An electrode plate for dehydrating high-water-content crude oil and its usage method

Abstract

The present invention relates to an electrode plate for dehydrating high-water-content crude oil and a method for using the same. It includes a plate body and a voltage conversion device. The plate body is composed of a central conductor layer, a semiconductor sub-outer layer, and an insulating outer layer arranged in sequence from the inside to the outside. The central conductor layer and the semiconductor sub-outer layer are both encapsulated in the insulating outer layer. The voltage conversion device is arranged on one side of the plate body. The input end of the voltage conversion device is connected to an external cable, and its output end penetrates the insulating outer layer of the plate body and is connected to the central conductor layer. In the plate body of this technical solution, the semiconductor sub-outer layer is used as the intermediate medium between the insulating outer layer and the central conductor layer. During the electro-dehydration process, the insulating outer layer can be protected from being broken down, ensuring the generation of a stable electric field. At the same time, the voltage conversion device is located in the electro-dehydration equipment, that is, the place of voltage conversion is transferred from the outside to the inside of the equipment, eliminating high-voltage power transmission and greatly improving the safety of the entire electro-dehydration process.

Description

Technical Field

[0001] The present invention relates to the technical field of crude oil electro-dehydration, and more specifically, to an electrode plate for dehydrating high-water-content crude oil and a method for using the same. Background Art

[0002] Emulsified crude oil is a direct extract during the crude oil extraction process. Emulsified crude oil often contains a large amount of water. Therefore, it is necessary to dehydrate the crude oil. During the dehydration process, sewage, impurities, etc. are separated from the oil-water emulsified crude oil, so that the volume of the emulsified crude oil is continuously reduced and the purity is continuously increased, and finally high-quality commercial oil is obtained.

[0003] Electro-dehydration is the most commonly used method for crude oil dehydration using a crude oil electro-dehydration device. It is achieved by the action of the high-voltage electric field force generated by the electrode plate in the crude oil electro-dehydration device. Specifically, during the dehydration process, the emulsified crude oil is placed in a high-voltage direct current or alternating current electric field generated by the electrode plate. By using the action of the electric field on the water droplets in the crude oil, the water droplets are deformed and an electrostatic force is generated. Under the action of the electrostatic force, the moving speed of the water droplets increases and the kinetic energy increases. Furthermore, the emulsification film on the surface of the emulsified crude oil is continuously impacted, so that the mechanical strength of the emulsification film is reduced until it breaks, and the high-speed moving water droplets are promoted to coalesce with each other into water droplets with larger particle sizes. With the help of the oil-water density difference, they settle from the crude oil under the action of gravity to achieve separation.

[0004] Therefore, the electrode plate group is the core component that generates the electric field in the crude oil electro-dehydration device. The main body of the electrode plate group in the crude oil electro-dehydration device is generally a metal plate made of metal. During dehydration, it is immersed in the emulsified crude oil and is in direct contact with the emulsified crude oil. However, it is found in the actual production process that due to the strong conductivity of the emulsified crude oil with a high water content, when a high voltage is applied to the metal plate, the leakage current between the positive electrode metal plate and the negative electrode metal plate will increase, causing a short circuit. Therefore, there are certain safety hazards, and at the same time, the electric field formed between the metal plates is damaged, resulting in the inability of the water droplets in the emulsified crude oil to effectively coalesce, affecting the final oil-water separation effect.

[0005] In order to enable the water droplets in the emulsified crude oil to coalesce sufficiently and reduce the potential safety hazards during the dehydration process, a Chinese patent with the publication number CN203904275U and the patent name "An electrode plate for a crude oil electro-dehydrator" discloses a new type of electrode plate. Specifically, it consists of a steel wire rope with an insulating layer, an insulating support plate, and a fixed spacing rod. The steel wire rope with an insulating layer is composed of a steel wire rope and an insulating layer coated on the outer surface of the steel wire rope. An insulating support plate is provided on each side of the electrode plate. The steel wire rope with an insulating layer is coiled in an S shape at a certain interval between these two insulating support plates. Adjacent sections of the steel wire rope with an insulating layer are parallel. A fixed spacing rod is arranged parallel to them in the middle. The two ends of the steel wire rope with an insulating layer are exposed and connected to the metal exposed points of the high-voltage power introduction pipe of the crude oil electro-dehydrator, and the connection points are sealed with insulating materials.

[0006] The electrode plate for the crude oil dehydration equipment with the above structure uses a steel wire rope as the conductive medium, and an insulating layer is coated on the surface of the steel wire rope. The insulating layer can effectively prevent leakage current from being generated between the electrode plate and the inner wall of the tank of the upper crude oil electro-dehydrator, the upper metal electrode plate, the inner wall of the tank of the lower crude oil electro-dehydrator, or the lower metal electrode plate, and between each section of the steel wire rope with an insulating layer in the electrode plate and the adjacent fixed spacing rod. It solves the problem of easy short-circuit and forms a stable electric field to ensure the oil-water separation effect. However, it has certain deficiencies. First, when a high voltage is applied to the steel wire rope with an insulating layer, the curvature at the turning end of the steel wire rope as the conductive medium is relatively large. Therefore, a large amount of charges are likely to accumulate at the interface between the steel wire rope and the insulating layer at this place, causing tip discharge and breaking through the insulating layer, destroying the protection provided by the insulating layer and resulting in short-circuit. In addition, the high voltage applied to the metal plate is input from the outside through an external wire cable. The external wire cable often has problems such as being damaged due to external forces or aging during long-term use, resulting in electric leakage during high-voltage power transmission. Therefore, there are still great potential safety hazards during the crude oil electro-dehydration process. Summary of the Invention

[0007] In view of the above situation, to overcome the problems existing in the existing electrode plates for electro-dehydration equipment, such as the insulating layer at the turning end of the steel wire rope as the conductive medium being easily broken through, the electric field being unstable, and there being a risk of electric leakage when using external high-voltage power transmission, resulting in great potential safety hazards during the crude oil electro-dehydration process, the purpose of the present invention is to provide an electrode plate for electro-dehydration equipment and its usage method with a reasonable overall structure, which can not only ensure the stability of its own structure when a high voltage is applied, but also generate a stable electric field when in contact with emulsified crude oil, and can convert the voltage inside the equipment, thus having excellent safety.

[0008] To achieve the above purpose, the technical solution of the present invention is:

[0009] An electrode plate for dehydrating high-water-content crude oil, which comprises a plate body and a voltage conversion device. The plate body is composed of a central conductor layer, a semiconductor sub-outer layer and an insulating outer layer arranged in sequence from inside to outside. The central conductor layer and the semiconductor sub-outer layer are both enclosed in the insulating outer layer. The voltage conversion device is arranged on one side of the plate body. The input end of the voltage conversion device is electrically connected to an external wiring cable connected to an AC power supply, and its output end penetrates through the insulating outer layer of the plate body and is connected to the central conductor layer.

[0010] Preferably, the material of the central conductor layer is metal.

[0011] Preferably, the semiconductor sub-outer layer is a coating structure, which is coated on the surface of the central conductor layer.

[0012] Preferably, the semiconductor sub-outer layer is an anti-static semiconductor coating structure.

[0013] Preferably, the material of the insulating outer layer is epoxy resin, and the whole is formed into an integral body by vacuum casting.

[0014] Preferably, the material of the insulating outer layer is fluorine material, and the whole is formed into an integral body by die casting.

[0015] Preferably, the voltage conversion device includes a transformer, a protective housing and a conductive rod. The transformer is arranged in the protective housing. The conductive rod is arranged at one end of the protective housing and passes through the protective housing to be connected to the output end of the transformer, and at the same time it penetrates through the insulating outer layer of the plate body and is connected to the central conductor layer. The external wiring cable penetrates through the other end of the protective housing and is connected to the transformer.

[0016] Preferably, a voltage monitoring module is further arranged at the output end of the transformer, and the voltage monitoring module has a voltage feedback circuit.

[0017] Preferably, the protective housing includes a sleeve body, a positioning end cover and a wiring end cover. The positioning end cover and the wiring end cover are respectively arranged at the front and rear ends of the sleeve body. The sleeve body has the same material as the insulating outer layer and is formed into an integral body with the insulating outer layer by casting or die casting. A clamping groove opposite to the conductive rod is opened on the positioning end cover, and it is clamped on the plate body through the clamping groove. A wiring hole for the external wiring cable to pass through is opened on the wiring end cover.

[0018] A method for using the above electrode plate, which comprises the following steps:

[0019] S1: Arrange a plurality of plate bodies with voltage conversion devices side by side at intervals, and connect each voltage conversion device through an external wiring cable connected to an external AC power supply;

[0020] S2: Release the emulsified crude oil to be electrically dehydrated, so that each plate body is immersed in the emulsified crude oil to be treated;

[0021] S3: The low-voltage electricity is transmitted by an external AC power supply to a voltage conversion device through an external cable, converted into high-voltage electricity, and then applied to the central conductor layer of the corresponding plate body, forming an AC electric field around the plate body to perform electro-dehydration on the emulsified crude oil in the way of oscillating coalescence.

[0022] Compared with the prior art, the advantages of the present invention are as follows:

[0023] (1) The semiconductor sub-outer layer is located between the outer insulating layer and the central conductor layer as an intermediate medium. When high-voltage electricity is applied to the plate body, an electric field is formed around the plate body. Due to the characteristics of the semiconductor sub-outer layer material, the binding effect of its atomic nucleus on electrons is stronger than that of the central conductor layer. Compared with the central conductor layer which only has a small amount of movable free electrons, it is not easy to cause a high degree of charge aggregation, thus preventing the direct wrapping of the outer insulating layer outside the metal conductor and avoiding the problems of tip discharge and insulation layer breakdown caused by charge aggregation, and ensuring the generation of a stable electric field and improving the oil-water separation effect.

[0024] (2) The voltage conversion device is located in the electro-dehydration equipment together with the plate body, that is, the place of voltage conversion is transferred from the outside to the inside of the equipment. The external cable only transmits low-voltage electricity, eliminating high-voltage power transmission, so the safety of the entire electro-dehydration process is greatly improved. Even if problems such as electric leakage occur, the harm to surrounding equipment and personnel can be reduced. Description of the Drawings

[0025] Figure 1 is the overall structural schematic diagram of the electrode plate of the present invention;

[0026] Figure 2 is the partial cross-sectional structural schematic diagram of the plate body of the electrode plate of the present invention;

[0027] Figure 3 is the structural schematic diagram when the plate body of the electrode plate and the voltage conversion device of the present invention are disassembled;

[0028] Figure 4 is the overall structural schematic diagram of the voltage conversion device of the electrode plate of the present invention;

[0029] Figure 5 is the present invention Figure 4 magnified structural schematic diagram of part A;

[0030] Figure 6 is the disassembled structural schematic diagram of the electrode plate of the present invention.

[0031] As shown in the figure:

[0032] 1. Plate body; 101. Central conductor layer; 102. Semiconductor sub-outer layer; 103. Insulating outer layer; 2. Voltage conversion device; 201. Transformer; 202. Conductive rod; 202a. Conductive groove; 203. Sleeve; 204. Positioning end cap; 204a. Card slot; 205. Wiring end cap; 205a. Wiring hole; 206. Threaded fastener. Detailed implementation mode

[0033] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0034] In the description of the present invention, it should be noted that the orientation or positional relationship indicated by the terms "upper", "lower", "left", "right", "inner", "outer", etc. is based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship in which the product of the present invention is usually placed during use. It is only for the convenience of simplifying the description, rather than indicating or implying that the orientation must have a specific orientation and specific orientation structure and operation. Therefore, it should not be construed as a limitation of the present invention. Embodiment 1:

[0035] As Figures 1 to 3 and Figure 6As shown in the figure, an electrode plate for dehydrating high-water-content crude oil includes a plate body 1 and a voltage conversion device 2. The plate body 1 is composed of a central conductor layer 101, a semiconductor sub-outer layer 102, and an insulating outer layer 103. The central conductor layer 101 is located at the center of the plate body 1. The semiconductor sub-outer layer 102 is located outside the central conductor layer 101 and wraps around the central conductor layer 101. The insulating outer layer 103 is located outside the semiconductor sub-outer layer 102. There is a chamber in the insulating outer layer 103 for accommodating the semiconductor sub-outer layer 102 and the central conductor layer 101. Both the semiconductor sub-outer layer 102 and the central conductor layer 101 are located in the chamber, so that the insulating outer layer 103 wraps around the semiconductor sub-outer layer 102 and the central conductor layer 101. During the operation of the crude oil electro-dehydration equipment configured with the insulating electrode plate of the present invention, under the action of the insulating layer, the electrode plates are insulated from each other, avoiding the short-circuit problem caused by the direct contact between the central conductor layer 101 in the plate body 1 and the emulsified crude oil. Generally speaking, the semiconductor sub-outer layer 102 is located between the insulating outer layer 103 and the central conductor layer 101 as an intermediate medium. When high voltage is applied to the plate body 1, an electric field is formed around the plate body 1. Due to the characteristics of the material of the semiconductor sub-outer layer 102, the binding force of its atomic nucleus to electrons is stronger than that of the central conductor layer 101. Compared with the central conductor layer 101 which has only a small amount of movable free electrons, it is not easy to cause a high concentration of charges, thus preventing the direct wrapping of the insulating outer layer 103 outside the central conductor layer 101 and avoiding the problem of tip discharge and breakdown of the insulating layer caused by charge accumulation. This enables the semiconductor sub-outer layer 102 to form a good protection for the insulating outer layer 103 and ensure the generation of a stable electric field, improving the effect of oil-water separation. In addition, the voltage conversion device 2 is provided on one side of the plate body 1 for converting high and low voltages. The input end of the voltage conversion device 2 is electrically connected to the external wiring cable connected to the AC power supply. The output end of the voltage conversion device 2 penetrates the insulating outer layer 103 of the plate body 1 and is connected to the central conductor layer 101. The low voltage output by the external AC power supply is transmitted to the voltage conversion device 2 through the external wiring cable. After being converted into high voltage by the voltage conversion device 2, it can be directly applied to the central conductor layer 101 of the plate body 1 to form an AC electric field for electro-dehydrating the emulsified crude oil in the way of oscillating coalescence. Since the voltage conversion device 2 is connected to the plate body 1, during installation, the voltage conversion device 2 is located in the electro-dehydration equipment together with the plate body 1, that is, the place of voltage conversion is transferred from the outside to the inside of the equipment. The external wiring cable only transmits low voltage, eliminating high-voltage power transmission, so the safety of the entire electro-dehydration process is greatly improved. Even if problems such as electric leakage occur, the damage to surrounding equipment and personnel can be reduced.

[0036] Furthermore, in the present invention, the material of the central conductor layer 101 is a metal used as a natural conductor, such as a copper plate.

[0037] Such asFigure 2 As shown, in the present invention, the semiconductor sub-outer layer 102 is a coating structure, which is coated on the surface of the central conductor layer 101.

[0038] Furthermore, the semiconductor sub-outer layer 102 is an anti-static semiconductor coating structure, which can reduce the generation of static electricity and improve the safety of crude oil electro-dehydration production.

[0039] Furthermore, the material of the outer insulating layer 103 is epoxy resin, and it is integrally formed by casting. The epoxy resin blank flows into the cavity of the specified mold for forming. By using the vacuum casting method, the air bubbles remaining between the outer insulating layer 103 and the internal central conductor layer 101 can be eliminated, thereby ensuring the uniform density of the plate body 1 and significantly improving its structural strength and sealing performance.

[0040] As Figure 1 and Figures 3 to 6 shown, the voltage conversion device 2 includes a transformer 201, a protective housing, and a conductive rod 202. The transformer 201 is the core component for converting high and low voltages of the voltage conversion device 2. The transformer 201 is arranged in a relatively closed protective housing and is protected by the protective housing to reduce interference from factors such as external object impacts. The conductive rod 202 is made of a metal material. It is arranged at one end of the protective housing and passes through the protective housing to be connected to the output end of the transformer 201. At the same time, it penetrates through the outer insulating layer 103 of the plate body 1 to be connected to the central conductor layer 101. More specifically, a conductive groove 202a is provided at the end of the conductive rod 202 away from the transformer 201, and the central conductor layer 101 of the plate body 1 is inserted into the conductive groove 202a. After the transformer 201 converts the low voltage into a high voltage, it is applied to the central conductor layer 101 of the plate body 1 through the conductive rod 202, so as to generate an electric field around the plate body 1. The external wiring cable penetrates through the other end of the protective housing and is connected to the transformer 201 for transmitting the low voltage to the transformer 201.

[0041] Furthermore, a voltage monitoring module is also provided at the output end of the transformer 201. The voltage monitoring module has a voltage feedback circuit. The voltage feedback circuit is used to detect the voltage between the electrode plates of the present invention configured in the crude oil electro-dehydration equipment in real time. When the voltage between two adjacent electrode plates is abnormal, the operation of the transformer 201 is automatically cut off to avoid safety accidents caused by abnormal voltage.

[0042] As Figure 1 and Figures 3 to 6As shown in the figure, the protective housing includes a sleeve body 203, a positioning end cover 204, and a wiring end cover 205. The positioning end cover 204 and the wiring end cover 205 are respectively arranged at the front and rear ends of the sleeve body 203, and together with the sleeve body 203, they form a relatively enclosed space. The sleeve body 203 is made of the same material as the outer insulating layer 103 and is integrally formed with the outer insulating layer 103 by casting or die-casting. The specific forming process depends on the material of the outer insulating layer 103. The sleeve body 203 is connected to the outer insulating layer 103 through an extension part formed on its outer wall. The extension part can increase the stability of the sleeve body 203 relative to the position of the plate body 1. A card slot 204a opposite to the conductive rod 202 is opened on the positioning end cover 204, and it is clamped on the plate body 1 through the card slot 204a, and then a secondary connection is made in an insertion and mating manner. It can be understood that after passing through the card slot 204a, the conductive rod 202 is connected to the central conductor layer 101 in the plate body 1. A wiring hole 205a for the external wiring cable to pass through is opened on the wiring end cover 205.

[0043] As Figure 1 , Figure 3 , Figure 4 and Figure 6 shown, the transformer 201 and the sleeve body 203 are detachably fixed by a threaded fastener 206. Based on the quick-disassembly characteristics of the threaded connection method, it is convenient to disassemble and assemble the transformer 201 located in the protective housing for maintenance and replacement. Embodiment 2:

[0044] This embodiment makes one of the optimized designs on the basis of Embodiment 1. The material of the outer insulating layer 103 is a fluorine material, such as tetrafluoroethylene, etc. The whole outer insulating layer 103 made of fluorine material is integrally formed by die-casting. The fluorine material blank enters the cavity of a specific mold under external pressure for forming.

[0045] The present invention also relates to a use method of the above electrode plate, which includes the following steps:

[0046] S1: Arrange a plurality of plate bodies 1 with voltage conversion devices 2 in parallel at intervals, and electrically connect them to the wiring holes 205a of the wiring end covers 205 of each voltage conversion device 2 through an external wiring cable connected to an external AC power supply;

[0047] S2: Release the emulsified crude oil to be de-electrified, so that each plate body 1 is immersed in the emulsified crude oil to be treated;

[0048] S3: The external AC power supply transmits low-voltage electricity to the voltage conversion device 2 through the external wiring cable, converts it into high-voltage electricity through the transformer 201 in the sleeve body 203, and then applies it to the central conductor layer 101 of the corresponding plate body 1 through the conductive rod 202, forming an alternating current electric field around the plate body 1, and then the emulsified crude oil can be de-electrified by the way of oscillating coalescence, and the water content of the emulsified crude oil.

[0049] See Figures 1 to 6 Combined with Embodiment 1 and Embodiment 2, when the electrode plate of the present invention is configured in a crude oil electro-dehydration device to dehydrate emulsified crude oil, the conversion of high and low voltages is realized by the transformer 201 in the voltage conversion device 2 provided on one side of the plate body 1. The external connecting cable only transmits low voltage electricity, eliminating high voltage power transmission. Therefore, the safety of the entire crude oil electro-dehydration process is greatly improved. Even if problems such as electric leakage occur, the damage to surrounding equipment and personnel can be reduced. Since the outer surface of the plate body 1 is an insulating outer layer 103, the internal central conductor layer 101 is isolated from the external emulsified crude oil. Therefore, no leakage current will be generated between the plate bodies 1 of adjacent electrode plates, and short circuits will not occur. At the same time, the central conductor layer 101 is coated with a semiconductor sub-outer layer 102, and the middle is the intermediate medium. The semiconductor sub-outer layer 102 forms a protection for the insulating outer layer 103, preventing the insulating outer layer 103 from being broken down due to the charge accumulation on the central conductor layer 101, realizing the protection of the insulating outer layer 103 and extending the service life of the electrode plate.

[0050] The above embodiments and the descriptions in the specification only illustrate the principles and the best embodiments of the present invention. Without departing from the spirit and scope of the present invention, the present invention will have various changes and improvements, and these changes and improvements all fall within the scope of the present invention claimed.

Claims

1. An electrode plate for dehydrating high water - cut crude oil, characterized in that, it comprises a plate body (1) and a voltage conversion device (2). The plate body (1) is composed of a central conductor layer (101), a semiconductor sub - outer layer (102) and an insulating outer layer (103) which are arranged in sequence from the inside to the outside. The central conductor layer (101) and the semiconductor sub - outer layer (102) are both encapsulated in the insulating outer layer (103). The voltage conversion device (2) is arranged on one side of the plate body (1). The input end of the voltage conversion device (2) is electrically connected to an external wire cable connected to an AC power supply, and its output end penetrates through the insulating outer layer (103) of the plate body (1) and is connected to the central conductor layer (101). The semiconductor sub - outer layer (102) is a coating structure and is coated on the surface of the central conductor layer (101). The voltage conversion device (2) comprises a transformer (201), a protective housing and a conductive rod (202). The transformer (201) is arranged in the protective housing. The conductive rod (202) is arranged at one end of the protective housing and passes through the protective housing to be connected to the output end of the transformer (201), and at the same time, it penetrates through the insulating outer layer (103) of the plate body (1) and is connected to the central conductor layer (101). The external wire cable penetrates through the other end of the protective housing and is connected to the transformer (201).

2. The electrode plate for dehydrating high water - cut crude oil according to claim 1, characterized in that, the material of the central conductor layer (101) is metal.

3. The electrode plate for dehydrating high water - cut crude oil according to claim 1, characterized in that, the semiconductor sub - outer layer (102) is an anti - static semiconductor coating structure.

4. The electrode plate for dehydrating high water - cut crude oil according to claim 1, characterized in that, the material of the insulating outer layer (103) is epoxy resin, and the whole is formed into an integral body by vacuum casting.

5. The electrode plate for dehydrating high water - cut crude oil according to claim 1, characterized in that, the material of the insulating outer layer (103) is fluorine material, and the whole is formed into an integral body by die - casting.

6. The electrode plate for dehydrating high water - cut crude oil according to claim 1, characterized in that, a voltage monitoring module is further arranged at the output end of the transformer (201), and the voltage monitoring module has a voltage feedback circuit.

7. The electrode plate for dehydrating high water - cut crude oil according to claim 1, characterized in that, The protective housing includes a sleeve body (203), a positioning end cover (204), and a wiring end cover (205). The positioning end cover (204) and the wiring end cover (205) are respectively arranged at the front and rear ends of the sleeve body (203). The sleeve body (203) is made of the same material as the outer insulating layer (103) and is integrally formed with the outer insulating layer (103) by casting or die-casting. A clamping groove (204a) opposite to the conductive rod (202) is formed on the positioning end cover (204), and the clamping groove (204a) is used to clamp onto the plate body (1). A wiring hole (205a) for an external wiring cable to pass through is formed on the wiring end cover (205).

8. A method for using the electrode plate according to any one of claims 1-7, characterized in that, it comprises the following steps: S1: Arrange a plurality of plate bodies (1) with voltage conversion devices (2) side by side at intervals, and electrically connect each voltage conversion device (2) through an external wiring cable connected to an external AC power supply; S2: Release the emulsified crude oil to be de-electrified, so that each plate body (1) is immersed in the emulsified crude oil to be treated; S3: The external AC power supply transmits low-voltage electricity through the external wiring cable to the voltage conversion device (2), converts it into high-voltage electricity, and then applies it to the central conductor layer (101) of the corresponding plate body (1), forming an AC electric field around the plate body (1), and performing electric dehydration on the emulsified crude oil in a way of oscillating coalescence.

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