First, the chemical tanker 37KW PUMP now operating conditions Austrian oil tanker pump consists of four 37KW vertical pump, the main commitment to four workstations in the 8 loading point to the tanker to carry out the measurement and loading of oil work. Each loading point of the pipe design output flow of 60 cubic meters per hour, 37KW flow of 180 cubic meters per hour oil pump, a pump to undertake a loading station 2 loading point of the oil filling tasks (No. 1 valve and 2 valve, the valve opens to the tanker oiling); and most of the actual production and operation of the time only open a valve out of oil, two loading oil at the same time loading little oil, the original 37KW design of the pump is two However, when a valve is opened, it needs to work at full capacity. When the pump is working at full capacity, the output flow of the oil pump can reach 180 cubic meters per hour, and only one-third of the flow rate can be required when it is actually used Meet the production requirements, through the analysis of the working principle of the entire oil delivery system, the original operating principle of the oil pump has the following problems: The output flow of the 1,37KW oil pump is too large, only need to open the oil pump when the oil pump Of the third flow, each time the oil pump is open full load 180 cubic output operation, so pump and pipe have a great pressure, the formation of eddy pressure, pipeline pressure increases lead to the motor Netherlands increases, the current rise, causing energy waste. 2, the pump due to the large output volume and the actual pipeline delivery capacity is small, this work environment, the pump operation has generated a large number of useless power consumption, but also greatly shortening the service life of the pump motor, increase equipment maintenance costs. Based on the above work background, it is necessary to upgrade the pump motor system for energy-saving operation and use the inverter governor to operate the oil pump to obtain adjustable flow and pressure, and to automatically control the oil pump system according to the actual demand of the flow and pressure . Second, the oil pump system with variable frequency speed control running principle of energy-saving pump in the original working characteristics for the motor to start running at 50Hz, speed of 1420r / min turn, the output flow of 180 cubic meters, the speed and flow pressure is proportional to, as shown : We can see from the figure above, through the pump motor speed changes, the flow rate decreases with the lower speed, so only the use of inverter pump motor speed to become freely adjustable, but also to the pump flow and pressure Adjustable, through the frequency adjustment to achieve the existing production process requirements. We use the Beijing Branch Da Linker Electric Co., Ltd. production Ling Ke LK600P series pump-specific inverter to improve the operating characteristics of the oil pump, and make full use of the inverter speed control function to achieve flow and pressure adjustable to arbitrarily adjust the motor Speed ​​to achieve the purpose, but also play a saving power, the service life of Ting long pump motor, environmental protection and energy saving is the original intention of this project. Energy-saving operation of the pump by frequency conversion basis? --- The working principle of frequency conversion In this do not do a detailed description, we can compare the chart below can be seen, the frequency of motor speed changes, the motor load current also changes. Of course, due to lower motor speed inverter output voltage is also reduced immediately, through the voltage drop, the pump load current is also reduced. The data described below is the actual data measured by our company in the field of motor operation. Fig. 2: The table shows the load current of the motor when the 37KW oil frequency is running. Table 1: The pump motor speed, motor running current and the flow rate change at any rotation speed of the 37KW oil pump during inverter operation. Table 1: 37KW pump at different speeds of variable speed load current and flow rate changes. (A) Frequency of motor running at frequency conversion (Hz. R / min) Pump actual load current (A) Pump output flow rate (cubic) Y225M-4 37KW 74A 50Hz-1420r / min 74A 173 45Hz -1278 r / min 61A 158 40Hz-1136r / min 51A 123 37Hz-1050r / min 49.5A 117 35Hz-994r / min 48A 110 33Hz-937r / min 47.5A 107 30Hz-852r / min 45A 90 25Hz-710r / min 43A 71 20Hz-568r / min 43A 40 Oil pump Motor type Current during operation (A) Motor speed at frequency conversion (Hz.r / min) Pump actual load current (A) Pump output flow rate (cubic) Y225M-4 37KW 74A50Hz- 1420r / min74A173 45Hz-1278r / min61A158 40Hz-1136r / min51A123 37Hz-1050r / min49.5A117 35Hz-994r / min48A110 33Hz-937r / min47.5A107 30Hz-852r / min45A90 25Hz-710r / min43A71 20Hz-568r / min43A40 Field Data: A 37KW oil tanker supplies a workbench with two oil filling valves. One oil filling valve is designed to output a flow of 60 ,,,,, cubic. When the two are simultaneously opened, the flow rate can meet the production requirements of 120 cubic meters and how to realize one Filling valve open, The inverter just outputs a precise flow of 60 cubic meters? Explained in detail in the solution below. When a tanker for oiling work, the drive to 25Hz operation, the motor current is 43A, you can save current 51A, saving rate of 60% or less. Open two oil filling valve for the two tanker oiling, the frequency of 35Hz inverter, motor current 48A, saving current 26A, saving rate of 40% or less. From the list and on-site data to break the coal Qinhuangdao CNOOC depot existing oil pump works, I can see the inverter in the operation of the pump to play a role, by controlling the frequency of the pump motor speed Pump output of a reasonable flow and pressure to meet production requirements, but also greatly reduce the load current of the motor, energy saving is very obvious. Third, the inverter control mode The role of the inverter is to provide variable frequency power supply to the motor to achieve stepless speed regulation, so that pipe network continuous hydraulic changes. The task of the pressure transmitter is to detect the flow and pressure of the pipe network. The flow and pressure setting units provide the system with the desired flow and pressure to meet the needs of the user. The flow and pressure setting signals are input to the inverter through the 4-20mA current feedback signal and then calculated by the inverter's internal PID control program to output a speed control signal to the inverter. The inverter starts to work when receiving the 4-20mA current signal , First start the pump motor, the network flow hydraulic pressure reaches the set value, after the inverter output frequency reaches the peak with the flow and pressure, the inverter speed began to decline until the pipe network to maintain pressure and flow delivery in line with the production Required within the desired value. When the increase in oil supply or open the two outlet valve when the pipeline pressure weakened, the pressure transmitter will handle this signal into the 4-20mA signal into the inverter, (Note: The inverter is based on the current value of 4-20mA To determine the size of the output frequency, the frequency of the motor speed is high and low), the inverter frequency began to rise, the inverter output frequency increases, the pump speed increased, the corresponding increase in flow and pressure, if the injection output flow increased a lot, The frequency converter output frequency will reach the maximum 50Hz, based on the above, through the built-in PID control of frequency conversion can make the whole set of oil supply system more operational, greatly reducing labor intensity. As the whole electric system of the oil tanker adopts the host computer set control, the oil pump motor is started by the soft start mode, the start and stop of the oil pump are centralized control and machine-side control respectively, and the operation console is two Prime solenoid valves. Solenoid valve switch to take the oil tanker to pay the oil work, the official Smith valve with flow measurement and pressure transmitter function, the inverter can provide a 4-20MA transmitter signal output, pressure transmitter value can be set free size , Set the corresponding transmission value 4-20MA output. When Mitsubishi Motors 4-20mA signal input interface to receive the pressure transmitter to send the current signal, according to the size of the signal source and then through the inverter built-in PID control calculation, can automatically and completely make the pump at a predetermined flow pressure Work, to achieve the production line of the production process requirements. Fourth, the system program In the oil depot in the production process, the pump in the entire system belongs to a very important production equipment, requires the inverter can be a long time continuous operation, should have the performance should have a very high reliability, in understanding the site The characteristics of the production process combined with this design, the system design should have to adapt to the scene operating performance, and fully compatible with the original electrical system, so that the original control characteristics unchanged; the system design has the following features: 1, frequency conversion system and the original power frequency soft starter system can manually switch freely. Once the frequency conversion system has some kind of fault, you can manually switch to the prime mover frequency power soft start, when the inverter system maintenance, the original soft starter system can guarantee the normal operation of oil pump to meet the normal production of oil depot. 2, The operating frequency of the frequency conversion system adopts PID closed-loop control loop, according to the flow pressure to send 4-20mA letter to determine the inverter output frequency, so as to ensure the safe operation of the oil system and make the whole system more convenient. , Intelligent automation stronger.
Yantai Ciso Lubrication Technology Co.,LTD , https://www.cisolubrication.com