How to Specify Ambient Conditions For Power Plant.

I would think that in this sort of document prospective clients would be more concerned with extreme conditions, such as altitude, and/or temperature , perhaps even marine environment suitability etc....the exact swings of temperature and humidity don't seem necessary... but rather a general statement as to preparations made for anticipated location requirements....therefore I might list the design limits as presented with a disclaimer that special preparations may be needed for extreme environments that would exceed the present design specifications for optimal performance....

http://powerplants.man.eu/fuels/hfo

http://www.dieselserviceandsupply.com/Generator_Output_Rating.aspx

http://electrical-engineering-portal.com/site-conditions-impact-on-caterpillar-genset-ratings

The max 83.7 RH sounds odd; does it never rain there? Or is this a value that can be exceeded a small percentage of the time?

An altitude limit of 2.9 meters tells me this has nothing to do with reality. This power plant could only be installed on the beach near the ocean.

Anonymous posters should not be allowed to prepare technical specifications for a HFO fired engine to be included in a tender document.

You are not qualified.

If you were, you would not be asking an anonymous forum for technical advice.

Do your own homework.

Thanks for now identifying the previously unspecified acronym, HFO. Will the engine be a modified VW Rabbit diesel engine, fuel oil heated steam boiler driving a steam turbine, or some other engine that consumes this type of fuel to turn your mechanical load. Unless you've found a miraculous way to control the outside weather conditions you should refer to historical weather conditions for this mysterious location and allow for some very broad ambient conditions. If you intend to put this engine inside a building how do you intend to get the waste heat and exhaust out of the building? Surely this will have an effect on the ambient conditions in the building.

How much are you willing to pay others to do this job?

Don't bother being too specific with trying to specify your plant to actual ambient conditions, just use standard generic conditions the equipment is already specified to that common sense match the country (like the ambient condition specifications for the generators).

The more specific you are in the tender with ambient conditions the more problems you will have because others tendering won't be doing this and it will raise questions as to your plant suitability. As long as they can see the equipment will be suitable (for example if the installation is to be in a very cold or hot environment) that's all they are really looking for.

"The equipment is to be installed at XdegN/S, YdegE/W at an altitude of Z metres above/below mean sea level and is to be suitable for the prevailing and predictable weather conditions at that location until the year 20xx."?

Such a statement places the burden on weather and altitude compatibility upon the equipment supplier.

Tell the HFO engine OEM, that the temperature could be outside the minimum-maximum range for 10% of the time (just for covering bases)

Your humidity data is goofy - If humidity never gets over 84%, then you must be in the Atacama high desert. Maybe that was supposed to be 84% RH on average. That makes a lot more sense to the average engineer, not the maximum engineer.

If your elevation (altitude) is 2.9 meters, most engines will run better (including any gas turbines, or piston type engines) near sea level and 20 C than way above that in elevation, and way hotter. For example: if 40 C and 1000m, engine performance could drop off by at least 15%, more likely 20%, simply due to issues with compressing combustion air.

Humidity is not particularly helpful for hot air intake values, as this also lowers air mass flow (especially reduces oxygen flow to combustion zone).

Temperature data should be based on a 100 year history for the site. State the minimum and maximum, and subtract/add 5 degrees for each.

I don't know where you are getting your humidity, but most industrial equipment is required to withstand 0-95% condensing. Equipment required to be outdoors will be rated as such and need not be addressed.

Your elevation is negligible, therefore I would state it as "sea level".

Not knowing where your plant is located, there may be other specifications required such as snow load, wind load, seismic criteria, etc.