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. Department of energy building energy codes program. The method allows analytical calculation of cooling tower. Cost effectiveness assumptions in the example above, annual energy use and annual water use are based on ari standard 8102003 for a watercooled, imhtype model with an ice harvest rate of 450 pounds per 24 hours. The defining measurement for cooling tower operations measuring outdoor wetbulb temperature helps operate cooling towers for peak efficiency. 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. 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. 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. If you read this book carefully, you can make any cooling tower design programs by yourself. Cooling tower selection wrong hvacr engineering eng. Introduction an open circuit or evaporative cooling tower is a heat rejection device that rejects heat to the atmosphere by cooling a water stream to a lower temperature. Test your knowledge on cooling tower online quiz chemical. The cooling tower test is conducted in reference with cti code atc 10500, schedule ii performance curve method.
The purpose of a cooling tower is to keep a process from raising temperatures too high were they either can be dangerous or lower the efficiency. Cooling tower makeup water calculation xls saubhaya makeup. The purpose of this test procedure is to describe instrumentation and procedures for testing and performance evaluation of cooling towers. Evapco is dedicated to designing and manufacturing the highest quality products for the evaporative cooling and industrial refrigeration markets around the globe. Cooling tower efficiency calculations cooling tower efficiency calculation is described in this article. Water efficiency management guide mechanical systems. By using a cooling tower, the plant is kept safe and operational. When evaporative cooling can occur is based on local environmental variables that can. The fanlaws can be used topredi ctthe pe rformance ofa towerwitha nonstandard motor.
If not already known, determine the value of water used in your cooling towers and evaporative condensers. F o r m u l a s a n d t a b l es formulasandtables fanlaws. High walls will create an artificially warmhumid environment from recirculating moist discharge air. Supporting information report cooling tower feed water. Dear sirmadam, we are in the process of calculating cooling tower duty. Again, this will be a first issue releasing the actual engineering approach.
Following items will be discussed and calculated in this article. The compressors are most often driven by electric motors, although they can also be powered by natural gas engines or steam turbines. This amount of heat could theoretically melt 1 ton of ice in 24. Filtered water is then pumped back into the main condenser line through a nozzle or returned to the cooling tower basin called the sump. Technical evaluation of side stream filtration for cooling. The cooling tower test is conducted in reference with cti code atc 10500, schedule ii. Cooling tower selection 5 unit layout 6 cooling tower piping 7 cooling tower accessories 8 iii. For nearly a century, we have provided exceptional quality equipment and service to the hvac, process cooling, industrial, and refrigeration markets. 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.
Process leaks, windage, and drift are really just forms of uncontrolled blowdown. Cooling load calculations and principles ced engineering. Cooling tower performance in free cooling applications is dependent upon both the system and cooling tower design. Each cad and any associated text, image or data is in no way sponsored by or affiliated with any company, organization or realworld item, product, or good it may purport to portray. Drift eliminators are installed to prevent water entrained in the air from leaving the system. You should confirm all information before relying on it. 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. Calculations 417 cooling tower blowdown equation by james mcdonald, pe, cwt originally published.
Nov 25, 20 cooling tower evaporative cooling is achieved by the evaporation of a small fraction, about 1 to 2%, of the recirculating water flow. This may be a case of a refrigerant ton 12,000 btuhr vs a cooling tower ton 15,000 btuhr. A neglected or poorly maintained cooling tower can. Assessing the performance of cooling towers and their effect. It allows you to quickly calculate the total required cooling and heating loads in btuhr or. These calculations reinforced the concept that molybdenum from cooling tower discharges are a significant source of the mo in the pellets. Evaporation rate gpm water flow rate gpm x range f x 0. Vapor compression chillers use reciprocating, screw, or centrifugal compressors to power the cycle. The present paper is a detailed methodology for thermal design of cooling tower. 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. Best practice guidelines water conservation in cooling towers au 1. Cooling towers are used as part of industrial hvac systems to remove heat from process water by evaporative cooling. Ideally tower should be raised so the discharge meets the height of the walls as a minimum.
Other factors, which we will see, must be stated along with flow rate m3hr. In either case, whether caused by nature or by the tower itself, the owners concern for an ice formation on a cooling tower should be a reflection of both its location and its amount. Cooling towers can be split into two distinct categories. The towers essentially a cooling tower is a type of heat exchanger. 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. K overall enthalpy transfer coefficient, lbhft2 a surface area per unit tower volume, ft2ft3 v effective tower volume, ft3 l water mass flowrate, lbh equation 2 basically says that at any point in the tower, heat and water vapor are transferred into the air due approximately to the difference in the enthalpy of the air at the surface of the water and the main. Cost effectiveness assumptions in the example above, annual energy use and annual water use are based on ari standard 8102003 for a watercooled, imhtype model.
The marley nc cooling tower has set the standard for high efficiency and low maintenance since its introduction in 1968. Energy performance assessment of hvac systems bureau of energy efficiency 117 first calculate the kwton rating from the measured parameters. Cooling tower calculations xls free software download. Guidelines for estimating unmetered industrial water use. Design of mechanical draftcooling tower and determination of. Full hvac training course by ramy ghoraba pdf files. Combined heat and power technology fact sheet series. Cooling tower efficiency calculations cooling tower approach. The tower takes the heat from the water stream and rejects it to.
Its role is to remove heat from a process, usually either a direct manufacturing process or from the condenser of a chiller. For nearly a century, we have provided exceptional quality equipment and service to the hvac, process cooling, industrial, and. The mass balance around a cooling tower as illustrated in the figure to the right is. Nov 30, 2016 chemical engineering site already published articles on cooling tower components and cooling tower efficiency calculations. 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. Best management practice and guidance manual for cooling. Multiply the evaporation rate by the appropriate correction factor in the table below to calculate the makeup water. Reducing water use in cooling towers and evaporative condensers. The technical data is taken for mechanical draft cooling tower.
Cooling tower basics calculation formulas cooling tower. Introduction to commercial building hvac systems and energy code requirements reid hart, pe, pacific northwest national laboratory u. The fire protection system should be designed on a rate of application basis as follows. Under fan decks of counterflow towers an aver age water density of 0. Some parameters of the column operation are then calculated.
Cooling tower makeup water calculation pdf saubhaya makeup. See figure 1 on page 3 for an illustration of the water being recirculated, added to, or lost from a cooling tower. They reject process heat from the cooling water to atmosphere and keep the water cool. Necessary considerations when proposing a cooling tower. 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. Hi there, im involved a project where i must determine the power requirements of a forced draft cooling tower that uses a large fan. Calculating fan power involved for a cooling tower student. Cooling tower calculations in excel free downloads 2000 shareware periodically updates software information and pricing of cooling tower calculations in excel from the publisher, so some information may be slightly outofdate. Cooling tower plays a major role in chemical process industry. Cooling tower calculations in excel free download at. The remainder of this report will explain the theory behind the operation of a cooling tower and how the laboratory cooling tower is operated. Range range is determined not by the cooling tower, but by the process it is serving.
Evaporation losses e it is calculated on the basis of heat. A suite of cooling tower applications that is indispensable to anyone responsible for the peak performance of cooling towers. The evaporation rate is approximately 2 gpm per 1 million btuhr of heat rejection. This includes determination of cycle of concentration, evaporation loss, drift or windage loss, blow down water requirement makeup. For example, a cooling tower sized to cool 4540 m 3hr through a. The recirculation rate and the temperature drop across the cooling tower are the two pieces of data needed to calculate the amount of water lost from the open recirculating cooling system due to evaporation. Tonnage duty calculator flow gallons per minute hot water temperature f. The estimated mass of mo from cooling towers alone 18 lbsday exceeded the mahl. Key features lowered required height, which reduces the need for architectural screening. Evapco supports its worldwide customers with manufacturing facilities and sales offices. Latent heat gain is the energy added to the space when moisture is added to the space by means of vapor emitted by the occupants, generated by a process or through air infiltration from outside or adjacent areas. In open circuit systems the recirculating water returns to the tower after 1 one ton of refrigeration is equal to 12,000 btuhour. F can increase efficiency of the chiller compressor by 1% to 2 % in most situations.
Cooling tower selection wrong hvacr engineering engtips. Cstn july 2003 l et s take a look at how to calculate cooling tower blowdown. This app performs ruleofthumb hvac cooling and heating load calculations for many types of commercial, industrial, institutional, and residential buildings. Our nearly 100 years of cooling tower engineering knowhow is utilized so that the nc cooling tower you select today provides the broadest range of configurations and the highest cooling capacities available in a package.
Cooling tower makeup water flow calculation rea hvac. A survey of wet cooling tower literature was performed to develop a simplified method of cooling tower design and simulation for use in power plant cycle optimization. The industry decided many moons ago to match the nominal capacity of cooling towers to the nominal capacity of water cooled chillers, this having a 450 ton chiller matched with a 450 ton cooling tower. Calculate a ton of cooling load using this formula. Section 1 laboratory data data from the laboratory data sheet are entered into the spreadsheet in the same order as they appear on the data sheet. Reducing water use in cooling towers and evaporative. How to calculate tons of cooling for a cooling tower sciencing. Cooling tower spreadsheet details details of the excel spreadsheet are presented here. Get back to your priorities and minimize maintenance requirements with highquality marley replacement components for nonmarley towers.
Based on the project zip code and site design factors, calculations are made to determine the equivalent seismic g force and wind load in pounds per square foot psf on the unit. Cooling tower calculations in excel free downloads, list 1 download cooling tower calculations in excel software. The defining measurement for cooling tower operations. Isolated platform for cooling tower save up to 40% installed cost over traditional approaches contact us, your local vibroacoustics representative, for a quotation and to see how this isolated platform solution can save you time and significant cost. As an alternative you can duct the discharge away from the enclosure, however this adds static pressure which needs to be. The evaporation rate is approximately 3 gpm per 100 tons of refrigeration. Understanding key components of cooling towers and. Isolated platform for cooling tower vibroacoustics. The merkel equation the fundamental equation of heat transfer in wet cooling towers is presented and discussed. The computeraided design cad files and all associated content posted to this website are created, uploaded, managed and owned by third party users. Cooling tower efficiency calculations chemical engineering site. The theory of heat exchange in wet cooling towers is briefly summarized. Calculating the tons for a cooling tower requires you to understand some basic information about it works. Cooling tower performance calculations are usually performed numerically.
Calculation of effect of cycles of concentration on amount of. Maintaining water chemistry is an essential part of an effective. However, it is possible to lessen this impact in both central and unitary systems by increasing their efficiency. Additionally, water is lost from any system leaks and tower drift escape of water droplets from the cooling tower structure as a result of system air flow and windeffect air flow. Assessing the performance of cooling towers and their.
Whether we have to consider cooling tower capacity same as that of cooling tower circulating pump capacity or we should omit the flow rates of ssf side stream filter. Tradional hvac heating and cooling systems are used in schools, large office buildings, and hospital. Mar 18, 2009 calculating fan power involved for a cooling tower posted in student. 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. Indoor and outdoor criteria for heating and cooling load calculations g. Replace the chaos of disconnected, unorganized files, folders, and spreadsheets with streamlined, automated data housed in perpetuity. Marley nc cooling towers and cooling tower parts spx. Introduction to commercial building hvac systems and. After the water has been chilled, it is distributed via pumps, pipes, and valves the distribution system to the loads, where a heat exchangerfor example, a cooling coil in an airhandlertransfers heat from the air to the chilled water, which is returned to the chiller. Cooling tower with side stream filtration examples technology characterization side stream filtration systems continuously filter a portion of cooling water to remove debris and particles. Department of energy assistant secretary for resource. Cooling tower evaporative cooling system measurement. 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. An example of a mass and energy balance on the laboratory cooling tower will be presented along with the results of experiments in which the rate of heat dissipated by the tower was calculated at full.