superiority target type flowmeter
Published on:2015-4-3 13:41:04 Hits:

Anqing Petrochemical fuel thermal power generation currently required - a major supplier of coal by rail and waterways two lines. Railway part of its coal handling system has been adopted PLC control system with automatic and manual operation. The waterway is still part of the conventional relay logic control, can only be operated via the console button. This obsolete equipment, the number of multi-relay action frequent contacts easily damaged failure rate, and can only be used on-site manual control, the need to telephone contact between the control room and the field, the entire system segment stops, low degree of automation, not conducive to deal with the accident, seriously affecting the normal operation of the production.

Coal handling system for secure, stable operation, part of the waterway transport control system of the plant was modified to IPC for the man-machine interface, PLC program control system, the abolition of the original console button operation, the relay interlocking and Simple analog control panel display, the entire procedure drawn into a dynamic flow chart picture, monitored by IPC and


2 System Architecture

2.1 Control Range

Control range of the riverside quay coal transported by belt conveyor to the coal yard or the entire work process equipment bunker layer self. Transformation of the control system including coal stevedoring monitoring interlock system (see Figure 1) and a coal handling plant interlock system (see illustration) in two parts, the interlocking relationship is actually the reverse flow direction of the coal produced, that only the latter Start and enter the normal operating state, the former to start. Plant coal handling system for double-belt conveyor belt, formed a A, B are two independent operating mode and two-way cross of two independent single-system operation mode.


Figure l coal terminal handling interlock system monitoring


2 coal plant interlock system diagram

2.2 Control Objects

Control objects entire interlocking system includes control, detection and alarm 23 belt machine and its auxiliary equipment. Wherein the control parameters of the main belt and completed 23 of 14 starts and stops dust; detection parameters include clauses belt light deviation, heavy deviation, open stop state, pull switch, speed switch, switch, etc. display and show the value of the motor current state, including the position of the fork tube, coal drop tube baffle, in addition to the large wood · plow coal, bucket, Separators, belt scales, nuclear scale and Coal Hoppers and other auxiliary equipment displays the status and parameters, enter the entire interlocking system, output points listed in Table l.

Table 1 interlock system input and output points

2.3 Interlock Control System Architecture

Coal handling system of the entire waterway span, equipment scattered, harsh environment of the scene, using a centralized management of distributed control systems can not only reduce the amount of cable length and construction engineering of the entire system, but also greatly improves the reliability of the system and level of automation. Given the input of the system, the output of main switch, the entire control are sequential logic control, so choose the AB SLC500 system's small programmable logic controller, the products of a master controller scalable multiple remote control stations, more suitable for control objects scattered span of the occasion, however, extend to a remote station also need to increase the overhead, determine the number and location of the remote station must consider its cost performance, integrated various factors, the system uses a transformation a main control station with a remote control station system structure 3 (see Figure 3).


3 System Block Diagram

According to the actual operation and distribution of water handling system field devices, the main control system set up in the new control room, 8 #, 9 # 'station and plow coal-site operating room were set l remote control station, input field devices The output signal in accordance with the principle of proximity into each remote station. Among them, the coal terminal handling electrical system through this transformation, the interlock signal can be sent directly to the interior of the new low-voltage switchgear and distribution within the control room instrumentation cabinets P-l; interlock signal is taken from the plant coal handling system each on-site operation of switchgear room, 8 # station, the plant control room on-site operation of electrical switchgear (7 # P and B, 12 # P and B Belt) interlock signals are sent to the operating room scene 8 # station instrument cabinet P- 2,9, # 10 stations operating room scene electrical switchgear (13 # P and B, 14 # P and B Belt) interlock signals are sent to the operating room scene 9 # station p a 3 meter cupboard, plow coal field operation electrical switchgear room (15 # P and B, 17 # P and B Belt) interlock signals are sent to the operating room scene plow coal instrument cabinet P-4. Each remote control station via remote I / O module by l roots communication cables, signal transmission can be achieved with the control room of the master controller (see Figure 4).


Figure 4 Distribution of the interlock system and remote control station master

2 · 4 PLC control system configuration

(Including cabinets, etc.) PLC control system consisting of two parts by the host computer (including computer console, etc.) and the PLC.

2 · 4 · 1 PC section

The system is set up in an industrial computer control room, at the same time with a keyboard, mouse, etc., through the installation of device drivers RSLINX communication with the PLC. IPC has a strong anti-jamming capability and data processing, based on the Chinese version of the RS View32 installation configuration package and run the package under Windows Windows platform, enables the exchange of information through the configuration of programmable devices.

2 · 4 · 2 PLC section

PLC is the core of the entire control system, is responsible for input and output, logic operation and communication. PLC mainly includes the following modules: CPU template, power modules, communication templates, EEPROM memory template, remote I / O scanner templates, remote I / O adapter template, digital input template, template switching output, analog input modules, racks, special cables.

2 · 4 · 3 System Software

System software includes PLC control software and PC configuration software in two parts.

AB PLC control software for companies to provide a RLD300ENE 9324 programming software, the whole system is mainly composed of curing in the PLC control software to achieve, the software programming language using ladder, the main input and output corresponding to the amount in the PLC address allocation, operational control state switch between normal processing and communications functions, failures and emergencies as well as the logical relationships between PC.

PC configuration software for the Chinese version of the RS View32 Developer Edition software, providing end-users through the configuration can be directly displayed and man-machine interface, the software is mainly composed of the system configuration, monitoring screen design, alarm processing, database design and safety settings, and several functional components. After waterway coal control interlock system configuration screen appearance overall system including pictures, main screen, auxiliary equipment monitor screen, belt conveyor movement picture, status information browsing screen, alarm display, trend display screen and so on.

3 system functions

3.1 Control Function

Operator to the CRT mode of transportation and control mode can be selected to achieve the entire coal handling system for device control, and animate the entire interlocking processes to the arrow indication of the interlock operation sequence. Control system is divided into centralized automatic, manual chain, unlock manual and manual operation, four ways, through a variety of start-stop mode select line handling system.

Centralized automatic way to achieve automatic control of coal handling system and fully complete the cycle operation control under normal circumstances by the PLC system, fault alarm and protection control abnormal situations, in emergency situations, such as system control and fault alarm.

Manually operated chain of semi-automatic control, by the operator by using the mouse or keyboard to one start and stop buttons on the HMI device via PC communication between the PLC and the command given PLC, in order to achieve a manual stop any equipment, semi-automatic control purposes that reverse the flow direction of the coal all equipment downtime.

Unlock manual operation means in the case of coal by the operator to manually start and stop any one device on the host computer, this time without any interlocking relationships.

Manual operation running through the field switch control status of the device, the device can not afford at this time Cockpit control action.

3.2 Display Function

Overview screen: show the status of each belt conveyor and auxiliary equipment.

Master Screen: dynamic display status of the entire process and each strip belt interlock and arrow indication of the interlock operation sequence.

Auxiliary equipment monitor screen: Displays the status of auxiliary equipment.

Conveyor Operation screen: Shows all running belts, dynamic display coal process and display the current trends.

Status information browsing screen: list shows the working status of the belt conveyor, working state control status, real-time current position fork tubes and dust collector, separator, in addition to the large wood, coal crusher and other equipment.

Alarm display: Displays the current belt of the more limited, speed switch, blocking coal signal, pull switch, heavy deviation, deviation and other light condition and automatically make the appropriate alarm processing, be recorded at the same time save.

Trend display: Display belt scale and real-time trends and historical trends nuclear scale.

3.3 system security features

Set the emergency stop button in the control room operating table to achieve stopped all equipment transportation system in emergency situations.

Flexible definition of user's operating authority by setting different levels of password security operator to achieve security and reliability of the system.

Set in the PC screen master reset button action when safety devices, associated with that part of the equipment will be blocked only after reset before restarting the system.

Set in the main screen, check the PC with pre-boot button to check the main equipment and auxiliary equipment is in place, not in place in case the system does not automatically interlock.

Dynamic display the current value of the trend of each belt through the PC, and to achieve the current limit alarm, thereby enhancing the security of the entire system.

4 Summary

① The PLC program control system enables the automation level of the whole coal handling system has been greatly improved, to achieve automatic, safe and stable operation of coal handling system.

② through the application of PLC systems, improve the reliability of the control system to solve the relay control system malfunction due to the impact of production problems. Through the application of software fault display, the operator can feel free to correct errors in operation and rapid diagnostic equipment failure.

③ by setting three remote I / O station, by a communication signal transmission cable directly to the control room, save a lot of control cables, but also greatly reduce the construction and installation costs.

④ Due to the flexibility of the PLC system can be easily changed at any time by changing the application process parameters, increase control function, it eventually will replace the traditional relay control.

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