JPS6029553A - Refrigerator - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a refrigeration system which is equipped with several refrigerant compressors and in which part of the refrigerant compressors is controlled in rotational speed.

Conventionally, there have been devices of this type as shown in FIGS. 1 and 2. In FIG. 1, 1 is a power source, 2 is a rotational speed control device, 3Fi is a refrigerant compressor which is driven by the rotational speed control device 2, and 4 is a sensor for detecting a refrigeration load. Figure 2 shows the refrigeration load Lr and refrigeration capacity C controlled by this type of device.
It is a refrigerating capacity characteristic diagram showing the relationship between r.

The operation will be briefly explained. The refrigerant compressor 3 is.

A power source 1&r supplied via the rotational speed control device 2 is used for mechanical driving. Sensor 4 that changes according to fluctuations in refrigeration load
Based on the load information from the refrigerant compressor 3, the rotation speed of the refrigerant compressor 3 is controlled by the rotation speed control device 2, so that the relationship between the refrigeration load and the cooling capacity is approximately proportional as shown in FIG. Explode. Therefore, depending on the refrigeration capacity of the refrigeration system, the number of models of the refrigeration compressor 3 is increased, so in the refrigeration system shown in FIG. The rotational speed is controlled by the capacity that satisfies the required power.

Since conventional refrigeration equipment is configured as described above, it is necessary to match the capacity of the rotation speed control device to the capacity of the refrigerant compressor, and as a result, the refrigeration capacity can be adjusted arbitrarily by controlling the rotation speed of the refrigerant compressor. It is essential to have a rotation speed control device with a predetermined capacity to control the temperature, and in that case, it is necessary to prepare the rotation speed control device model in advance depending on the type of refrigeration pressure flii machine, which makes it very expensive. There was a drawback.

This invention was made in order to eliminate the drawbacks of the conventional method described above.
Some of these refrigerant compressors are driven via the rotation speed control device, and other refrigerant compression vIAs are driven directly by the power supply without the rotation speed control device, and the rotation speed control device is miniaturized. The aim is to provide an inexpensive refrigeration system as a whole.

An embodiment of the present invention will be described below with reference to FIGS. 3 and 4. In Fig. 3, 1 is a power source, 2 is a rotation speed control device with a capacity approximately equivalent to the power required for the entire refrigeration system,
3a r S b is a refrigerant compressor with a capacity of about half of the total refrigeration capacity, 4ti is a sensor that detects the refrigeration load, 5Fi is a changeover switch that controls the power supply to refrigerant compressors 3a and 3b, and 6 is operated at a constant speed. It is controlled by a sensor 4b using an on/off switch of the refrigerant compressor 3a or 3b. Reference numeral 7 denotes a refrigeration load judger, which controls the rotational speed control device 2 and the important switch 6 according to the refrigeration load information from the sensor 4.

FIG. 4 shows the relationship between the refrigeration load controlled by the refrigeration system shown in the embodiment of FIG. 3 and the refrigeration capacity.

The operation of this embodiment will be briefly explained. The power supplied to the power supply 1 is used to compress the refrigerant m3a and 3b through the rotation speed control device 2 and the on/off switch 6, respectively, and the sensor 4
When the refrigerating load is less than approximately 50% as shown in FIG. Refrigeration load and refrigerating capacity are proportionally controlled in #1 as shown by the solid line t□ in FIG. - At this time, the operation of the refrigerant compressor 3b is stopped as shown by the chain line t3 in FIG.

When the refrigeration load becomes more than half, that is, 50 inches or more, the refrigeration load judge 7 connects the important switch 6 and also operates the refrigerant compressor 3b at a constant rotation speed, as shown by the chain line t in FIG. At the same time, the refrigerant compressor 3a is
stop. In this case, the refrigeration load increases and the refrigerant compressor 3b
If the refrigerating capacity is insufficient, the refrigerant pressure m is added to the calculations of the sensor 4 and the judge 1 to determine whether or not the refrigerant pressure m is necessary for the operation of the machine 3a. The machine 3a is again operated by the rotational speed control device 2. As a result, 2 in FIG.
As shown by the dashed dotted lines A and VC, the refrigeration load and the refrigeration capacity can be controlled almost proportionally. When the refrigeration load decreases, the refrigerant compression @3m first proportionally reduces the refrigeration capacity, and when the refrigeration load reaches about 50%, the refrigeration load judge T turns on/off switch 6. The refrigerant compression s3b is cut off and the refrigerant compression s3b is stopped, and the rotational speed control device 2&j refrigerant pressure m machine 3a is instructed to speed up to the maximum speed.

When the refrigeration load is reduced to less than half, the refrigerant compressor 3a starts deceleration operation again.

The refrigerant compression MSb is indicated by the dashed line t in FIG.

As shown in , since it operates only when the refrigeration load is half or more, there is a difference in life between the refrigerant compressor 3a and the refrigerant compressor 3a. This
By switching the changeover switch 5 to prevent this, it is possible to make the operating time more uniform. That is, the CIJ refrigerant pressure 1tsil13a and 3b is set to the changeover switch 5.
The rotational speed control device 2 and the on/off switch 6, which give operation instructions, are exchanged with each other.

The configuration of the refrigeration load judger 1 which performs the above-mentioned calculation instructions according to the input from the sensor 4 or the configuration of the rotation speed control device 2 is based on known technology such as a step-type temperature switch or an inverter device, respectively. Since this can be easily achieved, a detailed explanation will be omitted.

Although the above embodiment has been described with two refrigerant compressors 1113a and 3b, it is clear that the number of refrigeration compressors a may be further increased. Although the primary changeover switch 5 is shown to be manual, it may be automatically changed over using another signal.

As described above, according to the present invention, a plurality of refrigerant compressors are installed, and the rotation speed of some of them is controlled. 7? :The other parts are operated at a constant speed, and the changeover switch is used to switch between the refrigerant compressor that controls the rotation speed and the refrigerant compressor that operates at a constant speed, so the capacity of the rotation speed control device is reduced by about half. In the following, the refrigeration load and the refrigeration capacity can be controlled almost proportionally, and the operating rate of the refrigerant compressor can be made uniform.

[Brief explanation of drawings]

Fig. 1 is a conceptual configuration diagram showing a conventional refrigeration system, Fig. 2 is a refrigeration capacity characteristic diagram showing the relationship between the refrigeration capacity and refrigeration load of the conventional refrigeration system, and Fig. 3 is an embodiment of the present invention. FIG. 4 is a block diagram showing the refrigeration system, and FIG. 4 is a refrigeration capacity characteristic diagram showing the relationship between the refrigeration capacity and refrigeration load of the refrigeration system of the embodiment shown in FIG. 1... Power supply, 2... Rotation speed control device-3a + 3
b... Refrigerant pressure mtm, 4... Sensor, 5... Changeover switch, 6... On/off switch, 7... Refrigeration load judge. Note that the same reference numerals in the figures indicate the same or equivalent parts. Agent Masuo Oiwa

Claims (1)

[Claims] (1) A refrigeration system that includes a refrigerant compressor and a rotation speed control device that variably controls the rotation speed of the refrigerant compressor, and that variably controls the refrigerating capacity according to the refrigeration load capacity. a first and second refrigerant compressor, a power source for energizing each of the refrigeration compressors, a rotation speed control device provided between the power source and the first refrigerant compressor, and a rotation speed control device provided between the power source and the second refrigerant compressor; An important switch provided between the refrigerant compressors, and a refrigeration load judger controlled by this on/off switch and the rotation speed control device,
The first refrigerant compressor is equipped with a sensor that detects the size of the refrigerating load, and the rotation speed is controlled according to the refrigerating load, and the second refrigerant compressor is operated at foot speed. A refrigeration system characterized in that refrigeration capacity is proportionally adjusted according to a load range. (21) The refrigeration system is equipped with a changeover switch for connecting the first refrigerant compressor to the on/off switch and the second refrigerant compressor to the rotation speed control device. A refrigeration system according to claim 1, characterized in that: