JPH0752043B2 - Air conditioner - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a multi-chamber heat pump type air conditioner in which a plurality of indoor units are connected to one heat source unit, and in particular for each indoor unit. The present invention relates to an air conditioner capable of selectively performing heating and cooling in one indoor unit, and 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 is generally used, 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 performed. , Or all are configured to perform cooling.

[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 heating or cooling, so heating is performed in a place where cooling is required, or vice versa. There was a problem that cooling was done where heating was required.

In particular, when installed in a large-scale building, the load of air conditioning is remarkably different in an office automation room such as an interior part and a perimeter part, or a general office room and a 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 and computer room, etc. have been converted to OA. It is an object of the present invention to obtain a multi-room heat pump type air conditioner capable of coping with different loads of air conditioning in a room.

[Means for Solving the Problems]

The present invention relates to a single heat source unit including a compressor, a four-way valve, a heat source unit side heat exchanger, an accumulator and the like, and a plurality of indoor units including an indoor side heat exchanger, a first flow rate control device and the like. Connected via first and second connection pipes, one of the indoor heat exchangers of the plurality of indoor units is switchably connected to the first connection pipe or the second connection pipe. And a second branch part having a valve device for connecting to the other of the plurality of indoor heat exchangers via the first flow rate control device and connected to a second connection pipe. A second flow rate control device that is provided in the branching part and the second connecting pipe and connects the first branching part and the second branching part to each other, and drives the valve device and the second flow rate controlling device. And a drive device for controlling the valve device and the second device by the drive device when the operation is stopped. It is characterized in that so as to closed the quantity control device.

[Action]

In the present invention, in the case of heating mainly in the simultaneous heating and cooling operation, the high pressure gas refrigerant is introduced into each indoor unit to be heated from the first connecting pipe and the first branch portion to perform heating, and then the refrigerant is A part of the branch portion 2 flows into the indoor unit that is going to be cooled to perform cooling, and then flows into the second connecting pipe from the first branch portion. On the other hand, the remaining refrigerant is
It merges with the refrigerant that has passed through the cooling indoor unit through the second flow rate control device, flows into the second connection pipe, and returns to the heat source unit.

Further, in the case of mainly cooling, an attempt is made to heat the high-pressure gas refrigerant in the two-phase state by exchanging an arbitrary amount of heat in the heat source side heat exchanger to heat the gaseous refrigerant from the second connecting pipe through the first branch portion. It is introduced into the indoor unit to be heated and flows into the second branch portion. On the other hand, the remaining liquid refrigerant passes through the second flow rate control device and merges with the refrigerant that has passed through the indoor unit to be heated at the second branch portion and flows into each indoor unit to be cooled to cool it. After that, it returns from the first branch portion to the heat source machine through the first connecting pipe.

Further, in the heating operation only, the refrigerant passes through the first connection pipe and the first branch portion from the heat source unit, is introduced into each indoor unit, is heated, and passes through the second connection pipe from the second branch portion. Return to the heat source machine.

Then, in the case of only the cooling operation, the refrigerant is introduced into each indoor unit from the heat source unit through the second connection pipe and the second branch section,
It cools and returns from the 1st branch part to the heat source machine through the 1st connection piping.

When the operation is stopped, the valve device of the first branch portion and the second valve device
By closing the flow rate control device, the heat source unit side and the indoor unit side are separated and shut off, and an excessive amount of refrigerant is retained on the indoor unit side to prevent excessive refrigerant return to the heat source unit side. However, the liquid back operation of the compressor at the next start is prevented.

〔Example〕

 Examples of the present invention will be described below.

FIG. 1 is an overall configuration diagram centering on a refrigerant system of an air conditioner according to an embodiment of the present invention. Further, FIGS. 2 to 4 show the operation state during the cooling and heating operation in the embodiment of FIG. 1, and FIG. 2 is the operation state diagram only for cooling or heating, FIG. 3 and FIG. The figure shows the operation of cooling and heating simultaneous operation. Fig. 3 shows heating mainly (when the heating operation capacity is larger than the cooling operation capacity), and Fig. 4 shows cooling mainly (when the cooling operation capacity is larger than the heating operation capacity). FIG. FIG. 5 is a state diagram when the operation is stopped in the embodiment of FIG.

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

Further, the valve device and the flow rate control device in the closed state in the figure are painted black to distinguish them.

In FIG. 1, (A) is a heat source machine, and (B), (C), and
As will be described later, (D) is an indoor unit connected in parallel with each other and has the same configuration. (E) is a first branch portion, a second flow rate control device, a second branch portion, as will be described later.
A repeater with a built-in gas-liquid separator. (1) is a compressor,
(2) is a four-way valve that switches the refrigerant flow direction of the heat source unit,
(3) is a heat source unit side heat exchanger, (4) is an accumulator, and the above-mentioned devices (1) to (4) constitute the heat source unit (A). (5) is three indoor heat exchangers, (6) is the first connecting pipe connecting the four-way valve (2) of the heat source unit (A) and the relay unit (E), (6a), (6b) ) And (6c) connect the indoor heat exchanger (5) and the relay (E) of the indoor units (B), (C), and (D), respectively, and correspond to the first connection pipe (6). The first connection pipe on the indoor unit side, (7) is the second connection pipe connecting the heat source unit side heat exchanger (3) of the heat source unit (A) and the relay unit (E), one end of which is the heat source unit side. It is connected to the heat exchanger (3) and the other end is connected to the second connection pipes (7b), (7c), (7d) on the indoor unit side, which will be described later, in the second branch section (11), It forms a branch point. (7b), (7c), and (7d) respectively connect the indoor heat exchanger (5) of the indoor units (B), (C), and (D) and the relay unit (E) to the second connection pipe ( The second connection pipe on the indoor unit side corresponding to 7), (8a) connects the first connection pipes (6b), (6c), (6d) on the indoor side to the first connection pipe (6). Open / close valve, (8b) is the first connection pipe (6
b), (6c), (6d) and an on-off valve that connects the second connecting pipe (7), (9) is connected close to the indoor heat exchanger (5), and indoor heat exchange during cooling The first flow rate control device is controlled by the superheat amount on the outlet side of the device (5) and the subcool amount during heating, and the second connection pipe (7
b), (7c), (7d). (10) is a first connection pipe (6b), (6c), (6d) on the indoor unit side, an on-off valve (8a) that connects the first connection pipe (6), and a first connection on the indoor side. A first branch portion including an on-off valve (8b) connecting the pipes (6b), (6c), (6d) and the second connection pipe (7),
(11) is the second connection pipe (7b), (7c) on the indoor unit side,
A second branch consisting of (7d) and a second connecting pipe (7),
(12) is a gas-liquid separator provided in the middle of the second connecting pipe (7), the gas phase part of which is connected to the on-off valve (8b) of the first branch part (10), The section is connected to the second branch section (11) through a second flow control device (13) that can be opened and closed.

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, in the figure, the four-way valve (2) connects the compressor (1) and the heat source side heat exchanger (3) as shown by the solid line,
Further, the cooling side operating state in which the first connecting pipe (6) and the accumulator (4) are connected is set, and the high temperature high pressure refrigerant gas discharged from the compressor (1) is 4 as shown by a solid arrow in the figure.
After passing through the one-way valve (2) and undergoing heat exchange in the heat source side heat exchanger (3) to be condensed and liquefied, the second connection pipe (7), the gas-liquid separation device (12), and the second flow rate control The device (13) is passed in this order, the second branch part (11) and the indoor unit side second connection pipe (7
b), (7c), (7d), each indoor unit (B), (C)
-Inflow into (D). And each indoor unit (B), (C)
The refrigerant flowing into (D) is decompressed to a low pressure by the first flow rate control device (9) which is controlled by the superheat amount at the outlet of each indoor heat exchanger (5), and then the indoor heat exchanger (5) ), Heat exchange with indoor air to evaporate and gasify to cool the room. The refrigerant in the gas state is supplied to the indoor unit-side first connection pipes (6b), (6c), (6d), the opening / closing valve (8a), the first branch portion (10), and the first branch pipe (10). Connection piping (6), 4-way valve (2) of heat source machine, accumulator (4)
After that, a circulation cycle that is sucked into the compressor (1) is configured, and the cooling operation is performed. At this time, the open / close valve (8a) is open and the open / close valve (8b) is closed.

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

That is, in the figure, the four-way valve (2) connects the compressor (1) and the first connecting pipe (6) as shown by the dotted line, and the heat source side heat exchanger (3) and the accumulator (4) are connected. In the operating state on the heating side, the high temperature high pressure refrigerant gas discharged from the compressor (1) is
The first connecting pipe (6), the first branch portion (10), the opening / closing valve (8a), the first connecting pipes (6b), (6c), (on the indoor unit side) passing through the one-way valve (2). 6d) in the order of each indoor unit (B)
It flows into (C) and (D), heat-exchanges with the indoor air to be condensed and liquefied, 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. The pressure is reduced to a low-pressure two-phase state by 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 that has evaporated to a gas state constitutes a circulation cycle in which the refrigerant is sucked into the compressor (1) through the four-way valve (2) of the heat source device and the accumulator (4) to perform the heating operation. At this time, the on-off valves (8a) and (8b) are opened and closed as in the case of only the cooling operation described above.

Next, a case of mainly heating in the simultaneous heating and cooling operation will be described with reference to FIG. Here, the indoor unit (B)
Let (C) be heating and (D) be cooling.

That is, in the figure, the four-way valve (2) connects the compressor (1) and the first connecting pipe (6) as shown by the dotted line, and the heat source side heat exchanger (3) and the accumulator (4) are connected. Is set to the heating side connecting state, and the high-temperature high-pressure refrigerant gas discharged from the compressor (1) is sent to the relay machine (E) through the first connecting pipe (6) as shown by the dotted arrow in the figure. Each indoor unit (B) to be heated passes through the first branch portion (10), the opening / closing valve (8a), and the first connection pipes (6b) and (6c) on the indoor unit side in this order. It flows into (C) and heat-exchanges with the indoor air in the indoor heat exchanger (5) to be condensed and liquefied to heat the room. Then, the condensed and liquefied refrigerant passes through the first flow rate control device (9) in a substantially fully opened state, which is controlled by the subcool amount at the outlet of each indoor heat exchanger (5), and is slightly decompressed to the second branch portion. It flows into (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 (5). After entering the first flow rate control device (9) and being decompressed, it enters the indoor heat exchanger (5) to exchange heat and evaporate to become a gas state to cool the room, and to open the on-off valve (8b). Gas-liquid separator through (12)
Flow into.

On the other hand, the other refrigerant flows through the second branch portion (11), the high pressure / low pressure, and the second flow rate control device (13) controlled by the inlet side pressure value of the second flow rate control device (13). Then, it flows into the gas-liquid separation device (12), merges with the refrigerant having passed through the indoor unit (D) to be cooled, flows into the second connection pipe (7), and is located on the heat source unit side of the heat source unit (A). It flows into the heat exchanger (3), exchanges heat and evaporates into a gas state. Then, the refrigerant constitutes a circulation cycle in which it is drawn into the compressor (1) via the four-way valve (2) of the heat source device and the accumulator (4), and performs heating-main operation. At this time, the indoor unit (B) that is about to be heated
The open / close valve (8a) connected to (C) is open, the open valve (8b) is closed, the open / close valve (8a) connected to the indoor unit (D) to be cooled is closed, and (8b) is open. Has been done.

Next, a case of mainly cooling in the cooling / heating simultaneous operation will be described with reference to FIG. Here, the indoor unit (B)
Let (C) be cooling and (D) be heating.

That is, in the figure, the four-way valve (2) connects the compressor (1) and the heat source side heat exchanger (3) as shown by the solid line,
In addition, the high-temperature high-pressure refrigerant gas discharged from the compressor (1) as shown by the solid line arrow in the figure is the operating state on the cooling side connecting the first connection pipe (6) and the accumulator (4),
An arbitrary amount of heat is exchanged in the heat source side heat exchanger (3) to form a two-phase high temperature and high pressure state, which is sent to the gas-liquid separation device (12) of the repeater (E) through the second connection pipe (7). . Then, here, the gaseous refrigerant is separated into a liquid refrigerant, and the separated gaseous refrigerant is a first branch portion (10), an opening / closing valve (8b), an indoor unit side first connection pipe (6d), In order to heat the room, it flows into the indoor unit (D) to be heated, heat-exchanges with the indoor air in the indoor heat exchanger (5) to be condensed and liquefied, and heats the room. Furthermore,
It is controlled by the amount of subcool at the outlet of the indoor heat exchanger (5), passes through the first flow rate control device (9) in a substantially fully opened state, is slightly decompressed, and flows into the second branch section (11).

On the other hand, the remaining liquid refrigerant passes through the second flow rate control device (13) controlled by the high pressure / low pressure and the outlet side pressure value of the second flow rate control device (13) to the second branch section (11). ), And merges with the refrigerant having passed through the indoor unit (D) to be heated. Then, the second branch portion (11) and the second connection pipes (7b) and (7c) on the indoor unit side are passed in this order to the indoor units (B) and
It flows into (C). The refrigerant flowing into each indoor unit (B) / (C) is controlled by the amount of superheat at the outlet of each indoor heat exchanger (5), the first flow rate control device (9).
The pressure is reduced to a low pressure by means of heat exchange with the room air to evaporate and gasify and cool the room. Further, the refrigerant in the gas state is supplied to the first connection pipes (6b), (6
b), on-off valve (8a), first branch part (10), first connecting pipe (6), four-way valve (2) of heat source machine, and intake to compressor (1) via accumulator (4) The cooling cycle is configured to perform the cooling main operation. At this time, the indoor unit (B)
The on-off valves (8a) and (8b) connected to (C) and (D) are opened and closed as in the heating main operation.

Furthermore, the state when the operation is stopped will be described with reference to FIG.

That is, when the operation is stopped, as shown in the figure, both the on-off valves (8a) and (8b) of the first branch section are closed, and the second flow rate control device (13) is also fully closed.
To separate and block the heat source unit (A) side and the indoor units (B), (C), (D) side, and to retain a considerable amount of refrigerant on the indoor unit (B), (C), (D) side. Therefore, the excessive refrigerant return to the heat source unit (A) side is prevented, and the liquid back operation of the compressor (1) at the next start is prevented.

Next, the control of the four-way valve, the on-off valve, and the second flow rate control device at the time of operation stop in the above one embodiment will be described with reference to FIG.
This will be described with reference to FIG. FIG. 6 is a block diagram of the above control, and FIG. 7 is its flow chart.

In FIG. 6, each indoor unit operation mode determining means (14),
And the indoor unit capacity determining means (15) obtains the ratio of the operation stop and cooling / heating operating capacity by the operation mode determining means (16), and accordingly, the four-way valve operation determining means (17) and the on-off valve operation determining means. (18) The second flow control device opening degree determining means (19) determines the operations of the four-way valve (2), the open / close valves (8a) and (8b), and the second flow control device (13). Then 4
The four-way valve (2), the on-off valves (8a) and (8b), the second flow rate by the one-way valve drive device (20), the on-off valve drive device (21), and the second flow rate control device drive device (22). Drive the control device (13).

In FIG. 7, the 4-way valve (2), the on-off valves (8a) and (8
b) shows a flow chart of the operation determination control of the second flow rate control device (13).

In the same figure, the presence or absence of the driving indoor unit is determined in step (23). If the driving indoor unit is present, the process proceeds to step (24), and if not, the process proceeds to step (31). The step (24) compares and judges the cooling operation capacity for performing the cooling operation and the heating operation capacity for performing the heating operation in the operation indoor unit. If the cooling operation capacity is larger, the step (25) is performed, otherwise the step (25) is performed. Proceed to (26).

In step (25), it is judged whether or not the indoor unit is only in the cooling operation, and if it is only in the cooling operation, the process proceeds to step (27), and if not, the process proceeds to step (28). On the other hand, in step (26), it is determined whether or not the operating indoor unit is only in heating operation, and if it is only in heating operation, the process proceeds to step (29), and if not, the process proceeds to step (30).

Steps (27) to (31) separated by the above judgment
Respectively correspond to the examples of the operating state described with reference to FIGS. 2 to 5.

That is, the step (27) is only for the cooling operation described in FIG. 2, and the four-way valve (2) is for the cooling side and the on-off valve (8
a) is open and the open / close valve (8b) is closed.

The step (28) is mainly for cooling in the simultaneous cooling and heating operation described in FIG. 4, the four-way valve (2) is on the cooling side, and the on-off valve (8a) connected to each indoor unit to be cooled is open circuit. The open / close valve (8b) is closed, the open / close valve (8a) connected to each indoor unit to be heated is closed, and the open / close valve (8b) is open.

The step (29) is only for the heating operation described in FIG. 2, the four-way valve (2) is on the heating side, the open / close valve (8a) is open,
The on-off valve (8b) is closed.

The step (30) is for heating mainly in the simultaneous cooling and heating operation described in FIG. 3, the four-way valve (2) is on the heating side, and the on-off valve (8a) connected to each indoor unit to be heated is open circuit. The open / close valve (8b) is closed, the open / close valve (8a) connected to each indoor unit to be cooled is closed, and the open / close valve (8b) is open.

Step (31) is the case when the operation is stopped as described in FIG. 5, where the four-way valve (2) is on the cooling side, the open / close valve (8a) is closed, the open / close valve (8b) is closed, and the second flow rate control is performed. The device (13) is fully closed.

In steps (27) to (30), the opening of the second flow rate control device (13) is not determined.

〔The invention's effect〕

As described above, the air conditioner of the present invention is a compressor,
One heat source unit including a four-way valve, a heat source unit side heat exchanger, an accumulator, etc., and a plurality of indoor units including an indoor side heat exchanger, a first flow rate control unit, etc. A valve device for connecting one of the indoor heat exchangers of the plurality of indoor units to the first connection pipe or the second connection pipe so as to be switchable. A first branch part having and a second branch part connected to the other of the plurality of indoor heat exchangers via a first flow rate control device and connected to a second connection pipe. , Above second
A second flow control device provided in the connection pipe of No. 1 for communicating the first branch part and the second branch part, and a drive device for driving the valve device and the second flow control device. When the operation is stopped, the valve device and the second flow rate control device are closed by the drive device. Therefore, cooling and heating can be selectively performed, and cooling can be performed in one indoor unit and heating can be performed in the other indoor unit at the same time. Further, when the operation is stopped, the valve device and the second flow rate control device are closed. , Each indoor unit side from the valve device and the second flow rate control device is blocked, and since the same amount of refrigerant as in operation is retained in the blocked part, excessive refrigerant does not return to the heat source device, A large amount of refrigerant does not stagnate in the compressor when stopped, liquid compression does not occur when the compressor is started, and liquid back operation from the accumulator can be prevented.

[Brief description of drawings]

FIG. 1 is an overall configuration diagram centered on a refrigerant system of an air conditioner of one embodiment of the present invention, FIG. 2 is an operation state diagram of only the cooling or heating of one embodiment shown in FIG. 1, FIG. 3 is a diagram showing the operation state of the heating main body (when the heating operation capacity is larger than the cooling operation capacity) of the embodiment shown in FIG. 1, and FIG. 4 is the cooling main body of the embodiment shown in FIG. (A case where the cooling operation capacity is larger than the heating operation capacity), which is an operation state diagram, FIG. 5 is a state diagram when operation is stopped in the embodiment shown in FIG. 1,
FIG. 6 is a control block diagram of the embodiment shown in FIG. 1, and FIG. 7 is a flow chart thereof. In the figure, (A) is a heat source device, (B), (C), (D)
Is an indoor unit, (E) is a repeater, (1) is a compressor, (2) is a four-way valve of a heat source unit, (3) is a heat source side heat exchanger, (4) is an accumulator, and (5) is Indoor side heat exchanger, (6) first connection pipe, (6b), (6c), (6d) first indoor unit connection pipe, (7) second connection pipe, (7b) , (7
c) and (7d) are the second connection pipes on the indoor unit side, (8a) and (8
b) is a valve device, (9) is a first flow control device, (10) is a first branch part, (11) is a second branch part, and (13) is a second flow control device. In the drawings, the same reference numerals indicate the same or corresponding parts.

Claims (1)

[Claims] 1. A heat source unit comprising a compressor, a four-way valve, a heat source unit side heat exchanger, an accumulator and the like, and a plurality of indoor units comprising an indoor side heat exchanger, a first flow control device and the like. In which one of the indoor heat exchangers of the plurality of indoor units can be switched to the first connection pipe or the second connection pipe, A first branch part having a valve device connected to the other side, and the other of the plurality of indoor heat exchangers connected to each other via the first flow rate control device and to the second connection pipe. A second flow control device, which is provided in the second branch portion and the second connection pipe, and which communicates the first branch portion and the second branch portion, the valve device, and the second flow rate. A drive device for driving the control device, and when the operation is stopped, the valve device and the valve device are provided by the drive device. An air conditioning apparatus is characterized in that so as to closed the second flow control device.