The pumps have the function of compressing liquids. The latter being incompressible, the compression work is very simple to calculate:

The pumps can be of different types, displacement or turbo, usually centrifugal.

In terms of thermodynamics, a pump is a component similar to a compressor. Its heat exchange with the surroundings is minimal and the operation of this machine is nearly adiabatic

Under these conditions, the ideal reference process is the reversible adiabatic, i.e. the isentropic process.

To calculate the work put into play in a real pump, we introduce an adiabatic or isentropic efficiency, determined experimentally, which is defined as the ratio of the isentropic compression work to the actual compression work .

The icon of a pump in Thermoptim is the same as that of a compressor: