References

BIOCIRC GROUP GRØNHØJ

950 kW wood and gas boiler system in a container for combined heating with wood and gas

BIOCIRC GROUP's biogas plant, which produces significant amounts of biogas from materials including deep litter, maize, grass silage, straw, and slurry (approximately 140,000 tons per year), aimed to convert the biogas/methane into natural gas.

Therefore, Linka Energy was chosen by BIOCIRC GROUP as their partner for this project, as we have the know-how and experience in handling biogas. We use an absorber-stripper system with amine to clean and upgrade the impure gas into clean gas before it is further distributed into the natural gas network.

In 2017, BIOCIRC GROUP and Linka entered into an agreement to establish a complete Linka Energy 950 kW biomass and gas boiler system for firing with wood chips and biogas, all built within a container. The design of the system is based on the economic advantage of using wood chips and biogas for heating at different times of the year, regardless of fluctuating price levels.

The combination of these two types of fuel contributes to ensuring BIOCIRC GROUP a stable, cost-effective, and CO2-neutral heat supply.

The plant

The completely new system, a 950 kW Linka H 2000 wood chip boiler and hot water boiler, along with a Global H3 gas boiler, is equipped with Linka's patented combustion technology to ensure maximum utilization of the fuel.

The boiler system is built in a container that was assembled at Linka, with the main components also being installed there before it was transported to BIOCIRC GROUP.

The wood chips are unloaded and stored in a wood chip pit, from which Linka's scraper system conveys the fuel to a “sunken” cross auger, which then moves it into an inclined auger and directly into the cell lock and into the boiler via the stoker auger. The scraper system is automatically activated by a signal from the control system when the boiler's firing procedure is initiated.

The hot water boiler is a LINKA H 2000 channel tube boiler in a 3-pass design with a smooth combustion chamber and water-cooled turning chambers, designed for complete combustion and efficient utilization of radiative heat, while convection heat is utilized in the tube sections.

Inside the boiler’s combustion chamber, there is a movable grating to minimize slag formation, and the counterflow combustion system is Linka’s patented global system.

On the boiler, there are 8 pressure tanks with attached blow-off valves for air.

The blow-off valves shoot air through the boiler tubes, thereby cleaning them of ash, which means that the boiler tubes rarely need to be cleaned.

Additionally, a compressor has been provided for the system.

The cleaned flue gas results in a significant reduction in dust emissions before it is released through the 15-meter-high steel chimney.

The ash is transported via the automatic ash removal to a 5 m³ ash container, which is equivalent to approximately 14 days of operation at continuous full load, 24/7.

The gas boiler is a LINKA Global H3, “LUX” in an extended and vertical version, designed for gas firing, and it comes equipped with a Weishaupt burner, type WM G20/3-A. For the gas boiler, a water treatment system with chemical dosing, an expansion system, and a pressure maintenance system have also been provided. The boiler is connected to the exhaust system, smoke and pipe installations, and the chimney.

The gas boiler is primarily used as a backup for the hot water boiler and is prepared to burn oil instead of gas.

The control of the complete system is managed through a PLC control system, which monitors the system and thus ensures controlled regulation of fuel supply and operation, ensuring maximum efficiency is always achieved from the system.

The PLC system sends out alarms in case of deviations from the pre-set points via the internet and SMS, and it will also be possible to monitor the system through smartphones, tablets, and/or PCs.