Thermal behavior of heat-pipe-assisted alkali-metal thermoelectric converters
Autor: | Seok-Ho Rhi, Seon Yong Jeong, Kye-Bock Lee, Ji-Su Lee, Wook-Hyun Lee, Won-Sik Chung, Jong-Chan Park, Ri-Guang Chi |
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Rok vydání: | 2017 |
Předmět: |
Fluid Flow and Transfer Processes
Materials science business.industry 020209 energy 02 engineering and technology 021001 nanoscience & nanotechnology Condensed Matter Physics Heat pipe Thermal radiation Shield Thermoelectric effect 0202 electrical engineering electronic engineering information engineering Working fluid Composite material 0210 nano-technology business Condenser (heat transfer) Evaporator Thermal energy |
Zdroj: | Heat and Mass Transfer. 53:3373-3382 |
ISSN: | 1432-1181 0947-7411 |
DOI: | 10.1007/s00231-017-2077-5 |
Popis: | The alkali-metal thermal-to-electric converter (AMTEC) changes thermal energy directly into electrical energy using alkali metals, such as sodium and potassium, as the working fluid. The AMTEC system primarily consists of beta-alumina solid electrolyte (BASE) tubes, low and high-pressure chambers, an evaporator, and a condenser and work through continuous sodium circulation, similar to conventional heat pipes. When the sodium ions pass through the BASE tubes with ion conductivity, this ion transfer generates electricity. The efficiency of the AMTEC directly depends on the temperature difference between the top and bottom of the system. The optimum design of components of the AMTEC, including the condenser, evaporator, BASE tubes, and artery wick, can improve power output and efficiency. Here, a radiation shield was installed in the low-pressure chamber of the AMTEC and was investigated experimentally and numerically to determine an optimum design for preventing radiation heat loss through the condenser and the wall of AMTEC container. A computational fluid dynamics (CFD) simulation was carried out to decide the optimum size of the low-pressure chamber. The most suitable height and diameter of the chamber were 270 mm and 180 mm, respectively, with eight BASE tubes, which were 150 mm high, 25 mm in diameter, and 105 mm in concentric diameter. Increasing the temperature ratio (T Cond /T B ) led to high power output. The minimum dimensionless value (0.4611) for temperature (T Cond /T B ) appeared when the radiation shield was made of 500-mesh nickel. Simulation results for the best position and shape for the radiation shield, revealed that maximum power was generated when a stainless steel shield was installed in between the BASE tubes and condenser. |
Databáze: | OpenAIRE |
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