Theory the cooling tower experiment operates according to the first law of thermodynam ics which is the conservation of energy. Fundamentals of hvac controls the application of heating, ventilating, and airconditioning hvac controls starts with an. Fredrick merkel 1925 proposed a theory relating evaporation and sensible heat transfer where there is counterflow contact of water and air, such as in cooling towers. Theory cooling tower terms cooling range the difference between the water temperature at entry to and exit from the tower. 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.
Determination of optimum height for counter flow cooling tower. The basic cooling tower process is outlined in figure 1. Considered will be a 26 ft, 28ft, or 30 ftdiameter fan. A simplified thermal modelling of cooling tower for. In the wl 320 open wet cooling tower, water is sprayed into the tower from above and distributed as widely as possible using baffles. Here we explain in full detail how cooling towers operate with example text, pictures, diagrams and principles. The tower thats placed in apparathallen in kemicentrum was investigated and used as a base for the model. Again, this will be a first issue releasing the actual engineering approach.
Thermal testing of cooling tower testing of cooling tower is an intricate process. The makeup water source is used to replenish water lost to evaporation. The high exiting air velocities reduces the chance of re circulation. In this type of cooling tower, fan is used to circulate the air.
Experimental the tested cooling tower is a forced draft counter. Energy saving opportunities in cooling towers follow manufacturers recommended clearances around cooling towers and relocate or modify structures that interfere with the air intake or exhaust. Cooling towers can be split into two distinct categories. For nearly a century, we have provided exceptional quality equipment and service to the hvac, process cooling, industrial, and refrigeration markets. Amazing laptop cooling wizard software can quickly cool down your laptop cpu temperature within minutes and reduce the notebook fan noise. Optimise cooling tower fan blade angle on a seasonal andor load basis. They represent a relatively inexpensive and dependable means of removing low grade heat from cooling water. Intent in the foreword of cooling tower fundamentals published by marley cooling technologies, inc. In hvac environments towers are typically used to remove heat from a chiller. During this process, it is exposed to airflow that is forced, induced, or naturally drafted into the tower.
F o r m u l a s a n d t a b l es formulasandtables fanlaws. 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. Your theory is that as the water sprays into the droplets will the towerhit the pipes like a ball draining a pinball down machine. Set the tower to the following suggested conditions. The tower takes the heat from the water stream and rejects it to. The above equipment andor systems integral to them are complete and ready for functional testing, except as noted. With the addition of steel fill series v cooling towers are also ideal for high temperature applications. The merkel equation the fundamental equation of heat. The technology evaluation assesses side stream filtration for cooling towers.
Concrete structured cooling towers low maintenance a concrete structural tower requires minimum structure maintenance. 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. Cooling tower performance basic theory and practice subject. Cooling tower efficiency calculations cooling tower efficiency calculation is described in this article. Abstract this experiment was conducted to perform energy and mass balance on the cooling tower system and to observe the effects of one of the process variables on the exit temperature of water. This section provides an introduction of cooling tower designs. Still, the cooling tower isnt the most grievous energy consumer in a chilled water system. Over the operating temperature range of the cooling tower, c p is almost constant at 4. Cooling tower performance basic theory and practice. Not only will the flow of water be slowed thereby increasing its contact time with the. A read is counted each time someone views a publication summary such as the title, abstract, and list of authors, clicks on a figure, or views or downloads the fulltext. Cooling towers are a very important part of many chemical plants. They reject process heat from the cooling water to atmosphere and keep the water cool.
Tradional hvac heating and cooling systems are used in schools, large office buildings, and hospital. An improved cooling tower algorithm for the cooltoolstm. Energy can neither be created nor destroyed, just transformed from one form to another. Both types function as heat exchangers based on the counter flow principle. Cooling towers have certain design values, but seasonal variations require adjustment and tuning of water and air flowrates to get the best cooling tower effectiveness. Rp m 2 rp m 1 cfm 2 c fm 1 staticpressure 2 static pressure 1 cfm 2 cfm 12.
Cooling tower pdf freeware pdf to word converter v. 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. Cooling towers induced draught vs forced posted in industrial professionals. Department of energy assistant secretary for resource.
Finally, outside air is drawn across the cooling tower, removing the heat from the water through the process of evaporation. System economics are also discussed, providing an example project with lifecycle. The purpose is to define a preventive maintenance program and plan for cooling towers at the suny polytechnic quad c building utica new york. The specific enthalpy of saturated water vapor steam can just be looked up.
The fanlaws can be used topredi ctthe pe rformance ofa towerwitha nonstandard motor. Cooling towers induced draught vs forced industrial. A cooling tower reduces the water temperature close to a. Cooling tower efficiency calculations cooling tower approach. All standards initiated after the date of this manuals adoption shall use this manuals described methodology.
Cooling tower installation civil work conventional approach tower tech approach cheapest cooling tower cost arrives fully assembled smallest footprint possible 50% less weight and height fewest cells possible bottom vs. Cooling tower info pdf, delta cooling towers india your. Cooling technology institute cti shall be followed to obtain approval from concept through adoption. Amazing laptop cooling wizard allows you to prevent your laptop, notebook from overheating due to many reasons including playing games, dated laptops and running several programs at the same time on windows xp7810. When power plant runs on peak load, it requires a very high rate of cooling water. The data from the work can also be used in other courses where the equipment is studied. The main part of the installation is the cooling tower. Ccs designs the tower internals to the highest quality and long life standards, thus providing a permanent, long life, minimum maintenance cooling tower. Reducing water use in cooling towers and evaporative. If the circulating water has four times the solids concentration than that of the make up water, then the cycles are 4. Hot water from the chiller is sent to the top of the cooling tower where it is released into the tower. The evaluation provides a characterization of side stream filtration technology, describes typical applications, and details specific types of filtration technology.
The water is sprayed down to the basin or through a heat exchange. Im looking to purchase cooling towers for a project and have no experience of selection type. Cooling tower replacement va pittsburgh page 1 of 5 hfl no. Flow theory merkel equation figure 1 illustrates a drop of water falling through an upstream of unsaturated air at a wet. Simulation of a counterflow and crossflow cooling tower by. 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 towers theory software free download cooling. Equipment id 8ct3 building chiller plant location roof. Questions from the floor at our annual conference and answered by a leading panel of experts within the cooling tower industry. For water cooling tower experiment, there are several parameters that can be adjusted to observe its effects on the evaporation of water. Working principle is same as natural draught cooling tower, only difference is that here fan is mounted on the cooling tower. A schematic illustration and photo of the used experimental apparatus are shown in fig.
Houston, texas fans key to optimum coolingtower design nomograph gives the reciprocal of the density ratio. Induced or forced my scheme involves a cooling capacity of 3560 kw cooling water, a maximum 66 deg c to 22 deg c in a wet bulb temp 19 deg c. The hybrid cooling tower is a compromise between the wet and the dry cooling tower. Doc cooling tower lab report sem yong hao academia. Lab 1b cooling tower performance and sensors for thermal. A cooling tower is a specialized heat exchanger in which two fluids air and water are brought into direct contact with each other to affect the transfer of heat. Cooling tower plays a major role in chemical process industry. Before proceeding check the make up level of the water, and add water as needed to bring the level back to the level at the start of the cooling tower operation in step 2.
The thermal capability of a cooling tower used for air condition ing is often expressed in nominal cooling tower tons. Drift eliminators are installed to prevent water entrained in the air from leaving the system. Cooling tower selection 5 unit layout 6 cooling tower piping 7 cooling tower accessories 8 iii. A schematic illustration and photo of the used experimental apparatus are shown in. Series v cooling towers offer a wide range of capacities, minimal sound levels, low installation costs, yearround operating reliability, and are easy to maintain. K adv t t a1 convective mass transfer of water vapour from saturated air film to the air stream.
The basin is that portion of the cooling tower structure located under the tower that is used for collecting cooled water and which can be used as a location for adding makeup water. 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. Amazing laptop cooling wizard allows you to prevent your laptop, notebook from overheating due to many reasons including playing games, dated laptops and running several programs at the same. The cooling is caused only by the heat exchange or convective cooling.
The drop ofwater is assumed to be surrounded by a film. Cooling tower pdf freeware free download cooling tower pdf. To rotate fan, it uses motor with speed around rpm. Cooling towers theory software free download cooling towers. Correct excessive andor uneven fan blade tip clearance and poor fan balance. Cooling load the rate at which heat is removed from the water. If you read this book carefully, you can make any cooling tower design programs by yourself. Makeup the quantity of fresh water which must be supplied to the water circuit. We have two theories, with the first one stating the o 2 is electrochemically reduced by kdf media to form water. Langenhoffb ainstitute for biodiversity and ecosystem dynamics ibed, university of amsterdam, amsterdam, the netherlands.
There is no evaporation in dry towers since there is no direct contact of water and air. Drift water droplets that are carried out of the cooling tower with the exhaust air. Poreward ii abstract ill list of tables viii list of figures xi introduction 1 natural draft cooling towers. 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. Typical closed loop cooling tower system is shown in figure 7. Cooling tower types cooling towers fall into two main categories. However, cooling towers and evaporative condensers require significant quantities of makeup water to compensate for losses associated with evaporation, drift or mist and blowdown or purge. There are principally two kinds of cooling towers, dry and wet. Doc towers, but corrosion coupons in kdf redox treated cooling water indicate well below the expected levels of corrosion where is all this dissolved oxygen going. The ratio of dissolved solids in circulating water to the dissolved solids in make up water is called a. Different tower selections can afford opportunities.
The lg ratio of a cooling tower is the ratio of the liquid water mass flowrate l to gas air mass flowrate g. The hybrid cooling tower can serve not only as a dry heat exchanger but also as a wet cooling tower. At these condi tions, the cooling tower rejects 15,000 btuih per nominal cooling tower ton. See the more detailed explanation of cooling towers systems. The water exits the cooling tower and is sent back to the exchangers or to other units for further cooling. 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.
In open circuit systems the recirculating water returns to the tower after 1 one ton of refrigeration is equal to 12,000 btuhour. Simulation of a counterflow and crossflow cooling tower by the stepwise integration method montri pirunkaset abstract the stepwise integration method is an approximation method for determining the water temperature in the fill layers for a counterflow cooling tower and in the fill cells for a crossflow cooling tower. Induced draft towers are typically mounted with a fan at the top of the cooling tower, which allows hot air out and pulls air throughout. Earlier models focus mostly on developing a static solution for how the cooling tower will act at specific instances, but reality is not static.
Cooling tower heat transfer fundamentals power engineering. In the words of an excellent reference manual on cooling, evaporation is utilized to its fullest extent in. Water may also be used in ancillary feedwater treatment processes, such as softening. Hidden costs reducing water consumption in cooling towers and. The theory of heat exchange in wet cooling towers is briefly summarized.
As this occurs, a small volume of water is evaporated, reducing the temperature of the water being circulated through the tower. Experimental study of cooling tower performance using ceramic. Merkel made several simplifying assumptions that reduce the governing relationships for a counterflow cooling tower to a single separable ordinary differential. 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. Objective to study the performance at different ranges cooling load and inlet temperature of cooling tower. Series 3000 and xeseries cooling towers should be rigged and assembled as outlined in this bulletin. Nov 15, 2014 the remainder of this report will explain the theory behind the operation of a cooling tower and how the laboratory cooling tower is operated. Cooling towers with open and closed water circuits are available.
Theory the cooling tower experiment operate according to the first law of thermodynamics which is the conservation of energy. Walker 22 proposed a basic theory of cooling tower operation. All existing standards that are reaffirmed, revised, or withdrawn after adoption of this manual shall follow the. Experimental study of cooling tower performance using. However, because of the evaporation that takes place within the tower, the mass flow of water leaving the. Best practice guidelines water conservation in cooling towers au 1. Vt1 counterflow cooling towers can be used in indoor and outdoor applications. Most cooling towers work based on the principle of evaporative cooling.
It is an exercise to compare the performance of a working cooling tower to the design parameters on which it was offered. 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. Cooling water systems an overview of cooling towers 2012 instructor. Industrial cooling towers are used to remove surplus heat from water. Cooling water systems an overview of cooling towers. The hybrid cooling tower is a combination of the advantages of a wet and a dry cooling tower. 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. Establishment of the approach fixes the operating temperature of the tower and is a most important parameter in determining both tower size and cost. 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. Understanding key components of cooling towers and. More precise values can be obtained by looking at the charts. The purpose of this document is to assist the purchaserconsultant in effectively sizing, selecting and evaluating a particular cooling tower. In our project we are going to design circular cooling tower named as induced draft cooling tower. Lets look at a typical case of fan selection for a new tower design.