For maximum water efficiency, cooling towers should be operated at six or more cycles of concentration. Cooling tower info pdf, delta cooling towers india your. Cooling tower bureau of energy efficiency 9 figure 7. Cooling towers vary in size and design based on the cooling load of a building. Cooling tower efficiency is limited by the ambient wet bulb temperature. A guide to troublefree cooling towers a basic understanding of cooling tower operation and maintenance will help keep a cooling water system running in top condition, year after year by david m. They can achieve water temperatures below the dry bulb temperature tdb of the air cooling air but not the wet bulb temperature. 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. 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. Cooling tower heat exchanger systems beat closedcircuit. For example, the cooling tower might be specified to cool 4540 m3hr from 48. Cooling towers energy efficiency guide for industry in asia. First european thermal performance efficiency standard for. In this article explained about basic concepts of cooling tower, types of cooling towers, formula for cooling tower efficiency.
The overall efficiency of a cooling tower is directly related to the design of the towers water distribution and heat exchange surface. Monroe graduated from the university of houston in 19. If you read this book carefully, you can make any cooling tower design programs by yourself. Cooling tower systems operation is most efficient when their heat transfer surfaces are clean. Monroe manager, research and development hudson products corporation houston, texas abstract robert c. Registration due dates new cooling towers must be registered before operation.
A systematic control approach to improve energy efficiency. This thesis evaluates the economics of alternative cooling tower capacity control methods. Fan energy requirements are determined for counterflow and crossflow towers designed for low initial cost and for energy efficiency. Cooling towers are usually specified to cool a certain flow rate from one temperature to another temperature at a certain wet bulb temperature. Cooling tower plays a major role in chemical process industry. Cooling tower efficiency calculation is described in this article. They reject process heat from the cooling water to atmosphere and keep the water cool. Cooling tower basics calculation formulas cooling tower. Chiller vs cooling tower we often get the question as to when to use a chiller andor cooling tower for process cooling. Loose connections, failing bearings, cavitation, clogged strainers, excessive vibration, and nondesign operating conditions result in reduced water flow, reduced efficiency, and premature equipment failure. Closedcircuit towers one of the primary differentiations between cooling towers is whether it is an open or closedcircuit tower.
High efficiency chillers can produce chilled water using less than 0. Cooling tower efficiency calculations cooling tower efficiency calculation is described in this article. 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 cooling load is determined by the size of a building from which heat needs to be extracted. No nonsense water treatment cooling tower efficiency and approach.
The wetbulb temperature is a type of temperature measurement that reflects the physical properties of a system with a mixture of a gas and a vapor, usually air and water vapor. Prescriptive efficiency requirements for cooling towers. 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 efficiency hot water temperature cold water temperature x 100 hot water temperature wet bulb temperature or simply. Improving cooling tower fan system efficiencies by robert c. It not only says little about the efficiency of the chilled water system, but the effect of tower approach on chilled water system efficiency also is limited.
Suptic air conditioning and refrigeration systems ranging from light commercial to industrial applications may rely on cooling towers to remove waste. Efficient, sustainable cooling minimized emissions easy maintenance and increased availability increased feed rate lower inlet and outlet temperature highly efficient cooling with outotec cooling towers outotec cooling towers provide high efficiency directsolution cooling for applications such as spent electrolyte cooling. The technical data has been taken from a mechanical draft cooling tower. Newly installed opencircuit cooling towers serving condenser water loops which total 900 gpm or greater, shall have a rated efficiency of no less than 80 gpmhp when rated in accordance to the test procedures and rating conditions as listed in table 110. Cooling towers use the evaporation to cool the circulated water. Drift eliminators are installed to prevent water entrained in the air from leaving the system. An opencircuit cooling tower, commonly called a cooling tower, is a specialized heat exchanger in which two fluids air and water are. Local amendments to the 2015 uniform mechanical code. A cooling tower use evaporative cooling to reduce the temperature of circulated water, and. Monroe the questions most frequently asked of a fan engineer about axial flow fans for todays wet cooling towers generally cover. The cooling component of this new electricity station is a natural draft cooling tower 200 m high, the tallest cooling tower and the largest shell structure in the world. However, due to variations in the water source and their operating in an open environment, cooling towers are subject to four major water treatment concerns. These studies were complicated by the fact that the cooling tower market is typically driven by one of two powerful, yet often conflicting requirements.
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. Galvanized steel hdpe cooling tower stainless steel exchanger 42 17. Cooling towers overcome most of these problems and therefore are commonly used to dissipate heat from watercooled refrigera tion, airconditioning, and industrial process systems. Proper water flow is important to achieve optimum heat transfer. Cooling tower heat exchanger systems beat closedcircuit cooling towers for economy and efficiency. All published sound data for marley nc cooling towers has been independently verified by a ctilicensed test agency so you can trust that your cooling tower will meet sound levels as specified. Since the cooling towers are based on the principles of evaporative cooling, the maximum cooling tower efficiency depends on the wet bulb temperature of the air. Cooling tower efficiency calculations cooling tower approach. 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 priceperformance ratio how much it costs to operate the equipment weighed against with its ability to do its job, or simply called efficiency. Annual fan electrical energy requirements are calculated for towers with singlespeed, twospeed, and variablespeed fans. The design of the distribution system affects the pump head to bring the hot water to the tower inlet.
If your requirements are for 90 deg f 32 c then you most likely need a cooling tower or fluid. As this occurs, a small volume of water is evaporated, reducing the temperature of the water being circulated through the tower. Water efficiency management guide mechanical systems. Metering water put into and discharged from the cooling tower ensures the cooling tower is operating properly and can help identify leaks or other malfunctions. 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. Cooling tower evaporative cooling system measurement and. Cooling tower evaporative cooling system measurement. How to optimize the energy efficiency of cooling towers. The tower takes the heat from the water stream and rejects it to the air stream and cooling is partly achieved through the evaporation of a portion of the water. An indirect cooling tower uses a cooling tower pump. Cooling tower systems include all components that provide comfort cooling by rejecting heat to the atmosphere through the evaporative process. What drives 1 note that effectiveness refers to the thermal efficiency of the cooling tower fill and the.
The calculation of cooling tower efficiency involves the range and approach of the cooling tower. In the ideal case, the cold water temperature will be equal to the wetbulb temperature. The easy answer is what temperature waterglycol do you need. Abstract this paper presents detailed methodology of a induced draft cooling tower of counter flow type in which its efficiency, effectiveness, characteristics are calculated. The water consumption rate of a cooling tower system is only about 5% of that of a oncethrough system, making it the least expensive system to. The cooling tower must be adequately sized to reject this same amount of heat to the atmosphere. Cooling towers are used to reject heat through the natural process of evaporation. Cooling tower efficiency cooling tower efficiency can be expressed as efficiency 100t1t2t1t3 where t1 inlet temperature of water to the tower t2 outlet temperature of water from the tower t3 wet bulb temperature of air. Hvac use of a cooling tower pairs the cooling tower with a watercooled chiller or watercooled condenser. Warm recirculating water is sent to the cooling tower where a portion of the water is evaporated into the air passing. Cooling tower outlet temperature was predicted by mathematical model created created model was optimized dynamically improved efficiency and optimized number of stages were obtained three stages with 60 % efficiency cooling tower can be operated by decreasing the water flowrate up to 30 % without affecting the overall. Maximum cooling tower efficiency is limited by the wetbulb temperature of the cooling air.