Mr Spaceman
Topic Author
Posts: 2723
Joined: Thu Mar 15, 2001 5:09 am

King Air 200's Heat Exchangers - Question.

Thu Jun 12, 2003 2:31 am

Hi guys.

Here's a little info about the Raytheon/Beechcraft King Air 200 turboprop that is related to my question.

It has a pressurized, climate-controlled cabin. The cabin is pressurized using engine bleed air and can maintain a maximum pressure differential of 6.1 PSI. It has Pratt & Whitney PT6A engines.

It's all-engine service ceiling is 35,000 feet, and it's single-engine service ceiling is 19,150 feet.

Armed with the knowledge I have (thanks to you guys  Big thumbs up ) about how engine bleed air has to be cooled before entering the cabin via AC heat exchangers, I feel it's safe to assume that the inlets located on the leading edge of the King Air's wings - between the engine & fuselage - are ram air intakes for cooling the aircraft's heat exchangers.

I'm used to knowing that AC pack heat exchangers are usually located in an airliner's fuselage near the main landing gear bays, and the wings are full of fuel.

So my question is ........ If these wing LE inlets are for heat exchangers, how big are the exchangers, and how are they mounted in the wings? Is it a simple matter of "small" heat exchangers that are located between the wing's fuel tanks?

Here's the inlets (between the engines & the de-icing boots.)


View Large View Medium
Click here for bigger photo!

Photo © TZ Aviation



In this belly shot you can see the air exaust vents on the underside of the wings directly aft of the intakes.

View Large View Medium
Click here for bigger photo!

Photo © Ivan Coninx



Chris  Smile
"Just a minute while I re-invent myself"
 
erj-145mech
Posts: 305
Joined: Tue Oct 02, 2001 4:21 am

RE: King Air 200's Heat Exchangers - Question.

Thu Jun 12, 2003 9:45 am

You are correct in your assumption that the heat exchangers are in the wing center sections. The majority of the King Airs fuel is housed in the engine nacelles and outer wing panels. There are aux tanks in the portion of the center section, between the two wing spars. Also, the main battery is located in the right wing center section.
 
Mr Spaceman
Topic Author
Posts: 2723
Joined: Thu Mar 15, 2001 5:09 am

RE: King Air 200's Heat Exchangers - Question.

Fri Jun 13, 2003 4:56 am

Hello Erj-145mech.

Thanks for your reply.

OK, so my assumption was correct. Those intakes are for heat exchangers (which must be very small.)

That's nice to know, because I'm way off the mark quite often. It's pretty funny when I post a question and throw in a wild guess as to what the answer might be ....... and I'm so wrong & clued out!  Laugh out loud

Here's were the aux tanks are filled.


View Large View Medium
Click here for bigger photo!

Photo © Patrick GABRIEL



Chris  Smile



"Just a minute while I re-invent myself"
 
aaron atp
Posts: 517
Joined: Sun Mar 19, 2000 1:17 pm

RE: King Air 200's Heat Exchangers - Question.

Fri Jun 13, 2003 10:07 am

as long as you don't start asking about air cycle machines, everyone will be ok...

aaron
 
Mr Spaceman
Topic Author
Posts: 2723
Joined: Thu Mar 15, 2001 5:09 am

RE: King Air 200's Heat Exchangers - Question.

Sat Jun 14, 2003 4:23 am

Hello Aaron atp.

Have no fear.

I wasn't going to ask if there was also air cycle machines, mix manifolds, Hepa filters, etc, located in the wings.

However, I'm am a bit curious about whether or not King Air 200's have Catalytic Converters (like airliners do), between the engines and cabin to eliminate the high levels of ozone in the bleed air while cruising along in the upper flight levels.

Do they?


Chris  Smile
"Just a minute while I re-invent myself"
 
LSTC
Posts: 277
Joined: Sun Jun 01, 2003 11:45 am

RE: King Air 200's Heat Exchangers - Question.

Sun Jun 15, 2003 12:13 am

Nope. Ozone elimination is not a FAR 23 requirement. By the way, the picture of the AUX tanks you provided is a bit ambiguous. The AUX tank filler cap is the red cap on the wing. The nacelle tanks are in the forward portion of the hump in the picture. The aft portion is empty.

You AUX fuel is unusable unless you have fuel in the mains, as a jet pump driven by main tank fuel flow is used to draw fuel from the AUX tank.

Another strange characteristic of the heating system, is that the bypass valves operate in "series". That is temperature control operates one valve until it reaches its extreme, then operates the other valve. And of course...there is no ACM. So you can't get cooling out of the bleed air, just heating.

The King Airs use vapour cycle air conditioning for cooling. You can see the vents for the evaporator in the nose.
 
aaron atp
Posts: 517
Joined: Sun Mar 19, 2000 1:17 pm

Ah...

Mon Jun 16, 2003 10:10 am

sweet nostalgia.

Lstc, just for your humour, the ACM comment was a reference to these threads (both are part of the same 250 post discussion)...

http://www.airliners.net/discussions/tech_ops/read.main/27236/

http://www.airliners.net/discussions/tech_ops/read.main/31097/

check it out when you have a week to spare.


aaron

(I may be crossing a fine line by posting a link to that debate)
 
JETPILOT
Posts: 3094
Joined: Tue May 18, 1999 6:40 am

RE: King Air 200's Heat Exchangers - Question.

Sat Jun 21, 2003 7:56 am

I havent flown the 1900 for some time, and I'm a little rusty on the systems, but I distinctly remeber that the King Air/1900 have both ACM, and VCM's.

The heat exchanger is not to cool the bleed air, it's to cool the air after the ACM compressor , and before it enters the expansion turbine.

I remember something about the VCM not operating after weight off wheels. Ours were always INOP anyway so I never got to use it.

JET



 
LSTC
Posts: 277
Joined: Sun Jun 01, 2003 11:45 am

RE: King Air 200's Heat Exchangers - Question.

Sat Jun 21, 2003 8:05 am

Jetpilot,

Yes. The 1900 does have ACMs. The 90s, 100s, 200s, and 300s do not. I don't think the 1900 is really considered a "King Air" is it? Although we do know the relationship, the type certificate calls it a model 1900 "airliner".

 
JETPILOT
Posts: 3094
Joined: Tue May 18, 1999 6:40 am

RE: King Air 200's Heat Exchangers - Question.

Sat Jun 21, 2003 12:34 pm

Thanks for the info...

I shouldn't make assumptions.

JET

Who is online

Users browsing this forum: Baidu [Spider] and 9 guests