16 Appendices

16.1 Appendix A: Power Generation Subsystem Information

16.1.1 System Functional Narrative

The primary function of the Power Generation Subsystem is to provide electrical power to areas where utility electricity is unavailable. Initially, fuel is supplied at a set pressure from the fuel tank. This fuel is drawn into a Diesel Engine that provides torque output and is in turn controlled by a continuous signal originating from a Control Unit. The Diesel Engine is connected by a Coupling to the Alternator Unit. The Alternator Unit converts the torque input into a 3-phase electrical voltage which is the main output of the system. The Control Unit is powered by the alternator and uses a continuous signal from a built-in angular velocity sensor on the output of the diesel engine to control the engine speed.

16.1.2 System Schematic

The System Schematic of the Power Generation Subsystem shows the following flow chain:

• External Inputs: Fuel Supply (into Fuel Tank), Intake Air (into Diesel Engine)
• Fuel Tank → Fuel → Diesel Engine
• Diesel Engine → Torque → Coupling → Angular Velocity → Alternator Unit
• Alternator Unit → Voltage (System Output); also feeds Voltage back to Fuel Tank and Voltage x2 + Signal to Control Unit
• Control Unit → Signal → back to Diesel Engine

16.2 Appendix B: Item Functions

16.2.1 Operating Conditions (Power Generation Subsystem)

The Power Generation subsystem operating mode under consideration is steady, medium power loading. During this mode, no additional fuel is being supplied to the fuel tank save for recirculated fuel which for the sake of simplicity is not included in this model. It is assumed that system inputs of air and fuel comply with the operating requirements for the Power Generation subsystem. The Diesel Engine is set to medium speed, and the injector pump is open.

16.2.2 Subsystem & Component Functional Narratives

1. Fuel Tank (Component) — The fuel tank is used to store fuel, however during operation its main function is to provide a steady supply of fuel as required by the Diesel engine. Fuel supplied also contains contaminants which may affect the performance of the Diesel engine.
2. Diesel Engine (Subsystem) — The Diesel engine receives fuel from the fuel tank, intake air from the external environment, a continuous amplitude signal from the Control Unit and electrical voltage from the Alternator Unit during normal operation. It takes these inputs and converts them into its main output in the form of Torque. Note: The Diesel engine can be found in the MADE Palette (Diesel Engine, 1) or its constituent components can be built manually using the component descriptions below.
3. Air Filter (Component) — The air filter's function is to refine gas (intake air) by removing foreign contaminants and regulating mass flow rate. Its main outputs are still mass flow rate and contamination as filtration is only conducted for a specific size range of air particulate.
4. Engine (Component) — The internal combustion engine converts gaseous air and liquid fuel by combustion into mechanical rotational energy in the form of torque output. This output torque is supplied to the main coupling (connected to alternator unit) and injector pump.
5. Coupling 1 (Component) — The coupling converts the torque output from the Engine into angular velocity as its main output.
6. Lift Pump (Component) — The lift pump receives the angular velocity output from the Coupling 1 and Fuel static pressure from the Fuel Tank. Its output is to increase the fuel flow rate output.
7. Primary Fuel Filter (Component) — The primary fuel filter refines large contaminants supplied from the lift pump. Its main outputs are flow rate and contamination as filtration is conducted for a specific size of fuel particulate.
8. Secondary Fuel Filter (Component) — The secondary fuel filter refines small contaminants supplied from the lift pump. Its main outputs are flow rate and contamination as filtration is conducted for a specific size of fuel particulate.
9. (Item 9 not present in source numbering — source PDF jumps from 8 to 10.)
10. Injector Pump (Component) — The injector pump receives liquid fuel from the secondary filter, mechanical linear velocity from the Governor, and torque from the Engine. It uses these inputs to regulate fuel dynamic pressure.
11. Governor (Component) — The governor receives electrical voltage from the alternator unit, and a continuous amplitude signal from the control unit. It uses these inputs to control the mechanical linear velocity used to control the injector pump.
12. Coupling (Component) — The coupling converts the torque output from the Diesel engine into angular velocity output which is sent to the alternator unit.
13. Alternator Unit (Subsystem) — Converts the torque output from the Diesel engine and electrical voltage from the Control Unit into a voltage output which is the main output of the Power Generation Subsystem. Note: The Alternator Unit can be found in the MADE Palette (Alternator Unit, 3) or its constituent components can be built manually using the component descriptions below.
14. Shaft (Component) — The shaft functions to receive an angular velocity and transmits a rotational angular velocity.
15. Alternator (Component) — The alternator receives electrical voltage from the control unit and angular velocity from the shaft and converts these inputs into an electrical voltage output.
16. Frequency Meter (Component) — The frequency meter senses the angular velocity from the shaft and converts this input into a continuous frequency signal as its main output.
17. DC Exciter (Component) — The DC exciter converts the angular velocity output from the shaft into electrical voltage as its main output. This is because an alternator does not have a permanent magnet, and so the exciter supplies power to the coils on the alternator's rotor to create a magnetic field.
18. Control Unit (Subsystem) — The control unit receives electrical voltages from the alternator and DC exciter and converts this input into electrical voltage output. It also receives an additional continuous frequency signal sensed from the frequency meter which is processed and output as a continuous signal amplitude.

Appendix C: Item Failure Data

Table 10: Item Failure Data for Power Generation Subsystem

Item Name	Failure Rate (FPMH)	Duration of Operation (Hrs)	Mechanism	Fault	Failure Mode Ratio	Failure Description
Fuel Tank	20	24	Corrosive attack	Corroded	0.8	Corrosion cracking can generate cracks through which fuel may leak.
Fuel Tank	20	24	Corrosive attack	Pitted	0.2	Corrosion cracking can generate cracks through which fuel may leak.
Air Filter	500	24	Build-up of Debris	Blocked	0.4	Build-up of debris due to solid contaminants may cause blockage or interference in the flow of fuel.
Air Filter	500	24	Build-up of Debris	Interference	0.6	Build-up of debris due to solid contaminants may cause blockage or interference in the flow of fuel.
Engine	60	24	Abrasive wear	Scratched	0.2	Insufficient lubrication is causing adhesive wear, quickly leading to engine seizure.
Engine	60	24	Abrasive wear	Abraded	0.8	Insufficient lubrication is causing adhesive wear, quickly leading to engine seizure.
Coupling 1	100	24	High Cycle Fatigue	Fractured	1.0	Fatigue caused by vibrations cause the growth of fractures in the coupling interfaces.
Lift Pump	50	24	Abrasive wear	Scratched	0.4	Solid particles cause abrasive wear and scratching in the lift pump parts where fuel flows through.
Lift Pump	50	24	Abrasive wear	Abraded	0.6	Solid particles cause abrasive wear and scratching in the lift pump parts where fuel flows through.
Primary Fuel Filter	800	24	Build-up of Debris	Blocked	0.2	Build-up of debris due to solid contaminants may cause blockage or interference in the airflow to the engine.
Primary Fuel Filter	800	24	Build-up of Debris	Interference	0.8	Build-up of debris due to solid contaminants may cause blockage or interference in the airflow to the engine.
Secondary Fuel Filter	700	24	Build-up of Debris	Blocked	0.4	Build-up of debris due to solid contaminants may cause blockage or interference in the airflow to the engine.
Secondary Fuel Filter	700	24	Build-up of Debris	Interference	0.6	Build-up of debris due to solid contaminants may cause blockage or interference in the airflow to the engine.
Injector Pump	200	24	Impact Fatigue	Partial Crack	1.0	Mechanical shock due to movement of pump parts lead to impact fatigue and partial crack growth.
Governor	10	24	Dielectric Breakdown	Open Circuit	1.0	Over-current leading to dielectric breakdown caused an open circuit fault to occur.
Coupling	200	24	High Cycle Fatigue	Fractured	1.0	Fatigue caused by vibrations cause the growth of fractures in the coupling interfaces.
Shaft	80	24	Tensile Fracture	Fractured	0.9	Sustained high mechanical loads caused a tensile fracture leading to fracture and separation.
Shaft	80	24	Tensile Fracture	Separated	0.1	Sustained high mechanical loads caused a tensile fracture leading to fracture and separation.
Alternator	20	24	Dielectric Breakdown	Open Circuit	1.0	Over-current leading to dielectric breakdown caused an open circuit fault to occur.
Frequency Meter	5	24	-	-	-	-
DC Exciter	1	24	Burnout	Open Circuit	0.6	Transient electrical loads lead to a burnout causing open and short circuits.
DC Exciter	1	24	Burnout	Short Circuit	0.4	Transient electrical loads lead to a burnout causing open and short circuits.
Control Unit	40	24	Channel Degradation	Open Circuit	0.5	Line defects caused channel degradation and eventual open and short circuits.
Control Unit	40	24	Channel Degradation	Short Circuit	0.5	Line defects caused channel degradation and eventual open and short circuits.