A method for controlling the upper exhaust heat temperature of the condenser in a subway train during frequency reduction operation.

Abstract

This invention relates to a method for controlling the exhaust temperature of the subway train's condenser during reduced-frequency operation. A temperature sensor is used to monitor the exhaust air temperature at the exhaust vent of the exhaust system on the track in real time. When the exhaust air temperature exceeds a set temperature threshold, the train's condenser operates at a reduced frequency. This invention primarily optimizes the subway train's condenser operation strategy to control the exhaust temperature on the tunnel section, thereby preventing the train's condenser from shutting down due to excessively high intake air temperatures in summer.

Description

Technical Field

[0001] This invention relates to a method for controlling the heat dissipation temperature in the track area by relying on the reduced frequency operation of the condenser of a subway train, in order to prevent the train condenser from stopping due to excessive temperature, and belongs to the field of temperature control in the track area of ​​subway stations. Background Technology

[0002] The internal thermal environment of a subway is primarily controlled by the ventilation and air conditioning system. Temperature control within the track area is mainly achieved through traditional upper and lower heat dissipation systems. During normal operation, the onboard air conditioning condensers and undercarriage heat dissipation components release a significant amount of heat when the train is stopped. This heat is promptly removed through ventilation ducts and outlets on the top of the tracks and under the platforms, connected to heat dissipation fans located in the machine room, effectively controlling the temperature within the track area. However, existing research indicates significant uneven airflow velocity at the various heat dissipation vents in the current track area upper heat dissipation system. Generally, the airflow velocity is higher near the heat dissipation fan and lower closer to the track area, leading to higher temperature rises in the track area during summer, sometimes exceeding 40°C. Excessively high track area air temperatures can cause the train's air conditioning condensers to stop working, seriously affecting the safe operation of urban rail transit. Summary of the Invention

[0003] The purpose of this invention is to propose a method to control the temperature of the track zone and avoid the extreme condition of condenser shutdown.

[0004] To achieve the above objectives, the technical solution of the present invention provides a method for controlling the exhaust temperature of the condenser in the upper section of the subway train during reduced-frequency operation. The method is characterized by using a temperature sensor to monitor the exhaust temperature at the exhaust vent of the upper exhaust system in the track area in real time. When the obtained exhaust temperature is higher than a preset temperature threshold, the condenser of the currently arriving train is controlled to operate at a reduced frequency to reduce the heat released by the condenser, thereby improving the thermal environment of the upper space of the currently arriving train and preventing the condenser of the currently arriving train from tripping.

[0005] Furthermore, the temperature sensor is positioned at the exhaust vent of the heat dissipation system on the track area of ​​the subway station.

[0006] Furthermore, when setting the temperature threshold, the premise is that the air temperature near the train condenser is not higher than 40°C.

[0007] Furthermore, when the temperature sensor detects that the exhaust air temperature at the exhaust air outlet of the heat dissipation system on the track area is higher than the temperature threshold, it generates control information and sends the control information to the train that is about to enter the station, and the condenser of the train operates at a reduced frequency during the train's stop at the station.

[0008] Furthermore, when the condenser operates at reduced frequency, the degree of frequency reduction is adjusted according to the specific magnitude by which the exhaust air temperature at the exhaust vent of the heat dissipation system on the track area exceeds the temperature threshold. The adjustment formula is as follows:

[0009]

[0010] In the formula, P is the frequency reduction amplitude of the condenser, and T p T represents the exhaust air temperature at the exhaust air outlet of the heat dissipation system in the track area. lim For the set temperature threshold, T S The average background temperature of the tunnel section.

[0011] Furthermore, when the condenser operates at reduced frequency, the degree of frequency reduction is based on the premise that it does not affect the thermal comfort of passengers inside the train during the current train stop.

[0012] The method provided by this invention controls the track area temperature by appropriately reducing the frequency of the condenser's operation during subway train stops when the monitored air temperature in the track area is too high, thus preventing the train condenser from shutting down due to excessively high track area air temperature. This invention primarily optimizes the subway train condenser's operating strategy to control the exhaust temperature in the tunnel section, thereby preventing the train condenser from shutting down in summer due to excessively high intake air temperature. Attached Figure Description

[0013] Figure 1 A 3D model of the station's track area;

[0014] Figure 2 Temperature distribution cloud map of the track area before the train condenser is operated at reduced frequency;

[0015] Figure 3 Temperature distribution cloud map of the track area after the train condenser is operated at a reduced frequency. Detailed Implementation

[0016] The present invention will be further illustrated below with reference to specific embodiments. It should be understood that these embodiments are for illustrative purposes only and are not intended to limit the scope of the invention. Furthermore, it should be understood that after reading the teachings of this invention, those skilled in the art can make various alterations or modifications to the invention, and these equivalent forms also fall within the scope defined by the appended claims.

[0017] The present invention discloses a method for controlling the upper exhaust heat temperature of the condenser in a subway train during frequency reduction operation, which includes the following:

[0018] Temperature sensors installed at the exhaust vents of the heat dissipation system on the track area of ​​a subway station are used to monitor the exhaust air temperature in real time. When the detected exhaust air temperature exceeds a set temperature threshold, control information is generated and sent to the stopped train. In this embodiment of the invention, the exhaust air temperature threshold at the heat dissipation vents on the track area is set based on the premise that the air temperature near the train's condenser does not exceed 40°C. During the current train's stop at the station, its condenser operates at a reduced frequency according to the control information, without affecting the thermal comfort of passengers inside the train; after the current train leaves the station, its condenser resumes normal operating frequency according to the control information. When the next train stops, the exhaust air temperature at the upper exhaust vent of the heat dissipation system is compared with the exhaust air temperature monitored when the previous train stopped. If the current exhaust air temperature is higher than that of the previous train, the condenser frequency reduction of the current train can be appropriately increased without affecting the thermal comfort of passengers. If the current exhaust air temperature is lower than that of the previous train, the current condenser operating frequency is maintained. The condenser of the current train will only resume normal operation during the stop when the exhaust air temperature at the upper exhaust vent of the heat dissipation system in the track area is detected to be lower than the set upper temperature threshold.

[0019] A more preferred implementation is that, in the above scheme, the degree of frequency reduction operation of the train condenser can be adjusted according to the specific magnitude by which the exhaust air temperature at the exhaust vent of the heat dissipation system on the track area exceeds the set temperature threshold. The adjustment formula is as follows:

[0020]

[0021] In the formula, P is the frequency reduction amplitude of the condenser, and T p T represents the exhaust air temperature at the exhaust air outlet of the heat dissipation system in the track area. lim For the set temperature threshold, T S The average background temperature of the tunnel section.

[0022] A more preferred implementation is that, in the above scheme, the frequency reduction operation of the train condenser should be based on the premise that it does not affect the thermal comfort of passengers inside the train during the train's stop.

[0023] To visually demonstrate the effect of reduced-frequency operation of the train's condenser on tunnel temperature control, a model of the station's track area was established using a standard station on Fuzhou Metro Line 1 as a reference. Numerical simulations were used to compare and demonstrate the effect of reduced-frequency operation on tunnel temperature control. The station's track area has a cross-sectional dimension of 5.6m × 3.4m and a total length of 150m. The train uses a 6-car B-type train with dimensions of 3.7m × 2.55m × 120m. The air conditioning condenser's heat dissipation vents are located on the top of the train, measuring 1000mm × 500mm, simplified to 12 rectangular air outlets. The top-mounted heat dissipation method uses a single-sided supply and single-sided exhaust jet flow. The supply and exhaust vents are 3.2m × 1m in size, located at both ends of the station's track area, with a supply air volume of 40m³ / h. 3 / s, exhaust volume 40m³ 3 The established 3D model is attached. Figure 1 As shown.

[0024] The interface with the atmosphere is set as the pressure inlet boundary, i.e., the inlet and outlet at both ends of the station's track area. The temperature is selected as the average monthly temperature of the hottest month in summer, 29.2℃, and the pressure is the local atmospheric pressure. According to monitoring data provided by the subway operating company, the train condenser exhaust temperature is 44.6℃, and the condenser exhaust volume is 25776 m³ / h. 3 Therefore, the condenser vent was set to an outlet with a temperature of 44.6℃ and a velocity of 7.16 m / s. The supply vent was set to an outlet with a temperature of 29.2℃ and a velocity of 12.5 m / s, and the exhaust vent was set to an inlet with a temperature equal to the indoor ambient temperature and a velocity of 12.5 m / s. An adaptable unstructured mesh was used for mesh generation, and mesh independence verification was completed. After setting the boundary conditions and generating the mesh, the simulation could begin.

[0025] Figure 2 This is a simulated temperature distribution cloud map of the track area before the trains stop at the station and operate at reduced frequency. Figure 2 It can be seen that, under the baseline operating conditions, the air temperature gradually increases from the air inlet to the exhaust outlet. The average air temperature in the middle and rear half of the station track area is approximately 42℃, and in some rear areas, the air temperature even exceeds 42℃. In these areas, the excessively high air temperature can cause the train's air conditioning condenser to stop working, seriously affecting the safe operation of urban rail transit. Simultaneously, it can be observed that the temperature at the upper heat exhaust outlet is approximately 41-42℃, exceeding the set upper limit of the condenser inlet air temperature threshold. To effectively control the air temperature in the section, the condenser is operated at a reduced frequency during train stops, and the simulation is repeated.

[0026] Figure 3 Temperature distribution cloud map of the track area after reducing the frequency of the condenser of a stopped train to 80% and then running. Figure 3It can be seen that after the train condenser frequency was reduced, the area near the condenser outlet with a temperature exceeding 41℃ decreased compared to before the frequency reduction. This is because the airflow velocity of the train's air conditioning condenser decreased, resulting in less heat release and transfer to the surrounding air. The excessive air temperature in the area above the rear of the train and near the exhaust vent was significantly improved, with the temperature dropping from approximately 42-43℃ in condition two (transmitter exhaust speed) to approximately 39-40℃ in condition six (synchronous transmitter exhaust speed and condenser airflow speed). Before the frequency reduction, the average temperature of a typical section of the track area was 38.04℃; after the frequency reduction, it was 36.68℃, a decrease of 1.36℃. This indicates that the frequency reduction of the condenser's outlet speed effectively alleviated the localized high temperature problem.

Claims

1. A method for controlling the upper exhaust heat temperature of the condenser in a subway train during frequency reduction operation, characterized in that, Temperature sensors are used to monitor the exhaust air temperature at the exhaust vents of the heat dissipation system on the track area in real time. When the obtained exhaust air temperature exceeds a preset temperature threshold, the condenser of the currently arriving train is controlled to operate at a reduced frequency to decrease the heat released by the condenser, thereby improving the thermal environment above the currently arriving train and preventing the condenser from tripping. When setting the temperature threshold, the premise is that the air temperature near the train condenser is not higher than 40°C. When the condenser operates at reduced frequency, the degree of frequency reduction is based on the premise that it does not affect the thermal comfort of passengers inside the train during the current stop. The degree of frequency reduction is adjusted according to the specific amount by which the exhaust air temperature at the exhaust vent of the heat dissipation system on the track area exceeds the temperature threshold. The adjustment formula is as follows: In the formula, For the frequency reduction of the condenser, The exhaust air temperature at the exhaust air outlet of the heat dissipation system in the track area. The set temperature threshold, The average background temperature of the tunnel section.

2. The method for controlling the upper exhaust heat temperature of the condenser in a subway train during frequency reduction operation according to claim 1, characterized in that, The temperature sensor is located at the exhaust vent of the heat dissipation system on the track area of ​​the subway station.

3. The method for controlling the upper exhaust heat temperature of the condenser in a subway train during frequency reduction operation according to claim 1, characterized in that, When the temperature sensor detects that the exhaust air temperature at the exhaust air outlet of the heat dissipation system on the track area is higher than the temperature threshold, it generates control information and sends the control information to the train that is about to enter the station. During the train's stop at the station, its condenser operates at a reduced frequency.

Images