Multi-Pass Refrigerant Heat Exchanger With Bidirectional Flow Paths
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Solution Overview
Problem
Conventional vehicle air-conditioning system heat exchangers face challenges in optimizing refrigerant pressure levels to prevent freezing in heat pump mode, leading to increased pressure loss and reduced efficiency, while also requiring minimal additional costs and space.
Innovation Solution
A heat exchanger design with a first and second header pipe, allowing bidirectional pass flow and adjustable flow paths, featuring a movable separation component that changes flow direction based on operation mode, optimizing flow cross-sections and heat exchange surfaces to minimize pressure loss and prevent freezing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the heat exchanger uses a multi-pass design with small flow cross-section in cooling mode, then heat exchange efficiency is improved, but pressure loss increases in heat pump mode
Solution Approach 1:
The patent applies a movable separation component that can dynamically adjust the flow path configuration based on operation mode. In cooling mode, the separator creates multiple passes with smaller flow cross-sections for efficient heat exchange. In heat pump mode, the separator moves to create fewer passes with larger flow cross-sections, reducing pressure loss. This dynamic reconfiguration resolves the contradiction between heat exchange efficiency and pressure loss.
2Productivity
If the heat exchanger is designed for optimal cooling performance, then cooling efficiency is improved, but freezing risk increases in heat pump mode
Solution Approach 1:
The movable separation component enables dynamic adjustment of flow distribution. In heat pump mode, it reconfigures the flow paths to ensure adequate refrigerant flow through all heat exchange surfaces, preventing freezing while maintaining the compact multi-pass structure designed for cooling efficiency.
3Ease of manufacture
If the heat exchanger uses fixed flow paths, then manufacturing simplicity is maintained, but adaptability to different operation modes deteriorates
Solution Approach 1:
The patent introduces a movable separation component that can be positioned in different locations within the header pipe. This component is relatively simple in structure but provides significant adaptability, allowing the same heat exchanger body to optimize flow paths for both cooling and heat pump modes without requiring complex active control systems or multiple components.
4Volume of moving object
If the heat exchanger uses a compact multi-pass design, then space utilization is improved, but flow cross-section becomes insufficient in heat pump mode
Solution Approach 1:
The movable separation component allows the compact multi-pass structure to be reconfigured. When moved to a different position, it effectively increases the flow cross-section available in heat pump mode while maintaining the compact physical dimensions of the heat exchanger, thus resolving the contradiction between space utilization and flow cross-section adequacy.
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 design enhances heat output in cooling device mode, reduces the risk of freezing in heat pump mode, and maintains efficiency without additional manufacturing costs, ensuring optimal performance and reduced output loss.
Implementation Method 1
allow a pass flow in a multi-pass way and bidirectionally. The flow direction of a refrigerant within the heat exchanger depends on operation mode.
Implementation Method 2
a heat exchanger configured to operate as a condenser in cooling device mode and to discharge heat from a refrigerant to ambient air functions to absorb heat from ambient air as an evaporator in heat pump mode.
Implementation Method 3
the flow cross sections of the header pipes are closed by a small-sized and stamped plate. In this case, the small-sized plate corresponds to the separation component. By using the separation component, the heat exchanger is partitioned into, for example, 2 or 4 partial regions, so-called passes.
Implementation Method 4
In the accumulator, the phases of an almost condensed refrigerant are separated from each other.
Implementation Method 5
the refrigerant expands to a pressure level at which a corresponding saturation temperature is lower than temperature of ambient air. Accordingly, the refrigerant absorbs heat from the ambient air and discharges the absorbed heat.
Data Source
AI summary
The present invention relates to the heat exchanger 1 of refrigerant circuitry of an air-conditioning system for a vehicle, which enables a bidirectional pass flow. The air-conditioning system is configured to perform a combined operation of cooling device mode and heat pump mode, the heat exchanger 1 is formed in the form of a multi-pass, and the flow direction of a refrigerant varies depending on operation mode. The first heat exchanger 1 formed in the form of a multi-pass includes header pipes 2 and 3, flow paths assigned to respective passes, and means configured to partition an internal volume space of one or more header pipes 2 and 3 into independent regions. A first pass of the heat exchanger 1 has a greater flow cross section and greater heat exchange surface than the last pass.