A phase change based dehumidification wheel device and its application method

Abstract

The present invention discloses a phase change-based dehumidification wheel device and an application method thereof. The device comprises a dehumidification wheel, a dehumidification wheel frame and a purge air cooling device. The dehumidification wheel is composed of a matrix layer with a phase change material added and an adsorbent layer coated on the surface of the matrix layer. The adsorbent layer is used to adsorb and process water vapor in the air. The phase change material stores the adsorption heat generated in the adsorption process in the phase change latent heat. The dehumidification wheel frame divides the dehumidification wheel into a dehumidification zone, a regeneration zone and a purge zone. The purge air cooling device controls the cooling capacity of the cooling device according to the air temperature at the purge air outlet. The present invention accurately presets the phase change temperature, phase change latent heat and addition amount of the phase change material, and designs a suitable rotation speed according to the angles of the dehumidification zone, the regeneration zone and the purge zone. The dehumidification adsorption process is maintained as an isothermal process at the phase change temperature by the device, ensuring that the temperature of the dehumidifier does not rise due to the adsorption heat released during the adsorption process, thereby improving the adsorption capacity and dehumidification effect of the dehumidification wheel.

Description

Technical Field

[0001] The present invention belongs to the field of HVAC equipment, and in particular relates to a phase change-based dehumidification wheel device and an application method thereof. Background Art

[0002] Conventional dehumidification wheels are divided into a dehumidification zone and a regeneration zone, and are composed of a matrix layer and an adsorbent coated on the matrix layer: during dehumidification, air flows through the dehumidification zone, and water vapor in the air is adsorbed by the wheel, reducing the humidity of the air; during regeneration, the saturated wheel rotates into the regeneration zone and is heated and regenerated by hot air. After regeneration, the dehumidification wheel re-enters the dehumidification zone for dehumidification as it rotates. The matrix layer is used to provide a supporting structure, and the adsorbent layer is used to adsorb water vapor in the air to achieve dehumidification.

[0003] When the adsorbent layer uses solid adsorption, the process of gaseous water in the air turning into liquid water will occur, thereby releasing heat, namely adsorption heat, which makes the solid adsorption dehumidification process a nearly isenthalpic process. The adsorption heat generated by the adsorption process will heat the dehumidification wheel, causing the temperature of the dehumidification wheel and the dehumidified air to increase. The equilibrium adsorption capacity of the adsorbent is negatively correlated with the temperature, that is, the higher the temperature, the lower the equilibrium adsorption capacity. Therefore, under the influence of adsorption heat, the decrease in equilibrium adsorption capacity caused by the increase in adsorbent temperature will cause the dehumidification wheel adsorption capacity to decrease, thereby reducing the dehumidification capacity of the dehumidification wheel. Summary of the invention

[0004] The object of the present invention is to provide a phase change based dehumidification wheel device and its application method, which enables the dehumidification wheel to have a higher equilibrium adsorption capacity and dehumidification capacity, so that the efficiency of the regeneration process is guaranteed.

[0005] In order to achieve the above technical objectives, the present invention provides the following technical solutions:

[0006] A phase change-based dehumidification wheel device comprises a dehumidification wheel, a dehumidification wheel frame, a purge air cooling device and a temperature sensor; the dehumidification wheel is arranged in the dehumidification wheel frame, and the dehumidification wheel frame is provided with a partition bar, and the partition bar divides the two sides of the dehumidification wheel into a dehumidification zone, a regeneration zone and a purge zone; the dehumidification wheel matrix layer is coated with an adsorbent layer and a phase change material matrix layer; the dehumidification wheel purge air inlet is provided with a purge air cooling device.

[0007] Preferably, a temperature sensor is provided at the outlet of the purge zone of the dehumidification wheel, the temperature sensor is electrically connected to the control system, and the set temperature of the temperature sensor is the inlet temperature of the processed air.

[0008] Preferably, the purge air cooling device is arranged before the purge air inlet of the dehumidification wheel for cooling the purge air; the phase change temperature of the phase change material should be selected to be 1°C higher than the inlet temperature of the processed air during operation.

[0009] Preferably, the amount of phase change material added in the phase change material matrix layer does not exceed 30% of the total mass of the dehumidification wheel.

[0010] Preferably, the phase change latent heat and the amount of phase change material added in the phase change material should satisfy the following calculation formula:

[0011]

[0012] Where: Q L is the phase change latent heat of the phase change material (unit: kJ / kg), q st is the adsorption heat of the adsorbent material (in kJ / kg), W(T l ,p v ) is the phase transition temperature T l , process air inlet water vapor partial pressure p v The corresponding equilibrium adsorption capacity (unit: kg / kg) is as follows: m is the mass ratio of the adsorbent in the dehumidification wheel to the whole dehumidification wheel (should not exceed 50% of the total mass of the wheel), and f is the mass ratio of the phase change material in the dehumidification wheel body.

[0013] Preferably, the mass proportion f of the phase change material should not exceed 30%, and the mass proportion m of the adsorbent to the whole dehumidification wheel should not exceed 50%, so as to ensure the adsorption capacity and strength structure of the dehumidification wheel.

[0014] Preferably, the angle of the dehumidification zone in the dehumidification wheel is defined as the dehumidification zone angle α°, and the angle of the regeneration zone in the dehumidification wheel is defined as the regeneration zone angle β°; the dehumidification zone angle α° is greater than the regeneration zone angle β°, and the average adsorption rate and desorption rate of the adsorbent material from non-adsorption to adsorption saturation in the dehumidification zone angle α° and the regeneration zone angle β° are calculated according to the following formula:

[0015]

[0016] Where: r is the dehumidification wheel speed (unit: r / h), R ad and R de are the adsorption rate and desorption rate of the dehumidification wheel (in kg / (kg·s));

[0017] The operating speed of the dehumidification wheel should be determined by trial calculation so that the selected speed satisfies (360°-α-β)=5~10°.

[0018] The present invention also provides an application method of a phase change-based dehumidification wheel device, the steps of which are as follows:

[0019] S1: The air A to be treated enters the dehumidification zone of the dehumidification wheel after passing through the dehumidification wheel. The phase change material added to the matrix layer of the dehumidification wheel stores the adsorption heat generated by the adsorbent layer in the adsorption process in the phase change latent heat of the phase change material, thereby controlling the air temperature at the outlet of the treated air and the temperature of the dehumidification wheel at 26°C. At the same time, the adsorption heat stored in the phase change latent heat of the phase change material is stored in the purge zone and cooled by the surface cooler used by the purge air cooling device through cold air, ensuring that the adsorbent layer still has water vapor adsorption capacity when entering the dehumidification zone;

[0020] After dehumidification, it is divided into two routes, one is supply air B, accounting for 90% of the total processed air flow, and the other is purge air C, accounting for 10% of the total processed air flow;

[0021] S2: The purge air cooling device is controlled according to the real-time value collected by the temperature sensor: when the temperature of the temperature sensor is higher than the process air inlet temperature, the cooling capacity of the purge air cooling device should be increased or the cooling temperature should be lowered; when the temperature of the temperature sensor is lower than the process air inlet temperature, the cooling capacity of the purge air cooling device should be reduced or the cooling temperature should be increased.

[0022] The phase change material in the phase change material matrix layer used in the present invention is a special material that only changes energy without changing temperature during the heat absorption process, and has been widely used. When the phase change material is applied to the dehumidification wheel, the adsorption heat generated during the adsorption process can be stored in the phase change latent heat of the phase change material, thereby ensuring that the temperature of the dehumidification adsorption process remains unchanged. Therefore, in order to ensure a complete cycle and the appropriate selection and addition of the phase change material, the amount of phase change material added, the phase change temperature and the phase change latent heat need to be selected and designed.

[0023] Compared with conventional dehumidification wheels, the present invention has the following beneficial effects:

[0024] 1. The equilibrium adsorption capacity of the adsorbent layer decreases with increasing temperature, so the dehumidification wheel with added phase change material has a higher equilibrium adsorption capacity and dehumidification capacity.

[0025] 2. The amount of phase change material added and the latent heat of phase change used in this method just meet the requirement that the adsorption heat after adsorption is exactly equal to the latent heat of phase change. When entering the regeneration zone, too much regeneration heat is not wasted to supplement the latent heat of phase change, thereby ensuring the efficiency of the regeneration process.

[0026] In summary, the present invention adds phase change material in the matrix layer of the dehumidification wheel to ensure that the adsorption process is not an isothermal process, reduce the increase in adsorbent temperature and treated air temperature caused by the adsorption heat of the adsorption process, and thus improve the equilibrium adsorption capacity and dehumidification capacity of the adsorbent. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 A schematic diagram of the side view structure of a phase change-based dehumidification wheel proposed by the present invention;

[0028] Figure 2 This is a front view structural schematic diagram of a phase change-based dehumidification wheel proposed by the present invention;

[0029] Figure 3 This is a schematic diagram of the microchannel cross-sectional structure of a phase change-based dehumidification wheel proposed in the present invention.

[0030] The numbers in the figure are as follows:

[0031] 1. Dehumidification wheel; 2. Dehumidification wheel frame; 3. Purge air cooling device; 4. Temperature sensor; 1-1. Dehumidification zone; 1-2. Regeneration zone; 1-3. Purge zone; 5. Adsorbent layer; 6. Phase change material matrix layer. DETAILED DESCRIPTION

[0032] The technical solutions in the embodiments of the present invention will be described clearly and completely below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments.

[0033] like Figures 1 to 3 As shown, a phase change-based silica gel dehumidification wheel device provided by the present invention includes a dehumidification wheel 1, a dehumidification wheel frame 2, a purge air cooling device 3 and a temperature sensor 4; the dehumidification wheel 1 is installed in the dehumidification wheel frame 2, and the dehumidification wheel frame 2 is provided with partition fences, and the partition fences divide one side of the dehumidification wheel 1 into a dehumidification zone 1-1, a regeneration zone 1-2 and a purge zone 1-3; the matrix layer of the dehumidification wheel 1 is coated with an adsorbent layer 5 and a phase change material matrix layer 6, and the coating structure adopts a phase change material matrix layer 6 coated between two adsorbent layers 5 in the air flow channel of the dehumidification wheel along the wall thickness direction.

[0034] A heater is installed on one side of the regeneration zone 1-2 of the dehumidification wheel 1 (the prior art is not described here in detail), and a purge air cooling device 3 is provided in front of the purge air inlet of the purge zone 1-3 of the dehumidification wheel 1 for cooling the purge air; a temperature sensor 4 is provided at the purge zone outlet of the purge zone 1-3 of the dehumidification wheel 1, and the temperature sensor 4 is electrically connected to the control system, and the temperature set by the temperature sensor 4 is the inlet temperature of the treated air. The purge air cooling device 3 is controlled according to the real-time value collected by the temperature sensor 4: when the temperature of the temperature sensor is higher than the inlet temperature of the treated air, the temperature sensor 4 controls to increase the cooling capacity of the purge air cooling device 3 or reduce the cooling temperature; when the temperature of the temperature sensor is lower than the inlet temperature of the treated air, the temperature sensor 4 controls to reduce the cooling capacity of the purge air cooling device 3 or increase the cooling temperature.

[0035] Furthermore, the amount of phase change material added in the phase change material matrix layer does not exceed 30% of the total mass of the dehumidification wheel.

[0036] Furthermore, the phase change temperature of the phase change material should be selected to be 1°C higher than the inlet temperature of the processed air during operation. The phase change latent heat in the phase change material and the amount of phase change material added should satisfy the following calculation formula:

[0037]

[0038] Where: Q L is the phase change latent heat of the phase change material (unit: kJ / kg), q st is the adsorption heat of the adsorbent material (in kJ / kg), W(T l ,p v ) is the phase transition temperature T l , process air inlet water vapor partial pressure p v The corresponding equilibrium adsorption capacity (unit: kg / kg) is as follows: m is the mass ratio of the adsorbent in the dehumidification wheel to the whole dehumidification wheel (should not exceed 50% of the total mass of the wheel), and f is the mass ratio of the phase change material in the dehumidification wheel body.

[0039] Furthermore, in order to ensure the adsorption capacity and strength structure of the dehumidification wheel, the mass proportion f of the phase change material should not exceed 30%, and the mass proportion m of the adsorbent to the whole dehumidification wheel should not exceed 50%.

[0040] In the present invention, the angles occupied by the dehumidification zone 1-1 and the regeneration zone 1-2 in the dehumidification wheel 1 are defined as α° and β°, respectively; the dehumidification zone angle α° is greater than the regeneration zone angle β°, and the average adsorption rate and desorption rate of the adsorbent material from non-adsorption to adsorption saturation in the dehumidification zone angle α° and the regeneration zone angle β° are calculated according to the following formula:

[0041]

[0042] Where: r is the dehumidification wheel speed (unit: r / h), R ad and R de are the adsorption rate and desorption rate of the dehumidification wheel (in kg / (kg·s));

[0043] The operating speed of the dehumidification wheel should be determined by trial calculation so that the selected speed satisfies (360°-α-β)=5~10°.

[0044] The present invention also provides an application method of a phase change-based dehumidification wheel device, the steps of which are as follows:

[0045] like Figure 1 As shown, A. processed air; B. supply air; C. purge air; D. regeneration air.

[0046] S1: The air A to be treated enters the dehumidification zone of the dehumidification wheel after passing through the dehumidification wheel 1. The phase change material in the matrix layer of the dehumidification wheel stores the adsorption heat generated by the adsorbent layer in the adsorption process in the phase change latent heat of the phase change material, thereby controlling the air temperature at the outlet of the treated air and the temperature of the dehumidification wheel at 26°C. At the same time, the adsorption heat stored in the phase change latent heat of the phase change material is stored in the purge zone and cooled by the surface cooler used by the purge air cooling device through cold air, ensuring that the adsorbent layer still has water vapor adsorption capacity when entering the dehumidification zone;

[0047] The dehumidified air is divided into two routes, one is the supply air B, accounting for 90% of the total processed air flow, and the other is the purge air C, accounting for 10% of the total processed air flow;

[0048] S2: The purge air cooling device is controlled according to the real-time value collected by the temperature sensor: when the temperature of the temperature sensor is higher than the process air inlet temperature, the cooling capacity of the purge air cooling device should be increased or the cooling temperature should be lowered; when the temperature of the temperature sensor is lower than the process air inlet temperature, the cooling capacity of the purge air cooling device should be reduced or the cooling temperature should be increased.

[0049] The following is a detailed description of the specific parameters of the embodiment:

[0050] Example

[0051] The phase change temperature of the phase change material is selected to be 26°C; the amount of the phase change material added can be selected to be 30% of the total weight, and the proportion of the adsorbent in the dehumidification wheel to the total weight is 50%. According to the relative humidity of the treated air of 50%, the equilibrium adsorption amount W of the silica gel can be found to be 0.284kg / kg, and the adsorption heat under the equilibrium adsorption amount is further calculated to be 2552kJ / kg. Therefore, according to the calculation formula of the present invention, it can be determined that the phase change latent heat of the selected phase change material should be about 1208kJ / kg.

[0052] According to the simulation results, the average adsorption rate of silica gel under the above working conditions is 0.0022kg / (kg·s)), and the average desorption rate is 0.0024kg / (kg·s)). By trial calculation, the rotation speed when the purge zone angle is between 5° and 10° is about 14.2r / h. It can be determined that the dehumidification zone angle α is about 183°, the regeneration zone angle is about 168°, and the purge zone angle is 9°.

[0053] The purge zone 1-3 is used to cool the dehumidification wheel 1. The cold water flow of the surface cooler is controlled by the air temperature sensor 4 arranged at the outlet of the purge zone, and the outlet air temperature of the purge zone 1-3 is controlled to be 25°C;

[0054] The purge air cooling device 3 is controlled according to the data of the temperature sensor 4: when the temperature of the temperature sensor 4 is higher than 25°C, the cold water flow of the surface cooler is increased; when the temperature of the temperature sensor 4 is lower than 25°C, the cold water flow of the surface cooler is reduced.

[0055] In this embodiment, by adding phase change material in the dehumidification wheel 1, the air outlet temperature of the processed air and the dehumidification wheel temperature can be controlled to be 26°C, and the adsorption heat generated during the adsorption process is stored in the phase change latent heat of the phase change material. This part of the heat is cooled by cold air during the purge, 1-3, ensuring that it still has water vapor adsorption capacity when entering the dehumidification zone 1-1.

[0056] In the prior art, since the conventional dehumidification wheel without adding phase change material is affected by the adsorption heat during the adsorption process, the temperature of the dehumidification wheel and the outlet of the treated air will increase.

[0057] Compared with conventional dehumidification wheels, the present invention has the following beneficial effects:

[0058] 1. The equilibrium adsorption capacity of the adsorbent layer decreases with increasing temperature, so the dehumidification wheel with added phase change material has a higher equilibrium adsorption capacity and dehumidification capacity.

[0059] 2. The amount of phase change material added and the latent heat of phase change used in this method just meet the requirement that the adsorption heat after adsorption is exactly equal to the latent heat of phase change. When entering the regeneration zone 1-2, too much regeneration heat is not wasted to supplement the latent heat of phase change, thereby ensuring the efficiency of the regeneration process.

[0060] The present invention adds phase change material in the matrix layer of the dehumidification wheel 1 to ensure that the adsorption process is not an isothermal process, reduce the adsorbent temperature and the treated air temperature increase caused by the adsorption heat of the adsorption process, and thus improve the equilibrium adsorption capacity and dehumidification capacity of the adsorbent.

[0061] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present invention.

[0062] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0063] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical scheme and inventive concept of the present invention within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

Claims

1. A phase change based dehumidification wheel device, characterized in that: The invention comprises a dehumidification wheel (1), a dehumidification wheel frame (2), a purge air cooling device (3) and a temperature sensor (4); the dehumidification wheel (1) is arranged in the dehumidification wheel frame (2), the dehumidification wheel frame (2) is provided with a partition bar, and the partition bar divides the two sides of the dehumidification wheel (1) into a dehumidification zone (1-1), a regeneration zone (1-2) and a purge zone (1-3); an adsorbent layer (5) and a phase change material matrix layer (6) are coated on the matrix layer of the dehumidification wheel (1); and a purge air cooling device (3) is provided at the purge air inlet of the dehumidification wheel (1); The amount of phase change material added in the phase change material matrix layer (6) does not exceed 30% of the total mass of the dehumidification wheel (1); The phase change latent heat and the amount of phase change material added in the phase change material should satisfy the following calculation formula: Where: Q L is the phase change latent heat of the phase change material (unit: kJ / kg), q st is the adsorption heat of the adsorbent material (unit: kJ / kg), W(T l ,p v ) is the phase transition temperature T l , process air inlet water vapor partial pressure p v The corresponding equilibrium adsorption capacity (unit: kg / kg) is as follows: m is the mass ratio of the adsorbent in the dehumidification wheel to the whole dehumidification wheel (should not exceed 50% of the total mass of the wheel), and f is the mass ratio of the phase change material in the dehumidification wheel body; The angle of the dehumidification zone (1-1) in the dehumidification wheel (1) is defined as the dehumidification zone angle α°, and the angle of the regeneration zone (1-2) in the dehumidification wheel (1) is defined as the regeneration zone angle β°; the dehumidification zone angle α° is greater than the regeneration zone angle β°, and the average adsorption rate and desorption rate of the adsorbent material from non-adsorption to adsorption saturation in the dehumidification zone angle α° and the regeneration zone angle β° are calculated according to the following formula: Where: r is the dehumidification wheel speed (unit: r / h), R ad and R de are the adsorption rate and desorption rate of the dehumidification wheel (in kg / (kg·s)); The operating speed of the dehumidification wheel (1) should be determined by trial calculation so that the selected speed satisfies (360°-α-β)=5-10°.

2. A phase change based dehumidification wheel device according to claim 1, characterized in that: A temperature sensor (4) is provided at the outlet of the purge zone (1-3) of the dehumidification wheel (1). The temperature sensor (4) is electrically connected to a control system. The temperature set by the temperature sensor (4) is the inlet temperature of the treated air.

3. A phase change based dehumidification wheel device according to claim 2, characterized in that: The purge air cooling device (3) is arranged before the purge air inlet of the dehumidification wheel (1) for cooling the purge air; the phase change temperature of the phase change material should be selected to be 1°C higher than the inlet temperature of the treated air during operation.

4. An application method of a phase change based dehumidification wheel device according to any one of claims 1 to 3, characterized in that: Here are the steps: S1: After the air A to be treated enters the dehumidification wheel (1), it is dehumidified by the dehumidification zone (1-1) of the dehumidification wheel (1). The phase change material in the phase change material matrix layer (6) added to the matrix layer of the dehumidification wheel (1) stores the adsorption heat generated by the adsorbent layer (5) in the adsorption process in the phase change latent heat of the phase change material, thereby controlling the air temperature at the outlet of the treated air and the temperature of the dehumidification wheel (1) at 26°C. At the same time, the adsorption heat stored in the phase change latent heat of the phase change material is stored in the purge zone (1-3) and cooled by the surface cooler used by the purge air cooling device (3) through cold air, thereby ensuring that the adsorbent layer (5) still has water vapor adsorption capacity when entering the dehumidification zone (1-1); After dehumidification, it is divided into two routes, one is supply air B, accounting for 90% of the total processed air flow, and the other is purge air C, accounting for 10% of the total processed air flow; S2: The purge air cooling device (3) is controlled according to the real-time value collected by the temperature sensor (4): when the temperature of the temperature sensor is higher than the inlet temperature of the processed air, the cooling capacity of the purge air cooling device (3) should be increased or the cooling temperature should be reduced; when the temperature of the temperature sensor is lower than the inlet temperature of the processed air, the cooling capacity of the purge air cooling device (3) should be reduced or the cooling temperature should be increased.

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