Refrigerator Compressor RPM Control Based on Operation Rate Feedback
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Solution Overview
Problem
The existing refrigerator control systems require a main microcomputer to manage compressor operations, increasing costs and complexity, while existing frequency control methods are inefficient in adjusting compressor speed based on actual operation rates.
Innovation Solution
A control method utilizing a compressor microcomputer to adjust the compressor's RPM based on previous operation cycles, increasing RPM when the operation rate exceeds a certain threshold and reducing it when below another threshold, allowing efficient temperature control without a main microcomputer.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a main microcomputer is installed to control compressor operations, then temperature control capability is improved, but manufacturing cost and device complexity increase
Solution Approach 1:
The patent extracts the temperature control function from the main microcomputer and implements it directly in the compressor control microcomputer. The compressor control microcomputer independently calculates the operation rate based on compressor operation time and cycle time, determines appropriate RPM adjustments, and controls compressor speed without requiring a separate main microcomputer, thereby reducing device complexity while maintaining temperature control capability
Solution Approach 2:
The compressor control microcomputer is designed to perform multiple functions: it controls compressor operation, calculates operation rate, determines RPM adjustments, and manages temperature control. This multi-functional design eliminates the need for a separate main microcomputer, reducing both device complexity and manufacturing cost while preserving full temperature control capability
2Use of energy by moving object
If compressor RPM is frequently adjusted based on operation rate, then energy efficiency is improved, but control algorithm complexity increases
Solution Approach 1:
The patent changes the control parameter from complex real-time temperature-based adjustment to a simpler operation-rate-based adjustment. The compressor control microcomputer calculates the operation rate (compressor operation time divided by cycle time) and adjusts RPM based on predefined thresholds, significantly simplifying the control algorithm while maintaining energy efficiency through adaptive speed control
3Adaptability or versatility
If variable frequency control is implemented, then refrigeration capacity adaptability is improved, but device complexity and manufacturing cost increase
Solution Approach 1:
The compressor control microcomputer autonomously monitors its own operation, calculates the operation rate based on its operation time and cycle time, and automatically adjusts its RPM accordingly. This self-service capability provides refrigeration capacity adaptability without requiring external control systems, reducing device complexity and manufacturing cost while maintaining the ability to adapt to different refrigeration demands
Data Source
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AI summary
A control method includes initially operating a compressor at the same RPM as an operating RPM of the compressor during a previous cycle, adjusting the RPM in consideration of an operation rate of the previous cycle such that the RPM is increased when the operation rate is greater than a first set value, reduced when the operation rate is less than a second set value, and maintained when the operation rate is within a range between the first set value and the second set value, and operating the compressor at the adjusted RPM, the first set value being greater than the second set value.