Shell structure of fused salt electric heater

Abstract

The invention relates to the field of fused salt electric heaters, in particular to a shell structure of a fused salt electric heater, and aims to solve the problem that the fused salt electric heater is uneven in heating and overtemperature, one side of a shell is open, an electric heating element is fixed at the opening of the shell and seals the opening of the shell, and an electric heating pipe of the electric heating element extends into the shell. N partition plates which are arranged in the length direction of the shell and divide the inner space of the shell are arranged in the shell, electric heating pipe through holes allowing electric heating pipes to penetrate through are formed in the partition plates, the n partition plates divide the inner space of the shell into n + 1 heat exchange areas, and medium circulation pipes are arranged on the upper side and the lower side of each heat exchanger correspondingly; the medium runner pipe serving as the inlet of the first heat exchange area is used for injecting molten salt, the medium runner pipe serving as the outlet of each heat exchange area is communicated with the medium runner pipe serving as the inlet of the next heat exchange area through a communicating pipe, and the (n + 1) th medium runner pipe serving as the outlet is used for discharging the molten salt. N is greater than 1 and is a positive integer, and the molten salt in the scheme ensures the heating uniformity.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of molten salt electric heater, in particular to a shell structure of molten salt electric heater. BACKGROUND

[0002] So far, most of the applications requiring high-power molten salt heating have adopted resistance-type molten salt electric heaters due to the mature resistance heating technology and the relatively simple structure of the required equipment. Currently, large and medium-sized electric heaters usually use sector baffles to support the typical multi-circular layout of U-shaped tube bundles. The sector baffle structure is simple and easy to manufacture, but the traditional sector baffle tube bundle has limitations, such as stagnant zones leading to uneven surface temperature distribution of the heating tubes, uneven heating of the molten salt, and easy overheating, thereby affecting the safety of the molten salt thermal storage system. For example, when the temperature is higher than 560℃, the molten salt will decompose rapidly, generating nitrite and releasing oxygen at the same time. After the decomposition of the solar salt, the thermal physical properties of the molten salt will change, and the decomposition products will accelerate the corrosion of the molten salt to the container. Due to the local overheating phenomenon of the molten salt electric heater, the maximum working temperature of the molten salt in the electric heater is often reduced in actual engineering applications to ensure safety, but this will greatly reduce the efficiency of the thermal storage system. Therefore, ensuring that the molten salt electric heater can quickly heat the molten salt without causing local overheating is the key to the safe and efficient operation of the molten salt electric heating system. SUMMARY

[0003] The purpose of the present application is to solve the problem of uneven heating and overheating of molten salt electric heaters. The present application proposes a shell structure of molten salt electric heater.

[0004] The purpose of the present application is achieved by a shell structure of molten salt electric heater, which comprises a shell and an electric heating element.

[0005] The shell is open on one side, and the electric heating element is fixed at the open end of the shell and seals the opening of the shell. The electric heating pipe of the electric heating element extends into the interior of the shell. The interior of the shell is provided with n partition plates arranged along the length direction of the shell and separating the interior space of the shell. The partition plates are provided with electric heating pipe through holes for passing through the electric heating pipe. The n partition plates separate the interior space of the shell into n+1 heat exchange zones. Each heat exchanger is provided with medium flow pipes on the upper and lower sides. The medium flow pipe of the first heat exchange zone as the inlet is used for injecting molten salt. The medium flow pipe of each heat exchange zone as the outlet is connected to the medium flow pipe of the next heat exchange zone as the inlet through a communication pipe. The medium flow pipe of the n+1 heat exchange zone as the outlet is used for discharging molten salt. n>1, and n is a positive integer.

[0006] Further, n=3.

[0007] Further, the medium flow pipe of the first heat exchange zone as the inlet is located above the shell.

[0008] Furthermore, the media flow pipe of the last heat exchange zone, serving as the outlet, is located above the outer shell.

[0009] Furthermore, each heat exchange zone has m inlet medium flow pipes on one side of the upper or lower side, and m outlet medium flow pipes on the other side of the upper or lower side, where m > 1 and m is a positive integer.

[0010] Furthermore, m=2.

[0011] Furthermore, a mixing zone is provided in the middle of each heat exchange zone, and a baffle is provided between two adjacent medium flow pipes in each heat exchange zone. The medium flowing in each medium flow pipe is guided by the baffles on both sides and flows with the medium in the mixing zone.

[0012] Furthermore, the partition is made of steel plate.

[0013] Furthermore, the angles between several partitions are the same.

[0014] Furthermore, the electric heating element is a flange-type electric heating tube.

[0015] Beneficial effects:

[0016] Molten salt enters heat exchange zone 1 through two inlet medium flow pipes, flowing radially. Figure 3 As shown in the flow direction, after heating and raising the temperature, the molten salt converges in the mixing zone, enhancing mixing, and then flows into the two outlet medium flow pipes. The molten salt undergoes transverse scouring heat exchange with the electric heating elements, and is heated in heat exchange zone 1 by the electric heating elements. It then enters the next heat exchange zone through connecting pipes. This process continues; multiple heat exchange zones are separated by partition plates, the structure of which is as follows... Figure 2 As shown, the hole is a through hole for the electric heating tube, which serves to support and allow the electric heating tube to pass through. The molten salt zone exchanges heat with the heat exchange tube to ensure uniform heating. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the outer shell structure of a molten salt electric heater according to the present invention;

[0018] Figure 2 This is a schematic diagram of the partition;

[0019] Figure 3 This is a schematic diagram of the heat exchange zone. Detailed Implementation

[0020] Specific implementation method 1: A shell structure for a molten salt electric heater, comprising a shell 1 and an electric heating element 2;

[0021] The shell 1 is open on one side, the electric heating element 2 is fixed at the open side of the shell 1 and seals the open side of the shell 1, the electric heating tube of the electric heating element 2 extends into the interior of the shell 1, the interior of the shell 1 is provided with n partition plates 3 arranged along the length direction of the shell 1 and separating the interior space of the shell 1, the partition plate 3 is provided with an electric heating tube through hole 3-1 for passing through the electric heating tube, the n partition plates 3 separate the interior space of the shell 1 into n+1 heat exchange zones, each heat exchanger is provided with a medium flow pipe 4 on the upper and lower sides, the medium flow pipe 4 of the first heat exchange zone as the inlet is used for injecting molten salt, the medium flow pipe 4 of each heat exchange zone as the outlet is communicated with the medium flow pipe 4 of the next heat exchange zone as the inlet through a communication pipe 5, and the medium flow pipe 4 of the n+1 heat exchange zone as the outlet is used for discharging molten salt. n>1, and n is a positive integer.

[0022] In the embodiment: the molten salt enters the first heat exchange zone from the medium flow pipe as the inlet, flows along the radial direction, and flows to the medium flow pipe as the outlet. Figure 3 The flow direction is shown, and the molten salt is transversely washed and exchanged with the electric heating element, and is heated and warmed by the electric heating element in the first heat exchange zone. It enters the next heat exchange zone through the connecting pipe. By analogy.

[0023] The plurality of heat exchange zones are separated by partition plates, and the structure of the partition plate is as shown in Figure 2 The hole is an electric heating tube through hole, which plays a supporting and passing role of the electric heating tube.

[0024] Specific embodiment two: a shell structure of a molten salt electric heater, n=3.

[0025] Other embodiments are the same as specific embodiment one.

[0026] Specific embodiment three: a shell structure of a molten salt electric heater, the medium flow pipe 4 of the first heat exchange zone as the inlet is located above the shell 1.

[0027] Other embodiments are the same as specific embodiment two.

[0028] Specific embodiment four: a shell structure of a molten salt electric heater, the medium flow pipe 4 of the last heat exchange zone as the outlet is located above the shell 1.

[0029] Other embodiments are the same as specific embodiment three.

[0030] Specific embodiment five: a shell structure of a molten salt electric heater, one side of the upper side or the lower side of each heat exchange zone is provided with m medium flow pipes 4 as the inlet, the other side of the upper side or the lower side of each heat exchange zone is provided with m medium flow pipes 4 as the outlet, m>1, and m is a positive integer.

[0031] Other embodiments are the same as specific embodiment one.

[0032] Sixth embodiment: a shell structure of a molten salt electric heater, m=2.

[0033] Other embodiments are the same as the fifth embodiment.

[0034] Seventh embodiment: a shell structure of a molten salt electric heater, each heat exchange zone is provided with a mixing zone 7, and a partition plate 6 is arranged between two adjacent medium flow pipes 4 in each heat exchange zone. The medium flowing in each medium flow pipe 4 is guided to flow by the partition plates 6 on both sides and flows into the mixing zone 7.

[0035] In this embodiment: the mixing zone strengthens the mixing of molten salt, ensures the uniformity of heating, and after heating and warming up, the molten salt is gathered in the mixing zone for strengthened mixing, and the molten salt and the electric heating element are subjected to transverse scouring heat exchange.

[0036] Other embodiments are the same as the fifth embodiment.

[0037] Eighth embodiment: a shell structure of a molten salt electric heater, the partition plate 6 is a steel plate.

[0038] Other embodiments are the same as the fifth embodiment.

[0039] Ninth embodiment: a shell structure of a molten salt electric heater, the angles between the plurality of partition plates 6 are the same.

[0040] Other embodiments are the same as the fifth embodiment.

[0041] Tenth embodiment: a shell structure of a molten salt electric heater, the electric heating element 2 is a flange type electric heating pipe.

[0042] In this embodiment: the electric heating element is a flange type electric heating pipe, and the electric heating element is easy to connect with the shell.

[0043] Other embodiments are the same as the first embodiment.

[0044] Embodiment:

[0045] The molten salt electric heater comprises a shell, a partition plate for electric heating elements, and a connecting pipe.

[0046] The shell is divided into four heat exchange zones by the partition plate, which are heat exchange zone 1, heat exchange zone 2, heat exchange zone 3, and heat exchange zone 4. The molten salt enters the heat exchange zone 1 from the medium flow pipe. There are two medium flow pipes as the inlet, which flow along the radial direction, such as Figure 3The molten salt and the electric heating element exchange heat through transverse flushing. The molten salt is heated in the heat exchange zone 1 by the electric heating element. The molten salt enters the next heat exchange zone through the connecting pipe. The process is repeated.

[0047] The multiple heat exchange zones are separated by the partition plates, and the structure of the partition plates is shown in Figure 2 , wherein the holes are through holes of the electric heating pipes, and the holes serve as supports and pass-throughs of the electric heating pipes.

[0048] The structure of the shell is shown in Figure 3 . The middle cylinder is the mixing zone, which strengthens the mixing of the molten salt and ensures the uniformity of heating. The annular part is divided into four sectors. The upper two sectors are inlets, and the lower two sectors are outlets. The two inlets are separated by a steel plate, and the two outlets are also separated by a steel plate. The number of the sectors can be selected according to the heating temperature.

Claims

1. A shell structure for a molten salt electric heater, characterized in that: It includes a housing (1) and an electric heating element (2); The outer shell (1) has an open side. The electric heating element (2) is fixed at the open side of the outer shell (1) and seals the open side of the outer shell (1). The electric heating tube of the electric heating element (2) extends into the interior of the outer shell (1). Inside the outer shell (1), there are n partition plates (3) arranged along the length of the outer shell (1) to divide the internal space of the outer shell (1). The partition plates (3) have through holes (3-1) for the electric heating tubes to pass through. The n partition plates (3) divide the internal space of the outer shell (1) into n+1 heat exchange zones. Each heat exchanger has a medium flow pipe (4) on both the upper and lower sides. The medium flow pipe (4) of the first heat exchange zone as the inlet is used to inject molten salt. The medium flow pipe (4) of each heat exchange zone as the outlet is connected to the medium flow pipe (4) of the next heat exchange zone as the inlet through a connecting pipe (5). The medium flow pipe (4) of the n+1th heat exchange zone as the outlet is used to discharge molten salt. n>1 and n is a positive integer.

2. The outer shell structure of a molten salt electric heater according to claim 1, characterized in that: n=3。 3. The outer shell structure of a molten salt electric heater according to claim 2, characterized in that: The medium flow pipe (4) of the first heat exchange zone, which serves as the inlet, is located above the outer shell (1).

4. The outer shell structure of a molten salt electric heater according to claim 3, characterized in that: The last heat exchange zone serves as the outlet medium flow pipe (4), located above the outer shell (1).

5. The outer shell structure of a molten salt electric heater according to claim 1, characterized in that: Each heat exchange zone has m medium flow pipes (4) as inlets on one side of the upper or lower side, and m medium flow pipes (4) as outlets on the other side of the upper or lower side, where m > 1 and m is a positive integer.

6. The outer shell structure of a molten salt electric heater according to claim 5, characterized in that: m=2。 7. The outer shell structure of a molten salt electric heater according to claim 5, characterized in that: Each heat exchange zone has a mixing zone (7) in the middle. A baffle (6) is provided between two adjacent medium flow pipes (4) in each heat exchange zone. The medium flowing in each medium flow pipe (4) is guided by the baffles (6) on both sides and flows with the medium in the mixing zone (7).

8. The outer shell structure of a molten salt electric heater according to claim 5, characterized in that: The partition (6) is made of steel plate.

9. The outer shell structure of a molten salt electric heater according to claim 5, characterized in that: Several partitions (6) are spaced at the same angle.

10. The shell structure of a molten salt electric heater according to claim 1, characterized in that: The electric heating element (2) is a flange-type electric heating tube.

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