IT02S, is JRT new product in the early 2019, which is a single-point LiDAR sensor, also called tof distance sensor. With a micro size of 46x17x7mm, customers can widely use in many Laser Measurement Solutions. The lidar distance sensor can measure 12m short-range with high frequency up to 100hz. It's great for Unmanned Aerial Systems. If you need us send you data sheet and spec for this products, offering sample as well, pls tell us, thank you.
Accuracy
+/-8cm@ 0.1~3.5m
Measuring Unit
cm
Measuring Range (without Reflection)
0.1-12m
Measuring Time
0.1~3 seconds
Measuring Frequency
100 Hz
Laser Class
Class II
Laser Type
650nm, <1mw, red
Weight
About 5g
Voltage
DC2.5V~+3.5V
Serial Level
TTL 3.3V
Size
46*17*7mm
Operating Temperature
0-40 ℃ (32-104 ℉ )
Storage Temperature
-25~60 ℃ (-13~140 ℉)
2D Laser Distance Sensor,2D Lidar Sensors,Tof Lidar Distance Sensor, Flight Distance Sensor Chengdu JRT Meter Technology Co., Ltd , https://www.cdtoflidarsensor.com
2, the cause of the incident 2.1, October 2002 #1 unit overhaul, #4 high-profile door disintegration found that the door stem head (where there is no thread, but the processing has a stop cross hole, Ñ„12mm, L = 120mm) occurs lateral fracture. Because the stop horizontal pin (referred to as the horizontal pin) did not come out, so the #4 high-profile door was stable before the overhaul, no abnormalities.
2.2. Analysis of the causes of door head breakage 2.2.1. Stress. During long-term operation, steam generates axial periodic exciting force on the door stem, and the door stem and the connecting thread portion are prone to fatigue damage.
2.2.2, processing technology. The cross-pin hole of the door head is drilled and then reamed. The edge of the hole is blade-shaped, forming a typical stress concentration point. Once the crack is formed, it will rapidly develop into a fracture.
2.2.3, material. Door rod material 2Cr12NiMoWV, working at high temperature, in order to increase its resistance to high temperature oxidation, the surface has been specially nitrided to form a layer of nitrogen iron compound with a thickness of about 0.5mm, which has great hardness, wear resistance and oxidation resistance. Increase, the corresponding brittleness increases, and the toughness decreases.
2.2.4. Improper assembly process.
Ha steam plant high-profile door assembly drawing process requirements: cold installation, the door rod screwed into the guide sleeve, you need to apply 152N * M torsion force on the door rod, and then load the horizontal pin. That is, the cold door is required to be fully tightly contacted with the guide sleeve after the cold installation, and no gap is allowed. In the hot state operation, since the door rod is wrapped inside the guide sleeve and the temperature is higher than the guide sleeve, the axial linear expansion amount is larger than the guide sleeve, and the above-mentioned tight force cooperation can still be ensured. Therefore, when the door rod is in hot state, the door rod is subjected to the axial exciting force of the steam, and the force is directly transmitted to the guide sleeve, so that the connecting thread of the door rod is not affected by the exciting force, because the connecting thread portion is more likely to occur. Damaged stress concentration points, thus preventing fatigue damage of the threads. The actual situation is not the case. The six high-profile doors have different degrees of non-compliance with the technical requirements. That is, when the door is closed in the cold state, after the 152N*M torque is applied, the horizontal pin hole of the door rod and the horizontal pin hole of the guide sleeve are misaligned. Phenomenon, the horizontal pin cannot be loaded smoothly. In order to install the cross pin smoothly, the door rod must be slightly retracted. If the cross pin hole is 2mm and the door rod connection thread is M50*2, the door rod needs to exit about 0.025mm, that is, the door head and the guide sleeve are 0.025. The gap of mm, which does not meet the technical requirements of the tight fit. If the maintenance personnel neglect the assembly technical requirements, the labor saving and sloppy installation will leave a safety hazard.
The two main reasons for the misalignment of the cross pin hole: a part of the factory processing size does not meet the technical accuracy requirements; b door rod long-term operation in high temperature, under stress, the connecting thread is subjected to tensile stress, compressive stress, vibration fatigue damage and high temperature Oxidation and other effects, the surface is deformed and defective, and the assembly gap changes accordingly.
2.2.5, horizontal pin deformation. The horizontal pin is slightly deformed after being stressed, and it is not replaced during maintenance. When the installation is forcibly installed, the pin hole has a large pressing force on the edge of the pin hole, and the pin hole edge is further deteriorated, and the possibility of cracking Sharply increased.
2.2.6, impact stress. The unit often performs DEH mixed-proof test, large interlock test, over-speed test during start-up and emergency stop during operation. The high-profile door will close quickly within 0.3~0.5 seconds. The design is due to the high-profile door and valve disc. There is no buffer spring structure (such as installed inside the high pressure main valve spool), which causes the door rod to be subjected to multiple strong impacts, and the impact stress of the door head is particularly serious, which further aggravates the crack of the cross pin hole.
3. Countermeasures: Replace the new door lever. In view of the fact that the transverse pin hole of the old guide sleeve may be drilled again, the inner diameter may be enlarged by the drill bit or the drill bit may be offset to make the cross pin hole invalid. The assembly size of the cross pin does not meet the requirements, and it is decided to rework the cross pin hole, and the position is 20 mm below the original hole. At the same time, the new door rod and the guide sleeve are cold-installed and the drilling process is completed once.
4. The development of the event 4.1. On April 8, 2003, the operating personnel found that the #1 machine #4 high-profile door has a degree of opening on the valve (the main control monitor screen shows that the LVDT valve opening feedback has an indication), and the valve after the closing command is issued However, there is no response. It is suspected that the servo valve of the actuator is malfunctioning and requires the maintenance personnel to handle it. The machine inspector closed the oil inlet cut-off door and found that the oil motive did not close. Then the quick unloading valve was opened to unload the oil. The oil motive still did not close. When the steam side actuator was inspected, it was found that there was a pin on the high-profile door cover. After that, it is confirmed that the horizontal pin of the door rod and the guide sleeve is disengaged, and the door rod is rotated from the guide sleeve to move downward to close the intake steam.
4.2. Reason analysis 4.2.1 After the horizontal pin is installed, it must be flushed and riveted at both ends of the horizontal pin hole. Due to the high hardness of the material of the door bar sleeve, the sealing and riveting is difficult, and the deformation of the sealing and riveting point is small, which fails to play very much. Good sealing effect.
4.2.2, the length of the cross pin and the length of the pin hole are almost the same, the room for sealing and riveting is small, which makes the sealing riveting difficult. If the cross pin is longer than the pin hole, it cannot be sealed.
4.2.3. Because of the multiple sealing and riveting around the guiding pin hole, the edge base material has more defects and it is difficult to seal the rivet.
4.2.4 The key reason is that in the original assembly design, the guide pin hole is clamped by the lever arms on both sides, that is, the pin is viewed from the outside. Due to the cover of the lever arm, only half of the cross section of the cross pin can be seen. The idea can be understood as that when the pin is loosened for various reasons and attempts to move to one side, it will hit the lever arm and stop after moving a small displacement. In the overhaul, the cross hole of the reworked pin is moved 20mm down, and the cross pin is just separated from the protection of the lever arm. During the operation, the cross pin can smoothly escape and cause the valve stem to move down to close the valve.
5. Process step 5.1, the unit keeps running state, single valve operation mode, the load is limited to 220MW or less, and the #4 high-profile door oil engine oil inlet cut-off door is closed to cut off the oil circuit.
5.2. Remove the coupling pin of the oil motive and the lever arm, first use the jack to support the lever arm, and insert a suitable spacer (square steel) into the lower clearance of the accumulator spring.
5.3. Remove the pull-down spring, then remove the jack, remove the connecting pin of the lever arm and the guide sleeve and the rear support, and remove the lever arm to make the guide sleeve completely exposed.
5.4. Because the valve butterfly is in the closed state, there is a huge steam pressure difference between the valve and the valve. The valve butterfly is pressed tightly on the bottom port, and the door rod does not move easily. At this time, the guide sleeve is rotated clockwise until the pin hole is aligned. Reload the pins and weld the seals firmly to restore the rest of the joints.
5.5. Closely monitor the load change, open the oil engine oil inlet cut-off door, and the #4 high-profile door is put into operation, and the lower block of the accumulator spring is removed.
6. Reflection 6.1. The maintenance personnel must have a comprehensive understanding and mastery of the structure and principle of the equipment, and require specific details. Any changes or changes to equipment (especially those imported or imported from foreign technology) must be demonstrated by a professional technician, and any unproven behavior will pay an undue price.
6.2. The perfect high-profile door maintenance process is the precondition for ensuring its long-term safe operation, and the quality of personnel has a dominant position. Further strengthening the technical training of maintenance personnel and improving the overall skill level should be the current important concerns, and only in this way can the quality of equipment maintenance be ensured.
IT02S Mini Tof Sensor Module Diagram
Parameters of IT02S:
IT02S – the High performance-price ratio measurement solution
* low power consumption of single transmit and single receive
* small size: 46*17*7mm
* low cost
* proffessional techinical support
1. Introduction: Hebei Xibaipo Power Generation Co., Ltd. has installed capacity of 4×300MW, Haqi N300-16.7/537(538)/537(538), subcritical, single-shaft, condensing steam turbine, high-pressure cylinder steam inlet. It is controlled by two high-pressure main valves and six high-pressure regulating doors (referred to as high-profile doors). The high-profile door operation mode adopts single valve or sequence valve according to the load. The #1 unit was put into operation in December 1993. After three major repairs and six minor repairs, the last overhaul was October 2002.