Humidifier and optimization method thereof

Abstract

The invention relates to a humidifier and an optimization method thereof.The humidifier comprises a shell and a humidifying assembly arranged on the shell, the shell is provided with an air inlet and an air outlet, the humidifier is characterized in that the humidifying assembly comprises a humidifying bin and a centrifugal pump arranged in the humidifying bin, the peripheral wall of the humidifying bin is composed of permeable membranes, the humidifying bin is filled with liquid, and the centrifugal pump is arranged in the shell. The liquid can pass through the permeable membrane under the action of the centrifugal pump, and then gaseous water vapor is generated. The humidifier has the advantages that the humidifier adopts the permeable membrane for humidification, the humidification technology is to increase the content of water vapor in air instead of small-particle liquid water, the humidification technology belongs to a phase change humidification mode, and rime fog cannot occur; in addition, due to the fact that a phase-change humidification mode is adopted, a condensation process is needed before the humidification effect disappears, and compared with a non-phase-change humidification technology, the humidification technology has the advantage that the humidification effect is longer.

Description

Technical Field

[0001] The present invention relates to the technical field of humidification, and particularly to a humidifier and an optimization method thereof. Background Art

[0002] The comfort of the human body is greatly affected by the relative humidity of the air. Dry air can cause the rapid loss of epidermal moisture on the skin, which in turn leads to damage to the barrier function and indirectly affects the human immune system. In the field of electronic industrial production, a relatively low relative humidity will cause electrostatic accumulation, damage electronic equipment, and affect product quality. Therefore, whether considering human health or industrial production, reasonable control of humidity is very important.

[0003] Traditional humidification technologies mainly include wet curtain humidification, high-pressure humidification, ultrasonic humidification, centrifugal humidification, etc. Wet curtain humidification uses a water circulation system to infiltrate a porous wet curtain. When air flows through the wet curtain, it will carry away moisture to increase the air humidity. However, the disadvantage of wet curtain humidification is that the humidity increase is limited, and the wet curtain needs to be maintained regularly to prevent bacteria from growing; high-pressure humidification uses a high-pressure pump to press water to dozens of megapascals and then sprays it through a nozzle. After that, the water will be atomized into ultra-fine water particles (5-10 μm); however, the disadvantage of high-pressure humidification is that the equipment is complex and the cost is high; ultrasonic humidification uses a high-frequency vibration sheet to break water into micron-sized water mist, which is then diffused throughout the room by a fan. However, the disadvantage of ultrasonic humidification is that it is sensitive to water quality, and hard water is likely to produce white powder; centrifugal humidification is to throw water out by a high-speed rotating disk, which hits the atomization ring around the disk to form fine water mist. Although the centrifugal humidification technology has a large humidification capacity and low energy consumption, the water mist particles formed by it are relatively large and are easy to settle into water stains.

[0004] In order to solve the problem of too large water mist particles, for example, a Chinese utility model patent with the patent number ZL201921976259.4 (the authorized announcement number is CN211060308U) discloses an air humidification unit and an air humidifier provided with the air humidification unit. This patent can better suppress the water leakage phenomenon and at the same time ensure that the water mist particles will not be too large. However, even so, the centrifugal humidification technology itself has relatively large defects, that is, it will produce white fog (white fog is a phenomenon caused by the existence of small particles of liquid water in the air). The principles of humidification technologies that produce white fog (including high-pressure humidification and ultrasonic humidification) are all the physical fragmentation process of water and no phase change occurs. This non-phase change atomization humidification technology has problems in terms of comfort and aesthetics; moreover, because a large number of small water droplets are dispersed in the air, they will settle to the ground or adhere to the cavity over time, causing the ground and walls to be wet, and even causing the wall paint to fall off in the long run; furthermore, small water droplets are more likely to dissipate than water vapor, resulting in the humidification effect not lasting long. Therefore, further improvement of the existing technology is needed. Summary of the Invention

[0005] The first technical problem to be solved by the present invention is to provide a humidifier that does not produce white fog and has a longer-lasting humidifying effect in view of the above-mentioned prior art.

[0006] The second technical problem to be solved by the present invention is to provide an optimization method for the above humidifier, which can obtain a better humidifying effect.

[0007] The technical solution adopted by the present invention to solve the above first technical problem is as follows: A humidifier includes a housing and a humidifying component provided in the housing. The housing has an air inlet and an air outlet. It is characterized in that: The humidifying component includes a humidifying chamber and a centrifugal pump provided in the humidifying chamber. The peripheral wall of the humidifying chamber is composed of a permeable membrane. The interior of the humidifying chamber is filled with a liquid, and the liquid can pass through the permeable membrane under the action of the centrifugal pump, thereby generating gaseous water vapor.

[0008] In order to fix the permeable membrane, the humidifying chamber includes a first frame and a second frame arranged inside and outside, and the permeable membrane is provided between the first frame and the second frame.

[0009] In order to enable the humidified air to flow out from the air outlet, the air outlet is provided at the top of the housing, and a blower is provided in the housing facing the air outlet.

[0010] In order to make the structure compact and reduce costs, a motor and a transmission shaft driven by the motor are further provided in the housing. One end of the transmission shaft is connected to the blower, and one end of the transmission shaft passes through the humidifying chamber and is connected to the centrifugal pump. By using one motor, the centrifugal pump and the blower can be driven to rotate, so this structure does not require two motors, reducing costs.

[0011] In order to collect the condensed water condensed on the outer side of the permeable membrane, a water storage tank with an open top is further provided at the bottom of the housing. The humidifying chamber is provided above the water storage tank, and the vertical projection of the humidifying chamber falls into the water storage tank.

[0012] In order to realize the recycling of the condensed water, a water pumping mechanism is provided in the housing to pump the water in the water storage tank back into the humidifying chamber.

[0013] The technical solution adopted by the present invention to solve the above second technical problem is as follows: An optimization method for a humidifier as described above, which is characterized by including the following steps:

[0014] Step 1: Simulate and optimize the pressure inside the membrane of the permeable membrane to obtain the design variables of the centrifugal pump corresponding to the pressure inside the membrane; and use the design variables of the centrifugal pump corresponding to the maximum pressure inside the membrane as the optimal design variables of the centrifugal pump;

[0015] Step 2: Conduct mass transfer simulation on the permeable membrane to obtain the relationship between the mass transfer rate on the outer side of the permeable membrane and the pressure on the inner side of the membrane;

[0016] Specifically: Use the pressure on the inner side of the membrane obtained in Step 1 and the corresponding centrifugal pump design variables at the pressure on the inner side of the membrane to conduct mass transfer simulation on the inner side of the permeable membrane to obtain the mass transfer rate on the outer side of the permeable membrane; and use the pressure on the inner side of the membrane as the design variable to simulate and obtain several groups of mass transfer rates on the outer side of the permeable membrane, and obtain the relationship between the mass transfer rate on the outer side of the permeable membrane and the pressure on the inner side of the membrane;

[0017] Step 3: Take the mass transfer rate on the outer side of the permeable membrane calculated according to the relationship in Step 2 as the boundary condition, simulate the flow field of the entire flow channel, and obtain the optimal design variables of the flow channel inside the housing.

[0018] As an improvement, the specific process of simulating and optimizing the pressure on the inner side of the permeable membrane in Step 1 is as follows:

[0019] Extract the internal fluid domain of the humidifying chamber, divide the internal fluid domain of the humidifying chamber into the rotating domain of the centrifugal pump and the fixed domain other than the rotating domain, import it into the CFD software, set the range of the rotating domain, the rotational speed of the centrifugal pump, and the design variables of the centrifugal pump, and finally obtain the distribution result of the pressure on the inner side of the membrane.

[0020] Preferably, the design variables of the centrifugal pump in Step 1 include one or more of the outer diameter of the centrifugal pump, the inner diameter of the centrifugal pump, the blade shape of the centrifugal pump, the number of blades of the centrifugal pump, the blade thickness of the centrifugal pump, and the height of the centrifugal pump.

[0021] Specifically, the design variables of the flow channel inside the housing in Step 3 are one or more of the shape of the air inlet, the size of the air inlet, the outer diameter of the humidifying chamber, the shape of the air outlet, and the size of the air outlet. Taking the flow rate and velocity distribution uniformity of the gaseous water vapor at the air outlet as the target variables, determine the optimal design variables of the flow channel inside the housing according to the target variables.

[0022] Compared with the prior art, the advantages of the present invention are as follows: By providing a humidifying chamber and a centrifugal pump provided in the humidifying chamber, the peripheral wall of the humidifying chamber is composed of a permeable membrane, and the liquid in the humidifying chamber can pass through the permeable membrane under the action of the centrifugal pump, thereby generating gaseous water vapor. Thus, this humidifier uses permeable membrane humidification. This humidification technology increases the water vapor content in the air rather than small particle liquid water, belonging to a phase change humidification method and will not produce white fog; and because it is a phase change humidification method, it also needs to go through a condensation process before the humidification effect disappears. Therefore, compared with non-phase change humidification technology, the humidification technology in the present invention has a longer-lasting humidification effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1It is a schematic structural diagram of the humidifier in the embodiment of the present invention;

[0024] Figure 2 It is Figure 1 a cross-sectional view of;

[0025] Figure 3 It is Figure 1 a partial structural diagram of (the housing and the water storage tank are omitted). Specific embodiments

[0026] The present invention will be further described in detail below in conjunction with the embodiments of the drawings.

[0027] As Figures 1 to 3 shown, it is a preferred embodiment of the present invention.

[0028] The humidifier in this embodiment includes a housing 1 and a humidifying component 2 provided in the housing 1. The housing 1 has an air inlet 1a and an air outlet 1b. As Figure 1 shown, the housing 1 in this embodiment is cylindrical; there are multiple air inlets 1a, which are circumferentially spaced along the outer wall adjacent to the bottom of the housing 1, and each air inlet 1a is rectangular; the air outlet 1b is provided at the top of the housing 1, and a grille 1c is provided at the top of the housing 1, and the above-mentioned air outlet 1b is opened on the grille 1c.

[0029] As Figure 2 shown, the humidifying component 2 in this embodiment includes a humidifying chamber 21 and a centrifugal pump 22 provided in the humidifying chamber 21. The peripheral wall of the humidifying chamber 21 is composed of a permeable membrane (not shown in the figure). The inside of the humidifying chamber 21 is filled with liquid, and the liquid can pass through the permeable membrane under the action of the centrifugal pump 22, thereby generating gaseous water vapor. In order to fix the permeable membrane, the humidifying chamber 21 includes a first frame 211 and a second frame 212 arranged inside and outside. Both the first frame 211 and the second frame 212 are in a cross-shaped structure and are integrally injection-molded. The permeable membrane is provided between the first frame 211 and the second frame 212. As Figure 2 shown, the humidifying chamber 21 in this embodiment includes an annular structure composed of a permeable membrane. The humidifying chamber 21 includes a top cover 213 for closing the top of the annular structure and a bottom cover 214 for closing the bottom of the annular structure. The top cover 213, the bottom cover 214 and the permeable membrane jointly enclose a cylindrical humidifying chamber 21.

[0030] Inside the housing 1, there is a blower 3 facing the air outlet 1b. The blower 3 in this embodiment is an axial-flow blower. And inside the housing 1, there is also a motor (not shown in the figure) and a transmission shaft 4 drivingly connected to the motor. One end of the transmission shaft 4 is connected to the blower 3, and one end of the transmission shaft 4 passes through the humidification chamber 21 and is connected to the centrifugal pump 22. The transmission shaft 4 in this embodiment can be drivingly connected to a speed reduction mechanism to achieve different rotational speeds of the centrifugal pump 22 and the axial-flow blower, so as to adjust the humidification amount; the motor can be installed between the axial-flow blower and the centrifugal pump 22, or can be flexibly installed in other positions.

[0031] At the bottom of the housing 1, there is also a water storage tank 5 with an open top. The humidification chamber 21 is arranged above the water storage tank 5. At the bottom of the humidification chamber 21, there are support columns 215 (there are 3 support columns 215 in this embodiment), that is, the whole humidification chamber 21 can be suspended above the water storage tank 5 through the support of the support columns 215, and the vertical projection of the humidification chamber 21 falls into the water storage tank 5. Inside the housing 1, there is a water pumping mechanism (not shown in the figure) that can pump the water in the water storage tank 5 back into the humidification chamber 21. This water pumping mechanism can be a water pump, and its working principle is prior art and will not be elaborated here.

[0032] The working principle of the humidifier in this embodiment is as follows:

[0033] The osmotic membrane is a semi-permeable membrane, and its microscopic structure usually contains extremely small pores or specific chemical groups, allowing only small molecules (such as water molecules) to pass freely, while large molecules (such as salt ions, sugar molecules, etc.) are blocked. The passing rate of small molecules is driven by the pressure difference on both sides of the osmotic membrane. The osmotic pressure of pure water is 0. By increasing the water flux (the amount of water passing through the membrane per unit time, that is, the humidification amount) through external pressure, the external pressure is provided by the centrifugal pump. When the centrifugal pump is working, the pressure inside the osmotic membrane is much higher than the hydrostatic pressure. Under the action of the strong pressure, water molecules quickly pass through the osmotic membrane and enter the external flow channel in the form of gaseous water vapor.

[0034] The dry air is driven by the axial-flow blower, enters the internal flow channel of the housing from the air inlet, and mixes with the gaseous water vapor generated by the osmotic membrane to achieve humidification. The humidified air flows out of the humidifier from the air outlet under the action of the axial-flow blower. A small part of the liquid water condensed on the outer side of the osmotic membrane will naturally drip into the water storage tank 5, and the condensed water in the water storage tank 5 can be pumped back into the humidification chamber 21 through the water pumping mechanism to realize the recycling of condensed water.

[0035] The optimization method of the above humidifier in this embodiment includes the following steps:

[0036] Step 1: Simulate and optimize the pressure inside the osmotic membrane to obtain the design variables of the centrifugal pump corresponding to the pressure inside the osmotic membrane; and take the design variables of the centrifugal pump corresponding to the maximum pressure inside the osmotic membrane as the optimal design variables of the centrifugal pump;

[0037] The specific process of simulating and optimizing the pressure on the inner side of the permeable membrane is as follows:

[0038] Extract the internal fluid domain of the humidification chamber, and divide the internal fluid domain of the humidification chamber into the rotating domain of the centrifugal pump and the fixed domain other than the rotating domain, and import it into the CFD software (this CFD software is a software for computational fluid dynamics, which is an existing technology and will not be elaborated here). Set the range of the rotating domain, the rotational speed of the centrifugal pump, and the design variables of the centrifugal pump, and finally obtain the distribution result of the pressure on the inner side of the membrane;

[0039] The design variables of the centrifugal pump in this embodiment include the outer diameter of the centrifugal pump, the inner diameter of the centrifugal pump, the blade shape of the centrifugal pump, the number of blades of the centrifugal pump, the blade thickness of the centrifugal pump, and the height of the centrifugal pump, etc. The orthogonal design method is used to set the values and distributions of all design variables, and then simulation is carried out to determine the optimal design variables of the centrifugal pump with the goal of obtaining the maximum pressure on the inner side of the membrane;

[0040] Step 2: Perform mass transfer simulation on the permeable membrane to obtain the relationship between the mass transfer rate on the outer side of the permeable membrane and the pressure on the inner side of the membrane;

[0041] Specifically: Use the pressure on the inner side of the membrane obtained in Step 1 and the design variables of the centrifugal pump corresponding to the pressure on the inner side of the membrane to perform mass transfer simulation on the inner side of the permeable membrane to obtain the mass transfer rate on the outer side of the permeable membrane; and use the pressure on the inner side of the membrane as the design variable to simulate and obtain several groups of mass transfer rates on the outer side of the permeable membrane, and obtain the relationship between the mass transfer rate on the outer side of the permeable membrane and the pressure on the inner side of the membrane;

[0042] In this embodiment, the CFD software is also used to write UDF code and import the values such as the pressure on the inner side of the membrane, the material of the permeable membrane, and the thickness of the permeable membrane to realize the mass transfer simulation on the inner side of the permeable membrane; in addition, the relationship between the mass transfer rate on the outer side of the permeable membrane and the pressure on the inner side of the membrane can adopt existing fitting methods, which will not be elaborated here;

[0043] Step 3: Take the mass transfer rate on the outer side of the permeable membrane calculated according to the relationship in Step 2 as the boundary condition, simulate the flow field of the internal flow channel of the shell, and obtain the optimal design variables of the internal flow channel of the shell;

[0044] Specifically, in this embodiment, the fluid domain inside the housing except the humidification component is extracted, and the mass transfer rate on the outer side of the permeable membrane calculated according to the relationship in step 2 is used as the boundary condition. Similarly, the CFD software is used to simulate the flow field of the internal flow channel of the housing; taking the flow rate of the gaseous water vapor at the air outlet and the uniformity of the velocity distribution as the target variables, the optimal design variables of the internal flow channel of the housing are determined according to the target variables; the uniformity of the velocity distribution is represented by the RMS (root mean square) of the velocity values of each point evenly distributed on the air outlet. The smaller the RMS, the better the uniformity.

[0045] Since there are two target variables used when obtaining the optimal design variables of the internal flow channel of the housing, in this embodiment, it can be experimentally confirmed that both target variables, namely the flow rate of the gaseous water vapor at the air outlet and the uniformity of the velocity distribution, are relatively optimal. It is not necessary that the velocity distribution is the most uniform when the flow rate of the gaseous water vapor at the air outlet is the largest, and appropriate trade-offs can be made according to the actual results.

[0046] In this embodiment, the design variables of the internal flow channel of the housing are the shape of the air inlet, the size of the air inlet, the outer diameter of the humidification chamber, the shape of the air outlet, and the size of the air outlet. Of course, it can also include the outer diameter of the axial flow fan, the blade shape of the axial flow fan, and the number of blades of the axial flow fan, etc.

[0047] In this embodiment, through numerical simulation, the process principle is simulated to essentially improve the structural design of the humidifier to obtain a better humidification effect.

[0048] The above are only the preferred embodiments of the present invention. It should be noted that for those of ordinary skill in the art, without departing from the technical principle of the present invention, several improvements and refinements can be made, and these improvements and refinements should also be regarded as the protection scope of the present invention.

Claims

1. A humidifier, comprising a housing (1) and a humidifying component (2) provided in the housing (1), the housing (1) having an air inlet (1a) and an air outlet (1b), characterized in that: The humidifying component (2) includes a humidifying chamber (21) and a centrifugal pump (22) disposed within the humidifying chamber (21). The peripheral wall of the humidifying chamber (21) is composed of a permeable membrane. The interior of the humidifying chamber (21) is filled with a liquid, and the liquid can pass through the permeable membrane under the action of the centrifugal pump (22), thereby generating gaseous water vapor.

2. The humidifier according to claim 1, characterized in that: The humidifying chamber (21) includes a first frame (211) and a second frame (212) arranged inside and outside. The permeable membrane is disposed between the first frame (211) and the second frame (212).

3. The humidifier according to claim 1, wherein: The air outlet (1b) is disposed at the top of the housing (1), and a blower (3) is provided in the housing (1) opposite to the air outlet (1b).

4. The humidifier according to claim 3, wherein: An electric motor and a transmission shaft (4) drivingly connected to the electric motor are further provided in the housing (1). One end of the transmission shaft (4) is connected to the blower (3), and one end of the transmission shaft (4) passes through the humidifying chamber (21) and is connected to the centrifugal pump (22).

5. The humidifier according to any one of claims 1 to 4, characterized in that: A water storage tank (5) with an open top is further provided at the bottom of the housing (1). The humidifying chamber (21) is disposed above the water storage tank (5), and the vertical projection of the humidifying chamber (21) falls within the water storage tank (5).

6. The humidifier according to claim 5, characterized in that: A water pumping mechanism capable of pumping the water in the water storage tank (5) back into the humidifying chamber (21) is provided in the housing (1).

7. An optimization method for a humidifier according to any one of the above claims 1 to 6, characterized in that It includes the following steps: Step 1: Simulate and optimize the pressure on the inner side of the permeable membrane to obtain the centrifugal pump design variables corresponding to the pressure on the inner side of the membrane; and take the centrifugal pump design variables corresponding to the maximum pressure on the inner side of the membrane as the optimal design variables of the centrifugal pump. Step 2: Perform mass transfer simulation on the permeable membrane to obtain the relationship between the mass transfer rate on the outer side of the permeable membrane and the pressure on the inner side of the membrane. Specifically: Use the pressure on the inner side of the membrane and the centrifugal pump design variables corresponding to the pressure on the inner side of the membrane obtained in Step 1 to perform mass transfer simulation on the inner side of the permeable membrane to obtain the mass transfer rate on the outer side of the permeable membrane; and take the pressure on the inner side of the membrane as the design variable, simulate to obtain several groups of mass transfer rates on the outer side of the permeable membrane, and obtain the relationship between the mass transfer rate on the outer side of the permeable membrane and the pressure on the inner side of the membrane. Step 3: Take the mass transfer rate on the outer side of the permeable membrane calculated according to the relationship in Step 2 as the boundary condition, simulate the flow field of the internal flow channel of the housing, and obtain the optimal design variables of the internal flow channel of the housing.

8. The optimization method according to claim 7, wherein: The specific process of simulating and optimizing the pressure on the inner side of the permeable membrane in Step 1 is as follows: Extract the internal fluid domain of the humidifying chamber, divide the internal fluid domain of the humidifying chamber into a rotating domain of the centrifugal pump and a fixed domain other than the rotating domain, import it into CFD software, set the range of the rotating domain, the rotational speed of the centrifugal pump, and the design variables of the centrifugal pump, and finally obtain the distribution result of the pressure on the inner side of the membrane.

9. The optimization method according to claim 8, wherein: The design variables of the centrifugal pump in Step 1 include one or more of the outer diameter of the centrifugal pump, the inner diameter of the centrifugal pump, the blade shape of the centrifugal pump, the number of blades of the centrifugal pump, the blade thickness of the centrifugal pump, and the height of the centrifugal pump.

10. The optimization method according to any one of claims 7 to 9, characterized in that: In step 3, the design variables of the internal flow channel of the housing are one or more of the shape of the air inlet, the size of the air inlet, the outer diameter of the humidification chamber, the shape of the air outlet, and the size of the air outlet. Taking the flow rate of gaseous water vapor at the air outlet and the uniformity of velocity distribution as target variables, the optimal design variables of the internal flow channel of the housing are determined according to the target variables.

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