The basics of wet cooling towers manufacturers of cooling. A cooling tower is a heat rejection device that rejects waste heat to the atmosphere through the cooling of a water stream to a lower temperature. Air flow enters one or more vertical faces of the cooling tower to meet the fill material. The fan deck supports the motor and fan of the water spray system. If it is not available it may be assumed as for natural draft cooling tower d 0. The performance of cooling towers is estimated by approach and range. Cooling towers overcome most of these problems and therefore are commonly used to dissipate heat from watercooled refrigera tion, airconditioning, and industrial process systems. Static height not considered for pump selection in closed loop. Cooling towers cooling towers, closed circuit cooling. Cooling towers continuing education for professional. Drift loss of the cooling tower is normally provided by the cooling tower manufacturer based on the process design. The required cooling tower design and size will be a function of following values.
If you read this book carefully, you can make any cooling tower design programs by yourself. The basics of cooling tower water treatment the purpose of a cooling tower is to remove the heat generated by an hvac system cooling of compressor refrigerant and heat generated by the compressor itself. Dec 25, 2011 a cooling tower is an equipment used to reduce the temperature of a water stream by extracting heat from water and emitting it to the atmosphere. Enexio a cooling tower is a device which is used to extract excess heat from the process water stream and rejects this excess heat to the atmosphere.
Cooling tower calculations software program is a powerful, user friendly, software program for the analysis of induced, mechanicaldraft, counterflow cooling towers. 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. Before we look at how a cooling tower rejects heat. Cooling system cooling tower cooling tower basics cooling tower design jet cooling system jet engine cooling system. The fanlaws can be used topredi ctthe pe rformance ofa towerwitha nonstandard motor. Cooling tower plays a major role in chemical process industry. The relationships to obtain the geometric design of the cooling tower are presented in this section. The capability of the cooling tower is a measure of how close the tower can bring the water temperature to the wbt of the entering air. Drift eliminators are installed to prevent water entrained in the air from leaving the system. Cooling tower fundamentals is devoted to the implementation of water cooling systems which satisfy design and environmental requirements with sound engineering and responsible cost. Gravity systems, employed on bacs crossflow cooling towers, feature hot water basins mounted on top of the tower above the fill. A cooling tower water treatment system is an arrangement of technologies that remove damaging impurities from your cooling tower feed water, circulation water, andor blowdown. Cooling towers are used to remove heat from a building. 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.
A guide to troublefree cooling towers a basic understanding of cooling tower operation and maintenance will help keep a cooling water system running in top condition, year after year by david m. This design guideline assists engineers to understand the basic principles of cooling towers. Rp m 2 rp m 1 cfm 2 c fm 1 staticpressure 2 static pressure 1 cfm 2 cfm 12. Cooling tower basics calculation formulas cooling tower efficiency. Maintain cooling tower fill to prevent water from dripping or sloshing from the fill and onto the ground.
Best management practice and guidance manual for cooling towers. Cooling towers are heat removal devices used to transfer process waste. Although the most general definition of a cooling tower is something that removes waste heat from any industrial process or air conditioning condensor, wet cooling towers also sometimes called open circuit cooling towers are a little bit more complicated than that. Water flows perpendicular to the air through the fill by gravity. Here we explain in full detail how does a cooling tower work, cooling tower working principles with example text, pictures and diagrams.
Cooling towers vary in size and design based on the cooling load of a building. Feb 24, 2014 cooling tower thermal design calculator. Lets first look at the parts inside a cooling tower. With this design, the tower is mounted on legs, providing easy access to the fans and their motors. However, since double pipe heat exchangers are simple, they are used to teach heat exchanger design basics to students as the fundamental rules for all heat exchangers are the same. Department of energy assistant secretary for resource. Intent in the foreword of cooling tower fundamentals published by marley cooling technologies, inc. But what is a cooling tower water treatment system and how does it work. Cooling tower basics what are the basic of cooling tower. Recent advancement of the design involves a non clogging type nozzle. Cooling tower basins international district energy. A cooling tower is an equipment used to reduce the temperature of a water stream by extracting heat from water and emitting it to the atmosphere.
Cooling tower systems work by using water to extract waste heat from a system and ejecting it into the atmosphere primarily through evaporation. Cooling towers may either use the evaporation of water to remove process heat and cool the working fluid to near the wetbulb air temperature or, in the case of closed circuit dry cooling towers, rely solely on air to cool the working fluid to near. All the water passing through the fill should go into the basin. Closed circuit systems differ in that the return fluid often water, or sometimes water mixed with glycol circulates through the tower structure in a coil, while cooling tower water recirculates only in. The three key components of a cooling system are the cooling tower, recirculating pump, and heat exchanger. In a crossflow cooling tower, the hot water basin is used to distribute the warm return water flow uniformly over the tower fill see figure 6. Nozzles are used to provide uniform distribution of hot water inside a cell of a cooling tower. The basics of cooling tower water treatment the basics of cooling tower water treatment the purpose of a cooling tower is to remove the heat generated by an hvac system cycles is a comparison of the chloride content in the sump water versus the makeup water. Cooling tower fundamentals spx cooling technologies. Cooling tower basics calculation formulas cooling tower. The software program can be used for the analysis of existing towers or for the preparation of specifications for new towers. Cooling tower cycles of concentration as pure water is evaporated, minerals are left behind in the recirculating water. Cooling tower efficiency calculation is described in this article. 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.
Oncethrough cooling was a common design feature for large power plants in the last century, as the process could. In cooling towers with wellengineered mist eliminators, a common design drift rate is 0. Oct 02, 2016 the system has been designed so that the condenser water leaving the cooling tower and reentering the chiller condenser, must be around 27c 80. As this occurs, a small volume of water is evaporated, reducing the temperature of the water being circulated through the tower. What is a cooling tower water treatment system and how. Basics cooling tower performance basic theory and practice subject. 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. Cooling tower structures vary greatly in size and design, but they all function to provide the same thing. In the design of a cooling tower many parameters intervene and it is normally a lengthy and complex process. Best management practice and guidance manual for cooling towers prepared by jea for the control of pollutants discharged to the sanitary collection system. The pumping head determination procedure for the open tower piping loop differs from the conventional closed.
Suptic air conditioning and refrigeration systems ranging from light commercial to industrial applications may rely on cooling towers to remove waste. In this article explained about basic concepts of cooling tower, types of cooling towers, formula for cooling tower efficiency. Cooling towers are a special type of heat exchanger that allows water and air to come in contact with each other to lower the temperature of the hot water. The goal is to assure the implementation of water cooling systems which will satisfy all design and. Section b is devoted to cooling tower theory and calculations. See the more detailed explanation of cooling towers systems, diagrams, pictures and principles below table of contents what is a cooling tower how do cooling towers work. Cooling tower bureau of energy efficiency 7 figure 7. Cooling towers make use of evaporation whereby some of the water is evaporated into a moving air stream and subsequently discharged into the atmosphere. 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 technical data has been taken from a mechanical draft cooling tower.
Closed circuit systems differ in that the return fluid often water, or sometimes water mixed with glycol circulates through the tower structure in a coil, while cooling tower water recirculates only in the tower. I have one comment for absent of pdf download those concept note. A cooling tower is a heat rejection device which rejects waste heat to. Section a on cooling tower practice covers topics such as the design and operation of cooling towers. 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. A cooling tower is a device used in industry to cool hot water by partial evaporation before reusing it as a coolant. The inlet may take up an entire side of a towercross flow design or be located low on the side or the bottom of counter flow designs. Understanding the basics of cooling tower heat transfer.
The cooling load is determined by the size of a building from which. Hvac use of a cooling tower pairs the cooling tower with a watercooled chiller or watercooled condenser. 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. Crossflow is a design in which the air flow is directed perpendicular to the water flow. A series of spray nozzles in each hot water basin distribute the water evenly over the fill.
An hvac heating, ventilating, and air conditioning cooling tower is used to dispose unwanted heat from a chiller. For example, a cooling tower sized to cool 4540 m3hr through a. Today we are going to talk about how you can choose the right cooling tower system for areas with tropical climates. A water legged discharge or discharge reducer will. Cooling tower efficiency calculations cooling tower approach. A cooling tower is a specialized heat exchanger in which air and water are brought into direct contact with each other in order to reduce the waters temperature. Cooling towers employ either gravity distribution or pressurized spray systems to distribute water over the fill. The water exits the cooling tower and is sent back to the exchangers or to other units for further cooling. Here evaporation occurs, removing heat along with the evaporated water. F o r m u l a s a n d t a b l es formulasandtables fanlaws. It is then combined with makeup water, which replaces the evaporated water, and is sent through the system again. This video guides you through the basic operation of a chiller, making use of animations, illustrations, 3d models and real world photographs to help build your understanding. They reject process heat from the cooling water to atmosphere and keep the water cool. Best management practice and guidance manual for cooling.
Cooling tower basins home international district energy. Operation of a cooling tower choose and design a system that meets your process requirements. 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. Cooling is accomplished through the latent heat of vaporization. Cooling tower types cooling towers fall into two main categories. Typical closed loop cooling tower system is shown in figure 7. Large cooling towers are usually used in industries like power plants, petroleum refineries and various manufacturing facilities.
This system sends cooling water out of the equipment and into a pond or cooling tower, which is open to the atmosphere. Which cooling tower is best for tropical climates the climate conditions can somehow affect the performance of cooling towers due mainly to the fact that they make use of the surrounding air as well as water supply to do their job. Dec 19, 2017 cooling tower systems work by using water to extract waste heat from a system and ejecting it into the atmosphere primarily through evaporation. Cooling a stream of water to a lower temperature using evaporation does this.
System interactions are covered in more detail in system design options beginning on page 27. Water directly contacts surrounding air and a very small part 12% evaporate. Effect of condenserwater flow rate the condenser is sensitive to the water flow rate. A cooling tower is a device which is used to extract excess heat from the process water stream and rejects this excess heat to the atmosphere. See the more detailed explanation of cooling towers systems. Design of mechanical draftcooling tower and determination of. This evaporation increases the air temperature and humidity and decreases the temperature of the water making it possible to cool below the normal. However, the most common application of a cooling tower is inside an hvac system for cooling buildings. University of colorado boulder, co, usa overview system description secondary hvac systems air distribution room diffusers and air terminals duct design fan characteristics air handling units water distribution cooling coils pipes and pumps primary hvac systems electric chillers. Fundamentals handbook, chapter 26, represents the entering air wet bulb. Here we explain in full detail how cooling towers operate with example text, pictures, diagrams and principles. Fundamentals of heat and mass transfer in wet cooling towers. Water first passes through a heat exchanger where it absorbs heat. Again, this will be a first issue releasing the actual engineering approach.