Application Data; Operating Limits Bw05; Operating Range Bw05; Minimum Chilled Water Flow - Danfoss BW05 Installation, Operation And Maintenance Instructions

5 APPLICATION DATA

5.1 - Operating limits BW05

BW05 Entering water temperature,
°C
Evaporateur Minimum
At start-up 7.5
At shut-down -
During operation 5 (note 1)
BW05
Condenser
With hydronic module and variable-speed
pump
At start-up/during operation (minimum)
During operation (maximum)
Without hydronic module
At start-up/during operation (minimum)
During operation (maximum)
BW05 Drycooler
With hydronic module and variable-speed pump
At start-up/during operation (minimum)
During operation (maximum)
Without hydronic module
At start-up/during operation (minimum)
During operation (maximum)
Notes
1 BW05 units can operate from 4°C to 0°C without modification.
In all cases the units must be configured for low leaving-water temperature, and
use of antifreeze is required.
2 BW05 units without hydronic module operating below 20°C entering condenser
water temperature require the use of a three-way valve controlled from the 0-10 V
analogue output of the control system.
3 For a flow rate corresponding to a condenser ∆t of 5 K.
4 The maximum entering air temperature is based on the drycooler selection.
5 The minimum entering air temperature range is between 15 and 20°C (without the
use of three-way valves)
Operation at -15°C ambient temperature is possible with the use of a three-way
valve to maintain the required minimum condensing temperature (see note 2).
6 The maximum entering air temperature is based on the remote condenser
selection.
IMPORTANT: Maximum ambient temperatures. For storage
and transport of BW05 units the minimum and maximum
temperatures must not go beyond -20°C and 50°C. It is
recommended that these temperatures are used for
transport by container.

5.2 - Operating range BW05

52
50
45
40
C
35
30
25
20
-10 -5
Evaporator leaving water temperature, °C
14
Leaving water temperature,
°C
Maximum Minimum Maximum
30 5 (Note 1) 15
50 - 50
15 50 50
Entering water Leaving water
temperature, °C temperature, °C
-15 -
47 (note 3) 52
20 (note 2) 25
47 (note 3) 52
Entering air temperature, °C
-20
(note 4)
(note 5)
(note 4)
B A
0 10 15
5
45
40
35
30
25
20
15
10
5
0
-5
-10
-15
-20
-5
-10
Evaporator leaving water temperature, °C
Notes BW05
1 Evaporator and condenser T = 5 K
2 For BW05 units without hydronic module with an entering condenser water
temperature below 20°C a three-way valve is required to allow operation, while
maintaining the correct condensing temperature.
3 For BW05 units equipped with a hydronic module the minimum entering water
temperature is -15°C.
4 Maximum leaving condenser water temperature is 52°C (at full load)
A Standard unit with without antifreeze solution
B Standard unit operation with the anti-freeze solution required and control
configuration for a leaving water temperature down to 0°C.
C Standard unit operation with the anti-freeze solution required and control
configuration for a leaving water temperature down to -10°C.
D Operation at high air temperature is based on the drycooler selected.
E Operation at low air temperature is possible down to -20°C with a drycooler.
5.3 - Minimum chilled water flow
If the system water flow rate is lower than the minimum
water flow rate, recirculation of the evaporator flow may
occur. The temperature of the mixture leaving the evaporator
must never be less than 2.8 K lower than the chilled water
entering temperature.
5.4 - Maximum chilled water flow
The maximum chilled water flow is limited by the maximum
permitted pressure drop in the evaporator. It is provided in
the table below. If the flow exceeds the maximum value, two
solutions are possible:
• Modify the flow rate with the control valve.
• Bypass the evaporator to obtain a highter temperature
difference with a lower evaporator flow rate.
5.5 - Variable flow evaporator
Variable evaporator flow can be used in standard chillers. The
chillers maintain a constant leaving water temperature under
all flow conditions. For this to happen, the minimum flow
rate must be higher than the minimum flow given in the
table of permissible flow rates and must not vary by more
than 10% per minute.
If the flow rate changes more rapidly, the system should
contain a minimum of 6.5 litres of water per kW instead of
the values below
D
E
0 10 15
5
VUGFB102