Lesson 9: Aux Cooling Water (ACW) and Heat Exchanger System

Question 1

1. What is the purpose of the Auxiliary Cooling Water System?

Answer 1

ACW cools equipment throughout the plant.

Question 2

2. What is the difference between the auxiliary cooling water system and the auxiliary circulating water system?

Answer 2

ACW cools equipment, while the Aux. Circ. Water removes the heat from the ACW.

Question 3

3. Draw a simple one line diagram showing how the auxiliary cooling water system works.

Answer 3

ACW Storage Tanks - Booster Pumps – Surge Tanks – ACW Pumps – Equipment – Heat Exchangers- ACW pumps

Question 4

4. What type of water do we use in the Aux. Cooling water system? What do we treat it with?

Answer 4

Condensate mixed with Cortex and green dye.

Question 5

5. What voltage is the Aux. Cooling Water pump motor?

Answer 5

480 Volts

Question 6

6. What is the purpose of the surge tank on the turbine floor?

Answer 6

The surge tank maintains head pressure on the ACW system and prevents surging within the system.

Question 7

7. What keeps the surge tank full or at normal level?

Answer 7

ACW make up pump and storage tanks.

Question 8

8. If you need to raise the level of the Aux. Cooling water storage tank, where would you get the water?

Answer 8

Condensate is pumped into the top of the storage tank.

Question 9

9. Why is the temperature control valve located on the discharge of all coolers?

Answer 9

This allows for more consistent temperature control.