ABB PFXC141 power supply unit to be installed on the wall

Description

PFXC 141 are normally used for connection of Pressductor® load cells where the distance between load cells and tension electronics is long. The cables fixed to the load cells and the cable to the control unit are to be connected to the junction box. The junction box PFXC 141 shall be mounted adjacent to the load cells and located in a protected position easily accessible for service.

3BSE018741R15 Length:15M
3BSE018741R30 Length:30M
3BSE018741R50 Length:50M
PFXC141 Junction Box

Distributed Control System (DCS) is a comprehensive product of computer, automatic control technology, and network communication technology. It is based on the design concept of decentralized control, decentralized danger, centralized operation and management, and adopts a multi-level hierarchical, cooperative and autonomous structural form, adapting to the requirements of modern production and enterprise management.

With the continuous development of productivity in China and the continuous improvement of scientific and technological level in production process automation, DCS control systems are widely used in newly built thermal power plants in China, and thermal power plants that previously used conventional control have also undergone DCS transformation. With the continuous development of DCS control systems and the continuous improvement of performance, prices are decreasing year by year, and the application range of DCS control systems will become increasingly broad. DCS has gradually begun to be widely used in small power plants. Copyright reserved by China Control Engineering Network. Small thermal power plants are basically heating units, mainly used for self owned power plants and urban heating by large enterprises in industries such as metallurgy, petrochemical, chemical, textile, etc. Most of them belong to power plants outside the power system.

The typical main equipment selection is mostly a circulating fluidized bed boiler equipped with an extraction steam turbine generator unit, usually consisting of two boilers and one unit or three boilers and two units, with the thermal system being the main pipe. Taking this as an example:
Boiler operation control tasks
① Automatic detection: Use detection components and display instruments to continuously measure and display the thermal parameters (pressure, temperature, flow rate, etc.) of the boiler, and provide detection signals for automatic regulation and safety protection.
② Automatic adjustment: Automatically adjust the operating parameters of the boiler to meet the requirements of external loads and working fluid parameters, and keep the boiler operating under more economical conditions.
③ Program control: Automate a series of operations such as starting, stopping, and running the boiler. If the system is started, follow the starting sequence of the induced draft fan, blower, and grate.
④ Protection interlocking: The system must have functions such as sound and light alarms for overpressure, high water level, and low water level, as well as thermal interlocking protection for overpressure shutdown and low water level shutdown. Electrical interlocking protection is to prevent accidents caused by operational errors during equipment startup and shutdown.
According to the actual usage needs of the boiler, 10 adjustment points have been determined, which are: ① deaeration water level; ② Deaeration pressure; ③ Main steam pressure reduction; ④ Pressure stabilization at the outlet of the cylinder; ⑤ Furnace negative pressure; ⑥ Main steam temperature; ⑦ Drum water level; ⑧ Grate speed; ⑨ Blowing speed; ④ The speed of the coal feeder (controlling the thickness of the coal seam), etc. The drum water level and main steam temperature are the key points of boiler system control, while combustion automation is the difficulty of boiler system control.