What is the cooling capacity in tr of a cooling tower for. Rp m 2 rp m 1 cfm 2 c fm 1 staticpressure 2 static pressure 1 cfm 2 cfm 12 ho rsep ower 2 ho rsepow er 1c fm cfm 3 formulas. Cstn july 2003 l et s take a look at how to calculate cooling tower blowdown. Department of energy idaho operations office idaho national engineering laboratory this is an informal report intended for use as a preliminaryor working document work supported by the u. Cooling tower blowdown equation by james mcdonald, pe, cwt originally published. A cooling tower is heat removal device that uses water to transfer process waste heat into the atmosphere. How to optimize the energy efficiency of cooling towers. The condenser performance test and thermal performance analysis of variable conditions in tqnpc.
It is used in cooling tower treatment chemicals for corrosion inhibition or as a tracer to determine the. Chemical engineering site already published articles on cooling tower components and cooling tower efficiency calculations. The basic cooling tower process is outlined in figure 1. A cooling tower is the equipment used to reduce the temperature of a water stream by extracting heat from water and emitting it to the atmosphere. F o r m u l a s a n d t a b l es formulasandtables fanlaws. Course contents evaporative coolers, often called swamp coolers, are cooling systems that use only water and a blower to circulate air. A critical element of operation at many combined cycle power plants is energy transfer in one or more cooling towers.
The technical data has been taken from a mechanical draft cooling tower. The calculation of cooling tower efficiency involves the range and approach of the cooling tower. Maximum cooling tower efficiency is limited by the wetbulb temperature of the cooling air. Monroe the questions most frequently asked of a fan engineer about axial flow fans for todays wet cooling towers generally cover. This is the difference between the cooling tower water inlet and. The purpose of a cooling tower is to conserve water. Cooling tower calculations water technology report. Understanding the basics of cooling tower heat transfer. The wetbulb temperature is a type of temperature measurement that reflects the physical properties of a system with a mixture of a gas and a vapor, usually air and water vapor. Understanding key components of cooling towers and how to improve water efficiency. The fanlaws can be used topredi ctthe pe rformance ofa towerwitha nonstandard motor. Effectivenessntu equations are solved to predict cooling tower performance at various fan speeds. Cooling tower heat transfer fundamentals power engineering.
A cooling tower primarily uses latent heat of vaporization evaporation to cool process water. How to increase your industrial cooling tower efficiency. When warm, dry unsaturated air is pulled through a watersoaked pad, water is evaporated and is absorbed as water vapor into the air. The important parameters, from the point of determining the performance of cooling towers, are. Minor additional cooling is provided by the air because of its temperature increase. The energy efficiency of a chiller is commonly expressed in one of the three following ratios. The historical derivation of this 15,000 btulh cooling tower ton, as compared to the 12,000 btuih evaporator ton, is based. Cooling tower evaporative cooling system measurement. A cooling tower is an essential piece of equipment in many production facilities used to bring down the temperature of the water used in many different process so it can be used again. Effective thermal design of cooling towers a stepbystep approach to coolingtower design, with an example calculation to make it clear jonny goyal air liquide engineering and construction, lurgi india various misconceptions arise when it comes to the thermal design of cooling towers. If a cooling tower is discharging blowdown from the cooling tower basin or cooling water supply pipe, a simple piping change to discharge blowdown water from the cooling water piping returning hot water to the tower can provide a 12% improvement in the energy efficiency of the hvac cooling system. Guidance for calculation of efficiency pue in data centers schneider electric data center science center rev 3 2 the benefits of determining data center infrastructure efficiency as part of an effective energy management plan are widely recognized. The heat picked up in the heat exchanger is returned to the cooling tower where it is rejected to the atmosphere by evaporative and convective cooling. This amount of heat could theoretically melt 1 ton of ice in 24 hours.
Approach to the analysis of cooling tower performance available from spx. Fact sheet covers the key components of cooling towers and how to improve water efficiency. Calculate a ton of cooling load using this formula. The purpose is to define a preventive maintenance program and plan for cooling towers at the suny polytechnic quad c building utica new york. Cooling tower plays a major role in chemical process industry. The major concern during i study the cooling tower theory was how to computerize the cooling tower theory from the calculation of ntu to the cooling tower performance analysis. Cooling tower efficiency program cycles of concentration. How to optimize the energy efficiency of cooling towers back to news when evaluating the success of any piece of industrial equipment, the main thing many people consider is the equipments priceperformance ratio how much it costs to operate the equipment weighed against with its ability to do its job, or simply called efficiency. Cooling tower basics calculation formulas cooling tower efficiency. Scale and bacterial growth may reduce the operating efficiency of heat exchange devices like cooling towers, condensers and heat exchangers. Water savings of cooling tower efficiency measures for use in performance contracts. Cooling tower efficiency calculations cooling tower approach. Cooling tower performance is also related to the amount of air moving through the tower and coming into direct contact with the water.
Guidance for calculation of efficiency pue in data centers. If you read this book carefully, you can make any cooling tower design. In practice, the cooling tower efficiency will be in between 65 to 70%. Cooling towers use the evaporation to cool the circulated water. Cooling tower cycles of concentration as pure water is evaporated, minerals are left behind in the recirculating water. A cooling tower use evaporative cooling to reduce the temperature of circulated water, and. Understanding key components of cooling towers and how to improve water efficiency federal energy management program. They can achieve water temperatures below the dry bulb temperature tdb of the air cooling air but not the wet bulb temperature. All cooling towers operate on the principle of removing heat from water be evaporating a small portion of water that is recirculated through the unit. To calculate cycles of concentration, divide the cooling tower hardness and conductivity by austin waters hardness and conductivity. In summer season the ambient air wet bulb temperature raises when compared to winter season so cooling tower efficiency limiting in summer season. When water evaporates, it absorbs latent heat of vapourization from the water and thereby causing the remaining water temperature to drop. At these condi tions, the cooling tower rejects 15,000 btuih per nominal cooling tower ton. For cooling tower, enter the water quality analysis of the circulating water in the cooling tower and blowdown set points for your cooling tower.
Design of mechanical draftcooling tower and determination of thermal efficiency prof. Highefficiency chillers can produce chilled water using less than 0. Although cooling towers are generally some of the most costeffective cooling mechanisms as compared to other cooling technologies such as many dry air cooling systems, it is still important to monitor your industrial cooling tower efficiency and run it. Understanding the aspects that affect evaporative cooling. Cooling tower extracts heat from the condenser water by two modes. Cooling tower efficiency calculations chemical engineering site. The water that is evaporated at the cooling tower is pure, that is, it doesnt contain any of the. Ajit prasad dash1, kishor kumar panda2, ajay kumar yadav3. In this article explained about basic concepts of cooling tower, types of cooling towers, formula for cooling tower efficiency. Cooling towers make use of evaporation whereby some of.
For example, a cooling tower sized to cool 4540 m3hr through a. Best management practice and guidance manual for cooling. Cooling tower basics and common misconceptions introduction in comparison with most other industrial equipments, the water cooling tower is a simple device, based on the direct contact of two of the earths most common substances. This cooling tower quiz module covers the design, calculations, operations and cooling water treatment etc which will be a refresher. Cooling tower efficiency calculation is described in this article. They reject process heat from the cooling water to atmosphere and keep the water cool. Performance analysis of cooling tower international journal of. Process leaks, windage, and drift are really just forms of uncontrolled blowdown. The mass balance around a cooling tower as illustrated in the figure to the right is. How to calculate tons of cooling for a cooling tower. Basic concepts of cooling tower, types of cooling towers, formula for cooling tower efficiency makeup water, drift losses, evaporation losses. Energy efficiency of cooling towers may 9, 2018 wednesday 7. Cooling tower is an essential piece in most of the chemical process industries and in hvac applications.
Formulas ra nge e ntering water tem per ature leavingwater temperature approa ch le avingw atertem per ature ambien twetb ulb temperature he at reje cted by a cooling tower. One common constituent of cooling tower chemicals is molybdenum mo. A refrigeration system must also reject the heat that it removes using a cooling tower for water cooling the condenser most efficient or using fans for air cooling the hot refrigerant of the condenser coil. Preventive maintenance program and plan for cooling. Understanding wet bulb temperature and other aspects that affect evaporative cooling tower performance.
No nonsense water treatment cooling tower efficiency and approach. Design of mechanical draftcooling tower and determination. Cooling tower basics calculation formulas cooling tower. Cooling tower efficiency calculations cooling tower efficiency calculation is described in this article. In the words of an excellent reference manual on cooling, evaporation is utilized to its fullest extent in. Cooling tower bureau of energy efficiency 9 figure 7. Fan energy requirements are determined for counterflow and crossflow towers designed for low initial cost and for energy efficiency. Abstract this paper presents detailed methodology of a induced draft cooling tower of counter flow type in which its efficiency, effectiveness, characteristics are calculated. Cooling towers are used in power plants to reject heat to the atmosphere by lowering down the water temperatures that sustain the equipments reliability and plants production capacity. A cooling towers job is to reduce the temperature of water through refrigeration. The condenser performance test and thermal performance. Cooling tower efficiency cooling tower efficiency can be expressed as efficiency 100t1t2t1t3 where t1 inlet temperature of water to the tower t2 outlet temperature of water from the tower t3 wet bulb temperature of air. As evaporation continues, the water becomes more concentrated than the original make up water. If you read this book carefully, you can make any cooling tower design programs by yourself.
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