Question with respect to the velocity of the pump

the velocity of pump affects the velocity of circulation. these are to the decrease of delta supply -. in the general case this increases heat emission as a whole, decreases occurence of cycles, is increased inertness and so forth

[Dennec]

If we formulate otherwise, then on the velocity of pump directly depends heat exchange before the heat exchangers of pocket and before the space heaters (the higher the velocity of pump the better goes the heat emission). Therefore all producers recommend work against THE III velocity. Is sometimes feasible transition down THE II velocity (if narrowed diameters and appears characteristic noise of water), but on the whole that work against the underestimated velocities is undesirable, since superheating primary heat exchanger is feasible.
P.S. is worse heat emission - lower than efficiency - above gas flow

[Yorej]

Thanks to specialists at the point of the responses

[Glej]

A question what velocity does set producer on the pocket Of immergas Of nike Of star 23 kW? It must be -3, and in reality? Down this question they for some reason always give the uncertain response.

why there are doubts? switch based on the plant before other position never saw…

[sondymon]

Reducing the velocity of pump to everything we we can artificially obtain situation “weak circulation” which it is characteristic for the heating systems with the great loss of head.
I.e., because of the fact that coolant flow rate through the heat exchanger of pocket is decreased, pocket is capable more rapid “to warm thoroughly” this water. In practice is received that pocket it was included, it rapidly achieved the necessary temperature of the supply (due to the low expenditure of water, i.e., “slower flow- more strongly it is heated”) and it is turned off and the following start only in 3 minutes.
Thus pocket does not manage to move out down modulation, indeed for modulation at the point of pocket it is necessary to work continuously about 10 minutes.

[Vjacxeclav]

sandyman wrote:
...... Thus pocket does not manage to move out down modulation, indeed for modulation at the point of pocket it is necessary to work continuously about 10 minutes.





Modulation here not with what, since these of the first ten minutes the pocket works on the minimum and it is, correspondingly, lower already nowhere .......
This time can be shortened, or entirely retracted when desired.
It is agreeable with the remaining.

[Dennec]

Well it is possible to still add that booster duration for each pocket different, but this already of detail.

[J.Forfum]

Denis
if pocket does not leave down the accident on the superheating (in each specific case), the issue of the velocity in this connection disappears.
Further, heat emission - communications, - it is agreeable. But TO WHAT EXTENT before the numbers will be changed for the sake of efficiency the gas flow upon transfer based on the 1st velocity to the 3rd (or vice versa?) Dependence is what - linear, exponential or vice versa- exponential? If economy will be 1%, then there is no meaning to turn motor against the 3rd velocity, that more taking into account the heavy expense of electric power
Me seems, principal meaning in increases in lifting power - if system works with a great drop in the heights and it is necessary to raise heat carrier down the level of the 2nd or 3rd deck.
Or I not laws?
Of j.Forfun (2007-07-1742:44: 50)

[sondymon]

The difference of heights before the closed system with the pump does not play role. The pump head is spent only beyond overcoming of friction and local resistance of the type the " tees " of narrowing and so forth… In other words for the pump, the riser 6 m with a diameter of 3/4 this also that also horizontal tube with the length of 6 m and with diameter 3/4.

[J.Forfum]

sandyman wrote:
The difference of heights before the closed system with the pump does not play role. The pump head is spent only beyond overcoming of friction and local resistance of the type the " tees " of narrowing and so forth… In other words for the pump, the riser 6 m with a diameter of 3/4 this also that also horizontal tube with the length of 6 m and with diameter 3/4.
I surely actually something do not understand… Really by pump with the power of 50 it is possible to raise fluid down ANY height and still and with one and the same by pressure??? It went to read before the net of the foundation of hydrodynamics, when I am X-rayed - I will return…: -)

the basic task of pump - to ensure the necessary duct of heat carrier both through the pocket and through . what it must be? with the detachment is examined this parameter, as the heat losses of building and on the basis of it is regulated the necessary maximum power of pocket. I will not again exhaust by formulas, but does not compose the labor to calculate on how much it will be raised the temperature of heat carrier, if pocket works against the preset power and the velocity of heat carrier is known. in this case is examined normal delta on the heat exchanger of ~20 of degrees. this is the necessary condition for the pocket. by another language: pump must manage to devote from the pocket the heat- being separated.
and the velocity of heat carrier directly depends on hydraulics , i.e., what scheme , diameter and length of tubes, the quantity of turnings and the rest all that which " prevents” pump from pumping through heat carrier.
accordingly based on this the power of circulating pump is driven out (or it is changed). moreover the minimally necessary parameters are driven out. it is understandable that the higher the velocity of heat carrier, the more easily it is to work to pocket and the higher the heat emission as a whole.
therefore there is no meaning to change the velocity of pump down the smaller side. perhaps only in the apartment and that…

[J.Forfum]

That you wrote everything now - understandably and it was agreeable with this, only this must be estimated quantitatively, to know for which to struggle (not at the point of 1%). But that before this
In other words for the pump, the riser 6 m with a diameter of 3/4 this also that also horizontal tube with the length of 6 m and with diameter 3/4
- as yet no.





The work of any pump is characterized as far as the following values:
Volumetric supply - Q, 3/] - the capacity of fluid supplied for the sake of pump down the delivery conduit at the point of the unit of time.





Frequency of rotation (for the pumps of those having the rotating rotor) - n
Condition of medium against the entry: (temperature and pressure); the density of medium - /3]
Power, N - total energy applied to the pump per unit time.
Efficiency efficiency, relation of the total energy, supplied down the pump, down the energy of the transmitted fluid.

[sondymon]

to J.Forfun
Do not spend your time beyond the searches for pump performance and comparing them with the height of riser. Verify me as to design and planning engineer in the past. Two-funnelled heating system with the forced circulation has 2 risers. One raises heat carrier down 2 decks (for example) and second precisely the same next lowers. In this case the effort to spends pump on the of heat carrier down the height at the point of an example 6 m it is compensated by the fact that before the adjacent riser heat carrier it moves down and as it " returns” expenditure for . Heating system can be compared with the wheel.
Mental experiment, turn over bicycle upward by wheels. You wheel, you will spend force beyond overcoming of inertia and then when wheel it will untwist you zh you do not spend force on the of half of the circle of wheel, you simply compensate bearing friction of wheel and friction against air ") I from that is how is well lubricated bearing they depend the expenditures of your physical force, i.e., the accelerated wheel can be pushed by finger on a good bearing and can be with the pulled by , also, without oil.
The same before the heating system, pump supports the rotation of heat carrier before the circle and from that how great a losses down the friction and the local resistance will be before the system it depends its necessary power. (Pump it is characterized as far as diagram “pressure- expenditure)
In this case it is accepted to express pressure before the meters of the water column, for the reference 1.. equal to nearly 0,1 bar or 10 kilopascals.
The maximum head of the pump of the pocket (for example let us take Mini of 24kw) is equal to 1,8-1,9 it .. with the expenditure of 1000 liters per hour. (with the expenditure of 1000 liters per hour pocket against the nominal yield of to water down 20 degree, i.e., those cherished 80/60)
And the height of riser would play role that pump never it could raise water down the second floor. here are such here pirogs. Arrive before us to Kiev I will present down for the detachment of hydraulics of heating systems

[J.Forfum]

: -) Thanks.

[Glej]

But if before the system of 400 of water, and system was done under another of + of 2 , is received water they heated it was banal across the system thus far downy to end- lost + plus of 2 wings of heating (where I wish, there to run). There is a role of the velocity of pump?

it is possible batteries by blankets to wrap that it did not cool
if it is serious, then velocity must be maximum. but here this matter: two or three emergency discharge and with hard water can the heat exchanger of completely
read my signature

[Glej]

Is intended by me the case? But before others perhaps not it ? I.e., before the heat exchanger must be water constantly (or other)?
of grey (2607-07-2627:08: 13)