Scroll Compressor Suction Duct Drain Port Design

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing scroll compressors face challenges in effectively separating and managing lubricant mist within the suction flow path, leading to inefficiencies and potential contamination in the refrigerant compression process.

Innovation Solution

Incorporating a suction duct with a drain port in the scroll compressor housing to direct refrigerant flow and separate lubricant mist, allowing the lubricant to drain into a lubricant sump, thereby facilitating lubricant mist coalescence and separation before it enters the motor shell.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If a suction duct is provided to direct refrigerant flow, then the refrigerant flow path is improved, but lubricant mist separation becomes insufficient

Engineering Contradiction:
Improverefrigerant flow efficiencyVSAvoidlubricant separation effectiveness
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The suction duct is segmented into functional zones: an upper refrigerant flow path and a lower lubricant drainage path. The duct channel is divided such that refrigerant flows through the upper portion while lubricant mist drains through the lower portion into the lubricant sump, achieving effective separation of the two fluid streams.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The suction duct acts as an intermediary structure between the refrigerant inlet and the compression chamber. It mediates the flow by providing a dedicated path for lubricant mist to drain into the lubricant sump before the refrigerant enters the motor shell, preventing direct contact between lubricant and motor components.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Device complexity

If lubricant mist is not effectively separated, then the structure remains simple, but lubricant contamination occurs

Engineering Contradiction:
Improvestructure simplicityVSAvoidlubricant contamination
Core Design Contradiction:
Device complexityVSObject-affected harmful factors

Solution Approach 1:

The suction duct combines multiple functions into a single component: it directs refrigerant flow, separates lubricant mist, and provides a drainage path to the lubricant sump. This merging of functions achieves effective lubricant separation without requiring additional separate components, maintaining structural simplicity.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The suction duct is designed to automatically separate and drain lubricant mist using gravity and flow dynamics. The duct geometry enables lubricant mist to coalesce and drain into the lubricant sump without requiring external power or complex mechanical separation mechanisms.

Inventive Principle:
Principle #25Self-service

3Reliability

If the drain port is positioned at the bottom of the suction duct, then lubricant drainage is improved, but the duct design becomes more complex

Engineering Contradiction:
Improvelubricant drainage effectivenessVSAvoidduct design complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The drain port is positioned at the lowest point (bottom) of the suction duct channel, creating a gravitational equipotential point where lubricant mist naturally accumulates and drains. This positioning utilizes gravity to achieve effective lubricant separation without requiring additional complex drainage mechanisms.

Inventive Principle:
Principle #12Equipotentiality

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 solution enhances the separation of lubricant mist from the refrigerant flow, improving the compressor's efficiency and preventing lubricant contamination, allowing for better lubrication management and reduced operational issues.

Implementation Method 1

facilitate lubricant mist separation prior to gas flow into the motor shell in which coalesced lubricant mist drains through the drain port into the lubricant sump

Methodology Applied
Scientific EffectCoalescence: Coagulation

Implementation Method 2

drain lubricant received in the suction duct into the lubricant sump

Methodology Applied
Scientific EffectGravity: Gravitation

Data Source

PatentEP2347130B1Suction duct and scroll compressor incorporating same
Publication Date: 2018.08.01 BITZER KUEHLMASCHINENBAU GMBH
  • EP2347130B1 patent drawingFigure 1
  • EP2347130B1 patent drawingFigure 2
  • EP2347130B1 patent drawingFigure 3

AI summary

A scroll compressor and assembly includes a suction duct to direct refrigerant from the housing inlet to a location upstream of a motor. Additionally, the suction duct includes drain ports that act to drain oil received in the suction duct into the oil sump. This can be used for filling and charging the oil sump with oil initially by using the common refrigerant inlet port through the housing and also acts to collect coalesced oil from oil mist generated by operation of the scroll compressor in a refrigeration system and likewise drain the lubricant oil into the lubricant sump.