Recently we read an article in “”, which given their interest transcribed.…EVAPORATIVE REFRIGERATION: ENERGY EFFICIENCY AND ENVIRONMENTAL SECURITY

The evaporative cooling applied in the condensation of refrigeration equipment (air conditioning, refrigeration, etc …) is a safe and efficient alternative. New technologies that apply to this principle have multiplied the cooling capacity of refrigeration equipment, while ensuring both energy efficiency and environmental safety.

Evaporative cooling is a natural process that uses water as a refrigerant, a medium that has been proven effective in the dissipation of surplus heat to the atmosphere. This is the principle of operation on which evaporative water cooling equipment is based, such as evaporative towers and condensers, as a means for cooling or condensing fluids (in the case of the refrigerant fluid of the refrigerating machine) in numerous applications.

Consequently, these equipments constitute one of the most efficient alternatives in the field of industrial refrigeration. They use a technology that respects the environment, require an investment lower than that demanded by similar solutions and are safe for human health.

During the process of refrigerating a fluid, these systems release to the atmosphere the heat extracted to the fluid through, fundamentally, the evaporation of water. This process is achieved thanks to the establishment of a close contact between the circulating water and a small air stream, so that by evaporating a minimum part of water, most of the heat is transferred to the air, which is discharged to the air. the hottest and most saturated atmosphere. The concept of evaporative heat evacuation systems is simple: the contact of hot water with cold air causes a transfer of heat and mass which results in the cooling of the water used as cooling medium in multiple industrial processes.

The fields of application of the evaporative cooling equipment are mainly two: cooling of water for industrial uses and cooling of the condensation water of refrigeration installations, which can be air conditioning installations or refrigeration installations (industrial, commercial, hospitality, … ).

This means hundreds of thousands of companies that depend on evaporative cooling to carry out their industrial processes. Special mention deserves the food industry, in which industrial refrigeration uses approximately two thirds of its facilities. The conservation of food is longer as soon as possible to reduce its temperature to optimal levels of storage. The conservation of all meat and fish, fruits and vegetables, dairy products, etc. it is ensured by means of low temperatures.

On the other hand, industrial air conditioning is another application of refrigeration that, unlike air conditioning in office or residential buildings, is carried out to achieve adequate environmental conditions for the products in the rooms where they are processed, handled and they pack. Industrial air conditioning is characterized mainly by the state of the air supplied, defined by the level of temperature, precisely controlled humidity, stricter filtering and previous removal of contaminants that provide optimal hydrothermal and sanitary conditions for the processing of products.

Latest technological advances

Basically, there are two types of cooling towers: open circuit and closed circuit, there are also hybrid variants of both. The first ones present the advantages of supposing a low initial investment, having little weight and offering very efficient evaporative cooling results. Regarding its disadvantage, we can say that the fluid to be cooled has contact with the outside air and, therefore, is susceptible to being contaminated with dirt.

The closed circuit towers, meanwhile, have two water circuits and despite being more expensive, heavy and losing some efficiency, they manage to keep the primary circuit closed, clean and free of contamination and, in addition, minerals, dust , the impurities and bacteria in the air, dragged by the water, are concentrated only in the equipment raft, where they can be easily eliminated.

As much in some as in others, in the last years a considerable technological advance has been experimented destined, on the one hand, to improve the efficiency of the equipment and, on the other hand, to reduce the risk that these can be transmitters of Legionella. This is so to the point that, nowadays, only poor maintenance is likely to generate this problem. Among the technical advances that we can highlight are the combined action air filters against UV rays, dirt and water splashes and separators or droplet eliminators. Both contribute in a radical way to meet the aforementioned objectives.

In this sense, the cooling towers and evaporative condensation equipment are not manufactured with cellulose-based materials, but with materials resistant to the aggressive action of water, chlorine or other disinfectants in order to avoid corrosion phenomena. The interior surfaces are smooth, the closing panels are removable to facilitate the cleaning of the filling and they have continuous dosing systems for biocides.

Of vital importance is also the treatment of water in these equipment. Inlays and lack of cleaning reduce system performance, increase operating costs and favor bacteriological contamination. By way of example, it should be mentioned that the effects produced by 1 mm of incrustation in the battery of a closed circuit tower supposes a 30% loss of heat transfer, 6 ° C of increase of condensation temperature and 18% more than compressor consumption kWh.

The water treatment must be defined according to the quality of the water supply, the constructive characteristics of the equipment and the operating conditions of the equipment. In any case, the water treatment of a cooling tower basically consists of a pre-treatment with decalcifiers and reverse osmosis; chemical treatments that include inhibitors of corrosion, antifouling and biocides and, finally, physical treatments.

More advantages: energy saving and respect for the environment

Another great concern of the industry and of society as a whole lies in caring for the environment. In this sense, refrigeration and evaporative condensation equipment provide a resounding response to industrial sustainability in terms of, on the one hand, saving energy and, on the other, respecting the environment.

In terms of energy savings, in the air conditioning and refrigeration installations, energy efficiency and electric power consumption are directly related to the condensing temperature of the refrigerant used in the refrigeration system. In a typical air conditioning installation, the comparison of energy consumption shows illustrative figures: water condensation equipment, including cooling towers and evaporative condensers, would offer, compared to air condensation, savings in consumption of up to 45%. %. Another example in the same line would be the one produced in the refrigeration facilities, where the powers absorbed, when the condensation of the refrigerant is made by water cooled by evaporative towers and condensers versus when it is made by air, are significantly lower.

Regarding the environment, the evaporative cooling used in refrigeration and air-conditioning systems with water condensation is a technology that respects the environment and produces a reduced environmental impact in several aspects.

Reduction of the greenhouse effect

This technique has proven to be the most effective technology to combat the greenhouse effect, by limiting indirect CO2 emissions thanks to the consumption of electrical energy consumed and direct due to the lower risk of leakage of refrigerant gases when working refrigeration facilities with relatively high pressures reduced. This decrease in energy consumption and gas leakage is achieved for the following reasons

. Efficiency of the process: the greater the efficiency of the industrial process, the lower the amount of energy that is lost and the easier it is to get rid of the residual heat. Many processes are sensitive to temperature and need cooling, therefore, to ensure maximum performance it is important to have a highly efficient cooling technology.

. Acoustic impact: apart from the reduction of the greenhouse effect, among other environmental factors to be taken into account, there is noise pollution. This is reduced in the case of evaporative cooling equipment, because they require a lower air flow rate than air-cooled equipment.

Reduction of water consumption:

Regarding water losses, in the place of application, the evaporative cooling reuses more than 95% of the water that it mobilizes in its operation. A small amount evaporates and another is evacuated to avoid the concentration of salts. For example, if we have a thermal power plant with a 33 percent efficiency, for 1 kW / h generated electricity we would have to dissipate 2.03 kW / h thermal. If we do it through an evaporative cooling system, we would dissipate 3.17 l / h by evaporation, plus 1,585 l / h through the purges.


When drawing conclusions, one wonders why evaporative cooling versus alternatives such as air cooling. The reasons are as follows:

. Better energy balance: the decrease of 1ºC in the condensation temperature represents a 2% -3% saving in electrical energy in the compression work.

. Less installed electrical power

. Lower peak demand (kW).

. Lower consumption (kWh).

. Lower initial investment

. Lower cost of the electrical installation.

. Less occupied space

. Lower floor area.

. Lower investment in soundproofing.

. More respectful with the Environment

. Less need for electricity production (lower consumption of electricity).

. Less need for transport electric lines and lower losses in such transport.

. Lower CO2 emission (55% lower than air equipment).

. Lower sound level.

. Less vibrations

Control and Ventilation, S.L. is a company of international renown within the industrial and livestock sector, for being a manufacturer of products within the evaporative cooling sector, such as the HUMIBAT, evaporative plastic cooler; or its NUCLEOS towers, Cooling Towers. In both products, which the substrate in which the evaporative is produced is a plastic honeycomb, a honeycomb resistant to both physical and chemical attacks, and at the same time flexible, is a honeycomb with mesh structure, manufactured in High Density Polyethylene , and marketed under the names of PANAL C & V or if it is a separator of drops, SEPARATOR C & V.

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