Refrigeration system
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Solution Overview
Problem
Refrigeration systems face inefficiencies due to fixed intermediate pressure settings, which do not account for varying load states and climatic conditions, leading to suboptimal energy usage and refrigeration capacity.
Innovation Solution
A refrigeration system that regulates intermediate pressure dynamically based on setpoints, using a controller to adjust pressure within a defined range, optimizing efficiency by varying intermediate pressure in response to reference variables, and switching between parallel compression and flash gas/bypass operations to maintain optimal compressor operation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If fixed intermediate pressure settings are used, then the system structure is simple, but the energy efficiency decreases under varying load states and climatic conditions
Solution Approach 1:
The patent implements dynamic intermediate pressure regulation by allowing the intermediate pressure to vary within a defined range (between minimum and maximum intermediate pressures) based on operating conditions such as load state and climatic conditions, rather than maintaining a fixed pressure setting. This dynamic adaptation optimizes energy efficiency across different operating scenarios.
Solution Approach 2:
The system changes the intermediate pressure parameter dynamically within a specified range based on reference variables indicating operating conditions. The controller adjusts the intermediate pressure setpoint according to the magnitude of reference variables, enabling optimal energy efficiency under varying load states and climatic conditions while maintaining system simplicity.
2Use of energy by moving object
If intermediate pressure is varied to optimize efficiency, then energy usage improves, but control complexity increases
Solution Approach 1:
The controller receives reference variables indicating operating conditions and uses feedback mechanisms to determine the appropriate intermediate pressure setpoint. The system continuously monitors operating conditions and adjusts the intermediate pressure within the defined range to maintain optimal energy efficiency, with the controller managing the regulation based on feedback from sensors and reference variables.
3Productivity
If intermediate pressure is reduced to increase refrigeration capacity, then cooling performance improves, but compressor wear increases
Solution Approach 1:
The system dynamically adjusts the intermediate pressure within a defined range rather than continuously reducing it, allowing the refrigerator to achieve high refrigeration capacity when needed while avoiding excessive pressure reductions that would cause compressor wear. The minimum intermediate pressure acts as a protective lower limit.
Solution Approach 2:
The system establishes a minimum intermediate pressure limit beforehand to prevent the intermediate pressure from being reduced to values that would cause excessive compressor wear. This pre-defined boundary protects the compressor while still allowing sufficient pressure variation to achieve the desired refrigeration capacity.
4Use of energy by moving object
If intermediate pressure setpoints are unrestricted, then efficiency optimization is maximized, but system stability deteriorates
Solution Approach 1:
The system implements dynamic intermediate pressure regulation within a constrained range defined by minimum and maximum intermediate pressures. This bounded dynamic regulation allows efficiency optimization through pressure variation while maintaining system stability by preventing extreme pressure values that could disrupt other control and regulation processes.
Solution Approach 2:
The controller adjusts the intermediate pressure parameter within a defined range based on reference variables, enabling efficiency optimization through parameter variation while maintaining system stability by constraining the parameter changes within acceptable boundaries that do not significantly affect other control processes.
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 solution enhances the overall efficiency of the refrigeration system by optimizing energy usage across different load states and climatic conditions, ensuring maximum refrigeration capacity while minimizing wear on the compressor.
Implementation Method 1
a heat exchanger arranged in the refrigerant circuit and cooling the refrigerant on the high-pressure side
Implementation Method 2
an expansion element arranged in the refrigerant circuit, which in the active state cools the total mass flow of the refrigerant by expansion
Implementation Method 3
a refrigeration compressing the normal refrigeration mass flow from low pressure to high pressure
Data Source
Figure 1
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AI summary
Disclosed is a refrigeration system comprising a refrigerant circuit, a heat exchanger, an expansion member which, in the active state, cools the entire mass flow of the refrigerant by expanding same, in said process generating a main mass flow of liquid refrigerant and an additional mass flow of gaseous refrigerant which enter an intermediate pressure accumulator, the refrigeration system further comprising at least one normal cooling stage which expands a normal cooling mass flow to a low pressure in at least one normal cooling expansion unit, in said process making available refrigerating power for normal cooling, the refrigeration system also comprising a refrigerant compressor unit that compresses the normal cooling mass flow from the low pressure to a high pressure, and a parallel compressor which, in a parallel compression mode of the refrigerant circuit, sucks in refrigerant from the intermediate pressure accumulator and compresses same to a high pressure. In order to increase the efficiency of a refrigeration system of this type, the power of the parallel compressor is controlled by a controller, the controller determines at least one reference variable representing a load condition of the refrigerant circuit, the controller determines a desired intermediate pressure value on the basis of the at least one reference variable at least in a parallel compression mode, and the controller adjusts the intermediate pressure in accordance with the desired intermediate pressure value at least in the parallel compression mode.