A method and structure for detecting the horizontality of a flow guide tube.

Abstract

This invention discloses a method for leveling a flow guide tube, comprising the following steps: S1, acquiring the liquid outlet distance pixel values ​​collected by different image acquisition devices; S2, calculating a conversion coefficient based on the liquid outlet distance pixel values ​​and the actual flow guide tube diameter; S3, then moving the measurement point to the X-axis measurement interval and the Y-axis measurement interval, and measuring the pixel values ​​in the four intervals respectively; S4, then using the conversion coefficient to obtain the actual distance of the object to be detected from the pixel values; S5, comparing the difference in the actual distance to determine whether the flow guide tube is level. This method uses an image acquisition device to acquire the liquid outlet distance pixel values ​​and convert them to the actual flow guide tube diameter to obtain a conversion coefficient; then, through the acquired X-axis and Y-axis measurement intervals, it uses the conversion coefficient to obtain the actual value, and compares the obtained actual value with the actual distance of the object to be detected, thereby determining whether the flow guide tube is level. This invention also discloses a structure for leveling a flow guide tube using the above method.

Description

Technical Field

[0001] This invention relates to the field of solar photovoltaic technology, and in particular to a method and structure for detecting the level of a guide tube. Background Technology

[0002] Solar energy has been widely used in modern society, not only improving the environment but also solving some energy problems. Among the uses of solar energy, photovoltaic conversion is the most widespread, which requires a large number of silicon cells, leading to a large demand for photovoltaic-grade monocrystalline silicon.

[0003] Currently, the Czochralski method for growing monocrystalline silicon is the most widely used technology for producing monocrystalline silicon. With increasing market competition and cost pressure, monocrystalline silicon manufacturers are reducing costs by lowering the price of thermal components. In order to maintain normal monocrystalline growth, a flow guide tube is needed, making the flow guide tube one of the important systems in the current Czochralski single crystal furnace.

[0004] Currently, in single crystal furnaces, the shape of the furnace cover and the angle of the observation window cannot accurately determine the levelness of the guide tube. Whether the guide tube is level is mainly determined by visual inspection, and the judgment has blind spots, resulting in low accuracy. Summary of the Invention

[0005] In view of this, the present invention provides a method for detecting the horizontality of a guide tube, which improves detection accuracy, reduces costs, and increases work efficiency.

[0006] To achieve the above objectives, the present invention provides the following technical solution:

[0007] A method for detecting the horizontal level of a flow guide tube includes the following steps:

[0008] S1. Obtain the pixel value of the liquid outlet distance acquired by different image acquisition devices;

[0009] S2. Calculate the conversion coefficient based on the pixel value of the liquid outlet distance and the actual diameter value of the guide tube;

[0010] S3. Then move the measurement point to the X-axis measurement interval and the Y-axis measurement interval, and measure the pixel values ​​of the four intervals respectively;

[0011] S4. Then, the actual distance to the detected object is obtained by using the conversion coefficient to determine the pixel value.

[0012] S5. Compare the difference in actual distance to determine whether the guide tube is level.

[0013] Preferably, in step S1, the different image acquisition devices include a first image acquisition device and a second image acquisition device distributed in a vertical direction.

[0014] Preferably, in step S2, the conversion coefficient is the ratio of the actual guide tube diameter value to the liquid outlet distance pixel value.

[0015] Preferably, in step S4, the pixel value of the liquid outlet distance can be determined based on the difference in pixel value between the reflection edge and the guide tube opening, and the actual distance value is obtained based on the pixel value and the conversion coefficient.

[0016] Preferably, in step S4, the actual distance is obtained by the ratio of the liquid surface pixel value to the conversion coefficient, and the judgment is made by the actual distance values ​​of the two intervals of the X-axis and the actual distance values ​​of the two intervals of the Y-axis.

[0017] Preferably, in step S5, if the deviation is ≤1mm, the guide tube is horizontal; if the deviation is >1mm, the levelness of the guide tube is poor; the larger the deviation, the worse the levelness of the guide tube.

[0018] A structure for detecting the horizontal level of a guide tube, employing the aforementioned method for detecting the horizontal level of a guide tube, includes: a first image acquisition device and a second image acquisition device;

[0019] The first image acquisition device and the second image acquisition device are mounted on the furnace cover.

[0020] Preferably, the first image acquisition device and the second image acquisition device are arranged at 90° intervals along the circumference of the single crystal furnace.

[0021] Preferably, both the first image acquisition device and the second image acquisition device have an oblong structure.

[0022] Preferably, the first image acquisition device and the second image acquisition device are CCD cameras.

[0023] As can be seen from the above technical solution, the method for detecting the horizontality of the guide tube provided by the present invention uses an image acquisition device to collect the pixel value of the liquid outlet distance and convert it with the actual diameter of the guide tube to obtain a conversion coefficient; then, by collecting the X-axis measurement range and Y-axis measurement range, the actual value is obtained through the conversion coefficient; the obtained actual value is compared with the actual distance of the detection object, and then it is determined whether the guide tube is horizontal.

[0024] The present invention also provides a structure for detecting the horizontal level of the guide tube. Since the above-mentioned method for detecting the horizontal level of the guide tube is adopted, it has corresponding beneficial effects, which can be referred to in the previous description and will not be repeated here. Attached Figure Description

[0025] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the 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.

[0026] Figure 1 A schematic diagram of the structure of the furnace lid and image acquisition device of the single crystal furnace provided in an embodiment of the present invention;

[0027] Figure 2 This is a cross-sectional structural schematic diagram of the guide tube inside the single crystal furnace provided in an embodiment of the present invention;

[0028] Figure 3 This is a schematic diagram of the coordinate origin provided in an embodiment of the present invention;

[0029] Figure 4 This is a schematic diagram of the X-axis measurement range and Y-axis coordinates provided in an embodiment of the present invention.

[0030] 10 is the furnace cover, 11 is the first image acquisition device, and 12 is the second image acquisition device;

[0031] 20 is the crystal rod, 21 is the lower opening of the water-cooled screen, and 22 is the lower opening of the guide tube. Detailed Implementation

[0032] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0033] The method for detecting the horizontal level of a guide tube provided in this embodiment of the invention includes the following steps:

[0034] S1. Obtain the pixel value of the liquid outlet distance acquired by different image acquisition devices;

[0035] S2. The conversion coefficient is calculated based on the pixel value of the liquid outlet distance and the actual diameter value of the guide tube. Since the actual liquid outlet distance is a fluctuating value, a reference object is needed for comparison. In this scheme, the reference object is the actual diameter value of the guide tube.

[0036] S3. Then move the measurement point to the X-axis measurement interval and the Y-axis measurement interval, and measure the pixel values ​​of the four intervals respectively. You can refer to [the relevant documentation]. Figure 3 and Figure 4 ;

[0037] S4. Then, the actual distance to the detected object is obtained by using the conversion coefficient to determine the pixel value.

[0038] S5. Compare the difference in actual distance to determine whether the guide tube is level.

[0039] The working principle and purpose of the above scheme are as follows:

[0040] This detection method uses an image acquisition device to collect pixel values ​​of the liquid outlet distance and converts them with the actual diameter of the guide tube to obtain a conversion coefficient. Then, by collecting the X-axis and Y-axis measurement intervals, the actual value is obtained using the conversion coefficient. This actual value is compared with the actual distance to the object being tested to determine whether the guide tube is level. Compared with existing technologies, this method solves the technical problem of low accuracy in judging the levelness of the guide tube by visual observation during the monocrystalline silicon manufacturing process. In practical use, this solution has advantages such as high work efficiency, high detection accuracy, and low cost.

[0041] Furthermore, in step S1, the different image acquisition devices include a first image acquisition device 11 and a second image acquisition device 12 distributed vertically, which can be referred to... Figure 1 , Figure 3 and Figure 4 It should be noted that, through this design, the first image acquisition device 11 and the second image acquisition device 12 can respectively acquire pixel values ​​in the X-axis measurement range and pixel values ​​in the Y-axis measurement range. It is understood that different image acquisition devices acquiring pixel values ​​of the liquid outlet distance from their respective viewpoints can obtain conversion coefficients in different directions; when the image acquisition devices are evenly distributed around the circumference of the guide tube, their conversion coefficients should be the same.

[0042] Furthermore, in step S2, the conversion coefficient is the ratio of the actual guide tube diameter value to the liquid outlet distance pixel value; it should be noted that this conversion coefficient is not a fixed value, and the value will vary depending on the actual scenario.

[0043] In step S3, the origins of the X and Y axes are moved to the center of the aperture used by the image acquisition device to capture the seed crystal. For example... Figure 3 As shown, the lower half of the crescent moon in the middle is the liquid image of the seed crystal. The image acquisition device can automatically capture its aperture and move the origin of the X-axis and Y-axis downwards to its center, thus completing the coordinate system correction.

[0044] Preferably, in step S4, the pixel value of the liquid outlet distance can be determined based on the difference in pixel value between the reflection edge and the guide tube opening, and the actual distance value is obtained based on the pixel value and the conversion coefficient.

[0045] Specifically, in step S4, the actual distance is obtained by the ratio of the liquid surface pixel value to the conversion coefficient, and then judged based on the actual distance values ​​of the two intervals along the X-axis and the two intervals along the Y-axis. This interval represents the reflection of the lower opening of the guide tube on the liquid surface, such as... Figure 4 The crescent shape at the indicated location.

[0046] In this embodiment, in step S5, if the deviation is ≤1mm, the guide tube is horizontal; if the deviation is >1mm, the levelness of the guide tube is poor. The larger the deviation, the worse the levelness of the guide tube.

[0047] This invention also provides a structure for detecting the horizontal level of a guide tube, using the method described above, including: a first image acquisition device 11 and a second image acquisition device 12;

[0048] The first image acquisition device 11 and the second image acquisition device 12 are disposed on the furnace cover 10, and their structures can be referred to as follows. Figure 1 With this design, images are acquired by the first image acquisition device 11 and the second image acquisition device 12.

[0049] Furthermore, the first image acquisition device 11 and the second image acquisition device 12 are arranged at 90° intervals along the circumference of the single crystal furnace, and their structure can be referred to Figure 1 With this design, the pixel values ​​of the X-axis measurement range and the Y-axis measurement range can be collected by the image acquisition device.

[0050] Specifically, both the first image acquisition device 11 and the second image acquisition device 12 have an oblong structure, and their structures can be referred to as follows: Figure 1 This design allows for expansion of the range on the X and Y axes, making it more advantageous to collect pixel values ​​in the X-axis and Y-axis measurement ranges.

[0051] Preferably, the first image acquisition device 11 and the second image acquisition device 12 are CCD cameras; CCD cameras have the characteristics of low noise, high sensitivity, uniform pixel response and high spatial resolution, which are in line with the working principle.

[0052] The following is a further description of this solution with reference to specific embodiments:

[0053] This scheme mainly uses dual CCD cameras and vertical measurement auxiliary lines to measure the size of the lower opening of the guide tube and the reflection of the guide tube at four points. By comparing the measurement values ​​at the four points, it can be determined whether the guide tube is horizontal.

[0054] Furthermore, this solution uses two CCD cameras installed at the furnace observation window to detect the values ​​of four points in the X and Y axes to determine whether the guide tube is horizontal.

[0055] Furthermore, the actual diameter value is the true value of the item, that is, the size value of the guide tube after it has been designed and processed, and the liquid outlet distance pixel value is the value generated by the camera itself based on the pixels of the measured area. The ratio of these two values ​​is the conversion coefficient.

[0056] The pixel value of the liquid outlet distance can be determined by the difference in pixel value between the reflection edge and the guide tube opening. The actual distance value can be obtained based on the pixel value and the conversion coefficient.

[0057] The camera distribution direction is mainly determined by the distribution of the furnace platform structure. The vertical distribution can be seen as the distance between two different directions in the cross direction. The horizontality is determined by the distance values ​​at the four points in the cross direction.

[0058] The vertical distribution of cameras is mainly for measuring the distance values ​​at four points in the cross direction, which cannot be satisfied by a single horizontal or vertical direction.

[0059] The camera is at a certain angle to the axis. The camera mainly captures the image of the liquid surface as the reflection of the bottom of the guide tube. The camera has a waist-shaped structure. The front of the furnace platform is the reference direction of the field of view. The left and front sides are the camera placement directions. The rear side mainly has columns and lifting mechanisms, so it is impossible to place the camera there.

[0060] This scheme mainly involves setting up one set of CCD cameras, the specific structure of which is as follows: Figure 1 The actual distance is obtained by the ratio of the liquid surface pixel value to the conversion coefficient (the conversion coefficient ranges from 1 to 1.5, and varies depending on the actual measurement position coefficient). The actual distance values ​​at four points are used to judge whether the guide tube is level. If the deviation is ≤1mm, the guide tube is level. If the deviation is >1mm, the guide tube is not level. The larger the deviation, the worse the level of the guide tube.

[0061] First, this method measures the pixel values ​​using the camera pixel function of two vertically distributed CCD cameras. A conversion coefficient is calculated by comparing the pixel value at the lower opening of the guide tube with the actual value; this conversion coefficient is between 1 and 1.5. Then, the measurement point is moved to the X-axis and Y-axis measurement intervals, and the pixel values ​​in each of the four intervals are measured. The actual distance is then calculated using the conversion coefficient, and the difference between the actual distance and the actual distance is compared to determine whether the guide tube is level. Figure 3 and Figure 4 These are simulated images of the first and second cameras inside the furnace, respectively.

[0062] This technical solution effectively solves the blind spot of not being able to determine whether the guide tube is horizontal, and further improves the symmetry and consistency of the temperature field in the current single crystal pulling process.

[0063] In a set of actual test data: the diameter of the guide tube is φ280mm. The calibration line at the coordinate axis is positioned to be tangent to the guide tube by modifying the coordinate coefficient value. The pixel value at this time is read as: 48; then the calibration line is moved to the reflection position and the pixel value at this time is read as: 20; the scaling factor is calculated as: X=(48-20) / 48=0.583.

[0064] The pixel value on the left side of the X-axis is 45, and the actual value is: 45 * 0.583 = 26.235;

[0065] The pixel value on the right side of the X-axis is 46.5, and the actual value is: 46.5 * 0.583 = 27.110;

[0066] The Y-axis can be calculated similarly.

[0067] Advantages of this technical solution:

[0068] This solution calculates the conversion coefficient by comparing the pixel value detected by the camera at the lower opening of the guide tube with the actual diameter of the guide tube. The conversion coefficient is then used to calculate the difference between the calculated and actual values ​​by comparing the pixel values ​​at the liquid outlet distance of the first and second cameras.

[0069] This solution uses a set of cameras to measure and calculate four distances in the vertical direction of the lower opening of the guide tube by using pixel values ​​and conversion coefficients. This solution can determine whether the guide tube is horizontal, greatly improving the consistency and symmetry of the thermal field, and has guiding significance for process selection.

[0070] Key points and areas to be protected in this plan:

[0071] This solution achieves the horizontal detection function of the guide tube by setting up a set of cameras in the vertical direction and introducing a distance test calculation logic. This calculation logic mainly determines the true distance value by using the camera pixel value and the conversion coefficient.

[0072] The protection point lies in the camera's orientation, calculating distance using pixel values ​​and conversion coefficients, and using the distance value to determine the horizontal detection function of the guide tube.

[0073] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. The same or similar parts between the various embodiments can be referred to each other.

[0074] The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A method for detecting the horizontal level of a guide tube, characterized in that, Including the following steps: S1. Obtain the pixel value of the liquid outlet distance acquired by different image acquisition devices; S2. A conversion coefficient is calculated based on the liquid outlet distance pixel value and the actual guide tube diameter value. The conversion coefficient is the ratio of the actual guide tube diameter value to the liquid outlet distance pixel value. S3. Move the measurement point to the X-axis measurement interval and the Y-axis measurement interval, and measure the pixel values ​​of the four intervals respectively; S4. The actual distance to the detected object is obtained by using the conversion coefficient based on the pixel values ​​of the four intervals, including: determining the pixel value of the liquid outlet distance based on the difference between the pixel value of the reflection edge of the lower opening of the guide tube and the lower opening of the guide tube, and obtaining the true distance value based on the pixel value and the conversion coefficient. S5. Compare the difference in the actual distance to determine whether the guide tube is horizontal.

2. The method for detecting the horizontal level of the guide tube according to claim 1, characterized in that, In step S1, the different image acquisition devices include a first image acquisition device (11) and a second image acquisition device (12) distributed in a vertical direction.

3. The method for detecting the horizontal level of the guide tube according to claim 1, characterized in that, In step S3, the origin of the X-axis and Y-axis is moved to the center of the capture aperture of the seed crystal by the image acquisition device.

4. The method for detecting the horizontal level of the guide tube according to claim 1, characterized in that, In step S4, the actual distance is obtained by the ratio of the liquid surface pixel value to the conversion coefficient, and the judgment is made by the actual distance values ​​of the two intervals of the X-axis and the two intervals of the Y-axis.

5. The method for detecting the horizontal level of the guide tube according to claim 1, characterized in that, In step S5, if the deviation is ≤1mm, the guide tube is horizontal; if the deviation is >1mm, the levelness of the guide tube is poor. The larger the deviation, the worse the levelness of the guide tube.

6. A structure for detecting the horizontal position of a flow guide tube, characterized in that, The method for horizontal detection of the guide tube as described in any one of claims 1-5 includes: a first image acquisition device (11) and a second image acquisition device (12). The first image acquisition device (11) and the second image acquisition device (12) are disposed on the furnace cover (10).

7. The structure for horizontal detection of the guide tube according to claim 6, characterized in that, The first image acquisition device (11) and the second image acquisition device (12) are arranged at 90° intervals along the circumference of the single crystal furnace.

8. The structure for horizontal detection of the guide tube according to claim 6, characterized in that, Both the first image acquisition device (11) and the second image acquisition device (12) have a waist-shaped structure.

9. The structure for horizontal detection of the guide tube according to claim 6, characterized in that, The first image acquisition device (11) and the second image acquisition device (12) are CCD cameras.

Images