Part replacement method for refrigeration cycle device
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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 replacement process, particularly when the refrigerant concentration exceeds its flammability limit, leading to potential safety hazards.
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 below the lower flammability limit, ensuring the refrigerant concentration is safe for removal and replacement without ignition, using a pressure reducing device and a burner for heating.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If a burner is used to heat the refrigerant pipe for part replacement, then the brazing material can be melted and the part can be removed and replaced, but the flammable refrigerant may ignite if its concentration exceeds the flammability limit
Solution Approach 1:
The patent applies preliminary action by recovering the refrigerant from the refrigerant pipe before heating with a burner. The refrigerant recovery step is performed in advance to reduce the refrigerant concentration below the flammability limit, thereby eliminating the ignition risk that would otherwise occur during the subsequent heating and brazing operations
Solution Approach 2:
The patent applies parameter changes by controlling the refrigerant concentration parameter to be below the flammability limit. By monitoring and adjusting the refrigerant concentration through recovery operations before heating, the system maintains safe operating parameters that prevent ignition while still allowing the brazing process to proceed
2Object-affected harmful factors
If the refrigerant is recovered completely before part replacement, then the safety risk is reduced, but the time required for part replacement increases
Solution Approach 1:
The patent applies partial action by recovering only enough refrigerant to reduce the concentration below the flammability limit, rather than requiring complete recovery. This partial recovery approach is sufficient to eliminate the ignition risk while minimizing the time required, avoiding the need for exhaustive recovery operations
3Object-affected harmful factors
If the refrigerant concentration is reduced below the flammability limit, then ignition is prevented, but the pressure in the refrigerant circuit must be reduced which requires additional time
Solution Approach 1:
The patent applies mechanics substitution by using a vacuum pump to rapidly reduce the pressure in the refrigerant circuit. The vacuum pump creates a pressure differential that accelerates refrigerant removal and concentration reduction, replacing slower natural pressure equalization methods and significantly reducing the time required to reach safe concentrations
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 removal and replacement of components by maintaining the refrigerant concentration below its flammability limit, preventing ignition and enhancing safety during the process.
Implementation Method 1
a pressure reducing device is connected to a container connecting device, and a pressure in a refrigerant circuit is reduced through the container connecting device by the pressure reducing device
Implementation Method 2
the refrigerant pipe is heated using, for example, a burner and are fixed (connected) with a brazing material
Implementation Method 3
the brazing material can be melted and the refrigerant pipe can be removed and replaced
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.