Adiabatic Systems

Adiabatic Systems for Dry Coolers
Adiabatic air saturation and water recirculation systems to maximise dry cooler performance

Adiabatic Systems for Dry Coolers and Remote Condensers to boost thermal performance and maximise heat exchanger efficiencies.

Adiabatic systems for Dry Coolers are able to increase the relative humidity of the air passing through the exchanger, so as to decrease the temperature and increase heat exchange. This happens through the physical principle of the latent evaporation heat in which the water, by evaporating, absorbs heat from the air entering the heat exchanger, lowering its temperature.

The adiabatic saturation reduces the suction air temperature (respect to the ambient air) and therefore the efficiency of the heat exchanger increases. The adiabatic saturation temperature lowers – since evaporating water removes heat – though it is still higher than the dew temperature, as evaporation itself raises the partial pressure of water vapour. The adiabatic saturation guarantees an increase of the relative humidity up to the whole saturation of the air (R.H.=100%)

TYPES OF ADIABATIC SYSTEM

3 adiabatic systems available to guarantee maximum system efficiency for different environmental conditions and a single control system for their management.

SPRAY ADIABATIC SYSTEM

HYBRID SPRAY SYSTEM

PAD ADIABATIC SYSTEM

SPRAY ADIABATIC SYSTEM

Inlet air humidification system through water atomisation. A very thin water mist generated by specific nozzles fills and humidifies the inlet air, thus making it colder, depending on the different working conditions.

ADVANTAGES

The unit can be sized according to an air inlet design temperature that is much lower than the ambient temperature (TCALC << TAMB) (see example).
A smaller sized unit, with a smaller heat exchanger surface can be selected.
The unit can be used to cool the liquid to a temperature lower than the ambient temperature.
The Industrial Adiabatic System combined with “EC” electronic switching fans, an “Intelliboard” PLC or with a Speed controller, lowers energy consumption, Sound Emission Levels and optimizes water use.
No risk of legionella contamination.

GENERAL

Hydrophilic coating of the aluminium fins: expedites the formation of a thin film of water on the fins.
Control box (protection class IP65) factory fitted on the unit and fitted with electronic controls.
Main inlet and drain solenoid valves.
Thermostat to command the drainage of the system in the cold season.
Pressure regulator and gauge, pressure switch.
Water strainer.
SOFTWATER device to help preventing scale on the fins.
Sparge system factory fitted to the unit and made of 25mm UV resistant multilayer tubes with atomising nozzles

HYBRID SPRAY SYSTEM (H.S.S)

Water atomisation system available liquid coolers. Special diffusing nozzles spread a very thin water mist throughout the inlet air and the finned surface of the heat exchanger. The cooling capacity of the unit is considerably enhanced by the combinated effect of the adiabatic saturation of the air and the evaporation of the drops onto the fins.

ADVANTAGES

The unit can be sized according to an air inlet design temperature that is much lower than the ambient temperature (TCALC << TAMB) (see example).
A smaller sized unit, with a smaller heat exchanger surface can be selected.
The unit can be used to cool the liquid to a temperature lower than the ambient temperature.
The Industrial Adiabatic System combined with “EC” electronic switching fans, an “Intelliboard” PLC or with a Speed controller, lowers energy consumption, Sound Emission Levels and optimizes water use.
No risk of legionella contamination.

GENERAL

Hydrophilic coating of the aluminium fins: expedites the formation of a thin film of water on the fins.
Control box (protection class IP65) factory fitted on the unit and fitted with electronic controls.
Main inlet and drain solenoid valves.
Thermostat to command the drainage of the system in the cold season.
Pressure regulator and gauge, pressure switch.
Water strainer.
SOFTWATER device to help preventing scale on the fins.
Sparge system factory fitted to the unit and made of 25mm UV resistant multilayer tubes with atomising nozzles

INDUSTRIAL ADIABATIC SYSTEM (PAD)

Inlet air humidification system by means of special adiabatic panels. The panels, placed in front of the heat exchangers on the air inlet side, are homogeneously soaked through a distribution system with no water recirculation. The air, by passing through the panels, increases its humidity and gets colder depending on the different working conditions.

ADVANTAGES

The unit can be sized according to an air inlet design temperature that is much lower than the ambient temperature (TCALC << TAMB) (see example).
A smaller sized unit, with a smaller heat exchanger surface can be selected.
The unit can be used to cool the liquid to a temperature lower than the ambient temperature.
The Industrial Adiabatic System combined with “EC” electronic switching fans, an “Intelliboard” PLC or with a Speed controller, lowers energy consumption, Sound Emission Levels and optimises water use.
No risk of legionella contamination.

GENERAL

“PAD” panels used to distribute water over the unit air intake.
Mounted and wired electrical switchboard; a speed controller installed inside the unit regulates the adiabatic system.
System drainage electrovalves.
Safety thermostat for the system drainage during cold months.
Pressure reducer to regulate the necessary pressure and valves for exhaust air regulation.
Multilayer UV-resistant tubes.
Humidity probe for ambient humidity control.

SYSTEM COMPARISON

In choosing the most appropriate adiabatic system for the application it’s necessary to consider the following parameters:

Estimated annual operating hours
Percentage of increase in relative humidity obtainable
Percentage of saturation obtainable
Maximum reduction of the obtainable air temperature

The choice also leads to different consequences in terms of initial investment, subsequent operating management costs, savings in terms of electricity and water used, duration (see comparison chart).

adiabatic-system-compatison-chart-eng-scaled

SYSTEM ACCESSORIES & OPTIONS

WATER RECIRCULATION SKID

Designed to minimise water consumption in a closed-circuit adiabatic system. The water used to allow the adiabatic saturation of the air is directed into the basin and redirected into the circuit through the recirculation pump. Water consumption is thus limited to the quantity evaporated during the adiabatic process.

Submersible centrifugal pumps in stainless steel material. Enclosure class: IP 68. (Dual pump available on request).

The dimensioning of the pump size is optimized for the maximum water flow required by the adiabatic system.

Flow rate gauge with piezoelectric sensor.
Tank water level transducer.
Water conductivity meter available on request.

ULTRAVIOLET LAMP FOR ADIABATIC SYSTEM

The UV lamp sterilizes the water in the adiabatic system (UV-C rays l= 254 nm) emitting UV rays lethal to pathogens (including Legionella), providing an alternative effective solution to chemical biocides.

Unlike chemical treatments, UV sterilization does not use any harmful substances or add any toxic-noxious component to the water. The intense bio-structural disorder induced by this radiation interferes with the development and the reproductive capacity of every kind of micro-organism, making them inoffensive.

NOTE: the dimensioning of the lamp size is optimized for the maximum water flow required by the adiabatic system.

Additional recommended water quality requirements:

Fe < 0.3 ppm
Hardness <12 °f = 6.7°dH = Max. 120 ppm of CaCO3.
S.A.C. (Spectral Absorption Coefficient) > 20 1/m S.A.C. (Spectral Absorption Coefficient) > 20 1/m

ADIABATIC SYSTEM MANAGER

For the control and diagnostics of all adiabatic systems and related on-board equipment (pressure, temperature and humidity sensors, UV lamps, actuation valves).

Overview:

Complies with European Directive 2014/30/EU EMC
Enclosure in UV resistant plastic, protection rating IP54 (IEC Standard 60529).
Operating temperature -25°C +50°C
Multifunction LCD Display (resolution 128×64), remote control distance 600m
4 control buttons
Multilanguage menu
Power supply overcurrent protection using fuse
USB Host Interface allows flash drive connection to upgrade software and download data logs
Signal buzzer
Electromagnetic system for reducing limescale build-up
Non-volatile memory to retain parameters and event logs
RTC (Time/Date) with battery backup
Humidity/temperature sensor
Input: remote start/stop (clean contact or Modbus)
Output: operating state (clean contact)
Output: alarm state (clean contact)
Output: room thermostat state (clean contact)
2 password levels: user/manufacturer