A design method for the surface of a liquid heating device for noise reduction

Abstract

The present invention discloses a design method for the surface of a liquid heating device for noise reduction, the method comprising: constructing a concave hole type micro-nano structure surface model, and determining the geometric parameters of the concave hole type micro-nano structure surface model; constructing a theoretical criterion for the concave hole type micro-nano structure surface model; determining the geometric parameter values ​​of the concave hole type micro-nano structure surface model according to the theoretical criterion for the concave hole type micro-nano structure surface model; obtaining parameter information between the concave hole type micro-nano structure and bubbles on the liquid heating surface; adjusting and processing the geometric parameters of the concave hole type micro-nano structure surface model according to the parameter information between the concave hole type micro-nano structure and bubbles on the liquid heating surface, and obtaining a concave hole type micro-nano structure device on the liquid heating surface. The present invention can achieve noise reduction from the noise source of the liquid surface heating device. As a design method for the surface of a liquid heating device for noise reduction, the present invention can be widely used in the technical field of liquid heating surface structure design.

Description

Technical Field

[0001] The invention relates to the technical field of liquid heating surface structure design, and in particular to a design method for the surface of a liquid heating device for noise reduction. Background Art

[0002] During the heating process, the liquid in the liquid heating device will generate noise due to a series of processes such as bubble nucleation, growth, departure, and rupture. The rising and collapsing process of the bubbles will emit a huge "noise", and the generated noise will interfere with the working environment or the surrounding environment. The noise reduction of some liquid heating devices in the prior art mainly focuses on improvements in noise propagation and mechanical structure, and does not fundamentally reduce the noise. In addition, additional equipment will increase the cost. Summary of the invention

[0003] In order to solve the above technical problems, an object of the present invention is to provide a design method for the surface of a liquid heating device for noise reduction, which can achieve noise reduction from the noise source of the liquid surface heating device.

[0004] The first technical solution adopted by the present invention is: a design method for the surface of a liquid heating device for noise reduction, comprising the following steps:

[0005] Constructing a concave hole type micro-nano structure surface model and determining the geometric parameters of the concave hole type micro-nano structure surface model;

[0006] According to the geometric parameters of the concave pore type micro-nano structure surface model, a theoretical criterion for the concave pore type micro-nano structure surface model is established;

[0007] Determine the geometric parameter values ​​of the concave pore type micro-nano structure surface model according to the theoretical criterion of the concave pore type micro-nano structure surface model;

[0008] According to the geometric parameter values ​​of the concave pore type micro-nano structure surface model, the parameter information between the concave pore type micro-nano structure and the bubbles on the liquid heating surface is obtained;

[0009] According to the parameter information between the concave hole type micro-nano structure and the bubbles on the liquid heating surface, the geometric parameters of the concave hole type micro-nano structure surface model are adjusted to obtain the liquid heating surface concave hole type micro-nano structure device.

[0010] Furthermore, the geometric parameters of the surface model of the concave pore type micro-nanostructure include the depth of the concave pores of the concave pore type micro-nanostructure, the diameter of a single surface concave pore of the concave pore type micro-nanostructure, and the distance between two concave pores of the concave pore type micro-nanostructure.

[0011] Furthermore, the theoretical criteria of the concave pore type micro-nano structure surface model include the numerical relationship between the solid-liquid contact area ratio fraction of the concave pore type micro-nano structure surface and the bubble generation rate and the bubble detachment diameter value.

[0012] Furthermore, the numerical relationship between the solid-liquid contact area ratio fraction of the concave pore-type micro-nanostructure surface and the bubble generation rate is expressed as follows:

[0013] R=K×(1-f) n

[0014] In the above formula, R represents the bubble generation rate, K and n represent constants, and f represents the solid-liquid contact area ratio fraction of the concave pore type micro-nanostructure surface.

[0015] Further, the expression of the bubble detachment diameter value is:

[0016]

[0017] In the above formula, D represents the diameter of the bubble, p0 represents the atmospheric pressure, and p l represents the internal pressure of the bubble, σ represents the surface tension of the liquid, and ρ l represents the gas density inside the bubble, ρ v represents the liquid density, and r represents the diameter of a single surface concave pore of the concave pore type micro-nanostructure.

[0018] Furthermore, the parameter information between the concave pore-type micro-nanostructure on the liquid heating surface and the bubbles includes the bubble detachment diameter value and the bubble generation rate.

[0019] Further, the step of adjusting the geometric parameters of the concave hole type micro-nano structure surface model according to the parameter information between the concave hole type micro-nano structure on the liquid heating surface and the bubbles to obtain the concave hole type micro-nano structure device on the liquid heating surface specifically includes:

[0020] The bubble noise on the liquid heating surface is obtained based on the parameter information between the concave pore micro-nanostructure and the bubbles on the liquid heating surface;

[0021] Determine whether the bubble noise on the liquid heating surface meets the preset noise requirements;

[0022] If not, the steps of determining the geometric parameter values ​​of the concave hole type micro-nano structure surface model and obtaining parameter information between the concave hole type micro-nano structure and the bubbles on the liquid heating surface are repeated;

[0023] Until the preset noise requirement is met, a liquid heating surface concave hole type micro-nano structure device is obtained.

[0024] Further, the expression of the bubble noise on the liquid heating surface is:

[0025]

[0026] In the above formula, SPL represents the sound pressure level of bubble noise on the heated liquid surface, c, n, and m represent constants, σ ​​represents the surface tension of the liquid, D represents the value of the bubble detachment diameter, and ρ represents the density of the heated liquid.

[0027] Furthermore, the geometric parameters of the concave hole type micro-nano structure surface model satisfy a preset geometric parameter construction relationship, and the expression of the preset geometric parameter construction relationship is:

[0028]

[0029] In the above formula, A represents a parameter, d represents the distance between two concave holes of the concave hole type micro-nanostructure, and r represents the diameter of a single surface concave hole of the concave hole type micro-nanostructure.

[0030] The beneficial effect of the method of the present invention is as follows: the present invention determines the theoretical criterion of the concave pore type micro-nano structure surface model based on the geometric parameters of the concave pore type micro-nano structure surface model, further determines the geometric parameter value of the concave pore type micro-nano structure surface model based on the theoretical criterion of the concave pore type micro-nano structure surface model, and finally determines the parameter information between the concave pore type micro-nano structure and the bubbles on the liquid heating surface, considers the generation rate of bubbles on the heating surface and the detachment diameter of the bubbles on the basis of the designed structural parameters, and then adjusts the geometric parameters of the concave pore type micro-nano structure surface model based on the parameter information between the concave pore type micro-nano structure and the bubbles on the liquid heating surface, and performs noise reduction in principle during the liquid heating process, fully considers the influence of factors such as the bubble nucleation density, bubble detachment diameter and bubble detachment frequency, and realizes noise reduction from the noise source of the liquid surface heating device. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 is a flow chart of steps of a method for designing a surface of a liquid heating device for noise reduction according to the present invention;

[0032] Figure 2 is a two-dimensional schematic diagram of a micro-nanostructure of a heating surface provided by a specific embodiment of the present invention;

[0033] Figure 3 is a three-dimensional schematic diagram of a micro-nano structure of a heating surface provided by a specific embodiment of the present invention;

[0034] Figure 4 It is a schematic diagram of the flow chart of the design of a liquid heating surface concave hole type micro-nano structure device provided by a specific embodiment of the present invention. DETAILED DESCRIPTION

[0035] The present invention is further described in detail below in conjunction with the accompanying drawings and specific embodiments. The step numbers in the following embodiments are only provided for the convenience of explanation and description, and the order between the steps is not limited in any way. The execution order of each step in the embodiment can be adaptively adjusted according to the understanding of those skilled in the art.

[0036] During the heating process, the liquid in the liquid heating device will generate noise due to a series of processes such as bubble nucleation, growth, departure, and rupture. The rising and collapsing process of the bubbles will emit a huge "noise", and the generated noise will interfere with the working environment or the surrounding environment. In real life, the background noise level in a general quiet environment is about 30dB to 40dB. The sound generated by the movement of bubbles in the process of heating the liquid in the liquid heating device is usually between 50dB and 80dB. In order to improve the comfort of the working environment, meet the noise limit standards and meet the needs of users, the noise of the liquid heating device needs to be controlled and reduced.

[0037] At present, the noise reduction of some liquid heating devices is mainly improved in terms of noise propagation and mechanical structure, but the noise is not fundamentally reduced. Therefore, it is necessary to design a micro-nanostructure surface that can reasonably control the number of bubbles generated, the bubble detachment diameter, and the bubble detachment frequency to reduce noise.

[0038] Based on this, an embodiment of the present invention proposes a design method for the surface of a liquid heating device for noise reduction. This method uses the micro-nano structure of the heating surface to control the number of bubble nucleations and the bubble detachment diameter, thereby controlling the sound waves generated by the bursting of the bubbles during the rising process. The purpose is to fundamentally solve the problem of reducing noise generation.

[0039] Reference Figure 1 and Figure 4 The present invention provides a method for designing the surface of a liquid heating device for noise reduction, the method comprising the following steps:

[0040] S1. constructing a concave hole type micro-nano structure surface model and determining geometric parameters of the concave hole type micro-nano structure surface model;

[0041] Specifically, the geometric parameters of the concave pore type micro-nanostructure surface model include the concave pore depth of the concave pore type micro-nanostructure, the diameter of a single surface concave pore of the concave pore type micro-nanostructure, and the distance between two concave pores of the concave pore type micro-nanostructure.

[0042] In the embodiment of the present invention, Figure 2 and Figure 3 As shown, firstly, a concave hole type micro-nano structure surface model is established, and the geometric parameters of the micro-nano structure model are set, the geometric parameters including the concave hole depth h, the diameter r of a single surface concave hole, and the distance d between two concave holes.

[0043] S2. Constructing a theoretical criterion for a concave pore type micro-nano structure surface model according to geometric parameters of the concave pore type micro-nano structure surface model;

[0044] Specifically, the theoretical criteria of the concave pore type micro-nano structure surface model include the numerical relationship between the solid-liquid contact area ratio fraction of the concave pore type micro-nano structure surface and the bubble generation rate and the bubble detachment diameter value.

[0045] In the embodiment of the present invention, based on the required theoretical criteria, the numerical relationship between the solid-liquid contact area ratio fraction of the designed micro-nanostructure surface and the bubble nucleation rate, i.e., bubble generation rate, bubble detachment diameter and bubble detachment diameter is established.

[0046] S3, determining the geometric parameter values ​​of the concave hole type micro-nano structure surface model according to the theoretical criterion of the concave hole type micro-nano structure surface model;

[0047] Specifically, the parameters between the micro-nanostructures on the heating surface and the bubbles include the bubble generation rate, the solid-liquid surface contact area defined by the Cassie model, and the micro-nanostructure array spacing, wherein the specific formula for the relationship between the bubble generation rate on the heating surface and the solid-liquid contact area is:

[0048] R=K×(1-f) n

[0049] In the above formula, R represents the bubble generation rate, K and n represent constants, and f represents the solid-liquid contact area ratio fraction of the concave pore type micro-nanostructure surface.

[0050] It should be noted that the relationship between the solid-liquid contact area ratio and the surface parameters of the invented micro-nanostructure is:

[0051]

[0052] In the above formula, f represents the solid-liquid contact area ratio fraction of the concave pore type micro-nanostructure surface, d represents the distance between two concave pores of the concave pore type micro-nanostructure, and r represents the diameter of a single surface concave pore of the concave pore type micro-nanostructure.

[0053] Furthermore, it should be noted that the geometric parameters of the micro-nanostructure of the heating surface must satisfy the following relationship, which is expressed as follows:

[0054]

[0055] In the above formula, A represents a parameter, d represents the distance between two concave holes of the concave hole type micro-nanostructure, and r represents the diameter of a single surface concave hole of the concave hole type micro-nanostructure.

[0056] S4, obtaining parameter information between the concave pore type micro-nano structure and the bubbles on the liquid heating surface according to the geometric parameter values ​​of the concave pore type micro-nano structure surface model;

[0057] Specifically, the parameter information between the concave pore-type micro-nanostructure on the liquid heating surface and the bubbles includes the bubble detachment diameter value and the bubble generation rate.

[0058] In the embodiment of the present invention, the calculation formula between the bubble detachment diameter and the parameters of the designed micro-concave hole structure is:

[0059]

[0060] In the above formula, D represents the diameter of the bubble, p0 represents the atmospheric pressure, and ρ l represents the internal pressure of the bubble, σ represents the surface tension of the liquid, and ρ l represents the gas density inside the bubble, ρ v represents the liquid density, and r represents the diameter of a single surface concave pore of the concave pore type micro-nanostructure.

[0061] S5. According to the parameter information between the concave hole type micro-nano structure and the bubbles on the liquid heating surface, the geometric parameters of the concave hole type micro-nano structure surface model are adjusted to obtain the liquid heating surface concave hole type micro-nano structure device.

[0062] Specifically, the bubble noise on the liquid heating surface is obtained based on the parameter information between the concave hole type micro-nano structure on the liquid heating surface and the bubbles; it is determined whether the bubble noise on the liquid heating surface meets the preset noise requirements; if not, the steps of determining the geometric parameter values ​​of the concave hole type micro-nano structure surface model and obtaining the parameter information between the concave hole type micro-nano structure on the liquid heating surface and the bubbles are repeated; until the preset noise requirements are met, a liquid heating surface concave hole type micro-nano structure device is obtained.

[0063] In an embodiment of the present invention, a micro-nano structure is pre-designed based on the established numerical relationship, the structural parameter values ​​of the designed micro-nano structure surface are calculated, and the bubble generation rate and bubble detachment diameter are calculated. If the requirements are met, the next step is to determine whether the noise generated is reduced. Finally, the noise generated by the heating process is detected based on the structural parameters of the pre-designed concave hole micro-nano structure surface.

[0064] The calculation formula between bubble behavior and noise is:

[0065]

[0066] In the above formula, SPL represents the sound pressure level of bubble noise on the heated liquid surface, c, n, and m represent constants, σ ​​represents the surface tension of the liquid, D represents the value of the bubble detachment diameter, and ρ represents the density of the heated liquid.

[0067] Finally, it is determined whether the calculated bubble detachment diameter and bubble detachment frequency meet the requirements of the designed noise reduction surface, and the proportional relationship between d and r is adjusted to achieve the purpose of noise reduction. The embodiment of the present invention is applicable to the surface structure noise reduction method for different liquid noise reduction.

[0068] In summary, the embodiment of the present invention proposes the relationship between the micro-nano structure of the liquid heating surface and the bubble behavior based on the principle of noise generation by liquid heating, which can be used as a theoretical criterion for controlling the noise level by regulating the structure of the heating surface. Considering the solid-liquid contact area ratio fraction of the microscopic contact form between the bubble and the microstructure surface, the generation rate of bubbles on the heating surface and the bubble detachment diameter are considered on the basis of the designed structural parameters. The design process is more intuitive and the method is easier to master. Compared with the prior art, the embodiment of the present invention reduces the noise in the liquid heating process in principle, and fully considers the influence of factors such as the bubble nucleation density, bubble detachment diameter and bubble detachment frequency. Through calculation and design, a surface micro-nano structure that is beneficial to the noise of the heating process is invented to achieve the desired effect of the embodiment of the present invention.

[0069] Further, the implementation process of the present invention is described with specific example data:

[0070] Liquid water is taken as an example to illustrate this design scheme, where the pressure difference at the solid-liquid interface is 1 kPa and the surface tension of the liquid is σ=0.0728 N / m.

[0071] According to the requirements of the designed surface micro-nano structure parameters, the nucleation rate of bubbles, the detachment diameter and detachment frequency of bubbles, and by constructing an expression of the relationship based on the preset geometric parameters, the range of d can be obtained as 2r < d < 3r, and the range of the solid-liquid contact area proportion fraction f is 0 < f < 1. When f approaches 1, the surface structure shows hydrophilicity, which can enhance the influence of the surface structure on bubbles. From the above two ranges, the values of r and d can be obtained. In this example, r = 100 nm and d = 250 nm are taken respectively. After determining r and d, the solid-liquid contact area proportion fraction f defined by the Cassie model is calculated, and then the generation rate of bubbles on the heating surface is calculated according to the expression of the numerical relationship between the solid-liquid contact area proportion fraction of the concave-hole micro-nano structure surface and the bubble generation rate. From the expression of the numerical relationship between the solid-liquid contact area proportion fraction of the concave-hole micro-nano structure surface and the bubble generation rate, it can be obtained that when the solid-liquid contact area proportion fraction is small, the bubble generation rate is high; as the solid-liquid contact area proportion fraction increases, the bubble generation rate gradually decreases. From the above description, when the bubble generation rate decreases at this time, the parameter A in the expression of the relationship constructed by the preset geometric parameters is also satisfied at this time, and within the specified range, the detachment frequency of bubbles can be significantly enhanced, resulting in a decrease in the detachment diameter of bubbles. According to the expression of the bubble noise on the liquid heating surface, it can be obtained that a larger bubble detachment diameter will generate greater noise, because a larger bubble will cause stronger liquid vibration and impact when detaching.

[0072] The above is a specific description of the preferred embodiment of the present invention, but the present invention is not limited to the described embodiment. Those skilled in the art can make various equivalent deformations or substitutions without departing from the spirit of the present invention, and these equivalent deformations or substitutions are all included in the scope defined by the claims of this application.

Claims

1. A method for designing the surface of a liquid heating device for noise reduction, characterized in that: The following steps are involved: Constructing a concave hole type micro-nano structure surface model and determining the geometric parameters of the concave hole type micro-nano structure surface model; The geometric parameters of the concave hole type micro-nano structure surface model include the concave hole depth of the concave hole type micro-nano structure, the diameter of a single surface concave hole of the concave hole type micro-nano structure, and the distance between two concave holes of the concave hole type micro-nano structure; According to the geometric parameters of the concave pore type micro-nano structure surface model, a theoretical criterion for the concave pore type micro-nano structure surface model is established; The theoretical criteria of the concave pore type micro-nano structure surface model include the numerical relationship between the solid-liquid contact area ratio fraction of the concave pore type micro-nano structure surface and the bubble generation rate and the bubble detachment diameter value; The expression for the numerical relationship between the solid-liquid contact area ratio fraction of the concave pore-type micro-nanostructure surface and the bubble generation rate is: ； In the above formula, represents the bubble generation rate, represents a constant, It represents the solid-liquid contact area ratio of the concave pore micro-nanostructure surface; Among them, the relationship between the solid-liquid contact area ratio and the concave pore micro-nanostructure surface is: ； In the above formula, represents the solid-liquid contact area ratio of the concave micro-nanostructure surface, Represents the distance between two concave holes in the concave hole type micro-nanostructure, Represents the diameter of a single surface concave hole of the concave-hole type micro-nanostructure; The expression of the bubble detachment diameter value is: ； In the above formula, Indicates the bubble detachment diameter value. represents the atmospheric pressure, represents the pressure inside the bubble, is the surface tension of the liquid, represents the gas density inside the bubble, represents the density of the liquid, Represents the diameter of a single surface concave hole of the concave-hole type micro-nanostructure; Determine the geometric parameter values ​​of the concave pore type micro-nano structure surface model according to the theoretical criterion of the concave pore type micro-nano structure surface model; The parameter information between the concave pore-type micro-nanostructure on the liquid heating surface and the bubbles includes the bubble detachment diameter value and the bubble generation rate; According to the geometric parameter values ​​of the concave pore type micro-nano structure surface model, the parameter information between the concave pore type micro-nano structure and the bubbles on the liquid heating surface is obtained; The bubble noise on the liquid heating surface is obtained based on the parameter information between the concave pore micro-nanostructure and the bubbles on the liquid heating surface; Determine whether the bubble noise on the liquid heating surface meets the preset noise requirements; The expression of the bubble noise on the liquid heating surface is: ； In the above formula, Indicates the sound pressure level of bubble noise on the surface of liquid heating, represents a constant, is the surface tension of the liquid, Indicates the bubble detachment diameter value. Indicates the density of the heated liquid; If not, the steps of determining the geometric parameter values ​​of the concave hole type micro-nano structure surface model and obtaining parameter information between the concave hole type micro-nano structure and the bubbles on the liquid heating surface are repeated; The geometric parameters of the concave hole type micro-nano structure surface model satisfy the preset geometric parameter construction relationship, and the expression of the preset geometric parameter construction relationship is: ； In the above formula, Indicates the parameters, Represents the distance between two concave holes in the concave hole type micro-nanostructure, Represents the diameter of a single surface concave hole of the concave-hole type micro-nanostructure; Until the preset noise requirement is met, a liquid heating surface concave hole type micro-nano structure device is obtained.

Images