Dual-Condenser Waste Heat Recovery System for Vehicle Thermal Management
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing waste heat recovery (WHR) systems face challenges in efficiently converting thermal energy to mechanical energy due to difficulties in regulating the cooling of the medium in air-cooled condensers, which require large space and are sensitive to surrounding air conditions, while coolant-cooled condensers struggle to achieve low temperatures.
Innovation Solution
A dual-condenser arrangement is implemented, where the medium is first cooled in a coolant-cooled condenser and then in an air-cooled condenser, allowing for efficient temperature regulation and reduced space requirements, with a separate cooling system using a low-temperature coolant circuit that can be controlled for optimal performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If an air-cooled condenser is used to cool the medium, then the medium can be cooled to a temperature close to the temperature of the surroundings, but it requires a relatively large fitting space at the front surface of the vehicle and is difficult to regulate
Solution Approach 1:
The condenser system is segmented into two separate condensers: a first air-cooled condenser and a second coolant-cooled condenser. The first condenser handles the initial cooling of the medium to near ambient temperature, while the second condenser provides additional cooling using a coolant circuit. This segmentation allows each condenser to be optimized for its specific function, reducing the overall space requirement while achieving the desired low temperature.
Solution Approach 2:
A coolant is introduced as an intermediary substance in the second condenser to transfer heat from the medium to the coolant circuit. This intermediary enables efficient heat transfer and allows the system to achieve lower temperatures than would be possible with air cooling alone, while maintaining a compact design.
2Temperature
If an air-cooled condenser is used to cool the medium, then the medium can be cooled to a temperature close to the temperature of the surroundings, but the cooling is difficult to regulate because the temperature and moisture of the surrounding air may vary
Solution Approach 1:
The coolant-cooled condenser system incorporates regulation mechanisms that can respond to temperature variations. By controlling the coolant flow and temperature through the second condenser, the system can compensate for variations in ambient conditions and maintain precise control over the medium's final temperature, achieving reliable regulation that overcomes the limitations of air-cooled systems.
3Ease of operation
If a coolant-cooled condenser is used to cool the medium, then the cooling can be regulated by adjusting the coolant's temperature and flow, but the medium cannot be cooled to as low a temperature as in an air-cooled condenser
Solution Approach 1:
The cooling process is divided into two stages: the first air-cooled condenser achieves the bulk of the cooling to near ambient temperature with excellent temperature control, while the second coolant-cooled condenser provides the final stage of cooling to reach the desired low temperature. This segmentation allows each condenser type to operate in its optimal performance range.
Solution Approach 2:
The system merges the advantages of both air-cooled and coolant-cooled condensers into a single integrated system. The air-cooled condenser provides stable temperature control and can achieve low temperatures, while the coolant-cooled condenser adds regulatory capability. Together, they overcome the limitations of either system used alone.
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 configuration enables efficient conversion of thermal energy to mechanical energy by achieving low temperatures in the medium, allowing for smaller air-cooled condensers and precise regulation of cooling, thereby enhancing the overall efficiency and compactness of the WHR system.
Implementation Method 1
the medium is first cooled in a coolant-cooled condenser
Implementation Method 2
thereafter in an air-cooled condenser... cooled by surrounding air
Implementation Method 3
When the medium expands through the turbine, part of the medium's thermal energy is converted to mechanical energy
Implementation Method 4
an evaporator in which the medium is vaporised by heat from a heat source
Implementation Method 5
The medium condenses in a condenser
Data Source
Figure 1
AI summary
The present invention relates to a system for converting thermal energy to mechanical energy in a vehicle. The system comprises a line circuit (35), a pump (36) for recirculating a medium in the line circuit, at least one evaporator (31, 32, 38) in which the medium is caused to absorb thermal energy from a heat source (4, 28) so that it becomes vaporised, a turbine (39) adapted to being driven by the vaporised medium in order to generate mechanical energy, and a condenser arrangement (24, 42) in which the medium is caused to give off thermal energy so that it condenses. The condenser arrangement comprises a first condenser (24) in which the medium gives off thermal energy to coolant which circulates in said cooling circuit, and a second condenser (42) which is situated downstream of the first condenser (24) with respect to the medium's direction of flow in the line circuit (35) and in which the medium gives off thermal energy to air at the temperature of the surroundings.