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dehghan@hvac.ir
Jeffrey Mattocks, PE :
:
. . : )( : . . . : . : . )psig( . . psig : × ( × /) × ( . = ) Q=Q )N/N( : H=H )Q/Q( H=H )N/N( )( =Q : = H . =N : . . . . . . . . .
. . . : : . . . . . gpm . gpm gpm . . )( . . . . . . . . . . . . . .
. . . . . . . : NPSHA=HAHSHFHVPA
=NPSHA : . . =HA ( =HS ) =HF . . =HVPA . oF NPSHR . . NPSHR . NPSHR NPSHA
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. . . . . . HVAC . . .
gpm . . gpm . : . . . . . . . .
: John Zhang, Zhang, P.E. P.E. : John : :
. )dx( oF oF . . . )VAV( oF . . . . . . . . . . . cfm )VAV( cfm . . oF . cfm . Btuh cfm
)ho= Btu/lb( oF oF oF . )hm= Btu/lb( oF )( )hr( oF . Btu/lb Q Q=cfm )hrhs( : )hs( . cfm cfm Btuh : hs=hrQ/ cfm=/)/ = Btuh oF . . oF )hm= Btu/lb( oF oF )hc= Btu/lb( oF oF oF ( : .) QCW=4.5cfm(hm-hc)=4.5
7000(29.3-25)=135.450Btuh
: Qrh=1.1cfm(T1-Ts)=1.1
7000 (68-59)=69.300Btuh
)h= Btu/lb ( oF oF ( oF oF )hm= Btu/lb )x( . hs= Btu/lb : hs=xhm +)x(h2 )( )( . Btuh Btuh .
X=(hs-h2)/(hm-h2)=(27.2-22)/(29.3-22)=0.71
F . o
Qcw'=4.5cfm(1-X)(hm-h2)=4.57.000.3(29.3-22)=69.000 Btuh
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Edward Butts PE :
: Pumps & systems :
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: Career education :
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.)British . . . NORMA NORMA . . :PHAFF . . . . .
) . . )( . . . . . hn . . . standard institution ( BRITISH STANDARD
Hydronic Units and Radiators ) (
along the bottom of walls. 7. These types of radiators are fabricated from welded sheet metal sections and resemble freestanding cast-iron radiators. 9. This term is generally confined to sectional castiron column, large-tube, or small-tube units but also includes flat panel and sectional types as well. 10. This effect reflects the ability of the unit to direct its heat output to the occupied zone of a room. 11. When one of these is placed around a direct radiator, the airflow is restricted and the radiation output is diminished. 12. These types of radiators are fabricated of welded steel or extruded aluminum and are designed for installation in ceiling grids or floormounting. 16. This type of heating unit is made of aluminum and has no opening for air to pass over the wall side of the unit.
Answer
ACROSS 1. This is a heat distributing unit that operates with gravitycirculated air (natural convection). 5. Normal placement of a finned-tube heating unit is along this part of the building. 7. Finned-tube elements constructed of this material emit a larger portion of heat by radiation than do elements constructed of nonferrous materials. 8. This is the term used for the capacity of a convector, baseboard unit, or finned-tube unit that is extracted from the steam or water under standard testing conditions. 13. This type of baseboard unit has a heating element made of tubing, with fins concealed by a long sheet metal enclosure. 14. The type of heat transfer that takes place from a hydronic heat-distributing unit or radiator that is partly a function of the temperature difference between two surfaces and the distance between them. 15. This physical aspect of a terminal unit affects its heat-up and cool-down rates. 17. The effects of this factor on heat output of a hydronic heating unit varies depending on the material used and the portion of the unit's output that is radiant rather than convective (air density affects the convective portion of the heat transfer more than the radiant portion).
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18. The heat output of a finned-tube or baseboard element drops rapidly when this parameter of the fluid flow drops below 0.5 fps because the flow changes from turbulent to laminar at around 0.1 fps. 19. These types of radiators consist of supply and return headers with interconnecting parallel steel tubes and can be specialty shaped to coincide with the building structure. 20. The type and color of this on a radiator or castiron baseboard can have a net effect of reducing the total heat output by 10% or more.
DOWN 1. The form of heat transfer that takes place by the transfer of heat from a surface to the air surrounding hydronic heat-distributing units and radiators. 2. By definition, 240 Btuh = 1 ft2 of this unit of measure. 3. When this parameter of the fluid in a convector or radiator gets too low, the heat distributing equipment needs to be oversize or additional heat distributing units need to be installed to compensate for the capacity loss. 4. These types of radiators consist of flat surfaces with or without exposed extended fin surfaces attached to the rear for increased output. 6. This type of radiation heating unit is designed for installation
David W. Spitzer :
:
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Warren L. Beeton and Hung M. Pham :
: ASHRAE Journal :
. HFC . HFC HCFC
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. LOT . SIT TD )LIT( . . SChx=LITLOT )SChx( )VOT( . TXVi )SH ( )Superheat( Qhx=Me)HlitHlot( )( . )Mi( . . )/ oC( oF oF . . . . o F )( . TXVi . oF
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. )SIT( )Tevap( ) Tcond( . ) ( R-404A EER ARI . )/ oF( )/ oF( ( .)EER )EER ( . ARI . oF )( oF oF . . . : . ) ( . )( . )( TXVi . ) ( .
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) ( . . )/ oC( oF . . . . HFC HFC R-404A . . R-502 )GWP( . R22 EER Ra . . RA RC R22 ) oC( oF . HFC RA GWP . RA RA . RA GWP . R22 RA . . RA )( RA RA HFC EER .
. . . HFC . 1-VaporInjectedScroll- Compressor 2-interstage cooling 3- -HighStage 4- Subcooler 5- refrigeration effect 6- LowStage 7- required c0mpressor displacement 8- economizer 9-Flooded Evaporator 10-glide 11- modulation 12- pumpdown cycling control References 1. Stoecker, W. F. and J. W. Jones. 1982. Refrigeration and Air Conditioning. New York: McGraw Hill, Chapter 16, pp. 308– 324. 2. Favrat, D., F. Brand, and M. Zehnder. 2000. “Pompe a chaleur haute temperature.” Ecole Polytechnique Federale De Lausanne, Final Report, June. 3. Diab, A., R. Tariq and J. Gephart. 1990. “Compressor for low temperature applications of R- 22.” Revue Int. Froid technolo-gies 14( 1). 4. Andrews J. W., T. A. Butcher, and W. G. Wilhelm. 1989. “Test on a supercharged compressor for commercial refrigeration.” results ASHRAE Transactions 95( 2). 5. Domanski, P. A. 1995. “Theoretical evaluation of the vapor cycle with a liquid- line/ suction- line heat exchanger, com-pression and ejector.” NIST, Report 5606. econo-mizer,ASHRAE Journal
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Mike Sirotnak :
:
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( . ) . . : . . . . . . ) ( C ) ( . . ) ( : ( :) ( ) oF ( :) ( ) oF ( :) ( ) oF . ) oF ( . . . . . : . . .
. . . . . ( . . ) . . . . . . . References Maurice Orfeuil, Electric Process Heating, Battelle Press 1987. J. R. O’Connell, E. F. B. Croft, W. C. Hankins, Electric Infra- red Heating for Industrial Processes, EA Technology, 1990. Technology Guidebook for Electric Infrared Process Heating, CMF Report No. 93- 2, 1993. Jay Siedenburg, Heating Technologies for Thermoforming, CMF Report No. 95- 1, 1995. Shelby F. Thames, Ph. D., Presentation on the Use of infrared with Polymer Applications, Infrared Equipment Association (IREA) annual meeting, 1997. Thomas A. Stryker, Heat Processing Handbook for Paint & Powder Applications, 1997. Philips Lighting Application Information, 1994.
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: . : . . . : . . . . . . . . )( . . . ( . ) . . . .
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Patrick L.Whitworth, CPD, and Anthony W. Stutes, PE, CPS : Plumbing Systems & Design :
. ( : ( ) ( ) .) . . . ) ( . ) ( . ) ( . . ) nl/min( scfm . ) oC( oF . . : ) ) . ) ) ) ) ) ) : : ) . ( ) ) . ) . )
( ) . : . ) )L/min cfm ( . . ) ) . ) .L/min cfm ) . . ) . ) . . . . . . . . . . . . . . .
) ( . . . . . . . . References 1. Compressed air data. Compressed Air Magazine. 2. Compressed air handbook . McGrawHill. 3. Compressed Gas Association. Compressed air and gas handbook . 4th ed. 4. Frankel, M. 1986. Compressed air design for industrial plants. Plumbing Engineer Sept. - Oct. 5. Frankel, M. 1996. Facility piping systems handbook. New York: McGraw- Hill. 6. Ingersoll- Rand. Compressed air fundamentals.
. ) . . . . HVAC . . . . . .
Samuel C. Monger :
:
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. . : . . ( ) . . )VAV( )CAV( . )(
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. . CAV VAV . . VAV CAV . . .
. . . . . . . . . VAV . . . CAV VAV . . CAV . . . . . . . . .
. . . . . .
David Jaber, Jaber, Gilbert Gilbert A. A. McCoy McCoy & & Fred Fred L. L. Hart Hart : : David David Jaber, Gilbert A. McCoy & Fred L. Hart :
: : : : CEP : CEP CEP :
. . . . . )DOE( . . . . . psig . . psig . psig . . . . . psig psig . .
. ( . ) . . . . . . . . . . . . ( . ) ( psig .) Btu/h . ( oF oF oF .) .
. . . . .
. . . . . . . . . . . . . E+ . . . . . oF .
. . . . . .
. . MMBtu . . . . . . . : ) . ) . ) . . 1- reflux 2- reboiler 3- Online oxygen analyzer 4- blowdown 5- ASME International 6- economizer 7- flash tank
. . E+ . . NOx SOx . . .) ( . . . . . . . . ) (
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Mike Fleming :
:
.)Corona Suppression( . . . . DC . . . ( ) . . . . . . . . . . . . .
. . . HCFC CFC . ( . ) . . . : ) ( ( . ) . . . . . )Heated Diode( :
. . . . . . . . . . . . . . . . . .
. . . . . . . ! . . . . ) ( . . . . . . .
John Siegenthaler, PE :
:
. . . . )( . .
. . . . PEXALPEX PEX
)( ) ( . B&G . . / . . . . . ) ( . . . . . . . . .
. PEXALPEX PEX . PEXALPEX PEX . PEXALPEX PEX . . A B C CPVC . PEXALPEX / . . . PEXALPEX . . .
. . . .
: . . . .
. . . . . . ) oF ( . . . . . . . . . . . 1- Actuator 2- Throttling
. . ) ( . . . oF
CFD H. Kotani, T. Yamanaka & Y.Momoi :
:
)(
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)( CFD . z x y . . k CFD . . CFD . CFD . . . . )( Nielsen . )CFD( )( Gosman )( )( Nielsen . . IEA annex 20 ) ( Chen Srebric ASHRAE . . Okaichi . )( )( . CFD . . . )( Kondo .
)(
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)(
CFD )(
) ( . . . . . . . . )( . )( Chen Srebric )( Nieslen . )( . Nielsen )( x=/ cm z=cm ( . )( x=cm . . )( . . CFD CFD )( . k
. )( CFD . CFD CFD . . . z x y . CFD . . k . )( . . y . )( z x . . Hz .
. . CFD . . CFD . . . . . CFD . .
CFD )(
. . CFD CFD . . References Gosman, A. D. , P. V. Nielsen, A. Restivo, and J. H. Whitelaw, 1980. The flow properties of rooms with small ventilation openings, Transactions of ASME , Vol. 102: 316- 323. Hirano, T. , R. Sato, T. Yamanaka, H. Kotani, and K. Miyamoto. 1997. Measurement of the airflow velocity and turbulent energy around anemostat type diffuser to patch onto CFD. Proc. Technical Meeting of SHASE- Japan : 509- 512 ( in Japanese ) . Kondo Y. , Y. Nagasawa, T. Moriya, M. Sekiguchi, and K. Harimoto. 2001. Modeling of complex ceiling diffuser in CFD - part 1 and part 2. Proc. Technical Meeting of SHASE- Japan : 717- 724 ( in Japanese ) . Nielsen, P. V. , A. Restivo and J. H. Whitelaw. 1978. The velocity characteristics of ventilated rooms, Journal of Fluid Engineering , Vol. 100: 291- 298. Nielsen, P. V. 1992. Description of supply openings in numerical models for room air distribution, ASHRAE Transactions , Vol. 98( 1) : 963- 971. Okaichi A. , T. Yamanaka, H. Kotani, and M. Kato. 2000. Study on CFD of rooms with anemostat type diffuser- part 2. Proc. Technical Meeting of kinki branch of AIJ- Japan : 245- 248 ( in Japanese ) . Okaichi A. , T. Yamanaka, H. Kotani, and Y. Momoi. 2001. CFD of airflow in room with complex shaped diffuser - part2. Proc. Technical Meeting of kinki branch of SHASE- Japan : 133- 136 ( in Japanese ) . Software Cradle Co. Ltd. 2000. STREAM for Windows Version 4 User Guide, Osaka. Srebric, J. , Q. Chen. 2001. A method of test to obtain diffuser data for CFD modeling of room airflow, ASHRAE Trans. , vol. 107( 2) : 108- 116.
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M.I.3
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