Single-Circuit Refrigerator Control for Fast Load Cooling
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional refrigeration appliances with evaporators connected in series face inefficiencies in cooling newly loaded refrigerated goods, as the control unit cannot prioritize cooling for unseen compartments, leading to prolonged cooling times and potential heating of existing goods, especially when freezing is required, which affects energy efficiency and shelf life.
Innovation Solution
A refrigeration system with a compressor connected to upstream and downstream evaporators, allowing for a mode switch to intensive cooling with phases of long and short compressor operation, directing more cooling capacity to the first compartment and optimizing refrigerant circulation to rapidly cool newly loaded goods while maintaining energy efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If the compressor operates continuously in super cooling mode to cool newly loaded refrigerated goods rapidly, then the cooling speed is improved, but the energy consumption increases and the second storage compartment is unnecessarily cooled
Solution Approach 1:
The control unit implements periodic action by alternating between long compressor operating times (for rapid cooling) and short operating times (for energy efficiency). During long operating times, the compressor runs continuously to provide high cooling capacity. During short operating times, the compressor runs only long enough to supply sufficient refrigerant to the first evaporator, reducing energy consumption while maintaining cooling effectiveness.
Solution Approach 2:
The system dynamically adjusts compressor operation based on real-time temperature measurements from both storage compartments. The control unit monitors temperatures and automatically switches between long and short operating time modes, optimizing the balance between cooling speed and energy consumption according to actual thermal conditions.
2Speed
If the compressor operates continuously to freeze chilled goods in the freezer compartment, then the freezing speed is improved, but the time required increases due to regular interruptions to avoid sub-cooling in the normal refrigeration compartment
Solution Approach 1:
The control unit uses feedback from temperature sensors in both storage compartments to determine when to interrupt or continue compressor operation. By continuously monitoring temperatures and comparing them against target values, the system intelligently decides when long operating times are needed for rapid freezing and when short operating times suffice, eliminating unnecessary interruptions while preventing harmful sub-cooling.
Solution Approach 2:
The system dynamically adapts compressor operation duration based on thermal conditions in both compartments. When the second compartment approaches dangerous low temperatures, the control unit switches to short operating times or interrupts compression. When cooling demand is high in the first compartment, the system extends operating times, optimizing the freezing process.
3Device complexity
If the control unit switches the compressor on and off based on temperature sensor readings from one storage compartment, then the control simplicity is maintained, but the cooling response for the unmonitored compartment is delayed
Solution Approach 1:
The control unit performs multiple functions: it monitors temperatures from both storage compartments, determines cooling demands for both compartments, and controls compressor operation to satisfy both compartments' needs simultaneously. This multi-functional approach maintains relatively simple control hardware while dramatically improving cooling response time for the previously unmonitored compartment.
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 enables rapid and energy-efficient cooling of newly loaded refrigerated goods by prioritizing cooling for the first compartment during intensive mode, reducing the time needed to cool new items while minimizing heating of the second compartment, thus improving the overall efficiency and shelf life of stored goods.
Implementation Method 1
a compressor (7)
Implementation Method 2
an upstream and a downstream evaporator (5, 6), which are connected in series to the compressor (7)
Data Source
Figure 1
Figure 2~3
AI summary
The invention concerns a refrigerator, in particular a domestic refrigerator, comprising a compressor (7), an upstream and a downstream evaporator (5, 6), which are connected in series to the compressor (7), a first storage compartment (2), which is cooled by means of the upstream evaporator (5), and a second storage compartment (3), which is cooled by the downstream evaporator (6). According to the invention, a control unit (11) is arranged, in a normal cooling mode (S1 - S5), to control the operation of the compressor (7) by comparing the temperature (Tnk) measured by a temperature sensor (13) in one of the storage compartments (3) with a first set value, and can be switched by a user from the normal cooling mode into an intensive cooling mode, which comprises at least one phase of long compressor-operating times ([t1, t2]; S6-S11), in which the control unit (11) controls the operation of the compressor (7) by comparing the measured temperature (Tnk) with a second set value which is lower than the first set value, and a phase of short compressor-operating times ([t2, t3]; S12-S17) in which the amount of coolant circulated by the compressor (7) between switching on and subsequent switching off is less than the capacity of the two compressors (5, 6) for liquid coolant.