Railway steel rail heating device
By using an electrothermal film device that heats railway rails with low voltage and high current, combined with temperature sensors and control circuits, the problems of uneven heating and cumbersome operation of railway rails have been solved. This device achieves uniform heating and localized control, reducing equipment costs and improving construction efficiency.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-12-27
- Publication Date
- 2026-03-03
AI Technical Summary
Existing railway rail heating methods suffer from problems such as uneven overall heating, cumbersome operation, high cost, and easy damage to the electromagnetic head, and it is difficult to achieve localized heating.
The railway rails are heated by an electric heating film using a low-voltage, high-current method. The electric heating film is covered on the rails, and the current and temperature are adjusted in real time by temperature sensors and control circuits to achieve uniform heating and local control.
It achieves uniform heating of railway rails, simplifies the operation process, reduces equipment costs, improves heating efficiency and safety, and is suitable for different construction environments.
Smart Images
Figure CN223963775U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to heating control, and in particular to a railway rail heating device. Background Technology
[0002] In natural environments, temperature changes can cause thermal stress within the rails. Excessive thermal stress can lead to rail expansion and cracking, affecting the rail's service life and operational safety. Therefore, during rail replacement work, maintenance personnel generally maintain the rail temperature at around the annual average temperature. In cold winter regions such as Northeast my country, Tibet, and northern Xinjiang, the ambient temperature may not meet the rail temperature requirements for rail replacement for extended periods throughout the year. Therefore, rail heating is necessary before replacement. Currently, there are several methods for rail heating: Internationally, a mixed gas flame heating method is commonly used, where a flame gun is used to directly spray flames onto the rail surface to raise its temperature. This method is simple and easy to operate, but it can cause significant damage to the rail surface and lead to uneven internal stress. Domestically, the stretching machine method and the heat transfer method are commonly used. The stretching machine operates a hydraulic pump station to drive the stretching rod to stretch the rail, changing the rail's thermal stress. This method offers advantages such as accurate rail temperature control and less susceptibility to environmental conditions, but it has disadvantages such as relatively complex operation procedures, longer construction time, and uneven internal stress distribution in the rail. The heat conduction method involves attaching thermal resistance wires to the surface of the rail, heating it through heat conduction. However, this method suffers from low heat conduction efficiency and uneven temperature distribution. In recent years, electromagnetic induction heating has emerged. This method uses an electromagnetic device to generate alternating magnetic flux, inducing an electromotive force within the rail, which in turn generates eddy currents that heat the rail. While this method offers high heat conversion efficiency, it suffers from high cost, susceptibility to damage to the electromagnetic head, limited heating distance, and inconvenient operation, thus limiting its widespread practical application. Summary of the Invention
[0003] One of the purposes of this utility model is to provide a railway rail heating device to solve problems such as uneven heating of railway rails or cumbersome operation in existing heating methods.
[0004] The second objective of this utility model is to provide a railway rail heating device so as to facilitate local heating of railway rails.
[0005] The purpose of this utility model is achieved by relating to a railway rail heating device, characterized by...
[0006] The system comprises a power supply, a control circuit, and an electric heating film. The electric heating film is fixed to both sides of the railway rail by a mounting bracket. The electric heating film is electrically connected to the power supply through the control circuit. The control circuit includes at least a temperature sensor, a current transformer, and an input / output interface circuit. Commands are input to the control circuit through the input / output interface circuit. After receiving the command to heat the railway rail, the control circuit turns on the control switch, connecting the power supply and the electric heating film. Heating is then applied to both sides of the railway rail through the electric heating film. The control circuit detects the temperature of the temperature sensor and the current of the current transformer, ensuring that the current flowing to the electric heating film and the detected temperature are within a set range. When the railway rail needs to be heated, AC power is input to the electric heating film to form a circuit, applying a large current to the electric heating film to generate heat. The electric heating film covers the railway rail to be heated. After the target temperature is set in the temperature control unit, the actual temperature is compared in real time. When the surface temperature of the heated rail reaches the set target temperature, the system automatically stops working.
[0007] The temperature sensor is a thermocouple, which is distributed on both sides of the railway rail and is wrapped by an electric heating film and the railway rail.
[0008] The aforementioned fixing frame is a chrome alloy elastic frame.
[0009] The aforementioned fixing frame is a stainless steel elastic frame.
[0010] The switch is a bidirectional thyristor, and the heating temperature is adjusted by the duty cycle of the bidirectional thyristor.
[0011] It also includes a residual current device (RCD) that is electrically connected to the railway rails and the grounding wire.
[0012] The control circuit is powered by a DC power supply, which is supplied with a 5V voltage by a switching power supply.
[0013] The power source is either a low-voltage power source provided by an AC power source via a switching power supply.
[0014] The advantages of this utility model are:
[0015] This utility model discloses a railway rail heating device that uses a low-voltage, high-current method to heat an electric heating film. The heating film covers the railway rail to be heated, thus solving the problems of uneven heating or cumbersome operation in existing heating methods. This heating device is easy to operate, has a simple heating circuit, and low equipment cost. The input power supply, heating film, and wires are easy to disassemble and transport.
[0016] This invention relates to a heating device consisting of an input power supply (AC power), a rectifier module, a filter module, a control module, and an electric heating film assembly forming a loop. A common AC power supply provides AC power to the rectifier module, and the output DC power is filtered by the filter module to supply the heating film for heating. The heating film covers the railway rail to be heated. The use of low voltage and high current ensures the electrical safety of on-site construction personnel.
[0017] This invention employs an indirect heating device for railway rails. Railway rails have a certain internal resistance, and the rails are used as the heating element. A large current is applied to the heating film, utilizing the heat-applying effect to raise the temperature of the rails, shortening the heating time and reducing damage to the rail body. A temperature control unit in the control module collects the temperature of the rails during the heating process in real time, allowing on-site personnel to monitor the real-time temperature of the heated rails. After setting a target temperature in the temperature control unit, the actual temperature is compared in real time. When the surface temperature of the heated rail reaches the set target temperature, the rectifier module automatically stops working; when the surface temperature of the heated rail has not reached the set target temperature, the rectifier module continues heating, thus achieving temperature comparison and operational feedback.
[0018] The present invention will be further described below with reference to the accompanying drawings of the embodiments. Attached Figure Description
[0019] Figure 1 This is a schematic diagram illustrating the principle of heating railway rails according to this utility model;
[0020] Figure 2 This is a schematic diagram of the railway rail heating temperature control unit implemented in this utility model. Detailed Implementation
[0021] The following will describe in detail the implementation of this utility model with reference to the accompanying drawings and embodiments, so as to fully understand how this utility model uses technical means to solve technical problems and achieve technical effects and to implement it accordingly. Example 1
[0022] like Figure 1As shown, this utility model relates to a railway rail heating device, characterized by: a power supply 1, a control circuit 2, and an electric heating film 3. The electric heating film 3 is fixed to both sides of the railway rail 5 by a fixing frame 4. The electric heating film 3 is electrically connected to the power supply 1 through the control circuit 2. The control circuit 2 includes at least a temperature sensor 6, a current transformer 7, and an input / output interface circuit 8, all electrically connected. Commands are input to the control circuit 2 through the input / output interface circuit 8. After receiving the command to heat the railway rail 5, the control circuit 2 activates a control switch 9, connecting the power supply 1 and the electric heating film 3. Heating is then applied to both sides of the railway rail 5 through the electric heating film 3. The control circuit 2 detects the temperature of the temperature sensor 6 and the current of the current transformer 7, ensuring that the current flowing to the electric heating film 3 and the detected temperature are within a set range. The temperature sensor 6 is a thermocouple, distributed on both sides of the railway rail 5 and enclosed by the electric heating film 3 and the railway rail 5. The fixing frame 4 is a chromatic alloy elastic frame. The switch 9 is a bidirectional thyristor, which adjusts the heating temperature by adjusting the duty cycle of the bidirectional thyristor; it includes at least one leakage current protection device 10, which is electrically connected to the railway rail 5 and the grounding connection line. When there is leakage current between the railway rail 5 and the grounding connection line, the electrical circuit between the power supply 1 and the heating film 3 is disconnected. Example 2
[0023] like Figure 2 As shown, this utility model relates to a railway rail heating device, characterized by: a power supply 1, a control circuit 2, and an electric heating film 3. The electric heating film 3 is fixed to both sides of the railway rail 5 by a fixing frame 4. The electric heating film 3 is electrically connected to the power supply 1 through the control circuit 2. The control circuit 2 includes at least a temperature sensor 6, a current transformer 7, and an input / output interface circuit 8, all electrically connected. Commands are input to the control circuit 2 through the input / output interface circuit 8. After receiving the command to heat the railway rail 5, the control circuit 2 activates a control switch 9, connecting the power supply 1 and the electric heating film 3. Heating is then applied to both sides of the railway rail 5 through the electric heating film 3. The control circuit 2 detects the temperature of the temperature sensor 6 and the current of the current transformer 7, ensuring that the current flowing to the electric heating film 3 and the detected temperature are within a set range. The temperature sensor 6 is a thermocouple, distributed on both sides of the railway rail 5 and enclosed by the electric heating film 3 and the railway rail 5. The fixing frame 4 is a chromatic alloy elastic frame. Switch 9 is a bidirectional thyristor, and the heating temperature is adjusted by the duty cycle of the bidirectional thyristor; control circuit 2 is supplied by DC power supply 11, which is supplied with a 5V voltage via power supply 1 from a switching power supply. Power supply 1 can also be a low-voltage power supply provided by AC power supply via a switching power supply. Example 3
[0024] Unlike Examples 1 and 2, the fixture 4 in Example 3 is a stainless steel elastic fixture.
[0025] To ensure a stable, continuous, and adjustable low-voltage, high-current output for heating railway rails, the duty cycle needs to be adjusted using the PWM control principle.
[0026] The hardware control unit itself forms a closed-loop control circuit to regulate the voltage and keep it constant within a certain accuracy range.
[0027] The design of the railway rail heating system described in this utility model is based on the following formula:
[0028] Set the total energy Q of the railway rail
[0029] Q=C∙M∙L∙T_∆
[0030] Where: C is the specific heat capacity of the railway rail, M is the weight of the railway rail, L is the length of the railway rail, and T_∆ is the temperature difference of the railway rail.
[0031] The equivalent resistance R of railway rails
[0032] R = L / (πr^2 σ)
[0033] Where: r is the equivalent radius of the railway rail, and is the electrical conductivity of the railway rail.
[0034] Rail heating circuit current I
[0035] I = √(Q / Rt)
[0036] Where: t is the heating time of the railway rail, and R is the resistance of the railway rail.
[0037] Total energy Q of railway rails
[0038] Q=C∙M∙L∙T_∆
[0039] Where: C is the specific heat capacity of the railway rail, M is the weight of the railway rail, L is the length of the railway rail, and T_∆ is the temperature difference of the railway rail.
[0040] The equivalent resistance R of railway rails
[0041] R = L / (πr^2 σ)
[0042] Where: r is the equivalent radius of the railway rail, and is the electrical conductivity of the railway rail.
[0043] Rail heating circuit current I
[0044] I = √(Q / Rt)
[0045] Where: t is the heating time of the railway rail, and R is the resistance of the railway rail.
[0046] This invention relates to a system where, when railway rails require heating, AC power is supplied to an electric heating film to form a circuit. A large current is then applied to the heating film to generate heat, which is then placed over the railway rail to be heated. After a target temperature is set in the temperature control unit, the actual temperature is compared in real time. When the surface temperature of the heated rail reaches the set target temperature, the rectifier module automatically stops working; when the surface temperature of the heated rail has not reached the set target temperature, the rectifier module continues heating, thus achieving temperature comparison and feedback.
Claims
1. A railway rail heating device, characterised in that: It includes power supply (1), control circuit (2) and electric heating film (3), the electric heating film (3) is fixed on the both sides of railway rail (5) through fixing frame (4), electric heating film (3) is electrically connected with power supply (1) through control circuit (2), control circuit (2) at least includes interface electric connection temperature sensor (6), current transformer (7) and input output interface circuit (8), input command to control circuit (2) through input output interface circuit (8), control circuit (2) receives the command of heating railway rail (5), control switch (9) is turned on, makes power supply (1) and electric heating film (3) connect, heats the both sides of railway rail (5) through electric heating film (3), control circuit (2) detects the temperature of temperature sensor (6) and the current of current transformer (7), so that the current flowing to electric heating film (3) and the temperature detected are in the set range;When railway rail needs to be heated, input ac power to electric heating film, so that it forms a loop, applies large current to electric heating film to make it heat, and electric heating film covers the required railway rail heating;After setting the target temperature in the temperature control unit, the actual temperature is compared in real time, and when the heated rail surface temperature reaches the set target temperature, the work is automatically stopped.
2. A railway rail heating device according to claim 1, characterised in that: The temperature sensor (6) is a thermocouple, and the thermocouple is distributed on the both sides of the railway rail (5) and is wrapped by the electric heating film (3) and the railway rail (5).
3. A railway rail heating device as claimed in claim 1, characterised in that: The fixing frame (4) is a memory alloy elastic frame.
4. A railway rail heating device as claimed in claim 3, characterised in that: The fixing frame (4) is a stainless steel elastic frame.
5. A railway rail heating device as claimed in claim 1, characterised in that: The switch (9) is a bidirectional thyristor, and the heating temperature is adjusted by the duty ratio of the bidirectional thyristor.
6. A railway rail heating device as claimed in claim 1, characterised in that: It includes an electric leakage protector (10), and the electric leakage protector (10) is electrically connected with the railway rail (5) and the grounding connection wire.
7. A railway rail heating device as claimed in claim 1, characterised in that: The control circuit (2) is supplied by a direct current power supply (11), and the direct current power supply (11) is supplied with 5V voltage by the switch power supply through the power supply (1).
8. A railway rail heating device as claimed in claim 1, characterised in that: The power supply (1) is a low-voltage power supply provided by an ac power supply through a switch power supply. The power supply (1) is a low-voltage power supply provided by an ac power supply through a switch power supply.