Non-intrusive Reynolds shear layer cold and hot air mixed flow device

Abstract

The utility model discloses a non-intrusive type Reynolds shear layer cold and hot air flow mixing device which comprises a flow mixing pipeline, a cold air pipeline and a hot air pipeline, the cold air pipeline and the hot air pipeline are connected with the flow mixing pipeline, and the whole flow mixing pipeline is composed of a first horizontal section, a second horizontal section and a vertical section connected with the first horizontal section and the second horizontal section. The first horizontal section is provided with a Reynolds shear layer generator and a mixer, the second horizontal section is provided with a detection mechanism, and the end of the cold air pipeline and the end of the hot air pipeline are connected with the mixed flow pipeline through the Reynolds shear layer generator. Under the synergistic effect of the Reynolds shear layer generator and the adjustable mixer, efficient mixing of cold air and hot air is achieved, and temperature uniformity is ensured.

Description

Technical Field

[0001] The utility model relates to the field of cold and hot air mixing devices, in particular to a non-invasive Reynolds shear layer cold and hot air mixing flow device. Background Art

[0002] In coal-fired power plant boilers, the primary fuel is coal. A coal mill grinds the raw coal into pulverized coal, which is then fed into the furnace for combustion. Different coal types, such as anthracite, bituminous coal, and lignite, require the pulverizer outlet temperature to be controlled within different ranges. This is primarily achieved by controlling the temperature of the primary air at the pulverizer inlet. The primary air at the pulverizer inlet is a mixture of hot and cold primary air. The temperature of the primary air at the pulverizer inlet is adjusted by adjusting the ratio of hot to cold primary air. In addition to the primary air temperature, the pulverizer also has requirements for the primary air volume when grinding pulverized coal.

[0003] The accuracy of coal mill inlet air volume directly impacts the economic efficiency and stability of the boiler's pulverizing and combustion systems. Due to the expansion of power plant scale and space constraints, the layout of coal mill systems has become increasingly compact, and the primary air duct has become shorter and shorter. This leads to uneven mixing of cold and hot primary air at the coal mill inlet. Furthermore, the disturbance caused by various flow-blocking components within the ducting creates turbulent flow at the air volume measurement device, resulting in eddy currents or secondary flows. This, in turn, leads to extremely uneven velocity and temperature distribution at the air volume measurement device. As a result, most coal mill inlet air volume measurements are inaccurate and have poor dynamic characteristics. Sometimes, the air volume measured by the air volume measurement device and the damper opening change inversely.

[0004] Given the extremely compact layout of the cold and hot primary air ducts at the coal mill inlet, it's difficult to ensure uniformity in the flow and temperature fields at the air volume measurement device, making accurate measurement of the primary air volume at the coal mill inlet extremely challenging. Therefore, improving the uniformity of the flow and temperature fields within the primary air ducts is crucial to achieving accurate measurement of the air volume at the coal mill inlet.

[0005] The existing cold and hot air mixing device has the following shortcomings when in use: there are various obstructions in the pipeline, such as cold and hot primary air regulating valves, elbows, tapered pipes, etc., and the distance between the intersection of cold and hot air and the air volume measuring device is short, resulting in the cold and hot air not being completely and evenly mixed, making it difficult to ensure the flow field uniformity and temperature field uniformity at the air volume measuring device; the temperature of the mixed air is detected by a temperature sensor installed in the mixing pipeline, but the detection point is single, and in the case of insufficient mixing, the detection data is inaccurate. Summary of the Invention

[0006] The purpose of the present invention is to provide a non-invasive Reynolds shear layer hot and cold air mixing device to solve the problems raised in the above background technology.

[0007] To achieve the above-mentioned objectives, the present invention provides the following technical solutions: a non-invasive Reynolds shear layer cold and hot air mixing device, comprising a mixing pipe and a cold air pipe and a hot air pipe connected to the mixing pipe, the mixed flow pipe as a whole being composed of a first horizontal section, a second horizontal section and a vertical section connecting the first horizontal section and the second horizontal section, a Reynolds shear layer generator and a mixer are provided on the first horizontal section, a detection mechanism is installed on the second horizontal section, and the ends of the cold air pipe and the hot air pipe are connected to the mixed flow pipe through the Reynolds shear layer generator.

[0008] Preferably, the Reynolds shear layer generator includes a first sleeve and a first fixed frame arranged inside the first sleeve. The first sleeve is provided with a partition inside the end away from the mixer, and the partition divides the end of the first sleeve into two independent chambers. The first fixed frame is arranged at the port of the chamber, and a plurality of airfoil spoilers are provided on the inner side of the first fixed frame.

[0009] Preferably, the cold air duct and the hot air duct are respectively connected to the interior of the two chambers.

[0010] Preferably, the plane where the plurality of airfoil spoilers are located is parallel to the partition.

[0011] Preferably, the mixer includes a second sleeve and a second fixing frame arranged inside the second sleeve. A rotating shaft is installed at the center of the second fixing frame through a bearing, and a plurality of blades are fixedly arranged on the outer side of the rotating shaft.

[0012] Preferably, the detection mechanism includes a third sleeve, on which a temperature sensor and a flow sensor are installed, and the detection probes of the temperature sensor and the flow sensor are both placed inside the third sleeve.

[0013] Preferably, the connections between the first horizontal section, the second horizontal section and the vertical section are all streamlined.

[0014] Preferably, a plurality of the temperature sensors are provided, and the plurality of temperature sensors are evenly distributed on the inner wall of the third sleeve.

[0015] Preferably, a first damper and a second damper are respectively provided at the ports of the cold air duct and the hot air duct, and the first damper and the second damper are correspondingly connected to an electric drive.

[0016] Preferably, it also includes a controller, which is arranged on the outer surface of the third sleeve, the input end of the controller is electrically connected to the output end of the detection mechanism, and the output end of the controller is electrically connected to the electric drivers of the first damper and the second damper.

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

[0018] 1. By setting up a Reynolds shear layer generator and an adjustable mixer, under the synergistic effect of the Reynolds shear layer generator and the adjustable mixer, efficient mixing of cold air and hot air is achieved to ensure temperature uniformity;

[0019] 2. By setting up a detection mechanism, temperature sensors are evenly distributed on the outside of the third sleeve of the detection mechanism to monitor the temperature of the mixed air in the mixed flow duct in real time. Since multiple temperature sensors are set, multiple locations in the mixed flow duct can be monitored simultaneously, effectively ensuring the accuracy of the detection data, thereby facilitating subsequent temperature control;

[0020] 3. By setting up a controller and connecting the controller to the electric drivers of the first damper and the second damper, during use, the controller receives the detection data of the detection mechanism and regulates the first damper and the second damper respectively, thereby realizing rapid adjustment of the air volume and temperature of the mixed air. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a schematic diagram of the overall structure of the utility model;

[0022] Figure 2 This is a schematic structural diagram of the Reynolds shear layer generator of the present invention;

[0023] Figure 3 This is a schematic diagram of the installation of the airfoil spoiler of the present invention;

[0024] Figure 4 This is a schematic structural diagram of a mixer according to the present invention;

[0025] Figure 5 It is a structural diagram of the detection mechanism of the present utility model.

[0026] In the picture:

[0027] 1. Mixed flow pipeline;

[0028] 2. Cold air duct; 21. First air door;

[0029] 3. Hot air duct; 31. Second air door;

[0030] 4. Reynolds shear layer generator; 41. First sleeve; 42. First fixing frame; 43. Baffle; 44. Chamber; 45. Airfoil spoiler;

[0031] 5. Mixer; 51. Second sleeve; 52. Second fixing frame; 53. Rotating shaft; 54. Blade;

[0032] 6. Detection mechanism; 61. Third sleeve; 62. Temperature sensor; 63. Flow sensor;

[0033] 7. Controller. DETAILED DESCRIPTION

[0034] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0035] See also Figure 1-5 The utility model provides a technical solution: a non-invasive Reynolds shear layer cold and hot air mixing device, comprising a mixing pipe 1 and a cold air pipe 2 and a hot air pipe 3 connected to the mixing pipe 1. The mixed flow pipe 1 is composed of a first horizontal section, a second horizontal section and a vertical section connecting the first horizontal section and the second horizontal section. A Reynolds shear layer generator 4 and a mixer 5 are provided on the first horizontal section, and a detection mechanism 6 is installed on the second horizontal section. The ends of the cold air pipe 2 and the hot air pipe 3 are connected to the mixed flow pipe 1 through the Reynolds shear layer generator 4.

[0036] The Reynolds shear layer generator 4 includes a first sleeve 41 and a first fixed frame 42 arranged inside the first sleeve 41. A partition 43 is provided inside the first sleeve 41 at an end away from the mixer 5. The partition 43 divides the end of the first sleeve 41 into two independent chambers 44. The first fixed frame 42 is arranged at the port of the chamber 44, and a plurality of airfoil spoilers 45 are provided on the inner side of the first fixed frame 42.

[0037] The cold air duct 2 and the hot air duct 3 are communicated with the interiors of the two chambers 44 respectively.

[0038] The plane where the plurality of airfoil spoilers 45 are located is parallel to the partition plate 43 .

[0039] The mixer 5 includes a second sleeve 51 and a second fixing frame 52 disposed inside the second sleeve 51 . A rotating shaft 53 is mounted at the center of the second fixing frame 52 via a bearing. A plurality of blades 54 are fixedly disposed on the outer side of the rotating shaft 53 .

[0040] The detection mechanism 6 includes a third sleeve 61 , on which a temperature sensor 62 and a flow sensor 63 are mounted, and detection probes of the temperature sensor 62 and the flow sensor 63 are both placed inside the third sleeve 61 .

[0041] The connections between the first horizontal section, the second horizontal section and the vertical section are all streamlined.

[0042] There are multiple temperature sensors 62 , and the multiple temperature sensors 62 are evenly distributed on the inner wall of the third sleeve 61 .

[0043] A first damper 21 and a second damper 31 are respectively provided at the ends of the cold air duct 2 and the hot air duct 3 , and the first damper 21 and the second damper 31 are correspondingly connected to an electric driver.

[0044] It also includes a controller 7, which is arranged on the outer surface of the third sleeve 61. The input end of the controller 7 is electrically connected to the output end of the detection mechanism 6, and the output end of the controller 7 is electrically connected to the electric driver of the first damper 21 and the second damper 31.

[0045] Specifically, when the utility model is used, cold primary air and hot primary air are respectively transported through the cold air duct 2 and the hot air duct 3, and enter the two chambers 44 inside the Reynolds shear layer generator 4. Subsequently, under the action of the airfoil spoiler 45 in the first sleeve 41, the cold air and the hot air form a shear layer at the intersection. Due to the velocity gradient between the airflows at different temperatures, the shear layer will produce a strong turbulent effect, which is conducive to quickly and evenly mixing the cold air and the hot air. Subsequently, the cold air and the hot air are quickly mixed under the action of the mixer 5 and transported to the inlet of the coal mill.

[0046] In the above process, the temperature sensor 62 and the flow sensor 63 of the detection mechanism 6 respectively detect the temperature and flow of the mixed air inside the mixed flow duct 1 in real time, and send the detected data to the controller 7, which controls the first damper 21 and the second damper 31 respectively, thereby quickly adjusting the temperature and flow of the mixed air.

Claims

1. A non-invasive Reynolds shear layer hot and cold air mixing device, characterized in that: The invention comprises a mixed flow duct (1) and a cold air duct (2) and a hot air duct (3) connected to the mixed flow duct (1). The mixed flow duct (1) as a whole is composed of a first horizontal section, a second horizontal section and a vertical section connecting the first horizontal section and the second horizontal section. A Reynolds shear layer generator (4) and a mixer (5) are provided on the first horizontal section. A detection mechanism (6) is installed on the second horizontal section. The ends of the cold air duct (2) and the hot air duct (3) are connected to the mixed flow duct (1) through the Reynolds shear layer generator (4).

2. The non-invasive Reynolds shear layer hot and cold air mixing device according to claim 1, characterized in that: The Reynolds shear layer generator (4) comprises a first sleeve (41), a first fixing frame (42) arranged inside the first sleeve (41), a partition (43) being arranged inside the first sleeve (41) at an end away from the mixer (5), the partition (43) dividing the end of the first sleeve (41) into two independent chambers (44), the first fixing frame (42) being arranged at the port of the chamber (44), and a plurality of airfoil spoilers (45) being arranged on the inner side of the first fixing frame (42).

3. The non-invasive Reynolds shear layer hot and cold air mixing device according to claim 2, characterized in that: The cold air duct (2) and the hot air duct (3) are respectively connected to the interiors of the two chambers (44).

4. The non-invasive Reynolds shear layer hot and cold air mixing device according to claim 2, characterized in that: The plane where the plurality of airfoil spoilers (45) are located is parallel to the partition (43).

5. The non-invasive Reynolds shear layer hot and cold air mixing device according to claim 1, characterized in that: The mixer (5) comprises a second sleeve (51), a second fixing frame (52) arranged inside the second sleeve (51), a rotating shaft (53) being mounted at the center of the second fixing frame (52) via a bearing, and a plurality of blades (54) being fixedly arranged on the outside of the rotating shaft (53).

6. The non-invasive Reynolds shear layer hot and cold air mixing device according to claim 1, characterized in that: The detection mechanism (6) comprises a third sleeve (61), a temperature sensor (62) and a flow sensor (63) are mounted on the third sleeve (61), and the detection probes of the temperature sensor (62) and the flow sensor (63) are both placed inside the third sleeve (61).

7. The non-invasive Reynolds shear layer hot and cold air mixing device according to claim 1, characterized in that: The connections between the first horizontal section, the second horizontal section and the vertical section are all streamlined.

8. The non-invasive Reynolds shear layer hot and cold air mixing device according to claim 6, characterized in that: A plurality of the temperature sensors (62) are provided, and the plurality of the temperature sensors (62) are evenly distributed on the inner wall of the third sleeve (61).

9. The non-invasive Reynolds shear layer hot and cold air mixing device according to claim 1, characterized in that: A first damper (21) and a second damper (31) are respectively provided at the ends of the cold air duct (2) and the hot air duct (3), and the first damper (21) and the second damper (31) are correspondingly connected to an electric drive.

10. The non-invasive Reynolds shear layer hot and cold air mixing device according to claim 9, characterized in that: The device further comprises a controller (7), wherein the controller (7) is arranged on the outer surface of the third sleeve (61), the input end of the controller (7) is electrically connected to the output end of the detection mechanism (6), and the output end of the controller (7) is electrically connected to the electric drivers of the first damper (21) and the second damper (31).

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