Best management practice and guidance manual for cooling towers. Installation, operation, and maintenance instruction for water cooled chiller. For the tower piping circuit, the pump must overcome the piping flow friction loss. Principle of operation a cooling tower cools water by a combination of heat and mass. 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 cooling tower is often the forgotten component of a water cooling system when it comes to maintenance. 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.
If you read this book carefully, you can make any cooling tower design programs by yourself. Design and operation considerations cooling towers are a very important part of many chemical plants. This system sends cooling water out of the equipment and into a pond or cooling tower, which is open to the atmosphere. The impurities are from the accumulation of dirt and salts which build. In operation cooling towers are efficient air cleaners. Cooling tower bureau of energy efficiency 5 syllabus cooling tower. Failure to follow the guidelines provided in this manual may result in poor performance, unnecessary equipment failure and down time. See the more detailed explanation of cooling towers systems.
Providing proper installation, maintenance and operation of the series tci cooling tower is the owners responsibility, and is required for safe and efficient operation. Water is the favored heattransfer medium for many chemical process industries cpi applications because of its availability, its high heat capacity, and its relatively low cost. It must also provide the energy head necessary to raise water from a low to a higher static head level. The goal of this edition is to provide the hvac designer, engineers the building owner and his operating and maintenance staff, the architect, and the mechanical contractor with definitive and practical information and guidance relative to the application. The tower takes the heat from the water stream and rejects it to. During operation, the fan forces air at a low velocity horizontally.
Dec 19, 2017 cooling towers are recirculating water systems used to remove heat from building air conditioning equipment and industrial processes. Cooling tower systems guidance for energy efficient operation introduction in 2000 the introduction of the pilot scheme for water cooled air conditioning in hong kong offered opportunities for building owners to lower their air conditioning operating costs through the application of cooling tower systems for commercial air conditioning systems. Some icing on cooling towers during subfreezing weather is normal and typically not a concern for the operation of the cooling tower. As on any outside structure, ice can form on a cooling tower in the wintertime purely by natural effect. Types of ice as on any outside structure, ice can form on a cooling tower in the wintertime purely by natural effect. Sensible heat that changes temperature is also responsible for part of the cooling tower s operation. See the more detailed explanation of cooling towers systems, diagrams, pictures and principles below table of contents what is a cooling tower how do cooling towers work. Here we explain in full detail how does a cooling tower work, cooling tower working principles with example text, pictures and diagrams. Range hot water temperature cold water temperature cooling tower efficiency calculation. Note indicates presence of a hazard which can cause severe personal injury, death or substantial property damage if ignored. Dry cool air enters the bottom of tower, moves thru fill where it accepts heat energy from the hot water and. As this occurs, a small volume of water is evaporated, reducing the temperature of the water being circulated through the tower.
Operated by the alliance for sustainable energy, llc. Cpi plants often use evaporative watercooled cooling towers to remove. Cooling tower efficiency is limited by the ambient wet bulb temperature. Before we look at how a cooling tower rejects heat. Water treatment chemicals utilized for cooling tower systems which contain molybdenum are prohibited in the jea sanitary sewer. Good operation and maintenance practice of fresh water cooling towers.
Water savings of cooling tower efficiency measures for use in performance contracts. Cooling rates of mechanical draft towers depend upon their fan diameter and speed of operation. The maintenance program and plan mpp is a detailed plan customized for a cooling tower system that describes operational and administrative strategies and process control measures to be taken to prevent and control the growth of legionella. Here evaporation occurs, removing heat along with the evaporated water. Chapter 8 cooling towers system shutdown and startup. Cooling tower evaporative cooling system measurement. They require specialized maintenance to ensure safe, efficient, and reliable operation, including an effective water treatment program. We are dedicated to designing and manufacturing the highest quality products for the evaporative cooling and industrial refrigeration markets around the globe. A primary consideration for the operation of the cooling tower system is the water quality of the makeup source. In this type of cooling tower the water to be cooled is distributed evenly over a packing, which is ventilated from below with air.
Installation, operation, and maintenance instruction for. Lets first look at the parts inside a cooling tower. Pdf a large number of producers offer a wide choice of various types of industrial cooling towers. They represent a relatively inexpensive and dependable means of removing low grade heat from cooling water. Those responsible for the specifications, purchasing and operation of plant, station, or building cooling. When water is warmer that the air, there is a tendency for the air to cool the water. 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 near. The fan outlet section can be connected with a flexible channel to the cooling tower casing, this is recommended for low noise or low vibration execution of the cooling tower since the flexible connection prevents propagation of structure borne noise via cooling tower casing. It is possible to check the current malfunction and the previous. All cooling tower discharges must be in accordance with applicable state, local or federal rules and regulations. 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.
The technical data has been taken from a mechanical draft cooling tower. This water is often discharged to the sanitary sewer system. 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. Cooling towers and condenser water systems design and. Cooling towers are used to reject heat through the natural process of evaporation. To move a specified quantity of air through the system, overcoming the system resistance, which is defined as the pressure loss. Design and operation 2005 2018 trane a business of ingersoll rand.
The air then gets hotter as it gains the sensible heat of the water and the water is cooled as its. The calculation of cooling tower efficiency involves the range and approach of the cooling tower. In either case, whether caused by nature or by the. A psychromehic analysis of the air passing through. 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.
Oct 02, 2016 the system has been designed so that the condenser water leaving the cooling tower and reentering the chiller condenser, must be around 27c 80. Operation of the cooling tower as heat rejection device is based on a principle where waste thermal energy is extracted from hot water to the. Carefully read the manual before installation or operation of the tower and follow all instructions. Displayed parameters include inlet and outlet temperature of cooling water, inlet and outlet temperature of cool water, evaporating and condensing pressure ect. Cooling tower basics calculation formulas cooling tower. Operating and maintenance instructions cooling towers. By understanding how cooling tower systems function, facility owners and operators can operate and maintain their systems more. Warm recirculating water is sent to the cooling tower where a portion of the water is evaporated into the air passing. Water will be drained from the cooling tower for maintenance purposes but also periodically during normal operation when the level of impurities in the water gets too high. Tower operation in freezing weather is always a difficult challenge, and in some applications there is a yearround demand for cooling, even at reduced loads, so the tower must remain operational through the winter even under freezing conditions.
In that regard, cooling towers and evaporative condensers are presented as efficient devices that operate with lowlevel water temperature. Cooling tower fill media what is cooling tower fill media. The colder the weather, the more that certain relatively simple protocols must be followed and pre. Closed loop cooling tower system the makeup water source is used to replenish water lost to evaporation. Ice will form first at any of the airwater interfaces in the cool.
Cooling tower fans are used on induced draft cooling towers to pull air up through the fill media. 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. Open the bleed line valve must be furnished by others on cooling tower models vxtn215 through vxt4800 and adjust bleed to the recommended rate see water treatment. One helpful means to that end is the water cooling tower. The dirt and debris is entrained into the condenser water. However, since its heat transfer operation creates. Unchecked it accumulates in the cooling tower fill causing blockages, in the tower basin, and fouling heat exchanger surfaces and tubing. Best practice guidelines water conservation in cooling towers au 1.
The appendix to this bulletin includes a quickreference summary of. A newly installed cooling tower reliably delivers the design fluid temperature and flow rate. Cooling towers are recirculating water systems used to remove heat from building air conditioning equipment and industrial processes. Hvac water chillers and cooling towers fundamentals application and operation 2nd edition 2011 by herbert w. Cooling towers overcome most of these problems and therefore are commonly used to dissipate heat from watercooled refrigera tion, airconditioning, and industrial process systems. Cooling towers make use of evaporation whereby some of the water is evaporatednto a moving air i stream and subsequently discharged into the atmosphere. 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 tower efficiency calculations cooling tower approach.
Types and performance evaluation, efficient system operation, flow control strategies and energy saving opportunities, assessment of cooling towers 7. After 24 hours after 24 hours of operation under load, the following services should be performed. In addition, operating without enough heat load in freezing conditions is an obvious problem for either design. Best management practice and guidance manual for cooling. All cooling towers operate on the principle of removing heat from water be evaporating a small portion of water that is recirculated through the unit. In this article explained about basic concepts of cooling tower, types of cooling towers, formula for cooling tower efficiency. Cooling towers are a very important part of many chemical plants. Here we will discuss ways to deal with freezing on different types of towers. Fill media is by far one of the most important cooling tower. A cooling tower is heat removal device that uses water to transfer process waste heat into the atmosphere. Again, this will be a first issue releasing the actual engineering approach. The manufacturer of your cooling tower usually lets customers order new gearboxes or have trained technicians that can repair or rebuild a faulty gearbox using original equipment manufactured parts. Cooling tower operation forced draught cooling towers use the evaporation of a liquid often water into air to achieve cooling.
Since, the mechanical draft cooling towers are much more widely. As a result, the remainder of the water is cooled down significantly. What problems are associated with operating a cooling tower system. Winter operation considerations for open cooling towers. Cooling towers are common place in building hvac systems, cold storage, industry, etc. Optimum design and operation of an hvac cooling tower. Cooling tower outlet temperature is called cooling tower range. Operation considerations of cooling tower cooling tower mass balance cooling tower mass balance gives an indication about makeup water requirement in system. Guide for energy efficient cooling tower design and operation.
View and download marley aquatower 490a user manual online. Its a good example of the phrase out of sight, out of mind. Cooling towers and condenser water systems design and operation. It is then combined with makeup water, which replaces the evaporated water, and is sent through the system again. 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.
Dry cooling towers operate by heat transmission through a surface that divides the working fluid from ambient air. The makeup water source is used to replenish water lost to evaporation. The basics of cooling tower water treatment 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. Chapter 8 cooling towers system shutdown and start. This design virtually eliminates ineffective space in the cooling layers, thus providing ex.
Installation guidelines in order to ensure that you receive the best possible performance from your rsd cooling tower, it is important that you follow some basic guidelines. Here we explain in full detail how cooling towers operate with example text, pictures. In addition, being both a water cooling and an air moving device, a cooling tower can promote the formation of ice by its very operation. Cooling towers have been operated successfully in some of the most severe freezing conditions around the. Carry out frequent visual inspections and routine maintenance services during operation in subfreezing weather. The appendix to this bulletin includes a quickreference summary of the. Operation of a cooling tower choose and design a system that meets your process requirements. Dimension of natural cooling tower 17 cooling tower operation in freezing weather cooling towers with malfunctions can freeze during very cold weather. Operation and maintenance of cooling towers must be in accordance with. The tower often consists of a sprinkler system which wets a highsurfacearea substrate plates continuously, while air flow through the chamber converts liquid to vapor. Typically, freezing starts at the corners of a cooling tower with a reduced or absent heat load. Operation of cooling tower counterflow design 5 counterflow design. Pdf industrial cooling tower design and operation in the moderate. By understanding how cooling tower systems function, facility owners and operators can operate and maintain their systems.
A guideline on good operation and maintenance practice of fresh water cooling towers pdf format 2. Operation and maintenance instructions for evapco induced draft and forced draft cooling towers for evapco authorized parts and service, contact your local mr. For systems with multiple cooling towers, conditional operation, such as. Winter operation of an open cooling tower presents certain design considerations for a project. Suptic air conditioning and refrigeration systems ranging from light commercial to industrial applications may rely on cooling towers to remove waste. Hvac water chillers and cooling towers fundamentals. Requirements of joining fwct scheme the requirements of application and operation of the fwct scheme are detailed in the following documents. The owners of cooling tower installations should maintain proper conditions of the fresh water cooling towers to minimize contamination and nuisances to the public. 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. Increased freezing conditions can create growing volumes of ice, resulting in increased.
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