JPS6099947A - Operation control of air conditioner - Google Patents

Abstract

PURPOSE:To provide the air conditioner equipped with a frequency converter, capable of permitting the capacity control of a plurality of compressors in conjunction with each other, by a method wherein a plurality of compressors are employed in order to cope with stepwise and wide load fluctuation efficiently. CONSTITUTION:In case a part of a plurality of coolers 4 becomes unnecessary, control of capacity of the compressor 1 becomes necessary in accordance with reduced thermal load. The capacity control is effected by controlling the number of operating sets among a plurality of compressors 1 or the individual minimum capacity operation of the compressor 1 is effected by reducing the frequency by a frequency converter 7. On the contrary, in case the thermal load is increased, it is necessary to increase the number of operating coolers 4. In order to cope therewith, the frequency is increased to (n) times by the frequency converter 7 and either one of the compressors 1 is employed alternately in accordance with the condition of the side of load to achieve the load side cooling capacity of 2Xn times substantially.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to an operation control system for an air conditioner that controls the capacity of a compressor using a frequency converter.

[Prior art]

Conventionally, a device of this type is shown in FIG.

In the figure, ill is a compressor, (2) is a condenser that radiates heat from the high-temperature, high-pressure refrigerant gas compressed by compressor ill and turns it into a saturated liquid, (3) is a throttling expansion device, and (4) is a throttling expansion device. +
A cooler in which a low-temperature liquid refrigerant with a pressure lower than 31 K flows and absorbs heat from the surrounding area (61 lamp bypass pulp, when the heat load applied to the cooler <n is small and the capacity of the compressor + I + is relatively large) This is for controlling the capacity of the entire refrigeration cycle by bypassing the heat-controlled compressed 6 gas.

How the conventional system works When controlling the capacity of the refrigeration cycle as explained above, the energy is Not only is there a waste of consumption, but the width that can be controlled is limited to a relatively small range.

[Summary of the invention]

This invention was made in order to eliminate the drawbacks of the above-mentioned ones, and it uses all of the compressors to efficiently respond to wide stepwise load fluctuations, and by interlocking these compressors. The object of the present invention is to provide an air conditioner equipped with a frequency converter that enables capacity control.

[Embodiments of the invention]

An embodiment of the present invention will be described below with reference to FIG.

In FIG. 2, 11] are compressors connected in parallel with each other, (
2) is a condenser, (3) is a throttle expansion device, (4) is a number of coolers connected in parallel with each other, (6) is a driving electric motor for compressor (1), and (7) is an electric motor +610 'A frequency converter used as a source. The capacity is n times the rated operation of one compressor (1) (nH usually thicker than l) fI:
This is made possible when the number of accidents increases.

According to this invention, if the operation of some of the compressors (41) becomes unnecessary, it is necessary to control the capacity of the compressor f+i by ≠2 in response to the reduced heat load. This is carried out by controlling the number of compressors 11i or by reducing the frequency of the individual minimum capacity operation of the compressor t11 using a frequency converter (7).
Conversely, when the heat load increases, it is necessary to increase the number of coolers 14), but correspondingly, the frequency of the frequency converter (7) is increased to n times to adjust to the load side situation. Accordingly, either of the compressors (1) is applied alternately to achieve substantially 2Xn times the load-side cooling capacity.

This will be further explained using FIG. To make the explanation easier to understand, two valve compressors are used as shown in Fig. 3, and the maximum rotation speed of each is 1.5 times the rated value and the minimum rotation speed is 0.5 times the rated value. Corresponding to the above, the frequency converter (7) can only change H60Hz at rated time, 90Hz at maximum rotation, and 30H2 at minimum rotation, and has a maximum capacity of 90H.
It shall be able to withstand up to the capacity of one compressor in case z. Therefore, the maximum power supply capacity should be 2.5 times the rated capacity of one compressor. However, it is possible to increase the cooling capacity up to 3 times the lamp. The cooler (41) can be connected up to 6 pieces, 3 pieces A and B.
It is divided into two zones. It is assumed that the capacity of one cooler (4) corresponds to the minimum rotation (of the rating]/2) of one compressor.

(8) is a stop valve. Now, assume that the load on zone A is especially high at the beginning of cooling. Set the frequency converter (7) to 90Hz, and connect the compressor tl on the right side in Fig. 3.
+ is operated at maximum to circulate the refrigerant sufficiently to the three cooling units (4) in the A zone. On the other hand, against the B zone,
In Fig. 3, the compressor (1) on the left side is operated and cooled with a 60Hz rated power source, and the load condition in zone B is adjusted to 1.
The stop valves (8) of two coolers (4) are closed;
The capacity of the compressor ill is balanced with the capacity of the compressor ill, which is hindered by the individual coolers (4). If the A zone is slightly cooled and the B zone is insufficiently cooled, the relationships above the power supply and frequency converter (7) are reversed. Both A and B zones were abandoned,
If the VC is long with two coolers (4), each compressor (111c rated power source - (pressure is applied).

Furthermore, if only one cooler (4) is needed for the HE zone or 1'fB zone, a 30 Hz power source is sent from the frequency converter (7) to the compressor (1) of that system. Furthermore, when a good load condition is achieved with one cooler (4) in both A zone and B zone, the frequency converter (7) is installed.
Hz power is fed into both compressors (1).

〔Effect of the invention〕

As described above, if all of the volume injection control methods are adopted in such a frequency converter (7), a frequency converter (7) with a relatively small capacity and low cost, which has a capacity 1.5 times that of one compressor, can be obtained. Since the rated capacity of one compressor is changed over and used appropriately, the cooling capacity of a power supply capacity of 2.5 times the rated capacity of one compressor can be up to 3 times. → 5 units → 4 units → 3 units → 2 units → 1 unit and coolers can be used for individual energy-saving and comfortable operation.

To simplify the explanation, we have omitted the device for sensing the load applied to the cooler and the device for switching the connection of the frequency converter (7) to each compressor (1), but these devices utilize electronic control technology. Although we have explained the specific number of compressors, the number of compressors, the number of frequency converters, and the number of heat exchangers, it is basically possible to have a wide range of numbers.

Well, I explained it in terms of cooling, but it's basically the same for heat pump heating.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram of a conventional air conditioner, FIG. 2 is an explanatory diagram showing one embodiment of the present invention, and the third diagram is an explanatory diagram showing another embodiment of the present invention. In addition, in the figures, the same reference numerals indicate the same or equivalent parts. In the figure, +1) is a compressor, (2) is a condenser, (3) is a squeezing expansion device, 14) is a cooler, (6) is a compressor electric i# machine,
(7) is a frequency converter. Agent Masuo Oiwa Figure 1 Figure 2

Claims (1)

[Claims] A plurality of compressors are provided, and the capacity of the valley compressors is controlled. An operation control method for an air conditioner, characterized in that the capacity of the air conditioner is controlled in accordance with the air conditioning load in a range from the capacity of the maximum number of compressors x n to the minimum capacity of each compressor. .