CN106955873B - Laser decontamination online correction auxiliary device, laser decontamination device and decontamination method - Google Patents

Abstract

The invention discloses an online correction auxiliary device for laser decontamination, a laser decontamination device and a decontamination method. The online correction auxiliary device includes a housing, a measurement laser output module arranged in the housing, a power adjustment module, and a detection signal collection target surface And the signal extraction and processing module, the housing is provided with anti-radiation window, the measurement laser emitted by the measurement laser output module passes through the anti-radiation window, and passes through the anti-radiation window after being reflected on the surface of the object to be decontaminated, and is collected in the detection signal collection For the target surface, the signal extraction processing module extracts the detection signal to collect the received power signal of the target surface, and forwards it to the power adjustment module, and the power adjustment module adjusts the power gain of the measurement laser output module according to the received power signal. The online correction auxiliary device of the present invention uses power self-gain and narrow-band filter technology to complete accurate extraction of ranging signals, and then assists the decontamination device to realize automatic correction on the basis of a preset theoretical trajectory.

Description

Laser decontamination online calibration auxiliary device, laser decontamination device and decontamination method

technical field

The invention relates to the field of laser decontamination, in particular to an online correction auxiliary device for laser decontamination, a laser decontamination device and a decontamination method.

Background technique

During the operation of nuclear power plants, the corrosion products of structural materials and the primary coolant are activated by neutrons to form radioactive substances, which are transmitted, distributed, and deposited on the surfaces of pipes, valves, and pumps in the system. With the increase of the service time of nuclear power plants, the accumulation of these radioactive materials increases day by day, which leads to the enhancement of the radiation field of the system and the increase of the radiation dose of the staff. Therefore, regular or irregular radioactive decontamination is required to ensure the safe operation of the power station and reduce the collective radiation dose of operating personnel. With the large-scale construction and operation of domestic nuclear power plants, more and more components need to be radioactively decontaminated.

In the current technology, the scheme of using laser decontamination has been initially proposed, but in the existing laser decontamination process, the emission distance of the cleaning laser is one of the important influencing parameters related to the decontamination effect, and under this background, it is necessary to realize The precise measurement of the distance has the following difficulties: First, all external interfaces will have anti-radiation windows to protect the internal components of the equipment during laser decontamination under radioactive conditions, and the anti-radiation windows will reduce the laser feedback to the detection target surface. power, resulting in a substantial increase in the false alarm rate, and at the same time, the transmittance of the anti-radiation window will also change with the absorption of radiation; secondly, there will be a lot of light interference on the surface of the equipment to be detected during the cleaning process, including cleaning lasers, laser Reflected stray light when interacting with materials, etc., and the power of these background lights is much higher than the laser power for detection. To sum up, referring to FIG. 1 , the laser displacement sensor used for trajectory planning in the prior art cannot perform accurate distance measurement in the above-mentioned environment.

Contents of the invention

In view of the above, it is necessary to provide a laser decontamination online calibration auxiliary device, a laser decontamination device and a decontamination method, which uses power self-gain and narrow-band filtering technology to complete the accurate extraction of ranging signals, and then assists the decontamination device in the preset The automatic correction is realized on the basis of the theoretical trajectory. Technical scheme of the present invention is as follows:

On the one hand, the present invention provides a laser decontamination online calibration auxiliary device, including a housing, a measurement laser output module arranged in the housing, a power adjustment module, a detection signal collection target surface and a signal extraction processing module. The housing is provided with a radiation-resistant window, and the measurement laser emitted by the measurement laser output module passes through the radiation-resistant window, passes through the radiation-resistant window after being reflected by the surface of the object to be decontaminated, and is collected on the detector. The signal collection target surface, the signal extraction processing module extracts the detection signal to collect the received power signal of the target surface and performs signal processing, and forwards the processing result to the power adjustment module, and the power adjustment module is based on the processing result of the received power signal Perform power gain adjustment on the measurement laser output module.

Further, the device further includes a narrowband filter module, and the narrowband filter module is arranged between the detection signal collection target surface and the anti-radiation window.

Further, the central wavelength of the narrowband filter module is equal to the measurement laser wavelength of the measurement laser output module.

Further, the measuring laser output module is a blue laser emitter.

Further, the signal extraction processing module includes a digital filter, and the digital filter is a narrow-band band-pass filter set for the blue-ray band.

Further, the anti-radiation window is made of leaded glass or other anti-radiation transparent materials.

Further, the device is fixedly connected to the cleaning laser transmitter, and the cleaning laser emitted by the cleaning laser transmitter hits the area of the surface of the object to be decontaminated and the measurement laser emitted by the measurement laser output module hits the surface of the object to be decontaminated. Areas on the surface of an object coincide.

In another aspect, the present invention provides a laser decontamination device with an online calibration function, the laser decontamination device includes a cleaning laser emitter and the above-mentioned online calibration auxiliary device for laser decontamination.

In another aspect, the present invention provides a laser decontamination method using the above-mentioned laser decontamination device, comprising the following steps:

S1. The calibration auxiliary device performs laser ranging under the condition that the power adjustment module continuously adjusts the power of the measurement laser output module;

S2. According to the target distance and the laser ranging result, correct the upper and lower positions of the calibration auxiliary device until the laser ranging result is consistent with the target distance;

S3. Turn on the cleaning laser transmitter to perform laser decontamination.

Further, the method further includes: moving the laser decontamination device according to a preset theoretical trajectory, and repeatedly performing steps S1-S3.

The present invention has the following advantages:

a. Laser ranging real-time correction technology during the cleaning process: during laser decontamination, the distance between the laser window and the surface of the component is collected in real time through the laser rangefinder, and automatic correction is realized on the basis of the preset theoretical trajectory;

b. Power self-gain and narrow-band filter technology are used in the ranging process to improve the accuracy of ranging.

Description of drawings

Fig. 1 is the structural representation of laser decontamination device in the prior art;

2 is a schematic structural view of a laser decontamination device provided by an embodiment of the present invention;

Fig. 3 is a schematic structural diagram of an online calibration auxiliary device for laser decontamination provided by an embodiment of the present invention;

Fig. 4 is a schematic diagram of the trajectory relationship for automatic correction on the basis of the theoretical trajectory in the laser decontamination process provided by the embodiment of the present invention;

Fig. 5 is a flowchart of a laser desmearing method provided by an embodiment of the present invention.

Among them, the reference signs are: 1-housing, 11-radiation-resistant window, 2-measurement laser output module, 3-power adjustment module, 4-detection signal collection target surface, 5-signal extraction and processing module, 6-narrowband filter Module, 7 - cleaning laser emitters.

Detailed ways

The technical solutions of the present invention will be further described below in conjunction with the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described here are only used to explain the present invention, not to limit the present invention.

The laser decontamination online calibration auxiliary device provided by the embodiment of the present invention can be flexibly installed on the existing laser decontamination equipment to provide accurate distance measurement information for the laser decontamination equipment and improve the decontamination effect of the laser decontamination equipment. It is flexible and has a large market prospect.

Example 1

The power of the detection laser is low, and it usually faces the object under test directly. After there is an anti-radiation window in the middle, the power of the laser fed back to the detection target surface will be reduced, resulting in a significant increase in the false alarm rate. At the same time, the transmittance of the anti-radiation window will also increase with the changes due to the absorption of radiation. In view of the fact that the anti-radiation window absorbs and changes the detection laser, it is necessary to be able to independently adjust the laser power of the laser displacement sensor according to the actual situation to ensure accurate and stable trajectory information, see Figure 4. For the loss, the signal optical power self-gain technology is adopted, and the output laser power is actively continuously adjusted according to the signal of the received power on the detection target surface to ensure the accuracy of the detection signal. In one embodiment of the present invention, a laser is provided Decontamination online correction auxiliary device, as shown in Figure 3, the laser decontamination online correction auxiliary device includes a housing 1, a measurement laser output module 2 arranged in the housing 1, a power adjustment module 3, a detection signal collection The target surface 4 and the signal extraction processing module 5, the housing 1 is provided with an anti-radiation window 11, the measurement laser emitted by the measurement laser output module 2 passes through the anti-radiation window 11, and is placed on the surface of the object to be decontaminated After being reflected, it passes through the anti-radiation window 11 and is collected on the detection signal collection target surface 4 . Preferably, the anti-radiation window 11 must meet the requirements of the anti-radiation index, and the anti-radiation window 11 is made of leaded glass or other anti-radiation transparent materials, and the laser decontamination online correction auxiliary device in this embodiment outputs Lasers need to travel to and from radiation hardened windows and work against strong optical backgrounds.

The power adjustment module 3 realizes power self-gaining, specifically as follows: the input end of the power adjustment module 3 is connected with the output end of the signal extraction processing module 5, the output end is connected with the measurement laser output module 2, and the signal extraction The input end of the processing module 5 is connected to the detection signal collection target surface 4, and the propagation path of the light is: the measuring laser output module 2 emits a ranging laser, and the ranging laser passes through the anti-radiation window 11 from the housing 1 to reach The reflective surface is reflected, reversely passes through the anti-radiation window 11 and enters the housing 1, and is finally absorbed by the detection signal collection target surface 4, and the signal extraction processing module 5 extracts the received power signal of the detection signal collection target surface 4 And do signal processing, and forward the processing result to the power adjustment module 3, the power adjustment module 3 performs power gain adjustment on the measurement laser output module 2 according to the processing result of the received power signal, and the specific adjustment method includes: The received power is compared with the ideal received power value to obtain a power deficit difference, and a corresponding power gain adjustment is performed according to the power deficit, so that the received power signal of the detection signal collection target surface 4 is kept in a stable state.

During the cleaning process of the equipment, there will be a lot of light interference on the surface to be detected, including the cleaning laser, the reflected stray light when the laser interacts with the material, etc., and the power of these background lights is much higher than the power of the detection laser. To meet the requirement of extracting weak signals under such a strong background, it is necessary to introduce differentiated wavelength management technology to complete the accurate extraction of signals. In a preferred embodiment of the present invention, wavelength gating technology is adopted, specifically: the laser decontamination online correction auxiliary device further includes a narrow-band filter module 6, and the narrow-band filter module 6 is arranged on the detection signal collection target surface 4 and the anti-radiation window 11, and the central wavelength of the narrow-band filter module 6 is equal to the measurement laser wavelength of the measurement laser output module 2, so that the measurement laser can be passed through to the greatest extent and light of other wavelengths can be prevented from passing through, effectively Background light interference is shielded.

On the other hand, for the requirement of signal extraction under strong background light interference, most of the laser cleaning and decontamination laser wavelengths are in the 1064nm band, and the blue light laser ranging is used to avoid wavelength interference, that is, the measurement laser output module 2 is a blue light laser transmitter; The signal extraction processing module 5 is provided with a software digital filter, and the software digital filter is a narrow-band band-pass filter set for the blue light band, further realizing the extraction of weak signals in a strong background.

Further, the device is fixedly connected to the cleaning laser transmitter, and the cleaning laser emitted by the cleaning laser transmitter hits the area of the surface of the object to be decontaminated and the measurement laser emitted by the measurement laser output module 2 hits the area to be decontaminated. Areas on the surface of the soiled object coincide.

Example 2

In one embodiment of the present invention, a laser decontamination device with online correction function is provided. Referring to FIG. The cleaning laser emitter is fixedly connected with the laser decontamination online correction auxiliary device, and the cleaning laser emitted by the cleaning laser emitter hits the area of the surface of the object to be decontaminated and the measurement laser emitted by the measurement laser output module 2 hits The areas on the surface of the object to be decontaminated coincide.

In practical applications, what needs to be controlled is the distance from the cleaning laser transmitter to the laser decontamination surface. During the laser decontamination process, the cleaning laser has an optimal emission distance, that is, when the distance from the cleaning laser transmitter to the laser decontamination surface satisfies the required When the optimal emission distance is mentioned above, it has the optimal decontamination effect accordingly. When the actual distance is less than the optimal emission distance, most of the energy consumption of the laser is reflected on the decontamination surface, resulting in less energy remaining on the decontamination surface. The optimal effect of cleaning and decontamination cannot be reached; when the actual distance is greater than the optimal emission distance, the energy of the laser is mainly consumed in the journey from the emitter to the decontamination surface, and reaches the decontamination surface The remaining energy of the cleaning laser is not enough to achieve the optimal effect of cleaning and decontamination. Therefore, the focal length alignment of the cleaning laser emitter plays a vital role in the effect of laser cleaning, and the focal distance of the cleaning laser emitter Through the connection between the cleaning laser transmitter and the laser decontamination online calibration auxiliary device, it is transformed into controlling the distance from the cleaning laser transmitter to the laser decontamination surface by controlling the distance from the calibration auxiliary device to the laser decontamination point.

At the same time, an embodiment of the present invention provides a laser decontamination method using the above-mentioned laser decontamination device, see FIG. 5, including the following steps:

S1. The calibration auxiliary device performs laser ranging under the condition that the power adjustment module continuously adjusts the power of the measurement laser output module;

S2. According to the target distance and the laser ranging result, correct the upper and lower positions of the calibration auxiliary device until the laser ranging result is consistent with the target distance;

S3. Turn on the cleaning laser transmitter to perform laser decontamination.

Wherein, the target distance in step S2, that is, when the ranging result of the calibration auxiliary device satisfies the target distance, correspondingly, the cleaning laser reaches the above-mentioned optimal emission distance, and then achieves the optimal decontamination effect.

Execute the above steps S1-S3, that is to complete the cleaning of a decontamination point, according to the planned path trajectory, the path trajectory is shown in Figure 4, move the laser decontamination device, and repeat the execution of steps S1-S3, then the cleaning plan pre-determined Set the next decontamination point on the theoretical trajectory.

The above is only a preferred embodiment of the present invention, and does not limit the scope of its patents. Any equivalent structure or equivalent process transformation made by using the description of the present invention and the contents of the accompanying drawings is directly or indirectly used in other related technical fields. All are included in the scope of patent protection of the present invention in the same way.

Claims (6)

1. A laser decontamination online correction auxiliary device is characterized by comprising:

casing (1), set up in measurement laser output module (2), power adjustment module (3), detection signal in casing (1) collect target surface (4) and signal extraction processing module (5), the device still includes narrowband filtering module (6), be equipped with anti-radiation window (11) on casing (1), narrowband filtering module (6) set up between detection signal collection target surface (4) and anti-radiation window (11), the central wavelength of narrowband filtering module (6) with the measurement laser wavelength of measuring laser output module (2) equals, measurement laser output module (2) are blue laser emitter, the device is used at background optical power and is higher than in the background light of the laser power of measurement laser output module (2), the measurement laser that measurement laser output module (2) launched passes anti-radiation window (11), and pass after waiting to remove the filth reflection anti-radiation window (11), and collect in detection signal collects target surface (4), signal extraction processing module (5) includes digital filter, digital filter is for the narrowband signal extraction processing module (5) the collection target surface (4) of collection, and the processing module (5) includes the receiving signal of bandpass signal: comparing the received power signal with an ideal power value to obtain a power loss difference value, and forwarding a processing result to a power adjusting module (3), wherein the power adjusting module (3) adjusts the power gain of the measurement laser output module (2) according to the processing result of the received power signal, and the method comprises the following steps: and adjusting power gain according to the power loss difference value to keep the received power signal of the detection signal collection target surface (4) in a stable state.

2. The device according to claim 1, characterized in that the radiation-resistant window (11) is made of leaded glass or other radiation-resistant transparent material.

3. The device according to claim 1 or 2, characterized in that the device is fixedly connected with a cleaning laser emitter (7), and the area of the surface to be decontaminated, which is struck by the cleaning laser emitted by the cleaning laser emitter (7), coincides with the area of the surface to be decontaminated, which is struck by the measuring laser emitted by the measuring laser output module (2).

4. A laser decontamination device with an online correction function, which is characterized by comprising a cleaning laser transmitter and the online correction auxiliary device for laser decontamination as claimed in any one of claims 1-3.

5. A laser desmear method using the laser desmear device of claim 4, characterized by the steps of:

s1, a correction auxiliary device carries out laser ranging under the condition that a power adjusting module carries out continuous power adjustment on a measurement laser output module;

s2, according to the target distance and the laser ranging result, performing vertical position correction on the correction auxiliary device until the laser ranging result is consistent with the target distance;

and S3, opening the cleaning laser transmitter to perform laser decontamination.

6. The method of claim 5, further comprising:

and moving the laser decontamination device according to a preset theoretical track, and repeatedly executing the steps S1-S3.

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