Refrigerant Circuit Depressurization for Safe Burner Part Replacement
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Solution Overview
Problem
Existing methods for replacing components in refrigeration cycle apparatuses using flammable refrigerants lack safety measures to prevent ignition during the part replacement process, particularly when using a burner to remove and replace parts, as they do not effectively manage refrigerant concentration below the flammability limit.
Innovation Solution
A method involving a refrigerant recovery step, pressure reduction step, and part replacement step, where the pressure in the refrigerant circuit is reduced to a set pressure or until a set time is reached, ensuring the refrigerant concentration is below its flammability limit, allowing safe removal and replacement of parts using a burner.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If a burner is used to heat and remove parts during replacement, then part replacement can be performed efficiently, but the flammable refrigerant may ignite if its concentration exceeds the flammability limit
Solution Approach 1:
The patent applies preliminary action by reducing the refrigerant concentration in the refrigerant circuit before performing part replacement with a burner. The system recovers refrigerant into a storage container and introduces inert gas to dilute any remaining refrigerant, ensuring the concentration is below the flammability limit before heating operations begin. This preliminary preparation eliminates the ignition risk while allowing efficient part replacement to proceed.
2Object-affected harmful factors
If refrigerant is recovered into a storage container, then the refrigerant concentration in the circuit is reduced, but additional equipment and time are required for the recovery process
Solution Approach 1:
The storage container serves multiple functions: it stores recovered refrigerant for potential reuse, acts as a collection point during the recovery process, and functions as part of the overall refrigerant management system. This multi-functionality reduces the need for separate dedicated components for each function, thereby minimizing device complexity while effectively reducing refrigerant concentration in the circuit.
3Reliability
If the refrigerant concentration is reduced below the flammability limit, then safety is improved, but the replacement process requires additional steps for pressure reduction and time management
Solution Approach 1:
The system incorporates feedback mechanisms to monitor refrigerant concentration and pressure levels during the recovery and replacement process. The controller adjusts the recovery rate, inert gas introduction, and timing of part replacement based on real-time measurements, ensuring safety requirements are met while optimizing the process to avoid unnecessary delays or complexity.
4Object-affected harmful factors
If pressure reduction is performed to a set value or for a set time, then ignition is prevented, but the exact timing and pressure management becomes critical
Solution Approach 1:
Inert gas serves as an intermediary substance introduced into the refrigerant circuit during the replacement process. It dilutes the flammable refrigerant, displaces it toward the storage container, and creates a non-flammable atmosphere that allows safe burner operation. The inert gas acts as a buffer and mediator between the refrigerant and the ignition source, eliminating the need for extremely precise pressure and time control while maintaining safety.
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 method ensures safe part replacement by maintaining the refrigerant concentration below its flammability limit, preventing ignition and ensuring a safe operation during the replacement process.
Implementation Method 1
a pressure reduction step of connecting a pressure reducing device to the container connecting device to reduce a pressure in the refrigerant circuit through the container connecting device until the pressure in the refrigerant circuit reaches a set pressure or a setting time is reached
Implementation Method 2
a part replacement step of removing the part from the refrigerant circuit by heating to replace the part
Implementation Method 3
the refrigerant pipe and a pipe part of a device are heated using, for example, a burner
Data Source
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AI summary
To provide a safe refrigeration cycle apparatus which uses a flammable refrigerant and in which the flammable refrigerant is prevented from, for example, igniting with the flame of, for example, a burner during replacement of a component of the refrigeration cycle apparatus. Disclosed is a part replacement method for replacement of a part of a refrigeration cycle apparatus 100 including a refrigerant circuit in which a flammable refrigerant is circulated and a container connecting device 28 for controlling the refrigerant such that the refrigerant is allowed to flow out of the refrigerant circuit. The method includes a refrigerant recovery step of allowing the refrigerant to flow out of the refrigerant circuit through the container connecting device 28, a pressure reduction step of connecting a pressure reducing device 29B to the container connecting device to reduce a pressure in the refrigerant circuit until the pressure in the refrigerant circuit reaches a set pressure or a setting time is reached, and a part replacement step of removing the part from the refrigerant circuit by heating to replace the part.