Calorifier......2 coils but 3 possible heat sources

[peterboat]

i have in my boat a rayburn royal stove engine and wispergen all of the coolants run into a heatstore which is basically a 120 litre hotwater tank it has multiple entries and exits for the coolant above it i have my hot water calorifier so no mater what i use in the boat it heats water in the heatstore which by thermo siphon then heats the hot water. when the coolant in the heat store reaches 50 degrees it turns on the central heating pump which heats the boat. the advantage of this system is no waste energy if i use the water in the calorifier the heatstore reheats. i have had the system for nearly a year and i am very pleased with it

Edited November 26, 2015 by peterboat

[Loafer]

Here's a diagram of the system that I fitted to Theodora in 2007. We have a twin coil calorifier but only one is used and is OK. There would be a small advantage in putting the other coil in series (or parallel for that matter) as it would increase the area for heat transfer and make the calorifier heat up more rapidly.

Nick

 

Theo, I took the time to put MY two coils in series, after removing one of my heating sources and freeing up a coil. The engine alone fed the new series pair. I have to say that I noticed NO difference in how long it would take for the engine to heat the water.

 

I can only surmise that if those coils are decently sized, then just one of them will take all the excess heat out of the water. If that water then goes into a second coil, I'd make sure that it was the bottom one, where the cauliflower water is cooler than that in the coil.

 

Possibly. It probably doesn't make any difference theoretically, unless each coil was really pathetically small.

Edited November 26, 2015 by Loafer

[David Mack]

Aren't they the same thing? I thought that a stop cock was a gate valve with a straight through flow and a stop tap was used a washer and vlave seatiing with a wiggly path for the water.

 

But I am not a plumber and could easily be wrong.

 

Nick

Stopcock: indirect path, rerstricted flow, rubber seal

 

Gate valve: direct path, full bore, metal to metal seal

 

[WotEver]

Stopcock: indirect path, rerstricted flow, rubber seal

 

Gate valve: direct path, full bore, metal to metal seal

 

Brilliant, thanks ?

[Theo]

Obviously they look different but out of curiosity what is the internal difference?

 

I stsnd corrected. The plumber wot told me when I were a nipper was to blame!

 

Internally the gate valve has a machined tapered recess into which a sliding tapered gate accurately fits. When open there is a straight path for the water. The shaft has a left hand threaded section to it which goes into the gate. Left hand thread so that when you turn it clockwise the gate is pushed into the recess to close it.

 

The stop cock has a circular seat onto which a rubber washer is forced by turning the tap. It works just like the tap on the kitched sink. It is not as good for low pressure because the water, on entering, has to turn a right angle to flow up through the circular seat ant then another S shaped path the resume it couse in line with what it was doing originally.

 

N

[Loafer]

Saw a sign once, next to a stop cock.

 

It said 'STOP COCK'.

 

On it, someone had written 'OK, MATE!' underneath.

 

Well I thought it was funny...

 

ETA if it isn't funny, put an imaginary comma after 'STOP'!

Edited November 27, 2015 by Loafer

[Theo]

 

Theo, I took the time to put MY two coils in series, after removing one of my heating sources and freeing up a coil. The engine alone fed the new series pair. I have to say that I noticed NO difference in how long it would take for the engine to heat the water.

 

I can only surmise that if those coils are decently sized, then just one of them will take all the excess heat out of the water. If that water then goes into a second coil, I'd make sure that it was the bottom one, where the cauliflower water is cooler than that in the coil.

 

Possibly. It probably doesn't make any difference theoretically, unless each coil was really pathetically small.

 

It will only make a difference if like me you have a heat source which too powerful for the heating area of a single coil. Whne heating just the calorifier the return to my Mikuni is hot enough to cause it to go on to low power and the wter heats slowly. With the two coils in series the returning water has time to transfer its heat and returns to the Mikuni cooler. The Mikuni keeps firing at full power and the water gets hot quicker.

 

In the second paragraph you have the right idea I am sure but make sure that your cauliflower is not overcooked.

 

N

Saw a sign once, next to a stop cock.

 

It said 'STOP COCK'.

 

On it, someone had written 'OK, MATE!' underneath.

 

Well I thought it was funny...

It is. I am still chuckling.

 

N

Stopcock: indirect path, rerstricted flow, rubber seal

 

Gate valve: direct path, full bore, metal to metal seal

 

Pictures are worth loads of words and much clearer!

[Loafer]

 

 

In the second paragraph you have the right idea I am sure but make sure that your cauliflower is not overcooked.

 

 

Noted, thanks chum - but it isn't. There's no discernible change from just using the original single coil.

[dianamay]

I`ve always assumed that the cooling system on a engine had the duty of preventing an engine over heating but was also designed in such a way that the engine ran at maximum efficiency. If the returning water is too cool would that compromise that efficiency?

[Theo]

I`ve always assumed that the cooling system on a engine had the duty of preventing an engine over heating but was also designed in such a way that the engine ran at maximum efficiency. If the returning water is too cool would that compromise that efficiency?

 

My old BMC 1.5 has indirect raw water cooling. If it is run without any of the external circulation open it will be just like an engine with unmodified cooling. The engine circulation is controlled by a normal thermostat. In the winter the thermostat will not open as far as it would in the summer so in the winter the returning water will be really cold. So the temperature of the returning water is whatever it happens to be and is not controlled.

 

N

[Scholar Gypsy]

I`ve always assumed that the cooling system on a engine had the duty of preventing an engine over heating but was also designed in such a way that the engine ran at maximum efficiency. If the returning water is too cool would that compromise that efficiency?

 

On my engine the bypass circuit feeds the calorifier. The boat builder did not want to put radiators etc on that circuit as that could lead to over-cooling.

 

Once the thermostat has opened you can stick as many heat sinks on as you like, as the thermostat will adjust the flow to produce the right temperature for the engine.

[George94]

I`ve always assumed that the cooling system on a engine had the duty of preventing an engine over heating but was also designed in such a way that the engine ran at maximum efficiency. If the returning water is too cool would that compromise that efficiency?

 

No. If the coolant coming out of the engine is too cool, it will be routed back round the engine until the right temperature is reached.

 

If you have a load of cool radiators, the thermostat will make sure that the engine is hot enough before sending any coolant their way.

[Theo]

 

No. If the coolant coming out of the engine is too cool, it will be routed back round the engine until the right temperature is reached.

 

If you have a load of cool radiators, the thermostat will make sure that the engine is hot enough before sending any coolant their way.

 

That doesn't happen on my BMC 1.5. The outlet for the heater circuit is taken directly from the top of the cylinder head. The return goes into thje bottom radiator hose. This means that the circulation through the heat sinks is unaffected by the state of the thermostat. The danger here is that there is a theoretical possibility that the heat sinks could take too much heat out of the engine which would never reach its proper working temperature. In fact this is not a problem on Theodora. I used to leave the circulation turned off until the engine was up to full working temperature but a bit of experimentation showed that this made almost no difference to the time it takes to heat up.

N

[Loafer]

Does anyone know if there's a thermostat in me BD3? I can't see where one would go!

[MtB]

Does anyone know if there's a thermostat in me BD3? I can't see where one would go!

 

 

I'd say its a racing certainty there's one in there somewhere.

 

How long does it take to good and hot if you start it and let it idle, say for battery charging? Anything less than about 45 mins and you can be certain there is a thermostat.

[Loafer]

 

 

I'd say its a racing certainty there's one in there somewhere.

 

How long does it take to good and hot if you start it and let it idle, say for battery charging? Anything less than about 45 mins and you can be certain there is a thermostat.

 

BD3Bill just told me there is, and roughly where it is. I'd say around 35 mins at 1/4 throttle or 4-500 rpm just charging. (Idle is 250, max 1200)