Multi-Injection Compressor Layout for Stable Heat Pump Operation

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing air conditioners face challenges in maintaining sufficient refrigerant circulation for optimal cooling and heating performance, especially at extreme outside air temperatures, requiring large and costly compressors and struggling with insufficient refrigerant circulation when using only two refrigerant injection ports.

Innovation Solution

The air conditioner employs a multi-stage compression system with multiple refrigerant injection flow paths and expansion units, including first, second, and third injection flow paths, and corresponding injection expansion units, which allow for selective refrigerant injection and bypass, optimizing refrigerant circulation and supercooling during both heating and cooling operations.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a large capacity compressor is used to ensure sufficient refrigerant circulation at extreme temperatures, then cooling and heating performance is improved, but manufacturing cost and installation cost increase

Engineering Contradiction:
Improvecooling and heating performanceVSAvoidmanufacturing cost
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The patent divides the single compression process into multiple stages by introducing intermediate refrigerant injection points. The compression process is segmented into first compression, intermediate injection, second compression, and final injection stages. This segmentation allows the use of a smaller compressor capacity while achieving the same refrigeration effect through multiple incremental compression steps, thereby reducing manufacturing costs while maintaining performance.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent applies preliminary cooling action by injecting refrigerant at intermediate stages of compression. The injected refrigerant is pre-cooled before entering the compression chamber, and this preliminary cooling effect accumulates across multiple injection stages. This allows the system to achieve sufficient refrigerant circulation and cooling performance without requiring an oversized compressor, thus reducing manufacturing costs.

Inventive Principle:
Principle #10Preliminary action

2Device complexity

If only two refrigerant injection ports are used, then device complexity is reduced, but sufficient refrigerant circulation cannot be achieved at very high or low outside air temperatures

Engineering Contradiction:
Improvenumber of injection portsVSAvoidrefrigerant circulation sufficiency
Core Design Contradiction:
Device complexityVSReliability

Solution Approach 1:

The patent segments the refrigerant injection process into multiple distinct ports positioned at different locations within the compression chamber. Instead of using two injection ports, the system employs four injection ports that are spatially segmented to inject refrigerant at different stages of the compression cycle. This segmentation enables sufficient refrigerant circulation at extreme temperatures while keeping each individual injection port simple in design.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent transitions from a temporal injection approach (two injections per cycle) to a spatial injection approach (four injection ports at different locations). By distributing injection ports across different spatial positions within the compression chamber, the system achieves multiple effective injections without increasing temporal complexity, thus maintaining device simplicity while improving refrigerant circulation reliability.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

3Reliability

If multiple refrigerant injection flow paths and expansion units are added, then refrigerant circulation and supercooling are enhanced, but device complexity increases

Engineering Contradiction:
Improverefrigerant circulationVSAvoidnumber of flow paths and expansion units
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent designs the injection expansion units to serve multiple functions simultaneously. Each expansion unit not only expands the injected refrigerant but also acts as a throttling device, a mixing chamber, and a temperature control mechanism. This multi-functionality reduces the need for separate dedicated components for each function, thereby enhancing refrigerant circulation and supercooling while limiting the increase in overall device complexity.

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

Solution Approach 2:

The patent merges the expansion function and injection function into integrated expansion-injection units. Rather than having separate expansion devices and separate injection mechanisms, the system combines these functions into unified components that perform both expansion and injection operations. This merging reduces the total number of discrete components and flow paths while achieving the desired enhancement in refrigerant circulation and supercooling effects.

Inventive Principle:
Principle #5Merging (Combining)

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 enhances refrigerant circulation and supercooling, improving the air conditioner's performance and efficiency by allowing for multiple refrigerant injections during heating and optimizing refrigerant flow during cooling, reducing the need for large compressors and enhancing operational stability.

Implementation Method 1

first and second injection expansion units provided respectively in the first and second injection flow paths, the first and second injection expansion units being configured to expand a refrigerant to be injected into the compression chamber

Methodology Applied
Scientific EffectThrottling expansion: Joule-Thomson Effect

Implementation Method 2

an injection passage through which the refrigerant passing through the supercooling device is introduced into an injection inflow part of the compressor

Methodology Applied
Scientific EffectSupercooling: Supercooling

Data Source

PatentEP3043125B1Air conditioner
Publication Date: 2018.10.24 LG ELECTRONICS INC
  • EP3043125B1 patent drawingFigure 1
  • EP3043125B1 patent drawingFigure 2
  • EP3043125B1 patent drawingFigure 3

AI summary

An air conditioner is provided. The air conditioner includes a compressor having a suction unit and a plurality of injection inlets, an inside heat exchanger into which refrigerant compressed in the compressor is introduced during a heating operation, an outside heat exchanger into which refrigerant compressed in the compressor is introduced during a cooling operation, a plurality of refrigerant separation devices through which refrigerant condensed in the inside heat exchanger or the outside heat exchanger pass, a plurality of injection flow paths which extends from the three refrigerant separation devices to the plurality of injection inlets, and a bypass flow path which extends from any one injection flow path among the plurality of injection flow paths to the suction unit of the compressor.