The Design of a Control System for Pipeline Compression Applications

The Russian natural-gas distribution system includes 125,000 miles of pipe and some 250 major pumping stations equipped with 3,700 turbine-driven compressor units. A majority of these stations were built in the 1970s and 1980s: consequently, their operational efficiency is lower than modern stations equipped with high-efficiency compressor units. In order to improve the efficiency of these compressor stations, over half of the compressor units are being retrofitted with integrated, turbine-and-compressor control systems allowing them to operate closer to pipe pressure, turbine temperature-pressure limits, and compressor surge. It is projected, and results so far confirm, that these new control systems will not only increase compressor-station efficiency and significantly reducing the amount of gas diverted to fuel the downstream pumping stations, but will increase the amount of gas that can be transported. Additionally, several of the new or refined control algorithms, developed to meet customer expectations and acceptance tests, should be applicable in other areas and applications.