2　Terms

2.0.1　Identification system

A code system used to label the systems,equipment and components thereof in the power plant according to their characteristics including functions,processes,and installation positions.

2.0.2　Power system

A system consisting of power generating,power supply（power transmission,transformation and distribution）,and power consumption facilities and the facilities intended to ensure their normal operation,such as relay protection and automatic safety devices,metering devices,power communication facilities,and automation facilities.

2.0.3　Black start

In the event that a power system fails due to faults,the units in the system capable of self-starting can start to drive the units in the system that are unable to start on their own,thereby gradually restoring the operation of the system.

2.0.4　Plant area

The area permanently occupied by the production,auxiliary and ancillary facilities of a fossil power plant which are enclosed by boundary walls.

2.0.5　Main power area

The area surrounded by the centerlines of the roads around the turbine house,deaerator bay,coal bunker bay,boiler house,precipitator,chimney,and desulphurization equipment.

2.0.6　Balance of cut and fill of earthwork in plant

Excavation and filling quantity in the plant area are finally balanced through the use of excavation and filling within the plant area and the construction areas closely related to it,residual earthwork of building（structure）foundations,cultivated soil,silt or construction wastes not suitable for fills while taking into consideration other influencing factors such as bulk factor.

2.0.7　Source of danger and risk

Root causes or status that may potentially lead to injury or illness,property loss,destroy of working environment,or a combination thereof.

2.0.8　Overtopping

Unit discharge along the embankment length when waves override the embankment top.

2.0.9　Permissive overtopping discharge

Unit discharge allowed to override the embankment top under the design conditions.

2.0.10　Drought exponent

The ratio of annual evaporation capacity to annual rainfall in a region.

2.0.11　Flue gas discharged cooling tower

Cooling tower used in lieu of the chimney to exhaust the desulphurized flue gas.

2.0.12　Seawater cooling tower

Wet cooling tower where seawater is used as the cooling medium.

2.0.13　Air cooled heat exchanger

Heat release equipment which uses air as the cooling medium to cool the circulating water in the indirect air cooling system.

2.0.14　Air cooled condenser

An equipment that uses air as the cooling medium to directly condense the steam exhausted from the turbine into water.

2.0.15　Electrodeionization

A deionization technology by which electrical energy is used to remove ions contained in water by means of a combination of electric dialysis and ion exchange.

2.0.16　Supervisory information system for plant level（SIS）

The monitoring and management information system which serves to provide real-time comprehensive optimized services for the entire plant by using the plant-wide production process real-time/historical database as the platform,through collecting the real-time production data of various control systems of a fossil fired power plant.

2.0.17　Real-time system

A system that can identify and handle discrete events in limited time,and can reflect the changes in parameters of the production process on a dynamic and real-time basis.

2.0.18　Central control room

An area used to control two and more generating units and the auxiliary systems in a centralized way.

2.0.19　Unit control room

A control room used to control the boiler,turbine,generator,and the main auxiliary systems or equipment of a generating unit.

2.0.20　High voltage switchgear

A general term of the 35kV and above switchgears of fossil fired power plant.

2.0.21　One-and-a-half breaker configuration

Namely,a11/2breaker scheme.Double busbar substation where,for two circuits,three circuit-breakers are connected in series between the two busbars,the circuits being respectively on each side of the central circuit-breaker.

2.0.22　One-and-one-third breaker configuration

Double busbar substation where,for three circuits,four circuit-breakers are connected in series between the two busbars,the three circuits being respectively on each side of and between the central two circuit-breakers.

2.0.23　Control with strong power source

The control mode with rated control voltage of 110V or above.

2.0.24　Supporting structure of air cooled condenser

A general term of structures for supporting the air-cooling condenser,consisting of columns,platforms（including beams or girders used for supporting fans,maintenance platform or boardwalk）,and wind-break walls.

2.0.25　Circular closed coal yard

A large-diameter circular indoor coal storage yard structured with coal retaining wall and hemispherical net braces.