JPS60144570A - Air conditioner - 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 [Technical Field of the Invention] The present invention relates to a multi-type air conditioner comprising an outdoor unit and a plurality of indoor units.

[Technical background of the invention]

Generally, this type of air conditioner includes one equipped with a heat pump type refrigeration cycle as shown in FIG. In FIG. 3, A is an outdoor unit, and B and C are indoor units. Therefore, a variable capacity compressor (variable rotation speed) 1, a four-way valve 2, an outdoor heat exchanger 3, capillary tubes 4, 5, a pressure reducing device such as an expansion valve 6, a capillary tube for flow control 11, 21, a liquid line opening/closing valve 12° 22, indoor heat exchangers 13, 23, gas line on-off valves 14, 24, etc. are successively connected to form a heat pump type refrigeration cycle. That is, the indoor heat exchangers 13 and 23 are configured in parallel. During cooling operation, the refrigerant flows in the direction of the solid arrow shown in the figure, and during heating operation, the refrigerant flows in the direction of the broken line arrow as shown by switching the four-way valve 2.

A liquid-in/quection cycle 30 is provided between the refrigerant outlet pipe of the expansion valve 6 and the compression chamber of the compressor 1 via a capillary tube 31. This liquid injection cycle 30 injects refrigerant into the compression chamber of the compressor 1.

Further, one end of a liquid return cycle 40 is connected to the refrigerant pipe between the liquid line on-off valve 12 and the indoor heat exchanger 13, and the other end of the liquid return cycle is connected to the capillary tubes 4 and 5 via a capillary tube 41. and the expansion valve 6 . Furthermore, a liquid return cycle 50 is installed in the refrigerant pipe between the liquid line on-off valve 22 and the indoor heat exchanger 23.
One end of the liquid return cycle 50 is connected to the capillary tube 4 through a capillary tube 51, and the other end of the liquid return cycle 50 is connected to the capillary tube 4 through a capillary tube 51.
The refrigerant pipe between the expansion valve 5 and the expansion valve 6 is connected to the refrigerant pipe. These liquid return cycles 40 and 50 have the following functions.

That is, when indoor units) B and C are in heating operation, for example, when the operation of indoor unit C is stopped, the gas line on-off valve 24 and the liquid line on-off valve 22 are closed, and the indoor heat exchange is started. The discharge gas refrigerant is prohibited from flowing into the vessel 23. At this time, the discharged gas refrigerant that had already flowed into the indoor heat exchanger 23 accumulates there, and the collected discharge gas exchanges heat with the outside because the gas refrigerant is at a high temperature, and is gradually cooled. It becomes liquid. If the liquid refrigerant accumulates in the indoor heat exchanger 23, the gas balance of the refrigeration cycle will be disrupted when the indoor unit C resumes operation, and furthermore, the liquid refrigerant will return to the compressor 1, causing liquid compression. , there is a risk of causing damage to the compressor 1. Therefore, the liquid refrigerant generated in the indoor heat exchanger 23 is returned to the liquid line side by a liquid return cycle 5°.
By the way, in such an air conditioner, when the operation of the indoor unit C is stopped, the refrigerant pressure on the glass line opening/closing valve 24 side is prevented from occurring. [Problems in the background art] Because it is higher than the refrigerant pressure on the on-off valve 22 side,
When the operation of the indoor unit C is restarted in this state, the discharged gas refrigerant suddenly flows into the indoor heat exchanger 23, causing a loud refrigerant noise, which causes discomfort and distrust to the people in the room. was there.

[Purpose of the invention]

This invention was made in view of the above circumstances,
The purpose of this is to suppress refrigerant noise when the idle unit starts operating, thereby improving reliability.
Our goal is to provide superior air conditioners that make it possible to

[Summary of the invention]

This invention provides an on-off valve for controlling the inflow of refrigerant in each refrigerant pipe that branches to each indoor heat exchanger and becomes a high-pressure gas line during heating, and a volumetric pipe is provided either before or after the on-off valve. It is.

□ [Embodiment of the Invention] An embodiment of the invention will be described below with reference to the drawings. However, the same parts as in FIG. 3' are given the same reference numerals, and detailed explanation thereof will be omitted.

As shown in FIGS. 1 and 2, an indoor heat exchanger 13.
The refrigerant pipe is branched to 23 and has high pressure as a main line during heating operation, the refrigerant pipe between the pick-up on-off valve 14 and the indoor heat exchanger 13, and the refrigerant pipe between the on-off valve 24 and the indoor heat exchanger 23. A volume tube 91 is provided in each case. In this case, during the heating operation, the refrigerant is made to flow inside the volume tube 91 from top to bottom, and during the cooling operation, the refrigerant is made to flow inside the volume tube 91 from the bottom to the top.

Therefore, during heating operation, the discharged refrigerant rapidly expands within the volume tube 91 and then rapidly contracts, and as a result, it flows into the indoor heat exchanger in a state where it has lost energy.
``!: Because the volume pipe 91 acts as a muffler,
Sound generation is prevented. On the other hand, during cooling operation, if the load is low or the capacity is low, the low-pressure liquid refrigerant cannot be sufficiently evaporated in the indoor heat exchanger 13 or 23, and the liquid refrigerant is sucked into the compressor 1. Although it causes some inconvenience, according to this embodiment, the excess liquid refrigerant is removed from the volume pipe 91.
This has the effect of eliminating the above-mentioned inconveniences. In other words, during cooling operation, the volumetric tube 91 acts as an achievator. Further, during cooling operation, for example, in a low load state where only one indoor heat exchanger is operated, a large amount of liquid refrigerant accumulates in the outdoor heat exchanger 3 because the expansion valve 6 is throttled. Although there is a risk that a typical refrigerant overcharge phenomenon of liquid being packed in the compressor 1 and damage to the compressor 1 occurs, according to this embodiment, the indoor heat exchanger 13
- Since there is a volume pipe 91 acting as an accumulator behind the J or 23, the volume pipe 91 can take charge of (storage) a part of the liquid refrigerant that is about to accumulate in the outdoor heat exchanger 3, The amount of liquid refrigerant that accumulates in the outdoor heat exchanger 3 can be reduced, and the risk of damage to the compressor 1 can therefore be avoided as much as possible.

Moreover, there is an advantage that the indoor heat exchanger 3 can function sufficiently. Incidentally, an oil recovery hole 92 is formed in the lower part of the refrigerant pipe inserted into the volumetric tube 91, so that refrigerating machine oil can be recovered.

In addition, in the above embodiment, the arrangement position of the volumetric tube 91 is as follows:
If the refrigerant piping is high-pressure lined during heating operation, and if the refrigerant piping is branched to each indoor heat exchanger, the on-off valve 14
．． It doesn't matter where it is before or after 24. Also,
Although the case where there are two indoor units has been described, the same method can be applied to a case where there are more indoor units.

〔Effect of the invention〕

As described above, according to the present invention, it is possible to suppress the refrigerant noise at the time of starting the operation of the idle unit, thereby providing an excellent air conditioner that can improve reliability.

[Brief explanation of the drawing]

Fig. 1 is a block diagram of a heat pump/f type refrigeration cycle according to an embodiment of the present invention, Fig. 2 is a block diagram specifically showing the volumetric tube in Fig. 1, and Fig. 3 is a conventional heat pump/f type refrigeration cycle. It is a block diagram showing an example of a refrigeration cycle. 1... variable capacity compressor, 3... outdoor heat exchanger, 13
．． 23... Indoor heat exchanger, 12, 14, 22° 24.
...Opening/closing valve, 91...Volume pipe.

Claims (1)

[Claims] Compressor, four-way valve, outdoor heat exchanger, pressure reducing device. A heat pump refrigeration cycle consisting of a plurality of parallel indoor heat exchangers connected in sequence, and a refrigerant pipe that branches to each of the indoor heat exchangers and becomes a high-pressure gas line during heating, and each indoor heat exchanger 1. An air conditioner comprising an on-off valve that controls the inflow of refrigerant into the air conditioner, and a volumetric pipe provided either before or after the on-off valve.