SWE Energie (Stadtwerke Erfurt Energie GmbH) operates an 80 MW gas and steam turbine CHP in East Erfurt, consisting of two gas turbine heat recovery boilers and a shared steam turbine. Each heat recovery boiler is supported by auxiliary firing equipment generating 30 - 80 tons of steam (40-80 bar) per hour in a sliding pressure operation, depending on the demand.

The steam is fed to a back pressure steam turbine, producing electricity and generating district heating at up to 110 MWth in a heating condenser unit. In addition, the plant supplies steam at 9 bar for heating purposes to a large individual customer.

SWE Energie wanted to replace the auxiliary firing system and increase the production of electricity and heat. It therefore decided to expand its facility by building a new, third gas turbine heat recovery boiler. In order to further optimise the operation of the CHP, a heat accumulator with a capacity of about 250 MWh was integrated into the district heating network at the same time.

SWE Energie contracted Sweco to conduct all planning services and supervise the construction and commissioning of the works, which we did, keeping downtime at the existing plant to a minimum.  

Technical Data - Line 3:

• Gas turbine power output: approx. 35 MW electricity
• Steam output: approx. 43 t/h
• Steam parameters: 40 - 80 bar / 410 - 505 °C
• Technical data heat accumulator
• Total capacity: 250 MWh, around 7000 m³
• Water parameters: 75 - 100 °C, pressureless  

Sweco’s Services:

General planning, supervision of construction and installation, as well as commissioning.