Start of section
Production, amateur
Radio amateurs
Aircraft model, rocket-model
Useful, entertaining 		Stealth Master
Electronics
Physics
Technologies
Inventions 		Secrets of the cosmos
Secrets of the Earth
Secrets of the Ocean
Tricks
Map of section
Start
Forum
Use of the site materials is allowed subject to the link (for websites - hyperlinks)

Navigation: =>

Home / Patent catalog / Catalog section / Back /

THERMAL DEVICES, DEVICES FOR HEATING LIQUID MEDIA AND THEIR APPLICATION
INVENTION
Patent of the Russian Federation RU2074529

INDUCTION HEATER OF LIQUID

The name of the inventor: Elshin AI; Kazansky V.M .; Karmanov E.D.
The name of the patent holder: Elshin Anatoly Ivanovich
Address for correspondence:
Date of commencement of the patent: 1995.04.04

SUMMARY OF THE INVENTION: The induction liquid heater comprises a housing accommodated therein by a multi-core ferromagnetic core transformer with a multiphase primary winding connected to the alternating current network on the rods and a secondary winding being a heat exchanger made as a hollow chamber with a lower inlet and upper outlet nozzles For passage of a heated liquid. The chamber has through vertical channels with electrically conductive walls, in each of which the rods of the transformer core are installed with a clearance. The proposed induction liquid heater has a high efficiency and a reduced material consumption.

DESCRIPTION OF THE INVENTION

The invention relates to electrical engineering and can be used for heating liquids, in particular for electric heating and hot water supply.

Induction heaters for liquids have been known for a long time, for example, "a vessel that uses an iron core of a transformer for induction heating of a liquid" (German patent No. 329131, class 21 H, group 3 with priority from January 22, 1918 ), which has not received practical application due to A large specific material consumption and low energy performance (efficiency of conversion of electricity to heat and power factor ).

However, the undeniable advantages of low-frequency ( 50-60 Hz ) induction liquid heaters in relation to modern electrical safety and fire safety requirements in comparison with heaters of resistor type ( TEN ) and electrode (for water) have led to increased interest in new designs of induction heaters. These include the well-known modern induction heaters of submerged liquid, including an induction liquid heater ( Russian Patent No. 2002383, cl. H 05 B 6/10 ), containing a hermetic casing of cylindrical shape, to the inner surface of the outer wall of which the induction winding is attached, in The internal diameter of the outer wall of the heater body is more than 1/3 of its height, and the thickness of this wall does not exceed half the depth of penetration of the alternating electromagnetic field into the housing material (at the frequency of the power network).

The drawbacks of this induction submersible heater are:

  • Limited operating conditions: an external volume is required for the heated liquid, additional devices (or forces) are required to manipulate the immersion heater of a comparatively large mass in this volume, the internal volume of the heater occupies a relatively large fraction in the volume with the heated liquid, an additional device is necessary to prevent accidental electric Entering into the heated liquid;
  • Increased material consumption of the heater per unit of power, especially the ferromagnetic core;
  • Insufficient energy performance, in particular the power factor ( ), Since the induction heating of the housing wall is due to magnetic fluxes of scattering, including with a ferromagnetic thin wall, since it will operate in saturation mode;
  • A sufficiently intense thermal regime of the primary winding located inside the shell, which will be strengthened as scale is formed and the salts are precipitated on the surface of the heating body of the heater; In emergency mode, in the event of a breach of the hermeticity of the housing, there may be a dangerous electrical potential on the heated water.

There are known submerged induction liquid heaters having improved energy indices, for example an induction heater of a liquid medium (USSR AS No. 1811038, class H 05 6/10) and an identical induction liquid heater (Russian Patent No. 2002384, class H 05 B 6 / 10 ) containing an annular magnetic core of a transformer with a toroidal primary winding that is hermetically enclosed in an annular chamber of an electrically conductive material, which is a secondary short-circuited winding and serves as a heating element. Disadvantages of these induction heaters, in addition to energy indicators, are similar to the above heater according to the Russian patent No. 2002383, cl. Н 05 В 6/10 .

In addition, the induction heaters listed above do not constructively allow the use of existing standard sizes of traditional transformers and their production technology, including three-phase ones.

An induction electric liquid heater is known, which makes it possible to use constructs and technology of manufacturing traditional three-phase transformers at the request of France N 2565059, cl. H 05 B 6/10 , comprising a laminated core with a primary winding connected to the mains, and a secondary winding made in the form of a short-circuited element from electrically conductive tubes in which liquid is heated by heating losses due to short-circuit currents of the secondary winding.

The drawbacks of this electric heater include the limited coefficient of the beneficial conversion of electrical energy into heat for heating the liquid because of the thermal dispersion of the outer surface of the coil, increased hydraulic resistance of the heating coils of the coil, which hinders the circulation of the heated liquid.

The closest in technical essence to the proposed is the induction liquid heater (US Patent No. 4602140, cl. H 05 B 6/10, 219-10.51) containing a transformer with a multi-core ferromagnetic core, on the rods of which a primary winding is wound, connected to an alternating current network (Three-phase). The secondary winding, inductively coupled to the primary through the core, is a system of straight tubes of electrically conductive material passing outside the core cores perpendicular to them and parallel to the turns of the primary winding and electrically closed at the ends by electrically conductive non-magnetic plates. This system of tubes, heated by currents induced in them (short circuit), is a heat exchanger in which the heat carrier is heated.

The disadvantages of the prototype include:

  • Reducing the efficiency of conversion of electrical energy into heat for heating the liquid due to thermal dissipation into the environment from the outer surface of the heating tubes (which, in particular, is equal to the surface of conductive heating of the liquid circulating through them);
  • Increased material consumption, mainly of the ferromagnetic core, because of the increased sizes of the inter-coil windows necessary to accommodate, in addition to the primary winding, the corresponding heating coil tube system.

The object of the invention is to provide an induction liquid heater with a higher efficiency and a lower material capacity.

This is achieved by the fact that in an induction liquid heater comprising a housing, a multi-core ferromagnetic core transformer with a multiphase primary winding connected to the alternating current network and a secondary winding that is a heat exchanger located on the rods, the heat exchanger is made in the form of a hollow chamber with a lower Inlet and outlet nozzles for passing a heated liquid in which there are through-going vertical channels with electrically conductive walls, in each of which a core of the transformer core is installed with a clearance.

And the induction liquid heater can be provided with closed contours of various geometries arranged around each through channel, made of an electrically conductive material.

The body of the induction liquid heater can be filled with a liquid dielectric.

In the drawing, an induction liquid heater, section, is shown.

INDUCTION HEATER OF LIQUID. Patent of the Russian Federation RU2074529

The induction liquid heater contains a laminated multi-rod (for example, three-phase) ferromagnetic transformer core 1 with a multiphase primary winding 2 located on the core cores connected to the mains and insulated from the rods by the casing insulation 3.

The secondary winding of the transformer is a heat exchanger and is made in the form of a hollow chamber 4 with a lower inlet 5 and an upper outlet 6 to pass a heated liquid, the chamber has through vertical channels 7 with electrically conductive walls 8 (in terms of the number of core rods), each of which is fitted with a gap Core rods 1. There are air gaps between the surfaces of the walls 8 and the primary winding 2 with insulation 3.

The hollow chamber 4 is made of a sheet material, wherein the cylindrical electroconductive walls 8 of the through channels 7, the side shell 9, the lower end 10 and the upper end 11 forming the integrity and impermeability to the heated liquid of the chamber 4 volume (for example, by welding) Different thicknesses and different materials.

To enhance the efficiency of the heater, it can be provided with closed electrically conductive contours of various sizes and shapes, for example in the form of rings 12 and 13 mounted around each channel 7.

If necessary, the housing 14 with the appropriate hermetic outlets for the branch pipes 5 and 6 can be filled with a liquid dielectric.

The proposed induction liquid heater functions as follows. After filling the chamber 4 with a heated liquid, the primary winding 2 is connected to a three-phase current network and magnetic fluxes are created in the cores of the transformer core 1, differing in phase by 120 electrical degrees. Under the influence of these flows (variables in time), sufficiently large currents (measured by kilo amperes) are induced in the walls of the 8 phase channels 7. Proportional to the square of these currents, the main thermal energy is generated in the walls 8, heating the liquid in the chamber 4. In the lower 10 and upper 11 end walls of the chamber 4, a secondary current system is induced, causing additional heat release in the electroconductive material of the end bases 10 and 11 and the corresponding heating (bottom and Top) of the liquid in chamber 4.

To intensify induction heating of liquids in the proposed heater, it is possible to use thermal concentrators in the form of electrically conductive circuits closed around the walls 8 of each phase channel 7 (for example, rings 12 and 13 (see the drawing), including corrugated ones). In these rings 12 and 13 some of the electricity is converted into heat, and their surface is fully involved in direct heat exchange with the heated liquid.

When operating the proposed induction liquid heater, a certain temperature difference forms between the upper layers of the liquid (in the outlet zone 6) and the cold layers of the liquid at the inlet (branch pipe 5) into chamber 4.

Under the influence of this temperature drop, a natural circulation of the heated liquid in the chamber 4 and closing it through the pipes 5 and 6 to the system of tanks for the heated heating medium (for example, the electric heating system) is provided. The circulation of the heating medium can be strengthened by means of an external pump if necessary.

The outer casing 14 can be filled with a liquid dielectric, for example transformer oil, depending on the power of the induction liquid heater and the supply network voltage.

The technical effect of the proposed induction electric liquid heater in comparison with the prototype is as follows:

It is possible to increase the efficiency of conversion of electrical energy into thermal energy as a result of more complete use of electricity converted into heat for heating the liquid, since the wall 9, the largest part of the surface of the chamber 4, is not heat generating, and the heat transfer from the outer surface of the walls 8 of the phase channels 7 towards the primary The windings practically do not occur because of the small temperature difference between them;

In the heater with the contours in the form of rings 12 and 13, the walls of the chamber 4 can be made of a non-electrically conductive material, with all the thermal power released in the rings 12 and 13;

A smaller specific material consumption of the induction heater is provided, mainly the mass of the ferromagnetic core 1, the dimensions of the windows between the rods are practically determined only by the dimensions of the coils of the primary winding 2, since the walls 8 of the phase channels 7 are made of sheet material and slightly affect the sizes of the multi-rod transformer windows, The relation of the geometry of the rings 12 and 13 ensures the uniformity of the heating of the liquid in the chamber 4.

In addition, the induction liquid heater according to the invention is more simple to install due to the lack of a multi-tubular heat exchanger in comparison with the prototype.

CLAIM

  1. An induction liquid heater comprising a housing housed therein a multi-core ferromagnetic core transformer with a multiphase primary winding connected to the alternating current network on the rods and a secondary winding being a heat exchanger, characterized in that the heat exchanger is made as a hollow chamber with a lower inlet and Upper outlet nozzles for passing the heated liquid, in which there are through vertical channels with electrically conductive walls, in each of which a core of the transformer core is installed with a gap.

  2. The heater of claim 1, characterized in that it is provided with closed loops mounted around each said through-passage, made of an electrically conductive material.

  3. The heater according to claim 1 or 2, characterized in that the body is filled with a liquid dielectric.

print version
Date of publication 11/30/2006