10+ KEPCO Plant Service & Engineering Interview Questions and Answers

Heat exchanger is a device used to transfer heat between two or more fluids of different temperatures.

• Types of heat exchangers include shell and tube, plate and frame, and finned tube.

• The type of fluid being used determines the material of construction for the heat exchanger.

• Baffles are plates or rods placed inside the heat exchanger to direct the flow of fluid and increase heat transfer efficiency.

Centrifugal pump is a mechanical device used to transport fluids by converting rotational kinetic energy to hydrodynamic energy.

• Centrifugal pump consists of an impeller, casing, and inlet/outlet ports.

• The impeller rotates and creates a centrifugal force that moves the fluid towards the outlet.

• NSPH stands for Net Positive Suction Head and is a measure of the pressure required at the inlet to prevent cavitation.

• Cavitation occurs when the pressure at the inlet drops below the va...read more

Reflux ratio is the ratio of liquid reflux to the distillate and affects the separation efficiency of a distillation column.

• Reflux ratio is a key parameter in distillation column design and operation.

• It is defined as the ratio of liquid reflux to the distillate.

• Increasing the reflux ratio increases the purity of the distillate but decreases the distillate flow rate.

• Decreasing the reflux ratio decreases the purity of the distillate but increases the distillate flow rate.

• Optima...read more

Reflux ratio is the ratio of liquid reflux to the distillate. Optimum reflux ratio is the minimum reflux ratio that gives the desired purity.

• Minimum reflux ratio is the ratio at which the desired purity is achieved.

• Reflux ratio is important in distillation process to achieve desired purity.

• Optimum reflux ratio is the minimum reflux ratio that gives the desired purity.

• Reflux ratio can be calculated using the McCabe-Thiele method.

• Reflux ratio affects the efficiency of the disti...read more

Pump is a mechanical device that moves fluids from one place to another. Valve is a device that controls the flow of fluids.

• Types of pumps include centrifugal, positive displacement, and axial flow pumps.

• Types of valves include gate, globe, ball, and butterfly valves.

• Pumps are used in various applications such as water supply, oil and gas, and chemical processing.

• Valves are used in industries such as power generation, oil and gas, and water treatment.

SCADA is a centralized system used to monitor and control industrial processes, while DCS is a distributed system that allows for control at a local level.

• SCADA is used for monitoring and controlling processes in industries such as power plants, water treatment facilities, and manufacturing plants.

• DCS allows for control at a local level, with each control unit being responsible for a specific area of the process.

• SCADA systems typically have a centralized control room where op...read more

PLC is used for discrete control of machines, while DCS is used for continuous control of processes.

• PLC is typically used for controlling individual machines or processes in manufacturing, automotive, and packaging industries.

• DCS is commonly used in industries such as oil and gas, chemical, and power generation for controlling continuous processes.

• PLCs are more cost-effective for small to medium-sized applications, while DCSs are better suited for large-scale operations.

• PLCs ...read more

Logic gates are electronic devices that perform logical operations based on input signals.

• Logic gates are the building blocks of digital circuits.

• They take one or more binary inputs and produce a single binary output based on a specific logic function.

• The basic types of logic gates include AND, OR, NOT, NAND, NOR, XOR, and XNOR gates.

• Each logic gate has a corresponding truth table that shows the output for all possible input combinations.

• For example, the truth table for an AN...read more

Parameters measured in engineering and methods used for measurement

• Parameters measured include dimensions, temperature, pressure, flow rate, and electrical properties

• Methods used for measurement include rulers, thermocouples, pressure gauges, flow meters, and multimeters

• Calibration of instruments is important for accurate measurements

• Data acquisition systems can be used for continuous monitoring and recording of measurements

An electromagnetic flowmeter is a device used to measure the flow rate of conductive liquids in a pipe by inducing a magnetic field and measuring the voltage generated.

• Works based on Faraday's law of electromagnetic induction

• Suitable for measuring flow rates of conductive liquids like water, acids, and slurries

• Commonly used in industries such as water treatment, chemical processing, and food & beverage

• Provides accurate and reliable measurements even in harsh environments

• Not s...read more

A distillation column is a vertical vessel used for separating a mixture of liquids into its individual components.

• It works on the principle of differential boiling points of the components in the mixture.

• The mixture is heated and vaporized, then the vapor rises up the column and condenses on the trays or packing material.

• The condensed liquid is then collected and separated into its individual components.

• Distillation columns are commonly used in the chemical, petrochemical, a...read more

4-20mA signal is a standard current loop used in industrial control systems.

• 4-20mA signal is commonly used for transmitting analog signals in industrial automation.

• The signal range of 4-20mA allows for easy detection of faults in the system.

• It is a robust and reliable method of signal transmission, less susceptible to noise compared to voltage signals.

• Devices like sensors, transmitters, and controllers in industrial settings often use 4-20mA signal.

• 4mA represents the lowest v...read more

T-x-y diagram is a graph that shows the phase behavior of a mixture of three components.

• T-x-y diagram is used in chemical engineering to analyze the behavior of a mixture of three components.

• It shows the relationship between temperature, composition, and pressure.

• The diagram is used to determine the conditions under which a mixture will be in a single phase or multiple phases.

• It is also used to determine the composition of each phase in a mixture.

• An example of a T-x-y diagram...read more

MC Thele diagram is a graphical representation of the relationship between the main characteristics of a control system.

• MC Thele diagram is used to analyze and design control systems.

• It shows the relationship between the main characteristics of a control system, such as stability, speed of response, and steady-state error.

• The diagram consists of two axes, one representing the gain of the system and the other representing the phase shift.

• The intersection of the two axes repres...read more

Heat exchangers are devices used to transfer heat between two or more fluids, without them mixing together.

• There are three main types of heat exchangers: shell and tube, plate, and finned tube.

• Shell and tube heat exchangers consist of a shell with tubes running through it, allowing one fluid to flow through the tubes while another flows over the tubes.

• Plate heat exchangers use plates to separate the fluids and transfer heat between them.

• Finned tube heat exchangers have tubes ...read more