A Guide to PLC and SCADA Automation in Steam Boilers
Steam Boilers are one of the most important equipment in any power plant and process industry that require constant monitoring and inspection at frequent intervals. In a steam boiler, various sections are controlled at the same time with primary sections, such as the boiler drum, a boiling section producing high-temperature water for steam generation. Excessive water level leads to improper steam generation. Steam & Drum Level is critical and difficult to measure and maintain to automate the system and reduce human errors. Precise control of the water level in the drum is an important factor that is performed by developing a PLC and SCADA system. It helps to reduce the manual operation and provide enhanced control and monitoring of the plant and process operations through a SCADA system, a centralized system for supervising the process by preparing the required data respective to process changes.
Programmable Logic Controller (PLC):
Programmable Logic Controller (PLC) is a digital computer for automation that can re-program the logic as per the users’ requirements in industries. PLC is also used for the internal storage of instruction for the function implementation such as logic, sequencing, timing, counting, and arithmetic to control through digital or analog input/ output modules.
Working of Programmable Logic Controller (PLC):
At the start of each operational cycle, the CPU brings in all the field input signals from the input signals from the module to store them into internal memory as a process of the input signal. This internal memory of the CPU is known as the process input image (PII).
The user program is available in the CPU program memory. The CPU takes the status of input from PII and processes it in the user program, and its result is stored in the internal memory of the CPU. This internal memory is called process output image. At the end of the program run, the CPU transfers the signal states in the process image output to the output module and resultantly, to the field control.
- Input-Output in PLC
- Input Layout:
- Feed Pump
- RTD Transmitter
- Level Switch
- Pressure Transmitter
- Output Layout:
- Solenoid Valve for the water inlet
- Solenoid Valve for Steam Outlet
- Heater
Supervisory Control and Data Acquisition (SCADA):
As the name suggests, SCADA stands for Supervisory Control and Data Acquisition that helps with the supervisory level as it is not a complete control system. SCADA is used for monitoring and controlling plants or equipment. The control may be automatic or managed by operator commands. The data acquisition is completed by the PLC’s scanning the field inputs connected to the PLC that is usually at a fast rate. The central host scans the PTU’s at a slow rate and the data is processed to detect alarm conditions. If an alarm is present, it is displayed on special alarm lists.
PLC and SCADA in Industries:
PLC and SCADA are used to develop and implement boiler automation. Various sensors measure the temperature, pressure, and water level. The parameters are assessed through SCADA, and the operation is controlled by using PLC. The entire arrangement shuts down if the temperature and pressure reach a predetermined value and the automatic check valve opens to discharge the steam and pressure. An emergency alert is activated, and automatic check valves are opened to avoid any hazardous failure. Boiler control is a crucial part of any process plant.
The steam boiler in a process plant or power generation project is controlled through a variety of methods. The method to be used is determined by several objectives such as rising profit, increased efficiency, superior quality, and other factors that are dependent on the industry. Boiler automation has become vital for meeting the primary goal of providing easy operation to these facilities and the needs of the industries. The changes that are consistently taking place in the industrial sector are partially the result of boiler automation. The automation process, which is gradually assuming its position in all process plants throughout the world, has been given priority. It has prepared itself to examine the critical components of the entire process operation, along with their implementation and any difficulties that may arise.
Conclusion:
Rakhoh Boilers are renowned for their efficient and reliable steam boilers, waste heat recovery boilers, thermic fluid heaters, and boiler accessories since their inception in 1983. We also provide excellent boiler services like energy audit, steam trap assessment, boiler automation, annual boiler maintenance, fuel conversion, etc., to enhance the efficiency and productivity of steam boilers.
Learn more about our products and services at www.rakhoh.com
- Published in Boiler
Boiler Automation System in Process Industries with PLC and SCADA
With the rapid development of industries, it has become essential for process plants to operate with precision to ensure the manufacturing of high-quality products. Efficiency and reliability have always been a priority in the case of industrial boilers. Yet, there is a considerable difference between the direct and indirect efficiency in boilers due to various losses occurring during operation. An interesting fact to note is that the boiler efficiency is usually rated between 73% and 77%, but the efficiency achieved ranges between 50% and 55%. The ideal solution to retain maximum efficiency and to bridge the gap between direct and indirect efficiency is Boiler automation.
Boiler Automation:
Boiler operations in process plants are generally monitored and handled by the plant personnel. Operations such as fuel feeding, maintaining the boiler accessories, etc., if performed manually may cause errors and loss of efficiency. For instance, while feeding fuel in the boiler, it must be assured that it is neither overfeed nor underfeed, leading to unburned fuels, improper combustion, and overall reduced efficiency of the boiler.
Boiler automation has been introduced in many industries that have witnessed a remarkable increase in efficiency and productivity. With the aid of sensors, boiler automation alerts the concerned plant manager, thereby reducing the chances of manual error.
Role of Boiler Automation:
Boiler Automation instantly alerts the operators of any practice that may lead to reduced efficiency with the help of sensors. It results in preventing the operations or errors that may cause losses. Here are some of the examples that can be avoided with boiler automation alerts,
- Adjustment of ID Fan damper to ensure an appropriate amount of air is provided to the furnace to keep stack losses at a minimum
- Uniform fuel feeding on fuel bed to avoid overfeeding in some sections that may result in unburned fuels and incomplete combustion
- Cleaning of boiler tubes to prevent the formation of soot layer that would reduce the heat transfer rate
- Improving water quality to ensure reduction in blowdown losses that consequently increases the boiler efficiency
- Closing of feed door as it is neglected and remains open in manual operations. It causes the ambient air of room temperature to enter the furnace that gets released carrying heat, eventually causing stack losses.
The two main components of a Boiler automation system are PLC or Programmable Logic Controller and SCADA or Supervisory Control and Data Acquisition.
Programmable Logic Controller (PLC):
Programmable Logic Controller, simply known as PLC is a computer system that is designed for operation and control in an industrial setting. PLC consists of CPU, memory, inputs and outputs, and software (relevant to industrial operation) and performs continuously as per the requirement of the processing operations. PLC operates industrial functions like manufacturing the assembling line in the process plant, waste management, etc.
Working of PLC:
The primary objective of PLC systems is scanning that includes the following process:
- Cycling and monitoring of time by the operating system
- CPU reads the input module data and checks the status of the inputs
- CPU begins to execute the application program
- Internal Diagnosis and Communication Tasks are performed by CPU
- Writing of data in the output module based on program results
Applications of PLC:
Programmable Logic Controller has a wide range of applications in various industries. Some of them include:
- Paper and Packaging Industry
- Cement Industry
- Glass Industry
- Process Automation Plants
- Thermal Power Plants
Supervisory Control and Data Acquisition (SCADA):
SCADA stands for Supervisory Control and Data Acquisition is a process control system that facilitates high-level supervision and control by using computers, network data communications, and Human Machine Interfaces (HMI). The system functions with other devices like Programmable Logic Controller (PLC) and Proportional–Integral–Derivative (PID) Controller. It manages the operation of industrial process plants and equipment.
SCADA Supervises the operations taking place in the process plant and Controls it by interacting with HMI. The information and data collected are analyzed in real-time and recorded. The SCADA system can function virtually, enabling the operator or manager to keep a track of the process from the control room. The system includes both hardware and software. The software is installed on the computer for analysis, and the hardware receives the input data that feeds it to the system for further assessment. It also includes a hard disk that records and stores the data which can be later printed if required.
Working of SCADA:
Supervisory Control and Data Acquisition system is a collection of hardware and software components that manages the functions of the processing plants. Some of the important operations of SCADA include:
- Monitoring and Gathering Data in real-time
- Recording information and data in a log file
- Communicating with control stations through Human Machine Interface (HMI)
- Controlling of manufacturing process virtually
- Storing of Information and Reports
Applications of SCADA:
- Power Generation, Transmission, and Distribution
- Manufacturing Units
- Steam Generation
- Process Operations in Industries like Food, Beverages, Oil, and Gas
- Wastewater and Sewage Management
Rakhoh Boilers has been manufacturing efficient steam boilers since its formation in 1983 while ensuring a balance between advancement and sustainability. We provide installation service of a boiler automation system for industrial boilers along with training to operate it. Boiler automation and control system is beneficial to process plants as it assures,
- High Efficiency
- Conservation of Natural Resources
- Boiler Safety
- High Productivity
- Longer Boiler Lifespan
Learn more about our products and services at www.rakhoh.com
- Published in Boiler