In pakistan, pad type direct evaporative cooling dec system is. The desiccant dewpoint cooling ddc system 10 is a specific dec system, constituted by a desiccant wheel dw made of silica gel, a heat recovery unit hru, a dew point cooler dpc, and a heat source connected to the system by means of a secondary hot water circuit. There are two essential requirements for evaporative cooling. Schematics of solid desiccant and evaporative cooling systems 3. Cooling tower evaporation transfers heat from hvac systems and other processes into.
Principles and application of evaporative cooling systems. Some ways to make your evaporative air cooling system more water and energy efficient are listed in this guide. Evaporative cooling systems evaporative cooling is the process by which air temperature is reduced through the evaporation of water within an airstream. As mentioned previously, an important factor in selecting a suitable design of an evaporative cooling system is the humidity of the environment. Direct evaporative or swamp air coolers are one of the most important and common used cooling system in our country which have significant advantages compared to some other types of cooling. When evaporation occurs, this heat is taken from the water that remains in the liquid state, resulting in a cooler liquid. Us5056588a evaporative cooling enhanced cold storage. The system includes a desiccant chamber, at least one evaporative cooler, and a heat exchanger. Evaporative cooling design guidelines pdh courses online. In a desiccant cooling system, air can be passed over common solid desiccants such as zeolite or silica gel for dehumidification and to sensibly cool the air well below ambient temperature conditions in some form of evaporative cooling process.
Sources of energy excluding minerals and solid fuels derived from. The conversion of sensible heat to latent heat causes a decrease in the ambient temperature as water is evaporated providing useful cooling. Evaporative cooling does not waste water, it uses water to provide an environment that is. Waste means any waste, wastewater, waste effluent, or pollutant, including any of the following. Nonoxidizing biocide type should be switched when the effecti. Evaporative coolers, also called swamp coolers, provide energyefficient. Evaporative cooling performance of alkaliactivated. The types of waste will be the same for unit 3 and for the carty solar farm. Mar 23, 2017 evaporative cooling is a natural phenomenon that occurs when moving air passes over a wetted medium or water source, i.
Cooling of industrial plants using evaporative coolers. These components are alu minum pad, cool air fan, pump and sump. There are two basic types of evaporative air coolers eacs. Results show that geopolymer materials show good behavior for this type of testing, and the best of them were the composition with the coarse sand as an aggregate. This thesis investigates the performance of a solid desiccant cooling system implementing indirect evaporative cooling processes. Moisture is added to the cooled air stream prior to or during contact of the cooled air stream with the cold storage unit to effect enhanced cooling of the cold storage unit due to evaporation of all or a. Compared to airconditioning which uses mechanical refrigeration, the evaporative cooling can fully satisfy building cooling loads using onefourth the energy of conventional equipment. This paper investigates the performance of different types of solid desiccant evaporative cooling system focusing on hot and humid climate conditions.
By assuming a value of 80% for the efficiency of evaporative pad cooling systems equa tions 10 and 11 can be written as. Evaporative cooling design guidelines cedengineering. An open recirculating cooling system uses the same water repeatedly to cool process equipment. Cooling many industries generate heat in their processes and often need cooling water systems if need to discharge to natural waters or public sewer system may be required to cool that water first non contact cooling water is water used for cooling which does not come into direct contact with any raw material, product, byproduct, or waste. This manual on municipal solid waste management provides guidance to urban local bodies. In the process sensible heat of air evapo rates some water. Chemical treatment of water for cooling and heating systems. Economic impact analysis national pollution discharge. Figure 7 illustrates the water balance for a hybrid zero liquid dischar. Principles and application of evaporative cooling systems for. Solid desiccant dehumidificationbased airconditioning system for agricultural storage application.
Pdf improvement of evaporative cooling system efficiency in. Makeup water has also been provided directly as seawater and more recently treated sewage effluent. Modeling and simulation of evaporative cooling system in. Investigating applicability of evaporative cooling systems for. Study,design and analysis of two stage evaporative cooling system. Energy use by this system is minimal, which means great economic savings, while its installation is very easy as well as this, evaporative cooling enables zonespecific cooling. When warm, dry unsaturated air is pulled through a watersoaked pad, water is evaporated and is absorbed as water vapor into the air. A desiccantaugmented evaporative cooling system employing ventilation and recirculation cycle is shown in figure 1, the moisture latent load present in the process air is removed by a desiccant wheel a, which has a honeycomb structure for passing humid air. Post treatment of blowdown water from evaporative cooling tower operations to enable reuse.
Modelling and analysis of a desiccant cooling system using. Excel spreadsheets uga poultry house environmental. In cooling systems a solid desiccant or a liquid desiccant solution can be used to assist in the cooling process. The aim is to quantify the system thermal and electrical performance for varying component dimensions and operating conditions, and to identify its range of applicability. This waste is used in some evaporative cooling systems as cooling media. Suited for virtually all geographic locations, the coolair evaporative cooling system. Reduce temperature of wastewater by transfer of heat from the wastewater to another fluid or to the atmosphere cooling. Federal utility partnership working group seminar may 1819, 2016 cincinnati, oh. T depend only on the dry and wet bulb temperatures of the outside air at a con stant cooling efficiency.
In accordance with the present invention, a desiccantevaporative cooling system for providing cool and dry air to an enclosed structure is disclosed. As well as this, evaporative cooling enables zonespecific cooling. This manual is intended to be used as a tool for the design of successful and efficient evaporative cooling systems and will allow engineers to specify and design evaporative cooling systems with confidence. Two stage evaporative cooling consist of indirect evaporative cooling system and direct evaporative cooling system. Purchasing a new system there are some key things to consider when purchasing a new evaporative air cooler or system. Evaporative cooling is a method of converting hot air into a cool breeze using the process of evaporating water. 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. Evaporative cooling systems include cooling towers, evaporative condensers spray ponds cooling ponds. Solid desiccant air conditioning a state of the art.
Evaporative cooling performance of alkaliactivated tungsten. The desiccant chamber intermittently receives and drys a first airstream from the enclosed structure to produce a second airstream. Solid oxidizing biocides nonoxidizing biocides selecting biocide type of microorganisms sensitivity to ph life cycle time in system type and extent of program types of ontaminants i. Eacs require little energy, and because the presence of strong sunshine coincides with the need for cooling, a link with. Jul 01, 2016 it has the same construction as solar assisted solid desiccant evaporative cooling system as discussed earlier except in process air line direct evaporative cooler replaced by means of the auxiliary cooling coil powered by a vapor compression refrigerator as shown in fig. This cooling system can maintain a greenhouse interior temperature and relative humidity to about 20. The technology is a versatile and energyefficient alternative to compressorbased cooling. Key words evaporative cooling, building energy savings, mining waste, geopolymers. Disposal of waste prudent practices in the laboratory. Us5056588a evaporative cooling enhanced cold storage system. Instead, at great expense, the solids had to be hauled to a landfill for disposal.
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 %. Pdf airconditioning plays an essential role in ensuring occupants thermal comfort. Review of research and application of evaporative cooling. To use the spreadsheet simply input basic information about the house in question i. The zeerpot is an evaporative cooler, which cools the inside by convective. This online engineering pdh course discusses some of the pertinent design issues and guidelines for evaporative cooling systems.
Aesc tested three types of products that employed evaporative cooling technologies. Manual handling of industrial waste is the usual practice in developin. Schematics of solid desiccant and evaporative cooling systems. Design of ii stage evaporative cooling system for residential.
Experimental investigation of evaporative cooling systems for. Evaporative cooling system the evaporative cooling system installed to cool the furnace skids of the toscelik hsm walking beam furnaces is a semiclosed loop system. The direct evaporative air coolers are also known as swamp coolers. A desiccant wheel absorbs moisture from air due to pressure difference between partial pressure of moisture in the air and desiccant materials. Course contents evaporative coolers, often called swamp coolers, are cooling systems that use only water and a blower to circulate air. During evaporation, water needs the latent heat of vaporization, which is obtained from ambient air and decreased air temperature 7. The igp office in gulbarga uses passive downdraught evaporative cooling pdec system where air passes through a layer of water in the wind tower. Applications for environmentally friendly cooling world bank. Desiccant has a property of regeneration so it can be recirculated and reused. As the waste water infrastructure has developed and with the ever increasing demands on desalinated water, treated sewage effluent has become one of. A mathematical model of an evaporative cooling pad using.
The mechanical draft evaporative cooling system for the combined cycle power block will include eight identical. This cools down the water and that water is sent to the interiors of the building which is similar to the earth tunnel air conditioning system. In addition, other systems such as the solid absorption plants are currently. Evaporative cooling systems require less energy input than mechanical vapor compression. Therefore, evaporative cooling works by utilizing the natural process of water evaporation, along with an air moving system, to create an effective cooling environment. It has been observed by various authors 57 that the temperature can be lowered by 68 c with evaporative cooling in greenhouses. The air passes straight across the humidifier into the cooling chamber in direct evaporative cooling system, while the air is first precooled with. There are several types of evaporative coolers including the following.
Morris 3 reported the greenhouse cooling potential by evaporative cooling through a simple equation. Green material prospects for passive evaporative cooling. This evaporative cooling design guidelines manual for new mexico schools and commercial. Cooling and heating systems prepared and presented by. Return air from conditioned space is mixed with the outdoor air to decrease the temperature of process air. Review of research and application of evaporative cooling in.
Best management practice and guidance manual for cooling towers. Evaluation of a direct evaporative roofspray cooling system carrasco, a. However no direct comparison with other technologies was carried out. Water handbook open recirculating cooling systems suez. This can prevent the installation of an evaporative cooling system in a particular location. This analysis of cooling tower impacts has been performed based on the preliminary design. Compared with solid desiccant cooling systems, for example, the twds, liquid desiccant cooling systems have the advantages of lower regeneration temperatures and flexibility in operation.
The quantity of solid waste was estimated to be an average of approximately 5 tons per month for each of units 1 and 2. The greater the difference, between the two temperatures, the greater the evaporative cooling effect16. Connect potential users with existing users of evaporative cooling devices to share advice on construction, and use, and cost of these devices. According to the american, society of heating and engineers ashrae,advanced two stage evaporative coolers can use 60%75%less electricity than conventional refrigerantbased ac system. Other types of evaporative coolers which uses less energy to operate, is for. Theoretical performance analysis of coconut coir as media in. Key factors are not expected to change during facility final design. Experimental investigation of a liquid desiccant cooling. Management of industrial solid waste isw is not the responsibility of. The energy efficiency of evaporative cooling is especially demonstrated when cooling large interior spaces such as industrial plants. Cooling towers, spray ponds, and evaporative condensers are used for this purpose. Modeling and optimal design of evaporative cooling system. The performance of evaporative systems deteriorates as the humidity. Path 1 3 highlights the air temperature changes that occur through indirect evaporative cooling.
The principle underlying evaporative cooling is the fact that water must have heat applied to it to change from a liquid to a vapor. Also, liquid dessicants such as lithium or calcium chloride have been used for air dehumidification processes. Conventionally, swamp coolers are used in the poultry shedshouses. Federal utility partnership working group seminar may 1819, 2016. Modeling and optimal design of evaporative cooling system in. Municipal solid waste incineration world bank document. Desiccant cooling system an overview sciencedirect topics. The overall sequence for testing is depicted in figure 7. This results in the evaporation of the water into the air which reduces the air temperature and increases its moisture content. Direct evaporative systems direct evaporative cooling dec systems rely on the direct channeling of water into the air. What evapoatr vei air cooling systems are evaporative air cooling systems draw air over wetted pads and surfaces.
Novel application of organic rankine cycle orc technology. In developing countries about 40 % of the food waste is due to postharvest losses. It is common to work solely in one specific part of the industrial plant, so. Analysis of a solid desiccant cooling system with indirect. The invention provides an evaporatively enhanced cold storage system wherein a warm air stream is cooled and the cooled air stream is thereafter passed into contact with a cold storage unit. Pdf study,design and analysis of two stage evaporative.
Evaporation a wastewater treatment alternative wwd. Water quality guidelines for evaporative cooling products. An evaporative cooling system is suitable for hot and arid climates, whereas indirect evaporative systems such as water ponds and roof spray cooling systems can also be suitable for humid climates. Energy use by this system is minimal, which means great economic savings, while its installation is very easy. The cooled humidified air is distributed inside to the space, or process to be. The system optimization carried out in 12 highlighted that the electrical cop is the critical economic or environmental justification for installing a desiccant system when thermal sources such as solar or waste heat are available. Air movement velocity influences the performance of an evaporative cooling system. Pdf improvement of evaporative cooling system efficiency. The desiccant material is impregnated on the inner surface of the honeycomb structure.
A solid dcs consists of a desiccant wheel, ecw and direct evaporative coolers decs. Assessment of energy, water and waste reduction options for the. Used in conjunction with coolair fans, a temperature reduction of 1025 degrees is commonplace. Overview cooling towers are dynamic systems with inherent mechanical, operational, and chemical challenges. Waste management facilities international finance corporation. Heat absorbed from the process must be dissipated to allow reuse of the water. Cooling tower blowdown and treatment waste streams give rise to disposal issues. Evaporative cooler an overview sciencedirect topics. Abstract roofspray cooling systems are being extensively used to reduce the airconditioning usage in industrial and commer cial buildings. Evaporative cooling pads that are saturated with water, a substantial cooling effect is realized due to the evaporation of that water.
Several waste types find their way into the municipal solid waste stream, which. Types of evaporative cooling two types of evaporative cooling system. Solid oxidizing biocides nonoxidizing biocides selecting biocide type of microorganisms sensitivity to ph life cycle time in system type and extent of program types of. Concept of evaporative cooling evaporative cooling is the process by which the temperature of a substance is reduced due to the cooling effect from the evaporation of water. Coconut coir is an agricultural waste that is produced in reasonable quantities in some developing countries of the world like nigeria. An experimental study on an evaporative cooler for hot rural. The recovery of valuable materials or separation of hazardous materials from.
Liquid desiccant regeneration requires a temperature level of 4050c 6, 7, which can be easily obtained from solar energy 7 or waste heat recovery. Review of dew point evaporative cooling technology for air. A 2stage evaporative cooling system can deliver cool indoor air with a relative humidity in the 50%65% range, while direct system typically condition the air at around 70% relative humidity. Many researchers have investigated different types of evaporative coolers, such as direct, indirect, and modi. Paurine, in comprehensive renewable energy, 2012 3. In technical terms, cooling towers are engineered and designed based on a specified cooling load, expressed in refrigeration tons.
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