3.OTHER SG/TG RELATED CONTROL & INSTRUMENTATION

3.00.00  OTHER SG/TG RELATED CONTROL & INSTRUMENTATION

        SYSTEM/ EQUIPMENTS

 

3.01.01  FLAME MONITORING SYSTEM

 

         The purpose of the system is :

 

     i)  To detect the  individual flame and to  enhance  the 

 

         boiler/furnace safety.

 

     ii) To avoid spurious and unwarranted trips.

 

    iii) To  increase operational reliability,  availability  and

 

         efficiency   of  the  steam  generator  such  that   the

 

         consumption  of  fuel oil shall be  reduced  to  optimal

 

         minimum.

 

3.01.02 a) Fail  Safe easily maintainable flame monitoring   System

 

         shall be provided which shall include flame detectors of

 

         proven  design  for  the  type  of  fuel,  environmental

 

         condition   and   other   conditions   of    established

 

         reliability  at  all loads of the steam  generator.   It

 

         shall  be designed to work under all adverse  conditions

 

         such  as wide variation in fuel/ air input  ratio,  wide

         

         variation   in   fuel  characteristics,   variation   in

 

         operating temperature, maximum temp.under  interruption

 

         of cooling air supply.

 

       b) The  system  shall conform to  NFPA  recommendation and

location of detectors as per NEC requirements. The detector (photo cell) shall be UV/IR type .Flame  detector shall be working on  the   dynamic  and static  properties  of primary combustion zone  of  each type  of fuel and flicker frequency of flame.  It  shall  pick up only the flame to which it is assigned and shall  not  respond  to the  adjacent and background  flame  or other  radiations generated in the furnace. The   design  shall  also take into account the absorption by  a  coal shroud,  recirculated  dust or other deposition  on  the

         flame detector head.

 

      c) The  complete system shall provide  the   discrimination

 

         between oil and coal flame intensity indicators for main

 

         flame  shall  be  provided.  Also  isolated  4-20  A  DC

 

         signals shall be provided and looked at DDCMIS.

 

3.01.03  The  system  should be easily maintainable  and  include

 

         automatic  self test facility at regular interval.   The

 

         Bidder  shall  also provide a  portable  flame  detector

 

         testing  kit  with  built  in  stabilizers,  capable   of

 

         simulating both oil and coal flame, and testing of flame

 

         detector head unit at field.  The testing kit shall have

 

         facility  for  testing all type of electronic  cards  as

 

         being used in the flame monitoring system.

 

3.01.04  In case of tangentially fired burner, the bidder   shall

 

         arrange  flame  detectors one in each corner in  such  a

 

         manner  that  coal flame detectors  are  available  both

 

         above and below  each of the coal elevation and separate

 

         oil  flame detectors, one at each corner, for each  oil

 

         elevation.   In case the Bidder provides  discriminating

 

         flame  detector capable to detect and discriminate  both

 

         oil  and coal flame, the same can also be  utilized  for 

 

         monitoring  both oil flame in respective elevations  and

 

         also the coal flame of adjacent coal elevation.  For any

 

         other  type  of  Boiler the  flame  detectors  shall  be 

 

         provided for each coal and oil burner responding only to

 

         the flame of its associated burner.

 

         Bidder  shall  also  furnish the details  of  the  flame

 

         detector locations and justification for the same.

 

3.01.05  Site Tests

 

       a)The Bidder shall demonstrate the complete performance of

 

         flame detectors in cold start up test and load condition

 

         test.

 

         In cold start up test, capability of detectors to detect

 

         oil flame under varying oil pressure shall be   checked. 

 

         In load test, the detector shall be able to detect  when

 

         only oil is present, only coal is present and both  coal

 

         and  oil  are  present.  It shall be  ensured  that  the 

 

         detectors  are able to detect the proven flame  at  very

 

         low load with oil GUNS Withdrawn.

 

         The  above tests shall be  performed for every coal  and

 

         oil elevation. Contractor shall submit test results for

 

         review & approval.

 

3.02.00  Provision  of  scanner air for cooling the  flame detectors

       

         by  100% redundant scanner  air fans, one  AC  and

 

         other DC operated, shall be provided.  The emergency and

 

         discharge dampers shall be  pneumatically operated  with

 

         DC solenoid valves. 

 

3.03.00 GRAVIMETRIC BELT TYPE COAL FEEDERS CONTROL AND INSTRUMENTATION

 

         Bidder shall provide a microprocessor based coal  feeder

 

         C&I (explosion proof, meeting NEMA requirements) system 

 

         having  the  following  feature. It is preferable to use

 

         the same family of hardware as that of CLCS for implemen-                 

        

         tation.

 

      1) Bidder shall provide a minimum of two independent  speed

 

         sensors, pulsar units and associated amplifiers, etc.for

 

         each  of  the  coal feeders.   Output  from  the  speed

 

         sensors will be used to provide at least four 4-20 mA DC

 

         analog  signals and any other signals required  for  the

 

         control of the coal feeder.

 

         In addition, one pulsar unit shall also be provided with

 

         two pulse outputs-one for use in Control system and  the

 

         other for remote integrator.

 

         Each  coal feeder shall receive signals from DDCMIS  for

 

         feeder  speed/mill  level  control.  The  signal  to  be

 

         provided by DDCMIS shall be in the form of  galvanically

 

         isolated  4-20  mA DC.  All  required   power  amplifier

 

         units/interface  devices to  accept this 4-20 mA  signal

 

         shall be  included.

 

     2)  All  associated  electronics  like  buffer   amplifiers,

 

         frequency  to current converter etc. shall  be  provided

 

         for   each  RC  feeder  with  local  and  remote   speed

 

         indicators  and  integrators.   The  speed  sensors  and

 

         pulsar  unit shall be totally enclosed, fire,  dust  and

 

         weather proof, suitable for the service conditions.  All

 

         the  necessary  paddle switches and other  detectors  to

 

         monitor coal on belt, feeder discharge plugged and other

 

         protection  and  interlocks for safe  operation  of  the 

 

         feeder is to be provided. 

  

    3)   The  control cabinet shall be provided  with  individual

 

         lights   to   signal  the   individual   internal   trip

 

         conditions. Necessary electronics/ push buttons shall be 

 

         provided  in the control cabinet for  resetting  feeders

 

         internal  trip.   In addition to  the   internal  trips,

 

         there  shall  be overload trip  associated  with  feeder

 

         motor  starter. Provision for resetting the  same  shall

 

         also be provided.  Each feeder shall be  provided with a

 

         four  position switch located at the feeder for  remote,

 

         off,  local run (when there is no coal  on  conveyor)and

 

         calibration purpose.

 

     4)  If there is any electronic modules mounted local to  the

 

         feeder  body then these shall be suitable for  operating

 

         in a non air-conditioned area.

 

     5)  Coal feeders shall compensate  for coal density and feeder volumetric efficiency effects by maintaining coal weight flow to coal burner to match air flow.

 

3.04.00  ELECTROMATIC  SAFETY  VALVES

 

         The  Electromatic  safety valve shall be  an  automatic,

 

         electrically  actuated pressure relief valve.  It  shall

 

         be possible to set the value for 1% or less differential

 

         between  opening and closing pressure. The  Electromatic

 

         safety  valve  shall  be  provided  complete  with   all

 

         accessories like pressure measuring devices,  controller

 

         units,   solenoid  assembly, impulse  piping  etc.    The

 

         Electromatic  safety  valves shall be  provided  with  a

 

         local controllers and a miniature remote control station

 

         suitable  for mounting on the UCP  along with  indicating

 

         lights  and  switches to facilitate  auto/remote  manual

 

         operation  of  the  valve.  The operation of  the  valve

 

         shall be accomplished by use of a switch or by means  of

 

         pressure  sensitive  element which shall  precisely  and

 

         automatically  relieve the pressures within  very  close

 

         limits.   Bidder shall furnish complete details of  the

 

         Electromatic  safety  valves  along with  its   technical

 

         catalogue, list of accessories etc. In his proposal  for

 

         MPPGCL’s approval.

 

3.05.00  FURNACE  TEMPERATURE PROBES

 

         Bidder  shall  provide  2  Knockoff  furnace   temp.probes

 

         before  platen  superheater  and/  or  before   reheater

 

         regions. These furnace temp.probes shall be electrically

 

         operated,   fully   retractable  type.    The   furnace

 

         temp.probes  shall be furnished with complete  actuating

 

         mechanism and all the logics required for the  actuating

 

         mechanism.   The probe shall be  provided with  position

 

         transmitters,  limit  switch  &  indicator  for   remote

 

         indication.    The  temp.probe  shall  have   a   duplex

 

         thermocouple suitable for the measurement range.  Bidder

 

         shall   furnish  complete  details  of  the   temp.probe

 

         alongwith  all  the technical catalogues  including  the

 

         details of the actuating mechanism, position transmitters

 

         and  limit  switch which shall be  subject  to  MPPGCL’s

 

         approval.    The  logic  for  the   furnace   temp.shall

 

         preferably be implemented in the DDCMIS.

 

3.06.00  BOILER FLAME ANALYSING SYSTEM

 

         To  assist in optimization of combustion  efficiency with

 

         variation  in  loads and fuel qualities,  betterment  in

 

         flame  stability  and  to  limit  Slagging  and  unburnt

 

         carbon,  NOx  level  to  an  acceptable  limit   through

 

         efficient  flame  monitoring, analysis  and  combustion

 

         management system.

 

         The  system shall consist of furnace flame  cameras(semi

 

         conductor  type, one per each coal burner), flame  image

 

         processors  &  a PC based management  system,  along with 

 

         all required accessories.  The system shall be   capable

 

         to provide information about (i)ignition point position

 

         on  fuel stream, (ii)height of fuel steam,  (iii)  upper

 

         and lower flash point in the combustion area covered  by

 

         the   corresponding  camera as a minimum.   Each  camera

 

         shall be able to view up to two and half meter or  better

 

         of the fuel flow  coming from the burner.

 

         The   flame  image  processor  shall  be  housed  in   a 

 

         standalone  cabinet to be located in  control  equipment

 

         room.   I  shall analyse the images received  from  each

 

         cameras and shall produce flame parameters every  second

 

         in order to provide continuous monitoring of  combustion

 

         as well as detection of alarm conditions.

 

         The  Pentium  PC based management system  along with  all

 

         required  software shall consist of 21″ TFT Monitor PC with 

 

         I/O cards,  associated keyboard etc. Display of live/frozen flame  of  the complete furnace as well  as  live/frozen flame of the selected camera shall be available. The configuration of PC shall be fault tolerant  and time synchronized from Master Clock.

 

         The system shall also provide information about  average

 

         intensity  of  the  flame, the total  intensity  of  the

 

         analysis area, stability of ignition etc.

 

         The  bidder shall provide all hardware and soft wares  as

 

         may be required to make the system complete.

 

         The system shall be of proven design and its performance

 

         must  be  proven for at least two 210 MW  rating  boilers

 

         using  similar type of fuel for a period of  two  years. 

 

         The  components to be located  at boiler area  shall  be 

 

         able to withstand the stringent environmental  condition

 

         expected  at  such  locations  with  operating   boiler.

 

         Adequate  cooling  arrangement for the cameras  and  the 

 

         components  to be located at the furnace area  along with

 

         automatic lenses cleaning facility shall be provided.

 

3.07.00  COAL BUNKER LEVEL MONITORING SYSTEM

 

         Complete Coal Bunker Level Monitoring System  consisting 

 

         of strain gauge sensors electronic units, bar graph  type

 

         displays mounted in Coal Handling Plant Control Room (to

 

         be    supplied    loose)any    necessary    intermediate

 

         electronics,   interconnecting  cables  etc.  The   No.&

 

         location  of the strain gauge sensors shall be  selected

 

         by the bidder to ensure that overall accuracy (including

 

         sensors  & electronic unit)of the system is +/-  10%  or

 

         better  in spite of possible interaction between support

 

         systems of adjacent bunkers.

 

         The  electronic  units  shall be mounted  in  a  cubicle

 

         located in CER. These shall provide two isolated 4-20 mA  DC

 

         output  for  the bargraph type displays as well  as  for

 

         DDCMIS.

 

3.08.00  WATER  LEVEL MONITORING SYSTEM

 

     a)  Electronic Remote Drum Level Monitoring System

 

         For  Boiler  drum  in order to measure  &  monitor  drum

 

         level, bidder shall provide Electronic Remote Drum Level

 

         Monitoring System working on principle of difference  in

 

         electrical  conductivity  between steam and  water.  The

 

         monitoring   system  shall  meet  the  requirements   as

 

         indicated below.

 

     (i) Each  end  of the drum shall have  independent  pressure

 

         vessels  with  16 No. of  electrodes  covering  the

 

         entire  range  for  indication for  each  end  of  drum.

    

         Bidder shall provide High  & Low and Trip contacts (Very

 

         High, Very Low) with validation and 4-20 mA signal for

 

         Drum level measurement.

    

    (ii) The  sensing electrodes shall be placed in equal  pitch. 

 

         The maximum distance(gap) between two electrodes shall be

 

         50 mm and the electrodes shall be arranged in such a way

 

         that  the last and the first electrode shall not be   at

 

         any  alarm  or  trip level.  In  any  case,  the   No.of

 

         electrodes shall not be less than 16 for indication. 

 

   (iii) The  system  shall  be proven and  approved  by  Factory

 

         mutual, USA of equivalent, IBR etc.

 

3.09.00  Conductivity Type Level Switching System

 

3.09.01  For Deaerator, Condenser  hotwell  and  HP &  LP

 

         heaters  alarms/protections,  level  switching   systems

 

         employing conductivity probes shall be provided. Each of

 

         the  switching systems shall be furnished complete  with

 

         at least  4 Nos. conductivity probes column for  mounting

 

         the conductivity probes, isolating valves, drain  valves

 

         vent  valves, electronic units, twisted & shielded  pair

       

         interconnecting  cables. The conductivity probes  &  the

 

         column  for mounting these probes shall be designed  for

 

         the respective pressure and temp.conditions.

 

         The  electrodes shall be designed in such a manner  that

 

         they  sense the rising water level and that they do  not

 

         give faulty indication due to falling condensate on  the

 

         electrodes.  Also, each system shall incorporate  proper

 

         validation circuits that eliminate spurious or  unwanted

 

         alarm/ trip actions due to a single channel fault.

 

   3.09.02  Bidder shall provide Conductivity type level switches in

        drain pots of  MS, HRH, CRH pipes etc. as per  ASME TDP-1.

3.10.00  TURBINE SUPERVISORY SYSTEM (TSS)

 

3.10 01  The  Turbine  supervisory equipment  shall  be  complete

 

         including sensors, transmitters, converters, limit value

 

         monitors,   measuring  and  amplifier   modules,   power

 

         supplies  etc.with  the required  accessories  including

 

         twisted    and    shielded    instrumentation    cables,

 

         compensating  cables,  junction  boxes  etc.   Following

 

         measurements shall be provided as minimum.

 

      i) Shaft Eccentricity Detection

 

     ii) Absolute   as   well   as   relative   shaft   vibration

 

         measurement,  of  each bearing in both X & Y  direction.

 

    iii) Differential  expansion of rotor  and cylinder for  HPT,

 

         IPT and LPT and LPT.

 

     iv) Over all expansion of HPT and IPT.

 

      v) Absolute  bearing vibration measurement of each  bearing

 

         in both X & Y directions.

 

     vi) Stator winding vibration vibration measurement in radial

 

         and tangential directions.

 

    vii) Axial shift of the rotor

   viii) Turbine Speed

     ix) Emergency stop and control valve position

      x) Main Steam and Hot Reheat Steam Inlet Temp. and Pressure

     xi) Bearing metal and drain oil Temp.

    xii) Turbine metal Temp.

 

   xiii) In case of vibration, shaft mounted reference  detectors

 

         and required supervisory instrument circuitry shall also

 

         be provided.

 

    xiv) Any   other  measurement  recommended  by  the   Turbine

 

         manufacturer  or  required  for the  safe  and  reliable

 

         operation.

 

         The system shall be provided with suitable hardware  for

 

         necessary  signal  processing.   The  system  should  be

 

         capable  of  signal distribution  and  interfacing  with

 

         other  Control  Systems.  The  system  should   suitably

 

         interface with MMIPIS system supplied by bidder.

 

3.10.02  For    all   vibration   measurements    indicated    in

 

         items(ii)and(v)v.z.absolute  bearing vibration  relative

 

         shaft   vibration  and  absolute  shaft   vibration   as

 

         indicated   under   Clause  3.9.01   above,   redundant

 

         microprocessor/fault tolerant computer based system and time synchronized from Master Clock shall  also  be

         provided to achieve the following functions :-

 

     (i) On line spectrum/harmonic analysis.

 

    (ii) Identification of the exact nature of failure  resulting

 

         in  increase in bearing vibration and direct message  on

 

         the   CRT   indicating  the  exact   nature   of   fault

 

         e.g.Misc.shaft crack bearing looseness etc.

 

   (iii) Storage and comparative analysis of vibrations.

 

    (iv) Generation/  analysis of Bode Plot/Orbit Plot  and  time

 

         waveform/   nyquist  plot/  shaft  center  like   plat/

 

         cascade and water fall plot.

 

         All  the  vibration  parameters  as  well  as    Turbine 

 

         supervisory  parameters  shall also be fed  to  the DCS

 

         through  hardwiring  so that all  these  parameters  are

 

         suitably displayed on the OWS. All required I/O cards and

 

         other processing  modules etc. shall be provided for this

 

         purpose.

 

3.10.03  Test  calibration  jigs  for  site  calibration  of  all

 

         sensors  of  TSS shall be   provided.   Telephone  jacks

 

         shall  be  incorporated  in all  the  TSS  cubicles  for

 

         communication during site calibration etc.

 

3.10.04  Environmental limits  for    Turbine Turbovisory

 

         instruments.

 

     a)  Operating  Temperature for sensor and  Extension cable.

 

         0 – 177 Deg.C

 

     b)  Relative Humidity  -  0- 95%

 

     c)  Corrosion Resistance

 

         Probe  Operation  shall not effected by  direct  contact

 

         with water or lub oil.

 

     d)  Sensor to Junction box  extension cable shall be   FRLS,

 

         screened, armoured, twisted, oil resistant.

 

     e)  The  system  shall be  designed  accordance  to

 

         recommendation of API-670.

 

3.11.00 The configuration of all PC shall be  fault tolerant and

 

         Time synchronized with master clock.