Refrigerant system operation sequences for leak prevention

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Refrigerant leaks in refrigeration systems used for transportation can pose hazards if the concentration exceeds threshold levels within conditioned spaces, and existing systems lack efficient methods for controlled shutdown and defrosting processes.

Innovation Solution

A method involving a refrigeration system control process that initiates shutdown or defrosting by closing specific valves within the refrigerant circuit, detecting suction pressure, and stopping the compressor when it falls below a threshold, with user input options and graphical interfaces for initiating these processes.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If the refrigeration system shuts down by simply stopping the compressor, then the operation is simple and quick, but refrigerant may leak into the conditioned space creating safety hazards

Engineering Contradiction:

Improveshutdown simplicityVSAvoidrefrigerant leak hazard

Core Design Contradiction:

Ease of operationVSObject-affected harmful factors

Solution Approach 1:

The system performs preliminary actions before shutdown by closing the first valve (between condenser and evaporator) and the second valve (between compressor and condenser) to isolate the refrigerant circuit, then evacuating refrigerant from the evaporator using the compressor before stopping it. This preliminary isolation and evacuation prevents refrigerant leakage into the conditioned space during shutdown.

Inventive Principle:

Principle #10Preliminary action

2Object-affected harmful factors

If the refrigeration system performs a complete shutdown procedure with valve closing and refrigerant evacuation, then refrigerant leak prevention is improved, but the shutdown time and process complexity increase

Engineering Contradiction:

Improverefrigerant leak preventionVSAvoidshutdown duration

Core Design Contradiction:

Object-affected harmful factorsVSLoss of time

Solution Approach 1:

The system closes valves and evacuates refrigerant before shutdown to prevent leaks, accepting the time cost for safety.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The system uses suction pressure detection as feedback to determine when refrigerant evacuation is complete. The compressor continues running until suction pressure drops below a threshold, providing automatic termination criteria that optimizes shutdown time while ensuring complete refrigerant evacuation and leak prevention.

Inventive Principle:

Principle #23Feedback

3Device complexity

If the refrigeration system uses standard shutdown procedures without pressure monitoring, then the control process is simple, but refrigerant may remain in the evaporator and leak into the conditioned space

Engineering Contradiction:

Improvecontrol process complexityVSAvoidrefrigerant accumulation in conditioned space

Core Design Contradiction:

Device complexityVSObject-affected harmful factors

Solution Approach 1:

The system incorporates suction pressure detection as feedback to monitor refrigerant evacuation progress. The controller compares detected suction pressure against a threshold to determine when evacuation is complete, ensuring refrigerant is fully removed from the evaporator before shutdown. This feedback mechanism prevents refrigerant accumulation in the conditioned space while maintaining reasonable control complexity.

Inventive Principle:

Principle #23Feedback

4Reliability

If the refrigeration system performs defrosting with valve closing and compressor operation, then defrosting effectiveness is improved, but energy consumption increases

Engineering Contradiction:

Improvedefrosting effectivenessVSAvoidcompressor energy consumption

Core Design Contradiction:

ReliabilityVSUse of energy by moving object

Solution Approach 1:

The system uses suction pressure detection as feedback to control defrosting duration and intensity. The compressor operates during defrosting to heat the evaporator, and the process is monitored until suction pressure indicates adequate defrosting, preventing excessive energy consumption while ensuring effective defrosting.

Inventive Principle:

Principle #23Feedback

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

Effectively manages refrigerant flow to prevent leaks and maintain safe conditions during shutdown and defrosting, ensuring the refrigeration system operates within safe parameters and reduces the risk of refrigerant accumulation in the conditioned space.

Implementation Method 1

operating a compressor within the refrigerant circuit

Methodology Applied

Scientific EffectCompression: Compression

Implementation Method 2

the refrigeration unit uses a refrigeration cycle to cool the air

Methodology Applied

Scientific EffectRefrigeration cycle:

Data Source

PatentUS11885543B2Refrigerant system operation sequences for leak prevention

Publication Date: 2024.01.30 CARRIER CORP

AI summary

A method of shutting down a refrigeration system including: initiating a shutdown process of the refrigeration system; closing a first valve within a refrigerant circuit of the refrigeration system; operating a compressor within the refrigerant circuit; detecting a suction pressure within the refrigerant circuit; closing a second valve within the refrigerant circuit of the refrigeration system when the suction pressure is below a threshold suction pressure; and stopping operation of the compressor.