the efficacy of nanofluids as coolants in a commercial herringbone-type PHE.  Pantzali et al. [2] studied numerically and experimentally the effects of nanofluids on volumetric flow rate of nanofluid is lower than that of water causing lower pressure drop and resulting in less pumping power. Roetzel et al. [3] experimentally evaluated thermal       Mohammed Rafeeq * et al. (IJITR) INTERNATIONAL JOURNAL OF INNOVATIVE TECHNOLOGY AND RESEARCH Volume No.5, Issue No.4, June – July 2017, 7010-7015. 2320 –5547 @ 2013-2017 http://www.ijitr.com All rights Reserved. Page | 7011 parameters of plate type heat exchangers using a temperature oscillation technique, and a mathematical model was used to calculate heat transfer coefficient characterized by Number of Transfer Units and Peclet Number.   Figure 2: Plate Heat Exchanger II. GEOMETRY OF THE MODEL: The computer aided design (CAD) geometry for all models was modeled in SOLID WORKS and simulations were carried out in ANSYS FLUENT.  Figure 3:  Geometry of Plate Heat Exchanger Boundary conditions Different boundary conditions were applied for different zones. Since it is a tube-in-tube heat exchanger, there are two inlets and two outlets. The inlets were defined as velocity inlets and outlets were defined as pressure outlets. The inlet velocity of the cold fluid was kept constant i.e. 2.5m/s, whereas velocity of hot fluid was varied from 1m/s to 2m/s for different experiments. The outlet pressures were kept default i.e. atmospheric pressure. The hot fluid temperature at inlet was 400K and cold fluid inlet temperature was kept 293K. The other wall conditions were defined accordingly. The surrounding air temperature was kept 270C and convective heat transfer coefficient between outer wall and surrounding was 2500W/m2K. III. MESHING In free meshing, a relatively coarser mesh is generated. It contains both tetrahedral and hexahedral cells having triangular and quadrilateral faces at the boundaries. Later, a fine mesh is generated using edge sizing. In this, the edges and regions of high pressure and temperature gradients are finely meshed.  Figure 4: Mesh  Figure 5: Final Mesh with tetrahedron elements IV. RESULTS Temperature Distribution of Plate Heat Exchanger with Water    Figure 6: Temperature Contour with Water Pressure & Velocity Distribution of Plate Heat Exchanger with Cold Fluid  Figure 7: Pressure Distribution of the Fluids along the plate heat exchanger using Cold Fluids  Figure 8: Velocity Distribution of the Fluids along the plate heat exchanger using Cold Fluids  Figure 9: Temperature along the length of the plate heat exchanger using water as cold fluid       Mohammed Rafeeq * et al. (IJITR) INTERNATIONAL JOURNAL OF INNOVATIVE TECHNOLOGY AND RESEARCH Volume No.5, Issue No.4, June – July 2017, 7010-7015. 2320 –5547 @ 2013-2017 http://www.ijitr.com All rights Reserved. Page | 7012 The above figure represents The temperature Distribution on the Fluid in the plate heat exchanger from the plot we can say that x-axis represents the length in meters of the plate heat exchanger vertically and  the y-axis represents Temperature in Kelvin The Curves in the plots blue color curve indicates temperature distribution of hot fluid (water) and yellow color curve indicates temperature distribution of Cold Fluid (water) and  we can observe from the graph the hot fluid temperature is decreasing and cold fluid temperature is increasing Due to hybrid nature of cold fluid Case I: Results of plate heat Exchanger with SiO2 nanofluid A vortex crosses the pressure opening Boundary Condition: Environment Pressure 1; Inlet flow/outlet flow=0.144563   Boundary Condition: Environment Pressure 2; Inlet flow/outlet flow=0.0405056  Figure 10: Temperature Distribution on the plate heat exchanger using SiO2 nanofluid  Figure 11: Pressure along the length of plate with SiO2 nanofluid The figure 11 represents The static Pressure Distribution on the Fluid in the plate heat exchanger from the plot we can say that x-axis represents the length in meters of the plate heat exchanger vertically and the y-axis represents pressure in Pascal the decrease in the plot is because the velocity in the plate area is higher because of constantly converting area and volume  Figure 12:  Temperature along the length of the plate heat exchanger using SiO2 nanofluid The figure 12 represents The temperature Distribution on the Fluid in the plate heat exchanger from the plot we can say that x-axis represents the length in meters of the plate heat exchanger vertically and  the y-axis represents Temperature in Kelvin The Curves in the plots indicate Hot Fluid and Cold fluid i.e. in this case cold fluid is SiO2 we can observe from the graph the hot fluid temperature is decreasing and cold fluid temperature is increasing Due to hybrid nature of cold fluid i.e., nano fluid the higher thermal conductivity and due to the conduction heat transfer and non-linearity in the plates result in the above plot Case II: Results of plate heat Exchanger with CuO nanofluid  Fig 13: Temperature Distribution on the plate heat exchanger using CuO nanofluid  Figure 14:   Pressure along the length of plate with nanofluids CuO nanofluid The figure 14 represents The static Pressure Distribution on the Fluid in the plate heat exchanger from the plot we can say that x-axis represents the length in meters of the plate heat exchanger vertically and the y-axis represents pressure in Pascal the decrease in the plot is because the velocity in the plate area is higher because of constantly converting area and volume.  Figure 15:  Temperature along the length of the plate heat exchanger using CuO nanofluid The figure 15 represents The temperature Distribution on the Fluid in the plate heat exchanger from the plot we can say that x-axis represents the length in meters of the plate heat       Mohammed Rafeeq * et al. (IJITR) INTERNATIONAL JOURNAL OF INNOVATIVE TECHNOLOGY AND RESEARCH Volume No.5, Issue No.4, June – July 2017, 7010-7015. 2320 –5547 @ 2013-2017 http://www.ijitr.com All rights Reserved. Page | 7013 exchanger vertically and the y-axis represents Temperature in Kelvin The Curves in the plots indicate Hot Fluid and Cold fluid i.e. in this case cold fluid is CuO we can observe from the graph the hot fluid temperature is decreasing and cold fluid temperature is increasing Due to hybrid nature of cold fluid i.e., nanofluid the Ribbed nature of the current volume and the thermal conductivity  result in the above plot. V. PLOTS COMPARISON  Figure 16:  Pressure comparison along length of plate with nanofluids The figure 16 represents the Comparison of Pressure Distribution Vs. length of the cold fluid i.e., SiO2 and the CuO the above pressure plot indicates that the slight variation in pressure i.e. increase in pressure when SiO2 is used than CuO although the same volumetric concentrations of the nanofluid is used the variable density levels in both fluids results in above plot.  Figure 17: Velocity comparison along the length of the plate with nanofluids The figure 17 represents the Comparison of Velocity Distribution Vs. length of the cold fluid i.e., SiO2 and the CuO the above Velocity plot indicates that the slight variation in Velocity i.e. increase in Velocity when SiO2 is used than CuO although the same volumetric concentrations of the nanofluid is used the nonlinear formation of volume and increase and decrease of the path where fluid flows results in such type of fluid behaviour.  Figure 18:  Temperature Distribution along the length of the plate with cold fluid The figure 18 represents the cold fluid Temperature (k) in y axis and Length (m) of the plate in X-axis From the graph, we can say that the wavy nature of the graph is because the rib channel temperature varies with both fluid i.e., SiO2 or CuO and solid plate the end temperature i.e. the outlet temperature of the hot fluid is decreasing with SiO2 nanofluid when compared to the   Figure 19: Temperature Distribution of Cold Fluid and Hot Fluid in CuO and SiO2 along the length of the plate The figure 19 comparison graph is between hot fluid in both the cases and Cold fluid i.e., Nano fluid SiO2 and CuO the x-axis represents length of the plate from inlet to outlet and the y axis represents the temperature (k) of the both hot fluid and cold fluid in both cases from the plot we can say that the hot fluid temperature is decreasing more in SiO2 case when compared with CuO and the cold fluid temperature is i.e., SiO2 temperature is increasing more when compared with CuO Comparison of Cold Fluid Properties between Sio2 CuO and Water  Figure 20:  Velocity Distribution along the plate with Cold Fluid as Water, SiO2 and CuO The figure 20 comparison plot represents the velocity Distribution of the both nanofluids with water we can say from the plot the x-axis represents length of the plate i.e., inlet to outlet and y-axis represents Velocity (m/s) we can observe from the graph the distribution of the water and CuO is almost same but when it comes to the SiO2 there is slight increase in velocity due to wavy nature of the volume we have designed.       Mohammed Rafeeq * et al. (IJITR) INTERNATIONAL JOURNAL OF INNOVATIVE TECHNOLOGY AND RESEARCH Volume No.5, Issue No.4, June – July 2017, 7010-7015. 2320 –5547 @ 2013-2017 http://www.ijitr.com All rights Reserved. Page | 7014  Figure 21: Pressure Distribution along The plate With SiO2, CuO and Water as Cold Fluid The figure 21 comparison plot represents the velocity Distribution of the both nanofluids with water i.e., SiO2 and the CuO the above pressure plot indicates that the slight variation in pressure i.e. increase in pressure when SiO2 is used than CuO although the same volumetric concentrations of the nanofluid is used the variable density levels in both fluids results in above plot  Figure 22:  Temperature Distribution along The plate With SiO2, CuO and Water as Cold Fluid. The figure 22 comparison plot represents the velocity Distribution of the both Nano fluids with water Temperature (K) in y axis and Length (m) of the plate in X-axis From the graph, we can say that the wavy nature of the graph is because the rib channel temperature varies with both fluid i.e., water SiO2 or CuO and solid plate the end temperature i.e., the outlet temperature of the hot fluid is decreasing with SiO2 nanofluid when compared to the CuO and water. VI. CONCLUSION In the present study, the heat transfer performance and fluid flow characteristics of various Nano fluids flowing in a counter flow PHE have been presented. The corrugated chevron PHE has been Analyzed, and the 3-D temperature and velocity fields have been obtained through CFD based analysis has been used by considering Nanofluids as homogeneous mixture. Analyzed results for various flow rates and particle volume concentrations. The significant conclusions derived from this work are highlighted below.  •Various Nano fluids have different optimum volume concentration in which the heat transfer characteristics show the maximum enhancement.  •A realistic but computationally less intensive geometrical model for plate heat exchanger was developed and testing of this model with water and Nano fluid as coolants was done.  •CFD results, which confirm that homogeneous mixture simulation can be effectively used to predict the Nano fluid, cooled plate heat exchanger.  •The Nano fluid is beneficial if and only if the increase in their thermal conductivity is increases despite undesirable effect of increase in viscosity.  •The rib pattern of the plate develops turbulence of fluid, which results in high heat transfer rates.  •The highest temperature appears around the upper port while the lowest temperature appears in the cold fluid inflow around the lower port, temperature gradient is larger, and effect of heat transfer is more satisfactory. In the present study SiO2 and CuO is taken as the nanofluid concentration which SiO2 processes the most heat transfer which has adequately shown in the graphs that are presented below VII. REFERENCES [1].  M.N. Pantzali, A.A. Mouza, S.V. Paras, Investigating the efficacy of nanofluids as coolants in plate heat exchangers (PHE), Chem. Eng. Sci.  [2]. M.N. Pantzali, A.G. Kanaris, K.D. Antoniadis, A.A. Mouza, S.V. Paras, Effect of nanofluids on the performance of a miniature plate heat exchanger with modulated surface, Int. J. Heat Fluid Flow.  [3]. W. Roetzel, S.K. Das, X. Luo, Measurement of the heat transfer coefficient in plate heat exchangers using a temperature oscillation technique, Int. J. HeatMass Transf. 37 (Suppl. 1) (1994)  [4]. Akers, W., Deans, H. & Crosser, O., 1959, Condensing Heat Transfer Within Horizontal Tubes, Chemical Engineering Progress Symposium Series 55. [5]. Boyko, L., Kruzhilin, G., 1967, Heat Transfer and Hydraulic Resistance during Condensation of Steam in Horizontal Tube and in a Bundle of Tubes, International Journal of Heat and Mass Transfer, vol. 10 no. 2: p. 361-373. [6]. Bromley, L., 1952, Effect of Heat Capacity of Condensate. Industrial Engineering Chemistry, vol. 44 no. 12: p. 2966-2969. [7]. Carpenter, E., Colburn, A., 1951, the Effect of Vapour Velocity on Condensation inside Tubes, IMechE/ASME: p. 20-26. [8]. Chen, M., 1961, an Analysis Study of Laminar Film Condensation, Part I - Flat Plates. ASME Journal of Heat Transfer, vol. 83: p. 48-55.       Mohammed Rafeeq * et al. (IJITR) INTERNATIONAL JOURNAL OF INNOVATIVE TECHNOLOGY AND RESEARCH Volume No.5, Issue No.4, June – July 2017, 7010-7015. 2320 –5547 @ 2013-2017 http://www.ijitr.com All rights Reserved. Page | 7015 [9]. M.N. Pantzali, A.A. Mouza, S.V. Paras, Investigating the efficacy of nanofluids ascoolants in plate heat exchangers (PHE), Chem. Eng. Sci. 64 (2009). [10]. 10. M.N. Pantzali, A.G. Kanaris, K.D. Antoniadis, A.A. Mouza, S.V. Paras, Effect ofnanofluids on the performance of a miniature plate heat exchanger. [11]. 11. Yan, Y., Lio, H., Lin, T., 1999, Condensation Heat Transfer and Pressure Drop of Refrigerant R-134a in a Plate Heat Exchanger, International Journal of Heat and Mass Transfer, vol. 42: p. 993-1006. [12]. 12. Han, D., Lee, K., Kim, Y., 2003, the Characteristics of Condensation in Brazed Plate Heat Exchangers with Different Chevron Angles, Journal of the Korean Physical Society, vol. 43 no. 1: p. 66-73. [13]. Jokar, A., Hosni, M., Eckels, S., 2006, Dimensional Analysis on the Evaporation and Condensation of Refrigerant R-134a in a Minichannel Plate Heat Exchanger, Applied Thermal Engineering, vol. 26: p. 2287-2300. [14]. S. Jain, A. Joshi, P.K. Bansal, A new approach to numerical simulation of smallsized plate heat exchangers with chevron plates, J. Heat Transf. 129 (2007). AUTHOR BIOGRAPHY  MOHAMMED RAFEEQ was born in Gulbarga, Karnataka, India in 1993. He received the B.E degree   in   Mechanical   Engineering from Khaja Banda Nawaz college of Engineering, Kalaburagi. Pursuing M.Tech degree in Thermal Power Engineering from PDA College of Engineering, Kalaburagi, and Karnataka, India.  M.R NAGARAJ B.E from Sri Jayachamarajendra College of Engineering, Mysore and M.E (Thermal) from PDA College of Engineering, Kalaburagi. Present working as associate professor at PDA College of Engineering and He has 33Years of teaching Experience in the areas of thermal engineering. 

CFD INVESTIGATION OF PLATE HEAT EXCHANGER USING NANOFLUIDS

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CFD INVESTIGATION OF PLATE HEAT EXCHANGER USING NANOFLUIDS

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