- are needed to reduce the energy consumption of powerful cooling
systems.
It is thanks to such installations that it is possible to substantially reduce
the operating costs of cooling and improve the quality of production as a
whole.
Industrial processes require large volumes of cold water, the temperature of
which must remain stable for a long time.
In such cases, you can use free coolers (dry cooling towers).
Free Coolers or Dry Coolers These are water-to-air heat exchangers
that provide cooling of water by means of ambient air passing through the
plates of the heat exchanger with the help of axial fans. At the same
time, energy consumption is significantly lower compared to compressor
coolers. Therefore, in those processes where possible, free coolers are
used instead of compressor-based chillers, which leads to a reduction in
running costs.
Free-coolers have a huge cooling potential in the cold season, and therefore
they are widely used in energy-efficient centralized cooling systems.
Full energy savings
When the required water temperature is always above the ambient temperature,
the free cooler can operate year-round, providing greater energy savings
compared to water chillers.
Partial energy savings
When the required water temperature is below ambient temperature (in summer),
the freecooler must be used in conjunction with a water chiller. In this
case, energy savings are possible only in cold weather, and depend on the
geographical location and the required water temperature.
Energy Saving Calculation An energy saving
estimate is possible when the annual ambient temperature values (for a
specific geographic area) and the number of hours of operation per year are
known. Based on the specific temperature of the working water and working
time during the year, it is possible to calculate the energy consumption, the
comparative costs for the free cooler and the water chiller.
These calculations provide a very reliable basis for evaluating the payback of
equipment.
Example No. 1 refers to the systems shown
in Figures 1 and 3 below.
Cooling of one circuit is
required . Required cooling capacity: 200
kW
Water temperature: 15 ° C
Region: Moscow region
Average duty cycle of free cooler per circuit (cold): 67% time
Energy saving: 256 850 kWh or 65%
Example No. 2 refers to the system shown in Figure 2.
It is necessary to cool two
LTC circuits (low-temperature circuit) - the required cooling
capacity is 80 kW at a water temperature of 15 ° C
HTC (high -temperature circuit) - tr refrigerating capacity 120 kW at
water temperature 33 ° C
Region: Kyiv region
The freecooler cycle for the HTC circuit is 100% of the time.
Energy saving: 300,000 kWh per year, or 76%.
As a result, the energy-saving cooling system pays off for a period of two to
five years, depending on the specifics of the production.
As a rule, any existing cooling system can be equipped with additional
equipment to ensure the advantages of energy-saving systems.
Cooling TPA single-circuit scheme
The system has one circuit for cooling hydraulic drives and molds
TPA.
Applicable with water temperature limitations for hydraulics cooling 20-25 °
C
Figure 1.1
|
Figure 1.2
|
"Summer" - normal operation: Compressor cooler - on, cooling circuit Dry cooler - off Three-way valve - dry cooler is excluded from the circuit |
"Winter" - energy saving mode of
operation: Compressor cooler - pump on, compressors off Dry cooler - on, circuit cooling Three-way valve - dry cooler included in the circuit |
Figure 2.1
|
Figure 2.2
|
"Summer" - normal operation mode: Compressor cooler: switched on cooling of the mold circuit Dry cooler: switched on for cooling of the hydraulic circuit Three-way valve: the circuits are separated |
"Winter" - energy-saving operation
mode: Compressor cooler: pump on, compressors off Dry cooler: switched on for cooling of both circuits Three-way valve: the circuits are combined |
Figure 3.1.
|
Figure 3.2
|
"Summer" - normal operating mode: Compressor cooler - switched on, circuit cooling Dry cooler - off ТТрехходовой клапан - dry cooler is excluded from the circuit |
"Winter" - energy saving mode of
operation: Compressor cooler - pump on, compressors off Dry cooler - on, circuit cooling Three-way valve - dry cooler included in the circuit |