Air purge device
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Solution Overview
Problem
Existing gas separation films in air purge devices either allow permeation of refrigerant gas along with uncondensable gas or fail to efficiently discharge uncondensable gas, leading to heat transfer inhibition and inefficiencies in refrigerant condensation.
Innovation Solution
An air purge device with a separation film, vacuum pump, and control unit that selectively separates and discharges uncondensable gas while minimizing refrigerant leakage by managing pressure differences and valve operations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If a gas separation film that is much permeable to uncondensable gas is used, then uncondensable gas can be discharged efficiently, but refrigerant gas also permeates along with it causing leakage
Solution Approach 1:
The patent implements periodic action by alternating between a first operation mode (discharge mode) and a second operation mode (refrigerant recovery mode). In the first mode, the discharge valve is open and vacuum pump operates to discharge uncondensable gas efficiently. In the second mode, the discharge valve is closed and vacuum pump recovers refrigerant gas. This periodic switching resolves the contradiction by achieving high discharge efficiency when needed while preventing refrigerant leakage during recovery phases.
Solution Approach 2:
The patent applies parameter changes by dynamically adjusting the operating parameters of the vacuum pump and valve states based on system conditions. The control unit monitors refrigerant temperature, pressure, and flow rate to determine when to switch between discharge and recovery modes, optimizing the balance between uncondensable gas removal and refrigerant conservation.
2Loss of substance
If a gas separation film that is extremely impermeable to refrigerant gas is used, then refrigerant leakage is suppressed, but uncondensable gas discharge becomes insufficient
Solution Approach 1:
The periodic operation mode switching enables the system to use an impermeable film for refrigerant conservation while still achieving adequate uncondensable gas discharge. During the discharge phase, the vacuum pump operates at high capacity to remove accumulated uncondensable gas, compensating for the film's low permeability.
Solution Approach 2:
The patent effectively creates a dual-function system where the same separation film serves two opposing purposes: blocking refrigerant while allowing periodic uncondensable gas removal. The control system copies the function of a permeable film through operational timing, achieving both protection and discharge capabilities.
3Productivity
If the partial pressure of uncondensable gas is increased to improve discharge, then heat transfer inhibition increases reducing condensation performance
Solution Approach 1:
The patent applies preliminary action by continuously operating the vacuum pump in a standby recovery mode to maintain low uncondensable gas partial pressure in the refrigerant circuit before significant accumulation occurs. This prevents heat transfer inhibition from developing, while the periodic discharge mode removes accumulated gas before it reaches harmful concentrations.
Solution Approach 2:
The control unit uses feedback from temperature and pressure sensors to monitor heat transfer performance and uncondensable gas concentration. When sensors detect conditions indicating excessive uncondensable gas accumulation (such as increased terminal temperature difference), the control unit triggers the discharge mode to restore optimal heat transfer conditions.
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 discharges uncondensable gas while suppressing refrigerant leakage, maintaining condensation performance, and reducing heat transfer inhibition.
Implementation Method 1
a separation film provided to the air purge pipe and configured to separate, by a pressure difference, an uncondensable gas from the mixed gas extracted by the air purge pipe
Implementation Method 2
there are several types of gas separation films such as, for example, those characterized in being much permeable to an uncondensable gas but also permeable to a certain amount of a refrigerant gas
Implementation Method 3
a vacuum pump provided downstream of the first valve in the exhaust pipe and configured to externally discharge a gas present inside the exhaust pipe
Data Source
AI summary
An a purge device that includes an air purge pipe connected to a condenser and configured to extract a mixed gas containing a refrigerant gas and air from the condenser; a separation film provided to the air purge pipe and configured to separate, by a pressure difference, air from the mixed gas extracted by the air purge pipe; an exhaust pipe configured to externally guide a gas containing air separated by the separation film; a first valve provided to the exhaust pipe; a vacuum pump provided downstream of the first valve in the exhaust pipe and configured to externally discharge a gas present inside the exhaust pipe; and a control unit, the control unit activates the vacuum pump, opens the first valve, then closes the first valve to stop permeation of air caused by a pressure difference when detecting that a predetermined amount of air has permeated the separation film.