F and the actual temperature drop measured across the cooling media is 27. In ideal case the cold water temperature will be equal to the wet bulb temperature. The calculation of cooling tower efficiency involves the range and approach of the cooling tower. In the ideal case, the cold water temperature will be equal to the wetbulb temperature.
Doc cooling tower lab report sem yong hao academia. If there is available area, there will be even lower hp cooling tower options that enable a great amount of energy. High efficiency chillers can produce chilled water using less than 0. Jul 06, 2017 cooling tower thermal design manual sharif cooling tower thermal design manual cooling tower technical site of daeil aqua co. Energy efficiency in industrial process cooling systems. Pdf thermal calculation of the ejection cooling tower.
These handbook data are used to chart cooling tower approach temperature. 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. Design of mechanical draftcooling tower and determination. This amount of heat could theoretically melt 1 ton of ice in 24. Therefore, it likewise is independent of the cooling tower. Abstract this paper presents detailed methodology of a induced draft cooling tower of counter flow type in which its efficiency, effectiveness, characteristics are calculated. The technical data is taken for mechanical draft cooling tower. Assessing the performance of cooling towers and their. It is used in cooling tower treatment chemicals for corrosion inhibition or as a tracer to determine the. To capitalise upon the inherent energy efficiency of cooling tower systems the condenser water, and cooling tower systems must be properly designed, operating correctly and. A cooling tower is a heat rejection device which rejects waste heat to the atmosphere through the cooling of a. If you read this book carefully, you can make any cooling tower design programs by yourself. As this occurs, a small volume of water is evaporated, reducing the temperature of the water being circulated through the tower.
Cooling tower evaporative cooling system measurement. Its role is to remove heat from a process, usually either a direct manufacturing process or from the condenser of a chiller. 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 ra nge e ntering water tem per ature leavingwater temperature. For simplicity, constant cooling tower waterflow rate is assumed. The fanlaws can be used topredi ctthe pe rformance ofa towerwitha nonstandard motor. 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. Effect of heat rejection load and wet bulb on cooling. Chemical engineering site already published articles on cooling tower components and cooling tower efficiency calculations. Example of a realworld set of conditions for a cooling tower. 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. Drift eliminators are installed to prevent water entrained in the air from leaving the system. To capitalise upon the inherent energy efficiency of cooling tower systems the condenser water, and cooling tower systems must be properly designed, operating correctly and regularly maintained. The towers essentially a cooling tower is a type of heat exchanger. A ten percent increase in flow requires a thirtythree percent increase in horsepower.
Cooling tower evaporative cooling system measurement and. Design of mechanical draftcooling tower and determination of. Cooling tower efficiency calculations cooling tower efficiency calculation is described in this article. How to calculate tons of cooling for a cooling tower sciencing. For cooling tower, enter the water quality analysis of the circulating water in the cooling tower and blowdown set points for your cooling tower. Cooling towers can be split into two distinct categories.
Cooling tower systems include all components that provide comfort cooling by rejecting heat to the atmosphere through the evaporative process. Cooling tower efficiency is limited by the ambient wet bulb temperature. Again, this will be a first issue releasing the actual engineering approach of cooling tower with the examples in the world. Test your knowledge on cooling tower online quiz chemical. Water efficiency audits 9 cooling tower water audit checklist 10 1. Cooling tower bureau of energy efficiency 9 figure 7. Assessing the performance of cooling towers and their effect.
Guide for energy efficient cooling tower design and operation. In open circuit systems the recirculating water returns to the tower after 1 one ton of refrigeration is equal to 12,000 btuhour. Hvac cooling load calculations and principles sensible heat gain is the energy added to the space by conduction, convection andor radiation. Cooling tower plays a major role in chemical process industry. As shown in figure 2 on page 5, the greater the cycles of concentration, the less blowdown is required. Many people dont focus on cooling towers, because they just dont have the equipment high up on their priority list. Almost 14 th of makeup water water added in a cycle to substitute water losses in a cooling tower is dissipated 25. Scale and bacterial growth may reduce the operating efficiency of heat exchange devices like cooling towers, condensers and heat exchangers. Nov 30, 2016 chemical engineering site already published articles on cooling tower components and cooling tower efficiency calculations. Understanding key components of cooling towers and. The circulating water flow is determined by the number of pumps running and the pressure drop in the overall circulating water system. The number 500 is a constant, therefore is independent of the cooling tower.
The term induced draft denotes that air is drawn by fans through the flow of falling water and up and out of the cooling tower. The thermal capability of a cooling tower used for air condition ing is often expressed in nominal cooling tower tons. Highefficiency chillers can produce chilled water using less than 0. Best management practice and guidance manual for cooling.
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. The present paper is a detailed methodology for thermal design of cooling tower. The effect of the air water ratio on counter flow cooling. Department of energy assistant secretary for resource. This cooling tower quiz module covers the design, calculations, operations and cooling water treatment etc which will be a refresher for the experience and an eyeopener for the fresh chemical engineers. Evaporative cooling with a flat plate heat exchanger tower free cooling. 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. The magazine for energy efficiency and water conservation in industrial cooling systems chiller system optimization march 2015 10 a freecooling chillers h 2 o kw co 2 14 10 glycol tips for water chiller operators 16 central plant optimization for pepco energy services chiller plant 24 5 sizing steps for chillers in plastic process cooling. Fan performance curves generally are obtained under ideal, reproducible. How to improve water efficiency on your cooling tower. Cooling tower efficiency calculations cooling tower approach. At these condi tions, the cooling tower rejects 15,000 btuih per nominal cooling tower ton. In practice, the cooling tower efficiency will be in between 65 to 70%.
Towers designed at other conditions perform similarly. Cooling tower basics calculation formulas cooling tower. Chiller system optimization cooling best practices. F as in the above example, the cooling efficiency is 90%. One common constituent of cooling tower chemicals is molybdenum mo. Doc boiler efficiency and cooling tower efficiency engr. All of the required cooling water was assumed to be makeup water, with the. Effective thermal design of cooling towers a stepbystep approach to cooling tower 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. Water efficiency reporting 12 cooling tower water audit report 12 audit comments 14 1. In summer season the ambient air wet bulb temperature raises when compared to winter season so cooling tower efficiency limiting in summer season. They reject process heat from the cooling water to atmosphere and keep the water cool. The actual energy use of a cooling tower is small, and is only a portion of the energy involved in.
Cooling tower is an essential piece in most of the chemical process industries and in hvac applications. Thermal calculation of the ejection cooling tower and method of improving its efficiency article pdf available in journal of engineering physics and thermophysics 842. 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. How to optimize the energy efficiency of cooling towers. Sg sh 1 forwater mbh 10 00 b tuh re frigreation tons. Water efficiency management guide mechanical systems. L mass flow of water entering the cooling tower lbmin t. The technical data has been taken from a mechanical draft cooling tower. Cooling tower efficiency program cycles of concentration. Sep 17, 20 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. The efficiency of a tower is based on the original design conditions as well as the type of.
The difference between the entering and exit drybulb temperatures i. Cooling tower efficiency calculations chemical engineering site. Cooling tower makeup water calculation pdf saubhaya makeup. Energy efficiency of cooling towers may 9, 2018 wednesday 7. This cooling tower quiz module covers the design, calculations, operations and cooling water treatment etc which will be a refresher for the experience. Houston, texas improving cooling tower fan system efficiencies our system efficiency or losses are not as assumed and we need more air, horsepower increases by the cube of the flow. Evaluate the energy use of the cooling tower, this is mainly the fan and pump horsepower hp. To calculate cycles of concentration, divide the cooling tower hardness and conductivity by austin waters hardness and conductivity. However, the quantity of blowdown and subsequently makeup water is dependent on the towers cycles of concentration.
Calculating the tons for a cooling tower requires you to understand some basic information about it works. Together with the dosing pumps and the provided accessories, they are designed to guarantee the correct and efficient treatment of water flow in a cooling tower. Cooling tower makeup water quantity calculation saubhaya cooling tower makeup water quantity calculation saubhaya cooling towers understanding key components of and pdf cooling towers estimate evaporation losakeup water. A cooling tower is a heat rejection device which rejects waste heat to the atmosphere through the cooling of a water stream to a lower temperature. Figure 4 illustrates actual conditions that might be seen in a cooling tower operating on a mild spring day. Cooling tower thermal design manual sharif cooling tower thermal design manual cooling tower technical site of daeil aqua co. How to calculate tons of cooling for a cooling tower. A nominal cooling tower ton is defined as cooling 3 gpm of water from 95f to 85f at a 78f entering air wetbulb temperature.