Clausius-Rankine Pump Capacity Control for Exhaust Energy Recovery
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Solution Overview
Problem
Existing methods for recuperating energy from internal combustion engine exhaust gases using the Clausius-Rankine cycle face challenges due to variable exhaust gas mass flow, making stable control of the working fluid circulation impossible.
Innovation Solution
A method where the pump capacity in the Clausius-Rankine cycle is controlled based on the exhaust gas mass flow and temperature, using performance graphs to adjust the pump performance in real-time, ensuring optimal heat energy transfer.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If mass flow control of the working fluid is implemented based on measured values, then energy recovery efficiency is improved, but control stability deteriorates due to inertness caused by the ratio of evaporator internal volume to mass flow
Solution Approach 1:
The pump capacity is made dynamically adjustable based on exhaust gas mass flow conditions. The controller continuously adapts the pump's volumetric flow rate to match varying exhaust gas availability, transforming a static system into a dynamic one that responds to changing operating conditions without suffering from control inertness
Solution Approach 2:
The system changes the key parameter of pump capacity (volumetric flow rate) to adapt to varying exhaust gas mass flow. By adjusting this parameter dynamically rather than maintaining constant control, the system overcomes the inertness problem while maximizing energy recovery from available exhaust heat
2Device complexity
If the working fluid circulation is maintained at constant volumetric flow, then system simplicity is preserved, but energy recovery efficiency deteriorates due to mismatch with variable exhaust gas mass flow
Solution Approach 1:
The pump capacity is made dynamically adjustable based on exhaust gas mass flow conditions. The controller continuously adapts the pump's volumetric flow rate to match varying exhaust gas availability, transforming a static system into a dynamic one that responds to changing operating conditions without suffering from control inertness
Solution Approach 2:
The system changes the key parameter of pump capacity (volumetric flow rate) to adapt to varying exhaust gas mass flow. By adjusting this parameter dynamically rather than maintaining constant control, the system overcomes the inertness problem while maximizing energy recovery from available exhaust heat
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 allows for reliable and stable energy recovery from exhaust gases, maximizing energy extraction by adapting pump capacity to the momentary exhaust gas conditions, enhancing the efficiency of the energy recuperation process.
Implementation Method 1
heat energy from the exhaust gas flow is supplied to the working fluid
Implementation Method 2
heat energy from the exhaust gas flow is supplied to the working fluid in order to vaporize the pressurized working fluid
Implementation Method 3
The vapor is condensed in a condenser to form a condensate
Data Source
AI summary
In a motor vehicle with an internal combustion engine providing a hot exhaust gas flow which is used as heat source for a Clausius-Rankine cycle process, wherein a pump is provided in the cycle for pumping, pressurizing and circulating an operating fluid, the pumping operation is controlled by a controller depending on the exhaust gas mass flow through an evaporator and possibly also the exhaust gas temperature to vaporize the operating fluid and expanding the vapor under pressure in an expander while generating energy. The vapor is condensed in a condenser to form a condensate which is again returned to the pump.