JPH05157411A - Multi-room type air conditioner - Google Patents

Abstract

PURPOSE:To stop, when the refrigerating cycle on one side goes to defrosting operation with the space heating operation being made, the room heating operation of the refrigerating cycle on the other side and improve the air conditioning capability in a single system cycle operation. CONSTITUTION:Two systems of refrigerating cycles, namely refrigerating cycle (a) constituted of a compressor 37a, indoor heat exchangers 41a, 43a, and outdoor heat exchanger 45, etc., and refrigerating cycle (b) constituted of a compressor 37b, indoor heat exchangers 41b, 43b, and outdoor heat exchanger 45, etc., are provided independently, and the outdoor heat exchangers 45 of those two systems of refrigerating cycles (a), (b) have refrigerant pipings 73a, 73b respectively for them. Heat transfer fine that are in contact with those refrigerant pipings 73a, 73b are used in common by the two systems of refrigerating cycles (a), (b) and the operations of their outdoor fans 71a, 73b are controlled simultaneously.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a multi-room air conditioner equipped with two independent refrigeration cycles.

[0002]

2. Description of the Related Art A so-called multi-room type air conditioner in which a plurality of indoor units are provided for one outdoor unit to cool or heat a plurality of rooms, for example, is provided with a plurality of outdoor units for freezing. There are cases where multiple cycles are provided. In FIG. 12, the indoor units connected to the two outdoor units 1 and 3 are the indoor unit for room A 5, the indoor unit for room B 7, and C, respectively.
An example is shown in which there are two indoor units for the room 9 and two indoor units for the D room 11. In this case, the mutual refrigeration cycle and the outdoor unit are completely separated. Therefore, the control of the outdoor units is completely different, and the outdoor fans 13 and 15 of the indoor units 1 and 3 are also controlled separately. As a method of installing the outdoor units 1 and 3 outdoors when two outdoor units are provided in this way, there is an example in which two units are arranged side by side on the same plane, as shown in FIG. FIG. 14 shows an outline of the internal structure of the outdoor unit 1 (3). In addition to the outdoor fan 13 (15), the compressor 17
(19) and the outdoor heat exchanger 21 (23) are provided. However, when a sufficient installation space cannot be secured outdoors, it is impossible to install two units side by side.

In such a case, as shown in FIG. 15 and FIG. 16, the other indoor unit 3 is stacked and arranged on the rack 25 accommodating the one outdoor unit 1, thereby reducing the space. be able to.

[0004]

[Problems to be Solved by the Invention]
In the case where the outdoor units 1 and 3 are stacked and arranged in stages, the upper indoor unit 3 is operated while both refrigeration cycles are in heating operation.
When the side cycle enters the defrosting operation, the lower side outdoor unit 1 side cycle may continue the heating operation,
In such an operating state, water droplets generated by defrosting in the upper cycle may drop on the outdoor unit 1 in the low temperature state of the lower cycle, which may cause icing.

Further, since each refrigeration cycle and each outdoor unit are completely separated from each other, when operating one system of refrigeration cycle, the outdoor heat exchanger naturally uses only one of the cycles. Therefore, it can be said that the outdoor heat exchanger of the other cycle that is stopped is not effectively used, and therefore there is room for improvement in the air conditioning capacity during one-system cycle operation. FIG. 17 shows the outdoor heat exchangers 21 and 23.
The outdoor heat exchanger 21 indicated by diagonal lines is operating, and the outdoor heat exchanger 23 is stopped. In this case, the heat transfer fins that can be effectively used are Only the inside outdoor heat exchanger 21 side is not used, and the stopped outdoor heat exchanger 23 side is not used.

Therefore, according to the present invention, when one refrigeration cycle enters the defrosting operation in the heating operation state, the heating operation of the other refrigeration cycle is stopped and the air conditioning capacity in the one-system cycle operation is improved. The purpose is to

[0007]

In order to achieve the above object, the present invention provides a refrigeration cycle including a compressor, an indoor heat exchanger, an outdoor heat exchanger, and the like, two independent systems. The refrigerant pipes in the outdoor heat exchangers of the two refrigeration cycles are alternately arranged, and the heat transfer fins contacting the refrigerant pipes are shared between the two refrigeration cycles, and The operation of each outdoor fan is controlled simultaneously.

[0008]

When the one refrigeration cycle enters the defrosting operation during the heating operation, the outdoor fan of the outdoor unit of the other refrigeration cycle stops at the same time, and the heating operation of the other refrigeration cycle stops. Further, since the respective refrigerant pipes in each of the outdoor heat exchangers of the two refrigeration cycles are alternately arranged and the heat transfer fins that are in contact with the refrigerant pipes are shared, the refrigeration that is not in operation during the one-system cycle operation is performed. A part of the heat transfer fins of the cycle can be used to improve the air conditioning capacity at this time.

[0009]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a block diagram of a refrigerating cycle in a multi-room air conditioner showing an embodiment of the present invention. In this refrigerating cycle diagram, two independent refrigerating cycles a and b are provided. The outdoor units of each of these cycles are combined in one outdoor unit 27 as shown in FIG. In this outdoor unit 27, the refrigeration cycle a
A room indoor unit 29 and B room indoor unit 31 included in
The C-chamber indoor unit 33 and the D-chamber indoor unit 35 included in the refrigeration cycle b are connected to each other.

In the refrigerating cycle configuration diagram of FIG. 1, a compressor 37 that compresses and sends out a refrigerant is included in cycles a and b.
a and 37b are provided respectively. In the following description, the constituent elements in the cycle a are denoted by a and the constituent elements in the cycle b are denoted by b, and the constituent elements in the two refrigeration cycles a and b are the same. Therefore, only the cycle a will be described here as a representative.

The main components will be described in the order in which the refrigerant flows from the compressor 37a during heating. The four-way valve 39a → an indoor heat exchanger 41a and an indoor heat exchanger 43a arranged in parallel with each other → both cycles a, The outdoor heat exchanger 45 is shared by b. The compressor 37a and the four-way valve 39a are connected to the pipe 4
The refrigerant that has been connected through 7a and has flowed out of the four-way valve 39a is pipe 49a.
And then to the two branch pipes 51a and 53a.
The indoor heat exchanger 41 is connected to the branch pipes 51a and 53a.
a and an indoor heat exchanger 43a are provided respectively, and expansion valves 55a, 57a and expansion valves 59a, 61a are respectively arranged in branch pipes 51a and 53a before and after each indoor heat exchanger 41a and indoor heat exchanger 43a. ing. Each branch pipe 51a, 53a and the outdoor heat exchanger 45 are connected by a pipe 63a, and the outdoor heat exchanger 45 and the four-way valve 39a are connected by a pipe 65.
It is connected by a.

Indoor heat exchanger 41a and indoor heat exchanger 43
a is included in the indoor unit 29 for room A and the indoor unit 31 for room B shown in FIG. 2, respectively, and includes an indoor fan 67a and an indoor fan 69a, respectively. On the other hand, the indoor heat exchanger 41b and the indoor heat exchanger 43b on the cycle b side are included in the C-chamber indoor unit 33 and the D-chamber indoor unit 35 shown in FIG. 2, respectively, and include the indoor fan 67b and the indoor fan 69b. Each has.

The external appearance of the outdoor unit 27 is shown in FIG. 3, and the schematic internal structure of the outdoor unit 27 of FIG. 3 is shown in FIG. The outdoor unit 27 is provided with two outdoor fans 71a and 71b which are arranged one above the other.
1a and 71b are controlled at the same time, and start and stop are performed at the same time. FIG. 5 shows the air flow rates of the outdoor fans 71a and 71b when only one of the refrigeration cycle a for room A and room B is operating, in comparison with the conventional example shown in FIG. 12 and subsequent figures. At this time, in the conventional example, only the outdoor fan 13 operates, and the air volume is the maximum "1" when the indoor units 5 and 7 in both the A and B rooms are operating, and "1" when only one of the indoor units 5 and 7 is operating. It becomes 1/2 ". On the other hand, in the present invention, both outdoor fans 7
1a and 71b operate at the same time, and the air volume is "1/2" each when the indoor units 29 and 31 of both A and B rooms are operating,
"1/4" when only one of the indoor units 29, 31 is operating
It becomes each.

The refrigerant pipes in the outdoor heat exchanger 45 are the refrigerant pipes 73a and 73b of the respective refrigeration cycles a and b.
Are alternately arranged in the vertical direction in FIG. The details of this piping configuration are shown in FIG. Regarding the refrigeration cycle a, a distributor 75a (not shown in FIG. 1) is provided at the inlet of the pipe 63a to the refrigerant pipe 73a. Refrigerant inlet 83a during heating operation,
The upper passage 77a, the middle passage 79a, and the lower passage 81a are connected to 85a and 87a, respectively. The refrigerant flowing into the refrigerant pipe 73a through the respective refrigerant inlets 83a, 85a, 87a repeatedly flows in the direction orthogonal to the paper surface in FIG.
The refrigerant outlets 89a, 91a, 93a during the heating operation are respectively reached. Each of these refrigerant outlets 89a, 91a, 93
The upper passage 95a, the middle passage 97a, and the lower passage 99a are connected to a, and the passages 95a, 97a, and 99a are connected to the header 101a. The header 101a is connected to the pipe 65a. The piping configuration for the refrigeration cycle b is similar to that of the refrigeration cycle a, and the reference numerals of the respective constituent elements are indicated by b.

Refrigerant piping 73a of each refrigeration cycle a, b,
73b are alternately arranged in the vertical direction as described above, but the heat transfer fins 103 are shared.

In the multi-room air conditioner thus constructed, for example, when heating operation is considered, the indoor unit 29,
Assuming that all 31, 33, and 35 are operating, it is assumed that the refrigeration cycle b first starts the defrosting operation. At this time, the four-way valve 39b switches from the heating mode shown by the solid line to the cooling mode shown by the broken line, the refrigerant flows in the direction of the broken line arrow, and the outdoor fan 71b stops. At the same time, on the refrigeration cycle a side that has not started the defrosting operation,
The outdoor fan 71a stops and the heating operation is stopped. At this time, the compressor 37a stops its operation or switches the four-way valve 39a to enter the defrosting operation as in the cycle b, but the defrosting operation is preferable. The indoor fans 67a, 69a, 67b, 69b are stopped during the defrosting operation of the refrigeration cycle b.

In this way, when the outdoor units in the two refrigeration cycles a and b are set as one outdoor unit 27 and the outdoor installation space is small, both refrigeration cycles a and b are in heating operation. In this case, one refrigeration cycle b
Even if the water droplets generated thereby adhere to the other refrigeration cycle a side, the other refrigeration cycle a stops the heating operation, so the outdoor unit portion on the other refrigeration cycle a side. It prevents the formation of ice.

Further, since the heat transfer fin 103 is shared by both the refrigerating cycles a and b, when only one of the refrigerating cycles a, for example, the refrigerating cycle a is operated (both heating and cooling may be used). As shown in FIG. 7, a part of the heat transfer fins shown by the broken line located on the refrigeration cycle b side can also be used, and the heat transfer area is increased compared to the conventional example shown in FIG. Air conditioning capacity is improved over time.

8 to 10 show another example of the refrigerant piping structure in the outdoor unit. In this embodiment, the refrigerant pipes 73a and 73b are alternately arranged in the vertical direction similarly to the above-mentioned embodiment, and the refrigerant pipes 73a and 73b are alternately arranged in the two rows of the refrigerant pipes. .. Thereby, both the refrigerant pipes 73a and 73b
The mutual arrangement is more uniform as a whole. This embodiment has the same effect as that of the above-mentioned embodiment, and since the pressure loss of the air flow during the frost formation of one refrigeration cycle is made uniform as a whole, the operating efficiency is improved as compared with the above-mentioned embodiment.

FIG. 11 shows still another example of the refrigerant piping structure in the outdoor unit. In this embodiment, the refrigerant pipes 73a and 73b of the embodiment shown in FIGS. 8 to 10 are made more uniform, and four passages, that is, distributors, are provided between the distributor 75a and the header 101a. 75a side of the upper passage 77a, Nakagami passages 79a _1, middle and lower passage 79a _2, the lower passage 81a, and the header 101a side of the upper passage 95a, Nakagami passages 97a _1,
The lower middle passage 97a ₂ and the lower passage 81a are connected to each other. Distributor 75b and header 101
Similarly between the b, 4 passageways, i.e. on passage 77b of the distributor 75b side, Nakagami passage 79b _1, middle and lower passage 79b _2, the lower passage 81b, and the header 101b side of the upper passage 95b, Nakagami passage 97b ₁ , middle lower passage 97
b ₂ and the lower passage 81 b are connected to each other.

FIG. 12 is a refrigeration cycle configuration diagram showing still another embodiment of the present invention. In this embodiment, when the two-cycle heating operation state of both refrigeration cycles a and b is switched to the one-cycle heating operation, the defrosting operation is performed for the cycle to be stopped, and then the operation is stopped. When the ambient temperature of the outdoor unit is as low as about 2 ° C, a function is added to remove the frost remaining on the outdoor heat exchanger on the stop cycle side.

Specifically, in the pipes 63a, 63b near the upstream side of the outdoor heat exchanger 45 for the refrigerant flow during the heating operation,
Defrost sensors 103a and 103b are provided, and when the 2-cycle heating operation is switched to the 1-cycle heating operation, when the evaporation temperature of the refrigerant detected by the defrost sensor on the stop cycle side is equal to or lower than the set value, the cycle on the stop side is defrosted. Drive. This set value may be equal to the temperature at which the defrosting operation is started during the heating operation, but basically, the temperature at which frost starts to adhere, that is, about 7 ° C. is preferable. Reference numerals 105a and 105
b is an accumulator. Other configurations and operations are almost the same as those of the refrigeration cycle shown in FIG. 1, and have the same effects as those of the above-mentioned respective embodiments.

Next, the specific operation peculiar to this embodiment will be described with reference to the flowchart of FIG. Here, the case where the refrigeration cycle b stops the heating operation from the state where both the refrigeration cycles a and b are in the heating operation. When both refrigeration cycles a and b are in the heating operation, the outdoor heat exchanger 45 acts as an evaporator. Therefore, when the outdoor air temperature is low (for example, 2 ° C.), the outdoor heat exchanger is not used after a lapse of time. Frost adheres to the exchanger 45, and the defrost sensors 103a and 103b
The temperature detected by will decrease.

Here, first, the refrigeration cycle b performs heating operation (step S1), and it is determined whether or not this cycle b stops heating operation (step S2), and whether the refrigeration cycle a is performing heating operation. Is determined (step S3). When the refrigeration cycle a continues the heating operation and the refrigeration cycle b sends a signal to stop the heating operation, it is determined whether the temperature detected by the defrost sensor 103b on the refrigeration cycle b side is equal to or less than the set value. Judge (step S
4). When it is less than or equal to the set value, the simple defrosting operation is performed on the refrigeration cycle b in the next step S5. In this simple defrosting operation, the outdoor fan 71b of the refrigeration cycle b and the outdoor fan 71a of the refrigeration cycle a are rotated at a low speed, the indoor fans 67b and 69b of the refrigeration cycle b are stopped, and the four-way valve 39b is left in the heating mode. , The compressor 37b is operated at a low frequency, and the expansion valves 55b, 57b, 59b and 6 are operated.
It is performed by fully opening 1b. When the preset defrosting operation time has elapsed (step S
6) The operation of the refrigeration cycle b to which the operation stop signal has been sent is stopped (step S7).

As described above, by performing the defrosting operation on the refrigeration cycle b to be stopped before the operation is stopped, even if the refrigeration cycle a continuously operating lowers the temperature of the outdoor heat exchanger 45. As a result, frost does not remain on the refrigeration cycle b.

Although the simple defrosting operation is sufficient for removing frost from the refrigeration cycle b, a normal defrosting operation may be used, and the criterion for stopping the operation of the refrigeration cycle b after the defrosting operation is: The temperature detected by the defrost sensor 103b may exceed the preset defrost end temperature.

[0028]

As described above, according to the present invention, when one refrigerating cycle enters the defrosting operation during the heating operation, the outdoor fan of the outdoor unit of the other refrigerating cycle stops at the same time. Since the heating operation of the other refrigeration cycle is stopped, it is possible to avoid a situation in which water droplets generated by defrost dripping on the outdoor unit portion on the other refrigeration cycle side and forming ice. Further, since the refrigerant pipes in each of the outdoor heat exchangers of the two refrigeration cycles are alternately arranged and the heat transfer fins that come into contact with the refrigerant pipes are shared,
During the system cycle operation, a part of the heat transfer fins of the cycle that is not in operation can be used, and the air conditioning capacity at this time can be improved.

[Brief description of drawings]

FIG. 1 is a refrigeration cycle configuration diagram showing an embodiment of the present invention.

FIG. 2 is an overall configuration diagram of a multi-room air conditioner including the refrigeration cycle of FIG.

FIG. 3 is an external view of an outdoor unit of the multi-room air conditioner.

FIG. 4 is a side sectional view showing the internal structure of the outdoor unit of FIG.

FIG. 5 is an explanatory view showing the air volume of the outdoor fan in the outdoor unit of FIG. 3 in comparison with a conventional example.

FIG. 6 is a refrigerant pipe configuration diagram in an outdoor unit of the multi-room air conditioner.

FIG. 7 is an explanatory diagram showing an increase in heat transfer area of heat transfer fins during one-system cycle operation in the outdoor unit.

FIG. 8 is a side sectional view showing the internal structure of the outdoor unit showing another embodiment of the present invention.

9 is a refrigerant pipe configuration diagram in the outdoor unit of FIG.

10 is an explanatory diagram showing an increase in heat transfer area of heat transfer fins during one-system cycle operation in the outdoor unit of FIG. 8. FIG.

FIG. 11 is a refrigerant pipe configuration diagram of an outdoor unit showing still another embodiment of the present invention.

FIG. 12 is a refrigeration cycle configuration diagram showing still another embodiment of the present invention.

13 is a flowchart showing the operation of the refrigeration cycle of FIG.

FIG. 14 is an overall configuration diagram of a multi-room air conditioner showing a conventional example.

FIG. 15 is a front view showing an installation example of two outdoor units according to a conventional example.

16 is a side sectional view showing the internal structure of the outdoor unit of FIG.

FIG. 17 is a front view showing an installation example of two outdoor units according to another conventional example.

FIG. 18 is a side sectional view showing the internal structure of the outdoor unit of FIG. 17.

FIG. 19 is an explanatory diagram showing a heat transfer area of heat transfer fins during one-system cycle operation of the outdoor unit of FIG. 17.

[Explanation of symbols]

 37a, 37b Compressor 41a, 43a, 41b, 43b Indoor heat exchanger 45 Outdoor heat exchanger 67a, 69a, 67b, 69b Indoor fan 71a, 71b Outdoor fan 73a, 73b Refrigerant piping 103 Heat transfer fin a, b Refrigeration cycle

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Koichi Yamaguchi, 8 Shinsita-cho, Isogo-ku, Yokohama-shi, Kanagawa Kanagawa Prefecture, Ltd. In the Institute for Living Space Systems Technology, Ltd. (72) Yasunori Oyabu 8 Shinsugita-cho, Isogo-ku, Yokohama, Kanagawa Address Incorporated company Toshiba Living Space Systems Engineering Laboratory (72) Inventor Takashi Doi 8 Shinsita-cho, Isogo-ku, Yokohama, Kanagawa Prefecture Incorporated Toshiba Living Space Systems Engineering Laboratory (72) Inventor Masaki Imamura Shimbashi, Minato-ku, Tokyo 3-3-9 Toshiba Abu E. Co., Ltd.

Claims (1)

[Claims] 1. A refrigeration cycle including a compressor, an indoor heat exchanger, an outdoor heat exchanger, and the like is provided independently of each other in two systems, and each of the two systems of the outdoor heat exchangers of the refrigeration cycle is provided. The respective refrigerant pipes are alternately arranged, the heat transfer fins that come into contact with the respective refrigerant pipes are shared between the two refrigeration cycles, and the operations of the respective outdoor fans are controlled simultaneously. Multi-room type air conditioner.