Workbank

Front 1

Thermal Efficiency

Back 1

The extent of the energy conversion from heat to work. The thermal efficiency is the ratio of the net work of the cycle to the heat added. (e=Wnet/Qa)

Front 2

Otto Cycle

Back 2

An ideal cycle that assumesheat addition occurs instantaneously while the piston is at top dead center.It consists of four internally reversible processes.

1-2. Isentropic compression

2-3. Constant volume heat addition

3-4. Isentropic expansion

4-1. Constant volume heat rejection

Front 3

Diesel Cycle

Back 3

An ideal cycle thatassumes heat addition occurs during a constant-pressure process thatstarts with the piston at top dead center.

1-2. Isentropic compression

2-3. Constant pressure heat addition

3-4. Isentropic expansion

4-1. Constant volume heat rejection

Front 4

Dual Cycle

Back 4

An air-standard cycle that can be made to approximate thepressure variations more closely.

1-2. Isentropic compression

2-3. Constant volume heat addition

3-4. Constant pressure heat addition

4-5. Isentropic expansion

5-1. Constant volume heat rejection

Front 5

Displacement Volume

Back 5

The volume displaced by the piston as it moves between top dead center (tdc) and bottom dead center (bdc).

Front 6

Clearance Volume

Back 6

The minimum volume formed in the cylinder when the piston is at TDC is called the clearance volume

Front 7

Percent Clearance

Back 7

ratio of clearance volume and displacement volume (V2/V1-V2)

Front 8

Compression Ratio

Back 8

defined as the volume at bottom dead center divided by the volume at top dead center.

Front 9

Isentropic Compression Ratio

Back 9

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Front 10

Mean Effective Pressure

Back 10

A parameter used to describe the performance of reciprocating piston engines. It is a fictitious pressure that, if it acted on the piston during the entire power stroke, would produce the same amount of net work as that produced during the actual cycle.

Front 11

Brayton Cycle

Back 11

was first proposed by George Brayton for use in thereciprocating oil-burning engine that he developed around 1870.

1-2 Isentropic compression (in a compressor)

2-3 Constant-pressure heat addition

3-4 Isentropic expansion (in a turbine)

4-1 Constant-pressure heat rejection

Front 12

Back work ratio

Back 12

The fraction of the turbine work used to drive the compressor is called the back work ratio. (Compressor work/turbine work)

Front 13

Compressor efficiency

Back 13

the isentropic efficiency of a compressor is defined as the ratio of the work input required to raise the pressure of a gas to a specified value in an isentropic manner to the actual work input.

Front 14

Turbine Efficiency

Back 14

isentropic efficiency of a turbine is defined as the ratio of the actual work output of the turbine to the work output that would be achieved if the process between the inlet state and the exit pressure were isentropic.

Front 15

Fossil Fuels

Back 15

Fossil fuels primarily consist of natural gas, crude-oil-derived fuels, and coal. Non-renewable. Fossil fuels are made from decomposing plants and animals. These fuels are found in the Earth's crust and contain carbon and hydrogen, which can be burned for energy.

Front 16

Biofuels

Back 16

liquid, solid, or gaseous fuel produced by conversion of biomass such as bioethanol from sugar cane or corn, charcoal or woodchips, and biogas from anaerobic decomposition of wastes.

Front 17

Renewable fuel

Back 17

fuels produced from renewable resources. Examples include: biofuels and Hydrogen fuel.

Front 18

Non-renewable fuel

Back 18

Non-renewable energy comes from sources that will run out or will not be replenished in our lifetimes—or even in many, many lifetimes. Most non-renewable energy sources are fossil fuels: coal, petroleum, and natural

Front 19

Carbon Neutral Fuel

Back 19

Carbon-neutral fuel is fuel which produces no net-greenhouse gas emissions or carbon footprint.

Front 20

Non-carbon Neutral Fuel

Back 20

produces greenhouse emissions.

Front 21

Methane

Back 21

produced by waste digesters and landfills.

Front 22

Methanogenic Bacteria

Back 22

Methane is created in landfills by methanogenic bacteria. Methanogenic bacteria decompose these organic materials to produce primarily carbon dioxide and methane.

Front 23

Biodigester

Back 23

a system that biologically digests organic material, either anaerobic (without oxygen ) or aerobically (with oxygen).

Front 24

Ethane (C2H6)

Back 24

Ethane is the second simplest alkane followed by methane. It contains 2 carbon atoms and 6 hydrogen atoms. So the formula for ethane is C2H6. mainly used to produce ethylene, a feedstock to make plastics.

Front 25

Liquified Petroleum Gas

Back 25

produced at natural gas-processing plants consists of ethane, propane, and butane. LPG produced from crude oil at refineries also includes refinery gases such as ethylene, propylene, and butylene. LPG is stored in tanks under pressure as a liquid and is a gas at atmospheric pressure. At 38°C, the maximum vapor pressure is 208 kPa for commercial LPG.

Front 26

Natural gas

Back 26

is a mixture of hydrocarbons and small quantities of various non-hydrocarbons existing in the gaseous phase or in solution with crude oil

Front 27

Syngas

Back 27

(synthetic gas, historically called producer gas or town gas) is created by passing a less than stoichiometric amount of air or oxygen through a hot bed of coal or biomass particles. This is a process called gasification and is accomplished in a gasifier, where input air is restricted so that the main output is hydrogen and carbon monoxide along with nitrogen and carbon dioxide.

Front 28

Carbon monoxide

Back 28

Carbon monoxide (CO) is an odorless, colorless gas formed by the incomplete combustion of fuels.

Front 29

Hydrogen

Back 29

is manufactured by reforming natural gas, partial oxidation of liquid hydrocarbons, or extraction from syngas. For example, natural gas can be converted to H2, CO, and CO2 by a reaction with steam over a catalyst at 800°C–900°C. A further shift of CO and H2O to H2 and CO2 is then carried out, and the gas is cooled and scrubbed to remove CO2.

Front 30

Fractional Distillation

Back 30

the separation of a mixture into its component parts, or fractions.

Front 31

Gasifier

Back 31

where gasification takes place

Front 32

Particulate scrubber

Back 32

a scrubber in which a liquid is mixed with the gas to collect solids. In particulate scrubbers, the liquid is dispersed into the gas as a spray, and the liquid droplets are the main collectors for the solid particles.

Front 33

Heating value

Back 33

is the heat release per unit mass when the fuel, initially at 25°C, reacts completely with oxygen, and the products are returned to 25°C.

Front 34

Higher heating value

Back 34

when the water in the combustion products is condensed

Front 35

Lower heating value

Back 35

when the water in the combustion products is not condensed

Front 36

Latent heat of vaporization

Back 36

the thermal energy required for a liquid to vaporize to a gas or the amount that is released when a gas condenses to a liquid.

Front 37

Volumetric Analysis

Back 37

this method involves measurement of the volume of a solution whose concentration is known and applied to determine the concentration of the analyte. In other words, measuring the volume of a second substance that combines with the first in known proportions is known as Volumetric analysis or titration.

Front 38

Density

Back 38

mass per unit volume

Front 39

Autoignition Temperature

Back 39

is the lowest temperature required to initiate self-sustained combustion in a standard container in atmospheric air in the absence of a spark or flame.

Front 40

Flash Point

Back 40

indication of the maximum temperature at which a liquid fuel can be stored and handled without serious fire hazard. Flash point is the minimum temperature at which fuel will rapidly catch fire when exposed to an open flame located above a mixture.

Front 41

Ultimate analysis

Back 41

is an analysis of the composition of fuel which gives on mass basis, the relative amounts of carbon, hydrogen, oxygen, sulfur, ash and moisture.

Front 42

Cracking

Back 42

in petroleum refining, the process by which heavy hydrocarbon molecules are broken up into lighter molecules by means of heat and usually pressure and sometimes catalysts. Cracking is the most important process for the commercial production of gasoline and diesel fuel.

Front 43

Thermal Cracking

Back 43

a process in which hydrocarbons present in crude oil are subject to high heat and temperature to break the molecular bonds and breaking down long-chained, higher-boiling hydrocarbons into shorter-chained, lower-boiling hydrocarbons.

Front 44

Hydrogenation

Back 44

- a chemical reaction between molecular hydrogen and another compound or element, usually in the presence of a catalyst such as nickel, palladium or platinum.

Front 45

Aliphatic Hydrocarbon

Back 45

any chemical compound belonging to the organic class in which the atoms are connected by single, double, or triple bonds to form nonaromatic structures. Have open chains. ( 3 types: alkanes, alkenes and alkynes)

Front 46

Alkanes (paraffins)

Back 46

are saturated hydrocarbons and are composed ofcarbon and hydrogen atoms connected by single bonds (C–C or C–H bonds)

Front 47

Alkenes ( olefins )

Back 47

double bond. also have the formula CnH2n, but two neighboring carbon atoms share a pair of electrons forming a double bond.

Front 48

Alkynes

Back 48

triple bond. They can appear as intermediate species in the fuel-rich zone due to incomplete combustion.

Front 49

Aromatic Hydrocarbon

Back 49

polycyclic aromatic hydrocarbons (PAHs), can be formed in the refining process and can also be formed during incomplete combustion in the fuel rich zone.

Front 50

Specific Gravity

Back 50

the density of the fuel divided by the density of water at the same temperature.

Front 51

Viscosity

Back 51

a measure of a liquid’s resistance to flow.

Front 52

Distillation curve

Back 52

a graphical depiction of the boiling temperature of a fluid mixture plotted against the volume fraction distilled.

Front 53

Sulfur content

Back 53

Fuel sulfur content is the sulfur content of the fuel as a percentage of its mass. Sulfur is considered an undesirable contaminant because, when burned, it generates sulfur oxides.

Front 54

Octane number

Back 54

(ON) indicates the ability of a fuel to resist engine knock (onset of autoignition), an abnormal combustion phenomenon in a spark ignition engine. The higher an octane number, the more stable the fuel.

Front 55

Cetane number

Back 55

(CN) indicates the tendency of a fuel to autoignite when undergoing compression ignition.

Hint 55

A fuel with a high cetane number autoignites easily, resulting in a short ignition delay, the time between fuel injection and autoignition. The cetane number of a fuel correlates inversely with its octane number.

Front 56

Reid Vapor Pressure (RVP)

Back 56

Volatility is measured by Reid vapor pressure, which is the equilibrium pressure exerted by vapor over liquid at 37.8°C and is expressed in units of pounds per square inch (psi) absolute.

Hint 56

If the RVP is too high, too much of the gasoline will evaporate before reaching the engine, causing vapor lock.

Front 57

Automotive Gasoline -

Back 57

a carefully selected blend of alkanes (paraffins), alkenes (olefins), cycloalkanes (naphthenes), and aromatics, which varies slightly at different refineries and is blended slightly differently depending on geographic region and season of the year.

Front 58

Diesel

Back 58

a mixture of C10 to C15 hydrocarbons with a higher boiling point range than gasoline.

Front 59

Gas Turbine Fuel

Back 59

not limited by antiknock or ignition delay requirements and have a wide range of boiling points.

Front 60

Fuel Oil (for heating)

Back 60

any of various fractions obtained from the distillation of petroleum (crude oil). It covers a wide range of petroleum products, which have been divided into six grades.

Front 61

coal

Back 61

a heterogeneous mineral consisting principally of carbon, hydrogen, and oxygen, with lesser amounts of sulfur and nitrogen.

Front 62

Anthracite

Back 62

The highest rank of coal. It is a hard, brittle, and black lustrous coal, often referred to as hard coal, containing a high percentage of fixed carbon and a low percentage of volatile matter.

Front 63

Lignite

Back 63

brown coal, is a soft, brown, combustible, sedimentary rock formed from naturally compressed peat. It has a carbon content around 25–35%, and is considered the lowest rank of coal due to its relatively low heat content

Front 64

Bituminous coal

Back 64

or black coal, is a type of coal containing a tar-like substance called bitumen or asphalt.

Front 65

Sub-bituminous Coal

Back 65

a lower grade of coal that contains 35–45% carbon. The properties of this type are between those of lignite, the lowest grade of coal, and those of bituminous coal, the second-highest grade of coal. Sub-bituminous coal is primarily used as a fuel for steam-electric power generation.

Front 66

Biomass

Back 66

a range of organic materials recently produced from plants and waste from animals that feed on plants.

Front 67

Peat

Back 67

formed from decaying woody plants, reeds, sedges, and mosses in watery bogs and marshlands and is usually formed in northern climates.

Front 68

Refuse-Derived Fuels

Back 68

Refuse solid fuel includes municipal solid waste (MSW) and agricultural waste.

Front 69

Proximate Analysis [ASTM D3172] -

Back 69

[ASTM D3172 in the Annual Book of ASTM Standards] determines the moisture, volatile combustible matter, fixed carbon, and ash in a fuel sample.

Front 70

Ultimate Analysis [ASTM D3176]

Back 70

[ASTM D3176 in the Annual Book of ASTM Standards] provides the major elemental composition of the fuel, usually reported on a dry, ash-free basi

Front 71

Heating Value [ASTM D5865]

Back 71

is determined in a calorimeter [ASTM D5865 in the Annual Book of ASTM Standards]. A small sample of fuel is placed in the calorimeter, which is pressurized with excess oxygen. A spark ignites the sample, and the temperature rise in a surrounding water jacket is measured.

Front 72

Hardgrove Grindability Test [ASTM D409]

Back 72

[ASTM D409 in Annual Book of ASTM Standards, Vol. 5.06] is used to determine the relative ease of pulverization of coals.

Front 73

Free Swelling Index [ASTM D720]

Back 73

[ASTM D720 in Annual Book of ASTM Standards, Vol. 5.06] is an indication of the caking characteristics of coals when burned as a fuel.

Front 74

Ash Fusion Temperature [ASTM D1857] -

Back 74

[ASTM D1857 in the Annual Book of ASTM Standards, Vol. 5.06] is determined by heating a ground fuel sample at 850°C in air and then in oxygen to ensure complete oxidation of the fuel.