A.B. Hopkins Generating Station Seal Oil and Hydrogen System

A. B. Hopkins Generating Station

OPERATING PROCEDURE

Seal Oil And Hydrogen System
HOPKINS REPOWERING PROJECT
UNIT HP2A

A.B. Hopkins Generating Station Seal Oil and Hydrogen System

August 1 2014 Operating Procedure Unit 2 HP2A

TABLE OF CONTENTS

Section Page

1.0 Introduction 1

1.1 Purpose and Scope 1

1.2 System Identification and Scope Definition 1

2.0 SYSTEM STARTUP 1

2.1 Preoperational Procedures 1

2.1.1 Prerequisites 1

2.1.2 Prestart Requirements 1

2.2 Precautions and Limitations 2

2.3 Seal Oil and Hydrogen System Block Flow Diagrams 2

2.3.1 Electric Generator Auxiliary Systems 2

2.3.2 Seal Oil and Hydrogen System Diagrams 4

2.4 Replacing Generator Air with Carbon Dioxide 7

2.5 Replacing Generator Carbon Dioxide with Hydrogen 7

2.6 Placing the Generator Seal Oil System in Service 8

3.0 SYSTEM NORMAL OPERATION 9

3.1 System Routine Checks 9

4.0 SYSTEM ABNORMAL OPERATION 10

4.1 Gas Dryer Reactivation 10

5.0 SYSTEM SHUTDOWN 11

5.1 Removing Seal Oil System from Service 11

5.2 Purging Generator Hydrogen with Carbon Dioxide 12

5.3 Replacing Generator Carbon Dioxide with Air 12

5.4 System Post-Shutdown Checklist 13

5.4.1 Short Term 13

5.4.2 Long Term 13

6.0 ALARM RESPONSES 13

6.1 Summary of Alarms 13

7.0 CHECKLISTS AND TABLES 28

Table 1 - Power Supply Checklist 28

Table 2 - Prestart Valve Lineup Checklist 28

Table 3 - Local Indicating Instruments 30

Table 4 - Control Room Indicating Instruments 31

8.0 REFERENCES 31

8.1 P&ID 31

8.2 Electrical One Line Diagrams 31

8.3 Control Diagrams 31

8.4 Instrument Loop Diagrams 32

8.5 Instruction Manuals 32

8.6 Miscellaneous 32

Draft Page i

A.B. Hopkins Generating Station Seal Oil and Hydrogen System

August 1 2014 Operating Procedure Unit 2 HPA

1.0  Introduction

1.1  Purpose and Scope

The purpose of this operating procedure is to provide the operator with specific procedures for operating the Seal Oil and Hydrogen System and Associated Systems. The operating procedures include those detailed procedures required to start up, operate, and shut down the Seal Oil and Hydrogen System in a logical, efficient, and safe manner. The seal oil and hydrogen system cools the hydrogen-cooled generators. The operating procedure includes the following sections:

Ø  Section 2.0 - System Startup

Ø  Section 3.0 - Normal Operations

Ø  Section 4.0 - System Abnormal Operations

Ø  Section 5.0 - System Shutdown

Ø  Section 6.0 - Alarm responses

Ø  Section 7.0 - Checklists and Tables

1.2  System Identification and Scope Definition

The Seal Oil and Hydrogen System supports the hydrogen-cooled electric generators. The hydrogen cools the generator and the seal oil prevents the hydrogen from mixing with the atmosphere outside of the generator. The system contains the following subsystems and major components:

a.  Seal Oil System

b.  Gas System

2.0  SYSTEM STARTUP

2.1  Preoperational Procedures

2.1.1  Prerequisites

a.  The 125 VDC electrical distribution system is in service.

b.  The 480 VAC electrical distribution system is in service.

c.  The compressed air system is in service.

d.  The circulating water system is in service.

e.  The steam turbine and auxiliary system are ready for service.

f.  The fire protection system is in service.

g.  The main steam system is in service.

h.  The steam generation system is in service.

i.  The condensate cooling system is in service.

j.  The condensate and feedwater systems are in service.

2.1.2  Prestart Requirements

a.  All clearances are released and the equipment is in safe operating condition.

b.  The power supply lineup is correct per Table 1

c.  The prestart valve lineup is correct per Table 2.

d.  All system instrumentation is available per Tables 3 and 4.

e.  There are sufficient quantities of hydrogen and carbon dioxide on hand for filling the generator.

2.2  Precautions and Limitations

THE FOLLOWING PRECAUTIONS ARE SYSTEM SPECIFIC OPERATIONAL CONSIDERATIONS THAT MUST BE CLOSELY FOLLOWED. FAILURE TO FOLLOW THESE PRECAUTIONS MAY RESULT IN PERSONNEL INJURY OR EQUIPMENT DAMAGE.

a.  All pumps and heat exchangers must be filled and vented to ensure proper and efficient operation.

b.  The discharge valve on a positive displacement pump must be open prior to starting the pump.

c.  Absolutely no smoking or open flames are allowed in any areas of the hydrogen system.

d.  Immediately report any suspected hydrogen leaks. Leaks in the gas piping should be corrected immediately. A mixture of hydrogen in air is explosive from 4 to 74 percent by volume.

e.  Carbon dioxide must always be used as the scavenging medium to remove air or hydrogen from the generator. NEVER add air to hydrogen or hydrogen to air.

f.  Carbon dioxide is odorless, colorless, and tasteless. It is non-toxic but can cause asphyxiation because it displaces oxygen in confined spaces. Do not allow anyone to enter the generator until it is verified that the generator atmosphere is suitable for breathing.

g.  The gland seals must be supplied with oil whenever the shaft is rotating.

h.  The gland seals must be supplied with oil whenever there is hydrogen in the generator.

2.3  Seal Oil and Hydrogen System Block Flow Diagrams

2.3.1  Electric Generator Auxiliary Systems

2.3.2  Seal Oil and Hydrogen System Diagrams

2.4  Replacing Generator Air with Carbon Dioxide

ACTION / LOC / VERIFICATION
NOTE: The LOC column in this procedure specifies where the associated ACTION step is taken. A "C" step is performed in the Control Room, an "L" step is performed locally, and an "L/P" step is performed at a local panel. A "C/L" or "L/C" step indicates a combination of Control Room and local activities.
NOTE: For valve numbers referenced, see Section 2.3.2 Seal Oil and Hydrogen Diagrams.
1. VERIFY all gas system valves are aligned per Table 2. / L
2. DISCONNECT the hydrogen supply line removable link. / L
3. PLACE blanks on link flanges. / L
4. CLOSE valves 1, 3, 8, and 50. / L / Valves are closed
5. OPEN valves 2, 4, 5, and 7. / L / Valves are open.
6. OPEN CO2 bottle supply valves. / L / Valves are open.
7. OPEN valve 60. / L / Valve is open.
8. VERIFY carbon dioxide pressure on bottle header gauge. / L
9. VERIFY the purity meter on the Hydrogen Control Panel goes to 95% or greater CO2. / L / Hydrogen Control Panel purity meter.
10. CLOSE CO2 bottle supply valves. / L / Valves are open.
11. CLOSE valve 60. / L / Valve is closed.
12. CLOSE valves 2, 4, 5, and 7. / L / Valves are closed.
13. OPEN valves 1 and 3. / L / Valves are open.

2.5  Replacing Generator Carbon Dioxide with Hydrogen

ACTION / LOC / VERIFICATION
NOTE: The LOC column in this procedure specifies where the associated ACTION step is taken. A "C" step is performed in the Control Room, an "L" step is performed locally, and an "L/P" step is performed at a local panel. A "C/L" or "L/C" step indicates a combination of Control Room and local activities.
NOTE: For valve numbers referenced, see Section 2.3.2 Seal Oil and Hydrogen Diagrams.
1. REMOVE the hydrogen line removable link blanks. / L
2. REPLACE the hydrogen removable link. / L
3. OPEN valves 6, 8 and 53. / L / Valves are open.
4. OPEN valve 50. / L / Valve is open.
NOTE: In an emergency filling situation, valve 52 can be used to fill the generator faster.
5. ADJUST hydrogen pressure regulator to supply 60 psig hydrogen. / L
6. VERIFY the purity meter value reads 95% or greater hydrogen. / L / Hydrogen control panel purity meter.
7. CLOSE valve 6. / L / Valve is closed.
8. OPEN valve 24 for 2 minutes and then CLOSE valve. / L
9. ADJUST the hydrogen regulator as required to maintain the proper hydrogen pressure. / L
10. VERIFY the generator gas system maintains the proper hydrogen pressure and purity in the generator. / L/C / Hydrogen Control Panel or indicators in control room.

2.6  Placing the Generator Seal Oil System in Service

ACTION / LOC / VERIFICATION
NOTE: The LOC column in this procedure specifies where the associated ACTION step is taken. A "C" step is performed in the Control Room, an "L" step is performed locally, and an "L/P" step is performed at a local panel. A "C/L" or "L/C" step indicates a combination of Control Room and local activities.
NOTE: For valve numbers referenced, see Section 2.3.2 Seal Oil and Hydrogen Diagrams.
1. VERIFY electrical lineup per Table 1. / L
2. VERIFY the seal oil system valves are aligned per Table 2. / L
3. CLOSE turbine lube oil backup supply valves, 263 and 265. / L / Valves closed.
4. START the air side seal oil pump. / L / RED indicating light illuminates.
Pressure increases on local pressure indicator.
5. VERIFY hydrogen side drain regulator level increases. / L / Local level gauge.
6. VERIFY hydrogen side drain regulator level is maintained by drain (231) and fill (232) valves. / L / Local level gauge.
7. CLOSE air side seal oil outlet valve (254). / L / Valve is closed.
8. ADJUST the air side seal oil pump relief valve (258) until the pressure indicator reads 100 psig. / L / Local pressure indicator.
9. OPEN air side seal oil outlet valve (254). / L / Valve is open.
10. ADJUST the differential pressure regulator (256) to bring air side seal oil pressure to 12 psig above gas pressure. / L / Air side seal oil pressure indicator.
11. START the hydrogen side seal oil pump. / L / RED indicating light illuminates.
Pressure increases on local pressure indicator.
12. CLOSE hydrogen side seal oil valves 211 and 218. / L / Valves are closed.
13. CLOSE hydrogen side seal oil recirc valve 242. / L / Valve is closed.
14. ADJUST the hydrogen side seal oil pump relief valve (243) until the pressure indicator reads 100 psig. / L / Local pressure indicator.
15. OPEN hydrogen side seal oil valves 211, 218, and 242. / L / Valves are open.
16. ADJUST regulating valves 210 and 217 until the associated pressure gauges read ± 2" H2O. / L / Local pressure gauges.
17. ADJUST the backup main oil pressure regulating valve (291) to a 125 psig outlet. / L / Local pressure indicator
18. OPEN turbine oil backup supply valves 263 and 265. / L / Valves are open.
19. STOP the air side seal oil pump. / L / Green indicating light illuminates.
Pressure decreases on local pressure indicator.
AIR SIDE SEAL OIL PUMP OFF alarm annunciates at the Hydrogen Control Panel.
20. ADJUST the backup supply regulator (264) to maintain the seal oil supply at 8 psig above hydrogen pressure. / L / Local pressure indicators.
21. RESTART the air side seal oil pump. / L / RED indicating light is illuminated.
Pressure increases on local pressure indicator.
22. OPEN pressure switch PS-8 test valve (274). / L
23. When pressure on associate indicator reaches 5 psi, VERIFY the air side seal oil backup pump starts. / L / RED indicating light illuminates.
BACKUP SEAL OIL PUMP RUNNING alarm is annunciated at the Hydrogen Control Panel.
24. CLOSE pressure switch PS-8 test valve (274). / L
25. STOP the air side seal oil backup pump. / L / GREEN indicating light illuminates.
26. STOP the hydrogen side seal oil pump. / L / GREEN indicating light is illuminated.
Pressure decreases on local pressure indicator.
27. VERIFY the HYDROGEN SIDE SEAL OIL PUMP OFF alarm at the Hydrogen Control Panel. / L / Alarm annunciates.
28. RESTART the hydrogen side seal oil pump. / L / RED indicating light illuminates.
Pressure increases on local pressure indicator.

3.0  SYSTEM NORMAL OPERATION

3.1  System Routine Checks

ACTION / LOC / VERIFICATION
NOTE: The LOC column in this procedure specifies where the associated ACTION step is taken. A "C" step is performed in the Control Room, an "L" step is performed locally, and an "L/P" step is performed at a local panel. A "C/L" or "L/C" step indicates a combination of Control Room and local activities.
NOTE: Proper operation of plant equipment will lead to increased availability, sustained performance, and extended life of the equipment, while reducing the chance of failure. Proper operations include close adherence to operating procedures when starting the equipment, proper monitoring and inspections when the equipment is in normal operation, and following proper operating procedures when shutting down.
1. CHECK all indication listed in Tables 3 and 4, Local and Control Room Indicating Instruments. / C/L / Verify each is within the normal operating range.
2. CHECK the generator for unusual noises or vibrations. / L / No unusual noises or vibrations.
3. VERIFY hydrogen side seal oil pump operation. / L / Ø Check the bearings.
Ø Check for signs of leaks.
Ø Check motor/pump coupling.
Ø Check for abnormal noises or vibration.
4. VERIFY air side seal oil pump operation. / L / Ø Check the bearings.
Ø Check for signs of leaks.
Ø Check motor/pump coupling.
Ø Check for abnormal noises or vibration.
5. VERIFY generator seal oil vapor extractor operation. / L / Ø Check the bearings.
Ø Check motor/extractor coupling.
Ø Check for abnormal noises or vibration.
6. VERIFY hydrogen side seal oil drain regulator operation. / L / Ø Check the level.
Ø Check for signs of leaks.
Ø Check for valve/float malfunction.
7. VERIFY seal oil coolers operation. / L / Temperature between 80 and 120 °F.
8. ADJUST the seal oil regulating valves as require to maintain the proper seal pressure. / L / Ø Valve 256 maintains 12 psi difference.
Ø Valves 210 and 217 maintain ± 2" H2O.
9. Once per shift, ROTATE the seal oil knife filter handles. / L
10. VERIFY gas dryer operation and if required REACTIVATE per section 4.1 of this procedure. / L / Ø Check the two-way valves.
Ø Check for depleted (gray) desiccant.
Ø Check for gas leakage.
11. VERIFY the hydrogen control panel operation. / L / Ø Check purity blower operation.
Ø Test the annunciators.

4.0  SYSTEM ABNORMAL OPERATION

4.1  Gas Dryer Reactivation