Modeling of the tunnel kiln control system taking into account the features of the pid controller and fuzzy logic

Taking into account the non-linear, time-varying temperature characteristics of the tunnel kiln, high inertia and some uncertainty of its parameters, it’s difficult to create an accurate mathematical model and get an acceptable set of the controller of the control system. The asynchronous motor actuator of the system, which regulates the amount of gas and air to change the temperature, gives the system first-order a statism. A conventional PID controller does not provide the required quality parameters of temperature control in the entire possible range of changes in the parameters of the controlled object. Thus, the synthesis of an additional fuzzy PID controller is required to ensure the required quality of regulation. Of course, PID control and fuzzy intelligence will provide effective self-tuning of the parameters of controlled PID controllers. A simulation experiment in Matlab shows that fuzzy PID control reduces the time and magnitude of overshoot, effectively increasing the stability of the system by giving it robustness properties.

Thermal Analysis and Energy Efficiency Improvements in Tunnel Kiln for Sustainable Environment

Kiln is a prime need in the ceramics industry, where energy loss is a major part which consumes about 60% production cost through thermal energy for different applications. Higher density of fired and tunnel kiln refractory material lowers the thermal diffusivity and the proper selection of fired material minimizes the energy loss along the kiln. In particular, this research analysed the results of a heat recovery system comprised of a metallic recuperator which gives around 8% energy savings in natural gas consumption. In this work, detailed power quality analysis of low-power factor motors of a tunnel kiln was carried out and a power factor improvement solution was suggested to save electrical energy with payback period of 0.8 y. The motor operating at a low-power factor consumes more reactive power which does not produce beneficial work. A low-power factor around 0.4 causes network power loss, increases in transformer loss and voltage drops. The solution with accumulative capacitance power of 148.05 uF was installed to achieve the power factor to 0.9. Flu gas analyzer was installed to monitor the range of O2 in pre-heating, oxidation, and firing zones of the kiln which should be ≥8% and 3%, respectively. Regression analysis for thermal energy consumption of a tunnel kiln is done to find the forecast thermal energy consumption. This analysis can be used to find operational efficiency, supporting decisions regarding dependent variable of thermal energy consumption and independent variable of production. This research is very helpful for the ceramics industry to mitigate the energy loss at SMEs as well as in mass production level.

Investigation of the Robust Absolute Stability of the Tunnel Kiln Control System with Delay

The paper considers the system of automatic control of the tunnel kiln temperature conditions. The investigation of a delay influence on the transition process has been carried on. The transfer function of the object under control with interval coefficients taking into account possible effects of the parametric uncertainty has been obtained. A graphical method of representing the obtained results in the form of displaying the modified amplitude-phase characteristics on a complex plane has been applied which obviously demonstrates a robust absolute stability of the system under investigation. The simulation performed in the Matlab environment has proved the correctness of the results obtained.

Analysis of energy saving in domestic ceramic industry kilns

Ceramic industrial kiln refers to the combustion equipment for ceramic production, which generally refers to roller kiln, shuttle tunnel kiln and shuttle kiln. Roller kiln refers to the kiln with continuous firing and rotating roller as the vehicle of the billet body; Tunnel kiln refers to the kiln which adopts continuous firing and takes rail kiln car as the transport vehicle of billet body. Shuttle kiln refers to the kiln which is fired intermittently and consists of kiln car, kiln chamber and kiln door. Factors influencing energy saving of kiln include construction materials, kiln structure, combustion technology, thermal insulation performance and automation control.

BRICK FIRING PROCESS CONTROL SYSTEM

В статье приводится описание технологического процесса обжига керамического кирпича в туннельной печи. Приведено обоснование для внедрения автоматизированной системы управления туннельной печью и вариант структуры автоматизированной системы управления. The article describes the technological process of firing ceramic bricks of a tunnel kiln. The rationale for the introduction of an automated control system for a tunnel furnace and a variant of the structure of an automated control system are given.

Researches in the field of composite HCBS and of the refractory materials on their base in Al2O3‒SiO2‒SiC system. Part 4

The effect of long heat treatment (single and double firing in a tunnel kiln) of samples based on a HBCS in Al2O3‒ SiO2‒SiC-system on their indicators was studied. Samples containing 15 % SiC and 1 and 2 % Si are characterized by a significant increase (up to 9 %) an increase in porosity and a decrease in strength compared to the original samples (without SiC) after long heat treatment (120 hours in the range of 1300‒1400 oC). A significant increase in the volume of the samples is due not only to the oxidation of SiC or Si, but also to additional mullite formation. It is assumed that sequentially following the process of oxidation of SiC at a certain stage of heat treatment, the process of mullitization proceeds due to the interaction of the newly formed SiO2 in the form of cristobalite with Al2O3 bauxite. Ill. 6. Ref. 19.