Helping Russia survive its winters

Open and flexible control for the Uwjasowskoje natural gas storage tank outside Moscow is provided GE Fanuc PLCs and visualisation software

to heat their apartments in the winter, the citizens of Moscow mainly use district heating, provided by the local thermal power plants which use gas produced in Siberia. As the energy consumption is very high in the cold season, important gas reserves have to be built up during the rest of the year.

For this temporary storage, a number of natural gas storage tanks are used, all located within 350km of Moscow. Some of these natural gas storage tanks are run by Monstransgaz, a Gazprom subsidiary.

The gas reserves are pipelined from Siberia to the storage tanks. In order to store the hundreds of millions of cubic metres, the gas is first compressed and then injected into the huge gas storage containers by way of injection probes. The Uwjasowskoje storage tank uses six gas compression stations and 95 gas injection probes.

Injection of the gas needs to be carried out very slowing and according to the prevailing conditions. In the summer, the 95 probes are used to inject the gas at a pressure of 115bar. In the winter the same probes are used to retrieve the gas from the tank.

Control concept

The control concept for the area containing the injection probes was developed, implemented and commissioned by system integrator Elpro - a company specialising in applications in the gas, petrochemical and energy industries and in environmental technology.

The control concept was based around products supplied by GE Fanuc, which provided the openness and flexibility to meet the rigorous application requirements. The injection probe control system had to communicate with third-party controllers installed at the compression station. Communication with the flowmeter calibration also had to be ensured.

Five GE Fanuc Series 90-70 PLCs with over 2800 analogue and digital I/O points are used to monitor and control the injection probe area. The I/O count includes valves and fittings, as well as collection and control of various parameters such as flow rate, temperature and pressure. An Ethernet TCP/IP network is used for data transmission between the controllers and CIMPLICITY Plant Edition - the software used for monitoring and control. The system handles 8,000 data points and offers server redundancy. In the event of a failure of the main server, the system automatically switches to the backup server without interruption of the control system. Folkhard Just, head of the engineering department at Elpro, comments: "Implementing CIMPLICITY was very easy and quick. The visualisation software is also used to visualise the compression station functions. Using CIMPLICITY, integration with the third-party controllers presented no problem."

The success of the control concept at Uwjasowskoje can be gauged by the fact that it has already been defined as a standard by Monstransgaz for future plants. Indeed, the modernisation of the gas storage plant in Kasimov - three times bigger than the present one - is already under way, using Elpro know-how and GE Fanuc products.

GE Fanuc
h104@industrialnetworking.co.uk