This document provides information on properly sizing and designing solar thermal systems. It discusses calculating hot water demand and heat requirements, sizing collectors and storage, choosing appropriate materials, commissioning expansion vessels, avoiding stagnation, and testing heat transfer fluids. Key steps include determining daily water usage, sizing collectors to meet 55-60% annual solar fraction based on location, using the correct piping and insulation materials, and preventing overheating with techniques like cooling vessels.
Solar power is the conversion of sunlight into electricity, through directly using photovoltaic (PV). Photovoltaic convert light into electric current using the photoelectric effect.
This new minute lecture gives an introduction to photovoltaic (PV) systems for residential use, providing an answer to following questions:
* How does a PV system work?
* What can be expected from a PV system?
* What types of systems are available?
* How is technology expected to evolve?
Solar power is the conversion of sunlight into electricity, through directly using photovoltaic (PV). Photovoltaic convert light into electric current using the photoelectric effect.
This new minute lecture gives an introduction to photovoltaic (PV) systems for residential use, providing an answer to following questions:
* How does a PV system work?
* What can be expected from a PV system?
* What types of systems are available?
* How is technology expected to evolve?
What is solar energy?
Types of solar energy
Solar thermal energy
Photovatic energy (PV)
How are solar panels made?
How does solar energy works?
Uses of solar energy
Strenghts of solar energy
Weakness of solar energy
Opportunites of solar energy
Threats of solar energy
An Overview of Photovoltaic Systems or PV Systems. This PPT outlines what a solar systems is and what it is consisted of. From solar panels to charge controller to deep cycle batteries to the inverter.
Solar Water Pump - a new Innovative ProjectANURAG BERA
This is our Project Work in our course "Application of Information Technology".Here we have discussed regarding Solar Water Pump implementation & it's utility in Modern Agricultural System
Basic introduction to solar PV System Presentation.
The need for renewable energy resources has never been bigger than today and so is a lot of research going to match this high energy demand. Solar PV Array technology is one such technique which can actually make the effective use of solar energy available to us.
What is solar energy?
Types of solar energy
Solar thermal energy
Photovatic energy (PV)
How are solar panels made?
How does solar energy works?
Uses of solar energy
Strenghts of solar energy
Weakness of solar energy
Opportunites of solar energy
Threats of solar energy
An Overview of Photovoltaic Systems or PV Systems. This PPT outlines what a solar systems is and what it is consisted of. From solar panels to charge controller to deep cycle batteries to the inverter.
Solar Water Pump - a new Innovative ProjectANURAG BERA
This is our Project Work in our course "Application of Information Technology".Here we have discussed regarding Solar Water Pump implementation & it's utility in Modern Agricultural System
Basic introduction to solar PV System Presentation.
The need for renewable energy resources has never been bigger than today and so is a lot of research going to match this high energy demand. Solar PV Array technology is one such technique which can actually make the effective use of solar energy available to us.
Solar thermal energy is used to heat water or other fluids, and can also power solar cooling systems. They differ from solar photovoltaic (PV) systems, which generate electricity rather than heat.
There are three main types of solar hot water panels: Evacuated tube, glazed flat panel, and unglazed flat panel. Each of these types of panels have different operating conditions where they have better efficiency than the others.
2
In this case we are based on glazed flat panels, which are better for domestic hot water heating, also they are recommended for moderate climates. Glazed flat-plate collectors are insulated, weatherproofed boxes that contain a dark absorber plate under one or more glass or plastic (polymer) covers (Anónimo, Solar Direct, s/f).
eme.pptMechanical engineering is the study of physical machines that may involVINODN33
Technically, mechanical engineering is the application of the principles and problem-solving techniques of engineering from design to manufacturing to the marketplace for any object. Mechanical engineers analyze their work using the principles of motion, energy, and force—ensuring that designs function safely, efficiently, and reliably, all at a competitive cost.
Mechanical engineers make a difference. That's because mechanical engineering careers center on creating technologies to meet human needs. Virtually every product or service in modern life has probably been touched in some way by a mechanical engineer to help humankind.
This includes solving today's problems and creating future solutions in health care, energy, transportation, world hunger, space exploration, climate change, and more.Being ingrained in many challenges and innovations across many fields means a mechanical engineering education is versatile. To meet this broad demand, mechanical engineers may design a component, a machine, a system, or a process. This ranges from the macro to the micro, from the largest systems like cars and satellites to the smallest components like sensors and switches. Anything that needs to be manufactured—indeed, anything with moving parts—needs the expertise of a mechanical engineer.
Module_2_Solar Collectors in environment.pptxRahulBadachi1
Nature paints a serene backdrop with lush greenery, towering trees, and a gentle stream under the warm embrace of the setting sun. The air is filled with the delicate scents of blooming flowers, creating a tranquil atmosphere. Birds add a musical touch, their chirps blending harmoniously with the rustling leaves and the soft babble of the brook.
Life thrives in this natural haven, as playful squirrels leave tiny footprints in the soft soil, and colorful butterflies gracefully flutter through the air. The environment resonates with the soothing sounds of insects, contributing to the lively symphony of nature. Each element, from the vibrant hues of the flora to the intricate movements of the fauna, collaborates to form a captivating ecosystem.
This idyllic setting invites observers to appreciate the delicate balance of life in nature. It serves as a sanctuary where the beauty of the environment lies in its simplicity, offering a peaceful retreat and a moment of connection with the wonders of the natural world.
Nature paints a serene backdrop with lush greenery, towering trees, and a gentle stream under the warm embrace of the setting sun. The air is filled with the delicate scents of blooming flowers, creating a tranquil atmosphere. Birds add a musical touch, their chirps blending harmoniously with the rustling leaves and the soft babble of the brook.
Life thrives in this natural haven, as playful squirrels leave tiny footprints in the soft soil, and colorful butterflies gracefully flutter through the air. The environment resonates with the soothing sounds of insects, contributing to the lively symphony of nature. Each element, from the vibrant hues of the flora to the intricate movements of the fauna, collaborates to form a captivating ecosystem.
This idyllic setting invites observers to appreciate the delicate balance of life in nature. It serves as a sanctuary where the beauty of the environment lies in its simplicity, offering a peaceful retreat and a moment of connection with the wonders of the natural world.
Nature paints a serene backdrop with lush greenery, towering trees, and a gentle stream under the warm embrace of the setting sun. The air is filled with the delicate scents of blooming flowers, creating a tranquil atmosphere. Birds add a musical touch, their chirps blending harmoniously with the rustling leaves and the soft babble of the brook.
Life thrives in this natural haven, as playful squirrels leave tiny footprints in the soft soil, and colorful butterflies gracefully flutter through the air. The environment resonates with the soothing sounds of insects, contributing to the lively symphony of nature. Each element, from the vibrant hues of the flora to the intricate movements of the fauna, collaborates to form a captivating ecosystem.
This idyllic setting invites observers to appreciate the delicate balance of life in nature. It serves as a sanctuary where the beauty of the environment lies in its simplicity, offering a peace
Module_2_Solar Collectors in environment management.pptxRahulBadachi1
Nature paints a serene backdrop with lush greenery, towering trees, and a gentle stream under the warm embrace of the setting sun. The air is filled with the delicate scents of blooming flowers, creating a tranquil atmosphere. Birds add a musical touch, their chirps blending harmoniously with the rustling leaves and the soft babble of the brook.
Life thrives in this natural haven, as playful squirrels leave tiny footprints in the soft soil, and colorful butterflies gracefully flutter through the air. The environment resonates with the soothing sounds of insects, contributing to the lively symphony of nature. Each element, from the vibrant hues of the flora to the intricate movements of the fauna, collaborates to form a captivating ecosystem.
This idyllic setting invites observers to appreciate the delicate balance of life in nature. It serves as a sanctuary where the beauty of the environment lies in its simplicity, offering a peaceful retreat and a moment of connection with the wonders of the natural world.
Nature paints a serene backdrop with lush greenery, towering trees, and a gentle stream under the warm embrace of the setting sun. The air is filled with the delicate scents of blooming flowers, creating a tranquil atmosphere. Birds add a musical touch, their chirps blending harmoniously with the rustling leaves and the soft babble of the brook.
Life thrives in this natural haven, as playful squirrels leave tiny footprints in the soft soil, and colorful butterflies gracefully flutter through the air. The environment resonates with the soothing sounds of insects, contributing to the lively symphony of nature. Each element, from the vibrant hues of the flora to the intricate movements of the fauna, collaborates to form a captivating ecosystem.
This idyllic setting invites observers to appreciate the delicate balance of life in nature. It serves as a sanctuary where the beauty of the environment lies in its simplicity, offering a peaceful retreat and a moment of connection with the wonders of the natural world.
Nature paints a serene backdrop with lush greenery, towering trees, and a gentle stream under the warm embrace of the setting sun. The air is filled with the delicate scents of blooming flowers, creating a tranquil atmosphere. Birds add a musical touch, their chirps blending harmoniously with the rustling leaves and the soft babble of the brook.
Life thrives in this natural haven, as playful squirrels leave tiny footprints in the soft soil, and colorful butterflies gracefully flutter through the air. The environment resonates with the soothing sounds of insects, contributing to the lively symphony of nature. Each element, from the vibrant hues of the flora to the intricate movements of the fauna, collaborates to form a captivating ecosystem.
This idyllic setting invites observers to appreciate the delicate balance of life in nature. It serves as a sanctuary where the beauty of the environment lies in its simplicity, offering a peace
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.
Final project report on grocery store management system..pdfKamal Acharya
In today’s fast-changing business environment, it’s extremely important to be able to respond to client needs in the most effective and timely manner. If your customers wish to see your business online and have instant access to your products or services.
Online Grocery Store is an e-commerce website, which retails various grocery products. This project allows viewing various products available enables registered users to purchase desired products instantly using Paytm, UPI payment processor (Instant Pay) and also can place order by using Cash on Delivery (Pay Later) option. This project provides an easy access to Administrators and Managers to view orders placed using Pay Later and Instant Pay options.
In order to develop an e-commerce website, a number of Technologies must be studied and understood. These include multi-tiered architecture, server and client-side scripting techniques, implementation technologies, programming language (such as PHP, HTML, CSS, JavaScript) and MySQL relational databases. This is a project with the objective to develop a basic website where a consumer is provided with a shopping cart website and also to know about the technologies used to develop such a website.
This document will discuss each of the underlying technologies to create and implement an e- commerce website.
NUMERICAL SIMULATIONS OF HEAT AND MASS TRANSFER IN CONDENSING HEAT EXCHANGERS...ssuser7dcef0
Power plants release a large amount of water vapor into the
atmosphere through the stack. The flue gas can be a potential
source for obtaining much needed cooling water for a power
plant. If a power plant could recover and reuse a portion of this
moisture, it could reduce its total cooling water intake
requirement. One of the most practical way to recover water
from flue gas is to use a condensing heat exchanger. The power
plant could also recover latent heat due to condensation as well
as sensible heat due to lowering the flue gas exit temperature.
Additionally, harmful acids released from the stack can be
reduced in a condensing heat exchanger by acid condensation. reduced in a condensing heat exchanger by acid condensation.
Condensation of vapors in flue gas is a complicated
phenomenon since heat and mass transfer of water vapor and
various acids simultaneously occur in the presence of noncondensable
gases such as nitrogen and oxygen. Design of a
condenser depends on the knowledge and understanding of the
heat and mass transfer processes. A computer program for
numerical simulations of water (H2O) and sulfuric acid (H2SO4)
condensation in a flue gas condensing heat exchanger was
developed using MATLAB. Governing equations based on
mass and energy balances for the system were derived to
predict variables such as flue gas exit temperature, cooling
water outlet temperature, mole fraction and condensation rates
of water and sulfuric acid vapors. The equations were solved
using an iterative solution technique with calculations of heat
and mass transfer coefficients and physical properties.
Cosmetic shop management system project report.pdfKamal Acharya
Buying new cosmetic products is difficult. It can even be scary for those who have sensitive skin and are prone to skin trouble. The information needed to alleviate this problem is on the back of each product, but it's thought to interpret those ingredient lists unless you have a background in chemistry.
Instead of buying and hoping for the best, we can use data science to help us predict which products may be good fits for us. It includes various function programs to do the above mentioned tasks.
Data file handling has been effectively used in the program.
The automated cosmetic shop management system should deal with the automation of general workflow and administration process of the shop. The main processes of the system focus on customer's request where the system is able to search the most appropriate products and deliver it to the customers. It should help the employees to quickly identify the list of cosmetic product that have reached the minimum quantity and also keep a track of expired date for each cosmetic product. It should help the employees to find the rack number in which the product is placed.It is also Faster and more efficient way.
NO1 Uk best vashikaran specialist in delhi vashikaran baba near me online vas...Amil Baba Dawood bangali
Contact with Dawood Bhai Just call on +92322-6382012 and we'll help you. We'll solve all your problems within 12 to 24 hours and with 101% guarantee and with astrology systematic. If you want to take any personal or professional advice then also you can call us on +92322-6382012 , ONLINE LOVE PROBLEM & Other all types of Daily Life Problem's.Then CALL or WHATSAPP us on +92322-6382012 and Get all these problems solutions here by Amil Baba DAWOOD BANGALI
#vashikaranspecialist #astrologer #palmistry #amliyaat #taweez #manpasandshadi #horoscope #spiritual #lovelife #lovespell #marriagespell#aamilbabainpakistan #amilbabainkarachi #powerfullblackmagicspell #kalajadumantarspecialist #realamilbaba #AmilbabainPakistan #astrologerincanada #astrologerindubai #lovespellsmaster #kalajaduspecialist #lovespellsthatwork #aamilbabainlahore#blackmagicformarriage #aamilbaba #kalajadu #kalailam #taweez #wazifaexpert #jadumantar #vashikaranspecialist #astrologer #palmistry #amliyaat #taweez #manpasandshadi #horoscope #spiritual #lovelife #lovespell #marriagespell#aamilbabainpakistan #amilbabainkarachi #powerfullblackmagicspell #kalajadumantarspecialist #realamilbaba #AmilbabainPakistan #astrologerincanada #astrologerindubai #lovespellsmaster #kalajaduspecialist #lovespellsthatwork #aamilbabainlahore #blackmagicforlove #blackmagicformarriage #aamilbaba #kalajadu #kalailam #taweez #wazifaexpert #jadumantar #vashikaranspecialist #astrologer #palmistry #amliyaat #taweez #manpasandshadi #horoscope #spiritual #lovelife #lovespell #marriagespell#aamilbabainpakistan #amilbabainkarachi #powerfullblackmagicspell #kalajadumantarspecialist #realamilbaba #AmilbabainPakistan #astrologerincanada #astrologerindubai #lovespellsmaster #kalajaduspecialist #lovespellsthatwork #aamilbabainlahore #Amilbabainuk #amilbabainspain #amilbabaindubai #Amilbabainnorway #amilbabainkrachi #amilbabainlahore #amilbabaingujranwalan #amilbabainislamabad
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.
Sachpazis:Terzaghi Bearing Capacity Estimation in simple terms with Calculati...Dr.Costas Sachpazis
Terzaghi's soil bearing capacity theory, developed by Karl Terzaghi, is a fundamental principle in geotechnical engineering used to determine the bearing capacity of shallow foundations. This theory provides a method to calculate the ultimate bearing capacity of soil, which is the maximum load per unit area that the soil can support without undergoing shear failure. The Calculation HTML Code included.
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.
An Approach to Detecting Writing Styles Based on Clustering Techniquesambekarshweta25
An Approach to Detecting Writing Styles Based on Clustering Techniques
Authors:
-Devkinandan Jagtap
-Shweta Ambekar
-Harshit Singh
-Nakul Sharma (Assistant Professor)
Institution:
VIIT Pune, India
Abstract:
This paper proposes a system to differentiate between human-generated and AI-generated texts using stylometric analysis. The system analyzes text files and classifies writing styles by employing various clustering algorithms, such as k-means, k-means++, hierarchical, and DBSCAN. The effectiveness of these algorithms is measured using silhouette scores. The system successfully identifies distinct writing styles within documents, demonstrating its potential for plagiarism detection.
Introduction:
Stylometry, the study of linguistic and structural features in texts, is used for tasks like plagiarism detection, genre separation, and author verification. This paper leverages stylometric analysis to identify different writing styles and improve plagiarism detection methods.
Methodology:
The system includes data collection, preprocessing, feature extraction, dimensional reduction, machine learning models for clustering, and performance comparison using silhouette scores. Feature extraction focuses on lexical features, vocabulary richness, and readability scores. The study uses a small dataset of texts from various authors and employs algorithms like k-means, k-means++, hierarchical clustering, and DBSCAN for clustering.
Results:
Experiments show that the system effectively identifies writing styles, with silhouette scores indicating reasonable to strong clustering when k=2. As the number of clusters increases, the silhouette scores decrease, indicating a drop in accuracy. K-means and k-means++ perform similarly, while hierarchical clustering is less optimized.
Conclusion and Future Work:
The system works well for distinguishing writing styles with two clusters but becomes less accurate as the number of clusters increases. Future research could focus on adding more parameters and optimizing the methodology to improve accuracy with higher cluster values. This system can enhance existing plagiarism detection tools, especially in academic settings.
2. Solar radiation drives all natural cycles and processes
on earth such as rain, wind, photosynthesis, ocean
currents and several others that are important for life.
From the very beginning of life, the overall world
energy need has been based on solar energy. All
fossil fuels (oil, gas, coal) are a result of solar energy.
The energy from the sun acting on the earth’s
surface, over a 15 minute period, is more than the
earth’s total energy requirement for a year. The
amount of yearly global radiation on a horizontal
surface may reach over 2,200 kWh/m2 in sunny
regions. In Lebanon, the maximum values are1,100
kWh/m2 and are 943kWh/m2.
3. Global radiation comprises direct and diffuse
radiation. As sunlight passes through the
atmosphere, some of it is absorbed, reflected
and scattered by air molecules, clouds and dust
particles, this is known as diffuse radiation.
The portion of
radiation that
hits the earth’s
surface without
any change in
direction is
known as direct
radiation
4. The Azimuth angle is the angular distance
between true south and the point on the
horizon directly below the sun. The azimuth
angle for south in solar applications is
defined as β = 0°, west = 90°, east = -90°.
5. The collector plane ‘A’ should be orientated as
closely as possible to the south. Collectors can be
productive in installations with azimuth angles ‘α’
up to 45°east or west of south with little variation in
system performance, circa 1.5% reduction. Systems
that deviate more then 45° will require additional
collector area to compensate.
6.
7. As the angle of
incidence of the
sun varies during
the year (highest
during summer),
the maximum
radiation yield of
the collector can
only be achieved if
the collector
surface is inclined
at an angle to the
horizontal.
8.
9. Shading will reduce the overall performance of a solar system.
During the planning stage of a solar system, consideration
should be given to the location of the collectors with the aim of
minimizing the effects of shading from high buildings, trees,
etc. In addition, when dealing with larger systems with more
than one row of collectors, sufficient space between the
collector rows should be allowed for.
10. α = Roof pitch
β = Collector
inclination + roof
pitch
γ = Angle of sun
above the horizon
b = Height of solar
collector:
d1 = b x sin(β - α) / tan(γ
- α)
d = (b x cos(β - α)) + d1
h = √ b2 – d2
11. Stagnation occurs when the solar loop does not transfer the
energy from the collector during times when there is high solar
radiation. Stagnation causes the absorber to heat up to very high
temperatures.
The system should be designed so that the occurrence of
stagnation should be eliminated or minimized as much as
possible. Typically, stagnation occurs where the solar collector
has been over-sized or where the building has long periods of
no hot water demand.
It should be noted that irreparable damage will be caused to
systems that are exposed to long periods of stagnation. Later in
this guide we will explore ways of protecting the solar system
from stagnation, these include:
• Controllers with holiday functions
• How to size a solar system correctly
• Using a heat dump or radiator on the system
13. A) Solar glass
B) Cu or Al-absorber sheet
C) Powder-coated aluminum frame
D) Collector pipe
E) Mineral wool insulation
F) Meander tube
G) Higher selective absorber coating
H) Bottom plate made of aluminum
I) Secure glass fixing
J) Revolving groove for assembly
14. 2) Evacuated Tube Collectors
Vacuum tube collectors perform extremely well when compared to
unglazed and glazed collectors, particularly in Northern European
countries. Solar vacuum collectors are the premium product on
the market, acknowledged as the most efficient method of
generating solar hot water even in cold, wet and windy conditions.
This is due to the low thermal losses from the collector.
By creating a vacuum of 10-6 bar within the tube, thermal losses
caused by conduction and convection are eliminated, this enables
the collector to be very effective in utilizing low amounts of
radiation (diffused radiation).
The tube is made from glass with unique properties that gives it
good transmissibility with low reflection losses and good
durability.
High absorption of solar energy is achieved by using an absorber.
The main assembly parts of the absorber are the absorber plate
and the heat transfer tube. The absorber plate is coated with a
special high efficiency selective coating that ensures maximum
radiation absorption and minimum thermal radiation losses.
15. This collector is a direct flow type
collector. The heat medium to be
heated is passed down through the
collector tube within a coaxial heat
exchanger. This product can be
installed on a pitched or horizontal
surface, and the tube can be rotated
25° to compensate for installations
that deviate from south. As this
collector is a fully pumped unit there
is no minimum angle of inclination
for the collector.
collectors are available in 3 sizes:
10 Tube = 1.08m2 aperture area
20 Tube = 2.16m2 aperture area
30 Tube = 3.23m2 aperture area
Up to a maximum of 5 x 30 tubes
collectors can be joined together in
series with a flow rate of
15Ltrs/min.
16. All solar collector systems have the sun as a
common energy source. The performance
depends therefore on the conversion of the solar
radiation into useful thermal energy and to
transfer it to the hot water system.
The ability to convert solar energy into thermal
energy is expressed by the optical efficiency of
the system η0. It is accepted practice within the
European solar industry to quote efficiencies
based upon the aperture area of the collector and
the SEI (Harp) database utilizes the performance
figures based upon the aperture area.
17. When sizing a solar system for domestic hot
water, we typically will size the system to
achieve an annual solar fraction of between
55 – 60%.
A correctly sized domestic system would see
the following solar contribution over a year:
18. It should be noted that minimizing the risk of
stagnation must be considered when sizing a
solar system. The system must not be
oversized.
The following diagram
outlines the steps
involved in correctly
sizing a solar system:
19. (a) Determine the Daily Hot Water Demand
Ideally the hot water demand value should be provided through
proper metering, however,
where this is not possible, the daily demand should be estimated
using the following tables:
20.
21. Sizing a flat panel collector for a 4 person
domestic household From Fig 19, medium
demand = 40 Ltr/person/day
Total daily demand = 40 x 4 = 160 Ltr/day
22. (b) Calculate the Hot Water Heat Requirement
The amount of energy to heat the daily hot water
demand (QHW) is calculated using the formula:
Volume of Hot Water = From Fig 19
Cw = Specifi c heat capacity of water (1.16 Wh/kgK)
ΔT = Temperature difference between cold water
temperature and desired water temperature
Continuing example of 4 person domestic household:
Therefore the heat requirement = 9.28 kWh/day
23. (c) Calculate the Storage Volume
For domestic solar systems typically the storage volume of
the cylinder should be equal to 2 times the daily hot water
demand. To correctly size the storage volume the
following formula should be used:
Vcyl = Minimum volume of cylinder (Ltr)
Vn = DHW demand per person/day (Ltr)
P = Number of people
Th = Temperature of hot water at outlet (°C)
Tc = Temperature of cold water
Tdhw = Temperature of stored water
24. The cylinder size is rounded up to the nearest available size, in this
case = 250 Litres
(d) Sizing the Collector Area
To size the required collector area the following formula is used:
25.
26. AR (collector area) = 3.89m2 fl at panel
collector
Nearest size = 2 x 2m2 collectors = 4m2
27. The system efficiency is strongly dependent on the solar fraction of the
system. When there is a high solar fraction the system efficiency is lower.
High solar fractions result in a higher return temperature to the solar
collector, the effect of this is that less solar irradiation can be absorbed by
the collector, hence reducing the system efficiency. In undersized systems
with small collector areas, the solar fraction is low but the system efficiency is
high. In oversized systems with large collector areas the sola fraction is high
but the system efficiency is low.
28. To simplify the selection of collector area, the following
graph have been created to quickly determine the
correct collector size for UK and Ireland. If the same
daily DHW demand was required using an evacuated
tube collector, from below we would see a collector
area of 3m2 for a solar fraction of 60%.
29. Suitable Materials
The following piping materials are suitable
for use in a solar system:
• Black steel pipe (a.k.a. gun barrel)
• Copper tubing
• Stainless steel tubing
30. The insulation has to be UV stable where
exposed to the sunlight and has to be resistant
to high temperatures in excess of 170°C. T
prevent high heat losses through the pipe work it
is recommended to use insulation with a
minimum thickness equal to half the pipe
diameter and an U value in [W/(mK)] of U ≤ 0.035
[W/(mK)].
It should be noted that REIA recommend an
insulation thickness equal to 100% of the internal
diameter.
31. We do not recommend the use of the
following material to be used in solar
systems:
• Plastic pipes (PEX)
• Multi-layer aluminium / plastic pipes (ALU-
PEX)
• Galvanized metal pipes
32. • Compression fittings
• Press fittings (with gasket rated for
temperatures above 150°C)
• Brazed fittings
• Fittings supplied with solar stainless steel
tubing, i.e. Waterway, Aeroline etc.
Note: The use of solder ring fittings on
copper pipework is not recommended
33. For pipe sizing we recommend a minimum
flow rate of 60 Liters/hr/m2 is used.
i.e. a DF100-30 tube system = 60 Liters/hr x
3m2 = flow rate = 180 Liters/hour.
In order to minimize the pressure drop
through the solar pipe work, we recommend
that the flow velocity through the solar pip
work should not exceed 1 m/s.
Ideally flow velocities between 0.4 and 1m/s
should be used, resulting in a pressure drop of
between 1 and 2.5 mbar/m pipe length.
34.
35. Flow for each solar collector and make the
sum of the total flow in L/s, note that the
flow will be very small don’t be in a panic…
Head is approached in static, pipe length,
fittings, drop in solar collector.
36. The function of an expansion vessel in a solar system
is to absorb the volume increase in the solar liquid
when it is heated and return it back to the system
when it cools down.
Care should be taken to ensure the expansion vessel
is sufficiently large enough to accommodate the
content of the collector when steam forms
(stagnation), this is to ensure that no heat transfer
medium can escape from the safety valve.
To size the expansion vessel we use the following
equation:
37.
38.
39. Commissioning Expansion Vessels:
Before filling the system, the gas side of the
expansion vessel must be set 0.3 bar lower
then the cold fill pressure of the solar system.
The cold fill pressure should be
approximately equal (not less than) to 1 bar
+ 0.1 bar/m static height. The safety seal
(volume of fluid in the expansion vessel)
should be 3 liters.
40. The VDI 6002 directive recommends a
cooling vessel “...when the contents of the
piping between the collectors’ field and the
expansion vessel is lower than 50% of the
reception capacity of the expansion vessel”.
The cooling vessel is also known as a
'temperature reducing vessel’, ‘stagnation
vessel’ or a ‘stratification vessel’.
41. A long period of high temperature fluid
in the expansion vessel has the effect
of shortening its useful life – ultimately
causing premature failure of the
diaphragm. To assist with the cooling
function of this vessel, the pipe work
from the pump station to the cooling
vessel and to the expansion vessel
must not be insulated.
There are no regulations regarding the
sizing of cooling vessels, however we
recommend the following method is
used.
The volume of the cooling vessel =
VCV = (0.5 x VEVS) – VS
Where
Vcv = Volume of cooling vessel
VEVS = Usable expandable volume
VSL = Volume of simple length of
pipework (distance from vessel to solar
collector)
42. As mentioned previously the occurrence of
stagnation in a solar system should be avoided.
Continuous temperatures in excess of 170°C will
cause the degrading of the Tyfocor solar solution
and degrade its inhibitor properties, this is
evident by the solution turning a brown color
The continuous high temperatures will also cause
damage to the collectors, pump station and
expansion vessels on the system
43. The solution on the right is the delivered state of the Tyfocor
solution, the beaker on the left contains a solution that has been in
stagnation for long periods above 170°C. We recommend that the
solution is tested every year and, based on the results of this test,
replaced as required. The solution should be tested using a refract
meter and ph test paper. This kit is available from our sales office.
Stagnation in a solar system can be caused by a number of reasons
such as:
1- Oversized systems – correct sizing methods have been
addressed
in previous chapters
2- Undersized expansion vessel – correct sizing methods have
been
addressed in previous chapters
3- Poor set up of the system – it is essential that all solar systems
are installed and
commissioned by fully trained and technically competent installers
who fully
understand the requirements of a high performance solar thermal
system
4- Air locks or leaks in the system