JPH0355757B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an air conditioner, specifically a compressor,
Relating to an air conditioner equipped with two or more refrigeration circuits in which a four-way switching valve, an air-to-air heat source side heat exchanger, and a user-side heat exchanger are systematically piped, and capable of heating and cooling by switching the four-way switching valve. .

Generally, in an air conditioner configured as described above, when the heat source side heat exchanger is frosted during heating, defrosting is performed by reversing the refrigeration cycle, that is, the cooling cycle, and absorbing the heat from the user side heat exchanger. This is done either as a heat source or by attaching an electric heater to the heat exchanger on the heat source side and energizing the heater, but with the reverse cycle method, there is a problem that the indoor side where heating is performed is cooled and cold draft occurs. In addition, the electric heater method requires an extra electric heater and consumes extra power during defrosting, which is uneconomical.

Therefore, in order to solve problems that are more difficult than before,
As shown in Japanese Unexamined Patent Publication No. 56-137054, and as shown in FIG.
Auxiliary heat exchangers B, B are attached to the auxiliary heat exchangers B, B, respectively, and the inlet sides of these auxiliary heat exchangers B, B are connected to high pressure liquid pipes C, C in the refrigeration circuit of other systems, on-off valves D, D, and expansion mechanism E. , E, and the outlet side is connected to the low pressure gas pipe G in the refrigeration circuit of another system, and is attached to the heat source side heat exchanger A of the other system during defrosting. It has been proposed that the defrost heat source is taken in from the outdoor air using the auxiliary heat exchanger B, and the heat source side heat exchanger A is defrosted. In addition, in Fig. 3, H and H are compressors, I and I are four-way switching valves,
J and J are user-side heat exchangers, and K and K are liquid receivers.

However, according to this conventional device, during defrosting,
Since this defrost heat source is taken from outdoor air, sufficient heat cannot be obtained, resulting in a problem that the defrost time becomes long.As a result, the refrigeration circuit of the system that performs defrost cannot perform heating, so it takes a long time. I had a problem with the interior getting cold when defrosting.

An object of the present invention is to use a part of the condensed heat of other systems in heating operation during defrosting as a defrosting heat source, so that defrosting can be performed in a short time.

In the present invention, between one switching port of the four-way switching valves 11, 12 in each refrigerant circuit 1, 2 and the user-side heat exchangers 14, 24, it becomes a low pressure gas pipe during cooling and a high pressure gas pipe during heating. gas pipes 16a, 26
A is connected to the gas pipes 16a and 26a of each of the refrigerant circuits 1 and 2, and a defrost heat exchanger 3 that is capable of mutually exchanging heat is interposed between the gas pipes 16a and 26a of each refrigerant circuit. High pressure liquid pipes 16b, 26b and the gas pipes 16a, 26a in 1, 2
Bypass pipes 4, 5 bypassing the utilization side heat exchangers 14, 24 of each of these refrigerant circuits 1, 2.
is provided, and when the heat source side heat exchangers 12 and 22 are defrosted, the refrigerant circuit 1 or 2 of the heat source side heat exchanger 12 or 22 to be defrosted is set to the cooling cycle by switching the four-way switching valve 11 or 21, and the other is set to the cooling cycle. As a heating cycle, the bypass pipe 4 or 5 in the refrigerant circuit 1 or 2 which is the cooling cycle is opened, the bypass pipe 5 or 4 in the refrigerant circuit 2 or 1 of the heating cycle is closed, and the bypass pipe 5 or 4 in the refrigerant circuit 2 or 1 of the heating cycle is closed. Gas pipe 26a or 16a
By alternately defrosting the heat source side heat exchanger 12 or 22 in the refrigerant circuit 1 or 2 which is a cooling cycle using the high pressure gas flowing through the cooling cycle as the heat source, defrosting can be carried out in a short time using the condensation heat as the defrost heat source. I made it possible to do so.

Next, an embodiment of the present invention will be described based on FIG.

In FIG. 1, 1 and 2 are independent refrigerant circuits of different systems, and these two refrigerant circuits 1 and 2 of the first and second systems are connected to the compressor 1, respectively.
0, 20, four-way switching valves 11, 21, heat source side heat exchangers 12, 22, liquid receivers 13, 23, user side heat exchangers 14, 24, and accumulators 15, 25, and these devices are connected to the refrigerant. The four-way switching valves 11 and 2 are systematically connected by pipes 16 and 26.
1, the cooling cycle shown by the solid line arrow in FIG. 1 and the heating cycle shown by the dotted line arrow in FIG. 1 are independently formed.

Note that 17 and 27 are cooling expansion valves in which check valves 17a and 27a are arranged in parallel, and 18 and 28 are check valves 18
It is a heating expansion valve in which a and 28a are arranged in parallel, and 1
9 and 29 are closing valves.

Moreover, the heat source side heat exchangers 12 and 22 are attached with outdoor fans F ₁ and F ₂ as air-type. Further, the user-side heat exchangers 14 and 24 may be of a water type or an air type, but if they are of an air type, indoor fans F ₃ and F ₄ are attached.

What is shown in the drawing is an air conditioner configured as described above, in which the gas pipes 16a and 26a of the refrigerant circuits 1 and 2, which serve as low-pressure gas pipes during cooling and high-pressure gas pipes during heating, mutually exchange heat. In addition to interposing a defrosting heat exchanger 3, high pressure liquid pipes 16b and 26 in each refrigerant circuit 1 and 2 are installed.
Bypass pipes 4 and 5 that bypass the use-side heat exchangers 14 and 24 are connected between the gas pipes 16a and 26a, and a solenoid valve 41 that opens during defrosting is connected to the bypass pipes 4 and 5. , 51, capillary reach tubes 42, 52, and check valves 43, 53, the bypass pipe 4 in one refrigerant circuit 1 or 2 when the heat source side heat exchangers 12, 22 are frosted. or 5, and keep the solenoid valve 51 or 41 of the bypass pipe 5 or 4 in the refrigerant circuit 2 or 1 of the other system closed, and the gas pipe 26a or 16a of the other system.
The heat source side heat exchanger 12 in the refrigerant circuit 1 or 2 of one system uses high pressure gas flowing through as a heat source.
Alternatively, 22 defrosts are performed alternately.

Incidentally, electromagnetic valves 44, 54 which are closed during defrosting are interposed on the user side heat exchangers 14, 24 with respect to the connection positions of the bypass pipes 4, 5 in the high pressure liquid pipes 16a, 26a.

Further, the defrosting heat exchanger 3 includes one of the gas pipes 16a and 26a, as shown in FIG. 2a.
It is also possible to make the parts close to each other or in contact with each other to form a soldered part X, and to cover this soldered part with a heat insulating material Y, but preferably, as shown in FIG. The tubes 31 and the heat exchange tubes 32 of the second system are arranged adjacently or alternately, and a plurality of common fins 33 are inserted between the heat exchange tubes 31 and 32, so that the heat exchange tubes 31 of the respective systems, 32 is the gas pipe 16a, 26 in each refrigerant circuit 1, 2.
It is configured by connecting each to a.

In the above configuration, by locating the four-way switching valves 11 and 21 as shown by the solid lines in FIG. 1 and driving the compressors 10 and 20 of each system, A cooling cycle is formed, and the user-side heat exchangers 14 and 24 in the refrigerant circuits 1 and 2 of each system can perform cooling, respectively. By driving the compressors 10 and 20 of each system as shown by the dotted lines, a heating cycle is formed as shown by the dotted line arrows in FIG. It can be done.

Note that during cooling and heating performed as described above, low-pressure gas flows through the defrosting heat exchanger 3 installed in the gas pipes 16a and 26a during cooling, and high-pressure gas flows during heating.
There is almost no mutual heat exchange between the two, and even if there is some heat exchange, it is only a change in sensible heat and does not cause any problems in cooling or heating.

Furthermore, when performing heating as described above, the heat source side heat exchangers 12 and 22 will each become frosted.

Defrosting at the time of frosting is performed for each system. For example, when defrosting the heat exchanger 12 provided in the refrigerant circuit 1 of the first system, the four-way switching valve 11 of the first system is defrosted. , the four-way switching valve 21 of the second system is located on the heating side shown in dotted lines in FIG. 1, and the solenoid valve of the bypass pipe 4 41 is opened, the solenoid valve 51 of the bypass pipe 5 of the second system remains closed, and
Solenoid valve 44 interposed in the high pressure liquid pipe 16b of the first system
This is done by closing the .

Incidentally, the first system fan F1 is stopped, and the second system fan _F1 is stopped.
The system fan F ₂ allows the operation to continue,
Further, the solenoid valve 54 installed in the high pressure liquid pipe 26b of the second system is kept open.

Therefore, the refrigerant circuit 1 of the first system becomes a cooling cycle, and the high temperature and high pressure gas refrigerant discharged from the compressor 10 flows to the heat source side heat exchanger 12, and can be defrosted by its latent heat of condensation. .

The liquid refrigerant condensed in the heat source side heat exchanger 12 does not flow to the user side heat exchanger 14 of the first system due to the closure of the solenoid valve 44, and the entire amount passes through the bypass pipe 4. The gas flows from the gas pipe 16a in the refrigerant circuit 1 of the first system to the defrost heat exchanger 3, and the second gas flows through the heat exchanger 3.
It exchanges heat with the high-pressure gas in the system, evaporates, and returns to the compressor 10 in the first system.

The defrosting performed as described above does not use the warm air in the room or the heat stored in the heat exchanger 14 on the user side as a heat source, but uses the heat of condensation of the high-pressure gas in the refrigerant circuit 2 of the second system. This is done by incorporating the heat source into the defrost heat source.
The room heated by the first system that performs defrost does not cool down or create a cold draft, and there is no need to use an electric heater, so defrosting can be performed economically. Since the condensation heat from other systems is used instead of using outdoor air as the defrost heat source, defrosting can be performed in a short time. Although the condensation heat from other systems is used, the entire amount is not taken into the defrost heat source.
Heating from other systems can continue.

Also, after the defrosting of the first system is completed as described above, by reversing the above operation, the defrosting of the second system is completed.
The heat source side heat exchanger 22 of the system is defrosted, and the heat source side heat exchangers 12 and 22 of the first and second systems are defrosted alternately.

In the embodiment shown in the drawings, a solenoid valve 4 is installed in the bypass pipes 4 and 5 and the high pressure liquid pipes 16b and 26b.
1, 51 and 44, 54, a three-way solenoid valve is used to connect the high pressure liquid pipe 16 of the bypass pipes 4, 5.
It may be interposed at the connection position to b, 26b.

Further, although the capillary reach tubes 42 and 52 are provided in the bypass pipes 4 and 5, an expansion valve may be used, and an expansion mechanism may be assembled in the solenoid valves 41 and 51 without using the capillary reach tubes 42 and 52. It can be crowded.

Furthermore, the check valves 43, 53 interposed in the bypass pipes 4, 5 are not necessarily required.

In addition, in the embodiment shown in the drawings, the indoor unit and outdoor unit are separated as shown by the two-dot chain line, but they may be in the form of a single unit, or if they are separated, the indoor unit may be In each system, not only one unit but also a plurality of units may be connected.

As described above, the present invention provides the four-way switching valve 1 in each of the two or more independent refrigerant circuits 1 and 2.
One switching port of 1, 12 and user side heat exchanger 1
Gas pipes 16a and 24 are connected between the gas pipes 16a and 24, and serve as low-pressure gas pipes during cooling and serve as high-pressure gas pipes during heating.
6a is interposed with a defrost heat exchanger 3 capable of mutual heat exchange, and each of the refrigerant circuits 1,
2 between the high pressure liquid pipes 16b, 26b and the gas pipes 16a, 26a, each refrigerant circuit 1,
Bypass pipes 4 and 5 bypassing the user-side heat exchangers 14 and 24 of 2 are provided, and the heat source-side heat exchanger 1
2 and 22, the refrigerant circuit 1 or 2 of the heat source side heat exchanger 12 or 22 to be defrosted is set to the cooling cycle by switching the four-way switching valve 11 or 21, and the other is set to the heating cycle, which is set to the cooling cycle. Bypass pipe 4 or 5 in refrigerant circuit 1 or 2 is opened, and refrigerant circuit 2 of the heating cycle is opened.
Alternatively, the bypass pipe 5 or 4 in 1 is closed, and the high pressure gas flowing through the gas pipe 26a or 16a in the refrigerant circuit 2 or 1 of the heating cycle is used as a heat source to create a cooling cycle, and the heat source side heat exchange in the refrigerant circuit 1 or 2 is performed. Since the defrosting of the heat exchangers 12 or 22 is performed alternately, when one of the heat source side heat exchangers 12 or 22 is defrosted, one system remains in the cooling cycle, the other system remains in the heating cycle, and the high pressure of the other system is Since defrosting can be performed using part of the heat of condensation of the gas, defrosting can be performed in a shorter time than when outdoor air is used as the defrosting heat source. Therefore, since the time to interrupt the heating cycle of one system is short, the room will not remain unheated for a long time, and moreover, the heat of condensation of the high-pressure gas in the other systems is not the entire amount, but only one amount. Because the system utilizes the internal heating system, heating in other systems can continue during defrosting.

In addition, since this defrost is performed using one system as a cooling cycle, it is possible to defrost economically without using a heater, etc.
The warm air in the room and the heat stored in the user-side heat exchanger 14 or 24 are not taken away, and the room is not cooled or a cold draft occurs.

Moreover, the liquid refrigerant condensed during defrosting of the heat source side heat exchanger 12 or 22 is transferred to the gas pipe 1 of one system.
6a or 26a in the defrosting heat exchanger 3 using the heat of condensation of the high-pressure refrigerant passing through the gas pipe 26a or 16a of another system as a heat source. Even if the refrigerants from each system are used, they do not mix. Therefore, even if defrosting is performed alternately, the amount of refrigerant in each system does not vary, and it is also possible to use different types of refrigerant in each system.

[Brief explanation of drawings]

FIG. 1 is a refrigerant piping system diagram showing one embodiment of the apparatus of the present invention, FIGS. 2a and 2b are schematic diagrams of a defrosting heat exchanger, and FIG. 3 is a refrigerant piping system diagram showing a conventional apparatus. 1, 2... Refrigerant circuit, 3... Defrost heat exchanger, 4, 5... Bypass pipe, 10, 20... Compressor, 11, 21... Four-way switching valve, 12, 22...
...heat source side heat exchanger, 14, 24...use side heat exchanger.

Claims (1)

[Claims] 1 Compressor 10, 20, four-way switching valve 11, 21,
It is equipped with two or more refrigerant circuits 1 and 2 in which air-type heat source side heat exchangers 12 and 22 and usage side heat exchangers 14 and 24 are systematically arranged, and the four-way switching valve 11,
In an air conditioner capable of heating and cooling by switching 21, the refrigerant circuit is connected between one switching port of the four-way switching valve 11, 12 in each refrigerant circuit 1, 2 and the user-side heat exchanger 14, 24, The gas pipes 16a and 26a, which serve as low-pressure gas pipes during cooling and high-pressure gas pipes during heating, are equipped with a defrosting heat exchanger 3 capable of mutually exchanging heat. Bypass pipes 4 and 5 are provided between the pipes 16b and 26b and the gas pipes 16a and 26a, bypassing the use-side heat exchangers 14 and 24 of each of these refrigerant circuits 1 and 2, so that the heat source-side heat exchange When defrosting the heat exchangers 12 and 22, the refrigerant circuit 1 or 2 of the heat source side heat exchanger 12 or 22 to be defrosted is set to the cooling cycle by switching the four-way switching valve 11 or 21, and the other is set to the heating cycle,
Opening the bypass 4 or 5 in the refrigerant circuit 1 or 2 of the cooling cycle, closing the bypass pipe 5 or 4 of the refrigerant circuit 2 or 1 of the heating cycle, and closing the gas pipe 26a or 16a of the refrigerant circuit 2 or 1 of the heating cycle. An air conditioner characterized in that the heat source side heat exchanger 12 or 22 in the refrigerant circuit 1 or 2 forming a cooling cycle is alternately defrosted using high-pressure gas flowing through the cooling cycle as a heat source.