The final year students of the program of B.Sc. in Electrical and Electronic Engineering (EEE) of the Department of Electrical and Electronic Engineering (EEE) of Green University of Bangladesh took part in a day-long study tour to the Ghorashal Thermal Power Station on 15 June 2015. The prime objective of this tour was to help the students to know about power plant and its operational, maintenance and management. Twenty five (25) students including four (4) female students led by Prof. Dr. Engr. Muhibul Haque Bhuyan, Chairperson of EEE Department participated in the tour. Besides, two (2) other faculty members of the EEE Department, Engr. Robiul Hossain Md. Raffi, Lecturer and Engr. Md. Badruddoja Majumder, Lecturer also joined with the participating students. They guided the students during the day-long study tour.
Ghorashal Thermal Power Station is the biggest power plant in Bangladesh located at Polash, Narshingdi with installed generation capacity of 950 MW. It has 6 power generating units with power generation capacity ranging from 55 MW to 210 MW per unit. All the generators are run by steam turbines.
The tour comprised three parts. At first, the students went to observe the power generation units where the Engineers of the power station briefly explained the working principle of the thermal power station and then demonstrated its operation. One unit of the generator was out of order right now. So, both generator and turbines were open and students were able to observe all the opened parts and have huge practical idea about various parts of alternator and steam turbine. After that they visited the electrical control room and then they observed the mechanical control room and boiler section. At last, they observed the sub-station.
At electrical control room, the students observed many control panels, such as, control panels for 230 kV, 132 kV, 33 kV and 11 kV bus bars, switch gears, isolator control knobs, breaker operation knob, ammeter, voltmeter, frequency meter, power factor meter etc. The sub-station can be controlled properly from the control room.
Then the students went to the mechanical control room where they observed how the mechanical parameters like boiler’s flow rate, steam flow to the turbine, flame etc. is controlled. Then they observed the boiler, water treatment plant, steam turbines, governor, cooling system, economizer, super-heater, re-heater and other mechanical components of the power plant.
At last, the students observed the sub-station that is consist of several electrical equipment like power, auxiliary transformers and distribution transformers, protection devices like isolators, circuit breakers, HV cables, PTs, CTs, earthing and lightning arresters. The generation voltage is around 11-15 kV, which is converted to 132 kV or 230 kV for transmission. In sub-station, there are parallel bus bar systems available. In this sub-station, three types of breakers, such as, vacuum, SF6 and air circuit breakers, are available.
At the end of the day, students came back to Dhaka with practical experiences of power plant through this study tour. This was a very effective tour for both teachers and students. Their theoretical knowledge is supplemented with this study tour.