Refrigerator Compressor Startup Frequency to Prevent Current Leakage
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Refrigeration devices experience electric current leakage during initial operation after installation due to liquefied refrigerant, leading to breaker tripping and the need for separate preheating devices like crankcase heaters.
Innovation Solution
A compressor operating method that initially operates at a lower carrier frequency than normal, with a determination step to identify first-time operations and adjust frequency accordingly, eliminating the need for separate preheating devices by performing preheating or preliminary operations at reduced frequencies before switching to normal operation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the compressor is operated at a regular carrier frequency immediately after installation, then normal cooling performance is achieved, but electric current leakage occurs due to liquefied refrigerant causing breaker tripping
Solution Approach 1:
The patent applies preliminary action by detecting the presence of liquid refrigerant in the compressor before normal operation begins. When liquid refrigerant is detected, the system performs a preliminary preheating operation at reduced carrier frequency to evaporate the liquid refrigerant and prevent breaker tripping during subsequent normal operation, thus ensuring reliable startup without compromising cooling performance
Solution Approach 2:
The patent changes the carrier frequency parameter dynamically based on operating conditions. During preheating operation to eliminate liquid refrigerant, the carrier frequency is reduced to a lower value than normal operation. This parameter change allows the compressor to safely evaporate liquid refrigerant without causing breaker tripping, while still achieving the necessary preheating effect
2Reliability
If a separate preheating device such as a crankcase heater is mounted to the compressor, then electric current leakage is prevented, but device complexity and cost increase
Solution Approach 1:
The patent makes the compressor motor perform multiple functions: it serves both as the main compression driver and as a preheating device during startup. By controlling the compressor to operate at reduced carrier frequency initially, the motor generates heat that evaporates liquid refrigerant without requiring a separate crankcase heater, thus eliminating additional components while maintaining reliability
Solution Approach 2:
The patent enables the compressor system to service itself by using the compressor motor's own operation to heat and evaporate liquid refrigerant during startup. The system detects liquid refrigerant presence and automatically initiates a preheating cycle where the compressor runs at reduced frequency to generate necessary heat, eliminating the need for external preheating devices
3Reliability
If warm air from outside is used to heat the compressor and discharge refrigerant, then electric current leakage is prevented, but installation complexity and time increase
Solution Approach 1:
The patent enables the compressor system to service itself by using the compressor motor's own operation to heat and evaporate liquid refrigerant during startup. The system detects liquid refrigerant presence and automatically initiates a preheating cycle where the compressor runs at reduced reduced frequency to generate necessary heat, eliminating the need for external preheating devices
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
Reduces electric current leakage during initial operations, prevents breaker tripping, and eliminates the necessity for separate preheating devices, ensuring smooth refrigerant circulation and efficient compressor performance.
Implementation Method 1
at a first-time operation of the compressor after the refrigeration device is installed, the compressor is operated at a carrier frequency that is lower than carrier frequency for a normal operation
Implementation Method 2
whether or not it is the first-time operation of the compressor is determined by checking a flag
Data Source
Figure 1
Figure 2
Figure 3
AI summary
A refrigeration device and a compressor operation method of the refrigeration device are provided in which occurrence of leakage of electric current due to a liquefied refrigerant at a first-time operation is reduced and a separate preheating device is unnecessary. With an operation method of a compressor (21) of a refrigeration device (1), at a first-time operation of the compressor (21) after the refrigeration device (1) is installed, the compressor is operated at a carrier frequency that is lower than a carrier frequency for a normal operation and thereafter the normal operation is performed at the carrier frequency for the normal operation.