ML20043F668
| ML20043F668 | |
| Person / Time | |
|---|---|
| Issue date: | 02/12/2020 |
| From: | Office of the Chief Human Capital Officer, Woodard Corp |
| To: | |
| Gary Callaway | |
| Shared Package | |
| ML20043F634 | List:
|
| References | |
| Download: ML20043F668 (22) | |
Text
Emergency Diesel Generator Some Other Engines Rev 3/16 14-1 of 22 USNRC HRTD 14.0 SOME OTHER ENGINES Learning Objectives As a result of this lesson, you will be able to:
- 1. Recognize basic similarities and differences between the engines that power EDGs at nuclear power plants.
- 2. Use the tabulation at the end of this chapter to identify the EDGs and associated equipment in use at various nuclear power plants.
NOTE: Except for the EMD engine which begins this Chapter, most of the other engines are essentially orphans no longer in production. Service and support may be very problematic for the few plants using them. Further, little information about those engines was available to include here.
14.1 EMD EDG Engines The EMD EDG engines were originally designed and built by the Electro-Motive Division of General Motors. The EMD 645 Series is a 2-stroke cycle, 45o Vee engine.
These engines have intake ports in the lower end of each cylinder liner, and four exhaust valves in each cylinder head.
During starting and up to about 40 percent load, the turbocharger that provides cylinder exhaust scavenging and combustion air is gear driven by the engine, until the exhaust gases get hot enough to drive the turbocharger faster than the drive gear.
Then the turbochargers drive gear is overridden (clutched out). NOTE: To avoid cycling of the turbocharger drive clutch, operating this engine at about 40% load for a prolonged time is not recommended.
EMD turbochargers are lubricated both by engine oil and a separate soak-back oil system that pre-lubes (before routine start) and post-lubes (after shutdown). The latter protects the hot turbocharger during its run-down period, and then another 30 minutes (to remove residual heat from the system).
Each engine cylinder fuel pump and fuel injection nozzle are combined into a unit-type construction, thereby eliminating the need for high pressure fuel injection lines.
For each bank of this Vee engine, the cam shafts are located above the cylinder heads.
From this location, they directly actuate two rocker arm assemblies:
one for the four exhaust valves one for the unit fuel pump/injector Unlike other engines, pushrods from the camshafts are not required.
Cylinders are directly opposite each other.
Connecting rods from directly opposite side cylinders use a common connecting rod journal without offset by means of their mating fork-and-blade slipper assembly.
Lubrication cooling of the each piston crown is accomplished by use of an engine frame-mounted piston-cooling oil pipe that is aligned with a hole in the piston carrier to send a jet stream of oil directly into the piston cocktail shaker for crown cooling and wrist pin lubrication. The oil then drops back into the crankcase.
EMD has built engines similar to the 645 Series since the 1930s. The company was acquired by Caterpillar, Inc. in 2010. Some design and performance data follow:
Emergency Diesel Generator Some Other Engines Rev 3/16 14-2 of 22 USNRC HRTD Figure 14-1 is a cutaway cross section of the EMD 645 engine. It provides some perspective of engine con-figurations and component locations.
Figure 14-2 is an EMD engine data sheet.
14.2 Cooper EDG Engines The Cooper EDG engines are 4-stroke cycle Enterprise KSV V16 and V20 cylinder engines. Cylinders on opposite sides of the Vee are directly opposite each other. The use of articulating connecting rods permits the use of a single crankshaft journal without offset for both cylinders. There is a master connecting rod that provides the bearing and transmits both connecting rod loads/power into the single crankshaft journal. The master rod has a bushing bearing for the slave rod. The connecting rods and bearings are shown in Figure 14-3.
Cooper engines had 13 crankcase explosion events attributed to lack of lubrication. These engines were designed for continuous use with minimum oil consumption. The lack of lubrication was corrected by removal of the lower scraper ring on each piston and removal of wrist pin bearing end caps.
Some design and performance data for the Cooper 16-and 20-cylinder engines are provided:
Figure 14-4 is a Cooper KSV Engine General Data Sheet.
Two cutaway cross-sections provide some perspective of the engines configuration and component locations.
(See Figures 14-5 & 14-6)
Figure 14-7 provides a bar graph of engine timing. (This figure is typical for 4-stroke cycle diesel engines.)
14.3 Nordberg EDG Engines The Nordberg EDG engine is a 4-stroke, cycle, 16-cylinder, Vee engine. Its design is rather typical of other engines its size and it runs at a relatively slow 514 RPM.
This engine has a unique cam-shifting mechanism, which will (in response to changes in load) shift combustion air inlet valve closure from its initial 18 degrees ABDC to 28 degrees BBDC at engine full load. Actuator sensing for valve timing is from the combustion air intake manifold pressure. The actuator is operated by a hydraulically-positioned linkshaft which repositions the camshaft. The inlet valve cams have an eccentric configuration. This system is illustrated in Figure 14-8.
Some design and performance data for the Nordberg engine are provided:
Figure 14-9 provides general engine data.
Figure 14-10 provides recommended operating temperatures and pressures.
Figure 14-11 is a cutaway cross-section.
It provides some perspective of engine configuration and the location of components.
14.4 Worthington EDG Engines The Worthington EDG engine is a 4-stroke cycle Vee engine. Opposite side cylinder connecting rods use a single crankshaft journal and mount directly beside each other, so their cylinders are slightly offset.
Emergency Diesel Generator Some Other Engines Rev 3/16 14-3 of 22 USNRC HRTD At the D. C. Cook Plant, the high pressure fuel injection lines from the injection pumps to the injection nozzles experienced some cavitation erosion failures in sharp bends made in routing the fuel lines from injection pumps to injection nozzles. This problem, described in a Chapter 13 case history, has been resolved.
Some design and performance data for the Worthington engine are provided:
- Figure 14-12 is a cutaway engine cross section. It provides some perspective of engine configurations and components locations.
- Figure 14-13 provides general engine data.
- Figure 14-14 provides a circle timing diagram to show the timing of all engine events during the 4-stroke cycles of the engine. (Typical for other 4-stroke cycle engines.)
14.5 SACM EDG Engines The SACM UD 45 V16 S5D engine is a 4-stroke cycle engine used only at Calvert Cliffs and Prairie Island nuclear stations.
The Calvert Cliffs configuration has two SACM engines connected in tandem to power a single 5400kw generator. There are two tandem units-one safety related and one SBO unit. Each engine is provided with a Woodward 2301A electrical governor and a Woodward EGB-35P governor actuator, which permits engine load sharing as they both power their common generator.
Following Calvert Cliffs successful pre-op qualification testing of their new SACM safety related EDG, the licensee performed progressive external to internal and then to disassembly inspections of the engines.
Extensive cylinder liner/piston skirt damage was discovered, which could have led to EDG failure to meet an emergency demand.
Multiple causes were identified by the Root Cause Analysis Team, relating to reactions involving lubricating oil additives, one the result of changing to low sulfur diesel fuel oil.
Corrective actions included engine repairs/
replacements and lube oil change to an API-CG-4 mineral-based oil recommended by the root cause analysis team. This case history is covered in Chapter 13. Reference IN 96-67.
- Figure 14-15 provides general engine data.
- Figure 14-16 provides general generator data.
NRC NOV EA-02-068 cited Prairie Island with a $60,000 penalty for failure to take action to address EDG problems in a timely manner.
14.6 DeLaval EDG Engines The DeLaval EDG uses the 4-stroke cycle Enterprise RSV-V-16-4 engine, the largest in nuclear plant EDG service. It runs at low speed, only 450 RPM.
The DeLaval, like other EDG engines, is subject to large pressures and forces as it operates. See Figure 14-16. Consider the 17-inch diameter piston in the DeLaval engine. With 1500 psi peak firing pressure, it must carry a peak load on each piston of 340,000 pounds, 225 times per minute. This load is transmitted from the piston through its wrist pin bearing to the connecting rod
Emergency Diesel Generator Some Other Engines Rev 3/16 14-4 of 22 USNRC HRTD bearings and then to the crankshaft journal.
The large forces of combustion are contained and resolved within the engine by structural components. Fortunately a large percentage of these forces create useful work by their rotation of the engine crankshaft to produce useable output power. However, when some cylinders fail to produce their share of output power, the unbalanced forces can be large enough to become destructive.
Some design and performance data for the DeLaval engine are provided:
- Figure 14-17 provides general engine data.
- Figure 14-18 provides a cross sectional illustration of the DeLaval articulating connecting rod assembly. It provides some perspective of the engines configuration and the location of components.
Emergency Diesel Generator Some Other Engines Rev 3/16 14-5 of 22 USNRC HRTD Figure 14-1 EMD Engine Cross Section
Emergency Diesel Generator Some Other Engines Rev 3/16 14-6 of 22 USNRC HRTD Figure 14-2 EMD Engine Service Data Sheet
Emergency Diesel Generator Some Other Engines Rev 3/16 14-7 of 22 USNRC HRTD Figure 14-3 Cooper Engine Connecting Rods & Bearings
Emergency Diesel Generator Some Other Engines Rev 3/16 14-8 of 22 USNRC HRTD Figure 14-4 Cooper Engine Service Data Sheet
Emergency Diesel Generator Some Other Engines Rev 3/16 14-9 of 22 USNRC HRTD Figure 14-5 Cooper Engine Cross Section
Emergency Diesel Generator Some Other Engines Rev 3/16 14-10 of 22 USNRC HRTD Figure 14-6 Cooper Engine Cross Section
Emergency Diesel Generator Some Other Engines Rev 3/16 14-11 of 22 USNRC HRTD Figure 14-7 Cooper Engine Timing Bar Graph
Emergency Diesel Generator Some Other Engines Rev 3/16 14-12 of 22 USNRC HRTD Figure 14-8 Nordberg Engine Linkshaft
Emergency Diesel Generator Some Other Engines Rev 3/16 14-13 of 22 USNRC HRTD Figure 14-9 Nordberg Engine Service Data Sheet
Emergency Diesel Generator Some Other Engines Rev 3/16 14-14 of 22 USNRC HRTD Figure 14-10 Nordberg Engine Operating Pressures & Temperatures
Emergency Diesel Generator Some Other Engines Rev 3/16 14-15 of 22 USNRC HRTD Figure 14-11 Nordberg Engine Cross Section
Emergency Diesel Generator Some Other Engines Rev 3/16 14-16 of 22 USNRC HRTD Figure 14-12 Worthington Engine Cross Section
Emergency Diesel Generator Some Other Engines Rev 3/16 14-17 of 22 USNRC HRTD Figure 14-13 Worthington Engine Service Data Sheet
Emergency Diesel Generator Some Other Engines Rev 3/16 14-18 of 22 USNRC HRTD Figure 14-14 Worthington Timing Diagram
Emergency Diesel Generator Some Other Engines Rev 3/16 14-19 of 22 USNRC HRTD Figure 14-15 SACM Engine Service Data Sheet
Emergency Diesel Generator Some Other Engines Rev 3/16 14-20 of 22 USNRC HRTD Figure 14-16 SACM Generator Service Data Sheet
Emergency Diesel Generator Some Other Engines Rev 3/16 14-21 of 22 USNRC HRTD Figure 14-17 DeLaval Engine Service Data Sheet
Emergency Diesel Generator Some Other Engines Rev 3/16 14-22 of 22 USNRC HRTD Figure 14-18 DeLaval Engine Articulating Connecting Rod Assembly