CN201277947Y - Spectrum absorption detection apparatus for coal mine methane gas concentration - Google Patents
Spectrum absorption detection apparatus for coal mine methane gas concentration Download PDFInfo
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- CN201277947Y CN201277947Y CNU2008202221422U CN200820222142U CN201277947Y CN 201277947 Y CN201277947 Y CN 201277947Y CN U2008202221422 U CNU2008202221422 U CN U2008202221422U CN 200820222142 U CN200820222142 U CN 200820222142U CN 201277947 Y CN201277947 Y CN 201277947Y
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Abstract
The utility model relates to a coal-mine gas consistency spectral absorption detecting device which comprises a power supply module, a sensing module, a signal processing module and a storage analyzing module. The power supply module comprises a drive circuit, a stabilized current circuit, a temperature-control circuit and a modulation circuit; the sensing module comprises an LD, a gas chamber and a photodetector; and the storage analyzing module comprises an A/D converter, an oscillograph and a computer. The detecting device has the characteristics of high sensitivity, fast response, large dynamic range, corrosion resistance and small volume without electromagnetism interface, and can realize the long-distance transmission and locale real-time remote detection of signals. The sensing module of the device can be put into a severe environment for detection, can detect the coal-mine gas consistency in real time, eliminate the hidden trouble of the safety in production and has significance in the safety in production in a coal mine.
Description
Technical field
The utility model relates to a kind of methane gas spectral absorption pick-up unit, and particularly a kind of spectral absorption pick-up unit to the coal mine gas gas concentration belongs to detection range.
Background technology
In the China's coal-mine security incident, the number of casualties that gas explosion causes accounts for more than 50% of all major accident number of casualties.In order effectively to detect the fire damp gas concentration, the instrument and equipment of energy online in real time fast detecting methane gas concentration must be set.The basic detection method of methane gas has many kinds such as air-sensitive sensing method, thermocatalysis formula sensing method, vapor-phase chromatography, optical means.Common several detection methods can not online in real time detect the concentration of methane gas, and the sensitivity of its detection simultaneously is also lower, the Safety of Coal Mine Production accident be can not get timely discovery, thereby cause the potential safety hazard of production.
The utility model content
Technical problem to be solved in the utility model is to provide a kind of sensitivity higher at the deficiency of existing coal-mine gas gas concentration detection technique, the coal-mine gas gas concentration spectral absorption pick-up unit that online in real time detects.
For solving the problems of the technologies described above, the technical solution adopted in the utility model is: a kind of coal-mine gas gas concentration spectral absorption pick-up unit is characterized in that being made up of power module, sensing module, signal processing module and inventory analysis module; Described power module comprises driving circuit, current stabilization circuit, temperature control circuit and modulation circuit, and described current stabilization circuit, temperature control circuit and modulation circuit are connected driving circuit respectively; Described sensing module comprises LD, air chamber and photodetector, and the output of LD is sent to the photodetector input end by air chamber; Described signal processing module comprises amplifying circuit, filtering circuit, multifunctional signal generator, multi-point signal averager and selective frequency amplifier circuit, described amplification circuit output end connects filtering circuit, described filtering circuit output terminal connects the multi-point signal averager, described multifunctional signal generator output terminal connects the multi-point signal averager, and described multi-point signal averager output terminal connects selective frequency amplifier circuit; Described inventory analysis module comprises A/D converter, oscillograph and computing machine, and the A/D converter output terminal connects oscillograph, and described oscillograph output terminal connects computing machine; Described driving circuit output terminal connects LD, and described photodetector output terminal connects amplifying circuit, and described selective frequency amplifier circuit output terminal connects A/D converter.
Described amplifying circuit is made up of resistance R 1, R2, R3, capacitor C 1 and operational amplifier LM358; Resistance R 1, R2 and operational amplifier LM358 form an active amplifying circuit, and resistance R 3 is a balance resistance, and capacitor C 1 is finished the High frequency filter of input signal.
Upper end, described air chamber right side is provided with air admission hole, and lower end, described air chamber left side is provided with venthole.
The long 60cm of described air chamber, internal diameter are 3cm.
The utility model is compared with prior art and is had the following advantages:
That this pick-up unit has is highly sensitive, the response fast, dynamic range greatly, is not subjected to electromagnetic interference (EMI), corrosion-resistant, volume is little, can realize that the long Distance Transmission of signal and on-the-spot real-time telemetry, sensor can put into rugged surroundings (as poisonous, high-temperature gas) in, detect the coal-mine gas gas concentration in real time, in time get rid of Safety of Coal Mine Production hidden danger, in Safety of Coal Mine Production, have great importance.
Below by drawings and Examples, the technical solution of the utility model is described in further detail.
Description of drawings
Fig. 1 is the utility model structured flowchart;
Fig. 2 is the structural representation of the utility model air chamber;
Fig. 3 is the circuit diagram of the utility model amplifying circuit;
Fig. 4 is the circuit diagram of the utility model based on the filtering circuit of synchronous integrator;
Fig. 5 is the circuit diagram of the utility model selective frequency amplifier circuit;
Description of reference numerals:
The 1-modulation circuit; The 2-temperature control circuit; The 3-current stabilization circuit;
The 4-driving circuit; 5-LD; The 6-air chamber;
The 7-photodetector; The 8-filtering circuit; 9-multi-point signal averager;
The 10-selective frequency amplifier circuit; The 11-A/D converter; The 12-oscillograph;
The 13-computing machine; The 15-amplifying circuit takes place in the 14-multifunctional signal;
Device;
The 16-venthole; The 17-light source; The 18-air admission hole;
The 20-power module; The 21-sensing module; The 22-signal processing module;
23-inventory analysis module;
Embodiment
As shown in Figure 1, coal-mine gas gas concentration spectral absorption pick-up unit comprises power module 20, sensing module 21, signal processing module 22 and inventory analysis module 23; Described power module 20 comprises driving circuit 4, current stabilization circuit 3, temperature control circuit 2 and modulation circuit 1, and described current stabilization circuit 3, temperature control circuit 2 and modulation circuit 1 are connected driving circuit 4 respectively; Described sensing module 21 comprises LD5, air chamber 6 and photodetector 7, and the output of LD5 is sent to photodetector 7 input ends by air chamber 6; Described signal processing module 22 comprises amplifying circuit 15, filtering circuit 8, multifunctional signal generator 14, multi-point signal averager 9 and selective frequency amplifier circuit 10, described amplifying circuit 15 output terminals connect filtering circuit 8, described filtering circuit 8 output terminals connect multi-point signal averager 9, described multifunctional signal generator 14 output terminals connect multi-point signal averager 9, and described multi-point signal averager 9 output terminals connect selective frequency amplifier circuit 10; Described inventory analysis module 23 comprises A/D converter 11, oscillograph 12 and computing machine 13, and A/D converter 11 output terminals connect oscillograph 12, and described oscillograph 12 output terminals connect computing machine 13; Described driving circuit 4 output terminals connect LD5, and described photodetector 7 output terminals connect amplifying circuit 10, and described selective frequency amplifier circuit 10 output terminals connect A/D converter 11.
The model of power supply is VITC 002 (comprising current stabilization circuit 3, temperature control circuit 2, modulation circuit 1 and driving circuit 4).
What described LD5 selected for use is the semiconductor laser elements that Hangzhou ocean science company limited sells, comprise a single mode double heterojunction semiconductor laser diode LD 5 and a driving power, the LD5 model is VCT1654, operation wavelength is 1.654 μ m, have function of temperature control, table 1 has provided its performance parameter.
Table 1 VCT1654 type LD5 performance parameter
As shown in Figure 2, upper end, the utility model air chamber 6 right sides is provided with air admission hole 18, and the lower end in left side is provided with venthole 16, and light source 17 is injected from air chamber 6 left sides, and the right side is penetrated.Consider workability and sensitivity needs, native system has designed the measurement air chamber 6 of long 60cm, and internal diameter is 3cm, and the air chamber material is made by 95# glass.By calculating, the volume of this air chamber is V=π * (3/2)
2* 60 ≈ 424.115mL.In order to make light be absorbed convenience with equipment fully, air chamber 6 length are selected 60cm, change thereby obtain big light intensity, are convenient to follow-up check and analysis.
Fig. 3 is an amplifying circuit 15, adopts the LM358 operational amplifier, resistance R 1, and R2 and operational amplifier LM358 form an active amplifying circuit, and resistance R 3 is a balance resistance, and capacitor C 1 is finished the High frequency filter to input signal.Amplifying circuit 15 output signal V
o=(1+R2/R1) V
i, play signal V
iFiltering and amplification.
The synchronous integrator circuit that Fig. 4 selects for use for the utility model, input signal will carry out pre-service through low-pass filter earlier in the circuit, pass through the RC integrating circuit of 8 passages then, by these 8 paths of analog switch MAX307 order gating, being provided with signal frequency is f, is 4f with reference to the square-wave signal frequency then, through frequency division again after the phase shift, obtain three kinds of frequency f, the square-wave signal of 2f and 4f is controlled the storbing gate of MAX307.Voltage follower and the bandpass filter of forming through OP177 will be exported the sinusoidal signal that is directly proportional with useful signal at last, and noise is suppressed dramatically.
The multi-point signal averager is a kind of signal processing apparatus, can extract signal from stronger interference and noise, improves signal to noise ratio (S/N ratio) according to the sample averaging of time domain specification, the signal waveform that reproduction is flooded by noise.It is applicable to the Waveshape reproduction of repeating signal, gets a plurality of signal samples after signal occurs successively, and by the fixed frequency repeated sampling.Many sampled signals in each cycle, corresponding one by one successively addition is asked on average, thereby has improved signal to noise ratio (S/N ratio) effectively, for the multi-point signal averager, can realize sum-average arithmetic by number storage or analog memory, and principle is identical.What of the sampling spot of multi-point signal averager, relevant with the accuracy of waveform that requires to reappear, sampling spot is many more, and the reproduction waveform is accurate more.Specifically to sample and how much count, the accuracy of waveform that should reappear as requested, the possibility of cost and technology decides.Adopt the multi-point signal averager of number storage at present, select 120 sampling spots usually for use.This equipment adopts analog memory, and advantage is a visual pattern, and is with low cost.
In the selective frequency amplifier circuit shown in Figure 5, input signal V
InProcess is by R
1, R
2And P
0The inverting amplifier output V that forms
1, V
1As differential amplifier circuit (by R
3, R
5, R
6And P
2Composition) in-phase input signals for 1, the rp input signal of differential amplifier circuit is by output signal V
4Process is by R
8, C
1, P
1The output signal V that the integrating circuit of forming obtains
5, the output signal V of differential amplifier circuit
3Process is by R
7, C
2And P
3The integrating circuit final output signal V that forms
4
Principle of work: power module 20 provides the triangular modulation signal of 480Hz, carries out triangular modulation by the injection current to LD5, makes light source frequency and output intensity also be subjected to corresponding modulation.The optically-coupled that LD5 sends enters air chamber 6, contain the gas that needs detect in the air chamber 6, light is decayed during by air chamber 6, the light signal that comes out from air chamber 6 converts electric signal to by the photoelectric switching circuit the photodetector 7, this electric signal has comprised gas concentration information, by detecting the concentration that this electric signal just can draw gas.The semiconductor laser diode that system selects for use itself has temperature control, adopts the constant-current driving power supply of band temperature control to guarantee the stable of its temperature and output power simultaneously, and actual measurement shows that the light-intensity variation that arrives detector is no more than 0.19%.The output light of system mainly is second harmonic component (first harmonic can be ignored), and is proportional to the concentration of gas, detects the volume fraction that this value just can accurately be measured gas to be measured.Utilize signal processing module 22 to detect second harmonic and handle as system's output and to feeble signal, also noise can be removed simultaneously, the system that makes reaches very high sensitivity.
Claims (4)
1, a kind of coal-mine gas gas concentration spectral absorption pick-up unit is characterized in that being made up of power module, sensing module, signal processing module and inventory analysis module; Described power module comprises driving circuit, current stabilization circuit, temperature control circuit and modulation circuit, and described current stabilization circuit, temperature control circuit and modulation circuit are connected driving circuit respectively; Described sensing module comprises LD, air chamber and photodetector, and the output of LD is sent to the photodetector input end by air chamber; Described signal processing module comprises amplifying circuit, filtering circuit, multifunctional signal generator, multi-point signal averager and selective frequency amplifier circuit, described amplification circuit output end connects filtering circuit, described filtering circuit output terminal connects the multi-point signal averager, described multifunctional signal generator output terminal connects the multi-point signal averager, and described multi-point signal averager output terminal connects selective frequency amplifier circuit; Described inventory analysis module comprises A/D converter, oscillograph and computing machine, and the A/D converter output terminal connects oscillograph, and described oscillograph output terminal connects computing machine; Described driving circuit output terminal connects LD, and described photodetector output terminal connects amplifying circuit, and described selective frequency amplifier circuit output terminal connects A/D converter.
2, coal-mine gas gas concentration spectral absorption pick-up unit according to claim 1 is characterized in that described amplifying circuit is made up of resistance R 1, R2, R3, capacitor C 1 and operational amplifier LM358; Resistance R 1, R2 and operational amplifier LM358 form an active amplifying circuit, and resistance R 3 is a balance resistance, and capacitor C 1 is finished the High frequency filter of input signal.
3, coal-mine gas gas concentration spectral absorption pick-up unit according to claim 1 is characterized in that upper end, described air chamber right side is provided with air admission hole, and lower end, described air chamber left side is provided with venthole.
4, coal-mine gas gas concentration spectral absorption pick-up unit according to claim 1 is characterized in that the long 60cm of described air chamber, and internal diameter is 3cm.
Priority Applications (1)
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CNU2008202221422U CN201277947Y (en) | 2008-10-29 | 2008-10-29 | Spectrum absorption detection apparatus for coal mine methane gas concentration |
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CNU2008202221422U CN201277947Y (en) | 2008-10-29 | 2008-10-29 | Spectrum absorption detection apparatus for coal mine methane gas concentration |
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Cited By (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN103207147A (en) * | 2013-01-18 | 2013-07-17 | 天地(常州)自动化股份有限公司 | Intrinsically safe smog sensor for mine |
CN104849215A (en) * | 2015-04-23 | 2015-08-19 | 天津大学 | Position triangular wave frequency coding plane array imaging light measurement system |
CN104865184A (en) * | 2015-04-23 | 2015-08-26 | 天津大学 | Position triangle wave frequency coding linear array imaging light measuring system |
CN105158211A (en) * | 2015-04-23 | 2015-12-16 | 天津大学 | Linear CCD position triangular wave frequency coded-excitation imaging light measurement system |
CN105241817A (en) * | 2015-11-01 | 2016-01-13 | 李俊娇 | Optical fiber sensing gas detection device |
-
2008
- 2008-10-29 CN CNU2008202221422U patent/CN201277947Y/en not_active Expired - Fee Related
Cited By (6)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN103207147A (en) * | 2013-01-18 | 2013-07-17 | 天地(常州)自动化股份有限公司 | Intrinsically safe smog sensor for mine |
CN103207147B (en) * | 2013-01-18 | 2015-09-02 | 天地(常州)自动化股份有限公司 | Mine intrinsic safety smoke transducer |
CN104849215A (en) * | 2015-04-23 | 2015-08-19 | 天津大学 | Position triangular wave frequency coding plane array imaging light measurement system |
CN104865184A (en) * | 2015-04-23 | 2015-08-26 | 天津大学 | Position triangle wave frequency coding linear array imaging light measuring system |
CN105158211A (en) * | 2015-04-23 | 2015-12-16 | 天津大学 | Linear CCD position triangular wave frequency coded-excitation imaging light measurement system |
CN105241817A (en) * | 2015-11-01 | 2016-01-13 | 李俊娇 | Optical fiber sensing gas detection device |
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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: 20090722 Termination date: 20091130 |