Explosion-proof and flame-proof transformer oil tank and preparation method thereof

Abstract

The invention discloses an explosion-proof and flame-proof transformer oil tank and a preparation method thereof, and belongs to the technical field of transformer manufacturing, the explosion-proof and flame-proof transformer oil tank comprises an oil tank body, a plurality of pieces of reinforcing iron are fixed on the periphery of the oil tank body, at least one piece of reinforcing iron is connected with the oil tank body through a pipeline group, and an explosion-proof film is arranged at the joint of the pipeline group and the oil tank body; the reinforcing iron connected with the oil tank body through the pipeline set is filled with nitrogen. The explosion-proof membrane is installed on the oil tank and connected with the reinforcing iron on the oil tank, the reinforcing iron is filled with nitrogen, pressure can be rapidly released to prevent explosion, the nitrogen isolates high-temperature oil and high-temperature gas from making contact with oxygen, and therefore fire disasters are avoided.

Description

Technical Field

[0001] The invention belongs to the technical field of transformer manufacturing, and particularly relates to an explosion-proof and flame-proof transformer oil tank and a preparation method thereof. Background Art

[0002] After a transformer has been in operation for a long time, the insulating material gradually loses its insulating properties due to electrical, thermal and chemical effects. Insulation failure may cause a short circuit between windings and the back winding to the ground, generating electric arcs and high temperatures, decomposing the insulating oil to produce a large amount of flammable gas. The flammable gas and oil vapor cause the pressure inside the oil tank to rise rapidly. When the pressure exceeds the mechanical strength of the oil tank, a physical explosion occurs. The sprayed high-temperature oil mist mixed with air may cause a fire or even a secondary explosion.

[0003] The oil tank is a crucial component of a transformer, serving as the housing for the entire transformer assembly and playing a crucial role within the transformer. The tank must possess reliable strength, capable of withstanding mechanical strength tests in a vacuum and at one atmospheric pressure. It must be free of damage and unacceptable permanent deformation, and must meet both the negative pressure of vacuum oil filling and the positive pressure during operation. However, when a fault occurs within the transformer, arcing and high temperatures can occur, decomposing the insulating oil and generating large amounts of flammable gases. These gases and oil vapors rapidly increase the internal pressure of the tank, creating a pressure shock that can cause the tank to rupture. When the high-temperature transformer oil comes into contact with oxygen, it can also cause fires or even secondary explosions. Summary of the Invention

[0004] The present invention provides an explosion-proof and flame-proof transformer oil tank and a preparation method thereof, which can quickly relieve pressure in the oil tank to prevent explosion and avoid the occurrence of fire.

[0005] In order to achieve the above object, the present invention adopts the following technical solutions: In a first aspect, the present invention provides an explosion-proof and flame-proof transformer oil tank, comprising an oil tank body and a reinforcing iron, wherein the reinforcing iron is fixed to the outer surface of the oil tank body and together with the outer wall of the oil tank body forms a closed cavity, at least one of the reinforcing irons is connected to the oil tank body through a pipe group, and the cavity formed by the reinforcing iron and the oil tank body is filled with nitrogen, and an explosion-proof membrane is provided at the connection between the pipe group and the oil tank body.

[0006] A further improvement of the present invention is that the pipeline group includes a first pipeline and a second pipeline arranged up and down.

[0007] A further improvement of the present invention is that the pipeline group and the oil tank body are connected by two flanges, and a sealing gasket is provided between the two flanges.

[0008] A further improvement of the present invention is that the fuel tank body comprises four fuel tank side walls welded end to end in sequence, the lower ends of the four fuel tank side walls are welded to the fuel tank bottom, and the upper ends are sealed to the tank cover.

[0009] A further improvement of the present invention is that reinforcing plates are connected between the upper and lower ends of the reinforcing iron and the oil tank body.

[0010] A further improvement of the present invention is that the reinforcing iron is fixed to the outside of the fuel tank body by welding, thereby increasing the strength of the fuel tank.

[0011] A further improvement of the present invention is that the rigidity of the reinforcing iron is greater than or equal to the rigidity of the fuel tank body.

[0012] In a second aspect, the present invention provides a method for preparing an explosion-proof and flame-proof transformer oil tank, comprising the following steps: S1. According to the design drawings, two first through holes are formed on the side wall of the fuel tank body, corresponding to the positions where the pipe assembly will be installed later, and flanges are welded to the first through holes; S2. Open two second through holes on the reinforcing iron that is required to serve as the pressure relief cavity, and weld flanges at the second through holes; S3, welding each of the reinforcing irons to the outer surface of the corresponding side wall of the fuel tank body; S4. Weld the side walls together and weld them to the bottom of the fuel tank to make the fuel tank body; S5. Use a flange to connect one end of the pipe assembly to the explosion-proof membrane and the fuel tank body, and connect the other end of the pipe assembly to the reinforcing iron; S6. Evacuate the inner cavity of the reinforcing iron and inject nitrogen, then install the fuel tank cover; S7. Perform a sealing test on the transformer oil tank.

[0013] A further improvement of the present invention is that in step S5, the two flanges are first connected to the oil tank body and the pipeline respectively, and then the explosion-proof membrane and the sealing gasket are placed between the two flanges, and the two flanges are fixedly connected with fasteners.

[0014] A further improvement of the present invention is that in step S6, the amount of nitrogen injected is such as to enhance the pressure balance inside and outside the iron.

[0015] Compared with the prior art, the present invention has at least the following beneficial technical effects: The present invention aims to install an explosion-proof membrane on the fuel tank, connecting it to a reinforced iron section on the tank. The reinforced iron section is filled with nitrogen. When the pressure inside the transformer tank exceeds the limit, the membrane opens under the pressure, rapidly releasing the pressure in the tank and preventing explosion. Simultaneously, the nitrogen in the reinforced iron section isolates the high-temperature oil and gases from oxygen, thus preventing fire. The pressure relief space and nitrogen storage cavity utilize the existing reinforced iron section in the fuel tank. Functional cavities are constructed within the reinforced iron section or by adhering to its structural contours, transforming redundant, non-pressure-bearing space into functional space. This achieves "structure-function" integration without increasing the overall size of the fuel tank, requiring no additional components and adding virtually no weight to the transformer. Furthermore, the reinforced iron section itself acts as a high-stress area that resists tank deformation. Integrating the pressure relief cavity within or adjacent to the reinforced iron section significantly improves local pressure-bearing capacity. This multifunctional integration is achieved without adding new materials, changing the main process flow, or sacrificing reliability, perfectly aligning with the trend toward high-density, low-cost manufacturing, and maintenance-free transformer designs. This structure is easy to install, has obvious effects, and is both technologically groundbreaking and economically feasible.

[0016] The number of explosion-proof membranes and the number of connecting reinforcement irons are set according to calculations.

[0017] Furthermore, reinforcing plates are connected between the upper and lower ends of the reinforcing iron and the fuel tank body. The reinforcing plates increase the contact area between the reinforcing body and the fuel tank wall, optimize stress distribution, improve connection reliability and extend fatigue life.

[0018] Furthermore, the reinforcing iron is fixed to the fuel tank body by welding to enhance the strength of the fuel tank. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 This is a front view of an explosion-proof and flame-proof transformer oil tank of the present invention; Figure 2 This is a side view of an explosion-proof and flame-proof transformer oil tank of the present invention; Figure 3 This is a flow chart of a method for preparing an explosion-proof and flame-proof transformer oil tank provided by the present invention.

[0020] In the attached figure: 1. Transformer oil; 2. Explosion-proof membrane; 3. Nitrogen; 4. Oil tank reinforcement iron; 5. Oil tank side wall; 6. First pipeline; 7. Second pipeline. DETAILED DESCRIPTION

[0021] The present invention will be described in detail below with reference to the accompanying drawings and specific embodiments.

[0022] In order to enable those skilled in the art to better understand the technical solutions of the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings of the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts should fall within the scope of protection of the present invention.

[0023] It should be noted that when an element is referred to as being "disposed on" another element, it may be directly on the other element or there may be another element centered thereon. When an element is considered to be "connected" to another element, it may be directly connected to the other element or there may be another element centered thereon at the same time. The terms "upper", "lower", "front", "back", "left", "right", "top", "bottom", "inside", "outside", etc. used herein indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0024] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which this invention pertains. The terms used herein in the specification of the present invention are for the purpose of describing specific embodiments only and are not intended to limit the present invention. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0025] Reference Figure 1 The invention discloses an explosion-proof and flame-proof transformer oil tank, in which the wall of the transformer oil tank is connected to a portion of the reinforcing iron 4 by a pipe, an explosion-proof membrane 2 is installed at the connection of the reinforcing iron 4, and nitrogen is filled in the cavity formed by the reinforcing iron 4 and the side wall of the oil tank. The present invention utilizes the original reinforcing iron 4 on the transformer oil tank to provide an expansion space. At this time, in addition to the elastic deformation of the oil tank, an expansion space is provided, which can effectively reduce the pressure shock borne by the oil tank and prevent the oil tank from bursting. When the internal pressure of the transformer is too high, the pressure causes the explosion-proof membrane 2 to open, quickly reducing the internal pressure of the transformer oil tank. Nitrogen quickly fills the transformer oil tank through the pipe to separate the oil and explosives from the air, preventing the explosion from further expanding, thereby improving the safety of the transformer. Nitrogen also isolates high-temperature oil and high-temperature gas from contact with oxygen, thereby avoiding the occurrence of fire.

[0026] Example 1 Reference Figure 1 and Figure 2A flameproof and explosion-proof transformer oil tank includes an oil tank body, an explosion-proof membrane 2, a reinforcing iron 4, a first pipe 6 and a second pipe 7.

[0027] The fuel tank body includes four fuel tank side walls 5 welded end to end in sequence. The lower ends of the four fuel tank side walls 5 are welded to the fuel tank bottom, and the upper ends are sealed to the tank cover.

[0028] Several parallel reinforcements 4 are fixed to the outer surface of the fuel tank sidewall 5. The reinforcements 4 are strip-shaped shells fixed to the fuel tank sidewall 5 and form a cavity with the fuel tank sidewall 5. The reinforcements 4 connected to the fuel tank body through the pipe group are denoted as reinforcements A. The thickness of the reinforcements 4 is greater than or equal to the thickness of the fuel tank body. Among them, there are two reinforcements 4 on the front fuel tank sidewall connected to the fuel tank body through the pipe group, and there are two reinforcements 4 on the rear fuel tank sidewall connected to the fuel tank body through the pipe group. These four reinforcements connecting the pipes are arranged diagonally; an explosion-proof membrane 2 is provided at the connection between the pipe group and the fuel tank body; and the cavity formed by these four reinforcements 4 and the fuel tank sidewall is filled with nitrogen.

[0029] Optionally, the fuel tank side wall 5 and the reinforcing iron 4 are fixed by welding.

[0030] Optionally, the pipeline group includes a first pipeline 6 and a second pipeline 7, and the first pipeline 6 and the second pipeline 7 are arranged side by side up and down, and the spacing is adjusted according to actual conditions.

[0031] A group of through holes are opened in the fuel tank side wall 5 where the explosion-proof membrane needs to be installed, including two first through holes arranged up and down. The reinforcing iron side wall A also has a group of through holes, including second through holes arranged up and down. The distance D1 between the two first through holes is equal to the distance D2 between the two second through holes.

[0032] A flange is attached to the first end of the first pipe 6. Another flange is attached to the first through-hole in the fuel tank sidewall 5. The explosion-proof membrane 2 and the sealing gasket are installed between the two flanges and bolted together. The second end of the first pipe 6 is also flanged to the second through-hole. A flange is attached to the first end of the second pipe 7. Another flange is attached to the second through-hole in the fuel tank sidewall 5. Another explosion-proof membrane 2 and the sealing gasket are installed between the two flanges and bolted together. The second end of the second pipe 7 is also flanged to the second through-hole.

[0033] Optionally, a trapezoidal reinforcing plate is connected between the upper and lower ends of the reinforcing iron 4 and the oil tank body, and the reinforcing plate is larger at the top and smaller at the bottom.

[0034] In other embodiments, the number of explosion-proof membranes and the number of connecting reinforcement irons are set according to calculations and are not necessarily four, but can also be one, two, three, five, etc.

[0035] Example 2 This embodiment provides an explosion-proof and flame-proof transformer oil tank, including an oil tank body, an explosion-proof membrane 2, reinforcing iron 4, a first pipe 6 and a second pipe 7.

[0036] The fuel tank body is identical to that of Example 1. Several parallel reinforcements 4 are fixed to the outer surface of the tank body. These reinforcements 4 are strip-shaped shells welded to the tank sidewalls 5 to form a cavity. The thickness of the reinforcements 4 is equal to or greater than the thickness of the tank body. Three reinforcements 4 are connected to the tank body via a pipe assembly on the front sidewall, and three reinforcements 4 are connected to the tank body via a pipe assembly on the rear sidewall. These six reinforcements are arranged diagonally. An explosion-proof membrane 2 is installed at the junction of the pipe assembly and the tank body. The cavity formed by these six reinforcements 4 and the tank sidewalls is filled with nitrogen.

[0037] Optionally, the outer surface of the fuel tank body is coated with a flame retardant coating.

[0038] Example 3 Reference Figure 3 This embodiment provides a method for preparing an explosion-proof and flame-proof transformer oil tank, comprising the following steps: S1. Select high-quality low-carbon structural steel plates to make the tank sidewalls, tank bottom and tank cover. The thickness of the steel plates is determined according to the tank size, pressure and strength requirements. Suitable channel steel is selected to make the reinforcement iron. Low-carbon steel has good weldability, workability and toughness, and can effectively withstand the mechanical stress, internal pressure and vacuum load during transformer operation and transportation. S2. According to the design drawings, several groups of first through holes are opened in the side wall of the fuel tank body, each group of first through holes including two first through holes arranged one above the other, and flanges are welded to the first through holes; the first through holes are used to connect the pipe group to the fuel tank body; S3. Open two second through holes on the side wall of the reinforcing iron 4 that needs to serve as the pressure relief cavity, and weld flanges at the first through holes. The two second through holes are arranged up and down, and their positions correspond to the two first through holes. S4. Weld the prepared reinforcement iron 4 on the side wall of the fuel tank body in sequence; S5, welding the fuel tank side walls 5 together in sequence and welding them to the fuel tank bottom, performing post-weld treatment to obtain the fuel tank body; S6. Use flanges to connect one end of the first pipe 6 to the explosion-proof membrane 2 and the fuel tank body: First, connect the two flanges to the fuel tank sidewall 5 and the first pipe 6 respectively. Then, place the explosion-proof membrane 2 and the sealing gasket between the two flanges and secure the two flanges together with fasteners. Connect the other end of the first pipe 6 to the reinforcing iron 4. Use the same method to connect the second pipe, the reinforcing iron 4, the explosion-proof membrane 2, and the fuel tank sidewall. S7, evacuate the inner cavity of the reinforcing iron 4, exhaust the air, and then inject nitrogen, the amount of nitrogen injected making the pressure inside and outside the reinforcing iron 4 balanced; S8. Surface cleaning and painting: Thoroughly clean the inner and outer surfaces of the tank body and the tank cover to remove scale, rust, welding slag, oil stains and other impurities, and spray anti-rust primer, mid-coat and topcoat in sequence; S9. Install the tank cover on the fuel tank body; S10. Perform a sealing test on the entire transformer tank.

[0039] Example 4 This embodiment provides an oil-immersed transformer, which includes: Transformer oil tank: The explosion-proof and flame-proof transformer oil tank of Example 1 or 2 is used to house the transformer body (including the core, windings, etc.) and the insulating cooling oil. This oil tank forms the transformer's outer shell, directly bearing the internal pressure and isolating it from the external environment.

[0040] Transformer body: fixedly installed inside the oil tank, including electromagnetic conversion components such as iron core, high-voltage winding, and low-voltage winding.

[0041] Transformer oil: filled in the oil tank and immersed in the transformer body, mainly plays the role of insulation and heat dissipation.

[0042] Heat dissipation device: connected to the fuel tank body to enhance heat dissipation capacity.

[0043] Bushing: Installed on the tank cover or tank wall, used to safely lead the winding lead to the external circuit while ensuring the sealing of the tank.

[0044] Protection and monitoring components: including but not limited to gas relay (installed on the connecting pipe between the oil tank and the oil conservator), thermometer, oil level gauge, etc., used to monitor the operating status of the transformer in real time and take action in case of abnormality.

[0045] Oil conservator: connected to the top of the oil tank through a pipe, used to compensate for the volume expansion and contraction of the insulating oil due to temperature changes, reduce the contact area between oil and air, and accommodate the gas precipitated from the oil.

[0046] Since the oil-immersed transformer of this embodiment integrates the explosion-proof and flame-proof transformer oil tank of the aforementioned embodiment, it necessarily has all the significant technical advantages and beneficial effects brought by the oil tank, mainly including: 1) Significantly Improved Explosion-Proof Safety: The cavity formed by the reinforced iron and the tank sidewall 5 can quickly release the enormous internal pressure generated by faults (such as arcing), effectively preventing catastrophic physical explosions (such as rupture or fragmentation) in the tank, ensuring personal and equipment safety.

[0047] 2) Enhanced fire retardant performance: The flame retardant coating applied to the outer surface of the fuel tank can significantly delay or inhibit the spread of flames on the tank surface when encountering external fire sources or high temperatures caused by internal faults, reducing the risk of fire and the possibility of ignition of adjacent equipment.

[0048] 3) Excellent mechanical strength and stability: The optimized rib layout and selected high-strength materials, combined with effective post-weld stress relief treatment (such as vibration aging), ensure that the tank has sufficient rigidity and strength to withstand internal pressure, vacuum negative pressure, transportation vibration, lifting stress, and electromagnetic forces during operation, effectively resisting permanent deformation, ensuring structural integrity and long-term operational reliability.

[0049] In summary, the oil-immersed transformer of this embodiment, by adopting the aforementioned innovative explosion-proof and flame-proof transformer oil tank, not only realizes the basic functions of the oil-immersed transformer, but also substantially improves its ability to cope with internal fault pressure and resist external fire threats without increasing the volume of the transformer.

[0050] The term "consisting of" when describing a combination should include the identified elements, ingredients, components, or steps as well as other elements, ingredients, components, or steps that do not materially affect the basic novel characteristic of the combination. The use of the terms "comprising" or "including" to describe a combination of elements, ingredients, components, or steps herein also contemplates embodiments consisting essentially of these elements, ingredients, components, or steps. The use of the term "may" herein is intended to indicate that any of the attributes described as "may" be optional.

[0051] Multiple elements, ingredients, parts or steps can be provided by a single integrated element, ingredient, part or step. Alternatively, a single integrated element, ingredient, part or step can be divided into separate multiple elements, ingredients, parts or steps. The disclosure of "a" or "an" to describe an element, ingredient, part or step is not intended to exclude other elements, ingredients, parts or steps.

[0052] It should be understood that the above description is for illustrative purposes only and is not intended to be limiting. Many embodiments and many applications beyond the examples provided will be apparent to those skilled in the art upon reading the above description. Therefore, the scope of the present teachings should not be determined with reference to the above description, but rather with reference to the preceding claims and the full scope of equivalents to which such claims are entitled. For the purpose of completeness, all articles and references, including disclosures of patent applications and publications, are incorporated herein by reference. The omission of any aspect of the subject matter disclosed herein from the preceding claims is not a disclaimer of such subject matter, nor should it be considered that the applicants did not consider such subject matter to be part of the disclosed inventive subject matter.

Claims

1. An explosion-proof and flame-proof transformer oil tank, characterized in that: The invention comprises a fuel tank body and a reinforcing iron (4), wherein the reinforcing iron (4) is fixed to the outer surface of the fuel tank body and forms a closed cavity together with the outer wall of the fuel tank body, at least one of the reinforcing irons (4) is connected to the fuel tank body through a pipe group, and the cavity formed by the reinforcing iron (4) and the fuel tank body is filled with nitrogen, and an explosion-proof membrane (2) is provided at the connection between the pipe group and the fuel tank body.

2. The explosion-proof and flame-proof transformer oil tank according to claim 1, characterized in that: The pipeline group comprises a first pipeline (6) and a second pipeline (7) arranged vertically.

3. The explosion-proof and flame-proof transformer oil tank according to claim 1, characterized in that: The pipeline group and the oil tank body are connected through two flanges, and a sealing gasket is provided between the two flanges.

4. The explosion-proof and flame-proof transformer oil tank according to claim 1, characterized in that: The fuel tank body comprises four fuel tank side walls (5) welded end to end in sequence, wherein the lower ends of the four fuel tank side walls (5) are welded to the fuel tank bottom, and the upper ends are sealed to the tank cover.

5. The explosion-proof and flame-proof transformer oil tank according to claim 1, characterized in that: Reinforcement plates are connected between the upper and lower ends of the reinforcing iron (4) and the oil tank body.

6. The explosion-proof and flame-proof transformer oil tank according to claim 1, characterized in that: The reinforcing iron (4) is fixed to the outside of the fuel tank body by welding, thereby increasing the strength of the fuel tank.

7. The explosion-proof and flame-proof transformer oil tank according to claim 1, characterized in that: The stiffness of the reinforcing iron (4) is greater than or equal to the stiffness of the fuel tank body.

8. A method for preparing an explosion-proof and flame-proof transformer oil tank according to any one of claims 1 to 7, characterized in that: The following steps are involved: S1. According to the design drawings, two first through holes are formed on the side wall of the fuel tank body, corresponding to the positions where the pipe assembly will be installed later, and flanges are welded to the first through holes; S2, opening two second through holes on the reinforcing iron (4) which is required to serve as a pressure relief cavity, and welding flanges at the second through holes; S3, welding each of the reinforcing irons (4) to the outer surface of the corresponding side wall of the oil tank body; S4. Weld the side walls together and weld them to the bottom of the fuel tank to make the fuel tank body; S5. Use a flange to connect one end of the pipe group to the explosion-proof membrane (2) and the oil tank body, and connect the other end of the pipe group to the reinforcing iron (4); S6. Evacuate the inner cavity of the reinforcing iron (4) and inject nitrogen, and install the oil tank cover; S7. Perform a sealing test on the entire transformer tank.

9. The method for preparing an explosion-proof and flame-proof transformer oil tank according to claim 8, characterized in that: In step S5, the two flanges are first connected to the oil tank body and the pipeline respectively, and then the explosion-proof membrane (2) and the sealing gasket are placed between the two flanges, and the two flanges are fixedly connected with fasteners.

10. The method for preparing an explosion-proof and flame-proof transformer oil tank according to claim 8, characterized in that: In step S6, the amount of nitrogen injected is such as to enhance the pressure balance inside and outside the iron (4).

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