Device for Limiting the Temperature at Chimney-Roof Penetration in Very Critical Chimney Operating Conditions
| Autor: | Manuela Neri, Mariagrazia Pilotelli |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 2019 |
| Předmět: |
Materials science
Nuclear engineering Chimney-roof penetration Thermal bridges 020101 civil engineering Fire safety 02 engineering and technology Temperature limitation 0201 civil engineering chemistry.chemical_compound Chimney-roof penetration Device Fire safety Roof fires Temperature limitation Thermal bridges Heat recovery ventilation Thermal Device General Materials Science Chimney Safety Risk Reliability and Quality Roof Electrical conductor 040101 forestry Flammable liquid Exhaust gas 04 agricultural and veterinary sciences Roof fires chemistry Heat transfer 0401 agriculture forestry and fisheries |
| Popis: | In recent years, numerous roof fires have occurred due to the presence of a chimney, and also certified chimneys were involved. Chimneys installers and chimney producers are disoriented because the chimney certification does not guarantee safe installations, and also the performance of devices for limiting the roof temperature is uncertain. Results reported in this paper will help them to accomplish safe chimney installations. The paper describes the main features of a device to be installed at chimney-roof penetration for limiting flammable materials temperature and, consequently, the roof fires risk. The device is composed of elements made of insulating material to reduce the heat transfer from the chimney towards the roof, and elements made of conductive material to facilitate the heat transfer from the device itself towards the ambient. The features of the device have been investigated by means of 32 numerical simulations performed with a CFD code: in each numerical test a variable has been changed and the conditions that have determined the lowest roof temperature have been considered the most suitable. If compared to the temperature measured when only insulating material is installed at chimney-roof penetration, the conductive elements reduce the roof temperature of more than $$100^{\circ }\hbox {C}$$ . The optimal version of the device, that is, 100 mm thick and made of two conductive elements ensures a roof temperature lower than $$85^{\circ }\hbox {C}$$ when the exhaust gas temperature in the chimney is $$1000^{\circ }\hbox {C}$$ in steady conditions. In addition, the device avoids the formation of thermal bridges between indoor and external ambient, and it engenders heat recovery in indoor ambient. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
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