Refrigerator Compressor Control With Temperature-Dependent Off-Time
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Solution Overview
Problem
Existing refrigeration control methods require predetermined switch-on and switch-off times for the compressor, leading to uneven cooling cycles and reduced efficiency when ambient conditions deviate from anticipated values, necessitating lengthy test series for adjustment.
Innovation Solution
A dynamic temperature-dependent control method that adapts switch-off times based on constant conditions, such as stable ambient and compartment temperatures, eliminating the need for lengthy test series and optimizing control behavior for varying conditions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If predetermined switch-on and switch-off times are used for the compressor, then the control method is simple to implement, but the temperature control becomes uneven and efficiency decreases when ambient conditions deviate from anticipated values
Solution Approach 1:
The patent applies dynamics by transitioning from fixed predetermined switch-on and switch-off times to dynamic time values that are calculated based on actual ambient temperature and compartment temperature. The switch-on time and switch-off time are continuously adapted according to the temperature difference and ambient conditions, allowing the control system to respond flexibly to changing environmental conditions while maintaining reliable temperature control.
2Device complexity
If predetermined switch-on and switch-off times are used, then the control logic is straightforward, but lengthy test series are required to determine optimal timing parameters
Solution Approach 1:
The patent implements self-service by enabling the control system to automatically determine optimal switch-on and switch-off times through real-time temperature monitoring and calculation. The system uses the measured ambient temperature and compartment temperature to compute appropriate time values without requiring external testing or manual adjustment, thereby eliminating lengthy test series while maintaining straightforward control logic.
Solution Approach 2:
The patent applies feedback by continuously monitoring the compartment temperature and ambient temperature, then using this feedback information to adjust the switch-on and switch-off times. The control system incorporates the temperature difference and ambient conditions into the timing calculation, creating a closed-loop system that automatically optimizes compressor operation without requiring external testing.
3Device complexity
If fixed time-controlled compressor operation is implemented, then the control system is easy to program, but the temperature often exceeds maximum or falls below minimum temperature
Solution Approach 1:
The patent applies parameter changes by modifying the switch-on and switch-off time parameters based on ambient temperature and temperature difference. Instead of using fixed time values, the system calculates dynamic time parameters that adapt to changing conditions, thereby maintaining temperature precision within the desired range while keeping the programming approach relatively simple through standardized calculation formulas.
Data Source
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AI summary
According to the invention, the method for controlling a refrigerator (10) comprises the following steps: a. determining the temperature (T) present in a refrigeration space (14); b. comparing the temperature (T) to a maximum temperature (Tmax); c. comparing the temperature (T) to a minimum temperature (Tmin); d. activating a compressor (22) of a refrigeration cycle (20) of the refrigerator (10) when the temperature (T) exceeds the maximum temperature (Tmax); e. deactivating the compressor (22) when the temperature (T) drops below the minimum temperature (Tmin); f. alternately activating the compressor (22) during an activation period (tein) and deactivating the compressor (22) during a deactivation period (taus) when the temperature (T) is below the maximum temperature (Tmax) and above the minimum temperature (Tmin); g. controlling the deactivation period (taus) depending on the temperature (T).