Multi-channel fire extinguishing agent concentration measuring device

Abstract

A multi-channel fire extinguishing agent concentration measuring device (100) not only can sample fire extinguishing agent gas through multiple channels, but also can avoid the situation that the number of parts needed for measurement is increased, and measurement operation becomes complex. The multi-channel fire extinguishing agent concentration measuring device comprises a gas concentration analysis unit (20), and the gas concentration analysis unit (20) comprises a plurality of gas channels connected with outlets of a plurality of sampling pipes (200); the gas suction unit (30) is connected to an outlet of the gas concentration analysis unit and used for sucking and discharging gas in the gas concentration analysis unit, and a plurality of gas channels of the gas concentration analysis unit sample the detected gas through a plurality of sampling pipes respectively.

Description

Technical Field

[0001] The present invention relates to a multi-channel fire extinguishing agent concentration measuring device, and particularly to a fire extinguishing agent concentration measuring device for measuring the volume concentration of fire extinguishing agents at multiple measurement points in an aircraft during a flight test. Background Art

[0002] In the past, a single-channel fire extinguishing agent concentration measuring device used in civil aircraft included: a gas concentration analysis unit, a gas suction unit, and a temperature control chassis. The gas concentration analysis unit was formed with only one gas channel. When the single-channel gas fire extinguishing agent concentration measuring device configured as described above was operating, a sampling tube was connected to the above-mentioned one gas channel to form one channel of the fire extinguishing agent concentration measuring device. The above-mentioned single-channel fire extinguishing agent concentration measuring device could only sample the measured gas at one measurement point and measure its concentration. In the case where there were many measurement points in an aircraft and it was necessary to synchronously sample the measured gas through multiple channels, usually, single-channel synchronous sampling of multiple fire extinguishing agent concentration measuring devices was used in the past. Thus, the number of components required for measurement increased, and the measurement operation became complicated. Summary of the Invention

[0003] The present invention has been completed in view of the above technical problems, and its purpose is to provide a multi-channel fire extinguishing agent concentration measuring device that can sample fire extinguishing agent gas through multiple channels and avoid an increase in the number of components required for measurement and complication of the measurement operation.

[0004] To achieve the above object, a first aspect of the present invention provides a multi-channel fire extinguishing agent concentration measuring device, including: a gas concentration analysis unit, the gas concentration analysis unit including a plurality of gas channels connected to the outlets of a plurality of the sampling tubes; and a gas suction unit, the gas suction unit being connected to the outlet of the gas concentration analysis unit, sucking the gas therein and discharging it, and the plurality of gas channels of the gas concentration analysis unit respectively sampling the measured gas through a plurality of sampling tubes.

[0005] According to the above structure, since the plurality of gas channels of the gas concentration analysis unit respectively sample the measured gas through a plurality of sampling tubes, it is possible to simultaneously sample the gas at multiple measurement points without a plurality of single-channel fire extinguishing agent measuring devices, which can reduce the number of components and simplify the measurement operation.

[0006] In addition, the multi-channel fire extinguishing agent concentration measuring device according to a second aspect of the present invention is based on the multi-channel fire extinguishing agent concentration measuring device according to the first aspect of the present invention, and further includes a sampling tube cleaning unit, the sampling tube cleaning unit including: a cleaning pipeline, the cleaning pipeline branching out a first cleaning gas path and a second cleaning gas path at the inlet, and the outlet end being connected to the sampling tube; and a first gas path switching unit, the first gas path switching unit switching between the first cleaning gas path and the second cleaning gas path.

[0007] According to the above structure, since a sampling tube cleaning unit is further included, compared with the prior art, the sampling tube can be cleaned before sucking the gas to be measured by the sampling tube, avoiding the influence of impurities originally existing in the sampling tube on the subsequent measurement of the concentration of the gas to be measured.

[0008] In addition, according to the above structure, since the cleaning pipeline branches out a first cleaning gas path and a second cleaning gas path at the outlet and can be switched between the first cleaning gas path and the second cleaning gas path through the first gas path switching unit, the switching between the cleaning gas paths can be quickly switched, simplifying the operation.

[0009] In addition, the multi-channel fire extinguishing agent concentration measuring device according to the third aspect of the present invention is based on the multi-channel fire extinguishing agent concentration measuring device according to the first aspect of the present invention, and further includes a second gas path switching unit, which is arranged at the outlet and switches between the sampling gas path connecting the sampling tube and the gas concentration analysis unit and the cleaning gas path connecting the sampling tube cleaning unit and the sampling tube.

[0010] According to the above structure, since it can be switched between the sampling gas path connecting the sampling tube and the gas concentration analysis unit and the cleaning gas path connecting the sampling tube cleaning unit and the sampling tube through the second gas path switching unit, the sampling gas path and the cleaning gas path can be quickly switched, simplifying the operation.

[0011] In addition, the multi-channel fire extinguishing agent concentration measuring device according to the fourth aspect of the present invention is based on the multi-channel fire extinguishing agent concentration measuring device according to the second or third aspect of the present invention. The first cleaning gas path and the second cleaning gas path of the cleaning pipeline share a set of pipelines, and the first gas path switching unit and the second gas path switching unit adopt three-way switching valves.

[0012] According to the above structure, since the first cleaning gas path and the second cleaning gas path of the cleaning pipeline share a set of pipelines, and the first gas path switching unit and the second gas path switching unit adopt three-way switching valves, the quick switching between the cleaning gas paths and the quick switching between the sampling gas path and the cleaning gas path can be realized through a simple structure.

[0013] In addition, the multi-channel fire extinguishing agent concentration measuring device according to the fifth aspect of the present invention is based on the multi-channel fire extinguishing agent concentration measuring device according to any one of the first to third aspects of the present invention. The gas concentration analysis unit sequentially includes a heating porous medium, a differential pressure porous medium, and a flow limiting member from the upstream side to the downstream side in the gas flow direction. A plurality of heating holes are formed in the heating porous medium, a plurality of differential pressure holes are correspondingly formed in the differential pressure porous medium, and a plurality of flow limiting holes are correspondingly formed in the flow limiting member. The gas channels are sequentially connected by the heating holes, the differential pressure holes, and the flow limiting holes. Each of the gas channels has the same shape and is arranged side by side. Each of the flow limiting holes limits the gas flow velocity at the minimum cross-sectional area of the flow limiting holes at the outlet of each gas channel to the local speed of sound.

[0014] According to the above structure, since a flow limiting hole is provided at the outlet of each gas channel, and the flow limiting hole limits the gas flow velocity at the minimum cross-sectional area of the flow limiting holes at the outlet of each gas channel to the local speed of sound, therefore, the gas flow rate consistency of all gas channels can be achieved, and further the synchronism of all gas channels can be achieved.

[0015] In addition, the multi-channel fire extinguishing agent concentration measuring device according to the sixth aspect of the present invention is based on the multi-channel fire extinguishing agent concentration measuring device according to the fifth aspect of the present invention. A plurality of the gas channels are heated by sharing a heating plate.

[0016] According to the above structure, since a plurality of gas channels are heated by sharing a heating plate, therefore, integrated heating of multiple channels can be achieved, and the gas channels can be synchronously heated to a specified temperature.

[0017] In addition, the multi-channel fire extinguishing agent concentration measuring device according to the seventh aspect of the present invention is based on the multi-channel fire extinguishing agent concentration measuring device according to the sixth aspect of the present invention, and further includes a heat insulation plate that surrounds the heating plate.

[0018] According to the above structure, since the heat insulation plate surrounds the heating plate, therefore, the gas concentration analysis unit can be insulated from the outside, the heating efficiency of the device can be improved, and the safety and stability of the device can be ensured.

[0019] In addition, the multi-channel fire extinguishing agent concentration measuring device according to the eighth aspect of the present invention is based on the multi-channel fire extinguishing agent concentration measuring device according to the sixth or seventh aspect of the present invention. Sensors for measuring the temperature of the gas are provided at the outlets of each of the gas channels. One of the plurality of sensors is used as a temperature control sensor for controlling the temperature of the gas in the gas channel, and the remaining part of the plurality of sensors is used as a fault monitoring sensor for monitoring whether a temperature control failure occurs.

[0020] According to the above structure, since one of the sensors provided at the outlet of each gas channel is used as a temperature control sensor and the remaining ones are used as fault monitoring sensors, not only can the temperature of the gas in the gas channel be controlled, but also whether the sensors fail can be monitored.

[0021] In addition, the multi-channel fire extinguishing agent concentration measuring device according to the ninth aspect of the present invention is based on the multi-channel fire extinguishing agent concentration measuring device according to the eighth aspect of the present invention, and includes: a temperature control unit, the temperature control unit being connected to the heating plate and the sensor; a data acquisition device, the data acquisition device being used to acquire the pressure difference of the measured gas in the pressure difference porous medium; and a data recording device, the data recording device recording the data acquired by the data acquisition device. According to the above structure, since the multi-channel fire extinguishing agent concentration measuring device includes a temperature control unit, a data acquisition device and a data recording device, the temperature of the gas in the gas channel can be controlled, and by setting the data acquisition device, the pressure difference value of the fire extinguishing agent during the process of flowing through the pressure difference porous medium is acquired, and at the same time, in combination with the relational expression between the concentration and the pressure difference, the pressure difference value is converted into a concentration value. By setting the data recording device, the acquired pressure difference value and the converted concentration value are recorded. Thus, the acquisition and recording of the pressure difference and concentration value of the fire extinguishing agent gas are realized.

[0022] In addition, the multi-channel fire extinguishing agent concentration measuring device according to the tenth aspect of the present invention is based on the multi-channel fire extinguishing agent concentration measuring device according to the ninth aspect of the present invention, and the multi-channel fire extinguishing agent concentration measuring device is cross-connected to an airborne test system.

[0023] According to the above structure, since the multi-channel fire extinguishing agent concentration measuring device is cross-connected to an airborne test system, the airborne test system can realize timing for the data acquisition device, enable the relevant parameters of the fire extinguishing agent concentration test to have high-precision timestamp information consistent with other flight parameters, improve the data analysis efficiency, and at the same time ensure the accuracy of the fire extinguishing agent concentration test parameters in terms of time, ensure the accuracy of the concentration maintenance time test data required by the regulations, and provide data support for judging the effectiveness of the fire extinguishing system.

[0024] In addition, the airborne test system can remotely transmit the data acquired from the data acquisition device to a ground control center for monitoring. Therefore, even on the ground, the operation data of the fire extinguishing agent concentration measuring device of the aircraft during the flight test can be analyzed, and at the same time, the operation state of the fire extinguishing agent concentration measuring device can be monitored. Description of the Drawings

[0025] To more clearly illustrate the various technical solutions of the embodiments of the present invention, the accompanying drawings required for the embodiments will be briefly introduced below. Obviously, the accompanying drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other accompanying drawings can be obtained based on these drawings.

[0026] Figure 1 is a schematic diagram showing the overall structure of the multi-channel fire extinguishing agent concentration measuring device according to the first embodiment of the present invention.

[0027] Figure 2 is Figure 1 a partial enlarged view of part A in

[0028] Figure 3 is Figure 1 a partial enlarged view of part B in

[0029] Figure 4 is Figure 1 a partial enlarged view of part C in

[0030] Figure 5 is a schematic diagram showing the detailed internal structure of the gas concentration analysis unit in the multi-channel fire extinguishing agent concentration measuring device according to the first embodiment of the present invention.

[0031] (Symbol description)

[0032] 100 Multi-channel fire extinguishing agent concentration measuring device;

[0033] 10 Sampling tube cleaning unit;

[0034] 11 First cleaning air pipe;

[0035] 12 First three-way switching valve;

[0036] 13 Three-way pipe fitting;

[0037] 14 Second cleaning air pipe;

[0038] 15 Manifold;

[0039] 16 Third cleaning air pipe;

[0040] 17 Filter;

[0041] 18 Second three-way switching valve;

[0042] 20 Gas concentration analysis unit;

[0043] 21 Heating porous medium;

[0044] 211 First gas collecting chamber;

[0045] 212 Heating holes;

[0046] 213 Second gas collection chamber;

[0047] 2131 Upper pressure hole;

[0048] 22 Differential pressure porous medium;

[0049] 221 Differential pressure hole;

[0050] 222 Third gas collection chamber;

[0051] 2221 Lower pressure hole;

[0052] 2222 Temperature measurement hole;

[0053] 23 Temperature sensor;

[0054] 24 Flow limiting member;

[0055] 241 Flow limiting hole;

[0056] 25 Heating plate;

[0057] 26 Heat insulation plate;

[0058] 30 Gas suction unit;

[0059] 31 Confluence device;

[0060] 32 Suction air pipe;

[0061] 33 Vacuum pump;

[0062] 34 Exhaust pipe;

[0063] 40 Temperature control unit;

[0064] 50 Data storage unit;

[0065] 51 Data acquisition device;

[0066] 52 Data recording device;

[0067] 60 On-board test system;

[0068] 200 Sampling tube. Detailed implementation manners

[0069] Hereinafter, with reference to the attached Figures 1-5 Each implementation manner of the multi-channel fire extinguishing agent concentration measurement device of the present invention will be described in detail. Figure 1 It is a schematic diagram showing the overall structure of the multi-channel fire extinguishing agent concentration measurement device according to the first implementation manner of the present invention. Figure 2 It is Figure 1 A partial enlarged view of part A in Figure 3 It is Figure 1 A partial enlarged view of part B inFigure 4 is Figure 1 a partial enlarged view of part C in Figure 5 is a schematic diagram showing the detailed internal structure of the gas concentration analysis unit in the multi-channel fire extinguishing agent concentration measuring device according to the first embodiment of the present invention.

[0070] In the following description, the same reference signs denote the same components or parts. For the same components or parts in the figures, the repeated reference signs are omitted, and the repeated description of the same components or parts is omitted.

[0071] The multi-channel concentration measuring device of the present invention is generally used to measure the fire extinguishing agent concentration in the measurement areas in the aircraft engine compartment, APU compartment and cargo compartment, but is not limited thereto, and can also be applied to measure the fire extinguishing agent concentration in other parts of the aircraft except the above-mentioned measurement points. The "fire extinguishing agent concentration" mentioned here refers to the "volume concentration of the fire extinguishing agent".

[0072] (First Embodiment)

[0073] As Figure 1 shown, the multi-channel fire extinguishing agent concentration measuring device 100 of the present embodiment includes a sampling tube cleaning unit 10, a gas concentration analysis unit 20, a gas suction unit 30, a temperature control unit 40 and a data storage unit 50.

[0074] Among them, as Figure 1 shown, the sampling tube cleaning unit 10 includes a first cleaning gas pipe 11 for the purge nitrogen to flow in, a vacuum suction flow path branched from the first cleaning gas pipe 11, and a first three-way switching valve 12 is provided at the intersection of the first cleaning gas pipe 11 and the vacuum suction flow path. The first three-way switching valve 12 can switch between the three flow paths of the vacuum suction flow path, from the inlet of the first cleaning gas pipe 11 to the intersection, and from the intersection of the first cleaning gas pipe 11 to the three-way pipe fitting 13 described later, to connect or cut off them. A three-way pipe fitting 13 is provided on the downstream side of the gas flow direction of the first three-way switching valve 12, two second cleaning gas pipes 14 branched from the three-way pipe fitting 13 and extending out, four confluence blocks 15 ( Figure 1 shown as 4 in

[0075] The sampling tube cleaning unit 10 configured as described above is formed with twelve third cleaning gas pipes 16, and each third cleaning gas pipe 16 is connected to one sampling tube 200. Therefore, twelve sampling tubes 200 are formed. One end of the sampling tube 200 allows the measured gas at the measurement point to flow in, and the other end is bifurcated and connected to the gas passage of the third cleaning gas pipe 16 and the gas concentration analysis unit 20.

[0076] According to the sampling tube cleaning unit 10 configured as described above, the sampling gas path and the cleaning gas path can be conveniently switched by the switching of the first three-way switching valve 12 and the second three-way switching valve 18, and the nitrogen purge cleaning gas path and the vacuum suction cleaning gas path can be conveniently switched by the switching of the first three-way switching valve 12. For the convenience of more clearly illustrating the switching of the above gas paths in the sampling tube cleaning unit 10, as Figure 2 shown in the enlarged view, the three gas paths switched by the first three-way switching valve 12 are respectively marked as 1, 2, and 3. Among them, "1" represents the gas path from the inlet of the first cleaning gas pipe 11 to the bifurcation of the first cleaning gas pipe 11, "2" represents the vacuum suction flow path 12 branched from the first cleaning gas pipe 11, and "3" represents the gas path from the above bifurcation to the three-way pipe fitting 13. And, as Figure 1 shown, the three gas paths switched by the second three-way switching valve 18 are respectively marked as 4, 5, and 6. Among them, "4" represents the gas path from the inlet of the sampling tube 200 to the bifurcation of the sampling tube 200, "5" represents the gas path extending from the bifurcation of the sampling tube 200 to the third cleaning gas pipe 16, and "6" represents the gas path from the above bifurcation to the gas passage of the gas concentration analysis unit 20.

[0077] When the sampling tube cleaning unit 10 functions as a cleaning gas path, it is necessary to connect the third cleaning gas pipe 16 therein to the above gas path 5.

[0078] If the cleaning method of purging nitrogen is adopted, the first three-way switching valve 12 is switched so that the gas paths 1 and 3 are connected and the gas path 2 is cut off, and the second three-way switching valve 18 is switched so that the gas paths 4 and 5 are connected and the gas path 6 is cut off. At this time, if nitrogen for purging is blown into the first cleaning gas pipe 11, the nitrogen will pass through the first cleaning gas pipe 11, the three-way pipe fitting 13, the second cleaning gas pipe 14, the manifold 15, the third cleaning gas pipe 16, the sampling tube 200 and flow out from the inlet of the sampling tube 200. In this way, the unnecessary gas and other impurities in the sampling tube 200 are extruded by nitrogen, and the unnecessary gas and other impurities can be extruded to the measurement point. Since nitrogen is inert, it will not chemically react with the underlying substances at the measurement point. Thus, it can be avoided that the unnecessary gas and impurities in the sampling tube are sucked into the channel of the gas concentration analysis unit, resulting in distorted measurement results.

[0079] In addition, to prevent impurities purged from the sampling tube 200 from being blown into the engine compartment, APU compartment, or cargo hold, resulting in foreign objects in the compartments and affecting aircraft safety, a vacuum suction cleaning method can also be adopted. Specifically, the first three-way switching valve 12 is switched to connect the "2" and "3" gas paths and cut off the "1" gas path, and the second three-way switching valve 18 is switched to connect the "4" and "5" gas paths and cut off the "6" gas path. At this time, if connected to the vacuum suction flow path through a vacuum suction pump, the gas and impurities in the sampling tube 200 are sucked out in sequence through the "2" and "3" gas paths, the three-way pipe fitting 13, the second cleaning gas pipe 14, the manifold 15, the third cleaning gas pipe 16, and the "4" and "5" gas paths. In this way, by vacuum suction of the gas and impurities in the sampling tube 200, it is possible to prevent unnecessary gas and impurities in the sampling tube from being sucked into the channels of the gas concentration analysis unit, resulting in distorted measurement results.

[0080] As described above, the purging nitrogen and vacuum suction methods can share a set of pipelines, that is, the pipeline composed of the first cleaning gas pipe 11, the second cleaning gas pipe 14, and the third cleaning gas pipe 16, which can simplify the pipeline structure. Moreover, the cleaning gas path of the purging nitrogen and the vacuum suction path can be quickly switched through the first three-way switching valve 12, and the operation is simple.

[0081] As Figure 1 shown, the multi-channel fire extinguishing agent concentration measuring device 100 of this embodiment includes four gas concentration analysis units 20, and each gas concentration analysis unit is provided with three gas channels (refer to Figure 5 ), totaling twelve gas channels.

[0082] Specifically, taking the Figure 5 shown gas concentration analysis unit 20 as an example, it includes: a heating porous medium 21 connected to the outlet of the sampling tube 200, a differential pressure porous medium 22, a flow limiting member 24 installed at the outlet of the differential pressure porous medium 22, a heating metal block (as shown by the shaded part in Figure 5 ), a heating plate 25 and a heat insulating plate 26 that surround the heating metal block from both left and right sides. These components together form three gas channels, and each gas channel is formed along the direction of the dotted arrow through the heating porous medium 21, the differential pressure porous medium 22, and the flow limiting member 24.

[0083] The heating porous medium 21 is sequentially provided with a generally funnel-shaped first gas collecting cavity 211, a main body part formed with 120 heating holes 212, and a second gas collecting cavity 213 connected to the main body part from the upstream side to the downstream side in the gas flow direction. An upper pressure hole 2131 is opened on the peripheral wall of the second gas collecting cavity 213 (the left peripheral wall shown in Figure 2 ).

[0084] Downstream of the outlet of the heated porous medium 21 in the gas flow direction, a differential pressure porous medium 22 is provided. The differential pressure porous medium 22 includes a main body portion having 10 differential pressure holes 221 correspondingly connected to the heated porous medium 21 and a funnel-shaped third gas collecting chamber 222 connected to the main body portion. A downward pressure hole 2221 is formed in the peripheral wall on the left side of the third gas collecting chamber 222, and a temperature measurement hole 2222 is formed in the peripheral wall on the right side of the third gas collecting chamber 222. A temperature sensor 23 for measuring the temperature of the gas to be measured at the third gas collecting chamber 222 is installed in the temperature measurement hole 2222. A flow limiting member 24 is installed at the outlet of the differential pressure porous medium 22. Twelve flow limiting holes 241 are formed in the flow limiting member 24, and the flow limiting member 24 is installed such that the flow limiting holes 241 therein are aligned with the differential pressure holes 221.

[0085] Thus, in each gas concentration analysis unit 20, as Figure 5 shown, a gas passage is formed from the first gas collecting chamber 211, 120 heating holes 212 in the main body portion of the heated porous medium 21, the second gas collecting chamber 213, 10 differential pressure holes 221 in the main body portion of the differential pressure porous medium 22, the third gas collecting chamber 222, and the flow limiting holes 241. Although only three such gas passages are shown in Figure 5 , a total of twelve gas passages are formed as Figure 1 shown. Moreover, a temperature sensor 23 for measuring the temperature is provided at the outlet of each gas passage.

[0086] In Figure 1 , the upstream pressure measured via the upstream pressure hole 2131, the downstream pressure measured via the downstream pressure hole 2221, and the temperature of the gas to be measured measured by the temperature sensor 23 in the above-mentioned twelve gas passages are schematically shown, with a total of twelve groups. For clear distinction and display, as Figure 3As shown, set the upper pressure, lower pressure, and temperature in the first group of gas channels to "upper pressure 1, lower pressure 1, temperature 1" respectively; set the upper pressure, lower pressure, and temperature in the second group of gas channels to "upper pressure 2, lower pressure 2, temperature 2" respectively; set the upper pressure, lower pressure, and temperature in the third group of gas channels to "upper pressure 3, lower pressure 3, temperature 3" respectively; set the upper pressure, lower pressure, and temperature in the fourth group of gas channels to "upper pressure 4, lower pressure 4, temperature 4" respectively; set the upper pressure, lower pressure, and temperature in the fifth group of gas channels to "upper pressure 5, lower pressure 5, temperature 5" respectively; set the upper pressure, lower pressure, and temperature in the sixth group of gas channels to "upper pressure 6, lower pressure 6, temperature 6" respectively; set the upper pressure, lower pressure, and temperature in the seventh group of gas channels to "upper pressure 7, lower pressure 7, temperature 7" respectively; set the upper pressure, lower pressure, and temperature in the eighth group of gas channels to "upper pressure 8, lower pressure 8, temperature 8" respectively; set the upper pressure, lower pressure, and temperature in the ninth group of gas channels to "upper pressure 9, lower pressure 9, temperature 9" respectively; set the upper pressure, lower pressure, and temperature in the tenth group of gas channels to "upper pressure 1A, lower pressure 1A, temperature 1A" respectively; set the upper pressure, lower pressure, and temperature in the eleventh group of gas channels to "upper pressure 1B, lower pressure 1B, temperature 1B" respectively; set the upper pressure, lower pressure, and temperature in the twelfth group of gas channels to "upper pressure 1C, lower pressure 1C, temperature 1C" respectively.

[0087] In the above-mentioned gas channels, since the number of heating holes 212 in the heating porous medium 21 is greater than the number of pressure difference holes 221 in the pressure difference porous medium 22, specifically, twelve heating holes 212 correspond to one pressure difference hole 221, which can correspondingly increase the flow rate of the measured gas flowing through the pressure difference hole 221, so that the pressure drop becomes larger. Thus, it is convenient to obtain the pressure difference of the measured gas flowing through the pressure difference hole 221.

[0088] As Figure 5 shown, taking one pressure difference porous medium 22 as an example, a temperature sensor 23 is provided at the temperature measurement hole 2222 of the third gas collecting cavity 222. There are a total of three temperature sensors 23. The temperature sensor 23 in the middle is used as a temperature control sensor for controlling the temperature of the measured gas in the gas channel. For example, if the temperature of the measured gas detected by this temperature control sensor is too low, the temperature control unit 40 will increase the temperature of the heated heating plate 25, so that the temperature of the measured gas in the gas channel becomes higher. The temperature sensors 23 on the left and right are used as fault monitoring sensors for monitoring whether the above temperature control sensor in the temperature control fails or whether the temperature control unit for collecting and controlling temperature data fails. That is, if the temperature of the measured gas detected by the fault monitoring sensor is significantly different from the temperature of the measured gas detected by the temperature control sensor, it can be judged that the temperature control sensor or the temperature control unit 40 may have failed in the temperature control.

[0089] In this embodiment, in each gas concentration analysis unit 20, heat is transferred to the heating metal block through a heating plate 25, and the three gas channels are heated integrally by the heating metal block, which can reliably ensure that these gas channels are heated to the same temperature for easy temperature control. On this basis, a heat insulation plate 26 is further provided on the outer periphery of the heating plate 25, and the heat insulation plate 26 can insulate the gas concentration analysis unit 20 from the outside. In this way, the temperature of the gas in the gas channels can be heated synchronously to a specific temperature and the above specific temperature can be maintained. In this way, the consistency of temperature control of all gas channels can be improved and the safety of the device can be enhanced.

[0090] As Figure 1 shown, a temperature control unit 40 is further provided, and the temperature control unit 40 is directly connected to the heating plate 25 and the temperature sensor 23 to control the temperature of the gas to be measured in the gas channels after being heated.

[0091] As described above, when the gas to be measured in the gas channels is heated to a specific temperature by the heating plate 25 and the heat insulation plate 26, since a flow limiting orifice 241 is provided at the outlet of each gas channel, these flow limiting orifices 241 can limit the flow rate of the gas to be measured here to the local speed of sound. Since the mass flow rate of the gas to be measured is conserved at various locations in the gas channels and the shapes of the gas channels are the same, the flow rates of all gas channels can be made consistent, and thus the synchronization of all gas channels can be achieved.

[0092] In addition, a gas suction unit 30 is further provided on the downstream side of the gas concentration analysis unit 20 in the gas flow direction, which mainly includes a confluence device 31, a suction gas pipe 32, a vacuum pump 33 and an exhaust pipe 34, etc. The confluence device 31 among them is connected to each flow limiting orifice 241 and is sequentially connected with a suction gas pipe 32, a vacuum pump 33 and an exhaust pipe 34.

[0093] In this way, the gas to be measured sampled from each measurement point into each sampling tube 200 flows out successively through the sampling tube 200, the "4" "6" gas path, the gas channels of the gas concentration analysis unit 20, the confluence device 31, the suction gas pipe 32, the vacuum pump 33 and the exhaust pipe 34.

[0094] Thus, as described above, when the sampling tube cleaning unit 10 functions as a sampling gas path, since the second three-way switching valve 18 is switched to cut off the "5" gas path and connect the "4" and "6" gas paths, the measured gas sucked into the sampling tube 200 under the action of the vacuum pump 33 flows into the gas channel of the gas concentration analysis unit 20 through the sampling tube 200 and flows out from the flow limiting orifice 241, and is restricted to the local sonic speed at the minimum cross-section of the flow limiting orifice 241. Then, it flows into the confluence device 31, the suction air pipe 32, the vacuum pump 33, and finally is discharged from the exhaust pipe 34. In the above process, the measured gas sampled into the sampling tube 200 is heated to a specific temperature (such as 120 °C) successively through the heating porous medium 21, a pressure drop is generated through the differential pressure porous medium 22, and is restricted to the local sonic speed at the minimum cross-section of the flow limiting orifice 241.

[0095] That is to say, the measured gas flowing out from the differential pressure holes 221 of the differential pressure porous medium 22 is restricted to the local sonic speed respectively through the minimum cross-section of the flow limiting orifice 241, that is, the speeds of the same measured gas at the minimum cross-sections of each flow limiting orifice 241 are the same. In this case, the mass flow rate of the fluid m = ρvs, where ρ represents the density of the fluid, v represents the flow velocity of the fluid, and s represents the flow cross-sectional area of the fluid. Corresponding to the multi-channel fire extinguishing agent concentration measuring device of the present embodiment, ρ represents the density of the measured gas, v represents the flow velocity of the measured gas, and s represents the flow cross-sectional area of the measured gas. It can be seen from this that the speed of the measured gas at the minimum cross-section of the flow limiting orifice 241 is the local sonic speed, and the cross-sectional areas of the flow limiting orifices are the same, and the densities of the same-state gases in each gas channel are the same. From this, it can be deduced that the mass flow rate m of the measured gas at the minimum cross-section of the flow limiting orifice 241 限流孔 .

[0096] According to the fluid continuity equation: m = ρvs = C (constant) (this formula can be seen in Chapter 4.2 "Integral Equations of Fluid Mechanics for Control Volumes", Section 4.2.1 "Continuity Equation" of "Fluid Mechanics" [published by Xi'an Jiaotong University Press, edited by Jing Sirui and Zhang Mingyuan]), it can be known that the mass flow rate m of the measured gas at the flow limiting part 限流孔 is the same as the mass flow rate m of the measured gas at any point in the gas channel. 采样管 On this basis, as Figure 5 shown, the shapes of each gas channel are the same and arranged side by side. Therefore, it can be inferred that the time differences of the same measured gas in each gas channel are the same, that is, the synchronism of the flow of the measured gas in each gas channel can be ensured.

[0097] In order to facilitate the measurement of the concentration of the gas to be measured in the differential pressure porous medium 22, it is necessary to measure the differential pressure generated by the upper air pressure P1 when the gas to be measured flows into the differential pressure holes 221 of the differential pressure porous medium 22 and the lower air pressure P2 when it flows out of the differential pressure holes 221. As described above, an upper pressure hole 2131 is provided in the peripheral wall of the second gas collecting chamber 213, and a lower pressure hole 2221 is provided in the third gas collecting chamber 222. In order to measure the temperature of the gas entering the differential pressure porous medium 22 (which can also be said to be the gas at the third gas collecting chamber 222), a temperature measurement hole 2222 is provided in the peripheral wall of the third gas collecting chamber 222 opposite to the lower pressure hole 2221, and a temperature sensor 23 is installed in the temperature measurement hole 2222.

[0098] Moreover, as Figure 1 shown, as described above, the temperature control unit 40 is connected to the heating plate 25 and the temperature sensor 23. Thus, the temperature data measured by the temperature sensor 23 is acquired and analyzed and controlled, and the temperature of the gas in all the gas channels in the gas concentration analysis unit 20 is heated to a certain specific temperature and can be maintained at that specific temperature.

[0099] In addition, as Figure 1 shown, the multi-channel fire extinguishing agent concentration measuring device 100 of the present embodiment further includes: a data acquisition device 51, which acquires the upper air pressure P1 and the lower air pressure P2 via the upper pressure hole 2131 and the lower pressure hole 2221 respectively, and calculates to obtain the differential pressure △P = P1 - P2.

[0100] In fluid mechanics, when a fluid flows in a laminar state in a smooth straight pipe, its frictional pressure loss satisfies the following equation:

[0101]

[0102] (This formula can be seen in "Fluid Mechanics" [published by Xi'an Jiaotong University Press, edited by Jing Sirui and Zhang Mingyuan], Chapter 7.6 "Calculation of Frictional Energy Loss in Circular Pipes and Moody Diagram")

[0103] Among them, Δp is the pressure drop, d is the pipe diameter, μ is the dynamic viscosity coefficient, ν is the fluid flow velocity, and l is the pipe length. The dynamic viscosity coefficient μ is a measure of the fluid viscosity. The dynamic viscosity coefficient of the same fluid has a great relationship with the temperature of the fluid and is less affected by the pressure. (This explanation can be seen in "Fluid Mechanics" [published by Xi'an Jiaotong University Press, edited by Jing Sirui and Zhang Mingyuan], Section 1.2.2 "Viscosity Coefficient"). Thus, the gas to be measured is heated to a certain specific temperature in the heating porous medium 21 and maintains that specific temperature in the differential pressure porous medium 22, and the dynamic viscosity coefficient μ is related to the concentration of the fire extinguishing agent in the gas to be measured.

[0104] Corresponding to the multi-channel fire extinguishing agent concentration measuring device 100 of this embodiment, Δp is the pressure difference of the measured gas in the pressure difference holes 221 of the pressure difference porous medium 22, d is the diameter of the pressure difference holes 221 (a certain fixed value), l is the length of the pressure difference holes 221 in the pressure difference porous medium 22 (a certain fixed value), and v is the flow rate of the measured gas in the pressure difference holes 221 (related to the concentration of the fire extinguishing agent in the measured gas). Therefore, the variable Δp in the above equation (1) changes with the change of the concentration of the fire extinguishing agent in the measured gas.

[0105] In the test stage, the concentration values ρ1, ρ2, ρ3 of the measured gas can be calculated based on the obtained different pressure differences Δp1, Δp2, Δp3.

[0106] In order to calculate the concentration values ρ1, ρ2, ρ3 of the measured gas based on the obtained different pressure differences Δp1, Δp2, Δp3, the multi-channel fire extinguishing agent concentration measuring device is calibrated. Different concentrations of fire extinguishing agent gas (with known concentration values) are introduced into all channels of the fire extinguishing agent concentration measuring device, and the corresponding output pressure differences of the fire extinguishing agent gas with different concentrations can be obtained. Through mathematical fitting, the relationship between concentration and pressure difference can be obtained.

[0107] In order to obtain the above pressure differences Δp1, Δp2, Δp3 and calculate the concentration ρ1, ρ2, ρ3 of the measured gas based on the above pressure differences, the multi-channel fire extinguishing agent concentration measuring device 100 of this embodiment further includes a data storage unit 50, including: a data acquisition device 51 that acquires the values of the upper pressure P1 and the lower pressure P2 in twelve gas channels (specifically, as shown in Figure 3 "1 upper pressure", "1 lower pressure", "2 upper pressure", "2 lower pressure", "3 upper pressure", "3 lower pressure", "4 upper pressure", "4 lower pressure", "5 upper pressure", "5 lower pressure", "6 upper pressure", "6 lower pressure", "7 upper pressure", "7 lower pressure", "8 upper pressure", "8 lower pressure", "9 upper pressure", "9 lower pressure", "1A upper pressure", "1A lower pressure", "1B upper pressure", "1B lower pressure", "1C upper pressure", "1C lower pressure"), and at the same time, in combination with the relationship between concentration and pressure difference, converts the pressure difference value into a concentration value; and a data recording device 52 that records the acquired pressure difference values and the converted concentration values. In this way, it is convenient for the ground control center to display the pressure difference and concentration of the measured gas in the gas channels in the gas concentration analysis unit 20 in real time.

[0108] In addition, as Figure 1 and Figure 4As shown, the multi-channel fire extinguishing agent concentration measuring device 100 of this embodiment is cross-connected to the airborne test system 60. The airborne test system 60 times the data acquisition device 51, for example, by IEEE1588 or IRIG-B code timing, and times the acquisition data in the multi-channel fire extinguishing agent concentration measuring device 100, so that the time of these parameters is synchronized with, for example, Beijing time. The fire extinguishing agent concentration test parameters obtained by the multi-channel fire extinguishing agent concentration measuring device have high-precision timestamp information consistent with other flight parameters, improving the data analysis efficiency. At the same time, it ensures the accuracy of the time of the fire extinguishing agent concentration test parameters, ensures the accuracy of the concentration maintenance time test data required by the regulations, and provides data support for judging the effectiveness of the aircraft fire extinguishing system. Moreover, the airborne test system 60 includes telemetering the fire extinguishing agent concentration test parameters calculated as described above to the ground control center for real-time monitoring, and sending them to the airborne data recorder for backup recording.

[0109] (Technical effects of the multi-channel fire extinguishing agent concentration measuring device of this embodiment)

[0110] According to the multi-channel fire extinguishing agent concentration measuring device of this embodiment, since multiple channels are provided in one device, in the case of multiple measurement points, there is no need to prepare multiple single-channel fire extinguishing agent concentration measuring devices correspondingly. Compared with the prior art, it can reduce the number of components and simplify the measurement operation.

[0111] Above, in order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the first embodiment of the present invention has been clearly and completely described in conjunction with the drawings in the embodiments of the present invention. Obviously, the described first embodiment is part of the embodiments of the present invention, rather than all of the embodiments. Based on the above first embodiment, all other embodiments obtained by those of ordinary skill in the art without creative efforts fall within the scope of the present invention to be protected.

[0112] As described above, the first embodiment of the present invention has been described. However, in addition to the technical solutions described in the above first embodiment, the elements of the first embodiment can also be combined and used to obtain other technical solutions of the present invention without departing from the purpose of the present invention, and these technical solutions all fall within the scope of the present invention to be protected.

[0113] In the above embodiment, the sampling gas path of the sampling tube cleaning unit adopts two methods of purging nitrogen and vacuum suction, but the present invention is not limited to this, and only one of the methods can also be adopted.

[0114] In the above-described embodiment, the sampling tube cleaning unit is connected in series using a manifold block to clean all the sampling tubes. However, the present invention is not limited thereto. Each gas channel sampling tube can also be cleaned individually, or each concentration analysis unit sampling tube can be cleaned individually.

[0115] In the above-described embodiment, the sampling tube cleaning unit includes twelve sampling channels. Correspondingly, the gas concentration analysis unit includes twelve gas channels. However, the present invention is not limited thereto. As long as the number is greater than 1, other numbers are also possible.

[0116] In the above-described embodiment, the airborne test system synchronizes the data acquisition device using IEEE1588 or IRIG-B code. However, the present invention is not limited thereto, and other methods can also be used to synchronize the data acquisition device.

[0117] In the above-described embodiment, the temperature sensor for measuring the temperature of the gas in the gas channel is provided at the outlet of the gas channel. However, the present invention is not limited thereto, and it can also be provided at other parts of the gas channel.

[0118] In the above-described embodiment, the gas is suctioned through the heated porous medium 21 and heated. However, the present invention is not limited thereto, and other heating methods are also possible.

[0119] In the above-described embodiment, the gas is suctioned through the heated porous medium 21 and heated to a specific temperature (e.g., 120 °C). However, the present invention is not limited thereto. As long as the heating temperature is greater than the critical temperature of the gas, the heating temperature can also be other values.

[0120] In the above-described embodiment, there are 120 heating holes 212 formed in the heated porous medium 21, and 10 pressure difference holes 221 formed in the pressure difference porous medium 22. However, the present invention is not limited thereto. As long as the number of heating holes is greater than the number of pressure difference holes, other numbers are also possible.

[0121] In the above-described embodiment, the layout of the gas channels of the fire extinguishing agent concentration measuring device of the present invention is four gas concentration analysis units, and each concentration analysis unit has three gas channels, that is, in the 3×4 manner. Among the three temperature sensors provided in the three gas channels, one is used as the temperature control sensor, and the rest are used as fault monitoring sensors. However, the present invention is not limited thereto, and other layouts can also be adopted, and the number and setting method of the temperature control sensor and the fault monitoring sensor can be changed according to the specific layout.

Claims

1. A multi-channel fire extinguishing agent concentration measuring device, comprising: a gas concentration analysis unit, the gas concentration analysis unit comprising a plurality of gas channels connected to outlets of a plurality of sampling tubes; as well as A gas suction unit, the gas suction unit is connected to the outlet of the gas concentration analysis unit, sucks the gas therein and discharges it, It is characterized in that The multiple gas channels of the gas concentration analysis unit sample the gas to be measured through multiple sampling tubes respectively.

2. The multi-channel fire extinguishing agent concentration measuring device according to claim 1, characterized in that: Also included is a sampling tube cleaning unit, the sampling tube cleaning unit comprising: A cleaning pipeline, wherein the cleaning pipeline is bifurcated into a first cleaning gas path and a second cleaning gas path at an inlet, and an outlet end is connected to the sampling tube; and A first gas path switching unit is configured to switch between the first clean gas path and the second clean gas path.

3. The multi-channel fire extinguishing agent concentration measuring device according to claim 2, characterized in that: It also includes a second gas circuit switching unit, which is arranged at the outlet and switches between the sampling gas circuit connecting the sampling tube and the gas concentration analysis unit and the cleaning gas circuit connecting the sampling tube cleaning unit and the sampling tube.

4. The multi-channel fire extinguishing agent concentration measuring device according to claim 2 or 3, characterized in that: The first cleaning gas path and the second cleaning gas path of the cleaning pipeline share a set of pipelines, The first gas path switching unit and the second gas path switching unit adopt three-way switching valves.

5. The fire extinguishing agent concentration measuring device according to any one of claims 1 to 3, characterized in that: The gas concentration analysis unit includes a heating porous medium, a pressure difference porous medium and a flow limiting component in order from the upstream side to the downstream side of the gas flow direction, wherein a plurality of heating holes are formed in the heating porous medium. A plurality of pressure difference holes are correspondingly formed in the pressure difference porous medium. A plurality of flow limiting holes are correspondingly formed in the flow limiting component. The gas channel is formed by sequentially connecting the heating hole, the pressure difference hole, and the flow limiting hole. The gas channels are of the same shape and arranged side by side. Each of the flow-limiting holes limits the gas flow velocity at the minimum cross-section of the flow-limiting hole at the outlet of each gas channel to the local sound velocity.

6. The fire extinguishing agent concentration measuring device according to claim 5, characterized in that: The plurality of gas channels are heated by sharing a heating plate.

7. The fire extinguishing agent concentration measuring device according to claim 6, characterized in that: Also included is a heat insulation plate, which surrounds the heating plate.

8. The fire extinguishing agent concentration measuring device according to claim 6 or 7, characterized in that: A sensor for measuring the temperature of the gas is provided at the outlet of each of the gas channels. One of the plurality of sensors is used as a temperature control sensor for controlling the temperature of the gas in the gas passage, The remaining part of the plurality of sensors is used as a fault monitoring sensor for monitoring whether a fault occurs in the temperature control.

9. The fire extinguishing agent concentration measuring device according to claim 8, characterized in that: include: A temperature control unit connected to the heating plate and the sensor; A data acquisition device, the data acquisition device is used to collect the pressure difference of the measured gas in the pressure difference porous medium; as well as A data recording device records the data collected by the data collection device.

10. The fire extinguishing agent concentration measuring device according to claim 9, characterized in that: The multi-channel fire extinguishing agent concentration measuring device is cross-linked with the airborne testing system.

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