Adjustable Fail-Safe Suction Stop Valve for Refrigeration

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Existing solenoid valve systems in hot gas defrost applications for refrigeration may fail to open fully if the bleed valve does not function correctly, leading to unsafe pressure conditions due to uncontrolled release of high-pressure gas during the defrost cycle.

Innovation Solution

An adjustable fail-safe suction stop valve with dual pistons and check valves, where the valve opens partially only when a predetermined pressure is reached, ensuring controlled gas release through a solenoid assembly and adjustable spring tension check valves, preventing complete opening until safe pressure is achieved.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Stress or pressure

If a small bleed down solenoid valve is used to gradually bleed off pressure, then pressure control is improved, but the valve may fail to open or may not bleed down to a safe level, resulting in unreliable pressure equalization

Engineering Contradiction:

Improvepressure controlVSAvoidvalve opening reliability

Core Design Contradiction:

Stress or pressureVSReliability

Solution Approach 1:

The patent introduces a pilot valve as an intermediary component that controls the main valve opening. The pilot valve opens first to equalize pressure gradually, and only after pressure equalization is complete does the main valve open fully. This intermediary mechanism ensures reliable operation by separating the pressure control function from the main flow control function.

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent implements preliminary pressure equalization through the pilot valve before the main valve opens. The sequence is designed so that the pilot valve performs the pressure bleeding action first, and only after this preliminary action is complete does the main valve proceed to open for full flow. This preliminary action prevents the harmful effect of opening the main valve under unsafe pressure conditions.

Inventive Principle:

Principle #10Preliminary action

2Speed

If the suction stop valve opens fully immediately, then gas release speed is improved, but uncontrolled liquid propulsion and pressure surges occur, creating harmful effects

Engineering Contradiction:

Improvegas release speedVSAvoidvapor propelled liquid and pressure surges

Core Design Contradiction:

SpeedVSObject-generated harmful factors

Solution Approach 1:

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The patent segments the valve opening process into two distinct stages: first the pilot valve opens to equalize pressure gradually, then the main valve opens for full flow. This segmentation separates the pressure control function from the rapid gas release function, allowing each to perform optimally without interfering with the other.

Inventive Principle:

Principle #1Segmentation

3Reliability

If a dual piston system with check valves is used, then pressure equalization control and safety are improved, but device complexity increases

Engineering Contradiction:

Improvepressure equalization safetyVSAvoidvalve assembly structure

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The patent combines multiple functions into a single integrated valve assembly. The pilot valve, main valve, check valves, and spring mechanisms are merged into one compact unit rather than separate components. This merging reduces overall system complexity while maintaining the sophisticated pressure equalization and safety control functions.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The patent implements self-service through the automatic operation of check valves and spring-loaded mechanisms. The check valves automatically open and close based on pressure differential without external control, and the springs automatically reset the valve positions. This self-service operation reduces the need for external control systems and simplifies the overall device.

Inventive Principle:

Principle #25Self-service

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

Ensures controlled and safe pressure equalization in the evaporator coil by maintaining the valve in a partially open position until the pressure reaches a safe level, preventing uncontrolled gas release and ensuring system safety during the defrost cycle.

Implementation Method 1

the second check valve adapted to close when an inlet pressure to the second check valve falls below the tension of a spring of the second check valve

Methodology Applied

Scientific EffectPressure differential: Pressure Gradient

Implementation Method 2

the tension of a spring of the second check valve

Methodology Applied

Scientific EffectSpring tension: Spring

Implementation Method 3

a solenoid assembly operable to open and close a conduit connecting a source of pressurized gas

Methodology Applied

Scientific EffectSolenoid actuation: Solenoid

Data Source

PatentUS9145978B2Adjustable fail-safe suction stop valve

Publication Date: 2015.09.29 PARKER INTANGIBLES LLC

AI summary

An adjustable fail-safe suction stop valve is provided for providing hot gas defrost in refrigeration applications. The dual position valve (10) utilizes a single solenoid (20) and a pair of check valves (60,62) in a configuration that allows the evaporator pressure to be internally equalized through the valve to an adjustable setting over the suction pressure after a defrost cycle has occurred. The intermediate stage allows for this equalization to occur in a controlled manner without the need for an equalization valve.