Simulation of a counterflow and crossflow cooling tower. 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. The efficiency of cooling towers relies on the accurate and reliable information on the outdoor wet bulb temperature, required to avoid cooling tower increased water and energy usage and reduced lifetime of. An effective cooling tower water treatment system will provide the right quality of water to your cooling tower, the correct circulation chemistry, allowing it to run efficiently, avoiding problematic deposition, and maintaining a manageable amount of blowdown. Scale, in addition to causing physical blockage of piping, equipment, and the cooling tower, also reduces heat transfer and increases the energy use. The cooling water supply may be from a chiller, city tap water, or a cooling tower. The water balancing of the process condenser water and cooling tower, along with the.
Cooling tower issues and troubleshooting approaches the water temperature rises unexpectedly. This manual is not intended to be allencompassing and thoroughly definitive. Marley nc class cooling tower user manual spx cooling. Conductivity trend for manual or timed blowdown control. Development of any of these problems greatly reduces the cooling efficiency and in severe cases can collapse portions of the tower fill or tower structure. The cooling tower had two possible makeup water sources.
Identify cooling tower systesm 153 inspect screenswater level on tower 154 test spray nozzles on a water tower 155 test water pump on tower 156 identify primarysecotdary controls in commercial system, 157 unit 25. Cooling tower trouble shooting, delta cooling towers india. This booklet describes the most common types of heat pumps, and discusses the factors involved in choosing, installing, operating, and maintaining a heat pump. In open circuit systems the recirculating water returns to the tower after 1 one ton of refrigeration is equal to 12,000 btuhour.
Cooling tower pumping and piping bottom vented downcomer. Or it might include the use of industrial air washers in which air is filtered, sprayed and then. Cooling tower control problem by james mcdonald, pe, cwt originally published. The marley nc class cooling tower purchased for this installation repre sents the. The water exits the cooling tower and is sent back to the exchangers or to other units for further cooling. Locate the probe assembly where an active sample of cooling tower water is available. Other factors, which we will see, must be stated along with flow rate m3hr. 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.
Failure to follow the guidelines provided in this manual may result in poor performance, unnecessary equipment failure and down time. Cooling tower selection, sizing and troubleshooting, kolmetz handbook of process equipment design. Cooling tower efficiency is limited by the ambient wet bulb temperature. The ability to accurately monitor and control cooling tower water from afar gives water treatment service managers a leg up on troubleshooting. Parameters affecting engine transfer engine heat transfer depends upon many parameters,unless the effect of these parameters is known, the design of a proper cooling system will be difficult. 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. All options cooling towers closed circuit cooling towers hybrid evaporative condensers ice thermal storage remote sump tanks equipment controls parts and services. Cooling tower performance in free cooling applications is dependent upon both the system and cooling tower design. Minerals can form deposits or scale on the tower materials. If you need some help with your cooling tower service and maintenance in the phoenix area, cooling tower products has you covered. As with biological growth, sedimentation and scaling of tower surfaces reduce the overall heat transfer coefficient and the cooling capability of the tower, as. 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. Department of energy assistant secretary for resource. Cooling towers correctly at high cycles of concentration cooling towers o john e.
May 09, 2015 performing maintenance on cooling towers in san diego. Read online ahu system manuals in files basics of hvac this hvac training video will identify the purpose and goals of the hvac system, describe basic hvac parts, and explain how. We use law, science, and economics to craft innovative solutions to the most pressing conservation issues in the region. Cstn september 2002 a client had a large, threecell cooling tower system that was having problems maintaining conductivity. Simulation of a counterflow and crossflow cooling tower by. Department of energy building energy codes program. Cooling towers must be cleaned on a regular basis to prevent the growth.
Cooling tower troubleshooting universal tower parts. They are supplied with permanently lubricated bearings and special moisture protection on the bearings, shaft and windings. All cooling towers operate on the principle of removing heat from water by evaporating a small portion of the water that is recirculated through the unit. As with biological growth, sedimentation and scaling of tower surfaces reduce the overall heat transfer coefficient and the cooling capability of the tower, as illustrated in figure 2. In ideal case the cold water temperature will be equal to the wet bulb temperature. Heres how to avoid potential scaling and corrosion problems and control costs. For example, excessive water flow, excessive airflow, and water bypassing the tower drift. A specialized cooling system might utilize compression or absorptiontype refrigeration or air conditioning systems, which can be used to cool both processes and work spaces. The water exits the cooling tower and is sent back to the exchangers or to other. Large volumes of air flowing through the heat transfer media help increase the rate of evaporation and cooling capacity of the tower. It accomplishes this by providing intimate mixing of water and air, which results in cooling primarily by evaporating approximately 1 % of the flow for each 10.
Here are a few potential problems and possible solutions to consider. Hvac water chillers and cooling towers fundamentals. Increasing central plant efficiency via a water to water. Once you have an issue, it requires at least several hours. See maintenance manual for startup instructions and lubrication recommendations. Introduction to commercial building hvac systems and energy code requirements reid hart, pe, pacific northwest national laboratory u. Introduction to commercial building hvac systems and energy. A cooling tower is merely a heat changer or rather a heat rejection device. A counterflow cooling tower is widely used in air conditioning systems and industrial process. Cooling tower types cooling towers fall into two main categories. This, in turn, helps conserve the amount of any makeup water or chemicals needed. Operating and maintenance instructions cooling towers.
The locations water source, age of the cooling tower, and even the air being used to cool the water varies by location. Lockout of fan motor and circulating pumps during inspection and maintenance. They must be situated so that the assembly is always full of water when the tower is operating. Cooling towers maintenance and troubleshooting part 1 youtube. As an iso 9001 certified manufacturer, thermal care provides heat transfer equipment for over 50 industries and specializes in meeting the specific needs of our customers by offering both standard and custom designed. Thermal care is a leading manufacturer of water chillers, process cooling equipment and systems for applications worldwide. Methods of efficiency improvement of the cooling tower operation will be explained and discussed. Some of the challenges faced by the team and calculations required included. This airflow is generated by fans powered by electric motors. Back to top crossflow cooling towers flow diagram in crossflow cooling tower systems the water vertically flows through the fill media while the air horizontally flows across the falling water. As this occurs, a small volume of water is evaporated, reducing the temperature of the water being circulated through the tower. This means cooling tower maintenance and water treatment is a progressive and customized undertaking. Some towers are furnished with a distribution manifold with nozzles which require additional pressure.
Finally, outside air is drawn across the cooling tower, removing the heat from the water through the process of evaporation. Again, this will be a first issue releasing the actual engineering approach. Hvac damper actuator for economizer free cooling this damper actuator controls a free cooling damper for an economizer. Introduction to commercial building hvac systems and. Hvacr service and troubleshooting with the professor larities of symptoms in both scenarios of an overcharge of refrigerant and restricted airflow over the condenser. Cooling tower fill is typically arranged in packs of thin cormgated plastic sheets or, alternately, as splash bars supported in a grid pattern. Cooling towers maintenance and troubleshooting part 1. When experiencing any operational issues, use the following troubleshooting methods to resolve the problem. This fact sheet deals with the common cooling tower malfunctioning with probable cause and procedures for checking and correcting possible faults. Each one pound of water that is evaporated removes approximately 1,000 btus in the form of latent heat. Two general types of air conditioning cooling refrigerantbased. Despite the fact that the basic cooling tower operating concept is easy to grasp, simply air interacting with water, like any other form of machinery proper maintenance is required for optimal performance. How a chiller, cooling tower and air handling unit work together duration. Splash fills disintegrates the hot water from vertical direction and it splits the water to pass through next level of splash bars.
View and download coolingtech s04600x user manual online. The heat that is removed is called the latent heat of vaporization. This manual contains vital information for the proper installation and operation of. The purpose of the cti manual is to bring together into a common place, comprehensive information pertaining to cooling towers and other types of equipment that reject heat to the atmosphere.
Cooling tower fill is the main heat transfer area available for heat transfer from hot. Engineering report and the project design documents. After 24 hours after 24 hours of operation under load, the following services should be performed. Understanding key components of cooling towers and. The installation of a heat pump was considered and implemented as part of the original plant design at the novartis flu vaccine facility in holly springs, north carolina. Troubleshooting guide diagnosing cooling service part related problems now we are ready to go into more detail. Figure 816 shows the operation of the mechanicaldraft cooling tower. Common cooling tower troubleshooting issues ntt training. Technical information for cooling towers using recycled water. For example, a cooling tower sized to cool 4540 m 3hr through a. 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.
It is no surprise that the applications from the technology of cooling towers has been benefiting industries, power plants, the processing plants of natural gas, refineries, and also, the commercial hvac systems, all the way to the early 19 th century. Drift eliminators are installed to prevent water entrained in the air from leaving the system. The pulsepure integrated controller is microprocessordriven with onoff. Cooling water problems and solutions ced engineering. If it is not available it may be assumed as for natural draft cooling tower d 0.
The cooling tower casing and the water basin are made of strong corrosionproof fibreglass reinforced polyester resin. I prepared the documents so that the engineers can easily understand the cooling tower theory and can make the design program by themselves through the. For nearly a century, we have provided exceptional quality equipment and service to the hvac, process cooling, industrial, and refrigeration markets. Classified by the aircirculation method used, there are two types of cooling towers. This, in turn, helps conserve the amount of any makeup water or chemicals needed and results in a highersolid waste. The incoming cooling water pressure should be limited to 125 psi 861. This euromatech cooling towers training course will cover many important aspects of cooling tower process control, correct operation and water management. Typical closed loop cooling tower system is shown in figure 7. Cooling system operation below is an explanation of this systems operation radiator the radiator is a device designed to dissipate the heat which the coolant has absorbed from the engine. The facility files cooling tower addition at pharmaceutical building designbidbuild project the training process should include specific hvac system and equipment training but also emergency plan training due to the hvac event. Cooling water systems an overview of cooling towers 2012 instructor. By keeping a cooling tower in good working order, savings in time and energy can be made. An efficient industrial process or hvac operation depends upon trouble free functioning of a cooling tower. Common cooling tower water treatment problems and how to.
They are either naturaldraft or mechanicaldraft towers. Always start by determining the correct part application. These motors are built to cooling tower duty speci. If you read this book carefully, you can make any cooling tower design programs by yourself. Cooling tower efficiency calculations cooling tower approach. Oct, 2016 an effective cooling tower water treatment system will provide the right quality of water to your cooling tower, the correct circulation chemistry, allowing it to run efficiently, avoiding problematic deposition, and maintaining a manageable amount of blowdown. Inquiry documents should define the owners plan for payment of. In a counterflow tower, the air is induced from the bottom of the tower and is in contact with the falling water over the entire height of the tower. System containing air anotherimilar s scenario would be a refrigeration system containing air, as in table 3.
Tower water must also be evaluated for solids and mineral content. With the best technicians, quality parts, and the highest standards customer satisfaction we will help you find and solve all of your cooling tower problems. Toilet wont flush water stays in bowl easy fix solution siphon jets cleanout. Figure 815 shows the operation of the naturaldraft cooling tower. For example, the thermal conductivity btu hr ft2 fin of copper is 2674, while the common cooling water scale calcium carbonate has a thermal conductivity of 6.
Instead of responding to major problems, im able to cut them off before they develop, said tomsheck. The cooling tower circuit differs slightly from the basic open circuit in that the discharge piping is connected directly to a distribution basin. Even so, problems can develop and troubleshooting and repair will be required. Cooling tower location must prevent cooling tower discharge air from entering the fresh air intake ducts of any building. Cooling tower fill is the main heat transfer area available for heat transfer from hot water to cold air. Here are some simple troubleshooting tips to what might be causing you problems.
The cooling towers at biogen idec are the largest users of water in the facility. This section provides an introduction of cooling tower designs. Hvac checklist long form needs attention not component ok applicable comments page 14 of 14 pm preventive maintenance schedule available. Analysis a the mass flow rate of dry air through the tower remains constant mm m aa a12, but the mass flow rate of liquid water decreases by an amount equal to the amount of water that vaporizes in the tower during the cooling process. Waste oil and refrigerant properly stored and disposed of. For evapco induced draft and forced draft cooling towers.
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 water systems an overview of cooling towers. By converting to recycled water, cooling tower customers can secure a. Range range is determined not by the cooling tower, but by the process it is serving. Tower maintenance and operation levels also can influence the formation of drift droplets. One helpful means to that end is the water cooling tower. Publishing terms and conditions i agree to the terms and conditions for article and media. The figure below provides a conceptual view of chilled water airconditioning system with watercooled condenser. It is constructed to hold a large amount of water in tubes or passages which provide a large area in contact with the atmosphere. Evaporative cooling tower in a compact, noncorrosive.
The cooling water supply should be connected to the facility water inlet on the liquidto. The probe and flow switch system dependent must be located where they can easily be removed for cleaning and inspection. Protection of workers from exposure to biological and chemical hazards within the cooling water system. It might utilize a cooling coil below the deck of the cooling tower. In addition to these specific documents, spx publishes numerous tech. The water basin is an integrated part of the cooling tower casing, on this reason leakage is prevented for the examination of the spray nozzles and for maintenance on the adjustable float valve inspection hatches are provided. Cooling tower evaporative cooling system measurement. The manual has been developed in the form of individual chapters, each of which stands on its own merit, and includes a list of references and a bibliography. Inadequate flow rates downcomer flow rates can be so low, relative to pipe size, as to allow air to enter at the pipe discharge.
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