Individual water supply systems often operate at unstable temperatures and pressures. Sharp and strong fluctuations as a result can cause breakdowns on individual circuits and pipeline nodes. A hydraulic gun helps to eliminate such situations. It not only softens the work of the engineering network, but also performs additional functions, including filtering. What is a hydraulic arrow in a heating system? This is a small plumbing fixture that is built into the network during the initial installation phase or as part of the next maintenance activities.
Device assignment
To understand the essence of the tasks that a hydraulic arrow (hydraulic separator) solves, one should understand the nuances of the operation of independent heating systems. That is, communications operatingon its own source of heating the water coolant. In home systems, boilers, boilers, water heaters, etc. can form the basis of the heating infrastructure. So, why do we need a hydraulic arrow in this type of heating system? The need to use a temperature and pressure stabilizer arises from the uneven distribution of the load over all circuits of the system. The unevenness is due to the complexity of the pipeline, burdened and consuming equipment. At a minimum, any water heating complex contains shut-off valves, as well as the simplest means of monitoring and regulating flows. To these devices are added target devices for the emission of thermal energy - radiators, convectors, standard batteries, etc. But that's not all. To ensure the circulation of the coolant, pumping groups and collectors are introduced into the network. Circulation pumps, coupled with boiler equipment in an overloaded infrastructure, cannot always provide uniform support for pressure and temperature. Hence the need for additional regulators and stabilizers.
There is an opinion that the hydraulic arrow is required only to prevent thermal overload in systems where pumps of different capacities are used. They operate from the same heating source and, due to the difference in characteristics, are not able to equally maintain pressure balances. The basic purpose of a hydraulic arrow in a heating system really comes down to leveling their work, but in practice other positive effects are also achieved. These include:
- Cleaning contours.
- Optimize system performance.
- Prevention of risks of backflow of coolant.
The design of the water gun
The hydraulic separator looks like an optimized manifold with inlet and outlet channels of different diameters. Its fundamental difference can be called the presence of advanced means of monitoring and measuring the parameters of the coolant. What is a hydraulic arrow in a heating system in terms of a functional device? This is a construction that includes the following nodes:
- Outlet ball valve.
- Manual air vent.
- Plug for magnetic pickup sensor.
- Sleeve for temperature sensor installation.
The design also includes removable insulation, branch pipes for connecting circuits, valves and, in some modifications, a small reservoir like a hydraulic tank. The function of the latter is usually transferred to the thickened part of the separator pipe, which may look like a vessel. As for the materials of manufacture, stainless metal alloys are usually used for the body of the hydraulic gun. Polypropylene devices are also used, but due to high temperature loads, their use is limited.
The principle of operation of the hydraulic arrow in the heating system
The main task of the hydraulic separator is to separate the boiler circuit from the working branches of the heat carrier distribution. The device provides pressure equalization betweencollector groups that ensure the movement of flows in the supply and return. Otherwise, conditions are created for mixing the flows of cold and hot water, which reduces the heat output in the circuits. How is the regulation process implemented? The principle of operation of a hydraulic arrow in a heating system is to create a buffer zone with zero resistance in intermediate areas where pressure drops are possible. This ensures pressure relief on all circuits between the pumps.
The need for a natural connection of the hydraulic arrow function occurs in the following situations:
- The flow of hot water from the boiler is weaker in strength than the flow of the coolant on the heating circuits.
- The flow of cold water from the heating circuit is weaker than the flow from the boiler.
In normal operation, if the equipment is chosen correctly, the delimiter buffer is used to a minimum extent. How does a hydraulic arrow work in a heating system if there is a violation of the balance of movement of the coolant? Volumes that exceed the norm in terms of balance from the supply or return side go to the hydraulic tank or the thickened part of the hydraulic arrow pipe. Theoretically, situations are also possible when water from one of the circuits enters the opposite line of movement, bypassing the buffer zone. This indicates an excessive discrepancy between the capacities of the boiler and pumps, which requires the replacement of units.
The nuances of the hydraulic arrow in systems with a pumping group
In order to improve work efficiencyheating circuit infrastructure can be supplemented with auxiliary pumps and collectors. However, along with the increase in productivity with this approach, one can also expect an increase in the load on individual circuits. As a result, a heating system with a hydraulic arrow and a pumping group can function with the following problems:
- If circulation units with different power ratings are used, then weak pumps will not be able to cope with the loads present on neighboring circuits.
- In itself, the division into many circuits as a result of the installation of additional functional units also affects the operation of the pumping group, which can lead to its overload and failure.
- If the project provides for a standard difference in pressure indicators on individual branches, then the slightest violation in balancing will cause an accident already in the pipeline.
- During the normal shutdown of individual pumps to cut off the water supply to their target area, the risk of movement of "stray" currents provoked by neighboring circulation equipment will increase.
The above operational problems usually arise in complex industrial systems in factories where dozens of consumers are served by one heat source. In heating systems of a private house, a hydraulic arrow usually works in conjunction with a small pumping group and two or three collectors. Even if we are talking about a two-story house, two pumps may be enough for the full circulation of the coolant. The main thing is to choose them correctly in accordance withspecific system needs.
Calculation of the water gun
The performance of a hydraulic separator is determined by the following set of specifications:
- Operating Temperature - 95 to 110°C.
- The serviceable power of the boiler is about 100-125 kW.
- Productivity - average consumption from 4 to 8-9 m3/hour.
- Center distance relative to consumers is about 200 mm.
Based on these parameters, the device model is selected for a specific system. How to calculate the hydraulic arrow of the heating system? In addition to structural compliance (dimensions and dimensions of nozzles), for a correct assessment of the throughput from the point of view of the possibility of balancing the system, the diameter of the buffer zone must be calculated. Experts recommend that the optimal section of the separator tank be taken as a size capable of providing a flow velocity of 0.2 m / s. But this parameter will be directly related to the amount of water consumption in 1 hour. That is, it is necessary to initially determine the throughput of the target circuit or group of circuits. This is the standard value of the boiler, which can be expressed as follows:
- Main heating zone - about 2 m3/hour.
- Secondary heating zone - about 1.5 m3/hour.
- Water heating zone of the boiler - 2.5 m3/hour.
- Low temperature section for technical needs - 1 m3/hr.
The result istotal consumption is about 7 m3/hour. Under this value, a pumping group, collectors and a hydraulic arrow are selected. With this capacity, the separator tube vessel diameter can be approximately 110-120 mm depending on the design of the specific model.
Installation of the hydraulic gun
For self-installation, it is advisable to purchase ready-made separators in the assembly. In a complete set, the device includes the necessary shut-off valves, an insulating shell, a degasser and a sludge separator. If necessary, you can additionally purchase fittings and plumbing adapters for connection, but to ensure reliability, it is better to refuse adapters.
After shutting off the water and turning off the equipment, you can proceed to install the hydraulic arrow in the heating system in a horizontal or vertical pattern. The installation process can only be carried out in rooms with a positive temperature. First of all, the device is fixed at the place of operation to the wall with brackets. The position of the separator is thought out in advance, at which it will be possible to connect pipes to its branch pipes without additional manipulations. It is very important to keep the connections correct. The inlet supply circuit on one side of the water gun must mate with the pipe from the boiler. A branch to consumers (heating circuit) is connected along the same line from the opposite side. The return line is connected in the same way.
In the process of installing a hydraulic arrow in the heating systemwith your own hands, it is especially necessary to remember safety measures. Even with the circulation system turned off, a splash of hot water is not ruled out, so it is advisable to work with heat-insulating gloves. After installation of the equipment, a pressure test is performed, the purpose of which is to check the system for tightness. Then the first start-up is carried out using a coolant diluted with a propylene mixture with a 40% glycol content.
What is a hydraulic arrow in a heating system with a condenser?
In systems that ensure the operation of underfloor heating and radiators, the principle of collecting condensation heat has recently been used. Special boilers operate on it, provided with a tube for accumulating the energy of the released steam. Whereas in conventional systems the steam is simply vented into the chimney, in equipment with a condenser it collects on the surfaces of the heat exchanger and is used in the overall heating process. What is a hydraulic arrow in a heating system with this principle of operation? To begin with, it is worth emphasizing that for all condensing boilers above 45 kW, the use of pressure and temperature stabilizers is mandatory, since additional energy can affect the performance of the equipment in different ways.
Further, in the process of choosing a model of hydraulic arrows and pumps, two points should be taken into account. Firstly, the total flow in the main heating circuit must necessarily exceed that of the boiler line. Secondly, the presence of a default separator will increase the temperature load on the return circuit entering the boiler. This will reduce performance and will also require an appropriate adjustment for pump power. In general, with negative factors reducing efficiency, it is the hydraulic arrow that will balance the operation of condensing boilers that form a cascade system. For example, if two units are used, then the hydraulic arrow will shift the excess pressure from one to the other.
Additional functionality of the water gun
Today, hydraulic separators with only one balancer function are less and less common. Extended configuration allows it to be used also for comprehensive monitoring of performance indicators in the system. If the built-in sensors are connected to the boiler automation, the device will provide more accurate control of the boiler modes and increase the reliability of the fuses. Why do we need a hydraulic arrow in the heating system, in addition to controlling equipment? The presence of a thermostatic valve will additionally provide a gradient on the secondary distribution lines of the coolant, and an air vent will create conditions for the release of dissolved oxygen in hot water flows. But it is important to determine in advance which air exhaust system will be optimal in a particular case - automatic or manual.
Another common function of a hydraulic arrow in a heating system is to remove sludge. For its implementation, a sludge separator is used. Large suspensions and deposits remain in a special storage tank, and during maintenance are released through the valve. More modern models are optionally supplied with magnetictraps that allow the removal of magnetite.
Do I always need to use a water gun?
It has already been noted that in some cases the use of this device is mandatory. But this applies only to systems in which non-standard heat exchangers are present or we are talking about complex branched circuits with multi-tasking manifolds and pumping groups. But why do we need a hydraulic arrow in a domestic heating system, in which there is only a boiler, a boiler and a circulation pump? The risks of creating thermal and hydrodynamic imbalances in such configurations are minimal, and the negative factor of smoothing operating parameters is more likely to reduce the performance of the equipment. But even in such cases, the hydraulic arrow can justify itself as a means of increasing the reliability of the units and the pipeline as a whole. Even a minimal reduction in pressure drops in the circuits will increase the life of the equipment - accordingly, its service life will be extended. In other words, the question of using a water gun for domestic needs can be presented as a choice between economic feasibility and energy efficiency of the heating system.
Conclusion
Hydraulic systems for water supply and heating, as technological complexity increases, require the connection of more and more new devices and structural additions. This is usually associated with various control and management tools that make the network more ergonomic and functional. In this case, it could besecurity and improve the reliability of system components. At the same time, the integration of the hydraulic separator itself does not cause much trouble. Do-it-yourself standard installation of a hydraulic arrow in a heating system is carried out in 30-40 minutes, without requiring the connection of a special tool. In addition, on the basis of the device in a complete set, you can additionally get an air vent and cleaning tools, which in any case will eliminate the need for their third-party installation. In the future, the user will be required to periodically check the integrity of the structure, its tightness and correct operation as part of a general revision of the heating system.
