Refrigeration cycle apparatus

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Solution Overview

Problem

Existing refrigeration cycle apparatuses face the issue of the compressor's internal temperature excessively rising due to insufficient refrigerant discharge, leading to potential compressor failure, especially when the water temperature exceeds the air temperature, causing insufficient refrigerant circulation.

Innovation Solution

A refrigeration cycle apparatus with a bypass refrigerant circuit and a controller that opens bypass valves when the water temperature exceeds a predetermined threshold relative to the air temperature, increasing refrigerant suction and circulation to prevent excessive temperature rise.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Quantity of substance

If the water temperature is high (exceeds air temperature by predetermined threshold), then the refrigerant discharge from compressor becomes insufficient, but the compressor internal temperature excessively rises

Engineering Contradiction:
Improverefrigerant discharge quantityVSAvoidcompressor internal temperature
Core Design Contradiction:
Quantity of substanceVSTemperature

Solution Approach 1:

A bypass valve is introduced as an intermediary component that provides an alternative refrigerant flow path from the compressor discharge side back to the suction side. This mediator allows excess refrigerant to recirculate when the main refrigerant circuit cannot accept sufficient refrigerant due to high water temperatures, thereby preventing compressor overheating while maintaining proper refrigerant circulation

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The bypass valve is opened in advance when the controller detects that water temperature exceeds air temperature by a predetermined threshold. This preliminary action establishes the refrigerant recirculation path before the compressor experiences excessive temperature rise, preventing the harmful effect before it occurs

Inventive Principle:
Principle #10Preliminary action

2Quantity of substance

If the water temperature exceeds air temperature by predetermined threshold, then refrigerant circulation becomes insufficient, but compressor reliability deteriorates

Engineering Contradiction:
Improverefrigerant circulationVSAvoidcompressor reliability
Core Design Contradiction:
Quantity of substanceVSReliability

Solution Approach 1:

The bypass valve serves as a mediator that ensures continuous refrigerant circulation through an alternative path when the primary refrigerant circuit is restricted by high water temperatures. This maintains minimum refrigerant flow through the compressor, preventing lubrication failure and overheating, thereby preserving compressor reliability

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The bypass refrigerant circuit acts as a cushioning mechanism that is activated in advance when temperature conditions indicate potential refrigerant circulation problems. This pre-established alternative path buffers against the harmful effects of insufficient refrigerant circulation, protecting the compressor from damage

Inventive Principle:
Principle #11Beforehand cushioning (Prior cushioning)

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 solution effectively prevents the compressor's internal temperature from rising excessively by enhancing refrigerant circulation, thereby preventing compressor failure and ensuring stable operation.

Implementation Method 1

a first bypass refrigerant circuit providing communication between the main refrigerant circuit on a downstream side of the compressor and the main refrigerant circuit on an upstream side of the compressor

Methodology Applied
Scientific EffectPressure gradient: Pressure Gradient

Implementation Method 2

the use side heat exchanger being connected to a water pipe and being configured to perform heat exchange between water flowing through the water pipe and the refrigerant flowing through the main refrigerant circuit

Methodology Applied
Scientific EffectHeat exchange: Heat Exchanger

Data Source

PatentEP4603762A1Refrigeration cycle apparatus
Publication Date: 2025.08.20 PANASONIC INTELLECTUAL PROPERTY MANAGEMENT CO LTD
  • EP4603762A1 patent drawingFigure 1
  • EP4603762A1 patent drawingFigure 2
  • EP4603762A1 patent drawingFigure 3

AI summary

The present disclosure provides a refrigeration cycle apparatus that can restrain the internal temperature of a compressor from excessively rising at the start of the compressor. The refrigeration cycle apparatus in the present disclosure includes: a first bypass refrigerant circuit providing communication between a main refrigerant circuit on a downstream side of a compressor and the main refrigerant circuit on an upstream side of the compressor; a first bypass valve provided in the first bypass refrigerant circuit, the first bypass valve being configured to open and close the first bypass refrigerant circuit; a water temperature sensor configured to detect a temperature of water flowing into a use side heat exchanger from a water pipe; and a controller configured to recognize an operating state of the compressor based on the temperature detected by the water temperature sensor at start of the compressor and bring the first bypass refrigerant circuit into an open state using the first bypass valve when recognizing that the compressor is in a predetermined insufficient refrigerant discharge state.