ELTR 1223 Survey of Renewable Energy Technology Unit 7 Overview of Solar Thermal Applications REEC 120 Sustainability and Renewable Energy Source:
Use Policy This material was developed by Timothy J. Wilhelm, P.E., Kankakee Community College, with funding from the National Science Foundation as part of ATE Grant No. 0802786. Additional changes were incorporated for REED 120 with funding from the Trade Adjustment Assistance Community College and Career Training (TAACCCT) SGA/DFA PY 10-03 All materials in this presentation are designed and intended for educational use, only. They may not be used for any publication or commercial purposes. Source:
Author, Editors/Reviewers Author: Timothy J. Wilhelm, P.E., Kankakee Community College Editors/Modifier: Chris Miller Heartland Community College Source:
Objectives Students will be able to describe, in very simple terms, black body absorption and radiation and their relationship to solar thermal applications. Students will be able to list the basic residential applications for solar thermal technology. Source:
Objectives Students will be able to discuss the basic requirements for passive solar architectural design. Students will be able to discuss and describe how active solar thermal technology works. Source:
Thermal Applications = Using Heat Typical Thermal Applications in Daily Human Living Residential Dwelling Applications: Space Heating Water Heating Cooking
Contemporary Thermal Sources The Heat Energy Necessary for Space Heating, Water Heating, and Cooking is typically Converted from: Electricity Natural Gas LPG Fuel Oil Coal Wood Other Combustible Fuels
Challenges Regarding our Conventional Sources of Thermal Energy Limited, Finite Supply All (except nuclear-fission sourced electricity) pump CO 2 back into the atmosphere All result in one or more additional, environmental pollutants The cost of all is continually increasing Most are not locally available and must be transported in
Moving Heat Energy to Where We Need it Heat is directed and moved via IR Radiation Conduction Convection
Conduction, and Radiation
Convection Source: http://cobblearning.net/rlimpert/files/2010/02/a3a421b29aedfa72.jpg
Conduction, Convection, and Radiation Source: http://cobblearning.net/rlimpert/files/2010/02/a3a421b29aedfa72.jpg
The Sun as a Source of Thermal Energy Black Body radiation and absorption! We see only reflected light When we see white light, the white surface is reflecting all frequencies of visible light When we see red light, the red surface is only reflecting the red frequency of visible light, and is absorbing all the other frequencies of visible light When a surface appears black it is absorbing all the frequencies of visible light and reflecting none
Black Body Radiation and Absorption Black Bodies absorb ALL frequencies At temps below 200 o C, Black Bodies (all bodies) radiate InfraRed frequencies InfraRed radiation is HEAT! Source: http://www.popsci.com/files/imagecache/article_image_large/files/articles/colorfire_485.jpg
Solar Thermal Technologies The basic ideas behind solar thermal energy are: Convert solar radiation into heat energy via Black Body absorption Trap the captured heat energy Limit IR radiation losses Limit Convective losses Limit Conductive losses Direct the captured heat energy into the desired zone or material via IR radiation, and/or convection, and/or conduction
Solar Thermal Technologies Solar Space Heating vs. Solar Domestic Hot Water Heating vs. Solar Cooking Passive vs. Active Solar Thermal Applications Flat Plate Solar Collectors vs. Concentrating Solar Collectors
Passive Solar Principles: Solar Space Heating Insulate, insulate, insulate (especially the North wall) Orient long axis of building E-W Lots of South facing glazing Thermal storage Nocturnal insulation on South wall Summer shading to avoid seasonal over heating
Passive Solar Principles Source: http://www.energysavers.gov/images/five_elements_passive.gif
Passive Solar Principles Source: http://www.solarbuildings.ca/c/sbn/img_db/alstonvale.jpg
Passive Solar Principles
Passive Solar Principles
Passive Solar Principles Thermal Storage Media Solid Thermal Mass Trombe Wall Water Columns, jugs, and barrels Eutectic Salts
Passive Solar Principles
Passive Solar Principles Source: http://www.solar-components.com/bluetub.jpg
Passive Solar Principles Source: http://knowledgepublications.com/heat/images/solar_air_window_box_collectors.gif
Active Solar Space Heating Principles Same as Passive principles, but Add on external solar collectors Add on fans or pumps to move fluid Air or water or other FLUID Different configurations of heat storage May incorporate heat pumps May be flat-plate or concentrating
Active-Solar Air-Heating Principles
Active-Solar Air-Heating Principles Source: http://www.yoursolarlink.com/blog/wp-content/uploads/solar_air_heater.jpg
Active-Solar Air-Heating Principles
Active-Solar Space Heating with Liquid Working Fluids Source: http://www.solarage.co.uk/res/embedded/swhsystem.gif
Solar Domestic Hot Water Heating Can be active or passive (thermo-siphon) Can be open loop Open loop can be drain-down configured for freeze protection Can be closed loop Closed loop can be drain-back configured for freeze protection Closed loop can be freeze protected by using antifreeze as the working fluid
Passive Solar DHW Heating Batch Tank Heating Thermo-siphon
Batch heaters Passive Solar Water Heating
Batch heaters Passive Solar Water Heating
Batch heaters Passive Solar Water Heating Source: http://www.byexample.com/library/photos/projects/batch_collector/bc_01697.jpg
Passive Solar Water Heating Thermo-siphon heaters Source: http://www.altensol.com.ph/?404=y
Schematic diagram of a thermosyphon solar water heater Storage tank Auxiliary Hot water outlet Cold water inlet TEI Patra: 3-18 July 2006 Intensive program: ICT tools in PV-systems Engineering
Laboratory model TEI Patra: 3-18 July 2006 Intensive program: ICT tools in PV-systems Engineering
Typical thermosyphon solar water heater TEI Patra: 3-18 July 2006 Intensive program: ICT tools in PV-systems Engineering
Active Solar DHW Heating System Design Governed by Need for System Efficiency and Freeze Protection
Active Solar Water Heating Source: http://www.amecosolar.com/waterheat.jpg
What type of system would I use in my area? Warm climates systems similar to those shown previously systems will differ in design Cold climates freeze protection becomes critical Indirect systems with heat exchangers Drainback and draindown systems
Warm climates Fluid in tank is heated in collector Most common system in temperate climates
Warm climates This system is called a thermosiphon system. It does not have pumps, controllers, or any moving parts. Water is heated and the density of the hot versus cold water takes over from there. Works off natural thermosiphon actions in moving the water heated in the collector back to the tank and the cold water in the tank to the collector.
Direct circulation system TEI Patra: 3-18 July 2006 Intensive program: ICT tools in PV-systems Engineering
Cold climates Freeze protection Reduce Scale Non-potable fluids
Cold climates Indirect system with heat exchanger that contains fluids in collector that do not freeze. Heat exchanger is in the water heater.
Drain-down system When a freezing condition or a power failure occurs, the system drains automatically by isolating the collector array and exterior piping from the make-up water supply and draining it using the two normally open (NO) valves TEI Patra: 3-18 July 2006 Intensive program: ICT tools in PV-systems Engineering
Indirect water heating system TEI Patra: 3-18 July 2006 Intensive program: ICT tools in PV-systems Engineering
Drain-back system Circulation continues as long as usable energy is available. When the circulation pump stops the collector fluid drains by gravity to a drain-back tank. TEI Patra: 3-18 July 2006 Intensive program: ICT tools in PV-systems Engineering
Cold climates Indirect system with heat exchanger that contains fluids in collector that do not freeze. Heat exchanger is external to the water heater.
In this system all the water in the collector drains back into a reservoir. Cold climates Drainback system T M P C PT T Drain Back Tank Solar Tank Cold Supply
Cold climates In this system, all the water in the collectors drains out of the collector. Draindown system.
Cold climate Another thermosiphon system similar to the one used in warm climates, but this one has a heat exchanger incorporated in the system to protect the collector during freezes. Source: http://mashav.com/solar-energy/sirt.jpg
Stationary Collectors for DHW Flat Plate Collectors Paint or Selective Surface Evacuated Tube Collectors
Flat-plate collector TEI Patra: 3-18 July 2006 Intensive program: ICT tools in PV-systems Engineering
Flat-plate Collectors TEI Patra: 3-18 July 2006 Intensive program: ICT tools in PV-systems Engineering
Types of flat-plate collectors Water systems A Glazing Riser Absorbing plate C Glazing Riser Absorbing plate Insulation Insulation B Glazing Riser Absorbing plate D Glazing Riser Absorbing plate Insulation Insulation TEI Patra: 3-18 July 2006 Intensive program: ICT tools in PV-systems Engineering
Schematic diagram of an evacuated tube collector TEI Patra: 3-18 July 2006 Intensive program: ICT tools in PV-systems Engineering
Evacuated tube collectors Source: http://www.lightheat.com/home_heating/images/the rmomax3.jpg TEI Patra: 3-18 July 2006 Intensive program: ICT tools in PV-systems Engineering
Swimming pool heating -- Another water heating application Source: http://build-it.hit.bg/solar.html TEI Patra: 3-18 July 2006 Intensive program: ICT tools in PV-systems Engineering
Concentrating Collectors Non-Imaging Concentrators Tracked, Imaging Concentrators Refractive vs. Reflective
Refractive Concentrators
Lenses! Refractive, Imaging Concentrators Source: http://3.bp.blogspot.com/_vaxuruxsufa/sxolacmqnyi/aaaaaaaab5s/0mtathc_jni/s200/f_23_2.gif
Lenses! Refractive, Imaging Concentrators Source: http://oscar.iitb.ac.in/images/weeklyimages/physics/single_lens.jpg
Lenses! Refractive, Imaging Concentrators Source: http://artofmanliness.com/wp-content/uploads/2008/04/magnifying-glass.jpg
Lenses! Refractive, Imaging Concentrators
Reflective Concentrators Non-Imaging Tracking not needed.
Flat plate collector with flat reflectors Sun rays Flat plate collector Flat reflector TEI Patra: 3-18 July 2006 Intensive program: ICT tools in PV-systems Engineering
Schematic diagram of a CPC collector θc TEI Patra: 3-18 July 2006 Intensive program: ICT tools in PV-systems Engineering
Reflective Concentrators Imaging Tracking Required!
Parabolic Solar Concentrators Reflective Imaging Concentrators Specially-shaped, highly polished surfaces that reflects light rays, focusing them to a very sharp point on the light-source-side of the reflector MANY more W/m 2 into a VERY small mass or space = MUCH higher temperatures. These are all based on the geometry of the parabola. Line focused = HOT single-axis tracking required Point focused = HOTTER dual-axis tracking required
Line-Focus Reflectors Source: http://www.reuk.co.uk/oth erimages/parabolictrough2.jpg Source: http://cache.io9.com/a ssets/resources/2007/ 11/suncollector.jpg Source: http://teamsuperforest.org/superforest/wp-content/uploads/2010/10/parabolic-trough-500x334.jpg
Parabolic trough collectors TEI Patra: 3-18 July 2006 Intensive program: ICT tools in PV-systems Engineering
Parabolic Trough System Source: http://www.volkerquaschning.de/artikel/konze nson2/abb2.jpg TEI Patra: 3-18 July 2006 Intensive program: ICT tools in PV-systems Engineering
Parabolic trough collectors Source: http://www.tristategt.org/im ages/nrel-solar-troughs- 02.jpg TEI Patra: 3-18 July 2006 Intensive program: ICT tools in PV-systems Engineering
Parabola detail TEI Patra: 3-18 July 2006 Intensive program: ICT tools in PV-systems Engineering
Receiver detail Source: http://erenovable.com/wpcontent/uploads/2009/05/solarpower plant-thumb.jpg TEI Patra: 3-18 July 2006 Intensive program: ICT tools in PV-systems Engineering
Schematic of a parabolic dish collector Sun rays Receiver Parabola Two-axes tracking mechanism TEI Patra: 3-18 July 2006 Intensive program: ICT tools in PV-systems Engineering
Source: http://keetsa.com/blog/wpcontent/uploads/2008/06/solar-dish-1.jpg Point-Focus Reflectors
Solar-Thermal Process-Heat Applications Solar cooking High temperature boilers for steam engines Low temperature boilers for ORC engines Stirling-cycle external combustion heat engines The Minto Wheel and, MORE
Solar Cooking Non-imaging Source: http://www.builditsolar.com/projects/cooking/billspage.jpg
Solar Cooking -- Imaging Source: http://wohnen.pege.org/2005-afrika/solarkocher.jpg
Solar Cooking, Single Hot Dog Scale Source: http://westernpower.com.au/pluginkids/
Village- Scale Solar Cooking
Very High Temp Power Tower! Source: http://ec.europa.eu/energy/res/se ctors/images/solar_3.jpg TEI Patra: 3-18 July 2006 Intensive program: ICT tools in PV-systems Engineering
Schematic of central receiver system TEI Patra: 3-18 July 2006 Intensive program: ICT tools in PV-systems Engineering
Tower detail Source: http://earth2tech.files.wordpres s.com/2009/07/solarthermalge nericnrel.jpg?w=250&h=159 TEI Patra: 3-18 July 2006 Intensive program: ICT tools in PV-systems Engineering
Heliostat detail TEI Patra: 3-18 July 2006 Intensive program: ICT tools in PV-systems Engineering
Mini-Boiler TEI Patra: 3-18 July 2006 Intensive program: ICT tools in PV-systems Engineering
Mini-Boiler Source: http://tonto.eia.doe.gov/energyexpl ained/images/stock/solarth.jpg TEI Patra: 3-18 July 2006 Intensive program: ICT tools in PV-systems Engineering
Central receiver-3 Source: http://www.energy.gov/im ages/gallery/25years- 1996-1998/album_photo96-2_rdax_253x202.jpg TEI Patra: 3-18 July 2006 Intensive program: ICT tools in PV-systems Engineering
Central receiver-4 TEI Patra: 3-18 July 2006 Intensive program: ICT tools in PV-systems Engineering
Central receiver-5 Source: http://www.ecotec2000.de/gr afics/10kw.jpg TEI Patra: 3-18 July 2006 Intensive program: ICT tools in PV-systems Engineering
Mini-Boiler Source: http://bayern.zentru mspartei.de/images/ flugzeug_sbp.jpg TEI Patra: 3-18 July 2006 Intensive program: ICT tools in PV-systems Engineering
Mini-Boiler TEI Patra: 3-18 July 2006 Intensive program: ICT tools in PV-systems Engineering
Mini-Boiler TEI Patra: 3-18 July 2006 Intensive program: ICT tools in PV-systems Engineering
Organic Rankine Cycle Engine
Stirling Cycle Engine
The Minto Wheel
Design Problem Commercial-size Solar Greenhouse Challenges: Maximum sunlight means minimum structure They typically melt off the snow load! Nocturnal insulation in a 2,000 square foot building? Thermal storage? What would you do?