JPH079319B2 - Multi-type air conditioner - Google Patents

Description

The present invention relates to a heat pump type multi-type air conditioner in which a plurality of indoor units are connected to a single outdoor unit by a refrigerant pipe.
In particular, the present invention relates to a multi-type air conditioner improved so that a plurality of indoor units can be appropriately combined with cooling and heating operations at the same time.

(Prior Art) Conventionally, a refrigeration cycle of this type of multi-type air conditioner is configured as shown in FIG. 6, and includes a compressor 1, a four-way valve 2, an outdoor heat exchanger 3, a first expansion device 3a, The second expansion devices 4a, 4b, 4c, the indoor heat exchangers 5a, 5b, 5c, and the two-way valves 6a, 6b,
The indoor heat exchanger circuit 7 connecting each series circuit with 6c in parallel is connected in this order sequentially and annularly by the refrigerant pipe 8 to form a closed refrigeration cycle for circulating the refrigerant, and the four-way valve 2 is appropriately used. The room can be cooled or heated by switching.

That is, when the refrigerant circulates in the refrigeration cycle in the direction of the solid line arrow in the figure by the switching operation of the four-way valve 2, the cooling operation is performed, and conversely, the heating operation is performed when the refrigerant circulates in the refrigeration cycle in the direction of the broken line arrow in the figure.

(Problems to be solved by the invention) However, in such a conventional multi-type air conditioner, the flow direction of the refrigerant flowing in the plurality of indoor heat exchangers 5a to 5c is always the same during cooling and heating, The plurality of indoor heat exchangers 5a to 5c cannot simultaneously perform the cooling operation and the heating operation in an appropriate combination, and in that case, an air conditioner is provided for each room and each is independently operated. Therefore, there is a problem that the initial cost and the running cost increase.

Therefore, the present invention has been made in view of the above circumstances, and an object thereof is to provide a low-cost multi-type air conditioner capable of simultaneously performing cooling operation and heating operation for each indoor heat exchanger with a simple configuration. To provide.

[Structure of Invention]

(Means for Solving Problems) The present invention is to enable a plurality of indoor units connected to one outdoor unit to be appropriately combined with cooling and heating operations.

That is, according to the present invention, the first expansion device is connected to one end of the outdoor heat exchanger that is connected to the compressor via the four-way valve, and the first expansion device is connected to the second expansion device and the indoor heat exchange. In the multi-type air conditioner connecting the indoor heat exchanger circuit connecting a plurality of series circuits of the device and the two-way valve in parallel, in the middle of the refrigerant pipe connecting the outdoor heat exchanger to the four-way valve, While connecting the main pipe part of the connecting pipe that branches into multiple limbs, connect each branch pipe end part of this connecting pipe in the middle of each series circuit between each indoor heat exchanger and each two-way valve. While connecting each and inserting an on-off valve in each branch pipe,
Among the plurality of indoor heat exchangers, when performing simultaneous heating and cooling operation for at least one of the indoor heat exchangers, the four-way valve is operated so that the cooling load and the heating load are compared to operate in the mode with the larger load. It is characterized in that a control means is provided for controlling the compressor so that the compressor is operated according to the difference between the heating and cooling loads when the switching operation is performed.

(Operation) By closing all the on-off valves and opening all the two-way valves, all the chambers can be opened by opening all the two-way valves in the same direction so that the refrigerant flows in the multiple indoor heat exchangers. Either the cooling operation or the heating operation can be simultaneously performed on the inner heat exchanger.

Here, if only the required on-off valve is opened, the required indoor heat exchanger of the indoor heat-exchanger circuit opened by this opened on-off valve will have a refrigerant flow direction of other indoor heat exchangers. When the refrigerant flows backward in the opposite direction and the other indoor heat exchanger is performing cooling operation or the like as an evaporator, for example, the required indoor heat exchanger performs heating operation or the like as a radiator.

That is, according to the present invention, the cooling operation and the heating operation can be appropriately combined and simultaneously performed for each of the plurality of indoor heat exchangers.

Therefore, according to the present invention, it is possible to arrange a plurality of indoor heat exchangers in a plurality of chambers, respectively, and to perform an appropriate combination of cooling and heating operations at the same time, so that a plurality of air conditioners are respectively provided in the plurality of chambers. The cost can be reduced as compared with the case where the heating and cooling operations are performed independently of each other.

Further, according to the present invention, when the cooling and heating operations are simultaneously performed for at least one of the plurality of indoor heat exchangers, the control unit causes the compressor to operate due to the difference in the heating and cooling loads. As compared with the conventional case where an air conditioner is provided for each room and air conditioning operation is performed individually, it is possible to reduce the operation load and the running cost.

(Embodiment) An embodiment of the present invention will be described below with reference to FIGS. 1 to 5.

FIG. 1 shows a refrigeration cycle of one embodiment of the present invention. In the figure, an inverter-driven compressor 11, a four-way valve 12, an outdoor heat exchanger 13, a first expansion device 14, an indoor heat exchanger are shown. The circuit 15 is sequentially and annularly connected by a refrigerant pipe 16 in this order to form a closed refrigeration cycle for circulating the refrigerant.

The indoor heat exchanger circuit 15 includes the first expansion device 14 and the four-way valve.
A part of the low-pressure side refrigerant pipe 16 connecting with 12 is configured into, for example, branch pipes 16a, 16b, 16c that branch into three branches.
16c includes first, second, and third indoor heat exchangers 17a, 17b, 1
7c respectively, and each indoor heat exchanger 17a-1
7c and the first diaphragm device 14 between the second diaphragm device 18a, 18
b and 18c respectively, and each indoor heat exchanger 17a
Two-way valves 19a, 19b, and 19c are interposed between ~ 17c and the four-way valve 12, respectively.

The end of the main pipe 21 of the connecting pipe 20 that branches into, for example, three branches is connected in the middle of the high-pressure side refrigerant pipe 16 that connects the four-way valve 12 and the outdoor heat exchanger 13. Each branch of the crotch 22
a, 22b, each end of 22c is connected in the middle of each branch pipe 16a ~ 16c connecting each indoor heat exchanger 17a ~ 17c and each two-way valve 19a ~ 19c in the indoor heat exchanger circuit 15, Open / close valves 23a, 23b, and 23c are provided in the branch pipes 22a to 22c, respectively.

The on-off valves 23a to 23c pass the refrigerant only in one direction indicated by a broken line arrow in the drawing when the valves are opened, and the two-way valves 19a to 19c pass the refrigerant in two directions when the valve is opened.

The on-off valves 23a to 23c, the two-way valves 19a to 19c, and the valve openings of the second expansion devices 18a to 18c are appropriately controlled by remote operation of the multi-controller 24. Is configured so that the capacity of the inverter-driven compressor 11 can be appropriately controlled by remote control.

Next, the operation of this embodiment will be described.

First, a case will be described in which all the first, second, and third indoor heat exchangers 17a to 17c are simultaneously cooled or heated.

In this case, the opening degree of each of the second expansion devices 18a to 18c is appropriately set by remote operation of the multi-controller 24, and all the two-way valves 19a to 19c are opened, while the all open valves 23a to 23c are closed.

After this, when the refrigerant is circulated in the direction of the solid line arrow in FIG. 1 by an appropriate switching operation of the four-way valve 12, all the indoor heat exchangers 17 are placed.
a to 17c act as an evaporator to perform cooling operation.

That is, the high-temperature high-pressure gas refrigerant discharged from the compressor 11 is guided by the four-way valve 12, radiates heat in the outdoor heat exchanger 13 and is liquefied, and is first decompressed by the first expansion device 14 and then the chamber. The flow is divided into the respective branch pipes 16a to 16c of the inner heat exchange circuit 15, and the pressure is reduced again by the respective second expansion devices 18a to 18c. After that, the vapor is evaporated in the indoor heat exchangers 17a to 17c to form the liquid refrigerant. The ambient heat is absorbed and cooled by the latent heat of vaporization, and is guided by each of the two-way valves 19a to 19c that are being opened and merges again, and then returns to the compressor 11 via the four-way valve 12.

When the four-way valve 12 is switched to circulate the refrigerant in the direction of the broken line arrow in FIG. 1, all of the first, second and third indoor heat exchangers 17a to 17c act as radiators. , Switch the heating operation.

Next, a case will be described in which a plurality of indoor heat exchangers 17a to 17c are simultaneously combined by appropriately combining the cooling operation and the heating operation.

For example, when performing the cooling operation for the first and second indoor heat exchangers 17a and 17b and performing the heating operation for the third indoor heat exchanger 17c, the outdoor heat exchange is performed by remote operation of the multi-controller 24. The flow direction of the refrigerant in the container 13 is the first
The switching operation of the four-way valve 12 is performed so as to face the direction of the solid line arrow in the figure, and the first and second indoor heat exchangers 17a and 17b are also operated.
The two-way valves 19a and 19b, which are respectively connected to each other, are opened and the on-off valves 23a and 23b are closed, while the third indoor heat exchanger 17c is connected.
The two-way valve 19c communicating with is closed and the on-off valve 23c is opened.

Therefore, the high-temperature and high-pressure gaseous refrigerant flowing out from the four-way valve 12 is split into the outdoor heat exchanger 13 and the connecting pipe 20, respectively.

First, the high-temperature and high-pressure gaseous refrigerant diverted to the outdoor heat exchanger 13 radiates heat here and is liquefied.
The second expansion devices 1 that are decompressed by the expansion device 14 and then communicate with the first and second indoor heat exchangers 17a and 17b, respectively.
8a, 18b, and does not flow into the second expansion device 18a communicating with the third indoor heat exchanger 17c. This is because the pressure on the side of the second expansion device 18c becomes lower than the high pressure on the side of the on-off valve 23c which is open in communication with the third indoor heat exchanger 17c.

Therefore, the liquid refrigerant flows in the first and second indoor heat exchangers 17a and 17b in the direction of the solid line arrow to evaporate, is cooled by the latent heat of vaporization of the liquid refrigerant, and is opened as a gas refrigerant in each two-way valve 19a. ,
Guided by 19b, the four-way valve 12 is returned to the compressor 11.

Therefore, the first and second indoor heat exchangers 17a and 17b are cooled.

On the other hand, the high-temperature and high-pressure gaseous refrigerant that has branched to the connecting pipe 20 is guided only to the open / close valve 23c in the three-branch branch pipes 22a to 22c, and flows in the third indoor heat exchanger 17c. It flows in the direction of the broken line arrow in FIG. 1, radiates heat to liquefy in the third indoor heat exchanger 17c, and is further decompressed as a liquid refrigerant by the second expansion device 18c, and then another second expansion device. It merges with the devices 18a, 18b, and flows in the first and second indoor heat exchangers 17a, 17b in the direction of the solid line arrow in FIG. 1 to evaporate.

Therefore, only the third indoor heat exchanger 17c is heated.

Further, as in the case described above, the two-way valves 19a and 19b communicating with the first and second indoor heat exchangers 17a and 17b are opened to open and close the on-off valve 23.
While the a and 23b are closed, the two-way valve 19c communicating with the third indoor heat exchanger 17c is closed and the on-off valve 23c is opened. When the flow direction of the refrigerant flowing through is directed in the direction of the dashed arrow in FIG. 1, the above case is reversed, and the first and second indoor heat exchangers 17a and 17b are heated and the third Indoor heat exchanger 17c
Is cooled.

That is, according to the present embodiment, each indoor heat exchanger 17a ~ 1a
The cooling operation and the heating operation can be appropriately combined for each 7c to operate in parallel, and the utilization of the multi-type air conditioner can be increased.

FIG. 2 shows an example in which the embodiment shown in FIG. 1 is applied to air conditioning of a building 30 such as a building. In the figure, first, second, and third outdoor units installed outside the building 30. The unit 31 incorporates the compressor 11 and the outdoor heat exchanger 13 shown in FIG. 1, and the outdoor heat exchanger 13 includes, for example, three indoor units 32a, 32b, 32c Refrigerant pipes 33 are connected to the inner heat exchangers 17a, 17b, 17c (see FIG. 1), and the indoor units 32a to 32c are arranged in the chambers A, B, C, respectively.

The multi-controller 24 of this embodiment is constructed in the same manner as the embodiment shown in FIG. 1, and an example of its control action is shown in FIG.

That is, as shown in FIG. 3, the multi-controller 24 first reads out the operation modes and the operation loads α, β, γ of the indoor units 32a to 32c, and, for example, the first and third indoor units 32a, 32c. The operation mode of is heating operation,
The operating loads are α and γ, and the second indoor unit 32b
It is read that the operation mode is the cooling operation and the operation load is β.

Next, the multi-controller 24 is installed in each indoor unit 32a to 32c.
The heating loads α and γ of the vehicle are compared with the cooling load β, and α + γ> β
In the case of, the switching operation of the four-way valve 12 is performed so that the entire refrigeration cycle shown in FIG.
Open / close control of each two-way valve 19a-19c and each open / close valve 23a-23c,
The opening degree of each of the second expansion devices 18a to 18c is set, and the compressor is set at a frequency according to the cooling / heating load difference (α + γ) -β.
Inverter drive 11

Therefore, according to this embodiment, the load difference (α +
Since γ) -β can be used for air conditioning operation of each indoor unit 32a to 32c, it is possible to arrange an air conditioner for each of the rooms A, B, C and perform air conditioning operation individually. As a result, the operating load can be reduced and the running cost can be reduced.

Further, according to the present embodiment, the system can be simplified and the initial cost can be reduced as compared with the case where the air conditioners are provided in the respective rooms A, B, C.

FIG. 4 shows another embodiment of the present invention. For example, the indoor heat exchanger 17a shown in FIG. 1 is incorporated into an air conditioning indoor unit 40, and the second indoor heat exchanger 17b is used as a heater. Built in the water heater 41, the third indoor heat exchanger 17c as a cooler in the water cooler 42, and the outdoor heat exchanger 13 in the room
43 is incorporated in the outdoor unit 44 installed outside, and an example of the control operation of the multi-controller 24 of this embodiment is almost the same as the above-mentioned embodiment (see FIG. 3) as shown in FIG. is there.

That is, as shown in FIG. 5, the multi-controller 24 determines the cooling operation mode of the indoor unit 40 and its operation load α.
And the operating loads β and γ of the water heater 41 and the water cooler 42, respectively, and compare the cooling and cooling loads α and γ with the heating load β, and if (α + γ) <β, 1
The switching operation of the four-way valve 12 is performed by the multi-controller 24 so that the entire refrigeration cycle shown in the figure is heated, and the two-way valves 19a to 19c and the on-off valves 23a to 23c are controlled to be opened and closed by the second controller. The opening degree of the expansion devices 18a to 18c is set, and the compressor 11 is driven by an inverter at a frequency corresponding to the cooling / heating load difference β− (α + γ).

Therefore, according to the present embodiment as well, the cooling / heating load difference β−
Since each of the indoor heat exchangers 17a to 17c can be operated by (α + γ), the running cost can be reduced.

〔The invention's effect〕

As described above, the present invention can perform a combination of cooling and heating operations in parallel for each of a plurality of indoor heat exchangers in parallel, so by providing a plurality of indoor heat exchangers in each room It is possible to perform heating / cooling operation of each room at the same time, and it is possible to reduce the initial cost compared to the conventional example, and when the cooling / heating operation is combined, the operating load is also reduced, so the running cost It can also be reduced.

[Brief description of drawings]

FIG. 1 is a refrigeration cycle diagram showing the overall configuration of an embodiment of a multi-type air conditioner according to the present invention, and FIG. 2 is an embodiment when the embodiment shown in FIG. 1 is applied to a building air conditioner. FIG. 3, FIG. 3 is a diagram showing an example of the control operation of the multi-controller of the embodiment shown in FIG. 2, and FIG. 4 is an application of the embodiment shown in FIG. 1 to a system having a water heater, a water cooler, etc. FIG. 5 is a diagram showing an example of the control operation of the multi-controller shown in FIG. 4, and FIG. 6 is a refrigeration cycle diagram of a conventional example. 11 ... Compressor, 12 ... Four-way valve, 1 ... Outdoor heat exchanger, 14 ... First throttling device, 15 ... Indoor heat exchanger circuit, 16 ... Refrigerant piping, 17a ... First Indoor heat exchanger, 1
7b: second indoor heat exchanger, 17c: third indoor heat exchanger, 18a, 18b, 18c: second expansion device, 19a, 19b, 19c
...... 2-way valve, 20 ...... Communication pipe, 21 ...... Main pipe, 22a, 22b, 22c
...... Branch pipes, 23a, 23b, 23c …… Open / close pipe, 24 …… Multi-controller.

Claims (1)

[Claims] 1. A first expansion device is connected to one end of an outdoor heat exchanger connected to a compressor via a four-way valve, and the first expansion device is connected to a second expansion device and an indoor heat exchange. In the multi-type air conditioner connecting the indoor heat exchanger circuit connecting a plurality of series circuits of the device and the two-way valve in parallel, in the middle of the refrigerant pipe connecting the outdoor heat exchanger to the four-way valve,
While connecting the main pipe part of the connecting pipe that branches into multiple limbs, connect each branch pipe end part of this connecting pipe in the middle of each series circuit between each indoor heat exchanger and each two-way valve. Each of the branch pipes is connected to each branch pipe, and an opening / closing valve is provided in each branch pipe. On the other hand, at the time of simultaneous cooling / heating operation, at least one of the plurality of indoor heat exchangers is provided with a cooling load and a heating load. By comparison, the four-way valve is switched to operate in a mode with a larger load, and a control means for controlling the compressor to operate according to the difference between the heating and cooling loads is provided. Air conditioner.