Automatic circulation device and automatic circulation method thereof

Abstract

The invention relates to an automatic circulating device which comprises a water vapor generator, a tubular furnace, an isolation cover, a water spraying system and a reciprocating sample feeding rod, the isolation cover comprises a connecting end and a free end which are opposite to each other, the tubular furnace is fixedly connected with the connecting end of the isolation cover to provide a closed cavity, the tubular furnace provides a temperature field for the closed cavity, and the water spraying system is used for spraying water to the sample feeding rod. The steam generator is connected with the tubular furnace to introduce steam into the closed cavity, the sample feeding rod penetrates through the free end of the isolation cover to extend a sample into the closed cavity, and the water spraying system is mounted at the connecting end of the isolation cover to spray liquid water to the sample exiting from the tubular furnace to cool the sample to room temperature. The invention further discloses an automatic circulation method of the automatic circulation device. According to the automatic circulation device and the automatic circulation method thereof, a material simulation service environment for water-oxygen corrosion in a superhigh-temperature environment can be reproduced, and superhigh-temperature and long-time water-oxygen corrosion and automatic circulation under water-oxygen corrosion can be realized.

Description

Technical Field

[0001] The present invention relates to a simulation device, and more particularly to an automatic circulation device and an automatic circulation method thereof. Background Art

[0002] In recent years, great progress has been made in aero-engine technology, especially in the development of engines with excellent performance such as high bypass ratio, high thrust-to-weight ratio, and high turbine inlet temperature. With the increase in intake air temperature, the hot-end components of the engine need to withstand more severe thermal loads and harsher working environments, which poses higher requirements for related materials.

[0003] Silicon carbide fiber-reinforced silicon carbide ceramic matrix composite (SiCf / SiC CMC) has become the most promising candidate material due to its low density, excellent high-temperature stability, and reliability. SiCf / SiC CMC components, such as combustor liners and turbine blades, have been developed and evaluated for decades to verify their applications in military and civil aero-engines. The application of using SiCf / SiC CMC not only helps to improve thermal efficiency but also reduces structural weight.

[0004] However, after being exposed to the combustion environment for thousands of hours, SiCf / SiC CMC components will rapidly deteriorate due to the reaction between the protective silica scale and high-temperature steam. To reduce this deterioration rate, researchers have adopted matrix modification methods such as element doping and nanotube reinforcement. In addition, environmental barrier coatings (EBCs) have been developed to protect hot-end components from the harmful corrosion of combustion gases.

[0005] In a high-temperature service environment, the main failure modes of CMC and EBCs are manifested as reactions with high-temperature water vapor and erosion by molten CMAS. To study the service behavior and failure mechanism of CMC and EBCs in a high-temperature water vapor environment, it is necessary to reproduce the simulated environment of high-temperature water vapor in the laboratory.

[0006] Although existing devices can provide high temperature and water-oxygen corrosion environments, they lack an automatic circulation function and cannot simulate the thermal cycle during engine start-up and shutdown, which has limitations for studying the failure mechanism of materials and simulating the real service environment. Summary of the Invention

[0007] In order to solve the problem in the above-mentioned prior art that the cyclic service of materials in a high-temperature water vapor environment cannot be simulated, the present invention provides an automatic circulation device and an automatic circulation method thereof.

[0008] The automatic circulation device according to the present invention includes a steam generator, a tubular furnace, an isolation cover, a water spray system, and a reciprocating sample feeding rod. Among them, the isolation cover includes a relative connection end and a free end. The connection end of the tubular furnace and the isolation cover are fixedly connected to provide a closed cavity. The tubular furnace provides a temperature field for this closed cavity. The steam generator is connected to the tubular furnace to introduce steam into this closed cavity. The sample feeding rod passes through the free end of the isolation cover to extend the sample into this closed cavity. The water spray system is installed at the connection end of the isolation cover to spray liquid water on the sample exiting from the tubular furnace to cool it down to room temperature.

[0009] In a preferred embodiment, the connection end of the isolation cover is fixedly connected to the tubular furnace through a flange, and the free end is relatively closed to relatively enclose the steam from the tubular furnace within the isolation cover.

[0010] In a preferred embodiment, the isolation cover is a compressible metal bellows.

[0011] In a preferred embodiment, the sample feeding rod is a hollow alumina ceramic tube, having opposite first and second ends. The first end is used to hold the sample to form a sample end, and the second end is formed as a steam recovery outlet.

[0012] In a preferred embodiment, the automatic circulation device further includes a cylinder, which is connected to the sample feeding rod to drive the sample feeding rod.

[0013] In a preferred embodiment, the automatic circulation device further includes a base for supporting and installing the isolation cover.

[0014] In a preferred embodiment, the automatic circulation device further includes a guide rail, and the sample feeding rod is movably installed on the base through the guide rail.

[0015] In a preferred embodiment, relays are respectively installed at opposite ends of the guide rail for controlling the start and stop positions of the sample feeding rod.

[0016] In a preferred embodiment, the automatic circulation device further includes a water recovery outlet, which is installed below the connection end of the isolation cover for discharging the recovered liquid water.

[0017] The automatic circulation method of the above-mentioned automatic circulation device according to the present invention includes the following steps: S1, providing a temperature field for the closed cavity through a tube furnace, and introducing water vapor into the closed cavity through a water vapor generator; S2, setting the in-furnace heat preservation time, the out-of-furnace cooling time, and the number of cycles through an electric control box; S3, starting the cycle, and each cycle process includes: sending the sample into the tube furnace through a sample feeding rod and staying for the in-furnace heat preservation time; pulling the sample out of the tube furnace through the sample feeding rod, staying directly below the water spray system, and starting the water spray system to spray and cool the sample for the out-of-furnace cooling time; continuing the cycle according to the set number of cycles; S4, turning off the water vapor generator and the tube furnace.

[0018] The automatic circulation device and its automatic circulation method according to the present invention are used for ultra-high temperature water oxygen corrosion in a water vapor environment, can reproduce the material simulation service environment of water oxygen corrosion in an ultra-high temperature environment, and can achieve ultra-high temperature, long-time water oxygen corrosion and automatic circulation under water oxygen corrosion. Brief Description of the Drawings

[0019] Figure 1 It is a schematic structural diagram of an automatic circulation device according to a preferred embodiment of the present invention. Detailed Description of the Invention

[0020] The following combines the drawings to give a preferred embodiment of the present invention and describes it in detail.

[0021] As Figure 1 shown, an automatic circulation device according to a preferred embodiment of the present invention includes a tube furnace 2 and an isolation cover 8. The tube furnace 2 and the isolation cover 8 are fixedly connected through a flange 3 to jointly form a relatively closed cavity. The high-temperature environment of the entire closed cavity is provided with a uniform temperature field by the tube furnace 2, and the high-temperature range is 1200°C to 1700°C to provide a high-temperature function.

[0022] The automatic circulation device further includes a water vapor generator (not shown in the figure). The water vapor generator is fixedly connected to one side of the tube furnace 2 far from the isolation cover 8 through an interface 1 for introducing water vapor into the tube furnace 2. It should be understood that oxygen or air with pressure can also be introduced into the tube furnace 2 through the interface 1 as needed to provide a water oxygen corrosion function.

[0023] The isolation cover 8 includes an opposite connection end and a free end. The connection end of the isolation cover 8 is fixedly connected to the tube furnace 2 through a flange 3, and the free end is relatively closed, thereby relatively enclosing the water vapor from the tube furnace 2 within the isolation cover 8. In this embodiment, the isolation cover 8 is a compressible metal bellows.

[0024] The automatic circulation device further includes a reciprocating sample feeding rod 10, which extends into the isolation hood 8 and the tubular furnace 2 through the free end of the isolation hood 8. In this embodiment, the sample feeding rod 10 is a hollow alumina ceramic tube, having opposite first and second ends. The first end is cut into the shape of a porcelain boat for holding a sample (such as a hot-end component of an aero-engine), forming a sample end; the second end is formed as a water vapor recovery outlet 11, and the refluxed water vapor is led out through a flange-connected air pipe. The water vapor is a pressurized gas, and pressurized oxygen or air may also be required when simulating the environment. The water vapor recovery outlet 11 is used to relieve the pressure of the environment of the entire closed cavity, and it is placed in a recovery bucket. The recovery bucket is used to collect the high-temperature water vapor discharged through the water vapor recovery outlet 11, avoiding the direct discharge of high-temperature water vapor into the environment, thereby ensuring the safety of the experimental personnel.

[0025] The automatic circulation device further includes a base 7, a pressing piece 9, a guide rail 12, a connecting piece 13 and a cylinder 14. The base 7 is placed on the experimental platform on the first side of the tubular furnace 2 for supporting and installing the isolation hood 8. The guide rail 12 is installed on the base 7, and the sample feeding rod 10 is installed on the guide rail 12 through the pressing piece 9 to achieve movable installation. The cylinder 14 is supported and installed on the base 7 through the connecting piece 13 and is connected to the sample feeding rod 10 to drive the sample feeding rod 10. In this embodiment, relays are respectively installed at opposite ends of the guide rail 12 for controlling the start and stop positions of the sample feeding rod 10. When the sample needs to enter the tubular furnace 2, the relay controls the cylinder 14 to push the sample feeding rod 10 into it; when the sample needs to leave the tubular furnace 2, the relay controls the cylinder 14 to pull the sample feeding rod 10 back.

[0026] The automatic circulation device further includes a water spray system 4 and a water recovery outlet 6. The water spray system 4 is installed above the connecting end of the isolation hood 8 for spraying liquid water into the isolation hood 8; the water recovery outlet 6 is installed below the connecting end of the isolation hood 8 for leading out and recovering the liquid water in the isolation hood 8 through a pipe. In this embodiment, the automatic circulation device further includes a sample observation window 5, which is installed on the side of the connecting end of the isolation hood 8 to facilitate observing the situation inside the isolation hood 8. In this embodiment, the water spray system 4 pumps deionized water from a water bucket into the device by a small water pump, and the lower end is connected to a shower head to spray water to cool the sample to room temperature. After the sample exits the tubular furnace 2, it is cooled by the water spray system 4 to achieve a thermal cycle between high temperature and low temperature, simulating the service environment of the hot-end components caused by the frequent start and stop of an aero-engine.

[0027] The automatic circulation device further includes an electric control box (not shown in the figure). The electric control box is respectively connected to the water spray system 4 and the cylinder 14 for controlling the start and stop of the water spray system 4 and the reciprocating movement of the sample feeding rod 10.

[0028] The automatic circulation method according to the present invention includes the following steps:

[0029] 1) Connect the steam generator to the tube furnace 2 through interface 1, and connect the isolation cover 8 to the other side of the tube furnace 2 through flange 3.

[0030] 2) Place the sample at the sample end of the sample feeding rod 10, and connect the steam recovery outlet 11 to the trachea through a flange and place it inside the recovery barrel.

[0031] 3) Turn on the tube furnace 2 and raise the temperature to the required temperature.

[0032] 4) Turn on the steam generator, set an appropriate air pressure, and ensure that the steam recovery outlet 11 remains open to relieve the pressure inside the entire device.

[0033] 5) Turn on the power supply of the electric control box and set the required parameters, including the in-furnace heat preservation time, the out-of-furnace cooling time, and the number of cycles required.

[0034] 6) Turn on the circulation switch and the circulation will start. The circulation process includes:

[0035] The control circuit starts the cylinder 14 to send the sample into the tube furnace 2 through the sample feeding rod 10.

[0036] Control the residence time of the sample in the tube furnace 2 according to the heat preservation time set by the user.

[0037] Start the cylinder 14 to pull the sample out of the tube furnace 2 through the sample feeding rod 10 and stay directly below the water spray system 4.

[0038] Start the water spray system 4 to spray and cool the sample according to the cooling time set by the user.

[0039] After completing one cycle, continue the cycle according to the number of cycles set by the user.

[0040] 7) After completing the last cycle and the sample has completely cooled to room temperature, turn off the heating systems of the steam generator and the tube furnace 2 to ensure the safe shutdown of the device.

[0041] The sample in the sample feeding rod 10 of the present invention is completely in a closed water vapor environment. The sample feeding rod 10 is controlled to reciprocate in and out of the tube furnace 2 through a closed-circuit electric control box, and the direct cooling of the sample is achieved through the water spray system 4 to ensure the thermal cycle of the sample from ultra-high temperature to room temperature in the water vapor environment. The complex service environment of the sample is simulated through the thermal cycle in the water vapor environment, and the automatic cycle of water-oxygen corrosion at ultra-high temperature is realized, providing a more realistic simulation environment for studying the service behavior and failure mechanism of materials. Moreover, when the cycle function is not required, the present invention can be used alone for long-term thermal exposure under water-oxygen corrosion, that is, the temperature rise and fall function without thermal cycle of water-oxygen corrosion is used in the furnace, so as to be compatible with the long-term isothermal water vapor environment thermal exposure service.

[0042] In particular, the present invention can control the residence time (holding time) of the sample in the high-temperature environment and the residence time (cooling time) of the sample in the room-temperature environment through a timer, record the number of cycles through a counter to ensure that the experiment is carried out according to the predetermined number of cycles, and drive the sample feeding rod 10 to reciprocate inside and outside the tube furnace 2 through the cylinder 14 to form a propulsion mechanism. A seal can be provided between the sample feeding rod 10 and the free end of the isolation cover 8 through a sealing ring or gasket to prevent the leakage of water vapor. The sample is quickly cooled from ultra-high temperature (such as 1200°C - 1700°C) to room temperature through the liquid water spray system 4 to simulate the thermal cycle during the start and stop of the engine, ensuring the safety and accuracy of the experimental process. During the operation process, the tightness of all connection points should be ensured to avoid the leakage of high-temperature water vapor and ensure the safety of the experimental personnel.

[0043] The above is only the preferred embodiment of the present invention and is not intended to limit the scope of the present invention. Various changes can be made to the above embodiments of the present invention. That is, all simple, equivalent changes and modifications made according to the claims and the content of the specification of the present invention application fall within the scope of the claims of the present invention patent. The content not described in detail in the present invention is all conventional technical content.

Claims

1. An automatic circulation device, characterized in that, The automatic circulation device includes a steam generator, a tube furnace, an isolation hood, a water spray system, and a reciprocating sample feeding rod. Among them, the isolation hood includes a relative connection end and a free end. The connection end of the tube furnace and the isolation hood are fixedly connected to provide a closed cavity. The tube furnace provides a temperature field for the closed cavity. The steam generator is connected to the tube furnace to introduce steam into the closed cavity. The sample feeding rod passes through the free end of the isolation hood to extend the sample into the closed cavity. The water spray system is installed at the connection end of the isolation hood to spray liquid water on the sample withdrawn from the tube furnace to cool it down to room temperature.

2. The automatic circulation device according to claim 1, characterized in that, The connection end of the isolation hood is fixedly connected to the tube furnace through a flange. The free end is relatively closed to relatively enclose the steam from the tube furnace within the isolation hood.

3. The automatic circulation device according to claim 1, characterized in that, The isolation hood is a compressible metal bellows.

4. The automatic circulation device according to claim 1, characterized in that, The sample feeding rod is a hollow alumina ceramic tube with opposite first and second ends. The first end is used to hold the sample to form a sample end, and the second end is formed as a steam recovery outlet.

5. The automatic circulation device according to claim 1, characterized in that, The automatic circulation device further includes a cylinder, which is connected to the sample feeding rod to drive the sample feeding rod.

6. The automatic circulation device according to claim 1, wherein The automatic circulation device further includes a base for supporting and installing the isolation hood.

7. The automatic circulation device according to claim 6, characterized in that, The automatic circulation device further includes a guide rail. The sample feeding rod is movably installed on the base through the guide rail.

8. The automatic circulation device according to claim 7, wherein Relays are respectively installed at opposite ends of the guide rail for controlling the start and stop positions of the sample feeding rod.

9. The automatic circulation device according to claim 1, wherein The automatic circulation device further includes a water recovery outlet, which is installed below the connection end of the isolation hood for discharging the recovered liquid water.

10. An automatic circulation method of the automatic circulation device according to any one of claims 1-9, characterized in that, The automatic circulation method includes the following steps: S1, Provide a temperature field for the closed cavity through the tube furnace, and introduce steam into the closed cavity through the steam generator; S2, Set the in-furnace heat preservation time, the out-of-furnace cooling time, and the number of cycles through the electric control box; S3, Start the cycle. Each cycle process includes: Send the sample into the tube furnace through the sample feeding rod and stay for the in-furnace heat preservation time; Pull the sample out of the tube furnace through the sample feeding rod, stay directly below the water spray system, and start the water spray system to spray and cool the sample for the out-of-furnace cooling time; Continue the cycle according to the set number of cycles; S4, Turn off the steam generator and the tube furnace.

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