Gary,
The Arduino can be programmed to perform numerous tasks, many of which you have listed above. Other tasks to consider automating:
Fuel addition triggered by elevated hopper temperatures
Generator power monitoring
Grid tie controls
Dino fuel pump control for hybrid running or automated transition to woodgas
Automated Ignition advance
Buzzer or alarm light triggered by abnormal operating conditions that cannot be self corrected
I encourage you to read up on the Gasifier Control Unit (GCU) from All Power Labs, which is also Arduino based. Iām sure this will spark many more ideas.
I have seen the APL control unit but was put off by the price, I will go back and look at it further. If nothing else the code from thereās may be useful.
The dino fuel idea could also operate a butterfly valve between wood gas and dino carburettors.
I am excited by this Arduino, so many things that can be done by it. I have ordered a kit already on Ebay.
I had placed an order for a couple TC4 thermocouple shields used in the link you posted above, but the guy making them has ceased production. Iām hoping he will resume production if thereās enough interest.
EDIT: just went to try and order again, hereās his latest update:
Update 5-July-2013: It has become impossible for me to keep up with orders for these circuit boards. To date, each and every one has been built by hand in my small shop, but demands on my time are simply too great to continue āas-is.ā I am exploring other ways to get the soldering done while trying to keep the prices in line with where they are currently. I apologize to all who have placed orders and subsequently received a refund without explanation. I hope to have this situation resolved later this summer, but for now I cannot accept new orders.
For you guys who are interested in the Arduino approach, I have built a datalogger based on the allpowerlabs device, too. You can see its latest incarnation at: http://www.youtube.com/watch?v=RwoIPodGIQI(Sorry if some of you have seen this before).
But so far I am not taking advantage of the ability to actually CONTROL the system. Thatās because I am still learning WHAT to control, and exactly WHEN to control it.
On the subject of thermocouples:
If you are a cheapskate like me or canāt afford the more expensive approach, hereās a thought:
Buy these two items:
A digital meter----
K-Type Digital Thermometer/thermodetector 1300Ā°C TM-902C & Thermocouple Probe
$7.99 with free shipping from China
Ebay item number: 170968632720
The probe that comes with this setup isnāt shielded and its insulation isnāt good enough for our use.
So you can buy this sheathed thermocouple:
6 inch Long Steel Thermocouple Sensor K Type 3 Meter
$16.99 plus $5.99 shipping from Hong Kong
Ebay item number: 150624152323
Remove the connector from the probe that comes with the meter and connect it to this sheathed T/C, and there you go.
You can also find a lot of Type K thermocouples on Ebay and Amazon that have only 4" long probes, but I have found that I really NEED the 6" length to get to the center of my reactor (Chinese JXQ-10).
Note that the āthermometerā above reads in degrees Celsius.
Billy I found another solution for the connecting the K type thermo couples here http://oceancontrols.com.au/KTA-259.html Up to 8 of them and temperatures up to 1024 . Or another on Ebay 121138881917 single module which can read up to 1350 Ā°C.
Pete nice work there, can you tell us more about how you made the vacuum sensor and thermo couple shield? I have some of those cheap thermo couples but have had 1 fail already, I bought them with the meter that reads in Celsius which I consider a big plus.
My first priority is to get the air fuel mixture part working, then next is speed control as my belt drive governor is driving me round the bend.
The more I study the oceancontrols unit, the more I like it. Except for the price, that is! $72.31 for one shipped to the US. There is a 10% price break for 5 or more units, and shipping doesnāt go up until you put 7 units in your basket. So to make a long story short, I have 6 of the KTA-259K boards headed this way for $42.23 each shipped. If anyone wants one of these, itās yours for what I paid plus shipping to your door.
The few micro gasifiers I built are (were) not sensitive to mixture control. Once manually set, the engine gets a good mixture from high speed idle to full power. Sure it might be a tad to lean or rich, but if the engine doesnāt care, neither do I. The suitable woodgas mixture range is quite wide and let fuel economy be an item to discuss by the dying fossil fueled society.
The only reason why the mixture can get out of balance is because of hearth plugging or the opposite: a (temporary) hollow burn. Especially the little gasifiers are very sensitive to hearth dimensions, grate design and most important: fuel quality in size and shape. An electronic controled mixer can and will not deal with these facts.
Dimension the little ones bigger than theoretically the right size. A larger hearth and fuel deals better with plugging or hanging. Keep hearth temps at sufficient level by well insulating it.
I am now starting this project as well. This will be just the first stage of this, with just setting up the O2 sensor and interface system. I have the Botch wide band sensor with the Innovate LC-1 interface system. So at this point this machine Im working on will just have this stock set up and Ill learn how it works.
Right now Im building the machine that will have this simpler system to just monitor fuel ratio. This machine is my 5 kW DC CHP system and is the first one. Ive spent the last few days getting my butt kicked building a custom header for the 31 HP Kohler Aegis motor. This machine is very tight and compact, I think later versions I will give my self a little more room.
But any ways those that know a little about the depth of the sensor for custom exhaust, Im wondering if I did this correctly. The Kohler has its own O2 sensor, this is a single wire sensor. See pics to see the depth.
On the other wide band I think this was a no brainer as it came with its own bushing, I just welded in. But just in case Im attaching pics of it too.
Im going to create a thread in the small engine users corner for this build. So Ill update that as this machine progressās.
Those that are looking for a simple air preheat system, the blue bottle is a heat exchanger. This is for wood boiler systems to tranfer heat for hot water. I contacted the manufacturer and they said running straight exhaust through them is ok. This one was about 180 bucks on ebay, although its expensive its practically a bolt on system. Your time building a preheat system is worth something and this may actually be the cheaper option.
I am planning on a new thread also for Arduino based gasifer control and monoriting once I have some details to put up. My first priority is a governor, the generator I am using has a belt driven governor that I just canāt get right. I will monitor the generator output frequency and use a stepper motor to operate the throttle. Then I will get onto O2 sensing and control, then temperatures will be next.
The Arduino is also good for data logging as Pete has been doing already, you can store the data on an SD card or network the Arduino.
Pete can you tell me where you got your pressure sensors.
While I was looking at thermocouples I found an Acdelco exhaust temp sensor used on the turbo diesels for around $30. Did a little digging and found some specs on them but Iām not that good with electronics. Would these be useful with an arduino? Could a display be made using these or are thermocouples a better choice?
Specs:
Cat prob: P/N 0630-229
2011 Chev Diesel prob: P/N 12636945 (replaced by 12643246)
From what I have found K type thermocouples seem to be the way to go. They are readily available and the hardware to interface them to the Arduino is available off the shelf.
See Billy Boes post in this thread he has some of the interface boards at good price. There is a large range of K type thermo couples on Ebay and from many other suppliers that operate up around 1250 Celsius which is ideal for gasifier temps.
Thermocouples produce a small voltage when heated, the sensors in your link could be thermistors which change resistance with temperature. They most likely would work with the appropriate hardware, however I just received one of the thermocouple boards from Billy yesterday and will be working with it. They are able to take 8 thermocouples, so I can use the Arduino to monitor gasifier temps as well engine temperatures.
I have been getting my Freescale pressure sensors from Mouser. moderndevice.com also has some Freescale models, too. I did buy a couple of breakout boards for my 7007ās, etcā¦
Good Morning Fellows
Iāve been reviewing pre-publication copies of Ben Petersons new books.
I wanted to point out his Arduino boarded mixer solution.
Looks like what he was putting under the hinged fuels drying bin āhoodā on his VictoryGrid production units.
So a bugs-out, evolved, matured solution. Production level proven - not hobbyist.
Good very detailed step by step pictured fabrication book on exactly how to do this.
Gives parts lists with āprovenā suppliers ordering information.
Gives code lines.
Ha! Ha! As Iāve said plainly above I am happy with my varying engine speeds, and powers, DC charging solutions.
So I am disqualifying myself as āDC charging prejudicedā to electronics āreviewā this particular book.
But fellows still wanting to synchronous package engine-genset AC generate will need this to effectively woodgas use. This would be usable to woodgas fuel enable the new whisper-quiet Inverter engine/generators.
And . . . anybody PV Solar specific will find that THEY DO need engine-generator supplementing for those no-sun times of the years. So woodgasing is how to finally control those last diesel and propane pocket draining habits.
Okay.
Seems my book is an early publishers proof copy. The links tracks gave above have not been set up yet as of this date. Official Release set for the 15th of Sept.
You can see parts of this mixer project in this new video starting at 3:00 minutes in and to the ending at 5:44
What is not detailed out in this video is the engine/gen-head combo loaded and being controlled at a verifiable 4308 AC generated watts, at 119.2 volts, at 1860 rpm. You can hear this though. Can watch the servo motor contolling the air in mix. Can watch the O2 meter read-out:
Just in case my link does not work (as IS usual) this is Number 4 of 7 in Ben Petersons brand new Gasification 201 video series.
Enjoy your electrons and video āhitsā
Steve Unruh
Hey BillyB - I type very slowly anymore - we overlapped! Yep. Yep. You gonna love the R. Buckminster Fuller quote that he put in front of the book version. In fact; more of the Ben I know come out in his book prints than in the videos. A very humble man. Who welds and thinks a lot. Reads a lot. Cares a lot. s.u.
Brick kilns run varying temps. around 1650 f, carburizing metals intreating processes run from 1650 to 1900 f they use type k thermocouples in stainless steel wells protruding into the heated zonesif this helps anyone. Thanks to all the back yard engineers I believe we can piggyback Waynes process and win together enjoy reading great work all u guys are doing great.
