A tunnel morning and evening ventilation control system and method

Abstract

The present invention relates to a tunnel morning and evening ventilation control system and method, comprising an interval tunnel ventilation system and a variable frequency control system. The variable frequency control system comprises a controller, a frequency converter, and a human-machine interface. The human-machine interface is connected to the controller, which is connected to the frequency converter, which is connected to the tunnel fan of the interval tunnel ventilation system. The human-machine interface is used to allow an operator to set the tunnel air volume and operating time for the morning and evening tunnels and transmit the set information to the controller. The controller calculates the fan operating frequency f required for tunnel morning and evening ventilation at a given time t based on the relationship between air volume and frequency. Under the morning and evening ventilation conditions, the frequency converter controls the tunnel fan to ventilate at the calculated frequency f and controls the tunnel fan to stop operating after t hours of operation. The present invention automatically adjusts the fan operating frequency and controls fan operation based on the user-set morning and evening ventilation air volume and operating time, ensuring ventilation requirements while minimizing ventilation energy consumption.

Description

Technical Field

[0001] The present invention belongs to the technical field of subway tunnel ventilation systems, and in particular relates to a tunnel morning and evening ventilation control system and method. Background Art

[0002] With the continuous advancement of urbanization in my country, urban populations are increasing, and urban road traffic pressure is increasing. Subway transportation systems have gradually become an important means of alleviating traffic pressure in major cities. The tunnel ventilation system is a vital component in supporting the normal operation of subway transportation systems. The tunnel ventilation system is mainly responsible for morning and evening ventilation within the tunnel, as well as ventilation and smoke exhaust in the event of fires, blockages, and other accidents.

[0003] The tunnel ventilation system operates for half an hour each morning and evening before and after trains depart. This ventilation system primarily removes heat and provides ventilation in subway tunnels. Morning operations remove pollutants generated by overnight maintenance, while evening operations remove pollutants generated by daytime train operations and excess heat not removed by piston air. Furthermore, these morning and evening ventilation runs allow for the operational status of ventilation equipment to be verified, ensuring timely deployment in the event of an emergency.

[0004] Currently, many scholars studying tunnel ventilation system strategies focus on heat removal ventilation strategies for trains in operation. Patent application number CN201710031855 proposes a control method that monitors tunnel air temperature and outdoor temperature, calculates the amount of heat dissipated by the train in the tunnel, adjusts the heat removal fan operating mode, and combines this with heat recovery to achieve system energy conservation. However, the number of passengers carried by trains at each station varies greatly, and the temperature in the tunnel fluctuates widely, which can lead to inaccurate control. Patent application number CN201910122820 proposes a method for dynamically controlling the tunnel based on real-time wind pressure in the tunnel. This method constructs a transfer function between tunnel wind pressure and fan operating frequency, combining the real-time wind pressure in the tunnel with the fan operating frequency to achieve dynamic fan operation control. Including the two aforementioned inventions, many current studies on subway tunnel ventilation systems focus on the operational control of ventilation systems during train operation, while few studies have examined tunnel fan control strategies for morning and evening ventilation.

[0005] Research has shown that tunnel fans typically have a high rated power. During morning and evening ventilation, tunnel fans operate at a commercial frequency, resulting in high power consumption. The power consumption for morning and evening ventilation in a 25-station tunnel section of a subway line is approximately 1.5 million kWh. Research and testing have shown that when tunnel fans operate in the evening to introduce cool air, the tunnel temperature drops significantly. After the evening ventilation concludes, the temperature rises and remains stable. The heat removed by evening ventilation exceeds the required waste heat removal. CO2 and particulate matter concentrations are primarily related to passenger volume and traffic conditions. After the evening rush hour passes, CO2 concentrations begin to decline. By the time tunnel fans begin operating in the evening, CO2 concentrations have already dropped to a low level (400 ppm). After trains stop running, suspended particulate matter in the tunnel gradually settles, reaching a low level (15 μg / m³) by the time tunnel fans resume operation in the evening. While ensuring waste heat removal and air quality in the evening sections of the tunnel, tunnel fans can be controlled with variable frequency drive to achieve energy savings. Summary of the Invention

[0006] The purpose of the present invention is to overcome the defects of the prior art and provide a tunnel morning and evening ventilation control system and method, which automatically adjusts the fan operating frequency and controls the fan operation according to the user-set morning and evening ventilation air volume and operating time, ensuring ventilation needs while minimizing ventilation energy consumption.

[0007] The technical solution of the present invention is implemented as follows: The present invention discloses a tunnel morning and evening ventilation control system, including an interval tunnel ventilation system and a frequency conversion control system. The frequency conversion control system includes a controller, a frequency converter and a human-computer interaction interface. The human-computer interaction interface is connected to the controller, the controller is connected to the frequency converter, and the frequency converter is connected to the tunnel fan of the interval tunnel ventilation system.

[0008] The tunnel morning and evening ventilation control system of the present invention further includes a BAS system, which is connected to the controller.

[0009] The human-computer interaction interface is used for the operator to set the tunnel air volume and operating time in the morning and evening, and transmit the set information to the controller. The controller calculates the fan operating frequency f required for tunnel ventilation in the morning and evening at a given time t based on the relationship between air volume and frequency. Under the morning and evening ventilation conditions, the frequency converter controls the tunnel fan to ventilate at the calculated frequency f, and controls the tunnel fan to stop running after t hours of operation;

[0010] The relationship between air volume and frequency is:

[0011]

[0012] Where Q0 is the actual ventilation volume under the working frequency of the tunnel fan; Q is the ventilation volume of the tunnel fan; f0 is the working frequency of the tunnel fan; f is the operating frequency of the tunnel fan in the morning and evening ventilation conditions; and t is the time the fan needs to run.

[0013] The present invention discloses a method for controlling morning and evening ventilation in a tunnel, comprising the following steps:

[0014] S1) The control system determines whether the tunnel is in an accident condition. If so, the control system controls the tunnel fan to operate in a power frequency mode during morning and evening ventilation, and executes step S21); if not, the control system controls the tunnel fan to operate in a variable frequency mode during morning and evening ventilation, and executes step S22);

[0015] S21) Whether the tunnel ventilation requirement is met, if so, the tunnel fan is controlled to stop running, if not, the tunnel fan is controlled to continue running in power frequency mode;

[0016] S22) The controller calculates the fan operating frequency f required at a given time t for morning and evening ventilation of the tunnel based on the tunnel ventilation volume setting and the relationship between air volume and frequency. Under the morning and evening ventilation conditions, the frequency converter controls the tunnel fan to ventilate at the calculated frequency f for t hours, and determines whether the given time has been reached. If not, the tunnel fan is controlled to continue to execute the frequency conversion mode of S22). If so, the tunnel fan is controlled to stop running.

[0017] Furthermore, the relationship between air volume and frequency is:

[0018]

[0019] Where Q0 is the actual ventilation volume under the working frequency of the tunnel fan; Q is the ventilation volume of the tunnel fan; f0 is the working frequency of the tunnel fan; f is the operating frequency of the tunnel fan in the morning and evening ventilation conditions; and t is the time the fan needs to run.

[0020] Furthermore, a human-computer interaction interface is used to set the tunnel air volume and operating time in the morning and evening.

[0021] Furthermore, the control system determines whether the tunnel is in an accident condition, specifically including: the control system collects firefighting conditions and train operation conditions in the tunnel through the BAS system, and determines whether the tunnel is in an accident condition.

[0022] The present invention has at least the following beneficial effects: It addresses the common practice of using power-frequency tunnel fans for morning and evening ventilation in subway tunnels. By replacing the traditional power-frequency operation mode for tunnel fans during morning and evening ventilation, the present invention employs variable-frequency operation for these conditions. Based on user-defined morning and evening ventilation air volumes and operating times, the present invention automatically adjusts the fan operating frequency to control fan operation, ensuring ventilation requirements while minimizing ventilation energy consumption. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0024] Figure 1 A block diagram of the principle of a tunnel morning and evening ventilation control system provided by an embodiment of the present invention;

[0025] Figure 2 A flow chart of a method for controlling morning and evening ventilation in a tunnel provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0026] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0027] Example 1

[0028] See also Figure 1 and Figure 2 , an embodiment of the present invention provides a tunnel morning and evening ventilation control system, including an interval tunnel ventilation system and a frequency conversion control system, wherein the interval tunnel ventilation system includes a ventilation shaft 1, a tunnel fan 2, and an interval tunnel 3, and the frequency conversion control system includes a controller 41, a frequency converter 42, circuit breakers, thermal relays and other strong electrical components 43, a human-computer interaction interface 44, and a power supply for supplying power to the entire frequency conversion control system. The controller is connected to the human-computer interaction interface 44, and the air volume and fan operating time required for morning and evening ventilation are set through the human-computer interaction interface. The controller 41 is connected to the frequency converter 42, and the frequency converter 42 is connected to the tunnel fan 2. The frequency converter controls the operation of the tunnel fan according to the frequency calculated by the controller. Under the morning and evening ventilation conditions, the tunnel fan runs for t hours (set time) according to the calculated frequency and then stops.

[0029] The tunnel morning and evening ventilation control system of the present invention further includes a BAS system 5 , which is connected to a controller 41 .

[0030] The human-computer interaction interface is used for the operator to set the tunnel air volume and operating time in the morning and evening, and transmit the set information to the controller. The controller calculates the fan operating frequency f required for tunnel ventilation in the morning and evening at a given time t based on the relationship between air volume and frequency. Under the morning and evening ventilation conditions, the frequency converter controls the tunnel fan to ventilate at the calculated frequency f, and controls the tunnel fan to stop running after t hours of operation;

[0031] The relationship between air volume and frequency is:

[0032]

[0033] Where, Q0(m 3 / h) is the actual ventilation air volume of the tunnel fan under the working frequency condition. The actual ventilation air volume under the working frequency condition Q0 is the rated air volume of the fan under the working frequency, which is provided by the fan manufacturer; Q(m 3 ) is the ventilation air volume of the tunnel fan, which is set manually according to the ventilation demand; f0 (Hz) is the operating frequency of the tunnel fan, and the parameters of the tunnel fan operating frequency f0 are provided by the fan manufacturer; f (Hz) is the operating frequency of the tunnel fan in the morning and evening ventilation conditions; t (h) is the time the fan needs to run.

[0034] In the event of a blockage or fire, the operating conditions of accident ventilation and smoke exhaust are different from the normal ventilation conditions. The tunnel fan needs to be operated at a rated frequency to ensure the air volume and cross-sectional wind speed in the tunnel.

[0035] Example 2

[0036] See also Figure 1 and Figure 2 The embodiment of the present invention discloses a method for controlling morning and evening ventilation in a tunnel, comprising the following steps:

[0037] S1) The control system determines whether the tunnel is in an accident condition. If so, the control system controls the tunnel fan to operate in a power frequency mode during morning and evening ventilation, and executes step S21). If not, the control system changes the conventional power frequency operation mode of the tunnel fan during morning and evening ventilation to control the tunnel fan to operate in a variable frequency mode during morning and evening ventilation (step S22).

[0038] S21) Whether the tunnel ventilation requirement is met, if so, the tunnel fan is controlled to stop running, if not, the tunnel fan is controlled to continue running in power frequency mode;

[0039] S22) operates in a variable frequency mode, specifically including: the controller calculates the fan operating frequency f required for morning and evening ventilation of the tunnel at a given time t according to the set tunnel ventilation volume Q and the relationship between air volume and frequency; under the morning and evening ventilation conditions, the frequency converter controls the tunnel fan to ventilate at the calculated frequency f, runs for t hours, and determines whether the given time has been reached; if not, controls the tunnel fan to continue to execute the variable frequency mode of S22); if so, controls the tunnel fan to stop running.

[0040] When the tunnel is in an accident condition, if it is a blockage condition, the cross-sectional wind speed and the temperature at the blockage point must meet the regulatory requirements. If it is a fire, the cross-sectional wind speed at the fire point must meet the regulatory requirements and exceed the critical wind speed for fire.

[0041] The relationship between the actual fan air volume and fan frequency should be determined through actual measurement and debugging. The fan operating frequency during the actual operation of morning and evening ventilation is calculated by the number of tunnel air changes. The tunnel ventilation frequency is 3 times / h. For the morning and evening ventilation conditions, the set tunnel ventilation volume, that is, the fan variable frequency operation air volume, needs to meet 1.5 tunnel air changes. Then there is

[0042] Q=1.5SL (1)

[0043] Where, Q(m 3 ) is the ventilation volume of the tunnel fan; S (m 2 ) and L(m) are the ventilation cross-sectional area of ​​the interval tunnel and the length of the single-side tunnel respectively.

[0044] Furthermore, based on the relationship between air volume and frequency, the fan operating frequency required at a given time during tunnel ventilation in the morning and evening can be calculated. The relationship between air volume and frequency is:

[0045]

[0046] Where, Q0(m 3 / h) is the actual ventilation air volume of the tunnel fan under the working frequency condition. The actual ventilation air volume under the working frequency condition Q0 is the rated air volume of the fan under the working frequency, which is provided by the fan manufacturer; Q(m 3 ) is the ventilation air volume of the tunnel fan, which is set manually according to the ventilation demand; f0 (Hz) is the operating frequency of the tunnel fan, and the parameters of the operating frequency f0 of the tunnel fan are provided by the fan manufacturer; f (Hz) is the operating frequency of the tunnel fan in the morning and evening ventilation conditions; t is the time the fan needs to run, in hours.

[0047] Furthermore, a human-computer interaction interface is used to set the tunnel air volume and operating time in the morning and evening.

[0048] Furthermore, the control system determines whether the tunnel is in an accident condition, specifically including: the control system collects firefighting conditions and train operation conditions in the tunnel through the BAS system, and determines whether the tunnel is in an accident condition.

[0049] The present invention aims to optimize the energy conservation of existing tunnel ventilation systems and proposes a new control system and method for morning and evening ventilation of tunnels. The main function of morning and evening ventilation is to remove heat and ventilate subway tunnels. Morning operation can remove pollutants generated by nighttime maintenance in the tunnel, and evening operation can remove pollutants generated by daytime train operation and residual heat not removed by piston wind. In addition, the operation of ventilation equipment in the morning and evening can be checked to ensure that it can be put into use in time when an accident occurs. In view of the current situation that tunnel fans generally adopt industrial frequency ventilation for morning and evening ventilation, the control system and method introduce a variable frequency control method and cooperate with the BAS system. While the tunnel fans are controlled by variable frequency, the operating air volume of the tunnel fans is manually input, thereby reducing the energy consumption of the daily morning and evening ventilation of the interval tunnel ventilation system. Under the premise of ensuring the thermal and humid environment and air quality of the subway interval tunnel, the purpose of saving the energy consumption of morning and evening ventilation operation can be achieved. The new control system and method for tunnel morning and evening ventilation of the present invention are suitable for subway interval tunnel ventilation systems.

[0050] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A method for controlling tunnel ventilation in the morning and evening, characterized in that: The steps include: S1) The controller determines whether the tunnel is in an accident condition. If so, the controller controls the tunnel fan to operate in a power frequency mode during morning and evening ventilation, executing step S21). If not, the controller controls the tunnel fan to operate in a variable frequency mode during morning and evening ventilation, executing step S22). S21) Whether the tunnel ventilation requirement is met, if so, the tunnel fan is controlled to stop running, if not, the tunnel fan is controlled to continue running in the power frequency mode; S22) The controller calculates the ventilation frequency of the tunnel at a given time based on the tunnel ventilation volume setting and the relationship between the air volume and frequency. t Required fan operating frequency In the morning and evening ventilation conditions, the inverter controls the tunnel fan at a frequency of Ventilation, operation t hours, determine whether the given time has been reached, if not, control the tunnel fan to continue to execute the variable frequency mode of S22), if so, control the tunnel fan to stop running; The relationship between air volume and frequency is: ； Where, is the actual ventilation air volume of the tunnel fan under the working frequency condition; The ventilation air volume of the tunnel fan; is the power frequency of the tunnel fan; The fan operating frequency during morning and evening ventilation of the tunnel; t The time the fan needs to run.

2. The method for controlling tunnel ventilation in the morning and evening according to claim 1, characterized in that: A human-computer interaction interface is used to set the tunnel air volume and operating time in the morning and evening.

3. The method for controlling tunnel ventilation in the morning and evening according to claim 1, characterized in that: The controller determines whether the tunnel is in an accident condition, specifically including: the controller collects the fire situation and train operation status in the tunnel through the BAS system, and determines whether the tunnel is in an accident condition.

4. A tunnel morning and evening ventilation control system, characterized by: It includes an interval tunnel ventilation system and a variable frequency control system, wherein the variable frequency control system includes a controller, a frequency converter and a human-computer interaction interface, wherein the human-computer interaction interface is connected to the controller, the controller is connected to the frequency converter, and the frequency converter is connected to the tunnel fan of the interval tunnel ventilation system; The human-computer interaction interface is used for the operator to set the morning and evening tunnel air volume and operating time, and transmit the set information to the controller, and the controller is used to execute the tunnel morning and evening ventilation control method as described in any one of claims 1-3.

5. The tunnel morning and evening ventilation control system according to claim 4, characterized in that: Also included is a BAS system connected to the controller.

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