JPH02130350A - Air conditioner - Google Patents

Abstract

PURPOSE:To prevent the back flow of liquid of a compressor and obtain compact outdoor equipment by installing a two-way valve on the way of a bypass pipe which connects a discharge pipe and a suction one of said compressor and opening the two- way valve for a fixed time at the starting time of the compressor. CONSTITUTION:A liquid receiver 6, which is integrated with a compressor 1, a four-way valve 2, an indoor side heat exchanger 3, a pressure reducing device, an outdoor side heat exchanger 5, is connected with the other equipment in ring shape so that they may constitute a heat pump type refrigerating cycle. To the refrigerating cycle is installed the bypass pipe 9 which connects the discharge pipe 7 which connects the compressor 1 with the four-way valve 2, and the suction pipe which connects the four-way valve 2 and the liquid receiver 6. On the way is installed a two-way valve 10. This construction makes it possible to introduce a part of refrigerant gas discharged from the compressor 1 to the suction side of the compressor by opening the two-way valve 10 for a fixed time and relieve the back flow of the refrigerant to the compressor 1. It is, therefore, possible to maintain the reliability of the compressor 1 and inhibit the number or the capacity of the liquid receives 6 to a minimum and hence compact outdoor equipment.

Description

[Detailed description of the invention] Industrial applications The present invention relates to an air conditioner.

Conventional technology The conventional technique will be explained with reference to FIG.

FIG. 4 shows a refrigeration cycle diagram of a separate type air conditioner for commercial use. A liquid container 16, a second liquid receiver 17 (in many cases integrated with a compressor), etc. are connected in an annular manner. In particular, in commercial air conditioners that require a long piping length between the indoor unit and the outdoor unit, a large amount of refrigerant is sealed in the refrigeration cycle, so the refrigerant remains in a liquid state and is compressed during operation. A plurality of liquid receivers are provided for the purpose of preventing liquid from being sucked into the machine 11. Alternatively, there are cases where the capacity of the liquid receiver is increased (and the capacity is reduced to one), but in either case, a very large space is required and the outdoor unit becomes large.

Problems to be Solved by the Invention In view of the above-mentioned problems, the present invention aims to prevent liquid return in the compressor,
In addition, the refrigeration cycle is configured with a small liquid receiver, providing a compact outdoor unit.

Means for Solving the Problems The present invention configures a heat pump type refrigeration cycle by connecting a compressor, a four-way valve, an indoor heat exchanger, a pressure reducing device, an outdoor heat exchanger, and a liquid receiver in an annular manner. A discharge pipe connecting the compressor and the four-way valve and a suction pipe connecting the four-way valve and the liquid receiver are connected by a bypass pipe, and a two-way valve is provided in the middle of the bypass pipe, and when the compressor is started, The two-way valve is open.

According to the above-mentioned structure, when the compressor is started, the two-way valve is opened for a certain period of time to guide a part of the refrigerant gas discharged from the compressor to the suction side of the compressor, thereby supplying refrigerant to the compressor. This makes it possible to reduce liquid return, and while ensuring the reliability of the compressor, it is possible to minimize the number or capacity of liquid receivers and provide a compact outdoor unit.

EXAMPLE Hereinafter, an example of the present invention will be described with reference to FIGS. 1 to 3.

FIG. 1 shows a refrigeration cycle, including a compressor 1, a four-way valve 2, an indoor heat exchanger 3, a pressure reducing device 4, an outdoor heat exchanger 5, and a liquid receiver 6 integrated with the compressor 1. are connected in a ring to form a heat pump refrigeration cycle. and,
A bypass pipe 9 is provided that connects a discharge pipe 7 that connects the compressor 1 and the four-way valve 2, and a suction pipe 8 that connects the four-way valve 2 and the liquid receiver 6, and a two-way valve 10 is provided in the middle. .

Fig. 2 shows the first control circuit for the compressor 1 and the two-way valve 10, where 21 is a relay (Ry-C) that controls the operation of the compressor 4al, and 22 is connected in parallel with the compressor 1. connected 1
minute OFF timer, 23 is an OF that controls the two-way valve 10;
The contact points of the F timer 22 are shown.

The operation of the above configuration will be explained. When the user turns on the operation switch (not shown) of the air conditioner,
The relay (Ry-C) 21 is ONL, and the compressor 1 is started. At the same time, the OFF timer 22, ONL, and contact 23 are closed, and the two-way valve 10 is energized and the two-way valve 10 is opened.

As shown by the arrow in the figure, a portion of the high-temperature refrigerant gas compressed by the compressor 1 passes through the four-way valve 2, condenses in the outdoor heat exchanger 5, passes through the pressure reducing device 4, and is transferred to the indoor heat exchanger. Evaporate in vessel 3 (
The liquid absorbs heat), passes through the four-way valve 2 again, passes through the liquid receiver 6, and is sucked into the compressor 7. Also, a part of the refrigerant gas discharged from the pressure II machine 1 passes through the bypass pipe 9 and the two-way valve 10 to the liquid receiver 6.
flow into. When the operation of the pressure Milli passes for one minute, the OFF timer 22 is set to 0FFL, the contact point 23 is opened, the two-way valve 10 is closed, and the flow of refrigerant gas from the discharge pipe 7 to the bypass pipe is stopped.

Fig. 3 shows the change in pressure in the suction pipe 8 over time when the compression 8!1 is started, where the solid line shows the pressure change in this example, and the broken line shows the case when the two-way valve 10 is normally closed. As is clear from Figure 0 showing the pressure change of the two-way valve 10
If the two-way valve 10 is kept closed at all times, the drop in suction pressure after starting the compressor 1 is large; on the other hand, if the two-way valve 10 is opened for one minute, the drop in suction pressure immediately after starting is suppressed, and the two-way valve The pressure is maintained close to the pressure after 1 minute when No. 10 is closed.

The main cause of the liquid refrigerant returning to the compressor is that the suction pressure suddenly drops when the compressor is started, and the liquid refrigerant that has accumulated in the heat exchanger and piping is violently drawn toward the suction side. Since a large amount of liquid refrigerant flows violently into the liquid receiver, the liquid receiver overflows and is directly sucked into the compressor, causing liquid compression, resulting in damage to the compressor.

As described above, by providing a bypass pipe and a two-way valve and bypassing the discharged gas to the suction side for a certain period of time after the compressor is started, it is possible to alleviate the liquid returning to the compressor and improve the reliability of the compressor. In addition, it is possible to minimize the number or capacity of liquid receivers, and it is possible to provide a compact outdoor unit.

As another example, in an air conditioner equipped with a microcomputer, the same effect can be obtained by opening the two-way valve for a certain period of time when the compressor is started, using a timer included in the microcomputer.

Effects of the Invention As is clear from the above embodiments, the present invention configures a heat pump refrigeration cycle by connecting a compressor, a four-way valve, an indoor heat exchanger, a pressure reducing device, and a liquid receiver in an annular manner. A discharge pipe that connects the four-way valve and a suction pipe that connects the four-way valve and the liquid receiver are connected by a bypass pipe, and a two-way valve is provided in the middle of the bypass pipe, and the two-way valve is operated for a certain period of time when the compressor is started. By opening the compressor, a sudden drop in suction pressure can be suppressed, thereby alleviating severe liquid return, increasing the reliability of the compressor, and making it possible to design a design that minimizes the number or capacity of liquid receivers. This makes it possible to provide a compact outdoor unit.

[Brief explanation of drawings]

Fig. 1 is a refrigeration cycle diagram of an air conditioner showing an embodiment of the present invention, Fig. 2 is a control circuit diagram showing the operation of the compressor and two-way valve in Fig. 1, and Fig. 3 is a start-up of the same compressor. FIG. 4 is a refrigeration cycle diagram showing a conventional example. 1...Compressor, 6...Liquid receiver, 7...
...Discharge pipe, 8...Suction pipe, 9...
・Bypass pipe, 10... Two-way valve, 22...
...OFF timer. Name of agent: Patent attorney Shigetaka Awano Haka 1 person 1-1 pressure (
Muda 1, 1-1 Ukeishi 7-・ni-Miken 8゛・ν Anti-Immigration Control

Claims (1)

[Claims] A compressor, a four-way valve, an indoor heat exchanger, a pressure reducing device, an outdoor heat exchanger, and a liquid receiver are connected in a ring to form a heat pump refrigeration cycle, and a discharge pipe connects the compressor and the four-way valve;
An air conditioner in which the four-way valve and a suction pipe connecting the liquid receiver are connected by a bypass pipe, a two-way valve is provided in the middle of the bypass pipe, and the two-way valve is opened for a certain period of time when the compressor is started.