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 allowing 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 invention further provides a heat storage and exchange module applying the layered overflow pipe.

Description

Technical Field

[0001] The invention 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 Art

[0002] Large-scale power storage systems can effectively solve the instability of renewable energy, adjust the peak and valley of the power grid, and improve the economy and stability of the power system. At present, power grids often use heat storage and heat exchange devices to store electric energy. Heat storage and heat exchange devices often use molten salt as a heat storage medium to convert low-priced electricity at night or abandoned 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, and the superheated steam is used to generate electricity, thereby achieving the purpose of energy saving.

[0003] The existing heat storage and heat exchange device is divided into several layers by a partition plate, that is, from top to bottom, it is divided into a heat storage and heat exchange module, a heat exchange module and a heat release heat exchange module, etc., wherein 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 downward layer by layer through the overflow device, thereby increasing the temperature in the heat exchange module and the heat release heat exchange module.

[0004] At present, 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, structure and device" with patent number CN202210608538.5 (authorization announcement number CN114838611B), including a shell filled with solid heat storage particles, the shell is respectively provided with an overflow port, an overflow pipe and a heat exchange pipe, the overflow pipe connects the overflow port and the fluid outlet of the shell, the highest point of the overflow pipe is higher than the stacking 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 through the overflow pipe and moves downward.

[0005] Although the above-mentioned overflow pipe can allow the molten salt to flow to the lower layer, the inlet of the overflow pipe is located at the top thereof, and the molten salt close to the inlet is more likely to flow into the overflow pipe, that is, the molten salt at the same height as the inlet will flow into the overflow pipe faster, resulting in different flow velocities of the molten salt in the upper and lower areas of the flow cross-section in the heat storage and heat exchange module, and the flow velocity of the molten salt below the inlet is slower. Therefore, the overflow pipe will not only affect the heat exchange efficiency and heat exchange 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, thereby forming a heat exchange "dead zone", and further affecting the working effect of the entire heat storage and heat exchange device.

[0006] Therefore, further improvements need to be made to the overflow pipe and the heat storage and heat exchange module. Summary of the invention

[0007] The first technical problem to be solved by the present invention is to provide a layered overflow pipe capable of overflowing the fluid below the overflow port in view of the above-mentioned existing technical status.

[0008] The second technical problem to be solved by the present invention is to provide a heat storage and heat exchange module that can make each layer of molten salt flow evenly and has higher heat exchange efficiency in response to the above-mentioned existing technical status.

[0009] The technical solution adopted by the present invention to solve the first technical problem is: the layered overflow pipe includes a pipe body for overflow, the opening at the upper end of the pipe body is an overflow port, and is characterized in that: a guide pipe is sleeved and fixed on the outside of the pipe body, the upper end of the guide pipe is an opening and is higher than the overflow port, and the opening at 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 flow guiding tube are coaxially arranged. A connecting piece is provided between the inner wall of the tube body and the outer wall of the flow guiding tube, and the connecting piece fixedly connects the tube body and the flow guiding tube.

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

[0012] Compared with the prior art, the advantages of the present invention are: the stratified overflow pipe is provided with a guide pipe outside the pipe body, and the inlet for the fluid to flow in is arranged at the lower end of the guide pipe, that is, the inlet is arranged downward, and the inlet can be submerged in the fluid; and the flow channel in the guide pipe and the flow channel in the pipe body form an inverted U-shaped channel, so that the fluid below the overflow port can also flow downward through the stratified overflow pipe, avoiding the slow flow of the fluid at the bottom, thereby improving the speed and effect of the fluid flow.

[0013] The technical solution adopted by the present invention to solve the second technical problem is: the heat storage and heat exchange module includes a shell, a flow channel for molten salt flow and a heat exchanger for steam flow are provided in the shell, and the heat exchanger is arranged in the flow channel, and is characterized in that: a plurality of the above-mentioned stratified overflow pipes are provided at the end of the flow channel, and the height of the inlet of the guide pipe of each stratified overflow pipe is inconsistent.

[0014] Preferably, the lengths of the guide tubes are different. The lengths of the guide tubes are different, and the upper ends of the guide tubes are at the same height, so that the entrance heights of the lower ends of the guide tubes are also different.

[0015] In order to increase the contact area between the heat exchanger and the molten salt in the flow channel, preferably, the heat exchanger is formed by stacking a plurality of heat exchange tubes vertically, and the heat exchange tubes are serpentine heat exchange tubes bent in the horizontal direction, one end of the heat exchange tubes 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 tube is opposite to the flow direction of the flow channel, so that the heat exchange between steam and molten salt is more complete, and the temperature of the molten salt after heat exchange is maximized.

[0016] Furthermore, a plurality of baffles are arranged in the shell, and the plurality of baffles are staggered to form a serpentine flow channel, and the heat exchange tubes are arranged along the flow channel. The arrangement of the baffles and the heat exchange tubes can increase the flow of the molten salt and the steam, so that the molten salt and the steam can fully exchange heat, thereby improving the heat exchange efficiency of the heat storage and heat exchange module.

[0017] Furthermore, two heat exchangers are arranged in parallel in the flow channel, so that the contact area between the heat exchangers arranged in parallel and the molten salt in the flow channel is larger, thereby improving the heat exchange effect between the molten salt and the steam.

[0018] In order to optimize the layout of the heat 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 direction of the shell, and the multiple layered overflow pipes are arranged at intervals along the width direction of the shell. The top of the shell is relatively open and connected to the atmosphere. When the heat exchanger fails, the leaked steam can be effectively discharged to prevent the container from being damaged by the pressure of the steam; and because the shell is under normal pressure and the height is often less than one meter, the internal pressure is very low, and there is no need to set the shell to be cylindrical or spherical. The shell with a rectangular structure greatly facilitates the arrangement of the baffles and heat exchange tubes, and effectively reduces the manufacturing difficulty and process requirements of the heat storage and heat exchange module.

[0019] In order to make the molten salt flow more uniformly, preferably, an overflow pipe is further provided at the end of the flow channel, and the opening of the upper end of the overflow pipe is higher than the inlet of the guide pipe. The overflow pipe is a vertically arranged pipe body, so that the molten salt above the inlet of the guide pipe can flow downward through the overflow pipe, so that the molten salt of each layer can flow downward, thereby making the molten salt flow more uniform.

[0020] Compared with the prior art, the advantages of the present invention are that: the heat storage and heat exchange module is also provided with a plurality of layered overflow pipes at the end of the flow channel, and the outer part of the tube body of the layered overflow pipe is sleeved with a guide pipe, so that the high-temperature molten salt after heat exchange can flow into the guide pipe from the inlet of the guide pipe, and then the high-temperature molten salt flows into the overflow port of the tube body from the connecting port of the guide pipe, so that the high-temperature molten salt flows downward through the layered overflow pipe; and the inlet height of each guide pipe is different, so that the molten salt can flow evenly in the upper and lower areas of the flow cross section, that is, each layer of the 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, thereby enhancing the reliability of the molten salt heat exchange and improving the efficiency of the molten salt heat exchange. BRIEF DESCRIPTION OF THE DRAWINGS

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

[0022] Figure 2 is a cross-sectional view of embodiment 1 of the present invention;

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

[0024] Figure 4 Schematic diagram of the structure of Embodiment 2 of the present invention from another viewing angle (part of the housing is omitted);

[0025] Figure 5 Schematic diagram of the structure of the baffle in Example 2 of the present invention (part of the shell is omitted);

[0026] Figure 6 1 is a top view of the heat exchanger in Example 2 of the present invention. DETAILED DESCRIPTION

[0027] The present invention is further described in detail below with reference to the accompanying drawings.

[0028] like Figure 1 and Figure 2 The example 1 of the present invention is shown.

[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, and the inner wall of the pipe body 1 and the outer wall of the guide pipe 2 are welded to the wall.

[0030] Therefore, the stratified overflow pipe of the present embodiment is provided with a guide pipe 2 outside the pipe body 1, and an inlet 21 for fluid inflow is arranged at the lower end of the guide pipe 2, that is, the inlet 21 is arranged downward, and the inlet 21 can be submerged in the fluid; and the flow channel in the guide pipe 2 and the flow channel in the pipe body 1 form an inverted U-shaped channel, so that the fluid below the overflow port 11 can also flow downward through the stratified 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, and the fluid flows downward through the pipe body 1.

[0031] like Figures 3 to 6 The example 2 of the present invention is shown.

[0032] like Figures 3 to 6 As shown, the heat storage heat exchange module of this embodiment includes a shell 3, a plurality of baffles 4 and a heat exchanger 5 for steam flow are arranged in the shell 3, the shell 3 is a rectangular cavity structure with an open top, the heat exchanger 5 is arranged along the length direction of the shell 3, and the plurality of baffles 4 are staggeredly arranged in the shell 3 along the length direction of the shell 4. The plurality of baffles 4 are staggered to form a serpentine flow channel 41 for molten salt flow, the heat exchanger 5 is arranged in the flow channel 41, and the end of the flow channel 41 is provided with three layered overflow pipes of Example 1 and an overflow pipe 6, and the layered overflow The flow pipe and the overflow pipe 6 are arranged at intervals at the end of the flow channel 41 along the width direction of the shell 3, wherein the height of the inlet 21 of the guide pipe 2 of each layered overflow pipe is inconsistent, that is, the length of each guide pipe 2 is inconsistent, and the upper end of each guide pipe 2 is at the same height, so that the height of the inlet 21 at the lower end of each guide pipe 2 is different; and 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] Two heat exchangers 5 are provided in the flow channel 41 of the present embodiment. The two heat exchangers 5 are arranged side by side. The heat exchanger 5 is formed by a plurality of heat exchange tubes 51 stacked vertically. The heat exchange tubes 51 are serpentine heat exchange tubes bent in the horizontal direction. The heat exchange tubes 51 are arranged along the flow channel 41. One end of the heat exchange tubes 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 tubes 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 the heat exchange is maximized.

[0034] The working process 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, and the 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. The low-temperature molten salt is converted into high-temperature molten salt after heat exchange with the heat exchanger 5 and flows out from the end of the flow channel 41. The high-temperature steam in the heat exchanger 5 is converted into low-temperature steam or condensed water after cooling and flows out from the outlet 512 of the heat exchange tube 51. Heat storage and heat exchange module; after the high-temperature molten salt flows out from the flow channel 41, the high-temperature molten salt higher than the overflow pipe 6 flows directly into the lower layer from the opening at the upper end of the overflow pipe 6, and the remaining high-temperature molten salt flows into the guide pipe 2 through the inlet 21 of the guide pipe 2 of the stratified overflow pipe, and then flows into the lower layer through the pipe body 1 of the stratified overflow pipe. Therefore, each layer of molten salt can stably flow downward through the overflow pipe 6 and the stratified overflow pipe, heat the heat exchange module and the heat release heat exchange module of the lower layer, and make the entire heat storage and heat exchange device operate.

Claims

1. A layered 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 flow guide tube (2) is sleeved and fixed on the outside of the tube body (1); the upper end of the flow guide tube (2) is open and higher than the overflow port (11); the opening at the lower end of the flow guide tube (2) is an inlet (21) for fluid to flow in; and the inlet (21) is higher than the lower end of the tube body (1).

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

3. The layered overflow pipe according to claim 1, characterized in that: The inner wall of the tube body (1) and the outer wall of the flow guide tube (2) are welded to each other.

4. A heat storage and heat exchange module, comprising a shell (3), wherein a flow channel (41) for molten salt to flow and a heat exchanger (5) for steam to flow are provided in the shell (3), wherein the heat exchanger (5) is arranged in the flow channel (41), and wherein: A plurality of layered overflow pipes as claimed in any one of claims 1 to 3 are provided at the end of the flow channel (41), and the heights of the inlets (21) of the guide pipes (2) of each of the layered overflow pipes are inconsistent.

5. The heat storage and heat exchange module according to claim 4, characterized in that: The lengths of each of the flow guide pipes (2) are inconsistent.

6. The heat storage and heat exchange module according to claim 4, characterized in that: The heat exchanger (5) is formed by stacking a plurality of heat exchange tubes (51) in a vertical direction. The heat exchange tubes (51) are serpentine heat exchange tubes that are bent in a horizontal direction. One end of the heat exchange tubes (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: A plurality of baffles (4) are arranged in the shell (3); the baffles (4) are arranged in a staggered manner to form a serpentine flow channel (41); and the heat exchange tubes (51) are arranged along the flow channel (41).

8. The heat storage and heat exchange module according to claim 4, characterized in that: Two heat exchangers (5) are arranged in the flow channel (41), and the two heat exchangers (5) 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 direction of the shell (3), and a plurality of layered overflow pipes are arranged at intervals along the width direction of the shell (3).

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

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