Ship Propulsion Control Unit Optimizing Power for Cavitation Prevention
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Solution Overview
Problem
Inland ships with diesel engines operate inefficiently in varying modes, leading to excessive power supply to propellers, causing cavitation and potential damage, as well as inability to react to grounding incidents effectively.
Innovation Solution
A propulsion system with electric drives and a control unit that adjusts power supply to the propeller based on its characteristic curve, optimizing power conversion and preventing cavitation, while also enabling early detection of grounding for controlled emergency stops.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the diesel engine operates at constant maximum power setting to ensure maneuverability under unfavorable conditions, then the ship can be maneuvered even under the most unfavorable conditions, but the drive unit is operated in an energetically unfavourable partial mode in most modes resulting in excessive power input
Solution Approach 1:
The patent applies dynamics by transitioning from a static constant power setting to a dynamic power adjustment system. The control unit continuously monitors propeller parameters (torque, speed, power) and dynamically adjusts the diesel engine's power output to match the actual propeller requirements, enabling the system to adapt to varying operating conditions while maintaining maneuverability and improving energy efficiency.
Solution Approach 2:
The patent implements feedback control by using sensors to monitor propeller operating parameters (torque M, speed n, power P) and feeding this information back to the control unit. The control unit processes this feedback data and adjusts the diesel engine's power setting accordingly, creating a closed-loop control system that optimizes energy efficiency while ensuring the ship can respond to maneuvering demands.
2Force
If excessive power input is supplied to the propeller to ensure sufficient thrust, then the propeller can provide adequate thrust for maneuvering, but cavitation occurs at the propeller reducing efficiency and causing damage to propeller blades
Solution Approach 1:
The patent applies parameter changes by continuously monitoring and adjusting the propeller's operating parameters (torque, speed, power) and using this information to optimize the power input. The control unit modifies the diesel engine's output parameters to match the propeller's actual needs, preventing excessive power input that would cause cavitation while ensuring sufficient thrust is delivered for effective maneuvering.
3Speed
If the propeller speed is increased to improve ship speed, then the ship can travel faster, but the power required increases and may exceed the propeller's optimal operating range causing cavitation
Solution Approach 1:
The patent applies dynamics by enabling continuous adjustment of propeller speed and power settings based on real-time operating conditions. The control unit dynamically optimizes the balance between ship speed requirements and power consumption, adjusting the diesel engine output and propeller operation to maintain efficient performance across varying speed demands while preventing cavitation.
Solution Approach 2:
The patent applies parameter changes by using sensors to monitor propeller speed, torque, and power, and using this feedback to adjust operating parameters optimally. The control unit modifies power delivery parameters based on the propeller's characteristic curve and actual performance, ensuring the ship achieves the required speed while minimizing power consumption and preventing cavitation.
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 achieves economical operation, prevents cavitation-related damage, and reduces the risk of propeller damage during grounding by optimizing power supply and enabling precise control of propeller movement.
Implementation Method 1
An arrangement of electric drives (4) arranged on the drive shaft (3)... an arrangement of generators (9) for supplying energy to the electric drives (4)
Implementation Method 2
Excessive power input can cause cavitation at the propeller. Such cavitation not only reduces the propeller's efficiency, but can also cause serious damage to the propeller
Data Source
Figure 1
Figure 2
AI summary
The system (1) has a drive shaft (3) with a propeller (2), and an electrical drive (4) arranged on the drive shaft. A generator (9) supplies energy to the electrical drive, and a controlling unit controls power depending on characteristics of the propeller. Power is guided to the propeller by the electrical drive, and characteristics of the propeller define maximum rotational speed of the propeller. An inverter module (6) is assigned to the electrical drive, and is controlled by the controlling unit.