Refrigerant charging method, heat source unit, and renewed refrigeration cycle apparatus
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Solution Overview
Problem
During the transport and installation of outdoor units in refrigeration cycle apparatuses, foreign materials and moisture can enter the heat source unit, compromising its integrity and requiring additional handling and maintenance steps to prevent contamination.
Innovation Solution
A refrigerant charging method where a first refrigerant is pre-charged in the heat source unit before connection to the utilization unit, with a second refrigerant added later, ensuring the first refrigerant maintains an absolute pressure greater than or equal to atmospheric pressure to prevent external air and contaminants from entering, and utilizing R32 and R410A refrigerants to streamline the process without the need for extraction or new connection pipes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If the heat source unit is transported to the installation location, then the refrigeration cycle apparatus can be installed, but foreign materials and moisture may enter the heat source unit
Solution Approach 1:
The first refrigerant is charged into the heat source unit before transport and connection to the utilization unit. This preliminary charging creates a positive pressure environment that prevents outside air, foreign materials, and moisture from entering the heat source unit during transport and installation operations.
Solution Approach 2:
The first refrigerant (R32) creates an inert atmosphere inside the heat source unit, replacing the air environment that would otherwise allow foreign materials and moisture to enter. This inert environment protects the system during the vulnerable transport and installation phases.
2Object-affected harmful factors
If the first refrigerant is charged to prevent outside air entry, then contamination is avoided, but the system requires additional refrigerant types
Solution Approach 1:
The method merges the protective function (preventing contamination) with the operational function (refrigeration cycle). The first refrigerant R32 serves dual purposes: it creates positive pressure to prevent outside air entry during transport, and it also functions as part of the final refrigerant mixture (R32+R410A) for the refrigeration cycle, eliminating the need for separate protective gases.
Solution Approach 2:
The first refrigerant R32 performs multiple functions: (1) it prevents outside air and contaminants from entering during transport by maintaining positive pressure, (2) it serves as the base refrigerant for the final refrigeration system, and (3) it can be mixed with R410A to create the operational refrigerant mixture. This multi-functionality simplifies the overall system complexity.
3Productivity
If R32 and R410A refrigerants are used, then the process is streamlined without extraction or new pipes, but pressure control must be maintained
Solution Approach 1:
The method utilizes specific pressure parameters for the first refrigerant R32 (absolute pressure ≥ atmospheric pressure at 20°C, and <1 MPa at 35°C) to achieve optimal protection against outside air entry while ensuring safe and efficient mixing with R410A. These parameter specifications balance contamination prevention with operational safety and efficiency.
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 effectively prevents foreign materials and moisture from entering the heat source unit during transport and installation, saving time and labor by allowing the use of pre-charged refrigerants and reutilized refrigerants, while ensuring the system operates within safe and compatible pressure ranges.
Implementation Method 1
the first refrigerant charged in the heat source unit has an absolute pressure that is more than or equal to an atmospheric pressure at 20° C. in the heat source unit
Data Source
AI summary
There is provided a refrigerant charging method in which a foreign material and moisture are avoided from entering a heat source unit until a refrigeration cycle apparatus is configured. The refrigerant charging method is a method of charging a refrigerant to a refrigerant circuit in which a refrigeration cycle is to be performed by a circulating refrigerant, the refrigerant circuit being configured by connecting a second heat source unit and a utilization unit to each other. The refrigerant charging method includes charging a first refrigerant to the second heat source unit before connecting the second heat source unit to the utilization unit to configure the refrigerant circuit, and connecting the second heat source unit to the utilization unit and charging a second refrigerant that differs from the first refrigerant to the refrigerant circuit to obtain the circulating refrigerant that includes the second refrigerant and the first refrigerant that is charged in the second heat source unit.