Energy Systems
Water wall boilers
Highly efficient solution for generating steam
Water wall boilers constitute a highly efficient solution for generating steam as they use natural circulation to pass the boiler water through water walls that are located directly in the combustion chamber and the downstream boiler passes. This type of boiler achieves excellent heat transfer performances by directly utilising the radiant energy. The compact design reduces the required space and allows the usage of multiple types of fuels, including biomass, coal, oil, gas as well as recycled fuels. The smaller surface reduces the use of insulation material and minimizes radiation losses, ultimately leading to increased system efficiency.
We manufacture two variants of the water wall boiler:
Top-fired water wall boiler
Grate-fired water wall boiler
At a glance:
- Steam output up to 120 t/h
- Generation of superheated steam combined with a turbo generator to produce electrical energy
- Thermal oil heating by saturated steam (in case of CHP) or by convective bundles with the possibility of heat displacement between the thermal oil system and the water steam circuit
- Direct steam generation with flue gases from the biomass combustion
- Consumers are for example defibrators or refiners, wax melters, separators and building heaters
- Use of granulate and dust burners possible at any time
- Design, calculation, construction, manufacture and inspection in accordance with EN, ASME or GOST standards etc
Details
The robust engineering associated with water wall boilers ensures high resistance to thermal loads and extends the service life.
A high proportion of machine welding also contributes to cost efficiency. It also minimizes the need for brick linings and refractory materials, which in turn reduces investment and maintenance costs. If necessary, partial damaged areas of the walls can be cut out and replaced. As most of the water walls are not lined with refractory, there is no need to remove and reapply refractory material.
Damaged areas can therefore be replaced quickly, resulting in reduced downtimes.
Water wall boilers are particularly suitable for combined heat and power plants as they can provide superheated steam to produce electrical energy in addition to saturated steam for the processes. This increases the independence from the general power grid while improving production reliability.
By using turbine bleed points, other processes can be supplied and low temperature consumers such as building heating systems can be fed with turbine exhaust steam. The high efficiency and flexibility during load changes ensure a continuous supply of steam and low operating costs compared to other boiler types.
Two variants
1. Top-fired water wall boiler:
This type of boiler uses a burner positioned at the top of the combustion chamber.
Heat is transferred by radiation exchange between the downward facing burner flame and the water walls as well as by convective bundles in the second boiler pass that utilize the residual heat from the flue gas. This type of design is particularly suitable for generating saturated steam.
2. Grate-fired water wall boiler:
This version uses water walls in the combustion chamber, which can be protected with a layer of refractory material. The use of granulate and dust burners is possible at any time.
In the first pass heat is transferred by radiation exchange between the grate flame and the water walls, which already lowers the temperature in the combustion chamber. Depending on the requirements, the boiler can be designed with vertical passes only or in combination with a horizontal boiler pass. This design is suitable for generating saturated steam and for the combined generation of heat and power.
Top view
Boiler cut
