Kronospan biomass cogeneration plant
Supply of valves for the water/steam circuit of a biomass cogeneration plant in Luxembourg.
- Control valve package consisting of:
- 17 Control valves
- 2 injection coolers
- 2 three-way valves (TRIVENT)
- 2 steam conversion stations (POWERTROL)
- Consulting, manufacturing, commissioning
- Control of a water/steam circuit in the low-pressure and high-pressure range
- Pressure / nominal pressure rating: up to 130 bar / PN160
- DN / Nominal size: DN25 to DN250
The biomass cogeneration plant
Kronospan Luxembourg S. A. is an international manufacturer of particleboard, MDF, OSB, laminate flooring and worktops. The company has made extensive investments as part of the EU “factory for the future” project to significantly reduce CO2 emissions and the environmental impact of the production facility.
As one measure, the company Bertsch Energie from Austria was commissioned with the planning and delivery of a biomass cogeneration plant, which was to be controlled with a first-class valve concept, state of the art.
The production of wood products requires a lot of energy and heat. At the same time, the production process generates wood residues, which are ideal energy sources for cogeneration. With this concept, wood that has reached the end of its utilization cycle, but also recycled wood that is unsuitable for material recycling, can be thermally recycled. Fossil fuels can thus be replaced by renewable energies.
Use of our ARCA control valves
ARCA-Regler supplied almost all control valves from control to cooling for the construction of the biomass cogeneration plant. For the water-steam-condensate circuit including the valves around the steam drum, the boiler, the feedwater tanks and the condenser.
The ARCA Group level control valve for the steam drum is used to regulate the level of the feedwater in the steam drum. In normal power plant operation, the application is not very demanding. Here, however, cavitations can occur during startup due to the high differential pressure. Cavitation can be prevented or its influence minimized by means of a multistage trim, part of the ECOTROL modular system. The feed water from the steam drum is fed to the biomass boiler, evaporated and fed to the steam drum. After the reheaters, the steam is controlled to a defined temperature by the Artes Desuperheaters. Via the start-up control valve, which is equipped with an internal trim for noise reduction, the steam is blown out via silencers during start-up of the plant, while during operation the steam drives a turbine for steam generation.
In the case of a turbine failure, all the steam is diverted via two steam conversion stations. The high steam pressure there is reduced via several control and fixed stages and simultaneously cooled with the integrated ARCA dual-fuel nozzle in the center of the pipeline.
These valves are of immense importance for the availability and safety of the plant, which is why they can close within 2 seconds via a 1oo3 control as well as open via a solenoid valve. The steam test stick for safeguarding the steam pressure after the bypass station was part of the scope of delivery and the safety concept.
Three electronic pressure switches, installed in a control cabinet, monitor the pressure in the outlet pipe and, if exceeded, control the steam-converting station, which moves to the safety position.
After the turbine in the biomass cogeneration plant, the steam enters the condenser, which is under vacuum. The better the vacuum, the higher the efficiency of the turbine. The air that enters the condenser undesirably is removed via jet pumps. The motive steam for supplying the jet pumps is adjusted in each case by a control valve. Sootblower valves supply steam to the sootblower system to remove the deposits of residue from combustion on the boiler tubes.
Special features of the ARCA control valves used are:
- High-pressure steam forming station type 560 with quick venting unit and steam test rod as safety valve against excess pressure
- Special characteristic for control in start-up process
- Multi-stage controlled subcritical pressure reduction for low wear and noise reduction
- Low and high pressure control valves as well as special valves from one manufacturer
For the customer, the cooperation with ARCA resulted in several advantages. Firstly, having a manufacturer for both the standard control valves and the highly stressed valves at his side. Secondly, a partner who provided support throughout the entire value chain, from consulting and production to commissioning.