A cooling tower rejects waste heat to the atmosphere through with a cooling water stream to a lower temperature. Cooling tower evaporative cooling system measurement. They are located in areas that are situated after the fill and water sprays and just before the area where the air exits the cooling tower see figures 6 and 8. 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. As the water flows through the cooling tower, it is exposed to air, which is being pulled. This water is often discharged to the sanitary sewer system. Water outputs from a cooling tower include controlled losses such as evaporation, bleed, drift and pump gland leakage and uncontrolled losses including leaks, splash out, overflows and windage. Air intake louver is a part of the cooling tower that serves as a block for water splashout, noise, and debris. The performance of a cooling tower is dependent upon a number of factors, such as conditions of the atmosphere, conditions of the cooling water flow, conditions of equipment and conditions of the site, and the object of this part of bs 4485 is to describe methods for the accurate determination of thermal performance. The water sprays through nozzles onto banks of material called fill, which slows the flow of water through the cooling tower, and exposes as much water surface area as possible for maximum air water contact. In technical terms, cooling towers are engineered and designed based on. Course contents evaporative coolers, often called swamp coolers, are cooling systems that use only water and a blower to circulate air.
This is a closedloop system, in which the cooling water is sent from the condenser to the cooling tower, where the heat of the water transfers to the ambient air primarily by evaporation. A basic understanding of the system water distribution shall be established in order to properly operate and maintain a cooling tower on a water efficient manner. Cooling water systems remove heat generated from a variety of industrial processes. In technical terms, cooling towers are engineered and designed based on a specified cooling load, expressed in refrigeration tons. Here the extent of cooling obtained is much closer to that of a wet cooling tower. An introduction to water cooling towers cedengineering. A simple model to help understand water use at power plants. Water first passes through a heat exchanger where it absorbs heat. 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.
Air cooling system in this type of cooling system, the heat, which is conducted to the outer parts of the engine. When warm, dry unsaturated air is pulled through a watersoaked pad, water is evaporated and is absorbed as water vapor into the air. Maintain cooling tower fill to prevent water from dripping or sloshing from the fill and onto the ground. In simple terms, we can define it as an ecofriendly device that can reduce the temperature of the warmest water in the most efficient way at any source. The water exits the cooling tower and is sent back to the exchangers or to other units for further cooling. The purpose is to define a preventive maintenance program and plan for cooling towers at the suny polytechnic quad c building utica new york. Motor is to be provided with protection systems like earth fault relay and over load relay etc. How chiller, ahu, rtu work working principle air handling unit, rooftop unit. Cooling tower systems work by using water to extract waste heat from a system and ejecting it into the atmosphere primarily through evaporation. When warm, dry unsaturated air is pulled through a water soaked pad, water is evaporated and is absorbed as water vapor into the air. There are a few kinds of cooling towers, but most work using evaporation and are very energy efficient. A simple model to help understand water use at power plants anna delgado and howard j.
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. The water balance of a tower or cooling water system involves all of the water inputs and outputs associated with the operation of the system. In addition to blow down, most recirculating cooling water system maintenance plans include. During the cooling tower working process, small volumes of water evaporate, lowering the temperature of the water thats being circulated throughout the cooling tower. This should be expressed in fahrenheit and is denoted as dt in the formula. In this type of cooling tower, fan is used to circulate the air. Cooling tower plays a major role in chemical process industry. The chiller adds heat to the condenser water and the cooling tower cools it down by rejecting this into the atmosphere. Types of cooling system there are two types of cooling systems. Cooling tower evaporative cooling system measurement and verification protocol guidelines for energy service companies and water efficiency service companies to determine water savings of cooling tower efficiency measures for use in performance contracts. A cooling tower functions as a heat exchanger where water and air are placed in contact with each other to reduce the temperature of the water. Drift eliminators are also known as mist eliminators. Mechanical draft towers utilize large fans to force or suck air through circulated water. 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.
Warm recirculating water is sent to the cooling tower where a portion of the water is evaporated into the air passing through the tower. An opencircuit cooling tower, commonly called a cooling tower, is a specialized heat exchanger in which two fluids air and water are. These types of towers are used only by utility power stations. 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. Feb 25, 2019 cooling towers are a special type of heat exchanger that allows water and air to come in contact with each other to lower the temperature of the hot water. The main downside is the same downside for most air condensed systems. 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.
The following are the cooling tower parts details including the cooling tower parts name and their functions. Determine the temperature difference between the water entering the cooling tower and the water exiting the cooling tower. For large cooling towers especially power plants, water treatment is the key area for energy conservation. Cooling towers are a special type of heat exchanger that allows water and air to come in contact with each other to lower the temperature of the hot water. Drift eliminators are installed to prevent water entrained in the air from leaving the system. Imagine for a moment that you are an engineer at the turn of the century working for a large. The cooling tower must be adequately sized to reject this same amount of. To rotate fan, it uses motor with speed around rpm. Calculation of effect of cycles of concentration on amount. Technical reference for water conservation in cooling towers. Cooling tower fundamentals is devoted to the implementation of water cooling systems which satisfy design and environmental requirements with sound engineering and responsible cost. Air intake louver is a part of the cooling tower that serves as a.
Working principle is same as natural draught cooling tower, only difference is that here fan is mounted on the cooling tower. The warm moist air is drawn to the top of the cooling tower by the fan and discharged to the atmosphere. Best management practice and guidance manual for cooling towers. The efficiency of cooling tower depends on air and water flow rates and operating temperatures. As the hot cooling water from exchangers may have explosive gas if a heat exchanger is leaky. The hot water that is to be cooled in the cooling tower is pumped to the top of the cooling tower at the hot water inlet. Download the working principle of cooling tower pdf.
Working in sales, he was a technical writer tasked with responding to requests for. As the water evaporates, the air absorbs heat, which lowers the temperature of the remaining water. What is the working principle in the cooling tower. Factors affecting cooling tower performance range, flow and heat load range is a direct function of the quantity of water circulated and the heat load. The environment is friendly because when the hot water is cooled, the towers produce. It works with all types of cooling towers and with different types of fill splash or film. The water leaving a cooling tower will never be as cool as the air entering the tower, but it comes close. 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. What is a cooling towers working principle, water cooling towers are widely used for thermal comfort in hospitals and hotels as well as in industrial areas. The water from a storage tank is directly supplied to the engine cylinder.
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. Most cooling towers work based on the principle of evaporative. Cooling towers are a special type of heat exchanger that allows water and air. 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. Various researchers have carried out studies and investigation on various aspects of cooling tower which influence the effectiveness and working of cooling towers.
This process provides significant cooling to the remaining water stream that. Air enters at the ambient condition point a, absorbs heat and mass moisture from the water. The cooling tower moves heat from the water to the exhausting air thru evaporation. 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 difference between the leaving water temperature and the entering air wet bulb temperature is called the approach. The cooled water drains to the basin at the bottom of the tower and is returned to the heat source. This is why it is known as crossflow as the water, and the air traverses its path. Management of cooling tower blow down is necessary to prevent fouling and efficiently use the makeup water resource. As the name implies, in an indirect cooling tower also known as dry and closed circuit the. By using water only on peak days, the acs coolercondenser can often reduce water consumption to 20% of a conventional water cooled system and. Technical reference for water conservation in cooling towers 1st edition. Cooling tower fundamentals spx cooling technologies. The resulting lower temperature cooling water is returned to the condenser, and the amount of water that. While we use crossflow cooling tower systems, the water in it moves vertically through the fill media, and the air in it runs horizontally across the dropping water.
Typical closed loop cooling tower system is shown in figure 7. How to calculate tons of cooling for a cooling tower. When power plant runs on peak load, it requires a very high rate of cooling water. The hot water is not cooled for reuse but simply discharges. A small portion of the water is evaporated which removes the heat from the remaining water.
Saving water is important, but it must be balanced with the total cost of operation. 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 drybulb air temperature. The hybrid cooling tower can serve not only as a dry heat exchanger but also as a wet cooling tower. Cooling tower design calculation software videosmultiprogram. Preventive maintenance program and plan for cooling towers. As this occurs, a small volume of water is evaporated, reducing the temperature of the water being circulated through the tower. They reject process heat from the cooling water to atmosphere and keep the water cool. The hot water is usually caused by air conditioning condensers or other industrial processe. Cooling towers are also divided by the relative flow relationship of air and water. If you read this book carefully, you can make any cooling tower design programs by yourself. In a short summary, the purpose of a cooling tower is to cool down water that gets heated up by industrial equipment and processes. A centrifugal pump moves water, known as condenser water, between the chiller in the basement and the cooling tower on the roof. Jul 30, 2018 working principle is same as natural draught cooling tower, only difference is that here fan is mounted on the cooling tower. By using water only on peak days, the acs coolercondenser can often reduce water consumption to 20%.
Cooling tower parts components functions sara cooling tower. During the cooling tower working process, small volumes of water evaporate, lowering the. Pdf industrial cooling tower design and operation in the moderate. How cooling towers work working principle cool cooling water is pumped from the cooling tower basin to the process. The cool cooling water is heated by the process and its temperature increases. Herzog working paper massachusetts institute of technology energy initiative. Natural draft cooling towers are generally preferred in. Cooling tower efficiency calculations cooling tower approach. A psychromehic analysis of the air passing through a cooling tower illustrates this effect figure 2. Best management practice and guidance manual for cooling. Cooling towers may either use the evaporation of water to remove process heat and cool the working fluid to. Consider the cooling tower on top of a typical office type building. The guntner adiabatic cooling system acs with hydroblu technology is an advanced cooler or condenser utilizing the latest in heat transfer and controls technology. Increasing the range as a result of added heat requires an increase in tower size.
Because air can absorb less heat than water, adiabatic cooling towers take more energy to accomplish the same reduction in temperature as an evaporative cooling tower. An introduction to water cooling towers ced engineering. Jan 08, 2019 how cooling towers work working principle cool cooling water is pumped from the cooling tower basin to the process. Cooling tower evaporative cooling system measurement and. You could see the location of the cooling tower parts and how they are connected. In this case working fluid passes through a tube bundle upon which clean water is sprayed and a faninduced draft applied. What is the cooling tower and how does it works in hindi. If the hot water temp is constant and the range is specified with a lower cold water temp, then the tower. In a cooling tower, the water enters warm and leaves cooler, and the air enters cool and leaves warmer. The three key components of a cooling system are the cooling tower, recirculating pump, and heat exchanger. Cooling water treatment for controlling suspended solids, algae growth, etc.
Cooling tower efficiency calculations cooling tower efficiency calculation is described in this article. As the water flows through the cooling tower, it is exposed to air, which is being pulled through the tower by the electric motordriven fan. Cooling towers are devices used to transfer heat or cool water for reuse. Oct 02, 2016 consider the cooling tower on top of a typical office type building. Cool and humid climates low wetbulb temperature and high relative humidity heavy winter loads working principle of natural draft cooling towers.
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