Valve rod anti-freezing structure of check valve for deep sea

Abstract

The utility model discloses a valve rod anti-freezing structure of a check valve for deep sea, which relates to the field of check valves, and adopts the technical scheme that the valve rod anti-freezing structure comprises a valve rod movably arranged on a valve body, a spiral heating channel is axially formed in the valve rod, a nichrome electric heating wire A is arranged in the heating channel, and the nichrome electric heating wire A is arranged in the valve rod. The nickel-chromium alloy electric heating wire A is connected with external heating equipment through a waterproof cable A. The valve has the advantages that a heating source is located in the valve rod, heat does not need to pass through middle structures such as the valve body and a heat preservation layer, the heat conduction path is shortened by 90% or above, and energy loss is effectively reduced; the design of the spiral heating channel enables heat to be evenly distributed in the axial direction of the valve rod, formation of a local high-temperature area is avoided, it is guaranteed that the surface temperature of the valve rod is kept within the safety range of-5 DEG C to 10 DEG C, the valve rod is prevented from being frozen, the situation that the temperature exceeds the boiling point of seawater under high pressure is avoided, and meanwhile the heating source is located in the valve rod and cannot be soaked in the seawater.

Description

Technical Field

[0001] This utility model relates to the field of check valves, and more specifically, it relates to a stem antifreeze structure for a deep-sea check valve. Background Technology

[0002] The low temperature (0-4℃) in the deep sea environment causes moisture in the medium to easily freeze on the surface of the valve stem when it comes into contact with the cold seawater, creating mechanical resistance or even freezing completely, making it impossible for the valve stem to open and close normally.

[0003] Currently, externally wrapped heating belts are mainly used to prevent valve stem freezing, which has three major drawbacks: First, low thermal efficiency, as heat must be conducted to the valve stem through multiple layers such as the valve body, insulation layer, and seals, resulting in energy loss of over 60%; second, localized overheating, with temperatures in the centralized heating area reaching over 120°C, far exceeding the boiling point of seawater under high pressure (e.g., approximately 150°C at 500 bar), easily leading to cavitation damage; and third, poor corrosion resistance, as the insulation layer of the heating belt breaks down after long-term immersion in seawater, causing a decrease in insulation resistance and a short-circuit failure rate as high as 35%.

[0004] Therefore, in order to solve the above-mentioned technical problems, this application proposes a stem antifreeze structure for a check valve used in deep sea. Utility Model Content

[0005] In view of the shortcomings of the existing technology, the purpose of this utility model is to provide a stem antifreeze structure for a check valve used in deep sea.

[0006] To achieve the above objectives, this utility model provides the following technical solution: a valve stem antifreeze structure for a deep-sea check valve, comprising a valve stem movably mounted on the valve body, wherein a spiral heating channel is provided axially inside the valve stem, and a nickel-chromium alloy electric heating wire A is provided in the heating channel, and the nickel-chromium alloy electric heating wire A is connected to an external heating device through a waterproof cable A.

[0007] Preferably, an annular shell is sealed to the outer wall of the valve stem at the part outside the valve body, and a nickel-chromium alloy electric heating wire B is sleeved on the part of the valve stem inside the annular shell, and the nickel-chromium alloy electric heating wire B is connected to an external heating device through a waterproof cable B.

[0008] Preferably, the inner wall of the spiral heating channel is coated with a metal oxide thermally conductive coating with a thickness of 0.05-0.2 mm.

[0009] Preferably, both the nickel-chromium alloy heating wire A and the nickel-chromium alloy heating wire B are equipped with temperature sensors.

[0010] Preferably, a high-sealing component is installed at the part of the valve stem through which the waterproof cable A passes and at the part of the annular shell through which the waterproof cable B passes.

[0011] Preferably, the high-sealing component includes a connecting pipe that communicates with the spiral heating channel and the interior of the annular shell, and multiple O-rings are arranged in a transverse array on the inner wall of the connecting pipe. The O-rings are connected to the waterproof cable A and the waterproof cable B by mechanical compression.

[0012] Preferably, the inner wall of the annular shell is provided with a polyurethane insulation layer with a thickness of 3-8 mm.

[0013] Compared with the prior art, the present invention has the following beneficial effects:

[0014] 1. This utility model utilizes a spiral heating channel axially opened inside the valve stem, into which a nickel-chromium alloy electric heating wire A is directly inserted. It converts electrical energy directly into heat energy by utilizing the principle of Joule heating generated by current passing through the nickel-chromium alloy. Since the heating source is located inside the valve stem, heat does not need to pass through intermediate structures such as the valve body and insulation layer, shortening the heat conduction path by more than 90% and effectively reducing energy loss. The spiral heating channel design ensures that heat is evenly distributed along the valve stem axis, preventing the formation of localized high-temperature zones and ensuring that the valve stem surface temperature is maintained within a safe range of -5℃ to 10℃. This prevents the valve stem from freezing and avoids exceeding the boiling point of seawater under high pressure. Furthermore, because the heating source is located inside the valve stem, it is not immersed in seawater, overcoming many shortcomings of the prior art's valve stem antifreeze technology using heating strips.

[0015] 2. The internal spiral heating channel and nickel-chromium alloy electric heating wire A of this utility model realize axial uniform heating of the valve stem body, while the nickel-chromium alloy electric heating wire B in the outer annular shell forms a local heat preservation barrier for the exposed section of the valve stem. This composite heating system can improve the overall temperature control accuracy of the valve stem to ±1.5℃, and can still keep the surface temperature of the valve stem stable within a safe range in a deep sea environment of -50℃.

[0016] 3. This utility model connects to waterproof cable A or waterproof cable B through 3-5 gradient compression O-rings (Shore hardness 75A), forming a dynamic sealing barrier under 0-100MPa water pressure, with a contact stress of up to 18MPa, which can withstand long-term pressure impact in the deep sea environment, thereby effectively preventing seawater from entering the annular shell and spiral heating channel. Attached Figure Description

[0017] The accompanying drawings, which are included to provide a further understanding of the present invention and form part of this application, illustrate exemplary embodiments of the present invention and, together with the description thereof, serve to explain the present invention and do not constitute an undue limitation thereof. In the drawings:

[0018] Figure 1 This is a schematic diagram of the overall structure of this utility model;

[0019] Figure 2 This utility model Figure 1 Another perspective on the specific structure;

[0020] Figure 3 This utility model Figure 2 Enlarged view of the local structure of A;

[0021] Figure 4 This is a schematic diagram of the specific structure of the spiral heating channel in this utility model;

[0022] Figure 5 This is a schematic diagram of the specific structure of the present invention after removing the annular shell, waterproof cable B, and the high-sealing component on the annular shell.

[0023] In the diagram: 1. Valve stem; 2. High-sealing assembly; 201. Connecting pipe; 202. O-ring seal; 3. Spiral heating channel; 4. Nickel-chromium alloy electric heating wire A; 5. Waterproof cable A; 6. Annular shell; 7. Nickel-chromium alloy electric heating wire B; 8. Waterproof cable B. Detailed Implementation

[0024] like Figure 1-5 As shown, this utility model provides a valve stem antifreeze structure for a deep-sea check valve, including a valve stem 1 movably mounted on the valve body. A spiral heating channel 3 is provided axially inside the valve stem 1. A nickel-chromium alloy electric heating wire A4 is installed inside the heating channel 3, and the nickel-chromium alloy electric heating wire A4 is connected to an external heating device through a waterproof cable A5.

[0025] By creating a spiral heating channel 3 axially inside the valve stem 1, a nickel-chromium alloy electric heating wire A4 is directly inserted into this channel. Utilizing the principle of Joule heating generated by current passing through the nickel-chromium alloy, electrical energy is directly converted into heat energy. Since the heating source is located inside the valve stem 1, heat does not need to pass through intermediate structures such as the valve body and insulation layer, shortening the heat conduction path by more than 90% and effectively reducing energy loss. The spiral heating channel 3 design ensures that heat is evenly distributed along the axial direction of the valve stem 1, avoiding the formation of localized high-temperature zones and ensuring that the surface temperature of the valve stem 1 is maintained within a safe range of -5℃ to 10℃. This prevents the valve stem 1 from freezing and avoids exceeding the boiling point of seawater under high pressure (e.g., below 120℃ at 500 bar). Furthermore, because the heating source is located inside the valve stem 1 and is not immersed in seawater, this structure achieves a comprehensive improvement in antifreeze efficiency, safety, and reliability through internal active and uniform heating.

[0026] Furthermore, an annular shell 6 is sealed to the outer wall of the valve stem 1 on the part outside the valve body (the part that does not enter the valve body). A nickel-chromium alloy electric heating wire B7 is sleeved on the part of the valve stem 1 inside the annular shell 6, and the nickel-chromium alloy electric heating wire B7 is connected to an external heating device through a waterproof cable B8. According to the internal spiral heating channel 3 and the nickel-chromium alloy electric heating wire A4 described above, the valve stem 1 body is axially uniformly heated, while the nickel-chromium alloy electric heating wire B7 inside the outer annular shell 6 forms a local heat insulation barrier for the exposed part of the valve stem 1. This composite heating system can improve the overall temperature control accuracy of the valve stem 1 to ±1.5℃, and can maintain the surface temperature of the valve stem 1 within a safe range even in a deep-sea environment of -50℃.

[0027] Furthermore, the inner wall of the spiral heating channel 33 is coated with a metal oxide thermally conductive coating with a thickness of 0.05-0.2mm. The thermal conductivity of the metal oxide (such as Al2O3, ZnO) coating can reach 10-300W / (m・K), which is 10-50 times that of traditional insulating materials. This allows the heat generated by the nickel-chromium alloy electric heating wire A4 to be quickly transferred to the valve stem 1 body via thermal conduction, increasing the thermal response speed by 40% and effectively reducing the heat residence time in the channel. Temperature sensors are integrated on both the nickel-chromium alloy electric heating wire A4 and the nickel-chromium alloy electric heating wire B7. The surface temperature of the heating wire is collected in real time by the temperature sensors (accuracy ±0.5℃). Combined with the temperature field model of the valve stem 1 body, the heating power is dynamically adjusted to improve the surface temperature control accuracy of the valve stem 1 to ±1℃, avoiding local overheating (such as limiting the peak temperature of the heating wire to below 120℃) and effectively suppressing cavitation damage. The inner wall of the annular shell 6 is provided with a thickness of 3-8mm. The polyurethane insulation layer has a thermal conductivity of only 0.02-0.03 W / (m·K), which can improve the heat transfer efficiency from the nickel-chromium alloy electric heating wire B7 to the valve stem 1 body by 45%, while reducing heat loss to the seawater environment by 30%.

[0028] It should be noted that waterproof cables A5 and B8 are made of ethylene propylene rubber, which has excellent water resistance, aging resistance, and electrical insulation properties, effectively preventing seawater from seeping in and affecting the cable insulation. The sheath layer can use neoprene rubber, which has excellent resistance to seawater corrosion and ozone aging, as well as good mechanical strength and flame retardancy.

[0029] High-sealing components 2 are installed at the points on valve stem 1 where waterproof cable A5 passes through and on annular shell 6 where waterproof cable B8 passes through. The high-sealing components 2 include a connecting pipe 201 that communicates with the spiral heating channel 3 and the interior of annular shell 6. Multiple O-rings 202 are arranged in a transverse array on the inner wall of the connecting pipe 201. The O-rings 202 are connected to waterproof cables A5 and B8 by mechanical compression. Thus, through the connection of 3-5 graded-compression O-rings 202 with waterproof cables A5 or B8 (Shore hardness 75A), a dynamic sealing barrier is formed under 0-100MPa water pressure, with a contact stress of up to 18MPa. This can withstand long-term pressure impacts in deep-sea environments, effectively preventing seawater from entering annular shell 6 and spiral heating channel 3.

[0030] The connecting pipe 201 is made of titanium alloy (Ti-6Al-4V) and forms galvanic corrosion protection with the 316L stainless steel valve stem 1. The sealing ring is made of perfluoroether rubber (FFKM) with 0.8wt% nano zinc oxide added. After soaking in seawater at pH 3-11 for 5000 hours, the volume expansion rate is <0.5%.

[0031] The above description is merely a preferred embodiment of this utility model and is not intended to limit the utility model in any way. Those skilled in the art can readily implement this utility model based on the accompanying drawings and the above description. However, any modifications, alterations, or equivalent variations made by those skilled in the art without departing from the scope of the utility model's technical solution, utilizing the disclosed technical content, are considered equivalent embodiments of this utility model. Furthermore, any equivalent changes, alterations, or variations made to the above embodiments based on the essential technology of this utility model are still within the protection scope of this utility model's technical solution.

Claims

1. A valve stem antifreeze structure for a deep-sea check valve, comprising a valve stem (1) movably mounted on the valve body, characterized in that: The valve stem (1) has a spiral heating channel (3) axially arranged inside. A nickel-chromium alloy electric heating wire A (4) is installed in the heating channel (3), and the nickel-chromium alloy electric heating wire A (4) is connected to an external heating device through a waterproof cable A (5).

2. The stem antifreeze structure of a deep-sea check valve according to claim 1, characterized in that: The outer wall of the valve stem (1) is sealed with an annular shell (6) on the part of the valve body. The valve stem (1) is fitted with a nickel-chromium alloy electric heating wire B (7) inside the annular shell (6). The nickel-chromium alloy electric heating wire B (7) is connected to an external heating device through a waterproof cable B (8).

3. The stem antifreeze structure of a deep-sea check valve according to claim 1, characterized in that: The inner wall of the spiral heating channel (3) is coated with a metal oxide thermally conductive coating with a thickness of 0.05-0.2 mm.

4. The stem antifreeze structure of a deep-sea check valve according to claim 2, characterized in that: Temperature sensors are integrated on both the nickel-chromium alloy electric heating wire A (4) and the nickel-chromium alloy electric heating wire B (7).

5. The stem antifreeze structure of a deep-sea check valve according to claim 2, characterized in that: High-sealing components (2) are installed on the valve stem (1) where the waterproof cable A (5) passes through, and on the annular shell (6) where the waterproof cable B (8) passes through.

6. The stem antifreeze structure of a deep-sea check valve according to claim 5, characterized in that: The high-sealing component (2) includes a connecting pipe (201) that is interconnected with the spiral heating channel (3) and the annular shell (6). Multiple O-rings (202) are arranged in a horizontal array on the inner wall of the connecting pipe (201). The O-rings (202) are connected to the waterproof cable A (5) and the waterproof cable B (8) by mechanical compression.

7. The stem antifreeze structure of a deep-sea check valve according to claim 2, characterized in that: The inner wall of the annular shell (6) is provided with a polyurethane insulation layer with a thickness of 3-8 mm.

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