So many businesses rely on cooling towers to perform vital services such as air conditioning, manufacturing and electric power generation. Understanding wet bulb temperature and other aspects that affect evaporative cooling tower performance. Arash 9 studied a new type of cooling tower with rotational splash type packing. Test your knowledge on cooling tower online quiz chemical. The project deals with the performance study and analysis of induced draft cooling tower, which is one of the deciding factors used for increasing the power plant efficiency also modelling and analysis of flow using software. In summer season the ambient air wet bulb temperature raises when compared to winter season so cooling tower efficiency limiting in summer season. Cooling tower is an essential piece in most of the chemical process industries and in hvac applications. Thermal performance of a cooling tower depends principally on the entering air wetbulb temperature. Cooling towers are often used in air conditioning applications to reject heat into the atmosphere. Cooling tower heat transfer fundamentals power engineering. The most reliable means to assess the cooling tower thermal performance is tower capability. Cooling tower fundamentals spx cooling technologies. If it is not available it may be assumed as for natural draft cooling tower d 0. How to optimize cooling tower waters ph balance chardon.
Heat is discharged into the atmosphere by the cooling tower via a secondary cycle with water as the process fluid. In the words of an excellent reference manual on cooling, evaporation is utilized to its fullest extent in. Cooling tower performance fan motor overamping thermal science overamping overamping occurs when the amperage drawn by the motor exceeds the amperage specified on the nameplate. The water consumption or the amount of make up water of a cooling tower is about 0. 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. Understanding the aspects that affect evaporative cooling. Student can use the psychrometric chart for determining the specific humidity, specific enthalpy, relative humidity 3. Cooling tower bureau of energy efficiency 9 figure 7. Lab 1b cooling tower performance and sensors for thermal.
Increased power through optimization of cooling tower. The solution promoting optimum and laminar airflow conditions of the cooling tower can result in a significant increase in plant power output. Code tower standard specifications cooling technology. Hilton h891 bench top cooling tower and its operating principles. Tradional hvac heating and cooling systems are used in schools, large office buildings, and hospital. Cooling tower efficiency calculation is described in this article. The performance parameters like range, approach, cooling.
A nominal cooling tower ton is defined as cooling 3 gpm of water from 95f to. Department of energy assistant secretary for resource. In which the thermal performance of cooling tower with and without rotational. Factors affecting cooling tower performance capacity utilization amount of water circulated range determined by the process it is serving determined by heat load and water circulation rate thus range. For the sake of this document, cooling tower systems include open recirculating circuit coolers, fluid coolers, and evaporative coolers, closed evaporative condensers. Cooling tower performance basics basic theory and practice. Pdf the performance of cooling towers is of great importance for the large number of nuclear plants that must rely upon cooling towers as their only. Experimental study of cooling tower performance using ceramic. Cooling tower performance spx cooling technologies. The lower the approach the better the cooling tower performance.
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. Nov 30, 2016 chemical engineering site already published articles on cooling tower components and cooling tower efficiency calculations. In existing cooling towers, the aerodynamics are suboptimal. A new model for tower performance prediction is imperative since economizer operation occurs at low temperatures and most cooling towers come equipped with vfds. In open circuit systems the recirculating water returns to the tower after 1 one ton of refrigeration is equal to 12,000 btuhour. A simplified calculation procedure of tower coefficient is presented. The main part of the installation is the cooling tower, hav. However, it requires large size compared with existing counter flow tower. Cooling towers can be split into two distinct categories. Finally confirmation tests verified this reliability of taguchi method for optimization of counter flow cooling tower performance with sufficient accuracy. Cooling towers are a very important part of many chemical plants. Cooling tower evaporative cooling system measurement and. Effects of relative humidity thermal performance cooling towers are rated most often using the inlet wet bulb temperature because these values are closely consistent with the enthalpy of the air. The contractor shall be given permission to inspect the tower.
This cooling tower quiz module covers the design, calculations, operations and cooling water treatment etc which will be a refresher. The results show that the cross flow cooling tower has high performance in the heat transfer process. Here we help you understand the various types of cooling towers, there advantagesdisadvantages and determine which cooling tower type is right for your industrial process. If you read this book carefully, you can make any cooling tower design programs by yourself. Cooling tower evaporative cooling system measurement. Cooling towers are used widely in industrial processes for releasing the waste heat arising into environment.
Experimental setup a schematic diagram of the experimental apparatus is shown in fig. Cooling tower performance basic theory and practice subject. In cooling towers with wellengineered mist eliminators, a common design drift rate is 0. Pdf temperature control is a significant requirement in the most industrial process. Compared with the use and waste of city water the water consumption can be reduced with about 90 95%. Experimental study of cooling tower performance using. Pdf a simplified procedure for calculating cooling tower.
Chemical engineering site already published articles on cooling tower components and cooling tower efficiency calculations. Pdf cooling tower performance ngoc son ha academia. They reject process heat from the cooling water to atmosphere and keep the water cool. F o r m u l a s a n d t a b l es formulasandtables fanlaws. Cooling tower calculations cooling water treatment.
Tower coefficient is commonly used to characterized the heat rejection capability of cooling tower. With proper control of condenser water temperature from the cooling tower, up to a 27% increase in efficiency of a central chilled water plant. Cooling tower plays a major role in chemical process industry. To predict andor evaluate the cooling tower performance, many numerical and analytical models have been developed on the basis of heat and. Chemical control of the water in the cooling tower is critical to your cooling system and the tower s integrity. Variations in tower performance associated with changes in remaining parameters are covered in the section on performance curves. Not all cooling towers work for all applications or industrial processes. The lower the approach, the better the cooling tower performance.
Cooling towers are usually designed for specific purposes. In this regard, cooling towers are key parts of many power. Drift loss of the cooling tower is normally provided by the cooling tower manufacturer based on the process design. Student has deep understanding on principles of cooling tower 2. By minimizing cooling tower inefficiency due to turbulent flow. Evaporative cooling is the process where warm water from an industrial process is pumped up to the top of the cooling tower where the water distribution. 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 primary task of a cool ing tower is to reject heat into the atmosphere. The thermal capability of a cooling tower used for air condition ing is often expressed in nominal cooling tower tons.
Experimental the tested cooling tower is a forced draft counter. For example, a cooling tower sized to cool 4540 m3hr through a. The entering air drybulb temperature and relative humidity, talcen independently, have an insignificant effect on thermal verformance of mechanicaldraft cooling towers, but do affect the rate of water evaporation in the cooling tower. Again, this will be a first issue releasing the actual engineering approach. The dryer the air, the greater shall be the performance. 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. The effect of ambient humidity and temperature on the performance of cooling towers employing the merkel and entu methods of analysis are evaluated. How to optimize the energy efficiency of cooling towers. Cooling tower performance and sensors for thermalfluid systems. Chiller performance ratings there are many chiller manufacturers of several com. Understanding key components of cooling towers and.
In this thesis, a new model to predict cooling tower performance is created to give a more accurate picture of the various energy conservation. Evaluate the energy use of the cooling tower, this is mainly the fan and pump horsepower hp. Better cooling tower performance was achieved with optimum operating parameters. 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. An opencircuit cooling tower, commonly called a cooling. In practice, the cooling tower efficiency will be in between 65 to 70%. Drift is defined as liquid water droplets from the recirculating flow entrained in the discharge air stream. Here we explain in full detail how cooling towers operate with example text, pictures, diagrams and principles. 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.
Performance analyses of counterflow closed wet cooling towers. The procedure is then applied to a popular cooling tower model, to illustrate. Cooling tower efficiency calculations chemical engineering site. It is defined as the percentage of water that the tower can cool to the design cold water temperature when the inlet wetbulb, cooling range, water flow rate and fan motor power are all at their design value. Performance analysis of cooling tower international journal of. There are many different types of cooling towers but the cooling tower working principles stay pretty much the same. But cooling towers also pose several problems in their upkeep that closed systems lack. Intent in the foreword of cooling tower fundamentals published by spx cooling technologies, inc. In other words, more power is required than the recommended maximum for the motor. Cooling tower efficiency calculations cooling tower approach. The difference between the cold water temperature cooling tower outlet and ambient wet bulb temperature is called as cooling tower approach. Cooling tower basics calculation formulas cooling tower. Student can calculate effectiveness of the cooling tower, t range, t approach 4. System components include piping infrastructure, valves, pumps, heat exchangers, the cooling tower structure, and cooling.
A cooling tower primarily uses latent heat of vaporization evaporation to cool process water. Creating a new model to predict cooling tower performance and. A schematic illustration and photo of the used experimental apparatus are shown in fig. 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 price performance ratio how much it costs to operate the equipment weighed against with its ability to do its job, or simply called 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. An asdesigned analysis has been performed to quantify the impact of design parameters, expected cooling tower performance, and meteorology on the capacity of watts bar nuclear plant wbn. On the other hand, cooling towers are much larger than tradional hvac systems and are used to remove heat from cooling tower water systems in petroleum refineries, plants, natural gas processing plants, petrochemical plants, and other industrial processes and facilites. Increased power through optimization of cooling tower performance. 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. An opencircuit cooling tower, commonly called a cooling tower, is a specialized heat exchanger in which two fluids air and water are. Most cooling towers work based on the principle of evaporative cooling. The basic cooling tower process is outlined in figure 1. Evapco supports its worldwide customers with manufacturing facilities and. Explanation of cooling and air conditioning terminology for it professionals schneider electric data center science center white paper 11 rev 3 4 amount of moisture from the space and generally do not have the capability to maintain the temperature and humidity parameters specified for it rooms and data centers. For many people in the industry, the thermal performance of cooling towers is often taken for granted. Cooling tower selection and performance is based on water.
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. Cooling tower performance drift thermal science all evaporative cooling products, where air and water come into direct contact, experience some level of drift. Evapco is dedicated to designing and manufacturing the highest quality products for the evaporative cooling and industrial refrigeration markets around the globe. The solution promoting optimum and laminar airflow conditions of the cooling tower can result in a significant. The turbulence causes a limitation of power output, especially during hot summer periods. The evaporative cooler performance is directly related to its ability to evaporate water cool at a given relative humidity. The fanlaws can be used topredi ctthe pe rformance ofa towerwitha nonstandard motor. See the more detailed explanation of cooling towers systems. The approach is the difference in temperature of outlet cold water and ambient wetbulb temperature, t1 tw. The technical data has been taken from a mechanical draft cooling tower. So, for our example drift would amount to approximately 1 gpm. If there is available area, there will be even lower hp cooling tower options that enable a great amount of energy. In the cooling tower industry, this desired temperature is referred to as the cold water temperature due to the fact that it is cooler than water entering the tower.
1485 286 537 250 1301 1120 98 1534 627 1352 1171 728 970 622 1168 1124 670 175 1033 1238 1020 135 622 308 1118 980 1458 1391 1423 1336 11 1348 104 80 1015 1280 1232 1457