Detailed Information - District Heating
Detailed information - District Heating
District heating condenser
When supplying water to a district heating system, the heat input is often transferred from the Steam turbine exhaust to a so called district heating condenser. The condensate from this condenser is fed to the deaerator. There are also systems in which the required heat is partially drawn from the flue gases of the waste heat boiler.
During summer time the temperature of the water in the district heating system is approx. 85 -95°C and in winter time this is approx. 110-120°C. This means that the temperature of the condensate can fluctuate between 70 & 115 °C (also depending on sub-cooling in the district heating condenser) and therefore this temperature can be higher or lower than the deaerator operating temperature. The Stork spray type deaerator can accommodate these temperature differences easily.
Operation with one or more pre-heaters out of service/bye-passed
In the event that one or more HP pre-heaters are out of service, the HP-condensate flow to the deaerator will be reduced. However this mode only has a minor effect on the turbine steam flow to the deaerator.
This is not so for the LP pre-heaters. The steam demand from the deaerator will rise significantly due to the reduced pre-heating of the LP condensate. This demand depends on the heating of the LP pre-heater and which pre-heater is out of service. Although these are not normal operating cases it is important to inform Stork about them as these need to be considered during the design of the deaerator.
Steam turbine bye-pass
A steam turbine bye-pass has the largest effect on the design of the deaerator. The increased steam flow