Design of Intelligent Fire Extinguishing System of Interior Large Space Guoliang Hu
Zhong Li
Key Laboratory of Ministry of Education for Conveyance and Equipment East China Jiaotong University Nanchang, China e-mail:
[email protected]
Key Laboratory of Ministry of Education for Conveyance and Equipment East China Jiaotong University Nanchang, China e-mail:
[email protected]
Abstract—With the constantly development of large space, the fire prevention of large space building is also increasingly important, but the traditional fire extinguishing system can not satisfy the requirements of fire extinguishing of interior large space. An intelligent fire extinguishing system of interior large space that using the single chip microcomputer SPCE061A as the main controller was designed. The fire location was detected with two-level flame sensors, and the detecting signal was transmitted to the single chip microcomputer SPCE061A. Two perpendicular stepper motors which was driven by the single chip microcomputer drive the fire extinguishing system rotating to achieve the space location of the fire. The test results shows that the system had low rate of false alarm, and the detection method is also simple and stabel, which can satisfy the requirements of early fire prevention in large space. Keywords-fire extinguishing system, auto-targetting, large space
find, accurately locate and initiatively spray. So it is suitable for the fire prevention of interior large space [1-2].
I.
INTRODUCTION
With the rapid development of interior large space building, the fire prevention of interior large space building has been more and more important. Because of the structural characters of interior large space, its fire prevention is different from the conventional architecture. Now the main equipments of fire prevention are interior sprinkling system, the fire water monitor, automatic sprinkling system, and so on, however, the spraying direction and area of interior sprinkling system is fixed and scattered, it also hasn’t the function of auto-targeting, so it doesn’t make full use of water and not have the ideal fire fightting results. Fire water monitors of interior large space need to be under the control of the fire person, it takes long time to prepare that it can not put out the fire in time. The structure of the automatic sprinkling system is much more complicated, and the sprinkler need to be replaced in case of the next fire protection tasks. Therefore, they are also unable to meet large space requirements of fire prevention. Aiming at the problems mentioned above, an intelligent fire extinguishing system of interior large space that using the SPCE061A as the main controller was designed; its mechanical structure and the hardware and software of electrical control system were analyzed in detail. This fire extinguishing system could initiatively monitor, automatically
II.
DESIGN OF MECHANICAL STRUCTURE OF INTELLIGENT FIRE EXTINGUISHING SYSTEM
A. Design requirements and parameters (1) Protection height 10m; (2) Protection Radius 15m; (3) Spraying flow 5L/s; (4) Working pressure 0.25~0.6MPa;(5) Interface diameter 25mm; (6) Nozzle diameter Ø16mm; (7) Input voltage AC220V; (8) The time of searching fire 30s; (9) Operating temperature 10oC~55oC. B. Working Principle According to the design requirements, the designed mechanical structure of the fire extinguishing system is shown in Figure 1, and the 3d model of the system is shown in Figure 2. As shown in the two figures, the horizontal auto-targeting system and the vertical auto-targeting system are driven by involute worm wheel and worm and spur-gear. Because of the self-locking performance of involute worm wheel and worm, the system would not be affected by the opposite forces of water flow and maintained the original positioning accuracy. The horizontal auto-targeting system and the vertical auto-targeting system are separately driven by two stepper motors that the rotation centers of the two stepper motors are perpendicular to each other. The horizontal stepper motor drive the worm by the key, thus the worm wheel 1 and the small gear 2 are driven, so the large gear 15 and the whole system rotate back and forth for 360o in the horizontal direction. After the horizontal position of fire is located, the worm 10 is driven by the vertical stepper motor 11, thus the worm wheel 12 and the small gear 6 are driven, so the large gear 5, the water outlet pipe 4 and the nozzle 8 swing for 90o in the vertical direction. The horizontal auto-targeting system and the vertical auto-targeting system are installed limited mechanism The limited rods which are installed on the large gear 15 and the large gear 5 touch the limited switchs which are installed on the roof 18 and the connecting water pipe 13 to limit the position of the horizontal and vertical direction.The nozzle 8 is connected with the water outlet pipe 4 by thread, the water outlet pipe 4 is connected with the inlet pipe 15 by the connecting water pipe 13, the water flow from the inlet pipe 15 to the nozzle 8.
Supported by the Young Scientists and Jinggang Star of Jiangxi Province under the grant No. 2009DQ01100 and by the National Natural Science Foundation of China under the grant No. 50865004.
978-1-4244-7161-4/10/$26.00 ©2010 IEEE
product of DSP, but also processes quickly the complex digital signals. SPCE061A which has the modular integrated structure integrate high-addressing capacity ROM, static RAM, and multi-function I/O Interface, it has two 16-bit programmable timers and counters, fourteen interrupt sources, two 10-bit DAC output channels, 7-channel and 10-bit ADC and single-channel audio ADC and 32-bit general input or output ports [3].
1.worm wheel 2.small gear 3.limited rod 4.water outlet pipe 5.large gear 6.small gear 7.vertical flame sensor 8.nozzle 9..horizontal flame sensor 10.worm 11. vertical stepper motor 12.worm wheel 13. onnecting water pipe 14. connecting tube 15.inlet pipe 16.large gear 17.mantle 18.roof Figure 1.
Figure 2.
III.
the structure of intelligent fire extinguishing system
3D model of intelligent fire extinguishing system
DESIGN OF THE HARDWARE OF ELECTRICAL CONTROL SYSTEM
B. Hardware components and interfaces The control section of intelligent fire extinguishing system includes: SPCE061A, power circuit, the driving circuit of detecting sensor, the driving circuit of horizontal and vertical flame sensor, the driving circuit of stepper motor, alarm Circuit, communication module and so on. According to the detecting signal, SPCE061A drive the horizontal and vertical stepper motors to rotate by driving cricuit, and it control the rotating direction of the horizontal and vertical stepper motors according to the signal of limited switch while the buzzer is diven to alarm by the alarm cricuit, moreover, SPCE061A communicates with the host computer through RS232. The whole connection diagram of the fire extinguishing system is showed in Figure 4. IOA ports were set to input ports, as follows: the input ports of manual remote control were IOA0~IOA8, the signal input ports of the horizontal and vertical stepper motor were IOA2 and IOA3, the signal input ports of three flame sensors were IOA9~IOA11, the signal input ports of four limited switchs were IOA12~IOA15. IOB ports were set to ouput ports, as follows: RS232 serial communication ports were IOB7~IOB10, alarm signal output port was IOB11, the output ports of the rotating direction signal of the horizontal and vertical stepper motors were IOB12~IOB13, the output ports of the pulse control signal of the horizontal and vertical stepper motors were IOB14~IOB15.
A. Microcontroller
Figure 4.
Figure 3.
the internal structure of SPCE061A
The internal structure of APCE061A is showed in Figure 3, SPCE061A is a 16 bit Microcontroller and Signal Processor which is small and has high integration level, good reliability, easy expansion and strong interrupt handling. So it not only is able to complete 16×16 bit multiplications and the inner
the whole connection of fire extinguishing system
C. Power circuit Because of the civil voltage is 220V, however, the voltage that control circuit need is +5V, +12V or +24V. So the power circuit was designed. The power circuit structure is showed in Figure 5. Firstly, the 24V DC power supply change 220V to 24V DC voltage. Secondly㧘the capacitor and inductor filter the voltage and the zener diode regulate the voltage. Finally, the three-terminal regulator chips that is KA7812 and KA7805 change the voltage to +5V and +12V DC voltage and
2 1
C2 INDUCTOR L2 C1 0.01
F1
R2
10A
P+5V WARN1
BUZZER R5 RES1
0.01 U2 VOLTREG 1
Vin
RES1
GND
DC24VIN
baojing
provide it to the control circuit. If the power suddenly fails, the backup power will provide the voltage.
Vout
+5VB
3
N
2
RBWAR1
D1
U1 VOLTREG 1
Vin
RES1
Vout
3
10A
IV.
U2 1
RES1
Vin
VOLTREG Vout
3
+5V
2
24V
R2
GND
BT1
\ Figure 5.
power circuit
D. Sensor and its driving circuit Sensor and its driving circuit are the important parts of the control system of intelligent fire extinguishing system. The main function of senor and its driving circuit is that they collect the signal of the fire timely and accurately and convert the signal to the electric signal and deliver it to SPCE061A. R2868 is a UV TRON ultraviolet detector that makes use of the photoelectric effect of metal and the gas multiplication effect, so it can find the distant flame and even can detect the flame of a cigarette lighter at a distance of more than 5m. It has a narrow spectral sensitivity of 185 to 260 nm, being completely insensitive to visible light. Unlike semiconductor detectors, it does not require optical visible-cut filters, thus making it easy to use.
Figure 6.
Figure 7.
+12V
2
10A D3
R1
GND
10A D2
50K
P24V
alarm circuit
DESIGN OF THE SOFTWARE OF ELECTRICAL CONTROL SYSTEM
Software which was designed to be modular and used C language mainly consists of the main program and the subprograms. Main program initializes the system and call subprograms. The subprogram such as port initialization, stepper motor reset, sensor detection, the left and right rotation of horizontal stepper motor, the up and down rotation of vertical stepper motor, manual romote control, alarm and delay time severally complete the control processes. Program is compiled and debugged by the integrated Development Environment of μ’nSP IDE which have a kind interface to make programming and debugging easy and efficient.
C3704
The senor driving circuit is C3704, as shown in Figure 6. C3704 series UV TRON driving circuits are low current consuming, signal processing circuits for the UV TRON, well known as a high sensitivity ultraviolet detecting tube. C3704 can be operated when it is provided 10V to 30V DC voltage and connect with R2868, as they have both a high voltage power supply and a signal processing circuit on the same printed circuit board. So it can provide 350V supply voltage to R2868 [3]. E. Alarm Circuit The way of alarm is buzzer alarm, its alarm circuit is shown in Figure 7. IOB11 as the signal input port of alarm circuit connect with alarm circuit. The buzzer is driven to alarm by the alarm signal amplified by the NPN-type transistor.
Figure 8.
the flow chart of main program
Figure 8 is a flow chart of main program. When the system start working, the main program firstly initializes the system, then stepper motors reset and the detecting sensor is open. If there is not the detecting signal, the detecting sensor continue to monitor, otherwise, if the manual remote control is open, the main program call the subprogram of manual remote control, if there is not, the main program orderly call the alarm, horizontal scanning, vertical scanning, fight fire, close valve subprograms to complete the process of fighting fire and use *P_Watchdog_Clear=0x0001 to cleal watchdog.
on the roof high above the ground 5m, and a fire was set up about 5m away from it. When the power open, the system could timely and accurately detect, find, and locate the fire according to the requirement of the programs. The locating time was about 10s, so the system met the design requirement.
Figure 10.
VI.
the scene debugging
CONCLUSION
This intelligent fire extinguishing system achieved the target of auto-detecting, automatically finding and locating, active fighting. At the same time, because of the chip SPCE061A is very cheap and high performance, this auto-targeting fire extinguishing system has lower cost, better stability and better market prospects. REFERENCES Figure 9.
the flow chart of manual remote control subprogram
In addition to automatic search mode, the system also has a manual remote control mode, the operator can control fire extinguishing system to fight fire by manual remote control. Figure 9 is the flow chart of the manual remote control subprogram, as the buttons that have different functions correspond to different ykval values, therefore, if any control buttons were pressed, fire extinguishing system would complete the appropriate actions. V.
EXPERIMENTAL RESULTS
After completing circuit connection and software downloading, intelligent fire extinguishing system was debugged in the field, as shown in Figure 10. It was installed
[1]
[2]
[3] [4]
Xiaoju Yan, Yuxing Dai, Hongyu Wang, “The Design of Device for Automatic Scanning and Automatic Pisitioning Sprinkling Fire Extinguisher in Large Space”, Electrotechnical Application, Vol.25, pp.117-119, March, 16, 2006. Guoliang Hu, Zhong Li, “Design and Key Technology Research into Auto-Targeting Fire Extinguishing System of Interior Large Space”, 2010 International Conference on Electrical and Control Engineering, pp.687-690, June, 26, 2010. Peiren Zhang, Zhijian Zhangˈ“16 Single Chip Microprocessor Theory and Applications”,Beijing: Tsinghua University Press. 2005. Lingyan Wu, Zhenwei Li, Tianjing Wu, “Design of the Fire Fight Motor Car Based on SPCE061A”, Instrumentation Technology, Vol.5, pp6-8, February, 2009.
