1st CRO Board Questions

Question 1

How to place turbine on gear?

Answer 1

Oil temp satisfied, generator properly line up, take dogleg out of pull to lock, verify it starts on slow speed for 10 seconds then switches to high speed, check eccentricity on ATSI display (3mills is max)

Question 2

How to establish steam seals?

Answer 2

Line up either main steam or aux steam, Gland steam exhauster in service, BFPT on gear, exhaust trunks open, make sure regulator is closed before opening block valve, self sealing at 40% load

Question 3

How do we control steam temps and where are they regulated at?

Answer 3

Sprays primarily regulate superheat temps while the tilts regulate the reheater temps.

Superheat sprays go into the division panels

Reheat sprays go into the cold reheat going into the radiant reheat bypass header

Question 4

Name the runbacks

Answer 4

Loss of ID/FD
Loss of PA fan
Loss of BFP
Loss of stator coolant

Question 5

Describe a rundown, run up, and run back

Answer 5

Run up/Run down- These will run the unit up or down until the error clears

Runback- Brings the unit down to a safe load that it can operate at without that piece of equipment

Question 6

List the run ups and downs

Answer 6

Air, Fuel, Throttle pressure, Feedwater, PA pressure, Furnace pressure, Drum level, Hot well level, DA level, Condensate flow

Question 7

What is the difference in single element and 3 element

Answer 7

Single element mode is use during start up. The drum is only looking at the drum level to determine how much water needs to go to the drum.

3 element mode is used during normal operation. The drum instrumentation looks at steam flow, feedwater, and drum level to determine makeup to the drum.

Switches from single element to 3 element at 12% steam flow

Question 8

What is the purpose of biasing the boiler controls

Answer 8

Bias adjustments are made when abnormal operating conditions arise causing one piece of equipment to carry more or less load than the others

Question 9

Items needed for prewarming the turbine

Answer 9

Steam conditions met
SALI chart approved

Question 10

Different types of boiler hydros

Answer 10

Static hydro puts the water at drum level height to test waterwalls

Pressure hydro uses the BFP or condensate pump to pressurize the tubes. Uses the sprays to fill all parts of the boiler

Question 11

What’s the telltale for when cold filling the boiler?

Answer 11

To tell if the cold filling is leaking or not, BFV-52 is located in the basement

Question 12

Explain the turbine trip bypass

Answer 12

When enabled, if the turbine trips it will take the boiler with it. If bypassed, (during startup) and the turbine trips for some reason, you wont lose the boiler. Automatically enables after starting the 2nd feeder

Question 13

When do we de-energize the precip?

Answer 13

When the exit gas temp gets below 180°

Question 14

What is the purpose of the scanner air fans?

Answer 14

Provide cooling air to each of the flame scanners in the furnace.

Scanner air fans will auto start when furnace DP drops below 4.5” and stop when furnace DP gets to 24”

Question 15

What is the purpose of the ignitor air fans?

Answer 15

Ensure a constant flow of cooling air around each ignitor in the boiler

Question 16

What is the purpose of the roof enclosure fans?

Answer 16

Maintains approximately 2” above furnace operating pressure to prevent and accumulation of fly ash within the roof enclosure and leakage of hot flue gases through the furnace roof.

Question 17

When do we put precip blowers in service?

Answer 17

The heater blower system is placed in service approximately 8 hours prior to energizing the precipitators

The fly ash blower is placed in service when the system startup sequence is initiated

Question 18

Ramp rate

Answer 18

75° an hour
200° max an hour

Question 19

Interrupt switches on fans

Answer 19

The break away regulating lever is spring loaded and will break away in case the internal regulating assembly cannot follow the regulating impulses given by the external servo motor. This will prevent any damage to the internal components. The regulating lever is located on the fans beck drive blade positioner, These are associated with both the ID and the FD fan blades

Question 20

Purpose of the 02 controllers and what page they are on

Answer 20

02 control is on air flow master page. Controls excess 02, the setpoint is 3

Question 21

Flow path of cold filling the boiler

Answer 21

Line comes off condensate header after gland steam condenser to CDV-61, then to regulator valve BFV-41, and another block valve BFV-23 it ties into a 16” header to the HP heaters then to the economizer inlet header

Question 22

What is the process of burning out the silo’s?

Answer 22

@100 tons- lower coal air temp setpoint to 130°
@50 tons- lower feeder speed to 40-60 TPH
Place hot air damper in manual with cold air in auto, lower coal air temp to 100°-120°

Question 23

Normal and high throttle pressure

Answer 23

Normal-2400
High- 2525

Question 24

What are the 3 trip devices on the turbine?

Answer 24

• ETD Electronic trip device
• PTR primary trip relays
• ETR Electronic trip relays

Question 25

What chemistry levels are we looking for in the Hotwell, DA, and Boiler?

Answer 25

Hotwell-ph, millipores, hardness, DO DA-DO, millipores, hardness Boiler-hardness, sodium, silica, conductivity, ph

Question 26

How long does it take to fill the boiler and how much water does it hold?

Answer 26

86,000 gallons and it takes 1.5 to 2 hours to fill

Question 27

What is the purpose of the backpass drains?

Answer 27

Remove condensate Normal startup they will be two turns opened Hot turbine/ cold boiler conditions they will be wide open to help match up steam temps

Question 28

At what point is the turbine self sealing?

Answer 28

40% load

Question 29

What is the flow path from the economizer to the condenser?

Answer 29

Economizer inlet, collector drum, BWCP, lower drum, water wall, steam drum, roof SH, BP SH, SH division panels, vertical platen SH, Front pendant SH, HP turbine, Cold reheat, Front pendant RH, Rear pendant RH, IP, LP turbine, condenser

Question 30

When do we start the APH?

Answer 30

When starting the ID/FD fans

Question 31

When do we shut down the APH?

Answer 31

Air heater inlet temp 400°. It helps cool the boiler down faster

Question 32

How are safeties set up on the boiler?

Answer 32

Staggered because of pressure drop throughout the boiler and to maintain flow to the next component

Question 33

If you have a sharp increase in feedwater but steam flow stays the same what is this an indication of?

Answer 33

Tube leak

Question 34

What does BCS and BMS stand for?

Answer 34

BCS- Boiler control system, controls everything on the boiler BMS- Burner Management System, only controls fuel

Question 35

What are the tracking lights on controllers?

Answer 35

It means it is watching a different controller upstream of that controller. Allows seamless transfer from one controller to the next

Question 36

If the boiler trips what are the options for getting it back faster?

Answer 36

Save steam by dropping load (30%), bottle up your turbine, try to get a coal prelight permissive, once you hit 800psi/800° just bring it down because the steam will be saturated

Question 37

When a master fuel trip occurs what happens to airflow master?

Answer 37

Stays in auto and the controls will hold where they’re at for 5 minutes

Question 38

How is water circulated in the motor cavity cooler heat exchanger?

Answer 38

Water comes out the motor bottom and back in the top of the motor

Question 39

What boiler feed pump tests do we perform and why?

Answer 39

LP and HP stop valves (Daily), at low load can’t test HP ETD test (weekly) emergency trip device, Must test one at a time. Need both in at a time to cause an actual trip Oil pump tests (weekly) Reduced speed over speed trip test (yearly) We do these to prevent silica buildup on stem

Question 40

What is the startup process of the Boiler Feed Pump?

Answer 40

Turbine on gear All drains opened except high pressure above seat drain Oil Pumps on Vacuum established Warmed for 30 minutes Manually roll to 1500 RPM Line up with the deviation meter on mark 6 Push both controllers in auto Control setpoint from feedwater master set at -2

Question 41

What are the permissives for resetting a boiler feed pump?

Answer 41

Exhaust trunk open Suction valve open Suction pressure Control valve closed (V1)

Question 42

What are the boiler feed pump suction drains for?

Answer 42

Keeps the suction line warm while not in use

Question 43

List the boiler feed pump trips

Answer 43

Vibration Exhaust pressure Push button DA level low Oil pressure low Oil temp HiHi Zero speed

Question 44

What is a high oil temp on boiler feed pumps and turbine?

Answer 44

135° on BFP 130° is the high temp on MTLO

Question 45

What is the purpose of oil pumps on the boiler feed pumps?

Answer 45

Main oil pumps- 2 stages, HP and LP, HP control valves and stop valves. LP is for lubrication Emergency pump is for lubrication while bringing it down HP can also supply lubrication if LP was to go out.

Question 46

What do we use to control NoX?

Answer 46

Neural net and SOFA

Question 47

What Ph do we maintain boiler water at?

Answer 47

9.2 or so

Question 48

When can we line the air up to dry out the reheater?

Answer 48

When the temperature gets down to 300° on the cold and hot reheat on pi

Question 49

When can we drain the boiler?

Answer 49

200° at the BWCP suction manifold

Question 50

What do you need to do when breaking vacuum on the turbine?

Answer 50

Watch the mark 6 and when the vacuum decays shut off steam seals

Question 51

After shutting unit down when can you start making up water with cold fill?

Answer 51

When the drum pressure gets below 600lbs

Question 52

Where does the high BFP oil DP come in?

Answer 52

15 psi

Question 53

How to break vacuum in a normal situation

Answer 53

- Take turbine off, get it on gear - Pull to lock the standby vacuum pump - Put the running vacuum pump in off (dry out) - Open the vacuum breaker, monitor back pressure - Let it run up to 10” or 15” of back pressure, then take seals off to cool turbine

Question 54

What temperature does the bowl mill automatically inert?

Answer 54

170°

Question 55

What temperature will the hot air gate automatically close on the bowl mill?

Answer 55

180°

Question 56

What thrust bearing temperature does a bowl mill get a high temp alarm in?

Answer 56

170°

Question 57

What bowl mill temp does the feeder speed cut back to minimum?

Answer 57

Alarms at 170° The feeder goes to minimum at 190°

Question 58

What is something to monitor if you’re bringing the unit up or down?

Answer 58

Need to watch the APH sump for excess steam going into the fan room

Question 59

What is NOX and how do we control it?

Answer 59

NOX is a byproduct of combustion. We control it using the sofa dampers and neural net.

Question 60

What emissions do we monitor?

Answer 60

So2,Co2,opacity, and NOX

Question 61

What’s the difference in a process alarm and a system alarm?

Answer 61

Process alarm is a normal alarm in the process that can be cleared from the alarm screen. A system alarm is an alarm in the computer system that has to be dug into to be cleared.

Question 62

What are some important pressures on the condensate filter?

Answer 62

When the DP gets to 35 for 60 seconds, the filter will take itself out of service The maximum DP it is designed for is 50

Question 63

What chemistry setpoints are watched before rolling the turbine?

Answer 63

DO has to be less than 100 Silica has to be less than 20

Question 64

How much oil pressure is on the turbine and BFP?

Answer 64

14 on the turbine lube oil and 20 on the feed pump lube oil

Question 65

What safeties do we have on the boiler?

Answer 65

- Boiler Safety (8)- 2990-3080 psi - Main Steam Safety (4)- 2755-2765psi - Cold reheat Safety (10)- 650-720psi - Hot Reheat Safety (4)- 650-655