JP2522361B2 - 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 in particular, for each indoor unit. The present invention relates to an air conditioner capable of performing heating and cooling selectively or simultaneously.

[Prior Art] Conventionally, as an air conditioner of this type, for example, Japanese Patent Application No.
There is one published in No. 63-139917. FIG. 2 is an overall configuration diagram centering on a refrigerant system of a conventional air conditioner.

In the figure, 1 is an outdoor unit of an air conditioner, 2 is a compressor that compresses a refrigerant, 3 is a four-way valve that switches the circulation direction of the refrigerant, 4 is an outdoor heat exchanger, and 5 is an outdoor heat exchanger 4 for heat exchange. It is a blower that blows the air of. 9a to 9c are the outdoor unit 1
Connected to each indoor unit, 10 is an indoor heat exchanger, 13 and
14 is a first connection pipe and a second connection pipe that connect the indoor units 9a to 9c and the outdoor unit 1, and 20 is one of the indoor heat exchangers 10 of the indoor units 9a to 9c, which is a first connection pipe 13 And a second connection pipe 14 are switchably connected to each other, a three-way switching valve 21 is each indoor unit 9a-9c
Of the indoor heat exchanger 10 is a first electric expansion valve which is a first flow rate control device, and 22 is each indoor unit 9a-9c.
Is a third connection pipe connecting the first electric expansion valve 21 side to the first connection pipe 13, and 23 is a second flow rate control device provided in the middle of the third connection pipe 22 Type expansion valve.

The conventional multi-chamber type air conditioner is configured as described above, and includes one outdoor unit 1 including the compressor 2, the four-way valve 3, the outdoor heat exchanger 4, etc., the indoor heat exchanger 10, and the three-way unit. Switching valve 20,
A first connection pipe 13 and a second connection pipe 13 are provided between the plurality of indoor units 9a to 9c, which are the first flow rate control device and include the electric expansion valve 21 and the like.
Are connected in parallel via the connection pipe 14.

Next, the operation of this air conditioner will be described with reference to the drawings.

FIG. 3 to FIG. 5 are refrigerant circulation diagrams showing the operating state of the air conditioner of FIG. 2 during the cooling and heating operation. Figure 3 is second
FIG. 4 is a refrigerant circulation diagram showing the operation operation state of only the cooling or heating of the air conditioner shown in FIG. 4, and FIG. 4 is the heating main body of the air conditioner shown in FIG. 2 (when the heating operation capacity is larger than the cooling operation capacity).
FIG. 5 is a refrigerant circulation diagram showing a driving operation state of FIG. 5, and FIG. 5 is a refrigerant circulation diagram showing a driving operation state of a cooling subject (when the cooling operation capacity is larger than the heating operation capacity) of the air conditioner of FIG.

First, the case of only the heating operation will be described with reference to FIG.

The high-temperature high-pressure refrigerant gas discharged from the compressor 2 is guided from the outdoor side to the indoor side by the second connecting pipe 14, and is discharged to each indoor unit 9a.
9c to the indoor heat exchanger 10 via the three-way switching valves 20 to be heat-exchanged (heated) and condensed and liquefied. And
The refrigerant in the liquid state passes through the first electric expansion valve 21, flows into the third connection pipe 22 and merges, and further passes through the second electric expansion valve 23, where the first refrigerant flows. Either the electric expansion valve 21 or the second electric expansion valve 23 is depressurized to a low-pressure gas-liquid two-phase state. Then, the refrigerant decompressed to a low pressure flows into the outdoor heat exchanger 4 of the outdoor unit 1 via the first connection pipe 13, where heat is exchanged to become a gas state and is again sucked into the compressor 2. A heating operation is performed by configuring such a refrigerant circulation cycle.

Similarly, the case of only the cooling operation will be described with reference to FIG.

The high-temperature high-pressure refrigerant gas discharged from the compressor 2 is heat-exchanged in the outdoor heat exchanger 4 to be condensed and liquefied, and then passes through the first connection pipe 13 and the third connection pipe 22 in this order, and the indoor units 9a. Flow into ~ 9c. Then, the refrigerant flowing into each indoor unit 9a ~ 9c,
The pressure is reduced to a low pressure by the first electric expansion valve 21, flows into the indoor heat exchanger 10, and is heat-exchanged (cooled) with the indoor air to evaporate and gasify. Then, the refrigerant in the gas state is sucked into the compressor 1 again via the three-way switching valve 20 and the second connecting pipe 14. The cooling operation is performed by forming such a refrigerant circulation cycle.

Next, the heating-based simultaneous cooling and heating operation will be described with reference to FIG.

First, the refrigerant discharged from the compressor 2 is, for example, the second
From the connection pipe 14 into the indoor units 9b, 9c in the heating operation state via the three-way switching valve 20, and the heat is exchanged (heated) in the indoor heat exchanger 10 to be condensed and liquefied. Then, the condensed and liquefied refrigerant flows into the third connection pipe 22 through the first electric expansion valve 21 in a substantially fully opened state. Further, a part of this refrigerant enters the indoor unit 9a in the cooling operation state, is decompressed by the first expansion valve 21, and then enters the indoor heat exchanger 10 to perform heat exchange (cooling) and evaporate to gas. In this state, the three-way switching valve 20 flows into the first connecting pipe 13. On the other hand, the other refrigerant liquid is depressurized to a low pressure by the second electric expansion valve 23, then flows from the third connection pipe 22 into the first connection pipe 13, and is discharged from the indoor unit 9a in the cooling operation state. It merges with the refrigerant and exchanges heat with the outdoor heat exchanger 4, where the refrigerant evaporates into a gas state and returns to the compressor 1 again. By forming such a refrigerant circulation cycle, the heating-based simultaneous cooling and heating operation is performed.

In the simultaneous cooling and heating operation mainly for cooling, the refrigerant discharged from the compressor 1 is the outdoor heat exchanger 4 as shown in FIG.
Flow into the air conditioner, and heat is exchanged by an arbitrary amount according to the amount of air blown by the blower 5, resulting in a gas-liquid two-phase high-temperature high-pressure state.
It is sent to the indoor side by 13. Then, for example, a part of this refrigerant is introduced into the indoor unit 9a in the heating operation state via the three-way switching valve 20 to the indoor heat exchanger 10, where it is heat-exchanged (heated) to be condensed and liquefied. Expansion valve 21 to third connection pipe
Inflow to 22. On the other hand, the other refrigerant passes through the fully opened second electric expansion valve 23 of the third connection pipe 22 and joins with the refrigerant from the indoor unit 9a in the heating operation state. Then, this refrigerant liquid is supplied from the third connection pipe 22 to each indoor unit in the cooling operation state.
The first electric expansion valve 21 reduces the pressure in 9b and 9c to a low pressure state and then flows into the indoor heat exchanger 10 to exchange heat (cool and evaporate. Then, the gasified refrigerant passes through the three-way switching valve 20. And then flows into the second connecting pipe 14 and returns to the compressor 2. Such a refrigerant circulation cycle is formed to perform the cooling / heating simultaneous operation mainly for cooling.

In the above description, one outdoor unit 1 and three indoor units
Although we have described the devices that connect 9a, 9b, and 9c, normally, in this type of air conditioner, two or more indoor units are connected to one outdoor unit to form a multi-room air conditioner. I am configuring.

[Problems to be Solved by the Invention] In the conventional multi-room type air conditioner as described above, a plurality of indoor units 9a, 9b, 9c connected in parallel are simultaneously or selectively operated in cooling or heating. We were able to. Therefore, it is possible to arbitrarily select not only the single operation of cooling or heating but also the simultaneous heating and cooling or simultaneous cooling and heating operation mainly of cooling.

However, it is difficult to control the rotation speed of the blower 5 in the cooling and heating simultaneous operation mainly for cooling. For example, when the outdoor wind is strong, the condensation amount of the refrigerant in the outdoor heat exchanger 4 tends to increase. It was Therefore, the rate of condensation of the refrigerant in the indoor heat exchanger 10 of the indoor unit in the heating operation state is reduced, and the heating capacity is insufficient. Therefore, in this type of air conditioner, the amount of refrigerant condensed in the outdoor heat exchanger 4 in the above operating state and the indoor heat exchanger of the indoor unit in the heating operating state.
It was necessary to be able to properly adjust the ratio of the condensed amount of the refrigerant at 10.

Therefore, the present invention can selectively or simultaneously operate the heating and cooling for each indoor unit, and even in the simultaneous cooling and heating simultaneous operation mainly for cooling, the condensation amount of the refrigerant in the indoor heat exchanger of the indoor unit in the heating operation state can be set. An object of the present invention is to provide an air conditioner that can be properly secured and can sufficiently exhibit heating capacity.

[Means for Solving the Problem] An air conditioner according to the present invention includes a compressor, a switching valve,
One outdoor unit including an outdoor heat exchanger and a plurality of indoor units each having an indoor heat exchanger are provided, and a first connecting pipe and a second connecting pipe are provided between the outdoor unit and the indoor unit. In the air conditioner connected in parallel via the heat exchanger of the plurality of indoor units, one of the heat exchangers is switchably connected to the first connection pipe and the second connection pipe, and the other of the heat exchangers is connected. Via the third connecting pipe and the flow control device to the first
And a heat exchange amount adjusting means arranged in parallel in the vicinity of the outdoor heat exchanger for adjusting the heat exchange amount of the outdoor heat exchanger.

[Operation] In the air conditioner of the present invention, one outdoor unit and a plurality of indoor units are connected in parallel via the first connection pipe and the second connection pipe, and the heat of the plurality of indoor units is increased. One of the exchangers is switchably connected to the first connection pipe and the second connection pipe, and a plurality of indoor units connected in parallel selectively perform cooling operation and heating operation at the same time. Further, by adjusting the heat exchange amount by the heat exchange amount adjusting means, the refrigerant sent from the outdoor heat exchanger in the simultaneous cooling / heating simultaneous operation mainly in the cooling state becomes the gas-liquid mixed state of the indoor unit in the heating operation state. It is sent to the indoor heat exchanger. Then, this gas refrigerant is condensed in the indoor heat exchanger of the indoor unit in the heating operation state. Furthermore, by adjusting the heat exchange amount by the heat exchange amount adjusting means, it is possible to appropriately adjust the supply amount of the gas refrigerant to the indoor heat exchanger of the indoor unit in the heating operation state in the cooling and heating simultaneous operation mainly of cooling, always, The supply of the optimum amount of gas refrigerant can be maintained.

[Examples] Examples of the present invention will be described below.

FIG. 1 is an overall configuration diagram centering on the refrigerant system of the air conditioner of the first embodiment of the present invention. In the figure, the same reference numerals and symbols as those of the conventional example are the same as or equivalent to those of the conventional example, and a duplicate description will be omitted here.

In this embodiment as well, a case where three outdoor units are connected to one outdoor unit will be described as in the conventional example, but the same applies basically when two or more indoor units are connected.

In the figure, 30 is a bypass pipe that connects the inlet and outlet of the outdoor heat exchanger 4 of the outdoor unit 1 in a short-circuited manner, and 31 is a flow control valve provided in the middle of the bypass pipe 30. The flow rate adjusting valve 31 functions as a flow rate adjusting device that adjusts the flow rate of the refrigerant flowing through the bypass pipe 30.

The air conditioner of this embodiment is configured as described above, and by adjusting the opening / closing degree of the flow rate adjusting valve 31,
The flow rates of the refrigerant flowing through the bypass pipe 30 and the refrigerant circulating through the outdoor heat exchanger 4 can be adjusted appropriately.

Next, the operation of the air conditioner of this embodiment will be described.

This multi-room type air conditioner has the same function as the conventional air conditioner in which only the cooling or heating operation and the simultaneous cooling and heating operation can be arbitrarily selected by switching the refrigerant circulation path. In the case of cooling or heating only operation and simultaneous heating and cooling operation at the same time, the flow control valve
31 is operated in the fully closed state. Therefore, each operation in this case is the same as the operation shown in the description of FIGS. 3 and 4 of the conventional example, and therefore the description thereof is omitted here.

 First, the simultaneous cooling and heating simultaneous operation of cooling will be described.

In the cooling and heating simultaneous operation mainly for cooling, as shown in FIG. 1, a part of the high-temperature and high-pressure gaseous refrigerant discharged from the compressor 2 is bypassed according to the opening degree of the flow rate adjusting valve 31.
Flows into. Then, it is directly guided to the outlet of the outdoor heat exchanger 4 via the bypass pipe 30. On the other hand, the remaining refrigerant flows through the outdoor heat exchanger 4, exchanges heat with the outside air to be condensed and liquefied, becomes a gas-liquid mixed state with the refrigerant gas from the bypass pipe 30, and passes through the first connection pipe 13 to the indoor unit 9a. ~ Sent to 9c side. Then, for example, a part of this refrigerant is introduced into the indoor unit 9a in the heating operation state via the three-way switching valve 20 to the indoor heat exchanger 10, where it is heat-exchanged (heated) to be condensed and liquefied. It is made to flow from the expansion valve 21 into the third connecting pipe 22. on the other hand,
The other refrigerant liquid is the second electric expansion valve 23 of the third connecting pipe 22.
(Fully open state) and joins the refrigerant from the indoor unit 9a in the heating operation state. And this refrigerant liquid is the third connection pipe
The indoor heat exchanger 10 after depressurizing from 22 to each indoor unit 9b, 9c in the cooling operation state by the first electric expansion valve 21 to the low pressure state
Flow into and heat is exchanged (cooling) to evaporate. Then, the refrigerant that has become a gas passes through the three-way switching valve 20 and is connected to the second connecting pipe.
It flows into 14, and returns to the compressor 2 again. By forming such a refrigerant circulation cycle, cooling and heating simultaneous operation mainly for cooling is performed.

In the above refrigerant circulation cycle, the bypass pipe 30
The flow rate of the refrigerant gas passing through is controlled by the opening degree of the flow rate adjusting valve 31. Therefore, a predetermined amount of gas refrigerant is sent to the indoor heat exchanger 10 of the indoor unit 9a in the heating operation state. For example, when the heating capacity required by the indoor unit 9a is large, the opening degree of the flow rate adjusting valve 31 is decreased, while when the heating capacity required by the indoor unit 9a is small, the opening degree of the flow rate adjusting valve 31 is increased. By doing so, the proportion of the gas refrigerant sent to the indoor heat exchanger 10 of the indoor unit 9a in the heating operation state can be adjusted appropriately.

As described above, in the air conditioner of this embodiment, the plurality of indoor units 9a to 9c connected in parallel can selectively perform the cooling operation and the heating operation at the same time. Therefore,
The range of use is expanded.

In addition, by connecting between the inlet and outlet of the outdoor heat exchanger 4 of the outdoor unit 1 by the bypass pipe 30 having the flow rate adjusting valve 31, the high temperature refrigerant gas discharged from the compressor 2 in the cooling and heating simultaneous operation mainly for cooling. Is partly guided to the outlet of the outdoor heat exchanger 4 via the bypass pipe 30, passes through the outdoor heat exchanger 4, and is condensed into the refrigerant liquid and gas-liquid mixture, and is in the heating operation state. It is sent to the indoor heat exchanger 10 of the indoor unit 9a. And this gas refrigerant is the indoor unit in the heating operation state.
It condenses in the indoor heat exchanger 10 of 9a. Therefore, the amount of refrigerant condensed in the indoor heat exchanger 10 of the indoor unit 9a in the heating operation state can be set to a certain amount or more, so that the heating capacity is sufficiently exhibited and the operation efficiency is improved.

Further, by adjusting the amount of the refrigerant passing through the bypass pipe 30 with the flow rate adjusting valve 31, the indoor heat exchanger 10 of the indoor unit 9a in the heating operation state in the cooling and heating simultaneous operation mainly of cooling.
The amount of gas refrigerant sent to can be adjusted appropriately. Therefore, the supply of the optimum amount of gas refrigerant to the indoor heat exchanger 10 of the indoor unit 9a in the heating operation state can always be maintained, so that stable heating operation can be maintained.

The size of the heating capacity required for the indoor unit 9a is determined by the difference between the set temperature and the intake air temperature, for example, but other methods are also possible. Therefore, if the information obtained by these various methods is used as a signal for adjusting the opening degree of the flow rate adjusting valve 31, the indoor heat exchanger 10 of the indoor unit in the heating operation state in the cooling and heating simultaneous operation mainly of cooling is It is also possible to automatically adjust the supply amount of the gas refrigerant.

By the way, in each of the above-mentioned embodiments, the device using the electric expansion valve 21 as the flow rate control device for the refrigerant of the indoor unit has been described, but the flow rate control is possible even with a temperature type automatic expansion valve or a capillary tube. Anything will do. Further, in each of the above embodiments, the three-way switching valve 20 is provided to connect the first connecting pipe 13 and the second connecting pipe 13 to each other.
Although it is switchably connected to the connection pipe 14 of FIG. 1, an on-off valve such as a solenoid valve may be provided for switchable connection. further,
Even an air conditioner having devices such as an accumulator and a receiver in the refrigerant pipe can be used as long as the basic operation of cooling and heating is the same.

[Advantages of the Invention] As described above, the air conditioner of the present invention is
The first connection pipe and the second connection between the outdoor unit of the stand and the plurality of indoor units
Indoor units connected in parallel via multiple connection pipes, and one of the heat exchangers of the plurality of indoor units is switchably connected to the first connection pipe and the second connection pipe, and the plurality of indoor units are connected in parallel. Since it is possible to selectively perform the cooling operation and the heating operation at the same time, the use range is expanded.

Further, by adjusting the heat exchange amount by the heat exchange amount adjusting means, the refrigerant sent out from the outdoor heat exchanger in the air-cooling simultaneous heating and cooling simultaneous operation becomes a gas-liquid mixed state and the indoor unit in the heating operation state. It is sent to the indoor heat exchanger. For this reason, the amount of refrigerant condensed in the indoor heat exchanger of the indoor unit in the heating operation state can be set to a certain amount or more, so that the heating capacity is sufficiently exhibited and the operation efficiency is improved.

Furthermore, by adjusting the heat exchange amount by the heat exchange amount adjusting means, it is possible to appropriately adjust the supply amount of the gas refrigerant to the indoor heat exchanger of the indoor unit in the heating operation state in the cooling and heating simultaneous operation mainly of cooling, always, Since the supply of the optimum amount of gas refrigerant can be maintained, stable heating operation can be maintained.

[Brief description of drawings]

FIG. 1 is an overall configuration diagram centering on a refrigerant system of an air conditioner that is an embodiment of the present invention, FIG. 2 is an overall configuration diagram centering on a refrigerant system of a conventional air conditioner, and FIG. Fig. 2 is a refrigerant circulation diagram showing the operation state of only the cooling or heating of the air conditioner in Fig. 2, Fig. 4 is a refrigerant circulation diagram showing the operation state of the air-conditioning device in Fig. 2 mainly including heating, and Fig. 5 is FIG. 3 is a refrigerant circulation diagram showing a cooling-mainly operating operation state of the air-conditioning apparatus of FIG. 2. In the figure, 1: outdoor unit, 2: compressor 3: four-way valve, 4: outdoor heat exchanger 5: blower, 9a-9c: indoor unit 10: indoor heat exchanger, 13: first connection pipe 14: first 2 connection pipe, 20: three-way switching valve 21: first expansion control device that is an electric expansion valve 22: third connection pipe 23: second flow control device that is an electric expansion valve 30: bypass pipe, 31: Flow control valve. In the drawings, the same reference numerals and symbols indicate the same or corresponding parts.

Claims (2)

(57) [Claims] 1. An outdoor unit comprising a compressor, a switching valve, an outdoor heat exchanger and the like, and a plurality of indoor units each having an indoor heat exchanger, wherein the outdoor unit and the indoor unit are connected to each other. In an air conditioner that is connected in parallel via a first connecting pipe and a second connecting pipe, one of the heat exchangers of the plurality of indoor units can be switched to the first connecting pipe and the second connecting pipe. And a branch part that connects the other of the heat exchangers to the first connection pipe via a third connection pipe and a flow rate control device, and is arranged in parallel in the vicinity of the outdoor heat exchanger, An air conditioner comprising: a heat exchange amount adjusting means for adjusting the heat exchange amount of the outdoor heat exchanger. 2. The air conditioner according to claim 1, wherein the heat exchange amount adjusting means connects the inlet and outlet of the outdoor heat exchanger with a bypass pipe having a flow rate adjusting valve.