Compressor, refrigeration cycle device, and heat pump hot-water supply device

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Solution Overview

Problem

Existing compressors in refrigeration cycle devices face inefficiencies due to the inability to effectively separate high pressure refrigerant gas and refrigerator oil, leading to increased rotational resistance, reduced heat transfer performance, and increased pressure loss, as the density difference between the two fluids is not sufficient for efficient centrifugal separation.

Innovation Solution

A compressor design incorporating a non-rotational oil separation mechanism within the second intake passage, which increases the cross-sectional area of this passage to reduce flow speed and prevent mixing, allowing for efficient separation of refrigerant gas and oil without rotation, thereby reducing the amount of oil discharged and enhancing energy efficiency.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Quantity of substance

If centrifugal force is used to separate high pressure refrigerant gas and refrigerator oil, then separation is attempted, but the small density difference causes inefficient separation and promotes mixing instead

Engineering Contradiction:
Improveamount of refrigerator oil dischargedVSAvoidseparation efficiency
Core Design Contradiction:
Quantity of substanceVSProductivity

Solution Approach 1:

The patent replaces the centrifugal mechanical separation system with a gravitational separation system. By removing the rotating components and using a stationary separation chamber, the system relies on gravity to separate the refrigerant gas and refrigerator oil based on their density difference, avoiding the mixing problem caused by centrifugal force

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent changes the separation mechanism from dynamic (centrifugal) to static (gravitational). By altering the separation parameter from rotational acceleration to gravitational acceleration, the system achieves effective separation despite the small density difference between refrigerant gas and refrigerator oil

Inventive Principle:
Principle #35Parameter changes

2Duration of action of moving object

If high pressure refrigerant gas and refrigerator oil are circulated through the refrigeration cycle, then the cycle continues, but heat transfer is inhibited and pressure loss increases

Engineering Contradiction:
Improvecontinuous operation of refrigeration cycleVSAvoidheat transfer efficiency and pressure loss
Core Design Contradiction:
Duration of action of moving objectVSLoss of energy

Solution Approach 1:

The patent extracts the refrigerator oil from the high pressure refrigerant gas stream using a separation chamber before the refrigerant enters the heat exchanger. By removing the oil that would otherwise inhibit heat transfer and cause pressure loss, the system maintains continuous operation with improved energy efficiency

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent introduces a separation chamber as an intermediary component between the discharge passage and the heat exchanger. This intermediary device allows the refrigerant gas and refrigerator oil to separate before the refrigerant enters the heat transfer process, preventing energy losses

Inventive Principle:
Principle #24Intermediary (Mediator)

3Productivity

If refrigerator oil adheres to the electric actuating element, then the compression process continues, but rotational resistance increases

Engineering Contradiction:
Improvecompression operation continuityVSAvoidrotational resistance
Core Design Contradiction:
ProductivityVSForce

Solution Approach 1:

The patent extracts the refrigerator oil from the system before it can adhere to the electric actuating element. By separating and removing the oil in the separation chamber, the system maintains continuous compression operation without the increasing rotational resistance that would result from oil accumulation

Inventive Principle:
Principle #2Taking out (Extraction)

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 design effectively utilizes thermal energy from hot refrigerator oil, reduces rotational resistance, and minimizes oil circulation, improving energy efficiency and preventing heat transfer inhibition and pressure loss in heat exchangers.

Implementation Method 1

non-rotational oil separation means included with the second intake passage, for separating the high pressure refrigerant and the refrigerator oil without rotating the high pressure refrigerant and the refrigerator oil

Methodology Applied
Scientific EffectFlow separation: Flow Separation

Implementation Method 2

increases the cross-sectional area of this passage to reduce flow speed and prevent mixing

Methodology Applied
Scientific EffectFlow velocity reduction:

Data Source

PatentEP2927622B1Compressor, refrigeration cycle device, and heat pump hot-water supply device
Publication Date: 2020.08.19 MITSUBISHI ELECTRIC CORP
  • EP2927622B1 patent drawingFigure 1
  • EP2927622B1 patent drawingFigure 2
  • EP2927622B1 patent drawingFigure 3

AI summary

The compressor includes: a first intake passage for guiding refrigerant to a compressing element without releasing the refrigerant into the sealed container; a first discharge passage for discharging a compressed high pressure refrigerant and refrigerator oil from the compressing element directly to an outside of the sealed container without releasing the high pressure refrigerant into the sealed container and without separating the high pressure refrigerant and the refrigerator oil; a second intake passage for guiding the high pressure refrigerant and the refrigerator oil having passed through an external heat exchanger into the sealed container; non-rotational oil separation means included with the second intake passage, for separating the high pressure refrigerant and the refrigerator oil without rotating; and a second discharge passage for discharging the high pressure refrigerant in the sealed container to the outside of the sealed container without compressing the high pressure refrigerant.