G
Goldspoon
Longish post that may only be of interest to some...
I am very interested in wood burning stoves with back-boilers and the plumbing of. I have had a fair bit of experience now working on a number of systems.
Gravity systems are interesting and fairly straightforward. Thermal stores and Dunsley Neutralisers make life easier when integrating woodburners, boilers, pumped radiator circuits etc.
But things can get interesting when one is attempting to add wood burner gravity circuits into existing circuit designs - circuits that include, say, oil/gas boiler, pumps, standard vented cylinders etc. Circuit design in these situations is what I'm getting at - and moving on from this a desire to work out what paths water will take prior to doing the plumbing so it does not all go pear shaped.
Example to start with:
Standard wood burner gravity circuit works fine...
Radiators and pump added in this next pic. Question is, a simple one here, "which way will the water flow?"
I know this one because I was involved with the fitting and it worked as so:
SPOILER
.
.
.
.
.
.
.
.
.
.
.
.
.
.
Note that flows at x and y switched direction from the pre-pumped days. I know that this happened but I was a little surprised at the time as I thought that the pump would steal from the prinmary circuit but not affect it.
Thinking about this I deduced that when you pump water toward a "T" then it will "hit a dead end" and divert left AND right unless some other force is powerful enough to stop it doing so (in this case gravity isn't).
I recently met a very complicated spaghetti of a system and in this system there were multiple such junctions where water did not follow this rule on all ocassions (it physically could not as you will see). This led me to thinking about how, when one is "adapting existing systems" how one can determine water flow using the mind rather than "try it and hope it works".
The system was something like the following (this is fictitious as did not detail the system at the time):
Both the oil boiler and the fire worked on gravity - both heating the cylinder.
The pump for the rads kicked in as determined by a room stat (oil) or pipe stat (woodburner).
The assumption then is that at junction C water goes left and right. Following this assumption one can determine most other flows and returns (for example the pipe just above A just HAS to be flowing North on the picture).
Assuming my initial assumption is correct (is it???) then how do I detemine what direction the red bit flows?
Junctions B & D cannot follow the "go left and right at a T junction" because they then conflict with each other (you get two flows of water colliding)... themn again may be that happens and you get a stagnant area of water; or an area where one flow just dominates slightly with some kind of advantage (e.g. convection).
Junction A is also interesting. Water is being pulled from the T. Is it a likely rule that water pulled from a T pulls water in from left and right the same as the other rule but in reverse?
Anyway... I am in danger of being accused of having nothing better to do I'm sure
but any thoughts from wise and experienced forum members...
I am very interested in wood burning stoves with back-boilers and the plumbing of. I have had a fair bit of experience now working on a number of systems.
Gravity systems are interesting and fairly straightforward. Thermal stores and Dunsley Neutralisers make life easier when integrating woodburners, boilers, pumped radiator circuits etc.
But things can get interesting when one is attempting to add wood burner gravity circuits into existing circuit designs - circuits that include, say, oil/gas boiler, pumps, standard vented cylinders etc. Circuit design in these situations is what I'm getting at - and moving on from this a desire to work out what paths water will take prior to doing the plumbing so it does not all go pear shaped.
Example to start with:
Standard wood burner gravity circuit works fine...
Radiators and pump added in this next pic. Question is, a simple one here, "which way will the water flow?"
I know this one because I was involved with the fitting and it worked as so:
SPOILER
.
.
.
.
.
.
.
.
.
.
.
.
.
.
Note that flows at x and y switched direction from the pre-pumped days. I know that this happened but I was a little surprised at the time as I thought that the pump would steal from the prinmary circuit but not affect it.
Thinking about this I deduced that when you pump water toward a "T" then it will "hit a dead end" and divert left AND right unless some other force is powerful enough to stop it doing so (in this case gravity isn't).
I recently met a very complicated spaghetti of a system and in this system there were multiple such junctions where water did not follow this rule on all ocassions (it physically could not as you will see). This led me to thinking about how, when one is "adapting existing systems" how one can determine water flow using the mind rather than "try it and hope it works".
The system was something like the following (this is fictitious as did not detail the system at the time):
Both the oil boiler and the fire worked on gravity - both heating the cylinder.
The pump for the rads kicked in as determined by a room stat (oil) or pipe stat (woodburner).
The assumption then is that at junction C water goes left and right. Following this assumption one can determine most other flows and returns (for example the pipe just above A just HAS to be flowing North on the picture).
Assuming my initial assumption is correct (is it???) then how do I detemine what direction the red bit flows?
Junctions B & D cannot follow the "go left and right at a T junction" because they then conflict with each other (you get two flows of water colliding)... themn again may be that happens and you get a stagnant area of water; or an area where one flow just dominates slightly with some kind of advantage (e.g. convection).
Junction A is also interesting. Water is being pulled from the T. Is it a likely rule that water pulled from a T pulls water in from left and right the same as the other rule but in reverse?
Anyway... I am in danger of being accused of having nothing better to do I'm sure
but any thoughts from wise and experienced forum members...
