Foam multiple and 25% drainage time field detection temperature compensation method

Abstract

The invention discloses a foam multiple and 25% drainage time on-site detection temperature compensation method, which comprises the following steps: S1, sampling different types of foam extinguishing agents, and preparing each foam extinguishing agent into a plurality of foam mixed liquids with different temperatures according to a mixing ratio; s2, respectively generating foams by the plurality of foam mixed liquids at different temperatures in the step S1, and measuring the foam multiple, 25% drainage time and the temperature of the generated foams; s3, a first fitting equation of the ratio of the foam temperature generated by the different types of foam extinguishing agents to the foam multiple is established, and a second fitting equation of the ratio of the foam temperature generated by the different types of foam extinguishing agents to the 25% drainage time is established; the foam expansion and 25% drainage time detected on site are corrected through the first fitting equation and the second fitting equation respectively. According to the method, the influence of the field environment temperature can be reduced, the foam expansion at the foam temperature of 20 DEG C and 25% drainage time standard data can be obtained on site, and the accuracy and authority of a detection result are improved.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of on-site detection of foam extinguishing agent performance, and particularly relates to a method for compensating temperature in on-site detection of foam multiple and 25% liquid separation time. BACKGROUND

[0002] In the performance of low-multiple foam extinguishing agent, foam multiple and 25% liquid separation time are two important foam performances. Foam multiple is an important index for measuring the foaming capacity of foam extinguishing agent. When the foaming capacity is too low or no foaming occurs, the foam cannot stay on the surface of the oil layer for extinguishing. 25% liquid separation time is an important index for measuring the stability of foam extinguishing agent. When the 25% liquid separation time is too short, the sprayed foam will soon become liquid separation and sink below the oil layer (generally, oil is lighter than water and floats on the water surface), and cannot stay on the surface of the oil layer for a long time to play a covering role. When the foam extinguishing agent is ineffective due to improper storage or unqualified quality, the most common problems are insufficient foaming multiple and too low 25% liquid separation time. The current on-site detection device for low-multiple foam performance mainly tests these two indexes.

[0003] Temperature change has a great influence on the test of foam multiple and 25% liquid separation time. When the temperature rises, the foam multiple increases and the 25% liquid separation time shortens. In the temperature range of 0-50℃, according to the on-site test results, it is found that the change rate of 25% liquid separation time is nearly doubled. The GB 15308 "Foam Extinguishing Agent" standard specifies the test method for foam multiple and 25% liquid separation time. The test must be carried out under the condition of ambient temperature (15-25)℃, and the temperature of the foam solution must be controlled so that the temperature of the generated foam is in the range of (15-20)℃. In order to achieve this condition, the test must be carried out in a room that can maintain this ambient temperature, and ice or hot water must be added when the foam solution is prepared to adjust the temperature. However, when the foam extinguishing agent is detected on site, it is often in the outdoor environment. In summer and winter, it is difficult to achieve this ambient temperature condition, and sometimes it is also difficult to prepare ice or hot water. Therefore, it is difficult to completely meet the test conditions. The current on-site detection device for low-multiple foam performance does not have a temperature compensation function. Therefore, the error value of the on-site test data is large, which cannot be directly compared with the data in the detection report, and brings certain inconvenience to the on-site comparison and judgment. SUMMARY

[0004] Therefore, in order to solve the problem of temperature error in the on-site detection of foam performance, the present application provides a method for compensating temperature in on-site detection of foam multiple and 25% liquid separation time, which can compensate the test data of foam multiple and 25% liquid separation time when measured on site, improve the accuracy of on-site detection of foam multiple and 25% liquid separation time of low-multiple foam extinguishing agent, and reduce the test error caused by temperature.

[0005] To achieve the above objectives, the present invention provides the following technical solution:

[0006] A method for on-site detection of foam expansion ratio and 25% separation time with temperature compensation includes the following steps:

[0007] S1: Samples of different types of foam extinguishing agents were taken, and each foam extinguishing agent was prepared into several foam mixtures at different temperatures according to its mixing ratio.

[0008] S2: In step S1, several foam mixtures at different temperatures generate foam, and the foam ratio, 25% separation time, and foam temperature are measured.

[0009] S3: Establish the first fitting equation for the ratio of foam temperature to foam expansion ratio for different types of foam extinguishing agents, and establish the second fitting equation for the ratio of foam temperature to 25% liquid outflow time for different types of foam extinguishing agents; correct the foam expansion ratio and 25% liquid outflow time detected on site using the first and second fitting equations respectively.

[0010] Furthermore, the different types of foam extinguishing agents in step S1 include one or more of protein foam extinguishing agents, fluoroprotein foam extinguishing agents, film-forming fluoroprotein foam extinguishing agents, aqueous film-forming foam extinguishing agents, alcohol-resistant foam extinguishing agents, and synthetic foam extinguishing agents.

[0011] Furthermore, in step S1, the number of foam mixtures at different temperatures is at least 10, and the temperature is 0~50℃;

[0012] Several foam mixtures at different temperatures were prepared by adding ice or hot water to each mixture.

[0013] Furthermore, in step S2, several foam mixtures at different temperatures generate foam in a standard foam generating system (a foam generating system that meets the requirements of GB 15308 "Foam Extinguishing Agents" standard).

[0014] Furthermore, in step S2, when measuring the foam ratio, 25% separation time, and foam temperature of foam mixtures at different temperatures, the baseline 25% separation time and baseline foam ratio are obtained when the foam temperature is measured to be 20°C.

[0015] Furthermore, the formula for calculating the foam expansion ratio in step S3, which is the ratio of the foam expansion ratio to the reference foam expansion ratio at different foam temperatures, is (Ⅰ).

[0016] A = P / P 20℃ (I);

[0017] A represents the foam ratio;

[0018] P represents the foaming multiple;

[0019] P 20℃ This indicates the reference foam ratio at a foam temperature of 20℃.

[0020] In step S3, the formula for calculating the ratio of 25% separation time to the baseline 25% separation time at different foaming temperatures is (II).

[0021] B=T / T 20℃ (II);

[0022] B represents a 25% precipitation time ratio;

[0023] T represents the 25% precipitation time, measured in seconds.

[0024] T 20℃ The time for 25% separation of the foam at a temperature of 20°C is expressed in seconds.

[0025] Furthermore, in step S3, the least squares method is used to establish the first fitting equation for the ratio of foam temperature to foam ratio, and the least squares method is used to establish the second fitting equation for the ratio of generated foam temperature to 25% separation time.

[0026] The first fitting equation is: A = a1t 2 +b1t+c1;

[0027] A represents the foam ratio;

[0028] a1, b1, and c1 are constants;

[0029] The second fitting equation is: B = a²t 2 +b2t+c2;

[0030] B represents a 25% precipitation time ratio;

[0031] a2, b2, and c2 are constants.

[0032] Furthermore, the correction of the foam expansion ratio and 25% separation time detected on-site using the first and second fitting equations respectively includes the following steps:

[0033] A1: Determine the type of foam extinguishing agent measured on site, and select the corresponding first and second fitting equations according to the type of foam extinguishing agent;

[0034] A2: Prepare the foam extinguishing agent to be tested into a foam mixture according to the mixing ratio. The foam mixture produces foam, and the foam expansion ratio, 25% separation time, and foam temperature are measured.

[0035] A3: The measured foam expansion ratio, 25% eluent time, and generated foam temperature obtained in step A2 are corrected using the first and second fitting equations obtained in step A1 to obtain the corrected foam expansion ratio and corrected 25% eluent time. The quality of the foam extinguishing agent is then determined based on the corrected foam expansion ratio and corrected 25% eluent time.

[0036] Furthermore, step A2 also includes preparing a foam mixture by mixing the same type of foam extinguishing agent according to the mixing ratio, using on-site water source, without temperature control, and generating foam in a standard foam generating system (a foam generating system that meets the requirements of GB 15308 "Foam Extinguishing Agents" standard);

[0037] The formula for calculating the corrected foam ratio in step A3 is (Ⅲ);

[0038] P 修= P 测 / f1(t 测 );

[0039] P 修 This is the corrected foam ratio;

[0040] P 测 The foam expansion ratio is measured in step A2;

[0041] f1(t) 测 To set the foam temperature t 测 The foam ratio obtained after substituting it into the first fitting equation;

[0042] The formula for calculating the corrected 25% precipitation time in step A3 is (Ⅳ);

[0043] T 修= T 测 / f2(t) 测 );

[0044] T 修 The corrected 25% precipitation time is expressed in seconds.

[0045] T 测 The measurement time for 25% precipitation in step S3 is expressed in seconds.

[0046] f2(t) 测 To set the foam temperature t 测 The 25% precipitation time was obtained after substituting it into the second fitting equation.

[0047] Further, in step A3, the quality of the foam extinguishing agent is judged based on the corrected foam ratio and the corrected 25% separation time. This includes ensuring that the difference between the corrected foam ratio and the characteristic foam ratio of the foam extinguishing agent is not greater than 1 or not greater than 20% of the characteristic foam ratio of the foam extinguishing agent, and that the corrected 25% separation time is not greater than 20% of the characteristic 25% separation time of the foam extinguishing agent. If these conditions are met, the product is considered qualified; otherwise, it is considered unqualified.

[0048] Compared with existing technologies, the temperature compensation method for on-site detection of foam expansion ratio and 25% eluent separation time described in this invention has the following advantages:

[0049] This invention provides a temperature compensation method for on-site testing of foam expansion ratio and 25% exudation time. First and second fitting equations are obtained through pre-calibration. When using a low-expansion foam performance on-site testing device to test foam expansion ratio and 25% exudation time, temperature compensation is applied to the test data, resulting in foam expansion ratio and 25% exudation time data corrected to a foam temperature of 20°C. This reduces the influence of ambient temperature, improves the accuracy of test results, and allows for comparison of on-site test data with test reports. This facilitates on-site quality assessment of foam extinguishing agents and provides a technical means for on-site acceptance and annual inspection of foam extinguishing agents. Attached Figure Description

[0050] The accompanying drawings, which form part of this invention, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an undue limitation of the invention. In the drawings:

[0051] Figure 1 This is a flowchart of a method for on-site detection of foam expansion and temperature compensation for 25% separation time as described in Embodiment 1 of the present invention. Detailed Implementation

[0052] It should be noted that, unless otherwise specified, the embodiments and features described in the present invention can be combined with each other.

[0053] The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0054] Example 1

[0055] A temperature compensation method for on-site detection of foam expansion ratio and 25% separation time, including a calibration stage and a measurement stage.

[0056] The steps in the calibration phase are as follows:

[0057] S1: Select different types of low-expansion foam extinguishing agents (such as aqueous film-forming agents, solvent-resistant aqueous film-forming agents, protein, fluoroprotein, synthetic foam extinguishing agents, etc.), and prepare N foam mixtures at different temperatures by adding ice or hot water according to their mixing ratio requirements.

[0058] S2: Then, foam mixtures at different temperatures are used sequentially to generate foam in a standard foam generation system. Simultaneously, the foam expansion ratio P and the 25% outflow time T are measured, along with the temperature of the generated foam. Data on the foam expansion ratio P and the 25% outflow time T at N different foam temperatures for the corresponding foam extinguishing agent type are obtained (including the foam expansion ratio P at a foam temperature of 20℃). 20℃ And 25% precipitation time data T 20℃ (as benchmark data).

[0059] S3: Calculate the ratios of foam expansion and 25% separation time to the baseline data at different foaming temperatures:

[0060] A = P / P 20℃

[0061] B=T / T 20℃

[0062] Where A represents the foam ratio, B represents the 25% separation time ratio, P represents the foam ratio, and T represents the 25% separation time. 20℃ T represents the foam ratio at a foaming temperature of 20℃. 20℃ This indicates the 25% separation time when the foam temperature is 20℃.

[0063] S4: The least squares method was used to fit the foam expansion ratio A and the 25% outflow time ratio B of different types of foam extinguishing agents at different foam temperatures. First fitting equations for the foam temperature versus foam expansion ratio and second fitting equations for the foam temperature versus 25% outflow time ratio were established for different types of foam extinguishing agents. The first fitting equation is A = f1(t), and the second fitting equation is B = f2(t), where t represents the foam temperature.

[0064] The steps in the measurement phase are as follows:

[0065] S5: First, determine the type of foam extinguishing agent being measured on site, and then select the first and second fitting equations corresponding to the foam type.

[0066] S6: Prepare the tested foam extinguishing agent into a foam mixture according to the required mixing ratio. Use on-site water as the water source; temperature control is not required. Generate foam in a standard foam generation system and measure the foam expansion ratio P. 测 and 25% precipitation time T 测 At the same time, the temperature t of the generated foam was measured. 测 .

[0067] S7: Based on foam temperature t 测 The first and second fitting equations are used to calculate the foam ratio P, corrected for a foam temperature of 20℃. 修 and 25% precipitation time T 修。

[0068] P 修= P 测 / f1(t 测 ), T 修= T 测 / f2(t) 测 )

[0069] Prepare N foam mixtures at different temperatures, with the temperature range being 0~50℃, and the number N is not less than 10.

[0070] The least squares method was used to fit the foam expansion ratio A and the 25% liquid separation time ratio B of different types of foam extinguishing agents at different foam temperatures. The expressions for the first fitting equation A=f1(t) and the second fitting equation B=f2(t) are as follows:

[0071] A=a1t 2 +b1t+c1,B=a2t 2 +b2t+c2, where a1, b1, c1, a2, b2, and c2 are constants.

[0072] Example 2

[0073] A temperature compensation method for on-site detection of foam expansion ratio and 25% separation time, including a calibration stage and a measurement stage.

[0074] The steps in the calibration phase are as follows:

[0075] S1: Select 6% aqueous film-forming foam extinguishing agent, and prepare 14 foam mixtures at different temperatures by adding ice or hot water according to its 6% mixing ratio requirement.

[0076] S2: Then, foam mixtures at different temperatures are used sequentially to generate foam in a standard foam generation system. Simultaneously, the foam expansion ratio P and the 25% outflow time T are measured, along with the temperature of the generated foam. Data on the foam expansion ratio P and the 25% outflow time T at N different foam temperatures for the corresponding foam extinguishing agent type are obtained (including the foam expansion ratio P at a foam temperature of 20℃). 20℃ And 25% precipitation time data T 20℃ (as benchmark data).

[0077] Table 1. Foam ratio and 25% separation time at different foaming temperatures

[0078] Serial number Foam solution temperature (°C) Multiple 25% liquid separation time (s) Foam temperature (°C) 1 2 7.16 175 8 2 5 7.29 169 12 3 8 7.59 175 13 4 10 7.35 172 14.5 5 13 7.62 165 17 6 15 7.16 170 18 7 16 7.43 168 19 8 18 7.61 160 20 9 20 7.63 163 21.5 10 21 7.98 156 23 11 24 7.92 150 25 12 30 8.24 140 28 13 40 8.86 130 35 14 48 9.23 123 40

[0079] S3: Calculate the ratios of foam expansion and 25% separation time to the baseline data at different foaming temperatures:

[0080] A = P / P 20℃

[0081] B=T / T 20℃

[0082] Where A represents the foam ratio, B represents the 25% separation time ratio, P represents the foam ratio, and T represents the 25% separation time. 20℃ T represents the foam ratio at a foaming temperature of 20℃. 20℃ This indicates the 25% separation time when the foam temperature is 20℃.

[0083] Table 2. Ratios of foam expansion and 25% separation time to baseline data at different foaming temperatures.

[0084] Serial number Foam temperature (°C) A B 1 8 0.9409 1.0938 2 12 0.9580 1.0563 3 13 0.9974 1.0938 4 14.5 0.9658 1.0750 5 17 1.0013 1.0313 6 18 0.9409 1.0625 7 19 0.9763 1.0500 8 20 1.0000 1.0000 9 21.5 1.0026 1.0188 10 23 1.0486 0.9750 11 25 1.0407 0.9375 12 28 1.0828 0.8750 13 35 1.1643 0.8125 14 40 1.2129 0.7688

[0085] S4: Based on the data in Table 2, the least squares method was used to perform polynomial fitting on the foam expansion ratio A and the 25% liquid separation time ratio B at 14 different foam temperatures for different types of foam extinguishing agents. The expressions for the first fitting equation A=f1(t) and the second fitting equation B=f2(t) are as follows:

[0086] A=a1t 2 +b1t+c1

[0087] B=a2t 2 +b2t+c2

[0088] Where t represents the foam temperature.

[0089] The calculated value is a1 = 2.01016 × 10 -4 b1 = -9.88172 × 10 -4 , c1=0.94132, a2=-1.46871×10 -4 b2 = -4.35 × 10 -3 Given c2 = 1.15602, the first fitting equation for the temperature-to-foam ratio of 6% aqueous film-forming foam extinguishing agent is A = 2.01016 × 10⁻⁶. -4 t 2 -9.88172×10 -4 The second fitting equation for the ratio of temperature to 25% effervescence time of 6% aqueous film-forming foam extinguishing agent is B = -1.46871 × 10⁻⁶. -4 t 2 -4.35×10 -3t+1.15602.

[0090] The steps in the measurement phase are as follows:

[0091] S5: First, determine that the type of foam extinguishing agent measured on site is 6% aqueous film-forming foam extinguishing agent, and select the first and second fitting equations obtained from the above calculation.

[0092] S6: Prepare the tested foam extinguishing agent into a foam mixture according to the required mixing ratio. Use on-site water as the water source; temperature control is not required. Generate foam in a standard foam generation system and measure the foam expansion ratio P. 测 =8.48 and 25% precipitation time T 测 At the same time, the temperature t of the generated foam was measured at 142s. 测 =30℃.

[0093] S7: Based on foam temperature t 测 =30℃, calculate the foam ratio P corrected to a foam temperature of 20℃ based on the first and second fitting equations respectively. 修 and 25% precipitation time T 修。

[0094] P 修= P 测 / f1(t 测 =7.76, T 修= T 测 / f2(t) 测 =159s.

[0095] According to the product's test report, its published characteristic values ​​are a foam expansion ratio of 8 and a 25% eluent extraction time of 180 seconds. However, under standard experimental conditions, the foam expansion ratio was measured at 7.8 and the 25% eluent extraction time at 168 seconds. According to GB 15308 "Foam Extinguishing Agents" standard, the foam expansion ratio should deviate from the characteristic value by no more than 1.0 or 20%, and the 25% eluent extraction time should deviate by no more than 20%. If the on-site measurement data (foam expansion ratio P) is used directly... 测 =8.48 and 25% precipitation time T 测 If compared to 142s, the deviation of the 25% precipitation time from the characteristic value is greater than 20%, and the result is deemed unqualified. The foam ratio P after temperature compensation... 修 and 25% precipitation time T 修 The data is very close to the data in the test report. By comparing the corrected data with the characteristic value, the standard requirements are met and the result is deemed qualified. This proves that the present invention reduces the influence of the ambient temperature on site, improves the accuracy of the test results, and enables the on-site test data to be compared with the test report, facilitating the on-site quality judgment of foam fire extinguishing agents.

[0096] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for temperature compensation of on-site detection of foam multiplication and 25% drainage time, characterized in that: The method comprises the following steps: S1: sampling different types of foam extinguishing agents, each of which is configured into several foam mixtures of different temperatures according to the mixing ratio; S2: generating foam from the several foam mixtures of different temperatures in step S1 respectively, and measuring the foam multiple, 25% drainage time and generated foam temperature; S3: establishing a first fitting equation of the generated foam temperature and foam multiple ratio of different types of foam extinguishing agents respectively, and establishing a second fitting equation of the generated foam temperature and 25% drainage time ratio of different types of foam extinguishing agents; and correcting the foam multiple and 25% drainage time detected on site respectively through the first fitting equation and the second fitting equation.

2. A method for compensating for temperature effects on the measurement of foam expansion and 25% drainage time according to claim 1, characterized in that: The different types of foam extinguishing agents in step S1 include one or more of protein foam extinguishing agent, fluoroprotein foam extinguishing agent, film-forming fluoroprotein foam extinguishing agent, water film-forming foam extinguishing agent, alcohol-resistant foam extinguishing agent and synthetic foam extinguishing agent.

3. The method of claim 1, wherein the method is temperature-compensated for foam factor and 25% drainage time in situ. The number of the several foam mixtures of different temperatures in step S1 is at least 10, and the temperature is 0-50°C; The several foam mixtures of different temperatures are prepared by adding ice blocks or hot water.

4. The method of claim 1, wherein the method is temperature-compensated for foam factor and 25% drainage time in situ. The several foam mixtures of different temperatures in step S2 are generated in a standard foam generation system.

5. The method of claim 1, wherein the method is temperature compensated. When measuring the foam multiple, 25% drainage time and generated foam temperature of the foam mixtures of different temperatures in step S2, the generated foam temperature is measured at 20°C to obtain the reference 25% drainage time and reference foam multiple.

6. A method of temperature compensation for field detection of foam expansion and 25% drainage time according to claim 5, characterized in that: The foam multiple ratio in step S3 is a calculation formula of the foam multiple ratio at different foam temperatures to the reference foam multiple, which is (I); A = P / P 20℃ (I); A is the foam multiple ratio; P is the foam multiple; P 20℃ Reference foam volume at 20°C; The 25% drainage time ratio in step S3 is a calculation formula of the 25% drainage time ratio at different foam temperatures to the reference 25% drainage time, which is (II); B = T / T 20℃ (II); B is the 25% drainage time ratio; T is the 25% drainage time, in seconds; T 20℃ represents the reference 25% drainage time of the foam at a temperature of 20°C, in s.

7. The method of claim 1, wherein the method is temperature-compensated for foam factor and 25% drainage time in situ. The first fitting equation of the foam temperature and foam multiple ratio is established by the least square method in step S3, and the second fitting equation of the generated foam temperature and 25% drainage time ratio is established by the least square method in step S3; The first fitting equation is: A = a1t 2 + b1t + c1; A is the foam multiple ratio; a1, b1 and c1 are constants; The second fitting equation is: B = a2t 2 + b2t + c2; B is the 25% drainage time ratio; a2, b2 and c2 are constants.

8. The method of claim 1, wherein the method is temperature-compensated for foam factor and 25% drainage time in situ. The correction of the foam multiple and 25% drainage time detected on site through the first fitting equation and the second fitting equation comprises the following steps: A1: determining the type of the foam extinguishing agent measured on site, and selecting the corresponding first fitting equation and second fitting equation according to the type of the foam extinguishing agent; A2: configuring the foam extinguishing agent to be measured into a foam mixture to be measured according to the mixing ratio, generating foam from the foam mixture to be measured, and measuring the foam multiple, 25% drainage time and generated foam temperature. A3: the measured foam expansion, 25% drainage time and foam generation temperature of the foam extinguishing agent obtained in step A2 are corrected using the first fitting equation and the second fitting equation obtained in step A1 to obtain a corrected foam expansion and a corrected 25% drainage time, and whether the foam extinguishing agent is qualified is determined according to the corrected foam expansion and the corrected 25% drainage time.

9. The method of claim 1, wherein the method is temperature compensated. In step A2, the same type of foam extinguishing agent to be tested is configured into a foam mixture according to a mixing ratio, and water used is a field water source, without the need of temperature control, and the foam is generated in a standard foam generation system. In step A3, the calculation formula of the corrected foam expansion is (III); P 修= P 测 / f1(t 测 ). P 修 Foam factor for the corrected foam; P 测 For step A2 measure the foam multiple; f1(t 测 ) is the foam factor ratio after bringing the foam temperature t 测 into the first fitting equation; In step A3, the calculation formula of the corrected 25% drainage time is (IV); T 修= T 测 / f2(t 测 ); T 修 T is the corrected 25% drainage time in seconds; T 测 To measure 25% liquid separation time, unit: s, for step S3 f2(t 测 ) is the 25% drainage time after the foam temperature t 测 is brought into the second fit equation.

10. The method for temperature compensation for field detection of foam expansion and 25% drainage time according to claim 1, wherein: In step A3, whether the foam extinguishing agent is qualified is determined according to the corrected foam expansion and the corrected 25% drainage time, including that the difference between the corrected foam expansion and the characteristic foam expansion of the foam extinguishing agent is not greater than 1 or not greater than 20% of the characteristic foam expansion of the foam extinguishing agent, and the corrected 25% drainage time is not greater than 20% of the characteristic 25% drainage time of the foam extinguishing agent, then the foam extinguishing agent is qualified, otherwise the foam extinguishing agent is not qualified.

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