CN205139065U - A mass loss rate test system that is used for thin water smoke experimentation of putting out a fire - Google Patents

Abstract

The utility model relates to the technical field of fire protection, in particular to a mass loss rate testing system used in the experimental process of fine water mist fire extinguishing. The test system includes: a combustion oil pan, a weighing mechanism, a fine water mist nozzle, a water collection tank, a mass sensor, a support frame and a moving mechanism; the combustion oil pan is arranged on the weighing mechanism, and Fuel is contained inside; the fine water mist nozzle is correspondingly arranged above the combustion oil pan, and the mist sprayed by the fine water mist nozzle is distributed axisymmetrically with respect to the central axis of the water collection tank; the The water collection tank is arranged on the quality sensor, and a plurality of independent collection units are arranged in the water collection tank; the quality sensor is arranged on the support frame for testing the mass of the droplets collected by each of the collection units ; The moving mechanism is used to drive the support frame to move up and down. The test system can accurately and conveniently carry out quantitative measurement on the quality of the fine water mist fire extinguishing process.

Description

Mass loss rate test system for water mist fire extinguishing experiment process

technical field

The utility model relates to the technical field of fire protection, in particular to a mass loss rate testing system used in the experimental process of fine water mist fire extinguishing.

Background technique

Heat release rate is an important factor in fire hazard analysis, and it is the most important parameter in the combustion performance of substances. Therefore, it is particularly important to measure the heat release rate. At present, there are mainly two methods to measure the heat release rate. One is the oxygen consumption method. Studies have shown that the ability to produce oxygen per unit molar mass tends to be a constant value. Based on this principle, combined with the production of CO ₂ and CO, the fuel can be calculated. The large-scale cone calorimeter only tests the heat release rate of the fuel under the action of natural wind. Moreover, many field experiments have variable wind speed conditions and do not have cone calorimeters. Therefore, more heat release rates are measured using the weighing method, that is, the heat release rate is calculated by calculating the mass loss rate of the fuel. However, in the process of fire experiments and theoretical model calculations, at the stage of the interaction between the fine water mist and the fire source, due to the interaction between the fine water mist and the fire source, the fine water mist droplets directly enter the interior of the fuel, resulting in an increase in the fuel mass , and the mass of the fuel will gradually decrease due to combustion, so it is impossible to accurately judge the reduction value of the fuel, and it is also impossible to accurately describe the mass loss rate of the fuel, so the heat release rate of the ignition source cannot be clearly defined. Some scholars directly use the heat release rate when no water mist is applied as the calculated value, which is obviously inconsistent with the actual situation. The fire extinguishing effect is of great significance.

In addition, the quantitative research on the interaction between fine water mist and smoke is less and more complicated, and the condensation between fine water mist and smoke is the focus of the research. When the fine water mist passes through the high-temperature smoke layer, a large amount of evaporation will occur due to the high temperature of the smoke layer, which reduces the flux of the fine water mist passing through the smoke layer to the flame surface. For these problems, in the experimental research of the water mist fire extinguishing process, they are either approximated or ignored, or only qualitatively described because the experimental conditions cannot be satisfied. Moreover, due to the uneven distribution of fine water mist, the flux of fine water mist in each tiny unit is also different, so quantitatively describe the flux of fine water mist passing through the smoke layer in a unit area and the fine water mist reaching the flame surface Fog flux is particularly important for the quantitative study of the interaction of fine water mist with smoke and flame.

In summary, there are the following defects in the prior art: 1. It is impossible to quantitatively describe the heat release rate of the fire source when the fine water mist interacts with the fire source; Loss distribution; 3. The mist flux distribution of fine water mist reaching different areas of the flame surface is not considered quantitatively.

Utility model content

(1) Technical problems to be solved

The technical problem to be solved by the utility model is that the prior art cannot accurately and conveniently complete quantitative research in the process of fine water mist fire extinguishing.

(2) Technical solution

In order to solve the above-mentioned technical problems, the utility model provides a mass loss rate test system for the experimental process of fine water mist fire extinguishing, which includes a combustion oil pan, a weighing mechanism, a fine water mist nozzle, a water collection tank, a mass sensor, a support frame and moving mechanism;

The combustion oil pan is arranged on the weighing mechanism, and fuel is housed in the combustion oil pan; the fine water mist nozzle is correspondingly arranged above the combustion oil pan; and the fine water mist nozzle is The sprayed mist droplets are distributed axisymmetrically with respect to the central axis of the sump; the sump is arranged on the mass sensor, and a plurality of independent collection units are arranged in the sump; the mass The sensors are arranged on the supporting frame for testing the quality of the droplets collected by each of the collecting units; the moving mechanism is used for driving the supporting frame to move up and down.

Wherein, it also includes a water collecting pipe; the water collecting pipe straddles the two sides of the burning oil pan in a semicircular shape, and an opening is provided on the water collecting pipe corresponding to a section directly above the burning oil pan for collecting falling water. When the water collecting tank moves to the bottom of the burning oil pan, the two ends of the water collecting pipe respectively connect with the water collecting tank on both sides of the burning oil pan. The collection unit is connected.

Wherein, the weighing mechanism is an electronic balance.

Wherein, the moving mechanism includes a stepping motor and a transmission assembly, and the stepping motor is connected to the support frame through a transmission assembly.

Wherein, each of the collection units is evenly distributed in the water collection tank in a grid shape.

Wherein, the fine water mist nozzle is connected to the water supply equipment through a high-pressure water inlet pipe.

The utility model also provides a test method using the above-mentioned mass loss rate test system, the test method is used to measure the mass loss of the fine water mist passing through the smoke layer, and it is characterized in that it includes the following steps:

S1. When the oil pan is controlled to burn with a fire source, a highly stable smoke layer will be formed above it after the fire source is stabilized;

S2. The moving mechanism automatically adjusts the height of the support frame according to the height of the smoke layer, so that the water collection tank is located at the lower boundary of the smoke layer;

S3. Control the fine water mist nozzle so that it sprays fine water mist according to the preset time. The fine water mist falls into the water collection tank after passing through the smoke layer, and then measures the mass of the droplets collected in the water collection tank in real time through the mass sensor. In this way, the measured value of the droplet mass entering the flame zone after vaporization and evaporation of the smoke layer is measured;

S4. Control the combustion oil pan to keep the water collecting tank at the same height as step S2 under the working condition of no fire source, and control the fine water mist nozzle to spray fine water mist according to the preset time; the mass of the mist is measured by the mass sensor Actual value: the droplet mass lost by fine water mist passing through the smoke layer is obtained after subtracting the actual value of droplet mass from the measured value of droplet mass.

The utility model also provides a test method using the above-mentioned mass loss rate test system, the test method is used to measure the mass loss rate of the fire source under the action of fine water mist, and it is characterized in that it includes the following steps:

S1', move the support frame to the bottom of the burning oil pan through the moving mechanism;

S2'. Control the fine water mist nozzle so that it sprays fine water mist according to the preset time. The fine water mist enters the water collection tanks on both sides of the combustion oil pan through the opening of the water collection pipe, and then measures the water content in the water collection tanks in real time through the mass sensor. mass of droplets collected;

S3', according to the ratio of the surface area of the water collecting pipe opening and the surface area of the burning oil pan, obtain the quality of the fine water mist droplets falling into the whole burning oil pan;

S4', calculate the mass loss value of the burning oil pan within the preset time through the weighing mechanism; after summing the mass loss value and the mass of the fine water mist droplets, divide it by the preset time to obtain the fuel in the burning oil pan rate of mass loss.

(3) Beneficial effects

The above-mentioned technical scheme of the utility model has the following beneficial effects: the utility model provides a mass loss rate testing system for the experimental process of water mist fire extinguishing, which can realize accurate and convenient completion of each parameter in the process of water mist fire extinguishing Quantitative research; quantitative real-time measurement of the mass of water mist entering the oil pool during the fire process can accurately calculate the mass loss rate of fuel to calculate the heat release rate; quantitative real-time measurement of the mist flow of fine water mist through the smoke layer Quantitatively describe the distribution of the mass loss of fine water mist through the independent mass real-time measurement of micro-units; quantitative real-time measurement of the flux distribution of fine water mist that directly interacts with the flame. The real-time monitoring of these qualities has an important guiding role in the study of the fire extinguishing mechanism of fine water mist and the quantitative study of the interaction between fine water mist and smoke.

Description of drawings

Fig. 1 is the structure schematic diagram of the mass loss rate test system used in the water mist fire extinguishing experimental process of the utility model embodiment one;

Fig. 2 is a schematic structural view of a water collection tank according to an embodiment of the present invention;

FIG. 3 is a schematic structural diagram of a mass loss rate testing system used in a water mist fire extinguishing experiment in Embodiment 2 of the present utility model.

Among them, 1: high-pressure water inlet pipe; 2: fine water mist nozzle; 3: smoke layer; 4: stepping motor; 5: water collection tank; 6: mass sensor; 7: support frame; 8: flame; 9: combustion oil 10: fuel; 11: electronic balance; 12: water collection pipe; 13: collection unit.

detailed description

The implementation of the present utility model will be further described in detail below in conjunction with the accompanying drawings and examples. The following examples are used to illustrate the utility model, but cannot be used to limit the scope of the utility model.

In the description of the present utility model, it should be noted that unless otherwise specified, the meaning of "plurality" is two or more; the terms "upper", "lower", "left", "right", " The orientation or positional relationship indicated by "inner", "outer", "front end", "rear end", "head", "tail", etc. is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the practical Novel and simplified descriptions do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operate in a specific orientation, and therefore should not be construed as limiting the utility model. In addition, the terms "first", "second", "third", etc. are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

In the description of the present utility model, it should also be noted that, unless otherwise clearly stipulated and limited, the terms "installation", "connection" and "connection" should be understood in a broad sense, for example, it can be a fixed connection or a It can be detachably connected or integrally connected; it can be mechanically connected or electrically connected; it can be directly connected or indirectly connected through an intermediary. Those of ordinary skill in the art can understand the specific meanings of the above terms in the present utility model according to specific situations.

Embodiment one

As shown in Figure 1-2, the mass loss rate test system for the water mist fire extinguishing experimental process provided by the present embodiment 1 includes a combustion oil pan 9, a weighing mechanism, a water mist nozzle 2, a water collection tank 5, Quality sensor 6, support frame 7 and moving mechanism;

Wherein, the combustion oil pan 9 is arranged on the weighing mechanism, and the fuel 10 is housed in the combustion oil pan 9, and the combustion oil pan 9 will form a height above it after the fire source is stable under the working condition of the fire source burning. Stable smoke layer 3; the fine water mist nozzle 2 is correspondingly arranged above the combustion oil pan 9, and the mist sprayed by the fine water mist nozzle 2 is distributed axisymmetrically with respect to the central axis of the sump 5; due to the fine water The mist nozzle 2 is a symmetrical nozzle with respect to the center of the circle, so the sprayed fine water mist droplets are distributed centrally, and the droplet density gradually decreases along the radial direction, and are distributed axisymmetrically on both sides of the central axis of the sump 5 . Moreover, the sump 5 is arranged on the mass sensor 6, and a plurality of independent collection units 13 are arranged in the sump 5; meanwhile, the mass sensor 6 is arranged on the support frame 7, and is used for testing collected by each collection unit 13. Droplet mass; the moving mechanism is used to drive the support frame 7 to move up and down, which can drive the water collection tank 5 to be located at the lower boundary of the smoke layer 3, and can also drive the water collection tank 5 to be located under the combustion oil pan 9.

Embodiment two

On the basis of the first embodiment above, as shown in Figure 3, the second embodiment also includes a water collecting pipe 12; A section directly above the pan 9 is provided with an opening for collecting the mist falling into the combustion oil pan 9; The collection units 13 located on both sides of the combustion oil pan 9 are connected. The design of the water collecting pipe 12 neither affects the combustion of the flame 8, but also can achieve the purpose of collecting mist.

For the convenience of weighing, preferably, the weighing mechanism is an electronic balance 11 .

In addition, the moving mechanism includes a stepping motor 4 and a transmission assembly, and the stepping motor 4 is connected to the support frame 7 through the transmission assembly. The form of the transmission component is not limited, and can be flexibly set according to practical needs.

Each collection unit 13 is evenly distributed in the water collection tank 5 in a grid shape, for example: the collection units 13 are arranged side by side in two rows at the central axis of the water collection tank 5 . Since the distribution of fine water mist droplets is axisymmetric, through the real-time measurement of the droplet mass by the mass sensor 6, the mass distribution of the entire fine water mist coverage area can be calculated according to the area ratio, and the mass of fine water mist droplets at different heights can be plotted at the same time Distribution cloud map, mass distribution cloud map lost through the smoke layer 3, mass distribution cloud map of fine water mist passing through the smoke layer 3 and entering the flame 8 area, etc.

The fine water mist nozzle 2 is connected to the water supply equipment through the high-pressure water inlet pipe 1, so as to realize the formation of fine water mist. To put it simply, the so-called "fine water mist" is a concept relative to "water spray". The so-called fine water mist is water particles produced by high-pressure water spraying using special nozzles. In NFPA750, the definition of fine water mist is: under the minimum design working pressure, on the plane 1 meter away from the nozzle, the diameter Dv0.99 of the water particles in the thickest part of the water mist is not greater than 1000μ.

Embodiment three

In this embodiment three, a method for measuring the mass loss of the fine water mist passing through the smoke layer 3 is designed according to the test system mentioned in the above embodiment, as shown in Figure 1, the test method includes the following steps:

S1. When the combustion oil pan 9 is under the condition of burning with a fire source, a highly stable smoke layer 3 will be formed above it after the fire source is stabilized;

S2. The moving mechanism automatically adjusts the height of the support frame 7 according to the height of the smoke layer 3, so that the water collection tank 5 is located at the lower boundary of the smoke layer 3;

S3. Control the fine water mist nozzle 2 so that it sprays fine water mist according to the preset time. The fine water mist falls into the water collection tank 5 after passing through the smoke layer 3, and then the quality sensor 6 measures the water collected in the water collection tank 5 in real time. The mass of the droplets, so as to measure the measured value of the mass of the droplets entering the flame zone 8 after being vaporized and evaporated in the smoke layer 3;

S4. Control the combustion oil pan 9 under the condition of no fire source combustion, the water collection tank 5 maintains the same height as step S2, and at the same time, the fine water mist nozzle 2 is also controlled to spray fine water mist according to the preset time; measured by the mass sensor 6 The actual value of the droplet mass is obtained; the actual value of the droplet mass is subtracted from the measured value of the droplet mass to obtain the droplet mass lost by the fine water mist through the smoke layer 3 .

Embodiment four

Similarly, in this embodiment four, a method for measuring the mass loss rate of the fire source under the action of fine water mist is designed according to the test system mentioned in the above-mentioned embodiment, as shown in Figure 3, the test method includes the following step:

S1', the support frame 7 is moved to the below of the burning oil pan 9 by the moving mechanism;

S2', control the fine water mist nozzle 2 to make it spray fine water mist according to the preset time, the fine water mist enters the water collection tanks 5 on both sides of the combustion oil pan 9 through the opening of the water collection pipe 12, and then passes through the mass sensor 6 in real time Measure the mass of the droplets collected in the sump 5;

S3 ', according to the ratio of the surface area of the water collecting pipe 12 openings and the surface area of the burning oil pan 9, obtain the fine water mist droplet quality falling into the whole burning oil pan 9;

S4', calculate the mass loss value of the burning oil pan 9 within the preset time through the weighing mechanism; after summing the mass loss value and the mass of the fine water mist droplets, divide it by the preset time to obtain the burning oil pan 9 The mass loss rate of the internal fuel 10.

To sum up, the utility model provides a mass loss rate testing system used in the water mist fire extinguishing experiment process, which can realize accurate and convenient quantitative research on various parameters in the water mist fire extinguishing process; quantitative real-time measurement The quality of the fine water mist entering the oil pool during the fire process can accurately calculate the mass loss rate of the fuel to calculate the heat release rate; it can quantitatively measure the mist flux of the fine water mist through the smoke layer in real time, and through the independent mass of the micro unit Real-time measurement quantitatively describes the distribution of the mass loss of fine water mist; quantitative real-time measurement of the flux distribution of fine water mist that directly interacts with the flame. The real-time monitoring of these qualities has an important guiding role in the study of the fire extinguishing mechanism of fine water mist and the quantitative study of the interaction between fine water mist and smoke.

The embodiments of the invention have been presented for purposes of illustration and description, but are not intended to be exhaustive or to limit the invention to the forms disclosed. Many modifications and changes will be apparent to those of ordinary skill in the art. The embodiment was chosen and described in order to better illustrate the principle and practical application of the invention, and to enable those of ordinary skill in the art to understand the invention and design various embodiments with various modifications suitable for particular purposes.

Claims (6)

1. A mass loss rate testing system for the water mist fire extinguishing experiment process, characterized in that it includes a combustion oil pan, a weighing mechanism, a water mist nozzle, a water collection tank, a mass sensor, a support frame and a moving mechanism; The combustion oil pan is arranged on the weighing mechanism, and fuel is housed in the combustion oil pan; the fine water mist nozzle is correspondingly arranged above the combustion oil pan, and the sprayed water mist nozzle The mist droplets are distributed axisymmetrically with respect to the central axis of the sump; the sump is arranged on the quality sensor, and a plurality of independent collection units are arranged in the sump; the quality sensor is arranged on the support The frame is used to test the quality of the droplets collected by each of the collection units; the moving mechanism is used to drive the supporting frame to move up and down. 2. The mass loss rate testing system for water mist fire extinguishing experimental process according to claim 1, characterized in that, it also includes a water collecting pipe; On the side of the water collecting pipe, an opening corresponding to the section above the burning oil pan is provided to collect the mist falling into the burning oil pan; when the water collecting tank moves to the bottom of the burning oil pan , the two ends of the water collecting pipe are respectively connected with the collecting units on the water collecting tank located on both sides of the combustion oil pan. 3. The mass loss rate testing system for water mist fire extinguishing experiment process according to claim 1, characterized in that, the weighing mechanism is an electronic balance. 4. The mass loss rate testing system for the water mist fire extinguishing experiment process according to claim 1, wherein the moving mechanism comprises a stepper motor and a transmission assembly, and the stepper motor communicates with the transmission assembly through the transmission assembly. The support frame connection. 5 . The mass loss rate test system used in the water mist fire extinguishing experiment process according to claim 1 , wherein each of the collection units is evenly distributed in the water collection tank in a grid shape. 6 . 6 . The mass loss rate test system used in the water mist fire extinguishing experiment process according to claim 1 , wherein the water mist nozzle is connected to the water supply equipment through a high-pressure water inlet pipe.