RU230328U1 - Induction heater with spiral heat exchanger - Google Patents

Abstract

The utility model relates to electrical engineering, namely to induction heaters, and can be used in various fields: technological, direct and indirect heating of various liquids, in heating systems and hot water supply of residential, domestic and industrial buildings. The technical result consists in eliminating the tendency of the structure to retain residual air at the outlet of the secondary winding from the heater. The induction heater with a spiral heat exchanger consists of a three-phase transformer with a core made of sheet electrical steel, with primary windings located on the rods of the core, connected to an AC electrical network, and three secondary conductive windings made of metal pipes wound around each primary winding of the transformer. The induction heater contains flanges for the input and output of the coolant and a drain pipe. All elements of the heater are assembled on a spatial frame. The current input is made with a terminal box and current-carrying buses. The secondary winding is made with a negative slope in the coolant input zone and with a positive slope in the coolant output zone. 8 fig.

Description

The proposed technical solution - utility model relates to the field of electrical engineering and electric power engineering, namely to induction heaters, and can be used in various areas: technological, direct and indirect heating of various liquids, in hot water supply systems and heating of residential, domestic and industrial buildings.

An induction heater for fluids is known [1], which is a three-phase transformer with a ferromagnetic core, with a primary winding located on the rods, connected to an alternating current network, and a secondary electrically conductive winding, which is a heat exchanger for the heated fluid, consisting of three chambers for heating the fluid, each of which is made of two cylinders of different diameters, installed concentrically one inside the other, connected at the top and bottom by end plugs to form a sealed hollow chamber for heating the fluid in it, inside which rods with a primary winding are installed. The pipeline for feeding the fluid into the heating chambers is installed at the bottom of the induction heater, two nozzles for the fluid inlet into the first and second heating chambers respectively are connected in parallel to each other to the pipeline, the end of the pipeline for feeding the fluid is connected directly to the third heating chamber along the flow of the fluid, the pipeline for the outlet of the fluid is installed at the top of the induction heater, the end of the pipeline for the outlet of the fluid is connected to the first or third heating chamber, two other nozzles for the outlet of the fluid from the heating chambers are connected in parallel to each other to the pipeline. The nozzles and the end of the pipeline for feeding the fluid can be installed on the lower cylindrical part of the chambers.

The disadvantage of the above-mentioned induction heater is the high labor intensity of its manufacture, due to the need to manufacture three separate capacitive chambers from sheet material, three separate pipe sections for supplying the coolant to each heating chamber from pipe material, three separate pipe sections for removing the coolant from each heating chamber and providing connecting pipelines on the supply and removal connected to three corresponding branch pipes with bends, as well as taking into account the variable size of all elements depending on the heater power.

An induction heater for fluid media is known [2] comprising a flat ferromagnetic core with rods on which a primary winding coil is wound, connected to an alternating current source, and an electrically conductive secondary winding inductively coupled to the primary winding coil through the core, which is a heat exchanger for the fluid medium being heated, provided with pipes for the input and output of the fluid medium being heated and made of tubular elements located in the plane of the turns of the primary winding coil, wherein the core rods are installed so that the turns of the primary winding coil are located in a vertical plane, each tubular element is made in the form of a turn forming a closed loop around the corresponding core rod, wherein the sections of the tubular elements located in the intercoil space are truncated, and the truncated sections of the tubular elements, embracing adjacent rods and located in the same vertical plane, are connected to each other inseparably.

The disadvantage of the above-mentioned induction heater is the presence in the design of a large number of truncated tubular elements with a complex unifying profile of mutual adjacency of the elements of the circuit closure around each of the coils, which determines the technological complexity and labor intensity of the manufacture of these elements. Also in this design there is a large number of welded seams located in the zone of influence of the magnetic flux, which, due to the change in the structure of the metal after welding, increases the tendency for the seams to appear local overheating zones, which places high demands on the quality of welding, increasing the labor intensity and technological complexity of manufacture, and thereby reducing the degree of industrial applicability of the product.

An induction heater of liquid media is known [3 - prototype], consisting of a three-phase transformer with a core made of sheet electrical steel. Primary windings connected to a three-phase AC electrical network are located on the rods of the core. Three secondary windings made of metal pipes wound around each of the primary windings of the transformer in one layer are installed on the primary windings. The inputs and outputs of the pipes are hydraulically connected in parallel, and electrically closed by an external conductor. The diameter of the turn of the secondary winding, the number of turns of each of the secondary windings, as well as the winding height of each secondary winding are determined from the conditions of ensuring optimal ratios of the geometric and electrical parameters of the secondary winding of the transformer, which is the heat exchange element of the induction heater.

The disadvantage of the heater is the low degree of industrial applicability and reduced service life of the heater due to the tendency of the secondary winding design to retain residual air at the outlet from the upper part of the secondary winding of the heater, the precipitation of difficult-to-remove sediments from liquid media in the lower part of the secondary winding of the heater, which is subjected to intense heating during operation, and the absence of current input elements, temperature and pressure control inside the heater, which reduces both the safety of the heater and its service life.

The proposed technical solution - an induction heater with a spiral heat exchanger - is aimed at eliminating the identified shortcomings of the prototype and analogues, namely, eliminating the tendency of the design to retain residual air at the outlet of the secondary winding from the heater.

The proposed technical solution is shown in Fig. 1-8.

The induction heater with a spiral heat exchanger is a prefabricated unit. In Fig. 1, the spatial frame is designated by numeral 1, the three-phase transformer with a core made of sheet electrical steel is designated by numeral 2, the primary winding is designated by numeral 3, the secondary winding is designated by numeral 4, the coolant inlet flange is designated by numeral 5, the coolant outlet flange is designated by numeral 6, the coolant outlet flange is designated by numeral 7, the electric contact pressure gauge is designated by numeral 8, the temperature control sensor is designated by numeral 9, the terminal box is designated by numeral 10, the drain pipe is designated by numeral 11, the input transition is designated by numeral 12, the outlet transition is designated by numeral 13, and the current-carrying bus is designated by numeral 14.

The induction heater with a spiral heat exchanger operates as follows: there is a spatial frame 1 (see Fig. 1), on which a three-phase transformer with a core made of sheet electrical steel 2 is mounted, three primary windings 3 are located on the rods of the core, connected through a terminal box 9 to a three-phase electric network, excluding the shift of the current-carrying busbar 13. When an alternating electric current is supplied to the primary winding 3, a magnetic field arises, due to the action of eddy currents, the secondary winding 4 is heated, the coolant supplied from the system to the flange 5, through the input transition 11 (see Fig. 2), flows through the three secondary windings 4 (see Fig. 1), is heated due to heat exchange with the walls of the secondary windings 4, located in close proximity to the primary windings 3 and then enters through the branch transition 12 (see Fig. 2) to flange 6 (see Fig. 1) for feeding heated water into the system. The secondary winding 4 is structurally a metal pipe wound in a spiral and made of corrosion-resistant stainless steel. Depending on the heater power, the length and number of turns of the spiral of the pipe used increases without changing the diameter. The primary winding 3 is made in the form of a vertical hollow cylinder wound from aluminum wire with fiberglass insulation with a current input through a current-carrying busbar 13. Depending on the heater power, the amount of wire used in the primary winding increases without changing the type, brand and cross-section of the wire. For a better understanding of the design and execution of the heater, Fig. 3, 4, 5, 6, 7, 8. Depending on the heater power, different standard sizes of coolant inlet flange 5 (see Fig. 1) and coolant outlet flange 6 are used, which are made identical.

Due to the negative angle of inclination X (see Fig. 4) and the negative angle of inclination Y (see Fig. 5), performed within 1-15 degrees, in the area of the coolant input (see Fig. 6), the accumulation of sediments falling from the coolant in the zone of intensive heating is excluded, in the immediate vicinity of the primary winding 3 (see Fig. 1). The accumulation of sediments occurs in the transition of input 11 (see Fig. 2), which ensures unimpeded removal through the drain pipe 10.

Due to the positive angle of inclination X (see Fig. 4) and the positive angle of inclination Y (see Fig. 5), performed within 1-15 degrees, in the area of the coolant outlet (see Fig. 6), the retention of residual air in the secondary winding 4 is eliminated (see Fig. 2).

The electric contact pressure gauge 7 allows you to control the presence and limit the maximum permissible pressure of the coolant in the heater, which ensures trouble-free and safe operation.

Temperature control sensor 8 ensures control of the heater's operating temperature, which allows maintaining the set coolant temperature and increasing the heater's service life, eliminating overheating.

The drain pipe 10, located at the lower point of the transition of the input 11, allows for complete emptying of the heater from the coolant and its sediments, which increases the ease of use and increases the service life of the heater, due to the absence of accumulation of sediment deposit zones in the areas of intensive heating of the secondary winding 4.

The proposed utility model - Induction heater with a spiral heat exchanger - eliminates the tendency of the design to retain residual air at the outlet of the secondary winding from the heater.

Taking into account the factors stated above and eliminating the shortcomings of the prototype and analogues, due to the combination of the given design parameters of the specified induction heater with a spiral heat exchanger, the necessary technical result is achieved, reflecting the feasibility of implementing the specified design solutions and causing a significant increase in the degree of industrial applicability of the heater.

This technical solution has been tested in the manufacture of induction heaters with a spiral heat exchanger, confirmation of industrial applicability and economic feasibility has been received and it has been implemented into production.

Sources of information:

1. Patent of the Russian Federation No. 2371889, 2009.

2. Patent of the Russian Federation No. 2263418, 2005.

3. Patent of the Russian Federation No. 138284, 2014.

Claims (1)

An induction heater with a spiral heat exchanger consisting of a three-phase transformer with a core made of sheet electrical steel, with primary windings located on the rods of the core, connected to an alternating current electrical network, and three secondary conductive windings made of metal pipes wound around each primary winding of the transformer, characterized in that the induction heater contains coolant input and output flanges and a drain pipe, wherein all elements of the heater are assembled on a spatial frame, the current input is made with a terminal box and current-carrying buses, the secondary winding is made with a negative slope in the coolant input zone and with a positive slope in the coolant outlet zone.