nicho
RIP
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You only need vent fans at inlet or outlet. Depends if you want to run the engine room at under pressure or over pressure. The engine will always take what it needs you can be sure of that!
All engines will be derated for ambient conditions based on a set of (usually) ISO standard conditions. I dont know what they are right now for the VP marine range or what their dreating factors are. Generally there is a derate for altitude (not a problem for marine engines of course!!) a derate for ambient temperature (in the engine room or more correctly combustion air inlet temperature) and intercooler water temperature. For shore based engines relative humidity is also considered as that will determone wet buld temperature if cooling tower cooling is used.
So depending what the starting point for derating is on VP marine engines the combustion air temperature could well be a factor as could sea water temperature for intercooloer efficiency. I noticed on one of the VP industrial diesels the derating on ambient was 2% for every 5 DegC above 40C but on a site for marine engines I also saw ISO conditions quoted as 25C, 100kPa and 30% RH so not sure what it is for your engines. If its 32C ambient you could easily have 40C in the engine room and if derating starts at 25C it could be a noticeable reduction in power!!
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Blimey David, you know yer stuff!
You only need vent fans at inlet or outlet. Depends if you want to run the engine room at under pressure or over pressure. The engine will always take what it needs you can be sure of that!
All engines will be derated for ambient conditions based on a set of (usually) ISO standard conditions. I dont know what they are right now for the VP marine range or what their dreating factors are. Generally there is a derate for altitude (not a problem for marine engines of course!!) a derate for ambient temperature (in the engine room or more correctly combustion air inlet temperature) and intercooler water temperature. For shore based engines relative humidity is also considered as that will determone wet buld temperature if cooling tower cooling is used.
So depending what the starting point for derating is on VP marine engines the combustion air temperature could well be a factor as could sea water temperature for intercooloer efficiency. I noticed on one of the VP industrial diesels the derating on ambient was 2% for every 5 DegC above 40C but on a site for marine engines I also saw ISO conditions quoted as 25C, 100kPa and 30% RH so not sure what it is for your engines. If its 32C ambient you could easily have 40C in the engine room and if derating starts at 25C it could be a noticeable reduction in power!!
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Blimey David, you know yer stuff!
