DEVELOPMENT AND APPLICATION OF DEVELOPMENT AND APPLICATION OF

PROMISING TECHNOLOGIES FOR PROMISING TECHNOLOGIES FOR

FIRING COAL-WATER FUELSFIRING COAL-WATER FUELS

Coal-Gen Europe 2008 F. Serant , K. Agapov , A. Kuzmin,

Yu. Ovchinnikov, L. Pugach SibCOTES, NSTU

cotes@cotes.sib.ru

Novosibirsk

Russian Federation

CONTENTSCONTENTS

Problems and prospects for coal-water firing at power generation installations

Problems and prospects for coal-water firing at power generation installations

Experience of application of coal-water fuel at Novosibirsk CHP-5 Plant & Belovskaya PP

Experience of application of coal-water fuel at Novosibirsk CHP-5 Plant & Belovskaya PP

Advanced coal-water technologies developed together with Novosibirsk State Technical Institute &

Novosibirskteploelectroproect

Advanced coal-water technologies developed together with Novosibirsk State Technical Institute &

Novosibirskteploelectroproect

Main conclusionsMain conclusions

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Power industry & coal-water fuel in RussiaPower industry & coal-water fuel in Russia

Tons of coal equivalent

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Advantages of coal-water fuelAdvantages of coal-water fuel

•Long-distance pipeline transition•No explosion hazard

•Lower NOx and SOx emission level

Coal-water slurry is a relatively new type of fuel for small- and large-scale power installations.

It has a number of advantages compared to conventional fuels:

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Requirements for coal-water fuelRequirements for coal-water fuel

•Suitable viscosity - about 0.5–1.0 Pa·s with shear rate 100 s-1

•Certain stability of properties when stored in tanks for 12-18 months•Ensuring the conditions for stable direct combustion: acceptable heating value, reactivity, and good dispersing properties (drops up to 350 μm)

•Fired fuel should ensure efficient combustion, as well as reduced emissions•Eliminate covering and slagging of heating surfaces

General requirements for coal-water fuels:

• Acceptable power inputs per 1 ton of product

• Moderate wear and metal intensity per 1 ton of the product

• Long overhaul life for the elements (mills, cavitators, dispersers, fuel nozzles)

• Automation ensuring proper operation level

General requirements for coal-water fuels production process:

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Coal-water fuel combustion on a 200 MW unit at Coal-water fuel combustion on a 200 MW unit at Belovskaya Power PlantBelovskaya Power Plant

Boiler PK-40-1: •Steaming capacity = 320 t/h

•Furnace heat release rate qv= 130 kW/m3

•Furnace cross-section heat release rate qF= 3.8 MW/m2

•6000 tons of coal-water fuel were fired

Coal-water slurry conditions:

Kuznetsky coal, grades D

(long-flame coal)

Kuznetsky G (gas coal)

Qir =15.1 MJ/kg

Wr = 39%

Ar =9%

Nr = 1.45%

Density ρ=1180÷1220 kg/m3

Viscosity μ = 0.5÷1.2 Pa·s

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Application of coal-water fuel at Novosibirsk Application of coal-water fuel at Novosibirsk CHP-5 PlantCHP-5 Plant

Pilot coal slurry pipeline Belovo – Novosibirsk

• 262 km-long coal slurry pipeline

• 4 million tons of coal-water fuel per year

• 3 million tons of dry coal per year

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Coal-water fuel Coal-water fuel handling and storage systemhandling and storage system

Two tanks

(20 000 m3 each)

with hydro mixers

Compressed air

Air

compressor

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Coal-water fuel combustion Coal-water fuel combustion on boiler at Novosibirsk CHP Planton boiler at Novosibirsk CHP Plant

Boiler performance:• Steaming capacity - 670 t/h • 1 boiler was completely re-equipped for coal-water fuel firing (together with Snamprogetti)• 3 boilers fired it together with conventional Kuznetsky coal (grades D (long-flame coal) and G (gas coal)).

• Low heat release rates - qv = 95 kW/m3 and qF = 3.4 MW/m2.

Coal-water fuel conditions:• Coal concentration in the coal-water fuel - 54.6 - 55.8%• Coal-water fuel density – ρ=1.21 g/cm3• Ash content Ad=9.5 %• Calorific value Qir =13.6-14.4 MJ/kg

Coal quality:

Qir =22,7 MJ/kg

Ad=12.5 %

Wr =14.6%

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Conclusions after coal-water fuel firing at Conclusions after coal-water fuel firing at Belovskaya PP and Novosibirsk CHP-5 PlantBelovskaya PP and Novosibirsk CHP-5 Plant

Switching of the existing PC-fired boilers to coal-water fuel without any additional reconstruction results in the following:

• Lower gas temperature in the flame kernel (by 100-150°С) • Lower cost-efficiency of combustion (by 2.5-3.3%) • Higher gas temperature at the furnace tail (by 35-45°С) and downstream the

boiler by 15-20°С • Lower NOx level under certain conditions (by 25-35%)

To eliminate adverse effects the boilers need some re-engineering, incl.: • Heat insulation of the furnace to increase gas temperature within the flame

kernel• Changed superheater and economizer surfaces• Finer coal grinding• Higher hot air temperature

Transmission system for coal-water fuel (Belovo – Novosibirsk) with conventional milling and mixing with water has some disadvantages:

• Limited time of being in a stable condition • Abrasivity of coal-water fuel, which causes considerable wear of pumps, gate

valves, fuel nozzles, etc.• Need to use surface-active substances

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Cavitation of coal-water fuelCavitation of coal-water fuel

Capacity from 5 to 300 t/h of sourse coal

Coal-water fuel stability – more than 24 months

Technology developed together with

company NovosibirskTeploelectroproekt

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Coal-water technologies developed by Novosibirsk Coal-water technologies developed by Novosibirsk State Technical University (NSTU)State Technical University (NSTU)

Production and supply of composite liquid fuel to boiler

1 – coal hopper2 – crusher3 – feeder4 – desintegrator 5 – separator6 – cyclone7 – FDF8 – PC bunker9 – feeder 10 – cavitators 11 – raw oil tank (oil and fuel oil

residue)12 – daily tank for composite liquid

fuel 13 – recirculation line of composite

liquid fuel14 – water-supply tank15 – peat hopper16 – screen17 – flotation plant 18 – peat gel feed line 19 – feeding pump of composite

liquid fuel20 – feed line of composite liquid

fuel 21 – FDF22 – feed line for coal-water mixture

after the first cavitation stage

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Coal-water production technology Coal-water production technology featuresfeatures

Stability of the system is more than 1 year

Basic methods of stabilization:

• Mechanical-chemical activation of solid phase during grinding in a desintegrator

• Mechanical-chemical activation of liquid phase in a cavitator

• Creation of stable physical-chemical fuel system through profound homogenization of activated phase in a cavitator

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Main equipment for the technologyMain equipment for the technology

Desintegrator output is 3 t/h

Desintegrator is a high-speed mill with percussive-smashing effect.

Activation of coal particles is

realized through deformation

of coal structure and through

creation of micro-defects on

the surface of coal particles.

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Main equipment for the technologyMain equipment for the technology

Cavitator: output - 3 tons per hour ACLF

Cavitator functions:

• Further grinding of solid phase material • Homogenization of liquid and solid particles mixture• Creation of stable physical chemical liquid fuel system

Major feature - Shock-thermal effect in the cavitator zone;

This impact leads to:

-activation of liquid

- destruction of connections in the clusters of the liquid

- creation of free radicals and active molecules.

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Production of synthetic Production of synthetic composite liquid fuelcomposite liquid fuel

Production of synthetic composite liquid fuel:1 – coal tank; 2 – coal feeder; 3 – crusher; 4 – disintegrator; 5 – mixer with water; 6 – cavitator; 7 – intermediate tank; 8 – tank for finished composite liquid fuel

Main technical characteristics of the new technology:•Specific energy consumption ~ 14-17 kW per ton of product•Specific metal consumption ~ 0.45-0.50 t per ton of product in terms of the main equipment

•Reasonable cost of equipment•Production area ~ 8 m2/t

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Module for synthetic composite fuel productionModule for synthetic composite fuel production

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Received fuels & their combustionReceived fuels & their combustion

Received fuel:

Line 1: Wr = 64 %, coal – 20 %, peat – 8 %, oil – 8 %, Ad =28 %;

Line 2: Wr = 54.5 %, coal – 45.5 %, Ad =27.8 %;

Line 3: Wr = 56.05 %, coal – 17 %, peat – 10 %, fuel oil – 17 %, Ad =19.5 %;

In addition, coal-based fuel without any peat component was received:

Line А: Wr = 35.5%, coal – 39.5%, oil - 25%, Аd = 10.3 %;

Line G: Wr = 48.6%, coal – 43.4%, oil - 8%, Ad= 19.5 %.

Mail results of fuel lines studies: • Viscosity of the synthetic composite liquid fuel does not depend on the temperature within the operating temperature range and on the shear rate within the operating velocities, it depends on the composition and is similar to operating viscosity of fuel oils. Synthetic composite liquid fuel is a thixotropic fluid. • Combustion process confirmed reliable flame ignition of sprayed synthetic composite liquid fuel and its independent stable combustion.

• Emissions when firing coal-water fuel are: NOx = 50-100 mg/Nm3 (with O2 = 6 %), SO2 =140-200 mg/Nm3.

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ConclusionsConclusions

• Presented technologies make it possible to produce a fundamentally new type of synthetic fuel based on coal, water and other components;

• Rheological, sedimentation, heat-and-power requirements for this fuel were defined;

• In order to burn synthetic composite fuel on existing PC-fired boilers with good efficiency, it is necessary to reconstruct such boilers;

• The fuel meets the requirements set for the coal-water fuels;• New composite fuel can be used both for firing in various

combustion chambers, and as a fuel for internal-combustion engines, gas turbine fuel and fuel for gasifiers, or instead of oil fuel for boilers and TPPs;

• Research works for the preparation and combustion of synthetic composite liquid fuel making use of local fuels (different grades of peat), coal treatment products, wood waste, farm and oil refinery waste are still in progress.

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Thank you for your attention!Thank you for your attention!