Scroll Compressor Cutout Discharge Port Backflow Reduction

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Solution Overview

Problem

Scroll compressors experience pressure loss due to fluid backflow when the communication area between compression chambers and the discharge port suddenly increases, which can exceed the reduction in pressure loss achieved by optimizing the communication area size.

Innovation Solution

A scroll compressor design with a fixed and movable scroll, where the cutout portion passes through the discharge port profile, creating a small flow passage area for initial fluid discharge, reducing backflow by gradually increasing the communication area as the crankshaft rotates, with specific angle positions and rate increases to manage flow rates effectively.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of energy

If the communication area between compression chambers and discharge port suddenly becomes larger at the moment of communication, then the pressure loss at the discharge port is reduced, but fluid backflow occurs causing pressure loss

Engineering Contradiction:
Improvepressure loss at discharge portVSAvoidfluid backflow
Core Design Contradiction:
Loss of energyVSObject-generated harmful factors

Solution Approach 1:

The cutout portion is designed to pass through the discharge port profile before the main communication occurs, creating a preliminary discharge path. This preliminary action reduces the pressure difference between compression chambers and discharge port in advance, preventing sudden backflow when full communication occurs.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The discharge communication process is segmented into two phases: initial communication through the cutout portion (small area) and subsequent full communication (large area). This segmentation allows controlled pressure equalization, reducing harmful backflow effects.

Inventive Principle:
Principle #1Segmentation

2Productivity

If the communication area increases rapidly to reduce pressure loss, then discharge efficiency improves, but fluid backflow increases causing pressure loss

Engineering Contradiction:
Improvedischarge efficiencyVSAvoidpressure loss from backflow
Core Design Contradiction:
ProductivityVSLoss of energy

Solution Approach 1:

The cutout portion enables preliminary discharge action that prepares the system for efficient main discharge. By reducing pressure difference in advance, the subsequent rapid communication occurs with minimal backflow, maintaining high discharge efficiency without energy loss.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The communication area dynamics are controlled through the moving cutout portion that progressively opens the discharge path. This dynamic control allows the system to transition smoothly from initial to full communication, optimizing both discharge efficiency and preventing backflow.

Inventive Principle:
Principle #15Dynamics

Data Source

PatentEP3492746B1Scroll compressor
Publication Date: 2022.10.19 DAIKIN INDUSTRIES LTD
  • EP3492746B1 patent drawingFigure 1
  • EP3492746B1 patent drawingFigure 2
  • EP3492746B1 patent drawingFigure 3~4

AI summary

A scroll compressor (10) has a fixed scroll (51), a movable scroll (52), and a crankshaft (30). The movable scroll (52) can revolve with respect to the fixed scroll (51). The crankshaft (30) can rotate while causing the movable scroll (52) to revolve. A discharge port (55) is formed in one of the fixed scroll (51) or the movable scroll (52), and a cutout portion (56) is formed in the other. The cutout portion (56) formed in the other at least partially passes through the profile of the discharge port (55) formed in the one because of the revolution of the movable scroll (52).