A sealing ball valve for liquid carbon dioxide delivery pipelines

Abstract

This invention relates to a sealing ball valve for a liquid carbon dioxide conveying pipeline, comprising a valve body assembly including a valve seat, a valve core, and a valve stem. The valve core is rotatably disposed inside the valve seat, and one end of the valve core is fixed to the valve stem. The other end of the valve stem passes through the valve seat and is rotatably connected to the valve seat. The valve seat includes an upstream pipeline and a downstream pipeline. The valve core includes an integrally formed inlet portion, a channel portion, and an outlet portion. The inlet portion is located upstream of the channel portion, and the outlet portion is located downstream of the channel portion. The diameter of the outlet portion is larger than the diameter of the channel portion, and the diameter of the channel portion is the same as the diameter of the upstream pipeline. The de-icing assembly includes a shell, a heat-conducting membrane, and a phase change energy storage fluid. The shell is circumferentially embedded in the side surface of the channel portion and the inner wall surface of the outlet portion. The phase change energy storage fluid is disposed inside the shell, and the heat-conducting membrane seals and covers the opening of the shell. Through the cooperation of the valve body assembly and the de-icing assembly, the technical problem of valve jamming caused by the flash evaporation of liquid carbon dioxide to generate dry ice can be solved.

Description

Technical Field

[0001] This invention belongs to the field of ball valve technology, and specifically relates to a sealing ball valve for liquid carbon dioxide conveying pipelines. Background Technology

[0002] Liquid carbon dioxide, due to its high density and ease of storage and transportation, is widely used in petrochemical, supercritical extraction, and geological storage applications. In liquid carbon dioxide transportation pipelines, the sealing ball valve, as the core component controlling the flow of the medium, directly affects the safe and stable operation of the entire transportation system through its sealing and opening / closing reliability.

[0003] However, existing ball valves typically employ conventional resilient seats or metal hard seals. Liquid carbon dioxide is extremely sensitive to changes in temperature and pressure. During valve opening, closing, or throttling, the local pressure in the valve cavity drops sharply, easily causing the liquid carbon dioxide to flash. This instantaneous vaporization absorbs heat, causing a rapid temperature drop and forming solid dry ice. Existing ball valves have a pre-existing sealing gap and spring compensation chamber between the valve seat and the ball. The dry ice generated by flashing is easily squeezed and accumulates in this gap. The high hardness of dry ice and its inability to flow back leads to a sharp increase in friction between the ball and the valve seat, resulting in valve jamming and inability to open and close normally.

[0004] If a ball valve fails due to dry ice blockage, it can not only cause transmission interruption and media leakage, but also easily lead to serious safety accidents such as pipeline overpressure. Therefore, there is an urgent need to develop a new type of sealing ball valve that can effectively prevent flash evaporation and dry ice formation, and prevent dry ice accumulation that can cause valve blockage. This is of paramount importance and urgency in ensuring the inherent safety of pipelines. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to overcome the defect of valve jamming caused by the flash evaporation of liquid carbon dioxide to generate dry ice in the prior art, thereby providing a sealing ball valve for liquid carbon dioxide conveying pipelines.

[0006] To achieve the above objectives, the present invention adopts the following technical solution: A sealing ball valve for a liquid carbon dioxide delivery pipeline, comprising: A valve body assembly includes a valve seat, a valve core, and a valve stem. The valve core is rotatably disposed inside the valve seat. One end of the valve core is fixed to the valve stem, and the other end of the valve stem passes through the valve seat and is rotatably connected to the valve seat. The valve seat includes an upstream pipe and a downstream pipe. The valve core includes an integrally formed inlet, a channel, and an outlet. The inlet is located upstream of the channel, and the outlet is located downstream of the channel. The diameter of the outlet is larger than the diameter of the channel, and the diameter of the channel is the same as the diameter of the upstream pipe. A de-icing assembly is disposed on the inner wall surface of the channel portion and the outlet portion. The de-icing assembly includes a housing, a thermally conductive film, and a phase change energy storage fluid. The housing is circumferentially embedded in the side surface of the channel portion and the inner wall surface of the outlet portion. The phase change energy storage fluid is disposed inside the housing. The thermally conductive film seals and covers the opening of the housing.

[0007] Preferably, the diameter of the upstream pipe is equal to the diameter of the inlet and the diameter of the channel, the diameter of the outlet gradually increases along the flow direction of liquid carbon dioxide, and the diameter of the downstream pipe is greater than the maximum diameter of the outlet.

[0008] Preferably, the valve seat includes an upstream valve seat and a downstream valve seat, which are integrally formed; The upstream valve seat includes a main body and a docking part. The docking part is integrally formed on one end of the main body along the axial direction close to the valve core. The docking part connects the upstream pipeline with the inlet, thereby stabilizing the fluid pressure inside the pipe.

[0009] Preferably, the valve seat includes a mounting cavity, the mounting cavity is provided between the upstream valve seat and the downstream valve seat, the valve core and the docking part are both disposed in the mounting cavity, and the upstream pipeline and the downstream pipeline are connected through the mounting cavity.

[0010] Preferably, the valve body assembly further includes a plurality of seals, one end of which is fixedly disposed with the inner wall surface of the mounting cavity, and the other end of which abuts against the outer surface of the valve core.

[0011] Preferably, the valve core is provided with multiple layers of the de-icing assembly along the circumferential channel on the side facing the downstream pipe, and each layer of the de-icing assembly is provided with multiple components, and the depth of the housing gradually decreases in the direction away from the axis. The distance from the seal to the axis is greater than the distance from the de-icing assembly to the axis.

[0012] Preferably, the diameter of the shell gradually decreases along the direction of liquid carbon dioxide flow, and the shell has rounded corners around its perimeter, so that when the de-icing component deforms to break the ice, the curvature of the heat-conducting film is greater to achieve a better de-icing effect.

[0013] Preferably, the downstream valve seat has an arc-shaped pressure-guiding surface, and the diameter of the pressure-guiding surface first increases and then decreases along the flow direction of liquid carbon dioxide.

[0014] Compared with the prior art, the beneficial effects of the present invention are as follows: The sealing ball valve for liquid carbon dioxide delivery pipelines provided in the above technical solution effectively solves the problem of valve jamming caused by dry ice formation from the flash evaporation of liquid carbon dioxide through the coordinated operation of the valve body assembly and the de-icing assembly. In the valve body assembly, the valve stem and valve core are fixed and rotatably connected to the valve seat, driving the valve core to rotate within the valve seat, thereby controlling the opening and closing of the upstream and downstream pipelines. The valve core's integrally formed inlet, channel, and outlet sections cooperate with each other. The diameter of the channel section is the same as that of the upstream pipeline to ensure a stable flow field, while the diameter of the outlet section is larger than that of the channel section, forming a gradually expanding flow channel, effectively reducing flow velocity and local pressure drop, and structurally suppressing flash evaporation. The de-icing assembly is located on the inner wall of the channel and outlet sections, with the shell embedded circumferentially on the side. It is filled with a phase change energy storage liquid, and a thermally conductive film seals the shell opening. When flash evaporation occurs, the phase change energy storage liquid undergoes a phase change upon cooling and releases latent heat through the thermally conductive film, preventing dry ice from freezing; furthermore, the volume change caused by the phase change causes the thermally conductive film to bulge and deform, mechanically peeling off the dry ice. The anti-flash evaporation structure of the valve body assembly works in conjunction with the thermal and mechanical ice-breaking mechanism of the de-icing assembly to eliminate the risk of jamming. Attached Figure Description

[0015] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort. Figure 1 A sectional view of the overall assembly of the sealing ball valve for liquid carbon dioxide conveying pipeline provided by the present invention; Figure 2 A cross-sectional view of the ball valve provided by the present invention; Figure 3 This is a schematic diagram of the structure of the de-icing assembly provided by the present invention; Figure 4 This is a schematic diagram illustrating the de-icing principle of the de-icing assembly provided by the present invention.

[0016] Explanation of reference numerals in the attached figures: 1. Valve body assembly; 11. Valve seat; 111. Upstream valve seat; 1111. Main body; 1112. Connecting part; 1113. Upstream pipe; 112. Downstream valve seat; 1121. Pressure guiding surface; 1122. Downstream pipe; 113. Housing cavity; 12. Valve core; 121. Inlet part; 122. Channel part; 123. Outlet part; 13. Valve stem; 14. Seal; 2. De-icing assembly; 21. Housing; 22. Thermal conductive film; 23. Phase change energy storage fluid; 3. Dry ice. Detailed Implementation

[0017] The technical solution of the present invention will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0018] In the description of this invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0019] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0020] Please see Figure 1 and Figure 2 The present invention provides a sealing ball valve for a liquid carbon dioxide delivery pipeline. The ball valve includes a valve body assembly 1 and a de-icing assembly 2.

[0021] Valve body assembly 1 includes a valve seat 11, a valve core 12, and a valve stem 13. The valve seat 11 serves as the support and housing for the entire ball valve. The valve core 12 is the key moving component controlling the flow of fluid, and its overall shape is a spherical or near-spherical structure with specific internal flow channels. The valve core 12 is rotatably disposed inside the valve seat 11. Specifically, the upper and lower ends of the valve core 12 are usually provided with pivots or structures connected to the valve stem 13, allowing the valve core 12 to rotate about an axis perpendicular to the direction of fluid flow. One end of the valve stem 13 is fixedly connected to the valve core 12. This fixed connection can be a key connection, a pin connection, or integral molding, to ensure that the valve stem 13 can accurately transmit external drive to the valve core 12. The other end of the valve stem 13 passes through the valve seat 11 and extends to the outside of the valve body. The valve stem 13 and the valve seat 11 are rotatably and sealingly connected by bearings or sealing packing, thereby achieving rotational drive while preventing media leakage.

[0022] The valve seat 11 is divided into an upstream pipe 1113 and a downstream pipe 1122 in the fluid flow path. The upstream pipe 1113 connects to the incoming flow direction of liquid carbon dioxide, while the downstream pipe 1122 leads to the downstream of the delivery pipe. The internal flow channels of the valve core 12 are not simple straight holes of equal diameter, but adopt a design with specific functional partitions. Specifically, the valve core 12 includes an integrally formed inlet portion 121, a channel portion 122, and an outlet portion 123. Here, "integral forming" means that these three parts are directly formed on the same valve core 12 blank by means of casting, machining, etc., without seams or assembly gaps. This helps to reduce flow resistance and avoid the accumulation of medium in gaps or uncontrollable phase changes.

[0023] From the perspective of fluid flow direction, inlet 121 is located upstream of channel 122, and its function is to receive liquid carbon dioxide from upstream pipe 1113 with minimal flow resistance. Channel 122 is a straight tubular flow channel, and its diameter is precisely designed to be exactly the same as that of upstream pipe 1113. This equal-diameter design is crucial, as it ensures that the cross-sectional area of ​​the flow channel does not change abruptly when liquid carbon dioxide flows from upstream pipe 1113 through inlet 121 and into channel 122. According to the fluid continuity equation, under constant flow rate, a constant cross-sectional area means a constant flow velocity; combined with Bernoulli's principle, a constant flow velocity means that the static pressure will not fluctuate drastically due to changes in cross-sectional area. This eliminates the possibility of a sudden pressure drop induced by a sudden expansion or contraction of the flow channel, thereby suppressing the possibility of flash evaporation. Outlet 123 is located downstream of channel 122, and its diameter is designed to be larger than that of channel 122. This structure allows the flow channel to gradually expand as liquid carbon dioxide flows through the outlet 123, resulting in a corresponding decrease in flow velocity and a certain degree of pressure recovery, further consolidating the effect of suppressing flash evaporation.

[0024] To address the issue of localized flash evaporation and dry ice formation 3 that may still occur under extreme operating conditions even after flow channel optimization, this invention specifically includes a de-icing assembly 2. The de-icing assembly 2 is not an additional part independent of the valve core 12, but rather embedded and integrated into the internal wall surface of the valve core 12. Specifically, the de-icing assembly 2 is located on the inner wall surfaces of the channel portion 122 and the outlet portion 123, because these areas are where the temperature drop is greatest and where dry ice 3 is most likely to form and accumulate. Figure 2 and Figure 3As shown, the de-icing assembly 2 includes a housing 21, a thermally conductive film 22, and a phase change energy storage fluid 23. The housing 21 is a recessed or grooved structure with an opening, circumferentially embedded in the side of the channel portion 122 and the side of the outlet portion 123. "Circumferentially embedded" means that multiple housings 21 are evenly distributed along the circumference of the inner wall of the valve core 12, forming one or more rings to ensure comprehensive thermal management and mechanical de-icing coverage of the inner wall surface. The phase change energy storage fluid 23 fills and seals the interior of the housing 21, occupying 70% to 95% of the internal volume of the housing 21, with some expansion space reserved. The thermally conductive film 22 completely covers and seals the opening of the housing 21 by welding, bonding, or mechanical compression. The outer surface of the thermally conductive film 22 is basically flush with or slightly lower than the inner wall surface of the valve core 12 to avoid unnecessary disturbance to the main fluid.

[0025] Phase change fluid 23 is a medium with a phase change temperature between -60℃ and -90℃, slightly higher than the freezing point of dry ice 3 at -78.5℃. Under normal operating temperature, phase change fluid 23 is liquid. When the temperature of the inner wall of valve core 12 drops sharply below its phase change point due to flash evaporation, phase change fluid 23 undergoes a liquid-solid phase change, releasing a large amount of latent heat of phase change in the process. This heat is rapidly transferred to the dry ice 3 on the wall surface through a highly thermally conductive film 22 (which can be made of thermally conductive silicone, graphene film, or thin metal sheet), raising its temperature or slowing its further solidification rate; this is the thermal de-icing mechanism. Even more ingeniously, many substances expand in volume upon solidification. By rationally selecting the composition of the phase change energy storage fluid 23 (such as an aqueous solution or saline hydrate), and utilizing its solidification expansion characteristics, when the phase change energy storage fluid 23 inside the shell 21 solidifies, its volume increases, causing inward-outward compression of the shell 21's wall and the heat-conducting film 22. Since the bottom and sidewalls of the shell 21 are embedded in the robust valve core 12 matrix, their deformation capacity is limited. However, the heat-conducting film 22, acting as a sealing layer, possesses a certain degree of elasticity or flexibility. Therefore, the heat-conducting film 22 will undergo controllable bulging deformation towards the internal flow channel of the valve core 12. This sudden, minute bulging action directly impacts, tears, or peels off the dry ice 3 adhering to its surface, causing it to detach from the wall and be washed away by the fluid; this is the mechanical de-icing mechanism. Figure 4 As shown, after dry ice 3 is generated on the surface of the thermally conductive film 22, the thermally conductive film 22 bulges due to the solidification and expansion of the internal phase change energy storage liquid 23, which breaks and peels off the dry ice 3.

[0026] As described above, this invention, through the cooperation of the constant-diameter channel 122 and the gradually expanding outlet 123 in the valve body assembly 1, initially suppresses flash evaporation from a hydrodynamic perspective. When flash evaporation inevitably occurs, the de-icing assembly 2, integrated in the most sensitive area of ​​the valve core 12, can autonomously and mechanically break the ice using the latent heat release and volume change of the phase change energy storage liquid 23, without requiring external energy. The synergistic effect of these two components solves the problem of blockage in the sealing ball valve of the liquid carbon dioxide delivery pipeline caused by the accumulation of dry ice 3.

[0027] To further optimize fluid properties and enhance de-icing performance, the present invention also includes a series of preferred improved features.

[0028] In a preferred embodiment, continue reading Figure 1 and Figure 2 The diameter of the upstream pipe 1113 is set to be equal to the diameter of the inlet 121 and the diameter of the channel 122. This ensures that the fluid travels through a continuous, straight pipe section of equal diameter without abrupt changes in cross-section from the upstream pipe 1113 to the channel 122 of the valve core 12, maximizing pressure stability. Simultaneously, the diameter of the outlet 123 gradually increases smoothly along the flow direction of liquid carbon dioxide. This gradual expansion structure effectively avoids vortex zones and local negative pressure zones formed by sudden expansion of the flow channel, thereby suppressing flash evaporation. The diameter of the downstream pipe 1122 is set to be larger than the diameter at the maximum point of the outlet 123. This means that the flow channel undergoes another expansion process from the outlet 123 of the valve core 12 to the downstream pipe 1122. This design allows the fluid that has already undergone pressure recovery to further decelerate and pressurize, helping to sublimate any remaining trace amounts of dry ice 3 back into a gaseous state or carry it away by the main fluid, preventing its deposition in further downstream pipes.

[0029] Regarding the specific construction of the valve seat 11, in one embodiment, the valve seat 11 includes an upstream valve seat 111 and a downstream valve seat 112. To achieve optimal sealing, structural strength, and assembly precision, the upstream valve seat 111 and downstream valve seat 112 are preferably integrally formed, meaning the entire valve seat 11 is a single cast and precision-machined part, rather than a combination of two independent parts. The upstream valve seat 111 is further subdivided into a body 1111 and a mating portion 1112. The body 1111 is the main part of the upstream valve seat 111, accommodating the upstream pipe 1113. The mating portion 1112 is integrally formed on the body 1111 at one end axially close to the valve core 12. The shape of the mating portion 1112 matches the outer peripheral contour of the inlet portion 121 of the valve core 12, and its function is to precisely and sealingly connect the outlet end of the upstream pipe 1113 to the inlet portion 121 of the valve core 12. More importantly, the internal flow channel of the mating portion 1112 is designed with a specific length and shape to stabilize the fluid pressure within the pipe. As a buffer and flow stabilization section, the docking part 1112 can eliminate turbulence or pressure pulsation that may exist in the upstream pipeline 1113, so that liquid carbon dioxide enters the channel part 122 of the valve core 12 in a more stable laminar flow state, which is very beneficial for suppressing flash evaporation.

[0030] Please combine Figure 1 The valve seat 11 also has a mounting cavity 113 inside. This mounting cavity 113 is located between the upstream valve seat 111 and the downstream valve seat 112, and is actually a spherical or near-spherical space inside the valve seat 11 with an enlarged diameter to accommodate the valve core 12. The upstream pipe 1113 and the downstream pipe 1122 are connected through this mounting cavity 113. The valve core 12 and the aforementioned docking part 1112 are both located in this mounting cavity 113. This design allows the valve core 12 to rotate freely within the mounting cavity 113, while the docking part 1112 acts as a fixed flow guiding component, extending into the mounting cavity 113 and maintaining a small but non-contact gap with the inlet part 121 of the valve core 12, or achieving sliding contact through a sealing ring, thereby maintaining a stable fluid introduction even when the valve core 12 rotates.

[0031] To ensure absolutely reliable shut-off between upstream and downstream when the valve core 12 is in the closed position, preventing leakage of high-pressure liquid carbon dioxide, the valve body assembly 1 also includes multiple seals 14. In the illustrated embodiment, the seals 14 are preferably spring-loaded sealing rings or lip seals with self-tightening function. One end of the seal 14 is fixedly disposed with the inner wall surface of the housing cavity 113 (e.g., embedded in an annular groove on the inner wall of the housing cavity 113), while the other end of the seal 14 is always in close contact with the outer spherical surface of the valve core 12. When the valve core 12 rotates to the closed position, its solid spherical surface without flow channels fits against the seal 14; when open, the inlet 121 and outlet 123 of the valve core 12 are aligned with the opening of the seal 14. This dynamic contact ensures both flexible valve rotation and reliable sealing.

[0032] In particular, the present invention has made ingenious optimizations regarding the spatial arrangement of the seal 14 and the de-icing assembly 2. For example... Figure 2 As shown, the valve core 12 has at least two layers of de-icing assemblies 2 arranged circumferentially around the channel of the valve core 12 on the side facing the downstream pipe 1122 (i.e., the outlet hemisphere of the valve core 12). Here, "circumferentially surrounding" means that the de-icing assemblies 2 are arranged in a ring around the flow channel axis of the valve core 12. "Multiple layers" refers to multiple such ring arrangements along the fluid flow direction. Each layer of de-icing assembly 2 is configured as multiple independent housings 21, which are evenly distributed circumferentially to achieve uniform coverage of the wall surface. More importantly, the depth of the housing 21 (i.e., the diameter extending from the inner wall of the valve core 12 towards the outer wall surface) is designed to gradually decrease in the direction away from the axis. That is, the housing 21 near the center line of the flow channel has a larger depth, while the housing 21 located near the seal 14 has a smaller depth. Simultaneously, the distance from the seal 14 to the rotation axis of the valve core 12 is designed to be greater than the distance from the de-icing assembly 2 to that axis. This means that all de-icing components 2 are located within the contact zone of the seal 14, closer to the center of the flow channel of the valve core 12. This layout brings significant technical benefits: First, dry ice 3 is most easily generated on the flow channel wall, and placing the de-icing components 2 in this area enables "precise de-icing"; Second, the sliding contact area of ​​the seal 14 does not have de-icing components 2, avoiding scratches or wear on the seal 14 caused by the edges of the shell 21 or the heat-conducting film 22 of the de-icing components 2, ensuring long-term sealing reliability of the valve throughout its lifespan; Third, the design of the shell 21 with a gradually changing depth allows the de-icing components 2 to adapt to the curvature changes of the valve core 12 wall, while ensuring that during phase change expansion, the heat-conducting film 22 near the center undergoes a larger bulging deformation to break the dry ice 3 in the core area, while the heat-conducting film 22 near the edge undergoes a smaller deformation, forming a gradient ice-breaking effect.

[0033] Please see Figure 3In a further optimized embodiment, the shape of the housing 21 is specially designed. The longitudinal diameter (i.e., the length along the flow direction) of the housing 21 gradually decreases along the flow direction of the liquid carbon dioxide, giving the housing 21 a streamlined projection resembling a water droplet or teardrop. Simultaneously, all edges of the housing 21 are rounded, resulting in smooth, rounded transitions. This shape offers the advantage that when the de-icing assembly 2 mechanically breaks up the ice and the heat-conducting film 22 bulges outward, the stress distribution on the heat-conducting film 22 during deformation is more uniform due to the smooth rounded edges of the opening of the housing 21 and the gradually shrinking diameter at the end of the housing 21. Furthermore, it can bend to a larger radius of curvature than a right-angled edge. A larger, smoother bulging surface can more effectively crack and peel off the thicker layers of dry ice with a larger adhesion area, thus achieving a superior de-icing effect.

[0034] The characteristic of the shell 21 gradually decreasing in diameter along the direction of liquid carbon dioxide flow not only gives it a streamlined shape to reduce flow resistance, but more importantly, it directly affects the deformation and ice-breaking ability of the heat-conducting film 22. Geometrically, for the same volume expansion, the smaller the opening diameter of the shell 21, the smaller the radius of curvature of the outward bulging deformation of the heat-conducting film 22 covered on it when it is squeezed by the solidification and expansion of the internal phase change energy storage liquid 23. That is, the greater the degree of bending, the more concentrated the peeling force and impact force exerted by the heat-conducting film 22 on the dry ice 3 attached to its surface is, thus enabling it to break the dry ice 3 more effectively and bounce it off the wall, resulting in a more significant de-icing effect. In particular, in the initial stage of valve activation, when the downstream pipe 1122 is not yet fully filled with liquid carbon dioxide, the pressure in the outlet 123 and the downstream pipe 1122 area is significantly lower than the pressure in the upstream pipe 1113. The low-pressure environment is more likely to cause flash evaporation of liquid carbon dioxide, so the risk of dry ice 3 forming in the outlet 123 area is higher, and the requirements for de-icing ability are also higher. The diameter of the housing 21 of the present invention gradually decreases along the flow direction, which means that the diameter of the housing 21 located closer to the outlet 123 is smaller, and the corresponding thermal conductive film 22 has a larger deformation curvature and stronger de-icing capability. This "adaptive" matching of structure with operating conditions enables the ball valve to have the strongest mechanical ice-breaking capability in the area where de-icing is most needed, thereby achieving a precise and efficient solution to the problem of flash dry ice 3.

[0035] Finally, please see Figure 1A pressure-guiding surface 1121 is also provided on the downstream valve seat 112. This pressure-guiding surface 1121 is located at the inlet end of the downstream pipe 1122, and its inner wall surface has an arc-shaped pressure-guiding surface 1121 along the flow direction of liquid carbon dioxide, and the diameter of the pressure-guiding surface 1121 first increases and then decreases. When liquid carbon dioxide (which may contain a small amount of gaseous carbon dioxide or dry ice particles) flows out from the outlet 123 of the valve core 12, it enters the pressure-guiding surface 1121, and the flow channel gradually narrows. According to Bernoulli's principle, the flow velocity increases and the static pressure further decreases. The design intention here is to use the instantaneous pressure drop to cause any residual, tiny dry ice particles to directly sublimate into carbon dioxide gas, avoiding the deposition of solid particles in the downstream pipe 1122. At the same time, the flow channel will immediately enter the downstream pipe 1122 with a larger diameter, the flow velocity drops sharply, the pressure recovers, and the overall safe and stable delivery state is still maintained. The smooth transition of the pressure-conducting surface 1121 ensures that this pressurization-depressurization process is smooth and free of eddies, avoiding the risk of secondary flash evaporation.

[0036] In summary, the sealing ball valve for liquid carbon dioxide delivery pipelines of the present invention systematically integrates a constant-diameter flow channel, a gradually expanding outlet 123, and an embedded de-icing assembly 2 with phase change energy storage and expansion deformation capabilities. Furthermore, it optimizes the layout of the sealing element 14, the shape of the housing 21, and the downstream pressure guiding surface 1121. This endows the ball valve with superior capabilities beyond fluid control, including actively suppressing flash evaporation and autonomously removing dry ice 3. This significantly improves the operational safety and reliability of liquid carbon dioxide delivery pipelines, demonstrating high practical value and promising industrial application prospects.

[0037] The above embodiments are merely preferred embodiments of the present invention and should not be construed as limiting the scope of protection of the present invention. Any non-substantial changes and substitutions made by those skilled in the art based on the present invention shall fall within the scope of protection claimed by the present invention.

Claims

1. A sealing ball valve for liquid carbon dioxide transfer pipelines, characterized in that, include: The valve body assembly (1) includes a valve seat (11), a valve core (12) and a valve stem (13). The valve core (12) is rotatably disposed inside the valve seat (11). The valve core (12) is fixed to one end of the valve stem (13). The other end of the valve stem (13) passes through the valve seat (11) and is rotatably connected to the valve seat (11). The valve seat (11) includes an upstream pipe (1113) and a downstream pipe (1122). The valve core (12) includes an integrally formed inlet (121), a channel (122), and an outlet (123). The inlet (121) is located upstream of the channel (122), and the outlet (123) is located downstream of the channel (122). The diameter of the outlet (123) is larger than the diameter of the channel (122), and the diameter of the channel (122) is the same as the diameter of the upstream pipe (1113). The de-icing assembly (2) is disposed on the inner wall surface of the channel portion (122) and the outlet portion (123). The de-icing assembly (2) includes a housing (21), a thermally conductive film (22) and a phase change energy storage liquid (23). The housing (21) is embedded circumferentially into the side of the channel portion (122) and the inner wall surface of the outlet portion (123). The phase change energy storage liquid (23) is disposed inside the housing (21). The thermally conductive film (22) seals and covers the opening of the housing (21).

2. The sealing ball valve for liquid carbon dioxide conveying pipelines according to claim 1, characterized in that, The diameter of the upstream pipe (1113) is equal to the diameter of the inlet (121) and the diameter of the channel (122). The diameter of the outlet (123) gradually increases along the direction of liquid carbon dioxide flow. The diameter of the downstream pipe (1122) is greater than the maximum diameter of the outlet (123).

3. The sealing ball valve for liquid carbon dioxide conveying pipelines according to claim 2, characterized in that, The valve seat (11) includes an upstream valve seat (111) and a downstream valve seat (112), the upstream valve seat (111) and the downstream valve seat (112) are integrally formed, the upstream pipe (1113) is disposed in the upstream valve seat (111), and the downstream pipe (1122) is disposed in the downstream valve seat (112); The upstream valve seat (111) includes a main body (1111) and a docking part (1112). The docking part (1112) is integrally formed on one end of the main body (1111) along the axial direction close to the valve core (12). The docking part (1112) connects the upstream pipe (1113) with the inlet part (121) and plays a role in stabilizing the fluid pressure in the pipe.

4. The sealing ball valve for liquid carbon dioxide conveying pipelines according to claim 3, characterized in that, The valve seat (11) further includes a mounting cavity (113), which is provided between the upstream valve seat (111) and the downstream valve seat (112). The valve core (12) and the docking part (1112) are both located in the mounting cavity (113), and the upstream pipe (1113) and the downstream pipe (1122) are connected through the mounting cavity (113).

5. The sealing ball valve for liquid carbon dioxide conveying pipelines according to claim 4, characterized in that, The valve body assembly (1) also includes a plurality of seals (14), one end of which is fixedly disposed with the inner wall of the mounting cavity (113), and the other end of which abuts against the outer side of the valve core (12).

6. The sealing ball valve for liquid carbon dioxide conveying pipelines according to claim 5, characterized in that, The valve core (12) is surrounded by multiple layers of the de-icing assembly (2) in the circumferential direction on the side facing the downstream pipe (1122), and each layer of the de-icing assembly (2) is provided in multiple ways. The depth of the housing (21) gradually decreases in the direction away from the axis. The distance from the seal (14) to the axis is greater than the distance from the de-icing assembly (2) to the axis.

7. The sealing ball valve for liquid carbon dioxide conveying pipelines according to claim 1, characterized in that, The diameter of the shell (21) gradually decreases along the direction of liquid carbon dioxide flow. The shell (21) is rounded around its perimeter so that when the de-icing component (2) deforms and breaks ice, the curvature of the heat-conducting film (22) is greater to achieve a better de-icing effect.

8. The sealing ball valve for liquid carbon dioxide conveying pipelines according to claim 3, characterized in that, The downstream valve seat (112) is provided with an arc-shaped pressure guiding surface (1121). Along the flow direction of liquid carbon dioxide, the diameter of the pressure guiding surface (1121) first increases and then decreases.

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