Alternative Fuel Vehicles

Alternative Fuel Vehicles
An Introduction

Prof. David Bernstein
James Madison University

Computer Science Department

bernstdh@jmu.edu

Traditional Fuel Vehicles

Components:
- Fuel tank
- Internal combustion engine - fuel/air mixture is ignited causing an explosion that moves the pistons
- Fuel pump - transfers fuel from the tank to the engine
- Carburetor or fuel injection system - creates the fuel/air mixture
- Transmission - Transfers mechanical power from the engine to the wheels
Fuels:
- Gasoline - ignition occurs as a result of a spark (e.g., from the battery to start)
- Diesel - ignition occurs as a result of compression (i.e., without a spark)

Alternative Fuels for Internal Combustion Engines

Gasoline Engines:
- Ethanol (i.e., ethyl alcohol)
Diesel Engines:
- Bio-Diesel
- Dimethyl Ether
Custom Engines:
- Ammonia
- Compressed Natural Gas
- Liquefied Natural Gas
- Hydrogen

Electric Vehicles

Common Components:
- Motor
- Controller - manages the flow of electrical energy controlling both the speed and torque of the motor
- Transmission - transfers mechanical power from the motor to the wheels
Different Sources of Power:
- External Source - third rail or overhead, wireless transmission, solar
- Battery - lithium-ion, carbon-fiber structural
- Non-Battery Storage - supercapacitors, flywheels
- Internal Source - hydrogen fuel cell, formic acid fuel cell, internal combustion engine

Electric Vehicles - Interesting "Twists"

Electric Regenerative Braking:
- Uses a motor "running backwards" (in addition to the traditional friction braking system) to generate electricity that is stored in capacitors
Hydraulic Regenerative Braking:
- The vehicle's kinetic energy powers a pump that sends fluid from a low-pressure tank to a high-pressure tank
Vehicle-to-Grid (V2G):
- Electricity Return - The vehicle sells electricity in response to increased demand/price
- Throttling - The vehicle changes its charging schedule as a result of changes in the price

Air Engine Vehicles

Main Components:
- Compressed air tank (e.g., carbon fiber)
- Piston engine
Pros:
- No need for cooling, emissions control
- Low self-discharge rate
Cons:
- Expanding air must be heated
- Long refueling times
- Low efficiency (about half of internal combustion engines)

Steam Vehicles

Components:
- Fuel Tank
- Heat Source - combustion chamber, furnace
- Boiler - pressure vessel containing the water to be boiled and a heat transfer mechanism (e.g., water-tube or fire-tube)
- Water Pump supplies water to the boiler
- Motor - a reciprocating piston or turbine
- Cold Sink - emits waste heat
Types:
- Simple Engine - the expansion process in completed in the cylinder
- Compound Engine - the steam passes through a series of cylinders (e.g., side-by-side or end-to-end) with decreasing pressure