A rotary coating dehumidification system

Abstract

The application discloses a rotary coating dehumidification system, which comprises a rotary coating dehumidifier in a cylindrical shape, and an adiabatic plate is arranged in the rotary coating dehumidifier along the axial direction of the rotary coating dehumidifier, and the adiabatic plate divides the rotary coating dehumidifier into a dehumidification zone and a regeneration zone. The air channels of the dehumidification zone and the regeneration zone each comprise a primary flow side and a secondary flow side, the two sides of the channels are distributed in an intersecting and spaced manner, the primary flow side is coated with different desiccants in sequence, and the secondary flow side is only used as a cooling air channel in the dehumidification zone. The direction from the air inlet to the air outlet of the primary flow side of the dehumidification zone and the regeneration zone is opposite, and the air outlet and the air inlet of the secondary flow side are distributed at the front end and the rear end of the upper edge of the dehumidification zone. The application has the beneficial effects that the dehumidification performance can be enhanced by using different desiccants to realize a graded adsorption-desorption process, the heat influence of the adsorption process can be effectively eliminated by using the cooling air of the secondary flow side of the dehumidification zone, and the adsorption heat, the residual heat of regeneration and the waste heat of the exhaust gas of regeneration can be recycled and utilized.

Description

Technical Field

[0001] This invention relates to the field of heating, ventilation and air conditioning equipment and air dehumidification technology, and particularly to a rotary coating dehumidification system. Background Technology

[0002] As an effective dehumidification technology driven by low-grade heat energy such as solar energy, geothermal energy, and industrial waste heat, solid adsorption dehumidification technology can perfectly combine energy conservation and emission reduction with the development and utilization of low-grade heat energy, and has a bright development prospect. Among the three types of solid dehumidifiers—rotary, fixed-bed, and coated—coated dehumidifiers have attracted much attention because they can simultaneously handle sensible and latent heat loads. Coated dehumidifiers are made by coating desiccant onto the wall of a traditional metal heat exchanger. The close contact between the thin desiccant layer and the heat exchanger wall ensures good heat and mass transfer capabilities. In addition, coated dehumidifiers can eliminate the influence of adsorption heat and regeneration residual heat during the adsorption process by introducing internal cooling fluid, thereby improving dehumidification capacity. However, compared with rotary dehumidifiers, which can achieve continuous dehumidification with a single bed, coated dehumidifiers require at least two beds to ensure continuous dehumidification, inevitably increasing the system size and complexity, which seriously restricts its application and promotion.

[0003] Employing a special structural design to manufacture a rotary dehumidifier with a coating system is an effective solution for achieving continuous dehumidification of a single bed. Currently, several rotary coating dehumidifiers with special structures have been reported. Based on their internal cooling methods, they can be mainly divided into two types: external cooling water pipe cooling and air-wall cooling. The external cooling water pipe cooling rotary coating dehumidifier is developed from the traditional shell-and-tube heat exchanger. The desiccant is coated inside the pipes, and during adsorption, the dehumidification zone rotates and is immersed in cooling water for real-time cooling of the desiccant layer. The air-wall cooling rotary coating dehumidifier divides the cylindrical dehumidifier into multiple small fan-shaped areas along its circular surface. The cooling air channel and the desiccant channel are alternated, with the inlets or outlets of the two channels distributed along the circular surface and circumference, respectively. During adsorption, cooling air is introduced into the cooling air channel of the dehumidification zone to cool the desiccant layer. Both of these rotary coating dehumidifiers can combine the advantages of both coating and rotary dehumidifiers, but their dehumidification performance is relatively low, and they do not consider the recovery and utilization of adsorption heat, regeneration residual heat, and regeneration exhaust waste heat. Summary of the Invention

[0004] To address the aforementioned issues, this invention proposes a rotary coating dehumidification system that enhances dehumidification performance through a staged adsorption-desorption process using different desiccants. Simultaneously, it effectively eliminates the thermal impact of the adsorption process by introducing cooling air for internal cooling, and recovers and utilizes adsorption heat, regeneration residual heat, and regeneration exhaust waste heat.

[0005] The technical solution of the present invention is as follows:

[0006] A rotary coating dehumidification system includes a rotary coating dehumidifier, which is cylindrical in shape and has an insulation plate fixed along its own axis inside. The insulation plate divides the rotary coating dehumidifier into a dehumidification zone and a regeneration zone. The air passages of both the dehumidification zone and the regeneration zone include a primary flow side and a secondary flow side. Different desiccants are sequentially coated inside the primary flow side of both the dehumidification zone and the regeneration zone. The air inlet to outlet of the primary flow side of the dehumidification zone and the regeneration zone are arranged in opposite directions. The air outlet and air inlet of the secondary flow side of the dehumidification zone are distributed at the front and rear ends of the upper edge of the dehumidification zone. A first fan is installed at the air inlet of the primary flow side of the dehumidification zone, and a second fan is installed at the air inlet of the secondary flow side of the dehumidification zone. The air outlet of the secondary flow side of the dehumidification zone is sequentially coupled to a first medium channel of a heat exchanger and a heat source before being connected to the air inlet of the primary flow side of the regeneration zone. The air outlet of the primary flow side of the regeneration zone is connected to a second medium channel of the heat exchanger.

[0007] In some embodiments, the primary flow side interiors of both the dehumidification zone and the regeneration zone are coated with at least two different desiccants in the same direction.

[0008] In some embodiments, the dehumidification zone and the regeneration zone are each equally divided into pre-stage and post-stage on the primary flow side. The two pre-stage stages are coated with a first desiccant, and the two post-stage stages are coated with a second desiccant. Preset relative humidity ranges A1 and A2 are defined, where the minimum value of A1 is greater than the maximum value of A2. Within relative humidity range A1, the moisture absorption capacity of the first desiccant is greater than that of the second desiccant; within relative humidity range A2, the moisture absorption capacity of the second desiccant is greater than that of the first desiccant. Simultaneously, the regeneration temperature of the second desiccant is higher than that of the first desiccant.

[0009] In some embodiments, an annular cover plate with a ring-shaped opening is provided outside the dehumidification zone. The cover plate is used to separate the secondary flow side air inlet and outlet of the dehumidification zone. The cover plate is a fixed component, and its position does not change when switching between the dehumidification zone and the regeneration zone of the rotary coating dehumidifier. The secondary flow side air outlet and air inlet are both annular openings, distributed at the front and rear ends of the upper edge of the dehumidification zone.

[0010] In some embodiments, a drive motor is mounted on the shaft of the rotary coating dehumidifier.

[0011] In some embodiments, the heat source is at least one of solar energy, waste heat from equipment, or electric heating.

[0012] The beneficial effects of this invention are as follows: By sequentially coating different desiccants in a rotary coating dehumidifier, a staged adsorption-desorption process is constructed using the complementary relationship between the moisture absorption capacity and the regeneration temperature, thereby enhancing dehumidification performance. Simultaneously, a second fan introduces cooling air into the secondary flow side of the dehumidification zone to cool the desiccant layer on the primary flow side, promptly eliminating adsorption heat and residual regeneration heat. The preheated air then passes through a heat exchanger to recover waste heat from the regeneration exhaust gas, and is further heated by a heat source before being used as regeneration air. Therefore, this system can enhance dehumidification performance using a staged adsorption-desorption process, effectively eliminate the heat impact of the adsorption process, and recover and utilize adsorption heat, residual regeneration heat, and waste heat from the regeneration exhaust gas. Attached Figure Description

[0013] Figure 1 This is a schematic diagram of the rotary coating dehumidification system disclosed in an embodiment of the present invention;

[0014] Figure 2 This is a schematic diagram of the rotary coating dehumidifier structure disclosed in an embodiment of the present invention;

[0015] Figure 3a A schematic diagram showing the equilibrium moisture absorption of the first and second desiccants on the primary flow side of the dehumidification zone under different relative humidities;

[0016] Figure 3b A schematic diagram showing the absolute humidity of the air at the first and second desiccant outlets on the primary flow side of the dehumidification zone;

[0017] Figure 3c A schematic diagram showing the equilibrium moisture absorption of the first and second desiccants on the primary flow side of the regeneration zone under different relative humidities;

[0018] Figure 3d A schematic diagram showing the absolute humidity of the air at the first and second desiccant outlets on the primary flow side of the regeneration zone;

[0019] Wherein: 1-Rotary coated dehumidifier, 2-Insulation board, 3-Dehumidification zone, 4-Regeneration zone, 5-Secondary flow side air inlet, 6-Secondary flow side air outlet, 7-First fan, 8-Second fan, 9-Heat exchanger, 10-Heat source, 11-Cover plate, 12-Drive motor, 13-Primary flow side channel, 14-Secondary flow side channel. Detailed Implementation

[0020] To make the objectives, technical solutions, and advantages of this invention clearer and more explicit, the content of this invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are only for explaining this invention and are not intended to limit it. Furthermore, it should be noted that, for ease of description, only the parts relevant to this invention are shown in the accompanying drawings, not all of them.

[0021] This embodiment proposes a rotary coating dehumidification system, such as Figure 1 , Figure 2 As shown, it includes a rotary coated dehumidifier 1, which is cylindrical in shape and has a base of thermally conductive metal material. It consists of two stages of the same thickness. The rotary coating dehumidifier 1 has an internal insulation plate 2 fixed along its own axis. The insulation plate 2 divides the rotary coating dehumidifier 1 into a dehumidification zone 3 and a regeneration zone 4. The air passages of the dehumidification zone 3 and the regeneration zone 4 each include a primary flow side 13 and a secondary flow side 14. The primary flow side of the dehumidification zone 3 and the regeneration zone 4 are coated with different desiccants in sequence. The air inlet and outlet of the primary flow side of the dehumidification zone 3 and the regeneration zone 4 are arranged in opposite directions. The air inlet 5 and the air outlet 6 of the secondary flow side of the dehumidification zone 3 are distributed at the rear end and the front end of the upper edge of the dehumidification zone 3. The air inlet of the primary flow side of the dehumidification zone 3 is equipped with a first fan 7, and the air inlet 5 of the secondary flow side of the dehumidification zone 3 is equipped with a second fan 8. The air outlet 6 of the secondary flow side of the dehumidification zone 3 is connected to the first medium channel of the heat exchanger 9 and the heat source 10 in sequence, and then connected to the air inlet of the primary flow side of the regeneration zone 4. The air outlet of the primary flow side of the regeneration zone 4 is connected to the second medium channel of the heat exchanger 9. It should be noted that the rotary coated dehumidifier 1 described in this invention uses the air-wall cooling principle, i.e., it has a structure with a primary flow side 13 and a secondary flow side 14. The primary flow side 13 of the dehumidification zone 3 is the dehumidification air passage, and the secondary flow side 14 of the dehumidification zone 3 is the cooling air passage. The primary flow side 13 of the regeneration zone 4 is the regeneration air passage, and the secondary flow side 14 of the regeneration zone 4 remains idle. In subsequent operation control, simply switching the positions of the dehumidification zone 3 and the regeneration zone 4 will allow the regeneration zone 4 to become the dehumidification zone 3, thereby correspondingly changing the dehumidification zone 3 into the regeneration zone 4.

[0022] In this embodiment, the rotary coated dehumidifier 1 is divided into a dehumidification zone 3 and a regeneration zone 4 by an insulation plate 2. A first fan 7 introduces processed air into the primary flow side of the dehumidification zone 3, while a second fan 8 introduces cooling air into the secondary flow side. The cooling air cools the desiccant layer on the primary flow side of the dehumidification zone 3 while simultaneously recovering adsorption heat and residual regeneration heat. The preheated air then passes through a heat exchanger 9 to recover residual regeneration exhaust heat, and is further heated by a heat source 10 before being sent to the primary flow side of the regeneration zone 4 as regeneration air. Finally, the regeneration exhaust flows through the heat exchanger 9, where residual heat is recovered before being discharged outdoors. Therefore, this system can effectively eliminate the thermal impact of the adsorption process while simultaneously recovering and utilizing adsorption heat, residual regeneration heat, and residual regeneration exhaust heat.

[0023] Both the dehumidification zone 3 and the regeneration zone 4 have at least two different desiccants coated sequentially in the same direction on the primary flow side. Taking two desiccants as an example, the first desiccant, which has a stronger moisture absorption capacity under high humidity conditions, is used as the pre-stage (upstream of the treated air) in dehumidification zone 3, while the second desiccant, which has a stronger moisture absorption capacity in low humidity conditions, is used as the post-stage (downstream of the treated air) in dehumidification zone 3, which is beneficial for enhancing moisture absorption capacity. When the second desiccant, which requires a higher regeneration temperature, is used as the post-stage (upstream of the regeneration air) in regeneration zone 4, while the first desiccant, which requires a lower regeneration temperature, is used as the pre-stage (downstream of the regeneration air) in regeneration zone 4, the first desiccant can continue to desorb and regenerate using the lower-temperature regeneration exhaust gas upstream, achieving energy cascade utilization. The combination of desiccants with complementary moisture absorption capacity and regeneration temperature covers all types of desiccant materials and is not specifically limited here. In addition, the above complementary relationship does not only exist between two desiccants, but may be a combination of more than two desiccants. Therefore, the rotary coated dehumidifier 1 can have more than or equal to two stages. Through the complementary relationship of the moisture absorption capacity of the desiccants in the staged adsorption process, deep dehumidification of humid air can also be achieved.

[0024] Specifically, the primary flow sides of dehumidification zone 3 and regeneration zone 4 are equally divided into pre-stage and post-stage. The two pre-stage stages are coated with a first desiccant, and the two post-stage stages are coated with a second desiccant. Preset relative humidity ranges A1 and A2 are defined, with the minimum value of A1 greater than the maximum value of A2. Within relative humidity range A1, the moisture absorption capacity of the first desiccant is greater than that of the second desiccant; within relative humidity range A2, the moisture absorption capacity of the second desiccant is greater than that of the first desiccant. Simultaneously, the regeneration temperature of the second desiccant is higher than that of the first desiccant. Thus, dehumidification performance is enhanced through a staged adsorption-desorption process.

[0025] Reference Figures 3a-3d The basic principle of the staged adsorption-desorption process can be illustrated by examples of S-shaped (Ⅰ) and linear (Ⅱ) adsorption isotherms of desiccants: During the adsorption process, the inlet air corresponding to φ3 flows through the primary flow side of dehumidification zone 3, and the humidity gradually decreases, reaching φ1 at the outlet. If the first desiccant is used for the φ3→φ2 process, and the second desiccant is used for the φ2→φ1 process, then the total equilibrium moisture absorption capacity of the desiccant in the φ3→φ1 process will change along the dotted line path in the figure, which is higher than the equilibrium moisture absorption capacity of a single desiccant (e.g., ...). Figure 3a (As shown). Figure 3b The changes in air humidity at the primary flow side and the outlets of the first and second desiccants in the dehumidification zone 3 during the adsorption process were qualitatively represented. Because the second desiccant compensates for the insufficient moisture absorption capacity of the first desiccant within the φ1–φ2 humidity range, the humid air from upstream can be further dehumidified even under low humidity conditions, thus improving the dehumidification capacity. During the desorption process, the two desiccants at φ… ’ 3. Under the corresponding relative humidity conditions, they have the same equilibrium moisture absorption capacity W.’ 3. If the desorption amounts of the two desiccants are equal, that is, the equilibrium moisture absorption amounts both start from W... ’ 3 dropped to W ’ 1. The corresponding relative humidity at this time is φ ’ 1 and φ ’ 2 and φ ’ 1 < φ ’ 2 (e.g.) Figure 3c (As shown), this indicates that the first desiccant has a lower regeneration temperature. The second desiccant is placed upstream of the regeneration air, while the first desiccant is placed downstream. If the relative humidity of the regeneration air is φ... ’ 1. The changes in air humidity at the first and second desiccant outlets on the primary flow side of regeneration zone 4 during desorption can be qualitatively expressed as follows: Figure 3d Assuming the second desiccant reaches desorption equilibrium at time t'1, the humidity of the air entering the first desiccant inlet reaches φ. ’ 1. Due to φ ’ 1 < φ ’ 2. The desorption capacity of the first desiccant may even be higher than that of the second desiccant. When regeneration ends at time t'1, compared to the second desiccant alone, the downstream first desiccant can directly utilize the lower-temperature regeneration exhaust gas from the upstream, achieving energy cascade utilization. The resulting benefit is the desorption capacity of the first desiccant. It should be emphasized that the above is only an example and does not limit the specific type of desiccant, nor is the shape of the desiccant adsorption isotherm limited to "S" shape or linear. Any two or more desiccants whose moisture absorption capacity and regeneration temperature are complementary can construct a staged adsorption-desorption process.

[0026] During the operation of the rotary coated dehumidifier 1, in the dehumidification zone 3, the treated air first enters the primary flow side pre-stage of the dehumidification zone 3 and is first adsorbed and dehumidified by the first desiccant, which has a strong moisture absorption capacity under high humidity conditions. Then it flows into the primary flow side post-stage of the dehumidification zone 3 and is further adsorbed and dehumidified by the desiccant II, which has a strong moisture absorption capacity under low humidity conditions, thereby reducing the humidity. The adsorption process is carried out in stages. At the same time, ambient air or indoor low-temperature return air is introduced through the secondary flow side air inlet 5 of the dehumidification zone 3 to cool the desiccant layer on the primary flow side of the dehumidification zone 3, eliminating adsorption heat and regeneration residual heat. In the regeneration zone 4, the regeneration air first enters the primary flow side post-stage of the regeneration zone 4 to desorb the second desiccant, which has a higher regeneration temperature requirement, and then flows into the primary flow side pre-stage of the regeneration zone 4 to continue to desorb the first desiccant, which has a lower regeneration temperature requirement. The desorption process is carried out in stages.

[0027] The dehumidification zone 3 is equipped with an annular cover plate 11 with a ring-shaped opening. The cover plate 11 separates the secondary flow side air inlet 5 and air outlet 6 of the dehumidification zone 3. The annular cover plate 11 is a fixed component, and its position does not change when switching between the dehumidification zone 3 and the regeneration zone 4 of the rotary coating dehumidifier. Both the secondary flow side air inlet 5 and air outlet 6 of the dehumidification zone 3 are annular openings, located at the rear and front ends of the upper edge of the dehumidification zone. The air inlet 5 is connected to the second fan 8 through a pipe, and the air outlet 6 is connected to the heat exchanger 9 through a pipe.

[0028] The rotary coating dehumidifier 1 is equipped with a drive motor 12 on its shaft, and the driving rotation method can be determined according to specific conditions. When the dehumidification zone 3 is saturated, the drive motor 12 drives the rotary coating dehumidifier 1 to rotate, switching between the dehumidification zone 3 and the regeneration zone 4 to ensure continuous dehumidification. Since the rotary coating dehumidifier 1 rotates intermittently, the operating noise can be effectively reduced.

[0029] The heat source 10 can be at least one of solar energy, waste heat from equipment, or electric heating.

[0030] The above embodiments are merely illustrative of the technical concept and features of the present invention, and are intended to enable those skilled in the art to understand the content of the present invention and implement it accordingly. They should not be construed as limiting the scope of protection of the present invention. All equivalent changes or modifications made based on the essence of the content of the present invention should be covered within the scope of protection of the present invention.

Claims

1. A rotary coating dehumidification system, comprising a rotary coating dehumidifier, characterized in that, The rotary coated dehumidifier is cylindrical, with an internal insulation plate fixed along its own axis. The insulation plate divides the dehumidifier into a dehumidification zone and a regeneration zone. Both the dehumidification and regeneration zones have primary and secondary flow sides in their air passages. Different desiccants are sequentially coated on the primary flow sides of both zones, and the directions from the air inlet to the air outlet on the primary flow side of each zone are opposite. The air outlet and air inlet on the secondary flow side of the dehumidification zone are located at the front and rear ends of the upper edge of the zone. A first fan is installed at the primary flow side air inlet, and a second fan is installed at the secondary flow side air inlet. The air outlet on the secondary flow side of the dehumidification zone is sequentially connected to the first medium of the heat exchanger. The channel and heat source are coupled and connected to the primary flow side air inlet of the regeneration zone. The primary flow side air outlet of the regeneration zone is connected to the second medium channel of the heat exchanger. The primary flow side of the dehumidification zone and the regeneration zone are equally divided into front stage and rear stage. The two front stages are coated with a first desiccant, and the two rear stages are coated with a second desiccant. The relative humidity ranges A1 and A2 are preset, and the minimum value of A1 is greater than the maximum value of A2. In the relative humidity range A1, the moisture absorption of the first desiccant is greater than that of the second desiccant. In the relative humidity range A2, the moisture absorption of the second desiccant is greater than that of the first desiccant. At the same time, the regeneration temperature of the second desiccant is higher than that of the first desiccant.

2. The rotary coating dehumidification system as described in claim 1, characterized in that, Both the dehumidification zone and the regeneration zone have at least two different desiccants coated sequentially in the same direction on the primary flow side.

3. The rotary coating dehumidification system as described in claim 1, characterized in that, The dehumidification zone is provided with an annular cover plate with two annular openings. The cover plate is used to separate the air inlet and air outlet on the secondary flow side of the dehumidification zone. The cover plate is a fixed component and its position does not change with the switching between the dehumidification zone and the regeneration zone of the rotary coating dehumidifier. The air outlet and air inlet on the secondary flow side are both annular openings and are distributed at the front and rear ends of the upper edge of the dehumidification zone.

4. The rotary coating dehumidification system as described in claim 1, characterized in that, The rotary coating dehumidifier has a drive motor mounted on its shaft.

5. The rotary coating dehumidification system as described in claim 1, characterized in that, The heat source is at least one of solar energy, waste heat from equipment, or electric heating.

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