A high voltage detachable molten salt electric heating device

Abstract

The application discloses a high-voltage detachable molten salt electric heating device, which comprises a shell, a molten salt inlet and a molten salt outlet arranged at two ends of the shell, the shell comprises an upper shell and a lower shell which are detachably arranged, a plurality of electric heating elements are arranged along an axis in the shell, the electric heating element comprises insulating ceramic and an electric heating wire, the electric heating wire is coated with the insulating ceramic, the electric heating wire is provided with leading rods mounted at two ends thereof, the leading rods extend out of the upper shell from the upper end of the insulating ceramic, the electric heating element is connected with a high-voltage electric connection line through the leading rods, and the insulating ceramic is provided with flow holes for molten salt flow in a thickness direction. The application adopts a modular detachable design, when a fault occurs, only the corresponding electric heating device needs to be taken out, so that the shutdown time is obviously shortened, and the economic loss of the molten salt system is reduced; the electric heating wire is spirally arranged in the electric heating element, the effective length of the electric heating wire is increased, and the high-voltage bearing capacity of the electric heating element is improved.

Description

Technical Field

[0001] This invention relates to an electric heater, and more particularly to a high-voltage detachable molten salt electric heating device. Background Technology

[0002] In recent years, the installed capacity of renewable energy power generation, represented by wind and solar power, has increased rapidly, and the supporting energy storage devices have also developed rapidly. Molten salt electric heaters are an important component of molten salt energy storage systems, capable of absorbing large-scale wind and solar power generation, thus playing a role in stabilizing power output. Currently, most common high-voltage molten salt electric heaters use a series connection of heating wires. Damage to these wires will cause the entire heating system to fail, and replacing the heating elements is a complex process, often requiring the complete disassembly of the heater, resulting in prolonged downtime of the molten salt system and severely impacting the profitability of molten salt energy storage projects. Therefore, a high-voltage, detachable molten salt electric heating device is needed to address these issues. Summary of the Invention

[0003] To solve the above-mentioned technical problems, the present invention designs a high-voltage detachable molten salt electric heating device.

[0004] The present invention adopts the following technical solution: A high-voltage detachable molten salt electric heating device includes a housing with a molten salt inlet and a molten salt outlet at both ends. The housing includes a detachable upper housing and a lower housing. Multiple electric heating elements are arranged along the axis inside the housing. Each electric heating element includes an insulating ceramic and an electric heating wire. The electric heating wire is covered with insulating ceramic. Lead rods are installed at both ends of the electric heating wire, extending from the upper end of the insulating ceramic into the upper housing. The electric heating elements are connected to a high-voltage connecting line through the lead rods. Flow holes for molten salt flow are provided on the insulating ceramic along its thickness direction.

[0005] Preferably, the upper housing is provided with a conical hole for positioning the power supply heating element, and the insulating ceramic of the electric heating element is provided with a corresponding conical boss. The conical boss and the conical hole are positioned together, and an outlet hole is provided on the conical boss for the outlet rod to be led out of the conical hole.

[0006] Preferably, positioning plates are provided on both sides of the lower housing corresponding to the electric heating element.

[0007] Preferably, the upper and lower housings are fastened together by bolts.

[0008] Preferably, a groove is provided between the upper and lower housings, and a metal sealing strip is placed in the groove.

[0009] Preferably, the electric heating wire is arranged in a double or multi-turn spiral shape.

[0010] Preferably, the insulating ceramic is a low-temperature sintering type, integrally molded with an electric heating wire, and then formed by sintering.

[0011] Preferably, there is a cavity between adjacent electric heating elements within the housing.

[0012] Preferably, the connecting wire is connected to the electric heating elements of multiple sets of electric heating devices via lead-out rods.

[0013] Preferably, an annular groove is provided in the tapered hole of the upper housing at the connection with the tapered boss, and a metal sealing ring is installed in the groove.

[0014] Preferably, the heating wire is a high-temperature resistant metal heating wire.

[0015] The beneficial effects of the present invention are: (1) The modular and detachable design is adopted, and only the corresponding electric heating device needs to be removed when a fault occurs, which significantly shortens the downtime and reduces the economic loss of the molten salt system; (2) The electric heating wire is spirally arranged inside the electric heating element, which increases the effective length of the electric heating wire and improves the high voltage resistance of the electric heating element; (3) The electric heating element is provided with flow holes, and the molten salt flows in the form of jets, which improves the flow rate of the molten salt and improves the local overheating phenomenon of the molten salt, thereby improving the safety and reliability of the equipment. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the overall structure of the electric heating device of the present invention; Figure 2 This is a schematic diagram of the assembly of the electric heating device of the present invention; Figure 3 This is a partial enlarged view of the electric heating device of the present invention located at the conical hole; Figure 4 This is a schematic diagram of the structure of the electric heating wire in this invention; Figure 5 This is a schematic diagram of the insulating ceramic structure in this invention; Figure 6 This is a schematic diagram of the connection between the connecting wire and the electric heating device in this invention.

[0017] In the diagram: 1. Housing, 11. Upper housing, 111. Conical hole, 112. Metal sealing ring, 113. Groove, 12. Lower housing, 121. Positioning plate, 13. Bolt hole, 14. Bolt, 15. Metal sealing strip, 16. Groove, 2. Electric heating element, 21. Electric heating wire, 22. Flow hole, 23. Insulating ceramic, 24. Conical boss, 3. Lead-out rod, 4. Lead-out hole, 5. Connecting wire. Detailed Implementation

[0018] The technical solution of the present invention will be further described in detail below through specific embodiments and in conjunction with the accompanying drawings: Example: Figures 1-3 As shown, a high-voltage detachable molten salt electric heater device includes: a housing 1 and an electric heating element 2. The housing is detachable and includes an upper housing 11 and a lower housing 12. Bolt holes 13 are provided on both sides of the housing. The upper housing has a conical hole 111 for positioning the electric heating element, and the lower housing has a positioning plate 121 to prevent the electric heating element from rotating. The upper and lower housings are tightly connected by bolts 14. To ensure that the molten salt does not leak, a groove 16 for placing a metal sealing strip 15 is machined between the upper housing 11 and the lower housing 12. The upper and lower housings achieve side sealing by compressing the metal sealing strip 15 with the bolt preload. The electric heating element 2 is arranged axially inside the housing and is positioned by the conical hole 111 in the upper housing and the positioning plate 121 in the lower housing. To prevent the electric heating element 2 from moving inside the housing, the positioning plates 121 on the lower housing are respectively provided on both sides of the electric heating element. To prevent molten salt from leaking along the gap between the electric heating element and the housing, a groove 113 for placing a metal sealing ring 112 is provided at the conical hole of the upper housing connected to the conical boss. The conical boss 24 of the electric heating element and the conical hole 111 of the upper housing press the metal sealing ring 112 to achieve a seal.

[0019] like Figure 4 and Figure 5 As shown, the electric heating element 2 contains a double-turn spiral electric heating wire 21, and the electric heating element has flow holes 22 for molten salt to flow through. The electric heating wire is a high-temperature resistant metal electric heating wire, and the outer surface of the metal electric heating wire is an insulating ceramic 23. The selected insulating ceramic is a low-temperature sintering type, which can be molded integrally with the metal electric heating wire and then formed into an electric heating element through a sintering process. Since this embodiment uses insulating ceramic as the insulating material, the insulation performance is better and it is more suitable for high-voltage heating scenarios. Traditional low-voltage heating elements have limited resistance wire length, resulting in a small resistance value. Due to its own overcurrent capacity, its voltage withstand capability is weak. To adapt to high-voltage heating applications, the electric heating wire in this embodiment is double-turn or multi-turn spirally wound, which greatly increases the length of the electric heating wire and improves the high-voltage withstand capability of the electric heating element. During operation, the molten salt is heated through the flow holes 22. Since the thermal conductivity of the insulating ceramic is much higher than that of powdered insulating materials, the heating of the molten salt can be more uniform. There is a cavity between the two electric heating elements. Molten salt flows out of the flow hole in the form of a jet, and the molten salt is fully mixed in the cavity, thereby avoiding local overheating.

[0020] like Figures 5-6As shown, the conical protrusion of the electric heating element has an outlet hole 4 for the lead-out rod 3 to pass through. The electric heating element is connected to a high-voltage connecting line 5 via the lead-out rod 3. The connecting line can be connected to multiple sets of electric heating devices. If an electric heating device is damaged, only a short shutdown is required until the failed electric heating device is removed, after which the other electric heating devices can continue to work. The electric heating elements 2 are evenly distributed or gradually sparsely distributed in the shell along the flow direction. The heating power of the electric heating elements gradually decreases along the flow direction to ensure that the molten salt in the final section does not overheat. The electric heating device can be used as an electric heating module, with multiple sets connected in parallel inside the electric heater cylinder.

[0021] The embodiments described above are merely preferred embodiments of the present invention and are not intended to limit the present invention in any way. Other variations and modifications are possible without departing from the technical solutions described in the claims.

Claims

1. A high-voltage detachable molten salt electric heating device, comprising a housing, with a molten salt inlet and a molten salt outlet at both ends of the housing, characterized in that, The housing includes a detachable upper housing and a lower housing. Multiple electric heating elements are arranged along the axis inside the housing. Each electric heating element includes an insulating ceramic and an electric heating wire. The electric heating wire is covered with insulating ceramic. Lead rods are installed at both ends of the electric heating wire, extending from the upper end of the insulating ceramic into the upper housing. The electric heating elements are connected to a high-voltage connecting wire through the lead rods. Flow holes for molten salt to flow are provided on the insulating ceramic along the thickness direction.

2. The high-voltage detachable molten salt electric heating device according to claim 1, characterized in that, The upper housing is provided with a conical hole for positioning the power supply heating element. The insulating ceramic of the electric heating element is provided with a corresponding conical boss. The conical boss and the conical hole are positioned together. A lead-out hole is provided on the conical boss for the lead-out rod to lead out of the conical hole.

3. The high-voltage detachable molten salt electric heating device according to claim 1, characterized in that, Positioning plates are provided on both sides of the lower housing corresponding to the electric heating element.

4. The high-voltage detachable molten salt electric heating device according to claim 1, characterized in that, The upper and lower housings are fastened together by bolts.

5. A high-voltage detachable molten salt electric heating device according to claim 1, characterized in that, A groove is provided between the upper and lower shells, and a metal sealing strip is placed in the groove.

6. A high-voltage detachable molten salt electric heating device according to claim 1, characterized in that, The electric heating wire is arranged in a double or multi-turn spiral shape.

7. A high-voltage detachable molten salt electric heating device according to claim 1, characterized in that, The insulating ceramic is a low-temperature sintering type, integrally molded with an electric heating wire, and then formed by sintering.

8. A high-voltage detachable molten salt electric heating device according to claim 1, characterized in that, There is a cavity between adjacent electric heating elements inside the housing.

9. A high-voltage detachable molten salt electric heating device according to claim 1, characterized in that, The connecting wire is connected to the electric heating elements of multiple sets of electric heating devices via lead-out rods.

10. A high-voltage detachable molten salt electric heating device according to claim 2, characterized in that, An annular groove is provided at the connection between the tapered hole and the tapered boss on the upper shell, and a metal sealing ring is installed in the groove.

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