Its characteristics also has easy maintenance, low noise of water pressure and smaller floor space with long term use. The water is collected in a flash box for equal distribution and then it is recirculated once it collects at the bottom in the basin. Cooling tower market evaporative cooling tower dry cooling tower. Pdf cooling tower is one of the key components of a largescale water cooled condenser based airconditioning system, whose efficiency. Technical reference for water conservation in cooling towers pub. Conductivity trend for manual or timed blowdown control. Annual fan electrical energy requirements are calculated for towers with singlespeed, twospeed, and variablespeed fans. This heavyduty cooling tower designed of noncorrosive materials is energy efficient and its cross flow design offers ease of maintenance. Induced draft cooling tower have the ability to handle large water flow rate than forced draft cooling tower 2. Which type of cooling tower is more efficient, cross flow or. Again, this will be a first issue releasing the actual engineering approach.
Janssen, operational and engineering director wacon international ltd. I know the inlet and outlet temperature of water, volume flow rate of water and the heat load desired from the cooling tower. Advantage of cross flow cooling tower industrial cooling towers that run on water are manufactured in different designs and configuration. Warm water from the heat source is pumped to the top of the tower and then flow down through plastic or wooden shells.
Gravity systems, employed on bacs crossflow cooling towers, feature hot water basins mounted on top of the tower above the fill. Cooling towers employ either gravity distribution or pressurized spray systems to distribute water over the fill. The thermal capability of a cooling tower used for air condition ing is often expressed in nominal cooling tower tons. At these condi tions, the cooling tower rejects 15,000 btuih per nominal cooling tower ton. Counter flow cooling towers are fitted with an induced draught fan on the top and are directly mounted on the motor.
Inquiry documents should define the owners plan for. Together with the dosing pumps and the provided accessories, they are designed to guarantee the correct and efficient treatment of water flow in a cooling tower. Tower location location of the cooling tower must follow these guidelines. Warm, moist air, which is more dense than cool air, will naturally rise through the tower, while the dry, cool air from outside will fall, creating a constant cycle of air flow. Cooling tower overview the primary task of a cooling tower is to reject heat into the atmosphere. The air flow enters the vertical faces of the equipment and through which the water flows down by gravity to. 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. Heated air blows across the grain as it flows by gravity down an 8. The double cross flow cooling tower operates according to the cross flow principle. In cross flow induced draft towers, the water enters at the top and passes over the fill. Winter operation considerations for open cooling towers. As a result, the speed of exhaust air is much higher than the air that enters. A fully labeled induced draft double cross flow cooling tower. Cross flow of air continues through the fill and thus past the water flow into an open plenum volume.
These towers usually feature gravityfed water distribution. Cooling tower market by application, product, design and. The exs series cooling towers are specifically designed to meet maximum performance and reliability, and minimum maintenance. Simulation of a counterflow and crossflow cooling tower by. Irregular rotation of distribution pipes 4 improper flow of air 5. Cooling tower film fills for counterflow systems brentwood. Cross flow vs counter flow cooling tower which one is. This correlation formed by using a pilot study of cross flow cooling tower with nominal capacity of 90kw and grt package polypropylene grid fill block. Rise in cooling water temperature abnormal water flow noise and vibration excessive current water carry over table adjustme excessive or inadequate cooling water flow irregular flow of air 2. An induced draft fan draws the air across the wetted fill and expels it through the top of the structure. Series 10 cooling towers are field constructed, splash fill, crossflow wood cooling towers, designed to serve all normal cooling water systems as well as those dirty water systems which would place the long term operation of a filmfill tower in jeopardy.
The fire protection system should be designed on a rate of application basis as follows. Range range is determined not by the cooling tower, but by the process it is serving. In a counter flow cooling tower, water sprays are used to distribute the warm water see figure 8. Cross flow type maintenance free frp cooling tower first time in india, varun has introduced and designed thecross flow type maintenance free frp cooling tower with fit and forget technology. Hi, i am an engineering student, and i am working on a cross flow induced draft cooling tower. At least 3 feet of space shall be allowed on each access door side for crossflow towers and the minimum calculated clearance on all sides of counterflow towers, based on required intake area refer to mesans. A cooling tower is a heat rejection device that rejects waste heat to the atmosphere through the.
The high thermal performance and low pressure drop are balanced by utilizing the engineered microstructure design. For example, a cooling tower sized to cool 4540 m 3hr through a. 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. 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. However, it requires large size compared with existing counter flow tower. Midwest cooling towers offers a wide choice of crossflow cooling tower models in the classic, proven crossflow design. Section 1 evaporative cooling towers an evaporative cooling tower is a heat exchanger that transfers heat from circulating water to the atmosphere. Tower have the ability to handle large water flow rate than forced draft cooling tower 2. Cross flow dryers one of the more popular continuous flow dryers is the cross flow dryer. Tradional hvac heating and cooling systems are used in schools, large office buildings, and hospital.
Cooling towers are also typed by the rela tive flow relationship of air and water within the tower, as follows. Understanding the different types of cooling towers. Such a fill, however, would not perfectly fit the requirements. Ect is the evaporative coil cooling tower which is an induced draft counter flow design closed circuit cooler.
The air, however, is introduced at the side either on one side singleflow tower or opposite sides doubleflow tower. One helpful means to that end is the water cooling tower. They are available in horizontal designs figure 1 and vertical or tower designs figure 2. We are continuously striving to offer better cooling solutions to customers, which are both, innovative and state of the art. Unlike natural draft cooling towers, mechanical draft cooling towers employ fans or other mechanics to circulate air through the tower. Cross flow dryers one of the more popular continuous flow dryers is the crossflow dryer. The evaporation is most efficient when the maximum water surface area is exposed to the maximum flow of air in the longest possible period of time. The results show that the cross flow cooling tower has high performance in the heat transfer process. Both crossflow and counterflow designs can be used in natural draft and in mechanical draft. Marley mx75 crossflow film fill spx cooling technologies. Which type of cooling tower is more efficient, cross flow. Cooling tower design calculations student cheresources. 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.
This design provides less resistance for the air flow, thereby reducing the fan horsepower required to meet the cooling demand. Mar, 2012 cooling tower design calculations posted in student. Other factors, which we will see, must be stated along with flow rate m3hr. Winter operation of an open cooling tower presents certain design considerations for a project.
Advantage of cross flow cooling tower linkedin slideshare. The range of cooling towers offered in the fws series is for single, double and multicell configurations. Fan energy requirements are determined for counterflow and crossflow towers designed for low initial cost and for energy efficiency. Exs series is an induced draft cross flow, film filled, frp multicell rectangular cooling tower designed for the equipment cooling, and industrial process cooling and air conditioning applications. Kripal lakhi singh chemical engineering iit madras a cooling tower in its most generic sense,is a heat rejection device, which extracts waste heat to the atmosphere through the cooling of a water stream to.
Like the counterflow splash fill tower, this is best suited for applications where water quality is not controlled. Double cross flow cooling tower cooling tower manufacturers. Cooling towers are designed and manufactured in many sizes and configurations. 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. Cross flow type usually used in square cooling tower, but the structure is fixed with large amount of iron piece, so it cost more higher than round cooling tower. Air flow enters one or more vertical faces of the cooling tower to meet the fill material. Larger fan size may result in greater efficiency and consequently lower power and sound level. Jun 22, 2018 cross flow is a design in which the air flow is directed perpendicular to the water flow air flow enters one or more vertical faces of the cooling tower to meet the fill material. Simulation of a crossflow cooling tower performance article pdf available in international journal of heat and mass transfer 50 may 2007 with 2,028 reads how we measure reads. Crossflow fans from pelonis technologies are constructed from a temperatureresistant aluminum alloy to withstand high heat environments. Generally, every cross fluted fill could be cut to be installed in a crossflow cooling tower. Cooling tower market by application, product, design and construction material. He also gives one numerical example of the calculation. A series of example scenarios are provided in the guidance files.
The crossflow splash fill cooling tower utilizes open pan hot water distribution and crosscurrent air water contact. The fan deck supports the motor and fan of the water spray system. Protec fws series cooling towers are factory or field assembled, cross flow cooling towers, designed to serve commercial, institutional and industrial loads. Under fan decks of counterflow towers an aver age water density of 0. The fan induces the ambient air into the tower to draft it upward.
Counterflow towers counterflow cooling towers have upward air flow that directly opposes the downward flow of the water providing very good thermal efficiency because the coolest air contacts the coolest water in the bottom section of the tower structure. A series of spray nozzles in each hot water basin distribute the water evenly over the fill. In a cross flow cooling tower, the hot water basin is used to distribute the warm return water flow uniformly over the tower fill see figure 6. Characterized by a long, rectangular shape, crossflow fans are ideal for areas where space is limited. The counterflow film fills feature a bonded edge with dedicated bond points for added strength and durability. Counter flow vs cross flow water cooling tower cooling. They are available in ac, dc and highefficiency ec types, as well as numerous sizes and efficiencies for. Inazumi22 proposes the mean enthalpy driving force in a cross flow cooling tower calculated by a graphical method.
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 air flows horizontally and the water falling downwards meets the air at dif ferent temperatures. Recently, water reuse has become popular and many cooling systems are being supplied reclaimed effluent or discharge water from other 2,, 1 and water reuse. If you read this book carefully, you can make any cooling tower design programs by yourself. Induced draft cooling tower is suitable for large cell sizes and fan sizes as compared with forced draft. Jun 07, 2019 cooling tower market by application, product, design and construction material. You may do so in any reasonable manner, but not in. This thesis evaluates the economics of alternative cooling tower capacity control methods.
Generally, every cross fluted fill could be cut to be installed in a cross flow cooling tower. Wacon white paper counterflow vs crossflow cooling towers 1 cross flow or counter flow cooling tower. In a counterflow cooling tower, water sprays are used to distribute the warm water see figure 8. Crossflow towers crossflow cooling towers are structured so that air flows horizontally across the falling water see figure 6. Pdf the new twodimensional mathematical model of the performance of a. Evaporation results from the difference in saturated pressure between the water films and the vapor pressure of moisture in the air passing through the fill. The factoryassembled marley av cooling tower is designed to minimize costs and maximize cooling tower performance through quick, easy installation and low maintenance operation. Cossfowr l induced draft cooling tower frceddafto r cooling tower in cross flow induced draft cooling towers, the water being cooled moves from the top down through the tower, while air moves across the water flow and then out the exhaust. Crossflow cooling towers offer excellent, easy accessibility of all key components such as fill, drift eliminators, mechanical equipment and water distribution system. Cooling water systems an overview of cooling towers 2012 instructor. Exs series is an induced draft crossflow, film filled, frp multicell rectangular cooling tower designed for the equipment cooling, and industrial process cooling and air conditioning applications.
Important properties of water a primary consideration for the operation of the. Its single flow, induced draft crossflow design offers energy savings in a small footprint installation, making it an excellent crossflow cooling tower replacement for. Cooling water systems an overview of cooling towers. As this occurs, a small volume of water is evaporated, reducing the temperature of the water being circulated through the tower.
Pdf simulation of a crossflow cooling tower performance. In crossflow cooling tower water enters perpendicularly while air enters for the side walls of the tower horizontally and then rise upward from the center of the cooling tower. Performance curves for mechanical draft cooling towers, jownal of engineering for power, oct. This design virtually eliminates ineffective space in the cooling layers, thus providing excellent cooling efficiency and space economy. All areas within the general category from biological effects to heat transfer developments have. Marley mx75 is a hanging film type cooling tower fill which spreads the water into a thin film, flowing over large vertical surfaces, promoting maximum exposure to. In cross flow cooling tower type, the air flow is in perpendicular direction to the water flow. Counter flow vs cross flow counter flow cooling tower. Simulation of a counterflow and crossflow cooling tower. Cross flow cooling tower cooling towers heat exchanger. In crossflow cooling towers air enters at 90 degree to the direction of water. However, although this ice may still be considered acceptable, it has.
Rectangular, crossflow cooling water flow low noise outside tubing cti certified. Figure 5 induced draft, crossflow, propeller fan tower. In this type of dryer, airflow is perpendicular to grain flow. Outline of models opened type, cross flow, and induced draft models. This file is licensed under the creative commons attributionshare alike 3. The cooling tower is manufactured using frp with a stainless steel supporting structure. This comparison evaluated at distinct operating conditions such as variations of weather, different water to air flow ratio. This heat rejection is accomplished through the natural process of evaporation that takes place when air and water is brought into direct contact in the cooling tower. It is in the design stage of a project that these decisions must be made to minimize ice formation on the future cooling tower. In the counter flow induced draft design, hot water enters at the top, while the air is intro duced at the bottom and.
983 1214 1369 1229 1140 1154 1062 819 666 1367 522 278 865 786 1159 930 1004 1004 145 17 957 1083 835 1269 462 1410 1051 1437 1432 1374 942