Dragging of boiler feed water pumps, two dragging General Motors and steam turbines, electric motors use AC motors, so the speed of the pump is speed, boiler water supply control by "throttling" regulation.
The basic mechanism is in the case of shortage of power supply, small and medium sized boiler capacity when there is surplus, and drag the new steam turbine-driven feed-water pump, exhaust steam into the district heating network, reduce main steam turbine extraction steam, while reducing power, increase in capacity.