This paper presents the testing results of three types of fire detectors： electrical heat sensing cable, optical fiber Raman temperature sensing detector, and optical fiber Bragg grating （FBG） temperature sensing d...This paper presents the testing results of three types of fire detectors： electrical heat sensing cable, optical fiber Raman temperature sensing detector, and optical fiber Bragg grating （FBG） temperature sensing detector, in two simulated fire scenes in a cable tunnel. In the small-scale fire with limited thermal radiation and no flame, the fire alarm only comes from the heat sensors which directly contact with the heat source. In the large-scale fire with about 5 ℃/min temperature rising speed within a 3-m span, the fire alarm response time of the fiber Raman sensor and FBG sensors was about 30 seconds. The test results can be further used for formulating regulation for early fire detection in cable tunnels.展开更多
In this work a review of existing fire-detector types has been carried out along with the development of a low cost, portable, and reliable microcontroller based automated fire alarm system for remotely alerting any f...In this work a review of existing fire-detector types has been carried out along with the development of a low cost, portable, and reliable microcontroller based automated fire alarm system for remotely alerting any fire incidents in household or industrial premises. The aim of the system designed is to alert the distant property-owner efficiently and quickly by sending short message (SMS) via GSM network. A Linear integrated temperature sensor detects temperature beyond preset value whereas semiconductor type sensor detects presence of smoke or gas from fire hazards. The sensor units are connected via common data line to ATMega8L AVR microcontroller. A SIM300CZ GSM kit based network module, capable of operating in standard GSM bands, has been used to send alert messages. The system is implemented on printed circuit board (PCB) and tested under different experimental conditions to evaluate its performances.展开更多
To achieve fire prevention in heritage buildings,it is crucial to identify,analyse,and assess fire risks prior to fires due to the complexity of fire causes and risk factors influenced by various aspects such as envir...To achieve fire prevention in heritage buildings,it is crucial to identify,analyse,and assess fire risks prior to fires due to the complexity of fire causes and risk factors influenced by various aspects such as environmental factors,building material characteristics,layout and management/maintenance practices.For building-specific fire risk identification,fire process simulation models constructed based on quantifying various fire risk elements are needed.Some studies have found that indoor microclimate has different degrees of influence on the fire development process,but there is a lack of relevant modelling.Taking the Grand Hall of Baoguo Monastery in Ningbo as an example,32 fire operating conditions were simulated using the Fire Dynamics Simulator based on the monitoring environment data collected in the hall.The results revealed that the building structural nodes had higher fire risks,the wind direction significantly affected fire spread in the hall,ambient temperature could influence the fire development rate,smoke was more easily detected at the ceiling,and except for the temperature change(P<0.01),the other indicators did not differ significantly across environmental conditions.Subsequently,a fire detector installation strategy with temperature,CO concentration and smoke detectors as detection indicators was proposed.展开更多
基金This work was supported by the Chinese National Science Foundation under Grant 51275373 and the Chinese Fundamental Research Funds for the Central University under Grant 2012-IV -019.
文摘This paper presents the testing results of three types of fire detectors： electrical heat sensing cable, optical fiber Raman temperature sensing detector, and optical fiber Bragg grating （FBG） temperature sensing detector, in two simulated fire scenes in a cable tunnel. In the small-scale fire with limited thermal radiation and no flame, the fire alarm only comes from the heat sensors which directly contact with the heat source. In the large-scale fire with about 5 ℃/min temperature rising speed within a 3-m span, the fire alarm response time of the fiber Raman sensor and FBG sensors was about 30 seconds. The test results can be further used for formulating regulation for early fire detection in cable tunnels.
文摘In this work a review of existing fire-detector types has been carried out along with the development of a low cost, portable, and reliable microcontroller based automated fire alarm system for remotely alerting any fire incidents in household or industrial premises. The aim of the system designed is to alert the distant property-owner efficiently and quickly by sending short message (SMS) via GSM network. A Linear integrated temperature sensor detects temperature beyond preset value whereas semiconductor type sensor detects presence of smoke or gas from fire hazards. The sensor units are connected via common data line to ATMega8L AVR microcontroller. A SIM300CZ GSM kit based network module, capable of operating in standard GSM bands, has been used to send alert messages. The system is implemented on printed circuit board (PCB) and tested under different experimental conditions to evaluate its performances.
基金supported by the foundation of Jiangsu Province Engineering Research Center of Construction Carbon Neutral Technology(No.JZTZH 2022-0101)。
文摘To achieve fire prevention in heritage buildings,it is crucial to identify,analyse,and assess fire risks prior to fires due to the complexity of fire causes and risk factors influenced by various aspects such as environmental factors,building material characteristics,layout and management/maintenance practices.For building-specific fire risk identification,fire process simulation models constructed based on quantifying various fire risk elements are needed.Some studies have found that indoor microclimate has different degrees of influence on the fire development process,but there is a lack of relevant modelling.Taking the Grand Hall of Baoguo Monastery in Ningbo as an example,32 fire operating conditions were simulated using the Fire Dynamics Simulator based on the monitoring environment data collected in the hall.The results revealed that the building structural nodes had higher fire risks,the wind direction significantly affected fire spread in the hall,ambient temperature could influence the fire development rate,smoke was more easily detected at the ceiling,and except for the temperature change(P<0.01),the other indicators did not differ significantly across environmental conditions.Subsequently,a fire detector installation strategy with temperature,CO concentration and smoke detectors as detection indicators was proposed.
