Refrigeration cycle apparatus
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Solution Overview
Problem
Conventional air-conditioning apparatuses using propane as refrigerant face a trade-off between reducing refrigerant amount to prevent combustibility and maintaining coefficient of performance (COP), as decreasing refrigerant amount degrades COP.
Innovation Solution
The refrigeration cycle apparatus controls the degree of suction superheat of the compressor to reduce the required refrigerant amount while using R290 refrigerant, which has a higher evaporation latent heat, thereby maintaining COP by optimizing the refrigerant circuit design and valve operations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the amount of refrigerant is reduced to prevent combustibility, then safety is improved, but the coefficient of performance degrades
Solution Approach 1:
The invention changes the physical parameters of the refrigerant system by using R290 refrigerant with higher evaporation latent heat and adjusting the degree of suction superheat to 10K or more. This parameter change allows the system to maintain COP while using less refrigerant, thus resolving the contradiction between safety and energy efficiency
Solution Approach 2:
The invention dynamically adjusts the degree of suction superheat as a control parameter to optimize system performance. By making the superheat degree adjustable and controllable, the system can adapt to different operating conditions while maintaining both safety and COP performance
2Object-affected harmful factors
If the amount of refrigerant is reduced, then the combustible concentration risk is reduced, but the cooling capacity decreases
Solution Approach 1:
By changing to R290 refrigerant with higher evaporation latent heat and adjusting the suction superheat degree, the invention achieves the same cooling capacity with reduced refrigerant amount, thus lowering combustible concentration risk while maintaining productivity
Solution Approach 2:
The invention uses the favorable thermodynamic properties of R290 refrigerant to copy and replace the performance characteristics of conventional refrigerants, achieving equivalent or superior cooling capacity with smaller refrigerant charge
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 approach allows for a reduction in refrigerant amount while preventing degradation of the coefficient of performance, ensuring safety and efficiency by adjusting the suction superheat and using R290 refrigerant properties.
Implementation Method 1
using R290 refrigerant, which has a higher evaporation latent heat
Implementation Method 2
an evaporator that causes the refrigerant to evaporate
Implementation Method 3
a compressor that compresses the refrigerant
Implementation Method 4
a condenser that causes the refrigerant to condense
Implementation Method 5
a pressure-reducing device that reduces the pressure of the refrigerant
Data Source
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AI summary
A refrigeration cycle apparatus includes a refrigerant circuit and a controller for controlling the refrigerant circuit. The refrigerant circuit includes a compressor, a condenser, a pressure-reducing device and an evaporator. Refrigerant circulating through the refrigerant circuit contains propane or propylene. The controller sets a degree of superheat of refrigerant at an entrance port of the compressor to be a value greater than or equal to 10 degrees.