A method and system for regulating the internal air pressure of a high-speed train carriage when passing through a tunnel

Abstract

The present invention relates to the technical field of controlling the aerodynamic effects of trains in high-speed railway tunnels, and particularly relates to a method and system for regulating the air pressure inside the carriages when a high-speed train passes through a tunnel. The method for regulating the air pressure inside the carriages when the high-speed train passes through the tunnel includes: obtaining the time t when the train is about to enter the tunnel from the high-speed train control system; comparing the magnitudes of t and t0: when t > t0, controlling the carriage ventilation system to maintain the normal mode; when t ≤ t0, controlling the carriage ventilation system to switch to the pressure reduction mode until the train enters the tunnel, and then controlling the carriage ventilation system to switch to the normal mode; t0 is the expected duration for the carriage ventilation system to operate in the pressure reduction mode, and the pressure reduction mode is a working mode in which the carriage ventilation system continuously exhausts air outward to reduce the air pressure inside the carriage at a rate acceptable to the human ear.

Description

Technical Field

[0001] The present invention relates to the technical field of aerodynamic effect control of trains in high-speed railway tunnels, and in particular to a method and system for controlling the air pressure inside a carriage when a high-speed train passes through a tunnel. Background Art

[0002] As the most important rapid public transportation in my country, high-speed trains are in a stage of vigorous development. It is particularly important to fully ensure the safety and comfort of passengers for the operation and development of my country's high-speed rail. Studies have shown that when a train runs in a tunnel at a speed of 200km / h or above, the violent air pressure fluctuations outside the carriage will be transmitted into the carriage through the leakage gap on the car body, causing significant fluctuations in the air pressure inside the car. The obvious air pressure fluctuations inside the carriage act on structures such as the eardrum of the human ear, causing symptoms such as tinnitus, ear pain, nausea and even mild vomiting. Therefore, in order to ensure the comfort and safety of train passengers, all countries have formulated threshold standards for air pressure changes inside the carriage to limit the air pressure fluctuations inside the carriage to a specific range of comfort acceptable to the human ear. When the air pressure fluctuations inside the carriage of an actual train exceed this range, it will seriously affect the comfort of passengers and even threaten their health and safety.

[0003] How to control the pressure fluctuation inside the carriage within the range required by the comfort standard when the high-speed train passes through the tunnel has become a key issue that needs to be solved in the development of high-speed trains in various countries. The most direct way to prevent the pressure inside the carriage from being affected by the pressure fluctuation of the outside air is to enhance the air tightness of the train body and reduce the leakage gap, but this method not only has very high requirements for the production and manufacturing technology, but also will lead to a significant increase in manufacturing costs. For the large number of high-speed trains that have been put into operation, this method of increasing the air tightness of the body structure is not only not applicable, but also with the increase of the train's operating mileage and service time, the air tightness of the body structure will deteriorate. Therefore, the current control of the pressure fluctuation inside the train carriage is mainly through the use of a specific pressure fluctuation control system to control the mode of action of the train air conditioning and ventilation system, so as to achieve the alleviation and control of the pressure fluctuation inside the carriage.

[0004] According to different control mechanisms, the currently mainly adopted internal air pressure control methods for carriages at home and abroad are divided into two categories: passive control and active control. (1) Passive internal air pressure control for carriages: A pressure control valve is used. When the air pressure outside the carriage fluctuates greatly and reaches a specific threshold, or when a control signal is received before entering a tunnel, the control valve is closed to directly disconnect the air exchange channel between the inside and outside of the carriage, isolating the internal environment of the carriage from the external air environment, and avoiding the drastic air pressure fluctuations outside the carriage from being transmitted into the carriage through the ventilation system, so as to achieve the control of the internal air pressure fluctuations in the carriage. However, during the operation of this control method, the air inside the carriage cannot convect with the outside world, the air quality inside the carriage will deteriorate significantly, and for long tunnels or continuous tunnel groups, this method will cause a serious shortage of the ventilation volume inside the carriage, which will also affect the comfort and safety of passengers; (2) Active internal air pressure control for carriages: The air pressure fluctuations inside the carriage are monitored in real time. According to the characteristics of the air pressure fluctuations inside the carriage, the operating frequencies of the intake fan and the exhaust fan in the ventilation system are actively adjusted to achieve real-time dynamic control of the intake air volume and the exhaust air volume, offsetting the air pressure fluctuations inside the carriage caused by the air pressure fluctuations outside the carriage, so as to dynamically maintain the air pressure fluctuations inside the carriage within the comfort standard range. However, the control mechanism of this control system is complex, has high technical requirements, and also has a high cost.

[0005] In summary, at present, a mature control technology for the air pressure fluctuations inside the high-speed train carriages has not been formed, and the air pressure fluctuations inside the carriages when the train passes through the tunnel still generally affect the comfort of passengers. For China, at present, the operating speeds of many high-speed railways have reached 350 km / h, and the research on high-speed trains with a speed grade of 400 km / h is also in a stage of rapid development. The comfort and safety problems caused by such air pressure fluctuations are more prominent.

[0006] Therefore, there is an urgent need for a general and feasible method for regulating the air pressure of train carriages in tunnels, which can effectively control the air pressure fluctuations inside the carriages and ensure the comfort and safety of passengers. Summary of the Invention

[0007] When a high-speed train passes through a tunnel, the air pressure outside the carriage shows a pressure wave dominated by obvious negative pressure. If the normal air pressure is maintained inside the carriage when entering the tunnel, due to the large pressure difference between the air pressure inside and outside the carriage, the air pressure inside the carriage will fluctuate violently along with the air pressure outside the carriage. Compared with the normal air pressure environment inside the carriage without disturbance, if the inside of the carriage is a negative pressure environment with a certain negative pressure value, it can significantly reduce the peak value of the rate of change of the air pressure inside the carriage with the fluctuation of the external air pressure after the train enters the tunnel.

[0008] The present invention provides a method and system for regulating the air pressure fluctuation inside the carriages of a high-speed train in a tunnel. By reducing the internal air pressure environment of the carriage to a negative pressure environment with a specific negative pressure value of the internal pressure difference before the train enters the tunnel, the carriage enters the tunnel with a specific negative pressure environment, thereby reducing the peak rate of air pressure fluctuation inside the carriage. It has universality and feasibility, can effectively control the air pressure fluctuation inside the carriage, and ensure the comfort and safety of passengers.

[0009] The technical solution of the present invention is detailed as follows:

[0010] In a first aspect, a method for regulating the air pressure inside the carriage of a high-speed train when passing through a tunnel includes the following steps:

[0011] S1. Obtain the time t when the train is about to enter the tunnel from the high-speed train control system.

[0012] S2. Compare the magnitudes of t and t0:

[0013] When t > t0, control the carriage ventilation system to maintain the normal mode.

[0014] When t ≤ t0, control the carriage ventilation system to switch to the pressure reduction mode until the train enters the tunnel, and then control the carriage ventilation system to switch to the normal mode.

[0015] The t0 is the set duration for the carriage ventilation system to operate in the pressure reduction mode. The pressure reduction mode is a working mode in which the carriage ventilation system continuously exhausts air outward to reduce the internal air pressure of the carriage at a rate acceptable to the human ear.

[0016] The normal mode of the carriage ventilation system is a working mode in which when the high-speed train runs at the speed required by the line, in order to ensure the fresh air volume inside the carriage, the air inside the carriage and the air outside the carriage continuously convect. The high-speed train operation control system is well-known in the art and has no special requirements. It can provide the speed of the train and the distance from the tunnel in real time, and t can be obtained after simple setting and calculation. Entering the tunnel means that the train head enters the entrance of a single tunnel or the entrance of the first tunnel in a tunnel group, and exiting the tunnel means that the train tail exits the tunnel exit or the exit of the last tunnel in a tunnel group.

[0017] Further, the tunnel is a single tunnel or the first tunnel in a tunnel group. The tunnel group refers to a multi-tunnel combination in which the distance between adjacent two tunnels is less than the set threshold s0, and s0 = 2 × v0 × t0, where v0 is the operating speed required by the high-speed rail line where the train is located.

[0018] Further, p tis the set target value of the air pressure inside the carriage, p0 is the normal air pressure value, p0 is a constant, and its magnitude is equal to the air pressure inside the carriage when the train runs at the required speed on the high - speed rail line in non - tunnel sections. Δp is the rate of decrease of the air pressure inside the carriage when the carriage ventilation system switches to the pressure - reducing mode (p t - p0) is the set target value of the internal pressure difference, (p t - p0) ∈ [-700, -100].

[0019] The t0 is calculated according to the above formula. The internal pressure difference is equal to the air pressure inside the carriage minus the normal air pressure value p0, and the external pressure difference is equal to the air pressure outside the carriage minus the normal air pressure value p0. p0 is the air pressure inside the carriage when the train runs at the required speed on the high - speed rail line in non - tunnel sections. At this time, the air pressure inside the carriage is relatively stable, with small fluctuations, and is very close to the air pressure outside the carriage. Its value is equivalent to the local atmospheric pressure level. In practice in this field, the air pressure inside the carriage and the air pressure outside the carriage at this time can be regarded as equal and consistent with the local ambient atmospheric pressure level.

[0020] Further, when t ∈ [t0, 2t0], start the countdown. After counting down (t - t0) seconds, control the carriage ventilation system of the train to switch to the pressure - reducing mode. After the pressure - reducing mode runs continuously for t0 seconds, control the carriage ventilation system to switch to the normal mode. In this way, when the signal obtained from the high - speed train control system is unstable, the regulation of the air pressure inside the carriage when the high - speed train passes through the tunnel can also be completed.

[0021] Further, obtain the signal that the train enters the tunnel from the high - speed train control system. The high - speed train operation control system is well - known in the art and can real - time locate the position of the train and the condition of the front line. A simple setting can send a prompt signal when the train enters the tunnel.

[0022] Further, t0 is less than or equal to 60 seconds.

[0023] Further, Δp is less than or equal to 40 Pa / s.

[0024] In the second aspect, a control system for the air pressure inside the carriage when a high - speed train passes through a tunnel includes:

[0025] A signal acquisition device for acquiring the signal of the high - speed train control system, and the signal is the real - time position of the train and the time t to enter the tunnel soon.

[0026] An analysis and control device, which obtains information from the signal acquisition device and, through the set target value p t calculates t0, and sends an instruction to the carriage ventilation system after comparing the magnitudes of t and t0.

[0027] The car ventilation system is used to switch between the normal mode and the pressure reduction mode according to the instructions of the analysis and control device. The pressure reduction mode is a working mode in which the car ventilation system continuously exhausts air outward to reduce the air pressure inside the car at a rate acceptable to the human ear.

[0028] Furthermore, the car ventilation system includes an exhaust jet fan, which is used to receive the signal of the analysis and control device and assist in exhausting air outward.

[0029] Based on the mechanism of the mutual transfer of air pressure inside and outside the car, the present invention proposes a method for regulating the air pressure inside the car of a high-speed train when passing through a tunnel. Figure 1 The following shows the time history curve data of the typical external pressure difference change during the train passing through the tunnel obtained from on-site tests. The internal pressure difference is equal to the air pressure inside the car minus the normal air pressure value p0, and the external pressure difference is equal to the air pressure outside the car minus the normal air pressure value p0. Since p0 is a constant, there is a linear relationship between the internal pressure difference and the air pressure inside the car, and between the external pressure difference and the air pressure outside the car. In the research in this field, the change characteristics of the air pressure inside and outside the car are generally studied by observing the changes in the internal pressure difference and the external pressure difference. As shown in the time history curve of the external pressure difference change, during the train passing through the tunnel, the air pressure outside the car is mainly dominated by an obvious negative pressure. Under the action of the external pressure difference, the internal pressure difference gradually fluctuates and drops from the initial value near zero to a specific negative pressure value. As is well known in the art, the simplified theoretical model of the air pressure inside the car fluctuating with the air pressure outside the car can be represented by the following differential equation:

[0030]

[0031] In the formula, τ dyn is a positive real number that reflects the dynamic sealing characteristics of the train car body to air pressure changes. Its value depends on the car body structure characteristics and some environmental characteristics. For a specific car passing through a certain tunnel, its value can be regarded as a relatively constant value. p e (t) and p i (t) are the air pressure outside and inside the high-speed train car body at time t respectively. For an actual operating train, both of them will change significantly with time, so they are variables that change with time t. This differential equation model can well describe the mechanism of the air pressure p dyn inside the train car body with a dynamic airtightness index of τ i (t) changing with the air pressure p e (t) outside the car body. Given the known airtightness index and the air pressure data outside the car body, the change characteristics of the air pressure inside the car can be obtained by solving this differential equation. This numerical solution method for the air pressure inside the train car body running in the tunnel has been widely applied and accepted in the field of high-speed train research and has achieved good research results.

[0032] As can be seen from the above formula, for the train carriages passing through a certain tunnel, the value of the airtightness characteristic index of the air pressure can be set as a constant value that basically does not change. At this time, the change characteristic of the air pressure inside the carriage during the train passing through the tunnel will directly depend on the pressure difference characteristic between the air pressure inside the carriage and the external air pressure. The smaller the difference between the air pressure inside the carriage and the external air pressure, the slower the change of the air pressure inside the carriage. On the contrary, the air pressure inside the carriage will fluctuate violently with the external air pressure of the carriage, affecting the comfort of passengers.

[0033] Based on the above research on the essence of the change process of the air pressure inside the carriage with the external air pressure, the present invention starts from changing the degree of the pressure difference between the air pressure inside the carriage and the external air pressure, and can effectively control the fluctuation degree of the air pressure inside the train carriage running in the tunnel.

[0034] Next, the present invention will be further described in detail with reference to the accompanying drawings. Description of the Drawings

[0035] The drawings forming a part of this application are used to provide a further understanding of the present invention. The schematic embodiments and descriptions of the present invention are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings:

[0036] Figure 1 It is the measured curve graph of the external pressure difference and the internal pressure difference of the train running in the tunnel in this embodiment;

[0037] Figure 2 It is the flow chart of the method for regulating the air pressure inside the carriage when the high-speed train passes through the tunnel in this embodiment;

[0038] Figure 3 It is the countdown flow chart of the method for regulating the air pressure inside the carriage when the high-speed train passes through the tunnel in this embodiment;

[0039] Figure 4 It is the external pressure difference curve and the corresponding internal pressure difference curves under different initial internal pressure difference environments in this embodiment;

[0040] Figure 5 It is the comparison effect diagram after the starting points of different internal pressure difference curves in this embodiment are moved consistently;

[0041] Figure 6 It is the 3s change amplitude curve of the internal pressure difference of the carriage during the tunnel operation under different initial internal pressure differences in this embodiment;

[0042] Figure 7 It is the 1s change amplitude curve of the internal pressure difference of the carriage during the tunnel operation under different initial internal pressure differences in this embodiment. Detailed Description of the Invention

[0043] The embodiments of the present invention will be described in detail below with reference to the accompanying drawings. However, the present invention can be implemented in many different ways defined and covered by the claims.

[0044] Embodiment 1:

[0045] Referring to Figure 2 , in a preferred embodiment of the present invention, a method for regulating the internal air pressure of a carriage when a high-speed train passes through a tunnel is provided, including the following steps:

[0046] The signal acquisition device obtains a signal from the train control system and gets that the train will enter the tunnel in 60 seconds.

[0047] The analysis and control device sets the target internal pressure difference of the train before entering the tunnel to -500 Pa. The rate of decrease in the internal air pressure of the carriage in the pressure reduction mode of the carriage ventilation system is 25 Pa / s. After calculation by the analysis and control device, the time t0 required to reach the target value is 20 s, and the magnitudes of t and t0 are compared.

[0048] When t > 20, the carriage ventilation system maintains the normal working mode; when t ≤ 20, the carriage ventilation system is controlled to switch to the pressure reduction mode to continuously decrease the air pressure in the carriage.

[0049] The signal acquisition device obtains the signal that the train has entered the tunnel from the train control system and controls the carriage ventilation system to switch to the normal mode.

[0050] Embodiment 2:

[0051] Referring to Figure 3 , in a preferred embodiment of the present invention, a method for regulating the internal air pressure of a carriage when a high-speed train passes through a tunnel is provided, including the following steps:

[0052] The signal acquisition device obtains a signal from the train control system and gets that the train will enter the tunnel in 60 seconds.

[0053] The analysis and control device sets the target internal pressure difference of the train before entering the tunnel to -500 Pa. The rate of decrease in the internal air pressure of the carriage in the pressure reduction mode of the carriage ventilation system is 25 Pa / s. After calculation by the analysis and control device, the time t0 required to reach the target value is 20 s, and the magnitudes of t and t0 are compared.

[0054] When t = 40, a countdown is started. After 20 seconds of countdown, the carriage ventilation system of the train is controlled to switch to the pressure reduction mode. After the pressure reduction mode runs continuously for 20 seconds, the carriage ventilation system is controlled to switch to the normal mode.

[0055] In Embodiment 1 and Embodiment 2, the external air pressure data of the car body are the measured external pressure difference data when the high-speed train passes through a 2,203-meter-long tunnel at a speed of 300 km / h; the internal air pressure of the car body is calculated using the assumed linear pressure transfer model based on the train dynamic seal index widely used in the study of train airtight performance to obtain the internal pressure difference data.

[0056] Figure 4 The figure shows the change of the internal pressure difference under the action of the external pressure difference fluctuation during the train running in the tunnel after the train car body enters the tunnel under different initial internal pressure environment values. To facilitate the comparison of the internal pressure difference fluctuations corresponding to different initial internal pressure differences in this embodiment, the initial points of all internal pressure difference change curves are moved to the same point, and the Figure 5 curve results are obtained. It can be clearly seen that the greater the negative pressure value of the initial negative pressure environment before the car body enters the tunnel, the slower the change rate of the internal air pressure of the car body during the train running in the tunnel.

[0057] Figure 6 The figure is the characteristic curve of the 3s change amplitude of the internal air pressure of the car body calculated according to each internal pressure difference change curve. It can be seen that there are two relatively large peak points in the 3s air pressure change amplitude, which respectively correspond to the two negative peak points of the external air pressure of the car body. The peak points of the 3s air pressure change amplitude at these two places decrease significantly with the increase of the initial negative pressure value of the internal air pressure of the car body. Compared with the case where the initial internal pressure difference is 0, when the initial internal pressure of the car body is controlled to -50Pa, -100Pa, -200Pa, -300Pa, -500Pa respectively, the values of the first maximum peak point of the 3s air pressure change amplitude decrease by -1.94%, -4.00%, -7.96%, -11.93%, -19.80% respectively; the values of the second sub-maximum peak point decrease by -2.19%, -4.40%, -8.81%, -13.17%, -21.94% respectively.

[0058] Figure 7 The figure is the characteristic curve of the 1s change amplitude of the internal air pressure of the car body calculated according to each internal pressure difference change curve. It can be seen that there are also two relatively large peak points in the 1s air pressure change amplitude, which respectively correspond to the two negative peak points of the external air pressure of the car body. The peak points of the 1s air pressure change amplitude at these two places decrease significantly with the increase of the initial negative pressure value of the internal air pressure of the car body. Compared with the case where the initial internal pressure difference is 0, when the initial internal pressure of the car body is controlled to -50Pa, -100Pa, -200Pa, -300Pa, -500Pa respectively, the values of the first maximum peak point of the 1s air pressure change amplitude decrease by -1.93%, -3.66%, -6.62%, -9.91%, -16.46% respectively; the values of the second sub-maximum peak point decrease by -1.73%, -3.31%, -6.81%, -10.22%, -17.45% respectively.

[0059] In summary, the embodiments of the present invention can create a specific negative pressure value environment for the air pressure inside the carriage before the train enters the tunnel, so as to control the air pressure fluctuation inside the carriage during the operation of the train in the tunnel after entering the tunnel, and significantly relieve the intensity of the air pressure fluctuation inside the carriage after the train enters the tunnel, thereby achieving the purpose of relieving the impact of the air pressure fluctuation inside the carriage on the passenger comfort level.

[0060] The embodiments of the present invention also provide a control system for the air pressure inside the carriage when a high-speed train passes through a tunnel, including:

[0061] A signal acquisition device, configured to acquire signals from the control system of the high-speed train, where the signals are the real-time position of the train and the time t when it is about to enter the tunnel.

[0062] An analysis and control device, obtains information from the signal acquisition device, and calculates t0 through a set target value p t After comparing the magnitudes of t and t0, send an instruction to the carriage ventilation system.

[0063] A carriage ventilation system, configured to switch between a normal mode and a pressure reduction mode according to the instruction of the analysis and control device. The carriage ventilation system further includes an exhaust jet fan for assisting in exhausting air outward.

[0064] The above control system for the air pressure inside the carriage when a high-speed train passes through a tunnel can implement each embodiment of the above control method for the air pressure inside the carriage when a high-speed train passes through a tunnel, and can achieve the same beneficial effects, which will not be elaborated here.

[0065] The preferred specific embodiments of the present invention have been described in detail above. It should be understood that those of ordinary skill in the art can make many modifications and variations based on the concept of the present invention without creative efforts. Therefore, all technical solutions that can be obtained by those skilled in the art in the technical field of the present invention through logical analysis, reasoning, or limited experiments based on the concept of the present invention on the basis of the prior art shall fall within the protection scope determined by the claims.

Claims

1. A method for regulating the internal air pressure of a high-speed train carriage when passing through a tunnel, characterized by It includes the following steps: S1. Obtain the time t when the train is about to enter the tunnel from the high-speed train control system; S2. Compare the magnitudes of t and t0: When t > t0, control the car ventilation system of the train to maintain the normal mode; When t ≤ t0, control the car ventilation system to switch to the step-down mode until the train enters the tunnel, and then control the car ventilation system to switch to the normal mode; where \(t_0\) is the predicted duration for the carriage ventilation system to operate in the pressure reduction mode, and the pressure reduction mode is a working mode in which the carriage ventilation system continuously exhausts air outward to reduce the internal pressure of the carriage at a rate acceptable to the human ear; and \(t_0 =\) , \(p\) t is the set target value of the internal pressure of the carriage, \(p_0\) is the normal pressure value, \(p_0\) is a constant and is equal to the internal pressure of the carriage when the train runs at the required speed of the high-speed rail line on a non-tunnel section, \(\Delta p\) is the rate of decrease in the internal pressure of the carriage when the carriage ventilation system switches to the pressure reduction mode, \((p\) t - \(p_0\)) is the set target value of the internal pressure difference, \((p\) t - \(p_0\)) \(\in[-700, -100]\).

2. The method for regulating the internal air pressure of the carriage when a high-speed train passes through a tunnel according to claim 1, characterized in that The tunnel is a single tunnel or the first tunnel of a tunnel group. The tunnel group refers to a multi-tunnel combination where the distance between two adjacent tunnels is less than the set threshold s0, and s0 = 2 × v0 × t0, where v0 is the operating speed required for the high-speed rail line where the train is located.

3. The method for regulating the internal air pressure of the carriage when the high-speed train passes through the tunnel according to claim 1 or 2, characterized in that When t ∈ [t0, 2t0], start the countdown. After counting down for (t - t0) seconds, control the car ventilation system of the train to switch to the step-down mode. After the step-down mode operates for t0 seconds, control the car ventilation system to switch to the normal mode.

4. The method for regulating the internal air pressure of the carriage when the high-speed train passes through a tunnel according to claim 1 or 2, characterized in that, Obtain the signal that the train enters the tunnel from the high-speed train control system.

5. The method for regulating the internal air pressure of a carriage when a high-speed train passes through a tunnel according to claim 1 or 2, characterized in that, t0 is less than or equal to 60 seconds.

6. The method for regulating the internal air pressure of the carriage when a high-speed train passes through a tunnel according to claim 1 or 2, characterized in that, The rate of change of the internal pressure difference Δp is less than or equal to 40 Pa / s.

7. A control system for the internal air pressure of a carriage when a high-speed train passes through a tunnel according to the method of any one of claims 1-6, characterized in that, It includes: A signal acquisition device for acquiring the signal of the high-speed train control system, and the signal includes the time t when the train is about to enter the tunnel; The analysis and control device obtains information from the signal acquisition device and sets a target value p t Calculates t0, compares t with t0, and sends an instruction to the carriage ventilation system; A car ventilation system for accepting the instructions of the analysis and control device to switch between the normal mode and the step-down mode. The step-down mode is a working mode in which the car ventilation system continuously exhausts air to reduce the air pressure in the car at a rate acceptable to the human ear.

8. The air pressure regulation system inside the carriage when the high-speed train passes through a tunnel according to claim 7, characterized in that, The car ventilation system includes an exhaust jet fan.

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