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8.0 Thermal Energy Systems

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.

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8.0 Thermal Energy Systems

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  1. 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

  2. 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? 100204

  3. 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 100204

  4. 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 • 8.6 Turbines • 8.7 Thermoelectric Conversion • 8.8 Shell Oil Reminder • 8 Conclusion 060118

  5. 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

  6. 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 100203

  7. 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/QHQC/QH = TC/THEfficiency = 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 100203

  8. 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 090203

  9. 8.1.2.1 SEGS (Solar Electric Generating Systems) at Kramer Junction CA --- Parabolic Reflectors http://www.eia.doe.gov/kids/energyfacts/sources/renewable/solar.html 050201

  10. 8.1.2.2 Solar One Daggett (hot oil fluid) near Barstow CA http://geoimages.berkeley.edu/GeoImages/BainCalif/CAL400/SOLARONE.HTML 030127

  11. 8.1.3 French Solar Furnace Laboratory Odellio, France capable of 33,000 °Celsius http://geoimages.berkeley.edu/GeoImages/BainCalif/CAL400/SOLARONE.HTML 060130

  12. 8.1.3.1 Solar Two Power Tower Diagram Ref.: http://www.boeing.com/assocproducts/energy/articles/Power_experience.pdf 050119

  13. 8.1.3.2 Cycles of Heat Engines • Carnot Engine – a theoretical or ideal maximum efficiencyengine 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 080123

  14. 8.1.3.2.1 Coffee Cup Sterling Engine jlnlabs.ifrance.com/jlnlabs/images/stirlvid1.jpg 080128

  15. 8.1.3.3 Rankine Engines Ref.: http://engphys.mcmaster.ca/~garlandw/ep716p1/chap4.pdf 030124

  16. 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 050201

  17. Ref.: www.solarns.ca/spatial3.jpg 8.2.1 A simple batch tank water heater www.metaefficient.com Water thermosyphons from the panel to the tank 060130

  18. 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

  19. 8.3.1 Simple but Efficient “Third World” Cook Stoves • A relatively simple clay-fired 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 060127

  20. 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

  21. 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) 080128

  22. 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

  23. 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 100201

  24. 8.5 Boiler Systems • Superheat tubes carry steam to increase its temperature and energy http://www.affordable-energy.org/ http://www.lanl.gov/projects/cctc/factsheets/eerco/images/eerco_schematic_small.jpg 050119

  25. 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/cgi-bin/showgd.cgi http://www.floridaflywheelers.org/

  26. 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

  27. 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” 080128

  28. 8.5.2 Pressurized Fluidized Bed Combustion TVA 050119

  29. 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 Ref. Babcock-Hitachi HRSG http://www.bhk.co.jp/english/product/prd_main.htm 080123

  30. 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 050201 http://www.tri-mer.com/RGBS/vertical_tower_packed_bed_scrubbers.jpg

  31. 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

  32. 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 090203

  33. 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 080123

  34. 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 080123

  35. 8.6.3.2 Combined Heat, Power, and Chemicals • Syngas conversion can produce chemicals and other fuels. Hydrogen production is also possible. 080128

  36. 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

  37. 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 090203

  38. 8.7 Thermoelectric Conversion • Heat is converted to electricity by the Seebeck Effect • Electricity can be converted to heat by resistance • Electricity can be converted to cooling by the Peltier Effect www.profisica.cl http://www.thermotek.co.kr/technology/img/seebeck.gif http://www.chipcenter.com/circuitcellar/december99/cimages1299/c129r22g10.gif 080123

  39. 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. 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 030124 http://www.realgoods.com/

  40. 8.7.2 Radioisotope Thermal Generators (RTG) • 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 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/expmoon/Apollo16/A16_science.html 050201

  41. 8.7.3 Magnetohydrodynamics • 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 http://hyperphysics.phy-astr.gsu.edu/hbase/magnetic/imgmag/mhd.gif 090203

  42. 8.8 A Shell Oil reminder http://www.starrotor.com 030128

  43. 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

  44. Questions? Olin Engineering Complex 4.7 kW Solar PV Roof Array 080116

  45. 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. 050201

  46. 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_small.jpg&imgrefurl=http://www.sheclabs.com/SolarConcentrator/SolarConcentrator.htm&h=284&w=213&sz=71&tbnid=FPnEjeS6K4oJ:&tbnh=109&tbnw=82&start=6&prev=/images%3Fq%3Dsolar%2Bconcentrator%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

  47. 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!

  48. 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

  49. 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 http://www.constellation.com/images/generation/plant_oleander.jpg Had siting controversy with local public 050201

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