Refrigeration cycle device
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Solution Overview
Problem
In refrigeration cycle apparatuses, the oil separator fails to completely separate refrigerant and refrigerating machine oil, leading to mixed flowouts, surplus oil circulation, increased compressor inputs, and decreased oil separation efficiency, resulting in refrigerating machine oil depletion within the compressor.
Innovation Solution
A refrigeration cycle apparatus with a distributor having specific oil return ports and flow paths, where the refrigerating machine oil preferentially flows to an oil tank via gravity separation, reducing compressor inputs and maintaining adequate oil levels within the compressor.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the oil separator is used to separate refrigerant and refrigerating machine oil, then oil separation is achieved, but the separation is incomplete and mixed flowout occurs
Solution Approach 1:
The return line is divided into two separate lines: a first return line that returns refrigerating machine oil directly from the oil separator to the compressor, and a second return line that returns refrigerant from the evaporator to the compressor. This segmentation allows selective control of oil return independent of refrigerant flow.
Solution Approach 2:
A solenoid valve is introduced to dynamically control the first return line, enabling selective opening and closing based on operational conditions. The valve opens during startup to ensure oil return and closes during normal operation to prevent surplus oil circulation, making the system adaptive to different operating states.
2Reliability
If surplus refrigerating machine oil circulates in the refrigeration cycle, then oil is always available, but compressor inputs increase
Solution Approach 1:
The solenoid valve provides dynamic control over oil return, opening during startup when oil is needed and closing during normal operation when surplus oil would increase compressor inputs. This temporal differentiation optimizes both lubrication reliability and energy efficiency.
Solution Approach 2:
The control unit monitors operational state and adjusts the solenoid valve accordingly, creating a feedback loop that prevents surplus oil circulation during conditions where it would increase compressor inputs, while ensuring oil availability when needed.
3Quantity of substance
If the oil separator processes all discharged oil, then separation capacity is maximized, but separation capability is surpassed and efficiency decreases
Solution Approach 1:
By segmenting the return path into two lines with independent control, the system can bypass the oil separator for refrigerant return while maintaining dedicated oil return capability, preventing overload of the separation function.
Solution Approach 2:
The first return line provides an additional oil return path that activates when needed (startup conditions), supplementing the normal oil separation capacity without requiring the oil separator to handle excessive oil volumes during all operating conditions.
4Device complexity
If a single return line is used, then device complexity is reduced, but reliable oil supply cannot be ensured under all conditions
Solution Approach 1:
The return system is segmented into two functionally distinct lines with independent control, allowing the first return line to provide guaranteed oil supply during startup while the second line handles normal refrigerant return, ensuring reliability without excessive complexity.
Solution Approach 2:
The solenoid valve acts as an intermediary that selectively activates the first return line based on operational conditions, providing reliable oil supply control without requiring complex mechanical arrangements or multiple always-active pathways.
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 configuration prevents surplus refrigerating machine oil accumulation in the compressor, enhances oil separation efficiency, and ensures reliable refrigerating machine oil supply, reducing compressor inputs and maintaining optimal lubrication.
Implementation Method 1
the refrigerating machine oil preferentially flows to an oil tank via gravity separation
Data Source
Figure 1
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Figure 4
AI summary
A refrigeration cycle apparatus includes connected in series a compressor, an oil separator, a condenser, an expansion valve, and an evaporator, and comprising: a distributor communicating to the oil separator and configured to branch a flow of refrigerating machine oil separated within the oil separator; a first oil return flow path to cause the flow of the refrigerating machine oil branched by the distributor to flow into a suction side of the compressor, the first oil return flow path including an expansion valve; and a second oil return flow path to cause the flow of the refrigerating machine oil branched by the distributor to flow into the suction side of the compressor, the second oil return flow path including an oil tank accumulating refrigerating machine oil and a valve provided between the oil tank and the suction side of the compressor, the distributor having a distributor main body in which an inflow opening port communicating to the oil separator, a first oil return opening port communicating to the first oil return flow path, and a second oil return opening port communicating to the second oil return flow path are formed, the first oil return opening port provided at an upper portion of the distributor main body, the second oil return opening port being provided at a lower portion of the distributor main body.