Relay fan control method, device and controller

Abstract

The application provides a relay fan control method, device and controller. The method comprises: obtaining an actual measured pressure of a wind warehouse in the case that a relay fan is started; determining a current frequency of the relay fan according to a difference between the actual measured pressure and a preset reasonable pressure; and controlling the relay fan to operate according to the current frequency. In the embodiment of the application, the frequency of the relay fan is adjusted according to the internal pressure of the wind warehouse at any time, so that the internal pressure of the wind warehouse is dynamically balanced in a proper range, without the need for on-site adjustment or manual intervention. The relay fan can realize flexible air volume transmission, so that air supply is realized at low cost and low energy consumption, air volume waste is avoided, the risk of recycling of dirty air is avoided, and the air supply efficiency is improved.

Description

Technical Field

[0001] This invention relates to the field of tunnel ventilation technology, and more specifically, to a relay fan control method, device, and controller. Background Technology

[0002] In traditional tunnel excavation, ventilation is often achieved through forced ventilation. For long-distance tunnel excavation, high-pressure, high-flow-rate fans and large-diameter, high-strength ventilation ducts are required. However, the on-site power supply is difficult to meet the requirements of high-power fans, and the procurement and maintenance costs of fans and ducts are also very high.

[0003] For tunnels that are long or have a small diameter, one or more "relay" fans are typically used. This is to reduce the air pressure in each section of the ductwork, especially at the tunnel entrance. Using relay fans reduces the pressure on the upstream fans, which automatically translates to reduced power consumption. However, this approach presents a risk of secondary pollution from contaminated air within the tunnel. Because the actual airflow from the fans and the ductwork is uncertain and fluctuates, the upstream ductwork cannot be directly connected to the relay fan. To ensure that contaminated return air from the tunnel is not drawn into the relay fan, the air supply at the end of the upstream ductwork must be greater than the required airflow from the relay fan. This reduces the advantages of lower power consumption from the relay fan and lower airflow from the tunnel entrance fan, negating or even eliminating the benefits of using relay fans.

[0004] Therefore, existing tunnel ventilation methods suffer from high costs, high energy consumption, and secondary pollution from polluted air. Summary of the Invention

[0005] To address the aforementioned problems, this invention provides a relay fan control method, wherein the relay fan is connected to a ventilation duct, and the method includes: acquiring the measured pressure of the air chamber when the relay fan is started; determining the current frequency of the relay fan based on the difference between the measured pressure and a preset reasonable pressure; and controlling the operation of the relay fan based on the current frequency.

[0006] Optionally, the air chamber is equipped with an overpressure safety valve and / or an underpressure safety valve; the method further includes: if the measured pressure is greater than a preset pressure upper limit, controlling the overpressure safety valve to open until the measured pressure drops to a safe pressure range; and / or, if the measured pressure is less than a preset pressure lower limit, controlling the underpressure safety valve to open until the measured pressure rises to a safe pressure range.

[0007] Optionally, the method further includes: if the measured pressure is greater than a preset upper pressure limit, controlling the relay fan to operate at a preset higher frequency; and / or, if the measured pressure is less than a preset lower pressure limit, controlling the relay fan to operate at a preset lower frequency.

[0008] Optionally, determining the current frequency of the relay fan based on the difference between the measured pressure and the preset reasonable pressure includes: calculating the difference between the measured pressure and the preset reasonable pressure to obtain the current difference; calculating the frequency increase value based on the current difference, the difference between the current difference and the previous time point, and the sum of the current differences at each historical time point; the current difference is positively correlated with the frequency increase value, and the sum of the current differences at each historical time point is positively correlated with the frequency increase value; when the current difference is greater than the difference at the previous time point, the difference between the current difference and the previous time point is positively correlated with the frequency increase value, and when the current difference is less than the difference at the previous time point, the difference between the current difference and the previous time point is negatively correlated with the frequency increase value; summing the frequency increase value with the initial frequency to calculate the current frequency of the relay fan; the difference at the previous time point is the difference between the measured pressure at the previous time point and the preset reasonable pressure, and the current difference at each historical time point is the difference between the measured pressure at each historical time point and the preset reasonable pressure.

[0009] Optionally, the formula for calculating the current frequency of the relay fan is as follows:

[0010]

[0011] e t =P t -P

[0012] Where P is the preset reasonable pressure, P t f is the measured pressure inside the wind tunnel at time t, and f is the initial frequency of the relay wind turbine. t k is the current frequency of the relay wind turbine at time t. p It is the proportionality coefficient, k i It is the integral coefficient, k d These are the differential coefficients.

[0013] Optionally, before controlling the relay fan to operate according to the current frequency, the method further includes: determining whether the current frequency is within a preset frequency reasonable range; if so, then performing the step of controlling the relay fan to operate according to the current frequency.

[0014] Optionally, the overpressure safety valve is equipped with a micro switch, and the underpressure safety valve is equipped with a micro switch; the method further includes: determining the open / closed state of the overpressure safety valve and whether the measured pressure is greater than a preset pressure upper limit based on the output signal of the micro switch; or, determining the open / closed state of the underpressure safety valve and whether the measured pressure is less than a preset pressure lower limit based on the output signal of the micro switch.

[0015] Optionally, the method further includes: when the ventilation duct stops supplying air, controlling the relay fan to shut down after the upstream fan of the ventilation duct is shut down.

[0016] This invention provides a relay fan control device, comprising: a pressure acquisition module for acquiring the measured pressure of the air chamber when the relay fan is started; a frequency determination module for determining the current frequency of the relay fan based on the difference between the measured pressure and a preset reasonable pressure; and an operation control module for controlling the operation of the relay fan according to the current frequency.

[0017] This invention provides a relay fan controller, which is connected to a pressure sensor, a safety valve, a relay fan frequency converter, and a network module. The pressure sensor and the safety valve are both located within a fan housing connected to the relay fan. The pressure sensor detects the pressure within the fan housing, and the safety valve opens when the pressure within the fan housing exceeds a preset upper pressure limit or falls below a preset lower pressure limit. The network module transmits the pressure within the fan housing and the current frequency of the relay fan to a designated terminal or platform. The controller executes the aforementioned relay fan control method.

[0018] The embodiments of the present invention can adjust the frequency of the relay fan at any time according to the internal pressure of the air chamber, so that the internal pressure of the air chamber is dynamically balanced within an appropriate range without on-site adjustment or manual intervention. The relay fan can achieve flexible air volume transmission, thereby achieving air supply at low cost and low energy consumption, without air volume waste and avoiding the risk of recirculation of polluted air, thus improving air supply efficiency. Attached Figure Description

[0019] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0020] Figure 1 This is a schematic diagram of an exemplary scenario of the relay air supply scheme for tunnel ventilation ducts in an embodiment of the present invention;

[0021] Figure 2 This is a schematic flowchart of a relay fan control method according to an embodiment of the present invention;

[0022] Figure 3 This is a schematic diagram of the control principle of the relay fan in an embodiment of the present invention;

[0023] Figure 4 This is a schematic diagram of a relay fan control device according to an embodiment of the present invention. Detailed Implementation

[0024] To make the above-mentioned objects, features, and advantages of the present invention more apparent and understandable, specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

[0025] This invention provides a solution for automatically adjusting the frequency of relay fans based on the internal pressure of the ventilation chamber. Only the operation of the ventilation fan at the tunnel entrance needs to be controlled to ensure the air volume delivered to the working face via the duct. The relay fans adjust their rotation speed according to the supplied air pressure; this control is automatic and requires no on-site adjustment (or other manual intervention). Each relay fan can achieve 100% flexible air volume transmission, eliminating air volume waste and avoiding the risk of recirculating polluted air. Tunnel ventilation can achieve maximum efficiency in a single operation.

[0026] See Figure 1 The diagram shows an exemplary scenario of a tunnel ventilation duct relay air supply scheme, which includes a main fan, a relay air chamber, a relay fan, and a programmable logic controller (PLC). The main fan is connected to the relay air chamber via a duct, and the relay air chamber is connected to the relay fan. The relay fan delivers fresh air to the working environment via the duct.

[0027] The overall working face environment parameters are fed back to the main fan, which adjusts its operating status based on these parameters to ensure that the working face environment meets construction requirements. The PLC can acquire the air chamber pressure and safety valve status of the relay air chamber, as well as control the frequency of the relay fan.

[0028] Figure 2 This is a schematic flowchart of a relay fan control method according to an embodiment of the present invention, which can be applied to a controller for connecting relay fans. Exemplarily, the relay fan is connected to a ventilation duct, which may include an upstream duct, a ventilation chamber, and a downstream duct connected in sequence. The relay fan can be connected between the ventilation chamber and the downstream duct. The method includes:

[0029] S202, when the relay fan is started, obtains the measured pressure of the wind chamber.

[0030] A pressure sensor is installed inside the air chamber, which can collect the real-time measured pressure of the air chamber. After the main fan starts, the backup fan can be started. With the backup fan running, the controller can obtain the measured pressure of the air chamber through the pressure sensor.

[0031] S204. Determine the current frequency of the relay fan based on the difference between the measured pressure and the preset reasonable pressure.

[0032] In this embodiment, it is necessary to determine whether the difference between the actual measured pressure and the preset reasonable pressure increases or decreases, and to calculate the frequency increase value based on the magnitude of this difference. The controller calculates the new frequency based on the frequency increase value and the preset frequency of the relay fan (e.g., the minimum operating frequency of the relay fan).

[0033] Specifically, the current frequency of the relay fan can be calculated as follows:

[0034] First, the difference between the measured pressure and the preset reasonable pressure is calculated to obtain the current difference value. When the preset frequency is the minimum operating frequency of the relay fan, the measured pressure is generally greater than the preset reasonable pressure.

[0035] Secondly, the frequency increase value is calculated based on the current difference, the difference between the current difference and the previous time, and the sum of the current differences at each historical time.

[0036] The previous time difference is the difference between the measured pressure and the preset reasonable pressure at the previous time, while the current difference at each historical time is the difference between the measured pressure and the preset reasonable pressure at that historical time. This current difference is positively correlated with the frequency increase. The current difference represents the difference between the measured pressure and the preset reasonable pressure. The larger the difference, the greater the frequency needs to be increased, thereby controlling the relay fan to deliver the air in the air chamber to the downstream air duct as quickly as possible, and correspondingly reducing the measured pressure of the air chamber.

[0037] The sum of the current differences at each historical moment is positively correlated with the frequency increase. The sum of the current differences at each historical moment represents the cumulative value of the measured pressure and the preset reasonable pressure at each historical moment. The larger the cumulative value, the more likely there is a deviation between the measured pressure and the preset reasonable pressure, and the more persistent the deviation is. The larger the cumulative value, the greater the frequency needs to be increased.

[0038] When the current difference is greater than the difference at the previous time step, the difference between the current and previous time step values ​​is positively correlated with the increase in frequency. In this case, the deviation between the measured pressure and the preset reasonable pressure is widening, and the frequency that needs to be increased is greater. When the current difference is less than the difference at the previous time step, the difference between the current and previous time step values ​​is negatively correlated with the increase in frequency. In this case, the deviation between the measured pressure and the preset reasonable pressure is narrowing, and the frequency that needs to be increased is smaller.

[0039] Then, the frequency increase is summed with the initial frequency to calculate the current frequency of the relay fan.

[0040] S206, control the operation of the relay fan according to the current frequency mentioned above.

[0041] The relay fan control method provided in this invention can adjust the frequency of the relay fan at any time according to the internal pressure of the air chamber, so that the internal pressure of the air chamber is in dynamic balance within an appropriate range. No on-site adjustment or manual intervention is required. The relay fan can achieve flexible air volume transmission, thereby achieving air supply at low cost and low energy consumption, without air volume waste and avoiding the risk of recirculation of polluted air, thus improving air supply efficiency.

[0042] For safety reasons regarding the internal pressure of the air chamber, overpressure and underpressure safety valves can be installed on the air chamber. When the internal pressure of the air chamber exceeds the upper limit, the overpressure safety valve automatically opens to release the excess pressure until the safe pressure is restored, at which point the valve automatically closes. When the internal pressure of the air chamber falls below the lower limit, the underpressure safety valve automatically opens to prevent the upstream air duct from collapsing or deforming, until the safe pressure is restored, at which point the valve closes. Based on this, the above method may also include the following steps:

[0043] If the measured pressure exceeds the preset upper pressure limit, the overpressure safety valve is opened until the measured pressure drops to the safe pressure range; and / or, if the measured pressure is less than the preset lower pressure limit, the underpressure safety valve is opened until the measured pressure rises to the safe pressure range. For example, this safe pressure range can be determined based on the parameters of the air chamber and the main fan.

[0044] When the pressure inside the air chamber is too high, the overpressure safety valve will open. In this case, the relay fan will be controlled to run at a higher frequency signal to accelerate the operation and reduce the pressure inside the air chamber as quickly as possible. When the pressure inside the air chamber is too low, the underpressure safety valve will open. In this case, the relay fan will be controlled to run at a lower frequency signal to slow down the operation and prevent negative pressure inside the air chamber from collapsing the upstream air duct. Based on this, the above method may also include the following steps:

[0045] If the measured pressure is greater than the preset upper pressure limit, the relay fan will be controlled to operate at a preset higher frequency; and / or, if the measured pressure is less than the preset lower pressure limit, the relay fan will be controlled to operate at a preset lower frequency. This preset lower frequency is much lower than the preset higher frequency.

[0046] Considering the operational safety of the relay fan, after calculating the current frequency using the above method, it is necessary to further determine whether the current frequency is within a reasonable range (usually 0–50 Hz). Only if the current frequency is within a reasonable range will the relay fan be controlled based on that current frequency. Therefore, before controlling the relay fan based on the current frequency, the above method also includes: determining whether the current frequency is within a preset reasonable frequency range; if so, then executing the step of controlling the relay fan based on the current frequency.

[0047] In this embodiment, a microswitch can be installed at the overpressure safety valve and at the underpressure safety valve, so as to obtain the open or closed state of the overpressure safety valve and the underpressure safety valve through the microswitch. Based on this, the above method may further include the following steps:

[0048] Based on the output signal of the microswitch, determine the open / closed state of the overpressure safety valve and whether the measured pressure exceeds the preset upper pressure limit; or, based on the output signal of the microswitch, determine the open / closed state of the underpressure safety valve and whether the measured pressure is less than the preset lower pressure limit. The opening of the overpressure safety valve corresponds to a measured pressure exceeding the preset upper pressure limit; the opening of the underpressure safety valve corresponds to a measured pressure less than the preset lower pressure limit.

[0049] Optionally, the above method further includes: when the ventilation duct stops supplying air, the relay fan is controlled to shut down only after the upstream fan of the ventilation duct is shut down, so as to avoid the air pressure in the air chamber and the upstream duct being too low due to only the relay fan running.

[0050] For example, the formula for calculating the current frequency of the relay fan is as follows:

[0051]

[0052] e t =P t -P

[0053] Where P is the preset reasonable pressure, P t f is the measured pressure inside the wind tunnel at time t, and f is the initial frequency of the relay wind turbine. t k is the current frequency of the relay wind turbine at time t. p It is the proportionality coefficient, k i It is the integral coefficient, k d These are the differential coefficients.

[0054] See Figure 3The diagram shows the control principle of the relay fan. It illustrates the connection between the relay fan's frequency converter's RS485 communication interface and the PLC. The PLC's analog input module is connected to the air chamber pressure sensor. The PLC's Ethernet interface is connected to a 4G gateway module. The 4G gateway module connects to a cloud platform via a 4G network. The cloud platform communicates with application software on a smart terminal (e.g., a mobile phone), allowing the smart terminal to monitor the operating status at any time. Both the overpressure and underpressure safety valves are equipped with microswitches to detect their status and input signals to the PLC's I / O points.

[0055] The output of the air chamber pressure sensor can output a 4-20mA current signal. This current signal is connected to the PLC's analog input module. The PLC adjusts the frequency based on the difference between the actual feedback pressure and the set pressure, calculating the magnitude of the frequency increase or decrease. The PLC calculates a new frequency setpoint based on the magnitude of the frequency increase / decrease and the minimum operating frequency setpoint of the relay fan. This new setpoint is then written to the relay fan inverter via RS485 or an analog interface. The safety valve's status is controlled by the normally closed contact AB of its installed microswitch, which is connected to the PLC's I / O point. The opening and closing status of the safety valve is determined by the on / off state of the I / O point.

[0056] Specifically, the following steps can be used to control duct ventilation:

[0057] The first step is for the user to turn on the upstream blower and switch the relay blower signal source to intelligent air chamber control.

[0058] The second step is to start the relay fan once the upstream duct has fully expanded.

[0059] In intelligent air chamber control mode: The relay fan frequency converter uses the RS485 communication interface or analog signal as the frequency command source, and the PLC signal as the frequency source. The data is written to the designated PLC register. The PLC calculates the frequency set value based on the pressure signal fed back by the air chamber pressure sensor and writes it to the frequency converter, so that the internal pressure of the air chamber is in dynamic balance within an appropriate range.

[0060] When the internal pressure of the air chamber exceeds the upper limit, the overpressure safety valve automatically opens to release excess pressure until the safe pressure is restored, at which point the valve automatically closes. When the internal pressure of the air chamber falls below the lower limit, the underpressure safety valve automatically opens to prevent the upstream duct from collapsing and deforming, until the safe pressure is restored, at which point the valve closes. Furthermore, when the internal pressure of the air chamber is too high, the overpressure safety valve opens, and the PLC automatically outputs a higher frequency signal via microswitch feedback to accelerate the operation of the relay fan and reduce the internal pressure of the air chamber. When the internal pressure of the air chamber is too low, the underpressure safety valve opens, and the PLC automatically outputs a lower frequency signal via microswitch feedback to slow down the operation of the relay fan and prevent negative pressure inside the air chamber from causing the upstream duct to collapse.

[0061] The pressure control process within the compartment is as follows: The RS485 interface of the fan inverter is connected to the RS485 interface of the PLC. The PLC's analog input module is connected to the air compartment pressure sensor. During operation, the air compartment pressure sensor monitors the internal pressure signal in real time and compares it with the set reasonable pressure. Based on the pressure difference at each moment, the PLC modifies the current frequency command value. The current frequency is calculated as follows:

[0062]

[0063] e t =P t -P

[0064] Where P is the preset reasonable pressure, P t is the measured pressure inside the wind tunnel at time t, and f is the initial frequency of the relay fan (e.g., the minimum operating frequency of the relay fan). t k is the current frequency of the relay wind turbine at time t. p It is the proportionality coefficient, k i It is the integral coefficient, k d These are the differential coefficients.

[0065] After the PLC calculates the new frequency setting value for the relay fan, and verifies that the frequency is within a reasonable range (usually 0-50Hz), the new target frequency is written into the frequency setting value register of the inverter through the RS485 communication interface, thereby adjusting the output frequency of the relay fan inverter.

[0066] The relay fan frequency converter in the system can also use an analog input interface as the source of frequency commands. The analog input interface of the relay fan frequency converter is connected to the analog output interface of the PLC. The analog input module of the PLC is connected to the air chamber pressure sensor. The air chamber pressure sensor detects the internal pressure signal of the air chamber in real time during operation and compares it with the set reasonable pressure. The PLC modifies the current frequency command value according to the pressure difference at each moment.

[0067] The method provided in this embodiment of the invention can avoid the inherent problems of air volume waste (and high power loss) in existing relay ventilation schemes; avoid the recirculation of polluted air and is not affected by actual working conditions; be fully automated without technical intervention, with the air volume at the working face directly controlled by the ventilation fan at the opening, just like a single fan is running; be highly efficient and energy-saving, and the initial investment can be recovered quickly.

[0068] Figure 4 This is a schematic diagram of a relay fan control device according to an embodiment of the present invention. The device includes:

[0069] The pressure acquisition module 401 is used to acquire the measured pressure of the wind cell when the relay wind turbine is started.

[0070] The frequency determination module 402 is used to determine the current frequency of the relay fan based on the difference between the measured pressure and the preset reasonable pressure.

[0071] The operation control module 403 is used to control the operation of the relay fan according to the current frequency.

[0072] The relay fan control device provided in this invention can adjust the frequency of the relay fan at any time according to the internal pressure of the air chamber, so that the internal pressure of the air chamber is in dynamic balance within an appropriate range. No on-site adjustment or manual intervention is required. The relay fan can achieve flexible air volume transmission, thereby achieving air supply at low cost and low energy consumption, without air volume waste and avoiding the risk of recirculation of polluted air, thus improving air supply efficiency.

[0073] Optionally, the air chamber is equipped with an overpressure safety valve and / or an underpressure safety valve; the operation control module is further configured to: if the measured pressure is greater than the preset upper pressure limit, control the overpressure safety valve to open until the measured pressure drops to the safe pressure range; and / or, if the measured pressure is less than the preset lower pressure limit, control the underpressure safety valve to open until the measured pressure rises to the safe pressure range.

[0074] Optionally, the operation control module is further configured to: control the relay fan to operate at a preset higher frequency if the measured pressure is greater than the preset upper pressure limit; and / or, control the relay fan to operate at a preset lower frequency if the measured pressure is less than the preset lower pressure limit.

[0075] Optionally, the frequency determination module is specifically used for: calculating the difference between the measured pressure and the preset reasonable pressure to obtain the current difference value; calculating the frequency increase value based on the current difference value, the difference between the current difference value and the previous time value, and the sum of the current differences value at each historical time value; the current difference value is positively correlated with the frequency increase value, and the sum of the current differences value at each historical time value is positively correlated with the frequency increase value; when the current difference value is greater than the difference value at the previous time value, the difference between the current difference value and the previous time value is positively correlated with the frequency increase value, and when the current difference value is less than the difference value at the previous time value, the difference between the current difference value and the previous time value is negatively correlated with the frequency increase value; summing the frequency increase value with the initial frequency to calculate the current frequency of the relay fan; the difference value at the previous time value is the difference between the measured pressure and the preset reasonable pressure at the previous time value, and the current difference value at each historical time value is the difference between the measured pressure and the preset reasonable pressure at each historical time value.

[0076] Optionally, the formula for calculating the current frequency of the relay fan is as follows:

[0077]

[0078] e t =P t -P

[0079] Where P is the preset reasonable pressure, P t f is the measured pressure inside the wind tunnel at time t, and f is the initial frequency of the relay wind turbine. t k is the current frequency of the relay wind turbine at time t. p It is the proportionality coefficient, k i It is the integral coefficient, k d These are the differential coefficients.

[0080] Optionally, the device further includes a frequency determination module, used to: determine whether the current frequency is within a preset frequency range; if so, execute the step of controlling the relay fan to operate according to the current frequency.

[0081] Optionally, the overpressure safety valve is equipped with a micro switch, and the underpressure safety valve is equipped with a micro switch; the device also includes a safety valve status judgment module, used to: determine the open / closed state of the overpressure safety valve and whether the measured pressure is greater than the preset pressure upper limit based on the output signal of the micro switch; and determine the open / closed state of the underpressure safety valve and whether the measured pressure is less than the preset pressure lower limit based on the output signal of the micro switch.

[0082] Optionally, the operation control module is further configured to: when the ventilation duct stops supplying air, control the relay fan to shut down after the upstream fan of the ventilation duct is shut down.

[0083] This invention provides a relay fan controller, which is connected to a pressure sensor, a safety valve, a relay fan frequency converter, and a network module, respectively.

[0084] The pressure sensor and the safety valve are both installed in the air chamber connected to the relay fan. The pressure sensor is used to detect the pressure in the air chamber, and the safety valve is used to open when the pressure in the air chamber is greater than the preset upper pressure limit or less than the preset lower pressure limit.

[0085] The network module is used to send the pressure inside the wind tunnel and the current frequency of the relay fan to a designated terminal or a designated platform;

[0086] The controller is used to execute the above-described relay fan control method.

[0087] This invention also provides a computer-readable storage medium storing a computer program. When executed by a processor, this computer program implements the various processes of the above-described image segmentation-based yield measurement method embodiments and achieves the same technical effects. To avoid repetition, it will not be described again here. The computer-readable storage medium may be a read-only memory (ROM), a random access memory (RAM), a magnetic disk, or an optical disk, etc.

[0088] Of course, those skilled in the art will understand that all or part of the processes in the above embodiments can be implemented by computer-controlled devices. The program can be stored in a computer-readable storage medium. When the program is executed, it can include the processes of the above method embodiments. The storage medium can be a memory, a disk, an optical disk, etc.

[0089] In this document, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, without necessarily requiring or implying any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0090] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. The same or similar parts between the various embodiments can be referred to each other.

[0091] The above description of the disclosed embodiments will enable those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A relay fan control method characterized by, The relay fan is connected with a ventilation air duct, and the method comprises: In the case that the relay fan is started, a measured pressure of the air warehouse is acquired; According to a difference between the measured pressure and a preset reasonable pressure, a current frequency of the relay fan is determined; including: a current difference is calculated by the difference between the measured pressure and the preset reasonable pressure; a frequency increasing value is calculated according to the current difference, a difference between the current difference and a last time difference, and a sum of each historical time current difference; the current difference and the frequency increasing value are positively correlated, and the sum of each historical time current difference and the frequency increasing value are positively correlated; in the case that the current difference is greater than the last time difference, a difference between the current difference and the last time difference and the frequency increasing value are positively correlated, and in the case that the current difference is less than the last time difference, a difference between the current difference and the last time difference and the frequency increasing value are negatively correlated; the current frequency of the relay fan is calculated by summing the frequency increasing value and an initial frequency; the last time difference is a difference between a last time measured pressure and the preset reasonable pressure, and the sum of each historical time current difference is a sum of differences between each historical time measured pressure and the preset reasonable pressure; a calculation formula of the current frequency of the relay fan is as follows: Wherein, P is the preset reasonable pressure, Pt is a measured pressure inside the air warehouse at the t time, f is an initial frequency of the relay fan, ft is the current frequency of the relay fan at the t time, kp is a proportional coefficient, ki is an integral coefficient, and kd is a differential coefficient; According to the current frequency, the relay fan is controlled to run.

2. The method of claim 1, wherein, The air warehouse is provided with an overpressure safety valve and / or an underpressure safety valve; the method further comprises: If the measured pressure is greater than a preset pressure upper limit, the overpressure safety valve is controlled to open until the measured pressure is reduced to a safe pressure range; and / or, If the measured pressure is less than a preset pressure lower limit, the underpressure safety valve is controlled to open until the measured pressure is increased to the safe pressure range.

3. The method according to claim 1 or 2, characterized in that, The method further comprises: If the measured pressure is greater than the preset pressure upper limit, the relay fan is controlled to run according to a preset higher frequency; and / or, If the measured pressure is less than the preset pressure lower limit, the relay fan is controlled to run according to a preset lower frequency.

4. The method of claim 1, wherein, Before the relay fan is controlled to run according to the current frequency, the method further comprises: It is judged whether the current frequency is in a preset frequency reasonable range; If yes, the step of controlling the relay fan to run according to the current frequency is executed.

5. The method of claim 2, wherein, The overpressure safety valve is provided with a microswitch, and the underpressure safety valve is provided with a microswitch; the method further comprises: According to an output signal of the microswitch, it is determined whether the overpressure safety valve is opened or closed and whether the measured pressure is greater than a preset pressure upper limit; or, According to an output signal of the microswitch, it is determined whether the underpressure safety valve is opened or closed and whether the measured pressure is less than a preset pressure lower limit.

6. The method of claim 1, wherein, The method further comprises: When the ventilation air duct stops air supply, the relay fan is controlled to be closed after an upstream air supply fan of the ventilation air duct is closed.

7. A relay fan control device characterized by comprising: The device is used for executing the relay fan control method in any one of claims 1-6. The pressure acquisition module is used for acquiring the measured pressure of the air warehouse in the case that the relay fan is started. The frequency determination module is used for determining the current frequency of the relay fan according to the difference between the measured pressure and the preset reasonable pressure. The operation control module is used for controlling the operation of the relay fan according to the current frequency.

8. A relay fan controller characterized by, The controller is connected with a pressure sensor, a safety valve, a relay fan frequency converter and a network module respectively. The pressure sensor and the safety valve are arranged in the air warehouse connected with the relay fan, the pressure sensor is used for detecting the pressure in the air warehouse, and the safety valve is used for being opened in the case that the pressure in the air warehouse is greater than a preset upper limit of pressure or less than a preset lower limit of pressure. The network module is used for sending the pressure in the air warehouse and the current frequency of the relay fan to a specified terminal or a specified platform. The controller is used for executing the relay fan control method in any one of claims 1-6.

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