Modelling of Screw Compressor Capacity Control

8/3/2019 Modelling of Screw Compressor Capacity Control

http://slidepdf.com/reader/full/modelling-of-screw-compressor-capacity-control 1/7

Purdue University

Purdue e-Pubs

International Compressor EngineeringConference

School of Mechanical Engineering

1998

Modelling of Screw Compressor Capacity ControlN. StosicCity University

A. KovacevicCity University

I. K. SmithCity University

This document has been made available through Purdue e-Pubs, a service of the Purdue University Libraries. Please contact [email protected] for

additional information.

Complete proceedings may be acquired in print and on CD-ROM directly from the Ray W. Herrick Laboratories at https://engineering.purdue.edu/

Herrick/Events/orderlit.html

Stosic, N.; Kovacevic, A.; and Smith, I. K., "Modelling of Screw Compressor Capacity Control" (1998). International Compressor

Engineering Conference. Paper 1307.http://docs.lib.purdue.edu/icec/1307

http://docs.lib.purdue.edu/

http://docs.lib.purdue.edu/icec


http://docs.lib.purdue.edu/me

https://engineering.purdue.edu/Herrick/Events/orderlit.html




http://docs.lib.purdue.edu/me



http://docs.lib.purdue.edu/







CuN •• on. tl<le rock

-v oo k

E-F" L.ine F-G Circle G-H LnH- J Troc:hoicl J- t< Tn:u:lloidK-A Cir-cle A-1!11 ?grcboiiCIB-C Un•

c-o crrcl•

Rol.o.rs

Fig . 1: 5/6 and 6/7-127.5 mm Ra ck

G eneate d 'N' Screw Com pre sso r Ro tors

7

c:

·g 6

;:;-.._§_ 5

4 0

;;:: 3

2

60

i "5o

c.. 40

0

0.. 30

c:

20 1

!OJ

"5

~ 7 . 5 i 6.5

!t

__ 5 ba r

__ 7 bo r___ 10 bo r

13 bar

· • • M e a s m e n l 7 ba r

A ir Inlet I ba rAir Outlet 5-1 3 bar

' '~ I ; .... ,

~ ~ ; .

' '; I

' '' '

/ ' . '

I ci: 6.0

'' j ...

... ..0 1000 2000 30 00 4 000 5000 6 000 7 0 0 0

Shall Speod (r pm )

Fig. 2: Air Com pre sso r Perform an ces

?

"5 6

" 5 !t 4

.2 :3

3i

i .(0

!t0

c.. JO -A

12o.j

i

::: l-

{::6.5

!t

:6.0;::: 5.5o;

5 . 0 Il l

__ 5 ba r__ 7 bar

___ 10 ba r____ 13 bllr

• • • Measurements 7 bar

Shafl Spe ed 400 0 rp mAir O u l le l 5-13 ba r

\

\

4.5l4.0 . '

0.0 0.1 0.2 0.3 0.4 0.5 0.8 0.7 0.6 0.9 1.0Re altive lnle Pressu re

as a Functi on of Shaft Rotational Speed

Fig . 3: Air Com pre ss or P erform ances

as a Funct io n of Sucti on Throttling

c:

"5

" 5!t0

;;::

J::12

1?"5 6.0

" ?. 5

":;: ?.0

t 6.5! t0

6.0<.:: 5.5

4 .5

4.0

0

Fi

as





g .0 3 t,,.=+35 'c 4.o 4. 0 1"' J t , . .=-5 'C, t""=+35 'C l

4

E a3.ot E 3 . o ~ f" -----------------L L, j

- - - - - - -...

E0,"" lup=-5

9C1 lcon=+35 .o-C 0... 2

'o 2. 0 / • • • - - - - ----.-- - - - - - - - ----- 'o j 'o

•• •••·•· ............................................ 1.0 1 0 l0

1::::8 .• •· 0 · 0 l

U 0 0 i " I " • " ' < < < I U U 0 0 . : j . , . , ~ ~ , . . . , - ~ ~ r < T ' ~ ~ = = ~ n : : " ~ ~ T r T l . o' ' ' 2000 4000 6000 BOOO 0.0 o.'o 0

.2 0.4 o.'B oB l.O ' O.O 0. 2 0.4 0. 6 O.B 1.0

~ 4 0 0 ii=,.,.

....u"'~ 2 0 0 "'

~ 3 0 0 1 ... .,

] 2 0 0 ~ J

- - - - t.,,=+5 'c-5

-20-35

"' '1__ • • - 1 0 0 ~

blJ·;:...,.. - ... -=n -l

0 i > - ( . : ~ - ~ . : . : . : . : . : : . ...... - ~ - ~ - ~ - ~ . . . . . . . . . . . . . . . . . . .0 2000 4000 6000 BOOO

Shafl Speed {rpm)

Speed 6000 rp m45003000

___________... - --·

---- Speed 6000 rp m~ 3 0 0 " ] --- 4500 ~ 4 0ii= j ---- 3000 ii=

::.» »3

.. 2001 :::, Q

,./ ~ 2ns "'., [0

u 10 0 ... ... ... .--·. u, .............. "" . ~ 1

'- ........ .....<1

0.0 0.2 0.4 0.6 0.6 I. 0Relative Inlel Volume

Fig. 5: Refrigeration Capacity and COP

as a Function of Shaft Rotational SpeedFig. 6: Refrigeration Capacity and COP Fig. 7: Refrigeration Capacity and COP

as a Function of Inlet Volumeas a Function of Suction Throttling



Modelling of Screw Compressor Capacity Control

Documents