09-15-2010 06:41 AM
What should be the sizing of Inlet Louvers and Outlet louvers. I believe , Inlet should be 1.5 times then outlet louver.
The Diesel Genset is having a Radiator cooling system. I am facing a problem of overheating of the Engine at 90% Load ( 520 Kw ). I have checked the Air Flow for Inlet and Outlet of the Radiator. Here , Site condition is 42degC - 45degC Ambient.
09-15-2010 06:23 PM
Is this unit have a package radiator?
A general rule of thumb is for the radiator outlet duct to be 1.5 times the area of the radiator core, the inlet to be 2-3 times. These are open area, not total area, meaning if they have louvers, the opening needs to be bigger.
Do you have an Application and Installation Guide? The ventilation section has some very good information on ducting and sizing.
09-15-2010 08:04 PM
To start with the temperatures you have given are a bit on the high side for ambient air temperatures 42-45C (107-113F). Delta T from Ambient is 8.5-11C (15-20F) and Maximum engine room air temperature not to exceed 49C (120F) at the air cleaner (or derate accordingly). Rule of thumb, for every one (1) degree of intake air temperature rise there will be three (3) degrees of exhaust temperature rise. The exhaust ventilation air should be 110-120% of the incoming ventilation air and this will be combined combustion and ventilation air. To add more to the equation this will be multiplied by where the ventilation air enters and exits the room. This could be mutiplied by as much as 3.3 times the required ventilation air at full rated power depending on where the ventilation air enters and exits the room. Duct restriction can be measured fairly easily and should not exceed 2.46kPa (10in.) of water at full rated load. Sizing of combined combustion and ventilation air ducts the rule of thumb is, use 4-6sq cm per KW and 0.5-0.75 sq in. per H/P of duct cross sectional area.
I believe that taking measurements would better evaluate and help with a better correction for the problem and a better more dependable package.
I have argued this very topic many times with boat builders and a few container builder's. The times with the louver issues, the proof was easy, remove the louvers frame and all then retest. Most of my experience in this area is with marine applications I still use this as a basis for any application that I work with.
There is still more to this but I think the basic items are covered.
Hope this helps .
09-22-2010 12:33 PM
10-13-2010 08:54 AM
First Post. Thanks for the invite!
I would keep the simple things simple. Not knowing the direction of the fan, I would guess that it is a pusher. If it is a pusher, how much exhaust surface area is exposed? What is the ambient temp while the unit is running? Is the fan ratio correct ? Are the drive ratios for the fan correct ? Is the unit recycling the air from the radiator. ( updraft- forward draft, close buildings).
10-13-2010 01:14 PM
Thanks for reply.
Basically , Unit is running with ambient 40-42 deg C. There is many factors which affecting performance. I found , the outlet / discharge louver area is almost equal to the Radiator core area. Which may ristrict the ehaust / outlet Air flow ,
Planning to remove the louver and will have a load test run .
Radiator Fan is directly coupled with Engine shaft.