There are also counterflow towers that use forced draft. Cooling water systems an overview of cooling towers 2012 instructor. Cooling tower design and construction designing buildings. 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. For specific information on how cooling tower products can meet your cooling tower needs, contact your local cooling tower products representative or give us a call today at 8007331584.
Department of energy assistant secretary for resource. Most cooling towers work based on the principle of evaporative cooling. Fundamentals handbook, chapter 26, represents the entering air wet bulb. To reduce the drift from cooling towers, drift eliminators are usually incorporated into the tower design to remove as many droplets as practical from the air stream before exiting the tower. A cooling tower is a device used in industry to cool hot water by partial evaporation before reusing it as a coolant. Today, multicell cooling tower configurations have common headers for both the supply and return lines figure 2. A water legged discharge or discharge reducer will provide automatic siphon draw establishment so long as minimal startup flow velocity in the downcomer is to the order of 1 ft. Often several materials are used for corrosion resistance, reduce maintenance, increase reliability and more service life. The most common is for a cooling tower that provides the required heat rejection capacity with a high level of reliability at low cost. The technical data is taken for mechanical draft cooling tower.
The following design data is required to select cooling towers. Cooling tower calculations software program is a powerful, user friendly, software program for the analysis of induced, mechanicaldraft, counterflow cooling towers. Nov 22, 2014 there are many design guideline to assist engineers to understand the basic principles of cooling towers. Design of mechanical draftcooling tower and determination of. There are many design guideline to assist engineers to understand the basic principles of cooling towers. C constant related to cooling tower design m slope of tower characteristic curve 1 liquidtogas ratio lg. The software program can be used for the analysis of existing towers or for the preparation of specifications for new towers. If you are still getting your bearings with cooling tower design terminology, you may wonder what the terms approach and range mean. Mar 01, 2016 properly engineered condenser, chiller and cooling tower piping and controls will improve heat transfer and avoid problems such as air slugging and pumps losing prime. The makeup water source is used to replenish water lost to evaporation. It is intended that each potential trouble source be evaluated so that the necessary design safeguards can be erected against. At these condi tions, the cooling tower rejects 15,000 btuih per nominal cooling tower ton.
Cooling tower manufacturer heat exchanger manufacturer india. How cooling towers function introduction most industrial production processes need cooling water to operate efficiently and safely. Design master hvac is an integrated hvac building design and drafting program for autocad. 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. There is also the option of counterflow and crossflow design there also exists cocurrent flow but it is seldom used. The selection of the right cooling tower for your application can be summarized as follows. Cooling tower design jc cooling tower design basics cooling tower design calculations we having 23 years in the field of cooling tower manufacturing and design.
Cooling tower basics calculation formulas cooling tower. The water falls and collects in a pond at the base of the tower, formed by a base slab and the pond wall. The program can be used for the analysis of existing towers or for the preparation of specifications for new towers. The present paper is a detailed methodology for thermal design of cooling tower. Pdf industrial cooling tower design and operation in the. It is the requirement of heatenergy to increase the temperature by 1of of onepond of water between 32 and 212of.
Use an economical approach difference between water outlet temperature and design wet bulb of 4 c. Part i outlines the steps necessary to improve cooling tower operations including a simple checklist for easy reference. We offer cooling tower services in arizona but can ship cooling tower parts worldwide. Cooling tower basics calculation formulas cooling tower efficiency in this article explained about basic concepts of cooling tower, types of cooling towers, formula for cooling tower efficiency. See the more detailed explanation of cooling towers systems.
Cooling towers have certain design values, but seasonal variations require adjustment and tuning of water and air. In naturaldraught cooling towers the open structure at the base allows a natural movement of air. The merkel equation the fundamental equation of heat. We are a nonprofit group that run this website to share documents. Lack of tower treatment with consequent fouling of the condenser. The thermal capability of a cooling tower used for air condition ing is often expressed in nominal cooling tower tons. 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. Cooling tower efficiency calculations cooling tower approach. Fundamentals of heat and mass transfer in wet cooling towers.
Range range is determined not by the cooling tower, but by the process it is serving. For purposes of comparison, a real tower is considered in the current study as the reference design tower. If it is not available it may be assumed as for natural draft cooling tower d 0. Galvanized steel, various grades of iron and stainless steel, and concrete are widely used in tower construction. Nassef optimum shape and design of cooling towers m. Other factors, which we will see, must be stated along with flow rate m3hr. Tradional hvac heating and cooling systems are used in schools, large office buildings, and hospital. The cooling system is housed in the towers base which is typically the bottom 10 metres, the rest of the tower consisting of an empty shell. The fill is contained within a counterflow tower since the air is drawn up and through the failing water. Cooling tower analysis is a powerful, user friendly, program for the analysis of induced, mechanicaldraft, counterflow cooling towers. The merkel theory overcomes this by combining the two into a single process based on enthalpy potential. It is based on around fortyfive years of experience in the construction of cooling towers gained by plant and structural design engineers, by construction companies, checkup engi. Midwest cooling towers experienced cooling tower engineering and design group can offer you the best value option for your particular application, whether it is one of preengineered cooling towers, or a custom designed solution. Lets look at a typical case of fan selection for a new tower design.
Cooling tower structures vary greatly in size and design, but they all function to provide the same thing. It provides the base of the selection in cooling tower. In this design the fill is located outside the tower. Again, this will be a first issue releasing the actual engineering approach.
Cooling tower useful terms and cooling tower performance. Cooling water systems an overview of cooling towers. However, because of the evaporation that takes place within the tower, the mass flow of water leaving the. Keywords cooling tower, thermal design, different types of losses introduction a cooling tower is a semienclosed device for evaporative cooling of water by contact with air. Considered will be a 26 ft, 28ft, or 30 ftdiameter fan. While the mathematics of cooling tower flow design can be. Features include 2d and 3d ductwork drafting, ductwork sizing, pressure drop calculations, and building load calculations. Cooling towers are a very important part of many chemical plants. 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 water exits the cooling tower and is sent back to other units for further process conditions. Drift eliminators are installed to prevent water entrained in the air from leaving the system. Phd thesis wetcooling tower thermal performance evaluation. This online engineering pdh course provides comprehensive information on cooling water systems and describes different types of cooling towers, their mechanical components and the problems associated with cooling water.
If you read this book carefully, you can make any cooling tower design programs by yourself. Buy marley 6 water distribution nozzles nx crossflow nozzle n a truly clogresistant crossflow nozzle n nozzles are spaced on nominal 20 centers n 1. For example, a cooling tower sized to cool 4540 m 3hr through a. Cooling tower pumping and piping baltimore aircoil company. Here we explain in full detail how cooling towers operate with example text, pictures, diagrams and principles. The type of heat rejection in a cooling tower is termed evaporative in that it allows a small portion of the water being cooled to evaporate into a moving air stream to provide significant. Understanding the basics of cooling tower heat transfer. The lg ratio of a cooling tower is the ratio of the liquid water mass flowrate l to gas air mass flowrate g. Like most other hvac equipment, the commissioning of cooling towers starts during design and continues on through construction, start.
The effect of climatic changes is shown to be important in the design of more effective cooling technique and to device methods to compensate for the loss in plant efficiency. The commissioning of cooling towers 2 prime and paint the condenser water piping, cooling tower structural steel, and other exposed metals to ensure long life and a neater appearance. Some of the commonly used useful terms, in the cooling tower industry are btu britishthermalunits. A nominal cooling tower ton is defined as cooling 3 gpm of water from 95f to 85f at a 78f entering air wetbulb temperature. The cooling load is determined by the size of a building from which heat needs to be extracted. These towers are basically used to remove excess heat that is generated in places such as power stations, chemical plants and even domestically in air conditioning units, and are relatively inexpensive and a dependable means of removing lowgrade heat from cooling water and have developed. 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. The theory of heat exchange in wet cooling towers is briefly summarized. Checklists for design, construction, and startup by davesellers, pe, senior engineer, portland energy conservation inc.
Cooling tower efficiency guide property managers improving cooling tower operations how to use this guide this guide is structured in two parts. A cooling tower is a heat rejection device, which extracts waste heat to the atmosphere though the cooling of a water stream to a lower temperature. These studies were complicated by the fact that the cooling tower market is typically driven by one of two powerful, yet often conflicting requirements. Houston, texas fans key to optimum coolingtower design nomograph gives the reciprocal of the density ratio. Cooling is accomplished through the latent heat of vaporization. They represent a relatively inexpensive and dependable means of removing low grade heat from cooling water. Cooling towers continuing education for professional engineers. Cooling tower mass balance gives an idea about make up water requirement. This derives from the fact that a btu british thermal unit is the amount of heat gain or loss necessary to change the temperature of 1 pound of water by 1 f. There are many different types of cooling towers but the cooling tower working principles stay pretty much the same. Cooling towers continuing education for professional. 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. These towers are basically used to remove excess heat that is generated in places such as power stations, chemical plants and even domestically in air conditioning units, and are relatively inexpensive and a dependable means of removing low. Tower components from a variety of different materials.
Houston, texas fans key to optimum cooling tower design nomograph gives the reciprocal of the density ratio. 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. Cooling tower design software free download cooling. The basics of wet cooling towers back to news water cooling towers are some of the most essential pieces of equipment for commercial and industrial buildings today. Multicell cooling tower configurations that have 100 percent independent systems have limited redundancy. Frame and casing, fill, cold water basin, drift eliminators, air inlet, louvers, nozzles and fans. 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. It is the temperature difference between cooling tower entering hot water and leaving. Determination of optimum height for counter flow cooling. Cooling tower fundamentals spx cooling technologies. Download cooling tower design we are a sharing community.
It is a wooden, steel or concrete structure and corrugated surfaces or baffles or perforated trays are provided inside the tower for uniform distribution and better. 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. In these systems, the use of automatic control valves for proper operation is imperative at the. Cooling tower thermal design manual the early investigators of cooling tower theory grappled with the problem presented by the dual transfer of heat and mass. Range of cooling in f t1 t2 area wet bulb temperature in f twb the design heat load is determined by the flow rate, and the range of cooling, and is calculated using the following formula. Design of mechanical draftcooling tower and determination. Introduction a cooling tower is a heat rejection device that.