SINGLE-EFFECT STEAM-FIRED ABSORPTION CHILLERS
16TJ 11-53
Fast digital PID control
Graph 5 - Steam valve opening control
Variable (5-30 minutes)
The introduction of new digital PID control stabilises the
chilled water temperature with high accuracy. It quickly
responds to the load fluctuation and supplies stable chilled
water temperature. It is suitable for air-conditioning intelligent
buildings which require sophisticated control.
Example:
15 minutes
30 minutes
Balancing the load and flow rate with the absorbent pump’s
inverter control enables efficient and energy-saving operation.
As a result, it reduces input energy and electric power
consumption. Running cost is decreased by 5% compared to
non-inverter control.
Steam control valve
opening ratio
Cooling water entering temp.
Chilled water entering temp.
Setting
7 °C
Chilled water leaving temp.
COOLING
Temperature (°C)
Saving energy with the inverter
(option)
Steam consumption (%)
Steam control opening ratio (%)
Steam consumption
Graph 4 - Running cost curve
Time
(minutes)
100
■■ This ensures quick response to rapid changes and
maintains stable operation.
■■ The safe operating zone is between 19 °C and 34 °C
cooling water temperature (for a nominal cooling water
entering temperature of 32 °C).
80
Non-inverter
control
60
40
100
20
40
60
80
100
Cooling load factor (%)
Notes:
1. Chilled-water leaving temperature 7 °C constant
2. Cooling water entering temperature:
Maximum input (%)
20
0
HEATING HEATING
Graph 6 - Safe operating zone chart
Inverter
control
80
60
40
20
0
H--13
H--4
Load factor (%)
Temperature (°C)
100
32
Cooling water entering temperature (°C)
50
27
H = 32 °C (variable from 20 °C to 33 °C)
30
25
H
H+2
Crystallisation protection
Purge system
■■ The high-performance purge system maintains
the required operating pressure, preserves chiller
performance characteristics, minimises chiller
maintenance to one purge operation per season (for yearround operation).
■■ A microprocessor monitors the absorbent concentration.
Steam supply is stopped, and the unit is returned to
normal operation, when the concentration is over a
certain limit, to prevent the crystallisation of absorbent.
AIR TREATMENT
Energy consumption ratio (%)
Expansion of safe operating zone
Steam valve opening control
C
A
R
R
I
E
R
2
0
1
6
/
2
0
1
7
CONTROLS
■■ At the start-up, the opening angle of the steam control
valve is controlled in three stages, reducing the amount
of steam and the time needed to reach the desired level,
compared with the previous model.
■■ Adjusting the opening speed of the steam control valve
at the second and third stage, it is possible to set up the
most suitable conditions for the site auxiliary equipment.
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