On August 12, Hubei Technology Exchange organized seven professors and experts from noted universities, design entities and engineering entities to hold an online review on the achievements of “Research on Key Technologies of Digital R&D Platform-based 12m³ Electric Shovel for Large Open Mine in Alpine Regions” conducted by China Railway Science and Industry Group (CRSIG) under CRHIC. The panel appraised the research achievements to “generally reach the internationally advanced level”.

WKH-12A 12m3 single-bucket electric front-shovel excavator (12m3 electric shovel for short) is one of the important achievements of the research. Its development success marks that, CRSIG has made a breakthrough in the foreign monopoly on the R&D technologies and key core technologies of large open mine shovels, developed the core technologies to research and manufacture electric shovels, built up a complete system for electric shovel R&D and manufacturing, and elbowed into the world’s “first camp” of electric shovel. This is of great significance for enhancing the core competitiveness of Chinese enterprises in the field of mining electric shovels.

High efficiency. Traditionally, an electric shovel will take 30 seconds to complete one operation cycle of digging, turning, loading and unloading. By developing multi-motor synchronous drive, conforming distribution technology, parallel current-sharing technology and fast mixed-frequency braking technology, the researchers has greatly shortened the acceleration and deceleration time for each operation step of electric shovel and reduced one operation cycle to merely 28 seconds. The time can be further decreased to be 26 seconds, a shark contrast to the bulky and clumsy equipment, irrespective of the operator’s normal physiological tolerance. As field test shows, a 12m3 electric shovel takes less than 2 minutes and 30 seconds to fill up a 100t ore truck, which wins recognition from the owner.

Against extreme cold. In order to ensure the 12m3 electric shovel can operate normally in alpine regions, the researchers are the first in China to engage in cold resistance design of electric shovels. The main structural parts of the equipment are made of high-strength low-alloy steel plates with low-temperature impact toughness, and take low-temperature impact test against -45°C before they leave factory. Considering that the main casting and forging materials of the equipment are made of Ni, Mo and Cr and the welding quality of special steels needs to be guaranteed, the technicians have done several tests on the welding process to eventually find one that suitable for electric shovels in alpine regions and improve the durable strength of the main structural parts in low-temperature operating conditions. In addition, the technicians configure a constant temperature warm air circulation system in the equipment cabin and electrical cabinet. In 2019, the 12m3 electric shovel applies in Yichun Luming molybdenum mine in Heilongjiang Province with success, withstanding the extreme cold weather (minimum temperature of -43.1°C) in the mine area to attest its name of “extreme equipment”. The equipment has successfully helped China Railway No.9 Group to complete more than 10 million cubic meters of stripping in 2019.

24h mentoring. With view to timely addressing equipment failure and enabling continuous operation of the equipment, the researchers have developed a visual online information system, which is the first in China to provide 24h online solution to the electric shovel operation failure. The intelligent electrical system has the functions of status monitoring and fault alarm & diagnosis, allowing it to monitor and record the operating status and operating parameters of the equipment in case of fault and to intelligently give possible cause suggestions of the fault for users to check and eliminate the fault in real time. The control system also configures the auxiliary excavation function to provide the equipment operators with the most reasonable match vales of pushing force and lifting force, helping them choose the most efficient excavation operation. Besides, the information system data is connected with the optimized digital virtual prototype to store all the real-time data of field operation in the background system, providing a direct data support for further development of the electrical shovel.