Type of CHP system: Grate fired boiler

Plant owner: The plant is owned by: Tiroler Wasserkraft AG 48%, Steirische Gas Wärme AG 48 %, Stadt Lienz 4%

Commissioned: 2000

Status of plant: Commercial

Contractor details:

Thermo oil boiler and hot water boiler: Kohlbach; ETA 6000-40 V and ETA 7000-40 V; ORC: Turboden; Oil boiler: Loos; Solar Plant: Solid, Flue gas cleaning: Scheuch; Thermooil-heat exchanger: Ingertherm

Power generation: ORC

Main fuel: Wood chips

The plant uses mostly (1)  farmers wood chips (10,760 t) with a moisture content of 35% (2)  bark (7,800 t) and (3) sawdust and sawmill residues (7,800 t) both with a moisture content of 50%.

Nominal capacities & efficiencies:

Thermal input, biomass & waste: 29,7 MW

Total thermal input, incl. fossil fuels: 29,7 MW

Gross electrical output: 1,1 MWe

Net electrical output: 1 MWe

Heat output: 12,2 MJ/s

Electrical efficiency, gross: 18 %

Overall efficiency, gross: 90 %

Power to heat ratio: 0,21

The nominal thermal input capacity of the plant is composed as follows: thermooil boiler 8 MW, Hot water boiler: 8,2 MW, ECO: 1,5 MW, Oil boiler: 12 MW. The net heat output is 22,8 MW composed as follows: Thermooil boiler: 4,8 MW , hot water boileR: 7 MW, ECO: 1 MW, Oil boiler: 10 MW

How is plant controlled: Plant is controlled by the heat demand.

Heat backup: Oil fuelled back-up boiler with a nominal thermal input capacity of 12 MW.

Heat usage: Heating only

Energy usage:

The plant supplies approx. 3,300 clients in the town of Lienz with district heating. The annual heat supply is of appr. 55,000 MWh. The electrictiy production is about 5,000 MWh. The network has a lenght of 37,500 m, and connect 900 houses.

DH inlet temperature: 95 °C

DH return temperature: 60°C

Fuel storage: The fuel storage has a capacit yof approx. 25,000 m3  corresponding to 24 hours of operation at full load.

Ash discharge: The annual amount of ash amounts to approx. 300 tonnes, of which 100 tonnes are used as fertilizers in agriculture and forestra, and about 200 tonnes are landfilled

Plant description:

Basically the plant is composed of two biomass boilers (thermo oil boiler and hot water boiler), a CHP-module based on ORC-Process, a solar thermal plant, and an oil boiler with a multi-stage flue gas cleaning with integrated heat recuperation. The plant supplies the city of Lienz with district heating and feeds the electricity produced in the ORC-Module as eco-electricity into the public grid. The connection of more than 800 central heating plants to the district heating grid aimed at reducing emissions in Lienz. The use of biomass from the Eastern Tyrol Region aimed at increasing added value considerably.

Fuel feeding system: The fuel feeding occurs manually.

Flue gas cleaning:

After the removal of large fly ash particles by means of a  multi cyclone the flue gas of the biomass boiler arrives in the flue gas cleaning plant, composed mainly of an econo-miser, a wet electrostatic precipitator, and an air pre-heater.  The residual heat is recovered in the economiser, whereby the flue gas is colled down to 90°C, which flows through the wet electrostatic precipitator. The wet electrostatic precipitator cleans the flue gas to a level of particle content of about 10 mg/Nm3. Afterwards the flue gas is led to the air pre-heater where the heat exchange between flue gas and outer air occurs. Hereby the fluegas is dehumified and the outer air is pre heated. Both gas streams are mixed within the chimney, to avoid the development of plume til an outer temperature of – 5°C.

Electricity sale info: The feed in rate in Austria is regulated by law and depends on the type of biomass used and on the size of the plant.

Data collected and quality assured by: Austrian Energy Agency.

Contact person: Elvira Lutter