Floating OTEC Plant With Multi-Stage Heat Exchange and Stable Cold Water Pipe
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Ocean Thermal Energy Conversion (OTEC) power plants face low overall efficiency, high construction and operating costs, and environmental concerns due to low thermodynamic efficiency, large parasitic loads, and challenges in designing and maintaining long cold water intake pipes in dynamic ocean environments.
Innovation Solution
A floating OTEC power plant with a multi-stage heat engine and integrated heat exchange compartments, featuring a continuous offset staved cold water pipe and a hybrid cascading multi-stage heat exchange system, which reduces parasitic loads, construction costs, and environmental impact by minimizing wave-induced movement and optimizing water flow through the heat exchangers.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If traditional single-stage heat exchange systems are used in OTEC power plants, then the system design is simple, but the heat transfer efficiency is low and parasitic loads are high
Solution Approach 1:
The heat exchange system is divided into multiple stages (typically 3-5 stages) with each stage having its own heat exchanger and working fluid circuit. This segmentation allows progressive heating of the working fluid, improving overall heat transfer efficiency while maintaining manageable system complexity through modular design
Solution Approach 2:
The patent introduces a vertical dimension to the heat exchange process by stacking heat exchanger stages at different elevations, utilizing the natural temperature gradient of ocean water from surface to depth. This multi-level arrangement optimizes heat transfer efficiency without significantly increasing horizontal footprint
2Reliability
If long cold water intake pipes are used to reach deep ocean water, then cold water supply is ensured, but construction and operating costs increase and maintenance becomes difficult
Solution Approach 1:
The cold water intake pipe is integrated within the hollow structural column of the floating platform, nesting the pipe system inside the existing structural element. This eliminates the need for separate external piping, reducing construction complexity and maintenance requirements while ensuring reliable cold water supply from deep ocean layers
Solution Approach 2:
The structural column serves dual functions: providing the floating platform's structural support and housing the cold water intake pipe. This multi-functionality reduces the number of separate components needed, simplifying the overall system while maintaining reliable cold water supply
3Stability of the object's composition
If the floating platform is designed with large surface area for stability, then wave-induced movement is reduced, but construction costs and environmental footprint increase
Solution Approach 1:
The floating platform utilizes a hollow columnar structure that leverages buoyancy and hydrodynamic principles to achieve stability without requiring excessive surface area. The column's geometry and hollow construction provide inherent stability while minimizing material usage and environmental footprint
Solution Approach 2:
The hollow columnar structure utilizes buoyant force as a counterweight to stabilize the platform against wave-induced movements. The displaced water provides an upward buoyant force that counteracts gravitational forces and stabilizes the structure without requiring additional stabilizing components
4Productivity
If high temperature difference is utilized for power generation, then thermodynamic efficiency improves, but environmental impact increases due to thermal discharge
Solution Approach 1:
The heat exchange process is segmented into multiple stages, each extracting heat at progressively lower temperature differences. This staged approach maximizes power generation efficiency while distributing thermal discharge across multiple temperature levels, reducing the environmental impact of any single discharge point
Solution Approach 2:
The system recovers thermal energy at multiple stages rather than discarding it as waste heat. Each heat exchange stage captures available thermal energy, and the final discharge temperature is minimized by the cumulative heat extraction process, reducing environmental impact while maintaining high efficiency
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 solution enhances overall efficiency, reduces construction and operating costs, and minimizes environmental footprint by improving heat transfer efficiency and reducing pressure losses, while allowing for efficient and stable operation in dynamic ocean conditions.
Implementation Method 1
a first multi-stage heat exchange system for heating a second working fluid to a vapor using a first warm water conduit in communication with a first turbine
Implementation Method 2
The OTEC process uses the temperature difference between surface and deep sea tropical waters to drive a heat engine to produce electrical energy
Implementation Method 3
a second multi-stage condensing system for condensing the working fluid from a vapor to a liquid using a second cold water conduit
Implementation Method 4
Ocean Thermal Energy Conversion (OTEC) power plants face low overall efficiency, high construction and operating costs, and environmental concerns due to low thermodynamic efficiency
Implementation Method 5
the maximum ideal Carnot efficiency of an OTEC power plant will be 7.5 to 8%
Data Source
AI summary
An offshore power generation structure comprising a submerged portion having a first deck portion comprising an integral multi-stage evaporator system, a second deck portion comprising an integral multi-stage condensing system, a third deck portion housing power generation equipment, cold water pipe; and a cold water pipe connection.