Cooling/heating switching unit and air conditioner including the same
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Solution Overview
Problem
Existing refrigerant leak detection methods in multi-system air conditioners are complicated and prone to inaccuracies due to temperature variations, especially in the cooling/heating switching unit with numerous pipe connections, making reliable detection challenging.
Innovation Solution
A cooling/heating switching unit with a refrigerant-flow-direction control device, housed in an insulated unit, and equipped with refrigerant leak detection sensors installed outside the housing to detect leaks near the fittings and pipe connections, simplifying the detection process.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If temperature sensors are installed in the outdoor unit and indoor unit to detect refrigerant leaks, then refrigerant leak detection capability is provided, but measurement accuracy deteriorates due to temperature variations from seasons, time of day, and refrigerant circulation
Solution Approach 1:
The patent extracts the temperature sensor from the temperature-varying environment (outdoor unit and indoor unit) and relocates it to a thermally stable location (control device housing). This allows the sensor to measure ambient temperature accurately without being influenced by refrigerant temperature fluctuations or seasonal variations, thereby resolving the contradiction between providing leak detection capability and maintaining measurement accuracy
Solution Approach 2:
The control device housing serves as an intermediary thermal environment between the volatile temperature zones (outdoor unit, indoor unit) and the sensor. By placing the sensor inside this intermediary space, the system achieves accurate ambient temperature measurement while still enabling refrigerant leak detection through comparison with outdoor unit temperature
2Reliability
If temperature sensors are installed in each indoor unit of a multi-system air conditioner, then refrigerant leak detection can be performed for each unit, but the detection flow becomes complicated
Solution Approach 1:
The patent merges the temperature measurement function and refrigerant leak detection function into a single control device. By consolidating these functions and placing the temperature sensor in the control device housing, the system achieves comprehensive leak detection coverage across multiple indoor units while simplifying the detection flow to a single centralized process rather than multiple distributed processes
3Adaptability or versatility
If a cooling/heating switching unit with numerous pipe connections is used to enable simultaneous cooling and heating, then system versatility is improved, but refrigerant leak detection reliability deteriorates due to the complexity of pipe connections
Solution Approach 1:
The patent extracts the temperature sensor from the complex pipe connection environment of the cooling/heating switching unit and relocates it to the control device housing. This extraction eliminates the interference of numerous pipe connections from the temperature measurement process, thereby maintaining reliable leak detection capability while preserving the versatile simultaneous cooling and heating functionality
Solution Approach 2:
The control device housing acts as an intermediary that separates the temperature measurement function from the complex refrigerant distribution system. This intermediary placement allows the sensor to accurately measure ambient temperature without being affected by the thermal variations from multiple pipe connections, ensuring reliable leak detection in the versatile multi-system configuration
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 solution enables simple and reliable detection of refrigerant leaks, reducing the complexity of the detection flow and improving accuracy by isolating the leak detection sensors from temperature variations and pipe complexities.
Implementation Method 1
a heat insulating material that fills inside of the housing to insulate the refrigerant pipe arranged inside of the housing from heat
Implementation Method 2
a refrigerant leak detection sensor that is installed outside of the housing to detect leaked refrigerant
Data Source
AI summary
A cooling/heating switching unit includes first to third fittings, expansion valves and expansion-valve driving sections, a housing, a heat insulating material, and a refrigerant leak detection sensor. The first and second fittings respectively connect with a high/low-pressure-gas main pipe and a low-pressure-gas main pipe, which are linked to an outdoor unit. The third fitting connects with an indoor-unit connection pipe, which is linked to indoor units. The expansion valve for high/low-pressure-gas pipe, the expansion valve for low-pressure-gas pipe, and expansion-valve driving sections selectively connect the first or second fitting with the third fitting via a refrigerant pipe to control a flow direction of refrigerant. The housing houses the refrigerant pipe. The heat insulating material fills inside of the housing to insulate the refrigerant pipe arranged inside of the housing from heat. The refrigerant leak detection sensor is installed outside of the housing to detect leaked refrigerant.