Industrial processes often work with fluids of different kinds that need to be cooled. A free cooler, also known as a dry cooler, is an industrial thermoregulation system that allows a fluid’s temperature, heated from a manufacturing process, to be lowered, simply employing ambient air, without using chillers or other refrigerating systems that require higher amounts of energy consumption. A free cooler can be an excellent cost-effective alternative to industrial chillers.
A free cooler is a thermoregulating system that relies on outdoor air to cool down fluids heated by industrial processes. These are heat exchangers and dissipators with forced air circulation, with electric fans that blow in outdoor air to cool fluids, and their design depends strictly upon the type of liquid to be cooled and its inlet temperature, ambient average ambient air temperature, capacity, liquid outlet temperature and maximum allowed pressure drop. These kind of cooling systems have a wide range of application fields, such as:
- Power generation
- Cogeneration
- Air compressor cooling
- Engine cooling
- Remote dissipator
- Emergency cooling electroradiators
- Coolers
- Radiators for engine
- Gen set dissipators
Depending on external air, free cooler performance is related to climatical conditions and geographical factors and, most of all, this kind of cooling system can be affected by seasonal variations of outside ambient air temperature. But there is a smart method that allows free cooler efficiency to be improved, extending its use even in months where challenging temperatures occur, allowing their efficient use both in winter and summer months. Indeed, in order to obtain maximum cooling capacity from a free cooler, external air must have a temperature as low as possible, so that inlet air can succesfully be used in the cooling cycle of the industrial thermoregulation system.
T Fin IDry Cooler systems by Tempco are water spray modules that can lower ambient air temperature by moistening it by spraying water particles on suction air. Evaporation of the sprayed water draws heat from ambient air, lowering its temperature, so that it can be normally employed in the thermoregulation cycle achieved by the free cooling system. This kind of solution is a thermal booster that increases efficiency of free coolers using the same evaporation thermal process that works on evaporative towers, coupling their advantages to the ones of a free cooler dissipator, working on latent heat evaporation, and also wet bulb temperature.
Enhancing a free cooler with a thermal booster water spray module, the aerorefrigerating system obtains advantages both from dissipators and evaporative towers.
A dry cooler system guarantee:
- Closed circuit fluids
- No scaling
- No chemicals
- Low operating costs
Additionally, a water spray system using evaporation to lower inlet air temperature gives advantages of an evaporative tower:
- Forced cooling
- Low energy
- Water temperature lower then ambient
Air is indeed cooled by water evaporation, and so this kind of boosted industrial thermoregulation system relies on air temperature and its humidity, working on wet bulb temperature and latent heat of evaporation.
Latent heat of evaporation is the heat amount drawn from air to evaporate water, while wet bulb temperature is the lowest temperature that can be reached by the evaporation of water only.
The evaporating rate strictly depends on outdoor air conditions, such as the original heat content of the air, called dry bulb temperature, and the vapor saturation level of ambient air, called relative humidity, or dew point. Wet bulb temperature is a function of humidity and ambient air temperature, and it measures the amount of water vapor that atmosphere can hold, at a certain weather condition.
Obviously, wet bulb temperature is higher in summer, when air temperature and humidity raise, and depending on geographical area where the free cooling system is supposed to work, a plant’s performance can vary very much due to variations of weather conditions and wet bulb temperature values. Tempco offers measurement tools to estimate wet bulb temperature, designing the best free cooling solution for the area and climatical conditions of the industrial plant. Wet bulb temperature is calculated using dry bulb temperature and dew point (subtract dew point from dry bulb temperature, and divide it by three, than subtract the result from dry bulb temperature). Visit Tempco’s website for an easy tool to estimate it.
Those T Fin IDry systems by Tempco are easy to install, and can be enhanced on pre-existing free cooler equipment simply as a retrofit module, enhancing cooling process. The thermal water spray booster system can be shut down when the hot season ends, so that it can be used only when weather conditions require it, not affecting the usual thermal cycle of the cooling solution. Water feeding the system must be clean, not to leave deposits on the system components, causing fouling and damage on the dissipator, and so water must be properly treated. Also, care must be taken that no obstructions occur short circuiting the outdoor air flow, such as walls or others.
Tempco service fully provides study for free cooling plants’ empowering, allowing industries to use it under any weather/climatic temperature conditions, always achieving the best results from an industrial thermoregulation system and higly reliable operations. Tempco service also offers complete water treatments.
For other information on enhancing and increasing free cooler performance, visit Tempco’s website.