Printed circuit board heat exchange system capable of cleaning channel dirt

Abstract

A printed circuit board heat exchange system capable of cleaning channel dirt comprises a heat exchange assembly, the heat exchange assembly comprises a plurality of heat exchange units which are connected in parallel, the input end and the output end of each heat exchange unit are communicated with an inlet pipeline and an outlet pipeline respectively, and the printed circuit board heat exchange system further comprises a cleaning unit which is reversely connected with each heat exchange assembly in series. The cleaning unit comprises a compensation heat exchanger, an ejector and a filtering compression unit, the input end of the compensation heat exchanger communicates with the inlet pipeline, the output end of the compensation heat exchanger communicates with the input end of the ejector and the outlet pipeline at the same time, and the output end of the ejector is sequentially connected with any heat exchange unit, the filtering compression unit and the outlet pipeline in series. Through reasonable arrangement of component structures, it can be guaranteed that the heat exchanger is cleaned under the condition that the heat exchanger is not shut down or detached, the cleaning efficiency is improved, meanwhile, a heat exchange working medium can serve as cleaning fluid after pressure reduction in the cleaning process, impurities are not introduced, and resources are saved.

Description

Technical Field

[0001] The invention belongs to the technical field of printed circuit board type heat exchangers, and in particular relates to a printed circuit board heat exchange system capable of cleaning channel dirt. Background Art

[0002] Printed circuit board heat exchanger (PCHE for short) is a new type of heat exchange equipment that is efficient, compact, resistant to high temperature and high pressure. It is considered to be the most suitable heat exchanger in the supercritical carbon dioxide Brayton cycle and is widely used in the fields of fourth-generation nuclear reactors, coal-fired power plants and solar thermal power stations. PCHE consists of a microchannel structure. The flow channel is etched on the heat exchange plate by photochemical etching, and is integrated into a single piece by diffusion welding technology. In terms of size, the thickness of the heat exchange plate used for etching is 1-3mm, and the cross-section of the etched flow channel is semicircular, with a diameter of mostly 1-2mm. Compared with traditional heat exchangers, this small size design not only improves the compactness of the heat exchanger, but also increases the heat transfer area per unit volume, thereby significantly improving the heat exchange performance.

[0003] In actual operation, the PCHE core channel often has scaling or blockage problems due to its small size. The accumulation of impurities will increase the heat transfer resistance and reduce the heat transfer performance and system efficiency of the heat exchanger. If it is not cleaned in time, the accumulated dirt may block the flow channel, causing the heat exchanger to deform or even damage, which is not conducive to safe and stable operation. Due to the small flow channel diameter and long path, backflushing technology is often used in the cleaning process. This technology usually uses compressed air, water or other cleaning fluids as backflushing media, and flushes the microchannels of the heat exchanger through reverse high-pressure fluid to wash away sediments, particulate matter and impurities attached to the channel wall. Compared with chemical cleaning methods, backflushing technology is simple to operate, does not use chemicals, and reduces the risk of corrosion to the equipment.

[0004] When backflush technology is applied, the system usually needs to be shut down to ensure safe operation, and then the PCHE is disassembled for backflush treatment. This method not only significantly affects production efficiency, but also consumes a large amount of high-pressure gas or liquid, increases energy consumption and may cause resource waste. Therefore, there is an urgent need for a technology that can solve the fouling problem in printed circuit board heat exchangers without shutting down the system, so as to maintain the long-term stable operation of the heat exchanger and reduce maintenance costs. Summary of the invention

[0005] In view of the above problems, the purpose of the present invention is to provide a printed circuit board heat exchange system capable of cleaning channel dirt, so as to solve the problems in the prior art of needing to shut down the heat exchanger for cleaning, high maintenance and cleaning costs, and cumbersome cleaning.

[0006] To achieve the above object, the technical solution adopted by the present invention includes:

[0007] A printed circuit board heat exchange system capable of cleaning channel dirt includes a heat exchange component, the heat exchange component includes a plurality of parallel heat exchange units, the input end and the output end of each heat exchange unit are respectively connected to an inlet pipeline and an outlet pipeline, and also includes a cleaning unit connected in reverse series with each heat exchange component, the cleaning unit includes a compensating heat exchanger, an ejector and a filter compression unit, the input end of the compensating heat exchanger is connected to the inlet pipeline, the output end of the compensating heat exchanger is simultaneously connected to the input end and the outlet pipeline of the ejector, and the output end of the ejector is connected in series with any heat exchange unit, the filter compression unit and the outlet pipeline in sequence.

[0008] Preferably, any heat exchange unit comprises a three-way valve, a heat exchanger and a two-way valve connected in series in sequence, and the outlet of the branch pipe of the three-way valve is connected to the input end of the filter compression unit.

[0009] Preferably, a fifth two-way valve is provided at the input end of the compensating heat exchanger, a sixth two-way valve is provided between the output end of the compensating heat exchanger and the outlet pipeline, a seventh two-way valve is provided between the output end of the compensating heat exchanger and the ejector, and a two-way valve is also provided between the ejector and any heat exchanger.

[0010] Preferably, the heat exchange assembly includes four parallel heat exchange units, namely a first heat exchange unit, a second heat exchange unit, a third heat exchange unit and a fourth heat exchange unit; the first heat exchange unit includes a first three-way valve, a first heat exchanger and a first two-way valve connected in series in sequence, the second heat exchange unit includes a second three-way valve, a second heat exchanger and a second two-way valve connected in series in sequence, the third heat exchange unit includes a third three-way valve, a third heat exchanger and a third two-way valve connected in series in sequence, and the fourth heat exchange unit includes a fourth three-way valve, a fourth heat exchanger and a fourth two-way valve connected in series in sequence.

[0011] Preferably, an eighth two-way valve, a ninth two-way valve, a twelfth two-way valve and an eleventh two-way valve are respectively provided between the ejector and the first heat exchanger, the second heat exchanger, the third heat exchanger and the fourth heat exchanger.

[0012] Preferably, a pressure gauge is provided at the inlet and outlet of each heat exchanger.

[0013] Preferably, a first pressure gauge and a second pressure gauge are respectively provided at the inlet and outlet of the first heat exchanger, a third pressure gauge and a fourth pressure gauge are respectively provided at the inlet and outlet of the second heat exchanger, a fifth pressure gauge and a sixth pressure gauge are respectively provided at the inlet and outlet of the third heat exchanger, and a seventh pressure gauge and an eighth pressure gauge are respectively provided at the inlet and outlet of the fourth heat exchanger.

[0014] Furthermore, it also includes a control module, which is electrically connected to each three-way valve, two-way valve and pressure gauge.

[0015] Preferably, the filter-compression unit comprises a filter, a compressor and a twelfth two-way valve connected in series.

[0016] Compared with the prior art, the advantages of the present invention are:

[0017] (1) The present invention provides a printed circuit board heat exchange system capable of cleaning channel dirt. By rationally arranging the component structure, it is possible to ensure that the heat exchanger can be cleaned without stopping or disassembling, thereby improving the cleaning efficiency. At the same time, during the cleaning process, the heat exchange medium can be used as a cleaning fluid after the pressure is reduced, without introducing impurities and saving resources.

[0018] (2) The present invention provides a printed circuit board heat exchange system capable of cleaning channel dirt. By reasonably setting the component structure and reasonably utilizing the properties of carbon dioxide in different states, the carbon dioxide in the heat exchange process is in a supercritical state, which improves the heat exchange efficiency of the heat exchanger. The carbon dioxide in the cleaning process is in a liquid or gaseous state. By reducing the pressure and increasing the flow rate, the sediment and dirt in the heat exchanger can be effectively flushed and removed, thereby ensuring the long-term stable operation and high efficiency performance of the heat exchanger.

[0019] (3) The present invention provides a printed circuit board heat exchange system capable of cleaning channel dirt. By reasonably setting the component structure, the heat exchanger can be cleaned online while ensuring the heat exchange performance. No human intervention is required, which improves production efficiency and can generate certain economic benefits. At the same time, the heat exchange medium supercritical carbon dioxide in the system is decompressed into liquid or gaseous state and then used as a cleaning raw material, saving resources and costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] The accompanying drawings are used to provide a further understanding of the present invention and constitute a part of the specification. Together with the following specific embodiments, they are used to explain the present invention but do not constitute a limitation of the present invention. In the accompanying drawings:

[0021] Figure 1 It is a structural schematic diagram of a printed circuit board heat exchange system capable of cleaning channel dirt of the present invention;

[0022] Figure 2 A schematic diagram of the electrical connection of the control module of the present invention;

[0023] Figure 3 This is the control logic diagram of the control module.

[0024] The symbols in the figure represent:

[0025] 1 inlet pipeline; 5 ejector; 7 filter; 8 compressor; 9 outlet pipeline; 10 control module

[0026] 2A is the first three-way valve, 2B is the second three-way valve, 2C is the third three-way valve, and 2D is the fourth three-way valve;

[0027] 3A is the first heat exchanger, 3B is the second heat exchanger, 3C is the third heat exchanger, 3D is the fourth heat exchanger, and 3E is the compensating heat exchanger;

[0028] 4A is the first two-way valve, 4B is the second two-way valve, 4C is the third two-way valve, 4D is the fourth two-way valve, 4E is the fifth two-way valve; 4F is the sixth two-way valve; 4G is the seventh two-way valve; 4H is the eighth two-way valve; 4I is the ninth two-way valve; 4J is the twelfth two-way valve; 4K is the eleventh two-way valve; 4L is the twelfth two-way valve;

[0029] 6A is the first pressure gauge, 6B is the second pressure gauge, 6C is the third pressure gauge, 6D is the fourth pressure gauge, 6E is the fifth pressure gauge; 6F is the sixth pressure gauge; 6G is the seventh pressure gauge; 6H is the eighth pressure gauge. DETAILED DESCRIPTION

[0030] The invention is not limited to the following specific embodiments, and all equivalent changes made on the basis of the technical solution of this application fall within the protection scope of the invention.

[0031] It should be noted that, unless otherwise specified, all components and devices in the present invention are components and devices known in the prior art.

[0032] Example

[0033] The present embodiment discloses a printed circuit board heat exchange system capable of cleaning channel dirt, including a heat exchange component, the heat exchange component including a plurality of parallel heat exchange units, the input end and the output end of each heat exchange unit are respectively connected to the inlet pipeline 1 and the outlet pipeline 9, and also includes a cleaning unit connected in reverse series with each heat exchange component, the cleaning unit includes a compensating heat exchanger 3E, an ejector 5 and a filter compression unit, the input end of the compensating heat exchanger 3E is connected to the inlet pipeline 1, the output end of the compensating heat exchanger 3E is simultaneously connected to the input end and the outlet pipeline 9 of the ejector 5, and the output end of the ejector 5 is connected in series with any heat exchange unit, the filter compression unit and the outlet pipeline 9 in sequence;

[0034] Its function is as follows: when any heat exchange unit needs to be cleaned, its function will be replaced by the compensating heat exchanger 3E, and one compensating heat exchanger 3E can replace the heat exchange function of multiple sets of conventional heat exchangers, which can ensure that the performance of the heat exchange system will not be significantly reduced in the cleaning state and can still maintain normal operation; the entire cleaning process does not require manual disassembly and cleaning, which improves production efficiency; at the same time, the properties of carbon dioxide in different states are reasonably utilized. The carbon dioxide in the heat exchange process is in a supercritical state, which improves the heat exchange efficiency of the heat exchanger, while the carbon dioxide in the cleaning process is in a liquid or gaseous state. By reducing the pressure and increasing the flow rate, it can effectively flush and remove the sediment and dirt in the heat exchanger, thereby ensuring the long-term stable operation and high-efficiency performance of the heat exchanger. In addition, both processes use carbon dioxide, which does not introduce impurities and achieves the purpose of saving resources.

[0035] Among them, the ejector 5 can be used to treat supercritical carbon dioxide after passing through the compensating heat exchanger, reduce it to a gas phase or a liquid phase and increase the flow rate. By integrating the ejector into the cleaning system, the backwash effect is enhanced by using a high-speed jet, thereby improving the removal efficiency of the deposits.

[0036] The filtering and compression unit disclosed in this embodiment includes a filter 7, a compressor 8 and a twelfth two-way valve 4L connected in series in sequence. The filter is used to remove dirt contained in the fluid after backblowing, and the compressor is used to pressurize the filtered fluid to a supercritical state as required.

[0037] Specifically, any heat exchange unit includes a three-way valve, a heat exchanger and a two-way valve connected in series in sequence, and the outlet of the branch pipe of the three-way valve is connected to the input end of the filter compression unit.

[0038] The heat exchanger disclosed in this embodiment is a printed circuit board type heat exchanger, and a heat exchange core is arranged in the heat exchanger. The flow channel in the heat exchange core is a straight channel or a Z-shaped channel widely used in engineering. Compared with other continuous flow channel or discontinuous flow channel structures, the production and processing of these two channels are relatively simple and the performance is reliable. The fluid in the channel is carbon dioxide, and carbon dioxide presents different states at different pressures and temperatures. In existing research, the pressure range of carbon dioxide used for heat exchange with the heat source in the main heat exchanger is 15MPa-20MPa, which is in a supercritical state. The compensating heat exchanger 3E has the same specifications as the first heat exchanger 3A, the second heat exchanger 3B, the third heat exchanger 3C and the fourth heat exchanger 3D, and is used to replace the heat exchange function of the conventional heat exchanger during cleaning.

[0039] A fifth two-way valve 4E is provided at the input end of the compensating heat exchanger 3E disclosed in this embodiment, a sixth two-way valve 4F is provided between the output end of the compensating heat exchanger 3E and the outlet pipeline 9, a seventh two-way valve 4G is provided between the output end of the compensating heat exchanger 3E and the ejector 5, and a two-way valve is also provided between the ejector 5 and any heat exchanger.

[0040] The heat exchange assembly disclosed in this embodiment includes four parallel heat exchange units, namely the first heat exchange unit, the second heat exchange unit, the third heat exchange unit and the fourth heat exchange unit; the first heat exchange unit includes the first three-way valve 2A, the first heat exchanger 3A and the first two-way valve 4A connected in series in sequence, the second heat exchange unit includes the second three-way valve 2B, the second heat exchanger 3B and the second two-way valve 4B connected in series in sequence, the third heat exchange unit includes the third three-way valve 2C, the third heat exchanger 3C and the third two-way valve 4C connected in series in sequence, and the fourth heat exchange unit includes the fourth three-way valve 2D, the fourth heat exchanger 3D and the fourth two-way valve 4D connected in series in sequence. The eighth two-way valve 4H, the ninth two-way valve 4I, the twelfth two-way valve 4J and the eleventh two-way valve 4K are respectively arranged between the ejector 5 and the first heat exchanger 3A, the second heat exchanger 3B, the third heat exchanger 3C and the fourth heat exchanger 3D.

[0041] Specifically, each heat exchanger is equipped with a pressure gauge at the inlet and outlet. The pressure gauge can be a pressure sensor to monitor the pressure of the fluid before and after the heat exchanger and transmit the signal to the control module. Scaling or blockage will significantly increase the pressure drop during the heat exchange process. When the pressure drop value in the signal obtained by the control device is higher than the threshold, the cleaning system is turned on by regulating the valve.

[0042] In this embodiment, a first pressure gauge 6A and a second pressure gauge 6B are respectively provided at the inlet and outlet of the first heat exchanger 3A, a third pressure gauge 6C and a fourth pressure gauge 6D are respectively provided at the inlet and outlet of the second heat exchanger 3B, a fifth pressure gauge 6E and a sixth pressure gauge 6F are respectively provided at the inlet and outlet of the third heat exchanger 3C, and a seventh pressure gauge 6G and an eighth pressure gauge 6H are respectively provided at the inlet and outlet of the fourth heat exchanger 3D.

[0043] Specifically, it also includes a control module, which is electrically connected to each three-way valve, two-way valve and pressure gauge;

[0044] Its function is: by introducing the control module, the pressure signal is monitored to detect that the pressure drop of the printed circuit board type heat exchanger in the heat exchange system is too large due to scaling. The control valve will close the heat exchange branch that needs to be cleaned and connect it to the cleaning system. After cleaning, the heat exchanger whose pressure drop meets the requirement can be automatically incorporated into the heat exchange system through the control valve, reducing manual intervention and improving cleaning efficiency.

[0045] like Figure 3 As shown, when the system of this embodiment is normally exchanging heat, the two-way valves 4E-4L are closed and the cleaning system does not work. The three-way valves 2A-2D are partially opened (a, b are open, c is closed), and the supercritical carbon dioxide from the inlet pipeline 1 can enter the conventional printed circuit board type heat exchanger 3A-3D, but cannot enter the filter 7. The two-way valves 4A-4D at the outlet are opened, and the supercritical carbon dioxide that has completed the heat exchange process is merged into the outlet pipeline 9.

[0046] The cleaning system is started according to the pressure signal, taking the branch where the conventional printed circuit board heat exchanger 3A is located as an example. When the pressure difference value ΔP of the pressure gauges 6A and 6B in the heat exchange system branch is greater than or equal to the threshold ΔP0, the cleaning system is connected to the branch. Under the regulation of the control device, the three-way valve 2A is partially opened (a is closed, b, c are opened), and the two-way valve 4E is opened. The supercritical carbon dioxide from the inlet pipeline 1 cannot enter the conventional printed circuit board heat exchanger 3A, but flows into the compensation printed circuit board heat exchanger 3E. The two-way valves 4F and 4G adjust the opening to control the flow rate of supercritical carbon dioxide flowing into the ejector 5. The two-way valve 4H is opened and 4A is closed, and the high-flow liquid or gaseous carbon dioxide flowing out of the ejector 5 enters the printed circuit board heat exchanger 3A in reverse, thereby achieving a cleaning effect. After that, the carbon dioxide passes through the three-way valve 2A, and the impurities therein are filtered in the filter 7. After being compressed by the compressor 8, the pure carbon dioxide passes through the two-way valve 4L and is merged into the outlet pipe 9 together with other supercritical carbon dioxide passing through the conventional heat exchangers 3B-3D. Similarly, the pressure signal is used to determine whether the cleaning process is completed. When the pressure difference value ΔP' between the pressure gauges 6B and 6A is less than or equal to the threshold ΔP1, it is considered that the cleaning is complete, and the control device 9 adjusts the three-way valve 2A and the two-way valves 4A, 4E-4H to restore the heat exchange system to a normal heat exchange state.

[0047] The preferred embodiments of the present disclosure are described in detail above in conjunction with the accompanying drawings; however, the present disclosure is not limited to the specific details in the above embodiments. Within the technical concept of the present disclosure, a variety of simple modifications can be made to the technical solution of the present disclosure, and these simple modifications all fall within the protection scope of the present disclosure.

[0048] It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any suitable manner without contradiction. In order to avoid unnecessary repetition, the present disclosure will not further describe various possible combinations.

[0049] In addition, the various different implementation modes disclosed in this solution may be arbitrarily combined, and as long as they do not violate the concept of the present disclosure, they should also be regarded as the content invented by the present disclosure.

Claims

1. A printed circuit board heat exchange system capable of cleaning channel dirt, comprising a heat exchange component, wherein the heat exchange component comprises a plurality of heat exchange units connected in parallel, wherein the input end and the output end of each heat exchange unit are respectively connected to an inlet pipeline (1) and an outlet pipeline (9), wherein: It also includes a cleaning unit that is reversely connected in series with each heat exchange component, and the cleaning unit includes a compensating heat exchanger (3E), an ejector (5) and a filter-compression unit. The input end of the compensating heat exchanger (3E) is connected to the inlet pipeline (1), and the output end of the compensating heat exchanger (3E) is simultaneously connected to the input end of the ejector (5) and the outlet pipeline (9), and the output end of the ejector (5) is connected in series with any heat exchange unit, the filter-compression unit and the outlet pipeline (9) in sequence.

2. The printed circuit board heat exchange system capable of cleaning channel dirt according to claim 1, characterized in that: Any of the heat exchange units comprises a three-way valve, a heat exchanger and a two-way valve connected in series in sequence, and the outlet of the three-way valve branch pipe is connected to the input end of the filter compression unit.

3. The printed circuit board heat exchange system capable of cleaning channel dirt according to claim 2, characterized in that: A fifth two-way valve (4E) is provided at the input end of the compensating heat exchanger (3E), a sixth two-way valve (4F) is provided between the output end of the compensating heat exchanger (3E) and the outlet pipeline (9), a seventh two-way valve (4G) is provided between the output end of the compensating heat exchanger (3E) and the ejector (5), and a two-way valve is also provided between the ejector (5) and any heat exchanger.

4. A printed circuit board heat exchange system capable of cleaning channel dirt as claimed in any one of claims 1 to 3, characterized in that: The heat exchange assembly includes four parallel heat exchange units, namely a first heat exchange unit, a second heat exchange unit, a third heat exchange unit and a fourth heat exchange unit; The first heat exchange unit comprises a first three-way valve (2A), a first heat exchanger (3A) and a first two-way valve (4A) connected in series in sequence; the second heat exchange unit comprises a second three-way valve (2B), a second heat exchanger (3B) and a second two-way valve (4B) connected in series in sequence; the third heat exchange unit comprises a third three-way valve (2C), a third heat exchanger (3C) and a third two-way valve (4C) connected in series in sequence; and the fourth heat exchange unit comprises a fourth three-way valve (2D), a fourth heat exchanger (3D) and a fourth two-way valve (4D) connected in series in sequence.

5. The printed circuit board heat exchange system capable of cleaning channel dirt according to claim 4, characterized in that: An eighth two-way valve (4H), a ninth two-way valve (4I), a twelfth two-way valve (4J) and an eleventh two-way valve (4K) are respectively provided between the ejector (5) and the first heat exchanger (3A), the second heat exchanger (3B), the third heat exchanger (3C) and the fourth heat exchanger (3D).

6. The printed circuit board heat exchange system capable of cleaning channel dirt according to claim 5, characterized in that: A pressure gauge is provided at the inlet and outlet of each heat exchanger.

7. The printed circuit board heat exchange system capable of cleaning channel dirt according to claim 6, characterized in that: The first heat exchanger (3A) is provided with a first pressure gauge (6A) and a second pressure gauge (6B) at the inlet and outlet, respectively; the second heat exchanger (3B) is provided with a third pressure gauge (6C) and a fourth pressure gauge (6D) at the inlet and outlet, respectively; the third heat exchanger (3C) is provided with a fifth pressure gauge (6E) and a sixth pressure gauge (6F) at the inlet and outlet, respectively; and the fourth heat exchanger (3D) is provided with a seventh pressure gauge (6G) and an eighth pressure gauge (6H) at the inlet and outlet, respectively.

8. The printed circuit board heat exchange system capable of cleaning channel dirt according to claim 7, characterized in that: It also includes a control module, which is electrically connected to each three-way valve, two-way valve and pressure gauge.

9. The printed circuit board heat exchange system capable of cleaning channel dirt according to claim 8, characterized in that: The filtering and compression unit comprises a filter (7), a compressor (8) and a twelfth two-way valve (4L) which are connected in series in sequence.

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