Refrigeration apparatus, environment forming apparatus, and refrigeration method
Solution Overview
Problem
Existing refrigeration apparatuses with supercoolers achieve energy savings but require further improvements in efficiency.
Innovation Solution
A refrigeration apparatus comprising a main refrigeration circuit and a supercooling refrigeration circuit connected by a supercooling heat exchanger, with a controller that adjusts the superheating degree of the second refrigerant based on the refrigeration request degree to optimize energy usage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the supercooling refrigeration circuit operates continuously to maintain supercooling, then the refrigeration capacity is maintained, but the energy consumption increases
Solution Approach 1:
The supercooling refrigeration circuit operates intermittently rather than continuously. The control unit stops the second compressor when the refrigerant temperature in the supercooling heat exchanger reaches or below the target temperature, and restarts it when the temperature rises above the target. This periodic operation maintains refrigeration capacity while reducing energy consumption during periods when supercooling is already sufficient.
Solution Approach 2:
The control unit monitors the refrigerant temperature in the supercooling heat exchanger and uses this feedback to control the operation of the second compressor. When the temperature reaches the target value (indicating sufficient supercooling), the compressor is stopped. When the temperature rises above the target, the compressor is restarted. This feedback mechanism ensures energy-efficient operation while maintaining required refrigeration capacity.
2Use of energy by moving object
If a smaller compressor is used in the supercooling refrigeration circuit, then energy saving is achieved, but the refrigeration capacity may be insufficient
Solution Approach 1:
The system uses a smaller second compressor in the supercooling circuit, but compensates for its limited capacity by dynamically controlling its operation. The compressor runs only when needed (when refrigerant temperature exceeds the target), and stops when supercooling is sufficient. This dynamic control allows a smaller compressor to maintain adequate refrigeration capacity while achieving energy savings compared to continuously operating a larger compressor.
Solution Approach 2:
The supercooling refrigeration circuit pre-cools the refrigerant before it enters the evaporator, creating a reservoir of cold energy. This preliminary action allows the smaller second compressor to stop operating temporarily, as the pre-cooled refrigerant continues to provide cooling capacity during the off-period, maintaining overall refrigeration capacity with reduced energy consumption.
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
The solution enhances energy savings by optimizing the superheating degree of the second refrigerant, reducing the power consumption of the supercooling refrigeration circuit, especially when the refrigeration request degree is relatively small.
Implementation Method 1
The supercooling heat exchanger is configured to supercool the first refrigerant in the main refrigeration circuit by evaporation of the second refrigerant in the supercooling refrigeration circuit
Implementation Method 2
The supercooling heat exchanger is configured to exchange heat between the refrigerant in the supercooling refrigeration circuit and the refrigerant in the main refrigeration circuit
Data Source
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AI summary
A refrigeration apparatus includes a main refrigeration circuit in which a first refrigerant is sealed, a supercooling refrigeration circuit in which a second refrigerant is sealed and connected to a supercooling heat exchanger, and a controller. The supercooling heat exchanger supercools the first refrigerant in the main refrigeration circuit. In superheating degree setting control, the controller sets a target value of a degree of superheat of the second refrigerant on an outlet side of the supercooling heat exchanger to a first value when a refrigeration request degree is a first request value, and sets the target value of the degree of superheat to a second value larger than the first value when the refrigeration request degree is a second request value lower than the first request value. In superheating degree control, the controller controls a second expansion mechanism based on the target value of the degree of superheat.