Refrigeration system for a vehicle, comprising a refrigerant circuit having a heat exchanger, and heat exchanger for such a refrigeration system
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing refrigeration systems for vehicles face challenges in achieving optimal flow and performance in both AC and heat pump modes, particularly in minimizing pressure losses and ensuring homogeneous temperature distribution across the heat exchanger surface.
Innovation Solution
A refrigeration system with a double-flow heat exchanger featuring multiple refrigerant connections and a unidirectional valve member, allowing for controlled refrigerant flow between the connections to optimize flow in both AC and heat pump modes, with additional refrigerant outlets for enhanced performance and reduced pressure losses.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a double-flow heat exchanger is used with separation elements to divide refrigerant flow, then the heat exchanger can operate in both AC mode and heat pump mode, but the pressure losses increase and temperature distribution becomes non-uniform
Solution Approach 1:
The heat exchanger incorporates movable separation elements that can dynamically change position to reconfigure the refrigerant flow paths. This dynamic adjustment allows the system to optimize flow distribution for different operating modes (AC vs. heat pump), reducing pressure losses while maintaining versatility. The separation elements can be shifted to create different numbers of parallel flows based on the required operating condition.
Solution Approach 2:
The system changes the flow configuration parameters by adjusting the position of separation elements within the manifolds. This parameter change allows transformation between single-flow and multi-flow configurations, optimizing the refrigerant distribution for minimal pressure loss in each specific operating mode while preserving the ability to switch between AC and heat pump modes.
2Loss of energy
If the heat exchanger operates in single-flow mode for heat pump mode, then pressure losses are reduced, but temperature distribution across the heat exchanger surface becomes non-uniform
Solution Approach 1:
The heat exchanger is segmented into multiple flow channels by adjustable separation elements. Even in heat pump mode, the separation elements can be positioned to create multiple parallel flows that distribute refrigerant more uniformly across the heat exchanger surface, preventing non-uniform temperature distribution while maintaining relatively low pressure losses through optimized flow paths.
Solution Approach 2:
The separation elements can be positioned asymmetrically within the manifolds to create unequal flow distributions that compensate for the inherent asymmetry in single-flow operation. This asymmetric positioning ensures more uniform refrigerant distribution across the heat exchanger surface, addressing the temperature uniformity issue while preserving the low pressure loss benefit of single-flow mode.
3Productivity
If multiple separation elements are used to create multiple flows in AC mode, then heat transfer efficiency is improved, but the device complexity increases
Solution Approach 1:
The separation elements serve multiple functions: they divide the manifold cavity into chambers, create parallel refrigerant flows, and can be repositioned to adapt to different operating modes. This multi-functionality allows the heat exchanger to achieve high heat transfer efficiency through multiple flows in AC mode without proportionally increasing device complexity, as the same components enable both flow division and mode adaptability.
Solution Approach 2:
The separation elements are nested within the manifold structure, with multiple separation elements positioned sequentially within the same manifold cavity. This nested arrangement allows multiple flows to be created without adding external components, maintaining compact structure while achieving high heat transfer efficiency through increased flow parallelism.
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 operates with minimal pressure loss in heat pump mode, minimizing frosting risk and achieving efficient refrigerant mass flow, while maintaining high performance in AC mode with improved temperature distribution and reduced energy consumption.
Implementation Method 1
to control the flow of the refrigerant from the second refrigerant connection to the first refrigerant connection a unidirectional valve member fluidically connects the second refrigerant connection to the first refrigerant connection
Implementation Method 2
a double-flow heat exchanger with two manifolds arranged in parallel and spaced apart from each other, between which multiple heat exchanger (flat) tubes are placed and produce a fluidic connection with the manifolds
Implementation Method 3
the heat exchanger is switched between an evaporator mode for a heat pump mode and a condenser/gas cooler mode for a refrigeration system operation
Data Source
AI summary
A refrigeration system for a vehicle including a refrigerant circuit having a double-flow heat exchanger, it being possible to operate the heat exchanger as a refrigerant condenser/gas cooler for an AC mode or as an air heat pump evaporator for a heat pump mode. The first flow of the heat exchanger has a first refrigerant connection and the second flow of the heat exchanger has a second refrigerant connection. For double flow through the heat exchanger in AC mode the first refrigerant connection is a refrigerant inlet and the second refrigerant connection is a refrigerant outlet. For single flow through the heat exchanger in heat pump mode the second refrigerant connection is a refrigerant inlet.