An electrolytic machining device and machining method for a PCHE heat exchanger plate

Abstract

The present invention discloses an electrolytic machining device and method for a PCHE heat exchanger plate, comprising a three-dimensional moving platform, a cathode fixing plate, an electrolyte circulation device and a pulse power supply; the plate to be machined is arranged as an anode plate on the top of the three-dimensional moving platform, multiple cathode plate groups are fixedly arranged side by side on the cathode fixing plate, and the cathode plate groups are located on the top of the anode plate. The outlet of the electrolyte circulation device is connected to the cathode fixing plate, the cathode of the pulse power supply is connected to the cathode plate groups, the anode of the pulse power supply is connected to the plate to be machined, and an electrolyte recovery tank is arranged at the bottom of the anode plate. The electrolyte recovery tank is connected to the inlet of the electrolyte circulation device. This device uses electrolytic machining to machine the flow channels on the PCHE plate instead of chemical etching, avoiding the use of expensive etching agents and photoresist, thereby reducing the processing cost.

Description

Technical Field

[0001] The present invention relates to the technical field of heat exchange devices, and particularly to an electrolytic processing device and a processing method for a printed circuit heat exchanger (PCHE) plate Background Art

[0002] A printed circuit heat exchanger (PCHE) belongs to the category of microchannel plate heat exchangers. PCHEs have the advantages of being structurally compact, high-temperature resistant, high-pressure resistant, safe and reliable, etc., and are widely used in fields such as refrigeration and air conditioning, oil and gas, nuclear industry, chemical industry, and power industry

[0003] Currently, the common PCHE heat exchanger plates are processed by chemical etching. High-quality chemical etching agents need to be imported, and photoresist needs to be applied on the plates during etching processing, and the required patterns are etched through lithography technology. Tiny voids are likely to occur during the application and lithography processes, so the rejection rate is relatively high. In some small processing enterprises, the rejection rate of etched plates can reach 50%. Various factors make the processing of plates by etching expensive. Especially for the application environment of power plants with a huge heat exchange capacity, the high price of PCHE heat exchangers greatly increases their operating costs

[0004] Therefore, it is necessary to develop a processing method for PCHE heat exchanger plates to reduce the manufacturing cost of PCHE heat exchanger plates and reduce the defect rate of PCHE heat exchanger plates during the manufacturing process Summary of the Invention

[0005] In order to solve the problems existing in the chemical etching processing of PCHE plates, the purpose of the present invention is to provide an electrolytic processing device and a processing method for PCHE heat exchanger plates. The electrolytic processing is used to process the flow channels on the PCHE plates instead of chemical etching, avoiding the use of expensive etching agents and photoresist, thereby reducing the processing cost

[0006] The present invention is realized through the following technical solutions

[0007] An electrolytic processing device for a PCHE heat exchanger plate includes a three-dimensional moving platform, a cathode fixing plate, an electrolyte circulation device, and a pulse power supply

[0008] The plate to be processed is set as the anode plate on the top of the three-dimensional moving platform. A plurality of cathode plate groups are fixedly arranged side by side on the cathode fixing plate, and the cathode plate groups are located on the top of the anode plate. The outlet of the electrolyte circulation device is connected to the cathode fixing plate, the cathode of the pulse power supply is connected to the cathode plate groups, the anode of the pulse power supply is connected to the plate to be processed, and an electrolyte recovery tank is arranged at the bottom of the anode plate. The electrolyte recovery tank is connected to the inlet of the electrolyte circulation device

[0009] Preferably, an electrolyte buffer tank is provided at the top of the cathode fixing plate. The outlet of the electrolyte circulation device is connected to the electrolyte buffer tank. A plurality of cathode plate groups are fixed to the bottom surface of the cathode fixing plate, and the cathode plate groups are connected to the pulse power supply through a loading controller.

[0010] Preferably, adjacent two cathode plate groups are insulated and connected.

[0011] Preferably, the cathode plate group includes a cathode plate, an insulating plate piece and a cathode electrode;

[0012] A plurality of cathode plates and insulating plate pieces are arranged vertically and alternately. The cathode electrode is located at the top of the cathode plate and is electrically connected. The cathode electrode is hermetically connected to the cathode fixing plate, and the connection end of the cathode electrode passes through the electrolyte buffer tank and is connected to the loading controller.

[0013] Preferably, an electrolyte channel is provided in the insulating plate piece. The upper end of the electrolyte channel communicates with the electrolyte buffer tank, and the lower end of the electrolyte channel faces the anode plate piece.

[0014] Preferably, the arrangement mode of the cathode plates is the same as the structure of the flow-through grooves on the anode plate piece.

[0015] Preferably, the electrolyte circulation device includes an electrolyte storage tank, an electrolyte pump and an electrolyte filter. The inlet of the electrolyte storage tank communicates with the outlet of the electrolyte recovery tank. The outlet of the electrolyte storage tank is connected to a filter box. An electrolyte filter is provided in the filter box. The outlet of the filter box is connected to the electrolyte pump, and the electrolyte pump communicates with the electrolyte buffer tank.

[0016] Preferably, an electrolyte cooler and an electrolyte heater are provided in the electrolyte storage tank.

[0017] Preferably, a temperature sensor and a pressure sensor are provided in the electrolyte buffer tank.

[0018] A method for an electrolytic processing device of a PCHE heat exchanger plate piece includes the following steps:

[0019] Step 1: Use a stainless steel plate as the anode plate and install it on a three-dimensional moving platform. A plurality of cathode plate groups are fixed to the bottom of the cathode fixing plate;

[0020] Step 2: Prepare the electrolyte and set the electrolysis parameters and machining feed parameters;

[0021] Step 3: According to the parameters set in Step 2, use a plurality of cathode plate groups to process the anode plate in sequence until the processing of the anode plate is completed.

[0022] Compared with the prior art, the present invention has the following beneficial technical effects:

[0023] An electrolytic processing device for a PCHE heat exchanger plate provided by the present invention uses the plate to be processed as the anode. Through discharging with the cathode, an electrochemical reaction occurs at the anode, causing the anode material to become ions and be "cut off". The cathode is made to have the same flow channel distribution as the PCHE plate, and the cross-section of the cathode plate is the same as that of the flow channel. It is formed in one step during processing, with a fast processing speed. Compared with the existing chemical etching processing method, there is no need to apply photoresist on the plate, and there is no problem of defective plates caused by pores in the photoresist film, greatly improving the yield. At the same time, the electrolyte can use the most common NaCl solution, without the need to use expensive etching agents, reducing the cost of the PCHE heat exchanger plate. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 It is a structural schematic diagram of the electrolytic processing device for the PCHE heat exchanger plate of the present invention;

[0025] Figure 2 It is a schematic cross-sectional structure diagram of the cathode plate group of the present invention;

[0026] Figure 3 It is a schematic cross-sectional structure diagram of the juxtaposed cathode group of the present invention.

[0027] In the figure: 1. Anode plate, 2. Cathode plate group, 3. Electrolyte buffer tank, 4. Temperature sensor, 5. Pressure sensor, 6. Electrolyte recovery tank, 7. Electrolyte filter, 8. Electrolyte cooler, 9. Electrolyte storage tank, 10. PH value monitoring device, 11. Electrolyte concentration monitoring device, 12. Electrolyte pump, 13. Pulse power supply, 14. Loading controller, 15. Electrolyte heater, 16. Lifting platform, 17. X-axis feed control system, 18. Y-axis feed control system, 19. Z-axis feed control system, 2-1 Cathode plate, 2-2 Insulating plate, 2-3 Cathode electrode, 2-4 Electrolyte hole, 2-5 Inter-stage insulating plate. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0028] The following further describes the present invention in detail with reference to the drawings, which is an explanation rather than a limitation of the present invention.

[0029] Refer to Figures 1-3 , an electrolytic processing device for a PCHE heat exchanger plate, including a three-dimensional moving platform, a cathode fixing plate, an electrolyte circulation device, and a pulse power supply.

[0030] The sheet to be processed is arranged as an anode sheet on the top of a three-dimensional moving platform. A plurality of cathode plate groups 2 are fixedly arranged side by side on a cathode fixing plate, and the cathode plate groups are located on the top of the anode sheet. The outlet of the electrolyte circulation device is connected to the cathode fixing plate. The cathode of the pulse power supply is connected to the cathode plate groups, and the anode of the pulse power supply is connected to the sheet to be processed. An electrolyte recovery tank 6 is arranged at the bottom of the anode sheet, and the electrolyte recovery tank 6 is connected to the inlet of the electrolyte circulation device.

[0031] An electrolyte buffer tank 3 is arranged on the top of the cathode fixing plate. The outlet of the electrolyte circulation device is connected to the electrolyte buffer tank 3. A fixing device is arranged at the bottom of the cathode fixing plate. A plurality of cathode plate groups are fixedly arranged on the bottom surface of the cathode fixing plate. Each cathode plate group is respectively connected to the pulse power supply through a loading controller 14. A temperature sensor 4 and a pressure sensor 5 are arranged in the electrolyte buffer tank 3 for monitoring the temperature and pressure of the electrolyte in the electrolyte buffer tank 3.

[0032] See Figure 2 and Figure 3 , Figure 2 is a schematic structural diagram of a single cathode plate group, Figure 3 is a schematic diagram of the side-by-side arrangement of a plurality of cathode plate groups. The plurality of cathode plate groups are arranged in sequence along the processing direction. An inter-stage insulating plate 2-5 is arranged between two adjacent cathode plate groups 2. The cathode plate group 2 includes a cathode plate 2-1, an insulating sheet 2-2, and a cathode electrode 2-3. A plurality of cathode plates 2-1 and insulating sheets 2-2 are arranged vertically and alternately. The cathode electrode 2-3 is located on the top of the cathode plate 2-1 and is electrically connected. The cathode electrode 2-3 is fixedly sealed on the cathode fixing plate. The connection end of the cathode electrode 2-3 passes through the electrolyte buffer tank 3 and is connected to the loading controller 14. An electrolyte hole 2-4 is arranged on the insulating sheet 2-2. The upper end of the electrolyte hole 2-4 passes through the cathode electrode and communicates with the electrolyte buffer tank 3. The lower end of the electrolyte hole 2-4 faces the anode sheet.

[0033] The arrangement mode of the cathode plates 2-1 is the same as the structure of the flow-through grooves on the anode sheet, and the distance between the lower end of the cathode plates 2-1 and the anode sheet is less than the distance between the insulating sheets 2-2 and the anode sheet.

[0034] The electrolyte circulation device includes an electrolyte storage tank 9, an electrolyte pump 12, and an electrolyte filter 7. The inlet of the electrolyte storage tank 9 is communicated with the outlet of the electrolyte recovery tank 6. The outlet of the electrolyte storage tank 9 is connected to a filter box. The electrolyte filter 7 is arranged in the filter box. The outlet of the filter box is connected to the electrolyte pump 12. The electrolyte pump 12 is communicated with the electrolyte buffer tank 3.

[0035] An electrolyte cooler 8 and an electrolyte heater 15 are provided in the electrolyte storage tank 9. At the initial moment, the temperature of the electrolyte is the ambient temperature and is heated to the working temperature by the electrolyte heater 15. During the entire processing stage, the electrolyte heater 15 is in a state of stopping heating. During the processing, the temperature of the electrolyte will rise due to repeated circulation, and the electrolyte cooler 8 is used to cool down the electrolyte to keep it constant at the working temperature. A pH value monitoring device 10 and an electrolyte concentration monitoring device 11 are also provided in the filtration tank to monitor the state of the electrolyte.

[0036] The three-dimensional moving platform is an XYZ three-axis motion platform. The anode plate is fixed on the lifting table 16 of the three-dimensional moving platform. An x-axis feed control system 16, a y-axis feed control system 17, and a z-axis feed control system 18 are provided in the three-dimensional moving platform. The cathode fixing plate is suspended directly above the anode plate through a fixing frame.

[0037] In another embodiment, the moving platform is a two-dimensional moving platform. The cathode fixing plate is connected to a lifting device, and the descending rate of the cathode fixing plate is controlled by the lifting device. The anode plate moves horizontally through the moving platform.

[0038] Taking a stainless steel plate as an example, the processing method of an electrolytic processing device for a PCHE heat exchanger plate provided by the present invention will be described in detail below.

[0039] A processing method of an electrolytic processing device for a PCHE heat exchanger plate includes the following steps:

[0040] Step 1: Use the stainless steel plate as the anode plate and install it on the three-dimensional moving platform. A plurality of cathode plate groups are fixed to the bottom of the cathode fixing plate.

[0041] Step 2: Prepare the electrolyte, 8% NaCl, with a pH value of 7.8 - 8.2. Set the electrolysis parameters: the current density is 32 - 36 A / cm2, the cathode feed rate is controlled at 0.6 - 0.8 mm / min, the electrode liquid pressure is controlled at 0.6 - 0.8 MPa, the electrolyte temperature is controlled between 32 - 36 °C, and the processing gap is controlled at 0.5 - 0.8 mm.

[0042] Step 3: Perform electrolytic corrosion processing on the anode plate by multiple cathode plate groups in sequence.

[0043] Taking the PCHE semi-circular channel with a diameter of 1.5 mm and a single-channel length of 1000 mm as an example, the loading controller is used to control the number of cathode plates loaded each time between 5 and 8. Before loading, ensure that the electrolyte flow field has been established. The single loading time is controlled between 4 and 8 s. After each single loading is completed, the loading controller needs to be used to switch to the next cathode plate group to complete the electrolytic machining of all channels in one round. After that, the anode plate lifting table gives a certain feed under the control of the z-axis feed control system, and then the next round of loading is cycled until the entire anode plate is completely machined.

[0044] The principle of the machining method of the electrolytic machining device of the present invention is that the plate to be machined is used as the anode. Through the discharge between the anode and the cathode, an electrochemical reaction occurs on the anode, causing the anode material to become ions and be "cut off". The shape finally machined from the anode material is the same as the shape of the cathode electrode. During the electrolytic machining process, no mechanical machining residual stress is generated, nor is machining thermal stress generated. The machining accuracy is relatively high, reaching the μm level. At the same time, the machining speed is relatively fast, much higher than that of electrical discharge machining. In addition, electrolytic machining does not require applying photoresist on the plate, and the scrap rate is low. At the same time, the electrolyte mostly uses very cheap NaCl solution, so there is a large room for cost reduction. Using electrolytic machining to replace chemical etching to machine the flow channels on the PCHE plate avoids using expensive etching agents and photoresist, thereby reducing the machining cost.

[0045] The above content is only to illustrate the technical idea of the present invention and cannot be used to limit the protection scope of the present invention. Any changes made on the basis of the technical solution according to the technical idea proposed by the present invention fall within the protection scope of the claims of the present invention.

Claims

1. An electrolytic machining device for a PCHE heat exchanger plate, Characterized in that, It includes a three-dimensional moving platform, a cathode fixing plate, an electrolyte circulation device and a pulse power supply; The plate to be machined is set as the anode plate on the top of the three-dimensional moving platform. A plurality of cathode plate groups (2) are fixedly arranged side by side on the cathode fixing plate, and the cathode plate groups are located on the top of the anode plate. The outlet of the electrolyte circulation device is connected to the cathode fixing plate. The cathode of the pulse power supply is connected to the cathode plate group, and the anode of the pulse power supply is connected to the plate to be machined. An electrolyte recovery tank (6) is arranged at the bottom of the anode plate, and the electrolyte recovery tank (6) is connected to the inlet of the electrolyte circulation device; An electrolyte buffer tank (3) is arranged on the top of the cathode fixing plate. The outlet of the electrolyte circulation device is connected to the electrolyte buffer tank (3). A plurality of cathode plate groups are fixed on the bottom surface of the cathode fixing plate. The cathode plate group is connected to the pulse power supply through a loading controller (14); The cathode plate group (2) includes a cathode plate (2-1), an insulating plate (2-2) and a cathode electrode (2-3); A plurality of cathode plates (2-1) and insulating plates (2-2) are arranged vertically and alternately. The cathode electrode (2-3) is located on the top of the cathode plate (2-1) and is electrically connected. The cathode electrode (2-3) is hermetically connected to the cathode fixing plate. The connection end of the cathode electrode (2-3) passes through the electrolyte buffer tank (3) and is connected to the loading controller (14); The electrolyte circulation device includes an electrolyte storage tank (9), an electrolyte pump (12) and an electrolyte filter (7). The inlet of the electrolyte storage tank (9) is communicated with the outlet of the electrolyte recovery tank (6). The outlet of the electrolyte storage tank (9) is connected to a filter box. An electrolyte filter (7) is arranged in the filter box. The outlet of the filter box is connected to the electrolyte pump (12), and the electrolyte pump (12) is communicated with the electrolyte buffer tank (3); An electrolyte channel is arranged in the insulating plate (2-2). The upper end of the electrolyte channel is communicated with the electrolyte buffer tank, and the lower end of the electrolyte channel faces the anode plate.

2. An electrolytic machining device for a PCHE heat exchanger plate according to claim 1, Characterized in that, The adjacent two cathode plate groups (2) are insulated and connected.

3. An electrolytic machining device for a PCHE heat exchanger plate according to claim 1, Characterized in that, The arrangement mode of the cathode plates (2-1) is the same as the structure of the flow channels on the anode plate.

4. An electrolytic machining device for a PCHE heat exchanger plate according to claim 1, Characterized in that, An electrolyte cooler (8) and an electrolyte heater (15) are arranged in the electrolyte storage tank (9).

5. An electrolytic machining device for a PCHE heat exchanger plate according to claim 1, Characterized in that, A temperature sensor (4) and a pressure sensor (5) are arranged in the electrolyte buffer tank (3).

6. A method for an electrolytic machining device for a PCHE heat exchanger plate according to any one of claims 1-5, Characterized in that, It includes the following steps: Step 1: Use a stainless steel plate as the anode plate and install it on a three-dimensional moving platform. A plurality of cathode plate groups are fixed to the bottom of the cathode fixing plate; Step 2: Prepare the electrolyte and set the electrolysis parameters and machining feed parameters; Step 3: According to the parameters set in Step 2, use a plurality of cathode plate groups to process the anode plate in sequence until the processing of the anode plate is completed.

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