Usually it's a big container, which contains something that needs to be cooled, and then it keeps dripping outside. Anyway, it is cooled by the physical principle of evaporation and heat absorption.
1, cooling tower
In industry, a device for cooling hot water. Water is transported to the tower to exchange heat or heat and mass with air, thus reducing the water temperature.
2. Wet cooling tower
A cooling tower in which water and air directly contact and exchange heat and mass at the same time.
3. Dry cooling tower
There is no direct contact between water and air, only the cooling tower exchanges heat.
4. Dry and wet cooling tower
A cooling tower consisting of dry and wet parts.
5. Natural ventilation cooling tower with natural ventilation
A cooling tower that uses air convection ventilation formed by air density difference inside and outside the tower or natural wind.
6. Mechanical ventilation cooling tower with mechanical ventilation
A cooling tower ventilated by wind.
7. Chimney cooling tower of air duct cooling tower
The cooling tower has geometric lines such as hyperbola, cylinder and polygon, and has a certain height of ram.
8. Open cooling tower
There is no air duct, and the ventilation of cooling tower depends entirely on natural wind. A cooling tower with louvers is arranged around the drenching filler.
9. Mechanical cooling tower of induced draft fan
The fan is installed in the cooling tower at the air outlet of the cooling tower.
10, forced ventilation mechanical cooling tower with forced mechanical ventilation
The fan is installed in the cooling tower at the air inlet of the cooling tower.
1 1, cross-flow cooling tower
The water flow falls vertically from the upper part of the tower, and the air flows horizontally through the cooling tower filled with water, and the air flow is orthogonal to the water flow.
12 countercurrent cooling tower
A cooling tower in which the water flows vertically in the tower and the air flow direction is opposite to the water flow direction.
13, closed cooling tower of closed cooling tower
Using the self-circulating water in the cooling tower to cool the circulating water in the copper tube can ensure the water quality of the circulating water in the copper tube.
Working principle of cooling tower
Cooling tower is a kind of equipment that uses the contact between water and air to dissipate the waste heat generated in industry or refrigeration and air conditioning through evaporation. The basic principle is that dry (low enthalpy) air enters the cooling tower from the air inlet network after being twitched by the fan; High temperature water molecules with high partial pressure of saturated steam flow to the air with low pressure, and hot and humid (high enthalpy) water is sprinkled into the tower from the water seeding system. When water drops contact with air, on the one hand, due to the direct heat transfer between air and water, on the other hand, due to the pressure difference between water vapor surface and air, evaporation occurs under the action of pressure, which takes away the latent heat of evaporation at present, that is, evaporation heat transfer is taken away. So as to achieve the purpose of cooling. Working process of cooling tower: for example, the working process of circulating counter-current cooling tower: hot water is pumped from the main engine room into the water sowing system of the cooling tower through pipes, horizontal throats, curved throats and central throats under a certain pressure by a water pump, and the water is evenly sprinkled on the filler through small holes in the water sowing pipe; Dry air with low Han value enters the air network from the bottom of the tower under the action of the fan. When hot water flows over the surface of the packing, a water film will be formed to exchange heat with air. Hot air with high humidity and high Han value is extracted from the top, and cooling water drops into the bottom basin and flows into the main engine through the outlet pipe. Usually, the air entering the tower is dry air with low wet bulb temperature. Obviously, there is a concentration difference and kinetic energy pressure difference between water and air. When the fan is running, under the action of static pressure in the tower, water molecules are constantly evaporated into the air to become water vapor molecules, and the average kinetic energy of the remaining water molecules will be reduced, thus reducing the temperature of circulating water. From the above analysis, it can be seen that evaporative cooling has nothing to do with whether the air temperature (usually called dry bulb temperature) is lower than or higher than the water temperature. As long as water molecules can continuously evaporate into the air, the water temperature will drop. However, the evaporation of water into the air will not continue indefinitely. When the air in contact with water is not saturated, water molecules evaporate into the air continuously, but when the air in contact with water and gas is saturated, water molecules cannot evaporate, but are in a dynamic equilibrium state. The number of water molecules evaporated is equal to the number of water molecules returned from the air to the water, and the water temperature remains unchanged. It can be seen that the drier the air in contact with water, the easier it is to evaporate and the easier it is to lower the water temperature.
Classification of cooling towers
First, according to the ventilation mode, it is divided into natural ventilation cooling tower, mechanical ventilation cooling tower and mixed ventilation cooling tower.
Second, according to the contact mode between hot water and air, there are wet cooling towers, dry cooling towers and dry-wet cooling towers.
According to the flow direction of hot water and air, there are countercurrent cooling towers, cross-flow cooling towers and mixed-flow cooling towers.
Four, according to the use of general air conditioning cooling tower, industrial cooling tower, high temperature cooling tower.
Five, according to the noise level is divided into ordinary cooling tower, low noise cooling tower, ultra-low noise cooling tower and ultra-quiet cooling tower.
Others such as jet cooling tower, fanless cooling tower, hyperbolic cooling tower, etc.
Scope of application of cooling tower
Waste heat generated in industrial production or refrigeration is generally taken away by cooling water. The function of the cooling tower is to exchange heat with the air in the tower, so that the residual heat can be transferred to the air and dispersed into the atmosphere. For example, in thermal power plants, the boiler heats water into high-temperature and high-pressure steam, which drives the steam turbine to do work and makes the generator generate electricity. The waste steam after the steam turbine does work is discharged into the condenser, which exchanges heat with cooling water and condenses into water. And then pumped back to the boiler for recycling. In this process, the waste heat of exhaust steam is transferred to cooling water, which makes the water temperature rise. The cooling water with waste heat is transferred to the air in the cooling tower and discharged into the atmosphere from the air duct. Application scope of cooling tower: it is mainly used in air conditioning cooling system, refrigeration series, injection molding, tanning, foaming, power generation, steam turbine, aluminum profile processing, air compressor, industrial water cooling and other fields, with air conditioning being the most widely used.
structural style
In order to save energy, large-scale cooling towers mostly adopt natural ventilation cooling towers, which are composed of ventilation pipes, herringbone columns, ring bases, water spraying devices and tower core materials.
Most ventilators are reinforced concrete hyperbola rotating shells, which have good structural mechanics and hydrodynamic characteristics. The lower edge of the shell is supported on V-shaped or X-shaped inclined columns with equal distance to form the air inlet of the cooling tower. The load of the shell is transferred to the foundation through the inclined column. Foundations are mostly made into inclined circular foundations to bear part of the circumferential tension transmitted by inclined columns, or they can be made into separate single foundations or pile foundations.
The diameter of the throat of the ventilation pipe is the smallest. When the shell is calculated to be stable under pressure, the wall of the shell is the thinnest, so the upward diameter gradually increases, forming the diffusion section of the airflow outlet. A rigid ring is arranged at the top of the tower, and the shell wall of the lower section gradually expands in a hyperbolic shape, forming a lower ring beam with certain rigidity. The ventilation pipe can also be made into a truncated cone shell or a combined cone shell. Or polygonal tower with steel frame wrapped with wood fender or asbestos cement fender. In a dry cooling tower with a height of1.46m in Schmeihausen Nuclear Power Station, Germany, a tower with net cable structure is adopted, and the tower is covered with aluminum fender and aluminum fender, which has good seismic and wind resistance.
Function of cooling tower
1. Thermal power plants generally have cooling towers, cooling towers, cooling towers, cooling towers and cooling towers. After water is heated, high-pressure gas is generated to drive the turbine to generate electricity, and the remaining gas needs to be cooled. Its working principle is as follows: the water on the cooling tower of power plant is pumped up by pump, and the water is evenly dispersed and dripped through the water distributor. Generally, the height of a cooling tower is tens of meters, like a huge chimney, which can draw air from below. Air and water are mixed with each other.
2. The central air conditioner also has the function of cooling tower to cool the circulating liquid.
3. We also specialize in producing glass fiber reinforced plastic cooling towers, commonly known as cooling towers, cold water towers, cooling towers, glass fiber reinforced plastic towers, water towers and so on. , mainly including square, round, cross-flow, counter-flow and non-packing spray series cooling towers.
Compared with the traditional packing cooling tower, the automatic rotary atomizing cooling tower also has the following incomparable advantages:
1. Because there is no packing, the tower is basically in a hollow state, with small fan resistance and low noise.
2. The efficient water collector produced by our company's patented technology can effectively reduce floating water and save water obviously.
3. The tower adopts streamlined design, with small gap between the fan and the air duct, large air volume, fast wind speed and good cooling effect.
4. The automatic rotary atomizer is made of wear-resistant polymer material, which is corrosion-resistant and has long service life.
5. Modular design is adopted to facilitate transportation, installation and debugging.
6. No blockage, no maintenance, stable and reliable operation. A series of phenomena that affect the performance of packed tower and process system equipment are completely eliminated, such as packing being blocked by impurities in circulating water, aging, deformation, brittle cracking of packing, blocking and falling off of water distribution nozzle, and packing debris blocking pipelines, pumps and heat exchangers. The trouble of frequent cleaning and replacement of packing and water distribution nozzle is completely eliminated.
Liaoyang Shuangjia Fluid Machinery Equipment Co., Ltd.
Second, the equipment composition and working principle
Equipment composition: the automatic rotary atomizing cooling tower is composed of water inlet pipe, automatic rotary atomizer, shell, water reservoir, fan, motor, air inlet window, water collecting tray (water tank), water outlet pipe, bracket, escalator and other parts (see structural schematic diagram).
Note: The above is a description of single tower structure. For different capacities, double-tower and multi-tower structures can be formed.
Working principle: the automatic rotary atomizing cooling tower lowers the water temperature through heat conduction between circulating cooling water and dry cold air and evaporation of circulating cooling water. Circulating cooling water with a certain pressure enters the cooling tower through the water inlet pipe, and is atomized into atomized steam with a diameter of 0. 1mm under the swirl injection of the atomizer, and the reverse thrust generated by the injection drives the automatic rotating device to rotate. Atomized water filled the whole tower. The axial flow fan installed at the top of the tower rotates, and the cold and dry air in the surrounding environment is forcibly sucked into the cooling tower through the air inlet window to carry out mass transfer and heat transfer with circulating cooling water. The atomized water sprayed by the atomizer has a fast flow speed and has the entrainment effect, so that a certain negative pressure is generated around the atomizer, which increases the exhaust air volume and intake air speed of the cooling tower from the surrounding environment and drives the bottom air to flow upward. The mixing and contact of cold air and dry air with water mist is more complete (the gas-water ratio can reach about 1.2), the particles of atomized water flow are further refined, and the diameter can be reduced to 0.01mm. The fully mixed water mist flows upward and is sprayed on the water reservoir installed at the top of the tower, and the water is intercepted and returned to the cooling tower in the form of water curtain, and the heat of air and water is discharged out of the tower through the water reservoir.
As can be seen from the above working process, circulating cooling water has three processes of rising, suspending and falling in the cooling tower. At the same time, there are two processes of downstream cooling and countercurrent cooling, so the contact time with cold air and dry air is longer and more sufficient, and more heat is taken away. At the same time, due to the cancellation of packing, there is no air resistance phenomenon, which reduces the power of the motor driving the fan to rotate, and achieves the effects of reducing the operating cost and improving the temperature difference between inlet and outlet water. The contact area between water and air after atomization far exceeds that of packed cooling tower. Based on these points, the atomization cooling tower has higher heat exchange efficiency, smaller motor power fan model and more obvious energy saving effect.