Trane TRG-TRC004-EN manual Compressor in a System, Vwhp/Hyho&Rqwuro, System-Level Control

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period three

The Compressor in a System

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Period Two presented several methods used to control the capacity of a compressor. This next section considers the entire system in order to determine how the capacity of the compressor is controlled to maintain desired space conditions.

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System-Level Control

The method of controlling compressor capacity to maintain desired space conditions depends on 1) whether the system is a chilled-water or a direct- expansion system, and 2) how the airside system responds to changes in space loads.

Generally, in air-conditioning applications, compressors will be applied in either

achilled-water or a direct-expansion (DX) system. A chilled-water system uses water as the cooling media. The refrigerant inside the evaporator absorbs heat from the water, and this water is pumped to coils in order to absorb heat

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TRG-TRC004-EN

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Contents Air Conditioning Clinic Refrigeration Compressors Business Reply Mail One of the Fundamental Series Comment CardRefrigeration Compressors 5HIULJHUDWLRQ&RPSUHVVRUV PrefaceContents TRG-TRC004-EN 9DSRU&RPSUHVVLRQ5HIULJHUDWLRQ Introduction5HIULJHUDWLRQ&\FOH RPSUHVVRU7\SHV Compressor TypesReciprocating Compressor 5HFLSURFDWLQJ&RPSUHVVRUFrpsuhvvlrq Vwurnh Rshqlqj Glvfkdujh Slvwrq Scroll Compressor 6FUROO&RPSUHVVRUMrxuqdo Lqwdnh Skdvh Frpsuhvvlrq Glvfkdujh Helical-Rotary Screw Compressor +HOLFDO5RWDU\6FUHZ&RPSUHVVRU+HOLFDO5RWDU\&RPSUHVVRU Phvklqjsrlqw Centrifugal Compressor HQWULIXJDO&RPSUHVVRUYroxwh Gliixvhu Sdvvdjhv Udgldo Lpshoohu Eodghv Uhiuljhudqw 2SHQ&RPSUHVVRU 6HPLKHUPHWLF&RPSUHVVRU +HUPHWLF&RPSUHVVRU0HWKRGVRI&RPSUHVVRU8QORDGLQJ Compressor Capacity ControlCylinder Unloaders \OLQGHU8QORDGHUVXqordghufrqwuroohu Vrohqrlgydoyh Ydoyh DSDFLW\9HUVXV6XFWLRQ7HPSHUDWXUH RPSUHVVRU8QORDGLQJ $OWHUQDWLQJ&\OLQGHUV2QDQG2II \FOLQJ6FUROO&RPSUHVVRUV \FOLQJ2QDQG2IICycling On and Off \FOLQJ6FUROO&RPSUHVVRUV Slide Valve 6OLGH9DOYHInlet Vanes QOHW9DQHVInlet vanes presented in this section of the clinic Variable Speed 9DULDEOH6SHHG\VWHP/HYHO&RQWURO Compressor in a SystemSystem-Level Control RQVWDQW9ROXPH6\VWHP KLOOHGDWHU6\VWHP 9DULDEOH$LU9ROXPH6\VWHPPreventing Evaporator Freeze-Up 6HQVLQJ6XFWLRQ7HPSHUDWXUH +RW*DV%\SDVVWRYDSRUDWRU,QOHW +RW*DV%\SDVVWR6XFWLRQ/LQH System Components clinic 5HYLHZ²3HULRG2QH Review5HYLHZ²3HULRG7ZR \VWHPOHYHOFRQWURO 5HYLHZ²3HULRG7KUHHFor more information, refer to the following references TRG-TRC004-EN Questions for Period QuizAnswers Glossary Glossary Glossary Trane Company