The working principle of the hydraulic booster pump is that the asynchronous motor drives the plunger pump to generate oil pressure, and the hydraulic system converts the oil pressure into water pressure. The normal hydraulic pressure and water pressure pressure ratio is 1:20. Take the mainstream hydraulic booster pump (60000Psi) and the Volmet servo Direct Drive Pump
(60000Psi) as an example.
1, the choice of motor
The hydraulic booster pump uses a 37KW asynchronous motor. The power conversion ratio of the asynchronous motor is about 80%~85%. The Volmet servo direct drive pump uses a 15KW permanent magnet motor. The power conversion ratio of the permanent magnet motor is 97%. Therefore, the power saving of only one motor is: 60% or more
2, the way of pressure conversion
(1) The hydraulic booster pump is an asynchronous motor that drives the plunger pump to generate oil pressure. The hydraulic system converts the oil pressure into water pressure, and the direct drive pump is a process in which the motor drives the crankshaft connecting rod to directly generate water pressure. It will cause energy loss, about 35%, so the direct drive pump is about 35% more energy efficient than the hydraulic booster pump.
(2) The hydraulic booster pump pressurizes the oil through the reversing valve and then converts it into water pressure. The reversing valve will reduce the pressure at the moment of commutation, causing fluctuations in water pressure. For example, to set a pressure of 50,000 Psi, the minimum pressure after the fluctuation can reach 43,000 Psi, and the average pressure is about 45,000 Psi. The Volmet servo direct drive pump can maintain a constant pressure, setting 50000Psi, the output water pressure is 50000Psi, so the cutting efficiency will be greatly improved, (50000-45000) / 45000 = 11%, cutting efficiency will increase by 10% -20%.
3, control mode
(1), hydraulic booster pump is generally started by direct start or star triangle, although it can reduce some starting current, but the impact on the power grid and power consumption is still very large. The Volmet server direct-drive pump uses a fully intelligent soft start, starting current to several amps, completely avoiding the impact on the grid and reducing power consumption.
(2) After the hydraulic booster pump is started, whether the high-pressure water has output or no output, the motor will run at a constant speed, and the power is always consumed. The Volmet servo direct drive pump uses a fully intelligent frequency converter to control the operation of the servo motor. The motor will start to work only when there is output from high pressure water. When the high pressure water has no output, the motor will stop running. This will reduce the consumption of electricity and play a role in energy conservation.
4. Example: Take the processing of tile mosaic as an example (set the working pressure to 50000Psi): work 12 hours a day, the actual cutting time (high pressure water output time) is about 5 hours, 37KW asynchronous motor is rated on the hydraulic booster pump The average power consumption is 20 degrees / hour, 20X12 = 240 degrees / day, calculated according to 300 days of work, 240X300 = 68000 degrees, Womart servo direct drive average of 5 degrees / hour, 5x12 = 60 degrees / day, 60x300 =18000 degrees. Therefore, the Volmet direct drive pump can save customers about 50,000 degrees per year.
For users, the longer they work each day, the more power they save.
Comparison of the Volmet servo direct drive pump and the FLOW direct drive pump:
Although the FLOW type direct drive pump also uses the crankshaft linkage mechanism to eliminate the loss of the hydraulic energy of the original booster pump, the Volmet servo direct drive pump has a significant advantage over the FLOW direct drive pump.
1, the choice of motor.
The FLOW direct drive pump uses a 22KW asynchronous motor. The power conversion ratio of the asynchronous motor is 80%. The Volmet servo drive pump uses a 15KW permanent magnet motor. The power conversion ratio of the permanent magnet motor is 97%. Therefore, the energy saving of only one motor is: 30% or more
2. Motor starting mode.
The FLOW direct-drive pump adopts the star-delta step-down start. Although it can reduce some starting currents, it still has a large impact on the grid and power consumption. The Volmet server direct drive pump uses a fully intelligent soft start, and the starting current is reduced to several amps, completely avoiding the impact on the grid and reducing power consumption.
3, pressure control mode
The pressure control of the FLOW direct drive pump uses the form of overflowing excess high pressure water to control the pressure and work at a constant speed. If no overflow is used, its pressure will reach 60,000 Psi, the vast majority in reality. In order to make the equipment work stably (and also to save the cost of wearing parts), the pressure is mostly used at around 46,000 Psi, so there will be (60000-46000)/60000=23.3% energy loss.
This high temperature overflow phenomenon has many drawbacks:
1. The poppet valve is a relief valve with pneumatic pressure control. The structure is complex and it is prone to jam or unable to control the set pressure to close. In the event of a jam, the system pressure of the direct drive pump will rise sharply, reaching the pressure to destroy the normal working high pressure fittings, and the loss is huge. If you can't turn it off, you can't put pressure on the system.
2. The use of the poppet valve system is demanding on the water quality of high-pressure water. If the water quality is not up to standard, the high-temperature water will cause serious scaling and cause a series of failures.
The pressure control of the Volmet servo direct drive pump uses full closed loop servo intelligent pressure control. How much pressure is required to cut the cutter head, and how much power the servo motor outputs. This not only saves energy but also avoids the drawbacks of the poppet valve.
4, the service life of high-voltage components
It is well known that a high-pressure component is a component that is resistant to fatigue, that is to say, in the case of the same quality, the service life of the high-voltage component depends on the number of super-high pressure exchanges inside the component.
For example, in the case of the same nozzle and the same pressure, the FLOW type direct drive pump has an alternating number of times per minute of 1500/2=750, and the Volmet servo direct drive pump has an alternating number of times of 580 times (750-580). /750=22.7%
Therefore, the life of the high-voltage components and related components of the Volmet servo drive can be increased by 22.7%.