ML20043F635
| ML20043F635 | |
| Person / Time | |
|---|---|
| Issue date: | 02/12/2020 |
| From: | Office of the Chief Human Capital Officer, Woodard Corp |
| To: | |
| Gary Callaway | |
| Shared Package | |
| ML20043F634 | List:
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| References | |
| Download: ML20043F635 (35) | |
Text
Chapter 7 DIESEL ENGINE STARTING SYSTEMS
Learning Objectives As a result of this chapter, you will be able to:
- 1. Describe the requirements for starting an EDG in a nuclear power plant application.
- 2. Identify the components and describe operation of a typical starting air supply system used in a nuclear plant application.
- 3. Identify the components and describe operation of a direct air injection, compressed air diesel engine starting system.
Learning Objectives (continued)
- 4. Identify the components and describe operation of an air motor type, compressed air diesel engine starting system.
- 5. Identify the components and describe operation of an electric motor type, diesel engine starting system for a nuclear power plant application.
Typical Technical Specification Starting Requirements Minimum of Rated Speed or 60 Hz +/- 1.2 Hz.
Rated voltage +/- 8% (4160 v +/- 320 volts) 10 seconds
Starting Elements Pre-warmed and pre-lubed engine Starting systems fully charged Redundant starting systems Governor boost system Capacity for multiple, consecutive, repetitive starts attempts
Starting systems function to:
Initiate, and quickly achieve, rapid engine rotation to reach fuel ignition temperatures in combustion air. Refer to Figure 7-1.
Figure 7-1 Cranking Speed vs.
Compression Pressure
Types of air-starting systems illustrated in Figure 7-2 Compressed air injected directly into engine cylinders, also known as 'air over piston' or the
'cylinder air start' system.
Compressed air injected directly into the vanes of starting air motors equipped with Bendix to engage the engine flywheel.
Figure 7-2 Starting Air Systems Figure 7-2-A Starting Air System
Figure 7-2-A Starting Air Admission Valve (Solenoid Activated)
Figure 7-4 Starting Air Distributor (FM OP Engine)
Figure 7-5 Spool Valve Off Cam Starting Air Off.
Figure 7-6 Spool Valve High Cam Starting Air ON
Figure 7-7 Spool Valve Low Cam Starting Air ON Signal to Check Valve
Figure 7-9 Starting Air Check Valve Closed
Figure 7-8 Starting Air Check Valve Open
Figure 7-2-B Starting Air System
Figure 7-10 Vane-Type Starting Air Motor
Figure 7-11 Bendix Drive Assembly In order to meet 10-second fast starting requirements, EDG units often include a governor or fuel rack boost system. The governor boost cylinder is illustrated in Figure 7-12.
Figure 7-12 Governor Boost Cylinder (Woodward Governor Co.)
A typical starting-air supply system is shown in Figure 7-13. Its system components include:
Air compressors Air aftercoolers and driers Air storage receivers (tanks),
with isolation and safety valves Operating control pressure switches Pressure relief valves
Figure 7-13 Starting Air Supply System Pictorial illustrations of typical components of a direct air-over-piston starting system are shown on Figure 7-14.
Figure 7-14 Typical Components of Direct Air-Over-Piston Starting System
Figure 7-14-A Typical Components of Direct Air-Over-Piston Starting System
Figure 7-14-B Typical Components of Direct Air-Over-Piston Starting System
A comprehensive diagram showing an overall direct air-over-piston starting system is shown in Figure 7-15.
Figure 7-15 Typical Direct Air-Over-Piston Starting System
Figure 7-15-A Typical Direct Air-Over-Piston Starting System Figure 7-15-B Typical Direct Air-Over-Piston Starting System An electric starting motor with bendix is shown in Figure 7-16. This system is used on some EMD units.
It is recommended that any electrical starting system have its own battery set and not rely on the station battery system.
Figure 7-16 Electric Starting Motor (with Bendix)
END OF CHAPTER 7