Reversible Internal Heat Exchanger for Refrigerant Circuit
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The existing refrigerant circuits in motor vehicles face issues with overheating of the refrigerant fluid at the compressor inlet during heating mode, leading to potential damage and prolonged defrosting times due to icing of the outdoor exchanger, which is inefficiently addressed by operating in cooling mode.
Innovation Solution
A refrigerant circuit with a reversible internal exchanger system, utilizing two-way valves and reversible expansion members to reverse the refrigerant fluid's direction of circulation, allowing for adaptive pressure management within the internal exchanger branches, enabling efficient heating and cooling modes while reducing refrigerant fluid temperature at the compressor inlet and accelerating defrosting.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If the internal exchanger is used in heating mode to improve thermodynamic performance, then heating efficiency is improved, but the refrigerant fluid temperature at compressor inlet increases causing overheating
Solution Approach 1:
The patent applies inversion by reversing the flow direction of refrigerant in the external exchanger during defrosting operations. Instead of maintaining the normal heating mode flow, the system inverts the flow to send hot refrigerant through the external exchanger to rapidly melt ice, thereby solving the overheating issue by controlling when and how the internal exchanger operates in heating mode.
Solution Approach 2:
The system dynamically adjusts the operating mode of the internal exchanger based on real-time conditions. The control unit monitors temperatures and flow directions, switching between heating mode, cooling mode, and defrosting mode as needed. This dynamic adaptation prevents sustained overheating while maintaining heating efficiency when conditions are appropriate.
2Reliability
If the loop operates in cooling mode to defrost the outdoor exchanger, then the outdoor exchanger is defrosted, but the defrosting time is too long
Solution Approach 1:
The system performs preliminary heating of the refrigerant fluid before directing it to the outdoor exchanger for defrosting. By pre-heating the refrigerant in the internal exchanger or through compression heat, the system prepares high-temperature refrigerant ready for immediate defrosting operation, reducing the time required to melt ice on the outdoor exchanger.
Solution Approach 2:
The patent converts the harmful effect of hot refrigerant (which causes overheating during normal heating mode) into a beneficial resource for rapid defrosting. The high-temperature refrigerant that would otherwise be problematic is redirected to the outdoor exchanger during defrost cycles, where its heat rapidly melts ice, turning a potential harm into a useful defrosting mechanism.
3Reliability
If the refrigerant fluid temperature at compressor inlet is reduced to prevent overheating, then compressor safety is improved, but heating performance may be compromised
Solution Approach 1:
The patent segments the heating function into two separate paths: one through the internal exchanger for normal heating operations, and another through the external exchanger for defrosting and temperature control. This segmentation allows the system to maintain heating performance through the internal exchanger while using the external exchanger to manage refrigerant temperature and protect the compressor, preventing the need to compromise overall heating performance.
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 allows for safe operation of the compressor at high speed and compression ratio during heating mode, reduces the risk of overheating, and significantly accelerates the defrosting process by reversing the refrigerant flow direction in the external exchanger, ensuring efficient thermodynamic performance.
Implementation Method 1
an internal exchanger (21) comprising a first branch (22) capable of being traversed by the refrigerant fluid which exchanges heat with a second branch (23) of the internal exchanger capable of being traversed by the refrigerant fluid
Implementation Method 2
a first expansion member (20) being connected to a first orifice (24) of the first branch and a second expansion member (26) is connected to a second orifice (25) of the first branch
Implementation Method 3
a compressor (2)
Implementation Method 4
a first interior exchanger (3) intended to heat an interior air flow (4) sent into a motor vehicle passenger compartment, a second interior exchanger (12) intended to heat or cooling said internal air flow (4)
Data Source
Figure 1
Figure 2
Figure 3
AI summary
The invention relates to a circuit (1) capable of having a coolant flow therethrough, including: a compressor (2); a first internal heat exchanger (3) for heating an inner airflow (4) sent into a passenger compartment of a motor vehicle; a second internal heat exchanger (12) for heating or cooling said inner airflow (4); an internal heat exchanger (21) including a first branch (22) which is capable of having a coolant flow therethrough and which exchanges heat with a second branch (23) of the internal heat exchanger (21) capable of having a coolant flow therethrough; and an external heat exchanger (27), characterized in that it includes means (8, 9, 13, 18, 34, 37) arranged so as to reverse the direction of flow of the coolant in the first branch (22) of the internal heat exchanger (21), a first pressure-release member (20) connected to a first opening (24) of the first branch (22), and a second pressure-release member (26) connected to a second opening (25) of the first branch (22). The invention can be used in motor vehicles.