RU2415988C2 - Method to clean slip switch of snow and ice by electrical heating - Google Patents

Abstract

FIELD: transport.

SUBSTANCE: proposed device comprises tubular electric heaters and temperature pickups mounted on frame rails, power supply for said electric heaters from AC circuit with single-phase transformer and automatic controller. Said controller comprises switch connected in power supply circuit of single-phase isolation transformer. Switch control input incorporates relay element with hysteresis characteristic and input connected with comparator output. Comparator first input is connected with frame rail temperature pickup. Besides, there are additional ambient air temperature pickup and nonlinear operating converter, connected in series and to comparator second input.

EFFECT: efficient snow and ice melting, reduced power consumption.

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Description

The invention relates to railway transport, and more specifically to ensuring the normal operation of turnouts in the conditions of snow drifts.

Known devices for the electrical heating of turnouts using tubular oval-shaped heaters that are mounted on frame rails and connected to the mains via an isolation transformer and switch [1, 2].

The disadvantage of these devices is that they are not regulated as a function of air temperature, which reduces their efficiency and leads to significant energy consumption.

This drawback is partially eliminated in the device for cleaning the turnout from snow and ice by electric heating, which contains tubular electric heaters and temperature sensors mounted on frame rails, the power supply unit of these electric heaters from an alternating current main with a single-phase transformer and an automatic regulator, the latter included a switch included in the power supply circuit of a single-phase transformer, and a relay element with a hist rezisnoy characteristic to its input connected to the output element of comparison, the first input of which is connected to the frame rails of temperature sensors [3, 4]. This device can be taken as a prototype.

The disadvantage of the prototype is that the temperature of the frame rails is maintained constant regardless of the outside temperature. At the same time, for effective snow melting, it is necessary to keep the frame rail at a temperature of 40-50 ° C during severe frosts, and in light frosts it is quite possible to reduce it to 20-25 ° C. This will save energy without affecting snow melting.

The technical result of the invention is the provision of increasing the efficiency of snow melting while reducing energy consumption.

The technical result in this invention is achieved due to the fact that there is additionally provided an outdoor temperature sensor and a non-linear functional converter connected in series and connected to the second input of the comparison element.

The invention is illustrated by a specific example of execution in the drawing. Shown here are the frame rails 1-2, which are part of the turnout. They are installed tightly adjacent to them tubular electric heaters (TEN) 3-6 and heating temperature sensors 7-10 of these rails. The mounting and fastening scheme of elements 3-10 on the frame rails is typical and corresponds to TU-TsP-88.

Electric heaters 3-6 by means of electric wires 11 (two-core cables laid in the subgrade) are connected to the secondary winding of an isolation transformer 12, the primary winding of which is connected to the wires of a standard three-phase network 13, and in this example, specifically to phase C and neutral wire N. The connection to phase C is made by means of a contactor K 14, which is part of the controller considered below and performs the functions of a power actuator.

In addition to K 14, the controller includes a relay element 15, a comparison element 16, a piecewise linear functional converter 17. An external air temperature sensor ДТНВ 18 is connected to the input of the latter. Elements 14-18 are connected in series, and the outputs of the sensors 7 are connected to the second input of the ES 16 -10 through a typical logic element 19.

The switch 14 can be made as a single-pole AC contactor or as a contactless key, for example on antiparallel connected thyristors.

The blocks 15-19 of the controller are made according to standard schemes on operational DC amplifiers and diode assemblies [5].

The drawing does not show the typical components used in all electrical systems of alternating current with a power of 8-32 kW, namely protective devices, blocks for monitoring the insulation resistance and detecting an open circuit in each of the electric heaters, an alarm panel and a general electric heating switch.

The device according to this invention works as follows.

In winter, electric heaters 3-6 receive power through wires 11 from the transformer 12 and heat the frame rails 1-2, providing snow melt in the working intervals of the railroad switch, i.e. from the tip of the pen to the root of the wit. In this case, the heating temperature of the frame rails 1-2 is automatically and continuously regulated as a function of the outdoor temperature θ _nv . The latter is continuously measured by the sensor 18 and its output signal is fed to the input of the transducer 17, which sets the temperature θ _{c of} heating the frame rails 1-2 in terms of θ _nv . An approximate form of the corresponding curve is presented on the characteristic θ _s (θ _nv ) of the converter 17. The essence of this characteristic is to provide a more intense heating of the frame rails 1-2 at a lower air temperature, since this increases the heat loss to the environment. For example, the characteristic of element 17 in the drawing shows that at θ _HB = -40 ° C, it is necessary to heat the frame rails 1-2 to θ _s = + 55 ° C.

This temperature value in the form of an electrical signal is fed to the input of the comparison element 16, which calculates the mismatch

Δθ = θ _s -θ _f .

According to this signal, the relay switch 15 operates. At Δθ> 3 ° C it turns on the switch 14 and, accordingly, heaters 3-6, and at Δθ <-3 ° C it turns them off. Thus, the set heating temperature of the frame rails is maintained with an error of not more than ± 3 ° C.

The effectiveness of this invention is determined by adaptability to changes in outdoor temperature and average seasonally energy savings of 25-35%.

Information sources

1. Instructions on the procedure for preparing for work in the winter and organizing snowfights on the railways of Russian Railways. Appendix 8. Stationary devices for cleaning arrows from snow, p.147-148, NKI Akademkniga, 2006

2. Technical instructions for the maintenance of electrical heating devices for cleaning turnouts of snow. Ministry of Railways of the USSR, 1990 (fully accepted by Russian Railways).

3. Guidelines for the management of switchgear. Published in the journal “Way and track facilities”, 2006, pp. 23-28, sections 15.4, 15.15 (official document of Russian Railways).

4. The advanced electric heating system of switches SEIT-04. Technical design and user manual. Roszheldorproject OJSC, 2006

5. Nefedov A.V. Integrated circuits and their foreign counterparts. Volume 1. M., ed. CUBE, 1997

Claims (1)

A device for cleaning the switchgear of snow and ice by electric heating, comprising tubular electric heaters and temperature sensors mounted on frame rails, a power supply unit of said electric heaters from an alternating current main with a single-phase transformer and an automatic regulator, the latter comprising a switch included in the power circuit a single-phase transformer, and at the control input of the specified switch a relay element with a hysteresis characteristic is installed, to its input under comparison element for prison output, the first input of which is connected with temperature sensors stock rails, characterized in that the additionally provided outside air temperature sensor and the nonlinear function generator connected in series and connected to the second input of the comparison element.