DEVELOPMENT AND APPLICATION OF

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DEVELOPMENT AND APPLICATION OF PROMISING
TECHNOLOGIES FOR FIRING COAL-WATER FUELS
Coal-Gen Europe 2008 F. Serant , K. Agapov ,
A. Kuzmin, Yu. Ovchinnikov, L. Pugach
SibCOTES, NSTU cotes_at_cotes.sib.ru
Novosibirsk Russian Federation
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CONTENTS
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
Advanced coal-water technologies developed
together with Novosibirsk State Technical
Institute Novosibirskteploelectroproect
Main conclusions
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Power industry coal-water fuel in Russia
Tons of coal equivalent
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Advantages of coal-water fuel
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

• Long-distance pipeline transition
• No explosion hazard
• Lower NOx and SOx emission level

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Requirements for coal-water fuel
General requirements for coal-water fuels

• Suitable viscosity - about 0.51.0 Pas 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
production process

• 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

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Coal-water fuel combustion on a 200 MW unit at
Belovskaya Power Plant
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 ?11801220 kg/m3 Viscosity µ
0.51.2 Pas

• 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

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

• 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 handling and storage system
Two tanks (20 000 m3 each) with hydro mixers
Air compressor
Compressed air
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Coal-water fuel combustion on 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 ?1.21 g/cm3
• Ash content Ad9.5
• Calorific value Qir 13.6-14.4 MJ/kg

Coal quality Qir 22,7 MJ/kg Ad12.5 Wr
14.6
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Conclusions after coal-water fuel firing at
Belovskaya 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?)
• Lower cost-efficiency of combustion (by 2.5-3.3)
  
• Higher gas temperature at the furnace tail (by
  35-45?) and downstream the boiler by
  15-20?
• 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 fuel
Technology developed together with company
NovosibirskTeploelectroproekt
Capacity from 5 to 300 t/h of sourse
coal Coal-water fuel stability more than 24
months
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Coal-water technologies developed by Novosibirsk
State Technical University (NSTU)
1 coal hopper 2 crusher 3 feeder 4
desintegrator 5 separator 6 cyclone 7
FDF 8 PC bunker 9 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 fuel 14
water-supply tank 15 peat hopper 16 screen 17
flotation plant 18 peat gel feed line 19
feeding pump of composite liquid fuel 20 feed
line of composite liquid fuel 21 FDF 22 feed
line for coal-water mixture after the first
cavitation stage
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Coal-water production technology features

• 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 technology

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

Desintegrator output is 3 t/h
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 technology

• 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.

Cavitator output - 3 tons per hour ACLF
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Production of synthetic 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 production
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Received 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 ? Wr 35.5, coal 39.5, oil - 25, ?d
  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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Conclusions

• 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!