The efficiency of a tower is based on the original design conditions as well as the type. Selection and configuration 23 12 breechings, chimneys, and stacks a. If heat load calculations are low undersized equipment will be purchased. Guide for energy efficient cooling tower design and operation.
The objective of this measure is to optimize cooling tower efficiency by. Water efficiency reporting 12 cooling tower water audit report 12 audit comments 14 1. Cooling tower measurement and verification technical advisory group. This requires very large tower and results in huge evaporation and windage or drift loss. In the ideal case, the cold water temperature will be equal to the wetbulb temperature. This effort on the part of the designer results in an efficiency which, although greatly appreciated in the summertime, has the capability to produce performancedegrading ice formations during winter operation. Install chemical feed systems on larger cooling tower systems more than 100 tons install flow meters on makeup and blowdown water lines improve cooling tower water quality consider installing a sand filter or cartridge filter to reduce sediment in basin water consider installing a water softening system on the makeup water line. Many attempts have been made to correlate performance using drop theories, cooling efficiency, number of transfer units, all without proven results. Cooling tower performance in free cooling applications is dependent upon both the system and cooling tower design. High efficiency chillers can produce chilled water using less than 0. Cooling tower calculations xls free software download. Centrifugal pumps 23 10 chemical water treatment a. Cooling tower bureau of energy efficiency 5 syllabus cooling tower.
Pdf design and performance analysis of the cooling tower in the. 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. Cooling tower evaporative cooling system measurement and. Department of energy assistant secretary for resource. Types and performance evaluation, efficient system operation, flow control strategies and energy saving opportunities, assessment of cooling towers 7.
Cooling tower design calculations student cheresources. Nuclear plants would be particularly impacted by a cooling tower mandate because re. They are the point in the system where heat is dissipated to the atmosphere through the evaporative process, and are common in. Cooling tower plays a major role in chemical process industry. How do you calculate evaporation loss in cooling tower. This app performs ruleofthumb hvac cooling and heating load calculations for many types of commercial, industrial, institutional, and residential buildings. Water savings of cooling tower efficiency measures for use in performance contracts. System calculations factors that limit cycles of concentration system concerns treatment options overview cooling towers are an integral component of many refrigeration systems, providing comfort or process cooling across a broad range of applications.
The towers essentially a cooling tower is a type of heat exchanger. Accurate design data are best obtained by the actual tests over a wide range of operating conditions with the specified arrangement. Water efficiency management guide mechanical systems. High efficiency mechanical draft towers cool the water to within 5 or. 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 mass balance around a cooling tower as illustrated in the figure to the right is. 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.
The method allows analytical calculation of cooling tower. Calculations 417 cooling tower blowdown equation by james mcdonald, pe, cwt originally published. The above equation can be simplified in volumetric flow rates as follows. Meet cooling tower water efficiency standards and equipment requirements.
This process provides significant cooling to the remaining water stream that collects in the tower basin where it can be. Almost 14 th of makeup water water added in a cycle to substitute water losses in a cooling tower is dissipated 25. Assessing the performance of cooling towers and their effect. This paper explores the efficiency relationship between the tower and the chiller, but more specifically develops a methodology to measure and estimate this. Combined heat and power technology fact sheet series. Cooling tower makeup water calculation xls saubhaya cooling tower makeup water calculation xls saubhaya cooling tower makeup water calculation saubhaya cooling tower makeup water calculation xls saubhaya. Nov 30, 2016 chemical engineering site already published articles on cooling tower components and cooling tower efficiency calculations. Therefore, means by which the cooling tower s efficiency can either be controlled, or can be made to work toward the management of. Its role is to remove heat from a process, usually either a direct manufacturing process or from the condenser of a chiller. Austin water developed this program to help customers. 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.
All of the required cooling water was assumed to be makeup water, with the. Oct 17, 2016 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 as seamlessly as possible. Energy performance assessment of hvac systems bureau of energy efficiency 117 first calculate the kwton rating from the measured parameters. Mar, 2012 cooling tower design calculations posted in student. Cooling tower efficiency program frequently asked questions. Water efficiency audits 9 cooling tower water audit checklist 10 1. Hi, i am an engineering student, and i am working on a cross flow induced draft cooling tower. In this paper, a simple differential equation for counter flow wet cooling tower is solved analytically taking into consideration the nonlinear dependency of the saturated air enthalpy on temperature. I know the inlet and outlet temperature of water, volume flow rate of water and the heat load desired from the cooling tower. Drift eliminators are installed to prevent water entrained in the air from leaving the system. The calculation of cooling tower efficiency involves the range and approach of the cooling tower.
The size and cost of the cooling tower is proportional to the heat load. Save money on water and wastewater bills by identifying potential. In summer the ambient air wet bulb temperature raises when compared to winter thus limiting the cooling tower efficiency. 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. Cooling tower efficiency is limited by the ambient wet bulb temperature. The development of cooling tower theory seems to begin with fitzgerald. Cooling tower efficiency calculations chemical engineering site.
Regardless of cooling tower operating efficiency, approximately 1. Cooling tower efficiency calculations cooling tower approach. 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. The cooling tower efficiency program requires customers to register their cooling towers with austin water and submit annual inspection forms. Cstn july 2003 l et s take a look at how to calculate cooling tower blowdown. In counter flow induced draft cooling towers water and air both enter the top and exist at the top of the cooling. They reject process heat from the cooling water to atmosphere and keep the water cool. Cooling tower effectiveness in percentage is the ratio of range, to the ideal range, i. Assessing the performance of cooling towers and their. 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. This includes determination of cycle of concentration, evaporation loss, drift or windage loss, blow down water requirement makeup. Again, this will be a first issue releasing the actual engineering approach. How to increase your industrial cooling tower efficiency.
The actual energy use of a cooling tower is small, and is only a portion of the. However, it is possible to lessen this impact in both central and unitary systems by increasing their efficiency. The fanlaws can be used topredi ctthe pe rformance ofa towerwitha nonstandard motor. Cooling tower bureau of energy efficiency 9 figure 7. 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. Cop is a unitless number and does not include energy consumed by pumps, fans, or other ancillary components. The technical data is taken for mechanical draft cooling tower.
The cooling tower makeup water flow is the key parameter that is required to be measured using option b, as this must be equal to all the expected or unexpected losses of water from the system. Process leaks, windage, and drift are really just forms of uncontrolled blowdown. The common design calculation, the entu method is typically used when. 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. Design of mechanical draftcooling tower and determination of. The present paper is a detailed methodology for thermal design of cooling tower. The loss of efficiency and generation capacity means that less electricity is available to meet demand or to serve as reliable reserve capacity. Cooling tower makeup water calculation xls saubhaya makeup. New chemical treatment systems 23 11 boilers and accessories a. Cooling tower performance calculations are usually performed numerically. The efficiency of an absorption chiller is measured by the coefficient of performance cop, which is defined as useful thermal energy output i.
If you read this book carefully, you can make any cooling tower design programs by yourself. Test your knowledge on cooling tower online quiz chemical. Cooling tower efficiency calculations cooling tower efficiency calculation is described in this article. Cooling load calculations may be used to accomplish one or more of the following objectives. Cooling tower evaporative cooling system measurement. 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. 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. Film fill, because it offers greater heat transfer efficiency, is the fill of. The primary task of a cooling tower is to reject heat into the atmosphere.
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