阅读说明：本技术 一种多初始态燃料瞬态反应流场参数测试系统 (Multi-initial-state fuel transient reaction flow field parameter testing system ) 是由 荆琦 王丹 刘庆明 王志嵩 沈阳 刘长奇 于 2021-01-13 设计创作，主要内容包括：本发明提供的一种多初始态燃料瞬态反应流场参数测试系统,由气体预混系统、主体反应装置、成像系统和测控系统等四部分组成,其中主体反应装置为核心设备,将液体蒸汽注入管路、反应器、加热器、温度和压力传感器、清洁剂喷口和排污管等部件集成于一架可移动设备车中,用于完成爆炸性混合物的静置预混、辐射加热、火花点火、瞬态反应、清洁除污等过程；本系统可以实现初始温度范围300K～700K、初始压力0bar～5bar、爆炸极限内任意当量比的纯气体和液体蒸汽燃料的瞬态反应流场测试,为深入研究燃爆火焰传播机理提供原始数据,为能源利用、轮机工程、航天推进等领域提供技术支持。(The invention provides a multi-initial-state fuel transient reaction flow field parameter testing system which comprises a gas premixing system, a main body reaction device, an imaging system and a measuring and controlling system, wherein the main body reaction device is core equipment, and liquid steam injection pipelines, a reactor, a heater, temperature and pressure sensors, a cleaning agent nozzle, a drain pipe and other components are integrated in a movable equipment vehicle and are used for completing the processes of standing premixing, radiant heating, spark ignition, transient reaction, cleaning and decontamination and the like of explosive mixtures; the system can realize the transient reaction flow field test of pure gas and liquid steam fuel with the initial temperature range of 300K-700K, the initial pressure of 0 bar-5 bar and any equivalent ratio in the explosion limit, provide original data for deeply researching the propagation mechanism of the combustion and explosion flame, and provide technical support for the fields of energy utilization, turbine engineering, aerospace propulsion and the like.)

1. The system for testing the flow field parameters of the transient reaction of the multi-initial-state fuel is characterized by comprising a gas premixing system, a main body reaction device, an optical imaging system and a measurement and control system, wherein the gas premixing system comprises the following four parts:

the gas premixing system comprises a gas cylinder, a flowmeter, a gas mixing tank, a vacuum pump, a pressure gauge and other equipment;

the main reaction device comprises an evaporation pool (1), an evaporation pool heater (2), a flow regulating valve (3), a liquid storage chamber (4), an electromagnetic valve (5), air exhaust pipes (6) and (9), a pressure transmitter (7), an air inlet pipe (8), a reaction chamber heater (10), an end face flange (11), an observation window (12), a rail wheel (13), a chassis (14), a slide rail (15), a cleaning agent inlet pipeline (16), a mist spray nozzle (17), a reaction chamber (18), a pressure sensor (19), a blow-off pipe (20) and a pulley (22) of a thermocouple temperature sensor (21);

the liquid storage chamber (4) is filled with liquid fuel, the lower end of the liquid storage chamber is connected with the evaporation tank (1) through the flow regulating valve (3), and the outside of the evaporation tank is coated by the evaporation tank heater (2); the evaporation pool (1) is connected with the reaction chamber (18) through a series of connecting parts such as an electromagnetic valve (5) and the like, and the outside of the exhaust pipe (6) is connected with a vacuum pump; the reaction chamber (18) is of a sealed explosion-proof structure, two ends of the reaction chamber are sealed by end face flanges (11), an observation window (12) made of silicon-aluminum synthetic glass is embedded in each end face flange (11), the upper part of the reaction chamber (18) is connected with a pure gas pipeline besides a liquid fuel steam pipeline, and comprises an air inlet pipe (8) and an air exhaust pipe (9), and the upper end of the reaction chamber is connected with a pressure transmitter (7); the lower end of the reaction chamber (18) is provided with a pressure sensor (19) and a thermocouple temperature sensor (21); the reaction chamber heater (10) is coated outside the reaction chamber (18); the lower end of the reaction chamber heater is provided with four groups of rail wheels (13) which are arranged on the slide rail (15); the reaction device is supported by a lower end chassis (14), and four braking pulleys (22) are arranged at the lower end;

the evaporation pool heater (2) and the reaction chamber heater (10) are automatic temperature control heaters, one end of the temperature controller is connected with the heater, the other end of the temperature controller is connected with the thermocouple, the thermocouple is arranged in the container to display the temperature of the gas in the container, closed-loop feedback control is formed, the heater is internally provided with a high-efficiency metal heating wire, and the temperature of the gas in the container can reach 700K by utilizing radiation heating;

the upper end of the reaction chamber (18) is provided with three cleaning agent inlet pipelines (16), the connection part of the two is provided with a fog dispersion spray head (17), the cleaning agent can be uniformly sprayed to all parts of the reaction chamber, and pollutants are discharged by a lower end sewage discharge pipe (20);

the optical imaging system consists of a halogen lamp, a condenser, a slit, a plane mirror, a paraboloidal mirror, a light-cutting sheet, a high-speed camera and the like;

the measurement and control system consists of an igniter, an amplifier, a data collector, a synchronous trigger, a computer and the like.

2. The system for testing multiple initial state fuel transient reaction flow field parameters of claim 1, wherein: the gas mixing tank is of a horizontal columnar structure, and the length-diameter ratio L/D is more than or equal to 3; the ratio of the volume of the gas mixing tank to the volume of the reaction chamber is within the range of 0.3-0.5.

3. The bulk reactor of a multi-initial-state fuel transient reaction flow field parameter testing system of claim 1, wherein: the cleaning agent inlet line (16) can inject liquid cleaning agent or high-pressure air, wherein the pressure of the liquid cleaning agent is higher than 2bar, and the pressure of the high-pressure air is higher than 5 bar.

Technical Field

The invention belongs to the technical field of transient reaction flow field testing, and particularly relates to a multi-initial-state fuel transient reaction flow field parameter testing system.

Background

The combustion and explosion of explosive mixtures belong to transient reaction processes, and the measurement of flame propagation speed is the basis and difficulty of the current transient reaction flow field research. At present, flame propagation speed is mainly measured by a bunsen burner flame method, an opposite flame method, a closed combustion chamber method and the like. The Bunsen burner has a simple structure and is easy to operate, but because flame has a heating effect on airflow and the pipe wall has a cooling and radiating effect on the airflow close to the flame, the laminar flow velocity is different in different areas, and meanwhile, the measurement result error is larger due to the influence of negative stretching ratio; the opposite flame method avoids the problem of heat loss caused by heat dissipation of the spray pipe, but premixed gas sprayed from the spray nozzle is difficult to ensure to be vertical to a flame surface, so that the flame stretching phenomenon is generated, and the flame is difficult to maintain stability under the high-pressure condition, so that the method cannot be applied to measurement of the propagation speed of the high-pressure laminar flame. The closed combustion chamber method is characterized in that a sealed space with a certain volume is filled with gas, an electrode is adopted in the center of the combustion chamber for spark ignition, flame is ignited and spreads from the center to the periphery in a spherical shape, the moving track of a flame surface is recorded through an optical system, the flame propagation speed can be directly obtained, and the flame stretching rate, the Maxiten length and the relationship between the flame propagation speed and the Maxwell constant can be further deduced.

Existing experimental systems and platforms have a number of limitations and deficiencies: the quantitative injection of liquid fuel vapor cannot be realized; the transient reaction process in the high-temperature initial state cannot be researched; an automatic cleaning device is not needed, a cavity needs to be opened for cleaning after each experiment is finished, the operation is complex, and the sealing performance cannot be guaranteed; the synchronous temperature and pressure test is not carried out, so that the contribution to the research of the explosion flame propagation mechanism is small; all parts are distributed, so that the occupied space is large, and the integration level and the automation level are low.

Therefore, for the fuel mixture in the initial state of high temperature and high pressure, the accurate control of the equivalence ratio in the transient reaction in which the liquid fuel participates, and the synchronous test between the flame propagation process and the pressure wave and heat conduction, no effective test system exists at present.

Disclosure of Invention

In view of this, the present invention provides a multi-initial-state transient reaction flow field parameter testing system for fuel, which can measure the transient reaction flow field parameter measurement in multiple initial states (temperature range 300-700K, pressure range 0-5 bar, arbitrary equivalence ratio in explosion limit range).

A multi-initial-state fuel transient reaction flow field parameter testing system is composed of a gas premixing system, a main body reaction device, an optical imaging system and a measuring and controlling system, wherein the main body reaction device comprises a main body and a plurality of auxiliary bodies, the auxiliary bodies are arranged in the main body reaction device, the main body reaction device comprises a plurality of auxiliary bodies, and the auxiliary:

the gas premixing system comprises a gas cylinder, a flowmeter, a gas mixing tank, a vacuum pump, a pressure gauge and other equipment;

the main reaction device comprises an evaporation pool (1), an evaporation pool heater (2), a flow regulating valve (3), a liquid storage chamber (4), an electromagnetic valve (5), air exhaust pipes (6) and (9), a pressure transmitter (7), an air inlet pipe (8), a reaction chamber heater (10), an end face flange (11), an observation window (12), a rail wheel (13), a chassis (14), a slide rail (15), a cleaning agent inlet pipeline (16), a mist spray nozzle (17), a reaction chamber (18), a pressure sensor (19), a blow-off pipe (20) and a pulley (22) of a thermocouple temperature sensor (21);

the optical imaging system consists of a halogen lamp, a condenser, a slit, a plane mirror, a paraboloidal mirror, a light-cutting sheet, a high-speed camera and the like;

the measurement and control system consists of an igniter, an amplifier, a data collector, a synchronous trigger, a computer and the like, wherein the synchronous trigger can start high-speed photography, the igniter and the computer for data collection.

In the main body reaction device, a liquid storage chamber (4) is filled with liquid fuel, the lower end of the liquid storage chamber is connected with an evaporation pool (1) through a flow regulating valve (3), and the outside of the evaporation pool is coated by an evaporation pool heater (2); the evaporation pool (1) is connected with the reaction chamber (18) through a series of connecting parts such as an electromagnetic valve (5), and the outside of the air exhaust pipes (6) and (9) is connected with a vacuum pump; the reaction chamber (18) is of a sealed explosion-proof structure, two ends of the reaction chamber are sealed by end face flanges (11), an observation window (12) made of silicon-aluminum synthetic glass is embedded in each end face flange (11), the upper part of the reaction chamber (18) is connected with a pure gas pipeline besides a liquid fuel steam pipeline, and comprises an air inlet pipe (8) and an air exhaust pipe (9), and the upper end of the reaction chamber is connected with a pressure transmitter (7); the lower end of the reaction chamber (18) is provided with a pressure sensor (19) and a thermocouple temperature sensor (21); the reaction chamber (18) is externally coated with a reaction chamber heater (10), and the lower end of the reaction chamber heater is provided with four groups of rail wheels (13) which are arranged on a sliding rail (15); the whole reaction device is supported by a chassis (14), and four braking pulleys (22) are arranged at the lower end of the reaction device.

The evaporation pool heater (2) and the reaction chamber heater (10) are automatic temperature control heaters, one end of the temperature controller is connected with the heater, the other end of the temperature controller is connected with the thermocouple, the thermocouple is arranged in the container to display the temperature of the gas in the container, closed-loop feedback control is formed, the heater is internally provided with a high-efficiency metal heating wire, and the temperature of the gas in the container can reach 700K by utilizing radiation heating.

Three cleaning agent inlet pipelines (16) are arranged at the upper end of the reaction chamber (18), a fog dispersion spray head (17) is arranged at the joint of the three cleaning agent inlet pipelines, high-pressure cleaning agents can be uniformly sprayed to all parts of the reaction chamber, and pollutants are discharged through a lower end sewage discharge pipe (20).

Preferably, the detergent inlet line (16) may inject liquid detergent or high pressure air, wherein the pressure of the liquid detergent is higher than 2bar, and the pressure of the high pressure air is higher than 5 bar.

Preferably, the gas mixing tank is of a horizontal columnar structure, and the length-diameter ratio L/D is more than or equal to 3; the ratio of the volume of the gas mixing tank to the volume of the reaction chamber is within the range of 0.3-0.5.

The invention has the following beneficial effects:

the multi-initial-state fuel transient reaction flow field parameter testing system provided by the invention can realize the transient reaction process test of pure gas and liquid steam fuel with an initial temperature range of 300K-700K, an initial pressure of 0 bar-5 bar and any equivalence ratio within the fuel explosion limit; the quantitative input of liquid fuel vapor can be realized; the device can automatically clean and discharge pollution after each experiment is finished, is simple to operate and ensures the sealing property; the synchronous temperature and pressure test is carried out, so that the characteristic parameters of the blasting temperature, the blasting pressure, the laminar flame speed, the laminar flame stretching rate, the Maxim length, the flame instability critical condition and the like can be obtained simultaneously, and original data are provided for further researching the propagation mechanism of the blasting flame; the system integration level and the automation level are high. The invention can be used for transient reaction process test of most fuels with the boiling point lower than 700K to obtain basic physical property parameters, and provides technical support for the fields of energy utilization, turbine engineering, aerospace propulsion and the like.

Drawings

FIG. 1 is a schematic view of a multi-initial-state fuel transient reaction flow field parameter testing system according to the present invention;

FIGS. 2 and 3 are schematic structural diagrams of a main reaction device of a multi-initial-state fuel transient reaction flow field parameter testing system according to the present invention;

FIG. 4 is a graph showing the analysis of the test results of the first embodiment of the present invention (ether/oxygen mixture, initial state: P)₀＝0bar，T₀400K, fuel equivalence ratio)；

FIG. 5 is a raw graph of the test results (acetylene/hydrogen/air mixture) for example two of the present invention;

wherein: 1-evaporation pool, 2-evaporation pool heater, 3-flow regulating valve, 4-liquid storage chamber, 5-electromagnetic valve, 6-air extraction pipe (1), 7-pressure transmitter, 8-air inlet pipe, 9-air extraction pipe (2), 10-reaction chamber heater, 11-end face flange, 12-observation window, 13-rail wheel, 14-chassis, 15-slide rail, 16-cleaning agent inlet pipeline, 17-fog dispersion nozzle, 18-reaction chamber, 19-pressure sensor, 20-blow-off pipe, 21-thermocouple temperature sensor and 22-pulley.

Detailed Description

The invention is described in detail below by way of example with reference to the accompanying drawings.

The invention mainly solves the technical problem of providing a multi-initial-state fuel transient reaction flow field parameter testing system which can test the burning explosion reaction flow field parameters of gas and liquid fuel in initial states of different initial proportions, different initial temperatures, different initial pressures and the like, wherein the burning explosion reaction flow field parameters comprise characteristic parameters such as burning explosion temperature, burning explosion pressure, laminar flame speed, laminar flame stretching rate, Maxiten length, flame instability critical conditions and the like.

The multi-initial-state fuel transient reaction flow field parameter testing system provided by the invention is shown in fig. 1, and mainly comprises four parts, namely a gas premixing system, a main body reaction device, an optical imaging system and a measurement and control system.

The gas premixing system is used for preparing a premixed explosive gas mixture with a certain equivalence ratio and comprises a gas cylinder, a flowmeter, a gas mixing tank, a vacuum pump, a pressure gauge and the like, wherein different gas fuels and oxidants enter the gas mixing tank from the gas cylinder through the flowmeter, and the flowmeter is used for accurately controlling the gas flow; before gas injection, a vacuum pump is used for vacuumizing treatment, so that impurity-free gas in a gas mixing tank and a pipeline is ensured; according to the law of dalton partial pressure, the gas injection amount is controlled by the reading of a pressure gauge.

The main body reaction device is a core device of the invention and completes the processes of standing premixing, radiant heating, spark ignition, transient reaction, cleaning and decontamination and the like of explosive mixtures. As shown in fig. 2 and 3, the liquid storage chamber (4) is filled with liquid fuel (such as ethanol) and ensures good sealing, the lower end of the liquid storage chamber is connected with the evaporation pool (1) through the flow regulating valve (3), the outside of the evaporation pool is covered by the evaporation pool heater (2), and the liquid flowing into the evaporation pool can be evaporated into a gaseous state; the evaporation pool (1) is connected with the reaction chamber (18) through a series of connecting parts such as an electromagnetic valve (5), the outside of the exhaust pipe (6) is connected with a vacuum pump, and the inside of the parts can be vacuumized. The reaction chamber (18) is of a sealed explosion-proof structure, two ends of the reaction chamber are sealed by end face flanges (11), an observation window (12) made of silicon-aluminum synthetic glass is embedded in each end face flange, the upper part of the reaction chamber (18) is connected with a liquid fuel steam pipeline and a pure gas pipeline besides the liquid fuel steam pipeline, the reaction chamber comprises an air inlet pipe (8) and an air exhaust pipe (9), the upper end of the reaction chamber is connected with a pressure transmitter (7), and reactant preparation is completed according to the displayed numerical value of the reaction chamber; the lower end of the reaction chamber (18) is provided with a pressure sensor (19) and a thermocouple temperature sensor (21); in order to test the explosion parameters of the high-temperature initial state, a reaction chamber heater (10) is coated outside the reaction chamber, and substances in the reaction chamber can reach higher initial temperature through radiant heating; in order to facilitate the repair and cleaning of equipment, four groups of rail wheels (13) are arranged at the lower end of the reaction chamber heater (10) and are arranged on a sliding rail (15) to realize free sliding. The whole reaction device is supported by a chassis (14), and four braking pulleys (22) are arranged at the lower end of the whole reaction device and can move the whole reaction device.

The evaporation pool heater (2) and the reaction chamber heater (10) are automatic temperature control heaters, one end of the temperature controller is connected with the heater, the other end of the temperature controller is connected with the thermocouple, the thermocouple is arranged in the container to display the internal gas temperature, closed-loop feedback control is formed, and the high-efficiency metal heating wires are arranged in the heater and can quickly heat the gas to a preset temperature.

As the explosive mixed fuel often generates carbon-containing liquid substances, the inner wall and an observation window of the reaction chamber can be polluted after the experiment is completed each time, and the subsequent experiment is influenced, three cleaning agent inlet pipelines (16) are arranged at the upper end of the reaction chamber (18), the connection part of the three cleaning agent inlet pipelines and the observation window is provided with the fog-dispersing spray head (17), the high-pressure cleaning agent can be uniformly sprayed to all parts of the reaction chamber, and the cleaned pollutants are discharged by the lower end discharge pipe (20).

The reaction chamber is made of stainless steel materials so as to achieve an explosion-proof effect, and the reliable grounding of the system is guaranteed in the using process.

The liquid cleaning agent or high-pressure air can be sprayed into the cleaning agent inlet pipeline (16), wherein the pressure of the liquid cleaning agent is higher than 2bar, and the pressure of the high-pressure air is higher than 5 bar.

The gas mixing tank is of a horizontal columnar structure, and the length-diameter ratio L/D is more than or equal to 3; the ratio of the volume of the gas mixing tank to the volume of the reaction chamber is within the range of 0.3-0.5.

The optical imaging system can convert the density gradient of the flow field into the brightness gradient of the image to obtain clear flame information and comprises a halogen lamp, a condenser, a slit, a plane mirror, a paraboloidal mirror, a light-cutting sheet, a high-speed camera and the like.

The measurement and control system is used for realizing synchronous triggering and data collection and sorting among all parts, and consists of an igniter, an amplifier, a data collector, a synchronous trigger, a computer and the like, wherein the synchronous trigger can start high-speed photography, the igniter and the data collection of a computer end at the same time.

The present invention provides a method for applying a multi-initial-state fuel transient reaction flow field parameter testing system.

The first embodiment is as follows: ether/oxygen mixture explosive flow field testing

The invention is applied to the ether/oxygen mixture explosion flame test, and the initial state is as follows: p₀＝1bar，T₀400K, fuel equivalence ratioThe method comprises the following steps:

1. preparation of the experiment: calculating the initial state according to the Dalton partial pressure law to obtain the ether partial pressure P₁Oxygen partial pressure of P₂(P₀＝P₁+P₂)，T₀400K; erecting an experimental device, checking the reliability of each system, and adjusting the optical path of the optical imaging system; and (3) starting an evaporation pool heater (2) and a reaction chamber heater (10), presetting the temperature to 400K, reaching heat supply balance, filling diethyl ether in a liquid storage chamber (4), checking the air tightness of the system, and vacuumizing the whole system (the index of a pressure transmitter is zero, and the index is gauge pressure).

2. Gas distribution: opening the flow regulating valve (3), enabling all the diethyl ether to flow into the evaporation pool, and fully evaporating until heat balance is achieved; the computer end opens the electromagnetic valve (5) to make the ether steam enter the reaction chamber (18) until the reading of the pressure transmitter (7) reaches P₁Closing the electromagnetic valve; opening an oxygen cylinder to make oxygen directly enter the reaction chamber, regulating the flow through a flowmeter until the reading of the pressure transmitter reaches P₀And closing all air inlet valves, standing, and waiting until the temperature in the reaction chamber is stabilized to 400K.

3. And (3) ignition test: a synchronous trigger is initiated, spark ignited and data and images recorded.

4. Cleaning: after the experiment is finished, the cleaning agent inlet pipeline (16) is externally connected with a high-pressure cleaning agent or high-pressure clean air to wash the reactor (18), and pollutants are discharged from a lower end sewage discharge pipe (20).

5. And (4) analyzing results: the data obtained in this example are shown in fig. 4, and the explosion temperature, explosion pressure, laminar flame speed, laminar flame elongation, max's length, critical conditions of flame instability, flame propagation process, etc. can be analyzed.

Example two: acetylene/hydrogen/air mixture explosive flow field testing

The invention is applied to the acetylene/hydrogen/air mixture explosion flame test, and the initial state is as follows: p₀＝0.2～2.0bar，T₀300-600K, fuel equivalence ratioThe volume ratio of acetylene to hydrogen, f, is 1, and the method comprises the following steps:

1. preparation of the experiment: calculating the initial state according to the Dalton partial pressure law, wherein the acetylene partial pressure is P₁Partial pressure of hydrogen being P₂Air partial pressure of P₃(P₀＝P₁+P₂+P₃)，T₀300-600K; erecting an experimental device, checking the reliability of each system, and adjusting the optical path of the optical imaging system; starting a reaction chamber heater (10), wherein the preset temperature is the initial temperature T of the experiment₀And the heat supply balance is achieved, all valves for liquid steam to enter the reaction chamber are closed, the air tightness of the system is checked, and the whole system is pumped to vacuum.

2. Gas distribution: closing the air inlet pipe (8), opening the acetylene gas cylinder, entering the gas mixing tank through the flow meter, and counting by the pressure gauge above the gas mixing tank to 5P₁Closing the acetylene cylinder, vacuumizing the pipeline, and filling hydrogen and air into the gas mixing tank until the pressure gauge shows 5 points (P)₁+P₂) And 5P₀(ii) a After the gas mixing tank is kept still for 30min, the gas inlet pipeline (8) is opened, the mixed gas enters the reaction chamber (18) until the reading of the pressure transmitter (7) reaches P₀Closing all air inlet valves, standing, and allowing the temperature in the reaction chamber to stabilize to a preset initial temperature T₀。

3. And (3) ignition test: a synchronous trigger is initiated, spark ignited and data and images recorded.

4. Cleaning: after the experiment is finished, the cleaning agent inlet pipeline (16) is externally connected with a high-pressure cleaning agent or high-pressure clean air to wash the reactor (18), and pollutants are discharged from a lower end sewage discharge pipe (20).

5. And (4) analyzing results: the resulting image obtained in this example is shown in fig. 5, and the laminar flame speed, the laminar flame elongation, the marxtan length, the critical condition of flame instability, and the influence of the initial pressure and temperature on the flame propagation process, etc. can be analyzed.

In summary, the above is only a preferred embodiment of the present invention, and is not intended to limit the scope of the present invention. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.