RU2470108C2 - Device for heating of point switch - Google Patents

Abstract

FIELD: construction.

SUBSTANCE: invention is related to railway track facilities, in particular, to maintenance of railway point switches. The device comprises a pulse source of low voltage AC supply and a low-resistance electric heater connected to it. The source of supply has galvanic isolation of a low-voltage supply circuit of the electric heater and a supply linear circuit, and is arranged as capable of controlling duration of supplied pulses. The electric heater is arranged in the form of two parallel tapes covered with a heat resistant insulating layer, a resistive low-resistance one, preferably from stainless steel, and a heat-insulating one. The electric heater is installed in a point groove between blade pads and frame rail journal without thermal contact with it.

EFFECT: simplified design of a device and provision for spend of produced heat practically only for direct convection heating of point groove space, and reduced ohmic resistance of an electric heater and accordingly supply voltage value.

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Description

The invention relates to the field of railway track facilities, in particular to the winter maintenance of railroad switches, and can be used on stages, stations, parks and slides operated in conditions of snowdrifts and icing, to eliminate the effect of snowfall and ice on the smooth operation of the railroad switch.

There are various means of eliminating the influence of snowfall and icing on the turnout:

1) blowing snow with compressed air from the gutter between the frame rail and the wit

- SU 894027, E01B 19/00, E01H 8/10, 1981.12.30; US 4674718, E01B 7/24, 1987-06-23; CA 1292799, E01B 7/24; E01B 7/00, 1991-12-03;

2) heating of the rail base

- a heater with a coolant - hot water - EP 0247693, E01B 7/24, 1987.12.02; RU 2011725 C1, E01B 19/00, 1994.04.30; JP 7102501, E01B 7/24, 1995-04-18;

- resistive heater - SU 1657563 A1, E01B 7/24, 1991.06.23; RU 2002130291 A, E01B 19/00, E01B 7/24, 2004.05.10;

3) direct heating railroad switches

- hot air - GB 837748, E01B 7/24, 1960-06-15; GB 898091, E01B 7/24, 1962-06-06; GB 1066433, E01B 7/24, 1967-04-26; W02005045134, E01B 7/24, 2005-05-19;

- gas burners - GB 968885, E01B 7/24, 1964-09-02; GB 1317496, E01B 7/24, 1973-05-16; GB 1499109, E01B 7/24, 1978-01-25; GB 2039023, E01B 7/24, 1980-07-30;

4) rail heating

- a heater with a coolant - hot water - GB 557993, E01B 7/24, 1943.12.14; RU 837988, E01B 7/24, 1981/06/15;

- condensation of steam in the heater - FR 2538088, B61D 27/00, E01B 7/24, 1984-06-22; RU 2003755 C1, E01B 19/00, E01B 7/24, 1993.11.30;

5) electrical heating of the railroad switches

- direct induction heating of rails - GB 669976, E01B 7/24, 1952-04-09; GB 2272929, E01B 7/24, E01B 19/00, 1994-06-01; SU 1788117 A1, E01B 7/24, 1993.01.15; JP 10266101, E01B 7/24, 1998-10-06;

- induction heating of the plate under the frame rail and wit slip cushion - JP 2001115403, E01H 8/08, E01B 7/24, 2001-04-24;

- heating by a resistive heater - GB 771722, E01B 7/24, 1957-04-03; SU 1096321 A, E01B 7/24, 1984.06.07; SU 1557232 A1, E01B 7/24, 1990.04.15; JP 5148801, E01B 7/24; E01H 8/08, 1993-06-15; RU 2010072 C1, E01B 7/24, E01B 19/00, 1994.03.30; RU 2010073 C1, E01B 7/24, E01B 19/00, 1994.03.30.

Known means used for heating turnouts provide a complex structural embodiment and require the operation of large energy costs, including inappropriate ones due to large heat losses spent on heating the space outside the turnout switch.

Analogues of the claimed technical solution are devices that use resistive electric heaters to heat the switch.

Known electric heater for railroad switches (GB 771722, E01B 7/24, 1957-04-03), which is attached to the bottom of the frame rail on the opposite side of the wit in the areas between the sleepers and has thermal contact with the bottom of the rail and its neck on local plots. To heat the entire turnout switch, it is necessary to install a large number of such electric heaters on frame rails.

The known device provides a complex structural embodiment and requires the operation of large energy costs, including inappropriate due to large heat loss.

A railroad rail heater is also known (SU 1096321 A, E01B 7/24, 1984.06.07), comprising a tubular heater casing comparable in length to the frame rail with two electric spirals placed inside the casing connected to a power source.

Opposite ends of the heater casing are attached to the frame rail with the possibility of moving the casing in the horizontal plane using the drive. The drive of the heater body is made in the form of sequentially arranged heat-conducting plates, increasing in length to the end of the wit. At one end, each plate is connected to the housing, and at the other, it is attached to the wit in such a way that when the wit is closed with the frame rail, the heater body moves relative to the frame rail towards the base of the wit, and when opened - in the opposite direction.

When the spirals are turned on, heat from the electric heater body is transferred to the frame rail, and through the plates to the wit and the space of the arrow trough, thereby cleaning it.

The known device provides a complex structural embodiment, significant difficulties during installation and operation, low reliability.

A device for heating the turnout switch (SU 1557232 A1, E01B 7/24, 1990.04.15) is provided, comprising a housing mounted on a rail under the sole of the frame rail, inside of which an electric heater is placed in the form of an elastic tape with a resistive element connected to a power source. To heat the entire turnout switch, the known devices must be installed under the frame rails on all sleepers of the turnout switch, providing for the corresponding seats in the sleepers.

The known device provides a complex implementation and requires the operation of large energy costs, including inappropriate due to large heat losses.

A device is known for melting snow at a railroad switch (JP 5148801, E01B 7/24; E01H 8/08, 1993-06-15), including a power source and an electric heater connected to it, connected to a plate radiator, which is mounted on the end of the sleepers under local section of the rail. To heat the entire turnout switch, electric heaters with plate radiators must be installed on all sleepers of the turnout switch.

The known device provides a complex structural embodiment and requires the operation of large energy costs, including inappropriate due to large heat loss.

A heater for the arrow is also known (RU 2010072 C1, E01B 7/24, E01B 19/00, 1994.03.30), comprising a sheet steel body covering both the neck and the bottom of the rail in its local area. The case houses thin metal boxes with a heating resistive element. The external walls of the heater are insulated by a thermal screen, which allows to reduce losses only on the external radiation of the heater itself. To heat the entire turnout switch, it is necessary to install a large number of such electric heaters on it.

The known device provides a complex structural embodiment and requires the operation of large energy costs, including inappropriate due to large heat loss.

A device for heating the arrow (RU 2010073 C1, E01B 7/24, E01B 19/00, 1994.03.30) is known, which comprises a cast aluminum casing fixed to the rail on its local section on the opposite side of the wit, made in the form corresponding to the contour of the rail neck . The housing contains heating resistive elements. The outer wall of the heater is insulated with a thermal inversion screen, which allows to reduce losses only on the external radiation of the heater itself. To heat the entire turnout switch, it is necessary to install a large number of well-known electric heaters on it.

The known device provides a complex structural embodiment and requires the operation of large energy costs, including inappropriate due to large heat loss.

There is also a device for heating turnouts used in railway transport (Automatic electrical heating of turnouts SK-TTS, Russian Railways, St. Petersburg, 2006). This device on the set of essential features is the closest analogues of the claimed technical solution.

The known device includes an adjustable power supply duration and a long high-resistance electric heater connected to it — a heating element. The heater is made in the form of an extended loop of a high-impedance conductor enclosed in a steel case, which is filled with a refractory insulating material - sand.

The heater is attached with thermal contact to the frame rail on the opposite side of the wit. If necessary, to clear the turnout of snow and ice, the power source is turned on and a current of 220 V 50 Hz is supplied to the heating element, the duration of which is determined by the measured temperature of the heated rail.

The reasons that impede the achievement of the technical result indicated below when using the known device include the comparative complexity of the design of the heating element, its high voltage, limited service life, high energy consumption, including inappropriate ones due to large heat losses for heating the space outside the switch.

The task to which the invention is directed is to simplify the design of the device, increase the reliability and ease of use, reduce energy consumption, increase the service life and improve safety.

The technical result obtained by carrying out the invention is to significantly simplify the design of the device, to ensure that the generated heat is used only for direct convection heating of the arrow groove space, and also to reduce the ohmic resistance of the electric heater and the corresponding value of the supply voltage.

The specified technical result during the implementation of the invention is achieved by the fact that in the inventive device for heating the switch, containing an adjustable AC power source and connected to a source, comparable in length with a frame rail and a resistive electric heater attached to it, in contrast to the known device, the electric heater is made in in the form of two parallel tapes covered by a heat-resistant insulating layer - resistive low-resistance and heat-insulating, while the electric heater is installed It was mounted on the upper platform of the frame rail sole on the wit side between its sliding cushions and the frame rail neck without thermal contact with it, and the power supply was pulsed with galvanic isolation of its low-voltage power supply circuit of the electric heater from the supply line network and with the possibility of controlling the duration of the supplied pulses.

Resistive tape heater is preferably made of stainless steel.

Figure 1 shows a cross section of an electric heater of the claimed device; figure 2 - symbol of the cross section of the turnout; figure 3 is a schematic diagram of a power source; figure 4 is a photograph of the switch with an installed electric heater; figure 5 is a photograph of the wit and frame rail with an electric heater attached to it.

The electric heater 1 (Fig. 1) of the inventive device for heating the switch contains two parallel tapes: one - 2 - low resistance, and the other - 3 - thermal insulation. Both tapes 2 and 3 are placed in a heat-resistant insulating layer 4. The electric heater 1 (Fig. 2), comparable in length to the frame rail 5, is installed with a non-heat-conducting side using staples (not shown in Fig.) In the arrow groove 6 on the upper platform 7 of the sole frame rail 5 from the side of the pin 8 between the cushions 9 of the pin 8 and the neck 10 of the frame rail 5. The ends of the resistive tape 2 of the electric heater 1 are connected to a power source 11.

In figure 2, under the position numbers N ₁ and N _2, the elements of the left and right sections of the turnout are indicated.

The power source 11 (figure 3) contains a power transformer 12, the primary winding of which 13 is connected to a linear AC network through a chopper - a simistor 14 with its control circuit 15 and a start circuit 16. The electric heater 1 is connected to the secondary winding 17 of the power transformer 12. Scheme control 15 is connected to the sensor 18 of the outdoor temperature.

The inventive device for heating the switch works as follows.

If necessary, to clear the turnout of snow and ice, the connection of the power source 11 to the linear network can be carried out both from the control panel (not shown in Fig.), And automatically by the signal from the temperature sensor 18 when the set outdoor temperature values are reached.

The simistor 14, controlled by the circuit 15 and the start circuit 16, sends alternating current pulses of a given duration to the primary winding 13 of the power transformer 12. The secondary winding 17 of the transformer 12 lowers the output voltage of the alternating current pulses supplied to the low-resistance electric heater 1, and, at the same time, provides galvanic isolation electric heater 1 from the power line network.

When current pulses flow with a given number of alternating current periods in each pulse, a surface effect is manifested in the heating element — resistive tape 2 of electric heater 1. It consists in the uneven distribution over the cross section of the conductor of the current density, which exponentially decreases towards the axis of the conductor. The maximum current density will be on the surface, and in a layer whose thickness is equivalent to the depth of current penetration, about 90% of the total amount of heat will be released.

Since the electric heater 1 is installed in the arrow groove 6 on the upper platform 7 of the sole of the frame rail 5 without thermal contact with it, the heat radiated by the electric heater 1 is almost completely used for convection heating of the space of the arrow groove 6 and the snow-ice formations located in it.

Depending on the temperature of the outside air, the amount of snow and / or ice located on the turnout switch, the intensity of heat generation by the electric heater 1 can be controlled by increasing or decreasing the duration of the current pulses set by the controlled triac 14.

The design of the electric heater 1 in the form of two strips - resistive 2, preferably stainless steel, and heat-insulating 3, for example, from paronite placed in a tube made of heat-shrinkable material, is much simpler and cheaper than the well-known electric heaters TEN, currently used in turnout heaters SK -TTS of JSC Russian Railways.

In addition, the use of a stainless steel tape with a lower ohmic resistance in the heater as a conductive element increases its service life, reduces the supply voltage, provides galvanic isolation from the power line network, improves safety, reliability and ease of use, including when repair arrows, reduce energy consumption and increase service life.

Conducted experimental field tests of the proposed technical solution (Fig.4 and 5) showed its effectiveness.

A tape made of stainless steel 1X18H10T with a cross section of 2 × 10 mm, a supply voltage of 24 V with an industrial frequency of 50 Hz, and a pulse current of up to 130 A were taken as an electrically conductive tape. Paronite tape was used as a thermal insulator. Symmistor - ТС 122, control circuit and start-up of the symmistor - PIC18F20 controller, temperature sensor - AD22100.

Thus, it is seen that the above information confirms the possibility of implementing the claimed invention, achieving the specified technical result and solving the problem.

Claims (2)

1. A device for heating the turnout switch, containing an adjustable AC power source and connected to a source comparable in length to the frame rail and attached to it a resistive electric heater, characterized in that the electric heater is made in the form of two parallel tapes covered by a heat-resistant insulating layer - resistive low resistance and heat-insulating, while the electric heater is installed on the upper platform of the sole of the frame rail from the side of the wit between its cushions and a frame rail without thermal contact with it, and the power supply is made pulsed with galvanic isolation of its low-voltage power supply circuit of the electric heater from the supply line network and with the possibility of controlling the duration of the supplied pulses. 2. The device according to claim 1, characterized in that the resistive tape of the electric heater is made of stainless steel.

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