Variable-Speed Thermal Fluid Pump Control for Brayton Cycle Efficiency
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Solution Overview
Problem
Current closed thermodynamic cycle power generation systems, such as Brayton cycles, face challenges in efficiently managing thermal energy storage and conversion due to fluctuations in operating conditions, leading to suboptimal performance and efficiency.
Innovation Solution
Implementing a controlled variable speed pump system that adjusts the flow rate of thermal fluids based on real-time operational parameters, using sensors to monitor temperature differences and control the pump speed to maintain a constant approach temperature in heat exchangers, thereby optimizing energy transfer and efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a fixed speed pump is used to circulate thermal fluid through heat exchangers, then the system structure is simple, but the system cannot adapt to fluctuations in operating conditions, leading to suboptimal efficiency
Solution Approach 1:
The patent applies dynamics by transitioning from a fixed-speed pump to a variable-speed pump that can dynamically adjust its operation. The pump speed is varied in response to changing operating conditions (such as temperature differences, flow rates, or power output requirements), allowing the heat exchanger system to maintain optimal thermal energy transfer efficiency across different operating scenarios.
Solution Approach 2:
The patent implements feedback control by monitoring system operating parameters (such as temperature differences across heat exchangers, thermal fluid flow rates, or power output) and using this information to automatically adjust the pump speed. This closed-loop control ensures the system adapts to fluctuations while maintaining efficiency, resolving the contradiction between adaptability and complexity.
2Loss of energy
If thermal energy storage and conversion is managed with fixed operating parameters, then the system operation is simple, but the roundtrip efficiency is reduced due to inability to optimize energy transfer
Solution Approach 1:
The patent uses feedback control to monitor thermal energy storage and conversion parameters (such as temperature differences, heat transfer rates, and energy density) and automatically adjusts pump speed to optimize roundtrip efficiency. This minimizes energy losses during charging and discharging cycles by ensuring optimal thermal energy transfer conditions are maintained throughout the storage process.
Solution Approach 2:
The patent applies parameter changes by dynamically varying the pump speed parameter in response to changing thermal energy storage conditions. By adjusting the thermal fluid flow rate through the heat exchangers, the system optimizes heat transfer efficiency during different phases of energy storage and conversion, thereby reducing overall energy losses and improving roundtrip efficiency.
3Object-generated harmful factors
If the pump operates at constant speed, then the mechanical system is simpler and more reliable, but entropy generation increases due to non-optimal heat transfer conditions
Solution Approach 1:
The patent applies dynamics by using a variable-speed pump that can adapt its operation to match the actual thermal energy transfer requirements. By dynamically adjusting the pump speed, the system maintains optimal heat transfer conditions across different operating scenarios, minimizing temperature differences and reducing entropy generation that would occur with fixed-speed operation.
Solution Approach 2:
The patent implements feedback control to monitor heat transfer conditions (such as temperature differences across heat exchangers) and adjust pump speed accordingly. This ensures that thermal energy transfer occurs under near-optimal conditions, minimizing irreversibilities and entropy generation while the automatic control manages the added system complexity.
4Productivity
If thermal fluid flow rate is not dynamically adjusted, then the system has lower operational complexity, but power output and storage capacity are suboptimal
Solution Approach 1:
The patent applies dynamics by using a variable-speed pump that can adjust the thermal fluid flow rate in real-time based on system demands. This dynamic adjustment allows the system to maximize power output during generation modes and optimize storage capacity during charging modes, adapting to varying operational requirements while maintaining manageable complexity through proven control strategies.
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 system's ability to maintain efficiency and stability by dynamically adjusting to fluctuations, improving the roundtrip efficiency and reducing entropy generation, ultimately leading to higher power output and storage capacity.
Implementation Method 1
a heat exchanger is used to transfer that energy to steam or other working fluid
Implementation Method 2
a first pump configured to pump a first thermal fluid at a variable flow rate based on pump speed through the first heat exchanger and in thermal contact with the working fluid
Implementation Method 3
a first pump configured to pump a first thermal fluid at a variable flow rate based on pump speed
Implementation Method 4
a turbine...a generator driven by the turbine and configured to generate a quantity of electrical power
Data Source
AI summary
Disclosed are systems and methods for pump control of a closed thermodynamic cycle system, such as a Brayton cycle. Operational parameters such as working fluid temperature, thermal fluid temperature, stream pressure, and power generation may be the basis for controlling a thermal fluid pump rate.