Rotary direct evaporation humidification and refrigeration equipment suitable for plateau low-pressure extremely dry environment and optimization design method of rotary direct evaporation humidification and refrigeration equipment

Abstract

The rotary direct evaporation humidification and refrigeration equipment suitable for the plateau low-pressure extremely dry environment comprises a shell, a first rotating shaft is arranged in the shell, and spiral Savonius type wings and a driving motor are installed on the first rotating shaft. The spiral Savonius type wing comprises a supporting piece and a plurality of wing bodies arranged on the outer surface of the supporting piece, and the wing bodies are all made of porous materials. The supporting piece is mounted on the first rotating shaft, and a first cavity is formed in the supporting piece; a second cavity communicating with the first cavity is formed in each wing, and a second through hole is formed in the surface of each wing. Compared with the prior art, the problem that traditional humidifying equipment cannot work normally or is low in humidifying efficiency in the plateau low-pressure extremely dry environment is solved, and the humidifying efficiency is higher. Secondly, through the design of porous capillary replenishment and regular through hole'synergistic interaction ', three mechanisms of interface amplification, boundary layer fracture and capillary-centrifugal coupling are organically fused, and the obtained evaporation acceleration and convective mass transfer enhancement effects are far better than respective independently optimized accumulation.

Description

Technical Field

[0001] The present invention relates to the technical field of humidifiers, and in particular to a rotary direct evaporation humidifying refrigeration device suitable for low-pressure and extremely dry environments on plateaus and an optimization design method thereof. Background Art

[0002] A humidifier is a device used to increase indoor humidity. Traditional humidifiers are typically designed for normal-pressure environments. However, in the low pressure (500–600 hPa) and extremely dry conditions (relative humidity <30%) found on the plateau, such as in the Qinghai-Tibet Plateau, northern Shaanxi, and Shanxi, the air density decreases, reducing the number of air molecules per unit volume. This weakens the air's ability to absorb and carry water vapor due to the sparse molecular density. Consequently, traditional humidifiers may not function properly or experience low humidification efficiency in these low-pressure, extremely dry conditions. Summary of the Invention

[0003] The present invention solves the problem that existing humidification equipment cannot work normally or has low humidification efficiency in the low-pressure and extremely dry environment of the plateau by providing a rotary direct evaporation humidification refrigeration equipment suitable for the low-pressure and extremely dry environment of the plateau and its optimization design method.

[0004] To achieve the above-mentioned purpose, the present invention adopts the following technical solutions.

[0005] In one aspect, a rotary direct evaporation humidifying and cooling device suitable for low-pressure and extremely dry environments in plateaus is provided, comprising: a first rotating shaft having a first central through hole formed therein, one end of the first central through hole being a water inlet and the other end being sealed;

[0006] a spiral Savonius-type wing mounted on the first rotating shaft at an end away from the water inlet;

[0007] a drive motor located between the water inlet and the spiral Savonius-shaped wings, configured to drive the first rotating shaft to rotate; and a housing, wherein the first rotating shaft, the drive motor, and the spiral Savonius-shaped wings are all mounted within the housing, and an air outlet is provided on an end of the housing proximate to the spiral Savonius-shaped wings;

[0008] The spiral Savonius-type wing comprises a support member and a plurality of wings; wherein:

[0009] The support member is made of a porous material and has a second central through hole therein, through which the first rotating shaft passes; a first through hole is formed on the side wall of the portion of the first rotating shaft located within the second central through hole; a first cavity is formed between the inner and outer walls of the support member;

[0010] The multiple wings are evenly distributed on the outer surface of the support member, and a second cavity connected to the first cavity is provided in each wing along the extension direction of the wing. A plurality of second through holes connected to the second cavity are opened on the surface of the wing.

[0011] After the water reaches the position of the second central through hole through the water inlet and the first central through hole in turn, the water is transferred to the first cavity and the second cavity through the first through hole and the micropores of the support member by capillary action and centrifugal action, and finally evenly distributed to the surface of the wing through the second through hole on the wing and rapidly diffuses on the surface, and is ejected from the air outlet through strong convection to achieve efficient evaporation. During the evaporation process, water absorbs the surrounding heat (latent heat release), which reduces the indoor temperature and ultimately increases the indoor humidity. In addition, the spiral Savonius-type wing adopted in the present invention enables the wing to maintain positive torque within the full range of rotation angles, thereby improving the average power coefficient and fluid uniformity. Compared with existing traditional humidification equipment, the present invention has higher humidification efficiency in low-pressure and extremely dry environments on the plateau.

[0012] In some embodiments, the portion of the first rotating shaft located within the second central through hole is surrounded by a plurality of strip support members that are staggered and spaced apart, and the gaps between adjacent strip support members form the first through hole. In this way, not only can the weight of the component be reduced by approximately 45%, thereby improving the power coefficient under low-speed conditions, but it can also achieve axial deceleration and shear dispersion of the water flow, thereby applying resistance to the water flow, reducing the axial flow velocity, extending the residence time of water in the evaporation zone, increasing the contact opportunity between water and air, and enhancing the heat and mass exchange between water and air. The shear function disperses the water into fine droplets or thin films, significantly expanding the evaporation contact area. After shearing, the water flow is evenly distributed in the cross section of the channel, avoiding local velocities that are too large or too small, and ensuring the stability of the evaporation process. Unlike conventional perforated channels that only provide a simple circulation function, this special structure in the present invention can both reduce the axial flow velocity and expand the evaporation contact area. The dual effects jointly improve the overall evaporation performance.

[0013] In order to ensure that the wing does not deform, in some embodiments, a support frame is provided in the second cavity, one end of the support frame is connected to the support member, and the other end is connected to the end of the wing.

[0014] In some embodiments, a partition is provided between two adjacent support frames within the first cavity, extending from one end of the support member to the other. The partition enhances structural stability and flow channel separation, preventing turbulence or interference between different flow channels, further improving fluid flow uniformity and mass transfer efficiency. It also enhances structural strength and effectively prevents deformation or displacement of the support frames under load.

[0015] In some embodiments, the wings are made of a porous material.

[0016] The effects of the above technical features are as follows: 1. Dual amplification of interface area and capillary supply: a micron-scale interconnected porous structure is formed on the wing, and the porous structure continuously forms a thin film on the pore wall through capillary action, and each second through-hole opens up a new evaporation interface behind the capillary film. In this way, the total evaporation surface area increases. At the same time, the porous medium is continuously replenished to keep the liquid film saturated. The combined force of the two makes the evaporation rate exceed the sum of only the porous structure or only the through-hole scheme. 2. Boundary layer tearing and local turbulence increase synergistically: On the flat wing, the fluid boundary layer thickness δ thickens with the process, limiting mass transfer. The microscale disturbance generated by the micropore array can slightly increase the local turbulence, but the intensity is limited; regular through-holes create shear jets and backflow vortices at the macroscale. With the combination of the two, the boundary layer is constantly torn and regenerated at the orifice, and the local convective mass transfer coefficient and Sherwood-Reynolds correlation Sh~Re 1 / 2 Sc 1 / 3 , significantly amplified, so that the mass flux j m =k c (C sat -C ∞ ) is more than 2 times higher than that of a single solution. 3. Dynamic liquid film regeneration coupled with capillary convection. Driven by centrifugal action and capillary seepage, the liquid film is continuously sucked back in the porous structure, and at the same time, it is sprayed to the back of the wing through the through-holes, and then transported to the orifice by the porous body again, forming multiple film cycles. This dynamic coupling not only prevents the liquid film from drying up, but also ensures that each pore is continuously moistened, further improving the local and overall mass transfer efficiency. Therefore, through the "synergistic enhancement" design of porous capillary supply and regular through-holes, the three major mechanisms of interface amplification, boundary layer rupture, and capillary-centrifugal coupling are organically integrated, and the evaporation growth rate and convective mass transfer enhancement effect obtained far exceed the accumulation of their respective individual optimizations.

[0017] In some embodiments, the surface of the wing is provided with a plurality of grooves along the axial direction of the support member. These grooves can reduce inlet and outlet airflow resistance, guide airflow evenly along the surface, improve surface convection heat transfer coefficient, and increase overall heat transfer efficiency by 10-15%.

[0018] In some embodiments, the wing surfaces are covered with a hydrophilic coating. By uniformly coating the wing surfaces with a hydrophilic coating, such as a polypyrrole (PCW) coating (approximately 130 μm thick), the coating, made from polypyrrole, can reduce the water contact angle to 0° and exhibit high light absorption (approximately 98.1%), promoting uniform diffusion and efficient evaporation of water across the wing surfaces.

[0019] In another aspect, a method for optimizing the design of the rotary direct evaporation humidifying refrigeration equipment suitable for the low-pressure and extremely dry environment of the plateau is provided, comprising the following steps:

[0020] S1. Obtaining a unique Pareto optimal solution for parameters to be optimized, with the product of the capillary water absorption rate and the water density being greater than or equal to the evaporation rate and the optimization objectives being minimizing the structural volume, maximizing the evaporation rate, maximizing the temperature drop, and maximizing the humidity increase, of the rotary direct evaporation humidifying and cooling device suitable for plateau low-pressure and extremely dry environments, on the premise that the product of the capillary water absorption rate and the water density is greater than or equal to the evaporation rate; wherein the parameters to be optimized include capillary permeability, water absorption path length, evaporation surface area, shaft diameter, effective aperture, and fin spacing;

[0021] S2. According to the Pareto optimal solution, respectively, obtaining simulation values ​​and experimental measurement values ​​of performance parameters; the performance parameters include evaporation rate, temperature drop, humidity increase, and power consumption of a rotary direct evaporation humidifying refrigeration device suitable for a low-pressure, extremely dry environment in a plateau;

[0022] S3, calculate the relative error between the simulation value and the experimental measurement value; if the relative error exceeds the set threshold, adjust the parameter to be optimized, and use the adjusted optimization parameter as the new Pareto optimal solution, and return to step S2; if the relative error does not exceed the set threshold, determine the current Pareto optimal solution as the optimal value of the parameter to be optimized;

[0023] The method for obtaining the simulation value includes:

[0024] S21. Establish a corresponding geometric model based on the Pareto optimal solution;

[0025] S22, performing fluid-solid coupling calculation on the geometric model to obtain three-dimensional pressure field data and three-dimensional velocity field data;

[0026] S23, calculating an evaporation rate based on the three-dimensional pressure field data and the three-dimensional velocity field data;

[0027] S24. Calculate the temperature drop, humidity increase, and power consumption based on the evaporation rate.

[0028] The above-mentioned optimization design method can maximize the performance of the equipment through parametric optimization, thereby significantly improving the humidification and cooling effects of the equipment in low-pressure and extremely dry environments on the plateau.

[0029] In some embodiments, step S1 also includes: performing a sensitivity analysis on the parameters to be optimized according to the Pareto optimal solution to obtain a sensitivity ranking of each parameter to be optimized, that is, a ranking of the degree of influence of each parameter to be optimized on the performance parameter; when adjusting the parameters to be optimized in step S3, the parameters to be optimized that have a greater impact on the performance parameter are adjusted first.

[0030] In some embodiments, the method of adjusting the parameter to be optimized includes:

[0031] like Then increase the effective aperture or reduce the wing spacing;

[0032] If ΔT exp <ΔT sim , then reduce the shaft diameter;

[0033] If P exp <P sim , then increase the shaft diameter or the length of the water absorption path;

[0034] in, is the experimental measurement value of the evaporation rate, is the simulated value of evaporation rate; ΔT exp is the experimental measurement value of the temperature drop, ΔT sim is the simulated value of temperature drop; P exp is the experimental measurement value of power consumption, P sim is the simulated value of power consumption.

[0035] The present invention has at least the following technical effects or advantages:

[0036] 1. It solves the problem that traditional humidification equipment cannot work normally or has low humidification efficiency in the low-pressure and extremely dry environment of the plateau. It has higher humidification efficiency than traditional humidification equipment in low-pressure environment.

[0037] 2. The spiral Savonius-type wing adopted in the present invention enables the wing to maintain positive torque throughout the entire rotation angle range, thereby improving the average power coefficient and fluid uniformity.

[0038] 3. Two-in-one lightweight and fluid / liquid film control: By designing the portion of the first rotating shaft located in the second central through hole to be surrounded by a plurality of strip-shaped supports at intervals and staggered, not only can the weight of the component be reduced by about 45%, thereby improving the power coefficient under low-speed conditions, but also the axial deceleration and shear dispersion of the water flow can be achieved, thereby applying resistance to the water flow, reducing the axial flow velocity, extending the residence time of water in the evaporation zone, increasing the contact opportunity between water and air, and enhancing the heat and mass exchange between water and air. The shear function disperses the water into fine droplets or thin films, significantly expanding the evaporation contact area. After shearing, the water flow is evenly distributed in the cross section of the channel, avoiding excessive or insufficient local velocity, and ensuring the stability of the evaporation process. Unlike conventional perforated channels that only provide a simple circulation function, this special structure of the present invention can both reduce the axial flow velocity and expand the evaporation contact area. The dual effects jointly improve the overall evaporation performance.

[0039] 4. Through the "synergistic enhancement" design of porous capillary supply and regular through-holes, the three major mechanisms of interface amplification, boundary layer rupture, and capillary-centrifugal coupling are organically integrated. The evaporation speed increase and convective mass transfer enhancement effect obtained far exceed the cumulative effect of each individual optimization.

[0040] 5. Grooves guide flow and reduce resistance: Grooves are set axially on the wing surface to reduce the resistance of airflow in and out, guide the airflow to be evenly distributed, improve the convective heat transfer coefficient, increase the overall heat transfer efficiency by 10-15%, and further enhance the cooling and humidification capabilities.

[0041] 6. By evenly covering the surface of the wings with a hydrophilic coating, such as a PCW coating (thickness of about 130 μm), which is made based on polypyrrole material, the water contact angle can be reduced to 0° and has a high light absorption rate (about 98.1%), thereby promoting the uniform diffusion and efficient evaporation of water on the wing surface.

[0042] 7. By providing an optimization design method for the rotary direct evaporation humidification and cooling equipment suitable for the low-pressure and extremely dry environment of the plateau, combined with multi-physics field simulation and experimental feedback closed-loop correction, parametric optimization can be achieved to optimize the equipment performance, significantly improving the humidification and cooling effects of the equipment in the low-pressure and extremely dry environment of the plateau. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] Figure 1 This is a schematic structural diagram of a rotary direct evaporation humidifying and refrigerating device suitable for low-pressure and extremely dry environments in plateaus according to one embodiment of the present invention (the right half of the housing is hidden);

[0044] Figure 2 A transverse cross-sectional view of a spiral Savonius-type wing according to an embodiment of the present invention;

[0045] Figure 3 Schematic diagram of the water flow direction within a spiral Savonius-type wing according to one embodiment of the present invention;

[0046] Figure 4 A schematic perspective view of a spiral Savonius-type wing according to an embodiment of the present invention;

[0047] Figure 5 Schematic diagram of the internal structure of a support member in one embodiment of the present invention (right half is hidden);

[0048] Figure 6 This is a schematic diagram of the internal structure of a rotary direct evaporation humidifying and refrigerating device suitable for low-pressure and extremely dry environments in plateaus according to one embodiment of the present invention (wings and the right half of the housing are omitted);

[0049] Figure 7 Schematic diagram of the direction of water flow within the first rotating shaft and the spiral Savonius-type wing in one embodiment of the present invention;

[0050] Figure 8 This is a flow chart of an optimization design method for a rotary direct evaporation humidifying and refrigerating device suitable for a low-pressure and extremely dry environment in a plateau according to one embodiment of the present invention;

[0051] Figure 9 A schematic diagram of a process for obtaining simulation values ​​of performance parameters in one embodiment of the present invention;

[0052] Figure 10 The distribution of relative humidity of the four-wing section over working time simulated by CFD in one embodiment of the present invention;

[0053] Figure 11 The steady-state temperature distribution of the four-wing section simulated by CFD in one embodiment of the present invention;

[0054] Figure 12 A bar chart showing the relationship between cooling capacity and evaporation capacity and outlet wind speed in one embodiment of the present invention;

[0055] Figure 13 Graph showing the relationship between external wind speed and rotating equipment speed in one embodiment of the present invention. DETAILED DESCRIPTION

[0056] In order to better understand the above technical solution, the above technical solution will be described in detail below with reference to the accompanying drawings and specific implementation methods.

[0057] Example 1

[0058] See also Figure 1-Figure 7 , a rotary direct evaporation humidifying and refrigerating device suitable for low-pressure and extremely dry environments in plateaus, comprising:

[0059] The first rotating shaft 1 is provided with a first central through hole 11 therein, that is, the first rotating shaft 1 is a hollow rotating shaft. One end of the first central through hole is a water inlet, which is connected to a water pipe 12, and the other end is sealed by a sealing plate.

[0060] The spiral Savonius-type wing 2 is mounted on the end of the first rotating shaft 1 away from the water inlet.

[0061] a drive motor 3 , located between the water inlet and the spiral Savonius wings 2 , for driving the first rotating shaft 1 to rotate; and

[0062] The housing 4 houses the first rotating shaft 1, the drive motor 3, and the spiral Savonius-shaped wings 2. The housing 4 is cylindrical in shape, with a groove at the top of the base 5 matching the curvature of the housing 4. The housing 4 is securely mounted within the groove. An air outlet 41 is provided on the end of the housing 4 near the spiral Savonius-shaped wings 2, with a protective support bracket 42 provided between the air outlet 41 and the spiral Savonius-shaped wings 2. In the middle of the housing 4, multiple air inlets 43 are provided along the circumference of the housing 4, between the drive motor 3 and the spiral Savonius-shaped wings 2. Preferably, the inner wall of the housing 4 extends outward to form a water reservoir 44, which can temporarily store excess liquid and maintain a stable high-humidity evaporation environment. During operation, the amount of water absorbed and supplied by the porous wings or porous medium may fluctuate. The water reservoir 44 can temporarily store excess liquid to prevent liquid film instability or loss caused by sudden increases in flow. The spiral Savonius-shaped wings 2 include a support member 21 and multiple wings 22.

[0063] in:

[0064] The support member 21 is made of a porous material and has a second central through-hole 211 defined therein, through which the first rotating shaft 1 passes. A first through-hole 13 is defined in the sidewall of the portion of the first rotating shaft 1 located within the second central through-hole 211. A first cavity 61 is defined between the inner and outer walls of the support member 21. Sealing caps 212 seal the first cavity 61 at both ends of the support member 21.

[0065] Multiple wings 22 are evenly distributed on the outer surface of the support member 21. Each wing 22 has a second cavity 62 extending along its extension, communicating with the first cavity 61. The surface of the wing 22 is provided with multiple second through-holes 221 communicating with the second cavity 62. Preferably, the wings 22 and the support member 21 are integrally formed. In practice, each wing 22 is formed by two superimposed fins, spaced apart at one end where they connect to the support member 21. The fins extend outward and gradually converge, forming the aforementioned second cavity 62 between the two fins.

[0066] As a preferred solution, the portion of the first rotating shaft 1 located within the second central through hole 211 is surrounded by a plurality of strip support members 14 that are staggered at intervals, and the gaps between adjacent strip support members 14 form the first through hole 13. In fact, the first rotating shaft 1 is composed of three sections, and the middle section with the spiral Savonius-type wings 2 is surrounded by a plurality of strip support members 14 that are staggered at intervals, such as Figure 5 shown.

[0067] As a preferred solution, a support skeleton 7 is provided in the second cavity 62 , one end of the support skeleton 7 is connected to the support member 21 , and the other end is connected to the end of the wing 22 .

[0068] As a preferred solution, a partition 8 is provided between two adjacent support frames 7 in the first cavity 61, and the partition 8 extends from one end to the other end of the support member 21. Preferably, the support frame 7 and the support member 21 are also integrally formed.

[0069] As a preferred solution, the wings 22 are made of porous material.

[0070] As a preferred solution, a plurality of grooves 222 are formed on the surface of the wing 22 along the axial direction of the support member 21 .

[0071] As a preferred solution, the surface of the wing 22 is covered with a hydrophilic coating.

[0072] During operation, under the action of a driving member (such as a water pump), water enters the first central through hole 11 in the first rotating shaft 1 from the water inlet through the water inlet pipe 12. After reaching the position of the second central through hole 211, the water is transferred to the first cavity 61 and the second cavity 62 through the first through hole 13 and the micropores of the support member 21 by capillary action and centrifugal action, and then evenly distributed to the surface of the wing 22 through the micron-level porous structure on the wing 22 and the second through hole 221 and rapidly diffuses on the surface, and finally sprayed out from the air outlet 41 through strong convection to achieve efficient evaporation.

[0073] Example 2

[0074] like Figure 8 As shown, an optimization design method for the rotary direct evaporation humidifying refrigeration equipment suitable for low-pressure and extremely dry environments on the plateau includes the following steps:

[0075] S1. Obtaining a unique Pareto optimal solution for parameters to be optimized, with the product of the capillary water absorption rate and the water density being greater than or equal to the evaporation rate and the optimization objectives being minimizing the structural volume, maximizing the evaporation rate, maximizing the temperature drop, and maximizing the humidity increase, of the rotary direct evaporation humidifying and cooling device suitable for plateau low-pressure and extremely dry environments, on the premise that the product of the capillary water absorption rate and the water density is greater than or equal to the evaporation rate; wherein the parameters to be optimized include capillary permeability, water absorption path length, evaporation surface area, shaft diameter, effective aperture, and fin spacing;

[0076] The method of solving the Pareto optimal solution by multi-objective optimization adopts the existing method. cap ·ρ w ≥Q evap Under the premise of maximizing the evaporation rate and the structural volume V totalMinimization, this embodiment uses the COBYLA (Constrained Optimization BY Linear Approximations) algorithm in the existing software COMSOL Global Optimization Study, and cooperates with the Epsilon-constraint method to construct the Pareto frontier for multi-objective optimization. The specific implementation steps are as follows:

[0077] S11. Configure GlobalOptimizationStudy① Add a new Study in ModelBuilder and select GlobalOptimization as the type;② In the Settings panel, set the optimization method (Method) to COBYLA;③ Add two objectives under the Objective node: Obj1 (Minimize): Total volume Obj1 = V total ; Obj2(Minimize): negative value of evaporation rate r Obj2 = -Q evap ;④Add inequality constraints in the Constraints node:Q cap ·ρ w -Q evap ≥0; ⑤ Define the variables to be optimized and their upper and lower limits in the DesignVariables node: Configure GlobalOptimizationStudy in the ModelBuilder of COMSOLMultiphysics, including: first, add a Study and set the type to GlobalOptimization; then, in the Settings panel, set the optimization method (Method) to COBYLA; then, under the Objective node, add two objectives, namely, minimize the total volume V total (Obj1) and minimize the negative value of evaporation rate -Q evap (Obj2); then introduce the inequality constraint Q in the Constraints node cap ·ρ w -Q evap ≥0; Finally, define the variables to be optimized and their upper and lower limits in the DesignVariables node, specifically:

[0078] ●Capillary permeability: κ∈[0.5,2.0]×10 -12 m 2 , water absorption path length: L∈[1.0,3.0]×10 -2 m, ●Evaporation surface area: A∈[5,15]×10 -3 m 2 , shaft diameter: d axle∈[0.03,0.07]m,

[0079] ●Effective aperture: d p ∈[0.2,0.7]mm, wing spacing: s p ∈[3,7]mm.

[0080] S12. Set COBYLA parameters: maximum iteration 200, convergence tolerance 1×10 -6 , initial step size 0.1, restart times 3;

[0081] S13, with a series of ∈1(0.005–0.015m 3 , step length 0.001m 3 ) impose an upper limit on Obj1, optimize Obj2 one by one, and take the last set of solutions after iteration as the Pareto optimal solution

[0082] S2. According to the Pareto optimal solution, respectively, obtaining simulation values ​​and experimental measurement values ​​of performance parameters; the performance parameters include evaporation rate, temperature drop, humidity increase, and power consumption of a rotary direct evaporation humidifying refrigeration device suitable for a low-pressure, extremely dry environment in a plateau;

[0083] The method for obtaining the experimental measurement value includes:

[0084] a) Producing a rotary direct evaporation system suitable for plateau low-pressure and extremely dry environments according to the Pareto optimal solution obtained in step S13

[0085] Humidification and refrigeration equipment prototype;

[0086] b) In the plateau low-pressure and extremely dry environment chamber, measure and record the evaporation rate: Temperature drop ΔT exp ; Change in relative humidity between the environment and the outlet ΔRH exp ;Total system power consumption P exp .

[0087] like Figure 9 As shown, the method for obtaining the simulation value of the performance parameter includes:

[0088] S21. Establish a corresponding geometric model based on the Pareto optimal solution;

[0089] S22, performing fluid-solid coupling calculation on the geometric model to obtain three-dimensional pressure field data and three-dimensional velocity field data;

[0090] S23, calculating an evaporation rate based on the three-dimensional pressure field data and the three-dimensional velocity field data;

[0091] S24. Calculate the temperature drop, humidity increase, and power consumption based on the evaporation rate.

[0092] Specifically, the steps include:

[0093] Initial geometry modeling: Use SolidWorks to build a preliminary geometry model of the equipment to provide accurate geometry data for subsequent simulations: Initial geometry modeling obtains accurate inertial and aerodynamic parameters. Build a shaft + wing CAD model in SolidWorks, mesh it, and perform static and flow estimations: Obtain the moment of inertia using the shaft mass m = 0.12 kg and radius r = 0.025 m: The wing projected area A = 0.009m 2 , resistance coefficient Cd≈1.2. Output:I axis ,Cd is used as the initial condition of Fluent simulation, which is defined as the rotational inertia and windward boundary condition respectively. The windward surface area A is calculated and the geometry is derived and the wind environment area is constructed as the domain of Fluent calculation.

[0094] Fluid-solid coupling simulation: Fluent software is used to perform fluid-solid coupling calculations, simulate the rotational response of the device under wind conditions, obtain the change of torque under external wind field, and analyze the force and flow state of the device in actual operation. In order to quantify the force characteristics between the blades and the central axis and the surrounding flow field distribution under the action of wind load, ANSYS Fluent software is used to perform fluid-solid coupling simulation in this step. First, a rotating reference frame (Multiple Reference Frame, MRF) model and a sliding mesh (Sliding Mesh) model are established in Fluent, and the three-dimensional geometry of the device is subjected to about 2×10 6 The simulation conditions include static wind (U ∞ = 0m / s) and wind (U ∞ =2m / s) and four speed settings (50rpm, 100rpm, 150rpm, 200rpm). During the solution process, the software solves the Navier–Stokes equations in a steady-state form, coupling the rotational inertia of the blades and the shaft and considering the fluid-solid exchange until the residual size converges to 10 -6After the simulation is complete, the system automatically outputs: ① the relationship between external wind speed and rotating equipment speed; ② three-dimensional pressure field p(x,y,z) data; and ③ three-dimensional velocity field v(x,y,z) data. The torque-speed data is exported in .csv format for comparing mechanical load changes under various operating conditions. The pressure and velocity fields are saved in .dat format as boundary condition inputs for multi-physics coupled simulations in the COMSOL Multiphysics platform in the next step. The torque is used to define the rotational boundary conditions, and the pressure and velocity fields are used for mapping field variables at the inlet and outlet.

[0095] Multi-physics coupling calculation: Finite volume methods such as Fluent are more accurate in solving the velocity field, but it is relatively inconvenient to directly solve the temperature and humidity field. Therefore, the present invention first derives the velocity solution obtained in Fluent, and then carries out numerical simulation of heat-humidity forced convection on the COMSOL Multiphysics platform, which is more adept at multi-physics coupling. In order to accurately predict the evaporation performance and capillary water replenishment capacity of the equipment under real operating conditions, the present invention constructs a numerical model on the COMSOL Multiphysics platform that is sequentially coupled by the "Rotating Machinery, Nonisothermal Flow" module, the "Velocity Field (Laminar Flow)" interface, the "Transport of Diluted Species" module, the "Porous Media (Porous Media)" module, and the "Porous Media Heat Conduction (Heat Transfer in Porous Media)" module, respectively giving a rotating dynamic grid, obtaining the water evaporation concentration in the air, obtaining the liquid water saturation in the matrix, and obtaining the temperature field. Accurately calculate the water evaporation rate and heat and mass transfer effect, and provide a basis for equipment performance evaluation. In order to simulate the actual operating conditions of the equipment.

[0096] Specifically, in the previous step, the wind speed-rotation speed curve M (rpm) obtained in Fluent is accurately assigned to the angular velocity of the solid domain through interpolation mapping, and the three-dimensional inlet pressure field p (x, y, z) and velocity field v (x, y, z) are used as the inlet / outlet boundary conditions of the fluid domain. Different turbulence models are selected using comsol, and the fluid-solid coupling is secondary corrected through the fully coupled solver. The velocity and pressure distribution in Fluent in the previous step is compared to verify the difference between the pressure field p (x, y, z) and the velocity field v (x, y, z) obtained between different software. In the present invention, (x, y, z) represents the coordinate value. When the error of the pressure and wind speed at the outlet probe point is less than 5%, it means that the turbulence model is adapted. The present invention adopts the k-ε turbulence model, couples the temperature and humidity fields, and obtains the heat-moisture transfer field distribution under convection. And calculates the dimensionless numbers Re, Sc, Q required for the surface convection mass transfer coefficient. evap , Q cap , the specific calculation is as follows:

[0097] ● Local flow field quantification: Reynolds number calculation can be used at each surface element, taking the characteristic length L (for example, the length of the porous medium along the

[0098] pore size in the flow direction), fluid density ρ, dynamic viscosity μ, and local flow velocity v(x,y,z):

[0099]

[0100] ●Calculation of Schmidt number: Take the diffusion coefficient of water vapor in air D AB :

[0101]

[0102] These two dimensionless numbers are completely determined by the velocity field v(x,y,z) and the known physical properties (ρ,μ,D Ab )Sure.

[0103] The Sherwood number and local mass transfer coefficient are expressed as follows for forced convection (laminar flat plate flow): Sh(x,y,z) =

[0104] 0.664Re(x,y,z) 1 / 2 Sc 1 / 3 ;

[0105] Similarly, in COMSOL, the local capillary upward mass flux can be obtained from the capillary driven pressure field Δp(x, y, z) and the capillary permeability κ: where ρ w is the density of water.

[0106] In this example, a polypyrrole-based PCW coating was selected as a candidate coating material. The experimental environment was set to a plateau low pressure of 0.1 kPa. The test results were used as boundary conditions for subsequent models. First, a capillary permeation test was performed on the material based on the Darcy two-phase flow model: the sample was placed in a 0.1 kPa environment and the permeation process parameters were recorded. The capillary permeability κ was then inferred based on the Washburn equation, using the following formula: where d p is the effective pore size of the material, and τ is the parameter of the void connectivity structure. After testing, we found that κ≈1.2×10 -12 m 2 Afterwards, the surface wettability of the material was measured: a water droplet was added to the surface of the material using a contact angle tester, and the contact angle θ was statically measured. The test showed that the polypyrrole PCW coating was superhydrophilic, with θ≈0°. The permeability κ and contact angle θ obtained from the above test, as well as the effective pore size d calculated from κ p , respectively, as the physical property parameters of the matrix material when calculated by Comsol in the above steps to improve the model prediction accuracy and ensure data consistency.

[0107] ●Total evaporation rate and system redundancy margin are integrated over the entire evaporation surface A to obtain the evaporation rate:

[0108]

[0109] Local evaporation mass flux J evap (x, y, z) can be obtained by using the convection-diffusion steady-state mass transfer equation, and the evaporation mass flux (kg / (m 2 ·s) is J evap (x,y,z)=h m (x,y,z)[c sat (T(x,y,z))-c env ], where h m (x, y, z) is the local convective mass transfer coefficient, c sat (T) is the saturated water vapor concentration (kg / m 3 ),c env is the ambient water vapor concentration (kg / m 3 ).

[0110] Similarly, capillary supply rate: Q cap =∫∫ A J cap (x,y,z)dA.

[0111] Calculate the equipment temperature drop ΔT through the heat balance relationship sim , which is calculated as follows: in, is the evaporation rate (kg / s), L v is the latent heat of vaporization of water (J / kg), m is the mass of the cooled evaporated water (kg), c p is the specific heat capacity of water (J / (kg℃)). At normal temperature and pressure, the latent heat of vaporization of water, L v The value is approximately 2.45×10 6 J / kg, specific heat capacity c p The value is approximately 4186 J / (kg·°C). The above formula can effectively predict the temperature drop of the equipment under different evaporation rate conditions, ensuring the accuracy of the cooling effect evaluation.

[0112] Humidity increase ΔRH sim The calculation is based on the evaporation rate of the equipment and the volume of the space. The temperature rise is calculated as follows: in, is the evaporation rate (kg / s), V is the room volume (m 3 ),ρ is the air density (kg / m 3 ). The air density can be calculated using the following formula: Where p is atmospheric pressure (Pa), R is the gas constant (287 J / (kg:K)), and T is the absolute temperature (K). By calculating the humidity increase, the present invention can effectively evaluate the humidity control effect of the equipment in different plateau environments.

[0113] In order to evaluate the energy consumption of equipment operation, the present invention proposes a power consumption calculation method based on evaporation rate and equipment efficiency. sim The calculation formula is: Among them, L v is the latent heat of vaporization (J / kg), and η is the equipment efficiency (0.6-0.8). By properly selecting the efficiency parameter, the energy consumption of the equipment under different operating modes can be accurately calculated, thereby providing guidance for optimizing energy conservation.

[0114] Thus, the simulation value of the performance parameter evaporation rate can be obtained Temperature drop ΔT sim , humidity increase ΔRH sim and power consumption P sim .

[0115] S3, calculate the relative error between the simulation value and the experimental measurement value; if the relative error exceeds the set threshold, adjust the parameter to be optimized, and use the adjusted optimization parameter as the new Pareto optimal solution, and return to step S2; if the relative error does not exceed the set threshold, determine the current Pareto optimal solution as the optimal value of the parameter to be optimized;

[0116] Specifically, the relative error E is calculated as follows: i :

[0117]

[0118] When any E i When the preset threshold (e.g. 5%) is exceeded, the design variables that have the greatest impact on performance (e.g. micropore diameter d) are adjusted first according to the sensitivity ranking shown in the Sobol sensitivity analysis. p , capillary path length L or fin spacing s p For example: if Increase the effective aperture or reduce the wing spacing; if ΔT exp <ΔT sim , then reduce the shaft diameter; if P exp <P sim , then increase the shaft diameter or the length of the water absorption path. Then recalculate the simulation value and the experimental measurement value according to the adjusted parameters and re-evaluate the relative error until all E i <5%. This closed-loop iteration ensures that simulation predictions are highly consistent with experimental observations.

[0119] As a preferred solution, step S1 also includes: performing a sensitivity analysis on the parameters to be optimized according to the Pareto optimal solution to obtain a sensitivity ranking of each parameter to be optimized, that is, a ranking of the degree of influence of each parameter to be optimized on the performance parameter; when adjusting the parameters to be optimized in step S3, the parameters to be optimized that have a greater impact on the performance parameter are adjusted first.

[0120] This example uses Sobol global sensitivity analysis, and the specific steps are as follows:

[0121] Take the Pareto optimal solution and the original design variable range as input;

[0122] Generate 2000 sets of samples through Latin hypercube sampling;

[0123] Calculate the response function of each design variable (evaporation rate Q evap , total volume V total )’s first-order and overall sensitivity indices;

[0124] First-order sensitivity index:

[0125]

[0126] Total sensitivity index:

[0127]

[0128] Output the first-order sensitivity index and total sensitivity index of each design variable. According to the calculation results of Sobol sensitivity analysis, rank the sensitivity of each design variable to determine the variable with the greatest impact on performance. According to the sensitivity ranking, the variables with the greatest impact on performance are adjusted first. The top three are effective aperture d p , capillary path length L, wing spacing s p .

[0129] Experimental verification

[0130] In order to verify the technical effect of the present invention, the following experiments were conducted:

[0131] Evaporation performance test: Under no equipment conditions, the evaporation rate of water is about 0.29kg / m 2 h; After starting the equipment, evaporation occurs rapidly within 2 seconds, and the moist air quickly fills the entire cavity. Figure 10 As shown, the speed is increased to 1.5 kg / m at 100 rpm. 2 ·h, when running at 8m / s, the water evaporation rate increases to 15kg / m 2 ·h, such as Figure 12 shown.

[0132] Refrigeration performance test: In a windless environment, the surface temperature of the device drops from 25°C to 17°C (8°C) after running for 1 hour. The relationship between the output wind speed and angular velocity of the device is as follows: Figure 13 As shown in the figure, there is a significant positive correlation. Under the given output wind speed of 4m / s, the equipment further improves the cooling effect, and the average air temperature drops by about 12℃. Figure 11 As shown, the temperature decreases along the radial direction, and the maximum temperature difference of the air in the cavity reaches 30K.

[0133] Parameter optimization verification: By adjusting the central axis diameter d axle , effective aperture d p , capillary path length L, wing spacing s p Determine the initial jet velocity range (1–5m / s) to achieve a humidification range from 1m to 5m. At the outlet, it is 5m / s, for 20m 3 After running in the closed space for one hour, the indoor temperature was finally reduced by 5°C and the humidity was controlled in the range of 75%-85%.

[0134] Experiment 1: At 700 hPa and 40°C, the device used a central axis water suction design and spiral wings. The speed was set to 1000 rpm, with an initial jet velocity of 8 m / s. The test results showed that the humidification range was approximately 5 meters, and the indoor humidity increased to approximately 75%. Experiment 2: At 800 hPa and 20°C, the speed was increased to 300 rpm, with an initial jet velocity of 5 m / s. The test showed that the humidification range was reduced to 3 meters, but the humidity was still increased to 85%, with a more significant cooling effect.

[0135] In the description provided herein, a large number of specific details are described. However, it is understood that embodiments of the present invention can be practiced without these specific details. In some instances, well-known methods, structures, and techniques are not shown in detail so as not to obscure the understanding of this description.

[0136] Similarly, it should be understood that in order to streamline the present disclosure and aid understanding of one or more of the various inventive aspects, in the above description of exemplary embodiments of the invention, various features of the invention are sometimes grouped together into a single embodiment, figure, or description thereof. However, this disclosed method should not be interpreted as reflecting an intention that the claimed invention requires more features than are expressly recited in each claim. Rather, as reflected in the claims, inventive aspects lie in less than all the features of the individual embodiments disclosed above. Accordingly, the claims that follow the detailed description are hereby expressly incorporated into this detailed description, with each claim standing on its own as a separate embodiment of the invention.

[0137] Those skilled in the art will appreciate that the modules, units, or groups of devices in the examples disclosed herein may be arranged in the device described in the embodiment, or alternatively may be located in one or more devices different from the devices in the examples. The modules in the aforementioned examples may be combined into one module or further divided into multiple submodules.

[0138] It will be appreciated by those skilled in the art that the modules in the devices of the embodiments may be adaptively changed and arranged in one or more devices different from the embodiments. The modules or units or groups in the embodiments may be combined into one module or unit or group, and furthermore they may be divided into a plurality of submodules or subunits or subgroups. All features disclosed in this specification (including the accompanying claims, abstracts and drawings) and all processes or units of any method or device disclosed herein may be combined in any combination, except that at least some of such features and / or processes or units are mutually exclusive. Unless expressly stated otherwise, each feature disclosed in this specification (including the accompanying claims, abstracts and drawings) may be replaced by an alternative feature providing the same, equivalent or similar purpose.

[0139] Furthermore, those skilled in the art will appreciate that although some embodiments described herein include certain features and not other features included in other embodiments, the combination of features from different embodiments is intended to be within the scope of the invention and to form different embodiments.

[0140] In addition, some of the embodiments are described herein as methods or combinations of method elements that can be implemented by a processor of a computer system or by other devices that perform the functions described. Thus, a processor having the necessary instructions for implementing the method or method element forms a device for implementing the method or method element. Furthermore, the elements described herein of the device embodiments are examples of devices for implementing the functions performed by the elements for the purpose of implementing the invention.

[0141] The various techniques described herein may be implemented in conjunction with hardware or software, or a combination thereof. Thus, the methods and apparatus of the present invention, or certain aspects or portions of the methods and apparatus of the present invention, may take the form of program code (i.e., instructions) embedded in a tangible medium, such as a floppy disk, CD-ROM, hard drive, or any other machine-readable storage medium, wherein when the program is loaded into a machine such as a computer and executed by the machine, the machine becomes an apparatus for practicing the present invention.

[0142] When the program code is executed on a programmable computer, the computing device generally includes a processor, a storage medium readable by the processor (including volatile and non-volatile memory and / or storage elements), at least one input device, and at least one output device. The memory is configured to store the program code; the processor is configured to execute the method of the present invention according to the instructions in the program code stored in the memory.

[0143] By way of example and not limitation, computer-readable media include computer storage media and communication media. Computer-readable media include computer storage media and communication media. Computer storage media stores information such as computer-readable instructions, data structures, program modules, or other data. Communication media generally embodies computer-readable instructions, data structures, program modules, or other data in a modulated data signal such as a carrier wave or other transport mechanism, and includes any information delivery media. Combinations of any of the above are also included within the scope of computer-readable media.

[0144] As used herein, unless otherwise specified, the use of ordinal numbers "first," "second," "third," etc. to describe common objects merely indicates that different instances of similar objects are involved and are not intended to imply that the objects so described must have a given order in time, space, ranking, or in any other manner.

[0145] Although the present invention has been described with respect to a limited number of embodiments, it will be apparent to those skilled in the art, having benefit of the foregoing description, that other embodiments are contemplated within the scope of the invention thus described. Furthermore, it should be noted that the language used in this specification has been selected primarily for readability and didactic purposes, rather than for the purpose of explaining or limiting the subject matter of the present invention. Consequently, many modifications and variations will be apparent to those skilled in the art without departing from the scope and spirit of the appended claims. The disclosure of the present invention is intended to be illustrative rather than restrictive of the scope of the invention, which is defined by the appended claims.

[0146] Finally, it should be noted that the present invention does not explain in detail the common knowledge recognized by technicians in this field. The above is only a specific embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A rotary direct evaporation humidifying and refrigerating device suitable for low-pressure and extremely dry environments in plateaus, characterized in that: include: A first rotating shaft having a first central through hole formed therein, one end of the first central through hole being a water inlet and the other end being sealed; a spiral Savonius-type wing mounted on the first rotating shaft at an end away from the water inlet; a drive motor, located between the water inlet and the spiral Savonius-shaped wing, for driving the first rotating shaft to rotate; and a housing, wherein the first rotating shaft, the drive motor, and the spiral Savonius-shaped wings are all mounted in the housing, and an air outlet is provided on one end of the housing near the spiral Savonius-shaped wings; The spiral Savonius-type wing comprises a support member and a plurality of wings; wherein: The support member is made of a porous material and has a second central through hole therein, through which the first rotating shaft passes; a first through hole is formed on the side wall of the portion of the first rotating shaft located within the second central through hole; a first cavity is formed between the inner and outer walls of the support member; The multiple wings are evenly distributed on the outer surface of the support member, and a second cavity connected to the first cavity is provided in each wing along the extension direction of the wing. A plurality of second through holes connected to the second cavity are opened on the surface of the wing.

2. The rotary direct evaporation humidifying and refrigerating equipment suitable for low-pressure and extremely dry environments in plateaus according to claim 1 is characterized in that: The portion of the first rotating shaft located in the second central through hole is surrounded by a plurality of strip-shaped support members that are staggered and spaced apart, and the gaps between adjacent strip-shaped support members form the first through hole.

3. The rotary direct evaporation humidifying refrigeration equipment suitable for low-pressure and extremely dry environments in plateaus according to claim 1 or 2, characterized in that: A support frame is provided in the second cavity, one end of the support frame is connected to the support member, and the other end is connected to the end of the wing.

4. The rotary direct evaporation humidifying and refrigerating device suitable for low-pressure and extremely dry environments in plateaus according to claim 3 is characterized in that: In the first cavity, a partition is provided between two adjacent support frames, and the partition extends from one end to the other end of the support member.

5. The rotary direct evaporation humidifying refrigeration equipment suitable for low-pressure and extremely dry environments in plateaus according to claim 1 or 2, characterized in that: The wing is made of porous material, and a plurality of second through holes are opened on the surface of the wing.

6. The rotary direct evaporation humidifying and refrigerating device suitable for low-pressure and extremely dry environments in plateaus according to claim 5, characterized in that: A plurality of grooves are formed on the surface of the wing along the axial direction of the support member.

7. The rotary direct evaporation humidifying refrigeration equipment suitable for low-pressure and extremely dry environments in plateaus according to claim 1 or 2, characterized in that: The surface of the wing is covered with a hydrophilic coating.

8. An optimization design method for a rotary direct evaporation humidifying refrigeration device suitable for a low-pressure, extremely dry environment in a plateau according to any one of claims 1 to 7, characterized in that: The steps include: S1. Obtaining a unique Pareto optimal solution for parameters to be optimized, with the product of the capillary water absorption rate and the water density being greater than or equal to the evaporation rate and the optimization objectives being minimizing the structural volume, maximizing the evaporation rate, maximizing the temperature drop, and maximizing the humidity increase, of the rotary direct evaporation humidifying and cooling device suitable for plateau low-pressure and extremely dry environments, on the premise that the product of the capillary water absorption rate and the water density is greater than or equal to the evaporation rate; wherein the parameters to be optimized include capillary permeability, water absorption path length, evaporation surface area, shaft diameter, effective aperture, and fin spacing; S2. According to the Pareto optimal solution, respectively, obtaining simulation values ​​and experimental measurement values ​​of performance parameters; the performance parameters include evaporation rate, temperature drop, humidity increase, and power consumption of a rotary direct evaporation humidifying refrigeration device suitable for a low-pressure, extremely dry environment in a plateau; S3, calculating the relative error between the simulation value and the experimental measurement value; if the relative error exceeds the set threshold, adjusting the parameters to be optimized, and taking the adjusted optimization parameters as the new Pareto optimal solution, and returning to step S2; If the relative error does not exceed the set threshold, the current Pareto optimal solution is determined to be the optimal value of the parameter to be optimized; The method for obtaining the simulation value includes: S21. Establish a corresponding geometric model based on the Pareto optimal solution; S22, performing fluid-solid coupling calculation on the geometric model to obtain three-dimensional pressure field data and three-dimensional velocity field data; S23, calculating an evaporation rate based on the three-dimensional pressure field data and the three-dimensional velocity field data; S24. Calculate the temperature drop, humidity increase, and power consumption based on the evaporation rate.

9. The optimization design method according to claim 8, characterized in that: After step S1, it also includes: performing a sensitivity analysis on the parameters to be optimized according to the Pareto optimal solution to obtain a sensitivity ranking of each parameter to be optimized, that is, a ranking of the degree of influence of each parameter to be optimized on the performance parameter; when adjusting the parameters to be optimized in step S3, the parameters to be optimized that have a greater impact on the performance parameter are adjusted first.

10. The optimization design method according to claim 8 or 9, characterized in that: Methods for adjusting the parameters to be optimized include: Then increase the effective aperture or reduce the wing spacing; If ΔT exp <ΔT sim , then reduce the shaft diameter; If P exp <P sim , then increase the shaft diameter or the length of the water absorption path; in, is the experimental measurement value of the evaporation rate, is the simulated value of evaporation rate; ΔT exp is the experimental measurement value of the temperature drop, ΔT sim is the simulated value of temperature drop; P exp is the experimental measurement value of power consumption, P sim is the simulated value of power consumption.

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