High-power sleeve type fused salt electric heating tube

Abstract

The invention discloses a high-power sleeve-type fused salt electric heating tube which comprises a sleeve and a seal head, the seal head is connected to the tail end of the sleeve, an outer shell, an inner shell and partition plates are arranged on the sleeve and the seal head respectively, a channel for fused salt to flow is arranged between the outer shell and the inner shell, and the fused salt channel is divided into a plurality of flowing channels by the partition plates. A flow hole is formed in the partition plate at the end socket, the flow channels are communicated through the flow hole at the end socket, a heat conduction insulator is arranged in the inner shell, a heating resistance wire is arranged in the heat conduction insulator, and a gap between the heat conduction insulator and the heating resistance wire is compacted through a heat conduction insulation filling material. The partition plate, the inner shell and the outer shell form the channels for molten salt to flow, meanwhile, the multiple flowing channels are communicated with one another, the heat exchange time of the molten salt and the electric heating pipe is effectively prolonged, meanwhile, the narrow flowing channels can guarantee that the molten salt keeps a very high flowing speed, local flowing dead zones are prevented from being formed, and the service life of the electric heating pipe is prolonged. And the phenomenon of fused salt decomposition failure caused by local overheating is effectively restrained.

Description

Technical Field

[0001] The present invention relates to the field of solar thermal power generation and abandoned wind and solar power energy storage technology, and in particular to a high-power sleeve-type molten salt electric heating tube. Background Art

[0002] In recent years, clean energy such as solar energy and wind energy has been widely developed. However, compared with traditional energy, these energy sources are intermittent, volatile, and greatly affected by natural conditions. Direct large-scale application increases the difficulty of power grid construction and reduces the stability and safety of the power grid. In order to solve the problem of poor stability of this type of energy, large-scale energy storage technology has emerged. Molten salt energy storage uses the temperature difference of molten salt during the heat absorption and heat release process to achieve thermal energy storage. It has very little hysteresis and can convert wind power and solar thermal power generation into thermal energy in real time through molten salt electric heaters. It is especially suitable for wind and solar power abandonment.

[0003] At present, molten salt electric heaters mainly include resistive, inductive and electrode types, among which resistive heating has the highest efficiency and is widely used. As the scale of energy storage continues to increase, traditional low-voltage resistive heaters are limited by heating power and are difficult to apply to large-scale molten salt energy storage. High-voltage resistive molten salt electric heaters are directly connected to high-voltage circuits, which saves the cost of power distribution equipment, while increasing heating power and greatly reducing site requirements. However, the surface heating power of high-voltage resistive heaters is very high. If the molten salt flow rate is low or even a flow dead zone occurs, the local temperature of the electric heater will rise rapidly, causing the molten salt to overheat and decompose, seriously affecting the safety of the system. For this reason, a high-power sleeve-type molten salt electric heating tube is needed to improve the above problems. Summary of the invention

[0004] In order to solve the above technical problems, the present invention designs a high-power sleeve-type molten salt electric heating tube to solve the problems of uneven heating and easy local overheating of high-voltage resistive heaters in the prior art.

[0005] The present invention adopts the following technical solution: A high-power sleeve-type molten salt electric heating tube comprises a sleeve and a head, wherein the head is connected to the end of the sleeve, wherein an outer shell, an inner shell and a partition are respectively arranged on the sleeve and the head, wherein a channel for the flow of molten salt is arranged between the outer shell and the inner shell, wherein the molten salt channel is divided into a plurality of flow channels by a plurality of partitions, wherein a flow hole is arranged on the partition at the head, wherein the plurality of flow channels are connected via the flow hole at the head, wherein a heat-conducting insulator is arranged inside the inner shell, wherein a heating resistance wire is arranged inside the heat-conducting insulator, and wherein a gap between the heat-conducting insulator and the heating resistance wire is compacted with a heat-conducting insulating filling material.

[0006] Preferably, the sleeve is composed of multiple sections, which are connected to each other.

[0007] Preferably, the connecting ends of the sleeve and the head are respectively provided with flange structures, the flange structure is provided with an annular groove for placing a sealing gasket, the annular groove is installed with a sealing gasket, the sleeve and the head or the sleeve and the sleeve are connected by the flange structure and bolts, and the sleeve and the head or the sleeve and the sleeve are sealed by the sealing gasket.

[0008] Preferably, the base of the sealing gasket is made of metal material, and high-temperature resistant soft metal material is welded on both side surfaces of the sealing gasket base.

[0009] Preferably, one or more heating wire channels are arranged in the thermally conductive insulator.

[0010] Preferably, both ends of the thermally conductive insulator are respectively provided with positioning blocks and positioning grooves for circumferential positioning, preventing rotation and cooperating with each other for assembly.

[0011] Preferably, the thermally conductive insulating filling material is one or more of magnesium oxide, aluminum oxide, and boron nitride powder.

[0012] Preferably, the sealing head is provided with a flow hole for the molten salt to flow into or out of the casing.

[0013] Preferably, the partitions are distributed in parallel in the axial direction and evenly arranged in the circumferential direction. The partitions are composed of two metal plates and a heat-insulating material plate. The heat-insulating material plate is located between the two metal plates.

[0014] Preferably, the thermally conductive insulator is made of a thermally conductive insulating material with high thermal conductivity, and the thermally conductive insulating material is selected from one or more of alumina, magnesium silicate, and boron nitride ceramics.

[0015] The beneficial effects of the present invention are as follows: (1) The outer surface of the electric heating tube of the present invention is welded with a plurality of evenly distributed partitions, and a channel for the flow of molten salt is formed between the partition, the inner shell and the outer shell. At the same time, the plurality of flow channels are interconnected, which effectively increases the heat exchange time between the molten salt and the electric heating tube. At the same time, the narrow flow channel can ensure that the molten salt maintains a very high flow rate, avoids the formation of local flow dead zones, and effectively curbs the phenomenon of molten salt decomposition failure caused by local overheating; (2) The surface heating power of the electric heating tube of the present invention can be significantly improved, thereby reducing the volume of the electric heating equipment, making the equipment size design more flexible and meeting the use requirements of different occasions; (3) The electric heating tube sleeve of the present invention is connected by a flange, and can be assembled with a thermal insulator and a resistance wire into electric heating tubes of various lengths, which reduces the difficulty of processing and manufacturing, and makes later maintenance more convenient. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a structural schematic diagram of the sleeve in the present invention; Figure 2 It is a structural schematic diagram of a partition in the present invention; Figure 3 It is a structural schematic diagram of the head of the present invention; Figure 4 yes Figure 3 Rear view of Figure 5 It is a structural schematic diagram of a heat-conducting insulator in the inner shell of the sleeve in the present invention; Figure 6 It is a structural schematic diagram of a sealing gasket in the present invention; In the figure: 1. sleeve; 11. flange structure; 12. ring groove; 2. outer shell; 3. inner shell; 4. partition; 41. metal plate; 42. thermal insulation material plate; 5. head; 51. flow hole; 52. flow hole; 6. thermal insulator; 61. heating wire channel; 62. positioning block; 63. positioning groove; 7. sealing gasket; 71. substrate; 72. soft metal material. DETAILED DESCRIPTION

[0017] The technical solution of the present invention is further described in detail below through specific embodiments and in conjunction with the accompanying drawings: Example: Figure 1-Figure 6 As shown, a high-power sleeve-type molten salt electric heating tube comprises a sleeve 1 and a head 5, wherein an outer shell 2, an inner shell 3 and a partition 4 are respectively arranged on the sleeve 1 and the head 5, a channel for molten salt flow is arranged between the outer shell 2 and the inner shell 3, and the molten salt channel is divided into a plurality of flow channels by the partition 4, a flow hole 52 is opened on the partition 4 at the head 5, and the flow channels are connected through the flow hole 52 of the head 5, a heat-conducting insulator 6 is arranged inside the inner shell 2, a heating resistance wire is arranged inside the heat-conducting insulator 6, and a gap between the heat-conducting insulator 6 and the heating resistance wire is compacted with a heat-conducting insulating filling material.

[0018] The thermally conductive insulating filling material is selected from one or more of magnesium oxide, aluminum oxide, boron nitride powder and the like.

[0019] like Figure 1 , Figure 3 , Figure 4 and Figure 6 As shown, the sleeve 1 and the head 5 are both provided with a flange structure 11 for sleeve connection, and an annular groove 12 for placing a sealing gasket is provided on the flange structure 11. The sleeves and the head are connected through the flange structure 11 and bolts, and the sleeves and the head are sealed through the sealing gasket. The base 71 of the sealing gasket 7 is made of metal material, and high-temperature resistant soft metal material 72 is welded on both sides of the sealing gasket base 71. During installation, the flange annular groove 12 and the sealing gasket 7 are pressed by the pre-tightening force of the bolts. The soft metal material 72 is squeezed and deformed to fill the gap between the sleeve 1 or the head 5 and the sealing gasket 7, thereby ensuring the safety and reliability of the seal.

[0020] like Figure 5 As shown, a heat-conducting insulator 6 is installed in the inner shell of the sleeve, and one or more heating wire channels 61 are arranged in the heat-conducting insulator 6. Positioning blocks 62 and positioning grooves 63 for circumferential positioning and preventing rotation and assembled in cooperation with each other are respectively arranged at both ends of the heat-conducting insulator 6; the sleeve 1, the heat-conducting insulator 6, and the resistance wire can be flexibly arranged in length according to engineering needs; the heat-conducting insulator 6 is made of a heat-conducting insulating material with high thermal conductivity.

[0021] The thermally conductive insulating material is selected from one or more of alumina, magnesium silicate, boron nitride ceramics, etc.

[0022] like Figure 3 and Figure 4 As shown, a flow hole 51 is provided on the sleeve head 5 for the molten salt to flow into or out of the sleeve. The low-temperature molten salt flows into the sleeve from the flow hole 51 and flows axially along the heating tube. The partition 4 is provided with a flow hole 52 according to the flow demand. The molten salt automatically flows into the next flow to continue heating until it flows out of the heat exchange tube from the flow hole 51.

[0023] like Figure 1 and Figure 2 As shown, the partition 4 is distributed axially parallel and evenly arranged along the circumferential direction. The partition 4 is composed of two metal plates 41 and a thermal insulation material plate 42. The thermal insulation material plate 42 is located between the two metal plates 41, which effectively isolates the influence of wall heat transfer on the temperature distribution of the molten salt. The connection method between the metal plate 41 and the outer shell 2 and the metal plate 41 and the inner shell 3 is welding.

[0024] The above-described embodiment is only a preferred solution of the present invention and does not limit the present invention in any form. There are other variations and modifications without exceeding the technical solution described in the claims.

Claims

1. A high-power sleeve-type molten salt electric heating tube, comprising a sleeve and a head, wherein the head is connected to the end of the sleeve, and is characterized in that: The sleeve and the head are respectively provided with an outer shell, an inner shell and a partition, a channel for molten salt flow is provided between the outer shell and the inner shell, the molten salt channel is divided into multiple flow channels by multiple partitions, a flow hole is opened on the partition at the head, and the multiple flow channels are connected through the flow hole at the head, a thermal conductive insulator is provided inside the inner shell, a heating resistance wire is provided inside the thermal conductive insulator, and the gap between the thermal conductive insulator and the heating resistance wire is compacted with a thermal conductive insulating filling material.

2. A high-power sleeve-type molten salt electric heating tube according to claim 1, characterized in that: The sleeve is divided into multiple sections, and the multiple sections are connected to each other.

3. A high-power sleeve-type molten salt electric heating tube according to claim 2, characterized in that: The connecting ends of the sleeve and the head are respectively provided with flange structures, the flange structure is provided with an annular groove for placing a sealing gasket, and the sealing gasket is installed in the annular groove. The sleeve and the head or the sleeve and the sleeve are connected by the flange structure and bolts, and the sleeve and the head or the sleeve and the sleeve are sealed by the sealing gasket.

4. The high-power sleeve-type molten salt electric heating tube according to claim 1 is characterized in that: The base of the sealing gasket is made of metal material, and high-temperature resistant soft metal material is welded on both sides of the sealing gasket base.

5. The high-power sleeve-type molten salt electric heating tube according to claim 1 is characterized in that: One or more heating wire channels are arranged in the heat-conducting insulator.

6. The high-power sleeve-type molten salt electric heating tube according to claim 1 is characterized in that: The two ends of the heat-conducting insulator are respectively provided with positioning blocks and positioning grooves for circumferential positioning, preventing rotation and cooperating with each other for assembly.

7. The high-power sleeve-type molten salt electric heating tube according to claim 1 is characterized in that: The thermally conductive insulating filling material is selected from one or more of magnesium oxide, aluminum oxide, and boron nitride powder.

8. The high-power sleeve-type molten salt electric heating tube according to claim 1 is characterized in that: The sealing head is provided with flow holes for the molten salt to flow into or out of the casing.

9. The high-power sleeve-type molten salt electric heating tube according to claim 1 is characterized in that: The partitions are distributed in parallel in the axial direction and are evenly arranged in the circumferential direction. The partitions are composed of two metal plates and a heat-insulating material plate, and the heat-insulating material plate is located between the two metal plates.

10. The high-power sleeve-type molten salt electric heating tube according to claim 1 is characterized in that: The thermally conductive insulator is made of a thermally conductive insulating material with high thermal conductivity, and the thermally conductive insulating material is selected from one or more of aluminum oxide, magnesium silicate, and boron nitride ceramics.

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