This document discusses various parameters that affect the performance of liquid flat plate solar collectors (LFPCs). It describes the typical construction of an LFPC, including a rectangular casing with an absorber plate and tubes to circulate a heat transfer fluid. Key parameters discussed include selective absorber coatings, the number of glass covers, spacing between components, and materials used. The document also examines how geometric factors, insulation, and other variables like working fluid and absorber porosity can impact efficiency. It concludes that major losses occur through the top of collectors and that efficiency can be improved by optimizing design elements to reduce heat loss.
Solar collector : A device designed to absorb incident solar radiation and to transfer the energy to a fluid passing in contact with it, usually liquid or air.
Flat – Plate Collector : A typical flat-plate collector is an insulated metal box with a glass or plastic cover (called the glazing) and a dark-colored absorber plate. These collectors heat liquid or air at temperatures less than 180°F.
Solar Energy Storage:-
Methods of storage such as sensible, latent heat &
thermochemical storage,selection of method of storage,
properties of storage materials and different arrangements of
storages
Solar collector : A device designed to absorb incident solar radiation and to transfer the energy to a fluid passing in contact with it, usually liquid or air.
Flat – Plate Collector : A typical flat-plate collector is an insulated metal box with a glass or plastic cover (called the glazing) and a dark-colored absorber plate. These collectors heat liquid or air at temperatures less than 180°F.
Solar Energy Storage:-
Methods of storage such as sensible, latent heat &
thermochemical storage,selection of method of storage,
properties of storage materials and different arrangements of
storages
This project is about conducting an experimental study on solar heated pipe with parabolic trough reflector. The effect of different parameters on the solar heated pipe will be analyzed for optimum design. Design and construction of the experimental setup for the above study is discussed.
Different parameters which are analyses as follows: Size and thickness of the pipe, size of the casing, flow rate of the fluid, type of fluid, angle of inclination of rim, design parameters etc. These variables will be compared by the efficiency of the solar heated pipe.
Water billing management system project report.pdfKamal Acharya
Our project entitled “Water Billing Management System” aims is to generate Water bill with all the charges and penalty. Manual system that is employed is extremely laborious and quite inadequate. It only makes the process more difficult and hard.
The aim of our project is to develop a system that is meant to partially computerize the work performed in the Water Board like generating monthly Water bill, record of consuming unit of water, store record of the customer and previous unpaid record.
We used HTML/PHP as front end and MYSQL as back end for developing our project. HTML is primarily a visual design environment. We can create a android application by designing the form and that make up the user interface. Adding android application code to the form and the objects such as buttons and text boxes on them and adding any required support code in additional modular.
MySQL is free open source database that facilitates the effective management of the databases by connecting them to the software. It is a stable ,reliable and the powerful solution with the advanced features and advantages which are as follows: Data Security.MySQL is free open source database that facilitates the effective management of the databases by connecting them to the software.
ACEP Magazine edition 4th launched on 05.06.2024Rahul
This document provides information about the third edition of the magazine "Sthapatya" published by the Association of Civil Engineers (Practicing) Aurangabad. It includes messages from current and past presidents of ACEP, memories and photos from past ACEP events, information on life time achievement awards given by ACEP, and a technical article on concrete maintenance, repairs and strengthening. The document highlights activities of ACEP and provides a technical educational article for members.
Hierarchical Digital Twin of a Naval Power SystemKerry Sado
A hierarchical digital twin of a Naval DC power system has been developed and experimentally verified. Similar to other state-of-the-art digital twins, this technology creates a digital replica of the physical system executed in real-time or faster, which can modify hardware controls. However, its advantage stems from distributing computational efforts by utilizing a hierarchical structure composed of lower-level digital twin blocks and a higher-level system digital twin. Each digital twin block is associated with a physical subsystem of the hardware and communicates with a singular system digital twin, which creates a system-level response. By extracting information from each level of the hierarchy, power system controls of the hardware were reconfigured autonomously. This hierarchical digital twin development offers several advantages over other digital twins, particularly in the field of naval power systems. The hierarchical structure allows for greater computational efficiency and scalability while the ability to autonomously reconfigure hardware controls offers increased flexibility and responsiveness. The hierarchical decomposition and models utilized were well aligned with the physical twin, as indicated by the maximum deviations between the developed digital twin hierarchy and the hardware.
Online aptitude test management system project report.pdfKamal Acharya
The purpose of on-line aptitude test system is to take online test in an efficient manner and no time wasting for checking the paper. The main objective of on-line aptitude test system is to efficiently evaluate the candidate thoroughly through a fully automated system that not only saves lot of time but also gives fast results. For students they give papers according to their convenience and time and there is no need of using extra thing like paper, pen etc. This can be used in educational institutions as well as in corporate world. Can be used anywhere any time as it is a web based application (user Location doesn’t matter). No restriction that examiner has to be present when the candidate takes the test.
Every time when lecturers/professors need to conduct examinations they have to sit down think about the questions and then create a whole new set of questions for each and every exam. In some cases the professor may want to give an open book online exam that is the student can take the exam any time anywhere, but the student might have to answer the questions in a limited time period. The professor may want to change the sequence of questions for every student. The problem that a student has is whenever a date for the exam is declared the student has to take it and there is no way he can take it at some other time. This project will create an interface for the examiner to create and store questions in a repository. It will also create an interface for the student to take examinations at his convenience and the questions and/or exams may be timed. Thereby creating an application which can be used by examiners and examinee’s simultaneously.
Examination System is very useful for Teachers/Professors. As in the teaching profession, you are responsible for writing question papers. In the conventional method, you write the question paper on paper, keep question papers separate from answers and all this information you have to keep in a locker to avoid unauthorized access. Using the Examination System you can create a question paper and everything will be written to a single exam file in encrypted format. You can set the General and Administrator password to avoid unauthorized access to your question paper. Every time you start the examination, the program shuffles all the questions and selects them randomly from the database, which reduces the chances of memorizing the questions.
Harnessing WebAssembly for Real-time Stateless Streaming PipelinesChristina Lin
Traditionally, dealing with real-time data pipelines has involved significant overhead, even for straightforward tasks like data transformation or masking. However, in this talk, we’ll venture into the dynamic realm of WebAssembly (WASM) and discover how it can revolutionize the creation of stateless streaming pipelines within a Kafka (Redpanda) broker. These pipelines are adept at managing low-latency, high-data-volume scenarios.
KuberTENes Birthday Bash Guadalajara - K8sGPT first impressionsVictor Morales
K8sGPT is a tool that analyzes and diagnoses Kubernetes clusters. This presentation was used to share the requirements and dependencies to deploy K8sGPT in a local environment.
CHINA’S GEO-ECONOMIC OUTREACH IN CENTRAL ASIAN COUNTRIES AND FUTURE PROSPECTjpsjournal1
The rivalry between prominent international actors for dominance over Central Asia's hydrocarbon
reserves and the ancient silk trade route, along with China's diplomatic endeavours in the area, has been
referred to as the "New Great Game." This research centres on the power struggle, considering
geopolitical, geostrategic, and geoeconomic variables. Topics including trade, political hegemony, oil
politics, and conventional and nontraditional security are all explored and explained by the researcher.
Using Mackinder's Heartland, Spykman Rimland, and Hegemonic Stability theories, examines China's role
in Central Asia. This study adheres to the empirical epistemological method and has taken care of
objectivity. This study analyze primary and secondary research documents critically to elaborate role of
china’s geo economic outreach in central Asian countries and its future prospect. China is thriving in trade,
pipeline politics, and winning states, according to this study, thanks to important instruments like the
Shanghai Cooperation Organisation and the Belt and Road Economic Initiative. According to this study,
China is seeing significant success in commerce, pipeline politics, and gaining influence on other
governments. This success may be attributed to the effective utilisation of key tools such as the Shanghai
Cooperation Organisation and the Belt and Road Economic Initiative.
We have compiled the most important slides from each speaker's presentation. This year’s compilation, available for free, captures the key insights and contributions shared during the DfMAy 2024 conference.
Literature Review Basics and Understanding Reference Management.pptxDr Ramhari Poudyal
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A review on techniques and modelling methodologies used for checking electrom...nooriasukmaningtyas
The proper function of the integrated circuit (IC) in an inhibiting electromagnetic environment has always been a serious concern throughout the decades of revolution in the world of electronics, from disjunct devices to today’s integrated circuit technology, where billions of transistors are combined on a single chip. The automotive industry and smart vehicles in particular, are confronting design issues such as being prone to electromagnetic interference (EMI). Electronic control devices calculate incorrect outputs because of EMI and sensors give misleading values which can prove fatal in case of automotives. In this paper, the authors have non exhaustively tried to review research work concerned with the investigation of EMI in ICs and prediction of this EMI using various modelling methodologies and measurement setups.
3. LFPC (Liquid Flat Plate Collector).
Most common type of collector.
Simple in design and constructing.
Used for domestic water heating applications.
If the fluid is liquid then it is liquid flat plate collector.
Usually LFPC are stationery and they do not need any tracking.
Saturday, April 16, 2016 3
5. Constructional Features
• Usually rectangular case, open at top side, insulation at sides and bottom.
• Heat transfer fluid flowing through the conduits( headers, tubes) which are
attached over or underneath the absorber plate.
• There is transparent cover closing the face of LFPC.
• LFPC casing is usually made up of wood or aluminium.
• Insulation material is glass wool( due to its stability at high temperatures) and it
is up to 25mm-100mm thick.
• Mineral wool, rock wool is also used as insulation material.
• Absorber generally is made of copper metal due to its high conductivity and is
0.2mm to 0.7mm thick.
Saturday, April 16,
2016 5
6. Constructional Features(cont’d)
• aluminium , steel is also used as absorber material.
• Absorber is spray painted black, and heat treated to improve bonding with
surface or coated with black metal oxides.(nickel oxide, chromium oxide).
• Conduits are same material that of absorber.
• Tubes are of diameter 10-15mm , they are brazed , soldered or pressure bonded
with absorber plate.
• Headers are of 20-25mm diameter.
• Cover is low ferric oxide toughened glass.
• Glass glazing is 2-5mm thick, gap b/w absorber and cover is 15-30mm.
Saturday, April 16,
2016 6
8. The thermal performance of a collector can be calculated from a first-
law energy balance. according to the first law of thermodynamics, for
a simple flat-plate collector an instantaneous steady-state energy
balance is[1] :
Useful energy = energy absorbed – heat loss to
gain (Qu) by the collector surroundings
9. • Absorbed energy = AC FR S
• Lost energy = AC FR UL (Ti-Ta)
where ;
AC = Collector area, m2
FR = Heat removal factor, unitless
S = Absorbed solar radiation, J/m2
UL = Heat transfer loss coefficient, J/m2 °C
Ti = The mean absorber plate temperature, °C
Ta = The ambient temperature, °C.
Saturday, April 16, 2016 9
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12. THREE LOSS COEFFCIENT
• Top loss coefficient( Covers, upper parts)
• Side loss coefficient( through sides)
• Bottom loss coefficient.(bottom such as insulation)
• TOP HEAT LOSS ACCOUNTS MORETHAN 70% OFTOTAL
LOSS AND IS CONTAINS ABSORPTIVITY, EMISSIVITY,
MATERIALVARIANCE, WIND SPEED ETC .
Saturday, April 16, 2016 12
13. TOP LOSS COEFFCIENT
Saturday, April 16, 2016 13
As the wind loss coefficient increases,
more amount of heat is dissipated to
atmosphere and consequently lower
efficiency can be expected.
16. PARAMETERS EFFECTING PERFORMANCE
Heat Transfer System
• Heat from the absorber plate is removed from fluid.
• Usually cool fluid enters and gets heated up and is passed.
• Usually thermosiphon principle is used, otherwise external
pumping may be adopted.
• It also depends on type of fluid used.
• Some fluids used are: Ethanol, Methanol, water, Acetone etc.
• Medium inside the collector.
• Usually air, sometime inert gases are filled.
Saturday, April 16, 2016 16
17. Selective Surfaces
• Absorber plate surfaces which provides high absorptivity for
incoming solar radiation and low emissivity for outgoing solar
radiation is termed as selective surface.
• Solar radiation lies short wavelength band up to 4micro meter,
while the absorber plate the long wave radiation of wavelength
8.3 micro meter.
• No natural surface has this selective surface radiation
characteristics.
• A successful selective surface can be developed by a thick
metallic oxide base on a metal base.
• A good selective surface will have 0.95 absorptivity , 0.1
emissivity.
Saturday, April 16, 2016 17
19. Number of covers
• To minimize the convection and radiation loss the solar
collector is covered with a transparent glass sheet over a
absorber plate.
• Solar radiation incident on glass passes through it and glass
cover.
• Thus the glass sheet cover reduces the heat loss coefficient up
to 10W/m^2 K.
• It is seen that with two glass covers the heat loss coefficient
was still reduced to 4W/m^2 K.
Saturday, April 16, 2016 19
21. Transmissivity Absorptivity Product
Saturday, April 16, 2016 21
S is absorbed radiation and it is equal to:
are the view factors from the
collector to the sky and from the collector to the ground, respectively.
The subscripts b,d, and g represent beam, diffuse, and ground ,
respectively. is transmittance and absorptance product.Rb is
the ratio of beam radiation on the tilted surface to that on a horizantal
surface at any time.
Equation 4.2 Absorbed solar radiation[6].
)2/cos1(),2/cos1(
22. Spacing
• Spacing between the absorber plate and the cover or
between two covers also influence the performance.
• The operating performance varies with space as well as tilt
and service conditions.
• There is no exact way to express spacing.
• The experiments have revealed that 4cm to 8cm will give
good results.
• Large spacing reduces collector area requirements.
Saturday, April 16, 2016 22
23. Glazing
• Low iron clear glass of 5 mm thickness is used as glazing panel.
• The experiment was conduction to check
Optimum glazing covers and space.
• 5 mm , 10 mm, 15mm space with 1, 2, 3
Glazing covers
Saturday, April 16, 2016 23
29. Geometric Parameters
• Spacing: Lower the gas conductivity, the smaller the volume
required for maximum efficiency.
• Tube thickness: Improvement in efficiency when using 1.0 mm
thick tubes instead of 0.5 mm because of the changed
Reynolds number.
• Helical pipe collector gives higher temperature in hot water
tank.
Saturday, April 16, 2016 29
30. Materials Used for construction
• Absorber plate material : Low cost galvanized iron as absorber
material can give efficiency comparable to copper.
• Tube and header material : Low cost coated stainless steel tube and
aluminium tube gives same performance as copper.
• Absorber coating material : Higher outlet temperature and higher
efficiency for black chrome followed by the matt black and sol
chrome.
• Working fluid : Acetone gives higher efficiency than methanol and
ethanol. Water gives higher efficiency than methanol.
Saturday, April 16, 2016 30
31. Other things
• Use of PCM :The temperature of water in PCM filled FPC is much
higher.
• Porous aluminium absorbers : Maximum efficiency for the more
porous and thicker absorber at the highest air mass flow rate, but
at very low air flow rates the absorber porosity shows a reversed
effect.
Saturday, April 16, 2016 31
32. CONCLUSION
• MAJOR LOSSES OCCUR INTOP LOSS.
• LOT OF SCOPE FOR REDUCING ABSORBER AREA.
• OPTIMUM GLAZINGWILL REDUCE LOSSES.
• BEST INSULATION MATERIAL WILL REDUCE LOSSES.
• SELECTION OF RIGHT MATERIAL WILL GIVE US DRASTIC CHANGE IN
EFFICIENCY.
• Solar energy is free if we do not include the initial cost for
installation and the maintenance.
Saturday, April 16, 2016 32
33. • PERFORMANCE STUDIES OFTUBULAR FLAT PLATE COLLECTORS"
Md. SakhawatHusain International Centre forTheoretical Physics,Trieste, Italy.
INTERNATIONALCENTRE FORTHEORETICAL PHYSICS
• EVALUATION OF HEAT LOSS COEFFICIENTS IN SOLAR FLAT PLATE COLLECTORS
Y. Raja Sekhar1, K.V. Sharma1 and M. Basaveswara Rao2
1Centre for Energy Studies, J. N.T. U. H. College of Engineering, Kukatpally, Hyderabad, India
2Department of Mechanical Engineering, S.V. I.T, Secunderabad, India
• RENEWABLE ENERGY SOURCES AND EMERGINGTECHNOLOGIES
By D.P. KOTHARI, K. C. SINGAL, RAKESH RANJAN
• Recent investigations in solar flat plate collectors P A Kulkarni1, S P Sabnis2, R Sarangi3
Mechanical, DBIT, Mumbai, India
REFERENCE
Saturday, April 16, 2016 33