Functional Principle - Vaillant geoTHERM VWS Installation Instructions Manual

2 Description of the appliance
2.2

Functional principle

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 heat pump uses geothermal en-
ergy as its heat source.
Fig. 2.2 Utilisation of heat sources such as geothermal energy
or ground water
6
1/4 Electrical energy
3/4 Environmental energy 4/4 Heating energy
Cold water
Heating system
Additional
heating
Switching valve
Heating water pump
3
Condenser
Expansion valve
4
Evaporator
Brine pump
Heat source
Fig. 2.3 Mode of operation of the heat pump
The system consists of separate circuits which are coup-
led 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 hea-
ting water circuit by means of evaporation, compressi-
on, liquefaction and expansion.
- The heating water circuit, which supplies the heating
and the hot water generation for the domestic hot
water cylinder.
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.
Installation instructions geoTHERM VWS 0020046310_01
Hot water
Domestic
hot water cylinder
Heating water circuit
2
Coolant circuit
Compressor
1
Heat source circuit