Refrigeration device
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Solution Overview
Problem
Conventional refrigeration devices consume excessive standby power due to unnecessary heating by the compressor heater, and existing solutions are either costly or complex in controlling the oil concentration and viscosity of the lubricating oil in the compressor.
Innovation Solution
A refrigeration device that controls the heater based on the saturation temperature of the refrigerant, setting an oil temperature target value by adding a predetermined offset to the saturation temperature, allowing for efficient maintenance of oil concentration and viscosity, and reducing standby power consumption without complex calculations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the heater is continuously energized to warm the compressor and prevent refrigerant stagnation, then the lubricating oil temperature is maintained and refrigerant dissolution is prevented, but the standby power consumption increases
Solution Approach 1:
The patent applies parameter changes by using a refrigerant pressure detector to detect pressure changes in the crank case, which serve as an indicator of refrigerant dissolution. Instead of continuously heating, the system changes the heater operation state based on detected pressure parameters, thereby reducing standby power while preventing refrigerant stagnation.
Solution Approach 2:
The patent implements feedback control by detecting refrigerant pressure in the crank case and using this information to control the heater operation. The control device adjusts the heater based on the detected pressure, creating a closed-loop system that maintains reliability while optimizing energy consumption.
2Manufacturing precision
If the heater control is based on complex solubility characteristic curves to accurately maintain oil concentration, then the lubricating oil quality is precisely controlled, but the device complexity and calculation load increase
Solution Approach 1:
The patent extracts the essential control function from complex solubility curves by using refrigerant pressure detection as a simplified indicator. Instead of implementing full solubility characteristic curve-based control, the system extracts the key parameter (pressure) that correlates with refrigerant dissolution, thereby reducing control system complexity while maintaining effective oil concentration control.
Solution Approach 2:
The patent replaces complex calculation-based control with a simpler, more economical approach using pressure detection. This substitution uses a straightforward detection method rather than expensive and complex computational systems, achieving the same protective function with reduced complexity.
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 simplifies heater control, reduces standby power consumption, and maintains appropriate oil concentration and viscosity, improving the reliability and efficiency of the refrigeration device while minimizing costs and calculation loads.
Implementation Method 1
a heater for heating lubricating oil in the compressor
Implementation Method 2
the proportion of the refrigerant dissolving into the lubricating oil in the crank case increases
Data Source
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AI summary
To provide, at a low cost, a refrigeration device in which an appropriate oil concentration or oil viscosity can be readily maintained with regards to lubricating oil in a compressor and in which a cut in standby power can be achieved. The compressor (40) compresses a refrigerant circulating between an indoor heat exchanger (21) and an outdoor heat exchanger (31). A crank case heater (46) heats the lubricating oil in the compressor (40). A control device (50) controls the crank case heater (46). The control device (50) controls the crank case heater (46) so that the oil temperature of the lubricating oil in the compressor (40) reaches an oil temperature target value obtained by adding an oil temperature offset value to the saturation temperature of the refrigerant in the compressor (40).