Refrigeration apparatus

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing refrigeration apparatuses face challenges in ensuring proper lubrication of the compressor during startup, as the liquid refrigerant may not be available in sufficient quantity, leading to potential compressor damage, and rely on costly starting pumps for lubrication.

Innovation Solution

The refrigeration apparatus utilizes a refrigerant container connected to the main circuit, where heating means increase the refrigerant pressure to create a pressure differential, allowing spontaneous refrigerant migration to the compressor, eliminating the need for costly pumps by ensuring lubrication through the pressure difference between the container and the main circuit.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a starting pump is used to provide liquid refrigerant to the compressor during startup, then proper lubrication is ensured, but the cost and device complexity increase substantially

Engineering Contradiction:
Improvecompressor lubrication reliabilityVSAvoidsystem complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The invention extracts the starting pump from the system entirely. Instead of using a mechanical pump to force refrigerant circulation, the system relies on natural pressure differentials created by the refrigeration cycle itself to deliver liquid refrigerant to the compressor during startup, thereby eliminating the pump and its associated complexity while maintaining lubrication reliability

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The refrigeration system serves itself during startup by using the pressure differential naturally generated by the refrigeration cycle to circulate liquid refrigerant to the compressor. The high-pressure side of the cycle automatically pushes refrigerant through the bypass line to the compressor, eliminating the need for external assistance from a starting pump

Inventive Principle:
Principle #25Self-service

2Reliability

If liquid refrigerant is stored in the bypass flow passage for compressor lubrication, then proper lubrication is available, but the refrigerant may migrate away due to gravity or insufficient quantity

Engineering Contradiction:
Improvecompressor lubrication availabilityVSAvoidliquid refrigerant quantity
Core Design Contradiction:
ReliabilityVSQuantity of substance

Solution Approach 1:

The invention prepares the system for startup by ensuring liquid refrigerant is positioned in the high-pressure line before the compressor starts. The bypass line is configured to receive liquid refrigerant from the high-pressure side during the compression phase, preparing the lubrication path in advance so that when the compressor starts, liquid refrigerant is immediately available at the bearings

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The invention uses the hydraulic pressure of the refrigerant itself to deliver lubrication. The pressure differential between the high-pressure side (after condenser) and the compressor creates a natural flow that pushes liquid refrigerant through the bypass line to the compressor bearings, using the refrigerant's own pressure rather than gravity or external pumps

Inventive Principle:
Principle #29Pneumatics and hydraulics

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 solution guarantees proper compressor lubrication during startup without relying on pumps, preventing damage and reducing maintenance and operational costs by leveraging the pressure differential to circulate liquid refrigerant to the compressor.

Implementation Method 1

heating means arranged to heat the refrigerant in the container

Methodology Applied
Scientific EffectHeating: Heating

Implementation Method 2

the circulation of liquid refrigerant towards the compressor is obtained by the pressure difference between the refrigerant container and the rest of the main circuit

Methodology Applied
Scientific EffectPressure gradient: Pressure Gradient

Data Source

PatentEP3745049B1Refrigeration apparatus
Publication Date: 2024.02.07 CARRIER CORP
  • EP3745049B1 patent drawingFigure 1

AI summary

This refrigeration apparatus (1) comprises a main refrigerant circuit (2) including a positive displacement compressor (4), a condenser (6), an expansion valve (8), an evaporator (10), through which a refrigerant circulates successively in a closed loop circulation, and a lubrication refrigerant line (18) in fluid connection with the main refrigerant circuit (2) and connected to the compressor (4) for lubrication of said compressor (4) with the refrigerant. The refrigeration apparatus (1) comprises a refrigerant container (20) connected between the condenser (6) and the expansion valve (8), said refrigerant container (20) being configured to retain a quantity of refrigerant, the lubrication refrigerant line (18) being connected to said refrigerant container (20). The refrigeration apparatus (1) further comprises heating means (28) for heating the refrigerant contained in the refrigerant container (20).