An experimental chamber and system for multi-mode droplet combustion characteristics

Abstract

The present invention belongs to the field of engine droplet combustion experiments, and particularly relates to an experimental chamber for droplet combustion characteristics, including a housing. One side of the housing is provided with an observation window. The housing is provided with a combustion chamber, and a heating device is arranged in the combustion chamber. The top of the housing is connected with a pressure pipe and a drip pipe, both of which are communicated with the combustion chamber. The pressure pipe is used for injecting gas to increase the air pressure in the combustion chamber, and the drip pipe is connected with a supply system for dripping liquid fuel. The experimental chamber of the present invention can control variables and conduct combustion experiments in different modes under various different pressures and temperatures.

Description

Technical Field

[0001] The present invention belongs to the field of engine droplet combustion experiments, and particularly relates to a multi-mode droplet combustion characteristic experimental chamber and its system. Background Art

[0002] Spray combustion is a common form of liquid fuel combustion and is widely used in power devices such as internal combustion engines, aircraft, and liquid rocket engines. A liquid mist consists of a large number of droplets, and droplet combustion is the basis of spray combustion. A droplet combustion test bench is a teaching or scientific research experimental system used to study the combustion process of propellants in the combustion chamber of liquid propellant or gel propellant engines, and can be roughly divided into hanging-drop type and flying-drop type single-droplet / multi-droplet combustion experimental systems. In practical applications, teaching and research workers design corresponding droplet combustion experimental systems according to their own task requirements.

[0003] Existing droplet combustion experimental systems mainly differ in aspects such as combustion chamber structure, ignition method, and nozzle structure. Among them, the combustion chamber structure determines the combustion conditions of droplet experiments, such as high temperature, high pressure, oxidative / inert environment; the ignition method determines the ignition conditions of droplets, such as planar flame, electric heating, or laser ignition; the nozzle structure determines whether droplets are formed through a showerhead type, multi-droplets, or dual-component mutual impact, forming single droplets or multi-droplets, which has a certain impact on the observation of the droplet combustion mechanism.

[0004] Such as Figure 5 Shown is a schematic diagram of a flying-drop type single-droplet combustion experimental device in the prior art. The experimental device mainly consists of a droplet injection system, a high-temperature heat source, and an image acquisition system. The droplet injection system mainly includes: a droplet injector and a signal drive power supply; the high-temperature heat source mainly includes: a gas source and a planar flame burner; the image acquisition system mainly includes: a CCD / single-lens reflex camera, a stroboscope / light source, and a computer. In this experimental device, droplets freely fall and are ignited by the high temperature generated by the planar flame when passing through the outlet of the planar flame burner, forming a strip-shaped flame in the glass tube. This experimental device is carried out under normal pressure, cannot simulate the real environment of the combustion chamber, has a single mode of forming droplets, and is limited by the design and can only carry out flying-drop type single-droplet combustion experiments. Summary of the Invention

[0005] The purpose of the present invention is to provide a multi-mode droplet combustion characteristic experimental chamber and its system to solve the deficiencies in the prior art.

[0006] To achieve the above-mentioned invention purpose, the technical solution adopted by the present invention is:

[0007] A droplet combustion characteristic experimental chamber includes a housing. An observation window is provided on one side of the housing, and a combustion chamber is provided in the housing. A heating device is provided in the combustion chamber.

[0008] A pressure pipe and a drip pipe are connected to the top of the housing, and both communicate with the combustion chamber. The pressure pipe is used to inject gas to increase the air pressure in the combustion chamber, and the drip pipe is connected to a supply system for dripping liquid fuel.

[0009] Furthermore, a condensate pipe is arranged inside the drip pipe, a cooling chamber is arranged between the drip pipe and the condensate pipe, and the cooling chamber is connected to a water cooling system;

[0010] The bottom of the drip pipe is detachably connected to a spray head. The bottom of the drip pipe is connected to the spray head, and its top is connected to the supply system.

[0011] Furthermore, the top of the condensate pipe is detachably connected to an upper plug, and the bottom is detachably connected to a lower plug. The lower plug is provided with a mixing chamber with an opening facing downwards, and the spray head is detachably connected inside the mixing chamber;

[0012] The condensate pipe passes through the upper plug and the lower plug, and its bottom is arranged inside the mixing chamber.

[0013] Furthermore, one or two condensate pipes are provided;

[0014] When two condensate pipes are provided, the spray head is provided with a groove with an opening facing upwards. The groove is located inside the mixing chamber, and a partition plate is fixedly arranged inside the groove. The bottoms of the two condensate pipes are respectively arranged on both sides of the partition plate. The bottom of the spray head is provided with spray holes corresponding to the two condensate pipes. The two spray holes are inclined and symmetrically arranged to make the ejected liquid droplets collide. The two condensate pipes are respectively used for dripping liquid fuel and oxidant.

[0015] Furthermore, the housing includes an inner shell and an outer shell sleeved on the inner shell. A cooling channel is arranged between the inner and outer shells, and the cooling channel is connected to the water cooling system.

[0016] Furthermore, an upper liquid collecting chamber and a lower liquid collecting chamber are respectively arranged at the upper and lower parts of the outer shell. The upper liquid collecting chamber and the lower liquid collecting chamber are communicated through the cooling channel;

[0017] Water inlet connectors and drain connectors communicating with the upper and lower liquid collecting chambers are respectively arranged on the side of the outer shell. The water inlet and drain connectors are connected to the water cooling system.

[0018] Furthermore, the observation window is arranged on the outer shell, and the outer shell is provided with an opening corresponding to the observation window.

[0019] A liquid droplet combustion characteristic experiment system includes an experimental chamber, and also includes a gas supply device. The pressure pipe is connected to the gas supply device through a valve.

[0020] Further, it further includes a high-speed camera, a temperature controller, and a pressure detector connected to the control device;

[0021] The high-speed camera is arranged facing the observation window. The heating device is connected to the control device through the temperature controller. The detection end of the pressure detector is arranged in the combustion chamber for detecting the pressure in the combustion chamber.

[0022] Further, the supply system includes a fuel storage tank. One side of the fuel storage tank is connected to the drip tube through a pump body, and the other side is connected to an oxidant storage through a valve.

[0023] The present invention has the following beneficial effects: The gas supply device adds gas into the combustion chamber to form a high-pressure environment, and adjusts the temperature through the heating device. Then, liquid fuel is dripped through the drip tube, so that the fuel can fall in a droplet shape in the high-pressure environment and burn. By observing the combustion condition through the observation window and recording the experimental results, the experimental cabin of the present invention can control variables and conduct different-mode droplet combustion experiments under various different pressures and temperatures. Description of the Drawings

[0024] Figure 1 It is an overall schematic diagram of a droplet combustion characteristic experimental cabin of the present invention;

[0025] Figure 2 It is a schematic cross-sectional view of the experimental cabin;

[0026] Figure 3 It is a schematic diagram of two implementation manners of the condensate tube;

[0027] Figure 4 It is a schematic diagram of a droplet combustion characteristic experimental system of the present invention;

[0028] Figure 5 It is a schematic diagram of a flying-droplet single-droplet combustion experimental device in the prior art Detailed Embodiments

[0029] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. If not specifically specified, the technical means used in the embodiments are conventional means well known to those skilled in the art. Figures 1-4 It should be noted that, without conflict, the implementation manners and features in the implementation manners of the present invention can be combined with each other.

[0030]

[0031] ​It should be noted that like reference numerals and letters refer to like items in the following figures. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0032] In the description of the present invention, it should be noted that the orientation or positional relationship indicated by the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings, or the orientation or positional relationship in which the product of the present invention is customarily placed during use, or the orientation or positional relationship commonly understood by those skilled in the art. It is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus should not be construed as a limitation of the present invention. In addition, the terms "first", "second", etc. are only used for distinguishing descriptions and cannot be understood as indicating or implying relative importance.

[0033] In the description of the present invention, it should also be noted that unless otherwise clearly specified and defined, the terms "set", "installed", "connected", "connected" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the communication inside two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0034] Such as Figure 1 , 2 , a droplet combustion characteristic experimental chamber, including a housing 1, a viewing window 10 is provided on one side of the housing 1, a combustion chamber is provided in the housing 1, and a heating device is provided in the combustion chamber;

[0035] The top of the housing 1 is connected with a pressure pipe 2 and a liquid dropping pipe 4, and both are communicated with the combustion chamber. The pressure pipe 2 is used to inject gas to increase the air pressure in the combustion chamber, and the liquid dropping pipe 4 is connected with a supply system for dropping liquid fuel.

[0036] Specifically, the liquid fuel is a liquid propellant. The observation window 10 is a quartz observation window, which can withstand a pressure of more than 16 MPa at 500 °C. The heating device is a prior art and can be a tubular air heater 16, which is arranged around the drip tube 4 to heat the combustion chamber to the required temperature for combustion. The bottom of the pressure pipe 2 is connected to the combustion chamber. The pressure pipe 2 is connected to a gas supply device, which is used to add nitrogen / oxygen / air / oxidant, etc. to the combustion chamber to form a high-pressure environment. A valve is arranged between the gas supply device and the pressure pipe 2 to control the amount of gas added. Then, the liquid fuel is dripped through the drip tube 4, so that the fuel can fall in a droplet shape in the high-pressure environment and burn. Then, the combustion condition is observed through the observation window 10, that is, the experimental results are recorded. By controlling the amount of gas injected by the gas supply device, the pressure can be adjusted. And by adjusting the heating temperature of the heating device, the experimental cabin of the present invention can control variables and perform droplet combustion experiments in different modes under various different pressures and temperatures.

[0037] Further, a condensate pipe 3 is arranged in the drip tube 4. A cooling chamber is arranged between the drip tube 4 and the condensate pipe 3, and the cooling chamber is connected to a water cooling system;

[0038] The bottom of the drip tube 4 is detachably connected to a nozzle 13. The bottom of the drip tube 4 is connected to the nozzle 13, and its top is connected to the supply system.

[0039] The condensate pipe 3 is cooled by the water cooling system, so that the liquid fuel, that is, the propellant, is cooled and condensed. During the actual experiment, affected by the high-temperature environment of the combustion chamber, the temperature of the drip tube 4 is relatively high. In order to prevent the propellant from evaporating due to too high a temperature before entering the combustion chamber, the built-in cooling system of the drip tube 4 effectively reduces the temperature of the propellant before entering the combustion chamber, improves the accuracy of the experimental results, that is, excludes the influence of the high temperature of the propellant on the experimental results.

[0040] In addition, the top of the drip tube 4 extends out of the housing 1, and a water inlet end joint 5 and a water outlet pipe 6 are fixedly arranged on the side. The water inlet end joint 5 is communicated with the cooling chamber, and one end of the water outlet pipe 6 is arranged at the lower part in the cooling chamber.

[0041] Further, the top of the condensate pipe 3 is detachably connected to an upper plug 14, and the bottom is detachably connected to a lower plug 12. The lower plug 12 is provided with a mixing chamber with an opening facing downwards, and the nozzle 13 is detachably connected in the mixing chamber;

[0042] The condensate pipe 3 passes through the upper plug 14 and the lower plug 12, and its bottom is arranged in the mixing chamber.

[0043] The upper and lower plugs achieve the function of sealing and connecting the condensate pipe 3. There can be various connection methods between the condensate pipe 3 and the plugs, such as threaded fit and interference fit. The condensate pipe 3 injects the propellant into the mixing chamber and then sprays it out through the nozzle 13. The nozzle 13 is a prior art and can be a single-droplet or multi-droplet nozzle.

[0044] The nozzle 13 and the lower plug 12 can be detachably connected by threads. Thus, by replacing the single-droplet or multi-droplet nozzle 13, single-droplet or multi-droplet combustion experiments can be achieved.

[0045] Furthermore, one or two condensate pipes 3 are provided.

[0046] When two condensate pipes 3 are provided, the nozzle 13 is provided with a groove with an upward opening, and the groove is located in the mixing chamber. A partition plate 131 is fixedly arranged in the groove. The bottoms of the two condensate pipes 3 are respectively arranged on both sides of the partition plate 131. The bottom of the nozzle 13 is provided with spray holes 132 corresponding to the two condensate pipes 3. The two spray holes 132 are inclined and symmetrically arranged to make the ejected droplets collide. The two condensate pipes 3 are respectively used for dripping liquid fuel and oxidant.

[0047] Such as Figure 3 , there are two implementation modes for the condensate pipe 3 in the present invention, that is, one or two are provided:

[0048] When one condensate pipe 3 is provided, the corresponding nozzle 13 is a single-droplet or multi-droplet nozzle to achieve single-droplet or multi-droplet combustion experiments.

[0049] When two condensate pipes 3 are provided, the propellants injected by the two condensate pipes 3 enter the mixing chamber and are separated by the partition plate 131, that is, the liquid fuel and the oxidant are separated. The liquid fuel and the oxidant are ejected through the spray holes 132 and collide to form a mutual-impact and dispersed droplet fuel. In this embodiment, the nozzle 13 can also adopt other mutual-impact and impact nozzles in the prior art.

[0050] In addition, a connecting flange 18 is fixedly arranged at the lower part of the drip pipe 4. The connecting flange 18 is connected to the inner wall of the top of the housing 1 by screws, that is, the bottom of the upper flange 9.

[0051] The present invention can achieve combustion tests with various dripping modes by replacing the two forms of condensate pipes 3 and nozzles 13.

[0052] Furthermore, the housing 1 includes an inner housing 102 and an outer housing 101 sleeved on the inner housing 102. A cooling channel 104 is arranged between the inner and outer housings. The cooling channel 104 is connected to the water cooling system.

[0053] Specifically, the interior of the inner shell 102 is the combustion chamber. The water cooling system not only cools the drip tube 4 but also cools the entire housing 1 to prevent overheating.

[0054] Furthermore, an upper liquid collecting chamber 103 and a lower liquid collecting chamber 105 are respectively arranged at the upper and lower parts of the outer shell 101. The upper liquid collecting chamber 103 is communicated with the lower liquid collecting chamber 105 through the cooling channel 104.

[0055] Water inlet connectors 11 and drain connectors 7 for communicating the upper and lower liquid collecting chambers are respectively arranged on the side surface of the outer shell 101. The water inlet and drain connectors are connected to the water cooling system.

[0056] Both the upper and lower liquid collecting chambers are annularly distributed and arranged in a circle around the circumference of the combustion chamber. The cooling channel 104 is in a groove structure, opened on the inner side surface of the outer shell 101, and the opening is attached to the outer side surface of the inner shell 102. And a plurality of cooling channels 104 are arranged around the inner shell 102.

[0057] In addition, both the inner and outer shells are hollow structures. Their upper and lower end faces are respectively connected to the upper flange 9 and the lower flange 8 by screws. The drip tube 4 passes through the upper flange 9, and a discharge port 17 is arranged on the lower flange 8 for discharging waste.

[0058] Furthermore, the observation window 10 is arranged on the outer shell 101, and the outer shell 101 is provided with an opening part 15 corresponding to the observation window 10.

[0059] The position of the observation window 10 corresponds to the opening part 15, so that the combustion chamber can be observed through the opening part 15. And the opening part 15 is located in the radial direction of the drip tube 4, and the dripping combustion condition can be observed. The observation window 10 is vertically arranged at 90 degrees and is located in the radial direction of the outer shell 101.

[0060] Such as Figure 4 , the present invention relates to an experimental system for droplet combustion characteristics, including an experimental chamber, and further includes a gas supply device. The pressurized pipe 2 is connected to the gas supply device through a valve.

[0061] Specifically, the gas supply device is a gas storage tank, which stores high-pressure nitrogen / oxygen / air / oxidant, etc. It is connected to the pressurized pipe 2 of the experimental chamber through a pipeline, and a stop valve is arranged on the pipeline for adjusting the amount of the gas filled. According to specific experimental requirements, a pressure pump can also be arranged on the pipeline to provide a greater gas pressure for the experimental chamber.

[0062] Furthermore, it further includes a high-speed camera, a temperature controller and a pressure detector connected to a control device;

[0063] The high-speed camera is arranged facing the observation window 10. The heating device is connected to the control device through a thermostat. The detection end of the pressure detector is arranged in the combustion chamber for detecting the combustion chamber pressure.

[0064] Specifically, the high-speed camera can be of the prior art. The control device controls parameters such as the shooting interval, aperture, and exposure time of the high-speed camera to capture and record the required combustion pictures and videos. The heating device is an air heater, and its connection method to the control device through a thermostat is of the prior art, which can realize the control of the heating temperature of the heating device. The pressure detector can be a pressure gauge arranged on the housing 1. By reading the pressure, the cut-off valve adjusts the amount of gas filled into the gas storage tank, thereby realizing the function of adjusting the pressure in the experimental cabin.

[0065] Furthermore, the supply system includes a fuel storage tank. One side of the fuel storage tank is connected to the drip tube 4 through a pump body, and the other side is connected to an oxidant storage tank through a valve.

[0066] Specifically, the fuel storage tank is a propellant storage tank, and the pump body is a micro-injection pump, which can adjust the amount of propellant injected. The micro-injection pump is connected to the drip tube 4 through a pipeline. The oxidant storage tank is a nitrogen storage tank, which is connected to the propellant storage tank through a pressure reducing valve, a filter, and corresponding pipelines, and then is injected into the drip tube 4 together with the propellant through the micro-injection pump, thereby forming the mixed combustion of the combustion-supporting agent and the propellant.

[0067] There are two supply systems. When the condensate pipe 3 adopts the implementation mode with a quantity of one, only one supply system is connected to the condensate pipe 3; when the condensate pipe 3 adopts the implementation mode with a quantity of two, the two supply systems are respectively connected to the two condensate pipes 3. The nitrogen storage tank in one supply system is closed, and only the propellant is output. The propellant storage tank in the other supply system is an empty tank, that is, no propellant is output, and only nitrogen is output. Thus, in cooperation with the two implementation modes of the condensate pipe 3, various combustion experiments in multiple modes are improved.

[0068] In addition, the water cooling system specifically includes a cooling pipeline. A cooling water tank / water source and a pump body are arranged on the cooling pipeline. The water inlet end of the cooling pipeline is connected to the water inlet end joint 5 and the water inlet connection head 11, and its water outlet end is connected to the water outlet pipe 6 and the drain connection head 7. The cooling water tank / water source can be cooled in the form of air cooling.

[0069] The above-described embodiments are only descriptions of the preferred modes of the present invention, and do not limit the scope of the present invention. Without departing from the design spirit of the present invention, various deformations, variations, modifications, and substitutions made by those of ordinary skill in the art to the technical solutions of the present invention should all fall within the protection scope determined by the claims of the present invention.

Claims

1. An experimental chamber for droplet combustion characteristics, characterized in that: It includes a housing (1), on one side of the housing (1) there is an observation window (10), the housing (1) is provided with a combustion chamber, and a heating device is arranged in the combustion chamber; At the top of the housing (1), a pressure pipe (2) and a drip pipe (4) are connected, and both are communicated with the combustion chamber. The pressure pipe (2) is used to inject gas to increase the air pressure in the combustion chamber; A condensate pipe (3) is arranged in the drip pipe (4), a cooling chamber is arranged between the drip pipe (4) and the condensate pipe (3), and the cooling chamber is connected to a water cooling system; The bottom of the drip pipe (4) is detachably connected to a spray head (13), and its top is connected to a supply system for dripping liquid fuel; The top of the condensate pipe (3) is detachably connected to an upper plug (14), and the bottom is detachably connected to a lower plug (12). The lower plug (12) is provided with a mixing chamber with an opening facing downwards, and the spray head (13) is detachably connected in the mixing chamber; The condensate pipe (3) passes through the upper plug (14) and the lower plug (12), and its bottom is arranged in the mixing chamber; One or two condensate pipes (3) are provided; When two condensate pipes (3) are provided, the spray head (13) is provided with a groove with an opening facing upwards. The groove is located in the mixing chamber, and a partition plate (131) is fixedly arranged in the groove. The bottoms of the two condensate pipes (3) are respectively arranged on both sides of the partition plate (131). The bottom of the spray head (13) is provided with spray holes (132) corresponding to the two condensate pipes (3). The two spray holes (132) are inclined and symmetrically arranged to make the ejected liquid droplets collide. The two condensate pipes (3) are respectively used to drip liquid fuel and oxidant.

2. The droplet combustion characteristic experimental chamber according to claim 1, characterized in that: The housing (1) includes an inner housing (102) and an outer housing (101) sleeved on the inner housing (102). A cooling channel (104) is arranged between the inner and outer housings, and the cooling channel (104) is connected to the water cooling system.

3. The droplet combustion characteristic experimental chamber according to claim 2, wherein: The observation window (10) is arranged on the outer housing (101), and the outer housing (101) is provided with an opening part (15) corresponding to the observation window (10).

4. An experimental system for droplet combustion characteristics, characterized in that: It includes the experimental chamber according to any one of claims 1-3, and further includes a gas supply device. The pressure pipe (2) is connected to the gas supply device through a valve.

5. The droplet combustion characteristic experimental system according to claim 4, characterized in that: It further includes a high-speed camera, a temperature controller and a pressure detector connected to a control device; The high-speed camera is arranged facing the observation window (10). The heating device is connected to the control device through a temperature controller. The detection end of the pressure detector is arranged in the combustion chamber to detect the pressure in the combustion chamber.

6. The droplet combustion characteristic experimental system according to claim 4, characterized in that: The supply system includes a fuel storage tank. One side of the fuel storage tank is connected to the drip pipe (4) through a pump body, and the other side is connected to an oxidant storage through a valve.

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