Liquid-to-Harvest Line Bypass for Low-Charge Refrigerant Flow

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Conventional refrigerant systems with low charge amounts face challenges in maintaining refrigerant mass flow and suction pressure during the harvest mode, leading to reduced efficiency in warming the evaporator and harvesting ice, especially with hydrocarbon refrigerants where charge limits necessitate smaller system volumes and shorter liquid lines.

Innovation Solution

A refrigerant system with a conduit assembly connecting the liquid line to the harvest line, featuring a check valve that allows refrigerant flow from the liquid line to the harvest line when the pressure differential exceeds a certain threshold, ensuring increased refrigerant mass flow and suction pressure during the harvest mode.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Quantity of substance

If the liquid line is shortened to reduce refrigerant charge amount, then the refrigerant charge amount is reduced, but the refrigerant mass flow during harvest mode is insufficient

Engineering Contradiction:

Improverefrigerant charge amountVSAvoidrefrigerant mass flow during harvest

Core Design Contradiction:

Quantity of substanceVSProductivity

Solution Approach 1:

The liquid line to harvest line bypass conduit allows refrigerant to be pre-positioned in the liquid line during freeze mode, so that when harvest mode begins, the refrigerant is already in place and can immediately flow through the harvest line, eliminating the delay that would occur with a shorter liquid line

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The bypass conduit acts as an intermediary pathway that connects the liquid line to the harvest line, allowing refrigerant to transfer between these lines through a controlled route with a check valve, enabling mass flow without requiring a longer liquid line

Inventive Principle:

Principle #24Intermediary (Mediator)

2Quantity of substance

If the liquid line is shortened to reduce refrigerant charge amount, then the refrigerant charge amount is reduced, but the suction pressure during harvest mode decreases

Engineering Contradiction:

Improverefrigerant charge amountVSAvoidsuction pressure during harvest

Core Design Contradiction:

Quantity of substanceVSStress or pressure

Solution Approach 1:

Refrigerant is pre-positioned in the liquid line during freeze mode through the bypass conduit, ensuring that when harvest mode starts, sufficient refrigerant is already available to maintain proper suction pressure in the evaporator without requiring a larger overall charge

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The bypass conduit with check valve serves as an intermediary that enables refrigerant to flow from the liquid line to the harvest line, maintaining the pressure differential needed to sustain suction pressure during harvest operation

Inventive Principle:

Principle #24Intermediary (Mediator)

3Volume of moving object

If the liquid line is shortened to reduce system volume, then the system volume is reduced, but the ice harvest time increases

Engineering Contradiction:

Improvesystem volumeVSAvoidice harvest time

Core Design Contradiction:

Volume of moving objectVSLoss of time

Solution Approach 1:

The bypass conduit enables refrigerant to be pre-positioned in the liquid line during freeze mode, so that when harvest mode begins, the refrigerant is already in place and can immediately begin the warming process, reducing ice harvest time despite the shorter liquid line

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The bypass conduit acts as an intermediary pathway that accelerates the refrigerant delivery to the evaporator during harvest mode, compensating for the reduced system volume by providing a direct flow path

Inventive Principle:

Principle #24Intermediary (Mediator)

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 enhances refrigerant mass flow and suction pressure, resulting in quicker ice harvest times and improved performance across a wider temperature range, comparable to systems with higher hydrofluorocarbon refrigerant charges, while maintaining cost-effectiveness and reducing the need for additional refrigerant storage vessels.

Implementation Method 1

Methodology Applied

Scientific EffectPressure differential: Pressure Gradient

Data Source

PatentUS10107540B2Refrigerant system with liquid line to harvest line bypass

Publication Date: 2018.10.23 PENTAIR FLOW SERVICES AG

AI summary

A refrigerant system includes a compressor connected to a first valve forming a harvest line, a condenser connected to the compressor by a first segment of conduit and an expansion device by a second segment of conduit with the condenser and the second segment of conduit forming a liquid line. A third segment of conduit is connected to the liquid line and the harvest line with the third segment of conduit having a second valve. The second valve allows flow of refrigerant from the liquid line to the harvest line through the third segment of conduit in an open position and the second valve blocking flow of the refrigerant from the liquid line to the harvest line through the third segment of conduit in a closed position.