Fuel savings built into the software

Posted: April 16, 2013 | Author: | Filed under: Arduino | Tags: , , , , , , | Leave a comment

I added a function to check for the time of year and hour of day to shut the boiler down automatically, I mentioned this in the last post. But as the days get warmer I wanted to make additional changes. I probably ought to be calculating the HDD and comparing to the present outside temperature to calculate a dynamic time needed for adequate heat, however that seemed too complicated so I wrote a simple function to check for date and time. At this time of year it shuts the boiler off at midnight. In March it ran until 3 am.

void FuelSavingsDateCheck() {//start function
DateTime now = RTC.now();  //get the data from the RTC
Month =now.month(),DEC;    //get the month from the RTC
Day =now.day(),DEC;        //get the day from the RTC
hour = now.hour(),DEC;     //get the hour from the RTC
if (Month ==12 && Day <15)  //month of December before the 15th
{//start if section
if (hour >3 && hour <9)  //shut off time of 3 am
FuelTest =0;
else
FuelTest =1;
}// end if section
if (Month == 3 && Day >15)  //after March 15th
{//start if section
if (hour >3 && hour < 9)  //at 3am shutoff burner
FuelTest =0;
else
FuelTest=1;
}// end if section
if (Month == 4)              //month of April
{//start if section
if (hour ==0 && hour < 9)  //midnight shutoff
FuelTest =0;
else
FuelTest=1;
}// end if section
}//end function

Software cuts pellets by third, saving $112/month

Posted: January 28, 2012 | Author: | Filed under: Arduino, Homemade Boiler, Hopper and Feed, Testing | Tags: , , , , , , | Leave a comment

Minor changes in the software that force the boiler to maintain a tighter range from the set point has cut the fuel consumption from 3 (40 pound) bags of pellets to 2 daily.    These software improvements and a extension to the pellet hopper mean the boiler will now run 24 hours without needing  additional fuel.    The hopper extension adds at least another 40 lb bag of pellets capacity bringing the total capacity to approx. 2 1/2-3 bags.  I haven’t measured only estimated.

The boiler  set point is currently set at 135°F which seems to work just fine for the temperatures we have been having and the software is consistently running within4 degrees of set point.  This range may seem excessive but seems to run just fine.  The program is becoming more modular in that there is only one number to change,  the set point.  The set point currently  is a variable declared in the setup section of the program but eventually the set point will be self adjusted by the program based on the outside temperature.  Economy and efficiency by software optimization is the goal for this next week.

We have had a very mild winter in my opinion.  The Heating Degree Day total for the month of Dec 2011 was 1091 as measured by the local weather station.  The normal is 1209 HDD a difference of 118 HDD, not as much as I would have thought.  The total for the month of January 2012 so far is 1140 with four days to go, with a normal of 1419.  We’ll see how the month ends but if it continues as the average day it will be short approx the same number of HDD as  last month,December.   My interest in HDD is to see if there is a correlation to HDD and fuel consumption.  There should be and if there is than the fuel economy is starting to improve.  As I told a friend of mine, at this point the boiler is like a truck I used to own, 10 mpg  going uphill loaded, 10 mpg empty going downhill….so seeing fuel consumption changing to track the weather will be the first step to seeing some optimization.

Software work on fuel economy and the  extrapolation of costs for the upcoming remainder of the season is of great interest.    The next step in fuel economy may be better insulation  of the boiler and piping and will not be as simple as software improvements.  But if I can get a correlation between the outside temperature and fuel consumption that is measurable then the software will be nearly optimized and further improvements will have to come from physical changes.  This week sees a 40 pound bag and $4.00 improvement per day, $28/week, $112 per month.  Next week’s goal:  another $60/month.  I am hoping for a total seasonal heating cost of $500 or less using $200/ton pellets.  I will consider that a huge victory for heating a 2300 sq ft house with 3 garage doors.

More combustion air

Posted: January 5, 2012 | Author: | Filed under: Homemade Boiler, Testing | Tags: , , , , | Leave a comment

2nd Fan with slip joint connection

To increase the combustion efficiency a second fan was added.  The smoke coming from the boiler was very thick at times and really needed more oxygen.  So a second fan was added, to help add more air and help keep the chip feed area cool.  The parts slip together and allow a quick look down into the burner area.  This allows you to be able to visually check on the feeding, and the fire by simply lifting the fan.  So far I am happy with the change and the biggest difference is the ability to see the feed rate appropriateness.  Already I want to change the program to allow smaller bites less often because the fuel is backing up the feed pipe.  Because of computer issues, the laptop I was using wouldn’t  recognize the USB port the Arduino is plugged into more than one or two uploads, I am attempting to switch computers.  The 2nd computer at my disposal is running Windows 7.  Not nearly as easy to use as XP Pro that I am used to using in opinion.

So, I am having difficulty communicating with the Arduino.  I may have to go back to the first computer.  Ain’t computers grand?  I am a lot happier with a welder and plasma cutter.  My weight this morning was 193.8, down 1.9 lbs.  Probably water weight although I have stopped drinking beer for a little while.   Ham sandwich in every bottle so a friend once told me.

Burner Improvments

Posted: December 19, 2011 | Author: | Filed under: Arduino, Homemade Boiler, LCD display, Testing | Tags: , , , , , , | Leave a comment

A friend and excellent engineer visited over the weekend and between us we decided to improve the burner a little.  The first change we decided to make was to add some insulation.    I measured the temperature around the outside of the boiler with a non contact thermometer at approx. 350°F in the area of the firebox.  The mounting plate that holds the burner was approaching that temperature as well.  The air box was lower but still this is an excessive temperature.  The Auger pipe was solid from the hopper to the burner unit and since I have both 4″ pipe and 4″ tube we decided to make a thermal break in the auger feed for additional safety.  The 4″ pipe even though it is surrounded by the air box eventually gets warm and since the feed auger has a fair amount of room between the auger and the pipe there is a certain amount of fuel that remains in the pipe and at shut down this can smolder.  So to remove this problem and make the unit more safe a redesign was initiated. Adding  insulation between the air chamber and the burner with the addition of a thermal break prompted us to take the unit apart, check it over and see how everything was faring as well as make improvements.  But of course after the burner and hopper were cut apart and on the bench more improvements were noted. Most of the improvements now fall into minor design for manufacturing type areas, maybe a little less welding and a little more tabbed nut and bolt assembly so minor changes can be made more quickly.  Of course being able to pull the auger feed away from the burner assembly without unbolting anything will be a big change and improvement.  I am going to make the air box bolt on as well.  Should be reassembled for another test on Wednesday.

Of course it wouldn’t be a weekend if we didn’t play with the software.  We added a For loop to the thermistor function to improve the accuracy.  I added an array to smooth the results using a moving average.  But most importantly we found the lingering problem with the LCD characters being garbled.  It was a wiring issue.  Now fixed it has run 24hours without a problem and I am confident it will stay fixed now.  The next step will be to add a capacitor if the problem resumes.  I am quite confident it will not be a problem however since it looks more solid even.  There is less flickering and more solid character display.  So all in all a fun and productive weekend.

Chip boiler Project

Posted: October 24, 2011 | Author: | Filed under: Homemade Boiler | Tags: , , , | 5 Comments

Hi!  I decided to write a blog about the fun things I like to do and how it I like to apply those things to my life.  I believe a balance is important, I feel it when I don’t have enough of something, exercise, money, sleep you name it.   My goal is to do something about all of those things and more with a welder, an Arduino application and a sense of humor.  My latest project is a homemade chip boiler that can burn either wood chips or pellets.  The plan is simple, develop a boiler to heat the entire house on the cheap.   The brains of the system is to be a Arduino microcomputer to control the boiler and the rest of the house in parallel with the existing oil fired boiler.

So the project is really split into two parts, the welding and design of the boiler and the control of the existing system and new boiler.  The chip boiler is a continuous burn unit probably producing 20-30k BTU.  Initial tests indicated 20-30k, I did these tests in the open air by weighing a pan of water and timing the time to boil.  This was a very crude method so the prototype boiler may yield different results.  The existing oil fired boiler is rated at 130,000 BTU.  So to get the two systems to work together will require a different paradigm, one requiring the circulator  pumps to work more intermittently and often .

But enough about the control theory for today,   The prototype boiler is 90% welded up and has been tested  for leaks.   The boiler was started from an over the road truck’s fuel tank.  The internal seams were never intended to be water tight and I am having trouble with welding up the all the internal weeps.    The tank under my house’s water pressure of  about 45 psi weeps,  I am intending to call and get some information on tank sealing paints today.  After a brief internet search I have seen several sealants that are intended to work with gas tanks for car restoration.  I plan to call and see if they will work with a water application  If this seems possible and good I plan to move onto the Arduino control application since I will no doubt be waiting a day or two for the materials to arrive and then apply the materials to the tank and wait the appropriate drying time.  Please feel free to weigh in on any suggestions on sealing the tank.