Experiment section for boiling test and boiling test device

Abstract

The utility model relates to an experiment section for a boiling test and a boiling test device.The experiment section for the boiling test comprises an experiment structure, an inlet pipeline and an outlet pipeline, and the experiment structure comprises a shell internally provided with a flow channel and a heating piece for heating fluid in the flow channel; an inlet of the flow channel is communicated with the outlet end of the inlet pipeline, an outlet of the flow channel is communicated with the inlet end of the outlet pipeline, and the cross section of the inlet pipeline, the cross section of the outlet pipeline and the cross section of the flow channel are all rectangular. The boundary dimension of the cross section of the inlet pipeline and the boundary dimension of the cross section of the outlet pipeline are the same as the boundary dimension of the cross section of the flow channel. Due to the fact that the cross section shapes and the boundary dimensions of the inlet pipeline, the flow channel and the outlet pipeline are kept consistent, the flow pattern change caused by sudden change of the fluid channel is avoided, the hydraulic loss is effectively reduced, and the fluid flows more stably and evenly.

Description

Technical Field

[0001] This application relates to the field of hot working hydraulic testing technology, and in particular to an experimental section and a boiling test apparatus for boiling tests. Background Technology

[0002] Currently, improving the heat transfer characteristics of fluid boiling is receiving increasing attention in the refrigeration and heating fields. Due to its advantages such as large heat transfer area, good heat transfer performance, and compact structure, the rectangular narrow channel fluid boiling heat exchange structure has become one of the commonly used structural forms for enhancing heat transfer and is widely used in various heat exchange equipment.

[0003] Two-phase flow pattern refers to the geometric shape or structural form formed at the interface between two phases in a two-phase flow. Currently, in the experimental section of the boiling test apparatus, the gas phase in the gas-liquid two-phase flow is easily compressible, and the interface is easily deformable. When the liquid is heated and evaporates in the channel, as the proportion of evaporated gas increases, the liquid and the generated gas will exhibit different flow structures. In the boiling heat transfer of a rectangular narrow channel, different flow patterns have their unique heat transfer and flow mechanisms. Changes in flow pattern will cause changes in flow resistance and flow stability, thus leading to differences in heat transfer performance. However, the flow stability of the fluid in the experimental section of the current rectangular channel boiling test apparatus is poor. Utility Model Content

[0004] Therefore, it is necessary to provide an experimental section for boiling tests that ensures stable fluid flow.

[0005] This application provides an experimental section for boiling tests, including an experimental structure, an inlet pipe, and an outlet pipe. The experimental structure includes a shell with an internal flow channel and a heating element for heating the fluid in the flow channel. The inlet of the flow channel is connected to the outlet end of the inlet pipe, and the outlet of the flow channel is connected to the inlet end of the outlet pipe. The cross-sections of the inlet pipe, the outlet pipe, and the flow channel are all rectangular, and the external dimensions of the cross-sections of the inlet pipe and the outlet pipe are the same as the external dimensions of the cross-section of the flow channel.

[0006] In one embodiment, the length of both the inlet pipe and the outlet pipe is L, and the hydraulic diameter of both the inlet pipe and the outlet pipe is D, wherein the length L and the diameter D satisfy: L≥30D.

[0007] In one embodiment, the housing includes a base and a cover plate covering the base, the base and the cover plate forming the flow channel, at least a portion of the cover plate being a transparent plate, and the heating element being disposed on the base.

[0008] In one embodiment, the experimental structure further includes a pressure member that presses against the cover plate, the cover plate being located between the pressure member and the base.

[0009] In one embodiment, the heating element is provided with at least two rows of temperature measuring groups arranged at intervals along the vertical direction, and each row of temperature measuring groups has at least one temperature measuring hole.

[0010] In one embodiment, each row of temperature measuring groups has at least two temperature measuring holes arranged at intervals along the length of the flow channel.

[0011] In one embodiment, the base has a cavity with an open top, and at least part of the heating element is located in the cavity. The heating element is provided with three rows of temperature measuring groups, which are defined from top to bottom as the first temperature measuring group, the second temperature measuring group, and the third temperature measuring group. The distance between the first temperature measuring group and the top surface of the heating element is L1, the distance between the second temperature measuring group and the top surface of the heating element is L2, and the distance between the third temperature measuring group and the top surface of the heating element is L3. The distances L1, L2, and L3 satisfy: L1 = 1mm~3mm, L2 = 4mm~6mm, and L3 = 7mm~9mm.

[0012] This application also provides a boiling test apparatus, including a water tank, a heater, a test section, and a condenser. The test section is the test section described in any of the above embodiments. The water tank is provided with an inlet pipe for high-pressure gas to enter. A control valve is provided on the inlet pipe. The outlet of the water tank is connected to the inlet pipe through the heater. The outlet pipe is connected to the inlet of the condenser. The outlet of the condenser is connected to the inlet of the water tank.

[0013] In one embodiment, the boiling test apparatus further includes a heating system for controlling the heating power of the heating element. The heating system includes an electric heating rod, a power meter, and a voltage regulator. The electric heating rod is electrically connected to the power meter, and the power meter is electrically connected to the voltage regulator.

[0014] In one embodiment, the boiling test apparatus further includes a data acquisition system, which includes a camera and a data acquisition unit. The camera is mounted on the test section and configured to capture and record the distribution of bubbles when the fluid boils in the test section. The heating element is provided with a temperature measuring hole, and the data acquisition unit is electrically connected to the temperature measuring element in the temperature measuring hole.

[0015] Compared with the prior art, in the experimental section for boiling tests provided in this application, when the medium enters the experimental section, the cross-sectional shape and external dimensions of the inlet pipe, flow channel and outlet pipe are kept consistent, which avoids changes in flow pattern caused by abrupt changes in the fluid channel, effectively reduces hydraulic loss, and thus makes the fluid flow more stable and uniform. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in the embodiments of this application or the conventional technology, the drawings used in the description of the embodiments or the conventional technology will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0017] Figure 1 This is a system diagram of a boiling test apparatus according to an embodiment of this application;

[0018] Figure 2 This is a schematic diagram of the structure of an experimental segment according to an embodiment of this application;

[0019] Figure 3 for Figure 2 A magnified view of a section at point I;

[0020] Figure 4 for Figure 3 A magnified view of a portion of the heating element.

[0021] Reference numerals: 1. Experimental section; 11. Experimental structure; 111. Shell; 1110. Flow channel; 1111. Base; 1112. Cover plate; 1113. Cavity; 112. Heating element; 113. Pressing element; 12. Inlet pipe; 13. Outlet pipe; 141. First temperature measuring group; 142. Second temperature measuring group; 143. Third temperature measuring group; 144. Temperature measuring hole; 2. Water tank; 31. First pipeline; 32. Water pump; 33. Flow meter; 34. Valve; 4. Heater; 5. Condenser; 6. Storage chamber; 61. Air inlet pipe; 62. Control valve; 7. Heating system; 71. Power meter; 72. Pressure regulator; 8. Data acquisition system; 81. Camera; 82. Data acquisition device. Detailed Implementation

[0022] To make the above-mentioned objectives, features, and advantages of this application more apparent and understandable, the specific embodiments of this application are described in detail below with reference to the accompanying drawings. Many specific details are set forth in the following description to provide a thorough understanding of this application. However, this application can be implemented in many other ways different from those described herein, and those skilled in the art can make similar modifications without departing from the spirit of this application. Therefore, this application is not limited to the specific embodiments disclosed below.

[0023] It should be noted that when a component is referred to as being "fixed to" or "set on" another component, it can be directly on the other component or there may be an intermediate component. When a component is considered to be "connected" to another component, it can be directly connected to the other component or there may be an intermediate component present. The terms "vertical," "horizontal," "upper," "lower," "left," "right," "side," "top," "bottom," and similar expressions used in this application's specification are merely for describing various exemplary structural parts and elements of this application. However, their use herein is for illustrative purposes only and is determined based on the exemplary orientations shown in the accompanying drawings, and does not represent the only possible implementation. Since the embodiments disclosed in this application can be arranged in different orientations, these terms indicating orientation are for illustrative purposes only and should not be considered as limitations. For example, "upper" and "lower" are not necessarily limited to directions opposite to or consistent with the direction of gravity.

[0024] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this application, "multiple" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0025] In this application, unless otherwise expressly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature and the second feature are in indirect contact through an intermediate medium. Furthermore, "above," "over," and "on top" the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0026] It should be noted that "axial arrangement" means that the overall arrangement direction is along the axial direction, including but not limited to axial extension, and may be at an angle to the axial direction.

[0027] Unless otherwise defined, all technical and scientific terms used in this application have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used in this application is for the purpose of describing particular embodiments only and is not intended to be limiting of the application. The term "and / or" as used in this application includes any and all combinations of one or more of the associated listed items.

[0028] like Figures 2-4As shown, this application discloses an experimental section for boiling tests. Specifically, the experimental section 1 includes an experimental structure 11, an inlet pipe 12, and an outlet pipe 13. The experimental structure 11 includes a shell 111 with an internal flow channel 1110 and a heating element 112 for heating the fluid within the flow channel 1110. The inlet of the flow channel 1110 is connected to the outlet end of the inlet pipe 12, and the outlet of the flow channel 1110 is connected to the inlet end of the outlet pipe 13. The cross-sections of the inlet pipe 12, the outlet pipe 13, and the flow channel 1110 are all rectangular, and the external dimensions of the cross-sections of the inlet pipe 12 and the outlet pipe 13 are the same as the external dimensions of the cross-section of the flow channel 1110.

[0029] The fluid channel of experimental section 1 includes the aforementioned inlet pipe 12, flow channel 1110 and outlet pipe 13. It can be understood that when the medium enters the fluid channel in experimental section 1, since the cross-sectional shape and external dimensions of the inlet pipe 12, flow channel 1110 and outlet pipe 13 are consistent, the change in flow pattern caused by abrupt changes in the fluid channel is avoided, effectively reducing hydraulic losses and making the fluid flow more stable and uniform.

[0030] It should be noted that the cross-sections of the inlet pipe 12, the outlet pipe 13, and the flow channel 1110 are all rectangular. Therefore, the statement that "the external dimensions of the cross-sections of the inlet pipe 12 and the outlet pipe 13 are the same as the external dimensions of the flow channel 1110" means that the length and width of the cross-section of the inlet pipe 12 are the same as the length and width of the cross-section of the flow channel 1110, and the length and width of the cross-section of the outlet pipe 13 are the same as the length and width of the cross-section of the flow channel 1110. Since the inlet of the flow channel 1110 is connected to the outlet of the inlet pipe 12, the inlet of the flow channel 1110 and the outlet of the inlet pipe 12 must be sealed together, and the outlet of the flow channel 1110 and the inlet of the outlet pipe 13 must also be sealed together to prevent media leakage.

[0031] In this embodiment, the length of both the inlet pipe 12 and the outlet pipe 13 is L, and the hydraulic diameter of both the inlet pipe 12 and the outlet pipe 13 is D. The length L and the diameter D satisfy: L≥30D.

[0032] It is understandable that when the length of the inlet pipe 12 is sufficient, the flow of the medium tends to be stable, reducing the influence of the velocity at the inlet of the experimental section 1 on the medium, thereby making the flow of the medium entering the flow channel 1110 more stable and uniform. The medium flowing out of the flow channel 1110 flows into the outlet pipe 13. Since the length of the outlet pipe 13 is sufficient, the flow of the medium in the outlet pipe 13 gradually tends to be stable, which is conducive to ensuring the stability and uniformity of the medium flow in the entire experimental section 1.

[0033] Specifically, the aforementioned housing 111 includes a base 1111 and a cover plate 1112 covering the base 1111. A flow channel 1110 is formed between the base 1111 and the cover plate 1112. At least a portion of the cover plate 1112 is transparent. The heating element 112 is disposed on the base 1111. In this embodiment, the cover plate 1112 is an acrylic plate, thus allowing for better observation of the bubble distribution during the boiling of the medium within the experimental structure 11.

[0034] Furthermore, the aforementioned experimental structure 11 also includes a pressing member 113 that presses against the cover plate 1112, with the cover plate 1112 located between the pressing member 113 and the base 1111. Thus, under the downward pressure of the pressing member 113, the cover plate 1112 is pressed firmly against the base 1111. In this embodiment, as... Figure 2 and Figure 3 As shown, the top surface of the cover plate 1112 is provided with the aforementioned pressure member 113 at both ends along the length of the flow channel.

[0035] In this embodiment, the heating element 112 is provided with at least two rows of temperature measuring groups arranged at intervals along the vertical direction. Each row of temperature measuring groups has at least one temperature measuring hole 144, and the temperature measuring hole 144 is located on the heating element 112. It is understood that the presence of the temperature measuring hole 144 allows the temperature at the corresponding location to be measured by the temperature measuring element within the temperature measuring hole 144, and the heat flux density can be calculated based on the thermal conductivity and height difference of the heating element 112, thereby obtaining the wall temperature of the shell 111 from the heat flux density. It should be noted that the formula for calculating the heat flux density is a well-known formula, and will not be elaborated upon in this application.

[0036] Furthermore, each row of temperature measuring groups has at least two temperature measuring holes 144 spaced apart along the length of the flow channel 1110. In this way, the temperature at different heights of the heating element 112 can be measured, and the wall temperature of the housing 111 can be obtained more effectively.

[0037] Specifically, the base 1111 has a cavity 1113 with an open top. At least part of the heating element 112 is located within the cavity 1113. Three rows of temperature measuring groups are arranged on the heating element 112, defined from top to bottom as the first temperature measuring group 141, the second temperature measuring group 142, and the third temperature measuring group 143. The distance between the first temperature measuring group 141 and the top surface of the heating element 112 is L1, the distance between the second temperature measuring group 142 and the top surface of the heating element 112 is L2, and the distance between the third temperature measuring group 143 and the top surface of the heating element 112 is L3. Wherein, L1 = 1mm~3mm, illustratively, L1 can be 1mm, 2mm, 3mm, or any other value within 1~3mm. L2 = 4mm~6mm, illustratively, L2 can be 4mm, 5mm, 6mm, or any other value within 4~6mm. L3 = 7mm~9mm. Schematic, L3 can be 7mm, 8mm, 9mm, or any other value within the range of 7-9mm. This allows for the measurement of temperatures at different heights of the heating element 112, providing a better understanding of the wall temperature of the housing 111.

[0038] The heating element 112 is a copper heating block, but heating blocks of other materials can also be used. The base 1111 is made of stainless steel, but other materials can also be used as needed.

[0039] like Figure 1 As shown, this application also provides a boiling test apparatus, which includes a water tank 2, a heater 4, a condenser 5 and the aforementioned test section 1. The water tank 2 is provided with an inlet pipe 61 for high-pressure gas to enter, and a control valve 62 is provided on the inlet pipe 61. The outlet of the water tank 2 is connected to the inlet pipe 12 through the heater 4, and the outlet pipe 13 is connected to the inlet of the condenser 5. The outlet of the condenser 5 is connected to the inlet of the water tank 2.

[0040] Thus, by controlling the opening and closing of control valve 62, water tank 2 can be selectively pressurized, thereby controlling the inlet pressure of experimental section 1. High-pressure gas refers to any gas that can pressurize the water tank. The temperature of the medium inlet of experimental section 1 is controlled by controlling the heating power of heater 4. In addition, in order to connect heater 4 to inlet pipe 12 and outlet pipe 13 to condenser 5, adapters are usually installed at the outlet end of outlet pipe 13 and the inlet end of inlet pipe 12.

[0041] like Figure 1 As shown, the boiling test apparatus also includes a storage chamber 6 for storing high-pressure gas, and the outlet of the storage chamber 6 is connected to the inlet of the air inlet pipe 61. In this way, the high-pressure gas in the storage chamber 6 can enter the water tank 2 through the air inlet pipe 61.

[0042] The water tank 2 is connected to the heater 4 via a first pipe 31. A water pump 32, a flow meter 33, and a valve 34 for controlling the water flow are installed on the first pipe 31. Along the fluid (medium) flow path within the first pipe 31, the flow meter 33 is located downstream of the valve 34, and the water pump 32 is located upstream of the valve 34. Thus, the flow rate entering the experimental section 1 can be controlled by adjusting the opening of the valve 34, and the flow meter 33 can provide a more direct view of the actual flow rate entering the experimental section 1.

[0043] The working process of the above-mentioned boiling test device is as follows: the water pump 32 provides power to allow the test medium to start from the water tank 2, pass through the water pump 32, valve 34, flow meter 33, heater 4 and enter the test section 1. After the medium is heated and boiled in the test section 1, it is cooled by the condenser 5 and then returns to the water tank 2.

[0044] Furthermore, the aforementioned boiling test apparatus also includes a heating system 7 for controlling the heating power of the heating element 112. The heating system 7 includes an electric heating rod (not shown), a power meter 71, and a voltage regulator 72. The electric heating rod is electrically connected to the power meter 71, the power meter 71 is electrically connected to the voltage regulator 72, and the voltage regulator 72 is electrically connected to a power source. In this embodiment, the electric heating rod is positioned below the heating element 112.

[0045] The control principle of the heating system 7 described above is the same as that in the prior art, and will not be repeated in this application.

[0046] Furthermore, the boiling test apparatus also includes a data acquisition system 8, which includes a camera 81 and a data acquisition unit 82. The camera 81 is mounted on the test section 1 and is configured to capture and record the distribution of bubbles when the fluid (medium) in the test section 1 boils. The data acquisition unit 82 is electrically connected to the temperature measuring element in the temperature measuring hole 144.

[0047] The data acquisition unit 82 is electrically connected to the flow meter 33. In addition, a temperature sensor for detecting the temperature at the inlet, a first pressure sensor for detecting the pressure at the inlet, and a second pressure sensor for detecting the pressure at the outlet of the experimental section 1 are provided at the inlet of the experimental section 1. The data acquisition unit 82 is electrically connected to the temperature sensor, the first pressure sensor, and the second pressure sensor, respectively, so as to collect the temperature and pressure at the inlet of the experimental section 1 and the pressure at the outlet.

[0048] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0049] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the patent application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the scope of protection of this application. Therefore, the patent protection scope of this application should be determined by the appended claims.

Claims

1. An experimental section for boiling tests, characterized in that, The experimental structure includes an experimental structure (11), an inlet pipe (12), and an outlet pipe (13). The experimental structure (11) includes a shell (111) with a flow channel (1110) inside and a heating element (112) for heating the fluid in the flow channel (1110). The inlet of the flow channel (1110) is connected to the outlet end of the inlet pipe (12), and the outlet of the flow channel (1110) is connected to the inlet end of the outlet pipe (13). The cross-sections of the inlet pipe (12), the outlet pipe (13), and the flow channel (1110) are all rectangular, and the external dimensions of the cross-sections of the inlet pipe (12) and the outlet pipe (13) are the same as the external dimensions of the cross-section of the flow channel (1110).

2. The experimental section according to claim 1, characterized in that, The lengths of the inlet pipe (12) and the outlet pipe (13) are both L, and the hydraulic diameters of the inlet pipe (12) and the outlet pipe (13) are both D. The length L and the diameter D satisfy: L≥30D.

3. The experimental section according to claim 1, characterized in that, The housing (111) includes a base (1111) and a cover plate (1112) covering the base (1111), the base (1111) and the cover plate (1112) enclose and form the flow channel (1110), at least part of the cover plate (1112) is a transparent plate, and the heating element (112) is disposed on the base (1111).

4. The experimental section according to claim 3, characterized in that, The experimental structure (11) also includes a pressure member (113) that presses against the cover plate (1112), the cover plate (1112) being located between the pressure member (113) and the base (1111).

5. The experimental segment according to claim 3 or 4, characterized in that, The heating element (112) is provided with at least two rows of temperature measuring groups arranged at intervals along the vertical direction, and each row of temperature measuring groups has at least one temperature measuring hole (144).

6. The experimental section according to claim 5, characterized in that, Each row of temperature measuring groups has at least two temperature measuring holes (144) arranged at intervals along the length of the flow channel (1110).

7. The experimental section according to claim 6, characterized in that, The base (1111) has a cavity (1113) with an open top. At least part of the heating element (112) is located in the cavity (1113). The heating element (112) is provided with three rows of temperature measuring groups. The three rows of temperature measuring groups are defined from top to bottom as the first temperature measuring group (141), the second temperature measuring group (142), and the third temperature measuring group (143). The distance between the first temperature measuring group (141) and the top surface of the heating element (112) is L1, the distance between the second temperature measuring group (142) and the top surface of the heating element (112) is L2, and the distance between the third temperature measuring group (143) and the top surface of the heating element (112) is L3. The distances L1, L2, and L3 satisfy: L1 = 1mm~3mm, L2 = 4mm~6mm, and L3 = 7mm~9mm.

8. A boiling test apparatus, characterized in that, The device includes a water tank (2), a heater (4), an experimental section (1), and a condenser (5). The experimental section (1) is the experimental section according to any one of claims 1 to 7. The water tank (2) is provided with an air inlet pipe (61) for high-pressure gas to enter. A control valve (62) is provided on the air inlet pipe (61). The outlet of the water tank (2) is connected to the inlet pipe (12) through the heater (4). The outlet pipe (13) is connected to the inlet of the condenser (5). The outlet of the condenser (5) is connected to the inlet of the water tank (2).

9. The boiling test apparatus according to claim 8, characterized in that, It also includes a heating system (7) for controlling the heating power of the heating element (112), the heating system (7) including an electric heating rod, a power meter (71) and a voltage regulator (72), the electric heating rod being electrically connected to the power meter (71) and the power meter (71) being electrically connected to the voltage regulator (72).

10. The boiling test apparatus according to claim 9, characterized in that, It also includes a data acquisition system (8), which includes a camera (81) and a data acquisition device (82). The camera (81) is set on the experimental section (1) and is configured to capture and record the distribution of bubbles when the fluid boils in the experimental section (1). The heating element (112) is provided with a temperature measuring hole (144), and the data acquisition device (82) is electrically connected to the temperature measuring element in the temperature measuring hole (144).

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