Refrigeration apparatus
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Solution Overview
Problem
The existing refrigeration apparatuses face the challenge of excessively high refrigerant temperatures due to torque control in compressors, which leads to inefficiencies and increased thermal energy generation, especially under high condensation temperatures and pressure conditions.
Innovation Solution
A refrigeration apparatus with an inverter-controlled compressor motor that controls torque within a specific frequency range, utilizing a device controller to manage the refrigerant circuit conditions by placing the refrigerant in a wet vapor state or injecting intermediate-pressure refrigerant to reduce discharge temperatures, employing a pressure reducing mechanism and outdoor fan to adjust pressure and airflow.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If torque control is performed on the compressor motor through inverter control, then vibration in low-speed operation range is reduced, but motor efficiency decreases and thermal energy generation increases
Solution Approach 1:
The patent applies parameter changes by modifying the refrigerant state parameters (temperature, pressure, phase) to compensate for the adverse effects of torque control. Specifically, it controls the refrigerant to be in a wet vapor state or introduces intermediate-pressure refrigerant to lower the discharge temperature, thereby addressing the efficiency loss while maintaining vibration control benefits
Solution Approach 2:
The patent converts the harmful thermal energy generated by torque control into a beneficial effect by using it to adjust refrigerant properties. The heat generated during torque control is utilized to maintain refrigerant in optimal states for heat exchange, transforming waste energy into a functional advantage
2Stability of the object's composition
If torque control is performed on the compressor motor, then vibration is reduced, but temperature of refrigerant discharged from the compressor becomes excessively high
Solution Approach 1:
The patent directly addresses the temperature issue by changing the refrigerant state parameters. It controls the refrigerant to be in a wet vapor state before compression or introduces intermediate-pressure refrigerant during compression, which fundamentally alters the thermodynamic parameters and results in lower discharge temperatures despite torque control being active
Solution Approach 2:
The patent uses an intermediary substance (intermediate-pressure refrigerant) to mediate between the compression process and the discharge. This intermediary refrigerant absorbs excess heat during the compression process, preventing the discharge temperature from becoming excessively high while allowing torque control to continue
3Temperature
If the refrigerant is placed in a wet vapor state or intermediate-pressure refrigerant is injected, then discharge temperature is reduced, but device complexity increases
Solution Approach 1:
The patent achieves multi-functionality by using existing refrigerant circuit components (compressor, heat exchangers, expansion devices) to perform multiple roles. The same components that manage refrigerant flow and heat exchange are utilized to control refrigerant state for temperature reduction, eliminating the need for separate dedicated systems
Solution Approach 2:
The refrigerant circuit serves itself by using its own refrigerant and existing components to regulate discharge temperature. The system uses feedback from temperature and pressure sensors to automatically adjust refrigerant flow and state through existing control mechanisms, making the system self-regulating without external intervention
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 effectively reduces the risk of excessively high refrigerant temperatures during torque control, enhancing motor efficiency and reducing costs associated with temperature management, while allowing for easier control and operation even with refrigerants containing high percentages of R32.
Implementation Method 1
a built-in motor having rotation thereof controlled by inverter control
Implementation Method 2
an inverter controller that controls torque of the motor through the inverter control
Implementation Method 3
place the refrigerant sucked into the compressor in a wet vapor state
Implementation Method 4
temperature of outside air that is heat exchanged with refrigerant that flows through the refrigerant circuit
Implementation Method 5
an outdoor fan that is provided in the refrigerant circuit as one of the devices for supplying the outside air to be heat exchanged with the refrigerant
Implementation Method 6
a pressure reducing mechanism provided in the refrigerant circuit as one of the devices for reducing pressure of the refrigerant
Data Source
AI summary
To reduce the possibility that temperature of refrigerant discharged from a compressor of a refrigeration apparatus becomes excessively high by controlling torque of a motor built into the compressor, the compressor includes the motor having rotation thereof controlled by inverter control. An inverter controller controls torque of the motor using inverter control when operation frequency of the compressor is at least one value within a range of from 10 Hz to 40 Hz. When at least the operation frequency is within the range of from 10 Hz to 40 Hz, torque of the motor is controlled, and under a predetermined condition in which temperature of refrigerant discharged from the compressor easily becomes excessively high, a device controller controls devices provided in a refrigerant circuit such that refrigerant sucked into the compressor is placed in a wet vapor state.