ORC Waste Heat Recovery for Rapid Engine Warm-Up
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Solution Overview
Problem
Internal combustion engine waste heat is largely lost, leading to inefficient fuel consumption and increased CO2 emissions, particularly during cold starts when heat loss is significant.
Innovation Solution
An organic Rankine cycle (ORC) system that captures waste heat from engine exhaust and power electronics to rapidly warm the engine by directing vaporized ORC fluid through the engine block during cold starts and redirecting it away once optimal temperature is reached, utilizing a dual-layer jacket for enhanced thermal management.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the engine cooling system operates continuously to maintain safe operating temperature, then engine safety is ensured, but fuel efficiency deteriorates during cold starts due to significant heat loss
Solution Approach 1:
The system dynamically adjusts coolant flow routing based on engine temperature conditions. During cold starts, the thermostat directs coolant flow through the ORC heat exchanger instead of the traditional radiator, enabling rapid engine warming. Once optimal temperature is reached, the system switches to normal cooling operation, thus adapting the thermal management strategy to current operating conditions to optimize fuel efficiency while maintaining engine safety
Solution Approach 2:
The system converts the harmful waste heat that would otherwise be lost to the environment into a beneficial resource for rapid engine warm-up. By capturing exhaust heat through the ORC cycle and redirecting it to heat the engine block and coolant during cold starts, the system transforms energy waste into a useful heating source, reducing fuel consumption and emissions
2Use of energy by moving object
If waste heat is captured and directed to warm the engine during cold starts, then fuel efficiency improves, but system complexity increases due to additional ORC components
Solution Approach 1:
The ORC system is designed to perform multiple functions: it generates electricity through the expansion engine, captures waste heat from exhaust, and provides thermal management for the engine block and coolant. By integrating these functions into a single system, the patent reduces overall system complexity compared to having separate systems for each function, while still achieving improved fuel efficiency through waste heat utilization
3Reliability
If the thermostat maintains coolant temperature for safe operation, then engine reliability is ensured, but heat loss to environment increases during cold conditions
Solution Approach 1:
The ORC heat exchanger acts as an intermediary component that captures waste heat from the exhaust stream and transfers it to the engine coolant and block. This intermediary heat transfer mechanism enables the system to reduce heat loss to the environment by redirecting it back to the engine, while the thermostat continues to maintain reliable temperature control
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 significantly reduces fuel consumption and CO2 emissions by efficiently utilizing waste heat to quickly warm the engine, improving fuel efficiency and reducing heat loss in cold conditions.
Implementation Method 1
An organic Rankine cycle (ORC) system that captures waste heat from engine exhaust and power electronics to rapidly warm the engine
Implementation Method 2
The ORC loop is configured to direct vaporized ORC fluid through the engine block when the engine is operating below a pre-determined temperature
Implementation Method 3
The system can also include an expander configured to decrease pressure of vaporized ORC fluid, the expander being in mechanical communication with an electric generator
Implementation Method 4
The engine loop is configured to direct engine coolant heated, directly or indirectly by the ORC loop, through the engine only when the engine is operating below a pre-determined temperature
Data Source
AI summary
A system for rapidly heating a vehicle engine when the engine is below a pre-determined temperature allows for improved fuel efficiency after a vehicle cold-start. The system includes an organic Rankine cycle (ORC) loop having a two-phase ORC fluid traveling circuitously through a conduit. The ORC fluid is vaporized by a power electronics cooling device and by an evaporator in thermal communication with exhaust waste heat. The vaporized ORC fluid is passed through an expander to generate electrical power. When the vehicle engine is below the pre-determined temperature, heat from the vaporized ORC fluid is transferred directly or indirectly to the engine. When the vehicle engine is at or above the pre-determined temperature, heat from the vaporized ORC fluid is instead transferred to an alternate heat sink.