Start of a new Burner Design

Uncleaned burnerA friend with Solidworks has offered to draw up a new burner, so I thought I would post a few pictures of the old burner to help with dimensions.  Here’s a picture of the uncleaned burner with about two inches of ash build up in the bottom of the burner.

 

Side view uncleaned burner with tape

Side view uncleaned burner with tape

The tape measure in this view gives a little help with size.  Originally the back flap was designed to help with air flow a sort of chimney effect, however this was of limited help and probably helped trap ash as do the high sides.

Top view showing hole size

Top view showing hole size

The larger holes are 1/2″ and the ash still doesn’t fall through unless stirred.


HDD vs. Pellets Update

It’s been a cold ride here in New Hampshire for a few weeks. However, like a campfire, on average we may end up less than average on HDD’s for the month. I say like a campfire, because it always seems that one side is too hot and one too cold to really enjoy it, however on average….It’s raining hard here today, so once again the snow is leaving. This will ruin the skiing and winter sports and yet it’s really too cold to enjoy summer sports. Winter in Northern New England has become a lot like southern New England. But that’s a different topic.

HDD vs. Pellets Mid January

The pellets seem to be a pretty steady 14HDD per bag. And so a ton this time of year lasts about two weeks, maybe a little longer. We bought our first ton this year, I was using up old stock and we bought a ton from Tractor Supply, their brand. I am liking them a lot, they seem to not cause any ash build up problems at all. I will buy them again. If you add up all the bags used and divide by 50 bags/ton we are at 4.22 tons heating season to date, for a total cost of $947.39 at the cost of $224.50/ton.


2013 in review

The WordPress.com stats helper monkeys prepared a 2013 annual report for this blog.

Here’s an excerpt:

A New York City subway train holds 1,200 people. This blog was viewed about 7,200 times in 2013. If it were a NYC subway train, it would take about 6 trips to carry that many people.

Click here to see the complete report.


HDD’s vs. Pellets Part 3

The HDD’s reported from Weather Underground was 324 for the week of December 8-14 and I used 24 bags of fuel, more than would have been calculated by a simple ratio based on last weeks fuel usage, however very close to the trend line of the original scatter plot which I will post again here.  So as time goes on the prediction gets a bit better.  HDD vs. Pellets 2nd week December

It’s shaping up to be about 13.5 HDD’s per bag of pellets, I have made minor changes to the software so, I think these numbers are getting more stable as time goes on. Note that December 2012 for the first two weeks added up to 431 HDD compared to December 2013’s first two weeks 548 HDD.


Minor Software changes can make life much more convienient

DSC00698This time of year in New Hampshire it is warm days and cool nights.  Pleasant for the most part but it is still fall.  There can be some rainy raw days that need a touch of heat and to heat the hot water or maybe the day is warm enough but just cloudy so you want to heat the hot water for showers.  So in other words the boiler can often run for 3-4 hours per night, maybe one or two evenings per week.

Shutting the unit down before the upgrade consisted of unplugging the unit which includes all the controls except the draft fan.  This of course shuts off the feed and everything else but the fire still burns the remaining fuel.  I keep the draft fan on to minimize any smoking that might occur otherwise.  I live on the second floor of the building and the boiler is on the first floor so typically I would walk down unplug the unit, take a shower and then go back down and unplug the draft fan.  More than once I have had to go down later after forgetting to unplug the draft fan.  So I added a physical button, the Attn button, to the front of the control panel, and rewired the control box to relay control the draft fan.  Now with a minor software change made I can go down hit the button and the unit shuts the auger feed immediately and then after twenty minutes turns off the relay for the draft fan.  It’s so cool my girlfriend wants to go push the button.  Can life get any better?


Fire!

Well of course there’s fire in the burner that’s how it works. After today however the Arduino should be able to sense the fire since I added a photo resistor,  commonly known as a flame sensor, bought at a furnace supply store. With the Arduino’s ability to sense flame, the addition of automatic self starting should be enabled.  The ability to determine if fuel is building up should also add safety to an already proven safe unit.

The sensor I obtained is a flame sensor used in a normal oil or gas fired burner.  The flame sensor allows me to sense the light corresponding to a fire currently burning. The sensor cannot determine if the fire went out or if the flame sensor can no longer see it but functionally it makes no difference to me.  I am interested in either condition and the response is the same to both conditions, turn off the fuel feed.    If the fire went out, no need to keep feeding fuel, that will simply clog the  feed chute and make a mess.  If the fuel has backed up the feed chute so much as to shield the flame sensor, there is excess fuel, turn off the fuel feed.  Physically the sensor is mounted to “look” through the back of the feed slide.  This positions was chosen purposefully to determine if fuel was backing up.

Because the flame sensor is a resistor, I am using a voltage divider circuit to measure the voltage and then using the software to check the voltage with a if – then statement.  The software determines if the voltage is high enough to indicate flame or too low indicating dark.  I have been  recording various sensor data to the micro SD over the heating season, so I will record the voltage overnight and we can see the range of data tomorrow.  If anything this should be a good time of year for the test since the fire is needed to maintain the temperature in the building, it is mid 30’s F here today, but the fire is not required to be too vigorous since the temperature is not extremely cold.

Pictures and data to follow.


Fuel savings built into the software

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