Method for controlling a refrigerating appliance
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Solution Overview
Problem
Refrigerating appliances face inefficiencies in energy consumption and noise reduction, particularly in heavy operating conditions, and struggle with optimal temperature control and defrosting cycles, leading to reduced thermal exchange efficiency and potential food preservation issues.
Innovation Solution
A method for controlling refrigerating appliances with a variable-speed compressor that calculates compressor requests based on evaporator and compartment temperatures, optimizes fan speed for silence, and dynamically adjusts defrosting cycles based on actual compartment and evaporator temperatures to ensure energy efficiency and proper preservation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If the compressor increases its on-time percentage and speed in heavy operating conditions, then the refrigerating capacity is sufficient, but the energy consumption increases and noise increases
Solution Approach 1:
The patent applies dynamics by implementing a variable-speed compressor that can continuously adjust its rotation speed based on real-time thermal exchange efficiency monitoring. Instead of operating at fixed high speed during heavy conditions, the compressor dynamically modulates its speed to match actual cooling demands, reducing energy consumption while maintaining sufficient refrigerating capacity.
Solution Approach 2:
The patent implements feedback control by continuously monitoring the thermal exchange efficiency of the evaporator and using this information to adjust compressor operation. The system measures temperature differences and heat transfer coefficients, then feeds this data back to the control unit, which optimizes compressor speed and defrost timing to minimize energy consumption while maintaining required cooling performance.
2Power
If the compressor increases its on-time percentage and speed in heavy operating conditions, then the refrigerating capacity is sufficient, but the noise increases
Solution Approach 1:
The patent applies dynamics by implementing a variable-speed compressor that can continuously adjust its rotation speed based on real-time thermal exchange efficiency monitoring. Instead of operating at fixed high speed during heavy conditions, the compressor dynamically modulates its speed to match actual cooling demands, reducing noise while maintaining sufficient refrigerating capacity.
3Reliability
If defrosting cycles are executed to remove frost from the evaporator, then the thermal exchange efficiency is restored, but the compressor must be turned off and energy is consumed by heating means
Solution Approach 1:
The patent implements feedback control by continuously monitoring the thermal exchange efficiency of the evaporator through temperature measurements. When efficiency degradation due to frosting is detected, the system triggers defrosting cycles. The control unit analyzes real-time data to determine optimal defrost timing, triggering defrost only when necessary to restore thermal exchange efficiency, thereby minimizing energy consumption from heating means.
Solution Approach 2:
The patent applies self-service by using the evaporator's own operating conditions to trigger its own defrosting cycle. The system monitors the evaporator's thermal exchange efficiency and automatically initiates defrosting when frosting is detected, without requiring external intervention or fixed scheduling, thus optimizing energy usage based on actual needs.
4Productivity
If the evaporator operates in forced convection in no-frost appliances, then the cooling distribution is improved, but the evaporator is subject to greater load loss increase and icing
Solution Approach 1:
The patent implements feedback control by continuously monitoring the thermal exchange efficiency of the evaporator in no-frost appliances. The control unit measures temperature differences across the evaporator and detects when forced convection causes excessive icing or load loss. When degradation is detected, the system triggers defrosting cycles or adjusts operating parameters to restore efficiency, maintaining the benefits of forced convection while mitigating its adverse effects.
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 optimizes energy consumption, reduces noise, and ensures reliable temperature control and preservation by prioritizing evaporator and compartment needs, enhancing overall operational efficiency and food preservation.
Implementation Method 1
the fluid in the liquid state is caused to expand and evaporate in an evaporator and, when brought into direct thermal contact with the refrigerated compartment, it subtracts heat from the latter
Implementation Method 2
a compressor compresses a cycle fluid, also called refrigerating fluid (e.g. Freon or ammonia), in order to cause the fluid to change from the gaseous state to the liquid state. This first change of state produces heat, which is extracted from the cycle through a coil in direct contact with the environment outside the refrigerating appliance
Implementation Method 3
the control system turns on heating means for thawing the frost, thus removing it from the evaporator
Data Source
Figure 1
Figure 2
Figure 3~4
AI summary
A method for controlling a refrigerating appliance is described, said refrigerating appliance comprising a refrigerating circuit which includes an evaporator (EV) and a variable - speed compressor (CPS), and at least one compartment (FG, FZ) which is cooled by said refrigerating circuit, said method comprising the steps of: - calculating, for said evaporator (EV), a first compressor request function (CPSreqEV) which depends on the evaporator temperature; - calculating, for said at least one compartment (FG, FZ), a second compressor request function (CPSreqF) which depends on the compartment temperature; - calculating a total compressor request function (CPSreqTOT) which, if said first function is different from zero, is given by an operation of selecting between said first and second compressor request functions, or else, if said first function is null, is given by said second compressor request function multiplied by a reduction factor (SF); - controlling said compressor through said total compressor request function.