Design and application of wet curtain cooling system


2023-02-18 11:05


Fan wet curtain system is an economical and effective air conditioning method in greenhouse. Wet curtain cooling is the outside high temperature air through the soaked wet curtain, after humidification and cooling, forming cold wind; Cold air through the greenhouse, the greenhouse waste heat absorption, and then discharged outside the process. The process is composed of two stages, the former is the formation of cold air, and the latter is the heat exchange of cold air in the room.

Wet curtain in the installation is pieced together, wet curtain at the bottom of the support, its area is not less than 50% of the bottom area of the wet curtain, so as to ensure that the wet curtain in the long-term use of the process will not sink. The bottom of the curtain must not be submerged in water from the sink at the bottom, as it remains wetted while the cooling system is running, leading to the growth of algae and mold in the wet part. Using a set of water supply system, the height of the wet curtain is generally not more than 2 m, and the thickness of the wet curtain is 100mm~150mm.

In order to obtain the best cooling effect, the water supply of wet curtain is usually 60 L/min per square meter of the top area of wet curtain; If in the dry and high temperature area, the water supply should be increased by 10% ~ 20%. The water supply system should be able to evenly wet the entire wet curtain. There is a row of water holes on the outlet pipe, the aperture is 2.5 ~ 3.5 mm, the hole distance is 30 ~ 50 mm, the hole mouth is upward, and the water is sprayed directly onto the inner plate of the frame on the wet curtain. The hydrophobic wet curtain placed on the upper part of the wet curtain channels the water from the water pipe to the two sides of the upper part of the wet curtain, so that the evaporative wet curtain is evenly soaked.

The water supply can be adjusted through the selection of the pump and the valve on the water supply system. The water supply can be adjusted so that the water is evenly wet throughout the wet curtain. At the same time, you can see the thin water flowing down along the ripples.

Water quality and water circulation rate are critical to the successful operation of the wet curtain, and a thorough cleaning of the entire water supply at least once a week will help eliminate the deposition of impurities.

Algae can grow on the surface of wet drapery paper that is chronically wet, especially when it is exposed to sunlight. Once algae growth is a problem, be sure to dry the wet curtain thoroughly once a day. Wet shades should be used for shading if possible.

Biological agents can be used to control the growth of algae or other microorganisms in about a quarter of the conventional dose. Chlorine and bromine can also be used for wet curtain cleaning, but they are not suitable for long-term use of large doses, short-term treatment of the concentration of 3 to 5 ppm (ppm), continuous treatment, the concentration of 1 ppm can control odor and algae growth.

Do not use untreated surface water in the wet curtain system, because it often contains a lot of nutrients, easy to cause algae and mold breeding, tap water should be used.

Good maintenance is the best way to ensure the cooling efficiency of the wet curtain and extend its service life.

Check the wet curtain condition, pay special attention to its surface scaling and algae breeding.

Clean the tank and circulatory system regularly (usually once a week).

The wet curtain must be thoroughly dried every day. In most cases, turning off the fan 30 minutes after the pump has stopped will allow the curtain to dry completely, helping to curb algae growth.

The bottom of the wet curtain should not be soaked in water for a long time, because the wet curtain will suck up the water like a sponge, resulting in the growth of algae and mold. When the cooling system is turned off, please check to see if the water in the sink is empty.

If a wet curtain is used in a closed environment and is left in a humid state for a long time, it will quickly develop odors and cause algae and bacteria to grow on wet surfaces. At this time, turn off the water supply system, let the fan continue to run for more than 30 minutes, so that the wet curtain dry.

Keep the sink, water tank, water circulation system and pump inlet clean. Once the water circulation system is not clean, it is difficult to control the formation of algae and scale on the wet curtain surface. The tank should be covered and kept out of direct sunlight.

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