Refrigeration cycle device

Abstract

A refrigeration cycle device (100) comprises a heat-source heat exchanger (13), a utilization heat exchanger (23), and a bridge circuit (40). The heat-source heat exchanger (13) has a refrigerant inlet pipe (13a) and a refrigerant outlet pipe (13b). The bridge circuit (40) causes the refrigerant to flow so that the refrigerant always flows into the first heat exchanger through the refrigerant inlet pipe and flows out of the first heat exchanger through the refrigerant outlet pipe. The first heat exchanger has a flow divider (50). A flow divider body (51) of the flow divider (50) has one intake port (53) and a plurality of discharge ports (54). A plurality of refrigerant paths (61) in the heat-source heat exchanger (13) include a lowest path (61L), which is disposed at the lowest height (H1). The heights (H0) of the plurality of discharge ports (54) are all greater than the height (H1) of the lowest path.

Description

Refrigeration cycle device

[0001] The present disclosure relates to a refrigeration cycle device having a heat exchanger that handles a zeotropic refrigerant mixture, in which a counterflow in which the flow directions of the zeotropic refrigerant mixture and air oppose each other is realized in the heat exchanger.

[0002] The refrigeration cycle device disclosed in Patent Document 1 (Japanese Patent Application Laid-Open No. 2009-222362) has a bridge circuit. Such a bridge circuit may be mounted on a refrigeration cycle device that handles a zeotropic refrigerant mixture. In this case, the bridge circuit functions to always keep the flow direction of the refrigerant flowing through the heat source heat exchanger the same regardless of whether the refrigeration cycle device executes either cold heat utilization operation or warm heat utilization operation, thereby realizing counterflow in the heat source heat exchanger.

[0003] In a general refrigeration cycle device that does not intend to always bring about counterflow in the heat exchanger, the flow direction of the refrigerant is reversed when the heat exchanger functions as a condenser and when it functions as an evaporator. When a diverter is provided in the heat exchanger of such a refrigeration cycle device, it is installed at the refrigerant inlet of the heat exchanger used as an evaporator. At this time, the diverter distributes the low-pressure gas-liquid two-phase refrigerant flowing into the refrigerant inlet to a plurality of refrigerant paths of the heat exchanger functioning as an evaporator, thereby making the evaporation of the low-pressure gas-liquid two-phase refrigerant in the heat exchanger uniform. On the other hand, when the heat exchanger functions as a condenser, it is necessary to smoothly move the liquid refrigerant to the diverter so that the liquid refrigerant does not accumulate in the heat exchanger. To facilitate this movement, the diverter body is often arranged at a position lower than the refrigerant paths of the heat exchanger.

[0004] If the same design concept is applied, the diverter body will also be arranged at a position lower than the refrigerant paths of the heat exchanger in a refrigeration cycle device that intends to always bring about counterflow in the heat exchanger.

[0005] However, when a heat exchanger that always receives countercurrent is used as a condenser, the gaseous refrigerant passes through a flow divider before condensing within the heat exchanger. Gaseous refrigerants tend to experience significant pressure loss through piping. Therefore, if multiple flow divider pipes extend upward over long distances from a low-lying flow divider body, the high-pressure gaseous refrigerant may not reach the refrigerant path located at a higher position due to pressure loss.

[0006] The refrigeration cycle device in the first aspect comprises a four-way switching valve, a first heat exchanger, a second heat exchanger, and a refrigerant flow straightening unit. The four-way switching valve switches between first operation and second operation. The first heat exchanger has a refrigerant inlet pipe and a refrigerant outlet pipe. The first heat exchanger functions as a condenser in first operation and as an evaporator in second operation. The second heat exchanger functions as an evaporator in first operation and as a condenser in second operation. The refrigerant flow straightening unit causes the refrigerant to flow into the first heat exchanger at the refrigerant inlet pipe and out of the first heat exchanger at the refrigerant outlet pipe in both first and second operation.

[0007] The first heat exchanger further comprises a flow divider and a heat exchanger body. The flow divider divides the refrigerant. The heat exchanger body has multiple refrigerant paths through which the refrigerant passes. The flow divider comprises a flow divider body and multiple flow divider pipes. The flow divider body has one inlet and multiple outlets. One inlet is connected to a refrigerant inlet pipe. The multiple flow divider pipes each connect to multiple outlets and multiple refrigerant paths. The multiple refrigerant paths include a lowest-level path located at the lowest height and a highest-level path located at the highest height. The height of each of the multiple outlets is higher than the height of the lowest-level path.

[0008] In this configuration, the height of the discharge port is higher than the height of the lowest path. Therefore, regardless of whether it is the first or second operation, the refrigerant moves from top to bottom, making deceleration less likely and suppressing refrigerant stagnation. As a result, the occurrence of refrigerant flow unevenness can be suppressed.

[0009] The refrigeration cycle device in the second perspective is the same as the refrigeration cycle device in the first perspective, wherein the heights of all of the multiple discharge ports are higher than the intermediate height, which is the average of the heights of the lowest and highest passes.

[0010] In this configuration, the outlet is higher than the intermediate height. Therefore, refrigerant deceleration is less likely to occur, thus suppressing refrigerant flow deviation.

[0011] The refrigeration cycle device according to the third perspective is a refrigeration cycle device according to the first or second perspective, wherein the height of each of the multiple outlets is lower than the height of the upper end of the heat exchanger body.

[0012] With this configuration, the height of the outlet is lower than the height of the top of the heat exchanger body. Therefore, the first heat exchanger can be made compact.

[0013] The refrigeration cycle device of the fourth perspective is a refrigeration cycle device of any one of the first, second, or third perspectives, wherein the heat exchanger body has multiple refrigerant path inlets. The multiple refrigerant path inlets are the points where the refrigerant flows into the multiple refrigerant paths. The height of the lowest path and the height of the highest path are the heights of one of the multiple path inlets.

[0014] In this configuration, the height of the refrigerant path is the same as the height of the refrigerant path inlet. Therefore, the positional relationship when the refrigerant exiting the outlet enters the refrigerant path inlet can be appropriately determined.

[0015] The refrigeration cycle device of the fifth perspective is a refrigeration cycle device of any one of the first, second, or fourth perspectives, wherein the heat exchanger body has multiple refrigerant path outlets. The multiple refrigerant path outlets are the points where the refrigerant flows out from the multiple refrigerant paths. The height of each of the multiple outlets is higher than the height of the highest path among the multiple refrigerant path outlets.

[0016] In this configuration, the height of the outlet is higher than the height of the highest-level path outlet. Therefore, refrigerant deceleration is less likely to occur, thus suppressing the occurrence of refrigerant flow deviation.

[0017] The refrigeration cycle device of the sixth aspect is a refrigeration cycle device of any one of the first to fifth aspects, wherein the first heat exchanger further has a merging unit. The merging unit receives refrigerant from the heat exchanger body. The refrigerant outlet pipe is connected to the merging unit at the outlet pipe connection. The height of the outlet pipe connection is lower than the height of the lowest of the multiple refrigerant path outlets.

[0018] In this configuration, the height of the outlet pipe connection is lower than the lowest pass outlet. Therefore, the refrigerant that has finished heat exchange is efficiently discharged from the junction.

[0019] The refrigeration cycle device of the seventh aspect is a refrigeration cycle device of any one of the first to sixth aspects, wherein the first heat exchanger is a heat source heat exchanger, and the second heat exchanger is a utilization heat exchanger.

[0020] In this configuration, the first heat exchanger is a heat source heat exchanger. Therefore, in the heat source heat exchanger, counterflow can be achieved where the directions of flow of the refrigerant and air are opposite.

[0021] The refrigeration cycle device of the eighth perspective is a refrigeration cycle device of any one of the first to sixth perspectives, wherein the first heat exchanger is a utilization heat exchanger, and the second heat exchanger is a heat source heat exchanger.

[0022] In this configuration, the first heat exchanger is a utilization heat exchanger. Therefore, in the utilization heat exchanger, counterflow can be achieved where the directions of flow of the refrigerant and air are opposite.

[0023] The refrigeration cycle device of the ninth aspect is a refrigeration cycle device of any one of the first to eighth aspects, wherein the refrigerant rectifier is a bridge circuit having a plurality of check valves.

[0024] In this configuration, the refrigerant rectification section is configured as a bridge circuit by a check valve. Therefore, the check valve effectively suppresses the backflow of the refrigerant.

[0025] The refrigeration cycle device of the tenth perspective is the refrigeration cycle device of the ninth perspective, wherein the height of each of the multiple discharge ports is higher than the height of each of the multiple check valves.

[0026] In this configuration, the height of the outlet is higher than the height of any of the check valves. Therefore, the check valves can easily utilize the required differential pressure.

[0027] The refrigeration cycle device of the 11th aspect is a refrigeration cycle device of any one of the 1st to 10th aspects, wherein the number of outlets is 4 or more and 8 or less.

[0028] In this configuration, the number of outlets is between four and eight. Therefore, the refrigerant flow can be efficiently divided without excessively increasing the flow resistance experienced by the refrigerant.

[0029] This is a schematic diagram showing the configuration of the refrigeration cycle device 100 according to the first embodiment. This is a schematic diagram showing the configuration of the heat source heat exchanger 13. This is a schematic diagram showing the configuration of the heat exchanger body 60. This is a schematic diagram showing the counterflow of refrigerant R and airflow AF in the heat source heat exchanger 13. This is a graph showing the temperature change of refrigerant R and airflow AF in cooling operation. This is a graph showing the temperature change of refrigerant R and airflow AF in heating operation. This is a schematic diagram showing the detailed structure of the heat source heat exchanger 13. This is a schematic diagram showing the configuration of the refrigeration cycle device 100A according to the second embodiment. This is a schematic diagram showing the configuration of the refrigeration cycle device 100B according to the third embodiment.

[0030] <First Embodiment> (1) Overall Configuration Diagram 1 shows the configuration of the refrigeration cycle device 100 according to the first embodiment. The refrigeration cycle device 100 provides the user with cold heat or hot heat obtained from a heat source by circulating a refrigerant R. In cold heat utilization operation, the refrigeration cycle device 100 provides cold heat to the user. In hot heat utilization operation, the refrigeration cycle device 100 provides cold heat to the user. The refrigeration cycle device 100 can be configured in the form of an air conditioner, refrigerator, freezer, water heater, floor heating system, etc. When the refrigeration cycle device 100 is an air conditioner, cold heat utilization operation and hot heat utilization operation correspond to cooling operation and heating operation, respectively. The refrigeration cycle device 100 has a heat source unit 10, a utilization unit 20, and a group of connecting pipes 30.

[0031] (2) Detailed composition (2-1) Refrigerant R Refrigerant R is a non-azeotropic mixed refrigerant. A non-azeotropic mixed refrigerant is a refrigerant made by mixing multiple refrigerant components with different boiling points. Refrigerant R is, for example, R454C. R454C is a mixture of R32 and R1234yf.

[0032] Non-azeotropic refrigerant mixtures exhibit significant temperature glide. Temperature glide refers to the range of temperature changes observed during the evaporation or condensation of a refrigerant R. During the evaporation of a non-azeotropic refrigerant mixture, the low-boiling point components evaporate first, followed by the high-boiling point components. During the condensation of a non-azeotropic refrigerant mixture, the high-boiling point components condense first, followed by the low-boiling point components. The presence of multiple boiling points in this way causes significant temperature glide.

[0033] (2-2) Heat source unit 10 The heat source unit 10 obtains cold or hot energy from the air, which is the heat source. The heat source unit 10 includes a compressor 11, a four-way switching valve 12, a heat source heat exchanger 13, a heat source fan 14, a bridge circuit 40, a heat source expansion valve 15, an accumulator 16, a liquid shut-off valve 17, and a gas shut-off valve 18.

[0034] (2-2-1) Compressor 11 The compressor 11 has an intake pipe 11a and a discharge pipe 11b. The compressor 11 draws in refrigerant R in a low-pressure gas state from the intake pipe 11a, compresses the refrigerant R, and discharges the refrigerant R in a high-pressure gas state from the discharge pipe 11b.

[0035] (2-2-2) Four-way switching valve 12 The four-way switching valve 12 switches between cooling operation and heating operation by switching the direction of travel of the refrigerant R. When performing cooling operation, the four-way switching valve 12 realizes the connection shown by the solid line in Figure 1 and causes the refrigerant R to travel in the direction indicated by the arrow CO. When performing heating operation, the four-way switching valve 12 realizes the connection shown by the dashed line in Figure 1 and causes the refrigerant R to travel in the direction indicated by the arrow HO.

[0036] (2-2-3) Heat source heat exchanger 13 and heat source fan 14 (2-2-3-1) Function The heat source heat exchanger 13 performs heat exchange between the air, which is the heat source, and the refrigerant R, thereby allowing the refrigerant R to acquire cooling or heating. When operating for cooling, the heat source heat exchanger 13 functions as a condenser or heat radiator for the refrigerant R, allowing the refrigerant R to acquire cooling. When operating for heating, the heat source heat exchanger 13 functions as an evaporator or heat absorber for the refrigerant R, allowing the refrigerant R to acquire heating.

[0037] The heat source heat exchanger 13 has a refrigerant inlet pipe 13a and a refrigerant outlet pipe 13b. The refrigerant R enters the heat source heat exchanger 13 through the refrigerant inlet pipe 13a and exits the heat source heat exchanger 13 through the refrigerant outlet pipe 13b. The heat source fan 14 promotes heat exchange between the air and the refrigerant R by generating an airflow that passes through the heat source heat exchanger 13.

[0038] In the following, the term "condenser" may include the use of a refrigerant R as a heat exchanger without a phase transition, and the term "evaporator" may include the use of a refrigerant R as a heat absorber without a phase transition.

[0039] (2-2-3-2) Structural diagram 2 shows the structure of the heat source heat exchanger 13. In addition to the refrigerant inlet pipe 13a and the refrigerant outlet pipe 13b, the heat source heat exchanger 13 has a flow divider 50, a heat exchanger body 60, and a flow merging device 70.

[0040] The flow divider 50 has a flow divider body 51 to which the refrigerant inlet pipe 13a is connected, and a plurality of flow divider pipes 56 extending from the flow divider body 51. The flow divider body 51 has one intake port 53 and a plurality of outlet ports 54. The number of outlet ports 54 is between 4 and 8. The refrigerant inlet pipe 13a is connected to the intake port 53. The plurality of flow divider pipes 56 are connected to their respective outlet ports 54. The refrigerant R flowing into the refrigerant inlet pipe 13a is divided into the plurality of flow divider pipes 56.

[0041] The heat exchanger body 60 is a part that performs heat exchange between the refrigerant R and air. The heat exchanger body 60 has a plurality of refrigerant paths 61 through which the refrigerant R flows. The plurality of refrigerant paths 61 include the lowest path 61L arranged at the lowest height and the highest path 61H arranged at the highest height. Each refrigerant path 61 has a refrigerant path inlet 62 and a refrigerant path outlet 63. The refrigerant path inlet 62 is the location where the refrigerant R flows into the refrigerant path 61. The refrigerant path outlet 63 is the location where the refrigerant R flows out of the refrigerant path 61. The plurality of refrigerant path inlets 62 are each connected to a flow splitting pipe 56.

[0042] The confluence unit 70 has a plurality of confluence pipes 75 and a confluence unit body 76. Each confluence pipe 75 connects one refrigerant path outlet 63 and the confluence unit body 76. The confluence unit body 76 has an outlet pipe connection portion 77 to which the refrigerant outlet pipe 13b is connected. The confluence unit 70 combines the refrigerant R received from the plurality of refrigerant paths 61 and discharges it to the refrigerant outlet pipe 13b.

[0043] FIG. 3 shows the configuration of the heat exchanger body 60. The heat exchanger body 60 has a plurality of heat transfer tubes 65 and a plurality of fins 67. Each heat transfer tube 65 is inserted into the through holes of all the fins 67. The ends of two adjacent heat transfer tubes 65 are connected by a U-shaped tube 66. One refrigerant path 61 is constituted by a plurality of heat transfer tubes 65 and a plurality of U-shaped tubes 66.

[0044] (2-2-3-3) Countercurrent FIG. 4 schematically shows the countercurrent realized in the heat source heat exchanger 13 and the heat source fan 14. Countercurrent means that the traveling direction of the refrigerant R is opposite to the traveling direction of the air flow AF. Realizing countercurrent in the heat source heat exchanger 13 is important for heat-exchanging the refrigerant R having a large temperature gradient.

[0045] The refrigerant R flows into the heat source heat exchanger 13 from the refrigerant inlet pipe 13a, is branched by the flow divider 50, passes through a plurality of refrigerant paths 61, merges at the merger 70, and flows out of the heat source heat exchanger 13 from the refrigerant outlet pipe 13b. Each refrigerant path 61 has a plurality of heat transfer tubes 65, which include the heat transfer tubes 65 arranged in the first row L1 on the side of the fin front end 671 of the heat source heat exchanger 13 and the heat transfer tubes 65 arranged in the second row L2 on the side of the fin rear end 672. After flowing in from the refrigerant inlet pipe 13a, the refrigerant R always passes through the heat transfer tubes 65 in the first row L1 first, then passes through the heat transfer tubes 65 in the second row L2, and finally flows out from the refrigerant outlet pipe 13b. In other words, the refrigerant R travels in the -y direction from the side of the fin front end 671 to the side of the fin rear end 672.

[0046] On the other hand, the air flow AF generated by the heat source fan 14 passes between adjacent fins 67 while traveling in the +y direction from the side of the fin rear end 672 to the side of the fin front end 671.

[0047] (2-2-4) Bridge circuit 40 Returning to FIG. 1, the bridge circuit 40 is for always realizing a countercurrent flow of the refrigerant R and the air flow AF in the heat source heat exchanger 13. Usually, in a refrigerant circuit without the bridge circuit 40, each time the cold heat utilization operation and the warm heat utilization operation are switched, the direction of the refrigerant R flowing through the heat exchanger is reversed. In contrast, in the refrigeration cycle device 100 of the present embodiment, regardless of whether the cold heat utilization operation or the warm heat utilization operation is executed, the bridge circuit 40 always makes the traveling direction of the refrigerant R in the heat source heat exchanger 13 the same. By the bridge circuit 40, regardless of whether the traveling direction of the refrigerant R is the arrow CO or the arrow HO, the refrigerant R always enters the heat source heat exchanger 13 at the refrigerant inlet pipe 13a and always exits the heat source heat exchanger 13 at the refrigerant outlet pipe 13b.

[0048] The bridge circuit 40 has a first node A, a second node B, a third node C, and a fourth node D. The first node A is connected to the refrigerant outlet pipe 13b. The second node B is connected to the compressor 11 via the four-way switching valve 12. The third node C is connected to the refrigerant inlet pipe 13a. The fourth node D is connected to the heat source expansion valve 15.

[0049] Furthermore, the bridge circuit 40 has a first channel AB extending from the first node A to the second node B, a second channel BC extending from the second node B to the third node C, a third channel DC extending from the fourth node D to the third node C, and a fourth channel AD extending from the first node A to the fourth node D.

[0050] The bridge circuit 40 includes a first check valve 41, a second check valve 42, a third check valve 43, and a fourth check valve 44. These check valves maintain the same direction of flow for the refrigerant R in the installed flow path and prevent backflow of the refrigerant R. The first check valve 41 is provided in the first flow path AB and allows the refrigerant R to flow only in the direction from the first node A to the second node B. The second check valve 42 is provided in the second flow path BC and allows the refrigerant R to flow only in the direction from the second node B to the third node C. The third check valve 43 is provided in the third flow path DC and allows the refrigerant R to flow only in the direction from the fourth node D to the third node C. The fourth check valve 44 is provided in the fourth flow path AD and allows the refrigerant R to flow only in the direction from the first node A to the fourth node D.

[0051] (2-2-5) Heat source expansion valve 15 The heat source expansion valve 15 reduces the pressure of the refrigerant R. The heat source expansion valve 15 is composed of an electrically operated valve that can adjust the degree of opening. When the degree of opening of the heat source expansion valve 15 is set to a small size, the amount of refrigerant R that can pass through the heat source expansion valve 15 decreases, and the pressure of the refrigerant R after passing through the heat source expansion valve 15 decreases.

[0052] (2-2-6) Accumulator 16 The accumulator 16 stores only the liquid component contained in the refrigerant R inside, allowing only the gaseous component to pass through. The accumulator 16 is connected to the suction pipe 11a of the compressor 11, and prevents the liquid component of the refrigerant R from damaging the compressor 11.

[0053] (2-2-7) Liquid shut-off valve 17 and gas shut-off valve 18 The liquid shut-off valve 17 and gas shut-off valve 18 are for manually shutting off the movement of the refrigerant R. The liquid shut-off valve 17 and gas shut-off valve 18 are opened and closed manually by the installer of the refrigeration cycle device 100.

[0054] (2-3) Utilization Unit 20 The utilization unit 20 provides the user with the cold or heat acquired by the heat source unit 10 from the heat source. The utilization unit 20 has a utilization heat exchanger 23 and a utilization fan 24.

[0055] (2-3-1) Utilization Heat Exchanger 23 The utilization heat exchanger 23 provides cooling or heating to the user by exchanging heat with the refrigerant R, such as the air in the user's environment or the water used by the user. When operating for cooling, the utilization heat exchanger 23 functions as an evaporator for the refrigerant R and provides cooling to the user. When operating for heating, the utilization heat exchanger 23 functions as a condenser for the refrigerant R and provides heating to the user. As mentioned above, the term "condenser" here includes the use of the refrigerant R as a heat sink without a phase transition, and the term "evaporator" may include the use of the refrigerant R as a heat absorber without a phase transition.

[0056] (2-3-2) Utilization fan 24 The utilization fan 24 is provided when the user utilizes cooling or heating through the air. The utilization fan 24 promotes heat exchange between the air and the refrigerant R by generating an airflow that passes through the utilization heat exchanger 23.

[0057] (2-4) Connecting piping group 30 The connecting piping group 30 constitutes a circulation path for the refrigerant R by connecting the heat source unit 10 and the utilization unit 20. The connecting piping group 30 has a liquid connecting pipe 31 and a gas connecting pipe 32. The liquid connecting pipe 31 mainly allows the refrigerant R to pass through in a liquid state or a gas-liquid two-phase state. The liquid connecting pipe 31 connects the liquid shut-off valve 17 and the utilization heat exchanger 23. The gas connecting pipe 32 mainly allows the refrigerant R to pass through in a high-pressure gas state or a low-pressure gas state. The gas connecting pipe 32 connects the gas shut-off valve 18 and the utilization heat exchanger 23.

[0058] (3) Overall operation (3-1) Cooling operation When performing cooling operation, the four-way switching valve 12 makes the connection shown by the solid line in Figure 1 and moves the refrigerant R in the direction indicated by the arrow CO.

[0059] The compressor 11 draws in refrigerant R in a low-pressure gas state from the suction pipe 11a and discharges refrigerant R in a high-pressure gas state from the discharge pipe 11b. The refrigerant R in the high-pressure gas state passes through the four-way switching valve 12 and reaches the second node B of the bridge circuit 40. After that, the refrigerant R passes through the second check valve 42 and reaches the third node C. After that, the refrigerant R enters the heat source heat exchanger 13 at the refrigerant inlet pipe 13a. The heat source heat exchanger 13 generates refrigerant R in a high-pressure liquid state by condensing the refrigerant R using the cold energy of the air. The refrigerant R in the high-pressure liquid state exits the heat source heat exchanger 13 from the refrigerant outlet pipe 13b and then reaches the first node A. After that, the refrigerant R passes through the fourth check valve 44 and reaches the fourth node D. After that, the refrigerant R in the high-pressure liquid state is depressurized at the heat source expansion valve 15 and becomes refrigerant R in a gas-liquid two-phase state. Subsequently, the refrigerant R passes through the liquid shut-off valve 17 and the liquid connecting pipe 31 and reaches the utilization heat exchanger 23. The utilization heat exchanger 23 provides the user with the cooling energy carried by the refrigerant R by evaporating the refrigerant R in a gas-liquid two-phase state, and also generates refrigerant R in a low-pressure gas state. After that, the refrigerant R passes through the gas connecting pipe 32, the gas shut-off valve 18, the four-way switching valve 12, and the accumulator 16 in sequence, and is then drawn into the compressor 11 in the suction pipe 11a.

[0060] (3-2) Thermal Energy Utilization Operation When performing thermal energy utilization operation, the four-way switching valve 12 is connected as shown by the dashed line in Figure 1, and the refrigerant R is advanced in the direction indicated by the arrow HO.

[0061] The compressor 11 draws in refrigerant R in a low-pressure gas state from the suction pipe 11a and discharges refrigerant R in a high-pressure gas state from the discharge pipe 11b. The refrigerant R in the high-pressure gas state passes sequentially through the four-way switching valve 12, the gas shut-off valve 18, and the gas connecting pipe 32 to reach the utilization heat exchanger 23. The utilization heat exchanger 23 condenses the refrigerant R in the high-pressure gas state, providing the heat carried by the refrigerant R to the user and generating refrigerant R in a high-pressure liquid state. Subsequently, the refrigerant R passes through the liquid connecting pipe 31 and the liquid shut-off valve 17 to reach the heat source expansion valve 15. Subsequently, the refrigerant R in the high-pressure liquid state is depressurized in the heat source expansion valve 15 and becomes refrigerant R in a gas-liquid two-phase state. Subsequently, the refrigerant R passes sequentially through the fourth node D, the third check valve 43, and the third node C. Subsequently, the refrigerant R enters the heat source heat exchanger 13 at the refrigerant inlet pipe 13a. The heat source heat exchanger 13 generates low-pressure gaseous refrigerant R by evaporating it using the heat of the air. The low-pressure gaseous refrigerant R exits the heat source heat exchanger 13 through the refrigerant outlet pipe 13b and then reaches the first node A. After that, the refrigerant R passes through the first check valve 41 and reaches the second node B. After that, the refrigerant R passes through the four-way switching valve 12 and the accumulator 16 in sequence and is then drawn into the compressor 11 in the suction pipe 11a.

[0062] (3-3) Counterflow effect in heat source heat exchanger 13 Figures 5 and 6 show examples of temperature changes of the refrigerant R and airflow AF in the heat source heat exchanger 13. The horizontal axis shows the position y in the y direction. y1 is the position of the rear end 672 of the fin, and y2 is the position of the front end 671 of the fin. The vertical axis shows the temperature T of the refrigerant R and airflow AF. The numerical values ​​of temperature T shown are for illustrative purposes only.

[0063] Figure 5 shows the temperature change during cooling operation. This figure assumes that the heat source heat exchanger 13 is creating counterflow between the refrigerant R and the airflow AF. The airflow AF moves from position y1 at the rear end 672 of the fin to position y2 at the front end 671 of the fin. On the other hand, the refrigerant R moves from position y2 at the front end 671 of the fin to position y1 at the rear end 672 of the fin.

[0064] The heat source heat exchanger 13 functions as a condenser. Inside the heat source heat exchanger 13, the refrigerant R loses heat to the airflow AF. As a result, the temperature of the refrigerant R decreases as it moves from position y2 to position y1. Since the airflow AF receives heat from the refrigerant R, the temperature of the airflow AF increases as it moves from position y1 to position y2.

[0065] The temperature difference ΔT1 between the refrigerant R and the airflow AF at position y1, and the temperature difference ΔT2 between the refrigerant R and the airflow AF at position y2, are both sufficiently large. Therefore, heat transfer from the refrigerant R to the airflow AF is carried out without any problems throughout the entire area of ​​the heat source heat exchanger 13.

[0066] Figure 6 shows the temperature change during thermal energy utilization operation. The heat source heat exchanger 13 functions as an evaporator. In the heat source heat exchanger 13, the refrigerant R receives heat from the airflow AF, so as the airflow AF moves from position y1 to position y2, the temperature of the airflow AF decreases.

[0067] The refrigerant R receives heat from the airflow AF. Therefore, as the refrigerant R moves through the heat source heat exchanger 13, its temperature rises. In this figure, two types of temperature changes for the refrigerant R are shown.

[0068] The arrow Rn indicates the temperature change in the comparative example. In the comparative example, there is no bridge circuit 40 in the refrigerant circuit, and it is assumed that the refrigerant R moves in the opposite direction to that of the cooling operation. In this case, the refrigerant R moves from position y1 at the rear end 672 of the fin to position y2 at the front end 671 of the fin, similar to the airflow AF.

[0069] The arrow Rc indicates the temperature change in the heat source heat exchanger 13 of this embodiment. The refrigerant circuit has a bridge circuit 40, and counterflow is achieved in the heat source heat exchanger 13, similar to the cooling operation. At this time, the refrigerant R moves in the opposite direction to the airflow AF, from position y2 of the front end 671 of the fin to position y1 of the rear end 672 of the fin.

[0070] In the comparative example indicated by arrow Rn, the temperature difference ΔT3 between the refrigerant R and the airflow AF at position y1 and the temperature difference ΔT4 between the refrigerant R and the airflow AF at position y2 are significantly different. The temperature difference ΔT4 is not large enough. This indicates that heat transfer from the airflow AF to the refrigerant R may be inhibited near the front end 671 of the fin.

[0071] On the other hand, in this embodiment indicated by arrow Rc, the temperature difference ΔT5 between the refrigerant R and the airflow AF at position y1 and the temperature difference ΔT6 between the refrigerant R and the airflow AF at position y2 are both sufficiently large. Therefore, it is understood that heat transfer from the airflow AF to the refrigerant R is carried out without hindrance throughout the entire area of ​​the heat source heat exchanger 13 according to this embodiment.

[0072] When using a refrigerant R that has a large temperature glide, such as a non-azeotropic mixed refrigerant, it tends to be difficult to ensure a sufficient temperature difference between the refrigerant R and the airflow AF at the outlet of the heat exchanger. If a small value such as a temperature difference ΔT4 occurs, the heat exchange performance of the heat source heat exchanger 13 deteriorates. This problem can be improved by installing a bridge circuit 40 to ensure counterflow between the refrigerant R and the airflow AF at all times in the heat source heat exchanger 13.

[0073] (3-4) Circulation rate of refrigerant R The circulation rate of refrigerant R in the refrigeration cycle device 100 varies depending on the operating conditions, increasing or decreasing within a range from the minimum value to the maximum value. In the refrigeration cycle device 100, the circulation rate of refrigerant R may be significantly low. In both cold energy utilization operation and heat energy utilization operation, the minimum value of the circulation rate of refrigerant R in the refrigeration cycle device 100 is less than 35.00 kg / h.

[0074] (4) Detailed structure of the heat source heat exchanger 13. Figure 7 shows the detailed structure of the heat source heat exchanger 13. The height positions of each part are schematically shown in this figure.

[0075] The refrigerant path inlet 62 of the lowest pass 61L is located at a height H1. The refrigerant path inlet 62 of the highest pass 61H is located at a height H2. The average of heights H1 and H2 is the intermediate height H3. In other words, the height difference a between height H2 and intermediate height H3 is equal to the height difference a between intermediate height H3 and height H1. Multiple outlets 54 provided in the flow divider body 51 of the flow divider 50 are located at a height H0.

[0076] The height H0 of all of the multiple outlets 54 is higher than the height H1 of the lowest pass 61L. Furthermore, the height H0 of all of the multiple outlets 54 is higher than the intermediate height H3.

[0077] The upper end of the heat exchanger body 60 is positioned at a height H5. The heights H0 of the multiple outlets 54 are all lower than the height H5.

[0078] The refrigerant path outlet 63 of the highest path 61H is located at a height H7. The heights H0 of all of the multiple outlets 54 are higher than the height H7. Furthermore, the heights H0 of all of the multiple outlets 54 may be set higher than the height H2.

[0079] The refrigerant path outlet 63 of the lowest level path 61L is located at a height H6. The outlet pipe connection part 77 of the merging unit 70 is located at a height H9. Height H9 is lower than height H6.

[0080] The height H0 of each of the multiple outlets 54 is higher than the heights of the first check valve 41, the second check valve 42, the third check valve 43, and the fourth check valve 44 included in the bridge circuit 40.

[0081] (5) Features (5-1) The height H0 of the discharge port 54 is higher than the height of the lowest pass 61L. Therefore, regardless of whether it is a cooling or heating operation, at least some of the refrigerant R moves from top to bottom, so deceleration is less likely to occur and the stagnation of refrigerant R is suppressed. As a result, the occurrence of uneven flow of refrigerant R can be suppressed. Note that the height of the lowest pass 61L referred to here may be the height H1 of the refrigerant pass inlet 62 of the lowest pass 61L.

[0082] (5-2) The height H0 of the outlet 54 is higher than the intermediate height H3. Therefore, deceleration of the refrigerant R is less likely to occur, and thus the occurrence of refrigerant R flow deviation can be suppressed.

[0083] (5-3) The height H0 of the outlet 54 is lower than the height H5 of the upper end of the heat exchanger body 60. Therefore, the heat source heat exchanger 13 can be made compact.

[0084] (5-4) The height H0 of the outlet 54 is higher than the height H7 of the refrigerant path outlet 63 of the highest path 61H. Therefore, since most of the refrigerant R moves from top to bottom, deceleration is less likely to occur, and the occurrence of refrigerant flow deviation can be suppressed.

[0085] (5-5) The height H9 of the outlet pipe connection 77 is lower than the height H6 of the refrigerant path outlet 63 of the lowest pass 61L. Therefore, the refrigerant R that has finished heat exchange is efficiently discharged from the merging unit 70.

[0086] (5-6) The flow of the refrigerant R is rectified by a bridge circuit 40 having check valves 41 to 44. Therefore, the check valves 41 to 44 effectively suppress the backflow of the refrigerant R.

[0087] (5-7) The height H0 of the outlet 54 is higher than the height of any of the check valves 41-44. Therefore, the check valves 41-44 can easily utilize the differential pressure required for opening and closing.

[0088] (5-8) The number of outlets 54 is 4 or more and 8 or less. Therefore, the flow of the refrigerant R can be efficiently divided without excessively increasing the flow resistance experienced by the refrigerant R.

[0089] (6) Modification The refrigeration cycle device 100 according to the above embodiment has one heat source unit 10 and one utilization unit 20. Alternatively, the refrigeration cycle device 100 may have one heat source unit 10 and multiple utilization units 20. Furthermore, the refrigeration cycle device 100 may have multiple heat source units 10.

[0090] <Second Embodiment> (1) Overall Configuration Diagram 8 shows the configuration of the refrigeration cycle device 100A according to the second embodiment. The refrigeration cycle device 100A differs from the refrigeration cycle device 100 according to the first embodiment in that the heat source unit 10 does not have a bridge circuit 40, while the utilization unit 20 has a bridge circuit 80.

[0091] (2) Detailed configuration The refrigeration cycle device 100A has a heat exchanger 23 and a bridge circuit 80.

[0092] (2-1) Utilizing heat exchanger 23 and utilizing fan 24 Unlike the first embodiment, the utilizing heat exchanger 23 and utilizing fan 24 have the same configuration as the heat source heat exchanger 13 and heat source fan 14 in the first embodiment. The utilizing heat exchanger 23 has a refrigerant inlet pipe 23a and a refrigerant outlet pipe 23b. The refrigerant R enters the utilizing heat exchanger 23 through the refrigerant inlet pipe 23a and exits the utilizing heat exchanger 23 through the refrigerant outlet pipe 23b. The utilizing fan 24 promotes heat exchange between air and refrigerant R by generating an airflow AF that passes through the utilizing heat exchanger 23.

[0093] (2-2) Bridge Circuit 80 The bridge circuit 80 ensures that the direction of travel of the refrigerant R in the heat exchanger 23 is always the same. Due to the function of the bridge circuit 80, regardless of whether the direction of travel of the refrigerant R is indicated by arrow CO or arrow HO, the refrigerant R always enters the heat exchanger 23 at the refrigerant inlet pipe 23a and always exits the heat exchanger 23 at the refrigerant outlet pipe 23b.

[0094] The bridge circuit 80 has a first node A', a second node B', a third node C', and a fourth node D'. The first node A' is connected to the refrigerant outlet pipe 23b. The second node B' is connected to the compressor 11 via a four-way switching valve 12. The third node C' is connected to the refrigerant inlet pipe 23a. The fourth node D' is connected to the heat source expansion valve 15.

[0095] Furthermore, the bridge circuit 80 has a first flow path A'B' extending from the first node A' to the second node B', a second flow path B'C' extending from the second node B' to the third node C', a third flow path D'C' extending from the fourth node D' to the third node C', and a fourth flow path A'D' extending from the first node A' to the fourth node D'.

[0096] The bridge circuit 80 includes a first check valve 81, a second check valve 82, a third check valve 83, and a fourth check valve 84. These check valves maintain the same direction of flow of the refrigerant R in the installed flow path and prevent backflow of the refrigerant R. The first check valve 41 is provided in the first flow path A'B' and allows the refrigerant R to flow only in the direction from the first node A' to the second node B'. The second check valve 42 is provided in the second flow path B'C' and allows the refrigerant R to flow only in the direction from the second node B' to the third node C'. The third check valve 43 is provided in the third flow path D'C' and allows the refrigerant R to flow only in the direction from the fourth node D' to the third node C'. The fourth check valve 44 is provided in the fourth flow path A'D' and allows the refrigerant R to flow only in the direction from the first node A' to the fourth node D'.

[0097] (3) Detailed structure of the utilization heat exchanger 23 The utilization heat exchanger 23 in this embodiment has the same configuration as the heat source heat exchanger 13 of the first embodiment shown in Figure 7.

[0098] The refrigerant path inlet 62 of the lowest pass 61L is located at a height H1. The refrigerant path inlet 62 of the highest pass 61H is located at a height H2. The average of heights H1 and H2 is the intermediate height H3. In other words, the height difference a between height H2 and intermediate height H3 is equal to the height difference a between intermediate height H3 and height H1. Multiple outlets 54 provided in the flow divider body 51 of the flow divider 50 are located at a height H0.

[0099] The height H0 of all of the multiple outlets 54 is higher than the height H1 of the lowest pass 61L. Furthermore, the height H0 of all of the multiple outlets 54 is higher than the intermediate height H3.

[0100] The upper end of the heat exchanger body 60 is positioned at a height H5. The heights H0 of the multiple outlets 54 are all lower than the height H5.

[0101] The refrigerant path outlet 63 of the highest path 61H is located at a height H7. The heights H0 of all of the multiple outlets 54 are higher than the height H7. Furthermore, the heights H0 of all of the multiple outlets 54 may be set higher than the height H2.

[0102] The refrigerant path outlet 63 of the lowest level path 61L is located at a height H6. The outlet pipe connection part 77 of the merging unit 70 is located at a height H9. Height H9 is lower than height H6.

[0103] The height H0 of each of the multiple outlets 54 is higher than the heights of the first check valve 81, the second check valve 82, the third check valve 83, and the fourth check valve 84 included in the bridge circuit 80.

[0104] (4) Features In the heat exchanger 23, similar to the heat source heat exchanger 13 of the first embodiment, the refrigerant R moves from top to bottom regardless of whether it is in cooling or heating operation, so deceleration is less likely to occur and stagnation of the refrigerant R is suppressed. As a result, uneven flow of the refrigerant R can be suppressed.

[0105] (5) Modifications Modifications of the first embodiment may also be applied to this embodiment.

[0106] <Third Embodiment> (1) Overall Configuration Diagram 9 shows the configuration of the refrigeration cycle device 100B according to the third embodiment. The refrigeration cycle device 100B differs from the refrigeration cycle device 100 according to the first embodiment and the refrigeration cycle device 100A according to the second embodiment in that the heat source unit 10 and the utilization unit 20 each have a bridge circuit 40 and a bridge circuit 80. The configuration of the bridge circuit 40 and the bridge circuit 80 is the same as in the first or second embodiment.

[0107] (2) Features In both the heat source heat exchanger 13 and the utilization heat exchanger 23, the refrigerant R moves from top to bottom regardless of whether it is in cooling or heating operation, so deceleration is less likely to occur and stagnation of the refrigerant R is suppressed. As a result, uneven flow of the refrigerant R can be suppressed.

[0108] (3) Modifications Modifications of the first or second embodiment may be applied to this embodiment.

[0109] <Conclusion> The embodiments of this disclosure have been described above, but it should be understood that various modifications to the form and details are possible without departing from the purpose and scope of this disclosure as described in the claims.

[0110] 10: Heat source unit 12: Four-way switching valve 13: Heat source heat exchanger (first heat exchanger / second heat exchanger) 13a: Refrigerant inlet pipe 13b: Refrigerant outlet pipe 14: Heat source fan 20: Utilization unit 23: Utilization heat exchanger (second heat exchanger / first heat exchanger) 23a: Refrigerant inlet pipe 23b: Refrigerant outlet pipe 24: Utilization fan 30: Connecting piping group 40, 80: Bridge circuit (refrigerant rectification section) 41, 81: First check valve 42, 82: Second check valve 43, 83: Third check valve 44, 84: Fourth check valve 50: Diverter 51: Diverter body 53: Intake port 54: Outlet port 56: Diverter piping 60: Heat exchanger body 61 : Refrigerant path 61H : Highest path 61L : Lowest path 62 : Refrigerant path inlet 63 : Refrigerant path outlet 70 : Confluencer 75 : Confluencer piping 76 : Confluencer body 77 : Outlet pipe connection 100, 100A, 100B: Refrigeration cycle device H0 : Height of outlet H1 : Height of lowest path inlet H2 : Height of highest path inlet H3 : Intermediate height H5 : Height of top of heat exchanger body H6 : Height of lowest path outlet H7 : Height of highest path outlet H9 : Height of outlet pipe connection AF : Airflow R : Refrigerant

[0111] Japanese Patent Publication No. 2009-222362

Claims

1. A refrigeration cycle device (100) comprising: a four-way switching valve (12) for switching between a first operation and a second operation; a first heat exchanger (13) having a refrigerant inlet pipe (13a) and a refrigerant outlet pipe (13b), which functions as a condenser in the first operation and as an evaporator in the second operation; a second heat exchanger (23) which functions as an evaporator in the first operation and as a condenser in the second operation; and a refrigerant straightening section (40) that causes the refrigerant to flow into the first heat exchanger at the refrigerant inlet pipe and out of the first heat exchanger at the refrigerant outlet pipe in either the first or second operation, wherein the first heat exchanger further comprises: a flow divider (50) for dividing the refrigerant, and a heat exchanger body (60) having a plurality of refrigerant paths (61) through which the refrigerant passes, and the flow divider is A refrigeration cycle device (100) comprising: a flow divider body (51) having one intake port (53) and a plurality of outlet ports (54) connected to the refrigerant inlet pipe; and a plurality of flow divider pipes (56) connecting the plurality of outlet ports to the plurality of refrigerant paths, wherein the plurality of refrigerant paths include a lowest-level path (61L) located at the lowest height (H1) and a highest-level path (61H) located at the highest height (H2), and the height (H0) of all of the plurality of outlet ports is higher than the height (H1) of the lowest-level path.

2. The refrigeration cycle apparatus according to claim 1, wherein the heights (H0) of the plurality of discharge ports are all higher than the intermediate height (H3), which is the average of the heights (H1) of the lowest pass and the height (H2) of the highest pass.

3. The refrigeration cycle apparatus according to claim 1 or claim 2, wherein the height (H0) of each of the plurality of outlets is lower than the height (H5) of the upper end of the heat exchanger body.

4. The refrigeration cycle apparatus according to any one of claims 1 to 3, wherein the heat exchanger body has a plurality of refrigerant path inlets (62) which are points into which the refrigerant flows into the plurality of refrigerant paths, and the height of the lowest path (H1) and the height of the highest path (H2) are the heights of any one of the plurality of refrigerant path inlets (62).

5. The refrigeration cycle apparatus according to any one of claims 1 to 4, wherein the heat exchanger body has a plurality of refrigerant path outlets (63) which are locations where the refrigerant flows out from the plurality of refrigerant paths, and the height (H0) of each of the plurality of outlets is higher than the height (H7) of the highest-level path among the plurality of refrigerant path outlets.

6. The refrigeration cycle apparatus according to any one of claims 1 to 5, wherein the first heat exchanger further comprises a merging device (70) that receives the refrigerant from the heat exchanger body, the refrigerant outlet pipe (13b) is connected to the merging device at an outlet pipe connection (77), and the height (H9) of the outlet pipe connection (77) is lower than the height (H6) of the lowest of the plurality of refrigerant path outlets.

7. The refrigeration cycle apparatus according to any one of claims 1 to 6, wherein the first heat exchanger is a heat source heat exchanger (13) and the second heat exchanger is a utilization heat exchanger (23).

8. The refrigeration cycle apparatus according to any one of claims 1 to 6, wherein the first heat exchanger is a utilization heat exchanger (23) and the second heat exchanger is a heat source heat exchanger (13).

9. The refrigeration cycle apparatus according to any one of claims 1 to 8, wherein the refrigerant rectifier is a bridge circuit (40) having a plurality of check valves (41 to 44).

10. The refrigeration cycle apparatus according to claim 9, wherein the heights (H0) of the plurality of outlets are all higher than the heights of the plurality of check valves.

11. The refrigeration cycle apparatus according to any one of claims 1 to 10, wherein the number of the plurality of outlets is four or more and eight or less.

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