Visualization and archiving of data from gas-volume conversion devices and chromatographs at the Brandov Border Transfer Station

For more than 40 years, the NET4GAS company has been a natural gas provider for both international and domestic markets. Today, this company operates more than 3,600 km of gas pipelines and owns an exclusive license for the transmission of gas in Czechia.

During the 2009 gas crisis, gas supplies to Czechia were cut off due to the Russia–Ukraine gas disputes. It was then decided to build a new natural gas pipeline named Gazela. This step ensures Czechia is no more dependent on natural gas imports transported through Ukraine. Thanks to Gazela and OPAL, a natural gas pipeline in Germany, which are interconnected on the German-Czech border near the village of Brandov, the Nord Stream pipeline supplies Czechia with natural gas from northern parts of Russia.

System requirements

GEOVAP's AVE 2 system, which is operated by NET4GAS, is used at the Brandov Border Transfer Station to automatically obtain business data from gas-volume conversion devices and chromatographs. The AVE 2 system uses this data to generate transfer protocols and, every day, passes the data to follow-up systems for further processing.

Because some devices at Brandov are limited in use (e.g., EnCall 3000 chromatographs by Elster that do not allow reading data directly from the data archive, but only provide values measured for the previous hour), it was necessary to build a local reading system for obtaining non-archived and unused data from these devices and from other data terminals. This data will be archived and visualized. In the event of a remote communication failure, it will be used as
a UPS for the AVE 2 system.

After a negotiation with NET4GAS, the following requirements for the reading system were specified:

Creating two independent data concentrators for data capture from the sections Export and Import
Archiving of all data for at least a year
Data conversion based on given equations
Converting data into hourly and daily averages
Archiving values (EnCall 3000 calorific and chemistry values, gas flow values from Elster M2000 flow computers, water and hydrocarbon dew point values, content of oxygen in gas, sulfur chromatogram data)
Possibility to locally visualize obtained data as tables and trends
Passing all obtained data to the AVE 2 system

Based on the above stated requirements, examination with NET4GAS representatives at Brandov, and mainly based on experiences with remote business data transfer from the Brandov station to the AVE 2 system, the following solution has been proposed:

Create two local data concentrators for automated data capture from different data sources. This data will be converted and archived at hourly/daily intervals.

Control system

To meet the requirements, it was suggested to use an industrial Tecomat Foxtrot PLC with
a user-defined program for operating the peripherals, data conversion, and archiving according to customer specification, and industrial touch panel PCs.

Data is stored on a removable card with sufficient capacity to archive data for more than a year. Concurrently, data for the last 14 days is stored in the PLC's retain memory so that no data loss occurs when removing the SD card. To provide clock synchronization, the PLC automatically synchronizes the system time with the NET4GAS time server via SNTP (this feature is unconditionally necessary for providing data archiving with proper time stamps as the chromatographs only provide data without time stamps.

Data from the PLC is read locally and stored on an integrated industrial touch panel PC. On this PC, the Reliance 4 SCADA/HMI system is installed to be used for logging data to a local database, displaying data as tables and trends, and visualizing individual sections. The data can also be accessed from any remote locations within the NET4GAS measuring network using Reliance 4 Web Client.

Both the PLC and the industrial touch panel PCs are located in a separate control cabinet that is powered from the Brandov station's secure circuit. A separate UPS and overvoltage protection elements are also part of the control cabinet.

Strong emphasis is placed on security, reliability, and redundancy, so no data loss can occur. For this purpose, the system was designed by using industrial-use-only devices and drawn up to make its parts as much independent of one another and non-interchangeable as possible.