8.0 Thermal Energy Systems
Crude oil, $74.66, 2/1/10
Wholesale RBOB Gasoline, $1.94
Frank R. Leslie,
B. S. E. E., M. S. Space Technology, LS IEEE
2/4/2010, Rev. 2.0.1
fleslie @fit.edu; (321) 674-7377
www.fit.edu/~fleslie
In Other News . . .
 High Speed Trains (HST) are underfunded and state taxpayers may
have to pick up the difference
 College/university “green campus groups” active




Bemidji State: “One of our signature themes here at Bemidji
State University is environmental stewardship,” said Anna
Carlson, an adjunct professor of environmental studies at BSU.
At the forum, Carlson spoke about her CERT-funded greenhouse
gas inventory project. She calculated BSU’s greenhouse gas
emissions for the past 10 years using Clean Air-Cool Planet’s
online calculator. http://www.cleanair-coolplanet.org/toolkit/inv-calculator.php
Reactivate Florida Tech’s Green Campus Group?
 Compute the campus GHG emissions?
Form an energy club?
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7 Overview of Thermal Energy Systems
 Thermal energy is used directly as heat rather than
being converted to electricity
 Of course, a steam turbine might then make
electricity
 This energy is available from combustion, geothermal
sources, or solar radiation
 Here we consider the temperatures of the energy,
methods of collection, transfers of energy, special uses
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8.0 About This Presentation
 8.1 Laws of Thermodynamics
 8.2 Solar Hot Water Heaters
 8.3 Solar Stoves and Ovens
 8.4 Air Conditioning
 8.5 Boiler Systems




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8.6 Turbines
8.7 Thermoelectric Conversion
8.8 Shell Oil Reminder
8 Conclusion
8.1 Thermodynamics --- Classical, That is
 First Law of Conservation: Conservation of matter and
energy
 Energy may be transformed but is conserved
(ignores nuclear energy to mass )
 Second Law of Entropy: All matter tends towards
randomness, disorder and minimum energy
 Work must be done to make more order
(just look at my desk!)
 Everything falls apart or decays eventually
 Third Law: The entropy of a hypothetical pure crystal at
absolute zero temperature is zero
 The molecules are stationary; no energy left in them
060130
8.1.1 Heat Sources
 Combustion
 Coal, oil, and natural gas (NG) --- the fossil fuels
 Biofuel (wood, grasses, beans, corn, etc.)
 Solar radiation absorption by solar collectors
 Temperature difference: OTEC (Ocean Thermal Energy
Conversion) surface vs. deep ocean temperatures
 Radioisotope thermopiles (thermoelectric; Cassini or
New Horizons spacecraft; deep ocean transponders)
 Chemical exothermic reactions (give off heat; MREs)
 Hydrogen production by photodissociation of water or
extracted from algae
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8.1.a The Carnot Cycle
 The Carnot Cycle is a theoretical engine
operation that demonstrates the
maximum efficiency possible (can’t build
it!)
 Using Kelvin absolute temperatures, the
efficiency is the difference of the highest
input temperature minus the lower
exhaust temperature, all divided by the
high temperature
 A perfect engine could work with
equal input and exhaust
temperatures; no losses
 Real engines cannot exceed the
equivalent Carnot efficiency
Heat loss = QC/QH
QC/QH = TC/TH
Efficiency = 1 – loss
= 1 – (TC/TH )
= (TH-TC)/TH
So, for TH = 825K
& TC = 300K,
Carnot Efficiency =
= 1- TC/TH
= 1- 300K/825K
= 0.64 or 64%
Kelvin = [(°F-32) / (1.8)] + 273
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8.1.2 Degrees of Thermal “Quality”; Types of Use
 Low temperature quality
 ~70°F to ~220°F
 Example: House heating, hot water heating
 Medium temperature quality
 ~220°F to ~500°F
 Example: Industrial processing, cooking soup
 High temperature quality
 ~500°F to ~10,000°F
 Example: Materials testing, utility power like “Solar
One” at Barstow CA
 The Sandia power tower tested missile nose cones;
like Corel™ dinnerware
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8.1.2.1 SEGS (Solar Electric Generating Systems) at Kramer
Junction CA --- Parabolic Reflectors
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http://www.eia.doe.gov/kids/energyfacts/sources/renewable/solar.html
8.1.2.2 Solar One Daggett (hot oil fluid) near Barstow CA
030127
http://geoimages.berkeley.edu/GeoImages/BainCalif/CAL400/SOLARONE.HTML
8.1.3 French Solar Furnace Laboratory
Odellio, France capable of
33,000 °Celsius
http://geoimages.berkeley.edu/GeoImages/BainCalif/CAL400/SOLARONE.HTML
060130
8.1.3.1 Solar Two Power Tower Diagram
Ref.: http://www.boeing.com/assocproducts/energy/articles/Power_experience.pdf
050119
8.1.3.2 Cycles of Heat Engines
 Carnot Engine – a theoretical or ideal maximum
efficiency
engine where η = (1-Tc/Th)*100%
 Otto – the conventional 4-stroke automobile engine
 Diesel – fuel is injected into the hot compressed air and
bursts into flame, expanding and driving the piston
down
 Sterling and Ericsson Cycle use external combustion or
heat --- Sterling engine can run on a coffee cup heat
 Brayton Cycle for turbines: separate equipment for
compression, combustion, and expansion
 Rankine – a turbine cycle using reheat of the steam
after the first or high pressure stage
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8.1.3.2.1 Coffee Cup Sterling Engine
jlnlabs.ifrance.com/jlnlabs/images/stirlvid1.jpg
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8.1.3.3 Rankine Engines
Ref.: http://engphys.mcmaster.ca/~garlandw/ep716p1/chap4.pdf
030124
8.2 Hot Water Solar Collectors
 Batch tank
 A large water tank is directly heated by the sun
 Incoming cold water is warmed as the warmer water
leaves the tank for use
 Open Cycle (Florida type)
 The water is recirculated from a rooftop collector to a
heavily insulated hot water heater
 The electrical thermostat may be set at 120°F or
lower and rarely heats the water except on cloudy
days; electrical timer on after sunset (just in case)
 Closed Cycle (for freezing areas)
 A heat exchanger is placed between a circulating loop
containing freezeproof liquid and the drinking water
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8.2.1 A simple batch tank water heater
www.metaefficient.com
Water thermosyphons from the panel to the tank
Ref.: www.solarns.ca/spatial3.jpg
060130
8.3 Solar Stoves/Ovens
 Frenchman Muxiao designed a parabolic solar stove in 1860
 Cooking ovens collect the sun’s rays and absorb them in a black
colored interior, producing ~180°F
 Auxiliary reflective panels around the opening increase the
absorption further and the oven may reach 300°F
 Much larger units can be used as drying kilns
www.deathvalleypizza.com/
SCIPlanz.html
http://www.spw.org/spwzimbabweenvironmentprogrammes.htm
030124
8.3.1 Simple but Efficient “Third World” Cook Stoves
 A relatively simple clayfired pot can serve as a
stove to replace wood
campfires
 Wood is burned by
pushing it through the
hole in the side
 Efficiency is improved by
directing the heat to the
cooking pot
 A form is used so many
of these can be made at
once
site:www.bramptontanzania.com clay stove
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8.3.2 A Large Solar Tracker Oven at Solar Fiesta 2003
 This tracker-oven
was used to bake
three trays of
chocolate-chip
cookie at a time
 This really made
an impression on
the crowds (and
me! Yum!)
 Solar Fiesta is
held at
Albuquerque NM
at the Indian
Pueblo Center
070129
8.4.1 Air-to-Air Conditioning
 Basic operation
 The working fluid (refrigerant) is compressed, heating it (tire
pump gets hot as you pump)
 The fluid passes through a condensor and rejects heat to the
surrounding air or liquid
 It then passes through an expansion valve and cools, entering
the evaporator to absorb heat from the air stream
 Temperature differential
 The greater the temperature difference at the condenser, the
greater the efficiency of heat transfer
 Reverse cycle or heat pump
 If the piping is interchanged by a solenoid valve, the fluid can
absorb it from outside and expel heat in the building
 Reverse cycle systems have an Energy Efficiency Rating of six or
higher; resistance heating is only 1.0 (100% efficiency)
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8.4.1.1 Heat Pump Efficiencies
The current national efficiency standard for new heat pumps
requires heat pumps to meet a minimum of 13 SEER and 7.7
HSPF --- ACEEE
Heating Season Performance Factor (HSPF)
http://www.fsec.ucf.edu/bldg/pubs/pf362/ for a heat pump
report
www.wintonsac.com
060130
8.4.2 Water-to-Air Conditioning
 Heat exchanger
 Rather than conducting/rejecting heat directly into the air,
ground water is passed through a heat exchanger to absorb the
heat from the compressed refrigerant
 The hot and cold fluids must flow in opposite directions in the
exchanger for maximum heat transfer
 Corrosion
 If the ground water corrodes the exchanger, replacement costs
quickly make this approach infeasible and costly
 Water spray evaporators
 A few years ago, mail-order sales of a cheap water spray kit
with a solenoid valve were popular
 Water was directly sprayed on the condenser fins when the
compressor was running; cooled great and corroded away the
fins; see corrosion above
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8.5 Boiler Systems
 Superheat tubes carry
steam to increase its
temperature and energy
http://www.affordable-energy.org/
050119
http://www.lanl.gov/projects/cctc/factsheets/eerco/images/eerco_schematic_small.jpg
8.5.1.1 Engines
 Early Cooper engine weighs 130 tons
 Stephenson County Antique Engine Club, Freeport, IL,
USA.
http://www.steamengine.com.au/steam/engines/cooper/index.html
The Florida Flywheelers Club
near Ft. Meade (7000 Avon Park
Cutoff Rd) has three shows a
year; ~2/21-2/24/2010 is one
http://www.ytmag.com/cgibin/showgd.cgi
http://www.floridaflywheelers.org/
8.5.1.1.1 Engines
 The Florida Flywheelers Club near Ft. Meade (7000 Avon Park Cutoff Rd)
has three shows a year; 2/25-2/28/2009 is one
 http://www.ytmag.com/cgi-bin/showgd.cgi
 http://www.floridaflywheelers.org/
http://www.steamengine.com.au/steam/engines/cooper/index.html
8.5.1.2 Other Steam Uses
 Indiana University
plays this steam
calliope at various
events!
 Shouldn’t Florida
Tech have one,
too? Or maybe a
bandorgan to be
different
 This is direct from
steam to sound
 The range is
typically about
three miles on a
quiet day
 The original
“Boom Car”
caliope8[1].mp3
080128
8.5.2 Pressurized Fluidized Bed Combustion
TVA
050119
8.5.3 Heat Recovery Steam Generators (HRSG)
 Hot turbine exhaust gases
pass through the HRSG
where water or steam is
heated.
 Steam heated above boiling
is termed “superheated”
and contains more energy
 Acts like gas instead of
vapor above critical point
 This model contains several
sections operating at
various temperatures and
flow rates
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Ref. Babcock-Hitachi HRSG
http://www.bhk.co.jp/english/product/prd_main.
htm
8.5.4 Flue Gas Scrubbers (FGS)
 This is really an
anti-pollution
control, but it’s
so large that it
should be seen
to be
appreciated
 The gas is
sprayed with
limestone slurry
to remove
~90% of the
sulfur dioxide &
HCl
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http://www.tri-mer.com/RGBS/vertical_tower_packed_bed_scrubbers.jpg
8.6.1 Conventional Steam Turbines
 These turbines contain
many blades having a
radius inversely
proportional to the
pressure
 As the pressure falls, the
radius must increase to
get the same torque per
section
 Multiple sections are used
to allow steam at different
temperatures and
pressures to all contribute
to turning the shaft
050119
8.6.1 Turbine Types
 Types:
 Conventional steam boiler turbines
 Aeroderivative (designed from aircraft engines)
 Runs on natural gas, kerosene, or oil
 Microturbines (for stand-alone power generation)
 Runs on natural gas
 Gives off heat for building
 These may be the basis of a distributed power
network
 FSEC has installed one at Cocoa FL for evaluation

Now removed, I believe
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8.6.2 Aeroderivative Turbines
 Jet engine designs modified to drive a pump shaft were
developed and used for the Alyeska Pipeline from
Prudhoe Bay to Valdez, Alaska (3 on line and 1 spare)
 Later design variants were produced to turn generators
(GE shown below)
http://www.undergroundinfo.com/PGJ/pgj_archive/Oct2000/oct-8.pdf
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8.6.3.1 Combined Heat and Power (CHP)
 This Hitachi Waste Heat Recovery Boiler has two
separate loops for generating steam and reheating
steam
 The steam may also be used for industrial processes
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8.6.3.2 Combined Heat, Power, and Chemicals

080128
Syngas conversion can produce chemicals and other fuels. Hydrogen production is also possible.
8.6.3.2 Cogeneration: Steam & Hot Water Distribution
 Cogeneration systems are designed to wring more
energy from the fuel source
 The Carnot principle limits the work produced by an
engine, but the rejected waste heat may be used
elsewhere in a second cycle
 Water jackets or additional piping can capture this heat
for other uses
060127
8.6.4 Microturbines
 Microturbines (Capstone) have efficiencies of ~80%
 Heated water can power an absorption chiller
 Merritt Square Mall originally had a combined heat and
power unit (~1966; since removed)
 FSEC (Florida Solar Energy Center) is installing/has
installed a microturbine
http://www.microturbine.com/pdfs/Harbec%208.5x11.pdf
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8.7 Thermoelectric Conversion
 Heat is converted to electricity by the Seebeck Effect
www.profisica.cl
 Electricity can be converted to heat by resistance
 Electricity can be converted to cooling by the Peltier Effect
http://www.chipcenter.com/circuitcellar/december99/cimages1299/c129r22g10.gif
080123
http://www.thermotek.co.kr/technology/img/seebeck.gif
8.7.1 Conventional Thermopiles
 Thermopiles are made of dissimilar metals and generate
low voltage, high-current, direct current
 Voltage step-up (boost) convertors produce a more
usable voltage at a lesser current
Warm up your
holidays without
wasting energy. Our
Woodstove Ecofan
increases your
stove's efficiency
without drawing any
electricity. The
hotter your stove
gets, the faster the
fan blades twirl to
provide ultimate
comfort on chilly
days.
030124
http://www.realgoods.com/
8.7.2 Radioisotope Thermal Generators
(RTG)
Left: Extracting nuclear fuel from
its transport container for
insertion into the Radioisotope
Thermal Generator (RTG). The
RTG is at the astronaut's foot.
http://www.lpi.usra.edu/expm
oon/Apollo16/A16_science.ht
ml
 RTGs (like SNAP-27) create electricity from the heat of
radioactive decay of plutonium 238, having a half-life of
87 years
 A thermopile converts heat to electricity with dissimilar
metals or semiconductors
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8.7.3 Magnetohydrodynamics
http://hyperphysics.phy-astr.gsu.edu/hbase/magnetic/imgmag/mhd.gif
 A conductive plasma of hot gas is sent through a
magnetic field
 The moving plasma acts like a moving wire, and
electricity can be generated across plates on either side
of the stream
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8.8 A Shell Oil reminder
http://www.starrotor.com
030128
8 Conclusion
 Thermal energy conversion remains the predominant
use of fuel
 Since the fuels are still perceived as cheap, there isn’t
much public clamor to change to renewables
 Pollution effects are diffuse and overlooked by most
people
 As the price of conventional fuels increase and
renewables decrease, a shift will occur
 There must be a long period of overlap of the two
technologies to permit development of renewable
resources before conventional fuels become difficult to
obtain at a reasonable price
050201
Olin Engineering Complex 4.7 kW Solar PV Roof Array
Questions?
080116
References: Books
 Brower, Michael. Cool Energy. Cambridge MA: The MIT Press, 1992. 0-262-02349-0,
TJ807.9.U6B76, 333.79’4’0973.
 Duffie, John and William A. Beckman. Solar Engineering of Thermal Processes. NY:
John Wiley & Sons, Inc., 920 pp., 1991
 Patel, Mukund R. Wind and Solar Power Systems. Boca Raton: CRC Press, 1999, 351
pp. ISBN 0-8493-1605-7, TK1541.P38 1999, 621.31’2136
 Sørensen, Bent. Renewable Energy, Second Edition. San Diego: Academic Press,
2000, 911 pp. ISBN 0-12-656152-4.
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References: Websites, etc.
http://www.alyeska-pipe.com/PipelineFacts/pipelineconstruction.html
http://www.rustyiron.com/engines/stable/ericsson.html hobbyist site
http://www.energy.rochester.edu/us/comdhlst.htm cogeneration
http://www.realgoods.com/ renewable energy consumer products
http://www.constellation.com/images/generation/plant_oleander.jpg Merchant Plant
site:www.bramptontanzania.com clay stove for Africa to replace wood campfires
http://www.tri-mer.com/RGBS/vertical_tower_packed_bed_scrubbers.jpg FGS
http://hyperphysics.phy-astr.gsu.edu/hbase/magnetic/imgmag/mhd.gif magnetohydrodynamics
http://www.starrotor.com/indexflash.htm A Brayton cycle engine animated GIF
http://images.google.com/imgres?imgurl=http://www.sheclabs.com/SolarConcentrator/images/trailer_s
mall.jpg&imgrefurl=http://www.sheclabs.com/SolarConcentrator/SolarConcentrator.htm&h=284&w=21
3&sz=71&tbnid=FPnEjeS6K4oJ:&tbnh=109&tbnw=82&start=6&prev=/images%3Fq%3Dsolar%2Bcon
centrator%26hl%3Den%26lr%3D%26safe%3Dactive%26rls%3DGGLD,GGLD:2004-07,GGLD:en
http://www.photobiology.com/photoiupac2000/bircan/Index.htm
http://www.aceee.org/consumerguide/hp.pdf
http://www.alyeska-pipe.com/default.asp
_____________________________________________________________
mailto:energyresources@egroups.com
www.dieoff.org. Site devoted to the decline of energy and effects upon population
www.ferc.gov/ Federal Energy Regulatory Commission
www.google.com/search?q=%22renewable+energy+course%22
solstice.crest.org/
dataweb.usbr.gov/html/powerplant_selection.html
060127
Slide stockpile follows!
Older slides follow this one.
Look at these if you have
interest or time. It’s difficult
to decide what to leave out
of the lecture to save time!
8.6.2.1 Oleander Power Plant, Cocoa FL
 Owned by Southern Power Co.
 $206M, 680 MWe, selling contracts to Seminole Electric
Cooperative, Inc. and FPL
 4.2M lb pollutants per year
 Uses 73M gallons deionized water per year
 Water spray cools inlet air to get more power
 Burns NG at least 2/3 of the time; low sulfur #2 diesel
oil at other times (primarily for backup)
 Connected to the Florida Gas Transmission Line
 Close to natural gas pipeline
 Turbines produce power within 30 minutes of starting
060127
8.6.2.1.1 Plant is compactly placed
 Located
northeast of
I-95 and FL
520
 Four turbines
with space for
one more
 Oil is used as
backup to
natural gas
from a major
pipeline
050201
http://www.constellation.com/images/generation/plant_oleander.jpg
Had siting controversy with local public