Glossary


C

Calorific value

Measurement of the energy contained in gas. The calorific value depends on the chemical composition. The chemical composition varies according to the source of the gas and the mixing within the gas distribution networks. Depending on the calorific value, the terms generally used are  L gas and H gas

CEN

The Comité Européen de Normalisation / European Committee for Standardization / Europäisches Komitee für Normung (CEN) is responsible for European standards (Europäische Normen, short EN) in virtually all technical areas. GASCADE is a member of CEN working groups.

Capacity

Maximum hourly flow rate at an entry or exit point in kWh/h.

Capacity booking

Maximum hourly flow rate at an entry point or exit point within a specific period. It is expressed in cubic meters per hour or kilowatt hours per hour.

Capacity model

A statistical and fluid mechanics calculation procedure which is used to determine marketable capacities.

Compensation measures

If the natural environment and the landscape are impaired as a result of a new pipeline or facility being built, the builder must pay compensation to make up for impairments.

Construction plan

A drawing like this serves as a basis for producing parts for a new facility, for example.

Control energy

Energy quantities for physically balancing (system stability) the gas networks in a market area. A distinction is made between internal control energy through the use of network buffering (line pack) and external control energy. External control energy is bought on a market basis at natural gas trading points (exchanges, Virtual Trading Point, control energy portals of the Market Area Managers) and on the basis of calculations of the transmission system operators (TSOs) in the market area and the Market Area Manager.

Compressor station (compressor)

A system that compresses natural gas to the pressure needed to reach the exit point (with contractually defined pressure values) or the next compressor station. A compressor station can comprise a number of compressor units. Each compressor unit is made up of a drive unit (gas turbine or electric motor) and the actual compressor. A compressor system also has other auxiliary systems, e.g. electrical energy supply, process management system, field instrumentation, pipelines, valves, building infrastructure, drive energy preparation, fire and gas warning system, building protection, safety systems and fire extinguishing systems.

Compressing the gas reduces its volume. This means that more gas can flow through the pipeline and the transport capacity of the pipeline is increased. The gas flow is controlled on the basis of different pressures. When gas is transported, it flows because of the differences in pressure – from high pressure to low pressure.