HT- Turbine building HVAC Flashcards
What is the purpose of the HT system?
Maintains turbine building environmental conditions suitable for personnel occupancy and safe operation of equipment
Why is the non-class battery room ventilated?
To prevent accumulation of hydrogen in excess of 2% during normal operation and shutdown conditions
How many outside air supply normal AHUs are provided for the turbine building?
Six, supplying 100% OSA to the turbine building area
What is different about the HT system line up during winter conditions?
25% of the air is recirculated from the turbine building and about 75% of the air is replenished from outside air
Operation of the Outside Air and Recirculation dampers and the A Exhaust fan in the turbine building is dependent on the position of what switch?
Winter Shutdown Mode Switch
What two positions does the HT winter shutdown mode switch have?
NORMAL
AUTO
How is operation affected when the HT winter shutdown mode switch is in NORMAL?
When outside air temperature falls to 36 degrees, the Outside Air Dampers and the Recirculation Damper will reposition such that 75% of the air comes from outside and 25% of the air comes from the Turbine Building
When outside air temperature rises to above 36 degrees the dampers will reposition back to normal such that 100% of the air comes from outside
The ‘A’ Turbine Exhaust Fan will stay running when the Winter Shutdown Mode Switch is in the NORMAL position
What happens when the HT Winter Shutdown Mode Switch is placed in AUTO?
Outside air dampers and recirculation damper will shift to the 75% outside 25% Turbine building position
When outside air temperature drops to 36 degrees the A Turbine Building Exhaust fan will stop
When outside air temperature rises above 36 degrees the A Exhaust Fan will start
What does NH do for the HT system?
Powers normal roof exhaust fans, battery room normal exhaust fans, and lube oil area, demineralizer room and elevator room normal exhaust fans
What powers the HT AHU fans?
NG
What system provides water for the air washers in the HT system?
DS
What system supplies air for the OSA intake dampers and recirculation dampers in the HT system? What would happen if that supply is lost?
Instrument Air
Normal supply dampers fail open and the recirc dampers fail closed
Where are the HT Normal AHUs located?
HTN-A01A, B, C – Yard north of the Turbine building
HTN-A02A, B, C – Outside on the 176’ Turbine building south side
Which HT normal AHU supplies air to the Non-Class Switchgear Room and Battery Room? How are the other rooms supplied?
HTN-A02C
transfer grills
Where are the controls for HT system located?
Plant northwest corner of the turbine building on the 100’
How many normal roof exhaust fans are provided for the HT system and what is their purpose?
Four fans provided to exhaust warm air from the turbine building ceiling area and to help force air up from the lower elevations
How many fans are provided for the non-class battery rooms?
Two 100% capacity normal exhaust fans
How would I know that a non-class battery room exhaust fan flow is low?
Low flow switch will cause an alarm at the local panel and in the Control Room
How many fans are provided for the Lube Oil room in the turbine building? What is their purpose?
Two 100% capacity normal exhaust fans
remove combustible gases and heat generated in the area
How many exhaust fans are provided for the elevator room in the turbine building?
One
Where is the HT Demin Area Fan Switch located?
100’ Turbine Building East Area
Where is the HT Elevator Exhaust Fan Switch located?
194’ Turbine Building Elevator room
What happens to the HT system if NKN-D41 is lost?
Power is lost to the Turbine Building HVAC panel, which means any operations will need to be done at the breakers
When does the HT system operate? Is it required for safe shutdown?
continuously during all modes
not required for safe shutdown
