Akademik Veri Yönetim Sistemi
Tezin Türü: Yüksek Lisans
Tezin Yürütüldüğü Kurum: Van Yüzüncü Yıl Üniversitesi, Fen Bilimleri Enstitüsü, Makine Mühendisliği (Yl) (Tezli), Türkiye
Tezin Onay Tarihi: 2017
Tezin Dili: İngilizce
Öğrenci: SULAIMAN ABDULLAH MOHAMMED
Danışman: Atilla Bayram
Özet:
Temperature control of systems has become an important subject in many areas, especially, in industrial operations at wide range of operating temperature. Another important field of the temperature control is the identification of mechanic characteristics of materials. This study consists of a design of temperature controlled heating and cooling system. This system, which allows operations over wider temperature ranges, will be used in a tension-compression testing machine. The heating side of the system involves basically an isolated metal box, dry resistance, voltage regulator, thermocouple, air fun, relay, amplifier, microcontroller and computer. The temperature inside the box is controlled by a feedback control. This feedback control system measures the temperature via a K-type thermocouple and uses a PID controller to compensate the errors.
The cooling process is very important for cooling the electric and electronic devices, industrial process, food production process, pharmaceutical industry and scientific laboratory. If you work on the cryogenic processes, the best method for quite lower temperatures is to use liquid nitrogen. For this system, in addition to the heating part devices, the cooling system involves an electronic valve, DC motor driver and a liquid nitrogen tank. In this side, a proportional control is used to control the temperature in accordance with the valve characteristics.
The Arduino board is used as microcontroller because it is simple, cheaper, and easy to program. All communications between the computer and the setup are made via the Arduino card. For real time implementations, the programs written on MATLAB software have shown a great success for both the communication and the control.
In this experimental study, based on the requirement, the heating and cooling processes are performed separately or sometimes both at the same time. At first, the user uploads the desired temperature profile to the computer via a program written in MATLAB. By running the program, the temperature control system starts to work. The temperature of the inside of the isolated box is measured continuously with a type-K
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thermocouple. This temperature measured by the thermocouple is converted to an analog
signal at a voltage of microvolt level. This analog signal is boosted to a millivolt level via
MAX31855 amplifier plugged into Arduino. At the same time, this amplifier converts the
analog signal to the digital one. This signal is transferred via USB to a program written
in MATLAB environment compatible with Arduino and converted a temperature in
degrees Celsius. The program also includes PID, P, and on / off controllers as software,
and tries to minimize the temperature error between measurement and reference using
one of them according to the process. For this aim, the output modified on the controller
is transmitted with USB to Arduino again. If heating of the system is required, Arduino
adjusts the temperature by changing the load of AC voltage on the heater by sending 0 to
5V DC signal to the power regulator. The cooling process is performed by adjusting the
amount of liquid nitrogen by Arduino sending +5, 0 or –5 V constant DC voltage to the
electric valve via the motor driver for a calculated time. In some cases, cooling and
heating processes can occur simultaneously to supply the desired temperature reference.
In this study, the temperature of the isolated box can be held easily between
400 oC and 100 oC . Implementing some experiments, the user defined different
reference temperature profiles are achieved on the test machine and are compared with
that of the mathematical modeling of the cooling and heating system. It is seen that the
errors are acceptable level.