heat content.This has become increasingly difficult as the range of fuels used has broadened and as the properties of many of the new fuel options vary from batch to batch. As a result, existing
plants are faced with new sets of problems and difficulties in running their operations.
In the case of new plants, the problem is often one of insufficient data on dimensioning needs and a lack of experience
with the relevant operating parameters. Engineering and implementation are complicated further when different fuels are mixed. Additional problems are faced by manufacturers supplying power plant and fuel handling
systems for export to countries where the range of fuels on offer can be very different from what the supplier is familiar with.
Fuel handling systems represent a sizeable proportion of power plant investment, typically
4-9%, but sometimes more. The maintenance costs of fuel handling and feed systems compared to investment costs are in excess
of 5% a year. However, the impact of these systems on the availability of a multifuel-fired plant is significant.
The three-year programme includes all of Finland's major companies involved in
producing, using, and manufacturing equipment for solid fuels, as well as various forest
products companies and systems suppliers. The programme will review all the activities and technologies used in fuel production
and transport until it reaches the boiler door. The multifuel streams to be studied include all wood and peat-based fuels and other biomass materials, such as bark; recycled and waste-derived fuels; paper and plastic
that cannot normally be reused; waste sludge produced by the forest products industry; and coal and lignite.
RANGE OF PROJECTS
As part of work to evaluate equipment failure, cost levels, and availability, the
programme will look at the multifuel handling systems used in tens of industrial and municipal power and heat plants around Finland and some in Sweden.
In collaboration with a group of equipment manufacturers,
VTT Energy has designed advanced test equipment for fuel crushing and unloading applications that manufacturers can use in developing new end-applications. A system based on artificial vision technology has also been
tested for recognising multifuel composition and regulating feed levels.
The programme has drawn up a quality classification system for wood fuels, and proposed an equivalent system for recycled fuels. A databank
on the critical properties of various solid fuels has been created for use by equipment manufacturers in designing new and improved systems. Other work has concentrated on testing corrosion and erosion questions in fuel
handling equipment manufactured from conventional and new materials when handling new types of fuel.
Another sub-project within the programme is devoted to expanding and developing the use of automatic or
mechanical sampling for wood and peat, and possibly also recycled fuels based on waste materials. Safety is also a subject of attention, and tests have been carried out to establish dust explosion and self-ignition
behaviour and thereby improve fuel handling safety.
For more information contact the CADDET Finnish National Team in Helsinki.