Nuclear Polar Cranes: Used for Reactor Refueling and Equipment Maintenance
Nuclear Polar Cranes are applied for reactor refueling and heavy-duty equipment maintenance & installation inside the nuclear power plant reactor building. Generally installed on the circular rail above the reactor pressure vessel, they operate by rotating around the reactor center.
DGCRANE nuclear polar cranes feature high reliability and safe & stable operation. Adopting intelligent technology, the cranes deliver smoother and more efficient performance, greatly boosting work efficiency and economic benefits.
Nuclear Polar Crane Technical Advantages
Dual-hoist Dynamic Balance Control Technology
Aiming at the combined hoisting operation of 400-ton heavy-duty equipment in nuclear power plants, the crane adopts a dual frequency conversion independent drive and closed-loop speed control scheme. The PLC compares the position data of the two hoisting mechanisms in real time and performs dynamic compensation and adjustment to realize synchronous operation of double hooks.
- Synchronization deviation of lifting height: within ±30 mm
- Follow-up speed fluctuation: ≤3%
- Electric synchronization realized without rigid mechanical connection
- Stable, safe and reliable heavy-load hoisting
It effectively solves the problems of asynchronous movement, large impact and poor stability during the combined hoisting of large-scale equipment.
High-precision Closed-loop Positioning Control Technology
The bridge and trolley traveling mechanisms adopt a full closed-loop variable frequency speed regulation system. Combined with motor encoders and wheel position sensors, precise positioning control is achieved.
- 3D traveling positioning accuracy: ≤5 mm
- Master-slave synchronous control of multiple motors
- High-speed optical fiber communication
- PI parameter optimization algorithm
It ensures precise alignment and stable operation during the installation of key equipment inside the nuclear island.
Redundant Protection and Single-failure Safety Design
To meet the single failure protection requirements for nuclear power equipment, key controllers and sensors are configured with redundancy. Dual detection and real-time data comparison are carried out for core parameters including lifting position, load and rotating speed.
When abnormalities are detected, the system will automatically:
- Cut off the main power supply of motors
- Activate service brakes and safety brakes
- Achieve safe and reliable stopping
This eliminates risks of single-point failure and greatly upgrades the safety level of the system.
Drive Train Real-time Monitoring Technology
The hoisting mechanism is equipped with dual redundant encoders for speed and position. Real-time conversion and comparison of data from the motor end and drum end are conducted to implement online monitoring of the drive train operating status.
- Real-time speed deviation monitoring
- Real-time position error comparison
- Over-speed protection
- Automatic shutdown upon abnormality
It provides early warning of transmission anomalies and prevents major accidents caused by mechanical failure.
Digital Intelligent Integrated Monitoring System
Equipped with an intelligent HMI integrated monitoring platform to realize visualized and digital management of equipment operating conditions.
- Real-time display of speed, position, load and other parameters
- Graded color alarm display for synchronization deviation
- Historical fault record and traceability
- Trend curve analysis
- PLC network diagnosis
It improves operational transparency and maintenance efficiency, realizing digital and intelligent management.
Special Design of Nuclear Polar Cranes
- Adopt a relatively large safety factor to enhance crane reliability.
- The hoisting mechanism is designed with single-failure protection: when a fault occurs at any point of the hoisting drive train, the crane can still hold the load steadily.
- Equipped with multiple protection devices and special safety units.
- Fitted with anti-seismic devices to reduce the impact of seismic loads.
- Crane wheels adopt tapered treads to optimize traveling performance.
- Installed with a hook traversing mechanism to eliminate operating blind spots.
Nuclear Polar Crane Applications
- Nuclear power plant construction phase: Used for the installation of heavy-duty equipment in the reactor building, such as steam generators, reactor pressure vessels, pressurizers, lower reactor internals, upper reactor internals, and other light-load equipment.
- Nuclear power plant operation phase: Applied to reactor shutdown refueling and various hoisting services for equipment maintenance inside the reactor building.
- Nuclear power plant decommissioning phase: Used for the dismantling and cleaning of equipment and structures within the nuclear island.
