Compressor Suction Nozzle Layout to Block Liquid Refrigerant Return
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Solution Overview
Problem
Hermetic refrigeration compressors in commercial applications, such as ice cube-making machines, face issues with liquid refrigerant return during defrost operations, which can damage the compressor and reduce energetic efficiency due to refrigerant fluid heating within the compressor shell before entering the suction muffler.
Innovation Solution
A suction arrangement where the inlet nozzle of the admission tube is positioned adjacent and external to the axial projection of the outlet nozzle of the suction-inlet tube, with a deflecting means to direct the gaseous phase into the inlet nozzle while preventing liquid phase entry, minimizing the risk of liquid refrigerant admission into the compression chamber and avoiding undesirable heating of the refrigerant fluid.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If the suction-inlet tube is opened to the interior of the hermetic shell (open suction arrangement), then the refrigerant fluid can be heated during its permanence in the interior of the shell, but this heating reduces the volumetric pumping capacity and energetic efficiency of the compressor
Solution Approach 1:
The suction-inlet tube is positioned to extend through the hermetic shell wall with its outlet nozzle oriented outward, extracting the refrigerant fluid directly from the shell exterior into the suction muffler without allowing it to enter and be heated by the interior components of the hermetic shell. This extraction approach eliminates the harmful heating effect while maintaining the suction function.
Solution Approach 2:
The suction muffler serves as an intermediary component that receives the refrigerant fluid directly from the suction-inlet tube outlet nozzle and directs it to the compression chamber, bypassing the hot interior environment of the hermetic shell. This intermediary structure enables direct suction while protecting the refrigerant fluid from unwanted heating.
2Loss of energy
If a direct-suction arrangement is used to improve energetic efficiency, then the refrigerant fluid is not subjected to hot components, but liquid refrigerant can be admitted in the compression chamber causing damage
Solution Approach 1:
The suction muffler interior is designed with specific local characteristics including a liquid accumulation region at the bottom and a gas admission region above it. The inlet nozzle of the admission tube is positioned to face the gas region, creating local quality differentiation that allows gaseous refrigerant to be admitted efficiently while liquid refrigerant accumulates at the bottom and is excluded from the compression chamber.
Solution Approach 2:
The suction-inlet tube outlet nozzle extends partially into the hermetic shell interior with its opening oriented outward, creating a partial direct-suction path. This partial extension allows the gaseous refrigerant to be efficiently directed into the suction muffler while the liquid refrigerant, being heavier, accumulates in the lower region and does not enter the compression chamber, thus achieving both efficiency and safety.
3Reliability
If the inlet nozzle of the admission tube is positioned spaced from the outlet nozzle of the suction-inlet tube, then liquid refrigerant can be prevented from entering, but the gaseous phase must travel a longer path and may be subjected to heating
Solution Approach 1:
The inlet nozzle of the admission tube is positioned asymmetrically relative to the outlet nozzle of the suction-inlet tube, with its opening facing a specific direction toward the gas region. This asymmetric positioning allows the gaseous refrigerant to be efficiently captured while the liquid refrigerant, following a different flow path due to gravity and momentum, accumulates at the bottom and is excluded from the compression chamber.
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 arrangement effectively reduces the suction of the liquid phase by approximately 80% and maintains high energetic efficiency by ensuring only the gaseous phase enters the compression chamber, preventing damage and maintaining compressor performance during defrost operations.
Implementation Method 1
a deflecting means to direct the gaseous phase into the inlet nozzle while preventing liquid phase entry
Implementation Method 2
This arrangement effectively reduces the suction of the liquid phase by approximately 80% and maintains high energetic efficiency by ensuring only the gaseous phase enters the compression chamber
Data Source
AI summary
A refrigeration compressor is provided and may include a shell carrying a suction-inlet tube having an outlet nozzle opened to the interior of the shell and a cylinder block to which is mounted a suction muffler that incorporates an admission tube provided with an inlet nozzle.The inlet nozzle of the admission tube may be disposed adjacent to the outlet nozzle of the suction-inlet tube. The inlet nozzle may admit under at least one of the conditions of underpressure in its interior or deflection of the refrigerant-fluid flow in the interior of the shell the gaseous phase and may direct the liquid phase to a region of the shell external to the inlet nozzle.