Household induction boiler. Methods for organizing induction heating of a private house with your own hands

Induction electric boilers heating systems are superior in many characteristics to the still more common boilers with. Electromagnetic induction was discovered by the English scientist Michael Faraday. The principle of its operation began to be used in the production of generators and electric motors, transformers.

But only after some time did human thought reach the point that this principle can also be applied to. It was only in the nineties of the 20th century that the first induction electric boilers for home heating began to be produced.

Boiler design

Boilers of this type have a very complex structure. The design is a multi-layer mechanism.

The first layer in it is outer casing which is made of metal.
The second layer is insulation, made in two layers (thermal insulation and electrical insulation).
The third element of such a boiler is core. It consists of two walls. Is a ferrimagnetic steel pipes(two pieces) with a wall thickness of 10 mm. These pipes have different diameters and are inserted into each other. Inner pipe surrounded by a winding, this pipe serves as the core, and the outer pipe is the heating element.

Principle of operation

The coolant in induction electric heating boilers is most often water. It enters a pipe that is welded to the bottom of the boiler. Water passes through the gaps between the outer pipe and the walls of the boiler body. During this time, it heats up to the required temperature, after which it enters the core (its inner diameter). The water then rises up the pipe to the outdoor heating units.

Why choose an induction boiler for heating your home?

The coolant undergoes double heating;
Scale does not form on the pipe walls, because magnetic induction creates vibration on high frequencies. The boiler will last a very long time;
Minimum heating time even in comparison with heating elements. This is due to a lower degree of inertia;

How to choose an induction boiler

There are two types of induction boilers:

single-phase,
three-phase.

Many devices have a special control panel. It allows you to set room heat parameters.

When choosing a boiler of a certain power, it must be calculated as follows: by one square meter area will need 60 watts. If residents do not live permanently in the house where the boiler is planned to be installed, then this figure can be reduced.

For a house with an area of 120 square meters, an induction boiler with a power of 60 kW is sufficient.

Advantages of induction heating boilers

Boilers do not require a special room for installation and installation of the chimney

Works on both AC and mains power direct current. Low voltage levels are allowed;
Heating elements, which often fail and require replacement, are absent in this type of boiler;
The likelihood of leaks is minimized due to the overall design of the boiler. It is welded hermetically and reliably;
Boilers of this type are completely free of scale;
High category fire safety, as well as electrical safety. There is no need to install the boiler in a special room, it does not require the installation of a chimney;
Efficiency is 100% and this figure does not decrease over the years;
The manufacturer's warranty on the core is a quarter of a century;
The coolant can be not only water, but also oils and antifreeze. The requirements for coolant quality are quite mild. The coolant should be changed no more than once every ten years;
Simple self-installation boiler;

Disadvantages of induction heating boilers

High weight, a cauldron with a diameter of 12 cm and a height of 45 cm will weigh 23 kilograms;
High price. This is one of the most expensive types of boilers for heating homes;
Only suitable for closed systems heating;
At a distance of several meters, this boiler can create wave interference. It is not recommended to place it near household appliances;

Economical use

Compared to heating element boilers induction boilers are much more expensive. But, you need to understand that the colder it is outside, the faster the new induction heating ate to pay off. Heating element boilers, of the same quality and with similar performance properties, fail faster. This is due to the fact that scale will form on the heating elements.

Half a millimeter of scale reduces heat transfer by 10%. The larger the scale layer, the worse the heat transfer of the boiler will be.

Induction boilers can save up to 30% energy

If we compare the power of heating element and induction boilers depending on the operating time, then the first category will lose 40% of its power over four years of use. Induction boilers are energy-saving equipment; they can reduce operating costs by 30% or even more.

Induction boilers – perfect solution for heating residential buildings. Despite the initial high cost, these devices practically cannot fail. Because they do not have a heating element. And the absence detachable connections will completely eliminate system leakage.

The design of this group of equipment is simple and differs little from analogues with heating elements. The main difference is in the form of heating elements. In such boilers, instead of the usual spiral, a block of electrodes is installed in the “flask”, placed in a heat-insulated housing (water boiler tank).

The operating principle is based on conversion kinetic energy salt ions dissolved in liquid into heat; The faster they move, the higher the degree of heating. It depends not only on the constant change of poles (~U 50 Hz), but also on the regulation of the process by the voltage supplied to the boiler electrodes; By changing its value, the user selects an acceptable coolant temperature at the outlet of the heating installation. Fundamental difference from the operation of a heating element boiler is that water is part electrical diagram; current passes through it.

What does this mean? The electrical resistance of a fluid is directly related to temperature. By raising it, it is possible to achieve a more rational consumption of electricity (75 0C - optimal mode). And the specificity of the process taking place in the boiler tank eliminates heat loss.

Advantages of electrode models

Large assortment. Select by connection method (1 or 3 phases) and power (in the range of 2–50 kW).
Project for installing an electrode boiler, unlike gas equipment, not required.
High efficiency – up to 98%.
Compactness.
Inertness to industrial/voltage changes. Its instability does not affect the operation of the installation.
The inertia of the electrode boiler is zero. All thermal energy is spent on increasing the water temperature, and not preheating the heating element.
Versatility of use. In heating schemes with electrode boilers, water or “anti-freeze” can be used.
Reliability. The whole device – tank + metal pins; there is nothing to break.
Ease of installation. An electrode, like any other electric boiler, is not needed; There are practically no restrictions on the installation location.
Possibility of automation. Although expensive models are initially equipped with everything necessary.
Electrode boilers are capable of operating in cascade circuits. And this is an increase in power + redundancy.
It is not necessary to call a specialist for maintenance or replacement of electrodes.
Affordable prices for equipment.

Minuses

Requirements for the mode. When the coolant temperature exceeds 75 0C, energy consumption increases. For heating systems with a large extent, it is difficult to choose a boiler of appropriate power. Reasons: limited supply of energy resources for the private sector, increased load on the line.
Sensitivity to fluid quality. As on the heating element, salt formations are gradually deposited on the electrodes; Regular cleaning is required.
Steady decrease in power. Associated with the natural “thinning” of the electrodes. They need to be changed regularly, like heating elements in traditional models.
Reliable grounding. It’s difficult to organize in an apartment, but it’s required condition installation of equipment. The current in the tank passes through the coolant, and when operating an ungrounded electrode boiler, the user runs the risk of feeling a shock even when lightly touching the heating radiator.
One of the conditions for economical operation is high-quality automation. And it is expensive.

As a disadvantage, a number of sources indicate that electrode boilers connect only to the network AC voltage; at U= ionization of the coolant occurs. Every good owner has a backup unit (diesel or gasoline), which means this minus is irrelevant.

Note. To increase the efficiency of an electrode boiler, you need to properly prepare the coolant, achieving optimal resistivity current Substances available in every home (for example, baking soda) and distilled water are used. But not all drugs are suitable for this; some initiate metal corrosion. It is also necessary to correctly determine the concentration of the “solution”, otherwise the power of the heating installation will sharply decrease. It is better not to practice without consulting a professional!

Induction heating boilers create significant competition for gas and heating elements. They are positioned on the market as one of the most economical. They began to be used back in the eighties for industrial purposes. Household models were first introduced in the mid-90s, and over more than thirty years of history they have undergone many changes.

First meeting

Induction boiler in operation

The name itself suggests that the boiler’s operation is based on the principle electromagnetic induction. To understand the essence of the process, it is enough to pass a large current through a coil of thick wire. A strong electromagnetic field will certainly arise around the device. And if you place any ferromagnet (a metal that is attracted) into it, it will heat up quite quickly.

The simplest example of an induction heat source is a coil wound on a dielectric pipe. You just need to place the steel core inside. The coil connected to a source of electricity will heat metal rod. Now all that remains is to connect the device to the main line through which the coolant circulates, and the primitive induction boiler will begin to generate heat.

The whole operating principle can be described in a few sentences. Electrical energy generates an electromagnetic field. Under the influence electromagnetic waves The metal core heats up. Excess heat from the rod is transferred to the coolant (ethylene glycol, oil or water).

Intense heating of the liquid generates convection currents. The hot coolant tends upward, and its force is sufficient to operate a small circuit. In long-distance lines it is necessary to install a circulation pump.

Truth and myths

In specialized stores you can often hear amazing characteristics that are attributed to this heating equipment. Unfortunately, not all of them are true. In order to increase sales, department managers sometimes lie. It's time to consider the main theses with which they operate.

Novelty

Claim: Advanced innovation based on physical principles.

Michael Faraday discovered the phenomenon of electromagnetic induction in 1831.
In industry since the second half of the twentieth century induction furnaces successfully used to melt steel.

No innovations, much less innovative technologies, have been implemented since then. This is a well-known principle that has found a new application and has helped manufacturers fill a hitherto empty niche.

Economical

Vortex induction heaters

Claim: Induction boilers use 20-30% less energy than other electric counterparts.

Any heating device converts 100% of the energy used into heat - provided that it does not perform mechanical work. Coefficient useful action maybe less. It all depends on the heat dissipation around the heating device.
The time it takes to reach the required coolant temperature directly depends on the efficiency of the heating element. Any statements that induction models consume less electricity are nothing more than gimmicks. The law of conservation of energy is unshakable. To obtain one kilowatt of heat, it is necessary to spend at least 1 kW of electricity.
Some of the heat will inevitably be wasted. For example, the coil itself heats up, since the resistance of the conductor is not zero. However, the losses in any case remain in the house, and do not fly away through the chimney ducts.

The conclusions are quite obvious - the manager who makes such statements is engaged in outright deception, or is himself misled.

Durability

Statement: the equipment works flawlessly for at least a quarter of a century. Its reliability is not comparable to other electrical analogues.

Mechanical wear of boilers of this type impossible in principle, since they have no moving parts.
Copper winding has a decent margin of safety. Provided it is properly cooled, it can last indefinitely. Insulation breakdowns are also not a problem for her. The fact is that the turns are not wound end-to-end, but at small intervals.
The core will gradually deteriorate in any case. It can be affected by aggressive impurities, and the constant heating-cooling cycle does not impart strength. However, this process is so extended in time that more than a dozen years may pass before its completion.
The control circuit includes several transistors. It is they who determine the failure-free operation period of all equipment. Component manufacturers, as a rule, declare a ten-year warranty. However, there are often cases when they worked out 30 and more years- it all depends on the technological process.

Thus, induction boilers will in any case work much longer than their heating element counterparts. The heating elements of the latter may require replacement after just a few years.

Indispensability of characteristics

New generation induction boilers

Approval: appliances with traditional heating elements lose power through scale formation. This process is absent here, and technical specifications have not changed for decades.

The influence of scale is somewhat exaggerated. Firstly, the lime layer itself is not characterized by high heat-insulating qualities. Secondly, in a closed whirlpool the formation large quantity lime deposits are unlikely.
Regarding the core of the induction boiler, the content of the thesis is true. It is impossible for scale to form on it, even if the coolant is oversaturated with lime inclusions.

Deposits simply cannot adhere to a surface that constantly vibrates under the influence of electromagnetic field. In addition, water bubbles regularly form on the core, which destroy any scale. Obviously, this statement is true for induction boilers, but not true for other electric heating devices.

Silence

Claim: There is absolutely no noise when operating induction equipment. This sets it apart from other electric analogues.

Vortex induction boiler

Any electric boiler does not make noise when heating water, because there are simply no acoustic vibrations.
Noise can only be created circulation pumps. However, if the operation of the heating system is based on the use of convection currents, then this noise will be eliminated.
If hydraulic resistance forces you to resort to forced circulation, there are many silent pumps for heating systems on the market today. So the sellers' statements in this case are quite fair.

Compactness

Statement: the dimensions of induction boilers are small, which allows them to be installed in any room.

Reality: this is actually true. The devices are a piece of pipe that does not require separate place. The thesis does not distort reality at all.

Safety

Statement: the boiler is absolutely safe.

Realities: in the event of a coolant leak, the electromagnetic field will not automatically disappear. Heating of the core will continue, and if the power supply is not interrupted, the mount and housing will melt in a few seconds.

Therefore, during installation it is necessary to provide for automatic shutdown of the boiler in such a situation. So the safety of the boiler is at the same level as in heating equipment.

Having decided to heat their home with electricity or install an additional electric heat source, homeowners are wondering what type of heater to use? The choice here is small; three types of electric heat generators are offered on the market: heating elements, electrode and vortex (induction). The latter are of the greatest interest, since they are declared by manufacturers as new and the most economical equipment. Induction boilers appeared relatively recently, so it is worth studying them in more detail.

Design of a vortex induction boiler

In fact, this technical solution is far from new; the phenomenon of electromagnetic induction, due to which electric induction heating boilers operate, was discovered by M. Faraday back in 1831. Just thanks modern materials and technology, the phenomenon was taken as a basis and implemented in water heating installations relatively recently.

Heating of water occurs due to eddy currents (Foucault currents) appearing in the core of the coil. They are formed under the influence of variable electric field created by the turns of the coil alternating current frequency 50 Hz. The core is made in the form of a pipe, through which the coolant flows when heated. Essentially, the device is an induction converter electrical energy to thermal with an efficiency of about 98%. The diameter of the wire from which the coil is made, the number of turns and the dimensions of the core are designed in such a way as to heat the water to a maximum temperature of 95 ºС and at the same time prevent overheating of the winding.

Water heaters type "VIN"

The heart of the unit is a coil consisting of a large number of turns of insulated wire, and placed vertically in a cylindrical housing in the form of a vessel. A metal rod is inserted inside the coil. The housing is hermetically sealed at the top and bottom with welded lids, terminals for connection to electrical network. Cold coolant enters the vessel through the lower pipe, which fills the entire space inside the body. Water heated to the required temperature goes into the heating system through the upper pipe.

Due to its design, when connected to the network, the heat generator constantly operates at full power, since to supply heating installation additional voltage regulation devices are irrational. It is much easier to use cyclic heating and use automatic shutdown/on with a water temperature sensor. You just need to set required temperature on the remote display electronic unit and it will heat the coolant to this temperature, turning off the water heating induction element when it is reached. After the time has passed and the water has cooled by a few degrees, the automation will turn on the heating again, this cycle will be repeated constantly.

Since the heat generator winding provides single-phase connection with a supply voltage of 220 V, induction heating units are not produced with high power. The reason is that the current in the circuit is too high (over 50 amperes), it will require laying large cross-section cables, which in itself is very expensive. To increase power, it is enough to put three water heating units in a cascade and use a three-phase connection with a supply voltage of 380 V. Connect a separate phase to each device in the cascade, the photo shows similar example induction heating operation.

Design features of heaters of the “Sibtekhnomash” type
Using the same effect of electromagnetic induction, another company develops and produces water heating devices of a slightly different design that deserves attention. The fact is that electric field, created by a multi-turn coil, has a spatial shape and extends from it in all directions. If in VIN units the coolant passes inside the coil, then the Sibtekhnomash induction boiler device provides a spiral-shaped heat exchanger located outside the winding, as shown in the figure.

The winding creates an alternating electric field around itself, eddy currents heat the turns of the heat exchanger pipe in which water moves. Coils with coils are assembled in a cascade of 3 pieces and attached to a common frame. Each of them is connected to a separate phase, the supply voltage is 380 V. The Sibtekhnomash design has several advantages:

induction heaters have a separate, collapsible design;
in the zone of action of the electric field there is an increased area of the heating surface and a larger amount of water due to the spiral circuit, which increases the heating rate;
Heat exchanger piping is accessible for cleaning and maintenance.

Despite the differences in the design of the heat generator, its operating efficiency is 98%, as in heaters of the “VIN” type, this efficiency value is declared by the manufacturer itself. The durability of the units in both cases is determined by the performance of the coils, or more precisely, by the service life of the winding and electrical insulation; manufacturers set this indicator within 30 years.

Advantages and disadvantages

The real advantages that induction boilers have for heating a home or industrial building are as follows:

High, as with all water heating installations, operating efficiency is in the range of 97-98%.
Durability due to the absence of moving parts and simplicity of design.
Small dimensions allowing heating equipment to be placed in a room of any size.
High heating rate of the coolant and lack of inertia when it is turned off.
Comfort during operation, an induction electric boiler does not require constant attention from the owner of the house, and the frequency of its maintenance depends entirely on the quality of the water used in the system.

Vortex heaters are supplied with automatic control kits, which makes it possible to connect heat generators with other climate systems at home.

Sectional view of the heater

This equipment also has disadvantages. The main one is the high cost, especially for heat generators of the Sibtekhnomash type. While using these units for industrial purposes is quite acceptable, induction heating of a private home may turn out to be unreasonably expensive.

Experience practical use The availability of vortex heaters by homeowners and maintenance personnel of service companies is not yet very extensive, but at the moment there are no significant complaints about the equipment.

Myths about induction boilers

One of the most popular myths is created by sales representatives selling induction electric boilers. The bottom line is that these boilers are supposedly 20-30% more efficient than other heating electrical installations, especially heating elements. This information is not true, since all heat generators that convert electricity into heat operate with an efficiency of at least 96% in accordance with the physical law of conservation of energy. The only undeniable fact is that heating elements heat up the coolant a little longer due to their multilayer structure. The tungsten coil heats up first quartz sand, then the tube material, and then the water. In this case, energy is not lost anywhere, and the efficiency of the heating element unit is 98%, the same as the vortex unit.

Example of a heating system

Another myth is that an induction electric boiler requires no maintenance at all, since the alternating magnetic field prevents deposits from settling on the heating elements. This question depends on the quality of the water and scale appears on the coil core in the same way as in heating element heaters if the coolant is not desalted. Therefore, at least once every 2 years, the heat generator itself and the heating system must undergo a flushing procedure.

Contrary to the assurances of the sellers, the water heater cannot be installed in any room. There are two reasons: the danger of electric shock and the presence of an electromagnetic field around the device. It is better to place it in technical room with limited access (boiler room).

Conclusion

Heating installations that use eddy currents for heating do have many advantages, especially the heating speed, compactness and durability. To what extent do these advantages justify high cost products - each homeowner will have to decide individually.

Induction heating methods have found wide application in industry, in particular in melting and hardening processes various kinds metals However, if desired, induction heating can be used for heating living spaces, heating water, and even quickly heating food. The main advantage of induction heaters is high efficiency with low energy consumption.

There are 2 main options that you can implement with your own hands: a full-fledged water boiler and a relatively small electrical device, connected directly to heating batteries. Check out the features of the proposed solutions and choose the most suitable one for your case.

Before you begin, take the time to prepare everyone necessary accessories so as not to be distracted by searching for them in the future. The assembly of the units in question does not require the use of complex tools and expensive materials. Everything you need is sold in hardware and plumbing stores.

Set for arranging induction heating

Soldering iron.
Welding machine. It is best to build this kind of system using inverter units. In general, a simple welding transformer will do.
Wire cutters.
Stainless steel wire with a diameter of about 6-7 mm.
Enameled copper wire 1.5-2 mm.
Steel pipes with a diameter of about 2.5 cm.
Plastic pipe with a diameter of 5 cm.
Explosion valve and other plumbing fittings.
Parts for assembling the circuit.

Water induction boiler

Pre-prepare a welding machine with the ability to adjust the current to 18-25A. Also prepare stainless steel wire. The structural elements responsible for heating the water will be assembled from it. If suitable wire is not available, wire rod scraps can be used.

First stage. Cut the stainless wire into pieces 4-5 cm long.

Second phase. Make the heater body. To make it, use a thick-walled plastic pipe. A product with a diameter of about 5 cm will be sufficient. Cover one end of the tube with a mesh with small cells. Fill the second open end with cut stainless wire or rod to the top of the pipe.

Third stage. Make an inductor coil. To do this, take copper wire with enamel and wrap it around the previously prepared heater body. The number of turns can vary from 85 to 95. Exact value depends on the amperage of the inductor used. Wind the coil in the center of the main pipe, which serves as the body of a homemade heater.

Fourth stage. Connect the assembled product to the heating system or water supply. To connect, use the appropriate adapters.

To transform the product into a full-fledged vortex induction heating unit, you need to perform certain additional steps.

First step. Weld two pipes into a product similar in shape to a donut. This product will serve as a water boiler.

Second step. Buy or weld yourself a tank of a diameter suitable for your case and cut into its body a pipe for the liquid outlet (at the bottom) and a similar pipe for the water supply (closer to the top).

Third step. Insert the induction coil prepared in the previous part of the instructions into the housing. Connect the “donut” to the water pipes so that it is placed strictly in the middle in the inductor housing.

Fourth step. Carefully insulate the output ends of the coil and connect to the transformer device.

Finally, all you have to do is cover the heater with an insulating screen so that as much of the heat as possible is retained inside the unit.

The principle of operation of such a device is extremely simple: water passes through pipes inside the coil, is heated, and exits through the corresponding pipe already hot. This unit is suitable for use exclusively in closed heating systems, in which a pump is used to circulate water.

If desired, the homemade heater in question can be connected to a heating or plumbing system assembled using plastic pipes.

In accordance with safety requirements, such equipment must be installed at a distance of at least 35-40 cm from the walls and 85-90 cm from the ceiling and floor surfaces.

Additionally, a valve must be installed on the boiler pipe to remove excess air.

If you wish, you can connect the heater to a heating radiator and use the resulting structure to heat a specific room, and not the entire house.

Electronic induction heating

The second heating option, which can be implemented on your own without any problems, is based on the use of advances in modern electrical engineering. The presented scheme does not require any additional configuration - you can start using it after the assembly is completed.

The operation of the circuit is based on the positions of the series resonance. Even a product of small dimensions will have quite impressive power. To further increase power, you can use capacitors with a higher capacity, as well as field switches with increased performance.

First step. Prepare the throttle. The mentioned part from a computer power supply is perfect. You can also always buy new components.

Second step. Prepare a ring of powdered iron. You need to wind 10-30 turns of 1.5 mm wire on it.

Third step. Prepare the necessary components. Transistors of the IRF740 brand are perfect. If they are missing, select parts with similar resistance. The reverse voltage of the diodes should be at least 500V, the optimal current value should be from 3-4A. For example, UF4007 diodes have these characteristics. Also buy 15-18 V zener diodes. Optimal power– 2-3 W. Resistors should have a power of 0.5 W.

Fourth step. Build a circuit and make an induction coil. To make a coil, use 1.5 mm wire. 6-7 turns will be enough. Attach the coil to the product assembled in accordance with the diagram above and turn it on.

The circuit is extremely simple, but the power of the product will be quite high. Under the influence of the generated heat, transistors can fail. To prevent this from happening, install them on radiators.

To connect such a heater, you also don’t have to take any complicated actions - you simply connect it to the battery and use the resulting system to heat the room. If necessary, you can easily assemble required quantity such heaters for all other rooms of the house.

Having the skills to work with the simplest tools, you can make a homemade one without any problems. induction heater. Do everything according to the instructions, remember safety precautions, and very soon your home will be warm.

Good luck!