Fire-fighting water supply system and control method

Abstract

The invention discloses a fire-fighting water supply system and a control method, and belongs to the technical field of fire fighting, the fire-fighting water supply system comprises a water tank, a water inlet pipeline, a pumping unit, a water outlet pipeline and a nozzle which are communicated in sequence, and the pumping unit comprises at least two water pumps and a valve group system connected between the water pumps; the height monitoring module is used for respectively acquiring the liquid level height of the water tank and the height of the nozzle; the flow regulating valve is arranged on the water outlet pipeline, and the opening degree of the flow regulating valve is adjustable; and the controller is used for receiving a signal of the height monitoring module and controlling the on-off state of the valve group system, so that the at least two water pumps are configured to be in at least one of a parallel working mode, a series working mode or a single-pump working mode, and the opening degree of the flow regulating valve is correspondingly regulated. The problem that the maximum water supply capacity cannot be accurately predicted and adjusted to the target flow due to real-time fluctuation of pipe network resistance and height difference caused by dynamic change of a water outlet pipeline of an existing fire-fighting water supply system is solved.

Description

Technical Field

[0001] This invention relates to the field of fire protection technology, and more specifically, to a fire water supply system and control method. Background Technology

[0002] Fire water supply systems are core facilities in fire emergency rescue, and their water supply stability and flow adjustability directly affect fire extinguishing effectiveness and rescue efficiency. Currently, most existing fire water supply systems use centrifugal pumps as fire pumps. Water is drawn from the water tank through the inlet pipe, pressurized by the fire pump, and then delivered to the terminal nozzles through the outlet pipe to spray onto the fire scene for fire extinguishing operations.

[0003] In actual firefighting operations, water tanks are usually fixed (such as fire truck water tanks), while the outlet pipes are mostly flexible hoses that need to be moved and bent flexibly according to the location of the fire. The nozzle height also changes depending on the rescue scenario (such as high-altitude firefighting or ground firefighting). This dynamic change causes real-time fluctuations in the pipe network resistance coefficient and the inlet-outlet elevation difference between the pump outlet and the nozzle, which in turn changes the current flow rate and the maximum delivery capacity of the fire pump, causing great inconvenience to the flow regulation and control of the water supply system.

[0004] Currently, when adjusting water supply flow, firefighters mainly rely on experience to tentatively start and stop water pumps or adjust valves. They lack an accurate understanding of the system's maximum water supply capacity under the current pipeline conditions, and it is difficult to quickly and accurately adjust to the target flow. This extensive control method is inefficient and may lead to insufficient water supply, affecting firefighting effectiveness, or causing equipment overload and energy waste.

[0005] In view of this, the present invention provides a fire-fighting water supply system and control method to solve the above problems. Summary of the Invention

[0006] The purpose of this invention is to provide a fire-fighting water supply system and control method, which solves the problem that existing fire-fighting water supply systems cannot accurately predict the maximum water supply capacity and adjust it to the target flow rate due to real-time fluctuations in pipeline resistance and elevation difference caused by dynamic changes in the outlet pipeline.

[0007] To achieve the above objectives, the present invention provides the following technical solution: In a first aspect, the present invention provides a fire-fighting water supply system, comprising a water tank, an inlet pipe, a pumping unit, an outlet pipe and a nozzle arranged in sequence, wherein the pumping unit comprises at least two water pumps and a valve group system connected between the water pumps; The system also includes: A height monitoring module is used to obtain the liquid level in the water tank and the height of the nozzle, respectively. A flow regulating valve is installed on the outlet pipe, and its opening degree is adjustable; The controller is electrically connected to the height monitoring module, the flow regulating valve, the water pump, and the valve group system, respectively. It is used to receive signals from the height monitoring module and control the on / off state of the valve group system to configure the at least two water pumps to at least one of parallel operation mode, series operation mode, or single pump operation mode, and to adjust the opening degree of the flow regulating valve accordingly.

[0008] A further preferred embodiment is that the height monitoring module includes a first altimeter located inside the water tank and a second altimeter located at the nozzle.

[0009] A further preferred embodiment is that the valve group system includes multiple electric valves, and the working mode is switched by controlling the opening and closing combinations of different electric valves.

[0010] A further preferred embodiment is that the outlet pipe is also equipped with a flow meter electrically connected to the controller.

[0011] A further preferred embodiment is that the at least two water pumps are centrifugal pumps of the same specifications.

[0012] A further preferred embodiment is that the water outlet pipe is a movable fire hose.

[0013] Secondly, the present invention provides a fire-fighting water supply control method, applied to the aforementioned fire-fighting water supply system, comprising the following steps: S1. Preset the flow-head curve and flow-power curve of the pumping unit in single pump mode, parallel mode and series mode, as well as the opening degree-resistance coefficient curve of the flow regulating valve; S2. Real-time acquisition of the pumping unit's operating mode and cyclically perform the following operations: S2.1 Calculate the current height difference ΔZ between the water tank level and the nozzle. i ; S2.2 Obtain the current opening degree K of the flow regulating valve. i And determine its corresponding current drag coefficient ζ. i ; S2.3, Get the current traffic Q i And determine the current head H of the pumping unit based on the flow-head curve corresponding to the current operating mode of the pumping unit. i ; S2.4 Calculate the current total resistance coefficient r of the pipeline network. i = (H i -ΔZ i ) / Q i 2 ; S2.5, Display current traffic Q i And the maximum feasible flow rate Q under the current pipeline network conditions m ; S3, if the desired flow command Q is received w And expected traffic Q w Not greater than the maximum feasible flow Q m If so, then the flow regulation step will be executed.

[0014] A further preferred embodiment is that the flow rate adjustment step includes: S3.1 Calculate the conditions for each operating mode to satisfy Q. w Required head H w ; S3.2 Calculate the desired resistance coefficient ζ of the flow control valve corresponding to each operating mode. w = (H w -ΔZ i ) / Q w 2 -(r i -ζ i ); S3.3 Determine the corresponding ζ for each operating mode. w Does it satisfy ζ? w ≥ζ m , where ζ m The resistance coefficient when the flow regulating valve is fully open is used to screen out the operating modes that meet the constraints. S3.4 Calculate the operating power of each of the selected operating modes and select the operating mode with the lowest power as the optimal operating mode. S3.5. Control the pumping unit to switch to the optimal operating mode and adjust the opening of the flow regulating valve so that the resistance coefficient of the flow regulating valve reaches the ζ corresponding to this mode. w .

[0015] A further preferred embodiment is the maximum feasible flow rate Q. m The calculation method is as follows: First, calculate the minimum total resistance coefficient r of the pipeline network. m =ri-ζi+ζ m , where ζ m The minimum resistance coefficient when the flow control valve is fully open is given; then, H=r is calculated separately. m ×Q 2 +ΔZ i The intersection points of the corresponding curves with the flow-head curves corresponding to the three operating modes are used to obtain the corresponding flow values. The maximum value among these intersection points is Q. m , where Q and H are the flow rate and head, respectively.

[0016] A further preferred embodiment is: in step S3, if the received desired traffic Q w Greater than the maximum feasible flow Q m If the flow regulation is not executed, a warning message will be issued.

[0017] In summary, the present invention has the following beneficial effects: 1. Intelligent flow prediction mechanism under dynamic pipeline network parameters To address the challenge of flow control in fire-fighting water supply systems caused by dynamic changes in the pipe network, this invention utilizes dual height gauges to collect real-time elevation difference data. Combined with flow meter readings and pre-set pump station characteristic curves, a dynamic calculation model for the pipe network resistance coefficient is established. This mechanism can quickly derive the maximum feasible flow rate Q under current operating conditions. m This effectively solves the problem of inaccurate flow prediction caused by parameter changes in traditional systems, providing a precise upper limit reference for flow supply for fire fighting operations, and avoiding insufficient water supply, equipment overload, and wasted time caused by blind adjustments.

[0018] 2. Multi-mode pump station operation optimization strategy Through innovative valve combination design and preset flow-head curves for three operating modes (single pump / parallel / series), the system can adjust the flow rate Q according to the user-defined desired flow rate. w It automatically matches the optimal operating mode. For example, when a large flow rate is required, it may intelligently switch to parallel mode to increase the delivery capacity, and when a high head is required, it may activate series mode to increase the pressure. Compared with traditional fixed mode pump stations, the energy utilization rate is significantly improved, while ensuring the flexibility and efficiency of fire fighting operations.

[0019] 3. Real-time drag coefficient correction technology Based on the online calibration function of the flow control valve opening-resistance coefficient curve, and combined with the total pipeline resistance, the current pipeline resistance coefficient r is calculated in real time. i =(H i -ΔZ i ) / Q i 2 This enables online dynamic updating of pipeline resistance characteristics, better adapting to various application scenarios and significantly improving the response speed and stability of flow regulation.

[0020] 4. Maximum Flow Visual Early Warning System The current traffic flow and the theoretical maximum feasible traffic flow are displayed simultaneously on the screen, creating an intuitive human-computer interaction interface. When the operator's expected traffic flow exceeds Q... m In such cases, the system automatically triggers an over-limit warning and refuses to execute, avoiding ineffective operations. This design allows firefighters to monitor the system's supply capacity boundaries in real time, providing crucial decision-making support for adjusting firefighting tactics and effectively shortening emergency response time.

[0021] 5. Adaptive flow regulation algorithm By integrating desired head calculation and valve resistance coefficient inversion technology, a complete closed-loop control link is formed. The system can automatically calculate and satisfy Q... wThe minimum power operating mode is required, and the opening of the flow regulating valve is adjusted synchronously. The flow regulation accuracy and energy efficiency are high, achieving a dual optimization of high efficiency and economy in fire water supply.

[0022] This invention is applicable to situations involving dynamic changes in water outlet pipes, particularly those involving dynamic changes in the pipe's curvature and the height of the nozzle at the end. It can sense these dynamic changes in the water outlet pipe online in real time, accurately predict the maximum flow rate under the corresponding conditions, and automatically optimize and execute the user's flow adjustment commands. It is objective, scientific, reasonable, and reliable, eliminating the reliance on human experience in traditional solutions and eliminating the need for trial and error. It solves the problem of predicting and regulating the ultimate flow rate of the water supply system during dynamic changes in the length, position, and height of the water outlet pipe. The control method can calculate the pipe resistance, maximum water supply, and current elevation difference in real time. When water flow adjustment is required, the system automatically selects the most energy-efficient operating mode and precisely controls the valve opening to ensure stable and efficient water supply. It particularly solves the water supply control problems caused by pipe movement, curvature, or height changes during firefighting operations. Attached Figure Description

[0023] Figure 1 This is a structural block diagram of the fire-fighting water supply system in an embodiment of the present invention; Figure 2 This is a structural block diagram of a single-pump working mode of a fire-fighting water supply system in a preferred embodiment of the present invention; Figure 3 This is a structural block diagram of the parallel operation mode of the fire water supply system in an embodiment of the present invention; Figure 4 This is a structural block diagram of the series operation mode of the fire water supply system in an embodiment of the present invention; Figure 5 This is a flowchart of the fire water supply control method in an embodiment of the present invention; Figure 6 This is a schematic diagram of the flow-head curves and pipeline characteristic curves corresponding to the three working modes of the pumping unit in this embodiment of the invention. Figure 7 This is a schematic diagram of the flow-power curves corresponding to the three working modes of the pumping unit in this embodiment of the invention. Figure 8 This is a schematic diagram of the opening degree-resistance coefficient curve of the flow regulating valve in an embodiment of the present invention.

[0024] In the diagram, 1. Water tank; 2. Inlet pipe; 3. Pumping unit; 311. First valve; 312. Second valve; 313. Third valve; 32. First branch pipe; 33. Second branch pipe; 34. Third branch pipe; 35. First water pump; 36. Second water pump; 4. Outlet pipe; 5. Nozzle; 61. First altimeter; 62. Second altimeter; 7. Flow regulating valve; 8. Flow meter.

[0025] Figure 2-4 In the diagram, the direction of water flow is indicated by arrows. Detailed Implementation

[0026] The invention will now be described in further detail with reference to the accompanying drawings.

[0027] like Figure 1-4 As shown, this invention provides a fire-fighting water supply system, including a water tank 1, an inlet pipe 2, a pumping unit 3, an outlet pipe 4, a nozzle 5, a height monitoring module, a flow regulating valve 7, and a controller. The water tank 1, inlet pipe 2, pumping unit 3, outlet pipe 4, and nozzle 5 are sequentially connected. The water tank 1 is used to store fire-fighting water, serving as the water source for fire-fighting water supply. Its volume can be designed according to actual fire-fighting needs, and it possesses corrosion-resistant and impact-resistant characteristics to ensure stable water supply during fire-fighting operations. One end of the inlet pipe 2 is connected to the water tank 1, and its opening extends below the liquid surface inside the water tank 1, used to introduce water from the water tank 1 into the pumping unit 3. The diameter of the inlet pipe 2 is designed according to the rated flow rate of the pumping unit 3 to ensure smooth water flow and reduce pipe resistance. The pumping unit 3, as the core of the system's pressurization, is used to pressurize the water introduced from the inlet pipe 2 and deliver it to the outlet pipe 4. It includes at least two water pumps and a valve group system connected between the pumps. One end of the water outlet pipe 4 is connected to the outlet of the pumping unit 3, and the other end is connected to the nozzle 5, which is used to deliver the pressurized fire water to the nozzle 5. The nozzle 5 is used to spray the fire water to the fire scene to realize the fire extinguishing operation. Specifically, the nozzle 5 can be a direct current spray nozzle, which can switch between direct current and spray modes according to the fire extinguishing needs, and is suitable for different types of fires (such as solid fires and liquid fires).

[0028] The height monitoring module is used to acquire the liquid level in water tank 1 and the height of nozzle 5, providing basic data for subsequent height difference calculations. The flow regulating valve 7 is located on the outlet pipe 4, and its opening is flexibly adjustable to regulate the water flow resistance in the outlet pipe 4, thereby controlling the water supply flow. The controller, as the core of the system, is electrically connected to the height monitoring module, the flow regulating valve 7, each water pump, and the valve group system. It can receive the height signal transmitted by the height monitoring module in real time and, by controlling the on / off state of the valve group system, configure at least two water pumps into at least one of parallel operation mode, series operation mode, or single pump operation mode, and correspondingly adjust the opening of the flow regulating valve 7 to adapt to different fire-fighting water supply needs.

[0029] Specifically, the outlet pipe 4 is a movable fire hose. Fire hoses are flexible, bendable, and movable, allowing operators to adjust them flexibly according to the fire location and adapt to different rescue scenarios. It should be noted that the nozzle height 5 refers to the vertical elevation of the terminal nozzle 5 relative to a reference surface (usually sea level or geoid) during firefighting operations.

[0030] In the above technical solution, this invention, by setting up a height monitoring module, achieves for the first time real-time and automatic acquisition of two key variables: the liquid level in water tank 1 and the height of nozzle 5, providing a precise data foundation for the system to perceive changes in the external environment. Based on this data, and combined with the switching function of the valve group system, the controller upgrades the original static water supply system, which relied on manual judgment, into a dynamic intelligent system capable of responding to fluctuations in the external environment in real time, fundamentally solving the blind spot problem of traditional solutions being unable to perceive changes in the pipeline network.

[0031] like Figure 1-4 As shown, the outlet pipe 4 is also equipped with a flow meter 8 that is electrically connected to the controller. This flow meter is used to detect the water flow rate in the outlet pipe 4 in real time and transmit the flow data to the controller, providing basic data for pipe network parameter calculation and flow regulation.

[0032] In one specific embodiment, the flow meter 8 is an electromagnetic flow meter, whose measurement range is adapted to the water supply flow of the system, and the measurement error is no greater than ±0.5%, ensuring the accuracy of the flow data.

[0033] like Figure 1-4 As shown, the height monitoring module includes a first height gauge 61 installed inside the water tank 1 and a second height gauge 62 installed at the nozzle 5. The first height gauge 61 is installed inside the water tank 1 and floats on the liquid surface to detect the liquid level in the water tank 1 in real time. The second height gauge 62 is installed on the nozzle 5 to detect the height of the nozzle 5 in real time.

[0034] In one specific embodiment, both the first altimeter 61 and the second altimeter 62 are piezoresistive or piezoelectric high-precision barometric pressure sensors. Their working principle is to detect changes in atmospheric pressure and calculate altitude by utilizing the law that air pressure decreases with increasing altitude (approximately 12 hPa per 100 meters). Currently, high-precision models can achieve decimeter-level resolution, ensuring the accuracy of altitude data and thus guaranteeing the accuracy of elevation difference calculations. Both the first altimeter 61 and the second altimeter 62 are electrically connected to the controller.

[0035] In another embodiment, the first altimeter 61 and the second altimeter 62 use GPS, BeiDou or other satellite navigation tools for positioning to achieve altitude measurement.

[0036] Furthermore, the flow regulating valve 7 is an electric valve with adjustable opening, which can communicate bidirectionally with the controller, report its own opening to the controller in real time, and receive the controller's opening adjustment command.

[0037] Furthermore, the controller can be a PLC controller or an industrial microcontroller to receive the height signal from the height monitoring module, the flow signal from the flow meter 8, the opening signal from the flow regulating valve 7, and the status signal from the valve group system. It calculates the pipeline parameters through a preset algorithm, controls the on / off state of the valve group system (switching working modes), the start and stop of the water pump, and the opening of the flow regulating valve 7, thereby realizing intelligent control of the system.

[0038] Optionally, the system also includes a display screen that can display information and receive user information input. The display screen is connected to the controller and is used to display the system's operating parameters (such as current flow rate, current elevation difference, pipeline resistance coefficient, working mode, flow regulating valve opening, maximum feasible flow rate, etc.). At the same time, it can receive the desired flow rate command input by the operator to realize human-machine interaction, so that the operator can keep abreast of the system's operating status and perform flow regulation operations in real time.

[0039] In one specific embodiment, the controller and display screen are integrated into a tablet computer.

[0040] like Figure 1-4 As shown, at least two pumps are preferably centrifugal pumps of the same specifications and with a constant operating speed. Centrifugal pumps have the characteristics of stable flow rate, adjustable head, and high efficiency. Pumps of the same specifications can simplify the control logic for switching operating modes and facilitate the preset of unified flow-head and flow-power curves. The valve group system includes multiple electric valves. Electric valves have the characteristics of fast opening and closing speed, precise control, and communication with the controller. By controlling the opening and closing combinations of different electric valves, the switching of operating modes can be achieved.

[0041] Specifically, the pumping unit 3 includes a valve assembly system, a first branch pipe 32, a second branch pipe 33, a third branch pipe 34, and two identical water pumps, a first water pump 35 and a second water pump 36. The pumping unit 3 has an inlet port and an outlet port. The inlet port is connected to the inlet pipe 2, and the outlet port is connected to the outlet pipe 4. The first branch pipe 32 and the second branch pipe 33 are connected in parallel between the inlet and outlet ports of the pumping unit 3. The valve assembly system includes three electric valves: a first valve 311, a second valve 312, and a third valve 313. The first water pump 35 and the first valve 311 are sequentially installed on the first branch pipe 32 along the water flow direction, and the second water pump 36 and the second valve 312 are sequentially installed on the second branch pipe 33 along the water flow direction. One end of the third branch pipe 34 is connected to the pipeline between the outlet of the first water pump 35 and the first valve 311, and the other end is connected to the pipeline between the inlet of the second water pump 36 and the water inlet port of the pumping unit 3. The third valve 313 is installed on the third branch pipe 34.

[0042] The controller is electrically connected to the first altimeter 61, the second altimeter 62, the first water pump 35, the second water pump 36, the first valve 311, the second valve 312, and the third valve 313. By controlling the opening and closing of the first valve 311, the second valve 312, and the third valve 313, as well as the start and stop of the first water pump 35 and the second water pump 36, three operating modes can be easily achieved: Single-pump mode: For example, the first water pump 35 and the first valve 311 are turned on, while the second water pump 36, the second valve 312, and the third valve 313 are turned off. In this case, only the first water pump 35 is working.

[0043] Parallel mode: Simultaneously start the first water pump 35, the second water pump 36, the first valve 311 and the second valve 312, and close the third valve 313. The two water pumps jointly draw water from the inlet port of the pumping unit 3 and supply water in parallel to the outlet port of the pumping unit 3.

[0044] Series mode: Simultaneously open the first water pump 35, the second water pump 36, the second valve 312, and the third valve 313, and close the first valve 311. Water flows through the inlet pipe 2 into the inlet port of the pumping unit 3, then flows into the first branch pipe 32. The water is pressurized for the first time by the first water pump 35, and then enters the front end of the second branch pipe 33 through the opened third electric valve. The water is pressurized for the second time by the second water pump 36, and finally flows into the outlet port of the pumping unit 3 through the opened second electric valve, and is delivered to the outlet pipe 4.

[0045] Specifically, pumping unit 3 operates in single-pump mode by default.

[0046] A fire-fighting water supply control method, applied to a fire-fighting water supply system, such as... Figure 1-8 As shown, the method includes the following steps: S1. Preset curve data: Flow-head curve and flow-power curve of pumping unit 3 in single pump mode, parallel mode and series mode, and opening degree-resistance coefficient curve of flow regulating valve 7; Specifically, the flow-head curve, flow-power curve and opening degree-resistance coefficient curve of flow regulating valve 7 corresponding to single pump mode, parallel mode and series mode are pre-stored in the controller. S2. The controller acquires the operating mode of pumping unit 3 in real time and performs the following operations in a loop: S2.1. Detect the liquid level in water tank 1 using the first height gauge 61 and the height of nozzle 5 using the second height gauge 62, and calculate the current height difference ΔZ between the two. i ; S2.2 Read the current opening degree of the flow control valve 7, and determine the current resistance coefficient ζ of the flow control valve 7 by combining it with the preset opening degree-resistance coefficient curve. i ; S2.3, Obtain the current flow rate Q of flow meter 8. i And determine the current head H of pumping unit 3 based on the flow-head curve corresponding to the current operating mode of pumping unit 3. i ; S2.4, According to formula r i =(H i -ΔZ i ) / Q i 2 Calculate the current total resistance coefficient r of the pipeline network. i , where r i H represents the current total resistance coefficient of the pipeline network. i ΔZ represents the current head of the pumping station. i Given the current elevation difference, Q i Current traffic; S2.5 Display the current flow rate Q on the screen. i And the maximum feasible flow rate Q under the current pipeline network conditions m ; S3. If the controller receives the user's desired flow rate command Q via the display screen... w And expected traffic Q w Not greater than the maximum feasible flow Q m If so, then the flow regulation step will be executed.

[0047] S3.1, the desired flow Q w Substitute the flow-head curves for each operating mode and calculate the desired flow rate Q for each operating mode. w Required expected head H w ; S3.2 Calculate the flow rate Q under each operating mode. w The desired resistance coefficient of the flow control valve 7 is ζw = (H w -ΔZ i ) / Q w 2 - (r i -ζ i ), where ζw is the resistance coefficient of the flow regulating valve 7, H w To achieve the desired lift, Q w For the desired traffic, r i ζ represents the current total resistance coefficient of the pipeline network. i The current resistance coefficient of flow control valve 7; S3.3 Filter the optimal operating mode and determine the corresponding ζ for each operating mode. w Does it satisfy ζ? w ≥ζ m , where ζ m The resistance coefficient of the flow regulating valve 7 when it is fully open is used to screen out the operating modes that meet the constraints. S3.4, The desired flow Q w Substitute the flow-power curves corresponding to the operating modes that meet the above conditions into the calculation of the operating power of each mode, and select the operating mode with the minimum power as the optimal operating mode. S3.5 The controller switches the pumping unit 3 to the optimal operating mode and adjusts the opening of the flow regulating valve 7 so that the resistance coefficient of the flow regulating valve 7 reaches the ζ corresponding to this mode. w This ensures a stable supply of the desired flow.

[0048] Specifically, the maximum feasible flow Q m The calculation method is as follows: Calculate the minimum resistance coefficient r of the pipeline network m The formula is r m =r i -ζ i +ζ m , where r m r is the minimum resistance coefficient of the pipeline network. i ζ represents the current total resistance coefficient of the pipeline network. i ζ represents the current resistance coefficient of flow control valve 7. m The resistance coefficient of the flow regulating valve 7 in the fully open state; Establish the characteristic curve equation of the pipeline network: H=r m Q²+ΔZ i Where Q is the flow rate and H is the head; The intersection points of the pipeline characteristic curve and the flow-head curves corresponding to the three operating modes are calculated separately to obtain the flow rate value corresponding to each intersection point. The maximum value is the maximum feasible flow rate Q. m .

[0049] Further, in step S3, if the controller receives the desired flow Q w Greater than the current system's maximum feasible flow Q m If the flow rate exceeds the limit, the controller will refuse to execute the flow rate adjustment step and will issue a prompt message on the display screen to indicate the error and remind the operator to adjust the expected flow rate to avoid equipment overload and adjustment failure due to excessive flow rate, thus ensuring the safe and reliable operation of the system.

[0050] Furthermore, the flow-head curve and flow-power curve of the pumping unit 3 under each operating mode, as well as the opening degree-resistance coefficient curve of the flow regulating valve, can be pre-stored in the controller in the form of tables or fitting functions.

[0051] In one specific embodiment, the flow-head curve, flow-power curve, and opening-resistance coefficient curve are all obtained by fitting the manufacturer's test data using the least squares method. The fitting function forms are quadratic functions (flow-head, flow-power) and exponential functions (opening-resistance coefficient), respectively.

[0052] This invention applies theoretical knowledge and principles of fluid mechanics and centrifugal pumps. The controller has preset flow-head curves and flow-power curves corresponding to single pump mode, parallel mode and series mode, and preset the opening degree-resistance coefficient curve of flow regulating valve 7.

[0053] The operating point of the water supply system is the intersection of the flow-head curve of pumping unit 3 and the network characteristic curve. The characteristic of the flow-head curve of pumping unit 3 is that the head continuously decreases as the flow rate increases; the characteristic of the network characteristic curve is that the total head consumed by the network continuously increases as the flow rate increases. The network characteristic curve can be described as ΔP = rQ. 2 +ΔZ, where ΔP is the total head consumed by the pipeline network at flow rate Q, r is the pipeline network resistance coefficient, and ΔZ is the height difference between the pipeline network inlet and outlet.

[0054] The resistance of the entire water supply system network comes from the flow regulating valve 7 and the pipes. The resistance coefficient of the flow regulating valve 7 is related to its opening degree, and there exists a minimum resistance coefficient corresponding to its maximum opening degree. The entire pipeline includes the inlet pipe 2, the pumping unit 3 pipe, and the outlet pipe 4. The lengths of the first two are very short and can be optimized to reduce resistance as much as possible. Therefore, the overall pipeline resistance coefficient mainly originates from the outlet pipe, and its variation is mainly related to the length, curvature, and location of the outlet pipe. In addition, the head provided by the pumping unit 3, besides overcoming the resistance of the entire network at the corresponding flow rate, also provides an increment in position head, which is equal to the vertical height difference between the liquid level in the water tank 1 and the nozzle 5. That is, the head H of the pumping unit 3 is equal to the total head ΔP consumed by the network.

[0055] Therefore, the current head H of pumping unit 3 i =r i Q i 2 +ΔZ i Q i For the current flow rate, ΔZ i r is the vertical height difference between the current liquid level and nozzle 5. i This represents the current total resistance coefficient of the pipeline network. Current head H i Based on the current traffic Q i The flow rate-head curve corresponding to the current operating mode is obtained; therefore, as long as the current flow rate Q is measured... i The vertical height difference ΔZ between the current liquid level and nozzle 5 iThis allows us to deduce the current total resistance coefficient r of the pipeline network. i .

[0056] Current total resistance coefficient r of the pipeline network i The current resistance coefficient ζ of flow control valve 7 i The sum of the current resistance coefficients of the pipeline and the flow control valve 7, where the current resistance coefficient ζ can be determined by the current opening degree of the flow control valve 7. i Therefore, it can be further deduced that the current resistance coefficient of the pipeline is r. i -ζ i .

[0057] The pipeline resistance coefficient is limited by objective firefighting operations and cannot be adjusted; however, the resistance coefficient of the flow regulating valve 7 is adjustable, with its minimum value being the resistance coefficient ζ corresponding to the valve being fully open. m In the current operating mode, when the flow regulating valve 7 is fully open, the minimum resistance coefficient r of the pipeline network is... m =r i -ζ i +ζ m .

[0058] To obtain the maximum flow rate Q while keeping the pipe resistance coefficient constant... m Then the flow regulating valve 7 should be fully open, that is, the pipeline characteristic curve is H=r m Q 2 +ΔZ i , where Q and H are the flow rate and head, respectively.

[0059] As for the maximum flow Q m The value depends on the aforementioned pipeline characteristic curve H=r. m Q 2 +ΔZ i The value is determined by the intersection of the flow-head curves corresponding to the three operating modes. H=r is calculated for each mode. m Q 2 +ΔZ i The intersection points of the corresponding curves with the flow-head curves corresponding to the three operating modes are used to obtain the corresponding flow values. The maximum value among these intersection points is Q. m .

[0060] Users learn about the current traffic Q i In such cases, the decision to increase or decrease the flow rate can be made based on the fire extinguishing effect; the desired flow rate Q can be input into the display screen. w The display shows the current flow rate Q. i At the same time, display the maximum flow rate Q. m This is so that users know the current maximum water supply capacity. If the input expected flow rate Q... w Greater than the maximum feasible flow Q mIf the error occurs, the flow regulation will be refused and an error message indicating that the limit has been exceeded will be displayed so that the user can correct it immediately.

[0061] Received expected traffic Q w Subsequently, in order to adjust to this flow rate, it is necessary to determine the operating mode of pumping unit 3 and the opening degree of its corresponding flow regulating valve 7 in order to implement the adjustment. This is an optimization problem, the constraint of which is that the resistance coefficient of the outlet after adjustment is greater than or equal to its minimum value, and the optimization objective is to minimize the operating energy consumption of pumping unit 3.

[0062] Specifically, firstly, the three operating modes are calculated to satisfy the expected flow rate Q. w The required head H w This can be achieved by adjusting the expected flow Q. w The three operating points (Q) of the system were obtained by substituting the flow-head curves of pumping unit 3 under the three modes respectively. w H w ).

[0063] Next, determine whether the current pipeline network can adapt to the above three operating points. Let's assume that the current pipeline network can achieve adaptation by adjusting the flow regulating valve 7 to a certain opening degree. Let the resistance coefficient corresponding to this opening degree be the expected resistance coefficient ζw of the flow regulating valve 7. Then, from the pipeline network characteristic curve, we can know that H... w =(r i -ζ i +ζ w )Q w 2 +ΔZ i That is, the desired resistance coefficient ζw of the flow control valve 7 is ζw = (H w -ΔZ i ) / Q w 2 -(r i -ζ i ).

[0064] Next, it is determined whether the constraint condition is met, that is, the expected resistance coefficient ζw of the flow control valve 7 in the three operating modes should be greater than or equal to the resistance coefficient ζ of the flow control valve 7 in the fully open state. m .

[0065] Finally, for the operating mode that satisfies the above constraints, the expected flow Q is... w Substitute the flow-power curves corresponding to these modes into the flow-power curves to find the operating mode with the lowest power. Control the pumping unit 3 to switch to this mode and adjust the opening of the flow regulating valve 7 so that the resistance coefficient of the valve after adjustment is equal to the expected resistance coefficient ζw of the flow regulating valve 7 corresponding to this mode.

[0066] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0067] Example 1: Please refer to Figure 1-4 This embodiment describes the fire water supply system and its three operating modes in detail.

[0068] The complete structural configuration of the fire water supply system in this embodiment is shown in [link to example]. Figure 1 The system is deployed on fire trucks, and the water outlet pipe 4 is a flexible hose that can be manually carried and moved and / or climbed to spray water to extinguish fires.

[0069] The system's default operating mode is single-pump mode, meaning it runs in single-pump mode by default after startup. The water flow direction in this mode is shown below. Figure 2 .

[0070] The system can also be configured by the controller to operate in parallel and series modes, with the water flow direction in each mode described below. Figure 3 and Figure 4 .

[0071] The working process controller communicates bidirectionally with each valve, obtains the valve status in real time, and can issue adjustment commands to the valve: the flow regulating valve 7 can work at any opening degree between fully closed and fully open, while in a stable state, the first valve 311, the second valve 312, and the third valve 313 only have two states: open and closed.

[0072] In this embodiment, the first water pump 35 and the second water pump 36 are centrifugal pumps of the same specifications and model, with a constant operating speed of 2980 r / min, and driven by a motor.

[0073] Please refer to Figure 6 and Figure 7 Please understand the flow-head curves and flow-power curves of pumping unit 3 in single-pump, parallel, and series modes in this embodiment. Please refer to... Figure 8 Understand the opening degree-resistance coefficient curve of the flow regulating valve 7 in this embodiment.

[0074] Based on the manufacturer's test data, a quadratic function was fitted using the least squares method to obtain the flow-head curve function expression for pumping unit 3 under each mode: Single pump mode, H = -2575.8Q 2 -173.03Q +71.733; Parallel mode, H = -643.94Q 2 -86.515Q +71.733; Series pump mode, H=-5151.5Q 2 -346.06Q + 143.47; Q represents flow rate, in meters (m).3 / s; H is the head, unit: m.

[0075] Based on the manufacturer's test data, a quadratic function was fitted using the least squares method to obtain the flow-power curve function expression for pumping unit 3 under each mode: Single pump mode, N=-6917.9Q 2 +1054.4Q+4.9225; Parallel mode, N = -3458.9Q 2 +1054.4Q+9.845; Series pump mode, N=-13836Q 2 +2108.9Q+9.845; Q represents flow rate, in meters (m). 3 / s; N is power, unit: kW.

[0076] Based on the manufacturer's test data, the least squares method was used to fit an exponential function, and the opening-resistance coefficient curve function expression of the flow control valve 7 was obtained as follows: ζ=431.02e-0.078K.

[0077] K represents the valve opening degree, in units of %; ζ represents the resistance coefficient. K=100% represents the valve fully open, K=0% represents the valve fully closed, and it is specifically stipulated that the resistance coefficient is infinite when the valve is fully closed. The resistance coefficient of the flow control valve 7 in the fully open state is: ζ m =431.02e-0.078×100=0.18.

[0078] It should be noted that, for example Figure 6 As shown, to intuitively reflect the matching relationship between pumping unit 3 and the pipeline system in the same coordinate system, this figure adopts a dual Y-axis design. The left ordinate corresponds to the head of pumping unit 3 in single-pump, parallel, and series modes, with the physical unit being meters (m); the right ordinate corresponds to the total pressure difference consumed by the pipeline system. To maintain dimensional consistency with the head of pumping unit 3, and based on the conversion relationship between pressure and liquid column height in fluid mechanics, ΔP=ρgH, the right ordinate uses the commonly used engineering unit "m water column (mH2O)" as the equivalent unit for pressure difference. 1 m water column is approximately equal to 9800 Pa (often approximated as 10000 Pa in calculations).

[0079] When the fire-fighting water supply system is in stable operation, following the law of conservation of energy, the total head H provided by pumping unit 3 to the fluid must be equal to the total pressure difference ΔP consumed by the fluid flowing through the pipe network. When the above-mentioned dual Y-axis is used and the right-hand ordinate is in meters of water column, the ordinates of the two curves can be directly established as an equation. Therefore, the intersection of the flow-head curve of pumping unit 3 and the pipe network characteristic curve is the actual operating point of the system under the current operating conditions, and the abscissa of this intersection point is the current operating flow rate of the system. If the right-hand ordinate uses the international unit of pressure Pascal (Pa), the intersection point of the two curves will lose its physical meaning as an "operating point" due to the inconsistency of physical dimensions between the left and right ordinates, and the technical purpose of this invention—to intuitively demonstrate the flow rate calculation process—cannot be achieved. In addition, to further clarify the meaning, Figure 6 Each curve is marked with a horizontal arrow to indicate whether it corresponds to the left or right vertical axis.

[0080] Example 2: The fire-fighting water supply system in this embodiment is the same as in Embodiment 1. Please refer to... Figure 5 Understand the control method of the fire water supply system in this embodiment.

[0081] At a certain moment, pumping unit 3 is operating in single-pump mode. The readings of the first altimeter 61 and the second altimeter 62 are 102m and 132m above sea level, respectively. The current opening degree K of the flow regulating valve 7 is read. i =20%, read the current flow rate Q from flow meter 8. i =0.063m 3 / s.

[0082] The current elevation difference ΔZ is calculated by the first altimeter 61 and the second altimeter 62. i =132-102=30m.

[0083] The current resistance coefficient ζ of flow control valve 7 can be determined from the function expression of its opening degree-resistance coefficient curve. i =431.02e-0.078×20=90.6.

[0084] The current traffic Q i =0.063m 3 Substituting / s into the flow-head curve corresponding to the single-pump mode of pumping unit 3, determine the current head H of pumping unit 3. i =-2575.8Q i 2 -173.03Q i +71.733=50.6m.

[0085] Calculate the current resistance coefficient r of the pipeline network i =(H i -ΔZ i) / Q i 2 =(50.6-30) / 0.0632=5190.

[0086] In other words, the characteristic curve of the current pipeline network can be expressed as ΔP=H=r i Q 2 +ΔZ i =5190Q 2 +30, such as Figure 6 As shown.

[0087] Calculate the minimum resistance coefficient r of the pipeline network m =r i -ζ i +ζ m =5190-90.6+0.18=5099.58.

[0088] Therefore, H=r m Q 2 +ΔZ i =5099.58Q 2 +30, combine this equation with the flow-head curve equations corresponding to single-pump mode, parallel mode, and series mode respectively, and obtain the corresponding flow values ​​of 0.06333m³ / h. 3 / s, 0.078m 3 / s, 0.0897m 3 / s, its maximum value is Q m =0.0897m 3 / s.

[0089] Taking the single-pump mode as an example, H=r m Q 2 +ΔZi=5099.58Q 2 +30 and H = -2575.8Q 2 Solving the equations -173.03Q + 71.733 simultaneously yields 7675.38Q. 2 +173.03Q-41.733=0. Solving this quadratic equation and discarding the negative solutions that have no physical meaning, we get Q=0.063.

[0090] The display shows the current traffic Q. i =0.063m 3 / s, maximum feasible flow Q m =0.0897m 3 / s.

[0091] User inputs desired traffic Q w =0.077m 3 / s m This instruction is executable.

[0092] ​The expected flow Q w Substituting 0.077 m³ / s into the flow-head curve expressions for single-pump mode, parallel mode, and series mode respectively, the corresponding expected head H is obtained. w The m, 61.25 m, and 86.28 m are respectively, and the expected drag coefficients ζw are -2883, 171.3, and 4393 respectively.

[0093] Taking the single-pump mode as an example, Q=0.077m 3 Substituting / s into H=-2575.8Q 2 -173.03Q + 71.733, calculate the corresponding desired head H. w =-2575.8×0.0772-173.03×0.077+71.733=43.14, the expected resistance coefficient ζ of flow regulating valve 7. w =(H w -ΔZi) / Q w 2 -(r i -ζ i =(43.14-30) / 0.0772-(5190-90.6)=-2883.

[0094] ζ m =0.18, satisfying ζ w ≥ζ m It can only operate in parallel mode and series mode.

[0095] The expected flow Q w =0.077m 3 Substituting the values ​​of / s into the flow-power curve expressions corresponding to parallel and series modes, we obtain the corresponding power values ​​of 70.5kW and 90.2kW, respectively. Clearly, the operating mode with the lowest power is the parallel mode.

[0096] Taking the parallel mode as an example, Q=0.077m 3 Substituting N=-3458.9Q into the equation / s 2 Given +1054.4Q + 9.845, calculate the corresponding power N. w =-3458.9×0.0772+1054.4×0.077+9.845=70.5.

[0097] The expected drag coefficient ζ corresponding to the parallel mode w Substituting ζ=431.02e-0.078K into the function expression of the opening-resistance coefficient curve of the flow regulating valve 7, we get 171.3=431.02e-0.078K, and thus the valve opening K=11.8.

[0098] Therefore, in order to adjust the flow rate to the desired flow rate Q w =0.077m 3 / s, the command executed is to make pumping unit 3 work in parallel working mode and adjust the opening of flow regulating valve 7 to 11.8%.

[0099] The above description is merely a preferred embodiment of the present invention. The scope of protection of the present invention is not limited to the above embodiments. All technical solutions falling within the scope of the present invention's concept are within the scope of protection of the present invention. It should be noted that for those skilled in the art, any improvements and modifications made without departing from the principle of the present invention should also be considered within the scope of protection of the present invention.

Claims

1. A fire-fighting water supply system, comprising a water tank, an inlet pipe, a pumping unit, an outlet pipe, and a nozzle arranged sequentially, characterized in that: The pumping unit includes at least two water pumps and a valve group system connected between the water pumps; The system also includes: A height monitoring module is used to obtain the liquid level in the water tank and the height of the nozzle, respectively. A flow regulating valve is installed on the outlet pipe, and its opening degree is adjustable; The controller is electrically connected to the height monitoring module, the flow regulating valve, the water pump, and the valve group system, respectively. It is used to receive signals from the height monitoring module and control the on / off state of the valve group system to configure the at least two water pumps to at least one of parallel operation mode, series operation mode, or single pump operation mode, and to adjust the opening degree of the flow regulating valve accordingly.

2. The fire-fighting water supply system according to claim 1, characterized in that: The height monitoring module includes a first altimeter located inside the water tank and a second altimeter located at the nozzle.

3. A fire-fighting water supply system according to claim 1, characterized in that: The valve group system includes multiple electric valves, and the working mode is switched by controlling the opening and closing combinations of different electric valves.

4. A fire-fighting water supply system according to claim 1, characterized in that: The outlet pipe is also equipped with a flow meter that is electrically connected to the controller.

5. A fire-fighting water supply system according to claim 1, characterized in that: The at least two water pumps are centrifugal pumps of the same specifications.

6. A fire-fighting water supply system according to claim 1, characterized in that: The water outlet pipe is a movable fire hose.

7. A fire-fighting water supply control method, applied to the fire-fighting water supply system according to any one of claims 1-6, characterized in that: Includes the following steps: S1. Preset the flow-head curve and flow-power curve of the pumping unit in single pump mode, parallel mode and series mode, as well as the opening degree-resistance coefficient curve of the flow regulating valve; S2. Real-time acquisition of the pumping unit's operating mode and cyclically perform the following operations: S2.1 Calculate the current height difference ΔZ between the water tank level and the nozzle. i ; S2.2 Obtain the current opening degree K of the flow regulating valve. i And determine its corresponding current drag coefficient ζ. i ; S2.3, Get the current traffic Q i And determine the current head H of the pumping unit based on the flow-head curve corresponding to the current operating mode of the pumping unit. i ; S2.4 Calculate the current total resistance coefficient r of the pipeline network. i = (H i -ΔZ i ) / Q i 2 ; S2.5, Display current traffic Q i And the maximum feasible flow rate Q under the current pipeline network conditions m ; S3, if the desired flow command Q is received w And expected traffic Q w Not greater than the maximum feasible flow Q m If so, then the flow regulation step will be executed.

8. A fire-fighting water supply control method according to claim 7, characterized in that: The flow regulation step includes: S3.1 Calculate the conditions for each operating mode to satisfy Q. w Required head H w ; S3.2 Calculate the desired resistance coefficient ζ of the flow control valve corresponding to each operating mode. w = (H w -ΔZ i ) / Q w 2 - (r i -ζ i ); S3.3 Determine the corresponding ζ for each operating mode. w Does it satisfy ζ? w ≥ζ m , where ζ m The resistance coefficient when the flow regulating valve is fully open is used to screen out the operating modes that meet the constraints. S3.4 Calculate the operating power of each of the selected operating modes and select the operating mode with the lowest power as the optimal operating mode. S3.

5. Control the pumping unit to switch to the optimal operating mode and adjust the opening of the flow regulating valve so that the resistance coefficient of the flow regulating valve reaches the ζ corresponding to this mode. w .

9. A fire-fighting water supply control method according to claim 7, characterized in that: The maximum feasible flow Q m The calculation method is as follows: First, calculate the minimum total resistance coefficient r of the pipeline network. m =ri-ζi+ζ m , where ζ m The minimum resistance coefficient when the flow control valve is fully open is given; then, H=r is calculated separately. m ×Q 2 +ΔZ i The intersection points of the corresponding curves with the flow-head curves corresponding to the three operating modes are used to obtain the corresponding flow values. The maximum value among these intersection points is Q. m , where Q and H are the flow rate and head, respectively.

10. A fire-fighting water supply control method according to claim 9, characterized in that: In step S3, if the received expected traffic Q w Greater than the maximum feasible flow Q m If the flow regulation is not executed, a warning message will be issued.

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