Refrigeration cycle device
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Solution Overview
Problem
Existing refrigeration cycle devices face inefficiencies and increased manufacturing costs due to the need for a bypass pipe and temperature detectors, which do not effectively contribute to refrigeration performance and fail to accurately detect changes in refrigerant composition.
Innovation Solution
A refrigeration cycle device with a controller that estimates pressure loss and calculates condenser pressure to detect changes in refrigerant composition by comparing saturation temperature with actual temperature, eliminating the need for specialized detection components and allowing for accurate composition monitoring.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a bypass pipe and temperature detector are added to detect refrigerant composition changes, then detection capability is improved, but manufacturing cost increases
Solution Approach 1:
The patent extracts the temperature detection function from a dedicated temperature detector and relocates it to the existing suction pipe of the compressor. This eliminates the need for a separate bypass pipe and dedicated temperature detector, thereby reducing manufacturing cost while maintaining the capability to detect refrigerant composition changes through temperature-pressure relationship analysis.
Solution Approach 2:
The suction pipe of the compressor is given a dual function: it serves both as a structural component of the compressor system and as a temperature detection location. By measuring the temperature of the refrigerant in the suction pipe and combining it with pressure data, the system can detect refrigerant composition changes without requiring additional specialized components.
2Measurement precision
If a bypass pipe is added to measure condensation and evaporation temperatures, then temperature measurement capability is improved, but refrigeration performance deteriorates
Solution Approach 1:
The suction pipe is utilized for temperature measurement purposes without diverting refrigerant flow. The existing refrigerant flow path remains intact, and the suction pipe's temperature is measured as it carries refrigerant between the evaporator and compressor, thus maintaining full refrigeration performance while enabling temperature detection for composition analysis.
3Measurement precision
If a bypass pipe with temperature detector is installed, then refrigerant composition detection is enabled, but device complexity increases
Solution Approach 1:
The patent removes the bypass pipe configuration and extracts only the essential temperature measurement function, placing it at the suction pipe location. This simplifies the system structure by eliminating additional pipes and dedicated detectors, while the controller processes the temperature and pressure data to detect refrigerant composition changes.
Solution Approach 2:
The temperature detection function is merged with the existing suction pipe structure of the compressor. The suction pipe serves both its original structural/flow function and the additional temperature sensing function, thereby reducing overall system complexity while maintaining detection capability.
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 enables cost-effective detection of refrigerant composition changes, preventing performance shortages and reducing energy consumption while maintaining reliable operation.
Implementation Method 1
a condenser pressure calculation part configured to estimate pressure loss from the discharge side of the compressor to a middle portion of the condenser based on a pressure detection value on the discharge side of the compressor, and to calculate pressure near the middle portion of the condenser based on the pressure detection value and the pressure loss
Implementation Method 2
a refrigerant composition detection part configured to estimate saturation temperature which is average temperature of dew and boiling points of the refrigerant, based on the pressure near the middle portion of the condenser, and to detect a change in the refrigerant composition based on a difference between the saturation temperature and a temperature detection value of the refrigerant near the middle portion of the condenser
Data Source
Figure 1
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AI summary
A controller of an air conditioner estimates pressure loss from a discharge side of a compressor (11) to an outlet of an outdoor heat exchanger (13) based on a pressure detection value on the discharge side of the compressor, and calculates pressure near the outlet of the outdoor heat exchanger based on the pressure detection value and the pressure loss. Furthermore, the controller estimates saturated liquid temperature of refrigerant based on the pressure near the outlet of the outdoor heat exchanger, and detects a change in a refrigerant composition based on a difference between the saturated liquid temperature and a temperature detection value of the refrigerant near the outlet of the outdoor heat exchanger.