Expander-integrated compressor, freezer, and freezer operation method
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Solution Overview
Problem
In expander-integrated compressors for refrigerators, leakage of compressed fluid from the compressor to the expander leads to reduced adiabatic efficiency due to heat transfer, which in turn decreases the coefficient of performance (COP).
Innovation Solution
An extraction line is introduced to redirect leakage fluid from the compressor to the intake or discharge side of the compressor, reducing heat transfer to the expander and improving sealing to prevent external gas ingress, thereby enhancing COP.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If seals are provided between the compressor and the region and between the expander and the region to prevent fluid leakage, then fluid sealing is improved, but it is still difficult to completely prevent leakage fluid from reaching the expander side via the region
Solution Approach 1:
The patent extracts the harmful leakage fluid from the region between the compressor and expander by providing an extraction line that actively removes the fluid before it can reach the expander. This separates the sealing function from the leakage management function, allowing seals to focus on prevention while the extraction line handles removal of any fluid that does leak.
Solution Approach 2:
The extraction line acts as an intermediary component between the region and the expander, intercepting the leakage fluid pathway. Instead of relying solely on seals to block the fluid, the extraction line provides an intermediate control point to manage the fluid flow and prevent it from affecting expander performance.
2Device complexity
If leakage fluid flows from the compressor side to the expander side through the region, then the structure is simple, but heat transfer from the high-temperature leakage fluid reduces the adiabatic efficiency of the expander
Solution Approach 1:
The patent converts the harmful hot leakage fluid into a beneficial resource by routing it through a heat exchanger. The heat exchanger recovers heat from the leakage fluid, converting what was previously a source of efficiency loss into a potential heat recovery opportunity that can improve overall system efficiency.
Solution Approach 2:
The extraction line removes the harmful thermal energy from the leakage fluid before it can transfer heat to the expander. By extracting the fluid through a controlled pathway with heat exchange capability, the system eliminates the direct heat transfer path that would otherwise reduce adiabatic efficiency.
3Ease of operation
If the region between the compressor and expander is not sealed from the outside, then access is easier, but external gas can ingress into the region and cause unintended heat input to the expander
Solution Approach 1:
The patent segments the internal space by creating a sealed region between the compressor and expander. This segmentation isolates the critical components from external environmental influences, preventing unwanted gas ingress and heat transfer while maintaining controlled access points for maintenance without compromising the sealed environment.
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 effectively suppresses the reduction in adiabatic efficiency and significantly improves the COP of the refrigerator by minimizing heat input to the expander and optimizing the use of leakage fluid.
Implementation Method 1
a compressor employing a non-contact bearing such as a magnetic bearing as a bearing for the output shaft of the motor driving the compressor
Implementation Method 2
an expander connected to the output shaft of the motor and configured to expand the fluid to recover power for the output shaft from the fluid
Implementation Method 3
a compressor connected to an output shaft of the motor and configured to compress the fluid
Implementation Method 4
leakage of compressed fluid from the compressor to the expander leads to reduced adiabatic efficiency due to heat transfer
Data Source
Figure 1
Figure 2~3
Figure 4
AI summary
To reduce heat transfer from leakage fluid from a compressor side to an expander in a casing of an expander-integrated compressor to improve the coefficient of performance (COP) of a refrigerator, the expander-integrated compressor includes a motor, a compressor connected to an output shaft of the motor, an expander connected to the output shaft of the motor, a non-contact bearing disposed between the compressor and the expander, a casing, and an extraction line provided so as to be in communicated with a region between the compressor and the expander in the internal space of the casing and configured to extract, from the region, the leakage fluid from the compressor side toward the expander side in the casing and to send the leakage fluid to a fluid line connected to the intake side or the discharge side of the compressor outside the casing. The casing is configured to seal the region from outside of the casing so that the flow of the at least a part of the leakage fluid through the extraction line is the only flow of fluid between the region and the outside of the casing.