CN101430549A

CN101430549A - On-site signal collection and application

Info

Publication number: CN101430549A
Application number: CNA2007101500940A
Authority: CN
Inventors: 侯秀云; 张洁
Original assignee: Tianjin Botian Chemical Co Ltd
Current assignee: Tianjin Botian Chemical Co Ltd
Priority date: 2007-11-07
Filing date: 2007-11-07
Publication date: 2009-05-13

Abstract

The acquisition and application on field signals relates to a temperature in-out monitoring and controlling system. Thermoelectric couple thermo emf signals which measure the temperature of a converter are locally transmitted to a remote I/O station arranged in a control box on the spot by a bit of compensating cable, treated and converted into digital quantity signals, and then run through the spot by a communication Profibus-DP bus, and finally the signals are led to a control room. The signals are transmitted to the Profibus-DP bus communication module of a master control station by a coupler and RS-485 bus transmission, and enter into an operating station for monitoring by a data transmission bus. The invention saves the usage amount of hardware and reduces maintenance and cost.

Description

The collection of on-site signal and application

Affiliated technical field

The present invention relates to a kind of automatic temperature control, refer more particularly to a kind of temperature input and output monitor control system.

Background technology

In the Chemical Manufacture, VCM is synthetic to be transformed is important procedure during VCM produces, and acetylene and hydrogen chloride dewater through mixed freezing, again through being that carrier, mercuric chloride are that the tubulation converter of catalyst reacts and generates the VCM monomer with the activated charcoal.The temperature of forward and backward converter is important controlled variable in the course of reaction, establishes 6 temperature detection in every converter at least, and like this, whole device has so hundreds of points of temperature detecting point.The mode of traditional detection converter temperature is: the thermoelectrical potential signal of thermopair that is used to survey the converter temperature enters active station through data transmission bus and monitors through the fastener and the control station of thermopair compensating cable directly into the DCS system.The technological deficiency of this mode is: its needs a large amount of cables, crane span structure, need to increase hardware such as corresponding calculated machine fastener, install in addition and the maintenance cost height.

Summary of the invention

The objective of the invention is: field bus technique is applied in the measuring system of converter, overcomes the weakness of traditional detection mode, improve detection speed, save a large amount of engineering costs.

In order to achieve the above object, the technical solution used in the present invention is:

A kind of collection of on-site signal and application, comprise thermopair, bus type remote I/O station, intrinsic safety section coupling mechanism, control station, active station, wherein active station is connected with control station, and control station connects intrinsic safety section coupling mechanism, and intrinsic safety section coupling mechanism is connected by the bus type remote I/O station with thermopair.

The collection of the above on-site signal and application, the thermopair 5 thermoelectrical potential signals that wherein are used for surveying the converter temperature are delivered to the remote I/O station 7 that places on-the-spot control box nearby through a bit of compensating cable 6, the treated digital quantity signal that converts to, run through on-the-spot by a communication Profibus-DP bus 8 again, signal is caused the pulpit, through intrinsic safety section coupling mechanism 9, through 10 transmission of RS-485 bus, send in the module 11 of Profibus-DP bus communication of control station 12, through data transmission bus 13, enter active station 14 and monitor.

Fieldbus is as the basis of factory's digital communication network, linked up between production run scene and the opertaing device and and higher control and management layer between get in touch.It is not only a basic network, but also is a kind of open, novel full distribution control system.In other words, fieldbus is exactly to be dispersed in on-the-spot measuring equipment and to become a node in the network single, is tie with the fieldbus, intercourses information, therefore we can say that field bus technique is an ingredient of control system of new generation.Profibus-DP is a kind of representative fieldbus, be aim at that automatic control system and device level disperse communication design between the I/O a kind of at a high speed, fieldbus cheaply.It meets international standard EN50170, is a kind of fieldbus of opening.

Description of drawings

Fig. 1 is a system control mode block diagram of the present invention.

Among the figure: 1. converter before, 2. back converter, 3. demercuration device, 4. converter refrigeratory, 5. thermopair, 6. thermopair compensating cable, 7. bus type remote I/O station, 8.Profibus-DP bus, 9. intrinsic safety section coupling mechanism, 10.RS-485 bus, 11. the module of bus communication, 12. control station, 13. data transmission bus, 14. active stations.

Embodiment

Be example now, introduce the concrete application of on-site bus type remote I/O system in Chemical Manufacture to produce 100,000 tons of/year vinyl chloride projects.Need explanation a bit, this project is except that the converter temperature, and the Detection ﹠ Controling of other parameter are all finished by the CS1000 system of Japanese Yokogawa, and promptly the CS1000 system is the main website of The whole control system, and bus type remote I/O system is as slave station.

By accompanying drawing as can be known, the present invention includes thermopair 5, bus type remote I/O station 7, intrinsic safety section coupling mechanism 9, control station 12, active station 14, wherein active station 14 is connected with control station 12, control station 12 connects intrinsic safety section coupling mechanism 9, and intrinsic safety section coupling mechanism 9 is connected by bus type remote I/O station 7 with thermopair 5.Wherein, hot thermocouple 5 electric potential signals that are used for surveying the converter temperature are delivered to the remote I/O station 7 that places on-the-spot control box nearby through a bit of compensating cable 6, treated convert digital quantity signal to after, run through on-the-spot by a communication Profibus-DP bus 8 again, signal is caused the pulpit, through intrinsic safety section coupling mechanism 9, through 10 transmission of RS-485 bus, send in the module 11 of Profibus-DP bus communication of control station 12, enter active station through data transmission bus 13 again and monitor.

Compare with traditional control method: one, adopt traditional control method, the transmission signals between scene and the pulpit belongs to analog quantity; And adopt the remote I/O system control mode of field bus technique, the hot thermocouple electric potential signal at the scene in the remote I/O station treatment conversion become digital quantity signal, send the pulpit again.Because of adopting the digital quantity communication, transmission speed improves greatly, makes measurement more promptly and accurately, thereby helps the monitoring to the converter temperature.Two, adopt the MV measured value of traditional control method thermopair directly to send the DCS fastener to measure, consider, need 20 of fasteners approximately, and increase the control corresponding station by 16 shared fasteners; And adopt above-mentioned bus type intrinsic safety remote I/O system, and on-the-spotly only need to increase by 6 field control case 7 and annexes thereof that are used to install the remote I/O device, and 11 of the modules of bus communication accounting for a draw-in groove of control station, the economize on hardware expense is apparent.Three, behind the introducing field bus technique, a large amount of thermopair compensating cable 6 and crane span structure can be saved in the scene.Four, adopt the remote I/O system control mode of field bus technique, corresponding artificial mounting cost etc. also reduce greatly, and maintenance also reduces in the future.

Claims

1, a kind of collection of on-site signal and application, comprise thermopair (5), bus type remote I/O station (7), intrinsic safety section coupling mechanism (9), control station (12), active station (14), it is characterized in that: described active station (14) is connected with control station (12), control station (12) connects intrinsic safety section coupling mechanism (9), and intrinsic safety section coupling mechanism (9) is connected by bus type remote I/O station (7) with thermopair (5).

2, collection and application according to the described on-site signal of claim 1, it is characterized in that: thermopair (5) the thermoelectrical potential signal that wherein is used for surveying the converter temperature is delivered to the remote I/O station (7) that places on-the-spot control box nearby through a bit of compensating cable (6), the treated digital quantity signal that converts to, run through on-the-spot by a communication Profibus-DP bus (8) again, signal is caused the pulpit, through intrinsic safety section coupling mechanism (9), transmit through RS-485 bus (10), send in the module (11) of Profibus-DP bus communication of control station 12, through data transmission bus (13), enter active station (14) and monitor.