# Application of Internet of Things in a Kitchen Fire Prevention System
## 5 Discussion  
This study originally adopted the normally open solenoid valve for the gas shutoff device. However, this type of valve must be continuously powered on to remain closed, which is unsuitable for use in the shutting off of the gas supply, because gas would continue to be supplied when the valve is not powered, resulting in danger. To completely shut off the gas supply, this study adopted the AD-704T gas shutoff device developed by Sunwe Technology. When the sensors detect flames, high temperatures, or a gas leak, the shutoff device is automatically turned 90 degrees clockwise to shut off the gas supply, ensuring residents' safety.  
The traditional point-type smoke detectors have the disadvantage of not being able to effectively exert their fire detection effects in buildings with large areas and high floors [20; 52]. The biggest drawback of video fire detectors is that these cannot detect early fires in time. This makes it impossible for the system to perform the most effective fire extinguishing function in the early stages of the fire. The flame sensor and temperature sensor used in this study will immediately trigger the sound and  
\begin{table}
\begin{tabular}{c c c c} \hline
**Sensor/Device** & **Startup Value** & **Response Time** & **Complete/Ended Time** \\ \hline Flame detector & \(\leq\)600 & Immediately & N/A \\ \hline Gas methane sensor & \(\geq\)500 & Immediately & N/A \\ \hline Temperature sensor & \(\geq\)50 \({}^{\circ}\)C & Immediately & N/A \\ \hline Sound and light alarm & N/A & Immediately & Detected values below/above startup values \\ \hline Line reporting system & N/A & 1–2 s & Detected values below/above startup values \\ \hline Gas shutoff device & N/A & Immediately & 4–5 s, manually open \\ \hline Front door & N/A & Immediately & N/A, manually lock \\ \hline \end{tabular}
\end{table}
Table 3: The startup value, response time and complete time of sensors/devices used in this study.  
Figure 19: Interface for remotely turning off the gas supply.  
light alarm, transmit the notification messages, cut off the gas supply and open the door lock when the flame intensity or temperature reaches the set value, so as to effectively serve the function of kitchen fire prevention and control.  
When the detected values reach the set values in program, the system starts the relevant facilities immediately. It takes 1-2 s to transfer the Line notification. The gas shutoff device takes 4-5 s to complete the turning off of the gas.  
While the kitchen fire prevention system in this study has sensors and a gas shutoff device, which is the same as the patent TW M501536, it also includes an alarm device, an automatic door unlocking function, and a Line message reporting system, thereby rendering the proposed kitchen fire prevention system more comprehensive.  
This study's system is also similar to the patent TW 201709157 insofar as both systems have an automatic gas shutoff device, a wireless reporting function, and an alarm device. However, the proposed system further includes the functions of the detection of flame, temperature, and gas and automatic door unlocking, which enable the community management team and rescue personnel to immediately enter the house to fight the fire.  
Our team has a lab space wherein the research results of the system have been displayed. There are many members of faculty, students and other users who have been able to experience the system and exchange opinions. Most of the friends and colleagues who have visited have given positive comments. In addition, our research team has organized the user opinions as a reference for future study and as potential direction for improvement of the system.