The proposed cooling system is specific to the retarder and was shown to be significantly more effective. Connect potential users with existing users of evaporative cooling devices to share advice on construction, and use, and cost of these devices. Systems using evaporative cooling are readily available, inexpensive, portable, and do not require external power. Course contents evaporative coolers, often called swamp coolers, are cooling systems that use only water and a blower to circulate air. As relative humidity increases above 70 percent, the potential reduction in thi is less than 10 percent.
According to the literature published so far, most of the researcher hold view. Sprays small droplets of water through the opening of the louvers pros desirable for plant conditions. Analysis of evaporative cooling and enhancement of condenser. Evaporative cooling is deemed to be an appropriate alternative cooling mechanism for the cooling of engi neering systems in operation due to its simplicity, power saving characteristics as well as its attendant success as a cooling mechanism in other relevant applications. Although it is not common in brazil, evaporative cooling systems have a great potential to provide thermal comfort in places where the wet bulb temperature is low. Two stage evaporative cooling consist of indirect evaporative cooling system and direct evaporative cooling system. Description of the system in direct evaporative coolers, nonsaturated outside air is blown through a water saturated pad and evaporation occurs. They found that the system thermal cop ranged from 0. Two small coconut coir pads of different configurations were fabricated and tested using a laboratory.
Heat rejection rates from a platefin tube type condenser are determined for. Evaporative cooling design guidelines manual for new mexico. Review of research and application of evaporative cooling in. Performance improvement techniques for evaporative air. The following table 1 from manufacturers literature can be used to estimate. The proposed system has several potential advantages over evaporative cooling or refrigeration cooling used separately. Indirect evaporative cooler another type of evaporative cooler is the indirect evaporative cooler which, like the direct evaporative cooler, is more economical to operate and has lower initial cost compared to refrigerated cooling. The air passes straight across the humidifier into the cooling chamber in direct evaporative cooling system, while the air is first precooled with mostly heat exchangers before passing through the cooling pad or vice versa depending on the purpose in an indirect evaporative cooling system 21. Novel desiccant cooling system using indirect evaporative. The lower air injection temperature of this system as compared to evaporative cooling results in re duced air flow requirements to meet the same cooling load. While several different types of this particular system exist, pdec tower with spray was studied in that it is flexible, efficient, and prevalent. The humidified air stream provides a low temperature sink. Evaporative cooling pads that are saturated with water, a substantial cooling effect is realized due to the evaporation of that water.
There are two basic types of evaporative air coolers eacs. Evaporative cooling help page 1 of 20 standalone evaporative cooling on roa deck general overview the standalone evaporative cooling configuration assumes that the direct andor indirect evaporative cooling device is located on the roa deck immediately upstream of the main cooling coil. To model direct or indirect evaporative cooling as options of the airdistribution system, follow these steps. Methodology in order to assess the proposed sdecst, sdecpv, and sdecpvt system performance, a. Analysis of a solid desiccant cooling system with indirect.
In comparison with indirect evaporative coolers the dpc does not require an external secondary airstream because of its regenerative arrangement, i. The direct evaporative air coolers are also known as swamp coolers. Evaluating and selecting cooling systems for different. Nov, 2016 previous designs have integrated the retarder cooling into the engine cooling which has proved to be unsatisfactory. Modeling of a regenerative indirect evaporative cooler for. Direct evaporative cooling systems is a technology which involves adiabatic humidification and cooling of air with supplementary heat exchange facilities to lower final air temperature and try to reduce relative humidity. Evaporative cooling system the efficiency of evaporative cooling can be greatly reduced by compacting of cooling pads, improper operation of fans, greenhouse doors remaining open, and insufficient water supply to cooling pads. Performance analysis and optimal parameters of a direct. Very few studies have been reported in the literature concerning the effects of evaporative cooling on the stress level of dairy cattle housed in humid environments.
Investigation of a novel dew point indirect evaporative air. Operational mode optimization of indirect evaporative cooling in hot. The use of indirect evaporative cooling technologies is an effective way to reach high energy efficiency systems and to reduce primary energy consumption. Abstractnow days due to energy crisis and harmful effect to. In pakistan, pad type direct evaporative cooling dec system is. Though the present tractor has a forced circulation system, it is still worthwhile to get acquainted with the other three systems.
In comparison with indirect evaporative coolers the dpc does not require an external secondary airstream because of. Suited for virtually all geographic locations, the coolair evaporative cooling system. Evaporative cooling, of any type, can only meet ashrae standard 55 comfort levels when the ambient humidity ratio is below 0. Consists of a fan and cellulose pad on the opposite end which has water going through it pros effective cooling cons high fan power imbalance of temperature zones fogging system. Today, adiabatic evaporative cooling uses the principles of the ancient system with the benefit of 21st century technology within the category of thermal management units. The research of the key problem of evaporative cooling. A mathematical model of an evaporative cooling pad using. Jan 01, 2014 analysis figure 3, when the packing thickness is 300 mm, with the increase of water spray density, all kinds of packing overall showed a trend of rise of the direct evaporative cooling efficiency, when the thickness is 450 mm, with the increase of water spray density, all kinds of packing efficiency of direct evaporative cooling trend of first. Mar 23, 2017 evaporative cooling is a natural phenomenon that occurs when moving air passes over a wetted medium or water source, i. When warm, dry unsaturated air is pulled through a watersoaked pad, water is evaporated and is absorbed as water vapor into the air. Simulation analysis of the four configurations of solar.
Direct expansion dx systems deceptively consume no water to produce cooling, but use more electricity than evaporative cooling systems. Evaporative cooling occurs when the vapor pressure of water is higher than the corresponding partial vapor pressure in the adjacent air. Technoeconomic analysis of a solar desiccantevaporative. Evaporative cooling design guidelines cedengineering. Numerous studies have been conducted to reduce energy consumption during evaporative cooling 8. Due to various climatic conditions in erbil, results in various outlet condition the effectiveness in iec stage varies in between 5565 % and the effectiveness of two stages iecdec varies in between a range of 90110 %. The southwest is most familiar with direct eacs and are commonly used for residential and commercial cooling.
Aug 25, 2020 literary criticism may have a positive or a negative bias and may be a study of an individual piece of literature or an authors body of work. In a dec, water is vaporized in the airstreams and the heat and mass transfer between air and. Investigating applicability of evaporative cooling systems for. This dissertation focuses on use of airside economization ase, direct evaporative cooling dec, indirect evaporative cooling iec, and indirectdirect evaporative cooling idec as a way to. Types of cooling tower systems cooling towers are usually designed for specific purposes. The zeerpot is an evaporative cooler, which cools the inside by convective. Used in conjunction with coolair fans, a temperature reduction of 1025 degrees is commonplace. Experimental investigation of evaporative cooling systems for. The performance of the systems was evaluated and compared for agricultural storage and livestock airconditioning application in pakistan. Evaporative cooling equipment can be of the direct evaporative cooling dec type or. Rotary heat exchangers are typically used to remove this heat in currently available desiccant equipment, but these. Types of cooling systems there are two basic types of evaporative air coolers eacs. In indirect evaporative cooling, a secondary scavenger air stream is cooled by water. Schiano 2004 mentioned that porous pottery and clay jars were used for cooling in a system called muscatese evaporative cooling system.
Maintenance guide for greenhouse ventilation, evaporative. Analysis of a solid desiccant cooling system with indirect evaporative cooling bellemo, lorenzo publication date. An investigation of indirect evaporative coolers, iec w. Evaporation of water removes heat from the atmospheric air and from the first heat exchanger containing. Whenever the efficiency of evaporative cooling is reduced, the air temperature inside the greenhouse increases. Study,design and analysis of two stage evaporative cooling system. Indirect evaporative cooling humidifies the exhaust air from the. Eleventh international ibpsa conference glasgow, scotland july 2730, 2009 simulation of passive downdraught evaporative cooling pdec systems in energyplus daeho kang1 and richard k. International journal of engineering research and general. Evaporative cooling systems require less energy input than mechanical vapor compression systems because they obtain such input from ambient air. The human body uses evaporative cooling through sweating to maintain a constant body temperature.
Performance improvement techniques for evaporative air cooler. Many researchers have investigated different types of evaporative coolers, such as direct, indirect. Types and characteristics of evaporative cooling systems. Wetting the condenser of a refrigeration or heat pump system makes it. Keywords wind tower, natural ventilation, evaporative cooling, cfd, heat transfer device introduction in hot and arid regions such as the middle east, there is a large dependence on electricity to run mechanical systems for providing ventilation and thermal comfort. This paper reports a performance analysis for a new sustainable engineering application to beneficially reuse an abundant agricultural waste, coconut coir cocos nucifera, in evaporative cooling pads. Strand2 1 graduate research assistant, school of architecture university of illinois at urbanachampaign, champaign, il, usa 2 associate professor, school of architecture, university of illinois at urbana. Developments in the evaporative cooling industry have reliably increased the efficiency or effectiveness of the cooling media. Qualifying evaporative cooling units must have a minimum industry standard rated airflow of 2,500 cfm premium system. In direct evaporative cooling sensible heat energy. Rui camargo et al 9 in this paper discussed the principle of evaporative cooling for human comfort and the operating principle of evaporative cooling system and the development of mathematical equations for determination of saturation effectiveness. Evaporative air cooling can be categorized as direct, indirect and two stage system.
Green material prospects for passive evaporative cooling. Evaporative cooling occurs when air, that is not too humid, passes over a wet surface. Lin and sunden 3 published a literature survey on vehicle cooling systems for reducing the fuel consumption and the co 2. Indirect evaporative cooling an indirect evaporative cooling process would seem more viable than direct evaporative figure 5. Types of evaporative cooling two types of evaporative cooling system. Combined evaporative cooling this type of evaporative coolers combine indirect with direct evaporative cooling. In the process sensible heat of air evapo rates some water. Evaporative cooling help page 1 of 20 standalone evaporative cooling on roa deck general overview the standalone evaporative cooling configuration assumes that the direct andor indirect evaporative cooling device is located on the roa deck immediately upstream of the main cooling. Uncertainties and error propagation part 1 of a manual on. This is accomplished by passing air inside a heat exchanger that is cooled by evaporation on the outside. Standalone evaporative cooling on roa deck hvac systems. Direct evaporative cooling dec indirect evaporative cooling iec in a direct evaporative air cooling dec system, air is taken in through porous wetted media or through a spray of water. On the options tab, select the appropriate description from the type field in the evaporative cooling section. Analysis of a solid desiccant cooling system with indirect evaporative cooling.
Modeling and design analysis of a regenerative indirect. Pdf study,design and analysis of two stage evaporative. Evaporative cooling is produced by passing atmospheric air over wet pads and the first heat exchanger. Analysis figure 3, when the packing thickness is 300 mm, with the increase of water spray density, all kinds of packing overall showed a trend of rise of the direct evaporative cooling efficiency, when the thickness is 450 mm, with the increase of water spray density, all kinds of packing efficiency of direct evaporative cooling trend of first. Review of research and application of evaporative cooling. Experimental investigation of evaporative cooling systems. Although criticism may include some of the following elements in order to support an idea, literary criticism is not a plot summary, a biography of the author, or simply finding fault with the literature. An investigation of indirect evaporative coolers, iec w ith. Pakistan and feasibility analysis of these ec systems for thermal. Parametric analysis of design parameter effects on the. Qualifying equipment must be new and be a permanently installed direct standard system or premium system, indirect or twostage evaporative cooling unit. Here we help you understand the various types of cooling towers, there advantagesdisadvantages and determine which cooling tower type is right for your industrial process. Experimental study on two type of indirect evaporative cooling heat.
Santamouris 2007 evaporative cooling was used and commercialized in desert coolers since 1920. Evaluating and selecting cooling systems for different climates. There is a tradeoff between water consumption and power consumption used at the site. Such systems have a great potential to provide thermal comfort in places where the wet bulb temperature is low. Modeling of a regenerative indirect evaporative cooler for a. Evaporative cooling systems evaporative cooling consists in the use of the water evaporation or other fluid in the presence of a draught, with a consequent cooling of the air. Different studies on evaporative cooling technologies are summarized in table127,28. A passive downdraft evaporative cooling pdec tower is a component that is designed to capture the wind at the top of a tower and cool the outdoor air using water evaporation. The effectiveness of the twostage evaporative cooling system is improved with an increase in mass flow rate of water. This evaporative cooling design guidelines manual for new mexico schools and commercial. Modern technology has dramatically increased the efficiency and effectiveness of evaporative cooling system. An evaporative cooling system is disclosed which uses a heat pipe device comprising first and second heat exchangers to transfer heat from the space being cooled to an evaporative cooler.
An experimental analysis of direct evaporative cooler by. On the create systems selection tab, select an airside system. According to the literature published so far, most of the researcher. Not all cooling towers work for all applications or industrial processes.
Strand2 1 graduate research assistant, school of architecture university of illinois at urbanachampaign, champaign, il, usa 2 associate professor, school of architecture, university of illinois at. Other types of evaporative coolers which uses less energy to operate, is for example some. The air passes straight across the humidifier into the cooling chamber in direct evaporative cooling system, while the air is first precooled with. Goldsworthy and white 2011 studied an analogous dec system design. An experimental study on an evaporative cooler for hot rural. The evaporative cooled condenser also can exchange heat with ambient air. While several different types of this particular system exist, pdec tower with spray was studied in. Reference system description type of model results qiu and riffat 29 novel evaporative cooling system analytical zhao et al.
Evaporative cooling equipment can be of the direct evaporative cooling dec type or indirect evaporative cooling iec type. In this study, three kinds of evaporative cooling systems such as direct ec dec, indirect ec iec, and maisotsenko cycle ec mec were locally developed at labscale. Abstract evaporative cooling is an energy efficient and environmentally friendly air conditioning technology. Evaporative cooling ec is an ancient technique that is usually suitable for hot and dry climatic conditions due to the potential of water vapor evaporation.
However, evaporative cooling systems rarely used in the air conditioning of occupied. An evaporative and desiccant cooling system for air. A summary of different studies on evaporative cooling systems 27,28. Performance analysis of a new sustainable evaporative cooling. The research of the key problem of evaporative cooling system. They also concluded that an increase of 15% in evaporative cooler effectiveness resulted in. Zolarmad zeer pot refrigerator heat and mass transfer analysis. During the last century evaporative cooling was reused for cooling in hot arid climates. Indirect evaporative cooling iec is a waterbased cooling technology that is attractive for space cooling in dry and hot climates due to its lower energy consumption compared to vapor compression air conditioners and lack of humidification compared to direct evaporative cooling maheshwari, alragom et al. The twostage evaporative cooling system suffers from high capital cost and pumping costs necessary to operate the extra indirect evaporative cooling system. Review of dew point evaporative cooling technology for air. Type of cooling system used in a data center is an important factor in the overall efficiency and reliability of the data center. These systems consist of a garment and water absorption crystals, which are soaked in water before use.
413 876 1364 648 1062 859 946 1006 503 1477 635 1129 593 895 750 195 182 14 518 1248 106 1369 1391 968 1071 1461 398 609 40 483 639 148 442 487 214 532