Energetische Nutzung halmgutartiger Biomasse - Abfallratgeber ...

Energetische Nutzung halmgutartiger Biomasse: Stand der Technik und Perspektiven
By crane the straw bales are transported to the boiler and lowered into
ducts located at two opposite walls of the furnace. The straw bale is
pushed into the furnace while burning, and burning straw layers fall on a
vibrating grate on which they burn out. The wood chips are fed to the furnace
through three air spouts. The flue gas is cleaned in a bag filter with
an inlet temperature of 130 °C.
Grenaa CHP
The plant in Grenaa is a Circulating Fluid Bed (CFB) plant that was put
into operation in January 1992. The steam data are 29 kg/s / 92 bar /
505 °C at a feedwater temperature of 170 °C. The plant delivers heat to the
city of Grenaa, process steam to industry and power to the national grid.
The boiler is designed for firing 100 % coal or a mix of coal and straw
with up to 60 % straw. At a 50 %/50 % mixture of coal and straw the plant
consumes 38,000 tonnes of coal and 70,000 tonnes of straw. During the
latest years of operation, other types of biomass such as spoiled corn or
waste products from production of vegetable oils have been utilised in
the plant.
Limestone is injected into the combustion chamber for desulphurisation,
and the combustion air is staged for reduction of the NOx emission.
Further, the flue gas is cleaned for dust particles by means of an electrostatic
precipitator.
The plant has suffered from severe corrosion problems and has been
modified several times. In the latest modification the final superheater
was relocated from the convective pass to a fluid bed heat exchanger located
in the return leg of the circulating ash circuit.
Extensive tests have been conducted at the plant over the years and
these tests together with the operating experience have paid a significant
contribution to the knowledge on corrosion and slagging/fouling problems
as well as knowledge on CFB-specific problems such as erosion/corrosion.
Biomass boiler at EV3
At the power plant Sønderjyllands Højspændingsværk a once-through
bioboiler with live steam pressure of 200 bar has been in operation for
more than three years. The annual fuel consumption of the plant is
106