Micro-channel structured cooling tower packing for high efficiency evaporative cooling and its processing technology

Abstract

The present application relates to the technical field of cooling tower packing processing, in particular to a micro-channel structure cooling tower packing for efficient evaporation cooling and a processing technology thereof, which comprises the following steps: plasma activation treatment is performed on a base material of a body, the power is 280-320 W, and the time is 50-70 s; mold pressing forming: the base material preheated to 105-115 DEG C is placed into a mold with a temperature of 160+ / -5 DEG C, and the pressure is kept at 7-9 MPa for 25-35 s; laser trimming: the edge of the micro-channel unit is scanned by ultraviolet laser after mold pressing forming; spraying coating: a nano-hydrophilic coating is formed on the surface of the body by spraying and infrared curing process. Through the sawtooth corrugation, gentle slope corrugation and transition zone curvature control, the present application completes the airflow turbulence strengthening and water film residence time extension, and achieves the effect of improving the evaporation efficiency compared with the traditional packing. Through the micro-channel network construction, the present application completes the water film global diffusion driven by capillary force, and achieves the effect of improving the water film coverage compared with the traditional honeycomb hole and prolonging the anti-clogging cycle.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of cooling tower filler processing, in particular to a micro-channel structure cooling tower filler for efficient evaporative cooling and a processing technology thereof. BACKGROUND

[0002] In a cooling tower, the most critical part is the cooling tower filler. The function of the filler in the cooling tower is to increase the heat dissipation and prolong the residence time of the cooling water. The forming process of the cooling tower filler mainly includes three links of pretreatment, processing and forming. Polyvinyl chloride is a commonly used base material at present. It is particularly important to remove edge burrs and scratch defects before feeding the base material.

[0003] Application No. CN202110214498.1 discloses a cooling tower filler and a preparation process thereof. The filler includes a cooling layer for cooling liquid, and the cooling layer is provided with a honeycomb-shaped through hole for the convection contact of liquid and air. The filler is made of polyethylene plastic. Under a specific modification process, ceramic micropowder and zinc oxide are modified respectively, then the raw materials are mixed and extruded into a shape. The prepared cooling tower plastic filler has better anti-aging ability and stronger durability.

[0004] In the field of cooling tower fillers, plastic materials gradually replace traditional materials due to their low cost and corrosion resistance, but there are two technical bottlenecks:

[0005] Most existing fillers adopt a honeycomb straight through hole structure, the contact area between water flow and air is limited, and water flow short circuit is easy to form, which makes it difficult to improve the evaporation efficiency and the heat and mass exchange efficiency has a slow improvement space; the traditional extrusion forming process cannot realize micron-level channels, and the edge burr of the channel is >0.1mm, which causes flow deviation and blockage. The existing technology does not solve the above fluid dynamics defects. SUMMARY

[0006] In order to overcome the defects in the prior art, the purpose of the present application is to provide a micro-channel structure cooling tower filler for efficient evaporative cooling and a processing technology thereof. The present application realizes collaborative innovation through bionic micro-channel structure, super-hydrophilic coating and precision forming process, breaks through the bottleneck of evaporation efficiency and service life, and solves the problems raised in the above background technology.

[0007] To achieve the above object, in one aspect, the present application provides a kind of microchannel structure cooling tower filler for high-efficiency evaporative cooling, including the body of cuboid and the front area array of it is equipped with several corrugated units, the front surface of the corrugated unit is equidistantly provided with several microchannel units;The corrugated unit is composed of a pair of sawtooth corrugation and several gentle slope corrugation between them, wherein several gentle slope corrugation is distributed in staggered connection;The included angle of the sawtooth corrugation is 60-75 °, the inclination of the front surface of the corrugated unit is 15-30 °, and the sawtooth corrugation and the gentle slope corrugation and the adjacent gentle slope corrugation are connected by transition corrugation.

[0008] As a further improvement of the technical solution, the depth of the microchannel unit is 0.5-0.8mm, and is a straight groove type or a curved type, the side communication of the microchannel unit is provided with a capillary channel, the depth of the capillary channel is 0.1-0.2mm, and the spacing between adjacent capillary channels is 0.2-0.3mm.

[0009] As a further improvement of the technical solution, the surface of the body is covered with a nano-hydrophilic coating, which is The composite sol is cured to form a coating with a thickness of 5-8 μm and a surface contact angle of <10 °.

[0010] As a further improvement of the technical solution, the base material of the body comprises, by weight: PVC resin 90-100 parts, PVDF 20-25 parts, graphene fiber 4-6 parts, nano 1.5-2.5 parts.

[0011] The above arrangement achieves airflow turbulence enhancement and water film residence time extension through the design of asymmetric corrugated units: sawtooth corrugation 60-75 °, gentle slope corrugation 15-30 ° and transition zone curvature control.

[0012] In another aspect, the present application provides a processing process for a microchannel structure cooling tower filler for high-efficiency evaporative cooling, for preparing the above-mentioned microchannel structure cooling tower filler for high-efficiency evaporative cooling, comprising the following steps:

[0013] S1, base material pretreatment: the base material of the body is subjected to plasma activation treatment, power 280-320 W, time 50-70 s;

[0014] S2, mold forming: the base material preheated to 105-115 °C is placed in a mold at 160 ± 5 °C, and formed at a pressure of 7-9 MPa for 25-35 s;

[0015] S3, laser trimming: the edge of the microchannel unit is scanned by ultraviolet laser after mold forming;

[0016] S4, spraying coating layer: forming a nano-hydrophilic coating layer on the surface of the body by spraying and infrared curing process.

[0017] This process design solves the water flow distribution problem through the micro-channel structure and the laser chamfering process; and long-term hydrophilicity is guaranteed through the plasma treatment and the nano coating.

[0018] As a further improvement of the technical solution, the plasma treatment is carried out in an argon / oxygen mixed atmosphere with a mixing volume ratio of 3:1.

[0019] As a further improvement of the technical solution, the wavelength of the ultraviolet laser used after the mold forming is 355 nm, the laser power is 20-30 W, the scanning speed is 180-220 mm / s, and the pulse frequency is 45-55 kHz.

[0020] As a further improvement of the technical solution, the nano-hydrophilic coating layer is formed by spraying and infrared curing process, the curing temperature is 115-125 DEG C, and the time is 80-100 s.

[0021] As a further improvement of the technical solution, the mold used in the mold forming is made of hard alloy steel material, the micro-channel unit area tolerance is ±0.05 mm, and the surface roughness Ra is ≤0.1 μm.

[0022] As a further improvement of the technical solution, an R0.15-0.25 mm chamfer is formed at the channel inlet after laser trimming.

[0023] Compared with the prior art, the present application has the following beneficial effects:

[0024] 1. The micro-channel structure cooling tower filler for efficient evaporation cooling and its processing technology, through the asymmetric corrugated unit design: sawtooth corrugation, gentle slope corrugation and transition zone curvature control, the airflow turbulence strengthening and water film residence time extension are completed, the evaporation efficiency is improved compared with the traditional filler; through the micro-channel network construction, the water film global diffusion driven by capillary force is completed, the water film coverage rate is improved compared with the traditional honeycomb hole, and the anti-clogging period is prolonged.

[0025] 2. The micro-channel structure cooling tower filler for efficient evaporation cooling and its processing technology, through the ultraviolet laser precision trimming and hard alloy mold forming, the micro-channel inlet chamfering is completed, the flow deviation phenomenon caused by the flash is eliminated, and the flow uniformity is improved. DETAILED DESCRIPTION

[0026] The accompanying drawings described herein are for illustrative purposes only and are not intended to limit the scope of the invention in any way. Furthermore, the shapes and proportions of the components in the drawings are merely illustrative to aid in understanding the invention and do not specifically limit the shapes and proportions of the components. Those skilled in the art, guided by the teachings of this invention, will select various possible shapes and proportions to implement the invention according to specific circumstances.

[0027] Figure 1 This is a schematic diagram of the main body structure of the present invention;

[0028] Figure 2 For the present invention Figure 1 A magnified structural diagram at point A;

[0029] Figure 3 This is the main view of the body of the present invention;

[0030] Figure 4 This is a side view of the main body of the present invention;

[0031] Figure 5 For the present invention Figure 4 A magnified structural diagram at point B;

[0032] Figure 6 This is a flowchart of the body processing technology of the present invention;

[0033] The meanings of the labels in the diagram are as follows:

[0034] 100, Body; 200, Corrugated Unit; 210, Sawtooth Corrugation; 220, Gentle Slope Corrugation; 230, Transition Corrugation; 300, Microchannel Unit. Detailed Implementation

[0035] The details of the present invention can be more clearly understood by referring to the accompanying drawings and the description of specific embodiments. However, the specific embodiments of the present invention described herein are for illustrative purposes only and should not be construed as limiting the invention in any way. Under the teachings of this invention, those skilled in the art will conceive of any possible variations of the invention, all of which should be considered within the scope of the invention. The terms "installation" and "connection" should be interpreted broadly, referring to direct connection as well as indirect connection through an intermediate medium.

[0036] The terms "central axis", "vertical", "horizontal", "front", "back", "upper", "lower", "left", "right", "top", "bottom", "inner", "outer" and the like used herein indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the present application. In addition, in the description of the present application, the meaning of "several" is two or more, unless otherwise explicitly and specifically limited.

[0037] Please refer to Figures 1-6 As shown in the drawings, the present application provides a kind of microchannel structure cooling tower filler for efficient evaporative cooling, including the body 100 of cuboid and the front area array of it is equipped with several corrugated units 200, the front surface of corrugated unit 200 is equidistant and is provided with several microchannel units 300;Corrugated unit 200 is composed of a pair of sawtooth corrugation 210 and several gentle slope corrugation 220 between them, wherein several gentle slope corrugation 220 is distributed in staggered connection;The included angle of sawtooth corrugation 210 is 60°-75°, and sawtooth corrugation 210 is used to enhance turbulent flow, and the inclination of the front surface of corrugated unit 200 is 15°-30°;Gentle slope corrugation 220 is used to prolong the residence time of water film;Sawtooth corrugation 210 and gentle slope corrugation 220 and adjacent gentle slope corrugation 220 are connected by transition corrugation 230, and the curvature radius R of transition corrugation 230 is 0.4-0.6mm, to avoid stress concentration, to solve the problem of uneven air distribution and early water film rupture of traditional filler.

[0038] Further, the depth of microchannel unit 300 is 0.5-0.8mm, and is straight groove type or curve type, for draining main water flow;The side of microchannel unit 300 is connected and is provided with capillary channel, the depth of capillary channel is 0.1-0.2mm, the interval of adjacent capillary channel is 0.2-0.3mm, the water film is diffused by capillary effect, considering that 0.2-0.3mm interval is the critical point of capillary force, when interval > 0.3mm, water film coverage rate decreases, so that the interval of the design optimizes the uniformity of fluid distribution.

[0039] Further, the surface of body 100 is covered with nano hydrophilic coating, the coating is Composite sol is cured to form, the thickness is 5-8 μm, the surface contact angle is < 10°, the superhydrophilic is realized by Wenzel effect;The water flow boundary layer resistance is reduced by coating, so that the evaporation efficiency is improved.

[0040] In addition, the base material of body 100 includes, by weight: PVC resin 90-100 parts, PVDF 20-25 parts, graphene fiber 4-6 parts, nano 1.5-2.5 parts; wherein PVDF improves the temperature resistance of PVC, the Vicat softening point is from 72℃ to 105℃; graphene fiber enhances thermal conductivity; Quenching free radicals delays aging.

[0041] The application also provides a processing process of a micro-channel structure cooling tower filler for efficient evaporative cooling, for preparing the micro-channel structure cooling tower filler for efficient evaporative cooling described above, comprising the following steps:

[0042] S1, substrate pretreatment: the substrate of the body 100 is subjected to plasma activation treatment to increase the surface energy and improve the adhesion of the coating; the power is 280-320 W, and the time is 50-70 s; wherein the plasma treatment is carried out in an argon / oxygen mixed atmosphere, and the mixing volume ratio is 3:1. The mixed atmosphere generates high active oxygen free radicals, etches the substrate to form anchor points, and the coating adhesion is optimal; that is, the coating peeling force is improved by plasma treatment;

[0043] S2, mold forming: the substrate preheated to 105-115℃ is placed into a mold at 160±5℃, so that the PVDF melts and flows to fill the microcavity; forming is carried out at a pressure of 7-9 MPa for 25-35 s; the mold used in mold forming is made of hard alloy steel material, the tolerance of the micro-channel unit 300 region is ±0.05 mm, the surface roughness Ra is ≤0.1 μm, and the subsequent mirror polishing reduces the demolding resistance;

[0044] S3, laser trimming: after mold forming, the edge of the micro-channel unit 300 is scanned by ultraviolet laser; the wavelength of the ultraviolet laser is 355 nm, the 355 nm ultraviolet laser cold machining avoids thermal damage; the laser power is 20-30 W, the scanning speed is 180-220 mm / s, and the pulse frequency is 45-55 kHz; so as to accurately remove the flash and reduce the water flow resistance;

[0045] S4, spraying coating: a nano-hydrophilic coating is formed on the surface of the body 100 by spraying and infrared curing process, the curing temperature is 115-125℃, and the time is 80-100 s; the 115-125℃ infrared curing makes the sol dehydration condensation to form a-Si-O-Si- network, preventing coating failure caused by low temperature curing.

[0046] Further, after laser trimming, a chamfer of R0.15-0.25 mm is formed at the inlet of the channel to reduce the water flow inlet vortex and improve the flow uniformity.

[0047] It should be noted that the fixed connection, fixed with the term of the application adopts the conventional fixing means such as bolt connection or welding. The above-mentioned embodiments are only for illustrating the technical concept and characteristics of the application, and the purpose is to enable the person skilled in the art to understand the content of the application and to implement it, and cannot limit the protection scope of the application. Any equivalent changes or modifications made according to the spirit and principle of the application should be covered within the protection scope of the application.

Claims

1. A microchannel structure cooling tower packing for high-efficiency evaporative cooling, characterized in that, The device includes a rectangular body and several corrugated units arranged in an array on its front surface. The corrugated units are formed by molding. Several microchannel units are evenly spaced on the front surface of each corrugated unit. Each corrugated unit consists of a pair of sawtooth corrugations and several gently sloping corrugations arranged between them, wherein the gently sloping corrugations are staggered and connected. The included angle of the sawtooth corrugations is 60°-75°, and the tilt angle of the front surface of the corrugated unit is 15°-30°. The sawtooth corrugations and the gently sloping corrugations, as well as adjacent gently sloping corrugations, are connected by transition lines. The radius of curvature R of the transition lines is 0.4-0.6 mm. Capillary channels are connected to the sides of each microchannel unit.

2. The microchannel structure cooling tower packing for high-efficiency evaporative cooling according to claim 1, characterized in that: The depth of the microchannel unit is 0.5-0.8 mm, and it is either a straight groove or a curved shape. The depth of the capillary channel is 0.1-0.2 mm, and the spacing between adjacent capillary channels is 0.2-0.3 mm.

3. The microchannel structure cooling tower packing for high-efficiency evaporative cooling according to claim 2, characterized in that: The surface of the body is covered with a nano-hydrophilic coating, which is The composite sol is cured to form a thickness of 5-8 μm and a surface contact angle of <10°.

4. The microchannel structure cooling tower packing for high-efficiency evaporative cooling according to claim 3, characterized in that: The substrate of the body comprises, by weight: 90-100 parts PVC resin, 20-25 parts PVDF, 4-6 parts graphene fiber, and nano-... 1.5-2.5 portions.

5. A processing method for microchannel structure cooling tower packing for high-efficiency evaporative cooling, used to prepare the microchannel structure cooling tower packing for high-efficiency evaporative cooling as described in claim 4, characterized in that, Includes the following steps: S1. Substrate pretreatment: Plasma activation treatment is performed on the substrate of the main body, with a power of 280-320W and a time of 50-70s. S2. Compression molding: The substrate preheated to 105-115℃ is placed into a mold at 160±5℃ and molded under pressure of 7-9MPa for 25-35s. S3, Laser finishing: After molding, the edges of the microchannel units are scanned with an ultraviolet laser; S4. Spray coating: A nano-hydrophilic coating is formed on the surface of the substrate through spraying and infrared curing processes.

6. The processing technology of the microchannel structure cooling tower packing for high-efficiency evaporative cooling according to claim 5, characterized in that: The plasma activation treatment is carried out in a mixed atmosphere of argon and oxygen with a volume ratio of 3:

1.

7. The processing technology of the microchannel structure cooling tower packing for high-efficiency evaporative cooling according to claim 6, characterized in that: After molding, an ultraviolet laser with a wavelength of 355nm, a laser power of 20-30W, a scanning speed of 180-220mm / s, and a pulse frequency of 45-55kHz is used.

8. The processing technology of the microchannel structure cooling tower packing for high-efficiency evaporative cooling according to claim 7, characterized in that: The nano-hydrophilic coating is formed by spraying and infrared curing processes, with a curing temperature of 115-125℃ and a curing time of 80-100s.

9. The processing technology of the microchannel structure cooling tower packing for high-efficiency evaporative cooling according to claim 8, characterized in that: The mold used in the compression molding is made of cemented carbide steel, with a microchannel unit area tolerance of ±0.05mm and a surface roughness Ra≤0.1μm.

10. The processing technology of the microchannel structure cooling tower packing for high-efficiency evaporative cooling according to claim 9, characterized in that: After laser finishing, a chamfer of R0.15-0.25mm is formed at the channel entrance.

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