Carbon fiber composite material valve and design method thereof

Abstract

The invention discloses a carbon fiber composite material valve and a design method thereof, and belongs to the field of valve design, an actual valve body adopts a metal material as an inner container, the outer layer is coated with a CFRP material, and the two materials are glued into a whole through epoxy resin. The thickness of the CFRP material coated at different positions of the valve body is different, the thicker positions of the CFRP layer are the inner sides of the flanges at the two ends, the outer wall of the position connected with the large bolt and the annular outer wall in the flow direction of the valve body, and the other areas are only coated with the thinner CFRP layer as the appearance, so that the complete valve body of the carbon fiber composite material valve is formed. Meanwhile, the invention further discloses a design method of the carbon fiber composite material valve. The valve body of the valve is made of the CFRP instead of part of metal materials, weight reduction and noise reduction of the carbon fiber composite valve can be achieved by means of the advantages of low density and high vibration resistance of the CFRP, and the disadvantages of large weight and large noise of a traditional metal valve are overcome. The forming process of the CFRP material is facilitated.

Description

Technical Field

[0001] The invention belongs to the field of valve design and relates to a carbon fiber composite material valve and a design method thereof. The valve body of the valve is a structure with a metal material as an inner shell and an outer layer covered with a CFRP material. Background Art

[0002] At present, the metal valves of traditional ships are heavy, and the weight of large-diameter valves can reach more than one ton. There are usually many valves on ships, and the pipelines are long and complicated, resulting in the valve system occupying a large weight ratio. In terms of transportation, the heavy valve system will affect the overall cargo capacity, passenger capacity and fuel efficiency of the ship, and affect the transportation cost. In terms of installation and maintenance, overweight valves increase the difficulty of installation and maintenance, and waste manpower and material resources. At the same time, overweight valves themselves also have greater safety hazards. Therefore, the lightweight design of valves can improve the safety factor of the entire ship, reduce transportation costs, and improve overall performance.

[0003] Since the valve and pipeline system of a ship has a wide coverage and complex structure, it generates a lot of noise. Excessive noise not only affects the hearing health of operators, but also affects the stealth capability of the entire ship. At the same time, the excessive amplitude of traditional metal valves will also affect their service life. At present, most methods of adding silencers or outsourcing damping materials are used to reduce valve noise, but these methods will further increase the weight of the valve system. Therefore, improvements in the structure or materials of the valve itself can reduce valve noise without increasing the weight of the valve.

[0004] Carbon fiber reinforced plastic (CFRP) is a damping material with the advantages of light weight, high specific strength, good specific stiffness, strong designability, and excellent vibration reduction performance, which is beneficial to reducing the vibration of the structure. At present, CFRP is widely used in the automotive and aerospace fields. Compared with traditional metal materials, CFRP can not only significantly reduce the weight of the structure, but also improve the strength of the structure to a certain extent. At the same time, due to its vibration reduction performance, it can further improve the safety and stability of the structure. Therefore, applying CFRP to the valve structure and replacing part of the metal on the outside of the valve body with CFRP material can not only achieve the lightweight of the valve system, but also reduce the vibration of the valve and achieve the purpose of noise reduction. Summary of the invention

[0005] In order to solve the shortcomings of traditional metal valves, such as heavy weight and high noise, the present invention uses CFRP material to replace part of the outer wall material of the original metal regulating valve body, and uses epoxy resin to glue the CFRP and the metal valve body inner liner to form a complete valve body structure, which can reduce the weight of the valve and use the vibration-damping property of CFRP to reduce the noise generated when the valve is working.

[0006] In order to achieve the above object, the technical solution adopted by the present invention is:

[0007] A carbon fiber composite material valve, the carbon fiber composite material valve includes a valve body 2, a spring pressure cover 3, a valve seat 4, a ball 5, a spring 6, a diffuser 7, an orifice plate 8, a guide sleeve 9, a large bolt 10, a guide sleeve 11, a valve stem 12, an upper cover 13 and a seal. Compared with traditional metal valves, the design improvements of the present invention (improvements on the original metal valve body) are as follows: the valve body 2 is a valve body structure composed of two basic materials, a metal material and a CFRP material, which is bonded together. The metal material is used as the inner liner 201, and the outer layer 202 is coated with CFRP material to form a CFRP layer. The two materials are bonded together by epoxy resin to form a whole, wherein the thickness of the CFRP material coated at different positions of the valve body 2 is different. Specifically:

[0008] Furthermore, the locations where the CFRP layer is thicker are the inner sides of the flanges 205 at both ends, the outer wall of the large bolt position 206, and the annular outer wall 203 along the flow direction of the valve body 2, and the remaining outer surface areas are only covered with a thinner CFRP layer as an appearance, forming a complete carbon fiber composite valve body.

[0009] Furthermore, the carbon fiber composite material valve structure is specifically:

[0010] The valve body 2 has a thread 207 at the inlet thereof for connecting the spring pressure cover 3. The spring pressure cover 3 and the outer wall of the valve seat 4 are fitted with a clearance, and the valve seat 4 and the ball 5 are in contact with each other through a dynamic sealing ring. At the same time, the valve seat 4 is fixedly constrained by the clamping force generated by the spring 6 between the spring pressure cover 3 and the valve seat 4 and the contact with the ball 5.

[0011] The valve body 2 has a thread 208 at its outlet for connecting the diffuser 7. The diffuser 7 is in contact with the orifice plate 8, and the orifice plate 8 is in contact with the guide sleeve 9. The orifice plate 8 and the guide sleeve 9 are fixedly restrained by the inner wall structure of the valve body 2 and the diffuser 7.

[0012] The flange 204 at the upper end of the valve body 2 is processed with a through hole 209 for receiving the valve stem 12 and the upper cover 13. The end of the valve stem 12 is embedded in the ball 5 to control the rotation of the ball 5 and limit the degree of freedom.

[0013] The valve body 2 has a thread 211 at the lower end thereof for connecting with a large bolt 10 . The end of the large bolt 10 is connected with the ball 5 through a guide sleeve 11 to limit the freedom of the ball 5 .

[0014] The flanges 205 on both sides of the valve body 2 are processed with a plurality of through holes 212 for bolt connection between the valve body 2 and pipeline accessories.

[0015] A method for designing a carbon fiber composite material valve comprises the following steps:

[0016] The first step is to improve the structure of the original metal valve body 1. Figure 1 and 2 As shown, the oblique curved annular outer wall 101 of the original metal valve body 1 is changed to the equal-diameter curved outer wall 203 of the valve body 2; the flange of the middle flange 102 of the original titanium alloy valve body 1 is removed and replaced with the middle flange 204 structure of the valve body 2 for winding molding of CFRP prepreg.

[0017] The second step is to select the main force-bearing position of the valve body 2, that is, the annular outer wall 203 along the flow direction of the valve body 2, and use CFRP material to replace part of the metal material of the outer wall at this position, and use the equal stiffness replacement formula to determine the thickness range of the replaced CFRP material. The formula is:

[0018]

[0019] Where: t M ,t C are the thickness of the metal material before replacement and the thickness of the CFRP material after replacement; E M 、E C are the metal stiffness and the CFRP hoop stiffness of the valve body respectively; α is the thickness index coefficient, which is usually 1 to 3.

[0020] According to the value range of α, determine t T The value range of [t a ,t b ].

[0021] According to t T The value range of [t a ,t b ], the valve bodies with different thicknesses of CFRP are selected for static simulation. The single-layer thickness t0 of CFRP prepreg is a fixed value, so t T In [t a ,t b ] is a discrete value, and a thickness value t is selected for each additional n layers of CFRP material. i (i=1,2,3,…,m), and satisfies t i+1 =t i +nt0. That is, in [t a ,t b ] range, select t1, t2, t3…t m Static simulation of the CFRP valve body with different thickness.

[0022] The third step is to compare the maximum stress σ of the valve body with different thicknesses of CFRP layers based on the static simulation results of the second step. i(i=1,2,3,…,m) and the maximum stress σ of the original metal valve body T . Select the thickness value t that is closest to the result i (i=1,2,3,…,m) as the final thickness t of the CFRP layer F That is, the final CFRP thickness should satisfy the following relationship:

[0023]

[0024] In the fourth step, the inner side of the flange 103 on both sides of the valve body 1 and the outer wall of the large bolt position 104 are replaced with equal thickness, that is, the original part of the metal material is removed, and the thickness is t Mf and t Mb , replaced by a CFRP material of equal thickness covering the surface, with a thickness of t Cf and t Cb , where t Mf =t Cf , t Mb =t Cb The remaining outer surface areas, namely the edge and outer side of the end flange, the surface of the middle flange and the lower edge of the large bolt position are only covered with 1 to 2 layers of CFRP as the appearance, thus forming a complete carbon fiber composite valve body.

[0025] In the fifth step, all contact surfaces between the CFRP material and the metal material are bonded by epoxy resin glue to form the CFRP valve body.

[0026] The beneficial effects of the present invention are:

[0027] (1) The valve body of the valve designed by the present invention adopts CFRP material to replace part of the metal material, and the advantages of CFRP's low density and strong vibration resistance can be used to achieve weight reduction and noise reduction of the carbon fiber composite material valve, thereby improving the disadvantages of traditional metal valves with heavy weight and high noise.

[0028] (2) The valve body of the present invention adopts a metal valve body with an improved shape as the inner shell, and is coated with CFRP material on the outside. Other parts are still made of metal materials, which is not only conducive to the molding process of CFRP materials, but also avoids the hygrothermal aging caused by direct contact between CFRP materials and media such as water or seawater.

[0029] (3) The metal outer surface of the present invention is fully covered with CFRP material, which not only avoids debonding at the edge where CFRP and metal are bonded, but also makes the shape more beautiful.

[0030] (4) The design of the present invention adopts an equal stiffness replacement method for the main stress-bearing position of the valve body of the valve, replacing part of the metal material with CFRP material, which can reduce the weight of the valve body and ensure the mechanical properties of the valve body to a certain extent. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 It is a schematic diagram of the original metal valve body structure.

[0032] Figure 2 It is a schematic diagram of the structure of the carbon fiber composite material valve body of the present invention.

[0033] Figure 3 yes Figure 1 Half-section view of the schematic diagram of the carbon fiber composite valve body structure.

[0034] Figure 4 It is a half-section view of the carbon fiber composite material valve assembly drawing.

[0035] Figure 5 It is a flow chart of the design method of carbon fiber composite valves.

[0036] In the figure: 1 original titanium alloy valve body; 2 valve body; 3 spring gland; 4 valve seat; 5 ball; 6 spring; 7 diffuser; 8 orifice plate; 9 guide sleeve; 10 large bolt; 11 guide sleeve; 12 valve stem; 13 upper cover; 14 bolt;

[0037] 101 circumferential outer wall; 102 middle flange; 103 end flange; 104 large bolt position; 201 inner liner; 202 outer layer; 203 circumferential outer wall; 204 middle flange; 205 end flange; 206 large bolt position; 207 thread; 208 thread; 209 through hole; 210 threaded hole; 211 thread; 212 through hole. DETAILED DESCRIPTION

[0038] The present invention will be described in detail below with reference to the accompanying drawings and in conjunction with embodiments.

[0039] like Figure 2 and Figure 3 As shown. A valve body of a carbon fiber composite valve. The valve body 2 is a valve body composed of two basic materials, metal and CFRP. The valve body is made of a metal material 201 as an inner shell and a CFRP material 202 as an outer layer, and the two materials are bonded together by epoxy resin to form a whole.

[0040] like Figure 3 In this embodiment, the thickness of the CFRP material coated at different positions of the valve body 2 is different, wherein the positions with thicker CFRP layers are the inner sides of the end flanges 205 on both sides, the outer wall of the connecting large bolt position 206, and the annular outer wall 203 along the flow direction of the valve body, and the remaining areas are only coated with a thinner CFRP layer as the appearance, thereby forming a complete carbon fiber composite valve body.

[0041] like Figure 3 and Figure 4In this embodiment, a thread 207 is processed at the inlet of the valve body 2 for connecting the spring pressure cover 3, the spring pressure cover 3 and the outer wall of the valve seat 4 are in clearance, the valve seat 4 and the ball 5 are in contact through the dynamic sealing ring, and the valve seat 4 is fixedly constrained by the compression force generated by the spring 6 between the spring pressure cover 3 and the valve seat 4 and the contact with the ball 5.

[0042] like Figure 3 and Figure 4 In this embodiment, a thread 208 is processed at the outlet of the valve body 2 for connecting the diffuser 7, the diffuser 7 is in contact with the orifice plate 8, the orifice plate 8 is in contact with the guide sleeve 9, and the orifice plate 8 and the guide sleeve 9 are fixedly constrained through the inner wall structure of the valve body 2 and the contact of the diffuser 7.

[0043] like Figure 3 and Figure 4 In this embodiment, the middle flange 204 of the valve body 2 is processed with a through hole 209 for receiving the valve stem 12 and the upper cover 13, and the end of the valve stem 12 is embedded in the ball 5 to control the rotation of the ball 5 and limit the degree of freedom.

[0044] like Figure 3 Shown and Figure 4 In this embodiment, six threaded holes 210 are processed around the through hole 209 of the valve body 2 for connecting the valve body 2 with the bolts 14 of the upper cover 13, and the upper cover is used to connect the valve actuator structure.

[0045] like Figure 3 and Figure 4 In this embodiment, a thread 211 is processed on the lower end of the valve body 2 for connecting a large bolt 10, and the end of the large bolt 10 is connected to the ball 5 through a guide sleeve 11 to limit the freedom of the ball.

[0046] like Figure 3 and Figure 4 In this embodiment, six through holes 212 are processed on the flanges 205 on both sides of the valve body 2 for bolt connection between the valve body 2 and pipeline accessories.

[0047] like Figure 5 As shown. The design method of carbon fiber composite valve is:

[0048] The first step is to improve the structure of the original metal valve body 1. Figure 1 and 2 As shown, the oblique curved annular outer wall 101 of the original metal valve body 1 is changed to the equal-diameter curved outer wall 203 of the valve body 2; the flange of the middle flange 102 of the original titanium alloy valve body 1 is removed and replaced with the middle flange 204 structure of the valve body 2 for winding molding of CFRP prepreg.

[0049] The second step is to select the main force-bearing position of the valve body 2, that is, the annular outer wall 203 along the flow direction of the valve body 2, and use CFRP material to replace part of the metal material of the outer wall at this position, and use the equal stiffness replacement formula to determine the thickness range of the replaced CFRP material. The formula is:

[0050]

[0051] Where: t M ,t C are the thickness of the metal material before replacement and the thickness of the CFRP material after replacement; E M 、E C are the metal stiffness and the CFRP hoop stiffness of the valve body, respectively. M =110MPa, E C =66MPa; α is the thickness index coefficient, usually ranging from 1 to 3.

[0052] According to the value range of α, and take t M =3mm, determine t T The value range is [3.6mm,5.0mm].

[0053] According to t T The value range is [3.6mm, 5.0mm]. The valve bodies with different thicknesses of CFRP within the range are selected for static simulation. The single layer thickness of CFRP prepreg is 0.2mm, so t T The value is a discrete value, and a thickness value is selected for every 3 layers of CFRP material added And satisfy t i+1 =t i +0.6mm. That is, at [t a ,t b ], the CFRP valve body with thickness of t1=3.6mm, t2=4.2mm, t3=4.8mm was taken for static simulation. The simulation results are shown in Table 1:

[0054] Table 1 Valve simulation results

[0055]

[0056] The third step is to compare the maximum stress σ of the valve body with different thicknesses of CFRP layers based on the static simulation results of the second step. i (i=1,2,3) and the maximum stress σ of the original metal valve body T . Select the thickness value t that is closest to the result i (i=1,2,3) as the final thickness t of the CFRP layer F That is, the final CFRP thickness should satisfy the following relationship:

[0057]

[0058] According to the simulation results in Table 1 and formula (2), the final CFRP thickness can be determined as t3 = 4.8 mm.

[0059] In the fourth step, the inner side of the flange 103 on both sides of the valve body 1 and the outer wall of the connecting large bolt position 104 are replaced with equal thickness, that is, the original part of the metal material is removed, and the thickness is t Mf =5mm and t Mb =3mm, replaced by a CFRP material of equal thickness covering the surface, with a thickness of t Cf =5mm and t Cb =3mm. The remaining outer surface areas, i.e. the edge and outer side of the end flange, the surface of the middle flange and the lower edge of the large bolt position are only covered with 2 layers of CFRP as the appearance, thus forming a complete carbon fiber composite valve body. All contact surfaces between CFRP material and metal material are bonded by epoxy resin glue to form the CFRP valve body.

[0060] The above-described embodiments merely express the implementation methods of the present invention, but they cannot be understood as limiting the scope of the patent of the present invention. It should be pointed out that for those skilled in the art, several modifications and improvements can be made without departing from the concept of the present invention, which all belong to the protection scope of the present invention.

Claims

1. A carbon fiber composite material valve, characterized in that: The carbon fiber composite material valve comprises a valve body (2), a spring pressure cover (3), a valve seat (4), a ball (5), a spring (6), a diffuser (7), an orifice plate (8), a guide sleeve (9), a large bolt (10), a guide sleeve (11), a valve stem (12), an upper cover (13) and a sealing member; the valve body (2) is a composite valve body structure composed of two materials, a metal material and a CFRP material, wherein the metal material is used as an inner shell (201), and the outer layer (202) is coated with CFRP material to form a CFRP layer, and the two materials are bonded together by epoxy resin to form a whole, wherein the thickness of the CFRP material coated at different positions of the valve body (2) is different.

2. A carbon fiber composite material valve according to claim 1, characterized in that: The locations where the CFRP layer is relatively thick are the inner sides of the flanges (205) at both ends, the outer wall of the connecting large bolt location (206), and the annular outer wall (203) along the flow direction of the valve body (2), and the remaining outer surface areas are only covered with a relatively thin CFRP layer as an appearance, forming a complete carbon fiber composite material valve body.

3. The carbon fiber composite material valve according to claim 1, characterized in that: The carbon fiber composite material valve structure is specifically as follows: The inlet of the valve body (2) is processed with a thread (207) for connecting the spring pressure cover (3). The spring pressure cover (3) and the outer wall surface of the valve seat (4) are matched through a clearance, and the valve seat (4) and the ball (5) are in contact through a dynamic sealing ring. At the same time, the valve seat (4) is in contact with the ball (5) through the compression force generated by the spring (6) between the spring pressure cover (3) and the valve seat (4), thereby achieving fixed constraint; The valve body (2) is processed with a thread (208) at the outlet thereof for connecting with a diffuser (7); the diffuser (7) is in contact with an orifice plate (8); the orifice plate (8) is in contact with a guide sleeve (9); the orifice plate (8) and the guide sleeve (9) are fixedly restrained by contacting with the inner wall structure of the valve body (2) and the diffuser (7); The flange (204) at the upper end of the valve body (2) is processed with a through hole (209) for receiving the valve stem (12) and the upper cover (13); the end of the valve stem (12) is embedded in the ball (5) to control the rotation of the ball (5) and limit the degree of freedom; The lower end of the valve body (2) is processed with a thread (211) for connecting a large bolt (10); the end of the large bolt (10) is connected to the ball (5) through a guide sleeve (11) to limit the freedom of the ball (5); The flanges (205) on both sides of the valve body (2) are processed with a plurality of through holes (212) for connecting the valve body (2) with pipelines.

4. A method for designing a carbon fiber composite material valve according to any one of claims 1 to 3, characterized in that: The following steps are involved: The first step is to change the oblique curved annular outer wall (101) of the original metal valve body (1) into the equal-diameter curved outer wall (203) of the valve body (2); remove the middle flange (102) of the original titanium alloy valve body (1) and replace it with the middle flange (204) structure of the valve body (2) for winding molding of CFRP prepreg; In the second step, the main force-bearing position of the valve body (2) is selected, the annular outer wall (203) along the flow direction of the valve body (2) is made of CFRP material, and the thickness range of the CFRP material is determined by using an equal stiffness replacement formula; the formula is: Where: t M ,t C are the thickness of the metal material before replacement and the thickness of the CFRP material after replacement; E M 、E C are the metal stiffness and the CFRP hoop stiffness of the valve body respectively; α is the thickness index coefficient; According to the value range of α, determine t T The value range of [t a ,t b ]; According to t T The value range of [t a ,t b ], the valve bodies with different thicknesses of CFRP are selected for static simulation. The single-layer thickness t0 of CFRP prepreg is a fixed value, t T In [t a ,t b ] is a discrete value, and a thickness value t is selected for each additional n layers of CFRP material. i , where i = 1, 2, 3, ..., m, and satisfies t i+1 =t i +nt0; that is, in [t a ,t b ] range, select t1, t2, t3…t m Static simulation of the valve body of CFRP with thickness; The third step is to compare the maximum stress σ of the valve body with different thicknesses of CFRP layers based on the static simulation results of the second step. i (i=1,2,3,…,m) and the maximum stress σ of the original metal valve body T ; Select the thickness value t that is closest to the result i As the final thickness of the CFRP layer t F ; The CFRP thickness determined should satisfy the following relationship: In the fourth step, the inner side of the flanges (103) on both sides of the valve body (1) and the outer wall of the connecting large bolt position (104) are designed with equal thickness, and the thickness of the CFRP layer is t Cf and t Cb The remaining outer surface areas, i.e. the edge and outer side of the end flange, the surface of the middle flange and the lower edge of the large bolt position are only covered with 1 to 2 layers of CFRP as the appearance to form a complete carbon fiber composite valve body; In the fifth step, all contact surfaces between the CFRP material and the metal material are bonded by epoxy resin glue to form the CFRP valve body.

5. The method for designing a carbon fiber composite material valve according to claim 4, characterized in that: The value of α in the second step is 1-3.

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