WO2013109022A1

WO2013109022A1 - Auxiliary control device for compressor and auxiliary control method for compressor thereof

Info

Publication number: WO2013109022A1
Application number: PCT/KR2013/000268
Authority: WO
Inventors: 김금균
Original assignee: Kim Keum Kyun
Priority date: 2012-01-20
Filing date: 2013-01-14
Publication date: 2013-07-25
Also published as: CN104066995A; KR101174430B1; CN104066995B

Abstract

The present invention relates to an auxiliary control device for a compressor comprising: an inverter pack control unit (23) for stopping the operation of a compressor, selecting an operational condition such as a manual mode and an automatic mode or the like, and inputting a target input value; an operation control unit (12) for automatically detecting a load operation state or a no-load operation state of the compressor on the basis of a signal for an inputted current state when the compressor (8) is operated, preventing a high-speed idling operation when in the no-load operation state, performing a standby function for stopping a motor when the no-load operation continues for a predetermined time and a rapid re-operation prevention function, and separating a power source for driving the motor of the compressor and an operational power source from each other; and a pressure control unit (22) for comparing the target pressure value predetermined by a user with the pressure value which is detected from a receiver tank and outputted through a pressure sensor, and outputting the current according to a deviation value to the inverter, wherein the inverter (5) is configured to control the motor of the compressor in connection with a change in the current value outputted from the pressure control unit (22) according to the deviation of an internal pressure value of a receiver tank (20) for a target pressure value of the predetermined receiver tank (20).

Description

Compressor auxiliary control device and compressor auxiliary control method

The present invention relates to a compressor auxiliary control device for controlling by using an inverter and an auxiliary control method therefor. In particular, the tank pressure according to the air demand in the compressor simply operated by the load and no load operation by the conventional Y- △ start method The present invention relates to a compressor auxiliary control apparatus capable of controlling the rotation speed of the compressor motor in accordance with the change of the compressor motor to maintain a constant pressure and to control the idle speed at no load.

The present invention also relates to a method for auxiliary control of a compressor with the above described improved compressor auxiliary control device.

In general, compressors are widely used to produce compressed air, which is an element of energy that should not be interrupted for a short time, along with electricity, water, and gas, which are essential for factory automation. It is equipped with several compressors and managed in a separate room and operates 24 hours without stopping. Therefore, it consumes electric energy.

These compressors have independent functions regardless of their capacity, and the schematic configuration includes a power supply unit, a system control unit, an air compressor unit, an oil separation unit, and a cooling unit. The compressor continuously rotates two interlocking screws by a motor to produce compressed air, and automatically opens and closes an air valve installed at the inlet of the air compressor based on a user's preset low and high pressure. In operation, the process of producing compressed air by opening the intake valve is called load operation, and the state in which the valve is closed and idle is called no load operation.

The general compressor which is operated simply by the load operation and the no-load operation based on the Y- △ start method does not adequately cope with the air consumption according to the daytime, nighttime or process change, and always rotates at high speed, which causes unnecessary energy waste and mechanical loss. It is true.

To solve these problems and save energy, “inverter built-in compressor” is supplied not only to domestic products but also to foreign products, and the interest of users is increasing due to the increase in electricity rates and the government's energy policy. Most of the common industrial compressors, which do not employ inverters, are too expensive to replace energy-saving products.

In particular, 2009.07.15. In Korean Patent Registration No. 10-0908022, "Screw Compressor Control Method and Apparatus", Y-Δ start method and pressure control method are individually configured with electric and electronic circuits for control by one screw compressor to control the screw compressor. Alternatively, the multi-stage control method can be set selectively, and the air demand can be automatically or manually selected, for example, by the operation method.

However, in the patent, when the control box detects the pressure of the air supply line during load operation and the sensor detects the upper limit set value in the pressure control method, the pressure switch operates to send a stop signal to the inverter and accordingly the stop signal. The inverter idles the motor, turns off the solenoid valve to close the intake valve, and no-load operation is performed by idling the motor, releasing compressed air from the receive tank to the site, and the pressure in the air supply line during the no-load operation is performed. When the sensor detects the lower limit set value, it operates the pressure switch to restart the motor.

In the prior art, the control box is configured to force control of the compressor motor and the valves, and when the air demand exceeds 85%, in the range of 50 to 85%, or less than 50%, according to the respective air demand Since the Δ starting method, the pressure control method or the multi-step control method must be selected, the connection configuration of the wiring etc. is difficult and complicated for the manufacturers with different conventional compressors.

An object of the present invention is to solve the problems of the forced control method through the control box of the conventional compressor, the pressure control in response to the pressure sensor during the load operation and no load operation of the compressor by the conventional Y- △ start method In conjunction with the change of negative current, the operation control unit controls the compressor motor speed through the inverter to effectively suppress the high idle speed at no load and the logarithmic control function to stop and standby the motor idle at no load due to the reduction of air consumption. It is to provide a compressor auxiliary control device to perform.

Another object of the present invention is compatible with any other models as well as new compressors, and while maintaining the structure and function of the existing compressors, such as to enable efficient operation of the compressor and at the same time easy to narrow space It is to provide a compressor auxiliary control device that can be installed.

Another object of the present invention is to provide an auxiliary control method using the compressor auxiliary control apparatus.

In order to achieve the above object, the compressor auxiliary control apparatus according to the present invention, the predetermined target pressure for the receiver tank for receiving and storing to supply the compressed air generated from the compressor operated by the Y- △ start method to the place of use In the compressor auxiliary control device for controlling the motor speed of the compressor through the inverter in addition to the control box for controlling the compressor in accordance with the pressure in the receiver tank detected by the overpressure sensor,

Inverter pack control unit that selects operation conditions such as operation, stop, automatic and manual of compressor, and inputs target pressure value,

Automatically detects the load and no-load operation state of the compressor based on the signal for the current state input during operation from the compressor, prevents high idle during no-load operation, and stops the motor when the preset no-load operation continues for a predetermined time An operation control unit for performing a standby function to prevent power supply operation and separating a power power supply and an operation power supply to drive a compressor motor;

It includes a pressure control unit for outputting the current according to the deviation value by comparing and calculating the target pressure value preset by the user in the receiver tank and the pressure value output by the pressure sensor,

The inverter is configured to control the compressor motor in association with the change in the current value output from the pressure control unit according to the deviation of the internal pressure value of the receiver tank with respect to the target pressure value of the preset receiver tank.

Compressor auxiliary control device according to the present invention is provided separately from the compressor can be easily and quickly connected to the control configuration using the inverter to the existing compressor and can be applied, while maintaining the structure and function of the existing compressor, etc. In addition to providing a secondary control device that can be easily connected and used for easy installation in a confined space while also allowing safe driving.

1 is a schematic state diagram using the compressor auxiliary control apparatus according to the present invention applied to the compressor.

2 is a front view of the auxiliary control apparatus according to the present invention.

3 is a schematic longitudinal sectional view of the auxiliary control device of FIG. 2;

4 is a schematic block diagram of the configuration of the auxiliary control device of FIG.

5 is a flowchart illustrating an auxiliary control method using the compressor auxiliary control device according to the present invention.

Compressor auxiliary control apparatus according to the present invention is the inverter pack control unit 23 for selecting the operation conditions of the compressor operation, stop and automatic, manual, etc. and input the target pressure value, and the operation at the time of operation from the compressor (8) An operation control unit 12 for controlling the speed of the compressor through an inverter according to a preset signal based on an input signal for a current state, and a target pressure value and a preset pressure set by a user and detected by a receiver and outputted by a pressure sensor. And a pressure control unit 22 for comparing and calculating the pressure values.

Hereinafter, with reference to the accompanying drawings showing an embodiment of the present invention will be described in more detail the present invention.

1 to 4 will be described a compressor auxiliary control apparatus of the present invention.

The main power circuit breaker 1 for supplying external power is an inverter 5 for controlling the control of the compressor and the motor speed through the main input power terminal 2 connecting the main power supply and the input circuit breaker 3 for protecting the inverter. The inverter (5) is electrically connected to the compressor (8) via an inverter output selector (6) and an output terminal (7). The compressor 8 is operated by a normal Y-Δ starting method, and is a compressor controlled by its control box to perform no load operation and load operation.

A compressor power supply unit 9 is connected to the main input power terminal 2 to supply and drive power to the compressor 8 through the compressor operation power terminal 10. When the compressor 8 is operated, a motor operating state and a valve opening / closing signal are supplied to the driving control unit 12 through the driving signal terminal 11. For example, operation signals such as motor operation speed and valve opening and closing at no load operation or load operation are supplied to the operation control unit, and the operation control unit 12 automatically detects the load and no-load operation state of the compressor 8 input. Based on such operation state, the user controls the compressor's motor according to the input and set in advance, and performs high speed idling prevention, standby function of compressor motor, feeding operation prevention function and safety function during no load operation. Supply separate power and operating power.

The compressed air generated by the compressor is stored in the receiver tank 20 and supplied to the demand destination, and the receiver tank 20 is provided with a pressure sensor 25 so that a signal corresponding to the compressed air pressure in the receiver tank 20 is pressure controlled. The pressure controller 22 outputs a current signal to the inverter to set a target pressure, calculate a deviation by calculating a pressure value and a target pressure value detected by the receiver tank, and obtain a deviation and match each other. do.

The pressure control unit 22 receives a function of setting a target pressure and a signal of the pressure sensor 25 installed in the receiver tank 20 through the input signal terminal 21 and the pressure deviation from the target pressure and the pressure sensor. For example, the output current signal of 4mA ~ 20mA, for example, the inverter controls the compressor motor in conjunction with the change of the current.

That is, the pressure control unit 22 is a preset pressure range (95 ~ 100 of the target pressure when the compressed air pressure of the receiver tank 20 output by the pressure sensor 25 to a predetermined target value 100%) For example, when the target value (100%) is reached from the 20 mA output signal corresponding to 95% pressure, the signal between the corresponding 4 mA is output to the inverter. The inverter is connected to the current of the output signal of the pressure control unit 22 to control the motor of the compressor to operate at 30Hz, 30-50% of the maximum speed at the maximum speed at the time of the load operation at the basic speed Preset, this prevents high idle.

In addition, when the pressure of the receiver tank 20 reaches a predetermined target value, the compressor is controlled to close the compressor intake valve by the control box of its own and operate without load, and the compressor is operated at the basic speed for a predetermined time. If the pressure of the receiver tank does not fall below the target value while the operation is maintained and the time is counted and the preset time has elapsed, the compressor motor is supplied with the operating power but is controlled by the operation control unit so that the power is cut off and stopped. When the pressure of the receiver tank is lowered below the target value (100%) by the sensor by using the compressed air of the receiver tank, the operation control unit controls the inverter to restart the motor, but at this time, it operates at the basic speed. Motor life and energy saving effect by preventing power supply operation You get

The inverter pack control unit 23 bypasses the control device in case of manual operation for selecting a mode, that is, for selecting an arbitrary speed, automatic operation by pressure proportional control, and an inverter abnormality. Three operation methods such as operation by the control method by the control box are possible, and it executes the function of selecting an idle prevention function, a logarithmic control selection function, an input current and an error status display function, and the operation function is an operation signal. It is executed only by a signal corresponding to the motor current change of the compressor input through the terminal 11, and the stop function is always effective.

The inverter output selection contactor 6 and the bypass magnetic contactor 30 are connected to the output power supply terminal 7 and function to connect the inverter output and the direct-input start output, especially when an inverter fault occurs. This has the advantage of being used as an emergency circuit for operating the compressor.

In addition, the operation control unit 12 is composed of an electric signal of various functions of the pressure control unit 22 and the inverter pack control unit 23, and a conventional element that performs the operation of the inverter 5, the load of the compressor, no load It detects the change of current during operation to prevent the high speed idling and automatically restores the function when the load is operated. When the no-load operation is continued for more than the specified time due to the significant decrease of the compressed air usage when operating single or multiple compressors Control the compressor to perform a standby function to pause and restart it.

In addition, although not shown in the drawings, between the compressor operating power supply unit 9 and the operating power supply terminal 10 is provided with an air-cooled cooling apparatus by a fan for cooling the motor, the oil separator usually provided in the compressor It is preferred to be provided.

As shown in the front view of FIG. 2 and the side cross-sectional view of FIG. 3, the auxiliary control device according to the present invention includes an inverter operation control unit 12 including a monitor and a pressure control unit on a front surface of the case 40 made of a rectangular parallelepiped iron plate. 22) and the inverter pack control unit 23 is installed so that the user can easily input and set the operating conditions and the target pressure.

The interior of the case 40 is divided into a vertical support plate 41 disposed at an intermediate position. In the illustrated embodiment, the inverter 5 is mounted at the middle height position on the right side of the support plate 41 and the suction is at the bottom. Ventilation holes 42 for air inflow are provided, while exhaust vents 43 are provided at the upper portion to allow external air to be forcedly flowed by a cooling fan that is usually integrated with the inverter to smoothly dissipate heat generated from the inverter. Make sure The vent 42 is preferably provided with a filter.

Various elements including a power supply unit are disposed on the left side of the support plate 41 to be electrically connected to the inverter operation control unit 12, the pressure control unit 22, and the inverter pack control unit 23 mounted on the front surface. In addition, openings 43 are formed at upper and lower ends of the support plate 41 to generate an air flow by a fan built in the inverter, and thus, left side of the support plate 41 in the left region as well as the inverter in the right region in the drawing. It is desirable to allow the various elements described above to cool.

As a result, the auxiliary control apparatus according to the present invention can be compactly configured, can be easily installed in a narrow space, and can be moved to a required position, thereby improving convenience of use and having excellent heat dissipation characteristics.

In the method of connecting the auxiliary control device of the present invention to the existing compressor, the main power circuit breaker 1 of FIG. 1 is placed in a blocking position, and the input wire connected to the existing compressor is separated from the input terminal of the present invention. The power wiring is simply completed by connecting to the main input terminal (2) of the auxiliary control device and connecting the output power terminal (7) and the input terminal of the existing compressor with a standard wire.

In addition, the operation power supply connection of the control device of the present invention, the operation power supply to the compressor operating power supply unit 9 in the auxiliary control device of the present invention by separating the operation power supplied to the control device of the conventional compressor from the input terminal 17 By connecting to the existing compressor and the auxiliary control device of the present invention can be very easily connected to work efficiency is greatly improved.

Hereinafter, the auxiliary control method of the compressor using the auxiliary control device according to the present invention will be described with reference to the flowchart of FIG.

The operation method of the compressor using the auxiliary control device of the present invention is a mode selection of the inverter pack control unit 13, that is, a manual operation for selecting an arbitrary speed, an automatic operation by a pressure proportional control and a control device when an inverter abnormality occurs. By-passing selects three modes of operation such as operation by the control method of a conventional compressor.

Here, the operation of the normal compressor and the operation of switching to the operation method of the normal compressor by bypassing the control device when an abnormality occurs in the inverter are general matters, and thus the detailed description thereof will be omitted and the automatic operation method will be described.

Automatic operation is the most effective pressure control method for pursuing energy saving. In FIG. 1, the main power circuit breaker 1 is turned on and the circuit breaker 3 and the control device 12 are turned on to supply power. And setting the target pressure in the pressure control unit 22, selecting the automatic control mode in the inverter pack control unit 23, and setting the operation button to the ON state, thereby completing the operation preparation state (operation preparation step S1). Next, the operation button of the compressor 8 is pressed to operate (operation step S2). At this time, the inverter starts the compressor motor in a stopped state, increases the speed to the maximum speed, and performs load operation for generating compressed air in the compressor and storing it in the receiver tank (load operation step S3).

At this time, the pressure control unit 22 checks whether the pressure in the receiver tank 20 reaches a preset pressure range close to the target pressure by receiving a signal from the pressure sensor 25 and comparing it with a preset target pressure value. The inverter outputs a current signal to match the receiver tank pressure (step 4).

When the pressure of the compressed air in the receiver tank 20 is the maximum deviation from the target value in the range of 95% to 100%, for example, to the preset pressure value, 20 mA, the deviation from the target value is the lowest (0). When the 4mA signal is output to the inverter, the inverter that receives the current signal of the pressure deviation from the pressure control unit operates the compressor motor at the maximum speed of the motor up to 95% in conjunction with the current signal. In% ~ 100%, the speed of the compressor motor is decelerated, and after 100%, it is maintained at the preset basic speed, for example, the motor is set as the basic speed by 30-50% of the maximum speed (step 5).

Then, check whether the actual pressure of the receiver tank has reached the target pressure (100%) set in the compressor (step 6), and when the target pressure is reached, the compressor is controlled by its control box, closing the intake valve and performing no-load operation. (Step 7), but at this time, the inverter operates at 30 to 50% of the maximum speed for a preset time, counts the no-load operation time (step 8), and stops the motor in the standby state after a certain time has elapsed. (Step 9)

Then, the use of compressed air again confirms that the pressure in the receiver tank is reduced to be lower than the target pressure value (step 10). When the pressure is lower than the target pressure value, the compressor opens the intake valve to generate compressed air. The compressor motor continues to run at the preset default speed (returns to steps 4 and 5) and when the pressure in the receiver tank begins to fall below the preset pressure range, ie the target value and actual When the deviation from the pressure value of the receiver tank is greater than the minimum value (0), the inverter increases the motor speed to control the load operation at the maximum speed (return to step 3).

As described above, in the present invention, the pressure sensor signal and the target pressure of the receiver tank are not forcedly controlled, such as controlling the inverter to stop at the target pressure and immediately closing the intake valve in the compressor and switching to no load operation as in the prior art. The inverter controls the motor in conjunction with the current signal of the pressure control unit for the deviation from the value, and the load and no-load operation of the compressor are controlled by the control box provided in the self-preset, for example, the motor It is delayed to the operation at the basic speed of 30 to 50% of the maximum speed to prevent the motor from running at high speed, and automatically operated at the basic speed without stopping the compressor motor according to the compressed air usage of the receiver tank. This prevents motor burnout and efficiency decrease due to excessive low speed operation of the compressor (8). As in the prior art, frequent load and no-load operation switching due to the use of compressed air in the receiver tank is reduced, thereby reducing power consumption, reducing noise generated by the valve operation, and extending the life of the device.

Compressor auxiliary control method and the compressor auxiliary control apparatus according to the present invention can be used to operate the compressor more efficiently by applying to the existing compressor, and can be easily installed to provide a compressor with a separate inverter built-in Do not need to.

Claims

The pre-set target pressure for the receiver tank 20 to receive and store the compressed air generated from the compressor operated by the Y- △ starting method and the pressure in the receiver tank detected by the pressure sensor 25. In the compressor auxiliary control apparatus for controlling the motor speed of the compressor through an inverter in addition to the control box for controlling the compressor according to,

Inverter pack control unit 23 for selecting operation conditions such as operation, stop and automatic, manual operation of the compressor and inputting a target pressure value,

When the load of the compressor and the no-load operation state is automatically detected based on the signal for the current state input from the compressor 8 during operation, and the high idle operation is prevented during the no-load operation, and when the preset no-load operation continues for a predetermined time An operation control unit 12 which performs a standby function to stop the motor, a material supply prevention function, and separates a power power supply and an operation power supply for driving the motor of the compressor; and

Comprising a pressure control unit 22 for detecting the target pressure value preset by the user and the pressure value output from the pressure sensor by the receiver tank and outputs the current according to the deviation value to the inverter,

The inverter 5 operates the compressor motor in association with the change of the current value output from the pressure controller 22 according to the deviation of the internal pressure value of the receiver tank 20 with respect to the target pressure value of the receiver tank 20. Compressor auxiliary control device characterized in that the control.
The inverter operation control unit 12 having a monitor disposed on the front surface of the case 40 made of a rectangular parallelepiped iron plate, and the pressure control unit 22 and the inverter pack control unit 23 include the case ( Supported by one side of the vertical support plate 41 disposed in the inner intermediate position of the 40, the inverter 5 is mounted on the other side of the support plate 41 spaced from the bottom of the case, by a cooling fan provided in the inverter Compressor auxiliary control device, characterized in that the bottom of the case is provided with a vent for inlet air inlet 42 for forced flow of the outside air to the heat dissipation, while the exhaust vent 43 for the upper portion of the case.
The pressure controller 22 compares the target pressure value with the pressure value of the receiver tank 20 through an inverter so that the deviation value becomes zero in a preset pressure range. Outputs a current value of 4 ~ 20mA, the inverter 5 in conjunction with the current value to maintain the compressor motor at the basic speed of 30 to 50% of the maximum speed, and after reaching the target pressure value to the compressor Compressor auxiliary control device characterized in that the no-load operation by the control box provided by itself.
In the compressor control method of controlling the compressor motor by the inverter in the pressure control method according to the preset compressed air demand and the compressed air pressure detected by the pressure sensor in the receiver tank, the operating conditions of the compressor such as operation, stop, automatic, manual, etc. Inverter pack control unit 23 for selecting and inputting the target pressure value, and controlling the speed of the compressor through the inverter in accordance with a preset setting based on a signal for the current state input during operation from the compressor (8) Auxiliary operation of the compressor using the auxiliary control gear device including an operation control unit 12 and a pressure control unit 22 for comparing and calculating the target pressure value preset by the user and the pressure value detected by the receiver tank and output by the pressure sensor. In the method, the main power circuit breaker 1 is turned on and the inverter circuit breaker 3 and the circuit breaker of the control device 12 are turned on to turn on the power. And setting the target pressure in the pressure control unit 22, selecting the automatic control mode in the inverter pack control unit 23, and setting the driving button to the step of turning on the operation button (S1),

Operation step (S2) to operate by pressing the operation button of the compressor (8),

Inverter starts the compressor motor in the stopped state to increase the speed up to the maximum speed to perform a load operation to generate compressed air in the compressor to store in the receiver tank (S3),

The pressure controller 22 checks whether the pressure in the receiver tank 20 reaches a preset pressure range close to the target pressure by receiving a signal from the pressure sensor 25 and comparing it with a preset target pressure value. Outputting a current signal to the inverter to match the tank pressure (S4),

When the pressure of the receiver tank 20 reaches a preset pressure range close to the target pressure in step S4, the inverter makes the compressor motor the preset speed lower than the maximum speed as the basic speed in response to the current signal. Holding step (S5),

Then check whether the pressure of the receiver tank has reached the target pressure (100%) set in the compressor (S6),

When the pressure of the receiver tank reaches the target pressure value, the compressor is controlled by its own control box to close the intake valve and perform no load operation (S7). Way.
The method as claimed in claim 4, wherein the inverter operates at a speed of 30 to 50% of the maximum speed by the inverter for a preset time in step S7, and counts a no load operation time (S8).

When the predetermined time elapses in the step (S8) to stop the motor in a standby state (S9),

And checking whether the pressure in the receiver tank decreases again due to the use of compressed air to be lower than the target pressure value (S10).

When the pressure is lower than the target pressure value in the step S10, the compressor opens the intake valve to generate compressed air, and the compressor motor is continuously operated at the preset basic speed (return to S4). Compressor auxiliary control method using a compressor auxiliary control device characterized in that the S9) is maintained.