Design of Unattended Pumping Station System in Open-pit Mine

1 IntroductionThe mining field of Suichengmenshan Copper Mine is responsible for the drainage of the open pit, the production of the whole mine, and the water supply for daily life. At present, there are 3 drainage pumping stations in mining farms, 1 intermediate pumping station, 2 draining pumping stations, and 2 water supply pumping stations. Each pumping station uses traditional manual manual control to realize water supply and drainage. This method has disadvantages such as high labor cost, low safety factor, and low efficiency. In order to change the traditional way of water supply and drainage, according to the overall requirements of Chengmenshan Copper Mine’s intelligent construction, combined with the actual needs of the pumping stations of Chengmenshan Copper Mine, an unattended pumping station system for open-pit mines has been designed [3]. Fully realize the automatic control of the pump station, improve the utilization and efficiency of the water pump, improve the safety production coefficient, and reduce the production cost.2 Overall system architectureThe open-pit mine unattended pumping station system integrates various data monitoring, operating status monitoring, fault alarm, fault self-diagnosis and self-recovery, automatic control, remote data transmission and other functions of the pump. The system structure is designed into three parts: pump station monitoring system, communication system, and remote monitoring system. The system structure diagram is shown in Figure 1.2.1 Pumping station monitoring systemThe pumping station monitoring system [5] is the bottom layer of the unattended pumping station system of the open-pit mine, mainly for the water level of the pumping station sump, water pumps, motors, drain gate valves, submersible pumps, water injection valves and exhaust valves, and power distribution equipment And start the cabinet, etc. to monitor, and through the programmable logic controller (PLC) acquisition and control, to achieve automatic control of the pump [1] and other functions.The main monitoring parameters are:(1) Electricity monitoring: main motor operating current, voltage, power, etc.;(2) Flow monitoring: single pump flow or single pipe flow;(3) Liquid level monitoring: the water level of the pumping station pool;(4) Pressure monitoring: pump outlet pressure and pipeline pressure;(5) Temperature monitoring: water pump bearing temperature;(6) Vibration monitoring: water pump bearing vibration;(7) pH value monitoring: the pH value of drainage;(8) Turbidity monitoring: drainage turbidity;(9) Equipment status: the working status of the main water pump, main motor, drain gate valve, submersible pump water injection and exhaust valve, power distribution equipment and starter cabinet;(10) Protection information: various protection events and protection settings of the equipment, etc.The automatic control of the pumping station uses a PLC controller, through the input and output of various digital and analog quantities, and carries out logic programming to realize automatic control of the various actuators on site. Its main controlling executive agencies are:(1) Small submersible pump control: control the start and stop of the small submersible pump to realize the irrigation and diversion of the water pump;(2) Gate valve control: control the opening and closing of each gate valve in the pipeline to realize the control of water flow;(3) Motor control: control the start and stop of the water supply and drainage motors to realize the automatic operation of the water pump.2.2 Communication systemThe unattended pump station communication is mainly divided into two parts: on-site monitoring, communication between control signals and PLC; PLC and dispatchingCommunication between the heart host computers.The Chengmenshan Copper Mine Pumping Station realizes the start of the water pump through a soft starter and a frequency converter, and has a 485 communication [6] interface. The collection of current and voltage can be realized through the 485 communication module. On-site liquid level, temperature, etc. monitoring, motor, gate valve, etc. control and signal acquisition control cabinets are collected and controlled through PLC input and output simulation. The signal acquisition control cabinet and PLC control cabinet realize communication through optical fiber transmission.Each pump station of Chengmenshan Copper Mine has realized the laying of optical fiber. The communication between the on-site PLC control cabinet and the host computer of the dispatch center is realized through optical fiber transmission. The unattended pumping station also includes on-site video monitoring, and the signal transmission of the monitoring is also realized through optical fiber transmission.In order to ensure that the dispatch center can still collect on-site operation data when the optical fiber communication is interrupted. Combined with the Chengmenshan Copper Mine 4G wireless network system construction project, the wireless communication between the PLC control cabinet and the upper computer of the dispatch center is realized. This communication method is used as a backup method to ensure uninterrupted monitoring of each pumping station. The main implementation method is: install EG860 CPE (broadband wireless router) at each pump station site, connect with the base station in the mining area to complete the system network, the PLC system can be connected to the LTE wireless network through the network port wired mode or WiFi wireless mode. Finally, the wireless communication between PLC and host computer can be realized.2.3 Remote monitoring systemThe remote monitoring system is set up in the mining farm dispatch center [4], and it is equipped with two industrial computers and servers, communicates through optical fiber communication and 4G wireless network, and is based on the configuration software Intouch software platform to collect relevant data in the PLC controller in real time , Issue control commands and monitor the overall operation of the system. The configuration software can make full use of its powerful graphic editing function, visually display the running status of the monitoring equipment in the form of animation, and conveniently constitute the monitoring screen and realize the control functions.3 Design of automatic control system for pumping stationAccording to the current status of Chengmenshan Copper Mine’s mining field, 10# pit pumping station, +20 fixed pumping station, +30 fixed pumping station, draining pumping station and W pumping station are determined as unattended pumping stations. Because the hardware facilities and control logic of each pumping station are basically the same, this time we take 10# pit drainage pumping station as an example to design the automatic control system.3.1 Current status of drainage pumping stationsPit No. 10 drainage pumping station [2] consists of 2 single-stage centrifugal pumps, 2 drainage pipelines and corresponding auxiliary systems. Related facilities such as water pumps are installed on the floating raft and placed in the sump. The suction pipe of the water pump is equipped with a DN300 foot valve, and the outlet pipe is equipped with a DN150, PN16 gate valve. The flange of the pump set is DN150, PN25 size. The pipeline of No. 10 pit is laid with DN400 steel wire skeleton composite pipe, and drains to the +20 pump station. The whole distance is about 800m. The distance from the on-site low-voltage power distribution room to the water pump is about 300m, and the water pump is controlled by a frequency converter.3.2 Hardware transformation of the automatic control system of the drainage pumping stationIn order to realize the automatic control of the pumping station, the existing equipment does not meet the demand, and the hardware needs to be modified. details as follows :Install a submersible pump on the side of the floating raft for water pumping and diversion; the front end of the pump is equipped with a water replenishment ball valve and an exhaust gate valve, and a flow switch is installed on the exhaust gate valve for irrigation and diversion to remove the air from the pump and to detect whether the air is empty; the pump is discharged Replace the water outlet with an electric gate valve; install a pressure sensor and a flow meter near the outlet pipe of the water pump and the outlet pipe of the drain pipe to monitor the pressure and flow rate of the drain pipe, and judge whether the pipe is leaking through the data difference; in the sump Install a level gauge, a turbidity meter and a pH meter to monitor the water level, water quality, and the pH of the silo, and determine whether it can drain; install a temperature sensor and a vibration sensor on the motor to determine whether the motor is running normally ; Install the 485 communication module on the control cabinet to collect the inverter voltage and current.In addition, in order to facilitate the collection of on-site control and monitoring signals such as water pumps, an information collection cabinet is installed around the water pump, and the PLC control cabinet is placed in the low-voltage power distribution room. Optical fiber communication is adopted between the information acquisition cabinet and the PLC control cabinet.3.3 PLC logic control design(1) The logic control process of the normal start and stop of the water pump: the water level of the sump reaches the upper limit of the setting → open the water replenishing ball valve and the exhaust ball valve to start divingPump → monitor the flow switch, there is water outflow, close the water replenishing ball valve, stopStop the submersible pump and the exhaust ball valve to turn on the water pump and open the water outlet electricGate valve → the water level of the sump reaches the specified lower limit to close the electric gate of the water outletValve and stop the operation of the water pump;(2) Logic control of pipeline leakage: pipeline pressure difference before and after detectionAbnormal or abnormal pipeline flow difference before and after detection to judge pipeline leakageStop the water pump or prohibit the start of the water pump;(3) Abnormal monitoring parameters logic control: abnormal monitoring data such as motor operating temperature, vibration, current, voltage, flow, pressure, water quality, etc., immediately close the gate valve and stop the pump motor or prohibit the motor from starting, and perform alarm self-diagnosis at the same time to determine the fault Maintenance mode.4 Realized functions(1) Automatic control function of pumping station: realize the automatic control of each pumping station through the logical control of the actuator of each pumping station;(2) Pipeline leakage detection function: real-time monitoring of pipeline pressure difference and flow difference, automatic alarm when lower than the system set value, realize pipeline leakage monitoring;(3) Energy-saving function: balance the running time of the two pumps to ensure balanced use of the pumps and extend the service life of the pump set; ensure energy-saving measures for peak shifting and valley filling, and the system automatically selects electricity when ensuring safe water supply and drainage Water supply and drainage in Pinggu period;(4) Safety function: It has two modes of remote control and local control to meet the needs of on-site operation. When the signal is interrupted, the system will send an alarm and automatically switch to automatic control; all aspects of water supply and drainage are monitored in an all-round way. Early warning is given in advance when the system is abnormal; normal water supply and drainage shall be carried out in strict accordance with the logical sequence of pump start and stop.

Post time: 21-09-21