STIEBEL ELTRON Heat pumps, Technical Manual

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Defrosting
removal of a frost or ice coating
from the evaporator of the air | water
heat pump by supplying heat.
stiebel eltron heat pumps are
defrosted on demand through the
refrigerant circuit.
Process medium
special term for refrigerant in heat
pump systems.
Dual-mode temperature
outside temperature, which dictates
when a second heat source is started.
Enthalpy
According to its definition, it is
the sum of internal energy and
displacement work. the specific
enthalpy (kJ/kg) is used for all
calculations.
Expansion appliance
Component of the heat pump between
the condenser and the evaporator for
reducing the condensation pressure to
the evaporation pressure that equates
to the evaporation temperature. in
addition the expansion valve regulates
the injection volume of the process
medium, subject to the evaporator
load.
Fill level
the mass of the process medium
inside the heat pump.
Heating output
the heating output is the available
heat produced by the heat pump.
lg p, h-diagram
Graphic representation of the thermo-
dynamic properties of process media
(enthalpy h, pressure p).
Annual performance factor
Quotient of heat and compressor drive
work over a definite period.
Annual expenditure of energy
the annual expenditure of energy
is the flip-side of the annual
performance factor.
Cooling capacity
Heat flow extracted by the heat pump
evaporator.
Refrigerant
Material with a low boiling point,
which is evaporated by heat
absorption and re-liquefied through
heat transfer in a circular process.
Circular process
Constantly repeating changes in
condition of a process medium by
adding and extracting energy in a
sealed system.
Coefficient of performance (COP)
Factor comprising the heating output
and the compressor drive rating.
the CoP can only be quoted as an
actual value at a defined operating
condition. the heating load is always
greater than the compressor drive
rating; hence the CoP is always > 1.
equation symbol: ε
Rated consumption (compressor)
the maximum power consumption
of the heat pump during constant
operation under defined conditions.
it is decisive only for the power
connection to the supply network and
is given on the manufacturer's type
plate.
Standard efficiency
Quotient derived from the used and
related expended work or heat.
Evaporator
Heat exchanger of a heat pump, in
which the thermal flow is extracted
through condensation of the heat
source process medium.
Compressor
Machine for the mechanical
transportation and compression of
vapours and gases. Differentiation
according to the type of construction.
Condenser
Heat exchanger of a heat pump where
the thermal flow is transferred to a
heat transfer medium by condensing a
process medium.
Heat pump
Machine that absorbs a thermal flow
at a low temperature (cold side) and
transfers it through energy supplied
at a higher temperature (hot side).
when using the "cold side" we refer
to refrigerators, when using the "hot
side" we refer to heat pumps.
Heat pump system
total system, comprising a heat source
and a heat pump system.
Compact heat pump system
Fully-wired appliance, where the
complete refrigerant circuit, incl.
safety and control equipment, has
been manufactured and tested.
Heat source
Medium, from which the heat pump
extracts energy.
Heat utilisation system
equipment for heat transfer to the
heating system.
Heat source system (WQA)
equipment for the extraction of
energy from a heat source and the
transportation of the heat transfer
medium between the heat source
and the "cold side" of the heat pump,
including all auxiliary equipment.
Heat transfer medium
liquid or gaseous medium (e.g. water
or air), with which heat is transported.
Auxiliary energy
energy required for the operation of
auxiliary equipment.
Off-periods
in Germany, heat pumps can be
stopped, subject to your tariff, by the
power supply utility for 3 x 2 hours
daily.
tErmInology and dEScrIptIonS