Method of controlling a refrigerator
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Solution Overview
Problem
Existing refrigerator control methods result in significant temperature variations within storage compartments, leading to reduced food freshness and difficulties in precise temperature control due to the installation position of temperature sensors, especially when using sensors with lower resolution.
Innovation Solution
A method of controlling the refrigerator by varying the output of the cooling unit and its operating times based on calculated average temperatures, adjusting the first and second reference times to maintain a constant storage compartment temperature, thereby reducing temperature variations and improving food freshness.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If the compressor and fan are driven when the temperature reaches the upper limit and stopped when the temperature reaches the lower limit, then the temperature control cycle maintains basic cooling function, but the storage compartment experiences great temperature variation width which lowers food freshness
Solution Approach 1:
The patent applies dynamics by making the cooling control system adjustable and adaptive rather than fixed. The control unit dynamically adjusts the reference temperature and temperature differential based on user selections from multiple modes (first mode with higher reference temperature and larger differential, second mode with lower reference temperature and smaller differential). This dynamic adjustment allows the system to adapt to different storage requirements and reduce temperature variation width, thereby improving food freshness while maintaining reliable temperature control.
2Ease of operation
If the temperature sensor is installed in a place less sensitive to cooling air influence, then the sensor installation is easier and more stable, but it becomes difficult to precisely and constantly control the temperature even when the temperature range is changed
Solution Approach 1:
The patent applies feedback by implementing a control unit that continuously monitors the temperature sensor output and adjusts the cooling control accordingly. The control unit calculates the actual temperature based on the sensor reading and compares it with the reference temperature, then adjusts the compressor and fan operation to minimize the temperature difference. This feedback mechanism compensates for the sensor's insensitive location, maintaining precise temperature control despite the sensor being installed in a stable but less responsive position.
3Device complexity
If a temperature sensor with lower resolution is used, then the sensor cost is reduced and installation is simplified, but the ability to precisely control the temperature is compromised
Solution Approach 1:
The control unit continuously monitors the temperature sensor output and adjusts the cooling control based on the measured temperature and reference temperature comparison. This feedback loop compensates for the lower resolution of the sensor by making fine adjustments to maintain the desired temperature, effectively overcoming the limitation of reduced sensor precision.
Solution Approach 2:
The patent applies parameter changes by allowing the reference temperature and temperature differential to be adjusted based on different operating modes. The control unit can select from multiple reference temperatures and differentials, enabling the system to optimize temperature control for different storage conditions. This flexibility compensates for lower sensor resolution by adapting the control parameters to match the sensor's capabilities.
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 approach effectively maintains a consistent storage compartment temperature, enhances food freshness, and reduces temperature variation at the sensor installation point, even with lower resolution sensors, allowing for improved temperature control and extended storage periods.
Implementation Method 1
A refrigerator is a home appliance to store foods at a lower temperature and compartments of the refrigerator need to be constantly maintained at a lower temperature
Data Source
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AI summary
A method of controlling a refrigerator includes: controlling a cooling unit such that an output of the cooling unit becomes a first reference output for a first reference time previously determined; controlling the cooling unit such that the output of the cooling unit becomes a second reference output for a second reference time previously determined; calculating a representative value of a temperature of a storage compartment for an operating period, which is made by a sum of the first reference time and the second reference time, and comparing the calculated representative value with a specific temperature in a temperature satisfying range of the storage compartment; and varying, by a control unit, at least one of the first reference time and the second reference time depending on a comparison result between the specific temperature and the representative value and controlling operating of the cooling unit based on a varied reference time.