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Attempting to run a Chinese Diesel Heater on a peristaltic pump controlled by an Arduino Uno

https://tube.tchncs.de/w/pqzu9KEVZBQt9GX4roUmnQ

My goal is to replace the loud clicking fuel pump that comes with pretty much every Diesel heater, be it from Eberspächer, Webasto, Autotherm (Planar) or from China. Autotherm offers a improved piston pump for a hefty price tag. But also that pump remains a clicking pump. My idea is to use an inexpensive peristaltic pump that is easy to service and cheap to replace, if needed. Unfortunately I ran into a problem with the temperature control element of the Diesel Heater, after my first test with the peristaltic pump. The Diesel heater did run with it for a few minutes, but gave an error after I attempted to start it for a second test. Apparently I had overheated the thermo-fuse since the air was not guided over the cooling ribs of the heater, without the housing, during my test. Possibly I may have overheated the little Chinese Diesel heater by pumping too much fuel into the burning chamber with the peristaltic pump, running at the same pumping frequency as the piston pump. To be able to continue with my project, before the new thermo-fuse arrives from China, I started testing the feasibility of replacing the original Diesel Heater controller with an Arduino mini computer. In this video I will show the first steps with the Arduino on the Chinese Diesel Heater. To be continued in following videos.

Given how many van builds use diesel heaters, I thought this video might be interesting to share.

Bonus: Peertube is to YouTube, as Lemmy is to Reddit, and Mastodon is to Twitter.

1 comments

HaphazardFinesse

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That's a neat idea! I initially thought he was going to use an Arduino to control the whole heater haha, guess he's just using it to convert the pulses from the diaphragm pump leads to PWM for the motor, essentially.

However, I don't know if a peristaltic pump is the best solution for this. First off they're not particularly reliable. I work with Stratasys 3D printers that use peristaltic pumps pretty extensively as first-stage pumps, and they break all the time. Good news is they're cheap and easy to replace. Don't know if I want to be crawling under my van in January at 3AM to replace a pump though lol.

Which leads to my second concern: Most vans have their pumps mounted externally, so the tubing the pump compresses would be subject to the cold, probably not great for it.

And three: flow rate can be difficult to accurately control. Especially at the low flow rate needed for a diesel heater. If you look at his pump towards the end of the video, and think about the internals of the pump, at the rate shown, it will rise in pressure for about 5 seconds, then drop to no pressure for like a full second, maybe even a slight negative pressure (from the pump arm disengaging the tubing, before the fluid from the next arm moves up to fill the void.

Now I'm admittedly naive about the internals of diesel heaters, but I'm pretty sure there's nothing in between the external pump and the combustion chamber nozzle to regulate the pressure, so a full lose of pressure from the output of the pump for >1 sec could cause flame failure.

Don't get me wrong, I'd love to get rid of the diaphragm pump, I also hate the clicking haha. Just think we'd need something with more precise flow rate control at that low a level.