Simulation of Two Pass Solar Air Heater using Matlab By, Avinash v Dharwadkar USN:2BV10MES04
Simulation of Two Pass Solar Air Heater using Matlab
By,
Avinash v Dharwadkar
USN:2BV10MES04
Contents
• Problem definition
• Objectives
• Introduction
• Classification of FPC
• The majority of flat plate collector main component
• Insulation and casing
• SAH classification
Contents
• Application of solar air heaters
• Advantages of solar air heaters
• Disadvantages of solar air heaters• Literature Survey
• Specification
• Packed Bed
• Steel mesh as a packing material
• Porous solar air heaters
Contents
• Nonporous solar air heaters
• V groove nonporous solar air heaters
• V groove porous solar air heaters
• Results
• Conclusion
• References
Akoweldement
1)K. Sopian , M.A. Alghoul , Ebrahim M. Alfegi , M.Y. Sulaiman , E.A. Musa
2)Suppramaniam satcunanathan
and Stanley deonarine
3) N. E. Wijeysundera, Lee ah and Lim Ek Tjioe
4) Bashria A. A. Yousef and Adam N. M,Analysis of Single and Double Passes With and Without Porous Media for V-groove absorber
• The study involves the predicting the better solar air heaters and high performance air heaters for the purpose of crop drying, space heating etc.
• Efficiency involved with the losses. Considering losses predicting efficiency for different conditions like nonporous,porous,Vgroove porous,Vgroove nonporous solar air heaters.
• Among the above mentioned types of solar air heaters checking their performances for different variable parameters like pressure drope, flow depth variations,outlet tempreture, and mass flow rate.
Problem definition
Objectives
• To show the performance of two pass solar air heaters using MATLAB.
• Comparing the results of nonporous and porous media used in the second channel of the air heaters.
• Effect of porous media on Nussult number and Reynolds number by results obtained from the Matlab.
Classification of FPC
• Based on the type of the heat transfer fluid used can be divided into two main classifications;
• Liquid heating collector
• Air or Gas heating collector
Introduction
• It is solar collector device for collecting solar radiation and transfer the energy to a fluid passing in contact with it.
• Where temperature below 900 C are adequate, flat plat collector are convenient.
• They are made in about 1.7 to 2.9 sq.m in area and are relatively simple to construct and erect.
• They can absorb both direct and diffused radiation.
• They are consequently effective even on cloudy days when there is no direct radiation.
Construction of FPC
• When temperature is below about 900C is adequate they are for space heating and service water heating flat plate collector
Which are non concentrating type. are particularly convienient.They are made in rectangular panels, from about 1.5 to 2.9square meter in area.
The majority of flat plate collectorhave main components as follows
• A transparent cover which may be one or more sheets of glass or radiation transmitting plastic film or sheets.
• Tubes,fins,passages or channels are integral with the collector absorber plate pr connected to it which carry the water, air or other fluid.
• The absorber plate, normally metallic or with a black surface although a wide variety of other materials can be used with air heaters
Insulation and casing
• Insulating materials, which should be provided at back and sides to minimize the heat losses. Standard insulating materials like glass wool ,styro foam are used for this purpose.
• The casing or container which enclose the other components and protect from weather.
• Heat is transferred from the absorber plate to the point of use by circulation of fluids across the solar heated surface. Thermal insulation of 5 to 10 cm thickness is usually placed behind the rear surface. insulation materials is generally mineral wool, glass wool .
Continued…
• The front covers are generally glass that is transparent to in coming solar radiation and opaque to the infrared re-radiation from the absorber. The glass cover acts as a convection shield to reduce losses from the absorber plate .Glass is most favorable materials.Its thickness is 3 to 4mm.
SAH classification
• Air heaters are classified into two categories
Nonporous: In this kind air passes directly on the absorber plat
Porous absorber : in this kind air passes through the porous materials
Application of solar air heaters
The solar air heaters which supply hot air could be mainly used for the following purposes:
• Heating buildings
• Drying agricultural products.
• Heating green house.
• Space heating.
• Seasoning of timber
• Curing of industrial products
Advantages of solar air heaters
• The use of air as heat transport fluid eliminates both freezing and corrosion problems
• Small air leakage are less concern than the water leaks
• The heated air can directly used for space heating while in water heating it can not be used directly for the same purpose.
Disadvantages of solar air heaters
• Need to handling larger volume of air.
• Thermal capacity of air is low.
• They have relatively high fluid circulation costs.
• Relatively larger volume of storage.
• They have higher noise level.
• Space is required for ducting.
Literature Survey
• K. Sopian, M.A. Alghoul
Evaluation of thermal efficiency of double-pass solar collector with porous–nonporous media
Introducing porous media in the second channel increases the heat transfer area. This type of collector has a higher thermal performance compared to the conventional single- pass solar collector. Typical thermal efficiency of the double pass solar collector with porous media is about 60–70%.
Literature Survey
• K. Sopian etall
Analysis of Single and Double Pass Solar Collector With and Without Porous Media
• It is found that increasing the mass flow rate through the air heaters results in higher efficiency but also there is increased pressure drop.
Literature Survey
Elradi A. Musa Et all.
• In the double-pass solar collector, the mass flow rate has more effect on the temperature rise. The solar radiation has more effect on temperature rises at low porosity. In addition, the Reynolds number has more effect than the Nussult number at low porosity. Heat transfer coefficient increases by using more porous media in the lower channel of the double-pass solar collector
Literature Survey
• The double flow is more efficient than the single flow made and the using of porous media increase the system efficiency and the outlet temperature. This increment will result in the increase of the pressure drop thus increasing the pumping power expanded in the collector.
• Higher porosities in the porous media improved the thermal efficiency. Pressure drop study indicated that lower pressure losses are encountered with low porosity than with high porosity of the saturated porous media.
Introduction of Matlab
• The name MATLAB stands for matrix laboratory. MATLAB was originally written to provide easy access to matrix
software developed by the LINPACK and EISPACK projects.• In university environments, it is the standard instructional tool
for introductory and advanced courses in mathematics, engineering, and science.
• In industry, MATLAB is the tool of choice for high-productivity research, development, and analysis. MATLAB features a family of add-on application-specific solutions called toolboxes.
Introduction of Matlab
• Very important to most users of MATLAB, toolboxes allow you to learn and apply specialized technology. Toolboxes are comprehensive collections of MATLAB functions (M-files) that extend the MATLAB environment to solve particular classes of problems. Areas in which toolboxes are available include signal processing, control systems, neural networks, fuzzy logic, wavelets, simulation, and many others.
Porous flat plate solar air heaters
Specification• L = 2.4m• W = 1.2m• d = 0.02 to 0.07m• Glass martial emissivity = 0.95• Plate emissivity = 0.95• Plate absorbtvity = 0.92• Reflectivity of plate = 0.15• Plate thickness = 2mm• Glass thickness = 3mm• Insulation thickness on side and back = 0.05m• Density = 1.29Kg/m3
• Absolute viscosity = 19*10-6 kg/ms• Specific heat of air = 1.005 kJ/kgK• Thermal conductivity of the insulation = 0.045kw/mk
Packed Bed
• The packed bed solar air heaters means filling the porous materials in the channels of solar air heaters
• Materials are used are steel mesh, crushed glass,glass wool ect.
• Pressure drop is more in the packed bed than the usual solar air heaters.
• Hence pumping power required is more.
Nonporous solar air heaters
Pressure drop vsflow depth
Efficiency vs flow depth
Outlet temp,efficiency vs mass flow rate
Reynolds number
Heat transfer coefficient
Porous solar air heaters
Pressure drop vs flow depth
Efficiency vs flow depth
Outlet temp,efficiency vs massflow rate
Heat transfer coeffiicent
Reynolds number
V-groove nonporous solar air heaters
Pressure drop vs flow depth
Efficiency vs flow depth
Outlet temp,efficiency vs mass flow rate
Heat transfer coefficient
Reynolds number
V-groove porous solar air heaters
Pressure drop vs. flow depth
Efficiency vs. flow depth
Outlet temp,efficiency vs. mass flow rate
Heat tansfer coefficient
Reynolds number
Results
Types of solar
air heaters
Efficiency
considering
mass flow
rate,m
η considering
Flow depth,m
Pressure drop
(pa)considering
Flow depth
Outlet
temperature (c)
Reynolds
Number
Nussult
number
Nonporous 64 64 4 45 16000 10
porous 73 73 5 50 10000 25
V-groove
nonporous65 65 8.5 45.5 3000 12
V-groove
porous66 65.5 9 50 2500 20
Percentage differencesTypes of solar air
heaters
% in increase in
efficiency considering
mass flow rate
% increase in the
efficiency considering
flow depth
% increase in the
pressure drop
% increase in the outlet
temperture,c
Porous solar air heaters 14% 14% .25% 11.23%
V-groove nonporous
Solar air heaters1.5% 1.56% 1.125% 13.3%.
V- groove porous Solar
air heaters2.34% 2.34% 1.25% 0.111%
Conclusion
• The Nussult number values are less in the nonporous than in the porous because the heat transfer reduces in nonporous media.
• The Nussult number values are more in the porous than in the nonporous because the heat transfer increases in porous media.
• The Reynolds number is more in the nonporous due to higher velocity of air due to free flow through the ducts.
• The Reynolds number is less in the porous due to lower velocity of air due to flow through the packed ducts.
• Efficiency is increases with increase in mass flow rate.
Conclusion• Outlet temperature decreases with the increase in mass flow
rate.• Efficiency decreases with increase in the channel depth.• In two pass solar air heaters variables like efficiencies,
pressure drop ,outlet tempreture,friction factors ,collector efficiency factors ,collector flow factor in flat plate porous and nonporous ,V groove porous and non porous obtained through Matlab programming is almost equal.
• Efficiencies of four types of collectors are between 60% to 73%.
• Pressure drop for four types of collectors varied between 2 to 17 Pascal’s.
• Reynolds number varied between 600 to 16000.
Conclusion
• Nussult number varied between 3 to 40.
• The highest efficiency obtained from the flate plate porous kind of solar air heaters.
• The outlet temperature is maximum in flat plate with porous solar air heaters.
• The outlet temperature is minimum in V groove plate with porous solar air heater.
• Pressure drop is directly proportional to length of the collector more length is leads more pressure drop and more pumping power is requared.
References
[1] K. Sopian a, M.A. Alghoul , Ebrahim M. Alfegi b, M.Y. Sulaiman , E.A. Musa, Evaluation of thermal efficiency of double-pass solar collector with porous–nonporous media.
[2] B. A. A. Yousef and N. M. Adam, Thermal Performance and Economic Effectiveness for Solar Air Heaters: Analysis and Expert System Developments
[3] Bashria A. A. Yousef and Adam N. M,Analysis of Single and Double Passes With and Without Porous Media for V-groove absorber.
[4] A. A. Shabaneh, P. Gandhidasan, M. A. Antar and H. Baig,Simulation of hdh desalination system using tilted, two-pass solar air heater.
[5] Adisu Bekele , Manish Mishra, Sushanta Dutta,Effects of delta shaped obstacles on the thermal performance of solar air heater.
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factor correlations for packed bed solar air heaters for a low porosity system
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heaters.[11] Suppramaniam Satcunanathan and Stanley Deonarine,A
two-pass solar air heater[12] N. E. Wijeysundera,Lee lee ah and Lim Ek Tjioe,Thermal
performance study of two-pass solar air heaters.
References
[13] Ahmad Fudholi, Kamaruzzaman Sopian, Mohd Hafidz Ruslan, Mohd. Yusof Othman and Muhammad Yahya, Analytical and Experimental Studies on the Thermal Efficiency of the Double-Pass Solar Air Collector with Finned Absorber
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[15] Amrita Agrawal, Nalin Deshpande, Aakanksha Dubey, Design, Fabrication & Performance Analysis of Solar air heater.
[16] Rai.G.D, Solar Energy Utilization
[17]S.P.Sukahtme,Solar Energy
References[[18]Rudra Pratap, Getting Started with Matlab[19]H.P.Garg,J.Prakash,Solar energy Fundamentals and
Applications[20] www.sciencedirect.com[21] www.mathworks.com
[22] C. Choudhuryp, . M. Chauhana and H. P. Garg,Performance and cost analysis of two-pass solar air heaters.
[23] Bashria A, A. Yousef and Adam N. M, K Sopian, A. Zaharim and M. Alghoul,Analysis of Single and Double Passes V-Grooves Solar Collector With and Without Porous Media.
Thank you