Refrigeration device
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Solution Overview
Problem
Conventional refrigeration apparatuses face challenges in rapidly returning the internal temperature of a storage space to a target value when the temperature rises, leading to inefficiencies and energy waste due to heat transmission delays and unnecessary compressor speed fluctuations.
Innovation Solution
A refrigeration apparatus with a cascade cycle system, comprising a first and second cooling section, a storage section, and a control system that adjusts the rotation speeds of compressors based on detected temperatures to rapidly stabilize the storage space temperature, utilizing a predetermined correspondence relation between the rotation speeds of the first and second compressors to optimize cooling efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If the compressor speed is increased to rapidly lower the storage space temperature, then the temperature recovery speed is improved, but energy consumption increases
Solution Approach 1:
The patent applies dynamics by making the compressor speed variable rather than fixed. The control section dynamically adjusts the rotation speeds of both compressors based on real-time temperature feedback from the storage space, allowing the system to operate at optimal speeds under different conditions rather than always at maximum capacity.
Solution Approach 2:
The patent implements feedback control where the control section continuously monitors the storage space temperature and uses this information to adjust compressor speeds. The temperature detection result feeds back to the control section, which then determines appropriate rotation speeds for both compressors to achieve rapid temperature recovery while minimizing energy consumption.
2Power
If the compressor operates at high speed continuously, then the cooling capacity is improved, but heat transmission delays increase
Solution Approach 1:
The patent applies preliminary action by having the first compressor (high-temperature side) start operating before the second compressor (low-temperature side). This pre-cooling of the cascade condenser prepares the heat transmission path in advance, reducing the thermal inertia and delay when the second compressor starts, thereby improving overall response time.
Solution Approach 2:
The system dynamically coordinates the operation of two compressors with different temperatures, allowing the first compressor to operate independently initially to prepare the heat transmission path, then coordinating with the second compressor for optimal cooling capacity while minimizing thermal delays.
3Measurement precision
If the compressor speed is frequently adjusted, then the temperature control precision is improved, but system stability deteriorates
Solution Approach 1:
The patent applies dynamics by implementing coordinated dynamic control of two compressors with a predetermined correspondence relation between their rotation speeds. This coordinated adjustment maintains system stability while allowing precise temperature control, as the compressors work together rather than independently fluctuating.
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 system effectively and efficiently returns the storage space temperature to the target value quickly, reducing energy waste by minimizing compressor speed fluctuations and heat transmission delays, thus enhancing the refrigeration apparatus's performance.
Implementation Method 1
a first evaporator that evaporates low-temperature and low-pressure first refrigerant discharged from a first expander, and a first rear stage condenser that constitutes a cascade condenser in cooperation with the first evaporator
Implementation Method 2
a second evaporator that evaporates low-temperature and low-pressure second refrigerant discharged from a second expander, and a storage space for a cooling target cooled by the second evaporator
Data Source
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AI summary
A refrigeration device equipped with: a cascade cycle; a storage unit having a storage space for an object to be cooled by a second evaporator; an internal temperature sensor that detects the temperature of the storage space; a control unit that determines a second rotational speed of a second compressor on the basis of a target temperature for the storage space and the detection result from the internal temperature sensor, and that determines a first rotational speed for a first compressor having a prescribed correspondence relationship with the second rotational speed; and a first power supply unit and a second power supply unit that supply power respectively to the first compressor and the second compressor on the basis of the first rotational speed and the second rotational speed determined by the control unit.