JP2563320B2 - Multi-room air conditioner - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a multi-room air conditioner in which a plurality of indoor units are connected to one outdoor unit, and more particularly to defrost.

2. Description of the Related Art In recent years, the number of multi-room air conditioners has increased. In particular, the compressor will be an inverter compressor, and the pressure reducing device will also adopt an electric expansion valve that operates by pulse energization, and the simplification of the system and the pursuit of comfort are progressing.

In particular, at the time of defrosting, a method has been adopted in which the frequency of the inverter compressor is increased to increase the capacity to shorten the defrosting time.

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention However, in the above method, when the operating capacity of the indoor unit is large, the defrost time can be shortened without any problem, but when the operating capacity of the indoor unit is small, the compressor is There is a problem that the compressor may be damaged by a large amount of liquid back to the room and the effect of shortening the defrost time is small and the feeling of cold air inside the room increases due to the abrupt excessive cooling of the indoor heat exchanger. In view of the above problems, the present invention provides a multi-room air conditioner that shortens the defrost time, does not suffer from compression damage, and prevents an increase in cold air feeling in the room.

Means for Solving the Problems In order to solve the above problems, the present invention provides an operating capacity detecting device for detecting the operating capacity of an indoor unit, and a frequency of an inverter compressor according to the operating capacity detected by the operating capacity detecting device. And a control device for selecting from among preset patterns.

Action The present invention can set the frequency of the inverter compressor that matches the operating capacity of the indoor unit during defrosting, by the above-mentioned configuration.

Example A multi-room air conditioner according to an example of the present invention will be described below with reference to the drawings.

In the figure, 1 is an inverter compressor, 2 is a four-way valve, 3
Is an outdoor heat exchanger, and 4 is a pulse drive type outdoor electric expansion valve having reversible characteristics, which is fully opened during cooling and performs a depressurizing action during heating. An accumulator 5 is housed in the outdoor unit 6. The indoor units 7a, 7b, 7c are also equipped with indoor side heat exchangers 8a, 8b, 8c and indoor electric expansion valves 9a, 9b, 9c that have a reversible characteristic and are pulse-driven with full opening during heating and pressure reduction during cooling. Is provided and is connected to the outdoor unit 6 by a liquid pipe 10 and a gas pipe 11 to form a refrigeration cycle of a publicly known multi-room air conditioner. Reference numeral 12 is an operating capacity detection device that detects the operating capacity of the indoor unit, and 13 is a control device that selects the frequency of the inverter compressor from a preset pattern according to the operating capacity detected by this operating capacity detection device 12. .

The operation of the multi-room air conditioner configured as above will be described below.

During the cooling operation, the refrigerant discharged from the inverter compressor 1 is radiatively condensed by the outdoor heat exchanger 3 from the four-way valve 2 as shown by the solid line in the figure, and passes through the outdoor electric expansion valve 4 and the liquid pipe 10 to the indoor side. The indoor expansion heat exchangers 8a, 8b, which are decompressed by the electric expansion valves 9a, 9b, 9c,
It is endothermicly evaporated by 8c, cooled, and circulated to the gas pipe 11, the four-way valve 2, the accumulator 5, and the inverter compressor 1.

During the heating operation, the refrigerant discharged from the inverter compressor 1 passes through the gas pipe 11 from the four-way valve 2 through the indoor heat exchangers 8a, 8b, 8c to radiate and condense to heat the room as shown by the broken line in the figure. The outdoor unit 6 through the inner electric expansion valves 9a, 9b, 9c liquid pipe 10
To the four-way valve 2, the accumulator 5, and the inverter compressor 1, after being decompressed by the outdoor electric expansion valve 4 and absorbed and evaporated by the outdoor heat exchanger 3.

When the outside air temperature decreases during heating operation, frost forms on the outdoor heat exchanger 3 and defrost operation is performed as necessary. At this time, the frequency of the inverter compressor 1 is the operating capacity detection device 12
The frequency that matches the operating capacity is selected from among the preset patterns according to the operating capacity detected in step.

As described above, according to this embodiment, since the frequency of the inverter compressor is selected according to the operating capacity of the indoor unit during defrost, the defrost time can be shortened with high efficiency, and the protective device does not operate and is stable. You can drive
There is no fear of damaging the compressor due to a large amount of liquid back to the compressor, and it is possible to prevent an increase in the feeling of cool air in the room due to abrupt excessive cooling of the indoor heat exchanger.

As described above, the present invention includes the control device that selects the frequency of the inverter compressor from the preset patterns according to the operating capacity of the indoor unit detected by the operating capacity detection device during defrosting. Since the frequency of the inverter compressor is selected according to the operating capacity of the indoor unit, the high-efficiency defrost time can be shortened, stable operation can be performed without activation of the protective device, and a large amount of compressor It is possible to prevent the possibility of damaging the compressor due to the liquid back and to prevent a feeling of cold air in the room due to abrupt excessive cooling of the indoor heat exchanger.

[Brief description of drawings]

FIG. 1 is a refrigeration cycle diagram of a multi-room air conditioner according to one embodiment of the present invention. 1 ... Inverter compressor, 3 ... Outdoor heat exchanger, 6 ...
… Outdoor unit, 7a, 7b …… Indoor unit, 12 …… Operating capacity detection device, 13 …… Control device.

Claims (1)

(57) [Claims] 1. An outdoor unit having an inverter compressor, an outdoor heat exchanger, etc., a plurality of indoor units having an indoor heat exchanger, etc., and an operating capacity detection for detecting the operating capacity of the indoor unit. A multi-room air conditioner comprising a device and a control device for selecting a frequency of an inverter compressor from a preset pattern according to the operating capacity detected by the operating capacity detection device during defrosting.