JPS6255597B2 - - Google Patents

Description

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

Generally, when the heat source side heat exchanger is of the air type and is configured to exchange heat with outdoor air as described above, the heat source side heat exchanger will frost during heating operation.

Conventionally, when the heat exchanger is frosted, defrosting is performed by switching the four-way switching valve to create a cooling cycle, and using the heat stored in the user-side heat exchanger as a heat source to warm the room, or Also,
An electric heater is attached to the heat exchanger, and the heater is energized during frosting.

However, when defrosting is performed using the refrigerant circuit as a cooling cycle, as in the former case, the warm indoor air uses the heat stored in the heat exchanger on the user side as the heat source.
If the hot water in the heat exchanger on the user side cools down in a heated room, or if the heat exchanger on the user side installed indoors is an air type, there is a problem that a cold draft will occur. When defrosting is performed using a heater, an electric heater is additionally required as an accessory, and power is consumed during defrosting, resulting in an uneconomical problem.

Therefore, the present invention focuses on the fact that two or more independent refrigerant circuits each use a heat source side heat exchanger, and adds an auxiliary heat exchanger to the heat source side heat exchanger. Using an auxiliary heat exchanger attached to a heat source side heat exchanger of another system with a different system, a defrost heat source is taken in from outdoor air to defrost the heat source side heat exchanger. This enabled the heat exchanger to be used as a condenser during cooling operation, thereby improving the cooling capacity and coefficient of performance.

Therefore, the first object of the present invention is to perform economical defrosting by using the refrigerant circuit cycle as a cooling cycle when defrosting an air-type heat source side heat exchanger. This allows defrosting to be carried out without causing discomfort to the occupants by drawing in heat from the outdoor air without drawing heat from the heat stored in the heat exchanger or the user side heat exchanger.
The purpose of the present invention is to provide an air conditioner that can improve performance and coefficient of performance even during cooling, by attaching an auxiliary heat exchanger to the heat source side heat exchanger, and connecting high-pressure liquid pipes and low-pressure liquid pipes in the refrigerant circuit of each system. A bypass pipe having an on-off valve is provided between the gas pipe and the auxiliary heat exchanger attached to the heat source side heat exchanger of a different system is connected in the middle of each of these bypass pipes, and An expansion mechanism and a check valve that allows flow only to the high-pressure liquid pipe are interposed in parallel on the high-pressure liquid pipe connection side of the auxiliary heat exchanger in each bypass pipe, and on the low-pressure gas pipe connection side, Switchably connected to a gas pipe through which high-pressure gas flows at least during cooling through a three-way valve, and between the bypass pipe connection position of the high-pressure liquid pipe and the user-side heat exchanger,
It is characterized by being equipped with an on-off valve that closes during defrosting.

Embodiments of the device of the present invention will be described below based on the drawings.

In FIGS. 1 to 3, 1 and 2 are independent refrigerant circuits with different systems. Switching valves 11, 21, heat source side heat exchangers 12, 22, liquid receivers 13, 23, usage side heat exchangers 14, 24, and accumulator 15,
25, these devices are systematically piped by refrigerant pipes 16, 26, and the four-way switching valve 1
By the operations 1 and 21, the cooling cycle shown by the thick line in FIG. 1 and the heating cycle shown by the thick line in FIG. 2 are independently formed.

In addition, 17 and 27 are the liquid receivers 13 and 23,
A check valve 17 interposed in the refrigerant liquid pipes 16a, 26a connecting between the utilization side heat exchangers 14, 24.
A and 27a are cooling expansion valves connected in parallel, and 18 and 28 are refrigerant liquid pipes 16b and 26b connecting between the liquid receivers 13 and 23 and the heat source side heat exchangers 12 and 22, respectively. Check valve 18 installed in
This is a heating expansion valve in which a and 28a are connected in parallel.

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 drawings is an air conditioner configured as described above, in which the heat source side heat exchangers 12, 2
2, auxiliary heat exchangers 3 and 4 are respectively attached to the liquid receivers 13 and 23 in the refrigerant circuits 1 and 2 of the first and second systems, and a low pressure gas pipe 16c leading to the accumulators 15 and 25. , 26c, and in the middle of these bypass pipes 5, 6, the auxiliary heat exchanger 4, which is attached to the heat source side heat exchangers 22, 21 of different systems, respectively. In other words, the bypass pipe 5 provided in the refrigerant circuit 1 of the first system is connected to the auxiliary heat exchanger 4 attached to the heat source side heat exchanger 22 of the refrigerant circuit 2 of the second system. Further, the auxiliary heat exchanger 3 attached to the heat source side heat exchanger 12 of the first system is connected to the bypass pipe 6 provided in the refrigerant circuit 2 of the second system, and the Between the auxiliary heat exchangers 4, 3 and the liquid receivers 13, 23 of each bypass pipe 5, 6, only the flow to the electromagnetic on-off valves 51, 61 and the liquid receivers 13, 23 is provided. Allowing check valve 5
3 and 63 are connected in parallel, and a three-way valve 5 is installed on the connection side of each of the bypass pipes 5 and 6 to the low pressure gas pipes 16c and 26c.
4, 64, the first switching ports 54a, 64a of these three-way valves 54, 64 are connected to the low pressure gas pipes 16c, 26c, and the second switching port 54 is connected to the low pressure gas pipes 16c, 26c.
b, 64b is gas pipe 1 through which high pressure gas flows during cooling.
6d and 26d, respectively, while the refrigerant liquid pipes 16a and 26a in the refrigerant circuits 1 and 2 of each system, that is, the liquid receiver 13,
The refrigerant liquid pipes 16a, 26a connecting the cooling expansion valves 17, 27 with the cooling expansion valves 17, 27 are provided with electromagnetic on-off valves 7, 8 that are closed when the heat source side heat exchangers 12, 22 of each system are defrosted, respectively.

In the above configuration, the auxiliary heat exchangers 3, 4
may be formed separately from the heat source side heat exchangers 12, 22 and attached so that the fins are in close proximity or in contact with each other, but preferably, as shown in FIG.
00 is common, and the heat source side heat exchangers 12, 22
Between the rows of tubes a, the auxiliary heat exchangers 3, 4
The tubes a and b may be arranged alternately, or, although not shown, the tubes a and b may be arranged alternately.

Furthermore, although the bypass pipes 5 and 6 have their ends connected to the liquid receivers 13 and 23, they are connected directly to the high-pressure liquid pipes between the electromagnetic on-off valves 7 and 8 and the heating expansion valves 18 and 28. May be connected. Further, the other ends of the bypass pipes 5, 6, that is, the first switching ports 54a, 64a of the three-way valves 54, 64 are connected to the low pressure gas pipes 16c, 26c, but they may be connected to the accumulators 15, 25, Moreover, the three-way valves 54, 6
4, the second switching ports 54b and 64b are connected to the gas pipe 1 through which high-pressure gas flows during cooling and through which low-pressure gas flows during heating.
6d, 26d, high pressure gas pipes 16e, 26e through which high pressure gas flows during both cooling and heating.
may be connected to. Moreover, the three-way valves 54, 64
may each be two electromagnetic on-off valves.

In the above configuration, by locating the four-way switching valves 11 and 21 as shown in FIG. 1 and driving the compressors 10 and 20 of each system, the cooling cycle is started as shown by the arrow in FIG. The user-side heat exchangers 14 and 24 in the refrigerant circuits 1 and 2 of each system can perform cooling, respectively.

Moreover, during this cooling, the electromagnetic on-off valves 51 and 61 of the bypass pipes 5 and 6 are opened, and the three-way valves 54 and
By switching the second switching ports 54b, 64b of 64 so as to communicate with the gas pipes 16d, 26d, the high pressure gas refrigerant discharged from the compressors 10, 20 is transferred to the heat source side heat exchangers 12, 22.
and the auxiliary heat exchangers 4, 3, these auxiliary heat exchangers 3, 4 can be used as condensers.

Therefore, during cooling, by using the auxiliary heat exchangers 3 and 4 as condensers as described above, the high pressure can be operated at a low level, the cooling capacity can be increased, and the coefficient of performance can be improved. This enables highly efficient cooling operation.

Further, the four-way switching valves 11 and 21 are positioned as shown in FIG. 2, and the compressors 10 and 21 of each system are
A heating cycle is formed as shown by the solid line arrow in FIG. 2, and heating can be performed by each of the user-side heat exchangers 14 and 24.

Moreover, even during heating, the electromagnetic on-off valves 51, 61 of the bypass pipes 5, 6 are opened, and the first switching ports 54a, 64a of the three-way valves 54, 64 are opened.
The user side heat exchanger 1 is switched so that it communicates with the low pressure gas pipes 16c and 26c.
The liquid refrigerant condensed in 4 and 24 is evaporated from the bypass pipes 5 and 6 in the auxiliary heat exchangers 4 and 3, respectively, and the effective area of the heat source side heat exchangers 12 and 22 during heating is can be increased,
This makes it possible to increase heating capacity and improve the coefficient of performance. In addition, when heating, three-way valve 5
4 and 64 may be switched as shown in FIG. 2 or as shown in FIG. 1, but by switching as shown in FIG. 2, the flow resistance of the four-way switching valves 11 and 21 can be reduced.

Furthermore, when performing heating as described above, the heat source side heat exchangers 12, 22 and the auxiliary heat exchangers 3, 4
However, each will be frosted. Defrosting at the time of frosting is carried out for each system. For example, when defrosting the heat exchanger 12 provided in the refrigerant circuit 1 of the first system and the heat exchanger 3 attached thereto, defrosting is performed for each system. As shown in the diagram,
The four-way switching valve 11 of the first system is located on the cooling side as in FIG. 1, and the four-way switching valve 21 of the second system is located on the heating side as in FIG. This is done by closing the electromagnetic on-off valve 7 of one system and the electromagnetic on-off valve 61 in the bypass pipe 6 of the second system, and stopping the fans F ₁ and F ₃ .

Note that the electromagnetic on-off valve 51 in the bypass pipe 5 of the first system and the electromagnetic on-off valve 8 of the second system remain open, and the three-way valves 54 and 64 are closed during heating as shown in FIG. Similarly, the first switching port 54
a, 64a are communicated with the low pressure gas pipes 16c, 26c.

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. .
At this time, the auxiliary heat exchanger 3 attached to the heat source side heat exchanger 12 has no refrigerant flow, and can be defrosted by heat conduction from the heat source side heat exchanger 12, which serves as a condenser.

Then, the liquid refrigerant condensed in the heat source side heat exchanger 12 is transferred to the first
Without flowing to the utilization side heat exchanger 14 of the system, the entire length passes through the bypass pipe 5, flows to the auxiliary heat exchanger 4 attached to the heat source side heat exchanger 22 of the second system, and is evaporated. It returns to the compressor 10.

As described above, during defrosting, the user-side heat exchanger 14 of the first system uses the auxiliary heat attached to the heat source-side heat exchanger 22 of the second system, which exchanges heat with outdoor air instead of using indoor warm air as a heat source. Since the defrost heat source is taken in from the outdoor air using the exchanger 4, the interior of the room is not cooled and cold drafts do not occur. Moreover, since the air conditioning cycle is switched to and outdoor air is used as the heat source, there is no need to use an electric heater, and defrosting can be performed economically.

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 and the auxiliary heat exchanger 4 of the system can be defrosted.

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, and if they are separated, the indoor unit may be Not only one unit but also multiple units may be connected in each system.

As described above, the present invention provides an air-to-air heat source side heat exchanger provided in two or more independent refrigerant circuits, each with an auxiliary heat exchanger, and a bypass pipe provided for each system. When connected to the auxiliary heat exchanger attached to the heat source side heat exchanger of the system, and when the heat source side heat exchanger frosts and defrosts, the auxiliary heat exchanger attached to the heat source side heat exchanger of another system is used. However, since the defrost heat source is taken from the outdoor air, defrosting can be performed economically by using the refrigerant circuit as a cooling cycle, but during defrosting, the warm air inside the room and the heat stored in the heat exchanger on the user side are taken away. Therefore, the room will not be cooled and cold drafts will not occur.

Moreover, in each of the bypass pipes, an expansion mechanism and a check valve that only allows flow to the high-pressure liquid pipe are interposed in parallel on the high-pressure liquid pipe connection side of the auxiliary heat exchanger, and a low-pressure gas pipe Since a three-way valve is interposed on the connection side and the bypass pipe is switchably connected to the gas pipe through which high-pressure gas flows during cooling, the three-way valve connects the bypass pipe to the gas pipe through which high-pressure gas flows during cooling. , each of the auxiliary heat exchangers that take in a defroft heat source from outdoor air as the defrost evaporator can be used as a condenser without being idle, thus improving the capacity and improving the coefficient of performance. Highly energy-efficient cooling operation is possible, and when the bypass pipe is connected to the low-pressure gas pipe by the three-way valve during heating, the auxiliary heat exchanger can also be used as an evaporator. It is also possible to improve heating capacity and coefficient of performance.

[Brief explanation of the drawing]

Figures 1 to 3 show an embodiment of the device of the present invention. Figure 1 shows a cooling cycle, Figure 2 shows a heating cycle, and Figure 3 shows a heating cycle using the second refrigerant circuit. 4 is a refrigerant piping system diagram in which the cycles for defrosting in the first refrigerant circuit are shown in bold lines, and FIG. 4 is a sectional view showing the relationship between the heat source side heat exchanger and the auxiliary heat exchanger. . 1, 2... Refrigerant circuit, 3, 4... Auxiliary heat exchanger, 5, 6... Bypass pipe, 7, 8... Open/close valve,
10,20...Compressor, 11,21...Four-way switching valve, 12,22...Heat source side heat exchanger, 14,24
... User side heat exchanger, 51, 61 ... Opening/closing valve, 5
2,62...Expansion valve.

Claims (1)

[Claims] 1 Equipped with a compressor, a four-way switching valve, a heat source side heat exchanger, and a user side heat exchanger, and has two or more independent first and second refrigerant circuits in which these devices are systematically piped, and the heat source The side heat exchanger is an air type,
The air conditioner is capable of heating and cooling using the four-way switching valve, and an auxiliary heat exchanger is attached to the heat exchanger on the heat source side, and an auxiliary heat exchanger is attached between the high-pressure liquid pipe and the low-pressure gas pipe in the refrigerant circuit of each system. , a bypass pipe having an on-off valve is provided, and the auxiliary heat exchanger attached to the heat source side heat exchanger of another system is connected to the middle of each of these bypass pipes, and the An expansion mechanism and a check valve that only allows flow to the high-pressure liquid pipe are installed in parallel on the high-pressure liquid pipe connection side of the auxiliary heat exchanger, and a three-way valve is installed on the low-pressure gas pipe connection side. while being switchably connected to a gas pipe through which high-pressure gas flows at least during cooling;
An air conditioner characterized in that an on-off valve that closes during defrosting is interposed between the bypass pipe connection position of the high-pressure liquid pipe and the user-side heat exchanger.