CN111446109A

CN111446109A - Maintenance-free gas density relay and calibration method thereof

Info

Publication number: CN111446109A
Application number: CN202010354474.1A
Authority: CN
Inventors: 蒲东海; 金海勇; 雷邦文; 贺兵; 王恩林
Original assignee: Shanghai Roye Electric Science and Technology Co Ltd
Current assignee: Shanghai Roye Electric Science and Technology Co Ltd
Priority date: 2020-04-29
Filing date: 2020-04-29
Publication date: 2020-07-24
Anticipated expiration: 2040-04-29
Also published as: CN111446109B

Abstract

The application provides a maintenance-free gas density relay and a calibration method thereof, and the maintenance-free gas density relay comprises a gas density relay body, a gas density detection sensor, a gas circuit cut-off voltage regulating mechanism, an online calibration contact signal sampling unit and an intelligent control unit. The gas circuit is by pressure regulating mechanism includes mobilizable shutoff piece in seal chamber and the seal chamber, the unit control drive part drive of intelligence accuse is cut off the piece and is removed, in order to turn off the gas circuit between electrical equipment and the gas density relay body, simultaneously, the removal of shutoff piece makes the gas circuit change by the air chamber volume of pressure regulating mechanism, make the gas density relay body take place the contact action, the density value when intelligence accuse unit moves according to the contact detects out contact signal action value, need not the operation and maintenance personnel to the scene, realize density relay's non-maintaining. Particularly, the gas circuit cut-off pressure regulating mechanism with the cut-off piece is adopted, so that the problems of gas circuit cut-off and pressure regulation are solved, and the gas circuit cut-off pressure regulating mechanism is better in sealing performance, smaller in size and higher in reliability during operation and verification.

Description

Maintenance-free gas density relay and calibration method thereof

Technical Field

The invention relates to the technical field of electric power, in particular to a maintenance-free gas density relay applied to high-voltage and medium-voltage electrical equipment and a calibration method thereof.

Background

The SF6 gas plays a role in arc extinction and insulation in high-voltage electrical equipment, and the safe operation of the SF6 high-voltage electrical equipment is seriously influenced if the density of the SF6 gas in the high-voltage electrical equipment is reduced and the micro water content is exceeded: the reduction of SF6 gas density to some extent will result in loss of insulation and arc extinguishing properties.

With the continuous and vigorous development of the intelligent power grid in China, intelligent high-voltage electrical equipment is used as an important component and a key node of an intelligent substation, and plays a significant role in improving the safety of the intelligent power grid. At present, most of high-voltage electrical equipment is SF6 gas insulation equipment, and if the gas density is reduced (caused by leakage and the like), the electrical performance of the equipment is seriously influenced, and serious hidden danger is caused to safe operation. At present, the online monitoring of the gas density value in the SF6 high-voltage electrical equipment is very common, and therefore, the application of the gas density monitoring system (gas density relay) is developed vigorously. Whereas current gas density monitoring systems (gas density relays) are basically: 1) the remote transmission type SF6 gas density relay is used for realizing the acquisition and uploading of density, pressure and temperature and realizing the online monitoring of the gas density. 2) The gas density transmitter is used for realizing the acquisition and uploading of density, pressure and temperature and realizing the online monitoring of the gas density. The SF6 gas density relay is the core and key component. The periodic inspection of the gas density relay on the electrical equipment is a necessary measure for preventing the trouble in the bud and ensuring the safe and reliable operation of the electrical equipment. The 'electric power preventive test regulations' and the 'twenty-five key requirements for preventing serious accidents in electric power production' both require that the gas density relay be periodically checked. Therefore, at present, the verification of the gas density relay is very important and popular in an electric power system, various power supply companies, power plants and large industrial and mining enterprises are implemented, and the power supply companies, the power plants and the large industrial and mining enterprises need to be equipped with testers, equipment vehicles and high-value SF6 gas for completing the field verification and detection work of the gas density relay. Including power failure and business loss during detection, the detection cost of each high-voltage switch station, which is allocated every year, is about tens of thousands to tens of thousands yuan. In addition, if the field check of the detection personnel is not standard in operation, potential safety hazards also exist. Therefore, it is necessary to innovate the existing gas density self-checking gas density relay, especially the gas density on-line self-checking gas density relay or system, so that the gas density relay for realizing the on-line gas density monitoring or the monitoring system formed by the gas density relay also has the checking function of the gas density relay, and then the regular checking work of the (mechanical) gas density relay is completed, no operation and maintenance personnel are needed to check and maintain the density relay on site, the density relay is free from maintenance, the reliability of the power grid is improved, and the cost is reduced.

Disclosure of Invention

The present invention is directed to a maintenance-free gas density relay and a calibration method thereof, so as to solve the problems mentioned in the background.

In order to achieve the purpose, the invention adopts the following technical scheme:

a first aspect of the present application provides a maintenance-free gas density relay comprising: the gas density relay comprises a gas density relay body, a gas density detection sensor, a gas circuit cut-off pressure regulating mechanism, an online check contact signal sampling unit and an intelligent control unit;

the gas density detection sensor is communicated with the gas density relay body;

the gas circuit cut-off pressure regulating mechanism comprises a first cavity and a second cavity which are communicated with each other, and the section specification of the first cavity is smaller than that of the second cavity; a second interface connected with the electrical equipment is arranged on the front wall of the first cavity, a first interface communicated with the gas path of the gas density relay body is arranged on the side wall of the second cavity, and a third interface is arranged at one end, far away from the first cavity, of the second cavity; a stopping piece can movably enter and exit the first cavity, and the stopping piece enters the first cavity and then is in sealing contact with the inner wall of the first cavity so as to cut off the air path between the first interface and the second interface; the stopping piece is arranged at one end of the connecting piece, and the other end of the connecting piece penetrates through the second cavity, extends out of the third interface and then is connected with the driving part; the driving part drives the stopping part to move in the first cavity through the connecting part and is used for adjusting the pressure rise and fall of the gas density relay body so as to enable the gas density relay body to generate contact signal action;

the online check contact signal sampling unit is directly or indirectly connected with the gas density relay body and is configured to sample a contact signal of the gas density relay body;

the intelligent control unit is respectively connected with the gas circuit cut-off pressure regulating mechanism, the gas density detection sensor and the online check contact signal sampling unit, and is configured to complete control of the gas circuit cut-off pressure regulating mechanism, pressure value collection, temperature value collection and/or gas density value collection, and detection of a contact signal action value and/or a contact signal return value of the gas density relay body;

wherein the contact signal comprises an alarm, and/or a latch.

A first aspect of the present application provides a maintenance-free gas density monitoring apparatus comprising: the gas density relay comprises a gas density relay body, a gas density detection sensor, a gas circuit cut-off pressure regulating mechanism, an online check contact signal sampling unit and an intelligent control unit;

wherein the contact signal comprises an alarm, and/or a latch.

Preferably, the longitudinal sections of the second cavity and the first cavity are of a stepped gradual reduction structure or a continuous reduction structure.

Preferably, the gas circuit pressure regulating mechanism is further provided with a fixed guide part, the fixed guide part is arranged in the second cavity or at the third interface, the fixed guide part is perpendicular to the axial direction of the connecting piece, and the fixed guide part is provided with a guide hole for the connecting piece to pass through.

Preferably, the outer diameter of the connector is smaller than the inner diameter of the first cavity.

Preferably, the shut-off member is a piston or a sealing spacer.

Preferably, a sealing element is arranged on the stopping element, and the stopping element is in sealing contact with the inner wall of the first cavity through the sealing element; preferably, the sealing element is any one of a rubber ring, a rubber pad or an O-ring.

Preferably, the stopping piece and the connecting piece are designed integrally and are directly connected with the driving part.

Preferably, the outer surface of the connector is in sealing contact with the third port from which the connector extends.

More preferably, a part of the connecting piece penetrating through the third port is provided with a connecting piece sealing piece, and the connecting piece is in sealing contact with the inner wall of the third port through the connecting piece sealing piece.

Preferably, the air path stopping and pressure regulating mechanism further includes a sealing coupling piece, one end of the sealing coupling piece is connected with the third interface in a sealing manner, and the other end of the sealing coupling piece is connected with the driving end of the driving part in a sealing manner, or the sealing coupling piece hermetically wraps the connecting piece and the driving part in the sealing coupling piece.

More preferably, the sealing coupling comprises one of a bellows, a sealing balloon, a sealing ring.

Preferably, the driving component comprises one of a magnetic force mechanism, a motor, an electric push rod motor, a stepping motor, a reciprocating mechanism, a carnot cycle mechanism, an air compressor, a deflation valve, a pressure generating pump, a booster valve, an electric air pump, an electromagnetic air pump, a pneumatic element, a magnetic coupling thrust mechanism, a heating thrust generating mechanism, an electric heating thrust generating mechanism and a chemical reaction thrust generating mechanism.

Preferably, the gas density relay or the gas density monitoring device further includes: and a cut-off switch state monitor provided on the driving member or the sealing link, for monitoring a switch state of the cut-off.

Preferably, the gas path cut-off pressure regulating mechanism is sealed in a cavity or a shell.

More preferably, the drive member is disposed within the cavity or housing.

Preferably, the gas path cut-off pressure regulating mechanism further comprises a connecting pipe, and the first interface is communicated with the gas path of the gas density relay body through the connecting pipe.

Preferably, the gas circuit cut-off pressure regulating mechanism further comprises a third cavity arranged between the first cavity and the second cavity, two ends of the third cavity are respectively communicated with the first cavity and the second cavity, and longitudinal sections of the second cavity, the third cavity and the first cavity are of a stepped gradually-reduced structure or a continuously-reduced structure; the other end of the connecting piece penetrates through the third cavity and the second cavity in sequence, extends out of the third interface and is connected with the driving part; the part of the connecting piece, which is positioned on the second cavity, is penetrated with a pressure change piece, the pressure change piece can movably pass in and out of the third cavity, and the pressure change piece is in sealing contact with the inner wall of the third cavity after entering the third cavity.

More preferably, the pressure changing member is a piston or a seal spacer.

More preferably, a sealing member is arranged on the pressure change member, and the pressure change member is in sealing contact with the inner wall of the third cavity through the sealing member; preferably, the sealing element is any one of a rubber ring, a rubber pad or an O-ring.

Preferably, the gas path cut-off pressure regulating mechanism further comprises a fourth cavity and a fifth cavity which are arranged between the first cavity and the second cavity, the first cavity, the fourth cavity, the fifth cavity and the second cavity are sequentially communicated, the cross-sectional specification of the fourth cavity is larger than that of the first cavity, and the cross-sectional specification of the fifth cavity is smaller than that of the first cavity; the other end of the connecting piece penetrates through the fourth cavity, the fifth cavity and the second cavity in sequence, extends out of the third interface and then is connected with the driving part; and a second pressure change piece penetrates through the part of the connecting piece, which is positioned in the second cavity, movably enters and exits the fifth cavity, and after entering the fifth cavity, the second pressure change piece is in sealing contact with the inner wall of the fifth cavity.

More preferably, the second pressure changing member is a piston or a seal spacer.

More preferably, a sealing member is arranged on the second pressure changing member, and the second pressure changing member is in sealing contact with the inner wall of the fifth cavity through the sealing member; preferably, the sealing element is any one of a rubber ring, a rubber pad or an O-ring.

Preferably, the gas density relay or gas density monitoring device further comprises: and the second interface of the gas path cut-off pressure regulating mechanism is communicated with the gas path of the electrical equipment through the multi-way joint.

Preferably, the intelligent control unit acquires a gas density value acquired by the gas density detection sensor; or, the intelligence accuse unit acquires the pressure value and the temperature value that gas density detection sensor gathered accomplish gas density relay or gas density monitoring devices are to the on-line monitoring of the gas density of the electrical equipment who monitors.

Preferably, the intelligent control unit acquires a gas density value acquired by the gas density detection sensor when the gas density relay body generates contact signal action or switching, and completes online verification of the gas density relay or the gas density monitoring device; alternatively, the first and second electrodes may be,

the intelligence accuse unit acquires when the gas density relay body takes place contact signal action or switches the pressure value and the temperature value that gas density detection sensor gathered to according to the pressure value that gas pressure-temperature characteristic conversion becomes corresponding 20 ℃, gas density value promptly, accomplish gas density relay or gas density monitoring devices's online check-up.

Preferably, the intelligent control unit automatically controls the whole verification process based on an embedded algorithm and a control program of an embedded system of the microprocessor, and comprises all peripherals, logic and input and output.

More preferably, the intelligent control unit automatically controls the whole verification process based on embedded algorithms and control programs such as a general-purpose computer, an industrial personal computer, an ARM chip, an AI chip, a CPU, an MCU, an FPGA, a P L C, an industrial control motherboard, an embedded main control board and the like, and includes all peripherals, logic, input and output.

Preferably, the intelligent control unit is provided with an electrical interface, and the electrical interface completes test data storage, and/or test data export, and/or test data printing, and/or data communication with an upper computer, and/or analog quantity and digital quantity information input.

Preferably, the intelligent control unit further comprises a communication module for realizing remote transmission of test data and/or monitoring results, and the communication mode of the communication module is a wired communication mode or a wireless communication mode.

Preferably, a clock is further arranged on the intelligent control unit, and the clock is configured to be used for regularly setting the monitoring time of the gas density relay body, or recording the testing time, or recording the event time.

Preferably, the control of the intelligent control unit is controlled through a field control and/or a background control.

Preferably, the gas density relay body includes, but is not limited to, a bimetal compensated gas density relay, a gas compensated gas density relay, a bimetal and gas compensated hybrid gas density relay; a fully mechanical gas density relay, a digital gas density relay, a mechanical and digital combined gas density relay; the gas density relay with pointer display, the digital display type gas density relay and the gas density switch without display or indication; SF6 gas density relay, SF6 mixed gas density relay, N2 gas density relay.

Preferably, the gas density relay body includes: the device comprises a shell, a base, a pressure detector, a temperature compensation element and a plurality of signal generators, wherein the base, the pressure detector, the temperature compensation element and the signal generators are arranged in the shell; the gas density relay body outputs a contact signal through the signal generator; the pressure detector comprises a bourdon tube or a bellows; the temperature compensation element adopts a temperature compensation sheet or gas sealed in the shell.

Preferably, the gas density detection sensor is provided on the gas density relay body; or the gas density detection sensor is arranged on the gas path cut-off pressure regulating mechanism.

Preferably, the gas density detection sensor comprises at least one pressure sensor and at least one temperature sensor; or, the gas density detection sensor adopts a gas density transmitter consisting of a pressure sensor and a temperature sensor; or, the gas density detection sensor adopts a density detection sensor of quartz tuning fork technology.

More preferably, the pressure sensor is mounted on the gas path of the gas density relay body; the temperature sensor is arranged on or outside the gas path of the gas density relay body, or in the gas density relay body, or outside the gas density relay body.

More preferably, the temperature sensor may be a thermocouple, a thermistor, a semiconductor type; can be a contact type and a non-contact type; can be thermal resistance and thermocouple; may be digital or analog.

More preferably, the pressure sensor may also be a diffused silicon pressure sensor, a MEMS pressure sensor, a chip pressure sensor, a coil-induced pressure sensor (e.g., a pressure sensor with an induction coil in the bawden tube), a resistive pressure sensor (e.g., a pressure sensor with a slide wire resistor in the bawden tube); the pressure sensor can be an analog pressure sensor or a digital pressure sensor.

Preferably, the online check contact signal sampling unit is arranged on the gas density relay body; or the online check contact signal sampling unit is arranged on the gas circuit cut-off pressure regulating mechanism.

Preferably, the online verification contact signal sampling unit comprises a first connecting circuit and a second connecting circuit, the first connecting circuit is connected with the contact of the gas density relay body and the contact signal control loop, and the second connecting circuit is connected with the contact of the gas density relay body and the intelligent control unit;

in a non-verification state, the second connection circuit is opened, and the first connection circuit is closed; under the check-up state, online check-up contact signal sampling unit cuts off first connecting circuit, intercommunication second connecting circuit will the contact of gas density relay body with the intelligence is controlled the unit and is connected.

More preferably, the first connection circuit comprises a first relay, the second connection circuit comprises a second relay, the first relay is provided with at least one normally closed contact, the second relay is provided with at least one normally open contact, and the normally closed contact and the normally open contact maintain opposite switch states; the normally closed contact is connected in series in the contact signal control loop, and the normally open contact is connected to the contact of the gas density relay body; in a non-checking state, the normally closed contact is closed, the normally open contact is opened, and the gas density relay monitors the output state of the contact in real time; under the check-up state, normally closed contact disconnection, normally open contact is closed, the contact of gas density relay body passes through normally open contact with the intelligence is controlled the unit and is connected.

Preferably, the gas circuit cut-off pressure regulating mechanism further comprises a moisture treating agent, and the moisture treating agent is arranged in the first cavity or/and the second cavity of the gas circuit cut-off pressure regulating mechanism; more preferably, the moisture treatment agent includes one of an adsorbent and a desiccant.

Preferably, the gas circuit cut-off pressure regulating mechanism further comprises a filter member, and the filter member is arranged on the second connector.

Preferably, the online verification of the gas density relay or the gas density monitoring device is completed by at least two gas density relay bodies, at least two gas path cut-off and pressure-regulating mechanisms, at least two online verification contact signal sampling units, an intelligent control unit and a gas density detection sensor; alternatively, the first and second electrodes may be,

the online calibration method comprises the following steps that at least two gas density relay bodies, at least two gas circuit cut-off and pressure regulating mechanisms, at least two online calibration contact signal sampling units, at least two intelligent control units and a gas density detection sensor are used for completing online calibration of the gas density relay or the gas density monitoring device; alternatively, the first and second electrodes may be,

at least two gas density relay bodies, at least two gas circuit stop voltage regulating mechanisms, at least two online check contact signal sampling units, at least two gas density detection sensors and an intelligent control unit are used for completing the online check of the gas density relay or the gas density monitoring device.

The third aspect of the present application provides a method for verifying a gas density relay, including:

when the gas density relay or the gas density monitoring device is in a normal working state, the cut-off piece does not enter the first cavity, the first interface is communicated with the second interface, and the gas density relay or the gas density monitoring device monitors the gas density value in the electrical equipment;

the gas density relay or the gas density monitoring device is used for checking the gas density relay according to the set checking time or/and the checking instruction and the gas density value condition under the condition that the gas density relay is allowed to be checked:

the intelligent control unit controls the gas circuit cut-off and pressure regulating mechanism, a cut-off piece and a connecting piece of the gas circuit cut-off and pressure regulating mechanism move towards the direction of the second interface under the driving of the driving part, and the cut-off piece enters the first cavity to cut off the gas circuit between the first interface and the second interface so as to cut off the gas circuit between the gas density relay body and the electrical equipment; the stopping piece continues to move towards the direction of the second interface under the action of the driving part, the volume of an air chamber communicated with the first interface of the air path stopping pressure regulating mechanism changes, the pressure of the gas density relay body can be regulated, the gas pressure of the gas density relay body is slowly reduced, the gas density relay body generates contact action, the contact action is transmitted to the intelligent control unit through the online checking contact signal sampling unit, the intelligent control unit obtains a gas density value according to a pressure value and a temperature value when the contact acts, or directly obtains the gas density value, the contact signal action value of the gas density relay body is detected, and the checking work of the contact signal action value of the gas density relay body is completed;

after all contact signal check-up work accomplished, unit control gas circuit is controlled to intelligence is by voltage regulation mechanism, the gas circuit is by voltage regulation mechanism's cut-off piece, connecting piece remove to the direction of keeping away from the second interface under driver part's effect, cut-off piece and first cavity separation and keep away from, make gas density relay body and electrical equipment's gas circuit communicate each other.

Preferably, a method for verifying a gas density relay includes:

in a normal working state, the cut-off piece does not enter the first cavity, the first interface is communicated with the second interface, the gas density relay or the gas density monitoring device monitors the gas density value in the electrical equipment, and meanwhile, the gas density relay or the gas density monitoring device monitors the gas density value in the electrical equipment on line through the gas density detection sensor and the intelligent control unit;

the online check contact signal sampling unit is adjusted to a check state through the intelligent control unit, and in the check state, the online check contact signal sampling unit cuts off a control loop of a contact signal of the gas density relay body and connects the contact of the gas density relay body to the intelligent control unit;

the intelligent control unit drives the stopping piece and the connecting piece of the gas circuit stopping and pressure regulating mechanism to move towards the direction far away from the second interface, the gas pressure slowly rises, so that the contact resetting of the gas density relay body occurs, the contact resetting is transmitted to the intelligent control unit through the online checking contact signal sampling unit, the intelligent control unit obtains a gas density value according to a pressure value and a temperature value when the contact is reset, or directly obtains the gas density value, a contact signal return value of the gas density relay body is detected, and the checking work of the contact signal return value of the gas density relay body is completed;

after all the contact signal verification work is finished, the cut-off piece of the gas circuit cut-off pressure regulating mechanism continues to move towards the direction far away from the second interface under the driving of the driving part, the cut-off piece is separated from the first cavity and is far away from the first cavity, so that the gas circuit of the gas density relay body and the gas circuit of the electrical equipment are mutually communicated, the online verification contact signal sampling unit is adjusted to be in a working state, and the control loop of the contact signal of the gas density relay body recovers to be in a normal working state.

Preferably, the gas circuit cut-off pressure regulating mechanism further comprises a third cavity arranged between the first cavity and the second cavity, two ends of the third cavity are respectively communicated with the first cavity and the second cavity, and longitudinal sections of the second cavity, the third cavity and the first cavity are of a stepped gradually-reduced structure or a continuously-reduced structure; the other end of the connecting piece penetrates through the third cavity and the second cavity in sequence, extends out of the third interface and is connected with the driving part; a pressure change piece is arranged in the part, located in the second cavity, of the connecting piece in a penetrating mode, the pressure change piece can movably enter and exit the third cavity, and the pressure change piece is in sealing contact with the inner wall of the third cavity after entering the third cavity; the verification method comprises the following steps:

the intelligent control unit controls the gas circuit cut-off and pressure regulating mechanism, a cut-off part, a connecting part and a pressure change part of the gas circuit cut-off and pressure regulating mechanism move towards the direction of the second interface under the driving of the driving part, the cut-off part enters the first cavity to cut off the gas circuit between the first interface and the second interface, and the gas circuit between the gas density relay body and the electrical equipment is cut off;

the gas path cut-off pressure regulating mechanism is communicated with the first interface, the volume of a gas chamber is slowly increased along with the movement of the cut-off piece, the pressure of the gas density relay body is further regulated to slowly reduce the gas pressure of the gas density relay body, so that the gas density relay body generates contact action, the contact action is transmitted to the intelligent control unit through the online checking contact signal sampling unit, the intelligent control unit obtains a gas density value according to a pressure value and a temperature value during contact action or directly obtains the gas density value, detects a contact signal action value of the gas density relay body, and completes the checking work of the contact signal action value of the gas density relay body; after the pressure change member enters the third cavity, the volume of an air chamber communicated with the first interface by the air path cut-off pressure regulating mechanism is rapidly increased along with the movement of the pressure change member, so that the gas pressure of the air chamber cut-off pressure regulating mechanism is rapidly reduced, the gas density relay body generates zero position contact action, the zero position contact action is transmitted to the intelligent control unit through the online check contact signal sampling unit, the intelligent control unit detects a zero position contact signal action value of the gas density relay body according to a pressure value when the zero position contact is acted, and the check work of the zero position contact signal action value of the gas density relay body is completed;

after all contact signal check-up work accomplished, unit control gas circuit is controlled to intelligence is by pressure regulating mechanism, the gas circuit is by stopping piece, connecting piece and the pressure change piece of pressure regulating mechanism and moving to the direction of keeping away from the second interface under driver part's effect, stops the piece and separates and keep away from with first cavity, makes gas density relay body and electrical equipment's gas circuit communicate each other.

More preferably, in a normal working state, the blocking piece does not enter the first cavity, the first interface is communicated with the second interface, the gas density relay or the gas density monitoring device monitors the gas density value in the electrical equipment, and meanwhile, the gas density relay or the gas density monitoring device monitors the gas density value in the electrical equipment on line through the gas density detection sensor and the intelligent control unit;

the intelligent control unit drives the cut-off piece of the gas circuit cut-off pressure regulating mechanism, the connecting piece and the pressure change piece to move towards the direction far away from the second interface, so that the gas pressure slowly rises, the contact point resetting of the gas density relay body is realized, the contact point resetting is transmitted to the intelligent control unit through the online checking contact point signal sampling unit, the intelligent control unit obtains a gas density value according to a pressure value and a temperature value when the contact point is reset, or directly obtains the gas density value, the contact point signal return value of the gas density relay body is detected, and the checking work of the contact point signal return value of the gas density relay body is completed;

after all the contact signal checking works are completed, the stopping piece, the connecting piece and the pressure changing piece of the gas circuit stopping and pressure regulating mechanism continue to move towards the direction far away from the second interface, the stopping piece is separated from the first cavity and is far away from the first cavity, so that the gas circuit of the gas density relay body and the gas circuit of the electrical equipment are mutually communicated, the online checking contact signal sampling unit is adjusted to be in a working state, and the control loop of the contact signal of the gas density relay body recovers to be in a normal working state.

Preferably, the gas path cut-off pressure regulating mechanism further comprises a fourth cavity and a fifth cavity which are arranged between the first cavity and the second cavity, the first cavity, the fourth cavity, the fifth cavity and the second cavity are sequentially communicated, the cross-sectional specification of the fourth cavity is larger than that of the first cavity, and the cross-sectional specification of the fifth cavity is smaller than that of the first cavity; the other end of the connecting piece penetrates through the fourth cavity, the fifth cavity and the second cavity in sequence, extends out of the third interface and then is connected with the driving part; a second pressure change piece penetrates through the part, located in the second cavity, of the connecting piece, the second pressure change piece can movably enter and exit the fifth cavity, and the second pressure change piece is in sealing contact with the inner wall of the fifth cavity after entering the fifth cavity; the verification method comprises the following steps:

the intelligent control unit controls the gas circuit cut-off and pressure-regulating mechanism, a cut-off piece, a connecting piece and a second pressure change piece of the gas circuit cut-off and pressure-regulating mechanism move towards the direction of the second interface under the driving of the driving part, the cut-off piece enters the first cavity to cut off the gas circuit between the first interface and the second interface, and the gas circuit between the gas density relay body and the electrical equipment is cut off;

the stopping piece continues to move towards the direction of the second interface under the action of the driving part, and before the second pressure changing piece enters the fifth cavity, the volume of an air chamber communicated with the first interface by the air path stopping and pressure regulating mechanism is rapidly increased along with the movement of the stopping piece, so that the pressure of the gas density relay body is regulated, and the gas pressure of the gas density relay body is rapidly reduced; after the second pressure changing part enters the fifth cavity, the volume of an air chamber communicated with the first interface by the air path cut-off pressure regulating mechanism is slowly increased along with the movement of the second pressure changing part, so that the gas density relay body generates contact action, the contact action is transmitted to the intelligent control unit through the online checking contact signal sampling unit, the intelligent control unit obtains a gas density value according to a pressure value and a temperature value when the contact is acted, or directly obtains the gas density value, the contact signal action value of the gas density relay body is detected, and the checking work of the contact signal action value of the gas density relay body is completed;

after all contact signal check-up work accomplished, unit control gas circuit is controlled to intelligence is by pressure regulating mechanism, the gas circuit is by stopping piece, connecting piece and the second pressure change piece of pressure regulating mechanism and moving in the direction of keeping away from the second interface under driver part's effect, stops the piece and separates and keep away from with first cavity, makes gas density relay body and electrical equipment's gas circuit communicate each other.

Preferably, in a normal working state, the cut-off piece does not enter the first cavity, the first interface is communicated with the second interface, the gas density relay or the gas density monitoring device monitors the gas density value in the electrical equipment, and meanwhile, the gas density relay or the gas density monitoring device monitors the gas density value in the electrical equipment on line through the gas density detection sensor and the intelligent control unit;

the intelligent control unit drives the cut-off piece of the gas circuit cut-off pressure regulating mechanism, the connecting piece and the second pressure change piece to move towards the direction far away from the second interface, so that the gas pressure rises, the contact resetting of the gas density relay body is realized, the contact resetting is transmitted to the intelligent control unit through the online checking contact signal sampling unit, the intelligent control unit obtains a gas density value according to a pressure value and a temperature value when the contact is reset, or directly obtains the gas density value, the contact signal return value of the gas density relay body is detected, and the checking work of the contact signal return value of the gas density relay body is completed;

after all the contact signal checking works are completed, the stopping piece, the connecting piece and the second pressure changing piece of the gas circuit stopping and pressure regulating mechanism continue to move towards the direction far away from the second interface, the stopping piece is separated from the first cavity and far away from the first cavity, so that the gas circuit of the gas density relay body and the gas circuit of the electrical equipment are mutually communicated, the online checking contact signal sampling unit is adjusted to be in a working state, and the control loop of the contact signal of the gas density relay body recovers to run in a normal working state.

Preferably, the contact signal comprises an alarm, and/or a latch.

Preferably, after the gas density relay is checked, if the gas density relay is abnormal, an alarm can be automatically sent out and uploaded to a remote end or sent to a designated receiver.

Preferably, the verification method further comprises: and displaying the gas density value and the verification result on site or on the background.

Preferably, the verification method further comprises: the intelligent control unit is controlled through field control and/or background control.

Compared with the prior art, the technical scheme of the invention has the following beneficial effects:

the application provides a maintenance-free gas density relay and a calibration method thereof, which are used for high-voltage and medium-voltage electrical equipment and comprise a gas density relay body, a gas density detection sensor, a gas circuit cut-off pressure regulating mechanism, an online calibration contact signal sampling unit and an intelligent control unit. Unit control gas circuit is controlled to intelligence is by pressure regulating mechanism the gas circuit is by under pressure regulating mechanism's driver part's effect, the gas circuit is closed to the cut-off piece, and simultaneously, along with the removal of cut-off piece, the gas chamber volume that the gas circuit was by pressure regulating mechanism changes for thereby the gas pressure of gas density relay body slowly descends and takes place the contact action, thereby the intelligence is controlled the density value when the unit moves according to the contact and is detected out warning and/or shutting contact signal action value and/or return value, do not need the fortune dimension personnel to on-the-spot check-up and maintain density relay, the reliability of electric wire netting has been improved greatly simultaneously, and the cost is reduced. Particularly, the gas circuit is directly closed by the cut-off piece and the pressure is adjusted, so that the gas density relay has better sealing performance, smaller volume, higher reliability and longer service life when in operation and verification, and the maintenance-free gas density relay can be realized. SF is realized in the whole checking process at the same time₆Zero emission of gas, environmental protection regulation requirements, green power grid construction and wide application.

Drawings

The accompanying drawings, which are incorporated in and constitute a part of this application, illustrate embodiments of the application and, together with the description, serve to explain the application and are not intended to limit the application. In the drawings:

fig. 1 is a schematic structural diagram of a maintenance-free gas density relay according to a first embodiment in an operating state;

FIG. 2 is a schematic structural diagram of the maintenance-free gas density relay in the online verification state according to the first embodiment;

FIG. 3 is a schematic circuit diagram of a maintenance-free gas density relay according to the first embodiment;

fig. 4 is a schematic structural diagram of the maintenance-free gas density relay according to the second embodiment in an operating state;

FIG. 5 is a schematic structural diagram of a maintenance-free gas density relay according to a third embodiment in an operating state;

FIG. 6 is a schematic structural diagram of a maintenance-free gas density relay according to a fourth embodiment in an operating state;

FIG. 7 is a schematic structural diagram of a maintenance-free gas density relay according to the fifth embodiment in an operating state;

FIG. 8 is a schematic structural diagram of the maintenance-free gas density relay in the online verification state according to the fifth embodiment;

fig. 9 is a schematic structural view of the maintenance-free gas density relay of the sixth embodiment in an operating state;

FIG. 10 is a schematic structural diagram of the maintenance-free gas density relay according to the sixth embodiment in the on-line verification state;

FIG. 11 is a schematic structural view of a maintenance-free gas density relay according to the seventh embodiment in an operating state;

FIG. 12 is a schematic structural view of the maintenance-free gas density relay of the seventh embodiment in the on-line verification state;

fig. 13 is a schematic structural diagram of the maintenance-free gas density relay according to the seventh embodiment in the on-line verification state.

Detailed Description

In order to make the objects, technical solutions and effects of the present invention clearer and clearer, the present invention is further described in detail below with reference to the accompanying drawings and examples. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

The first embodiment is as follows:

as shown in fig. 1 and 2, a maintenance-free gas density relay or gas density monitoring device includes: the gas density relay comprises a gas density relay body 1, gas density detection sensors (a pressure sensor 2 and a temperature sensor 3), a gas circuit cut-off pressure regulating mechanism 5, an online checking contact signal sampling unit 6 and an intelligent control unit 7. Wherein, pressure sensor 2, temperature sensor 3, online check-up contact signal sampling unit 6 and intelligence are controlled unit 7 and are set up on gas density relay body 1, pressure sensor 2, temperature sensor 3, online check-up contact signal sampling unit 6 and gas circuit are by pressure regulating mechanism 5 and are connected with intelligence control unit 7 respectively.

Specifically, the air path cut-off pressure regulating mechanism 5 includes a housing 51, and a first cavity 53A and a second cavity 53C which are communicated with each other in the housing 51, and a cross-sectional specification of the first cavity 53A is smaller than a cross-sectional specification of the second cavity 53C; the front wall of the first cavity 53A is provided with a second interface 511 connected with the electrical equipment 8, the side wall of the second cavity 53C is provided with a first interface 510 communicated with the air passage of the gas density relay body 1, and one end of the second cavity 53C, which is far away from the first cavity 53A, is provided with a third interface 513. A stopping element 52 is arranged in the second cavity 53C, the stopping element 52 can move in and out of the first cavity 53A, and the stopping element 52 is in sealing contact with the inner wall of the first cavity 53A through a sealing element 521 after entering the first cavity 53A, the sealing element 521 is usually made of rubber and can be embedded or vulcanized on the stopping element 52 to block an air passage between the first connector 510 and the second connector 511. The stopping member 52 is disposed at one end of a connecting member 54, and the other end of the connecting member 54 penetrates through the second cavity 53C, extends from the third port 513, and is connected to a driving member 58. In a preferred embodiment, a portion of the connecting member 54 penetrating the third port 513 is provided with a connecting member seal 541, and an outer surface of the connecting member 54 is in sealing contact with the third port 513 from which the connecting member 54 extends through the connecting member seal 541. The driving part 58 drives the stopping piece 52 to move in the first cavity 53A and the second cavity 53C through the connecting part 54, so that the stopping piece 52 is accommodated in the first cavity 53A to block the second port 511 and block the air passage between the electrical equipment 8 and the gas density relay body 1 (i.e. the stopping piece 52 is closed), or the stopping piece 52 is separated and far away from the first cavity 53A to communicate the first port 510 and the second port 511, i.e. to communicate the air passage between the electrical equipment 8 and the gas density relay body 1 (i.e. the stopping piece 52 is opened). Meanwhile, the gas pressure in the gas path cut-off pressure regulating mechanism 5 changes with the position change of the cut-off piece 52, and is used for regulating the pressure rise and fall of the gas density relay body 1 communicated with the second cavity 53C, so that the gas density relay body 1 generates contact signal action. The driving component 58 may be one of a magnetic force, a motor, an electric push rod motor, a stepping motor, a reciprocating mechanism, a carnot cycle mechanism, an air compressor, a deflation valve, a pressure pump, a booster valve, an electric air pump, an electromagnetic air pump, a pneumatic element, a magnetic coupling thrust mechanism, a heating thrust mechanism, an electric heating thrust mechanism, and a chemical reaction thrust mechanism. The heating produces the thrust mechanism, for example, heats the bimetallic strip, and then produces the thrust mechanism.

In this embodiment, a fixing guide 515 is disposed in the second cavity 53C, the fixing guide 515 is perpendicular to the axial direction of the connecting part 54, and a guide hole for the connecting part 54 to pass through is disposed on the fixing guide 515. The fixed guide 515 is mainly used for guiding the movement of the connecting part 54, so that the connecting part 54 can be stable and reliable in movement.

As shown in fig. 3, in the present application, the gas density relay body 1 includes various gas density relays, the intelligent control unit 7 is mainly composed of a processor 71(U1), a power supply 72(U2), the processor 71(U1) may be a general-purpose computer, an industrial personal computer, a CPU, a single chip microcomputer, an ARM chip, an AI chip, an MCU, an FPGA, a P L C, etc., an industrial control motherboard, an embedded main control board, etc., and other intelligent integrated circuits, the power supply 72(U2) may be a switching power supply, an ac 220V, a dc power supply, L DO, a programmable power supply, solar energy, a storage battery, a rechargeable battery, a battery, an electric field induction power supply, a magnetic field induction power supply, a wireless rechargeable power supply, a capacitor power supply, etc., the pressure sensor 2 may be of a type such as an absolute pressure sensor, a relative pressure sensor, or an absolute pressure sensor and a relative pressure sensor, and the number of the pressure sensor may be several, and the temperature sensor 3 may be a thermocouple, a resistor, a semiconductor, a non.

The basic requirements or functions of the intelligent control unit 7 are as follows: accomplish the control and the signal acquisition of gas circuit by pressure regulating mechanism 5 through intelligence accuse unit 7, realize: closing the stopping piece 52, and further turning off the gas path of the gas density relay body 1 and the electrical equipment 8 during verification; can detect the pressure value and temperature value when the contact signal of the gas density relay body 1 acts, and convert the pressure value and temperature value into the corresponding pressure value P at 20 DEG C₂₀(density value), that is, the contact operating value P of the gas density relay body 1 can be detected_D20To complete the calibration of the gas density relay body 1, or to directly detect the density value P when the contact signal of the gas density relay body 1 acts_D20And the calibration work of the gas density relay body 1 is completed. Meanwhile, the self-checking work among the gas density relay body 1, the pressure sensor 2 and the temperature sensor 3 can be completed through the test of the rated pressure value of the gas density relay body 1, so that the maintenance-free operation is realized.

The online check contact signal sampling unit 6 mainly completes the contact signal sampling of the gas density relay body 1. Namely, the basic requirements or functions of the online verification contact signal sampling unit 6 are as follows: 1) the safe operation of the electrical equipment is not influenced during the verification, namely, during the verification, the safe operation of the electrical equipment is not influenced when the contact signal of the gas density relay body 1 acts; 2) the contact signal control loop of the gas density relay body 1 does not influence the performance of the gas density relay, particularly does not influence the performance of the intelligent control unit 7, and does not damage the gas density relay or influence the test operation. Specifically, as shown in fig. 3, the online verification contact signal sampling unit 6 includes a first connection circuit and a second connection circuit, the first connection circuit connecting the contact P of the gas density relay body 1_JA control circuit connected with the contact point P of the gas density relay body 1, and a second connecting circuit_JAnd the intelligent control unit 7. In thatIn a non-verification state, the second connecting circuit is disconnected, and the first connecting circuit is closed; in a checking state, the on-line checking contact signal sampling unit 6 cuts off the first connecting circuit, connects the second connecting circuit and connects the contact P of the gas density relay body 1_JIs connected with the intelligent control unit 7.

The gas density relay body 1, the pressure sensor 2, the temperature sensor 3, the gas circuit stop pressure regulating mechanism 5, the online checking contact signal sampling unit 6 and the intelligent control unit 7 can be flexibly arranged as required. For example, the gas density relay body 1, the pressure sensor 2, and the temperature sensor 3 may be provided together; or the pressure sensor 2 and the gas-circuit shutoff pressure-regulating mechanism 5 may be provided together. In short, the arrangement between them can be flexibly arranged and combined.

The working principle of the maintenance-free gas density relay or gas density monitoring device is as follows:

as shown in fig. 1, in the operating state, the intelligent control unit 7 monitors the gas pressure and temperature of the electrical device 8 according to the pressure sensor 2 and the temperature sensor 3 to obtain the corresponding 20 ℃ pressure value P₂₀(i.e., gas density values, i.e., on-line monitoring of gas density values). The cut-off piece 52 of the gas path cut-off pressure regulating mechanism 5 is arranged in the second cavity 53C and does not enter the first cavity 53A, the second interface 511 is communicated with the gas path of the first interface 510, so that the gas density relay body 1 is communicated with the electrical equipment 8 on the gas path in the working state, and the gas density relay body 1 monitors the gas density of the electrical equipment 8 safely, so that the electrical equipment 8 works safely and reliably.

When the gas density relay body 1 needs to be checked, if the gas density value P is detected at the moment₂₀Not less than set safety check density value P_SThe gas density relay (or the density monitoring device) sends out a command, that is, the intelligent control unit 7 drives the driving component 58 of the gas circuit cut-off pressure regulating mechanism 5, so that the driving component 58 pushes the connecting piece 54 and the cut-off piece 52 to move towards the direction of the second interface 511. As shown in fig. 2, when the movement is performed to a certain extent, the stopping piece 52 enters the first cavity 53A to block the second port 511, that is, the stopping piece 52 closes the air passage of the second port 511, thereby shutting off the air passageThe gas circuit between body density relay body 1 and electrical equipment 8 to through the control circuit of the contact signal that online check-up contact signal sampling unit 6 cut off gas density relay, be connected to intelligence accuse unit 7 with the contact of gas density relay body 1.

With the continuous motion toward second interface 511 of cut-off 52 under the effect of driver part 58, the volume of the air chamber that the inner wall of cut-off 52 and first cavity 53A, the inner wall of second cavity 53C enclose changes, can adjust the pressure of gas density relay body 1 makes its gas pressure slowly descend for gas density relay body 1 takes place the contact action, its contact action transmits to intelligence accuse unit 7 through online check-up contact signal sampling unit 6, intelligence accuse unit 7 is according to pressure value P and the temperature value T that temperature sensor 3 gathered of pressure sensor 2 gathered when the contact action, and then obtains gas density value P through the calculation₂₀Or directly obtaining the gas density value P₂₀Detecting the contact signal operating value P of the gas density relay body 1_D20Thereby completing the verification work of the contact signal action value of the gas density relay. Namely, the intelligent control unit 7 converts the pressure value P corresponding to 20 ℃ according to the gas pressure-temperature relation characteristic₂₀(density value), the contact point action value P of the gas density relay body 1 can be detected_D20。

Treat that the whole backs that detect of contact action value of gas density relay body 1's warning and/or blocking signal, 7 drive gas circuits of rethread intelligence accuse unit 58 drive gas circuit stop actuating mechanism 58 of pressure regulating mechanism 5, stop 52 under the effect of driver part 58 toward the direction motion of second cavity 53C, can adjust the pressure of gas density relay body 1 makes its gas pressure rise slowly for gas density relay body 1 takes place the contact and resets, and the contact resets and transmits intelligence accuse unit 7 through online check-up contact signal sampling unit 6, and pressure value P, temperature value T when intelligence accuse unit 7 resets according to the contact obtain gas density value P₂₀Or directly obtaining the gas density value P₂₀Detecting the contact signal return value P of the gas density relay_F20Completing the contact signal return value P of the gas density relay_F20The verification work of (2). The verification can be repeated for a plurality of times (for example, 2 to 3 times) and then the average value thereof is calculated, thus completing the verification work of the gas density relay body 1.

After all the contact signal verification work is completed, the intelligent control unit 7 controls the air path cut-off pressure regulating mechanism 5, the cut-off piece 52 of the air path cut-off pressure regulating mechanism 5 moves rightwards (i.e. in the direction away from the second interface 511) under the action of the driving part 58, so that the cut-off piece 52 moves out of the first cavity 53A to the second cavity 53C, i.e. the cut-off piece 52 does not block the second interface 511 any more, and the air paths of the electrical equipment 8 and the gas density relay body 1 are communicated with each other. Meanwhile, the online check contact signal sampling unit 6 is adjusted to be in a working state, and a control loop of the contact signal of the gas density relay body 1 is restored to be in a normal working state. As shown in fig. 1: at this time, the cut-off piece 52 is opened, the gas density relay body 1 is communicated with the electrical equipment 8 on the gas path, and the gas density of the gas chamber 8 of the electrical equipment is normally monitored by the gas density relay body 1, and the gas density of the electrical equipment 8 can be monitored on line. That is, the density monitoring circuit of the gas density relay body 1 works normally, and the gas density of the electrical equipment 8 is monitored safely by the gas density relay body 1, so that the electrical equipment 8 works safely and reliably, and maintenance-free operation is realized.

After the gas density relay body 1 completes the checking work, the gas density relay or the gas density monitoring device judges and can inform the detection result, and the mode is flexible. In a word, after the gas density relay finishes on-line verification work, if abnormity occurs, an alarm can be automatically sent out, and the alarm can be uploaded to a far end.

Example two:

as shown in fig. 4, the working principle is the same as that of the first embodiment, and is not described herein again. The difference of this embodiment from the first embodiment is:

1) the gas circuit is still equipped with fourth interface 516 on ending the pressure regulating mechanism 5, pressure sensor 2, temperature sensor 3, online check-up contact signal sampling unit 6 and intelligent control unit 7 set up on the fourth interface 516 of gas circuit ending the pressure regulating mechanism 5.

2) The driving part 58 and the part of the connecting part 54 extending out of the third port 513 are sealed in a cavity 517 (or a housing), and the cavity 517 (or the housing) is hermetically connected with the housing 51 of the air path shutoff pressure regulating mechanism 5, that is, the cavity 517 (or the housing) ensures that the air path shutoff pressure regulating mechanism 5 has good sealing performance.

3) In this embodiment, the gas circuit pressure-regulating stop mechanism 5 further includes a moisture treatment agent 10, and the moisture treatment agent 10 is disposed in the second cavity 53C of the gas circuit pressure-regulating stop mechanism, or may be disposed on the left side of the first cavity by improvement. Preferably, in this embodiment, the moisture treatment agent 11 includes one of an adsorbent and a desiccant. For example, an alumina molecular sieve (also called as an activated alumina desiccant) can be adopted to ensure that the moisture of the gas path cut-off pressure regulating mechanism is very tiny, so that the moisture of the electrical equipment is not increased or exceeded during the online verification process, and the moisture of the electrical equipment can be reduced.

4) In this embodiment, the air path shutoff pressure regulating mechanism 5 further includes a filter member 11, and the filter member 11 is disposed on (or near) the second interface 511. The filter element 11 can be one of a filter screen, a filter element and a filter, the filter screen 11 is adopted in this embodiment, and the filter screen 11 is arranged on the second interface 511, so that it is ensured that gas entering and exiting from the electrical equipment is clean, that is, it is ensured that the gas of the electrical equipment is not polluted in the online checking process, and the safe and reliable operation of the electrical equipment is ensured.

Example three:

as shown in fig. 5, the working principle is the same as that of the first embodiment, and is not described herein again. The difference of this embodiment from the first embodiment is:

1) the air path cut-off pressure regulating mechanism 5 further includes a sealing coupling piece 514, one end of the sealing coupling piece 514 is connected to the third interface 513 in a sealing manner, the other end of the sealing coupling piece 514 is connected to a sealing plate 5141 in a sealing manner, the sealing plate 5141 is connected to or abutted against the driving end of the driving part 58, or the sealing coupling piece 514 wraps the connecting part 54 and the driving part 58 in the sealing coupling piece 514 in a sealing manner. The connecting member 54 has one end connected to the stopper 52 and the other end connected to the driving part 58 through the sealing plate 5141 passing through the sealing coupling member 514. The sealing coupling 514 may be a bellows, or a sealing bladder, or a sealing ring, with a bellows being preferred in this embodiment.

2) The fixing guide 515 is disposed at the third interface 513, and is used for guiding the movement of the connecting element 54, so that the connecting element 54 can be stable and reliable in movement.

Example four:

as shown in fig. 6, the working principle is the same as that of the first embodiment, and is not described herein again. The difference between this embodiment and the third embodiment is:

1) the sealing coupling is constituted by a balloon 518. One end of the air bag 518 is hermetically connected with the third interface 513, the other end of the air bag 518 is hermetically connected with a coupling plate 542, and the coupling plate 542 is abutted against or connected with the driving end of the driving part 58.

2) The driving part 58, the air bag 518 and the part of the connecting part 54 extending out of the third port 513 are sealed in a cavity 517 (or a housing), and the cavity 517 (or the housing) is hermetically connected with the housing 51 of the air path shutoff pressure regulating mechanism 5, that is, the cavity 517 (or the housing) ensures that the air path shutoff pressure regulating mechanism 5 has good sealing performance.

Example five:

as shown in fig. 7 to 8, the difference of the first embodiment of the present invention is: the gas circuit is by pressure regulating mechanism 5 still including setting up first cavity 53A with third cavity 53B between the second cavity 53C, the both ends of third cavity 53B communicate with first cavity 53A and second cavity 53C respectively, the longitudinal section of second cavity 53C, third cavity 53B, first cavity 53A reduces the structure step by step or reduces the structure in succession for the notch cuttype. A pressure changing member 56 is disposed through a portion of the connecting member 54 located in the second cavity 53C, the pressure changing member 56 can move in and out of the third cavity 53B, and after entering the third cavity 53B, the pressure changing member 56 is in sealing contact with an inner wall of the third cavity 53B through a sealing member 55. The pressure changing member 56 is a piston or a seal spacer.

As shown in fig. 7, in the operating state, the blocking piece 52 does not enter the first cavity 53A, the gas path between the first port 510 and the second port 511 is communicated, that is, the gas path between the gas density relay body 1 and the electrical equipment 8 is communicated, and the gas density relay body 1 monitors the gas density of the electrical equipment 8 safely, so that the electrical equipment 8 operates safely and reliably.

As shown in fig. 8, when the gas density relay body 1 is verified, the blocking member 52 and the pressure changing member 56 are moved in the direction of the second port 511 by the driving member 58. The stopper 52 and the sealing member 521 are accommodated in the first cavity 53A to block the second port 511, and block the air path between the gas density relay body 1 and the electrical equipment 8.

The working principle of the case is as follows: the pressure-changing member 56 and the sealing member 55 move leftwards (towards the second port 511) before entering the third cavity 53B, and the stopping member 52 and the inner walls of the first cavity 53A, the third cavity 53B and the second cavity 53C form a sealed air chamber. Along with the movement of the stopping piece 52 and the sealing piece 521 in the first cavity 53A, the volume of the sealed air chamber changes slowly, the pressure of the gas density relay body 1 communicated with the second cavity 53C can be slowly adjusted, the gas pressure of the gas density relay body can be slowly reduced, the gas density relay body 1 generates contact action, the contact action is transmitted to the intelligent control unit 7 through the online checking contact signal sampling unit 6, the intelligent control unit 7 obtains a gas density value according to a pressure value and a temperature value when the contact acts, or directly obtains the gas density value, the contact signal action value of the gas density relay body 1 is detected, and the checking work of the contact signal action value of the gas density relay body 1 is completed; particularly, its gas pressure can descend slowly for gas density relay body 1 takes place the contact action, and its contact action transmits intelligent control unit 7 through online check-up contact signal sampling unit 6, and intelligent control unit 7 gathers pressure value P and temperature value T that temperature sensor 3 gathered according to contact action time gathering pressure sensor 2, and then obtains gas density value P through calculation₂₀Or directly obtaining the gas density value P₂₀Detecting the contact signal operating value P of the gas density relay body 1_D20Thereby completing the verification work of the contact signal action value of the gas density relay. Relay for measuring gas densityAfter the operation value checking operation of the contact signal of the body 1 is completed, the pressure changing member 56 and the sealing member 55 move leftwards to the third cavity 53B, the pressure changing member 56 is in sealing contact with the inner wall of the third cavity 53B through the sealing member 55, and a sealed air chamber is defined by the pressure changing member 56, the inner wall of the third cavity 53B and the inner wall of the second cavity 53C. Move left along with pressure change 56 and sealing member 55 continuation in third cavity 53B, this sealed air chamber's volume takes place great change, can adjust comparatively fast gas density relay body 1's pressure makes its gas pressure descend comparatively fast for gas density relay body 1 takes place zero position contact action (the zero position contact is equipped with by density relay body), zero position contact action transmits intelligent control unit 7 through online check contact signal sampling unit 6, pressure value (or density value) when intelligent control unit 7 moves according to the zero position contact, detect out gas density relay body 1's zero position contact signal action value, accomplish the check-up work of gas density relay body 1's zero position contact signal action value. The zero-position contact can also be a locking contact with a larger width than the alarm contact, or the zero-position contact is a comparison density value or comparison pressure value comparison contact attached to the density relay. In this embodiment, set up the pressure lift that can slowly adjust gas density relay body 1 through sliding in the pressure lift that stops 52 of first cavity 53A, set up in second cavity 53C through sliding, and can pass in and out third cavity 53B's pressure change 56 can the pressure lift of quick adjustment gas density relay body 1, the pressure regulating promptly can be wide big, and is fast to the demand of the butt joint check-up of gas density relay body has been realized. In the technical scheme of the embodiment, for some density relays needing to check the zero-position contact, before the rated pressure of the density relay acts on the zero-position contact, pressure adjustment can be performed in a slow pressure adjusting mode, and accurate checking of the alarm locking contact is performed. After the calibration of the alarm locking contact is completed, in order to greatly save time, the pressure is adjusted by adopting a rapid pressure adjusting mode, so that the pressure adjusting speed is high, and the calibration of the zero-position contact is completed quickly. Alternatively, for some density relays that require calibration of the comparison density value or comparison pressure value to calibrate the contact, the method is used inBefore the rated pressure of the density relay reaches the comparison density value or the comparison pressure value to correct the action of the contact, the pressure can be adjusted in a slow pressure adjusting mode to accurately check the alarm locking contact. After the verification of the alarm locking contact is completed, in order to greatly save time, the pressure is adjusted by adopting a rapid pressure adjusting mode, so that the pressure adjusting speed is high, and the verification of the comparison density value or the comparison pressure value for the verification of the contact is completed quickly. For example, the technical solution is applied to a density relay with such parameters: 0.6MPa (rated pressure), 0.55MPa (alarm pressure), 0.5MPa (locking pressure) and 0.0MPa (zero point contact), namely, the pressure can be slowly regulated from 0.6MPa (rated pressure) to 0.5MPa, and the pressure can be quickly regulated from 0.5MPa (rated pressure) to 0.0 MPa. Thus, the method has the outstanding advantages that: 1) the density relay which can check the diversity is greatly enriched (such as the density relay with a comparison density value or a comparison pressure value check contact, the density relay with a zero position contact, the density relay with the alarm contact and the locking contact with large width); 2) the time for online checking the density relay is saved. In addition, the gas path cutoff pressure regulating mechanism can further comprise a moisture treatment agent, and the moisture treatment agent is arranged in the second cavity 53C or/and the third cavity 53B of the gas path cutoff pressure regulating mechanism and is used for drying the checked gas.

Example six:

as shown in fig. 9 to 10, the working principle is the same as that of the fifth embodiment, and is not described herein again. The difference between this embodiment and the fifth embodiment is:

2) In this embodiment, the gas path shutoff pressure regulating device further includes a shutoff member on-off state monitor 9, and the shutoff member on-off state monitor 9 is disposed corresponding to the state monitor trigger 5142 of the gas path shutoff pressure regulating mechanism 5. In the working state, the second interface 511 is not blocked by the blocking piece 52, and the blocking piece switch state monitor 9 outputs a corresponding signal, so that the gas circuit of the gas density relay body 1 is communicated with the electrical equipment 8 in the working state, and the safe operation of a power grid is not influenced. The signal is connected with the intelligent control unit 7 and can be uploaded to a target device (such as a background). Wherein the shut-off switch status monitor 9 includes, but is not limited to, one of a travel switch, a micro switch, a push button, an electric switch, a displacement switch, and an electromagnetic relay.

In addition, in this embodiment, there may be two pressure sensors, which are respectively a first pressure sensor and a second pressure sensor; the temperature sensors can be two, namely a first temperature sensor and a second temperature sensor. The present embodiment provides a plurality of pressure sensors and temperature sensors for the purpose of: the pressure values monitored by the first pressure sensor and the second pressure sensor can be compared and verified mutually; the temperature values monitored by the first temperature sensor and the second temperature sensor can be compared and verified with each other; the density value P1 obtained by monitoring the first pressure sensor and the first temperature sensor₂₀A density value P2 monitored with the second pressure sensor and the second temperature sensor₂₀Comparing and checking each other; even the density value Pe of the rated value of the gas density relay body 1 can be checked and obtained on line₂₀And comparing and checking each other. The arrangement of the pressure sensors and the temperature sensors can further ensure the reliability of the density relay or the density monitoring device, and the density relay or the density monitoring device can be automatically monitored and compared to realize maintenance-free operation. The method comprises the steps of judging by utilizing data monitored by a mechanical density relay and an electronic part sensor (a pressure sensor and a temperature sensor) during verification and the variation trend of corresponding difference values between different periods, and if the variation trend is within an allowable range, judging by using a gas density relay or a gas density relay monitoring deviceIs in a normal state. For example, the alarm (or lockout) action value is P in 2020 verification_bj2020(P_bs2020) The alarm (or locking) action value is P in 2021 year check_bj2021(P_bs2021) The alarm (or locking) action value is P in 2022 year check_bj2022(P_bs2022) The change trend of the alarm (or locking) action value can be known, the judgment is carried out according to the change trend, and if the change trend is within the allowable range, the gas density relay or the gas density relay monitoring device is in a normal state. The method can check and compare the variation trend of the temperature values at different periods under the condition that the temperature values are close, and more accurate judgment and analysis are carried out. Meanwhile, the embodiment can also comprise a micro-water sensor for monitoring the micro-water content of the electrical equipment and a decomposition product sensor for monitoring the decomposition product content.

In addition, the technical product of this application can also have the safety protection function, specifically be: 1) when the density value obtained by monitoring the first pressure sensor and the first temperature sensor or the second pressure sensor and the second temperature sensor is lower than a set value, the gas density relay automatically does not check the gas density relay body any more and sends out an announcement signal.

Example seven:

as shown in fig. 11 to 13, the difference of the present embodiment from the first embodiment is: the air path stop pressure regulating mechanism 5 further comprises a fourth cavity 53D and a fifth cavity 53E which are arranged between the first cavity 53A and the second cavity 53C, and the first cavity 53A, the fourth cavity 53D, the fifth cavity 53E and the second cavity 53C are sequentially communicated. The cross-sectional specification of the fourth cavity 53D is greater than that of the first cavity 53A, and the cross-sectional specification of the fifth cavity 53E is smaller than that of the first cavity 53A. A pressure changing member 56 is disposed through a portion of the connecting member 54 located in the second cavity 53C, the pressure changing member 56 can move in and out of the fifth cavity 53E, and after entering the fifth cavity 53E, the pressure changing member 56 is in sealing contact with an inner wall of the fifth cavity 53E through a sealing member 55. The pressure changing member 56 is a piston or a seal spacer.

The working principle of the case is as follows: as shown in fig. 11, in the operating state, the blocking piece 52 does not enter the first cavity 53A, the gas path between the first port 510 and the second port 511 is communicated, that is, the gas path between the gas density relay body 1 and the electrical equipment 8 is communicated, and the gas density relay body 1 monitors the gas density of the electrical equipment 8 safely, so that the electrical equipment 8 operates safely and reliably.

As shown in fig. 12, when the gas density relay body 1 is verified, the blocking member 52 and the pressure changing member 56 are moved in the direction of the second port 511 by the driving member 58. The stopper 52 and the sealing member 521 are accommodated in the first cavity 53A to block the second port 511, and block the air path between the gas density relay body 1 and the electrical equipment 8.

The pressure changing member 56 and the sealing member 55 move leftwards (towards the second port 511) to enter the fifth cavity 53E, and a sealed air chamber is defined by the stopping member 52, the inner wall of the first cavity 53A, the inner wall of the fourth cavity 53D, the inner wall of the fifth cavity 53E and the inner wall of the second cavity 53C. With the movement of the stopper 52 and the sealing member 521 in the first cavity 53A, the volume of the sealed air chamber is largely changed, and the pressure of the gas density relay body 1 communicating with the second cavity 53C can be quickly adjusted, so that the gas pressure thereof can be significantly reduced.

As shown in fig. 13, when the gas pressure value of the gas density relay body 1 approaches the contact operating value of the gas density relay body 1, the pressure changing member 56 and the sealing member 55 move leftward into the fifth cavity 53E, the pressure changing member 56 is in sealing contact with the inner wall of the fifth cavity 53E through the sealing member 55, and a sealed air chamber is defined between the pressure changing member 56 and the inner walls of the fifth cavity 53E and the second cavity 53C. With the pressure change piece 56 and the sealing piece 55 moving leftwards continuously in the fifth cavity 53E, the volume of the sealed air chamber changes slightly, the pressure of the gas density relay body 1 can be adjusted slowly, the gas pressure of the gas density relay body is reduced slowly, so that the gas density relay body 1 generates contact action, the contact action is transmitted to the intelligent control unit 7 through the online checking contact signal sampling unit 6, and the intelligent control unit 7 transmits the pressure value P acquired by the pressure sensor 2 and the temperature acquired by the temperature sensor 3 according to the contact actionThe value T is calculated to obtain a gas density value P₂₀Or directly obtaining the gas density value P₂₀Detecting the contact signal operating value P of the gas density relay body 1_D20Thereby completing the verification work of the contact signal action value of the gas density relay.

In this embodiment, the pressure rise and fall of the gas density relay body 1 can be rapidly adjusted by the stopping member 52 arranged in the first cavity 53A in a sliding manner, the pressure rise and fall of the gas density relay body 1 can be slowly adjusted by the pressure changing member 56 arranged in the second cavity 53C in a sliding manner and capable of entering and exiting the fifth cavity 53E, that is, the pressure adjustment precision is controllable, and therefore accurate calibration of the gas density relay body 1 is achieved. In the technical scheme of the embodiment, before the rated pressure of the density relay acts on the alarm contact, the pressure can be adjusted in a rapid pressure adjusting mode, so that the time is greatly saved, and when the density relay acts on the vicinity of the alarm contact, the pressure can be adjusted in a slow pressure adjusting mode, so that the pressure adjusting speed is slow, and the detection precision is fully ensured. For example, the technical solution is applied to a density relay with such parameters: 0.6MPa (rated pressure), 0.52MPa (alarm pressure) and 0.5MPa (locking pressure). Namely, the pressure can be adjusted from 0.6MPa (rated pressure) to 0.53MPa quickly, and from 0.53MPa (rated pressure) to 0.50MPa slowly. Thus, the method has the outstanding advantages that: 1) the time for checking the density relay on line is saved; 2) the detection precision of the on-line check density relay is improved; 3) the requirement of the intelligent control unit on the control speed of the driving part is reduced, so that the intelligent control unit is simple to control and is more reliable. In addition, the gas path cutoff pressure regulating mechanism may further include a moisture treatment agent, which is disposed in the second cavity 53C or/and the fourth cavity 53D of the gas path cutoff pressure regulating mechanism and performs drying treatment on the verified gas.

It should be noted that, a maintenance-free gas density relay generally means that its constituent elements are designed into an integral structure; the gas density monitoring device generally refers to a device whose components are designed into a split structure and flexibly assembled. And a first interface communicated with the gas path of the gas density relay body is arranged on the side wall of the second cavity, or a first interface communicated with the gas path of the gas density relay body is arranged on the right side of the second cavity. In addition, in the technical scheme of the invention, the gas density relay body (or the multi-way connector) can utilize the existing operating gas density relay (or the multi-way connector) of the transformer substation, namely, the technical scheme of the invention is utilized to carry out technical transformation on the operating density relay of the transformer substation, so that the technology is upgraded, maintenance is avoided, the operation and maintenance cost is reduced, and the reliability of a power grid is improved.

In summary, according to the maintenance-free gas density relay and the calibration method thereof provided by the invention, the installation positions of the gas density relay body, the pressure sensor, the temperature sensor, the gas path cut-off pressure regulating mechanism, the online calibration contact signal sampling unit and the intelligent control unit can be flexibly combined. For example: the gas density relay body, the pressure sensor, the temperature sensor, the online check contact signal sampling unit and the intelligent control unit can be combined together, integrally designed and also can be designed in a split mode; can be arranged on the shell or on the multi-way joint, and can also be connected together through a connecting pipe. In short, the structure is not limited. This application has adopted the gas circuit that contains the shutoff piece to end pressure regulating mechanism, has solved the problem that the gas circuit was turn-offed and pressure regulation for during operation and check-up, need not automatically controlled valve, its sealing performance is better, and the volume is littleer, and the reliability is higher, and the life-span is longer, can realize the non-maintaining of gas density relay. At the same time, the whole checking process realizes SF₆The gas zero emission is realized, the requirements of environmental protection regulations are met, the construction of a green power grid is met, and the wide application is facilitated.

The embodiments of the present invention have been described in detail, but the embodiments are merely examples, and the present invention is not limited to the embodiments described above. Any equivalent modifications and substitutions to those skilled in the art are also within the scope of the present invention. Accordingly, equivalent changes and modifications made without departing from the spirit and scope of the present invention should be covered by the present invention.

Claims

1. A maintenance-free gas density relay, comprising: the gas density relay comprises a gas density relay body, a gas density detection sensor, a gas circuit cut-off pressure regulating mechanism, an online check contact signal sampling unit and an intelligent control unit;

wherein the contact signal comprises an alarm, and/or a latch.

2. A maintenance-free gas density monitoring device, comprising: the gas density relay comprises a gas density relay body, a gas density detection sensor, a gas circuit cut-off pressure regulating mechanism, an online check contact signal sampling unit and an intelligent control unit;

wherein the contact signal comprises an alarm, and/or a latch.

3. The gas density relay of claim 1 or the gas density monitoring device of claim 2, wherein: the gas circuit is still equipped with fixed guide by pressure regulating mechanism, fixed guide locates in the second cavity, perhaps locate the third kneck, fixed guide perpendicular to the axial setting of connecting piece, just be equipped with the confession on the fixed guide the guiding hole that the connecting piece passed.

4. The gas density relay of claim 1 or the gas density monitoring device of claim 2, wherein: the outer diameter of the connecting piece is smaller than the inner diameter of the first cavity.

5. The gas density relay of claim 1 or the gas density monitoring device of claim 2, wherein: the stop member is a piston or a sealing spacer.

6. The gas density relay of claim 1 or the gas density monitoring device of claim 2, wherein: the outer surface of the connecting piece is in sealing contact with the third interface from which the connecting piece extends.

7. The gas density relay of claim 1 or the gas density monitoring device of claim 2, wherein: the air path stopping and pressure regulating mechanism further comprises a sealing connecting piece, one end of the sealing connecting piece is connected with the third interface in a sealing mode, the other end of the sealing connecting piece is connected with the driving end of the driving part in a sealing mode, or the sealing connecting piece enables the connecting piece and the driving part to be wrapped in the sealing connecting piece in a sealing mode.

8. The gas density relay or gas density monitoring device of claim 7, wherein: the sealing coupling includes one of a bellows, a sealing bladder, and a sealing ring.

9. The gas density relay of claim 1 or the gas density monitoring device of claim 2, wherein: the driving part comprises one of a magnetic force mechanism, a motor, an electric push rod motor, a stepping motor, a reciprocating motion mechanism, a Carnot cycle mechanism, an air compressor, a vent valve, a pressure making pump, a booster valve, an electric air pump, an electromagnetic air pump, a pneumatic element, a magnetic coupling thrust mechanism, a heating thrust generation mechanism, an electric heating thrust generation mechanism and a chemical reaction thrust generation mechanism.

10. The gas density relay of claim 1 or the gas density monitoring device of claim 2, wherein: the gas circuit stopping and pressure regulating mechanism is sealed in a cavity or a shell.

11. The gas density relay of claim 1 or the gas density monitoring device of claim 2, wherein: the gas circuit stopping pressure regulating mechanism further comprises a third cavity arranged between the first cavity and the second cavity, two ends of the third cavity are respectively communicated with the first cavity and the second cavity, and the longitudinal sections of the second cavity, the third cavity and the first cavity are of a stepped stepwise or continuous reducing structure; the other end of the connecting piece penetrates through the third cavity and the second cavity in sequence, extends out of the third interface and is connected with the driving part; the part of the connecting piece, which is positioned on the second cavity, is penetrated with a pressure change piece, the pressure change piece can movably pass in and out of the third cavity, and the pressure change piece is in sealing contact with the inner wall of the third cavity after entering the third cavity.

12. A gas density relay or gas density monitoring device according to claim 11, wherein: the pressure change member is a piston or a seal spacer.

13. The gas density relay of claim 1 or the gas density monitoring device of claim 2, wherein: the gas path cut-off pressure regulating mechanism further comprises a fourth cavity and a fifth cavity which are arranged between the first cavity and the second cavity, the first cavity, the fourth cavity, the fifth cavity and the second cavity are sequentially communicated, the section specification of the fourth cavity is larger than that of the first cavity, and the section specification of the fifth cavity is smaller than that of the first cavity; the other end of the connecting piece penetrates through the fourth cavity, the fifth cavity and the second cavity in sequence, extends out of the third interface and then is connected with the driving part; and a second pressure change piece penetrates through the part of the connecting piece, which is positioned in the second cavity, movably enters and exits the fifth cavity, and after entering the fifth cavity, the second pressure change piece is in sealing contact with the inner wall of the fifth cavity.

14. A gas density relay or gas density monitoring device according to claim 13, wherein: the second pressure changing member is a piston or a seal spacer.

15. The gas density relay of claim 1 or the gas density monitoring device of claim 2, wherein: the second interface of the gas path cut-off pressure regulating mechanism is communicated with the gas path of the electrical equipment through the multi-way joint.

16. The gas density relay of claim 1 or the gas density monitoring device of claim 2, wherein: the intelligent control unit acquires the gas density value acquired by the gas density detection sensor; or, the intelligence accuse unit acquires the pressure value and the temperature value that gas density detection sensor gathered accomplish gas density relay or gas density monitoring devices are to the on-line monitoring of the gas density of the electrical equipment who monitors.

17. The gas density relay of claim 1 or the gas density monitoring device of claim 2, wherein: the intelligent control unit acquires a gas density value acquired by the gas density detection sensor when the gas density relay body generates contact signal action or switching, and completes online verification of the gas density relay or the gas density monitoring device; alternatively, the first and second electrodes may be,

18. The gas density relay of claim 1 or the gas density monitoring device of claim 2, wherein: the intelligent control unit is controlled through field control and/or background control.

19. The gas density relay of claim 1 or the gas density monitoring device of claim 2, wherein: the gas density detection sensor is arranged on the gas density relay body; or the gas density detection sensor is arranged on the gas path cut-off pressure regulating mechanism.

20. The gas density relay of claim 1 or the gas density monitoring device of claim 2, wherein: the gas density detection sensor comprises at least one pressure sensor and at least one temperature sensor; or, the gas density detection sensor adopts a gas density transmitter consisting of a pressure sensor and a temperature sensor; or, the gas density detection sensor adopts a density detection sensor of quartz tuning fork technology.

21. The gas density relay of claim 1 or the gas density monitoring device of claim 2, wherein: the online check contact signal sampling unit is arranged on the gas density relay body; or the online check contact signal sampling unit is arranged on the gas circuit cut-off pressure regulating mechanism.

22. The gas density relay of claim 1 or the gas density monitoring device of claim 2, wherein: the online checking contact signal sampling unit comprises a first connecting circuit and a second connecting circuit, the first connecting circuit is connected with the contact of the gas density relay body and the contact signal control loop, and the second connecting circuit is connected with the contact of the gas density relay body and the intelligent control unit;

23. The gas density relay of claim 1 or the gas density monitoring device of claim 2, wherein: the gas circuit cut-off pressure regulating mechanism further comprises a moisture treating agent, and the moisture treating agent is arranged in the first cavity or/and the second cavity of the gas circuit cut-off pressure regulating mechanism; the moisture treatment agent comprises one of an adsorbent and a drying agent.

24. The gas density relay of claim 1 or the gas density monitoring device of claim 2, wherein: the gas circuit is by pressure regulating mechanism still includes filtering the piece, filter the piece setting on the second interface.

25. The gas density relay of claim 1 or the gas density monitoring device of claim 2, wherein: the online calibration of the gas density relay or the gas density monitoring device is completed by at least two gas density relay bodies, at least two gas circuit cut-off and pressure regulating mechanisms, at least two online calibration contact signal sampling units, an intelligent control unit and a gas density detection sensor; alternatively, the first and second electrodes may be,

26. A method of verifying a maintenance-free gas density relay as claimed in claim 1, comprising:

when the gas density relay works normally, the cut-off piece does not enter the first cavity, the first interface is communicated with the second interface, and the gas density relay monitors the gas density value in the electrical equipment;

the gas density relay is based on the set checking time or/and the checking instruction and the gas density value condition, under the condition of allowing to check the gas density relay:

27. A method of verifying a maintenance-free gas density relay as claimed in claim 26, comprising:

in a normal working state, the cut-off piece does not enter the first cavity, the first interface is communicated with the second interface, the gas density relay monitors the gas density value in the electrical equipment, and meanwhile, the gas density relay monitors the gas density value in the electrical equipment on line through the gas density detection sensor and the intelligent control unit;

28. The method for verifying the maintenance-free gas density relay as recited in claim 26, wherein the gas path cut-off pressure regulating mechanism further comprises a third cavity arranged between the first cavity and the second cavity, two ends of the third cavity are respectively communicated with the first cavity and the second cavity, and longitudinal sections of the second cavity, the third cavity and the first cavity are of a stepped stepwise-reducing structure or a continuous-reducing structure; the other end of the connecting piece penetrates through the third cavity and the second cavity in sequence, extends out of the third interface and is connected with the driving part; a pressure change piece is arranged in the part, located in the second cavity, of the connecting piece in a penetrating mode, the pressure change piece can movably enter and exit the third cavity, and the pressure change piece is in sealing contact with the inner wall of the third cavity after entering the third cavity; the verification method comprises the following steps:

29. A method of verifying a maintenance-free gas density relay as claimed in claim 28, comprising:

30. The method for verifying the maintenance-free gas density relay as recited in claim 26, wherein the gas circuit cut-off pressure regulating mechanism further comprises a fourth cavity and a fifth cavity which are arranged between the first cavity and the second cavity, the first cavity, the fourth cavity, the fifth cavity and the second cavity are sequentially communicated, the cross-sectional specification of the fourth cavity is larger than that of the first cavity, and the cross-sectional specification of the fifth cavity is smaller than that of the first cavity; the other end of the connecting piece penetrates through the fourth cavity, the fifth cavity and the second cavity in sequence, extends out of the third interface and then is connected with the driving part; a second pressure change piece penetrates through the part, located in the second cavity, of the connecting piece, the second pressure change piece can movably enter and exit the fifth cavity, and the second pressure change piece is in sealing contact with the inner wall of the fifth cavity after entering the fifth cavity; the verification method comprises the following steps:

31. A method of verifying a maintenance-free gas density relay as claimed in claim 30, comprising: