RU2417563C2 - Plant of induction liquid heating - Google Patents

Abstract

FIELD: electricity.

SUBSTANCE: plant of induction heating of pipelines comprises a device of conversion and control, a heat exchanger, besides, the conversion and control device is arranged on the basis of an autonomous current inverter with quasiresonant switching, the load of which is an inducting wire, representing a multiple-core copper conductor in heat-resistant insulation, arranged on surface of the heat exchanger along its whole length in a single turn, and the heat exchanger represents a system of pipelines, inside which plates of magnetic materials are radially arranged along whole length.

EFFECT: invention makes it possible to increase efficiency factor of heating system heat transfer, to increase controllability of heat transfer processes, to increase capacity and area of thermal field exposure.

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Description

The invention relates to the field of electrothermics and can be used in the oil, gas, chemical and food industries to maintain the temperature of pipelines in the operating range, as well as to protect against freezing of pipelines and starting heating of pipelines to operating temperature.

Known installation of technological heating - high-speed oil heater SPI, created on the basis of induction heaters and designed to heat liquids in process pipelines using an intermediate coolant / 1 /. The installation is a two-circuit scheme, the first circuit of which consists of an induction heater and a high-speed heat exchanger, the second circuit is a high-speed heat exchanger and a heated pipeline. A heat exchanger is a pipe-in-pipe system in which heating occurs from an intermediate heat carrier located in the outer pipe to a heated product located in the inner pipe.

The disadvantages of SPN include the relatively low heat transfer efficiency due to the use of an intermediate heat carrier, poor controllability of the heat field power due to operation at an industrial frequency, limitation of the maximum heat field power (up to 250 kW), and the complicated design of the heat exchanger.

The closest in technical essence to the proposed one is the inductive-conductive electric heater "Geyser", in which there is no intermediate heat carrier, heat transfer occurs from the heat exchanger to the heated fluid with a higher heat transfer efficiency / 2, 3 /. Inductive-conductive electric heater "Geyser" contains a conversion and control device, which is a transformer, the primary winding of which acts as an induction wire, and the secondary winding is a ferromagnetic heat exchanger and acts as a transformer load, the parameters of the elements of the electric heater are designed in such a way that the apparatus operates in continuous operation without overheating.

The disadvantages of this system include low controllability of the heat transfer process due to operation at an industrial frequency, low operating temperature range (up to 250 ° C), limited power (up to 250 kW) and the area of exposure to the thermal field (due to the design of the heat exchanger).

The technical objectives of the invention are to increase the heat transfer efficiency of the heating system, increase the controllability of heat transfer processes, increase the power and the area of the influence of the thermal field.

The problem is achieved in that in the known induction heating installation, consisting of a conversion and control device, a heat exchanger, the conversion and control device is based on an autonomous current inverter with quasi-resonant switching, the load of which is an induction wire, which is a multicore copper conductor in heat-resistant insulation, located on the surface of the heat exchanger along its entire length in one turn, forming a contour of complex geometry, and the heat exchanger is This is a coil made of a pipeline, inside of which plates of magnetic materials (for example, electrical steel) are radially located along the entire length.

On figa), b) presents the proposed installation of induction heating of the pipeline, comprising a conversion and control device 1, an induction wire 2, a heat exchanger 3 made of a pipeline, inside of which plates of magnetic materials are radially located along the entire length 4. It should be noted that direct and return wires for maximum impact on the heat exchanger are located relative to each other at the maximum possible distance equal to the diameter of the pipe. However, they can be located at a closer distance.

In Fig.2 presents embodiments of the heat exchanger. Inside the section of the pipeline 3 are plates of magnetic materials 4.

On figa) shows the installation of induction heating of the pipeline, which, in order to increase power and heating area, as well as increase the controllability of the heat transfer process, contains several independent heat exchangers 3 connected in series, and for each heat exchanger there are independent from each other conversion and control devices 1 and induction wires 2. Heat exchangers can be connected in parallel (figb)).

The installation works as follows (figure 1). From the conversion and control system with an autonomous current inverter 1, an alternating sinusoidal voltage is supplied to the coil of the induction wire 2, which forms a heating circuit of complex geometry. Under the influence of eddy currents arising in the metal heat exchanger 3, heating occurs in the body of the pipeline and magnetic plates inside the pipeline and heat is transferred from the walls of the pipe and plates to the heated fluid. Due to the plates inside the pipe, the fluid flow is divided into several streams and mixing occurs in such a way that the heated fluid at the walls of the pipe and plates, mixing, penetrates the flow, increasing the heat transfer rate. The area of temperature exposure depends on the area of the coil of the induction wire, the number of turns, the diameter of the pipeline and the area of the plates (figure 1).

In case of exceeding the specified parameters of the temperature of the heated fluid, the power automatically decreases or the control system 1 switches off the induction wire 2.

Information sources

1.http: //www.ijsgroup.ru/equipment/spn.shtm

2. http://www.sieico.ru/geizer/geizer.htm,

3. http://www.termotechnology.ru/index2.php?do=vysokotemperaturnyi-induktivno-konduktivnyi-elektronagrevatel-geizer-v.

Claims (1)

Installation of induction heating of pipelines, consisting of a conversion and control device, a heat exchanger, characterized in that the conversion and control device is based on an autonomous current inverter with quasi-resonant switching, the load of which is an induction wire, which is a multicore copper conductor in heat-resistant insulation, located on the surface the heat exchanger along its entire length in one turn, and the heat exchanger is a system of pipes inside which along the entire length radially arranged plates of magnetic materials.

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