JP3138154B2 - Air conditioner - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an air conditioner having two heat source side heat exchangers (for example, an air-cooled heat exchanger and a water-cooled heat exchanger).

[0002]

2. Description of the Related Art One outdoor unit provided with a compressor and an air-cooled heat exchanger and another outdoor unit provided with a compressor and a water-cooled heat exchanger are connected to three inter-unit pipes (liquid pipes). Japanese Patent Application No. 4-346637 discloses a system in which cooling and heating can be performed at the same time by connecting with a high-pressure gas pipe and a low-pressure gas pipe.

[0003] This proposal proposes that, for example, when the outside air temperature decreases during a heating operation and one of the outdoor units having an air-cooled heat exchanger cannot pump up enough heat, the operation of this one outdoor unit is stopped. The other outdoor unit having the water-cooled heat exchanger is stopped and operated. As a result, as a heating operation from an air heat source to a water heat source,
This is to maintain the heating capacity.

[0004]

Here, when the operation of one outdoor unit is stopped and the other outdoor unit is operated, the operation of the compressor in the one outdoor unit is also stopped. That is, unless one of the two outdoor units is operated at the same time, one of the compressors and the heat exchanger is in a stopped state, so that it is hard to say that each device is being used effectively.

[0005] The present invention effectively reduces the cost and efficiently defrosts each device (compressor and various heat exchangers) connected to the three unit pipes. It is an object of the present invention to provide an air conditioner capable of simultaneous cooling and heating operations.

[0006]

According to a first aspect of the present invention, a heat source side heat exchange group and a utilization side heat exchange group are connected by a liquid pipe, a high pressure gas pipe, and a low pressure gas pipe. In the air conditioner, the heat source side heat exchange group has a compression circuit, a main heat source circuit, and an auxiliary heat source circuit. In this compression circuit, a suction pipe is connected to the low-pressure gas pipe, and a discharge pipe is connected to the high-pressure gas pipe. A first compressor connected to the main heat source circuit, a main heat exchanger is disposed, a main expansion valve for heating is disposed at one end and connected to the liquid pipe, and the other end is branched and In the branch pipe, one open / close valve is arranged and connected to a high-pressure gas pipe, and the other branch pipe is provided with another open / close valve and connected to a low-pressure gas pipe. The main heat exchange circuit is provided in the auxiliary heat source circuit. An auxiliary heat exchanger that is less frost-resistant than the heat exchanger is located at one end. A secondary expansion valve is disposed and connected to the liquid pipe, the other end is branched and one branch pipe is provided with a second compressor and connected to the high pressure gas pipe and the other branch pipe is checked. A valve is arranged and connected to a low-pressure gas pipe, and the opening of the main expansion valve for heating is controlled when the main heat exchanger is operated as an evaporator, and the opening is substantially fully opened when the main heat exchanger is operated as a condenser. Set, the one on-off valve is closed when the main heat exchanger is operated as an evaporator and is opened when the main heat exchanger is operated as a condenser, and the other on-off valve is opened when the main heat exchanger is operated as an evaporator. Closed when acting as a condenser, the opening of the auxiliary heating valve is controlled when the auxiliary heat exchanger is operated, and the check valve is a refrigerant when the auxiliary heat exchanger is operated. To the low pressure gas pipe It is obtained so as to prevent being Komu.

According to a second aspect, in the first aspect, the auxiliary heat exchanger of the auxiliary heat source circuit is set to have a higher heat source side temperature than the main heat exchanger.

[0008]

According to the first aspect, the compression circuit, the main heat source circuit, and the auxiliary heat source circuit are operated as required. On this occasion,
The auxiliary heat exchanger of the auxiliary heat source circuit is less likely to adhere to frost than the main heat exchanger of the main circuit, and the main heat exchanger and the auxiliary heat exchanger operate (act) at the same time. The operation and operation of the compressor and the main heat exchanger are independently controlled.

According to the second invention, in the air conditioner of the first invention, the temperature of the auxiliary heat exchanger of the auxiliary heat source circuit is set higher than that of the main heat exchanger on the heat source side. The action of the heat exchanger is changed.

[0010]

1, an air conditioner 1 comprises a heat source side heat exchange group A, a use side heat exchange group B, and an inter-unit pipe 2 connecting both groups. The inter-unit pipe 2 includes a liquid pipe 3, a high-pressure gas pipe 4, and a low-pressure gas pipe 5. On the other hand, the use-side heat exchange group B includes a plurality of indoor units 6, 7 connected in parallel with the inter-unit piping 2.
, And each has a built-in indoor heat exchanger 8. One end of the indoor heat exchanger 8 is connected to the liquid pipe 3 via a first control valve (for example, “electronic control valve” or “electric control valve”) 9 whose opening degree can be adjusted. . The degree of opening of the first control valve 9 is adjusted when the indoor units 6 and 7 are in the cooling operation, and the first control valve 9 is almost fully opened in the heating operation. The other end of the indoor heat exchanger 8 is branched into two, and the high-pressure side branch pipe 10 is connected to the high-pressure gas pipe 4 via a first on-off valve 11.
The low-pressure side branch pipes 12 are connected to the low-pressure gas pipes 5 via second on-off valves 13, respectively.

The heat source side heat exchange group A is one outdoor unit 14 in this embodiment. The outdoor unit 14 includes a compression circuit 15, a main heat source side circuit 16, and an auxiliary heat source side circuit 1.
7 is comprised. A first compressor 18 is arranged in the compression circuit 15, and a discharge pipe 19 of the first compressor 18 is connected to the high-pressure gas pipe 4, and a suction pipe 20 is connected to the low-pressure gas pipe 5.

The main heat source side circuit 16 has an air cooling type (air heat source).
A heat exchanger 21 is provided, and one end of the air-cooled heat exchanger 21 is provided with a second control valve (for example, an “electronic control valve” or an “electric control valve”) 22 whose opening can be adjusted. It is connected to the liquid pipe 3 through the intermediary of the liquid. The other end of the air-cooled heat exchanger 21 is branched into two, and the high-pressure side branch pipe 23 is connected to the high-pressure gas pipe 4 via the third on-off valve 24 and the low-pressure side branch pipe 2.
Numerals 5 are respectively connected to the low-pressure gas pipe 5 via a fourth on-off valve 26.

A water-cooled (water heat source) heat exchanger 27 is disposed in the auxiliary heat source side circuit 17.
One end of 7 is connected to the liquid pipe 3 via a third control valve (for example, “electronic control valve” or “electric control valve”) 28 whose opening degree can be adjusted. The other end of the water-cooled heat exchanger 27 is branched into two, and one branch pipe 29 is connected to the second branch.
The high-pressure gas pipe 4 is connected to the low-pressure gas pipe 5 via a check valve 32, while the branch pipe 31 is connected to the low-pressure gas pipe 5 via a check valve 32.

In other words, the components of the auxiliary heat source side circuit 17 are mainly described as follows. The water-cooled heat exchanger 27 is a heat exchanger that is less susceptible to frost than the air-cooled heat exchanger 21 provided in the main heat source side circuit 16.
7 has a different heat source side temperature. Also, the second compressor 3
At 0, the discharge pipe 33 is connected to the high-pressure gas pipe 4 and the suction pipe 34 is connected to the low-pressure gas pipe 5.

In the air conditioner having such a configuration, the indoor units 6 and 7 can be freely selected from a cooling operation and a heating operation. That is, the indoor unit 6
When the cooling operation is performed, the second on-off valve 13 is opened. As a result, the liquid refrigerant from the liquid pipe 3 flows into the indoor heat exchanger 8, the indoor heat exchanger 8 performs an evaporating action, and the indoor unit 8 performs a cooling operation.

On the other hand, when performing the heating operation of the indoor unit 7, the first on-off valve 11 is opened. Thereby, the gas refrigerant from the high-pressure gas pipe 4 flows into the indoor heat exchanger 8,
The indoor heat exchanger 8 performs a condensing operation to form the indoor unit 7.
Performs the heating operation. Here, the operation state of the outdoor unit 14 is changed according to the cooling load and the heating load of each of the indoor units 6 and 7 described above. That is, when the cooling load is larger than the heating load, the cooling-main operation is performed. In this case, the refrigerant flows as indicated by the solid arrows in FIG. During the cooling main operation, the outdoor heat exchanger 21 acts as a condenser, the indoor heat exchanger 8 of the indoor unit 7 during the heating operation acts as a condenser, and the indoor heat exchanger 8 of the indoor unit 6 during the cooling operation.
Acts as an evaporator. Then, the refrigerant in the low-pressure gas pipe 4 flows into the two compressors 18 and 30 in parallel.

When the heating load is larger than the cooling load, the heating-main operation is performed. Here, the heating main operation is
"Air heat source operation" that uses only air-cooled heat exchangers, and "Air heat source" that uses air-cooled heat exchangers and water-cooled heat exchangers when heat cannot be sufficiently pumped by this air heat source operation alone + Water heat source "operation. The open / closed state of various valves during any operation is as shown in FIG.

During the operation of the air heat source, the refrigerant from the liquid pipe 3 is
By closing the third control valve 28, as shown by a dashed arrow, the gas flows only into the air-cooled heat exchanger 21. Then, the air-cooled heat exchanger 21 acts as an evaporator, and thereafter the refrigerant is co-flowed to the two compressors 18 and 30 via the low-pressure gas pipe 5. That is, during the operation of the air heat source, the third control valve 28 is closed by the water-cooled heat exchanger 27 as described above.
The refrigerant in the low-pressure gas pipe 5 flows into the second compressor 30 when the check valve 32 is opened. Therefore, in the auxiliary heat source side circuit 17, the second compressor 30 is operated although the water-cooled heat exchanger 27 is not operating.

On the other hand, during the “air heat source + water heat source” operation, the refrigerant in the liquid pipe 3 flows into the second compressor 30 via the water-cooled heat exchanger 27 by controlling the opening of the third control valve 28. At the same time, it also flows into the air-cooled heat exchanger 21 via the second control valve 22 (see the dashed line arrow). Here, since the air-cooled type generally has a heat source of an outside air temperature of 0 ° C., and the water-cooled type has a water temperature of about 15 ° C., the pressure of the refrigerant flowing out of the water-cooled outdoor heat exchanger 27 is equal to the air-cooled outdoor heat exchanger. It becomes higher than the pressure of the refrigerant flowing out of the refrigerant gas 21 (the refrigerant pressure in the branch pipe of the low-pressure gas pipe 5). For this reason, at the time of low outside temperature at which the water-cooled heat exchanger 27 must be used, the check valve 32 is always closed, and the refrigerant flowing out of the water-cooled outdoor heat exchanger 27 and the low-pressure gas The refrigerant flowing out of the pipe 5 does not mix on the suction side of the second compressor 30.

During the defrosting operation for melting the frost generated in the air-cooled heat exchanger 21, various valves are set in the state shown in FIG. 3 to operate the two compressors 18, 30. Thereby, as shown by the solid line arrow in FIG. 4, a part of the refrigerant in the high-pressure gas pipe 4 flows into the air-cooled heat exchanger 21 via the third on-off valve 24, where defrosting is performed. Thereafter, the refrigerant is guided to the liquid pipe 3 and flows into the water-cooled heat exchanger. Also at this time, the refrigerant discharged from the compressor 18 flows to the indoor unit 6.

Regardless of whether the operation of the indoor units 6 and 7 is set to the cooling or heating state, the outdoor unit is operated in the cooling main operation, the heating main operation by the air heat source, the air heat source and the water in accordance with the state and the outside air temperature. The heating-main operation using the heat source is selected, and the refrigeration equipment is used according to the operation. That is, in the heating main operation using the air heat source, one air-cooled heat exchanger 21 and two compressors 18 and 30 are operated. On the other hand, during the heating main operation using the air heat source and the water heat source, the pair of the air-cooled heat exchanger 21 and the first compressor 18 and the pair of the water-cooled heat exchanger 27 and the second compressor 30 are connected. Is working.

In this embodiment, the water-cooled heat exchanger 27 and the air-cooled heat exchanger 30 are used, respectively. However, the present invention is not limited to these, but uses a heat source having a different heat source temperature. Any heat exchanger is acceptable. That is, both of the two outdoor heat exchangers 13 may be “water-cooled heat exchangers”. In this case, the temperature of the water supplied from the boiler to the water-cooled heat exchanger is changed.

FIG. 5 shows another embodiment of the first invention.
The difference from the embodiment of FIG. 1 is that one main heat source circuit 51 is added to the outdoor unit 50. Thus, during the heating-main operation using the air heat source, two air-cooled heat exchangers 21 and 52 and two compressors 18 and 30 are used (see solid arrows), and the capacity of the compressors 18 and 30 and the air-cooled type are used. The balance with the capacity of the heat exchangers 21 and 52 is better than that of the embodiment of FIG. 1, and efficient operation can be performed. If necessary, by stopping the operation (operation) of one compressor, one air-cooled heat exchanger, or both, the air conditioning capacity can be adjusted to the load.

Further, during the heating-main operation by "air heat source + water heat source", the refrigerant pressure Ps at the outlet side of the water-cooled heat exchanger 27 becomes higher than the refrigerant pressure Ph in the branch pipe 5 of the low-pressure gas pipe 4 (described above). Therefore, the check valve 32 is closed. As a result, the first compressor 18 receives the two
Refrigerant flows from the two air-cooled heat exchangers 21 and 52,
The refrigerant from the water-cooled heat exchanger 27 flows into the second compressor 30 as shown by a two-dot chain line arrow. Therefore, when viewed from the first compressor 18, the two air-cooled heat exchangers 21 and 52 become so-called "heat sources", and each air-cooled heat exchanger 21 and 52 has a different air-cooled heat exchanger as compared with the case where one air-cooled heat exchanger serves as a heat source. The evaporating temperature of the heat exchanger becomes high, and as a result, these air-cooled heat exchangers 21 and 5
2 can be hardly frosted. This also
When frost is formed on the air-cooled heat exchangers 21 and 52, the following valve operation is performed to remove defrost by the heat source from the water-cooled heat exchanger 27, and to perform air-cooling without frost formation. Heating can be continued with the heat source from the heat exchanger to minimize the decrease in indoor temperature.

That is, when frost forms on one of the air-cooled heat exchangers 52, the third on-off valve 24 connected to the heat exchanger 52 is opened and the fourth on-off valve 26 is closed, whereby the compressor is opened. Some of the refrigerant discharged from 30 is connected to the high-pressure gas pipe 4,
The air flows into the air-cooled heat exchanger 52 in the frosted state via the third on-off valve 24 to perform a defrosting operation. After that, it flows into the water-cooled heat exchanger 27 via the liquid pipe 3. Also in this case, since the refrigerant in the high-pressure gas pipe 4 flows into each indoor unit, the decrease in the heating capacity is small.

FIG. 6 shows a second embodiment of the present invention. The difference from FIG. 5 is that one outdoor unit is divided into two and connected in parallel. That is, the first outdoor unit 6
1 includes a compression circuit 15 and one main heat source side circuit 63, and the second outdoor unit 62 includes a second main heat source side circuit 64 and an auxiliary heat source side circuit 17. . Therefore, in a (warm) district where sufficient heating capacity can be obtained with only the first outdoor unit 61, the second
It is not necessary to increase the number of outdoor units 62, and the combination of the outdoor units 61 and 62 applied to the area is possible.

In addition, during the simultaneous operation of the two outdoor units 62, in other words, during the heating-main operation using the "air heat source + water heat source", the check valve 32 is closed (described above), and the air-cooled heat exchanger 21, 52 can be made hard to frost. Further, in the second outdoor unit 62, the operation of the auxiliary heat source side circuit 17 is stopped during the heating main operation by the air heat source, but the other main heat source side circuit 64 is operating. In other words, in the second outdoor unit 62, the operation of the second compressor 30 and the water-cooled heat exchanger 27 is stopped, but the operation of the air-cooled heat exchanger 52 is performed. The refrigeration equipment in the second outdoor unit 62 can be effectively utilized individually according to the load.

[0028]

According to the first aspect of the present invention, in an air conditioner connected by three unit pipes (a high-pressure gas pipe, a low-pressure gas pipe, and a liquid pipe), each device (compression) connected to the unit pipes is connected. , A water-cooled heat exchanger, and an air-cooled heat exchanger) can be used effectively to reduce costs and prevent the air-cooled heat exchanger from being frosted. Even if frost is formed, efficient defrosting can be performed.

According to the second invention, in the air conditioner of the first invention, the temperature of the auxiliary heat exchanger of the auxiliary heat source circuit is set to be higher than that of the main heat exchanger on the heat source side. The operation according to the load can be performed by changing the action of the heat exchanger.

[Brief description of the drawings]

FIG. 1 is a refrigerant circuit diagram of an air conditioner of a first invention.

FIG. 2 is an explanatory diagram showing an open / closed state of each valve of the outdoor unit shown in FIG.

FIG. 3 is an explanatory diagram showing an open / closed state of each valve of each indoor unit shown in FIG. 1;

4 is a refrigerant circuit diagram illustrating a flow of a refrigerant during a defrosting operation of the air-conditioning apparatus illustrated in FIG.

FIG. 5 is a refrigerant circuit diagram showing a different embodiment of the first invention.

FIG. 6 is a refrigerant circuit diagram showing the second invention.

[Description of Signs] 3 Liquid pipe 4 High pressure gas pipe 5 Low pressure gas pipe 16 Main heat source (side) circuit 17 Auxiliary heat source (side) circuit 18 First compressor 21, 27 Heat exchanger 30 Second compressor 61, 62 Outdoor Unit A Heat source side heat exchange group B User side heat exchange group

──────────────────────────────────────────────────続 き Continued on the front page (58) Fields surveyed (Int. Cl. ⁷ , DB name) F25B 29/00 361 F25B 13/00 104 F25B 27/00 F25B 47/02 520 F25B 30/06

Claims (2)

(57) [Claims] 1. An air conditioner in which a heat source side heat exchange group and a use side heat exchange group are connected by a liquid pipe, a high pressure gas pipe and a low pressure gas pipe, wherein the heat source side heat exchange group comprises a compression circuit and a main heat source circuit. And an auxiliary heat source circuit. In this compression circuit, a suction pipe has a discharge pipe connected to the low-pressure gas pipe.
A first compressor connected to the high-pressure gas pipe , a main heat exchanger is disposed in the main heat source circuit, and one end thereof
Has a main expansion valve for heating and is connected to the liquid pipe.
The other end is branched and one branch pipe has one open / close valve
Is connected to the high pressure gas pipe and the other
The other on-off valve is located in the manifold and is connected to the low-pressure gas pipe.
The auxiliary heat source circuit is less frosty than the main heat exchanger.
An auxiliary heat exchanger is located at one end of the auxiliary heat exchanger.
A tension valve is arranged and connected to the liquid pipe, and the other end is
A second compressor is arranged in one branch pipe and a high
Check valve connected to the pressurized gas pipe and the other branch pipe
And connected to a low-pressure gas pipe, the main expansion valve for heating uses the main heat exchanger as an evaporator.
When operated, its opening is controlled and acts as a condenser.
The opening degree is set to substantially full open when the valve is turned on, and the one on-off valve acts on the main heat exchanger as an evaporator.
The other on-off valve acts as the evaporator while the other on-off valve acts as the evaporator.
Opening when closing and closing when acting as a condenser, the auxiliary expansion valve for heating activates the auxiliary heat exchanger.
When the auxiliary heat exchanger is operated, the refrigerant is
An air conditioner characterized by being prevented from flowing into the low-pressure gas pipe . 2. The air conditioner according to claim 1, wherein the temperature of the auxiliary heat exchanger of the auxiliary heat source circuit is set higher than that of the main heat exchanger.