Refrigeration and air-conditioning device
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Solution Overview
Problem
Existing refrigerating and air-conditioning apparatuses face challenges in performing a defrosting operation while maintaining heating and ensuring appropriate ventilation, leading to discomfort and potential inefficiencies due to temperature drops and ventilation issues during frost formation.
Innovation Solution
A refrigerating and air-conditioning apparatus with multiple independent refrigeration cycles, including a compressor, four-way valve, outdoor and indoor heat exchangers, and a controller that manages ventilation dampers to maintain required ventilation levels and prevent temperature drops during defrosting operations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If air passing through indoor heat exchangers is mixed and blown out by a shared indoor fan during defrosting operation, then defrosting can be performed, but the blow-out air temperature is lowered causing discomfort to passengers
Solution Approach 1:
The patent divides the single indoor fan system into separate indoor fans for each refrigeration cycle system. Each indoor unit has its own fan that operates independently, allowing the heating side to maintain normal blow-out air temperature while the defrosting side performs defrosting operation without affecting the heating air quality.
2Reliability
If outside air is blown to outdoor heat exchanger during defrosting operation, then defrosting can be performed, but condensing temperature does not rise when outside air temperature is low, causing defrosting to fail
Solution Approach 1:
The patent introduces a damper as an intermediary device to control the flow of outside air to the outdoor heat exchanger. The damper can be opened or closed based on operating conditions, allowing the system to prevent cold outside air from entering during defrosting operation when low condensing temperature would prevent effective defrosting.
Solution Approach 2:
The system dynamically adjusts the damper position based on real-time operating conditions. During defrosting operation, the damper is controlled to close to prevent cold outside air from entering, while during normal heating operation, the damper is opened to allow ventilation. This dynamic control ensures condensing temperature remains sufficient for defrosting to occur effectively.
3Stability of the object's composition
If ventilation damper is closed during defrosting operation to prevent temperature drop, then indoor temperature stability is improved, but appropriate ventilation amount cannot be ensured
Solution Approach 1:
The patent segments the ventilation control for each refrigeration cycle system independently. The defrosting side closes its damper to maintain indoor temperature stability, while the heating side opens its damper to compensate for the reduced ventilation, ensuring the total ventilation amount remains appropriate for the occupied space.
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
Enables simultaneous defrosting and heating operations, maintaining comfort by controlling ventilation and preventing temperature drops, thus improving heating performance and ventilation efficiency even under frost-forming conditions.
Implementation Method 1
an outdoor heat exchanger 5a, 5b, an indoor heat exchanger 7a, 7b
Implementation Method 2
a four-way valve 4a, 4b
Implementation Method 3
a compressor 3a, 3b
Implementation Method 4
a pressure reducing device 6a, 6b
Data Source
Figure 1~2
Figure 3
Figure 4~7
AI summary
To provide a refrigerating and air-conditioning apparatus that is capable of, even during a heating operation under air conditions leading to formation of frost, performing a defrosting operation while simultaneously continuing a heating operation and that improves comfort through heating by ensuring an appropriate amount of ventilation. A plurality of refrigeration cycles that are capable of independently performing a heating operation and a defrosting operation, are provided. A ventilation damper of an indoor unit in which a refrigeration cycle that performs a defrosting operation is installed is closed during a defrosting operation, and a ventilation damper of an indoor unit in which a refrigeration cycle that performs a heating operation is installed is controlled to achieve a required amount of ventilation corresponding to the indoor ventilation state.