Variable cross-section tube-in-tube heating element

Abstract

This utility model relates to the field of electric heaters, specifically a variable cross-section tube-in-tube heating element. The heating element has a wiring portion and a sleeve fitted over it, with a flow gap between the sleeve and the heating element. The sleeve has an inlet pipe and an outlet pipe communicating with the flow gap. A limiting portion protrudes towards the heating element. This protrusion reduces the local size of the flow gap, ensuring that when the amount of liquid flowing in from the inlet pipe is small, the liquid at the limiting portion remains in contact with the heating element, preventing a rapid temperature rise and thus mitigating dry burning to some extent.

Description

Technical Field

[0001] This utility model relates to the field of electric heaters, and in particular to a variable cross-section tube-in-tube heating element. Background Technology

[0002] To prevent dry burning, existing heaters typically employ electronic control, cutting off power when localized high temperatures occur to prevent dry burning. For example, Chinese patent CN201733451U discloses a thick-film heating assembly with dry-burn protection, including a thick-film heater for electric heating, an electrical connection bracket mounted on the thick-film heater for connecting it to external components, and a dry-burn protector mounted on the thick-film heater. The electrical connection bracket and the dry-burn protector form an integral component, and the dry-burn protector includes at least one electronic dry-burn protection connected to the control circuit and one mechanical dry-burn protection. Because the electrical connection bracket and the dry-burn protector are an integral component, the thick-film heater has a more compact structure and more stable performance. The two dry-burn protections complement each other, providing double protection.

[0003] The problem with existing technology is that, in order to prevent localized high temperatures from occurring during dry burning, repeated power outages due to dry burning will reduce the lifespan of the heater. Utility Model Content

[0004] To solve the above-mentioned technical problems, the purpose of this utility model is to provide a variable cross-section tube-in-tube heating element, which has the advantage of preventing dry burning when the water flow is small.

[0005] The technical solution adopted by this utility model to solve the problem is: a variable cross-section tube-in-tube heating element, comprising:

[0006] The heating body has a wiring part and a sleeve. A flow gap is provided between the sleeve and the heating body. The sleeve has an inlet pipe and an outlet pipe that communicate with the flow gap. The sleeve has a limiting part that protrudes towards the heating body.

[0007] As a further improvement to the above technical solution, the heating body is cylindrical.

[0008] As a further improvement to the above technical solution, the sleeve is cylindrical and the limiting part is annular.

[0009] As a further improvement to the above technical solution, the number of the limiting parts is multiple, and the limiting parts are arranged along the length direction of the sleeve.

[0010] As a further improvement to the above technical solution, the distance from the inner wall of the limiting part to the outer wall of the heating body is a, and the distance from the inner end of the outlet pipe to the outer wall of the heating body is b, where b>2a.

[0011] The beneficial effects of this utility model are: by setting a limiting part, the limiting part protrudes towards the heating body, reducing the local size of the flow gap. When the amount of liquid flowing in from the inlet pipe is small, the liquid at the limiting part can maintain contact with the heating body, avoiding a rapid rise in the temperature of the heating body and preventing dry burning to a certain extent. Attached Figure Description

[0012] The present invention will be further explained below with reference to the accompanying drawings and specific embodiments.

[0013] Figure 1 This is a schematic diagram of the preferred embodiment of the present invention;

[0014] Figure 2 This is a cross-sectional view of a preferred embodiment of the present invention.

[0015] In the diagram: 1-Heating body, 11-Wiring part, 2-Sleeve, 21-Limiting part, 22-Flow gap, 23-Inlet pipe, 24-Outlet pipe. Detailed Implementation

[0016] This section will describe in detail the specific embodiments of the present utility model. The preferred embodiments of the present utility model are shown in the accompanying drawings. The purpose of the drawings is to supplement the textual description with graphics, so that people can intuitively and vividly understand each technical feature and the overall technical solution of the present utility model, but they should not be construed as limiting the scope of protection of the present utility model.

[0017] In the description of this utility model, it should be understood that the directional descriptions, such as up, down, front, back, left, right, etc., indicate the directional or positional relationship based on the directional or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model.

[0018] In the description of this utility model, "several" means one or more, "multiple" means two or more, "greater than," "less than," and "exceeding" are understood to exclude the stated number, while "above," "below," and "within" are understood to include the stated number. If "first" or "second" is used in the description, it is only for the purpose of distinguishing technical features and should not be construed as indicating or implying relative importance, or implicitly indicating the number of indicated technical features, or implicitly indicating the order of the indicated technical features.

[0019] In the description of this utility model, unless otherwise explicitly defined, terms such as "setting," "installation," and "connection" should be interpreted broadly, and those skilled in the art can reasonably determine the specific meaning of the above terms in this utility model in conjunction with the specific content of the technical solution.

[0020] Reference Figures 1 to 2 A variable cross-section tube-in-tube heating element includes: a heating body 1, a wiring portion 11 on the heating body 1, a sleeve 2 sleeved on the heating body 1, a flow gap 22 between the sleeve 2 and the heating body 1, an inlet pipe 23 and an outlet pipe 24 communicating with the flow gap 22 on the sleeve 2; and a limiting portion 21 on the sleeve 2, the limiting portion 21 protruding towards the heating body 1.

[0021] By setting a limiting part 21, which protrudes towards the heating body 1, the local size of the flow gap 22 is reduced. When the amount of liquid flowing in from the inlet pipe 23 is small, the liquid at the limiting part 21 can maintain contact with the heating body 1, thus preventing the temperature of the heating body 1 from rising rapidly and preventing dry burning to a certain extent.

[0022] In a preferred embodiment, the heating body 1 is cylindrical. The cylindrical heating body provides more uniform heating throughout.

[0023] In a preferred embodiment, the sleeve 2 is cylindrical, and the limiting portion 21 is annular. The limiting portion 21 partially and fully encloses the heating element, thereby effectively and significantly reducing the surface temperature of the heating element.

[0024] In a preferred embodiment, there are multiple limiting parts 21, which are arranged along the length direction of the sleeve 2.

[0025] In a preferred embodiment, the distance from the inner wall of the limiting part 21 to the outer wall of the heating body 1 is a, and the distance from the inner end of the outlet pipe 24 to the outer wall of the heating body 1 is b, where b>2a.

[0026] The above are merely preferred embodiments of this utility model and do not limit the patent scope of this utility model. Any equivalent structural transformations made based on the inventive concept of this utility model and the contents of this utility model specification and drawings, or direct or indirect applications in other related technical fields, are included within the patent protection scope of this utility model.

Claims

1. A variable cross-section tube-in-tube heating element, characterized in that, include: A heating body (1) is provided with a wiring part (11), a sleeve (2) is provided on the heating body (1), a flow gap (22) is provided between the sleeve (2) and the heating body (1), and an inlet pipe (23) and an outlet pipe (24) communicating with the flow gap (22) are provided on the sleeve (2). The sleeve (2) is provided with a limiting part (21), which protrudes in the direction close to the heating body (1).

2. The variable cross-section tube-in-tube heating element as described in claim 1, characterized in that: The heating body (1) is cylindrical.

3. The variable cross-section tube-in-tube heating element as described in claim 2, characterized in that: The sleeve (2) is cylindrical, and the limiting part (21) is annular.

4. The variable cross-section tube-in-tube heating element as described in claim 1, characterized in that: The number of limiting parts (21) is multiple, and the limiting parts (21) are arranged along the length direction of the sleeve (2).

5. A variable cross-section tube-in-tube heating element as described in claim 1, characterized in that: The distance from the inner wall of the limiting part (21) to the outer wall of the heating body (1) is a, and the distance from the inner end of the outlet pipe (24) to the outer wall of the heating body (1) is b, where b>2a.

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