High-synergism gas extinguishing agent and preparation method thereof

Abstract

The invention relates to a high-synergism gas extinguishing agent and a preparation method thereof. The fire extinguishing agent comprises fire extinguishing components and inert gas. The fire-extinguishing component comprises a fire-extinguishing main agent and a fire-extinguishing assistant; the fire extinguishing main agent is octafluorocyclobutane, and the fire extinguishing auxiliary agent is heptafluoropropane or pentafluoroethane; wherein the fire extinguishing component comprises the following components in percentage by volume: 60-80% of a fire extinguishing main agent and 20-40% of a fire extinguishing auxiliary agent; the inert gas is nitrogen, argon or carbon dioxide. The fire extinguishing agent is high in fire extinguishing efficiency, good in fire extinguishing effect, not prone to tempering and reburning and free of environment pollution.

Description

Technical Field

[0001] The present invention relates to the field of fire extinguishing agents, in particular to a highly synergistic gas fire extinguishing agent and a preparation method thereof. Background Art

[0002] Because halon fire extinguishing agents are ozone-depleting substances, developing efficient and environmentally friendly halon alternatives for environmental reasons (to protect the ozone layer) has become a key research topic in the fire protection field. The scientific community has explored various options, but all face challenges. For example, hydrofluoroolefins (such as heptafluoropropane) have a short atmospheric survival time (ALT) and zero ozone depletion potential (ODP), but their fire extinguishing ability is weak and they react with oxygen free radicals at high temperatures to release energy, causing a brief increase in flame height during the initial stages of extinguishing. Chlorine- and bromine-containing halogenated olefins have improved fire extinguishing performance, but their ODP values ​​are not completely zero, and their increased boiling points reduce their diffusivity. Furthermore, inert gases (such as nitrogen and argon) rely on physical asphyxiation, require high concentrations, and require bulky equipment. Aerosol fire extinguishing agents pose the risk of corrosive effects on delicate equipment. These single-component fire extinguishing agents struggle to simultaneously meet the requirements of environmental protection (low ODP, low global warming potential (GWP), high fire extinguishing efficiency (low extinguishing concentration), and safety (non-corrosive, low toxicity). The current research focus has shifted to compounding technology, which is to achieve performance complementarity by mixing different fire extinguishing agents.

[0003] In recent years, research into the synergistic effects of composite fire extinguishing agents has become a key area for improving firefighting performance. Gas synergistic fire extinguishing agents utilize a scientifically formulated combination of multiple gases, combining physical asphyxiation, chemical suppression, and rapid cooling to achieve highly effective fire extinguishing. They can quickly extinguish fires and prevent re-ignition. They are environmentally friendly, leave no residue, and are non-conductive. After extinguishing a fire, the gaseous fire extinguishing agents evaporate rapidly, leaving no residue and resisting corrosion of delicate equipment or artifacts.

[0004] In the prior art, Chinese patent CN 115814325 discloses the use of heptafluoropropane and perfluorotriethylamine and other fire extinguishing agents to form a stable azeotropic mixture, which converts the gaseous fire extinguishing agent into a liquid state, significantly reducing the fire extinguishing concentration (from 7.59% to 4.23%) and improving the fire extinguishing efficiency, while also improving transportation safety. However, the disadvantage is that it relies on expensive perfluorinated compounds (such as perfluorotriethylamine and perfluorotributylamine), which poses potential environmental persistence and bioaccumulation risks, and the preparation process requires pressurization and temperature control, which makes the process complex and costly. 112190866 discloses a fire extinguishing agent composed of a mixture of hexafluoropropane and 2-BTP in a specific ratio (60-80:20-40). The synergistic effect of chemical extinguishing (2-BTP interrupts the combustion chain reaction) and physical extinguishing (hexafluoropropane cools and isolates oxygen) significantly improves fire extinguishing efficiency, and inert gas pressurization ensures atomized spraying of the liquid mixture. However, the disadvantage is that the bromine-containing 2-BTP still poses a risk of ozone layer depletion, and the high volatility of the mixture may lead to storage leakage hazards, and the long-term environmental safety is insufficient. Therefore, the above-mentioned fire extinguishing materials are difficult to meet the comprehensive requirements of new environmentally friendly fire extinguishing technologies in terms of multiple indicators such as fire extinguishing efficiency and environmental friendliness. To achieve this goal, we need to introduce new fire extinguishing additives to optimize octafluorocyclobutane fire extinguishing agents.

[0005] Heptafluoropropane (HFC-227ea) gas fire extinguishing agent is a clean gas fire extinguishing agent with the following main characteristics: wide extinguishing range, high efficiency and no re-ignition; low toxicity, under normal circumstances, no adverse effects on the human body; heptafluoropropane is non-conductive, does not contain water-based substances, and will not damage electrical equipment; it has light environmental pollution, and heptafluoropropane fire extinguishing agent has no solid or liquid residue after extinguishing the fire; the ODP value is zero and the GWP value is very low (about 0.6). Since heptafluoropropane is a fluorinated halogenated hydrocarbon, it will also produce HF gas in a high temperature environment, which reacts with oxygen free radicals at high temperature to release energy, causing the flame height to rise briefly in the early stage of fire extinguishing; pentafluoroethane (HFC-125) has a high fire extinguishing efficiency (about 8.1 to 9.4), and its molecule does not contain chlorine and bromine atoms that damage the ozone layer, and its ozone depletion potential (ODP) value is almost zero. In addition, HFC-125 itself is relatively low in toxicity, but it is difficult to transport. Summary of the Invention

[0006] To address the problems of low fire extinguishing efficiency, poor fire extinguishing effectiveness, susceptibility to flashback, and environmental friendliness in existing fire extinguishing agents, the present invention provides a highly synergistic gas fire extinguishing agent and its preparation method. This fire extinguishing agent combines octafluorocyclobutane with HFC-227ea / HFC-125 in a specific ratio. By leveraging the synergistic effect of the two substances, the fire extinguishing effectiveness of the gas fire extinguishing agent is significantly enhanced. The fire extinguishing agent of the present invention has high fire extinguishing efficiency, excellent fire extinguishing effectiveness, is resistant to flashback, and is environmentally friendly.

[0007] The technical solutions of the present invention are as follows:

[0008] A highly synergistic gas fire extinguishing agent, the hydrofluorocarbon fire extinguishing agent comprises a fire extinguishing component and an inert gas; the fire extinguishing component is a fire extinguishing main agent and a fire extinguishing auxiliary agent; the fire extinguishing main agent is octafluorocyclobutane, and the fire extinguishing auxiliary agent is heptafluoropropane or pentafluoroethane;

[0009] Among them, the fire extinguishing components are calculated by volume percentage: the fire extinguishing main agent is 60-80%, and the fire extinguishing auxiliary agent is 20-40%;

[0010] The inert gas is nitrogen, argon or carbon dioxide.

[0011] The preparation method of the highly synergistic gas fire extinguishing agent comprises the following steps:

[0012] Among them, the fire extinguishing components are calculated by volume percentage: the fire extinguishing main agent is 45-80%, and the fire extinguishing auxiliary agent is 20-55%;

[0013] The inert gas is nitrogen, argon or carbon dioxide.

[0014] The preparation method of the highly synergistic gas fire extinguishing agent comprises the following steps:

[0015] (1) According to the target ratio, adjust the flow rate of the main fire extinguishing agent and the auxiliary fire extinguishing agent and pass them into the mixing chamber.

[0016] (2) At room temperature, first fill with inert gas and pressurize to 0.20-1.2 MPa to liquefy and mix the fire extinguishing components;

[0017] (3) Continue to fill with inert gas until the pressure reaches 1.0-2.5MPa.

[0018] After encapsulating the mixed fire extinguishing agent in the same pressure vessel, nitrogen is used as the driving medium and pressurized injection is used to achieve the system's filling pressure range. The specific pressure parameters require a comprehensive assessment of the vessel's material properties, structural strength, and actual operating conditions.

[0019] The essential features of the present invention are:

[0020] Octafluorocyclobutane, a perfluorocarbon with a four-membered ring structure, is a green, environmentally friendly specialty gas characterized by stable chemical properties, excellent insulation, non-toxicity, and zero ODP. It is being used to replace banned chlorofluorocarbons. The absence of hydrogen atoms in the octafluorocyclobutane molecule can significantly reduce the production of hydrogen fluoride during fire extinguishing. Due to its highly stable ring structure and low ozone depletion potential (ODP=0), experiments have shown that its extinguishing concentrations for methane and propane fires are 7.23% and 7.40%, respectively, demonstrating its potential as a replacement for halon fire extinguishing agents.

[0021] On this basis, it is mixed with the fire extinguishing agent heptafluoropropane or pentafluoroethane, and the fire extinguishing agent composed of the two substances acts synergistically and acts on the flame at the same time, which can improve the fire extinguishing efficiency, environmental friendliness, expand the fire extinguishing range, and reduce the losses caused by the fire. The synergistic factor is introduced to demonstrate the synergistic effect of multiple fire extinguishing agents, such as the formula:

[0022]

[0023] is the gas volume fraction (i.e., fire extinguishing concentration) when extinguishing media 1 and 2 extinguish the flame alone; C1 and C2 are the corresponding mixed gas volume fractions of extinguishing media 1 and 2 when they extinguish the flame together.

[0024] The synergy factor F is used to determine whether the fire extinguishing media 1 and 2 have a synergistic effect. When F is less than 1, it means that the fire extinguishing agents have a synergistic effect. The smaller the number, the more outstanding the synergistic effect. Otherwise, there is no synergistic effect.

[0025] The beneficial effects of the present invention are:

[0026] 1. The present invention mixes hexafluoropropane and heptafluoropropane to improve and update the components of the fire extinguishing agent, thereby reducing the fire extinguishing concentration of the fire extinguishing agent through synergistic effect, improving the fire extinguishing effect, and increasing the fire extinguishing efficiency.

[0027] Octafluorocyclobutane (c-C4F8), HFC-227ea and HFC-125, specifically, effectively reduce the critical extinguishing concentration and shorten the flame suppression response time. Experiments show that by optimizing the mixing ratio of the two, the synergistic effect is significantly enhanced, showing higher fire extinguishing efficiency than single components. DETAILED DESCRIPTION

[0028] The present invention will be further described below in conjunction with specific examples, but is not limited to the contents of the specification. Unless otherwise specified, all reagents used are by weight. Unless otherwise specified, all reagents used are commercially available reagents in this area.

[0029] Example 1

[0030] A new type of clean and efficient fluorine-containing gas fire extinguishing agent composition: octafluorocyclobutane and HFC-227ea are used as a mixture, and the fire extinguishing concentration of the mixed gas at different mass ratios is tested using the standard combustion cup method. The fuel used is propane. The experimental method refers to the combustion cup method for testing the fire extinguishing concentration of gas fire extinguishing agents in Annex B of ISO14520-1-2015.

[0031] Step 1. Preliminary preparation

[0032] First, the flow rate is dynamically corrected. The flow rate of octafluorocyclobutane and the synergistic medium is calibrated using the constant volume drainage method. The calculation is based on the formula "actual flow rate = set flow rate × correction factor" (the correction factors for components A / B1 / B2 are 0.4099, 0.4436, and 0.5380, respectively) to ensure that the error in the mixed gas ratio is ≤±2%. Then, the gas cylinder inspection and assembly phase begins: automatic disassembly equipment is used to remove the valve according to the preset torque, and the qualifications of each gas cylinder are verified, with a focus on checking the integrity of the bottle thread, the absence of corrosion and deformation on the bottle body, the effectiveness of the inspection cycle, and the completeness of safety accessories (the valve sealing requires soapy water testing, and the pressure gauge indicates normal). It is also confirmed that the name and marking of the fire extinguishing agent are consistent and the nominal pressure meets the standard.

[0033] Step 2: Set the flow rate of component A (octafluorocyclobutane):

[0034] Set the octafluorocyclobutane gas flow rate to 5.2 L min -1 , then open the air valve to exhaust the air in the tube, and then connect the connector to the mixing chamber.

[0035] Step 3: Set the flow rate of component B1 (heptafluoropropane)

[0036] Set the octafluorocyclobutane gas flow rate to 2.0 L min -1 , then open the air valve to exhaust the air in the tube, and then connect the connector to the mixing chamber.

[0037] Step 4: Mix the components

[0038] At the set flow rate, the two components are introduced into the mixing chamber, thoroughly mixed, and the cylinder is filled. Nitrogen is then added for pressurization. At room temperature, the mixture of component A, octafluorocyclobutane, and component B, heptafluoropropane, liquefies at 0.21 MPa. Using nitrogen as the driving medium, the system continues to pressurize until it reaches a filling pressure of 1.5 MPa through pressurized injection. The specific pressure parameters require a comprehensive assessment of the container's material properties, structural strength, and actual operating conditions.

[0039] In the present invention, component A actually accounts for 70.61% and component B1 actually accounts for 29.39%. After the combustion cup (full name: cup burner) fire extinguishing experiment, the average fire extinguishing concentration tested was 7.02% (extinguishing propane fire), which is significantly reduced compared with the theoretical fire extinguishing concentration of 7.61% without synergy. The synergy factor is 0.9225, and it has full submersion characteristics and good anti-reignition ability.

[0040] Examples 2-6

[0041] The other steps of Examples 2-6 are the same as those of Example 1, except that the flow rates of A and B1 are adjusted to change the components and the number of portions. For specific adjustments, please refer to Table 1 below.

[0042] Table 1 Distribution ratio of A and B1 components in Examples 2-6

[0043]

[0044] When the proportion of component A reaches 70.61%, the synergistic effect is the best.

[0045] After the combustion cup (full name: cup burner) fire extinguishing test of Example 2, the fire extinguishing concentration was tested to be 7.40% and the synergy factor was 1.0000 (extinguishing propane fire)

[0046] After the combustion cup (full name: cup burner) fire extinguishing test of Example 3, the fire extinguishing concentration was tested to be 8.15%, and the synergy factor was 1.0000 (extinguishing propane fire)

[0047] After the combustion cup (full name: cup burner) fire extinguishing test of Example 4, the fire extinguishing concentration was tested to be 7.75%, and the synergy factor was 0.9704 (extinguishing propane fire)

[0048] After the combustion cup (full name: cup burner) fire extinguishing test of Example 5, the fire extinguishing concentration was tested to be 7.60%, and the synergy factor was 0.9609 (extinguishing propane fire)

[0049] After the combustion cup (full name: cup burner) fire extinguishing test of Example 6, the fire extinguishing concentration was tested to be 7.49%, and the synergy factor was 0.9656 (extinguishing propane fire)

[0050] Examples 7-11

[0051] The other steps of Example 7 are the same as those of Example 1, except that component B1 heptafluoropropane is replaced by component B2 pentafluoroethane, and the composition (flow rate) of components A1 and B2 is adjusted, and step 3 is adjusted.

[0052] In step 3, under room temperature conditions, the mixed gas of component A, octafluorocyclobutane, and component B2, pentafluoroethane, heptafluoropropane, is liquefied at 1.2 MPa, and then nitrogen is added and the pressure is continued to be increased to 2.2 MPa.

[0053] Example 7. In the present invention, component A actually accounts for 45.57% and component B2 actually accounts for 54.43%. After the combustion cup (full name: cup burner) fire extinguishing experiment, the average fire extinguishing concentration tested was 8.25% (extinguishing propane fire), which is significantly reduced compared with the theoretical fire extinguishing concentration of 8.63% without synergy. The synergy factor is 0.9558, and it has full submersion characteristics and good anti-reignition ability.

[0054] After the combustion cup of Example 7, the fire extinguishing test of the combustion cup (full name: cup burner) was carried out, and the fire extinguishing concentration was tested to be 8.25%, and the theoretical concentration was 8.64% (to extinguish propane fire).

[0055] Please see Table 2 below for detailed adjustments.

[0056] The other steps of Examples 8-11 are the same as those of Example 7, except that the flow rates of A and B2 are adjusted to adjust the components and the number of portions. For specific adjustments, please refer to Table 2 below.

[0057] Examples 8-11

[0058] Table 2 Distribution ratio of A and B2 components in Examples 8-11

[0059]

[0060] When the proportion of component A reaches 45.57%, the synergistic effect is better.

[0061] After the combustion cup of Example 8, the fire extinguishing test of the combustion cup (full name: cup burner) was carried out, and the fire extinguishing concentration was tested to be 10.03%, and the synergy factor was 1.0000 (extinguishing propane fire)

[0062] After the combustion cup (full name: cup burner) fire extinguishing test of Example 9, the fire extinguishing concentration was tested to be 10.15%, and the synergy factor was 1.0770 (extinguishing propane fire)

[0063] After the combustion cup of Example 10, the fire extinguishing test of the combustion cup (full name: cup burner) was carried out, and the fire extinguishing concentration was tested to be 9.66%, and the synergy factor was 1.0610 (extinguishing propane fire)

[0064] After the combustion cup (full name: cup burner) fire extinguishing test of Example 11, the fire extinguishing concentration was tested to be 7.80%, and the synergy factor was 0.9648 (extinguishing propane fire)

[0065] Matters not covered by the present invention are known technologies.

Claims

1. A highly synergistic gas fire extinguishing agent, characterized by: The fire extinguishing agent includes a fire extinguishing component and an inert gas; the fire extinguishing component is a fire extinguishing main agent and a fire extinguishing auxiliary agent; the fire extinguishing main agent is octafluorocyclobutane, and the fire extinguishing auxiliary agent is heptafluoropropane or pentafluoroethane; The fire extinguishing components are as follows: the fire extinguishing main agent is 45-80% and the fire extinguishing auxiliary agent is 20-55%.

2. The highly synergistic gas fire extinguishing agent according to claim 1, characterized in that: The inert gas is nitrogen, argon or carbon dioxide.

3. The method for preparing a highly synergistic gas fire extinguishing agent according to claim 1, wherein: The steps include: (1) According to the target ratio, adjust the flow rate of the main fire extinguishing agent and the auxiliary fire extinguishing agent and introduce them into the mixing chamber; (2) At room temperature, first fill with inert gas and pressurize to 0.20-1.2 MPa to liquefy and mix the fire extinguishing components; (3) Fill with inert gas to a pressure of 1.0-2.5 MPa.

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