Multi-Component Working Fluid Power Cycle for Lower Heat Rejection
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Solution Overview
Problem
Conventional combustion systems face inefficiencies due to excess air usage, leading to reduced heat availability for energy conversion and increased heat rejection, and require complex and expensive structures for internal cooling, while fluidized bed combustors suffer from high air flow rates and reduced efficiencies.
Innovation Solution
A system and process that extracts energy from a multi-component working fluid by forming different compositional streams, including a rich and lean working fluid stream, and utilizes a heat recovery vapor generator to vaporize and condense these streams efficiently, generating power through multiple turbines and heat exchange units.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If excess air is used in combustion systems to ensure complete fuel combustion, then combustion completeness is improved, but heat availability for energy conversion is reduced and heat rejection increases
Solution Approach 1:
The invention extracts the cooling function from the combustion chamber structure by removing waterwall tubes, and instead extracts heat from the flue gases through a separate heat recovery steam generator. This separation allows the combustion chamber to operate with minimal excess air for complete combustion, while the heat recovery system captures the thermal energy that would otherwise be rejected.
Solution Approach 2:
The invention introduces a heat recovery steam generator as an intermediary device between the combustion chamber and the working fluid. This mediator captures heat from the flue gases without requiring the combustion chamber itself to be cooled by waterwalls, thus resolving the conflict between combustion completeness and heat rejection.
2Temperature
If waterwall tubes are used for internal cooling in combustion zones, then temperature control is improved, but system complexity and maintenance requirements increase
Solution Approach 1:
The invention extracts the cooling function from the combustion chamber structure by removing waterwall tubes. The combustion chamber is designed without internal cooling structures, and the temperature control function is transferred to the heat recovery steam generator system where heat is extracted from flue gases in a controlled manner.
Solution Approach 2:
The heat recovery steam generator acts as an intermediary that performs the heat extraction function without requiring direct contact between cooling surfaces and the combustion zone. This separates the temperature control function from the combustion chamber structure, eliminating the need for complex waterwall tube systems.
3Device complexity
If separate combustion chamber without internal cooling is used, then system simplicity and cost are improved, but flue gas temperature becomes unacceptably high for direct heat exchanger use
Solution Approach 1:
The invention segments the heat recovery process into multiple stages within the heat recovery steam generator. The flue gases first preheat the feedwater, then further heat the water to generate steam, and finally superheat the steam. This segmentation allows the system to handle high temperature flue gases from a simple combustion chamber while producing usable thermal energy at appropriate temperatures for power generation.
Solution Approach 2:
The invention changes the parameters of the working fluid (water/steam) through staged heating processes. The feedwater enters the heat recovery steam generator at a low temperature and is progressively heated through different heat exchange zones, transforming it into high-energy steam suitable for turbine operation while the flue gases are cooled in stages.
4Productivity
If multi-component working fluid with different compositional streams is used, then overall energy conversion efficiency is improved, but system complexity increases
Solution Approach 1:
The invention segments the working fluid into multiple compositional streams (rich stream with high ammonia content, lean stream with low ammonia content, and intermediate stream) that are processed through different portions of the heat recovery steam generator. This segmentation allows each stream to be optimized for specific temperature ranges and heat extraction levels, maximizing overall energy conversion efficiency.
Solution Approach 2:
The invention applies local quality by using different working fluid compositions in different locations of the heat recovery steam generator. The rich working fluid stream is used in zones where high temperature heat extraction is needed, the intermediate stream in middle temperature zones, and the lean stream in lower temperature zones, optimizing heat transfer efficiency in each local region.
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 enhances the overall efficiency of energy conversion by minimizing excess air usage, reducing heat rejection, and eliminating the need for internal cooling structures, resulting in a more reliable and cost-effective power generation system.
Implementation Method 1
vaporized in a heat recovery vapor generator
Implementation Method 2
pressurized into its super-critical state before being vaporized
Implementation Method 3
converting thermal energy into electrical power or other useable energy
Implementation Method 4
heat exchange units
Implementation Method 5
vaporized and condense these streams efficiently
Data Source
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AI summary
A system and method are disclosed for converting thermal energy into power from three different compositional streams of a multi-component working fluid, one of the streams being a lean working fluid stream pressurized into its super-critical state before being vaporized in a heat recovery vapor generator, another stream is a rich working fluid steam and the third stream is an intermediate working fluid stream, where the system and process has increased overall efficiency.