JPH066233Y2 - Control device for compressor in refrigeration system - Google Patents

Description

The present invention relates to a control device for a compressor in a refrigeration system, and more particularly to a compressor for automatically and sequentially controlling two compressors having different capacities as the load increases and decreases. Control device.

Generally, in a refrigerating apparatus provided with two compressors having different capacities, a large compressor has a capacity corresponding to the maximum load, and becomes a custom-made product and expensive.

The present invention was made with this point in mind, and a maximum load can be accommodated by a medium-sized compressor and a small compressor.
With two compressors, three-stage capacity control operation is possible,
(EN) It is possible to provide a compressor control device in a refrigeration system that has excellent followability to load fluctuations.

Therefore, the device of the present invention includes a small compressor 4 and a medium compressor 5.
And a second low-pressure pressure switch 2 having a normally-closed contact 6a and a switching normally-open contact 6b in a current path to the compact compressor 4.
And a normally open first low-pressure pressure switch 1 connected in series to a normally-closed contact 6a of the switch, and a medium-sized compressor 5 connected to the switching normally-open contact 6b of the second low-pressure pressure switch. In addition, a normally open third low pressure switch is provided in a side passage that crosses the second low pressure switch and the first low pressure switch, and when the load is small, the first low pressure switch is made and the small compressor 4 When the load is medium, only the medium-sized compressor 5 is operated by switching the contacts of the second low-pressure pressure switch, and when the load is large, the third low-pressure pressure switch is also made, so The small compressor 4 is also designed to be operated.

Next, an embodiment of the present invention will be described with reference to the drawings.

In the figure, reference numeral 1 denotes a first low pressure switch, which is connected to the compact compressor 4.

The second low pressure switch 2 has a normally closed contact 6a and a switching normally open contact 6b, and the normally closed contact is connected to the first low pressure switch.

Reference numeral 3 denotes a normally open third low-pressure pressure switch, which is provided in a side passage extending over the second low-pressure pressure switch 2 and the first low-pressure pressure switch.

These first, second, and third low-pressure pressure switches 1, 2,
The cut-in and cut-out set pressure ranges in 3 are the lowest in the first low-pressure pressure switch 1, and then in the second
The low pressure switch 2 and the third low pressure switch 3 are the highest.

Therefore, when the load becomes small, the first low pressure switch 1 is closed and only the small compressor 4 is operated.

If the load is further increased, the first low pressure switch 1 remains made, but the second low pressure switch is switched to the contact 6 to operate only the medium-sized compressor.

When the load is further increased, the second low-pressure pressure switch 3 is left with the switching contact 6b being left unchanged.
Is closed, which causes both the small compressor 4 and the medium compressor 5 to operate.

That is, the third low pressure switch 3 is provided in the circuit for operating the small compressor 4 in a side path across the first low pressure switch 1 and the second low pressure switch 2.
The low pressure switch 3 and the second low pressure switch 2 form a circuit of maximum capacity.

The device of the present invention has the above-mentioned structure, and the compressed air is two units having different capacities, but the capacities can be carried out in three stages. Moreover, since the maximum capacity is the sum of the capacities of two compressors, it is not necessary to specially order a compressor with a large capacity, and a refrigerator with a large capacity can be provided at low cost.

In the embodiment, the case where the load fluctuation is increased has been described. However, when the load decreases, it is natural that the exercises according to the respective loads are performed in the reverse order to the load fluctuation. The followability is also very good.

[Brief description of drawings]

FIG. 1 is a circuit diagram of the present invention, and FIG. 2 is a comparative explanatory view showing comparison of cut-in and cut-out set pressure ranges of three low pressure switches. In the figure, 1 ... First low pressure switch 2 ... Second low pressure switch 3 ... Third low pressure switch 4 ... Small compressor 5 ... Medium compressor

Claims (1)

[Scope of utility model registration request] 1. A second low pressure switch 2 comprising a small compressor 4 and a medium compressor 5, and a second low pressure switch 2 having a normally closed contact 6a and a switching normally open contact 6b in an energizing path to the small compressor 4. A normally-open first low-pressure pressure switch 1 connected in series to a normally-closed contact 6a of the switch is provided, and a medium-sized compressor 5 is connected to the switching normally-open contact 6b of the second low-pressure pressure switch. A normally open third low pressure switch is provided in a side passage that crosses the second low pressure switch and the first low pressure switch, and when the load is small, the first low pressure switch is made and only the small compressor 4 operates. However, when the load is medium, only the medium-sized compressor 5 is operated by switching the contact point of the second low-pressure pressure switch, and when the load is large, the third low-pressure pressure switch is also made, and in addition to the medium-sized compressor, a compact compression is performed. Machine 4 is also set to operate Control device of a compressor in the device.