Auxiliary Electric Thruster Control Below Troll Thrust
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Solution Overview
Problem
Existing marine vessels struggle with unstable speed and noise/vibration issues when navigating at speeds lower than the troll thrust state, and they also emit significant carbon dioxide emissions.
Innovation Solution
A marine propulsion system with a main propulsion device and an auxiliary propulsion device, where the auxiliary device is driven by an electric motor to stabilize speed and reduce emissions by adjusting thrust without engine-driven vibrations, using an electric drive control to manage thrust below troll thrust levels.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If the engine continuously drives the main thruster to generate minimum thrust (troll thrust), then the marine vessel can maintain a steady speed, but the speed cannot be reduced below this minimum thrust level and carbon dioxide emissions increase
Solution Approach 1:
The propulsion system is segmented into two independent units: the main propulsion device with engine and main thruster, and the auxiliary propulsion device with electric motor and auxiliary thruster. This segmentation allows the system to operate the auxiliary electric thruster independently for low-speed navigation, avoiding the need to run the main engine continuously and thereby reducing carbon dioxide emissions while maintaining navigation capability below troll thrust speeds.
Solution Approach 2:
The patent replaces the mechanical engine-driven main thruster system with an electric motor-driven auxiliary thruster system for low-speed operations. This substitution eliminates the need for combustion engine operation at very low loads, reducing carbon dioxide emissions while providing precise speed control below the traditional troll thrust minimum speed.
2Speed
If the shift-in state and neutral state are alternately repeated to reduce speed below troll thrust, then the marine vessel can navigate at lower speeds, but the speed becomes unstable and noise and vibrations increase
Solution Approach 1:
The auxiliary propulsion device provides continuous thrust through the electric motor driving the auxiliary thruster, eliminating the need to alternate between shift-in and neutral states. This continuous operation ensures stable speed control below troll thrust levels without the speed fluctuations and instability caused by repeated state switching.
3Speed
If the shift-in state and neutral state are alternately repeated to reduce speed below troll thrust, then the marine vessel can navigate at lower speeds, but noise and vibrations are repeatedly generated reducing quietness
Solution Approach 1:
The patent substitutes the mechanical shifting mechanism of the main propulsion device with an electric motor-driven auxiliary propulsion device. The electric motor provides smooth, vibration-free operation without mechanical gear shifting, thereby eliminating the repeated noise and vibrations that occur when alternating between shift-in and neutral states, and improving overall quietness during low-speed navigation.
4Force
If the engine continuously drives the main thruster, then sufficient thrust is generated for navigation, but the minimum output is too high for very low speed navigation and energy consumption increases
Solution Approach 1:
By segmenting the propulsion system into main and auxiliary devices with different minimum outputs, the patent enables the auxiliary electric propulsion device to provide just enough thrust for very low-speed navigation. This avoids the excessive energy consumption that would result from operating the main engine at high minimum output levels for low-speed operations, optimizing energy efficiency across different speed ranges.
Solution Approach 2:
The patent changes the operational parameters by introducing an auxiliary propulsion device with a minimum output specifically designed for low-speed navigation. This parameter change allows the system to operate at lower thrust levels and energy consumption for very low speed navigation, while the main propulsion device retains its higher minimum output capability when needed.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The system stabilizes speed, reduces noise and vibrations, and decreases carbon dioxide emissions by utilizing an electric thruster with a smaller output than the main thruster, ensuring smooth navigation at low thrust levels.
Implementation Method 1
including an electric motor to drive an auxiliary propeller 31
Data Source
AI summary
A marine propulsion system includes a controller configured or programmed to perform an electric drive control to cause an electric motor to drive an auxiliary thruster in an auxiliary propulsion device and having a minimum output smaller than a minimum output of a main thruster without performing an engine drive control to cause an engine to drive the main thruster in a main propulsion device when adjusting a thrust of a marine vessel to less than a troll thrust.