Variable Nozzle Heat Exchanger for Engine Waste Heat
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Solution Overview
Problem
Existing systems for utilizing waste heat from combustion engines face challenges in maintaining optimal temperature conditions to prevent corrosion and ensure efficient energy generation, particularly in varying operating conditions, leading to inefficiencies and increased costs due to redundant components.
Innovation Solution
A device with a variable heat exchanger system that controls the mass flow of the heat transfer medium through multiple heat exchangers, allowing for efficient use of waste heat while preventing excessive cooling, and includes a bypass line and valves to adjust the mass current, enabling adaptation to changing conditions and reducing the need for redundant components.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If the heat exchanger is designed for maximum cooling in nominal operation, then waste heat utilization is improved, but the minimum temperature in the exhaust gas falls below the required level leading to condensation and corrosion
Solution Approach 1:
The patent implements variable geometry nozzles that can dynamically adjust their opening cross-section based on operating conditions. This allows the heat exchanger to adapt between maximum cooling mode (for waste heat utilization) and minimum temperature protection mode (preventing condensation and corrosion), resolving the contradiction between energy recovery and component protection
Solution Approach 2:
The system changes the geometric parameter of the nozzles (opening cross-section) to control the mass flow rate of the working fluid. By varying this parameter, the heat exchanger can operate at different cooling intensities, enabling it to maximize waste heat recovery when safe or protect against minimum temperature violations when at risk
2Object-affected harmful factors
If the heat exchanger is designed not to fall below the minimum temperature, then corrosion and condensation are prevented, but the exhaust gas potential is not fully utilized leading to reduced system efficiency
Solution Approach 1:
The variable geometry nozzles enable dynamic adjustment of the cooling capacity to match actual operating conditions. When exhaust gas temperature and flow conditions allow, the system maximizes heat recovery; when conditions approach minimum temperature thresholds, the nozzles adjust to maintain protective temperatures, thus achieving both corrosion prevention and maximum efficiency
Solution Approach 2:
The control system monitors operating parameters and automatically adjusts the nozzle geometry to maintain optimal operation. The system self-regulates between waste heat maximization and minimum temperature protection based on real-time conditions, eliminating the need for conservative fixed-design margins that would reduce efficiency
3Productivity
If different heat exchangers are used for different engines, then optimal performance for each engine is achieved, but standardization and use of equal parts is reduced leading to increased costs
Solution Approach 1:
The heat exchanger design incorporates variable geometry nozzles that can be adjusted to match different engine operating characteristics. This single universal design can adapt to multiple engine types and operating conditions, eliminating the need for engine-specific custom heat exchangers while maintaining optimal performance for each application
Solution Approach 2:
The adjustable nozzle geometry allows a standardized heat exchanger unit to dynamically adapt its performance characteristics to match different engines. Rather than requiring different fixed designs for different engines, the same physical unit can be configured through nozzle adjustment to optimize performance across various engine types and operating conditions
4Reliability
If redundant rotating machines such as pumps are used, then reliability is improved, but total costs increase
Solution Approach 1:
The patent removes the requirement for redundant rotating machines by extracting the critical function of maintaining minimum temperature and flow control into a passive variable geometry nozzle system. The nozzle geometry itself provides the flow control function that would otherwise require active pumping, eliminating the need for backup pumps while maintaining reliability
Solution Approach 2:
The variable geometry nozzles act as an intermediary mechanism that provides passive flow control and temperature maintenance. Instead of using active rotating machines (pumps) that would require redundancy for reliability, the nozzle geometry serves as a passive mediator that achieves the same protective function without mechanical 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 solution optimizes waste heat utilization, prevents corrosion, enhances system efficiency, and allows for standardized heat exchanger designs to accommodate different engines, reducing costs and logistical complexities.
Implementation Method 1
a first heat exchanger (11) for transferring heat from an exhaust gas flow of a combustion engine to a heat transfer medium
Implementation Method 2
transferring heat from an exhaust gas flow
Implementation Method 3
an Organic Rankine Cycle device (ORC) (60) with a third heat exchanger (13) for transferring heat from the heat transfer medium to a working medium of the thermodynamic circular processor
Implementation Method 4
to generate electrical or mechanical energy
Data Source
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AI summary
The invention relates to a device for utilizing the waste heat of a thermal processing device, in particular an internal combustion engine, comprising: a first heat exchanger for transferring heat from a heat flow of a thermal processing device, in particular an internal combustion engine, to a heat transfer medium; a second heat exchanger for transferring heat from the heat flow to a heat transfer medium, wherein the second heat exchanger is arranged downstream of the first heat exchanger with respect to the heat flow;a thermodynamic cycle device, in particular an Organic Rankine Cycle device, comprising a third heat exchanger for transferring heat from the heat transfer medium to a working medium of the thermodynamic cycle device and a fourth heat exchanger for transferring heat from the heat transfer medium to the working medium, wherein the fourth heat exchanger is arranged upstream of the second heat exchanger with respect to the flow of the working medium;wherein, in the third heat exchanger, the cooled heat transfer medium can be at least partially supplied to the first heat exchanger for heating, and wherein, in the fourth heat exchanger, the cooled heat transfer medium can at least partially be supplied to the second heat exchanger for heating. Furthermore, the device according to the invention comprises means for controlling the mass flow of the heat transfer medium flowing through the second or fourth heat exchanger. The invention further relates to a corresponding method for utilizing the waste heat of a thermal processing device, in particular an internal combustion engine.