Reheating method for operating a refrigeration system for a motor vehicle, refrigeration system, and motor vehicle having a refrigeration system of this type
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing refrigeration systems with heat pump functions in motor vehicles face challenges in efficiently meeting increasing heating demands, particularly at lower ambient temperatures, where the heat transferred at the evaporator and/or via the compressor is insufficient.
Innovation Solution
A reheating method that incorporates at least one additional heat sink, such as a chiller or an external heat exchanger, in parallel or series with the evaporator, allowing for the withdrawal of heat from a coolant or ambient air, thereby increasing the refrigerant's temperature and pressure, and enhancing the heating power of the system.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If heat is transferred solely at the evaporator and via the compressor, then the system structure remains simple, but the heating power is insufficient at lower ambient temperatures
Solution Approach 1:
The patent combines the evaporator with an additional heat sink (such as a chiller or external heat exchanger) into a integrated component that serves dual functions: cooling the refrigerant and extracting heat from the ambient environment or coolant. This merging allows the system to achieve higher heating power without proportionally increasing system complexity.
Solution Approach 2:
The additional heat sink is designed to perform multiple functions: it acts as a heat source for the refrigerant during heating operations, and can simultaneously serve as a cooling device or heat exchanger with the ambient environment. This multi-functionality enables the system to meet varying thermal demands while maintaining a compact structure.
2Temperature
If the refrigeration system operates at lower ambient temperatures, then the system can function in colder environments, but the heat transfer efficiency decreases
Solution Approach 1:
The system performs preliminary heat extraction at the additional heat sink before the refrigerant enters the evaporator. This preliminary action pre-heats the refrigerant and recovers heat from the ambient environment or coolant, reducing the energy loss that would otherwise occur in cold ambient conditions and improving overall heat transfer efficiency.
Solution Approach 2:
The patent changes the thermal parameters of the refrigerant by introducing an additional heat exchange path through the heat sink. This allows the refrigerant to gain heat from alternative sources (coolant or ambient air) when ambient temperature is low, thereby maintaining heat transfer efficiency across a wider temperature range.
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 method allows for optimized operation of the refrigeration system by increasing the heating power and compressor drive power, while maintaining a compact system design with few active components, even at lower ambient temperatures.
Implementation Method 1
The heating register is a heat source in which heat stored in the refrigerant is emitted to another medium, such as air
Implementation Method 2
an evaporator, which is arranged in the primary line
Implementation Method 3
the air cooled and dehumidified by the evaporator
Implementation Method 4
the temperature and the pressure of the refrigerant are increased in the refrigeration system, so that the heating power enabled by the refrigeration system
Implementation Method 5
an external heat exchanger, which is arranged in the primary line
Data Source
AI summary
A reheating method for operating a refrigeration system for a motor vehicle. The refrigeration system includes a refrigerant compressor, connected to a primary line and a secondary line; an external heat exchanger; an evaporator; a heating register; at least one movable temperature flap; and at least one shutoff element, which is arranged downstream of the heating register in the secondary line. The reheating method includes following steps: setting the at least one shutoff element in a position in which the refrigerant flows into the evaporator downstream of the heating register while bypassing the external heat exchanger, and incorporating at least one further heat sink, which is fluidically arranged in parallel or in series to the evaporator, in particular a chiller operating as a water heat pump evaporator and/or the external heat exchanger operating as an air heat pump evaporator.