CN2171759Y

CN2171759Y - Detecting device for safety valve on line

Info

Publication number: CN2171759Y
Application number: CN 93208262
Authority: CN
Inventors: 徐玉检; 刘琨
Original assignee: Individual
Current assignee: Individual
Priority date: 1993-04-06
Filing date: 1993-04-06
Publication date: 1994-07-13
Anticipated expiration: 2003-04-06

Abstract

The utility model relates to an on-line detecting device for safety valves, comprising a lifting mechanism, a hydraulic system, a force sensor and two displacement sensors A or B. The displacement sensor A is composed of a coil, a copper core, an iron core and an outer shell. The coil is integrated with the outer shell and is fixed on an upright post. The inner core is connected by the iron which is arranged on the upper part and the copper which is arranged on the lower part. The iron core is connected with a lifting draw rod. The copper core is connected with a valve rod. The displacement sensor B is composed of a primary coil, a secondary coil, an iron core and an outer shell. The secondary coil is integrated with the outer shell and is fixed on the upright post. The primary coil is connected with the iron core into a whole. The upper and the lower parts of the iron core are respectively connected with the lifting draw rod and the valve rod. The detection result is accurate.

Description

Detecting device for safety valve on line

The utility model relates to a kind of safety and cuts down on-line equipment, is used for the online detection that safety is cut down on boiler such as oil, chemical industry, middle-size and small-size power plant, heating and the pressure vessel and equipment.

It is the important safety annex of equipment such as boilers and pressure vessel that safety is cut down, and the regular detection that safety is cut down is one of big event of device security supervision, detects safety and cuts down and be divided into two kinds of offline inspection (cold conditions detection) and online detections (hot detection).Offline inspection is safety to be cut down from service line unload, and cuts down in special safety and debugs level pressure on the check table.Online detection is a kind of method of progressively promoting both at home and abroad in recent years, it needn't unload safety and cut down, still be operated in the normal medium operating mode and allow safety cut down, the anchor clamps of the on-line detector device that one cover is special place and cut down, adopt hydraulic system that safety is cut down core and apply an additional force that makes progress and force and cut down core and open, according to the record of instrument to calculate the cracking pressure that safety is cut down.

Existing safety is cut down on-line measuring device and is seen Fig. 9, partly is made up of lifting gear, hydraulic system and electronic surveying.Hydraulic system principle figure is seen Figure 10, comprise lift cylinder 4, positive closing oil cylinder 5, quick release coupling 42, high pressure hose 43, one-way throttle cuts down 44, the 3-position 4-way manual reverse of direction cuts down 33, pressure gauge 34, decompression cuts down 45, by cutting down 46, accumulator 47, oil pump 48, filter 30 and fuel tank 31, pressure oil from hydraulic system, act on lift cylinder 4 by hydraulic tubing 12, cutting down to safety provides speed all even adjustable upwards lifting force on the bar 9, force and cut down core 11 and open under the operating mode in work, by the force transducer 6 and the displacement transducer 40 of electronic surveying part (not shown on the figure), record and note additional lifting force value and the change curve that cuts down the core shift value.Consider that displacement transducer 40 is sides that are installed on lifting gear 13 by bogie 41, because it is not enough to cut down the manufacturing and the installation precision of bar, cut down bar and cut down between the bar via hole and certain clearance occurs, add the error of centralization of lifting gear, therefore, the incipient stage that applies additional force (promptly cut down core open as yet before), cut down core and can produce slight rocking, the direction that the value of rocking strengthens and rocks after guide rod amplifies changes with the difference of mounting point, thereby greatly reduce the degree of accuracy that records of shift value (promptly cutting down the core opening point), thereby shift value is only suitable as the reference value, actual is that turnover or peak value with the power value change curve that records serves as according to estimating opening point, the opening point that this indirect Estimation goes out is difficult to accurately certainly, so existing safety is cut down online detection method and is had the following disadvantages:

1. the shape difference of the different operating mode value of exerting oneself change curves, dissimilar, the shape that the safety of model and manufacturer is cut down power value change curve is also different, even same safety is cut down different owing to what install and adjust, power value change curve also has very big variation, this just gives to measure increases sizable difficulty, when the artificial judgment opening point, require the operator that suitable experience is arranged, and the operating mode that safety is cut down there is more understanding, when adopting computer to judge opening point, require computer to do suitable complex mathematical computing, procedure quantity is big, committed memory is many, also need compare many manual interventions simultaneously, just can obtain satisfied result, when curve shape special, because curve break is not obvious, manually still computer all is difficult to obtain result accurately.

2. require the increase of lifting force mild and even, hydraulic lifting mechanism is to satisfy above-mentioned requirements, assurance power value curve smoothing and turnover evident characteristic means, but hydraulic system is complicated heavy inconvenient with safeguarding with behaviour, thereby limited the application of this detector, and manual or electric hoisting mechanism, though simple structure and convenient operating maintenance can't draw accurate result because a capable value change curve is unsmooth.

3. whole testing process link is many, the cost height, and complicated operation, sense cycle is long, promptly uses single-chip microcomputer to be difficult to also realize that low cost, highi degree of accuracy and fast and convenient automation detect.

4. cut down the safety of type such as cutting down with pulse and cut down for little opening, different and characteristic point is failed to understand and can't accurately be detected because of power value plots changes.

The purpose of this utility model is to overcome above-mentioned deficiency of the prior art and provides a kind of direct employing change in displacement to measure the method and apparatus that safety on line cuts down cracking pressure.

This reality and novel purpose can reach by following measure:

The utility model is to adopt change in displacement to measure the safe cracking pressure of cutting down to finish online detection.

Start oil hand pump, enter lift cylinder after cutting down from hydraulic filter, oil pump and the commutation of fuel tank, raising rod drive sensor, displacement transducer and safety are cut down bar and are promoted together, safety is cut down core and is opened, shift value of opening and the preposition amplification power value of process, calculate cracking pressure and demonstration through data acquisition control and single-chip microcomputer, perhaps after data acquisition control, directly show.

The utility model comprises lifting gear, force transducer, displacement transducer, hydraulic system and contains the electronic surveying part of data acquisition control.

Displacement transducer has A or two kinds of structural types of B:

The A kind comprises elementary secondary winding, copper core, iron core and shell, the elementary secondary winding of differential transformer and shell are made of one and are fixed on the column, inner core is to go up the one that is linked to be for the copper core down for iron core, iron core is connected with raising rod, the copper core with cut down bar and be connected, coiler part is motionless during detection, and the metal inner core promotes with pull bar, thereby causes winding inductance quantity to change and form displacement signal output.

The B kind comprises primary air, secondary winding, iron core (containing bolt, nuts and washers) and shell, two groups of secondary winding of differential transformer and shell are made of one and are fixed on the column, one group of primary air and iron core link into an integrated entity, iron core up and down respectively with raising rod with cut down bar and be connected, detection is motionless to secondary winding, primary air promotes with raising rod together with iron core, thereby causes the secondary inductance amount to change and form displacement signal output.

Lifting gear is made up of upper beam, underbeam and pull bar.Safety is cut down bar and is connected with the copper core of A kind displacement transducer, perhaps the mandrel lower with B kind displacement transducer is connected, and the iron core of lift cylinder, positive closing oil cylinder, force transducer and A kind displacement transducer or the iron core top of B kind displacement transducer are by contacting by the raising rod of upper beam center hole.

Hydraulic system comprises that fuel tank, filter, oil hand pump, pressure gauge, 3-position 4-way manual reverse of direction cut down, lift cylinder, positive closing oil cylinder and hydraulic tubing.

Electronic surveying partly comprises preamplifier, data acquisition control, single-chip microcomputer and display device.Data acquisition control comprises diode, potentiometer, LM311 voltage comparator, 74LSO4 phase inverter LM393 sampling holder, resistance and electric capacity.

The drawing of accompanying drawing is described as follows:

Fig. 1 is detection device figure of the present utility model;

Fig. 2 is the utility model A kind displacement transducer front view;

Fig. 3 is the top view of Fig. 2;

Fig. 4 is the utility model B kind displacement transducer front view;

Fig. 5 is the top view of Fig. 4;

The hydraulic system principle figure that Fig. 6 uses for the utility model lifting gear;

Fig. 7 is the schematic representation of electronic surveying part of the present utility model;

Fig. 8 is a data acquisition control schematic diagram of the present utility model;

Fig. 9 is the detection device figure of prior art;

The hydraulic system principle figure that Figure 10 uses for the prior art lifting gear.

The utility model is described in further detail below in conjunction with embodiment and accompanying drawing:

Fig. 1 represents detection device figure of the present utility model, and Fig. 2 and Fig. 3 represent facing and top view of A kind displacement transducer that the utility model is used.The central upper of displacement sensor 14 is an iron core 16, the iron core top center has screw, be connected with raising rod 8, mandrel lower has copper core 17, iron core and copper core link into an integrated entity, and there is screw in copper core bottom centre, cut down bar 9 with survey safety and are connected, outer and the shell 20 interior dress differential transformer coils 15 of core, coil 15 and shell 20 are fixedly connected on two pull bars 3 by the connecting rod 18 and the adapter sleeve 19 on both sides together.Lifting gear 13 is formed a framework by upper beam 1, underbeam 2 and pull bar 3, safety is cut down bar 9 and is connected with the copper core of displacement transducer 14, raising rod by put the beams in place 1, lift cylinder 4, positive closing oil cylinder 5 and force transducer 6 be connected on the iron core 16 of displacement transducer.

Fig. 4 and Fig. 5 represent facing and top view of B kind displacement transducer 21 of the present utility model.Displacement transducer 21 centers are primary air 26, link into an integrated entity with bolt 22, packing ring 23 and nut 24, two groups of secondary winding 27 are made of one with shell 25, be fixed on the column 3 by connecting rod 18 and adapter sleeve 19, the bottom of bolt 22 is cut down bar 9 by connecting sleeve 28 with safety and is connected, and bolt top is connected with raising rod 8.

Fig. 6 represents the hydraulic system principle that the utility model lifting gear is used, and hydraulic system comprises that the 3-position 4-way manual reverse of direction cuts down 33, pressure gauge 34, oil hand pump 29, filter 30, fuel tank 31, lift cylinder 4, positive closing oil cylinder 5 and hydraulic tubing 12.

Fig. 7 represents the electric device skeleton diagram of the utility model electronic surveying part.Comprise force transducer 6, displacement transducer 7, data acquisition control 37, preamplifier 38, single-chip microcomputer 35 and display device 36, force transducer, preamplifier, single-chip microcomputer and display device all are existing outsourcing piece or the device formed with existing electronic parts and components, displacement transducer has two kinds of structural types of A, B, sees for details above-mentioned.

Fig. 8 represents the schematic diagram of data acquisition control of the present utility model.D ₁And D ₂Be diode, W ₁, W ₂, W ₃Be potentiometer, A ₁Be LM311 voltage comparator, A ₂Be 74LSO4 phase inverter, A ₂Be the LM393 sampling holder, R is a resistance, and C is an electric capacity.A is connected to force transducer preamplifier output, and B is connected to Chip Microcomputer A/D end or directly to data display unit.

When needs cut down 10 when carrying out online detection with the utility model to safety, start oil hand pump 29, hydraulic oil process filter 30 from fuel tank 31, hand oil pump 29 and 3-position 4-way manual reverse of direction cut down and cut down core among the 27(figure and need move to right position) after, enter lift cylinder 4, the iron core 16 of raising rod 8 drive sensors 6 and A kind displacement transducer 14 is together with copper core 17, or the bolt 22 of B kind displacement transducer and connecting sleeve 28, cutting down bar 9 with safety promotes together, safety is cut down core 11 and is opened, the pairing shift value of opening point, during with A kind displacement transducer 14 elementary secondary inductance quantitative changeization and the displacement signal that forms, during with B kind displacement transducer 21 secondary inductance quantitative changeization and the displacement signal that forms, this displacement signal and the force transducer 6 measured and force signals after preposition amplification, together enter data acquisition control 37, calculate cracking pressure through single-chip microcomputer 35, show by display device 36, can also be through directly on display device 36, showing after the data acquisition control 37.Cracking pressure is calculated simple than prior art, only needs the slope variation rate of measuring and calculating displacement amount can find opening point and this to put pairing lifting force value rapidly, calculates cracking pressure with working pressure value of measuring simultaneously and known sealing area.

The utility model contrast prior art has following advantage: testing result is more accurate; Hydraulic system is simpler; Can realize that low cost, high accuracy and fast and convenient automation detect.

Claims

A kind of safety is cut down on-line measuring device, comprise lifting gear, force transducer and hydraulic system, it is characterized in that, displacement transducer has A or two kinds of structural types of B, the A kind comprises elementary secondary winding, the copper core, iron core and shell, the elementary secondary winding of differential transformer and shell are made of one and are fixed on the column, inner core is to go up the one that is linked to be for the copper core down for iron core, iron core is connected with raising rod, the copper core with cut down bar and be connected, coiler part is motionless during detection, the metal inner core promotes with pull bar, thereby causes winding inductance quantity to change and form signal output, and the B kind comprises primary air, secondary winding, iron core and shell, two groups of primary air of differential transformer and shell are made of one and are fixed on the column, one group of primary air and iron core link into an integrated entity, iron core up and down respectively with raising rod with cut down bar and be connected, secondary winding is motionless during detection, primary air promotes with raising rod together with iron core, thereby causes the secondary inductance amount to change and form displacement signal output.