Trane trg-trc005-en manual Thermostatic Expansion Valve, TXV Control

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period four

Expansion Devices

notes

Thermostatic Expansion Valve

thermostatic expansion valve (TXV)

evaporator	liquid
	refrigerant

liquid/vapor mixture

A

refrigerant vapor

Figure 40

In addition to maintaining a pressure difference, the thermostatic expansion valve controls the quantity of liquid refrigerant entering the evaporator. It ensures that the refrigerant will be completely vaporized within the evaporator (A) and maintains the proper amount of superheat in the system.

TXV Control

	liquid
	liquid/vapor refrigerant
A	mixture
A
	refrigerant
	vapor

Figure 41

If not enough liquid refrigerant enters the evaporator, it vaporizes too quickly (A). As a result, the remaining coil tubes fill with vapor, producing very little refrigeration effect.

TRG-TRC005-EN

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Contents

Air Conditioning Clinic Refrigeration System Components Comment Card One of the Fundamental SeriesBusiness Reply Mail Refrigeration System Components Preface Refrigeration System ComponentsContents TRG-TRC005-EN Introduction Vapor-Compression RefrigerationRefrigeration Cycle Refrigeration CyclePeriod one Condenser Air-Cooled Condenser CondensersAir-Cooled Condensers Effect of Subcooling Evaporative Condenser Centrifugal Fan Air-Cooled CondenserEvaporative Condensers Water-Cooled Condenser Water-Cooled CondensersCooling Tower Condenser Capacity Condenser ControlCondenser Control Condensing Temperature Control Vary Entering Water Temperature Vary Condenser Water Flow RateCooling Tower Bypass Air-Cooled Condenser Control Condenser Flooding ControlCondensers Finned-Tube Evaporator EvaporatorsFinned-Tube Evaporators Turbulent Flow Superheat Shell-and-Tube Evaporator Shell-and-Tube EvaporatorsEvaporator Control Evaporator ControlFinned-Tube Evaporator Control Face-Split Arrangement80ºF Intertwined Arrangement Row-Split Arrangement Shell-and-Tube Evaporator Control Expansion Devices Expansion DeviceThermostatic Expansion Valve TXV ControlTXV TXV TXV Operation Psia TXV Superheat Setting Too much superheatSolenoid Valve AccessoriesSolenoid Valve Period five Liquid-Line Filter Drier Liquid-Line Filter DrierSealed type Moisture-Indicating Sight Glass Moisture-Indicating Sight GlassSuction Line Filter Suction Line FilterHot Gas Muffler Hot Gas MufflerShutoff Valve Shutoff ValveAccess Port Access PortReview Review-Period OneReview-Period Two Air-cooled condenserReview-Period Three Review-Period FourReview-Period Five For more information, refer to the following references Quiz Questions for PeriodQuiz Answers To C To GGlossary Glossary Glossary Trane Company