壓縮空氣系統節能管理技術 - asip.org.t · 節能不漏氣省電不客氣威鐘黃茂興 © Weibell Copy Right 壓縮空氣系統節能管理技術主講人威鐘企業黃茂興

Weibell Copy Right

2009/09/01

2 Weibell Copy Right


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. CDA

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. ESCO


Costs for compressed air

Compressed air is an expensive energy source because first you must transform electrical energy to mechanical energy and then the mechanical energy is transformed to pneumatic energy.(, , )

Investment 19% ( 19%)Maintenance 7% ( 7%)Energy 73% ( 73%)Cooling water 1% ( 1%)

1


Costs for compressed air

The cost of producing 1Nm compressed air at 5 bars is approximately 2 cent (USD).(1Nm5bars, USD$0.02/Nm , 2/NTD 0.40/Nm)Leakage accounts for 10-15 % of the compressed air produced.Less than 50% of the compressed air produced is used to create motions, e.g. cylinders and motors.(10-15%, 50%, )

2


Power cost for compressed air

Example CalculationsThe following example represents a typical small job-shop manufacturer.A facility operates a 100 hp air compressor 8,000 hours annually. It runs fully loaded, at 94.5 percent efficiency, 85 percent of the time. It runs unloadedat 25 percent of full loadat 90 percent efficiency, 15 percent of the time. The electric rate is NTD2.0 per kWh, including energy and demand costs. The cost per year to power the air compressor will be as follows.Fully loaded (/) =100 hp x 0.746 x 8,000 hr x NTD2.0/kWh x 0.85 x 1.00.945=NTD1,073,608Unloaded (/) =100 hp x 0.746 x 8,000 hr x NTD2.0/kWh x 0.15 x 0.250.90=NTD49,733The total annual energy cost to operate the air compressor is NTD1,123,341/


0.7MPa0.1416M3 0.007MPa0.5

HP2545BTU/(1BTU = 1.055KJ)

GPM() , T= 11.1(),HP/4 T= 22.2 () HP/8

HP 2545 500T


CDA

1 2 3 4 5 6 7 8 9 10

1.7/(0.3/M3 for CDA)


MultiMulti--StageStage

High Efficiency, Wider RangeHigh Efficiency, Wider Range

History

Axial Mixed

Why Centrifugal ?Why Centrifugal ?-- Low CostLow Cost-- High PressureHigh Pressure-- Short LengthShort Length


P- F

10~20(Surge) 60 (Stonewall)


IGVInlet Guide Vane vs. Butterfly ValveAn IGV offers about 3.5% to 4% BHP better power reduction than a butterfly valve, but only at maximum"safe" turndown (throttle). Lower temperatures offer better, improved savings.

Payback:We found the current payback period for one IGV to be close to eleven years. In some situations, where several IGV are purchased and installed, the payback period was calculated to be as much as 43 years or more.

Conclusion:IGV is pressure loss deviceVariable speed is better than IGV

IGV()30


= =

=


?

A B C D

261.1KW 261.1KW 270KW 253KW

8 KG/CM2 8 KG/CM2 8 KG/CM2 8KG/CM2

(Package)

299.7KW,4P 1770RPM

261KW,2P3600RPM

270KW,2P3600RPM

253KW,2P3600RPM

(CFM)

1615 CFM20 C, 0%RH, atmospheric

pressure


pressure


pressure

1650 CFM30 C, 75%RH,

0.97 barinlet pressure

(KW/CFM) 0.1617 0.1697 0.1779 0.1534

?

2 3 4 1


SCFM (Standard Cubic Feet per Minute):14.7 psiA 60 0%RH

ICFM (Inlet Cubic Feet per Minute):

ACFM (Actual Cubic Feet per Minute):

OCFM (Operating Cubic Feet per Minute):

NM3/Min (Normal cubic Meters per Minute):1 atm 0 0%RH

FAD (Free Air volume Delivered):

Lb/Min (Pounds per minute):(0%RH)

Kg/Min (Kilograms per minute):(0%RH)

Mole/Min (Moles per minute):(0%RH)


ASME

ICFM

ACFM

0,97 bar

1,00 bar

ASMEPTC 10

ASMEPTC 9


Nm3/KW


(ICFMACFMFADSCFM)

1.01325

Psite (RH%/100 Ps)FAD (m3/min) = Nm3/min

Tsite

273

1.01325

Psite (RH%/100 Ps)FAD (CFM) = SCFM

Tsite

288.6

ICFM - Leakage losses (7.48% for ) = ACFMACFM - Intake losses(3% for 1 bar reference intake vs 0.97 bar) = FADFAD = ICFM x (100% - 10.48 %)


ICFM35250.975bar(a)

3525ICFM

15%


1bar3590%100m/minNormal

PI - ( RHI PVI ) TNNm3/min = Im3/min --------------------------------- --------

PN - ( RHN PVN) TI

0.1013 - (0.9 0.00562 ) (273+0)= 100 ---------------------------------------- ---------------

0.1013 - (0 0.00051 ) (273+35)

= 84 Nm3/min 1.013bar00%


1bar3590%100m/minStandard

PI - ( RHI PVI ) TNNm3/min = Im3/min ---------------------------------- -------

PN - ( RHN PVN) TI

0.1013 - (0.9 0.00562 ) (273+20)= 100 ---------------------------------------- ---------------

0.1013 - (0 0.00051 ) (273+35)

= 90.5 Nm3/min 1.013bar200%


ICFM(3518) SCFM(3051) 15.3%(291983%)BHP 605kw(Full Load 87.2%)


0.972Bar 35 60%RH TCWI 26.7ICFM (ASME-PTC10)


FAD20201bar(a)


1.0Bar 20 0%RH TCWI 20FAD (ISO1217)


200kw214kwPackage Input Power232.07kw+16%


=

Power Consumption

Free Air Delivery

1(KWH/NM3)=(NTD/NM3)


1

60-120m/s10,000rpm

400m/s40,000rpm

2-800m3/min(400m3/min)

100m3/min

(10)

(15)

8.6bar()

()

()


2

()

/

0-100%75-100%

75%

(

)

FAD

Im3/min()FAD/1.04

*


High Turbo Turbo type is goodEfficiency in a large capacity.

Low Screw(Oil free)

Expensive Any capacity is advantageousMaintenance in the maintenance cost

Cheap the turbo type.

Expensive The Screw becomes cheapPrice when becoming small.

Cheap

270kW In an comprehensive evaluation,Good the screw type of the small size

is good and the turbo typeBad of large size is good.

This figure is an image chart. 0 300 600kW

Rated power

Evaluation


VSD-TURBOIGV


1

2

Motor

3

1

Motor

2

< >

Air Air

< >


1

(300HP) (50kg / cm2)

100


2

Surge

380~460600HP


5.

3.

2.

4.

1.


CDA


CDA /


55L55L

.


CDA

CDA


CDA


PLC0.10.20.40.6MPa

(14)


V.S.


-1


-2


-3


-4


-5


1


2


3


ROI


NO.1 NO.2 NO.3 NO.4

3,380 m3/h 6,780 m3/h 5,100 m3/h 6,000 m3/h

40 40 40 75~105

- 10 - 10 ~ -50 - 40 ~ -65 - 40 ~ -75

3,278 m3/h 5,763 m3/h 4,900 m3/h 6,000 m3/h

Purge air 102 CMH 1012 CMH 200CMH 0

130 kw/hr. 27 kw/hr. 65 Kw/hr. 31 Kw

0.04142 Kw/M3 0.01895 Kw/M3 0.01735 Kw/M3 0.00517 Kw/M3

kw/m37.84 3.38 2.97 1.00


vs


Example:

V0 : 1.000 m/h (20C; 1,0 bar) pB : 8 bar abs. TB : 35 C : 13.5 % (Alumina) : 39,52 g/m (35 C )

V0 * TB * p0 1.000 * 308,15 * 1,0pB * T0 8,0 * 293,15

VB = = = 132.7 m/h

Water load: 132.7 m/h * 39.52 g/m = 4.7 kg/h

Required desiccant amount: 35 kgRequired desiccant amount: 35 kg

1 barg, 5C

Little Changes Heavy Impact


1. 7 bar a


2. 35C to 40C


BUTBUT

=== > Overload Ratio: 10 %

23 %=== > Overload Ratio :

Required desiccant amount: 39 kgRequired desiccant amount: 39 kg

V0 * TB * p0 1.000 * 308.15 * 1.0pB * T0 7.0 * 293.15

VB = = = 151.7 m/h

V0 * TB * p0 1,000 * 313.15 * 1.0pB * T0 8.0 * 293.15

VB = = = 119.9 m/h



3. 7 bar abs 40C:

Water load: 152,6 m/h * 51,03 g/m = 6.9 kg/h Adsorption capacity at 7 bar abs. and 40C: 10%

35 C 13.5 %, 40 C , 10 %

== > Overload Ratio: 43 %

== > Required desiccant amount at 7 bar a and 40C: 69 kg

== > Required desiccant amount at 35C : 45 kg== > Required desiccant amount at 40C : 61 kg

== > Overload Ratio: 49 %

V0 * TB * p0 1,000 * 313.15 * 1.0pB * T0 7.0 * 293.15

VB = = = 134.9 m/h



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7.


CAS Air Loss Map


CAS

26.3% 59.3% 0.9

2.0% 10.6% 1.3

/

10.5% 33.5% 0.8

7.6% 33.6% 2.7

2.6% 15.8% < 0.1

(per plant)

43.7% 65.0% 0.8


(Supply Side)1.

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3. 4.

5.

6. 7. 8. 9. 10.

Documents

壓縮空氣系統 節能管理技術 - asip.org.t · 節能不漏氣省電不客氣 威鐘黃茂興 © Weibell Copy Right 壓縮空氣系統 節能管理技術 主講人 威鐘企業黃茂興

壓縮空氣系統節能管理技術 - asip.org.t · 節能不漏氣省電不客氣威鐘黃茂興 © Weibell Copy Right 壓縮空氣系統節能管理技術主講人威鐘企業黃茂興