Dr. HoSung Lee
1 Thermal Design Examples Heat Sinks Thermoelectric coolers and generators Heat Pipes Compact Heat Exchangers Solar Cells
2 Heat Sinks
3 Thermoelectric Generators and Coolers
Heat Absorbed
p
n
p n-type Semiconductor n n p Positive (+) p n p-type Semiconcuctor p
Negative (-) Electrical Conductor (copper) Electrical Insulator (Ceramic) Heat Rejected
5 Heat Pipes
6 Compact Heat Exchangers
7 Solar Cells
8 Sun-tracking panels
9 10 Solar Thermoelectric Generator (STEG)
11 Solar Thermoelectric Generator
12 Kusatsu Hot-springs TEG System
13 Thermoelectric Modules (old & modern)
1950s
2012 Kerosene lamp and radio
14 15 16 17 Thermoelectric Cooler Module
Heat Absorbed
p
n
p n-type Semiconductor n n p Positive (+) p n p-type Semiconcuctor p
Negative (-) Electrical Conductor (copper) Electrical Insulator (Ceramic) Heat Rejected
System Designers having difficulties •Most of manufacturers do not provide the material properties (Manufacturers’ proprietary information)
18 Thermoelectric Modules
19 Solar Thermoelectric Generator
Nature Materials 10, 532-538 (2011)
20 Thermoelectric Heat Exchanger
21 Thermoelectric Heat Exchanger This study investigates the feasibility of integrating thermoelectric devices into a large-capacity liquid heat exchanger (up to 100 kW). Typically, thermal-electrical conversion is inefficient and thermoelectrics are only used in low-power applications (<1 kW). The incentive for using thermoelectrics, however, lies in their compact size, light-weight, high reliability, and sub-ambient cooling. In this study, a subscale thermoelectric heat exchanger is designed (see Fig. 1), fabricated and optimized for performance through testing and simulation. Specifically, direct fluid contact and jet-impingement were used to improve heat transfer at both hot and cold junctions of the thermoelectric. A schematic of the design concept can be seen in Fig. 2. This approach resulted in a five-fold increase in the cooling coefficient- of-performance. Experimentally validated predictions also demonstrated that a 100-kW heat exchanger is lighter per unit-power than comparable vapor-compression systems. This feasibility study raises the outlook of reducing thermoelectric technology to practice in large heat load applications.
22 HYBRID SOLAR PANEL DIAGRAM
HYBRID SOLAR PANEL DIAGRAM The hybrid solar panel that Yin designed has as its outermost layer a clear protective cover, followed by a layer of thermoelectric material, a layer with plastic tubes (called the functionally graded material interlayer) to carry water that will cool the other layers while also carrying away heated water, and a bottom layer of reinforcing plastic. Image: © COLUMBIA UNIVERSITY
23 Air-to-Air Thermoelectric Heat Exchangers BSST's parent company, ships more than 1.2 million thermoelectric Air to Air devices to automobile seat manufacturers annually, making possible the cooled and heated car seats available on many car models. Building on this technology and manufacturing expertise, BSST has created Air to Air devices that provide electronic enclosure cooling at nearly double the efficiency of standard thermoelectric cooling devices.
24 Air-to-solid Thermoelectric Heat Exchangers
25 Liquid-to-air Thermoelectric Heat Exchanger
BSST's uniquely designed Liquid to Air systems allow for significant cooling power in a variety of form factors. In a typical BSST configuration, ambient air enters the device and is instantly chilled to approximately 15 degrees Celsius. The air is then blown over electronic systems or critical components. The waste heat from the process is removed by the liquid loop (typically water, but other fluids can be used).
26 Cold Plate Cooler
27 Bio-medical Experiment Two-Temperature Reference TEC
28 Microprocessor Cooling (160W)
29 Miniature Thermoelectric Coolers
30 Thermoelectric Cooler for Telecom Laser
31 Butterfly Package for Telecom Laser
32 Butterfly Package for Telecom Laser
33 Dimensions for Butterfly Package
34 Butterfly Package for Telecom Laser Small sized Relatively low price Long lifetime
35 Isometric View (ANSYS)
36 Laser Butterfly
37 Laser Butterfly
38 High-Tech Radio inside the Wing of a Fighter Aircraft
39 Remote Thermoelectric Generator Power generation: 120 Watts Fuel: natural gas
40 Thermoelectric Cooling Helmet
41 42 Thermoelectric Exhaust Systems
43 44 Waste Heat Recovery
45 Auto Exhaust Can Generate Thermoelectric Power
About 40 percent of the energy from gasoline or diesel fuel is wasted as exhaust heat. If you can convert some of that heat to electricity, it can provide electric power for automotive accessories, relieving some of the burden from the engine resulting in better fuel economy. The device that performs this conversion is a thermoelectric generator and GM has been working on developing one to either assist or even replace the vehicle's alternator.
46 47 Automotive Air Conditioning
48 Automotive HVAC
49 Automotive Thermoelectric Air Conditioner (TEAC)
50 OTEC (Ocean Thermal Energy Conversion)
Bi-Te element size: 10 x 1.5 mm. Total number of n-p couples: 10,000 couples/ Number of TEG modules: 500 modules.
51 Develop Tables for Optimal Design
Table 1 Optimal Power Output for ZT∞2=1 T∞* Nh Rr Nk ηth Wn* T1* T2* NI NV 1.0 0.1 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 1.0 1.0 0.000 0.000 0.000 0.000 1.000 1.000 0.000 0.000 1.0 10.0 0.000 0.000 0.000 0.000 1.000 1.000 0.000 0.000 1.005 0.1 1.564 0.063 4.36E-04 9.72E-08 1.003 1 9.93E-04 1.55E-03 1.005 1 1.564 0.063 7.27E-04 2.71E-07 1.005 1 1.66E-03 2.60E-03 1.005 10 1.564 0.063 7.80E-04 3.12E-07 1.005 1 1.78E-03 2.78E-03 1.01 0.1 1.564 0.063 8.70E-04 3.88E-07 1.006 1 1.99E-03 3.11E-03 1.01 1 1.564 0.063 1.45E-03 1.08E-06 1.009 1.001 3.32E-03 5.19E-03 1.01 10 1.42 0.65 8.51E-04 3.89E-06 1.01 1.005 2.05E-03 2.92E-03 1.015 0.1 1.564 0.063 1.30E-03 8.73E-07 1.008 1.001 2.98E-03 4.66E-03 1.015 1 1.416 0.356 1.28E-03 4.82E-06 1.011 1.004 3.09E-03 4.38E-03 1.015 10 1.421 0.649 1.28E-03 8.75E-06 1.014 1.007 3.08E-03 4.38E-03 1.02 0.1 1.564 0.063 1.74E-03 1.55E-06 1.011 1.001 3.97E-03 6.21E-03
52 Radioisotope Thermoelectric Generator (RTG)
53 Curiosity Rover in Mars
54 MMRTG cutaway
55 56 Plutonium 238
Radioactive isotope of plutonium with a half- life of about 87 years and is a very powerful alpha ray emitter
57 RTG
The heat produced by the decay of Plutonium-238 can be converted to electricity by a TEG
58 Schematic Diagram of an RTG System
59 RTG Applications in Industry
RTGs are usually the most desirable power source for unmanned or unmaintained situations requiring small amount of power for durations too long for fuel cells, batteries and generators Satellites Space Probes Unmanned Remote Facilities Lighthouse Beacons
60 Pacemaker The latest pacemakers are powered by radioactive isotopes for long life and weigh no more than 15 g and about 3 cm in diameter. The cost is about $10,000 to $15,000 It is made up of two parts: A pulse generator, which includes the battery and several electronic circuits Wires, called leads, which are attached to the heart wall
61 Waste Heat Recovery Geothermal Energy
62 Home Power Station
One possible use for thermoelectric generators is to provide supplemental or back-up electricity for home owners who use outdoor wood/biofuel furnaces.
63 TEG installation on Stove
64 Heat Pipes in a Laptop Computer
65 Heat Pipes for Cooling in a Laptop
66 Design Temperature control of CPU
67 Novel Heating System Could Improve Electric Car’s Range
Buyers considering an electric car must bear in mind that using battery-powered heating and air conditioning can decrease the car’s range by a third or more (see “BMW’s Solution to Limited Electric- Vehicle Range: A Gas-Powered Loaner”). A New York Times reviewer recently ran into this problem on a test drive, ending up stranded with a dead battery (see “Musk-New York Times Debate Highlights Electric Cars’ Shortcomings”). But a heating and cooling system under development almost eliminates the drain on the battery. The researchers are working with Ford on a system that they hope to test in Ford’s Focus EV within the next two years. The work is being funded with a $2.7 million grant from the Advanced Research Projects Agency for Energy. The researchers describe their new device as a thermal battery. It uses materials that can store large amounts of coolant in a small volume. As the coolant moves through the system, it can be used for either heating or cooling. In the system, water is pumped into a low-pressure container, evaporating and absorbing heat in the process. The water vapor is then exposed to an adsorbant—a material with microscopic pores that have an affinity for water molecules. This material pulls the vapor out of the container, keeping the pressure low so more water can be pumped in and evaporated. This evaporative cooling process can be used to cool off the passenger compartment. Power saver: A proof-of-concept heating and cooling system for electric vehicles works without battery power. 68 Novel Heating System Could Improve Electric Car’s Range
As the material adsorbs water molecules, heat is released; it can be run through a radiator and dissipated into the atmosphere when the system is used for cooling, or it can be used to warm up the passenger compartment. The system requires very little electricity—just enough to run a small pump and fans to blow cool or warm air. Eventually the adsorbant can’t take in any more water, but the system can be “recharged” by heating the adsorbant above 200 °C. This causes it to release the water, which is condensed and returned to a reservoir. An electric heater could be used for this purpose, says Evelyn Wang, a professor of mechanical engineering at MIT, who is leading the work. “But there so many sources of heat, such as heat from a solar water heater—so electricity wouldn’t have to be used,” she says. Fully recharging the system is expected to take about four hours, which is about what it takes to recharge some common electric vehicles at standard charging stations. The basic concept behind the temperature control system isn’t new (see “Using Heat to Cool Buildings”). But it’s been difficult to make such a system compact enough for use in a car, especially because separate containers are normally used for evaporating and condensing the coolant. The researchers’ more compact design uses one container for both purposes. The researchers are now developing materials that can adsorb more water, which would make it possible to use less adsorbant. One is a modified zeolite, a type of porous material that has long been used in catalysis. They’re also working on a material called a metal organic framework, whose properties can be systematically changed by varying the composition of organic materials that link microscopic clusters of metal. The researchers have added highly thermally conductive materials such as carbon-based nanomaterials to their adsorbant so the system can heat and cool more rapidly, which can also make it possible to shrink its overall size.
69 Solar Evacuated Tube Collector (heat pipe)
70 Solar Heat Pipe TEG
71 Heat Fins Along Pipeline Melted permafrost could result in sinking or collapse of pipeline
72 Pipeline Cross Section
Heat Fins Hot Oil Flow
Heat Pipes Heat Conducts Down Support Beams
Condensation and Evaporation of Ammonia
Permafrost
73 Heat Pipe Glove
frostbite prevention
74 Heat Pipe Exchanger
75 Compact Heat Exchangers
76 Plate Heat Exchanger
77 78 Thermoelectric Cooler
79 Thermoelectric cooler
80 Car seat climate control
81 82 CLIMATE CONTROL .Thermoelectric based cooling/heating
83 84 USS DOLPHIN AGSS 555 Thermoelectric Air Conditioning Test for Silent Running
85 Spacecraft Using Radioisotope Thermoelectric Generators
86 87 88 Thermoelectric generator module
89 TEG Simulations (ANSYS)
90 TEG Temperature Simulations
91 92 Shell and Tube Heat Exchanger
Baffles
Tubes Shell fluid constrained
Tube fluid
93 Mesh Application – Corrections
94 Vectors of Velocity Magnitude
95 Hand phone charger by body heat
96 Personal Mini Cooler
Personal Mini Cooler thermoelectric cool/heat mini cooler Specifications: Dimensions: 2.75 (width) X 1.20 (thick) X 5.60 (height) Inches Cold Temperature: Up to 25℃ below Ambient Temperature Weight: 4.00 oz.(without batteries) Blue Disk: Polished & Anodized Aluminum,1.4 inch diameter Blue Disk Power: Four AA size NICKEL-METAL HYDRIDE (Ni-MH).1200 mA rechargeable Batteries.(Not supplied) or regular AA”Energizer” type batteries Case: ABS Plastic
97 Dispenser-Printed TEG Characteristics Planar thick film (strip) TEG properties: Dimensions 5 푚푚 × 640 μ푚 × 90μ푚 Material and 푍푇 at 302 퐾 Size of one TEG strip
N-type: Bi2Te 3 epoxy composite (푍푇 = ퟎ. ퟏퟖ)
P-type: Sb2Te 3 epoxy composite (푍푇 = ퟎ. ퟏퟗ) Manufacturing method Dispense printing Primary materials mixed with Size of TEG strips epoxy resins to form inks stacked in parallel Performance of Thermoelectric materials
99 Si Nanowires, (Nature Vol. 451, 2008, Caltech and UC Berkeley) Silicon bulk ZT ≈ 0.01
Silicon nanowires ZT ≈ 1
100 Thermoelectric Cooler driven by Solar Cells
101 Solar Driven Thermoelectric Cooling Headgear
102 Hybrid Solar Cell and TEG
103 TEG with Solar Collector
104 Heat Pipes for Cooling Microprocessor
105 Solar Thermoelectric Generators
106 107 Miniature Thermoelectric Devices
RMT
Snyder et al. (2003) Thermoelectric Devices Miniature Thermoelectric Devices
TEC TEG
110 111 Seat climate technology: We set tomorrow's standards for comfort Car Seat Cooling/Heating
112 Low-Grade (100 C) Heat Recovery
113 The End
114