CN2831057Y - Airflow detector - Google Patents
Airflow detector Download PDFInfo
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- CN2831057Y CN2831057Y CN 200520091982 CN200520091982U CN2831057Y CN 2831057 Y CN2831057 Y CN 2831057Y CN 200520091982 CN200520091982 CN 200520091982 CN 200520091982 U CN200520091982 U CN 200520091982U CN 2831057 Y CN2831057 Y CN 2831057Y
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Abstract
The utility model relates to an airflow flow detector, which belongs to the technical field of a fire detection alarm. Therefore, an airflow sensing plate is buckled and arranged on the air inlet end of a flow measuring pipe in a sliding mode through an installing groove which is positioned on a center line of the flow measuring pipe. An airflow flow sensor and an airflow temperature sensor are symmetrically welded on one side the airflow sensing plate near an air inlet of the flow measuring pipe, and the sensing surfaces of the airflow flow sensor and the airflow temperature sensor are arranged on the top end of the airflow sensing plate and are perpendicular to the plate surface of the airflow sensing plate to face the airflow inlet direction. The air outlet end of the flow measuring pipe is provided with a cross and vertical flow guiding plate which forms a plate structural shape, and a cross central line of the flow guiding plate and an axle wire of the flow measuring pipe are coincident. When the air inlet of an air suction device is sealed, the unique structure of the airflow flow guiding plate of the utility model can repress that the working pressure of the air suction device can generate the non air inlet turbulence in a balanced mode and the sensor can realize the accurate measurement of the zero air inlet flow.
Description
Technical field
The utility model belongs to the fire detecting and alarm technical field, particularly a kind of attraction type detector detection device of airflow flow.
Background technology
Along with China's development of economic construction, some play special place (as computing center, picture and text archives information center, post and telecommunications hinge, integrated circuit workshop, nuclear power station, large-scale modernized dispatching control center, intelligent building control center, modern medical service mechanism etc.) the security against fire demand of most important effect in national economy and social life urgent day by day.Since its inner various electrical equipment high concentration and long-term work operation, thus there is more fire hidden danger, in case breaking out of fire will cause great economic loss to country, bring significant impact to society.In view of the importance and the singularity in these places, the super early fire detection warning problem in these places has become one of emphasis of security against fire, causes people's very big concern.
At present, the smoke detector of the general type of these place widespread uses, the sensing chamber that this type detector needs smog to be diffused into detector can implement detection alarm, and the protection area is little, and the response time is long; Be subjected to the not restriction of high factor of detection sensitivity, for the utmost point early detection scarce capacity of fire, the affirmation that belongs to fire is basically surveyed, and is difficult to play the forecast and the fire prevention effect of fire, can not satisfy the requirement that the super early detection of fire is reported to the police in addition.In order to improve the fire forecast pre-alerting ability of fire detector, developed attraction type high sensitivity smoke detection technology in the world.Attraction type high sensitivity smoke detecting and warning system is a kind of high sensitivity smoke detecting and warning system that adopts the active inspiration detection mode; the gas sample is extracted into the smoke detecting chamber of detector by the sampling pipe network that has thieff hatch at the protected scene that is laid in; can be before fire forms visible smog identifies the potential condition of a fire when not occurring as yet; the implementation phase alarm is satisfied requirement of engineering, highly sensitive super early fire detection warning new and high technology means for those important places provide.Because this type technical products; need the air sample at protected scene be transported to mist detecting device by air-breathing sampling; the breakage of the decline of getter device gettering ability, the on-the-spot sampling pipe network that is laid in or the size of obstruction and efficiently sampling ability and variation will directly influence the detection performance of this type technical products; so require convention according to international technical standards, this type technical products must possess the detection and the fault alarm function of sampling flow.
Present gas flow measurement technology has air flow rate detection methods such as vane type, hot-bulb formula, hot-wire, differential, ultrasonic type, laser-Doppler; Wherein the vane type flow detection relies on air-flow impeller mechanical rotation to measure; Hot-wire adopts two sections sensors arranging along the air current flow aspect; Its middle and upper reaches are heated to 1000 ℃ of high temperature for one section, and the heat that air-flow will this section is taken away, and make the heating of tract sensor, carry out flow measurement by the change in resistance of two sections sensors; Thereby the mode that the heat that the hot-bulb formula adopts air-flow to take away the hot-bulb sensor changes resistance of sensor is carried out flow measurement, and the hot-bulb temperature is not less than 800 ℃ usually; Differential pressure differential by the upstream and downstream air-flow is carried out flow measurement; The ultrasonic Doppler formula is carried out the measurement of flow velocity by hyperacoustic Doppler shift, and then calculates flow; The laser-Doppler formula is carried out fluid-velocity survey by the Doppler shift of laser, and then measures flow.
The little range that detects for attraction type fire detector air flow rate, high resolving power, on a small scale, low consumption, cheaply require for, above measuring method mainly has the following disadvantages, wherein vane type, hot-wire measurement method are fit to the detection with the high velocity air flow, range is big and resolution is lower, and the sensing device volume is very much not easy of integration; Differential method need be at different position setting pressure sensors, guaranteeing enough pressure reduction output signal strengths, and integrated assembling inconvenience, and the micropressure sensor price is more expensive; Ultrasound wave and laser Doppler measuring mode technical sophistication, with high costs; The hot-bulb formula is simple in structure, volume is small and exquisite, but sensor is easy to damage, and does not have the general purpose transducer of standard to supply business procurement, and price is higher.So above air flow rate measuring technique all is not suitable for integrated use in the attraction type fire detector.
Similar with the principle of hot-bulb formula, hot-wire equivalent thermal type air flow flow detector, the utility model also adopts air-flow to take away the heat of sensor, thereby causes that sensor temperature decline takes place causes the resistance of sensor parameter to change, and carries out the measurement of flow; Different is the sensor that the utility model has adopted gas flow temperature compensation, the measuring-signal of the air flow rate that makes, be not subjected to influence that the air-flow self-temperature changes and only relevant with air flow rate, avoided other calorimetric air flow rate detection method rely on sufficiently high working temperature evade the air-flow self-temperature change power consumption that the method for measuring influence is brought greatly, complex manufacturing technology, problem of ultra-high price.The utility model has designed unique air flow rate deflector structure and unique sensor installation assembly structure simultaneously, has really realized the detection to outside charge air flow amount, has satisfied the monitoring and the warning of attraction type fire detector airshed.
The utility model device provides a kind of novelty, special-purpose attraction type fire detector air flow rate detection technique, its critical component adopts the general purpose transducer and the components and parts of industrial standard, the exchange performance of device is fabulous, and volume is small and exquisite, with low cost, and assembling is simple; Range, resolution and temperature stability all satisfy the requirement of attraction type fire detector, have reached good result of use.
The utility model content
At the deficiencies in the prior art, the utility model provides a kind of air flow rate measurement mechanism, and this device comprises air flow rate sensor, air flow temperature sensor, air-flow sensing plate, fair water fin and flow tube.Wherein the mounting groove cunning of the center line of air-flow sensing plate by being positioned at flow tube is closed the air intake opening end that is installed in flow tube, air flow rate sensor, air flow temperature sensor are symmetrically welded at the side of air-flow sensing plate near the flow tube air intake opening, make the sensitive face of air flow rate sensor, air flow temperature sensor on the top of air-flow sensing plate, and make the sensitive face of air flow rate sensor, air flow temperature sensor vertical with the plate face of air-flow sensing plate, meet to the air-flow airintake direction; Be provided with the fair water fin of cross vertical panel planform in the outlet side of flow tube, the cross centre line of fair water fin overlaps with the axis of flow tube; Fair water fin can close installation by mounting groove and flow tube cunning, also fair water fin and flow tube can be passed through the integrated realization of mould.
The superiority of this structure is that the heat that can make air-flow take away the air flow rate sensor maximizes, thereby make initial flow signal the strongest, make the be not bullied heat radiation of flow rate sensor of air flow temperature sensor simultaneously, do not contact by air flow rate sensor heated air stream medium simultaneously yet, and the temperature of reaction gas flow medium itself only, thereby obtain pure medium temperature signal.The air flow rate deflector structure of the utility model uniqueness can suppress getter device at air intake opening during by shutoff, and the non-intake turbulance that getter device working pressure balance produces can make sensor realize the accurate measurement of zero charge flow rate.
Circuit signal conversion and transitive relation:
Air flow rate sensor, air flow temperature sensor are respectively by separately constant-current source bias, the bias current of air flow rate sensor is enough big, make sensor be in the condition of high temperature, the variation of air flow rate can cause enough variations of resistance of sensor, output gas flow flow signal; The bias current of air flow temperature sensor is very little, and bias current makes the signal that the self-heating of air flow temperature sensor causes change and can ignore, and the temperature of reaction gas flow medium only, the output gas flow temperature signal; This two signal is with separately adjustable voltage benchmark, be input to air flow rate signal differential circuit and air-flow temperature signal difference channel respectively, this two difference channel is regulated by reference voltage separately, makes air flow rate signal and air-flow temperature signal deduct reference voltage separately and adjust to required separately signal working point; According to the air flow rate signal with the dynamic perfromance of moving gaseouse medium temperature variation and air-flow temperature signal with the relation between the dynamic perfromance of moving gaseouse medium temperature variation, the characteristic coupling that adjusted gas flow temperature signal is set is amplified, and makes that the gas flow temperature signal after the coupling amplification is consistent with the dynamic perfromance of moving gaseouse medium temperature variation with the air flow rate signal with the dynamic perfromance of moving gaseouse medium temperature variation; This two paths of signals obtains and the irrelevant air flow rate detection signal of moving gaseouse medium temperature variation by a compensate for poor parallel circuit, makes the air flow rate signal of output meet the requirement of the dynamic range of signals of outside analog to digital conversion circuit by a Signal Matching circuit again.
The superiority of this circuit is to use standardized industrial temperature sensor, realized the air flow rate measurement of low discharge, and solved the difficult problem that the air flow rate measurement is subjected to air-flow temperature effect, made air flow rate measurement range (representing) the 0-2.0 meter per second of this device with flow velocity; The gas flow temperature of-15 ℃ of-+60 ℃ of scopes changes influence to the air flow rate signal less than 10%.Low cost, small size, standardization and high-stability requirement that the attraction type smoke fire detector detects air flow rate have been satisfied.
Description of drawings
Fig. 1 is the assembling section of flow tube and air-flow sensing plate;
Fig. 2 is the vertical view of flow tube;
Fig. 3 is the signal processing module circuit block diagram;
Fig. 4 is the signal processing module circuit theory diagrams;
1 air flow rate sensor wherein, 2 air flow temperature sensors, 3 air-flow sensing plates, 4 fair water fins, 5 flow tubes, Q represents air-flow.
Embodiment
Be described in detail below in conjunction with the embodiment of accompanying drawing the utility model device:
Shown in Fig. 1-2, air flow rate sensor 1, air flow temperature sensor 2, air-flow sensing plate 3, fair water fin 4 and flow tube 5.Wherein the mounting groove cunning of the center line of air-flow sensing plate 3 by being positioned at flow tube 5 is closed the air intake opening end that is installed in flow tube 5, air flow rate sensor 1, air flow temperature sensor 2 are symmetrically welded at the side of air-flow sensing plate 3 near flow tube 5 air intake openings, make the sensitive face of air flow rate sensor 1, air flow temperature sensor 2 on the top of air-flow sensing plate 3, and make the sensitive face of air flow rate sensor 1, air flow temperature sensor 2 vertical with the plate face of air-flow sensing plate 3, meet to the air-flow airintake direction; Be provided with the fair water fin 4 of cross vertical panel planform in the outlet side of flow tube 5, fair water fin 4 cross centre lines overlap with 5 axis; 4 can close installation by mounting groove and flow tube 5 cunnings, also fair water fin 4 and flow tube 5 can be passed through the integrated realization of mould.
Air flow rate metering circuit embodiment:
As shown in Figure 4:
The transducing signal of air flow rate sensor (1) and air flow temperature sensor (2) is connected with the air flow rate metering circuit by connecting line.Wherein (label in air flow rate metering circuit schematic diagram is P1 to the air flow rate sensor, hereinafter to be referred as P1) applied biasing by the constant current source of U2, R1, D1 formation, wherein U2 can be LM317/217/117, its VOUT pin and ADJ pin and to connect resistance be 24 ohm, the metalfilmresistor R1 of 1/1000 precision; Simultaneously according to illustrating and connect the protection diode D1 that model is 1N4148; The bias current of this circuit output 51mA, this circuit is a typical circuit, principle repeats no more;
P1 is connected between bias current output and the signal ground, and magnetic bead LC1 and electric capacity E1 (2.2uF/25V) constitute the filtering link of air flow rate transducing signal;
By U4 (LM385-2.5/LM285-2.5 or other are not less than the voltage reference integrated circuit of 2.5V), C4, E3 and VR1 (10K ohm) be connected in parallel and and R4 (15K ohm) series connection between+15V power supply and signal ground, constitute air flow rate adjustable voltage benchmark, this partial circuit is a typical circuit, and principle repeats no more.
By four high guaily unit integrated circuit U3 (TLC2254 LM324 LM224 LM124 or other replaceable models) three amplifier unit U3C, U3D, U3A and R3 (10K ohm), R5 (2.4K ohm), R6, R7, R8, R9 (R6-R9 is 47K ohm) and E2, C3 constitute the air flow rate signal differential circuit, this partial circuit is a typical circuit, and principle repeats no more.
The air flow rate transducing signal outputs to 10 pin of an input end U3 of air flow rate signal differential circuit by the protection of R2 (10K ohm) and D2 (1N4148); Air flow rate adjustable voltage benchmark outputs to 12 pin of another input end of air flow rate signal differential circuit U3; Through the processing of air flow rate signal differential circuit, export through the adjusted air flow rate measuring-signal of direct current from 1 pin of U3.
Wherein (label in air flow rate metering circuit schematic diagram is P2 to air flow temperature sensor, hereinafter to be referred as P2) by U5 (TLC2254 LM324 LM224 LM124 or other replaceable models) two amplifier unit U5A, U5D, U6 (LM385-1.2/LM285-1.2 or other are not less than the voltage reference integrated circuit of 1.2V), R12 (15K ohm), R17 (1.2K ohm, 1/1000 precision), R13, R14, R15, R16 (R13-R16 is 10K ohm), C5, C6, E4, the constant current source that E5 constitutes applies biasing, the bias current of this circuit output 1mA, this circuit is a typical circuit, and principle repeats no more;
P2 is connected between bias current output and the signal ground, and magnetic bead LC2 and electric capacity E6 (2.2uF/25V) constitute the filtering link of air flow rate transducing signal;
Be cascaded by R32 (10K ohm) and R31 (30K ohm), be connected on the R12 (15K ohm) that connects again after U6, C5, the E4 parallel connection+constitute the gas flow temperature voltage reference between 15V power supply and the signal ground, this partial circuit is a typical circuit, and principle repeats no more;
By amplifier unit U5C of four high guaily unit integrated circuit U5 and four high guaily unit integrated circuit U7 (TLC2254 LM324 LM224 LM124 or other replaceable models) two amplifier unit U7C, U7B and R33 (7.5K ohm), R19, R21, R22, R34, R35 (R19-R35 is 10K ohm) constitute the gas flow temperature signal differential circuit, this partial circuit is a typical circuit, and principle repeats no more;
The gas flow temperature transducing signal outputs to 10 pin of an input end U5 of gas flow temperature signal differential circuit by the protection of R18 (10K ohm) and D3 (1N4148); The gas flow temperature voltage reference outputs to 10 pin of another input end of gas flow temperature signal differential circuit U7; Through the processing of gas flow temperature signal differential circuit, export through the adjusted gas flow temperature measuring-signal of direct current from 7 pin of U7.The compensation characteristic coupling amplifying circuit that this signal input is made of U5B, R20 (3.3K ohm), R23 (3.9K ohm), R24 (15K ohm), R25 (2.2K ohm), C9 (104) is by the temperature compensation signal after the 7 pin output coupling of U5.This partial circuit is a typical circuit, and principle repeats no more;
Be input to the single amplifier compensate for poor parallel circuit that constitutes by U3B, R10 (47K ohm), R11 (47K ohm), R26 (47K ohm), R27 (47K ohm) with temperature compensation signal with through the adjusted air flow rate measuring-signal of direct current; Realize the temperature compensation of air flow rate measuring-signal, this partial circuit is a typical circuit, and principle repeats no more.Wherein temperature compensation signal is imported by R10, import by R26 through the adjusted air flow rate measuring-signal of direct current, air flow rate measuring-signal after the temperature compensation is followed coupling adjustment circuit by connecting R28 to the signal dividing potential drop that is made of U7D, R28 (47K ohm), R29 (47K ohm), R30 (24K ohm), E8 (2.2uF/25V), C7 by the 7 pin output of U3, realizes the Signal Matching of air flow rate simulating signal and external interface.This partial circuit is a typical circuit, and principle repeats no more.
In this circuit, if no special instructions, resistance R adopts the metalfilmresistor of 1/100 precision; Capacitor C is 103 ceramic disc capacitor, and electric capacity E is tantalum electrolysis or the alminium electrolytic condenser of 10uF/25V.
The principle of work of the utility model device is as follows: produced the air-flow that passes flow tube (5) by outside getter device, at first by the air-flow sensing plate (3) of sensor is installed, air flow rate signal and air-flow temperature signal are respectively by air flow rate sensor (1) and air flow temperature sensor (2) perception for air-flow; Air communication is crossed fair water fin (4) afterwards, passes from the gas outlet of flow tube (5).
The principle of work of air flow rate metering circuit is as follows: air flow rate sensor (1), air flow temperature sensor (2) are respectively by separately constant-current source bias, the bias current of air flow rate sensor (1) is enough big, make sensor be in the condition of high temperature, the variation of air flow rate can cause enough variations of resistance of sensor, output gas flow flow signal; The bias current of air flow temperature sensor (2) is very little, and bias current makes the signal that the self-heating of (2) causes change and can ignore, and the temperature of reaction gas flow medium only, the output gas flow temperature signal; This two signal is with separately adjustable voltage benchmark, be input to air flow rate signal differential circuit and air-flow temperature signal difference channel respectively, this two difference channel is regulated by reference voltage separately, makes air flow rate signal and air-flow temperature signal deduct reference voltage separately and adjust to required separately signal working point; According to the air flow rate signal with the dynamic perfromance of moving gaseouse medium temperature variation and air-flow temperature signal with the relation between the dynamic perfromance of moving gaseouse medium temperature variation, the characteristic coupling that adjusted gas flow temperature signal is set is amplified, and makes that the gas flow temperature signal after the coupling amplification is consistent with the dynamic perfromance of moving gaseouse medium temperature variation with the air flow rate signal with the dynamic perfromance of moving gaseouse medium temperature variation; This two paths of signals obtains and the irrelevant air flow rate detection signal of moving gaseouse medium temperature variation by a compensate for poor parallel circuit, makes the air flow rate signal of output meet the requirement of the dynamic range of signals of outside analog to digital conversion circuit by a Signal Matching circuit again.
Claims (2)
1, a kind of detection device of airflow flow is characterized in that, this device comprises air flow rate sensor, air flow temperature sensor, air-flow sensing plate, fair water fin and flow tube; Wherein the mounting groove cunning of the center line of air-flow sensing plate by being positioned at flow tube is closed the air intake opening end that is installed in flow tube, air flow rate sensor, air flow temperature sensor are symmetrically welded at the side of air-flow sensing plate near the flow tube air intake opening, make the sensitive face of air flow rate sensor, air flow temperature sensor on the top of air-flow sensing plate, and make the sensitive face of air flow rate sensor, air flow temperature sensor vertical with the plate face of air-flow sensing plate, meet to the air-flow airintake direction; Be provided with the fair water fin of cross vertical panel planform in the outlet side of flow tube, the cross centre line of fair water fin overlaps with the axis of flow tube;
Its circuit connecting relation is: air flow rate sensor, air flow temperature sensor be respectively by separately constant-current source bias, air flow rate sensor output gas flow flow signal; Air flow temperature sensor output gas flow temperature signal, two signals are with separately adjustable voltage benchmark, be input to air flow rate signal differential circuit and air-flow temperature signal difference channel respectively, two difference channels are regulated by reference voltage separately, make air flow rate signal and air-flow temperature signal deduct reference voltage separately and adjust to required separately signal working point; After the gas flow temperature signal amplifies through the characteristic coupling, by the compensate for poor parallel circuit, obtain and the irrelevant air flow rate detection signal of moving gaseouse medium temperature variation with the air flow rate signal, again by the Signal Matching circuit, the output gas flow flow signal.
2, a kind of detection device of airflow flow as claimed in claim 1 is characterized in that described fair water fin closes installation by mounting groove and flow tube cunning, perhaps fair water fin and flow tube is passed through the integrated realization of mould.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 200520091982 CN2831057Y (en) | 2005-07-29 | 2005-07-29 | Airflow detector |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 200520091982 CN2831057Y (en) | 2005-07-29 | 2005-07-29 | Airflow detector |
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| Publication Number | Publication Date |
|---|---|
| CN2831057Y true CN2831057Y (en) | 2006-10-25 |
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Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN 200520091982 Expired - Fee Related CN2831057Y (en) | 2005-07-29 | 2005-07-29 | Airflow detector |
Country Status (1)
| Country | Link |
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| CN (1) | CN2831057Y (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN100371688C (en) * | 2005-07-29 | 2008-02-27 | 公安部沈阳消防研究所 | Detection device of airflow flow |
| CN115235963A (en) * | 2022-05-25 | 2022-10-25 | 中国船舶重工集团公司第七0三研究所 | Self-correcting linear air suction type smoke detector |
-
2005
- 2005-07-29 CN CN 200520091982 patent/CN2831057Y/en not_active Expired - Fee Related
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN100371688C (en) * | 2005-07-29 | 2008-02-27 | 公安部沈阳消防研究所 | Detection device of airflow flow |
| CN115235963A (en) * | 2022-05-25 | 2022-10-25 | 中国船舶重工集团公司第七0三研究所 | Self-correcting linear air suction type smoke detector |
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| GR01 | Patent grant | ||
| C19 | Lapse of patent right due to non-payment of the annual fee | ||
| CF01 | Termination of patent right due to non-payment of annual fee |