Build Daily

August 12, 2017 18:06

Gidrostrelka heating

heating system - it is a complex "organism" for the effective functioning of which is required to achieve maximum coordination, balance the work of all its elements.To achieve this "harmony" - is not so easy, especially when a complex system, extensive, including several circuits, different and on the principle of works, and temperature conditions.In addition, the individual heating circuits of heat transfer devices can have their device automatically adjusting and maintenance work that its intervention should not affect the functionality of the "neighbors".

Gidrostrelka heating

Gidrostrelka heating

There are several approaches to achieving such a "unison", but one of the simplest and most effective ways is very simple, but very effective device - hydraulic splitter, or as it is more commonly called, gidrostrelka heating.What is this element of what how it works, how to properly calculate and mount - in this publication.

What is the low loss header to the heating system

Article Contents

  • 1 What is the low loss header to the heating system
  • 2 How does a hydraulic separator
    • 2.1 Video: Animateddemonstration of the operation of the hydraulic separator
  • 3 specifics of design of the hydraulic separator
  • 4 calculation of the standard hydraulic separator
    • 4.1 calculation of the power of the heating system
      • 4.1.1 Calculator recommended parameters for power and difference gidrostrelkitemperature
    • 4.2 gidrostrelki calculation parameters based on the performance of pumps
      • 4.2.1 Calculator gidrostrelki parameters based on the performance of pumps
  • 5 Conclusion
    • 5.1 Video: How important gidrostrelkabranched in the heating system?

To understand the purpose gidrostrelki, let us remember, as a general working autonomous heating system.

  • The simplest system with forced circulation can be represented as follows.
The simplest single-circuit heating system

simplest single-circuit heating system

scheme is shown with more simplification.Thus, it is not shown in the expansion tank and the elements of the security group, simply for reasons of "relief" pattern.

K - boiler heats the coolant.

N1 - circulating pump, thanks to the work which coolant moves through the pipes supply (red lines) and "the return" (blue line).The pump can be mounted on a pipe or to be included in the design of the boiler - this is especially characteristic for wall models.

In embedded heating radiators closed loop pipe (RO), providing heat - thermal energy is transferred to the coolant in the premises of the house.

With proper selection of the circulating pump performance and create the pressure in the simplest single-circuit heating system, it may be sufficient in a single copy, and the special needs and there seems to be to install additional devices.Will comment on the matter - a little later.

2016-03-02_193434 circulation pump - the most important element of the heating system

Although there are schemes with natural circulation of coolant, should still install the circulating pump - this will boost the efficiency of the heating system.How to choose circulating pump for heating , how to calculate the optimal parameters of the device - in a special publication of our portal.

  • For a small home a simple circuit can be quite enough.But the building more often have to use several heating circuits.Complicate the scheme.
Cope if one pump with multiple loops ?Not a fact ...

Cope if one pump with multiple loops?Not a fact ...

This illustration shows that the pump provides movement of the coolant through the manifold (Cl), where it is broken down into several different circuits.It can be:

- One or more high-temperature circuits with conventional radiators or convectors (PO).

- Water heated floors (ECP), which has the coolant temperature should be much lower, so will involve special thermostatic device.Sensor length underfloor heating circuits also usually exceeds several times the normal radiator layout.

- home security system with the installation of hot water boiler of indirect heating (BKN).Here - quite special requirements for the circulation of coolant, as is usually the change in the flow of coolant flowing through the boiler is regulated and the heating temperature of the hot water.

cope if our only pump with such a load, with a flow rate of the coolant?Probably not.Of course, there are models of high performance and power performance with high pressure generated but not unlimited possibilities and of the boiler.Its internal heat exchanger and the tubes are designed for a certain performance and generated pressure, and these values ​​inflate - must not be, as it might lead to failure of the expensive boiler system.

Yes, and the pump itself, if it is run continuously at the peak of their capabilities, providing all the coolant circuits branched system hardly last a long time.This is not to mention even of increased noise power equipment and considerable power consumption.

  • What is the solution - installed on each circuit own circulating pump, calculated the parameters of its "subsystems", which he serves.
The work of several pumps requires mandatory harmonization , otherwise the system will be unbalanced

of multiple pumps requires mandatory harmonization, otherwise the system will be unbalanced

So, for each of the circuits set their own pump.Problem solved?Alas, this is not true - it just turned into "another plane," and even worsened!

that such a system was stable, requires very precise calculation of pumping equipment.But even this is not likely to make such a complex scheme of equilibrium.Pumps are usually linked to thermostatic control systems of each of the circuits, that is, their current, at the moment, performance - value changes.One circuit suspends its work, the other, on the contrary, is included.Not excluded variants simultaneous operation or, conversely, temporary downtime of pumps.Circulation in the loop may create one inertial "parasitic" coolant moving to another, where it is currently not required - and so on, various options can be done.

As a result, it often leads to unacceptable overheating of warm floors to the uneven heating of various premises, to the "blocking" of contours and other negative phenomena, which nullify the efforts of the owners to create a highly efficient system.

And worst of all, in this case the pump installed near the boiler - all parameters of the system instability is primarily reflected in his work, and ultimately - to "razdergannom" not susceptible to precise adjustment operation of the boiler.But often in large houses set in cascade two or more boilers - management by such a system it becomes generally extremely difficult, almost impossible task.All this causes rapid wear of expensive equipment.

  • A yield turns out to be quite simple - it is necessary to divide the entire hydraulic system is not only the contours of the final consumption, through the collector, but also to allocate a separate boiler circuit.
balancing problem is solved by installing a hydraulic separator ( gidrostrelki )

balancing problem is solved by installing a hydraulic separator (gidrostrelki)

It performs this function and hydraulic hand (TOS).This simple device is installed between the boiler and the collector.

correct full name gidrostrelki - hydraulic splitter.Arrow called it, apparently because it is capable of redirecting hydraulic coolant flows, balancing of the whole system.

Construction gidrostrelki usual - very easy

design gidrostrelki usual - very easy

Structurally, this element is a hollow tube of circular or rectangular cross section, switch off at both ends, with two pairs of nozzles - output, supply, and input - pipe "the return."

In fact, formed two related but, in fact - independent of each circuit: small kennels and large boiler, comprising a collector with all the ramifications of the remaining contours.In each of these two circuits, and a flow rate of coolant flow, which do not have any significant effect on each other.Usually figure Q1 - the value of a stable, as the boiler pump runs constantly at one speed, Q2 - changing the course of the ongoing work of the heating system.

In essence , the system is divided into small and large loop boiler - a heat exchange devices.

In fact, the system is divided into small and large boiler circuit - with heat exchange devices.

Pipe diameter is selected so that the site was created low flow resistance, which allows to align the pressure in the pulmonary circuit, put it, regardless of job or job idle circuits.In general, this leads to a balanced work of each of the sections of the heating system, for a smooth, not subjected to pressure surges and temperature operation of the boiler equipment and the system as a whole.

How does a hydraulic separator

Basically, there are three possible modes of operation of the hydraulic separator.

Illustration Description mode gidrostrelki
Sit 1 It - almost perfect, the equilibrium state of the system.
Head created a small boiler circuit pump is equal to the total pressure of all heating circuits (Q1 = Q2) .
temperature at the inlet and outlet flow equal (t1 = t3) .
The situation is similar in the nozzles "the return» (t2 = t4) .
Vertical movement of the coolant is minimal or even non-existent.
In practice, such a situation if it occurs, it is extremely rare, occasionally, because of the heating circuit parameters tend to change periodically.
LED 2 second situation.
total coolant flow rate in the heating circuit exceeds the same indicator of the pump boiler (Q1.
In fact, can be described so that the "demand" for water is greater than that which can "suggest" boiler.
situation is quite frequent when both are involved most. contours
In this case, a vertical upward flow from the nozzle of the return of a large circuit to the nozzle flow Moving upward vertical flow is mixed with the hot coolant coming from the boiler
Temperature: t1 & gt; t3, t2 = t4
3 screens situation is diametrically opposite - flow in the small loop (without changing nominal) became higher than the total in heating circuits (Q1 & gt; Q2)
«Offer» exceeded the "demand" for coolant
Typical causes..such a situation:
- thermostatic operation of the equipment for heating circuits or indirect heating boiler, temporarily deactivates the coolant.
- a temporary blackout of one or more circuits due to the lack of demand for heating of various premises.
- temporary decommissioning circuits for repair or maintenance.
- start the boiler equipment to warm up, with a gradual step-workers connecting circuits.
anything critical happens - the boiler circuit operates in most of the "on" pumping the bulk of the coolant in a small circle.In most
gidrostrelke formed a vertical downward flow of feed to the "return pipe".
Temperature: t1 = t3, t2 & gt;t4 .
In this mode, the temperature in the "return pipe" quickly comes to the threshold of automatic shutdown of the boiler equipment, thus achieving efficient use of fuel.

hydraulic separator can perform a number of useful features.

  • First of all - the promise remark about the heating system is not very branched type.Gidrostrelka can be a useful, and sometimes - and an indispensable element in the case of the boiler heat exchanger made of cast iron.
Cast iron heat exchangers do not like sudden changes in temperature - can give a crack

cast iron heat exchangers do not like sudden changes in temperature - can give a crack

For all its merits, this metal still has a significant drawback - mechanical and thermal brittleness.A sharp temperature drop with a large amplitude can lead to cracks in the cast-iron parts.Thus, the ignition of the heating system during the cold season may be a very substantial difference in temperature - in the furnace and in the return pipe.Soak in the large coolant circuit takes a lot of time, and this period is very critical for the cast iron heat exchanger.But if the circuit is "shortened", that is run through the hydraulic separator, coolant heating realized much faster, and the likelihood of the boiler heat exchanger deformation will be minimal.

By the way, some manufacturers of boilers with cast iron heat exchangers directly indicate the need to install gidrostrelki - violation of these requirements entail the termination of the warranty.

  • sharp expansion of the tube in gidrostrelki and the consequent drop in the fluid velocity may well be additional "put at the service."
Possible additional functions gidrostrelki - air separation and purification of coolant from the suspended solids

Possible additional functions gidrostrelki - separation of the air and cleaning of coolant from the suspended solids

  1. completely eliminate flatulence in the coolant - is almost impossible, so the heating system installed drain bleed screw or automatic air vent - Security group for heating radiatorsetc.Very effective due to the large volume of air can become separator and a hydraulic separator.To do this, on top of him crashing into the automatic air vent (Pos. 1).In addition, factory production models are often installed inside the cylinder a special fine-meshed net, which promotes the active separation of dissolved air from the liquid and then release it through a steam trap.
  2. sharp slowdown in the flow rate contributes to the gravitational settling of suspended solids, the appearance of which is likely in the coolant.If the bottom of set-off valve (pos. 2), it will be possible to regularly clean the system of accumulated sludge.

Video: Animated demonstration of the operation of the hydraulic separator

specifics of design of the hydraulic separator

As can be seen from the above, the hydraulic separator design - is fairly straightforward.Nevertheless, it must comply with certain rules.

sale in specialized stores you can find a lot of proposals, in different sizes and configurations, that is, it is possible to choose the model most suitable to its parameters under existing or planned heating system.Often there are original models, which combine constructively and very low loss header and manifold for connecting circuits.Sometimes you can see gidrostrelki and generally unusual star-shaped configuration.

Various choices of hydraulic separators prefabricated

Various variants of hydraulic separators prefabricated

However, if you look at the cost of these products, you probably arises thought about the possibility of self-production.Indeed, for the owner of the house who is familiar with the locksmith and welding work to mount a hydraulic separator - should not be difficult.