[Weter]

That's a new-hire fireman. Inexperienced one :)
As someone've said here: only a bit more clever, than steam stocker.

[cjakeman]

steamer_ctn, on 18 April 2023 - 10:27 PM, said:

Hence as suggested the boiler energy (and steam pressure) will often exceed the safety valve threshold in the AI mode. When the safety valves go off they waste a lot of steam (pressure drops) and tender water will be used more quickly. Thus it is not desirable to have the safety valves going off on a regular basis as this is not realistic and would detract from driving the locomotive. However behind the scenes this needs to happen so that pressure can be maintained at the optimal level.

In the AI Override mode the user can signal the fireman to start them building up or banking down the fire depending upon the track and operational conditions ahead. The user has to determine when to start and stop the fireman. Hence like in the real world they need to learn the route and capabilities of the locomotive to determine the optimal firing conditions. In this mode the safety valves are activated as the user has elected to take over a level of control of the firing process and poor firing will result in excessive safety valve operation.

Using Peter's descriptiion, I have submitted a Pull Request which extends the description in the Manual to explain when and why the safety valves are suppressed.

[Weter]

Thanks for keeping on working, Chris (and Peter)

[pschlik]

darwins, on 17 April 2023 - 11:32 AM, said:

One way to enable safety valve function with AI firing is to do this:

1. Alt+H - to increase AI firing rate

then

2. Ctrl+Alt+H - to reset AI firing rate

After that, I believe, safety valves should operate with AI firing!

As as follow-up, I just tried this strategy and it did not work. Using the NYC Atlantic again, I immediately used Alt + H to get the fireman working, then ran the locomotive as hard as I could. The safety valve did pop, at which point I reset the fireman and waited for the pressure to restabilize. Then I killed the throttle and let the boiler pressure increase to the limit...and nothing happened. Hitting Alt + H again updated the pressure to show it was too high.

So that makes it seem that overpressure is only checked when an AI fireman override is active, and once tripped the safety valve will continue to operate until the pressure is back to normal (even if the AI fireman mode is reset before then). If overpressure happens again, but the fireman override isn't set, then the safety valve will not activate regardless of prior use of an override.

[darwins]

cjakeman, on 22 April 2023 - 01:46 AM, said:

Using Peter's descriptiion, I have submitted a Pull Request which extends the description in the Manual to explain when and why the safety valves are suppressed.

It just seems as though this defies the laws of physics. If the safety valves never lift then the stored energy in the boiler can go on increasing for ever and ever and the boiler will never explode. If it is decided that the safety valves should never operate in the mode, then at the very least could we cap the amount of stored energy in boilers so that it can never exceed maximum in that mode?

[steamer_ctn]

cjakeman said:

1682156776[/url]' post='296303']
Using Peter's descriptiion, I have submitted a Pull Request which extends the description in the Manual to explain when and why the safety valves are suppressed.

Thanks for that.

pschlik said:

1682191373[/url]' post='296333']
So that makes it seem that overpressure is only checked when an AI fireman override is active, and once tripped the safety valve will continue to operate until the pressure is back to normal (even if the AI fireman mode is reset before then). If overpressure happens again, but the fireman override isn't set, then the safety valve will not activate regardless of prior use of an override.

As you point out the AI override mode is reset when pressure returns to normal and if it is not operated again. If it was allowed to continue to operate without any user intervention then we end up with the same "unnecessary" operations of the safety valves.

darwins said:

1681986052[/url]' post='296222']
(We now have a working blower model.)

Some work was done on a blower for manual firing, but I can't recall whether it was added into the Unstable code.

darwins said:

1681986052[/url]' post='296222']
If Peter is willing to try coding this would others be willing to test it out and propose and adjustments or improvements that may be needed?

Given the purpose of the AI fireman is to provide sufficient steady steam for users who don't want to interact with him, I don't want to waste a lot of effort trying to get a 100% accurate representation.

The AI override and manual mode are more specifically meant to support a more accurate representation of the AI fireman.

The current code uses similar triggers to control steam pressure.

I am happy, as a low priority to investigate some minor changes to the AI fireman mode, within the context of my comments above.

To consider these changes I would need some information from technical articles. What reduction in air volume does the damper impose when it is fully closed? Is it completely air tight? Whet % of heat loss occurs with the % of air volume decrease? I would need the links to any references found.

darwins said:

1682227164[/url]' post='296342']
It just seems as though this defies the laws of physics. If the safety valves never lift then the stored energy in the boiler can go on increasing for ever and ever and the boiler will never explode. If it is decided that the safety valves should never operate in the mode, then at the very least could we cap the amount of stored energy in boilers so that it can never exceed maximum in that mode?

The AI fireman has artificial limits so that it's primary function is supported, such as restricting pressure to maximum, not using steam through safety valves, not allowing boiler to explode, etc.

Limiting the heat upper limit may impact the performance of the locomotive in AI mode, especially if it starts from a station at the bottom of a grade. This "excess" heat keeps the boiler pressure high so that the combustion rate can "catch up". So as an "invisible" value I am uncertain of the value of doing this.

[Laci1959]

Quote

Hence as suggested the boiler energy (and steam pressure) will often exceed the safety valve threshold in the AI mode.

Hello.

In reality, sooner or later this leads to softening of the boiler and boiler explosion.
If we want to follow reality so much, maybe we should rethink this. Especially since Peter asked about the airtightness.
Darwins sent me a nice picture of the formwork. I don't think it's worth dealing with air tightness. Random somewhere between 0-10 percent.

Sincerely, Laci 1959