Comparison Between CWS Atomization Combustion System and CWS Fluidization Combustion System
Coal Water Slurry Boilers Combustion System has developed to the second generation ( Fludization Combustion System). What’s the difference of first generator technology(Atomization Combustion System) with Second Generation(Fluidization Combustion System)
1. Theory of combustion,
CWS atomization combustion system CMW burner inject CMW to the furnace to fire, like oil fired boiler.
CWS fluidization system
2. Requirement for coal to make Coal-water slurry:
CWS atomizer system is subject to the variety of coal quality, the CWS fuel must be made of high calorific coal.
CWS fluidization system can adjust to different quality coal material, from high quality coal , high ash content and low calorific washing coal slime to anthracite.
3. Requirement for diameter of coal-water slurry particle.
CWS atomizer system has a high requirement which need the coal particle smaller than 45μm; the manufacture cost is very high.
CWS fluidization system has a lower requirement for particle size. the 2mm size particle is also suitable for this system, which reduced the Coal-water manufacture cost.
4. Operation reliability
CWS atomizer combustion system has high combust temperature, easy to happen serious coking phenomenon, for the small type CWS boiler, furnace volume heat release rate is very high, usually use turbulent burner, it is hard to balance stabilization of combustion and coking. It is difficult to prevent ash from coking in such a high temperature which will have an effect on the safety operation of the boiler.
CWS fluidization combustion system , high efficient and clean combustion way make sure fluidization combustion achieve high performance and prevent the coking happening.
5. Requirement for before-furnace system and nozzle.
CWS atomizer system has a complex before-furnace system, which need to be equipped with stirrer , filter etc. the life span of nozzle is about 1500h, which still have a long way to develop.
CWS fluidization system has a simple before-furnace system, which has a very low requirement for density and purity of CWS, and do not need special designed nozzle.
6. Desulfuration inside boiler
CWS atomizer system which adds limestone to the CWS will have a bad influence on the efficiency and the desullfuratioin effect don’t show a good performance.
CWS fluidization system: a high efficient and clean combustion way achieve high performance of desulfuration. When Ca/s=2, the desulfurization degree reach 80%.
7. Requirement for pressure of CWS and Medium of atomizer:
CWS atomizer combustion system has an strict requirement for pressure of CWS and Medium of atomizer which require 0.2t compressed air to burner 1t CWS.
CWS fluidization combustion system has no requirement for above pressure
8. Slag and ash remove system
CWS atomizer combustion system has a complex slag and ash remove system which make the comprehensive use hard.
CWS fluidization combustion system high efficient clean combustion way can continuously operate without Slag and ash remove process. This combustion way reduce the consumption of combustible material in the ash and slag and increase the efficient.
9. Load adjustment range:
CWS atomizer combustion system: too low temperature will influence the stable operation of CWS atomizer combustion system, so the load range is 50%-100%
CWS fluidization combustion system has a wide Load range which is 30%-100%
10. Star and Run
CWS fluidization combustion system is easy to ignite, when the temperature of the bed reach 400 0C , the CMS can be feed to fire. The Start process consumes much less oil. Easy to start and maintain, which reduce the worker number.
11. Consumption of Power and bed material
CWS fluidization combustion system consume more power and need to feed fluidize bed material.
CWS atomizer combustion system: 85%
CWS fluidization combustion system: 88%