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. 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. This airflow is generated by fans powered by electric motors. The mixing of warm water and cooler air releases latent heat of vaporization, causing a. Water to be cooled is distributed in the tower by spray. In practice, the cooling tower efficiency will be in between 65 to 70%. What is the cooling tower and how does it works in hindi. Cooling tower systems include all components that provide comfort cooling by rejecting heat to the atmosphere through the evaporative process.
It is a large tall hyperboloid type cooling tower having widemouthed. 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 are an integral component of many cooling systems that provide comfort or process cooling. Cooling tower evaporative cooling system measurement. Water consumption is an ever increasing important criterion for choosing equipment. To rotate fan, it uses motor with speed around rpm. Range range is determined not by the cooling tower, but by the process it is serving.
See the more detailed explanation of cooling towers systems. Lab 1b cooling tower performance and sensors for thermal. Understand the working principle and types of cooling. Section b is devoted to cooling tower theory and calculations. Other factors, which we will see, must be stated along with flow rate m3hr. Application of this principle to the design of large cooling towers has resulted in extremely stable performance levels for critical projects.
As a consequence of this operating principle, there is a possibility. Wetting pads, thin film fill, plastic mesh and mist nozzles are commonly used to create enough surface air for the water to quickly and completely evaporate. When power plant runs on peak load, it requires a very high rate of cooling water. The air and water mixture releases latent heat of vaporization which has a. Course contents evaporative coolers, often called swamp coolers, are cooling systems that use only water and a blower to circulate air. In this type of cooling tower the water to be cooled is distributed evenly over a packing, which is ventilated from below with air.
This report is available at no cost from the national renewable energy laboratory at. Cooling tower principle evaporation results in cooling on a warm day when you work or play hard, your body heats up, and you begin to sweat. The cooling tower is one of the most important device in industries for example when the hot water come from the heat exchanger in hvac we can use condenser we use the cooling tower to. The evaporator cooling technology is an energyefficient alternative to compressorbased cooling. The environment is friendly because when the hot water is cooled, the towers produce. Cooling towers are a very important part of many chemical plants. The basic cooling tower process is outlined in figure 1. However, due to variations in the water source and their operating in an. Cooling tower basics calculation formulas cooling tower. Principle of operation shree matangi cooling towers pvt. What is the working principle in the cooling tower. 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 atmosphere using relatively cool and dry air. 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. Here we explain in full detail how cooling towers operate with example text, pictures, diagrams and principles.
A cooling tower cools water by a combination of heat and mass transfer. The fundamental principal employed in accomplishing this removal of heat is the evaporation of water. Rate of evaporation is increased by increasing air velocity. The height of the cooling tower in thermal power plant is about 9 feet or above from the ground level. Cooling tower operation forced draught cooling towers use the evaporation of a liquid often water into air to achieve cooling. Download the working principle of cooling tower pdf. This is why it is known as crossflow as the water, and the air traverses its path. 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. Cooling tower fundamentals is devoted to the implementation of water cooling systems which satisfy design and environmental requirements with sound engineering and responsible cost. There are many different types of cooling towers but the cooling tower working principles stay pretty much the same. On evaporation of water, both heat and mass transfer takes place, and water gets cooled. Pdf 60 m3h nominal capacity cooling tower was designed, based on the required cooling water parameters in process of the adhesive production in the. Optimum design and operation of an hvac cooling tower.
A cooling tower is an open direct contact type heat exchanger where hot water from system or condenser gets cooled by direct contact with fresh air. The basic principle of the cooling tower operation is that of evaporative condensation and exchange of sensible heat. A cooling tower is heat removal device that uses water to transfer process waste heat into the atmosphere. Hilton h891 bench top cooling tower and its operating principles. For the sake of this document, cooling tower systems include open recirculating circuit coolers, fluid coolers, and evaporative coolers, closed. Hyperboloid shape aids in accelerating the upward convective air flow, which improves cooling efficiency. Cooling tower fundamentals spx cooling technologies. Natural draught tower utilize the principle of buoyancy to achieve the desired effect.
When warm, dry unsaturated air is pulled through a watersoaked pad, water is evaporated and is absorbed as water vapor into the air. Adiabatic cooling systems work on the same principle, but use a variety of means to precool the air before it flows through the coil. 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. Cooling tower evaporative cooling system measurement and.
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. Because your skin is more moist than the air, the sweat evaporates and it absorbs heat from your body. Though it is widely used in different engineering sector and other refrigeration plant. Cooling towers can be split into two distinct categories. Water to be cooled is distributed in the tower by spray noz zles, splash bars, or filmtype fill, which exposes a very large water surface area to atmospheric air. For example, a cooling tower sized to cool 4540 m 3hr through a. 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. As this occurs, a small volume of water is evaporated, reducing the temperature of the water being circulated through the tower. The primary task of a cool ing tower is to reject heat into the atmosphere.
This video explains how cooling towers work and the working principle behind all wet type cooling towers. Most cooling towers work based on the principle of evaporative cooling. Operation principle of cooling tower youtube a cooling tower is a heat rejection device. Technical reference for water conservation in cooling towers 1st edition. Cooling tower is an essential piece in most of the chemical process industries and in hvac applications. Working principle is same as natural draught cooling tower, only difference is that here fan is mounted on the cooling tower. Evaporative cooling is the process where warm water from an industrial process is pumped up to the top of the cooling tower where the water distribution system is. Technical reference for water conservation in cooling towers. Pdf design and performance analysis of the cooling tower in the. Introduction the laboratory cooling tower is a cooling tower unit from a commercial air conditioning system used to study the principles of cooling tower operation. Cooling tower systems operation is most efficient when their heat transfer surfaces are clean. 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. In dry and arid regions, evaporative cooling can meet most or all building cooling loads using onefourth the energy of conventional equipment. In this type of cooling tower, fan is used to circulate the air.
Lets understand the basic concept of how does a cooling tower work and what the varieties are there in the market. In summer season the ambient air wet bulb temperature raises when compared to winter season so cooling tower efficiency limiting in summer season. All of the required measured values are acquired by sensors and shown on digital displays. Therefore, it is absolutely necessary to pre cool the water coming out of condenser before using again. In open circuit systems the recirculating water returns to the tower after 1 one ton of refrigeration is equal to 12,000 btuhour. Drift eliminators are installed to prevent water entrained in the air from leaving the system. 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 basic working principle of cooling tower is to cool the hot water with the help of atmospheric air. Cooling towers use the principle of evaporation of water against the air flow. All the cooling towers are working on the principle of water evaporation. It is used in conjunction with a residential size water heater to simulate a cooling tower. The device that comes in use for releasing the heat to the atmosphere is known as cooling tower. The wl 320 wet cooling tower is intended to demonstrate the qualitative and quantitative functioning and characteristic variables of a cooling tower. A cooling tower performs to cool down the water used in the industrial process. Principles of cooling towers all cooling towers operate on the principle of removing heat from water by evaporating a small portion of the water that is circulated through the unit. Cooling tower performance and sensors for thermalfluid systems. In case of cooling tower we call this an air draft. Principle of operation a cooling tower cools water by a combination of heat and mass transfer. Large volumes of air flowing through the heat transfer media help increase the rate of evaporation and cooling capacity of the tower.
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