As an important part of China's comprehensive transportation system, inland waterway shipping carries about 1/6 of the freight volume and serves as the "capillaries" of bulk commodity logistics. Its green and intelligent transformation is directly related to the high-quality development of the water transportation industry and the achievement of the "dual carbon" goals. Currently, 300,000 existing inland vessels are at the critical point of aging and renewal. The problems of inconvenient operation, high energy consumption and insufficient adaptability of traditional propulsion systems have been difficult to meet the operational needs of complex inland waterway channels and the requirements of green development. As a core power equipment suitable for small and medium-sized inland transport vessels, the 100kW azimuth thruster, with its integrated, efficient and flexible technical advantages, is gradually replacing the traditional shafting propulsion system, becoming the preferred solution for the power upgrading of inland transport vessels and injecting new momentum into the green and intelligent transformation of inland waterway shipping.

I. Core Technical Characteristics of 100kW Azimuth Thruster and Its Adaptability to Inland Transport Vessels

The 100kW class azimuth thruster is a power equipment tailored for small and medium-sized inland transport vessels (such as 200-500 deadweight tonnage cargo ships, short-distance barges, and inland passenger-cargo ships). Its core design is centered on the operating characteristics of inland waterways, such as many shoals, dense bends, stable navigation speed and frequent berthing, which is highly consistent with the operational needs of inland transport vessels and has prominent core technical characteristics.

First, the integrated design simplifies the ship structure. The thruster adopts an integrated design of motor and pod, integrating the permanent magnet synchronous motor, propeller and steering mechanism into a whole. It does not require complex components such as clutches, gearboxes and long shafting of traditional propulsion systems, which can greatly save the installation space of the ship's engine room and reduce the difficulty of ship design and construction. For small and medium-sized inland transport vessels with limited engine room space, this compact design can not only optimize the internal layout of the ship, but also reduce the ship's own weight and increase the cargo capacity, which is in line with the "light asset, high efficiency" operational needs of inland transport vessels. At the same time, the integrated design reduces the transmission links, lowers the incidence of equipment failures, makes subsequent maintenance more convenient, and effectively reduces the operation and maintenance costs of shipowners.

Second, the full azimuth control is suitable for complex waterways. The 100kW azimuth thruster can achieve 360-degree dead-angle-free rotation, and accurately adjust the direction of propeller thrust through the electronic control system. It can complete ship steering, in-situ U-turn, lateral movement and other actions without relying on rudders, and the control response speed is an order of magnitude higher than that of traditional propulsion systems. Inland waterways generally have the problems of many bends, many narrow sections and dense shoals, especially in areas such as the Yangtze River tributaries and the Beijing-Hangzhou Canal. Ships need to frequently adjust their course and berth accurately. The flexible control performance of the thruster can greatly improve the safety of ship navigation, avoid accidents such as grounding and collision, and at the same time reduce the operation intensity of crew and lower labor costs.

Third, high efficiency and energy saving meet the requirements of green development. The thruster adopts gearless direct drive technology, and the motor output shaft is directly connected to the propeller, which completely eliminates the 8%-12% energy loss caused by the gearbox, and the comprehensive system efficiency can reach more than 90%; at the same time, the shape design of the pod and propeller is optimized through computational fluid dynamics simulation to reduce the interference of ship hull water flow, so that the propeller works in a uniform flow field, further improving the propulsion efficiency. Compared with the traditional shafting propulsion system, it can achieve an energy saving effect of 18%-20%. Combined with the characteristics of stable navigation speed and fixed route of inland transport vessels, the 100kW power segment can accurately match the ship's navigation needs, avoid energy waste caused by power redundancy, and greatly reduce fuel (or electricity) consumption and carbon emissions, which is in line with the national policy requirements for the green and intelligent development of inland vessels.

Fourth, it has outstanding multi-scenario adaptability. In response to the problem of variable water depth in inland waterways, some 100kW azimuth thrusters adopt a liftable design, which can flexibly adjust the lowering depth of the propeller according to different water conditions such as shoals and deep water, avoid propeller cavitation in shallow water areas, not only protect the equipment from damage, but also maintain the best propulsion efficiency at all times. In addition, this power segment thruster can adapt to various power forms such as pure electric and gas-electric hybrid, and perfectly match new operation modes such as "ship-electricity separation" and "charging and swapping standardization", which can meet the operational needs of different shipowners and cover various scenarios such as inland short-distance freight, passenger-cargo transportation and port auxiliary transportation.

II. Application Practice of 100kW Azimuth Thruster on Inland Transport Vessels

With the acceleration of the green and intelligent transformation of inland vessels, the 100kW azimuth thruster has been widely applied on transport vessels in key inland waterways such as the main line of the Yangtze River, the main line of the Xijiang River and the Beijing-Hangzhou Canal. Combined with the operational needs of different ship types, a number of replicable and promotable application cases have been formed, and its application value has been fully verified.

In the field of short-distance inland cargo ships, a shipping company upgraded the power of 3 of its 300 deadweight tonnage inland cargo ships to 100kW azimuth thrusters (pure electric power form), with the operation route being a short-distance freight route in a section of the Beijing-Hangzhou Canal (50 kilometers one way, passing through many bends and shoals). After the upgrade, the maneuverability of the ships was significantly improved, the in-situ U-turn time was shortened from 10 minutes of the traditional propulsion system to 2 minutes, and the berthing efficiency was increased by 40%, effectively reducing voyage delays; at the same time, the energy consumption cost was greatly reduced. Under the pure electric operation mode, the comprehensive operation cost was only 1/3 of that of traditional fuel-powered ships, and the payback period for shipowners was shortened to about 4 years. In addition, the low-noise and low-vibration characteristics of the thruster improved the working environment of the crew, reduced the noise pollution of ship navigation to the surrounding waters, and was highly recognized by the local maritime department and crew.

In the field of inland passenger-cargo transport ships, 2 passenger-cargo ships (carrying 50 passengers and 100 tons of cargo) put into operation by a riverside city adopted 100kW azimuth thrusters (gas-electric hybrid power form), mainly used for the transportation of personnel and small goods between riverside towns. The flexible control performance of the thruster enables it to shuttle accurately in the narrow riverside waterways. Even in seasons with large water level changes, it can adapt to different water depths through the liftable function to ensure navigation safety; the gas-electric hybrid power form combined with the high efficiency and energy saving characteristics of the thruster reduces carbon emissions by more than 60% and noise by 30 decibels compared with traditional fuel-powered ships, which not only meets the comfort needs of personnel transportation, but also achieves green and efficient cargo transportation, becoming a demonstration ship type for green shipping along the river.

In the field of port auxiliary inland transport ships, 10 small transport barges supporting an inland port (used for cargo transshipment in the port) are all equipped with 100kW azimuth thrusters. Due to the narrow waterways and high ship density in the port, the requirements for ship control accuracy are very high. The 360-degree full azimuth function of the thruster enables the barges to achieve lateral berthing and precise positioning, greatly improving the efficiency of port cargo transshipment and reducing ship congestion in the port; at the same time, its integrated design facilitates daily equipment maintenance, reduces port operation and maintenance costs, and provides strong support for green and intelligent port operation.

Application practice shows that the 100kW azimuth thruster can not only solve many pain points of traditional propulsion systems in the application of inland transport vessels, but also resonate with the green, intelligent development trend of inland waterway shipping. It plays an important role in improving ship operation efficiency, reducing operation costs and ensuring navigation safety, and has broad application prospects.

III. Optimization Directions and Matters Needing Attention in the Application Process

Although the application of 100kW azimuth thruster on inland transport vessels has achieved remarkable results, combined with the special operating conditions of inland waterway shipping, targeted optimization is still needed in the actual application process to avoid potential problems and ensure its long-term stable operation.

First, optimize equipment protection to adapt to inland water quality. The water quality of inland waterways is complex, and some waters have the problems of high sediment content and many floating objects, which are likely to cause wear and blockage of the thruster propeller, affecting propulsion efficiency and equipment life. Therefore, in the application process, it is necessary to optimize the pod sealing structure and propeller material, adopt corrosion-resistant and wear-resistant alloy materials, and equip with efficient anti-winding devices. Regularly clean and maintain the propeller to avoid damage to the equipment caused by sediment and floating objects.

Second, improve the construction of supporting infrastructure. For pure electric or hybrid inland transport vessels, the stable operation of the 100kW azimuth thruster relies on a sound charging and swapping infrastructure. At present, the layout of charging and swapping stations in some inland waterways is insufficient, leading to "difficulty in energy supplement" for ships, which limits the promotion and application of thrusters. Therefore, it is necessary to accelerate the layout of charging and swapping infrastructure in combination with inland waterway shipping routes, promote "containerized battery swapping" technology to achieve 15-20 minutes of rapid energy supplement, and improve the charging and swapping standard system to enhance the convenience of energy supplement.

Third, improve the crew's operation and maintenance skills. The operation and maintenance of the azimuth thruster are quite different from those of the traditional propulsion system, requiring the crew to master skills such as electronic control system operation, daily equipment inspection and common fault handling. Some crew members of old ships are not proficient in the operation of new equipment, which is likely to lead to equipment failures or operation errors. Therefore, it is necessary to strengthen crew skill training, carry out targeted operation and maintenance training, improve the crew's ability to control the equipment, and ensure the standardized operation of the equipment.

Fourth, optimize cost control and domestic substitution. At present, some core components of the 100kW azimuth thruster still rely on imports, resulting in high equipment procurement costs, which to a certain extent affects the shipowners' willingness to upgrade. Therefore, it is necessary to increase the research and development of domestic core technologies, promote the domestic substitution of core components such as motors, electronic controls and propellers, and reduce equipment procurement costs; at the same time, optimize the equipment design and production process, improve equipment reliability, reduce subsequent maintenance costs, and further improve the cost performance of the thruster.

IV. Application Prospects and Development Outlook

With the in-depth advancement of national policies such as the "Implementation Opinions on Accelerating the Green and Intelligent Development of Inland Vessels", the green, intelligent and standardized development of inland vessels has become an inevitable trend. The renewal and replacement of 300,000 existing vessels and the mass construction of new energy vessels provide a broad application market for the 100kW azimuth thruster. In the future, the application of this thruster will show three major development trends.

First, intelligent integration and upgrading. Combined with the needs of inland intelligent shipping development, the 100kW azimuth thruster will be deeply integrated with the ship's intelligent navigation system and cloud energy consumption management system, realizing functions such as real-time monitoring of thruster operation status, intelligent energy consumption optimization and fault early warning. Combined with radar, visual recognition and other technologies, it will help ships achieve automatic collision avoidance and remote control, further improve the intelligence level of ship operation, reduce crew allocation and lower labor costs.

Second, the coordinated development of multiple power forms. With the continuous maturity of battery technology and hydrogen fuel technology, the 100kW azimuth thruster will further adapt to various green power forms such as pure electric, hydrogen fuel and methanol power. Combined with new operation modes such as "ship-electricity separation", it will further reduce the initial cost of shipowners, promote inland transport vessels to achieve "zero emission" operation, and meet the requirements of the "dual carbon" goals.

Third, the continuous improvement of domesticization level. Under the wave of domestic substitution, domestic enterprises will further deepen the core technology of the 100kW class azimuth thruster, break through the key technical bottlenecks of motors and electronic controls, realize the full domesticization of core components, and at the same time optimize product design, improve equipment adaptability and reliability, create domestic products with international competitiveness, and promote the independent controllability of inland ship power equipment.

Conclusion: Centered on the operating needs of inland transport vessels, the 100kW azimuth thruster, with its integrated, flexible, efficient and green technical advantages, effectively solves many pain points of traditional propulsion systems. It plays an irreplaceable role in improving ship operation efficiency, reducing operation costs, ensuring navigation safety and promoting green development. With the continuous acceleration of the green and intelligent transformation of inland waterway shipping, as well as the continuous optimization of core technologies and the advancement of domestic substitution, the 100kW azimuth thruster will be widely applied on more inland transport ship types, inject stronger momentum into the high-quality development of China's inland waterway shipping, and help build a green, intelligent and efficient inland water economic pattern.