Efficient heating homes - one of the most important tasks for every homeowner. An interesting solution to this problem can be a steam heating system, the operating principles, and that the device is different from the usual water schemes.
It's not the easiest option, has its own strengths and weaknesses. We will tell you about the rules of the device and organization features of the system with a vapor coolant. You will learn how to make a local heating in a private house, and how it competently operate.
The content of the article:
- The principle of action of the steam system
- Features Low pressure systems
- Assessment of the advantages and disadvantages
- steam heating system design
- Installation based on wood-burning stove
- A few tips
- Conclusions and useful videos on the topic
The principle of action of the steam system
When the water boils at a constant pressure, it retains its temperature constant. The resulting vapor of the boiling point has a significant amount of thermal energy. At the time of condensation, i.e. the conversion of steam into the liquid, this energy is released and transferred to the environment.
This principle is used in steam heating systems. The water boils in the boiler, the steam moves through the pipes to the radiators there is condensed and parts with heat, thereby heating the indoor air.
Obtained during the condensation water continues to move through the pipes and returns to the special drive and then supplied to the heater is naturally or forcibly by a pump.
Schemes of organization and equipment to the principles of steam and water heating are similar. They include similar components
The difference is that the steam enters the heating apparatus, which during the condensation gives heat of evaporation and hundreds of times decreases in volume
By type of move coolant and steam systems also fall into the gravitational and forced equal to the water rules are shown in the assembly and organization
The special features of the construction of steam systems include increased heat resistance, which are required to have heating appliances. After the temperature of the incoming vapor in them can reach + 130º
Within the different systems themselves steam piping. Steam supplied through the steam line which have to be broader in cross section and resistance to-heat than condensate transmitting in boiler condensate
According to one embodiment of the condensate return receipts for heating the steam in the boiler circuits are divided into open and closed. The first condensate accumulated in the first tank, then transported to the boiler pump. In closed condensate moves directly to the boiler
In order to balance the power on time and heat in the steam systems are often used in place of standard batteries registers finning
Steam heating circuits are only closed type, because the evaporation of the coolant outside the system should be avoided. The volume of condensate to be accurately count to couple with cooling devices were not formed in the air bags, preventing movement of the pair
Analogies in the steam and water heating
The specificity of action of steam as a heat transfer medium
Types of steam heating systems
Steam and condensate pipes
Open the steam system
Registers heating finned
The accuracy of calculations in the organization
Depending on the steam pressure inside the heating system are divided into:
- vacuum steam;
- low pressure;
- high pressure.
The first pressure is less than 0.1 MPa, in the second - is even lower - 0.07 MPa, and thirdly - more than 0.07 MPa. Upcoming low pressure systems have access to the air from the atmosphere, but they may be closed, i.e. fully sealed.
In this diagram, the principles demonstrated by steam heating wiring. The heating device should be positioned lower than the radiators, condensate gives slope
In such systems typically used a so-called dry saturated steam, which contains no suspended water particles. The amount of steam in the system is reflected in her work. If a couple is too small, it will create problems for the free flow of condensate, and at the bottom of the heater will meet the cold air.
A sufficient amount of steam condensate outflow improves the process that is pushed to the walls and flows thereon a thin film of water.
In closed systems the water immediately after the condensation is supplied to the heat exchanger, but is often used Open-loop system in which coolant is first going to storage and then pumped into the boiler for heating.
Condensation may completely fill the tube, which moves the heating or only partly. The latter option is preferable, since when disconnected pipe system therein remain dry.
If steam heating the coolant after condensation is moved directly to the boiler for further heating, it called a closed system. If condensate is first collected in a storage tank from which the pump is pumped into the boiler, the system belongs to the category of open
Features Low pressure systems
A common version of such a system - closed, with gravity condensate return in the boiler, which fills the tube is not fully applied while the upper distributing pipes.
First, the system is filled with water to the desired level, then starts heating. The condensate flows down the common riser and upon reaching a predetermined level in the boiler is forced out.
In the same system with the lower wiring it is recommended to install pipes with a slight slope in the direction of movement of the pair to reduce noise effects. In place of the condensate water trap satisfied folded preventing movement of vapor in the condensation backbone.
steam velocity in such systems should be moderate, not more than 0.14 m / s. Otherwise, the steam will capture particles and moisture accumulated on the walls. As a result, the system operates with a great noise, and increased risk of water hammer.
Combined wiring, ie, combination of the upper and lower wiring is used, if the tube paved under the upper or middle storey house floor. The lumen tubes through which water returns to the boiler, in which case the condensate will be closed.
If the system pressure exceeds 0.02 MPa, it should be made open. Air is removed through an accumulator for the condensate, and that the system does not leave the steam or the water seal trap pose. Water is pumped from a reservoir to a heat exchanger, which allows to set the drive below the level at which the heat exchanger.
The heating medium for heating private houses boiler is heated in a heat exchanger located in the boiler room. Upon reaching the working temperature of the steam is moved to the collector, separating the flow into two circuits: for the main boiler rooms and for (+)
Assessment of the advantages and disadvantages
What good steam heating system? It is relatively easy to do, even on the basis of a conventional wood-burning oven. This is especially true in areas where central gas supply is not available, and wood or other solid fuels are readily available.
The steam as a coolant is far ahead of the water. The rate of warming of premises it is three times higher. In addition, the steam heating system can hardly be damaged during the cold winter due to lack of heating.
If the furnace burnt, the water from the system will gather in the storage or in the heat exchanger and the pipes and radiators remain empty. When water heating freezing coolant, which fills the entire circuit, as is known, leads to rupture of the tubes.
Finally, steam radiator dimensions must be significantly less than that for water-based systems, since the amount of the resulting heat energy increases several times. It's a bit reduce the cost of installation of the heating system of the house.
Grilles for steam radiators - is not only element of interior design, but also a means of protection against burns
The list of advantages of the steam system is complete, and you can continue with its shortcomings, which are quite significant:
- High risk of burns;
- increased noise level during operation;
- difficulties in adjusting the operation of the system;
- the need for costly piping, etc.
Safety standards central heating is not recommended for premises, because it represents a high risk to the health and lives of people living in the house.
Thus, the operating temperature of radiators is very high, it is possible to receive serious burns if touched. Therefore, all the radiators will have to close the Trusted decorative grilles.
Conventional PVC pipes are not suitable for such a system since they must withstand high pressures and temperatures over 100 degrees. The same requirements apply to the remaining elements of the system. steam heating pipe should be made of copper or galvanized steel.
Copper pipes - the ideal, but it is not the cheapest option Communications for steam heating systems. To connect these pipes need welder
In any case, this point in the budget can not be called. Security should be paid close attention. All installation work, such as welding of copper tubes, require extremely high-quality performance. If the connection will break through and the hole will break the jet of steam, some of the tenants risk of serious burns.
Stainless steel tubes capable of withstanding such load characteristics for steam heating systems, such as high temperature and high pressure in the system
Another drawback of steam heating - increased noise level. Should perform installation of the radiator properly to resolve this issue. They are hung on special noise canceling brackets. Boiler or furnace is best to put in a separate room. Furthermore, copper pipes can be placed in the thickness of walls, which will also reduce the noise level.
Finally, adjust the heating temperature in the room with the central heating a little difficult. You can not set the thermostat and simply reduce the amount of steam. Will have to reduce the amount of fuel that is not always easy, or ventilate the premises. Before starting work on the installation of steam heating system should take into account all these factors.
steam heating system design
Even for a small room it is best to make the project. The system, made to "maybe" with high probability will soon require rework, and compiled on paper scheme will immediately identify weaknesses and correct them.
For example, to create a system with a natural circulation of coolant, a heat exchanger, and accordingly, a heating device must be positioned at the lowest point of the house.
Steam and condensate pipes of heating systems with natural type coolant flow satisfied sloping towards its movement (+)
This means that the furnace or boiler must be below all radiators, and pipes which are not vertically and horizontally or at an angle to the vertical.
If you place a heater in such a way does not work (in the house there is no basement, basement used for other purposes, etc.) should be preferred heating with forced circulation.
The diagram shows a heating system with forced circulation. For its installation will need a circulating pump and storage tank
Therefore, steam heating circuit must include a pump which is pumping water to the heat exchanger. An important point in the design of the heating system - how to connect radiators. Serial connection or a so-called single-tube system requires connection of all radiators in order.
As a result, the coolant will move sequentially through the system gradually cools. This is an economical way to connect, which is easier to install, and the cost will be cheaper.
But the warm-uniformity in this method suffers because the first radiator is the hottest, and the last coolant goes on is half the cooled down state.
Monotube connection radiators, as can be seen from this scheme involves a serial installation. On the last radiator coolant flows already cooled down
Monotube solution may be acceptable only when steam heating is connected in the country or in a small house on an area less than 80 square meters. m. For the cottage or spacious two-story structure is more appropriate two-pipe system, in which the radiators are connected in parallel.
Scheme One tube provides simultaneous rather than sequential delivery of coolant to each radiator, and heating is carried out more uniformly Improvement. But with two-pipe loop to each radiator bring two pipes have: direct and "return flow".
Such a system is more difficult to implement, and it will cost a bit more expensive than installing a single pipe system. However, the vast majority of hot water heating systems carried out by two pipe system, despite the difficulties, and functions quite well.
This diagram shows a double-pipe heating system mounted steam radiators. Each radiator is connected to a common riser and a return pipe, which provides uniform distribution of coolant
If the heat source is assumed to use a wood burning stove, it is necessary to immediately calculate and design a special heat exchanger. It looks like a coil, welded from metal pipes. This element is integrated directly in the furnace structure, and not set separately.
Therefore, a new furnace design should also consider the design phase. You can also use an existing furnace, but it will have to be partially disassembled to mount a heat exchanger inside.
For 9 kW heat exchanger needs a surface area of about one square meter. The larger the heated area, the greater should be the size of the heat exchanger.
If you heat the room it is assumed by a boiler, it's all a bit easier: it is necessary to buy and install. Usually, steam heating in the house is recommended to take a water-tube boiler model, as the most effective.
Although the fire-tube, flue or flue-combined fire-tube models can also be a very viable option.
Sometimes organizations use steam heating homemade potIn which burned waste machine oil. However, this option is considered suitable for use in the back rooms, for example, in the garage. For apartment building that option is not too good.
Installation based on wood-burning stove
If the project is compiled, it is time to stock up on the necessary materials and tools. Calculate the required number of elements of the system will allow the project drawn up earlier.
It should be noted all the turns, compounds tees installation site radiators, etc. Besides, it is necessary to purchase collars for pipes and brackets, which are mounted radiators.
The boiler steam heating system, arranged on the base wood oven, is mounted directly therein. To connect the boiler steam and condensate pipes
Tube length as calculated according to the scheme. If necessary, to reduce the vapor pressure in the system, it will take the pressure reducing valve. Hydraulic valve is needed to allow complete draining of system for cleaning, maintenance or repair.
Before each radiator is recommended to install shut-off valve, which will turn it off for repair, replacement or washing. Also on the radiators installed I bleed screwTo pull the caught in the air system. Although steam is gaseous and not liquid substance, the presence of air in the system can adversely affect its efficiency.
To the condensation process takes place in the radiators, but not in the storage or in the riser, it is recommended to set the output tee with a stopper, through which will pass only water. If the planned installation of systems with circulation pump, the circulation pump will need. In addition, we need the capacity to collect condensed water.
Gravity system in such devices do not need. But pipe through which water is guided to the heat exchanger, it should be wide enough to ensure rapid movement of liquids for further heating.
The absence in the steam heating system relief valve, which device is represented in the diagram, can cause serious damage due to excess pressure
Besides the usual installation tool required need welder compounds of copper pipes. galvanized steel construction are typically threaded connections, which must be carefully sealed. If you plan the installation of steam heating of the oven, it will have to start from the manufacturing of the heat exchanger.
steam heat exchanger embedded in the wood-burning furnace, the system consists of a hollow metal pipe through which water circulates. The element may be of any shape corresponding to the dimensions and shape of the furnace
Brewed from the metal pipes of 2.5-3 mm thick or slightly thicker. The heat exchanger can be made in the form of a coil, or in any other form. The main thing is that the device fits within the wood-burning stoveAs well as to the surface it was large enough to heat water and generate steam.
The quality of welding heat exchanger has to be perfect, without exaggeration. Even microscopic cavities in the seams are unacceptable, because the device will be subjected to increased pressure from the hot vapor. After the heat exchanger is ready for installation, it is necessary to check each weld.
To do this, first all seams plaster white chalk. Then one of the openings of the heat exchanger is closed and the second poured kerosene as long as the device is filled to the top. Now we need to wait a bit, and then evaluate the condition of the joints. If there are cracks through which seeps kerosene, and in places the chalk darkens.
Identified flaws correct, then check is performed again to verify integrity of a device. Now it is necessary to wash, and then start laying a wood stove. The heat exchanger is securely inserted into the furnace, and to its input and output pipes are attached, which are then used to connect the heat exchanger to the heating system of the house.
Masonry furnace is completed in the normal manner for such structures. Then, a pipe laying and radiators of the heating system in accordance with the draft drawn up earlier. First set radiators, using brackets, which will extinguish the noise from the operation of steam heating.
On each radiator bleed screw set to be able to release the air. Stopcocks need one more than the radiator, because you need to establish a common shut-off valve at the beginning of the system. Before that, the crane also put pressure reducing valve and pressure-reducing cooling unit.
In the end, if it is provided by the project, set to drive the coolant and circulation pump. For systems arranged with natural rather than forced circulation tank and pump are not needed. But the pipe which leads to the heat exchanger, it is necessary to give a small inclination of about 3 mm per meter.
Modern boilers for steam heating in the house - it's reliable devices that operate on different fuels and equipped with automatic control systems
System with a boiler mounted about the same: according to the project and adjusted for the particular equipment. For example, a pressure reducing valve and a cooler, more likely, will not be necessary, because of the pressure control system and the temperature of steam is already built into the boiler.
A few tips
When mounting the steam heating system to be remembered that all of its elements must withstand the high temperature, over 100 degrees. For example, a conventional membrane expander as a reserve capacity in case of increase in the volume of coolant is not suitable because its maximum - it is 85 degrees.
Chimney furnaces in which integrated heat exchanger will become dirty quickly than a conventional oven. therefore chimney cleaning you need to plan and carry out more often.
Oven with a heat exchanger can be used if desired, as for cooking, but it is not too convenient. In the summer, when heating is not necessary, the oven can not kindle. We'll have to look for an alternative. Simply, if the kitchen in the house is arranged separate convenient oven.
For information on how to design and build a system of steam heating own hands, detail in this articleRecommended us to read.
Conclusions and useful videos on the topic
Practical experience of remaking a wood-burning oven in the steam boiler heating system is shown in this video:
Continued steam heating installation process can be found in this file:
About the difference between forced and natural circulation in heating systems explained in detail here:
Steam heating - is not the easiest option to implement an autonomous heating system. But with the right design and installation with steam can be effectively and relatively inexpensively provide the house the necessary amount of heat.
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