JP2018009780A - Air conditioner - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress accumulation of refrigeration machine oil in a heat source side heat exchanger.SOLUTION: A heat source side heat exchanger (23) includes a first refrigerant connection pipe (23a) and a second refrigerant connection pipe (23b) and is configured so that a refrigerant flowing in from the first refrigerant connection pipe (23a) flows from an upper side to a lower side in the heat source side heat exchanger (23) and flows out from the second refrigerant connection pipe (23b). A refrigerant circuit (20) has a heat source side circuit section (30) including the heat source side heat exchanger (23). The heat source side circuit section (30) is configured so that a flowing direction of the refrigerant passing through the heat source side heat exchanger (23) becomes a direction from the first refrigerant connection pipe (23a) toward the second refrigerant connection pipe (23b) during a cooling operation and a heating operation.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an air conditioner.

  Conventionally, an air conditioner including a refrigerant circuit that performs a refrigeration cycle is known. For example, Patent Literature 1 includes an air conditioner that performs a cooling operation that includes a refrigerant circuit having a compressor, a condenser (heat source side heat exchanger), an expansion mechanism, and an evaporator (use side heat exchanger) to cool the cabin. An apparatus is disclosed. Moreover, in the air conditioner of patent document 1, the condenser is comprised with the shell and tube type heat exchanger. Specifically, the condenser includes a shell formed in a cylindrical shape and a plurality of heat transfer tubes provided inside the shell. A refrigerant inlet pipe is provided at the upper part of the shell, and a refrigerant outlet pipe is provided at the lower part of the shell. The refrigerant that has flowed into the shell from the refrigerant inlet pipe flows from the upper side to the lower side of the shell and flows out from the refrigerant outlet pipe. The refrigerant flowing from the top to the bottom in the shell is cooled by exchanging heat with the cooling water flowing through the plurality of heat transfer tubes.

JP 2012-136152 A

  Incidentally, in an air conditioner having a refrigerant circuit having a compressor, a heat source side heat exchanger, an expansion mechanism, and a use side heat exchanger, the heat source side heat exchanger becomes a condenser and the use side heat exchanger becomes an evaporator. Switching between the cooling operation in which the refrigerant is circulated in the refrigerant circuit and the heating operation in which the refrigerant is circulated in the refrigerant circuit so that the heat source side heat exchanger becomes an evaporator and the use side heat exchanger becomes a condenser. Can be considered. Further, as in Patent Document 1, it is conceivable that the heat source side heat exchanger is configured by a shell-and-tube heat exchanger. That is, it is conceivable to configure the heat source side heat exchanger so that the refrigerant flows in the vertical direction in the heat source side heat exchanger.

  When configured as described above, in the cooling operation, the refrigerant discharged from the compressor flows from the top to the bottom of the heat source side heat exchanger, and in the heating operation, the refrigerant flowing out of the expansion mechanism The inside of the heat source side heat exchanger flows from below to above. In the heating operation, when the refrigerating machine oil is separated from the refrigerant (evaporated refrigerant) flowing from the lower side to the upper side in the heat source side heat exchanger, the refrigerating machine oil flows from the upper side to the lower side due to gravity, and the heat source It will accumulate in the inside of a side heat exchanger.

  In order to eliminate the accumulation of refrigerating machine oil in the heat source side heat exchanger as described above, an oil return pipe is provided in the heat source side heat exchanger, and the refrigerating machine oil accumulated in the heat source side heat exchanger is removed from the oil return pipe. It is possible to let it flow out of. However, the position where the refrigerating machine oil accumulates (the liquid level of the refrigerating machine oil) changes depending on factors such as the type of refrigerant, the type of refrigerating machine oil, and operating conditions (temperature and pressure). It is difficult to properly determine

  Then, this invention aims at providing the air conditioner which can suppress the accumulation of the refrigeration oil in the heat source side heat exchanger.

  The first invention includes a refrigerant circuit (20) having a compressor (21), a heat source side heat exchanger (23), an expansion mechanism (24), and a use side heat exchanger (25), and the refrigerant circuit ( 20) in the cooling operation in which the refrigerant circulates so that the heat source side heat exchanger (23) becomes a condenser and the use side heat exchanger (25) becomes an evaporator, and in the refrigerant circuit (20), An air conditioner that switches between a heating operation in which refrigerant circulates so that the heat exchanger (23) becomes an evaporator and the use side heat exchanger (25) becomes a condenser, and the heat source side heat exchanger (23) includes a first refrigerant connection pipe (23a) and a second refrigerant connection pipe (23b), and the refrigerant flowing from the first refrigerant connection pipe (23a) is converted into the heat source side heat exchanger (23). The refrigerant circuit (20) is configured to flow from the upper side to the lower side and flow out of the second refrigerant connection pipe (23b), and the refrigerant circuit (20) includes the heat source side heat exchanger ( 23) including a heat source side circuit section (30), and the heat source side circuit section (30) has a flow direction of the refrigerant passing through the heat source side heat exchanger (23) in both cooling operation and heating operation. An air conditioner configured to be directed from the first refrigerant connection pipe (23a) toward the second refrigerant connection pipe (23b).

  In the first aspect, in both the cooling operation and the heating operation, the flow direction of the refrigerant in the heat source side heat exchanger (23) can be changed from the upper side to the lower side. Therefore, even if the refrigeration oil is separated from the refrigerant flowing from the top to the bottom in the heat source side heat exchanger (23) in the heating operation, the refrigeration oil also flows from the top to the bottom due to gravity. Machine oil can flow out of the heat source side heat exchanger (23) together with the refrigerant.

  In a second aspect based on the first aspect, in the heating operation, the decompression amount of the refrigerant in the expansion mechanism (24) is adjusted according to the degree of superheat of the refrigerant flowing out from the heat source side heat exchanger (23). It is an air conditioner characterized by being made.

  In the second aspect of the invention, the amount of reduced pressure of the refrigerant in the expansion mechanism (24) is adjusted according to the degree of superheat of the refrigerant that has flowed out of the heat source side heat exchanger (23) in the heating operation, whereby the heat source during the heating operation is adjusted. The refrigerant can be reliably evaporated in the side heat exchanger (23).

  A third invention is the air conditioner according to the first or second invention, wherein the heat source side heat exchanger (23) is constituted by a shell-and-tube heat exchanger. .

  In the said 3rd invention, a heat source side heat exchanger (23) can be decomposed | disassembled easily by comprising a heat source side heat exchanger (23) with a shell and tube type heat exchanger.

  According to a fourth aspect of the present invention, in any one of the first to third aspects, the first refrigerant connection pipe (23a) of the heat source side heat exchanger (23) includes a condensation side refrigerant connection pipe (81). The heat source side heat exchanger (23) flows from the condensation side refrigerant connection pipe (81) or the plurality of evaporation side refrigerant connection pipes (82). The refrigerant flows in the heat source side heat exchanger (23) from the upper side to the lower side and flows out from the second refrigerant connection pipe (23b). The heat source side circuit part (30) And the refrigerant discharged from the compressor (21) in the cooling operation is supplied to the condensation side refrigerant connection pipe (81) of the heat source side heat exchanger (23), In the heating operation, the refrigerant that has flowed out of the expansion mechanism (24) passes through the flow divider (80) and the heat source side heat exchanger. An air conditioner configured to be supplied to a plurality of evaporation side refrigerant connection pipes (82) of (23).

  In the fourth aspect of the invention, the refrigerant flowing out of the expansion mechanism (24) in the heating operation passes through the flow divider (80) and is supplied to the plurality of evaporation side refrigerant connection pipes (82) of the heat source side heat exchanger (23). Thus, the evaporation of the refrigerant in the heat source side heat exchanger (23) can be promoted.

  According to 1st invention, even if refrigerating machine oil isolate | separates from the refrigerant | coolant which flows through the inside of a heat source side heat exchanger (23) toward the downward direction from the upper direction in heating operation, the refrigerating machine oil is combined with a refrigerant | coolant at the heat source side heat exchanger. Since it can be made to flow out from (23), accumulation of the refrigeration oil in the heat source side heat exchanger (23) can be suppressed.

  According to the second invention, since the refrigerant can be reliably evaporated in the heat source side heat exchanger (23) during the heating operation, the liquid refrigerant flows out of the heat source side heat exchanger (23) in the heating operation. Occurrence of a phenomenon (so-called liquid back phenomenon) that is sucked into the compressor (21) can be prevented.

  According to the third aspect, since the heat source side heat exchanger (23) can be easily disassembled, maintenance and inspection of the heat source side heat exchanger (23) can be facilitated.

  According to the fourth aspect of the invention, since the evaporation of the refrigerant in the heat source side heat exchanger (23) can be promoted in the heating operation, the liquid refrigerant flows out of the heat source side heat exchanger (23) and compresses in the heating operation. The phenomenon (so-called liquid back phenomenon) that is sucked into the machine (21) can be made difficult to occur.

FIG. 1 is a piping diagram illustrating a configuration example of an air conditioner according to an embodiment. FIG. 2 is a longitudinal sectional view showing a configuration example of the heat source side heat exchanger. FIG. 3 is a piping system diagram for explaining the cooling operation. FIG. 4 is a piping diagram for explaining the heating operation. FIG. 5 is a piping diagram showing a modification of the air conditioner.

  Hereinafter, embodiments will be described in detail with reference to the drawings. In the drawings, the same or corresponding parts are denoted by the same reference numerals, and description thereof will not be repeated.

(Air conditioner)
Drawing 1 shows an example of composition of an air harmony machine (10) by an embodiment. The air conditioner (10) performs air conditioning in an air-conditioning target space (for example, a ship cabin), and includes a refrigerant circuit (20) and a controller (60). In the air conditioner (10), a cooling operation for cooling the air-conditioning target space and a heating operation for heating the air-conditioning target space are performed.

<Refrigerant circuit>
The refrigerant circuit (20) includes a compressor (21), a four-way switching valve (22), a heat source side heat exchanger (23), an expansion mechanism (24), and a use side heat exchanger (25). It is configured to circulate and perform a vapor compression refrigeration cycle. Specifically, in the cooling operation, the refrigerant circulates in the refrigerant circuit (20) so that the heat source side heat exchanger (23) becomes a condenser and the use side heat exchanger (25) becomes a condenser. On the other hand, in the heating operation, the refrigerant circulates in the refrigerant circuit (20) so that the use side heat exchanger (25) serves as a condenser and the heat source side heat exchanger (23) serves as an evaporator. In this example, the refrigerant circuit (20) has a heat source side circuit section (30) including a heat source side heat exchanger (23). Also, in the vicinity of the use side heat exchanger (25), to supply use side air (air supplied to the cooling target space, for example, air in a ship's cabin) to the use side heat exchanger (25). The use side fan (26) is provided.

《Compressor》
The compressor (21) is configured to compress and discharge the sucked refrigerant. For example, the compressor (21) is constituted by a hermetic scroll compressor. Further, refrigeration oil for lubricating the compressor (21) is stored inside the compressor (21). A part of the refrigerating machine oil circulates in the refrigerant circuit (20) together with the refrigerant.

<4-way switching valve>
The four-way switching valve (22) includes a first state (state indicated by a solid line in FIG. 1) in which the first port and the third port communicate with each other and the second port and the fourth port communicate with each other; And the fourth port communicate with each other and the second state communicates between the second port and the third port (state indicated by a broken line in FIG. 1).

  In this example, the first port of the four-way selector valve (22) and the discharge port of the compressor (21) are connected to each other via the first refrigerant pipe (P1), and the second port of the four-way selector valve (22) The suction port of the compressor (21) is connected to each other via the second refrigerant pipe (P2). Further, the third port of the four-way switching valve (22) and one end (connection point (Q1)) of the heat source side circuit portion (30) are connected to each other via the third refrigerant pipe (P3), and the four-way switching valve (22 ) And the gas end of the use side heat exchanger (25) are connected to each other via a fourth refrigerant pipe (P4). Further, the other end (connection point (Q2)) of the heat source side circuit unit (30) and one end (connection point (Q3)) of the expansion mechanism (24) are connected to each other via the fifth refrigerant pipe (P5). The other end (connection point (Q4)) of the expansion mechanism (24) and the liquid end of the use side heat exchanger (25) are connected to each other via the sixth refrigerant pipe (P6).

《Heat source side heat exchanger》
The heat source side heat exchanger (23) is configured to exchange heat between the refrigerant and water (for example, seawater or fresh water). Specifically, the heat source side heat exchanger (23) has a first refrigerant connection pipe (23a) and a second refrigerant connection pipe (23b), and the refrigerant flowing from the first refrigerant connection pipe (23a) is the heat source. It is configured to flow from the upper side to the lower side of the side heat exchanger (23) (first flow path) and flow out from the second refrigerant connection pipe (23b).

  In this example, the heat source side heat exchanger (23) includes a first refrigerant connection pipe (23a), a second refrigerant connection pipe (23b), a first water connection pipe (23c), and a second water connection pipe (23d). have. Further, the heat source side heat exchanger (23) has a first flow for circulating the refrigerant flowing in from the first refrigerant connection pipe (23a) from above to flowing out from the second refrigerant connection pipe (23b). And a second flow path for allowing water flowing in from the first water connection pipe (23c) to flow and out of the second water connection pipe (23d). The heat source side heat exchanger (23) is configured to exchange heat between the refrigerant flowing through the first flow path and the water flowing through the second flow path.

  As shown in FIG. 2, the heat source side heat exchanger (23) is configured by a shell-and-tube heat exchanger. Specifically, the heat source side heat exchanger (23) includes a shell (71), a plurality of heat transfer tubes (72), and a support base (73).

  The shell (71) is formed in a cylindrical shape whose both ends are closed. The internal space of the shell (71) is partitioned into three spaces by first and second partition plates (71a, 71b) that are spaced apart in the axial direction of the shell (71), and the first partition plate (71a) The space between the first partition plate (71b) and the second partition plate (71b) forms a refrigerant chamber (S10), and the space between the first partition plate (71a) and one end of the shell (71) (the first partition in FIG. 2). The space on the right side of the plate (71a) constitutes the first header space (S11), and the space between the second partition plate (71b) and the other end of the shell (71) (the second partition plate in FIG. 2) (The space on the left side of (71b)) forms the second header space (S12). The first header space (S11) is divided into two spaces by a third partition plate (71c) extending in the axial direction of the shell (71), and one space (in FIG. 2, in front of the third partition plate (71c)). Side space) constitutes the first water chamber (S15), and the other space (in FIG. 2, the space behind the third partition plate (71c) in the drawing) constitutes the second water chamber (S16). .

  The 1st refrigerant | coolant connection pipe | tube (23a) is provided in the upper part of the shell (71), and is connected with the refrigerant | coolant chamber (S10). The second refrigerant connection pipe (23b) is provided at the lower part of the shell (71) and communicates with the refrigerant chamber (S10). The first and second water connection pipes (23c, 23d) are provided at one end (the right end in FIG. 2) of the shell (71) and communicate with the first and second water chambers (S15, S16), respectively. Yes.

  The plurality of heat transfer tubes (72) are provided in the refrigerant chamber (S10) and extend in the axial direction of the shell (71), respectively, and one end thereof penetrates the first partition plate (71a) to form the first header space ( S11) communicates with the other end of the second partition plate (71b) and communicates with the second header space (S12). The support base (73) supports the shell (71) so that the axial direction of the shell (71) faces the horizontal direction.

  In the heat source side heat exchanger (23) shown in FIG. 2, the refrigerant flowing into the refrigerant chamber (S10) from the first refrigerant connection pipe (23a) flows from the upper side to the lower side in the refrigerant chamber (S10). It flows out of the chamber (S10) to the second refrigerant connection pipe (23b). On the other hand, the water flowing into the first water chamber (S15) from the first water connection pipe (23c) is a part of the plurality of heat transfer pipes (72) (in FIG. 2, on the front side of the paper from the third partition plate (71c)). 2 flows to the second header space (S12), reverses the flow direction in the second header space (S12), and the remaining portions of the plurality of heat transfer tubes (72) (in FIG. 2) It flows through the heat transfer pipe (72) located on the back side of the paper with respect to the third partition plate (71c) and reaches the second water chamber (S16), and then the second water connection pipe from the second water chamber (S16). (23d) In the heat source side heat exchanger (23) shown in FIG. 2, the refrigerant flowing in the vertical direction in the refrigerant chamber (S10) and the water flowing in the plurality of heat transfer tubes (72) exchange heat.

<Expansion mechanism>
Returning to FIG. 1, the expansion mechanism (24) is configured to depressurize the refrigerant. The expansion mechanism (24) is configured to be able to adjust the amount of decompression of the refrigerant. In the cooling operation, the decompression amount of the refrigerant in the expansion mechanism (24) is adjusted according to the degree of superheat of the refrigerant flowing out from the use side heat exchanger (25). In the heating operation, the refrigerant flows out from the heat source side heat exchanger (23). The decompression amount of the refrigerant in the expansion mechanism (24) is adjusted according to the degree of superheat of the refrigerant.

  In this example, the expansion mechanism (24) has a first expansion valve (41) and a second expansion valve (42), and from the heat source side heat exchanger (23) to the first expansion valve (41) in the cooling operation. The refrigerant flows toward the use side heat exchanger (25) via the heat source, and in the heating operation, the heat source side heat exchanger (23) passes through the second expansion valve (42) and the use side heat exchanger (25). It is comprised so that a refrigerant | coolant may flow toward.

  The first and second expansion valves (41, 42) are constituted by temperature-sensitive expansion valves (temperature automatic expansion valves). Specifically, the first and second expansion valves (41, 42) have first and second temperature sensing tubes (41a, 42a), respectively. The first and second temperature sensing tubes (41a, 42a) are filled with the same refrigerant as the refrigerant circulating in the refrigerant circuit (20). The first temperature sensing cylinder (41a) is attached to a pipe (in this example, the second refrigerant pipe (P2)) through which the refrigerant flowing out from the use side heat exchanger (25) flows in the cooling operation, and the second temperature sensing cylinder ( 42a) is attached to a pipe (in this example, the second refrigerant connection pipe (23b) of the heat source side heat exchanger (23)) through which the refrigerant flowing out from the heat source side heat exchanger (23) flows in the heating operation. The first and second expansion valves (41, 42) are configured such that their opening degrees are automatically adjusted according to the temperatures of the first and second temperature sensing tubes (41a, 42a), respectively. .

  The first and second expansion valves (41, 42) may be constituted by external pressure equalization type temperature automatic expansion valves. Specifically, the first and second expansion valves (41, 42) may have first and second temperature sensing tubes (41a, 42a) and first and second pressure equalizing tubes, respectively. The pressure equalizing pipe (first pressure equalizing pipe) of the first expansion valve (41) is connected to a pipe (in this example, the second refrigerant pipe (P2)) through which the refrigerant flowing out from the use side heat exchanger (25) flows in the cooling operation. The pressure equalizing pipe (second pressure equalizing pipe) of the second expansion valve (42) is a pipe (in this example, the heat source side heat exchanger (23) through which the refrigerant flowing out from the heat source side heat exchanger (23) flows in the heating operation. Of the second refrigerant connection pipe (23b). The first expansion valve (41) is configured such that the opening degree is automatically adjusted according to the temperature of the first temperature sensing cylinder (41a) and the refrigerant pressure in the first pressure equalizing pipe, and the second expansion valve (41). The valve (42) is configured such that the opening degree is automatically adjusted according to the temperature of the second temperature sensing cylinder (42a) and the refrigerant pressure in the second pressure equalizing pipe.

  In this example, the expansion mechanism (24) includes, in addition to the first and second expansion valves (41, 42), the intermediate pipe (50), the first and second main pipes (51, 52), and the first And a second bypass pipe (53, 54), first and second filters (55, 56), and first and second bypass check valves (57, 58).

  The first main pipe (51) is a pipe for flowing a refrigerant between the heat source side circuit unit (30) and the use side heat exchanger (25) via the first expansion valve (41). The first main pipe (51) is provided with a first expansion valve (41). The first main pipe (51) has one end connected to one end of the intermediate pipe (50) and the other end connected to the liquid end of the use side heat exchanger (25) via the sixth refrigerant pipe (P6). It is connected.

  The 2nd main piping (52) is piping for flowing a refrigerant between the heat source side circuit part (30) and the use side heat exchanger (25) via the 2nd expansion valve (42). The second main pipe (52) is provided with a second expansion valve (42). In this example, the second main pipe (52) has one end connected to one end of the intermediate pipe (50) and the other end connected to the other end of the heat source side circuit section (30) via the fifth refrigerant pipe (P5). (Connecting point (Q2)).

  The first bypass pipe (53) is a pipe for allowing the refrigerant to flow between the heat source side circuit unit (30) and the use side heat exchanger (25), bypassing the first expansion valve (41). In this example, the first bypass pipe (53) has one end connected to the other end of the intermediate pipe (50) and the other end connected to the use side heat exchanger (25) via the sixth refrigerant pipe (P6). Connected to the liquid end. The first bypass pipe (53) is provided with a first filter (55) and a first bypass check valve (57). The first bypass check valve (57) is a refrigerant flow from the use side heat exchanger (25) side to the heat source side circuit section (30) side (in this example, from the sixth refrigerant pipe (P6) to the intermediate pipe ( 50), only the refrigerant flow toward the other end is allowed.

  The second bypass pipe (54) is a pipe for bypassing the second expansion valve (42) and causing the refrigerant to flow between the heat source side circuit unit (30) and the use side heat exchanger (25). In this example, the second bypass pipe (54) has one end connected to the other end of the intermediate pipe (50) and the other end connected to the heat source side circuit section (30) via the fifth refrigerant pipe (P5). Connected to the other end (connection point (Q2)). The second bypass pipe (54) is provided with a second filter (56) and a second bypass check valve (58). The second bypass check valve (58) is a refrigerant flow from the heat source side circuit section (30) side to the use side heat exchanger (25) side (in this example, from the fifth refrigerant pipe (P5) to the intermediate pipe ( 50), only the refrigerant flow toward the other end is allowed.

《Use side heat exchanger》
The use side heat exchanger (25) is configured to exchange heat between the refrigerant and the use side air (air supplied to the cooling target space) conveyed by the use side fan (26). In this example, the use side heat exchanger (25) is a fin-and-tube heat exchanger.

<Heat source side circuit section>
In the heat source side circuit unit (30), the flow direction of the refrigerant passing through the heat source side heat exchanger (23) in both the cooling operation and the heating operation is changed from the first refrigerant connection tube (23a) to the second refrigerant connection tube (23b). It is comprised so that it may become the direction which goes to. In this example, the heat source side circuit unit (30) includes first to fourth connection pipes (31 to 34) and first to fourth check valves (35 to 38).

  One end of the first connection pipe (31) is connected to the first refrigerant connection pipe (23a) of the heat source side heat exchanger (23), and the other end is connected to the four-way switching valve (P3) via the third refrigerant pipe (P3). 22) connected to the third port. The first check valve (35) is provided in the first connection pipe (31) and is connected to the heat source side heat exchanger (23) from the third refrigerant pipe (P3) side (that is, the four-way switching valve (22) side). Only the flow of the refrigerant toward the first refrigerant connection pipe (23a) side is allowed.

  One end of the second connection pipe (32) is connected to the first refrigerant connection pipe (23a) of the heat source side heat exchanger (23), and the other end is connected to the expansion mechanism (24 via the fifth refrigerant pipe (P5)). ) Is connected to one end (connection point (Q3)). The second check valve (36) is provided in the second connection pipe (32) and is connected to the heat source side heat exchanger (23) from the fifth refrigerant pipe (P5) side (that is, the expansion mechanism (24) side). It is configured to allow only the refrigerant flow toward the one refrigerant connection pipe (23a) side.

  One end of the third connection wiring (33) is connected to the second refrigerant connection pipe (23b) of the heat source side heat exchanger (23), and the other end is connected to the expansion mechanism (24 via the fifth refrigerant pipe (P5)). ) Is connected to one end (connection point (Q3)). The third check valve (37) is provided on the third connection wiring (33) and extends from the second refrigerant connection pipe (23b) side of the heat source side heat exchanger (23) to the fifth refrigerant pipe (P5) side (that is, , Only the refrigerant flow toward the expansion mechanism (24 side) is allowed.

  One end of the fourth connection wiring (34) is connected to the second refrigerant connection pipe (23b) of the heat source side heat exchanger (23), and the other end is connected to the four-way switching valve (P3) via the third refrigerant pipe (P3). 22) connected to the third port. The fourth check valve (38) is provided on the fourth connection wiring (34) and extends from the second refrigerant connection pipe (23b) side of the heat source side heat exchanger (23) to the third refrigerant pipe (P3) side (that is, The refrigerant flow only toward the four-way switching valve (22 side) is allowed.

<controller>
The controller (60) controls each part of the air conditioner (10) based on detection values of various sensors (such as a temperature sensor and a pressure sensor) provided in the air conditioner (10) to control the air conditioner (10). It is comprised so that the driving | operation operation | movement may be controlled. Specifically, the controller (60) is configured to control the compressor (21), the four-way switching valve (22), and the use side fan (26).

<Cooling operation>
Next, the cooling operation will be described with reference to FIG. In the cooling operation, the four-way switching valve (22) is set to the first state. Thereby, the discharge port of the compressor (21) and the heat source side circuit part (30) communicate with each other, and the suction port of the compressor (21) communicates with the gas end of the use side heat exchanger (25). Further, the compressor (21) and the use-side fan (26) are set to the driving state. Thus, the refrigerant circulates in the refrigerant circuit (20) so that a refrigeration cycle in which the heat source side heat exchanger (23) serves as a condenser and the use side heat exchanger (25) serves as an evaporator is performed.

  Further, the amount of decompression of the refrigerant in the expansion mechanism (24) is adjusted according to the degree of superheat of the refrigerant flowing out from the gas end of the use side heat exchanger (25). In this example, according to the temperature of the first temperature sensing cylinder (41a), the superheat degree of the refrigerant flowing out from the gas end of the use side heat exchanger (25) becomes a predetermined target superheat degree. The opening degree of the one expansion valve (41) is automatically adjusted.

  The refrigerant discharged from the compressor (21) passes through the four-way switching valve (22) and flows into the heat source side circuit section (30). The refrigerant flowing into the heat source side circuit section (30) passes through the first check valve (35) and flows into the first refrigerant connection pipe (23a) of the heat source side heat exchanger (23). In the heat source side heat exchanger (23), the refrigerant flowing in from the first refrigerant connection pipe (23a) passes through the interior of the heat source side heat exchanger (23) (specifically, the refrigerant chamber (S10)) in the vertical direction. While flowing downward from the heat source side heat exchanger (23) (specifically, the heat transfer pipe (72)) dissipates heat and condenses, and then the second refrigerant connection pipe (23b) Spill from. The refrigerant that has flowed out of the second refrigerant connection pipe (23b) of the heat source side heat exchanger (23) passes through the third check valve (37) and flows into the expansion mechanism (24). The refrigerant that has flowed into the expansion mechanism (24) sequentially passes through the second filter (56), the second bypass check valve (58), and the intermediate pipe (50), and flows into the first expansion valve (41). The pressure is reduced at the first expansion valve (41). The refrigerant decompressed in the first expansion valve (41) flows into the use side heat exchanger (25) and evaporates by absorbing heat from the use side air in the use side heat exchanger (25). Thereby, utilization side air is cooled and the air-conditioning object space is cooled. The refrigerant flowing out from the use side heat exchanger (25) passes through the four-way switching valve (22) and is sucked into the compressor (21).

<Heating operation>
Next, the heating operation will be described with reference to FIG. In the heating operation, the four-way selector valve (22) is set to the second state. Thereby, the discharge port of the compressor (21) communicates with the gas end of the use side heat exchanger (25), and the suction port of the compressor (21) communicates with the heat source side circuit unit (30). Further, the compressor (21) and the use-side fan (26) are set to the driving state. Thus, the refrigerant circulates in the refrigerant circuit (20) so that a refrigeration cycle is performed in which the use side heat exchanger (25) serves as a condenser and the heat source side heat exchanger (23) serves as an evaporator.

  Moreover, the pressure reduction amount of the refrigerant in the expansion mechanism (24) is adjusted according to the degree of superheat of the refrigerant flowing out from the second refrigerant connection pipe (23b) of the heat source side heat exchanger (23). In this example, the second temperature sensing cylinder (42a) is set so that the superheat degree of the refrigerant flowing out from the second refrigerant connection pipe (23b) of the heat source side heat exchanger (23) becomes a predetermined target superheat degree. The opening degree of the second expansion valve (42) is automatically adjusted in accordance with the temperature.

  The refrigerant discharged from the compressor (21) passes through the four-way switching valve (22), flows into the use side heat exchanger (25), and dissipates heat to the use side air in the use side heat exchanger (25). Condensate. Thereby, utilization side air is heated and the air-conditioning object space is heated. The refrigerant that has flowed out of the use side heat exchanger (25) flows into the expansion mechanism (24). The refrigerant that has flowed into the expansion mechanism (24) sequentially passes through the first filter (55), the first bypass check valve (57), and the intermediate pipe (50), and flows into the second expansion valve (42). The pressure is reduced at the second expansion valve (42). The refrigerant that has flowed out of the second expansion valve (42) flows into the heat source side circuit section (30). The refrigerant flowing into the heat source side circuit section (30) passes through the second check valve (36) and flows into the first refrigerant connection pipe (23a) of the heat source side heat exchanger (23). In the heat source side heat exchanger (23), the refrigerant flowing in from the first refrigerant connection pipe (23a) passes through the interior of the heat source side heat exchanger (23) (specifically, the refrigerant chamber (S10)) in the vertical direction. While flowing downward from the heat source, it absorbs heat from the water flowing through the inside of the heat source side heat exchanger (23) (specifically, the heat transfer pipe (72)) and evaporates, and then the second refrigerant connection pipe (23b) Spill from. The refrigerant that has flowed out of the second refrigerant connection pipe (23b) of the heat source side heat exchanger (23) passes through the fourth check valve (38) and the four-way switching valve (22) in this order to the compressor (21). Inhaled.

<Effects of the embodiment>
As described above, in both the cooling operation and the heating operation, the flow direction of the refrigerant in the heat source side heat exchanger (23) can be changed from the upper side to the lower side. Therefore, even if the refrigeration oil is separated from the refrigerant flowing from the top to the bottom in the heat source side heat exchanger (23) in the heating operation, the refrigeration oil also flows from the top to the bottom due to gravity. Machine oil can flow out of the heat source side heat exchanger (23) together with the refrigerant. Thereby, accumulation of the refrigerating machine oil in the heat source side heat exchanger (23) can be suppressed.

  Further, the amount of decompression of the refrigerant in the expansion mechanism (24) is adjusted according to the degree of superheat of the refrigerant that has flowed out of the heat source side heat exchanger (23) in the heating operation, so that the heat source side heat exchanger ( In 23), the refrigerant can be reliably evaporated. Thereby, it is possible to prevent the occurrence of a phenomenon (so-called liquid back phenomenon) in which liquid refrigerant flows out of the heat source side heat exchanger (23) and is sucked into the compressor (21) in the heating operation.

  Further, the decompression amount of the refrigerant in the expansion mechanism (24) is adjusted in accordance with the degree of superheat of the refrigerant that has flowed out of the use side heat exchanger (25) in the cooling operation, so that the use side heat exchanger ( In 25), the refrigerant can be reliably evaporated. Thereby, it is possible to prevent the occurrence of a phenomenon (so-called liquid back phenomenon) in which the liquid refrigerant flows out from the use side heat exchanger (25) and is sucked into the compressor (21) in the cooling operation.

  Moreover, the heat source side heat exchanger (23) can be easily disassembled by configuring the heat source side heat exchanger (23) with a shell-and-tube heat exchanger. Thereby, maintenance and inspection of the heat source side heat exchanger (23) can be facilitated.

(Modification of air conditioner)
Next, a modification of the air conditioner (10) will be described with reference to FIG. The air conditioner (10) shown in FIG. 5 is different from the air conditioner (10) shown in FIG. 1 in the configuration of the heat source side heat exchanger (23) and the heat source side circuit unit (30). In addition, the other structure of the air conditioner (10) shown in FIG. 5 is the same as that of the air conditioner (10) shown in FIG.

《Heat source side heat exchanger》
In the example of FIG. 5, the first refrigerant connection pipe (23a) of the heat source side heat exchanger (23) includes a condensation side refrigerant connection pipe (81) and a plurality (six in this example) of evaporation side refrigerant connection pipes ( 82). The heat source side heat exchanger (23) is configured such that the refrigerant flowing from the condensation side refrigerant connection pipe (81) or the plurality of evaporation side refrigerant connection pipes (82) passes through the inside of the heat source side heat exchanger (23) from above. And flows out from the second refrigerant connecting pipe (23b).

  Specifically, in the example of FIG. 5, the heat source side heat exchanger (23) is configured by a shell-and-tube heat exchanger (see FIG. 2). For example, the condensation side refrigerant connection pipe (81) and the plurality of evaporation side refrigerant connection pipes (82) are provided on the upper part of the shell (71) shown in FIG. 2 and communicate with the refrigerant chamber (S10). The other configuration of the heat source side heat exchanger (23) may be the same as the configuration of the heat source side heat exchanger (23) shown in FIG. In the heat source side heat exchanger (23) configured as described above, heat is exchanged between the refrigerant flowing in the vertical direction in the refrigerant chamber (S10) and the refrigerant flowing in the plurality of heat transfer tubes (72).

<Heat source side circuit section>
In the example of FIG. 5, the heat source side circuit unit (30) includes a flow divider (80) for diverting the refrigerant. The flow divider (80) has one inflow port and a plurality of (in this example, six) outflow ports, and is configured to divert refrigerant flowing in from the inflow port and outflow from the plurality of outflow ports. Yes. In the heat source side circuit unit (30), the refrigerant discharged from the compressor (21) in the cooling operation is supplied to the condensing side refrigerant connection pipe (81) of the heat source side heat exchanger (23), and is expanded in the heating operation. The refrigerant that has flowed out of the mechanism (24) passes through the flow divider (80) and is supplied to the plurality of evaporation side refrigerant connection pipes (82) of the heat source side heat exchanger (23).

  Specifically, in the example of FIG. 5, one end of the first connection pipe (31) of the heat source side circuit section (30) is connected to the condensation side refrigerant connection pipe (81) of the heat source side heat exchanger (23). The other end is connected to the third port of the four-way switching valve (22) via the third refrigerant pipe (P3). One end of the second connection pipe (32) of the heat source side circuit section (30) is connected to the plurality of evaporation side refrigerant connection pipes (82) via the flow divider (80), and the other end is connected to the fifth refrigerant pipe ( It is connected to one end (connection point (Q3)) of the expansion mechanism (24) via P5). That is, one end of the second connection pipe (32) is connected to one inlet of the flow divider (80), and a plurality of outlets of the flow divider (80) are connected to a plurality of evaporation side refrigerant connection pipes (82), respectively. Has been. The second check valve (36) is provided between the flow divider (80) and the fifth refrigerant pipe (P5) in the second connection pipe (32). The other configuration of the heat source side circuit unit (30) is the same as the configuration of the heat source side circuit unit (30) shown in FIG.

<Effects of Modification of Embodiment>
As described above, the refrigerant flowing out from the expansion mechanism (24) in the heating operation passes through the flow divider (80) and is supplied to the plurality of evaporation side refrigerant connection pipes (82) of the heat source side heat exchanger (23). As a result, the evaporation of the refrigerant in the heat source side heat exchanger (23) can be promoted. Thereby, it is possible to make it difficult to generate a phenomenon (so-called liquid back phenomenon) in which the liquid refrigerant flows out of the heat source side heat exchanger (23) and is sucked into the compressor (21) in the heating operation.

(Other embodiments)
In the above description, the case where the heat source side heat exchanger (23) is configured by a shell and tube type heat exchanger is taken as an example, but the heat source side heat exchanger (23) is a shell and tube type heat exchanger. For example, it may be configured by a plate-type heat exchanger. Also in this case, the refrigerant flowing in from the first refrigerant connection pipe (23a) flows from the upper side to the lower side of the heat source side heat exchanger (23) (first flow path) and flows downward from the second refrigerant connection pipe (23b). The water flowing out from the first water connection pipe (23c) passes through the inside of the heat source side heat exchanger (23) (second flow path different from the first flow path) and passes through the second water connection pipe ( 23d), the refrigerant flowing vertically in the heat source side heat exchanger (23) (first flow path) and the water flowing in the heat source side heat exchanger (23) (second flow path) The heat source side heat exchanger (23) can be configured to exchange heat.

  In the above description, the case where the expansion mechanism (24) is constituted by the first and second expansion valves (41, 42) that are temperature-sensitive expansion valves (temperature automatic expansion valves) is taken as an example. The expansion mechanism (24) may be configured by an electronic expansion valve (motor-operated valve) whose opening degree is adjusted by the control of the controller (60). As described above, when the expansion mechanism (24) is configured by the electronic expansion valve, in the cooling operation, the electronic expansion that configures the expansion mechanism (24) according to the degree of superheat of the refrigerant that has flowed out of the use side heat exchanger (25). The opening degree of the valve is adjusted, and in the heating operation, the opening degree of the electronic expansion valve constituting the expansion mechanism (24) is adjusted according to the degree of superheat of the refrigerant flowing out from the heat source side heat exchanger (23).

  Moreover, you may implement combining the above embodiment and modification suitably. The above embodiments and modifications are essentially preferable examples, and are not intended to limit the scope of the present invention, its application, or its use.

  As described above, the above-described air conditioner is useful as an air conditioner that performs air conditioning in the air-conditioning target space.

DESCRIPTION OF SYMBOLS 10 Air conditioner 20 Refrigerant circuit 21 Compressor 22 Four-way switching valve 23 Heat source side heat exchanger 23a First refrigerant connection pipe 23b Second refrigerant connection pipe 23c First water connection pipe 23d Second water connection pipe 24 Expansion mechanism 25 Use side Heat exchanger 26 Use side fan 30 Heat source side circuit unit 41 First expansion valve 42 Second expansion valve 60 Controller 71 Shell 72 Heat transfer pipe 73 Support base 80 Divider 81 Condensation side refrigerant connection pipe 82 Evaporation side refrigerant connection pipe S10 Refrigerant chamber S11 1st header space S12 2nd header space S15 1st water chamber S16 2nd water chamber

  The present invention relates to an air conditioner.

  Conventionally, an air conditioner including a refrigerant circuit that performs a refrigeration cycle is known. For example, Patent Literature 1 includes an air conditioner that performs a cooling operation that includes a refrigerant circuit having a compressor, a condenser (heat source side heat exchanger), an expansion mechanism, and an evaporator (use side heat exchanger) to cool the cabin. An apparatus is disclosed. Moreover, in the air conditioner of patent document 1, the condenser is comprised with the shell and tube type heat exchanger. Specifically, the condenser includes a shell formed in a cylindrical shape and a plurality of heat transfer tubes provided inside the shell. A refrigerant inlet pipe is provided at the upper part of the shell, and a refrigerant outlet pipe is provided at the lower part of the shell. The refrigerant that has flowed into the shell from the refrigerant inlet pipe flows from the upper side to the lower side of the shell and flows out from the refrigerant outlet pipe. The refrigerant flowing from the top to the bottom in the shell is cooled by exchanging heat with the cooling water flowing through the plurality of heat transfer tubes.

JP 2012-136152 A

  Incidentally, in an air conditioner having a refrigerant circuit having a compressor, a heat source side heat exchanger, an expansion mechanism, and a use side heat exchanger, the heat source side heat exchanger becomes a condenser and the use side heat exchanger becomes an evaporator. Switching between the cooling operation in which the refrigerant is circulated in the refrigerant circuit and the heating operation in which the refrigerant is circulated in the refrigerant circuit so that the heat source side heat exchanger becomes an evaporator and the use side heat exchanger becomes a condenser. Can be considered. Further, as in Patent Document 1, it is conceivable that the heat source side heat exchanger is configured by a shell-and-tube heat exchanger. That is, it is conceivable to configure the heat source side heat exchanger so that the refrigerant flows in the vertical direction in the heat source side heat exchanger.

  When configured as described above, in the cooling operation, the refrigerant discharged from the compressor flows from the top to the bottom of the heat source side heat exchanger, and in the heating operation, the refrigerant flowing out of the expansion mechanism The inside of the heat source side heat exchanger flows from below to above. In the heating operation, when the refrigerating machine oil is separated from the refrigerant (evaporated refrigerant) flowing from the lower side to the upper side in the heat source side heat exchanger, the refrigerating machine oil flows from the upper side to the lower side due to gravity, and the heat source It will accumulate in the inside of a side heat exchanger.

  In order to eliminate the accumulation of refrigerating machine oil in the heat source side heat exchanger as described above, an oil return pipe is provided in the heat source side heat exchanger, and the refrigerating machine oil accumulated in the heat source side heat exchanger is removed from the oil return pipe. It is possible to let it flow out of. However, the position where the refrigerating machine oil accumulates (the liquid level of the refrigerating machine oil) changes depending on factors such as the type of refrigerant, the type of refrigerating machine oil, and operating conditions (temperature and pressure). It is difficult to properly determine

  Then, this invention aims at providing the air conditioner which can suppress the accumulation of the refrigeration oil in the heat source side heat exchanger.

The first invention includes a refrigerant circuit (20) having a compressor (21), a heat source side heat exchanger (23), an expansion mechanism (24), and a use side heat exchanger (25), and the refrigerant circuit ( 20) in the cooling operation in which the refrigerant circulates so that the heat source side heat exchanger (23) becomes a condenser and the use side heat exchanger (25) becomes an evaporator, and in the refrigerant circuit (20), An air conditioner that switches between a heating operation in which refrigerant circulates so that the heat exchanger (23) becomes an evaporator and the use side heat exchanger (25) becomes a condenser, and the heat source side heat exchanger (23) includes a first refrigerant connection pipe (23a) and a second refrigerant connection pipe (23b), and the refrigerant flowing from the first refrigerant connection pipe (23a) is converted into the heat source side heat exchanger (23). The refrigerant circuit (20) is configured to flow from the upper side to the lower side and flow out of the second refrigerant connection pipe (23b), and the refrigerant circuit (20) includes the heat source side heat exchanger ( 23) including a heat source side circuit section (30), and the heat source side circuit section (30) has a flow direction of the refrigerant passing through the heat source side heat exchanger (23) in both cooling operation and heating operation. The first refrigerant connection pipe (23a) of the heat source side heat exchanger (23) is configured to be in a direction from the first refrigerant connection pipe (23a) to the second refrigerant connection pipe (23b). Side refrigerant connection pipe (81) and a plurality of evaporation side refrigerant connection pipes (82), and the heat source side heat exchanger (23) includes the condensation side refrigerant connection pipe (81) or the plurality of evaporation sides. The refrigerant flowing in from the refrigerant connection pipe (82) flows from the upper side to the lower side in the heat source side heat exchanger (23) and flows out from the second refrigerant connection pipe (23b). The side circuit part (30) has a flow divider (80) for diverting the refrigerant, and in the cooling operation, the compressor (21) The refrigerant discharged from the heat source side heat exchanger (23) is supplied to the condensation side refrigerant connection pipe (81), and the refrigerant flowing out of the expansion mechanism (24) in the heating operation passes through the flow divider (80). An air conditioner configured to pass through and be supplied to a plurality of evaporation side refrigerant connection pipes (82) of the heat source side heat exchanger (23) .

  In the first aspect, in both the cooling operation and the heating operation, the flow direction of the refrigerant in the heat source side heat exchanger (23) can be changed from the upper side to the lower side. Therefore, even if the refrigeration oil is separated from the refrigerant flowing from the top to the bottom in the heat source side heat exchanger (23) in the heating operation, the refrigeration oil also flows from the top to the bottom due to gravity. Machine oil can flow out of the heat source side heat exchanger (23) together with the refrigerant.

  In the first invention, the refrigerant that has flowed out of the expansion mechanism (24) in the heating operation passes through the flow divider (80), and the plurality of evaporation-side refrigerant connection pipes (82) of the heat source side heat exchanger (23). , The evaporation of the refrigerant in the heat source side heat exchanger (23) can be promoted.

  In a second aspect based on the first aspect, in the heating operation, the decompression amount of the refrigerant in the expansion mechanism (24) is adjusted according to the degree of superheat of the refrigerant flowing out from the heat source side heat exchanger (23). It is an air conditioner characterized by being made.

  In the second aspect of the invention, the amount of reduced pressure of the refrigerant in the expansion mechanism (24) is adjusted according to the degree of superheat of the refrigerant that has flowed out of the heat source side heat exchanger (23) in the heating operation, whereby the heat source during the heating operation is adjusted. The refrigerant can be reliably evaporated in the side heat exchanger (23).

  A third invention is the air conditioner according to the first or second invention, wherein the heat source side heat exchanger (23) is constituted by a shell-and-tube heat exchanger. .

In the said 3rd invention, a heat source side heat exchanger (23) can be decomposed | disassembled easily by comprising a heat source side heat exchanger (23) with a shell and tube type heat exchanger .

  According to 1st invention, even if refrigerating machine oil isolate | separates from the refrigerant | coolant which flows through the inside of a heat source side heat exchanger (23) toward the downward direction from the upper direction in heating operation, the refrigerating machine oil is combined with a refrigerant | coolant at the heat source side heat exchanger. Since it can be made to flow out from (23), accumulation of the refrigeration oil in the heat source side heat exchanger (23) can be suppressed.

  According to the second invention, since the refrigerant can be reliably evaporated in the heat source side heat exchanger (23) during the heating operation, the liquid refrigerant flows out of the heat source side heat exchanger (23) in the heating operation. Occurrence of a phenomenon (so-called liquid back phenomenon) that is sucked into the compressor (21) can be prevented.

  According to the third aspect, since the heat source side heat exchanger (23) can be easily disassembled, maintenance and inspection of the heat source side heat exchanger (23) can be facilitated.

Further , according to the first invention, since the evaporation of the refrigerant in the heat source side heat exchanger (23) can be promoted in the heating operation, the liquid refrigerant flows out from the heat source side heat exchanger (23) in the heating operation. Thus, it is possible to make it difficult to generate a phenomenon (so-called liquid back phenomenon) that is sucked into the compressor (21).

FIG. 1 is a piping diagram illustrating a configuration example of an air conditioner according to an embodiment. FIG. 2 is a longitudinal sectional view showing a configuration example of the heat source side heat exchanger. FIG. 3 is a piping system diagram for explaining the cooling operation. FIG. 4 is a piping diagram for explaining the heating operation. FIG. 5 is a piping diagram showing a modification of the air conditioner.

  Hereinafter, embodiments will be described in detail with reference to the drawings. In the drawings, the same or corresponding parts are denoted by the same reference numerals, and description thereof will not be repeated.

(Air conditioner)
Drawing 1 shows an example of composition of an air harmony machine (10) by an embodiment. The air conditioner (10) performs air conditioning in an air-conditioning target space (for example, a ship cabin), and includes a refrigerant circuit (20) and a controller (60). In the air conditioner (10), a cooling operation for cooling the air-conditioning target space and a heating operation for heating the air-conditioning target space are performed.

<Refrigerant circuit>
The refrigerant circuit (20) includes a compressor (21), a four-way switching valve (22), a heat source side heat exchanger (23), an expansion mechanism (24), and a use side heat exchanger (25). It is configured to circulate and perform a vapor compression refrigeration cycle. Specifically, in the cooling operation, the refrigerant circulates in the refrigerant circuit (20) so that the heat source side heat exchanger (23) becomes a condenser and the use side heat exchanger (25) becomes a condenser. On the other hand, in the heating operation, the refrigerant circulates in the refrigerant circuit (20) so that the use side heat exchanger (25) serves as a condenser and the heat source side heat exchanger (23) serves as an evaporator. In this example, the refrigerant circuit (20) has a heat source side circuit section (30) including a heat source side heat exchanger (23). Also, in the vicinity of the use side heat exchanger (25), to supply use side air (air supplied to the cooling target space, for example, air in a ship's cabin) to the use side heat exchanger (25). The use side fan (26) is provided.

《Compressor》
The compressor (21) is configured to compress and discharge the sucked refrigerant. For example, the compressor (21) is constituted by a hermetic scroll compressor. Further, refrigeration oil for lubricating the compressor (21) is stored inside the compressor (21). A part of the refrigerating machine oil circulates in the refrigerant circuit (20) together with the refrigerant.

<4-way switching valve>
The four-way switching valve (22) includes a first state (state indicated by a solid line in FIG. 1) in which the first port and the third port communicate with each other and the second port and the fourth port communicate with each other; And the fourth port communicate with each other and the second state communicates between the second port and the third port (state indicated by a broken line in FIG. 1).

  In this example, the first port of the four-way selector valve (22) and the discharge port of the compressor (21) are connected to each other via the first refrigerant pipe (P1), and the second port of the four-way selector valve (22) The suction port of the compressor (21) is connected to each other via the second refrigerant pipe (P2). Further, the third port of the four-way switching valve (22) and one end (connection point (Q1)) of the heat source side circuit portion (30) are connected to each other via the third refrigerant pipe (P3), and the four-way switching valve (22 ) And the gas end of the use side heat exchanger (25) are connected to each other via a fourth refrigerant pipe (P4). Further, the other end (connection point (Q2)) of the heat source side circuit unit (30) and one end (connection point (Q3)) of the expansion mechanism (24) are connected to each other via the fifth refrigerant pipe (P5). The other end (connection point (Q4)) of the expansion mechanism (24) and the liquid end of the use side heat exchanger (25) are connected to each other via the sixth refrigerant pipe (P6).

《Heat source side heat exchanger》
The heat source side heat exchanger (23) is configured to exchange heat between the refrigerant and water (for example, seawater or fresh water). Specifically, the heat source side heat exchanger (23) has a first refrigerant connection pipe (23a) and a second refrigerant connection pipe (23b), and the refrigerant flowing from the first refrigerant connection pipe (23a) is the heat source. It is configured to flow from the upper side to the lower side of the side heat exchanger (23) (first flow path) and flow out from the second refrigerant connection pipe (23b).

  In this example, the heat source side heat exchanger (23) includes a first refrigerant connection pipe (23a), a second refrigerant connection pipe (23b), a first water connection pipe (23c), and a second water connection pipe (23d). have. Further, the heat source side heat exchanger (23) has a first flow for circulating the refrigerant flowing in from the first refrigerant connection pipe (23a) from above to flowing out from the second refrigerant connection pipe (23b). And a second flow path for allowing water flowing in from the first water connection pipe (23c) to flow and out of the second water connection pipe (23d). The heat source side heat exchanger (23) is configured to exchange heat between the refrigerant flowing through the first flow path and the water flowing through the second flow path.

  As shown in FIG. 2, the heat source side heat exchanger (23) is configured by a shell-and-tube heat exchanger. Specifically, the heat source side heat exchanger (23) includes a shell (71), a plurality of heat transfer tubes (72), and a support base (73).

  The shell (71) is formed in a cylindrical shape whose both ends are closed. The internal space of the shell (71) is partitioned into three spaces by first and second partition plates (71a, 71b) that are spaced apart in the axial direction of the shell (71), and the first partition plate (71a) The space between the first partition plate (71b) and the second partition plate (71b) forms a refrigerant chamber (S10), and the space between the first partition plate (71a) and one end of the shell (71) (the first partition in FIG. 2). The space on the right side of the plate (71a) constitutes the first header space (S11), and the space between the second partition plate (71b) and the other end of the shell (71) (the second partition plate in FIG. 2) (The space on the left side of (71b)) forms the second header space (S12). The first header space (S11) is divided into two spaces by a third partition plate (71c) extending in the axial direction of the shell (71), and one space (in FIG. 2, in front of the third partition plate (71c)). Side space) constitutes the first water chamber (S15), and the other space (in FIG. 2, the space behind the third partition plate (71c) in the drawing) constitutes the second water chamber (S16). .

  The 1st refrigerant | coolant connection pipe | tube (23a) is provided in the upper part of the shell (71), and is connected with the refrigerant | coolant chamber (S10). The second refrigerant connection pipe (23b) is provided at the lower part of the shell (71) and communicates with the refrigerant chamber (S10). The first and second water connection pipes (23c, 23d) are provided at one end (the right end in FIG. 2) of the shell (71) and communicate with the first and second water chambers (S15, S16), respectively. Yes.

  The plurality of heat transfer tubes (72) are provided in the refrigerant chamber (S10) and extend in the axial direction of the shell (71), respectively, and one end thereof penetrates the first partition plate (71a) to form the first header space ( S11) communicates with the other end of the second partition plate (71b) and communicates with the second header space (S12). The support base (73) supports the shell (71) so that the axial direction of the shell (71) faces the horizontal direction.

  In the heat source side heat exchanger (23) shown in FIG. 2, the refrigerant flowing into the refrigerant chamber (S10) from the first refrigerant connection pipe (23a) flows from the upper side to the lower side in the refrigerant chamber (S10). It flows out of the chamber (S10) to the second refrigerant connection pipe (23b). On the other hand, the water flowing into the first water chamber (S15) from the first water connection pipe (23c) is a part of the plurality of heat transfer pipes (72) (in FIG. 2, on the front side of the paper from the third partition plate (71c)). 2 flows to the second header space (S12), reverses the flow direction in the second header space (S12), and the remaining portions of the plurality of heat transfer tubes (72) (in FIG. 2) It flows through the heat transfer pipe (72) located on the back side of the paper with respect to the third partition plate (71c) and reaches the second water chamber (S16), and then the second water connection pipe from the second water chamber (S16). (23d) In the heat source side heat exchanger (23) shown in FIG. 2, the refrigerant flowing in the vertical direction in the refrigerant chamber (S10) and the water flowing in the plurality of heat transfer tubes (72) exchange heat.

<Expansion mechanism>
Returning to FIG. 1, the expansion mechanism (24) is configured to depressurize the refrigerant. The expansion mechanism (24) is configured to be able to adjust the amount of decompression of the refrigerant. In the cooling operation, the decompression amount of the refrigerant in the expansion mechanism (24) is adjusted according to the degree of superheat of the refrigerant flowing out from the use side heat exchanger (25). In the heating operation, the refrigerant flows out from the heat source side heat exchanger (23). The decompression amount of the refrigerant in the expansion mechanism (24) is adjusted according to the degree of superheat of the refrigerant.

  In this example, the expansion mechanism (24) has a first expansion valve (41) and a second expansion valve (42), and from the heat source side heat exchanger (23) to the first expansion valve (41) in the cooling operation. The refrigerant flows toward the use side heat exchanger (25) via the heat source, and in the heating operation, the heat source side heat exchanger (23) passes through the second expansion valve (42) and the use side heat exchanger (25). It is comprised so that a refrigerant | coolant may flow toward.

  The first and second expansion valves (41, 42) are constituted by temperature-sensitive expansion valves (temperature automatic expansion valves). Specifically, the first and second expansion valves (41, 42) have first and second temperature sensing tubes (41a, 42a), respectively. The first and second temperature sensing tubes (41a, 42a) are filled with the same refrigerant as the refrigerant circulating in the refrigerant circuit (20). The first temperature sensing cylinder (41a) is attached to a pipe (in this example, the second refrigerant pipe (P2)) through which the refrigerant flowing out from the use side heat exchanger (25) flows in the cooling operation, and the second temperature sensing cylinder ( 42a) is attached to a pipe (in this example, the second refrigerant connection pipe (23b) of the heat source side heat exchanger (23)) through which the refrigerant flowing out from the heat source side heat exchanger (23) flows in the heating operation. The first and second expansion valves (41, 42) are configured such that their opening degrees are automatically adjusted according to the temperatures of the first and second temperature sensing tubes (41a, 42a), respectively. .

  The first and second expansion valves (41, 42) may be constituted by external pressure equalization type temperature automatic expansion valves. Specifically, the first and second expansion valves (41, 42) may have first and second temperature sensing tubes (41a, 42a) and first and second pressure equalizing tubes, respectively. The pressure equalizing pipe (first pressure equalizing pipe) of the first expansion valve (41) is connected to a pipe (in this example, the second refrigerant pipe (P2)) through which the refrigerant flowing out from the use side heat exchanger (25) flows in the cooling operation. The pressure equalizing pipe (second pressure equalizing pipe) of the second expansion valve (42) is a pipe (in this example, the heat source side heat exchanger (23) through which the refrigerant flowing out from the heat source side heat exchanger (23) flows in the heating operation. Of the second refrigerant connection pipe (23b). The first expansion valve (41) is configured such that the opening degree is automatically adjusted according to the temperature of the first temperature sensing cylinder (41a) and the refrigerant pressure in the first pressure equalizing pipe, and the second expansion valve (41). The valve (42) is configured such that the opening degree is automatically adjusted according to the temperature of the second temperature sensing cylinder (42a) and the refrigerant pressure in the second pressure equalizing pipe.

  In this example, the expansion mechanism (24) includes, in addition to the first and second expansion valves (41, 42), the intermediate pipe (50), the first and second main pipes (51, 52), and the first And a second bypass pipe (53, 54), first and second filters (55, 56), and first and second bypass check valves (57, 58).

  The first main pipe (51) is a pipe for flowing a refrigerant between the heat source side circuit unit (30) and the use side heat exchanger (25) via the first expansion valve (41). The first main pipe (51) is provided with a first expansion valve (41). The first main pipe (51) has one end connected to one end of the intermediate pipe (50) and the other end connected to the liquid end of the use side heat exchanger (25) via the sixth refrigerant pipe (P6). It is connected.

  The 2nd main piping (52) is piping for flowing a refrigerant between the heat source side circuit part (30) and the use side heat exchanger (25) via the 2nd expansion valve (42). The second main pipe (52) is provided with a second expansion valve (42). In this example, the second main pipe (52) has one end connected to one end of the intermediate pipe (50) and the other end connected to the other end of the heat source side circuit section (30) via the fifth refrigerant pipe (P5). (Connecting point (Q2)).

  The first bypass pipe (53) is a pipe for allowing the refrigerant to flow between the heat source side circuit unit (30) and the use side heat exchanger (25), bypassing the first expansion valve (41). In this example, the first bypass pipe (53) has one end connected to the other end of the intermediate pipe (50) and the other end connected to the use side heat exchanger (25) via the sixth refrigerant pipe (P6). Connected to the liquid end. The first bypass pipe (53) is provided with a first filter (55) and a first bypass check valve (57). The first bypass check valve (57) is a refrigerant flow from the use side heat exchanger (25) side to the heat source side circuit section (30) side (in this example, from the sixth refrigerant pipe (P6) to the intermediate pipe ( 50), only the refrigerant flow toward the other end is allowed.

  The second bypass pipe (54) is a pipe for bypassing the second expansion valve (42) and causing the refrigerant to flow between the heat source side circuit unit (30) and the use side heat exchanger (25). In this example, the second bypass pipe (54) has one end connected to the other end of the intermediate pipe (50) and the other end connected to the heat source side circuit section (30) via the fifth refrigerant pipe (P5). Connected to the other end (connection point (Q2)). The second bypass pipe (54) is provided with a second filter (56) and a second bypass check valve (58). The second bypass check valve (58) is a refrigerant flow from the heat source side circuit section (30) side to the use side heat exchanger (25) side (in this example, from the fifth refrigerant pipe (P5) to the intermediate pipe ( 50), only the refrigerant flow toward the other end is allowed.

《Use side heat exchanger》
The use side heat exchanger (25) is configured to exchange heat between the refrigerant and the use side air (air supplied to the cooling target space) conveyed by the use side fan (26). In this example, the use side heat exchanger (25) is a fin-and-tube heat exchanger.

<Heat source side circuit section>
In the heat source side circuit unit (30), the flow direction of the refrigerant passing through the heat source side heat exchanger (23) in both the cooling operation and the heating operation is changed from the first refrigerant connection tube (23a) to the second refrigerant connection tube (23b). It is comprised so that it may become the direction which goes to. In this example, the heat source side circuit unit (30) includes first to fourth connection pipes (31 to 34) and first to fourth check valves (35 to 38).

  One end of the first connection pipe (31) is connected to the first refrigerant connection pipe (23a) of the heat source side heat exchanger (23), and the other end is connected to the four-way switching valve (P3) via the third refrigerant pipe (P3). 22) connected to the third port. The first check valve (35) is provided in the first connection pipe (31) and is connected to the heat source side heat exchanger (23) from the third refrigerant pipe (P3) side (that is, the four-way switching valve (22) side). Only the flow of the refrigerant toward the first refrigerant connection pipe (23a) side is allowed.

  One end of the second connection pipe (32) is connected to the first refrigerant connection pipe (23a) of the heat source side heat exchanger (23), and the other end is connected to the expansion mechanism (24 via the fifth refrigerant pipe (P5)). ) Is connected to one end (connection point (Q3)). The second check valve (36) is provided in the second connection pipe (32) and is connected to the heat source side heat exchanger (23) from the fifth refrigerant pipe (P5) side (that is, the expansion mechanism (24) side). It is configured to allow only the refrigerant flow toward the one refrigerant connection pipe (23a) side.

  One end of the third connection wiring (33) is connected to the second refrigerant connection pipe (23b) of the heat source side heat exchanger (23), and the other end is connected to the expansion mechanism (24 via the fifth refrigerant pipe (P5)). ) Is connected to one end (connection point (Q3)). The third check valve (37) is provided on the third connection wiring (33) and extends from the second refrigerant connection pipe (23b) side of the heat source side heat exchanger (23) to the fifth refrigerant pipe (P5) side (that is, , Only the refrigerant flow toward the expansion mechanism (24 side) is allowed.

  One end of the fourth connection wiring (34) is connected to the second refrigerant connection pipe (23b) of the heat source side heat exchanger (23), and the other end is connected to the four-way switching valve (P3) via the third refrigerant pipe (P3). 22) connected to the third port. The fourth check valve (38) is provided on the fourth connection wiring (34) and extends from the second refrigerant connection pipe (23b) side of the heat source side heat exchanger (23) to the third refrigerant pipe (P3) side (that is, The refrigerant flow only toward the four-way switching valve (22 side) is allowed.

<controller>
The controller (60) controls each part of the air conditioner (10) based on detection values of various sensors (such as a temperature sensor and a pressure sensor) provided in the air conditioner (10) to control the air conditioner (10). It is comprised so that the driving | operation operation | movement may be controlled. Specifically, the controller (60) is configured to control the compressor (21), the four-way switching valve (22), and the use side fan (26).

<Cooling operation>
Next, the cooling operation will be described with reference to FIG. In the cooling operation, the four-way switching valve (22) is set to the first state. Thereby, the discharge port of the compressor (21) and the heat source side circuit part (30) communicate with each other, and the suction port of the compressor (21) communicates with the gas end of the use side heat exchanger (25). Further, the compressor (21) and the use-side fan (26) are set to the driving state. Thus, the refrigerant circulates in the refrigerant circuit (20) so that a refrigeration cycle in which the heat source side heat exchanger (23) serves as a condenser and the use side heat exchanger (25) serves as an evaporator is performed.

  Further, the amount of decompression of the refrigerant in the expansion mechanism (24) is adjusted according to the degree of superheat of the refrigerant flowing out from the gas end of the use side heat exchanger (25). In this example, according to the temperature of the first temperature sensing cylinder (41a), the superheat degree of the refrigerant flowing out from the gas end of the use side heat exchanger (25) becomes a predetermined target superheat degree. The opening degree of the one expansion valve (41) is automatically adjusted.

  The refrigerant discharged from the compressor (21) passes through the four-way switching valve (22) and flows into the heat source side circuit section (30). The refrigerant flowing into the heat source side circuit section (30) passes through the first check valve (35) and flows into the first refrigerant connection pipe (23a) of the heat source side heat exchanger (23). In the heat source side heat exchanger (23), the refrigerant flowing in from the first refrigerant connection pipe (23a) passes through the interior of the heat source side heat exchanger (23) (specifically, the refrigerant chamber (S10)) in the vertical direction. While flowing downward from the heat source side heat exchanger (23) (specifically, the heat transfer pipe (72)) dissipates heat and condenses, and then the second refrigerant connection pipe (23b) Spill from. The refrigerant that has flowed out of the second refrigerant connection pipe (23b) of the heat source side heat exchanger (23) passes through the third check valve (37) and flows into the expansion mechanism (24). The refrigerant that has flowed into the expansion mechanism (24) sequentially passes through the second filter (56), the second bypass check valve (58), and the intermediate pipe (50), and flows into the first expansion valve (41). The pressure is reduced at the first expansion valve (41). The refrigerant decompressed in the first expansion valve (41) flows into the use side heat exchanger (25) and evaporates by absorbing heat from the use side air in the use side heat exchanger (25). Thereby, utilization side air is cooled and the air-conditioning object space is cooled. The refrigerant flowing out from the use side heat exchanger (25) passes through the four-way switching valve (22) and is sucked into the compressor (21).

<Heating operation>
Next, the heating operation will be described with reference to FIG. In the heating operation, the four-way selector valve (22) is set to the second state. Thereby, the discharge port of the compressor (21) communicates with the gas end of the use side heat exchanger (25), and the suction port of the compressor (21) communicates with the heat source side circuit unit (30). Further, the compressor (21) and the use-side fan (26) are set to the driving state. Thus, the refrigerant circulates in the refrigerant circuit (20) so that a refrigeration cycle is performed in which the use side heat exchanger (25) serves as a condenser and the heat source side heat exchanger (23) serves as an evaporator.

  Moreover, the pressure reduction amount of the refrigerant in the expansion mechanism (24) is adjusted according to the degree of superheat of the refrigerant flowing out from the second refrigerant connection pipe (23b) of the heat source side heat exchanger (23). In this example, the second temperature sensing cylinder (42a) is set so that the superheat degree of the refrigerant flowing out from the second refrigerant connection pipe (23b) of the heat source side heat exchanger (23) becomes a predetermined target superheat degree. The opening degree of the second expansion valve (42) is automatically adjusted in accordance with the temperature.

  The refrigerant discharged from the compressor (21) passes through the four-way switching valve (22), flows into the use side heat exchanger (25), and dissipates heat to the use side air in the use side heat exchanger (25). Condensate. Thereby, utilization side air is heated and the air-conditioning object space is heated. The refrigerant that has flowed out of the use side heat exchanger (25) flows into the expansion mechanism (24). The refrigerant that has flowed into the expansion mechanism (24) sequentially passes through the first filter (55), the first bypass check valve (57), and the intermediate pipe (50), and flows into the second expansion valve (42). The pressure is reduced at the second expansion valve (42). The refrigerant that has flowed out of the second expansion valve (42) flows into the heat source side circuit section (30). The refrigerant flowing into the heat source side circuit section (30) passes through the second check valve (36) and flows into the first refrigerant connection pipe (23a) of the heat source side heat exchanger (23). In the heat source side heat exchanger (23), the refrigerant flowing in from the first refrigerant connection pipe (23a) passes through the interior of the heat source side heat exchanger (23) (specifically, the refrigerant chamber (S10)) in the vertical direction. While flowing downward from the heat source, it absorbs heat from the water flowing through the inside of the heat source side heat exchanger (23) (specifically, the heat transfer pipe (72)) and evaporates, and then the second refrigerant connection pipe (23b) Spill from. The refrigerant that has flowed out of the second refrigerant connection pipe (23b) of the heat source side heat exchanger (23) passes through the fourth check valve (38) and the four-way switching valve (22) in this order to the compressor (21). Inhaled.

<Effects of the embodiment>
As described above, in both the cooling operation and the heating operation, the flow direction of the refrigerant in the heat source side heat exchanger (23) can be changed from the upper side to the lower side. Therefore, even if the refrigeration oil is separated from the refrigerant flowing from the top to the bottom in the heat source side heat exchanger (23) in the heating operation, the refrigeration oil also flows from the top to the bottom due to gravity. Machine oil can flow out of the heat source side heat exchanger (23) together with the refrigerant. Thereby, accumulation of the refrigerating machine oil in the heat source side heat exchanger (23) can be suppressed.

  Further, the amount of decompression of the refrigerant in the expansion mechanism (24) is adjusted according to the degree of superheat of the refrigerant that has flowed out of the heat source side heat exchanger (23) in the heating operation, so that the heat source side heat exchanger ( In 23), the refrigerant can be reliably evaporated. Thereby, it is possible to prevent the occurrence of a phenomenon (so-called liquid back phenomenon) in which liquid refrigerant flows out of the heat source side heat exchanger (23) and is sucked into the compressor (21) in the heating operation.

  Further, the decompression amount of the refrigerant in the expansion mechanism (24) is adjusted in accordance with the degree of superheat of the refrigerant that has flowed out of the use side heat exchanger (25) in the cooling operation, so that the use side heat exchanger ( In 25), the refrigerant can be reliably evaporated. Thereby, it is possible to prevent the occurrence of a phenomenon (so-called liquid back phenomenon) in which the liquid refrigerant flows out from the use side heat exchanger (25) and is sucked into the compressor (21) in the cooling operation.

  Moreover, the heat source side heat exchanger (23) can be easily disassembled by configuring the heat source side heat exchanger (23) with a shell-and-tube heat exchanger. Thereby, maintenance and inspection of the heat source side heat exchanger (23) can be facilitated.

(Modification of air conditioner)
Next, a modification of the air conditioner (10) will be described with reference to FIG. The air conditioner (10) shown in FIG. 5 is different from the air conditioner (10) shown in FIG. 1 in the configuration of the heat source side heat exchanger (23) and the heat source side circuit unit (30). In addition, the other structure of the air conditioner (10) shown in FIG. 5 is the same as that of the air conditioner (10) shown in FIG.

《Heat source side heat exchanger》
In the example of FIG. 5, the first refrigerant connection pipe (23a) of the heat source side heat exchanger (23) includes a condensation side refrigerant connection pipe (81) and a plurality (six in this example) of evaporation side refrigerant connection pipes ( 82). The heat source side heat exchanger (23) is configured such that the refrigerant flowing from the condensation side refrigerant connection pipe (81) or the plurality of evaporation side refrigerant connection pipes (82) passes through the inside of the heat source side heat exchanger (23) from above. And flows out from the second refrigerant connecting pipe (23b).

  Specifically, in the example of FIG. 5, the heat source side heat exchanger (23) is configured by a shell-and-tube heat exchanger (see FIG. 2). For example, the condensation side refrigerant connection pipe (81) and the plurality of evaporation side refrigerant connection pipes (82) are provided on the upper part of the shell (71) shown in FIG. 2 and communicate with the refrigerant chamber (S10). The other configuration of the heat source side heat exchanger (23) may be the same as the configuration of the heat source side heat exchanger (23) shown in FIG. In the heat source side heat exchanger (23) configured as described above, heat is exchanged between the refrigerant flowing in the vertical direction in the refrigerant chamber (S10) and the refrigerant flowing in the plurality of heat transfer tubes (72).

<Heat source side circuit section>
In the example of FIG. 5, the heat source side circuit unit (30) includes a flow divider (80) for diverting the refrigerant. The flow divider (80) has one inflow port and a plurality of (in this example, six) outflow ports, and is configured to divert refrigerant flowing in from the inflow port and outflow from the plurality of outflow ports. Yes. In the heat source side circuit unit (30), the refrigerant discharged from the compressor (21) in the cooling operation is supplied to the condensing side refrigerant connection pipe (81) of the heat source side heat exchanger (23), and is expanded in the heating operation. The refrigerant that has flowed out of the mechanism (24) passes through the flow divider (80) and is supplied to the plurality of evaporation side refrigerant connection pipes (82) of the heat source side heat exchanger (23).

  Specifically, in the example of FIG. 5, one end of the first connection pipe (31) of the heat source side circuit section (30) is connected to the condensation side refrigerant connection pipe (81) of the heat source side heat exchanger (23). The other end is connected to the third port of the four-way switching valve (22) via the third refrigerant pipe (P3). One end of the second connection pipe (32) of the heat source side circuit section (30) is connected to the plurality of evaporation side refrigerant connection pipes (82) via the flow divider (80), and the other end is connected to the fifth refrigerant pipe ( It is connected to one end (connection point (Q3)) of the expansion mechanism (24) via P5). That is, one end of the second connection pipe (32) is connected to one inlet of the flow divider (80), and a plurality of outlets of the flow divider (80) are connected to a plurality of evaporation side refrigerant connection pipes (82), respectively. Has been. The second check valve (36) is provided between the flow divider (80) and the fifth refrigerant pipe (P5) in the second connection pipe (32). The other configuration of the heat source side circuit unit (30) is the same as the configuration of the heat source side circuit unit (30) shown in FIG.

<Effects of Modification of Embodiment>
As described above, the refrigerant flowing out from the expansion mechanism (24) in the heating operation passes through the flow divider (80) and is supplied to the plurality of evaporation side refrigerant connection pipes (82) of the heat source side heat exchanger (23). As a result, the evaporation of the refrigerant in the heat source side heat exchanger (23) can be promoted. Thereby, it is possible to make it difficult to generate a phenomenon (so-called liquid back phenomenon) in which the liquid refrigerant flows out of the heat source side heat exchanger (23) and is sucked into the compressor (21) in the heating operation.

(Other embodiments)
In the above description, the case where the heat source side heat exchanger (23) is configured by a shell and tube type heat exchanger is taken as an example, but the heat source side heat exchanger (23) is a shell and tube type heat exchanger. For example, it may be configured by a plate-type heat exchanger. Also in this case, the refrigerant flowing in from the first refrigerant connection pipe (23a) flows from the upper side to the lower side of the heat source side heat exchanger (23) (first flow path) and flows downward from the second refrigerant connection pipe (23b). The water flowing out from the first water connection pipe (23c) passes through the inside of the heat source side heat exchanger (23) (second flow path different from the first flow path) and passes through the second water connection pipe ( 23d), the refrigerant flowing vertically in the heat source side heat exchanger (23) (first flow path) and the water flowing in the heat source side heat exchanger (23) (second flow path) The heat source side heat exchanger (23) can be configured to exchange heat.

  In the above description, the case where the expansion mechanism (24) is constituted by the first and second expansion valves (41, 42) that are temperature-sensitive expansion valves (temperature automatic expansion valves) is taken as an example. The expansion mechanism (24) may be configured by an electronic expansion valve (motor-operated valve) whose opening degree is adjusted by the control of the controller (60). As described above, when the expansion mechanism (24) is configured by the electronic expansion valve, in the cooling operation, the electronic expansion that configures the expansion mechanism (24) according to the degree of superheat of the refrigerant that has flowed out of the use side heat exchanger (25). The opening degree of the valve is adjusted, and in the heating operation, the opening degree of the electronic expansion valve constituting the expansion mechanism (24) is adjusted according to the degree of superheat of the refrigerant flowing out from the heat source side heat exchanger (23).

  Moreover, you may implement combining the above embodiment and modification suitably. The above embodiments and modifications are essentially preferable examples, and are not intended to limit the scope of the present invention, its application, or its use.

  As described above, the above-described air conditioner is useful as an air conditioner that performs air conditioning in the air-conditioning target space.

DESCRIPTION OF SYMBOLS 10 Air conditioner 20 Refrigerant circuit 21 Compressor 22 Four-way switching valve 23 Heat source side heat exchanger 23a First refrigerant connection pipe 23b Second refrigerant connection pipe 23c First water connection pipe 23d Second water connection pipe 24 Expansion mechanism 25 Use side Heat exchanger 26 Use side fan 30 Heat source side circuit unit 41 First expansion valve 42 Second expansion valve 60 Controller 71 Shell 72 Heat transfer pipe 73 Support base 80 Divider 81 Condensation side refrigerant connection pipe 82 Evaporation side refrigerant connection pipe S10 Refrigerant chamber S11 1st header space S12 2nd header space S15 1st water chamber S16 2nd water chamber

Claims (4)

A refrigerant circuit (20) having a compressor (21), a heat source side heat exchanger (23), an expansion mechanism (24), and a use side heat exchanger (25), wherein the refrigerant circuit (20) has a heat source side; A cooling operation in which the refrigerant circulates so that the heat exchanger (23) becomes a condenser and the use side heat exchanger (25) becomes an evaporator, and the heat source side heat exchanger (23) in the refrigerant circuit (20) An air conditioner that switches between a heating operation in which the refrigerant circulates so that the use side heat exchanger (25) becomes a condenser,
The heat source side heat exchanger (23) has a first refrigerant connection pipe (23a) and a second refrigerant connection pipe (23b), and the refrigerant flowing in from the first refrigerant connection pipe (23a) is on the heat source side. The heat exchanger (23) is configured to flow from the upper side to the lower side and flow out from the second refrigerant connection pipe (23b),
The refrigerant circuit (20) has a heat source side circuit part (30) including the heat source side heat exchanger (23),
In the heat source side circuit section (30), the flow direction of the refrigerant passing through the heat source side heat exchanger (23) in both the cooling operation and the heating operation is changed from the first refrigerant connection pipe (23a) to the second refrigerant connection. An air conditioner configured to be in a direction toward the pipe (23b). In claim 1,
In the heating operation, the air conditioner is characterized in that the amount of decompression of the refrigerant in the expansion mechanism (24) is adjusted in accordance with the degree of superheat of the refrigerant that has flowed out of the heat source side heat exchanger (23). In claim 1 or 2,
The air conditioner, wherein the heat source side heat exchanger (23) is configured by a shell-and-tube heat exchanger. In any one of Claims 1-3,
The first refrigerant connection pipe (23a) of the heat source side heat exchanger (23) includes a condensation side refrigerant connection pipe (81) and a plurality of evaporation side refrigerant connection pipes (82).
The heat source side heat exchanger (23) is configured such that the refrigerant flowing from the condensation side refrigerant connection pipe (81) or the plurality of evaporation side refrigerant connection pipes (82) moves upward in the heat source side heat exchanger (23). Configured to flow downward from the second refrigerant connection pipe (23b),
The heat source side circuit unit (30) has a flow divider (80) for diverting the refrigerant, and the refrigerant discharged from the compressor (21) in the cooling operation is condensed in the heat source side heat exchanger (23). The refrigerant that is supplied to the side refrigerant connection pipe (81) and flows out of the expansion mechanism (24) in the heating operation passes through the flow divider (80), and then the plurality of evaporation sides of the heat source side heat exchanger (23) An air conditioner configured to be supplied to the refrigerant connection pipe (82).

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