**3. Diagnostic methods for operating surveillance of large fluidized bed boilers**

Once large units are put into operation during co-combustion of alternative fuels and coal, guaranteed-performance tests must be conducted. The aim of the guaranteed-performance tests is to verify design parameters. Guaranteed-performance figures are compared with reality. Apart from basic measurements there are a number of other similar measurements of specific equipment parts that might be initiated because: the manufacturer is interested in using the experience to improve or design new units and the operator is interested in both eliminating problems and improving the economics of the operation process - Table 4. (Čech 2006). This chapter reviews the development of verification methods and presents some equipment for the determination of all important and interesting measuring data. The conclusions might be useful to energy companies and operators that want to verify operation data of fluidized bed boilers, flue gases and air channels.

Diagnostic measurements at a particular unit basically cover:


The model research verify if the alternative fuel produced from biomass and sewage sludge may be used as alternative energy source in respect of the EU legislation, and/or its other modifications (with additives, decontamination technologies) for suitable fuel, which would comply with emission limits or the proposed energy process optimizing the preparation of

The limiting factor for sewage sludge utilization from WWTP (waste water treatment plant) in agriculture is the increased content of risk elements and also the occurrence of organic pollutants – primarily polyaromatic hydrocarbons, PCB (polyaromatic byfenyls) and AOX (adsorbable organic halid). Other alternative fuels have not these limiting conditions. The limiting factor for sludge combustion at incineration plants is water content. With regard to the fact that from 2005 the EU Directives EU expects to ban waste disposal sites with any material with content of organic substances above 10 %, it is apparent that the priority condition for sludge utilization is sludge decontamination or power engineering utilization (Loo & Kopperjan 2008). Results from tests may be evaluated as very good with the prerequisite for utilization, testing of investigated substances in real combustion units. On the basis of carried out laboratory and pilot tests one may expect good results from these real units (equipment with greater output), many of these experiments have been already performed. From the results of experiments and thermoanalytical studies it is clear that 15 % of alternative fuels – biofuels based on sludge and brown coal can be used in the large fluidized bed boilers located in the Czech Republic. The combined combustion will enable to fulfil the Czech Republic's pledge to the European Commission concerning the

coal/sludge mixture for combustion in the existing power engineering equipment.

**3. Diagnostic methods for operating surveillance of large fluidized bed** 

Once large units are put into operation during co-combustion of alternative fuels and coal, guaranteed-performance tests must be conducted. The aim of the guaranteed-performance tests is to verify design parameters. Guaranteed-performance figures are compared with reality. Apart from basic measurements there are a number of other similar measurements of specific equipment parts that might be initiated because: the manufacturer is interested in using the experience to improve or design new units and the operator is interested in both eliminating problems and improving the economics of the operation process - Table 4. (Čech 2006). This chapter reviews the development of verification methods and presents some equipment for the determination of all important and interesting measuring data. The conclusions might be useful to energy companies and operators that want to verify

The measurement of fluidized bed temperatures, furnace temperatures, flue gases

 The measurement of flue gas velocity in the furnace chamber and exits of cyclones, in cyclones, at the cyclone exit to second pass as well as in the area of additional boiler

Sampling of characteristic solid ash particles including isokinetic sampling to determine

development of renewable energy resources by 2010.

operation data of fluidized bed boilers, flue gases and air channels.

temperatures at ancillary heating surfaces up to the boiler.

Diagnostic measurements at a particular unit basically cover:

surfaces, sampling of flue gas in the boiler.

solid particle concentrations.

**boilers** 


HC – hard coal, BC – brown coal, BIO – biomass , Tph – tons steam per hour - output Table 4. Newly-built fluid boilers with circulating fluid layer in the Czech Republic
