Pressure maintaining system for district heating network - adapting pump output to varying requirements of network

摘要

Pressure-maintainings system for municipal heating network comprises an overflow valve (4), and a pressure-controlling pump (1) of which the speed is controlled according to the water stream supplied via the overflow valve, pref. so that the water stream takes on a low value just sufficient for discharge of a control pulse. The pulse may be obtained from the position of the valve spindle which is provided with a pulse generator (7). Alternatively, the pulse may be obtained from a throttle point downstream of the overflow valve in the overflow pipe (3) and creating a pressure which controls the speed of the pump. The system may also be used for district cooling networks in which the change in vol. by increase or decrease in temp. plays a much smaller role.