Refrigeration apparatus
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Solution Overview
Problem
In refrigeration apparatuses, the lubrication of compressors can be inadequate during startup due to insufficient liquid refrigerant in the bypass flow passage, potentially causing damage, especially after a standby period or first start-up.
Innovation Solution
A refrigeration apparatus with a lubrication refrigerant line and storing cavities within the compressor, equipped with cooling devices like thermoelectric coolers to ensure the refrigerant is in a liquid state for lubrication, preventing damage during startup.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the refrigeration apparatus uses a bypass flow passage to supply liquid refrigerant to the compressor for lubrication, then the compressor can be lubricated during operation, but after a standby period the liquid refrigerant may migrate away or be insufficient in quantity to properly lubricate the compressor at first start or restart
Solution Approach 1:
The patent applies preliminary action by storing liquid refrigerant in advance within the compressor's rotor cavity and bearing chambers before startup. The refrigerant is pre-positioned in these cavities during the standby period, ensuring immediate availability for lubrication when the compressor starts, eliminating the delay and uncertainty of relying on bypass passage delivery alone.
Solution Approach 2:
The patent introduces an intermediary mechanism by using the compressor's own internal cavities (rotor cavity and bearing chambers) as intermediate storage locations for the lubricating refrigerant. These cavities act as mediators between the bypass passage and the actual lubrication points, ensuring the refrigerant is delivered reliably to where it is needed most.
2Device complexity
If the refrigeration apparatus operates without dedicated lubrication oil and uses refrigerant for both cooling and lubrication, then the system is simplified, but insufficient liquid refrigerant at compressor startup can cause potential damages
Solution Approach 1:
The patent applies universality by using the refrigerant to perform multiple functions: it serves as both the cooling medium in the refrigeration cycle and the lubricant for the compressor. This multi-functional approach eliminates the need for separate lubrication oil systems, simplifying the overall device while the internal cavity storage ensures adequate lubrication is available at startup.
Solution Approach 2:
The patent applies preliminary action by pre-storing liquid refrigerant in the rotor cavity and bearing chambers before startup. This ensures that when the compressor starts, sufficient lubricating refrigerant is already in place, preventing damage from inadequate lubrication during the critical startup period.
3Stability of the object's composition
If liquid refrigerant is allowed to migrate by gravity to low parts of the refrigerant circuit during standby, then the refrigerant distributes itself naturally, but the lubrication line becomes depleted of sufficient liquid refrigerant for proper compressor lubrication
Solution Approach 1:
The patent applies preliminary action by storing liquid refrigerant in advance within the compressor's rotor cavity and bearing chambers before startup. The refrigerant is pre-positioned in these cavities during the standby period, ensuring immediate availability for lubrication when the compressor starts, eliminating the delay and uncertainty of relying on bypass passage delivery alone.
Solution Approach 2:
The patent introduces an intermediary mechanism by using the compressor's own internal cavities (rotor cavity and bearing chambers) as intermediate storage locations for the lubricating refrigerant. These cavities act as mediators between the bypass passage and the actual lubrication points, ensuring the refrigerant is delivered reliably to where it is needed most.
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
Guarantees sufficient lubrication of the compressor during start-up, avoiding potential damage by maintaining a minimal quantity of liquid refrigerant in the cavities, thus ensuring proper operation and extending the compressor's lifespan.
Implementation Method 1
The at least one cooling device comprises at least one thermoelectric cooler
Data Source
AI summary
A refrigeration apparatus (1) includes a main refrigerant circuit (2) including a positive displacement compressor (4), a condenser (6), an expansion valve (8), and an evaporator (10), through which a refrigerant circulates successively in a closed loop circulation, a lubrication refrigerant line (18) connected to the main refrigerant circuit (2) between the condenser (6) and the expansion valve (8) or to the condenser (6), in which circulates a portion of the refrigerant of the main refrigerant circuit (2) and connected to the compressor (4) for lubrication of said compressor (4) with the refrigerant, at least one lubrication refrigerant storing cavity (70) connected to the lubrication refrigerant line (18), the lubrication refrigerant storing cavity (70) being configured to store liquid refrigerant for lubrication of the compressor (4) said at least one lubrication refrigerant storing cavity (70) being provided within the compressor (4).