CN110132030A - A Condensation Mixing Coupling Heating Depth Demisting Method - Google Patents

Abstract

The invention discloses a condensation mixing coupled heating depth defogging method, comprising the following steps: (1) passing hot and humid air into the hot channel of the condensation heat exchange device to exchange heat with dry and cold air entering the cold channel of the condensation heat exchange device , the temperature of the hot and humid air decreases and the moisture content decreases, condensation occurs, the condensed water is collected and processed, the temperature of the dry and cold air rises, and the moisture content remains unchanged; (2) The hot and humid air after heat exchange through the condensation heat exchange device The air is mixed in the hot and cold air mixer, and the mixed air formed is unsaturated air; (3) The mixed air is heated by the mixed air heater to make the state point of the mixed air further follow the principle saturation curve, to achieve the purpose of deep fog removal, and mix after heating Gas may be vented to atmosphere. The invention can recover the moisture in the hot and humid air while achieving the purpose of deep defogging.

Description

A Condensation Mixing Coupling Heating Depth Demisting Method

technical field

The invention belongs to the technical field of water collection and mist elimination, and in particular relates to a condensation mixing coupled heating depth mist elimination method.

Background technique

With the advancement of industrialization, the national industrial water consumption has increased significantly, accounting for about 25% of the total water consumption of the whole society, of which 80% is used for industrial cooling. Industrial cooling water consumption is large, recycling is low, and water loss is high. Research on industrial cooling savings Water, reconstruct the industrial cooling water-saving process, optimize the cooling water system, research and develop key cooling water-saving equipment, significantly reduce cooling water loss, and greatly improve industrial water efficiency, which is of great significance for significantly reducing industrial water consumption and effectively suppressing industrial plume pollution .

In the chemical industry, metallurgy and other fields, a large amount of hot and humid air is directly discharged from the cooling tower or chimney. The discharged hot and humid air is easy to condense to form a plume, which affects the visibility of surrounding residential areas and traffic roads, causing environmental pollution, and also makes the roads around the factory wet and slippery, affecting the work of maintenance personnel. my country is one of the countries with the poorest water resources in the world, and the recovery of moisture in hot and humid air with a high humidity content is also in line with the requirements of the national energy-saving and consumption-reducing policy.

Therefore, how to recover water from cooling towers or chimneys that discharge a large amount of steam while achieving deep fog removal is an urgent problem to be solved at present.

The patent of invention with the notification number CN108800983A discloses a water-saving type mist-elimination cooling tower. This water-saving anti-fog cooling tower includes a cooling tower body, a sump, a cooling coil, a first air inlet, a water spraying filler layer, a water distribution pipeline, a first spray head and an exhaust fan, and the upper part of the water distribution pipeline. The heat exchange and anti-fog mechanism is fixed, and the second spray head is arranged at the bottom of the heat exchange and anti-mist mechanism; The water pipeline is connected, and the second water outlet is connected to the top of the heat exchange and demist mechanism; a second air inlet is arranged between the heat exchange and demist mechanism and the water distribution pipeline. A water-saving anti-fog cooling tower of the present invention cooperates with the second air inlet through the heat exchange and anti-fog mechanism to condense and drop the water vapor, effectively eliminating the evaporation loss of spray cooling water, the overall structure is simple, and the manufacturing cost is low. Economical and practical.

In this technical solution, the heat exchange and defogging mechanism includes a left fixed plate, a right fixed plate, a plurality of longitudinal hollow continuous bending plates arranged between the left fixed plate and the right fixed plate, and a plurality of longitudinal hollow continuous bending plates arranged between the left fixed plate and the right fixed plate. Two first water delivery pipes at the top of the right fixed plate and three second water delivery pipes arranged at the bottom of the left fixed plate and the right fixed plate. The bottom of the first water delivery pipe communicates with the top of each longitudinal hollow continuous bent plate in turn, and the top of the second water delivery pipe communicates with the bottom of each longitudinal hollow continuous bent plate in turn. The top of the right fixing plate is a hollow structure, and the top of the right fixing plate communicates with the second water outlet of the circulating water pipe. The longitudinal hollow continuous bending plate structure of the heat exchange and defogging mechanism is beneficial to increase the condensation time of water vapor, and effectively prevents water vapor or condensed water droplets from being carried out of the cooling tower by the fan.

However, the above-mentioned technical scheme still has the defect that the fog elimination is not thorough enough, and it is impossible to realize deep fog elimination.

The invention patent of notification number CN102901397A discloses a wet cooling tower mist elimination and water collection device. The upper water pipe is connected to the water collection chamber, the water collection chamber is connected to one end of the condensate water pipe, the other end of the condensate water pipe is connected to the upper part of the return chamber, the lower part of the return chamber is reconnected to one end of the condensate water pipe, and the other end of the condensate water pipe returns The water distribution chamber connected to the water collection and distribution chamber forms a closed-circuit circulation structure. The lower end of the water distribution chamber is connected to the spray pipe; the condensation water pipe is attached to the concave-convex heat sink; A water-blocking sheet is set on the inner convex surface of the sheet; the upper end of the upper water pipe is connected to the integrated water chamber, and the lower end is connected to the pressurized water pump, and then connected to the mixing water tank to form a fog-eliminating and water-collecting device. The invention condenses saturated hot and humid mist into water, avoids evaporation of water, saves water resources, and avoids environmental pollution.

However, the above-mentioned technical scheme still has the defect that the fog elimination is not thorough enough, and it is impossible to realize deep fog elimination.

The invention patent with the notification number CN108895857A discloses a fog-eliminating and water-saving cooling tower and a water-saving method thereof. The cooling tower includes a tower body, an electrostatic defogging device and a water collection tank. The electrostatic defogging device includes a defogging unit and a supporting power supply. The defogging unit is installed on the top outlet of the tower body, and the water collection tank is installed under the defogging unit. When the exhaust gas A in the tower inside the tower merges with the cold air B outside the tower at the top outlet, it is cooled and reaches the supersaturated state of water vapor to form mist. The electrostatic demisting device is used to capture the mist formed by the exhaust gas, so that the mist is collected in the electrostatic demister. The anode of the mist removal unit in the mist device accumulates liquid water flowing downward, and the liquid water is collected in the sump for recycling, so as to achieve the purpose of saving water in the cooling tower. The invention uses the electrostatic defogging device to save water in the cooling tower, has good water saving effect and less environmental pollution.

However, the above-mentioned technical solution also has the defect that the fog elimination is not thorough enough, and it is impossible to realize deep fog elimination.

Contents of the invention

The purpose of the present invention is to provide a method for deep defogging by condensation mixing coupled with heating, which can recover the moisture in hot and humid air and achieve the purpose of deep defogging at the same time.

In order to solve the problems of the technologies described above, the present invention adopts the following technical solutions:

A condensation mixing coupled heating depth defogging method, comprising the following steps:

(1) The hot and humid air is passed into the hot channel of the condensation heat exchange device to exchange heat with the dry and cold air entering the cold channel of the condensation heat exchange device. The temperature of the hot and humid air decreases and the moisture content decreases, condensation occurs, and the condensed water is collected Treatment, the temperature of dry and cold air rises, and the moisture content remains unchanged;

(2) Mix hot and humid air with dry and cold air in the hot and cold air mixer after heat exchange through the condensing heat exchange device, and the mixed air formed is unsaturated air;

(3) The mixed air is heated by the mixed air heater so that the state point of the mixed air further reaches the principle saturation curve to achieve the purpose of deep fog removal. After heating, the mixed gas can be discharged into the atmosphere.

The condensation heat exchange device in the step (1) is a partition-type condensation heat-exchange device, and the partition-type condensation heat exchange device includes two sets of opposite labyrinth-type partition wall heat exchangers and a V-shaped dry and cold air confluence area in the middle; The labyrinth partition wall heat exchanger is composed of labyrinth cold aisles and labyrinth hot aisles arranged alternately. The gas flow direction in the labyrinth cold aisles is set horizontally, and the gas flow direction in the labyrinth hot aisles is set vertically; the dry and cold air is horizontally arranged. Entering the labyrinth cold channel of the condensing heat exchange device, hot and humid air enters the labyrinth hot channel vertically from bottom to top, and the hot and cold air exchanges heat in the labyrinth partition wall heat exchanger. After heat exchange, the dry and cold air enters the dry and cold air to meet area and move upwards.

The labyrinth-shaped cold channel and the labyrinth-shaped hot channel are collectively called the heat exchange channel. The heat exchange channel is composed of two opposite heat exchange plates. The heat exchange plates are in a zigzag shape; The labyrinth-type channel forms periodic expansion and contraction.

The peak height on the heat exchange plate is the no stagnation height.

A sealing plate is arranged around the heat exchange plate to seal the heat exchange channel; a plurality of matching sealing protrusions and sealing grooves are respectively provided on the sealing plates of every two opposite heat exchange plates.

The middle part of each group of two heat exchange plates constituting the heat exchange channel is arranged with a raised butt joint for butt joint.

The surface of each heat exchange plate located on one side of the labyrinth heat channel is coated with a hydrophilic coating.

Each group of two heat exchange plates constituting the heat exchange channel is arranged in a mirror image corresponding form.

Each group of two heat exchange plates constituting a labyrinth-shaped cold aisle is arranged in a parallel corresponding manner, and each group of two heat exchange plates constituting a labyrinth-shaped hot aisle is arranged in a mirror-image correspondence manner.

The mixed air heater in the step (3) is located in the hot and cold air mixer.

Beneficial effects of the present invention:

1. The present invention realizes the heat exchange between hot and humid air and dry and cold air by using the condensation heat exchange device, the hot and humid air condenses to achieve the water collection effect, and the temperature of the dry and cold air rises. And by mixing the hot and cold air after heat exchange, the state point of the mixed air is in the unsaturated area to achieve preliminary fog removal, and by using the heater to heat the mixed air, the state point of the mixed air is further away from the saturation curve, reaching the depth Anti-fog purpose.

The invention uses cold air as the cooling medium with low cost, and ensures high reliability of defogging through simple heating, and the structure of the whole process is simple and easy to realize. The invention can be applied to cooling towers or chimneys that discharge steam in various fields, and can achieve the purpose of deep fog removal while realizing water saving, and the environmental protection effect is remarkable.

2. The condensing heat exchange device in the present invention uses a partitioned condensing heat exchange device. The partitioned condensing heat exchange device includes two sets of opposite labyrinth-type partitioned wall heat exchangers and a V-shaped dry and cold air confluence area in the middle part, which can simultaneously realize Improve the heat exchange capacity of hot and cold air, solve the problem of condensed water collection in hot and humid air, and prevent the short circuit of cold air flow.

The labyrinth cold channel in the partition wall condensation heat exchange device is a labyrinth channel that expands and contracts periodically, and the flow area changes continuously during the horizontal flow of cold air in the labyrinth cold channel, which can increase the disturbance of the cold air and increase the heat transfer coefficient at the same time It plays the role of balancing resistance, promotes the resistance balance between hot and humid airflow and cold airflow, and prevents the short circuit phenomenon of cold air flow, and the labyrinth channel will also prolong the air flow and increase the heat exchange time.

The heat exchange heat plates forming the hot and cold passages in the partition-type condensation heat exchange device are labyrinth-shaped, and their peak heights are no stagnation heights, which will not cause cold air to stagnate while enhancing air disturbance.

Each pair of heat exchange plates constituting the heat exchange channel in the partitioned wall condensation heat exchange device is butted by the opposite raised butt joints arranged on the heat exchange plates to support the heat exchange plates.

In the partition-type condensation heat exchange device, the surface of the heat exchange plate located on both sides of the heat channel is coated with a hydrophilic material coating, which is beneficial to the collection of condensed water from the hot and humid air.

The partition wall condensing heat exchange device has a V-shaped dry and cold air confluence area in the middle part, which can make the cold air passing through the labyrinth partition wall heat exchanger have an oblique upward velocity, which is convenient for the mixing of cold and hot air after heat exchange.

3. In the present invention, the mixed air heater is located in the hot and cold air mixer, which can directly heat the mixed air, so that the state point of the mixed air is further away from the saturation curve, so as to achieve the purpose of deep fog removal.

Description of drawings

Accompanying drawing 1 is process flow diagram of the present invention;

Accompanying drawing 2 is the structural representation of intermediate wall type condensation heat exchange device of the present invention;

Accompanying drawing 3 is a single heat exchange plate structure diagram in Fig. 2;

Accompanying drawing 4 is a structural diagram of the heat exchange channel in Fig. 2;

Accompanying drawing 5 is one of the schematic diagrams corresponding to the form of the heat exchange plate in the heat exchange channel in Figure 2;

Accompanying drawing 6 is the second schematic diagram of the corresponding form of the heat exchange plate in the heat exchange channel in Figure 2;

Accompanying drawing 7 is the air psychrometric chart of the deep defogging process of the present invention;

Accompanying drawing 8 is the concrete implementation schematic diagram of the present invention in cooling tower.

The reference signs of the components in the figure: 1-cooling tower; 2-filling part; 3-spray device; 4-water eliminator; 5-labyrinth partition wall heat exchanger; 6-V-shaped dry and cold air confluence area; 7-heating device; 8-air cylinder; 9-fan; 10-mixing section air chamber; 11-heat exchange plate; 501-cold aisle; 502-hot aisle; 503-raised joint; -Seal the groove.

Detailed ways

Specific embodiments of the present invention will be described in detail below in conjunction with the accompanying drawings. It should be understood that the specific embodiments described here are only used to illustrate and explain the present invention, and are not intended to limit the present invention.

As shown in Figure 1, a condensation mixing coupled heating depth defogging method in this embodiment includes the following steps:

(1) The hot and humid air is passed into the hot channel of the condensation heat exchange device to exchange heat with the dry and cold air entering the cold channel of the condensation heat exchange device. The temperature of the hot and humid air decreases and the moisture content decreases, condensation occurs, and the condensed water is collected Treatment, the temperature of dry and cold air rises, and the moisture content remains unchanged;

(2) Mix hot and humid air with dry and cold air in the hot and cold air mixer after heat exchange through the condensing heat exchange device, and the mixed air formed is unsaturated air;

(3) The mixed air is heated by the mixed air heater so that the state point of the mixed air further reaches the principle saturation curve to achieve the purpose of deep fog removal. After heating, the mixed gas can be discharged into the atmosphere.

The condensation heat exchange device in the step (1) is a partition wall condensation heat exchange device, as shown in Figure 2 to Figure 5, the partition wall condensation heat exchange device includes two sets of opposite labyrinth type partition wall heat exchangers 5 and the middle Part of the V-shaped dry and cold air confluence area 6.

The labyrinth partition wall heat exchanger is composed of labyrinth cold aisles 501 and labyrinth hot aisles 502 arranged alternately in sequence, the gas flow direction in the labyrinth cold aisles 501 is set horizontally, and the gas flow direction in the labyrinth hot aisles 502 is set vertically The dry and cold air enters the labyrinth cold channel 501 horizontally from both sides, and the hot and humid air enters the labyrinth hot channel 502 vertically from bottom to top. The hot and cold air exchanges heat in the labyrinth partition wall heat exchanger 5. The air enters the dry and cold air confluence zone 6. Due to the setting of the V-shaped dry and cold air confluence area 6, the dry and cold air after heat exchange can have an oblique upward partial velocity, which is beneficial to the mixing of cold and hot air after heat exchange.

The above-mentioned labyrinth cold channel 501 and labyrinth hot channel 502 are collectively referred to as heat exchange channels, and the heat exchange channels are composed of two opposite heat exchange plates 11, and the heat exchange plates 11 are in the shape of a labyrinth; the peak of each two heat exchange plates 11 The valleys form a labyrinth channel by contrast, and the labyrinth channel forms periodic expansion and contraction.

In this embodiment, the two heat exchange plates 11 forming the heat exchange channel are combined in a mirror image form, as shown in FIG. 5 . It can also adopt the form shown in Figure 6, each group of two heat exchange plates forming the labyrinth-shaped cold channel 501 is arranged in a parallel corresponding form, and each group of two heat exchange plates forming the labyrinth-shaped hot channel 502 is arranged in a mirror image corresponding form .

There are sealing plates around the heat exchange plate 11 to seal the hot and cold passages. The labyrinth cold passage 501 is sealed and closed on its upper and lower sides, and the labyrinth hot passage 502 is sealed and closed on its left and right sides, and every two opposite heat exchange plates are sealed. Several matching sealing protrusions 504 and sealing grooves 505 are provided on the plate for sealing.

The middle part of each group of two heat exchange plates constituting the heat exchange channel is arranged with a raised butt joint 503 , and the joints 503 of the two heat exchange plates 11 are bonded to support the channel and prevent the channel from collapsing.

The peak height of the heat exchange plate 11 is no stagnation height, which will not cause the cold air to stagnate when it plays the role of enhancing the air disturbance, and the material of the heat exchange plate 11 is made of light material with high thermal conductivity, which is beneficial to the exchange of hot and cold air. hot. At the same time, the surface of the heat exchange plate 11 located on both sides of the labyrinth-shaped heat channel is coated with a hydrophilic material coating, which is beneficial to trapping condensed water from the hot and humid air.

During the horizontal flow of cold air in the labyrinth-shaped cold channel 501, the constant change of the flow area can increase the disturbance of the cold air, increase the heat transfer coefficient, and at the same time play a role in balancing resistance, promote the resistance balance between the hot and humid airflow and the cold airflow, and prevent the flow of cold air from short-circuiting The occurrence of the passage, and the passage is labyrinth will also prolong the air flow and increase the heat exchange time.

In the step (3), the mixed air heater is located in the hot and cold air mixer, which can directly heat the mixed air, so that the state point of the mixed air is further away from the saturation curve, so as to achieve the purpose of deep fog removal

The present invention realizes the water collection and deep condensation of hot and humid air by coupling the condensation heat exchange mixing process A and the heating process B together in series. In the condensation heat exchange mixing process A, the condensation temperature and moisture content of the hot and humid air decrease, and then And by mixing with the cold air after heat exchange, the temperature and moisture content of the mixed air are reduced to reach the unsaturated area. At this time, the mixed air can basically achieve the purpose of defogging, and then the mixed air is heated by the heating device to make the mixed air state The point is further away from the saturation curve, and the purpose of deep fog removal is achieved.

The working principle of the present invention will be further described below in conjunction with the air psychrometric chart, and accompanying drawing 7 is the air psychrometric chart of the deep fog removal process of the present invention. If the hot and humid air at the 3-state point is directly discharged into the external atmosphere at the 7-state point to mix, the line segment of the mixing process is 3-7, and the line segment 3-7 will pass through the supersaturated region to produce plume fog, which will be at the 3-state point The hot and humid air enters the partition wall condensing device to exchange heat with the cold outside air at state point 7. The temperature and moisture content of the hot and humid air will decrease, and its state point will drop to state point 4 along the saturation curve. After heat exchange, the dry and cold air will Then from the state point 7, it is heated along the line segment 7-8 to reach the state point 8. After the heat exchange, the dry and cold air 8 and the hot and humid air 4 will be mixed in the mixer along the line segment 4-7. The state point of the mixed air is 5, and the mixing The air is already in an unsaturated state, and the mixing line segment 5-7 between it and the outside atmosphere will basically not pass through the supersaturated zone. However, in order to achieve higher reliability of defogging, the mixed air at state point 5 is heated by a heating device. Heating, so that the mixed air is isohumidally heated along the line segment 5-6 until the state point 6 is further away from the saturation curve. At this time, when it is discharged into the external environment, the mixed line segment with the external atmosphere becomes line segment 6-7, line segment 6 -7 will not pass through the supersaturated region and the slope is smaller, so its reliability of defogging is higher.

The condensation mixing coupling heating depth defogging method of the present invention can be specifically applied in cooling towers during practical application, and can be shown as the implementation schematic diagram of the present invention in cooling tower specifically in Fig. 8, and its step of defogging is as follows:

(1) The high-temperature circulating water is sprayed by the water spraying device 3 onto the filling part 2 and the cold air enters from the air inlet at the lower part of the cooling tower 1 for heat and mass exchange, and the temperature of the circulating cooling water decreases; The temperature of the cold air entering under the cooling tower 1 rises, and the moisture content increases, forming basically saturated hot and humid air; when the hot and humid air passes through the water eliminator 4, the drifting water is captured, and then continues to rise and enter the labyrinth heat channel of the condensation heat exchange device Inside 502, it exchanges heat with the dry and cold air that enters the labyrinth cold channel 501 of the condensation heat exchange device from both sides of the cooling tower; the hot and humid air cools down and condenses in the hot channel, and the condensed water is captured by the hydrophilic coating on the surface of the hot channel , the temperature of dry and cold air rises;

(2) The cold air on both sides rises in the V-shaped dry and cold air confluence area 6 in the middle, and mixes with the hot air passing through the labyrinth-shaped hot passage 502 in the air chamber 10 of the mixing section, and the formed mixed air is unsaturated air;

(3) The mixed air is heated by the heater 7 arranged in the air chamber 10 of the mixing section, so that the state point of the mixed air further reaches the principle saturation curve to achieve the purpose of deep fog removal, and finally the heated mixed gas is discharged into the atmosphere by the fan 9 .

The above embodiments are only used to illustrate and not limit the technical solutions of the present invention. Although the present invention has been described in detail with reference to the above embodiments, those of ordinary skill in the art should understand that the present invention can still be modified or equivalently replaced without departing from it. Any modifications or partial replacements within the spirit and scope of the present invention shall fall within the scope of the claims of the present invention.

Claims (10)

1. A condensation mixing coupling heating depth defogging method is characterized in that comprising the following steps: (1) The hot and humid air is passed into the hot channel of the condensation heat exchange device to exchange heat with the dry and cold air entering the cold channel of the condensation heat exchange device. The temperature of the hot and humid air decreases and the moisture content decreases, condensation occurs, and the condensed water is collected Treatment, the temperature of dry and cold air rises, and the moisture content remains unchanged; (2) Mix hot and humid air with dry and cold air in the hot and cold air mixer after heat exchange through the condensing heat exchange device, and the mixed air formed is unsaturated air; (3) The mixed air is heated by the mixed air heater so that the state point of the mixed air further reaches the principle saturation curve to achieve the purpose of deep fog removal. After heating, the mixed gas can be discharged into the atmosphere. 2. A condensation mixing coupling heating depth defogging method according to claim 1, characterized in that: the condensation heat exchange device in the step (1) is a partition type condensation heat exchange device, and the partition wall type condensation heat exchange device It includes two sets of opposite labyrinth-shaped partition wall heat exchangers and a V-shaped dry and cold air confluence area in the middle; the labyrinth-type partition wall heat exchanger is composed of labyrinth-shaped cold channels and labyrinth-shaped hot channels arranged alternately in sequence, and the labyrinth-shaped cold channels The gas flow direction in the channel is set horizontally, and the gas flow direction in the labyrinth-shaped hot channel is set vertically; dry and cold air enters the labyrinth-shaped cold channel of the condensation heat exchange device horizontally, and humid and hot air enters the labyrinth-shaped hot channel vertically from bottom to top. The hot air exchanges heat in the labyrinth-type partition wall heat exchanger. After heat exchange, the dry and cold air enters the dry and cold air confluence area and flows upward. 3. A condensation mixing coupling heating depth defogging method according to claim 2, characterized in that: the labyrinth-shaped cold channel and the labyrinth-shaped hot channel are collectively referred to as heat exchange channels, and the heat exchange channels are composed of two opposite heat exchange channels. The heat exchange plate is zigzag; the peaks and valleys of every two heat exchange plates are compared to form a labyrinth channel, and the labyrinth channel forms periodic expansion and contraction. 4 . The method according to claim 3 , wherein the height of the wave peak on the heat exchange plate is the height of no stagnation. 5. A condensation mixing coupling heating depth defogging method according to claim 3, characterized in that: a sealing plate is provided around the heat exchange plate to seal the heat exchange channel; Several matching sealing protrusions and sealing grooves are respectively provided. 6 . The method according to claim 5 , characterized in that: the middle part of each group of two heat exchange plates constituting the heat exchange channel is arranged with a raised butt joint for butt joint. 7 . 7. The method of condensation mixing coupling heating for deep defogging according to claim 3, characterized in that: each heat exchange plate is coated with a hydrophilic coating on the surface on one side of the labyrinth-shaped heat channel. 8 . The method according to claim 3 , characterized in that: each group of two heat exchange plates constituting a heat exchange channel is arranged in a mirror image corresponding form. 9 . 9. A condensation mixing coupling heating depth defogging method according to claim 3, characterized in that: each group of two heat exchange plates forming a labyrinth-shaped cold channel is arranged in a parallel corresponding form, and each group forms a labyrinth-shaped hot channel The two heat exchange plates are arranged in a mirror image corresponding form. 10. The method of condensation mixing coupling heating for deep defogging according to claim 1, characterized in that: the mixed air heater in the step (3) is located in the cold and hot air mixer.