Modular Air Conditioning With Thermal Storage for Engine-Stop Comfort
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Solution Overview
Problem
Existing thermal energy storage systems in vehicles fail to efficiently maintain passenger compartment comfort and engine efficiency during engine stops, leading to thermal discomfort and reduced fuel economy, while also increasing complexity and cost.
Innovation Solution
A thermal energy storage system that includes a refrigerant circuit with an evaporator and a coolant circuit with a coolant heat exchanger and auxiliary heat exchanger, in conjunction with a water-cooled charge air cooler (WCAC), allowing for efficient heat transfer and storage, thereby optimizing HVAC and WCAC efficiency and fuel economy.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a thermal energy storage system is added to maintain comfort during engine stops, then passenger compartment comfort is improved, but device complexity increases
Solution Approach 1:
The patent combines the thermal energy storage system with the existing engine coolant circuit by integrating a thermal storage tank and heat exchanger into the coolant loop. This merging approach allows the system to provide thermal energy storage functionality without creating a completely separate system, thereby improving comfort during engine stops while limiting the increase in device complexity by reusing existing infrastructure.
Solution Approach 2:
The coolant circuit is designed to serve multiple functions: engine cooling, thermal energy storage, and HVAC system support. The thermal storage tank integrated into the coolant circuit can store thermal energy during engine operation and release it during engine stops, while the same circuit continues to cool the engine. This multi-functionality improves reliability without proportionally increasing complexity.
2Use of energy by moving object
If a thermal energy storage system is added to maintain comfort during engine stops, then fuel economy is improved, but device complexity increases
Solution Approach 1:
The thermal energy storage system is merged with the existing engine coolant circuit and HVAC system. By integrating the thermal storage tank and heat exchanger into the existing infrastructure, the system can improve fuel economy through more efficient thermal management without requiring a completely separate complex system.
Solution Approach 2:
The system uses the engine's own coolant to charge and discharge the thermal storage tank. During engine operation, the coolant charges the thermal storage; during engine stops, the stored thermal energy is discharged to maintain comfort. This self-service approach improves fuel economy without requiring external energy sources or overly complex control systems.
3Use of energy by moving object
If the engine stops during idle mode to enhance fuel efficiency, then fuel economy is improved, but passenger compartment comfort deteriorates
Solution Approach 1:
The thermal energy storage system is charged with thermal energy during engine operation before the engine stops. This preliminary charging of the thermal storage tank ensures that when the engine stops during idle mode, there is already stored thermal energy available to maintain passenger compartment comfort, thus enabling fuel efficiency improvements without comfort deterioration.
Solution Approach 2:
The system converts the potential harm of engine stoppage (loss of HVAC cooling) into a benefit by using the thermal energy storage tank to provide the necessary cooling during idle mode. The thermal storage, charged during engine operation, becomes a beneficial resource that maintains comfort when the engine is stopped, thus converting what would be a harmful situation into a beneficial one.
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
The system provides effective air conditioning during engine stops, improves WCAC efficiency, and enhances fuel economy by minimizing complexity and cost, offering 45 seconds to 60 seconds of conditioned air and reducing charge air temperature by 3° C to 5° C.
Implementation Method 1
an evaporator receiving a flow of the refrigerant and a flow of air
Implementation Method 2
a coolant heat exchanger disposed downstream from the evaporator with respect of a direction of the flow of air through the evaporator
Implementation Method 3
an auxiliary heat exchanger receiving a flow of the coolant... and a WCAC in fluid communication with the auxiliary heat exchanger
Implementation Method 4
a cold storage device in heat exchange communication with the coolant circuit
Data Source
AI summary
A thermal energy storage system of a vehicle is disclosed. The thermal energy storage system includes a refrigerant circuit conveying a refrigerant therethrough. The refrigerant circuit includes an evaporator receives a flow of the refrigerant and a flow of air. The thermal energy storage system also includes a coolant circuit conveying a coolant therethrough. The coolant circuit includes a coolant heat exchanger disposed downstream from the evaporator with respect to a direction of the flow of air through the evaporator and an auxiliary heat exchanger receiving a flow of the coolant. The thermal energy storage system further includes a cold storage device in thermal communication with the coolant circuit and a WCAC in fluid communication with the auxiliary heat exchanger.