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Author Topic: Flash steam plant control.  (Read 89038 times)

flashtwo

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Re: Flash steam plant control.
« Reply #25 on: March 17, 2009, 03:06:46 PM »

Hi Nick,

That's quite correct!

Ian
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flashtwo

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Re: Flash steam plant control.
« Reply #26 on: May 21, 2009, 10:09:08 PM »

Hi,

Just a quick message to say the test vessel, with its flash steam plant and computer controls, is due for its maiden voyage at the Modelboat Mayhem meeting this weekend.

Over the last few weeks I've been tuning the control system for the best and most stable response, and the flexibility of the control method has enabled a few carefully crafted software mods to be implemented.

So, with sturdy software manual close at hand, the day of judement has arrived (gulp!).

I hope to be there early Saturday morning, so be prepared for something totally different!

A big thankyou,  once again, to SteamboatPhil  for his encouragement at the 2006 Warwick Model Boat Exhibition, its only taken 2 and 1/2 years but its been worth it.

Next project? I think I saw a suggestion somewhere on this forum for a steam powered Bluebird K7 - hmmmm........

Ian G.
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SteamboatPhil

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Re: Flash steam plant control.
« Reply #27 on: May 21, 2009, 11:04:14 PM »

I look forward to seeing it this weekend Ian
Phil
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kiwimodeller

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Re: Flash steam plant control.
« Reply #28 on: May 22, 2009, 12:28:35 PM »

And dont forget you have to post the results no matter what the outcome! Even experiments that do not go quite as planned are still a good learning.
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flashtwo

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Re: Flash steam plant control.
« Reply #29 on: May 22, 2009, 02:35:40 PM »

Hi Ian

I suspect I might learn a lot tomorrow - its fun and I musn't take it too seriously (despite the all the hard graff!) and I hope it raises a few chuckles and laughs.

As regards posting the results, it might make such a large impact (about crater size!) the other (surviving) Mayhemers may report back anyway.

It has been suggested that I name the boat "Flash-Bang-Wallop"; it has been named, but not that!

Well, I'm  off to load the car now - I hope I don't forget anything vital!

Ian G.
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flashtwo

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Re: Flash steam plant control.
« Reply #30 on: May 25, 2009, 08:12:43 PM »

Hi,

Well the maiden voyage of the computer controlled test vessel (now named the "VITAL BYTE" not "Flash, Bang, Wallop" - Phil) was a great success.

With engine oiled and the lead ballast loaded, the boat was lowered into the Wicksteed pond and the boat prepared for steaming up. The pumps were primed, steam system filled right through to the engine exhaust (its a flash system remember) and the raise steam sequence initialised on the computer system.

By this time a small crowd had developed and it was bit of a task answering all the questions as well  as remembering how to start the sytem.

The steam started to issue from the exhausts, I closed the drain valves, set the steaming rate  (both via the radio), and watched the pressure rise on the servo driven indicator. On going above 50kPa (sorry 7psi), I set the valve gear to forward and the prop started churning the water. Having ensured that the revs were stable, I gave the Vital Byte a push and off she went just like a kid on its first day at school (you're on your own now!).

I had planned for every version of failure, but not success - the craft just chugged off around the lake under complete control (the first, to my knowledge, of a remotely controlled flash steam model in the world , although corrections will be welcome!). I gradually increased the engine revs setting on the transmitter and the Vital Byte responded quiet well considering its displacement of 32kg (5 stone, 70lbs) and very primitive hull shape.

I'm afraid the sedate (compared with the high speed models) did not attract much attention and lacked totally the theatre and action of SteamBoatPhil's flash steam boats (including the  foot high flames!).

The only problem I had was that, on ocassions, the engine didn't go into reverse on the first call and it took sometimes a couple of thows of the valve gear to achieve reverse - going forward was successful every time (obviously the mechanical engineer's problem and not the software guy's!).

Vital Byte chugged around for ages, only coming back to shore to have the oil separator emptied and off around the pond again. At no time did the boat stop because of high temperatures. etc. It maintained a steady speed and wasn't affected by any gas cylinder cooling. I noticed from the gas cylinder pressure display, that, although the pressure dropped under hard running, the pressure soon recovered when taken back to a slower speed.

I measured the gas consumption for the day by weighing the cylinder before and after - it was 333grams, which was 72% of the original 460 grams in the cylinder.

A lot more interrest was shown when the boat was ashore when fellow Mayhemers could see the computer controls (the full spectrum of remarks were made!) - Dave from Action Electronics initially described me as a Geek on first seeing the control system, but then, kindly, after I had described the system, changed this to SuperGeek!

With confidence (and because the car was already loaded up), I took the Vital Byte to my more local lake (30ft deep) the next day. I had trouble starting since the new gas cylinder pressure was 3.4bar (the cylinder had been in the car under the hot sun) , which was far higher than the control system had to adjust for in tests. The gas valve sensitivity is automatically changed by the software with respect to the gas supply pressure and had effectively shut itself down due to the high pressure (a software mod coming up I see). To get around the problem I manually (via the computer) opened the gas valve for a brief period and the gas pressure dropped enough for the auto system to take charge and steam was raised as normal.

Again off went Vital Byte around the lake (giving way to sail where necessary) and a good mornings steaming was achieved using 228 grams of gas (50%).

Well, I shall now start adjusting the controls to enhance the performance and subsequently make a new computer (1/4 of the orignal size) now I know what is required for COMPUTER CONTROLLED FLASH STEAM BOILERS!

Ian.
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kiwimodeller

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Re: Flash steam plant control.
« Reply #31 on: May 26, 2009, 11:40:26 AM »

CONGRATULATIONS! Extremely well done but unfortunately not the first. There was an article in Model Boats, August 2005 by George Thomson about his r/c boat called OOYAH (the noise you make when you forget how hot some of the bits get!) which he eventually developed to do about 30mph under control although not computer controlled. This is the article that first got me keen to do something one day. Now will you please :-
A) write a book or at least a magazine article so we dummies can read it all through several times slowly
B) Package up and market the neccessary "plug and play" computerised control box with instructions on how to do it all.
I for one know my limitations and reading instructions and following them is something I can do!
Keep up the good work, I am sure the flawless performance was its own reward. Cheers, Ian.
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flashtwo

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Re: Flash steam plant control.
« Reply #32 on: May 26, 2009, 07:03:51 PM »

Hi Ian V,

Alright, alright  - the first radio and computer controlled flash steam model boat in the world (hows that); a bit like defining the first passenger train in the world.

Thats sounds interesting about George Thomson's boat OOYAH, I must track down a copy of the article.

Could you describe his method - it would very interesting to compare the two methods and we might come up with something even better (and simpler!).

I have been asked to write an article for "Engineering in Miniature" magazine, but wonder if it would address the right audience, plus the long delay between submission and publication by which time the Mark XII version would have been developed!. Perhaps the "Model Boats" magazine would be better since they have already published flash steam articles  - any ideas?

Regarding a "plug and play" version - well until the maiden voyage, I thought it was going to require a lot of skill in operating it, but not so, and also I can see some simplification is possible with the hardware by going for serial instead of parallel communication between the computer and the display unit (which is not needed on the boat anyway).

Did you see my posting regarding your pitch/throttle control problem?

All the best and thanks for your interest.

Ian G.


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SteamboatPhil

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Re: Flash steam plant control.
« Reply #33 on: May 26, 2009, 08:25:35 PM »

Hi Ian
Crongratulations once again, it was good to see it finaly go (and I missed taking a few pics, still this Sunday)
I would stick with the artical for EIM as a first hit and then maybe go onto MB. george's boat used a single cylinder uniflow exhust engine (much favoured by the the tethered hydro lot) with a flash steam coil and engine driven pumps (fuel and water) with vaporizing petrol blowlamps. 2 channel radio (steering and basic throttle)
However the first radio flash steam boat used the Alan Rayman designed high speed engine (the same as I have in Paprika which I was running at Wicksteed) which was about 10 years ago, however it only had steering.
So in a nut shell, yes you are the first to do a complete radio (and computer) controlled flash steam boat  :-))

Unless of course someone out there knows different  ;)
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Re: Flash steam plant control.
« Reply #34 on: May 27, 2009, 12:37:05 AM »

congratulations Ian.
wish i had been there,
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kiwimodeller

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Re: Flash steam plant control.
« Reply #35 on: May 27, 2009, 12:10:53 PM »

Ian, Yours may not be the first R/C Flash Steamer but it shore as heck is by far the most sophisticated and controllable. If you cannot find the article about Ooyah send me a P M with your address. I do not have the facility to scan and email it easily but would be happy to copy it and send it by snail mail. Cheers, Ian V.
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Martin [Admin]

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Re: Flash steam plant control.
« Reply #36 on: May 27, 2009, 06:33:49 PM »

Here she is seen at Wicksteed over the Mayhem weekend...
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flashtwo

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Re: Flash steam plant control.
« Reply #37 on: June 01, 2009, 02:22:04 PM »

Hi,

Thankyou Martin for posting the maiden voyage photos of the "Vital Byte", it is very much appreciated.

Yesterday "Vital Byte" made first steam on the Blackheath Pond, which, in flash steam circles, is a famous for it association with flash steam experimenting over several generations.

Having overcome the pond access problem of its inclined sides (SteamboatPhil gave me some welly - i.e. he lent me a spare pair), Vital Byte was steamed up (no problem this time with too high a gas cylinder pressure) and off it went around the pond.

I experimented with various superheat (software) settings and got up to a good speed. Again a lot of interest was shown at the pond side by Blackheath Club members and the public.

I had the honour of demonstrating the boat and its control system to Alan Rayman, the co-author of "Experimental Flash Steam". He said, considering the basic hull shape, that the performance was quite adequate for its displacement of 70lbs (32kg), I think the consensus was that I should now build a proper hull to get an even better performance. Alan also suggested doubling the size of the displacement oil lubricator, considering the long runs that I was doing, or even fit a mechanical lubricator.

Total gas consumption this time, including start-up, was 111grams (I must start timing the runs). I'm getting two good days out with one 460gram cylinder and that works out to about 2-60 per day for the gas.

One software change I'm going to make is to give the servo driven indicator on the "bridge" the ability to display boiler pressure or gas cylinder pressure. I can then use it as a fuel gauge to get the most out of each cylinder without ending up with lots of partially emptied ones, i.e. if i see the gas pressure dropping well below 100kPa (14psi) I will then think about bringing the boat back to shore.

Ian.
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gondolier88

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Re: Flash steam plant control.
« Reply #38 on: June 01, 2009, 05:44:38 PM »

Hi Ian,

Whats stopping this tech' being applied to full size flash steam plants- the auto software I mean- not so much the RC  :-))

Greg
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flashtwo

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Re: Flash steam plant control.
« Reply #39 on: June 01, 2009, 11:30:03 PM »

Hi Greg,

That's food for thought.

If the full size boat was gas fired and had an electric feed pump, then perhaps a higher torque gas servo and a higher rated ESC for the pump motor would be the main changes. A thermocouple would have to be installed to measure the steam temperature and a pressure transmitter for the boiler pressure. There would be no real difference in price between a full size or model boat control system.

If there is only an engine driven mechanical pump, then some means would be required to measure and control the feed flow by leaking off excessive feed. If the firing is with solid fuel then electric fans / air dampers would have to be employed to control the heat input, though the control would be quite sluggish compared with gas/oil burners.

The control system is designed to be tuned for different rates of heating, i.e. larger burners and more boiler mass.

I'm afraid that most traditional mechanical control systems for flash boilers were at their limit - they could not be easily modified for the best performance nor tuned for the best response.

With the software based system, there are lots of "features" like over-firing protection on start-up, high temperature and high pressure shut down of the gas valve, acceleration modes and also the ability to see whats going on regarding pressures, temperatures, feed flow and engine speed to mention just a few.

I suppose it depends on the boat owner - does he/she want to experiment or stick with the traditional methods and will it make the running easier.

The model boat is perhaps a useful tool for developing a system for a full size boat - modelling in the true sense of the word.

I'd be interested in any further thoughts you may have.

All the best,

Ian.

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flashtwo

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Re: Flash steam plant control.
« Reply #40 on: June 03, 2009, 06:31:01 PM »

Greetings All.......

I've just installed the latest software so that the boat times itself and displays the run time in minutes (saves me remembering to start/stop timing).

The computer now also records and displays the following data:-

a) Maximum engine RPM attained.
b) Maximum feed flow.
c) Maximum boiler pressure
d) Maximum steam temperature.
e) Maximum economiser outlet temperature.
f)  Maximum gas cylinder pressure....
g) ...... and Minimum gas cylinder pressure.
h) Total and Run engine revolutions (not RPM).
i)  Total and Run pumping strokes.

The servo driven mechanical pointer can now be selected to display the boiler pressure for start-up conditions and then gas cylinder pressure for cruising, so acting as a fuel gauge.

Now I know why its called software - its so flexible!

Must get the Vital Byte back on the pond to see if the latast software works.

Ian.

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flashtwo

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Re: Flash steam plant control.
« Reply #41 on: June 08, 2009, 09:59:58 PM »

Hi,

Vital Byte's skipper screws it up!

Vital Byte's latest voyage was down at Dover at the weekend (not in the Channel but at Kearsney Abbey!). The Model Boat Association Dover had its annual open day on Sunday and the oportunity was taken to do some test runs and play around with the control settings.

Questions were naturally asked about boiler certificates etc., but it was soon understood that none were required for a flash boiler.

The first run was going fine for the first 15 minutes, until Richard from the Maidstone Cygnets MBC made the remark that the response was very impressive - that was the death knell!   Vital Byte was going at Warp Speed 9, when it became apparent that steering was not what it had once been - "She's not answering the helm Cap'n" cried out an imaginary Scotty from the engine room!

As we were literally heading to the rocks something had to be done fast - luckily the engine went into reverse, VB slowed down and Alan Poole, of the Dover MBA, quickly organised a rescue mission. With the use of other members boats, VB was nudged to the shore. Thanks all round.

A quick examination revealed that the servo to rudder adaptor had become loose ( all that showing off of the response!); with a quick application of the screw driver, VB was soon back out on the pond, but without the skipper throwing the rudder all over the place.

VB did two long runs - one of 31 another of 44 minutes, the timing being done by VB itself. The new software features worked (except for total revs for some reason) and maximum and minimun parameters were logged. Gas consumption was 4.0g/min for the first run and 4.5 for the second run.

I did alter the feed water controller for the second run a bit too much and VB stalled out in the middle of the pond and became stationary - another rescue mission was offered by club members, but this became a test of its automatic recovery mode of operation (the Mars Rovers have nothing on this babe!). After a few minutes a wisp of steam was seen to rise and slowly VB came back to life.

I managed to capture some valuble data and will also now incorporate an average RPM reading. The maximum RPM achieved was 570 although I'm aiming for 800 which is what I obtained from Malcolm Beak's equations.

At the moment I'm trying to understand where the limitations are - gas nozzle size? gas consumption? heating area? etc.

Thanks once more to Dover MBA for their help and interest.

Ian.

p.s. One secret development I've not mentioned is the Carbon Capture environmental feature of the boiler. This was secretly photographed by Alan Poole of Dover MBA and I have obtained an exclusive  copy for Mayhemers! The green carbon capture spheres (CCSs) are collected from the pond after the experimental runs! (see attached photograph).
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flashtwo

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Re: Flash steam plant control.
« Reply #42 on: July 05, 2009, 10:10:42 PM »

Hi Mayhemers,

Just an update on the latest voyages of the Vital Byte.

VB has had a few mechanical and software problems over the last two weekends on the Cygnets Model boat Club venue at Mote Park, Maidstone.

VB had a run of 18 minutes to use up gas in a partly used cylinder and achieved 588RPM max with a gas consumption of 4.3g/min and then, with a fresh cylinder, a 53 minute run at 593RPM max and 3.7g/min consumption. Unfortunately the "A" pump motor blew its fuse and I had to swop over to "B" pump between the two runs.

Inspecting the pump later, I found that the ram was tight because the pump body had become slightly misaligned. With the help of a piece of SteamboatPhil's kindly supplied shim, the body was realigned and was tested OK.

The software recording the engine revolutions (and average RPM) was not working and was found to be due to part of the calculation taking place during the speed probe pulse. The calculation was moved in the software to occur after the pulse and the data is now being recorded properly.

Previously, at Kearsney Abbey, I had been monitoring the ambient temperature of the bow compartment where the gas cylinder is located with a max/min thermometer. Well, as reported elsewhere on this forum, the thermometer melted and it contents disappeared! Therefore, I have made a ventilation hole and an aluminium shield directing the heat away from the cylinder area.

The ongoing problems of putting the engine into reverse were traced to the drive-end "B" cylinder valve timing and also the "A" piston bottoming out, causing stiffness at bottom dead centre.

Having sorted all of the above problems, VB had another outing to Mote Park last Sunday - and what a disaster it was!

I spent the best part of an hour chatting to people about the boat and its computer before I attempted to put her on the water. The pump jammed again and the computer overheated due to the sun shining through its clear plastic cover (it was acting like a greenhouse) whilst it was on the shore. No voyage on that outing.

This time it was found that the pump was fine but the commutator end of its electric motor had become loose and resulted in loss of output. The gas control chip had failed on the steam temperature input of all things. A new motor and gear box was fitted and tested and a new PIC chip fitted and downloaded with the control program.

A fan was fitted to the computer housing for use on very hot days (you can tell this developed in the winter!) and the pump control software was modified to automatically switch to the standby feed pump within 6 seconds of the main pump failing and also a gas valve shut instruction was added if both pumps failed.

Today VB managed a decent run at last. She moved effortlessly between forward and reverse, maximum bow compartment temp was 28degC instead of 50plus and the pumps worked ok. Max RPM was 580 and average was 334. The engine was ticking over at about 50kPa (8psi).

On the water at the same time was the Cygnets 50th anniversary build of HMS Kent, type 23 destroyer. She was having a shake-down cruise before her epic voyage between Tonbridge and Allington Locks, via Maidstone, on the River Medway next Saturday 11th July ( visit http://www.cygnetsmbc.com/ for details of the day). The 12 foot model just cut through the water like a knife through butter, a magnificent achievement.

Vital Byte will be exhibited at the Guildford Steam Rally on the 18th/19th July, I hope to see some Mayhemers there.

Ian.

Below - the latest VB photo.

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Re: Flash steam plant control.
« Reply #43 on: July 05, 2009, 10:36:20 PM »

Great stuff Ian, oh the joys of flash steam. I have just re-done the fuel pump on my flash steamer, plus a new flame tube (I'm using vapourising petrol not gas like Ian)
Got a few good runs in today (in fact I won the steering event), also picked up a lot of weed. Keep going Ian (then I can pinch your data)   :-)) :-))
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flashtwo

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Re: Flash steam plant control.
« Reply #44 on: July 23, 2009, 10:47:16 AM »

Hi,

VB made it to the Guildford Steam Rally in one piece and was set up outside the marquee (it allowed room for four other smaller boats to be inside!) on it very own display stand. This was a bonus since it reduced the amount of carrying to and from the demo pool, though not such when it rained!

The demo pool was just deep enough for display, though, and being only 20x20 feet square, it presented a fine opportunity for learning to manoeuvre in confined waters. Full use was made of the reversing gear, now that it is reliable. About six demo runs were made over the weekend.

Although the pool size prevented maximum performance, it did allow the visitors closer inspection of the engine and its control system display, whilst in operation and also the method of raising steam quickly with the flash boiler compared with the more conventional plant.

With VB on static display, the boiler heatshield and control compartment covers were removed to allow the flash coil and computer to be viewed. Again the visitor response was as varied as their own experience. Some appreciated the boiler simplicity and just walked away on seeing the computer,  whereas others were very knowledgable on control theory and others on the use of PIC controllers.

It was an excellent oportunity to compare the flash boiler technology and it computer controls with a conventional steam plant on display in the marquee. The plant was to power a 82lb displacement tug also using a Stuart  D10 and running with a 4.25 inch prop. This was very close to the VB arrangement although there was no comparison in the hull design!

Chris the owner, and Guildford Club member, kindly took me through his design and build documentation book that he had on display. It was a very profesional comprehensive engineering document with all the materials lists and stress calculations and every thing you would want to know on how to construct the conventional boiler.

Both of us had used Malcolm Beak's calculation method, but the only trouble was that Chris had used imperial and I metric units, so making comparisons difficult (a certain  American Mars probe comes to mind!).

Chris described his boiler construction method and the difficulties that he had overcome. I came to the conclusion that I had transferred the effort of making steam from a boiler making to a software exercise. The flash boiler coil only took a couple of hours to wind and had two silver soldered connections,  but the control system  took many, many hours of work -  the complete opposite of the conventional approach. Chris's tug and marine plant have been built to a very high standard and he hopes to demonstrate it at next years rally.

A few Mayhemers turned up. Logoman with Logowife and Logokids were there, plus a few that that had seen the plant at the Ally Pally in January before VB was built. Their interest was very much appreciated.

Many thanks to Bryan Finch of the Guildford Club, who organised the boating section and greatly assisted me in carrying the VB back and forth to the demo pool. He has encouraged me to build a lighter boat!

VB will be at the "Boats on the Mote" Cygnets Club open day at Mote Park, Maidstone this coming Sunday. I shall be carry out a few experiments with VB.

Ian.






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gondolier88

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Re: Flash steam plant control.
« Reply #45 on: July 23, 2009, 11:06:15 AM »

Hi flashtwo,

Good to hear the different responses of people to the controls- your a pioneer in the model boat world mate! :-)) 8)

Just need a hull to match your electrickery now....!!!!! O0

Greg
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Re: Flash steam plant control.
« Reply #46 on: July 26, 2009, 12:02:34 AM »

Ian

I have been watching your progress from my side of the pond. Very interesting. Would it be possable to fit one of your computers to a conventional water tube marine model boiler at 100 psi and about 400 SQ In heating surface. boiler will be running a long stroke engine on a model stern wheel tug. search Steam Tug Portland.

Dave
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Re: Flash steam plant control.
« Reply #47 on: July 26, 2009, 01:10:34 PM »

Hi Dave,

Good to have you here mate. What are you wanting to be controlled by the computer? Do you want a crewless engineroom or secondary emergency control?

Greg
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Re: Flash steam plant control.
« Reply #48 on: July 26, 2009, 05:24:17 PM »

Hi Dave,

Thank you very much for your interest.

The conventional boiler is best to suited to a method of water level control, which would use an electric pump to top up the boiler when necessary. The level can be detected in various ways - optical through the level sight glass or via a resistance / capacitance probe within the boiler shell.

The flash boiler requires a different system where the electric pumps maintain a desired flow independant of the boiler pressure.

Also, the conventional boiler needs to control its steam pressure at a constant value by adjusting the fuel supply e.g. via a servo controlled gas valve. Normally this is achieved in a model by measuring the steam temperature with a thermistor, since steam saturation temperature is directly related to pressure. The thermistor, being a resistance device, would then be part of a voltage bridge circuit which would ultimately control a relay that operates the electric pump.

The flash boiler doesn't bother to control pressure, just steam temperature - aha! I hear you say, isn't this the same as the conventional where the pressure is the same as the temperature - well, no - if the steam pipe was open ended, for example, the gas valve would open to maximum trying to raise pressure, but would just overheat the steam (perhaps to 400degC or more) and stress the engine and piston seals.

My computer could be reprogrammed to control a conventional boiler, but it would a bit of an overkill.

I hope this not teaching grandmother to suck eggs, but the flash control is totally different from conventional boiler controls.

Let me know if you require any additional info and I will try and comply.

Ian.

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Re: Flash steam plant control.
« Reply #49 on: July 31, 2009, 02:11:12 AM »

Greg

Sorry for delay. Changes at work will put me out of work 15 months earlier than planed. We are crunching numbers now and it looks like we can make it the 8 months till I'm 62.
The Stern Wheeler I am looking to model is the Steam Tug Portland. She was retired from active ship handleing duties in1981. She is still aflot and they steam her a couple of times a year. Last year going up the Columbia river for a race she lost steering and damaged her rudders and paddle wheel. I was able to get a lot of pics while she was in dry dock. She is 210' LOA and 42' wide. The model at 3/8"=1' will be close to 7 ' LOA and nearly 16" wide. Engine will be 3/4" bore and 3 3/8" stroke. Will be full RC control and have an 8' barge with extra fuel and water for her to push around. I have not been able to find qualified marine engineers in 1/32 scale that will work for free so I will have to put automated controls on the boiler so I do not run out of water or steam in the middle of the pond.

Ian

Thanks for the reply. I will be researching how to best control water level and pressure. I expect the boiler to be a fast steamer with the number of water tubes it will have compared to the water volume that it will have.
 
I will continue to keep an eye on your project and will probably ask more questions.


Dave
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