Waste Heat Recovery System with Multi-Pressure Circuit Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Waste heat recovery systems (WHR) face inefficiencies due to deviations in operating temperature and pressure of working fluids in multiple circuits, leading to suboptimal heat recovery and engine performance.
Innovation Solution
A WHR system with multiple pressure circuits and a controller that monitors temperature and pressure values to control flow rates and bypass valves, maintaining working fluids within desired ranges by adjusting pump flow and bypassing fluids through heat exchangers and expanders.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the working fluid flow rate is increased to improve heat recovery efficiency, then the heat recovery efficiency is improved, but the temperature and pressure deviations in multiple circuits worsen leading to suboptimal operation
Solution Approach 1:
The patent implements dynamic control of bypass valves and pumps in multiple pressure circuits to adaptively regulate working fluid flow rates. The controller adjusts the degree of bypassing in real-time based on temperature and pressure sensor feedback, enabling the system to maintain optimal operating conditions while maximizing heat recovery efficiency across varying engine loads and environmental conditions.
Solution Approach 2:
The patent employs feedback control mechanisms where temperature and pressure sensors monitor the working fluid conditions in each pressure circuit, and the controller uses this information to adjust bypass valve positions and pump operations. This closed-loop feedback system ensures that temperature and pressure deviations are corrected, maintaining reliable operation while optimizing heat recovery performance.
2Reliability
If bypass valves are used to control working fluid flow to maintain optimal temperature and pressure, then the operating condition stability is improved, but the device complexity increases due to multiple pressure circuits and control components
Solution Approach 1:
The patent divides the waste heat recovery system into multiple independent pressure circuits (e.g., high-pressure and low-pressure circuits), each with its own bypass valve and control logic. This segmentation allows each circuit to be optimized and controlled independently, improving overall system reliability while managing complexity through modular design that can be implemented in stages.
Solution Approach 2:
The controller serves multiple functions by managing both bypass valves and pumps across different pressure circuits using a single control unit. The system architecture allows components to serve multiple purposes - for example, the bypass valves not only regulate flow but also provide pressure relief and temperature control, reducing the need for separate dedicated components and thereby managing complexity.
3Productivity
If multiple pressure circuits are implemented to improve heat recovery efficiency, then the heat recovery efficiency is improved, but the device complexity increases
Solution Approach 1:
The patent implements multiple pressure circuits (high-pressure and low-pressure circuits) that operate in parallel to capture waste heat from different temperature ranges simultaneously. This segmentation of the thermal recovery process into distinct pressure levels enables the system to improve overall heat recovery efficiency by utilizing a broader temperature spectrum, while the modular circuit design facilitates manageable complexity.
Solution Approach 2:
The patent employs a nested circuit architecture where low-pressure and high-pressure circuits are interconnected through shared components such as the expander, condenser, and evaporator. The circuits are nested in the sense that they share common thermal exchange points and can be integrated into a unified control framework, allowing complex multi-pressure operation while reducing the total number of independent components needed.
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 efficiency of heat recovery and engine performance by maintaining optimal temperature and pressure conditions, increasing power output and reducing the risk of condensation and cavitation.
Implementation Method 1
a first heat exchanger configured to cool the working fluid received from the second pressure circuit using engine coolant
Implementation Method 2
a first expander configured to receive the working fluid from the first heat exchanger and expand the working fluid
Implementation Method 3
a first pump configured to receive the working fluid from the condenser and compress the working fluid
Implementation Method 4
a condenser configured to receive the working fluid from the first expander and condense the working fluid
Data Source
AI summary
A waste heat recovery (WHR) system that can be utilized in internal combustion engine systems includes at least two circuits, one having a low pressure working fluid and another having a high pressure working fluid. Each circuit can include heat exchangers to allow the working fluid to absorb heat form one or more heat source fluids associated with the engine. The system can also include an expander configured to receive the working fluid from the at least two circuits, and generating mechanical power. The system also can include a condenser, a sub cooler, and at least one working fluid pump to pump the working fluid in the at least two circuits. The cooling system also includes a controller that can receive temperature and pressure values from various locations in the WHR system and control at least the flow rates of the working fluids in the at least two circuits.