A double-barrel electric heater
By designing a double-cylinder electric heater, the cavity is divided into a first cavity and a second cavity, and the flow rate and heat transfer effect of the fluid medium are increased, the problem of difficulty in arranging elongated heaters in a limited space is solved, and efficient heating and heat transfer effect is achieved.
Patent Information
- Application Number
- CN202411966776.9
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-12-30
- Publication Date
- 2025-04-04
AI Technical Summary
In the case where the allowed arrangement space is limited, it is difficult to effectively arrange the elongated heater to improve the flow rate of molten salt and heat exchange effect.
A double-cylinder electric heater is designed to reduce the radial cross-sectional area of the cavity into a first cavity and a second cavity, increase the flow rate of the fluid medium, thereby improving the heat transfer power per unit area, and optimizing heat transfer and thermal conductivity through the design of the support plate.
It is achieved to increase the total heating power and heat transfer effect without increasing the layout space, avoid overtemperature of the external heating pipe, and reduce the impact area of the fluid medium on the support plate, and prevent vibration and friction.
Smart Images
Figure CN119756055A_ABST
Abstract
Description
Technical Field
[0001] The invention relates to molten salt energy storage, and in particular to a double-barrel electric heater. Background Art
[0002] Molten salt is a molten body formed by melting salts. It has the advantages of good heat transfer performance, high heat storage density and high heat storage temperature. It is used as a highly stable heat storage and exchange medium and is widely used in the fields of solar thermal power generation and heat storage.
[0003] Under equal flow rates, the smaller the diameter of the cylinder of the relevant heater, the faster the flow rate of the molten salt, the better the heat exchange effect, and there will be no overheating even if the total heating power is increased. In other words, a slender heater needs to be designed, but when the allowed layout space is small, it is difficult to effectively arrange a slender heater. Summary of the invention
[0004] Purpose of the invention: The purpose of the present invention is to provide a double-cylinder electric heater, which not only increases the total heating power without occupying additional layout space, but also facilitates the support plate to produce less obstruction to the flow of molten salt and reduces the impact area of molten salt on the support plate. Furthermore, its support plate has good heat transfer and thermal conductivity.
[0005] Technical solution:
[0006] A double-barrel electric heater, comprising:
[0007] An inner cylinder, wherein the inner cylinder is provided with an inlet portion and a first cavity which are communicated with each other;
[0008] An internal heating tube, at least part of which is located in the first cavity;
[0009] An outer cylinder wrapped around the inner cylinder, a second cavity communicating with the first cavity is provided between the outer cylinder and the inner cylinder, and the outer cylinder is provided with an outlet communicating with the second cavity;
[0010] A connecting portion provided in the inner cylinder, one end of the connecting portion is connected to the first cavity, and the other end of the connecting portion is connected to the second cavity;
[0011] an external heating tube, at least a portion of which is located in the second cavity;
[0012] A plurality of support plates are arranged at intervals along the circumference of the outer cylinder, one end of the support plate is connected to the outer wall of the inner cylinder, the other end of the support plate is connected to the inner wall of the outer cylinder, the external heating tube passes through the support plate, and the support plate is located in the second cavity.
[0013] Optionally, the support plate includes:
[0014] A supporting tube body, wherein the external heating tube is sleeved in the supporting tube body;
[0015] A first plate and a second plate are respectively connected to both sides of the support tube, wherein one end of the first plate away from the support tube is connected to the outer wall of the inner tube, and one end of the second plate away from the support tube is connected to the inner wall of the outer tube.
[0016] Optionally, the support plate further includes a plurality of fins arranged at intervals along the circumferential direction on the outer wall of the support tube body.
[0017] Optionally, also include:
[0018] a guide plate connected to the inner wall of the outer cylinder;
[0019] A flow channel is formed between the guide plate and an outer wall of one end of the inner cylinder having a connecting portion, one end of the flow channel is connected to the connecting portion, and the other end of the flow channel is connected to the second cavity.
[0020] Optionally, the shape of the guide plate and / or the shape of one end of the inner cylinder having the connecting portion are both arc-shaped.
[0021] Optionally, it also includes a plurality of baffles spaced axially within the inner cylinder, wherein a zigzag flow channel is formed between adjacent baffles, the zigzag flow channel is connected to the first cavity, the baffles are located within the first cavity, and the internal heating tube passes through the baffles.
[0022] Optionally, the inner cylinder has an inner flange, and the inner heating pipe passes through the inner flange.
[0023] Optionally, the outer cylinder has an outer flange, and the external heating pipe passes through the outer flange.
[0024] Optionally, the wall of the inner cylinder is in the shape of a wavy curved surface.
[0025] Optionally, the radial cross-sectional area S1 of the inner cylinder is greater than the radial cross-sectional area S2 of the outer cylinder.
[0026] Beneficial effects:
[0027] (1) The present application divides an integral cavity into a first cavity and a second cavity, which is convenient for reducing the radial cross-sectional area of the cavity, thereby facilitating increasing the flow rate of the fluid medium to ensure the heat transfer power per unit area, and does not increase the axial length of the double-barrel electric heater of the present embodiment, thereby facilitating the arrangement of the double-barrel electric heater of the present application, that is, the total heating power is increased without occupying additional arrangement space;
[0028] (2) The flow velocity of the fluid medium in the high temperature section of the present application is relatively fast, which is convenient for making the heat transfer coefficient high and preventing the external heating tube from overheating. The inner cylinder body with a wavy curved surface of the cylinder wall is convenient for increasing the flow turbulence of the fluid medium in the high temperature section and the low temperature section at the same time, thereby enhancing the heat transfer effect;
[0029] (3) The support plate and the inner cylinder and the outer cylinder of the present application tend to be in surface contact rather than point contact, which makes it easier for the support plate to be used for heat transfer, and facilitates part of the heat generated by the external heating tube to be transferred to the fluid medium in the second cavity through the support plate. It has a large heat transfer area, and will not overheat even if the heating power of the external heating tube is increased; the support plate is also used for heat conduction, which facilitates another part of the heat generated by the external heating tube to be transferred to the inner cylinder through the support plate, so that the inner cylinder also heats the fluid medium in the first cavity, that is, the inner cylinder and the inner heating tube jointly heat the fluid medium in the first cavity, which, on the one hand, facilitates increasing the overall heating effect of the inner cylinder and the inner heating tube, and on the other hand, facilitates preventing the external heating tube from overheating;
[0030] (4) The support plate of the present application follows the flow direction of the fluid medium, does not hinder the downstream heat transfer of the fluid medium, has no heating dead zone, and will not be vibrated by the front impact of the fluid medium;
[0031] (5) The connection method between the support plate and the external heating tube is preferably plug-in. When the external heating tube expands, it will not contact other parts and cause wear, so that the contact friction between the external heating tube and other parts will not be caused by the impact of the rapid flow of the fluid medium. It is convenient for the support plate to provide stable support for the external heating tube, thereby improving the structural strength of the external heating tube. BRIEF DESCRIPTION OF THE DRAWINGS
[0032] Figure 1 This is one of the structural schematic diagrams of a double-barrel electric heater of Example 1 of the present invention;
[0033] Figure 2 yes Figure 1 Cross-sectional view of AA in the middle;
[0034] Figure 3 is a schematic structural diagram of a support plate according to Embodiment 1 of the present invention;
[0035] Figure 4 is a schematic structural diagram of a baffle according to Embodiment 1 of the present invention;
[0036] Figure 5 This is a second structural schematic diagram of a double-barrel electric heater according to embodiment 1 of the present invention;
[0037] In the figure: 1. inner cylinder; 111. first cavity; 112. inlet; 113. connecting part; 12. inner flange; 121. second through hole; 13. baffle; 131. first through hole; 21. inner heating tube; 22. inner distribution box; 3. outer cylinder; 311. second cavity; 312. outlet; 32. outer flange; 321. third through hole; 41. outer heating tube; 42. outer distribution box; 5. support plate; 51. first plate; 52. second plate; 53. support tube; 54. fin; 6. guide plate; 61. flow channel. DETAILED DESCRIPTION
[0038] In order to make the technical solution of the present invention clearer, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.
[0039] Example 1
[0040] like Figure 1-Figure 2 The present embodiment provides a double-cylinder electric heater, comprising: an inner cylinder 1, the inner cylinder 1 being provided with an inlet 112 and a first cavity 111 which are connected to each other; an inner heating tube 21, at least part of the inner heating tube 21 being located in the first cavity 111; an outer cylinder 3 sheathed outside the inner cylinder 1, a second cavity 311 connected to the first cavity 111 being provided between the outer cylinder 3 and the inner cylinder 1, the outer cylinder 3 being provided with an outlet 312 connected to the second cavity 311; a connecting portion 312 provided at the inner cylinder 1 The connecting portion 113 has one end connected to the first cavity 111, and the other end connected to the second cavity 311; an external heating tube 41, at least part of the external heating tube 41 is located in the second cavity 311; a plurality of support plates 5 are arranged at intervals along the circumference of the outer cylinder 3, one end of the support plate 5 is connected to the outer wall of the inner cylinder 1, and the other end of the support plate 5 is connected to the inner wall of the outer cylinder 3, the external heating tube 41 passes through the support plate 5, and the support plate 5 is located in the second cavity 311.
[0041] Specifically, during operation, first, the fluid medium such as molten salt flows into the first cavity 111 from the inlet 112, and the internal heating tube 21 heats the fluid medium for the first time. Then, the fluid medium flows from the first cavity 111 into the second cavity 311, and the external heating tube 41 heats the fluid medium for the second time. Finally, the fluid medium flows out of the second cavity 311 from the outlet 312, which is equivalent to dividing an integral cavity into the first cavity 111 and the second cavity 311, so as to reduce the radial cross-sectional area of the cavity, thereby facilitating the increase of the flow rate of the fluid medium to ensure the heat transfer power per unit area, and does not increase the axial length of the double-cylinder electric heater of this embodiment, thereby facilitating the arrangement of the double-cylinder electric heater of this embodiment, that is, the total heating power is increased without occupying additional arrangement space.
[0042] The inner cylinder 1 is used to form an inlet 112, a first cavity 111, etc. The shape of the cylinder wall of the inner cylinder 1 can be a smooth curved surface, a wavy curved surface, etc.; the inlet 112 is convenient for the fluid medium to enter the first cavity 111, and the inlet 112 can be an opening opened on the inner cylinder 1, or a pipe connected to the inner cylinder 1; the first cavity 111 is used for the fluid medium to flow through; the inner heating tube 21 is used to heat the fluid medium in the first cavity 111, and the number of the inner heating tubes 21 is preferably multiple, which can be twelve, fourteen, etc. In order to facilitate power distribution, the inner heating tube 21 can be electrically connected to the inner distribution box 22; the outer cylinder 3 is used to form a second cavity 311, an outlet The second cavity 311 is used for the fluid medium to flow through; the outlet portion 312 facilitates the fluid medium to flow out of the second cavity 311, and the outlet portion 312 can be an opening opened on the outer cylinder 3, or a pipe connected to the outer cylinder 3; the connecting portion 113 is used to connect the first cavity 111 and the flow channel 61, and the connecting portion 113 can be an opening opened on the inner cylinder 1, or a pipe connected to the inner cylinder 1; the external heating tube 41 is used to heat the fluid medium in the second cavity 311, and the number of the external heating tubes 41 is preferably multiple, which can be twelve, fourteen, etc. In order to facilitate power distribution, the external heating tube 41 can be electrically connected to the external distribution box 42.
[0043] The support plate 5 is used to connect the inner cylinder 1 and the outer cylinder 3 to prevent the inner cylinder 1 and the outer cylinder 3 from moving relative to each other. Since a plurality of support plates 5 are arranged at intervals along the circumference of the outer cylinder 3, and since the fluid medium flows in the first cavity 111 and the second cavity 311, that is, the fluid medium moves along the axial direction of the inner cylinder 1 and the outer cylinder 3, it is convenient to make the support plate 5 have a small blocking area for the fluid medium, which can be almost ignored, so that the support plate 5 can produce a small blocking to the flow of the fluid medium, thereby preventing the flow velocity of the fluid medium from slowing down, thereby ensuring a good heat exchange effect and preventing the outer The heating tube 41 is partially overheated, and the impact area of the fluid medium on the support plate 5 is small and almost negligible, so as to reduce the impact area of the fluid medium on the support plate 5, thereby preventing the fluid medium from continuously impacting the support plate 5 over a large area to cause vibration, and preventing the connection between the support plate 5 and the external heating tube 41 from continuous friction, preventing aggravation of physical wear and chemical corrosion, and finally preventing tube burst; the support plate 5 is also used for heat transfer, so that part of the heat generated by the external heating tube 41 is transferred to the fluid medium in the second cavity 311 through the support plate 5, and has a large heat transfer surface The support plate 5 is also used for heat conduction, so that another part of the heat generated by the external heating tube 41 is transmitted to the inner cylinder 1 through the support plate 5, so that the inner cylinder 1 also heats the fluid medium in the first cavity 111, that is, the inner cylinder 1 and the internal heating tube 21 jointly heat the fluid medium in the first cavity 111, which is convenient for increasing the overall heating effect of the inner cylinder 1 and the internal heating tube 21 on the one hand, and preventing the external heating tube 41 from overheating on the other hand; the number of support plates 5 can be flexibly set according to needs, The number of support plates 5 can be sixteen, eighteen, etc. The spacing between adjacent support plates 5 is preferably equal, which is convenient for ensuring that the force uniformity of the inner cylinder 1 and the outer cylinder 3 is good, and for ensuring that the heat transfer and heat conduction of the support plate 5 are uniform; the connection method between the support plate 5 and the external heating tube 41 is preferably plug-in, and when the external heating tube 41 expands, it will not contact other parts and cause wear, so that the external heating tube 41 and other parts will not be contacted and rubbed due to the impact of the rapid flow of the fluid medium, which is convenient for the support plate 5 to provide stable support for the external heating tube 41, thereby improving the structural strength of the external heating tube 41.
[0044] Further, such as Figure 2-Figure 3 The support plate 5 includes: a support tube body 53, in which the external heating tube 41 is sleeved; a first plate body 51 and a second plate body 52 connected to both sides of the support tube body 53, respectively; an end of the first plate body 51 away from the support tube body 53 is connected to the outer wall of the inner cylinder 1, and an end of the second plate body 52 away from the support tube body 53 is connected to the inner wall of the outer cylinder 3. Specifically, the support tube body 53 is used to wrap the external heating tube 41; the first plate body 51 is used to connect the support tube body 53 to the outer wall of the inner cylinder 1, and the second plate body 52 is used to connect the support tube body 53 to the inner wall of the outer cylinder 3.
[0045] Further, such as Figure 3 The support plate 5 further includes a plurality of fins 54 arranged at intervals along the circumferential direction on the outer wall of the support tube body 53. Specifically, the plurality of fins 54 are used for heat transfer, and further facilitate a portion of the heat generated by the external heating tube 41 to be transferred to the fluid medium in the second cavity 311 through the plurality of fins 54, with a large heat transfer area, and even if the heating power of the external heating tube 41 is increased, the temperature will not be overheated. The number of the plurality of fins 54 can be flexibly set according to demand, and can be six, eight, etc., and the shape of the radial cross section of the fin 54 along the support tube body 53 can be a straight line, a wavy line, etc.
[0046] Further, such as Figure 1 , and also includes: a guide plate 6 connected to the inner wall of the outer cylinder 3; a flow channel 61 formed between the guide plate 6 and the outer wall of one end of the inner cylinder 1 having a connecting portion 113, one end of the flow channel 61 is connected to the connecting portion 113, and the other end of the flow channel 61 is connected to the second cavity 311.
[0047] Specifically, the flow channel 61 is used to connect the first cavity 111 and the second cavity 311, so that the fluid medium can flow through the first cavity 111, the flow channel 61 and the second cavity 311 in sequence; the guide plate 6 is used to guide the flow, so as to facilitate the fluid medium from the first cavity 111 to flow smoothly into the flow channel 61 and the second cavity 311 in sequence.
[0048] Further, such as Figure 1 , the shape of the guide plate 6 and / or the shape of the end of the inner cylinder 1 having the connecting portion 113 are both arc-shaped. Specifically, only the shape of the guide plate 6 can be set to be an arc, or only the shape of the end of the inner cylinder 1 having the connecting portion 113 can be set to be an arc, or both the shape of the guide plate 6 and the shape of the end of the inner cylinder 1 having the connecting portion 113 can be set to be an arc, and the arc shape is convenient for effectively reducing the baffle resistance, and further facilitates the fluid medium from the first cavity 111 to flow smoothly into the flow channel 61 and the second cavity 311 in sequence.
[0049] Further, such as Figure 1 , Figure 2 and Figure 4 , and also includes a plurality of baffles 13 axially spaced apart in the inner cylinder 1, a zigzag flow channel is formed between adjacent baffles 13, the zigzag flow channel is connected to the first cavity 111, the baffles 13 are located in the first cavity 111, and the internal heating tube 21 passes through the baffles 13.
[0050] Specifically, the zigzag flow channel facilitates the S-shaped reciprocating deflection of the fluid medium in the first cavity 111. The zigzag flow channel can be formed by connecting adjacent baffles 13 to the radial inner walls of the inner cylinder 1 respectively. In order to prevent the baffles 13 and the internal heating tube 21 from interfering with each other, a first through hole 131 can be provided on the baffle 13 to facilitate the internal heating tube 21 to pass through the baffle 13.
[0051] Further, such as Figure 1 The inner cylinder 1 has an inner flange 12, and the inner heating tube 21 passes through the inner flange 12. Specifically, the inner flange 12 is used to seal the inner cylinder 1. The inner heating tube 21 and the inner flange 12 are preferably welded to have good sealing performance. In order to prevent the inner flange 12 and the inner heating tube 21 from interfering with each other, a second through hole 121 can be provided on the inner flange 12 to facilitate the inner heating tube 21 to pass through the inner flange 12.
[0052] Further, such as Figure 1 The outer cylinder 3 has an outer flange 32, and the outer heating tube 41 passes through the outer flange 32. Specifically, the outer flange 32 is used to seal the outer cylinder 3. The outer heating tube 41 and the outer flange 32 are preferably welded to have good sealing performance. In order to prevent the outer flange 32 and the outer heating tube 41 from interfering with each other, a third through hole 321 can be provided on the outer flange 32 to facilitate the outer heating tube 41 to pass through the outer flange 32.
[0053] Further, such as Figure 5 , the shape of the cylinder wall of the inner cylinder 1 is a wavy curved surface. Specifically, the inner cylinder 1 with a wavy curved surface shape is convenient for making the first cavity 111 present a certain wave shape, thereby facilitating the increase of the flow turbulence of the fluid medium in the first cavity 111, and further facilitating the increase of the heat transfer effect of the inner heating tube 21 on the fluid medium in the first cavity 111. The inner cylinder 1 with a wavy curved surface shape is also convenient for making the second cavity 311 present a certain wave shape, thereby facilitating the increase of the flow turbulence of the fluid medium in the second cavity 311, and further facilitating the increase of the heat transfer effect of the outer heating tube 41 on the fluid medium in the second cavity 311.
[0054] Further, such as Figure 2, the radial cross-sectional area S1 of the inner cylinder 1 is greater than the radial cross-sectional area S2 of the outer cylinder 3. Specifically, the radial cross-sectional area S1 is relatively large, and the radial cross-sectional area S2 is relatively small, so that the flow velocity of the fluid medium in the first cavity 111 is relatively slow, and the flow velocity in the second cavity 311 is relatively fast. Since the fluid medium flows through the first cavity 111 and the second cavity 311 in sequence, the first cavity 111 is a low-temperature section, and the second cavity 311 is a high-temperature section, that is, the flow velocity of the fluid medium in the high-temperature section is relatively fast, which makes the heat transfer coefficient high and prevents the external heating tube 41 from overheating. The ratio of the radial cross-sectional area S2 to the radial cross-sectional area S1 is in the range of 0.7-0.8, so that the flow velocity of the fluid medium in the first cavity 111 is in the range of 0.4-0.5 m / s, and the flow velocity in the second cavity 311 is in the range of 0.9-1.0 m / s, so that the fluid medium flows through the first cavity 111 for a longer time, so that the fluid medium is heated as much as possible, but the temperature of the internal heating tube 21 will not be too high due to the slow flow rate.
[0055] The above embodiments only express several implementation methods of the present invention, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the present invention. It should be pointed out that, for a person of ordinary skill in the art, several modifications and improvements can be made without departing from the concept of the present invention, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the present invention patent shall be subject to the attached claims.
Claims
1. A double-barrel electric heater, characterized in that: include: An inner cylinder (1), wherein the inner cylinder (1) is provided with an inlet portion (112) and a first cavity (111) which are communicated with each other; An internal heating tube (21), at least a portion of the internal heating tube (21) is located in the first cavity (111); an outer cylinder (3) encased outside the inner cylinder (1), a second cavity (311) communicating with the first cavity (111) being provided between the outer cylinder (3) and the inner cylinder (1), and an outlet (312) communicating with the second cavity (311); A communication portion (113) is provided on the inner cylinder (1), one end of the communication portion (113) is in communication with the first cavity (111), and the other end of the communication portion (113) is in communication with the second cavity (311); an external heating tube (41), at least a portion of the external heating tube (41) being located in the second cavity (311); A plurality of support plates (5) are arranged at intervals along the circumference of the outer cylinder (3), one end of each support plate (5) is connected to the outer wall of the inner cylinder (1), and the other end of each support plate (5) is connected to the inner wall of the outer cylinder (3), the external heating tube (41) passes through the support plate (5), and the support plate (5) is located in the second cavity (311).
2. A double-barrel electric heater according to claim 1, characterized in that: The support plate (5) comprises: A supporting tube body (53), wherein the external heating tube (41) is sleeved inside the supporting tube body (53); A first plate body (51) and a second plate body (52) are respectively connected to two sides of the support tube body (53), wherein one end of the first plate body (51) away from the support tube body (53) is connected to the outer wall of the inner tube body (1), and one end of the second plate body (52) away from the support tube body (53) is connected to the inner wall of the outer tube body (3).
3. A double-barrel electric heater according to claim 2, characterized in that: The support plate (5) further comprises a plurality of fins (54) arranged at intervals along the circumferential direction on the outer wall of the support tube body (53).
4. A double-barrel electric heater according to any one of claims 1 to 3, characterized in that: Also includes: A guide plate (6) connected to the inner wall of the outer cylinder (3); A flow channel (61) is formed between the guide plate (6) and the outer wall of one end of the inner cylinder (1) having a connecting portion (113); one end of the flow channel (61) is connected to the connecting portion (113), and the other end of the flow channel (61) is connected to the second cavity (311).
5. A double-barrel electric heater according to claim 4, characterized in that: The shape of the guide plate (6) and / or the shape of one end of the inner cylinder (1) having the connecting portion (113) are both arc-shaped.
6. A double-barrel electric heater according to any one of claims 1 to 3, characterized in that: It also includes a plurality of baffles (13) spaced apart along the axial direction and located inside the inner cylinder (1), wherein a zigzag flow channel is formed between adjacent baffles (13), the zigzag flow channel is connected to the first cavity (111), the baffles (13) are located inside the first cavity (111), and the internal heating tube (21) passes through the baffles (13).
7. A double-barrel electric heater according to any one of claims 1 to 3, characterized in that: The inner cylinder (1) has an inner flange (12), and the inner heating pipe (21) passes through the inner flange (12).
8. A double-barrel electric heater according to any one of claims 1 to 3, characterized in that: The outer cylinder (3) has an outer flange (32), and the outer heating pipe (41) passes through the outer flange (32).
9. A double-barrel electric heater according to any one of claims 1 to 3, characterized in that: The wall of the inner cylinder (1) is in the shape of a wavy curved surface.
10. A double-barrel electric heater according to any one of claims 1 to 3, characterized in that: The radial cross-sectional area S1 of the inner cylinder (1) is greater than the radial cross-sectional area S2 of the outer cylinder (3).