CN214424700U - Oil injection double-screw vacuum pump control system - Google Patents
Oil injection double-screw vacuum pump control system Download PDFInfo
- Publication number
- CN214424700U CN214424700U CN202022466278.1U CN202022466278U CN214424700U CN 214424700 U CN214424700 U CN 214424700U CN 202022466278 U CN202022466278 U CN 202022466278U CN 214424700 U CN214424700 U CN 214424700U
- Authority
- CN
- China
- Prior art keywords
- vacuum pump
- vacuum
- air pressure
- variable frequency
- control unit
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
Images
Landscapes
- Control Of Positive-Displacement Pumps (AREA)
- Applications Or Details Of Rotary Compressors (AREA)
Abstract
The utility model discloses an oil injection double-screw vacuum pump control system, which comprises a vacuum pump body; the air inlet filter is arranged at an air inlet of the vacuum pump body; a first vacuum pressure sensor disposed at a front end of the intake filter; the permanent magnet variable frequency motor drives the vacuum pump body; the control unit is used for receiving a first air pressure signal detected by the first vacuum pressure sensor, wherein the control unit limits the permanent magnet variable frequency motor to operate at a constant power when the first air pressure signal is in a rough vacuum air pressure range. Through the application of the utility model, the vacuum production and manufacturing cost of the screw can be effectively controlled; meanwhile, the vibration of the pump body can be reduced, and the service life of the vacuum pump body is prolonged; the production requirements of customers in different production periods can be met, the power consumption of the vacuum pump is effectively controlled, and the energy is saved.
Description
Technical Field
The utility model relates to an oil spout double-screw vacuum pump control system.
Background
Oil-injected screw vacuum pumps are generally used to draw low vacuum conditions. It is widely applied to the industries of electronic chemical industry, pharmaceutical medical treatment, vacuum packaging, processing adsorption and the like.
The control system of the oil injection screw vacuum pump newly released by each family in the current market is used for controlling the vacuum pump body to pump air by voltage reduction self-coupling starting, and the following problems can not be avoided.
The rotating speed of the vacuum pump is constant, the control is complex, and the operation under multiple working conditions of customers cannot be met. During the rough vacuum period of 700mbar to 1013mbar, a large amount of gas is instantaneously sucked, and oil film is not completely formed in oil injection in the system, so that the rough vacuum extraction time is short, the early-stage over compression is caused, and the energy consumption is increased. And during the stable vacuum period of 700mbar to 20mbar, the power consumption fluctuation is small because the gas suction is stable. In contrast, rough vacuum consumes more power than during steady vacuum. The problem can be solved only by increasing the service coefficient of the motor or the model of the motor during design, so that energy is wasted, cost is consumed, and a client can only operate at a constant rotating speed. The large load can also cause the rotor inside the pump body to vibrate, and noisy noise is formed. And in the initial stage, because a large amount of gas is instantly sucked into the vacuum pump body, oil injection is reduced, a stable oil film cannot be formed, so that a large amount of oil molecules are contained in the gas, the oil-gas separation processing capacity is poor, the oil content of an exhaust port is increased within a short time, and the environment is polluted.
SUMMERY OF THE UTILITY MODEL
The to-be-solved technical problem of the utility model is to overcome among the prior art oil spout screw vacuum pump with high costs, the efficiency is low, pollutes heavily, and the noise is big and defect such as function list provides an oil spout double screw vacuum pump control system.
The utility model discloses an above-mentioned technical problem is solved through following technical scheme:
the utility model provides an oil spout double-screw vacuum pump control system which characterized in that, it includes:
a vacuum pump body;
the air inlet filter is arranged at an air inlet of the vacuum pump body;
a first vacuum pressure sensor disposed at a front end of the intake filter;
the permanent magnet variable frequency motor drives the vacuum pump body;
the control unit is used for receiving a first air pressure signal detected by the first vacuum pressure sensor, wherein the control unit limits the permanent magnet variable frequency motor to operate at a constant power when the first air pressure signal is in a rough vacuum air pressure range.
The permanent magnet variable frequency motor controls the rotating speed according to the frequency provided by the frequency converter to drive the vacuum pump body to rotationally pump air, and the permanent magnet variable frequency motor and the vacuum pump body are connected and driven through a coupler. During control, the control unit sends a driving signal to the frequency converter through the signal shielded wire to drive the permanent magnet variable frequency motor to operate according to a given target rotating speed.
Under the rough vacuum state, the speed regulation characteristic of the permanent magnet variable frequency motor is utilized to effectively control the rotating speed of the permanent magnet variable frequency motor, so that the vacuum pump body operates from the lowest rotating speed to the rated rotating speed all the time according to the rated power of the motor, on one hand, the permanent magnet variable frequency motor can operate according to a PID (proportion integration differentiation) regulation mode during rough vacuum, the power is constant all the time, the rotating speed changes along with the change of air quantity, the instantaneous load during the operation of the vacuum pump body is increased, the speed is reduced through limiting the power, the operation of the machine without overload is ensured, and the vibration of the vacuum pump body is obviously improved. On the other hand, after the rotation speed of the rough vacuum state is modulated, the air extraction speed is stable, air is uniformly sucked, and under the condition that the oil injection quantity is not changed, the oil film forming speed is higher, the oil-gas separation treatment is improved, the oil content problem of the air outlet of the screw vacuum pump at the initial stage is effectively solved, and the oil content of exhaust air is controlled within 3 PPM.
Preferably, when the first air pressure signal is in a stable vacuum air pressure range, the control unit removes the limitation on the power of the permanent magnet variable frequency motor. Under the stable vacuum air pressure range, the permanent magnet variable frequency motor can run according to the actual working condition of a user, the vacuum pump bodies in different time periods run according to a PID (proportion integration differentiation) regulation mode, and the power is consumed according to the actual use working condition of the user in different time periods. The rotating speed changes along with the change of the air quantity, the requirements of customers on different working conditions are met, and the energy-saving effect is achieved.
Preferably, after the first air pressure signal reaches a stable vacuum air pressure range, the control unit controls the rotation speed of the permanent magnet variable frequency motor to be increased.
Preferably, after the first air pressure signal reaches a stable vacuum air pressure range and reaches a preset target value, the control unit controls the rotating speed of the permanent magnet variable frequency motor to be constant.
Preferably, when the first air pressure signal is lower than a dormancy target value, a saturated vacuum range is reached, and the control unit adjusts the permanent magnet variable frequency motor to enter dormancy.
Preferably, when the first air pressure signal is higher than a wake-up target value, the control unit adjusts the permanent magnet variable frequency motor to resume working.
Preferably, the oil injection double-screw vacuum pump control system further comprises a second vacuum pressure sensor, and the second vacuum pressure sensor is arranged at the rear end of the air inlet filter and is used for detecting a second air pressure signal.
Preferably, when the control unit detects that the pressure difference between the first air pressure signal and the second air pressure signal is greater than an alarm value, the control unit controls the permanent magnet variable frequency motor and stops the operation of the vacuum pump body.
A control method of an oil injection double-screw vacuum pump utilizes the oil injection double-screw vacuum pump control system, and is characterized by comprising the following steps:
detecting a first air pressure signal before an air inlet filter;
and when the first air pressure signal is in a rough vacuum air pressure range, the constant power of the permanent magnet variable frequency motor is limited through a control unit.
Preferably, when the first air pressure signal is in a stable vacuum air pressure range, the limitation on the constant power operation of the permanent magnet variable frequency motor is removed.
Preferably, the step of de-limiting the constant power operation of the permanent magnet variable frequency motor comprises:
after the first air pressure signal reaches a stable vacuum air pressure range from a rough vacuum air pressure range, the control unit controls the rotating speed of the permanent magnet variable frequency motor to be increased;
and after the first air pressure signal reaches a preset target value, the control unit controls the rotating speed of the permanent magnet variable frequency motor to be constant.
Preferably, after the step of controlling the constant rotating speed of the permanent magnet variable frequency motor by the control unit, the method further comprises the following steps:
when the first air pressure signal is lower than a dormancy target value, the saturated vacuum range is reached, and the control unit adjusts the permanent magnet variable frequency motor to enter dormancy.
The utility model discloses an actively advance the effect and lie in: through the application of the utility model, the vacuum production and manufacturing cost of the screw can be effectively controlled; meanwhile, the vibration of the pump body can be reduced, and the service life of the vacuum pump body is prolonged; the production requirements of customers in different production periods can be met, the power consumption of the vacuum pump is effectively controlled, and the energy is saved.
Drawings
Fig. 1 is a schematic structural view of an oil-injection twin-screw vacuum pump according to a preferred embodiment of the present invention.
Fig. 2 is a schematic structural diagram of a control system of an oil injection double-screw vacuum pump according to a preferred embodiment of the present invention.
Fig. 3 is a graph showing the vacuum degree and power consumption compared with the prior art according to the preferred embodiment of the present invention.
Fig. 4 is a graph showing the vacuum degree and the pumping speed compared with the prior art according to the preferred embodiment of the present invention.
Detailed Description
The present invention is further illustrated by way of the following examples, which are not intended to limit the scope of the invention.
Example 1
As shown in fig. 1 and fig. 2, the present embodiment discloses an oil injection twin-screw vacuum pump control system, which includes a permanent magnet variable frequency motor 1, a vacuum pump body 2, an oil-gas separation system 3, a cooling system 4, an auxiliary oil supply system 5, and a control system 6. The permanent magnet variable frequency motor 1 is used for driving the vacuum pump body 2.
In this embodiment, the permanent magnet variable frequency motor 1 is connected with the screw type vacuum pump body 2 through the coupler and the central bracket for transmission, gas is sucked and mixed with oil injection in the inner cavity of the vacuum pump body 2 to form a stable oil film, the stable oil film enters the exhaust port along with the operation of the vacuum pump body 2, the oil in the exhaust port is released due to the internal energy of gas molecules and becomes hot oil with higher temperature, and the exhaust port is provided with a temperature sensor for detecting the temperature of the exhaust port and providing analog quantity signals to the control unit 6. If the temperature exceeds the range, the control unit 6 switches to alarm and forbids the operation of the vacuum pump body 2.
In this embodiment, the oil-gas separation system 3 is connected to a steel pipe of a vacuum pump body through an exhaust steel pipe, after gas and oil enter the separation system and undergo a series of cyclone separation and mechanical collision, most of the oil sinks to the bottom of the barrel, the gas and trace oil undergo separation treatment by several conventional vacuum oil fine separators, the gas is released to a post-treatment device, the post-treatment device is connected to the oil-gas separation system through a steel pipe, and a pressure sensor, called an exhaust pressure sensor, is installed on the post-treatment device. A small amount of oil is sucked into the intake port of the vacuum pump body. The cooling system 4 cools the bulk of the hot oil of the oil separation system. The auxiliary oil supply system 5 supplies the cooled and filtered oil to each cavity of the vacuum pump body 2, and the required pressure points are different because the vacuum pump body 2 has a plurality of cavities and parts (such as a main body cavity, a gear box cavity and a bearing seat cavity). The control unit 6 is a controller, and collects data of each point to perform determination. The control unit 6 is connected with a frequency converter of the permanent magnet variable frequency motor 1 through a shielding signal wire, gives a frequency converter signal and controls the starting, stopping and rotating speed of the motor. The control unit 6 gives an on-off signal to the electromagnetic valve by the frequency converter, and controls the opening and closing of the air inlet valve to control the opening and closing of the vacuum pump body 2.
The oil injection double-screw vacuum pump control system of the embodiment further comprises an air inlet filter, and the air inlet filter is arranged at an air inlet of the vacuum pump body 2. The air inlet of the vacuum pump body 2 is provided with an air inlet filter and an air inlet valve of conventional vacuum equipment, and is connected with a buffer tank of the conventional vacuum equipment and a front end pipeline thereof. The embodiment also comprises a first vacuum pressure sensor which is arranged at the front end of the air inlet filter (connected with the buffer tank and a front end pipeline thereof).
As shown in fig. 1 and 2, the control unit 6 of the present embodiment is configured to receive a first air pressure signal detected by a first vacuum pressure sensor. The first vacuum pressure sensor detects the vacuum degree required by the actual working condition of the user and provides analog quantity required by the control unit 6 actually, and the first vacuum pressure sensor is called as a pressure sensor before air filtration. Wherein, when the first air pressure signal is in the rough vacuum air pressure range, the control unit 6 limits the permanent magnet variable frequency motor 1 to operate at a constant power.
The permanent magnet variable frequency motor 1 controls the rotating speed according to the frequency provided by the frequency converter to drive the vacuum pump body 2 to rotationally pump air, and the permanent magnet variable frequency motor 1 and the vacuum pump body 2 are connected and driven through a coupler. During control, the control unit 6 sends a driving signal to the frequency converter through the signal shielded wire to drive the permanent magnet variable frequency motor 1 to operate according to a given target rotating speed.
Under the rough vacuum state, the speed regulation characteristic of the permanent magnet variable frequency motor 1 is utilized to effectively control the rotating speed of the permanent magnet variable frequency motor 1, so that the vacuum pump body 2 operates from the lowest rotating speed to the rated rotating speed all the time according to the rated power of the motor 1, on one hand, the permanent magnet variable frequency motor 1 can operate according to a PID (proportion integration differentiation) regulation mode during rough vacuum, the power is constant all the time, the rotating speed changes along with the change of air quantity, the speed reduction operation is performed by limiting the power when the instantaneous load of the operation of the vacuum pump body 2 is increased, the machine is ensured not to operate in an overload mode, and the vibration of the vacuum pump body 2 is obviously improved. On the other hand, after the rotation speed of the rough vacuum state is modulated, the air extraction speed is stable, air is uniformly sucked, and under the condition that the oil injection quantity is not changed, the oil film forming speed is higher, the oil-gas separation treatment is improved, the oil content problem of the air outlet of the screw vacuum pump at the initial stage is effectively solved, and the oil content of exhaust air is controlled within 3 PPM.
In this embodiment, when the first air pressure signal is within the stable vacuum air pressure range, the control unit 6 removes the limitation on the power of the permanent magnet variable frequency motor 1. Under the stable vacuum air pressure range, the permanent magnet variable frequency motor 1 can run according to the actual working condition of a user, the vacuum pump body 2 runs in a PID (proportion integration differentiation) regulation mode in different time periods, and the power is consumed according to the actual working condition of the user in different time periods. The rotating speed changes along with the change of the air quantity, the requirements of customers on different working conditions are met, and the energy-saving effect is achieved.
In this embodiment, after the first air pressure signal reaches the stable vacuum air pressure range, the control unit 6 controls the rotation speed of the permanent magnet variable frequency motor 1 to increase. After the first air pressure signal reaches the stable vacuum air pressure range and reaches a preset target value, the control unit 6 controls the rotating speed of the permanent magnet variable frequency motor 1 to be constant.
In this embodiment, when the first air pressure signal is lower than a sleep target value, the saturated vacuum range is reached, and the control unit 6 adjusts the permanent magnet variable frequency motor 1 to enter the sleep mode. When the first air pressure signal is higher than a wakeup target value, the control unit 6 adjusts the permanent magnet variable frequency motor 1 to resume working.
In this embodiment, the oil injection double-screw vacuum pump control system further includes a second vacuum pressure sensor disposed at a rear end of the air intake filter and configured to detect a second air pressure signal. When the control unit 6 detects that the pressure difference between the first air pressure signal and the second air pressure signal is greater than an alarm value, the control unit 6 controls the permanent magnet variable frequency motor 1 and stops the operation of the vacuum pump body 2. And a second vacuum pressure sensor which is arranged at the rear end of the air inlet filter (connected with the air inlet valve) and is used for detecting the vacuum degree after filtration, is called as an air filtration pressure sensor, has a pressure difference with the first vacuum pressure sensor and is used for detecting the actual cleanliness of the medium gas used by a client. If the pressure difference between the vacuum pump body and the vacuum pump body is too large, the control unit 6 switches to alarm and forbids the operation of the vacuum pump body.
The present embodiment makes a judgment by detecting the pressure of 3 sections and the temperature of 1 section in the system. The pressure at the front end and the rear end (the front end and the rear end of the air filter) is detected, so that the pressure difference before and after air filtration is calculated, large-area impurities are prevented from entering the vacuum pump body 2, the vacuum pump body 2 is sucked for protection, and meanwhile, the operation and the rotating speed of the vacuum pump body 2 are controlled according to the pressure before air filtration (the actual vacuum requirement of a customer). The control of the rotating speed can effectively avoid the energy consumption increase caused by useless rough vacuum of a relative client and the energy consumption of the actual demand of the client under the completely matched stable vacuum, and overcome the defects of vibration and noise of the pump body under the rough vacuum caused by overlarge air suction quantity.
In the embodiment, the rough vacuum can be set to 700mbar to 1013mbar, the stable vacuum can be set to 700mbar to 20mbar, and the saturated vacuum can be set to 20 mbar.
As shown in table one below, and as can be seen in conjunction with fig. 3 and 4, the rotational speed of the power in the present apparatus was significantly controlled during the operation of the vacuum gauge indicating 793.28mbar to 396.00 mbar. In the embodiment, the power of the permanent magnet variable frequency motor 1 is controlled to be 35kw, so that the power of the existing equipment is prevented from exceeding the service coefficient of the motor.
TABLE I comparison of this example with existing design parameters
The embodiment also discloses a control method of the oil injection double-screw vacuum pump, and the control system of the oil injection double-screw vacuum pump comprises the following steps:
detecting a first air pressure signal before an air inlet filter;
and when the first air pressure signal is in a rough vacuum air pressure range, the constant power of the permanent magnet variable frequency motor is limited through a control unit.
Preferably, when the first air pressure signal is in a stable vacuum air pressure range, the limitation on the constant power operation of the permanent magnet variable frequency motor is removed.
The step of releasing the limitation on the constant power operation of the permanent magnet variable frequency motor comprises the following steps:
after the first air pressure signal reaches a stable vacuum air pressure range from a rough vacuum air pressure range, the control unit controls the rotating speed of the permanent magnet variable frequency motor to be increased; and after the first air pressure signal reaches a preset target value, the control unit controls the rotating speed of the permanent magnet variable frequency motor to be constant.
After the step of controlling the constant rotating speed of the permanent magnet variable frequency motor by the control unit, the method also comprises the following steps:
when the first air pressure signal is lower than a dormancy target value, the saturated vacuum range is reached, and the control unit adjusts the permanent magnet variable frequency motor to enter dormancy.
Through the application of the utility model, the vacuum production and manufacturing cost of the screw can be effectively controlled; meanwhile, the vibration of the pump body can be reduced, and the service life of the vacuum pump body is prolonged; the production requirements of customers in different production periods can be met, the power consumption of the vacuum pump is effectively controlled, and the energy is saved.
Although specific embodiments of the present invention have been described above, it will be understood by those skilled in the art that this is by way of example only and that the scope of the invention is defined by the appended claims. Various changes and modifications to these embodiments may be made by those skilled in the art without departing from the spirit and the principles of the present invention, and these changes and modifications are all within the scope of the present invention.
Claims (5)
1. The utility model provides an oil spout double-screw vacuum pump control system which characterized in that, it includes:
a vacuum pump body;
the air inlet filter is arranged at an air inlet of the vacuum pump body;
a first vacuum pressure sensor disposed at a front end of the intake filter;
the permanent magnet variable frequency motor drives the vacuum pump body;
the control unit is used for receiving a first air pressure signal detected by the first vacuum pressure sensor, wherein the first air pressure signal is in a rough vacuum air pressure range, the control unit limits the permanent magnet variable frequency motor to operate at a constant power, the first air pressure signal is in a stable vacuum air pressure range, the control unit removes the limitation on the power of the permanent magnet variable frequency motor, after the first air pressure signal reaches the stable vacuum air pressure range, the control unit controls the rotating speed of the permanent magnet variable frequency motor to be increased, and after the first air pressure signal reaches the stable vacuum air pressure range and reaches a preset target value, the control unit controls the rotating speed of the permanent magnet variable frequency motor to be constant.
2. An oil injection twin screw vacuum pump control system as claimed in claim 1, wherein the control unit regulates the pm variable frequency motor to go to sleep when the first air pressure signal is below a sleep target value to reach a saturated vacuum range.
3. An oil injection twin screw vacuum pump control system as claimed in claim 2, wherein said control unit regulates said pm variable frequency motor to resume operation when said first air pressure signal is above a wake-up target value.
4. An oil injection twin screw vacuum pump control system as claimed in claim 1, further comprising a second vacuum pressure sensor disposed at a rear end of said air intake filter for detecting a second air pressure signal.
5. An oil injection twin screw vacuum pump control system according to claim 4, wherein the control unit controls the permanent magnet variable frequency motor and stops the operation of the vacuum pump body when the control unit detects that the pressure difference between the first air pressure signal and the second air pressure signal is greater than an alarm value.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202022466278.1U CN214424700U (en) | 2020-10-30 | 2020-10-30 | Oil injection double-screw vacuum pump control system |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202022466278.1U CN214424700U (en) | 2020-10-30 | 2020-10-30 | Oil injection double-screw vacuum pump control system |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN214424700U true CN214424700U (en) | 2021-10-19 |
Family
ID=78059550
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202022466278.1U Active CN214424700U (en) | 2020-10-30 | 2020-10-30 | Oil injection double-screw vacuum pump control system |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN214424700U (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114739106A (en) * | 2022-04-25 | 2022-07-12 | 海信（山东）冰箱有限公司 | Refrigerator and control method thereof |
-
2020
- 2020-10-30 CN CN202022466278.1U patent/CN214424700U/en active Active
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114739106A (en) * | 2022-04-25 | 2022-07-12 | 海信（山东）冰箱有限公司 | Refrigerator and control method thereof |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US9062684B2 (en) | Method of operating a pumping system | |
| KR20120101000A (en) | Pumping method and device with low power consumption | |
| CN1793746A (en) | Method for automatic regulating and controlling cooling water and frozen water flow of central air conditioning system | |
| CN214424700U (en) | Oil injection double-screw vacuum pump control system | |
| CN104822943A (en) | Vacuum pump system for evacuating chamber, and method for controlling vacuum pump system | |
| JP4924855B1 (en) | Compressor number control system | |
| JP3262011B2 (en) | Operating method of screw compressor and screw compressor | |
| WO2015198647A1 (en) | Gas compressor | |
| WO2021084821A1 (en) | Compressor, monitoring system, and method of monitoring compressor | |
| CN109477485A (en) | For reducing the method and related pump unit of the pressure in loadlock | |
| JP6608394B2 (en) | Vacuum pumping method and vacuum pump system | |
| JP5506830B2 (en) | Screw compressor | |
| EP2533875A1 (en) | Compressed air supply for the operation of moving bed filters | |
| CN114439749A (en) | Oil injection double-screw vacuum pump control system and control method thereof | |
| EP1320683B1 (en) | Variable speed oil-injected screw compressors | |
| WO2006106302A1 (en) | Temperature control apparatus | |
| JP4792383B2 (en) | Operation method of screw compressor | |
| JP6742509B2 (en) | Liquid supply type gas compressor | |
| JP3914713B2 (en) | Screw compressor operating method and screw compressor | |
| CN215170770U (en) | Oil injection screw type vacuum equipment | |
| CN219101582U (en) | Variable-frequency energy-saving low-noise oil-free screw vacuum pump | |
| JP7150869B2 (en) | Liquid-fed gas compressor | |
| JP6454607B2 (en) | Oil-free compressor | |
| JP5422431B2 (en) | Control method of fluid compressor and fluid compressor | |
| WO2024009233A1 (en) | Method for controlling an air-cooled compressor or vacuum pump device and an air-cooled compressor or vacuum pump device |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| GR01 | Patent grant | ||
| GR01 | Patent grant |