Basic concepts related to boiler operation include various definitions of boiler load and operation control of the boiler body. The relevant concepts and definitions are briefly described as follows.
(1) Boiler rated output (BRL).
The boiler output power that matches the rated output (TRL) of the turbine generator set under rated steam parameters and feed water temperature conditions.
(2) Boiler maximum continuous output (BMCR).
The maximum continuous output power specified to match the maximum output of the turbine (VWO).
(3) Boiler minimum stable combustion load.
The minimum stable combustion load of the boiler without auxiliary fuel is usually expressed as the ratio of the minimum stable combustion load to the maximum continuous output of the boiler, that is:
Minimum stable combustion load rate = (minimum stable combustion load without auxiliary fuel/BMCR) × 100%
(4) Boiler total fuel trip (MFT).
When a generator set encounters a dangerous operating condition that endangers the safety of the unit, all fuel entering the furnace, including the fuel for the igniter, is cut off. This is part of the main function of the furnace safety monitoring system.
(5) Single-side auxiliary machine failure load reduction operation (RB).
Single-side auxiliary machine failure load reduction operation is a control measure taken for the failure of the main auxiliary machine of the unit. Single-side auxiliary machine failure load reduction operation refers to a measure to quickly reduce the unit load when one of the main auxiliary machines (such as blowers, induced draft fans, and water pumps) in the double-row setting fails and stops working, and the unit cannot carry the current load. It can also be extended to a method of quickly reducing the unit load when one of the multiple main auxiliary machines (such as coal mills) fails and is disconnected.
(6) Unit fast load reduction (FCB).
Unit rapid load reduction refers to a control measure in which the steam turbine unit is disconnected from the power grid when operating above a certain load due to internal or external power grid failure, and all external power supply loads are removed and the boiler is kept running at the minimum load, maintaining the automatic control function of the generator running with plant power; or when the steam turbine or generator is disconnected, the boiler does not stop running. According to the different operating requirements of the FCB unit, it can be divided into two different operating modes: 5% FCB, which is the mode of unit operation with plant power alone; 0% FCB, which is the mode of shutdown without stopping the boiler.
(7) Furnace safety monitoring system (FSSS).
The furnace safety monitoring system is a protection and control system that ensures that all equipment in the boiler combustion system is safely started, stopped, and cut in according to the prescribed operating sequence and conditions, and can quickly cut off all fuel (including ignition fuel) entering the boiler furnace under critical conditions to prevent destructive accidents such as deflagration, explosion, and implosion, so as to ensure the safety of the furnace. The furnace safety monitoring system includes the furnace safety system and the burner control system.
(8) Boiler burner control system.
The boiler burner control system is a control system that starts, stops, and switches the boiler ignition system or burner according to instructions or boiler load changes, in accordance with the specified operating sequence and conditions. In the intermediate storage pulverizing system, the burners are switched in single or in pairs; in the direct-blowing pulverizing system, a coal mill and auxiliary equipment are controlled to start and stop.
Basic concepts related to boiler operation include various definitions of boiler load and operation control of the boiler body. The relevant concepts and definitions are briefly described as follows.
(1) Boiler rated output (BRL).
The boiler output power that matches the rated output (TRL) of the turbine generator set under rated steam parameters and feed water temperature conditions.
(2) Boiler maximum continuous output (BMCR).
The maximum continuous output power specified to match the maximum output of the turbine (VWO).
(3) Boiler minimum stable combustion load.
The minimum stable combustion load of the boiler without auxiliary fuel is usually expressed as the ratio of the minimum stable combustion load to the maximum continuous output of the boiler, that is:
Minimum stable combustion load rate = (minimum stable combustion load without auxiliary fuel/BMCR) × 100%
(4) Boiler total fuel trip (MFT).
When a generator set encounters a dangerous operating condition that endangers the safety of the unit, all fuel entering the furnace, including the fuel for the igniter, is cut off. This is part of the main function of the furnace safety monitoring system.
(5) Single-side auxiliary machine failure load reduction operation (RB).
Single-side auxiliary machine failure load reduction operation is a control measure taken for the failure of the main auxiliary machine of the unit. Single-side auxiliary machine failure load reduction operation refers to a measure to quickly reduce the unit load when one of the main auxiliary machines (such as blowers, induced draft fans, and water pumps) in the double-row setting fails and stops working, and the unit cannot carry the current load. It can also be extended to a method of quickly reducing the unit load when one of the multiple main auxiliary machines (such as coal mills) fails and is disconnected.
(6) Unit fast load reduction (FCB).
Unit rapid load reduction refers to a control measure in which the steam turbine unit is disconnected from the power grid when operating above a certain load due to internal or external power grid failure, and all external power supply loads are removed and the boiler is kept running at the minimum load, maintaining the automatic control function of the generator running with plant power; or when the steam turbine or generator is disconnected, the boiler does not stop running. According to the different operating requirements of the FCB unit, it can be divided into two different operating modes: 5% FCB, which is the mode of unit operation with plant power alone; 0% FCB, which is the mode of shutdown without stopping the boiler.
(7) Furnace safety monitoring system (FSSS).
The furnace safety monitoring system is a protection and control system that ensures that all equipment in the boiler combustion system is safely started, stopped, and cut in according to the prescribed operating sequence and conditions, and can quickly cut off all fuel (including ignition fuel) entering the boiler furnace under critical conditions to prevent destructive accidents such as deflagration, explosion, and implosion, so as to ensure the safety of the furnace. The furnace safety monitoring system includes the furnace safety system and the burner control system.
(8) Boiler burner control system.
The boiler burner control system is a control system that starts, stops, and switches the boiler ignition system or burner according to instructions or boiler load changes, in accordance with the specified operating sequence and conditions. In the intermediate storage pulverizing system, the burners are switched in single or in pairs; in the direct-blowing pulverizing system, a coal mill and auxiliary equipment are controlled to start and stop.