Cooling towers principles and practice pdf

Cooling towers principles and practice 3rd edition by g. Each one pound of water that is evaporated removes approximately. General information above is an animation of a hyperbolic stacknatural draft cooling tower. In this handbook you will find many helpful formulas for use in the field such as formulas for. This paper presents detailed methodology of a induced draft cooling tower of counter flow type in which its efficiency, effectiveness, char acteristics are calculated.

Here we explain in full detail how cooling towers operate with example text, pictures, diagrams and principles. The cooling tower water efficiency principles documented within this. Cooling towers should be located with their small side toward the prevailing wind. Cooling tower efficiency calculations cooling tower approach. Cooling towers, wet cooling, dry cooling, aircooled heat. Principles of cooling towers all cooling towers operate on the principle of removing heat from water by evaporating a small portion of the water that is circulated through the unit.

Sean mcgowan reports top ten worst practices cooling towers. The year before, the neighboring community had experienced outbreaks of legionnaires disease, and even though the hospitals cooling towers played no role in those outbreaks, the chance to increase protections against possible future exposures of the bacteria that cause the disease was an important consideration. What is a cooling towers working principle, water cooling towers are widely used for thermal comfort in hospitals and hotels as well as in industrial areas. A cooling tower s function is to remove heat from a building or process application that generates heat and must be dissipated.

Stanford, cooling towers principles and practice, 2nd ed. Despite best practice guidelines available, it remains common to find examples of poorly designed and executed piping, which create a variety of hazards. Top ten worst practices cooling towers the poor design and installation of pipe work associated with cooling towers continues to be a concern across the industry. Again, this will be a first issue releasing the actual engineering approach. The operating principles of these devices are based on four essential. Refrigeration in cooling towers conductive heat flow general industrial and cooling water makeup contents. See the more detailed explanation of cooling towers systems. Braun provides foundational knowledge for the behavior and analysis of hvac systems and related devices. This title is the companion guide to cooling water treatment. Marketing cooling water treatment xvii 1 cooling system and heat exchange essentials 1 1. As with all branches of engineering, new technology calls for a level of technical knowledge which becomes progressively higher. Cooling towers should not be downwind or adjacent to fired heaters, flare stacks, or any heatproducing items, as these raise the ambient air temperature and reduce the towers cooling efficiency. The environment is friendly because when the hot water is cooled, the towers produce.

The emphasis is on the application of engineering principles, and features a tight integration of physical descriptions with a software program that allows performance to be directly calculated, with results that provide insight. This system sends cooling water out of the equipment and into a pond or cooling tower, which is open to the atmosphere. The gives both long sides an equal intake of fresh air. Principles and practices by colin frayne isbn 9780820603704. 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. In technical terms, cooling towers are engineered and designed based on a specified cooling load, expressed in refrigeration tons. Address best environmental practices for heat transfer efficiency, equipment reliability, asset life expectancy, maintenance costs, minimization of water and energy. They reject process heat from the cooling water to atmosphere and keep the.

The impact of ventilation cooling towers on plus energy houses in southern europe. Cooling tower performance basic theory and practice subject. The approach of this essential reference is practical and international, and it is based on 30 years of professional experience. Cooling tower efficiency calculations cooling tower efficiency calculation is described in this article. Principles and practice, third edition, aims to provide the reader with a better understanding of the theory and practice, so that installations are correctly designed and operated. Pdf on sep 22, 2011, eusiel rubiocastro and others published optimal design of cooling towers find, read and cite all the research. While it comes hot from the tower but goes back cold to the industrial process. If you read this book carefully, you can make any cooling tower design programs by yourself. Cooling tower bureau of energy efficiency 5 syllabus cooling tower. The cooling tower must be adequately sized to reject this same amount of heat. Air flows into the tower through openings in the bottom, and cools the entering hot water. The technical data has been taken from a mechanical draft cooling tower. In this handbook you will find many helpful formulas for use in the field such. The year before, the neighboring community had experienced outbreaks of legionnaires disease, and even though the hospitals cooling towers played no role in those outbreaks, the chance to increase protections against possible future exposures of the bacteria that.

Communication tower best practices osha 38770 6 2017. Kroger encyclopedia of life support systems eolss 2. Principles and practice table of contents introduction. An introduction to cooling tower water treatment cedengineering. Here evaporation occurs, removing heat along with the evaporated water.

A cooling towers function is to remove heat from a building or process application that generates heat and must be dissipated. Accepted industry practice for bacterial control is the use. Field erected type cooling towers are usually preferred for power plants, steel processing plants, petroleum refineries, and petrochemical plants. Cooling towers the development, practice, and performance of evaporative cooling systems or cooling towers have been described in numerous publications including some of those listed in the bibliography.

Types and performance evaluation, efficient system operation, flow control strategies and energy saving opportunities, assessment of cooling towers 7. Abstracta cooling tower is a heat rejection device. Principles and practice, third edition, aims to provide the reader with a better understanding of the theory and practice, so that installations are. Cooling towers are heat removal devices used to transfer process waste heat to the atmosphere. Cooling towers make use of evaporation whereby some of the. Technical information for cooling towers using recycled water. The cooling towers at biogen idec are the largest users of water in the facility. Mathie, chemical treatment for cooling water 6 colin frayne, cooling water treatment. Brian ford describes the principles and current practice of this innovative approach to cooling in the hot dry regions of the world.

Cooling towers are a special type of heat exchanger that allows water and air to come in contact with each other to lower the. This section discusses hyperbolic stacknatural draft cooling towers, such as the one shown above in the animation. The heat that is removed is called the latent heat of evaporisation. Nicolson, understanding cooling water treatment saves, authorhouse, 2004 ijser. To assist installation personnel responsible for operating cooling systems, a list of lessons learned over the past 15 years has been assembled. A cooling tower is one of the larger items of equipment, in terms of ground area, that must be located on a site plan. Osborn and publisher elsevier butterworth heinemann.

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. One of our most useful resources is the mechanism of threshold treatment. The tower often consists of a sprinkler system which wets a highsurfacearea substrate plates continuously, while air flow through the chamber converts liquid to vapor. Cooling towers 3rd edition 9780750610056, 9781483162744. This revised edition first, 1967 presents new developments in manufacturing practice and changes in construction such as the. 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. Colin frayne annotation this comprehensive book is the only one that addresses theory, practice, management, purchasing and marketing of cooling water systems in one volume. Intent in the foreword of cooling tower fundamentals published by marley cooling technologies, inc. The water consumption rate of a cooling tower system is only about 5% of that of a oncethrough system, making it the least expensive system to. Iron oxide, especially, contributes to fouling and deposition, which interfere with heat transfer. Since the cooling towers are based on the principles of evaporative cooling, the maximum cooling tower efficiency depends on the wet bulb temperature of the air.

Best practice guide apply to typical cooling towers and operators. Cooling towers make use of evaporation whereby some of the water is evaporatednto a moving air i. Cooling towers overcome most of these problems and therefore are commonly used to dissipate heat from watercooled refrigera tion, airconditioning, and industrial process systems. Downtime for equipment repair or replacement is always costly. Principles and practice, chemical publishing company incorporated ny, 1999 7 charles r. Cooling tower plays a major role in chemical process industry.

Each of these techniques has different principles of operation, strengths. It is then combined with makeup water, which replaces the evaporated water, and is sent through the system again. From thermodynamic principles, the outlet water temperature from the cooling tower. What is the working principle in the cooling tower. The water efficiency principles contained within this. Profusely illustrated, this handbook will enable professionals to understand the factors that may interfere and. This document is advisory in nature and informational in content.

Develop and implement a water systems management program for the cooling tower meant to include all types of evaporative cooling equipment and associated water systems. Best practice co2 threshold given by cibse and ashrae are. One helpful means to that end is the water cooling tower. Water flows perpendicular to the air through the fill by gravity. The fundamental principal employed in accomplishing this removal of heat is the evaporation of water. Examines the assessment, specification, installation, and maintenance of cooling towers. The cooling tower must be adequately sized to reject this same amount of heat to the atmosphere. When a requirement for free cooling is specified for a project utilizing cooling towers, certain considerations must be made from the very beginning of the project design. Finally, a case study on retrofitting of central chilled water system is presented in chapter 6. This revised edition first, 1967 presents new developments in manufacturing practice and changes in construction such as the elimination of timber packing in favor of plastics and the use of new technology and designs of drift eliminators to avoid biological contamination, particularly by legionella.

First, special care must be taken when laying out the cooling towers to prevent recirculation due to poor tower location and prevailing winds. Save up to 80% by choosing the etextbook option for isbn. They reject process heat from the cooling water to atmosphere and keep the water cool. Pdf 60 m3h nominal capacity cooling tower was designed, based on the required cooling water parameters in.

In practice the cooling tower efficiency will be in between 70 to 75%. Iii aircooled heat exchangers and cooling towers d. An assortment of formulas for the protection of cooling water systems possibly supplemented with zinc at the corrosive end of the spectrum and high performance polymers at the scaling end. Cooling tower wateris water circulated in an open system, such as the cooling tower and condenser of an airconditioning system or a turbine condenser. In the wet cooling towers the air is in direct contact with water and the cooling is caused mostly by evaporation and is much more efficient. Classification based on heat transfer method wet cooling tower this type of cooling tower operates based on evaporation. Experimental analysis of the performance of a mechanical. Since heat exchange is relatively poor in air, the surface area need to be large to compensate.

Factors affecting the location of cooling towers, other than convenience to water supply and return, are the prevailing wind, noise, and access roads. How cooling towers work w pictures, diagrams, principles 2016. Water conservation in cooling towers au best practice guidelines intent this document has been prepared to assist the owners and operators of cooling towers and evaporative cooling systems in reducing the water consumption of cooling systems while retaining required performance. This comprehensive book is the only one that addresses theory, practice, management, purchasing and marketing of cooling water systems in one volume. Many of these problems are preventable through proper cooling water chemistry treatment. Rutger botermans, peter smith, in advanced piping design, 2008. Pdf design and performance analysis of the cooling tower in the. Cooling towers quiz questions hvac certification practice tests. Guides and recommended procedures for water treatment. Warm recirculating water is sent to the cooling tower where a portion of the water is evaporated into the air passing. A plume is formed in these towers which is a cloud of very small droplets 1. Chilled water is cold water, circulated in a closed system, that serves as a medium for transferring cold temperatures for air cooling. For modern, highefficiency cooling towers, drift is about 0.

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. Drift eliminators are installed to prevent water entrained in the air from leaving the system. Cooling tower operation forced draught cooling towers use the evaporation of a liquid often water into air to achieve cooling. Is the companion field guide handbook to cooling water treatment principles and practices by colin frayne.

Cooling towers, and their associated system components, are commonly used to provide comfort cooling for large commercial buildings including office buildings, retail. Cooling tower systems are an integral part of many refrigeration and process cooling systems across all industries, in particular the commercial property industry. These towers are larger in size compared to the package type cooling towers. Mechanical geothermal water cooling tower in south. Cooling water treatment principles and practice water. Crossflow is a design in which the air flow is directed perpendicular to the water flow. Principles of heating, ventilation, and air conditioning in. A practical guide to cooling tower selection and operation by w stanford. Air flow enters one or more vertical faces of the cooling tower to meet the fill material. Airconditioning and mechanical ventilation acmv systems. The impact of ventilation cooling towers on plus energy houses in. In simple terms, we can define it as an ecofriendly device that can reduce the temperature of the warmest water in the most efficient way at any source. Cooling towers are used to reject heat through the natural process of evaporation.