Variable Flow Evaporator; Evaporator Flow Rate (L/S); Condenser Water Flow Rate (L/S); Minimum Chilled Water Loop Volume - Danfoss BW05 Installation, Operation And Maintenance Instructions

5.6 - Evaporator flow rate (l/s)
BW05 Minimum Maximum flow rate*
flow rate Single pump
020 0.3 1.7
025 0.4 2.5
030 0.5 2.5
040 0.7 3.4
045 0.8 3.8
060 0.9 5.7
070 1.2 6.2
080 1.4 6.4
090 1.5 6.6
110 1.8 8.3
120 2.2 8.5
135 2.4 8.8
150 2.7 9.0
160 2.7 14.2
185 3.1 14.5
210 3.8 17.4
245 4.4 17.4
275 5.0 18.1
300 5.5 18.1
* Maximum flow rate for an available pressure of 50 kPa (unit with hydronic module)
** Maximum flow rate for a pressure drop of 100 kPa in the plate heat exchanger (unit
without hydronic module)
5.7 - Condenser water flow rate (l/s)
BW05 Minimum flow rate* Nom. condenser
at min. condenser flow rate at Eurovent
capacity conditions
t = 10 K
020 0.5 1.2
025 0.7 1.5
030 0.8 1.7
040 1.0 2.3
045 1.2 2.7
060 1.4 3.3
070 1.8 4.1
080 2.1 4.7
090 2.3 5.4
110 2.8 6.4
120 3.3 7.3
135 3.6 8.3
150 4.0 9.1
160 4.2 9.4
185 4.7 10.8
210 5.7 12.7
245 6.5 14.5
275 7.3 16.6
300 8.0 18.2
* The minimum flow rate given is for units without hydronic module that have a
fixed condenser flow rate.
Units with a hydronic module have a variable flow rate and no minimum fixed flow
rate.
The minimum flow rate is optimised by unit control in parallel with the drycooler
fan stages for all operating conditions, especially at low outdoor temperature and
low load conditions.
** The maximum flow rate given is for units without hydronic module that have a
fixed condenser flow rate.
Units with a hydronic module have a variable flow rate.
The maximum flow rate is optimised by unit control at all operating conditions,
based on pump capacity, system pressure losses and outdoor temperature.

5.8 - Minimum chilled water loop volume

Whichever the system, the water loop minimum capacity is
given by the formula:
Capacity = Cap (kW) x N Liters
Where Cap is the nominal system cooling capacity (kW) at
the nominal operating conditions of the installation.
This volume is necessary for stable operation and accurate
temperature control.
Application
Air conditioning
BW05 020-045
BW05 060-300
VUGFB102
Maximum
Dual pump flow rate**
- 1.7
- 3.1
- 3.1
- 3.7
- 4.7
5.6 5.9
6.1 7.3
6.2 8.0
6.3 8.4
11.7 10.3
12.4 11.4
13.1 12.8
13.7 14.3
14.2 15.9
14.5 17.0
22.0 24.0
22.0 24.0
23.3 29.1
23.3 29.1
Maximum flow rate**
at max. condenser
capacity
t = 5 K
1.4
1.8
2.0
2.7
3.1
3.8
4.8
5.5
6.2
7.4
8.5
9.5
10.3
10.9
12.5
14.6
16.8
19.0
20.5
N
3.5
2.5
Industrial process applications
Certain industrial processes may require high leaving water
stability. In these cases the values above must be increased.
It may be necessary to add a buffer water tank to the circuit in
order to achieve the required volume. The tank must itself be
internally baffled in order to ensure proper mixing of the
liquid (water or brine). Refer to the examples below.
Bad
Bad
5.9 - Maximum water loop volume (evaporator and
condenser side)
Units with hydronic module incorporate an expansion tank
sized for the maximum water loop volume.
The table below gives the maximum water loop volume (in
litres) for pure water or ethylene glycol with various con-
centrations.
BW05 020-045
Pure water 673
10% ethylene glycol 487
20% ethylene glycol 358
35% ethylene glycol 290

5.10 - Minimum hot water loop volume

The condenser water loop volume has no impact on the chiller
operation. For heat pump operation (unit control based on the
hot-water temperature) the minimum condenser water loop
volume must be calculated in accordance with the method
used for the evaporator loop, replacing the cooling capacity
with the heating capacity.
Good
Good
060-080 090-150 160-210 245-300
1000 2080 2900 4162
730 1525 2135 3053
540 1120 1570 2236
430 910 1260 1800
15