Computerized Management System of Netural Gas Transmission

In the field of external sales of gas stations, the traditional method of measurement standards through cutting expenditure orifice devices and dual-differential pressure of bellows to measure. Measurement accuracy poor, low degree of automation, the volume of natural gas a greater impact on human factors, the statements as easily distorted and not in the decision-makers rapid and accurate understanding of production.

In order to resolve these conflicts, development of natural gas measurement computer management system, in the full realization of computer stations measurement management. SY/T6143-1996 measurement system used in the selection of hardware and software platform selection is made on long-term considerations, with advanced technology and system scalability strong, stable performance advantages. Not only can improve the measurement of the degree of automation of natural gas, and change the past, the shortcomings of low measurement accuracy, broad prospects and promotion of value.

A system composed of

System of block diagram as shown in Figure 1.

Figure 1 online calibration system and structure of the lecturers

1.1 hardware Selection

In order to ensure the system long-term and stable operation, to be chosen host of a stable industrial control machines. At the same time, the development of networks and the actual needs, various units of the decision-makers need to understand first-hand information, the scene is set in a modem, receive and respond to the request, so that the signal to the collection and statistical information to Can timely feedback to policy makers.

Main hardware from HUB, orifice, the flow computer, multivariable transmitter, pressure transmitter, heat resistance, IPC, UPS power supply, modems, and other components.

1.2 Software Selection

In order to make the system available to users of a beautiful, easy to operate the most comprehensive, multi-window I choose the Windows operating system, the use of the confiscated wealth of system resources, making the system more vitality and scalability. The system chosen by the United States WonderWare developed by Intouch IPC configuration software, the software driver is rich in resources, operating in the Windows system, tailored to different hardware resources, using descriptive language, easy to understand and modify , The most comprehensive and operating system development by building blocks of piled up short development cycle. At the same time the software and support NetBIOS TCP / IP protocol, conducive to the realization of long-distance communications.

1.3 software

Window98 use of network services, to the scene as a dial-up computer network servers, the use of Intouch NetDDE functions through TCP / IP protocol, the requesting party via modem to communicate with the host site, thereby achieve the objective of long-distance communications, and can be carried out Remote debugging.

acquisition card and the realization of communication

Metering system through DDE (Dynamic Data Exchange) ROC407 driver and the exchange of data and communications available by the VB VC or written agreement to sign the procedures to DDE.

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Measurement standards by the People's Republic of oil and gas industry standards SY / T 6143-1996 "gas flow measurement standards Orifice" method used to prepare descriptive language, and some of the necessary procedures and data downloaded to the ROC407.

Software interface generation

Software interface used building blocks (configuration)-generating method to generate a lively, simple and easy to operate interface.

1.4 Principle

Metering system chosen instrument of the U.S. company's Fisher-Rosemount ROC407 management and multivariable transmitter for external gas measurement. Signal gas pressure, temperature and the thermal resistance signal the formation of gas through orifice multi-variable differential signal from the transmitter sent to the ROC407 management, traffic management by the plot calculated for instantaneous flow, and the cumulative flow of traffic this month, last month Flow of traffic results by the controller to spread to computer data, computer-flow statements and the preservation of records of historical data. Acquisition of computer signal through telephone lines spread to scheduling or other computer companies, and through corporate local area network for data sharing.

1.5 system

real-time collection, shows that the instantaneous flow of natural gas, temperature, pressure, differential pressure parameters and calculated. Save the day flows, yesterday's traffic, traffic this month, last month, traffic and other results, and to view, print, temperature, pressure, differential pressure of real-time trends and historical trends;

System fully functional, measurement accuracy than double the original bellows 0.5 percent, system scalability strong and technologically advanced;

can be pressure, temperature-compensation;

dynamic screen display, window operation, the set of parameters for convenience, production and printing of various statements;

implementation of user rights management, different users have different operating authority, the system safe and reliable;

alarm system with real-time capabilities, and a hardware self-test function;

With a standard communication interface, and support for NetBIOS TCP / IP network protocol, and so on, through long-distance telephone communications network to the scene to view real-time data.

1.6 System features

description of the building blocks of software programming;

incident software programming;

DDE dynamic data exchange;

remote data access.

2 Conclusion

In the natural gas transmission and distribution, gas stations by computer measurement system,Not only improve the accuracy of the measurement, greatly reduced the labor intensity of the workers, and reliable operation of the system allows the company's credibility has been enhanced. Real-time lecturer at the parameters so that operators can collect timely detection measures failures, to avoid unnecessary losses, while also based on real-time instantaneous gas to gas scheduling, scheduling can make gas more quickly and accurately to meet the needs of users.

System provides the historical record in the transfer of lecturers when the two sides have a common basis for discussion, also based on historical records to check whether the operators of sewage and other operations carried out on time, operators can increase the sense of responsibility.

With the assumption that a gas station, the volume of gas in more than 800 million m 3, by improving the accuracy of 0.5%, the measurement error could reduce the annual 4 million N m 3. From this we can see, it has very substantial economic and social benefits.

By the draft date: 2002-01-21.

The first author Zhang Xin, female, born 1975, 1996 graduated from the Xi'an University of Electronic Science and Technology; have been engaged in the design of instrumentation and control work.