Mechanical ventilation cooling tower evaporation water recovery system and recovery method

Abstract

The present invention provides a mechanical ventilation cooling tower evaporation water recovery system and a recovery method thereof, comprising a tower body, a water collecting pool is provided at the bottom of the tower body, a filler is provided above the water collecting pool, an air inlet is provided on the side wall of the tower body, the air inlet is provided between the water collecting pool and the filler, an air outlet is provided at the upper end of the tower body, a fan and a ventilation duct device are provided in the air outlet, blades are provided on the fan, the ventilation duct device is provided above the fan, the ventilation duct device includes a ventilation pipe for communicating with external cold air, and an electrostatic water collecting device is provided at the air outlet of the air outlet. The present invention provides a mechanical ventilation cooling tower evaporation water recovery system and a recovery method thereof, adopts a ventilation duct device provided above the fan, automatically sucks the external environment cold air into the air duct, mixes and condenses with the humid and hot air in the tower body to form small water droplets, which are captured and collected when passing through the electrostatic water collecting device, thereby recovering the evaporated water in the air, which can greatly improve the water-saving capacity.

Description

Technical Field

[0001] The invention relates to the technical field of cooling tower water saving, and in particular to an evaporative water recovery system of a mechanical ventilation cooling tower and a recovery method thereof. Background Art

[0002] Cooling towers are key equipment for industrial water use and are widely used in high water-consuming industries such as electricity, steel, and petrochemicals. Their water loss accounts for 70% of industrial water consumption. The evaporative water recovery system of the mechanical ventilation cooling tower and its recovery method are that the fan draws / blows ambient air into the cooling tower, and contacts with the circulating cooling tower carrying industrial waste heat in the water-spraying filler area. Through the evaporation and heat transfer of the circulating water, the waste heat of the circulating cooling water is dissipated to the atmosphere. After the water-spraying filler, the air changes into humid and hot air that is close to saturated heat, which contains evaporated water. This part of water accounts for about 90% of the water consumption of the cooling tower. If part of the evaporated water can be recovered, the water-saving potential will be huge.

[0003] At present, the technology for recovering evaporated water is not mature. Among them, electrostatic recovery of evaporated water is a potential technology. See patent: CN92102424.X. This technology can only recover small liquid water droplets in humid hot air, and cannot produce phase change for water that has changed into steam. Only a very small amount of air is mixed at the air outlet to produce a small amount of liquid water. If the humid hot air in the cooling tower can be liquefied by phase change, it is the key to electrostatic recovery of evaporated water. Summary of the invention

[0004] The technical problem to be solved by the present invention is: in order to overcome the deficiencies in the prior art, the present invention provides a mechanical ventilation cooling tower evaporated water recovery system and a recovery method thereof.

[0005] The technical solution adopted by the present invention to solve its technical problems is: a mechanical ventilation cooling tower evaporation water recovery system and a recovery method thereof, comprising a tower body, a water collecting tank is provided at the bottom of the tower body, a filler is provided above the water collecting tank, an air inlet is provided on the side wall of the tower body, the air inlet is provided between the water collecting tank and the filler, an air outlet is provided at the upper end of the tower body, a fan and a ventilation duct device are provided in the air outlet, blades are provided on the fan, the ventilation duct device is provided above the fan, the ventilation duct device includes a ventilation pipe for communicating with the external cold air, and an electrostatic water collecting device is provided at the upper end of the air outlet.

[0006] A fan is arranged at the air outlet. When the fan is started, the hot and humid air containing evaporated water in the cooling tower can be sucked toward the air outlet. When the fan is started, the cold air from the outside environment can be automatically sucked into the air outlet through the ventilation duct device located in the air outlet. The cold air and the hot air are mixed above the fan blades and condensed into small water droplets. The small water droplets continue to rise under the drive of the airflow. When passing through the electrostatic water collecting device, the small water droplets are captured and collected, thereby recovering the water evaporated in the air.

[0007] Working principle of electrostatic water collection device: electric charges are divided into positive charges and negative charges. The interaction between charges can be attributed to "like repels like, opposites attract". In the molecules of an object, different atoms have different binding abilities to electrons. Therefore, in the entire molecule, due to the different electrical properties of each atom, positive and negative centers will be formed. Molecules with overlapping positive and negative centers are called non-polar molecules; conversely, molecules with non-overlapping positive and negative centers are called polar molecules. A water molecule is a polar molecule. A water molecule consists of one oxygen atom and two hydrogen atoms. The oxygen atom has a stronger ability to bind electrons. Therefore, the oxygen atom is the negative center, and the center of the line connecting the two hydrogen atoms is the positive center. Therefore, the water molecule is a polar molecule. In this way, when the water molecules are subjected to an external electric field, they will move to the plate, forming small water droplets that will be collected and recycled.

[0008] In order to evenly introduce ambient cold air into the cooling tower, the ventilation pipe is an L-shaped pipe, and a plurality of ventilation pipes are evenly distributed radially in the air outlet, and the air outlet of the ventilation pipe is arranged upward. A circle of ventilation pipes is arranged in the air outlet to introduce ambient cold air, and multiple ventilation pipes evenly introduce ambient cold air into the cooling tower, so that the ambient cold air is fully mixed with the humid hot air, which greatly improves the condensation effect of small water droplets.

[0009] Furthermore, the length of the ventilation pipe in the horizontal direction is between one fifth and one half of the blade length. When the fan drives the blade to rotate, the wind force is concentrated in a circle around the top of the blade, that is, the humid and hot gas is concentrated in a circle close to the inner wall of the air outlet. There is basically no gas flow rate in the middle position above the blade, so there is not much humid and hot gas. Even if the ventilation pipe is extended to the middle position above the blade, the conversion of small water droplets will not be significantly improved, and the production cost of the ventilation pipe will increase. Therefore, it is best to set the length of the ventilation pipe between one fifth and one half of the blade length.

[0010] Furthermore, in order to evenly introduce ambient cold air into the cooling tower, the ventilation pipe is a straight pipe arranged in the horizontal direction, and a plurality of ventilation pipes are evenly distributed in the radial direction in the air outlet cylinder. The end of the ventilation pipe away from the side wall of the air outlet cylinder is closed, and an air outlet is arranged on the upper side wall of the ventilation pipe, and the air outlet is a long strip gap or a continuous gap arranged at intervals. A circle of ventilation pipes is arranged in the air outlet cylinder to introduce ambient cold air, and multiple ventilation pipes evenly introduce ambient cold air into the cooling tower, so that the ambient cold air is fully mixed with the humid hot air, which greatly improves the condensation effect of small water droplets.

[0011] Furthermore, the cross-sectional area of ​​the ventilation pipe body gradually decreases from the outside to the inside. On the one hand, as the cold air from the external environment is transmitted to the inside of the air outlet, the gas flow gradually decreases, and the narrowing of the pipe body can have a pressurizing effect, and on the other hand, it can save production materials for the ventilation pipe.

[0012] Furthermore, the length of the ventilation pipe body is between one fifth and one half of the blade length. When the fan drives the blade to rotate, the wind force is concentrated in a circle around the top of the blade, that is, the humid and hot gas is concentrated in a circle close to the inner wall of the air outlet. There is basically no gas flow rate in the middle position above the blade, so there is not much humid and hot gas. Even if the ventilation pipe is extended to the middle position above the blade, the conversion of small water droplets will not be significantly improved, and the production cost of the ventilation pipe will increase. Therefore, it is best to set the length of the ventilation pipe body between one fifth and one half of the blade length.

[0013] Furthermore, in order to evenly introduce ambient cold air into the cooling tower, the ventilation pipe is a straight pipe arranged in the horizontal direction, and a plurality of the ventilation pipes are evenly distributed radially in the air outlet tube. The ventilation pipe is provided with a plurality of concentrically arranged annular air outlet grooves, which are connected to the ventilation pipe, and air outlets are densely distributed above the annular air outlet grooves. The ventilation pipe introduces ambient cold air, and the annular air outlet grooves evenly introduce the ambient cold air into the cooling tower, so that the ambient cold air is fully mixed with the humid hot air, which greatly improves the condensation effect of small water droplets.

[0014] Furthermore, the radius of the annular air outlet groove is between one fifth and one half of the radius of the blade. When the fan drives the blade to rotate, the wind force is concentrated in a circle around the top of the blade, that is, the humid and hot gas is concentrated in a circle close to the inner wall of the air outlet tube. There is basically no gas flow rate in the middle position above the blade, so there is not much humid and hot gas. Even if the ventilation pipe is extended to the middle position above the blade, the conversion of small water droplets will not be significantly improved, and the production cost of the ventilation pipe will increase. Therefore, it is best to set the length of the ventilation pipe body between one fifth and one half of the blade length.

[0015] Furthermore, the cross-sectional shape of the ventilation pipe may be circular, elliptical, rectangular, etc.

[0016] A method for recovering evaporated water from a mechanical ventilation cooling tower, further comprising the following steps:

[0017] Start the fan, and the gas in the tower will flow from the air inlet through the filler to the air outlet. At the same time, the cooler air from the outside environment will be drawn into the tower through the ventilation duct device. The cooler ambient air will be mixed with the hot and humid air, and the hot and humid air will condense to form small water droplets. The small water droplets will be captured when passing through the electrostatic water collecting device at the air outlet of the air outlet, thereby recovering the evaporated water.

[0018] The beneficial effects of the present invention are as follows: a mechanical ventilation cooling tower evaporated water recovery system and a recovery method thereof are provided by the present invention, which adopts the principle that a ventilation duct device is arranged above the fan to form a negative pressure after hindering the airflow in the wind tube, and automatically introduces cold air from the external environment into the tower body, mixes with the hot and humid air in the tower body, condenses to form small water droplets, and is captured and collected when passing through the electrostatic water collection device, thereby achieving efficient recovery of evaporated water and greatly improving the water-saving capacity. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] The present invention will be further described below in conjunction with the accompanying drawings and embodiments.

[0020] Figure 1 It is a schematic diagram of the structure of the best embodiment of the present invention;

[0021] Figure 2 yes Figure 1 Schematic diagram of the cross section of AA;

[0022] Figure 3 is a structural diagram of Embodiment 2;

[0023] Figure 4 yes Figure 3 Schematic cross-section of the middle BB;

[0024] Figure 5 is a schematic diagram of the structure of Embodiment 3;

[0025] Figure 6 yes Figure 5 Schematic cross-section of CC.

[0026] In the figure: 1. tower body, 2. water collecting tank, 3. filler, 4. air inlet, 5. air outlet, 6. fan, 7. ventilation duct device, 7-1. ventilation pipe, 7-2. air outlet, 7-3. annular air outlet slot, 8. electrostatic water collecting device. DETAILED DESCRIPTION

[0027] The present invention will now be described in detail with reference to the accompanying drawings. This figure is a simplified schematic diagram, which only illustrates the basic structure of the present invention in a schematic manner, and therefore only shows the components related to the present invention.

[0028] Embodiment 1:

[0029] like Figure 1-2As shown, a mechanical ventilation cooling tower evaporation water recovery system and recovery method thereof of the present invention comprises a tower body 1, a water collecting tank 2 is provided at the bottom of the tower body 1, a filler 3 is provided above the water collecting tank 2, a plurality of air inlets 4 are provided on the side wall of the tower body 1, the air inlet 4 is provided between the water collecting tank 2 and the filler 3, an air outlet 5 is provided at the upper end of the tower body 1, a fan 6 and a ventilation duct device 7 are provided in the air outlet 5, blades are provided on the fan 6, the ventilation duct device 7 is provided more than 30 cm above the fan 6, the ventilation duct device 7 comprises a ventilation pipe 7-1 for communicating with the external cold air, and an electrostatic water collecting device 8 is provided at the upper end of the air outlet 5.

[0030] The ventilation pipe 7 - 1 is an L-shaped pipe, and sixteen ventilation pipes 7 - 1 are evenly distributed in the air outlet tube 5 along the radial direction, and the air outlet 7 - 2 of the ventilation pipe 7 - 1 is arranged upward.

[0031] The length of the ventilation pipe 7-1 in the horizontal direction is one third of the length of the blade.

[0032] The cross-sectional shape of the ventilation pipe 7-1 is circular.

[0033] Embodiment 2:

[0034] like Figure 3-4 As shown, the difference between this embodiment and the first embodiment is that the ventilation pipe 7-1 is a straight pipe arranged in the horizontal direction, sixteen ventilation pipes 7-1 are evenly distributed radially in the air outlet tube 5, one end of the ventilation pipe 7-1 away from the side wall of the air outlet tube 5 is closed, and an air outlet 7-2 is provided on the upper side wall of the ventilation pipe 7-1, and the air outlet 7-2 is a long strip gap.

[0035] The cross-sectional area of ​​the ventilation pipe 7-1 gradually decreases from the outside to the inside.

[0036] The length of the ventilation pipe 7-1 is one third of the length of the blade.

[0037] The cross-sectional shape of the ventilation pipe 7-1 can be circular.

[0038] Embodiment three:

[0039] like Figure 5-6 As shown, the difference between this embodiment and the first embodiment is that the ventilation pipe 7-1 is a straight pipe arranged in the horizontal direction, four ventilation pipes 7-1 are evenly distributed radially in the air outlet tube 5, and three concentrically arranged annular air outlet grooves 7-3 are provided on the ventilation pipe 7-1. The three annular air outlet grooves 7-3 are all connected to the ventilation pipe 7-1, and the annular air outlet grooves 7-3 are densely distributed with air outlets 7-2 above them.

[0040] The radius length of the annular air outlet slot 7-3 is between one fifth and one half of the radius length of the blade.

[0041] The cross-sectional shape of the ventilation pipe 7-1 can be rectangular.

[0042] Working method:

[0043] Start the fan 6, and the gas flows from the air inlet 4 through the filler 3 toward the air outlet 5, where it exchanges heat and mass with the circulating water, generating hot and humid air containing evaporated water that flows toward the air outlet. The ventilation duct device 7 in the air outlet 5 automatically draws cold air from the outside into the air outlet, and the cooler ambient air is mixed with the hot and humid air. The hot and humid air condenses to form small water droplets, which move upward under the drive of the air flow. When the small water droplets pass through the air outlet 7-2 of the air outlet 5, they are captured and collected by the electrostatic water collecting device 8, thereby recovering the evaporated water.

[0044] Directions and references (e.g., up, down, left, right, etc.) in the present invention may only be used to assist in the description of features in the accompanying drawings. Therefore, the following detailed description is not to be taken in a limiting sense, and the scope of the subject matter claimed is limited only by the attached claims and their equivalents.

[0045] Based on the above ideal embodiments of the present invention, the relevant staff can make various changes and modifications without departing from the scope of the present invention through the above description. The technical scope of this invention is not limited to the contents of the specification, and its technical scope must be determined according to the scope of the claims.

Claims

1. A method for recovering evaporated water from a mechanical ventilation cooling tower, characterized in that: The invention comprises an evaporative water recovery system for a mechanical ventilation cooling tower, wherein the evaporative water recovery system for the mechanical ventilation cooling tower comprises a tower body (1), a water collecting pool (2) is provided at the bottom of the tower body (1), a filler (3) is provided above the water collecting pool (2), an air inlet (4) is provided on the side wall of the tower body (1), the air inlet (4) is arranged between the water collecting pool (2) and the filler (3), an air outlet cylinder (5) is provided at the upper end of the tower body (1), a fan (6) and a ventilation duct device (7) are arranged in the air outlet cylinder (5), blades are provided on the fan (6), the ventilation duct device (7) is arranged above the fan (6), the ventilation duct device (7) comprises a ventilation duct for communicating with external cold air, the cross-sectional shape of the ventilation duct is circular, elliptical or rectangular, an electrostatic water collecting device (8) is provided at the upper end of the air outlet cylinder (5), Wherein, the ventilation pipe is an L-shaped pipe, and the ventilation pipe air outlet (7-2) is arranged upward; or the ventilation pipe is a straight pipe arranged in the horizontal direction, and one end of the ventilation pipe away from the side wall of the air outlet cylinder (5) is sealed, and the upper side wall of the ventilation pipe is provided with an air outlet (7-2); or the ventilation pipe is a straight pipe arranged in the horizontal direction, and the ventilation pipe is provided with a plurality of concentrically arranged annular air outlet grooves (7-3), the annular air outlet grooves (7-3) are connected to the ventilation pipe, and the air outlets (7-2) are densely distributed above the annular air outlet grooves (7-3); The recovery method further comprises the following steps: The fan (6) is started, and the gas in the tower body (1) flows from the air inlet (4) through the filler (3) toward the air outlet (5), and heat and mass exchange occurs with the circulating water at the water-sprayed filler (3), so that the air is changed into humid hot air and flows out from the outlet of the air outlet (5). The ventilation duct device (7) arranged on the air outlet (5) automatically draws cold air outside the tower into the air outlet (5), and the cold air is mixed with the humid hot air, and the humid hot air condenses to form small water droplets. The small water droplets are captured when passing through the electrostatic water collection device (8) at the air outlet (7-2) of the air outlet (5), thereby recovering evaporated water.

2. The method for recovering evaporated water from a mechanical ventilation cooling tower as claimed in claim 1, wherein: The ventilation pipe is the L-shaped pipe, and a plurality of the ventilation pipes are evenly distributed radially in the air outlet cylinder (5). The length of the ventilation pipe in the horizontal direction is between one fifth and one half of the length of the blade.

3. The method for recovering evaporated water from a mechanical ventilation cooling tower as claimed in claim 1, wherein: The ventilation pipe is a straight pipe arranged in the horizontal direction. A plurality of the ventilation pipes are evenly distributed in the radial direction in the air outlet tube (5). The end of the ventilation pipe away from the side wall of the air outlet tube (5) is sealed. The upper side wall of the ventilation pipe is provided with the air outlet (7-2). The air outlet (7-2) is a long strip-shaped gap or a continuous gap arranged at intervals. The cross-sectional area of ​​the ventilation pipe body gradually decreases from the outside to the inside. The length of the ventilation pipe body is between one fifth and one half of the length of the blade.

4. The method for recovering evaporated water from a mechanical ventilation cooling tower as claimed in claim 1, wherein: The ventilation pipe is a straight pipe arranged in the horizontal direction. A plurality of the ventilation pipes are evenly distributed radially in the air outlet cylinder (5). The ventilation pipe is provided with a plurality of concentrically arranged annular air outlet grooves (7-3). The radius length of the annular air outlet groove (7-3) is between one fifth and one half of the radius length of the blade.

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