diesel flow sensor lt/min ratings for various HP engines

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vas

vas

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slightly odd question, but necessary for my next move and purchases.
Trying to setup a diesel flow meter as a cheap alternative to the v.expensive Floscan using arduino, CANBus and NMEA2000 output. Keep in mind that yes I don't want to spend thousands for flow meter, but similarly I wont die if the rate is .5l/h off, I can live with that if the cost of the system is 100-200euro...

My boat has 2 IVECO8061SRM33 330hp turbodiesel engines and my problem is that I don't have a clue what is the flow rate of my fuel pumps. I need to buy sensors that are suited to the particular ranges.
So main Q is there a rule of thumb or specs that I can use to do my calculations?
Would a say 40-160lt/h range be enough? (not that I have one in mind!)

Second Q is the damper seen on the Floscan a really necessary option or can I skip that with a possible small discrepancy in values recorded?

Latestarter, other diesel experts, open to suggestions.
Seems that there's a load of hall sensors suitable for diesel with varying ranges in usually lt/min.

cheers

V.
 
I'm not sure why you would measure flow rate from pumps. You must measure flow and return, then compute the difference. The return ratio varies quite widely: you might have 20x fuel drawn then 19x returned to tank, or you might have a ratio more like 10 or 5. If your engines burn say 100 litres/hour you might want sensors that can measure 1000 litres/hour, or whatever.
 
Fortunately the range of sensors seems to be wide. Maretron offer:

24-500 lph, then
480 - 4200 lph

Click on "accesories" tab on this page: http://www.maretron.com/products/ffm100.php
I have 4 of the small maretron sensors to fit to my gensets to get fuel data on n2k, but haven't got round to the project yet. Will do one of these days, and report back
 
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jfm said:
I'm not sure why you would measure flow rate from pumps. You must measure flow and return, then compute the difference. The return ratio varies quite widely: you might have 20x fuel drawn then 19x returned to tank, or you might have a ratio more like 10 or 5. If your engines burn say 100 litres/hour you might want sensors that can measure 1000 litres/hour, or whatever.
Click to expand...

John, yes, I want to measure both on the in and the return pipes I just don't know what is the largest flow rate that the sensor must handle

cheers

V.
 
guys, I thought I made it clear but obviously didn't...

I WANT a 200euro solution per engine, not a 1400USD per engine.
Yes, I know maretron are there and they are among the best, it is simply that no matter what type of manmaths I employ I fail to get the ROI path :rolleyes:
I can have GPSMAP and GMI needles moving (possibly with slightly less accurate results) but for 1/10th of the cost and with a bit of effort on my behalf :p

Bearing in mind that over the last couple of months I've made impressive progress on arduino programming, sensor monitoring and NMEA2000 connectivity with all that working nicely on the Garmin GMI10s, I want to go the extra step for that manual diesel fuel consumption monitoring, that's all.

From some extra reading it has been suggested (on other similar output engines) up to absolute max 250LPH, which is in the 40LPM range. I can use that a basic rule of thumb if there are no other suggestions. I can knock off the system in an afternoon I recon and test it in my next outing at easter. I'd prefer a calibrated sensor but we'll see what I get.

cheers

V.
 
vas said:
guys, I thought I made it clear but obviously didn't...

I WANT a 200euro solution per engine, not a 1400USD per engine.
Yes, I know maretron are there and they are among the best, it is simply that no matter what type of manmaths I employ I fail to get the ROI path :rolleyes:
I can have GPSMAP and GMI needles moving (possibly with slightly less accurate results) but for 1/10th of the cost and with a bit of effort on my behalf :p

Bearing in mind that over the last couple of months I've made impressive progress on arduino programming, sensor monitoring and NMEA2000 connectivity with all that working nicely on the Garmin GMI10s, I want to go the extra step for that manual diesel fuel consumption monitoring, that's all.

From some extra reading it has been suggested (on other similar output engines) up to absolute max 250LPH, which is in the 40LPM range. I can use that a basic rule of thumb if there are no other suggestions. I can knock off the system in an afternoon I recon and test it in my next outing at easter. I'd prefer a calibrated sensor but we'll see what I get.

cheers

V.
Click to expand...

You will likely get more accurate results by working out a fuel consumption chart and then simply assuming the fuel consumption at any stated rpm. The reason why the units are expensive is because to get any useful accuracy at all you need very precise fuel flow meters on the inflow and return pipes and then do the maths. This leads to multiple errors being added up making a bigger error. The flow sensors need to be very accurate and with cheap ones the error is likely to be significant. Not bothering with real time measuring is simple and reasonably accurate. You could even add in adjustment factors for different conditions.
 
pmagowan said:
You will likely get more accurate results by working out a fuel consumption chart and then simply assuming the fuel consumption at any stated rpm. The reason why the units are expensive is because to get any useful accuracy at all you need very precise fuel flow meters on the inflow and return pipes and then do the maths. This leads to multiple errors being added up making a bigger error. The flow sensors need to be very accurate and with cheap ones the error is likely to be significant. Not bothering with real time measuring is simple and reasonably accurate. You could even add in adjustment factors for different conditions.
Click to expand...

with all respect, I disagree. I'm talking about a 100euro approx per sensor. I did buy some 2 or 4euro 1/2 inch sensors that are indeed crap and I don't even trust them to fit on the genny raw intake to report when blocked and avoid burning the small yanmar. For 100euro price you can get elliptical toothed sensors and some decent heavy duty devices used in the industry for measuring all sorts of liquids. They are not junk by any means.

Regarding the complex algorithms employed, sorry counting ticks, doing a multiplication and then a subtraction is something I can handle easily. I've already done it in implementing a windlass controller interfaced with NMEA0183 to a GMI10. I could even add a fuel volume compensation for the dTemp of the incoming and returning fuel fairly easily and accurately if it needs be. If the Maretrons are .1% accurate (not sure) a decent sensor can give similar values, but say .5% or 1% due to my rough programming, still more than acceptable and easy to do speed/trim regulations to reduce the reported value (even if this is a percent off real values, economy doesn't care, comparison is enough)

cheers

V.
 
vas said:
with all respect, I disagree. I'm talking about a 100euro approx per sensor. I did buy some 2 or 4euro 1/2 inch sensors that are indeed crap and I don't even trust them to fit on the genny raw intake to report when blocked and avoid burning the small yanmar. For 100euro price you can get elliptical toothed sensors and some decent heavy duty devices used in the industry for measuring all sorts of liquids. They are not junk by any means.

Regarding the complex algorithms employed, sorry counting ticks, doing a multiplication and then a subtraction is something I can handle easily. I've already done it in implementing a windlass controller interfaced with NMEA0183 to a GMI10. I could even add a fuel volume compensation for the dTemp of the incoming and returning fuel fairly easily and accurately if it needs be. If the Maretrons are .1% accurate (not sure) a decent sensor can give similar values, but say .5% or 1% due to my rough programming, still more than acceptable and easy to do speed/trim regulations to reduce the reported value (even if this is a percent off real values, economy doesn't care, comparison is enough)

cheers

V.
Click to expand...

You should be able to find the error rates for the various sensors. I was looking at this in the past, all-be-it for smaller engines, and the sensor accuracy at any reasonable price was simply not good enough. The compounded error after the maths has been done simply made it worthless for my project. However, the errors seem smaller as a %age with the larger flow rates so depending on your consumption maybe you will have better luck.
 
Spi D said:
Looks promissing. Could to with a twin engine display however. Fitting two of these phone-looking displays shouldn't be needed.
Click to expand...

Hardmy said:
I am afraid that you need one of those (ugly) displays per engine.
Click to expand...

hm, sensors look surprising similar to the ones here http://www.futurlec.com/Flow_Sensor.shtml (seventh down the page, yours for 13USD, but only good for 30lt/h I asked if they have something larger)

Sorry, I'm not making myself clear (yet again!) I don't want displays, I have two plotters and 4GMI10s to show the info via NMEA2000, it's v.easy to do, trust me!
I just want decent sensors, this system there is not what I want, I just need some 100-120euro a pop accurate sensors with digital output (all are!)

cheers

V.
 
pmagowan said:
You should be able to find the error rates for the various sensors. I was looking at this in the past, all-be-it for smaller engines, and the sensor accuracy at any reasonable price was simply not good enough. The compounded error after the maths has been done simply made it worthless for my project. However, the errors seem smaller as a %age with the larger flow rates so depending on your consumption maybe you will have better luck.
Click to expand...

true,

I'm coming back to this diesel measuring sensors every year or so, and it seems that there are more and better options every year. At 100-250LPH values per engine accuracy seems to be under 1% and repetitiveness of results under .1%

cheers

V.
 
Cant answer your questions directly but I do have Floscan on my boat and had a few problems with erratic readings which was traced to the dampers not working as they should. Easily fixed with advice from manufacturer but experience shows that the dampers are a necessary item. Remember that the computer is constantly measuring the difference between flow and return and if both fluctuate the real time readings will be erratic. Don't know how you are going to set up software to measure the difference but Floscan checks average flow rates over about 30 seconds to give a "current" reading and then of course computes total fuel used. If you know how to do the electricery to do this great but if you don't the flow rates alone wont really help. On mine with twin engines and computing fuel burn on either and both and then telling me fuel per N Mile by using GPS its even more complicated but perhaps you don't need all that especially with a single engine. Very good luck with your project. If you are near Portsmouth and need to see a Floscan give me a call.
 
boatmike said:
Cant answer your questions directly but I do have Floscan on my boat and had a few problems with erratic readings which was traced to the dampers not working as they should. Easily fixed with advice from manufacturer but experience shows that the dampers are a necessary item. Remember that the computer is constantly measuring the difference between flow and return and if both fluctuate the real time readings will be erratic. Don't know how you are going to set up software to measure the difference but Floscan checks average flow rates over about 30 seconds to give a "current" reading and then of course computes total fuel used. If you know how to do the electricery to do this great but if you don't the flow rates alone wont really help. On mine with twin engines and computing fuel burn on either and both and then telling me fuel per N Mile by using GPS its even more complicated but perhaps you don't need all that especially with a single engine. Very good luck with your project. If you are near Portsmouth and need to see a Floscan give me a call.
Click to expand...

thanks mike,

I can measure over a period of time (that's done in software so I can alter it as fit when testing) do the subtraction and the multiplication to get the value. Then the value is sent the NMEA2000 path to the Garmin plotter which based on the other info it gets from GPS f.e., can do automatically without me messing about the lt/nm and all other combinations of scary numbers. Increasing the period I measure in order to average values should alleviate problems with dumpering, at least I guess.
Mine is a twin engine installation so need 4 sensors and then two values to send to the NMEA2K bus, no big deal other than the cost of the sensors...
probably more than a couple of thousand of miles away, so wont take your kind offer! :)

cheers

V.
 
Whitelighter said:
Vas,

If you find a solution is like to try and copy for my boat.
If you want a contribution to development costs I'll chip in.

Jez
Click to expand...

Jez,

whatever I do will be available with instructions to whoever wants it. I'm confident of my arduino skills - development costs are a few espressos per feature :D Tonight's task fe is to get the pressure sensor for the diesel tank level measurement working and sending it's values properly to the N2K bus, couple of hours max.

V.
 
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