Ship Propulsion Energy Storage and Phase Compensation
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Solution Overview
Problem
Ship propulsion engines face reduced fuel efficiency due to fluctuating power needs at constant rotation speeds, leading to suboptimal engine operation and increased fuel consumption when the power or speed deviates from the optimal combination.
Innovation Solution
The implementation of a propulsion system that utilizes energy storage to balance electrical power fluctuations and operates one generator as a phase compensator, or adjusts the engine's rotational speed via mechanical or electrical transmission to maintain constant generator speed, optimizing fuel efficiency by storing excess energy for later use and adjusting engine load accordingly.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the engine operates at constant rotation speed to meet fluctuating power needs, then the power supply remains stable, but fuel efficiency deteriorates when power demand deviates from optimal power/rpm combination
Solution Approach 1:
The patent applies dynamics by allowing the engine speed to vary dynamically rather than maintaining constant speed. The engine speed is adjusted according to the actual power demand to keep the engine operating at optimal fuel efficiency points. This resolves the contradiction by making the system adaptive: power supply stability is maintained through control strategies while fuel efficiency is improved through variable speed operation.
Solution Approach 2:
The patent changes the operating parameters of the engine by adjusting rotation speed based on power demand. Instead of fixed speed operation, the engine operates at variable speeds that optimize fuel consumption. This parameter change allows the system to maintain reliability through proper control while improving fuel efficiency by avoiding suboptimal operating conditions.
2Use of energy by moving object
If the engine speed is adjusted to optimize fuel efficiency, then fuel consumption improves, but generator output frequency becomes unstable
Solution Approach 1:
The patent introduces an intermediary element (such as a flywheel or energy storage system) between the engine and generator. This intermediary absorbs speed variations from the engine while maintaining constant speed at the generator, thereby decoupling the engine speed adjustments from generator frequency. This allows fuel efficiency optimization through variable engine speed without compromising generator output stability.
Solution Approach 2:
The patent segments the power transmission system into distinct functional parts: the engine section that operates at variable speeds for fuel efficiency, and the generator section that maintains constant speed for frequency stability. This segmentation allows each component to operate independently in its optimal regime, resolving the contradiction between fuel efficiency and frequency stability.
3Reliability
If multiple generators are used to handle power fluctuations, then power supply reliability improves, but system complexity increases
Solution Approach 1:
The patent makes one of the generators multi-functional by enabling it to operate in dual modes: as a power-generating unit during normal operation and as a motor-driven load during peak demand periods. This universal generator can switch roles based on system needs, providing power supply reliability without requiring additional generators. The reduced number of generators lowers system complexity while maintaining reliability through flexible operational modes.
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
This approach stabilizes engine load, reduces fuel consumption, and maintains high efficiency by ensuring optimal fuel usage in relation to electricity production, even under varying power demands, thereby improving overall engine performance.
Implementation Method 1
storing excess energy in an energy storage and releasing it from there when the energy consumption is higher than optimal electricity production capacity of the genset
Implementation Method 2
The second embodiment of the invention includes the use of a mechanical or electrical transmission between the engine and generator or propulsion shaft
Data Source
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AI summary
A propulsion system for a vessel is provided, which comprises at least two generator sets, each including an prime mover and a generator, an electric propulsion unit, an energy storage, and a main switchboard by which the at least two generator sets, the electric propulsion unit and the energy storage are connected to each other. Excess electrical power is stored in the energy storage when the generator produces electric power in excess for the instantaneous needs of the vessel, and needed additional energy is taken from the energy storage for the use of the ship electricity network when the electric generator produces electric power instantaneously insufficiently, and the generator of one of the two generator sets is operated as a phase compensator for supplying reactive power to the propulsion system.