Gas-liquid phase change micro channel plate and heat exchange device

Abstract

The application discloses a gas-liquid phase change micro fine channel plate and a heat exchange device. The plate is provided with a channel one for liquid delivery. The channel one comprises an inlet flow guide section one, an expanded flow high resistance section, a two-stage flow distribution section, a first-stage resistance regulation section and an outlet low resistance section which are sequentially communicated from front to back. The gas-liquid phase change flow instability in the micro channel can be effectively inhibited. The heat exchange device is used for experiments under the condition of countercurrent heat exchange of cold and hot fluids. The experimental results show that, compared with the heat exchange device of the traditional micro fine channel plate, the heat exchange device adopting the plate of the application effectively eliminates the instability of the cold side gas-liquid two-phase flow, and the heat transfer efficiency is significantly improved by 19%-24% compared with the traditional plate heat exchanger. The heat exchange device of the application realizes the engineering breakthrough under the phase change heat transfer working condition.

Description

Technical Field

[0001] This invention relates to the field of heat exchange technology, specifically to a microchannel plate for gas-liquid phase change and a heat exchange device. Background Technology

[0002] Microchannel plates, as core components for efficient heat exchange in next-generation high-power electronic devices, nuclear energy, and natural gas, have been widely used due to their high heat transfer efficiency and compact size. Currently, microchannel plates have demonstrated significant advantages in single-phase heat transfer conditions; theoretically, the heat transfer coefficient of phase change heat transfer can be increased by 1-2 orders of magnitude compared to single-phase heat transfer.

[0003] However, microchannel cold plates are prone to gas-liquid two-phase flow instability under phase change conditions. This dynamic imbalance leads to a vicious cycle of uneven flow distribution and flow oscillation, causing local blockage of the microchannels and resulting in a precipitous decline in heat transfer performance. This seriously threatens the reliability of system operation. This problem has become a major obstacle to the practical application of microchannel cold plates and needs to be improved. Summary of the Invention

[0004] To address at least one of the aforementioned technical deficiencies, the present invention provides the following technical solution:

[0005] This application discloses a microchannel plate for gas-liquid phase change. The plate is provided with a channel for liquid transport. The channel includes, from front to back, an inlet guide section, a high-resistance expansion section, a secondary flow branching section, a graded resistance control section, and an outlet low-resistance section connected in sequence. The microchannels forming the high-resistance expansion section include one or more of the following: serrated, wavy, trapezoidal, gradually deformed, or other irregular shapes. The microchannels forming the graded resistance control section include one or more of the following: serrated, wavy, trapezoidal, gradually deformed, or other irregular shapes. The number of microchannels forming the outlet low-resistance section is not less than twice the number of microchannels forming the inlet guide section, and the number of microchannels forming the primary flow branching section is not less than twice the number of microchannels forming the inlet guide section.

[0006] Furthermore, it also includes a primary diversion section, which connects the inlet guide section 1 and the high-resistivity expansion section. The number of microchannels forming the primary diversion section is not less than twice the number of microchannels forming the inlet guide section 1.

[0007] Furthermore, the microchannels that make up the inlet guide section and the outlet low-resistance section include one or more types of microchannels that are straight, bent, or curved.

[0008] Furthermore, the microchannels that make up the primary diversion section and the secondary diversion section include one or more microchannels that are bent or curved.

[0009] Furthermore, it also includes a graded resistance control section and an outlet guide section one, with the graded resistance control section two connecting the outlet low resistance section and the outlet guide section one. The microchannels that make up the graded resistance control section two include one or more microchannels that extend in a sawtooth, wave, trapezoid, gradually deformed or other irregular shapes.

[0010] Furthermore, the cross-section of the microchannel is rectangular, semi-circular, circular, elliptical, or polygonal.

[0011] Furthermore, the microchannels are formed by chemical etching, machining, micro-electrical discharge machining, high-energy laser, or additive manufacturing.

[0012] The second aspect of this application discloses a heat exchange device, including the aforementioned plates, wherein the plates are cold-side plates for the passage of coolant.

[0013] Furthermore, it also includes a hot side plate, wherein the aforementioned cold side plate and hot side plate are stacked alternately, and the hot side plate is used to allow hot liquid to pass through.

[0014] Furthermore, the hot side plate is provided with a second channel for liquid transportation. The second channel includes, from front to back, an inlet guide section two, an inlet transition section, an inlet stabilizing section, a core heat exchange section, an outlet stabilizing section, an outlet transition section, and an outlet guide section two connected in sequence. The microchannels that make up the inlet transition section and the outlet transition section are bent and extended, while the microchannels that make up the inlet guide section two, the inlet stabilizing section, the core heat exchange section, the outlet stabilizing section, and the outlet guide section are straight and extended.

[0015] Furthermore, it also includes a housing, in which hot side plates and cold side plates are alternately stacked. The housing is provided with a cold side inlet and a cold side outlet that are connected to channel one on the cold side plate, and a hot side inlet and a hot side outlet that are connected to channel two on the hot side plate.

[0016] Furthermore, the cold-side inlet and cold-side outlet are respectively located at the ends of the housing, and the hot-side inlet and hot-side outlet are respectively located on the sides of the housing.

[0017] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0018] 1. The microchannel plate for gas-liquid phase change provided by this invention has an inlet guiding section, a high-resistance expansion section, and a graded resistance control section. The inlet guiding section is a flow-guiding structure with a constant flow rate or a gradient decreasing from the centerline to both sides, creating an axial pressure gradient to achieve flow homogenization at the channel inlet cross-section. The high-resistance expansion section enhances the flow resistance of the single-phase liquid working fluid within a limited heat exchange unit size, restricting the backflow of fluid in the gas-liquid phase change region. The graded resistance control section induces secondary eddies in the gas-liquid two-phase flow region through geometric control, enhancing interphase mixing, suppressing bubble aggregation and liquid phase separation, thereby effectively suppressing the phenomenon of unstable gas-liquid phase change flow within the microchannel.

[0019] 2. This heat exchange device was tested under countercurrent heat exchange conditions on the hot and cold sides. When the working fluid on the hot side was supercritical carbon dioxide, it maintained a single-phase supercritical state from the inlet (673 K) to the outlet. When the working fluid on the cold side was single-phase liquid water at the inlet (290 K), a liquid-gas phase change occurred after heat exchange, forming a gas-liquid two-phase flow at the outlet. Experimental results show that, compared with traditional microchannel plate heat exchange devices, the heat exchange device using the plates of this invention effectively eliminates the instability of the gas-liquid two-phase flow on the cold side, and the heat transfer efficiency is significantly improved by 19%-24% compared with traditional plate heat exchangers. The heat exchange device of this invention represents an engineering breakthrough under phase change heat transfer conditions. Attached Figure Description

[0020] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0021] Figure 1 This is a schematic diagram of the heat exchange device in Example 1;

[0022] Figure 2 This is a schematic diagram of the structure of the microchannel plate in Embodiment 1;

[0023] Figure 3 This is a schematic diagram of the structure of the heat-side plate of the microchannel heat exchanger in Embodiment 1;

[0024] Figure 4 This is a schematic diagram of the structure of the microchannel plate in Embodiment 1;

[0025] Figure 5 This is a schematic diagram of the structure of the heat-side plate of the microchannel heat exchanger in Embodiment 1;

[0026] Figure 6 This is a schematic diagram of the diagonally arranged heat exchange device in Embodiment 2;

[0027] Figure 7 This is a schematic diagram of the structure of the diagonally arranged microchannel plates in Example 2;

[0028] Figure 8 This is a schematic diagram of the diagonally arranged heat-generating side plates in Embodiment 2;

[0029] Figure 9 This is a schematic diagram of the structure of the microchannel plate in Example 3;

[0030] The diagram is labeled as follows: 1-plate, 2-hot-side plate, 3-cover plate, 4-bottom plate, 5-cold-side inlet, 6-cold-side outlet, 7-hot-side inlet, 8-hot-side outlet, 11-channel one, 21-channel two, 111-inlet guide section one, 112-first-stage diversion section, 113-high-resistance diversion section, 114-second-stage diversion section, 115-graded resistance control section one, 116-outlet low-resistance section, 117-graded resistance control section two, 118-outlet guide section one, 211-inlet guide section two, 212-inlet transition section, 213-inlet stabilization section, 214-core heat exchange section, 215-outlet stabilization section, 216-outlet transition section, 217-outlet guide section two. Detailed Implementation

[0031] The present invention will be further described below with reference to the accompanying drawings and specific embodiments.

[0032] In the description of this invention, it should be noted that the terms "upper," "lower," "left," "right," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limiting the scope of protection of this invention. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0033] Example 1:

[0034] like Figure 1 As shown, this heat exchange device includes several alternately stacked microchannel plates 1 for gas-liquid phase change, hot-side plates 2, and a housing formed by stacking and welding a cover plate 3 and a base plate 4. The alternately stacked microchannel plates 1 (i.e., cold-side plates) and hot-side plates 2 are located inside the housing cavity. Cold flow enters from the cold-side inlet 5 at the front end of the housing and exits from the cold-side outlet 6 at the rear end of the housing. Hot flow enters from the hot-side inlet 7 on the side of the housing and exits from the hot-side outlet 8 on the other side of the housing.

[0035] like Figure 2As shown, in this example, multiple channels 11 are arranged in parallel on the microchannel plate for gas-liquid phase change. The fluid flow direction is straight in and straight out. Channel 1 includes an inlet guide section 111, a primary flow branch section 112, a high-resistance expansion section 113, a secondary flow branch section 114, a graded resistance control section 115, and an outlet low-resistance section 116, which are connected in sequence. The inlet guide section 111, the primary flow branch section 112, the high-resistance expansion section 113, the secondary flow branch section 114, and the graded resistance control section 115 are composed of wave-shaped microchannels. The outlet low-resistance section 116 is composed of straight-shaped microchannels. The number of microchannels constituting the outlet low-resistance section is four times the number of microchannels constituting the inlet guide section 111. The number of microchannels constituting the primary flow branch section is 1.5 times the number of microchannels constituting the inlet guide section 116. The cross-sections of the microchannels that make up the inlet guide section 111, the first-stage diversion section 112, the high-resistance diversion section 113, the second-stage diversion section 114, the graded resistance control section 115, and the low-resistance outlet section 116 are all semi-circular and are formed by chemical etching.

[0036] like Figure 3 As shown, in this example, the hot side plate 2 has several parallel channels 21 arranged on it. The fluid flow direction is side in and side out. The channels 2 on the hot side plate include seven parts: inlet guide section 211, inlet transition section 212, inlet stabilizing section 213, core heat exchange section 214, outlet stabilizing section 215, outlet transition section 216, and outlet guide section 217. Inlet transition section 212 and outlet transition section 216 are composed of bent-type extended microchannels, while inlet guide section 211, inlet stabilizing section 213, core heat exchange section 214, outlet stabilizing section 215, and outlet guide section 217 are composed of straight-type extended microchannels.

[0037] The gas-liquid phase change microchannel plate 1 (i.e., the cold side plate) of this heat exchange device can also be used Figure 4 The configuration shown features multiple parallel channels 11 arranged on a microchannel plate for gas-liquid phase change. The fluid flows in a straight line. Each channel comprises a sequentially connected inlet guide section 111, a high-resistance expansion section 113, a secondary flow branching section 114, and an outlet low-resistance section 116. The inlet guide section 111, the high-resistance expansion section 113, and the secondary flow branching section 114 are composed of tortuous microchannels. The outlet low-resistance section 116 is composed of straight microchannels, and the number of microchannels comprising the outlet low-resistance section 116 is eight times the number of microchannels comprising the inlet guide section 111. The length of the inlet guide section 111 is 8 mm, the length of the high-resistance expansion section 113 is 45.6 mm, and the length of the outlet low-resistance section 116 is 294.3 mm.

[0038] The hot side plate 2 can also be used Figure 5The configuration shown has a side-in, side-out fluid flow direction. The second channel on the hot-side plate comprises five parts: inlet guide section 211, inlet transition section 212, core heat exchange section 214, outlet transition section 216, and outlet guide section 217. Inlet transition section 212 and outlet transition section 216 are composed of bent-type extended microchannels, while inlet guide section 211, core heat exchange section 214, and outlet guide section 217 are composed of straight-type extended microchannels. The number of microchannels constituting the core heat exchange section 214 is four times the number of microchannels constituting the inlet guide section 211 and outlet guide section 217. The length of the core heat exchange section 214 is 312.42 mm.

[0039] Twenty microchannel plates for gas-liquid phase change 1 ( Figure 4 (as shown in the configuration) and ten hot side plates 2 (such as Figure 5 The heat exchanger, with its alternating stacked configuration, was tested under countercurrent heat exchange conditions on the hot and cold sides. When the working fluid on the hot side was supercritical carbon dioxide, it maintained a single-phase supercritical state from the inlet (673 K) to the outlet. When the working fluid on the cold side was single-phase liquid water at the inlet (290 K), a liquid-gas phase change occurred after heat exchange, resulting in a gas-liquid two-phase flow at the outlet. Compared to traditional microchannel plate heat exchangers, this heat exchanger effectively eliminated the instability of the gas-liquid two-phase flow on the cold side, and its heat transfer efficiency was significantly improved by 22% compared to traditional plate heat exchangers.

[0040] Example 2:

[0041] This heat exchange device can also employ... Figure 6 The configuration shown includes several alternately stacked microchannel plates 1 (i.e., cold-side plates) and hot-side plates 2 for gas-liquid phase change, and a box-like structure formed by stacking and welding a cover plate 3 and a base plate 4. The inlet guide section 111 and the outlet low-resistance section 116 of channel one on the microchannel plates are arranged diagonally, as shown... Figure 7 As shown. The inlet guide section 211 and outlet guide section 216 of channel two on the hot side plate are arranged diagonally, as... Figure 8 As shown, during use, cold air flows in from the cold-side inlet 5 and out from the cold-side outlet 6. Hot air flows in from the hot-side inlet 7 and out from the hot-side outlet 8.

[0042] like Figure 7As shown, in this example, the microchannel plate for gas-liquid phase change has several parallel channels 11, including an inlet guide section 111, a high-resistance expansion section 113, a secondary flow splitting section 114, a staged resistance control section 115, an outlet low-resistance section 116, a staged resistance control section 117, and an outlet guide section 118. The inlet guide section 111 is composed of a straight-line extending microchannel, while the high-resistance expansion section 113, the secondary flow splitting section 114, the staged resistance control section 115, and the staged resistance control section 117 are composed of a wave-shaped extending microchannel. The outlet low-resistance section 116 and the outlet guide section 118 are composed of a straight-line extending microchannel.

[0043] like Figure 8 As shown, in this example, there are several parallel channels 21 on the hot side plate 2. The inlet guide section 211, the core heat exchange section 214, and the outlet guide section 217 of the hot side plate are all composed of straight microchannels.

[0044] Example 3:

[0045] This gas-liquid phase change microchannel plate can also be used as follows: Figure 9 In the configuration shown, the cold flow inlet 5 and the cold flow outlet 6 are on the same side, and the beginning and end of channel one are on the same side. Plate 1 has several parallel channels 11. Channel 11 includes an inlet guide section 111, a high-resistance expansion section 113, a secondary flow branching section 114, a graded resistance control section 115, and an outlet low-resistance section 116. The inlet guide section 111 is composed of straight, bent, extended microchannels. The high-resistance expansion section 113, the secondary flow branching section 114, and the graded resistance control section 115 are composed of wave-like extended microchannels. The outlet low-resistance section 116 is composed of straight, extended microchannels, and the number of microchannels in the outlet low-resistance section 116 is four times the number of microchannels in the inlet guide section 111.

[0046] The above are merely preferred embodiments of the present invention. The scope of protection of the present invention is not limited to the above embodiments. All technical solutions falling within the scope of the present invention's concept are within the scope of protection of the present invention. It should be noted that for those skilled in the art, any improvements and modifications made without departing from the principle of the present invention should also be considered within the scope of protection of the present invention.

Claims

1. A microchannel plate for gas-liquid phase change, characterized in that, The plate is provided with a channel for liquid transportation. The channel includes, from front to back, an inlet guide section (111), a high-resistance expansion section (113), a secondary diversion section (114), a graded resistance control section (115), and an outlet low-resistance section (116) connected in sequence. The microchannels that make up the high-resistance expansion section (113) include one or more microchannels that extend in a sawtooth, wave, trapezoid, gradient, or other irregular shape. The microchannels that make up the graded resistance control section (115) include one or more microchannels that extend in a sawtooth, wave, trapezoid, gradient, or other irregular shape. The number of microchannels that make up the outlet low-resistance section (116) is not less than twice the number of microchannels that make up the inlet guide section (111). It also includes a primary diversion section (112), which connects the inlet guide section 1 (111) and the high-resistivity expansion section (113) to form a primary diversion section (112). The number of microchannels in the primary diversion section (112) is not less than twice the number of microchannels in the inlet guide section 1 (111). It also includes a graded resistance control section two (117) and an outlet guide section one (118), with the graded resistance control section two (117) connecting the outlet low resistance section (116) and the outlet guide section one (118). The microchannels that make up the graded resistance control section two (117) include one or more microchannels that extend in a sawtooth, wave, trapezoid, gradient or other irregular shape.

2. The microchannel plate for gas-liquid phase change as described in claim 1, characterized in that: The microchannels that make up the inlet guide section (111) and the outlet low resistance section (116) include one or more of the following: straight, bent or curved microchannels. The microchannels that make up the primary diversion section (112) and the secondary diversion section (114) include one or more of the following: bends or curves.

3. The microchannel plate for gas-liquid phase change as described in claim 1, characterized in that: The cross-section of the microchannel is rectangular, semi-circular, circular, elliptical, or polygonal.

4. A heat exchange device, characterized in that: Includes the plate (1) according to any one of claims 1-3, wherein the plate (1) is a cold-side plate for allowing coolant to pass through.

5. The heat exchange device as described in claim 4, characterized in that: It also includes a hot side plate, wherein the cold side plate and the hot side plate are stacked alternately, and the hot side plate is used to allow hot liquid to pass through.

6. The heat exchange device as described in claim 4, characterized in that: The hot side plate is provided with a second channel for liquid transportation. The second channel includes, from front to back, an inlet guide section two (211), an inlet transition section (212), an inlet stabilizing section (213), a core heat exchange section (214), an outlet stabilizing section (215), an outlet transition section (216), and an outlet guide section two (217). The microchannels that make up the inlet transition section (212) and the outlet transition section (216) are bent and extended, while the microchannels that make up the inlet guide section two (211), the inlet stabilizing section (213), the core heat exchange section (214), the outlet stabilizing section (215), and the outlet guide section two (217) are straight and extended.

7. The heat exchange device as described in claim 4, characterized in that: It also includes a housing, in which hot side plates (2) and cold side plates are stacked alternately. The housing is provided with a cold side inlet (5) and a cold side outlet (6) that are connected to channel one on the cold side plate. The housing is also provided with a hot side inlet (7) and a hot side outlet (8) that are connected to channel two on the hot side plate.

8. The heat exchange device as described in claim 7, characterized in that: The cold side inlet (5) and cold side outlet (6) are respectively located at the ends of the box body, and the hot side inlet (7) and hot side outlet (8) are respectively located at the sides of the box body.

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