sCO2 Brayton Cycle Recuperator Layout for Better Heat Recovery
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Solution Overview
Problem
Existing supercritical carbon dioxide regenerative Brayton cycles with multiple recuperators and auxiliary compressors suffer from suboptimal heat recovery, leading to inefficiencies in energy conversion from low-, medium-, and high-temperature heat sources.
Innovation Solution
A new cycle configuration is introduced that calculates the optimum number of recuperators and auxiliary compressors to maximize heat recovery by iteratively determining the outlet temperatures and pressures, using a method that includes split factors and pinch values to ensure efficient heat exchange.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If a maximum of two recuperators are used in series to recover heat from the turbine outlet, then the device complexity is reduced, but the heat recovery efficiency is not optimized
Solution Approach 1:
The heat recovery process is segmented into multiple stages by using N recuperators in series, where each recuperator recovers heat from different temperature ranges of the turbine outlet stream. This segmentation allows progressive heat recovery across multiple temperature levels, maximizing overall heat recovery efficiency while managing system complexity through modular architecture.
Solution Approach 2:
The patent introduces an additional dimension to the heat recovery process by adding multiple recuperators in series rather than using a single or dual-stage system. This dimensional expansion in the heat exchange pathway enables comprehensive heat recovery across the entire temperature spectrum from turbine outlet, transforming the conventional two-recuperator limit into an optimized N-recuperator configuration.
2Productivity
If the number of recuperators N is increased to improve heat recovery, then the energy efficiency improves by up to 3.84 points, but the device complexity and number of auxiliary compressors increase
Solution Approach 1:
The system employs dynamic optimization by calculating the optimum number of recuperators N based on specific operating conditions, heat source temperatures, and energy efficiency targets. This dynamic approach allows the system configuration to adapt to different operational scenarios, achieving up to 3.84 efficiency improvement points while managing complexity through condition-based optimization rather than fixed architecture.
Solution Approach 2:
The patent utilizes parameter changes in the thermodynamic cycle by varying the number of recuperators N, turbine inlet pressure, temperature, and compressor isentropic efficiencies to optimize energy efficiency. By systematically adjusting these parameters and calculating their impact on cycle performance, the system achieves superior efficiency while maintaining manageable complexity through parameter optimization.
3Manufacturing precision
If iterative calculations are performed to determine outlet temperatures and pressures for each compressor, then the precision of cycle optimization improves, but the calculation time and computational complexity increase
Solution Approach 1:
The patent applies preliminary action by pre-defining the iterative calculation framework and convergence criteria before performing the actual optimization. The method establishes the sequence of calculations for determining outlet temperatures and pressures, pre-calculates thermophysical properties of CO2, and sets up the iterative loops with predetermined stopping conditions. This preliminary structuring enables precise cycle optimization while minimizing calculation time through efficient computational organization.
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 new configuration significantly improves energy efficiency by up to 3.84 points compared to state-of-the-art cycles, enhancing mechanical or electrical energy generation per operating hour.
Implementation Method 1
sCO2 stream RHI N is cooled in N recuperators... sCO2 stream RHI N is cooled to stream RHO N (Recuperator N Hot Outlet) and heats stream RCI N (Recuperator N Cold Inlet) to RCO N in the recuperator number N
Implementation Method 2
sCO2 stream TI is expanded in a turbine to a pressure between 3 MPa and 10 MPa (stream Recuperator N Hot Inlet (RHI N)), and generates some mechanical or electrical energy
Implementation Method 3
sCO2 stream MCI is compressed in the main compressor to the same or higher pressure than the one defined for the turbine inlet (stream TI)
Data Source
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AI summary
Method for producing energy by means of a supercritical carbon dioxide (sCO2) regenerative Brayton cycle with N recuperators in series and N or N-1 auxiliary compressors, where N ≥ 3. By using a higher number of recuperators in series and an auxiliary compressor for each recuperator, the heat recovery process is improved and thus the performance of the cycle compared to the cycles of the state-of-the-art.