A thermal storage medium electric heating device

Abstract

The utility model provides a kind of heat storage medium electric heating device, including shell, input port for flowing into low temperature heat storage medium and output port for flowing out high temperature heat storage medium are provided on shell, input port and output port are located at the both ends of shell respectively;Multiple electric heating tube bundles and multiple baffles are arranged in shell, multiple baffles are sequentially spaced apart along the direction of input port to output port, multiple baffles are sequentially rotated along the same rotation axis, and multiple baffles are all heterotropic baffle, or, part is heterotropic baffle, another part is homotropic baffle, so that multiple baffles are sequentially arranged structure, to realize that heat storage medium generates quasi-spiral flow in shell interior.The scheme can promote the forced convection circulation of high temperature heat storage medium and low temperature heat storage medium, optimize the temperature distribution of heat storage medium in heating device, to solve the problems of uneven temperature, local overheating or insufficient heating etc. in the heating process of traditional heat storage medium electric heater.

Description

Technical Field

[0001] This utility model relates to the field of heat storage medium heating technology, specifically to an electric heating device for heat storage medium. Background Technology

[0002] Thermal storage media in high-temperature heat transfer scenarios such as solar thermal power generation and industrial waste heat utilization typically have the characteristics of high temperature, high heat capacity, and low vapor pressure. Taking molten salt as an example, molten salt is widely used in the field of high-temperature heat transfer and thermal storage due to its high operating temperature, high heat capacity, and low vapor pressure.

[0003] Shell-and-tube electric heaters are the core equipment for heating the heat storage medium (usually molten salt), and enhancing heat transfer in the shell side is a key technology. In existing technologies, baffle structures are usually used to guide the flow of the heat storage medium (usually molten salt) to improve heat transfer efficiency. To enhance the heat transfer of the shell-side heat storage medium (usually molten salt), baffles are usually installed inside the heater. The main functions of the baffles are: (1) to support the heating tube bundle and prevent vibration; (2) to change the flow direction of the heat storage medium (usually molten salt), forcing the heat storage medium (usually molten salt) to flow across the heating tube bundle multiple times laterally or longitudinally during the flow process, increasing fluid turbulence and improving the convective heat transfer coefficient. The most common type of baffle is the arc-shaped baffle, which is usually a flat plate with a partial circular notch.

[0004] Traditional parallel bow-shaped baffles form a "Z"-shaped flow channel through alternating arrangements, but this results in a large flow dead zone, leading to insufficient contact between the heat storage medium (usually molten salt) and the heating tube bundle, resulting in a low convective heat transfer coefficient. To address this issue, invention patent CN117704634A discloses a high-efficiency annular spiral flow channel molten salt electric heater, which uses spiral baffles to form a continuous spiral flow channel. While this eliminates the dead zone, it has significant drawbacks: the spiral baffles require customized processing, making manufacturing difficult; the assembly precision requirements with the central cylinder are high, resulting in high installation costs; disassembly and replacement during later maintenance are difficult, leading to poor overall economic efficiency and hindering large-scale application.

[0005] Existing technologies have not yet resolved the contradiction between "efficient heat transfer" and "low-cost implementation." At the same time, they lack structural designs to improve the temperature uniformity of the heat storage medium (usually molten salt), resulting in a large internal temperature gradient during equipment operation, which easily generates thermal stress and affects lifespan. Furthermore, during the cold start phase, a large amount of low-temperature heat storage medium (usually molten salt) needs to be heated as a whole, resulting in excessively long start-up time. Utility Model Content

[0006] To address the shortcomings of existing technologies, the purpose of this invention is to provide an electric heating device for thermal storage media that can promote forced convection circulation between high-temperature and low-temperature thermal storage media, optimize the temperature distribution of the thermal storage media within the heating device, and solve problems such as uneven temperature, local overheating, or insufficient heating that exist in traditional electric heaters for thermal storage media during the heating process.

[0007] This utility model provides an electric heating device for a thermal storage medium, comprising a housing, wherein the housing is provided with an inlet for a low-temperature thermal storage medium to flow in and an outlet for a high-temperature thermal storage medium to flow out, the inlet and the outlet being located at opposite ends of the housing; the housing is provided with multiple sets of electric heating tube bundles and multiple baffles, the multiple baffles being arranged sequentially at intervals along the direction from the inlet to the outlet, the multiple baffles being arranged to rotate sequentially along the same rotation axis, and the multiple baffles being anti-directional baffles, or, a portion being anti-directional baffles and another portion being co-directional baffles, so that the multiple baffles are arranged in a sequential structure to achieve a quasi-spiral flow of the thermal storage medium inside the housing; When all of the baffles are opposite baffles, the two baffles adjacent to any one of the baffles exhibit different rotation angles; In the case where some of the multiple baffles are opposite-direction baffles and others are same-direction baffles, the two baffles adjacent to any one of the opposite-direction baffles exhibit different rotation angles, while the two baffles adjacent to any one of the same-direction baffles exhibit the same rotation angle.

[0008] Furthermore, the rotation axis is the central axis of the shell; the plane where the baffle is located is parallel to the longitudinal section of the shell; the area of ​​the baffle is greater than half the area of ​​the inner diameter circle of the shell, and there is one and only one space between the baffle and the shell to allow the flow of the heat storage medium, and this flow space has a small semi-circular structure; the number of baffles is 2+3n; where n is a positive integer.

[0009] Furthermore, the multiple baffles are sequentially divided into n+1 groups along the direction from the input port to the output port. The number of baffles in the first n groups is three, and the number of baffles in the last group is two. The three baffles in each of the first n groups correspond to each other, and the corresponding baffles exhibit the same rotation angle.

[0010] Furthermore, when all the baffles are opposite-direction baffles, the rotation angle of the latter baffle in the first and second baffle groups in the first n groups relative to the former baffle is a preset angle θ. The distribution pattern of the odd-numbered baffle groups in the first n groups is the same, and the distribution pattern of the even-numbered baffle groups in the first n groups is the same. The first baffle in the last baffle group rotates by the preset angle θ along the central axis relative to the third baffle in the previous baffle group, and the second baffle in the last baffle group rotates by the preset angle θ along the central axis relative to the first baffle.

[0011] Furthermore, in the case where a portion of the multiple baffles are opposite-direction baffles and another portion are same-direction baffles, the second baffle in any of the first n groups of baffles is rotated by a preset angle θ relative to the first baffle along the central axis, and the third baffle is rotated 180° relative to the second baffle along the central axis. The three baffles in any one of the first n groups and the three baffles in the adjacent baffle group that is also one of the first n groups correspond to each other in sequence, and the rotation angles of the two corresponding baffles differ by 180°. The first baffle in the last set of baffle groups is rotated 180° relative to the first baffle in the previous set of baffle groups, and the second baffle in the last set of baffle groups is rotated 180° relative to the first baffle in the central axis.

[0012] Furthermore, the preset angle θ ranges from 115° to 155°.

[0013] This utility model also provides another electric heating device for heat storage medium, including any of the above-mentioned electric heating devices for heat storage medium, and the end of the housing with the output port is also provided with a return port. The return port is connected to the input port through a return pipe, so that part of the high-temperature heat storage medium flows back to the input port and mixes with the low-temperature heat storage medium input through the input port, thereby increasing the temperature of the heat storage medium entering the heating device.

[0014] Furthermore, a circulation pump is also installed at the reflux port.

[0015] Furthermore, the return pipe is also equipped with a regulating valve and a check valve, with the regulating valve located at one end near the return port and the check valve located at one end near the input port.

[0016] Furthermore, a temperature sensor is also provided at one end of the housing where the output port is located.

[0017] Compared with the prior art, the present invention has the following beneficial effects: 1. Sequential Baffle Arrangement Structure: Addressing the conflict between enhanced heat transfer and cost in existing technologies, this invention aims to provide a low-cost, easily implemented enhanced heat transfer structure. By employing a sequential arrangement of baffles with specific rotation angles, quasi-helical flow is induced in the heat storage medium, significantly reducing dead zones, enhancing turbulence and mixing, and improving the convective heat transfer coefficient. This achieves the enhanced heat transfer effect of a helical baffle at a low manufacturing cost, thereby improving the overall thermal efficiency of the heating device.

[0018] 2. Forced Circulation Pump: To address the shortcomings of insufficient temperature control accuracy and response speed in existing technologies, this invention adds an external high-temperature heat storage medium recirculation loop. By controlling the flow rate of the circulation pump, the amount of high-temperature heat storage medium returning to the inlet can be quickly and actively adjusted. The mixing of the returning high-temperature heat storage medium with the low-temperature heat storage medium at the inlet directly affects the inlet temperature. At the same time, it also provides a rapid and precise auxiliary control method for the outlet temperature, significantly improving temperature control accuracy and dynamic response capability.

[0019] 3. External Circulation Loop: Addressing the issues of slow start-up and high energy consumption in existing technologies, this invention utilizes a recirculation loop to return a portion of the high-temperature heat storage medium to the inlet, effectively increasing the initial temperature of the heat storage medium entering the heating device. This allows the outlet temperature to reach the set value more quickly, shortening the equipment start-up and preheating time. During steady-state operation, the increased inlet temperature reduces the temperature rise load that the heating device needs to bear, thereby reducing the average operating power of the electric heating element and achieving energy savings.

[0020] 4. Combination of internal enhanced heat transfer and external forced circulation heat transfer: In response to the problem of uneven internal temperature distribution in existing technologies, the internal mixing promoted by the rotating arrangement of baffles in this invention, along with the forced convection and mixing effect brought about by external recirculation, jointly promote the uniformity of the temperature of the heat storage medium inside the heating device, effectively avoiding the problems of local overheating or underheating, and significantly reducing the temperature gradient along the heating device, which is conducive to reducing thermal stress and extending the equipment life. Attached Figure Description

[0021] Other features, objects, and advantages of this invention will become more apparent from the following detailed description of non-limiting embodiments with reference to the accompanying drawings: Figure 1 A schematic diagram of the structure of an electric heating device for a heat storage medium provided in an embodiment of this utility model; Figure 2 A schematic diagram of the baffle arrangement angle of an electric heating device for a heat storage medium provided in an embodiment of this utility model; Figure 3 A schematic diagram of another heat storage medium electric heating device provided in this embodiment of the utility model; Figure 4 A schematic diagram of the baffle plate arrangement angle of another heat storage medium electric heating device provided in this embodiment of the utility model; Figure 5 A cross-sectional schematic diagram of another heat storage medium electric heating device provided in an embodiment of this utility model.

[0022] In the picture: 1. Housing; 2. Baffle plate; 3. Electric heating tube bundle; 4. Output port; 5. Temperature sensor; 6. Circulation pump; 7. Regulating valve; 8. Return pipe; 9. Check valve; 10. Input port; 11. Return port. Detailed Implementation

[0023] The present invention will now be described in detail with reference to specific embodiments. These embodiments will help those skilled in the art to further understand the present invention, but do not limit the present invention in any way. It should be noted that those skilled in the art can make several changes and improvements without departing from the concept of the present invention. These all fall within the protection scope of the present invention.

[0024] First embodiment: Please see Figure 1 This embodiment provides an electric heating device for heat storage medium, including a shell 1, which has a double-layer shell structure; The shell 1 is provided with an inlet 10 for the inflow of low-temperature heat storage medium and an outlet 4 for the outflow of high-temperature heat storage medium. The inlet 10 and the outlet 4 are located at the two ends of the shell 1, respectively. The shell 1 is equipped with multiple sets of electric heating tube bundles 3 and multiple baffles 2. The multiple sets of electric heating tube bundles 3 pass through the multiple baffles 2 respectively. The multiple baffles 2 are arranged sequentially at intervals along the direction from the inlet 10 to the outlet 4. The multiple baffles 2 are arranged to rotate sequentially along the same rotation axis. The multiple baffles 2 are all anti-directional baffles. The two baffles 2 adjacent to any baffle 2 present different rotation angles, so that the multiple baffles 2 are arranged in a sequential arrangement to realize the quasi-spiral flow of the heat storage medium inside the shell 1. Unlike the prior art, these baffles 2 are not simply arranged at 180° intervals. Instead, through this sequential arrangement of baffles 2 with rotation angles, the heat storage medium is forced to flow in the circumferential (tangential) direction while flowing in the axial direction in order to pass through the channel between adjacent baffles 2, thereby forming an approximately spiral flow path in the shell space. This flow pattern greatly enhances the turbulence and radial mixing of the heat storage medium, effectively scouring the tube bundle surface and shell wall. Compared with the traditional arrangement of baffles 2, it significantly reduces the flow dead zone and improves the convective heat transfer coefficient between the heat storage medium and the electric heating tube bundle 3, achieving the goal of significantly improving heat transfer efficiency without using complex and expensive spiral baffles. Temperature sensors 5 are installed at both the end of the housing 1 with the inlet port 10 and the end with the outlet port 4; the inlet temperature and outlet temperature (or other key temperatures) are detected by the temperature sensors 5; the input and output of the heat storage medium are adjusted according to the deviation between the detected temperature and the set temperature. The electric heating tube bundle 3 and the temperature sensor 5 are electrically connected to the control system, and the control system also controls the flow rate of the heat storage medium at the input port 10 and the output port 4; the control system is electrically connected to the external power supply equipment.

[0025] Among them, the heat storage medium is a fluid medium that can absorb the heat generated by the electric heating tube bundle 3. It can be selected from any one of molten salt, binary molten salt, ternary molten salt, heat transfer oil, supercritical carbon dioxide, liquid metal, and alumina particles according to different application environments and scenarios. The design of the baffle 2 can be refined according to different needs, and any one of the following is preferred: single bow-shaped baffle, perforated baffle, rectangular baffle, or perforated baffle.

[0026] In one specific embodiment, the area of ​​the baffle plate 2 is greater than half the inner diameter circle area of ​​the shell 1, and there is one and only one space between the baffle plate 2 and the shell 1 to realize the flow of the heat storage medium, and the flow space has a small semi-circular structure. The number of baffles 2 can be designed differently depending on the different heat storage media, but the number must satisfy 2+3n (n=1, 2, 3, ...); preferably, the number of baffles 2 can be 5 to 14, which satisfy 2+3n. Multiple baffles 2 rotate along the central axis of the housing 1. The plane of the baffles 2 is parallel to the longitudinal section of the housing 1. The multiple baffles 2 are divided into n+1 groups along the direction from the input port 10 to the output port 4. The number of baffles 2 in the first n groups is three, and the number of baffles 2 in the last group is two. The three baffles 2 in each of the first n groups correspond to each other, and the corresponding baffles 2 have the same rotation angle.

[0027] In an optional embodiment, the rotation angle of the latter baffle 2 in the first and second baffle groups of the first n groups relative to the former baffle 2 can be a preset angle θ. The distribution pattern of the odd-numbered baffle groups in the first n groups is the same, and the distribution pattern of the even-numbered baffle groups in the first n groups is the same. The first baffle 2 in the last baffle group rotates along the central axis by a preset angle θ relative to the third baffle 2 in the previous baffle group, and the second baffle 2 in the last baffle group rotates along the central axis by a preset angle θ relative to the first baffle 2. The preset angle θ ranges from 115° to 155°.

[0028] The core innovation of this embodiment lies in providing an integrated electric heater device for thermal storage medium that can efficiently transfer heat. Through specific structural design and system integration, it significantly improves heating performance, efficiency and controllability.

[0029] Its key points / innovations are: Unique baffle arrangement design: Features: Multiple baffles 2 are arranged sequentially (in sequence) along the flow direction of the heat storage medium, and there is a specific relative rotation angle between adjacent baffles.

[0030] Core effect: By using non-spiral baffles 2 (such as low-cost bow-shaped baffles) to achieve the effect of spiral baffles, this specific spatial arrangement induces the heat storage medium to generate a significant circumferential (rotational) flow component while flowing axially, forming a quasi-spiral flow path, thereby effectively reducing flow dead zones and enhancing heat transfer.

[0031] Advantages: It achieves enhanced heat transfer effects close to those of expensive spiral baffles, but with significantly reduced manufacturing costs and complexity.

[0032] Second embodiment: Please see Figures 1-2 This embodiment provides an electric heating device for heat storage medium, including a shell 1, which has a double-layer shell structure; The shell 1 is provided with an inlet 10 for the inflow of low-temperature heat storage medium and an outlet 4 for the outflow of high-temperature heat storage medium. The inlet 10 and the outlet 4 are located at the two ends of the shell 1, respectively. The housing 1 contains multiple sets of electric heating tube bundles 3 and multiple baffles 2, with the electric heating tube bundles 3 passing through the baffles 2 respectively. The baffles 2 are arranged sequentially at intervals along the direction from the inlet 10 to the outlet 4, and are arranged to rotate sequentially along the same rotation axis. A portion of the baffles 2 are opposite-direction baffles, and another portion are same-direction baffles. The rotation angles of two baffles 2 adjacent to any opposite-direction baffle are different, and the rotation angles of two baffles 2 adjacent to any same-direction baffle are different. The rotation angles of the baffles 2 are the same, so that multiple baffles 2 are arranged in a sequential manner to achieve quasi-spiral flow of the thermal storage medium inside the shell 1. Unlike existing technologies, these baffles 2 are not simply arranged at 180° intervals, but through this sequential arrangement of baffles 2 with rotation angles, the thermal storage medium is forced to flow circumferentially (tangentially) while flowing axially to pass through the channels between adjacent baffles 2, thus forming an approximately spiral flow path in the shell-side space. This flow pattern greatly enhances the turbulence and radial mixing of the thermal storage medium, effectively scouring the tube bundle surface and shell wall. Compared with the traditional arrangement of baffles 2, it significantly reduces the flow dead zone and improves the convective heat transfer coefficient between the thermal storage medium and the electrically heated tube bundle 3, achieving the goal of significantly improving heat transfer efficiency without using complex and expensive spiral baffles. Temperature sensors 5 are installed at both the end of the housing 1 with the inlet port 10 and the end with the outlet port 4; the inlet temperature and outlet temperature (or other key temperatures) are detected by the temperature sensors 5; the input and output of the heat storage medium are adjusted according to the deviation between the detected temperature and the set temperature. The electric heating tube bundle 3 and the temperature sensor 5 are electrically connected to the control system, and the control system also controls the flow rate of the heat storage medium at the input port 10 and the output port 4; the control system is electrically connected to the external power supply equipment.

[0033] Among them, the heat storage medium is a fluid medium that can absorb the heat generated by the electric heating tube bundle 3. It can be selected from any one of molten salt, binary molten salt, ternary molten salt, heat transfer oil, supercritical carbon dioxide, liquid metal, and alumina particles according to different application environments and scenarios. The design of the baffle 2 can be refined according to different needs, and any one of the following is preferred: single bow-shaped baffle, perforated baffle, rectangular baffle, or perforated baffle.

[0034] In one specific embodiment, the area of ​​the baffle plate 2 is greater than half the inner diameter circle area of ​​the shell 1, and there is one and only one space between the baffle plate 2 and the shell 1 to realize the flow of the heat storage medium, and the flow space has a small semi-circular structure. The number of baffles 2 can be designed differently depending on the different heat storage media, but the number must satisfy 2+3n (n=1, 2, 3, ...); preferably, the number of baffles 2 can be 5 to 14, which satisfy 2+3n. Multiple baffles 2 rotate along the central axis of the housing 1. The plane of the baffles 2 is parallel to the longitudinal section of the housing 1. The multiple baffles 2 are divided into n+1 groups along the direction from the input port 10 to the output port 4. The number of baffles 2 in the first n groups is three, and the number of baffles 2 in the last group is two. The three baffles 2 in each of the first n groups correspond to each other, and the corresponding baffles 2 have the same rotation angle.

[0035] In an optional embodiment, the second baffle 2 in any of the first n groups of baffle groups is rotated by a preset angle θ relative to the first baffle 2 along the central axis, and the third baffle 2 is rotated 180° relative to the second baffle 2 along the central axis. The three baffles 2 in any one of the first n groups of baffles and the three baffles 2 in the adjacent baffle group which is also one of the first n groups are corresponding to each other, and the rotation angles of the corresponding two baffles 2 are all 180° apart. The first baffle 2 in the last baffle group is rotated 180° along the central axis relative to the first baffle 2 in the previous baffle group, and the second baffle 2 in the last baffle group is rotated 180° along the central axis relative to the first baffle 2. The preset angle θ ranges from 115° to 155°.

[0036] In a practical application scenario, the baffles 2 of the electric heating device for the heat storage medium are arranged as follows: Figure 2 As shown, in the first group, baffle ② is rotated by an angle θ (115°~155°, preferably 135°) relative to the baffle ① in front of it, and baffle ③ is also rotated by an angle 180° relative to baffle ②; in the second group, baffle ④ is rotated by 180° relative to baffle ① in the first group, baffle ⑤ is rotated by an angle θ (115°~155°, preferably 135°) relative to baffle ④, and so on, while the last baffle ⑧ is rotated by 180° relative to baffle ⑦, thereby realizing the quasi-spiral flow of the heat storage medium.

[0037] The core innovation of this embodiment lies in providing an integrated electric heater device for thermal storage medium that can efficiently transfer heat. Through specific structural design and system integration, it significantly improves heating performance, efficiency and controllability.

[0038] Its key points / innovations are: Unique baffle arrangement design: Features: Multiple baffles 2 are arranged sequentially (in sequence) along the flow direction of the heat storage medium, and there is a specific relative rotation angle between adjacent baffles.

[0039] Core effect: By using non-spiral baffles 2 (such as low-cost bow-shaped baffles) to achieve the effect of spiral baffles, this specific spatial arrangement induces the heat storage medium to generate a significant circumferential (rotational) flow component while flowing axially, forming a quasi-spiral flow path, thereby effectively reducing flow dead zones and enhancing heat transfer.

[0040] Advantages: It achieves enhanced heat transfer effects close to those of expensive spiral baffles, but with significantly reduced manufacturing costs and complexity.

[0041] Third embodiment: Please see Figure 3 and Figure 5 This embodiment provides an electric heating device for heat storage medium, including a shell 1, which has a double-layer shell structure; The shell 1 is provided with an inlet 10 for the inflow of low-temperature heat storage medium and an outlet 4 for the outflow of high-temperature heat storage medium. The inlet 10 and the outlet 4 are located at the two ends of the shell 1, respectively. The shell 1 is equipped with multiple sets of electric heating tube bundles 3 and multiple baffles 2. The multiple sets of electric heating tube bundles 3 pass through the multiple baffles 2 respectively. The multiple baffles 2 are arranged sequentially at intervals along the direction from the inlet 10 to the outlet 4. The multiple baffles 2 are arranged to rotate sequentially along the same rotation axis. The multiple baffles 2 are all anti-directional baffles. The two baffles 2 adjacent to any baffle 2 present different rotation angles, so that the multiple baffles 2 are arranged in a sequential arrangement to realize the quasi-spiral flow of the heat storage medium inside the shell 1. Unlike the prior art, these baffles 2 are not simply arranged at 180° intervals. Instead, through this sequential arrangement of baffles 2 with rotation angles, the heat storage medium is forced to flow in the circumferential (tangential) direction while flowing in the axial direction in order to pass through the channel between adjacent baffles 2, thereby forming an approximately spiral flow path in the shell space. This flow pattern greatly enhances the turbulence and radial mixing of the heat storage medium, effectively scouring the tube bundle surface and shell wall. Compared with the traditional arrangement of baffles 2, it significantly reduces the flow dead zone and improves the convective heat transfer coefficient between the heat storage medium and the electric heating tube bundle 3, achieving the goal of significantly improving heat transfer efficiency without using complex and expensive spiral baffles. The shell 1 has an output port 4 at one end and a return port 11 at the other end. The return port 11 is connected to the input port 10 through a return pipe 8 to form an external heat storage medium recirculation loop. This allows some of the high-temperature heat storage medium to flow back to the input port 10 and mix with the low-temperature heat storage medium input into the input port 10, thereby increasing the temperature of the heat storage medium entering the heating device. During the inlet preheating stage, some of the high-temperature heat storage medium is flowed back to the input port, directly increasing the temperature of the heat storage medium entering the heating device, T_in_mixed (mixed inlet temperature). This allows the target outlet temperature T_out to be reached more quickly during the start-up stage and reduces the net heat load required by the electric heating tube bundle 3 during steady-state operation, achieving energy-saving effects. A circulation pump 6 is also installed at the return port 11 or on the return pipe 8 to provide circulation power. The speed of the circulation pump 6 is adjusted by the control system, thereby controlling the recirculation flow rate Q_recirc, which can quickly and accurately change the inlet temperature T_in_mixed after mixing. This provides a faster fine-tuning means to adjust the final outlet temperature T_out, independent of the power adjustment of the heating element. Preferably, the circulation pump 6 is located at the return port 11 and can be a variable frequency speed control pump to accurately control the flow rate. The forced circulation of the circulation pump 6 helps to improve the overall fluidity of the heat storage medium in the system. Combined with the mixing effect of the internal rotating baffle 2, it further promotes temperature homogenization and reduces the temperature difference inside the heating device. A regulating valve 7 and a check valve 9 are also installed on the return pipe 8. The regulating valve 7 is located at the end near the return port 11, and the check valve 9 is located at the end near the inlet 10 to control the flow rate, pressure, and temperature of the returned heat storage medium, so as to achieve safe and efficient operation of the loop. Temperature sensors 5 are installed at both the end of the housing 1 with the inlet port 10 and the end with the outlet port 4. The inlet temperature and outlet temperature (or other key temperatures) are detected by the temperature sensors 5. Based on the deviation between the detected temperature and the set temperature, the input and output of the heat storage medium, as well as the operating status (such as speed, start / stop) or flow rate of the circulating pump 6 in the external recirculation loop, are adjusted to change the amount of high-temperature heat storage medium returning to the inlet, thereby assisting or leading the adjustment of the outlet temperature and realizing inlet preheating, thus shortening the start-up time or reducing steady-state power consumption. The electric heating tube bundle 3, temperature sensor 5, circulating pump 6, regulating valve 7 and check valve 9 are electrically connected to the control system, and the control system also controls the flow rate of the heat storage medium at the input port 10 and the output port 4; the control system is electrically connected to the external power supply equipment.

[0042] Among them, the heat storage medium is a fluid medium that can absorb the heat generated by the electric heating tube bundle 3. It can be selected from any one of molten salt, binary molten salt, ternary molten salt, heat transfer oil, supercritical carbon dioxide, liquid metal, and alumina particles according to different application environments and scenarios. The design of the baffle 2 can be refined according to different needs, preferably any one of the following: single bow-shaped baffle, perforated baffle, rectangular baffle, or perforated baffle; All pipes and equipment involved in the recirculation loop are well insulated to reduce heat loss and improve the efficiency of the thermal storage system.

[0043] In one specific embodiment, the area of ​​the baffle plate 2 is greater than half the inner diameter circle area of ​​the shell 1, and there is one and only one space between the baffle plate 2 and the shell 1 to realize the flow of the heat storage medium, and the flow space has a small semi-circular structure. The number of baffles 2 can be designed differently depending on the different heat storage media, but the number must satisfy 2+3n (n=1, 2, 3, ...); preferably, the number of baffles 2 can be 5 to 14, which satisfy 2+3n. Multiple baffles 2 rotate along the central axis of the housing 1. The plane of the baffles 2 is parallel to the longitudinal section of the housing 1. The multiple baffles 2 are divided into n+1 groups along the direction from the input port 10 to the output port 4. The number of baffles 2 in the first n groups is three, and the number of baffles 2 in the last group is two. The three baffles 2 in each of the first n groups correspond to each other, and the corresponding baffles 2 have the same rotation angle.

[0044] In an optional embodiment, the rotation angle of the latter baffle 2 in the first and second baffle groups of the first n groups relative to the former baffle 2 can be a preset angle θ. The distribution pattern of the odd-numbered baffle groups in the first n groups is the same, and the distribution pattern of the even-numbered baffle groups in the first n groups is the same. The first baffle 2 in the last baffle group rotates along the central axis by a preset angle θ relative to the third baffle 2 in the previous baffle group, and the second baffle 2 in the last baffle group rotates along the central axis by a preset angle θ relative to the first baffle 2. The preset angle θ ranges from 115° to 155°.

[0045] The core innovation of this embodiment lies in providing an integrated electric heater device for thermal storage medium that can efficiently transfer heat. Through specific structural design and system integration, it significantly improves heating performance, efficiency and controllability.

[0046] Its key points / innovations are: 1. Unique baffle plate arrangement design: Features: Multiple baffles 2 are arranged sequentially (in sequence) along the flow direction of the heat storage medium, and there is a specific relative rotation angle between adjacent baffles.

[0047] Core effect: By using non-spiral baffles 2 (such as low-cost bow-shaped baffles) to achieve the effect of spiral baffles, this specific spatial arrangement induces the heat storage medium to generate a significant circumferential (rotational) flow component while flowing axially, forming a quasi-spiral flow path, thereby effectively reducing flow dead zones and enhancing heat transfer.

[0048] Advantages: It achieves enhanced heat transfer effects close to those of expensive spiral baffles, but with significantly reduced manufacturing costs and complexity.

[0049] 2. Integrated external thermal storage medium recirculation system: Features: An external forced recirculation loop consisting of a circulating pump 6 and a return pipe 8 is added outside the heating device. This loop draws out a portion of the high-temperature heat storage medium near the output port 4 (high-temperature zone) of the heating device and transports it back to the vicinity of the input port 10 (low-temperature zone) of the heating device, where it mixes with the low-temperature heat storage medium entering the heating device to increase the inlet temperature of the heating device and the initial temperature of the heat storage medium entering the heating device.

[0050] Core functions: ① Inlet preheating: Increases the initial temperature of the heat storage medium entering the heating device. ② Precise temperature control: Achieves rapid and precise adjustment of the outlet temperature by regulating the flow rate (speed or valve opening) of the circulating pump 6. ③ Enhanced flow: Increases the overall driving force of the heat storage medium in the system, promotes internal flow, and reduces dead zones.

[0051] 3. Synergistic optimization effect between the internal baffle plate arrangement and the external recirculation system: Features: The above-mentioned rotating baffle 2 arrangement structure is combined with the external recirculation system, and the temperature sensor 5 is used for feedback to achieve synergistic optimization of heat transfer effect.

[0052] Core methods / effects: ① Start-up phase: Recirculation can be used to quickly increase the inlet temperature and shorten the preheating time. ② Steady-state phase: By combining the adjustment of heating element power and recirculation flow rate, efficient and stable outlet temperature control can be achieved, reducing energy consumption. ③ Dynamic response: Mainly by adjusting the recirculation flow rate to quickly respond to load or setpoint changes, improving control accuracy.

[0053] Fourth embodiment: Please see Figures 3-5 This embodiment provides an electric heating device for heat storage medium, including a shell 1, which has a double-layer shell structure; The shell 1 is provided with an inlet 10 for the inflow of low-temperature heat storage medium and an outlet 4 for the outflow of high-temperature heat storage medium. The inlet 10 and the outlet 4 are located at the two ends of the shell 1, respectively. The housing 1 contains multiple sets of electric heating tube bundles 3 and multiple baffles 2, with the electric heating tube bundles 3 passing through the baffles 2 respectively. The baffles 2 are arranged sequentially at intervals along the direction from the inlet 10 to the outlet 4, and are arranged to rotate sequentially along the same rotation axis. A portion of the baffles 2 are opposite-direction baffles, and another portion are same-direction baffles. The rotation angles of two baffles 2 adjacent to any opposite-direction baffle are different, and the rotation angles of two baffles 2 adjacent to any same-direction baffle are different. The rotation angles of the baffles 2 are the same, so that multiple baffles 2 are arranged in a sequential manner to achieve quasi-spiral flow of the thermal storage medium inside the shell 1. Unlike existing technologies, these baffles 2 are not simply arranged at 180° intervals, but through this sequential arrangement of baffles 2 with rotation angles, the thermal storage medium is forced to flow circumferentially (tangentially) while flowing axially to pass through the channels between adjacent baffles 2, thus forming an approximately spiral flow path in the shell-side space. This flow pattern greatly enhances the turbulence and radial mixing of the thermal storage medium, effectively scouring the tube bundle surface and shell wall. Compared with the traditional arrangement of baffles 2, it significantly reduces the flow dead zone and improves the convective heat transfer coefficient between the thermal storage medium and the electrically heated tube bundle 3, achieving the goal of significantly improving heat transfer efficiency without using complex and expensive spiral baffles. The shell 1 has an output port 4 at one end and a return port 11 at the other end. The return port 11 is connected to the input port 10 through a return pipe 8 to form an external heat storage medium recirculation loop. This allows some of the high-temperature heat storage medium to flow back to the input port 10 and mix with the low-temperature heat storage medium input into the input port 10, thereby increasing the temperature of the heat storage medium entering the heating device. During the inlet preheating stage, some of the high-temperature heat storage medium is flowed back to the input port, directly increasing the temperature of the heat storage medium entering the heating device, T_in_mixed (mixed inlet temperature). This allows the target outlet temperature T_out to be reached more quickly during the start-up stage and reduces the net heat load required by the electric heating tube bundle 3 during steady-state operation, achieving energy-saving effects. A circulation pump 6 is also installed at the return port 11 or on the return pipe 8 to provide circulation power. The speed of the circulation pump 6 is adjusted by the control system, thereby controlling the recirculation flow rate Q_recirc, which can quickly and accurately change the inlet temperature T_in_mixed after mixing. This provides a faster fine-tuning means to adjust the final outlet temperature T_out, independent of the power adjustment of the heating element. Preferably, the circulation pump 6 is located at the return port 11 and can be a variable frequency speed control pump to accurately control the flow rate. The forced circulation of the circulation pump 6 helps to improve the overall fluidity of the heat storage medium in the system. Combined with the mixing effect of the internal rotating baffle 2, it further promotes temperature homogenization and reduces the temperature difference inside the heating device. A regulating valve 7 and a check valve 9 are also installed on the return pipe 8. The regulating valve 7 is located at the end near the return port 11, and the check valve 9 is located at the end near the inlet 10 to control the flow rate, pressure, and temperature of the returned heat storage medium, so as to achieve safe and efficient operation of the loop. Temperature sensors 5 are installed at both the end of the housing 1 with the inlet port 10 and the end with the outlet port 4. The inlet temperature and outlet temperature (or other key temperatures) are detected by the temperature sensors 5. Based on the deviation between the detected temperature and the set temperature, the input and output of the heat storage medium, as well as the operating status (such as speed, start / stop) or flow rate of the circulating pump 6 in the external recirculation loop, are adjusted to change the amount of high-temperature heat storage medium returning to the inlet, thereby assisting or leading the adjustment of the outlet temperature and realizing inlet preheating, thus shortening the start-up time or reducing steady-state power consumption. The electric heating tube bundle 3, temperature sensor 5, circulating pump 6, regulating valve 7 and check valve 9 are electrically connected to the control system, and the control system also controls the flow rate of the heat storage medium at the input port 10 and the output port 4; the control system is electrically connected to the external power supply equipment.

[0054] Among them, the heat storage medium is a fluid medium that can absorb the heat generated by the electric heating tube bundle 3. It can be selected from any one of molten salt, binary molten salt, ternary molten salt, heat transfer oil, supercritical carbon dioxide, liquid metal, and alumina particles according to different application environments and scenarios. The design of the baffle 2 can be refined according to different needs, preferably any one of the following: single bow-shaped baffle, perforated baffle, rectangular baffle, or perforated baffle; All pipes and equipment involved in the recirculation loop are well insulated to reduce heat loss and improve the efficiency of the thermal storage system.

[0055] In one specific embodiment, the area of ​​the baffle plate 2 is greater than half the inner diameter circle area of ​​the shell 1, and there is one and only one space between the baffle plate 2 and the shell 1 to realize the flow of the heat storage medium, and the flow space has a small semi-circular structure. The number of baffles 2 can be designed differently depending on the different heat storage media, but the number must satisfy 2+3n (n=1, 2, 3, ...); preferably, the number of baffles 2 can be 5 to 14, which satisfy 2+3n. Multiple baffles 2 rotate along the central axis of the housing 1. The plane of the baffles 2 is parallel to the longitudinal section of the housing 1. The multiple baffles 2 are divided into n+1 groups along the direction from the input port 10 to the output port 4. The number of baffles 2 in the first n groups is three, and the number of baffles 2 in the last group is two. The three baffles 2 in each of the first n groups correspond to each other, and the corresponding baffles 2 have the same rotation angle.

[0056] In an optional embodiment, the second baffle 2 in any of the first n groups of baffle groups is rotated by a preset angle θ relative to the first baffle 2 along the central axis, and the third baffle 2 is rotated 180° relative to the second baffle 2 along the central axis. The three baffles 2 in any one of the first n groups of baffles and the three baffles 2 in the adjacent baffle group which is also one of the first n groups are corresponding to each other, and the rotation angles of the corresponding two baffles 2 are all 180° apart. The first baffle 2 in the last baffle group is rotated 180° along the central axis relative to the first baffle 2 in the previous baffle group, and the second baffle 2 in the last baffle group is rotated 180° along the central axis relative to the first baffle 2. The preset angle θ ranges from 115° to 155°.

[0057] In a practical application scenario, the baffles 2 of the electric heating device for the heat storage medium are arranged as follows: Figure 4 As shown, in the first group, baffle ② is rotated by an angle θ (115°~155°, preferably 135°) relative to the baffle ① in front of it, and baffle ③ is also rotated by an angle 180° relative to baffle ②; in the second group, baffle ④ is rotated by 180° relative to baffle ① in the first group, baffle ⑤ is rotated by an angle θ (115°~155°, preferably 135°) relative to baffle ④, and so on, while the last baffle ⑧ is rotated by 180° relative to baffle ⑦, thereby realizing the quasi-spiral flow of the heat storage medium.

[0058] The core innovation of this embodiment lies in providing an integrated electric heater device for thermal storage medium that can efficiently transfer heat. Through specific structural design and system integration, it significantly improves heating performance, efficiency and controllability.

[0059] Its key points / innovations are: 1. Unique baffle plate arrangement design: Features: Multiple baffles 2 are arranged sequentially (in sequence) along the flow direction of the heat storage medium, and there is a specific relative rotation angle between adjacent baffles.

[0060] Core effect: By using non-spiral baffles 2 (such as low-cost bow-shaped baffles) to achieve the effect of spiral baffles, this specific spatial arrangement induces the heat storage medium to generate a significant circumferential (rotational) flow component while flowing axially, forming a quasi-spiral flow path, thereby effectively reducing flow dead zones and enhancing heat transfer.

[0061] Advantages: It achieves enhanced heat transfer effects close to those of expensive spiral baffles, but with significantly reduced manufacturing costs and complexity.

[0062] 2. Integrated external thermal storage medium recirculation system: Features: An external forced recirculation loop consisting of a circulating pump 6 and a return pipe 8 is added outside the heating device. This loop draws out a portion of the high-temperature heat storage medium near the output port 4 (high-temperature zone) of the heating device and transports it back to the vicinity of the input port 10 (low-temperature zone) of the heating device, where it mixes with the low-temperature heat storage medium entering the heating device to increase the inlet temperature of the heating device and the initial temperature of the heat storage medium entering the heating device.

[0063] Core functions: ① Inlet preheating: Increases the initial temperature of the heat storage medium entering the heating device. ② Precise temperature control: Achieves rapid and precise adjustment of the outlet temperature by regulating the flow rate (speed or valve opening) of the circulating pump 6. ③ Enhanced flow: Increases the overall driving force of the heat storage medium in the system, promotes internal flow, and reduces dead zones.

[0064] 3. Synergistic optimization effect between the internal baffle plate arrangement and the external recirculation system: Features: The above-mentioned rotating baffle 2 arrangement structure is combined with the external recirculation system, and the temperature sensor 5 is used for feedback to achieve synergistic optimization of heat transfer effect.

[0065] Core methods / effects: ① Start-up phase: Recirculation can be used to quickly increase the inlet temperature and shorten the preheating time. ② Steady-state phase: By combining the adjustment of heating element power and recirculation flow rate, efficient and stable outlet temperature control can be achieved, reducing energy consumption. ③ Dynamic response: Mainly by adjusting the recirculation flow rate to quickly respond to load or setpoint changes, improving control accuracy.

[0066] Those skilled in the art will understand that the above embodiments are merely exemplary, and various modifications and variations can be made without departing from the spirit and scope of this utility model. For example, the specific shape of the baffle 2, the size and sequence of the rotation angle, and the specific connection method of the recirculation loop can all be adjusted. All such modifications and variations should fall within the protection scope of this utility model.

[0067] The specific embodiments of this utility model have been described above. It should be understood that this utility model is not limited to the specific embodiments described above, and those skilled in the art can make various changes or modifications within the scope of the claims, which do not affect the substantive content of this utility model. Unless otherwise specified, the embodiments and features of this utility model can be arbitrarily combined with each other.

Claims

1. An electric heating device for a heat storage medium, characterized in that, The device includes a housing (1), which has an inlet (10) for the inflow of a low-temperature heat storage medium and an outlet (4) for the outflow of a high-temperature heat storage medium. The inlet (10) and the outlet (4) are located at opposite ends of the housing (1). The housing (1) is equipped with multiple sets of electric heating tube bundles (3) and multiple baffles (2). The multiple baffles (2) are arranged sequentially at intervals along the direction from the inlet (10) to the outlet (4). The multiple baffles (2) are arranged to rotate sequentially along the same axis. The multiple baffles (2) are all opposite baffles, or one part is the opposite baffle and the other part is the same baffle, so that the multiple baffles (2) are arranged in a sequential manner to achieve a quasi-spiral flow of the heat storage medium inside the housing (1). When multiple baffles (2) are all opposite baffles, the two baffles (2) adjacent to any one of the baffles (2) have different rotation angles; In the case where one part of the multiple baffles (2) is the opposite baffle and the other part is the same baffle, the two baffles (2) adjacent to any one of the opposite baffles exhibit different rotation angles, and the two baffles (2) adjacent to any one of the same baffles exhibit the same rotation angle.

2. The electric heating device for heat storage medium according to claim 1, characterized in that, The rotating axis is the central axis of the shell (1); the plane of the baffle (2) is parallel to the longitudinal section of the shell (1); the area of ​​the baffle (2) is greater than half the area of ​​the inner diameter circle of the shell (1), and there is only one space between the baffle (2) and the shell (1) to realize the flow of the heat storage medium, and the flow space is in the shape of a small semi-circle; the number of baffles (2) is 2+3n; where n is a positive integer.

3. The electric heating device for heat storage medium according to claim 2, characterized in that, The multiple baffles (2) are divided into n+1 groups along the direction from the input port (10) to the output port (4). The number of baffles (2) in the first n groups is three, and the number of baffles (2) in the last group is two. The three baffles (2) in each of the first n groups correspond to each other, and the corresponding baffles (2) have the same rotation angle.

4. The electric heating device for heat storage medium according to claim 3, characterized in that, When multiple baffles (2) are all opposite baffles, the rotation angle of the last baffle (2) in the first and second baffle groups in the first n groups relative to the previous baffle (2) is a preset angle θ. The distribution pattern of the odd-numbered baffle groups in the first n groups is the same, and the distribution pattern of the even-numbered baffle groups in the first n groups is the same. The first baffle (2) in the last baffle group rotates by the preset angle θ along the central axis relative to the third baffle (2) in the previous baffle group. The second baffle (2) in the last baffle group rotates by the preset angle θ along the central axis relative to the first baffle (2).

5. The electric heating device for heat storage medium according to claim 3, characterized in that, In the case where a portion of the multiple baffles (2) are opposite-direction baffles and another portion are same-direction baffles, the second baffle (2) in any of the first n groups of baffles is rotated by a preset angle θ relative to the first baffle (2) along the central axis, and the third baffle (2) is rotated by 180° relative to the second baffle (2) along the central axis; The three baffles (2) in any one of the first n groups and the three baffles (2) in the baffle group that are adjacent to it and are one of the first n groups are sequentially corresponding, and the rotation angles of the two corresponding baffles (2) are all 180° apart. The first baffle (2) in the last set of baffle groups is rotated 180° relative to the first baffle (2) in the previous set of baffle groups, and the second baffle (2) in the last set of baffle groups is rotated 180° relative to the first baffle (2) in the central axis.

6. An electric heating device for a heat storage medium according to claim 4 or 5, characterized in that, The preset angle θ ranges from 115° to 155°.

7. An electric heating device for a heat storage medium, characterized in that, The device includes an electric heating device for heat storage medium as described in any one of claims 1-6, and the housing (1) is provided with a return port (11) at one end of the output port (4). The return port (11) is connected to the input port (10) through a return pipe (8) so that a portion of the high-temperature heat storage medium flows back to the input port (10) and mixes with the low-temperature heat storage medium input through the input port (10) to increase the temperature of the heat storage medium entering the heating device.

8. The electric heating device for a heat storage medium according to claim 7, characterized in that, A circulation pump (6) is also provided at the return port (11).

9. The electric heating device for a heat storage medium according to claim 8, characterized in that, The return pipe (8) is also provided with a regulating valve (7) and a check valve (9). The regulating valve (7) is located at one end near the return port (11), and the check valve (9) is located at one end near the input port (10).

10. The electric heating device for a heat storage medium according to claim 7, characterized in that, A temperature sensor (5) is also provided at one end of the housing (1) where the output port (4) is located.

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