Installation manual

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Water-to-Water Heat Pump 4.1
4 Water-to-Water Heat Pump
4.1 Ground Water as Heat Source
Temperature range of the ground water 7 to 12 ° C
Operating range of the water-to-water heat pump 7 to 25 °C
Availability
 Year round
Types of operation
 Monovalent
 Mono energy
 Bivalent mode (alternative, parallel)
 Bivalent-renewable mode
Development costs
 Approval process (local water authority)
 Extraction wells / absorption wells with air-tight
sealing of the wellheads
 Water quality (water analysis)
 Pipework
 Well pump
 Excavation/construction work
Tapping the ground water heat source
Starting at a well depth of between 8 to 10m, the ground water
heat source is suitable for monovalent heat pump operation, as it
is only susceptible to minor temperature fluctuations throughout
the year (7-12°C). Approval is required from the appropriate
water authorities for heat extraction from ground water.
Permission is generally given outside of water protection zones.
However, permission is dependent on certain conditions, e.g. a
specified maximum amount of water that may be withdrawn, or a
water analysis. The amount of water that may be withdrawn
depends on the heat output. Table 4.1 on p. 127 lists the
necessary withdrawal quantities for the operating point W10/
W35.
A well system with extraction and absorption wells should be
designed and constructed by a drilling company accredited with
the seal of approval from the International Heat Pump
Association or authorised according to DVGW W120. The
information in the Association of German Engineers' (VDI)
publication VDI4640 Parts 1 and 2 should be taken into
consideration.
NOTE
Two wells are required for the withdrawal of ground water, an “extraction
well” and an “absorption well”. For economic reasons, for heat pumps
with a heat output of up to 30 kW, ground water should not be pumped
from depths greater than approx.15 m.
Table 4.1: Dimensioning table of the minimum well pump specifications required for water-to-water heat pumps at W10/W35 for standard installation set-ups with
sealed wells. The final specifications of the well pump must be agreed upon in consultation with the well constructor.
NOTE
The overcurrent relays integrated in the heat pumps must be set during
installation.
Heat Pump
Well pump
(recommended for
standard installation
set-up)
Circulating pump for use
if the quality of the water
is poor and an
intermediate circuit with
plate heat exchanger
is used
Well pump compression
Cold water flow of HP
Heat output of
the heat pump
Refrigerating capacity
of the heat pump
Pressure drop of
the evaporator
Well diameter from
Motor prot.
Bar
m
3
/h
kW kW Pa Inch A
WI 9ME Grundfos SP 2A-6
Not required
1
1. Stainless steel coil heat exchanger as standard!
2.4 at 2 8.3 6.7 6200 4" 4
WI 9TE Grundfos SP 2A-6
Not required
1
2.4 at 2 8.3 6.7 6200 4" 1,4
WI 14ME Grundfos SP 3A-6
Not required
1
2.3 at 3.3 13.6 10.9 19000 4" 4
WI 14TE Grundfos SP 3A-6
Not required
1
2.3 at 3.3 13.6 11 19000 4" 1.4
WI 18TE Grundfos SP 5A-4
Not required
1
1.8 at 4.0 17.1 13.9 12000 4“ 1.4
WI 22TE Grundfos SP 5A-4
Not required
1
1.6 at 5 21.5 17.6 20000 4" 1.4
WI 27TE Grundfos SP 8A-5
Not required
1
2.2 at 7 26.4 21.3 16000 4" 2.3
WI 40CG Grundfos SP 8A-5
Wilo Top-S 40/7
2
2. Control via M11 output (primary pump) on HPM
1.7 at 9.5 44 36.3 17500 4" 2.3
WI 90CG Grundfos SP 17-2
Wilo Top-S 50/7
2
1.1 at 20 92 75 19000 6" 3.4
WI 90CG Grundfos SP 17-3
Wilo Top-S 50/7
2
1.8 at 20 92 75 19000 6“
5.5
3
3. Standard protective motor switch must be replaced!