A compressed air foam fire fighting system and fire fighting vehicle

Abstract

This utility model discloses a compressed air foam fire fighting system and fire truck, comprising: two sets of foam tank assemblies for storing and transporting two different foam liquids; an air compressor assembly for providing compressed air; a fire monitor assembly for spraying compressed air foam; and a controller electrically connected to a foam pump, a pressure sensor, a flow sensor, an air compressor, an air pressure sensor, an air flow sensor, and a compressed air electric ball valve. The controller adjusts the foam pump speed, the air compressor output power, and the opening of the compressed air electric ball valve based on the pressure and flow values ​​detected by each sensor to output compressed air foam with any preset gas-liquid mixing ratio. The compressed air foam is sprayed by the fire monitor onto the surface of an object, forming a firebreak. This utility model has a wide range of gas-liquid mixing ratios, adapts to various fire fighting scenarios, and meets the strict sequential mixing requirements of the two foam liquids with air.

Description

Technical Field

[0001] This utility model relates to a compressed air foam fire-fighting system and a fire truck, belonging to the field of fire-fighting equipment. Background Technology

[0002] The existing compressed air foam fire extinguishing system has a single and fixed technical approach. Its core mixing logic is as follows: first, water and foam concentrate are initially mixed in a preset ratio through a venturi tube; then, this initial mixture is transported to a gas-liquid mixing device for secondary mixing with compressed air to form fire extinguishing foam for operation. However, this technical approach has significant drawbacks in practical applications, as detailed below.

[0003] (1) The mixing ratio range is narrow and cannot cover multiple types of foam concentrate. Existing systems rely on Venturi tubes to mix water and foam concentrate. However, the mixing ratio of Venturi tubes is limited by fixed parameters such as pipe diameter and flow rate, and can only be adjusted within a small range. In actual scenarios, the ratios of different foam concentrates vary greatly. For example, Class A foam concentrate (suitable for solid fires) commonly uses 3‰-5‰, while Class B foam concentrate (suitable for liquid fires) commonly uses 3%-6%, a difference of more than 10 times. Venturi tubes cannot exceed the adjustment limit, resulting in the system only being able to adapt to a single type of foam concentrate and failing to meet switching requirements.

[0004] (2) Poor applicability and insufficient versatility. The existing foam proportioning system of fire trucks relies on signal feedback that the foam liquid flow rate reaches a set threshold, and the threshold only matches a specific foam liquid. If a different proportion of foam liquid is used (such as changing from Class A to Class B), the flow rate of the new foam liquid will inevitably be lower than the original threshold, and the system will automatically shut down if there is no feedback, which cannot adapt to the switching of foam liquid in multiple scenarios.

[0005] Currently, there are patented methods, systems, and fire trucks equipped with the system for controlling the mixing ratio of fire-fighting foam (CN102053631B), which have improved the application range of the foam liquid to water mixing ratio to some extent. However, some problems still exist: the upper limit of the mixing ratio is limited, making it difficult to adapt to fire-fighting systems with a common gas-liquid mixing ratio of 1:14, resulting in a ratio coverage blind spot; scenarios where the two foam liquids must be mixed with compressed air in a strict order are not considered, making it unsuitable for such special fire-fighting needs; and the lack of a self-cleaning function design for fire-fighting pipelines makes it impossible to avoid the risk of residual foam liquid solidifying and corroding pipelines after operation, affecting the long-term stability of the system. Summary of the Invention

[0006] To address the problems existing in the prior art, this utility model provides a compressed air foam fire-fighting system and a fire truck.

[0007] To achieve the above objectives, this utility model employs a compressed air foam fire suppression system, comprising:

[0008] Two sets of foam tank assemblies are used to store and transport two different foam liquids respectively. Each set of foam tank assemblies includes a foam tank, foam pipeline, and a foam pump, pressure sensor, flow sensor, foam valve, and gas-liquid mixing device connected in series on the foam pipeline. The gas-liquid mixing devices of the two sets of foam tank assemblies are connected by connecting pipelines.

[0009] An air compressor assembly for providing compressed air includes an air compressor and an air compressor pipeline. An air pressure sensor, an air flow sensor, and a compressed air electric ball valve are connected in series on the air compressor pipeline. The output end of the air compressor pipeline is connected to one of the gas-liquid mixing devices, so that the compressed air is first mixed with the foam liquid in the gas-liquid mixing device. The gas-liquid mixture enters another gas-liquid mixing device through a connecting pipeline and is mixed a second time with another component of foam liquid.

[0010] A fire monitor assembly for spraying compressed air foam includes a fire monitor and a fire pipeline; a fire monitor butterfly valve is connected in series on the fire pipeline, and the input end of the fire pipeline is connected to a gas-liquid mixing device for receiving gas-liquid mixtures.

[0011] The controller is electrically connected to the foam pump, pressure sensor, and flow sensor in the foam tank assembly, and to the air compressor, air pressure sensor, air flow sensor, and compressed air electric ball valve in the air compressor assembly. The controller adjusts the speed of the foam pump, the output power of the air compressor, and the opening of the compressed air electric ball valve according to the pressure and flow values ​​detected by each sensor, so as to output compressed air foam with any preset gas-liquid mixing ratio. The compressed air foam is sprayed onto the surface of the object through the fire pipe and the fire monitor to form a fireproof isolation zone.

[0012] As an improvement, a check valve is installed in series on the foam pipeline of each foam tank assembly, located between the foam valve and the gas-liquid mixing device, to prevent the foam liquid in the foam pipeline from flowing backward.

[0013] As an improvement, an air check valve is installed in series on the air compressor assembly's air compressor line and is located between the air flow sensor and the compressed air electric ball valve to prevent compressed air in the air compressor line from flowing back into the air compressor.

[0014] As an improvement, a self-cleaning component for cleaning the foam tubing is also included, the self-cleaning component comprising a flushing tank and two flushing lines arranged in parallel.

[0015] As an improvement, a foam suction valve is installed in series between the foam tank and the foam pump on the foam pipeline of each foam tank assembly to cut off the passage between the foam tank and the foam pump during self-cleaning operations.

[0016] As an improvement, one end of each of the two flushing pipelines is connected to the outlet of the flushing water tank, and the other end is connected to the foam pipeline of each of the two foam tank assemblies, with the connection node located between the foam suction valve and the foam pump of each foam tank assembly.

[0017] As an improvement, a flushing valve is installed in series on each flushing pipeline. The flushing valve is used to control the opening and closing of the corresponding flushing pipeline and, together with the tank suction foam valve, realizes the pipeline switching between fire-fighting operation and self-cleaning operation.

[0018] In a second aspect, this utility model also provides a fire truck equipped with the aforementioned compressed air foam fire-fighting system.

[0019] Compared with the prior art, the beneficial effects of this utility model are:

[0020] (1) Wide coverage of gas-liquid mixing ratios, adaptable to various fire extinguishing scenarios. Based on data detected by flow and pressure sensors, the controller dynamically adjusts the foam pump speed, air compressor output power, and compressed air electric ball valve opening, breaking the fixed ratio limitations of existing systems that rely on venturi tubes. It can accurately control any gas-liquid mixing ratio within 1:14. Compared to existing systems that can only adapt to a single type of foam liquid (such as only Class A or only Class B foam liquid), this invention can flexibly match the foam liquid ratio requirements of different fire scenarios (such as 3‰-5‰ for Class A foam liquid and 3%-6% for Class B foam liquid), allowing for foam liquid type switching without replacing core components, significantly improving scenario adaptability.

[0021] (2) It meets the strict sequential mixing requirements of the two foam liquids with air, ensuring the fire extinguishing effect. The air compressor assembly's air compressor pipeline is only connected to the gas-liquid mixing device of one set of foam tank assemblies, so that the compressed air is first fully mixed with the component foam liquid in the device, and then the gas-liquid mixture is transported to another gas-liquid mixing device through the connecting pipeline for secondary mixing with the other component foam liquid. This path of first mixing the single component gas-liquid and then mixing the two components ensures the uniqueness of the mixing sequence. In view of the problem that the existing system has no sequential control and the chaotic mixing leads to a decrease in fire extinguishing efficiency, this utility model can be precisely adapted to special fire-fighting scenarios with strict requirements for the mixing sequence (such as some liquid fires that require specific foam liquids to be mixed with air first to form a stable foam film), ensuring that the fire extinguishing performance of the foam mixture meets the standards. Attached Figure Description

[0022] To more clearly illustrate the technical solutions in the embodiments of this application 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 some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0023] Figure 1 This is a schematic diagram of the structure of this utility model;

[0024] In the diagram: 1. Foam tank assembly A, 11. Foam tank A, 12. Foam suction valve A, 13. Foam pump A, 14. Pressure sensor A, 15. Flow sensor A, 16. Foam valve A, 17. Check valve A, 18. Gas-liquid mixing device A.

[0025] 2. Foam tank assembly B; 21. Foam tank B; 22. Foam suction valve B; 23. Foam pump B; 24. Pressure sensor B; 25. Flow sensor B; 26. Foam valve B; 27. Check valve B; 28. Gas-liquid mixing device B.

[0026] 3. Air compressor assembly; 31. Air compressor; 32. Air pressure sensor; 33. Air flow sensor; 34. Air check valve; 35. Compressed air electric ball valve.

[0027] 4. Self-cleaning component; 41. Rinse water tank; 42. Rinse valve A; 43. Rinse valve B;

[0028] 5. Fire monitor assembly; 51. Fire monitor butterfly valve; 52. Fire monitor. Detailed Implementation

[0029] To make the objectives, technical solutions, and advantages of this utility model clearer, the technical solutions of this application will be described in detail below through specific embodiments. It should be understood that the embodiments of this application and the specific features in the embodiments are detailed descriptions of the technical solutions of this application, rather than limitations on the technical solutions of this application. In the absence of conflict, the embodiments of this application and the technical features in the embodiments can be combined with each other.

[0030] In the description of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

[0031] like Figure 1 As shown, a compressed air foam fire extinguishing system includes two sets of foam tank assemblies, an air compressor assembly 3, a fire monitor assembly 5, and a controller;

[0032] The two sets of foam tank assemblies are used to store and transport two different components of foam liquid, and are defined as foam tank assembly A1 and foam tank assembly B2.

[0033] The foam tank assembly A1 includes a foam tank A11, the outlet end of which is connected to a foam pipeline A. A foam pump A13, a pressure sensor A14, a flow sensor A15, a foam valve A16, and a gas-liquid mixing device A18 are sequentially connected in series along the foam liquid conveying direction on the foam pipeline A.

[0034] The foam tank assembly B2 includes a foam tank B21, the outlet end of which is connected to a foam pipeline B. A foam pump B23, a pressure sensor B24, a flow sensor B25, a foam valve B26, and a gas-liquid mixing device B28 are sequentially connected in series along the foam liquid conveying direction on the foam pipeline B.

[0035] The outlet end of the gas-liquid mixing device A18 is connected to the inlet end of the gas-liquid mixing device B28 via a connecting pipe, for conveying the gas-liquid mixture in the gas-liquid mixing device A18 to the gas-liquid mixing device B28.

[0036] The air compressor assembly 3 is used to provide compressed air. It includes an air compressor 31, the outlet end of which is connected to an air compressor pipeline. An air pressure sensor 32, an air flow sensor 33, and a compressed air electric ball valve 35 are sequentially connected in series along the compressed air delivery direction on the air compressor pipeline. The outlet end of the air compressor pipeline is connected to the air inlet of the gas-liquid mixing device A18, which is used to inject compressed air into the gas-liquid mixing device A18. The compressed air is first fully mixed with the foam liquid A delivered by the foam tank A11 in the gas-liquid mixing device A18 to form a gas-liquid mixture. The gas-liquid mixture then enters the gas-liquid mixing device B28, where it is fully mixed again with the foam liquid B delivered by the foam tank B21.

[0037] The fire monitor assembly 5 is used to spray compressed air foam. It includes a fire monitor 52, the inlet end of which is connected to a fire pipeline, and a fire monitor butterfly valve 51 is connected in series on the fire pipeline. The inlet end of the fire pipeline is connected to the outlet end of the gas-liquid mixing device B 28 and is used to receive the compressed air foam output by the gas-liquid mixing device B 28.

[0038] The controller is electrically connected to foam pump A13, foam pump B23, pressure sensor A14, pressure sensor B24, flow sensor A15, flow sensor B25, air compressor 31, air pressure sensor 32, air flow sensor 33, and compressed air electric ball valve 35, respectively. The controller is configured to adjust the rotation speed of foam pump A13, the rotation speed of foam pump B23, the output power of air compressor 31, and the opening degree of compressed air electric ball valve 35 based on the pressure values ​​detected by pressure sensor A14, pressure sensor B24, and air pressure sensor 32, and the flow values ​​detected by flow sensor A15, flow sensor B25, and air flow sensor 33, so as to output compressed air foam with any preset gas-liquid mixing ratio. The compressed air foam is sprayed onto the surface of the object by fire monitor 52 after passing through fire pipeline and fire monitor butterfly valve 51, forming a fireproof isolation zone.

[0039] In some embodiments, such as Figure 1 As shown, each foam tank assembly has a check valve (check valve A17 for foam tank assembly A1 and check valve B27 for foam tank assembly B2) installed in series on its foam pipeline. The check valve is precisely positioned between the foam valve (foam valve A16 and foam valve B26) and the gas-liquid mixing device (gas-liquid mixing device A18 and gas-liquid mixing device B28). Its core function is to prevent the foam liquid in the foam pipeline from flowing backward.

[0040] During the foam liquid delivery phase of firefighting operations, the foam liquid needs to flow from the foam valve to the gas-liquid mixing device. The check valve can prevent the foam liquid from flowing back to the front end of the foam valve due to pipeline pressure fluctuations, ensuring that the two foam liquids are delivered stably along the preset path (foam pump—pressure sensor—flow sensor—foam valve—check valve—gas-liquid mixing device), providing a smooth fluid basis for subsequent staged mixing. Using a check valve can extend the service life of components such as foam pumps and sensors, and reduce the frequency of system maintenance.

[0041] In some embodiments, such as Figure 1 As shown, it also includes a self-cleaning component 4 for cleaning foam pipes. This component, through its independent water path and passage switching design, can thoroughly remove residual foam liquid from the pipes, avoid corrosion and solidification failures, and significantly extend the system life.

[0042] Specifically, on foam pipeline A, a can-suction foam valve A12 is connected in series between foam tank A11 and foam pump A13; on foam pipeline B, a can-suction foam valve B22 is connected in series between foam tank B21 and foam pump B23; the self-cleaning component 4 includes a flushing water tank 41 and two parallel flushing pipelines (denoted as flushing pipeline A and flushing pipeline B). One end of flushing pipelines A and B is connected to the flushing water tank 41, and the other end is connected to the foam pipelines of the two sets of foam tank components. The connection point is precisely set between the can-suction foam valve and the foam pump of each set of foam tank components. That is, the other end of flushing pipeline A is connected to foam pipeline A, and the connection point is located between can-suction foam valve A12 and foam pump A13; the other end of flushing pipeline B is connected to foam pipeline B, and the connection point is located between can-suction foam valve B22 and foam pump B23. Between 23, this layout ensures that flushing water can cover the entire foam pipeline from the foam pump to the gas-liquid mixing unit, avoiding cleaning blind spots;

[0043] Meanwhile, flushing valves A42 and B43, which are connected in series on flushing pipes A and B respectively, are used to control the on / off state of the pipes. Together with the foam tank suction valve, they form a linkage switching mechanism: during fire fighting operations, the foam tank suction valve is opened and the flushing valve is closed to ensure a stable delivery of foam liquid from the foam tank; during self-cleaning operations, the foam tank suction valve is closed (cutting off the foam tank passage to prevent residual foam liquid from flowing back and contaminating the system) and the flushing valve is opened. The flushing water enters the foam pipe from the flushing water tank through the flushing pipe and the foam pump to thoroughly flush the pipe and the gas-liquid mixing device, completely removing the residue of the two-component foam mixture. This prevents the residual liquid from reacting chemically and solidifying to block the pipe and cause system shutdown, and also avoids corrosion of pipe components. At the same time, it ensures that the purity of the foam liquid is not affected by the residue during the next operation, ensuring the accuracy of the mixing ratio and the fire extinguishing effect.

[0044] The working principle of this utility model's compressed air foam fire-fighting system is as follows:

[0045] I. Methods of Implementing Firefighting Operations

[0046] Firefighting operations must be carried out in the following sequence: valve status setting—foam liquid delivery—compressed air injection—proportioning adjustment—foam spraying. The specific steps are as follows:

[0047] (1) Valve initial state setting

[0048] First, open the following valves: foam canister valve A12, foam valve A16, foam canister valve B22, foam valve B26, and fire monitor butterfly valve 51; at the same time, close the following valves: flushing valve A42 and flushing valve B43 to ensure that the self-cleaning component 4 is disconnected from the foam pipeline, preventing clean water from mixing into the foam liquid, ensuring the purity of the foam liquid, and laying the foundation for subsequent accurate mixing.

[0049] (2) Start-up of foam liquid delivery

[0050] Simultaneously start foam pump A13 and foam pump B23: foam pump A13 draws foam liquid A from foam tank A11 (which stores foam liquid A), and delivers it to gas-liquid mixing device A18 through tank suction foam valve A12, pressure sensor A14, flow sensor A15, and foam valve A16.

[0051] Foam pump B 23 draws foam liquid B from foam tank B 21 (which stores foam liquid B), and delivers it to gas-liquid mixing device B 28 via tank suction foam valve B 22, pressure sensor B 24, flow sensor B 25, and foam valve B 26.

[0052] The dual-pump synchronous delivery design ensures that the two foam liquids enter the mixing stage according to the preset parameters, avoiding the mixing lag problem caused by single-pump delivery and improving mixing efficiency.

[0053] (3) Compressed air injection conditions and execution

[0054] When both flow sensor A15 and flow sensor B25 detect a stable flow signal, the air compressor 31 of the air compressor assembly 3 is started.

[0055] Once the compressed air pressure detected by air pressure sensor 32 is slightly greater than the foam liquid pipeline pressure detected by pressure sensors A14 and B24, the compressed air electric ball valve 35 is opened. Compressed air is injected into the gas-liquid mixing device A18 via air pressure sensor 32, air flow sensor 33, and compressed air electric ball valve 35. It is first fully mixed with foam liquid A in the gas-liquid mixing device A18 to form a gas-liquid mixture. This gas-liquid mixture then enters the gas-liquid mixing device B28 through the connecting pipeline and is mixed with foam liquid B a second time to form compressed air foam.

[0056] By adopting a staged mixing method and strictly following the mixing sequence of the two foam liquids and air, compared with disordered mixing, the stability of foam and fire extinguishing efficiency can be greatly improved, making it suitable for special fire scenarios.

[0057] (4) Gas-liquid mixing ratio adjustment and foam injection

[0058] For fixed ratio requirements (such as a final compressed air-foam liquid mixing ratio of 1:14): the controller adjusts the speed of foam pump A13 and foam pump B23, as well as the output power of air compressor 31 and the opening of compressed air electric ball valve 35, to adjust the values ​​of pressure sensor A14, pressure sensor B24 and air pressure sensor 32 to preset values, while stabilizing the ratio of flow sensor A15, air flow sensor 33 and flow sensor B25 at 1:28:1;

[0059] For any required ratio: a preset gas-liquid mixing ratio can be input through the control panel connected to the controller. The controller compares the actual values ​​of flow sensor A15, air flow sensor 33, and flow sensor B 25 with the "preset ratio" in real time, and dynamically adjusts the operating parameters of foam pump A13, foam pump B 23, air compressor 31, and compressed air electric ball valve 35 until the mixing ratio is met. This precise adjustment mechanism breaks the limitation of fixed mixing ratio in traditional systems, enabling arbitrary mixing ratios and adapting to the usage requirements of different types of foam liquids such as Class A and Class B, thus improving the system's adaptability to various scenarios. Compressed air foam enters the fire monitor 52 through the fire monitor butterfly valve 51 and is sprayed onto the surface of the target object by the fire monitor 52, forming a fireproof isolation zone to achieve a flame-retardant extinguishing effect. Moreover, the foam spray is stable and can quickly cover the fire source, improving extinguishing efficiency.

[0060] II. How the self-cleaning function is achieved (after firefighting operations are completed)

[0061] The self-cleaning operation requires that the flushing water tank 41 be filled with clean water in advance, and should be carried out according to the valve status switching - clean water delivery flushing steps, as follows:

[0062] (1) Valve status switching

[0063] First, open the following valves: flushing valve A 42, foam valve A16, flushing valve B 43, foam valve B 26, and fire monitor butterfly valve 51; at the same time, close the following valves: canister suction foam valve A12 and canister suction foam valve B 22, and disconnect the foam canister A11 and foam canister B 21 from the foam pipeline to prevent residual foam liquid from flowing back and contaminating the new liquid in the foam canister, thus ensuring the quality of subsequent foam liquid.

[0064] (2) Clean water delivery and pipeline flushing

[0065] Simultaneously start foam pump A13 and foam pump B23: Foam pump A13 draws clean water from flushing water tank 41 through flushing valve A42, and flows through pressure sensor A14, flow sensor A15, foam valve A16, gas-liquid mixing device A18, connecting pipeline, and gas-liquid mixing device B28 to flush foam pipeline A and mixing device.

[0066] Foam pump B 23 draws clean water from flushing water tank 41 through flushing valve B 43, and flows into gas-liquid mixing device B 28 through pressure sensor B 24, flow sensor B 25, and foam valve B 26 to flush foam pipeline B and mixing device.

[0067] The two flushing water streams eventually converge and are sprayed to the outside through fire monitor butterfly valve 51 and fire monitor 52, thoroughly removing any residual A and B component foam mixture from the pipeline. This self-cleaning function effectively prevents residual liquid from solidifying and clogging the pipeline due to chemical reactions (causing fire trucks to malfunction) or corroding pipeline components, reducing system maintenance costs, extending equipment lifespan, and ensuring that there is no residue in the pipeline before the next operation, guaranteeing the accuracy of the foam mixing ratio and improving the reliability of system operation.

[0068] Furthermore, those skilled in the art will understand that although some embodiments described herein include certain features found in other embodiments but not others, combinations of features from different embodiments are also within the scope of protection of this utility model and form different embodiments. For example, in the embodiments described above, those skilled in the art can use them in combination based on known technical solutions and the technical problems to be solved by this application.

Claims

1. A compressed air foam fire suppression system, characterized in that, include: Two sets of foam tank assemblies are used to store and transport two different foam liquids respectively. Each set of foam tank assemblies includes a foam tank, foam pipeline, and a foam pump, pressure sensor, flow sensor, foam valve, and gas-liquid mixing device connected in series on the foam pipeline. The gas-liquid mixing devices of the two sets of foam tank assemblies are connected by connecting pipelines. An air compressor assembly for providing compressed air includes an air compressor and an air compressor pipeline. An air pressure sensor, an air flow sensor, and a compressed air electric ball valve are connected in series on the air compressor pipeline. The output end of the air compressor pipeline is connected to one of the gas-liquid mixing devices, so that the compressed air is first mixed with the foam liquid in the gas-liquid mixing device. The gas-liquid mixture enters another gas-liquid mixing device through a connecting pipeline and is mixed a second time with another component of foam liquid. A fire monitor assembly for spraying compressed air foam includes a fire monitor and a fire pipeline; a fire monitor butterfly valve is connected in series on the fire pipeline, and the input end of the fire pipeline is connected to a gas-liquid mixing device for receiving gas-liquid mixtures. The controller is electrically connected to the foam pump, pressure sensor, and flow sensor in the foam tank assembly, and the air compressor, air pressure sensor, air flow sensor, and compressed air electric ball valve in the air compressor assembly. The controller adjusts the speed of the foam pump, the output power of the air compressor, and the opening of the compressed air electric ball valve according to the pressure and flow values ​​detected by each sensor, so as to output compressed air foam with any preset gas-liquid mixing ratio. Compressed air foam is sprayed onto the surface of an object through fire-fighting pipes and fire monitors to form a fire-resistant barrier.

2. The compressed air foam fire suppression system according to claim 1, characterized in that, Each foam tank assembly has a check valve installed in series on its foam piping, located between the foam valve and the gas-liquid mixing device, to prevent the foam liquid in the foam piping from flowing backward.

3. The compressed air foam fire suppression system according to claim 1, characterized in that, An air check valve is installed in series on the air compressor pipeline of the air compressor assembly and is located between the air flow sensor and the compressed air electric ball valve to prevent compressed air in the air compressor pipeline from flowing back to the air compressor.

4. A compressed air foam fire suppression system according to claim 1, characterized in that, It also includes a self-cleaning component for cleaning foam tubing, the self-cleaning component comprising a flushing tank and two parallel flushing lines.

5. A compressed air foam fire suppression system according to claim 4, characterized in that, On the foam piping of each foam tank assembly, a foam suction valve is also installed in series between the foam tank and the foam pump to cut off the passage between the foam tank and the foam pump during self-cleaning operations.

6. A compressed air foam fire suppression system according to claim 5, characterized in that, One end of each of the two flushing pipelines is connected to the outlet of the flushing water tank, and the other end is connected to the foam pipeline of each of the two foam tank assemblies. The connection point is located between the foam suction valve and the foam pump of each foam tank assembly.

7. A compressed air foam fire suppression system according to claim 6, characterized in that, Each flushing pipeline is equipped with a flushing valve connected in series. The flushing valve is used to control the opening and closing of the corresponding flushing pipeline and, together with the tank suction foam valve, enables pipeline switching between fire-fighting operations and self-cleaning operations.

8. A fire truck, characterized in that, The fire truck is equipped with a compressed air foam fire extinguishing system as described in any one of claims 1-7.

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