Molten salt heating control method and device

Abstract

The invention relates to a fused salt heating control method and device, and the method comprises the steps: monitoring the temperature of the outer wall surface of a preset position of a fused salt storage tank through an armored thermocouple, calculating the temperature distribution data of the inner wall surface of the fused salt storage tank according to the temperature of the outer wall surface of the preset position of the fused salt storage tank, and calculating the temperature distribution data of the inner wall surface of the fused salt storage tank according to the temperature distribution data of the inner wall surface of the fused salt storage tank. And the temperature distribution condition of the fused salt in the fused salt storage tank is determined, and the heating power of the electric heater and the heating power of the electric tracing band are adjusted according to the temperature distribution condition of the fused salt. Compared with the prior art, the temperature information of the outer wall surfaces of different positions of the fused salt storage tank is collected through the sheathed thermocouples, the temperature distribution condition of the fused salt in the fused salt storage tank is further determined, and then the temperature distribution uniformity of the fused salt is enhanced by dynamically adjusting the heating power of the electric heater and the electric tracing band, so that the temperature distribution uniformity of the fused salt is improved. The thermal stress generated by the temperature gradient is reduced, the device can adapt to various molten salt storage tanks, the melting speed of the molten salt is increased, and the energy consumption is reduced.

Description

Technical Field

[0001] This disclosure relates to the field of molten salt energy storage technology, and in particular to a molten salt heating control method and apparatus. Background Technology

[0002] Currently, molten salt in cryogenic molten salt storage tanks and pipelines is usually heated by electric heat tracing devices, mainly using two methods: impedance heating and insulated cable heat tracing.

[0003] Impedance heating utilizes the inherent resistance of the molten salt pipeline, applying voltage to heat it. However, it is only suitable for equipment with high impedance and cannot be used for small storage tanks or molten salt pipelines. Insulated cable tracing, which involves wrapping heating cables around the pipeline, can be used for small storage tanks or pipelines, but it suffers from low heating efficiency, slow heating speed, uneven molten salt temperature distribution, and an inability to quickly respond to emergencies. Furthermore, existing methods may cause the molten salt to solidify during flow, posing a risk of system damage and shutdown. Therefore, there is an urgent need for a adaptable, efficient, and rapidly responsive molten salt heating and melting method to improve the operating efficiency of molten salt systems while preventing solidification during flow. Summary of the Invention

[0004] To address the aforementioned technical problems, this disclosure provides a molten salt heating control method and apparatus to improve the working efficiency of the molten salt system while preventing the molten salt from solidifying during the flow process.

[0005] In a first aspect, embodiments of this disclosure provide a method for controlling the heating of molten salt, the method comprising:

[0006] The temperature of the outer wall surface of the molten salt storage tank at a preset location is monitored using armored thermocouples.

[0007] Calculate the temperature distribution data of the inner wall of the molten salt storage tank based on the outer wall temperature at a preset location of the molten salt storage tank.

[0008] Based on the temperature distribution data of the inner wall surface of the molten salt storage tank, determine the temperature distribution of the molten salt inside the tank.

[0009] The heating power of the electric heater and the electric heating tape is adjusted according to the temperature distribution of the molten salt.

[0010] In some embodiments, the armored thermocouple is installed at a predetermined position on the molten salt storage tank, the predetermined position including the top, upper side, and lower side; the temperature probe of the armored thermocouple is fixed to the outer wall of the molten salt storage tank for measuring the temperature of the outer wall.

[0011] In some embodiments, the electric heater is located at the lower part of the molten salt storage tank, and the electric heater includes a plurality of electric heating rods arranged in a horizontal row.

[0012] In some embodiments, the electric heating tape is wrapped around the upper part of the outer surface of the molten salt storage tank and closely adheres to the outer wall of the molten salt storage tank.

[0013] In some embodiments, adjusting the heating power of the electric heater and the electric heating tape according to the temperature distribution of the molten salt includes:

[0014] Based on the results of numerical simulation analysis, a power allocation table is generated;

[0015] Select a power allocation method from the power allocation table that matches the temperature distribution of the molten salt;

[0016] Adjust the heating power of each electric heating rod and electric heating tape in the electric heater according to the power distribution method.

[0017] In some embodiments, adjusting the heating power of each electric heating rod and electric heating tape in the electric heater according to the power distribution method includes:

[0018] According to the power distribution method, the start-up and shutdown of each electric heating rod and the heating power in the electric heater are controlled to improve the uniformity of molten salt temperature distribution.

[0019] According to the power distribution method, the power of the electric heating tape is adjusted to reduce the temperature difference between the upper and lower molten salt in the molten salt storage tank.

[0020] In some embodiments, calculating the inner wall temperature distribution data of the molten salt storage tank based on the outer wall temperature at a preset location of the molten salt storage tank includes:

[0021] Based on the heat conduction equation, and combined with the outer wall temperature at the preset location and the material parameters of the molten salt tank, the inner wall temperature distribution data of the molten salt tank is calculated by using the finite difference method.

[0022] In some embodiments, the method further includes:

[0023] By using the combined heating of electric heaters and electric heating tapes, the number of electric heating rods inside molten salt storage tanks and pipelines can be reduced while keeping the total heating power constant, thereby reducing the flow resistance of molten salt.

[0024] When the temperature of the molten salt drops to near its melting point, the electric heater and electric heating tape are quickly activated to heat it and prevent the molten salt from solidifying and forming a freeze blockage.

[0025] Secondly, this disclosure provides a molten salt heating control device, which includes a molten salt storage tank, an electric heater, an electric heating tape, a sheathed thermocouple, a temperature signal processor, a heating power distribution program, a heating device controller, and signal lines;

[0026] The molten salt storage tank is a container for storing solid and liquid molten salt;

[0027] The electric heater is located inside the molten salt storage tank at the lower position. The electric heater includes multiple electric heating rods arranged in a horizontal row.

[0028] The electric heating tape is wrapped around the upper part of the outer surface of the molten salt storage tank and is in close contact with the outer wall of the molten salt storage tank.

[0029] The armored thermocouple is installed at a predetermined position on the molten salt storage tank, including the top, upper side, and lower side; the temperature probe of the armored thermocouple is fixed to the outer wall of the molten salt storage tank for measuring the temperature of the outer wall.

[0030] In some embodiments, the temperature signal processor is used to acquire the outer wall temperature of the molten salt storage tank at a preset location monitored by the armored thermocouple via the signal line, and convert the outer wall temperature into a digital signal;

[0031] The heating power distribution program is used to receive the digital signal converted by the temperature signal processor to obtain the outer wall temperature of the molten salt storage tank at a preset position; calculate the inner wall temperature distribution data of the molten salt storage tank based on the outer wall temperature at the preset position; determine the temperature distribution of the molten salt inside the molten salt storage tank based on the inner wall temperature distribution data; adjust the heating power of the electric heater and the electric heating tape based on the temperature distribution of the molten salt, and generate the processing result.

[0032] The heating device controller is used to receive the processing results generated by the heating power allocation program, and control the heating power of the electric heater and the electric heating tape according to the processing results.

[0033] Thirdly, embodiments of this disclosure provide an electronic device, including:

[0034] Memory;

[0035] Processor; and

[0036] Computer programs;

[0037] The computer program is stored in the memory and configured to be executed by the processor to implement the method as described in the first aspect.

[0038] Fourthly, embodiments of this disclosure provide a computer-readable storage medium having a computer program stored thereon, the computer program being executed by a processor to implement the method as described in the first aspect.

[0039] Fifthly, embodiments of this disclosure also provide a computer program product comprising a computer program or instructions that, when executed by a processor, implement the method described in the first aspect.

[0040] The molten salt heating control method and apparatus provided in this disclosure monitor the outer wall temperature of a preset location in a molten salt storage tank using sheathed thermocouples. Based on the outer wall temperature at the preset location, the temperature distribution data of the inner wall of the molten salt storage tank is calculated. Based on the inner wall temperature distribution data, the temperature distribution of the molten salt inside the tank is determined. The heating power of the electric heater and the electric heating tape is adjusted according to the molten salt temperature distribution. Compared to existing technologies, this disclosure uses sheathed thermocouples to collect temperature information at different locations on the outer wall of the molten salt storage tank, further determining the temperature distribution of the molten salt inside the tank. Then, by dynamically adjusting the heating power of the electric heater and the electric heating tape, the uniformity of the molten salt temperature distribution is enhanced, reducing thermal stress caused by temperature gradients. This method can adapt to various molten salt storage tanks, increase the melting rate of the molten salt, and reduce energy consumption. Attached Figure Description

[0041] The accompanying drawings, which are incorporated in and form a part of this specification, illustrate embodiments consistent with this disclosure and, together with the description, serve to explain the principles of this disclosure.

[0042] To more clearly illustrate the technical solutions in the embodiments of this disclosure or the prior art, the accompanying drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, for those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0043] Figure 1 A flowchart of the molten salt heating control method provided in the embodiments of this disclosure;

[0044] Figure 2 A flowchart of a molten salt heating control method provided in another embodiment of this disclosure;

[0045] Figure 3 This is a schematic diagram of the molten salt heating control device provided in an embodiment of the present disclosure;

[0046] Figure 4 Schematic diagrams illustrating different arrangement methods provided in embodiments of this disclosure;

[0047] Figure 5A schematic diagram illustrating the variation of average molten salt temperature with heating time under different arrangement configurations provided in the embodiments of this disclosure;

[0048] Figure 6 This diagram illustrates the change in the liquid phase ratio of molten salt with heating time under different arrangement configurations provided in the embodiments of this disclosure.

[0049] Figure 7 This is a schematic diagram illustrating the change of molten salt temperature difference with heating time under different arrangement configurations provided in the embodiments of this disclosure.

[0050] Figure 8 This is a schematic diagram illustrating the change of the liquid phase of molten salt with heating time under different heating power distributions provided in this embodiment of the disclosure.

[0051] Figure 9 This is a schematic diagram illustrating the change of molten salt temperature difference with heating time under different heating power distributions provided in this embodiment of the disclosure;

[0052] Figure 10 A schematic diagram showing the arrangement of the electric heating tape provided in the embodiments of this disclosure;

[0053] Figure 11 A schematic diagram showing the change of the liquid phase of molten salt with heating time when the tracing heat is arranged on the upper side as provided in the embodiments of this disclosure;

[0054] Figure 12 A schematic diagram illustrating the change of molten salt temperature difference with heating time when a heat tracing cable is arranged on the upper side as provided in an embodiment of this disclosure;

[0055] Figure 13 This is a schematic diagram showing the change in the liquid phase of molten salt with heating time when the heat tracing tape is arranged on the lower side as provided in an embodiment of this disclosure. Detailed Implementation

[0056] To better understand the above-mentioned objectives, features, and advantages of this disclosure, the solutions disclosed herein will be further described below. It should be noted that, unless otherwise specified, the embodiments and features described herein can be combined with each other.

[0057] Numerous specific details are set forth in the following description in order to provide a full understanding of this disclosure, but this disclosure may also be implemented in other ways different from those described herein; obviously, the embodiments in the specification are only some, and not all, of the embodiments of this disclosure.

[0058] Currently, molten salt in cryogenic molten salt storage tanks and pipelines is usually heated by electric heat tracing devices, mainly using two methods: impedance heating and insulated cable heat tracing.

[0059] Impedance heating utilizes the inherent resistance of the molten salt pipeline, applying voltage to heat it. However, it is only suitable for equipment with high impedance and cannot be used for small storage tanks or molten salt pipelines. Insulated cable tracing, which involves wrapping heating cables around the pipeline, can be used for small storage tanks or pipelines, but it suffers from low heating efficiency, slow heating speed, uneven molten salt temperature distribution, and an inability to quickly respond to emergencies. Furthermore, existing methods may cause the molten salt to solidify during flow, posing a risk of system damage and shutdown. Therefore, there is an urgent need for a adaptable, efficient, and rapidly responsive molten salt heating and melting method to improve the operating efficiency of molten salt systems while preventing solidification during flow.

[0060] To address this problem, this disclosure provides a method for controlling molten salt heating, which will be described below with reference to specific embodiments.

[0061] Figure 1 This is a flowchart of a molten salt heating control method provided in an embodiment of the present disclosure. This method can be applied to scenarios where molten salt heating is controlled, which can improve the temperature distribution uniformity of molten salt, reduce the thermal stress caused by temperature gradient, and increase the melting rate of molten salt, thereby improving the heating efficiency and energy utilization efficiency of molten salt.

[0062] It is understood that the molten salt heating control method provided in this disclosure can also be applied in other scenarios.

[0063] The following is about Figure 1 The molten salt heating control method shown is described below, which includes the following steps:

[0064] S101. Monitor the outer wall temperature of the molten salt storage tank at a preset location using armored thermocouples.

[0065] In this step, such as Figure 3 As shown, the armored thermocouple can be installed at a preset position in the molten salt storage tank, and the temperature of the outer wall surface at the preset position in the molten salt storage tank can be monitored through the armored thermocouple.

[0066] In some embodiments, the armored thermocouple is installed at a predetermined position on the molten salt storage tank, the predetermined position including the top, upper side, and lower side; the temperature probe of the armored thermocouple is fixed to the outer wall of the molten salt storage tank for measuring the temperature of the outer wall.

[0067] Optionally, the preset position may include the top, upper side, and lower side, or other positions, without specific limitations.

[0068] S102. Calculate the temperature distribution data of the inner wall of the molten salt storage tank based on the outer wall temperature at a preset location of the molten salt storage tank.

[0069] In this step, after obtaining the outer wall temperature at a preset location of the molten salt storage tank, the inner wall temperature distribution data of the molten salt storage tank can be calculated based on the outer wall temperature at the preset location of the molten salt storage tank.

[0070] S103. Based on the temperature distribution data of the inner wall surface of the molten salt storage tank, determine the temperature distribution of the molten salt inside the molten salt storage tank.

[0071] In this step, the temperature distribution of the molten salt inside the molten salt storage tank is further determined based on the temperature distribution data of the inner wall surface of the molten salt storage tank.

[0072] S104. Adjust the heating power of the electric heater and the electric heating tape according to the temperature distribution of the molten salt.

[0073] In this step, after determining the temperature distribution of the molten salt in the molten salt storage tank, the heating power of the electric heater and the electric heating tape can be adjusted according to the temperature distribution of the molten salt. By dynamically adjusting the heating power of the electric heater and the electric heating tape, the uniformity of the temperature distribution of the molten salt can be enhanced, and the thermal stress caused by the temperature gradient can be reduced.

[0074] In some embodiments, the electric heater is located at the lower part of the molten salt storage tank, and the electric heater includes a plurality of electric heating rods arranged in a horizontal row.

[0075] In some embodiments, the spacing between the electric heating rods and the height of the electric heating rods from the bottom of the tank are configured. Through the parameter design of the spacing and height of the electric heating rods from the bottom of the tank in this embodiment, liquid molten salt can flow upwards from the middle of the heating rods in the initial heating stage, forming two vortices, one on the left and one on the right. As heating progresses, the vortices converge and merge, promoting the uniformity of the liquid molten salt temperature. Furthermore, the different densities of the liquid molten salt in the lower and upper parts create a tendency for the internal molten salt to flow vertically, improving the heating efficiency and energy utilization efficiency of the molten salt.

[0076] This disclosure compares the effects of various electric heating rod arrangement methods on the molten salt melting process, showing that the horizontal arrangement is the most effective; therefore, the horizontal arrangement of the electric heating rods is adopted. The various electric heating rod arrangement methods include horizontal, vertical, inverted triangle, upright triangle, small inverted triangle, and small upright triangle.

[0077] In some embodiments, the electric heating tape is wrapped around the upper part of the outer surface of the molten salt storage tank and closely adheres to the outer wall of the molten salt storage tank.

[0078] In this embodiment, the electric heating cable arranged on the upper part of the outer surface of the molten salt tank can effectively reduce the temperature difference between the upper and lower molten salt by providing heat to the upper molten salt, thereby reducing the thermal stress caused by the temperature gradient of the molten salt.

[0079] This embodiment of the invention monitors the outer wall temperature at a preset location of a molten salt storage tank using armored thermocouples. Based on this outer wall temperature, it calculates the inner wall temperature distribution data of the molten salt storage tank. Then, based on this inner wall temperature distribution data, it determines the temperature distribution of the molten salt inside the tank. Finally, it adjusts the heating power of the electric heater and the electric heating tape according to the molten salt temperature distribution. Compared to existing technologies, this embodiment uses armored thermocouples to collect temperature information at different locations on the outer wall of the molten salt storage tank, further determining the temperature distribution of the molten salt inside the tank. Then, by dynamically adjusting the heating power of the electric heater and the electric heating tape, it enhances the uniformity of the molten salt temperature distribution, reduces thermal stress caused by temperature gradients, adapts to various molten salt storage tanks, increases the melting rate of the molten salt, and reduces energy consumption.

[0080] Figure 2 A flowchart of a molten salt heating control method provided in another embodiment of this disclosure is shown below. Figure 2 As shown, the method includes the following steps:

[0081] S301. Monitor the outer wall temperature of the molten salt storage tank at a preset location using armored thermocouples.

[0082] Specifically, the implementation process and principle of S301 and S101 are the same, and will not be repeated here.

[0083] S302. Based on the heat conduction equation, and combining the outer wall temperature at the preset location with the material parameters of the molten salt tank, the inner wall temperature distribution data of the molten salt tank is calculated by solving the finite difference method.

[0084] In this step, after obtaining the outer wall temperature at a preset location of the molten salt storage tank, the inner wall temperature distribution data of the molten salt storage tank can be calculated using the finite difference method based on the heat conduction equation and the outer wall temperature at the preset location combined with the material parameters of the molten salt storage tank.

[0085] S303. Based on the temperature distribution data of the inner wall surface of the molten salt storage tank, determine the temperature distribution of the molten salt inside the molten salt storage tank.

[0086] Specifically, the implementation process and principle of S303 and S103 are the same, and will not be repeated here.

[0087] S304. Based on the results of numerical simulation analysis, generate a power allocation table.

[0088] In this step, simulation analysis will be performed, and a power allocation table will be generated based on the results. Optionally, numerical simulation analysis can be performed using simulation software; there is no limitation on this method. The power allocation table is used to characterize the power allocation methods corresponding to different temperature distributions.

[0089] S305. Select a power allocation method from the power allocation table that matches the temperature distribution of the molten salt.

[0090] In this step, after determining the temperature distribution of the molten salt in the molten salt storage tank, a power allocation method matching the temperature distribution of the molten salt is selected from the power allocation table. The power allocation method is used to characterize the power allocation of the electric heater and the electric heating tape.

[0091] S306. Adjust the heating power of each electric heating rod and electric heating tape in the electric heater according to the power distribution method.

[0092] In this step, the heating power of each electric heating rod and the electric heating tape in the electric heater is adjusted according to the power distribution method. For example, the power of electric heating rod A is adjusted to 'a', the power of electric heating rod B is adjusted to 'b', and the power of the electric heating tape is adjusted to 'c'.

[0093] In some embodiments, S306 may include, but is not limited to, S3061 and S3062:

[0094] S3061. According to the power distribution method, control the start-up and shutdown of each electric heating rod in the electric heater and the heating power to improve the uniformity of molten salt temperature distribution.

[0095] In this embodiment, based on the power distribution method, the start-up and shutdown and heating power of each electric heating rod in the electric heater are controlled. The distribution of heating power among different electric heating rods also has the effect of improving the uniformity of molten salt temperature distribution.

[0096] S3062. According to the power distribution method, adjust the power of the electric heating tape to reduce the temperature difference between the upper and lower molten salt in the molten salt storage tank.

[0097] In this embodiment, the power of the electric heating cable is adjusted based on the power distribution method, thereby reducing the temperature difference between the upper and lower molten salt in the molten salt storage tank and reducing the thermal stress caused by the molten salt temperature gradient.

[0098] S307. By using the combined heating of electric heaters and electric heating tapes, while keeping the total heating power constant, the number of electric heating rods inside the molten salt storage tank and pipelines is reduced to decrease the flow resistance of the molten salt.

[0099] In this step, by using the combined heating of the electric heater and the electric heating tape, the number of electric heating rods in the molten salt storage tank and molten salt pipeline can be reduced while keeping the total heating power constant. This reduces the flow resistance loss caused by the built-in electric heater in the entire molten salt energy storage system and improves the system's operating efficiency.

[0100] S308. When the temperature of the molten salt drops to near the melting point, quickly start the electric heater and electric heating tape to heat it up, so as to prevent the molten salt from solidifying and forming a freeze blockage.

[0101] In this step, when the temperature of the molten salt drops to near the melting point, the electric heater and electric heating tape are quickly started to heat it up to prevent the molten salt from solidifying and forming a freeze blockage.

[0102] This embodiment monitors the outer wall temperature of a molten salt storage tank at a predetermined location using armored thermocouples. Based on the heat conduction equation and combining the outer wall temperature at the predetermined location with the material parameters of the molten salt storage tank, the finite difference method is used to calculate the inner wall temperature distribution data of the molten salt storage tank. Based on this data, the temperature distribution of the molten salt inside the tank is determined. Furthermore, based on the results of numerical simulation analysis, a power allocation table is generated, and a power allocation method matching the molten salt temperature distribution is selected from this table. Then, according to the power allocation method, the heating power of each heating rod and heating cable in the electric heater is adjusted. Through the synergistic heating of the electric heater and heating cable, while maintaining a constant total heating power, the number of heating rods inside the molten salt storage tank and pipelines is reduced to decrease the flow resistance of the molten salt. When the molten salt temperature drops to near its melting point, the electric heater and heating cable are quickly activated to prevent the molten salt from solidifying and causing freezing blockage. Through this method, the embodiments of this disclosure can improve the temperature distribution uniformity of molten salt, reduce the thermal stress caused by temperature gradient, increase the melting rate of molten salt, reduce energy consumption, thereby improving the working efficiency of the molten salt system, while preventing the molten salt from solidifying during the flow process.

[0103] Figure 3 This is a schematic diagram of the molten salt heating control device provided in an embodiment of this disclosure. The molten salt heating control device provided in this embodiment can execute the processing flow provided in the molten salt heating control method embodiment, such as… Figure 3 As shown, the molten salt heating control device includes: a molten salt storage tank 1, an electric heater 2, an electric heating tape 3, an armored thermocouple 4, a temperature signal processor 5, a heating power distribution program 6, a heating device controller 7, and a signal line 8; wherein, the molten salt storage tank 1 is a storage container for solid and liquid molten salt; the electric heater 2 is located at the lower part of the molten salt storage tank, and the electric heater includes multiple electric heating rods arranged in a horizontal row; the electric heating tape 3 is wrapped around the upper part of the outer surface of the molten salt storage tank and closely adheres to the outer wall of the molten salt storage tank; the armored thermocouple 4 is installed at preset positions on the molten salt storage tank, the preset positions including the top, upper side, and lower side; the temperature probe of the armored thermocouple is fixed to the outer wall of the molten salt storage tank for measuring the temperature of the outer wall.

[0104] Optionally, the temperature signal processor 5 is used to acquire the outer wall temperature of the molten salt storage tank at a preset position monitored by the sheathed thermocouple via the signal line 8, and convert the outer wall temperature into a digital signal; the heating power distribution program 6 is used to receive the digital signal converted by the temperature signal processor, obtain the outer wall temperature of the molten salt storage tank at the preset position; calculate the inner wall temperature distribution data of the molten salt storage tank based on the outer wall temperature of the preset position; determine the temperature distribution of the molten salt in the molten salt storage tank based on the inner wall temperature distribution data of the molten salt storage tank; adjust the heating power of the electric heater and the electric heating tape based on the temperature distribution of the molten salt, and generate a processing result; the heating device controller 7 is used to receive the processing result generated by the heating power distribution program, and control the heating power of the electric heater and the electric heating tape based on the processing result.

[0105] Figure 3 The molten salt heating control device shown in the embodiment can be used to execute the technical solution of the above method embodiment. Its implementation principle and technical effect are similar, and will not be described again here.

[0106] This disclosure explores the influence of various electric heating rod arrangements on the molten salt melting process, such as... Figure 4 As shown, various electric heating rods can be arranged in different ways, including horizontal, vertical, inverted triangle, upright triangle, small inverted triangle, and small upright triangle.

[0107] Taking a square cavity as an example, we first explore the influence of different heating rod arrangements on the melting process of molten salt. The dimensional parameters of the square cavity and the electric heating rods are as follows: Figure 4 As shown. Figure 5 This is a schematic diagram illustrating the variation of the average temperature of molten salt with heating time under different arrangement configurations provided in embodiments of this disclosure. Figure 6 This diagram illustrates the change in the liquid phase ratio of molten salt with heating time under different arrangement configurations provided in embodiments of this disclosure. Figure 7 This is a schematic diagram illustrating the change of molten salt temperature difference with heating time under different arrangement methods provided in the embodiments of this disclosure. Figures 5 to 7The changes in average molten salt temperature, liquid-to-liquid ratio, and molten salt temperature difference over time are presented under six different electric heating rod arrangement strategies. The molten salt temperature difference is defined as the difference between the highest and lowest temperatures of the molten salt inside the lower cavity at the same heating moment; this parameter reflects the temperature uniformity of the molten salt inside the lower cavity at a given moment. It can be seen that in the horizontal, equilateral triangle, and small equilateral triangle arrangements, most of the heating power is distributed in the lower part of the square cavity, resulting in a higher liquid-to-liquid ratio of the molten salt inside the tubes and lower average molten salt temperature and molten salt temperature difference. Therefore, these three arrangements are significantly better than the other three arrangements. Around 25 minutes into the heating process, the liquid-to-liquid ratio of the molten salt in the square cavity using the horizontal, equilateral triangle, and small equilateral triangle electric heating rod arrangements reached 1, while the liquid-to-liquid ratio of the small inverted triangle arrangement, which had the highest liquid-to-liquid ratio among the other three, was less than 0.9, a difference of more than 10%. This indicates that concentrating the heating power in the lower part of the square cavity is far more effective than concentrating it in the upper part.

[0108] For the three arrangement methods—horizontal, equilateral triangle, and small equilateral triangle—that can all completely melt the molten salt in the cavity within 25 minutes, analysis from the perspective of molten salt temperature uniformity is necessary. Figure 6 and Figure 7 It can be seen that during the heating phase (13-21 minutes), the molten salt ratio of the equilateral triangle and small equilateral triangle arrangements slightly outpaced that of the horizontal arrangement, and the molten salt temperature difference was also about 20K lower. This is because the distance between the three heating rods in these two arrangements is greater than that in the horizontal arrangement, allowing them to influence a wider area of ​​the low-temperature molten salt. However, it should also be noted that after the heating time reaches 21 minutes, the molten salt temperature difference in both arrangements begins to gradually increase, while the molten salt ratio has not yet reached 1. This indicates that these two arrangements also suffer from the drawback of the three less desirable arrangements (vertical, etc.) where natural convection cannot affect some low-temperature molten salt in melting dead zones. In contrast, the horizontal arrangement not only surpasses the equilateral triangle and small equilateral triangle arrangements in the later stages of heating, but also exhibits a lower molten salt temperature difference when the average molten salt temperature is essentially the same. This suggests that the horizontal arrangement has the best overall performance. When the heating time reaches 25 minutes, the horizontal arrangement not only achieves a molten salt ratio of 1, but also has the lowest average temperature of molten salt and temperature difference among the six arrangements. At this time, the temperature difference of molten salt is only about 30K, and the molten salt temperature difference curve has not yet entered the rising stage. This indicates that this arrangement can make the most of the natural convection effect of molten salt in the closed tube.

[0109] Next, we investigated the effect of the power distribution method of the electric heating rods on the molten salt heating process, keeping the total heat flux density of the three electric heating rods the same at 24000 W·m. -2The heat flux density of the intermediate electric heating rod was changed to 5000, 6000, 7000, 8000, 9000, 10000 and 11000 W·m. -2 . Figure 8 This is a schematic diagram illustrating the change in the liquid phase of molten salt over heating time under different heating power distributions, as provided in an embodiment of this disclosure. Figure 9 This is a schematic diagram illustrating the change of molten salt temperature difference with heating time under different heating power distributions provided in the embodiments of this disclosure. Figures 8 to 9 The results show the changes in the molten salt phase ratio and the molten salt temperature difference with heating time under different heating power distributions.

[0110] from Figure 8 It can be seen that when the heat flux density of the intermediate electric heating rod reaches 10000 W·m -2 Afterwards, all the molten salt melted completely within 23 minutes, nearly 8% faster than other conditions. However, it should be noted that excessively high heat flux density can also lead to locally higher temperatures in the liquid molten salt. In the early to mid-stages of heating (0-11 minutes), the temperature difference of the molten salt reached 79.7 K, exceeding the result of an average heat flux density distribution by approximately 18.1%. In the later stages of heating, since most of the molten salt had already turned into a liquid state, the temperature difference became less significant. It can also be seen that the heat flux density of the central heating rod has a greater impact than that of the side heating rods. Increasing the heat flux density of the central heating rod can shorten the melting time of the molten salt, while increasing the heat flux density of the side heating rods has no significant difference.

[0111] Furthermore, the effect of the arrangement of the electric heating tape on the molten salt heating process was investigated. Keeping the total heat flux density within the cavity constant, the heat flux density of the intermediate electric heating rod was increased from 8000 W·m⁻². -2 They were changed to 6500, 7000 and 7500 W·m respectively. -2 The heat flux densities of the electric heating tape under the three operating conditions, converted based on the surface area of ​​the electric heating rod and the area of ​​the square cavity sidewall, are 2827.44, 1884.96, and 942.48 W·m, respectively. -2 . Figure 10 This is a schematic diagram showing the arrangement of the electric heating cable according to an embodiment of the present disclosure. The present disclosure provides the arrangement method and specific dimensions of the electric heating cable as follows: Figure 10 As shown, numerical simulations were performed on two methods: placing the electric heating tape on the upper part and the lower part of the side wall of the cavity, to determine whether placing the electric heating tape on the upper part or the lower part of the side wall is more effective.

[0112] Figure 11 This is a schematic diagram illustrating the change in the liquid phase of molten salt over heating time when a side-upper arrangement of the heat tracing tape is provided in an embodiment of this disclosure. Figure 12This is a schematic diagram illustrating the change of molten salt temperature difference with heating time when a heat tracing cable is arranged on the upper side, as provided in an embodiment of this disclosure. Figure 13 This is a schematic diagram showing the change in the liquid phase of molten salt with heating time when the heat tracing tape is arranged on the lower side as provided in an embodiment of this disclosure. Figures 11 to 13 The trends of the liquid phase ratio of molten salt in the cavity and the temperature difference of molten salt with heating time are given when electric heating tape is installed on the upper side and the lower side, respectively. It can be seen that when electric heating tape is installed on the upper side, the higher the heating power, the faster the molten salt melts completely, and the lower the temperature difference of molten salt at each time stage.

[0113] from Figure 11 It can be seen that in the early to mid-stage of heating, i.e., before 15 minutes, the liquid salt concentration in the cavity was actually lower when the electric heating tape was installed than when it was not. This is because before 15 minutes, the liquid molten salt near the electric heating rod and the liquid molten salt near the electric heating tape were not yet connected. It was as if two sets of lower-temperature electric heating rods were heating and melting the nearby solid molten salt separately. This resulted in an overall lower liquid salt concentration than when the electric heating tape was not installed. However, in the mid to late-stage of heating, i.e. after 15 minutes, the connection and convergence of the two parts of liquid molten salt resulted in a wider contact area between the liquid molten salt and the remaining solid molten salt. The heat exchange was more thorough than when the electric heating tape was not installed. This resulted in a higher liquid salt concentration in the cavity when the electric heating tape was installed in the mid to late-stage of heating.

[0114] When the heat flux density of the upper side electric tracing tape is 2827.44 and 1884.96 W·m -2 At that time, the melting rate of molten salt was advanced by about 8%, and the maximum reduction in molten salt temperature difference was about 60.0% and 26.1%, respectively. Meanwhile, the heat flux density of the upper side electric tracing tape was relatively low at 942.48 W·m⁻². -2 When the molten salt melting time is not significantly changed, the molten salt temperature difference is reduced by a maximum of about 10.9%. However, when the electric heating tape is installed on the lower side, the only result is a reduction in the molten salt temperature difference. The heating power can be reduced by about 26.5%, 18.9%, and 6.7% from high to low, respectively, while the molten salt melting time remains unchanged.

[0115] The results here demonstrate that placing electric heating tape on the upper side and setting the heating power of the electric heating tape at different times can accelerate the melting speed of molten salt and reduce the unevenness of molten salt temperature distribution.

[0116] This disclosure provides a molten salt electronic device that can execute the processing flow provided in the embodiment of the molten salt heating control method. The molten salt electronic device includes: a memory, a processor, a computer program, and a communication interface; wherein the computer program is stored in the memory and configured to be executed by the processor as described above in the molten salt heating control method.

[0117] In addition, this disclosure also provides a computer-readable storage medium having a computer program stored thereon, the computer program being executed by a processor to implement the molten salt heating control method described in the above embodiments.

[0118] Furthermore, this disclosure also provides a computer program product, which includes a computer program or instructions that, when executed by a processor, implement the molten salt heating control method as described above.

[0119] It should be noted that the computer-readable medium described in this disclosure can be a computer-readable signal medium or a computer-readable storage medium, or any combination thereof. A computer-readable storage medium can be, for example,—but not limited to—an electrical, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or any combination thereof. More specific examples of a computer-readable storage medium may include, but are not limited to: an electrical connection having one or more wires, a portable computer disk, a hard disk, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), optical fiber, portable compact disk read-only memory (CD-ROM), optical storage device, magnetic storage device, or any suitable combination thereof. In this disclosure, a computer-readable storage medium can be any tangible medium containing or storing a program that can be used by or in connection with an instruction execution system, apparatus, or device. In this disclosure, a computer-readable signal medium can include a data signal propagated in baseband or as part of a carrier wave, carrying computer-readable program code. Such propagated data signals can take various forms, including but not limited to electromagnetic signals, optical signals, or any suitable combination thereof. A computer-readable signal medium can be any computer-readable medium other than a computer-readable storage medium, which can send, propagate, or transmit a program for use by or in connection with an instruction execution system, apparatus, or device. The program code contained on the computer-readable medium can be transmitted using any suitable medium, including but not limited to: wires, optical fibers, RF (radio frequency), etc., or any suitable combination thereof.

[0120] In some implementations, clients and servers can communicate using any currently known or future-developed network protocol, such as HTTP (Hypertext Transfer Protocol), and can interconnect with digital data communication (e.g., communication networks) of any form or medium. Examples of communication networks include local area networks (“LANs”), wide area networks (“WANs”), the Internet (e.g., the Internet of Things), and peer-to-peer networks (e.g., ad hoc peer-to-peer networks), as well as any currently known or future-developed networks.

[0121] The aforementioned computer-readable medium may be included in the aforementioned electronic device; or it may exist independently and not assembled into the electronic device.

[0122] The aforementioned computer-readable medium carries one or more programs that, when executed by the electronic device, cause the electronic device to:

[0123] The temperature of the outer wall surface of the molten salt storage tank at a preset location is monitored using armored thermocouples.

[0124] Calculate the temperature distribution data of the inner wall of the molten salt storage tank based on the outer wall temperature at a preset location of the molten salt storage tank.

[0125] Based on the temperature distribution data of the inner wall surface of the molten salt storage tank, determine the temperature distribution of the molten salt inside the tank.

[0126] The heating power of the electric heater and the electric heating tape is adjusted according to the temperature distribution of the molten salt.

[0127] In addition, the electronic device can also perform other steps in the molten salt heating control method described above.

[0128] Computer program code for performing the operations of this disclosure can be written in one or more programming languages ​​or a combination thereof, including but not limited to object-oriented programming languages ​​such as Java, Smalltalk, and C++, as well as conventional procedural programming languages ​​such as the "C" language or similar programming languages. The program code can be executed entirely on the user's computer, partially on the user's computer, as a standalone software package, partially on the user's computer and partially on a remote computer, or entirely on a remote computer or server. In cases involving remote computers, the remote computer can be connected to the user's computer via any type of network—including a local area network (LAN) or a wide area network (WAN)—or can be connected to an external computer (e.g., via the Internet using an Internet service provider).

[0129] The flowcharts and block diagrams in the accompanying drawings illustrate the architecture, functionality, and operation of possible implementations of systems, methods, and computer program products according to various embodiments of this disclosure. In this regard, each block in a flowchart or block diagram may represent a module, segment, or portion of code containing one or more executable instructions for implementing a specified logical function. It should also be noted that in some alternative implementations, the functions indicated in the blocks may occur in a different order than those indicated in the drawings. For example, two consecutively indicated blocks may actually be executed substantially in parallel, and they may sometimes be executed in reverse order, depending on the functions involved. It should also be noted that each block in the block diagrams and / or flowcharts, and combinations of blocks in the block diagrams and / or flowcharts, can be implemented using a dedicated hardware-based system that performs the specified function or operation, or using a combination of dedicated hardware and computer instructions.

[0130] The units described in the embodiments of this disclosure can be implemented in software or hardware. The names of the units are not, in some cases, intended to limit the specific unit.

[0131] The functions described above in this document can be performed, at least in part, by one or more hardware logic components. For example, exemplary types of hardware logic components that can be used, without limitation, include: Field Programmable Gate Arrays (FPGAs), Application-Specific Integrated Circuits (ASICs), Application Standard Products (ASSPs), System-on-Chip (SoCs), Complex Programmable Logic Devices (CPLDs), and so on.

[0132] In the context of this disclosure, a machine-readable medium can be a tangible medium that may contain or store a program for use by or in conjunction with an instruction execution system, apparatus, or device. A machine-readable medium can be a machine-readable signal medium or a machine-readable storage medium. A machine-readable medium can be, but is not limited to, electronic, magnetic, optical, electromagnetic, infrared, or semiconductor systems, apparatus, or devices, or any suitable combination of the foregoing. More specific examples of machine-readable storage media include electrical connections based on one or more wires, portable computer disks, hard disks, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), optical fiber, portable compact disk read-only memory (CD-ROM), optical storage devices, magnetic storage devices, or any suitable combination of the foregoing.

[0133] It should be noted that, in this document, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0134] The above description is merely a specific embodiment of this disclosure, enabling those skilled in the art to understand or implement it. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of this disclosure. Therefore, this disclosure is not to be limited to the embodiments described herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A method for controlling the heating of molten salt, characterized in that, The method includes: The temperature of the outer wall surface of the molten salt storage tank at a preset location is monitored using armored thermocouples. Calculate the temperature distribution data of the inner wall of the molten salt storage tank based on the outer wall temperature at a preset location of the molten salt storage tank. Based on the temperature distribution data of the inner wall surface of the molten salt storage tank, determine the temperature distribution of the molten salt inside the tank. The heating power of the electric heater and the electric heating tape is adjusted according to the temperature distribution of the molten salt.

2. The method according to claim 1, characterized in that, The armored thermocouple is installed at a predetermined position on the molten salt storage tank, including the top, upper side, and lower side; the temperature probe of the armored thermocouple is fixed to the outer wall of the molten salt storage tank for measuring the temperature of the outer wall.

3. The method according to claim 1, characterized in that, The electric heater is located inside the molten salt storage tank at the lower position. The electric heater includes multiple electric heating rods arranged in a horizontal row.

4. The method according to claim 1, characterized in that, The electric heating cable is wrapped around the upper part of the outer surface of the molten salt storage tank and closely adheres to the outer wall of the molten salt storage tank.

5. The method according to claim 1, characterized in that, The adjustment of the heating power of the electric heater and the electric heating tape according to the temperature distribution of the molten salt includes: Based on the results of numerical simulation analysis, a power allocation table is generated; Select a power allocation method from the power allocation table that matches the temperature distribution of the molten salt; Adjust the heating power of each electric heating rod and electric heating tape in the electric heater according to the power distribution method.

6. The method according to claim 5, characterized in that, The step of adjusting the heating power of each electric heating rod and electric heating tape in the electric heater according to the power distribution method includes: According to the power distribution method, the start-up and shutdown of each electric heating rod and the heating power in the electric heater are controlled to improve the uniformity of molten salt temperature distribution. According to the power distribution method, the power of the electric heating tape is adjusted to reduce the temperature difference between the upper and lower molten salt in the molten salt storage tank.

7. The method according to claim 1, characterized in that, The step of calculating the temperature distribution data of the inner wall of the molten salt storage tank based on the outer wall temperature at a preset location includes: Based on the heat conduction equation, and combined with the outer wall temperature at the preset location and the material parameters of the molten salt tank, the inner wall temperature distribution data of the molten salt tank is calculated by using the finite difference method.

8. The method according to claim 1, characterized in that, The method further includes: By using electric heaters and electric heating tapes in synergy, the number of electric heating rods inside molten salt storage tanks and pipelines can be reduced while keeping the total heating power constant, thereby reducing the flow resistance of molten salt. When the temperature of the molten salt drops to near its melting point, the electric heater and electric heating tape are quickly activated to heat it and prevent the molten salt from solidifying and forming a freeze blockage.

9. A molten salt heating device, characterized in that, The device includes a molten salt storage tank, an electric heater, an electric heating tape, a sheathed thermocouple, a temperature signal processor, a heating power distribution program, a heating device controller, and signal lines; The molten salt storage tank is a container for storing solid and liquid molten salt; The electric heater is located inside the molten salt storage tank at the lower position. The electric heater includes multiple electric heating rods arranged in a horizontal row. The electric heating tape is wrapped around the upper part of the outer surface of the molten salt storage tank and is in close contact with the outer wall of the molten salt storage tank. The armored thermocouple is installed at a predetermined position on the molten salt storage tank, including the top, upper side, and lower side; the temperature probe of the armored thermocouple is fixed to the outer wall of the molten salt storage tank for measuring the temperature of the outer wall.

10. The apparatus according to claim 9, characterized in that, The temperature signal processor is used to acquire the outer wall temperature of the molten salt storage tank at a preset position monitored by the armored thermocouple through the signal line, and convert the outer wall temperature into a digital signal. The heating power distribution program is used to receive the digital signal converted by the temperature signal processor to obtain the outer wall temperature of the molten salt storage tank at a preset position; calculate the inner wall temperature distribution data of the molten salt storage tank based on the outer wall temperature at the preset position; determine the temperature distribution of the molten salt inside the molten salt storage tank based on the inner wall temperature distribution data; adjust the heating power of the electric heater and the electric heating tape based on the temperature distribution of the molten salt, and generate the processing result. The heating device controller is used to receive the processing results generated by the heating power allocation program, and control the heating power of the electric heater and the electric heating tape according to the processing results.

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