JPH0765824B2 - Air conditioner - Google Patents

Description

TECHNICAL FIELD The present invention relates to a multi-chamber heat pump air conditioner in which a plurality of indoor units are connected to one heat source unit, and particularly for each indoor unit. The present invention relates to an air conditioner capable of selectively performing heating / cooling, cooling in one indoor unit, and heating in the other indoor unit at the same time.

[Conventional technology]

Conventionally, a heat pump type air conditioner in which a plurality of indoor units are connected to one heat source unit by two pipes of a gas pipe and a liquid pipe and a heating / cooling operation is common, and all the indoor units are heated, Alternatively, they are all configured to perform cooling. Further, if the pressure drop of the refrigerant in the gas pipe is large, the evaporation temperature of the indoor unit rises during the cooling operation, and the condensation temperature of the indoor unit falls during the heating operation to lower the cooling capacity or the heating capacity. The pressure drop does not directly lower the cooling capacity and heating capacity. Therefore, although the diameter of the gas pipe is thick enough, the diameter of the liquid pipe should be thinner than that of the gas pipe in order to reduce the piping material, construction cost and workability. There is.

[Problems to be Solved by the Invention]

Since the conventional multi-room heat pump type air conditioner is configured as described above, all indoor units operate only for cooling or heating, so heating is performed where cooling is required, and conversely heating is performed. There was a problem that the air conditioning was done where it was needed.

Especially, when installed in a large-scale building, the load of air conditioning is remarkably different between the interior part and the perimeter part, or the general office room and the OA room such as the computer room, which is a particular problem.

The present invention has been made to solve the above problems, and a plurality of indoor units are connected to one heat source unit, and cooling and heating are selectively performed for each indoor unit, and one of the indoor units is provided. When installed in a large building so that the indoor unit can perform cooling and the other indoor unit can perform heating at the same time, the interior section and perimeter section, or the general office room, and an office automation room such as a computer room Therefore, it is an object of the present invention to obtain a multi-room heat pump type air conditioner capable of coping with each of which the air conditioning load is significantly different.

[Means for Solving the Problems]

According to the present invention, one heat source unit including a compressor, a switching valve, a heat source unit side heat exchanger, and the like, and a plurality of indoor units each having an indoor side heat exchanger are provided with first and second connection pipes. A plurality of indoor units, the first branch portion connecting one of the indoor heat exchangers of the plurality of indoor units to the first connection pipe or the second connection pipe in a switchable manner, and the plurality of units. Is connected to the other of the indoor heat exchangers of the indoor unit of
Second branch part connected to the connection pipe of No. 2, a pipe branch part branching from the second connection pipe to the pipe reaching the first branch part, the pipe branch part and the chamber A gas single phase having the same diameter as the first connecting pipe, the second connecting pipe being provided in the middle of the pipe connecting to the other of the inner heat exchangers, and a flow rate control device controlling the flow rate of the flowing refrigerant. It is configured to have a diameter necessary for passing the refrigerant in the liquid state and the mixed state of gas and liquid. [Operation] Usually, the pipe connecting the indoor side and the outdoor side is a pipe through which the refrigerant flows from the indoor side to the outdoor side during cooling (corresponding to the first connecting pipe of the present invention) from the outdoor side to the indoor side. The pipe diameter is made larger than that (corresponding to the second connecting pipe of the present invention). This is because the low-pressure gas flowing from the indoor side to the outdoor side during cooling has a large specific volume, and therefore the pipe diameter is increased to reduce the pressure loss.

In the present invention, the second connecting pipe is usually the same in diameter as the first connecting pipe having a relatively large pipe diameter. Since the second connecting pipe interposed between the heat source unit and the indoor unit has the same diameter as the first connecting pipe, the evaporation pressure of the indoor side heat exchanger of the indoor unit to be cooled in the case of heating mainly in the simultaneous heating and cooling operation. Since the pressure difference between the evaporation pressures of the heat source unit side heat exchanger and the heat source unit side heat exchanger becomes small, the evaporation pressure of the indoor side heat exchanger does not increase, so that the cooling capacity does not become insufficient. Further, since the evaporation pressure of the heat source side heat exchanger does not decrease, the heat exchanger does not freeze and the operation can be performed without decreasing the capacity.

Even in the case of mainly cooling in the cooling / heating simultaneous operation, since the pressure difference between the condensation pressure of the indoor heat exchanger of the indoor unit to be heated and the condensation pressure of the heat source side heat exchanger becomes small, the indoor heat exchanger Since the condensing pressure does not become low, there is no shortage of heating capacity. Further, since the condensing pressure of the heat exchanger on the heat source unit side does not rise, it is possible to operate without performing high cut.

[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. Also, FIGS. 2 to 4
The figure shows the operation state during the heating and cooling operation in one embodiment of FIG. 1, FIG. 2 shows the operation state diagram of only cooling or heating, and FIGS. 3 and 4 show the operation of the cooling and heating simultaneous operation. FIG. 3 is an operation state diagram showing a heating main body (when the heating operation capacity is larger than the cooling operation capacity) and FIG. 4 is a cooling main body (when the cooling operation capacity is larger than the heating operation capacity). . FIG. 5 is an overall configuration diagram centering on the refrigerant system of the air conditioner of another embodiment of the present invention.

In addition, in this embodiment, a case where three indoor units are connected to one heat source unit will be described, but the same applies to a case where two or more indoor units are connected.

In FIG. 1, (A) is a heat source device, (B), (C),
As will be described later, (D) is an indoor unit connected in parallel with each other and has the same configuration. (E) is a repeater having a first branch part, a second flow rate control device, a second branch part, a gas-liquid separation device, and a heat exchange part, as will be described later.

(1) is a compressor, (2) is a four-way valve that switches the refrigerant flow direction of the heat source unit, (3) is the heat source unit side heat exchanger, (4) is an accumulator, and the above devices (1), (2) ), (3),
(4) is connected to form the heat source unit (A). (5) is an indoor heat exchanger provided in three indoor units (B), (C), (D), and (6) is a four-way valve (2) of the heat source unit (A) and a relay unit ( E) is the first connection pipe that connects the indoor units, and when all of the indoor units are in the cooling operation, at least each indoor unit exhibits a predetermined performance and has a pipe diameter that allows the operation to continue without any trouble. is there. (6b), (6c) and (6d) are indoor heat exchangers (5) of indoor units (B), (C) and (D), respectively.
And the relay device (E) are connected to each other, and the first connection pipe on the indoor unit side corresponding to the first connection pipe (6), (7) is the heat source device (A)
Second connection pipe having the same diameter as the first connection pipe connecting the heat source unit side heat exchanger (3) and the relay unit (E), (7b), (7)
c) and (7d) are indoor units (B), (C), and (D), respectively.
Is a second connection pipe on the indoor side for connecting the indoor heat exchanger (5) and the relay device (E) via a first flow rate control device described later, and is connected to the second connection pipe (7). Corresponding. (8) is the first connection pipe (6b), (6) on the indoor unit side.
c) and (6d), and a three-way switching valve that is switchably connected to the first connection pipe (6) or the second connection pipe (7) side, and (9) to the indoor heat exchanger (5). The first is connected closely and is controlled by the superheat amount on the outlet side of the indoor heat exchanger (5) during cooling and by the subcool amount during heating.
Flow control device of the second connection pipe (7b) on the indoor unit side,
Connected to (7c) and (7d). (10) is the first on the indoor unit side
First connecting pipes (6b), (6c), (6d) and a three-way switching valve (8) switchably connected to the first connecting pipe (6) or the second connecting pipe (7) Branch of, (1
1) is the second connection pipe (7b), (7c), (7) on the indoor unit side.
d) and the second branch consisting of the second connecting pipe (7), (1
2) is a gas-liquid separation device provided in the middle of the second connecting pipe (7), and its gas layer part is the first port (8) of the three-way switching valve (8).
a), the liquid layer part of which is connected to the second branch part (11). (13) is a second flow control device which is connected between the gas-liquid separator (12) and the second branch part (11) and which can be opened and closed, and (14) is the second branch part (11). A bypass pipe connecting the first connection pipe (6) and the second connection pipe (7), (15) a third flow rate control device provided in the middle of the bypass pipe (14), (16b), (16c) and (16d) are respectively provided downstream of the third flow rate control device provided in the middle of the bypass pipe (14), and the second connection of each indoor unit side of the second branch section (11). Each heat exchange section that performs heat exchange with the pipes (7b), (7c), (7d), (1
7) is the heat exchange parts (16b), (16) of the bypass pipe (14)
c), (16d) and a first check valve provided between the first connecting pipe (6), and (18) is a heat exchange section (16b), (16c) of the bypass pipe (14). , (16d) and the second connecting pipe (7), which is a second check valve in parallel relationship with the first check valve (17). Stop valve (1
7) and (18) are both heat exchange parts (16b), (16c), (16d)
From the side to the first and second connecting pipes (6) and (7) only.

An embodiment of the present invention configured as above will be described. First, the case of only the cooling operation will be described with reference to FIG.

That is, the high-temperature high-pressure refrigerant gas discharged from the compressor (1) passes through the four-way valve (2) as indicated by the solid arrow in FIG.
After condensing and liquefying by exchanging heat in the heat source side heat exchanger (3),
The second connecting pipe (7), the gas-liquid separation device (12), and the second flow rate control device (13) are passed in this order, and further the second branch portion (1
1), second connection pipes on the indoor unit side (7b), (7c), (7
Passes through d) and flows into each indoor unit (B), (C), (D). The refrigerant flowing into each indoor unit (B), (C), (D) is controlled by the first flow rate control device (9) controlled by the superheat amount at the outlet of each indoor heat exchanger (5). The pressure in the room is reduced to a low pressure, and the indoor heat exchanger (5) exchanges heat with the room air to evaporate and gasify the room to cool the room. The refrigerant in the gas state is supplied to the indoor unit-side first connection pipes (6b), (6c), (6d), the three-way switching valve (8), the first branch portion (10), and the first Connection pipe (6), 4 of heat source machine
Compressor (1) through one-way valve (2) and accumulator (4)
It constitutes a circulation cycle that is sucked into and performs cooling operation. At this time, the first port (8a) of the three-way switching valve (8) is closed,
The second mouth (8b) and the third mouth (8c) are open.

Further, during this cycle, a part of the refrigerant that has passed through the second flow rate control device (13) enters the bypass pipe (14) and is depressurized to a low pressure by the third flow rate control device (15), and the heat exchange section ( 16
b), (16c), and (16d) perform heat exchange with the second connection pipes (7b), (7c), and (7d) on the indoor unit side of the second branch section (11), respectively. The evaporated refrigerant passes through the first check valve (17) and enters the first connecting pipe (6), where the heat source unit 4
Compressor (1) through one-way valve (2) and accumulator (4)
Inhaled into. At this time, the first connection pipe (6) is low pressure,
Since the second connecting pipe (7) has a high pressure, it necessarily flows through the first check valve (17) side. On the other hand, the heat exchange parts (16b), (16
Refrigerants that have undergone heat exchange in (c) and (16d) and are sufficiently subcooled are cooled by the second connection pipe (7) on the indoor unit side.
b), (7c), (7d) to flow into the indoor units (B), (C), (D) about to be cooled.

Next, the case of only the heating operation will be described with reference to FIG. That is, as shown by a dotted arrow in the figure, the high-temperature high-pressure refrigerant gas discharged from the compressor (1) passes through the four-way valve (2), the first connecting pipe (6), the first branch portion ( 10), the three-way switching valve (8), the indoor unit side first connection pipes (6b), (6c), (6d) in that order, and the indoor units (B),
It flows into (C) and (D), heat-exchanges with room air, condenses into liquefaction, and heats the room. Then, the refrigerant in the liquid state passes through the first flow rate control device (9) controlled by the subcool amount at the outlet of each indoor heat exchanger (5), and then the second connection pipe (on the indoor unit side) 7b), (7c), and (7d) flow into the second branch portion (11) and merge, and further pass through the second flow rate control device (13), where the first flow rate control device (9) is present. Alternatively, the pressure is reduced to a low-pressure two-phase state by either the second flow rate control device (13). Then, the refrigerant decompressed to a low pressure flows through the gas-liquid separation device (12) and the second connection pipe (7) into the heat source unit side heat exchanger (3) of the heat source unit (A) to exchange heat. The refrigerant in the vaporized gas state is
Compressor (1) through one-way valve (2) and accumulator (4)
It constitutes a circulation cycle that is sucked into and performs heating operation. At this time, the three-way switching valve (8) is opened and closed as in the case of only the cooling operation described above.

The case of mainly heating in the simultaneous heating and cooling operation will be described with reference to FIG.

That is, the high-temperature high-pressure refrigerant gas discharged from the compressor (1) is sent to the relay device (E) through the first connecting pipe (6) as indicated by the dotted arrow in the figure, and then the first branch portion. (10), the three-way switching valve (8), the first connection pipes (6b), (6c) on the indoor unit side, in this order, flow into each indoor unit (B), (C) to be heated, The inside heat exchanger (5) exchanges heat with the indoor air to be condensed and liquefied to heat the inside of the room. Then, the condensed and liquefied refrigerant is controlled by the amount of subcool at the outlets of the indoor heat exchangers (B) and (C), passes through the first fully open flow rate control device (9), and is slightly decompressed to the second. Flows into the branch part (11). Then, a part of this refrigerant enters the indoor unit (D) that is going to be cooled through the second connection pipe 7d on the indoor unit side, and is controlled by the superheat amount at the outlet of the indoor heat exchanger (D). After entering the first flow rate control device (9) and being decompressed, it enters the indoor heat exchanger (5) to exchange heat, evaporate, and become a gas state to cool the room, and set the three-way switching valve (8). Through the gas-liquid separator (1
Inflow into 2).

On the other hand, the other refrigerant passes through the second branch portion (11) and the second flow rate control device (13) which is controlled by the openable and closeable high and low pressure values of the second connecting pipe, and the gas-liquid separation device. The heat source unit side heat exchanger (3) of the heat source unit (A) flows into the (12), joins the refrigerant passing through the indoor unit (D) to be cooled, joins the second connecting pipe (7), ) And exchanges heat to evaporate and become a gas state. Then, the refrigerant constitutes a circulation cycle in which it is drawn into the compressor (1) through the four-way valve (2) of the heat source device and the accumulator (4), and performs heating-main operation. At this time, the first port (8a) of the three-way switching valve (8) connected to the indoor units (B) and (C) is closed, and the second port (8b) and the third port (8c) are open. The second opening (8b) of the indoor unit (D) is closed, and the first opening (8a) and the third opening (8c) are open.

In addition, during this cycle, a part of the liquid refrigerant enters the bypass pipe (14) from the second connection pipes (7b), (7c) (7d) on the indoor unit side, and the third flow control device (15). The refrigerant that has been decompressed to a low pressure by the heat exchange sections (16b), (16c), and (16d) and then evaporated is the second check valve (18).
And enters the second connection pipe (7), flows into the heat source unit side heat exchanger (3) of the heat source unit (A), exchanges heat and evaporates to become a gas state. Then, the refrigerant is sucked into the compressor (1) through the four-way valve (2) of the heat source device and the accumulator (4). At this time, the first connecting pipe (6) has a high pressure, and the second connecting pipe (7) has a low pressure.
8) Circulate on the side. On the other hand, the refrigerant that has undergone heat exchange in the heat exchange parts (16b) and (16c) and has been subcooled is flowed into the second branch part (11) and further heat-exchanged and cooled in the heat exchange part (16d). Then, the subcool is sufficiently attached and the air flows into the indoor unit (D) which is about to be cooled. A case of mainly cooling in the cooling / heating simultaneous operation will be described with reference to FIG.

That is, as shown by the solid arrow in the figure, the refrigerant gas discharged from the compressor (1) exchanges an arbitrary amount with the heat source side heat exchanger (3) to become a two-phase high temperature and high pressure state. The gas-liquid separator (12) of the repeater (E) through the connecting pipe (7) of
Sent to. Then, here, the gaseous refrigerant is separated into a gaseous refrigerant and a liquid refrigerant, and the separated gaseous refrigerant is separated into the first branch (1
0), three-way switching valve (8), first connection pipe (6
In the order of d), the air flows into the indoor unit (D) to be heated, heat-exchanges with the indoor air in the indoor heat exchanger (D) to be condensed and liquefied, and heats the room. Furthermore, the indoor heat exchanger (D)
It is controlled by the amount of subcool at the outlet and is almost fully open.
After passing through the flow control device (9), the pressure is slightly reduced and flows into the second branch portion (11). On the other hand, the remaining liquid refrigerant is provided in the second connecting pipe (7), passes through the second flow rate control device (13) controlled by the pressure difference before and after the second connecting pipe (7), and then flows into the second branch portion (11). The refrigerant flows in and merges with the refrigerant having passed through the indoor unit (D) to be heated. And the second branch (11),
Pass the second connection pipes (7b) and (7c) on the indoor unit side in this order,
It flows into each indoor unit (B), (C). Then, the refrigerant flowing into each indoor unit (B), (C) is low in pressure by the first flow rate control device (9) controlled by the superheat amount at the outlets of the indoor heat exchangers (B), (C). It is decompressed and heat-exchanges with room air to evaporate and gasify to cool the room. Further, the refrigerant in the gas state is supplied to the indoor unit-side first connection pipes (6b) and (6c) three-way switching valve (8), the first branch portion (10), and the first connection pipe (6). ), A four-way valve (2) of the heat source unit, and an accumulator (4) to form a circulation cycle which is sucked into the compressor (1) to perform a cooling main operation. At this time, the first port (8a), the second port (8b), and the third port (8c) of the three-way switching valve (8) connected to the indoor units (B), (C), (D) are mainly heated. It is opened and closed like driving. In addition, during this cycle, a part of the liquid refrigerant enters the bypass pipe (14) from the confluence of the second connection pipes (7b), (7c), (7d) on each indoor unit side, and reaches the third flow rate. The pressure is reduced to a low pressure by the control device (15) and the heat exchange parts (16b), (16c), (16d)
The heat-exchanged and evaporated refrigerant passes through the first check valve (17), enters the first connecting pipe (6), and passes through the four-way valve (2) of the heat source device and the accumulator (4). Inhaled by the compressor (1). At this time, the first connecting pipe (6) is at a low pressure and the second connecting pipe (7) is at a high pressure.
Flow through the check valve (17) side. Meanwhile, heat exchange part (16d)
The refrigerant that has undergone heat exchange with and has been subcooled flows into the second branch portion (11), and then flows into the second branch portion (11).
To the indoor units (B) and (C) that are going to be cooled by being heat-exchanged in the heat exchange sections (16b) and (16c), respectively, and further cooled with sufficient subcool.

In the above embodiment, the three-way switching valve (8) is provided and the first connection pipes (6b), (6c), (6d) on the indoor unit side and the first connection pipe (6) or the second connection pipe (6). Although it is switchably connected to the connection pipe (7), as shown in FIG. 5, two solenoid valves (30), (31) and other on-off valves are provided and switchably connected as described above. Also has the same effect.

〔The invention's effect〕

As described above, the air conditioner of the present invention includes a compressor, a switching valve, a heat source unit side heat exchanger, and other heat source units, and a plurality of indoor units each having an indoor side heat exchanger, In a case where the indoor heat exchangers of the plurality of indoor units are connected to each other via the first and second connecting pipes, the one of the indoor heat exchangers is switchably connected to the first connecting pipe or the second connecting pipe. From one branch part, a second branch part connected to the other of the indoor heat exchangers of the plurality of indoor units and connected to the second connection pipe, and from the second connection pipe A pipe branch portion that branches to branch the pipe that reaches the first branch portion, and a pipe path that connects the pipe branch portion and the other of the indoor heat exchangers is provided in the middle, and And a flow control device for controlling the second connecting pipe having the same diameter as the first connecting pipe. Single-phase state and a gas, which is constituted in diameter necessary for the passage of refrigerant in the liquid mixed phase. Therefore, air conditioning is selectively used, and in one of the indoor units, air conditioning,
The other indoor unit can be heated at the same time. Further, in the case of mainly heating in the simultaneous heating / cooling operation, the second connection pipe interposed between the heat source unit and the indoor unit has the same diameter as the first connection pipe, so the indoor heat exchanger of the indoor unit to be cooled. Since the pressure difference between the evaporating pressure of 1 and the evaporating pressure of the heat source side heat exchanger is small, the evaporating pressure of the indoor side heat exchanger does not increase, so that the cooling capacity does not become insufficient. Also,
Since the evaporation pressure of the heat exchanger on the side of the heat source does not decrease, the heat exchanger can be operated without icing and without decreasing its capacity. Further, also in the case of mainly cooling in the heating / cooling simultaneous operation, similarly, since the second connection pipe interposed between the heat source unit and the indoor unit has the same diameter as the first connection pipe,
Since the pressure difference between the condensing pressure of the indoor heat exchanger of the indoor unit to be heated and the condensing pressure of the heat source machine side heat exchanger becomes small, the condensing pressure of the indoor heat exchanger will not decrease, so the heating capacity There is no shortage. Further, since the condensing pressure of the heat exchanger on the heat source unit side does not rise, it is possible to operate without performing high cut.

[Brief description of drawings]

FIG. 1 is an overall configuration diagram centering on the refrigerant system of the air conditioner of the first embodiment of the present invention. FIG. 2 is a diagram showing the operation operation state of only the cooling or heating of the embodiment shown in FIG. 1, and FIG. 3 is the heating main body of the embodiment shown in FIG. 1 (the heating operation capacity is larger than the cooling operation capacity. Case) operation status diagram,
FIG. 4 is an operation state diagram showing the cooling main body (when the cooling operation capacity is larger than the heating operation capacity) of the embodiment shown in FIG. 1, and FIG. 5 is an air conditioner of another embodiment of the present invention. 2 is an overall configuration diagram centering on the refrigerant system of FIG. In the figure, (A) is a heat source device, (B), (C), (D)
Is an indoor unit, (E) is a relay, (1) is a compressor, (2) is a switching valve, (3) is a heat source side heat exchanger, (4) is an accumulator, and (5) is indoor heat exchange. Vessel, (6) first connection pipe, (6b), (6c), (6d) first indoor connection pipe, (7) second connection pipe, (7b), (7c) , (7d)
Is a second connection pipe on the indoor side, (8) is a three-way switching valve,
(9) is the first flow controller, (10) is the first branch,
(11) is the second branch, (12) is a gas-liquid separator, (13)
Is the second flow controller, (14) is bypass piping, (15)
Is a third flow control device, (16b), (16c) and (16d) are heat exchange parts, and (17) and (18) are first and second check valves. In the drawings, the same reference numerals indicate the same or corresponding parts.

Claims (1)

[Claims] 1. A heat source unit A comprising a compressor 1, a switching valve 2, a heat source unit side heat exchanger 3 and the like, and a plurality of indoor units B, C and D each having an indoor side heat exchanger 5. Of the indoor heat exchangers 5 of the plurality of indoor units B, C, D are connected to each other via the first and second connecting pipes 6 and 7. Alternatively, it is connected to the first branch portion 10 that is switchably connected to the second connection pipe 7 and the other of the indoor heat exchangers 5 of the plurality of indoor units B, C, D, and the second A second branch portion 11 connected to the connection pipe 7, a pipe branch portion 12 that branches the pipe that branches from the second connection pipe 7 and reaches the first branch portion 10, and the pipe branch portion. The second connection pipe 7 is provided with flow rate control devices 9 and 13 which are provided in the middle of a pipeline connecting the section 12 and the other of the indoor heat exchangers 5 and control the flow rate of the flowing refrigerant. 1 connection pipe 6 and the same diameter as the gas single-phase state and a gas, an air conditioner which is characterized by being configured to diameter required for the passage of refrigerant in the liquid mixed phase.