Training Manual for SWSS[1].pdf

8/22/2019 Training Manual for SWSS[1].pdf

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TRAINING MANUAL FOR

STEAM AND WATER SAMPLING SYSTEM

EROOM TECHNOLOGY CO., LTD.


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TRAINING MANUAL FOR SWSS FOR HRSG UNIT

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CONTENTS

1. SWSS General

2. Basic Cycle Chemistry of Drum-type Units

2.1 Steam Generator (Boiler) Conditioning

2.2 Feedwater Cycle Condit ioning

3. Sample Points and Analysis Selection

3.1 Feedwater Pump Inlet (Sample #1, 8)

3.2 LP Drum Water (Sample #2, 9)

3.3 LP Superheated Steam (Sample #3, 10)

3.4 LP Saturated Steam (Sample #4,11)

3.5 HP Drum Water (Sample #5, 12)

3.6 HP Saturated Steam (Sample #6, 13)

3.7 HP Superheated Steam (Sample #7, 14)

3.8 Condensate extraction pump discharge (Sample #15)

3.9 Condensate pol isher outlet (Sample #16)

3.10 Aux. cooling water (Sample #17)

4. Sample Obtaining and Transport

4.1 Sample Obtaining

4.2 Sample Transport


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5. Sample Condit ioning

5.1 Pressure control

5.2 Flow control

5.3 Temperature control

5.4 Other sampling system components

5.5 Instrumentation and control

6. Sample Analysis

6.1 Precautions for grab sampling

6.2 Precautions for on-line analysis

6.3 Analysis definition, methods and applications

7. References


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1 SWSS General

1.1 Purpose of SWSS

To transport and condition samples without altering the constituents in the

samples.

To provide information on cycle chemistry to help assure the performance

determination of significant components and of the steam cycle in general.

1.2 Parameters to be controlled : Velocity (flow), temperature and pressure

1.3 Components constituting Sampling System :

pipes (tubes), Primary and secondary coolers, pressure reducing valves,

pressure and flow regulators, isolation valves, blowdown valves, resin

columns, control systems, analyzers and instruments.


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2 Basic Cycle Chemistry of Drum-type Units

2.1 Steam Generator (Boiler) Conditioning

2.1.1 Problems that could be caused by inappropriate steam generator

chemistry

(1) Deposition of solids on inside boiler tube walls.

- Corrosion products from condensate and feedwater systems,

and hardness constituents (Ca and Mg) in boiler water.

- form scales on high heat flux area of S/G

- reduces heat transfer and results in overheating and failure of

tubes.

(2) Corrosion of S/G material which causes

- material loss

- heat transfer resistance by resultant oxides resulting in tube

failure due to overheating and caustic attack

(3) Contamination of steam entering turbine beyond the steam purity

requirements of the turbine

- Steam could be contaminated by mechanical and vaporous

carryover of boiler water.

- mechanical carryover ; drum water entrainment in steam

- Vaporous carryover ; volatilization of impurities in drum water.

Silica presents most difficult problem due to its high solubility in

steam at intermediate S/G pressure.


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- Steam quality requirement for typical HRSG plant during

normal and constant operation

Parameter Target value Units

Cation conductivity < 0.2 /

Sodium, Na < 10 /

Silica, SiO2 < 20 /

Total Iron (Fe) < 20 /

Total Copper(Cu) < 3 /

2.1.2 Methods to minimize the problems

(1) Blowdown of S/G ; by continuously blowing down a portion of drum

water (less than 1% of feedwater flow rate) the impurities

concentrated in drum water can be removed.

(2) Corrosion within S/G can be minimized by maintaining pH of S/G

water at 9.0 or above, depending on the operating pressure. In

general, sodium phosphate (Na3PO4) is injected to drum water to

obtain desired pH level.

2.2 Feedwater Cycle Conditioning

Cycle conditioning is performed to minimize corrosion and subsequent

transport of corrosion products to downstream and to the S/G.

2.2.1 Conventional Treatment

(1) Elevates cycle pH in reducing environment by removing oxygen


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from feedwater at condenser and deaerator or by adding reducing

agent (Oxygen scavenger, N2H4).

(2) Reducing environment forms protective layer of magnetite (Fe3O4)

over steel material.

(3) To minimize the solubility of magnetite, pH should be kept around

9.5.

(4) If copper is present in cycle material, the copper solubility also has

to be minimized, which could be obtained at pH value of around 8.5.

(5) Compromised pH value of around 9.0 is used in case copper is

present in cycle.

(6) Ammonia typically is used as pH control agent.

2.2.2 Oxygenate Treatment (OT)

(1) Mostly for all-steel cycle of once-through boiler, oxygen or other

oxidizer is fed to the cycle to make oxidizing environment in the

feedwater.

(2) In the oxidizing environment, protective corrosion layer of ferric

hydrate oxide is formed over base layer of magnetite, with the

solubility of the former much lower than the latter, thus reducing

corrosion.


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3 Sample Points and Analysis Selection

Sample points and the analyses of each sample are selected based on the

criteria that they should give data for the decision whether steam and water

quality requirements of the cycle are met and the performances of important

equipment in the cycle are satisfactory.

In addition to the on-line analyses of each sample as selected, grab sampling

facility is furnished to enable further diversified analysis at laboratory environment.

In the following sections, each sample is discussed for the necessity of its

selection and types of analysis for a typical HRSG Cycle as shown in Fig.3.1.

3.1 Feedwater Pump Inlet (Sample #1, 8)

3.1.1 Purpose of analysis

To monitor the performance of deaerator

To check the effectiveness of oxygen scavenging and use the data

for dissolved oxygen control.

To determine compliance with the steam generator feeedwater

purity requirements.

3.1.2 Types of on-line Analysis and measuring ranges

Dissolved oxygen, 0~200 ppb


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Chem.

dosing

#1,8

Chem.dosing

Chem.

dosing

#6,1

3

#7,1

4

Chem.

dosing

#5,1

2

#2,9

#4,1

1

#3,1

0

Note:Thesecondsa

mplenumberinasetof

two

numbers

(#7,1

4forex.)

isfor

HRSG#2

#16

#15

Fig. 3. 1 Simplified d iagram of typical HRSG cycle


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Cation conductivity, 0~2 /

pH, 0~14 pH

3.2 LP Drum Water (Sample #2, 9)


To monitor the purity of boiler water which is critical for the

performance and operational lifetime of boiler unit

To use the analysis results as the basis for blowdown control

3.2.2 Type of on-line analysis and measuring ranges

pH, 0~14 pH

Specific conductivity, 0~100 /

3.3 LP Superheated Steam (Sample #3, 10)


To determine compliance with the turbine steam purity requirements

3.3.2 Type of on-line analysis and measuring ranges

pH, 0~14 pH


3.4 LP Saturated Steam (Sample #4,11)


To determine the quantity of moisture and chemical carryover from


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the boiler

3.4.2 Type of on-line analysis and measuring range


3.5 HP Drum Water (Sample #5, 12)


To monitor the purity of boiler water which is critical for the

performance and operational lifetime of boiler unit

To use the analysis results as the basis for blowdown control and

Na3PO4 dosing

3.5.2 Types of on-line analysis and measuring ranges

pH, 0~14 pH


3.6 HP Saturated Steam (Sample #6, 13)


To determine the quantity of moisture and chemical carryover from

the boiler

3.6.2 Types of on-line analysis and measuring range


3.7 HP Superheated Steam (Sample #7, 14)


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To check for the contamination of superheated steam due to

attemperation water impurities.

To determine compliance with the turbine steam purity requirements


pH, 0~14 pH


3.8 Condensate extraction pump discharge (Sample #15)


To monitor for in-leakage of cooling water in condenser

To monitor for air in-leakage in condensate extraction pump

To check for proper functioning of air ejectors


pH, 0~14 pH



Sodium, 0~50 ppb

3.9 Condensate polisher outlet (Sample #16)


To check for proper function of condensate polisher

To obtain base data for determining the performance of deaerator


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pH, 0~14 pH




3.10 Aux. cooling water (Sample #17)


To monitor for contamination of auxiliary cooling water of the plant.

Therefore, the sample is not taken from feedwater cycle but from

the cooling water supply line being introduced to Steam and Water

Sampling System.


pH, 0~14 pH



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4 Sample Obtaining and Transport

The most important criteria in deciding methods of obtaining and transporting

samples are whether they guarantee truly representative samples of fluids at

their respective sampling points.

4.1 Sample Obtaining

4.1.1 Water sampling

(1) Sampling nozzles

See Fig. 4. 1 for typical nozzle for water sampling

Sample taking from vertical pipe is preferable to avoid settling

resulting from low velocity

In case the water sample has to be taken from horizontal pipe,

the nozzle should not be installed on the bottom of the pipe.

(3) Location of sampling nozzle : on long vertical pipes to avoid

stratification of suspended solids and ensure that all water droplets

are carried in the flow stream.

(4) Nozzle insertion length : For single port nozzle, assuming fully

developed turbulent flow, the nozzle is normally inserted 0.2R of

the pipe from pipe inner surface, since this is the location where

actual and average velocities are equal.


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Multi-point nozzle can be used at locations where the velocity

profile across the pipe is known.

(5) Port size : is determined to maintain isokinetic sampling in the

nozzle port(s) at the desired sampling rate and design flow. But

port diameter should be larger than 1/8 inch to prevent plugging.

(6) Structure and material of nozzle: should be designed strong

enough to prevent failure due to vibration, thermal stress cycling

and other possible causes.

Nozzles normally are made of 316 stainless steel or other

austenitic stainless steel or alloy 600.

4.1.3 Superheated steam sampling

(1) Since superheated steam is usually regarded as single phase fluid,

isokinetic sampling requirement may not apply. However, the same

nozzle described for use with saturated steam can be used.

(2) High-pressure superheated steam can dissolve most contaminants

which, as steam pressure and temperature are reduced at nozzle

and sample line, can deposit on the surfaces causing biased

analytical results.

4.2 Sample Transport

Sample can be affected in many ways when they are transported from

nozzles to sample conditioning system.

Physical phenomena such as deposition and erosion, thermodynamic


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changes such as throttling and heat loss, and chemical and physical

changes such as reactions of oxygen scavengers, crystallization and

sorption are major causes that change the sample constituents.

Design of sample transport system should be focused on the ways to

minimize these changes and keep the samples unaffected as possible

during the transport.

4.2.1 Sample line construction

(1) Valves : Root valves should be installed at sample source. For high

pressure samples, double valves may be required depending on

safety considerations.

Valve and bore diameter should be selected so that velocity of

sample through the valve does not change much. Stainless steel

316 is preferred material for wet part of the valve.

(2) Sample line material selection; Wall thickness and material of the

tubes should be suitable for the temperature and pressure of the

sample source and should be of corrosion-resistant material. 316

Stainless Steel is preferred.

Tube inside diameter should be selected based on considerations

of sample velocity and pressure drop as discussed in section 4.3.

Fitting also should be selected based on their temperature and

pressure rating and made of materials compatible with the sample.

(3) Installation : Sample lines should be free of dead legs, particulate

traps(such as strainers), and low velocity zones. They should be as


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short as practical.

Adequate support to prevent fatigue failure from vibration should be

provided but free expansion and contraction with temperature

change should be allowed.

Sample lines normally should not be insulated.

(4) Fabrication : Weldings on the sample tubes on small diameter tube

(up to 3/8 inch) should be avoided as possible.

Tube bends are recommended instead of right angle fitting.

Burrs that could be produced after use of hacksaws and tube

cutters should be blown out with clean, oil free air or flushed prior

to installation.

4.2.2 Deposition

Results from chemical analysis can be biased either by the loss of

contaminants to the deposit on the tube wall or the gain of

contaminants from the deposits.

Mechanisms of deposition of contaminants are,

(1) Settling of particles: particles in the sample can stick to the wall

crossing the boundary layer by inertia, diffusion or gravity. Particles

so deposited can be eroded later by fluid drag force becoming re-

entrained in the fluid stream.

Steady state deposit weights are at the minimum when liquid

velocity is at 1.5 to 2.1 m/s. Minimum deposits is desirable because

of their shorter period of time for equilibrium and less susceptibility

to particulate bursts.


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All colloidal materials such as ion oxides and effluents from

demineralizers tends to form deposits also.

(2) Sorption of dissolved species: Deposits on tube walls are porous

and tend to sorb dissolved species by ion exchange, absorption,

adsorption or other mechanism.

(3) Crystallization: Most contaminants can be dissolved in superheated

steam. As the pressure and temperature of steam decrease, the

solubility of many contaminants is decreased and the contaminants

crystallize and deposit on the surfaces of dry wall tubes.

4.2.3 Saturated steam

(1) Typical behavior of saturated steam during transport.

Phase changes from saturated steam to two phase liquid of

vapor and liquid then to liquid as the sample temperature

decreases.

Sample velocity decrease from high speed of steam to lower

speed of liquid. As the desirable velocity of sample in the tube is

1.5 to 2.1m/s, which could be attained only in case of liquid

(condensate), the length of steam portion in the transport tube

should be short as possible.

When the steam velocity entering sample line is high, it will

cause pressure drop, increase the volume then further decrease

the pressure. In case of combined cycle plants, where steam of

pressure less than 35/ are produced, this pressure drop

temporarily causes the steam to enter the superheat region. The


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phase changes, from saturated steam to superheat steam then

to liquid water will result in abrupt flow speed changes, which

gives harmful effect to obtaining representative sample.

(2) Sample flow rate should be maintained constant as possible to

avoid condensing length changes, regional changes of phase and

resulting flow.

(3) Steam sample line sizing : For deciding sample line size and length,

calculations to determine heat loss and pressure drop for different

flow condition is required. Table 4.1 summarizes the calculations

for typical tube sizes at different pressure and flow condition. In the

table, following abbreviations are used.

Max. L : Maximum recommend length. N.R. indicates not

recommended for any length due to excessive

pressure drop.

Cond. L : Length where all steam is condensed. indicates that

the steam is not condensed within recommended length.

SteamVmax : Maximum velocity of steam at recommended length.

A bullet() indicates that the steam velocity is

increasing due to expansion. Where tube size is not

recommended for any length, required steam

velocity is given.

Cond. Vmin : Velocity of condensate at 500ft(154m). indicates

that the steam is not fully condensed in the

recommended length or within 500ft(154m).

*

*


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Table 4.1

Recommended Sample Tube Sizes


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The calculations for Table 4.1 are based upon straight tubing. In

case unusual number of bends is used in the sample transport line,

allowance for additional pressure drop has to be made.

4.2.4 Superheated steam

(1) To minimize deposit and loss of contaminants on the dry wall

portion of sample line where the temperature is higher than the

saturation temperature of the steam, it is recommended that

superheat be removed from steam sample as early as possible.

Where applicable, source cooling is recommended for this purpose.

(2) Once the sample lose all its superheat, it will behave in the same

manner as saturated steam. Table 4.1 includes recommendations

for superheated steam also.

4.2.5 Liquid samples

Liquid sample lines should be sizes for sample speed of 1.5 to 2.1 m/s.

This velocity range will result in minimum equilibrium deposit weight

reached in the minimum operation period of about 30 days.


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5 Sample Condit ioning

The objective of steam and water sample conditioning system is to modify and

control the temperature, pressure and flow rate of the samples from the sample

sources so that they are safe for grab sampling or are compatible with the

requirements of on-line analytical instruments.

5.1 Pressure control

Pressure control of a sample is performed by incorporating two control

methods, pressure reduction and back pressure control. Final target of

these controls is to establish a constant pressure zone so that analyzers

being fed from this zone get constant flows independent of actions taken in

other branch lines, while maintaining constant flow in the main sample line.

Normally, the pressure at the constant pressure zone is controlled at

0.5~1.5/.

5.1.1 Pressure reducer

(1) Pressure reducer is located down stream of primary sample cooler

so that the liquid is sub-cooled before pressure reduction.

(2) For samples greater than 35/, variable rod-in-tube type orifices

are recommended for they

provide varying pressure drop

are cleanable in place


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Fig. 5. 1 Typical arrangement of a sample conditioning system for a high-pressure

high-temperature sample.


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eliminate possible sample bias due to dissociation of water into

hydrogen and oxygen that can occur across throttling valves

when sampling at high pressures.

(3) For Samples less than 35/, needle valve is recommended for

pressure reduction.

5.1.2 Back pressure regulators.

(1) By maintaining upstream pressure at constant value (0.5~1.5/),

back pressure regulator performs two important functions, feeding

constant flows and pressure to analyzers and maintaining fixed

total sample flow.

(2) Back pressure regulator continuously discharges the flow

difference between total main sample flow and the sum of flows to

analyzers.

(3) Fore pressure regulator cannot provide constant sample line flow.

5.2 Flow control

Flow control is attained by adjusting flow meter control valve for each

analyzer in conjunction with pressure control of section 5. 1.

5.2.1 Total flow rate through a sample line is basically decided considering

optimum velocity requirement in the sample transport line

(1.5~2.1m/sec for water).

However, other factors such as pressure drop along the transport line,

total transport time etc. also have to be taken into account and


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compromise has to be made when required.

5.2.2 The total flow is obtained by adjusting the pressure reducer in flowing

condition.

Downstream pressure of the reducer is controlled by back pressure

regulator at 0.5~1.5/ as described in 5. 1. 2.

5.2.3 Once the pressure is established at constant pressure zone, flow to

each analyzer should be set at rate required by the analyzer by

adjusting control valve that is normally an integral part of flow meter.

5.2.4 Flow meters

(1) Flow meters for total flow and flow to each analyzer are

required.

(2) Flow meter for analyzer has manual flow adjust valve as an

integral part of the meter.

(3) Flow meters are normally rotameter types with visible indicator

(4) The rotameter shall be made of materials that are corrosion

resistant and not reactive with samples.

5.3 Temperature control

Temperature of all sample is reduced and controlled at 25 because most

on-line analyzers require samples to be standard temperature to ensure

repeatable and accurate results.

5.3.1 Primary cooler

Primary cooler is used to reduce the sample temperature to less than

2.8 of cooling water inlet temperature for water sample and 5.6


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of the cooling water inlet temperature for steam sample at

representative sample flow.

In general, for sample temperature greater than 80, primary cooler

can be used. But the decision should be based on the capability of

secondary cooler and chiller unit.

5.3.2 Secondary cooler

Secondary cooler should be capable of 0.5 approach to the chilled

water temperature.

5.3.3 Material and construction

Cooler are normally tube coils in a shell type. Cooler tube and shell

shall be made of stainless steel, preferably SS316 for tubes. For high

chlorides in the cooling water, however, Alloy 600 is recommended.

5.4 Other sampling system components

5.4.1 Blowdown valve

(1) Blowdown valves are used to purge sample lines that are not in

continuous service or where suspended solids deposition

affects the sample.

(2) The blowdown valves can be located either prior to primary

cooler or downstream of pressure reducer or at both.

(3) Blowdown valve prior to primary cooler may be operated on

initial startup of the system or after long period of shutdown of

the system to remove any foreign materials and deposits in the


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sample transport line.

(4) Blowdown valve downstream of pressure reducer is operated

every time before the sample line is put into operation to flush

the cooler and reducer in addition to sample transport line.

(5) Regulating type valve is used for blowdown valve prior to

primary cooler and ball valve for down stream of reducer.

5.4.2 Isolation valves.

For sample pressure higher than 48/ double isolation valves are

recommended.

Regulating type or ball valve rated for sample pressure and

temperature are used.

5.4.3 Sample relief valve

Each sample line should be provided with a pressure relieving device

to protect components from over-pressurization. Spring-loaded type

back pressure relief valve is commonly used located downstream of

pressure reducer.

5.4.4 Cooling water valves on sample coolers.

Each sample cooler should have an inlet isolation valve and outlet

throttling valve. Cooling water flow is adjusted by the outlet valve to

give optimum cooling water flow to the cooler and make balance

between cooling waters to different coolers from same cooling water

source.

5.4.5 Fitting

It is preferable to use bends rather than fittings to change direction of

sample tubing.


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Compression or socket weld fitting should be selected based on

application but compression fittings are preferable.

5.4.6 Sample filters may be installed in the line to trap particles and reduce

plugging on downstream components. But filters can affect sample

analytical results and are not recommended normally.

Filters made of stainless steel 316 with mesh size of about 100 is safe

enough if filters are to be used.

5.5 Instrumentation and control

5.5.1 In addition to monitoring flows by rotameters, pressures and

temperatures of final samples are monitored either by local indicators

or indications on control panel.

5.5.2 To protect components and analyzer sensors from abnormal high

temperatures due to failures on coolers, temperature switches may be

installed on final sample line which will trigger alarms and/or divert

sample flows to blowdown valves.

5.5.3 Control of sample and blowdown valves.

Control of sample valves and blowdown valves can be performed

either local-manually, remote-manually or remote automatically.

(1) Local manual method : Opening and closing of valves are done

at the valve locations by hand.

(2) Remote manual method : Pneumatic on-off valves are used

enabling manual operation of the valve from control panel.

(3) Automatic operation of valves: In automatic operation,


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blowndown and sample valves are operated in automatic

sequence with the blowndown duration is preset as required.

The automatic operation of sample lines can be performed

individually or in groups.

(4) Remote operation of valves can be initiated from control panel

of the sample conditioning system or from the main control

system (DCS) of the plant.

(5) PLC system is commonly used to realize remote and automatic

operation in sample conditioning system.


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6 Sample Analysis

Sample transported to and conditioned at sample conditioning system are either

grab sampled and analyzed at plant chemical laboratory or analyzed on-line by

analyzers on the sampling system control panel.

6.1 Precautions for grab sampling

(1) Samples should be taken from continuously flowing stream, not from

any dead leg in the sample conditioning system.

(2) If sample has not been flowing prior to grab sampling, blowdown of the

sample line has to be performed for enough time to flush and stabilize

the line.

Blowdown time to flush six times the total line volume is acceptable. But

when the system is being started initially or when new tubes or sample

coolers are installed, much longer period of time for flushing (preferably

several weeks) by continuous flow is required.

(3) The sample velocity in transport line during flushing and sample taking

should be maintained at 1.5~2.1 m/sec.

6.2 Precautions for on-line analysis

(1) Proper sample conditioning, particularly constant flow and temperature

has to be maintained.

(2) Manufactures requirements for sensor operation, flow rate range,

maximum pressure etc. have to be met.


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(3) Regular calibration of analyzers according to manufactures instructions

has to be performed.

(4) When the sensors, especially pH and Dissolved Oxygen, are out of

service or when the sample lines have to be left dry, special cares have

to be taken to avoid critical damages to the sensors. Instructions of

manufacturers manual has to be followed.

6.3 Analysis definition, methods and applications

In this section, brief explanations on the definitions, methods and

applications for the analyses being made in NEKA plant are given. Detailed

information on each analysis will be presented in separate class for each

analyzer.

6.3.1 Specific Conductivity

(1) A measurement of all ionic species which contributes to the electric

conductivity of a solution.

(2) Unit in normal use is micro Siemens per centimeter(/), which is

the reciprocal of the resistance in ohms measured between opposite

faces of a cubic centimeter of an aqueous solution referenced to

25.

(3) High-purity conductivity analyzer should adopt specialized

algorithms to account for the dramatic change in ionization of water

with temperature. The unique effects of ammonia, morpholine, etc.

present in the sample also has to be compensated for.

(4) Keeping the sample temperature at reference temperature of 25


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is very important for accurate measurement of conductivity because

the temperature compensation algorithm cannot count for all the

effect of varying constituents in the water and the temperature

sensor itself could produce erroneous signal.

(5) Specific conductivity tends to follow the concentration of pH

adjusting agents(usually ammonia).

(6) Electrical conductivity methods are widely used for monitoring

makeup water, feedwater and condenser leakage for its

comparatively little maintenance required, low cost and high

reliability.

6.3.2 Cation conductivity

(1) A measurement of anionic contamination rather than total ionic

species. Sample is passed through a hydrogen ion exchange

resin before conductivity measurement, where ammonia, amines

and other cationic contaminants are removed.

(2) Removing cation ions will greatly sharpen sensitivity to

contamination by removing the masking affects of ammonia,

amine and convert salts to the corresponding mineral acids,

which are a more conductive than the salts, thus further

increasing sensitivity.

(3) Non-ionized or weakly ionized substances (for ex. SiO2) and

hydroxide ions are not measured by this method.

(4) Is useful for detecting the leakage of cooling water into

condensate.

6.3.3 Dissolved oxygen


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(1) Oxygen dissolved/entrained in aqueous media.

(2) Measured by electrochemical method. Unit is in /L (ppb).

(3) Dissolved oxygen measurements is used to detect oxygen inleakage

at condensate pump discharge and also to monitor deaerator

performance and results of oxygen scavenger (N2H4) injection.

6.3.4 pH

(1) The negative logarithm of concentration or activity of hydrogen

ion (-log[H+]).

(2) Measured by electrometric instrumental probe method.

(3) pH measurements are made on most of the samples to monitor

whether the required pH level for minimizing corrosion of

steam/water cycle materials are maintained. The measurements

also provide data for the decision of pH control agent injection.

6.3.5 Sodium

(1) Alkali metal present in water as cation Na+.

(2) Measured by ion-selective electrode method. Unit is in

/L(ppb).

(3) Sodium measurement is made on samples from condenser

extraction pump discharge to detect condenser in-leakage and

breakthrough from condenser polisher dimineralizer.


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7 References

(1) Power Plant Engineering, by Chapman & Hall, 1966

(2) Steam and Water Sampling, Conditioning and Analysis in the Power Cycle,

ASME PTC 19.11-1997

(3) Standard Guide for Equipment for Sampling Water and Steam in Closed

Conduits, ASTM D1192-98

(4) Standard Practices for Sampling Water from Closed Conduits, ASTM D3370-

1999

(5) Standard practice for Sampling Steam, ASTM D1066-97

Documents

Training Manual for SWSS[1].pdf