Full load and part load

Full load is an operating state of a prime mover in which it provides the maximum possible torque at a given speed . If it produces a lower torque by throttling the energy supply, it is referred to as partial load .

As a rule, the point of maximum efficiency of a machine is close to its full load curve at medium or high speed. A reduction in power by reducing the speed is often more economical than by reducing the load. Since the power is often needed at a certain speed of the drive, switchable gears are used.

An oversizing of the machine increases the capital commitment and the energy consumption , with mobile use also by carrying the system (particularly critical with rocket motors ).

Partial load in motor vehicles

In particular, internal combustion engines in motor vehicles are mainly operated at partial load, since "full throttle", at least in the lower gears , would usually lead to undesired acceleration.

One way out is the hybrid drive . The electric motors used can be heavily loaded to accelerate, the correspondingly smaller combustion unit usually runs at at least half the power in the economic range.

Partial load in power plants

In the network control network , if the peak load is not required, it is beneficial to switch off power plants so that the remaining ones can be operated at higher loads. In order to be able to cover sudden electricity demand peaks, some of the power plants are operated more or less permanently at partial load, see warm reserve .

Other use

These terms are also used outside of the prime mover, e.g. B. used in heat generators in boilers . Full load describes the operating state of maximum heat generation.

literature

• Richard van Basshuysen, Fred Schäfer: Handbook Internal Combustion Engine Basics, Components, Systems, Perspectives. 3rd edition, Friedrich Vieweg & Sohn Verlag / GWV Fachverlage GmbH, Wiesbaden, 2005, ISBN 3-528-23933-6