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Indo German Energy Programme

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Annexure IX Date 09.09.2008

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D:\Guptha\Steag\GTZ\Output 1\Output1.1\Final report 23 July 08\Annexures\NEW AnnexureIX.doc

9. Basis for measurements and parameters to be monitored

9.1 Fuel

Coal is a natural product. For this reasons its chemical, physical and technological

properties depend on the herbal starting substances and the geometrical conditions during

carbonisation. The knowledge of chemical, physical and technological properties of coal is

of utmost importance for its use as fuel in combustion plants. A German Standard,

DIN 51700, defines the most important analysis procedures for the uniform description of

properties of solid fuels.

To assess the coal, a distinction is made between the pit coal as delivered and the water

and ash -free substance (waf). The moisture and ash-free substance contains only the

burnable parts of the solid and volatile elements. Prerequisite for smooth operation are the

knowledge of and information about these characteristics and properties.

The following overview shows the most important characteristics:

Calorific value

Ash content

Water content

Volatile elements

Sulphur content

Elementary analysis of the ash

Melting behaviour of the ash

Mineral size fraction of the pit coal

Composition of the mixture

Elementary analysis of the coal

Apparent weight

Grinding fineness of the pulverised fuel

Grindability of the coal

If the fuel sample is taken from the material as delivered, it is called "raw". Water-free (waf)

is the term for the fuel dried at 106C until reaching constant weight. The water- and ash-

free fuel results from deducing the ash content from the water-free fuel. This does not

correspond exactly to the ballast ratio, as during ashing the mineral portion may partly

change.


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9.2 Heat ing value

To assess the heating value, the two terms upper heating value and lower heating value are

of importance. The upper heating value (Ho) is the amount of heat released during the

complete and perfect combustion of a certain amount of fuel. During the combustion, the

water content must be evaporated by the flue gases. For this reason, the water evaporation

heat must be deducted from the upper heating value (Ho) in order to receive the actual

lower heating value (Hu).

9.3 Wate r content

The moisture content of the coal, which is relevant for assessment and calculation, is

composed of the rough and the hygroscopic moisture. The rough moisture or surface

water is the moisture, which evaporates when the fuels are exposed to air at room

temperature.

The hygroscopic moisture is the moisture, which additionally evaporates during drying of

the fuels at 106 C.

In order to determine the total moisture content, 100 g of coal is weighed accurately to

0.01 g in a shallow dish and dried until reaching a constant weight after about 3 hours.

100c

bacontentWater

= [%]

a = dish and coal (moist) [g]

b = dish and coal (dry) [g]

c = coal (moist) [g]

9.4 Ash con ten t

The determination of the ash content is supposed to provide information on the content of

inorganic (non-burnable) elements.


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The term "ash" refers to the combustion residues of the solid elements obtained at a

temperature of 815C. This residue is coadunate with the coal b ut a loosely mixed-in part

of the extracted material.

In order to determine the ash content according to DIN 51701, 1 g of processed coal is

weighed accurately to 0.0001 g. Together with the porcelain dish, the sample is inserted

into the cold muffler, and then it is slowly heated and completely burnt. After cooling

down it is weighed again and calculated as follows.

100c

ab)freemoisture(Ash = [%]

a = dish [g]

b = dish and ash [g]

c = coal (as weighed) [g]

Conversion of the ash content to the pit coal:

100

contentWater100)freemoisture(Ash)raw(Ash

= [%]

9.5 Volati le elements

Volatile elements are decomposition products of the organic fuel substance which leak out

as gases or vapours during the airtight heating of solid fuels up to around 900C. The

remaining residue is called crucible coke.

According to their volatile elements, the coals are classified in grades.

To determine the volatile elements, 1.000g of analysis sample is degassed in a quartz

crucible covered with a loose cover at 900C for 6 to 7 minutes. The degassed elements are

calculated as volatile elements in the following manner:

100c

ba)freemoisture(componentsVolatile

= [%]


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a = quartz crucible and coal (moisture free) [g]

b = quartz crucible and residue [g]

c = coal as weighed (moisture free) [g]

9.6 Sulphur

Apart from waste material, the sulphur content in solid fuels ranges between 0.1% and 2 %.

Depending on the bond, a distinction is made between organic and mineral sulphur. The

absolute amount of sulphur content would not matter if the SO2 emissions were not ofsuch importance today.

Organic sulphur is contained in the organic substance of the coal, whereas the mineral

sulphur derives from the ballast. The sulphur determination is effected according to

DIN 51724. The fuel analysis always specifies the total sulphur content.

9.7 Mel ting behaviour

The melting behaviour of the ash is an important indicator for the assessment of theslagging behaviour of coal ashes. For the slagging of the heating surface, it is important to

know the softening temperature of the ashes for all coal boilers.

An important characteristic for melting boilers is the flow temperature. The analysis

described in the following is designed to offer a comparison between different ashes

concerning their melting behaviour.

A compact of fuel ashes is heated in a slightly reducing or oxidising atmosphere. The

deformations which occur at different temperatures are a characteristic for the melting

behaviour.

The most important deformations:

Softening point (first indications for a deformation)

Melting point (specimen is hemispherical)

Flow point (ash becomes liquid)


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The melting behaviour of the ash depends on its composition. Lime, iron oxide and

alkaline salts reduce the melting point. Alumina and silicic acid increase the melting point.

Typical characteristics of the melting behaviour:

Short slags (little temperature difference between melting and flow

temperature)

Long slags (big temperature difference between melting and flow

temperature)

9.8 Grindability

The grindability characterises the necessary energy input for grinding coal. A method

which is often used is the Hardgrove procedure. This method is based on the law as set up

by Rittinger according to which the effort necessary for grinding is proportional to the

newly created surface.

In this procedure developed in the USA, a coal sample with a set grain size (0.5 to 1.2 mm)

is ground in a determined time unit. The screening occurs with an R 0.075 screen and is

compared to a reference coal.

Particularly for dust firing, the grinding of coal is of importance. Coals with a longer

carbonisation time have a reduced content of volatile ingredients, and they are harder.

According to empirical assessments there is a connection between the volatile elements

and the grindability. A low index means higher effort for grinding than would be necessary

for coal with a higher Hardgrove index. The grindability also depends on the mineral

content (ash) and its composition.

9.9 Air flue gas

On the basis of a basic measurement, the efficiencies of the individual components and

eventually the overall efficiency of the plant are to be determined. This requires a whole

range of individual measurements. In some parts of the system continuous measurements

have to be carried out, while in other parts of the system all lines have to be measured at


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the same time. The combustion system, i.e. the individual burner pipes, is an example of

this.

At this point, reference is made neither to the measurement set up not to the

measurement itself; only the measuring points shall be mentioned.

The fo llowing components of the air / flue gas system have to be measured:

Life air fans,

Induced draft fans,

Fans of the flue gas desulphurisation (FGD fans),

Flue gas return fans,

Mill and exhaust vapour fans,

Fans for pneumatic conveyance, i.e. carrying air for coal dust, air-borne

coke, ashes, shot beading etc.

Air lock fans for Ljungstrm air preheaters,

Fans for cooling towers and air condensators,

Ventilation and deaeration fans,

Air wheels for cooling the winding of electric motors and generators.

To determine the individual efficiency, the following parameters have to be measured in

individual systems: electrical power, pressure, temperature, mass flow, differential

pressure and oxygen content (O 2). When the measuring data are determined, wear,

pollution and leakages have to be taken into account; at least they should be documented.

9.10 Dat a requi red

The data required for assessing the efficiency, output, capacity, steam temperature

control, exist gas and air entering temperatures, water /steam pressure drops, air / gas

pressure drops, air infiltration, fuel, air and gas flows are given in the following tables.


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Ta bl e 1: Parameters required for efficiency determination by energy balance method (Source

ASME PTC 4)

Parameter Typical

Influence [Note (1)]

Typical


DRY GAS LOSS

Fuel Analysis

% O 2 in Flue Gas

Flue Gas Temperature

PRI

PRI

PRI

PRI

M

M

M

UNBURNED CARBON

% Carbon in Residue

Residue Split

Sorbent Analysis

Sorbent Rate

Fuel Rate

% CO2 in Residue

SO2/O2 Flue Gas

SEC

PRI

PRI

PRI

PRI

PRI

PRI

PRI

M/E

M

C/M

M

M

C/M

M

M

WATER FROM H2 IN FUEL LOSS

Fuel Analysis


PRI

PRI

PRI

M

M

M

WATER FROM H2O IN FUEL LOSS

Fuel Analysis


PRI

PRI

PRI

M

M

M

MOISTURE IN AIR LOSS

Fuel Analysis

Flue Gas O2

Dry-Bulb Temperature

Wet-Bulb Temperature

Or Relative Humidity

Barometric Pressure


SEC

PRI

PRI

PRI

PRI

PRI

SEC

PRI

M/E

M

M

M

M

M

M

M

UNBURNED CARBON RESIDUE LOSS

Fuel Analysis

% Carbon in Residue

Residue SplitSorbent Analysis

Sorbent Rate

% CO2 in Residue

SO2/O2 in Flue Gas

PRI

PRI

PRI

PRIPRI

PRI

PRI

PRI

M

M

M

MM

C/M

M

M

UNBURNED H 2 IN RESIDUE LOSS

% H2 in residue

SEC

PRI

E

M

CO IN FLUE GAS LOSS

Items for excess air

CO in flue gas

SEC

PRI

PRI

M/E

M

M


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Parameter Typical


Typical


PULVERIZER REJECTS LOSS

Pulverizer Rejects Rate

Pulverizer Rejects Analysis

Pulverizer Outlet Temperature

Fuel Rate

Fuel Analysis

SEC

PRI

PRI

PRI

PRI

PRI

E

M/E

M/E

M

C/M

M

UNBURNED HYDROCARBONS IN FLUE

GAS LOSS

Hydrocarbons in Flue Gas

HHV of Reference Gas

SEC

PRI

PRI

E

M

M

Sensible heat of residue loss

Residue split

Temp of residue

PRI

PRI

PRI

M/E

M/C/E

M

Hot air quality control equipment loss

Flue gas temperature entering

Flue gas temperature leaving

%O2 in flue gas entering

%O2 in flue gas leaving

Wet gas weight entering

Wet gas weight leaving

PRI

PRI

PRI

PRI

PRI

PRI

PRI

M

M

M

M

M

C

C

Air inflation loss

Inflation airflow

Inflation air temperature

Exit gas temperature

SEC

PRI

PRI

PRI

M

M

M

M

Formation of NO x loss

NOx in flue gas

Wet gas weight

SEC

PRI

PRI

M/E

M/E

C

Radiation and convention l0ss

Stream generator surface area

Local ambient air temperature

Local surface temperature

Local surface air velocity

PRI

PRI

PRI

PRI

PRI

M/E

C

M/E

M/E

E

Additional moisture lossMass flow of moisture

Flue gas temperature

Feed water pressure

Feed water temperature

Fuel flow

SECPRI

PRI

SEC

PRI

PRI

M/EM/E

M

M

M

C/M

Calcination dehydration of sorbent loss

Sorbent analysis

Fuel rate

% carbon in residue

PRI

PRI

PRI

PRI

M

M

C/M

M


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Parameter Typical


Typical


% CO2 in residue

Residue split

SO2/O2 in flue gas

PRI

PRI

PRI

M

M/E

M

Water in sorbent loss

Sorbent analysis


SEC

PRI

PRI

M

M

M

Wet ash pit loss SEC E

Recycled streams loss

Recycled flow

Recycle temperature entering

Recycle temperature leaving

SEC

PRI

PRI

PRI

M

M/E

M

M

COOLING WATER LOSS

Cooling water Flow Rate

Temperature Water Entering

Temperature Water Leaving

Fuel Rate

SEC

PRI

PRI

PRI

PRI

M/E

M/E

M

M

C/M

Air preheat coil loss

(energy supplied from within boundary)

APC condensate flow rate

APCcondensate temperature

APC condensate pressure


Feed water pressure

SEC

PRI

PRI

PRI

PRI

SEC

M

M/C

M

M

M

M

Entering dry air credit

Entering air temperature

Excess air

Fuel analysis

Unburned carbon

Sulfur capture

PRI

PRI

PRI

PRI

SEC

PRI

M

M

M

M

M/E

M

Moisture in entering air credit

Moisture in air

Dry-bulb temperature

Wet- bulb temperature or relative humidityBarometric pressure

SEC

PRI

PRI

PRISEC

M/E

M/E

M

MM

Sensible heat in fuel credit

Fuel analysis

Fuel temperature entering

SEC

PRI

PRI

M

M

M/E

Sulfation credit

SO2/O2 in fuel gas

Fuel analysis

Sorbent rate

Fuel rate

PRI

PRI

PRI

PRI

PRI

M

M

M

M

C/M


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Output 1.1


Parameter Typical


Typical


% Carbon in residue

% CO2 in residue

PRI

PRI

M

M

Auxiliary equipment power credit

Steam driven equipment

Mass flow of steam

Entering steam pressure

Entering steam temperature

Exhaust pressure

Drive efficiency

Electrical driven equipmentFor large motors:

Watt- hour reading

Drive efficiency

For small motors:

Volts

Amps

SEC

PRI

PRI

PRI

PRI

PRI

PRI

PRI

SEC

SEC

M/C/E

M

M

M

M

E/M

M

E/M

M

M

Sensible heat in sorbet credit

Sorbent rate

Sorbent temperature

SEC

PRI

PRI

M

M

M

Energy supplied by additional moisture credit

Mass flow rate

Entering temperature

Entering pressure

SEC

PRI

PRI

PRI

M/E

M

M

M

NOTES:

(1) Typical influence: PRI = Primary, SEC = Secondary

(2) Typical Source: M = Measured, C= Calculated, E = Estimated.

Tab le 2: Parameters required for efficiency determination by input-output method

Parameter Typical


Typical

Influence [Note (2)]Heat input from fuel

Fuel rate

Heating value of fuel

Fuel analysis

PRI

PRI

PRI

PRI

M

M

M

M

OUTPUT PRI M


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Parameter Typical


Typical

Influence[Note (2)

Auxiliary steam flow

Auxiliary steam temperature

Auxiliary steam pressure


Feed water pressure

PRI

PRI

PRI

PRI

SEC

M/E

M

M

M

M

Tab le 4: Parameters required for steam te mperature /control range determination

Parameter Typical Influence

[Note (1)]

Typical Influence[Note (2)]

Superheated steam generators

Main steam flow

Blowdown flow

Extraction flow

Main steam temperature

Main steam pressure

Drum pressure (if applicable)

Drum level


Feedwater pressureDesuperheated spray water flow

Desuperheated spray water temperature

Desuperheated spray water pressure

Other items required to determine output

Reheat steam generators

Reheat steam flow

Reheat out steam temperature

Reheat out steam pressure

Reheat in steam temperature

Reheat out steam pressure

Reheat desuperheating spray water flow

Reheat desperheating spray water temperatureReheat desuperheating spray water pressure

Related parameters

Excess air

Gas proportioning damper

Flue gas recirculation flowBlowdown

PRI

PRI

PRI

PRI

PRI

PRI

PRI

SECPRI

PRI

SEC

SEC

PRI

PRI

PRI

PRI

PRI

PRI

PRISEC

M

M/E

M

M

M

M

M

MM

M

M

M/C/E

M

M

M

M

M

M

MM

M

M

M


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Tab le 5: Parameters required for excess air determination

Parameter Typical


Typical


Excess air

Fuel analysis PRI

M

M

Unburned carbon

% carbon in residue

Residue split

% O2 in flue gas

PRI

PRI

PRI

PRI

C/E

M

M/E

M

O2 wet basis moisture in air

Dry-bulb temperature

Wet-bulb temperature

Or relative humidity

Barometric pressure

Additional moisture

PRI

PRI

PRI

PRI

SEC

PRI

C/E

M

M

M

M

M

Sorbent analysis

Ca/s molar ratio

Sorbent rate

Fuel rate

PRI

PRI

PRI

PRI

M

C/E

M

C/M

Calcination

% CO2 in Residue

PRI

PRI

C/E

M

Sulphur capture

SO2/O2 in flue gas

PRI

PRI

C/E

M

Tab le 6: Parameters required for water / steam pressure drop determination

Parameter Typical


Typical


Super heater pressure drop

Superheater outlet pressure

Superheater inlet (drum) pressure

Main steam flow

Feedwater flow

Blowdown flow

Extraction flow

Superheater spray flow

Superheater outlet steam temperatures

Superheater inlet steam temperature

PRI

PRI

PRI

PRI

SEC

PRI

PRI

SEC

SEC

M/C

M

M

M

M

M/E

M

C/M

M

M

Reheater pressure drop

Reheater inlet steam pressure

Reheater outlet steam pressure

Reheater flow

PRI

PRI

PRI

M/C

M

M

C/M


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Output 1.1


Parameter Typical


Typical


Feedwater heater extraction flow

Turbine leakage

Steam extraction flow

Reheater spray water flow

Reheater inlet steam temperature

Reheater outlet steam temperature

PRI

SEC

PRI

PRI

SEC

SEC

C/M

E

M

M

M

M

Economizer pressure drop

Economizer water inlet pressure

Economizer water outlet (drum) pressure

Feedwater flowSuperheated spray water flow

Economizer water inlet temperature

Economizer water outlet temperature

PRI

PRI

PRIPRI

SEC

SEC

M/C

M

M

MM/C

M

M

Tab le 7: Parameters required for air / flue gas pressure drop determination

Parameter Typical


Typical


AIR SIDE RESISTANCE

Forced draft fan discharge pressureAir heater inlet pressure

Air heater outlet pressure

Winbox pressure

Furnance pressure

Air flow

Main steam flow

Air temperature

PRIPRI

PRI

PRI

PRI

PRI

SEC

SEC

M/C

MM

M

M

M

C

M

M

GAS SIDE RESISTANCE

Furnance pressure

Super heater inlet pressure

Superheater outlet pressure

Reheater inlet pressure

Reheater outlet pressure

Generating bank inlet pressure

Generating bank outlet pressure

Economizer inlet pressure

Economizer outlet pressure

Air quality control equipment inlet pressure

Air quality control equipment outlet pressure

Air heater gas inlet pressure

Air heater gas outlet pressure

PRI

PRI

PRI

PRI

PRI

PRI

PRI

PRI

PRI

PRI

PRI

PRI

PRI

M/C

M

M

M

M

M

M

M

M

M

M

M

M

M


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Output 1.1


Parameter Typical


Typical


Flue gas flow rate

Main steam flow


PRI

SEC

SEC

C

M

M

Tab le 8: Parameters required for air infiltration determination

Parameter Typical


Typical


Infiltration based on measured o2

Excess air entering component

Flue gas O2 entering component

Excess air leaving component

Flue gas O2 leaving component

Infiltration by energy balance

Flue gas rate entering air heater

Flue gas O2 entering air heater

Fuel analysis

Flue gas temperature entering air heater

Flue gas temperature leaving air heater

Air temperature entering air heaterAir temperature leaving air heater

Moisture in air

PRI

PRI

PRI

PRI

PRI

PRI

SEC

PRI

PRI

PRIPRI

SEC

C

M

C

M

C

C

M

M

M

M

MM

M/E

Tab le 9: Parameters required for fuel, air and flue gas flow determination

Parameter Typical Influence [Note (1)] Typical Influence Note (2)]

Input from fuel

Fuel rate (measured)

Fuel rat (calculated)

Output

Fuel efficiency

Fuel analysis

PRI

PRI

PRI

PRI

PRI

M

C

M

C

M

Wet air flow rate

Excess air

Moisture in air

PRI

PRI

C

C

C

Wet gas flow rate

Fuel analysis

Unburned carbon

% carbon in residue

PRI

PRI

PRI

C

M

M/E

M


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Output 1.1


Parameter Typical Influence [Note (1)] Typical Influence Note (2)]

Residue split

Excess air

Moisture in air

Additional moisture

PRI

PRI

PRI

PRI

M/E

M/E

M/E

M/E

Sorbent analysis

Ca/S MOLAR RATIO

CALCINATION

Sulpher capture

PRI

PRI

PRI

PRI

M

M/E

M/E

M/E

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