A vertical radial flow regenerator

Abstract

The application discloses a vertical radial flow cold accumulator, which comprises a vertical shell, the bottom of the shell is provided with supporting feet, wherein the inside of the shell is provided with a concentric cylinder which is arranged concentrically with the shell and comprises two cylinders with a certain interval; the concentric cylinder divides the inside space of the shell into a flow distribution channel, a filling layer and a flow collecting channel from outside to inside along the radial direction of the shell, a buffer cavity which is communicated with the flow distribution channel is formed between the bottom of the concentric cylinder and the bottom of the shell; the filling layer is respectively communicated with the flow distribution channel and the flow collecting channel in the radial direction, the inside of the filling layer is filled with energy storage medium for forming a bed layer and a filler seal which is arranged on the top of the energy storage medium and used for preventing airflow short circuit after the energy storage medium is settled; a flow guide cone which is gradually reduced in diameter along the axial direction is arranged in the flow distribution channel or the flow collecting channel. The application can make the bed layer have smaller resistance and more uniform airflow distribution, improve the effective utilization rate of space and energy storage performance, and is favorable for the large-scale development of the cold accumulator.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of energy storage devices, in particular to a vertical radial flow cold accumulator. BACKGROUND

[0002] With the growth of the world population and the acceleration of industrialization, the demand for energy continues to rise. Energy storage technology can improve the balance of energy supply and demand, reduce the gap between peak and valley energy consumption, and enhance the country's resistance to energy crisis. Among many energy storage technologies, cold storage technology has the advantages of large scale, low cost, long service life, and cross-season storage, and is gradually becoming the leader of future energy storage. Its core equipment is a cold accumulator.

[0003] Using solid packed bed for cold storage has the advantages of not being limited by operating temperature zone, safety and environmental protection, and lower cost. For large-scale energy storage systems, vertical axial flow cold accumulators have the problems of large system resistance, uneven flow field distribution, and small effective space utilization. These problems have a negative impact on the energy storage system, thereby affecting the round-trip efficiency of the energy storage system. SUMMARY

[0004] The technical problem to be solved by the present application is to provide a vertical radial flow cold accumulator, which can solve the problems of uneven flow field distribution, large bed resistance and small space utilization efficiency in the prior art, thereby improving the performance of the cold accumulator and ensuring high-quality and efficient operation of the medium and large cold accumulator.

[0005] To solve the above technical problems, the technical solutions adopted by the present application are as follows.

[0006] A vertical radial flow cold accumulator includes a vertically arranged shell, and a support foot is arranged at the bottom of the shell. The interior of the shell is suspended with a concentric cylinder, which is arranged concentrically with the shell and includes two concentric and spaced sleeve cylinders. The concentric cylinder divides the internal space of the shell along the radial direction of the shell into a flow dividing channel, a filling layer and a flow collecting channel arranged in sequence from the outside to the inside. The filling layer is filled with energy storage medium for forming a bed layer and a filler seal arranged at the top of the energy storage medium for preventing airflow short circuit after the energy storage medium settles.

[0007] The upper part of the concentric cylinder is two top parts connected with the top part of the shell and bottom parts flush with each other, and the packing seal is arranged between the two non-porous annular steel rings; the middle and lower part of the concentric cylinder is an outer annular grid corresponding to the bottom part of the two non-porous annular steel rings one by one and connected with the bottom part of the two non-porous annular steel rings, and an inner annular grid located inside the outer annular grid, and the energy storage medium is filled between the outer annular grid and the inner annular grid; the bottom part of the concentric cylinder is a circular non-porous steel plate connected with the bottom part of the outer annular grid and the inner annular grid and arranged in a spaced manner with the bottom part of the shell to form a buffer cavity in communication with the shunt channel between the bottom part of the shell.

[0008] The shunt channel or the flow channel is provided with a flow guide cone which gradually decreases in diameter along the axial direction to keep the flow rate of the energy storage and release gas flow consistent when passing through the filling layer from axial to radial.

[0009] Preferably, the grid of the outer annular grid and the inner annular grid is wound with a wire mesh.

[0010] Preferably, the packing seal is filled with a packing medium made of the same material as the energy storage medium.

[0011] Preferably, the top part of the shell is provided with a first heat exchange fluid inlet and outlet coaxially arranged with the shell and in communication with the flow channel; and the bottom part of the shell is provided with a second heat exchange fluid inlet and outlet coaxially arranged with the shell and in communication with the buffer cavity.

[0012] Preferably, a metal compensator is arranged on the first heat exchange fluid inlet and outlet to eliminate the temperature alternating stress generated in the energy storage and release cycle, and a flange is arranged on the top part of the metal compensator; and the second heat exchange fluid inlet and outlet is communicated with a heat exchange fluid pipeline, and an ash removal port is arranged on the heat exchange fluid pipeline.

[0013] Preferably, the top part of the shell is provided with a first packing port in communication with the inside of the packing seal, and a packing seal heat exchange fluid inlet and a second packing port and a packing seal heat exchange fluid outlet.

[0014] Preferably, the shell comprises a shell outer wall and a shell inner wall, and an insulating layer is arranged between the shell outer wall and the shell inner wall to prevent energy loss through the shell during heat exchange.

[0015] Preferably, the concentric cylinder is suspended in the shell inner wall through the arranged bearing channel steel.

[0016] Preferably, the arrangement method of the concentric cylinder and the annular grid opening rate of the outer annular grid and the inner annular grid of the concentric cylinder in the shell is as follows:

[0017] Obtaining the basic parameters of the vertical radial flow regenerator and the heat exchange fluid; setting the annular grid opening rate epsilon and the cross section ratio n of the collecting channel and the distributing channel, based on the basic parameters of the vertical radial flow regenerator, using the porous medium model and the porous jump model, a two-dimensional axisymmetric initial physical model of the vertical radial flow regenerator is established;

[0018] On the basis of the initial physical model, the values of epsilon and n are changed respectively, different physical models of the vertical radial flow regenerator are built, the corresponding heat exchange fluid velocity field distribution under the energy storage and release process is obtained, and then the airflow uniformity and flow resistance in the bed under the energy storage and release process are obtained.

[0019] The airflow uniformity in the bed is compared and analyzed, and the values of epsilon and n corresponding to the physical model with the highest airflow uniformity and relatively small flow resistance in the bed are determined.

[0020] Due to the adoption of the above technical scheme, the technical progress achieved by the present application is as follows.

[0021] The present application can reduce the bed resistance and improve the space utilization rate by the setting of the concentric cylinders; the flow rate of the energy storage and release airflow can remain consistent when passing through the filling layer along the axial direction to the radial direction by the setting of the outer annular grid, the inner annular grid and the flow guide cone, which can effectively weaken the problem of uneven flow field distribution. BRIEF DESCRIPTION OF DRAWINGS

[0022] Figure 1 The present application is a structural schematic view.

[0023] 1. shell, 101. shell outer wall, 102. shell inner wall, 2. concentric cylinder, 201. non-porous annular steel ring, 202. outer annular grid, 203. inner annular grid, 3. heat insulation layer, 4. distributing channel, 5. filling layer, 6. collecting channel, 7. bearing channel steel, 8. packing seal, 9. first packing port and packing seal heat exchange fluid inlet, 10. metal compensator, 11. flange, 12. first heat exchange fluid inlet and outlet, 13. second packing port and packing seal heat exchange fluid outlet, 14. flow guide cone, 15. energy storage medium, 16. second heat exchange fluid inlet and outlet, 17. supporting leg. DETAILED DESCRIPTION

[0024] The present application will be further described in detail below in combination with the drawings and specific embodiments.

[0025] A vertical radial flow regenerator, which combines Figure 1As shown, it comprises a vertical shell 1, and a concentric cylinder 2 is arranged concentrically inside the shell 1. The concentric cylinder 2 comprises two concentric cylinders with a certain interval, and the concentric cylinder 2 divides the internal space of the shell 1 into a flow distribution channel 4, a filling layer 5 and a flow collection channel 6 from outside to inside along the radial direction of the shell 1. The filling layer 5 is filled with energy storage medium 15, and the filling of the energy storage medium 15 and the filling layer 5 form a bed layer. At the same time, the filling layer 5 is ventilated radially through the concentric cylinder 2 and the flow distribution channel 4 and the flow collection channel 6 respectively. It has the characteristics of large windward area, small bed layer resistance, bed layer space volume accounting for more than 50% of the equipment volume, and high space utilization efficiency. Therefore, the vertical radial flow cold storage device has advantages in medium and large energy storage projects.

[0026] Specifically, the energy storage medium 15 is a solid particle such as rain flower stone, glass, basalt, concrete, granite, sodium chloride, dolomite, etc., or a phase change material encapsulated capsule particle. In order to prevent the airflow from being short-circuited after the energy storage medium 15 settles, a certain amount of filler medium is filled in the filler seal 8 arranged on the upper part of the concentric cylinder 2, and the filler medium is the same material as the energy storage medium 15. The top of the shell 1 is provided with a first filler port and a filler seal heat transfer fluid inlet 9 and a second filler port and a filler seal heat transfer fluid outlet 13, which are in communication with the inside of the filler seal 8. Because the filler seal 8 may form a local "dead space", the temperature of the "dead space" can be quickly adjusted to be consistent with the temperature of the energy storage medium 15 in the filling layer 5 through the first filler port and the filler seal heat transfer fluid inlet 9 and the second filler port and the filler seal heat transfer fluid outlet 13, so as to weaken the adverse effects of the heat exchange process and the dynamic characteristics of the energy storage and release interval on the temperature field inside the filling layer 5.

[0027] The upper part of the concentric cylinder 2 is two non-hole annular steel rings 201, the top of the two non-hole annular steel rings 201 is connected with the top of the shell 1, and the bottom of the two non-hole annular steel rings 201 is flush, and the packing seal 8 is arranged between the two non-hole annular steel rings 201. The middle and lower part of the concentric cylinder 2 is an outer annular grid 202 and an inner annular grid 203 located inside the outer annular grid 202, the top of the outer annular grid 202 and the inner annular grid 203 is connected with the bottom of the two non-hole annular steel rings 201 one by one, the outer annular grid 202 and the inner annular grid 203 are used for respectively communicating the filling layer 5 with the shunt channel 4 and the collecting channel 6, realizing that the filling layer 5 is respectively radially ventilated with the shunt channel 4 and the collecting channel 6, at the same time, the grid inside the outer annular grid 202 and the inner annular grid 203 is wound with a wire mesh, and the wire mesh and the outer annular grid 202 and the inner annular grid 203 are made of metal materials; the energy storage medium 15 is located at the lower part of the packing seal 8 and is filled between the outer annular grid 202 and the inner annular grid 203. The bottom of the concentric cylinder 2 is a circular non-hole steel plate, which can be convex or flat, the circular non-hole steel plate is connected with the bottom of the outer annular grid 202 and the inner annular grid 203, and the circular non-hole steel plate is arranged at intervals with the bottom of the shell 1, so that a buffer cavity is formed between the bottom of the shell 1, and the buffer cavity is communicated with the shunt channel 4.

[0028] The top of the shell 1 is provided with a first heat exchange fluid inlet and outlet 12, the first heat exchange fluid inlet and outlet 12 is coaxially arranged with the shell 1, and the first heat exchange fluid inlet and outlet 12 is provided with a metal compensator 10, the metal compensator 10 is used for eliminating temperature alternating stress generated in the energy storage and release process, the top of the metal compensator 10 is provided with a flange 11 for maintenance. The bottom of the shell 1 is provided with a second heat exchange fluid inlet and outlet 16, the second heat exchange fluid inlet and outlet 16 is coaxially arranged with the shell 1, and the second heat exchange fluid inlet and outlet 16 is communicated with a heat exchange fluid pipeline, and the heat exchange fluid pipeline is provided with a dust discharge port.

[0029] The collecting channel 6 as the passage of the heat exchange fluid is communicated with the first heat exchange fluid inlet and outlet 12 at the top of the shell 1; the shunt channel 4 as the passage of the heat exchange fluid is communicated with the second heat exchange fluid inlet and outlet 16 at the bottom of the shell 1 through the buffer cavity. The flow guide cone 14 is arranged in the collecting channel 6 or the shunt channel 4, the diameter of the flow guide cone 14 gradually decreases along the axial direction, so that the flow velocity of the energy storage and release airflow remains consistent when the airflow passes through the filling layer 5 along the axial direction to the radial direction, which can effectively weaken the problem of uneven flow field distribution.

[0030] The shell 1 comprises a shell outer wall 101 and a shell inner wall 102, and the shell outer wall 101 and the shell inner wall 102 are made of metal materials with small thermal conductivity and high strength. An adiabatic layer 3 is arranged between the shell outer wall 101 and the shell inner wall 102, and the adiabatic layer 3 is one of a polyurethane foam layer, a glass fiber layer, a foam glass layer, an aerogel glass fiber felt layer, a neoprene and diene foam layer, an aluminum foil glass fiber cloth layer, an expanded perlite layer, a vacuum layer or other adiabatic materials. The arrangement of the adiabatic layer 3 can effectively prevent the loss of energy through the shell 1 during heat exchange.

[0031] A bearing channel steel 7 is arranged between the shell 1 and the concentric cylinder 2, and the bearing channel steel 7 is used for suspending the concentric cylinder 2 in the shell inner wall 102. The bottom of the shell 1 is provided with supporting feet 17, and the shell outer wall 101 and the shell inner wall 102 are supported by the supporting feet 17; or the shell inner wall 102 is supported on the shell outer wall 101, and the shell outer wall 101 is supported by the supporting feet 17.

[0032] In use, the shell 1 can be used as a cold accumulator or a heat accumulator. Through the arrangement of the concentric cylinder 2, the outer annular grid 202, the inner annular grid 203 and the flow guide cone 14, the bed layer resistance is small, the airflow distribution is more uniform, the space utilization rate and the energy storage characteristics are improved, and the scale development of heat storage and cold storage is facilitated.

[0033] When used as a heat accumulator, heat storage and heat release cycles can be carried out; when used as a cold accumulator, cold storage and cold release cycles can be carried out. The cold storage and cold release process will be described in detail below.

[0034] In the cold storage process, the low-temperature heat exchange fluid enters the cold accumulator through the second heat exchange fluid inlet and outlet 16, enters the buffer cavity at the bottom of the shell 1, and directly contacts and exchanges heat with the energy storage medium 15 through the outer annular grid 202. The fluid after heat exchange flows into the collecting channel 6 from the inner annular grid 203, is uniformly pressed by the flow guide cone 14, and then flows out of the shell 1 through the first heat exchange fluid inlet and outlet 12. When the outlet fluid temperature reaches the cut-off temperature, the low-temperature heat exchange fluid is switched to the next cold accumulator, and a low-temperature fluid is introduced into the first filler port and the filler seal heat exchange fluid inlet 9 to exchange heat with the filler medium in the filler seal 8 until the temperature of the fluid at the second filler port and the filler seal heat exchange fluid outlet 13 reaches the cold storage cut-off temperature. Then, the regulating valves of the first heat exchange fluid inlet and outlet 12 and the second heat exchange fluid inlet and outlet 16 are closed, and the cold storage process of the cold accumulator is completed.

[0035] During the cold releasing process, the normal temperature heat exchange fluid enters the accumulator through the first heat exchange fluid inlet and outlet 12, is uniformly distributed through the flow guide cone 14 and the flow channel 6, and then flows into the filling layer 5 through the inner annular grid 203 to exchange heat with the energy storage medium 15. The cooled heat exchange fluid flows out of the accumulator through the outer annular grid 202, the flow channel 4 and the bottom buffer cavity of the shell 1, and then flows out of the accumulator through the second heat exchange fluid inlet and outlet 16. When the temperature of the outlet fluid reaches the cut-off temperature, the normal temperature heat exchange fluid is switched to the next accumulator, and a normal temperature fluid is introduced into the first filler port and the filler seal heat exchange fluid inlet 9 to exchange heat with the filler medium in the filler seal 8 until the temperature of the fluid at the second filler port and the filler seal heat exchange fluid outlet 13 reaches the cold releasing cut-off temperature. Then, the regulating valves of the first heat exchange fluid inlet and outlet 12 and the second heat exchange fluid inlet and outlet 16 are closed, and the cold releasing process of the accumulator is completed.

[0036] The difference between the heat storage and release process and the cold storage and release process is that the flow direction of the heat exchange fluid is opposite. In the heat storage process, the high-temperature heat exchange fluid enters the accumulator from the top first heat exchange fluid inlet and outlet 12 and flows out of the accumulator from the bottom second heat exchange fluid inlet and outlet 16. In the heat release process, the normal temperature heat exchange fluid flows into the accumulator from the bottom second heat exchange fluid inlet and outlet 16 and flows out of the accumulator from the top first heat exchange fluid inlet and outlet 12.

[0037] According to the size of the accumulator and the material and particle size of the energy storage medium 15, the annular grid opening rate ε of the outer annular grid 202 and the inner annular grid 203 of the concentric cylinder 2 and the cross-sectional ratio n of the flow channel 6 and the flow channel 4 have a great influence on the uniformity of the axial airflow in the energy storage and release process. The following method can effectively weaken the axial heat conduction and further improve the energy storage performance of the accumulator.

[0038] Specifically, the annular grid opening rate and the arrangement method of the concentric cylinder 2 in the shell 1 are as follows: obtain the basic parameters of the vertical radial flow accumulator and the heat exchange fluid, wherein the basic parameters of the vertical radial flow accumulator include the inner diameter of the shell, the height of the filling layer, the bed voidage, the equivalent diameter of the energy storage medium and the porosity thereof; the basic parameters of the heat exchange fluid include the flow rate, viscosity and density of the heat exchange fluid.

[0039] Set the annular grid opening rate ε and the cross-sectional ratio n of the flow channel 6 and the flow channel 4, based on the basic parameters of the vertical radial flow accumulator and the control equations of the fluid, namely the continuity equation and the momentum conservation equation, simplify the energy storage medium bed and the annular grid by using the porous medium model and the porous jump model, and reflect the energy storage medium bed and the annular grid through the calculation of the voidage, the equivalent diameter of the particles and the resistance term, to establish a two-dimensional axisymmetric initial physical model of the vertical radial flow accumulator.

[0040] For the homogeneous energy storage medium, the momentum source term in the momentum equation can be simplified as:

[0041]

[0042] where S i is the momentum source term in the i direction; μ is the dynamic viscosity; ρ is the fluid density; |v| is the magnitude of the velocity; α represents the permeability; C2 represents the inertial resistance factor. Both of them can be calculated by the Euler formula, which is applicable to a wide range of Reynolds numbers and various filling modes, and has the form as follows:

[0043]

[0044] where ξ is the porosity of the packed layer; d p is the equivalent diameter of the energy storage medium. Due to the relatively large value of the perforation velocity, the inertial resistance term plays a dominant role, and the viscous resistance term can be ignored. The momentum source term at the ring grid can be expressed as:

[0045]

[0046] where A f is the opening area of the ring grid; A p is the total surface area of the ring grid; C is the coefficient, which is related to the Reynolds number and the ratio of the plate thickness to the hole diameter t / D. When t / D>1.6 and Re>4000, C takes 0.98.

[0047] On the basis of the initial physical model, different physical models of the radial flow cold storage device were established by changing the values of ε and n respectively, and the corresponding heat transfer fluid velocity field distribution under the energy storage and release process was obtained. Then the gas flow uniformity and flow resistance in the bed layer under the energy storage and release process were obtained. Through comparative analysis of the gas flow uniformity in the bed layer, the values of ε and n corresponding to the physical model with the highest gas flow uniformity and relatively small flow resistance were determined.

Claims

1. A vertical radial flow cold accumulator comprising a vertical casing (1) provided at the bottom with supporting feet (17), characterized in that: The inside of the shell (1) is provided with a concentric cylinder (2) which is arranged concentrically with the shell (1) and comprises two concentric and spaced sleeve cylinders; the concentric cylinder (2) divides the internal space of the shell (1) into a flow distribution channel (4), a filling layer (5) and a flow collection channel (6) arranged in sequence from outside to inside along the radial direction of the shell (1); the filling layer (5) is filled with energy storage medium (15) for forming a bed layer and is provided with a filler seal (8) located at the top of the energy storage medium (15) for preventing airflow short circuit after the energy storage medium (15) settles; The upper part of the concentric cylinder (2) is two non-porous annular steel rings (201) whose top parts are connected with the top of the shell (1) and whose bottom parts are flush; the filler seal (8) is arranged between the two non-porous annular steel rings (201); the top of the shell (1) is provided with a first filler port, a filler seal heat exchange fluid inlet (9) and a second filler port and a filler seal heat exchange fluid outlet (13) which are in communication with the inside of the filler seal (8); the middle and lower part of the concentric cylinder (2) is an outer annular grid (202) and an inner annular grid (203) which are connected with the bottom parts of the two non-porous annular steel rings (201) one by one and are used to respectively communicate the filling layer (5) with the flow distribution channel (4) and the flow collection channel (6); the energy storage medium (15) is filled between the outer annular grid (202) and the inner annular grid (203); the bottom part of the concentric cylinder (2) is a circular non-porous steel plate which is connected with the bottom parts of the outer annular grid (202) and the inner annular grid (203) and is arranged spaced apart from the bottom of the shell (1) to form a buffer cavity which is in communication with the flow distribution channel (4) between the bottom of the shell (1) and the bottom part of the concentric cylinder (2); The flow distribution channel (4) or the flow collection channel (6) is provided with a flow guide cone (14) which gradually decreases in diameter along the axial direction so that the flow velocity of the energy storage and release gas flow remains consistent when it passes through the filling layer (5) from axial to radial direction; The arrangement method of the concentric cylinder (2) and the annular grid opening rate of the outer annular grid (202) and the inner annular grid (203) on the concentric cylinder (2) in the shell (1) is as follows: The basic parameters of the vertical radial flow cold accumulator and the heat exchange fluid are obtained; the annular grid opening rate ε and the cross-sectional ratio n of the flow collection channel (6) and the flow distribution channel (4) are set; based on the basic parameters of the vertical radial flow cold accumulator, a two-dimensional axisymmetric initial physical model of the vertical radial flow cold accumulator is established by using the porous medium model and the porous jump model; Based on the initial physical model, the values of ε and n are changed respectively to build different physical models of the vertical radial flow cold accumulator, and the corresponding heat exchange fluid velocity field distribution under the energy storage and release process is obtained, and then the corresponding airflow uniformity and flow resistance in the bed layer under the energy storage and release process are obtained; The airflow uniformity in the bed layer is compared and analyzed to determine the values of ε and n corresponding to the physical model with the highest airflow uniformity and relatively small flow resistance in the bed layer.

2. A vertical radial flow cold accumulator according to claim 1, characterized in that: The outer annular grid (202) and the inner annular grid (203) are both wound with wire mesh.

3. A vertical radial bed regenerator according to claim 1, wherein: The filler seal (8) is filled with a filler medium of the same material as the energy storage medium (15).

4. A vertical radial bed regenerator according to claim 1, wherein: A first heat exchange fluid inlet and outlet (12) coaxial with the shell (1) and communicating with the current collector (6) is formed in the top of the shell (1); a second heat exchange fluid inlet and outlet (16) coaxial with the shell (1) and communicating with the buffer cavity is formed in the bottom of the shell (1).

5. A vertical radial bed regenerator according to claim 4, wherein: A metal compensator (10) for eliminating temperature alternating stress generated in the energy storage and release cycle is arranged on the first heat exchange fluid inlet and outlet (12), and a flange (11) is arranged on the top of the metal compensator (10); the second heat exchange fluid inlet and outlet (16) is communicated with a heat exchange fluid pipeline, and an ash removal port is arranged on the heat exchange fluid pipeline.

6. A vertical radial bed regenerator according to claim 1, wherein: The shell (1) comprises a shell outer wall (101) and a shell inner wall (102), and an insulating layer (3) for preventing energy loss through the shell (1) during heat exchange is arranged between the shell outer wall (101) and the shell inner wall (102).

7. A vertical radial bed regenerator according to claim 6, wherein: The concentric cylinder (2) is suspended in the shell inner wall (102) through the arranged bearing channel steel (7).

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