05. April 2009
Exhaust Gas-Heated Steam Generation System with 13 MW Steam Output
The installation of exhaust gas-heated steam generators in cogeneration plants helps to reduce the primary energy demand as well as ultimately minimising operating costs while also cutting CO2 emissions.
The following example demonstrates the benefit of an engine-operated cogeneration plant with exhaust gas-heated steam generators.
With an engine output of approx. 30 MW, this plant based in South-East Europe delivers
approx. 19.5 t/h saturated steam at 6.5 bar gauge. Only the exhaust gas heat of the engines is used to generate the steam.
The resulting saturated steam is continuously employed for steel production at the nearby industrial park. Efficient exhaust gas heat recovery from the engines boosts the overall efficiency of the plant to over 80%. Compared with the separate generation of power and thermal energy, a primary energy saving of approx. 40% is thus achieved by reducing the consumption of fossil fuels.
According to the operator the plant saves some 185,000 tonnes CO2 equivalent each year, so allowing the company to sell emissions certificates.
Every steam generator at the plant is heated by two engines. Here the exhaust gas paths are kept completely separate to prevent the engines influencing each other. Should there be a reduced demand for steam, the steam output of each engine can be "switched off" by bypassing the steam generator.
The production of steam and communication with the engines is ensured by a control panel with the APROVIS Controlling System (ACS) for each steam generator.
A high level of boiler availability is also guaranteed by means of modem-based remote maintenance/diagnostics.