JPS63259342A - Multi-room type air conditioner - Google Patents

Abstract

PURPOSE:To prevent the damage of a compressor by a method wherein the operating capacities of indoor units are detected in defrosting operation whereby the frequency of an inverter is selected from preset patterns with a controller. CONSTITUTION:The operating capacities of indoor units 7a,... are detected by an operating capacity detector 12. At the time of space heating refrigerant discharged from a compressor 1 passes through a pipe 11 from a four-way valve 2 and is allowed to release heat and condensed by the heat exchanger 8a of the unit 7a and space heating is carried out. The refrigerant is sent to an outdoor unit 6 through an electric expansion valve 9a, a pipe 10 and reduced in pressure by an expansion valve 4 and allowed to absorb heat and vaporized and then circulated to the valve 2 and an inverter compressor 1. When outdoor temp. falls, frosting takes place at an outdoor side heat exchanger 3. In defrosting operation as needed, the frequency of the compressor 1 is selected to meet the operating capacity by a controller 13 from patterns preset by the operating capacities of the indoor unit 7a...which are discovered by the detector 12. The damage of the compressor 1 can be therefore prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates specifically to defrosting of a multi-room air conditioner in which a plurality of indoor units are connected to one outdoor unit.

Conventional technology In recent years, the number of multi-room air conditioners has increased.

In particular, the compressor has become an inverter compressor, and the pressure reducing device has also adopted an electric expansion valve operated by pulsed energization, simplifying the system and pursuing greater comfort.

In particular, during defrosting, a method is used to shorten the defrosting time by increasing the frequency of the inverter compressor and increasing its capacity.

Problems to be Solved by the Invention However, with the above method, if the operating capacity of the indoor unit is large, the defrost time can be shortened without any problems, but if the operating capacity of the indoor unit is small, There is a risk of damage to the compressor due to a large amount of liquid backing into the compressor, and there is also the problem that the defrost time is not effectively shortened and the indoor heat exchanger is rapidly and excessively cooled, which increases the feeling of cold air entering the room. Ta. In view of the above-mentioned problems, the present invention provides a multi-room air conditioner that reduces the defrost time, eliminates the risk of damage to the compressor, and prevents an increase in the feeling of cold air blowing into the room.

Means for Solving the Problems In order to solve the above-mentioned problems, the present invention provides an operating capacity detection device that detects the operating capacity of an indoor unit, and an operating capacity that detects the operating capacity of the indoor unit to determine the frequency of the inverter compressor. and a control device that selects a pattern from among preset patterns.

Effects of the Invention With the above-described configuration, the frequency of the inverter compressor can be set to match the operating capacity of the indoor unit during defrosting.

EXAMPLE Hereinafter, a multi-room air conditioner according to an example of the present invention will be described 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-driven outdoor electric expansion valve with reversible characteristics, which is fully opened during cooling and performs a pressure reducing action during heating. 6 is an accumulator, which is housed in the outdoor unit 6.

In addition, the indoor units A, 7b, and 7c include indoor heat exchangers 8a, 8b, and 8a, and indoor electric expansion valves 9a, 9b, which are pulse-driven and have reversible characteristics and are fully open during heating and perform a depressurizing action during cooling. 9c is provided and connected to the outdoor unit 6 through a liquid pipe 1o and a gas pipe 11, forming a refrigeration cycle of a well-known multi-room air conditioner. 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 among preset patterns based on the operating capacity detected by this operating capacity detection device 12. .

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

During cooling operation, as shown by the solid line in the figure, the refrigerant discharged from the inverter compressor 1 radiates heat and condenses in the outdoor heat exchanger 3 from the four-way valve 2, passes through the outdoor electric expansion valve 4 and the liquid piping 10, and returns to the indoor side. Electric expansion valves 9a, 9b.

It is depressurized at 9C, endothermically evaporated and cooled by indoor heat exchangers 8a, 8b, and 8c, and circulated to gas piping 11, four-way valve 2, accumulator 5, and inverter compressor 1.

In addition, during heating operation, the refrigerant discharged from the inverter compressor 1 passes from the four-way valve 2 through the gas pipe 11, heats off and condenses in the indoor heat exchangers 8a, 8b, and 8c, as shown by the broken line in the figure, and heats the room. Indoor electric expansion valve 9a.

The liquid is sent to the outdoor unit 6 through the liquid piping 10 of 9b and 9a, is depressurized by the outdoor electric expansion valve 4, is endothermically evaporated in the outdoor heat exchanger 3, and is circulated to the four-way valve 2, accumulator 6, and inverter compressor 1.

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 set to
Based on the operating capacity detected in step 2, a frequency suitable for the operating capacity is selected from among preset patterns.

As described above, according to this embodiment, the frequency of the inverter compressor is selected to match the operating capacity of the indoor unit during defrosting, so there is no risk of damage to the compressor due to a large amount of liquid backing into the compressor. , it is possible to prevent an increase in the feeling of cold air flowing indoors due to sudden excessive cooling of the indoor heat exchanger.

Effects of the Invention As described above, the present invention includes a control device that selects the frequency of the inverter compressor from among preset patterns based on the operating capacity of the indoor unit detected by the operating capacity detection device during defrost. By setting the frequency of the inverter compressor that matches the operating capacity of the indoor unit, the defrost time is shortened, and there is no risk of damage to the compressor due to a large amount of liquid backing into the compressor. This has the effect of preventing the feeling of cold air blowing into the room due to excessive cooling.

[Brief explanation of the drawing]

The figure is a refrigeration cycle diagram of a multi-room air conditioner according to an 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)

[Claims] One outdoor unit that has an inverter compressor, an outdoor heat exchanger, etc., multiple indoor units that have an indoor heat exchanger, etc., an operating capacity detection device that detects the operating capacity of the indoor unit, and an operating capacity detection device that detects the operating capacity of the indoor unit. and a control device that selects the frequency of an inverter compressor from among preset patterns based on the operating capacity detected by the operating capacity detection device.