Vacuum type automatic water-spraying fire extinguishing system based on negative pressure regulation

Abstract

This invention provides a vacuum-type automatic sprinkler fire extinguishing system based on negative pressure regulation, including a vacuum unit, a pipe network connected to the vacuum unit via a first suction pipe, negative pressure resistant sprinklers fixedly installed on the pipe network, a suction port shut-off valve installed on the first suction pipe, a suction port regulating valve installed in parallel with the suction port shut-off valve, and a first pressure sensor fixedly installed near the pipe network on the first suction pipe. The first suction pipe between the suction port shut-off valve and the first pressure sensor is connected to a water inlet pipe. The water inlet end of the water inlet pipe is connected to a vacuum pre-action alarm valve group, and the water inlet end of the vacuum pre-action alarm valve group is connected to a fire water supply pipe. This invention utilizes the vacuum unit to precisely control the negative pressure of the pipe network, improving the stability of the negative pressure and solving the problem of pipe network freezing and cracking damage in low-temperature environments. At the same time, it can significantly shorten the pipe network filling time in the early stage of a fire, improve the system response speed, and effectively balance the two major technical effects of antifreeze and rapid response.

Description

Technical Field

[0001] This invention belongs to the field of automatic fire sprinkler technology, and in particular relates to a vacuum-type automatic fire sprinkler system based on negative pressure regulation. Background Technology

[0002] Automatic sprinkler systems are among the most widely used and effective fire extinguishing facilities in the field of building fire protection. Currently, closed-loop automatic sprinkler systems mainly include wet systems, dry systems, and pre-action systems. Among them, wet systems have water-filled pipes all year round, resulting in a fast fire response speed, but they are prone to freezing and cracking in low-temperature environments, making them unsuitable for extremely cold regions. Dry systems do not have water-filled pipes and use compressed air to maintain pipe pressure, providing good anti-freezing performance, but the pipe filling time is relatively long, resulting in a slow response speed, which is not conducive to the rapid control of initial fires. Pre-action systems combine the advantages of wet and dry systems. Normally, the pipes are not filled with water, and in the event of a fire, the fire detectors first alarm, and then the pre-action valve is opened to fill the pipes with water. However, the filling speed is still limited by factors such as pipe network structure and pressure supply, making it difficult to meet the stringent requirements for fire extinguishing response speed in low-temperature environments.

[0003] In cold regions, in places where fires spread rapidly, such as warehouses, factories, and low-temperature cold storage facilities, slow water filling can lead to an inability to control the fire in its early stages, causing the fire to expand and resulting in serious casualties and property damage.

[0004] Therefore, in response to the technical pain points of existing automatic sprinkler fire extinguishing systems, such as slow response speed and inability to balance antifreeze and rapid response effects, there is an urgent need to develop a vacuum-type automatic sprinkler fire extinguishing system based on negative pressure regulation to meet the fire protection needs of different scenarios. Summary of the Invention

[0005] The problem this invention aims to solve is to provide a vacuum-type automatic sprinkler fire extinguishing system based on negative pressure regulation. By using a vacuum unit to precisely control the negative pressure of the pipeline network, the system improves the stability of the negative pressure and solves the problem of pipeline freezing and cracking damage in low-temperature environments. At the same time, it can significantly shorten the pipeline filling time in the early stage of a fire, improve the system response speed, and effectively take into account both the anti-freezing and rapid response technical effects.

[0006] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is: a vacuum-type automatic sprinkler fire extinguishing system based on negative pressure regulation, comprising a vacuum unit, a pipe network connected to the vacuum unit via a first suction pipe, a negative pressure resistant sprinkler head fixedly installed on the pipe network, a suction port shut-off valve installed on the first suction pipe, a suction port regulating valve installed in parallel with the suction port shut-off valve, and a first pressure sensor fixedly installed on the first suction pipe near the pipe network. The first suction pipe between the suction port shut-off valve and the first pressure sensor is connected to a water inlet pipe. The water inlet end of the water inlet pipe is connected to a vacuum pre-action alarm valve group, and the water inlet end of the vacuum pre-action alarm valve group is connected to a fire water source pipe.

[0007] Furthermore, the vacuum unit includes a first vacuum pump and a second vacuum pump. The outlets of both the first and second vacuum pumps are connected to the gas-water separator pipeline. The inlets of both the first and second vacuum pumps are connected to a second suction pipeline. The inlet of the second suction pipeline is connected to the vacuum tank through a third suction pipeline. A vacuum check valve and a pump suction port shut-off valve are installed on the second suction pipeline. A second pressure sensor is installed on the vacuum tank. The first suction pipeline is connected to the vacuum tank of the vacuum unit.

[0008] Furthermore, the steam-water separator is equipped with a thermocouple, a water level gauge, and an exhaust port located above the steam-water separator. The inlet water pipe of the steam-water separator is equipped with an inlet pneumatic valve, and the outlet water pipe of the steam-water separator is equipped with a drain valve.

[0009] Furthermore, an intake branch connected in parallel with the vacuum tank is provided between the first intake pipe and the third intake pipe. A third pressure sensor and a bypass valve are provided on the intake branch. A tank opening shut-off valve is provided on the side of the first intake pipe and the third intake pipe near the vacuum tank.

[0010] Furthermore, the negative pressure resistant nozzle includes a connector connected to the pipeline network, a seal connected to the nozzle of the connector via a sealing structure, a nozzle seat located directly below the seal, a splash plate fixedly connected to the nozzle seat, a support rod assembly symmetrically arranged between the connector and the nozzle seat, a pre-tightening screw coaxially screwed and fixed in the nozzle seat, and a balancing assembly arranged between the seal and the pre-tightening screw.

[0011] Furthermore, the sealing element includes a first stepped surface that contacts the inner wall of the joint and a second stepped surface that contacts the lower end face of the joint. The sealing structure includes a first sealing gasket disposed on the first stepped surface, a second sealing gasket disposed on the second stepped surface, and an annular gap formed between the joint and the sealing element. The annular gap is located between the first stepped surface and the second stepped surface.

[0012] Furthermore, the support rod assembly includes a first support rod and a second support rod. One end of the first support rod is hinged to the side wall of the connector, and the other end of the first support rod is provided with a sliding groove. One end of the second support rod is provided with a sliding column that matches the sliding groove. The first support rod and the second support rod are slidably connected through the sliding groove and the sliding column. The other end of the second support rod is fixedly connected to the nozzle seat. A telescopic spring is fixedly provided between the first support rod and the second support rod. An inclined support rod is provided on the side of the first support rod near the connector. The free end of the inclined support rod is located above the second stepped surface. The sliding column includes, from bottom to top, a sliding part, a positioning part, and a connecting part for connecting with the second support rod. The sliding part is a cylindrical structure with an arc-shaped lower end. The positioning part is an iron ring structure fixedly provided around the side wall of the sliding part. The sliding part and the positioning part are located in the sliding groove. A positioning frame for limiting the positioning part is provided at the opening of the sliding groove. A positioning hole that matches the sliding part is provided at the end of the sliding groove near the connector. A strong magnet that matches the positioning part is fixedly provided on the circumference of the positioning hole.

[0013] Furthermore, the balancing assembly includes a balancing plate, an L-shaped balancing frame, a support, and a thermal component. The balancing plate rests against the lower end of the sealing element via a support member. The upper end of the L-shaped balancing frame rests against one end of the balancing plate, and the other end of the L-shaped balancing frame rests against a pre-tightening screw via a steel ball. Both ends of the support rest against the balancing plate and the L-shaped balancing frame, respectively. The thermal component is located between the support and the balancing plate. The thermal component includes a base resting against the support, a placement groove on the base, a fusible alloy component placed in the placement groove, and a top column that is slidably connected to the placement groove and rests against the fusible alloy component and the support.

[0014] Furthermore, the vacuum unit also includes a vacuum unit PLC controller. The output terminals of the first pressure sensor, the second pressure sensor, the third pressure sensor, and the thermocouple are electrically connected to the input terminal of the vacuum unit PLC controller. The output terminal of the vacuum unit PLC controller is electrically connected to the input terminals of the suction port shut-off valve, the suction port regulating valve, the first vacuum pump, the second vacuum pump, and the water inlet pneumatic valve, respectively.

[0015] Furthermore, it also includes a PLC main controller, which is equipped with a timing module for the intake port shut-off valve, a timing module for the intake port regulating valve, and a pipeline leakage alarm module. The input terminal of the PLC main controller is electrically connected to the fire monitoring system, which is equipped with a fire early warning module and a fire alarm module. The output terminal of the PLC main controller is electrically connected to the vacuum pre-action alarm valve group. The vacuum unit PLC controller and the PLC main controller communicate via an RS485 interface.

[0016] Compared with the prior art, the advantages and beneficial effects of the present invention are as follows:

[0017] 1. This invention achieves stable negative pressure control of the pipeline network by setting up a vacuum unit in conjunction with the suction port shut-off valve and suction port regulating valve on the first suction pipe. This can effectively prevent pipeline freezing and cracking in low-temperature environments. At the same time, in the event of a fire alarm, the vacuum unit can quickly evacuate the pipeline network. When a fire alarm is triggered, the system can quickly activate the vacuum pre-action alarm valve group. Combined with the low air resistance design of the negative pressure pipeline network, it can achieve rapid response and effectively control the fire in its initial stage. This invention effectively solves the technical problem that traditional systems cannot simultaneously address both antifreeze and rapid response, and is suitable for the needs of use in extremely cold regions.

[0018] 2. This invention installs a first pressure sensor on the first suction pipe to monitor the pipeline pressure in real time, and sets an upper limit and a lower limit for the pipeline pressure. When the pipeline pressure is greater than or equal to the upper limit, the suction port regulating valve can be opened, and the vacuum tank of the vacuum unit inputs negative pressure (suction) into the pipeline. When the pipeline pressure is less than the lower limit, the suction port regulating valve is closed, and the negative pressure delivery is stopped. Through the cooperation of the vacuum unit and the suction port regulating valve, a stable supply of negative pressure can be achieved, ensuring that the pipeline is always maintained within the preset negative pressure range, significantly improving the system's responsiveness and reliability. In addition, the system sets an upper limit for the suction time after the suction port regulating valve is opened. If the suction time is greater than or equal to the upper limit and the pipeline pressure has not yet dropped to the lower limit, the system will issue a pipeline leakage warning to ensure the safety and reliability of the system.

[0019] 3. The negative pressure resistant nozzle used in this invention, through a sealing structure composed of a first sealing gasket, a second sealing gasket, and an annular gap, ensures that under negative pressure in the pipeline network, the pressure inside the joint cavity is the same as the pipeline network pressure. Since the pressure inside the annular gap is greater than the pressure inside the joint cavity, the sealing effect of the first sealing gasket under negative pressure is improved due to the pressure difference. At the same time, the second stepped surface contacts the lower end of the joint and is equipped with a second sealing gasket, enabling the sealing element to withstand the vacuum pressure and prevent it from being sucked into the pipeline network, thus improving the sealing effect of the pipeline network. In addition, when a fire occurs and the balancing component loses its balance and falls, to prevent the sealing element from not falling in time due to the vacuum state and affecting the water spraying fire extinguishing, the first and second support rods, under the action of the telescopic spring, drive the splash plate to move upward. Under the instantaneous upward force, the tilting support rod gives the second stepped surface of the sealing element a downward impact force, while the impact force of the water flow ensures that the sealing element smoothly detaches from the joint, achieving rapid water spraying fire extinguishing. Attached Figure Description

[0020] The above and / or additional aspects and advantages of the present invention will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, in which:

[0021] Figure 1This is an overall flowchart of a vacuum-type automatic sprinkler fire extinguishing system based on negative pressure regulation according to the present invention.

[0022] Figure 2 This is a schematic diagram of the vacuum unit of a vacuum-type automatic sprinkler fire extinguishing system based on negative pressure regulation according to the present invention.

[0023] Figure 3 yes Figure 2 A top-view structural diagram.

[0024] Figure 4 This is a schematic diagram of the structure of a negative pressure resistant sprinkler head for a vacuum-type automatic sprinkler fire extinguishing system based on negative pressure regulation according to the present invention.

[0025] Figure 5 This is a partial structural diagram of the first and second support rods of the negative pressure resistant nozzle.

[0026] Figure 6 This is a schematic cross-sectional view of the sliding connection between the first and second support rods of the negative pressure resistant nozzle.

[0027] Figure 7 This is a control flow diagram of a vacuum-type automatic sprinkler fire extinguishing system based on negative pressure regulation according to the present invention.

[0028] In the diagram: 1-First intake pipe; 2-Pipe network; 3-Negative pressure resistant nozzle; 4-Intake port shut-off valve; 5-Intake port regulating valve; 6-First pressure sensor; 7-Water inlet pipe; 8-Vacuum pre-action alarm valve assembly; 9-Fire water source; 10-First vacuum pump; 11-Second vacuum pump; 12-Steam-water separator; 13-Second intake pipe; 14-Third intake pipe; 15-Vacuum tank; 16-Vacuum check valve; 17-Pump intake port shut-off valve; 18-Second pressure sensor; 19-Thermocouple; 20-Water level gauge; 21-Exhaust port; 22-Water inlet pneumatic valve; 23-Drain valve; 24-Intake branch; 25-Third pressure sensor; 26-Bypass valve; 27-Tank port shut-off valve; 28-Connector; 29-Seal; 30-Nozzle head seat; 31-Splash plate; 32-Pre-tightening screw; 33-First stepped surface; 4-Second stepped surface; 35-First sealing gasket; 36-Second sealing gasket; 37-Annular gap; 38-First support rod; 39-Second support rod; 40-Slide groove; 41-Slide column; 42-Telescopic spring; 43-Inclined support rod; 44-Sliding part; 45-Positioning part; 46-Connecting part; 47-Positioning frame; 48-Positioning hole; 49-Strong magnet; 50-Balance plate; 51-L-shaped balance frame; 52-Bracket; 53-Supporting component; 54-Steel ball; 55-Base; 56-Placement groove; 57-Fuse alloy part; 58-Top column; 59-Vacuum unit PLC controller; 60-PLC main controller; 61-Suction port shut-off valve timing module; 62-Suction port regulating valve timing module; 63-Pipeline leakage alarm module; 64-Fire monitoring system; 65-Fire early warning module; 66-Fire alarm module. Detailed Implementation

[0029] To better understand the above-mentioned objects, features, and advantages of the present invention, the following description is provided. Figure 1-7 The present invention will be further described in detail below with reference to specific embodiments. It should be noted that, unless otherwise specified, the technical solutions and features of the present application can be combined with each other.

[0030] Many specific details are set forth in the following description in order to provide a full understanding of the invention. However, the invention may also be implemented in other ways different from those described herein. Therefore, the scope of protection of the invention is not limited to the specific technical solutions disclosed below.

[0031] The technical solution of the present invention will now be described with reference to specific embodiments. These embodiments are only a part of the embodiments of the present invention, and not all of them. All other embodiments obtained by those skilled in the art based on the present invention without creative effort are within the scope of protection of the present invention.

[0032] The technical solution of the present invention provides a vacuum-type automatic sprinkler fire extinguishing system based on negative pressure regulation, including a vacuum unit, a pipe network 2 connected to the vacuum unit via a first suction pipe 1, a negative pressure resistant sprinkler head 3 fixedly installed on the pipe network 2, a suction port shut-off valve 4 installed on the first suction pipe 1, a suction port regulating valve 5 installed in parallel with the suction port shut-off valve 4, and a first pressure sensor 6 fixedly installed near the pipe network 2 on the first suction pipe 1. The first suction pipe 1 between the suction port shut-off valve 4 and the first pressure sensor 6 is connected to a water inlet pipe 7. The water inlet end of the water inlet pipe 7 is connected to a vacuum pre-action alarm valve group 8, and the water inlet end of the vacuum pre-action alarm valve group 8 is connected to a fire water source 9 pipe.

[0033] Specifically, upon system startup, the suction port shut-off valve 4 and suction port regulating valve 5 are first closed, and the vacuum unit is turned on to ensure stable pressure. Then, the suction port regulating valve 5 is opened, and the vacuum unit is used to draw air from pipeline 2, maintaining the negative pressure of pipeline 2 between -0.06MPa and -0.03MPa. When the first pressure sensor 6 detects that the pressure in pipeline 2 is less than -0.06MPa, the suction port regulating valve 5 is closed. The opening and closing of the suction port regulating valve 5 are controlled by the upper and lower limits of the pipeline 2 pressure, thereby achieving daily operation. To stabilize the negative pressure in pipeline 2, when a fire alarm signal is received, the suction port shut-off valve 4 is opened and the suction port regulating valve 5 is closed. The vacuum unit quickly delivers negative pressure (suction) to pipeline 2, enabling pipeline 2 to achieve a negative pressure vacuum state. When a fire alarm signal is received, the suction port shut-off valve 4 is closed and the vacuum unit stops operating. The vacuum pre-action alarm valve group 8 is opened to quickly fill pipeline 2 with water. When the temperature reaches the action temperature of the thermal element of the negative pressure resistant sprinkler head 3, the system immediately switches from water filling state to water spraying state, quickly controlling and extinguishing the initial fire and preventing the fire from spreading.

[0034] This invention achieves stable negative pressure control of the pipeline network 2 by setting up a vacuum unit in conjunction with the suction port shut-off valve 4 and suction port regulating valve 5 on the first suction pipe 1. This effectively prevents the pipeline from freezing and cracking in low-temperature environments. At the same time, in the event of a fire alarm, the vacuum unit quickly evacuates the pipeline network 2. When a fire alarm is triggered, the system can quickly activate the vacuum pre-action alarm valve group 8. Combined with the low air resistance design of the negative pressure pipeline network, a rapid response is achieved, effectively controlling the fire in its initial stage. This invention effectively solves the technical problem that traditional systems cannot simultaneously address both antifreeze and rapid response, and is suitable for the needs of use in extremely cold regions.

[0035] Among them, the air intake shut-off valve 4 can be an electromagnetic pneumatic butterfly valve, the air intake regulating valve 5 is an electric valve, the pipeline network 2 is designed as a branch or ring network structure, the end of the pipeline network 2 is sealed with a plug, the vacuum pre-action alarm valve group abandons the air-filling pressure-maintaining approach and adopts a negative pressure vacuum differential pressure sealing structure, and adds a negative pressure one-way valve to lock the vacuum and a drainage lock valve to seal the cavity. It relies on the pressure difference between the negative pressure of the pipeline network and the positive pressure of the inlet water to achieve responsive sealing. After receiving the fire warning signal, the valve can be opened to supply water.

[0036] Furthermore, the vacuum unit includes a first vacuum pump 10 and a second vacuum pump 11. The outlets of the first vacuum pump 10 and the second vacuum pump 11 are both connected to the pipeline of the steam-water separator 12. The inlets of the first vacuum pump 10 and the second vacuum pump 11 are both connected to a second suction pipeline 13. The inlet of the second suction pipeline 13 is connected to the vacuum tank 15 through a third suction pipeline 14. A vacuum check valve 16 and a pump suction port shut-off valve 17 are installed on the second suction pipeline 13. A second pressure sensor 18 is installed on the vacuum tank 15. The first suction pipeline 1 is connected to the vacuum tank 15 of the vacuum unit.

[0037] Specifically, firstly, the vacuum unit achieves automatic pressure maintenance of the vacuum tank 15 by alternating operation of the first vacuum pump 10 and the second vacuum pump 11. This allows for setting upper and lower pressure limits for the vacuum tank 15. The second pressure sensor 18 monitors the pressure inside the vacuum tank 15 in real time. When the pressure inside the vacuum tank 15 is greater than or equal to the upper limit, the first vacuum pump 10 and the second vacuum pump 11 are alternately activated to supply negative pressure to the vacuum tank 15. When the pressure inside the vacuum tank 15 is less than the lower limit, the first vacuum pump 10 and the second vacuum pump 11 are shut down, thus ensuring stable negative pressure in the vacuum tank 15. In the event of a fire alarm, the automatic pressure maintenance function of the vacuum tank is deactivated, and the first vacuum pump 10 and the second vacuum pump 11 are activated simultaneously to quickly deliver negative pressure to the pipeline network 2. The vacuum check valve 16 is a liquid-blocking solenoid valve that opens and closes with the start and stop of the corresponding pumps.

[0038] Furthermore, the steam-water separator 12 is equipped with a thermocouple 19, a water level gauge 20, and an exhaust port 21 located above the steam-water separator 12. The steam-water separator 12 is equipped with an inlet pneumatic valve 22 on its inlet pipe and a drain valve 23 on its outlet pipe.

[0039] Specifically, the steam-water separator 12 mainly separates water vapor from the gas, making the airflow entering the vacuum pump more uniform and dry, providing a stable gas source for the vacuum pump and enabling it to work continuously and efficiently. Thermocouple 19 is installed on the steam-water separator 12 to monitor the temperature of the liquid inside the steam-water separator 12 in real time. When the temperature is too high, the water inlet pneumatic valve 22 is opened to pump in cold water to cool the steam-water separator 12. When the water level gauge 20 detects that the water level inside the steam-water separator 12 is too high, the water is discharged by opening the drain valve 23, effectively ensuring the efficient operation of the vacuum pump.

[0040] Furthermore, an intake branch 24 connected in parallel with the vacuum tank 15 is provided between the first intake pipe 1 and the third intake pipe 14. The intake branch 24 is equipped with a third pressure sensor 25 and a bypass valve 26. A tank opening shut-off valve 27 is provided on the side of the first intake pipe 1 and the third intake pipe 14 near the vacuum tank 15.

[0041] Specifically, when the vacuum tank 15 needs maintenance, the pressure of the pipeline network 2 can be maintained by closing the tank opening shut-off valve 27 and opening the bypass valve 26 through the suction branch 24, which can ensure the normal operation of the system during the maintenance of the vacuum tank 15. The third pressure sensor 25 is used to monitor the pressure value in the suction branch 24 in real time.

[0042] Furthermore, the negative pressure resistant nozzle 3 includes a connector 28 connected to the pipe network 2, a sealing element 29 connected to the nozzle of the connector 28 via a sealing structure, a nozzle seat 30 located directly below the sealing element 29, a splash plate 31 fixedly connected to the nozzle seat 30, a support rod assembly symmetrically arranged between the connector 28 and the nozzle seat 30, a pre-tightening screw 32 coaxially screwed and fixed in the nozzle seat 30, and a balancing assembly arranged between the sealing element 29 and the pre-tightening screw 32.

[0043] Further, the sealing element 29 includes a first stepped surface 33 that contacts the inner wall of the connector 28 and a second stepped surface 34 that contacts the lower end face of the connector 28. The sealing structure includes a first sealing gasket 35 disposed on the first stepped surface 33, a second sealing gasket 36 disposed on the second stepped surface 34, and an annular gap 37 formed between the connector 28 and the sealing element 29. The annular gap 37 is located between the first stepped surface 33 and the second stepped surface 34. Through the sealing structure composed of the first sealing gasket 35, the second sealing gasket 36, and the annular gap 37, under the negative pressure state of the pipeline network 2, the pressure inside the connector 28 is reduced. The pressure is the same as that of the pipe network 2. Since the pressure in the annular gap 37 is greater than the pressure in the inner cavity of the connector 28, the sealing effect of the first sealing gasket 35 under negative pressure is improved under the action of pressure difference. At the same time, the second stepped surface 34 contacts the lower end of the connector 28 and a second sealing gasket 36 is provided, so that the sealing element 29 can withstand the vacuum pressure and prevent it from being sucked into the pipe network 2. At the same time, the sealing effect of the pipe network 2 is improved. The first sealing gasket 35 and the second sealing gasket 36 are both made of silicone rubber, which has the characteristics of low temperature resistance, so that it still has a good sealing effect in low temperature environment and extends the service life of the negative pressure resistant nozzle 3.

[0044] Further, the support rod assembly includes a first support rod 38 and a second support rod 39. One end of the first support rod 38 is hinged to the side wall of the connector 28, and the other end of the first support rod 38 is provided with a sliding groove 40. One end of the second support rod 39 is provided with a sliding column 41 that matches the sliding groove 40. The first support rod 38 and the second support rod 39 are slidably connected through the sliding groove 40 and the sliding column 41. The other end of the second support rod 39 is fixedly connected to the nozzle seat 30. A telescopic spring 42 is fixedly provided between the first support rod 38 and the second support rod 39. An inclined support rod 43 is provided on the side of the first support rod 38 near the connector 28. The free end of 43 is located above the second stepped surface 34. The sliding column 41 includes, from bottom to top, a sliding part 44, a positioning part 45, and a connecting part 46 for connecting with the second support rod 39. The sliding part 44 is a cylindrical structure with an arc-shaped lower end. The positioning part 45 is an iron ring structure fixedly arranged around the side wall of the sliding part 44. The sliding part 44 and the positioning part 45 are located in the slide groove 40. The opening of the slide groove 40 is provided with a positioning frame 47 for limiting the positioning part 45. The end of the slide groove 40 near the connector 28 is provided with a positioning hole 48 that matches the sliding part 44. A strong magnet 49 that matches the positioning part 45 is fixedly arranged on the circumference of the positioning hole 48.

[0045] Further, the balancing assembly includes a balancing plate 50, an L-shaped balancing frame 51, a bracket 52, and a thermal component. The balancing plate 50 is supported against the lower end of the sealing member 29 by a support member 53. The upper end of the L-shaped balancing frame 51 is supported against one end of the balancing plate 50, and the other end of the L-shaped balancing frame 51 is supported against the pre-tightening screw 32 by a steel ball 54. The two ends of the bracket 52 are respectively supported between the balancing plate 50 and the L-shaped balancing frame 51. The thermal component is located between the bracket 52 and the balancing plate 50. The thermal component includes a base 55 supported against the bracket 52, a placement groove 56 provided on the base 55, a fusible alloy component 57 disposed in the placement groove 56, and a top column 58 slidably connected to the placement groove 56 and supported between the fusible alloy component 57 and the bracket 52.

[0046] Specifically, the negative pressure resistant nozzle 3 is held in stable connection by the balancing assembly against the seal 29 and the pre-tightening screw 32. At this time, the telescopic spring 42 between the first support rod 38 and the second support rod 39 is in a stretched state. When a fire alarm occurs, the indoor temperature rises rapidly, and the fusible alloy part 57 in the heat-sensitive element melts rapidly, causing the top column 58 to slide into the placement groove 56. The entire balancing assembly loses its balance and collapses. At the moment the balancing assembly loses its balance and falls, the first support rod 38 and the second support rod 39 move upward instantaneously under the force of the telescopic spring 42. Under the instantaneous upward force, the tilting support rods... 43 applies a downward impact force to the second stepped surface 34 of the seal 29, while simultaneously ensuring that the seal 29 smoothly detaches from the joint 28 under the impact of the water flow, thus achieving rapid water spraying for fire extinguishing. After the seal 29 detaches, under the action of water pressure impacting the splash plate 31, the first support rod 38 and the second support rod 39 rotate and slide at the connection point. The sliding column 41 moves upward in the sliding groove 40 until the sliding column 41 enters the positioning hole 48. The positioning part 45 achieves fixed positioning through the attraction force of the strong magnet 49, so that a stable structure is formed between the first support rod 38 and the second support rod 39, thereby fixing the splash plate 31 and improving the water spraying fire extinguishing effect.

[0047] Furthermore, the vacuum unit also includes a vacuum unit PLC controller 59. The output terminals of the first pressure sensor 6, the second pressure sensor 18, the third pressure sensor 25, and the thermocouple 19 are electrically connected to the input terminals of the vacuum unit PLC controller 59. The output terminals of the vacuum unit PLC controller 59 are electrically connected to the input terminals of the suction port shut-off valve 4, the suction port regulating valve 5, the first vacuum pump 10, the second vacuum pump 11, and the water inlet pneumatic valve 22, respectively.

[0048] Specifically, the temperature signal of the steam-water separator 12 is provided by thermocouple 19. After thermocouple 19 is connected to the display, the output is connected to the PLC controller 59 of the vacuum unit. The user can read the temperature signal of the steam-water separator 12 in real time on the display. The upper and lower limits of the temperature control of the steam-water separator 12 are set in the display. The water inlet pneumatic valve 22, with switch position feedback, is connected to the PLC controller 59 of the vacuum unit. The temperature signal of thermocouple 19 controls the opening and closing of the water inlet pneumatic valve 22 within the temperature range. The second pressure sensor 18 is connected to a digital display for setting the pressure of the vacuum tank 1. The upper and lower pressure limits of the vacuum tank 15 are transmitted to the vacuum unit PLC controller 59 via the second pressure sensor 18. The vacuum unit PLC controller 59 then controls the first vacuum pump 10 and the second vacuum pump 11 to automatically start and stop within the pressure range and operate alternately. The first pressure sensor 6 is used to monitor the pressure data in the pipeline network 2 and set the upper and lower pressure limits of the pipeline network 2. The first pressure sensor 6 transmits the data signal to the vacuum unit PLC controller 59 and controls the intake regulating valve 5 to open and close within the pressure range.

[0049] Furthermore, it also includes a PLC main controller 60, which is equipped with a suction port shut-off valve timing module 61, a suction port regulating valve timing module 62, and a pipeline leakage alarm module 63. The input terminal of the PLC main controller 60 is electrically connected to the fire monitoring system 64, which is equipped with a fire early warning module 65 and a fire alarm module 66. The output terminal of the PLC main controller 60 is electrically connected to the vacuum pre-action alarm valve group 8. The vacuum unit PLC controller 59 communicates with the PLC main controller 60 via an RS485 interface, and the signal protocol is ModBus RTU.

[0050] Specifically, the PLC main controller 60 sets the upper limit of the suction time after the suction port shut-off valve timing module 61 is opened, and sets the upper limit of the suction time after the suction port regulating valve timing module 62 is opened. By setting the upper limit of the suction time, the leakage of pipeline 2 is judged. If the suction time is greater than or equal to the upper limit and the pressure of pipeline 2 has not decreased to the lower pressure limit, the pipeline leakage alarm module 63 will issue an alarm warning. In addition, the PLC main controller 60 is electrically connected to the fire monitoring system 64. The fire monitoring system 64 judges the fire warning signal and the fire alarm signal and transmits the signal to the PLC main controller 60. When a fire warning signal is received, the system controls the suction port regulating valve 5 to close and the suction port shut-off valve 4 to open. At the same time, the first vacuum pump 10 and the second vacuum pump 11 are started to quickly evacuate pipeline 2. When a fire alarm signal is received, the system closes the suction port shut-off valve 4, shuts down the vacuum system, controls the vacuum pre-action alarm valve group 8 to open, and quickly fills pipeline 2 with water. The water filling time is shortened to between 10-20 seconds to achieve rapid response.

[0051] Among them, the fire monitoring system 64 issues fire warning signals and fire alarm signals based on the judgment method built into the fire alarm host, that is, based on the judgment of multiple signals such as smoke detectors and environmental monitoring cameras. This judgment mechanism is not the protected content of this invention, so it will not be described in detail.

[0052] The working process of this invention is as follows: First, the vacuum unit includes an automatic vacuum tank pressure maintenance function. Specifically, an upper and lower limit value for the internal pressure of the vacuum tank is set via a digital display. When the second pressure sensor detects that the internal pressure value of the vacuum tank is greater than or equal to the upper limit value, the automatic vacuum tank pressure maintenance function is activated. At this time, the first and second vacuum pumps work alternately. When the pressure inside the vacuum tank is less than the lower limit value, the automatic vacuum tank pressure maintenance function is deactivated. The automatic vacuum tank pressure maintenance function ensures a stable negative pressure environment for the vacuum unit, acting as a standard negative pressure source to provide a vacuum environment for the automatic sprinkler fire extinguishing system pipeline network. Therefore, when the automatic vacuum tank pressure maintenance function is activated, the pipeline network pressure is automatically maintained. The logic is as follows: the upper and lower limits of the pipeline pressure can be set locally through the control cabinet where the PLC main controller is located, or remotely through a remote switch point set in the PLC main controller. When the first pressure sensor detects that the pipeline pressure is greater than or equal to the upper limit, it controls the intake regulating valve to open, and the vacuum unit inputs negative pressure into the pipeline. When the pipeline pressure is less than the lower limit, it closes the intake regulating valve and stops the negative pressure delivery. At the same time, under the automatic pipeline pressure maintenance function, the intake time is started after the intake regulating valve is opened. If the pipeline pressure has not dropped to the lower limit after the intake time is greater than or equal to the upper limit, a pipeline leakage warning is issued and the intake regulating valve is closed. Therefore, under normal conditions, the vacuum unit maintains the pipeline vacuum state while playing a leak detection role.

[0053] Upon receiving a fire warning signal, the automatic pressure maintenance function of the vacuum tank is turned off, the operation of the vacuum pump is no longer controlled by the digital display, the suction port shut-off valve is opened, the suction port regulating valve is closed, the suction time is started, and the first and second vacuum pumps are started simultaneously to quickly input negative pressure (suction) into the pipeline network, significantly reducing the pipeline filling time.

[0054] Upon receiving a fire alarm signal, close the intake shut-off valve, disconnect the vacuum system, activate the vacuum pre-action alarm valve group, and quickly fill the pipeline with water. Once the heat-sensitive element of the negative pressure resistant sprinkler head melts, spray water to extinguish the fire immediately.

[0055] To further verify the superiority of the system of the present invention, fire extinguishing comparison tests were conducted using the system of the present invention and a traditional pre-action system in the same warehouse environment:

[0056] The warehouse environment is as follows: Taking a warehouse in a frigid region as an example, it covers an area of ​​1,000 square meters, has a floor height of 8 meters, and the lowest winter temperature is -25℃.

[0057] The experimental results are shown in the table below:

[0058] System type Pipeline filling time (s) Antifreeze performance (-25℃) This invention system 90.5 Good (no cracking) Traditional pre-action system 105 Good (no cracking)

[0059] The test results show that the pipeline filling time of the system of the present invention is significantly shorter than that of the traditional pre-action system, and it has good antifreeze performance, which can effectively improve the fire extinguishing efficiency. It is fully applicable to the fire protection needs of high-risk places in extremely cold regions and has broad application value.

[0060] The above are merely preferred embodiments of the present invention and are not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A vacuum-type automatic sprinkler fire extinguishing system based on negative pressure regulation, characterized in that: The system includes a vacuum unit, a pipe network connected to the vacuum unit via a first suction pipe, a negative pressure resistant nozzle fixedly installed on the pipe network, a suction port shut-off valve installed on the first suction pipe, a suction port regulating valve installed in parallel with the suction port shut-off valve, and a first pressure sensor fixedly installed on the first suction pipe near the pipe network. The first suction pipe between the suction port shut-off valve and the first pressure sensor is connected to a water inlet pipe. The water inlet end of the water inlet pipe is connected to a vacuum pre-action alarm valve group, and the water inlet end of the vacuum pre-action alarm valve group is connected to a fire water supply pipe.

2. The vacuum-type automatic sprinkler fire extinguishing system based on negative pressure regulation according to claim 1, characterized in that: The vacuum unit includes a first vacuum pump and a second vacuum pump. The outlets of both the first and second vacuum pumps are connected to the gas-water separator pipeline. The inlets of both the first and second vacuum pumps are connected to a second suction pipeline. The inlet of the second suction pipeline is connected to the vacuum tank through a third suction pipeline. A vacuum check valve and a pump suction port shut-off valve are installed on the second suction pipeline. A second pressure sensor is installed on the vacuum tank. The first suction pipeline is connected to the vacuum tank of the vacuum unit.

3. A vacuum-type automatic sprinkler fire extinguishing system based on negative pressure regulation according to claim 2, characterized in that: The steam-water separator is equipped with a thermocouple, a water level gauge, and an exhaust port located above the steam-water separator. The steam-water separator's inlet pipe is equipped with an inlet pneumatic valve, and the steam-water separator's outlet pipe is equipped with a drain valve.

4. A vacuum-type automatic sprinkler fire extinguishing system based on negative pressure regulation according to claim 3, characterized in that: A suction branch connected in parallel with the vacuum tank is provided between the first suction line and the third suction line. A third pressure sensor and a bypass valve are provided on the suction branch. A tank opening shut-off valve is provided on the side of the first suction line and the third suction line near the vacuum tank.

5. A vacuum-type automatic sprinkler fire extinguishing system based on negative pressure regulation according to claim 1, characterized in that: The negative pressure resistant nozzle includes a connector connected to the pipeline network, a seal connected to the nozzle of the connector via a sealing structure, a nozzle seat located directly below the seal, a splash plate fixedly connected to the nozzle seat, a support rod assembly symmetrically arranged between the connector and the nozzle seat, a pre-tightening screw coaxially screwed and fixed in the nozzle seat, and a balancing assembly arranged between the seal and the pre-tightening screw.

6. A vacuum-type automatic sprinkler fire extinguishing system based on negative pressure regulation according to claim 5, characterized in that: The sealing element includes a first stepped surface that contacts the inner wall of the joint and a second stepped surface that contacts the lower end face of the joint. The sealing structure includes a first sealing gasket disposed on the first stepped surface, a second sealing gasket disposed on the second stepped surface, and an annular gap formed between the joint and the sealing element. The annular gap is located between the first stepped surface and the second stepped surface.

7. A vacuum-type automatic sprinkler fire extinguishing system based on negative pressure regulation according to claim 6, characterized in that: The support rod assembly includes a first support rod and a second support rod. One end of the first support rod is hinged to the side wall of the connector, and the other end of the first support rod is provided with a groove. One end of the second support rod is provided with a sliding column that matches the groove. The first support rod and the second support rod are slidably connected through the groove and the sliding column. The other end of the second support rod is fixedly connected to the nozzle seat. A telescopic spring is fixedly provided between the first support rod and the second support rod. An inclined support rod is provided on the side of the first support rod near the connector. The free end of the inclined support rod is located above the second stepped surface. The sliding column includes, from bottom to top, a sliding part, a positioning part, and a connecting part for connecting with the second support rod. The sliding part is a cylindrical structure with an arc-shaped lower end. The positioning part is an iron ring structure fixedly provided around the side wall of the sliding part. The sliding part and the positioning part are located in the groove. A positioning frame for limiting the positioning part is provided at the opening of the groove. A positioning hole that matches the sliding part is provided at the end of the groove near the connector. A strong magnet that matches the positioning part is fixedly provided on the circumference of the positioning hole.

8. A vacuum-type automatic sprinkler fire extinguishing system based on negative pressure regulation according to claim 5, characterized in that: The balancing assembly includes a balancing plate, an L-shaped balancing frame, a support, and a thermal element. The balancing plate rests against the lower end of the sealing element via a support member. The upper end of the L-shaped balancing frame rests against one end of the balancing plate, and the other end of the L-shaped balancing frame rests against a pre-tightening screw via a steel ball. The two ends of the support rest against the balancing plate and the L-shaped balancing frame, respectively. The thermal element is located between the support and the balancing plate. The thermal element includes a base resting against the support, a placement groove on the base, a fusible alloy component placed in the placement groove, and a top column that is slidably connected to the placement groove and rests against the fusible alloy component and the support.

9. A vacuum-type automatic sprinkler fire extinguishing system based on negative pressure regulation according to claim 4, characterized in that: The vacuum unit also includes a vacuum unit PLC controller. The output terminals of the first pressure sensor, the second pressure sensor, the third pressure sensor, and the thermocouple are electrically connected to the input terminal of the vacuum unit PLC controller. The output terminal of the vacuum unit PLC controller is electrically connected to the input terminals of the suction port shut-off valve, the suction port regulating valve, the first vacuum pump, the second vacuum pump, and the water inlet pneumatic valve, respectively.

10. A vacuum-type automatic sprinkler fire extinguishing system based on negative pressure regulation according to claim 9, characterized in that: It also includes a PLC main controller, which is equipped with a timing module for the intake port shut-off valve, a timing module for the intake port regulating valve, and a pipeline leakage alarm module. The input terminal of the PLC main controller is electrically connected to the fire monitoring system, which is equipped with a fire early warning module and a fire alarm module. The output terminal of the PLC main controller is electrically connected to the vacuum pre-action alarm valve group. The vacuum unit PLC controller and the PLC main controller communicate via an RS485 interface.

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