An electric heating device suitable for a motor train unit air duct

Abstract

The utility model discloses a kind of electric heating devices suitable for EMU air duct, to solve the problem of inconvenient maintenance of existing electric heater.It includes body, electric heater and insulating plate;Insulating plate is connected with wiring gran, and the edge of body maintenance cover plate is provided with terminal block, and electric heater is connected with power supply loop and control loop through terminal block.Electric heater contains at least two groups of independent heating units, integrated fuse and temperature control switch as temperature protection component, respectively connected in series in power supply loop and control loop and connected through terminal block.The device is connected with terminal block layout through independent shunt design, realizes single independent disassembly and maintenance, improves safety and compatibility, circuit connection is clear, suitable for EMU air conditioning ventilation system.

Description

Technical Field

[0001] This utility model relates to the technical field of air conditioning and ventilation systems for high-speed trains, and in particular to an electric heating device suitable for the air ducts of high-speed trains. Background Technology

[0002] As a core component of the air conditioning and ventilation system, the high-speed train not only circulates air and regulates temperature within the carriages but also requires acoustic design to reduce ventilation noise, directly impacting passenger comfort and the quietness of train operation. Among these components, the electric heater is crucial for temperature control, and its performance stability and ease of maintenance are vital to the train's operational efficiency. Currently, the structural design of electric heaters in high-speed trains largely follows mature designs from earlier models, with a core drawback being poor maintainability. Specifically, the electric heater is typically fixed directly inside the main body via an insulating plate, with the wiring harness integrated with the ductwork, resulting in a rigid bond between the heater and the duct structure. When maintenance or replacement of the electric heater is required, the inspection cover at the bottom of the duct must be removed first, followed by disassembling the connection structure between the heater and the ductwork. This process requires at least two workers—one to support the heavy heater to prevent it from falling, and the other to use tools to remove bolts and disconnect circuit connectors. This is not only time-consuming and labor-intensive but also carries the risk of component damage and accidental wiring contact.

[0003] Furthermore, existing electric heaters lack independent branch circuits for power and control, often employing integrated wiring where the circuits of each heating unit are connected to the main circuit via a single connector. This means that even replacing just one heating element or temperature control component requires disconnecting the entire power supply circuit for the duct, extending maintenance downtime and potentially causing poor contact due to repeated circuit disconnections, thus affecting system stability. Simultaneously, temperature protection components (such as fuses and temperature switches) are often embedded inside the electric heater, tightly fitted to the heating element and insulation board. Maintenance requires deep access into the duct, and the confined space makes it easy to damage components or misinstall them, further increasing maintenance costs and safety hazards.

[0004] With the increase in the operating mileage of high-speed trains and the improvement of maintenance standards, the drawbacks of the existing structure have become increasingly apparent: frequent maintenance work leads to reduced train turnaround efficiency, the multi-person operation mode increases labor costs, and the complexity of circuit connections increases the failure rate. Therefore, there is an urgent need for an electric heating device that can simplify the maintenance process, improve structural compatibility, and enhance operational safety to meet the actual needs of efficient high-speed train operation. Summary of the Invention

[0005] The purpose of this utility model is to overcome the shortcomings of the existing electric heaters in terms of inconvenience in inspection and maintenance, and to provide an electric heating device with optimized structure and convenient maintenance suitable for high-speed trains.

[0006] To achieve the above objectives, this utility model is implemented through the following technical solution:

[0007] This utility model provides an electric heating device suitable for the air duct of a high-speed train, including an air duct body, an electric heater disposed inside the body, and an insulating plate for fixing the electric heater; the insulating plate is provided with a wiring harness, and a terminal block is provided at the edge of the area covered by the inspection cover of the body; the electric heater is connected to a power circuit and a control circuit through the terminal block. The electric heater is used to heat the air inside the air duct, the wiring harness serves as a sealed interface for wires to pass through, the power circuit provides operating power to the electric heater, and the control circuit controls the operating status of the electric heater.

[0008] The insulating plate, on the one hand, securely fixes the electric heater inside the main body through the mounting structure, preventing displacement or detachment due to train vibration; on the other hand, it is made of insulating material, blocking electrical conduction between the electric heater and the main body, thus providing insulation protection. The wiring harness is located on the insulating plate, providing a passage and sealed interface for the electric heater's wires. Internal seals prevent airflow, dust, condensation, etc., from entering the electrical connection area, while also securing the wires to prevent vibration-induced wear. The terminal block is located at the edge of the area covered by the main body's inspection cover. This design allows for direct operation after opening the inspection cover, without needing to delve into the main body or disassemble other structures. This design facilitates quick disconnection or connection of circuits. As an intermediate connecting component, it connects the lead wires of the electric heater, the power circuit wires, and the control circuit wires via terminals. The power circuit transmits electrical energy from the train's power supply system to the electric heater, providing it with operating power. The control circuit connects to the train's control system, regulating the electric heater's start-up, shutdown, power, and other operating states through transmission of control signals. Both components are connected to the electric heater via terminal blocks. By optimizing component layout and connection methods, the overall structure solves the problems of rigid binding between the electric heater and the main body in traditional structures, requiring disassembly of the main body for maintenance. This significantly improves maintenance convenience and operational reliability.

[0009] Furthermore, the power circuit includes a power input terminal and a power line connected in series between the power input terminal and the electric heater. The power line is electrically connected to the power interface of the electric heater through the terminal block to realize power transmission.

[0010] Furthermore, the control loop includes a control unit and a control line connected between the control unit and the electric heater. The control line is electrically connected to the control interface of the electric heater through the terminal block to realize the operation control of the electric heater.

[0011] The control circuit, as the physical carrier of signal transmission, typically uses multi-core wires with insulation protection. One end is connected to the signal output terminal of the control unit, and the other end is connected to the control interface of the electric heater through a terminal block to form a detachable electrical connection. This connection method achieved through the terminal block not only ensures the stability of control signal transmission, but also allows the control circuit to be separated without damaging the overall structure of the control circuit when the electric heater is repaired or replaced. The control circuit can be separated simply by disconnecting the corresponding contacts on the terminal block, which greatly simplifies the operation process.

[0012] The control interface of the electric heater is a terminal for receiving external control signals. Its connection with the control line through the terminal block enables the signal output by the control unit to be accurately transmitted to the drive circuit inside the electric heater. This allows the electric heater to adjust its working state according to the signal command (such as starting heating, stopping heating, or switching to different power levels). Ultimately, this achieves effective control of the electric heater's operation by the control unit, while also ensuring the reliability of the circuit connection and the convenience of maintenance.

[0013] Furthermore, the electric heater integrates a temperature protection component, which includes a fuse and a temperature control switch. The fuse is connected in series in the power supply circuit, and one end of the fuse is connected to the power interface of the electric heater through the terminal block. The temperature control switch is connected in series in the control circuit, and one end of the temperature control switch is connected to the control interface of the electric heater through the terminal block for over-temperature protection.

[0014] The integrated temperature protection component of the electric heater is a key structure for ensuring the safe operation of the device. Through the synergistic action of a fuse and a temperature control switch, it provides dual protection against two types of risks: overcurrent and overtemperature. The fuse, acting as an overcurrent protection element in the power circuit, uses a fuse specification matched to the rated current of the power circuit and is detachably connected via a terminal block. This connection method ensures electrical continuity when the fuse is connected to the power circuit and facilitates quick replacement via the terminal block at the maintenance cover after the fuse blows due to overcurrent, without disassembling the electric heater itself. When a short circuit, overload, or other abnormal condition occurs in the power circuit causing the current to exceed the rated value, the fuse will quickly blow, cutting off the connection between the electric heater and the power supply, preventing the electric heater from burning out or the circuit from catching fire due to continuous overcurrent.

[0015] The temperature control switch serves as an over-temperature protection element in the control circuit. It typically employs a mechanical or electronic switch with temperature sensing capabilities. Its sensing end is in close contact with the heating element of the electric heater, enabling real-time monitoring of the heater's operating temperature. Both ends are connected to the control circuit and the heater's control interface via terminal blocks, forming a protection path connected in series within the control circuit. When the electric heater's temperature exceeds the safety threshold due to abnormal operating conditions, the temperature control switch automatically disconnects, cutting off the control signal output from the control unit to the heater, causing it to stop heating. The switch automatically resets or requires manual intervention once the temperature drops to a safe range, thus preventing the heater from malfunctioning due to sustained high temperatures, such as thermal deformation or insulation aging.

[0016] Furthermore, the outer dimensions of the insulating plate are adapted to the body, and the insulating plate is provided with mounting holes corresponding to the body. The number, position, and diameter of the mounting holes, including heating tube mounting positions, temperature control mounting positions, and wiring harnesses, are all matched one by one with the fixing structure on the body. The insulating plate can be firmly fixed to the body with bolts or other fasteners, ensuring the installation stability of the insulating plate and the electric heater even in the vibration environment of high-speed train operation, preventing displacement or loosening. The wires running through the wiring harness serve as extension paths for the power circuit and control circuit, respectively connecting the electric heater and the terminal block, achieving sealed protection of the circuit.

[0017] Furthermore, the electric heater includes at least two independent heating units. The power interface of each heating unit is connected to the power circuit through the terminal block to form an independent branch circuit. The control interface of each heating unit is connected to the control circuit through the terminal block to form an independent branch circuit, thereby enabling individual disassembly and maintenance of each heating unit.

[0018] The electric heater employs a design with at least two independent heating units, a modular structure designed to meet the high requirements of high-speed trains for the reliability and ease of maintenance of the heating system. "Independent heating unit" means that each unit can independently perform its heating function, containing independent heating tubes, power interfaces, and control interfaces. There is no direct structural or circuit connection between the units; even if one unit fails, the others can still operate normally, preventing the entire electric heater from failing due to a single unit's failure and significantly improving system fault tolerance. Simultaneously, each unit has its own dedicated power path, which is led out from the power circuit and connected to the unit's power interface via corresponding terminals on the terminal block. There are no shared lines between the power branches of each unit. This design allows for maintenance of a unit by simply disconnecting its corresponding power branch (via the terminal block), without needing to cut off the main power supply to the entire electric heater, ensuring the normal operation of other units and simplifying the power-off procedure.

[0019] The advantages and beneficial effects of this utility model are as follows:

[0020] 1. Improved maintenance convenience: By setting the terminal block on the edge of the inspection cover and adopting an independent branch design, the soundproof air duct body does not need to be disassembled during maintenance. A single person can complete the disassembly and maintenance of the electric heater, which greatly improves maintenance efficiency.

[0021] 2. Enhanced safety: The device integrates a dual protection component consisting of a fuse and a temperature control switch, providing overcurrent and over-temperature protection for both the power supply and control circuits, thereby improving the operational safety of the device.

[0022] 3. Good structural compatibility: The dimensions and mounting holes of the insulation board are compatible with the sound-absorbing duct body, and it can be installed without modifying the main structure of the duct, making it suitable for upgrading and retrofitting existing EMUs.

[0023] 4. Clear circuit connection: The grouped wiring design of the terminal block makes the connection relationship between the power circuit and the control circuit clear, reduces the risk of misoperation, and facilitates troubleshooting. Attached Figure Description

[0024] Figure 1 This is a schematic diagram of the structure of the air duct body of the EMU (Electric Multiple Unit) according to this utility model;

[0025] Figure 2 This is a schematic diagram of the structure of the electric heating device inside the air duct of this utility model;

[0026] In the diagram: 1. Body; 2. Electric heater; 3. Insulating board; 4. Wiring connector; 5. Terminal block; 6. Fuse; 7. Temperature control switch. Detailed Implementation

[0027] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0028] like Figure 1 , Figure 2As shown, an electric heating device suitable for the air duct of a high-speed train includes an air duct body, an electric heater disposed inside the air duct body, and an insulating plate for fixing the electric heater. The insulating plate is provided with a wiring harness, and a terminal block is provided at the edge of the area covered by the inspection cover of the air duct body. The electric heater is connected to a power circuit and a control circuit through the terminal block. The electric heater is used to heat the air inside the air duct, the wiring harness serves as a sealed interface for wires to pass through, the power circuit provides operating power to the electric heater, and the control circuit controls the operating status of the electric heater.

[0029] In this embodiment, the 7kW electric heater (divided into 2 groups, each group 3.5kW) in the silencing duct obtains power through the power supply circuit and its operating status is regulated by the control circuit. The electric heater is equipped with two-stage temperature protection components that work synchronously. The temperature control switch monitors the temperature in the control circuit, and the fuse is connected in series on the 4 power lines of the 2 main power supply circuits. When over-temperature or over-current occurs, the corresponding protection components will automatically cut off the circuit to ensure the safe operation of the device.

[0030] During inspection and maintenance, the circuit connection of the target heating unit can be directly disconnected through the terminal block without disassembling the electric heating element and connector. At the same time, the mounting holes and external dimensions of the insulation board remain unchanged. Only the spacing of the heating tubes and the installation position of the temperature control are adjusted. A single person can independently complete the disassembly, inspection or replacement of a single heating unit without the need for multiple people to lift it.

[0031] Preferably, in this embodiment, the power circuit includes a power input terminal and a power line connected in series between the power input terminal and the electric heater. The power line is electrically connected to the power interface of the electric heater through the terminal block to realize power transmission.

[0032] Preferably, the control loop includes a control unit and a control line connected between the control unit and the electric heater. The control line is electrically connected to the control interface of the electric heater through the terminal block to realize the operation control of the electric heater.

[0033] The control circuit, as the physical carrier of signal transmission, typically uses multi-core wires with insulation protection. One end is connected to the signal output terminal of the control unit, and the other end is connected to the control interface of the electric heater through a terminal block to form a detachable electrical connection. This connection method achieved through the terminal block not only ensures the stability of control signal transmission, but also allows the control circuit to be separated without damaging the overall structure of the control circuit when the electric heater is repaired or replaced. The control circuit can be separated simply by disconnecting the corresponding contacts on the terminal block, which greatly simplifies the operation process.

[0034] The control interface of the electric heater is a terminal for receiving external control signals. Its connection with the control line through the terminal block enables the signal output by the control unit to be accurately transmitted to the drive circuit inside the electric heater. This allows the electric heater to adjust its working state according to the signal command (such as starting heating, stopping heating, or switching to different power levels). Ultimately, this achieves effective control of the electric heater's operation by the control unit, while also ensuring the reliability of the circuit connection and the convenience of maintenance.

[0035] Preferably, the electric heater integrates a temperature protection component, which includes a fuse and a temperature control switch; the fuse is connected in series in the power supply circuit, and one end of the fuse is connected to the power interface of the electric heater through the terminal block; the temperature control switch is connected in series in the control circuit, and one end of the temperature control switch is connected to the control interface of the electric heater through the terminal block, for over-temperature protection.

[0036] In this embodiment, two commercially available standard fuses are connected in series in the power supply circuit of each heating unit. The rated current matches the load of the heating unit, and the modular connection to the power line is achieved through a standard four-pole terminal block near the air duct inspection port. The fuses are directly connected in series in the phase and neutral circuits of the heating unit. When the circuit current exceeds the rated value (such as short circuit or overload), the fuse melts and cuts off the power supply, thus achieving overcurrent protection.

[0037] A mechanical temperature switch is connected in series in the control circuit, with an operating temperature set at 90℃ (±5℃). A bimetallic strip structure is used to achieve temperature triggering. The normally closed contact of the temperature control switch is connected to the output line of the control unit through the same terminal block. When the surface temperature of the electric heater rises to 90℃ due to abnormal conditions such as air duct blockage, the bimetallic strip deforms due to heat, opens the contact, cuts off the control signal, and stops the electric heater from working.

[0038] Both the fuses and temperature control switches are electrically connected via standard four-pole terminal blocks on an insulating board. These terminal blocks support quick plugging and unplugging and have an IP54 protection rating. The fuse input terminal of the power circuit is connected to the main power bus of the trainset via a crimp terminal, while the output terminal is connected to the heating unit via the terminal block. The temperature control switch of the control circuit is directly connected to the I / O module of the onboard PLC control system via the terminal block. This design allows the protection components and the electric heater to form an independent module, enabling direct disconnection of the target unit via the terminal block during maintenance, without disassembling the entire air duct structure.

[0039] When the electric heater triggers the temperature control switch due to abnormal temperature rise, the control unit simultaneously cuts off the power circuit contactor, achieving dual protection of "signal cut-off - power isolation". If the temperature control switch fails to respond in time due to mechanical failure, the fuse will blow under continuous overload current, forming a second level of physical isolation. The two sets of protection components achieve complete isolation between signal and power through independent channels of the terminal block, avoiding mutual interference.

[0040] Preferably, in this embodiment, the insulating plate is made of high-temperature resistant epoxy glass cloth, and a 10mm gap is reserved at the edge of the insulating plate to avoid interference with the inner wall of the main body, while ensuring installation space for the heating components. The insulating plate is provided with mounting holes corresponding to the main body. The number, position, and diameter of the mounting holes, including heating tube mounting positions, temperature control mounting positions, and wiring harnesses, are matched one by one with the fixing structure on the main body. The insulating plate can be firmly fixed to the main body with bolts or other fasteners, ensuring the installation stability of the insulating plate and the electric heater even in the vibration environment of high-speed train operation, preventing displacement or loosening. The wires running through the wiring harness serve as extension paths for the power circuit and control circuit, respectively connecting the electric heater and the terminal block, achieving sealed protection of the circuit.

[0041] Preferably, in this embodiment, the electric heater includes two sets of independent heating units. The power interface of each heating unit is connected to the power circuit through the terminal block to form an independent branch connection. The control interface of each heating unit is connected to the control circuit through the terminal block to form an independent branch connection, so as to realize the individual disassembly and maintenance of each heating unit.

[0042] The electric heater employs a design with at least two independent heating units, a modular structure designed to meet the high requirements of high-speed trains for the reliability and ease of maintenance of the heating system. "Independent heating unit" means that each unit can independently perform its heating function, containing independent heating tubes, power interfaces, and control interfaces. There is no direct structural or circuit connection between the units; even if one unit fails, the others can still operate normally, preventing the entire electric heater from failing due to a single unit's failure and significantly improving system fault tolerance. Simultaneously, each unit has its own dedicated power path, which is led out from the power circuit and connected to the unit's power interface via corresponding terminals on the terminal block. There are no shared lines between the power branches of each unit. This design allows for maintenance of a unit by simply disconnecting its corresponding power branch (via the terminal block), without needing to cut off the main power supply to the entire electric heater, ensuring the normal operation of other units and simplifying the power-off procedure.

[0043] In addition, the installation dimensions of the two heating units are completely identical, and their fixing holes and interface specifications with the insulation plate are also consistent, achieving interchangeability, further improving maintenance efficiency, and fully meeting the high reliability and fast maintenance operation requirements of the EMU.

[0044] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the technical principles of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. An electric heating device suitable for the air duct of a high-speed train, characterized in that, It includes a duct body, an electric heater disposed inside the body, and an insulating plate for fixing the electric heater; the insulating plate is provided with a wiring rack, and a terminal block is provided at the edge of the area covered by the inspection cover of the body; the electric heater is connected to a power circuit and a control circuit respectively through the terminal block.

2. The electric heating device for the air duct of a high-speed train according to claim 1, characterized in that, The power circuit includes a power input terminal and a power line connected in series between the power input terminal and the electric heater. The power line is electrically connected to the power interface of the electric heater through the terminal block.

3. The electric heating device for the air duct of a high-speed train according to claim 1, characterized in that, The control circuit includes a control unit and a control line connecting the control unit and the electric heater. The control line is electrically connected to the control interface of the electric heater through the terminal block.

4. The electric heating device for the air duct of a high-speed train according to claim 1, characterized in that, The electric heater integrates a temperature protection component, which includes a fuse and a temperature control switch. The fuse is connected in series in the power supply circuit, and one end of the fuse is connected to the power interface of the electric heater through the terminal block. The temperature control switch is connected in series in the control circuit, and one end of the temperature control switch is connected to the control interface of the electric heater through the terminal block.

5. An electric heating device suitable for the air duct of a high-speed train according to claim 1, characterized in that, The outer dimensions of the insulating plate are adapted to the body. The insulating plate is provided with mounting holes corresponding to the body. The insulating plate is provided with heating tube mounting positions, temperature control mounting positions and wiring harnesses. The wires passing through the wiring harnesses serve as extension paths for the power circuit and control circuit, respectively connecting the electric heater and the terminal block.

6. An electric heating device suitable for the air duct of a high-speed train according to claim 1, characterized in that, The electric heater includes at least two independent heating units. The power interface of each heating unit is electrically connected to the power circuit through the terminal block, and the control interface of each heating unit is electrically connected to the control circuit through the terminal block.

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