Compact heat exchanger for producing subcooled water

Abstract

The application provides a compact heat exchanger for preparing supercooled water, which comprises a heat exchange part and a heat preservation layer. The heat exchange part comprises a plurality of microstructure channel sheets stacked and atomically diffusion bonded to form a three-dimensional hollow structure, a working fluid channel group between adjacent microstructure channel sheets, the microstructure channel sheet comprising a heat exchange area, inlets and outlets arranged on opposite sides of the heat exchange area, an atomically diffusion bonded area in a region around the heat exchange area except the inlets and outlets, and the distribution directions of the inlets and outlets of two adjacent microstructure channel sheets being different; and the heat preservation layer is located outside the side plates of the heat exchange part.

Description

Technical Field

[0001] This invention relates to the field of heat exchanger technology, and more specifically to a compact heat exchanger for preparing subcooled water. Background Technology

[0002] Regarding the preparation method of supercooling water, plate heat exchangers or other types of heat exchangers are currently used to continuously generate supercooling water. After the water containing insoluble solid particles reaches the supercooling temperature, the ice nuclei formed on the surface of the insoluble solids are very easy to freeze quickly when they encounter a small energy disturbance, blocking the channels of the heat exchanger, which is commonly known as ice blockage. Therefore, the supercooling degree of the supercooling water cannot exceed -3.5℃.

[0003] In view of this, it is necessary to provide an ultra-compact heat exchanger suitable for subcooled water preparation systems to solve the above-mentioned technical problems. Summary of the Invention

[0004] The purpose of this invention is to provide a compact heat exchanger for preparing subcooled water.

[0005] To solve one of the above-mentioned technical problems, the present invention adopts the following technical solution:

[0006] A compact heat exchanger for producing subcooled water includes:

[0007] The heat exchange section includes two side plates and a plurality of microstructured channel plates. Each microstructured channel plate includes a heat exchange zone, inlet and outlet located on opposite sides of the heat exchange zone, and an atomic diffusion bonding zone located around the heat exchange zone excluding the inlet and outlet. The plurality of microstructured channel plates are stacked between the two side plates and atomically diffusely bonded to the two side plates to form a whole. A working fluid channel is formed between adjacent microstructured channel plates, and the inlet and outlet of two adjacent microstructured channel plates have different distribution directions.

[0008] The insulation layer is located outside the two side plates of the heat exchange section.

[0009] Furthermore, the heat exchange zone is provided with a plurality of microstructures. After atomic diffusion and bonding, the microstructures combine with adjacent microstructure channel sheets to divide the working fluid channel into a working fluid microchannel group. The hydraulic diameter of the working fluid microchannel is no greater than 0.4 mm, and the length of the microchannel is no greater than 50 mm.

[0010] Furthermore, the heat exchange zone is provided with a plurality of microstructures, the microstructures are longitudinally elongated, the aspect ratio of the microstructures is between 4 and 6, and the extension direction of the microstructures is consistent with the inlet and outlet arrangement direction.

[0011] Furthermore, the plurality of microstructures are distributed along a plurality of wavy lines, the plurality of wavy lines extend along the inlet and outlet arrangement direction, and the plurality of wavy lines are spaced apart along a direction perpendicular to the inlet and outlet arrangement direction; along a direction perpendicular to the inlet and outlet arrangement direction, the microstructures on adjacent wavy lines are staggered along the inlet and outlet arrangement direction.

[0012] Furthermore, the compact heat exchanger also includes the flow guiding structure connected to both ends of the working fluid channel. The flow guiding structure includes a variable diameter section connected to the heat exchange section and an extension section connected to the side of the variable diameter section away from the heat exchange section. The inner cavity of the variable diameter section is funnel-shaped or conical, and the inner diameter of the variable diameter section gradually decreases from the heat exchange section to the extension section.

[0013] Furthermore, the insulation layer includes an insulation portion located on the outside of the two side plates and a drainage interface connected to the insulation portion.

[0014] Furthermore, the insulation layer includes a plurality of insulation channel sheets located outside the side plate and an end plate located on the side of the plurality of insulation channel sheets opposite to the side plate. Each insulation channel sheet includes an insulation area, inlet and outlet located on opposite sides of the insulation area, and an atomic diffusion bonding area located around the insulation area excluding the inlet and outlet. The plurality of insulation channel sheets are directly stacked and atomically diffused bonded to the end plate and the side plate, and an insulation fluid channel is formed between adjacent insulation channel sheets. The inlet and outlet of all insulation channel sheets are distributed in the same direction.

[0015] Furthermore, the heat-insulating channel sheet has the same structure as the microstructure channel sheet.

[0016] Furthermore, the drainage interface includes a connecting part connected to the insulation part and a turning part connected to the end of the connecting part away from the insulation part.

[0017] Furthermore, the inner cavity of the connecting part is funnel-shaped or conical, and the equivalent diameter of the connecting part gradually decreases from the heat-insulating part to the turning part.

[0018] Furthermore, the inlet and outlet of the heat-insulating channel sheet are aligned with the inlet and outlet of a portion of the microstructure channel sheet along the stacking direction;

[0019] The compact heat exchanger also includes the flow guiding structure connected to both ends of the working fluid channel, the flow guiding structure including a variable diameter section connected to the heat exchange part and an extension section connected to the side of the variable diameter section away from the heat exchange part;

[0020] The end of the steering portion away from the connecting portion is offset from the end of the extension portion away from the enlarged diameter portion.

[0021] Furthermore, the extension direction of the extension is consistent with the inlet and outlet direction of the water channel, and the turning angle of the turning part is between 60° and 120°.

[0022] Furthermore, the drainage structure and the drainage interface are integrally formed.

[0023] A supercooled water preparation system includes an antifreeze flow system, a water flow system, and a control system. The antifreeze flow system is connected via pipelines to form a circulation loop, comprising a first thermostatic device, a first water pump, a first flow meter, a first pressure gauge, and a compact heat exchanger. The water flow system includes, via pipelines, a second thermostatic device, a second water pump, a second flow meter, a second pressure gauge, and the compact heat exchanger, all connected to a water source and controlling the water temperature. The control system is communicatively connected to the first thermostatic device, the first water pump, the first flow meter, the first pressure gauge, the second thermostatic device, the second water pump, the second flow meter, and the second pressure gauge. The control system includes a first inlet temperature sensor connected to the inlet of the antifreeze channel, a first outlet temperature sensor connected to the outlet of the antifreeze channel, a second inlet temperature sensor connected to the inlet of the water channel, and a second outlet temperature sensor connected to the outlet of the water channel.

[0024] An ice-making system includes the aforementioned subcooled water ice-making system and an ice-making device located at the water channel outlet of a compact heat exchanger.

[0025] The beneficial effects of the present invention are: the compact heat exchanger of the present invention has microchannels for water and microchannels for antifreeze, which improves heat exchange performance and reduces the transit time of the working fluid in the compact heat exchanger, thereby reducing the risk of freezing. Attached Figure Description

[0026] Figure 1 This is a schematic diagram of the heat exchanger according to a preferred embodiment of the present invention;

[0027] Figure 2 for Figure 1 A diagram from another angle;

[0028] Figure 3 for Figure 2 A cross-sectional view along the AA direction;

[0029] Figure 4 for Figure 3 Partial exploded view;

[0030] Figure 5 for Figure 1 A schematic diagram of the drainage structure on the outlet side;

[0031] Figure 6 This is a schematic diagram of the heat exchange section;

[0032] Figure 7 for Figure 6 Partial exploded view;

[0033] Figure 8 This is a schematic diagram of the microstructure channel sheet of the present invention;

[0034] Figure 9 for Figure 8 A structural diagram from another angle;

[0035] Figure 10 This is a schematic diagram of a subcooling water preparation system according to a preferred embodiment of the present invention;

[0036] Figure 11 This is a schematic diagram of an ice-making system according to a preferred embodiment of the present invention.

[0037] 1-Compact heat exchanger; 11-Heat exchange section; 111-Microstructured channel plate; 112-Heat exchange zone; 113-Inlet / outlet; 114-Atomic diffusion bonding region; 115-Microstructure; 116-Base plate; 117-Top plate; 118-Recessed portion; 119-Pin hole; 12-Flow guiding structure; 121-Variable diameter section; 122-Extension section; 13-Insulation layer; 131-Insulation section; 132-Flow guiding interface; 133-Connecting part; 134-Tuning part. Detailed Implementation

[0038] The present invention will now be described in detail with reference to the specific embodiments shown in the accompanying drawings. However, these embodiments do not limit the present invention, and any structural, methodological, or functional modifications made by those skilled in the art based on these embodiments are included within the scope of protection of the present invention.

[0039] In the various illustrations of this invention, for ease of illustration, certain dimensions of structures or parts may be exaggerated relative to other structures or parts; therefore, only the basic structure of the subject matter of this invention is used to illustrate the invention.

[0040] Please refer to Figures 1-9 As shown, this is a compact heat exchanger 1 designed by the present invention for preparing supercooled water; for ease of description, a coordinate system O-XYZ is established.

[0041] The compact heat exchanger 1 includes a heat exchange section 11 and a flow guiding structure 12 connected to the heat exchange section 11; the heat exchange section 11 serves as a heat exchange unit for antifreeze and water, and the flow guiding structure 12 plays a role in guiding and converging the fluid entering and exiting the compact heat exchanger 1.

[0042] The heat exchange section 11 includes two side plates and a plurality of microstructured channel plates 111 located between the two side plates.

[0043] Two side plates are distributed along the OZ direction, namely the bottom plate 116 and the top plate 117. The side plates are approximately 2mm thick and have a certain load-bearing capacity, which protects the internal microstructure channel sheet 111.

[0044] The microstructure channel sheet 111 is made of SUS316L sheet with a mirror surface, and a heat exchange zone 112, an inlet and outlet 113 located on opposite sides of the heat exchange zone 112, and an atomic diffusion bonding region 114 located in the area surrounding the heat exchange zone 112 excluding the inlet and outlet 113 are formed by photo-etching process.

[0045] Specifically, the portion outside the microstructure 115 and the atomic diffusion bonding region 114 is etched away by photolithography. The microstructure 115 and the atomic diffusion bonding region 114 have the same thickness and have a good bonding effect with the adjacent microstructure channel sheet 111.

[0046] Preferably, the thickness of the microstructure 115 is half the thickness of the sheet, which can also be understood as the thickness of the etched portion being half the thickness of the sheet. In this embodiment, the thickness of the sheet is 0.2 mm, and the height of the microstructure 115 is 0.1 mm.

[0047] Multiple microstructured channel plates 111 are stacked between two side plates and atomically diffusely bonded to form a whole, constituting a three-dimensional hollow heat exchange section 11. Working fluid channels are formed between adjacent microstructured channel plates 111. The working fluid channels include alternating water channels and antifreeze channels, and correspondingly, the microstructured channel plates 111 include water channel plates and antifreeze channel plates. The heat exchange zone 112 is provided with multiple microstructures 115. After atomic diffusion bonding, the microstructures 115 combine with adjacent microstructured channel plates 111 to divide the heat exchange zone 112 into a group of working fluid microchannels. The hydraulic diameter of each microchannel is no greater than 0.4 mm, the length of each microchannel is no greater than 50 mm, and the number of microchannels is no less than 600. When water flows through the microchannels at a flow rate of 0.017 l / s to 0.032 l / s, the transit time in the compact heat exchanger 1 is 0.038 s to 0.072 s. This compact heat exchanger 1 improves heat exchange between two working fluids through microchannels with small hydraulic diameters. It can greatly reduce the length of the working fluid microchannels, thereby reducing the transit time of water in the working fluid channels and lowering the risk of water acting as an ice nucleus and causing icing.

[0048] In one embodiment, the hydraulic diameter of the working fluid channel is 0.32 mm, the channel length is 21.5 mm, the number of channels is 720, the channel has no bends, and the water flows smoothly, which can further avoid the occurrence of ice blockage.

[0049] The microstructure 115 is elongated, and its extension direction is consistent with the arrangement direction of the inlet and outlet 113. The aspect ratio of the microstructure 115 is between 4 and 6, for example, 1.5 mm in length and 0.3 mm in width. In this embodiment, the microstructure 115 is elliptical, spindle-shaped, or rhomboid.

[0050] The plurality of microstructures 115 are distributed along a plurality of wavy lines, the plurality of wavy lines extend along the arrangement direction of the inlet and outlet 113, and the plurality of wavy lines are spaced apart along a direction perpendicular to the arrangement direction of the inlet and outlet 113.

[0051] Furthermore, along a direction perpendicular to the arrangement direction of the inlet and outlet 113, the microstructures 115 on adjacent wavy lines are staggered along the arrangement direction of the inlet and outlet 113.

[0052] In this invention, along the length of the atomic diffusion bonding region 114, the length of each wavy line is designed to include a peak and a trough, and the amplitude of the wavy line is small, with only two microstructures 115 accommodating between the peak and the trough.

[0053] In this embodiment, adjacent microstructured channel sheets 111 are cross-stacked, meaning that the inlet / outlet 113 of one microstructured channel sheet 111 corresponds to the atomic diffusion bonding region 114 of the other microstructured channel sheet 111. Alternatively, one microstructured channel sheet 111 can be understood as being rotated 90° relative to the other microstructured channel sheet 111, forming two working fluid channels with substantially perpendicular flow directions. The inlet / outlet 113 of one working fluid channel is along the OX direction for the flow of antifreeze, while the inlet / outlet 113 of the other working fluid channel is along the OY direction for the flow of water. Of course, the antifreeze can also be a refrigerant; any liquid medium capable of providing cooling to water is acceptable.

[0054] The top plate 117, the bottom plate 116, and the atomic diffusion bonding regions 114 of the plurality of microstructure channel plates 111 form the enclosure of the heat exchange section 11 after being stacked and atomic diffusion bonded. The flow guiding structure 12 is connected to the enclosure and communicates with the corresponding working fluid channel.

[0055] The flow guiding structure 12 includes a variable diameter section 121 connected to the heat exchange section 11 and an extension section 122 connected to the side of the variable diameter section 121 away from the heat exchange section 11. The inner cavity of the variable diameter section 121 is funnel-shaped or conical, and its inner diameter (equivalent diameter) gradually decreases from the heat exchange section 11 towards the extension section 122, guiding the working fluid to flow smoothly. The extension section 122 is connected to the piping of the application system via a connector.

[0056] Furthermore, the compact heat exchanger 1 also includes insulation layers 13 located on both sides of the heat exchange section 11 in the stacking direction, that is, the insulation layers 13 are located outside the two side plates; to prevent the cold energy of the heat exchange section 11 from leaking outward, causing the surface temperature of the heat exchange section 11 to be too low and forming condensation or crystallization, so as not to affect the flow of subcooling water at the outlet of the water channel.

[0057] Preferably, the insulation layer 13 includes an insulation portion 131 and a drainage port 132 connected to the insulation portion 131. The insulation portion 131 is located outside the side plate of the heat exchange portion 11, and the drainage port 132 is used to connect to an external pipeline.

[0058] The insulation portion 131 includes a plurality of insulation channel pieces 1311 located outside the side plate and an end plate 1312 located on the side of the plurality of insulation channel pieces 1311 opposite to the side plate. Each insulation channel piece 1311 includes an insulation area, inlet and outlet located on opposite sides of the insulation area, and an atomic diffusion bonding area located around the insulation area excluding the inlet and outlet. The plurality of insulation channel pieces 1311 are directly stacked and atomically diffused bonded to the end plate 1312 and the side plate. An insulation fluid channel is formed between adjacent insulation channel pieces 1311. The inlet and outlet of all insulation channel pieces 1311 are distributed in the same direction.

[0059] Preferably, the heat-insulating channel plate 1311 has the same structure as the microstructure channel plate, that is, the microstructure channel plate is used as the heat-insulating channel plate 1311, and the heat exchange area of ​​the microstructure channel plate is the heat-insulating area of ​​the heat-insulating channel plate 1311. Specifically, it can be understood that the heat-insulating part 131 is formed by the co-directional stacking and atomic diffusion combination of a plurality of the above-mentioned microstructure channel plates 111, and the inlet and outlet 113 of adjacent microstructure channel plates 111 are aligned, that is, the inlet and outlet 113 of the working fluid channel are aligned, water is introduced, and the heat exchange part 11 inside is protected.

[0060] The drainage port 132 includes a connecting portion 133 connected to the insulation portion 131 and a turning portion 134 connected to the end of the connecting portion 133 away from the insulation portion 131. The inner cavity of the connecting portion 133 is also funnel-shaped or conical, and its equivalent diameter gradually decreases from the insulation portion 131 to the turning portion 134, guiding the water flow to flow smoothly.

[0061] The turning part 134 is a bent pipe, spatially offset from the extension part 122, and its end is connected to the water supply pipe via a connector. In one specific embodiment, the inlet and outlet of the heat-insulating channel plate 1311 are aligned with the inlet and outlet of the microstructure channel plate 111 forming the water channel along the stacking direction; the end of the turning part 134 away from the connecting part 133 is offset from the end of the extension part 122 away from the enlarged diameter part 121.

[0062] The extension direction of the extension 122 is consistent with the inlet and outlet direction of the water channel, and the turning angle of the turning part 134 is between 60° and 120°, and is 90° in this embodiment.

[0063] In this embodiment, the length of the connecting part 133 is less than the length of the variable diameter part 121, and it cooperates with the turning part 134 without occupying the design space of the drainage structure 12.

[0064] In this invention, the heat exchange section 11 and the insulation layer 13 are separated by a top plate 117 and a bottom plate 116, and are stacked together and atomically diffused to form a whole. The drainage interface 132 is integrally set with the drainage structure 12 located on the same side, resulting in a compact structure.

[0065] The water flowing into the insulation layer 13 is preferably the same as the water in the heat exchange section 11, but it can also be different.

[0066] Please refer to Figure 10 The diagram illustrates the application of the compact heat exchanger of the present invention in a subcooling water preparation system. The subcooling water preparation system includes an antifreeze flow system 2, a water flow system 3, and a control system.

[0067] The control system includes a data acquisition unit, a data processing unit, and a command sending unit. The acquisition unit is used to collect information such as flow rate, pressure, and temperature of the antifreeze flow system 2 and the water flow system 3. After processing the collected information, the data processing unit sends commands to the first temperature control device 21, the first water pump 22, the second temperature control device 31, and the second water pump 32 via the command sending unit to adjust the system operation to obtain subcooled water with a lower temperature.

[0068] Specifically, the data acquisition unit includes a first flow meter 23, a first pressure gauge 24, a first inlet temperature sensor connected to the inlet of the antifreeze channel, and a first outlet temperature sensor connected to the outlet of the antifreeze channel for acquiring data from the antifreeze flow system 2; and a second flow meter 33, a second pressure gauge 34, a second inlet temperature sensor connected to the inlet of the water channel, and a second outlet temperature sensor connected to the outlet of the water channel for acquiring data from the water flow system 3.

[0069] The circulation loop of the antifreeze flow system 2 includes a first thermostatic device 21, a first water pump 22, a first flow meter 23, a first pressure gauge 24, a first inlet temperature sensor, the compact heat exchanger 1, and a first outlet temperature sensor, all connected by pipelines. When the first water pump 22 is started, the antifreeze (LLC) circulates within the circulation loop. The first thermostatic device 21 controls the temperature of the antifreeze within a first preset temperature range of -8.0℃ to -10.0℃, and the inlet temperature of the antifreeze entering the compact heat exchanger 1 is controlled between -6.0℃ and -8.0℃.

[0070] The first water pump 22 is a variable frequency pump, which facilitates the adjustment of flow rate and system pressure.

[0071] Furthermore, the antifreeze flow system 2 also includes a first filter 25 for filtering the antifreeze. The first filter 25 is a 400-mesh metal mesh, preferably a stainless steel mesh, to avoid corrosion of the antifreeze and to prevent contamination of the antifreeze.

[0072] In addition, the antifreeze flow system 2 also includes a first ball valve 26 to improve the precise control of the system.

[0073] The water flow system 3 includes the following components connected by pipes: a second thermostat 31 connected to a water source and controlling the water temperature, a second water pump 32, a second flow meter 33, a second pressure gauge 34, a second inlet temperature sensor, a compact heat exchanger 1, and a second outlet temperature sensor.

[0074] The supercooled water preparation system of this invention is suitable for the continuous and stable preparation of supercooled water using tap water, and for industrial application in ice making, including but not limited to ice crystals, ice particles, and ice blocks. Of course, it is even more suitable for water that has been filtered, processed by ion exchange columns, or distilled to achieve higher purity.

[0075] The second thermostat 31 is used to control the water temperature within a second preset temperature range. The cooperation between the second thermostat 31 and the first thermostat 21 ensures that the temperature of the water and antifreeze entering the compact heat exchanger 1 is relatively constant, thus keeping the outlet water temperature stable and preventing ice blockage.

[0076] In addition, the second constant temperature device 31 reduces the temperature of the water source to near 0°C, for example, between 0.5°C and 3°C, through a refrigeration system, alleviating the requirements on the heat exchange performance of the compact heat exchanger 1. In this invention, the temperature of the water source entering the compact heat exchange zone 112 is controlled between 2.5°C and 4°C, for example, around 3°C, and the outlet water temperature of the compact heat exchanger 1 is between -2°C and -3.8°C.

[0077] The second temperature control device 31 and the first temperature control device 21 can provide cooling capacity directly or indirectly through the same refrigeration system, or they can provide cooling capacity directly or indirectly through two different refrigeration systems.

[0078] The second water pump 32 is preferably a variable frequency pump, which facilitates the adjustment of flow rate and system pressure.

[0079] Furthermore, the water flow system 3 also includes a second filter 35 connected between the second thermostat 31 and the compact heat exchanger 1 to remove insoluble solid particles, reduce ice nuclei, and thus mitigate or prevent ice blockage. In one reference embodiment, the second filter 35 is a 400-mesh metal filter screen connected between the second water pump 32 and the compact heat exchanger 1.

[0080] In addition, the water flow system 3 also includes a second ball valve 36 to improve the precise control of the system.

[0081] The structure of the compact heat exchanger 1 is as described above and will not be repeated. The antifreeze in the antifreeze flow system 2 and the water in the water flow system 3 flow through two working fluid channels of the same compact heat exchanger 1, where they exchange heat to produce subcooled water. The control system detects and controls the entire system to ensure stable and continuous production of subcooled water.

[0082] This invention employs a compact heat exchanger 1 with good heat exchange performance and an extremely shortened working fluid channel length. By exploring factors such as inlet water temperature, flow rate, and transit time, it is expected to obtain a lower subcooling degree and a longer duration t.

[0083] Specifically, this invention uses tap water and antifreeze as working fluids, and the compact heat exchanger 1 described above as a heat exchanger for continuously generating subcooled water. The first water pump 22 and the second water pump 32 are used to adjust the flow rates q1 and q2 of the antifreeze and water, respectively. The first temperature control device 21 and the second temperature control device 31 are used to adjust the fluid inlet temperature T of the antifreeze and water entering the compact heat exchanger 1, respectively. 1,in T 2,in The minimum achievable subcooling water temperature and duration t are determined; based on the collected basic data, existing problems are analyzed and solutions are proposed.

[0084] When considering the continuous generation conditions of cooling water, based on the principle of energy conservation, when the temperature T of the tap water... 2,in The inlet temperature T of the antifreeze LLC is set at 3℃, and the flow rate is determined according to the design range of the heat exchanger. 1,in The determination must be matched with the target subcooling degree of the generated tap water.

[0085] Based on the above-described supercooling water preparation system, the present invention also provides a supercooling water preparation method, and the application performance of the heat exchanger of the present invention has been described. The method includes the following steps: S1, activating the first thermostat 21 of the antifreeze flow system 2 to control the temperature of the antifreeze to a first preset temperature range; S2, activating the second thermostat 31 of the water flow system 3 to control the temperature of the water to a second preset temperature range; S3, after the water temperature reaches the second preset temperature range, activating the second water pump 32 of the water flow system 3 to control the temperature T of the water entering the water channel of the compact heat exchanger 1. 2,in The temperature of the water entering the compact heat exchanger 1 from S4 tends to stabilize; 2,in After the temperature stabilizes, the first water pump 22 of the antifreeze flow system 2 is turned on, and the antifreeze flows through the antifreeze channel of the compact heat exchanger 1. The flow rate of the antifreeze q1 and the flow rate of the water q2 are adjusted so that the temperature of the water flowing out of the compact heat exchanger 1 reaches the expected cooling temperature.

[0086] In steps S1 and S2, the opening order of the first temperature-regulating device 21 and the second temperature-regulating device 31 is not limited; they can be opened simultaneously or sequentially. However, step S3 is preferably located after steps S2 and S1, and step S4 is located after step S3.

[0087] In step S3, the effect of water flow fluctuations on water temperature T is taken into account. 2,in The effect depends on the temperature T of the water entering the water channel of the compact heat exchanger 1. 2,in Adjust the frequency of the second water pump 32 to control the water flow rate q1.

[0088] In step S4, after starting the first water pump 22, the flow rate q1 of the antifreeze is first adjusted to its maximum value; when the inlet temperature T of the antifreeze entering the compact heat exchanger 1 is... 1,in After stabilizing, the water flow rate q2 is further adjusted so that the temperature of the water flowing out of the compact heat exchanger 1 reaches the expected cooling temperature.

[0089] The temperature T of the antifreeze entering the compact heat exchanger 1 1,in The temperature T of the water entering the compact heat exchanger 1 is between -6.0℃ and -8.0℃. 2,in Between 2.5℃ and 4℃, the water subcooling degree can be well controlled within the expected range.

[0090] Please refer to Figure 11 As shown, the present invention also provides an ice-making system 200, including the above-described supercooled water preparation system 100 and an ice-making device located at the outlet of a compact heat exchanger 1. The supercooled water produced by the above-described supercooled water preparation system 100 and its method is in an unstable state and forms ice crystals / ice particles when subjected to minor external stimuli.

[0091] In one embodiment, the ice-making device is an ice bucket or ice pool 4. After the supercooled water drips into the ice bucket or ice pool 4, it impacts the wall and turns into ice crystals / ice particles. The ice bucket or ice pool 4 is located below the water channel outlet of the compact heat exchanger 1.

[0092] Ideally, the cooling water flowing out of the compact heat exchanger 1 has reached the target cooling temperature and, after dripping into the ice bucket, impacts the wall of the ice bucket and turns into ice crystals / ice particles. However, in the initial stage of operation of the supercooled water preparation system 100, the water flowing out of the compact heat exchanger 1 is not sufficiently supercooled, and some cold water will remain in the ice bucket. Alternatively, during the preparation of cooling water, some ice crystals / ice particles will melt into water.

[0093] To drain the water from the ice bucket and prevent it from affecting ice crystals / ice particles, a drain outlet or drain valve can be installed on the ice bucket to drain the cold water as needed. Preferably, this portion of the cold water is recycled to avoid waste. The water flow system 3 of the present invention also includes a return pipe connecting the ice bucket and the second thermostat 31, and a return water pump 5 connected to the return pipe, for returning the cold water in the ice bucket to the second thermostat 31 for repeated recycling and continued participation in the preparation of cooling water, without causing waste of water and cooling capacity.

[0094] It should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This way of describing the specification is only for clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

[0095] The detailed descriptions listed above are merely specific descriptions of feasible embodiments of the present invention, and are not intended to limit the scope of protection of the present invention. All equivalent embodiments or modifications made without departing from the spirit of the present invention should be included within the scope of protection of the present invention.

Claims

1. A compact heat exchanger for preparing subcooled water, characterized in that, The compact heat exchanger includes: The heat exchange section includes two side plates and a plurality of microstructured channel plates. Each microstructured channel plate includes a heat exchange zone, inlet and outlet located on opposite sides of the heat exchange zone, and an atomic diffusion bonding zone located around the heat exchange zone excluding the inlet and outlet. The plurality of microstructured channel plates are stacked between the two side plates and atomically diffusely bonded to the two side plates to form a whole. A working fluid channel is formed between adjacent microstructured channel plates, and the inlet and outlet of two adjacent microstructured channel plates have different distribution directions, while the inlet and outlet of two spaced-apart microstructured channel plates have the same distribution direction. An insulation layer is located outside the two side plates of the heat exchange section; the insulation layer includes an insulation portion located outside the two side plates and a flow-draining interface connected to the insulation portion; the insulation portion includes a plurality of insulation channel plates located outside the side plates and an end plate located on the side of the plurality of insulation channel plates opposite to the side plates; the insulation channel plate includes an insulation area, inlet and outlet located on opposite sides of the insulation area, and an atomic diffusion bonding area located around the insulation area excluding the inlet and outlet; the plurality of insulation channel plates are stacked and atomically diffused bonded between the end plate and the side plates, and an insulation fluid channel is formed between adjacent insulation channel plates; the inlet and outlet of all insulation channel plates are distributed in the same direction; The heat exchange section and the insulation layer are separated by the side plate, and are stacked together and atomically diffused to form a whole.

2. The compact heat exchanger for preparing subcooled water according to claim 1, characterized in that: The heat exchange zone is provided with a plurality of microstructures. After atomic diffusion and bonding, the microstructures combine with adjacent microstructure channel sheets to divide the working fluid channel into a working fluid microchannel group. The hydraulic diameter of the working fluid microchannel is no greater than 0.4 mm and the length of the microchannel is no greater than 50 mm.

3. The compact heat exchanger for preparing subcooled water according to claim 1, characterized in that: The heat exchange zone is provided with a plurality of microstructures, each of which is longitudinally elongated and has an aspect ratio between 4 and 6. The extension direction of the microstructure is consistent with the inlet and outlet arrangement direction.

4. The compact heat exchanger for preparing subcooled water according to claim 1, characterized in that, The plurality of microstructures are distributed along a plurality of wavy lines, the plurality of wavy lines extend along the inlet and outlet arrangement direction, and the plurality of wavy lines are spaced apart along a direction perpendicular to the inlet and outlet arrangement direction; along a direction perpendicular to the inlet and outlet arrangement direction, the microstructures on adjacent wavy lines are staggered along the inlet and outlet arrangement direction.

5. The compact heat exchanger for preparing subcooled water according to claim 1, characterized in that, The compact heat exchanger further includes the flow-guiding structure connected to both ends of the working fluid channel. The flow-guiding structure includes a variable diameter section connected to the heat exchange section and an extension section connected to the side of the variable diameter section away from the heat exchange section. The inner cavity of the variable diameter section is funnel-shaped or conical, and the inner diameter of the variable diameter section gradually decreases from the heat exchange section to the extension section.

6. The compact heat exchanger for preparing subcooled water according to claim 1, characterized in that, The multiple microstructured channel sheets are identical, and the inlet and outlet of one microstructured channel sheet corresponds to the atomic diffusion binding region of the adjacent microstructured channel sheet.

7. The compact heat exchanger for preparing subcooled water according to any one of claims 1 to 6, characterized in that, The working fluid channel includes alternating water channels for water flow and antifreeze channels for antifreeze flow, with the inlet and outlet of all the insulation channel plates aligned with the inlet and outlet of the microstructure channel plates forming the water channels along the stacking direction.

8. The compact heat exchanger for preparing subcooled water according to claim 7, characterized in that, The heat-insulating channel sheet has the same structure as the microstructure channel sheet.

9. The compact heat exchanger for preparing subcooled water according to claim 7, characterized in that, The drainage interface includes a connecting part connected to the insulation part and a turning part connected to the end of the connecting part away from the insulation part.

10. The compact heat exchanger for preparing subcooled water according to claim 9, characterized in that, The inner cavity of the connecting part is funnel-shaped or conical, and the equivalent diameter of the connecting part gradually decreases from the heat-insulating part to the turning part.

11. The compact heat exchanger for preparing subcooled water according to claim 9, characterized in that, The inlet and outlet of the thermal insulation channel sheet are aligned with the inlet and outlet of a portion of the microstructure channel sheet along the stacking direction. The compact heat exchanger also includes the flow guiding structure connected to both ends of the working fluid channel, the flow guiding structure including a variable diameter section connected to the heat exchange part and an extension section connected to the side of the variable diameter section away from the heat exchange part; The end of the steering portion away from the connecting portion is offset from the end of the extension portion away from the enlarged diameter portion.

12. The compact heat exchanger for preparing subcooled water according to claim 11, characterized in that, The extension direction of the extension is consistent with the inlet and outlet direction of the water channel, and the turning angle of the turning part is between 60° and 120°.

13. The compact heat exchanger for preparing subcooled water according to claim 11, characterized in that, The drainage structure and the drainage interface are integrated into one unit.

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