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Genma Saotome, on 16 July 2014 - 10:04 AM, said:
I understand that. What I am concerned about is the parameters for coal burning are, essentially, irrelevant to an oil burner. The oil is heated so it flows as readily as water and is sprayed into the firebox where the droplets burn in the air. No fire mass, no grate, no grate area. All of the steam locomotives used along the Pacific Coast of the US (in the 20th century) were oil burners so it is not an insignificant number of locomotives that fall into this situation.
I'm also a bit concerned about this boiler efficiency curve -- I understand the importance of boiler efficiency -- that makes perfect sense -- but I do not understand the notion of it having a curve. All of the steam locomotive data that I have seen that provides data on boiler efficiency do so with a single number, sometimes over 100% but usually in the 95-98% range. Perhaps they are all oil burning, I don't recall now, but even if not, the question remains: Why a curve?
I'm also a bit concerned about this boiler efficiency curve -- I understand the importance of boiler efficiency -- that makes perfect sense -- but I do not understand the notion of it having a curve. All of the steam locomotive data that I have seen that provides data on boiler efficiency do so with a single number, sometimes over 100% but usually in the 95-98% range. Perhaps they are all oil burning, I don't recall now, but even if not, the question remains: Why a curve?
First, boiler efficiency. The test data that I have used is taken from British Railways Rugby Test Plant report and clearly shows a downward curve as larger amounts of fuel are consumed, starting at about 95% with very low fuel figures running down to just over 60% at a firing rate of 5000lb/hr. Plugging this data into the eng file gives the same curve as expected, whereas the basic code gives a different result if no curve data is used. The firing rates on the Bigboy would produce even lower efficiency figures, but that is compensated by the vast size of the boiler.
Turning to oil burners, they are not yet fully modelled, and as they are not in MSTS either the code is so far MSTS compliant. There is a need for a dedicated oiler code segment and it will follow eventually.
