Dynamic compressor and refrigeration cycle device

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Solution Overview

Problem

Existing refrigeration cycle apparatuses with two-stage compressors face inefficiencies due to the inability to remove the degree of superheat generated in the compression process, leading to increased compression power requirements and power consumption.

Innovation Solution

A dynamic compressor with a rotating body, impeller, and specific flow paths that allow for the injection of liquid-phase refrigerant into the gas-phase refrigerant flow path, facilitating heat exchange and reducing the enthalpy increase caused by superheat, thereby reducing compression power and power consumption.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Temperature

If a two-stage compressor system with a steam cooler is used, then the degree of superheat of refrigerant entering the second-stage compressor can be reduced, but the degree of superheat generated in the compression process cannot be removed

Engineering Contradiction:
Improvedegree of superheat of refrigerantVSAvoidcompression power
Core Design Contradiction:
TemperatureVSLoss of energy

Solution Approach 1:

The patent merges the cooling function with the compression process by integrating a liquid-phase refrigerant injection system directly into the compression chamber. The liquid refrigerant is injected through injection holes in the compression element, allowing heat exchange to occur simultaneously with compression, thereby removing superheat during the compression process itself rather than in a separate cooling stage.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The patent introduces liquid-phase refrigerant as an intermediary substance to facilitate heat exchange during compression. This liquid refrigerant absorbs heat from the superheated gas-phase refrigerant through direct contact, enabling the removal of compression-generated superheat without requiring external cooling equipment.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Loss of energy

If liquid-phase refrigerant is injected into the compression chamber, then compression power is reduced by removing superheat, but the device complexity increases

Engineering Contradiction:
Improvecompression powerVSAvoidcompressor structure
Core Design Contradiction:
Loss of energyVSDevice complexity

Solution Approach 1:

The compression element serves multiple functions: it compresses the gas-phase refrigerant, provides injection holes for liquid refrigerant, and acts as a mixing chamber for heat exchange. This multi-functionality reduces the need for separate components, thereby limiting the increase in device complexity while achieving the cooling effect.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Solution Approach 2:

The patent changes the phase parameter of the refrigerant by injecting liquid-phase refrigerant into the compression chamber. This phase change enables the liquid to absorb heat from the superheated gas, removing superheat and reducing compression power requirements.

Inventive Principle:
Principle #35Parameter changes

3Productivity

If liquid-phase refrigerant is injected during compression, then the efficiency of the refrigeration cycle is improved, but the manufacturing precision requirements increase

Engineering Contradiction:
Improverefrigeration cycle efficiencyVSAvoidinjection flow path
Core Design Contradiction:
ProductivityVSManufacturing precision

Solution Approach 1:

The injection system is segmented into multiple injection holes distributed on the compression element. This segmentation allows for simplified manufacturing of each individual hole while achieving uniform liquid refrigerant distribution across the compression chamber, thereby reducing overall manufacturing precision requirements despite the added functionality.

Inventive Principle:
Principle #1Segmentation

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

The dynamic compressor effectively reduces the compression power needed to achieve a predetermined pressure, enhancing the efficiency of the refrigeration cycle by continuously cooling the superheated gas-phase refrigerant through sensible or latent heat from the liquid-phase refrigerant.

Implementation Method 1

heat exchange is indirectly performed between a cooling medium, such as air, and the refrigerant vapor

Methodology Applied
Scientific EffectHeat exchange: Heat Exchanger

Implementation Method 2

continuously cooling the superheated gas-phase refrigerant through sensible or latent heat from the liquid-phase refrigerant

Methodology Applied
Scientific EffectSensible heat:

Implementation Method 3

continuously cooling the superheated gas-phase refrigerant through sensible or latent heat from the liquid-phase refrigerant

Methodology Applied
Scientific EffectLatent heat: Latent Heat

Data Source

PatentEP3763948B1Dynamic compressor and refrigeration cycle device
Publication Date: 2023.09.06 PANASONIC HOLDINGS CORP
  • EP3763948B1 patent drawingFigure 1
  • EP3763948B1 patent drawingFigure 2
  • EP3763948B1 patent drawingFigure 3

AI summary

A dynamic compressor includes a rotating body including a rotating shaft and at least one impeller, a refrigerant flow path that is located around the rotating body and that enables a gas-phase refrigerant to flow therethrough, a main flow path that extends in the axial direction of the rotating body inside the rotating body and that enables a liquid-phase refrigerant to flow therethrough, and an injection flow path that is located inside the rotating body and that branches off from the main flow path and extends from the main flow path to the refrigerant flow path so as to lead a liquid-phase refrigerant from the main flow path to the refrigerant flow path.