DE102018007263A1 - Method and device for controlling and regulating a point heater - Google Patents

Abstract

The present invention relates to a method and a device for controlling and regulating a point heater (1), the point heater (1) comprising at least one heating device (14) arranged on at least one point (3), at least one point temperature sensor (28) on the at least one Switch (3), at least one energy distribution with at least one heating outlet per switch (3) and at least one control device for controlling and regulating the switch temperature. In particular, a heating network (26, 27) is formed for the at least one turnout segment for the left side (5) of the at least one turnout (3) and / or for the right side (6) of the at least one turnout (3), the Has heat network (26, 27) heat generating elements, heat transfer elements and heat storage (32), and assigning the at least first node (K) of the respective sections of the at least one switch segment to at least one evaluation point (37, 38, 39, 40, 41, 42, 43).

Description

The present invention relates to a method and a device for controlling and regulating a point heater, in particular depending on the weather, rail profile and position of the movable tongue rail by calculating and evaluating the real point temperatures at functionally relevant points of the point in winter on at least one point segment between the point tips and point end.

Track elements, especially switches, of rail-bound vehicles such as railways (full railways, branch lines, narrow-gauge railways) or trams are heated as required with point heaters in order to prevent freezing of the moving parts or their blocking by snow and ice, and thus operational safety, especially in winter to ensure. Known point heaters are based on systems with hot water steam, gas heating or electrical energy.

In winter, point heaters are used to melt snow between the rails of the points and to prevent the movable tongue rail from freezing to the fixed stock rail and the sliding chair plates, as well as the compression of snow between the rails. For this purpose, heating devices with a specific output of, for example, 330 W per meter of rail are arranged on the fixed stock rails of the turnout, and if the weather permits, the heating is activated by a weather station and thus the stock rail at the location of the turnout temperature sensor except for a setpoint temperature in two-point control warmed with hysteresis.

Such point heaters are conventionally controlled by means of a point temperature sensor on a central point, which is arranged on the lower surface of the stock rail base due to the function of the point. The disadvantage here is that during operation, only at the location of the turnout temperature sensor, the turnout temperature corresponds to the desired turnout temperature and the other parts of the turnout, depending on the weather and on the position of the tongue rail, which can be adjacent or detached from the backrest rail, can cause both temperature deficits and excess temperatures. which either lead to freezing and thus failure of the switch or to high (unnecessary) energy consumption.

The conventional point heaters are currently switched on when heating is requested with 100% specific output and switched off and on again after reaching the set point temperature until a hysteresis of the real point temperature is reached. The result in heating mode are power peaks between zero and maximum value and significant temperature differences of the stock rails, tongue rails and sliding chair plates on the right and left side as well as over the length of the switch. A reliable function of the turnouts in winter, especially in extreme weather conditions, in wind, low ambient temperature and heavy snowfall in automatic operation is not possible with the state of the art.

Heating devices according to the prior art are arranged, for example, on the fixed stock rails of the left and right sides of the switch on the rail foot and are designed with a specific power of typically 330 W per meter over the entire length of the switch. The heat transfer to the tongue rails and sliding chair plates of the switch takes place by means of heat conduction or heat radiation from the location of the stock rails provided with a heating device. In operation, the switch is used on the stock rails and the tongue rails on the left and right sides depending on the ambient conditions and the switch position, i.e. remote or adjacent tongue rail, as well as different real switch temperatures at the sliding chair plates. At low ambient temperatures, betting extremes and / or wind, there are considerable heating deficits so that, despite heating, functionally relevant points of the switch do not reach zero degrees or positive switch temperatures and the snow is not melted at these points. In this case, when the switch is set, the snow between the rails, i.e. between the tongue rail and stock rail, pressed and the tongue rail can no longer reach the end position when freezing or freezes and the switch can no longer be changed.

Utilizing the analogy between an electrical flow field and a thermal flow field (cf. Tab. 1), heat generation processes, heat transfer processes and heat storage processes can be calculated using networks that are well known in electrical engineering. The non-linear processes occurring in heating networks require a computer-aided iterative solution process ^[1] . Table 1: Analogy between thermal and electrical flow fields size electric thermal impulsive Voltage difference Δφ Temperature difference Δϑ fluently Current I Power P resistance R = Δφ / I R _th = Δϑ / P capacity c = dQ / Δφ C _th = dW / dϑ

Heat sources, thermal resistances, thermal capacities and fixed temperatures occur in a heating network. They represent heat generation, heat transport, heat storage and the thermal boundary conditions. The services generated in the conductors and the encapsulation P are transmitted to the environment by radiation and convection and by heat conduction along the conductor track or the capsule. Depending on the thermal resistance R _th and the power P there is an overtemperature Δϑ.

Heat transfer

In electrical engineering systems, the power is transmitted through radiation, heat conduction and convection.

Radiation ^[2]

wobei sich die resultierende Emissionszahl ε₁₂ für sich umhüllende Körper (2 umhüllt 1) aus geometrischen Betrachtungen zu $${\epsilon }_{12}=\frac{1}{\frac{1}{{\epsilon }_1}+\frac{O_1}{O_2}\left(\frac{1}{{\epsilon }_2}\right)-1}$$

ergibt.The between two bodies 1 and 2nd Exchanged radiation power is calculated using the Stefan-Boltzmann law with Os as the surface of the radiating body and C _S = 5.67 W / m ² K ⁴ as the radiation coefficient of the black body. $$P_s={\mathrm{C.}}_s{\epsilon }_{\mathrm{12th}}{O}_s\left(\frac{{\mathrm{<figure-callout\; id="1"\; label="T"\; filenames="DE102018007263A1\_0030.png,DE102018007263A1\_0031.png"\; state="\{\{state\}\}">T</figure-callout>}}_1^{\mathrm{4th}}}{100}-\frac{T_{\mathrm{2nd}}^{\mathrm{4th}}}{100}\right)$$

the resulting emission number ε ₁₂ for enveloping bodies ( 2nd envelops 1 ) from geometric considerations $${\epsilon }_{\mathrm{12th}}=\frac{1}{\frac{1}{{\mathrm{<figure-callout\; id="1"\; label="\epsilon "\; filenames="DE102018007263A1\_0030.png,DE102018007263A1\_0031.png"\; state="\{\{state\}\}">\epsilon </figure-callout>}}_1}+\frac{O_1}{O_{\mathrm{2nd}}}\left(\frac{1}{{\epsilon }_{\mathrm{2nd}}}\right)-1}$$

results.

Heat conduction ^[2]

According to Fourier's law of heat conduction, the transported heat output is in the stationary state P _L linearly variable with the spatial change in temperature if there is no additional heat source. The proportionality factor is called thermal conductivity λ designated. The section length L and the cross-sectional area A influence the transported heat output significantly. In the homogeneous one-dimensional heat flow field, the heat output by conduction can be simplified as follows. $$P_L=\frac{\lambda A\Delta \vartheta }{L}$$

Convection ^{[3], [4], [5]}

The thermal energy by convection is calculated via the relationships between the material properties of the cooling medium, the flow and the heat transfer to other media, arrangements and temperature ranges. To do this, there are dimensionless similarity numbers Reynolds number (abstracted from forced convection) Grashof number (abstracted from free convection) Nusselt number (abstracted from heat transfer) Prandtl number (abstracted from the flow medium) with v as flow velocity, v as viscosity, β as a volume expansion coefficient, G as gravitational acceleration, c _p as specific capacity and δ formed as a density.

The relationship between the convective heat transfer coefficient K and the flow rate v is produced using the Nusselt, Prandtl and Reynolds numbers: $${\alpha }_{\text{K}}=\text{f}\left(\text{Nu}\right)=\text{f}\left(\text{re},\text{Size},\text{Pr}\right)$$

wird die durch Konvektion übertragbare Leistung berechnet.With Newton's heat transfer law $$P_K={\alpha }_K{O}_K{\Delta }_{\vartheta }$$

the power that can be transmitted by convection is calculated.

The process can be calculated iteratively depending on the temperature in the heating network.

Heat outputs

The ohmic resistance heats up all current-carrying sections. Current heat losses occur due to the operating current and capsule losses due to induction in the capsule (hysteresis, induction and eddy current losses).

Electricity heat losses

und $$R_{Lei}=\text{k}\frac{p1}{A}\left(1+{\alpha }_T\Delta \vartheta \right)$$

berechnet werden. Der Widerstand R_lsi ist sowohl von der Querschnittsfläche A als auch von dem spezifischen Widerstand des Leiters p, der Abschnittslänge I, der Stromart (Stromverdrängungsfaktor k) ^[5] und der Leiterübertemperatur Δϑ^[6]) abhängig.Become resources from electricity I1 flows through, caused by the material properties of the conductor, a resistance to the current flow. The implemented performance can with $$P_{Lei}={\mathrm{I.}}_{\mathrm{I.}}^{\mathrm{2nd}}{R}_{Lei}$$

and $$R_{Lei}=\text{k}\frac{p1}{A}\left(1+{\alpha }_T\Delta \vartheta \right)$$

be calculated. The resistance R _lsi is both of the cross-sectional area A as well as the specific resistance of the conductor p, the section length I. , the type of current (current displacement factor k ) ^[5] and the excess conductor temperature Δϑ ^[6] ).

Heat capacity

ein. Durch Ableitung ist diese auf die Leistung umstellbar.The heat capacity of a conductor section goes into the calorimetric equation $$Q_c=\text{C.}\Delta \vartheta$$

on. By derivation, this can be converted to performance.

mit dem Volumen V, der Dichte δ und der spezifischen Wärmekapazität C.The heat capacity C. results from $$\text{C.}=\text{cm}=\text{c}\delta \text{V}$$

with the volume V , the density δ and the specific heat capacity C. .

The methods and devices known from the prior art consequently sometimes have a very high technical outlay for installation and maintenance with, at the same time, uneven and / or inadequate heating of essential functional parts of guideway elements. There is therefore a need to eliminate the disadvantages of the prior art without further increasing the technical outlay.

The present invention is therefore based on the object of specifying a method for controlling and regulating a point heater and of providing a corresponding device which overcomes the disadvantages of the prior art and with which an additional outlay for sensors is avoided and the associated outlay on maintenance is reduced.

The invention is described in detail below. If objective features are mentioned in the description of the method according to the invention, these relate in particular to the device according to the invention. Method features that are mentioned in the description of the device according to the invention likewise relate to the method according to the invention.

1. a) Definieren zumindest eines Weichensegments für die linke Seite (5) der zumindest einen Weiche (3) und/oder für die rechte Seite (6) der zumindest einen Weiche (3) mit einer spezifischen Länge, wobei das Weichensegment der zumindest einen Weiche (3) eine Backenschiene (7), eine Zungenschiene (8), eine Gleitstuhlplatte (9) und zumindest eine Heizeinrichtung (14) aufweist, und Zerlegen des zumindest einen Weichensegments in einzelne Abschnitte mit jeweils zumindest einem ersten Knoten, der zumindest einer funktionsrelevanten Stelle (19) des Weichensegmentes der zumindest einen Weiche (3) im Winter entspricht, wobei die funktionsrelevante Stelle (19) mindestens einen Bewertungspunkt (37, 38, 39, 40, 41, 42, 43) aufweist, wobei das zumindest eine Weichensegment repräsentativ die zumindest eine Weiche (3) thermodynamisch abbildet, wobei das zumindest eine Weichensegment in der Nähe des zumindest einen Weichentemperatursensors (15, 18) angeordnet ist,
2. b) Bilden eines Wärmenetzes (26, 27) für das zumindest eine Weichensegment für die linke Seite (5) der zumindest einen Weiche (3) und/oder für die rechte Seite (6) der zumindest einen Weiche (3), wobei das Wärmenetz (26, 27) Wärmeerzeugungselemente, Wärmeübertragungselemente und Wärmespeicher (32) aufweist, und Zuordnen des jeweils zumindest ersten Knoten (K) der jeweiligen Abschnitte des zumindest einen Weichensegments zu mindestens einem Bewertungspunkt (37, 38, 39, 40, 41, 42, 43), wobei alle Knoten (K) der einzelnen Abschnitte über Maschen zu dem Wärmenetz (26, 27) so verbunden werden, dass die Differenz aller vorzeichenbehafteten Temperaturen gleich Null ist,
3. c) Berechnen des zeitlichen Verlaufs einer optimalen spezifischen Leistung (P_op ) des zumindest einen Weichensegments und der jeweiligen optimalen Weichentemperatur an dem zumindest einen ersten Knoten der Weichenheizung (1) an dem zumindest einen Weichensegment über eine Leistungsbilanz gemäß eines Knotensatzes, und bei Betrieb Aktivieren dieser optimalen spezifischen Leistung an der zugehörigen Heizeinrichtung (14) mittels Produkt aus realer spezifischer Leistung der Heizeinrichtung (14), die der maximalen spezifischen Leistung entspricht, und einem Leistungsverhältnis, wobei das Leistungsverhältnis variabel zwischen 25 % und 100 % der realen spezifischen Leistung entspricht,
4. d) Erfassen des zeitlichen Verlaufs der realen Weichentemperatur an dem zumindest einen Weichensegment mit dem zumindest einen Weichentemperatursensor (28) und Korrigieren der berechneten Weichentemperatur an einem der zumindest ersten Knoten des zumindest einen Weichensegments über Leistung Konvektionswärme wenn berechnete Weichentemperatur größer ist als reale Weichentemperatur oder Leistung Strahlungswärme des Wärmenetzes wenn berechnete Weichentemperatur kleiner ist als reale Weichentemperatur,
5. e) Berechnen der Weichenendtemperatur an zumindest einem zweiten Knoten des zumindest einen Weichensegments und Vergleichen der berechneten Weichenendtemperatur mit einer parametrierten Weichenmindesttemperatur für diesen zumindest einen zweiten Knoten, wobei bei Nichterreichen der Weichenmindesttemperatur der Weiche (3) eine parametrierbare Weichensolltemperatur um einen Weichensolltemperatur-Korrekturfaktor so lange erhöht wird, bis die jeweilige berechneten Weichenendtemperatur der Weiche (3) zumindest der Weichenmindesttemperatur der Weiche (3) entspricht,
6. f) Berechnen der Anheizzeit für das Erwärmen des zumindest einen Weichensegments bis zu der parametrierbaren Weichensolltemperatur der Weiche (3) und Bewerten der berechneten Anheizzeit bei parametrierbarer Weichensolltemperatur, wobei bei einem Defizit die optimale spezifische Leistung erhöht und bei einem Überschuss die optimale spezifische Leistung verringert wird.,
7. g) Berechnen der Anheizzeit für das Erwärmen des zumindest einen Weichensegments bis zu der parametrierbaren Weichenmindesttemperatur der Weiche (3) und Bewerten der erforderliche spezifische Leistung aus Erhaltungsleistung und Schmelzleistung für den bis dahin gefallenen Schnee mit der spezifischen Leistung (P) bei parametrierbarer Weichenmindesttemperatur, wobei bei einem Defizit die optimale spezifische Leistung erhöht oder eine Meldung „gefallene Schneemenge ist zu groß und wird nicht geschmolzen“ erzeugt wird.

The above object is achieved in a first aspect of the present invention by a method for controlling and regulating a point heater ( 1 ) solved, the point heater ( 1 ) at least one on at least one switch ( 3rd ) arranged heating device ( 14 ), at least one switch temperature sensor ( 28 ) on at least one switch ( 3rd ), at least one energy distribution with at least one heating outlet per switch ( 3rd ) and has at least one control device for controlling and regulating the switch temperature, comprising the steps:

1. a) Define at least one turnout segment for the left side ( 5 ) of at least one switch ( 3rd ) and / or for the right side ( 6 ) of at least one switch ( 3rd ) with a specific length, the switch segment of the at least one switch ( 3rd ) a stock rail ( 7 ), a tongue splint ( 8th ), a sliding chair plate ( 9 ) and at least one heater ( 14 ), and breaking down the at least one turnout segment into individual sections, each with at least one first node, the at least one function-relevant point ( 19th ) of the turnout segment of the at least one turnout ( 3rd ) in winter, with the functionally relevant position ( 19th ) at least one evaluation point ( 37 , 38 , 39 , 40 , 41 , 42 , 43 ), the at least one switch segment representing the at least one switch ( 3rd ) depicts thermodynamically, the at least one switch segment in the vicinity of the at least one switch temperature sensor ( 15 , 18th ) is arranged,
2. b) forming a heating network ( 26 , 27 ) for the at least one turnout segment for the left side ( 5 ) of at least one switch ( 3rd ) and / or for the right side ( 6 ) of at least one switch ( 3rd ), the heating network ( 26 , 27 ) Heat generating elements, heat transfer elements and heat storage ( 32 ) and assigning the at least first node ( K ) of the respective sections of the at least one turnout segment for at least one evaluation point ( 37 , 38 , 39 , 40 , 41 , 42 , 43 ), with all nodes ( K ) of the individual sections via meshes to the heating network ( 26 , 27 ) are connected so that the difference between all signed temperatures is zero,
3. c) calculating the time course of an optimal specific performance ( P _op ) of the at least one turnout segment and the respective optimal turnout temperature at the at least one first node of the turnout heater ( 1 ) on the at least one turnout segment via a power balance according to a set of nodes, and during operation activating this optimal specific power on the associated heating device ( 14 ) by means of a product of the real specific performance of the heating device ( 14 ), which corresponds to the maximum specific power and a power ratio, the power ratio being variable between 25% and 100% of the real specific power,
4. d) detecting the time course of the real switch temperature on the at least one switch segment with the at least one switch temperature sensor ( 28 ) and correcting the calculated switch temperature at one of the at least first nodes of the at least one switch segment via the power of convection heat if the calculated switch temperature is greater than the real switch temperature or the radiant heat output of the heating network if the calculated switch temperature is less than the real switch temperature,
5. e) calculating the turnout temperature at at least one second node of the at least one turnout segment and comparing the calculated turnout temperature with a parameterized minimum turnout temperature for this at least one second node, if the minimum switch temperature of the switch is not reached ( 3rd ) a parameterizable turnout target temperature is increased by a turnout target temperature correction factor until the respective calculated turnout end temperature of the turnout ( 3rd ) at least the minimum switch temperature of the switch ( 3rd ) corresponds to
6. f) calculating the heating-up time for heating the at least one turnout segment up to the parameterizable turnout setpoint temperature of the turnout ( 3rd ) and evaluation of the calculated heating-up time with parameterizable set point temperature, whereby the optimal specific power is increased in the case of a deficit and the optimal specific power is reduced in the case of a surplus.,
7. g) calculating the heating-up time for heating the at least one switch segment up to the parameterizable minimum switch temperature of the switch ( 3rd ) and evaluating the required specific performance from maintenance performance and melting performance for the snow that has been fallen up to that point with the specific performance ( P ) with configurable minimum switch temperature, whereby in the event of a deficit the optimal specific output increases or a message "fallen amount of snow is too large and will not melt" is generated.

With the method according to the invention, it is possible to use a point heater ( 1 ) depending on existing or specified project-specific parameters or weather conditions by means of the heat network model according to the invention for one turnout segment for the left side ( 5 ) a turnout ( 3rd ) and / or for the right side ( 6 ) a turnout ( 3rd ), in particular for adjacent ( _on ) and remote ( _ab ) tongue rails ( 8th ), in the areas of the turnout tip ( 16 ), the middle of the switch ( 17th ) and the turnout end ( 18th ) to heat. All specific power losses on the turnout segments can be determined with the appropriate parameters and the optimal turnout temperatures ( T _op ) at nodes ( K ), each with a functionally relevant position ( 19th ) of the turnout segment in winter.

The method according to the invention is basically designed to use the heat network model according to the invention alone with a switch segment for the left side ( 5 ) a turnout ( 3rd ) or for the right side ( 6 ) a turnout ( 3rd ) to create. In this case one of the two sides ( 5 , 6 ) the switch ( 3rd ) and assuming that the selected page ( 5 , 6 ) the switch ( 3rd ) by the more positive of the two sides with regard to the heating process ( 5 , 6 ) the switch ( 3rd ) acts. A necessary reserve is thus included.

However, it is particularly preferred if the heat network model according to the invention each has a switch segment for the left side ( 5 ) a turnout ( 3rd ) and for the right side ( 6 ) a turnout ( 3rd ) is created, since this enables the potential of the present invention to be exploited even better. In the following, the particularly preferred variant is assumed, without excluding the possibility of viewing a turnout segment for only one side.

In addition, when operating the point heater ( 1 ) required performance of the individual heating devices ( 29 ) calculated via the specific power of the length of a turnout segment, by evaluating the turnout temperature of the turnout ( 3rd ) on each turnout segment on the left side ( 5 ) and the right side ( 6 ) determines the position of the switch, i.e. the tongue rail adjacent or lying, and the performance of the heating device ( 29 ) for the left side ( 5 ) and the right side ( 6 ) are adjusted so that the functionally relevant positions ( 19th ) the switch ( 3rd ) have the same switch temperatures over their entire length and thus with the same maximum power of the heating device ( 29 ) compared to the prior art, higher availability in winter over the entire operating temperature range in the automatic operation of the point heater ( 1 ) is reached.

It is essential to the invention that the entire switch ( 3rd ) is representatively represented by at least one turnout segment, which both the left side ( 5 ) the switch ( 3rd ) as well as the right side ( 6 ) the switch ( 3rd ). In this way, the heating network according to the invention ( 26 , 27 ) over a representative cross section of the switch ( 3rd ) with which the heating of the entire turnout ( 3rd ) is carried out as evenly as possible and not just individual areas or one side of a switch as in the prior art.

In cold winters or in extreme weather conditions, the availability of the point heater is increased by the present invention, whereas in mild winters or weather periods without extreme weather conditions, significant energy savings can be realized and power peaks in the network can be avoided.

The method according to the invention is carried out as a function of existing or predefined project-specific parameters or weather conditions, by means of the heat network model according to the invention for a switch segment for adjacent (on) and remote ( _off ) tongue rails ( 8th ) in the areas of turnout tips ( 16 ), Switch center ( 17th ) and point end ( 18th ). All specific power losses on the turnout segment are determined with appropriate parameters and the calculated optimal turnout temperatures ( T _op ) at nodes ( K ), each with a functionally relevant position ( 19th ) in the winter of the turnout segment, calculated.

The heater power required during operation ( 14 ) is about the specific performance ( P ) the length of turnout segments ( I _seg ) calculated and by evaluating the calculated optimal switch temperature ( T _op ) on each turnout segment on the left side ( 5 ) the switch ( 3rd ) and on the right side ( 6 ) the switch ( 3rd ) the position of the switch ( 3rd ), i.e. the position of the tongue rail ( 8th ) adjacent (on) or remote ( _ab ), determined, preferably at the evaluation point head-tongue rail ( 41 ). The performance of the heater ( 14 ) for the left side ( 5 ) the switch ( 3rd ) and the right side ( 6 ) the switch ( 3rd ) is adjusted so that the functionally relevant points ( 19th ) on the turnout segments turnout tip ( 16 ), Switch center ( 17th ) and point end ( 18th ) the left side ( 5 ) and the right side ( 6 ) same real turnout temperatures ( Tw ) which correspond at least to the melting temperature of snow and / or the minimum switch temperature.

Over the entire winter (ie over the main period of use of the point heating ( 1 )) the time that is required during operation to monitor the functionally relevant points ( 19th ) the switch ( 3rd ) of the turnout temperature of the turnout ( 3rd ) "Cold rail ( T _K ) “Until a parameterizable minimum rail temperature is reached ( T _min ) the switch ( 3rd ) to be heated, taking into account the melting capacity ( T _Sm ) of snow and the evaporation capacity of water. Measures are taken if this time is too long or if the amount of snow ( h _p ) is not completely melted.

If, based on weather forecasts, the maximum specific power of the heaters ( 14 ) the minimum rail temperature ( T _min ) the switch ( 3rd ) is not reached or the amount of snow ( h _p ) is not completely melted, the point heater according to the invention ( 1 ) via an additional heating request "preheating" with a second calculated rail target temperature ( T _{target forward} ) the switch ( 3rd ) put into operation so that the conditions are met when the heating request actually occurs. This is done in advance, instead of just reacting to changing weather conditions, as is the case in the prior art.

At the start of operation due to a "preheating" heating request, for example due to snow, a first pair of heating devices ( 14 ), for example the heating devices ( 14 ) on the stock rails ( 7 ) with an optimal specific heating output ( P _op ) activated and when the target rail temperature is reached ( T _target ) the switch ( 3rd ) a second pair of heaters ( 14 ), for example on the tongue rails ( 8th ) or the sliding chair plates ( 9 ) activated. In this way, an increase in the connected load of the point heater according to the invention ( 1 ) compared to the prior art avoided by the first pair of heating device ( 14 ) and the second pair of heating devices ( 14 ) can be activated with a time delay or with proportional specific power by using two-point control during the heating breaks of a pair of heating devices ( 14 ) the other pair of heaters ( 14 ) is activated or group operation or power reduction depending on the type of heating device ( 14 ) takes place.

A turnout segment is placed near a turnout temperature sensor ( 28 ) and the turnout temperatures recorded over time ( T _W ) the switch ( 3rd ) are calculated with calculated optimal switch temperatures ( T _op ) verified. With possible switch temperature differences ( ΔT _W ) the calculated optimal turnout temperatures ( T _op ) the switch ( 3rd ) about convection heat output ( P _K ) or about power radiation ( P _St ) corrected.

The calculation is carried out by means of the heat network model according to the invention for a turnout segment using a microcontroller for a turnout ( 3rd ) or for several turnouts ( 3rd ) a point heater according to the invention ( 1 ), the microcontroller directly next to the switch ( 3rd ) arranged and connected to the control unit in the distribution via communication means. The microcontroller contains switching devices or control devices for switching and controlling the heating devices ( 14 ) depending on the type of heating equipment ( 14 ).

• h) Berechnen der spezifischen Schmelzleistung für die während der Anheizzeit am Weichensegment berechneten Schneemenge aus einer gemeldeten Schneehöhe pro Zeiteinheit und Berechnen der spezifischen Erhaltungsleistung zur Erhaltung der Schmelztemperatur an dem Weichensegment und Vergleich der Summe dieser mit der realen spezifischen Leistung der Heizeinrichtung (14) und, wenn die reale spezifische Leistung der Heizeinrichtung (14) geringer ist, Aktivieren der Weichenheizung (1) mit einer zweiten Weichensolltemperatur, die so groß ist, dass bei Betrieb die spezifische Leistung der Heizeinrichtung (14) zumindest gleich der Summe aus spezifischer Schmelzleistung und Erhaltungsleistung ist.

For the special case that the method does not yet have a heating requirement and a weather warning, the method according to the invention further comprises step

• h) Calculation of the specific melting capacity for the amount of snow calculated during the heating-up period on the switch segment from a reported snow depth per unit of time and calculation of the specific maintenance output for maintaining the melting temperature on the switch segment and comparing the sum of these with the real specific output of the heating device ( 14 ) and if the real specific performance of the heater ( 14 ) is lower, activate the point heater ( 1 ) with a second set point temperature that is so high that the specific output of the heating device ( 14 ) is at least equal to the sum of the specific melting performance and the maintenance performance.

In a development of the method according to the invention, the heat generating elements comprise the specific output of the at least one heating device ( 29 ) with a heat accumulator of the turnout segment and heat transfer by heat radiation. Alternatively or additionally and / or the heat transfer elements comprise thermal resistances on the switch ( 3rd ) from the material properties, the geometric sizes and the prevailing loads due to heat transfer and the environment on the at least one switch segment. This development advantageously results in less effort for the calculation software.

In step f) of the method according to the invention can preferably
the heating-up time for heating the at least one turnout segment is calculated from the sum of individual heating times for the at least one turnout segment for heating it up, for melting snow and for evaporating water on it, and / or
the heating-up time is increased by increasing the power ratio and / or switching from control mode to continuous operation and / or is reduced by reducing the power ratio.

With a long heating-up time, e.g. greater than 20 minutes, the function of the switch ( 3rd ) in winter not only in the 20 minutes, but also endangered because the snow forms a kind of igloo and the point heater ( 1 ) is not able to melt it afterwards.

• i) Berechnen einer Schmelzleistung für gefallenen Schnee in einer parametrierbaren Zeitspanne und Vergleichen dieser Schmelzleistung mit der Differenz aus spezifischer Leistung und einer berechneten Erhaltungsleistung, wobei bei einem Defizit der spezifischen Leistung die Leistung erhöht und/oder ein Dauerheizen begonnen und/oder eine erste Warnmeldung ausgegeben wird, und/oder
• j) Vergleichen der berechneten Anheizzeit mit einer parametrierten maximalen Anheizzeit, wobei bei einem Defizit der spezifischen Leistung die Leistung erhöht und/oder ein Dauerheizen begonnen und/oder eine zweite Warnmeldung ausgegeben wird, und/oder
• k) Berechnen der Schneehöhe aus der Differenz aus gefallener Schneehöhe und geschmolzener Schneehöhe pro Zeiteinheit und Vergleichen der berechneten Schneehöhe mit einer parametrierbaren maximal zulässigen Schneehöhe, wobei bei einem Defizit der spezifischen Leistung die Leistung erhöht und/oder ein Dauerheizen begonnen und/oder eine dritte Warnmeldung ausgegeben wird.

In a preferred embodiment, the method according to the invention further comprises the steps when the heating is active

• i) Calculating a melting capacity for fallen snow in a parameterizable period of time and comparing this melting capacity with the difference between the specific capacity and a calculated maintenance capacity, the capacity increasing and / or continuous heating being started and / or a first warning being output if the specific capacity is deficient will, and / or
• j) comparing the calculated heating-up time with a parameterized maximum heating-up time, the output being increased in the event of a deficit in the specific power and / or continuous heating being started and / or a second warning message being output, and / or
• k) Calculating the snow depth from the difference between the fallen snow depth and the melted snow depth per unit of time and comparing the calculated snow depth with a parameterizable maximum permitted snow depth, whereby if there is a deficit in the specific power, the power increases and / or continuous heating begins and / or a third warning message is issued.

In the prior art, heating is required in normal operation when the heating is requested and the amount of snow cannot be melted when the heating time is long from low ambient temperatures. As a result, the turnout is snowed over and is no longer adjustable. The advantage of the invention is that the switch is prevented from being covered with snow in the operating temperature range.

• f1) Berechnen der Totzeit für das zumindest eine Weichensegment aus dem zeitlichen Verlauf der Weichentemperatur der Weiche (3) bei optimaler oder realer spezifischer Leistung,
• f2) Berechnen der Zeit t_A1 zum Erwärmen des zumindest einen Weichensegments von der Weichentemperatur der kalten Schiene der Weiche (3) und der Schmelztemperatur bis zur Weichenmindesttemperatur an zumindest einen Knoten,
• f3) Berechnen der Zeit t_A2 zum Schmelzen der Schneemenge während des Schritts f2) aus der Differenz aus vorhandener spezifischer Leistung abzüglich der Leistung zur Erhaltung der Weichenmindesttemperatur des zumindest einen Weichensegments,
• f4) Berechnen der Zeit t_A3 zum Schmelzen des gefallenen Schnees während des Schritts f3) aus der Differenz aus vorhandener spezifischer Leistung abzüglich der Leistung zur Erhaltung der Weichenmindesttemperatur des zumindest einen Weichensegments,
• f5) Berechnen der Zeit t_A4 zum Erwärmen des zumindest einen Weichensegments von der Differenz Weichenmindesttemperatur bis zur Weichensolltemperatur an den Knoten mit dem Weichentemperatursensor der Weiche (3),
• f6) Berechnen der Zeit t_A5 zum Schmelzen des gefallenen Schnees während des Schritts f5) aus der Differenz aus vorhandener spezifischer Leistung abzüglich der Leistung zur Erhaltung der Weichenmindesttemperatur des zumindest einen Weichensegments.

The calculation of the heating time in step f) can advantageously include the sub-steps

• f1) calculating the dead time for the at least one turnout segment from the time course of the turnout temperature of the turnout ( 3rd ) with optimal or real specific performance,
• f2) Calculating the time t _A1 for heating the at least one turnout segment from the turnout temperature of the cold rail of the turnout ( 3rd ) and the melting temperature up to the minimum switch temperature at at least one node,
• f3) Calculating the time t _A2 for melting the amount of snow during step f2) from the difference from the existing specific power minus the power for maintaining the minimum switch temperature of the at least one switch segment,
• f4) Calculating the time t _A3 for melting the fallen snow during step f3) from the difference from the existing specific power minus the power for maintaining the minimum switch temperature of the at least one switch segment,
• f5) Calculating the time t _A4 for heating the at least one turnout segment from the difference between the minimum switch temperature and the setpoint temperature at the nodes with the turnout temperature sensor of the turnout ( 3rd ),
• f6) Calculating the time t _A5 for melting the fallen snow during step f5) from the difference from the existing specific power minus the power for maintaining the minimum switch temperature of the at least one switch segment.

The above-described calculation of the heating time in step f) enables monitoring and early reporting of functional deficits in the point heating ( 1 ) instead of the occurrence of a fault.

• - Berechnen der optionalen Weichenendtemperaturen an zwei spezifischen Knoten des zumindest einen Weichensegments, welche dem Kopf-Backenschiene (20) und dem Kopf-Zungenschiene (21) als funktionsrelevante Stellen (19) der zumindest einen Weiche (3) entsprechen, wobei von der Weichenmindesttemperatur die berechneten Weichentemperaturen Kopf-Backenschiene und Kopf-Zungenschiene subtrahiert werden und die geringste davon der Betriebsgrenze-Umgebungstemperatur entspricht.

A partial aspect of the method according to the invention relates to a determination of the operating limit ambient temperature ( G _W-Tu ) the point heater ( 1 ), full

• - Calculating the optional turnout end temperatures at two specific nodes of the at least one turnout segment, which the head-stock rail ( 20th ) and the head-tongue rail ( 21 ) as functionally relevant positions ( 19th ) of at least one switch ( 3rd ), whereby the calculated switch temperatures of head-rail and head-tongue rail are subtracted from the minimum switch temperature and the lowest of these corresponds to the operating limit ambient temperature.

An advantage according to the invention is that existing point heaters can be individually and optimally adapted to the changed weather conditions.

• - Berechnen einer spezifischen Erhaltungsleistung bei Weichenmindesttemperatur T_min der Weiche (3), zuzüglich einer Weichenmindesttemperatur (T_W-min ) Toleranz ΔT_min , am Backenschienenfuß, einer Schmelzleistung für die maximale Schneemenge oder die bis dahin erfasste Schneemenge sowie einer Verdampfungsleistung für Schmelzwasser, und Vergleich der Summe daraus mit der erforderlichen spezifischen Leistung der Heizeinrichtung (29) des zumindest einen Weichensegments, wenn die erforderliche spezifische Leistung der Heizeinrichtung kleiner ist als die Summe aus Erhaltungsleistung und Schmelzleistung und Verdampfungsleistung Betriebsgrenze Schneehöhe überschritten ist. Ein weiterer Teilaspekt des erfindungsgemäßen Verfahrens bezieht sich auf eine projektspezifische Dimensionierung der Heizeinrichtungen (29) und deren erforderlicher spezifischer Leistung, umfassend - Berechnen einer spezifischen Leistung (P) der Heizeinrichtung zum Erreichen einer Weichensolltemperatur der Weiche (3) am Standort des Weichentemperatursensors und einer minimalen Weichentemperatur T_w-min der Weiche (3) an mindestes einem Kopf-Backenschiene (20) und/oder einem Kopf-Zungenschiene (21) für das zumindest eine Weichensegment über Berechnen der Summe aus Wärmeleitung, Strahlung und Konvektion in die Umgebung, Wärmekapazität und Latenter Wärme bei Schnee und Beregnung, bei vorhandenen Betriebsgrenzwerten aus minimaler Umgebungstemperatur, Schienenprofil, maximaler Windgeschwindigkeit und maximaler Schneehöhe pro Stunde, und
• - Erhöhen der spezifischen Leistung, wenn die berechnete reale spezifische Leistung kleiner ist als die spezifische Leistung, die der erforderlichen Schmelzleistung der in der Anheizzeit, die ab minimaler Umgebungstemperatur bis zum Erreichen einer Schienentemperatur von mindestens 0 °C berechnet wird, für die Schneemenge, die sich aus dem Produkt aus Anheizzeit und Schneehöhe pro Stunde ergibt, und der Verdampfungsleistung von restlichem Schmelzwasser und der erforderlichen spezifischen Erhaltungsleistung für eine Schienentemperatur von 0 °C an den funktionsrelevanten Stellen des zumindest einen Weichensegments entspricht.

Another aspect of the method according to the invention relates to a determination of the operating amount of snow ( G _W-hs ) the point heater ( 1 ), full

• - Calculate a specific maintenance performance at minimum switch temperature T _min the soft ( 3rd ), plus a minimum switch temperature ( T _W-min ) Tolerance ΔT _min , on the stock rail base, a melting capacity for the maximum amount of snow or the amount of snow recorded up to that point, and an evaporation capacity for melting water, and comparison of the sum thereof with the required specific capacity of the heating device ( 29 ) of the at least one turnout segment if the required specific output of the heating device is less than the sum of the maintenance output and the melting output and the evaporation output operating limit of snow depth is exceeded. Another aspect of the method according to the invention relates to project-specific dimensioning of the heating devices ( 29 ) and their required specific performance, comprising - calculating a specific performance ( P ) of the heating device to achieve a set point temperature of the turnout ( 3rd ) at the location of the turnout temperature sensor and a minimum turnout temperature T _w-min the soft ( 3rd ) on at least one head-stock rail ( 20th ) and / or a head-tongue rail ( 21 ) for the at least one turnout segment by calculating the sum of heat conduction, radiation and convection into the environment, heat capacity and latent heat in snow and irrigation, with existing operating limit values from minimum ambient temperature, rail profile, maximum wind speed and maximum snow depth per hour, and
• - Increase the specific output if the calculated real specific output is less than the specific output, the required melting output in the heating-up time, which is calculated from the minimum ambient temperature until a rail temperature of at least 0 ° C is reached, for the amount of snow arises from the product of heating time and snow depth per hour, and corresponds to the evaporation capacity of the remaining melt water and the required specific maintenance capacity for a rail temperature of 0 ° C at the functionally relevant points of the at least one turnout segment.

This has the advantage that point heaters ( 1 ) can be carried out according to the specific local environmental conditions, for example in the mountains differently than in the lowlands.

• - bei Betrieb der Weichenheizungsanlage (1) ein Einstellen der optimalen spezifischen Leistung für die Heizeinrichtungen (29), die dem Produkt aus spezifischer Leistung und einem Leistungsverhältnis von 25% bis 100 % entspricht, über die jeweiligen Schaltgeräte zum Einschalten und Ausschalten der Heizeinrichtungen (29) mittels Verändern der Einschaltdauer oder der Frequenz oder der Pulsweite oder Wellenpaketsteuerung oder Gruppenbetrieb erfolgt, und/oder
• - das Leistungsverhältnis zwischen 25 % und 100 % beträgt, wobei bei Betrieb der Weichenheizungsanlage (1) die spezifische Leistung P der linken Seite (5) der Weiche (3) und der rechten Seite (6) der Weiche (3) maximal dem Mittelwert und/oder Meridian der spezifischen Leistung der Heizeinrichtung (29) entspricht, und/oder
• - bei Betrieb der Weichenheizungsanlage (1) die berechnete spezifische Leistung Pop für die linke Seite (5) der Weiche (3) und die rechte Seite (6) der Weiche (3) maximal der spezifischen Leistung (P) der Heizeinrichtungen (29) entspricht, oder eine spezifische Leistungsdifferenz für die linke Seite (5) der Weiche (3) oder die rechte Seite (6) der Weiche (3) aus der Differenz von spezifischer Leistung (P) der Heizeinrichtungen (14) abzüglich berechneter spezifischer Leistung (P_op ) berechnet wird und bei positiver spezifischer Leistungsdifferenz der linken Seite (5) der Weiche (3) oder der rechten Seite (6) der Weiche (3) diese spezifische Leistungsdifferenz der jeweiligen anderen Seite der Weiche (3) zusätzlich zur spezifischen Leistung (P) der Heizeinrichtung (14) zu Verfügung gestellt wird, so dass ein gleichmäßiger zeitlicher Verlauf der Schienentemperaturen der Weiche (3) an der linken Seite (5) der Weiche (3) und an der rechten Seite (6) der Weiche (3) an den funktionsrelevanten Stellen der Weiche (3) erfolgt.

In a preferred embodiment of the method according to the invention

• - when operating the point heating system ( 1 ) setting the optimal specific power for the heaters ( 29 ), which corresponds to the product of specific performance and a performance ratio of 25% to 100%, via the respective switching devices for switching the heating devices on and off ( 29 ) by changing the duty cycle or the frequency or the pulse width or wave packet control or group operation, and / or
• - the performance ratio is between 25% and 100%, whereby when operating the point heating system ( 1 ) the specific performance P the left side ( 5 ) the switch ( 3rd ) and the right side ( 6 ) the switch ( 3rd ) maximum the mean and / or meridian of the specific performance of the heating device ( 29 ) corresponds, and / or
• - when operating the point heating system ( 1 ) the calculated specific power Pop for the left side ( 5 ) the switch ( 3rd ) and the right side ( 6 ) the switch ( 3rd ) maximum of specific performance ( P ) of the heating devices ( 29 ) or a specific power difference for the left side ( 5 ) the switch ( 3rd ) or the right side ( 6 ) the switch ( 3rd ) from the difference of specific performance ( P ) of the heating devices ( 14 ) minus calculated specific performance ( P _op ) is calculated and if there is a positive specific power difference on the left side ( 5 ) the switch ( 3rd ) or the right side ( 6 ) the switch ( 3rd ) this specific power difference of the other side of the switch ( 3rd ) in addition to the specific performance ( P ) of the heating device ( 14 ) is made available, so that the rail temperatures of the turnout ( 3rd ) on the left side ( 5 ) the switch ( 3rd ) and on the right side ( 6 ) the switch ( 3rd ) at the functionally relevant points of the switch ( 3rd ) he follows.

• - eine CPU zur Berechnung der Weichentemperaturen der Weiche (3) für zumindest ein Weichensegment, die mit der Steuereinrichtung über Kommunikationsmittel verbunden ist,
• - zumindest einen abseits der Weiche (3) angeordneten Anschlusskasten, der mindestens ein Schaltgerät aufweist, das über Leitungen mit den Heizeinrichtungen (29) der Weiche (3) verbunden sind, sowie Messmittel zur zeitlichen Erfassung von Betriebsstrom, Spannung und Isolationswiderstand und Mittel zur Begrenzung der maximalen Leistung aufweist,
• - zumindest ein Kommunikationsmittel, das in dem Anschlusskasten angeordnet und mit der Steuereinheit verbunden ist,
• - zumindest einen Niederschlagsensor zur Erfassung von Niederschlagsart und Niederschlagsmenge, der mit der Steuereinheit verbunden ist.

The above object is achieved in a second aspect of the present invention by a device for controlling and regulating a point heater ( 1 ) solved, the point heater ( 1 ) at least one on at least one switch ( 3rd ) arranged heating device ( 14 ), at least one switch temperature sensor ( 28 ) on the at least one switch ( 3rd ), at least one energy distribution with at least one heating outlet per switch ( 3rd ) and has at least one control device for controlling and regulating the switch temperature, comprising:

• - a CPU for calculating the switch temperatures of the switch ( 3rd ) for at least one turnout segment, which is connected to the control device via communication means,
• - at least one off the switch ( 3rd ) arranged junction box, which has at least one switching device that connects to the heating devices ( 29 ) the switch ( 3rd ) are connected, as well as measuring means for the temporal recording of operating current, voltage and insulation resistance and means for limiting the maximum power,
• at least one communication means, which is arranged in the connection box and connected to the control unit,
• - At least one precipitation sensor for recording the type and amount of precipitation, which is connected to the control unit.

The device according to the invention basically has the same advantages as the method according to the invention. In particular, the device according to the invention provides the equipment basis for a switch ( 3rd ) representatively represented by a switch segment, which both the left side ( 5 ) the switch ( 3rd ) as well as the right side ( 6 ) the switch ( 3rd ). In this way, the heating network according to the invention ( 26 , 27 ) over a representative cross section of the switch ( 3rd ) are formed with which the device according to the invention heats the entire switch ( 3rd ) is carried out as evenly as possible.

• 0 eine schematische Draufsicht auf eine Weiche 3,
• 1 eine schematische Schnittdarstellung eines Weichensegments mit anliegender Zungenschiene 10 und abliegender Zungenschiene 11,
• 2 eine zeitliche Darstellung der Erwärmung einer Weiche 3 mit einer Weichenheizung entsprechend dem Stand der Technik,
• 3 eine schematische Darstellung eines erfindungsgemäßen Wärmenetzes 26, 27 für ein Weichensegment der Weiche 3 bestehend aus Backenschiene 7, Zungenschiene 8, Gleitstuhlplatte 9 und Heizeinrichtung 14,
• 4 ein Modell zur Berechnung der Anheizzeit mit und/ ohne Schnee,
• 5 ein Beispiel für einen Programmablaufplan zur Dimensionierung der Leistung einer Heizeinrichtung 14 in Abhängigkeit projektspezifischer Betriebsgrenzwerte.
• 6 ein Beispiel für einen Programmablaufplan zur Bewertung der Funktion der Weichenheizung 1 in Abhängigkeit der Witterung und damit Nachweis der Verfügbarkeit der Weiche 3 im Winter mit vorhandener Leistung der Heizeinrichtung 14 und
• 7 ein Beispiel für einen Programmablaufplan (zur besseren Übersicht auf zwei Seiten verteilt) zur Steuerung und Regelung einer erfindungsgemäßen Weichenheizung 1.

Further objectives, features, advantages and possible applications result from the following description of exemplary embodiments not restricting the invention with reference to the figures. All of the described and / or illustrated features, alone or in any combination, form the subject matter of the invention, regardless of their combination in the claims or their relationship. Show it:

• 0 a schematic plan view of a switch 3rd ,
• 1 is a schematic sectional view of a switch segment with adjacent tongue rail 10th and remote tongue rail 11 ,
• 2nd a temporal representation of the heating of a switch 3rd with a point heater according to the state of the art,
• 3rd is a schematic representation of a heating network according to the invention 26 , 27 for a turnout segment of the turnout 3rd consisting of stock rail 7 , Tongue rail 8th , Sliding chair plate 9 and heating device 14 ,
• 4th a model for calculating the heating time with and / without snow,
• 5 an example of a program flow chart for dimensioning the performance of a heating device 14 depending on project-specific operating limits.
• 6 an example of a program flow chart for evaluating the function of the point heating 1 depending on the weather and thus proof of the availability of the switch 3rd in winter with the heating system available 14 and
• 7 an example of a program flow chart (distributed over two pages for a better overview) for the control and regulation of a point heater according to the invention 1 .

The invention is described in detail below, this description not restricting the scope of protection of the patent claims on the basis of specific embodiments.

In order to use as few switch temperature sensors as possible 28 To achieve the goals already mentioned above, the present invention consists, among other things, of the control and regulation as well as the dimensioning of the heating devices 14 and the determination of the operating limits of existing point heaters by evaluating the point temperatures of the point 3rd at the functionally relevant points 19th the soft 3rd in winter for the point heater according to the invention 1 by means of calculation. According to the invention, this takes place via the heating network 26 the left side 5 the soft 3rd and over the heating network 27 the right side 6 the soft 3rd for at least one turnout segment analogous to electrical flow fields by controlling the specific power of the heating device 14 the point heater according to the invention 1 by evaluation using a heating network 26 , 27 calculated temperatures at the turnout segment 34 , Turnout segment turnout center 35 and turnout segment 36 for the left side 5 the soft 3rd and the right side 6 the soft 3rd depending on the switch position, i.e. for the tongue rail resting on the stock rail 10th and for remote tongue rails 11 , and depending on the weather. The calculated optimal switch temperatures T _op the soft 3rd with a switch temperature sensor 28 recorded time course of the real turnout temperature Tw the soft 3rd from at least three measured values after the dead time of a heated rail with the switch temperature sensor 28 at least one switch 3rd compared. In the case of differences, including a tolerance, which can arise, for example, from wind and solar radiation, this time course is corrected via convection losses and radiation power.

The above-mentioned objects are achieved by thermal modeling of the temperature profile with division of the switch 3rd in turnout segments of the left side 5 and the right side 6 for the points of the turnout that are characteristic for the evaluation of the function 16 , Switch center 17th and point end 18th taking into account the distance between the stock rail 7 and tongue rail 8th due to the switch position, the rail profile, the type of sliding chair plate 9 with or without rollers, the type of precipitation and the amount of precipitation, the wind speed and the ambient temperature as well as possible thermal or wind insulation. Thereby, for the turnout segments when operating with the specific performance of the heating device 14 the time course of the switch temperatures top of the switch 3rd and the specific power losses calculated with iterative solution methods and with switch temperature sensors 28 recorded time course of the real turnout temperatures Tw the soft 3rd compared. In the event of differences, these are corrected taking into account a tolerance and at functionally relevant points 19th the soft 3rd which in winter for the function of the switch 3rd are decisive, so that when operating with determined weather-dependent optimal specific performance, the heating device 14 activated and a minimum rail temperature at these points T _min the switch is reached. This ensures uniform heating of the left side with minimal energy consumption 5 the soft 3rd and right side 6 the soft 3rd over the entire length of the switch 3rd achieved and thus high availability in winter guaranteed.

When dimensioning, the required specific performance of the heating device 14 determined based on local borderline environmental conditions. When determining the operating limits of the point heater according to the invention 1 the turnout end temperatures for existing turnout heaters T _wn the soft 3rd at functionally relevant points 19th at maximum environmental limit values determined where the point heater in question 1 with existing specific performance of the heating devices 14 works just fine in winter. This enables the operator to decide whether this operating limit is sufficient or not sufficient for his weather conditions.

For this purpose, local, project-specific and characteristic unfavorable environmental conditions and all types of switches should be used 3rd with a corresponding rail profile with a program the required specific performance of the heating device 14 for example, one meter length can be calculated for the heaters 14 are required so that the point heater according to the invention 1 works successfully with these limit values in winter. That is, the switch 3rd is kept free of snow and does not freeze. To evaluate the function, the function-relevant points 19th the soft 3rd Minimum rail temperatures of the switch 3rd defined and the power losses under these conditions from thermal radiation 30th , Convection 3rd ), Heat conduction 33 and heat storage 32 taking into account the installation location of the heating device 14 and the position of the tongue rail 8th on the turnout segments on the left 5 the soft 3rd and the right side 6 the soft 3rd at the tip of the switch 16 , Switch center 17th and point end 18th calculated. The sum of the power losses of each turnout segment on the left 5 the wich 3rd and / or the right side 6 the soft 3rd at which the minimum rail temperatures of the switch 3rd reached and the amount of snow is melted, corresponds to the required specific heating output for the respective side and the respective area of the switch 3rd . The heating devices have a length of up to 6 m. The required specific heating power of the heating devices is therefore advantageous 14 from the calculated maximum sum of the power loss of the turnout segments on the left side 5 the soft 3rd and the right side 6 the soft 3rd determined.

• - Weichenprofil, z.B. R54 mit unterschiedlichen Abmessungen und Gewicht an Weichenspitze 16, Weichenmitte 17 und Weichenende 18,
• - Schienensolltemperatur T_Soll der Weiche 3,
• - Schienenmindesttemperatur T_min der Weiche 3 und/oder minimale Umgebungstemperatur T_U-min ,
• - maximale Schneemenge h_S-max ,
• - maximale Anheizzeit beheizte Schiene t_An-max ,
• - maximale Windgeschwindigkeit u_max .

This determination is made in such a way that, for a certain rail profile, for example R54, minimum ambient temperatures and maximum amount of snow are specified and for functionally relevant points 19th of turnout segments at turnout tip 34 , Switch center 35 and point end 36 the time course and the heat losses of the heat pipe 33 , the melting capacities and the evaporation capacity Pv the optimal switch temperatures ( T _op ) are calculated and evaluated and whether the entire amount of snow is melted. The following project-specific entries are entered, which are the operating limits of the point heater according to the invention 1 represent, ie where the function of the switches 3rd should still be guaranteed in winter:

• - Turnout profile, e.g. R54 with different dimensions and weight at turnout tip 16 , Switch center 17th and point end 18th ,
• - Target rail temperature T _target the soft 3rd ,
• - Minimum rail temperature T _min the soft 3rd and / or minimum ambient temperature T _RPM ,
• - maximum amount of snow h _S-max ,
• - maximum heating time of the heated rail t _An-max ,
• - maximum wind speed u _max .

Calculating the final values of the power losses for the right side switch segment 6 the soft 3rd and the left side switch segment 5 the soft 3rd takes place at a turnout end temperature of the turnout 3rd which is at least the absolute sum of the minimum rail temperature T _min the soft 3rd or the ambient temperature T _U and the lower set point temperature (e.g. 7 ° C minus 4 ° C hysteresis results in 3 ° C) the minimum rail temperature of the soft 3 of the heated rails, for example stock rails 7 left and right (e.g. knot K Stock rail base) and / or the parameterized minimum temperature at the functionally relevant points 19th , for example + 1 ° C, the sum of the power losses of the required specific power of the heating device 14 in watts per meter for a length of the heating device 14 corresponds.

From the maximum amount of snow h _p , the horizontal surfaces of the turnout segment and the average density of snow, e.g. of 100 kg / m ³ , at air temperatures below 0 ° C and 200 kg / m ³ at air temperatures above 0 ° C and an average specific heat of fusion of, for example, 335 kJ / Kg, the melting capacity required for the amount of snow is determined in one hour. Snow begins to melt at 0 ° C. The total specific heater performance required 14 results from the sum of the power loss at 0 ° C and the melting capacity of the amount of snow between the start of heating and reaching the minimum rail temperature Tmin of the switch 3rd from 0 ° C on the foot stock rail, for example. The amount of snow fallen is determined from the amount of snow recorded and the time until the minimum rail temperature Tmin of the switch is reached 3rd that corresponds to the melting temperature of snow.

$${\text{T}}_{\text{Ko}-\text{Ba}}>={\text{T}}_{\text{min}}$$

$${\text{T}}_{\text{Fu}-\text{Zu}>=}\text{k}\times {\text{T}}_{\text{Soll}}$$

$${\text{T}}_{\text{Ko}-\text{Zu}>=}{\text{T}}_{\text{min}}$$

$${\text{T}}_{\text{GL}-\text{mi}>=}{\text{k}}_{\times }{\text{T}}_{\text{Soll}}$$

$${\text{T}}_{\text{Gl}-\text{au}>=}{\text{T}}_{\text{min}}$$

A successful function of the point heater according to the invention 1 in the winter at the functionally relevant points 19th the soft 3rd a minimum rail temperature T _min the soft 3rd on the left 5 the soft 3rd and right side 6 the soft 3rd ensure the minimum rail temperature T _min the soft 3rd corresponds to the melting temperature of ice and snow. These functionally relevant positions are: Stock rail head (Index Ko-Ba) Stock rail foot (Index Fu-Ba) Tongue rail head (Index Ko-Zu) Sliding chair plate -outside (Index GL-au) on the left side 5 the soft 3rd and the right side 6 the soft 3rd . At these functionally relevant points 19th there is a positive evaluation of the function of the point heater according to the invention 1 if the following conditions are met. The factor is taken into account k Temperature differences due to heat conduction between the locations $${\text{T}}_{\text{Fu}-\text{Ba}}>{\text{T}}_{\text{Should}}$$

$${\text{T}}_{\text{Knockout}-\text{Ba}}>={\text{T}}_{\text{min}}$$

$${\text{T}}_{\text{Fu}-\text{To}>=}\text{k}\times {\text{T}}_{\text{Should}}$$

$${\text{T}}_{\text{Knockout}-\text{To}>=}{\text{T}}_{\text{min}}$$

$${\text{T}}_{\text{GL}-\text{mi}>=}{\text{k}}_{\times }{\text{T}}_{\text{Should}}$$

$${\text{T}}_{\text{Eq}-\text{au}>=}{\text{T}}_{\text{min}}$$

$${\text{T}}_{\text{Ko}-\text{Ba}-\text{min}}=0°\text{C}$$

$${\text{T}}_{\text{Fu}-\text{Zh}-\text{min}}=\text{Weichensolltemperatur}*\text{k}\left(\text{mit k}=\mathrm{0,5}\right)$$

$${\text{T}}_{\text{Ko}-\text{Zu}-\text{min}}=0°\text{C}$$

$${\text{T}}_{\text{GL}-\text{mi}-\text{min}}=\text{Weichensolltemperatur}*\text{k}\left(\text{mit k}=\mathrm{0,5}\right)$$

$${\text{T}}_{\text{GL}-\text{au}-\text{min}}=0°\text{C}$$

Anheizzeit t_A <= t _A-max
geschmolzene Schneemenge während der Anheizzeit t Am größer gefallene Schneemenge h_s durch Bewerten der vorhandenen spezifischen Leistung der Heizeinrichtung 14 mit der erforderlichen Erhaltungsleistung P_erh zuzüglich Schmelzleistung für die gefallenen Schneemenge.So that only one program is required for all turnout types, the evaluation is carried out on typical turnout segments for the left side 5 the soft 3rd and the right side 6 the soft 3rd over the areas switch point 35 , Switch center 36 and point end 37 . Parameterizable values for the left side are evaluated 5 the soft 3rd and the right side 6 the soft 3rd a turnout segment, for example: $${\text{T}}_{\text{Fu}-\text{Ba}-\text{min}}=\text{Turnout target temperature}*\text{k}\left(\text{with K}=1.5\right)$$

$${\text{T}}_{\text{Knockout}-\text{Ba}-\text{min}}=0°\text{C.}$$

$${\text{T}}_{\text{Fu}-\text{Zh}-\text{min}}=\text{Turnout target temperature}*\text{k}\left(\text{with K}=0.5\right)$$

$${\text{T}}_{\text{Knockout}-\text{To}-\text{min}}=0°\text{C.}$$

$${\text{T}}_{\text{GL}-\text{mi}-\text{min}}=\text{Turnout target temperature}*\text{k}\left(\text{with K}=0.5\right)$$

$${\text{T}}_{\text{GL}-\text{au}-\text{min}}=0°\text{C.}$$

Heating time t _A <= t _A-max
melted amount of snow during the heating time t On the larger amount of snow h _s by evaluating the existing specific performance of the heater 14 with the required maintenance performance P _erh plus melting capacity for the amount of snow fallen.

With the calculation method in connection with a device for control and regulation, the following measures can be taken to ensure the function of the switch 3rd activated with minimal energy consumption over the entire operating range.

Setting the calculated optimal heater performance 14 via group control, wave packet control, pulse width modulation and frequency change depending on the type of heating devices

Arrangement of additional heating devices 29 on the tongue rail 8th and / or the sliding chair plates 9 , which are activated and controlled via the calculation model in terms of time or via power distribution in such a way that the functionally relevant points are increased without increasing the connected load 19th be heated evenly over time and thus no time disadvantages of individual parts of the switch 3rd enter.

In the case of deficits in the turnout temperatures of the turnout that are forecast using the calculation method 3rd due to insufficient specific performance of the heating device 14 on the remote tongue rail 11 there is an early warning message or a switch if possible 3rd change over and / or preheat to a low target rail temperature of the switch 3rd , so that in extreme weather conditions, e.g. heavy snowfall, the snow melts immediately.

For the successful function of the point heater according to the invention 1 is uniform heating of the functionally relevant points 19th the soft 3rd the adjacent and remote tongue rail 8th required. Because the switch 3rd is continuously changed in operation depending on the direction of travel and no sensors for detecting the position of the tongue rail for the switch setting 8th are possible, will suggest, by evaluating the calculated temporal course of the turnout temperature of the turnout 3rd on the left side 5 the soft 3rd and on the right side 6 the soft 3rd the position of the tongue rails 8th to detect

• Heizeinrichtung 14 an den Backenschienen 7 und zusätzliche Heizeinrichtung 29 an den Zungenschienen 8 und bei Beginn des Betriebes Anheizen von ersten Schienen mit 100 % spezifischer Leistung der Heizeinrichtung 14, wobei erste Schienen Backenschienen 7 oder Zungenschiene 8 oder Gleitstuhlplatten 9 sein können, und bei Erreichen der Schienensolltemperatur T_Soll der Weiche 3 an der ersten Schiene Reduzieren der jeweiligen spezifischen Leistung der Heizeinrichtung 14 oder 29 auf maximal spezifische Erhaltungsleistung P_Erh oder geringer oder Ausschalten derselben und Aktivieren der zusätzlichen Heizeinrichtung 29 an der Zungenschiene 7 oder den Gleitstuhlplatten 9 mit der verbleibenden spezifischen Leistung ab dieser Zeit und nur in den Heizpausen der Heizeinrichtung 14 der ersten Schienen bspw. über Gruppenbetrieb während zyklischer Taktzeiten bei elektrischen Heizstäben.

Heating equipment configurations are:

• Heating device 14 on the stock rails 7 and additional heating device 29 on the tongue rails 8th and at the start of operation, heating up the first rails with 100% specific output of the heating device 14 , with first rails stock rails 7 or tongue rail 8th or sliding chair plates 9 can be, and when the target rail temperature is reached T _target the soft 3rd on the first rail, reduce the respective specific output of the heating device 14 or 29 to maximum specific maintenance performance P _Erh or less or turn them off and activate the additional heater 29 on the tongue rail 7 or the sliding chair plates 9 with the remaining specific power from this time and only during the heating breaks of the heating device 14 the first rails, for example via group operation during cyclical cycle times for electric heating elements.

If deficits are calculated before a heating request, e.g. due to snow at the weather station, additional heating regime "preheating" is activated, e.g. in the event of possible extreme weather conditions, via separate weather data from a local weather station or via a weather service such that a second rail setpoint temperature for the switch 3rd is calculated and the switch heater according to the invention 1 is switched on via preheating and to this second setpoint rail temperature of the switch 3rd is regulated, the second setpoint rail temperature of the switch 3rd is so large that when the actual weather extremes occur, the snow melts and the function of the switch 3rd guaranteed and if the extreme weather does not occur, the preheating is ended.

When equipping the stock rail 7 and the tongue rail 8th and / or the sliding chair plates 9 with additional heating elements 29 the heating devices are activated during operation during the heating-up period 14 always one after the other, ie first activate the heating device 14 the first rail with a power ratio of 100% and after reaching the target rail temperature of the switch 3rd Activate the heater 29 the second rail in the heating breaks of the heating device 14 the first rail and in normal operation, ie when both rails have the target rail temperature of the switch 3rd have group operation or wave packet control or simultaneous heating operation of all heating devices 14 , 29 with reduced specific power or active heating time, the sum of the specific power of the heating devices 14 , 29 the left side 5 the soft 3rd and the right side 6 the soft 3rd maximum of the specific power of the heating device 14 correspond.

Evaluate snow melting via the power balance during the heating-up time, in that the specific heating power is greater than or equal to the specific maintenance power plus the melting power for snow

Correction of the calculated time profile of the setpoint rail temperature 3rd with the actually recorded time course of the turnout temperature of the turnout 3rd using switch temperature sensor 28 taking into account radiant heat from solar radiation and wind influence via convection.

A detailed description of the figures is given below.

In 0 is a switch 3rd shown schematically in plan view. The soft 3rd is divided into turnout tips 16 , Switch center 17th and point end 18th . They are stock rails 7 and tongue rails 8th shown. The assignment of the right side 6 the soft 3rd takes place from the tip of the tongue 16 in the direction of view (reference number 2nd ) at the end of the switch 18th . On the left side 5 the soft 3rd is the remote tongue rail 11 and on the right side 6 the soft 3rd is the adjacent tongue rail 10th shown. On a stock rail 7 , here on the left 5 the soft 3rd , is a turnout temperature sensor 28 arranged. In the area of the turnout tip 16 is, for example, a turnout segment 34 , in the area of the switch center 17th is a turnout segment 35 and in the turnout area 18th is a turnout segment 36 each for the left side 5 the soft 3rd and the right side 6 the soft 3rd arranged. The switch temperature sensor 28 is on the turnout tip on the right side 6 the soft 3rd or on the left 5 the soft 3rd . Furthermore, there are the support lugs in the support lug area 13 shown, these serve on the side of the adjacent tongue rail 10th supporting the tongue splint 8th opposite the stock rail 7 when driving on the tongue rail 8th by train.

In 1 is a schematic sectional view of the switch 3rd out 0 on the turnout segment 34 with the left side 5 the soft 3rd and right side 6 the soft 3rd shown. On the left side 5 the soft 3rd is the remote tongue rail 11 and on the right side 6 the soft 3rd the adjacent tongue splint 12th shown. The functionally relevant positions 19th the soft 3rd in winter are on the left 6 the soft 3rd through the evaluation points ( 37 to 43 shown. Through the point heater according to the invention 1 these functionally relevant positions 19th , characterized by the evaluation points 37 to 43 in winter with negative ambient temperatures so that the snow or ice on it is melted. The evaluation points 37 to 43 on the left side 5 and on the right side ( 69 the switch the switch 3rd are the evaluation points of the foot-stock splint 37 , Bar stock rail 38 , Head stock rail 39 , Foot-tongue rail 40 , Head-tongue splint 41 , Middle sliding chair plate 42 and outside sliding chair plate 43 represented, each by knot K of the heating network 26 , 27 are represented and the functionally relevant positions 19th the right side 6 the soft 3rd and the left side 5 the soft 3rd correspond. The switch temperature sensor 28 is on the left stock rail 7 between two thresholds 24th arranged and the real turnout temperatures Tw detected on the stock rail 7 left side 5 the soft 3rd can with the calculated optimal switch temperatures at this functionally relevant point 19th with the calculated optimal switch temperatures T _{W op} compared and corrected for differences. The route of the switch is in operation 3rd by adjusting the tongue rails 8th constantly changing by on the left side 5 the soft 3rd and right side 6 the soft 3rd the tongue rail 8th alternately on or off the stock rail 7 is. Sensors for detecting the position of the tongue rail 8th are not available. Detection of the position of the tongue rails 8th on the stock rails 7 adjacent or remote is done by evaluating the calculated optimal switch temperatures T w- _op at the respective evaluation points of the functionally relevant positions 19th , preferably at the evaluation point head-tongue rail 41 . The switch is equipped with a heating device 14 heated on the stock rail base.

In 2nd is at the time when operating a point heater according to the state of the art t ₁ due to snowfall and a heating request "On" generated thereby, the time course of the real turnout temperature T _W-Fu-Ba on a rail on which the heating device 14 is arranged, for example on the foot stock rail, and the time course of the real switch temperature T _W-Au- GL on one not with heating device 14 provided rail, shown at a functionally relevant point of a switch, for example. After a dead time determined by the mass, the real turnout temperature increases T _W-Fu-Ba on the stock rail equipped with a heater. When the set point temperature is reached T _target for now t ₆ the heating is switched off with two-point control and after a slight overshoot of the real switch temperature due to the mass of the rail up to the time t ₇ cools this up to the time t ₈ and the heating current ( I _N ) is switched on again at this time. The time of t ₁ to t ₆ is called heating time t _A and the time t ₆ to t ₉ , designated with control time. The one located away from the heater and not with the heater 14 Provided sliding chair plate is only warmed up very slowly and at the time t ₆ a very low real switch temperature T _{W outer GL} which is far below the set point temperature.

At the time t ₆ the parameterized hysteresis of 4 ° C, for example, switches off the heating current for all the heating devices of the switch, so that cooling also starts on the sliding chair plate. The Turnout temperature difference ΔT _W for now t ₆ between the foot stock rails and sliding chair platform is very large. This switch temperature difference ΔT _W is so high at an ambient temperature of, for example, - 15 ° C that the switch temperature on the outside of the sliding chair plate is less than 0 ° C even after a very long time and the switch sets ice at this point and can freeze. In 2nd is the time course of the heating current IN with heating request On shown, the during operation between zero and maximum heating current IN is switched on and off depending on the point temperature at the base of the stock rail and this results in power peaks between zero and nominal current. At the times t ₃ , t ₄ and t ₅ the temperatures on the turnout temperature sensor ( 28 ) measured and for evaluating or correcting the calculated optimal switch temperatures.

In 3rd is the turnout for turnout segment 3rd a heating network according to the invention 26 for the left side 5 the soft 3rd and partly an analog heating network 27 for the right side 6 the soft 3rd according to a sectional view 1 at any area of the switch 3rd shown above the knot K Ambient temperature K _TU are connected. Heaters 14 , 29 are, for example, on the stock rail 7 arranged on the inside of the stock rail base. The heating network 26 for the left side 5 the soft 3rd and the heating network 27 for the right side 6 the soft 3rd are based on a sectional view along the sliding chair plate 9 on the left 5 the soft 3rd and the opposite sliding chair plate 9 On the right side 6 the soft 3rd and the cross section of the stock rail 7 and the tongue rail 8th on the left 5 the soft 3rd and stock rail 7 and tongue rail 8th On the right side 6 the soft 3rd at any turnout area 4th the soft 3rd with symbols heating device 29 , Symbols heat radiation 30th , Symbols convection 31 , Symbols heat conduction 33 and symbols heat storage 32 between the functionally relevant positions 19th the soft 3rd by knots K be represented.

In the heating network 26 the left side 5 the soft 3rd is between the ambient temperature T _U by knots K Ambient temperature K _TU is represented, and functionally relevant positions 19th , also by knots K represented, there is a heating network that will be calculated using known rules. The knots K for the functionally relevant positions 19th the soft 3rd for the heating network 26 for the left side 5 the soft 3rd and for the heating network 27 for the right side 6 the soft 3rd are the same and according to the evaluation points 37 to 43 , but the power loss of the adjacent tongue rail 10th and remote tongue rail 11 are different. The following table shows the relationship between the functionally relevant positions 19th , the corresponding node K and the required turnout temperature Tw that at the respective node K with the label T _{W op} is calculated and evaluated in a separate program for the heating network 26 for the left side 5 the soft 3rd . The heating network 27 for the right side 6 the switch 3 is analogous to this and over the knot K Ambient temperature K _TU connected. Name of functionally relevant position 19 Knot K Required turnout temperature T _W in degrees Celsius Ambient temperature K _TU Temperature range + 10 ° C to - 20 ° C Stock rail foot left side K _Fu-Ba-Li greater than k times the nominal rail temperature Stock rail bar left side K _St-Ba-Li Greater or equal minimum rail temperature Stock rail head left side K _Ko-Ba-Li Greater or equal minimum rail temperature Tongue rail head left side K _Ko-Zu-Li Greater or equal minimum rail temperature Tongue rail bridge on the left side K _St-Zu-Li Greater or equal minimum rail temperature Tongue rail foot left side K _Fu-Zu-Li Greater or equal minimum rail temperature Sliding chair plate-middle left side K _Gl-mi-Li Greater or equal minimum rail temperature Sliding chair plate outside left side K _Gl-au-Li Greater or equal minimum rail temperature

To calculate the turnout temperatures of the turnout 3rd and the power dissipation, the turnout segment is broken down into sections and each section is separated by a node K represents the average switch temperature Tw of the assigned section. The size of the sections or the number of nodes K depend on the required replication accuracy. For all nodes K the power losses and thermal resistances and thermal capacities from the material properties, the geometric sizes and the prevailing loads from heating current IN and environment calculated. From the connection of the nodes K resistors, capacitors and voltage sources create a network that can be solved numerically with the help of knots and meshes. Will the current account for a node K created, the Kirchhoff theorem (knot theorem) applies. $$P_S+P_K+P_L=P_{Lei}+P_c$$

According to the 2nd Kirchhoff theorem (mesh set) it follows that along a closed line, ie a mesh, the sum of the signed temperature differences is zero. A software program is used to calculate the power losses and the heat transfer processes. The temperature-dependent heat outputs and thermal resistances are calculated according to the known calculation bases and at the functionally relevant points 19th the soft 3rd that in the heating network 26 , 27 through knots K are represented, and taking into account the heat capacities, the final temperature and the temporal course of the switch temperatures are calculated.

In 4th is the heating time t _A shown. If the conditions for heating operation are fulfilled, for example when there is snow, the heating and the heating devices are put into operation via the heating request signal from the control unit 14 on the stock rails 7 are switched on and after reaching the set point temperature T _target regulated via two-point control with hysteresis and thereby the parts of the switch 3rd warmed up. The not with heater 14 provided tongue rails 8th and sliding chair plates 9 are heated by heat conduction and radiation. The heating time t _A starts when the heating is activated and ends when the set point temperature is reached T _target on a switch temperature sensor 28 that is under the foot on a stock rail 7 is arranged. The duration of the heating time t _A is dependent on many factors and should be calculated, monitored and, if necessary, appropriate measures taken to ensure availability.

The calculation of the heating time t _A is done for at least one turnout segment for the left side 5 the soft 3rd and the right side 6 the soft 3rd in several steps, taking into account times in which the heating of the turnout segment up to the minimum turnout temperature T _W-min the soft 3rd , Melt snow, evaporate water and then up to the set point temperature T _target the soft 3rd he follows. In 4th is the time course of the turnout temperature T _W-Fu-Ba the soft 3rd at the foot of a stock rail 7 and the switch temperature T _W-GL-au outside the switch 3rd the sliding chair plate 9 on one side, for example the left side 5 the soft 3rd , shown. The individual time periods are explained below. Due to the inertia there is a dead time during operation t _T of t ₁ to t ₂ . The dead time t _T is being computed.

$$\tau =\left(\raisebox{1ex}{$1$}\!\left/ \!\raisebox{-1ex}{$\left(1-\left(\raisebox{1ex}{$abs{T}_u$}\!\left/ \!\raisebox{-1ex}{$(1-\left(abs{T}_K-T_u\right)$}\right.\right)\right)$}\right.\right)$$

The heating time t _A is the time until the melting temperature of snow is reached t _2.1 . From time t ₂ becomes the switch 3rd up to the melting temperature T _S warmed up at the moment t _2.1 is achieved. The calculation of the heating time t _A takes place via thermal resistance determined with the heating network model R _th and heat capacity C _th and the power loss of the switch 3rd cold rail based on the time course starting from the switch temperature T _K the soft 3rd until the melting temperature is reached T _S for example using the formulas $$t_{A1}=\tau \text{ln}\tau {\text{= R}}_{tH}{\mathrm{C.}}_{tH}$$

$$\tau =\left(\raisebox{1ex}{$1$}\!\left/ \!\raisebox{-1ex}{$\left(1-\left(\raisebox{1ex}{$abs{T}_u$}\!\left/ \!\raisebox{-1ex}{$(1-\left(abs{T}_K-T_u\right)$}\right.\right)\right)$}\right.\right)$$

The time to melt the amount of snow that has fallen or is required for a specific project consists of two part-times t _A2 and t _A3 . During the time t _A2 becomes the time to melt the amount of snow from the time t _A1 calculated and over time t _A3 will that during the time t _A2 fallen amount of snow calculated. The melting capacity per hour is calculated from the amount of snow h _p and the horizontal surfaces of the turnout segment and an average density of snow, for example of 100 kg / m ³ at an air temperature of less than 0 ° C and 200 kg / m ³ at an air temperature of more than 0 ° C and an average specific heat of fusion of, for example, 335 kJ / kg . Snow begins to melt at 0 ° C. The specific power is therefore calculated, for example, at a switch temperature of 0 ° C on the stock rail 7 taking into account the required optimal specific performance of the heating device 14 to maintain the melting temperature of the stock rail 7 , which corresponds to the sum of the power losses at this melting temperature.

The calculation of the total heating time t _A2 plus t _ANH3 for melting the entire amount of snow from the heating time t _A1 and the heating time t _A2 is the product of the melting capacity per hour and the sum of time t _ANH1 and time t _ANH2 and dead time t _T .

After the snow has melted, the switch becomes 3rd warmed further. The heating time t _A4 currently starts t _2.3 and ends when the target rail temperature is reached T _target the soft 3rd through the switch temperature sensor 28 . The calculation of the heating time t _A4 takes place via the thermal resistance determined with the thermal network model R _th and heat capacity C _th and the power loss based on the time course starting from the melting temperature until reaching the set point temperature analogous to point 1 with a corresponding absolute point temperature from the difference between the set point temperature and the melting temperature.

During the heating up period t _A5 the snow from the heating up time t _A4 melted. The calculation is carried out analogously to the heating time t _A2 respectively. t _A3 .

The total heating time t _A takes time t ₁ to t ₇ and is the sum of dead time and heating times t _A1 to t _A5 determined and evaluated.

1. 1. Schritt: Start
2. 2. Schritt: Parametereingabe

   Die Parameter sind:

   minimale Umgebungstemperatur T_U-min Weichensolltemperatur T_Soll der Weiche 3 Weichenmindesttemperatur T_W-min der Weiche 3 maximale Windgeschwindigkeit v_max , maximale Schneemenge in cm pro Zeiteinheit h _S-max , Weichenprofil R

3. 3. Schritt: Parametrieren funktionsrelevanter Stellen Funktionsrelevante Stellen (19) sind bspw. Weichentemperatur Fuß-Backenschiene an- und abliegend linke Seite (T _Fu-Ba-an , T _Fu-Ba-ab ) Weichentemperatur Kopf-Backenschiene an- und abliegend (T _Ko-Ba-an , T _Ko-Ba-ab ) Weichentemperatur Kopf-Zungenschiene an- und abliegend (T _Ko-Zu-an , T _Ko-Zu-ab ) Weichentemperatur Gleitstuhl-außen an- und abliegend (T _GL-au-an , T_GL-au-ab ) Spezifische Schneemenge an- und abliegend (h _S-an , h _S-ab ) an Weichenspitze 16, Weichenmitte 17 und Weichenende 18 jeweils eines Weichensegments. Die Heizeinrichtungen 14 sollen bspw. an den Backenschienen 7 angebracht werden, der Einbau der Heizeinrichtungen 14 erfolgt am Schienenfuß, die Weiche 3 soll ohne Wärme- bzw. Winddämmung ausgerüstet werden. Jede funktionsrelevante Stelle 19 wird durch einen Knoten K mit hier nicht näher bezeichneter Ortsangabe repräsentiert.
4. 4. Schritt: Berechnen der Weichentemperaturen und spezifischen Verlustleistungen ΣP_V1 für 1. Weichensegment mittels Wärmenetzmodell aus den Stoffeigenschaften, den geometrischen Größen und den eingegebenen Parametern und Ausgabe der Summe Verlustleistung des Weichensegments und der Weichentemperaturen für die funktionsrelevanten Stellen 19 anliegende und abliegende Seite des Weichensegments
5. 5. Schritt: Berechnen spezifische Verlustleistungen ΣP_Vn für weitere Weichensegmente analog 4. Schritt
6. 6. Schritt: Die erforderliche spezifische Heizleistung P_erf ergibt sich aus der Summe der Verlustleistungen ΣP_Vn jedes Weichensegments.
7. 7. Schritt: Prüfen, wird mit der berechneten spezifischen Leistung an dem Standort des Weichentemperatursensors, anliegende oder abliegende Seite, die Weichensolltemperatur erreicht? Bei „Ja“ weiter zu Schritt 10., bei „Nein“ weiter zu Schritt 8.
8. 8. Schritt: Bewertung Die berechnete Weichenendtemperatur der Weiche 3 am Fuß Backenschiene anliegende Seite T_W-Fu-Ba-an oder abliegende Seite T_W-Fu-Ba-ab ist kleiner als die Weichensolltemperatur T_Soll der Weiche 3, Ergebnis ist Weichenendtemperatur der Weiche 3 an Backenschienenfuß (T_W-Fu-Ba ) ist zu gering, die Weichensolltemperatur T_Soll der Weiche 3 wird nicht erreicht, weiter mit Schritt 9.
9. 9. Schritt: Erhöhen der spezifischen Leistung P der Heizeinrichtung 14 um einen Leistungszuschlag p von bspw. 10 Watt pro Meter und Wiederholung der Berechnung nach Schritt 4.
10. 10. Schritt: Prüfen, ist die berechnete Weichenendtemperatur der Weiche 3 am Kopf Backenschiene anliegende Seite T_W-Ko-Ba-an oder abliegende Seite T_W-Ko-Ba-ab kleiner als die Weichenmindesttemperatur T_W-Min der Weiche 3? Ist bspw. die berechnete Weichentemperatur der Weiche 3 an Kopf-Backenschiene T_op-Ko-Ba der anliegenden oder abliegende Seite kleiner als die parametrierte Weichenmindesttemperatur T_W-Min , weiter mit Schritt 9. Ist die berechnete Weichentemperatur der Weiche 3 an Kopf-Backenschiene anliegende und abliegende Seite (T _op-Ko-Ba-an , T _op-Ko-Ba-ab ) größer oder gleich der Schienenmindesttemperatur der Weiche 3, weiter zu Schritt 11.
11. 11. Schritt: Prüfen, ist die berechnete Weichenendtemperatur der Weiche 3 am Kopf-Zungenschiene 21 anliegende Seite T_op-Ko-zu-an oder abliegende Seite T_W-Ko-Zu-ab kleiner als die Weichenmindesttemperatur T_W-Min der Weiche 3? Bei „JA“ weiter zu Schritt 9., bei „Nein“ weiter zu Schritt 12.
12. 12. Schritt: Prüfen, ist die berechnete Weichenendtemperatur der Weiche 3 an Außen-Gleitstuhlplatte anliegende Seite T_{W-GL-au -an} oder abliegende Seite T_W-GL-au-ab kleiner als die Weichenmindesttemperatur T_W-Min der Weiche 3? Bei „JA“ weiter zu Schritt 9., bei „Nein“ weiter zu Schritt 13.
13. 13. Schritt: Schneemenge wird geschmolzen Prüfen, wird die maximale Schneemenge geschmolzen oder nicht über Vergleich der Summe aus berechneter spezifischer Erhaltungsleistung P_Erh bei Weichenmindesttemperatur T_W-Min der Weiche 3 und spezifischer Schmelzleistung P_Sm für die maximale Schneemenge h_S mit der berechneten spezifischen Leistung (P_op )? Ist die berechnete spezifische Leistung P_op größer oder gleich der Summe aus Erhaltungsleistung P_Erh und Schmelzleistung Psm, weiter zu Schritt 14., sonst weiter zu Schritt 9.
14. 14. Schritt: Ausgabe der erforderlichen spezifischen Leistung Heizeinrichtung P für eine Weichenheizung 1, die im automatischen Betrieb bis zu den Eingabeparametern die Verfügbarkeit der Weiche im Winter bei geringen Energieverbrauch gewährleistet.

In 5 is a program flow for the dimensioning of a point heater according to the invention 1 with calculation of the required specific power of the heating devices 14 displayed depending on all possible project-specific input values, parameters and environmental conditions.

1. Step 1: start
2. Step 2: entering parameters

   The parameters are:

   minimum ambient temperature T _RPM Turnout target temperature T _target the soft 3rd Switch minimum temperature T _W-min the soft 3rd maximum wind speed v _max , maximum amount of snow in cm per unit of time h _S-max , Switch profile R

3. Step 3: Parameterize function-relevant positions Function-relevant positions ( 19th ) are, for example, switch temperature of the foot and stock rail on and off the left side ( T _Fu-Ba-an , T _Fu-Ba-ab ) Switch temperature head-cheek rail on and off ( T _Ko-Ba-an , T _Ko-Ba-ab ) Switch temperature head-tongue rail on and off ( T _Ko-Zu-an , T _Ko-Zu-ab ) Switch temperature outside and outside of the sliding chair ( T _GL-au-an , T _GL-au-ab ) Specific amount of snow on and off ( h _S-an , h _S-down ) at the turnout tip 16 , Switch center 17th and point end 18th one turnout segment each. The heaters 14 should, for example, on the stock rails 7 be installed, the installation of the heating devices 14 takes place at the rail foot, the switch 3rd should be equipped without thermal or wind insulation. Every functionally relevant position 19th is through a knot K represented with location not specified here.
4. Step 4: Calculate the switch temperatures and specific power losses ΣP _V1 for 1st turnout segment using a heat network model from the material properties, the geometric sizes and the entered parameters and output of the total power loss of the turnout segment and the turnout temperatures for the functionally relevant points 19th adjacent and remote side of the switch segment
5. Step 5: Calculate specific power losses ΣP _Vn for further turnout segments analogous to step 4
6. Step 6: The specific heating power required P _erf results from the sum of the power losses ΣP _{Vn of} each turnout segment.
7. 7th step: Check, is the setpoint temperature reached with the calculated specific power at the location of the turnout temperature sensor, adjacent or remote side? If yes, go to step 10th ., with "No" continue to step 8th .
8. Step 8: Evaluation The calculated turnout end temperature of the turnout 3rd side resting on the stock rail T _W-Fu-Ba-an or remote side T _W-Fu-Ba-ab is lower than the set point temperature T _target the soft 3rd , The result is the turnout end temperature of the turnout 3rd on stock rail base ( T _W-Fu-Ba ) is too low, the set point temperature T _target the soft 3rd is not reached, continue with step 9 .
9. Step 9: Increase specific performance P the heater 14 by a power surcharge p of, for example, 10 watts per meter and repeating the calculation after step 4th .
10. Step 10: Check is the calculated turnout end temperature of the turnout 3rd side resting on the head stock T _W-Ko-Ba-an or remote side T _W-Ko-Ba-ab less than the minimum switch temperature T _{W min} the soft 3rd ? For example, the calculated turnout temperature of the turnout 3rd on head-rail T _op-Ko-Ba the adjacent or remote side is less than the parameterized minimum switch temperature T _{W min} , continue with step 9 . Is the calculated turnout temperature of the turnout 3rd side resting against head-cheek rail ( T _op-Ko-Ba-an , T _op-Ko-Ba-ab ) greater than or equal to the minimum rail temperature of the switch 3rd , continue to step 11 .
11. Step 11: Check, is the calculated turnout end temperature of the turnout 3rd on the head-tongue rail 21 adjacent side T _op-Ko-zu-an or remote side T _W-Ko-Zu-ab less than the minimum switch temperature T _{W min} the soft 3rd ? If yes, go to step 9 ., with "No" continue to step 12th .
12. Step 12: Check, is the calculated turnout end temperature of the turnout 3rd side lying on the outer sliding chair plate T _{W-GL-au -an} or remote side T _W-GL-au-ab less than the minimum switch temperature T _{W min} the soft 3rd ? If yes, go to step 9 ., with "No" continue to step 13 .
13. Step 13: Amount of snow is melted Check whether the maximum amount of snow is melted or not by comparing the sum of the calculated specific maintenance performance P _Erh at minimum switch temperature T _{W min} the soft 3rd and specific melting capacity P _Sm for the maximum amount of snow h _p with the calculated specific power ( P _op )? Is the calculated specific power P _op greater than or equal to the sum of maintenance work P _Erh and melt power Psm, go to step 14 ., otherwise go to step 9 .
14. Step 14: Output of the required specific heater power P for a point heater 1 which, in automatic operation up to the input parameters, guarantees the availability of the turnout in winter with low energy consumption.

In 6 is the program sequence for demonstrating the function of the point heater according to the invention 1 depending on the minimum ambient temperature T _u , the existing specific power heater P , the set point temperature T _target the soft 3rd at maximum wind speed v _max for the rail profile R the soft 3rd as well as a possible maximum amount of snow per hour h _S-max and location of the heaters 14 on stock rail 7 and / or tongue rail 8th and / or sliding chair plate 9 shown. With such a method, the limit of the function of the point heater according to the invention can be 1 and thus the availability of the switch 3rd in winter for a standard point heater 1 be determined and evaluated, even when operating with the current air temperature, amount of snow per hour and wind speed v. In 6 the availability of the switch 3rd in winter depending on the turnout temperature of the turnout 3rd at the functionally relevant points 19th the far (right) side 6 the soft 3rd and the adjacent page 5 the soft 3rd Head-stock rails, head-tongue rail and outer sliding chair plate by comparison with the minimum switch temperature T _{W min} the soft 3rd and the function snow melting during the heating-up time t _APPENDIX over comparison of specific power heater P with the required specific power Perf, which results from the sum of the maintenance power PErh and the heat output PSm, and determines the possible deficits or the function of the point heater 1 depending on the weather confirmed.

• Schritt1: Start des Programmes
• Schritt 2: Eingabe von minimal zu erwartender Umgebungstemperatur T_Umin , spezifischen Leistungen Heizeinrichtung P, Weichensolltemperatur T_Soll , maximaler Windgeschwindigkeit Vmax, Schienenprofil R der Weiche 3, maximaler Schneemenge pro Stunde hs und Standort der Heizeinrichtungen 14 an Backenschiene 7 und/oder Zungenschiene 8 und/oder Gleitstuhlplatte 9, Weichenmindesttemperatur Tmin.
• Schritt 3: Die optimale spezifische Leistung Heizeinrichtung anliegende (linke) Seite P _op-Li und die optimale spezifische Leistung Heizeinrichtung abliegende (rechte) Seite P _op-Re ergibt sich aus der spezifischen Leistung Heizeinrichtung P an den jeweiligen Backenschienen 7, Zungenschienen 8 bzw. Gleitstuhlplatten 9.
• Schritt 4: Für anliegende (linke) Seite 5 der Weiche 3 und abliegende (rechte) Seite 6 der Weiche 3 wird je ein Weichensegment mit je einem Wärmenetzmodell gebildet, wobei für die anliegende (linke) Seite 5 der Weiche 3 die Zungenschiene 8 bspw. anliegend und für die abliegende (rechte) Seite 6 der Weiche 3 die Zungenschiene 8 abliegend dargestellt ist, und es erfolgt über Berechnung der Verlustleistungen Strahlung P_St , Konvektion P_K , Wärmeleitung P_L , Schmelzwärme P_Sm und Wärmespeicherung P_C bei spezifischer Leistung Heizeinrichtung P die Berechnung der Weichentemperatur T der Weiche 3 zur Zeit t6 der Anheizzeit t_A bei Erreichen der Weichensolltemperatur T_Soll der Weiche 3 und über Berechnung der Erhaltungsleistung zum Zeit t2.1 der Anheizzeit t_A bei Erreichen der Weichenmindesttemperatur Tmin der Weiche 3.
• Schritt 5: Ausgabe der Weichentemperaturen T und der Summe der Verlustleistungen anliegenden (linken) Seite ΣP_V-Li und der Summe der Verlustleistungen abliegende (rechte) Seite ΣP_V-Re
• Schritt 6: Prüfen, ist die berechnete optimale Weichentemperatur T der Weiche 3 am Weichentemperatursensor 28, bspw. an Fuß-Backenschiene anliegende (linke) Seite, anliegend, und abliegende (rechte) Seite 6, größer als die Weichensolltemperatur T_Soll der Weiche 3 unter Berücksichtigung eines Faktors k, bspw. von 1,5? Wenn „JA“ weiter zu Schritt 7., wenn „NEIN“ weiter zu Schritt 13..
• Schritt 7: Prüfen, ist die berechnete optimale Weichentemperatur T der Weiche 3 am Kopf-Zungenschiene anliegend (linke Seite 5) und abliegend (rechte Seite 6) größer oder gleich der Weichenmindesttemperatur der Weiche 3? Wenn „JA“ weiter zu Schritt 8., wenn „NEIN“ weiter zu Schritt 13..
• Schritt 8: Prüfen, ist die berechnete optimale Weichentemperatur T der Weiche 3 an Außen-Gleitstuhlplatte anliegend (linke Seite 5) und abliegend (rechte Seite 6) größer oder gleich der Weichenmindesttemperatur der Weiche 3? Wenn „JA“ weiter zu Schritt 14., wenn „NEIN“ weiter zu Schritt 13..
• Schritt 9: Ermitteln der erforderlichen spezifischen Leistung aus der Summe von Erhaltungsleistung zur Erhaltung der Weichenmindesttemperatur der Weiche 3 an Backenschiene 7 und Schmelzleistung anliegende (linke) Seite P_Sm-Li und Schmelzleistung abliegende (rechte) Seite P_Sm-Li zum Schmelzen der bisher gesamten Schneemenge, die sich aus erfasster Schneemenge pro Zeiteinheit und der Zeit t2.3 der Anheizzeit t_A ergibt.
• Schritt 10: Prüfen, ist die erforderliche spezifische Leistung der anliegenden (linken) Seite P _erf-Li oder die erforderliche spezifische Leistung der abliegenden (rechten) Seite P _erf-Re kleiner gleich der spezifischen Leistung Heizeinrichtung P? Wenn „JA“ weiter zu Schritt 11., wenn „NEIN“ weiter zu Schritt 12..
• Schritt 11: Die gefallene Schneemenge ist kleiner oder gleich der geschmolzenen Schneemenge. Der gefallene Schnee wird während der Anheizzeit geschmolzen.
• Schritt 12: Die gefallene Schneemenge ist größer der geschmolzenen Schneemenge. Der gefallene Schnee wird während der Anheizzeit nicht geschmolzen.
• Schritt 13: Ausgabe Defizit für anliegende und abliegende Seite mit hier nicht näher angeführtem Text.
• Schritt 14: Ausgabe der Betriebsgrenzwerte mit bspw. Minimalwerten aus Weichentemperaturen der Weiche 3 anliegende (linke) Seiten 5 und abliegende (rechte) Seiten 6 Kopf-Backenschienen, Kopf-Zungenschienen sowie geschmolzene Schneemenge.

Below are the steps for evaluating an existing point heater 1 at minimum ambient temperature T _RPM , maximum amount of snow per hour hS and max. Wind speed Vmax shown.

• Step 1: start the program
• step 2nd : Enter the minimum expected ambient temperature T _Umin , specific heating services P , Set point temperature T _target , maximum wind speed Vmax, rail profile R the soft 3rd , maximum amount of snow per hour hs and location of the heating devices 14 on stock rail 7 and / or tongue rail 8th and / or sliding chair plate 9 , Minimum switch temperature Tmin.
• step 3rd : The optimal specific performance heating device adjacent (left) side P _op-Li and the optimal specific performance heater remote (right) side P _op-Re results from the specific performance of the heating device P on the respective stock rails 7 , Tongue rails 8th or sliding chair plates 9 .
• step 4th : For the adjacent (left) side 5 the soft 3rd and remote (right) side 6 the soft 3rd a turnout segment is formed with a heat network model, whereby for the adjacent (left) side 5 the soft 3rd the tongue rail 8th e.g. adjacent and for the remote (right) side 6 the soft 3rd the tongue rail 8th is shown remote, and it is done by calculating the power losses radiation P _St , Convection P _K , Heat conduction P _L , Heat of fusion P _Sm and heat storage P _C with specific power heater P the calculation of the switch temperature T the soft 3rd at time t6 of the heating time t _A when the set point temperature is reached T _target the soft 3rd and about calculating the Maintenance performance at time t2.1 of the heating time t _A when the turnout minimum temperature Tmin is reached 3rd .
• step 5 : Output of turnout temperatures T and the sum of the power losses on the (left) side ΣP _V-Li and the sum of the power losses on the right-hand side ΣP _V-Re
• step 6 : Check, is the calculated optimal switch temperature T the soft 3rd on the switch temperature sensor 28 , for example on the left side of the cheek splint, adjacent, and the far side (right) 6 , greater than the set point temperature T _target the soft 3rd taking into account a factor k , e.g. from 1.5? If "YES" go to step 7 . if "NO" go to step 13 ..
• step 7 : Check, is the calculated optimal switch temperature T the soft 3rd on the head-tongue rail (left side 5 ) and remote (right side 6 ) greater than or equal to the minimum switch temperature 3rd ? If "YES" go to step 8th . if "NO" go to step 13 ..
• step 8th : Check, is the calculated optimal switch temperature T the soft 3rd on the outer sliding chair plate (left side 5 ) and remote (right side 6 ) greater than or equal to the minimum switch temperature 3rd ? If "YES" go to step 14 . if "NO" go to step 13 ..
• step 9 : Determine the specific power required from the sum of the maintenance power to maintain the minimum switch temperature of the switch 3rd on stock rail 7 and melting capacity on the (left) side P _Sm-Li and melting performance on the far right side P _Sm-Li for melting the total amount of snow so far, which results from the amount of snow recorded per unit of time and time t2.3 the heating time t _A results.
• step 10th : Check is the required specific power of the adjacent (left) side P _erf-Li or the required specific power of the remote (right) side P _erf-Re less than or equal to the specific power of the heating device P ? If "YES" go to step 11 . if "NO" go to step 12th ..
• step 11 : The amount of snow fallen is less than or equal to the amount of melted snow. The fallen snow is melted during the heating time.
• step 12th : The amount of snow fallen is larger than the amount of melted snow. The fallen snow is not melted during the heating up period.
• step 13 : Output deficit for adjacent and remote page with text not specified here.
• step 14 : Output of the operating limit values with, for example, minimum values from the switch temperatures of the switch 3rd adjacent (left) pages 5 and remote (right) pages 6 Head stock rails, head tongue rails and melted snow.

• Schritt 1. Eingabe Beispielhaft erfolgt die Eingabe für eine Weiche 3 mit Heizeinrichtung 14 mit spezifischer Leistung P von 330 Watt pro Meter an den Backenschienen 7. Die Weichensolltemperatur der Weiche 3 beträgt 7 °C, die Weichenmindesttemperatur Twmin der Weiche 3 für das Schmelzen von Schnee an der Weiche 3 wird mit +/- 0 °C und einem minimalen Leistungsverhältnis L_v von 40 % parametriert, so dass die optimale spezifische Leistung Pop der Heizeinrichtung 14 mit 330 W/m multipliziert mit 40 % gleich 132 W/m zu Beginn des Betriebes eingestellt wird. Der Standort des Weichentemperatursensor 28 w_T ist bspw. die linke Seite 5 der Weiche 3. Die Betriebsbereichswerte sind vom Betreiber der Weiche 3 mit Schienenprofil R54 für eine Umgebungstemperatur bis - 20 °C bei einer maximalen Windgeschwindigkeit bis 0,8 m/s und einer maximalen Schneemenge bis 5 cm/h festgelegt. Bis zu diesen Betriebswerten soll die Funktion der Weiche 3 durch die erfindungsgemäße Weichenheizung 1 durch Gewährleistung der erforderlichen Weichenmindesttemperatur T _W-min an den funktionsrelevanten Stellen 19 und entsprechender optimaler spezifischer Leistung Pop zum Schmelzen der Schneemenge h_S sichergestellt werden.
• Schritt 2. Wahl des Weichensegments und Berechnen der spezifischen Leistung des Weichensegments linke Seite und rechte Seite mit 330 W/m * 40 % = 132 W/m.
• Schritt 3. Einlesen Weichsegment 1 linke Seite und rechte Seite der aktuellen Umgebungstemperatur, Weichentemperatur, Schneemenge, Niederschlagsart, Niederschlagsmenge und Windgeschwindigkeit.
• Schritt 4. Berechnen der Weichentemperaturen der Weiche 3 und Verlustleistungen im Leistungsgleichgewicht (stationärer Endwert) an 6 Knotenpunkten in dem Wärmenetzmodell 26 für die linke Seite 5 der Weiche 3 und im Wärmenetzmodell 27 der rechten Seite 6 der Weiche 3. Zusätzlich Berechnen der Erhaltungsleistung zum Zeitpunkt t_2.1 . (benötigte Leistung zum Aufrechterhalten der Temperatur von 0 °C).
• Schritt 5. Prüfen, ob Heizanforderung durch Schneefall oder niedrige Umgebungstemperaturen besteht. Wenn Ja weiter mit Schritt 6 wenn nein weiter mit Schritt 2.
• Schritt 6. Prüfen ob die aktuelle Zeit größer als die Totzeit ist. Wenn Ja weiter mit Schritt 7, wenn nein weiter mit Schritt 8
• Schritt 7. Bei abgelaufener Totzeit Messen der Weichentemperatur der Weiche 3 mittels Weichentemperatursensor und Vergleichen mit berechneten Weichentemperatur am jeweiligen Knoten K und Berechnen der Weichenendtemperaturüber Zeitkonstante oder Modellparameter.
• Schritt 8. Prüfen, ob Weichentemperatur der Weiche 3 Kopf-Zungenschiene linke Seite größer als die Weichentemperatur der Weiche 3 Kopf-Zungenschiene rechte Seite ist. Bei „Ja“ ist die linke Seite die anliegende Zungenschiene 8, (Annahme Weichentemperatur Kopf Zungenschiene ist höher, damit wird erkannt, ob die Weiche inzwischen umgestellt wurde).
• Schritt 9. Prüfen, ob linke Seite oder rechte Seite Standort des Weichentemperatursensors ist. Im Beispiel ist die Linke Seite der Standort des Weichentemperatursensor 28. Auf der Seite mit Weichentemperatursensor 28 weiter mit Schritt 10 auf der Seite ohne Weichentemperatursensor weiter mit Schritt 12. Eine Ausrüstung beider Seiten mit Weichentemperatursensoren ist möglich.
• Schritt 10. Zuweisen Weichentemperatur linke Seite ist anliegend und Weichentemperatur rechte Seite ist abliegend
• Schritt 11. Prüfen, ob die errechnete Weichentemperatur der Weiche 3 Fuß-Backenschiene anliegend gleich der realen Weichentemperatur der Weiche 3 Fuß-Backenschiene unter Berücksichtigung einer Weichentemperaturtoleranz ist, wenn „Nein“ weiter zu Schritt 19., wenn „Ja“ weiter zu Schritt 12.
• Schritt 12. Prüfen, ob berechnete Weichentemperatur der Weiche 3 Fuß-Backenschiene größer ist als die Weichensolltemperatur der Weiche 3 zuzüglich einer Konstante und abzüglich der Umgebungstemperatur ist. Wenn „Nein“ erhöhen des Leistungsverhältnisses Lv um den Faktor x (im Beispiel 10%) und weiter zu Schritt 2, wenn „Ja“ weiter zu Schritt 13.
• Schritt 13. Prüfen, ob Erhaltungsleistung zuzüglich derLeistung Schmelzwärme P_Sm kleiner oder gleich der optimalen Leistung zur Zeit t_2.3 ist. Wenn „Nein“ erhöhen des Leistungsverhältnisses Lv um den Faktor x (im Beispiel 10%) und weiter zu Schritt 2, wenn „Ja“ weiter zu Schritt 14.
• Schritt 14. Prüfen, ob die Aufheizzeit des Fuß der Backenschiene t_A-Fu-Ba kleiner oder gleich der maximalen Aufheizzeit t_A-max ist. Wenn „Nein“ erhöhen des Leistungsverhältnisses Lv um den Faktor x (im Beispiel 10%) und weiter zu Schritt 2, wenn „Ja“ weiter zu Schritt 15.
• Schritt 15. Prüfen, ob die Temperatur des Kopfes der Zungenschiene T_Ko-Zu größer oder gleich der minimalen Weichentemperatur T_min ist. Wenn „Nein“ erhöhen der Weichensolltemperatur T_Soll um den Faktor y (im Beispiel 0,5 K) und weiter zu Schritt 2, wenn „Ja“ weiter zu Schritt 16.
• Schritt 16. Prüfen, ob die Temperatur am Fuß der Zungenschiene T_Fu-Zu größer oder gleich der minimalen Weichentemperatur Tmin ist. Wenn „Nein“ erhöhen der Weichensolltemperatur T_Soll um den Faktor y (im Beispiel 0,5 K) und weiter zu Schritt 2, wenn „Ja“ weiter zu Schritt 17.
• Schritt 17. Prüfen, ob die Temperatur in der Mitte des Gleitstuhles T_GL-mi größer oder gleich der minimalen Weichentemperatur T_min ist. Wenn „Nein“ erhöhen der Weichensolltemperatur T_Soll um den Faktor y (im Beispiel 0,5 K) und weiter zu Schritt 2, wenn „Ja“ weiter zu Schritt 18.
• Schritt 18. Prüfen, ob die Temperatur am äußeren Rand des Gleitstuhles T_GL-au größer oder gleich der minimalen Weichentemperatur Tmin ist. Wenn „Nein“ erhöhen der Weichensolltemperatur T_Soll um den Faktor y (im Beispiel 0,5 K) und weiter zu Schritt 2, wenn „Ja“ weiter zu Schritt 20.
• Schritt 19. Korrektur der Berechnung aus Schritt 4 mit Hilfe eines Korrekturfaktors für Anpassung der Konvektionsverluste oder Strahlungsleistung. Ist die errechnete Weichentemperatur der Weiche 3 Fuß-Backenschiene anliegend kleiner als die reale Weichentemperatur der Weiche 3 Fuß-Backenschiene unter Berücksichtigung einer Weichentemperaturtoleranz so wird die Wärmeübergangszahl Konvektion α um den Faktor n (im Beispiel 1) verringert und weiter zu Schritt 4. Ist die errechnete Weichentemperatur der Weiche 3 Fuß-Backenschiene anliegend größer als die reale Weichentemperatur der Weiche 3 Fuß-Backenschiene unter Berücksichtigung einer Weichentemperaturtoleranz so wird die Windgeschwindigkeit V um den Faktor n (im Beispiel 1) erhöht und weiter zu Schritt 4.
• Schritt 20. Ausgabe der optimalen Leistung P_op-Li für die linke Seite der Weiche 3 und der optimalen Leistung P_op-Re für die Rechte Seite der Weiche 3 für die folgende Zykluszeit t_z .

The same program can be integrated into the open-loop and closed-loop control by reading the current ambient temperature, wind speed and amount of snow instead of minimum or maximum values and activating suitable corrective measures or warning messages. A suitable correction is, for example, additional heating devices on the sliding chair plates 9 or tongue rails 8th to arrange and to activate the heating devices on these first, so that the possible problems are solved due to the small mass. In 7 is the program flow chart for the control and regulation of a point heater according to the invention 1 for a switch 3rd with rail profile R54 by calculating and evaluating the course over time of the turnout temperatures of the turnout 3rd , the turnout end temperature of the turnout 3rd and the heating time t _A in the places relevant for winter in ice and snow 19th a turnout segment with a specific length I _seg for a left side and a right side at an unspecified point of the switch 3rd correspond. In the 7 illustrated nodes K correspond to those in 1 shown assessment point foot-stock rail 37 , Evaluation point head-tongue rail 41 , Evaluation point foot-tongue rails 40 , Evaluation point middle sliding chair plate 42 and evaluation point outer sliding chair plate 43 for the left side 5 the soft 3rd and the right side 6 the soft 3rd over the length of the turnout 3rd through switch areas 4th Turnout tip 16 , Switch center 17th and point end 18th are characterized, each turnout area by a turnout segment left side 5 the soft 3rd and an opposite switch segment on the right side 6 the soft 3rd is represented. The division of the switch 3rd in left side 5 and right side 6 takes place, for example, from the turnout tip 16 towards the end of the switch 18th .

• step 1 . Entry The example is for a turnout 3rd with heating device 14 with specific performance P of 330 watts per meter on the stock rails 7 . The set point temperature of the turnout 3rd is 7 ° C, the minimum switch temperature Twmin of the switch 3rd for melting snow on the switch 3rd with +/- 0 ° C and a minimal power ratio L _v parameterized by 40% so that the optimal specific power pop of the heater 14 with 330 W / m multiplied by 40% equal to 132 W / m at the start of operation. The location of the switch temperature sensor 28 w _T is for example the left side 5 the soft 3rd . The operating range values are from the switch operator 3rd with rail profile R54 for an ambient temperature down to - 20 ° C with a maximum wind speed of up to 0.8 m / s and a maximum amount of snow of up to 5 cm / h. The function of the switch should be up to these operating values 3rd by the point heater according to the invention 1 by ensuring the required minimum switch temperature T _W-min at the functionally relevant points 19th and corresponding optimal specific performance Pop for melting the amount of snow h _p be ensured.
• step 2nd . Select the turnout segment and calculate the specific power of the turnout segment left and right side with 330 W / m * 40% = 132 W / m.
• step 3rd . Read soft segment 1 left side and right side of the current ambient temperature, switch temperature, amount of snow, type of precipitation, amount of precipitation and wind speed.
• step 4th . Calculate the turnout temperatures of the turnout 3rd and power losses in the power balance (stationary end value) at 6 nodes in the heat network model 26 for the left side 5 the soft 3rd and in the heating network model 27 the right side 6 the soft 3rd . In addition, calculate the maintenance performance at the time t _2.1 . (Power required to maintain the temperature at 0 ° C).
• step 5 . Check whether there is a heating requirement due to snow or low ambient temperatures. If yes, continue with step 6 if no continue with step 2nd .
• step 6 . Check whether the current time is greater than the dead time. If yes, continue with step 7 if no go to step 8
• step 7 . When the dead time has elapsed, measure the turnout temperature of the turnout 3rd using a switch temperature sensor and comparing the calculated switch temperature at the respective node K and calculating the turnout end temperature using time constant or model parameters.
• step 8th . Check whether the turnout temperature of the turnout 3rd Head-tongue rail left side greater than the turnout temperature of the turnout 3rd Head-tongue rail is right side. If "yes", the left side is the adjacent tongue rail 8th , (Assumption switch point head tongue rail is higher, so it is recognized whether the switch has been changed in the meantime).
• step 9 . Check whether the left side or right side is the location of the turnout temperature sensor. In the example, the left side is the location of the switch temperature sensor 28 . On the side with switch temperature sensor 28 continue with step 10th on the side without switch temperature sensor continue with step 12th . Both sides can be equipped with switch temperature sensors.
• step 10th . Assign turnout temperature on left side and turnout temperature on right side is off
• step 11 . Check whether the calculated turnout temperature of the turnout 3rd Foot-to-side splint adjacent to the real turnout temperature of the turnout 3rd Foot stock rail taking into account a switch temperature tolerance is if "No" continue to step 19th if yes go to step 12th .
• step 12th . Check whether the calculated turnout temperature of the turnout 3rd Foot-stock rail is greater than the set point temperature of the turnout 3rd plus a constant and minus the ambient temperature. If "No" increase the performance ratio Lv by the factor x (10% in the example) and go to step 2nd if "yes" go to step 13 .
• step 13 . Check whether maintenance performance plus the heat of fusion P _Sm less than or equal to the optimal performance at the time t _2.3 is. If "No" increase the performance ratio Lv by the factor x (10% in the example) and go to step 2nd if "yes" go to step 14 .
• step 14 . Check whether the heating time of the foot of the stock rail t _A-Fu-Ba less than or equal to the maximum heating time t _A-max is. If "No" increase the performance ratio Lv by the factor x (10% in the example) and go to step 2nd if "yes" go to step 15 .
• step 15 . Check that the temperature of the head of the tongue splint T _Ko-Zu greater than or equal to the minimum switch temperature T _min is. If "No" increase the set point temperature T _target by the factor y (in the example 0.5 K) and on to step 2nd if "yes" go to step 16 .
• step 16 . Check that the temperature at the foot of the tongue rail T _Fu-Zu is greater than or equal to the minimum switch temperature Tmin. If "No" increase the set point temperature T _target by the factor y (0.5 K in the example) and go to step 2nd if "yes" go to step 17th .
• step 17th . Check that the temperature is in the middle of the glider T _GL-mi greater than or equal to the minimum switch temperature T _min is. If "No" increase the set point temperature T _target by the factor y (0.5 K in the example) and go to step 2nd if "yes" go to step 18th .
• step 18th . Check that the temperature is on the outer edge of the glider T _GL-au is greater than or equal to the minimum switch temperature Tmin. If "No" increase the set point temperature T _target by the factor y (0.5 K in the example) and go to step 2nd if "yes" go to step 20th .
• step 19th . Correction of the calculation from step 4th with the help of a correction factor for adaptation of the convection losses or radiation power. Is the calculated turnout temperature of the turnout 3rd Foot-to-side splint fits lower than the real turnout temperature of the turnout 3rd Foot stock rail taking into account a switch temperature tolerance so the heat transfer coefficient becomes convection α reduced by the factor n (in example 1) and continue to step 4th . Is the calculated turnout temperature of the turnout 3rd Foot-to-side splint fits higher than the actual turnout temperature of the turnout 3rd Foot stock rail taking into account a switch temperature tolerance so the wind speed V increased by a factor of n (in example 1) and on to step 4th .
• step 20th . Output of optimal performance P _op-Li for the left side of the switch 3rd and optimal performance P _op-Re for the right side of the switch 3rd for the following cycle time t _z .

In summary, it should be noted that the present invention specifies a method in which the heat network model according to the invention, by comparing the calculated switch temperatures with parameterized minimum switch temperatures, the desired switch temperature and / or the specific output of at least one heating device 14 changed.

Furthermore, the heat network model according to the invention verifies by comparison with a switch temperature sensor 28 detected switch temperatures by correcting the power convection and / or the power radiation the calculated switch temperatures.

The heat network model according to the invention also generates a warning message in the control device before the operating limit for a control system is exceeded and on site.

Finally, the heating network according to the invention determines the heating-up time before and during operation and activates an additional heating regime preheating via the control unit if, depending on the predicted environmental conditions via weather service, the maximum amount of snow is exceeded during the heating-up time and / or the amount of snow is not melted.

Reference list

1

Switch heating

2nd

Viewing direction switch

3rd

Switch

4th

Switch area

5

left side

6

right side

7

Stock rail

8th

Tongue splint

9

Sliding chair plate

10th

adjacent tongue rail

11

remote tongue rail

12th

adjacent area

13

Support lugs

14

Heating device

16

Turnout tip

17th

Switch center

18th

Switch end

19th

Functionally relevant position

20th

Head-stock rail

21

Head-tongue splint

22

Middle sliding chair plate

23

Outside sliding chair plate

24th

threshold

25th

Threshold distance

26

Left side heating network

27

Right side heating network

28

Turnout temperature sensor

29

Heating device symbol

30th

Heat radiation symbol

31

Convection icon

32

Heat storage symbol

33

Heat conduction symbol

34

Turnout segment turnout tip

35

Switch segment switch center

36

Switch segment switch end

37

Evaluation point foot-splint

38

Assessment point web-splint

39

Assessment point head-stock rail

40

Evaluation point foot-tongue rail

41

Evaluation point head-tongue rail

42

Assessment point middle sliding chair plate

43

Evaluation point outdoor sliding chair plate

P _St

Radiant heat output

P _L

Performance heat conduction

P _K

Power convection heat

P _op

optimal specific performance

P

real specific power heater

P _erf

required specific performance

ξ _L

Correction factor length

P _C

Performance heat capacity

P _V

Evaporative heat output

P _Sm

Heat output

P _Erh

Maintenance performance

R

Switch profile

T _U

Ambient temperature

T _RPM

minimum ambient temperature

T _W

real switch temperature

ΔT _W

real switch temperature difference

T _min

Switch minimum temperature

T _op

optimal switch temperature

T _target

Turnout target temperature

T _{target forward}

second set point temperature

T _S

Melting temperature

T _V

Evaporation temperature

T _K

Turnout temperature cold rail

NI

Type of precipitation

L _v

Performance ratio

L _sp

specific length heater

K

Knot ( K )

IN

Heating current

t _A

Heating time

t _E

On time

t _z

Time cycle

k

factor

α

Heat transfer coefficient convection

K _Fu-Ba-Li

Knoten (K) Fuß-Backenschiene-linke Seite

K _Ko-Ba-an

Knoten (K) Kopf-Backenschiene-anliegende Zungenschiene

T_Ko-Ba

Weichentemperatur - Kopf-Backenschiene

T_Ko-Ba-Li

Weichentemperatur-kopf-Backenschiene Linke Seite der Weiche

T_Ko-Zu

Weichentemperatur - Kopf-Zungenschiene

T_Gl-mi

Weichentemperatur - Mitte-Gleitstuhlplatte

T_GL-au

Weichentemperatur - Außen-Gleitstuhlplatte

t_T

Totzeit

t_A

Anheizzeit

t_max

maximale Anheizzeit

h_s

Schneemenge pro Stunde

v

Windgeschwindigkeit

v_max

maximale Windgeschwindigkeit

n

Zyklusfaktor

t_n

Zeit

t_z

Zykluszeit

y

Weichensolltemperatur-Korrekturfaktor

w_T

Standort Weichentemperatursensor

Examples for designation of nodes (K) and temperatures

K _Fu-Ba-Li

Knot ( K ) Foot-splint-left side

K _Ko-Ba-an

Knot ( K ) Head-cheek splint-fitting tongue splint

T _Ko-Ba

Turnout temperature - head-stock rail

T _Ko-Ba-Li

Switch temperature head stock rail Left side of the switch

T _Ko-Zu

Turnout temperature - head-tongue rail

T _Gl-mi

Turnout temperature - middle sliding chair plate

T _GL-au

Turnout temperature - outside sliding chair plate

t _T

Dead time

t _A

Heating time

t _max

maximum heating time

h _s

Amount of snow per hour

v

Wind speed

v _max

maximum wind speed

n

Cycle factor

t _n

time

t _z

Cycle time

y

Turnout target temperature correction factor

w _T

Turnout temperature sensor location

an

anliegend

ab

abliegend

Re

rechte Seite

Li

linke Seite

Ba

Backenschiene

Zu

Zungenschiene

GL

Gleitstuhlplatte

Ko

Kopf

Fu

Fuß

St

Schienensteg

au

außen

mi

mitte

op

optimal

w

real

Indices:

on

fitting

from

remote

re

right side

Li

left side

Ba

Stock rail

To

Tongue splint

GL

Sliding chair plate

Knockout

head

Fu

foot

St

Rail web

au

Outside

mi

center

op

optimal

w

real

1. [1] Löbl. H.: Strombelastbarkeit des Transformators in einer Kompaktstation Elektrizitätswirtschaft, H. 17/18 96. S. 1154-1163 ,
2. [2] Q uelle 2 Elsner, N.: Grundlagen der Technischen Thermodynamik, Berlin: Akademie Verl. 1988 ,
3. [3] Bömer,H.; Über den Wärme- und Stoffübergang an umspülten Einzelkörpern bei Überlagerung von freier und erzwungener Konvektion, Düsseldorf: VDI-Verl. 1965 (VDI-Forschungsheft 512) ,
4. [4] Krischer, 0.: Die wissenschaftlichen Grundlagen der Trocknungstechnik, Berlin: Springer Verl. 1956 ,
5. [5] Philippow, E.: Taschenbuch Elektrotechnik Bd. 5: Elemente und Baugruppen der Elektroenergietechnik, Berlin: Verl. Technik 1979 ,
6. [6] Gremmel, H.: Schaltanlagen, Hrsg. ABB Schaltanlagen GmbH Mannheim, Düsseldorf: Comelsen Verl. Schwann-Girardet 1992 .

literature

1. [1] Löbl. H .: Current carrying capacity of the transformer in a compact station Elektrizitätswirtschaft, H. 17/18 96. S. 1154-1163 ,
2. [2] Q uelle 2 Elsner, N .: Fundamentals of Technical Thermodynamics, Berlin: Akademie Verl. 1988 ,
3. [3] Bömer, H .; About the heat and mass transfer on washed-over individual bodies with the overlay of free and forced convection, Düsseldorf: VDI-Verl. 1965 (VDI research booklet 512) ,
4. [4] Krischer, 0 .: The scientific foundations of drying technology, Berlin: Springer Verl. 1956 ,
5. [5] Philippow, E .: Taschenbuch Elektrotechnik Bd. 5: Elements and Assemblies of Elektroenergietechnik, Berlin: Verl. Technik 1979 ,
6. [6] Gremmel, H .: Switchgear, ed. ABB Schaltanlagen GmbH Mannheim, Düsseldorf: Comelsen Verl. Schwann-Girardet 1992 .

QUOTES INCLUDE IN THE DESCRIPTION

This list of documents listed by the applicant has been generated automatically and is only included for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Non-patent literature cited

• Löbl. H .: Current carrying capacity of the transformer in a compact station Elektrizitätswirtschaft, H. 17/18 96. S. 1154-1163 [0100]
• uelle 2 Elsner, N .: Fundamentals of Technical Thermodynamics, Berlin: Akademie Verl. 1988 [0100]
• Bömer, H .; About the heat and mass transfer on washed-over individual bodies with the overlay of free and forced convection, Düsseldorf: VDI-Verl. 1965 (VDI research booklet 512) [0100]
• Krischer, 0 .: The scientific foundations of drying technology, Berlin: Springer Verl. 1956 [0100]
• Philippow, E .: Taschenbuch Elektrotechnik Bd. 5: Elements and Assemblies of Elektroenergietechnik, Berlin: Verl. Technik 1979 [0100]
• Gremmel, H .: Switchgear, ed. ABB Schaltanlagen GmbH Mannheim, Düsseldorf: Comelsen Verl. Schwann-Girardet 1992 [0100]

Claims (11)

Method for controlling and regulating a point heater (1), the point heater (1) comprising at least one heating device (14) arranged on at least one point (3), at least one point temperature sensor (28) on the at least one point (3), at least one energy distribution With at least one heating outlet per switch (3) and at least one control device for controlling and regulating the switch temperature, comprising the steps: a) Defining at least one switch segment for the left side (5) of the at least one switch (3) and / or for the right side (6) of the at least one switch (3) with a specific length, the switch segment of the at least one switch (3) comprising a stock rail (7), a tongue rail (8), a sliding chair plate (9) and at least one heating device (14 ), and breaking down the at least one turnout segment into individual sections, each with at least one first node, the at least one functionally relevant point (19) of the white of the at least one switch (3) in winter, the functionally relevant point (19) having at least one evaluation point (37, 38, 39, 40, 41, 42, 43), the at least one switch segment representing the at least one switch ( 3) depicts thermodynamically, the at least one switch segment being arranged in the vicinity of the at least one switch temperature sensor (15, 18), b) forming a heat network (26, 27) for the at least one switch segment for the left side (5) of the at least one Switch (3) and / or for the right side (6) of the at least one switch (3), the heat network (26, 27) having heat generating elements, heat transfer elements and heat storage (32), and assigning the at least first node (K) in each case of the respective sections of the at least one turnout segment to at least one evaluation point (37, 38, 39, 40, 41, 42, 43), all nodes (K) of the individual sections via meshes to the heating network (26, 27) be connected in such a way that the difference between all signed temperatures is zero, c) calculating the time profile of an optimal specific power (P _op ) of the at least one switch segment and the respective optimal switch temperature at the at least one first node of the switch heater (1) at the at least one turnout segment via a power balance according to a set of nodes, and during operation activating this optimal specific power at the associated heating device (14) by means of a product of the real specific power of the heating device (14), which corresponds to the maximum specific power, and a power ratio, the Power ratio variable between 25% and 100% of the real specific power, d) detecting the time profile of the real turnout temperature on the at least one turnout segment with the at least one turnout temperature sensor (28) and correcting the calculated turnout temperature one of the at least first nodes of the at least one turnout segment via the power of convection heat if the calculated turnout temperature is greater than the real turnout temperature or the radiant heat output of the heating network if the calculated turnout temperature is less than the real turnout temperature, e) calculating the turnout temperature at at least a second node of the at least one turnout segment and comparing the calculated turnout end temperature with a parameterized minimum turnout temperature for this at least one second node, wherein if the minimum turnout temperature of the turnout (3) is not reached, a parameterizable turnout target temperature is increased by a turnout target temperature correction factor until the respective calculated turnout end temperature of the turnout (3) at least the minimum turnout temperature corresponds to the switch (3), f) calculating the heating time for heating the at least one switch segment up to the parameterizable switch setpoint temperature structure of the turnout (3) and evaluation of the calculated heating-up time at a configurable turnout setpoint temperature, whereby the optimal specific power is increased in the case of a deficit and the optimum specific power is reduced in the case of an excess the parameterizable minimum switch temperature of the switch (3) and evaluation of the required specific performance from maintenance performance and melting performance for the snow that has been dropped up to that point with the specific power (P) at parameterizable minimum switch temperature, whereby if there is a deficit, the optimal specific performance increases or a message “fallen amount of snow is too big and will not be melted ”. Procedure according to Claim 1 , further comprising the step h) before operation by a heating request, calculating the specific melting power for the amount of snow calculated during the heating time on the turnout segment from a reported snow depth per unit of time and calculating the specific maintenance output for maintaining the melting temperature at the turnout segment and comparing the sum of these with the real specific power of the heating device (14) and, if the real specific power of the heating device (14) is lower, activating the point heater (1) with a second set point temperature which is so high that the specific power of the heating device (14) during operation is at least equal to the sum of the specific melting performance and the maintenance performance. Procedure according to Claim 1 or 2nd , wherein the heat generating elements comprise the specific power of the at least one heating device (29) with a heat accumulator of the switch segment and heat transfer by heat radiation and / or the heat transfer elements heat resistances on the switch (3) from the material properties, the geometric sizes and the prevailing loads due to heat transfer and environment on the at least one switch segment. Procedure according to one of the Claims 1 to 3rd , wherein in step f) the heating-up time for heating the at least one turnout segment is calculated from the sum of individual heating times for the at least one turnout segment for heating it up, for melting snow and for evaporating water thereon, and / or the heating-up time is increased by increasing the power ratio and / or switching from control mode to continuous operation and / or is reduced by reducing the power ratio. Procedure according to one of the Claims 1 to 4th , with active heating further comprising the steps i) calculating a melting capacity for fallen snow in a parameterizable period of time and comparing this melting capacity with the difference between the specific capacity and a calculated maintenance capacity, with a deficit in the specific capacity increasing the capacity and / or continuous heating started and / or a first warning message is output, and / or j) comparing the calculated heating time with a parameterized maximum heating time, the output being increased and / or continuous heating being started and / or a second warning message being output if the specific power is deficient, and / or k) calculating the snow depth from the difference between the fallen snow depth and the melted snow depth per unit of time and comparing the calculated snow depth with a parameterizable maximum permissible snow depth, with a deficit in the specific power increasing the power and / or a down heating started and / or a third warning message is issued. Procedure according to one of the Claims 1 to 5 , wherein the calculation of the heating time in step f) comprises the sub-steps: f1) calculation of the dead time for the at least one switch segment from the course over time of the switch temperature of the switch (3) with optimal or real specific power, f2) calculation of the time t _A1 for Heating the at least one switch segment from the switch temperature of the cold rail of the switch (3) and the melting temperature to the minimum switch temperature at at least one node, f3) calculating the time t _A2 for melting the amount of snow during step f2) from the difference from the existing specific power minus the power to maintain the minimum switch temperature of the at least one turnout segment, f4) calculating the time t _A3 for melting the fallen snow during step f3) from the difference from the existing specific power minus the power to maintain the minimum switch temperature of the at least one turnout segment, f5) Calculate the time t _A4 for heating the at least one turnout segment from the difference between the minimum switch temperature and the desired setpoint temperature at the nodes with the turnout temperature sensor of the turnout (3), f6) calculating the time t _A5 for melting the fallen snow during step f5) from the difference from the existing specific power minus the performance to maintain the minimum switch temperature of the at least one switch segment. Procedure according to one of the Claims 1 to 6 , further comprising a determination of the operating limit ambient temperature (G _W-Tu ) of the point heater (1), comprising - calculating the optional point end temperatures at two specific nodes of the at least one point segment, which the head-cheek rail (20) and the head-tongue rail (21 ) correspond to the functionally relevant points (19) of the at least one switch (3), the calculated switch temperatures head-to-head rail and head-tongue rail being subtracted from the minimum switch temperature and the lowest of which corresponds to the operating limit ambient temperature. Procedure according to one of the Claims 1 to 7 , further comprising a determination of the operating limit of the amount of snow (G _W-hs ) of the point heater (1), comprising - calculating a specific maintenance performance at the minimum point temperature Tmin of the point (3) plus a minimum point temperature (T _W-min ) tolerance ΔT _min at the stock rail foot , a melting capacity for the maximum amount of snow or the amount of snow recorded up to that point, and an evaporation capacity for melting water, and comparison of the sum thereof with the required specific capacity of the heating device (29) of the at least one switch segment, if the required specific capacity of the Heating device is smaller than the sum of the maintenance capacity and melting capacity and evaporation capacity the operating limit snow depth has been exceeded. Procedure according to one of the Claims 1 to 8th , further comprising a project-specific dimensioning of the heating devices (29) and their required specific power, comprising - calculating a specific power (P) of the heating device to achieve a setpoint switch temperature of the switch (3) at the location of the switch temperature sensor and a minimum switch temperature T _w-min der Switch (3) on at least one head-stock rail (20) and / or one head-tongue rail (21) for the at least one switch segment by calculating the sum of heat conduction, radiation and convection into the environment, heat capacity and latent heat in snow and rain , with existing operating limit values from minimum ambient temperature, rail profile, maximum wind speed and maximum snow depth per hour, and - increasing the specific output if the calculated real specific output is less than the specific output, the required melting output in the heating up time from the minimum ambient temperature until a rail temperature of at least 0 ° C is reached, for the amount of snow, which results from the product of heating time and snow depth per hour, and the evaporation capacity of the remaining melt water and the required specific maintenance capacity for a rail temperature of 0 ° C at the functionally relevant points of the at least one turnout segment. Procedure according to one of the Claims 1 to 9 , wherein - during operation of the point heating system (1), setting the optimum specific power for the heating devices (29), which corresponds to the product of specific power and a power ratio of 25% to 100%, via the respective switching devices for switching the heating devices on and off (29) by changing the duty cycle or the frequency or the pulse width or wave packet control or group operation, and / or - the power ratio is between 25% and 100%, the specific power P on the left-hand side (5 ) the switch (3) and the right side (6) of the switch (3) corresponds at most to the mean and / or meridian of the specific power of the heating device (29), and / or - when the switch heating system (1) is operating, the calculated specific power P _op for the left side (5) of the switch (3) and the right side (6) of the switch (3) maximum of the specific power (P ) corresponds to the heating devices (29), or a specific power difference for the left side (5) of the switch (3) or the right side (6) of the switch (3) from the difference of specific power (P) of the heating devices (14) minus the calculated specific power (P _op ) is calculated and if there is a positive specific power difference on the left side (5) of the switch (3) or the right side (6) of the switch (3), this specific power difference on the other side of the switch (3) In addition to the specific power (P) of the heating device (14) is made available, so that a uniform time course of the rail temperatures of the switch (3) on the left side (5) of the switch (3) and on the right side (6) the switch (3) takes place at the functionally relevant points of the switch (3). Device for controlling and regulating a point heating system (1), the point heating system (1) comprising at least one heating device (14) arranged on at least one point (3), at least one point temperature sensor (28) on the at least one point (3), at least one energy distribution With at least one heating outlet per switch (3) and at least one control device for controlling and regulating the switch temperature, comprising: a CPU for calculating the switch temperatures of the switch (3) for at least one switch segment, which is connected to the control device via communication means, - - At least one junction box located away from the switch (3), which has at least one switching device that is connected via lines to the heating devices (29) of the switch (3), as well as measuring means for the temporal recording of operating current, voltage and insulation resistance and means for Has maximum power limitation, at least one communication means, which is arranged in the connection box and connected to the control unit, - At least one precipitation sensor for detecting the type and amount of precipitation, which is connected to the control unit.

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