CN108896453B - Multi-parameter adjustable mist flow experiment system - Google Patents
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Abstract
The invention relates to a multi-parameter adjustable mist flow experiment system which comprises an air source module, a flow regulating valve, a vortex flowmeter, a water storage tank, a metering pump, a frequency converter, an atomization mixing section, a liquid film collecting device, an extinction method particle measuring instrument and a throttle valve, wherein air provided by the air source module is sent into the atomization mixing section through the flow regulating valve, and the gas phase flow is metered by the vortex flowmeter; the water provided by the water storage tank is regulated by a metering pump and a frequency converter, then passes through a high-pressure nozzle and is atomized to form micron-sized liquid drops, the micron-sized liquid drops enter an atomization mixing section, the water flow is controlled by the metering pump, the metering pump is combined in a frequency modulation mode and a stroke modulation mode to carry out flow regulation, and the frequency is continuously regulated by the frequency converter; the gas phase and the liquid phase form mist flow in an atomizing and mixing section, then enter a liquid film collecting device, the air displacement is controlled and measured through a throttle valve, and the particle size and the concentration of liquid drops in a pipeline after passing through the liquid film collecting device are measured by an extinction method particle measuring instrument.
Description
Technical Field
The invention belongs to the field of gas-liquid two-phase flow parameter measurement, and relates to a multi-parameter adjustable mist flow experiment system.
Background
Gas-liquid two-phase flows are widely present in modern industrial plants. The mist flow is an important flow pattern of gas-liquid two-phase flow, the gas phase is a continuous phase, the liquid phase is a discrete phase, and most or all of the liquid phase is entrained by the gas phase in a droplet form. The high-efficiency energy-saving fire extinguisher is commonly used in fire extinguishers, various engine combustion chambers and underwater propelling devices, and has important significance on the safety, economy and energy conservation of industrial equipment operation, such as flow, dryness, pressure drop, section content and the like [1 ].
Due to the importance of the mist flow pattern in industrial production, intensive research has been carried out on mist flow and its flow measurement. For the study of mist flow, two-phase pressure drop [2], cross-sectional void fraction, droplet deposition, flow stability [3], and volume gas fraction [4] are of common interest. Regarding the flow measurement of the mist flow, there are mainly a separation method and an on-line measurement method, wherein the method of performing on-line measurement by using a conventional single-phase flow meter is widely used, but in the two-phase flow, the liquid phase has a great influence on the flow metering characteristics, and a targeted correction is required [5 ]. For the above research, both theoretical modeling and numerical simulation require real-time experiments to verify and find out new problems that may exist.
At present, most of mist flow experiments are carried out on a multi-phase flow device, wherein gas and liquid phases are mixed by an ejector [5] to [8 ]. The formation of a mist flow in the ejector requires strict conditions and the droplets are liable to deposit along the way, which affects the formation of the mist flow pattern. In addition, most of mist flow experiments are carried out under normal pressure [5] [6] [8], the influence of pressure change on flow measurement is ignored, the adaptability of a correction model is poor, and the problem of flow correction cannot be fundamentally solved. For the parameter adjustment of the mist flow pattern, because the influence parameters are more, all the parameters are coupled with each other, which causes difficulty for the adjustment and control of the flow parameters.
Reference to the literature
[1] Calculating and analyzing a fog-shaped gas-liquid two-phase flow field in a spray pipe [ J ] proceedings of Harbin university, 2010,42(9): 1363-.
[2] Wuning, Hushuchun, Kudzuvine, etc. analytical model of variable mass gas-liquid two-phase annular atomized flow pressure drop in horizontal well bore [ J ] oil geology and engineering, 2001,15(2):35-37.
[3] Gaoqinghua, Li Tiantai, Zhaoyije, et al, simulation study of flow characteristics of gas-liquid two-phase flow in well bore [ J ]. proceedings of Yangtze river university (from the Spt.), 2014(14) 84-87.
[4] The volume air content of low-pressure annular fog flow and liquid beam annular flow is measured by a U-shaped pipe [ J ]. the chemical industry report, 2008,59(5):1131 and 1135.
[5] Jayunfei, Konderen, vortex flow meter fog flow measuring model based on wave theory [ J ]. chemical industry report, 2009,60(3):601-607.
[6]Nederveen N Washington G V Batstra F H Wet gas flow measurement[A]SPE Annual Technical Conference[C]San Antonio TX 1989.
[7]Andrew Hall,Richard Steven.A discussion on vortex meter technologies with wet gas flows.7th South Easr Asia Hydrocardon Flow Measurement Workshop,5th-7th March,2008.
[8]Jia Y F,Zhang T,Zhang Q P.An experimental study of vortex flowmeter used in wet gas[J].Jiliang Xuebao/acta Metrologica Sinica,vol 30(3),pp.225-229,2009.
Disclosure of Invention
The invention aims to provide a multi-parameter adjustable mist flow experiment system, which can form a stable mist flow pattern and accurately control gas phase flow, pressure and liquid drop concentration. Therefore, the invention adopts the following technical scheme:
a multi-parameter adjustable fog flow experiment system comprises an air source module, a flow regulating valve, a vortex flow meter, a water storage tank, a metering pump, a frequency converter, an atomization mixing section, a liquid film collecting device, an extinction method particle measuring instrument and a throttle valve, wherein,
air provided by the air source module is fed into the atomization mixing section after passing through the flow regulating valve, and the gas phase flow is measured by the vortex shedding flowmeter;
the water provided by the water storage tank is regulated by a metering pump and a frequency converter, then passes through a high-pressure nozzle and is atomized to form micron-sized liquid drops, the micron-sized liquid drops enter an atomization mixing section, the water flow is controlled by the metering pump, the metering pump is combined in a frequency modulation mode and a stroke modulation mode to carry out flow regulation, and the frequency is continuously regulated by the frequency converter;
the gas phase and the liquid phase form mist flow in an atomization mixing section, then enter a liquid film collecting device, the control and the measurement of the displacement are carried out through a throttle valve, the liquid film collecting device realizes the complete collection of the liquid film, and the particle size and the concentration of liquid drops in a pipeline are measured by an extinction method particle measuring instrument after passing through the liquid film collecting device;
in order to realize the adjustment of the mist flow parameters, a multi-parameter control system is adopted, and the pressure-flow coupling control is divided into two parts by the combination of a flow regulating valve and a throttle valve: the pressure-flow regulating valve control part and the flow-throttle valve control part adopt feedforward-feedback control on pressure and flow to eliminate the interference of gas phase pressure and flow on the concentration of liquid drops; let R3(s) is the set point for the droplet concentration, Gc3(s) is a concentration controller, Gff(s) is a feedforward controller, Gv(s) frequency converters and metering pumps, Gp3(s) a liquid film collecting device, H3(s) particle measurement apparatus for extinction method, Gd1(s) and Gd2(s) is the disturbance channel transfer function, Y3(s) is a droplet concentration measurement, e3(s) deviation of the set point and the measured value of the droplet concentration, the feed forward signal being present in the concentration controller Gc3After(s), to overcome the gas-phase pressure Y1(s) and flow rate Y2(s) disturbance effect on the concentration of the liquid drops, and the feedback control overcomes the influence of other non-measurable disturbances in the loop, so that the concentration of the liquid drops reaches a set value R3(s)。
Preferably, the liquid film collecting device comprises three parts of an infiltration collecting system, a flow control system and a metering weighing system, wherein,
the infiltration collecting system comprises a porous infiltration pipeline, a sleeve, a blowdown valve, a three-way valve and a control valve, wherein the middle section of the porous infiltration pipeline is a porous section and is positioned in the sleeve, a flow guide hole is formed in the lower part of the sleeve, fluid infiltrated through the porous section flows out through the flow guide hole, then flows through the three-way valve, enters a water storage container of the metering and weighing system through the control valve, is subjected to gas-liquid separation in the water storage container, is metered and discharged through the flow control system, and is stored in the water storage container; the side end of the three-way valve is communicated with the outside through a drain valve;
the flow control system comprises a float flowmeter and an exhaust valve, wherein the exhaust valve controls the exhaust of gas, and the exhaust amount is measured by the float flowmeter.
The porous section is made of a porous filter element sintered material. The metering and weighing system comprises a water storage container, a barrel cover, a drying agent, a support, an electronic scale and a drain valve, wherein the water storage container is fixed above the electronic scale through the support, and gas entering the water storage container is discharged from a guide pipe connected with the barrel cover and enters the flow control system.
The invention has the following substantive characteristics and beneficial effects:
1) by means of atomization and mixing. Air is provided by an air source module, the pressure and the air flow are controlled by a combination of a regulating valve and a throttle valve, the pressure regulating range is 0.1-0.7 MPa, and the flow regulating range is 5-25 m3H is used as the reference value. The flow rate is measured by a vortex flowmeter, and the calibration measurement precision is +/-1.0%. The water is provided by the water storage tank, the water flow is accurately controlled by the metering pump, the flow range is 0-17L/h, and the calibration measurement precision is +/-2.0%. The micron-sized liquid drops atomized by the high-pressure water nozzle are mixed with the air flow in the mixing section. For the pipeline design of the mixing section, in order to avoid the direct impact of the ejected liquid drops on the pipe wall, the mixing is carried out in a DN50 section, then the diameter expansion is DN100, the liquid drops and the gas phase are fully mixed, and then the pipe diameter is gradually reduced to a DN15 experimental section. And separating a liquid film formed by the deposition of the liquid drops by a liquid film collecting device, and then measuring the particle size and the concentration of the liquid drops by an extinction method particle size measuring instrument.
2) On the basis of the experimental device, in order to realize accurate adjustment of the mist flow parameters, a multi-parameter control system based on a PLC is designed. Through the combination of the regulating valve and the throttle valve, the pressure-flow coupling system is divided into two parts: a pressure-regulating valve control system and a flow-throttling valve control system to achieve rapid regulation of pressure and flow. The vapor pressure and flow rate can affect the deposition process of the droplets and, in turn, the droplet concentration of the mist stream. And the feed-forward-feedback control is adopted to eliminate the interference of gas phase pressure and flow on the concentration of the liquid drops so as to realize the quick and accurate adjustment of the concentration of the liquid drops.
Drawings
FIG. 1: multi-parameter adjustable fog flow experiment system structure diagram
FIG. 2: structure of atomization mixing section
FIG. 3: structure of liquid film collecting device
FIG. 4: system block diagram for controlling fog flow parameters
FIG. 5: spedding flow chart
FIG. 6: a control system block diagram, wherein p is a pressure set value, pmAs a pressure measurement, e1Deviation of pressure set-point from measured value, QgIs a flow set value, QgmAs a measure of flow, e2Is the deviation of the flow rate set value from the measured value, phi is the concentration set value, phimAs a concentration measurement, e3Is the deviation of the concentration set point from the measured value.
Detailed Description
In order to further understand the features and technical means of the present invention and achieve specific objects and functions, the following detailed description of the embodiments of the present invention is provided with reference to the accompanying drawings.
The structure diagram of the multi-parameter adjustable mist flow experiment system is shown in figure 1, and mainly comprises an air source module 1, a flow regulating valve 2, a vortex shedding flowmeter 3, a water storage tank 4, a metering pump 5, a frequency converter 6, an atomization mixing section 7, a liquid film collecting device 8, an extinction method particle measuring instrument 9, a throttle valve 10 and the like. Air is provided by an air source module 1, air flow and pressure are controlled by a flow regulating valve 2 and a throttle valve 10 in a combined mode, and the flow regulating range is 5-25 m3The pressure adjusting range is 0.1-0.7 MPa. The gas phase flow is measured by a vortex flowmeter 3, and the calibration measurement precision is +/-1.0%. Water is supplied by a water storage tank 4, and the water flow is accurately controlled by a metering pump 5. The metering pump performs flow regulation by combining frequency modulation and stroke modulation, wherein the frequency is continuously regulated by the frequency converter 6. The metering pump 5 controls the liquid phase flow range to be 0-17L/h, and the measurement precision is +/-2.0% after the real-time calibration of a calibration system. The water and the air enter an atomization mixing section 7, and form mist flow by adopting a direct atomization mixing mode and enter a liquid film collecting device 8. The liquid film collecting device 8 can realize complete collection of the liquid film by accurately controlling and measuring the displacement. The particle size and concentration of the droplets in the line are measured by the particle measurement instrument 9 by the extinction method.
Structure diagram of atomizing mixing section referring to fig. 2, the liquid phase is atomized into micron-sized droplets by using a high-pressure water nozzle 11 in a direct atomizing mixing manner and mixed with the air flow in a vertical pipe. The model selection principle of the high-pressure water nozzle is as follows: according to the required droplet particle size, the pressure range corresponding to different types of nozzles is determined, and then the flow range corresponding to the nozzles is determined according to the pressure range, so that the droplet particle size under different flow rates can meet the experimental requirements. In order to avoid the direct impact of the liquid drops at the spray hole on the pipe wall, the spray hole of the spray nozzle is vertically placed downwards at the spray nozzle, and the pipe diameter is expanded from DN15 to DN 50. The diameter of the liquid drop is expanded to DN100 after DN50 pipeline, the liquid drop and the gas phase are fully mixed, then the pipe diameter is gradually reduced to DN15, and the liquid drop enters into the mist flow experiment section.
The structure diagram of the liquid film collecting device is shown in figure 3, and the liquid film collecting device mainly comprises a bolt hole 8-1, a flange 8-2, a porous permeation pipeline 8-3, a transparent sleeve 8-4, a blow-down valve 8-5, a three-way valve 8-6, a control valve 8-7, a clamp 8-8, a water storage container 8-9, a drain valve 8-10, a float flowmeter 8-11, an exhaust valve 8-12, a clamp 8-13, a barrel cover 8-14, a drying agent 8-15, a liquid level meter 8-16, a clamp 8-17, a support 8-18 and an electronic scale 8-19. The middle part of the porous permeation pipeline 8-3 is a porous section which is convenient to weld with the flange 8-2, and stainless steel sections are arranged at the front and the rear of the porous section to prevent welding materials from blocking permeation holes. In order to avoid liquid drops from seeping out of the pipeline along with the liquid film while ensuring the liquid film collecting effect, the porous section is made of a porous filter element sintering material, and the pore diameter is 100 mu m. In order to prevent the porous section from being blocked, a drain valve 8-5 is designed to periodically drain the porous permeation pipeline 8-3. When in pollution discharge, the three-way valve 8-6 is rotated, and the pollution discharge valve 8-5 is opened, so that the pollution discharge end discharges downwards, and the dirt is prevented from falling into the flow guide hole. And opening the exhaust valve 8-12, communicating the device with the outside, wherein the pressure of the device is the ambient atmospheric pressure, and the device and the pressure of the two-phase flow in the pipeline form osmotic pressure, so that the liquid film seeps out of the porous section. In order to avoid incomplete liquid film collection caused by water accumulation of the transparent sleeve 8-4, two flow guide holes are formed in the lower portion of the transparent sleeve 8-4 and are respectively positioned on two sides of the transparent sleeve 8-4. The collected mixture of air and water enters a water storage container through a control valve 8-7, after gas-liquid separation, the air is discharged through a guide pipe connected with a barrel cover 8-14, the air discharge is controlled by an exhaust valve 8-12, the air discharge is measured by a float flowmeter 8-11, and data are remotely transmitted. In order to prevent the liquid from being discharged with the air, a drying agent 8-15 is arranged in the water storage container 8-9 near the top part and is used for absorbing liquid drops in the air. In order to conveniently replace parts, a detachable barrel cover is adopted. The collected liquid film is stored in a water storage container 8-9, and the liquid level can be observed through a liquid level meter 8-16 outside the container. In order to avoid measuring errors of the electronic scales 8-19 caused by the change of the gravity center of the container, brackets 8-18 are arranged outside the container and fixed with the base. In order to realize the automatic collection of the mass of the liquid film, an electronic scale capable of remotely transmitting data is adopted. And recording the change of the output mass of the electronic scales 8-19 in a period of time, and calculating to obtain the average flow of the collected liquid film. In order to collect the liquid film completely, the control strategies adopted are as follows: setting initial air displacement, and measuring the average flow in the current time period after the pressure, the temperature, the differential pressure and the like of the system are stable. After the displacement is increased according to a certain rule, the average flow rate is calculated again. Comparing the two measurement results, if the difference is less than 5%, determining that the liquid film is completely collected, otherwise, continuously multiplying the air displacement. When the liquid in the container is excessive, the drainage valve 8-10 is opened to discharge the liquid. To facilitate disassembly and assembly, the pipes are connected by clamps 8-8, 8-13, 8-17.
Based on the experimental device, in order to realize accurate adjustment of the mist flow parameters, a multi-parameter control system based on a PLC (see fig. 4) is designed. For the adjustment of gas phase pressure and flow, a pressure-flow coupling algorithm is adopted, and a coupling system is divided into two parts: a pressure-regulating valve control system and a flow-throttling valve control system to achieve rapid regulation of pressure and flow. Wherein R is1(s) is the pressure set point, Gc1(s) is a pressure controller, Gp1(s) is a flow regulating valve, H1(s) is a pressure transmitter, Y1(s) is a pressure measurement, e1(s) is the deviation of the pressure set point from the measured value. R2(s) is the flow set point, Gc2(s) is a flow controller, Gp2(s) is a throttle valve, H2(s) is a vortex shedding flowmeter, Y2(s) is the measured flow, e2(s) is the deviation of the flow set point from the measured value. The control strategy is as follows:
1) according to the pressure set value R1(s) the controller opens the regulating valve to make the pipeline internal pressureForce Y1(s) reaching the set value, detecting the current flow value Y2After(s), the deviation e is calculated2(s)，e2(s)>0 then decreases the throttle opening, e2(s)<Increasing the opening of the throttle valve when the throttle valve is 0;
2) the flow rate reaches the target flow rate R2(s), the controller detects the current pressure value Y1(s) calculating the deviation e1(s)，e1(s)>0 then increasing the opening of the flow regulating valve, e1(s)>Reducing the opening of the flow regulating valve when the flow regulating valve is 0;
3) when the flow is adjusted to the target pressure, the controller executes the step 1) to readjust the flow; when the pressure is adjusted to the target flow, the controller executes the step 2) to readjust the pressure;
4) and (4) repeating the step 3) until the pressure and the flow rate reach the set targets of the experiment.
The vapor pressure and flow rate can affect the deposition process of the droplets and, in turn, the droplet concentration of the mist stream. Therefore, the droplet concentration is controlled by feedforward-feedback. The feedforward control can overcome the interference of the change of air flow and pressure on the concentration of liquid drops, and the feedback control determines the water flow input according to the deviation of the concentration of the liquid drops, thereby improving the control accuracy. Wherein R is3(s) is the set point for the droplet concentration, Gc3(s) is a concentration controller, Gff(s) is a feedforward controller, Gv(s) frequency converters and metering pumps, Gp3(s) a liquid film collecting device, H3(s) particle measurement apparatus for extinction method, Gd1(s) and Gd2(s) is the disturbance channel transfer function, Y3(s) is a droplet concentration measurement, e3(s) is the deviation of the drop concentration setpoint from the measured value. The feed-forward signal being present in the feedback controller Gc3After(s), the gas phase pressure Y is overcome in time1(s) and flow rate Y2(s) disturbance effect on the concentration of the liquid drops, and the feedback control overcomes the influence of other non-measurable disturbances in the loop, so that the concentration of the liquid drops reaches a set value R3(s)。
In order to verify the experimental effect of the device, three groups of real flow tests with different pressures are carried out based on the built pressure-adjustable mist flow experimental system, and the experimental working conditions and the vertical direction of speed are adjustedA comparison is made in a pipe flow diagram, see FIG. 5, where p is pressure and the abscissa is the liquid phase flow QLWith gas phase flow rate QGThe ordinate is the Froude number Fr ═ (j)G+jL)2/gD, wherein jG、jLThe apparent flow rates of the gas phase and the liquid phase, respectively, g is the gravitational acceleration, and D is the pipe diameter. The results show that: the device can form stable fog flow, and the estimated liquid drop content is about 50-75% of the total liquid phase. Fig. 6 is a control system block diagram.
The above embodiments are intended to explain the technical solutions of the device structure, the control strategy, etc. of the present invention in detail, and the present invention is not limited to the above implementation routines, but it is within the scope of the present invention that a person of ordinary skill in the art should modify and replace the present invention based on the above principles and spirit.
Claims (4)
1. A multi-parameter adjustable fog flow experiment system comprises an air source module, a flow regulating valve, a vortex flow meter, a water storage tank, a metering pump, a frequency converter, an atomization mixing section, a liquid film collecting device, an extinction method particle measuring instrument and a throttle valve, wherein,
air provided by the air source module is fed into the atomization mixing section after passing through the flow regulating valve, and the gas phase flow is measured by the vortex shedding flowmeter;
the water provided by the water storage tank is regulated by a metering pump and a frequency converter, then passes through a high-pressure nozzle and is atomized to form micron-sized liquid drops, the micron-sized liquid drops enter an atomization mixing section, the water flow is controlled by the metering pump, the metering pump is combined in a frequency modulation mode and a stroke modulation mode to carry out flow regulation, and the frequency is continuously regulated by the frequency converter;
the gas phase and the liquid phase form mist flow in an atomization mixing section, then enter a liquid film collecting device, the control and the measurement of the displacement are carried out through a throttle valve, the liquid film collecting device realizes the complete collection of the liquid film, and the particle size and the concentration of liquid drops in a pipeline are measured by an extinction method particle measuring instrument after passing through the liquid film collecting device;
in order to realize the adjustment of the mist flow parameters, a multi-parameter control system is adopted, and a flow regulating valve and a throttle valve are usedIn combination, the pressure-flow coupling control is divided into two parts: the pressure-flow regulating valve control part and the flow-throttle valve control part adopt feedforward-feedback control on pressure and flow to eliminate the interference of gas phase pressure and flow on the concentration of liquid drops; let R3(s) is the set point for the droplet concentration, Gc3(s) is a concentration controller, Gff(s) is a feedforward controller, Gv(s) frequency converters and metering pumps, Gp3(s) a liquid film collecting device, H3(s) particle measurement apparatus for extinction method, Gd1(s) and Gd2(s) is the disturbance channel transfer function, Y3(s) is a droplet concentration measurement, e3(s) deviation of the set point and the measured value of the droplet concentration, the feed forward signal being present in the concentration controller Gc3After(s), to overcome the gas-phase pressure Y1(s) and flow rate Y2(s) disturbance effect on the concentration of the liquid drops, and the feedback control overcomes the influence of other non-measurable disturbances in the loop, so that the concentration of the liquid drops reaches a set value R3(s); and, let R1(s) is the pressure set point, Gc1(s) is a pressure controller, Gp1(s) is a flow regulating valve, H1(s) is a pressure transmitter, e1(s) is the deviation of the pressure set point from the measured value; r2(s) is the flow set point, Gc2(s) is a flow controller, Gp2(s) is a throttle valve, H2(s) is a vortex shedding flowmeter, e2(s) is the deviation between the flow set value and the measured value, and the control strategy is as follows:
1) according to the pressure set value R1(s) the controller opens the regulating valve to make the gas phase pressure Y in the pipeline1(s) reaching the set value, detecting the current flow value Y2After(s), the deviation e is calculated2(s)，e2(s)>0 then decreases the throttle opening, e2(s)<Increasing the opening of the throttle valve when the throttle valve is 0;
2) the flow rate reaches the target flow rate R2(s), the controller detects the current pressure value Y1(s) calculating the deviation e1(s)，e1(s)>0 then increasing the opening of the flow regulating valve, e1(s)>Reducing the opening of the flow regulating valve when the flow regulating valve is 0;
3) when the flow is adjusted to the target pressure, the controller executes the step 1) to readjust the flow; when the pressure is adjusted to the target flow, the controller executes the step 2) to readjust the pressure;
4) and (4) repeating the step 3) until the pressure and the flow rate reach the set targets of the experiment.
2. The experimental system according to claim 1, wherein the liquid film collecting device comprises three parts of an infiltration collecting system, a flow control system and a metering and weighing system,
the infiltration collecting system comprises a porous infiltration pipeline, a sleeve, a blowdown valve, a three-way valve and a control valve, wherein the middle section of the porous infiltration pipeline is a porous section and is positioned in the sleeve, a flow guide hole is formed in the lower part of the sleeve, fluid infiltrated through the porous section flows out through the flow guide hole, then flows through the three-way valve, enters a water storage container of the metering and weighing system through the control valve, is subjected to gas-liquid separation in the water storage container, is metered and discharged through the flow control system, and is stored in the water storage container; the side end of the three-way valve is communicated with the outside through a drain valve;
the flow control system comprises a float flowmeter and an exhaust valve, wherein the exhaust valve controls the exhaust of gas, and the exhaust amount is measured by the float flowmeter.
3. The assay system of claim 2, wherein the porous segment is made of a porous cartridge sintered material.
4. The experimental system of claim 2, wherein the metering and weighing system comprises a water storage container, a barrel cover, a drying agent, a support, an electronic scale and a drain valve, the water storage container is fixed above the electronic scale through the support, and gas entering the water storage container is discharged from a guide pipe connected with the barrel cover and enters the flow control system.
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