Device and method for heating molten salt

Abstract

The present invention relates to a device and method for heating molten salt. The device comprises: a salt solution tank; at least one group of molten salt electrodes, each group of molten salt electrodes comprises a plurality of molten salt electrode boxes, and the plurality of molten salt electrode boxes are arranged at a position higher than the salt solution tank; at least one group of electrode inlet insulation pipes; at least one group of electrode outlet insulation pipes; at least one connecting pipe; at least one molten salt circulation pump, which is arranged in the connecting pipe; and a power supply device, which comprises multi-phase alternating current and the number of phases of the multi-phase alternating current is the same as the number of the plurality of molten salt electrode boxes, and each phase of the multi-phase alternating current of the power supply device is electrically connected to a corresponding one of the plurality of molten salt electrode boxes.

Description

Technical Field

[0001] The present invention relates to the field of molten salt heating, and more particularly to a device and method for heating molten salt using electrodes. Background Art

[0002] Molten salt is a heat transfer and heat storage medium with extremely good fluidity. It has the characteristics of low vapor pressure, wide applicable temperature range, stable chemical properties, large heat capacity, non-combustibility, low cost and easy preparation. It has broad application prospects in the field of heat storage, especially in the field of medium and high temperature heat storage.

[0003] At present, molten salt electric heating mostly adopts indirect heating by heat conduction using electric heating rods. The higher the working temperature of the heating wire, the shorter the service life. The better the insulation between the heating wire and the outer sleeve, the worse the heat transfer. Therefore, it is not conducive to the application of high-temperature and high-power electric heating of molten salt.

[0004] The electrode heating method is that electric current directly passes through molten salt to generate heat. The molten salt itself is a heating element, and there is no problem caused by indirect heating. However, due to the high electrical conductivity of molten salt, previous electrode heating technical means cannot control the current density on the electrode surface within a reasonable range, and it is difficult to avoid corrosion of the electrode material and electrolysis of the molten salt.

[0005] The information disclosed in this Background of the Invention section is only intended to enhance understanding of the general background of the invention and should not be taken as an acknowledgement or any form of suggestion that the information constitutes the prior art already known to a person skilled in the art. Summary of the invention

[0006] The purpose of the present invention is to provide a device and method for heating molten salt using electrodes. The present invention can successfully solve the technical problem of realizing low current density operation of electrodes in various ion conductors at any voltage, and is not only applicable to electrode heating of molten salt, but also to electrode heating of other ion conductors with fluidity. By using the present invention, molten salt electric heating equipment of various power sizes suitable for various voltage ranges can be designed and manufactured.

[0007] To achieve the above-mentioned object, the present invention provides a device for heating molten salt, which comprises: a salt solution tank; at least one group of molten salt electrodes, each group of molten salt electrodes comprises a plurality of molten salt electrode boxes, and the plurality of molten salt electrode boxes are arranged at a position higher than the salt solution tank; at least one group of electrode inlet insulating pipes, the number of pipes in each group of electrode inlet insulating pipes is the same as the number of a plurality of molten salt electrode boxes in each group of molten salt electrodes, a first end of the electrode inlet insulating pipe is fluidically connected to a corresponding one of the plurality of molten salt electrode boxes, and a second end of the electrode inlet insulating pipe is fluidically connected to a connecting pipe so that the molten salt can flow through the electrode inlet insulating pipe; at least one group of electrode outlet insulating pipes, the number of pipes in each group of electrode outlet insulating pipes is the same as the number of a plurality of molten salt electrode boxes in each group of molten salt electrodes, and a first end of the electrode outlet insulating pipe is fluidically connected to a corresponding one of the plurality of molten salt electrode boxes, and a second end of the electrode outlet insulating pipe is fluidically connected to a connecting pipe so that the molten salt can flow through the electrode outlet insulating pipe; The invention relates to a device for producing a molten salt electrode box having a plurality of molten salt electrodes, wherein the first end of the molten salt electrode box is fluidly connected to a corresponding one of the plurality of molten salt electrode boxes; the second end of the outlet electrode insulating pipe is fluidly connected to a salt solution box so that the molten salt can flow through the outlet electrode insulating pipe; at least one connecting pipe, the number of which is equal to the number of groups of inlet electrode insulating pipes, the first end of the connecting pipe is fluidly connected to the second end of the inlet electrode insulating pipe, and the second end of the connecting pipe is fluidly connected to the salt solution box; at least one molten salt circulation pump, the molten salt circulation pump is arranged in the connecting pipe and is used to pump the molten salt in the salt solution box to the molten salt electrode box; and a power supply device, which includes multi-phase alternating current and the number of phases of the multi-phase alternating current is the same as the number of the plurality of molten salt electrode boxes, and each phase of the multi-phase alternating current of the power supply device is electrically connected to a corresponding one of the plurality of molten salt electrode boxes.

[0008] In the above-mentioned device for heating molten salt, each group of molten salt electrodes has three molten salt electrode boxes, the multi-phase alternating current is three-phase alternating current, each group of inlet electrode insulating pipes includes three inlet electrode insulating pipes, and each group of outlet electrode insulating pipes includes three outlet electrode insulating pipes.

[0009] In the above-mentioned device for heating molten salt, the molten salt flowing in each pipe in each group of inlet electrode insulating pipes generates a first resistance value resistor with the same resistance value, and the molten salt flowing in each pipe in each group of outlet electrode insulating pipes generates a second resistance value resistor with the same resistance value.

[0010] In the above-mentioned device for heating molten salt, the electrode inlet insulating pipe is set at a specific angle with the horizontal plane, the angle of each pipe in each group of electrode inlet insulating pipes relative to the horizontal plane is the same, the length of each pipe in each group of electrode inlet insulating pipes is the same, and the flow cross-sectional area of ​​each pipe in each group of electrode inlet insulating pipes is the same, so as to ensure that the flow rate of each pipe in each group of electrode inlet insulating pipes is the same; the electrode outlet insulating pipe is set at a specific angle with the horizontal plane, the angle of each pipe in each group of electrode outlet insulating pipes relative to the horizontal plane is the same, the length of each pipe in each group of electrode outlet insulating pipes is the same, and the flow cross-sectional area of ​​each pipe in each group of electrode outlet insulating pipes is the same, so as to ensure that the flow rate of each pipe in each group of electrode outlet insulating pipes is the same.

[0011] In the above-mentioned device for heating molten salt, the molten salt electrode box is a container with a specific inner surface area made of corrosion-resistant and high-temperature resistant metal material, and has an electrode inlet insulating pipe connection port and an electrode outlet insulating pipe connection port. The first end of the electrode inlet insulating pipe is fluidically connected to the electrode inlet insulating pipe connection port of the corresponding molten salt electrode box, and the first end of the electrode outlet insulating pipe is fluidically connected to the electrode outlet insulating pipe connection port of the corresponding molten salt electrode box; and a conductive copper bus is connected to the outer wall of the molten salt electrode box.

[0012] According to the device for heating molten salt of the present invention, it further includes: at least one preheater, which is arranged in the salt solution tank and is used to heat the salt in the salt solution tank; and a controller, which is electrically connected to the preheater, the power supply device and the molten salt circulation pump to control the opening or closing of the preheater, the power supply or power off of the power supply device and the rotation speed of the molten salt circulation pump.

[0013] The present invention further provides a method for heating molten salt, which uses the above-mentioned device for heating molten salt, and the method comprises the following steps: using a preheater to heat the salt in the salt solution box, and heating the salt to a molten state capable of flowing; after the salt is in a molten state capable of flowing, closing the preheater; using a molten salt circulation pump to pump the molten salt in the salt solution box to a molten salt electrode box through a connecting pipe and an inlet electrode insulating pipe, and controlling the rotation speed of the molten salt circulation pump so that the amount of molten salt entering the molten salt electrode box is greater than the amount of molten salt flowing out of the molten salt electrode box through the outlet electrode insulating pipe; after the molten salt enters the molten salt electrode box through the connecting pipe and the inlet electrode insulating pipe, turning on a power supply device to supply power, thereby heating the molten salt; when the molten salt in the molten salt electrode box reaches a predetermined liquid level, controlling the rotation speed of the molten salt circulation pump so that the amount of molten salt entering the molten salt electrode box is equal to the amount of molten salt flowing out of the molten salt electrode box through the outlet electrode insulating pipe.

[0014] Through the above-mentioned exemplary embodiments, the advantages of the present invention are: the insulating pipe and the molten salt electrode can be designed according to any power supply voltage and heating power to form a suitable molten salt heating device. The device and method for electrode-type heating of molten salt of the present invention use the molten salt itself as the heating element, without heat conduction loss and the risk of dry burning of the heating wire. The only moving part is the molten salt circulation pump. Once the pump stops running, the heating will also stop. The most important thing is that the present invention successfully solves the technical problem of realizing low current density operation of electrodes in various high conductivity ion conductors at any working voltage. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 is a schematic diagram of an apparatus for heating molten salt according to an exemplary embodiment of the present invention.

[0016] Figure 2 is a schematic diagram of an apparatus for heating molten salt according to another exemplary embodiment of the present invention.

[0017] It should be understood that the drawings are not drawn to scale, but show various features that illustrate the basic principles of the invention in a slightly simplified manner. In the drawings of the present invention, the same reference numerals represent the same or equivalent parts of the present invention. DETAILED DESCRIPTION

[0018] Reference will be made in detail to various embodiments of the present invention, examples of which are shown in the accompanying drawings and are described below. Although the present invention will be described in conjunction with exemplary embodiments of the present invention, it will be understood that this specification is not intended to limit the present invention to those exemplary embodiments. On the contrary, the present invention is intended to cover not only the exemplary embodiments of the present invention, but also various alternatives, modifications, equivalents and other embodiments included within the spirit and scope of the present invention as defined in the appended claims.

[0019] Hereinafter, various exemplary embodiments of the present invention will be described in more detail with reference to the accompanying drawings.

[0020] Figure 1 An apparatus 100 for heating molten salt according to an exemplary embodiment of the present invention is shown, which may include:

[0021] A salt solution tank 10, which is made of high temperature resistant and corrosion resistant material and is grounded;

[0022] At least one group of molten salt electrodes 20, each group of molten salt electrodes 20 includes a plurality of molten salt electrode boxes, and the plurality of molten salt electrode boxes are arranged at a position higher than the salt solution tank 10;

[0023] At least one group of electrode inlet insulating pipes 30, the number of pipes in each group of electrode inlet insulating pipes is the same as the number of multiple molten salt electrode boxes in each group of molten salt electrodes, the first end (the upper end) of the electrode inlet insulating pipe 30 is fluidically connected to a corresponding molten salt electrode box in the multiple molten salt electrode boxes, and the second end (the lower end) of the electrode inlet insulating pipe 30 is fluidically connected to the connecting pipe 12, so that the molten salt can flow through the electrode inlet insulating pipe 30;

[0024] At least one group of outlet electrode insulation pipes 40, the number of pipes in each group of outlet electrode insulation pipes is the same as the number of multiple molten salt electrode boxes in each group of molten salt electrodes, the first end (the upper end) of the outlet electrode insulation pipe 40 is fluidically connected to a corresponding molten salt electrode box in the multiple molten salt electrode boxes, and the second end (the lower end) of the outlet electrode insulation pipe 40 is fluidically connected to the salt solution box 10, so that the molten salt can flow through the outlet electrode insulation pipe 40;

[0025] At least one preheater 11, which is arranged in the salt solution tank 10 to preheat the salt in the salt solution tank;

[0026] at least one connecting pipe 12, the number of the connecting pipes 12 is equal to the number of the groups of the inlet electrode insulating pipes, the first end of the connecting pipe 12 is fluidically connected to the second end of the inlet electrode insulating pipe 30, and the second end of the connecting pipe 12 is fluidically connected to the saline tank 10, so as to connect the corresponding inlet electrode insulating pipe 30 to the saline tank 10;

[0027] At least one molten salt circulation pump 13, which is arranged in the connecting pipe 12 and is used to pump the molten salt in the salt solution tank 10 to the molten salt electrode tank 20;

[0028] A power supply device 50, which includes a multi-phase alternating current, and the number of phases of the multi-phase alternating current is the same as the number of the plurality of molten salt electrode boxes, each phase of the multi-phase alternating current of the power supply device 50 is electrically connected to a corresponding one of the plurality of molten salt electrode boxes; and

[0029] The controller 60 is electrically connected to the preheater 11 , the power supply device 50 and the molten salt circulation pump 13 to control the on or off of the preheater 11 , the power supply device 50 and the rotation speed of the molten salt circulation pump 13 .

[0030] Specifically, in the present exemplary embodiment, the plurality of molten salt electrode boxes of each group of molten salt electrodes 20 is three (in Figure 1 The multiphase AC power is three-phase AC power (represented by L1, L2, L3), and each group of electrode inlet insulating pipes 30 includes three electrode inlet insulating pipes (in Figure 131, 32, 33 are used in the figure to represent respectively), each group of electrode insulation pipes 40 includes three electrode insulation pipes (in Figure 1 41, 42, 43 are used in the figure to represent respectively). Specifically, each phase L1, L2, L3 of the three-phase alternating current is electrically connected to three molten salt electrode boxes 21, 22, 23 respectively. It can be understood by those skilled in the art that the three-phase alternating current is only an example, and alternating current with more or fewer phases is also feasible, for example, two-phase alternating current is also feasible.

[0031] exist Figure 1 In the illustrated embodiment, only one group of molten salt electrodes 20 is shown, but those skilled in the art will appreciate that two, three or more groups of molten salt electrodes 20 may be provided, and each group of molten salt electrodes 20 includes a plurality of molten salt electrode boxes (illustrated as each group of molten salt electrodes 20 includes three molten salt electrode boxes 21, 22, 23). Accordingly, taking three-phase alternating current as an example, in the case of three groups of molten salt electrodes 20, the L1 phase of the three-phase alternating current is electrically connected to the first molten salt electrode box 21 of each group of molten salt electrodes 20, the L2 phase of the three-phase alternating current is electrically connected to the second molten salt electrode box 22 of each group of molten salt electrodes 20, and the L3 phase of the three-phase alternating current is electrically connected to the third molten salt electrode box 23 of each group of molten salt electrodes 20. Furthermore, Figure 1 Only one group of inlet electrode insulating pipes 30 and one group of outlet electrode insulating pipes 40 are shown, that is, one group of inlet electrode insulating pipes 30 and one group of outlet electrode insulating pipes 40 are provided for one group of molten salt electrodes 20. However, it can be understood by those skilled in the art that, as required, two or more groups of inlet electrode insulating pipes 30 and two or more groups of outlet electrode insulating pipes 40 can be provided for one group of molten salt electrodes 20.

[0032] Specifically, in the present exemplary embodiment, the molten salt flowing in each pipe in each group of inlet electrode insulating pipes 30 generates a first resistance value resistor with the same resistance value, that is, the resistance value generated by the molten salt flowing in each inlet electrode insulating pipe 31, 32, 33 is the same as each other. In addition, the molten salt flowing in each pipe in each group of outlet electrode insulating pipes 40 generates a second resistance value resistor with the same resistance value, that is, the resistance value generated by the molten salt flowing in each outlet electrode insulating pipe 41, 42, 43 is the same as each other.

[0033] In order to make the resistance values ​​generated by the molten salt flowing in each electrode inlet insulating pipe 31, 32, 33 the same, the electrode inlet insulating pipe can have a cross-section of a circular, elliptical, rectangular, hexagonal or other closed shape, each insulating pipe is a complete pipe or is composed of multiple short pipes, and each group of electrode inlet insulating pipes has the same flow cross-sectional area and the same length, so as to ensure that each pipe of each group of electrode inlet insulating pipes has the same resistance value after being filled with molten salt liquid. Further, the electrode inlet insulating pipe is inclined or vertically arranged at a specific angle to the horizontal plane. Preferably, the electrode inlet insulating pipe is arranged vertically to ensure that the molten salt flowing by gravity has enough flow to bring out all the heat. The angles of each pipe in each group of electrode inlet insulating pipes relative to the horizontal plane are the same, so as to ensure that each group of electrode inlet insulating pipes has the same flow cross-sectional area and the same length, so as to ensure that each pipe of each group of electrode inlet insulating pipes has the same resistance value after being filled with molten salt liquid.

[0034] Similarly, in order to make the resistance values ​​generated by the molten salt flowing in each outlet electrode insulating pipe 41, 42, 43 the same, the outlet electrode insulating pipe can have a cross-section of a circular, elliptical, rectangular, hexagonal or other closed shape, each insulating pipe is a complete pipe or is composed of multiple short pipes, and each group of outlet electrode insulating pipes has the same flow cross-sectional area and the same length, so as to ensure that each pipe of each group of outlet electrode insulating pipes has the same resistance value after being filled with molten salt liquid. Further, the outlet electrode insulating pipe is inclined or vertically arranged at a specific angle to the horizontal plane. Preferably, the outlet electrode insulating pipe is inclined at a specific angle to the horizontal plane to ensure that the molten salt flowing by gravity has enough flow to bring out all the heat. The angles of each pipe in each group of outlet electrode insulating pipes relative to the horizontal plane are the same, so as to ensure that each group of outlet electrode insulating pipes has the same flow cross-sectional area and the same length, so as to ensure that each pipe of each group of outlet electrode insulating pipes has the same resistance value after being filled with molten salt liquid.

[0035] In an exemplary embodiment of the present invention, the molten salt electrode boxes 21, 22, and 23 are containers with a specific inner surface area made of corrosion-resistant and high-temperature resistant metal materials, and have an inlet electrode insulation pipe connection port and an outlet electrode insulation pipe connection port. The first end of the inlet electrode insulation pipe is fluidically connected to the inlet electrode insulation pipe connection port of the corresponding molten salt electrode box, and the first end of the outlet electrode insulation pipe is fluidically connected to the outlet electrode insulation pipe connection port of the corresponding molten salt electrode box. Specifically, the connection port of the inlet electrode insulation pipe is arranged at the bottom of the molten salt electrode box 21, 22, and 23, and the outlet electrode insulation pipe connection port is arranged on the side of the molten salt electrode box 21, 22, and 23. Further, the outer wall of the molten salt electrode box is connected with a conductive copper busbar (not shown).

[0036] Figure 2 is a schematic diagram of an apparatus for heating molten salt according to another exemplary embodiment of the present invention. Figure 2 The device for heating molten salt shown is Figure 1 The devices for heating molten salt shown are the same, the only difference is the position of the inlet electrode insulation pipe connection port and the outlet electrode insulation pipe connection port. Specifically, in this embodiment, the inlet electrode insulation pipe connection port is arranged on the side of the molten salt electrode box 21, 22, 23, and the outlet electrode insulation pipe connection port is arranged at the bottom of the molten salt electrode box 21, 22, 23.

[0037] The method for heating molten salt using the above-mentioned device for heating molten salt is described in detail below. The method comprises the following steps: using a preheater 11 to heat the salt in the salt solution tank 10, and heating the salt to a molten state capable of flowing; after the salt is in a molten state capable of flowing, turning off the preheater 11; using a molten salt circulation pump 13 to pump the molten salt in the salt solution tank 10 through a connecting pipe 12 and an inlet electrode insulating pipe 30 to a molten salt electrode tank 20, and controlling the rotation speed of the molten salt circulation pump 13 so that the molten salt entering the molten salt electrode tank 20 is greater than the amount of molten salt flowing out of the molten salt electrode box 20 through the electrode outlet insulating pipe 40; after the molten salt enters the molten salt electrode box 20 through the connecting pipe 12 and the electrode inlet insulating pipe 30, the power supply device 50 is turned on to supply power, thereby heating the molten salt; when the molten salt in the molten salt electrode box 20 reaches a predetermined liquid level, the rotation speed of the molten salt circulation pump 13 is controlled so that the amount of molten salt entering the molten salt electrode box 20 is equal to the amount of molten salt flowing out of the molten salt electrode box 20 through the electrode outlet insulating pipe 40.

[0038] By the above-mentioned method for heating molten salt, molten salt is pumped from the salt solution tank 10 to the molten salt electrode tank 20 through the connecting pipe 12 and the inlet electrode insulating pipe 30, and then the molten salt in the molten salt electrode tank 20 flows into the salt solution tank 10 through the outlet electrode insulating pipe 40 by gravity, thereby forming a cycle. During the above-mentioned cycle, the power supply device 50 is turned on to supply power, so that the molten salt is heated.

[0039] The present invention takes three-phase alternating current as an example, and uses electrodes to heat molten salt, which is equivalent to using a star connection of three-phase alternating current. In the star connection, whether the neutral line is connected or not, the current will flow between the phase lines. If the three-phase loads are the same, the vector sum of the three-phase currents is zero, and thus the neutral line current is zero. Therefore, as long as the phase balance between the electrodes is ensured, that is, the molten salt flow rate and flow velocity flowing through the electrodes are the same, and the electrode sizes are the same, the electrodes can heat the molten salt.

[0040] In an exemplary embodiment of the present invention, when heated by the preheater 11, the salt can be heated to 200-275°C to put the salt in a molten state where it can flow, thereby forming the above-mentioned cycle; further, after turning on the power supply device 50, the molten salt can be heated to 300-600°C, or even up to 800°C.

[0041] In a preferred embodiment of the present invention, the molten salt electrode 20 is connected to three-phase alternating current, and the molten salt is heated during the above-mentioned circulation process. The heated high-temperature molten salt flows into the salt solution tank 10, and the molten salt is transported from the salt solution tank 10 to a high position by the molten salt circulation pump 13 and flows into the molten salt electrode tank 20 for continuous circulation. The molten salt also takes out heat during the circulation process.

[0042] The molten salt heated by the present invention can be used to provide high-temperature steam for industrial use at different temperatures through a heat exchanger, directly provide high-temperature steam to a power plant turbine, and provide steam at different temperatures for brewing, pharmaceuticals, mining, etc. Furthermore, the present invention can utilize the peak-shaving electricity of a power plant to convert electricity into heat for storage or use. The present invention can also directly utilize the electricity generated by waste clean energy to directly convert it into heat for storage or direct use.

[0043] In an exemplary embodiment of the present invention, after the molten salt circulation pump 13 stops, the molten salt in the molten salt electrode box 20, the inlet electrode insulating pipe 30 and the outlet electrode insulating pipe 40 all or substantially all falls back into the salt solution box 10 under the action of gravity, and the heating is also stopped. Specifically, the molten salt electrode box of the present invention has a container shape, and when heating, it is ensured that there is enough liquid level height inside the electrode to ensure that the electrode and the molten salt have enough contact area. When the heating is stopped, the molten salt can flow out of the electrode all or substantially all under the action of gravity to prevent freezing. In certain embodiments, there may be a small amount of molten salt retained inside the molten salt electrode box, but as long as it does not affect the flow of the molten salt when it is used again, there will be no adverse effect. When it is used again, the hot molten salt will melt the frozen molten salt, so that it keeps flowing.

[0044] In an exemplary embodiment of the present invention, according to the above-mentioned method for heating molten salt, when the heating is about to end, the rotation speed of the molten salt circulation pump 13 can be controlled so that the amount of molten salt entering the molten salt electrode box 20 is less than the amount of molten salt flowing out of the molten salt electrode box 20 through the electrode outlet insulating pipe 40. In this way, the liquid level in the molten salt electrode box 20 can be gradually reduced, and the heating is terminated when it is reduced to a certain height, thereby further improving the effect and making it easier to prevent the molten salt from freezing.

[0045] Through the above-mentioned exemplary embodiments, the advantages of the present invention are: the insulating pipe and the molten salt electrode can be designed according to any power supply voltage and heating power to form a suitable molten salt heating device. The device and method for electrode-type heating of molten salt of the present invention use the molten salt itself as the heating element, without heat conduction loss and the risk of dry burning of the heating wire. The only moving part is the molten salt circulation pump. Once the pump stops running, the heating will also stop. The most important thing is that the present invention successfully solves the technical problem of realizing low current density operation of electrodes in various high conductivity ion conductors at any working voltage.

[0046] Finally, in order to more clearly illustrate the present invention, the applicant provides the following examples. The size design of the insulating tube of the present invention regards the molten salt flowing through the insulating tube as a cylindrical resistor, whose resistance is R = ρ*L / S, where R is the resistance of the cylindrical resistor, ρ is the conductivity of the molten salt, L is the length of the insulating tube, and S is the inner diameter area of ​​the cross section of the insulating tube. When L / s reaches a certain value, the resistance of the molten salt flowing through the insulating tube can be very large, so after passing through the insulating tube, the molten salt current is very small.

[0047] The above descriptions of the specific exemplary embodiments of the present invention are presented for the purpose of illustration and description. They are not intended to be exhaustive or to limit the present invention to the precise form disclosed, and it is obvious that many modifications and changes can be made according to the above teachings. The selection and description of the exemplary embodiments are to explain certain principles of the present invention and their practical applications, so that those skilled in the art can make and use various exemplary embodiments of the present invention and their different alternative forms and modified forms. The scope of the present invention is intended to be limited by the appended claims and their equivalents.

Claims

1. A device for heating molten salt, characterized in that: include: Salt tank; At least one group of molten salt electrodes, each group of molten salt electrodes comprises a plurality of molten salt electrode boxes, and the plurality of molten salt electrode boxes are arranged at a position higher than the salt solution box; at least one group of inlet electrode insulating pipes, the number of pipes in each group of inlet electrode insulating pipes is the same as the number of multiple molten salt electrode boxes in each group of molten salt electrodes, the first end of the inlet electrode insulating pipe is fluidically connected to a corresponding one of the multiple molten salt electrode boxes, and the second end of the inlet electrode insulating pipe is fluidically connected to a connecting pipe so that molten salt can flow through the inlet electrode insulating pipe; At least one group of outlet electrode insulation pipes, the number of pipes in each group of outlet electrode insulation pipes is the same as the number of multiple molten salt electrode boxes in each group of molten salt electrodes, the first end of the outlet electrode insulation pipe is fluidically connected to a corresponding one of the multiple molten salt electrode boxes; the second end of the outlet electrode insulation pipe is fluidically connected to the salt solution box, so that molten salt can flow through the outlet electrode insulation pipe; at least one connecting pipe, the number of the connecting pipes being equal to the number of the groups of the inlet electrode insulating pipes, the first end of the connecting pipe being fluidically connected to the second end of the inlet electrode insulating pipe, and the second end of the connecting pipe being fluidically connected to the brine tank; at least one molten salt circulation pump, which is disposed in the connecting pipeline and is used to pump the molten salt in the salt solution tank to the molten salt electrode tank; and A power supply device, comprising a multi-phase alternating current, wherein the number of phases of the multi-phase alternating current is the same as the number of the plurality of molten salt electrode boxes, each phase of the multi-phase alternating current of the power supply device being electrically connected to a corresponding one of the plurality of molten salt electrode boxes; There are three molten salt electrode boxes, the multiphase alternating current is three-phase alternating current, each group of inlet electrode insulating pipes includes three inlet electrode insulating pipes, and each group of outlet electrode insulating pipes includes three outlet electrode insulating pipes; The molten salt flowing in each pipe in each group of inlet electrode insulation pipes generates resistors with the same first resistance value, and the molten salt flowing in each pipe in each group of outlet electrode insulation pipes generates resistors with the same second resistance value.

2. The device for heating molten salt according to claim 1, wherein: The electrode inlet insulation pipeline is arranged at an angle with the horizontal plane, the angles of the pipelines in each group of electrode inlet insulation pipelines relative to the horizontal plane are the same, the lengths of the pipelines in each group of electrode inlet insulation pipelines are the same, and the flow cross-sectional areas of the pipelines in each group of electrode inlet insulation pipelines are the same, so as to ensure that the flow rates of the pipelines in each group of electrode inlet insulation pipelines are the same; The electrode insulation pipes are arranged at an angle with the horizontal plane, the angles of the pipes in each group of electrode insulation pipes relative to the horizontal plane are the same, the lengths of the pipes in each group of electrode insulation pipes are the same, and the flow cross-sectional areas of the pipes in each group of electrode insulation pipes are the same, so as to ensure that the flow rates of the pipes in each group of electrode insulation pipes are the same.

3. The device for heating molten salt according to claim 1, wherein: The molten salt electrode box is made of corrosion-resistant and high-temperature resistant metal material to form a container with an inner surface area, and has an electrode inlet insulation pipe connection port and an electrode outlet insulation pipe connection port. The first end of the electrode inlet insulation pipe is fluidically connected to the electrode inlet insulation pipe connection port of the corresponding molten salt electrode box, and the first end of the electrode outlet insulation pipe is fluidically connected to the electrode outlet insulation pipe connection port of the corresponding molten salt electrode box; and a conductive copper bus is connected to the outer wall of the molten salt electrode box.

4. The device for heating molten salt according to any one of claims 1 to 3, further comprising: at least one preheater, which is disposed in the brine tank and is used to heat the salt in the brine tank; as well as A controller is electrically connected to the preheater, the power supply device and the molten salt circulation pump to control the opening or closing of the preheater, the power supply or power off of the power supply device and the rotation speed of the molten salt circulation pump.

5. A method for heating molten salt, using the device for heating molten salt according to claim 4, the method comprising the following steps: Using a preheater to heat the salt in the salt solution tank and heat the salt to a molten state capable of flowing; After the salt is in a molten state capable of flowing, the preheater is turned off; The molten salt in the salt solution box is pumped to the molten salt electrode box through the connecting pipe and the inlet electrode insulating pipe by using a molten salt circulation pump, and the rotation speed of the molten salt circulation pump is controlled so that the amount of molten salt entering the molten salt electrode box is greater than the amount of molten salt flowing out of the molten salt electrode box through the outlet electrode insulating pipe; After the molten salt enters the molten salt electrode box through the connecting pipe and the electrode inlet insulating pipe, the power supply device is turned on to supply power, thereby heating the molten salt; When the molten salt in the molten salt electrode box reaches a predetermined liquid level, the rotation speed of the molten salt circulation pump is controlled so that the amount of molten salt entering the molten salt electrode box is equal to the amount of molten salt flowing out of the molten salt electrode box through the electrode outlet insulating pipe.

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