JPS62243995A - Parallel operation control device for compressor - Google Patents

Abstract

PURPOSE:To enable saving of a labor, by a method wherein the optimum control table of a total volume and a total consumption power is stored, and from a detecting temperature and a flow rate, an optimum control table under a nearmost condition is selected to produce a control signal. CONSTITUTION:Output signals from a temperature detector 10 and flow rate detectors 11A-11C, located in a common feed water line 7, and temperature detectors 9A-9B situated in suction lines 2A-2C are inputted to a microcomputer 13. An optimum control table, according to which a relation between a total flow rate and a total consumption power is optimized, is stored in the microcomputer 13, and from the output signals, an optimum control table under a nearmost condition is selected. Based on the signal, suction airflow control valves 3A-3C are controlled. This constitution enables control of saving energy.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to a parallel operation control device for compressors.

In particular, the present invention relates to a compressor parallel operation control device suitable for energy-saving operation of a plurality of turbo compressors that require steady-state pressure control, for example.

[Conventional technology]

For example, as a method for automatically controlling multiple compressors with different capacities in response to load fluctuations,
4-1921 is known.

This technology changes the operating order of multiple compressors depending on load capacity. Small-capacity compressors operate sequentially to cope with load fluctuations, but large-capacity compressors operate independently after a startup command. The system operates in such a way that it either moves to full load state or gradually stops independently after a stop command is issued.
It is operated under highly efficient full load conditions without frequent starting and stopping.

Generally, when controlling the number of turbo compressors, conventionally, in order to perform steady pressure control of the common discharge line of each compressor, a load distribution device is used to distribute the load of each compressor based on a certain correlation. is set, and during operation, the air volume is detected by an air volume variation detector installed in the common discharge pipe, and a flow rate control signal according to the load distribution is given to the suction capacity control means of each compressor to control the operation. I was supposed to do it.

[Problem that the invention seeks to solve]

In the above-mentioned conventional technology, when a plurality of turbo compressors are operated in parallel, the suction capacity of each compressor is controlled with a fixed load distribution, and the individual performance of each compressor is not considered. Therefore, it was not possible to control the operation so that the total power consumption of each compressor was minimized.

The present invention has been made to solve the problems of the prior art described above, and enables energy-saving control of the capacity of a plurality of compressors with different performances so that the power is always minimized. Its purpose is to provide a parallel operation control device for compressors.

[Means for solving problems]

In order to achieve the above object, the configuration of the compressor parallel operation control device according to the present invention includes a suction capacity control means on each suction side of a plurality of compressors having different capacities, and a common discharge side on each discharge side. In a compressor parallel operation control device that is connected to a pipeline and performs capacity control according to the load, a temperature detector is installed in each suction pipeline of each of the plurality of compressors, a flow rate detector is installed in each discharge pipeline, and the common discharge A flow rate fluctuation detector is installed in the pipeline, and a temperature detector is installed in the common water supply pipeline to the cooling section of each compressor.

Further, an optimal control table for the total capacity 9 total power consumption of each compressor under a plurality of setting conditions of the suction temperature and feed water temperature of each compressor is stored in advance, and the temperature of each suction pipe of each compressor is stored in advance. Detector.

Detection data of the temperature detector of the common water supply pipe, the flow rate detector of each discharge pipe of each compressor, and the flow rate fluctuation detector of the common discharge pipe are input, and from these data, the data is stored in advance. selecting the optimal control table under the closest conditions among the plurality of setting conditions of the optimal control table set, and checking the direction of variation in load capacity;
The compressor is provided with an arithmetic and control device that outputs a control command signal to the suction capacity control means of each of the compressors.

In addition, 1. The present invention uses a microcomputer, takes into account the performance characteristics of each compressor, and controls the operation of each compressor so that the total power consumption of each compressor is minimized, thereby achieving energy saving. It is something.

[Effect]

The microcomputer uses the performance characteristics of each compressor in advance to minimize the total power consumption of each compressor relative to the total air volume of each compressor.

The control order and load distribution of each compressor shall be stored. In other words, optimal control tables for the total air volume and total power consumption of each compressor are stored in advance in a microcomputer for several combinations of multiple conditions of suction temperature and cooling water supply temperature, which have a large effect on compressor power. Make me remember.

Then, based on the signal from the air volume fluctuation detector installed in the common discharge pipe, it is determined whether the change in air volume is an increase or decrease, and the air volume is determined from the flow rate detector installed in the discharge pipe of each compressor, and then Calculate the total air volume. In addition, the suction temperature is determined by a temperature detector installed in the suction pipe, and the supply water temperature is determined by a temperature detector installed in the cooling water supply pipe, and the suction temperature and the cooling water supply temperature stored in the microcomputer are calculated. The data closest to the combination conditions is selected, and a command signal to increase or decrease the air volume is given to the suction capacity control means of each compressor in accordance with the data from the microcomputer, using the total air volume and the signal from the air volume variation detector, to control the air volume.

〔Example〕

An embodiment of the present invention will be described below with reference to FIGS. 1 to 4.

FIG. 1 is a system diagram showing the equipment configuration of a parallel operation control device for turbo compressors according to an embodiment of the present invention.

Figure 2 is a performance curve diagram of compressors with different capacities, Figure 3 is a diagram showing an optimal control table that takes into account the performance of each compressor in Figure 2, and Figure 4 is a flowchart of control by a microcomputer. It is a diagram.

In FIG. 1, IA, IB, and IC are three turbo compressors with different capacities (hereinafter simply referred to as compressors), 2A,
2B and 2C indicate the respective suction pipes of the three compressors LA, IB, and IC.

These suction pipes 2A, 2B, 2C are provided with suction air volume control valves 3A, 3, respectively, which are associated with the suction capacity control means of each compressor.
B, 3C are provided, and these suction pipes 2A, 2B
, 2C are thermometers 9A and 9 related to temperature detectors, respectively.
B and 9C are provided.

4A, 4B, and 4C are the three compressors IA.

The respective discharge pipes 5 of IB and IC indicate a common discharge pipe that communicates these respective discharge pipes. 6A.

6B and 6C are coolers provided for each of the compressors IA, IB, and IC, and 7 is the cooler 6A.

Common water supply pipe for supplying cooling water to 6B and 6C, 8
is a common drain line for discharging water from each of the coolers.

10 is a thermometer related to a temperature detector provided in the common water supply pipe 7; IIA, IIB, and IIC are flow meters related to flow rate detectors provided in the discharge pipes 4A, 4B, and 4C of each of the compressors;
Reference numeral 12 denotes an air volume variation detector related to the flow rate variation detector provided in the common discharge pipe line 5.

13 inputs each signal indicating the operating status of each compressor.

Suction air volume control valve 3A related to suction capacity control means of each compressor
, 3B, and 3C, and is a microcomputer (hereinafter referred to as a microcomputer) related to an arithmetic control means for outputting control command signals to the microcomputer 13. The systems of input and output signals to the microcomputer 13 are indicated by dashed arrows.

Figure 2 shows the performance of compressors IA, IB, and IC with different capacities. In Figure 2, (a) shows compressor IA, (b) shows compressor IB, and (c ) The figure shows compressor I
It is a performance curve diagram of C. Each of these figures.

The suction temperature measured with thermometers 9A, 9B, and 9C is 300,
The cooling water temperature measured by the thermometer 10 is 25tZ'.

It shows the relationship between air volume Nm''/H (horizontal axis) and power KW (vertical axis).

The performance of the compressor IA shown in Fig. 2 (a) is the maximum air volume of 30
As is clear from the thick solid line in Figure 1, the efficiency at 00ONm''/H is the highest among the three units, and as is clear from the thick solid line in Figure 1, there is no decrease in efficiency during capacity control operation up to 25000Nd/H. /H or less, efficiency slightly decreases.

The performance of the compressor IB shown in Fig. 2(b) is the maximum air volume of 28
000 Nn? /H efficiency is second out of three,
Efficiency during reduced operation is 2500ONTF? /H has the highest efficiency, and 22000 Nrl/H is the same as the efficiency at the maximum air volume point, 22000 Nn? /H or less, the efficiency decrease increases.

The performance of the compressor IC shown in Fig. 2 (C) is the maximum air volume of 12
The efficiency at 000 Nm''/H was the third, and the efficiency during reduced operation also decreased significantly.

FIG. 3 shows the compressors IA and IB shown in FIG. 2.

The relationship between the IC's total air volume and total power consumption is optimized.
In other words, it is determined so that the power consumption is minimized. The microcomputer 13 stores in advance an optimum control table displaying the total air volume at this time, the operating status and control order of each compressor IA, IB, and IC. The relationship between this total air volume and the operating status of each compressor IA, IB, and IC is determined in advance for multiple conditions of suction temperature and cooling water supply temperature, that is, several types of combinations K, and is stored in the microcomputer 13. be.

Next, the control operation of the compressor parallel operation control device of this embodiment will be explained with reference to the flowchart of FIG. 4 in conjunction with FIGS. 1 and 3.

Three compressors IA are arranged as shown in Figure 1.

IB and IC have a suction temperature of 30C and a cooling water supply temperature of 25C.
Under the conditions of each compressor IA, IB, 1. Both C.

It is assumed that the system is operated at the maximum air volume (total air volume 70,000 Nrl/H).

First, the microcontroller 13 is connected to each compressor IA and IB.

Thermometers 9A installed in the suction pipes 2A, 2B, and 2C of 1C,
The detection data of the suction temperature is read from 9B and 9C, and the detection data of the supply water temperature is read from the thermometer 10 installed in the common water supply pipe 7 (step ■ in Fig. 4), and the control data stored in advance is read. Select the optimal control table that has the closest combination of suction temperature and feed water temperature (step ①) to enable control of the compressor.

Here, if the pressurized air volume in the common discharge pipe 5 decreases, it is detected by the air volume fluctuation detector 12 provided in the common discharge pipe 5, and a signal in the air volume range is given to the microcomputer 13 (step 2).

The microcomputer 13 has 11 flow meters installed in each discharge pipe 4A, 4B, and 4C of each compressor IA, IB, and IC.

11B reads the air volume data detected by IIC and calculates the total air volume (step ■), and at the same time compares it with the control data in the optimal control table shown in Fig. 3 and first sets the suction air volume control valve of compressor IB. It is controlled by outputting the air volume range signal to 3B.

Here, if the reduction signal from the air volume variation detector 12 provided in the common discharge pipe 5 stops before the total air volume reaches 6700 ONm/H, the capacity of only the compressor IB is controlled (step 2). If you wish to further reduce the amount, the signal to the suction air volume control valve 3B of the compressor IB will be changed to a total air volume of 67,000 Nm'/
At the same time as stopping at H, a signal in the air volume range is output to the suction air volume control valve 3A of the compressor IA to perform reduction control. The total air volume from 6,700 ONze/H to 62,000 Nd/H is controlled by the compressor IA (Step 2). Total air volume 6
200ON trl/H to 59000Ngo/H
The control is performed by stopping the signal to the suction air volume control valve 3A of the compressor IA at a total air volume of 62000 Nm'/H, and outputting a control signal to the suction air volume control valve 3B of the compressor IB (step 2). ).

By performing such control, three compressors IA,
The total power of IB and IC is always controlled to be the minimum (step ■).

According to this embodiment, three turbo compressors with different capacities can quickly follow and respond to rapid flow rate fluctuations in the common discharge pipe of each compressor, so that the total power consumption of each compressor can be maintained at all times. Capacity can be controlled to minimize power.

In addition, in the above-mentioned embodiment, an example was explained in which three turbo compressors with different performances are operated in parallel as shown in FIG. 2, but the present invention is not limited to this embodiment. It can be universally applied to multiple compressors with different values.

〔Effect of the invention〕

As described above, according to the present invention, it is possible to provide a compressor parallel operation control device that enables energy-saving control by controlling the capacity of a plurality of compressors with different performances so that the power is always minimized. .

[Brief explanation of drawings]

FIG. 1 is a system diagram showing the equipment configuration of a parallel operation control device for turbo compressors according to an embodiment of the present invention. Figure 2 is a performance curve diagram of compressors with different capacities, Figure 3 is a diagram showing an optimal control table that takes into account the performance of each compressor in Figure 2, and Figure 4 is a flowchart of control by a microcomputer. It is a diagram. IA, IB, IC...Compressor, 2A, 2B, 2
C... Suction pipe line, 3A, 3B, 3C... Suction air volume control valve. 4A, 4B, 4C...Discharge pipe line, 5...Common discharge pipe line, 6A, 6B, 6C...Cooler, 7...Common water supply pipe line. 9A, 9B, 90.10...Thermometer, 11A, IIB
. 11C...flow meter, 12...air volume fluctuation detector, 13
..., ￥ 2 daily air volume N-n・″ 4 hard

Claims (1)

[Claims] 1. A parallel operation control device for compressors that is equipped with a suction capacity control means on each suction side of a plurality of compressors with different capacities, connects each discharge side to a common discharge pipe, and controls the capacity according to the load. , a temperature detector is installed in each suction pipe of each of the plurality of compressors, a flow rate detector is installed in each discharge pipe, a flow rate fluctuation detector is installed in the common discharge pipe, and a common water supply pipe for the cooling section of each compressor is provided. A temperature detector is provided for each of the compressors, and an optimal control table for the total capacity and total power consumption of each of the compressors under a plurality of setting conditions of the suction temperature and feed water temperature of each of the compressors is stored in advance. each detection data of the temperature detector of each suction pipe, the temperature detector of the common water supply pipe, the flow rate detector in each discharge pipe of each of the compressors, and the flow rate fluctuation detector in the common discharge pipe. From these data, select the optimum control table that has the closest conditions among the plurality of setting conditions of the optimum control table stored in advance, check the direction of variation in load capacity, and 1. A parallel operation control device for a compressor, comprising an arithmetic control device that outputs a control command signal to a suction capacity control means of the compressor.