Steam consumption rate and efficiency of turbine 1

[MAEC]

Dear Members:

I am conducting an analysis of a cogen cycle and found something I'd like you to comment on.

The turbines I analyzed are single stage turbines. I contacted the companies that made them and they gave me their steam consumption rate as a tool to obtain the efficiency of the equipment. The value was given based on the plate's operational conditions. Now, I have better steam properties than those indicated in the equipment so the steam consumption I got theoretically is quite lower than the one they gave me.

I followed the procedure they told me to follow in order to obtain the efficiency but the value I think is not reasonable (quite high for a single stage turbine). The procedure they told me is the following:

I have to calculate the steam consumption with the plate's operational conditions considering a 100% efficiency and then obtain the steam consumption with the steam rate they gave me, then I have to divide the second value into the first. They say that should give me the efficiency.

Now, for the operational conditions I have, it gave me a lower consumption per kW. How can I relate this even lower value with those I obtained in order to get an efficiency value?? Getting it like that obviously throws an efficiency of more than 100% !! This guys really confused me here... anyone out there willing to give me some tips or a procedure to do this?

Best Regards

MAEC

Manuel

 

[katmar]

Manuel, there is a free steam turbine steam consumption calculator available on my web page. See my signature below. If you use the efficiency the manufacturer has given you, and then plug in your actual steam conditions, you should get close to the true answer. Obviously, the closer your actual steam conditions are to the conditions under which the efficiency was determined, the more accurate your results will be.

I am confused by what you mean by "plate". I think there is a mis-translation there. I assume you are referring to the original design conditions, which I would term the base conditions.

regards
Harvey

Katmar Software
Engineering & Risk Analysis Software

http://katmarsoftware.com