JPS58167889A - Apparatus for running compressor - Google Patents

Abstract

PURPOSE:To permit energy saving running of a plurality of compressors by correcting pressure set value on the basis of blast property determined by the combination of control modes of compressor capacity number. CONSTITUTION:Detecting signals of discharge air detected by a pressure detector 7 and collected in a common main pipe 6 are supplied to the input of control panels 9a-9d, and control modes of capacity and number of a plurality of compressors 1a-1d and the combination thereof are determined so that the pressure becomes a set value to generate control signal outputs to the control panels 9a-9d of the respective compressors 1a-1d. The set value of pressure is corrected on the basis of this blast property so that the consumption of surplus power can be avoided.

Description

[Detailed description of the invention] The present invention relates to a compressor operating device.

Conventional control of the number of compressors involves arranging multiple compressors in parallel, collecting the discharged air from each compressor in a common main pipe, and detecting the pressure with a pressure detector installed in this common main pipe. ,
By sequentially starting and stopping a plurality of compressors so that this pressure reaches a set value, a control method is used to always generate discharge air according to the load. in this case,
Generally, one compressor is operated under capacity control, and the required number of compressors are operated under full load. This takes advantage of the fact that the pressure m1m operating at rated output has the highest efficiency.

However, since the discharge sides of a plurality of compressor JII machines are connected by a common main pipe, an imbalance occurs in the back pressures applied to the individual compressors due to equipment conditions such as piping resistance. Furthermore, in each mode of capacity control and number control of multiple compressors, the influence of these equipment conditions appears differently, so the air blowing characteristics of each compressor and even of the compressor during operation are not constant. do not have.

In contrast, conventionally, the capacity and number of compressors were controlled by comparing the detection signal of a pressure detector installed in a common main pipe with a fixed pressure setting value. There was an imbalance in the load applied to each compressor, consuming excess power, and pressure control was poor, resulting in large pressure fluctuations.

An object of the present invention is to provide an operating device that prevents consumption of excess power and suppresses large pressure fluctuations.

The present invention is characterized in that a plurality of compressors are arranged in parallel and the discharge pressure is controlled at a constant rate by capacity control and number control of these compressors. The pressure set value is corrected based on the air blowing characteristics determined by the combination of the control and number control modes, and control signals for capacity control and number control of multiple compressors are output based on this pressure set value. It is equipped with a driving device.

Hereinafter, one embodiment of the present invention will be described with reference to the drawings.

FIG. 1 shows an operating system for a plurality of compressors equipped with an example of the operating device of the present invention. In this embodiment, a case of compression with four units will be explained. 1a to ld are compressors, 21
~2d is the electric storage that drives each compressor 1a~1d! Machine, 3a
-3d is a suction pipe of each compressor la-1d, 4a-4d is each discharge pipe, 5a-5d is a capacity control mechanism provided in each suction pipe 3a-3d, and 6 is a common unit connecting each discharge pipe 48-4d. It is the mother pipe. 7 is a pressure detector for detecting the discharge pressure of the common main pipe 6, 8 is an operating device according to the present invention, and 9a to 9d are control panels for each of the pressure machines 1m to 1d. The basic function of the operating device 80 described above is to detect the discharge 'g! Input the air detection signal and adjust the pressure to the compressor 1a to 1d of II
The mode and combination 1 of capacity 1tlJ control and number control are determined, and the control panels 9a to 9d of each compressor 1a to 1°d are set.
Outputs a control signal to. Each of the controls 1192 to 9d performs on-loading and unloading of the capacity control mechanisms 5a to 5d or starting and stopping of the electric motors 2a to 2d based on No. 16.

The basic method of controlling the number of units determined by the operation unit 8 is to operate one unit of pressure aSS under capacity control based on the relationship between the current discharge pressure and the pressure set value (this is controlled by capacity control).
The required number of compressor +fi machines are operated at full load together with the iA machine (referred to as the iA machine). Table @1 summarizes this method'ft.

A brief explanation of each control 11]llb shown in Table 1, Group 1 is as follows. In other words, unloading the entire compressor is
All operating compressors are immediately unloaded.

Further, the compressor additional stop is to stop one of the compressors in operation. Furthermore, '# preparation machine volume control is
This is to unload and onload IEM 7. Further, the additional activation of the pressure LiA machine is to start one of the stopped compressors.

Furthermore, the compressor emergency start is to immediately start the stopped pressure +1 fl.

In the operating device 8 of the present invention described above, the pressure setting values shown in Table 1 are not fixed, and a plurality of compressors 1 m
It has a function 'fr' which performs correction based on the air blowing characteristics determined by the combination of the capacity control mode and the number control mode d.

This function will be explained with reference to FIGS. 2 and 3. FIG. 2 shows a method of correcting the pressure set value depending on the number of full-load operating machines obtained by the operating device 8 of the present invention. In FIG. 2, the horizontal axis indicates the number (mode) of full-load operating machines, and the vertical axis indicates the pressure setting value. Second
The figure shows a method in which the pressure setting value is corrected to a slightly larger value when the number of full-load operating machines is small. According to this method, when the number of full-load operating machines is small, pressure fluctuations due to heavy loads can be made relatively small.

Figure 1g3 shows a method of correcting the pressure set value by a combination of capacity control and number control performed by the apparatus of the present invention. In this example, the number of units operating at full load is 3.
The case where the number of storage machines is one will be explained. The horizontal axis indicates which combination of the compressors 1a to 1d is the full-load operating machine and the volumetric machine, and the vertical axis indicates the pressure setting value. In Fig. 3, taking into consideration the arrangement of the compressors shown in Fig. M1, the common motherboard 1t6
If the nearest compressor has a capacity of w4, a method is shown in which the pressure setting value is corrected to tf or a smaller value.

According to this method, it is possible to reduce the consumption of extra power caused by deviations in air blowing characteristics caused by differences in equipment conditions and operating conditions.

The operating device 8 of the present invention is constructed based on the type of compressor and the type gK of the volume control mechanism, and is not limited to the following system shown in FIG. The nine pressure setting value correction methods described with reference to FIGS. 2 and 3 are intended to clearly explain the function of the operating device of the present invention, and are not limited thereto.

As described above, according to the present invention, the pressure setting value can be corrected based on the air blowing characteristics determined by the combination of the capacity control mode and the number control mode of multiple compressors. This enables energy-saving operation by suppressing the consumption of excess power caused by deviations in the air blowing characteristics caused by the air flow.Also, since a constant response can always be set to load fluctuations, air can be supplied with less pressure fluctuation. It also has the effect of improving the reliability of equipment.

[Brief explanation of the drawing]

FIG. 1 is a system diagram of a compressor equipped with an example of the operating device of the present invention, and FIGS. 2 and 3 are explanatory diagrams illustrating control operations of the example of the operating device of the present invention. Ia to 1d... Compressor, 2a to 2d... Electric motor, 3
a to 3d...Suction type, 4a to 4d...Discharge pipe, 5a
~5d...Capacity control mechanism, 6...Common main pipe, 7...
・Pressure detector, 8... Operating device, 91-9d...
11511 pieces. Agent Patent Attorney Usuda Gai

Claims (1)

[Claims] In systems where multiple compressors are arranged in parallel and constant control of discharge pressure is performed by capacity control and number control of these compressors, the mode of capacity control and number control of multiple compressors is different. The pressure setting value is corrected based on the air blowing characteristics determined by the combination, and the pressure m of multiple units is adjusted based on this pressure setting value.
A compressor operating device characterized by outputting control signals for controlling the capacity of the compressor and controlling the number of compressors.