Radial total-flooding atomizing nozzle for perfluorohexanone fire extinguishing system

Abstract

The invention belongs to nozzles, and particularly relates to a radial total-flooding atomizing nozzle for a perfluorohexanone fire extinguishing system. The radial total-flooding atomizing nozzle for the perfluorohexanone fire extinguishing system comprises a nozzle body and an atomizing body, the nozzle body is arranged above the atomizing body, the lower half part of the nozzle body is sleeved outside the atomizing body, and the nozzle body is in interference fit with the atomizing body. The reducing atomizing nozzle has the remarkable effects that the reducing atomizing nozzle special for total flooding fire extinguishing of a perfluorohexone fire extinguishing system is short in spraying time (8-10 s) and large in flow, efficient gasification and total flooding fire extinguishing effects of a perfluorohexone fire extinguishing agent are achieved, and solid surface fire disasters, liquid fire disasters, gas fire disasters capable of cutting off a gas source before fire extinguishing and electrical fire disasters can be extinguished.

Description

Technical Field

[0001] This invention pertains to nozzles, specifically to a radial total flooding atomizing nozzle for a perfluorohexanone fire extinguishing system. Background Technology

[0002] In 2016, at the 28th Conference of the Parties to the Montreal Protocol held in Kigali, Rwanda, nearly 200 countries reached a historic agreement by consensus to limit the use of hydrofluorocarbons (HFCs), and my country will also gradually freeze the use of HFCs starting in 2024. Heptafluoropropane fire extinguishing agents currently in use are HFCs, and their use will be gradually frozen starting in 2024.

[0003] Perfluorohexanone (PFH) fire extinguishing agent has an ozone depletion potential (OPD) of 0 and an atmospheric residual time of only 3-5 days. Its usage concentration is less than 10% of the no-toxicity-effect level (NOAEL), and its fire extinguishing design concentration is 6.5% to 8%. It can extinguish solid surface fires, liquid fires, gas fires where the gas supply can be cut off before extinguishing, and electrical fires. It features high fire extinguishing efficiency and environmental safety, and can be applied to computer rooms, communication equipment rooms, electronic equipment rooms, data storage rooms, control rooms, power distribution rooms, generator rooms, libraries, archives, and museums in telecommunications, power, nuclear power, transportation, finance, government, and enterprise sectors. It is one of the best alternatives to heptafluoropropane fire extinguishing agents.

[0004] Perfluorohexanone extinguishing agent is liquid at room temperature and pressure, and does not automatically diffuse and penetrate like other gaseous extinguishing agents. In total flooding systems, how to make the very limited extinguishing agent quickly vaporize and penetrate into the interior of the protected object (such as the internal space of cabinets and electrical equipment) is a problem that must be addressed.

[0005] Existing fire extinguishing nozzles in the fire protection field are generally designed for water or gas extinguishing agents, such as water sprinklers and ordinary gas nozzles. They cannot vaporize liquid extinguishing agents. In addition, water mist nozzles spray in a cone shape, which is not suitable for total flooding fire protection. Ultra-fine water mist nozzles have too small a flow rate. None of the aforementioned nozzles are suitable for total flooding perfluoroacetone fire extinguishing systems. Summary of the Invention

[0006] To address the shortcomings of existing technologies, this invention provides a radial total flooding atomizing nozzle for perfluorohexanone fire extinguishing systems.

[0007] The present invention is implemented as follows: a radial total flooding atomizing nozzle for a perfluorohexanone fire extinguishing system, comprising a nozzle body and an atomizing body, wherein the nozzle body is disposed above the atomizing body, and the lower half of the nozzle body is sleeved on the atomizing body, and the nozzle body and the atomizing body are interference fit.

[0008] As described above, a radial total flooding atomizing nozzle for a perfluorohexane fire extinguishing system has a hollow cylindrical structure. The top of the nozzle body is provided with an octagonal tooth-shaped outer sidewall. Several nozzle holes are provided on the cylindrical sidewall of the nozzle body. The nozzle holes are arranged radially and are at 90° to the nozzle body inlet.

[0009] As described above, a radial total flooding atomizing nozzle for a perfluorohexane fire extinguishing system has a flared nozzle orifice with the flared opening facing the nozzle body.

[0010] As described above, a radial total flooding atomizing nozzle for a perfluorohexane fire extinguishing system has two rows of nozzle holes, with each row containing 4-12 nozzle holes. The two rows of nozzle holes have different diameters, with the larger diameter nozzle holes located closer to the bottom and the smaller diameter nozzle holes located closer to the top.

[0011] The radial total flooding atomizing nozzle for a perfluorohexane fire extinguishing system as described above, wherein the preferred number of nozzle holes per row is 8, and they are evenly arranged circumferentially.

[0012] As described above, a radial total flooding atomizing nozzle for a perfluorohexanone fire extinguishing system includes an atomizing body that is a cylindrical part with a diameter matching the inner wall size of the nozzle body. The outer wall of the atomizing body is provided with a spiral groove, and atomizing holes that penetrate vertically are provided on the atomizing body.

[0013] The radial total flooding atomizing nozzle for a perfluorohexane fire extinguishing system, as described above, has 16 spiral grooves evenly arranged circumferentially along the atomizing body.

[0014] The radial total flooding atomizing nozzle for a perfluorohexanone fire extinguishing system, as described above, wherein the number of atomizing holes ranges from 10 to 40 and is uniformly arranged along the atomizing body.

[0015] The significant advantages of this invention are: It utilizes a specialized radial atomizing nozzle for total flooding fire suppression in perfluorohexanone (PFH) fire extinguishing systems. This nozzle features a short discharge time (8-10 seconds) and a large flow rate, achieving highly efficient vaporization of PPH extinguishing agent and a total flooding extinguishing effect. It can extinguish solid surface fires, liquid fires, gas fires where the gas supply can be cut off before extinguishing, and electrical fires. It is widely used in computer rooms, communication equipment rooms, electronic equipment rooms, data storage rooms, control rooms, power distribution rooms, generator rooms, libraries, archives, and museums in telecommunications, power, nuclear power, transportation, finance, government, and enterprise sectors. Attached Figure Description

[0016] Figure 1a A schematic diagram of a radial total flooding atomizing nozzle for a perfluorohexanone fire extinguishing system;

[0017] Figure 1b yes Figure 1aA schematic diagram of the AA-direction cross-section structure;

[0018] Figure 1c yes Figure 1a Top view;

[0019] Figure 2a Schematic diagram of the nozzle body;

[0020] Figure 2b yes Figure 2a A schematic diagram of the AA-direction cross-section structure;

[0021] Figure 2c yes Figure 2a Top view;

[0022] Figure 2d yes Figure 2a A three-dimensional image;

[0023] Figure 3. Schematic diagram of the atomizing body;

[0024] Figure 3b yes Figure 3a A schematic diagram of the AA-direction cross-section structure;

[0025] Figure 3c yes Figure 3a Top view;

[0026] Figure 3d yes Figure 3a A three-dimensional image.

[0027] In the diagram: 1. Nozzle body, 2. Atomizing body.

[0028] Table 1. Preferred Nozzle Sizes (Unit: mm) -- Corresponding Figure 2a

[0029]

[0030]

[0031] Table 2 Preferred Nozzle Body Dimensions (Unit: mm) -- Corresponding Figure 2c

[0032] Nominal diameter L1 L2 L3 L4 ΦD3 ΦD4 DN32 12 30 38 52 38 37 DN40 13 32 38 54 44 43 DN50 14 34 44 61 55 54

[0033] Table 3. Optimal Atomizer Size Table (Unit: mm) -- Corresponding Figure 3d

[0034] Detailed Implementation

[0035] A radial total flooding atomizing nozzle for a perfluorohexane fire extinguishing system includes a nozzle body 1 and an atomizing body 2. The atomizing body 2 has several spiral grooves with appropriate angles and widths on its side and multiple atomizing holes on its body, and is interference-fitted into the nozzle body 1. The nozzle body 1 is provided with upper and lower rows of nozzle holes, with 8 nozzle holes in each row. The nozzle holes are radially arranged and are at 90° to the nozzle body inlet.

[0036] When the fire extinguishing system is activated, the perfluorohexanone extinguishing agent in the extinguishing agent cylinder group flows rapidly into the perfluorohexanone radial total flood nozzle in liquid form under the pressure of the gas cylinder. When the extinguishing agent flows through the atomizer 2, under the combined action of high pressure, high speed and the special structure of the atomizing component, it collides with the nozzle body 1 at high speed. Through centrifugal force, impact and other effects, a large amount of atomized liquid extinguishing agent is formed. Then, it passes through the trumpet-shaped nozzle orifice (preferably a 90° trumpet-shaped nozzle orifice) of the nozzle body 1 and comes into contact with the stationary air in the protected area. Due to relative motion, under the action of aerodynamics, the extinguishing agent enters the protected area in a completely vaporized state, thereby achieving the most efficient fire extinguishing effect.

[0037] The nozzle body 1 adopts a Whitworth pipe thread Rc with a tooth angle of 55°.

[0038] The nozzle body 1 has three diameters: DN32, DN40, and DN50.

[0039] The nozzle body 1, depending on the different nominal diameters, has n-φD1 horn-shaped spray holes at L1 on the side cylinder, which are used to spray perfluorohexanone extinguishing agent into the area below the nozzle to protect the extinguishing effect of this part of the area.

[0040] The nozzle body 1 has n-φD2 small horn-shaped spray holes at L2 on the side cylinder to ensure that the perfluorohexanone extinguishing agent is sprayed to the height of the nozzle, thus protecting the extinguishing effect of this part of the area.

[0041] The nozzle body 1, n-φD1 and n-φD2 nozzle orifice dimensions are determined according to Table 2 of GB25972-2010 and verified by experiments to ensure that perfluorohexanone, after being sprayed from this nozzle, can flood all space within the protection radius.

[0042] Nozzle designation and equivalent orifice size (excerpted from Table 2 of GB25972-2010, unit: mm)

[0043]

[0044]

[0045] In fire extinguishing system engineering applications, the nozzle's working pressure is calculated using the following formula:

[0046]

[0047] In the formula

[0048] P c — Nozzle working pressure (MPa, absolute pressure)

[0049]

[0050]

[0051] In the formula:

[0052] P m —Pressure inside the storage container at a point in the process (MPa, absolute pressure);

[0053] P0 – Pressurization pressure (MPa, absolute pressure) of the perfluorohexanone fire extinguishing agent storage container;

[0054] V0 – Total gas volume in all storage containers before discharge (m³) 3 );

[0055] σ—Liquid density of perfluorohexanone fire extinguishing agent (kg / m³) 3 At 20℃, it is 1616 kg / m³. 3 W – Protection, design dosage (kg) of perfluorohexanone fire extinguishing agent for fire extinguishing or inerting in the protected area;

[0056] V p —The internal volume of the pipeline network (m³) 3 );

[0057] n — the number of storage containers;

[0058] V b —Capacity of the storage container (m³) 3 );

[0059] η — Filling volume (kg / m3).

[0060] —Total system process resistance loss (MPa)

[0061]

[0062] δP — Calculates the resistance loss of the pipe section (MPa);

[0063] L—Calculated pipe length (m), which is the sum of the friction length and the equivalent length of local losses in the calculated pipe segment;

[0064] Q—Pipe design flow rate (kg / s);

[0065] D – Pipe inner diameter (mm).

[0066] P h —Elevation pressure (MPa)

[0067] P h =10 -6 ·σHg

[0068] In the formula:

[0069] H – The height difference (m) of the nozzle relative to the liquid level in the storage container at the process point;

[0070] σ—Liquid density of perfluorohexanone fire extinguishing agent (kg / m³) 3 At 20℃, it is 1616 kg / m³. 3 ;

[0071] g — acceleration due to gravity (m / s²) 2 ).

[0072] The equivalent orifice area of ​​the nozzle should be calculated using the following formula:

[0073]

[0074] In the formula

[0075] F c —Equivalent orifice area of ​​the nozzle (cm²) 2 )

[0076] q c --Equivalent orifice unit area spray rate [(kg / s) / cm] 2 [This should be adopted according to design specifications.]

[0077] The nozzle body 1 has a φD3 stepped hole, machined to L4, for interference fit installation with the atomizing body 2 to prevent the atomizing body from moving.

[0078] The atomizing body 2 has three pipe diameters: DN32, DN40, and DN50.

[0079] The atomizing body 2 has a number of spiral grooves of varying width W and depth L on its side, depending on the nominal diameter, and a number of vaporization holes n-φD on its body. Under the combined action of high pressure, high speed, centrifugation, and impact, the perfluorohexanone fire extinguishing agent is atomized and vaporized.

[0080] This invention relates to a radial total flooding atomizing nozzle for a perfluorohexane fire extinguishing system. After development, the nozzle's spray characteristics were tested according to section 5.6.9 of GB25972-2010 "Gaseous Fire Extinguishing Systems and Components," and the test was conducted at a depth of 100m. 3In the fire extinguishing test chamber, an extinguishing test for Class A firewood was conducted according to Appendix C of GB25972-2010. The specific test details are as follows:

[0081] 3.1 Experimental Space

[0082] The laboratory is 4.7m long and wide, 4.5m high, and has a volume of approximately 100m³. 3 .

[0083] 3.2 Nozzle Arrangement

[0084] The nozzle should be positioned so that the extinguishing agent is not sprayed directly onto the test fire and does not cause fuel splashing.

[0085] 3.3 Test of jet characteristics of fully submerged nozzle

[0086] (1) Requirements for perfluorohexanone fire extinguishing systems

[0087] Fire suppression systems should meet the following requirements

[0088] a) Extinguishing agent cylinders should be placed at the lowest operating temperature for at least 16 hours;

[0089] b) The piping layout should ensure that the minimum nozzle pressure is generated at the nozzle (when the temperature is +20℃ to +22℃).

[0090] c) The extinguishing agent discharge rate is calculated based on the actual test space and 76.92% of the minimum design concentration at +20℃. If there is an actual leak in the test space and the residual discharge rate of the extinguishing agent cylinder group is not zero, the extinguishing agent filling rate should be appropriately corrected.

[0091] d) Extinguishing agent release time: 8s to 10s for perfluorohexanone extinguishing systems.

[0092] (2) Fuel requirements

[0093] The fuel is n-heptane, and its fraction is:

[0094] — Initial boiling point: +90℃;

[0095] —50%: +93℃;

[0096] —Dry point: +96.5℃

[0097] —Density (+15.6℃): 0.700 kg / m³ 3 ±50kg / m³.

[0098] —Reid vapor pressure: 13.79 kPa. 1)

[0099] (3) Nozzle pressure measurement

[0100] During the system's discharge process, the pressure of the nozzle should be measured by a pressure sensor on the pipeline. The pressure sensor should be no more than 1m away from the nozzle, and the sensor's accuracy should be no less than 0.5%.

[0101] (4) Fuel tank

[0102] The fuel tank is a steel cylinder with an inner diameter of 77mm, a height of 100mm, a wall thickness of 6mm, a n-heptane depth of at least 50mm, and a liquid level at least 40mm from the tank opening.

[0103] A baffle of the same height as the test space was set up in the test space. The baffle was located at 1 / 2 distance from the center of the space and one corner of the wall, and the baffle was 940mm wide.

[0104] There are a total of 9 fuel canisters. Eight of them are placed diagonally against the four walls of the test space, staggered four times. The bottom corner fuel canister is placed on the ground, 50mm from the wall. The top corner fuel canister is 300mm from the top and 50mm from the wall. The remaining fuel canister is placed on the ground behind a baffle.

[0105] (5) Experiment

[0106] Ignite the fuel canister, pre-ignite for 30 seconds, then start the system.

[0107] (6) Measured results

[0108] The extinguishing concentration is 4.5%, using one nozzle. The system spray time is 9.8 seconds, the maximum time from extinguishing agent release to flame extinguishment is 10.6 seconds, and the extinguishing time of the fuel tank behind the baffle is 7.5 seconds. There is no splashing. The pressure in front of the nozzle is 1.0 MPa.

[0109] 3.4 Class A Timber Pile Fire Extinguishing Test

[0110] (1) The wood used is spruce, fir or pine of similar density, with a moisture content of 9% to 13%.

[0111] The timber stack consists of four layers, with six square timbers in each layer. The square timbers have a cross-section of 40mm × 40mm and a length of 450mm ± 50mm. The layers of timber stack are placed at right angles and staggered, with the timbers in each layer evenly spaced to form a square. The timbers and the layers are then nailed together to form the timber stack.

[0112] The oil pan is a square steel plate with an area of ​​0.25m². 2 It is 106mm high.

[0113] The woodpile was placed in the center of the laboratory, with its bottom 600mm from the ground.

[0114] n-Heptane is used as fuel to ignite the timber stacks.

[0115] Place the timber stack on a steel test frame, with the oil pan positioned directly below the stack, its upper edge approximately 300mm from the bottom of the stack. The test frame should be designed to fully expose the timber stack to the atmosphere.

[0116] (2) Test Procedure

[0117] Ignite the woodpile outside the test space, but avoid exposure to sunlight, rain, snow, or other weather conditions. The wind speed should not exceed 3 m / s, and appropriate wind protection measures should be taken if necessary. If igniting the woodpile indoors, the indoor space volume should be greater than 6 times the test space volume. Inject 1.6 L of n-heptane into the oil pan, ignite it, and allow the woodpile to burn freely for 3 minutes. After the n-heptane is exhausted, the woodpile should continue to burn for 3 minutes.

[0118] The total pre-ignition time outside the test space was: After pre-combustion, move the woodpile into the test space. The time from moving the woodpile into the test space to activating the fire suppression system should not exceed 15 seconds. Close all openings in the test space and manually activate the fire suppression system.

[0119] After the extinguishing agent was sprayed, the test space was kept sealed for a 10-minute immersion period. After 10 minutes, the woodpile was removed from the test space to observe whether it reignited.

[0120] (3) Measured results

[0121] The extinguishing agent was released in 9 seconds, with a total release volume of 88 kg into the test space. The open flame was extinguished within 60 seconds of release. The test space was then sealed for a 10-minute immersion period. No embers were observed during this period, and no reignition was observed. After the 10-minute immersion period, the woodpile was removed from the test space, and no reignition occurred.

[0122] Through spray characteristic tests of the total flood nozzle and extinguishing tests of Class A firewood fires, it was verified that the radial total flood atomizing nozzle used in the perfluorohexanone fire extinguishing system is suitable for extinguishing Class A and Class B fires using the total flood method in the perfluorohexanone fire extinguishing system.

Claims

1. A radial total flooding atomizing nozzle for a perfluorohexanone fire extinguishing system, characterized in that: It includes a nozzle body (1) and an atomizing body (2), wherein the nozzle body (1) is positioned above the atomizing body (2), and the lower half of the nozzle body (1) is fitted over the atomizing body (2), and the nozzle body (1) and the atomizing body (2) are interference-fitted.

2. The radial total flooding atomizing nozzle for a perfluorohexanone fire extinguishing system as described in claim 1, characterized in that: The nozzle body (1) is a hollow cylindrical structure. The top of the nozzle body (1) is provided with an octagonal tooth-shaped outer sidewall. Several nozzle holes are provided on the cylindrical sidewall of the nozzle body (1). The nozzle holes are arranged radially and are 90° to the inlet of the nozzle body (1).

3. The radial total flooding atomizing nozzle for a perfluorohexanone fire extinguishing system as described in claim 2, characterized in that: The nozzle orifice is horn-shaped, with the horn opening facing outwards from the nozzle body (1).

4. The radial total flooding atomizing nozzle for a perfluorohexanone fire extinguishing system as described in claim 3, characterized in that: The nozzle holes are arranged in two rows, with 4-12 nozzle holes in each row. The two rows of nozzle holes have different diameters. The nozzle holes with larger diameters are located closer to the bottom, while the nozzle holes with smaller diameters are located closer to the top.

5. A radial total flooding atomizing nozzle for a perfluorohexanone fire extinguishing system as described in claim 4, characterized in that: The preferred number of nozzle holes per row is 8, evenly arranged circumferentially.

6. The radial total flooding atomizing nozzle for a perfluorohexanone fire extinguishing system as described in claim 5, characterized in that: The atomizing body (2) is a cylindrical part. The diameter of the atomizing body (2) matches the inner wall size of the nozzle body (1). The outer wall of the atomizing body (2) is provided with a spiral groove, and the atomizing hole that runs through the upper and lower parts is provided on the atomizing body (2).

7. A radial total flooding atomizing nozzle for a perfluorohexanone fire extinguishing system as described in claim 6, characterized in that: A total of 16 spiral grooves are evenly arranged along the circumference of the atomizing body (2).

8. A radial total flooding atomizing nozzle for a perfluorohexanone fire extinguishing system as described in claim 7, characterized in that: The number of atomizing holes ranges from 10 to 40, and they are evenly distributed along the atomizing body (2).

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