Assessment

What is the relationship between the feed water/natural gas pressure in the fuel gas heater? What happens in the event of a tube leak?

-Gas pressure (approx. 400psi) is lower than the IP FW pressure (approx. 700). - When a tube leak occurs, it pushes water into the gas side and hopefully get a liquid level alarm.

What will override and close the HRH bypass valve when at normal Pressure and Temp?

-Loss of condensate pumps, circ. water, loss of condenser vac (8 psi or higher) -inlet temp high (<400)

What is the NOx rate limit? Gas/oil. What do we normal control set points?

-Phase 2 limits: Gas 3.5 ppm and 18 ppm oil. -Phase 1 limits: gas 10.5ppm and 42ppm oil. -Phase 2 normal: 2.7ppm gas and 15-17 ppm oil -Phase 1 normal: 7.5-9ppm gas and 35-38 ppm oil

What is ammonia slip and how and why is it monitored?

-excess ammonia -We send out a test coupon out of the SCR during outages. We don't want to waste excess ammonia or release excess ammonia into the atmosphere.

What level will trip the condensate pump?

10''

What is the ST exhaust hood temperature during normal operation?

100-125

What is the low vacuum alarm/trip?

2.42/3.64psia

What is the maximum number of units that we can run on fuel oil at the same time?

3 units only according to our air permit.

What is the gas pressure at GT SRV valve (P1)?

390-475 psi.

What is the minimum lube oil temp to start a 7FA CT?

45

What is the bearing vibration alarm/trip?

5/7mil

What is the optimal heat rate of a CC?

<7000. We normally are well below 7000.

What are the most significant parameters indicating/effecting the efficiency of the unit at base load?

Ambient air temperature.

What is the low lube oil pressure trip for the CT? Where are the switches located?

Collector compartment remote bearing and LO skid.

What are the low water level trips?

Drums? HP - 24, IP - 13, LP - 46.5

What is Heat Rate? Why is it important?

Efficiency. The amount of energy we can get out of a unit of fuel. It determines how well our plant is operating. Better efficiency = more $$$.

Explain the term "air-in leakage" and how to monitor this.

If air and other non-condensable enters in to the condenser. We monitor with chemistry and by doing air leak test on the vacuum pumps. (We don't do the vac tests).

Explain the purpose of the economizer recirculation pump. How is this accomplished?

LP record pumps allow a portion of the feed water to recirculate, using the prehtr temp cont valve, and help raise the temperature of the water more efficiently rather than making a single pass through the economizer.

Name the areas of the plant to which the denim pumps supply water.

Make up to condenser, water wash, water injection.

If a piece of machinery needs a replacement motor and will be damaged if the new motor rotates the wrong way, the test equipment needed to test the rotation direction of the new motor is a _______________.

Motor & Phase Rotation Tester

What does a LP high drum level trip?

ST @ 10''

What are the permissive to roll the Steam Turbine?

ST reset, Auto start selected, Startup sequence not selected, MSP > 385.0 psi, MST > 640 degrees, all drains open, on turning gear, EOP no DC failure, MSV < 10%.

What does a sudden increase in condensate pump discharge sodium concentrations most likely mean?

There is a condenser tube leak that is letting in high sodium water from the cooling water.

What is the purpose of the LP Open Permit box?

To make sure the steam meets parameters for auto control. Steam is superheated so that the turbine isn't damaged.

What are the batteries used for?

To power emergency lube oil pumps in order to bring the turbines down with minimal damage in the case of power loss.

When operating a disconnect switch in the high voltage (HV) switchyard, what must be verified just after the switch is closed?

Verify that all 3 phases have made full engagement.

What kind of exciters do we have and what is the difference?

We have brushed exciters on the 7As which use brushes to feed current to the field. We have a brushless exciter on the ST which induces current to the field by a magnetic field.

How do we ensure that we don't exceed sulfur emissions when operating on fuel oil?

We use Validate sulfur content of the fuel oil by sampling.

What is the RESET SETPOINT button on the HP bypass for?

if the ST trips, then it locks the header pressure at the time of the trip. It will keep that set point until the operator resets.