Energy-saving applications of Mitsubishi Motors inverters in the oil storage pump

In the oil depot operating the production process, the oil pump in the entire production system is the daily average frequency of use of the most equipment, and most of the oil tank pump start-up method are used star delta start, due to the star delta start mode on the motor and pump impact Resulting in a number of weaknesses such as accelerated acceleration of the oil pump bearing and increased noise. The following is the on-site data obtained by the Company when it transforms the oil and gas storage and transportation center of the Qinhuangdao Coal Transportation and Storage Center in the coal industry.

First, the current situation of the operation of the 37KW oil pump of the Austrian oil depot

The Austrian oil tanker pump consists of 4 sets of 37KW vertical oil pump, which mainly undertakes 8 loading points in 4 workstations to carry out the measurement and loading work on the tanker truck. 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 open to the tanker oiling); and most of the actual production and operation of the time only open a valve out of oil, while loading the two cars at the same time loading very little oil pump 37KW originally designed for 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 existing oil pump operating principle has the following problems:

1,37KW pump output flow is too large, in the opening of a valve when only one-third of the flow of oil pump, pump every time the full opening of 180 cubic output load operation, so pump and pipe have a lot of pressure Poor, the formation of eddy pressure, pipeline pressure increases lead to increased motor load, the current rise, resulting in waste of electricity.

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 converter governor to operate the oil pump to obtain adjustable flow and pressure, and automatically control the oil pump system according to the actual demand of the flow and pressure .

Second, the oil pump system uses frequency conversion speed regulation of energy-saving technology

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 frequency inverter pump motor speed to become freely adjustable, but also to the pump flow and pressure can Adjust, 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 (Cube)


74A 50Hz-1420r / min 74A 173
45Hz-1278r / 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

On-site data: A 37KW oil pump to supply a working table two oil filling valve work, a fuel injection valve design output flow of 60 cubic meters, two at the same time open, the flow rate of 120 cubic meters to meet production requirements, how to achieve a filling valve Open, the inverter just output 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, through the variable frequency control of the pump motor speed, so that 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

The role of the inverter is to provide variable frequency motor power to achieve stepless speed regulation of the motor, 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, Inverter output frequency will reach the maximum 50Hz, based on the above, through the built-in PID control of frequency conversion can make the entire 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 operation of the oil depot in the production process, the oil 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 of the production process characteristics 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.

3. Considering the working environment and equipment safety in the scene, it is not advisable to set too many display devices on the panel of the inverter control cabinet, and only configure the soft starter and the inverter conversion switch, the operation indicator light, the inverter running fault light, the inverter operation display panel Inverter operating parameters, motor current, motor speed at a glance, which greatly facilitates the operation of site operators and equipment operation monitoring.

4, Set the 6-digit password in the inverter system to lock and protect the running parameters of the inverter to ensure that the variable-frequency oil delivery system will not stop the oil pump under the wrong operation and realize continuous and smooth operation of the system.

5, inverter wiring with independent wiring to eliminate electromagnetic interference with the equipment to ensure the safe operation of equipment.

6, The frequency conversion system implements the soft start and soft stop of the oil pump motor, reduces the impact on the power grid in the starting process, improves the power supply quality as well as prolongs the maintenance period of the oil pump motor. Since the motor speed drops after using the frequency conversion , Low-speed operation of the pump shaft, bearing wear and tear to reduce, which will greatly extend the oil pump bearings, mechanical seals and other wearing parts of life.

Fifth, project cost

This project is made up of 4 37KW oil pumps, the frequency changer selects 4 37KW LK600P series pumps specialized frequency changers, the entire project cost as follows:
Serial number Product Model Quantity Unit price RMB Total RMB RMB Total project cost
1 Lingke LK600P-037T4
37KW frequency changer

2 cabinets GPT 4 4300.00 17200.00
3 air switch, contactor, display panel,
Transfer switch, indicator light, intelligent feedback card 4 5300.00 21200.00
4 Control Cable and Main Motor Cable 1 12000.00 12000.00
5 site wiring construction fee 1 8300.00 8300.00

Investment cost recovery period 4 oil pumps work 12 hours a day, according to the measured average saving rate of 40% (this data is the real value of other projects, does not represent the accurate data of this project) 4 months can be recycled All investment.

Seven, concluding remark
In the entire oil depot production and operation in the past, the pump is the main production system of the entire production process, but also the entire operating system of large electricity consumers on the pump energy saving has a certain degree of necessity, the current pump energy saving Effective technical approach is to use frequency converter, frequency control function to improve pump performance. In the implementation of the entire system during operation, the inverter not only for the entire system of a smart addition extremely, but also make the entire production process more humane, intelligent automation, but also have enormous economic benefits, such as the life of the pump Ting long, Reduce maintenance costs, etc., I believe the beneficiaries of this project more than the project implementation experience.

This equipment is divided into vertical and horizontal structure, used for semi-finishing process of steel ball,

 Main structural features

1)  The rotation of main shaft and turntable adopt frequency conversion speed regulation;

2)   Hydraulic drive pressure, mechanical pressure preservation by compression spring and constant pressure nut locking;

3)   Adopt end face bearing with high capacity;

4)   The main shaft bearing adopts the mechanical seal structure, which eliminates the hidden danger of the main shaft oil leakage;

5)  The main transmission uses reduction box with a pair of increase modulus and widening gears. The power is transmitted to the  spindle through the output shaft of the bevel gear. The transmission structure is simple and reliable;With mechanical grinding  wheel dresser driven by belt motor;

6)  Adopt small cycle processing in accordance with the requirements (without turntable).

1)Horizontal layout, large cycle machining;

2)L type low gravity structure is adopted, and the moving plate is moving pressurization;

3)Side mounted flat turntable;

4)The opening size of the ball plate, the positioning size of the ball plate, types of turntable (plate or incline), the amount of ball loading, the spindle speed and the power of the main motor can be customized according to the requirements of the customers.

Ball Grinding Machine

Ball Grinding Machine,Steel Ball Grinding Machine,Steel Ball Grinding,Vertical Steel Ball Grinding

Xinxiang Sunrise CNC Bearing Equipment Co., Ltd. ,