JPH02125998A - Device for controlling operation and inspecting for screw compressor - Google Patents

Abstract

PURPOSE:To easily collect inspecting data by storing the operating state of a compressor in an external storage element capable of extracting every fixed time in a device for controlling the compressor so as to maintain the discharge pressure of the compressor within a set range and protecting the compressor in accordance with a discharge temperature. CONSTITUTION:In an oil cooled type screw compressor 1, compressed air is discharged to an oil separator 3 together with lubricating oil where the oil removed compressed air is supplied to a compressed air receiver through an after cooler 5, and the separated oil is resupplied to the compressor 1 through an oil cooler 4. In this case, at the upstream side and the downstream side of the oil separator 3, a temperature detector 10 and a pressure detector 9 are provided. Data obtained therefrom is transmitted to a reader/writer 7 attached to a control panel 6 and stored in an IC card (external storage element) 8 every constant time. A set value concerning the operation of the compressor 1 which is previously stored in the IC card 8 is read to control an operation.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a device for controlling screw compressors and inspecting operating conditions, and in particular, for setting and changing set values for compressor operation, and for daily inspection. The present invention relates to a device suitable for saving labor and simplifying the checking of the usage status of a compressor.

[Prior Art] In the conventional technology, for example, a temperature switch is used to detect the temperature of a compressor, and when a certain set value is reached, the temperature switch is activated to stop the compressor. In addition, human beings visually check the display using a thermometer and record it on recording paper for daily inspection. Related to this, JP-A-54-
Publication No. 176109 is mentioned.

[Problems to be Solved by the Invention] In the conventional technology, daily inspections are performed by a human visually checking the display attached to the screw compressor and recording it on a recording paper.
This requires humans to go to the location where the compressor is installed and inspect it at regular intervals. In addition, compressor operation and abnormality checks are performed using the control equipment and abnormality detection equipment attached to the compressor, based on set values and tolerance values determined for each compressor. Alternatively, these devices had to be changed every time the set values or tolerance values were changed.

The purpose of the present invention is to save labor in daily inspection of screw compressors and to share control equipment and abnormality detection equipment.

[Means for Solving the Problems] In order to achieve the above object, the present invention provides a sensor that detects the discharge pressure and discharge temperature of a screw compressor, and sets the discharge pressure detected by the sensor to an upper limit of the set value. and a control device that controls the compressor to maintain the compressor between the specified value and the lower limit value, and performs a protective operation for the compressor when the detected discharge temperature exceeds the allowable value, and the upper limit value of the set value of the discharge pressure. An external storage element such as an IC card or a magnetic card in which the lower limit value and the allowable discharge temperature value are recorded in advance, and the external storage element can be inserted and removed, and the above-mentioned prerecorded values can be stored from the inserted external storage element. a read/write device that reads the upper and lower limits of the set value of the discharge pressure and the allowable value of the discharge temperature into the storage section of the control device, and writes the detected discharge pressure and discharge temperature to the external storage element; The present invention provides a device for controlling and inspecting the operation of a screw compressor consisting of the following.

[Function] When the external storage element is set in the insertion port of the read/write device, the above set values and tolerance values are read by the control device. On the other hand, data detected by the sensor attached to the compressor side is stored from the read/write device via this control device in the already set external storage element at regular intervals.

Additionally, this control device constantly compares the detected discharge pressure of the compressor with the aforementioned set value, and controls the compressor so that the detected discharge pressure data is between the upper and lower limits of this set value. control, and when the detected discharge temperature exceeds the temperature tolerance, a compressor protection operation (for example, compressor shutdown) is performed.

After the compressor has finished operating, daily inspections of the compressor can be carried out by taking out the aforementioned external storage elements from the read/write device, reading and organizing them with another data aggregation processing device, and printing them out in a fixed manner. can.

[Example] An example of the present invention will be described below with reference to FIG. This embodiment is an example in which the present invention is applied to an oil-cooled screw compressor for producing compressed air. Oil-cooled screw compressor 1
is rotated by the mold 2 via the belt 2'. During the compression process of the air compressed by the compressor 1,
It is discharged to the oil separator 3 together with the lubricating oil supplied for lubrication, sealing, and cooling. The compressed air from which oil has been removed by the oil separator 3 is cooled by an aftercooler 5, then discharged and sent to a compressed air demand device. On the other hand, the separated oil accumulates in an oil tank section at the bottom of the oil separator 3, is cooled by an oil cooler 4, and is supplied to the compressor 1 again.

Operation, stopping, abnormality detection, etc. of the compressor 1 are performed by a control panel 6.

The air compressed by compressor 1 becomes high temperature and contains 11m of oil.
A temperature detection device 10 is installed in the middle of the discharge to detect the temperature and check for abnormalities. This detection device 10 is connected to the control panel 6, converts the temperature into an electrical signal, and sends it to the control panel 6. Similarly, a pressure detection device 9 provided at the outlet of the oil separator 3 is also connected to the control panel 6, and the pressure at that location is converted into an electric signal and sent to the control panel 6.

The data obtained from these two detection devices 9 and 10 is sent to a read/write device 7 connected to the control panel 6, and is recorded at regular intervals on an IC card 8, which is an external storage element set there. be done. Further, the IC card 8 stores in advance setting values regarding the operation of the compressor 1.
This is read out and the operation is controlled. In addition, in order to determine abnormalities during operation, an IC card 8 set in the read/write device 7 stores in advance a permissible temperature value (for example, 105° C.) at the location where the temperature detector 10 is installed. is read from the IC card 8 during operation, and when the temperature detected by the detector 10 exceeds this allowable value, the compressor is stopped to protect the machine.

The pressure detected by the pressure detection device 9 is 8.5 kgf when the operating load is 30% of the full load for capacity control.
/ al (g), the compressor 1 is stopped, and when the pressure decreases to 7 kgf/cd (g), the compressor 1 is restarted. This information is stored in the IC card 8 and read from the IC card 8 while driving.

After the work of the compressed air demand equipment is finished and the compressor is stopped, the IC card 8 is removed and the recorded data in the IC card is read by another tabulation device such as a personal computer, and the data recorded in the IC card is read. Have the driver check the situation and print it out in a driving log format. The personal computer is capable of calculating the average amount of air used per day, and can predict future compressed air usage by looking at changes in compressed air usage over a period of one month, three months, etc. It has become.

A control block diagram of the above embodiment is shown in FIG.

An outline of the operation will be described below. ■First, turn on the main power. ■Next, insert the IC card 8 into the card reading/writing device 7. (2) Load the pressure setting values (upper limit value, lower limit value) and temperature tolerance value stored in advance into this IC card, and set (store) these values in the control device 6. Here, the upper and lower limits of the pressure setting value are the upper limit value for capacity control PMA.
temperature and lower limit value PMIN, and the temperature tolerance value is the tolerance temperature TMAX for compressor abnormality detection.
Engineering=8.5kgf/a#, Pii+x=7. Okgf
/a#, TMA = 105°C. Next, turn on the operation switch on the control panel of the control device, turn on the mode 2, and operate the compressor 1. ■The compressor discharge pressure detected by the pressure detector 9 fluctuates depending on the usage status of compressed air, and when this rises to the PMA level, the moder 2 turns OF.
F, and the compressor stops. ■On the contrary, when the compressor discharge pressure decreases to PMIN, motor 2 is turned on again.
The compressor will restart. Normally, the compressor is controlled so that the discharge pressure is always within the range between PMA and PMIN by repeating steps (1) and (2) above.

When the discharge air temperature detected by the temperature detector 10 rises to TMA during compressor operation, mode 2 is turned off to protect the compressor, the compressor is stopped, and a failure is displayed. After investigating the cause of this failure and taking measures, turn on the reset.
Then press the operation switch again to resume operation.

The detected discharge pressure and discharge air temperature during operation are recorded on the IC card 8 together with the operation time at regular intervals.

At the end of the day, the operator presses the stop switch on the control panel to stop the moder and compressor, and then removes the IC card 8 from the read/write device 7. The recorded data in the extracted IC card is processed by a personal computer or the like as described above.

According to this embodiment, it is possible to apply it to other compressors by replacing the IC card 8 with another IC card 8 - - , that is, by changing the stored data.

Furthermore, when changing the allowable values and set values for the same compressor, there is no need to remove and replace parts such as pressure switches and temperature switches as in the past, and it is only necessary to replace the IC card 8. Changes can be made easily. Furthermore, there is no need for humans to check the operating status at regular intervals at the location where the compressor is installed, and the operating status is automatically stored in the IC card, saving the administrator's time and effort. Furthermore, by processing this data on a personal computer, it is possible to predict the amount of compressed air that will be used in the future, making it possible to plan future equipment.6 Also, when using multiple compressors, each compressor By collecting only the IC cards for each machine and processing them on a personal computer, it is possible to easily understand the operating logs and usage status of a large number of compressors.
Labor saving can be achieved.

It is also possible to use a magnetic card, a magnetic disk (floppy disk), a magnetic tape, or the like instead of an IC card as the external storage element.

[Effects of the Invention] According to the present invention, the operating status of the compressor is recorded in a removable external storage element at regular intervals, so there is no need for people to go to the location where the compressor is installed, and data There is no need to manually write records, and inspection data can be collected, resulting in labor savings.

In addition, by changing the setting values and tolerance values that are recorded in advance in the external storage element, it is possible to apply them to different compressors, set values,
Allowable values can be easily changed, and the control device can have the same configuration and function for all machines, which has the effect of promoting common use.

[Brief explanation of the drawing]

FIG. 1 is an overall schematic diagram illustrating in detail the present invention applied to an oil-fed screw compressor, and FIG. 2 is a control block diagram of the same embodiment. 1...Screw compressor, 2...Modle, 3
...Oil separator, 4...Oil cooler,
5... Aftercooler, 6... Compressor control device 7... Reading/writing device, 8... IC card, 9... Pressure detection device, 10... Temperature detection device.

Claims (1)

[Claims] 1. A sensor that detects the discharge pressure and discharge temperature of the screw compressor, and controls the compressor so as to maintain the discharge pressure detected by the sensor between the upper and lower limits of the set value, and detects the discharge pressure and temperature of the screw compressor. a control device that performs a protective operation for the compressor when the discharge temperature exceeds an allowable value; and an IC card in which the upper and lower limits of the set value of the discharge pressure and the allowable value of the discharge temperature are recorded in advance; It is possible to insert and remove an external storage element such as a magnetic card, and from the inserted external storage element, the upper and lower limit values of the pre-recorded discharge pressure setting value and the discharge temperature can be stored. A device for controlling and inspecting the operation of a screw compressor, comprising: a read/write device that reads allowable values into a storage section of the control device and writes the detected discharge pressure and discharge temperature to the external storage element.