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Application of Siemens automation products in the heat dispatching system from Daqing Longfeng thermal power plant to Chengfengzhuang area

the heat dispatching system from Daqing Longfeng thermal power plant to Chengfengzhuang area is a typical application of Siemens automation products. Each thermal power station adopts MPI communication mode of tp27 and CPU314, the dispatching center is two industrial control computers that are standby to each other, and cpu315 communicates by MPI. The data of the heating station is uploaded through CP340 and modem, and cpu315 of the dispatching center receives the data transmitted by modem through CP340. The data is transmitted in two directions, which realizes the real-time monitoring of important operating parameters such as temperature, pressure and flow of each thermal power station by the dispatching center, the timely feedback of various alarm information and the rapid issuance of various dispatching instructions, and overcomes the shortcomings of traditional information exchange, the influence of external factors and incomplete information recording

the upper software of the central dispatching station adopts WinCC, and the functions are detailed in the user manual

the system has been used for nearly half a year, and users have responded well

our company has specially developed a set of sewage treatment control system for the oilfield sewage treatment station. The controller in the system is composed of Siemens PLC and Op37, the communication mode is MPI, and the manager is an industrial computer installed with WinCC software. The local controller is installed on site to control and monitor the operation of field equipment, and the central controller is responsible for backwashing the tank controlled by each local controller. The communication between local controller and central controller adopts PROFIBUS FDL mode, and the communication between manager and controller is PROFIBUS communication (5412 card). This system has been put into operation in many sewage treatment stations of Daqing Petroleum Administration Bureau, and users have responded well

1 system structure

this system is composed of three parts: local controller (wsk-100-01), central controller (wsk-100-02 or wsk-100-03) and upper computer manager (wsk-100-10). Each part can be installed, operated and operated independently, and can also be managed and operated in a centralized manner. In this way, control is decentralized, management is centralized, and the reliability and real-time performance of the whole system are improved

1.1 wsk-100 sewage control system is composed of several wsk-100-01 local controllers, a wsk-100-02 (03) central controller and a wsk-100-10 manager according to the process requirements. Among controllers, controllers and managers are connected and organically combined through PROFIBUS communication protocol, and the composition is as shown in Figure 1:

Figure 1 control system structure diagram

plastic tensile testing machine data collection is faster, and the newer software can more obtain the peak load

1.2 wsk-100-01, wsk-100-02, wsk-100-03 and other controllers are composed of Siemens S7-300 modular programmable controller and Op37 operator panel, Op37 is connected to S7-300 through Siemens standard netmpi, and its hazardous area instruments are connected to the system through MTL isolation safety barrier. The structure of the controller is shown in Figure 2

Figure 2 controller structure diagram

1.3 wsk-100-10 manager is composed of industrial PC (CPU Intel Pentium MMX166, 32m memory, 2.1g hard disk, two RS-232 serial ports, one LPT parallel port), keyboard, mouse, 20 inch display, printer, communication card, modem (optional), Honeywell console. The manager structure is shown in Figure 3

Figure 3 manager structure

2 technical conditions

2.1 signal type

· analog input signal: 4-20mA four wire system, two-wire system

· switching input signal: dc24v

· analog output signal: 4-20ma

· switching output signal: relay node

· pulse signal: (24v200khz, 5v500khz)

note: see Appendix (III) terminal for specific accessible signals.Wiring diagram

2.2 communication protocol

· Siemens MPI (187.5kbps) multipoint communication protocol

the software design of static load tensile testing machine adopts the modular design method. Green Mobil company is in the leading position in China in the industrial field, and the bus PROFIBUS communication protocol

2.3 protection grade IP44

2.4 operating environment

· temperature: 0 ~ 60 ℃

· humidity: 5 ~ 95%, no condensation

· vibration: 10 ~ 58hz, constant amplitude 0.075mm

58 ~ static testing machine mainly includes: 1. Universal testing machine: hydraulic universal testing machine and electronic universal testing machine; 2. Pressure testing machine; 3. Tension testing machine; 3. Change testing machine; 4. Creep testing machine; 150Hz constant acceleration 1g

3 system function

3.1 wsk-100-01 local controller can complete the normal filtration control and backwash control functions of two filter irrigation. The process requirements are as follows:

· the distribution of upper and lower inlet water flow is 1.5:1. Through the adjustment of digital PID (see Appendix II for the algorithm), it is stable within 60 seconds after disturbance, and the static error is less than 1%

· entry of automatic backwashing process: through the operator panel on this controller or wsk-100-02 (wsk-100-03) controller or wsk-100-10 manager. When the backwashing is finished, it will automatically return to the normal working state

· manual and automatic undisturbed switching

· the valve can be operated manually to alarm the failure of the controlled valve

3.2 wsk-100-02 standard central controller can complete the monitoring and management functions of backwashing, liquid level of recovery pool, liquid level of sewage buffer tank, etc., as follows:

· set the total inflow flow of filtered water, evenly distribute it to 1 #, 2 #... And other filter tanks, and re allocate the flow during backwashing to ensure that the total flow remains unchanged

· automatic control backwashing, including single tank backwashing, all primary filter tanks or all secondary filter tanks backwashing, all backwashing, timed backwashing, etc

· backwashing methods are divided into PID flow control and valve position control backwashing

· automatic control of liquid level in recovery pool

· automatic liquid level control of sewage buffer tank

· automatic liquid level control of backwash tank

· manual and automatic undisturbed switching

· manually control all valves and pumps

· the liquid level exceeds the limit, and the valve and pump fault alarm

3.3 wsk-100-03 enhanced central controller not only has the function of wsk-100-02 central controller, but also increases the liquid level of backwash buffer tank

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