An ultrasonic atomization flash evaporation cooling tower

Abstract

The present invention discloses an ultrasonic atomization flash evaporation cooling tower, which includes a first heat exchanger, a negative pressure fan, a second heat exchanger, a sump, a flow distribution plate, an ultrasonic atomizer and an enclosed housing; the inlet of the first heat exchanger is connected to the fluid to be cooled for pre-cooling the hot fluid; the second heat exchanger is connected to the first heat exchanger; a negative pressure fan is included between the first heat exchanger and the second heat exchanger; the sump is located at the lower end of the ultrasonic atomization flash evaporation cooling tower; the ultrasonic atomizer is located inside the sump for atomizing the water in the sump. In the present invention, micron-sized atomized water droplets undergo a phase change under negative pressure conditions to absorb the heat in the enclosed housing, reducing the air temperature around the heat exchanger. Compared with the existing cooling technologies, on the one hand, the heat transfer capacity of the cooling tower is improved, thereby reducing the heat transfer area and the initial investment, and on the other hand, the application range of the refrigeration system can be expanded, which is beneficial to the popularization and application of the natural refrigerant CO2.

Description

Technical Field

[0001] The present invention relates to the technical field of enhanced heat transfer, and particularly to an ultrasonic atomization flash evaporation cooling tower. Background Art

[0002] A cooling tower belongs to a kind of heat exchanger and can condense high-temperature steam into a liquid state. As one of the main components of a refrigeration system, the cooling tower has a very wide range of applications, and its heat dissipation performance directly affects the overall working performance of the device.

[0003] Currently, the commonly used cooling methods in the refrigeration field are air-cooled condensers, water-cooled condensers, and evaporative condensers. The air-cooled condenser has a low heat transfer efficiency, a large volume of the condenser, and the outlet temperature of the condensing refrigerant is greatly affected by the ambient temperature of the location where it is located, but the heat transfer efficiency decay is small and it belongs to the category of single-phase convective heat transfer; the water-cooled condenser has a higher heat transfer efficiency and a small volume, but it is necessary to provide the pump power to overcome the internal resistance of the (shell-type or plate-type) heat exchanger and the pipe resistance to make it flow. If the cooling water is an independent closed-loop system, a cooling tower must also be added. The outlet temperature of the condensing refrigerant is less affected by the ambient atmosphere of the location where it is located, and the heat transfer efficiency decay is small, and it also belongs to the category of single-phase convective heat transfer; the evaporative condenser combines a heat exchanger and a cooling tower. Compared with the water-cooled condenser of an independent closed-loop cooling water system with a cooling tower, it has a small volume. The heat exchanger of the evaporative condenser has no internal resistance to the cooling water, and the pipe resistance of the water is very small, so the pump power is small. The cooled water and the heat exchanger perform phase change convective heat transfer, and the heat transfer efficiency is very high. Currently, all evaporative condensers use relatively low-temperature cooling water to condense the gas of high-temperature condensing refrigerant, which will cause the cooling water to evaporate (vaporize) very quickly, resulting in rapid fouling and algae growth on the surface of the heat exchanger. Although an electronic processor is added, the effect is not obvious, which seriously affects the heat transfer efficiency of the evaporative condenser.

[0004] An ultrasonic atomization flash evaporation cooling tower proposed by the present invention uses the phase change of water droplets atomized by an ultrasonic atomizer to cool the flowing refrigerant in the heat exchanger. On the one hand, the micron-sized water droplets absorb heat during phase change, improving the cooling effect; on the other hand, the ultrasonic atomizer can solidify the impurities in the water, thus avoiding fouling on the surface of the heat exchanger, and thereby extending the service life of the cooling tower. Summary of the Invention

[0005] The main technical problem to be solved by the present invention is to propose an ultrasonic atomization flash evaporation cooling tower that uses the phase change of water droplets atomized by an ultrasonic atomizer to cool the flowing refrigerant in the heat exchanger.

[0006] To solve the above technical problems, a technical solution adopted by the present invention is to provide an ultrasonic atomization flash evaporation cooling tower, which includes a first heat exchanger, a negative pressure fan, a second heat exchanger, a sump, a flow distribution plate, an ultrasonic atomizer and an enclosed housing; the inlet of the first heat exchanger is connected to the fluid to be cooled for pre-cooling the hot fluid; the second heat exchanger is connected to the first heat exchanger; a negative pressure fan is included between the first heat exchanger and the second heat exchanger; the sump is located at the lower end of the ultrasonic atomization flash evaporation cooling tower; the ultrasonic atomizer is located inside the sump for atomizing the water in the sump.

[0007] Compared with the prior art, the present invention has the following beneficial effects:

[0008] In the present invention, micron-sized atomized water droplets undergo a phase change to absorb the heat inside the enclosed housing, thereby reducing the air temperature around the heat exchanger. The air temperature around the heat exchanger can be made to approach the local wet-bulb temperature to the greatest extent. Compared with the existing cooling technologies, a lower cooling temperature can be obtained.

[0009] The heat exchanger of the present invention is divided into two parts. One part serves as the main heat exchanger to condense high-temperature steam into a liquid state, and the other part serves as pre-condensation. By making full use of the atomized water droplets, the superheated steam is pre-cooled. While saving energy, a better cooling effect is achieved.

[0010] In the present invention, the ultrasonic atomizer is used to atomize water droplets. During the atomization process, the scaling components in the water can be solidified on the atomizer and then centrally processed, thereby reducing the scaling of the cooling tower itself and keeping the cooling tower in an efficient heat exchange state all the time. Description of the Drawings

[0011] Figure 1 It is a schematic diagram of an ultrasonic atomization flash evaporation cooling tower;

[0012] In the figure: 1, the first heat exchanger; 2, the negative pressure fan; 3, the second heat exchanger; 4, the flow distribution plate; 5, the ultrasonic atomizer; 6, the sump; 7, the enclosed housing. Detailed Embodiments

[0013] The principles and systems of the present invention will be further described below in conjunction with the drawings and through embodiments. It should be noted that this embodiment is narrative rather than restrictive, and does not limit the protection scope of the present invention.

[0014] An ultrasonic atomization flash evaporation cooling tower of the present invention includes a first heat exchanger (1), a negative pressure fan (2), a second heat exchanger (3), a sump (6), a flow distribution plate (4), an ultrasonic atomizer (5) and an enclosed housing (7); the inlet of the first heat exchanger (1) is connected to the fluid to be cooled, and is used for pre-cooling the hot fluid; the second heat exchanger (3) is connected to the first heat exchanger (1); a negative pressure fan (2) is included between the first heat exchanger (1) and the second heat exchanger (3); the sump (6) is located at the lower end of the ultrasonic atomization flash evaporation cooling tower; the ultrasonic atomizer (5) is located inside the sump (6) and is used for atomizing the water in the sump.

[0015] As an embodiment, the ultrasonic atomization flash evaporation cooling tower mentioned in the present invention is used to cool the superheated CO2 gas of the CO2 subcritical refrigeration system. The operating environment of the CO2 subcritical refrigeration system is 32°C, relative humidity 30%, and 1 standard atmosphere. The ultrasonic atomizer atomizes the water in the sump into liquid droplets with a diameter of 5 μm. Under the action of the negative pressure fan, the atomized water droplets pass through the flow distribution plate and are evenly distributed in the enclosed housing. Part of the atomized liquid droplets adhere to the surface of the second heat exchanger and exchange heat with the CO2 fluid in the second heat exchanger through heat conduction. Part of the atomized liquid droplets float in the air and exchange heat with the second heat exchanger through radiative heat transfer. Since there are enough atomized liquid droplets in the enclosed housing and it is in a negative pressure state, the atomized water droplets are more likely to absorb heat and undergo a phase change. The temperature in the enclosed housing is 18°C, which is 14°C lower than the local ambient temperature. The fluid in the enclosed housing that has completed heat exchange with the second heat exchanger is under the action of the negative pressure fan and comes into full contact with the first heat exchanger again, and exchanges heat with the first heat exchanger and the CO2 fluid in the heat exchanger through heat conduction, convection and radiative heat transfer, so as to make full use of the heat exchange capacity of the atomized air flow and achieve an energy-saving effect.

[0016] In this embodiment, the latent heat of phase change of liquid water under negative pressure conditions is fully utilized to control the temperature in the enclosed housing at 18°C, which is 14°C lower than the local ambient temperature. On the one hand, it improves the heat exchange capacity of the cooling tower, thereby reducing the heat exchange area and the initial investment. On the other hand, it can expand the application range of the refrigeration system and is conducive to the popularization and application of the natural refrigerant CO2.

[0017] The above are only embodiments of the present invention, and do not limit the patent scope of the present invention accordingly. Any equivalent structure or equivalent process transformation made by using the content of the specification and drawings of the present invention, or directly or indirectly applied to other related technical fields, shall be similarly included in the patent protection scope of the present invention.

Claims

1. An ultrasonic atomization flash evaporation cooling tower, characterized in that, It includes a first heat exchanger (1), a negative pressure fan (2), a second heat exchanger (3), a sump (6), a flow distribution plate (4), an ultrasonic atomizer (5) and an enclosed housing (7); the inlet of the first heat exchanger (1) is connected to the fluid to be cooled for pre-cooling the hot fluid; the second heat exchanger (3) is connected to the first heat exchanger (1); a negative pressure fan (2) is included between the first heat exchanger (1) and the second heat exchanger (3); the sump (6) is located at the lower end of the ultrasonic atomization flash cooling tower; the ultrasonic atomizer (5) is located inside the sump (6) for atomizing the water in the sump.

2. The ultrasonic atomization flash evaporation cooling tower according to claim 1, characterized in that: An air outlet is provided at the top of the enclosed housing (7).

3. The ultrasonic atomization flash evaporation cooling tower according to claim 1, wherein: The atomized water droplets of the ultrasonic atomizer (5) have a diameter within 10 μm.

4. An ultrasonic atomization flash evaporation cooling tower according to claim 1, characterized in that: The flow distribution plate (4) is evenly provided with holes with a diameter within 2 cm to promote the flow of the atomized water droplets in the housing.

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