Heat transfer intensification in emergency cooling heat exchanger and dry cooling towers on nuclear power plant using air-water mist flow
Электронный научный архив УРФУ
Информация об архиве | Просмотр оригинала| Поле | Значение | |
| Заглавие |
Heat transfer intensification in emergency cooling heat exchanger and dry cooling towers on nuclear power plant using air-water mist flow
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| Автор |
Abed, A. H.
Shcheklein, S. E. Pakhaluev, V. M. |
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| Тематика |
AEROSOL COOLING
AIR-WATER MIST HEAT EXCHANGE INTENSIFICATION NUCLEAR POWER PLANTS WATER CONCENTRATION |
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| Описание |
Advanced nuclear power plants are equipped with passive emergency heat removal systems (PEHRS) for removing the decay heat from reactor equipment in accidents accompanied by primary circuit leakage to the final heat absorber (ambient air). Herein, the intensity of heat dissipation to air from the outer surface of the heat exchanger achieved by buoyancy induced natural convection is extremely low, which need to a large heat exchanger surface area, apply different types of heat transfer intensification including (grooves, ribs and extended surfaces, positioning at higher altitudes, etc.). The intensity of heat removal is also strongly dependent on the ambient air temperature (disposable temperature head). Construction of nuclear power plants in countries with high ambient temperatures (Iran, Bangladesh, Egypt, Saudi Arabia, and others) which are characterized by a high level of ambient temperature imposes additional requirements on the increase of the heat exchange surfaces. The experimental investigation results of heat transfer intensification by a low energy ultrasonic which supply a fine liquid droplet (size ~3 µm) in the cooling air are presented in the present paper. In such case, the heat transfer between the surface and cooling flow involves the following three physical effects: convection, conductive heat transfer, and evaporation of water droplets. The last two effects weakly depend on the ambient air temperature and provide an active heat removal in any situation. The investigation was performed using a high-precision calorimeter with a controlled rate of heat supply (between 7800 and 12831 W/m2) imitating heated surface within the range of Reynolds numbers from 2500 to 55000 and liquid (water) flow rates from 23.39 to 111.68 kg·m-2·h-1. The studies demonstrated that the presence of finely dispersed water results in a significant increase in heat transfer compared with the case of using purely air-cooling. With a fixed heat flux, the energy efficiency increases with increasing water concentration, reaching the values over 600 W·m-2·C-1 at 111.68 kg·m-2·h-1, which is 2.8 times higher than for air cooling. With further development of research in order to clarify the optimal areas of intensification, it is possible to use this technology to intensify heat transfer to the air in dry cooling towers of nuclear power plants and thermal power plants used in hot and extreme continental climates. © 2019, Pensoft Publishers. All rights reserved.
Government Council on Grants, Russian Federation The present study was implemented under the financial support in pursuance with Resolution No. 211of the Government of the Russian Federation under Contract No. 02.A03.21.0006. |
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| Дата |
2024-04-23T11:10:50Z
2024-04-23T11:10:50Z 2019 |
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| Тип |
Article
Journal article (info:eu-repo/semantics/article) Published version (info:eu-repo/semantics/publishedVersion) |
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| Идентификатор |
Abed, A. H., Shcheklein, S. E., & Pakhaluev, V. M. (2019). Heat transfer intensification in emergency cooling heat exchanger and dry cooling towers on nuclear power plant using air-water mist flow. Nuclear Energy and Technology, 5(4), 281–287. doi:10.3897/nucet.5.47972
2452-3038 Final All Open Access, Gold, Green https://nucet.pensoft.net/article/47972/download/pdf/ http://elar.urfu.ru/handle/10995/132542 10.3897/nucet.5.47972 85144673321 |
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| Язык |
en
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| Права |
Open access (info:eu-repo/semantics/openAccess)
cc-by |
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| Формат |
application/pdf
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| Издатель |
Pensoft Publishers
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| Источник |
Nuclear Energy and Technology
Nuclear Energy and Technology |
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