Radiant Indoor Refrigerant Piping for Compressor Oil Return

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Solution Overview

Problem

The integration of a radiant indoor machine with a convective indoor machine in air conditioning systems leads to oil accumulation in refrigerant pipes due to reduced refrigerant flow speed, potentially damaging the compressor and reducing its reliability.

Innovation Solution

The air conditioning system incorporates a radiant indoor machine with a refrigerant pipe having a smaller inner diameter than the main refrigerant piping, featuring a meandering design with branching and collecting parts to maintain refrigerant flow speed and prevent oil separation, while optimizing heat radiation efficiency.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a radiant indoor machine is added to the air conditioner, then the degree of comfort and heating effect are improved, but the refrigerant flow speed decreases causing oil accumulation

Engineering Contradiction:
Improvecompressor reliabilityVSAvoidrefrigerant flow speed
Core Design Contradiction:
ReliabilityVSSpeed

Solution Approach 1:

The patent changes the physical parameters of the refrigerant pipe by reducing its inner diameter in the radiant indoor machine. This parameter change increases the flow velocity of the refrigerant despite the extended piping length, preventing oil accumulation while maintaining the radiant heating/cooling function.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent applies different pipe diameter specifications to different sections of the refrigerant piping system. The refrigerant pipe in the radiant indoor machine has a smaller inner diameter compared to the main refrigerant piping, creating local quality variation that optimizes flow characteristics in the radiant section.

Inventive Principle:
Principle #3Local quality

2Adaptability or versatility

If the refrigerant piping is lengthened to add a radiant indoor machine, then the air conditioning coverage is improved, but oil separation occurs due to reduced flow speed

Engineering Contradiction:
Improveair conditioning coverageVSAvoidoil separation
Core Design Contradiction:
Adaptability or versatilityVSObject-generated harmful factors

Solution Approach 1:

The patent modifies the inner diameter parameter of the refrigerant pipe in the radiant indoor machine section. This parameter change compensates for the increased piping length, maintaining sufficient flow velocity to prevent oil separation while extending the air conditioning coverage to include the radiant unit.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent creates a localized modification in the refrigerant pipe design where the radiant indoor machine section has a smaller inner diameter. This local quality adjustment ensures that oil separation is prevented specifically in the extended radiant section without affecting the overall system performance.

Inventive Principle:
Principle #3Local quality

3Speed

If the compressor capacity is enhanced to maintain refrigerant flow speed, then the oil accumulation problem is solved, but the system cost increases

Engineering Contradiction:
Improverefrigerant flow speedVSAvoidsystem cost
Core Design Contradiction:
SpeedVSEase of manufacture

Solution Approach 1:

The patent changes the inner diameter parameter of the refrigerant pipe instead of increasing compressor capacity. This parameter modification achieves the desired flow velocity increase at lower cost, as it involves pipe specification changes rather than upgrading the expensive compressor component.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent applies a localized solution by modifying only the refrigerant pipe in the radiant indoor machine section. This approach is more cost-effective than enhancing the entire compressor system, as it targets the specific problem area with a focused, minimal-cost intervention.

Inventive Principle:
Principle #3Local quality

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 configuration prevents oil accumulation and compressor damage, maintains refrigerant flow speed, and enhances overall system efficiency, reducing the need for compressor upgrades and lowering operational costs.

Implementation Method 1

a refrigerant pipe (110) connecting between the convective indoor machine (2) and the outdoor machine (1) and having an inner diameter smaller than that of the refrigerant piping (7)... not reducing the flow speed of refrigerant flowing through the radiant indoor machine prevents oil accumulation from being caused

Methodology Applied
Scientific EffectFluid flow velocity increase through reduced diameter: Pressure Gradient

Implementation Method 2

a refrigerant pipe (110) connecting between the convective indoor machine (2) and the outdoor machine (1) and having an inner diameter smaller than that of the refrigerant piping (7), the refrigerant pipe (110) including a plurality of vertically juxtaposed straight pipes (112) and connection pipes (114) connecting between upper ends of the adjacent straight pipes (112) and between lower ends thereof

Methodology Applied
Scientific EffectHeat exchange through meandering pipe configuration: Convection

Data Source

PatentEP3141824B1Air conditioning system
Publication Date: 2020.09.16 ECO FACTORY CO LTD
  • EP3141824B1 patent drawingFigure 1
  • EP3141824B1 patent drawingFigure 2(a)~2(b)
  • EP3141824B1 patent drawingFigure 3

AI summary

[Problem] To provide an air conditioning system which includes a convective indoor machine and a radiant indoor machine to prevent separation of lubricating oil in refrigerant and consequently prevent damage to a compressor, and can prevent lowering in reliability of the compressor. [Solution] The air conditioning system includes: an air conditioner having a compressor 3, an outdoor heat exchanger 4, an expansion valve 5, a convective indoor machine 2 and a refrigerant piping connecting them; and a radiant indoor machine 10 which is arranged between the convective indoor machine 2 and the compressor 3 and has a refrigerant pipe having an inner diameter smaller than that of the refrigerant piping.