Layered overflow pipe and heat storage and heat exchange module

Abstract

A layered overflow pipe comprises a pipe body for overflowing, an opening at the upper end of the pipe body is an overflow port, and the layered overflow pipe is characterized in that a flow guide pipe is sleeved and fixed outside the pipe body, the upper end of the flow guide pipe is an opening and is higher than the overflow port, an opening at the lower end of the flow guide pipe is an inlet for fluid to flow in, and the inlet is higher than the lower end of the pipe body. Compared with the prior art, the layered overflow pipe has the advantages that the flow guide pipe is arranged outside the pipe body of the layered overflow pipe, the inlet for fluid to flow in is formed in the lower end of the flow guide pipe, and the flow channel in the flow guide pipe and the flow channel in the pipe body form an inverted U-shaped channel, so that the fluid lower than the overflow port can flow downwards through the layered overflow pipe; the slow flowing of the fluid at the bottom is avoided, so that the flowing speed and effect of the fluid are improved. The embodiment of the utility model further provides a heat storage and exchange module applying the layered overflow pipe.

Description

Technical Field

[0001] This utility model relates to the field of heat storage and heat exchange devices, and in particular to a layered overflow pipe and a heat storage and heat exchange module. Background Technology

[0002] Large-scale power storage systems can effectively address the instability of renewable energy, adjust peak and off-peak power grids, and improve the economic efficiency and stability of the power system. Currently, power grids often use thermal energy storage devices to store electrical energy. These devices typically use molten salt as the heat storage medium, converting low-cost electricity generated at night or surplus wind and solar power into high-temperature molten salt for storage. When electricity is needed, the high-temperature molten salt is fully exchanged with water to generate superheated steam, which is then used to generate electricity, thus achieving energy conservation.

[0003] The existing heat storage and heat exchange device is divided into several layers by a partition plate, namely, from top to bottom, it is divided into heat storage and heat exchange module, heat exchange module and heat release and heat exchange module, etc. Among them, the heat storage and heat exchange module is located at the top of the heat storage and heat exchange device. After the molten salt in the heat storage and heat exchange module exchanges heat with the heat exchanger, it moves down layer by layer through the overflow device, so that the temperature in the heat exchange module and the heat release and heat exchange module rises.

[0004] Currently, the overflow device of the heat storage and heat exchange module is shown in the Chinese invention "A High Temperature Heat Exchange and Heat Storage Module and Structure and Device" with patent number CN202210608538.5 (authorization announcement number CN114838611B). It includes a shell filled with solid heat storage particles. The shell is provided with an overflow port, an overflow pipe and a heat exchange pipe. The overflow pipe connects the overflow port to the fluid outlet of the shell. The highest point of the overflow pipe is higher than the accumulation height of the solid heat storage particles in the shell and lower than the top of the shell. When the liquid level of the heat transfer fluid is higher than the overflow port of the overflow pipe, the heat transfer fluid after sufficient heat exchange overflows and moves downward through the overflow pipe.

[0005] Although the overflow pipe allows molten salt to flow downwards, its inlet is located at the top. Molten salt near the inlet flows into the overflow pipe more easily, meaning that molten salt at the same height as the inlet flows into the overflow pipe faster. This results in different flow velocities of the molten salt in the heat storage and heat exchange module across different regions of the flow cross-section. The molten salt below the inlet flows more slowly. Therefore, the overflow pipe not only affects the heat exchange efficiency and effect of the molten salt in the heat storage and heat exchange module, but may also cause the flow of molten salt in some areas to almost stop, thus forming a heat exchange "dead zone" and affecting the overall working effect of the heat storage and heat exchange device.

[0006] Therefore, further improvements are needed for the overflow pipe and the heat storage and heat exchange module. Summary of the Invention

[0007] The first technical problem to be solved by this utility model is to provide a layered overflow pipe that allows fluid below the overflow port to overflow, in light of the aforementioned existing technology.

[0008] The second technical problem to be solved by this utility model is to provide a heat storage and heat exchange module that can make each layer of molten salt flow uniformly and has higher heat exchange efficiency, in view of the above-mentioned existing technology.

[0009] The technical solution adopted by this utility model to solve the first technical problem is as follows: the layered overflow pipe includes a pipe body for overflow, the opening at the upper end of the pipe body is an overflow port, characterized in that: a guide pipe is sleeved and fixed outside the pipe body, the upper end of the guide pipe is an opening and higher than the overflow port, the lower end of the guide pipe is an inlet for fluid to flow in, and the inlet is higher than the lower end of the pipe body.

[0010] Preferably, the tube body and the guide tube are arranged coaxially. A connector is provided between the inner wall of the tube body and the outer wall of the guide tube, and the connector fixes the tube body and the guide tube together.

[0011] Preferably, the inner wall of the tube body is welded to the outer wall of the guide tube. The tube body and the guide tube are fixedly connected by welding.

[0012] Compared with the prior art, the advantages of this utility model are as follows: the layered overflow pipe has a guide pipe on the outside of the pipe body, and the inlet for fluid inflow is set at the lower end of the guide pipe, that is, the inlet is set downward and can be submerged in the fluid; and the flow channel inside the guide pipe and the flow channel inside the pipe body form an inverted U-shaped channel, so that the fluid below the overflow port can also flow downward through the layered overflow pipe, avoiding the slow flow of fluid at the bottom, thereby improving the speed and effect of fluid flow.

[0013] The technical solution adopted by this utility model to solve the second technical problem is as follows: the heat storage and heat exchange module includes a shell, and the shell is provided with a flow channel for molten salt flow and a heat exchanger for steam flow. The heat exchanger is arranged in the flow channel. The feature is that: the end of the flow channel is provided with a plurality of the above-mentioned layered overflow pipes, and the inlet height of the guide pipe of each layered overflow pipe is not consistent.

[0014] Preferably, the length of each of the guide tubes is not uniform. Since the length of each guide tube is different and the upper end of each guide tube is at the same height, the inlet height at the lower end of each guide tube is also different.

[0015] To increase the contact area between the heat exchanger and the molten salt in the flow channel, preferably, the heat exchanger is composed of multiple heat exchange tubes stacked vertically. These heat exchange tubes are serpentine tubes that bend horizontally. One end of each heat exchange tube is an inlet for steam to flow in, and the other end is an outlet for steam to flow out. The inlet is located at the end of the flow channel, and the outlet is located at the beginning of the flow channel. The flow direction of the heat exchange tubes is opposite to that of the flow channel, allowing for more complete heat exchange between the steam and the molten salt, maximizing the temperature of the molten salt after heat exchange.

[0016] Furthermore, the housing is equipped with multiple baffles arranged in an alternating pattern to form a serpentine flow channel, and the heat exchange tubes are arranged along the flow channel. The arrangement of the baffles and heat exchange tubes can increase the flow path of molten salt and steam, allowing for sufficient heat exchange between the molten salt and steam, and improving the heat exchange efficiency of the heat storage module.

[0017] Furthermore, the flow channel is equipped with two heat exchangers arranged side by side. The side-by-side arrangement of the heat exchangers results in a larger contact area with the molten salt in the flow channel, improving the heat exchange effect between the molten salt and the steam.

[0018] To optimize the layout of the thermal storage and heat exchange module, preferably, the shell is a rectangular cavity structure with an open top. The heat exchanger is arranged along the length of the shell, and multiple layered overflow pipes are spaced apart along the width of the shell. The top of the shell is relatively open and communicates with the atmosphere. When the heat exchanger fails, the leaked steam can be effectively discharged, preventing the container from being damaged by steam pressure. Furthermore, since the shell is under atmospheric pressure and its height is often less than one meter, its internal pressure is very low. Therefore, there is no need to make the shell cylindrical or spherical. The rectangular shell structure greatly facilitates the arrangement of baffles and heat exchange tubes, effectively reducing the manufacturing difficulty and process requirements of the thermal storage and heat exchange module.

[0019] To ensure more uniform molten salt flow, preferably, an overflow pipe is provided at the end of the flow channel, with the opening at the upper end of the overflow pipe higher than the inlet of the guide pipe. This overflow pipe is a vertically arranged tube, allowing molten salt above the inlet of the guide pipe to flow downwards through the overflow pipe, ensuring that each layer of molten salt flows downwards, thus making the molten salt flow more uniform.

[0020] Compared with the prior art, the advantages of this utility model are as follows: the heat storage and heat exchange module is provided with multiple layered overflow pipes at the end of the flow channel. The overflow pipes are fitted with guide pipes. The high-temperature molten salt after heat exchange can flow into the guide pipe from the inlet. Then, the high-temperature molten salt flows into the overflow port of the pipe body from the connection port of the guide pipe, so that the high-temperature molten salt flows downward through the layered overflow pipes. Moreover, the inlet height of each guide pipe is different, so that the molten salt can flow evenly in the upper and lower regions of the flow cross section. That is, each layer of molten salt at the end of the flow channel can flow into the layered overflow pipe through the guide pipe. Therefore, the molten salt in the heat storage and heat exchange module can flow stably, which enhances the reliability of molten salt heat exchange and improves the efficiency of molten salt heat exchange. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of the structure of Embodiment 1 of the present utility model;

[0022] Figure 2 This is a cross-sectional view of Embodiment 1 of the present utility model;

[0023] Figure 3 This is a schematic diagram of the structure of Embodiment 2 of the present invention;

[0024] Figure 4 This is a schematic diagram of the structure of Embodiment 2 of the present invention from another perspective (part of the shell is omitted);

[0025] Figure 5 This is a schematic diagram of the baffle plate in Embodiment 2 of this utility model (part of the shell is omitted);

[0026] Figure 6 This is a top view of the heat exchanger in Embodiment 2 of this utility model. Detailed Implementation

[0027] The present invention will be further described in detail below with reference to the accompanying drawings and embodiments.

[0028] like Figure 1 and Figure 2 As shown, this is Embodiment 1 of the present invention.

[0029] like Figure 1 and Figure 2 As shown, the layered overflow pipe of this embodiment includes a pipe body 1 for overflow. The opening at the upper end of the pipe body 1 is an overflow port 11. A guide pipe 2 is sleeved and fixed on the outside of the pipe body 1. The upper end of the guide pipe 2 is an opening and is higher than the overflow port 11. The opening at the lower end of the guide pipe 2 is an inlet 21 for fluid to flow in. The inlet 21 is higher than the lower end of the pipe body 1. The inner wall of the pipe body 1 is welded to the outer wall of the guide pipe 2.

[0030] Therefore, in this embodiment, the layered overflow pipe is provided with a guide pipe 2 outside the pipe body 1. The inlet 21 for fluid inflow is located at the lower end of the guide pipe 2, that is, the inlet 21 is set downwards and can be submerged in the fluid. Furthermore, the flow channel inside the guide pipe 2 and the flow channel inside the pipe body 1 form an inverted U-shaped channel, so that the fluid below the overflow port 11 can also flow downwards through the layered overflow pipe. That is, the fluid below the overflow port 11 flows into the guide pipe 2 from the inlet 21, and then flows into the pipe body 1 through the opening at the upper end of the guide pipe 2 and the overflow port 11 of the pipe body 1. The fluid flows downwards through the pipe body 1.

[0031] like Figures 3-6 As shown, this is Embodiment 2 of the present invention.

[0032] like Figures 3-6 As shown, the heat storage and heat exchange module of this embodiment includes a shell 3, inside which are provided multiple baffles 4 and a heat exchanger 5 for steam flow. The shell 3 is a rectangular cavity structure with an open top. The heat exchanger 5 is arranged along the length of the shell 3. Multiple baffles 4 are arranged alternately along the length of the shell 3, forming a serpentine flow channel 41 for molten salt flow. The heat exchanger 5 is disposed within the flow channel 41. At the end of the flow channel 41 are three stratified overflow pipes as in Embodiment 1 and one overflow pipe 6. The overflow pipes and overflow pipes 6 are spaced apart at the end of the flow channel 41 along the width direction of the shell 3. The inlet 21 of the guide pipe 2 of each layer of overflow pipe is at a different height, that is, the length of each guide pipe 2 is different. The upper end of each guide pipe 2 is at the same height, so that the inlet 21 of the lower end of each guide pipe 2 is at a different height. Furthermore, the opening at the upper end of the overflow pipe 6 is higher than the inlet 21 of the guide pipe 2, so that the molten salt above the inlet 21 of the guide pipe 2 can flow downward through the overflow pipe 6, so that the molten salt of each layer can flow downward, thereby making the molten salt flow more uniform.

[0033] In this embodiment, two heat exchangers 5 are provided in the flow channel 41. The two heat exchangers 5 are arranged side by side. The heat exchangers 5 are formed by stacking multiple heat exchange tubes 51 vertically. The heat exchange tubes 51 are serpentine heat exchange tubes that are bent in the horizontal direction. The heat exchange tubes 51 are arranged along the flow channel 41. One end of the heat exchange tube 51 is an inlet 511 for steam to flow in, and the other end is an outlet 512 for steam to flow out. The inlet 511 is located at the end of the flow channel 41, and the outlet 512 is located at the beginning of the flow channel 41. The flow direction of the heat exchange tube 51 is opposite to the flow direction of the flow channel 41, so that the heat exchange between the steam and the molten salt is more complete, and the temperature of the molten salt after heat exchange is maximized.

[0034] The workflow of this embodiment is as follows: When the heat storage and heat exchange module is storing heat, high-temperature and high-pressure steam enters the heat exchanger 5 from the inlet 511 of each heat exchange tube 51. Low-temperature molten salt enters the flow channel 41 from the beginning of the flow channel 41 through the action of the molten salt pump. After heat exchange with the heat exchanger 5, the low-temperature molten salt becomes high-temperature molten salt and flows out from the end of the flow channel 41. The high-temperature steam in the heat exchanger 5 is cooled and becomes low-temperature steam or condensate, which flows out from the outlet 512 of the heat exchange tube 51. The heat storage and heat exchange module: After the high-temperature molten salt flows out from the flow channel 41, the high-temperature molten salt that is higher than the overflow pipe 6 flows directly into the lower layer from the opening at the upper end of the overflow pipe 6, while the remaining high-temperature molten salt flows into the guide pipe 2 through the inlet 21 of the guide pipe 2 of the layered overflow pipe, and then flows into the lower layer through the pipe body 1 of the layered overflow pipe. Therefore, each layer of molten salt can flow down steadily through the overflow pipe 6 and the layered overflow pipe, heating the heat exchange module and the heat release heat exchange module of the lower layer, so that the entire heat storage and heat exchange device can operate.

Claims

1. A tiered overflow pipe, comprising a pipe body (1) for overflow, wherein the opening at the upper end of the pipe body (1) is an overflow port (11), characterized in that: A guide pipe (2) is sleeved and fixed on the outside of the pipe body (1). The upper end of the guide pipe (2) is open and higher than the overflow port (11). The lower end of the guide pipe (2) is an inlet (21) for fluid to flow in. The inlet (21) is higher than the lower end of the pipe body (1).

2. The stratified overflow pipe according to claim 1, characterized in that: The tube body (1) and the guide tube (2) are arranged coaxially.

3. The stratified overflow pipe according to claim 1, characterized in that: The inner wall of the tube body (1) is welded to the outer wall of the guide tube (2).

4. A heat storage and heat exchange module, comprising a housing (3), wherein the housing (3) is provided with a flow channel (41) for molten salt flow and a heat exchanger (5) for steam flow, the heat exchanger (5) being disposed within the flow channel (41), characterized in that: The flow channel (41) is provided with a plurality of layered overflow pipes as described in any one of claims 1 to 3 at its end, and the height of the inlet (21) of the guide pipe (2) of each layered overflow pipe is not consistent.

5. The heat storage and heat exchange module according to claim 4, characterized in that: The length of each of the aforementioned guide tubes (2) is not uniform.

6. The heat storage and heat exchange module according to claim 4, characterized in that: The heat exchanger (5) is composed of multiple heat exchange tubes (51) stacked vertically. The heat exchange tubes (51) are serpentine heat exchange tubes that bend horizontally. One end of the heat exchange tube (51) is an inlet (511) for steam to flow in, and the other end is an outlet (512) for steam to flow out. The inlet (511) is located at the end of the flow channel (41), and the outlet (512) is located at the beginning of the flow channel (41).

7. The heat storage and heat exchange module according to claim 6, characterized in that: The shell (3) is provided with multiple baffles (4), which are arranged in an alternating manner to form a serpentine flow channel (41), and the heat exchange tube (51) is arranged along the flow channel (41).

8. The heat storage and heat exchange module according to claim 4, characterized in that: The flow channel (41) is provided with two heat exchangers (5), which are arranged side by side.

9. The heat storage and heat exchange module according to claim 4, characterized in that: The shell (3) is a rectangular cavity structure with an open top. The heat exchanger (5) is arranged along the length of the shell (3). The multiple layered overflow pipes are spaced apart along the width of the shell (3).

10. The heat storage and heat exchange module according to claim 4, characterized in that: The flow channel (41) is also provided with an overflow pipe (6) at its end, and the opening at the upper end of the overflow pipe (6) is higher than the inlet (21) of the guide pipe (2).

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