Single-Compressor Cascade Air Conditioner with Independent Pipelines

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Solution Overview

Problem

Existing air-conditioning systems employing double-stage compression with medium-temperature refrigerants face issues such as increased air infiltration, large suction specific volume, and high manufacturing costs due to the use of multiple compressors in cascaded refrigeration cycles.

Innovation Solution

An air-conditioning system with a single compressor and independent pipelines for high and low-temperature refrigerants, featuring separate liquid separators and a shared evaporative condenser, allowing for a cascade refrigeration cycle without the need for multiple compressors.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Temperature

If a cascaded refrigeration cycle with multiple compressors is employed to achieve low evaporation temperature, then the required low temperature can be obtained, but the manufacturing cost increases significantly

Engineering Contradiction:
Improveevaporation temperatureVSAvoidmanufacturing cost
Core Design Contradiction:
TemperatureVSEase of manufacture

Solution Approach 1:

The patent merges the functions of multiple compressors into a single compressor by implementing a shared compression chamber where both high-temperature and low-temperature refrigerants are compressed simultaneously or sequentially. This consolidation eliminates the need for separate compressors while maintaining the cascaded refrigeration cycle's temperature control capabilities, thereby reducing manufacturing cost while achieving the required low evaporation temperature

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The single compressor is designed with multi-functionality to handle both high-temperature and low-temperature refrigerant compression tasks. By incorporating multiple suction ports, discharge ports, and adjustable compression ratios, the compressor can adapt to different refrigeration requirements, replacing multiple specialized compressors with one universal device that performs all compression functions

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

2Temperature

If medium-temperature refrigerant is used in double-stage compression, then the system can operate at low temperatures, but air infiltration into the system increases due to low evaporation pressure

Engineering Contradiction:
Improveevaporation temperatureVSAvoidsystem sealing
Core Design Contradiction:
TemperatureVSReliability

Solution Approach 1:

The patent changes the operating parameters of the refrigeration system by using two different refrigerants with appropriate pressure-temperature characteristics for high and low temperature stages. This parameter change allows the system to maintain positive pressure in both stages, preventing air infiltration while achieving low evaporation temperatures. The pressure parameters are carefully selected to ensure both stages operate above atmospheric pressure

Inventive Principle:
Principle #35Parameter changes

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

Reduces manufacturing costs and improves system reliability and efficiency by utilizing a single compressor, while maintaining effective temperature control and sealing within the compressor.

Implementation Method 1

an evaporative condenser (40)... The refrigerants in the first pipeline (20) and the second pipeline (30) can perform heat exchange with the evaporative condenser (40) respectively

Methodology Applied
Scientific EffectEvaporative condensation: Evaporation

Implementation Method 2

a compressor (10)... the multiple cylinders include a first cylinder (11) and a second cylinder (12)... the outlet of the first liquid separator (51) is in communication with a suction port of the first cylinder (11)

Methodology Applied
Scientific EffectCompression: Compression

Implementation Method 3

a first liquid separator (51) and a second liquid separator (52)... the outlet of the first liquid separator (51) is in communication with a suction port of the first cylinder (11)

Methodology Applied
Scientific EffectGravity separation: Gravitation

Data Source

PatentEP3640549B1Air conditioner system and air conditioner having same
Publication Date: 2025.07.02 ZHUHAI GREE REFRIGERATION TECH CENT OF ENERGY SAVING & ENVIRONMENTAL PROTECTION
  • EP3640549B1 patent drawingFigure 1
  • EP3640549B1 patent drawingFigure 2
  • EP3640549B1 patent drawingFigure 3

AI summary

Disclosed is an air-conditioning system, including: a compressor (10); a first pipeline (20) in communication with the compressor (10); a second pipeline (30) also in communication with the compressor (10), the first pipeline (20) and the second pipeline (30) being independently disposed; an evaporative condenser (40) disposed in the first pipeline (20) and the second pipeline (30), refrigerant in the first pipeline (20) and refrigerant in the second pipeline (30) being separately capable of performing heat exchange with the evaporative condenser (40); a first liquid separator (51) disposed in the first pipeline (20), the first liquid separator (51) having an outlet in communication with the compressor (10); and a second liquid separator (52) disposed in the second pipeline (30), the second liquid separator (52) having an outlet in communication with the compressor (10), and the first liquid separator (51) and the second liquid separator (52) being disposed adjacent to each other. Also disclosed is an air conditioner having the air-conditioning system.