CN108662245B

CN108662245B - Anti-jamming and anti-freezing control device and control method for electric regulating valve

Info

Publication number: CN108662245B
Application number: CN201710209256.7A
Authority: CN
Inventors: 成涛
Original assignee: Shanghai Meishan Iron and Steel Co Ltd
Current assignee: Shanghai Meishan Iron and Steel Co Ltd
Priority date: 2017-03-31
Filing date: 2017-03-31
Publication date: 2020-06-16
Anticipated expiration: 2037-03-31
Also published as: CN108662245A

Abstract

The invention relates to an anti-jamming and anti-freezing control device for an electric regulating valve, which comprises an actuating mechanism, an actuating mechanism connecting rod, a valve core action connecting piece, a communicating module, a valve connecting rod, an electric isolating door, a valve, an electric isolating door, a proximity switch and an actuating mechanism wiring terminal box, wherein the actuating mechanism and the valve at the bottom end form the electric regulating valve, the actuating mechanism is connected with the valve through the actuating mechanism connecting rod and then is rigidly connected with the communicating module, an upper proximity switch and a lower proximity switch are additionally arranged on one side of the valve core action connecting piece of the regulating valve, and an actuating mechanism wiring terminal 13 is arranged on one side above the actuating mechanism. The small stepping inching control of the regulating valve is realized by adopting the switching value signal output by the timing controller, so that the action reliability of the regulating valve or the standby regulating valve in extreme weather is ensured, and the stable operation of production is ensured.

Description

Anti-jamming and anti-freezing control device and control method for electric regulating valve

Technical Field

The invention relates to a control device, in particular to an anti-jamming and anti-freezing control device for an electric regulating valve, and belongs to the technical field of electric instrument control.

Background

The electric regulating valve is medium circulation and control and important equipment in the production process of industrial and mining enterprises, for example, a boiler water supply and temperature reduction water regulating valve is generally provided with two ways of regulation, one main loop regulation and one auxiliary loop regulation, and an operation operator generally adjusts and switches the main loop and the auxiliary loop at intervals, when one way of the regulating valve is operated, the other way of the regulating valve is standby, particularly in extreme weather below zero in winter, because a valve core has a small amount of medium leakage, particularly medium with water and steam, and the standby regulating valve does not act for a long time, the fault phenomenon that a valve rod and the valve core of the regulating valve are suddenly frozen and jammed once the regulating valve needs to be immediately put into normal operation is easy to occur, at the moment, DCS main control fails, and once the process needs to be switched to be put into operation, the valve cannot be controlled due to the. The water reducing device for the boiler 1 or 2 for dry quenching of the thermal power plant has the advantages that the water supply regulating valve has the phenomenon of large-range freezing and jamming of the regulating valve in extreme weather below zero, and the safe operation of the boiler is seriously endangered. Those skilled in the art have attempted to solve this problem, but the problem has not been solved well.

Disclosure of Invention

The invention provides an anti-jamming and anti-freezing control device for an electric regulating valve, aiming at the technical problems in the prior art, the technical scheme has a compact structure, small-step inching control over a regulating valve is realized by adopting a switching value signal output by a timing controller, and the action condition of a valve core of the regulating valve on site is detected by using a proximity switch as feedback to form a set of complete closed-loop test, alarm and valve core electric heating control loop, so that the action reliability of the regulating valve or a standby regulating valve in extreme weather is ensured, and the stable production operation is ensured.

In order to achieve the purpose, the technical scheme of the invention is that the anti-jamming and anti-freezing control device for the electric regulating valve is characterized by comprising an actuating mechanism, an actuating mechanism connecting rod, a valve core action connecting piece, a communicating module, a valve connecting rod, a first electric isolating door, a valve, a second electric isolating door, a first proximity switch, a second proximity switch and an actuating mechanism wiring terminal box, wherein the actuating mechanism and the valve at the bottom end form the electric regulating valve; the proximity switch is installed through the metal wire hole to strengthen fixation and cannot shake; the actuating mechanism wiring terminal is arranged on one side above the actuating mechanism.

As an improvement of the invention, the device also comprises an electric heating cover and a power supply terminal box, wherein the electric heating cover is additionally arranged around the valve core connecting piece of the regulating valve, and the power supply terminal box of the electric heating cover is arranged at the bottom end.

As an improvement of the invention, the front end and the rear end of the electric control valve are respectively provided with a first electric isolation door and a second electric isolation door.

The control method of the anti-jamming and anti-freezing control device of the electric regulating valve comprises the following steps: 1) when the on-line test loop is put into operation, the DCS control system firstly outputs an opening command to the executing mechanism, the executing mechanism is opened by 5%, the opening signal proximity switch detects the action condition of the valve opening, the proximity switch outputs a valve opening signal to the DCS through signal conversion, and after the loop closing is finished, the valve opening action detection is normal; 2) at the interval of 60 seconds, the DCS outputs a closing command to the executing mechanism, the executing mechanism is closed by 5 percent, the closing signal proximity switch detects the action condition of closing the valve, the proximity switch outputs a valve closing signal to the DCS through the signal conversion mechanism, and after the closed loop is completed, the valve closing action detection is normal; 3) through repeated cycling of the closing and opening action tests at intervals of 60 seconds, the valve activity of the electric regulating valve is ensured, the normal and reliable action after the electric regulating valve is put into operation is ensured, and particularly in extreme weather below zero, the continuous opening and closing action ensures that the valve core of the regulating valve cannot be frozen and jammed; 4) the switching value output signal of the inching test loop of the DCS control system is sent to the executing mechanism, once the executing mechanism refuses to move, the approach switch cannot detect the valve action condition, the DCS judges that the valve fails at the moment, immediately sends out acousto-optic alarm to prompt an maintainer to immediately rush to the site to check the valve jam condition, if the valve fails to work in extreme subzero weather, the electric heating cover is immediately and automatically put into use, and the fault that the valve adjusting valve core is jammed due to freezing is eliminated through sufficient heating.

Compared with the prior art, the invention has the advantages that 1) the technical scheme has ingenious and compact integral structure design and lower cost; 2) the technical scheme designs a closed loop test circuit for the action reliability of the actuating mechanism, and ensures that the regulating valve is not frozen and jammed; 3) the technical scheme adopts a non-contact proximity switch to detect the action condition of a valve core connecting rod of an actuating mechanism, so as to ensure the reliability of a test loop, 4) the technical scheme can detect the displacement of the action condition of the valve core of the regulating valve through the proximity switch, and once the valve core is refused to move, the fault of the regulating valve can be early warned in advance, so as to gain time for timely maintenance; 5) according to the technical scheme, the valve core of the regulating valve is easily frozen and is continuously heated initially by the electric heating cover, so that the action of the valve is ensured; 6) this technical scheme has designed a set of complete closed loop test and warning heating control circuit that unfreezes and has guaranteed the action reliability of governing valve or reserve governing valve in extreme weather, ensures production steady operation.

Drawings

FIG. 1 is a schematic view of the overall structure of the present invention;

FIG. 2 is a block diagram of a control loop;

in the figure: 1. the actuating mechanism, 2, actuating mechanism connecting rod, 3, case action connecting piece, 4, UNICOM module, 5, valve connecting rod, 6, first electronic isolation door, 7, valve, 8, electric heating cover, 9, power terminal box, 10, the electronic isolation door of second, 11, first proximity switch, 12, second proximity switch, 13, actuating mechanism wiring terminal box.

The specific implementation mode is as follows:

for the purpose of enhancing an understanding of the present invention, the present embodiment will be described in detail below with reference to the accompanying drawings.

Example 1: referring to fig. 1, an anti-jamming and anti-freezing control device for an electric control valve comprises an execution mechanism 1, an execution mechanism connecting rod 2, a valve core action connecting piece 3, a communicating module 4, a valve connecting rod 5, a first electric isolation door 6, a valve 7, a second electric isolation door 10, a first proximity switch 11, a second proximity switch 12 and an execution mechanism wiring terminal box 13, wherein the execution mechanism 1 and the valve 7 at the bottom end form the electric control valve, the execution mechanism 1 is connected with the valve 7 through the execution mechanism connecting rod 2 and the valve connecting rod 5, and the communicating module 4 is used for rigid connection, so that the electric execution mechanism can drive the action of a valve core below the electric control valve, and an upper proximity switch 12 and a lower proximity switch 11 are additionally arranged on one side of the valve core action connecting piece 3 of the electric control valve; the proximity switch is installed through the metal wire hole to strengthen fixation and cannot shake; the actuator terminal 13 is mounted on the upper side of the actuator.

Example 2: referring to fig. 1, as a modification of the present invention, the apparatus further includes an electric heating cover 8 and a power terminal box 9, the electric heating cover 8 is additionally installed around the connection member of the valve core of the regulator valve, and the power terminal box 9 of the electric heating cover is installed at the bottom end. According to the technical scheme, the valve core of the regulating valve is easily frozen and is continuously heated initially by the electric heating cover, so that the action of the valve is ensured;

example 3: referring to fig. 1, as an improvement of the present invention, a first electric isolation door and a second electric isolation door are respectively disposed at the front end and the rear end of the electric control valve.

The working principle is as follows: referring to fig. 1 and 2, during the normal operation of the electric control valve, a DCS outputs an analog quantity signal to directly control the opening and closing of the valve to meet the requirements of process production, when the valve is required to perform an operation reliability test, the DCS is switched to the on-off quantity inching control, the opening step is set to be 5%, the opening limit is controlled to operate between two proximity switches, the medium flow allowed by the opening is set on the basis that the production is not affected, a timer sets the on-off quantity output interval time to be 60 seconds, namely, the on-off command and the on-off command are separated by 60 seconds, and the inching command is output repeatedly and circularly, so that the closed-loop control of the on-line operation reliability. The control method of the anti-jamming and anti-freezing control device of the electric regulating valve comprises the following steps: 1) when the on-line test loop is put into operation, the DCS control system firstly outputs an opening command to the executing mechanism, the executing mechanism is opened by 5%, the opening signal proximity switch detects the action condition of the valve opening, the proximity switch outputs a valve opening signal to the DCS through signal conversion, and after the loop closing is finished, the valve opening action detection is normal; 2) at the interval of 60 seconds, the DCS outputs a closing command to the executing mechanism, the executing mechanism is closed by 5 percent, the closing signal proximity switch detects the action condition of closing the valve, the proximity switch outputs a valve closing signal to the DCS through the signal conversion mechanism, and after the closed loop is completed, the valve closing action detection is normal; 3) through repeated cycling of the closing and opening action tests at intervals of 60 seconds, the valve activity of the electric regulating valve is ensured, the normal and reliable action after the electric regulating valve is put into operation is ensured, and particularly in extreme weather below zero, the continuous opening and closing action ensures that the valve core of the regulating valve cannot be frozen and jammed; 4) the switching value output signal of the inching test loop of the DCS control system is sent to the executing mechanism, once the executing mechanism refuses to move, the approach switch cannot detect the valve action condition, the DCS judges that the valve fails at the moment, immediately sends out acousto-optic alarm to prompt an maintainer to immediately rush to the site to check the valve jam condition, if the valve fails to work in extreme subzero weather, the electric heating cover is immediately and automatically put into use, and the fault that the valve adjusting valve core is jammed due to freezing is eliminated through sufficient heating.

As shown in the test and exception control loop block diagram of fig. 2; the DCS control system is provided with three control modes of normal, test and abnormal. When the electric regulating valve is normally controlled, the DCS outputs an analog quantity signal to a wiring terminal of the actuating mechanism to directly control the action of the regulating valve; when the test loop is put into use, the DCS sends out a switching value signal to directly control the electric regulating valve to perform inching operation through the timing output function of the timing controller; at the moment, the proximity switch starts to work in detection, when a inching signal of test control is sent out, the action of the valve core of the regulating valve is responded by the detection of the proximity switch in time, namely the closing loop is successful; if the proximity switch cannot detect the inching displacement signal of the regulating valve, the DCS control system judges that the electric regulating valve has a fault logically, and immediately gives out an audible and visual alarm to remind maintainers to rush to the field for processing the problem, and if the DCS is used for the electric heating cover immediately in the extreme weather below zero.

The technical scheme provides a closed-loop actuating mechanism action reliability test loop, and ensures that the regulating valve is not frozen and jammed; a non-contact proximity switch is adopted to detect the action condition of a valve core connecting rod of the actuating mechanism, so that the reliability of a test loop is ensured; the displacement detection of the action condition of the valve core of the regulating valve through the proximity switch can early warn the fault of the regulating valve in advance once the valve core of the regulating valve is refused to move, so that time is saved for timely maintenance; an electric heating cover is adopted to easily and continuously heat the valve core of the regulating valve at the beginning of freezing, so that the action of the valve is ensured; a set of complete closed-loop test and alarm heating unfreezing control circuit guarantees the action reliability of the regulating valve or the standby regulating valve in extreme weather, and ensures stable production operation.

The invention can also combine at least one of the technical characteristics described in the embodiments 2 and 3 with the embodiment 1 to form a new embodiment.

It should be noted that the above-mentioned embodiments are not intended to limit the scope of the present invention, and all equivalent modifications and substitutions based on the above-mentioned technical solutions are within the scope of the present invention as defined in the claims.

Claims

1. The control method of the anti-jamming and anti-freezing control device of the electric regulating valve comprises an actuating mechanism (1), an actuating mechanism connecting rod (2), a valve core action connecting piece, a communicating module, a valve connecting rod, a first electric isolation door (6), a valve (7), a second electric isolation door (10), proximity switches and an actuating mechanism wiring terminal box, wherein the actuating mechanism and the valve at the bottom end form the electric regulating valve, the actuating mechanism (1) is connected with the valve (7) through the actuating mechanism connecting rod (2) and the valve connecting rod (5) and then rigidly connected by the communicating module (4), the upper proximity switch and the lower proximity switch are additionally arranged on one side of the valve core action connecting piece of the regulating valve, and the actuating mechanism wiring terminal box is arranged on one side above the actuating mechanism; the device also comprises an electric heating cover and a power supply terminal box, wherein the electric heating cover is additionally arranged around the valve core connecting piece of the regulating valve, and the power supply terminal box of the electric heating cover is arranged at the bottom end; a first electric isolation door (6) and a second electric isolation door (10) are respectively arranged at the front end and the rear end of the electric control valve;

the method is characterized by comprising the following steps: 1) when the on-line test loop is put into operation, the DCS control system firstly outputs an opening command to the executing mechanism, the executing mechanism is opened by 5%, the opening signal proximity switch detects the action condition of the valve opening, the proximity switch outputs a valve opening signal to the DCS through signal conversion, and after the loop closing is finished, the valve opening action detection is normal; 2) at the interval of 60 seconds, the DCS outputs a closing command to the executing mechanism, the executing mechanism is closed by 5 percent, the closing signal proximity switch detects the action condition of closing the valve, the proximity switch outputs a valve closing signal to the DCS through the signal conversion mechanism, and after the closed loop is completed, the valve closing action detection is normal; 3) through repeated cycling of the closing and opening action tests at intervals of 60 seconds, the valve activity of the electric regulating valve is ensured, the normal and reliable action after the electric regulating valve is put into operation is ensured, and the valve core of the regulating valve is ensured not to be frozen and jammed through continuous opening and closing actions in extreme weather below zero; 4) the switching value output signal of the inching test loop of the DCS control system is sent to the executing mechanism, once the executing mechanism refuses to move, the approach switch cannot detect the valve action condition, the DCS judges that the valve fails at the moment, immediately sends out acousto-optic alarm to prompt a maintainer to immediately rush to the site to check the valve jam condition, if the valve fails to work in extreme subzero weather, the electric heating cover is immediately and automatically put into use, and the fault that the valve core of the regulating valve is jammed due to freezing is eliminated through sufficient heating.