Basics of Mechanical Engineering – Unit I: Energy and Its Utilization

Vocabulary flashcards summarizing key fuel types, energy resources, conversion technologies, and related concepts from Unit I of Basics of Mechanical Engineering.

Energy

Capacity of a system to do work and produce dynamic effects.

Power

Rate of doing work; generated in power plants as mechanical or electrical output.

Conventional Energy Source

Relatively cheap, widely used resource such as fossil fuels and nuclear fuel.

Non-Conventional Energy Source

Alternate resource used where conventional sources are insufficient; e.g., solar, wind, tidal.

Renewable Energy Source

Resource replenished naturally and not exhausted by use (solar, wind, hydro, biomass).

Non-Renewable Energy Source

Finite resource depleted with use (coal, petroleum, natural gas, nuclear).

Fossil Fuel

Hydrocarbon-based fuel formed from ancient plant and microorganism remains (coal, oil, gas).

Nuclear Fuel

Fissile material (e.g., U-235, Pu-239) whose fission heat powers nuclear reactors.

Solid Fuel

Fuel in solid phase such as wood, coal, charcoal, coke, briquettes.

Liquid Fuel

Fuel in liquid phase—crude petroleum derivatives, tar, alcohols—used in engines and furnaces.

Gaseous Fuel

Fuel in gaseous phase (natural gas, LPG, producer gas) used for clean, controllable combustion.

Peat

Lowest grade coal (≈57 % C) with high moisture; used as domestic fuel.

Lignite

Brown coal (25–35 % C, 66 % moisture); boiler and domestic fuel.

Bituminous Coal

Medium-rank coal (75–90 % C); common industrial and domestic fuel.

Anthracite

Highest-rank coal (92–98 % C); hard, shiny; boiler and metallurgical fuel.

Charcoal

Porous black solid obtained by slow pyrolysis of wood in limited air.

Coke

High-carbon solid produced by carbonizing bituminous coal; used in blast furnaces.

Soft Coke

Coke produced at 500–700 °C; softer, high volatile matter.

Hard Coke

Coke produced at 900–1000 °C; strong fuel for blast and cupola furnaces.

Briquetted Coal

Blocks molded from fine coal under pressure with binders to minimize grate losses.

Pulverised Coal

Dry, powdered low-grade coal used in cement kilns and metallurgical processes.

Calorific Value

Heat released per unit mass or volume of fuel on complete combustion.

Crude Petroleum

Naturally occurring liquid hydrocarbon formed by anaerobic decay under heat and pressure.

Advantages of Liquid Fuels

High calorific value, easy storage/handling, low combustion losses, rapid load change capability.

Disadvantages of Liquid Fuels

Higher cost compared with solid fuels.

Natural Gas

Naturally occurring methane-rich gas used for heating and power generation.

Liquefied Petroleum Gas (LPG)

Mixture of propane–butane gases stored under pressure as liquid for domestic use.

Advantages of Gaseous Fuels

Clean burning, easy control, low wear, adaptable to load changes, no ash or smoke.

Nuclear Fuel Cycle

Series of processes: mining, enrichment, fuel fabrication, reactor use, spent-fuel management.

Uranium-235

Naturally occurring fissile isotope widely used in light-water reactors.

Plutonium-239

Artificial fissile isotope bred from U-238; used in mixed oxide (MOX) fuel.

Thorium-232

Fertile isotope under research as alternative nuclear fuel.

Control Rods

Neutron-absorbing rods in a reactor core used to regulate fission rate.

Coolant (Nuclear)

Fluid removing heat from reactor core to steam generator (water, liquid metal, gas).

Hydroelectric Power Plant

Facility converting potential energy of stored water into electricity via turbines and generators.

Penstock

Large pipe conveying high-pressure water from reservoir to turbine in hydropower plants.

Solar Collector

Device that absorbs solar radiation and transfers heat to a working fluid.

Flat Plate Collector

Non-concentrating panel with black absorber plate and transparent cover for water heating.

Evacuated Tube Collector

Array of vacuum-sealed glass tubes with heat pipes achieving higher efficiency in cold climates.

Through-Pass Air Collector

High-efficiency air heater where air passes through perforated absorber material.

Unglazed Air Collector

Solar air heater using bare metal absorber without glazing; feeds pre-heated air to HVAC.

Concentrating Collector

Reflective system focusing sunlight to a receiver for high-temperature applications.

Parabolic Trough Collector

Linear parabolic mirror focusing sunlight onto a tube of heat-transfer fluid.

Parabolic Dish Collector

Dish-shaped reflector concentrating solar rays at a single focal point.

Power Tower

Central receiver system using heliostats to focus sunlight onto tower-top receiver.

Photovoltaic Effect

Generation of electromotive force when photons excite electrons in a semiconductor junction.

Solar Cell

Semiconductor device (photodiode) converting sunlight directly into DC electricity.

Solar Panel

Module comprising multiple solar cells wired together to produce usable power.

Solar Pond

Salt-gradient pond that stores solar heat in a hot, dense bottom layer for thermal use.

Upper Convective Zone (UCZ)

Top, low-salt, atmospheric-temperature layer of a solar pond.

Non-Convective Zone (NCZ)

Middle salinity-gradient layer preventing convection and acting as thermal insulator.

Lower Convective Zone (LCZ)

Bottom, high-salt layer of a solar pond storing heat at 70–85 °C.

Wind Energy

Conversion of wind’s kinetic energy into mechanical or electrical power via turbines.

Ocean Thermal Energy Conversion (OTEC)

Power generation using 20 °C temperature difference between warm surface and cold deep seawater.

Geothermal Energy

Heat extracted from Earth’s interior hot spots to produce steam for power generation.

Hot Spot (Geothermal)

Subsurface magma accumulation heating groundwater to form high-pressure steam.

Tidal Barrage

Dam across estuary harnessing ebb-flow water to drive turbines for electricity.

Biomass

Organic matter from plants, animals, and waste used as renewable fuel source.

Biogas

Methane-rich gas produced by anaerobic digestion of biomass; used for cooking and power.

Anaerobic Digestion

Decomposition of organic matter by bacteria in absence of oxygen to produce biogas.

Biodiesel

Methyl ester fuel made from vegetable oils or animal fats; diesel engine substitute.

Bioethanol

Alcohol fuel produced by fermenting sugars or starches; blended with gasoline (e.g., E85).

Methanol

Simple alcohol obtained from methane or wood distillation; toxic; specialty fuel.

Butanol

Fermentation-derived alcohol fuel with energy content ~10 % below gasoline.

E85

Motor fuel blend containing 85 % ethanol and 15 % gasoline.

Hard Biofuels

Dense pellets made from compressed biomass residues for combustion in boilers.

Biogas Plant

Underground digester where slurry decomposes anaerobically, releasing biogas and nutrient-rich slurry.

Advantages of Biomass Energy

Renewable, carbon-neutral growth cycle, waste reduction, eligibility for Renewable Heat Incentive.

Disadvantages of Biomass Energy

High boiler cost, large space needed, fuel collection challenges, seasonal availability, emissions.

Renewable Heat Incentive

Government scheme paying users for heat generated from renewable sources like biomass.

Solar Photovoltaic (PV) System

Array of solar panels plus inverter converting sunlight to grid-compatible AC power.