Objetivo
To consider the conversion of a 20 year old 15,900 kg/h steam capacity AGM 132 Packaged Boiler originally designed for fuel oil firing; to coal-water fuel, and to further the technology of coal-water mixtures on a commercial scale.
The coal water mixture (CWM) fuel feed system and burner equipment was commissioned. The CWM pumping system was subjected to a 24 hour continuous circulation test in which fuel was circulated through the feed pipe system and back to fuel storage: this yielded important information on pump performance and was regarded as a successful commissioning.
When CWM firing trials began, the burner gun repeatedly blocked. Since cleaning failed to resolve the problem a thorough investigation revealed that the blockage arose from the burner management control sequence. In this, the sequence of CWM firing injects water for a short period, followed by an air purge after which (it was intended) CWM fuel flow begins. Tests showed that in the process of blowing out hot water, the air purge left the gun tip very hot: this caused fuel blockage in the gun.
After modifications to the burner block, involving a manual water valve into the fuel inlet, CWM firing trials recommenced at various pressures at+/- 20 to 50% MCR loads, revealing two further problem areas:
- being at the same levels, the auxiliary oil gun caused oil contamination and coking in the CWM gun tip;
- unburned CWM close to the 'Magic Eye' flame failure monitor, tripped the boiler at the begining of each test.
Combustion and commissioning problems already outlined led to delay in the boiler test programme.
In view of continued low oil prices, a reassessment of the economic potential of this technology was undertaken. The continued low oil prices so changed the market potential that it was decided that it would serve no further purpose to continue with the work programme. Although all the tests were not completed, the engineering was completed and a final report detailing this is finalised.
The demonstration programme would be being carried out on the 10 MW boiler located in the Foster Wheeler works at Hartlepool. Apart from conversion of the boiler to CWM combustion the following elements are to be investigated:
* coal-water mixtures will be fired at three loads;
* assessment of the following will be made:
- carbon burn-out;
- boiler efficiency;
- flame characteristics;
- heat release rates;
- fouling/slagging potentials and emission levels.
* a correlation between data from preliminary runs on a 300 kW combustion rig and the boiler will be established for fuel evaluation and design assessment;
* gaseous and particulate emission levels will be measured to assess environmental impact of CWM use;
In Phase I a detailed design study will be made prior to boiler modifications.
Convocatoria de propuestas
Data not availableRégimen de financiación
DEM - Demonstration contractsCoordinador
NW1 7QN London
Reino Unido