Dual-Cycle Power Generation System Using Cascaded Thermal Energy
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Solution Overview
Problem
Existing power generation systems using natural thermal energy struggle to effectively reuse thermal energy without additional artificial heating sources, especially when utilizing thermal energy from natural sources like seawater or geothermal heat.
Innovation Solution
A power generation system utilizing two thermal cycles and three working media, where thermal energy is efficiently transmitted and converted into kinetic energy using external-combustion engines, and eventually into electrical energy, without requiring combustion, by leveraging the properties of each working medium.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If thermal energy from natural sources is used directly in a single thermal cycle, then power generation can be achieved, but thermal energy cannot be effectively reused and energy efficiency is limited
Solution Approach 1:
The single thermal cycle is divided into two separate thermal cycles (first thermal cycle with first working medium, second thermal cycle with second working medium). Each cycle operates independently with its own heat exchanger, thermal engine, and power generator, allowing thermal energy to be utilized at different temperature levels and preventing energy loss
Solution Approach 2:
Different working media are selected with different physical and chemical properties (boiling points, heat capacities, molecular weights) to optimize thermal energy conversion at various temperature ranges. The first working medium has lower boiling point for low-temperature thermal energy, while the second working medium has higher boiling point for high-temperature thermal energy
2Loss of energy
If a cold source medium is used to reuse thermal energy from the working medium, then thermal energy can be transmitted, but additional artificial heating is required which reduces effectiveness
Solution Approach 1:
The system uses itself to reuse thermal energy. The first working medium after expansion in the first thermal engine is directed to the second heat exchanger to serve as the cold source medium for the second thermal cycle, enabling self-contained thermal energy reuse without external artificial heating
Solution Approach 2:
The two thermal cycles are merged into a unified system where the output of the first cycle (used working medium) becomes the input for the second cycle (cold source). This integration allows thermal energy to be cascaded from the first cycle to the second cycle, maximizing energy utilization
3Productivity
If two thermal cycles are used to transmit thermal energy between working media, then power generation can be performed by the cold source medium, but the system complexity increases
Solution Approach 1:
Both the first and second thermal cycles serve dual functions: they independently generate power through their respective thermal engines and power generators, while simultaneously enabling thermal energy transmission from the first cycle to the second cycle. This multi-functionality increases productivity without proportionally increasing complexity
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 allows for the effective conversion of low-level thermal energy from natural sources into electrical energy with minimal environmental impact and cost, reducing thermal energy loss and enhancing energy efficiency.
Implementation Method 1
a first heat exchanger for performing thermal exchange between the first working medium and a thermal source medium
Implementation Method 2
a first thermal engine configured to take out kinetic energy from the first working medium heated by the first heat exchanger
Implementation Method 3
a first power generator configured to convert the kinetic energy taken out by the first thermal engine, into electrical energy
Implementation Method 4
a second heat exchanger for performing thermal exchange between the second working medium and a thermal source medium
Implementation Method 5
a mixing means configured to mix the second working medium and the third working medium
Implementation Method 6
a second thermal engine configured to take out kinetic energy from mixed fluid of the second working medium and the third working medium
Implementation Method 7
a second power generator configured to convert the kinetic energy taken out by the second thermal engine, into electrical energy
Implementation Method 8
a third heat exchanger for performing thermal exchange between the first working medium discharged from the first thermal engine, and mixed fluid of the second working medium and the third working medium that is discharged from the second thermal engine
Data Source
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AI summary
To provide a power generation system and a power generation method that can use thermal energy in a natural world as a thermal source, and can perform power generation while suppressing loss of thermal energy as far as possible. A first heat exchanger 1A, a first thermal engine 2A, and a first power generator 3A are included on a first working medium line L1 that circulates a first working medium W1, a second heat exchanger 1B, a third working medium supply means 5 that supplies a third working medium W3, a mixing means 6 that mixes a second working medium W2 and the third working medium W3, a second thermal engine 2B, and a second power generator 3B are included on a second working medium line L2 that circulates the second working medium W2, and on both of a downstream side of the first thermal engine 2A on the first working medium line L1 and a downstream side of the second thermal engine 2B on the second working medium line L2, a third heat exchanger 1C is included, and a third working medium discharge means 10 for discharging the third working medium W3 to the third heat exchanger 1C is included.