7 replies to this topic

[vikber09]

Hi!

I have calculated the dew pint temeprature of water vapor in exhaust from a diesel engine using a simple combustion reaction. With ideal gas relation I have calcualted the partial pressure of the water vaporu int the exhaust and then used it in the following formula:

Ps=e^(12,03-4025/(Tdew+235))

and solved the Tdew temperature from that.

What I wonder is if the constants in this equation not are applicable for exhaust or only for humid air?
(I know there is a small change in molecular weight of exhaust and air)

[siretb]

I think that this relationship is not valid for diesel exhaust. You want the ACID dew point
The reason is that the fuel contains sulfur, and that what you need is an acid dew point.
Is is also possible, if the diesel uses heavy fuel oil, that you have Vanadium. vanadium would promote SO2 to SO3 conversion, much lowering the acid dew point.

You need
The water content and the SO3 concentration (and to a lesser extent SO2)

[ELEMAN]

vikber09:
take a look to this site http://" target="_blank">http://www.hrsgdesign0.htm → Process → Acid Dew Point of flue gas.

Good luck !

[JoeWong]

vikber09:
take a look to this site http://<a%20href=" target="_blank">http://www.hrsgdesign0.htm</a> → Process → Acid Dew Point of flue gas.

Good luck !

Link problem...


I guess ELEMAN has proposed Acid Dew Point Of Flue Gas.

JoeWong

[ELEMAN]

Hello everybody:

You are quite right JoeWong, thank you.

[engware]

Hi there:

Here is an MS Excel file that deals with ideal and complete combustion of coal and oil type fuel.

http://engware.i-den.../combustion.xls

For stoichiometry values => 1, it will provide one with the flame temperature and combustion products composition on weight and mole basis. By knowing the H2O volume fraction, one can find out its partial pressure and see what the dew temperature value could be.

I thought that this might be of some help when dealing with the subject matter.

Thanks,

Gordan

[ELEMAN]

Hello everybody:

engware: this workbook is valuable, thanks for share it with us in the Forum.

[engware]

ELEMAN:

I am glad to be of some help to you and others at Cheresources.com and be able to share some of my work with those interested.

Thanks,

Gordan