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
There's Always More to Learn