Refrigeration cycle apparatus

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

In refrigeration cycle systems with multiple distribution units connected via a distribution pipe, inclination of the pipe leads to uneven refrigerant distribution, resulting in uneven air-conditioning capacities among units, with some units failing to supply the necessary cooling capacity.

Innovation Solution

A refrigeration cycle apparatus with a heat source unit connected to first and second distribution units via a distribution pipe, where the distribution units include heat exchangers that increase the degree of subcooling to correct uneven refrigerant distribution, ensuring balanced capacity among units by adjusting the subcooling target values based on detected capacity differences.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If the distribution pipe is inclined with respect to the horizontal, then the refrigerant can be distributed to multiple distribution units, but the refrigerant is unevenly distributed with uneven proportion of gas and liquid

Engineering Contradiction:
Improvedistribution capabilityVSAvoidrefrigerant distribution uniformity
Core Design Contradiction:
Adaptability or versatilityVSManufacturing precision

Solution Approach 1:

The patent changes the physical state parameter of the refrigerant by increasing subcooling degree. By subcooling the refrigerant to a lower temperature before distribution, the refrigerant maintains a more stable liquid-gas ratio even when the distribution pipe is inclined, thereby resolving the uneven distribution problem without requiring horizontal pipe installation

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent applies preliminary subcooling to the refrigerant before it enters the distribution pipe. This preliminary action of cooling the refrigerant below its condensation temperature ensures that the refrigerant remains in a controlled two-phase state during distribution, preventing excessive gas accumulation in inclined sections

Inventive Principle:
Principle #10Preliminary action

2Reliability

If the refrigerant is unevenly distributed into distribution units, then the distribution units have uneven air-conditioning capacities, but increasing subcooling degree corrects the capacity unevenness

Engineering Contradiction:
Improveair-conditioning capacity sufficiencyVSAvoidcontrol complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent implements a feedback control mechanism where the control unit monitors the air-conditioning capacity of each distribution unit and adjusts the subcooling degree accordingly. When capacity unevenness is detected, the system increases subcooling to correct the imbalance, creating a closed-loop control system that maintains reliable performance

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The patent dynamically adjusts the subcooling degree parameter based on detected capacity unevenness. By changing this thermal parameter, the system corrects refrigerant distribution imbalances and ensures all distribution units achieve sufficient air-conditioning capacity

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

The apparatus effectively corrects uneven capacity issues among distribution units by increasing subcooling in units receiving high-quality refrigerant, ensuring consistent air-conditioning performance even when the distribution pipe is inclined.

Implementation Method 1

a degree of subcooling at an outlet of the heat exchanger of one of the first distribution unit and the second distribution unit of which the distributed refrigerant is of high quality is increased

Methodology Applied
Scientific EffectSubcooling: Supercooling

Data Source

PatentEP3287715B1Refrigeration cycle apparatus
Publication Date: 2022.05.25 MITSUBISHI ELECTRIC CORP
  • EP3287715B1 patent drawingFigure 1
  • EP3287715B1 patent drawingFigure 2
  • EP3287715B1 patent drawingFigure 3(a)~4

AI summary

A refrigeration cycle apparatus includes a heat source unit configured to supply refrigerant, a first distribution unit and a second distribution unit respectively connected to the heat source unit, and a distribution pipe located between the heat source unit and the first distribution unit and the second distribution unit for distributing the refrigerant flowing from the heat source unit into the first distribution unit and the second distribution unit. Further, the first distribution unit and the second distribution unit individually include a heat exchanger configured to serve as a condenser. Further, if the refrigerant flowing through the distribution pipe is unevenly distributed into the first distribution unit and the second distribution unit, a degree of subcooling at an outlet of the heat exchanger of one of the first distribution unit and the second distribution unit of which the distributed refrigerant is of high quality is increased.