Perforated plate surface structure for reducing cavitation effect of balance flow meter

Abstract

The utility model relates to a perforated plate surface structure for reducing the cavitation effect of a balance flow meter, and belongs to the technical field of flow meters. Throttling holes are formed in the plate body, the front face of the plate body is a fluid incoming face, and the back face of the plate body is a fluid outgoing face; a plurality of fine grooves are formed in the back face of the plate body and the hole walls of the throttling holes. According to the utility model, the cavitation phenomenon can be inhibited; the plurality of micro cylindrical grooves form a super-hydrophilic microstructure which can adsorb liquid and form a layer of thin film, so that bubbles are prevented from being formed in pore channels of the porous plate. The super-hydrophilicity can effectively reduce the surface tension of the liquid and reduce the generation and development of bubbles, thereby inhibiting the cavitation phenomenon.

Description

Technical Field

[0001] The utility model relates to the technical field of flowmeters, in particular to a porous plate surface structure for reducing the cavitation effect of a balanced flowmeter. Background Art

[0002] Balanced flowmeters are widely used in the measurement of various fluids due to their advantages such as accurate measurement and reliable operation, especially in the measurement of cryogenic fluids, including liquefied natural gas (LNG) and liquid nitrogen. Balanced flowmeters calculate flow through pressure difference, but cryogenic fluids have a low vaporization point, and changes in pressure can easily cause cavitation, affecting the overall performance of the flowmeter.

[0003] Cavitation is when the pressure in a liquid drops below the saturation pressure and the gas or vapor in the liquid begins to form bubbles or steam bubbles. Cavitation is an important phenomenon in fluid dynamics and thermodynamics, which can have a negative impact on fluid flow and flow measurement. During the flow of a liquid, pressure changes occur when the liquid passes through a flow channel or pipe. If the pressure drops below the saturation pressure of the liquid, the gas or vapor in the liquid condenses to form bubbles. These bubbles will hinder the normal flow of the fluid and cause the performance of the flow meter to deteriorate. For example, the unevenness of the fluid flow caused by bubbles increases the measurement error, resulting in a decrease in the measurement accuracy and metering precision of the flow meter; and the bubbles generated by cavitation will increase the friction resistance of the fluid when passing through the hole, resulting in additional pressure loss; and the energy generated when the bubbles burst will damage the structure of the flow meter.

[0004] Scholars have conducted in-depth research on this phenomenon and found that the main reason for its occurrence during pipeline transportation is the rapid pressure drop during the high-speed flow of the liquid, that is, the pressure loss when passing through the porous plate is too large. Feng Zhao et al. proposed a new type of two-stage perforated plate structure flowmeter. Compared with the single-stage porous plate, the two-stage perforated porous plate has a smaller pressure drop and a larger horizontal outflow coefficient. Aneeq Raheem et al. studied the influence of the parameters of the porous plate on the cavitation phenomenon. After research, it was found that the pressure coefficient decays with the fourth power of the equivalent diameter ratio. In existing studies, the influence of chamfers on the performance of flowmeters was studied, and it was found that the front chamfer was 60° and the rear chamfer was in the range of 45° to 60°. It has a good improvement in reducing the pressure loss of the flowmeter; at the same time, the structural parameters of the swirl flowmeter were optimized, and the optimized swirl flowmeter reduced the pressure loss by 47.2% compared with the original version; and the structural parameters of the porous plate, such as the number of throttling holes, the thickness of the orifice plate, and the cone angle, were studied. By changing its parameters, it is also helpful to reduce the pressure loss of the flowmeter.

[0005] At present, the research on cavitation effect in balanced flowmeters is mainly focused on optimizing the porous plate structure and improving the pressure distribution, but these methods have limited effects on suppressing cavitation phenomena; they have not effectively suppressed the cavitation effect from the source. Utility Model Content

[0006] In order to solve the above technical problems, the utility model adopts the following technical solutions:

[0007] A porous plate surface structure for reducing the cavitation effect of a balanced flowmeter comprises a plate body, wherein a throttling hole is provided on the plate body, wherein the front side of the plate body is a fluid incoming side, and the back side of the plate body is a fluid outgoing side; and a plurality of fine grooves are provided on the back side of the plate body and the wall of the throttling hole.

[0008] Furthermore, the micro groove is a micro cylindrical groove.

[0009] Furthermore, a plurality of the micro-cylindrical grooves are distributed in an array on the back side of the plate body and on the wall of the throttling hole.

[0010] Furthermore, the plurality of the micro-cylindrical grooves on the back side of the plate body are distributed in an array; and the plurality of the micro-cylindrical grooves on the wall of the throttling hole are distributed in an array.

[0011] Furthermore, the throttle hole includes a first throttle hole and a plurality of second throttle holes, the first throttle hole is arranged at the center of the plate body, and the plurality of second throttle holes are evenly distributed on the plate body.

[0012] Furthermore, four second throttling holes are provided, and the four second throttling holes are evenly distributed on the plate body.

[0013] Furthermore, the radius of the second throttle hole is smaller than the radius of the first throttle hole.

[0014] Beneficial effects:

[0015] The utility model can further improve the performance of the porous plate flowmeter on the basis of the original porous plate;

[0016] The utility model can inhibit cavitation: a number of fine cylindrical grooves form a super-hydrophilic microstructure that can absorb liquid and form a thin film to prevent bubbles from forming in the porous plate channels. This super-hydrophilicity can effectively reduce the surface tension of the liquid, reduce the generation and development of bubbles, and thus inhibit the occurrence of cavitation;

[0017] The utility model can improve the stability of liquid flow: adding super-hydrophilic microstructures can increase the wettability of the wall surface in the throttling hole of the porous plate, so that the liquid is more evenly distributed in the pores;

[0018] The utility model can be applied to various application scenarios where accurate measurement of fluid flow is required. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a cross-sectional view of the surface structure of the porous plate of the utility model;

[0020] Figure 2 It is an enlarged view of the A part of the utility model;

[0021] Figure 3 It is an enlarged view of B of the utility model;

[0022] Figure 4 This is a schematic diagram of the structure of the utility model in which the micro cylindrical grooves are distributed in an array;

[0023] Figure 5 It is a structural schematic diagram of the utility model;

[0024] Among them, 1. plate body; 2. micro cylindrical groove. DETAILED DESCRIPTION

[0025] Example 1

[0026] refer to Figure 1-Figure 5 A porous plate surface structure for reducing the cavitation effect of a balanced flowmeter includes a plate body 1, on which a throttling hole is opened, wherein the front side of the plate body 1 is a fluid incoming side, and the back side of the plate body 1 is a fluid outgoing side; a plurality of fine grooves are arranged on the back side of the plate body 1 and the wall of the throttling hole.

[0027] Preferably, the fine groove is a fine cylindrical groove 2.

[0028] In this embodiment, the diameter of the fine cylindrical groove is 10-15 microns.

[0029] Preferably, the plurality of fine cylindrical grooves 2 on the back side of the plate body are distributed in an array; the plurality of fine cylindrical grooves 2 on the wall of the throttling hole are distributed in an array.

[0030] In this embodiment, the fine cylindrical grooves 2 are arranged on the back side of the plate body 1 and on the wall of the throttling hole by masked film electrolysis.

[0031] Preferably, the throttle hole includes a first throttle hole and a plurality of second throttle holes, the first throttle hole is arranged at the center of the plate body 1 , and the plurality of second throttle holes are evenly distributed on the plate body 1 .

[0032] Preferably, four second throttling holes are provided, and the four second throttling holes are evenly distributed on the plate body 1 .

[0033] Preferably, the radius of the second throttle hole is smaller than the radius of the first throttle hole.

[0034] Working principle: By setting fine cylindrical grooves 2 on the surface of the porous plate, the wall of the channel and the surface behind the plate are changed to achieve super-wetting effect on the working fluid, thereby reducing the probability of cavitation when the fluid passes through the porous plate. At the same time, super-wetting can improve the flow wall conditions, smooth pressure changes, further inhibit the growth and collapse of bubbles, and effectively reduce the impact of cavitation effect.

[0035] Currently, balanced flow meters are widely used in the measurement of low-temperature, cavitation-prone fluids such as LNG. The existing balanced flow meter structure design has limited effect in suppressing cavitation. The utility model can significantly reduce the cavitation effect, achieving the goals of saving costs and improving economic efficiency.

[0036] The above description is only a preferred embodiment of the present invention and does not limit the technical scope of the present invention. Therefore, any slight modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention still fall within the scope of the technical solution of the present invention.

Claims

1. A porous plate surface structure for reducing the cavitation effect of a balanced flowmeter, comprising a plate body, wherein a throttling hole is provided on the plate body, wherein: The front side of the plate body is the fluid incoming side, and the back side of the plate body is the fluid outgoing side. The plate body is characterized in that a plurality of fine grooves are provided on the back side of the plate body and the wall of the throttling hole.

2. A porous plate surface structure for reducing cavitation effect of a balanced flowmeter as claimed in claim 1, characterized in that: The micro grooves are micro cylindrical grooves.

3. A porous plate surface structure for reducing cavitation effect of a balanced flowmeter as claimed in claim 2, characterized in that: The plurality of micro-cylindrical grooves on the back side of the plate body are distributed in an array; the plurality of micro-cylindrical grooves on the wall of the throttling hole are distributed in an array.

4. A porous plate surface structure for reducing cavitation effect of a balanced flowmeter as claimed in claim 3, characterized in that: The throttle hole includes a first throttle hole and a plurality of second throttle holes, the first throttle hole is arranged at the center of the plate body, and the plurality of second throttle holes are evenly distributed on the plate body.

5. A porous plate surface structure for reducing cavitation effect of a balanced flowmeter as claimed in claim 4, characterized in that: There are four second throttling holes, and the four second throttling holes are evenly distributed on the plate body.

6. A porous plate surface structure for reducing cavitation effect of a balanced flowmeter as claimed in claim 5, characterized in that: The radius of the second throttle hole is smaller than the radius of the first throttle hole.

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