NO BREAK FOR COMPRESSORS
[ Published in HOERBIGER@MOTION 02/2012 ]
MND Gas Storage is operating an underground gas storage facility in Uhřice, Czech Republic. For almost ten years now, gas has been compressed around the clock and delivered through wells located at depths of close to two kilometers (1.25 miles). Aclose partnership has existed with HOERBIGER through the Žandov branch ever since the storage facility was commissioned. Trust is essential in this partnership, as the HOERBIGER products play a central role in Uhřice: they ensure the safety and reliability of the compressors operated by MND Gas Storage.
MND Gas Storage stores natural gas for a variety of customers. They purchase storage capacity on the Energy Exchange and enter into long- or short-term contracts with MND Gas Storage. The gas is then stored in accordance with the customers' requirements, but does not belong to MND Gas Storage. The underground storage facilityin Uhřice is a former natural gas field. It has been used to store natural gas after gas production ceased there. The total capacity of the underground facility is 280 million cubic meters. The reservoir is located at adepth of approximately 1,800 meters (5,900 feet). The facility primarily stores natural gas from Russia, which is delivered via pipelines to Lanžhot in the Czech Republic, in the tripoint with Austria and Slovakia, from where it is transported underground to Uhřice. There, it is received in one of two enormous compressor halls.
The newer hall houses two 16-cylinder Caterpillar gas engines and the two-stage Ariel compressors driven by them. The compressors are used to compress the gas which is transported to Uhřice for underground storage. The gas is precompressed to a pressure of 12 MPa in a first stage. This is followed by a secondary compression up to a maximum pressure of 21 MPa, whereupon the gas is pumped underground through wells. The gas is compressed incrementally, because it heats up significantly under pressure. The two-stage compression allows the gas to be cooled in an intercooler. During regular operation, everything is largely automated. A HOERBIGER RecipCOM system monitors the compressors – an indispensable step for a facility that operates continuously. A key function of the monitoring system is to quickly detect sudden compressor damage and wear. A HOERBIGER HydroCOM system meanwhile controls the first compressor stage. The timing and flow of gas volume are exactly tailored to the demand. Because the gas volume that is compressed is always only the exact amount that is required, the dynamic HydroCOM control unit produces significant cost savings for MND Gas Storage compared to conventional control by way of the rotational speed of the compressor drive. The two compressors in the second hall are also equipped with a HydroCOM control unit and a RecipCOM monitoring system. All four compressors of MND Gas Storage handle an average of 5.4 million cubic meters of gas a day at full utilization of the facility.
From the central monitoring and operations room of the facility, an operator has control over the network of wells and their safety valves. The readings and data of the HydroCOM control units and of the HOERBIGER RecipCOM systems which are installed on the compressors are also merged here.
MND Gas Storage has relied on HOERBIGER technology since 2006. The technology forms an integral part of the facility and ensures that it operates efficiently and safely: lower complexity equates to higher reliability. HOERBIGER is also a service partner when it comes to maintaining the systems and compressors. Maintenance is performed at service intervals of one to two years – depending on the number of hours the machines have been running. In addition, the service team of HOERBIGER Žandov s.r.o. can be on-site at any time as needed. HOERBIGER came out ahead in an invitation to bid. The objective was to regulate the machine performance without lowering the rotational speed. Out of the various systems that are offered in the market, the HOERBIGER HydroCOM control unit and the HOERBIGER RecipCOM monitoring system were those that met the needs the best. The employees of MND Gas Storage in Uhřice value HOERBIGER as an extremely reliable and flexible partner who tries to accommodate all their requests. A major advantage is HOERBIGER'sbranch in the Czech Republic, HOERBIGER Žandov s.r.o. Sharing the language and having knowledge of the local regulations make it much easier to work together.