CN107717355B

CN107717355B - Reactor microchannel manufacturing method based on laser secondary machining

Info

Publication number: CN107717355B
Application number: CN201711101069.3A
Authority: CN
Inventors: 褚旭阳; 全学军; 周伟; 张利; 曾湘衡; 陈佑豪
Original assignee: Xiamen University
Current assignee: Xiamen University
Priority date: 2017-11-10
Filing date: 2017-11-10
Publication date: 2020-02-14
Anticipated expiration: 2037-11-10
Also published as: CN107717355A

Abstract

A method for manufacturing a reactor microchannel based on laser secondary processing relates to the processing of the reactor microchannel. 1) Preparing a microchannel array on a catalyst support plate; 2) cleaning the catalyst carrier plate to remove the residual working solution; placing a catalyst carrier plate on a laser processing platform, and focusing laser at the starting end of a first micro-channel; 4) controlling the motion track of the laser processing platform, and carrying out laser processing on the bottom surface or the inclined side wall of the first microchannel; 5) and (4) adjusting the laser position to the starting end of the second micro-channel, and repeating the step 4) until all the micro-channel arrays are processed. The micro-channel appearance structure is manufactured by utilizing an efficient processing means, and then the surface structure performance of the micro-channel is enhanced by utilizing laser secondary processing. The organic combination of the two processing procedures not only greatly improves the processing efficiency of the micro-channel structure, but also improves the catalyst adhesion property on the surface of the micro-channel, thereby greatly improving the hydrogen production performance of the reactor.

Description

Reactor microchannel manufacturing method based on laser secondary machining

Technical Field

The invention relates to the processing of a reactor microchannel, in particular to a method for manufacturing the reactor microchannel based on laser secondary processing.

Background

Under the large background that the shortage of energy resources and the environmental pollution are becoming serious, the negative effects of the automobile on the environment are reduced, the excessive dependence of the automobile on non-renewable energy sources is reduced, and the consensus is achieved on the global scale. The vigorous development of hydrogen-powered fuel cell vehicles is an rare opportunity for the development of the automotive industry and for the development of alternative energy sources. Because the on-board on-site hydrogen production system must meet the special requirements of small size, light weight, low manufacturing cost and realization of high catalytic reaction rate in a limited reaction volume, it is impractical to miniaturize the fuel catalytic reforming equipment of conventional dimensions, and the hydrogen production reactor with a microchannel structure is a trend for future development.

The catalytic reaction rate and the catalytic conversion rate of the microchannel reactor are mainly influenced by a catalytic reaction carrier (consisting of a catalyst coating loaded in a carrier plate). The carrier plate is usually processed by processing methods such as precision milling, laser, chemical etching, linear cutting and the like, and the micro-channel surface microstructures manufactured by different processing methods are different, and the surface structures can influence the adhesion performance of a catalyst and the flow performance of a medium in the micro-channel and have great influence on the efficiency and the service life of a reactor. Some researchers have attempted to modify the microchannel surface structure to improve reactor performance. For example, in the document microstuctured reactors for catalytic reactions (WOS: 000233890900002; ISSN: 0920) -5861, the authors Kiwi-Minsker, L and Renken, A designed a two-channel micro-structured reactor made of stainless steel containing aluminum, and formed a 5 μm thick alumina film on the surface, which greatly improved the adhesion between the catalyst layer and the microchannel wall, but this method was only suitable for aluminum-based micro-channel surface fabrication, and the surface micro-film was not controllable, and the application range and effect were limited.

Disclosure of Invention

The invention aims to provide a reactor micro-channel manufacturing method based on laser secondary processing, which is used for manufacturing a microstructure with a certain depth by carrying out secondary processing on the surface of an original micro-channel by adopting a laser processing method so as to increase the specific surface area of the micro-channel and improve the hydrogen production performance of a reactor.

The invention comprises the following steps:

1) preparing a microchannel array on a catalyst support plate;

in step 1), the preparation of the microchannel array on the catalyst carrier plate can adopt methods such as linear cutting, milling, chemical etching and the like, and the cross section of the microchannel can be in a shape of rectangle, triangle and the like.

2) Cleaning the catalyst carrier plate to remove the residual working solution;

3) placing a catalyst carrier plate on a laser processing platform, and focusing laser at the starting end of a first micro-channel;

4) controlling the motion track of the laser processing platform, and carrying out laser processing on the bottom surface or the inclined side wall of the first microchannel;

in step 4), the laser processing can control the processing depth by controlling the power and the feeding speed of the laser, the processing track is similar to regular shapes such as zigzag and Chinese character tian, and the bottom surface of the micro-channel is divided into a plurality of independent areas until the surface of the first micro-channel is processed.

5) And (4) adjusting the laser position to the starting end of the second micro-channel, and repeating the step 4) until all the micro-channel arrays are processed.

The method for processing the micro-channel by the linear cutting, milling, chemical etching and the like has high processing speed, can easily obtain an ideal micro-channel section shape, and has high production efficiency. However, these processing methods have difficulty in controlling the surface structure of the microchannel, resulting in poor catalyst adhesion to the surface of the microchannel. The laser processing light spots can be focused to the micron level, so that a regular array structure can be easily processed on the surface of the micro-channel, the surface area of the channel is increased, and the catalyst attachment amount is increased. Meanwhile, through designing a laser processing path, independent areas are divided between the bottom surfaces of the micro-channels, and fine protrusions are arranged on the edges of each area to serve as barriers, so that the resistance of airflow passing through can be increased, the retention time of the airflow on a catalyst carrier plate is prolonged, and the catalytic performance of the reactor is improved. In addition, the protrusions can be used as barriers to prevent a part of the catalyst from being washed away by airflow, and the service life of the reactor is prolonged.

The method firstly adopts the methods of linear cutting, milling, chemical etching and the like to manufacture the microchannel array with certain width and depth on the catalyst carrier plate. Then the carrier plate is placed on a laser processing platform, the bottom surface of the microchannel is processed by laser for the second time, and a microstructure with certain depth and width is processed on the bottom surface of the original microchannel so as to enlarge the specific surface area of the microchannel, improve the adhesion property of the microchannel catalyst and improve the hydrogen production capacity of the microreactor.

The method firstly utilizes an efficient processing means to manufacture the appearance structure of the micro-channel, and then utilizes laser secondary processing to enhance the surface structure performance of the micro-channel. The organic combination of the two processing procedures not only greatly improves the processing efficiency of the micro-channel structure, but also improves the catalyst adhesion property on the surface of the micro-channel, thereby greatly improving the hydrogen production performance of the reactor.

Drawings

Fig. 1 shows a trace of a wire electrode for fine wire electric discharge machining.

FIG. 2 is a cross-sectional view of a microchannel after a single pass.

Fig. 3 is a view showing a secondary process of the micro channel after the wire cutting process using a laser.

Fig. 4 is a schematic view of the fine wire electric discharge machining and the laser hybrid machining.

Detailed Description

The embodiments of the present invention will be described in detail below with reference to the accompanying drawings: the present embodiment is implemented on the premise of the technical solution of the present invention, and a detailed implementation manner and a specific operation process are given, but the protection scope of the present invention is not limited to the following embodiments.

The specific implementation steps are as follows:

① A copper plate is used as a catalyst carrier plate, and an electric spark machine is used to process a rectangular micro-channel array as shown in figure 1,

② soaking the catalyst carrier plate obtained in step ① in dilute nitric acid with a certain concentration for a period of time to remove the cutting fluid residue.

③ the carrier sheet cleaned in step ② was processed using a laser marker as shown in fig. 2 and 3, the laser power was selected and the processing was performed according to zigzag-shaped trajectories at a predetermined feed rate, the width of each processing path was 5 μm, and the processing was repeated 10 times.

④ the catalyst is loaded on the carrier plate by multiple dipping and applied to the micro-reactor for hydrogen production by plate methanol steam reforming, the schematic diagram after micro electrospark wire-electrode cutting and laser composite processing is shown in figure 4.

In fig. 1 to 4, a mark L is a wire electrode running track, a is a bottom surface of a micro-channel, M is a laser, S is a focal point of laser focusing, N is a laser processing track, and Q is a micro-channel.

Claims

1. A method for manufacturing a reactor microchannel based on laser secondary processing is characterized by comprising the following steps:

1) preparing a microchannel array on a catalyst support plate;

the preparation of the micro-channel array on the catalyst carrier plate adopts the methods of linear cutting, milling and chemical etching;

2) cleaning the catalyst carrier plate to remove the residual working solution;

4) controlling the motion track of the laser processing platform, and carrying out laser processing on the bottom surface or the inclined side wall of the first microchannel; the laser processing is to control the processing depth by controlling the power and the feeding speed of the laser, the processing track is in a zigzag or zigzag regular shape, and the bottom surface of the micro-channel is divided into a plurality of independent areas until the surface of the first micro-channel is processed;

2. The method for manufacturing a reactor microchannel based on laser secondary machining according to claim 1, wherein in the step 1), the cross section of the microchannel has a rectangular and triangular shape.