Rail Vehicle Cooling and Air Conditioning Assembly
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Solution Overview
Problem
Rail vehicles equipped with traction batteries face challenges in maintaining optimal temperature for battery longevity and efficient cooling, especially in high ambient temperatures, while also needing to comply with regulations regarding refrigerants that pose safety hazards and increase space and energy consumption.
Innovation Solution
A rail vehicle design incorporating a combined cooling and air conditioning arrangement with a coolant circuit and refrigerant circuit, utilizing a common coolant cycle for both interior air conditioning and battery cooling, featuring multiple heat exchangers and valves to manage coolant flow efficiently, and a redundant refrigerant circuit for reliability, allowing for efficient use of waste heat and reduced energy consumption.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If a separate chiller is integrated into the traction battery container for cooling the energy storage device, then the cooling function is ensured, but the space required for the container increases and costs increase
Solution Approach 1:
The patent combines the air conditioning system and battery cooling system into a single integrated thermal management system. The refrigerant circuit serves dual purposes: cooling the passenger compartment through the evaporator and cooling the battery through the heat exchanger connected to the battery cooling device. This merging eliminates the need for a separate chiller, reducing container space and costs while maintaining effective temperature control for both functions.
Solution Approach 2:
The refrigerant circuit is designed with multi-functionality to perform both air conditioning and battery cooling operations. The compressor, condenser, and expansion valve serve the entire system, while the evaporator handles cabin cooling and the heat exchanger handles battery cooling. This universal system replaces the need for separate dedicated cooling systems, optimizing space utilization in the rail vehicle.
2Adaptability or versatility
If flammable refrigerants are used in the air conditioning system to comply with EU Regulation No. 517/2014, then environmental regulations are met, but the safety risk increases
Solution Approach 1:
The patent introduces an intermediary safety system comprising multiple sensors (temperature sensors in the battery compartment and refrigerant circuit, pressure sensors) and a control unit that monitors the system continuously. This intermediary detection and control mechanism enables the safe use of flammable refrigerants by detecting potential hazards early and triggering safety protocols, thus reconciling regulation compliance with safety requirements.
Solution Approach 2:
The system implements continuous feedback through temperature sensors and pressure sensors that monitor battery temperature, refrigerant temperature, and system pressure. The control unit receives this feedback and adjusts system operation accordingly, shutting down or activating safety measures when threshold values are exceeded. This feedback mechanism allows the system to operate safely with flammable refrigerants while meeting environmental regulations.
3Device complexity
If a common refrigerant circuit is used for both air conditioning and battery cooling, then costs and space requirements are reduced, but the system complexity increases
Solution Approach 1:
The patent segments the thermal management system into distinct functional modules: the refrigerant circuit with compressor, condenser, and expansion valve; the evaporator for air conditioning; the heat exchanger for battery cooling; and the battery cooling device with pump and valves. This segmentation allows each component to be manufactured and tested independently, simplifying the overall manufacturing process despite the integrated nature of the system, while controlling costs and space requirements.
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 ensures safe and efficient operation by maintaining battery temperature within defined limits, reducing space and energy requirements, and enhancing the range of the rail vehicle by optimizing energy storage capacity, while adhering to safety regulations and minimizing hazards from flammable refrigerants.
Implementation Method 1
a first heat exchanger which is arranged in the coolant circuit and in the first refrigerant circuit and in which the coolant can be cooled by means of the refrigerant
Implementation Method 2
a second heat exchanger, wherein a space usable by at least one person can be air-conditioned by means of a forced airflow through the second heat exchanger
Implementation Method 3
a cooling device which serves to cool the energy storage device, wherein a liquid coolant is circulating in the coolant circuit
Data Source
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AI summary
The invention relates to a rail vehicle having at least one energy accumulator, in which electrical energy for supplying a traction device can be stored, a cooling device, which is arranged in a coolant circuit and cools the energy accumulator, wherein a liquid coolant can circulate in the coolant circuit, and a refrigeration device having a first refrigerant circuit in which a refrigerant can circulate. The rail vehicle also has a first heat exchanger, which is arranged in the coolant circuit and in the first refrigerant circuit and in which the coolant can be cooled by means of the refrigerant, an air-conditioning device having a second heat exchanger, wherein a space usable by at least one person can be air-conditioned by means of a forced air-conditioning air flow guided through the second heat exchanger, as well as a control device. According to the invention, the second heat exchanger is arranged solely in the coolant circuit and is connected downstream of the first heat exchanger in the flow direction of the coolant.