Fused salt forced heat exchange and energy storage device and system

Abstract

The utility model provides a molten salt forced heat exchange energy storage device and system, the molten salt forced heat exchange energy storage device comprises a tank body and a heating pipe fitting which is arranged in the tank body and extends along the height direction of the tank body, the heating pipe fitting comprises an electric heater and a jacketed pipe, the jacketed pipe is sleeved and wrapped on the outer side of the electric heater, and the jacketed pipe and the electric heater are coaxially arranged; the outer wall of the electric heater and the inner wall of the jacketed pipe are matched to form a vertically-arranged heating channel used for circulating and heating fused salt. A molten salt pump is further arranged in the tank body, a first input port and a first output port are formed in the bottom and the top of the jacketed pipe correspondingly, the first input port is connected with the molten salt pump, molten salt is pumped into the first input port under the action of the molten salt pump, and the molten salt forcibly flows through the heating channel and makes contact with the outer wall of the electric heater for heat exchange and then is discharged out of the first output port. Fused salt forced circulation heat exchange operation is achieved. According to the forced heat exchange energy storage device and system for the fused salt, the heat exchange efficiency of the fused salt can be effectively improved through forced heat exchange operation on the fused salt.

Description

Technical Field

[0001] The utility model belongs to the technical field of molten salt heating, and in particular relates to a molten salt forced heat exchange energy storage device and system. Background Art

[0002] With the continuous growth of energy demand and the rapid development of the renewable energy industry, user-side energy storage, as an important energy storage and management technology, has gradually become a key link in future energy development. Among them, the molten salt heat storage technology that uses the temperature difference of molten salt in the process of heating and cooling to achieve thermal energy storage has been widely used in solar thermal power generation and industrial fields. The conventional molten salt heat storage system is a double-tank heat storage system, which consists of two independent high-temperature tanks and low-temperature tanks to achieve heat storage and heat release operations under different working modes. However, the double-tank heat storage system is complex, requires a large space, and has a high investment cost. Therefore, a single-tank heat storage system is improved on the basis of the double-tank heat storage system. However, under the existing technology, the commonly used heating method mainly relies on the built-in electric heater to directly heat the molten salt, that is, relying on the density difference of the molten salt to make the molten salt naturally convectively transfer heat, and take away the heat generated by the electric heater during the contact between the molten salt and the electric heater, so that the molten salt temperature increases, but this heating method makes the heat transfer coefficient on the molten salt side very small, the heat transfer time is long, and the heat transfer efficiency is low, which cannot meet the molten salt heating requirements of large-scale and efficient production operations. Utility Model Content

[0003] The technical problem to be solved by the utility model is to provide a molten salt forced heat exchange energy storage device and system to solve the technical problem of low heat exchange efficiency of existing molten salt heat exchange devices.

[0004] In order to solve the above problems, the technical solution of the utility model is: a molten salt forced heat exchange energy storage device, comprising a tank body and a heating pipe arranged inside the tank body and extending along the height direction of the tank body, the heating pipe comprising an electric heater and a jacket pipe, the jacket pipe is wrapped around the outside of the electric heater and is coaxially arranged with the electric heater, and the outer wall of the electric heater and the inner wall of the jacket pipe cooperate to form a vertically arranged heating channel for circulating and heating molten salt;

[0005] A molten salt pump is provided in the tank body on one side of the heating pipe fitting, and a first input port and a first output port are respectively provided at the bottom and the top of the jacket pipe, the first input port is connected to the molten salt pump, and the heating pipe fitting is configured so that the first input port pumps molten salt into the molten salt under the action of the molten salt pump, and the molten salt is forced to flow through the heating channel and contact with the outer wall of the electric heater for heat exchange, and then discharged from the first output port, thereby realizing the forced circulation heat exchange operation of the molten salt.

[0006] Preferably, the molten salt pump is a vertical submersible pump provided with a pump body base, and the molten salt pump is defined as an above-the-liquid component at the part above the pump body base, and a below-the-water component at the part below the pump body base, the above-the-liquid component is arranged on the outside of the tank body, the submersible component is arranged on the inside of the tank body and extends along the height direction of the tank body, the pump body base is fixedly connected to the top cover plate of the tank body, the bottom of the submersible component extends to the bottom of the molten salt layer, a second input port is provided at the bottom end of the submersible component toward the bottom of the tank body on one side for absorbing molten salt, a second output port is provided laterally at the bottom of the submersible component for discharging molten salt, and the second output port is connected to the first input port through a molten salt channel.

[0007] Preferably, the horizontal height of the first output port is lower than the liquid level of the molten salt in the tank.

[0008] Preferably, the number of the heating pipes is set to m groups, 1≤m≤4, and the heating pipes are evenly distributed along the central axis of the tank body toward the side wall of the tank body.

[0009] Preferably, the number of the molten salt channels and the second output ports are respectively set to n, 1≤n≤4, and the number of the molten salt channels and the second output ports matches the number of the heating pipes.

[0010] Preferably, a fixing portion is provided at the bottom of the heating pipe, and two ends of the fixing portion are fixedly connected to the outer wall of the bottom of the jacket pipe and the inner wall of the bottom of the tank body respectively.

[0011] Preferably, the electric heater comprises a plurality of tubular heating rods arranged in parallel.

[0012] Preferably, the tank wall is provided with heat-insulating material.

[0013] Preferably, a plurality of temperature sensors are provided on the inner wall of the tank body, and the temperature sensors are used to monitor the temperature of the molten salt in the tank body.

[0014] Based on the same concept, the utility model also provides a molten salt forced heat exchange energy storage system, including any one of the molten salt forced heat exchange energy storage devices described above.

[0015] Due to the adoption of the above technical solution, the utility model has the following advantages and positive effects compared with the prior art:

[0016] The utility model provides a molten salt forced heat exchange energy storage device and system, which is provided with an electric heater and a jacketed pipe. The electric heater and the jacketed pipe are arranged to form a vertical heating channel. The molten salt is pumped into the bottom of the heating channel under the action of a molten salt pump, and then gradually fills and moves upward from the bottom space of the heating channel, so that the molten salt is fully in contact with the outer wall of the electric heater to achieve heat exchange, and then flows out from the top of the heating channel. Compared with natural convection circulation heating, the utility model adopts forced circulation heating to effectively improve the convection heat transfer coefficient of molten salt electric heating. The molten salt is in full contact with the electric heater, which greatly shortens the heat exchange time, and the molten salt is made to flow through the molten salt pump, which improves the heat transfer efficiency of the electric heater and improves the safety of the electric heater during use. In addition, the number of heating pipes can be added according to actual needs, and the heating pipes are evenly distributed in the tank body. Heat exchange operations are performed at the same time, which can further effectively improve the heat exchange efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 The front view of the molten salt forced heat exchange energy storage device provided by the utility model;

[0018] Figure 2 A top view of the molten salt forced heat exchange energy storage device provided by the utility model;

[0019] Figure 3 Top view b of the molten salt forced heat exchange energy storage device provided by the utility model.

[0020] Explanation of the reference numerals: 1: tank body; 2: heating pipe; 21: electric heater; 22: jacket pipe; 23: heating channel; 24: first input port; 25: first output port; 3: molten salt pump: 31: second input port; 32: second output port; 33: pump body base; 34: above-liquid component; 35: below-liquid component; 4: molten salt channel. DETAILED DESCRIPTION

[0021] The following is a further detailed description of a molten salt forced heat exchange energy storage device and system proposed by the utility model in combination with the accompanying drawings and specific embodiments. The advantages and features of the utility model will become clearer according to the following description and claims.

[0022] First embodiment

[0023] See also Figure 1 to Figure 2In a molten salt forced heat exchange energy storage device provided in this embodiment, a heating pipe 2 is provided inside the tank body 1, and the heating pipe 2 extends along the height direction of the tank body 1 and is arranged at the central axis position of the tank body 1, wherein the heating pipe 2 includes an electric heater 21 and a jacket pipe 22, the jacket pipe 22 is sleeved and wrapped around the outside of the electric heater 21, and the jacket pipe 22 and the electric heater 21 are arranged coaxially, and there is a certain gap between the inner wall of the jacket pipe 22 and the outer wall of the electric heater 21, and the two cooperate to form a heating channel 23 for vertical circulation and heating of molten salt. Among them, a first input port 24 is provided at the bottom of the jacket pipe 22, and the first input port 24 is connected to the heating channel 23, and the molten salt is input into the heating channel 23 through the first input port 24, and a first output port 25 is provided at the top of the jacket pipe 22, and the first output port 25 is connected to the heating channel 23, and the molten salt that has been heated in the heating channel 23 is output through the first output port 25.

[0024] A molten salt pump 3 is also provided on one side of the heating pipe fitting 2 in the tank body 1, and the output end of the molten salt pump 3 is connected to the first input port 24. During the molten salt forced heat exchange operation, the molten salt is pumped into the heating channel 23 inside the heating pipe fitting 2 from the first input port 24 under the action of the molten salt pump 3. The molten salt already in the heating channel 23 overcomes its own gravity and moves from the bottom of the heating channel 23 to the top and fills the heating channel 23 under the extrusion force of the molten salt continuously pumped into the bottom, so that the molten salt is in full contact with the outer wall of the electric heater 21, and takes away the heat generated by the electric heater 21 during the movement. Finally, the molten salt after heating moves to the first output port 25 and flows out and returns to the molten salt layer of the tank body 1, preparing for the next cycle of heat exchange until all the molten salts reach the set temperature.

[0025] In a molten salt forced heat exchange energy storage device provided in this embodiment, the molten salt heat exchange operation realizes forced circulation by relying on the action of the molten salt pump 3, and the convective heat transfer coefficient of the molten salt is effectively improved through the circulation of the molten salt, which greatly increases the total contact area between the molten salt and the electric heating tube wall during the heating process, and changes from static contact to dynamic contact, thereby improving the ability of heat exchange, greatly shortening the heat exchange time, and effectively improving the heat exchange efficiency. At the same time, the molten salt is continuously circulated due to forced circulation, so that the heat generated by the electric heater 21 is dissipated faster as the molten salt circulates, avoiding the electric heater 21 from exceeding the safety temperature setting due to poor heat dissipation, thereby improving the safety of the electric heater 21 during the heat exchange process.

[0026] Preferably, the molten salt pump 3 is a vertical submersible pump, which is provided with a pump body base 33, which limits the molten salt pump 3 to be placed vertically, and the molten salt pump 3 is provided with a liquid upper component 34 above the pump body base 33, and a liquid lower component 35 below the pump body base 33, wherein the pump body base 33 is fixedly connected to the top cover plate of the tank body 1 to ensure the stability of the molten salt pump 3, and the liquid upper component 34 includes components such as a motor and an expansion joint, which are arranged outside the cover plate of the tank body 1, and the liquid lower component 35 is arranged inside the tank body 1 and extends along the height direction of the tank body 1. The bottom of the submersible component 35 extends to the bottom of the molten salt layer. The bottom of the submersible component 35 is provided with a second input port 31 on the side facing the bottom of the tank body 1 for absorbing the bottom molten salt. The actual setting height of the second input port 31 is stipulated to be as deep as possible to the bottom of the molten salt layer without affecting the absorbing action of the molten salt pump 3, so that the molten salt is absorbed from the bottom of the molten salt layer during the absorption process, thereby improving the overall fluidity of the molten salt and extending the length of the heating channel 23 that matches the length of the submersible component 35, further reducing the heating time and improving the heating efficiency. A second output port 32 is provided laterally at the bottom of the submersible component 35 for outputting the molten salt pumped in through the second input port 31. At the same time, the second output port 32 maintains the same horizontal height as the first input port 24 and is connected through the molten salt channel 4, so that the molten salt pumped by the molten salt pump 3 is transmitted to the heating channel 23, and with the help of the continuous absorption and pressurization of the molten salt pump 3, the forced circulation of the molten salt in the heating channel 23 is realized.

[0027] Furthermore, the horizontal height of the first output port 25 is set to be slightly lower than the liquid level of the molten salt in the tank body 1, so as to reduce heat loss and improve heating efficiency.

[0028] Preferably, at least three sets of fixing parts are provided at the bottom of the heating pipe 2, and the two ends of the fixing parts are respectively welded and fixedly connected to the bottom of the jacket tube 22 and the bottom of the tank body 1, to ensure that the heating pipe 2 can maintain a stable posture during the heat exchange process of the molten salt circulation, thereby improving the safety of the use of the molten salt forced heat exchange energy storage device.

[0029] Preferably, the electric heater 21 is provided with a plurality of parallel tubular heating rods in the vertical direction, so as to further increase the contact area between the heating region of the electric heater 21 and the molten salt, and improve the heat exchange efficiency of the molten salt during the contact and heat exchange process with the electric heater 21 .

[0030] Preferably, the surrounding walls and the top cover of the tank body 1 are provided with heat-insulating materials to improve the heat storage performance of the molten salt forced heat exchange energy storage device and reduce heat loss, that is, shorten the molten salt heating time and reduce the heating cost.

[0031] Preferably, a plurality of groups of temperature sensors are provided on the inner wall of the tank body 1 at the coverage height of the molten salt layer, which are used to detect the temperature of the molten salt in real time. The temperature sensor is arranged on the inner wall of the tank body 1 to detect the temperature of the peripheral molten salt away from the position of the central heating pipe 2. The heating rate of the peripheral molten salt during the heat exchange process is lower than that of the central molten salt. By detecting the data of the temperature sensor arranged on the inner wall of the tank body 1, it can be confirmed whether the temperature of the molten salt in the tank body 1 has reached the heating temperature setting standard.

[0032] Second embodiment

[0033] See also Figure 3 In a molten salt forced heat exchange energy storage device provided in this embodiment, the number of heating pipes 2 can be set to m groups, where 1≤m≤4, and each heating pipe 2 is evenly distributed along the central axis of the tank body 1 toward the side wall of the tank body 1, that is, each heating pipe 2 is evenly distributed inside the tank body 1. At the same time, the number of molten salt channels 4 and the second output port 32 are respectively set to n, where 1≤n≤4, and the number of molten salt channels 4 and the second output port 32 matches the number of heating pipes 2. In this embodiment, the molten salt pump 3 is arranged at the center position of each heating pipe fitting 2, that is, the center axis position of the tank body 1, and a unique second input port 31 and a plurality of second output ports 32 are provided at the bottom. The second output ports 32 are respectively connected with the first input ports 24 at the bottom of the plurality of heating pipe fittings 2 through the corresponding molten salt channels 4. After the molten salt pump 3 absorbs the molten salt, the molten salt is diverted to the plurality of heating pipe fittings 2 to perform heat exchange operations at the same time. After multiple sets of theoretical data analysis and experimental verification, the m groups of heating pipe fittings 2 arranged in this embodiment can greatly improve the heat exchange efficiency of the molten salt forced heat exchange energy storage device under the premise of comprehensively considering the use cost.

[0034] Third embodiment

[0035] Based on the same concept, the present embodiment provides a molten salt forced heat exchange energy storage system, including any of the molten salt forced heat exchange energy storage devices described above. During the molten salt heat exchange process, the molten salt is sucked by the molten salt pump 3 through the molten salt channel 4 to transfer the molten salt to the bottom of the heating channel 23 of the heating pipe 2, and under the extrusion force generated by the continuous delivery of the molten salt by the molten salt pump 3, the molten salt located in the heating channel 23 overcomes its own gravity and moves along the height direction of the heating channel 23 and gradually fills the heating channel 23. In the heating channel 23, the molten salt is fully in contact with the outer wall of the electric heater 21 to achieve heat exchange. During the movement, the molten salt continuously takes away the heat generated by the electric heater 21. Finally, the molten salt after the heat exchange treatment flows out from the first output port 25 at the top of the heating channel 23, returns to the molten salt layer in the tank body 1, and waits for the next cycle until the temperature sensor arranged on the inner wall of the tank body 1 detects that the temperature of the molten salt in the tank body 1 has reached the set temperature range, the electric heater 21 and the molten salt pump 3 stop working, and the molten salt forced heat exchange operation ends. In a molten salt forced heat exchange energy storage system provided in this embodiment, compared with the traditional heating mode, this embodiment uses a molten salt pump 3 to realize the circulation of internal molten salt, and sets a vertical heating channel 23, so that the molten salt is in full contact with the outer wall of the electric heater 21 during the circulation process, and static heating is improved to dynamic heating, which improves the convection heat transfer coefficient of molten salt electric heating, greatly improves the heat exchange efficiency, and reduces the heat exchange time. At the same time, the dynamic flow of molten salt is used to improve the heat exchange efficiency while avoiding the poor heat dissipation of the electric heater 21, effectively ensuring the safety performance of the molten salt forced heat exchange energy storage system.

[0036] The above is a detailed description of the embodiments of the present invention in conjunction with the accompanying drawings, but the present invention is not limited to the above embodiments. Even if various changes are made to the present invention, if these changes fall within the scope of the claims of the present invention and their equivalents, they still fall within the protection scope of the present invention.

Claims

1. A molten salt forced heat exchange energy storage device, It is characterized in that It comprises a tank body and a heating pipe member arranged inside the tank body and extending along the height direction of the tank body, wherein the heating pipe member comprises an electric heater and a jacket pipe, wherein the jacket pipe is wrapped around the outside of the electric heater and is coaxially arranged with the electric heater, and the outer wall of the electric heater and the inner wall of the jacket pipe cooperate to form a vertically arranged heating channel for circulating and heating molten salt; A molten salt pump is provided in the tank body on one side of the heating pipe fitting, and a first input port and a first output port are respectively provided at the bottom and the top of the jacket pipe, the first input port is connected to the molten salt pump, and the heating pipe fitting is configured so that the first input port pumps molten salt into the molten salt under the action of the molten salt pump, and the molten salt is forced to flow through the heating channel and contact with the outer wall of the electric heater for heat exchange, and then discharged from the first output port, thereby realizing the forced circulation heat exchange operation of the molten salt.

2. A molten salt forced heat exchange energy storage device as claimed in claim 1, It is characterized in that The molten salt pump is a vertical submersible pump, provided with a pump body base, and it is defined that the part of the molten salt pump above the pump body base is an above-liquid component, and the part below the pump body base is a submersible component, the above-liquid component is arranged outside the tank body, the submersible component is arranged inside the tank body and extends along the height direction of the tank body, the pump body base is fixedly connected to the top cover plate of the tank body, the bottom of the submersible component extends to the bottom of the molten salt layer, the bottom end of the submersible component is provided with a second input port facing the bottom of the tank body on one side for absorbing molten salt, and the bottom of the submersible component is provided with a second output port on the side for discharging molten salt, and the second output port is connected to the first input port through a molten salt channel.

3. A molten salt forced heat exchange energy storage device as claimed in claim 1, It is characterized in that The horizontal height of the first output port is lower than the liquid level of the molten salt in the tank.

4. A molten salt forced heat exchange energy storage device as claimed in claim 2, It is characterized in that The number of the heating pipes is set to m groups, 1≤m≤4, and the heating pipes are evenly distributed along the central axis of the tank body toward the side wall of the tank body.

5. A molten salt forced heat exchange energy storage device as claimed in claim 4, It is characterized in that The number of the molten salt channels and the second output ports are respectively set to n, 1≤n≤4, and the number of the molten salt channels and the second output ports matches the number of the heating pipes.

6. A molten salt forced heat exchange energy storage device as claimed in claim 1, It is characterized in that A fixing part is provided at the bottom of the heating pipe, and two ends of the fixing part are fixedly connected to the outer wall of the bottom of the jacket pipe and the inner wall of the bottom of the tank body respectively.

7. A molten salt forced heat exchange energy storage device as claimed in claim 1, It is characterized in that The electric heater comprises a plurality of tubular heating rods arranged in parallel.

8. A molten salt forced heat exchange energy storage device as claimed in claim 1, It is characterized in that The wall surface of the tank body is provided with heat-insulating material.

9. A molten salt forced heat exchange energy storage device as claimed in claim 1, It is characterized in that The inner wall of the tank is provided with a plurality of temperature sensors, and the temperature sensors are used to monitor the temperature of the molten salt in the tank.

10. A molten salt forced heat exchange energy storage system, It is characterized in that A molten salt forced heat exchange energy storage device comprising any one of claims 1 to 9.

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