Vehicle HVAC Expansion Valve Control With Shared Refrigerant Sensing
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Solution Overview
Problem
The existing air conditioning devices for vehicles face challenges in size increase and manufacturing cost due to the presence of multiple temperature and pressure detectors in each expansion valve, which affects cooling and heating efficiency.
Innovation Solution
An air conditioning device with a single temperature sensor and pressure sensor in the inter-expansion valve line, connected to both expansion valves, allowing for controlled opening degrees based on refrigerant state quantity, reducing the number of detectors and device size while enhancing cooling and heating efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If temperature detector and pressure detector are provided in each expansion valve, then cooling and heating capacity are enhanced, but device size increases and manufacturing cost increases
Solution Approach 1:
A single temperature detector and pressure detector are installed in the refrigerant line to serve both expansion valves. The detector measures refrigerant state quantities that are used by the controller to control the opening degrees of both the first and second expansion valves, allowing one detector to perform the function of what would traditionally require two detectors.
Solution Approach 2:
The detection functions for both expansion valves are merged into a single detection system. The temperature detector and pressure detector are combined in one location (the refrigerant line) rather than being distributed across two separate expansion valves, reducing the total number of detectors and device size while still providing the necessary control data for both valves.
2Productivity
If temperature detector and pressure detector are provided in each expansion valve, then cooling and heating efficiency are enhanced, but manufacturing cost increases
Solution Approach 1:
A single temperature detector and pressure detector are installed in the refrigerant line to serve both expansion valves. The detector measures refrigerant state quantities that are used by the controller to control the opening degrees of both the first and second expansion valves, allowing one detector to perform the function of what would traditionally require two detectors.
Solution Approach 2:
The detection functions for both expansion valves are merged into a single detection system. The temperature detector and pressure detector are combined in one location (the refrigerant line) rather than being distributed across two separate expansion valves, reducing the total number of detectors and device size while still providing the necessary control data for both valves.
3Measurement precision
If temperature detector and pressure detector are provided in each expansion valve, then valve operation accuracy is improved, but device complexity increases
Solution Approach 1:
A single temperature detector and pressure detector are installed in the refrigerant line to serve both expansion valves. The detector measures refrigerant state quantities that are used by the controller to control the opening degrees of both the first and second expansion valves, allowing one detector to perform the function of what would traditionally require two detectors.
Solution Approach 2:
The detection functions for both expansion valves are merged into a single detection system. The temperature detector and pressure detector are combined in one location (the refrigerant line) rather than being distributed across two separate expansion valves, reducing the total number of detectors and device size while still providing the necessary control data for both valves.
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 configuration suppresses the increase in device size and manufacturing cost while improving cooling and heating capacity and efficiency by accurately controlling the expansion valves' opening degrees using a single set of detectors.
Implementation Method 1
only one temperature sensor provided in the inter-expansion valve line or the inter-expansion valve connection line to detect a temperature of the refrigerant
Implementation Method 2
only one pressure sensor provided in the inter-expansion valve line or the inter-expansion valve connection line to detect a pressure of the refrigerant
Implementation Method 3
an indoor evaporator that performs heat exchange between the refrigerant and the indoor air to heat and evaporate the refrigerant
Implementation Method 4
an indoor evaporator that performs heat exchange between the refrigerant and the indoor air
Implementation Method 5
an indoor condenser that performs heat exchange between the refrigerant and indoor air to cool and condense the refrigerant
Implementation Method 6
an indoor condenser that performs heat exchange between the refrigerant and indoor air
Implementation Method 7
an outdoor heat exchanger that performs heat exchange between the refrigerant and outside air to function as a condenser that cools and condenses the refrigerant during cooling and function as an evaporator that heats and evaporates the refrigerant during heating
Implementation Method 8
an outdoor heat exchanger that performs heat exchange between the refrigerant and outside air
Implementation Method 9
a compressor that compresses a refrigerant
Implementation Method 10
a second expansion valve that expands the refrigerant in a liquid phase
Data Source
AI summary
This air conditioning device for a vehicle has: an indoor condenser; an indoor evaporator; a first expansion valve; a second expansion valve; a refrigerant line; an expansion valve control detector; and a controller. The expansion valve control detector is constituted by: only one temperature sensor that detects the temperature of refrigerant in an inter-expansion valve line of the refrigerant line; and only one pressure sensor that detects the pressure of the refrigerant in the inter-expansion valve line. During a cooling operation, the controller issues, to the first expansion valve, an opening command corresponding to a state quantity of the refrigerant that has been detected by the expansion valve control detector, and during a heating operation, the controller issues, to the second expansion valve, an opening command corresponding to a state quantity of the refrigerant that has been detected by the expansion valve control detector.