CN212929564U - Constant-pressure variable-frequency speed-regulating oil supply system based on PLC control - Google Patents

Abstract

The utility model discloses a constant voltage variable frequency speed regulation oil supply system based on PLC control, when there is dust on the display screen, can pull the plate body, thus make the slider slide in the spout, the plate body slides along the length extending direction of spout simultaneously, the dust removal strip moves on the display screen, thereby realizes the erasure of the dust on the display screen, and is more convenient for the user to need to look for the wiping cloth on the spot when erasing the dust on the display screen; the frequency converter is controlled by the internal program of the PLC programmable controller to adjust, the pressure set value is set at will according to actual needs, the working condition of the oil pump is adjusted according to the pressure difference, constant-pressure oil supply is realized, the pressure fluctuation is small when the oil pump is started, the reliability is high, the efficiency is high, the energy-saving effect is obvious, the dynamic response speed is high, and the water hammer pressure is small. Selecting different pressure setting ranges enables optimal control and stability control of the oil supply.

Description

Constant-pressure variable-frequency speed-regulating oil supply system based on PLC control

Technical Field

The utility model relates to an oil feeding system technical field especially relates to a constant voltage variable frequency speed governing oil feeding system based on PLC control.

Background

The constant-pressure variable-frequency speed-regulating oil supply system based on PLC control is mainly used for conveying oil to storage tanks, use tanks, oil trucks, tank trucks, airplanes and the like in places such as large-scale oil storage and transportation (oil receiving and distribution operation) of oil depots, medium petroleum and petrochemical industries and the like, comprises an oil pump, a power electric cabinet of a distribution room and the like which are arranged in a pump room, and is used for improving the efficiency of oil conveying and ensuring safe and efficient oil supply, so that the constant-pressure variable-frequency speed-regulating oil supply system based on PLC control is provided with the constant-pressure variable-frequency speed-regulating oil supply system based on PLC control at present, a control panel is required to be used in the constant-pressure variable-frequency speed-regulating oil supply system based on PLC control, but after a display screen on the control panel is used for a period of time, a lot of dust is adsorbed on the surface of the screen due to the electrostatic effect of, when the dust on the display screen is erased, the wiping cloth needs to be found on site, which is very inconvenient.

SUMMERY OF THE UTILITY MODEL

An object of the utility model is to provide a constant voltage Variable Frequency Speed Governing (VFSG) oil feeding system based on PLC control aims at solving the user among the prior art and erases the technical problem that the dust is very inconvenient on the display screen.

In order to achieve the above object, the utility model discloses a constant voltage variable frequency speed regulation oil supply system based on PLC control, including PLC programmable controller and control panel, control panel with PLC programmable controller electric connection, control panel includes display screen, framework and dust removal subassembly, the framework with display screen fixed connection, and enclose in the periphery side of display screen, the spout has on the both ends that the framework set up relatively, each all be provided with the slider in the spout, the dust removal subassembly includes plate body, installation piece, dust removal strip, elastic component and dwang, the both ends of plate body respectively with two slider fixed connection, and the plate body is located the top of display screen, the plate body is close to one end of display screen has the recess, the installation piece is arranged in the below of plate body, the dust removal strip with installation piece fixed connection, and be located the below of installation piece, just remove dust the strip with the display screen contact, the one end of elastic component with plate body fixed connection, the other end of elastic component with installation piece fixed connection, the elastic component is located in the recess, the quantity of elastic component is two, two the elastic component sets up relatively, the dwang with plate body threaded connection, just the one end of dwang is run through the plate body, and with the installation piece supports and holds.

Wherein, constant voltage variable frequency speed governing oil feeding system based on PLC control still includes signal acquisition unit and pipe network, the signal acquisition unit with PLC programmable controller electric connection, just the signal acquisition unit sets up on the pipe network.

The constant-voltage variable-frequency speed regulation oil supply system based on PLC control further comprises a switch switching unit, and the switch switching unit is electrically connected with the PLC.

The constant-voltage variable-frequency speed regulation oil supply system based on PLC control further comprises a frequency converter, and the frequency converter is electrically connected with the switch switching unit.

Wherein, constant voltage variable frequency speed governing oil feeding system based on PLC control still includes the oil pump, the oil pump with converter electric connection, just the oil pump pass through the valve with pipe network fixed connection.

The constant-voltage variable-frequency speed regulation oil supply system based on PLC control further comprises an alarm unit, and the alarm unit is electrically connected with the PLC.

The beneficial effects of the utility model are embodied in: when dust exists on the display screen, the plate body can be pulled, the plate body is stressed, so that the sliding block slides in the sliding groove, meanwhile, the plate body slides along the length extending direction of the sliding groove, the dust removing strip moves on the display screen, and therefore the dust on the display screen is erased, and the dust remover is more convenient for a user to find wiping cloth on site when the user erases the dust on the display screen; in addition when dust removal strip with when contact is inseparable enough between the display screen, the accessible rotates the dwang makes the dwang moves towards the direction of installation piece to support and hold the installation piece orientation display screen direction removes, makes then dust removal strip with contact is inseparabler between the display screen, will dust on the display screen is erased more cleanly.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to these drawings without creative efforts.

Fig. 1 is the utility model discloses a constant voltage variable frequency speed governing oil feeding system's schematic diagram based on PLC control.

Fig. 2 is a schematic circuit diagram of the frequency converter of the present invention.

Fig. 3 is a circuit diagram of the operation principle of the programmable controller of the present invention.

Fig. 4 is a schematic diagram of a fault indicator lamp of the frequency converter of the present invention.

Fig. 5 is a schematic circuit diagram of the variable frequency feedback rate of the oil pump of the present invention.

Fig. 6 is a circuit diagram of the connection terminal of the programmable controller according to the present invention.

Fig. 7 is a schematic structural diagram of the control panel of the present invention.

Fig. 8 is an enlarged view of the structure of fig. 2.

Fig. 9 is a plan view of the control panel of the present invention.

Fig. 10 is a sectional view of the a-a line structure of fig. 4.

The device comprises a programmable logic controller (1), a Programmable Logic Controller (PLC), a control panel (2), a display screen (21), a frame body (22), a sliding chute (221), a dust removal component (23), a plate body (231), an installation sheet (232), a dust removal strip (233), an elastic piece (234), a rotating rod (235), a groove (236), a telescopic rod (237), a handle (238), an anti-skid pattern (239), a sliding block (24), a signal acquisition unit (3), a pipe network (4), a switch switching unit (5), a frequency converter (6), an oil pump (7) and an alarm unit (8).

Detailed Description

Reference will now be made in detail to embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein like reference numerals refer to the same or similar elements or elements having the same or similar function throughout. The embodiments described below with reference to the drawings are exemplary and intended to be used for explaining the present invention, and should not be construed as limiting the present invention.

In the description of the present invention, it is to be understood that the terms "length", "width", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", and the like indicate orientations or positional relationships based on those shown in the drawings, and are merely for convenience of description and simplicity of description, and do not indicate or imply that the device or element being referred to must have a particular orientation, be constructed and operated in a particular orientation, and thus, should not be construed as limiting the present invention. In addition, in the description of the present invention, "a plurality" means two or more unless specifically limited otherwise.

Referring to fig. 1 to 10, the present invention provides a constant-pressure variable-frequency speed-regulating oil supply system based on PLC control, including a PLC programmable controller 1 and a control panel 2, where the control panel 2 is electrically connected to the PLC programmable controller 1, the control panel 2 includes a display screen 21, a frame 22 and a dust-removing assembly 23, the frame 22 is fixedly connected to the display screen 21 and surrounds the periphery of the display screen 21, sliding slots 221 are provided at two opposite ends of the frame 22, a sliding block 24 is provided in each sliding slot 221, the dust-removing assembly 23 includes a plate body 231, an installation piece 232, a dust-removing strip 233, an elastic member 234 and a rotating rod 235, two ends of the plate body 231 are respectively fixedly connected to the two sliding blocks 24, the plate body 231 is located above the display screen 21, a groove 236 is provided at one end of the plate body 231 close to the display screen 21, the installation piece 232 is arranged in the below of plate body 231, dust removal strip 233 with installation piece 232 fixed connection, and be located installation piece 232's below, just dust removal strip 233 with display screen 21 contacts, the one end of elastic component 234 with plate body 231 fixed connection, the other end of elastic component 234 with installation piece 232 fixed connection, elastic component 234 is located in the recess 236, the quantity of elastic component 234 is two, two the elastic component 234 sets up relatively, dwang 235 with plate body 231 threaded connection, just the one end of dwang 235 runs through plate body 231, and with installation piece 232 supports and holds.

In this embodiment, the elastic member 234 is a compression spring, when the elastic member 234 is completely located in the groove 236, the elastic member 234 is in a natural state, i.e. is not stretched or compressed, the plate 231 is in contact with the mounting plate 232, the dust removing strip 233 is a sponge strip, when dust is on the display screen 21, the plate 231 can be pulled, when the plate 231 is pulled, a hand can be put on the rotating rod 235 to pull the plate 231, which is easier and more labor-saving, when the plate 231 is stressed, so that the sliding block 24 slides in the sliding slot 221, and simultaneously the plate 231 slides along the length extension direction of the sliding slot 221, and the dust removing strip 233 moves on the display screen 21, so that the dust on the display screen 21 can be erased through the left and right movement of the dust removing strip 233, compared with the situation that a user needs to find the wiping cloth on site when erasing dust on the display screen 21, the dust wiping device is more convenient; in addition, when the dust removing strip 233 is not tightly contacted with the display screen 21, the rotating rod 235 can be rotated to enable the rotating rod 235 to move towards the direction of the mounting piece 232 and abut against the mounting piece 232, at this time, the elastic piece 234 is stretched, the rotating rod 235 abuts against the mounting piece 232 and moves towards the direction of the display screen 21, and then the dust removing strip 233 is more tightly contacted with the display screen 21, so that dust on the display screen 21 is more cleanly removed.

Further, constant voltage variable frequency speed governing oil feeding system based on PLC control still includes signal acquisition unit 3 and pipe network 4, signal acquisition unit 3 with 1 electric connection of PLC programmable controller, just signal acquisition unit 3 sets up on the pipe network 4.

The constant-voltage variable-frequency speed regulation oil supply system based on PLC control further comprises a switch switching unit 5, and the switch switching unit 5 is electrically connected with the PLC programmable controller 1.

Constant voltage variable frequency speed governing oil feeding system based on PLC control still includes converter 6, converter 6 with switch switching unit 5 electric connection.

Constant voltage variable frequency speed governing oil feeding system based on PLC control still includes oil pump 7, oil pump 7 with 6 electric connection of converter, just oil pump 7 pass through the valve with 4 fixed connection of pipe network.

Constant voltage variable frequency speed governing oil feeding system based on PLC control still includes alarm unit 8, alarm unit 8 with PLC programmable controller 1 electric connection.

In the present embodiment, in order to improve the efficiency of the motor control, the prior art is to change the control mode of the motor to the variable frequency starting, the starting time is less than 15 seconds, after the starting is finished, the variable frequency operation is performed, the operation frequency is automatically adjusted, and the operation rotating speed is less than 2900 rpm. Then the following problems exist: (1) in the starting process, the oil pump 7 is controlled by adopting a soft start and self-coupling voltage reduction starting mode, the mode is unstable in operation, the alternating current contactor is frequently switched, the water hammer effect is easily generated to cause the vibration of the pipe network 4, the pressure is unstable, the working efficiency is low, and the like, and the equipment failure rate is increased when the oil pump is frequently started every time. (2) Because the uncertain factor of 4 terminal opening oil-sending mouths of pipe network quantity, need the linkage of many pumps, belong to large-traffic worker in addition and always, the load increases to higher requirement has been proposed to the response time of equipment, on satisfying the basis of flow and pressure biparametric performance, safe efficient guarantee is the problem that needs to solve at present urgently, and original control mode can not satisfy the operation requirement for solving above-mentioned problem, the utility model discloses with PLC programmable controller 1 and converter 6 design for the core, with the help of the powerful and nimble control function of PLC with the control function of the good variable frequency speed governing performance of converter 6 has realized the control of constant voltage fuel feeding. The system adopts a PLC internal program to control the frequency converter 6 to adjust, the pressure set value is set at will according to actual needs, the working condition of the oil pump 7 is adjusted according to the pressure difference, the operating frequency is 25HZ-50HZ to realize constant-pressure oil supply, the oil pump 7 is enabled to operate at high efficiency all the time, the pressure fluctuation is small when the system is started, and the system can be controlled within 5% of the set value.

The constant-pressure oil supply control system designed based on the PLC 1 and the frequency converter 6 has the advantages of high reliability, high efficiency, obvious energy-saving effect, high dynamic response speed and small water hammer pressure. Different pressure setting ranges are selected, so that the oil supply time is reduced, the oil supply guarantee capacity is improved, a better efficient energy-saving mode is achieved, and optimal control and stability control of oil supply are realized.

Specifically, the method comprises the following steps: a constant-pressure variable-frequency speed-regulating oil supply system based on PLC control comprises a signal acquisition unit 3, a PLC programmable controller 1, a frequency converter 6, a switch switching unit 5, an oil pump 7 and a pipe network 4, wherein the signal acquisition unit 3 acquires signals of the pipe network 4 and transmits the signals to the PLC programmable controller 1, the PLC programmable controller 1 sends an instruction after operation judgment to control the frequency converter 6 and the switch switching unit 5 to act, so that the operation of the oil pump 7 is controlled, the PLC programmable controller 1 has a power-on self-checking function, if the signals of the transmitter (fault or disconnection) can not be acquired, the PLC programmable controller is defaulted to be in a fault state, when the operating frequency is lower limit after the pump is operated, the pipeline pressure is lower than a set pressure value (a built-in pressure value on a program, no manual setting is needed), and the PLC programmable controller defaults to be in the, the frequency is not increased, a mechanical explosion-proof electric contact pressure gauge is additionally arranged, whether the pressure transmitter is normal or not is judged in various modes, and misjudgment is prevented. The actuating mechanism of the whole system is composed of a plurality of oil pumps 7, the oil pumps 7 are speed regulating pumps, the oil pumps 7 are controlled by the frequency converter 6 and can be subjected to frequency conversion adjustment, and the rotating speed of the motor is changed according to the change of the oil consumption so as to maintain the constant pressure of the pipe network 4.

The signal acquisition unit 3 has the characteristics of stable signal and strong buffering function, and comprises a pressure sensor and an explosion-proof electric contact pressure gauge, wherein the pressure sensor adopts an explosion-proof pressure transmitter (4-20 mA current), and in the system control process, signals needing to be detected comprise an oil outlet oil pressure signal and an alarm signal of the tap oil, namely an official network pressure signal: it reflects the oil pressure value of the pipe network 4, which is the main feedback signal (analog signal) for constant pressure oil supply control. Alarm signal: it reflects whether the system is operating normally, whether the oil pump 7 is overloaded, and whether the frequency converter 6 is abnormal. The signal is a switching value signal.

The PLC 1 is the core of the whole variable-frequency constant-pressure oil supply control system, the signal acquisition unit 3 acquires working conditions, pressure and alarm signals in the system, analyzes data information from a man-machine interface and a communication interface, implements a control algorithm to obtain a control scheme for an actuating mechanism, and controls the actuating mechanism (namely the oil pump 7) through the frequency converter 6 and the switch switching unit 5. The frequency converter 6 is a unit for controlling the rotating speed of the oil pump 7, and the frequency converter 6 changes the operating frequency of the speed regulating pump according to a control signal sent by the PLC 1 to complete the rotating speed control of the speed regulating pump. The switch switching unit 5 is composed of a group of electrical elements such as a contactor, a protective relay, a change-over switch and the like. For completing switching, manual/automatic switching, etc. of the oil pump 7 under the control of the oil supply controller.

The PLC 1 is also connected with the control panel 2 and the alarm unit 8. Through the display screen 21 on the control panel 2, wherein the display screen 21 is a touch display screen 21, a user can change the set pressure and modify some system settings to meet the requirements of different processes, and meanwhile, the user can also know some operation conditions of the system and the working state of the equipment from the display screen 21. The human-computer interface can also monitor the operation process of the system and display the alarm.

The alarm unit 8 is an important component of the overall system. As the system can be suitable for different oil supply fields, in order to ensure the safe, reliable and stable operation of the system and prevent faults caused by motor overload, frequency converter 6 alarm, excessive fluctuation of a power grid, oil supply interruption, oil outlet overpressure and the like, the system has to monitor various alarm amounts, a PLC (programmable logic controller) judges alarm types, displays and protects action control, and a red indicator lamp is used for displaying on a control cabinet so as to avoid unnecessary loss.

The working principle is as follows: and (3) turning on an air switch, putting the oil supply system into operation, turning on a manual switch and an automatic switch to automatically turn on the system, and enabling the system to enter a full-automatic operation state, wherein the program in the PLC firstly switches on KA1 and starts the frequency converter 6. And comparing, adjusting and calculating according to a pressure set value (set according to the pressure requirement of the pipe network 4) and a pressure actual value (from a pressure sensor), and outputting a frequency given signal to the frequency converter 6. And the frequency converter 6 controls the rotating speed of the oil pump 7 according to a frequency given signal and preset acceleration time so as to ensure that the pressure of the pipe network 4 is kept within a pressure value range of a pressure set value and a constant pressure value, and constant pressure control is realized. And meanwhile, when the operating frequency of the frequency converter 6 reaches the upper limit, a frequency reaching signal is sent to the PLC 1, and the PLC 1 judges whether to start the second oil pump 7 or the third oil pump 7 according to the upper and lower limit signals of the pressure of the pipe network 4 and the signal whether the operating frequency of the frequency converter 6 reaches the upper limit. When the operating frequency of the frequency converter 6 reaches the upper limit value of the frequency and is kept for a period of time, the PLC 1 can quickly start the next oil pump 7 to operate in a frequency conversion mode. At the moment, the PLC 1 can continuously carry out analysis, calculation and judgment through a detection signal transmitted by a remote transmission pressure gauge, and further control the operating frequency of the frequency converter 6, so that the pipe pressure is kept within the range of the pressure set value constant pressure value.

The pump increasing working process: starting self-checking, starting an automatic control button, gradually increasing the frequency of the 1# oil pump 7 from 0 to Fx11 (corresponding to a constant pressure Pw2), wherein Fx11 is lower than Fx1, setting a frequency Fx1 value, setting a frequency Fx1 value to be in a middle value of the operating frequency of the oil pump 7 when all valves are closed, stopping the 1# oil pump 7 at the moment, finishing the preparation work, enabling a pumping operator to check the operating state of the pump only, judging whether a pressure display value on a touch screen is consistent with a reading value of a pressure gauge on a pressure stabilizing device or not, and enabling an error to be larger than 0.05Mpa, when oil is prepared to be delivered, reducing the pressure to Px3, automatically starting the first oil pump 7 to perform variable frequency operation, when the pump is operated to the highest 50HZ, when the pipeline pressure Px11 is lower than the pump pressure, automatically starting the second pump, when the second oil pump 7 is performed variable frequency operation to the highest 50HZ, and when the pipeline pressure Px11 is lower than the pump pressure, the third oil pump 7 is automatically started to run, so that the pipeline pressure is balanced

Reducing the working process of the pump: when the frequency of the third oil pump 7 is reduced to Fx2, the third oil pump 7 is stopped, after the third oil pump 7 is stopped and operates for several seconds, the frequency of the second oil pump 7 is still reduced to Fx2, the second oil pump 7 is stopped, after the second oil pump 7 is stopped and operates for several seconds, the frequency of the first oil pump 7 is still reduced to Fx1, the first oil pump 7 is stopped, one oil pump 7 is always kept in working operation, the pipeline pressure cannot exceed the maximum pressure setting Px1, when the pipeline pressure exceeds Px1, all the oil pumps 7 are completely stopped, and the Px1 is a safe pressure value.

In summary, the following steps: the utility model discloses a1 inside program control of PLC programmable controller converter 6 is adjusted, according to actual need sets for the pressure setting value at will, according to the pressure differential adjustment the behavior of oil pump 7 realizes the constant voltage fuel feeding, makes oil pump 7 moves under the high efficiency all the time, and the pressure oscillation is little when starting, and the reliability is high, efficient, energy-conserving effect is showing, dynamic response is fast, and water hammer pressure is little. Different pressure setting ranges are selected, so that the oil supply time is reduced, the oil supply guarantee capacity is improved, a better efficient energy-saving mode is achieved, and optimal control and stability control of oil supply are realized.

Further, the dust removing assembly 23 further comprises a telescopic rod 237, one end of the telescopic rod 237 is fixedly connected with the mounting plate 232, the other end of the telescopic rod 237 is fixedly connected with the plate body 231, and the elastic member 234 is sleeved outside the telescopic rod 237.

In this embodiment, the telescopic rod 237 is formed by sleeving two rod bodies, so as to achieve the telescopic function of the telescopic rod 237, wherein the telescopic rod 237 is arranged to increase the connection stability between the plate 231 and the mounting piece 232.

Further, the dust removing assembly 23 further comprises a handle 238, and the handle 238 is fixedly connected to the rotating rod 235 and is located at one end of the rotating rod 235 far away from the installation sheet 232. The handle 238 has an anti-slip pattern 239 on the outer side wall.

In this embodiment, the setting of handle 238 can facilitate the user to rotate dwang 235 simultaneously set up on the handle 238 anti-skidding line 239 can make the user hand grip when handle 238, can increase frictional force between handle 238 and the hand, and the user is rotating during the dwang 235, it is laborsaving to relax more.

While the invention has been described with reference to a preferred embodiment, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention.

Claims (6)

1. A constant-pressure variable-frequency speed-regulating oil supply system based on PLC control is characterized in that,

the dust removal device comprises a PLC programmable controller and a control panel, wherein the control panel is electrically connected with the PLC programmable controller, the control panel comprises a display screen, a frame body and a dust removal assembly, the frame body is fixedly connected with the display screen and surrounds the periphery side of the display screen, sliding grooves are formed in the two opposite ends of the frame body, each sliding groove is internally provided with a sliding block, the dust removal assembly comprises a plate body, an installation piece, a dust removal strip, an elastic piece and a rotating rod, the two ends of the plate body are fixedly connected with the two sliding blocks respectively, the plate body is positioned above the display screen, a groove is formed in one end, close to the display screen, of the plate body, the installation piece is arranged below the plate body, the dust removal strip is fixedly connected with the installation piece and is positioned below the installation piece, and the dust removal strip is in contact with the display screen, the one end of elastic component with plate body fixed connection, the other end of elastic component with installation piece fixed connection, the elastic component is located in the recess, the quantity of elastic component is two, two the elastic component sets up relatively, the dwang with plate body threaded connection, just the one end of dwang runs through the plate body, and with the installation piece supports and holds.

2. The PLC-based constant-pressure variable-frequency speed-regulating oil supply system as claimed in claim 1,

constant voltage variable frequency speed governing oil feeding system based on PLC control still includes signal acquisition unit and pipe network, the signal acquisition unit with PLC programmable controller electric connection, just the signal acquisition unit sets up on the pipe network.

3. The PLC-based constant-pressure variable-frequency speed-regulating oil supply system as claimed in claim 2,

the constant-voltage variable-frequency speed regulation oil supply system based on PLC control further comprises a switch switching unit, and the switch switching unit is electrically connected with the PLC.

4. The PLC-based constant-pressure variable-frequency speed-regulating oil supply system as claimed in claim 3,

the constant-voltage variable-frequency speed regulation oil supply system based on PLC control further comprises a frequency converter, and the frequency converter is electrically connected with the switch switching unit.

5. The PLC-based constant-pressure variable-frequency speed-regulating oil supply system as claimed in claim 4,

constant voltage variable frequency speed governing oil feeding system based on PLC control still includes the oil pump, the oil pump with converter electric connection, just the oil pump pass through the valve with pipe network fixed connection.

6. The PLC-based constant-pressure variable-frequency speed-regulating oil supply system as claimed in claim 5,

the constant-voltage variable-frequency speed regulation oil supply system based on PLC control further comprises an alarm unit, and the alarm unit is electrically connected with the PLC.

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