International Conference on Global Trends in Engineering, Technology and Management (ICGTETM-2016) Experimental and Computational Fluid Dynamics Analysis of a New Flat Plate Solar Collector Ashish N. Sarode#1, Dr. Atul A. Patil*2, V.H.Patil#3 # M.E. Student, Department of Mechanical Engineering, GF's Godavari College of Engineering, Jalgaon, Maharashtra, India. * Associate Professor, Department of Mechanical Engineering, GF's Godavari College of Engineering, Jalgaon, Maharashtra, India. # Associate Professor, Department of Mechanical Engineering, GF's Godavari College of Engineering, Jalgaon, Maharashtra, India. Abstract—This paper present the investigation of performance and reliability of a new design flat plate solar collector.Flat plate collector is one of the important solar energy trapping device which uses air or water as working fluid. Usually all flat plate collectorabsorbers are made up ofcopper or aluminium sheets, which limits on the heat collection surface transfer area.The specific objective of this study is to develop new models and improved the efficiency of the solar water heater by exchanging the absorber & copper tube arrangement with fabrication of a simple copper box as a collector.The Computational Fluid Dynamics (CFD) software has been used for simulation of new flat plate collector. Experimentation conducted on new flat plate collector for particular period ofvarious days and data is maintained as per days.The experimental results of water outlet temperature are validated with the results obtained by using computational fluid dynamics (CFD) tool and there is a good agreement in between them. Keywords—Flat Plate Solar Collector (FPSC),Solar water heater, Computational Fluid Dynamics (CFD). I. INTRODUCTION The rate at which the non-renewable energy are utilized or depleted it is need to be focus on renewable energy resources. Many types of renewable energy are available but conversion technology of this energy into usable form is not effectively and more complicated. The sun is a good example of those resources which undergo a faster replenishment rate within a relatively short time than the rate at which non-renewable energy is utilized or depleted[1]. The energy of the sun is generated from the nuclear fusion of its hydrogen into helium, with a resulting mass depletion rate of approximately 4.7 × 106 tons per second. The earth’s population currently needs 15 terawatts of power in total, but the solar radiation that reaches the earth on a continuous basis amounts to 120,000 terawatts; only fraction of the suns energy reaching the earth will cover the bulk of energy requirements [2]. The sun is a sphere of intensely hot gaseous matter with a diameter of 1.39 X 109 m. The solar energy ISSN: 2231-5381 strikes our planet a mere 8 min and 20 s after leaving the giant furnace, the sun which is 1.5 X 10 11 m away. The sun hasan effective blackbody temperature of 5762 K [3].Now-a-days, 80% of total energy is produced by means of fossil fuels, and this massive utilization is leading to the overtiredness of these resources and imposes a real threat to the environment, mainly through global warming and acidification of water cycle[4]. The demand for renewable energy is increasing due to the rapid growth of industrialization and the excessive use of fossil fuels which has adverse effects on global climate change. Solar energy is one of the cleanest, most abundant and environmental friendly sources of renewable energy. To obtain maximum thermal energy from incident solar radiation, welldeveloped solar conversion technology today solar water heaters with different configurations and designs have been used for various applications [5], [6], [7], [8], [9]. Solar water heaters play a vital role in low temperature applications especially in domestic sector. Solar water heater is one of the most successful solar technologies. Currently, world’s demand of energy has dramatically increased; furthermore, process to collect hot water by solar radiation is expensive [10]. The use of solar water heaters (SWH) is encouraged to produce domestic hot water because SWH can substantially reduce primary energy consumption compared with conventional water heaters [11].Flat plate collectors (FPC) are the most used type of collector. FPC is usually employed for low temperature applications up to 100 0C, although some new types of collectors employing vacuum insulation can achieve slightly higher values [12].A typical flat plate collector is shown in figure 1. http://www.ijettjournal.org Page 455 International Conference on Global Trends in Engineering, Technology and Management (ICGTETM-2016) . Fig. 1 A typical flat plate collector II. CONSTRUCTIONAL DETAILS A passive system was selected as the basis for the design of flat plate collectors which do not necessitate any electricity and relay. Principle of passive system is based on natural circulations of hot water, gravity feed and water pressure. A new flat-plate solar collector has the simplest designs and requires neither tracking nor as much maintenance as the other collector designs.In passive type flat plate collector, we changed the copper tubes arrangement by simple putting a copper box as flat plate of dimensions 1100 x 1100 x 15 mm in collector frame. The thickness of copper flat plate is 1 mm having 22 gauges.Figure 2 shows the realview of new flat plate collector. FPC is usually permanently fixed in position and requires no tracking of the sun. The collectors should be oriented directly towards the equator, facing south in the northern hemisphere and north in the southern. The optimum tilt angle of the collector is equal to the latitude of the location with angle variations of 10–150 more or less depending on the application [13]. The solar radiation is incident on the absorber plate. The absorber plate is made of copper material because of its high thermal conductivity which will rapidly absorb heat from sun's rays and quickly transfer that heat to the tubes or fins which will transfer heat to thewater[14], [15]. The main pipe is made of material Fig. 2 Real view of new flat plate collector of copper to transfer the absorbed heat to the water, a dark-coloured shows the absorber and a cover The copper boxis fixed in collector frame with a glass[16]. Casing is providing to the collector to transparent cover to reduce the convection and reduce the heat transfer losses by convection and radiation losses. The casing is made of aluminium radiation. It is made of Aluminium or wooden material with black painted. The provision for feed waterfrom depending upon the applications [17].Most solar water the water tank at the inlet as given from lower side of heater designs used for single family are closed and the frame into the copper box and outlet of hot water opened solar water heating systems. These two is given from the another end. The rise of the water systems are categorized into two groups:forced temperature inside the copper box collector is due to circulation and natural convection. The advantages of the absorption of incident solar radiation which gives thermosyphon systems are more reliable and longer rise to water uprising motion by thermosyphon life than forced circulation systems with no need of principle.The technical specifications of solar water pumps and controllers[18], [19]. heating system are given in Table I. Manjunath M S states foranunglazed solar collector with an innovative serratedfined tube as well as TABLE I another diametrically placed planar fin bifurcating the TECHNICAL SPECIFICATIONS OF NEW FLAT PLATE absorber tubepassage increases the heat transfer flux COLLECTOR by lowering the flow rates. These results validated using Computational fluid dynamics[20]. The Particular Specification objective of this work is to experimentally investigate the water outlet temperature of solar flat plate Collector dimensions (Length 1.25 m x 1.25 m x 0.080 m x Width x Thickness) collector.Fluid flow and heat transfer in the collector panel are studied by means of computational fluid Collector type Flat plate dynamics (CFD) simulation.The measured Number of glass covers 1 experimental temperatures are compared to the Cover material Low iron glass temperatures determined by the CFD model and there Cover thickness 4 mm is a good similarity between the measured and calculated results.The influences of different operating Cover transmission 94% conditions such as flow rate, properties of solar Box dimensions 1.1 m x 1.1 m collector fluid, solar collector fluid inlet temperature (Length x Width) are studied[21]. ISSN: 2231-5381 Thermal conductivity of plate material 386 W/m °C Copper sheet thickness 1 mm (22 gauge) http://www.ijettjournal.org Page 456 International Conference on Global Trends in Engineering, Technology and Management (ICGTETM-2016) Collector heat absorber area 1.44m2 Insulation material Rockwool Thermal conductivity of insulating material 0.045 W/m °C Insulation thickness 30 mm Sheet Material of collector tray Aluminium flat plate collectors are oriented in south direction that it receives maximum solar radiation. Two digital thermometers are required whose ranges up to 150 0C for measurement inlet and outlet temperatures. Digital Thermometer 1 is fitted in the inlet of solar water heating system for measuring the inlet cold water temperature and Thermometer 2 is fitted in the exit of the collector for measuring the hot water temperature.Flow meter is also fitted in the inlet side system to measure the flow of water before the water is admitted in the collector. The 3-D view of copper made flat plate collector is as shown in figure 3. Fig. 5The closed view of Experimental setup for solar water heating system Fig. 3 3Dview of flat plate collector III. EXPERIMENTAL SETUP AND PROCEDURE 1) Experimental setup: The tests were conducted at the GF’s Godavari college of Engineering, Jalgaon (20.9980°N,75.5667°E), State- Maharashtra, India. The schematic diagram of the thermosyphon flat plate solar water heating system is shown in figure 4. The system consists of flat plate collectors, storage tank and connecting pipes. The flat plate collectors are oriented in south direction that it receives maximum solar radiation.Figure 4 shows the schematic representation of experimental setup [22]. Fig. 4 Schematicrepresentation ofExperimental Setup Figure 5 shows the closed view of experimental setup for solar water heating system.The system consists of flat plate collectors, two digital thermometer, flow meter and connecting pipes.The ISSN: 2231-5381 2) Procedure for test Run: The cold water storage tank filled with 500 litres of water after proper filtration. The valve was opened to allow water flow to the circulating pipes. Water flows through the collector at a constant flow rate during all the measurements. A part ofincidence solar radiation on the glass cover is reflectedback to atmosphere and remaining is transmitted inside thesolar collectors and the solar radiation is absorbed by the water.Due to the absorption of solar radiation, water temperature increases and the water starts emitting long wavelength radiation which is not allowed to escape to atmosphere due to presence of glass cover. The insulation provided at the bottom and all the sides of solar collectors and glass cover serves the purpose of reducing direct convective losses to the ambient which further becomes beneficial for rise in water and solar collectors temperature respectively.The heated water moves upward due to decrease indensity whereas the colder working fluid settled at thelower portion due to more in density. The hot water is collected from the outlet which isconnected to the solar hot water storage tank which has a valve to allow tapping when needed for use. Cold watertemperature (0C), solarcollector temperature (0C), ambient temperature (0C) and hot water temperature (0C) were recorded at 1 hour intervals. http://www.ijettjournal.org Page 457 International Conference on Global Trends in Engineering, Technology and Management (ICGTETM-2016) The results were recorded after performing the measurement of important operating parameters of the experimental setup at selected location as per the procedure specified during the experimental work. The tests were conducted from 11.00 A.M. to 5.00 P.M. hourly. Throughout the complete trials conducted, theday was sunny and no any cloudy conditions were present[23]. high temperature and pressure gradients are finely meshed.Meshing domain of flat plate collector is IV.CFD SIMULATION 1) Modeling of Flat Plate Collector: The 3-D model for new flat plate collector is created using CAD Package CATIA V5 R19. It is imported in Ansys fluent workbench. The extra length added for pipe at inlet and outlet flat plate collector which helps in reducing the non-uniformity of flow. The geometrical specifications of the flat plate collector have chosen somewhat arbitrarily. Collector box is 1100 x 1100 mm. Inlet and outlet tube diameter is di=d0=0.01m and thickness 15mm of copper material. Generally this model is designed and applying heat transfer from top face to fluid present in the flat plate collector.The model of flat plate collector is shown in figure 6. Fig. 6Model of flat plate collector Then all the parts are defined i.e. inlet is defined as Inflow, outlets as Outflow and Top Face. shown in figure 7. Fig. 7Meshing domain of flat plate collector 3. Physics of The Simulation For CFD Analysis: a) Initial Assumptions: Keeping inlet temperature to new flat plate collector constant for each observations and mass flow rate of water assumed arbitrarily for inlets of new flat plate collector. b) Viscous Model: The laminar model is selected to analyze the heat transfer and contour presentation. Energy model is set to ON position which permits heat transfer analysis. 2. Grid Generation of Flat Plate Collector: The ANSYS ICEM-CFD is used for discretization of domain. Initially a relatively coarser mesh is generated. This mesh contains tetrahedral cells having triangular faces at the boundaries. Care is taken to use tetrahedral cells as much as possible. It is meant to reduce numerical diffusion as much as possible by structuring the mesh in a well manner, particularly near the wall region. Later on, a fine mesh is generated for this fine mesh, the edges and regions of ISSN: 2231-5381 http://www.ijettjournal.org Page 458 International Conference on Global Trends in Engineering, Technology and Management (ICGTETM-2016) c) Boundary Conditions: Boundary conditions are used according to the need of the model. Boundary conditions used at inlets are mass flow rate of water and at outlets static pressure is applied. d) Solver Parameters: The high resolution scheme and Auto-time scale is used for convergence control. The convergence criteria are RMS residual type and convergence rate 1e-03 is used for mass and momentum etc. which gives the water outlet temperature from flat plate collector configuration after certain number of iterations. The general FLUENT simulation model of flat plate collector is shown infigure 8. Fig. 9 Variations in water outlet temperature vs. Daysat 3 P.M. The experimental test has been carried out at 11 A.M. to 5 P.M. hourly for five consecutive days from 1st to 5th April 2015.It is observed from the figure 9 water outlet temperature from simulation of new flat plate collector is greater than experimental results. Increase in water outlet temperature of about2 to 6 % in simulation of new flat plate collector as compared to experimental results. New flat plate collector shows maximum water outlet temperature around 3 P.M. Increase in water outlet temperature for new flat plate collector is due to increase in heat transfer area. VI. CONCLUSIONS Fig. 8FLUENT simulation model of flat plate collector The general simulation parameters with solid fluid assembly are summarized as given below in table II. TABLE II DETAILS OF SIMULATION PARAMETER Parameter Ansys Fluent Domain of simulation Flat plate collector Laminar model Viscous Heat Transfer model Thermal Energy Fluid Water Solid Copper Reference Pressure 1 atm. Inlet Mass flow rate and ACKNOWLEDGMENT Temperature of Fluid Outlet Static pressure Discretization High Resolution V. RESULT AND DISSCUSSION 88 Temperature (0C) The following conclusions may be drawn from the present study that new Flat plate solar water collector is successfully designed through Experimental analysis and validated using CFD simulation. The new proposed design increase heat transfer rate by increasing surface collector area. 1. It is observed from experimental results; the water outlet temperature from collector is linearly increases with increase in day passes. 2. It is also concluded from the results that the maximum outlet temperature is reached at 3.00 P.M on 5th April with a maximum temperature up to 850 C experimentally. 3. It has been observed that outlet temperature of water in simulation greater than experimental results of particular days. 87 I wish tothank Dr. D. S. Deshmukh, HO.D. 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