Technical data

9Operating Manual geoTHERM exclusive VWS 0020071929_00
4 Equipment and functional
description
4.1 Principle of operation
Heat pump systems consist of separate circuits in which
liquids or gases transport the heat from the heat source
to the heating system. As these circuits operate with
differing media (brine/water, coolant and heating
water), they are coupled to one another by means of
heat exchangers. In these heat exchangers the heat
passes from a medium at a high temperature to a medi-
um at a lower temperature.
The Vaillant geoTHERM exclusive heat pump uses geo-
thermal energy as its heat source.
3/4 Environmental energy 4/4 Heating energy
1/4 Electrical energy
Fig. 4.1 Using a geothermal heat source
The system consists of separate circuits which are cou-
pled to one another by means of heat exchangers.
These circuits are:
- The heat source circuit, by means of which the energy
from the heat source is transported to the coolant cir-
cuit.
- The coolant circuit, which releases its heat to the
heating water circuit by means of evaporation, com-
pression, liquefaction and expansion.
- The heating water circuit, which supplies the heating
and the hot water generator for the domestic hot
water cylinder.
4.2 Mode of operation of the coolant circuit
Auxiliary
heating
Domestic hot water cylinder
Heating water circuit
Heat source circuit
Coolant circuit
Hot water
Cold water
Umschaltventil
Heizkreispumpe
Condenser
Heat source
Brine pump
Evaporator
Compressor
Expansion valve
2
1
3
4
Heating
system
Cooling heat exchanger
Mixer valve
Diverter valve
Fig. 4.2 Operating principle of the heat pump
The coolant circuit is connected by means of the evapo-
rator (1) to the environmental heat source, from which it
extracts thermal energy. At the same time, the physical
state of the coolant changes; it evaporates. The coolant
circuit is connected by means of the condenser (3) to
the heating system, to which it releases the heat again.
In so doing, the coolant becomes liquid again; it con-
denses.
As thermal energy can only pass from a body at a high-
er temperature to a body at a lower temperature, the
coolant in the evaporator must have a lower tempera-
ture than the environmental heat source. On the other
hand, the temperature of the coolant in the condenser
must be higher than that of the heating water in order
to be able to release the heat to it.
Equipment and functional description 4