Mixed-Refrigerant Heat Exchanger Layout for Uniform Cooling

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Solution Overview

Problem

The existing refrigerating apparatuses with nonazeotropic refrigerant mixtures face challenges in achieving sufficient cooling efficiency and uniform temperature distribution due to the difficulty in liquefying second and third refrigerants with lower evaporation temperatures, leading to increased manufacturing costs and uneven temperature distribution inside the storage.

Innovation Solution

The refrigerating apparatus incorporates a refrigerant circuit with a compressor, condenser, and two heat exchangers that utilize a nonazeotropic refrigerant mixture, where the first refrigerant with a higher evaporation temperature is used to liquefy the second and third refrigerants through a countercurrent heat exchange process, enhancing the liquefaction efficiency and uniform temperature distribution.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If air-cooling method is used in heat exchanger, then manufacturing cost is reduced, but liquefaction efficiency of second and third refrigerants is insufficient

Engineering Contradiction:
Improvemanufacturing costVSAvoidliquefaction efficiency
Core Design Contradiction:
Ease of manufactureVSProductivity

Solution Approach 1:

The patent introduces a heat exchanger as an intermediary device that enables efficient heat transfer between the first refrigerant and the second/third refrigerants. This heat exchanger acts as a mediator to achieve effective liquefaction of the lower-temperature refrigerants without requiring complex compression systems, thereby maintaining manufacturing cost efficiency while improving liquefaction efficiency.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Temperature

If second and third refrigerants with lower evaporation temperatures are used, then cooling ability is enhanced, but liquefaction becomes difficult and temperature distribution becomes uneven

Engineering Contradiction:
Improvecooling abilityVSAvoidtemperature distribution uniformity
Core Design Contradiction:
TemperatureVSReliability

Solution Approach 1:

The patent applies local quality by positioning the heat exchanger at specific locations where it can effectively transfer heat to the second and third refrigerants. The heat exchanger is strategically placed to ensure uniform heat distribution throughout the refrigeration system, addressing the temperature distribution uniformity issue while maintaining the enhanced cooling ability provided by the lower-temperature refrigerants.

Inventive Principle:
Principle #3Local quality

3Device complexity

If conventional refrigerant circuit is used, then system complexity is low, but cooling efficiency is insufficient

Engineering Contradiction:
Improvesystem complexityVSAvoidcooling efficiency
Core Design Contradiction:
Device complexityVSProductivity

Solution Approach 1:

The patent implements multi-functionality by designing the heat exchanger to serve multiple purposes: it cools the second and third refrigerants, facilitates heat transfer between different refrigerant streams, and contributes to overall system efficiency. This universal approach enhances cooling efficiency without requiring additional separate components, thereby maintaining relatively low system complexity.

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

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 improves cooling efficiency, reduces manufacturing costs, and ensures even temperature distribution inside the storage by effectively liquefying the second and third refrigerants, maintaining the evaporation temperature at a design level.

Implementation Method 1

a refrigerant circuit having a compressor 101, a condenser 104, a first heat exchanger 112 and a second heat exchanger 114

Methodology Applied
Scientific EffectHeat exchange: Heat Exchanger

Implementation Method 2

the second refrigerant and the third refrigerant having evaporation temperatures lower than that of the first refrigerant is sealed

Methodology Applied
Scientific EffectLiquefaction through cooling: Condensation

Implementation Method 3

an evaporator 117, and a nonazeotropic refrigerant mixture having first to third refrigerants is sealed

Methodology Applied
Scientific EffectEvaporation: Evaporation

Implementation Method 4

a refrigerant circuit having a compressor 101

Methodology Applied
Scientific EffectCompression: Compression

Data Source

PatentEP2322876B1Refrigeration system
Publication Date: 2018.10.31 PHC HLDG CORP
  • EP2322876B1 patent drawingFigure 1
  • EP2322876B1 patent drawingFigure 2
  • EP2322876B1 patent drawingFigure 3

AI summary

A refrigerating apparatus includes a refrigerating cycle including a compressor, a condenser, a flow divider, a first heat exchanger, a second heat exchanger, a decompressing device, and an evaporator, connected circularly with a refrigerant piping, the refrigerant cycle having sealed therein a mixed refrigerant obtained by mixing at least first to third refrigerants with different evaporation temperatures, the first heat exchanger and the second heat exchanger each including a double pipe to form a first flow passage provided inside the double pipe, a second flow passage provided outside the double pipe, and an intermediate port in a piping connecting between the second flow passage of the first heat exchanger and the second flow passage of the second heat exchanger, a refrigerant circuit being provided in which a high-temperature and high-pressure refrigerant discharged from the compressor is cooled by the condenser to liquefy the first refrigerant having a high evaporation temperature, and thereafter, the liquid refrigerant obtained by dividing a refrigerant in the flow divider being decompressed, and thereafter supplied to the second flow passage of the first heat exchanger via the intermediate port, evaporated toward one port of the second flow passage, and supplied to a sucking side of the compressor via the one port of the second flow passage of the first heat exchanger, a refrigerant circuit being provided in which, a gas-state refrigerant obtained by dividing a refrigerant in the flow divider is supplied to the first flow passage of the first heat exchanger, and thereafter passed through the first flow passage to liquefy the second refrigerant with an evaporation temperature which is high next to the first refrigerant, and thereafter passed through the first flow passage of the second heat exchanger to liquefy the third refrigerant, and thereafter, via the decompressing device, passed through the evaporator to evaporate the second and third refrigerants, and thereafter passed through the second flow passage of the second heat exchanger and the second flow passage of the first heat exchanger, and thereafter departs from the other port of the second flow passage of the first heat exchanger via the one port, and arrives at the sucking side of the compressor, and thereby a refrigerant in the first flow passage of the first heat exchanger and the second heat exchanger and a refrigerant in the second flow passage of the first heat exchanger and the second heat exchanger having a countercurrent relationship, and having a temperature relationship in a manner that the refrigerant flowing through the second flow passage cools the refrigerant flowing through the first flow passage.