Six-surface heating and pressurizing type heating furnace for high-temperature heat cycle

Abstract

The utility model discloses a six-surface heating and pressurizing type heating furnace, relates to a six-surface heating and pressurizing type heating furnace for high-temperature thermal circulation, belongs to the field of measurement, and comprises five-surface heating and six-surface heating by integrating a top annular heating ring, and also comprises the following steps: mounting a telescopic compression column system at the top of the heating furnace; a cooling fan is mounted on the rear right side of the heating furnace; the inert gas through hole is formed in the left side of the rear portion of the heating furnace, and the composite heat insulation layer Tac coating, the zirconium oxide aerogel layer and the metal honeycomb supporting body are installed on the inner wall of the heating furnace body. According to the utility model, through a six-surface uniform heating and pressing function, a uniform thermal field can be realized and a K-type couple can be pressed; water vapor in the material can be taken away through the inert gas through hole and the fan so as to avoid interference on the experiment, meanwhile, rapid cooling is achieved, and accurate testing of the thermal conductivity of the material under the high-temperature heat cycle of 300-600 DEG C is achieved. The method is suitable for thermal conductivity evaluation of building materials such as concrete and rocks under high-temperature thermal fatigue.

Description

TECHNICAL FIELD

[0001] The utility model relates to building thermal conductivity performance test equipment technical field, concretely is a kind of multifunctional heating furnace of integrated six face heating, dynamic compression, inert gas protection and high-efficiency heat insulation, it is applicable to the thermal conductivity test of concrete, rock and other materials in 300-600 ℃ thermal fatigue cycle. BACKGROUND

[0002] Concrete has potential as a thermal storage material in the thermal energy storage system (CTES), but current simulations mostly assume that thermal properties do not change with temperature, which can affect the accurate evaluation of its high-temperature thermal fatigue performance. Therefore, it is of great significance to understand the variation of thermal conductivity with temperature in the thermal storage system for optimizing the performance of concrete under high-temperature thermal fatigue cycle. The temperature field deviation of traditional heating furnace, slow cooling rate, lack of inert gas protection and other problems limit the accuracy of thermal conductivity test at high temperature.

[0003] In the prior art, the heating furnace in the existing document "Thermal conductivity of concrete at high temperatures for thermal energy storage applications: Experimental analysis" dissipates heat through a flap door, but does not solve the problems of multi-face heating deficiency, interference of impurity gases such as water vapor, rapid cooling, high energy consumption, serious heat loss and measurement error caused by K-type thermocouple due to insufficient compression of the sample. Therefore, there is an urgent need for a heating furnace that integrates six-face heating, compression function, inert gas protection and composite insulation structure. UTILITY MODEL CONTENT

[0004] In view of the above-mentioned shortcomings of the prior art, the utility model provides a resistance heating furnace, which can effectively solve the problems of the prior art.

[0005] To solve the above technical problems, the utility model is realized by the following technical solutions:

[0006] The utility model is a six-face heating and pressurizing type heating furnace for high-temperature thermal cycle, which comprises a six-face heating system (11, 12, 13, 14, 15, 16), a telescopic compression column (8), a fan (3), K-type thermocouples (41, 42, 43), a control system, inert gas through holes (2) and a composite insulation layer (5), the composite insulation layer (5) is uniformly distributed on the inner wall of the heating furnace; the heating furnace (1) can perform heating and cooling cycles at a controlled rate, and provides different temperature fields for two concrete samples (6)

[0007] Preferably, the six-face heating system comprises a five-face heating plate and an annular heating ring outside the telescopic compression column

[0008] (16) constitute, the heating system includes heating furnace bottom (15), top (16), left side (12), right side (13), front side (11), back side (14) six sides, wherein, five even distribution molybdenum iron chromium aluminum heating plate, and the surface is coated with zirconia coating;The six heating system (11, 12, 13, 14, 15, 16) each heating surface is adjusted by independent PID.

[0009] Preferably, the telescopic compression column (8) is vertically installed in the middle of the heating furnace (1), and is driven by a ball screw through a servo motor, and the telescopic compression column (8) can be controlled by a compression system.

[0010] Preferably, the annular heating ring (16) is installed outside the telescopic compression column (8) and located at the upper part of the compression head 100-200mm, and can move with the telescopic compression column (8), and the annular heating ring gap is less than 1mm.

[0011] Preferably, the contact surface of the silicon carbide compression head (7) is a plane with a diameter of 50mm±2mm, and the surface roughness Ra is less than or equal to 0.8μm.

[0012] Preferably, the composite insulation layer (5) is composed of TaC coating, zirconia aerogel and metal honeycomb support.

[0013] Preferably, the inert gas through hole (2) is located at the left side of the back of the heating furnace, and is connected with a nitrogen / argon gas source, and a flap door is arranged above the inert gas through hole (2), and the opening and closing of the flap door is controlled by the heating furnace control system.

[0014] Preferably, the fan (3) is located at the right side of the back of the heating furnace (1), and belongs to a high-temperature-resistant centrifugal fan, and a flap door is arranged above the fan (3), and the opening and closing of the flap door is controlled by the heating furnace control system.

[0015] Preferably, the control system includes but is not limited to a temperature control module, a compression control module and a safety protection module.

[0016] Compared with the prior art, the utility model has the following beneficial effects

[0017] This utility model's six-sided heating and pressurizing furnace utilizes six-sided uniform heating technology to improve temperature field uniformity to ±3℃, significantly exceeding the ±10℃ error range of traditional equipment and thus significantly improving testing accuracy. The annular heating coil and five-sided heating plates work together to achieve uniform heating, improving heating efficiency while maintaining long-term stable operation in high-temperature environments. It also possesses corrosion resistance, adapting to various corrosive environments. The retractable clamping column, driven by a servo motor, precisely controls the loading pressure, ensuring accurate contact between the thermocouple and the sample. This accurately reflects the material's thermal conductivity data, further enhancing the accuracy of the test results.

[0018] This heating furnace features a design that integrates a fan and inert gas vents, effectively increasing the cooling rate to 30℃ / min, far exceeding the cooling efficiency of traditional flap doors. By adjusting the flap doors, the fan and gas flow can quickly remove water vapor from the samples, preventing water vapor from adhering to the sample surface and thus avoiding interference with experimental data. The composite insulation layer, employing a TaC coating, a zirconia aerogel layer, and a metal honeycomb support, enhances the material's oxidation resistance and significantly reduces the furnace's outer wall temperature, improving insulation performance and reducing energy consumption. Attached Figure Description

[0019] To more clearly illustrate the technical solutions of the embodiments of this utility model, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0020] Figure 1 This is a schematic diagram of the front structure of this utility model;

[0021] Figure 2 This is a side view of the present invention.

[0022] Figure 3 for Figure 2 Schematic diagram of the cross-sectional structure along the AA direction;

[0023] Figure 4 for Figure 1 A magnified view of the three-dimensional structure.

[0024] The attached diagram lists the components represented by each number as follows:

[0025] 1. Heating furnace; 11. Front heating surface; 12. Left heating surface; 13. Right heating surface; 14. Rear heating surface; 15. Bottom heating surface; 16. Annular heating ring; 2. Inert gas passage; 3. Fan; 41. K-type thermocouple inside the furnace; 42. Thermocouple embedded in the sample; 43. K-type thermocouple inside the furnace; 5. Composite insulation layer; 6. Concrete and other samples; 7. Silicon carbide indenter; 8. Telescopic clamping column; 9. Handle; Detailed Implementation

[0026] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention.

[0027] Please refer to Figures 1-4. This utility model is a six-sided heating and pressurizing furnace for high-temperature thermal cycling, including a six-sided heating system (11, 12, 13, 14, 15, 16), a telescopic clamping column (8), a fan (3), a K-type thermocouple (41, 43), a control system, an inert gas through hole (2), and a composite insulation layer (5). The composite insulation layer is evenly distributed on the inner wall of the furnace. The furnace (1) can perform heating and cooling cycles at a controlled rate to provide different temperature fields for two concrete samples (6).

[0028] The six-sided heating system consists of five heating plates and an external annular heating ring (16) of a retractable clamping column. It is independently PID controlled. The heating system includes five sides of the heating furnace (1) with molybdenum-doped iron-chromium-aluminum heating plates evenly distributed on the bottom (15), top (16), left side (12), right side (13), front side (11), and rear side (14).

[0029] Through the above technical solutions, the heating is uniform throughout the entire heating area, improving heating efficiency. It can also maintain a stable working state for a long time in high-temperature environments, and is corrosion resistant, so it can be used in various acid and alkali corrosive environments. The surface is coated with a zirconium oxide coating, which has excellent high-temperature resistance and can remain stable at temperatures below 800℃, effectively protecting the substrate from high-temperature oxidation and corrosion. The annular heating ring (16) in the six-sided heating system is externally fitted with a retractable clamping column (8) and heats the sample uniformly through induction heating, achieving six-sided heating in conjunction with the five-sided heating.

[0030] The retractable clamping column (8) is vertically installed in the middle of the heating furnace and is driven by a servo motor through a ball screw. The retractable clamping column (8) can be controlled by the clamping system.

[0031] The retractable clamping column (8) is vertically installed in the middle of the heating furnace (1). The column is made of Inconel 718, which is corrosion resistant and can withstand high temperatures. At 700℃, the alloy can still maintain high tensile strength and fatigue resistance, making it an ideal material for high-temperature working environments. It is driven by a servo motor through a ball screw and controlled by a clamping system. The clamping end is equipped with a silicon carbide pressure head (7), which has high hardness, good wear resistance, self-lubricating properties, high temperature stability and wide temperature adaptability. The external annular heating ring (16) is located on the retractable clamping column.

[0032] (8) Externally, located 100-200mm above the pressure head, and can move together with the telescopic pressing column (8). The gap of the annular heating ring (16) is less than 1mm to prevent the telescopic pressing column from jamming due to material expansion.

[0033] The contact surface of the silicon carbide indenter (7) is a plane with a diameter of 50 mm ± 2 mm and a surface roughness Ra ≤ 0.8 μm.

[0034] The composite insulation layer (5) of the heating furnace is composed of TaC coating, zirconia aerogel and metal honeycomb support. In a high-temperature oxidizing atmosphere, a dense tantalum oxide film will be generated on the surface of the TaC coating, which acts as an anti-oxidation barrier, significantly reducing the oxygen permeation rate to the substrate. It also has high hardness and wear resistance, low friction coefficient, self-healing properties, etc. The zirconia aerogel layer has high chemical stability and corrosion resistance, and can remain stable in various harsh environments. It also has high porosity. These characteristics make it perform well in adsorption and catalysis. The particle phase and pore size of the zirconia aerogel are both at the nanoscale, which allows its microstructure to be well controlled, further improving its performance and application range. The metal honeycomb support adopts a honeycomb structure, which can effectively disperse the stress, improve the overall strength and stability of the plate, and has high flatness. In particular, the ultra-large plate can also maintain good flatness and stability. The raw materials of the metal honeycomb support are mostly aluminum alloy or stainless steel. These materials have good fire resistance. The metal honeycomb support with special surface treatment has excellent corrosion resistance and weather resistance, and is environmentally friendly and harmless.

[0035] The inert gas through hole (2) is located on the left side of the rear part of the heating furnace (1). The inert gas through hole (2) is connected to a nitrogen / argon gas source. The flow rate is controlled by a mass flow meter. There is a flap door on the top of it, which can be adjusted according to the temperature.

[0036] The blower (3) is located on the right side of the rear of the heating furnace (1). It is a high-temperature centrifugal blower with a flap door on the top, which can be adjusted according to the temperature.

[0037] The heating furnace control system includes, but is not limited to, a temperature control module, pressure control, and safety protection. Safety protection includes, but is not limited to, automatic power cut-off and alarm activation in case of over-temperature or over-pressure. The temperature control module uses independent PID control for each of the six heating sides.

[0038] The PID control algorithm has a simple structure, is easy to understand and implement, does not require a complex mathematical model, and can adapt to various types of systems, exhibiting good robustness; the clamping control is automatically adjusted by the servo motor according to the set pressure or displacement; the safety protection automatically cuts off the power and alarms when there is over-temperature or over-pressure.

[0039] There are three K-type thermocouples (41, 42, 43). One (42) is embedded in the center of the sample, and the other two (41, 43) are located inside the furnace. They are all connected to the data logger and are used to monitor the internal temperature change of the concrete (6) and record the surface temperature change of the sample.

[0040] Assembly steps:

[0041] Composite insulation layer (5) installation: The composite insulation layer (5) (composed of TaC coating, zirconia aerogel layer and metal honeycomb support) is welded to the inner wall of the heating furnace (1). The specific installation sequence is as follows: TaC coating: sprayed on the innermost layer of the inner wall of the heating furnace, with a thickness of 0.5-1mm, for high-temperature oxidation resistance. Zirconia aerogel layer: covered on the outside of the TaC coating in a modular splicing manner, with a thickness of 20mm, and fixed by high-temperature adhesive. Metal honeycomb support: adopts a stainless steel honeycomb structure, welded to the outside of the aerogel layer, with a thickness of 15mm, for dispersing thermal stress and enhancing structural strength.

[0042] Installation of the six-sided heating system (11, 12, 13, 14, 15, 16): Five-sided heating plates: Molybdenum-doped iron-chromium-aluminum heating plates are evenly arranged on the five sides of the heating furnace: bottom (15), left side (12), right side (13), front side (11), and rear side (14). The surface of the heating plates is coated with a zirconium oxide coating (thickness 50μm). Each heating plate is controlled by an independent PID module. Annular heating ring (16): It is fitted outside the telescopic clamping column (8) and installed 150mm above the pressure head (7). The gap between the annular heating ring (16) and the telescopic clamping column (8) is ≤1mm. The annular heating ring (16) uses the same molybdenum-doped iron-chromium-aluminum resistance heating element as the five-sided heating plates.

[0043] Installation of the telescopic clamping column (8): The telescopic clamping column (8) is vertically installed in the middle of the heating furnace (1), and is made of Inconel 718 alloy. It is driven by a servo motor through a ball screw. Silicon carbide pressure head (7): It is fixed at the end of the telescopic clamping column (8), and the contact surface with the sample is a circular plane with a diameter of 50 mm to ensure uniform force during clamping.

[0044] Inert gas through-hole (2) and fan (3) installation: Inert gas through-hole (2): located in heating furnace (1)

[0045] On the left rear, the through hole has a diameter of 20mm and is connected to a nitrogen / argon gas source. The flow rate is controlled by a mass flow meter (range 0-50L / min). The flap door above the through hole is driven by a stepper motor, with an opening angle of 0-90°. High-temperature centrifugal fan (3): installed on the right rear of the heating furnace (1). The impeller of the fan (3) is made of nickel-based alloy, with a rated speed of 3000rpm. The opening and closing of the flap door above is synchronized with the inert gas through hole (2).

[0046] Thermocouple arrangement: Furnace thermocouples (41, 43): fixed at the top and bottom of the heating furnace (1) respectively, 50 mm away from the sample surface. Embedded thermocouple (42): inserted into the center of the sample (6) to a depth of 1 / 2 of the sample height, and the contact is ensured by the pre-tightening force of the retractable clamping column (8).

[0047] Operating procedure: Press the sample (6), place the sample (6) to be tested in the center of the heating furnace (1), and control the telescopic pressing column (8) to apply a pre-tightening force of 5MPa; Heating and protection, set the target temperature to 600°C, start the six-sided heating and inert gas introduction; Data acquisition, record data through the embedded K-type thermocouple (42) and QTM-710 thermal conductivity probe; Rapid cooling, during the experimental cooling process, start the fan (3) and introduce inert gas to quickly cool down to the target temperature while removing gas impurities such as water vapor.

[0048] Specimen Installation and Compaction: Place the concrete specimen (6) to be tested in the center of the heating furnace, ensuring that the bottom surface of the specimen (6) is in contact with the bottom heating plate (15). Start the compaction control program, and the servo motor drives the telescopic compaction column (8) downward to apply a pre-tightening force of 5MPa and hold it for 10 seconds to ensure that the thermocouple (42) is in close contact with the specimen (6).

[0049] Heating and Data Acquisition: Set the target temperature (e.g., 600°C) and heating rate (e.g., 1°C / min), and start the six-sided heating system. Open the inert gas through-hole (2) flap door to introduce nitrogen gas (flow rate 10L / min), while simultaneously closing the fan (3) flap door. Real-time acquisition of the sample's internal temperature and thermal conductivity data is performed using a QTM-710 thermal conductivity probe and thermocouple (42), with a data recording interval of 1 second.

[0050] Rapid cooling and test termination: After reaching the target temperature, maintain constant temperature for 30 minutes to complete the thermal fatigue cycle. Start the rapid cooling program: fully open the flap door of the fan (3), increase the inert gas flow rate to 30L / min, and automatically shut off heating and gas supply when the system monitoring temperature drops below 100°C. Release the retractable clamping column (8), take out the sample (6) and export the experimental data.

[0051] The above are merely preferred embodiments of the present utility model and do not limit the present utility model. Any modifications, equivalent substitutions, or improvements made to the technical solutions described in the foregoing embodiments, or to some of the technical features, shall fall within the protection scope of the present utility model.

Claims

1. A six-sides heating and pressurized heating furnace for high-temperature thermal cycle, characterized in that: it comprises a six-sides heating system (11, 12, 13, 14, 15, 16), a telescopic compression column (8), a fan (3), K-type thermocouples (41, 42, 43), a control system, inert gas through holes (2) and a composite insulation layer (5), wherein the composite insulation layer (5) is uniformly distributed on the inner wall of the heating furnace; the heating furnace (1) can perform heating and cooling cycles at a controlled rate to provide different temperature fields for two concrete samples (6).

2. The six-sides heating and pressurized heating furnace for high-temperature thermal cycle according to claim 1, characterized in that: the six-sides heating system is composed of a five-sides heating plate and a ring-shaped heating ring (16) outside the telescopic compression column, and the heating system includes a heating furnace bottom (15), a top (16), a left side (12), a right side (13), a front side (11) and a back side (14), wherein the five sides are uniformly provided with molybdenum-doped iron-chromium-aluminum heating plates, and the surfaces are coated with zirconia coating; each heating surface of the six-sides heating system (11, 12, 13, 14, 15, 16) is independently adjusted by PID.

3. The six-sides heating and pressurized heating furnace for high-temperature thermal cycle according to claim 2, characterized in that: the telescopic compression column (8) is vertically installed in the middle of the heating furnace (1) and is driven by a ball screw through a servo motor, and the telescopic compression column (8) can be controlled by a compression system.

4. The six-sides heating and pressurized heating furnace for high-temperature thermal cycle according to claim 3, characterized in that: the ring-shaped heating ring (16) is installed outside the telescopic compression column (8) and located at 100-200 mm above the silicon carbide pressure head, and can move with the telescopic compression column (8); the gap of the ring-shaped heating ring (16) is less than 1 mm.

5. The six-sides heating and pressurized heating furnace for high-temperature thermal cycle according to claim 4, characterized in that: the contact surface of the silicon carbide pressure head (7) is a flat surface with a diameter of 50 mm±2 mm, and the surface roughness Ra is less than or equal to 0.8 μm.

6. The six-sides heating and pressurized heating furnace for high-temperature thermal cycle according to claim 1, characterized in that: the composite insulation layer (5) is composed of a TaC coating, a zirconia aerogel and a metal honeycomb support.

7. The six-sides heating and pressurized heating furnace for high-temperature thermal cycle according to claim 1, characterized in that: the inert gas through holes (2) are located on the left side of the back of the heating furnace (1) and are connected to a nitrogen / argon gas source; a flap door is provided above the inert gas through holes (2), and the opening and closing of the flap door is controlled by the heating furnace control system.

8. The six-sides heating and pressurized heating furnace for high-temperature thermal cycle according to claim 1, characterized in that: the fan (3) is located on the right side of the back of the heating furnace (1) and belongs to a high-temperature resistant centrifugal fan; a flap door is provided above the fan (3), and the opening and closing of the flap door is controlled by the heating furnace control system. ​ ​ ​ ​ ​ ​ ​ ​ 9. The six-sided heating pressurized heating furnace for high temperature thermal cycling of claim 1, wherein: The control system includes, but is not limited to, a temperature control module, a pressure control module, and a safety protection module.

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