Glossary of Power Engineering Terms
E
| Term | Definition |
|---|---|
| ECCENTRIC REDUCER |
A fitting used to connect a large pipe to a smaller pipe so that one edge of both pipes is aligned. |
| ECONOMIZER |
A heat recovery device used in a boiler to transfer heat in the combustion gases to feed water. |
| EDDY CURRENT |
Currents caused by changing magnetic fields produced in armature and field cores of electrical machines that tend to interfere with the production of emf in the armature windings. |
| EFFICIENCY |
The ratio of a machine’s energy output to energy input. It may be expressed as a decimal or a percent. Efficiency equals the work output divided by the work input or the actual mechanical advantage (AMA) divided by the ideal mechanical advantage (IMA). |
| EFFLORESCENCE |
The powder or crust formed on a substance when moisture is evaporated from it. |
| EFFLUENT |
The waste product of a process that is discharged to sewer or for further treatment. |
| ELASTIC LIMIT |
The point on a stress-strain diagram where the curve starts to deviate from a straight line and after which the material will not return to its original shape. |
| ELASTICITY |
The property that allows a material to deform under a load and return to its original shape after the load is removed. |
| ELECTRIC BOILERS |
Boilers in which heat is produced by electricity rather than fuel oil or gas. Heat is produced either between two electrodes or by resistance to the flow of electricity through a coiled conductor. |
| ELECTRIC FURNACES |
Furnaces in which the air is heated by passing directly over the electric heating elements. Electric energy is converted to heat using open wire resistance heating elements. |
| ELECTRIC INFRARED HEATER |
Electric heaters consisting of long, slender tubes, similar in appearance to fluorescent lamp fixtures. The tubes fit into fixtures, which can be hung from the ceiling or wall, or mounted flush with the ceiling. A reflector is mounted behind each tube directs the radiant heat into the space to be heated. |
| ELECTRODE |
A conductor that emits or collects electrons in a cell. |
| ELECTROLYSIS |
The production of a chemical reaction by passing an electric current through an electrolyte. |
| ELECTROLYTE |
A liquid or paste that conducts electricity as a result of the presence of positive or negative ions. |
| ELECTROMAGNET |
A temporary magnet made of a ferromagnetic core wound with insulated wire through which is passed an electric current. The current flow through the windings causes a magnetic field to build that will attract magnetic material. |
| ELECTROMAGNETIC INDUCTION |
The production of electromotive force (emf) in a conductor through relative motion of a conductor and a magnetic field, or by the change in the strength of magnetic flux around the conductor. |
| ELECTROMOTIVE FORCE (EMF) |
The potential difference, expressed in volts, that is generated by a source of electric current. |
| ELECTRON |
A small subatomic particle that contains a negative electric charge and is of negligible mass. |
| ELEMENT |
A pure substance that cannot be broken down into simpler substances by chemical means. |
| EMF |
Refer to Electromotive Force. |
| EMULSION |
Where one liquid is trapped in another liquid, i.e. water and oil. |
| END PLAY |
The amount of radial movement of a shaft. |
| END POINT |
The point that a colour change occurs during titration, i.e. water testing - blue changes to clear. |
| END SUCTION CENTRIFUGAL PUMP |
The most common style of centrifugal pump, either frame-mounted or close-coupled, where the centre of the suction line is centred on the impeller eye. |
| ENERGY |
The ability to do work. Energy has the same units as work (Joules) and is convertible to many different forms such as heat, mechanical, chemical, nuclear. |
| ENTHALPY |
Heat that is comprised of the internal energy plus the work done. |
| EQUILATERAL TRIANGLE |
A triangle with three equal sides and three equal angles. |
| EQUIVALENT RESISTANCE |
A theoretical resistance that is equivalent to two or more resistances in parallel. |
| ERROR |
The difference in the amount between a measured or actual value of a variable and the desired or set point value |
| ETHYLENE GLYCOL |
A substance injected in the gas steam to prevent the freezing of the condensed liquid to prevent the formation of hydrates. |