Tendenza di sviluppu di l'equipaggiu termale cumpostu di alta temperatura avanzata

The so-called composite material refers to a multiphase new material system prepared by two or more component materials using a certain process technology, and its comprehensive performance is better than the respective component materials. Advanced composite material refers to the composite material composed of high performance reinforcement such as carbon fiber, aramong and other high performance heat resistant polymers, including metal base, ceramic base and carbon (graphite) base and functional composite material. Each component material of composite material plays a synergistic role in performance. Compared with traditional materials, it has high specific strength, light weight, high specific modulus and good fatigue resistance. And good vibration damping performance and many other advantages, widely used in the national defense industry, aerospace, automobile manufacturing and other fields.

With the development of high-tech fields, especially with the development of advanced aerospace equipment technologies such as ultra-high-speed missiles, large launch vehicles, space capsules, supersonic fighters, and new generation of large aircraft, and with the improvement of people's awareness of resource conservation and environmental protection, the requirements for advanced composite materials are gradually increasing. Therefore, the high temperature thermal equipment of advanced composite materials is more and more demanding. As the so-called "generation of materials, generation of equipment", the development history of advanced composite materials shows that the emergence of a generation of new materials supports the research and development of a generation of new equipment, and the development of a generation of new equipment leads the application of a generation of new materials.

The preparation process of high temperature resistant advanced composite materials is also constantly introduced, but no matter what kind of preparation process, thermal equipment must be used. In the preparation process of carbon fiber, carbon/carbon composite materials and most ceramic matrix composite materials, there is a process of inorganic or ceramic raw materials, and this process must be completed by special thermal equipment to avoid the oxidation of non-oxide components such as carbon fiber, carbon matrix, organic raw materials at high temperatures. For metal matrix composites, heat treatment processes such as vacuum annealing, quenching and carburizing are often required in the preparation process, and these processes also require special thermal equipment to complete. It is just that the structure, principle and function of the thermal equipment used in different processes are different. For example, the Muffle furnace used for firing SiO2f/SiO2 composite materials and components prepared by Sol-gel process is relatively simple in structure, principle and function; For example, the CVI furnace used in the preparation of Cf/SiC composite materials and components by the CVI process has a much more complex structure, principle and function. However, whether these thermal equipment is simple or not, their performance level often determines the performance level of the prepared materials and components, which is the so-called "generation of equipment, generation of materials".

In order to support the development of equipment technology in advanced aerospace and other fields, at the same time, in order to help save resources and environmental protection, the performance of advanced composite materials continues to break through, the corresponding preparation process has been continuously improved, which also led to the progress of advanced composite thermal equipment technology, and towards large-scale, integrated, automated, intelligent and green direction.

With the continuous development of the aerospace industry and the increasing demand for light weight, reliability and comfort, it is expected to combine multiple components into a whole and reduce the number of components, which makes the size of aerospace components become larger and larger, and the large-scale of thermal equipment becomes more and more necessary. For example, the appearance size of an advanced composite component of an aerospace vehicle is as large as 3000*3000*4000mm, and the corresponding thermal equipment shell size is as large as 6000*6000*10000mm.

The traditional thermal equipment manufacturing component size is limited, and the component relies on splicing, its stability is poor, and it can not be better mass production. Large-scale thermal equipment can produce large components, which provides the possibility to meet the needs of the aerospace industry. At the same time, after large-scale thermal equipment, more components can be manufactured in one production, which can improve production efficiency and reduce costs.

In the process of large-scale research and development of thermal equipment, the optimization of equipment temperature field and flow field through simulation is an important development trend, and it is also an important technical means to adjust and optimize the thermal expansion coefficient of equipment related components, solve the problem of increasing the absolute amount of thermal expansion and the expansion failure of heating elements at high temperatures.

Another trend in the development of thermal equipment is integration, that is, the thermal equipment of different processes of related materials is integrated into one/set of equipment. Integration can reduce the heating and cooling process of each process, reduce energy consumption, improve production efficiency, and even realize the transformation from intermittent production to continuous production, and improve product performance. For example, carbon fiber preparation generally includes pre-oxidation, low temperature carbonization, high temperature carbonization, graphitization and other heat treatment processes. In the traditional process, the thermal equipment of these processes is independent of each other, so the whole process is intermittent, obviously, each process has a heating and cooling process, and there is also a transfer process between the processes. If the thermal equipment of these processes is organically combined and integrated into one/set of thermal equipment to form continuous production equipment, it not only improves production efficiency, but also greatly saves the heat energy consumed and wasted by the original thermal equipment of each process due to heating and cooling. Not only that, the integrated continuous production, but also effectively eliminate the adverse effect of air during the transfer process between the traditional process processes on the quality of fiber, improve the quality of fiber.

The function of the product is divided into modules, each module is designed separately, and the universality of the module is improved, but the connection between the modules is simple and efficient. This reduces the product design cycle, improves the efficiency of product development, and improves the overhaul and maintenance efficiency during the use of equipment, reducing the user's overhaul and maintenance costs. The difficulty of the integrated development of thermal equipment is that each process does not affect each other. The unreacted raw materials or incomplete products of the previous process cannot affect the process of the next process, or the products of the process cannot be returned to the previous process. At the same time, if different atmospheres are protected between each process, mixing and other effects cannot be produced between different atmospheres.

Thermal equipment adopts automatic control system, in the production process, temperature, atmosphere, pressure and other parameters are automatically controlled by the equipment, reducing the manual operation and man-made deviation or misoperation, improve the accuracy of the production process. In addition, compared with manual conveying of materials with traditional thermal equipment, automatic weighing of materials, feeding, discharging and automatic conveying of materials between each process reduce the influence of human factors on product quality and improve quality stability. At the same time, the reduction of manual operation is conducive to reducing production safety hazards. In addition, with the development of new materials industry and the application of various new processes, the requirements for operators are getting higher and higher. The improvement of equipment automation and the simplification of equipment operation can reduce the technical requirements, management requirements and training cycles for personnel in the production process, and reduce labor costs.

On the basis of automation, it is necessary to further develop in the direction of intelligence. The intelligent technology of thermal equipment should include: self-awareness (advanced sensing technology, Internet of Things), intelligent analysis and decision-making (cloud computing, intelligent control), self-learning and self-adaptation (big data prediction, diagnosis and optimization).

For intelligent thermal equipment, first of all, it must have self-sensing function, that is, through advanced sensing technology, real-time online accurate detection of various relevant parameters in the equipment itself and advanced composite material preparation process, and even including the relevant properties of the prepared materials and components. And the inspection of the perceived data is transmitted to the equipment's data intelligent processor or equipment manufacturer's data processing center. Then the data intelligent processor or the data processing center of the equipment manufacturer analyzes these data through cloud computing, and automatically issues adjustment instructions to the relevant equipment agencies according to the relevant analysis results, and the relevant agencies achieve parameter adjustment according to the instructions. Finally, intelligent equipment should have self-learning and adaptive ability, that is, intelligent thermal equipment can be based on the initial and final performance parameters of materials or components to be processed, can be based on big data prediction, diagnosis and optimization, automatically give reasonable equipment and process parameters, heat treatment of materials and components.

In addition, the intelligence of thermal equipment should also include the information of equipment. That is, it is necessary to digitize and even visualize the equipment information, connect the equipment to the network, establish the Internet of things, and store the collected data to the equipment data center to improve the intelligent analysis and decision-making and self-learning and adaptive ability and level of intelligent thermal equipment.

The comprehensive development of thermal equipment should not only pay attention to the performance of equipment and contribute to the improvement of the performance and production efficiency of materials and components, but also maximize the practice of "high efficiency, low energy consumption, low emission, zero emission" green product manufacturing concept under the current development trend of vigorously advocating industrial manufacturing, and strive to optimize and improve the equipment design and manufacturing process. While meeting the requirements of the material and component preparation process, it is necessary to improve the energy utilization efficiency as much as possible and reduce the damage and pollution of the human body and the environment caused by the waste gas generated during the material preparation process.

For example, in the process of designing and manufacturing thermal equipment, Hunan Dingli Technology Co., Ltd. optimized the furnace structure, heating element shape and distribution by means of computer-aided design and simulation, which improved the energy saving and temperature equalization of the equipment. At the same time, through the calculation and design of heat transfer, the new heat-insulating lining structure is adopted to reduce the heat dissipation and heat storage of the lining, improve the uniformity of the furnace temperature, and reduce the surface temperature of the outer wall of the equipment furnace shell by 20℃. In addition, through the use of infrared radiation coating and other new energy-saving materials, and at the same time the use of lightweight brick, refractory fiber, composite lining, reduce the heat radiation of the outer wall of the furnace shell, reduce heat loss, shorten the heating time. The lining material is made of lightweight refractory and thermal insulation ceramic fiber board. Compared with the traditional all-brick structure lining, the heat loss and heat storage loss are greatly reduced. Fiber products are light in weight and small in specific heat capacity, which can reduce the thickness of the insulation layer by about 1/3, so the total weight is reduced by about 30%. In addition, the furnace lining of the equipment adopts the whole fiber structure, the material will not appear in the heat treatment process of the furnace temperature fluctuation phenomenon, energy saving about 30% than the traditional furnace structure, optimize the tail gas treatment technology, improve the thermal efficiency, reduce the exhaust gas emission. Finally, according to the composition of the tail gas produced in the process, the corresponding tail gas treatment device is designed, and the harmful substances contained in it are treated in turn to realize the harmless emission of the tail gas.

"If you want to do a good job, you must first sharpen your tools", the development of equipment manufacturing technology has become a key factor in the promotion and transformation of China's new material industry. Accelerating the development of advanced composite materials related thermal equipment manufacturing technology is of great significance to promote the technological progress of composite materials industry and realize the transformation from "Made in China" to "created in China".