|Fuel and Other Considerations|
Superficially, different biomass fuels have very similar chemical characteristics. Their physical and combustion characteristics, however, vary immensely. Wherever possible, we try to evaluate the way in which the fuel is derived, its physical and chemical characteristics, its ash characteristics and how all these factors vary during the harvest season and how they might impact on boiler availability and environmental emissions.
On the power output side, we look at existing or projected load profiles and how these can best be accommodated. We also consider the required plant availability, the degree of automation required and the present and possible future environmental constraints.
With this background, we select the most appropriate solution to best fulfil the identified needs, looking at the following key parameters in particular:
- thermodynamic cycle
- combustion equipment
- boiler geometry
- gas clean-up equipment
- turboalternator performance profile
- fuel and ash handling facilities
Our concept of using a "steam transformer" to de-couple the factory and powerhouse steam and condensate loops is gaining widespread acceptance. De-coupling prevents contaminated factory condensate being returned to the boiler and hence allowing more sophisticated thermal cycles to be employed.
With our computer based design models we can optimise both boiler and power station thermal characteristics. Our design team has available to it a range of programs, developed in house and bought in, to design and optimize heat and mass balances, process streams and the mechanical engineering of individual components.
Our mechanical design work runs through from conceptual design to the preparation of working drawings. Whilst sometimes this is limited to preparing general arrangements for further development by competent contractors it frequently involves the production of manufacturing drawings for issue to fabricators.
We firmly believe that building inherent operating stability into plant is preferable to spending money on over-sophisticated controls to achieve the same purpose. Nonetheless modern control systems are required on most projects. Although we are able to provide control engineering services we most often work with our Clients' control engineers.