阅读说明：本技术 研究碳氢燃料液滴在微小尺度热壁面蒸发结焦的实验装置及其实验方法 (Experimental device and experimental method for researching evaporation and coking of hydrocarbon fuel liquid drops on micro-scale hot wall surface ) 是由 周伟星 龙琳 昝浩 于 2021-07-23 设计创作，主要内容包括：本发明提供了一种碳氢燃料液滴在微小尺度热壁面蒸发结焦的实验装置,包括实验腔体组件、加热系统、高压电系统和供气系统,实验腔体组件提供密闭环境以及满足液滴蒸发的实验和观测条件,加热系统提供微小壁面的加热以及为实验腔体环境提供稳定辐射热源,高压电系统为液滴在高压电充电情况下的蒸发结焦提供实验能力,供气系统则模拟微小壁面喷嘴孔吹除以及对实验腔体供气、抽气的作用。本发明解决了目前还没有一种专门及系统的用于碳氢燃料液滴在微小尺度热壁面蒸发结焦的实验装置的问题,本发明具有多种综合实验环境、变量参数多,以及结构简单、易于实现及更换零部件简单等优点,同时工艺上也易于实现。(The invention provides an experimental device for evaporation coking of hydrocarbon fuel droplets on a micro-scale hot wall surface, which comprises an experimental cavity assembly, a heating system, a high-voltage system and a gas supply system, wherein the experimental cavity assembly provides a closed environment and meets experimental and observation conditions of droplet evaporation, the heating system provides heating of the micro wall surface and provides a stable radiation heat source for the experimental cavity environment, the high-voltage system provides experimental capability for evaporation coking of the droplets under the high-voltage charging condition, and the gas supply system simulates the blowing-off of the micro nozzle holes and the effects of gas supply and air exhaust of the experimental cavity. The invention solves the problem that no special and systematic experimental device for evaporation and coking of hydrocarbon fuel liquid drops on the micro-scale hot wall surface exists at present, has the advantages of various comprehensive experimental environments, more variable parameters, simple structure, easy realization, simple part replacement and the like, and is easy to realize in process.)

1. The utility model provides an experimental apparatus for research hydrocarbon fuel liquid drop is at tiny yardstick hot wall evaporation coking, a serial communication port, including experiment cavity subassembly, a heating system, high-voltage electricity system and gas supply system, wherein, experiment cavity subassembly provides airtight environment and satisfies the experiment observation condition that the liquid drop evaporates, heating system provides the heating of tiny wall and provides stable radiant heat source for experiment cavity environment, high-voltage electricity system provides experimental ability for the evaporation coking of liquid drop under the high-voltage electricity charging condition, gas supply system then simulates the effect that tiny wall nozzle hole blows off and to experiment cavity air feed, bleed.

2. The experimental device for researching hydrocarbon fuel liquid drop evaporation and coking on the micro-scale hot wall surface as claimed in claim 1, wherein the experimental cavity assembly comprises an experimental cavity body (1), an experimental cavity bottom cover (4) and a hot wall surface table (7), the experimental cavity body (1) is installed on the experimental cavity bottom cover (4), and the hot wall surface table (7) is fixed in the experimental cavity body (1).

3. The experimental device for researching the evaporation and coking of the hydrocarbon fuel liquid drops on the micro-scale hot wall surface as claimed in claim 2, wherein the experimental cavity body (1) is in threaded connection with the experimental cavity bottom cover (4), and the connection end surface adopts a high-temperature end surface sealing mode.

4. The experimental device for researching the evaporation and coking of the hydrocarbon fuel liquid drops on the micro-scale hot wall surface according to claim 2, wherein the hot wall surface table (7) is fixed in the experimental cavity body (1) through hot wall surface table pillars (8) on two sides, and the hot wall surface table (7) is connected with the hot wall surface table pillars (8) in a threaded manner.

5. The experimental device for researching hydrocarbon fuel liquid drop evaporation and coking on the micro-scale hot wall surface as claimed in claim 1, wherein the heating system comprises a table top heating plate (6) and a cavity heating plate (2), the table top heating plate (6) is fixed on the experimental cavity bottom cover (4) and is located right below the hot wall surface table (7), and the cavity heating plate (2) is fixed on the inner wall of the experimental cavity (1).

6. The experimental device for researching the evaporation and coking of the hydrocarbon fuel liquid drops on the micro-scale hot wall surface according to claim 1, wherein a high-voltage power supply output terminal of the high-voltage power system is connected with a hot-wall table top (7), the hot-wall table top (7) is insulated from an experimental cavity body (1) and a heating system, the high-voltage power supplies different voltage intensities and forms, and the experimental cavity bottom cover (4) is connected with a ground electrode.

7. The experimental device for researching hydrocarbon fuel liquid drop evaporation and coking on the micro-scale hot wall surface as claimed in claim 1, wherein the gas supply system comprises a vent pipe (9), the telescopic vent pipe (9) is connected to the experimental cavity bottom cover (4), and after the table top heating plate (6) is detached, the vent pipe (9) can be connected to the hot wall table top (7).

8. The experimental device for researching the evaporation and coking of the hydrocarbon fuel liquid drops on the micro-scale hot wall surface according to claim 1, wherein a certain gap is reserved between the table top heating plate (6) and the hot wall table top (7), and the hot wall table top (7) is heated by adopting a radiation heating mode.

9. The experimental device for researching evaporation and coking of hydrocarbon fuel liquid drops on the micro-scale hot wall surface according to claim 1, wherein windows are formed in the top and the front and back surfaces of the experimental cavity body (1), the windows are sealed and attached by high-temperature-resistant transparent materials, and then compression sealing is performed by bolts and compression covers.

10. An experimental method for researching experimental device for hydrocarbon fuel liquid drop evaporation coking on micro-scale hot wall surface according to any one of claims 1 to 9, is characterized by comprising the following steps:

(1) according to different experimental requirements, different hot wall table tops (7) are installed, and a table top heating plate (6) is connected to an experimental cavity bottom cover (4) through a second high-temperature insulating bolt (5);

(2) connecting the cavity heating plate (2) to the experimental cavity (1) through a first high-temperature insulating bolt (3), then installing a single-plane hot wall table top (7) on the experimental cavity (1) through a hot wall table support (8), and screwing the hot wall table support (8) through a nut on the experimental cavity (1);

(3) installing quartz glass on the experimental cavity body (1), sealing and screwing, and sealing and screwing the experimental cavity body (1) and the experimental cavity bottom cover (4) by using bolts;

(4) after the pressure and temperature sensors are tested to be correct, the tightness is checked, different gases are introduced according to the requirements, the tightness is tested, the pressure is kept for 24 hours in a closed mode under the experimental pressure which is more than 2 times, and the pressure change is not more than 1%;

(5) the interior of the cavity is subjected to radiation heating by using the cavity heating plate (2) through a temperature control system, so that the temperature in the cavity is stable, and the hot wall table top (7) is heated by using the table top heating plate (6) to reach the specified temperature and be stably maintained;

(6) debugging observation equipment, carrying out a liquid drop evaporation reaction experiment after the observation equipment is debugged, quickly dropping liquid drops on a hot wall table top (7) through a fuel oil feeding system, testing the change of a state, and carrying out an offline microscopic test on the coking wall surface after the liquid drops are evaporated and completely react;

(7) if the experiment charges the liquid drops through high voltage, the step 6 is carried out after the high-voltage system and the corresponding test system are debugged in the step 5, and the liquid drops need to be electrified before the step 6 is carried out;

(8) if the nozzle opening coking is researched, the plane table top in the step 1 needs to be changed into the table top with the nozzle opening, the step is the same as the step 1-7, or firstly dripping liquid drops in the step 5 and then carrying out the subsequent steps, if the nozzle opening coking with blowing is researched, the liquid drops need to be dripped into the nozzle in advance in the step 1, then the step 1-3 is carried out, the blowing step needs to be added in the step 3, and then the step 4-6 is carried out;

(9) and different table-board materials and different hydrocarbon fuels are replaced according to the requirements to carry out experiments.

Technical Field

The invention relates to an experimental device and an experimental method for researching evaporation and coking of hydrocarbon fuel liquid drops on a micro-scale hot wall surface, and belongs to the technical field of energy and material chemistry of metal catalytic hydrocarbon fuel.

Background

At present, the commonly used engines using hydrocarbon as fuel and the like all utilize chemical energy released by fuel combustion to be converted into mechanical energy for human use. In order to facilitate carrying and storage, a general household fuel is in a liquid state at normal temperature and pressure, and in order to improve combustion efficiency, the fuel is generally atomized by using a nozzle so as to be in contact with an oxidant as sufficiently as possible. In the combustion process, a high-temperature and high-pressure working environment is easily generated, the harsh environment necessarily involves chemical reaction between a hot wall surface and fuel oil, and the hot wall surface or a nozzle and other parts are easy to generate coke bodies to damage the normal operation of an engine.

Under the working conditions of engine stop and the like, because the flame of the combustion chamber is extinguished, the waste heat on the wall surface of the combustion chamber can still transfer heat outwards in a heat radiation mode. In this case, the fuel adheres to the metal wall in some way to produce evaporation, cracking or oxidation reactions, and the oxidized coke is also a product of chemical reactions, thus avoiding the problem that the coking products can significantly harm the performance and safety of the engine due to the accumulation of time.

The fuel adheres to the metal wall mainly in two forms, the first is that the fuel atomized by the nozzle is not completely evaporated in the gas and adheres to the hot wall of the combustion chamber, and the second is that the nozzle orifice of the nozzle is usually very small, so the effects of capillary force and the like cannot be ignored, and the fuel adheres to the nozzle passage and the nozzle orifice. Both of these forms involve evaporation of the fuel and chemical reaction between the wall material and the fuel.

In order to solve the problem that fuel adheres to a hot wall surface, for example, after an aircraft engine is shut down, a nozzle is blown off by using nitrogen; the coking reaction is inhibited by adopting a coating mode on the wall surface of the combustion chamber or the surface of the nozzle; the problems of coking of the wall surface of the combustion chamber and coking and blockage of the nozzle still exist by improving the atomization efficiency of the nozzle and other technologies, so that the comprehensive research of a system is still needed, particularly the research of the evaporation of liquid drops on the hot wall surfaces in different forms and the starting and development processes of coking.

The electric field has the characteristics of continuous adjustability and easy control, and the cost is lower, so the electric field is an important choice for solving the coking problem. The chemical reaction path is changed in the coking process due to the action of the electric field, meanwhile, the charge distribution of the liquid drops on the wall surface is changed due to the action of the electric field, the evaporation characteristic of the liquid drops is changed due to the increased charge force, and the aim of reducing coking is fulfilled. Therefore, the introduction of an electric field is an important means for improving or solving the coking problem.

Disclosure of Invention

The invention aims to solve the problem that no special and systematic experimental device for evaporation and coking of hydrocarbon fuel liquid drops on a micro-scale hot wall surface exists at present, provides an experimental device and an experimental method for researching the evaporation and coking of the hydrocarbon fuel liquid drops on the micro-scale hot wall surface, and simulates the evaporation of the hot wall surface to the liquid drops and the catalytic chemical reaction process of the fuel.

The invention provides an experimental device for researching evaporation coking of hydrocarbon fuel liquid drops on a micro-scale hot wall surface, which comprises an experimental cavity assembly, a heating system, a high-voltage system and a gas supply system, wherein the experimental cavity assembly provides a closed environment and meets experimental observation conditions of liquid drop evaporation, the heating system provides heating of the micro wall surface and provides a stable radiation heat source for the experimental cavity environment, the high-voltage system provides experimental capacity for evaporation coking of the liquid drops under the high-voltage charging condition, and the gas supply system simulates the blowing-off of the wall surface of a micro nozzle hole and the effects of gas supply and air exhaust of the experimental cavity.

Preferably, the experiment cavity assembly comprises an experiment cavity body, an experiment cavity bottom cover, a hot wall surface table and a hot wall surface table supporting column, the experiment cavity body is installed on the experiment cavity bottom cover, and the hot wall surface table is fixed in the experiment cavity body.

Preferably, the experimental cavity body is in threaded connection with the experimental cavity bottom cover, and the connection end face adopts a high-temperature end face sealing mode.

Preferably, the hot wall surface table is fixed in the experiment cavity through hot wall surface table supporting columns on two sides, and the hot wall surface table is connected with the hot wall surface table supporting columns in a threaded mode.

Preferably, heating system includes mesa hot plate and cavity hot plate, the mesa hot plate is fixed on the experiment chamber bottom cover, is located hot wall platform under, the cavity hot plate is fixed on the inner wall of experiment chamber cavity.

Preferably, the high-voltage system is connected with the hot wall table top, the hot wall table top is insulated from the experimental cavity and the heating system, the high-voltage power provides different voltage intensities and forms, and the experimental cavity bottom cover is connected with the grounding electrode.

Preferably, the gas supply system comprises a vent pipe, the telescopic vent pipe is connected to the bottom cover of the experimental cavity, and the vent pipe can be connected to the hot wall table top after the heating plate of the table top is detached.

Preferably, the hot wall table top is divided into two types, one type is a circular table top with a threaded hole, and nozzles made of different materials and with different apertures can be installed in the threaded hole; the other is that one surface is a plane, the other surface calculates the geometric dimension of the surface with the irregular shape according to different radiation powers of the table top heating plate, and liquid drops are placed on the plane.

Preferably, a certain gap is left between the heating plate of the table top and the table top of the hot wall, and the table top of the hot wall is heated by adopting a radiation heating mode.

Preferably, windows are arranged on the top and the front and back of the experimental cavity body, the windows are sealed and attached by high-temperature-resistant transparent materials, and then the windows are compressed and sealed by nuts and compression covers.

An experimental method of an experimental device for researching evaporation and coking of hydrocarbon fuel liquid drops on a micro-scale hot wall surface specifically comprises the following steps:

1. according to different experimental requirements, installing different hot wall table tops, for example, researching the reaction between droplet evaporation and stainless steel hot wall surface materials under the condition of no high voltage, and firstly connecting a table top heating plate to a bottom cover of an experimental cavity through a second high-temperature insulating bolt;

2. connecting the cavity heating plate to the cavity of the experimental cavity through a first high-temperature insulating bolt, then installing the single-plane hot wall table top onto the cavity of the experimental cavity through a hot wall table support, and screwing the hot wall table support through a nut in the cavity of the experimental cavity;

3. installing quartz glass on the experimental cavity body, sealing and screwing, and sealing and screwing the experimental cavity body and the experimental cavity bottom cover by using bolts;

4. testing the tightness after the pressure, temperature and other sensors are tested to be correct, introducing different gases according to the requirements, such as anhydrous air, testing the tightness, and keeping the pressure under the experimental pressure of more than 2 times for 24 hours in a closed manner, wherein the pressure change is not more than 1%;

5. the interior of the cavity is subjected to radiation heating by using the cavity heating plate through the temperature control system, so that the temperature in the cavity is stable, and the hot wall table top is heated by using the table top heating plate to reach the specified temperature and be stably maintained;

6. debugging observation equipment, carrying out a liquid drop evaporation reaction experiment after the observation equipment is debugged, quickly dropping liquid drops on a hot wall table board through a fuel oil feeding system, testing the change of a state, and carrying out an offline microscopic test on a coked wall surface after the liquid drops are evaporated and completely reacted;

7. if the experiment charges the liquid drops through high voltage, step 6 is carried out after the high-voltage system and the corresponding test system are debugged in step 5, and power needs to be firstly switched on before step 6 is carried out;

8. if the nozzle opening coking is researched, the plane table top in the step 1 needs to be changed into the table top with the nozzle opening, the step is the same as the step 1-7, or firstly dripping liquid drops in the step 5 and then carrying out the subsequent steps, if the nozzle opening coking with blowing is researched, the liquid drops need to be dripped into the nozzle in advance in the step 1, then the step 1-3 is carried out, the blowing step needs to be added in the step 3, and then the step 4-6 is carried out;

9. different materials of the table top and different hydrocarbon fuels are replaced according to the requirements to carry out experiments.

The experimental device and the experimental method for researching the evaporation and coking of the hydrocarbon fuel liquid drops on the micro-scale hot wall surface have the beneficial effects that:

1. the experimental device for researching the evaporation and coking of the hydrocarbon fuel liquid drops on the micro-scale hot wall surface provided by the invention is used for experimental simulation test of the evaporation of the hot wall surface to the liquid drops and the catalytic chemical reaction process to the fuel, has the advantages of various comprehensive experimental environments, more variable parameters and the like, and makes up for the lack of the experimental device for the multi-factor evaporation and coking of the hydrocarbon fuel liquid drops on the micro-scale hot wall surface.

2. Particularly, the experimental device can provide different temperatures and pressures, different gas components, different materials and different types of fuel oil to carry out systematic experiments, can meet the requirement of testing in online visual measurement forms such as a microscopic zooming high-speed camera, and the like, simultaneously simulates the evaporation of liquid drops under the conditions of blowing-off working conditions and increased electric fields and the catalytic chemical reaction process of the fuel, and provides experimental data for basic research.

3. The invention has the advantages of simple structure, easy realization, simple replacement of parts and the like, and is easy to realize in process.

Drawings

The accompanying drawings, which are incorporated in and constitute a part of this application, illustrate embodiments of the invention and, together with the description, serve to explain the invention and not to limit the invention.

In the drawings:

FIG. 1 is a schematic perspective view of an experimental apparatus for studying evaporation and coking of hydrocarbon fuel droplets on a micro-scale hot wall surface according to the present invention;

FIG. 2 is a perspective schematic view of an experimental apparatus for studying evaporation and coking of hydrocarbon fuel droplets on a micro-scale hot wall surface according to the present invention;

FIG. 3 is a perspective view of a heating plate for heating the hot deck by radiation;

FIG. 4 is a schematic diagram of a half-section structure of an experimental device for studying evaporation and coking of hydrocarbon fuel droplets on a micro-scale hot wall surface;

FIG. 5 is a schematic structural diagram of a first hot wall mesa;

FIG. 6 is a schematic structural view of a second hot wall mesa;

the device comprises a test cavity, a cavity heating plate, a high-temperature insulating bolt, a test cavity bottom cover, a test cavity top cover, a test cavity bottom cover, a test cavity heating plate, a test cavity bottom cover, a test cavity heating plate, a test cavity bottom cover, a second high-temperature insulating bolt, a high-insulating bolt, a high-insulating bolt, 6-table top heating plate, 6-hot insulating bolts, 6-table top heating plate, a hot-hot wall table top heating plate, 6-hot wall table top, a hot wall table, a 6-hot wall table, a hot wall table top, a hot wall table, a 6-hot wall table, a 6-hot wall table, a hot wall table support, a hot wall table, a hot wall.

Detailed Description

The following detailed description of embodiments of the invention is provided in conjunction with the appended drawings:

the first embodiment is as follows: the present embodiment is explained with reference to fig. 1 to 6. The experimental device for researching evaporation and coking of hydrocarbon fuel droplets on the micro-scale hot wall surface comprises an experimental cavity assembly, a heating system, a high-voltage system and a gas supply system, wherein the experimental cavity assembly provides a closed environment and meets experimental observation conditions of droplet evaporation, for example, different pressures and gas types can be provided; the heating system provides heating of the tiny wall surface and a stable radiation heat source for the experiment cavity environment, and the heating system is accurately controlled through the temperature control system; the high-voltage system provides experimental capacity for evaporation and coking of liquid drops under the high-voltage charging condition, the voltage is controlled through the high-voltage system, and an oscilloscope is used for measurement; the air supply system simulates the blowing of the nozzle holes on the tiny wall surface and the effects of air supply and air exhaust on the experimental cavity, the main structure is shown in the perspective view of figure 2, and a telescopic vent pipe 9 is arranged below the experimental cavity bottom cover 4.

The experiment cavity assembly comprises an experiment cavity body 1, an experiment cavity bottom cover 4, a hot wall surface table 7 and a hot wall surface table supporting column 8, wherein the experiment cavity body 1 is installed on the experiment cavity bottom cover 4, and the hot wall surface table 7 is fixed in the experiment cavity body 1. The hot wall surface table 7 is fixed in the experimental cavity body 1 through hot wall surface table supporting columns 8 on two sides, and the hot wall surface table 7 is connected with the hot wall surface table supporting columns 8 in a threaded mode.

The hot wall surface table pillar 8 is made of high-temperature insulating materials, such as ceramic bolts, the hot wall surface table pillar 8 is symmetrically arranged on two sides of the hot wall surface table 7, the other end of the hot wall surface table pillar is in nut compression sealing connection with the experimental cavity upper cover 1, and nuts are arranged outside the experimental cavity upper cover 1;

the experimental cavity body 1 and the experimental cavity bottom cover 4 are in threaded connection, and the connection end face adopts a high-temperature end face sealing mode.

The heating system comprises a table top heating plate 6 and a cavity heating plate 2, the table top heating plate 6 is fixed on the experimental cavity bottom cover 4 and located under the hot wall table 7, and the cavity heating plate 2 is fixed on the inner wall of the experimental cavity 1. The table top heating plate 6 is connected with the experiment cavity bottom cover 4 through high-temperature insulating bolts 5, the number of the high-temperature insulating bolts is more than or equal to 3, or a single insulating bolt is used in the middle of the table top heating plate. The cavity heating plate 2 is symmetrically arranged on the left side and the right side of the experimental cavity bottom cover 4 without a window, the number of high-temperature insulating bolts used on each side is more than or equal to 3, or a single insulating bolt is used in the middle of the table top heating plate.

The high-voltage system is connected with the hot wall table top 7, the hot wall table top 7 is insulated from the experimental cavity 1 and the heating system, the high voltage provides different voltage intensities and forms, and the experimental cavity bottom cover 4 is connected with the grounding electrode.

The gas supply system comprises a vent pipe 9, the telescopic vent pipe 9 is connected to the experimental cavity bottom cover 4, and after the table top heating plate 6 is detached, the vent pipe 9 can be connected to the hot wall table top 7.

The hot wall table top 7 is divided into two types, one type is a round table top with a threaded hole, and nozzles made of different materials and with different apertures can be arranged in the threaded hole; the other is that one surface is a plane, the other surface calculates the geometric dimension of the surface with the irregular shape according to different radiation powers of the table top heating plate 6, and liquid drops are placed on the plane.

A certain gap is left between the table top heating plate 6 and the hot wall table top 7, and the hot wall table top 7 is heated by adopting a radiation heating mode.

The top and the front and back of the experimental cavity body 1 are provided with windows, the windows are sealed and attached by high-temperature-resistant transparent materials, and then the windows are compressed and sealed by nuts and compression covers.

The following is explained in detail with reference to the drawings:

specifically, with reference to fig. 4, an experimental apparatus for studying evaporation and coking of hydrocarbon fuel droplets on a micro-scale hot wall surface is characterized in that: the whole square structure of three-side windowing is mainly connected by bolts, the three-side windowing mainly considers that a microscopic zooming camera can be adopted from the upper side to tell the measurement, and the side surface is convenient for experimental observation or detection of other optical equipment. The experimental cavity assembly comprises an experimental cavity body 1, an experimental cavity bottom cover 4, a hot wall surface table 7 and a hot wall surface table supporting column 8, wherein the experimental cavity body 1 and the experimental cavity bottom cover 4 are in threaded connection, the connection end surface adopts a high-temperature end surface sealing mode, and an end surface sealing material adopts a high-temperature resistant material, such as a graphite gasket. The hot wall surface table 7 and the hot wall surface table support 8 are in threaded connection, and all sensor interfaces and liquid drop supply inlets can be connected through the experiment cavity upper cover 1.

The heating system comprises two parts, wherein a first part table top heating plate 6 is connected with an experimental cavity bottom cover 4 by adopting a high-temperature insulating bolt 5, and the figure 3 can clearly show; the second part cavity heating plate 2 is connected with the experiment cavity 1 through a high-temperature insulating bolt 3.

The high-voltage power supply output terminal of the high-voltage system is connected with the hot wall table top 7, the hot wall table top 7 is insulated from the whole experiment cavity assembly, and the high-voltage power supply provides different voltage intensities and forms so as to charge liquid drops, and the bottom cover of the experiment cavity and the like are connected with the grounding electrode.

Air supply system connects on experimental cavity bottom 4 by telescopic breather pipe 9, and after pulling down mesa hot plate 6, breather pipe 9 can be connected to hot wall mesa 7, can accomplish experiments such as nozzle blowdown after connecting, aerifys for the experiment cavity when not connecting the usefulness of exitting, and mesa hot plate 6 adopts bolted connection, convenient dismantlement.

The window is opened on upper portion, front and back both sides to experiment cavity 1, uses high temperature resistant transparent material to seal the laminating window, for example uses quartz glass, and the structure shown as figure 1 can make high temperature transparent material embed to in the experiment cavity, seals with the mode of end face seal, then uses the nut and compresses tightly the lid and compress tightly sealed, and it does not show to compress tightly the lid in this example, can be according to the nimble adjustment of the size and the demand of window.

Hot wall platform pillar 8 adopts high temperature insulation's material, for example ceramic bolt, and hot wall platform pillar 8 symmetry is installed in 7 both sides of hot wall mesa, and the other end of hot wall platform pillar carries out nut with experiment chamber cavity 1 and compresses tightly sealing connection, and sealing material also adopts high temperature resistant material, and the bolt runs through the wall of experiment chamber cavity 1, and the outside at experiment chamber upper cover 1 is installed to the nut.

The table top heating plate 6 is connected with the experimental cavity bottom cover 4 through high-temperature insulating bolts 5, the number of the high-temperature insulating bolts is more than or equal to 3, or a single insulating bolt is used in the middle of the table top heating plate, in the embodiment, 4 insulating bolts are used, a certain gap is reserved between the table top heating plate 6 and the hot wall table top 7, and the hot table top 7 is heated in a radiation heating mode.

The cavity heating plate 2 is symmetrically arranged on the left side and the right side of the experimental cavity bottom cover 4 without a window, the number of the high-temperature insulating bolts 3 adopted on each side is more than or equal to 3, or a single insulating bolt is used in the middle of the table top heating plate, 4 insulating bolts are used in the embodiment, and the cavity heating plate can perform radiation heating on the whole cavity.

As shown in fig. 5-6, the hot wall table 7 is divided into two types, one type is a round table with a threaded hole, and nozzles of different materials and different apertures can be arranged in the threaded hole, so that the hot wall table is very convenient to disassemble and replace; the other surface is a plane and the other surface has different radiation power according to the mesa heating plate 6, and the other surface is a receiving surface for radiation heating, and the geometric dimension of the irregularly-shaped surface obtained by optimizing heat exchange calculation, such as the circular arc shape in the example, is used for ensuring that the heat flow density of the surface is uniform.

The experimental method of the experimental device for researching the evaporation and coking of the hydrocarbon fuel liquid drops on the micro-scale hot wall surface comprises the following steps:

1. according to different experimental requirements, installing different hot wall table tops 7, for example, researching the reaction of droplet evaporation and stainless steel hot wall materials under the condition of no high voltage, firstly connecting a table top heating plate 6 to the experimental cavity bottom cover 4 through a second high-temperature insulating bolt 5;

2. connecting a cavity heating plate 2 to a cavity 1 of the experimental cavity through a first high-temperature insulating bolt 3, then installing a single-plane hot wall table top 7 on the cavity 1 of the experimental cavity through a hot wall table support 8, and screwing the hot wall table support 8 on the cavity 1 of the experimental cavity through a nut;

3. installing quartz glass on the experimental cavity body 1, sealing and screwing, and simultaneously sealing and screwing the experimental cavity body 1 and the experimental cavity bottom cover 4 by using bolts;

4. testing the tightness after the pressure, temperature and other sensors are tested to be correct, introducing different gases according to the requirements, such as anhydrous air, testing the tightness, and keeping the pressure under the experimental pressure of more than 2 times for 24 hours in a closed manner, wherein the pressure change is not more than 1%;

5. the interior of the cavity is subjected to radiation heating by using the cavity heating plate 2 through a temperature control system, so that the temperature in the cavity is stable, and the hot wall table top 7 is heated by using the table top heating plate 6 to reach the specified temperature and be stably maintained;

6. debugging observation equipment, carrying out a liquid drop evaporation reaction experiment after the observation equipment is debugged, quickly dropping liquid drops on a hot wall table board through a fuel oil feeding system, testing the change of a state, and carrying out an offline microscopic test on a coked wall surface after the liquid drops are evaporated and completely reacted;

7. if the experiment charges the liquid drops through high voltage, step 6 is carried out after the high-voltage system and the corresponding test system are debugged in step 5, and power needs to be firstly switched on before step 6 is carried out;

8. if the coking of the nozzle opening is researched, the plane table top in the step 1 needs to be changed into the table top with the nozzle opening, the steps are the same as those in the steps 1-7, it needs to be noted that the dropping of liquid drops needs to directly enter the nozzle opening, another experiment mode can also be adopted, the liquid drops are firstly dropped in the step 5, the subsequent steps are carried out, if the coking of the nozzle opening with the blowing-off is researched, the liquid drops need to be dropped into the nozzle in advance in the step 1, the steps 1-3 are carried out, the blowing-off step needs to be added in the step 3, and then the steps 4-6 are carried out;

9. different materials of the table top and different hydrocarbon fuels are replaced according to the requirements to carry out experiments.

The above-mentioned embodiments further explain the objects, technical solutions and advantages of the present invention in detail. It should be understood that the above-mentioned embodiments are only examples of the present invention, and are not intended to limit the present invention, and that the reasonable combination of the features described in the above-mentioned embodiments can be made, and any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.