WO2019123631A1

WO2019123631A1 - Air conditioner

Info

Publication number: WO2019123631A1
Application number: PCT/JP2017/046131
Authority: WO
Inventors: 杉本　猛; 山口　敏明; 坂本　英仁; ▲高▼田　茂生
Original assignee: 三菱電機株式会社; 三菱電機冷熱応用システム株式会社
Priority date: 2017-12-22
Filing date: 2017-12-22
Publication date: 2019-06-27
Also published as: JPWO2019123631A1

Abstract

The purpose of the present invention is to provide an air conditioner in which safety with respect to leakage of refrigerant is improved. This air conditioner is provided with: a refrigerant circuit in which a compressor, a heat-source-side heat exchanger, a throttle part, and a load-side heat exchanger are connected by refrigerant piping, there being a refrigerant circulating through the interior of the refrigerant circuit; a load-side blower that supplies indoor air to the load-side heat exchanger; and a casing that accommodates the refrigerant circuit and the load-side blower; the refrigerant being a flammable refrigerant that has a global warming potential of 750 or less.

Description

Air conditioner

The present invention relates to an air conditioner applied to, for example, a large building.

As an air conditioning apparatus applied to a large building, an air conditioning apparatus in which a plurality of indoor side heat exchangers are connected to one compressor and an outdoor side heat exchanger is known. In such an air conditioner, an outdoor unit in which a compressor and an outdoor heat exchanger are installed, and a plurality of indoor units in which an expansion device and an indoor heat exchanger are installed in pairs. Are connected by a refrigerant pipe (for example, Patent Document 1).

Patent No. 3866359 gazette

The Fluorocarbons Emission Control Act, which came into effect in April 2015, stipulates that the global warming potential of refrigerants used in air conditioners for stores or office air conditioners must be 750 or less by 2020. . In the air conditioner of Patent Document 1, the air conditioner of Patent Document 1 has a hydrofluorocarbon-based refrigerant, for example, R410A, but the global warming potential of R410A is 2090. It is higher than the value specified in the Emission Control Act.

Building multi air conditioners applied to large buildings are also expected to become designated products that use refrigerants with global warming potentials of 750 or less. In addition, since the European F-gas regulation makes Quota procurement difficult after 2018 in Europe, refrigerants used in air conditioners applied to large buildings are also required to rapidly reduce the global warming potential. Need to be realized.

In the air conditioner of Patent Document 1, when propane is used as a refrigerant instead of R410A, since the global warming potential of propane is 3.3, it conforms to the numerical value specified in the Freon Emissions Control Act. However, when propane is used as a refrigerant in the air conditioner of Patent Document 1, a plurality of indoor units are connected to the outdoor unit, so the amount of propane sealed in the air conditioner is several tens kg become. As the amount of propane, which is a flammable refrigerant, increases, if a refrigerant leak occurs in the air conditioner, a large amount of refrigerant may accumulate in the air conditioner or in a space where it is installed, leading to the combustion concentration of the refrigerant. Get higher. Therefore, in the air conditioner of Patent Document 1, there is a problem that safety against refrigerant leakage can not be secured when a flammable refrigerant such as propane or the like having a global warming potential of 750 or less is used.

An object of the present invention is to provide an air conditioner that ensures safety against refrigerant leakage even when a flammable refrigerant such as propane or the like having a global warming potential of 750 or less is used.

The air conditioner according to the present invention is a refrigerant circuit in which a compressor, a heat source side heat exchanger that is a water-cooled heat exchanger, a throttling portion, and a load side heat exchanger are connected by piping and the refrigerant circulates inside; A load-side fan for supplying room air to the load-side heat exchanger, and a case for housing the refrigerant circuit and the load-side fan. The refrigerant is a flammable refrigerant having a global warming potential of 750 or less. is there.

According to the air conditioning apparatus according to the present invention, since the filling amount of the refrigerant can be reduced, safety against refrigerant leakage can be ensured even if a flammable refrigerant is used. Moreover, since the refrigerant used for an air conditioning apparatus can use the thing whose global warming potential is 750 or less, it can provide the air conditioning apparatus which adapted the freon discharge control.

FIG. 1 is a schematic refrigerant circuit diagram showing an example of an air conditioning apparatus according to Embodiment 1. It is the schematic which shows the internal structure which looked at the air conditioning apparatus which concerns on Embodiment 1 from the side. It is the schematic which shows the external appearance structure which looked at the air conditioning apparatus which concerns on Embodiment 1 from the lower surface. FIG. 2 is a refrigerant circuit diagram of an air conditioner as a comparative example of the air conditioner according to Embodiment 1. FIG. 7 is a schematic refrigerant circuit diagram showing an example of an air conditioning apparatus according to Embodiment 2. FIG. 13 is a schematic view showing an example of a heat source side heat exchanger used in the air conditioning apparatus according to Embodiment 3. FIG. 16 is a schematic view showing an example of a heat source side heat exchanger used in the air conditioning apparatus according to Embodiment 4. It is the schematic which shows the internal structure which looked at the air conditioning apparatus which concerns on Embodiment 5 from the front.

Embodiment 1
An air conditioner 1 according to Embodiment 1 will be described. FIG. 1 is a schematic refrigerant circuit diagram showing an example of the air conditioning apparatus 1 according to the first embodiment. In the following drawings including FIG. 1, the dimensions, shapes, and arrangements of the respective constituent members may differ from actual ones. Further, in the following drawings, the same or similar members or parts are denoted by the same reference numerals, or the reference numerals are omitted.

As shown in FIG. 1, in the air conditioner 1 according to the first embodiment, the compressor 2, the heat source side heat exchanger 3, the throttling portion 4, and the load side heat exchanger 5 are connected by refrigerant piping, A refrigerant circuit 6 in which the refrigerant circulates is provided. The air conditioning apparatus 1 also includes a load-side blower 7 that supplies room air to the load-side heat exchanger 5.

The compressor 2 is a fluid machine that compresses low-pressure refrigerant that has been taken in and discharges it as high-pressure refrigerant. The compressor 2 can be configured, for example, as a rotary compressor or a scroll compressor. The compressor 2 may be configured as, for example, a compressor having a constant rotational frequency, or may be configured as a compressor capable of controlling a rotational frequency on which an inverter is mounted.

The heat source side heat exchanger 3 is a heat exchanger that functions as a condenser. As shown in FIG. 1, the heat source side heat exchanger 3 is, for example, between the high pressure refrigerant flowing inside the heat source side heat exchanger 3 discharged from the compressor 2 and the heat medium circulating the heat medium circuit 8. Can be configured as a water-cooled heat exchanger capable of performing heat exchange. When the heat source side heat exchanger 3 can be configured as a water-cooled heat exchanger, for example, a plate type heat exchanger or a double-pipe heat exchanger can be adopted. Further, as the heat medium circulating through the heat medium circuit 8, a liquid medium such as water or brine is used. In the air conditioner 1, the condenser may be also referred to as a radiator.

Although not shown, the heat medium circuit 8 includes a cooling tower installed outside and an outlet side of the heat medium of the cooling tower and an inlet side of the heat medium of the heat source side heat exchanger 3. The water-cooling pump arranged at is connected by piping. The cooling tower is a heat exchange device that cools the heat medium in direct or indirect contact with the atmosphere. The water-cooling pump is a fluid machine that sucks the heat medium from the cooling tower and presses the sucked heat medium into the heat source side heat exchanger 3.

By configuring the heat source side heat exchanger 3 as a water-cooled heat exchanger, the exhaust heat treatment can be easily performed in the cooling tower, and the air conditioner 1 needs to be provided with a duct or the like for performing the exhaust heat treatment. It disappears. Therefore, by configuring the heat source side heat exchanger 3 as a water-cooled heat exchanger, the configuration of the air conditioner 1 can be miniaturized and simplified. In addition, since the heat source side heat exchanger 3 is configured as a water-cooled heat exchanger, the discharge of heat to the atmosphere is minimized, so that the heat island phenomenon can be suppressed.

The throttling unit 4 expands and reduces the pressure of the high pressure liquid refrigerant flowing out of the heat source side heat exchanger 3 and causes the high pressure liquid refrigerant to flow into the load side heat exchanger 5. The throttling unit 4 is configured of, for example, an expander, which is a mechanical expansion valve, or a pressure reducing device such as a linear electronic expansion valve whose opening degree can be adjusted in multiple stages or continuously. The throttling unit 4 may be configured by a capillary tube. The linear electronic expansion valve is also abbreviated as LEV.

The load side heat exchanger 5 is a heat exchanger that functions as an evaporator. In the load-side heat exchanger 5, the refrigerant expanded and decompressed in the throttling unit 4 flows in. The load side heat exchanger 5 is, for example, an air-cooled heat exchanger in which heat exchange is performed between the two-phase refrigerant flowing inside and the indoor air supplied to the load side heat exchanger 5 by the load side blower 7. is there. The load-side heat exchanger 5 can be configured, for example, as a cross fin type fin-and-tube heat exchanger composed of a heat transfer tube and a plurality of fins, or a plate fin type heat exchanger. In the air conditioner 1, the evaporator may be also referred to as a cooler.

The load-side blower 7 attracts indoor air by the rotational drive of the load-side blower 7 and supplies the indoor air to the load-side heat exchanger 5. The load-side blower 7 can be configured as, for example, a centrifugal fan such as a sirocco fan or a turbo fan, a cross flow fan, a diagonal flow fan, or a propeller fan.

FIG. 2 is a schematic view showing an internal configuration of the air conditioning apparatus 1 according to Embodiment 1 as viewed from the side. FIG. 3 is a schematic view showing an appearance of the air conditioning apparatus 1 according to Embodiment 1 as viewed from the lower surface. Next, the structure of the air conditioning apparatus 1 which concerns on this Embodiment 1 is demonstrated using FIG.2 and FIG.3.

As shown in FIG. 2, the air conditioning apparatus 1 accommodates the refrigerant circuit 6 and the load-side blower 7, and is attached to the housing 10 disposed on the ceiling 150 and the housing 10. And a panel 11 disposed on the ceiling cassette.

In the housing 10, the compressor 2, the heat source side heat exchanger 3, the throttle unit 4, the first load side heat exchanger 5a, the second load side heat exchanger 5b, the first load side fan 7a, and A second load-side blower 7b is accommodated. The compressor 2, the heat source side heat exchanger 3, the first load side heat exchanger 5 a, and the second load side heat exchanger 5 b are connected by a refrigerant pipe together with the throttling portion 4 to form a refrigerant circuit 6. There is. In addition, in FIG. 2, the refrigerant | coolant piping which comprises the aperture | diaphragm | squeeze part 4 and the refrigerant circuit 6 is not shown in figure.

The housing 10 is provided with a first suction introduction guide 12a and a second suction introduction guide 12b. The first suction introduction guide 12a is disposed inside the housing 10, and constitutes a first suction air passage 13a for inducing room air by driving the first load-side fan 7a. The second suction introduction guide 12b is disposed inside the housing 10, and constitutes a second suction air passage 13b for inducing room air by driving the first load-side fan 7a. In addition, as shown in FIG. 2, in the space between the first suction introduction guide 12a and the second suction introduction guide 12b, a compressor 2, a heat source side heat exchanger 3 and the like are disposed as a machine room. .

A first blowout air passage 14a for supplying the air heat-exchanged by the first load-side heat exchanger 5a to the room 100 is provided outside the first suction air passage 13a. Moreover, the 2nd blowing air path 14b for supplying the air heat-exchanged with the 2nd load side heat exchanger 5b to the room | chamber interior 100 is provided in the outer side of the 2nd suction introduction guide 12b. The first blowoff air passage 14a and the second blowoff air passage 14b may be configured by arranging a duct or a chamber outside the housing 10, or by providing a partition plate inside the housing 10 May be

As shown in FIGS. 2 and 3, the panel 11 is provided with a first inlet 15a, a second inlet 15b, a first outlet 16a, and a second outlet 16b. The first suction port 15 a and the second suction port 15 b are configured as, for example, rectangular openings, and are arranged along opposing sides on the panel 11. The first suction port 15 a takes in room air into the interior of the housing 10 by the drive of the first load-side blower 7 a. The second suction port 15 b takes in room air into the inside of the housing 10 by the drive of the second load-side blower 7 b. The first blowout port 16a is configured as, for example, a rectangular opening, and is disposed outside the first suction port 15a. The first air outlet 16a supplies the air heat-exchanged by the first load-side heat exchanger 5a to the blowout chamber 100. The second air outlet 16b is configured as, for example, a rectangular opening, and is disposed outside the second inlet 15b. The second outlet 16b supplies the air heat-exchanged by the second load-side heat exchanger 5b to the blowout chamber 100.

In addition, in FIG. 2, although the 1st load side heat exchanger 5a and the 2nd load side heat exchanger 5b are comprised as another body, the load of a U-shape or O-shape, for example, when it sees from upper direction It may be integrated as the side heat exchanger 5. Moreover, although it is set as the structure which provided the inlet port 15 and the blower outlet 16 two each in the panel 11 in FIG.2 and FIG.3, for example, the inlet port 15 and the blower outlet 16 are provided in each edge of the panel 11. It is good also as composition.

Next, a refrigerant that is a working fluid of the air conditioning apparatus 1 according to Embodiment 1 will be described.

In the air conditioning apparatus 1 according to the first embodiment, a flammable refrigerant having a global warming potential of 750 or less is used as the working fluid, for example, propane and isobutane. Propane is a refrigerant having a global warming potential of 3.3. Isobutane is a refrigerant having a global warming potential of 4. In the technical field, the global warming potential is also abbreviated as GWP.

The air conditioner 1 of the first embodiment has a housing 10 that has a refrigerant circuit in which a compressor 2, a heat source side heat exchanger 3, a throttling unit 4, a load side heat exchanger 5, and a load side blower 7 are connected by refrigerant piping. Integrated in one unit. Therefore, it is possible to miniaturize, that is, to shorten the configuration of the refrigerant circuit, and to reduce the filling amount of the refrigerant. For example, in the case of propane, since the liquid density is small, the filling amount of the refrigerant can be reduced to about 500 g. Therefore, the air conditioner 1 can ensure the safety against the leakage of the refrigerant even when the flammable refrigerant having the global warming potential of 750 or less is used.

Further, the filling amount M [kg] of the refrigerant in the air conditioner 1 is a numerical value obtained by dividing the volume [m ³ ] when the refrigerant having the filling amount M turns into a gas by the volume V [m ³ ] of the room 100 It is adjusted to be equal to or less than a quarter of the lower limit value LFL of the combustion range of the room 100. That is, the filling amount M of the refrigerant of the air conditioner 1 is adjusted to satisfy the relationship of M / V ≦ LFL / 4. The lower limit value LFL of the combustion range is set to, for example, 1.8 [vol%]. Since the air conditioner 1 according to Embodiment 1 has a small amount of refrigerant filling of about 500 g, even when the refrigerant leaks, it is possible to prevent the refrigerant concentration in the room 100 from reaching the combustion concentration of the refrigerant.

Next, the operation of the air conditioning apparatus 1 according to Embodiment 1 will be described using FIGS. The flow of the refrigerant in FIG. 1 is indicated by an arrow above the refrigerant circuit 6, and the flow of the heat medium flowing through the heat source side heat exchanger 3 is indicated by an arrow above the heat medium circuit 8. . Also, the flow of air in FIG. 2 is indicated by arrows.

When the air conditioner 1 is driven, the high-temperature and high-pressure gas refrigerant discharged from the compressor 2 flows into the heat source side heat exchanger 3. The high temperature / high pressure gas refrigerant flowing into the heat source side heat exchanger 3 is heat-exchanged by releasing heat to the heat medium which is a low temperature medium, and becomes a high pressure liquid refrigerant. The high pressure liquid refrigerant flows into the throttling unit 4. The high-pressure liquid refrigerant flowing into the throttling unit 4 is expanded and reduced in pressure to become a low-temperature low-pressure two-phase refrigerant. The low-temperature low-pressure two-phase refrigerant flows into the first load-side heat exchanger 5a and the second load-side heat exchanger 5b, and the first load-side heat exchanger 5a and the second load-side heat exchanger 5b The heat is absorbed from the room air supplied to the air and evaporated to be a highly dry two-phase refrigerant or a low-temperature low-pressure gas refrigerant. The highly dry two-phase refrigerant or the low-temperature low-pressure gas refrigerant flowing out of the first load-side heat exchanger 5 a and the second load-side heat exchanger 5 b is sucked into the compressor 2. In the air conditioner 1 according to the first embodiment, the above cycle is repeated to perform the cooling operation. Here, the "cooling operation" refers to an operation of supplying a low-temperature low-pressure refrigerant to the first load-side heat exchanger 5a and the second load-side heat exchanger 5b.

When the cooling operation is performed by the air conditioner 1, the indoor air is attracted to the first suction air passage 13a via the first suction port 15a by the driving of the first load-side blower 7a. The induced indoor air is supplied to the first load-side heat exchanger 5a by the first load-side blower 7a. The room air supplied to the first load side heat exchanger 5a is subjected to heat exchange with the first load side heat exchanger 5a, and heat is released from the room air. Air from which heat has been released passes through the first blowoff air passage 14a and is supplied to the room 100 through the first blowout port 16a. Similarly, the room air is attracted to the second suction air passage 13b through the second suction port 15b by the drive of the second load-side blower 7b. The induced indoor air is supplied to the second load-side heat exchanger 5b by the second load-side blower 7b. The room air supplied to the second load-side heat exchanger 5b is subjected to heat exchange with the second load-side heat exchanger 5b, and heat is released from the room air. The air from which the heat has been released passes through the second air outlet 14b and is supplied to the room 100 through the second air outlet 16b. The first suction port 15a and the second suction port 15b are also referred to as the "suction port", and the first blowout port 16a and the second blowout port 16b are also referred to as the "blowing port". The air passage from the first inlet 15a to the first outlet 16a and the air passage from the second inlet 15b to the second outlet 16b are also referred to as "main air passages".

In the configuration of the main air path of the air conditioner 1 described above, the load-side fan 7 and the compressor 2 are disposed on the windward side of the load-side heat exchanger 5. In addition, although not shown, the control box containing the control device for controlling the compressor 2, the throttling portion 4 and the load-side fan 7 provided in the air conditioner 1 also includes the load-side heat exchanger 5 in the air passage. Installed on the windward side of Alternatively, the control box and the compressor 2 may be installed outside the air path. In the air conditioner 1, refrigerant leakage may occur from the load

side heat exchangers

5a and 5b. Therefore, on the downwind side of the load

side heat exchangers

5a and 5b in the main air path, that is, on the outlet 16 side of the load

side heat exchangers

5a and 5b, electrical components such as the load side blower 7, the compressor 2 and the control box When arranged, the flammable refrigerant that has leaked can easily touch the electrical components. Since the combustible refrigerant may burn when it contacts the electric parts, by arranging the load-side blower 7, the compressor 2 and the control box on the windward side of the load-

side heat exchangers

5a and 5b as described above It is possible to prevent the leaked refrigerant from burning.

FIG. 4 is a refrigerant circuit diagram of an air conditioning apparatus 101 as a comparative example of the air conditioning apparatus 1 according to the first embodiment. In the air conditioner 101 of the comparative example, the heat source side heat exchanger 104 is installed in the outdoor unit 103, and the load side heat exchanger 105 is installed in the indoor unit 102. The indoor unit 102 and the outdoor unit 103 are connected by extension pipes 111 and 112. Depending on the size of the building, the extension pipes 111 and 112 may have a length of about 100 m, and as the extension pipes 111 and 112 become longer, the amount of refrigerant charged in the refrigerant circuit 106 of the air conditioner 101 is large. Become. In such an air conditioning apparatus 101, when refrigerant leakage occurs in the indoor unit 102, a large amount of refrigerant may flow out into the room 100, and the discharged refrigerant may reach the combustion concentration of the refrigerant in the room 100.

On the other hand, in the air conditioner 1 according to the first embodiment, the refrigerant circuit 6 is accommodated in the case 10 installed on the ceiling 150 in the room. Therefore, the length of the piping of the air conditioning apparatus 1 is short compared to the air conditioning apparatus 101 of the comparative example. Therefore, the amount of refrigerant charged into the refrigerant circuit 6 is also small, and even when refrigerant leakage occurs, the absolute amount of refrigerant flowing out into the room 100 is small, so the possibility of reaching the combustion concentration of the refrigerant is low. Become.

According to the above-described configuration, since the integrated air conditioning apparatus 1 can be provided, the air conditioning apparatus 1 can be miniaturized, and the filling amount of the refrigerant can be reduced. Therefore, according to the air conditioning apparatus 1 according to Embodiment 1, even when the flammable refrigerant having a global warming potential of 750 or less is used, the safety against the leakage of the refrigerant can be secured. Moreover, since the air conditioning apparatus 1 can be miniaturized, the packaging of the product can be miniaturized and the transportation of the product can be made more efficient.

In addition, since the air conditioner 1 according to the first embodiment is the integrated air conditioner 1, the indoor unit 102 and the outdoor unit 103 are separated as in the air conditioner 101 according to the comparative example. It is not necessary to provide the extension pipes 111 and 112 connecting the 102 and the outdoor unit 103. When the indoor unit 102 and the outdoor unit 103 are separated as in the air conditioner 101 according to the comparative example, since the extension pipes 111 and 112 may have a length of about 100 m, the cooling capacity may be reduced due to pressure loss or Compressor damage may occur due to refrigeration oil return failure. However, the air conditioner 1 according to the first embodiment does not need to provide the extension pipes 111 and 112, so that it is possible to avoid the compressor damage due to the decrease of the cooling capacity due to pressure loss or the return failure of the refrigerator oil. The reliability and safety of the conditioner 1 can be ensured.

Moreover, in the air conditioning apparatus 1 which concerns on Embodiment 1, the housing | casing 10 can be comprised as a ceiling cassette type, and a refrigerant | coolant can be made into propane or isobutane. Although propane or isobutane, which is a flammable refrigerant, is employed as the refrigerant of the air conditioner 1, the air conditioner 1 capable of ensuring the safety against leakage of the refrigerant can be provided because the filling amount of the refrigerant can be suppressed to about 500 g or less. can do.

In addition, when the indoor unit 102 and the outdoor unit 103 are separated, a machine room must be provided in the building to increase the number of outdoor units 103, etc., which makes it difficult to select an installation location. is there. However, since the air conditioning apparatus 1 according to the first embodiment is the integrated air conditioning apparatus 1 and can be configured as a ceiling cassette type apparatus that can be accommodated in the ceiling and back 150, the installation location of the air conditioning apparatus 1 can be It can be easily selected.

In the air conditioner 1 according to the first embodiment, the heat source side heat exchanger 3 is a water-cooled heat exchanger that performs heat exchange between the refrigerant and the heat medium, and the heat medium is water or brine. Can be configured.

By configuring the heat source side heat exchanger 3 as a water-cooled heat exchanger, the heat absorbed from the refrigerant by the heat medium can be easily exhausted in the cooling tower. Therefore, it is not necessary to provide the air conditioner 1 with a duct or the like for performing the exhaust heat treatment. Therefore, by configuring the heat source side heat exchanger 3 as a water-cooled heat exchanger, the configuration of the air conditioner 1 can be miniaturized and simplified. In addition, since the heat source side heat exchanger 3 is configured as a water-cooled heat exchanger, the discharge of heat to the atmosphere is suppressed to the minimum, so the heat island phenomenon can be suppressed. Moreover, the safety | security of the air conditioning apparatus 1 is securable by making a heat medium into water or a brine.

Further, in the air conditioning apparatus 1 according to the first embodiment, the filling amount M of the refrigerant is a value obtained by dividing the volume when the refrigerant of the filling amount M turns into a gas at room temperature by the volume of the indoor 100 is the indoor 100 It is adjusted so as to be less than or equal to one-fourth of the lower limit value of the combustion range. Thus, even when the refrigerant leaks into the room 100, the refrigerant concentration in the room 100 can be prevented from reaching the combustion concentration of the refrigerant.

Second Embodiment
The second embodiment will be described with reference to FIG. FIG. 5 is a schematic refrigerant circuit diagram showing an example of the air conditioning apparatus 1 according to Embodiment 2. As shown in FIG.

In FIG. 5, the flow of the refrigerant during the cooling operation is indicated by a black arrow, and the flow of the refrigerant during the heating operation is indicated by a white block arrow. Further, in FIG. 5, the flow of the heat medium flowing through the heat source side heat exchanger 3 is indicated by an arrow above the heat medium circuit 8. Here, the “heating operation” is an operation of supplying the high-temperature high-pressure refrigerant to the load-side heat exchanger 5.

Embodiment 2 is a modification of the air conditioning apparatus 1 according to Embodiment 1 described above, in which a refrigerant flow switching device 9 is connected to the refrigerant circuit 6 of the air conditioning apparatus 1. For example, a four-way valve is used as the refrigerant flow switching device 9.

During the cooling operation, the refrigerant flow switching device 9 sucks the two-phase refrigerant having high dryness or the low-temperature low-pressure gas refrigerant from the load-side heat exchanger 5 into the compressor 2 and discharges the high-temperature high-pressure refrigerant discharged from the compressor 2. In order to cause the gas refrigerant to flow into the heat source side heat exchanger 3, path control of the refrigerant flow path is performed. Further, during the heating operation, the refrigerant flow switching device 9 causes the compressor 2 to suck the two-phase refrigerant having high dryness or the low-temperature low-pressure gas refrigerant from the heat source side heat exchanger 3, and the high temperature discharged from the compressor 2 The path control of the refrigerant flow path is performed so that the high-pressure gas refrigerant flows into the load-side heat exchanger 5.

According to the second embodiment, it is possible to provide the miniaturized air conditioner 1 capable of switching between the cooling operation and the heating operation.

A two-way valve or a three-way valve may be used as the refrigerant flow switching device 9.

Third Embodiment
The third embodiment will be described with reference to FIG. FIG. 6 is a schematic view showing an example of the heat source side heat exchanger 3 used in the air conditioning apparatus 1 according to the third embodiment. FIG. 6 shows a cross section perpendicular to the flow direction of the refrigerant and the heat medium flowing in the heat source side heat exchanger 3 of the heat source side heat exchanger 3.

The air conditioner 1 of the third embodiment is a modification of the first embodiment and the second embodiment described above, and employs a water-cooled heat exchanger as the heat source side heat exchanger 3 and doubles the water-cooled heat exchanger. It is configured as a tube heat exchanger.

The heat source side heat exchanger 3 of the air conditioner 1 according to the third embodiment is a double-pipe heat exchanger 20 having an inner pipe 20a and an outer pipe 20b, and the refrigerant flows through the inner pipe 20a. It is comprised so that a heat carrier may be poured between outer tube 20b. In the double pipe heat exchanger 20, heat exchange is performed between the refrigerant and the heat medium via the circumferential surface of the inner pipe 20a. As shown in FIG. 6, the double-pipe heat exchanger 20 is configured such that the circumferential surface of the inner pipe 20a and the circumferential surface of the outer pipe 20b are concentric in the cross section of the pipe.

According to the third embodiment, even if the refrigerant leaks in the inner pipe 20a of the double-pipe heat exchanger 20, the leaked refrigerant is mixed with the heat medium flowing between the inner pipe 20a and the outer pipe 20b. It will be discharged outside with the heat medium. In the heat source side heat exchanger 3, the amount of refrigerant may be the largest at the time of driving the air conditioner 1, but according to the third embodiment, since the leaked refrigerant does not leak into the room 100, the air The safety of the conditioning device 1 can be secured.

Fourth Embodiment
The fourth embodiment will be described with reference to FIG. FIG. 7 is a schematic view showing an example of the heat source side heat exchanger 3 used in the air conditioning apparatus 1 according to Embodiment 4. As shown in FIG. The air conditioner 1 of the fourth embodiment adopts a water-cooled heat exchanger as the heat source side heat exchanger 3 and configures the water-cooled heat exchanger as a plate heat exchanger 30.

The heat source side heat exchanger 3 of the air conditioning apparatus 1 of Embodiment 4 is covered with a sealing member 30 b so as to seal the periphery of the plate heat exchanger main body 30 a. According to the fourth embodiment, even if the refrigerant leaks from the plate heat exchanger main body 30a, since the sealing member 30b covers the refrigerant, the leaking refrigerant is accumulated in the sealing member 30b. Since the space above the ceiling has a smaller volume than the space in the room 100, when the refrigerant leaks, it tends to reach the combustion concentration. However, since the leaked refrigerant remains in the sealing member 30b, the refrigerant does not leak to the space of the ceiling 150 on which the housing 10 of the air conditioning apparatus 1 is disposed, so the safety of the air conditioning apparatus 1 Can be secured.

Embodiment 5
The fifth embodiment will be described with reference to FIG. FIG. 8 is a schematic view showing an internal configuration of the air conditioning apparatus 1 according to Embodiment 5 as viewed from the front. In FIG. 8, the flow of air in the air conditioner 1 is indicated by an arrow.

In the fifth embodiment, the air conditioner 1 is configured as a ceiling-embedded device, and the other configurations are the same as the air conditioner of the first embodiment described above. In the air conditioner 1 of the fifth embodiment, the housing 10 is arranged to be embedded in the ceiling and back 150. Further, the suction side chamber 17a and the blowout side chamber 17b are arranged to connect the housing 10 and the room 100 with each other. Moreover, the suction side panel 11a is arrange | positioned at the indoor 100 side of the suction side chamber 17a, and the blowing side panel 11b is arrange | positioned at the indoor 100 side of the blowing side chamber 17b. The air passage from the suction side panel 11a to the blowout side panel 11b corresponds to the "main air passage". In the air conditioner 1 according to the fifth embodiment, the refrigerant circuit 6 and the load-side blower 7 inside the housing 10, that is, the compressor 2, the throttle portion 4, the load-side heat exchanger 5, and the load-side blower 7 are accommodated. It is done. In addition, in FIG. 8, the refrigerant | coolant piping which comprises a throttle part and the refrigerant circuit 6 is not shown in figure. Further, in the main air path in the housing 10, the load-side blower 7, the compressor 2, and the control box are disposed on the windward side of the load-side heat exchanger 5. The control box may be located outside the air path.

Further, the heat source side heat exchanger 3 may also be installed in the main air passage of the air conditioner 1. Since the heat source side heat exchanger 3 is not an electrical component, it may be disposed on either the windward side or the windward side of the load side heat exchanger 5. However, since the heat source side heat exchanger 3 may leak refrigerant, it is desirable that the heat source side heat exchanger 3 be located on the downwind side of the compressor 2, the load side blower 7 or the control box. In the fifth embodiment, as in the ceiling cassette type air conditioner 1 of the above-mentioned first embodiment, an integrated air conditioner 1 capable of downsizing can be provided.

Other Embodiments
The present invention is not limited to the above-described embodiment, and various modifications are possible. For example, the air conditioner 1 of the above-described embodiment may be configured to include other components such as an accumulator, an oil separator, and a control device.

Further, the above-described embodiments can be used in combination with each other.

Reference Signs List 1 air conditioner, 2 compressor, 3 heat source side heat exchanger, 4 throttle portion, 5 load side heat exchanger, 5a (first) load side heat exchanger, 5b (second) load side heat exchanger , 6 refrigerant circuit, 7 load side fan, 7a first load side fan, 7b second load side fan, 8 heat medium circuit, 9 refrigerant flow switching device, 10 case, 11 panel, 11a suction side panel, 11b blowout side panel, 12a first suction introduction guide, 12b second suction introduction guide, 13a first suction air passage, 13b second suction air passage, 14a first blow air passage, 14b second blowout Air passage, 15 inlet, 15a first inlet, 15b second inlet, 16 outlet, 16a first outlet, 16b second outlet, 17a suction side chamber, 17b outlet side chamber, 20Double pipe heat exchanger, 20a inner pipe, 20b outer pipe, 30 plate heat exchanger, 30a plate heat exchanger main body, 30b sealing member, 100 indoors, 101 air conditioners, 102 indoor units, 103 outdoor units, 104 heat source side Heat exchanger, 105 Load side heat exchanger, 106 refrigerant circuit, 111 extension piping, 112 extension piping, 150 ceiling lining, 200 ceiling surface, LFL lower limit value, M filling amount.

Claims

A refrigerant circuit in which a compressor, a heat source side heat exchanger that is a water cooling type heat exchanger, a throttle unit, and a load side heat exchanger are connected by piping and a refrigerant circulates inside;
A load-side fan that supplies room air to the load-side heat exchanger;
A housing that houses the refrigerant circuit and the load-side fan;
The refrigerant is
An air conditioner that is a flammable refrigerant with a global warming potential of 750 or less.
The refrigerant is
The air conditioner according to claim 1, which is propane or isobutane.
The housing is
It has an inlet for taking in external air and an outlet for blowing air to the outside,
The load-side fan and the load-side heat exchanger are disposed in a main air path extending from the inlet to the outlet.
The load side heat exchanger
The air conditioning apparatus according to claim 1, wherein the air conditioner is disposed closer to the air outlet than the load-side fan in the main air passage.
A control box containing a control device for controlling the compressor and the load-side fan;
The control box is
The air conditioning apparatus according to claim 3, wherein the air conditioner is disposed closer to the suction port than the load-side heat exchanger in the main air passage.
A control box containing a control device for controlling the compressor and the load-side fan;
The control box is
The air conditioner according to claim 3, wherein the air conditioner is installed outside the main air passage.
The compressor is
The air conditioner according to any one of claims 3 to 5, wherein the air conditioner is disposed closer to the suction port than the load-side fan in the main air passage.
The heat source side heat exchanger is
The air conditioner according to any one of claims 3 to 6, which is installed in the main air passage.
The heat source side heat exchanger is
A double-pipe heat exchanger having an inner pipe and an outer pipe, wherein the refrigerant flows through the inner pipe, and a heat medium is caused to flow between the inner pipe and the outer pipe. The air conditioning apparatus according to any one of 7.
The heat source side heat exchanger is
The air conditioner according to any one of claims 1 to 7, which is a plate heat exchanger and is surrounded by a sealing member.
The refrigerant circuit is
The air conditioner according to any one of claims 1 to 9, wherein a refrigerant flow switching device is further connected.
The filling amount of the refrigerant is
The air conditioner according to any one of claims 1 to 10, wherein a numerical value obtained by dividing the filling amount by the volume of the room is equal to or less than a quarter of the lower limit value of the combustion range in the room.
The air conditioner according to any one of claims 1 to 11, wherein the housing is configured to be embedded in a ceiling.
The housing is
The air conditioner according to any one of claims 1 to 12, which is of a ceiling cassette type.