high pressure air to air heat exchanger

[spiderman]

i'm designing an air system and need a high pressure air-to-air heat exchanger.
the maximum pressure of the air is around 3 bar, max temperature from about 60 and lowest is around -30 degrees Celsius. the air is 60 degC after compression and goes into a turbine.

the heat exchanger cools down the compressed air to -30degC.

i'm having difficulty finding out who could help me custom make this air-to-air heat exchanger.
the companies i tried contacting for this are usually using ambient pressure air and for heat recovery systems.

i think the best efficient type would probably be plate type heat exchanger for my application.
i've already tried searching through google, thomasnet.com and not getting much progress from there.
is there other directorys online which i can use to find out companies that design and manufacture custom air to air heat exchanger (pressure of air above ambient pressure)?
please enlighten me.

thank you for your time and help.

[Brian_UK]

Interesting application you have there Spiderman.

Just trying to get the scheme right in my head.....

Air at 3bar into compressor
Air now at +60°C
Air into turbine at +60°C
Air exits turbine at ? +60°C ?
Air into heat exchanger at +60°C
Air exits heat exchanger at -30°C

Why the need for the large temperature change and where is the air going when it is at -30°C?

[The MG Pony]

I think it goes:
3Bar Air > Compressor > 60+C Air > HX > -30C Air > Turbine > Off back from once it came?.

Reason for this would be the at its highest density for more turbine efficiency.

[Brian_UK]

That's what I would have thought too MG.

[spiderman]

temp of air out from compressor is 60degC.
air goes into the air/air HE then into turbine. temp of air is now @ -30degC.
this cold air goes back into the HE (warmed up by the hot compressed air 60degC) goes into first stage compressor.
essentially pressure drop is minimal for a good heat transfer.

the main problem is finding companies out in the market that would have the facilities or suitable to help me manufacture this.

[monkey spanners]

How do those air dryers work on compressed air systems for paint spraying etc. Is the dryer after the compressor, if so it would be rated for 10bar or so. Maybe the heatexchanger in one of those would be a starting point. Or an intercooler off of a turbocharged car. There are companies who will build these to your specifications.

Cheers Jon

[Brian_UK]

What is the airflow rate of the system?

[spiderman]

brian:
the airflow is around 3kg/s.
i was looking into car intercoolers as well.
but i want to see if there is a air/air heat exchanger that could be made for my application.
my application is a cooling system. ie. refrigeration using just air.

thanks for the replies

[US Iceman]

I THINK THIS IS WHAT YOU ARE LOOKING FOR:

http://www.chart-ind.com/litfiles/EC000003.pdf

[spiderman]

thanks ICEMAN but the pdf file did not mention it for an air/air application. its used for liquid/liquid, gas/liquid.

[US Iceman]

There are other heat exchangers like this for air-to-air purposes. I just couldn't find anything quickly.

Here is another firm that makes a similar type.
http://www.lytron.com/standard/he_plate-fin.htm

[Brian_UK]

Yes, Chart show their Astrocooler which is air/air taking 8sfcm from 300°F (150°C) to 2/3° above ambient.

[autt]

Hi Spiderman,

I just have some jobs with these turbine cooling systems by now and know several plate-fin HX producer, from Nanjing and Guiyang respectively in China.

But to custom the HX, you need to give more clear requirements, I usually give that:

Hot side:
Flow rate
Pressure
Inlet temperature
Cool side:
Flow rate
Pressure
Inlet temperature

And requirements(Include spare capacity)
Hot side:
Outlet temperature(Or efficiency)
Flow resistance
Cool side:
Flow resistance
Dimensions
Pressureproof value
Joint type

For your application, there need a dryer (A regenerative type for long time running) placed after compressor to remove water under dew point of -30 degC.

For the HX you need, I usually call it reheater, which has same flow rate at both sides. You have to give its outlet temperature to HX producer, they need it for design. To calculate the temperature, you need to know turbine efficiency and iterate the system.

If you speak chinese and your computer show simplified chinese properly, I will send their contact info to you by message, or I can ask them for you.