A structural optimization design method for energy-saving butterfly valve

Abstract

The present invention proposes a method for optimizing the design of an energy-saving butterfly valve structure, which relates to the technical field of computer-aided three-dimensional modeling. The energy-saving butterfly valve is three-dimensionally modeled to create a valve body and a valve plate of the energy-saving valve. A fluid channel and a fluid domain that penetrate the valve body are created inside the valve body. The fluid domain includes a curved area located at the center of the inner surface and a plane area located on both sides of the center. The sealing parameters of the sealing structure of the valve plate periphery are designed to ensure that the actual sealing pressure of the sealing structure is within a limited range. The three-dimensional model of the energy-saving butterfly valve is fluid simulated to optimize the curved area and plane area parameters of the fluid domain. The energy-saving butterfly valve structure designed by optimization can extend its service life, reduce the amount of sealant used, and reduce costs while ensuring the sealing performance.

Description

Technical Field

[0001] The invention relates to the technical field of computer-assisted design of butterfly valve structures, and in particular to an energy-saving butterfly valve structure optimization design method. Background Art

[0002] Valves are common control components in pipeline fluid delivery systems, which play the role of opening and closing, controlling flow direction, and adjusting the parameters of the conveying medium. The valve mainly includes a valve body, a valve seat, a valve core, and a drive assembly. The valve seat is set inside the valve body to support the fully closed position of the valve core and form a sealing pair. The drive assembly is used to control the opening and closing of the valve core. Common valve types include ball valves, butterfly valves, diaphragm valves, gate valves, check valves, etc. Among them, the butterfly valve, that is, the valve core is a circular butterfly plate, which is opened and closed by rotating with the valve stem as the axis.

[0003] The most important technical performance indicator of a valve is its sealing performance, which refers to the ability of each sealing part of the valve to prevent leakage of the medium. The contact between the valve seat and the valve core is one of the sealing parts of the valve. The contact between the valve seat and the valve core of an ordinary butterfly valve is generally a one-way sealing structure, which has a sealing effect when under positive pressure, but is prone to medium leakage when under reverse pressure.

[0004] In the field of valve design, especially centerline clamp, clamp and lug fire butterfly valves, among which the centerline fire butterfly valves with valve body cavity sealing surface sprayed and valve plate rubber coated, the existing valve body sealing pair designs mainly have two shapes:

[0005] 1. Inner cavity

[0006] The diameter sealing belt adopts a cylindrical plane sealing surface shape.

[0007] 2. The inner cavity diameter sealing belt adopts a spherical shape; the valve plate also has two types of sealing

[0008] form:

[0009] 1. The valve plate adopts the combined shape design of end cut and single waterline.

[0010] 2. The valve plate adopts a spherical shape design.

[0011] The sealing of the center line butterfly valve is mainly achieved by the interference fit between the butterfly plate and the rubber valve seat, relying on the elasticity of the rubber. The above technology is the design structure most commonly used by domestic center line rubber sealing butterfly valve manufacturers. It has a simple structure and low product cost. However, due to the high sealing requirements of the butterfly valve, the sealing pressure is more than twice the design pressure. In particular, the international UL / FM fire butterfly valve certification requires strict high-pressure life sealing tests. In the sealing pair design of the valve plate and the valve body in the prior art, the interference is increased, especially at the ends of the upper and lower shaft holes of the valve plate to ensure the sealing in the high-pressure test. In actual use and certification tests, leakage is prone to occur at the ends of the upper and lower shafts of the valve plate and leakage caused by fatigue aging of the rubber seals on both sides, thereby reducing the sealing effect of the butterfly valve and shortening the service life of the butterfly valve product.

[0012] At present, butterfly valves are used to adjust flow, cut off or connect fluids in pipelines with different media. They are mainly composed of valve plate assembly, valve body assembly and bottom cover assembly. The seal between the sealing surface of the valve plate and the valve seat is achieved by the torque of the transmission device to press the valve plate against the valve seat. In the positive flow state, the higher the medium pressure, the tighter the seal is squeezed. When the flow channel medium flows in reverse, as the medium pressure increases, the unit positive pressure between the valve plate and the valve seat is less than the medium pressure, and the seal begins to leak. Due to the limitation of structural conditions, this structure is not suitable for valves with a diameter below DN100, because the overall structure of the valve plate is too thick and the flow resistance is large.

[0013] In summary, the current center line fire butterfly valve has certain defects in the design of the sealing pair of the valve plate and valve body, mainly because the sealing interference design of the valve plate rubber is large, resulting in insufficient life of the valve plate. The existing butterfly valve has high production costs, is difficult to repair leakage, the sealing structure is easy to wear, and has a large opening torque. Summary of the invention

[0014] In order to solve the above technical problems, the present invention proposes an energy-saving butterfly valve structure optimization design method, comprising the following steps:

[0015] S1. Perform three-dimensional modeling on the energy-saving butterfly valve, create the valve body and valve plate of the energy-saving valve, and create a fluid channel and a fluid domain that penetrates the valve body inside the valve body. The fluid domain includes a curved surface area located at the center of the inner surface and a flat surface area located on both sides of the center;

[0016] S2. Design the sealing parameters of the sealing structure around the valve plate to ensure that the actual sealing pressure of the sealing structure is within the specified range;

[0017] S3. Perform fluid simulation on the three-dimensional model of the energy-saving butterfly valve to optimize the curved surface area and plane area parameters of the fluid domain.

[0018] Furthermore, the actual sealing pressure q satisfies the range defined by the following formula:

[0019] qM ﹤q﹤q D ;

[0020] ;

[0021] Where: The minimum sealing pressure is q M , the maximum sealing pressure is q D , C and K are constants, determined based on empirical values, P is the nominal pressure of the butterfly valve, b i is the thickness of the i-th sealing ring, and N is the number of sealing rings.

[0022] Furthermore, in the step S2, a plurality of sealing rings are directly arranged on the outer periphery of the valve plate along the radial direction, and the plurality of sealing rings form the sealing structure.

[0023] Furthermore, in step S2, multiple grooves are created on the periphery of the valve plate, and multiple sealing rings are arranged on the grooves. The radial height of the multiple sealing rings is higher than the depth of the grooves. The sealing rings protrude outward from the outer peripheral surface of the valve plate, and the multiple sealing rings form a sealing structure.

[0024] Furthermore, on the cross section of the valve plate, the distance between the sealing ring and the central axis of the valve plate is the height of the sealing ring, and the plurality of sealing rings form a petal-shaped sealing ring, the sealing ring in the middle area of ​​the petal-shaped sealing ring is high, and the sealing ring in the peripheral area is low.

[0025] Furthermore, the peripheral sealing surface of the sealing structure matches the curved surface area of ​​the valve body, and the peripheral sealing surface is a sealing surface formed by a line connecting the highest points of the sealing structure.

[0026] Further, the valve body fluid domain includes a curved surface area located at the center of the inner surface and a flat surface area located on both sides of the center;

[0027] Calculate the flow coefficient :

[0028] ;

[0029] Where S is the surface area of ​​the plane area, Q is the volume flow rate of the plane area, ρ is the fluid density, P 1 is the pressure before the valve, P 2 is the pressure after the valve;

[0030] Calculate the flow resistance coefficient K:

[0031] ;

[0032] in, is the pressure difference between the inlet and outlet of the curved surface area, v is the average velocity of the fluid curved surface area, is the curvature of the surface area.

[0033] Furthermore, the curved area is symmetrical about the virtual center plane of the valve body, and the thickness of the curved area gradually and continuously increases from the center of the valve body to both sides; the surface connection between the plane area and the curved area is a smooth transition or a cross-sectional transition.

[0034] Furthermore, the sealing structure includes a top sealing surface, a middle sealing surface and a bottom sealing surface; the valve body includes a top, a middle and a bottom; the top sealing surface, the middle sealing surface and the bottom sealing surface respectively cooperate with the top, the middle and the bottom of the curved surface area of ​​the valve body; the top sealing surface and the bottom sealing surface refer to areas that are respectively sealed with the top and the bottom of the valve body when the valve plate is open or closed, and the middle sealing surface refers to an area that is sealed with the middle of the curved surface area when the valve plate is closed.

[0035] Furthermore, a plurality of sealing rings are arranged along the axial direction on the outer periphery of the valve plate body, and the sealing structure is formed by the plurality of sealing rings. When the cross section of the valve plate body is viewed along the radial direction of the valve plate body, the highest point connection line of the plurality of sealing rings forms an outer peripheral sealing surface of the sealing structure, and the outer peripheral sealing surface matches the curved surface area of ​​the valve body.

[0036] Furthermore, the first outer surface and the second outer surface on both sides of the valve plate body are respectively coated with sealing materials to form a first sealing layer and a second sealing layer, and the sealing structure is composed of the multiple sealing rings, the first sealing layer and the second sealing layer.

[0037] Furthermore, on the cross section of the valve plate, the distance between the sealing ring and the central axis of the valve plate is the height of the sealing ring. When the number of the sealing rings is an odd number, the sealing ring in the middle has the highest height. The heights of the plurality of sealing rings gradually decrease from the middle to both sides. The sealing structure formed by the plurality of sealing rings is a petal shape with a high middle area and a low peripheral area. The highest points of the plurality of sealing rings are connected to form a peripheral sealing surface of the sealing structure, and the peripheral sealing surface cooperates with the curved area of ​​the valve body.

[0038] Furthermore, on the cross section of the valve plate, the distance between the sealing ring and the central axis of the valve plate is the height of the sealing ring. When the number of the sealing rings is an even number, the two sealing rings in the middle have the highest height. The heights of the multiple sealing rings gradually decrease from the middle to both sides. The sealing structure formed by the multiple sealing rings is a petal shape with a high middle area and a low peripheral area. The highest points of the multiple sealing rings form a peripheral sealing surface of the sealing structure, and the peripheral sealing surface cooperates with the curved area of ​​the valve body.

[0039] Furthermore, the first sealing layer, the second sealing layer and the plurality of sealing rings are completed by coating the sealing material at one time.

[0040] In addition, the sealing elements of the sealing structure can also be embedded in the grooves. The outer periphery of the valve plate body is provided with multiple grooves along the axial direction, and the sealing material is arranged on the grooves to form multiple sealing rings. The multiple sealing rings form a sealing structure. The radial height of the multiple sealing rings is higher than the height of the grooves and protrudes outward from the outer peripheral surface of the valve plate body. In the cross-section of the valve plate body along the radial direction of the valve plate body, the highest point line of the multiple sealing rings forms the outer peripheral sealing surface of the sealing structure, and the outer peripheral sealing surface cooperates with the curved surface area of ​​the valve body.

[0041] Furthermore, the first outer surface and the second outer surface on both sides of the valve plate body are respectively coated with sealing materials to form a first sealing layer and a second sealing layer, and the sealing structure is composed of the multiple sealing rings, the first sealing layer and the second sealing layer.

[0042] Furthermore, on the cross section of the valve plate, the distance between the sealing ring and the central axis of the valve plate is the height of the sealing ring. When the number of the sealing rings is an odd number, the sealing ring in the middle has the highest height. The heights of the multiple sealing rings gradually decrease from the middle to both sides, and the line connecting the highest points of the multiple sealing rings forms the peripheral sealing surface of the sealing structure. The sealing structure formed by the multiple sealing rings is an axially symmetrical structure with a high middle area and a low peripheral area.

[0043] Furthermore, on the cross section of the valve plate, the distance between the sealing ring and the central axis of the valve plate is the height of the sealing ring. When the number of the sealing rings is an even number, the two sealing rings in the middle have the highest height. The heights of the multiple sealing rings gradually decrease from the middle to both sides. The line connecting the highest points of the multiple sealing rings forms the peripheral sealing surface of the sealing structure. The sealing structure formed by the multiple sealing rings is an axially symmetrical structure with a high middle area and a low peripheral area.

[0044] Furthermore, the peripheral sealing surface of the sealing structure and the curved surface area of ​​the valve body are set to different shapes, curvatures and sizes according to the valve caliber size, fluid pressure and fluid medium type.

[0045] Furthermore, the depths of the plurality of grooves are the same, and the contour of the top connecting line of the plurality of grooves is consistent with the contour of the curved surface area of ​​the valve body.

[0046] Furthermore, the width, depth and shape of the groove are selected according to the caliber size of the valve, the fluid pressure and the type of fluid medium.

[0047] Furthermore, the groove is wide inside and narrow outside.

[0048] Furthermore, the outer contour of the valve plate body is circular and is directly formed through one-time processing.

[0049] Furthermore, the number of the sealing rings or sealing rings is adjusted according to the caliber size of the valve, the fluid pressure and the type of fluid medium.

[0050] Furthermore, the peripheral sealing surface of the sealing structure and the curved surface area of ​​the valve body are set to different shapes, curvatures and sizes according to the valve caliber size, fluid pressure and fluid medium type.

[0051] Furthermore, the surface connection between the plane area and the curved area of ​​the valve body is a cross-sectional transition, and the cross-section is processed into a chamfer, and the type and radius of the chamfer are selected according to needs.

[0052] Furthermore, the surface of the curved area of ​​the valve body is treated to change its physical and mechanical properties.

[0053] Furthermore, the surface treatment method of the curved surface area of ​​the valve body is roughening treatment.

[0054] Furthermore, a fluid passage penetrating the valve body is provided inside the valve body, and the upper side of the outer side of the valve body is provided with an upper shaft cylinder for the upper valve stem to be inserted therethrough, and the lower side is provided with a lower shaft cylinder for the lower valve stem to be inserted therethrough.

[0055] Compared with the prior art, the present invention has the following beneficial technical effects:

[0056] 1. The interior of the existing butterfly valve is a flat structure. When the valve is closed, the fluid pressure on both sides will impact the sealing structure. After long-term use, the rubber will be worn and the sealing performance will be poor. The center of the valve body of the present invention is a curved structure. A corresponding curved sealing structure is arranged on the valve plate. When the valve plate is closed, the impact force of the fluid will cause the valve plate to move to both sides. Compared with the flat structure, the curved structure is adopted to compensate for the sealing performance during the movement of the valve plate. Within a certain range, the greater the pressure, the tighter the seal, and the compensation is bidirectional.

[0057] 2. The traditional butterfly valve body is entirely covered with rubber. The present invention eliminates the traditional soft sealing valve seat structure on the inner wall of the valve body, simplifies the structure and saves costs. There is no friction between the butterfly plate and the valve seat sealing surface on the valve body during opening and closing, which reduces the wear of the sealing pair and improves the sealing performance.

[0058] 3. Existing butterfly valves all have a thicker sealing rubber ring. The present invention directly sets a sealing structure on the circumferential surface of the valve plate of the butterfly valve, and does not need to set an additional rubber sealing ring. Therefore, the use of rubber in the sealing structure of the present invention is greatly reduced compared with the prior art. Rubber is difficult to degrade in the natural environment. Reducing the use of rubber can improve the environmental performance of the valve itself and reduce the cost of raw materials.

[0059] 4. The sealing structure is equipped with multiple sealing elements to improve the sealing performance. When a sealing element is worn, other sealing elements can be replaced to improve the reliability of the seal. If one of the sealing strips is worn, it can be removed and replaced separately, avoiding the need to replace the entire large sealing ring in the prior art. The sealing materials required for maintenance can be saved during the entire life cycle, further reducing costs.

[0060] 5. The valve plate structure of the butterfly valve is optimized to reduce resistance. When the valve plate is in the open state, the thickness of the valve plate can easily affect the flow of the fluid and create resistance to the fluid. In order to reduce the impact of the valve plate on the flow of the fluid, the resistance is reduced by improving the structural characteristics of the valve plate. The sealant adopts a multi-line sealing method. Compared with the surface sealing of the entire valve plate in the prior art, the contact area becomes smaller and the friction is reduced. The driving power can be reduced during the switching process, and the torque during use is also reduced, achieving the technical effect of energy saving.

[0061] 6. For small-sized valves, a petal-shaped sealant structure is used. The petals are high in the middle and low on both sides. The outer contour of the sealing structure matches the curved surface area of ​​the valve body. The sealing layers on both sides and multiple sealing rings on the periphery are completed through one-time processing. The process is simple and convenient, and the processing cost is reduced. For large-sized valves, grooves and protrusions are processed on the valve plate, and sealants are set in the grooves. The shape of the grooves is wide inside and narrow outside to prevent the sealants from flowing out or falling off; multiple seals can buffer the impact of the fluid on the valve plate and extend the service life. Under the premise of ensuring the sealing performance, the specific shape of the groove can be adaptively set to reduce the deposition of impurities in the groove. BRIEF DESCRIPTION OF THE DRAWINGS

[0062] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings in the following description are only some embodiments of the present invention. For ordinary technicians in this field, other accompanying drawings can be obtained based on these accompanying drawings without paying creative labor.

[0063] Figure 1 It is a flow chart of the energy-saving butterfly valve structure optimization design method of the present invention;

[0064] Figure 2 It is a front view of the energy-saving butterfly valve of the present invention.

[0065] Figure 3 It is a stereoscopic diagram of the energy-saving butterfly valve of the present invention.

[0066] Figure 4 It is a cross-sectional view of the energy-saving butterfly valve of the present invention in a closed state.

[0067] Figure 5 It is a cross-sectional view of the energy-saving butterfly valve of the present invention in an open state.

[0068] Figure 6 It is a front view of the valve plate of the energy-saving butterfly valve of the present invention.

[0069] Figure 7 It is a schematic diagram of the groove structure of the valve plate of the present invention.

[0070] Figure 8 It is a cross-sectional view of the valve body groove and the embedded sealing ring structure of the present invention. DETAILED DESCRIPTION

[0071] In order to make the purpose, technical solution and advantages of the embodiments of the present application clearer, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0072] In the drawings of the specific embodiments of the present invention, in order to better and more clearly describe the working principles of the various components in the system, the connection relationship of the various parts in the device is shown, which only clearly divides the relative position relationship between the various components, and cannot constitute a limitation on the signal transmission direction, connection sequence and size, dimensions and shape of the components or structures.

[0073] like Figure 1 FIG. 1 is a flow chart of the energy-saving butterfly valve structure optimization design method of the present invention, which includes the following steps:

[0074] S1. Perform three-dimensional modeling on the energy-saving butterfly valve, create the valve body and valve plate of the energy-saving valve, and create a fluid channel that penetrates the valve body inside the valve body.

[0075] Open the 3D modeling software and set the working environment, including units, view settings, layer management, etc. Use the 3D modeling software to create the main parts of the energy-saving butterfly valve. Figure 2As shown, in the three-dimensional digital model, a valve body 1 and a valve plate 2 of an energy-saving butterfly valve are created. The valve body 1 and the valve plate 2 are used together. A fluid channel penetrating the valve body 1 is created inside the valve body 1, an upper shaft cylinder for the upper valve stem to be inserted through is created on the upper side of the outside of the valve body 1, and a lower shaft cylinder for the lower valve stem to be inserted through is created on the lower side.

[0076] like Figure 3 As shown, in the three-dimensional digital model, the internal fluid domain structure of the valve body 1 of the energy-saving butterfly valve is created, and the entire fluid domain of the valve body 1 includes two parts: a curved surface area 3 located at the center of the inner surface and a flat surface area 4 located on both sides of the center.

[0077] like Figure 4 As shown, the curved area 3 is symmetrical about the virtual center plane 5 of the valve body 1, and the thickness of the curved area 3 increases gradually and continuously from the center of the valve body to both sides; the surface connection between the plane area and the curved area is a smooth transition or a cross-sectional transition, and only the cross-sectional transition is shown in the figure. This design reduces the interference fit mode in the prior art, reduces wear, and increases the life of the valve plate.

[0078] Finally, assemble the valve plate, upper shaft cylinder, and lower shaft cylinder onto the valve body to ensure that their relative positions and dimensional relationships are correct. Set constraints in the model, such as the rotation constraints of the upper shaft cylinder and the lower shaft cylinder, and the coincidence constraints of the center axes of the valve body and the valve plate. Perform motion simulation in the model to ensure the functional correctness of the butterfly valve.

[0079] S2. Design the sealing parameters of the sealing structure around the valve plate to ensure that the actual sealing pressure of the sealing structure is within the specified range.

[0080] like Figure 5 As shown, a valve plate body 11 and a sealing structure 12 directly arranged on the valve plate body 11 are created on the valve plate. The sealing structure is radially installed on the outer periphery of the valve plate body 11 to cooperate with the inner periphery of the valve body to achieve sealing of the fluid.

[0081] like Figure 6 As shown, the sealing structure 12 has a top sealing surface 121 and a bottom sealing surface 122; the top sealing surface 121 and the bottom sealing surface 122 of the sealing structure 12 respectively cooperate with the top and the bottom of the curved area 3 of the valve body, and the middle sealing surface 120 of the sealing structure 12 also cooperates with the middle of the curved area 3 when the valve plate 2 is closed.

[0082] like Figure 8 As shown, a plurality of grooves 111 are arranged on the outer periphery of the valve plate body 11 , and the design parameters of the grooves vary according to the number of different calibers, different pressures, and different working media.

[0083] The plurality of grooves are parallel and are formed by directly machining the outer periphery of the valve plate body 11 . Sealing materials are arranged on the grooves 111 to form a plurality of sealing rings 112 . The plurality of sealing rings 112 form a sealing structure 12 .

[0084] The thickness and number of the sealing ring 112 on the outer periphery of the valve plate are designed by calculating the sealing pressure. The sealing pressure refers to the force per unit area of ​​the sealing surface on the sealing structure of the butterfly valve, and is an important indicator for judging the sealing performance. In the closed state, the sealing surface on the sealing structure will exert a certain pressure on the inner circumference of the valve body to achieve the purpose of sealing. The sealing pressure of the butterfly valve is a key factor affecting the sealing performance. When designing the sealing structure of the butterfly valve, it is necessary to ensure that the actual sealing pressure q on the sealing surface is within the range defined by the following relationship to ensure that the sealing performance of the butterfly valve meets the requirements:

[0085] q M ﹤q﹤q D ;

[0086] Among them, the minimum sealing pressure is q M The pressure acting on the butterfly valve sealing surface is not the greater the better. If it is too large and exceeds the bearing range of the valve body or the sealing ring, it will cause irreversible wear to the valve body or the sealing structure, seriously affecting the sealing performance of subsequent use. Therefore, the maximum sealing pressure q is required. D To limit the maximum pressure value on the sealing surface, the maximum pressure value can be obtained by looking up the material sealing pressure table.

[0087] The mathematical expression of the actual sealing pressure q is:

[0088] ;

[0089] Where: C and K are constants, determined based on empirical values. Preferably, they can be 2.4 and 1.2 respectively. P is the nominal pressure of the butterfly valve. b i is the thickness of the i-th sealing ring, and N is the number of sealing rings.

[0090] The nominal pressure of butterfly valves varies according to their types and working principles. When selecting and using butterfly valves, it is necessary to select the nominal pressure range according to the specific working environment and needs. For example: the working pressure of vacuum butterfly valves is lower than the standard atmospheric pressure; the nominal pressure of low-pressure butterfly valves is lower than 1.6MPa, etc.

[0091] S3. Perform fluid simulation on the three-dimensional model of the energy-saving butterfly valve to optimize the curved surface area and plane area parameters of the fluid domain.

[0092] like Figure 3As shown, the entire fluid domain of the valve body 1 includes two parts: the curved surface area 3 located at the center of the inner surface and the plane area 4 located on both sides of the center. During the fluid simulation process, the flow parameters of the curved surface area and the plane area are extracted, including: the inlet and outlet pressure and pressure difference of the plane area (the flow rate of the outlet plane area is the same as the flow rate of the inlet plane area), the average flow velocity of the fluid in the entire curved surface area, and the flow coefficient is obtained by the following calculation formula , flow resistance coefficient K.

[0093] Flow coefficient Used to evaluate the flow capacity of butterfly valves. The larger the value, the stronger the flow capacity. The calculation formula is:

[0094] ;

[0095] Where S is the surface area of ​​the plane region, Q is the volume flow rate of the plane region, ρ is the fluid density, and P 1 is the pressure before the valve, P 2 is the pressure after the valve.

[0096] The flow coefficient is limited to determine the surface area of ​​the valve body plane area.

[0097] The flow resistance coefficient K is used to indicate the resistance of the butterfly valve to the fluid. Its value depends on the curvature of the curved surface area of ​​the valve body. , the calculation formula of flow resistance coefficient K is:

[0098] ;

[0099] Where: △P is the pressure difference between the inlet and outlet of the curved area; ρ is the fluid density; v is the average velocity of the fluid.

[0100] The limitation of flow coefficient determines the curvature of the valve body surface area.

[0101] Thus, the optimized parameters of the valve body curved surface area and plane area are obtained, namely, the surface area of ​​the valve body plane area and the curvature of the curved surface area.

[0102] Example 2

[0103] like Figure 2 FIG. 1 is a schematic diagram of the structure of an energy-saving butterfly valve designed using the above structural optimization design method. The energy-saving valve of the present invention comprises a valve body 1 and a valve plate 2, and the valve body 1 and the valve plate 2 are used in combination.

[0104] The valve body is the core part of the energy-saving butterfly valve, which is used to control the flow of fluid and is arranged at the center of the flow path inside the pipeline. A fluid channel penetrating the valve body 1 is set inside the valve body 1, and an upper shaft cylinder is provided on the upper side of the outer side of the valve body 1 for the upper valve stem to be inserted through, and a lower shaft cylinder is provided on the lower side for the lower valve stem to be inserted through. The upper valve stem and the lower valve stem are rods connecting the valve drive device and the valve plate, and the upper valve stem and the lower valve stem can rotate freely to control the flow of fluid.

[0105] When the pressure of the fluid increases, it will indeed exert a greater force on the valve plate, causing the valve plate to squeeze the valve body more tightly. This squeezing effect is mainly due to the pressure of the fluid being transmitted to the valve plate, causing the valve plate to generate additional pressure in the direction of the valve body.

[0106] This phenomenon of squeezing the valve body is an important factor to be considered in valve design. In order to ensure that the energy-saving butterfly valve can still maintain a tight sealing performance under high pressure, the fit between the valve body and the valve plate usually needs to be very precise. In addition, other parts of the energy-saving butterfly valve, such as the valve stem and the drive device, also need to be able to withstand this additional load generated by the fluid pressure.

[0107] In order to ensure the stability and reliability of energy-saving butterfly valves under various pressures, detailed fluid dynamics analysis and structural analysis are also required when designing energy-saving butterfly valves. In this way, the performance of the valve under different working conditions can be predicted, so as to optimize the design and ensure the reliability and stability of the valve in actual use.

[0108] like Figure 3 As shown, the inner surface of the valve body 1 is provided with a curved surface area 3 located in the center and flat surface areas 4 located on both sides of the center;

[0109] like Figure 4 As shown, the curved area 3 is symmetrical about the virtual center plane 5 of the valve body 1, and the thickness of the curved area 3 gradually and continuously increases from the center of the valve body to both sides; the surface connection between the plane area and the curved area is a smooth transition or a cross-sectional transition, and only the cross-sectional transition is shown in the accompanying drawings; the interference mode in the prior art is reduced, the wear is reduced, and the life of the valve plate is improved.

[0110] As attached Figure 5 , 6 As shown, the valve plate 2 includes a valve plate body 11 and a sealing structure 12 directly disposed on the valve plate body 11. The top sealing surface 121 and the bottom sealing surface 122 of the sealing structure 12 respectively match the top and bottom of the curved surface area 3 of the valve body, and the middle sealing surface 120 of the sealing structure 12 also matches the middle of the curved surface area 3 when the valve plate 2 is closed, and the middle refers to the valve plate sealing structure 12 or other areas of the curved surface area 3 except the top and the bottom.

[0111] Preferably, the valve plate body 11 can be directly formed into a circular outer contour through one-time processing, and its top and bottom do not need to be processed into flat surfaces according to the prior art. Direct forming through one-time processing can reduce processing steps and reduce costs.

[0112] Example 3

[0113] The arrangement of the curved surface area, the flat surface area, etc. of the valve body of Example 3 is the same as that of Example 2, and the difference from Example 2 is the difference in the sealing structure. For a large-sized butterfly valve, if a sealing layer is directly coated on both sides of the valve plate through a one-time coating process to form two sealing layers and a sealing ring, a lot of sealing materials are used, such as a large amount of rubber materials, which is not conducive to energy conservation and emission reduction, and the low-carbon environmental protection performance is insufficient. Therefore, the sealing structure can be adjusted according to the different valve sizes.

[0114] like Figure 7 As shown, the outer periphery of the valve plate body 11 is radially provided with grooves 111 of different numbers corresponding to different calibers, different pressures, and different working media. The grooves are directly formed on the valve plate body 11, and sealing materials are arranged on the grooves 111 to form multiple sealing rings 112, and the multiple sealing rings 112 form a sealing structure 12.

[0115] The height of the sealing ring 112 in the radial direction is higher than the depth of the groove, and it protrudes outward from the outer peripheral surface of the valve body 11. The top sealing area 113 and the bottom sealing area 114 of the sealing area of ​​the valve plate are matched with the top and bottom of the curved area 3 of the valve body respectively, and the sealing materials of the two sealing areas can be arranged in a ring around the driving rod. The middle sealing surface of the sealing structure 12 also matches the middle of the curved area 3 when the valve plate 2 is closed. The middle refers to the valve plate sealing structure 12 or other areas of the curved area 3 except the top and bottom.

[0116] like Figure 8 As shown, along the radial direction of the valve plate body 11, the highest point line of the plurality of sealing rings 112 forms the peripheral sealing surface of the sealing structure, and the peripheral sealing surface matches the curved surface area 3 of the valve body. The peripheral interface of the sealing structure 12 and the curved surface area 3 of the valve body can have different shapes, curvatures, and sizes according to different calibers, different pressures, and different working media; the width and depth of the groove 111 can have different changes according to different calibers, different pressures, and different working media; the number of the sealing rings 112 can also change according to the size of the valve body with different calibers, different pressures, and different working media.

[0117] This embodiment can be used not only for large size, but also for small size. It is the same as the second embodiment. In addition to setting a sealing ring on the periphery of the valve plate body 11, the first outer surface and the second outer surface on both sides of the valve plate body 11 are also coated with sealing materials to form a first sealing layer and a second sealing layer. In this case, the sealing structure 12 is composed of a plurality of sealing rings 112 and two sealing layers. By setting the sealing layer, the corrosion of the material by the fluid can be avoided, the surface of the valve plate can be protected, and the service life of the valve plate can be increased. The sealing layer and the sealing ring can be completed together through a one-time coating process, which reduces the processing steps and reduces the production cost.

[0118] Preferably, for small sizes, the sealing structure can be set as a circumferential petal-shaped sealing ring and a surface sealing layer, the middle sealing ring of the petal-shaped sealing ring is high, and the sealing rings on both sides are low; for large sizes, grooves and raised sealing ring structures can be directly processed on the valve plate, and sealant is arranged in the groove. Multi-pass sealing can buffer the impact of the fluid on the valve plate and extend the service life. Under the premise of ensuring the sealing performance, the use of sealant can be reduced and the cost can be reduced; during the opening and closing process, there is no friction between the sealing structure on the valve plate body and the curved surface area of ​​the valve body, so that the sealing pair has little wear and tear and good sealing performance.

[0119] Preferably, the curved area is treated in different ways according to different calibers, different pressures, and different working media to change its physical and mechanical properties. For example, its surface can be roughened. The curvature of the curved area 3 can also be selected according to the specific application scenario and needs, which can avoid the valve plate of the butterfly valve being eccentric due to the water pressure for a long time, causing leakage.

[0120] Note that the above are only preferred embodiments of the present invention and the technical principles used. Those skilled in the art will understand that the present invention is not limited to the specific embodiments described herein, and that various obvious changes, readjustments and substitutions can be made by those skilled in the art without departing from the scope of protection of the present invention. Therefore, although the present invention has been described in more detail through the above embodiments, the present invention is not limited to the above embodiments, and may include more other equivalent embodiments without departing from the concept of the present invention, and the scope of the present invention is determined by the scope of the appended claims.

Claims

1. A method for optimizing the structure of an energy-saving butterfly valve, characterized in that: The steps include: S1. Perform three-dimensional modeling on the energy-saving butterfly valve, create the valve body and valve plate of the energy-saving valve, and create a fluid channel and a fluid domain that penetrates the valve body inside the valve body. The fluid domain includes a curved surface area located at the center of the inner surface and a flat surface area located on both sides of the center; S2. Design the sealing parameters of the sealing structure of the valve plate periphery to ensure that the actual sealing pressure of the sealing structure is within a limited range. A plurality of sealing rings are arranged radially on the periphery of the valve plate. The plurality of sealing rings form the sealing structure. On the cross section of the valve plate, the distance between the sealing ring and the central axis of the valve plate is the height of the sealing ring. The sealing ring height in the middle area of ​​the plurality of sealing rings is high, and the sealing ring height in the peripheral area is low, forming a petal-shaped structure. The peripheral sealing surface of the sealing structure matches the curved surface area of ​​the valve body. The peripheral sealing surface is the surface formed by the line connecting the highest points of the sealing structure. S3. Perform fluid simulation on the three-dimensional model of the energy-saving butterfly valve to optimize the curved surface area and plane area parameters of the fluid domain; The valve body fluid domain includes a curved surface area located at the center of the inner surface and a flat surface area located on both sides of the center; Calculate the flow coefficient : ； Wherein, S is the surface area flowing through the plane area, Q is the volume flow rate flowing through the plane area, is the fluid density, P1 is the pressure before the valve, and P2 is the pressure after the valve; Calculate the flow resistance coefficient K: ； in, is the pressure difference between the inlet and outlet of the curved surface area, v is the average velocity of the fluid curved surface area, is the curvature of the surface area.

2. The energy-saving butterfly valve structure optimization design method according to claim 1 is characterized in that: In step S2, the actual sealing pressure q satisfies the range defined by the following formula: q M ﹤q﹤q D ; ； Where: The minimum sealing pressure is q M , the maximum sealing pressure is q D , C and K are constants, determined based on empirical values, P is the nominal pressure of the butterfly valve, b i is the thickness of the i-th sealing ring, and N is the number of sealing rings.

3. The energy-saving butterfly valve structure optimization design method according to claim 1 is characterized in that: In step S2, multiple grooves are created on the periphery of the valve plate, and sealing rings are embedded in the grooves. The radial height of the sealing rings is higher than the depth of the grooves. The sealing rings protrude outward from the peripheral surface of the valve plate, and multiple sealing rings form a sealing structure.

4. The energy-saving butterfly valve structure optimization design method according to claim 1 is characterized in that: The curved area is symmetrical about the virtual center plane of the valve body, and the thickness of the curved area increases gradually and continuously from the center of the valve body to both sides; the surface connection between the plane area and the curved area is a smooth transition or a section transition.

5. The energy-saving butterfly valve structure optimization design method according to claim 1 is characterized in that: The sealing structure includes a top sealing surface, a middle sealing surface and a bottom sealing surface; the curved surface area of ​​the valve body includes a top, a middle and a bottom; the top sealing surface, the middle sealing surface and the bottom sealing surface respectively cooperate with the top, the middle and the bottom of the curved surface area of ​​the valve body; the top sealing surface and the bottom sealing surface refer to areas that are respectively sealed and cooperated with the top and the bottom of the curved surface area of ​​the valve body when the valve plate is open or closed, and the middle sealing surface refers to an area that is sealed and cooperated with the middle of the curved surface area when the valve plate is closed.

Images