CN201698557U - Air pipe smog sensing fire detector - Google Patents
Air pipe smog sensing fire detector Download PDFInfo
- Publication number
- CN201698557U CN201698557U CN 200920288473 CN200920288473U CN201698557U CN 201698557 U CN201698557 U CN 201698557U CN 200920288473 CN200920288473 CN 200920288473 CN 200920288473 U CN200920288473 U CN 200920288473U CN 201698557 U CN201698557 U CN 201698557U
- Authority
- CN
- China
- Prior art keywords
- circuit
- pin
- signal
- air
- flow
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Fee Related
Links
Images
Abstract
The utility model relates to an air pipe smog sensing fire detector and belongs to the technical field of fire detection. The detector structurally comprises a housing, an airflow sampling pipe, an airflow exhaust pipe, a smog optical detection chamber, an infrared light electric detection circuit, a low impedance signal sampling and amplifying circuit, a signal processing circuit, a time-delay fault signaling output circuit, a signal output and display circuit, and a power switching circuit. The utility model has the advantages that the distinguish and recognition capability of the detector to interference signals can be enhanced, correspondingly, false alarm rate and miss alarm rate of the fire signals are reduced, airflow movability in the airflow detection chamber is guaranteed, the influence of a circumferential flow area is reduced, and the flow field near the smog optical detection chamber is uniform.
Description
Technical field
The utility model belongs to the fire detection technology field, particularly a kind of wind pipe smoke-sensing fire detector.
Background technology
Airduct in the heating ventilation air-conditioning system of building has been formed a complicated pipeline system, is mainly used in and air is carried expeditiously by flow and is distributed, and is a most important ingredient in the heating ventilation air-conditioning system engineering in the building.Yet when fire took place, smog, toxic gas and flame might be propagated along airduct, thereby caused bigger fire, and the airduct detection can be arranged on main ajutage inside and be used for surveying the fault that air-conditioning system itself takes place, and for example blower fan is overheated; Also can be arranged on and be used for surveying the whether breaking out of fire of this room in the room return air duct; Can also be arranged in the air-line system near all kinds of air-valves, the action of control air-valve prevents that fire from propagating by air-line system.In addition, can be used for protecting important equipment, for example the ventilation of mass computing machine host and exhaust airduct.By geocoding and signal transmission, constitute an ingredient of building fire automatic alarm system, realize the fire early detection and the warning of whole building.
The common point type fire detector of external early stage use is installed in and carries out detection in the airduct, but influence owing to factors such as restriction that is subjected to technical merit and technological level and the inner dusts of airduct, relatively poor to the inhibition ability of environmental interference in actual applications, be easy to generate false alarm, and difficult in maintenance, thereby be difficult to satisfy the requirement that early detection is reported to the police.Along with the development of technology, the smoke fire detector of airduct outer wall has appearred being installed in.This detector is installed in common spot-type smoke detector in the airtight box, and box connects sample smog in the airduct of two straight tubes that stretch into airduct inside, thereby realizes purpose that the smog of airduct inside is surveyed.Because everywhere wind speed difference in the heating ventilation air-conditioning system airduct, variation range is bigger in the practical application, so this class detector is difficult to adapt to large-scale wind speed and changes, and has the alert problem of failing to report.On the other hand, have the air of dust, water smoke and heating in the airduct, common spot-type smoke detector is difficult to itself and smoke particle are distinguished, and therefore exists false alarm phenomenon, the problem of this two aspect to restrict the widespread adoption of this class fire detector.
Summary of the invention
Deficiency at the prior art existence, the utility model provides a kind of wind pipe smoke-sensing fire detector, by research to smoke particle feature and interfering noise signal feature, improving the resolution recognition capability of detector, thereby correspondingly reduce the rate of false alarm of fire information and avoid failing to report undesired signal.
The technical solution of the utility model is achieved in that its structure of the utility model detector comprises shell, air-flow sampling pipe, air-flow gas outlet, smog optical detection chamber, infrared electro detection circuit, Low ESR signal sampling amplifying circuit, signal processing circuit, time-delay fault-signal output circuit, signal output and display circuit and power-switching circuit.
The connection of this detector is: a left side on the shell; right both sides are divided into airtight air-flow detection cavity and control circuit chamber; air-flow sampling pipe and air-flow gas outlet stretch into the airduct that needs the air-flow sampling and are fixed on this probe body; air-flow sampling pipe and air-flow gas outlet just sampling air flow are introduced the air-flow detection cavity; smog optical detection chamber is fixed in the air-flow detection cavity; the infrared electro detection circuit; Low ESR signal sampling amplifying circuit; signal processing circuit; time-delay fault-signal output circuit; signal output and display circuit and power-switching circuit are installed in the control circuit chamber; infrared electro detection circuit wherein; Low ESR signal sampling amplifying circuit; signal processing circuit; time-delay fault-signal output circuit links to each other successively with signal output and display circuit; utilize the infrared electro detection circuit that the sampling air flow that passes through is detected; the detectable signal of infrared electro detection circuit output is sent into signal processing circuit after filtering is amplified through Low ESR signal sampling amplifying circuit; signal processing circuit is carried out the A/D conversion to the detectable signal after amplifying; sampling and Data Management Analysis are exported judged result at last; time-delay fault-signal output circuit is exported passive contact signal according to judged result; and comprehensively other failure messages will report to the police and fault-signal show; if cover comes off on the shell; time-delay fault-signal output circuit can be delayed time fault-signal 6.5 minutes and be exported and show; power-switching circuit then is responsible for the 24V fire-fighting power supply is converted to the 5V power supply that detector need use, and is isolated and protect.
Wherein said smog optical detection chamber is a cylindrical structure, on, bottom surface is rounded, comprise infrared-emitting diode, infrared receiving diode, vane type shading window and shading fair water fin, smog optical detection chamber bottom surface is fixed in the air-flow detection cavity in airduct probe body left side, between air-flow sampling pipe and gas outlet, sampling air flow is from smog optical detection chamber, horizontal flow mistake between bottom surface, the left and right sides is provided with one and two shading fair water fins respectively on the direction of the smog optical detection chamber of flowing through along sampling air flow, the shading fair water fin is fixed on the bottom surface of smog optical detection chamber, its length and the middle open area of reserving, comprise that not block the below probing light of infrared-emitting diode and infrared receiving diode is as the criterion, infrared-emitting diode and infrared receiving diode are fixed on the below of smog optical detection chamber bottom surface inner periphery up-sampling air flow direction, the axial angle of power valve and receiving tube is 42 °, constitute back scattering smoke detection angle, on the inner periphery of bottom surface, smog optical detection chamber, the shading window of other even distribution vane type except the zone that infrared-emitting diode and infrared receiving diode occupy, each the shading window blade opening that is in the shape of the letter V.
Smog optical detection chamber one-piece construction both guaranteed that smog optical detection chamber was not subjected to extraneous light to influence the formation optical dark room, can make again sampling air flow smoothly orientation pass through, guaranteed that air-flow surveys the hydrodynamic characteristic of cavity integral body.Wherein, V font blade shading window has played the effect of steering current when covering extraneous light; Quantity asymmetric shading fair water fin in the left and right sides in the smog optical detection chamber in the reflection ray in blocking detecting chamber, has promoted air-flow in the indoor directed flow of smog optical detection, has alleviated the hysteretic phenomenon of low speed sampling air flow; Infrared-emitting diode and infrared receiving diode are fixed on a side of smog optical detection chamber, enough become back scattering smoke detection angle, can increase effective space exploration, be convenient to the sampling air flow that flows is surveyed, can strengthen detectivity and sensitivity again at the characteristics that the smoke particle particle diameter is bigger in the airduct to big particle diameter particle.
Described infrared electro detection circuit network port Pulse is the control wave of control single chip computer output in the signal processing circuit, R1 and R2 series connection are attempted by between control wave Pulse and the circuit ground, play the dividing potential drop effect, control signal after the dividing potential drop inserts the output of the gate leve control Q1 of field effect transistor Q1, the drain electrode of field effect transistor Q1 is connected on the power Vcc, source electrode is connected on the positive pole of infrared electro emitting diode D1, and the negative pole of infrared electro emitting diode D1 is received circuit on the ground by current-limiting resistance R3.As control wave Pulse when being high, the Q1 conducting also is the D1 power supply, and D1 works, and sends Infrared; And when control wave Pulse when low, Q1 turn-offs, D1 does not work.The positive pole of electrochemical capacitor C1 and negative pole are connected on power Vcc and circuit ground respectively, and close on Q1 and D1 setting on circuit board, can play the effect of afterflow and protection when the Q1 turn-on and turn-off.Wherein, control wave Pulse dutycycle is 1: 20, can play the effect that prolongs infrared-emitting diode and infrared receiving diode mission life and its detection sensitivity of protection.
According to the photodiode short-circuit current is that photogenerated current and intensity of illumination are linear proportional relationship and dynamic range than the big a lot of characteristics of photoproduction electromotive force, D2 places photronic duty with the infrared electro reception diode, be infrared electro reception diode D2 just, negative pole directly as current signal just, negative output is in Low ESR signal sampling amplifying circuit, and the negative pole of infrared electro reception diode D2 is received resistance R 5 and R7 go up to raise the current potential of infrared electro reception diode D2 output signal, and played the effect of filtering interfering, wherein R5 and R7 are connected in power Vcc and the circuit ground, played the effect of dividing potential drop, C5 strobes.
Described Low ESR signal sampling amplifying circuit is divided into front and back stages: amplifier unit U2A among the amplifier U2 and R4, C2 has constituted prime I/V current sampling amplifying circuit, the pulsed current signal I+ of infrared electro detection circuit output, I-receives 2 pin and 3 pin of amplifier U2A respectively, utilize amplifier just, negative pole can reduce the output resistance of sampling amplifying circuit greatly as the input end of pulsed current signal, assurance is to the sampling and the amplification of infrared electro detection circuit mid-infrared light electricity reception diode D2 Weak current output signal, R4, C2 also is connected between 2 pin and 1 pin of amplifier U2A, pulsed current signal transfers pulse voltage signal to after taking a sample through R4, and be amplified in the 1 pin output of U2A through amplifier U2A and R4, C2 strobes, 4 pin of U2 and 8 pin are received between power Vcc and the circuit ground, in order to give amplifier U2 power supply; Another amplifier unit U2B and C3 among the amplifier U2, C4, R6 forms relatively device of alternating voltage, the pulse voltage signal of prime output is received on 5 pin of U2B by 1 pin of U2A, as the relatively positive pole input of device of alternating voltage, R6 and C4 series connection, be connected between 6 pin of 3 pin of U2A and U2B, as relatively its negative pole input of alternating voltage, and 6 pin of U2B are received on the network port S2, S2 receives and controls the relatively duty of device of alternating voltage on the control single chip computer in the signal processing circuit, R6 and C4 play isolated direct current signal here and charging is compared device negative pole input voltage to raise alternating voltage, be linked on the network port S1 through 7 pin of alternating voltage comparison device voltage signal processed by U2B, be linked into again on the control single chip computer of signal processing circuit, carry out A/D sampling and data processing, C3 receives between 6 pin of U2B and 7 pin and plays isolated direct current signal, the effect of gating AC signal.In this circuit, select for use the two unit of OP2340PA amplifier as amplifier, its conversion of signals speed (slew rate) is fast, be 6V/ μ s, and noise is low, is 0.0007%, and adopted input and output to be rail-to-rail method, strengthened the AC signal processing power.
Described time-delay fault-signal output circuit utilizes the impermeability of coming off of covering on the step switch S2 monitoring arrangement shell and air-flow detection cavity body, and utilize the time-delay fault-signal output circuit that constitutes by C9, R14, C10, Q3 and U4 that cover on the shell is come off or loosening fault-signal time-delay output in 6.5 minutes, can make things convenient for daily the uncap maintenance and the maintenance of equipment, improve the applicability of detector engineering practical application.Cover in the release failure delay circuit on the shell, normally closed point 2 pin and 3 pin of step switch S2 are connected on respectively on resistance R 13 and the R10, the other end connection circuit ground of R13, another termination power Vcc of R10, electrochemical capacitor C7 receives respectively between R10 and the circuit ground, play the effect of afterflow and buffering, 2 pin of step switch S2 are received 2 pin of timer U4, trigger voltage as timer, resistance R 14 and electrochemical capacitor C10 series connection are received between power Vcc and the circuit ground, and the positive pole of C10 is received on 6 pin of timer U4, with thinking that timer provides threshold voltage and determined the timing length of timer U4, the positive pole that 7 pin of timer U4 are received C10 is simultaneously controlled the discharging and recharging of electrochemical capacitor C10, and the base stage of positive-negative-positive triode Q3 is received on 2 pin of timer U4, emitter is received on the positive pole of C10, be used for controlling the discharge loop of C10 the collector connection circuit.Two of capacitor C 9 terminates between U4 and the circuit ground, carries out filtering.8 pin of timer U4 and 1 pin connect power Vcc and circuit ground respectively, and to provide operating voltage to U4,4 pin of timer U4 are that reseting controling end connects power Vcc.Timer 3 pin will be delayed time fault-signal by network port Trb-R, output to signal output and display circuit.
When outer casing upper cover fastens, step switch S2 action, its 2 pin is connected with 1 pin, 2 pin of timer U4 are by R10 ground connection, and trigger voltage is less than 1/3Vcc, and 3 pin of timer U4 are exported high level, because fault-signal is for effectively low, the airduct detector is shown as unfaulty conditions.In case cover comes off or loosening on the probe body, operating switch S2 resets, its 2 pin is connected with 3 pin, R10 and R13 are connected between power Vcc and the circuit ground, 2 pin of timer U4 are received R10 and R13 junction, trigger voltage is 10/11Vcc, greater than 1/3Vcc, electrochemical capacitor C10 begins charging, during greater than 2/3Vcc, the threshold voltage of 6 pin of timer U4 is greater than 2/3Vcc up to electrochemical capacitor C10 cathode voltage, and the output of 3 pin of timer U4 becomes low level, because fault-signal is for effectively low, this moment, detector just transferred malfunction to by unfaulty conditions.
The course of work of the present utility model: the airduct fire detector is mounted in the smoke fire detector of the employing sampling pipe mode of airduct outside.
Panel detector structure is made up of housing and two hollow sampling pipes, and sampling pipe stretches into tested airduct inside, perpendicular to airflow direction.Stagnation pressure tube has row's thieff hatch on the windward side, outer likeness in form flute, after air communication over-sampling hole is collected into stagnation pressure tube, air-flow is because differential pressure action flows into housing, flow out from static tube, in this process the smog optical detection chamber of flowing through, by smog is to the scattering process of Infrared in infrared-emitting diode in the smog optical detection chamber and the infrared receiving diode perception air-flow, whether the air-flow that the airduct smoke detector just can detect in the airduct exists smog.In case detect the existence of smog, the airduct detector is just lighted alarm lamp, and presses logic of propositions interlock relevant device (blower fan, valve etc.) action.
Wind pipe smoke-sensing fire detector generally can be arranged on main ajutage inside and be used for surveying the fault that air-conditioning system itself takes place, and for example blower fan is overheated; Also can be arranged on and be used for surveying the whether breaking out of fire of this room in the room return air duct; Can also be arranged in the air-line system near all kinds of air-valves, the action of control air-valve prevents that fire from propagating by air-line system.In addition, can be used for protecting important equipment, for example the ventilation of mass computing machine host and exhaust airduct.By geocoding and signal transmission, constitute an ingredient of building fire automatic alarm system, realize the fire early detection and the warning of whole building.Particularly in the gymnasium of domestic a large amount of constructions at present, large space class building such as exhibition center is more suitable.
Advantage of the present utility model: the utility model detector has guaranteed the influence of the mobile and minimizing circulating-area of air-flow in the air-flow detection cavity, makes near the even flow field in smog optical detection chamber.Guarantee in the airduct under the different wind conditions smog optical detection indoor qualified sample gas is arranged and keeps detection sensitivity be consistent.Smog optical detection chamber, adopted the shading window of vane type and infrared-emitting diode and infrared receiving diode have been fixed on a side of smog optical detection chamber, sampling air flow is passed through smoothly, guaranteed the hydrodynamic characteristic of air-flow detection cavity integral body, can give in the optical detection chamber again and reserve sufficient space exploration, thereby realize the reliable detection of smog in the flowing gas to smoke detection.The airduct flue gas characteristic that obtains according to experimental study, select the infrared tube that transmits and receives of specific peaks wave band for use, and form backward scattered smoke detection mode, to be operated in the output current of the photosensitive reception diode under the photoelectric cell state as smoke detection signal, utilize low output impedance I/V change-over circuit to carry out the reception and the amplification of signal, make the dynamic range of smoke transducer bigger, linear better, strengthened of detectivity and the sensitivity of the utility model detector to big particle diameter smoke particle more in the airduct.What built-in step switch covered on the monitoring arrangement shell comes off, the signal lag output circuit, cover release failure information can be delayed time to be exported in 6.5 minutes, the utility model had both guaranteed air-flow is surveyed the surveillance coverage that cover comes off on cavity impermeability and the shell, also make things convenient for simultaneously daily the uncap maintenance and the maintenance of equipment, improved the actual applicability of engineering of the utility model detector.
Description of drawings
Fig. 1 is a kind of complete machine structure schematic diagram of wind pipe smoke-sensing fire detector;
Fig. 2 is a kind of wind pipe smoke-sensing fire detector air-flow sampling and circulating function synoptic diagram;
Fig. 3 is a kind of systematic functional structrue block diagram of wind pipe smoke-sensing fire detector;
Fig. 4 is the structure principle chart of smog optical detection chamber in a kind of wind pipe smoke-sensing fire detector;
Fig. 5 is a kind of detector infrared electro detection circuit electrical schematic diagram;
Fig. 6 is a kind of detector signal Low ESR signal sampling amplifying circuit electrical schematic diagram;
Fig. 7 is a kind of detector signal treatment circuit electricity reason figure;
Fig. 8 is a kind of detector power-switching circuit electrical schematic diagram;
Fig. 9 is a kind of detector time-delay fault-signal output circuit electrical schematic diagram;
Figure 10 is a kind of survey device signal output and display circuit electrical schematic diagram;
Figure 11 is a kind of wind pipe smoke-sensing fire detector detection schematic diagram.
Among the figure: 1 air-flow sampling pipe, 2 air-flow gas outlets, 3 air-flow detection cavities, smog optical detection chambers 4,5 control circuit chambeies, 6 airducts, 7 infrared-emitting diodes, 8 infrared receiving diodes, 9 vane type shading windows, 10 shading fair water fins.
Embodiment
The detailed structure of a kind of wind pipe smoke-sensing fire detector of the utility model is illustrated in conjunction with the embodiments.
This detector as shown in Figure 1, comprise shell, air-flow sampling pipe 1, air-flow gas outlet 2, smog optical detection chamber 3, infrared electro detection circuit as shown in Figure 5, Low ESR signal sampling amplifying circuit as shown in Figure 6, signal processing circuit as shown in Figure 7, time-delay fault-signal output circuit as shown in Figure 9, signal output and display circuit as shown in figure 10 with power-switching circuit as shown in Figure 8.
The connection of this detector is: a left side on the shell; right both sides are divided into airtight air-flow detection cavity 3 and control circuit chamber 5; air-flow sampling pipe 1 and air-flow gas outlet 2 stretch into the pipeline that needs the air-flow sampling and are fixed on this probe body; air-flow sampling pipe 1 and air-flow gas outlet 2 are introduced air-flow detection cavity 3 with sampling air flow; smog optical detection chamber 4 is fixed in the air-flow detection cavity 3; the infrared electro detection circuit; Low ESR signal sampling amplifying circuit; signal processing circuit; time-delay fault-signal output circuit; signal output and display circuit and power-switching circuit are installed in the control circuit chamber; as shown in Figure 3; infrared electro detection circuit wherein; Low ESR signal sampling amplifying circuit; signal processing circuit; signal output and display circuit link to each other successively with time-delay fault-signal output circuit; utilize the infrared electro detection circuit that the sampling air flow that passes through is detected; the detectable signal of infrared electro detection circuit output is sent into signal processing circuit after filtering is amplified through Low ESR signal sampling amplifying circuit; signal processing circuit is carried out the A/D conversion to the detectable signal after amplifying; sampling and Data Management Analysis are exported judged result at last; time-delay fault-signal output circuit is exported passive contact signal according to judged result; and comprehensively other failure messages will report to the police and fault-signal show; if cover comes off on the shell; time-delay fault-signal output circuit can be delayed time fault-signal 6.5 minutes and be exported and show; power-switching circuit then is responsible for the 24V fire-fighting power supply is converted to the 5V power supply that detector need use, and is isolated and protect.
Near the only guaranteed smog optical detection chamber even flow field, could guarantee under the interior different wind conditions of airduct the smog optical detection indoor qualified sample gas is arranged and keeps detection sensitivity be consistent.The utility model device adopts the Fluid Mechanics Computation method that complete machine structure is optimized.As shown in Figure 2, detector mode as shown is installed on tested airduct outer wall, and air-flow is entered in the sampling pipe by thieff hatch, and the smog optical detection chamber of flowing through is expelled back in the airduct through gas outlet.Wherein, the diameter of thieff hatch and distribution, air-flow sampling pipe stretch into the interior space dimension of length, air stream decetor of air-flow detection cavity and gas outlet length etc. and all pass through detailed calculating and emulation, guaranteed under the different wind conditions smog optical detection indoor qualified sample gas is arranged and keeps detection sensitivity be consistent.
Smog optical detection chamber is cylindrical structure as shown in Figure 4, and upper and lower bottom surface is rounded, and diameter is 60.2mm; Interior high 28.3mm, its horizontal profile structure figure as shown in Figure 4, its bottom surface is fixed in the air-flow detection cavity in airduct probe body left side, between air-flow sampling pipe and air-flow gas outlet, sampling air flow is from smog optical detection chamber, horizontal flow mistake between bottom surface, the left and right sides is provided with one and two shading fair water fins respectively on the direction of the smog optical detection chamber of flowing through along sampling air flow, the shading fair water fin is fixed on the bottom surface of smog optical detection chamber, highly be 25.3mm, its length and the middle open area of reserving, be as the criterion with the probing light that does not block below infrared-emitting diode and infrared receiving diode, infrared-emitting diode and infrared receiving diode are fixed on the below of the indoor circumference bottom surface of smog optical detection up-sampling air flow direction, the axial angle of power valve and receiving tube is 42 °, constituted back scattering smoke detection angle, on the circumference of bottom surface, smog optical detection chamber, the shading window of other even distribution vane type except the zone that infrared-emitting diode and infrared receiving diode occupy, each shading window blade opening that is in the shape of the letter V, leaf angle is 87 °, the spacing at blade center is 1/3.1 of an every width of blade, promptly 3.27 centimetres.
The infrared electro detection circuit as shown in Figure 5, network port Pulse is the control wave of control single chip computer output in the signal processing circuit, R1 and R2 series connection are attempted by between control wave Pulse and the circuit ground, carry out dividing potential drop, control signal after the dividing potential drop inserts the output of the gate leve control Q1 of field effect transistor Q1, the drain electrode of field effect transistor Q1 is connected on the power supply on the Vcc, source electrode is connected on the positive pole of infrared electro emitting diode D1, and the negative pole of infrared electro emitting diode D1 is received circuit on the ground by current-limiting resistance R3.As control wave Pulse when being high, the Q1 conducting also is the D1 power supply, and D1 works, and sends Infrared; And when control wave Pulse when low, Q1 turn-offs, D1 does not work.The positive pole of electrochemical capacitor C1 and negative pole are connected on power Vcc and circuit ground respectively, and close on Q1 and D1 setting on circuit board, can play the effect of afterflow and protection when the Q1 turn-on and turn-off.Here, control wave Pulse dutycycle is 1: 20, has played the effect that prolongs infrared-emitting diode and infrared receiving diode mission life and its detection sensitivity of protection like this.
Be linear proportional relationship and dynamic range than the big a lot of characteristics of photoproduction electromotive force according to photodiode short-circuit current (photogenerated current) and intensity of illumination, the utility model places photronic duty with infrared electro reception diode D2, be infrared electro reception diode D2 just, negative pole directly as current signal just, negative output is in Low ESR signal sampling amplifying circuit, and the negative pole of infrared electro reception diode D2 is received resistance R 5 and R7 go up to raise the current potential of infrared electro reception diode D2 output signal, played the effect of filtering interfering, wherein R5 and R7 are connected in power Vcc and the circuit ground, played the effect of dividing potential drop, C5 strobes.
Signal Low ESR signal sampling amplifying circuit as shown in Figure 6, be divided into front and back stages: amplifier unit U2A among the amplifier U2 and R4, C2 has constituted prime I/V current sampling amplifying circuit, the pulsed current signal I+ of infrared electro detection circuit output, I-receives 2 pin and 3 pin of amplifier U2A respectively, here just utilize amplifier, negative pole can reduce the output resistance of sampling amplifying circuit greatly as the input end of pulsed current signal, assurance is to the sampling and the amplification of infrared electro detection circuit mid-infrared light electricity reception diode D2 Weak current output signal, R4, C2 also is connected between 2 pin and 1 pin of amplifier U2A, pulsed current signal transfers pulse voltage signal to after taking a sample through R4, and be amplified in the 1 pin output of U2A through amplifier U2A and R4, here C2 strobes, 4 pin of U2 and 8 pin are received between power Vcc and the circuit ground, in order to give amplifier U2 power supply; Another amplifier unit U2B and C3 among the amplifier U2, C4, R6 forms relatively device of alternating voltage, the pulse voltage signal of prime output is received on 5 pin of U2B by 1 pin of U2A, as the relatively positive pole input of device of alternating voltage, R6 and C4 series connection, be connected between 6 pin of 3 pin of U2A and U2B, as relatively its negative pole input of alternating voltage, and 6 pin of U2B are received on the network port S2, S2 receives and controls the relatively duty of device of alternating voltage on the control single chip computer in the signal processing circuit, R6 and C4 play isolated direct current signal here and charging is compared device negative pole input voltage to raise alternating voltage, be linked on the network port S1 through 7 pin of alternating voltage comparison device voltage signal processed by U2B, be linked into again on the control single chip computer of signal processing circuit, carry out A/D sampling and data processing, C3 receives between 6 pin of U2B and 7 pin and plays isolated direct current signal, the effect of gating AC signal.In this circuit, select for use the two unit of OP2340PA amplifier as amplifier, its conversion of signals speed (slew rate) is fast, be 6V/ μ s, and noise is low, is 0.0007%, and adopts input and output to be rail-to-rail method, has strengthened the AC signal processing power.
This circuit utilizes the impermeability of coming off of covering on the step switch S2 monitoring arrangement shell and air-flow detection cavity body, and utilize the time-delay fault-signal output circuit that constitutes by C9, R14, C10, Q3 and U4 that cover on the shell is come off or loosening fault-signal time-delay output in 6.5 minutes, both make things convenient for daily the uncap maintenance and the maintenance of equipment, improved the applicability of detector engineering practical application again
Time-delay fault-signal output circuit as shown in Figure 9, normally closed point 2 pin and 3 pin of step switch S2 are connected on respectively on resistance R 13 and the R10, the other end connection circuit ground of R13, another termination power Vcc of R10, electrochemical capacitor C7 receives respectively between R10 and the circuit ground, play the effect of afterflow and buffering, 2 pin of step switch S2 are received 2 pin of timer U4, trigger voltage as timer, resistance R 14 and electrochemical capacitor C10 series connection are received between power Vcc and the circuit ground, and the positive pole of C10 is received on 6 pin of timer U4, with thinking that timer provides threshold voltage and determined the timing length of timer U4, the positive pole that 7 pin of timer U4 are received C10 is simultaneously controlled the discharging and recharging of electrochemical capacitor C10, and the base stage of positive-negative-positive triode Q3 is received on 2 pin of timer U4, emitter is received on the positive pole of C10, be used for controlling the discharge loop of C10 the collector connection circuit.Two of capacitor C 9 terminates between U4 and the circuit ground, strobes.8 pin of timer U4 and 1 pin connect power Vcc and circuit ground respectively, and to provide operating voltage to U4,4 pin of timer U4 are that reseting controling end connects power Vcc.Timer 3 pin will be delayed time fault-signal by network port Trb-R, output to signal output and display circuit.
In this circuit, timer is selected timing chip ICM7555 for use, and it adopts CMOS technology, low in energy consumption, timing accuracy is high, and on steering logic, the control priority of trigger voltage is higher than limit door piezoelectricity, can realize the recovery of fault-signal after cover fastens on the shell like this, its truth table is as follows:
| Reset signal (4 pin) | Trigger voltage (2 pin) | Threshold voltage (6 pin) | Output signal (3 pin) | Discharge electric control end (7 pin) |
| Low level | -? | -? | Low level | Open |
| High level | ＞1/3Vcc? | ＞2/3Vcc? | Low level | Open |
| High level | ＞1/3Vcc? | ＜2/3Vcc? | Keep | Keep |
| High level | ＜1/3Vcc? | -? | High level | Close |
When outer casing upper cover fastens, step switch S2 action, its 2 pin is connected with 1 pin, 2 pin of timer U4 are by R10 ground connection, and trigger voltage is less than 1/3Vcc, and 3 pin of timer U4 are exported high level, because fault-signal is for effectively low, so the airduct detector is shown as unfaulty conditions.In case cover comes off or loosening on the probe body, operating switch S2 resets, its 2 pin is connected with 3 pin, R10 and R13 are connected between power Vcc and the circuit ground, 2 pin of timer U4 are received R10 and R13 junction, trigger voltage is 10/11Vcc, greater than 1/3Vcc, electrochemical capacitor C10 begins charging, during greater than 2/3Vcc, the threshold voltage of 6 pin of timer U4 is greater than 2/3Vcc up to electrochemical capacitor C10 cathode voltage, and the output of 3 pin of timer U4 becomes low level, because fault-signal is for effectively low, this moment, detector just transferred malfunction to by unfaulty conditions.
Determining of timing length:
Timing length=η RC,
η is a correction coefficient in the formula, gets 1.18 here, and R and C are divided into timing resistor and electric capacity, i.e. R14 in this circuit and C10.So when choosing R14 is 1.5M Ω, when C10 was 220 μ F, timing length was 389.4 seconds, was about 6.5 minutes.
The course of work of airduct detection: the airduct fire detector is mounted in the smoke fire detector of the employing sampling pipe mode of airduct outside.Its groundwork process as shown in figure 11.
Panel detector structure is made up of housing and two hollow sampling pipes, and sampling pipe stretches into tested airduct inside, perpendicular to airflow direction.Stagnation pressure tube has row's thieff hatch on the windward side, outer likeness in form flute, after air communication over-sampling hole is collected into stagnation pressure tube, air-flow is because differential pressure action flows into housing, flow out from static tube, in this process the smog optical detection chamber of flowing through, by smog is to the scattering process of Infrared in infrared-emitting diode in the smog optical detection chamber and the infrared receiving diode perception air-flow, whether the air-flow that the airduct smoke detector just can detect in the airduct exists smog.In case detect the existence of smog, the airduct detector is just lighted alarm lamp, and presses logic of propositions interlock relevant device (blower fan, valve etc.) action.
The application of airduct fire detector: wind pipe smoke-sensing fire detector generally can be arranged on main ajutage inside and be used for surveying the fault (for example blower fan is overheated) that air-conditioning system itself takes place; Also can be arranged on and be used for surveying the whether breaking out of fire of this room in the room return air duct; Can also be arranged in the air-line system near all kinds of air-valves, the action of control air-valve prevents that fire from propagating by air-line system.In addition, can be used for protecting important equipment (for example ventilation of mass computing machine host and exhaust airduct) or the like.By geocoding and signal transmission, constitute an ingredient of building fire automatic alarm system, realize the fire early detection and the warning of whole building.Particularly in the gymnasium of domestic a large amount of constructions at present, large space class building such as exhibition center is more suitable.
Claims (5)
1. wind pipe smoke-sensing fire detector, it is characterized in that: this detector comprises shell, air-flow sampling pipe, air-flow gas outlet, smog optical detection chamber, infrared electro detection circuit, Low ESR signal sampling amplifying circuit, signal processing circuit, signal output and display circuit, time-delay fault-signal output circuit and power-switching circuit; The connection of this detector is: a left side on the shell, right both sides are provided with air-flow detection cavity and control circuit chamber, air-flow sampling pipe and air-flow gas outlet stretch into the airduct that needs the air-flow sampling and are fixed on this probe body, air-flow sampling pipe and air-flow gas outlet are introduced the air-flow detection cavity with sampling air flow, smog optical detection chamber is fixed in the air-flow detection cavity, the infrared electro detection circuit, Low ESR signal sampling amplifying circuit, signal processing circuit, signal output and display circuit, time-delay fault-signal output circuit and power-switching circuit are installed in the control circuit chamber, wherein the infrared electro detection circuit, Low ESR signal sampling amplifying circuit, signal processing circuit, signal output and display circuit link to each other successively with time-delay fault-signal output circuit.
2. by the described wind pipe smoke-sensing fire detector of claim 1, it is characterized in that described smog optical detection chamber is a cylindrical structure, on, bottom surface is rounded, comprise infrared-emitting diode, infrared receiving diode, vane type shading window and shading fair water fin, smog optical detection chamber bottom surface is fixed in the air-flow detection cavity in airduct probe body left side, between air-flow sampling pipe and air-flow gas outlet, sampling air flow is from smog optical detection chamber, horizontal flow mistake between bottom surface, the left and right sides is provided with one and two shading fair water fins respectively on the direction of the smog optical detection chamber of flowing through along sampling air flow, the shading fair water fin is fixed on the bottom surface of smog optical detection chamber, its length and the middle open area of reserving, comprise that not block the below probing light of infrared-emitting diode and infrared receiving diode is as the criterion, infrared-emitting diode and infrared receiving diode are fixed on the below of smog optical detection chamber bottom surface inner periphery up-sampling air flow direction, the axial angle of power valve and receiving tube is 42 °, constitute back scattering smoke detection angle, on the inner periphery of bottom surface, smog optical detection chamber, the shading window of other even distribution vane type except the zone that infrared-emitting diode and infrared receiving diode occupy, each the shading window blade opening that is in the shape of the letter V.
3. by the described wind pipe smoke-sensing fire detector of claim 1, the network port Pulse that it is characterized in that described infrared electro detection circuit is the control wave of control single chip computer output in the signal processing circuit, R1 and R2 series connection are attempted by between control wave Pulse and the circuit ground, control signal after the dividing potential drop inserts the output of the gate leve control Q1 of field effect transistor Q1, the drain electrode of field effect transistor Q1 is connected on the power Vcc, source electrode is connected on the positive pole of infrared electro emitting diode D1, the negative pole of infrared electro emitting diode D1 is received circuit on the ground by current-limiting resistance R3, the positive pole of electrochemical capacitor C1 and negative pole are connected on power Vcc and circuit ground respectively, infrared electro reception diode D2 just, negative pole directly as current signal just, negative output is in Low ESR signal sampling amplifying circuit, and the negative pole of infrared electro reception diode D2 received on resistance R 5 and the R7, wherein R5 and R7 are connected in power Vcc and the circuit ground.
4. by the described wind pipe smoke-sensing fire detector of claim 1, it is characterized in that described Low ESR signal sampling amplifying circuit is divided into front and back stages: amplifier unit U2A among the amplifier U2 and R4, C2 has constituted prime I/V current sampling amplifying circuit, the pulsed current signal I+ of infrared electro detection circuit output, I-receives 2 pin and 3 pin of amplifier U2A respectively, R4, C2 also is connected between 2 pin and 1 pin of amplifier U2A, pulsed current signal transfers pulse voltage signal to after taking a sample through R4, and being amplified in the 1 pin output of U2A through amplifier U2A and R4,4 pin of U2 and 8 pin are received between power Vcc and the circuit ground; Another amplifier unit U2B and C3 among the amplifier U2, C4, R6 forms relatively device of alternating voltage, the pulse voltage signal of prime output is received on 5 pin of U2B by 1 pin of U2A, as the relatively positive pole input of device of alternating voltage, R6 and C4 series connection, be connected between 6 pin of 3 pin of U2A and U2B, as relatively its negative pole input of alternating voltage, and 6 pin of U2B are received on the network port S2, S2 receives on the control single chip computer in the signal processing circuit, be linked on the network port S1 through 7 pin of alternating voltage comparison device voltage signal processed by U2B, be linked into again on the control single chip computer of signal processing circuit, carry out A/D sampling and data processing, C3 receives between 6 pin and 7 pin of U2B.
5. by the described wind pipe smoke-sensing fire detector of claim 1, normally closed point 2 pin and 3 pin that it is characterized in that described time-delay fault-signal output circuit step switch S2 are connected on respectively on resistance R 13 and the R10, the other end connection circuit ground of R13, another termination power Vcc of R10, electrochemical capacitor C7 receives respectively between R10 and the circuit ground, 2 pin of step switch S2 are received 2 pin of timer U4, resistance R 14 and electrochemical capacitor C10 series connection are received between power Vcc and the circuit ground, and the positive pole of C10 is received on 6 pin of timer U4,7 pin of timer U4 are received the positive pole of C10 simultaneously, the base stage of positive-negative-positive triode Q3 is received on 2 pin of timer U4, emitter is received on the positive pole of C10, collector connection circuit ground, two of capacitor C 9 terminates between U4 and the circuit ground, 8 pin of timer U4 and 1 pin connect power Vcc and circuit ground respectively, 4 pin of timer U4 are that reseting controling end connects power Vcc, timer 3 pin will be delayed time fault-signal by network port Trb-R, output to signal output and display circuit.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 200920288473 CN201698557U (en) | 2009-12-28 | 2009-12-28 | Air pipe smog sensing fire detector |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 200920288473 CN201698557U (en) | 2009-12-28 | 2009-12-28 | Air pipe smog sensing fire detector |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN201698557U true CN201698557U (en) | 2011-01-05 |
Family
ID=43399803
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN 200920288473 Expired - Fee Related CN201698557U (en) | 2009-12-28 | 2009-12-28 | Air pipe smog sensing fire detector |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN201698557U (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104127968A (en) * | 2014-08-11 | 2014-11-05 | 江苏省钟星消防工程有限公司马鞍山分公司 | Smoke detection alarming and fire fighting system |
| CN105354972A (en) * | 2015-11-30 | 2016-02-24 | 无锡拓能自动化科技有限公司 | Early-stage fire alarming method based on particle measurement |
| CN107516397A (en) * | 2017-09-28 | 2017-12-26 | 深圳市泰和安科技有限公司 | Optical detector of fire smoke |
-
2009
- 2009-12-28 CN CN 200920288473 patent/CN201698557U/en not_active Expired - Fee Related
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104127968A (en) * | 2014-08-11 | 2014-11-05 | 江苏省钟星消防工程有限公司马鞍山分公司 | Smoke detection alarming and fire fighting system |
| CN105354972A (en) * | 2015-11-30 | 2016-02-24 | 无锡拓能自动化科技有限公司 | Early-stage fire alarming method based on particle measurement |
| CN107516397A (en) * | 2017-09-28 | 2017-12-26 | 深圳市泰和安科技有限公司 | Optical detector of fire smoke |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN101763708B (en) | Wind pipe smoke-sensing fire detector | |
| WO2016116024A1 (en) | Point-type active smoke detector with or without gas sampling tube and air sampling system | |
| CN102054322A (en) | Fire sensor and method for detecting fire | |
| CN107477632B (en) | Range hood capable of detecting oil smoke concentration | |
| CN201698557U (en) | Air pipe smog sensing fire detector | |
| CN103093574A (en) | Active inspiration type point type photoelectric smoke detector | |
| CN110009863A (en) | A kind of vertical double light path smoke detection labyrinth and its detection method | |
| CN203759818U (en) | Fire detection device for cargo bay of air-breathing airplane based on combined detection technology | |
| CN205621213U (en) | Fire detector | |
| CN203025892U (en) | Active aspiration point type photoelectric smoke sensing detector | |
| CN106710127A (en) | Independent type photoelectric smoke sensing fire alarm device and working method | |
| CN207300816U (en) | A kind of particulate matter sensors based on pulsed laser deposition | |
| CN213121831U (en) | On-line odor monitoring system device | |
| CN108648407A (en) | A kind of fire detecting arrangement | |
| CN110533869A (en) | A kind of fire behavior prior-warning device suitable for parking stall | |
| CN206421541U (en) | A kind of free-standing photoelectric smoke alarm | |
| CN216525792U (en) | Home environment monitoring circuit, detection device and robot | |
| CN204286997U (en) | A kind of dust testing circuit based on GP2Y1010AU0F module | |
| CN211452614U (en) | Infrared flame detector and circuit thereof | |
| CN107240217A (en) | A kind of solar energy gridding forestry fire monitoring early warning system | |
| CN2722244Y (en) | Air absorbing style smoke and gas mixed fire detector | |
| CN205957990U (en) | Miniature air flow sensor | |
| CN114076819A (en) | Home environment monitoring circuit, detection device and robot | |
| CN205788626U (en) | Subway suction type smoke detector | |
| CN207302271U (en) | A kind of solar energy gridding forestry fire monitoring early warning system |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| C17 | Cessation of patent right | ||
| CF01 | Termination of patent right due to non-payment of annual fee |
Granted publication date: 20110105 Termination date: 20111228 |