An interlaced baffle moving bed reactor for thermochemical energy storage

Abstract

This invention discloses a staggered baffle moving bed reactor for thermochemical energy storage, comprising a shell, baffles, a gas inlet, a gas outlet, a packing port, and a discharge port. The gas inlet and discharge port are located at the bottom of the shell, and the gas outlet and packing port are located at the top of the shell. The baffles are arranged from top to bottom inside the shell, with the front and rear ends of each baffle abutting against the front and rear ends of the shell, respectively. The lateral length of each baffle is less than the distance between the left and right ends of the shell. The higher ends of adjacent baffles are located near different sides of the shell, and the angles between adjacent baffles and the horizontal plane are complementary. This invention can enhance the heat exchange performance of the moving bed reactor, increase the reaction rate and reaction conversion rate per unit time, and improve energy storage efficiency.

Description

Technical Field

[0001] This invention belongs to the field of thermochemical energy storage technology, specifically relating to an alternating baffle moving bed reactor for thermochemical energy storage. Background Technology

[0002] Thermochemical energy storage is a highly efficient and inexpensive energy storage method. Compared with traditional sensible heat energy storage and phase change energy storage, it has advantages such as high energy density, long-distance transportation capability, and long-term storage. This energy storage method relies on devices such as reactors to collect and release energy.

[0003] Currently, in the field of thermochemical energy storage, there are three main types of commonly used reactor devices: fixed bed, fluidized bed, and moving bed. Fixed bed and fluidized bed reactors have simple structures, but the former, due to the accumulation of reactants, relies primarily on heat conduction, resulting in a low overall heat transfer coefficient and poor heat and mass transfer performance. This leads to slow reaction rates, low energy storage efficiency, and frequent "dead zones." Furthermore, it cannot achieve continuous loading and unloading of reactants, requiring intermittent operation. Additionally, its large pressure drop results in high energy consumption. Fluidized bed reactors suffer from drawbacks such as easy wear and tear on reactants and high energy consumption. Moving bed reactors combine the advantages of fixed and fluidized beds. While maintaining low energy consumption, clever structural design ensures that reactants do not accumulate on a large scale, while also enhancing heat exchange to a certain extent. They also allow for continuous loading and unloading of materials, ensuring an uninterrupted energy storage / release process.

[0004] Literature (Sahlani, A. A., Randhir, K., Ozalp, N., and Klausner, J. (March 7, 2022). "A Forward Feedback Control Scheme for a Solar Thermochemical Moving Bed Counter-Current Flow Reactor." ASME. J. Sol. Energy Eng. June 2022; 144(3): 031004.), Literature (Cosquillo Mejia, A., Afflerbach, S., Linder, M., Schmidt, M. Development of a Moving Bed Reactor for Thermochemical Heat Storage Based on Granulated Ca(OH)2. Processes 2022, 10, 1680), Literature (Saleh, N.S.; Alaqel, S.; Djajadiwinata, E.; Saeed, R.S.; Al-Suhaibani, Z.; Zeitoun, O.; Al-Ansary, H.; Alswaiyd, A.; El-Leathy, A.; Danish, S.; Jeter, S.; Byman, A.; Jordison, N.; Moon, D. Experimental Investigation of a Moving Packed-Bed Heat Exchanger Suitable for Concentrating Solar Power Applications. Appl. Sci. 2022, 12, 4055.), and Literature (Wan, Q.; Zhao, Z.; Wang, R.; Tang, M.; Wang, D.; Zhang, S.; Hu, B. Characteristics of Gas–Solid Flow in an Intermittent Countercurrent Moving Bed. Processes 2022, 10, 2116.The moving bed countercurrent reactor reported in the article suffers from several problems due to its straight-through bed structure. Solid particles fall rapidly and vertically under gravity, concentrating at the bottom of the bed. Furthermore, the heating section of the bed is relatively short. These issues lead to short particle residence time in the reaction zone, uneven heat exchange, large-scale particle accumulation, incomplete reaction, and low reaction rate and conversion per unit time.

[0005] The shell-and-tube moving bed reactor reported in the literature (AC Mejía, Afflerbach S, Linder M, et al. Experimental analysis of encapsulated CaO / Ca(OH)2 granules as thermochemical storage in a novel moving bed reactor[J]. Applied Thermal Engineering, 2020, 169:114961.) has problems such as short particle residence time, weak heat diffusion capacity, uneven heat exchange, slow reaction rate, and low reaction conversion rate per unit time due to the straight-through cylindrical structure of the bed and the use of indirect heating. Furthermore, the solid particles in the bed do not directly contact the high-temperature medium, and there is a lack of convective heat transfer inside the bed. Heat exchange mainly relies on the wall surface and the heating fluid, with heat transferred from the outside to the inside.

[0006] The literature (He Zicong, Lu Xiaofeng, Wang Xueshen, et al. Study on heat exchange characteristics of a new moving bed ash cooler for circulating fluidized bed boilers [J]. Journal of Electric Power Engineering, 2022, 37(06): 494-506.) reports a cross-flow moving bed for waste heat recovery of boiler bottom ash. This moving bed increases the contact area between air and solids in the bed by side air supply. However, the air inlets of this reactor are staggered S-shaped and discontinuous. In addition, the bed body is a straight cubic shape. Solids entering the bed body fall directly and rapidly vertically under the action of gravity, resulting in uneven heat exchange, solid accumulation at the bottom of the bed, slow reaction rate, and low reaction conversion rate per unit time.

[0007] To address the problems of short reactant residence time, weak heat exchange capacity, uneven heat exchange, incomplete reaction, low reaction rate and low reaction conversion rate per unit time in existing moving bed reactors, it is necessary to develop a new type of moving bed reactor for thermochemical energy storage to solve these problems. Summary of the Invention

[0008] Technical problem solved: To address the above-mentioned technical problems, the present invention provides an alternating baffle moving bed reactor for thermochemical energy storage, which can improve the heat exchange performance of the moving bed reactor, increase the reaction rate of reactants and the reaction conversion rate per unit time, and improve the energy storage efficiency.

[0009] Technical solution: A staggered baffle moving bed reactor for thermochemical energy storage includes a shell, baffles, a gas inlet, a gas outlet, a packing port, and a discharge port; the gas inlet and discharge port are located at the bottom of the shell, and the gas outlet and packing port are located at the top of the shell; the baffles are arranged inside the shell from top to bottom, and the front and rear end faces of each baffle abut against the front and rear end faces inside the shell respectively, the left and right length of each baffle is less than the distance between the left and right end faces of the shell, the higher ends of adjacent baffles are close to different left and right sides of the shell respectively, and the included angles between adjacent baffles and the horizontal plane are complementary.

[0010] Preferably, the thickness of the baffle is 3~8cm, and the left and right length is 3 / 4~5 / 6 of the distance between the left and right end faces of the shell.

[0011] Preferably, the front end face of the baffle is provided with an adjustment knob, the unit adjustment angle of the adjustment knob is 0.5°, and the maximum adjustment angle is not less than 20°.

[0012] Preferably, the upper surface of the baffle is provided with teardrop-shaped micro ribs, the height of the micro ribs is 0.1~0.3cm, the length is 0.5~1.0cm, the left-right spacing between the micro ribs is 5.0~10cm, and the front-back spacing is 1.0~5.0cm.

[0013] Preferably, the upper surface of the baffle is provided with longitudinal ribs, the height of the longitudinal ribs is 1~2cm, the length is equal to the left and right length of the baffle, the thickness is 0.3~1.0cm, and the front and rear distance between the longitudinal ribs is 10~20cm.

[0014] Preferably, the lower end face of the baffle is provided with a vibration device, and the vibration device is provided with frequency and amplitude regulators.

[0015] Preferably, the baffle is embedded with a heating device, which is an electric heating type, including an electric heating resistance wire and an electric power regulator; or the heating device is a hydrothermal type, including a capillary tube and a water temperature regulator.

[0016] Preferably, the outer wall of the shell is covered with a thermal insulation layer, the thermal conductivity of which is less than 0.055 W / (mK) and the thickness is 10~20 cm.

[0017] Preferably, the packing port is on the same side as the uppermost end of the uppermost baffle inside the shell, and the gas outlet is on the same side as the packing port, but closer to the left and right end faces of the shell than the packing port.

[0018] Preferably, the discharge port is on the same side as the higher end of the lowest baffle inside the shell, and a control valve is provided on the discharge port to adjust the discharge rate.

[0019] Beneficial effects: The present invention, through the design of staggered baffles, the addition of micro ribs and longitudinal ribs, and the addition of a vibration device, can effectively increase and flexibly adjust the residence time of reactants in the reactor, avoid the problem of large-scale accumulation of solid reactants in the reactor, enhance the heat exchange capacity of the reactor, improve the reaction rate and reaction conversion rate per unit time, and improve energy storage efficiency.

[0020] When the reactor is working, solid reactants enter from the packing port at the top and move downwards in an S-shape along the flow channel between the baffle and the shell. Gas flows in from the gas inlet at the bottom and moves upwards in an S-shape along the flow channel between the baffle and the shell, forming a countercurrent. In the flow reaction, the rate of reaction and the rate of reaction are controlled by changing the baffle angle and the temperature / power of the heating system according to actual needs. The large-scale accumulation of reactants is avoided by adjusting the vibration device. Attached Figure Description

[0021] Figure 1 This is a front view of the staggered baffle moving bed reactor of the present invention;

[0022] Figure 2 This is a left view of the staggered baffle moving bed reactor of the present invention;

[0023] Figure 3 This is a top view of the staggered baffle moving bed reactor of the present invention;

[0024] Figure 4 This is a schematic diagram of the baffle structure of the staggered baffle moving bed reactor of the present invention;

[0025] Figure 5 This is a schematic diagram of the heating device inside the baffle.

[0026] Figure 6 This is a schematic diagram of the vibration device on the lower end face of the baffle;

[0027] The numbers in the diagram represent the following: 1. Shell; 2. Baffle; 3. Gas inlet; 4. Gas outlet; 5. Packing port; 6. Discharge port; 7. Adjustment knob; 8. Micro ribs; 9. Longitudinal ribs; 10. Vibration device; 11. Heating device; 12. Insulation layer. Detailed Implementation

[0028] The present invention will be further described below with reference to the accompanying drawings and specific embodiments. Example

[0029] A staggered baffle moving bed reactor for thermochemical energy storage includes a shell 1, several staggered baffles 2, a gas inlet 3, a gas outlet 4, a packing port 5, a discharge port 6, and an insulation layer 12. The upper section of the reactor shell 1 is cubic, and the lower end is inverted trapezoidal, gradually tapering from top to bottom. The shell 1 is covered with an insulation layer 12. The baffles 2 are arranged inside the shell 1 from top to bottom. The front and rear ends of each baffle 2 abut against the front and rear ends of the shell 1, respectively. The left and right length of each baffle 2 is less than the distance between the left and right ends of the shell 1. The higher ends of adjacent baffles 2 are close to the left and right sides of the shell 1, and the angles between adjacent baffles 2 and the horizontal plane are complementary. An S-shaped flow channel is formed between the shell 1 and the baffles 2, through which both reactants and gases pass. The gas inlet 3 and the discharge port 6 are located at the bottom of the shell 1, and the gas outlet 4 and the packing port 5 are located at the top of the shell 1. The reactants and gases flow countercurrently.

[0030] The baffle 2 is made of a highly thermally conductive metal with a thickness of 3-8 cm and a length that is 3 / 4 to 5 / 6 of the distance between the left and right end faces of the shell 1. The front end face of the baffle 2 is provided with an adjustment knob 7, which has a unit adjustment angle of 0.5° and a maximum adjustment angle of not less than 20°.

[0031] The upper surface of the baffle 2 is provided with teardrop-shaped micro ribs 8. The micro ribs 8 are horizontally teardrop-shaped or approximately semi-elliptical spheres with a height of 0.1~0.3cm and a length of 0.5~1.0cm. The left-right spacing between the micro ribs 8 is 5.0~10cm, and the front-back spacing is 1.0~5.0cm.

[0032] The upper surface of the baffle 2 is provided with longitudinal ribs 9. The height of the longitudinal ribs 9 is 1~2cm, the length is equal to the left and right length of the baffle 2, the thickness is 0.3~1.0cm, and the front and rear distance between the longitudinal ribs 9 is 10~20cm.

[0033] The lower end face of the baffle 2 is provided with a vibration device 10, and the vibration device 10 is provided with frequency and amplitude regulators.

[0034] The baffle 2 is embedded with a heating device 11, which is an electric heating type, including an electric heating resistance wire and an electric power regulator; or the heating device 11 is a hydrothermal type, including a capillary tube and a water temperature regulator.

[0035] The outer wall of the shell 1 is covered with a thermal insulation layer 12, the thermal conductivity of which is less than 0.055 W / (mK) and the thickness is 10~20 cm. The shell 1 is made of high-temperature resistant metal or high-strength high-temperature resistant glass.

[0036] The packing port 5 is on the same side as the uppermost end of the baffle 2 inside the shell 1, and is at a certain distance from both the left and right sides of the shell 1; the gas outlet 4 is on the same side as the packing port 5, and is closer to the left and right end faces of the shell 1 than the packing port 5.

[0037] The discharge port 6 is on the same side as the higher end of the lowest baffle 2 inside the shell 1, and a control valve is provided on the discharge port 6 to adjust the discharge rate.

[0038] Specifically, such as Figures 1 to 6 As shown, the staggered baffle moving bed reactor for thermochemical energy storage includes a gas inlet 3, a discharge port 6, a reactor shell 1, an insulation layer 12, eight staggered baffles 2, a packing port 5, a gas outlet 4, several teardrop-shaped microribs 8 on the surface of the baffles 2, eight sets of vibration devices 10 located on the lower end face of the baffles 2, eight sets of heating devices 11 embedded in the baffles 2, four longitudinal ribs 9 on the surface of each baffle 2, and eight stepless angle adjustment knobs 7.

[0039] The left and right end faces of the shell 1 are about 4 m apart, the upper and lower end faces are about 2.5 m apart, and the front and rear end faces are about 0.5 m apart. It is covered with a 10 cm thick insulation layer 12.

[0040] The baffle 2 is 5 cm thick and 4 / 5 the width of the shell 1. Its width is basically the same as the thickness of the reactor. The baffle makes an angle θ of 4° with the horizontal plane. The front and rear end faces of the shell 1 and the baffle 2 are almost in close contact, forming a flow channel for reactants and gases.

[0041] The micro ribs 8 on the upper surface of the baffle 2 are horizontal teardrop-shaped, with a height of 0.2 cm and a length of 0.5 cm. The distance between the micro ribs 8 in the left-right direction is 5 cm, and the distance between them in the front-back direction is 2.0 cm.

[0042] The height of the longitudinal rib 9 on the upper end face of the baffle 2 is 1.5 cm, the thickness is 0.3 cm, the length is the same as the length of the baffle 2, and the distance between the longitudinal ribs 9 in the front and back directions is 10 cm.

[0043] The vibration device 10 is equipped with frequency and amplitude regulators.

[0044] The heating device 11 is an electric heating type, including an electric heating resistance wire and an electric power regulator.

[0045] More specifically, take the classic calcium hydroxide / calcium oxide particle heat storage / exothermic reaction in the field of thermochemical energy storage as an example (the principle is shown in equation (1)).

[0046] Equation (1)

[0047] When using the moving bed energy storage method described in this invention, before loading calcium hydroxide (Ca(OH)2) particles with a diameter of approximately 0.1~0.2 cm into the reactor, the heating device 11 is turned on, and the power regulator is adjusted to 550°C to preheat the reactor. Simultaneously, the gas inlet 3 is opened, and room temperature or preheated air is introduced at a flow rate of 0.5 m / s. All baffles 2 are adjusted to an angle of 3°. Once the reactor temperature reaches approximately 550°C, the calcium hydroxide particles enter the reactor through the packing port 5 at the top, fall into the baffles 2, and flow sequentially through baffles 2 at different heights, absorbing heat and undergoing a pyrolysis reaction. The resulting CaO product is discharged through the discharge port 6, completing the energy conversion—that is, converting thermal energy into chemical bond energy. The CaO product can be stored and, when heat is needed, hydrated with water vapor to release heat. Simultaneously, air flows upwards, forming a countercurrent with the calcium hydroxide particle flow, carrying the water vapor generated in the reaction, and is discharged through the top gas outlet 4. The descent speed of calcium hydroxide particles is controlled by changing the apparent velocity of the gas and the angle between the baffle 2 and the horizontal plane. The vibration device 10 is adjusted according to the actual situation to avoid the phenomenon of particles accumulating for a long time.

[0048] When using the moving bed energy release method described in this invention, calcium oxide (CaO) particles with a diameter of approximately 0.1~0.2 cm are added to the reactor through the packing port 5, and the angle of all baffles 2 is adjusted to 3°. The CaO particles then fall into the baffles 2 and flow through the baffles 2 at different heights from top to bottom. At the same time, the gas inlet 3 is opened, and room temperature steam is introduced at a flow rate of 0.5 m / s. The steam moves upward and forms a countercurrent with the flow of calcium oxide particles. When the calcium oxide particles encounter the steam, a hydration reaction occurs, releasing heat. The product Ca(OH)2 generated after the reaction is discharged through the discharge port 6, and the room temperature steam becomes high temperature steam, which is discharged through the top gas outlet 4 and sent to the energy demand side. The descent speed of the calcium oxide particles is controlled by changing the apparent gas velocity and the angle between the baffles 2 and the horizontal plane. The vibration device 10 is adjusted according to the actual situation to avoid the phenomenon of particles accumulating for a long time.

Claims

1. A staggered baffle moving bed reactor for thermochemical energy storage, characterized in that, The enclosure includes a shell (1), baffles (2), a gas inlet (3), a gas outlet (4), a packing port (5), and a discharge port (6). The gas inlet (3) and the discharge port (6) are located at the bottom of the shell (1), and the gas outlet (4) and the packing port (5) are located at the top of the shell (1). The baffles (2) are arranged inside the shell (1) from top to bottom. The front and rear ends of each baffle (2) abut against the front and rear ends of the shell (1). The left and right length of each baffle (2) is 3 / 4 to 5 / 6 of the distance between the left and right ends of the shell (1). The higher ends of adjacent baffles (2) are close to the left and right ends of the shell (1). The angles between the adjacent baffles (2) and the horizontal plane are complementary, forming an S-shaped flow channel; the upper end face of the baffle (2) is provided with teardrop-shaped micro ribs (8), the height of the micro ribs (8) is 0.1~0.3cm, the length is 0.5~1.0cm, the left and right distance between the micro ribs (8) is 5.0~10cm, and the front and back distance is 1.0~5.0cm; the upper end face of the baffle (2) is provided with longitudinal ribs (9), the height of the longitudinal ribs (9) is 1~2cm, the length is equal to the left and right length of the baffle (2), the thickness is 0.3~1.0cm, and the front and back distance between the longitudinal ribs (9) is 10~20cm.

2. The staggered baffle moving bed reactor for thermochemical energy storage according to claim 1, characterized in that, The thickness of the baffle (2) is 3~8cm.

3. The staggered baffle moving bed reactor for thermochemical energy storage according to claim 1, characterized in that, The front end face of the baffle (2) is provided with an adjustment knob (7), the unit adjustment angle of the adjustment knob (7) is 0.5°, and the maximum adjustment angle is not less than 20°.

4. The staggered baffle moving bed reactor for thermochemical energy storage according to claim 1, characterized in that, The lower end face of the baffle (2) is provided with a vibration device (10), and the vibration device (10) is provided with frequency and amplitude regulators.

5. A staggered baffle moving bed reactor for thermochemical energy storage according to claim 1, characterized in that, The baffle (2) is embedded with a heating device (11), which is an electric heating type, including an electric heating resistance wire and an electric power regulator; or the heating device (11) is a hydrothermal type, including a capillary tube and a water temperature regulator.

6. A staggered baffle moving bed reactor for thermochemical energy storage according to claim 1, characterized in that, The outer wall of the shell (1) is covered with a thermal insulation layer (12), the thermal conductivity of which is less than 0.055W / (mK) and the thickness is 10~20cm.

7. A staggered baffle moving bed reactor for thermochemical energy storage according to claim 1, characterized in that, The packing port (5) is on the same side as the uppermost baffle (2) inside the shell (1), and the gas outlet (4) is on the same side as the packing port (5) and is closer to the left and right end faces of the shell (1) than the packing port (5).

8. A staggered baffle moving bed reactor for thermochemical energy storage according to claim 1, characterized in that, The discharge port (6) is on the same side as the higher end of the lowest baffle (2) inside the shell (1), and a control valve is provided on the discharge port (6) to adjust the discharge rate.

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