Wednesday, July 11, 2012

Offshore Telecommunication System

The telecommunication system of living quarter and production platform generally have the SCADA Radio System, CCTV System, IP Network and Phone System, FM/AM/CB/SSB Radio Systems, SAT Phone System, MET System, NDB System, and Entertainment System.

1. Meteorological (MET) System: it is the system that measured the weather and monitoring.


There are wind speed, temperature & humidity, rain fall and barometric sensors were installed at highest point of living quarter, but the location of installation must be avoid the effect of helicopter while landing. 




the measuring data is stored and sharing to MET system server, and the operator can be monitored in radio room.




cont...













Living Quarter ICSS

This ICSS of living quarter was design by using Honeywell PKS and ControlLogix. The PCS, SIS and FGS are PLC that was applied for utilities and office, the accommodation used own fire alarm system from Autronica.   

cont...

Saturday, July 7, 2012

Gas Turbine LM2500+ G4

There are five (5) types of shutdown sequences of GE Gas Turbines.

1. FSLO = Fast Stop Lockout with Motoring
2. FSWM = Fast Stop with Motoring
3. CDLO/NORMAL = Coldown Lockout
4. SDML = Slow Decelerate to Minimum Load
5. SDTI = Slow Decelerate to Idle
Gas turbine start sequence
1.       Purge sequence
1.1   The hydraulic start system is enabled and motor start is started.
Notes:
1.1.1          If there is no feedback of motor then “hydraulic starter motor failed”.
1.1.2          If GG rotor speed does not reach to 300 RPM then “Hydraulic starter failed”.
1.1.3          If GG rotor speeds 4500 RPM to 8000 RPM and gas turbine lube oil pressure does not above 6 PSIG then “Turbine lube oil supply pressure failed”.
1.1.4          If GG rotor speeds more than 8000 RPM and gas turbine lube oil pressure does not above 15 PSIG then “Turbine lube oil supply pressure failed”.
1.2   After 5 seconds of hydraulic system and motor started, GG is ramped up between 2200 – 2300 RPM (100%output of control).
1.3   When GG reaches 2000 RPM then purge timer is enabled.
Notes:
1.3.1          There is three (3) times of volume of engine and exhaust for purging.
1.3.2          During purging time, the permissive and finished to purge will be activated to relative system.
2.       Acceleration / fuel and ignition sequence
2.1   When purge is completed then acceleration / Fuel & ignition sequence is started.
2.2   GG is ramped down 1700 RPM and igniter is energized and hydraulic speed is ramped up to 100% of control.
2.3   Gas fuel primary and secondary shutoff valves are opened.
2.4   Start / Run permissive signal is sent to Fuel control (Woodward governor/MicroNet).
2.5   The “Fail To Lightoff Check Timer” is initiated.
Note:
2.5.1          If flame has not been detected and “Fail To Lightoff Check Timer” is timed out then “Fail To Lightoff Purge” is initiated and sequencing actions:
·         Gas fuel shutoff valve is closed.
·         Gas fuel vent valve is opened.
·         Gas fuel primary and secondary shutoff valves are closed.
·         Start/Run to fuel control (Woodward governor) is reset.
·         Igniter is switched off.
·         Purge timer is initiated, when it is timed out then hydraulic starter is de-energized and hydraulic motor is switched off respectively.
·         Shutdown sequence is initiated.
2.6   The flame is detected then “GG Acceleration Check Timer” is initiated.
Note:
2.6.1          If GG does not reach to 4500 RPM and “GG Acceleration Check Timer” is timed out then “GG Acceleration Failed” is initiated.
2.7   When “GG Acceleration Check Timer” and GG speed reaches 4500 RPM then “GG Idle Fail Check Timer” is initiated, vibration monitor inhibit is removed, igniter is switched off, hydraulic start system is cleared (0% control output) and hydraulic motor is stopped.
Note:
2.7.1          If “GG Idle Fail Check Timer” is timed out and GG speed does not reach to 6800 RPM then “GG Idle Speed Failure” is initiated.
2.8   When GG speed reaches 6800 RPM then acceleration/fuel & ignition sequence is completed and warm up sequence is initiated.
 3.       Warm up sequence
3.1   “GG warm up and PT breakaway Timer” is initiated.
Note:
3.1.1          If PT does not reach 350 RPM within 15 seconds then “PT Breakaway Failure” is initiated.
3.2   When GG warm up is timed out then GG idle signal to Woodward governor MicroNet Fuel control is cleared and GG increases speed to achieve PT minimum governor speed and “PT Acceleration Speed Check Timer” is initiated.
Note:
3.2.1          If PT does not reach to 2379 RPM and “PT Acceleration Speed Check Timer” is timed out the “PT Acceleration Speed Failure” is initiated.
3.3   When PT speed reaches to 2379 RPM then anti-surge controller, load sharing controller and compressor overall recycle controller are enable and “read to load” is set.
 

Hydraulic Start System

Fuel Gas System


Fuel Selection Logic, Woodward Governor

Continuous...
References:
1. GE LM2500+  Gas Turbine Generator Basic Operator / Package Familiarization Training Course.
2. Dresser-Rand Compressor (LM2500 G4 Driven) Control Systems Operation Manual. 

Friday, July 6, 2012

Glycol Gas Dehydration
Process Flow Diagram
There are two principles of main equipment that were applied:
1. Absorber
2. Distillation

The Glycol contactor is using abosorber by using Glycol to absorb water vapour carry over with hydrocarbon gas. The bottom of Gly contactor is designed to be vertical separator and the top is designed to be absorber by using structured packing.

(shown Glycol contactor, Glycol cooler, Glycol flash drum, Sock filters and Carbon filter)




(Shown condenser, still column, reboiler, stipping column, rich/lean heat exchanger, surge drum, circulated pump, chemical injection pump, BTEX heat exhanger, BTEX drum and BTEX blower)


cont...


Thursday, July 5, 2012

Offshore wellhead SCADA system

Integrated Honeywell PKS R310 servers connected to SR-500 central station via terminal servers to wellhead platform outstation radio that ControlLogix PLC was connected.


Honeywell SCADA, terminal servers and SR 500 central station system aechitecture



Some part of system the SR500 central station and Outstations (Slim10)

Outstation (Slim10) and ControlLogix PLC at wellhead platform

Cont...





Offshore Production ICSS (Integrated control and safety system)


(Architecture of ICSS)
This system was implemented by Yokogawa Centum VP, Prosafe, PRM, SIOS and Exaquantum.
The process control system (PCS) used Centum VP and Foundation FieldBus, The SIS and FGS used Prosafe.
The plant resource manager PRM was used for interface to FF-H1 and HART, see below.




















(PRM configuration)
The SIOS was used to interface to OPC RSLinx of ControlLogix from Rockwell.
The Exaquantum was used for historian data to interfacing to end user network.

(Exaquantum severs and ICSS configuration)

cont...

Wednesday, July 4, 2012

Foundation Fieldbus

Foundation Fieldbus (FFB)

All of foundation fieldbus devices have be registered to http://www.fieldbus.org/index.php?option=com_content&task=view&id=85&Itemid=199
and this mark has to stamp on product but I found some of field instrument and DCS were failed communication so recommendation such Yokogawa CentumVP and K-TEK magnetic float level transmitter.







Cable distance limitation

Total signal length = trunk + all spur, max allowed length is 1900 meters, trunk or homerun cable is 16 AWG multi-pair individual shielded and Spurs, max length shall be 200 meters.
cont...

Sunday, July 1, 2012

Fisher control valve

Fisher control valve available class rating
This table present class rating of each particular model of Fisher control valve


Butterfly
V150
V200
V300
CV500,V500
V250,V260
E,YD,YS
GX
HP,EH
ANSI 150
X
X
X

X
X
X
X

ANSI 300
X

X
X
X
X
X
X

ANSI 600
X

XXX

X
X
X


ANSI 900
X




XX
XX

X
ANSI 1500
XX







X
ANSI 2500








X
ANSI 4500








X

















Notes:
XX, it will have class 900 pressure boundary rating with class 600 pressure differential rating for the trim.
XXX , it will have class 600 pressure boundary rating with class 300 pressure differential rating for the trim.

See valve model: 


































 Travel range limits
To prevent poor installed gain characteristics into the process control system, the calculated of Cv should fall between the following travel ranges.
  • Butterfly valve 25% to 45 %
  • Segmented ball valves 20% to 60%
  • Plug style valve 20% to 70%
  • Ball valve 20% to 70%
  • Sliding stem valve 15% to 85%
The globe valve is a sliding stem valve that has a widely range so it always is a choice to use but it is limited by body size, the ball valve is the next choice, butterfly valve is used for fire water and service water. For oil and gas process application uses ball valve.   

Cont...