RU2642818C1 - Electric steam generator - Google Patents

Abstract

FIELD: electricity.

SUBSTANCE: electric steamer consists of one or more electrical transformers with gang metal cores and primary winding, secondary tubular winding located in the magnetic field in isolation, jumper strap connected externally with the turns of a common tubular secondary winding with the aim of creating a short circuit of tubular secondary winding turns and the necessary means to forced fluid supply through the inner cavity of the tubular secondary winding, the last is made of three series-connected sections, connected by split sleeves of different heat capacity corresponding to phases of heat transformation of water into steam.

EFFECT: use of the invention makes it possible to increase the reliability of the induction electric steam generator.

3 cl, 3 dwg

Description

FIELD OF THE INVENTION

The invention relates to a method and apparatus for converting electrical energy into heat and creating heat transfer. It can be used for heating liquids, for example, in heating systems and hot steam and water supply of industrial and residential facilities, as well as in other applications where heating and evaporation of fluids is required.

State of the art

Known electric steam generator, adopted by us for the prototype, including an electric transformer having a type-setting metal core designed to create a closed magnetic field, a primary winding located on the core and electrically isolated from it, a tubular secondary winding located in an isolated magnetic field, a jumper connected externally with turns of a tubular secondary winding in order to create a short circuit of turns of a tubular secondary winding, and the necessary means for forced flow of fluid through the inner cavity of the tubular secondary winding. (US 1999446)

The known device relates to highly efficient devices for converting electrical energy into heat due to the direct contact between the heated fluid and the heating surface in the inner cavity of the secondary short-circuited tubular winding. To obtain steam in a known device, it is required either to achieve a temperature of the tubular winding above 212 degrees, or to preheat the feed water before supplying it to the tubular winding. The latter is carried out by introducing an additional tubular short-circuited secondary winding designed to pre-heat the liquid before feeding it into the main short-circuited tubular winding for evaporation. The amount of steam generated by such a device directly depends on the flow rate (flow rate) of the liquid. If the calculated liquid flow rate through the device is exceeded, steam ceases to be produced, because there is not enough energy for evaporation, and with a decrease in liquid flow below the calculated one, the tubular secondary winding is poorly cooled and overheats to an emergency temperature. Despite the high efficiency, the known device in its design is too sensitive to control parameters - the magnitude of the current, voltage, temperature of the input feed water, water flow, which are derivatives of each specific design. For each flow rate of water, it is necessary to calculate the heating temperature of the secondary winding, operating current, voltage, pipe diameter, pipe material. A change in the course of operation of at least one of the parameters leads to a deterioration in the quality of the steam generated by the device, or to its emergency emergency stop. The current or voltage can be controlled within very narrow limits, since the amount of heat generated in the device is proportional to the square of the current or voltage, changes of which very quickly lead to a loss of functionality of the device.

The known device belongs to the class of direct-flow steam generators, where the movement of liquid and steam through the pipes is carried out by the method of forced pressure using a feed pump, which provides overcoming of the total resistance to the movement of the vapor-liquid medium through the pipes and the specified steam pressure at the outlet. A common disadvantage of this method, both in the case of flame tube heating and electric heating of pipes, is their low heat storage capacity (see page 266 in the book by A. P. Kovalev. Steam generators: A textbook for universities. - M.: Energoatomizdat, 1985. - 386 s., ill.). This disadvantage is especially manifested in the known device adopted for the prototype, since the length of the tubular secondary winding is associated with its electrical resistance and often does not have sufficient heat transfer area due to shortage of length. Therefore, a reliable implementation of the once-through method for producing steam using a known device adopted as a prototype is possible only by making design changes that take into account the nature of the movement of fluid in the pipe of the once-through steam generator and the conversion of fluid during movement through the pipe into steam.

SUMMARY OF THE INVENTION

The problem solved by the claimed invention is the creation of a reliable induction electric steam generator.

The technical result of the claimed invention is to increase the reliability of the induction electric steam generator.

The technical result of the claimed invention is achieved due to the fact that the electric steam generator includes one or more electric transformers having stacked metal cores, primary windings located on the cores and electrically isolated from them,

a common tubular secondary winding located in a magnetic field in isolation and covering all racks of type-setting metal cores of transformers,

a jumper located on a common tubular secondary winding,

and means for forcing fluid through the internal cavity of the common tubular secondary winding,

in this case, the common tubular secondary winding is made up of heating, evaporation and superheating metal sections connected in series, differing from each other in terms of resistance to electric current, so that when electric current passes through each section, heat power is released corresponding to the phase of thermal conversion of water into steam when water moves in the inner cavity of the tubular secondary winding,

and the jumper is made of two parts that connect externally the turns of the common metal tubular secondary winding in a plane perpendicular to the turns, with the possibility of creating a short circuit of the turns of the common tubular secondary winding at the points of intersection of the circumference of the outer surface of the common tubular secondary winding with their diameters parallel to the direction of the total magnetic vector induction in stacked metal cores so that nearby points are interconnected electrically by one part of a composite ne jumpers, and remote points are interconnected electrically by another part of the composite jumpers.

In the particular case of the implementation of the claimed technical solution, temperature control sensors are installed on the outer surface of the secondary tubular winding in the area of each said section of the common tubular secondary winding.

In the particular case of the implementation of the claimed technical solution, the jumper components are made in the form of an arc of a ring.

From the practice of creating devices that implement a direct-flow method for producing steam, it is known that the active length of heating a heating pipe of a direct-flow steam generator is conventionally divided into three successive parts: water, steam, and water. The position of the boundaries of these sections depends on the amount of energy supplied and the flow rate of feed water (steam production). With an increase in the amount of energy supplied or a decrease in the flow of feed water, an emergency situation in the form of a burn-out of the heating pipe is possible. The smaller the design of the device is sensitive to the shift of the boundaries of sequential heating, the more reliable the steam generator is and the cheaper its control system.

Brief Description of the Drawings

Details, features, and advantages of the present invention follow from the following description of embodiments of the claimed technical solution using the drawings, which show:

FIG. 1 is a general view of an electric steam generator;

FIG. 2 - tubular secondary winding;

FIG. 3 - jumper to create a short circuit of the tubular secondary winding.

In the figures, the numbers indicate the following positions:

1 - metal core; 2 - primary winding; 3 - secondary tubular winding; 4 - jumper; 5 - jumper; 6 - outlet pipe; 7 - heating section of the secondary tubular winding; 8 - evaporative section of the secondary tubular winding; 9 - overheating section of the secondary tubular winding; 10 - temperature control sensor; 11 - support; 12-metering valve; 13 - coupling; 14 - coupling.

Disclosure of invention

An electric steam generator consists of stacked metal cores (1) designed to create a closed magnetic field, on which primary windings (2) isolated from metal cores (1) are located.

The common secondary tubular winding (3) is installed in isolation in a magnetic field on supports (11), folded so that it covers all racks of stacked metal cores (1), and is equipped with a jumper made of two parts - a metal arc of the ring (4) connected externally with turns of the secondary tubular winding (3), and an arc of the ring (5) connected externally to the turns of the secondary tubular winding (3), all connections are on the same line in a plane perpendicular to the axis of the pipes of the secondary tubular winding (3), together both parts of the jumper (4) and (5) create secure short-circuiting turns of the secondary winding tube (3) capable of conducting alternating current high value.

A jumper made of two parts connecting the external turns of the common metal tubular secondary winding in a plane perpendicular to the turns in order to create a short circuit of the turns of the tubular secondary winding at the points of intersection of the circumference of the outer surface of the tubular secondary winding with their diameters parallel to the direction of the total magnetic induction vector in stacked metal cores so that nearby points are interconnected electrically by one part of a composite jumper in the form of and rings, and distant points interconnected electrically integral part of another bridge in the form of arcs of the ring.

The secondary tubular winding (3) consists of a heating section (7), an evaporation section (8) and an overheating section (9). Sections (7, 8, 9) of the secondary tubular winding are connected in series by couplings (13) and (14). Clutches (13) and (14) can be detachable, which creates additional convenience for servicing the secondary tubular winding (3) during operation. Sections (7, 8, 9) of the secondary tubular winding can have the same or different diameter of the inner cavity and different electrical resistance.

The location of the boundaries between the heating (7), evaporative (8) and superheating (9) sections is chosen so that the thermal parameters in the steam-water straight-through path of the tubular secondary winding (3) are as close as possible to the process of converting liquid into steam at a given device power and the length of the tubular secondary winding (3), which allows to minimize the disadvantages associated with its low heat storage ability, and to achieve stable operation of the device as a whole

The electrical resistance of the sections (7, 8, 9) of the secondary tubular winding is selected by calculation depending on the required heating temperature of the section. For example, in order to avoid burning out the section of the secondary tubular winding (3) at the steam outlet, it is necessary to slightly lower the heating temperature of the pipe, therefore a lower electrical resistance of the third section (9) is selected.

Means for forced fluid supply through the inner cavity of the tubular secondary winding include a metering valve (12) installed at the entrance to the inner cavity of the secondary tubular winding (3), and a discharge pipe (6) is installed at the outlet of the inner cavity of the secondary tubular winding (3). Moreover, temperature control sensors (10) are installed on the outer surface of the secondary tubular winding (3) in the area of sections (7), (8) and (9).

Also, the effect of increasing the stability and reliability of the steam generator is enhanced by increasing the number of transformers in the device, for example two transformers, as shown in FIG. 2, which leads to an elongation of the common tubular secondary winding (3), or by creating on the indicated principle the sectioning of the common secondary winding (3) from several turns. In both cases, lengthening the total secondary tubular winding (3) gives an increase in its heat storage capacity. As a result, an increase in the heat transfer area of the inner cavity due to the lengthening of the secondary tubular winding (3) leads to a decrease in the amount of precipitation in the steam-water path of the secondary tubular winding (3). This makes it possible to increase the efficiency of the device by increasing the power acting in the winding, the current of which is closed by means of a jumper - a metal arc of the ring (4), connected externally with the turns of the secondary tubular winding (3) (Fig. 3), and a jumper - of a metal arc rings (5) connected externally to the turns of the secondary tubular winding (3) in the same plane at the points of intersection of the outer surface of the pipes with their diameter parallel to the magnetic induction vector. Temperature sensors (10) mounted on the outer surface of the secondary tubular winding (3) provide visual and other monitoring of the device’s working process.

The device operates as follows.

First, with the help of a metering valve (12), fluid is moved through the internal cavity of the common tubular secondary winding (3). Then the primary windings (2) are connected to an alternating current network, and they induce an alternating magnetic flux in the stacked metal cores (1), under the influence of which an electric current occurs in the common secondary tubular winding (3), covering the magnetic flux in the cores (1) of large size, and the tubular secondary winding (3) is heated, while in section (7) of the tubular secondary winding, the liquid is brought to a boil, in section (8) it is evaporated and becomes a steam-water mixture, and in section (9) the resulting steam is heated to a predetermined pace Aturi and enters the discharge pipe (6) to the consumer.

The specific implementation of the device.

Two induction steam generators were developed and tested, both consisting of two transformers with a common secondary tubular winding of a copper pipe with a diameter of 22 mm, covering all racks of both transformers, as shown in FIG. 1. The first device had a power of 25 kW, the second - 50 kW. The test results showed that an induction steam generator in accordance with the present invention with a capacity of 25 kW produces 100 kg of steam / hour with a dry coefficient of steam of 30%, and a steam generator with a capacity of 50 kW gives 220 kg of steam / hour with coefficient. dryness of 40%.

Claims (8)

1. An electric steam generator comprising one or more electric transformers having stacked metal cores, primary windings located on the cores and electrically isolated from them, a common tubular secondary winding located in a magnetic field in isolation and covering all racks of type-setting metal cores of transformers, a jumper located on a common tubular secondary winding, and means for forcing fluid through the internal cavity of the common tubular secondary winding, in this case, the common tubular secondary winding is made up of heating, evaporation and superheating metal sections connected in series, differing from each other in terms of resistance to electric current, so that when electric current passes through each section, heat power is released corresponding to the phase of thermal conversion of water into steam when water moves in the inner cavity of the tubular secondary winding, and the jumper is made of two parts that connect externally the turns of the common metal tubular secondary winding in a plane perpendicular to the turns, with the possibility of creating a short circuit of the turns of the common tubular secondary winding at the points of intersection of the circumference of the outer surface of the common tubular secondary winding with their diameters parallel to the direction of the total magnetic vector induction in stacked metal cores so that nearby points are interconnected electrically by one part of a composite ne jumpers, and remote points are interconnected electrically by another part of the composite jumpers. 2. The steam generator according to claim 1, characterized in that temperature monitoring sensors are installed on the outer surface of the common tubular secondary winding in the area of each said section of the common tubular secondary winding. 3. The steam generator according to claim 1, characterized in that the components of the said jumpers are made in the form of an arc of a ring.

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