ES2425597T3 - Refrigeration cycle apparatus - Google Patents

Abstract

A refrigeration cycle apparatus comprising: first and second outdoor units (20 a; 20b), each of which includes a compressor (1), an outdoor heat exchanger (2), a port (5) of gas connection, channel switching valves (3) through which channels can be arbitrarily switched in order to communicate one of an intake port and a compressor discharge port with the gas connection port (5) and communicate the other with one end of the external heat exchanger (2), and a liquid connection port (6) connected to the other end of the external heat exchanger (2); a plurality of indoor units (21 a; 21b; 21c) in which the indoor liquid pipes, indoor heat exchangers (30), and indoor gas pipes (32) are connected in order; and a common liquid pipe (10) through which the liquid connection port of each outdoor unit (20 a; 20b) communicates with the indoor liquid pipes of the plurality of indoor units (21 a ; 21b; 21c), where each of the indoor gas pipes (32) 32 in the respective indoor units (21 a; 21b; 21c) is branched into a first gas pipe (11) and a second pipe (12) of gas, whose first gas pipe (11) is connected to the gas connection port of one of the outdoor units (20 a), whose second pipe (12) is connected to the gas connection port of the other of the outdoor units (20 b), pipe switching units (22), each of which switches the respective channels of the first gas pipe (11) and the second gas pipe (12) in each of the indoor units (21 a; 21b; 21c) characterized in that each of the heat exchangers (30) indoor is connected to only one of the outdoor units (20 a; 20b) by switching the pipe switching units (22).

Description

Refrigeration cycle apparatus.

(1) Field of the invention.

The present invention relates to a refrigeration cycle apparatus formed by connecting a plurality of outdoor units to a plurality of indoor units.

(2). Description of the technique related to the invention.

A system of the variable refrigerant flow type (hereinafter VRF) is known for simultaneous heating and cooling as described, for example, in Japanese patent number 3289366, in which a plurality of outdoor units and a plurality of indoor units are connected in parallel using a high pressure gas pipe, a low pressure gas pipe, and a liquid pipe to form a refrigeration cycle, and an operation of simultaneous operation can be carried out. cooling and a heating operation in the plurality of indoor units.

The refrigeration apparatus includes a plurality of heat source units (outdoor units), a plurality of user units (indoor units), a main liquid pipe, a high pressure gas main pipe, a main water pipe low pressure, and a pipe unit.

Each of the heat source units includes a compressor, a heat exchanger on the side of the heat source, one end of which is connected to the discharge side and the intake side of the compressor in a switchable manner and the other end is connected to a liquid pipe, and a decompression device on the side of the heat source provided in the liquid pipe. Additionally, the proximal end of a branched gas pipe in a high pressure passageway that allows a refrigerant flow to flow from the compressor in the discharge direction and a low pressure passageway that allows the refrigerant to circulate in the direction of admission of the compressor is connected to the discharge side and the intake side of the compressor in a switchable manner.

The respective liquid pipes, high pressure passage lines, and low pressure passage lines are connected to the main liquid pipe, the main high pressure gas pipe, and the main low pressure pipe in order to connect in parallel to the respective heat source units. Each of the user units includes a heat exchanger on the user side one of whose ends is connected to the main liquid pipe, and a decompression device on the user side provided between the heat exchanger d the side d user and the main liquid pipe. In addition, the other end of the heat exchanger on the user side is connected to the main high pressure gas pipe and to the main low pressure gas pipe in a switchable manner.

The pipe unit includes a check valve that allows the refrigerant to circulate from the heat source units to the main high-pressure gas pipe, and another check valve that allows the refrigerant to circulate from the main gas pipe. Low pressure to heat source units.

In addition, an auxiliary gas pipe is provided one of whose ends is connected to a refrigerant pipe on the gas side of the heat exchanger on the heat source side of a heat source unit, the other end of which is connected to the main line of high pressure gas and the main line of low pressure gas, and which includes a high pressure auxiliary passageway that allows the refrigerant to circulate from the heat source units to the main high gas pipe pressure, and a low pressure auxiliary passageway that allows the refrigerant to circulate from the main low pressure gas pipeline to the heat source units.

In the refrigeration apparatus described above, a cooling operation and a heating operation can be carried out simultaneously by connecting the heat source units, in parallel, in which the cooling operation and the heating operation are they can be performed in a switchable manner, and thus there is advantageously no need for exclusive outdoor heat source units in which the cooling and heating operations can be performed simultaneously. However, it is necessary to provide a pipe unit having a complex structure due to the connection of the refrigerant pipe of each of the heat source units to the main high-pressure gas pipe and the main gas pipe Low pressure in a switchable way. Additionally, when the refrigeration apparatus is assembled, it is necessary to secure a space to install the pipeline unit, resulting in a problem of an increase in the installation area. For comparison, when exclusive heat source units are used for a cooling operation and a heating operation, the pipeline unit is not required.

WO 2008/069066 describes an apparatus according to the preamble of claim 1.

In view of the problem set forth above, an object of the present invention is to provide a refrigeration cycle apparatus of the simultaneous cooling and heating type without installing a pipeline unit outside and

with a simple configuration that can be used for a cooling operation and a heating operation in a switchable manner.

Compendium of the invention.

The present invention provides a refrigeration cycle apparatus that includes: first and second outdoor units, each including a compressor, an outdoor heat exchanger, a gas connection port, valves with channel mutation It gave me one of the channels that can be arbitrarily switched in order to one of an intake port and a discharge port of the compressor with the degas connection port and to communicate the other with one end of the heat exchanger. outdoor heat, and a liquid connection ports connected to the other end of the outdoor heat exchanger; a plurality of indoor units in which indoor liquid pipes, indoor heat exchangers, and indoor gas pipes are connected in order; and a common liquid pipeline through which the liquid connection port of each outdoor unit communicates with the indoor liquid pipes in the plurality of indoor units, where each of the indoor gas pipes in the respective indoor units it is branched into a first gas pipe and a second gas pipe, whose first gas pipe is connected to the gas connection port of one of the outdoor units, whose second gas pipe connected to the connection port of the other of the outdoor units, a pipeline switching units, each one that switches the respective channels of the first gas pipe and the second gas pipe in each of the units indoor, and each of the indoor heat exchangers is communicated with only one of the outdoor units by switching the pipeline switching units.

In addition, in the refrigeration cycle apparatus described above, when a cooling operation and a heating operation are simultaneously performed, one of the first and second outdoor units forms a heat absorption cycle by switching the units of pipeline switching in order to communicate the discharge port of the compressor with the gas connection port, and the other of the outdoor units forms a heat discharge cycle by switching the pipeline switching unit with the in order to communicate with the outdoor unit of the heat absorption cycle, and the indoor unit that performs the heating operation is switched by the pipeline switching unit in order to communicate with the outdoor unit of the absorption cycle of heat, and the indoor unit that performs the cooling operation is switched by the pipeline switching unit in order of communicating with the outdoor unit of the heat discharge cycle.

In addition, in the refrigeration cycle apparatus described above, between the first outdoor unit and the second outdoor unit that form the heat absorption cycle or the heat discharge cycle, the cycles can be switched alternately, and The pipeline switching units are switched according to the cycle switching.

Additionally, in the refrigeration cycle apparatus described above, by alternately switching the cycles between the first outdoor unit and the second outdoor unit, a defrosting operation is performed for the outdoor heat exchanger of the outdoor unit that forms the heat absorption cycle.

In addition, in the refrigeration cycle apparatus described above, while the compressor capacity of the outdoor unit that forms the heat discharge cycle is controlled based on a required cooling load of the indoor unit that performs the operation of cooling, the compressor capacity of the outdoor unit that forms the heat absorption cycle is controlled based on a heating load of the indoor unit that performs the heating operation.

In addition, in the refrigeration cycle apparatus described above, the first control valves and the second control valves are electrically operated expansion valves.

In addition, in the refrigeration cycle aspect described below, when the cooling operation or the heating operation is carried out, the outdoor units that are communicated with the respective indoor units can be switched by the pipeline switching units.

Additionally, in the refrigeration cycle apparatus described above, a switching function of the indoor units that communicate with the respective outdoor units based on the capacity information of each indoor unit and the temperature of the indoor unit has been provided. intake air

According to the present invention, it is possible to provide a simultaneous cooling and heating type refrigeration cycle apparatus with a simple configuration using outdoor units in which a cooling operation and a heating operation can be performed in a manner switchable

Brief description of the drawings.

Fig. 1 is a diagram of the cycling system or which shows a flow of a refrigerant where a cooling operation and a heating operation are performed simultaneously according to a first embodiment of the present invention;

Figure 2 is a cycle system diagram showing a flow of the refrigerant when the operations of the indoor units are switched according to the first embodiment of the present invention;

Fig. 3 is a cycle system diagram showing a flow of the refrigerant when the operations of the outdoor units are switched according to the first embodiment of the present invention;

Figure 4 is a cycle system diagram showing a refrigerant flow when the cooling operation is performed in accordance with the first embodiment of the present invention;

Figure 5 is a cycle system diagram showing a refrigerant flow when the cooling operation is carried out at different temperatures according to the first embodiment of the present invention;

Figure 6 is a cycle system diagram showing a refrigerant flow when the heating operation is performed according to the first embodiment of the present invention;

Figure 7 is a cycle system diagram showing a flow of the refrigerant when the heating operation is performed at different condensation temperatures according to the first embodiment of the present invention;

Figure 8 is a configuration diagram of a pipe switching unit according to the first embodiment of the present invention; Y

Figure 9 is a cycle system diagram showing a configuration in which 3 outdoor units are provided in accordance with a second embodiment of the present invention.

Detailed description of the realization.

Next, a simultaneous cooling and heating refrigeration cycle apparatus according to embodiments of the present invention is described in detail with reference to Figures 1 to 9.

First realization

Next, a first embodiment of the invention is described with reference to Figures 1 to 3. Figure 1 is a cycle system diagram showing a configuration of a refrigeration cycle apparatus of the embodiment. In the embodiment, a refrigeration cycle has been configured such that two outdoor units 20 a and 20b and three indoor units 21 a, 21b and 21c are connected to each other by means of three pipes of a common liquid pipe 10, a first gas pipe 11, and a second gas pipe 12. In each of the indoor units 21, an indoor heat exchanger 30 is connected to the common liquid pipe 10 through an internal liquid pipe (10 a, 10b, or 10c) and a decompression unit 31, and an inner pipe 32 is connected to the other end of each indoor heat exchanger 30. Each of the interior gas pipes 32 is connected to the first gas pipe 11 and the second gas pipe 12 through a pipe switching unit 22.

In each of the pipe switching units 22 (22 a, 22b, and 22c), a pipe connected to the inner gas pipe 32 branches into gas pipes (a first gas pipe and a second gas pipe ) of two systems. A pipe system of each unit is connected to the first gas pipe 11 through a first control valve and the other pipe system of each unit is connected to the second gas pipe 12 through a second control valve 42. The pipe channels are opened and closed using the first control valves 43 and the second control valves 42, such that the communication states between the interior gas pipes 32 and the first gas pipe 11 or the second Gas pipe 12 can be switched arbitrarily.

The first gas pipe 11 and the second gas pipe 12 are connected to a gas connection port 5 a of the first gas indoor unit 20 a and a connection port 5b of the second outdoor unit 20b, respectively. In addition, both liquid connection ports 6 a and 6b of the respective outdoor units 20 a and 20b are connected to the common liquid pipe 10.

Each of the outdoor units 20 is provided with a compressor 1 and an outdoor heat exchanger 2, one end of the outdoor heat exchanger 2 is connected to the liquid connection port 6, and a decompression device has been provided in the laying of pipes. The other end of each external heat exchanger 2 d is connected to a 4-way valve 3 that serves as a channel switching valve, and the four-way valve 3 allows the other end of the heat exchanger 2 of

outside selectively communicate with one of an intake port and a compressor discharge port. In addition, the other one between the inlet and discharge ports of each compressor 1 can communicate with the gas connection port 5 through the four-way valve 3. The four-way valve 3 a of the first outdoor unit 20 a and the four-way valve 3b of the second outdoor unit 20b are configured to arbitrarily switch the channels.

The operation will then be shown when simultaneous cooling and heating operations (a cooler and two heaters) are performed in the realization. In Fig. 1, the arrows show an example of flow directions of a refrigerant (not shown) in the case where a cooling operation is performed on the indoor unit 21c and a heating operation on the indoor units 21 a and 21b The four-way valve 3 a is in a connection state shown by the solid lines. In the outdoor unit 20 a, the discharge port of the compressor 1 a is allowed to communicate with the outdoor heat exchanger 2 to form a heat discharge cycle in which a condensed liquid refrigerant through the use of an external heat exchanger 2 a as a condenser is fed to the common liquid pipe 10 through the lamp 6 with a liquid discharge. On the other hand, at the outer unit 20b, the channels have been configured as shown by the solid lines on the four-way valve 3b, such that the discharge port of the compressor 1b communicates with gas connection ports 5b. The liquid refrigerant flowing to the outdoor unit 20b is decompressed by means of an expansion valve 4b to lower its temperature and pressure, and then flows to the compressor 1b after evaporating through the outdoor heat exchanger 2b. As described above, the outdoor unit 20b forms a heat absorption cycle in which heat is taken from the outside air.

The liquid refrigerant is supplied from the common liquid pipe 10 to the indoor unit 21c which performs the cooling operation. The liquid refrigerant is decompressed by an indoor expansion valve 31c to lower its low temperature and pressure, and then evaporated after taking heat from the indoor air in the indoor exchanger 30c. The indoor air temperature is lowered by the necessary action to perform the cooling operation. The refrigerant evaporated by the indoor heat exchanger 30c passes through the indoor gas pipe 32c, and flows into the pipe switching unit 22c. In the embodiment, by opening the first control valve 43c and closing the second control valve 42c, the refrigerant is allowed to flow from the first gas pipe 11 to the first at unit 20 a day and outside. Next, the refrigerant is compressed by the first outdoor unit 20 to which the heat discharge cycle forms, and the heat is released to the outside air by the outdoor heat exchanger 2 to for its devolatilization. Then, the devolatilized refrigerant returns to the common liquid pipe 10.

On the other hand, a high temperature and high pressure refrigerant is supplied from the second gas pipe 12 to the indoor units 21 a and 21b which perform the heating operation. The refrigerant compressed by the compressor 1b of the second outdoor unit 20b is supplied to the second gas pipe 12. By closing the first control valve 43 a and opening the second control valve 42 a in the pipeline switching unit 22 a, the high temperature and high pressure gaseous refrigerant is introduced into the indoor heat exchanger 30 from the second gas pipe 12 to perform the heating operation. At this time, the expansion valve 31 is fully open, and the refrigerant condensed and devolatilized by the heat exchanger 3 0 of internal flow and forced the pipeline with liquid 1 0 0. In addition, the same operation is also performed in the indoor unit 21b and in the pipeline switching unit 22b, and the heating operation is performed.

As described above, the liquid refrigerant flows to the common liquid pipe 10 from the indoor units 21 a and 21b which perform the heating operation and from the first outdoor unit 20 to which the heat discharge cycle forms, and separately it flows out to the indoor unit 21c that performs the cooling operation and to the second outdoor unit 20b that forms the heat absorption cycle. Accordingly, the direction of the flow of the refrigerant within the common liquid pipe 10 is changed in sequence by the cooling load and the heating load in each of the indoor units.

The operations in the case where only the indoor unit 21 b carrying out the heating operation of Figure 1 is switched to the cooling operation (two coolers and a heater) using Figure 2 are described below. The operations of the outdoor units 20 a and 20 b and of the indoor units 21 a and 21c are the same as those of the embodiment shown in Figure 1, and the operations of the indoor unit 21 a and the pipe switching unit 22 they are changed to the same as the indoor unit 21 ce and the pipe switching unit 22c.

Specifically, the refrigerant supplied from the common liquid pipe 10 is decompressed using an expansion valve 31 b, and evaporated by the indoor heat exchanger 30b. Next, the resulting refrigerant is allowed to flow out to the first gas pipe 11 through the first control valve 4 3b that is open. In this moment, the second control valve 4b is closed. Lugo, the operating capacities (operating frequencies) of the respective compressors 1 a and 1b are changed according to the changes in the heating load capacity and the cooling load capacity. As described above, the handling of the respective valves 31 b, 42 b and 43b of the unit of

indoor 21b is changed, so that the heating operation and the cooling operation can be arbitrarily switched for each indoor unit.

In the above-described embodiment, two outdoor units are used in which the cooling operation and the heating operation can be performed in a switchable manner, such that it is possible to configure the cooling cycle apparatus of the cooling type and Simultaneous heating in which the cooling operation and the heating operation can be performed for each indoor unit in an arbitrarily switchable manner. In addition, in the embodiment, the respective indoor heat exchangers are connected to (communicated with) one of the first outdoor unit 20 a and the second outdoor unit 20b through the switching of the switching units 22 of your berias . In addition, even though the liquid connection ports 6 a and 6b of the respective outdoor units 20 a and 20b are coupled to each other through the common liquid pipe 10, it is not necessary to connect the first gas pipe 11 to each other. and the second gas pipe 12. Accordingly, there is no need for the exclusive and complicated pipeline unit described in the technique related to the invention for connecting pipes, thereby preventing not only an increase in an installation zone, but also in perfection. Installation capacity work. Especially, the first gas pipe 11 and the second gas pipe 12 have a deficient activity due to their large diameters compared to the liquid pipe 10. Accordingly, the elimination of the connection of these pipes leads to an improvement in the capacity of installation work.

In the embodiment shown in Figure 1, the indoor unit 21c that performs the cooling operation communicates with the outdoor unit 20 a that performs the heat discharge operation through the first gas pipe 11. In this mode, the cooling capacity is controlled by the capacity of the compressor 1 provided in the first outdoor unit 20. On the other hand, the indoor units 21 a and 21b that carry out the heating operation communicate with the outdoor unit 20b that performs the heat absorption operation through the second gas pipe 12. In this way, the heating capacity is controlled by the operating capacity of the compressor 1b provided in the second outdoor unit 20b. Furthermore, in the embodiment shown in Figure 2, as the indoor unit 21b is switched from the heating operation to the cooling operation, the operating capacity of the compressor 1 could thus be controlled by the operating frequency according to the operating loads. cooling of the indoor units 21b and 21c performing the cooling operation, and the operating capacity of the compressor 1b could be controlled by the operating frequency according to the heating load of the indoor unit 21 to which the heating operation performs.

In the case where the heating and cooling operations are carried out simultaneously using an outdoor unit, heat is released or absorbed from the outdoor heat exchanger of a conventional technique, resulting in complicated control. Additionally, even in the case where the outdoor unit is a heat radiator, it is necessary to control the balance between the heat discharge and the outside air and the heat discharge to the indoor heating unit. However, the cooling capacity and the heating capacity can be easily controlled because they can be controlled separately by means of the operating capacities of the compressors 1 a and 1b of the embodiment.

It should be noted that the cooling and heating capacities of the indoor units are obtained based on the information of the capabilities of the units of interest and the temperature of the intake air, and they work to switch the units indoor that communicate with the respective outdoor units. As described above, the operating capacities of the compressor 1 a and the compressor 1b are determined according to the cooling load and the heating load, and the respective compressors are accordingly operated at different operating frequencies.

Incidentally, each compressor maintains an oil inside it, a part of the maintained oil flows out during the cycle together with the heat discharged refrigerant, and then returns to the compressor along with the intake coolant. However, when a plurality of outdoor units are used as in the case of the embodiment, there is a possibility that the oil is retained disproportionately by the respective compressors 1 a and 1b. Therefore, if the amount of oil is insufficient, there is a risk that the problem of the compressors will be damaged, and it is important to avoid insufficient oil.

In addition, a ratio between the amount of oil flowing out of the compressors during the cycle and the amount of refrigerant flowing tends to increase as the capacity of the operation increases. Accordingly, in the case where compressors 1 to y1b are operated at different frequencies, as in the case of the realization of the present memory, the amount of the refrigerant retained by the compressor 1b is likely to decrease disadvantageously of operation (large capacity). In order to solve the problem, the operations can be properly switched between outdoor units 20 a and 20b as shown in Figure 3 in the embodiment.

Specifically, while the 3-way valve 3 a of the first outdoor unit 20 to which the discharge cycle in Figure 1 forms is switched to a connection state shown by the solid line, such that the cycle of Heat discharge is switched to the heat absorption cycle, the valve 3b four ways of the

The second outdoor unit 20b that forms the heat absorption cycle is switched to a connection state shown by the solid lines, such that the heat absorption cycle is switched to the heat discharge cycle.

Furthermore, while the first control valve 43 c of the pipe switching unit 22 c connected to the indoor unit 21c performing the cooling operation is closed, the second control valve 42c is open. Accordingly, the indoor heat exchanger 30c is allowed to communicate with the second outdoor unit that forms the heat discharge cycle. In the switching units 22 a and 22b of pipes connected to the indoor units 21 a and 21b, respectively, which perform the heating operation, the first control valves 43 a and 43b are open, and the second control valves 42 a and 42b are closed. Accordingly, the indoor heat exchangers 30 a and 30b can communicate with the first outdoor unit 20 to which the heat absorption cycle forms.

In the realization of the present specification, the opening and / or closing states of the first control valves 43 and the second control valves 42 of the pipe switching units can be switched according to the operations of the respective units. outdoor 20 to y20 b, so that the indoor unit that performs the cooling operation communicates with the outdoor unit that forms the cycle or heat discharge and the indoor unit that performs the heating operation communicates with the outdoor unit that forms the heat absorption cycle. In this way, the operations of the outdoor units can be properly switched easily.

Therefore, in the case where it is determined that there is a possibility of a disproportionate balance in the amount of oil as described above, said problem can be avoided by appropriately commuting the operations of the outdoor units. When a state in which a difference between the operating capacity of both compressors is greater than a predetermined continuous value over a long time, the switching operations of the outdoor units could be performed, or the units of the units could be periodically switched. outside depending on a time of operation.

It should be noted that the object for the commutation of the operations of the outdoor units is not limited to avoiding the disproportionate balance in the amount of the oil, but it could be to establish a rotation in which, for example, the cumulative operating times of the respective compressors.

In addition, as one of the conditions under which the switching operation is performed, said switching operation could be initiated at the same times when a defrosting operation has started to melt the frost developed on a surface of the heat exchanger of exterior of the outdoor units that forms the heat absorption cycle. If the switching operation does not start at the same times, the problem arises that the high temperature refrigerant cannot be supplied to the indoor unit that performs the heating operation during the defrosting operation. Therefore, the switching operation starts at the same times as the defrosting operation, such that the outdoor unit that forms the heat discharge cycle, namely the outdoor unit to which it has not been fixed Frost, can be used while the heat absorption cycle is formed. In this way, it is not necessary to stop the heating operation in the indoor unit by means of the defrosting operation and comfort can be improved.

It should be noted that the outdoor unit that performs the defrosting operation still forms the heat discharge cycle functioning as a condenser, even after the frost has melted and the defrosting operation has been completed. The heat released in such a way can be used as a heat to melt the frost, and therefore the energy saving can be improved compared to a case in which the defrosting operation is performed without switching the operations between the outdoor units.

The operations are described below when the cooling operation is performed using Figure 4. In the realization of the present specification, the arrows show the flow of the refrigerant in the case where the cooling operation is performed in the three indoor units 21. Both outdoor units 20 a and 20b form the heat discharge cycle, and allow the compressors 1 to aspirate and compress the refrigerant gas in the first gas lines 11 and in the second gas pipe 12. After the heat of the compressed refrigerant has been released for devolatilization by means of heat exchangers 2, the liquid refrigerant is supplied to the common liquid pipe 10. In the respective indoor units 21, after the refrigerant has been decompressed by means of the respective expansion valves 31, the resulting refrigerant is evaporated and gasified by the respective indoor heat exchangers 30. Next, by opening both first control valves 43 that communicate with the first gas pipe 11 and the second control valves 42 that communicate with the second gas pipe 12, the refrigerant is returned to the respective outdoor units 20 using the first gas pipe 11 and the second gas pipe 12. Since two gas pipes have been used, a pressure drop can be reduced and energy saving can be advantageously improved compared to a case in which only one gas pipe is used.

In addition, it is not necessary to always operate the two outdoor units 20 a and 20 b. If the cooling load is small, only one outdoor unit could work. For example, in the case that only the first outdoor unit 20 a is operated, the compressor 1b stops and the shut-off valve closes.

expansion 20 a. Additionally, the second control valves 42 that serve to connect the second gas pipe 12, which communicate with the second outdoor unit 20 b to the respective indoor units 21, are closed. Said operation enables the cooling operation using only an outdoor unit 20 a.

It should be noted that, while the first outdoor unit 20 a could be stopped, the second outdoor unit 20b could be operated. In this case, the operations of the respective outdoor units are changed, the first control valves 43 connected to the first gas pipeline are closed, and the second control valves 4 2 connected to the second pipeline are closed. of gas be bren. As stated above, the closing and / or opening states of the first control valves and the second control valves are switched according to the operations of the outdoor units 20 a and 20b, so that If the cooling or heating operation is stopped, the operating states of the outdoor units 20 a and 20b can be switched. By switching operations, the cumulative operating times of compressors 1 a and 1b can be equalized, and reliability can be increased.

Incidentally, the respective indoor units are under different ambient temperature environments in some cases. In general, an evaporation temperature can be elevated under a high ambient temperature environment, while an evaporation temperature needs to be lowered under a low ambient temperature environment. If the operating temperature is high, the energy saving is improved. However, the refrigerant pressures in the respective indoor units become substantially the same, namely, the same operating temperature occurs because the indoor units communicate with each other through the first gas pipe 11 and the second gas pipe 12. Therefore, in the case where the indoor units are installed under different ambient temperature environments, the evaporation temperature is varied according to the low ambient temperature environment, thereby reducing the energy saving in the whole apparatus of refrigeration cycle.

In order to solve the problem, the outdoor units that communicate with the indoor units can be arbitrarily switched according to the loads of the respective environments as shown in Figure 5 in the realization of the present specification. It is assumed that, based on the information of the intake air temperatures in the environments, only the indoor unit 21c is low in the ambient temperature and it is determined that the evaporation temperature of the indoor unit 21c needs to be kept low compared to the indoor units 21 a and 21b. In such a case, both of the first control valves 43 and the second control valves 42 are open in Figure 4. However, only one valve in each indoor unit is open in Figure 5, such that the Outdoor units that communicate with the respective indoor units can be arbitrarily switched.

Specifically, in indoor units 21 a and 21b where the operating temperature could be high, the first control valves 43 are closed and the second control valves 42 are open. Accordingly, the evaporated gas is introduced into the second unit 20b through the second gas pipe 12. On the other hand, in the indoor unit 21c where the evaporation temperature is low, the first control valve 43 is open and the second control valve 42 is closed. Accordingly, the refrigerant is returned to the first outdoor unit 20 through the first gas pipe 11.

Since the common liquid pipe 10 is shared by the first outdoor unit 20 a and the second outdoor unit 20b, the respective compressors 1 a and 1b have the same discharge pressure. However, the intake pressure of the compressor 1 a is determined based on the evaporation temperature of the indoor unit 20 c, and the intake pressure of the compressor 1b is determined based on the evaporation temperatures of the indoor units 20 a 20b Accordingly, compressors 1 a and 1b could be different in the intake pressure. Thus, while the inlet pressure of the compressor 1b can be increased, the compressive power of the compressor 1b can be increased, compared to a case in which both compressors 1a and 1b are operated with a low inlet pressure of according to the evaporation temperature of the indoor unit 20c, thereby improving energy saving.

The operations are described below when the heating operation is performed using Figure 6. The outdoor units 20 a and 20 b form the heat absorption cycle at the time of the heating operation. Once the refrigerant supplied from the common liquid pipe 10 has evaporated by means of the outdoor heat exchangers 2 and that the resulting refrigerant has been compressed by the compressors 1, the high temperature and high pressure refrigerant is supplied to the respective indoor units 20 using the first gas pipe 11 and the second gas pipe 12. Only one of the outdoor units could be operated according to the heating load, or two units could be operated at the same time. At this time, between the first control valves 43 and the second control valves 42 of the indoor units, the valves that communicate with the outdoor unit 20 being operated open and close properly according to the operation of the outdoor unit 20.

Additionally, as shown in Figure 7, one of the first was control valve 43 and of the second control valve 42 is open and the other is closed in each indoor unit. Accordingly, the outdoor units 20 communicating with the respective indoor units 21 could be arbitrarily switched from a similar method to the cooling function. In the cycle of carrying out this report, the

compressors 1 to y1b can be operated at different condensation temperatures, that is, at different discharge pressures under the condition that ambient temperatures vary widely. Thus, compressors 1 a and 1b are effective in improving energy savings.

It should be noted that, in the event that the cooling or heating operation is switched to only one of the outdoor units that are communicating, if the total capacity of the indoor units that are communicating with the unit of Outside exceeds the nominal capacity of the outdoor unit, there is a possibility that a problem arises in the sense that the cooling capacity or the heating capacity becomes insufficient. In addition, since the compressors 1 of the respective outdoor units 2 0 operate at different operating capacities, there is a possibility of a disproportionate balance in the amount of oil between the compressors 1 as indicated above. . Therefore, it is convenient that the operations between the outdoor units 20, and the outdoor units 20 connected to the respective indoor units 21 be appropriately switched.

Only when the greater total capacity of the indoor units between the total capacity of the indoor units connected to the first outdoor unit 20 a and the total capacity of the indoor units connected to the second outdoor unit 20b is less than the capacity smaller than the outdoor unit, you can switch the indoor units that communicate with the outdoor unit. Therefore, even when the operations are switched between the outdoor units and even when the outdoor units 20 a and 20b are different from each other in nominal capacity, it is possible to avoid the problem of insufficient cooling capacity or capacity of heat and prevent a decrease in the reliability of the disproportionate balance in the amount of oil.

Incidentally, if the first control valves 43 are open in the realization of the present specification, the refrigerant flows from the first gas pipe 11 to the indoor units 21 in the time period of the heating operation, and the refrigerant flows from the indoor units 21 to the first gas pipe 11 in the time period of the cooling operation. As described above, the refrigerant circulates in the opposite directions in the cooling and heating operations, and therefore there is a need to have control valves through which the effluent can flow in both bases. addresses. The typical opening / closing valves are directional, and it is necessary to have two opening and / or closing valves in parallel in order to circulate the refrigerant in both directions. Accordingly, the pipe switching units 22 become disadvantageously large in size. Therefore, as first control valves 43 and second control valves 42 of the piping switching units, in this embodiment electrically operated expansion valves are used that are similar to those used for expansion valves 31 and 4 and require little space. In this way, opening / closing operations can be performed in both directions.

In addition, in the case where the operations of the indoor units 20 are switched between heating and cooling operations, the conditions of the refrigerant located inside the indoor heat exchangers 30 vary dramatically between a high pressure and a low pressure and is generated. a noise caused by the flow of refrigerant, possibly thereby causing discomfort for users. As in the embodiment of this specification electrically operated expansion valves whose opening degrees can be arbitrarily adjusted are used, pressure changes can be prevented, compared to the case in which opening / closing valves are used, by means of the gradual increase in the degrees of openness in this case. In this way, it is possible to prevent the generation of noise caused by the refrigerant flow.

Additionally, Figure 8 shows an example configuration of a pipeline switching unit using a first pressure adjustment valve 45, a second pressure adjustment valve 44, and a capillary device 46, in addition to the first control valve 43 and of the second control valve configured by the electrically operated expansion valves. In this embodiment, by opening the first pressure adjustment valve 45 before increasing the degree of opening of the first control valve 43, the pressures of the indoor heat exchangers 30 and the first gas pipe 11 are they can gradually equalize through the capillary circuit 46. As the refrigerant gas flows to the first control valve43, a pressure drop that increases in comparison to the liquid refrigerant tends to occur. Therefore, it is necessary to use electrically operated expansion valves of large size with a small flow resistance. Consequently, there is a possibility that the pressures change too quickly in the pressure equalization operation. However, the capillary circuit 46 and the first pressure adjustment valve 45 are provided to circulate a small amount of refrigerant, and thus the pressures can be gradually equalized by using the first pressure valve 45. It should be noted that the electrically operated expansion valve is used for the first pressure adjustment valve 45 because the refrigerant flows in both directions.

For the second control valve 42, the noise of the coolant flow caused by both pressure can be similarly prevented by the disturbance of the second control valve 4 2 after gradually equalizing the pressures using the pressure second pressure adjustment valve 44. It should be noted that the capillary circuit 46 is shared to decrease the size in this embodiment.

Second embodiment

Next, a second embodiment of the present invention is described using Figure 9. The second embodiment is different from the first embodiment shown in Figure 1 in the sense that 3 outdoor units have been installed in parallel. However, the second embodiment is the same as the first embodiment shown in Figure 1 in the sense that the respective indoor units 20 a, 20b and 20c communicate with each other through a common liquid pipe 10. A first gas pipe 11, a second gas pipe 12, and a third gas pipe 13 connected to the respective outdoor units have been connected separately to the respective pipe switching units 22. In each of the pipe switching units 22, a first control valve 43, a second control valve 42 and a third control valve 41 are provided in the circuits communicated with the first gas pipe 11, second pipe 12 of gas, and third gas pipe 13, respectively, and the respective gas pipes 11, 12 and 13 are connected to the indoor units 21 by means of the respective control valves 43, 42 and 41, respectively.

Two indoor units 21 a and 21b are connected to perform a heating operation in the indoor unit 21 a and to perform a cooling operation in the indoor unit 21b of this embodiment. In addition, four-way valves 3 of the respective outdoor units 20 are switched such that they form a heat discharge cycle in the first outdoor unit 20 and to form a heat absorption cycle in the second outdoor unit 20b and in the third outdoor unit 20c.

A refrigerant gas supplied from the second outdoor unit 20 forming the heat absorbing circuit is supplied from the second gas pipe 12 to the indoor unit 21 a, through the second control valve 42. In addition, the refrigerant gas supplied from the outdoor unit 20c that forms the heat absorption cycle is supplied from the third gas pipe 13 to the indoor unit 21 through the third control valve 41. The refrigerant gases supplied from the respective outdoor units 20b and 20c, are joined, and then condensed and devolatilized by an internal heat exchanger 30 a before flowing to the common pipe 10.

In the indoor unit 21 which performs the cooling operation, after the refrigerant supplied from the common liquid pipe 10 is decompressed by means of an expansion valve 31, the resulting refrigerant is evaporated by means of an internal heat exchanger. ior 3 0b p to perform the cooling operation. The gasified refrigerant reaches the outdoor unit 20 which forms the heat discharge cycle through the first control valve 43 and the first gas pipe 11.

In the cooling cycle of this embodiment, the refrigerant compressed by the compressors 1 a, 1b and 1c is condensed by the first outdoor unit 20 to which the heat discharge operation is performed and by the indoor unit 21 to which it performs the operation heating Next, the condensed refrigerant is evaporated and gasified by the second outdoor unit 20b and the third outdoor unit 20c performing the heat absorption operation and the indoor unit 21b performing the heating operation before returning to the compressors .

In the indoor unit 21 that performs the heating operation, by opening the first control valve 42 a and the second control valve 43 a and by closing the third control valve 41 a, the indoor unit 21 a it communicates only with the second outdoor unit 20b and the third outdoor unit 20c through the second gas pipe 12 and the third gas pipe 13. On the other hand, in the indoor unit 21b that performs the cooling operation, by opening the third control valve 41b and closing the first control valve 42b and the second control valve 43b, only the pipe 32b of indoor gas and the first outdoor unit 20 a are communicated with each other.

As stated above, the opening / closing states of the respective control valves 41, 42 and 43 in the pipe switching units 22 are switched according to the operations of the outdoor units, such that it is possible provide the apparatus with a refrigeration cycle of the simultaneous cooling and heating type using the outdoor units in which the cooling operation and the heating operation can be performed in a switchable manner.

Claims (8)

1.A refrigeration cycle apparatus comprising: first and second outdoor units (20 a; 20b), each of which includes a compressor (1), an outdoor heat exchanger (2), a gas connection port (5), valves (3 ) channel switching through which channels can be arbitrarily switched in order to communicate one of an intake port and a discharge port of the compressor with the gas connection port (5) and communicate the other with a end of the outdoor heat exchanger (2), and a liquid connection port (6) connected to the other end of the outdoor heat exchanger (2); a plurality of indoor units (21 a; 21b; 21c) in which the indoor liquid pipes, indoor heat exchangers (30), and indoor gas pipes (32) are connected in order; Y a common liquid pipe (10) through which the liquid connection port of each outdoor unit (20 a; 20b) communicates with the indoor liquid pipes of the plurality of indoor units (21 a; 21b; 21c), where each of the indoor gas pipes (32) 32 in the respective indoor units (21 a; 21b; 21c) branches into a first gas pipe (11) and a second gas pipe (12), whose first Gas pipe (11) is connected to the gas connection port of one of the outdoor units (20 a), whose second pipe

(12)

 It is connected to the gas connection port of the other outdoor units (20 b), some units

(22)

 of pipe switching, each of which switches the respective channels of the first pipe

(eleven)

 of gas and the second pipe (12) of gas in each of the indoor units (21 a; 21b; 2 1c) characterized in that each of the indoor heat exchangers (30) is communicated with only one of the outdoor units (20 a; 20b) by switching the pipe switching units (22).

2. The refrigeration cycle apparatus according to claim 1, wherein when a cooling operation and a heating operation are performed simultaneously, one of the outdoor units (20 a; 20b) forms a heat absorption cycle by switching the pipe switching units (3) in order to communicating the discharge port of the compressor (1) with the gas connection port (5), and the other of the outdoor units (20b; 20 a) forms a discharge cycle by switching the units (3) of pipe switching in order to communicate the discharge port of the compressor (1) with the outdoor heat exchanger (2), The indoor unit (21 a; 21b; 21c) that performs the heating operation is switched by means of the pipe switching unit (3) in order to communicate with the outdoor unit (20 a; 20b) of the absorption cycle of heat, and The indoor unit (21 a; 21b; 21c) that performs the cooling operation is switched by means of the pipe switching unit (3) in order to communicate with the outdoor unit (20 a; 20b) of the discharge cycle of heat

3.

 The refrigeration cycle apparatus according to claim 2, wherein

between the first outdoor unit (20 a) and the second outdoor unit (20b) that form the heat absorption cycle or the heat discharge cycle, the cycles can be switched alternately, and the units (3) of Pipeline switching are switched according to the cycle switching.

Four.

 The refrigeration cycle apparatus according to claim 3, wherein

by means of the alternating switching of the cycles between the first outdoor unit (20 a) and the second outdoor unit (20b) a defrosting operation is performed for the outdoor heat exchanger (2) of the outdoor unit that forms the heat absorption cycle.

5.

 The refrigeration cycle apparatus according to any one of claims 2 to 4, wherein. while the capacity of the compressor (1) of the outdoor unit that forms the heat discharge cycle is controlled based on a required cooling load on the indoor unit (21 a; 21b; 21c) it performs the cooling operation, the capacity of the compressor (1) in the outdoor unit (20 a; 20b) that forms the heat absorption cycle is controlled based on a required heating load of the indoor unit (21 a; 21b; 21c) that performs the heating operation.

6.

 The refrigeration cycle apparatus according to any one of claims 2 to 5, wherein

7.

 The refrigeration cycle apparatus according to claim 1, wherein

The first control valves (43) and the second control valves (42) are electrically operated expansion valves. when the cooling operation or the heating operation is performed, the outdoor units (20 a; 20b) that are communicated with the respective indoor units (21 a; 21b; 21c) can be switched using the pipe switching units . 8. The refrigeration cycle apparatus according to claim 7, wherein a switching function has been provided for the indoor units (21 a; 21b; 21c) that communicate with the respective outdoor units (20 a; 20b) based on the capacity information of each indoor unit (21 a ; 21b; 21c) and at the intake air temperature.