Single-circuit refrigeration device
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Solution Overview
Problem
Conventional refrigeration devices with a single evaporator struggle to maintain optimal cooling in both compartments across varying ambient temperatures, leading to inefficient energy use and potential spoilage of chilled goods, as they require precise matching of parameters and often rely on inefficient heating mechanisms like the winter circuit to ensure adequate cooling.
Innovation Solution
A refrigeration device with a compressor throughput that adjusts based on ambient temperature, using a control system that switches the compressor on and off in response to temperature sensors, increasing throughput at low ambient temperatures to maintain sufficient cooling without unnecessary energy consumption, and potentially using a single temperature sensor or a timer to control compressor operation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the compressor throughput is increased to ensure sufficient cooling of the cold storage compartment at low ambient temperatures, then the cooling reliability is improved, but the energy consumption increases
Solution Approach 1:
The patent applies dynamics by making the compressor throughput variable rather than fixed. The control system dynamically adjusts the compressor throughput based on ambient temperature conditions, increasing it when ambient temperature is low to ensure sufficient cooling of the cold storage compartment, and reducing it when ambient temperature is high to save energy. This dynamic adjustment resolves the contradiction between maintaining reliable cooling and minimizing energy consumption.
Solution Approach 2:
The patent changes the operating parameters of the compressor based on ambient temperature. By monitoring ambient temperature and adjusting the compressor throughput accordingly, the system optimizes the balance between cooling reliability and energy efficiency. The control system modifies key parameters such as compressor speed and refrigerant mass flow to adapt to varying environmental conditions.
2Device complexity
If a single temperature sensor in the warm storage compartment is used to control compressor operation, then the device complexity is reduced, but the temperature control precision of the cold storage compartment deteriorates
Solution Approach 1:
The patent implements a feedback control system that uses temperature sensor data from the warm storage compartment to regulate compressor operation. The control system continuously monitors the temperature and adjusts the compressor throughput accordingly, ensuring that the cold storage compartment maintains its required temperature despite the single sensor configuration. This feedback mechanism compensates for the reduced sensor coverage and maintains temperature control precision.
Solution Approach 2:
The single temperature sensor in the warm storage compartment serves multiple functions: it controls compressor startup and shutdown, provides feedback for throughput adjustment, and indirectly monitors the thermal state of the entire refrigeration system. This multi-functional use of a single sensor reduces device complexity while maintaining adequate temperature control through the series-connected evaporator configuration.
3Device complexity
If the evaporators are connected in series to eliminate the directional control valve, then the device complexity and manufacturing cost are reduced, but the adaptability to different ambient temperature conditions deteriorates
Solution Approach 1:
The patent introduces dynamic control of compressor throughput to compensate for the fixed series connection of evaporators. While the physical configuration remains simple and fixed (improving device complexity), the control system dynamically adjusts operating parameters to adapt to varying ambient temperature conditions. This dynamic control enables the simple series configuration to achieve adaptability that would otherwise require complex valve systems.
Solution Approach 2:
The patent changes the operating parameters of the refrigeration system based on ambient temperature. By adjusting compressor throughput, refrigerant mass flow, and evaporation temperatures, the system adapts to different ambient conditions despite the fixed series evaporator configuration. This parameter-based adaptation eliminates the need for directional control valves while maintaining versatility across different operating conditions.
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 ensures consistent cooling of the cold storage compartment while reducing energy usage by matching compressor throughput to ambient temperature needs, avoiding the inefficiencies of continuous operation and additional heating, thus maintaining food freshness and reducing energy costs.
Implementation Method 1
a compressor (8) which is connected to at least two evaporators (6, 7), which are each assigned to storage compartments (1, 2) with different temperatures
Implementation Method 2
the evaporators (6, 7) are part of a refrigerant circuit of the refrigerator
Implementation Method 3
the two evaporators are connected in series, so that the refrigerant coming from the compressor first runs through the first evaporator and then through the second evaporator
Implementation Method 4
a condenser (9), a throttle point (10) and possibly a shut-off valve (11), are part of a refrigerant circuit
Implementation Method 5
a throttle point (10) and possibly a shut-off valve (11), are part of a refrigerant circuit
Data Source
Figure 1~2
Figure 3~4
Figure 5~6
AI summary
For a refrigeration device, in particular a domestic refrigeration device, having a refrigerant circuit in which a compressor (8) is connected to at least one first evaporator (6), which is associated with a cold storage compartment (2), and to a second evaporator (7), which is associated with a warm storage compartment (1), the compressor (8) can be operated with a variable flow rate and is designed to be operated at low ambient temperature with a flow rate that is temporarily higher than the flow rate at high ambient temperature.