Catalytic reactor for flow velocity layering in microchannel
By setting up the microchannel structure of reverse and forward Tesla valves in the catalytic reactor, the problems of reduced conversion efficiency and increased flow resistance caused by increased flow velocity are solved, and efficient contact between gas and catalyst and smooth flow are achieved.
Patent Information
- Application Number
- CN202422526942.5
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-10-18
- Publication Date
- 2025-07-22
- Estimated Expiration
- 2034-10-18
AI Technical Summary
When the flow rate of existing catalytic reactors increases, pollutant conversion efficiency decreases and flow resistance increases, making it difficult to find a balance between increasing the incoming flow contact with the catalyst and reducing the system fluid resistance.
A catalytic reactor with a layered flow rate in the microchannel is designed, including an inlet section, an expansion section, a catalyst, a shrinkage section and an outlet section. The microchannel is arranged radially along the catalyst, and the reverse Tesla valve and forward Tesla valve are arranged internally interlaced or sequentially to adjust the gas flow rate and catalyst contact time.
While ensuring the smoothness of gas flow, it increases the effective contact time between gas and catalyst, improves pollutant conversion efficiency and reduces the system fluid resistance.
Smart Images
Figure CN223128001U_ABST
Abstract
Description
Technical Field
[0001] The utility model belongs to the technical field of energy environment equipment, and particularly relates to a catalytic reactor with stratified flow velocity in a microchannel. Background Art
[0002] In a catalytic converter system, a honeycomb type, plate type or corrugated plate type catalytic reaction section is often arranged in a pipeline to increase the contact area between the oncoming flow and the catalytic surface. That is, in the reactor section, a dense microchannel is arranged (the evaluation parameter is the mesh number: the number of holes per square inch), and a catalyst is coated on the inner surface of the microchannel. When the oncoming flow gas flows through each microchannel, it can contact the catalyst, and then harmful pollutants such as HC (hydrocarbon), CO (carbon monoxide), NOx (nitrogen oxides), etc. are catalytically converted into harmless gas components. As the flow velocity increases, the pollutant conversion efficiency often decreases. Moreover, for a honeycomb type, plate type or corrugated plate type reactor, when the oncoming flow (inlet) velocity increases, the flow resistance of the catalytic reactor will be greatly increased, thereby increasing the system energy consumption. Therefore, reducing the flow velocity can increase the contact time between the oncoming flow gas and the catalyst; on the other hand, too slow a flow velocity will affect the exhaust performance of an engine or other types of chemical processes, and thus affect the system energy consumption. Moreover, the exhaust velocity is determined by the operating conditions of the engine itself (such as load and speed) and the exhaust system (such as pipe diameter), and cannot be subjectively controlled. The existing microchannels of the reactor are uniformly arranged in the cross-sectional direction and are regular straight channels in the length direction. Such a design cannot well solve the contradiction between increasing the effective contact between the oncoming flow and the catalyst and reducing the fluid resistance of the system. Summary of the Utility Model
[0003] Aiming at the above-mentioned disadvantages of the prior art, the utility model provides a catalytic reactor with stratified flow velocity in a microchannel.
[0004] To achieve the above object, the technical solution adopted by the utility model is as follows: a catalytic reactor with stratified flow velocity in a microchannel, which sequentially includes an inlet section, an expansion section, a catalytic converter, a contraction section and an outlet section according to the gas flow direction;
[0005] A microchannel is arranged in the catalytic converter, and the microchannel is arranged radially in the catalytic converter; a reverse Tesla valve and a forward Tesla valve are arranged inside the microchannel; the number ratio of the forward Tesla valve to the reverse Tesla valve is (0.5 - 2):1.
[0006] As a preferred implementation scheme of the utility model, the reverse Tesla valve and the forward Tesla valve inside the microchannel are arranged crosswise.
[0007] More preferably, in the direction of gas flow, a reverse Tesla valve is arranged at the front end inside the microchannel, and a forward Tesla valve is arranged at the rear end. The use of the reverse Tesla valve at the front end of the present invention slows down the flow rate at the front end, increasing the effective contact time between the gas and the catalyst; the use of the forward Tesla valve at the rear end speeds up the flow rate, thus solving the contradiction between increasing the effective contact between the incoming flow and the catalyst and reducing the fluid resistance of the system. As the optimal solution of the present invention, arranging a reverse Tesla valve at the front end and a forward Tesla valve at the rear end ensures the gas flow rate while achieving the highest catalytic efficiency for the tail gas.
[0008] As a preferred embodiment of the present invention, the cross-section of the microchannel is circular, square or hexagonal.
[0009] As a preferred embodiment of the present invention, the inner surface of the microchannel, the surfaces of the reverse Tesla valve and the forward Tesla valve are coated with a catalyst, and the catalyst is a common catalyst in the art. An appropriate existing catalyst is selected according to the type of tail gas. For example: for CO and HC gases, common catalysts are Pt, Pd, Rh or a mixture of the three. For NO x , the commonly used NH3-SCR (ammonia-driven selective catalytic reduction) technology is used for reduction, and the catalysts are vanadium oxides (such as V2O5-WO3 / TiO2, etc.) or zeolite molecular sieves (commonly used Cu-SSZ-13), etc.
[0010] As a preferred embodiment of the present invention, the mesh number of the catalytic converter is 300 - 600 pores per square inch, and the size of the microchannel is on the order of 1 mm.
[0011] Compared with the prior art, the beneficial effects of the present invention are as follows: the present invention arranges the reverse Tesla valve and the forward Tesla valve inside the microchannel to achieve the purpose of local decomposition of the flow field, and can coordinate the contradiction between the overall pollutant conversion efficiency and the exhaust fluidity. Description of the Drawings
[0012] Figure 1 It is a schematic diagram of a catalytic reactor with flow velocity stratification inside a microchannel.
[0013] Figure 2 It is a schematic diagram of the microchannel and the inside of the microchannel in the catalytic reactor with flow velocity stratification inside the microchannel; (a) is a schematic diagram of the internal microchannel of the catalytic reactor with flow velocity stratification inside the microchannel; (b) is a schematic diagram of the internal structure with a reverse Tesla valve and a forward Tesla valve arranged inside the microchannel in Example 1; (b) is a schematic diagram of the internal structure with a reverse Tesla valve and a forward Tesla valve arranged inside the microchannel in Example 2.
[0014] Figure 3 It is a cross-sectional view of a microchannel with a circular cross-section. The left figure is a cross-sectional view of A - A, and the right figure is a cross-sectional view of B - B.
[0015] In the figure: 1 - inlet section, 2 - expansion section, 3 - catalytic converter, 4 - contraction section, 5 - outlet section. Specific embodiments
[0016] To better illustrate the purpose, technical solution and advantages of the present invention, the present invention will be further described below in conjunction with specific embodiments.
[0017] The overall scheme of the present invention is as Figure 1 shown. The inlet section 1 of the catalytic reactor with flow velocity stratification in the microchannel is connected to the engine exhaust outlet (or the upstream of the incoming material in the chemical system), and the outlet section 5 is connected to subsequent exhaust devices (such as mufflers or other post-treatment devices, etc.) or directly discharged to the atmosphere. The entire tail gas catalytic reactor that increases the effective contact between the tail gas and the catalyst includes the following sections in sequence from the incoming flow inlet to the outlet: inlet section 1, expansion section 2, catalytic converter 3, contraction section 4 and outlet section 5. The incoming flow carries pollutants (such as HC, CO, NO x ) and enters the inlet section 1 and the expansion section 2 in sequence, and then enters the microchannels densely arranged in the reactor, where it is catalytically converted into harmless products in the microchannels, and finally passes through the contraction section 4 and the outlet section 5 in sequence and is discharged.
[0018] Embodiment 1
[0019] As Figure 1 shown, a catalytic reactor with flow velocity stratification in the microchannel includes an inlet section 1, an expansion section 2, a catalytic converter 3, a contraction section 4 and an outlet section 5 in sequence according to the gas flow direction.
[0020] In this embodiment, the catalytic converter 1 is a cylinder with openings at both ends. The microchannels are arranged radially in the catalytic converter 1, and the length of the microchannels is the same as that of the catalytic converter 1; the microchannels are evenly distributed on the cross-section of the catalytic converter 1. The number of microchannels of the catalytic converter 1 is 300 pores per square inch, and the size of the microchannels is on the order of 1 mm; the inner surface of the microchannels and the surfaces of the reverse Tesla valve and the forward Tesla valve are coated with Pt catalyst.
[0021] As Figure 2As shown in (b), in the gas flow direction, a reverse Tesla valve is provided at the front end inside the microchannel 1, and a forward Tesla valve is provided at the rear end. The length of the front end inside the microchannel 1 is 50%-60% of the microchannel length. The quantity ratio of the forward Tesla valve to the reverse Tesla valve is 1:1, and the total quantity can be installed according to actual needs. In the present utility model, the reverse Tesla valve is used at the front end to slow down the flow rate at the front end and increase the effective contact time between the gas and the catalyst; the forward Tesla valve is used at the rear end to accelerate the flow rate, thereby solving the contradiction between increasing the effective contact between the incoming flow and the catalyst and reducing the fluid resistance of the system. As the optimal solution of the present utility model, setting a reverse Tesla valve at the front end and a forward Tesla valve at the rear end can maximize the catalytic efficiency of the tail gas while ensuring the gas flow rate.
[0022] As Figure 3 shown, both the reverse Tesla valve and the forward Tesla valve are formed by fixing baffles on the inner wall of the microchannel 1 to form a reverse Tesla valve or a forward Tesla valve.
[0023] Embodiment 2
[0024] As Figure 1 shown, a catalytic reactor with stratified flow velocity in a microchannel sequentially includes an inlet section 1, an expansion section 2, a catalytic converter 3, a contraction section 4, and an outlet section 5 in the gas flow direction.
[0025] In this embodiment, the catalytic converter 1 is a cylinder with openings at both ends. The microchannel is arranged radially in the catalytic converter 1; the microchannels are evenly distributed on the cross-section of the catalytic converter 1; the number of microchannels of the catalytic converter 1 is 600 pores per square inch, and the size of the microchannel is on the order of 1 mm. The inner surface of the microchannel and the surfaces of the reverse Tesla valve and the forward Tesla valve are coated with a Pd catalyst.
[0026] In this embodiment, as Figure 2 (c) shown, in the gas flow direction, the reverse Tesla valve and the forward Tesla valve provided inside the microchannel are arranged crosswise, and the quantity ratio of the forward Tesla valve to the reverse Tesla valve is 0.5:1. The total quantity can be installed according to actual needs.
[0027] Both the reverse Tesla valve and the forward Tesla valve are formed by fixing baffles of different sizes on the inner wall of the microchannel 1 to form a reverse Tesla valve or a forward Tesla valve.
[0028] The present utility model increases the contact and reaction time between the air flow and the catalyst and improves the conversion efficiency of pollutants (or energy) by providing a microchannel equipped with a reverse Tesla valve and a forward Tesla valve without affecting the exhaust and reducing the smoothness of gas flow.
[0029] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present utility model rather than to limit the protection scope of the present utility model. Although the present utility model has been described in detail with reference to the preferred embodiments, those of ordinary skill in the art should understand that the technical solutions of the present utility model can be modified or equivalently replaced without departing from the essence and scope of the technical solutions of the present utility model.
Claims
1. A catalytic reactor with stratified flow velocity in a microchannel, characterized in that, According to the gas flow direction, it includes an inlet section, an expansion section, a catalyst, a contraction section and an outlet section in sequence; A microchannel is arranged in the catalyst, and the microchannel is arranged in the radial direction of the catalyst; a reverse Tesla valve and a forward Tesla valve are arranged inside the microchannel; the number ratio of the forward Tesla valve to the reverse Tesla valve is (0.5-2):
1.
2. The catalytic reactor with stratified flow velocity in the microchannel according to claim 1, characterized in that The reverse Tesla valve and the forward Tesla valve arranged inside the microchannel are arranged crosswise.
3. The catalytic reactor with stratified flow velocity in the microchannel according to claim 2, wherein According to the gas flow direction, a reverse Tesla valve is arranged at the front end of the microchannel, and a forward Tesla valve is arranged at the rear end.
4. The catalytic reactor with stratified flow velocity in the microchannel according to claim 1, characterized in that, The cross section of the microchannel is circular, square or hexagonal.
5. The catalytic reactor with stratified flow velocity in the microchannel according to claim 1, wherein The inner surface of the microchannel, the surfaces of the reverse Tesla valve and the forward Tesla valve are coated with a catalyst.
6. The catalytic reactor with stratified flow velocity in the microchannel according to claim 1, characterized in that, The mesh number of the catalyst is 300-600 holes / square inch, and the size of the microchannel is on the order of 1 mm.
Citation Information
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