Purpose of the system:
The automated control system (ACS) ensures the receipt of actual data in a continuous mode throughout the entire life of the concentrations and volumes of emissions of pollutants and greenhouse gases, processing and registration of the information received.
Description of the system:
The ASK consists of::
- Subsystems of flue gas sampling and transportation;
- Subsystems for measuring the volume flow of flue gases;
- Subsystems for measuring the dust content of flue gases;
- Flue gas analysis cabinet;
- Server cabinet;
- ARM of an environmental engineer.
Functionality:
- Analysis of the composition and quantity of exhaust gases and dust from the power plant;
- Collection and transmission of emission data;
- Formation of environmental reporting with increasing accumulation of data archive for calculating the payment of environmental tax on actual emission indicators;
- Data exchange with the enterprise management system.
Subsystem of flue gas sampling and transportation
The gas sample is taken by a sampling device. The sampling device is equipped with a filter and a heating system with an independent temperature controller and a reverse purge system. The sample is transported via a heated line. Reliable sample preparation ensures the operability and long-term operation of the system as a whole.
Subsystem for measuring the volume flow of flue gases
The ultrasonic flow measurement system is based on the principle of phase difference of sound signals and constantly monitors the speed and flow of gaseous waste. The measuring heads of the flow meter are built into the chimney in such a way that the vector component of the gas flow coincides with the direction of sound propagation. Ultrasonic transducers continuously emit and receive short pulses. Temperature and pressure sensors allow you to take into account the influence of external factors on the flow measurement and allow you to measure the standard volumetric flow.
Subsystem for measuring the dust content of flue gases
Dust measurement is based on the principle of measuring the scattering coefficient. The laser diode illuminates dust particles in the gas stream with modulated light in the visible range. The light scattered by the particles is perceived by a highly sensitive measuring receiver, amplified and transmitted to the measuring channel of the microprocessor, which is the central element of the electronic unit for measuring, controlling and processing results.
Flue Gas Analysis Cabinet
The gas analysis cabinet is a housing with a viewing door. Inside the case, analytical equipment and devices for protecting and controlling the ASC of the chimney are located. The gas-analytical system allows real-time monitoring of the main components of gorenje gases (CO, CO2, NO, NO2, SO2, O2).
The calculation of the emissions tax is carried out on the basis of monthly reporting data based on the results of measurements of the amount of emissions using the ASC.
The system is designed for environmental monitoring of emissions from the source of emissions No. 1
Functionality: Real-time emission control system performs:
- Measurement of the concentration of CO, CO2, NO, SO2, O2;
- Measurement of flue gas velocity (volume flow), temperature and pressure;
- Comparison of concentrations (mg/m3) of CO, NO, SO2 with MPC (maximum permissible concentrations) of these substances;
- Control of emissions (mg/s) of CO, NO, SO2 and comparison with their MPI (maximum permissible emissions);
- Data transfer to the local computer network of the station;
- Data visualization;
- Archiving of data with a cumulative total;
- Preparation of a commercial report for emissions payments.
Subsystem for measuring flue gas flow:
The subsystem for measuring flue gas flow includes a computing unit of the DURAG flow meter – two measuring heads, a unit for purging the measuring heads with air, a temperature sensor and a flue gas pressure sensor.
The DURAG ultrasonic contactless system is used to measure flue gas flow. The ultrasonic flow measurement system is based on the principle of phase difference of sound signals and constantly monitors the speed and flow of gaseous waste.
Two flow meter sensors were installed directly into the chimney, which operate both in the mode of a sound receiver and a sound transmitter. The output signal of the flow meter is the total standard volume of emissions of cubic meters per hour, as well as the speed, pressure and temperature of the gas at the measuring point.
Temperature and pressure sensors allow you to exclude the influence of external factors and allow you to measure the standard volume flow.
Data collection and transmission device
The data acquisition and transmission device (USPD) is designed to create a hierarchical structured multifunctional automated information and measurement system for commercial emissions accounting of an enterprise with the functions of distributed storage and processing of information based on the Siemens 315-2DP controller, the Siemens ET-200s distributed peripheral station. The USPD automatically collects data on the chemical composition of the gas sample and the standard volume flow rate, as well as monitoring the parameters of the subsystem health status signals (the need to clean /replace sample preparation filters, measurement errors, the need for calibration). At the same time, the reliability of the data obtained is evaluated, and hardware and logical errors are diagnosed. Data can be displayed not only in the data collection and transmission cabinet, but also on any computer connected to the local network of the enterprise. The gas analysis cabinet (SHG) and the data collection and transmission cabinet (SHSPD) are located in the outdoor installation module (container block) at the base of the chimney.
This room provides the necessary climatic indicators, has sufficient free space and height to accommodate equipment and provides additional protection for cabinets with expensive equipment.
Also, the Gomel CHP-2 implemented a system for measuring oxygen concentration in the shunt pipes of boilers based on the Oxymitter 4000 gas analyzer, which uses an electrochemical sensor based on zirconium oxide. The measuring probe is installed directly into the shunt tubes of the position. The special design of the probe allows the analysis of the sample without preliminary sample preparation. The data received from the Oxymitter 4000 gas analyzers are transmitted to electronic recorders installed on central control panels and allow real-time data on the oxygen content in the flue gas to be obtained and thereby allows monitoring and controlling the fuel combustion process.
Implementation results:
The introduction of an automated emission control system (ACS) allowed:
- Take into account emissions of harmful substances by actual indicators, and not by calculation method, as it was done before;
- Generate the necessary reports on emissions of harmful substances into the atmosphere with an increasing accumulation of data;
- Transmit current data to the workplaces of the environmental engineer, the shift supervisor of the station, as well as reports on emissions to the local network of the enterprise;
- Generate commercial emissions reports;
- Reduce emissions of harmful substances into the atmosphere and, accordingly, reduce the fee for emissions, increase the reliability and efficiency of the main equipment.
