CN2651750Y

CN2651750Y - Low-concentration SF gas realtime checker

Info

Publication number: CN2651750Y
Application number: CN 200320120449
Authority: CN
Inventors: 许建伟
Original assignee: WUJIN WULING DIESEL ENGINE CO Ltd CHANGZHOU CITY
Current assignee: WUJIN WULING DIESEL ENGINE CO Ltd CHANGZHOU CITY
Priority date: 2003-11-04
Filing date: 2003-11-04
Publication date: 2004-10-27
Anticipated expiration: 2013-11-04

Abstract

A low concentration SF 6 gas real time detector is provided, which comprises a shell body and a main control panel with a control circuit. The control circuit of the main control panel is composed of a power source convertor (9), a determination detection circuit (1), a fix quantity detection circuit (2), an A/D converter (3), a singlechip (4), a display unit (7) and a communication interface (8); the determination detection circuit (1) comprises a halogen transducer G1, a resistance R0 and their peripheral circuits; the fixed quantity detection circuit (2) is composed of a transformer T, an oscillator (10), a discharging electrode J1, a resistance R1, a resistance R2, a capacitor C1 and a rectification and filtering circuit composed of a diode D and a capacitor C2; the rectification and filtering circuit applies negative high voltage to the discharging electrode J1. Therefore, the utility model is able to detect whether the SF 6 concentration in the environment exceeds the standards or not, reduces the frequency and duration for the electricity discharge of discharging electrode, greatly prolongs the service life, provides effective means for SF 6 leakage and the alarm upon standard exceeding, realizes distance real time online detection and greatly ensures the health and life safety of operation maintenance personnel.

Description

Low concentration SF 6The gas real-time detector

Technical field

The utility model relates to a kind of micro-SF that is used to detect ₆The low concentration SF of (sulfur hexafluoride) gas concentration ₆The gas real-time detector belongs to the field of gas detection in the environmental protection, is particularly suitable for power department and uses.

Background technology

SF ₆Gas mainly uses at power department, makes insulation and arc-extinguishing medium in high voltage electric equipment.In recent years, high voltage electric equipment is loaded on indoor more, through the SF of arcing and discharge ₆Gas can produce other trace harmful gases, and equipment will inevitably be by micro-SF in long-term the use ₆The leakage of gas.According to SF ₆Some characteristic of gas mainly contain three kinds of measuring methods at present, and the one, utilize SF ₆The receptivity that gas is strong to the infrared ray of some wave band is made thermal infrared imager; The 2nd, utilize sound wave at SF ₆Velocity of propagation is made supersonic reflectoscope than characteristic slow in air in the gas; The 3rd, utilize SF ₆The negative ion leak locator that gas is made the strong absorption effect of electronics.In fact, have only the negative ion leak locator can detect the SF of hundreds of PPM concentration ₆Gas, the promptly suitable SF that detects low concentration ₆Gas, but serviceable life of this negative ion leak locator have only hundreds of hours, the life-span is shorter, needs frequent calibration or replacing stop leakage in the roof instrument, very trouble.And if prolong its serviceable life, then must measure once by certain interval of time, caused the real-time of measurement relatively poor so again.

Summary of the invention

The purpose of this utility model is to overcome the deficiencies in the prior art, provides that a kind of degree of accuracy height, real-time are good, the low concentration SF of long service life ₆The gas real-time detector.

The technical scheme that realizes above-mentioned purpose is: a kind of low concentration SF ₆The gas real-time detector, comprise housing and master control borad with control circuit, control circuit on the master control borad is by supply convertor, the qualitative detection circuit, the detection by quantitative circuit, A/D converter, single-chip microcomputer, display unit and communication interface are formed, qualitative detection circuit and detection by quantitative circuit all are electrically connected with the input end of A/D converter by lead, the output terminal of A/D converter is electrically connected with the input end of single-chip microcomputer, the detection by quantitative circuit also is electrically connected with single-chip microcomputer by lead, display unit and communication interface are electrically connected with single-chip microcomputer by lead respectively, the qualitative detection circuit is by halogen sensor G1, resistance R 0 and their peripheral circuit are formed, the signal electrode 1 of halogen sensor G1 connects power supply, and at the heating electrode 2 of halogen sensor G1, be added with constant voltage between 5, the positive pole of resistance R 0 is connected with the signal electrode of halogen sensor 4, and the voltage of these signal electrode 4 outputs is input to 3 pin of A/D converter; The detection by quantitative circuit is formed by transformer T, oscillator, sparking electrode J1, resistance R 1, resistance R 2, capacitor C 1 with by the current rectifying and wave filtering circuit that diode D and capacitor C 2 are formed, current rectifying and wave filtering circuit is added to negative high voltage on the sparking electrode, voltage on the resistance R 2 is sampling voltage, and this voltage is input to 4 pin of A/D converter.

After adopting technique scheme, the qualitative detection circuit is made up of halogen sensor G1, resistance R 0 and their peripheral circuit, the signal electrode 1 of halogen sensor G1 connects power supply, and between the heating electrode 2,5 of halogen sensor G1, be added with constant voltage, the positive pole of resistance R 0 is connected with the signal electrode of halogen sensor 4, the voltage of signal electrode 4 outputs is input to 3 pin of A/D converter, and halogen sensor is by SnO ₂Semiconductor material is made, and the voltage between the heating electrode 2,5 makes SnO ₂Semiconductor remains on a certain temperature, SnO ₂Semi-conductive resistance changes with the variation of halogen concentration in the environment, and the output voltage of signal electrode 4 just can reflect the state of environment.And the detection by quantitative circuit is formed by transformer T, oscillator, sparking electrode J1, resistance R 1, resistance R 2, capacitor C 1 with by the current rectifying and wave filtering circuit that diode D and capacitor C 2 are formed, current rectifying and wave filtering circuit is added to negative high voltage on the sparking electrode, voltage on the resistance R 2 is sampling voltage, and this voltage is input to 4 pin of A/D converter.Utilize SF ₆Gas is to the strong adsorption effect of electronics, under the fixing prerequisite of constant voltage and electrode position, and near the SF the sparking voltage of sparking electrode and this electrode ₆Gas concentration is certain relation, uses normal concentration SF ₆Gas just can accurately be demarcated this signal voltage.Qualitative detection circuit and detection by quantitative circuit are worked under the coordination of microcomputer monitoring software, the qualitative detection circuit can measure environment capable in SF ₆The fluctuation of gas concentration, but can not detection by quantitative SF ₆The absolute value of gas concentration when this fluctuation has a certain size, starts the detection by quantitative circuit and carries out quantitative accurate measurement, like this, and the continuous working for a long time of qualitative detection circuit, detection by quantitative circuit SF in environment ₆Gas concentration is just worked by than great fluctuation process the time, its objective is the discharge time that as far as possible shortens electrode to increase the service life, and shortens the reaction time of detecting again as far as possible, accomplishes real real-time detection.

Description of drawings

Fig. 1 is the utility model low concentration SF ₆The circuit block diagram of gas real-time detector;

Fig. 2 is the circuit theory diagrams of qualitative detection circuit of the present utility model;

Fig. 3 is the circuit theory diagrams of detection by quantitative circuit of the present utility model;

Fig. 4 is the utility model low concentration SF ₆The circuit theory diagrams of gas real-time detector.

Embodiment

Below in conjunction with drawings and Examples the utility model is described in further detail.

Shown in Fig. 1～4, a kind of low concentration SF ₆The gas real-time detector, comprise housing and master control borad with control circuit, control circuit on the master control borad is by supply convertor 9, qualitative detection circuit 1, detection by quantitative circuit 2, A/D converter 3, single-chip microcomputer 4, display unit 7 and communication interface 8 are formed, qualitative detection circuit 1 and detection by quantitative circuit 2 all are electrically connected by the input end of lead with A/D converter 3, the output terminal of A/D converter 3 is electrically connected with the input end of single-chip microcomputer 4, detection by quantitative circuit 2 also is electrically connected with single-chip microcomputer 4 by lead, display unit 7 and communication interface 8 are electrically connected with single-chip microcomputer 4 by lead respectively, qualitative detection circuit 1 is by halogen sensor G1, resistance R 0 and their peripheral circuit are formed, the signal electrode 1 of halogen sensor G1 connects power supply, and at the heating electrode 2 of halogen sensor G1, be added with constant voltage VT between 5, the positive pole of resistance R 0 is connected with the signal electrode 4 of halogen sensor G1, and the voltage of these signal electrode 4 outputs is input to 3 pin of A/D converter 3; Detection by quantitative circuit 2 is formed by transformer T, oscillator 10, sparking electrode J1, resistance R 1, resistance R 2, capacitor C 1 with by the current rectifying and wave filtering circuit that diode D and capacitor C 2 are formed, current rectifying and wave filtering circuit is added to negative high voltage on the sparking electrode J1, voltage on the resistance R 2 is sampling voltage, and this voltage is input to 4 pin of A/D converter 3.The model of A/D converter is TLC0834, and the model of single-chip microcomputer is 89S52, and the model of communication interface 8 is RS485.

Shown in Fig. 1,4, single-chip microcomputer 4 also is connected with an address scrambler 6 by lead.This address scrambler 6 is made up of 4 toggle switch SW1, and it can be provided with 16 kinds of different addresses, for a plurality of sensor identifications of bus.

Shown in Fig. 1,4, single-chip microcomputer 4 also is connected with a power sense circuit 5 by lead.This power sense circuit 5 is made up of integrated package U2 and peripheral circuit thereof, and the model of U2 is X25045, adopts power sense circuit 5 can improve antijamming capability of the present utility model, improves reliability of operation.

Shown in Fig. 1～4, principle of work of the present utility model is as follows: add constant voltage VT between the heating electrode 2,5 of halogen sensor G1, make the semiconductor substrate of halogen sensor G1 inside maintain a stationary temperature, the impedance meeting between the signal electrode 1,4 of halogen sensor G1 is with SF in the environment ₆The concentration of gas and changing, this variation is reflected on the voltage that A shown in Figure 2 orders, 3 pin of A point voltage input a/d converter, the output terminal of A/D converter is connected with the P1 mouth of single-chip microcomputer 4 by spi bus, single-chip microcomputer 4 can periodically read the magnitude of voltage that A is ordered, when the fluctuation of A point voltage surpasses certain limit, single-chip microcomputer 4 produces the higher-order of oscillation by control signal C (referring to Fig. 3) control generator 10, by transformer T and current rectifying and wave filtering circuit negative high voltage is added to sparking electrode J1, voltage on the R2 is that the B point voltage is the sampling voltage of discharge current, the B point voltage is input to 4 pin of A/D converter, the output terminal of A/D converter is connected with the P1 mouth of single-chip microcomputer 4 by spi bus, single-chip microcomputer 4 reads the B point voltage and compares with calibration value, draws ambient condition, if SF ₆Gas concentration exceeds standard, and the alarm lamp D1 that exceeds standard lights (referring to Fig. 4), lights pilot lamp D2 during qualitative detection, lights pilot lamp D3 during detection by quantitative.SF in the environment ₆The gas concentration state sends monitoring host computer to by the integrated package U5 in the RS485 interface circuit, realizes Long-distance Control.

In sum, the i.e. SF in the testing environment in real time of the utility model ₆Whether gas concentration exceeds standard, and can reduce the number of times and the time of sparking electrode discharge again, has prolonged low concentration SF greatly ₆In the serviceable life of gas concentration real-time detector, be SF ₆Gas leaks exceeding standard warning effective means is provided.If form the real-time online detection system, can realize to SF ₆Operating maintenance personnel's healthy and life security has greatly been safeguarded in the online detection of the remote live of gas apparatus room environmental.

Claims

1, a kind of low concentration SF ₆The gas real-time detector, comprise housing and master control borad with control circuit, control circuit on the master control borad is by supply convertor (9), qualitative detection circuit (1), detection by quantitative circuit (2), A/D converter (3), single-chip microcomputer (4), display unit (7) and communication interface (8) are formed, qualitative detection circuit (1) and detection by quantitative circuit (2) all are electrically connected by the input end of lead with A/D converter (3), the output terminal of A/D converter (3) is electrically connected with the input end of single-chip microcomputer (4), detection by quantitative circuit (2) also is electrically connected with single-chip microcomputer (4) by lead, display unit (7) and communication interface (8) are electrically connected with single-chip microcomputer (4) by lead respectively, it is characterized in that:

A, qualitative detection circuit (1) are made up of halogen sensor G1, resistance R 0 and their peripheral circuit, the signal electrode 1 of halogen sensor G1 connects power supply, and between the heating electrode 2,5 of halogen sensor G1, be added with constant voltage, the positive pole of resistance R 0 is connected with the signal electrode 4 of halogen sensor G1, and the voltage of these signal electrode 4 outputs is input to 3 pin of A/D converter (3);

B, detection by quantitative circuit (2) form by transformer T, oscillator (10), sparking electrode J1, resistance R 1, resistance R 2, capacitor C 1 with by the current rectifying and wave filtering circuit that diode D and capacitor C 2 are formed, current rectifying and wave filtering circuit is added to negative high voltage on the sparking electrode J1, voltage on the resistance R 2 is sampling voltage, and this voltage is input to 4 pin of A/D converter (3).

2, low concentration SF according to claim 1 ₆The gas real-time detector is characterized in that: single-chip microcomputer (4) also is connected with an address scrambler (6) by lead.

3, low concentration SF according to claim 1 and 2 ₆The gas real-time detector is characterized in that: single-chip microcomputer (4) also is connected with a power sense circuit (5) by lead.