A high-voltage direct-heating electric boiler

Abstract

A high-voltage direct-heating electric boiler comprises an insulated shell, a refractory insulating barrel, electric heating wires, ventilation ducts, an air distribution structure, heat exchange components, a circulating fan, an inner cavity, an outer cavity, a thermal insulation structure, a circulating fan cooling system, and an insulating foundation. The refractory insulating barrel, mounted on the insulating foundation, and the electric heating wire mounted on it, perfectly solves the problems of uneven heat dissipation in high-voltage applications and the heating element. The refractory insulating barrel, which supports the heating element, is designed as a thin-shell cavity structure with mutual support in a cylindrical or polygonal shape. This reduces the weight of the refractory insulating barrel material used to support the heating element, allowing the refractory insulating barrel structure to withstand earthquakes of magnitude 7. By setting up two cavity structures, an inner and an outer one, the uniformity of hot air convection by the circulating fan is enhanced, efficiently heating the heating medium inside the heat exchange components and meeting the user's heating needs.

Description

Technical Field

[0001] This utility model relates to the field of electric boiler technology, specifically a high-voltage direct-heating electric boiler that can be directly powered by a 10kV to 110kV power supply. Background Technology

[0002] Electric boilers on the market are divided into two main types: direct-heating and thermal storage. Compared with thermal storage electric boilers, direct-heating electric boilers have the advantages of smaller footprint and lower investment cost. However, their disadvantage is that they cannot fully utilize peak and off-peak electricity pricing policies to store heat energy during cheap periods; the electricity consumption period and heating period must be synchronized. Direct-heating electric boilers are generally low-voltage boilers, and the vast majority use electric heating pipe heating mode. Due to the influence of insulation performance, their operating voltage is basically between 0.2kV and 0.69kV. This voltage level is further limited by the capacity of low-voltage transformers, so the maximum power of a single unit is unlikely to exceed 2000kW. If the heat demand is large, multiple low-voltage transformers and supporting low-voltage electrical facilities are required, increasing both electrical investment costs and the failure rate during operation and maintenance. Therefore, it is necessary to develop a direct-heating electric boiler that can use 10kV, 35kV, 66kV, or even 110kV power supply to meet the needs of users with large heat demand, limited installation space, insufficient investment funds, or no peak and off-peak electricity pricing policies. Summary of the Invention

[0003] In view of the above technical requirements, the purpose of this utility model is to provide a high-voltage direct-heating electric boiler, which aims to solve the problems of existing direct-heating electric boilers that use electric heating control mode, have limited power supply, and require multiple transformer devices when the heat demand is large, resulting in an increased failure rate. The present invention provides a safer, more stable, more efficient, smaller footprint, larger capacity and better economy direct-heating electric boiler.

[0004] To achieve the above objectives, the present invention adopts the following technical solution: This utility model provides a high-voltage direct-heating electric boiler, including an insulated shell, a fire-resistant insulated barrel, an electric heating wire, a heat exchange assembly, and a circulating fan; The thermal insulation shell consists of an external metal support structure and an internal fire-resistant thermal insulation material. The fire-resistant insulating barrel is a cylindrical structure made of fire-resistant insulating material, which is set inside the heat-insulating shell and is enclosed by a circle or polygon. The interior forms an inner cavity, and the exterior forms an outer cavity with the heat-insulating shell. Multiple ventilation channels that connect the inner cavity and the outer cavity are evenly opened on the fire-resistant insulating barrel. A circulating air duct is also provided between the inner and outer cavities, and a circulating fan is installed on the circulating air duct. The electric heating wire is made into a spiral or serpentine shape, and is installed inside the ventilation duct of the fire-resistant and insulating barrel. The heat exchange component is a heat-resistant metal pipe installed in the outer cavity. One end of the heat exchange component is connected to port A, and the other end is connected to port B.

[0005] Furthermore, the operating voltage of high-voltage direct-heating electric boilers is 10kV to 110kV.

[0006] Furthermore, the high-voltage direct-heating electric boiler also includes an air distribution structure, which is set inside the refractory insulation barrel. The cone-shaped structure is made of refractory insulation material, with the tip of the cone pointing towards the inside of the refractory insulation barrel and is coaxially installed with the refractory insulation barrel and arranged opposite to the air inlet of the circulating air duct.

[0007] Furthermore, the inner cavity is connected to the fire-resistant and insulating barrel body on its vertical side, and its two end faces are connected to the air distribution structure and the air inlet, respectively. A guide plate is provided inside the air inlet side.

[0008] Furthermore, the high-voltage direct-heating electric boiler also includes an insulating base, which is set at the bottom of the refractory insulating barrel and is made of high-temperature resistant electrical ceramics and magnesium-based refractory material with a content of 92%. A heat insulation structure is also provided between the insulating base and the refractory insulating barrel.

[0009] Furthermore, the heat exchange component is a metal tubular structure with heat exchange fins on the heat exchange tube, and the heating medium flows inside the heat exchange tube.

[0010] Furthermore, the high-voltage direct-heating electric boiler also includes a circulating fan cooling system, which is installed on the circulating fan and connected to the drive shaft.

[0011] Furthermore, the electric heating wire forms a connection structure within the refractory insulating barrel, with heating wire connection wire A and heating wire connection wire B connected to its two ends respectively.

[0012] Furthermore, the heating medium is any one of heat transfer oil, water, molten salt, and steam.

[0013] The technical solution adopted in this utility model has the following advantages: This technical solution perfectly solves the problems of high-voltage insulation and uneven heat dissipation of the heating wire by installing a fire-resistant insulating barrel on an insulating base and then mounting the heating wire on the fire-resistant insulating barrel. The fire-resistant insulating barrel, which supports the heating wire, is designed as a thin-shell cavity structure with mutual support formed by cylinders or polygons. This reduces the weight of the fire-resistant insulating barrel material used to support the heating wire. When the weight of the fire-resistant insulating barrel material used is less than 10 kg / kW or even less than 5 kg / kW, the fire-resistant insulating barrel structure can still withstand an earthquake of magnitude 7. The interior of the fire-resistant insulating barrel is designed as an axially symmetrical cavity, with a wind-equalizing structure set on the axis of symmetry. This ensures that the circulating air blowing towards the wind-equalizing structure is evenly distributed to each ventilation channel, achieving stable and uniform heat dissipation of the heating wire. Simultaneously, the refractory insulated barrel and the heat-insulating shell together form two cavities, inner and outer. Forced convection by a circulating fan ensures continuous air circulation. As air flows through the ventilation channels of the refractory insulated barrel, it absorbs heat energy from the electric heating wires, generating high-temperature air. This air then exchanges heat with the heat exchange components, heating the heating medium inside the components to meet the user's heating needs. This structure achieves the advantages of a direct-heating electric boiler: small footprint, high operating voltage, low manufacturing cost, and strong heat output capacity. It also possesses the ability to produce superheated steam, meeting users' heating demands for high-power direct-heating electric boilers. Attached Figure Description

[0014] The above and other objects, features, and advantages of the present invention will become readily understood by reading the following detailed description of exemplary embodiments with reference to the accompanying drawings. In the drawings, several embodiments of the present invention are shown by way of example and not limitation, with the same or corresponding reference numerals denoteing the same or corresponding parts, wherein: Figure 1 This is a schematic diagram of the structure of Scheme 1 of this utility model; Figure 2 This is a schematic cross-sectional view of the heat exchange component of this utility model; Figure 3 This is a schematic diagram of the second embodiment of the present invention; Figure 4 This is a schematic diagram of the horizontal ring structure of this utility model.

[0015] Explanation of icon numbers: 1. Insulated shell, 2. Fire-resistant insulated barrel, 3. Electric heating wire, 3-1. Heating wire connection A end, 3-2. Heating wire connection B end, 4. Ventilation duct, 5. Air distribution structure, 6. Inner cavity, 7. Outer cavity, 8. Thermal insulation structure, 9. Insulation base, 10. Circulating fan, 10-1. Circulating fan cooling system, 11. Circulating air duct, 12. Heat exchange component, 12-1. Heat exchange tube, 12-2. Heat exchange fins, 12-3. Heat exchange component connection A port, 12-4. Heat exchange component connection B port, 13. Heating medium, 14. Heating medium drive pump, 15. Heat exchanger, 15-1. High temperature air duct, 16. Guide plate, 17. Air inlet, 18. Horizontal ring. Detailed Implementation

[0016] Exemplary embodiments of the present disclosure will now be described in more detail with reference to the accompanying drawings. While exemplary embodiments of the present disclosure are shown in the drawings, it should be understood that the present disclosure may be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the disclosure to those skilled in the art. Unless otherwise specified, the techniques used in the embodiments are conventional means well known to those skilled in the art.

[0017] It should be noted that, unless otherwise stated, the technical or scientific terms used in this invention should be understood in their ordinary sense by those skilled in the art to which this invention pertains. In this document, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. The terms "connection," "linked," etc., should be interpreted broadly, for example, referring to a fixed connection, a detachable connection, or an integral connection; a mechanical connection or an electrical connection; a direct connection or an indirect connection via an intermediate medium. The terms "comprising," "including," or any other variations thereof are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising..." does not exclude the presence of additional identical elements in the process, method, article, or apparatus that includes said element.

[0018] This embodiment provides a high-voltage direct-heating electric boiler. Figure 1 This is a schematic diagram of Scheme 1, where the heat exchange component 12 is located within the outer cavity 7 of the insulation shell 1. For example... Figure 1As shown, the direct-heating electric boiler mainly consists of an insulated shell 1, a refractory insulating barrel 2, an electric heating wire 3, a ventilation duct 4, an air distribution structure 5, a heat exchange component 12, a circulating fan 10, an inner cavity 6, an outer cavity 7, a thermal insulation structure 8, a circulating fan cooling system 10-1, and an insulating base 9. The insulated shell 1 is composed of an external metal support structure and an internal aluminum silicate-based insulation material, connected to the refractory insulating barrel 2 via the outer cavity 7. The refractory insulating barrel 2 is a cylindrical structure made of refractory insulating material with a thickness between 0.1m and 0.5m, with ventilation ducts 4, set on the thermal insulation structure 8 connected to the insulating base 9. It is a circular or polygonal structure with ventilation ducts 4, forming an inner cavity 6 and an outer cavity 7 between itself and the insulated shell. The electric heating wire 3 is a spiral or serpentine electric heating alloy wire and electric heating alloy flat strip, set inside the ventilation ducts 4 of the refractory insulating barrel 2. The heat exchange component 12 is a refractory insulating alloy wire and flat strip set inside the outer cavity 7. A hot metal pipe is connected at one end to port A 12-3 of the heat exchange component and at the other end to port B 12-4 of the heat exchange component. A circulating fan 10 is located at the bottom of the refractory insulating barrel, with one end connected to the insulation structure 8 and the air inlet 17 via the circulating fan cooling system 10-1, and the other end connected to the circulating air duct 11. An insulating base 9 is made of high-temperature resistant electrical ceramics and magnesium-based refractory material with a content of over 92%. An air distribution structure 5 is a cone-shaped body made of refractory insulating material located inside the refractory insulating barrel 2, with the tip of the cone pointing inwards and coaxially installed with the refractory insulating barrel 2. An inner cavity 6 is connected to the refractory insulating barrel 2 on its vertical surface, and its two end faces are connected to the air distribution structure 5 and the air inlet 17 respectively. A guide plate 16 is installed inside the air inlet 17. The air inlet 17 and the guide plate 16 are made of refractory insulating material. A ventilation duct 4 is provided during the installation of the refractory insulating barrel 2. The heat exchange assembly 12 is a metal pipe with heat exchange fins. A circulating fan 10 is provided with a circulating fan cooling system 10-1. An electric heating wire 3 forms a connection structure within the fire-resistant insulated casing 2, with its two ends connected to heating wire connection line A end 3-1 and heating wire connection line B end 3-2, respectively. The heating medium 13 is a flowable substance such as heat-conducting oil, water, molten salt, or steam, and is connected to the heat exchange assembly 12 via a pump 14 driven by the heating medium and the heat exchange assembly connection port A 12-3.

[0019] Figure 2 The figure shows a cross-sectional schematic diagram of the heat exchange component 12. The heat exchange component 12 is a finned tube structure composed of heat exchange tube 12-1 and heat exchange fins 12-2, forming a spiral structure, and the heating medium 13 flows inside the tube.

[0020] Figure 3This is a schematic diagram of Scheme 2. The main difference from Scheme 1 is that the heat exchanger 15 is set outside the insulation shell 1. The heat exchanger 15 is connected to the outer cavity 7 through the high-temperature air duct 15-1, and the other end is connected to the circulating fan 10. The circulating fan 10 is then connected to the inner cavity 6 through the circulating air duct 11. The air distribution structure 5 is set on the bottom insulation structure 8. The guide plate 16 and the air inlet 17 are set at the connection between the circulating fan 10 and the insulation shell 1. The heating medium 13 is connected to the heat exchanger 15 through the heating medium driving pump 14.

[0021] The electrical connection method of a high-voltage direct-heating electric boiler is as follows: The maximum withstandable safe voltage of the heating wire connection wire A end 3-1 and heating wire connection wire B end 3-2 of each high-voltage direct-heating electric boiler is approximately 20208V (i.e., 35kV / If the connection is a 35kV electrical line, each 35kV line should be equipped with 3 direct-heating electric boilers. The heating wire connection line A-end 3-1 of the three devices should be connected to the A, B, and C phases of the 35kV line respectively, and the heating wire connection line B-end 3-2 of the three devices should be connected together. The 10kV A, B, and C phase power supply can be set on a fire-resistant insulated barrel 2. If the connection is an electrical line above 35kV, multiple sets of devices need to be configured for voltage division. That is, on the A, B, and C phases of the power supply line, according to the voltage level, multiple devices need to be connected in series in each phase so that the voltage difference between the heating wire connection line A-end 3-1 and the heating wire connection line B-end 3-2 of each device is less than 20-208V.

[0022] A high-voltage direct-heating boiler structure includes an internal refractory insulating cylinder 2, which can be manufactured as a circular columnar structure, or a square or polygonal columnar structure, depending on the actual working conditions. Based on the shape of the refractory insulating cylinder 2, the heat exchange assembly 12 is also correspondingly processed into a circular, square, or polygonal spiral structure. The outer circumference of the refractory insulating cylinder 2 is between 1m and 8m, and the height is between 2m and 7m. Ventilation channels 4 are arranged horizontally on the outer surface of the refractory insulating cylinder 2 at intervals of 0.1m to 0.15m, forming a horizontal ring 18 with equally spaced holes enclosed by the ventilation channels 4. The structure of the horizontal ring 18 is as follows: Figure 4As shown, the fire-resistant insulating barrel 2 is arranged with multiple layers of equally spaced horizontal rings at intervals of 0.065m to 0.1m along its height direction, forming an array of ventilation channels 4 on the outer surface of the fire-resistant insulating barrel 2. Heating wires 3 are processed into spiral or serpentine shapes, with one wire per horizontal ring. The length of each wire is determined by multiplying the number of holes on the horizontal ring of the fire-resistant insulating barrel 2 in that layer by the thickness of the fire-resistant insulating barrel 2. One end of this section of heating wire 3 is inserted from the outer cavity 7 through the ventilation channel 4 into the inner cavity 6, and then from the inner cavity 6 into the adjacent horizontal ventilation channel 4 in a clockwise direction. This serpentine pattern is repeated to insert the heating wire 3 into the ventilation channel 4 of the horizontal ring in that layer. After the heating wire 3 is installed in the ventilation channel 4 of each horizontal ring, each heating wire 3 on the fire-resistant insulating barrel 2 is connected in series to form a group. One end is connected to heating wire connection wire A end 3-1, and the other end is connected to heating wire connection wire B end 3-2.

[0023] The barrel adopts a frustum-shaped structure that is wider at the bottom and narrower at the top. Furthermore, when the weight of the materials used to make the refractory and insulating barrel is less than 10 kg / kW or even less than 5 kg / kW, the refractory and insulating barrel structure can still withstand an earthquake of magnitude 7.

[0024] The heating process of a high-voltage direct-heating electric boiler is as follows: When heat output is required, the external power supply system connects the heating wire connection line A end 3-1 and the heating wire connection line B end 3-2 to supply power to the equipment, so that the electric heating wire 3 is energized and heated. The air in the inner cavity 6 and the outer cavity 7 is in a positive pressure zone and the outer cavity 7 is in a negative pressure zone under the action of the circulating fan 10. Under the action of positive pressure, the air in the inner cavity 6 can flow to the outer cavity 7 through the ventilation duct 4 of the fireproof insulating barrel 2. When flowing through the ventilation duct 4, it is heated by the electric heating wire 3 inside the air duct 4, forming high-temperature air that enters the outer cavity 7. During the air flow, it comes into contact with the heat exchange component 12 set in the outer cavity 7 and exchanges heat, heating the heating medium 13 in the heat exchange tube 12-1. The air after heat exchange and cooling enters the circulating air duct 11 and enters the inner cavity 6 again under the action of the circulating fan 10, repeating the above heating and heat exchange process, converting the high-pressure input electrical energy into heat energy and outputting it to the heat user. The heat exchange fins 12-2 in the heat exchange assembly 12 mainly improve the heat exchange capacity of the heat exchange assembly 12. Inside the inner cavity 6, the air distribution structure 5 at the top and the air inlet 17 and guide plate 16 at the connection between the insulation structure 8 and the circulating fan 10 reduce turbulence in the air entering the inner cavity 6 and allow it to flow more evenly to the outer cavity 7 through the ventilation duct 4. The heating medium 13 drives the pump 14, connects to the heat exchange assembly 12 via the heat exchange assembly connection port A 12-3, exchanges heat through the heat exchange assembly 12 to raise its temperature, and then delivers it to the heat user via the heat exchange assembly connection port B 12-4. The heat exchange assembly 12 can be used as a steam injection boiler to output wet steam, or it can output superheated steam, hot water, hot air, thermal oil, molten salt, and other fluid media.

[0025] The heating process of Scheme 2 of a high-voltage direct-heating electric boiler is as follows: When heat output is required, the external power supply system connects the heating wire connection line A end 3-1 and the heating wire connection line B end 3-2 to supply power to the equipment, so that the electric heating wire 3 is energized and heated. The air in the inner cavity 6 and the outer cavity 7 is in a positive pressure zone and the outer cavity 7 is in a negative pressure zone under the action of the circulating fan 10. Under the action of positive pressure, the air in the inner cavity 6 flows to the outer cavity 7 through the ventilation channel 4 of the fireproof insulating barrel 2. When flowing through the ventilation channel 4, it is heated by the electric heating wire 3 inside the air duct 4 of the installation device, forming high-temperature air that enters the outer cavity 7. Hot air in the outer cavity 7 enters the heat exchanger 15 through the high-temperature air duct 15-1. Under the heat exchange of the heat exchanger 15, the heating medium 13 circulating inside is heated. The cooled air then enters the circulating air duct 11 and, under the action of the circulating fan 10, re-enters the inner cavity 6, repeating the heating and heat exchange process to convert electrical energy into heat energy for the heat user. Inside the inner cavity 6, the air distribution structure 5 on the bottom insulation structure 8, and the air inlet 17 and guide plate 16 located at the connection between the circulating fan 10 and the insulation shell 1, reduce turbulence in the air entering the inner cavity 6 and allow it to flow more evenly to the outer cavity 7 through the ventilation duct 4. The heating medium 13 is connected to the heat exchanger 15 via the heating medium drive pump 14. After heat exchange and temperature increase through the heat exchanger 15, it is delivered to the heat user. Each high-voltage direct-heating electric boiler needs to be equipped with multiple heat exchangers 15 to meet the user's needs based on the heat supply requirements. The heat exchangers 15 can be combined with the steam drum to output saturated steam, or they can output superheated steam, hot water, hot air, heat transfer oil, molten salt and other fluid media.

[0026] The above description is merely a specific embodiment of this utility model, but the protection scope of this utility model is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in this utility model should be included within the protection scope of this utility model. Therefore, the protection scope of this utility model should be determined by the protection scope of the claims.

Claims

1. A high-voltage direct-heating electric boiler, characterized in that, The high-voltage direct-heating electric boiler includes an insulated shell (1), a fire-resistant insulated barrel (2), an electric heating wire (3), a heat exchange assembly (12), and a circulating fan (10). The thermal insulation shell (1) is composed of an external metal support structure and an internal fire-resistant thermal insulation material; The fire-resistant insulating barrel (2) is a cylindrical structure made of fire-resistant insulating material, which is set inside the heat-insulating shell (1) and formed by a circle or polygon. It forms an inner cavity (6) inside and an outer cavity (7) between the outer cavity and the heat-insulating shell (1). Multiple ventilation channels (4) that connect the inner cavity (6) and the outer cavity (7) are evenly opened on the fire-resistant insulating barrel (2). A circulating air duct (11) is provided between the inner cavity (6) and the outer cavity (7), and a circulating fan (10) is provided on the circulating air duct (11). The electric heating wire (3) is an electric heating alloy wire or electric heating alloy flat strip made into a spiral or serpentine shape and is set inside the ventilation channel (4) of the fireproof insulating barrel (2); The heat exchange component (12) is a heat-resistant metal pipe installed in the outer cavity (7), with a heat exchange component connection port A (12-3) at one end and a heat exchange component connection port B (12-4) at the other end.

2. A high-voltage direct-heating electric boiler according to claim 1, characterized in that, The operating voltage of a high-voltage direct-heating electric boiler is 10kV to 110kV.

3. A high-voltage direct-heating electric boiler according to claim 1, characterized in that, The high-voltage direct-heating electric boiler also includes an air distribution structure (5), which is set inside the refractory insulating barrel (2). It is a cone-shaped body made of refractory insulating material, with the tip of the cone pointing towards the inside of the refractory insulating barrel (2) and coaxially installed with the refractory insulating barrel (2), and arranged opposite to the air inlet (17) of the circulating air duct (11).

4. A high-voltage direct-heating electric boiler according to claim 1, characterized in that, The inner cavity (6) is connected to the fire-resistant insulating barrel (2) on its vertical side, and its two end faces are connected to the air distribution structure (5) and the air inlet (17) respectively. A guide plate (16) is provided inside the air inlet (17).

5. A high-voltage direct-heating electric boiler according to claim 1, characterized in that, The high-voltage direct-heating electric boiler also includes an insulating base (9), which is located at the bottom of the fire-resistant insulating barrel (2) and is made of high-temperature electrical ceramics and magnesium-based refractory material with a content of 92%. A heat insulation structure (8) is also provided between the insulating base (9) and the fire-resistant insulating barrel (2).

6. A high-voltage direct-heating electric boiler according to claim 1, characterized in that, The heat exchange component (12) is a metal tubular structure with heat exchange fins (12-2) on a heat exchange tube (12-1), and the heating medium (13) flows inside the heat exchange tube (12-1).

7. A high-voltage direct-heating electric boiler according to claim 1, characterized in that, The high-voltage direct-heating electric boiler also includes a circulating fan cooling system (10-1), which is installed on the circulating fan (10) and connected to the drive shaft.

8. A high-voltage direct-heating electric boiler according to claim 1, characterized in that, The electric heating wire (3) forms a connection structure inside the fire-resistant insulating barrel (2), with heating wire connection wire A end (3-1) and heating wire connection wire B end (3-2) connected at both ends respectively.

9. A high-voltage direct-heating electric boiler according to claim 6, characterized in that, The heating medium (13) is any one of heat transfer oil, water, molten salt, or steam.

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