Heat exchange unit and air conditioning device

Abstract

In an indoor unit (7), a cross-flow fan (70) is disposed at a position corresponding to an air inlet (52) inside a casing (50). The air inlet has a first region (A1) overlapping the cross-flow fan in a front view, and a second region (A2) positioned on the side of the first region where a tongue part (63) is provided in the casing. Among a plurality of guide plates provided to the air inlet, a first guide plate (92a) located closest to the center of the cross-flow fan in the first region is provided in an orientation extending upward toward the cross-flow fan, and a second guide plate (92b) positioned in the second region is provided in an orientation extending downward toward the cross-flow fan.

Description

Heat exchange unit and air conditioning device

[0001] The present disclosure relates to a heat exchange unit and an air conditioner.

[0002] Patent Document 1 discloses a heat exchange unit including a crossflow fan and a heat exchanger. The crossflow fan and the heat exchanger are housed in a casing. An air inlet is formed in the lower front surface of the casing, and an air outlet is formed in the upper surface of the casing. An air passage extending from the air inlet to the air outlet is provided inside the casing. The crossflow fan is disposed at a position corresponding to the air inlet of the air passage. The heat exchanger is disposed downstream of the crossflow fan in the air passage.

[0003] Japanese Utility Model Application Laid-Open Publication No. 3-127137

[0004] In the heat exchange unit described above, a plurality of guide plates are provided at the air inlet at intervals in the vertical direction to guide the air drawn into the air passage by the operation of the crossflow fan. In this heat exchange unit, the crossflow fan is provided near the air inlet, and the guide plates closest to the crossflow fan are oriented to guide the air in the direction opposite to the rotation direction of the crossflow fan, thereby imparting a pre-swirl to the flow of air drawn into the crossflow fan and increasing the pressure of the crossflow fan.

[0005] In addition, in the heat exchange unit, the vertical width of the air inlet is made larger than the diameter of the crossflow fan, thereby ensuring the flow rate of air drawn into the air passage. The operation of the crossflow fan then allows air to circulate efficiently through the air passage. In this case, the multiple guide plates are arranged to cover the entire opening surface of the air inlet. Therefore, the guide plates are also provided in positions that do not overlap with the crossflow fan in a front view. A configuration in which all guide plates are arranged in a uniform direction that generates pre-swirl at the air inlet presents the following unique problems.

[0006] 15 , when the suction opening (52a) is formed larger than the diameter of the cross-flow fan (70), if the guide plates (92) are oriented in the same direction, the air guided by the guide plates (92) located near the upper edge of the suction opening (52a) and not overlapping with the cross-flow fan (70) in front view on the side of the tongue portion (63) constituting the wall surface of the air passage (56) provided along part of the outer periphery of the cross-flow fan (70) flows radially outward from the cross-flow fan (70) and is then sucked into the cross-flow fan (70). Therefore, the air guided by the guide plates (92) located near the upper edge of the suction opening (52a) has to travel a longer path to reach the cross-flow fan (70), resulting in loss of power in the cross-flow fan (70).

[0007] An object of the present disclosure is to reduce losses in a crossflow fan in a heat exchange unit in which pre-swirl is generated by a guide plate provided at the intake port.

[0008] A first aspect of the present disclosure is directed to a heat exchange unit (7). The heat exchange unit (7) includes a casing (50) having an air inlet (52), an outlet (54), and an air passage (56) that connects the air inlet (52) and the outlet (54), a cross-flow fan (70) housed in the air passage (56), and a heat exchanger (80) arranged in the air passage (56) downstream of the cross-flow fan (70). The cross-flow fan (70) is arranged at a position corresponding to the air inlet (52) in a first direction perpendicular to an opening plane of the air inlet (52), and rotates around a rotation axis (Ra) extending along a second direction perpendicular to the first direction. The casing (50) has a tongue portion (63) that forms a wall surface of the air passage (56) and is provided along a portion of the outer periphery of the crossflow fan (70) on one side of the crossflow fan (70) in a third direction perpendicular to the first and second directions. The suction opening (52) has a first region (A1) that overlaps with the crossflow fan (70) when viewed in the first direction, and a second region (A2) that is located on the tongue portion (63) side of the first region (A1) in the third direction. The suction opening (52) is provided with a plurality of guide plates (92), each extending in the second direction and spaced apart from one another in the third direction. The plurality of guide plates (92) includes a first guide plate (92a) that is located closest to a center (C1) of the crossflow fan (70) in the first region (A1) and a second guide plate (92b) that is located in the second region (A2).In a cross section perpendicular to the second direction, a line passing through a center (C2) of the guide plate (92) and a center (C1) of the cross flow fan (70) is defined as a first line (L1), a line passing through an upstream end of the guide plate (92) located on the upstream side in the air flow direction and a downstream end of the guide plate (92) located on the downstream side is defined as a second line (L2), and a point of intersection between an outer peripheral surface (70a) of the cross flow fan (70) and the first line (L1) is a point of intersection of the suction port ( If a point of intersection between the outer peripheral surface (70a) of the cross flow fan (70) and the second straight line (L2) that is closest to the inlet (52) is defined as a first intersection (P1), and a point of intersection between the outer peripheral surface (70a) of the cross flow fan (70) and the second straight line (L2) that is closest to the inlet (52) is defined as a second intersection (P2), the first guide plate (92a) is provided in an orientation inclined with respect to the first direction such that the second intersection (P2) is located on the rear side of the first intersection (P1) in the rotation direction of the cross flow fan (70). The second guide plate (92b) is provided in an orientation such that a second inclination angle that the second straight line (L2) of the second guide plate (92b) makes with respect to the first direction is smaller than the first inclination angle that the second straight line (L2) of the first guide plate (92a) makes with respect to the first direction, or such that the second inclination angle is on a side opposite to a side on which the first guide plate (92a) makes the first inclination angle with respect to the first direction.

[0009] In the first aspect, the suction port (52) has a first region (A1) corresponding to the cross flow fan (70) as viewed in the first direction, and a second region (A2) located on the tongue portion (63) side of the first region (A1) in the third direction. Of the plurality of guide plates (92) provided at the suction port (52), a first guide plate (92a) located closest to the center (C1) of the cross flow fan (70) in the first region (A1) is provided at an angle with respect to the first direction. The first guide plate (92a) is oriented such that, in a cross section perpendicular to the second direction, a second intersection (P2) of the outer peripheral surface (70a) of the cross flow fan (70) and the second straight line (L2), which is closest to the inlet (52), is located rearward in the rotation direction of the cross flow fan (70) of a first intersection (P1) of the outer peripheral surface of the cross flow fan (70) and the first straight line (L1), which is closest to the inlet (52). The first guide plate (92a) imparts a pre-swirl to the flow of air sucked into the cross flow fan (70) in the direction opposite to the rotation direction of the cross flow fan (70), thereby increasing the pressure in the cross flow fan (70). Furthermore, a second guide plate (92b) of the plurality of guide plates (92) located in the second region (A2) is oriented differently from the first guide plate (92a). The second guide plate (92b) is oriented such that the second inclination angle formed by the second straight line (L2) of the second guide plate (92b) with respect to the first direction is smaller than the first inclination angle formed by the second straight line (L2) of the first guide plate (92a) with respect to the first direction, or the second inclination angle is formed on the side opposite to the side on which the first guide plate (92a) forms the first inclination angle with respect to the first direction. This allows air that is guided by the second guide plate (92b) and sucked into the air passage (56) when passing through the suction port (52) to flow more smoothly into the crossflow fan (70), compared to when the second guide plate (92b) assumes the same orientation as the first guide plate (92a). This reduces loss in the crossflow fan (70).

[0010] A second aspect of the present disclosure is the heat exchange unit (7) of the first aspect, wherein the plurality of guide plates (92) includes a third guide plate (92c) located between the first guide plate (92a) and the second guide plate (92b) in the first region (A1). The third guide plate (92c) is oriented such that a third inclination angle formed by the second straight line (L2) of the third guide plate (92c) with respect to the first direction is between the first inclination angle and the second inclination angle.

[0011] In the second aspect, a third guide plate (92c) of the multiple guide plates (92), which is located between the first guide plate (92a) and the second guide plate (92b), is oriented differently from the first guide plate (92a) and the second guide plate (92b). The orientation of the third guide plate (92c) is such that the third inclination angle formed by the second straight line (L2) of the third guide plate (92c) with respect to the first direction is between the first inclination angle and the second inclination angle. The third guide plate (92c) can prevent the orientation of the multiple guide plates (92) from changing significantly between the first guide plate (92a) and the second guide plate (92b). This can mitigate collision of air flows guided by adjacent guide plates (92) when passing through the suction opening (52). This is advantageous for reducing loss in the crossflow fan (70).

[0012] A third aspect of the present disclosure is the heat exchange unit (7) of the first or second aspect, wherein the air passage (56) includes an intake space (56a) provided between the intake port (52) and the cross-flow fan (70). The intake space (56a) corresponds to the second region (A2) in the first direction and expands to correspond to a portion of the cross-flow fan (70) on the intake port (52) side in the third direction.

[0013] In the third aspect, the suction space (56a) in the casing (50) corresponds to the second region (A2) in the first direction and expands to correspond to the portion of the cross-flow fan (70) on the suction port (52) side in the third direction. Including such a suction space (56a) in the air passage (56) ensures a large opening area of ​​the suction port (52). However, when the second guide plate (92b) assumes the same position as the first guide plate (92a), the air passing through the suction port (52) is guided by the second guide plate (92b) radially outward from the cross-flow fan (70), which tends to increase loss in the cross-flow fan (70). Therefore, the technology of the present disclosure is particularly effective for the heat exchange unit (7).

[0014] A fourth aspect of the present disclosure is the heat exchange unit (7) of any one of the first to third aspects, wherein the third direction corresponds to the up-down direction. The cross-flow fan (70) rotates such that the blades (76) of the cross-flow fan (70) move from the upper side to the lower side on the inlet (52) side. The first guide plate (92a) is inclined with respect to the first direction so that the second straight line (L2) extends upward toward the cross-flow fan (70). The second guide plate (92b) is located above the first guide plate (92a) and is inclined with respect to the first direction so that the second straight line (L2) extends downward toward the cross-flow fan (70), or the second straight line (L2) is parallel to the first direction.

[0015] A fifth aspect of the present disclosure is the heat exchange unit (7) of any one of the first to fourth aspects, wherein the first inclination angle θ1 satisfies 0°≦θ1≦60°.

[0016] In the fifth aspect, the first inclination angle θ1 formed by the second straight line (L2) of the first guide plate (92a) with respect to the first direction is not less than 0° and not more than 60°. When the first inclination angle θ1 is not more than 60°, it is possible to prevent the resistance (ventilation resistance) of the air passing through the suction opening from becoming excessive, and to suitably impart a pre-swirl to the flow of air sucked into the cross flow fan (70).

[0017] A sixth aspect of the present disclosure is the heat exchange unit (7) of any one of the first to fifth aspects, wherein the second guide plate (92b) is disposed at a second inclination angle θ2 on an opposite side to the first guide plate (92a) at the first inclination angle with respect to the first direction, and the second inclination angle θ2 satisfies 0°≦θ2≦45°.

[0018] In the sixth aspect, the second guide plate (92b) is inclined with respect to the first direction toward the opposite side to the first guide plate (92a), and a second inclination angle θ2 formed by a second straight line (L2) of the second guide plate (92b) with respect to the first direction is greater than or equal to 0° and less than or equal to 45°. When the second inclination angle θ2 is 45° or less, the air passing through the inlet (52) can be guided toward the crossflow fan (70) by the second guide plate (92b) while preventing excessive resistance (ventilation resistance) when the air passes through the inlet (52).

[0019] A seventh aspect of the present disclosure is the heat exchange unit (7) of any one of the first to sixth aspects, wherein the plurality of guide plates (92) includes a plurality of fourth guide plates (92d) arranged on the opposite side of the first guide plate (92a) from the second guide plate (92b). Each of the plurality of fourth guide plates (92d) is oriented such that a fourth inclination angle formed by the second straight line (L2) of the fourth guide plate (92d) with respect to the first direction is larger than the first inclination angle. The fourth inclination angle increases as the fourth guide plate (92d) forming the fourth inclination angle becomes farther away from the first guide plate (92a).

[0020] In the seventh aspect, each fourth guide plate (92d) among the plurality of guide plates (92) is oriented such that the fourth inclination angle formed by the second straight line (L2) with respect to the first direction is greater than the first inclination angle. The fourth guide plate (92d) is a guide plate (92) disposed on the opposite side of the first guide plate (92a) from the second guide plate (92b), and the fourth inclination angle increases with increasing distance from the first guide plate (92a). The fourth guide plate (92d) prevents the orientation of the plurality of guide plates (92) from significantly changing on the side opposite the second guide plate (92b) from the first guide plate (92a). This reduces collision between air flows guided by adjacent guide plates (92) when passing through the suction opening (52). This is advantageous for reducing losses in the crossflow fan (70).

[0021] An eighth aspect of the present disclosure is directed to an air conditioner (1). The air conditioner (1) includes the heat exchange unit (7) according to any one of the first to seventh aspects.

[0022] In the eighth aspect, the air conditioner (1) includes a heat exchange unit (7). The heat exchange unit (7) can reduce the loss of the cross flow fan (70). Therefore, the energy saving performance of the air conditioner (1) can be improved.

[0023] FIG. 1 is a schematic diagram of an air conditioning apparatus according to an embodiment. FIG. 2 is a schematic front view of an indoor unit. FIG. 3 is a cross-sectional view of the indoor unit taken along line III-III in FIG. 2. FIG. 4 is a perspective view of a fan rotor of a crossflow fan. FIG. 5 is a front view of the main parts of the indoor unit enclosed by V in FIG. 2. FIG. 6 is a cross-sectional view of the main parts of the indoor unit enclosed by VI in FIG. 3. FIG. 7 is a cross-sectional view illustrating the main parts of the indoor unit of Comparative Example 1. FIG. 8 is a cross-sectional view illustrating the main parts of the indoor unit of Comparative Example 2. FIG. 9 is a cross-sectional view illustrating the main parts of the indoor unit of Comparative Example 3. FIG. 10 is a table showing the specifications of the guide plates and the rotation speeds at the same air volume for the examples and Comparative Examples 1 to 3. FIG. 11 is a cross-sectional view illustrating the air flow in the main parts of the indoor unit. FIG. 12 is a cross-sectional view of the main parts of the indoor unit of a first modified example, corresponding to FIG. 6. FIG. 13 is a cross-sectional view of the main parts of the indoor unit of a second modified example, corresponding to FIG. 6. FIG. 14 is a cross-sectional view of the main parts of the indoor unit of another embodiment, corresponding to FIG. 6. FIG. 15 is a cross-sectional view illustrating an example of the air flow in the main part of the indoor unit when all the guide plates are inclined upward toward the rear side relative to the horizontal direction.

[0024] Exemplary embodiments will be described in detail below with reference to the drawings. In the following embodiments, a case where a heat exchange unit according to the present disclosure is applied to an air conditioner will be described as an example. Note that the drawings are intended to conceptually explain the technology of the present disclosure. Therefore, in the drawings, dimensions, ratios, or numbers may be exaggerated or simplified to facilitate understanding of the technology of the present disclosure.

[0025] -Configuration of Air Conditioner- The heat exchange unit of this embodiment is used in an air conditioner (1). The air conditioner (1) is configured as a heat pump type cooling / heating / hot water supply system. As shown in FIG. 1, the air conditioner (1) includes an outdoor unit (3), a hot water supply unit (5), and an indoor unit (7). The indoor unit (7) is an example of a heat exchange unit. The outdoor unit (3) is installed outdoors. The hot water supply unit (5) and the indoor unit (7) are each installed indoors.

[0026] <Outdoor Unit> The outdoor unit (3) heats or cools water and supplies the heated or cooled water to the hot water supply unit (5) and the indoor unit (7). The outdoor unit (3) includes a refrigerant circuit (10) and an outdoor fan (12). The outdoor unit (3) further includes a casing (not shown). The casing accommodates the entire refrigerant circuit (10), which is a closed circuit. The casing accommodates components of the refrigerant circuit (10), such as a compressor (14), an outdoor heat exchanger (16), an expansion valve (18), and a water heat exchanger (20), as well as the outdoor fan (12).

[0027] The refrigerant circuit (10) performs a refrigeration cycle. The refrigerant circuit (10) is filled with a refrigerant. The refrigerant in the refrigerant circuit (10) is, for example, a hydrofluorocarbon (HFC) refrigerant, a hydrofluoroolefin (HFO) refrigerant, a mixed refrigerant of an HFC refrigerant and an HFO refrigerant, a trifluoroiodomethane (CF3I) refrigerant, a carbon dioxide refrigerant, a hydrocarbon refrigerant, or a natural refrigerant such as propane (R290) or ammonia (R717).

[0028] The refrigerant circuit (10) includes, as its main components, a compressor (14), an outdoor heat exchanger (16), an expansion valve (18), and a water heat exchanger (20). The refrigerant circuit (10) further includes a four-way selector valve (22) and an accumulator (24). The compressor (14) and the four-way selector valve (22), the four-way selector valve (22) and the water heat exchanger (20), the water heat exchanger (20) and the expansion valve (18), the expansion valve (18) and the outdoor heat exchanger (16), the outdoor heat exchanger (16) and the four-way selector valve (22), the four-way selector valve (22) and the accumulator (24), and the accumulator (24) and the compressor (14) are connected to each other by refrigerant piping (26).

[0029] The compressor (14) compresses the refrigerant. The compressor (14) is configured to have a variable capacity under inverter control. The accumulator (24) stores the liquid refrigerant sucked into the compressor (14). The outdoor heat exchanger (16) exchanges heat between the refrigerant flowing therethrough and outdoor air. The refrigerant of the refrigerant circuit (10) flows through the outdoor heat exchanger (16). The outdoor fan (12) generates an air flow and transports the air to be passed through the outdoor heat exchanger (16). For example, the outdoor fan (12) is configured as a propeller fan. The expansion valve (18) reduces the pressure of the refrigerant. The water heat exchanger (20) exchanges heat between the refrigerant of the refrigerant circuit (10) and water of the water circuit (30).

[0030] The four-way switching valve (22) switches the circulation direction of the refrigerant in the refrigerant circuit (10). The four-way switching valve (22) has a first port (22a), a second port (22b), a third port (22c), and a fourth port (22d). The first port (22a) is connected to the discharge side of the compressor (14). The second port (22b) is connected to the outdoor heat exchanger (16). The third port (22c) is connected to the water heat exchanger (20). The fourth port (22d) is connected to the suction side of the compressor (14) via the accumulator (24). The four-way switching valve (22) is switched between a first state (shown by the solid line in FIG. 1 ) and a second state (shown by the dashed line in FIG. 1 ).

[0031] The first state of the four-way selector valve (22) is a state in which the first port (22a) and the third port (22c) are communicated with each other and the second port (22b) and the fourth port (22d) are communicated with each other. The second state of the four-way selector valve (22) is a state in which the first port (22a) and the second port (22b) are communicated with each other and the third port (22c) and the fourth port (22d) are communicated with each other. When the four-way selector valve (22) is in the first state, the refrigerant in the refrigerant circuit (10) flows in the direction of the solid arrows in Figure 1, so that the outdoor heat exchanger (16) functions as an evaporator and the water heat exchanger (20) functions as a radiator. When the four-way switching valve (22) is in the second state, the refrigerant in the refrigerant circuit (10) flows in the direction of the dashed arrow in Figure 1, the outdoor heat exchanger (16) functions as a radiator, and the water heat exchanger (20) functions as an evaporator.

[0032] <Hot Water Supply Unit> The hot water supply unit (5) stores water heated by the outdoor unit (3). The hot water supply unit (5) includes a water circuit (30). The water circuit (30) is connected to a water heat exchanger (20) and an indoor heat exchanger (80). The water circuit (30) includes the water heat exchanger (20), a pump (32), a three-way valve (34), a first check valve (36), a second check valve (38), a water storage tank (40), and the indoor heat exchanger (80). The water heat exchanger (20) and the three-way valve (34), the three-way valve (34) and the water storage tank (40), the water storage tank (40) and the pump (32), the pump (32) and the water heat exchanger (20), the three-way valve (34) and the indoor heat exchanger (80), and the indoor heat exchanger (80) and the water storage tank (40) are connected by water piping (42).

[0033] The water storage tank (40) is a container for storing water. The water storage tank (40) has a heat storage member (not shown). The heat storage member is fixed inside the water storage tank (40) and is located in the water stored in the water storage tank (40). The water storage tank (40) is provided with a hot water heat transfer pipe (44). A water supply source such as a tap water supply is connected to an inlet of the hot water heat transfer pipe (44) via a water supply pipe (46). A hot water heater is connected to an outlet of the hot water heat transfer pipe (44) via a hot water supply pipe (48).

[0034] A hot water heater is a faucet or shower tap that can supply hot water in a building. Water sent from a water supply source to a water storage tank (40) via a water supply pipe (46) is sent to the hot water heater through a hot water heat transfer pipe (44) and a hot water supply pipe (48). At this time, the water passing through the hot water heat transfer pipe (44) exchanges heat with the high-temperature hot water and heat storage material in the water storage tank (40) and becomes hot water at a temperature of about 40°C to 50°C. In the hot water heater, the temperature of the hot water is adjusted using a mixer faucet or the like.

[0035] The pump (32) delivers the sucked water to the water heat exchanger (20) to circulate the water in the water circuit (30). The first check valve (36) and the second check valve (38) are provided in a water pipe (42) connecting the water storage tank (40) and the indoor heat exchanger (80). The water pipe (42) connecting the water storage tank (40) and the indoor heat exchanger (80) forms a branch pipe (43) to which three water pipes (42) are joined. The suction side of the pump (32) is connected to a portion of the branch pipe (43) between the first check valve (36) and the second check valve (38).

[0036] The first check valve (36) is located on the indoor heat exchanger (80) side of the branching position of the branch pipe (43). The second check valve (38) is located on the water storage tank (40) side of the branching position of the branch pipe (43). The first check valve (36) allows water to flow from the indoor heat exchanger (80) side of the branch pipe (43) to the pump (32) and prevents water from flowing in the reverse direction. The second check valve (38) allows water to flow from the water storage tank (40) to the pump (32) of the branch pipe (43) and prevents water from flowing in the reverse direction. The three-way valve (34) switches the water circulation path in the water circuit (30). The three-way valve (34) switches between a first state and a second state.

[0037] The first state of the three-way valve (34) allows water to flow between the water heat exchanger (20) and the indoor heat exchanger (80). The second state of the three-way valve (34) allows water to flow between the water heat exchanger (20) and the water storage tank (40). When the three-way valve (34) is in the first state, water discharged from the pump (32) flows through the three-way valve (34), the indoor heat exchanger (80), and the first check valve (36) in this order, as shown by the solid lines in Fig. 1, and is then drawn into the pump (32) again. When the three-way valve (34) is in the second state, water discharged from the pump (32) flows through the three-way valve (34), the water storage tank (40), and the second check valve (38) in this order, as shown by the dashed lines in Fig. 1, and is then drawn into the pump (32) again.

[0038] <Indoor Unit> The indoor unit (7) cools or heats an indoor space by utilizing the heat of water supplied by the water circuit (30). The indoor unit (7) is a fan coil unit. The indoor unit (7) includes a cross-flow fan (70) as an indoor fan and an indoor heat exchanger (80). The indoor unit (7) further includes a casing (50) (not shown in FIG. 1 ). The cross-flow fan (70) and the indoor heat exchanger (80) are housed in the casing (50).

[0039] The indoor heat exchanger (80) exchanges heat between water flowing therethrough and indoor air. Water from the water circuit (30) flows inside the indoor heat exchanger (80). The cross-flow fan (70) generates an air flow and transports the air to be passed through the indoor heat exchanger (80). When low-temperature water cooled by the water heat exchanger (20) is sent to the indoor heat exchanger (80), the air transported by the cross-flow fan (70) is cooled by the indoor heat exchanger (80). When high-temperature water heated by the water heat exchanger (20) is sent to the indoor heat exchanger (80), the air transported by the cross-flow fan (70) is heated by the indoor heat exchanger (80).

[0040] - Operation of the Air Conditioner - The air conditioner (1) performs cooling operation and heating operation.

[0041] <Cooling Operation> The cooling operation is an operation for cooling the air in the indoor space. In the cooling operation, the four-way selector valve (22) is set to the first state, the three-way valve (34) is set to the first state, and the compressor (14), the outdoor fan (12), the pump (32), and the cross-flow fan (70) are operated. During the cooling operation, the water flowing through the water circuit (30) is cooled in the water heat exchanger (20) and sent to the indoor heat exchanger (80). The air transported by the cross-flow fan (70) is cooled as it passes through the indoor heat exchanger (80) and is supplied to the indoor space.

[0042] <Heating Operation> The heating operation is an operation for heating the air in the indoor space. In the heating operation, the four-way selector valve (22) is set to the second state, the three-way valve (34) is set to the first state, and the compressor (14), the outdoor fan (12), the pump (32), and the cross-flow fan (70) are operated. During the heating operation, the water flowing through the water circuit (30) is heated in the water heat exchanger (20) and sent to the indoor heat exchanger (80). The air transported by the cross-flow fan (70) is heated as it passes through the indoor heat exchanger (80) and is supplied to the indoor space.

[0043] -Detailed Configuration of Indoor Unit- The configuration of the indoor unit (7) will be described in detail with reference to Figures 2 to 6. In the following description, the terms "upper," "lower," "left," "right," "front," and "rear" refer to the directions indicated by the arrows in Figures 2, 3, 5, and 6. The front-to-rear direction corresponds to the first direction. The left-to-right direction corresponds to the second direction. The up-down direction corresponds to the third direction.

[0044] The indoor unit (7) shown in Fig. 2 is configured as a wall-mounted unit. The indoor unit (7) is installed at the bottom of a wall inside a room. As shown in Fig. 3, the indoor unit (7) includes a casing (50), a cross-flow fan (70), an indoor heat exchanger (80), an air filter (82), and a fan guard (84). In this specification, the "outer peripheral surface (70a) of the cross-flow fan (70)" refers to the cylindrical surface defined by the rotation locus of the radially outer ends of the blades (76) of the cross-flow fan (70).

[0045] <Casing> The casing (50) is formed in the shape of a hollow box. Specifically, the casing (50) has a rectangular parallelepiped shape with its longitudinal direction in the left-right direction and its lateral direction in the front-rear direction, and is relatively thin in the front-rear direction. The casing (50) houses the crossflow fan (70), the indoor heat exchanger (80), the air filter (82), and the fan guard (84). The casing (50) is formed by combining metal plate materials or resin plate materials.

[0046] The casing (50) has a top plate (50a), a bottom plate (50b), a left plate (50c), a right plate (50d), a front plate (50e), and a rear plate (50f). The top plate (50a) and the bottom plate (50b), the left plate (50c) and the right plate (50d), and the front plate (50e) and the rear plate (50f) face each other. The top plate (50a) constitutes the upper surface of the casing (50). The bottom plate (50b) constitutes the lower surface of the casing (50). The left plate (50c) constitutes the right surface of the casing (50). The left plate (50c) constitutes the left surface of the casing (50). The front plate (50e) constitutes the front surface of the casing (50). The rear plate (50f) constitutes the rear surface of the casing (50).

[0047] The casing (50) is formed with an inlet (52), an outlet (54), and an air passage (56). The inlet (52) is an opening for drawing air from the indoor space. The inlet (52) includes a first inlet (52a) and a second inlet (52b). The first inlet (52a) is formed in the lower front part of the casing (50), i.e., the lower part of the front plate (50e), in the shape of a horizontally long rectangle. The width of the first inlet (52a) in the left-right direction is wider than the width of the first inlet (52a) in the up-down direction. The direction perpendicular to the opening plane of the first inlet (52a) corresponds to the front-rear direction.

[0048] The first suction port (52a) is provided with a suction grill (90). The suction grill (90) has a plurality of guide plates (92). The plurality of guide plates (92) may be attached to a frame fitted into the first suction port (52a), or may be attached directly to the periphery of the first suction port (52a). The second suction port (52b) is formed in the front part of the lower surface of the casing (50), i.e., the front part of the bottom plate (50b), in the shape of a horizontally long rectangle. The width of the second suction port (52b) in the left-right direction is wider than the width of the second suction port (52b) in the front-rear direction.

[0049] The air outlet (54) is an opening for blowing the air after heat exchange into the indoor space. The air outlet (54) is formed in a horizontally long rectangular shape on the upper surface of the casing (50), i.e., the top plate (50a). The width of the air outlet (54) in the left-right direction is wider than the width of the air outlet (54) in the front-rear direction. The air outlet (54) is provided with a plurality of flaps (55). The plurality of flaps (55) each extend in the left-right direction and are arranged at intervals from one another in the front-rear direction. The flaps (55) are airflow direction adjusting plates that change the direction of the air blown out of the air outlet (54), and are attached to the casing (50) to be rotatable about an axis extending in the left-right direction.

[0050] The air passage (56) is a passage that connects the suction port (52) and the discharge port (54) and is provided inside the casing (50). A passage forming portion (60) is provided inside the casing (50). The passage forming portion (60) forms a part of the air passage (56) on the suction port (52) side into a scroll shape and accommodates a crossflow fan (70). The air passage (56) formed by the passage forming portion (60) is open forward and downward at its lower portion and extends forward from the scroll-shaped portion toward the upper side. The passage forming portion (60) includes a stabilizer (62) and a rear guider (64). The stabilizer (62) and the rear guider (64) are each a metal part or a resin molded part.

[0051] The stabilizer (62) is attached to the front plate (50e) and disposed above the cross flow fan (70). The stabilizer (62) divides the air passage (56) formed by the passage forming portion (60) into an intake space (56a) and a discharge space (56b). The intake space (56a) is a space through which air is drawn into the cross flow fan (70) from the intake port (52) and is provided between the intake port (52) and the cross flow fan (70). The discharge space (56b) is a space through which air is discharged from the cross flow fan (70) toward the discharge port (54) and is provided downstream of the cross flow fan (70).

[0052] The stabilizer (62) constitutes the front wall surface of the air passage (56). The stabilizer (62) has a tongue portion (63). The tongue portion (63) is formed on a lower rear portion of the stabilizer (62) and protrudes obliquely downward rearward from the front portion of the lower surface of the stabilizer (62). The tongue portion (63) corresponds to an upper portion of the rotation axis (Ra) of the cross-flow fan (70). The tongue portion (63) is provided on one side of the cross-flow fan (70) in the up-down direction, i.e., on the upper side in this example, along a part of the outer periphery of the cross-flow fan (70), and extends in the left-right direction so as to correspond to the entire length of the cross-flow fan (70).

[0053] The tongue portion (63) is located near the outer peripheral surface (70a) of the cross-flow fan (70) and faces the outer peripheral surface (70a) with a gap therebetween. The tongue portion (63) constitutes the portion of the stabilizer (62) closest to the cross-flow fan (70). The tongue portion (63) constitutes the inner wall surface of the scroll-shaped portion of the air passage (56) formed by the passage forming portion (60). An intake space (56a) is also provided in front of the tongue portion (63). The intake space (56a) corresponds in the front-rear direction to a second region (A2) (described later) of the intake port (52), and extends in the up-down direction to correspond to the portion of the cross-flow fan (70) on the intake port (52) side.

[0054] The rear guider (64) is attached to the rear plate (50f) and the bottom plate (50b) and is disposed rearward of the cross-flow fan (70). Strictly speaking, the rear guider (64) is disposed between the cross-flow fan (70) and the rear plate (50f) and between the cross-flow fan (70) and the bottom plate (50b). The rear guider (64) forms the lower wall surface and the rear wall surface of the air passage (56). The rear guider (64) extends along the outer periphery of the cross-flow fan (70). The rear guider (64) has a curved portion that is closest to the outer periphery surface (70a) of the cross-flow fan (70) at its lower portion and gradually moves away from the outer periphery surface of the cross-flow fan (70) as it extends upward.

[0055] The rear guider (64) constitutes a water receiving portion (65). The water receiving portion (65) is provided at the upper end of the rear guider (64) and is positioned so as to cover the lower end of the indoor heat exchanger (80) from below. The water receiving portion (65) is a drain pan that receives water and receives condensed water generated in the air inside the casing (50) at or near the indoor heat exchanger (80). The indoor unit (7) is provided with a drainage mechanism (not shown) that discharges water from the water receiving portion to the outside of the room. The drainage mechanism may be, for example, a drain pump, a drain pipe, or the like.

[0056] <Cross-flow fan> The cross-flow fan (70) is housed in the air passage (56). The cross-flow fan (70) has a rotation axis (Ra) oriented in the left-right direction and is disposed in the lower part of the air passage (56) formed by the passage forming portion (60). Specifically, the cross-flow fan (70) is disposed behind the suction grill (90) so as to correspond to the first suction port (52a) in the front-rear direction. The outer peripheral surface (70a) of the cross-flow fan (70) is located near the suction grill (90). The shortest distance between the outer peripheral surface (70a) of the cross-flow fan (70) and the suction grill (90) is not less than 5 mm and not more than 30 mm.

[0057] The crossflow fan (70) rotates around a rotation axis (Ra) extending in the left-right direction. The crossflow fan (70) of this example rotates such that the blades (76) of the crossflow fan (70) rotate from top to bottom on the inlet (52) side and rotate from bottom to top on the discharge side (see FIG. 7 ). The crossflow fan (70) includes a fan rotor (72) shown in FIG. 4 and a motor (not shown). The fan rotor (72) includes a plurality of partition plates (74), a plurality of blades (76), and two shafts (78).

[0058] The partition plates (74) are each formed in a disk shape and are spaced apart in the left-right direction so that their centers are aligned on the same straight line. A line connecting the centers of the partition plates (74) coincides with the rotation axis (Ra) of the fan rotor (72). The two shafts (78) are formed so as to protrude outward in the left-right direction from the centers of the partition plates (74) located at both ends of the fan rotor (72). One of the shafts (78) is rotatably supported by the left plate (50c) or the right plate (50d) of the casing (50) or a support shaft member fixed to the casing (50). The other shaft (78) is connected to a motor.

[0059] The plurality of blades (76) are provided between the plurality of partition plates (74) and span the outer peripheries of pairs of opposing partition plates (74). The numerous blades (76) are arranged at intervals from one another in the circumferential direction of the fan rotor (72). Each blade (76) is curved so as to bulge in the circumferential direction of the fan rotor (72) in the opposite direction to the rotation direction (the direction indicated by the arrow in FIG. 4 ), and is arranged in an inclined position with respect to the radial direction of the fan rotor (72) so that the more inward the blade in the radial direction of the fan rotor (72), the more it is positioned in the opposite direction to the rotation direction in the circumferential direction of the fan rotor (72).

[0060] <Indoor Heat Exchanger> As shown in FIG. 3 , the indoor heat exchanger (80) is disposed downstream of the crossflow fan (70) in the air passage (56). The indoor heat exchanger (80) is, for example, a fin-and-tube heat exchanger. The indoor heat exchanger (80) is fixed to the casing (50) and the passage-forming portion (60) so that substantially all of the air flowing through the air passage (56) passes through the indoor heat exchanger (80). In this example, the indoor heat exchanger (80) is disposed above the passage-forming portion (60) in a forward-tilted inclined position so as to protrude upward and forward. A lower portion of the indoor heat exchanger (80) is located at the rear side of the casing (50) and is supported by the water receiving portion (65). An upper portion of the indoor heat exchanger (80) is supported by the front plate (50e) of the casing (50).

[0061] <Air Filter> The air filter (82) is disposed in the air passage (56) upstream of the cross flow fan (70) and in the vicinity of the suction port (52). The air filter (82) is attached to the casing (50) or the passage forming portion (60) so that substantially all of the air drawn into the cross flow fan (70) passes through the air filter (82). The air filter (82) is located between the first suction port (52a) and the cross flow fan (70) and between the second suction port (52b) and the cross flow fan (70). The air filter (82) is provided on the rear side of the suction grille (90).

[0062] The air filter (82) and the passage forming portion (60) enclose the crossflow fan (70). In this example, the air filter (82) is formed in an L-shape so as to be continuous with the first suction inlet (52a) and the second suction inlet (52b). The air filter (82) may be provided separately for the first suction inlet (52a) and the second suction inlet (52b). The air filter (82) captures dust in the air sucked into the air passage (56) through the suction inlet (52). For example, the air filter (82) is made of a metal mesh made of stainless steel or the like.

[0063] <Fan Guard> The fan guard (84) is a protective fence that prevents fingers or other human body parts or foreign objects from entering the air passage (56) from the inlet (52). The fan guard (84) is located inward of the air filter (82) in the air passage (56) and between the air filter (82) and the cross-flow fan (70). The fan guard (84) is provided on the rear side of the air filter (82). The fan guard (84) is made of a plurality of rods (86). The rods (86) extend in the left-right direction and are spaced apart from one another along the rear side of the air filter (82). Each rod (86) is made of, for example, metal and is fixed to the casing (50).

[0064] <Intake Port, Intake Grill> As shown in Figures 5 and 6, the vertical width of the first intake port (52a) is larger than the diameter of the crossflow fan (70). This ensures a certain flow rate of air drawn into the air passage (56) by the operation of the crossflow fan (70). This allows air to circulate efficiently through the air passage (56). The first intake port (52a) is divided into three regions in relation to the crossflow fan (70) when viewed from the front. The first intake port (52a) has a first region (A1), a second region (A2), and a third region (A3).

[0065] The first region (A1) is a region that overlaps with the cross flow fan (70) in a front view of the first suction port (52a), i.e., in a front-to-rear view. An upper portion of the first region (A1) corresponds to a rotational portion of the cross flow fan (70) that faces the suction port (52). The second region (A2) is a region of the first suction port (52a) that is located on the tongue portion (63) side of the first region (A1) in the up-down direction. In this example, the second region (A2) is located above the first region (A1). The third region (A3) is a region of the first suction port (52a) that is located on the opposite side of the tongue portion (63) from the first region (A1) in the up-down direction. In this example, the third region (A3) is located below the first region (A1).

[0066] Each of the guide plates (92) constituting the suction grille (90) has a length corresponding to the left-right direction and a width perpendicular to the left-right direction. Each guide plate (92) is a fixed guide plate fixed in a specific orientation, and is indicated by dotted hatching in FIG. 5 . In this specification, the "orientation of the guide plate (92)" refers to the width direction of the guide plate (92) (the direction in which a second straight line (L2) described below extends) and is the direction in which air passing through the suction grille (90) is guided. The guide plates (92) include guide plates (92) oriented in different directions. The guide plates (92) include a first guide plate (92a), a second guide plate (92b), a third guide plate (92c), and a fourth guide plate (92d).

[0067] The first guide plate (92a) is the guide plate (92) located closest to the center (C1) of the cross flow fan (70). The second guide plate (92b) is the guide plate (92) located in the second region (A2) of the suction port (52). The third guide plate (92c) is the guide plate (92) located above the first guide plate (92a) in the first region (A1), i.e., between the first guide plate (92a) and the second guide plate (92b). The fourth guide plate (92d) is the guide plate located on the opposite side of the first guide plate (92a) from the second guide plate (92b). The fourth guide plate (92d) is located in the first region (A1) or the third region (A3) below the first guide plate (92a). In this example, a plurality of second guide plates (92b), a plurality of third guide plates (92c), and a plurality of fourth guide plates (92d) are provided.

[0068] Whether the guide plate (92) is located in the first region (A1), the second region (A2), or the third region (A3) depends on the region in which the center (C2) of the guide plate (92) is located in a cross section (hereinafter referred to as the target cross section) perpendicular to the left-right direction of the indoor unit (7). When the center (C2) of the guide plate (92) is located in the first region (A1), the guide plate (92) is the first guide plate (92a), the third guide plate (92c), or the fourth guide plate (92d). When the center (C2) of the guide plate (92) is located in the second region (A2), the guide plate (92) is the second guide plate (92b). When the center (C2) of the guide plate (92) is located in the third region (A3), the guide plate (92) is the fourth guide plate (92d). In this specification, the "center (C2) of the guide plate (92)" means the central position in the width direction of the guide plate (92) and the central position in the thickness direction of the guide plate (92) in the target cross section of the guide plate (92).

[0069] In the following, in the target cross section of the indoor unit (7), a line passing through the center of the guide plate (92) and the center (C2) of the cross flow fan (70) is defined as a first line (L1). In the target cross section of the indoor unit (7), a line passing through the upstream end (93a) located on the upstream side in the air flow direction of the guide plate (92) and the downstream end (93b) located on the downstream side is defined as a second line (L2). Furthermore, of the intersections of the outer peripheral surface (70a) of the cross flow fan (70) and the first line (L1), the point closest to the first suction port (52a) is defined as a first intersection (P1). Of the intersections of the outer peripheral surface (70a) of the cross flow fan (70) and the second line (L2), the point closest to the first suction port (52a) is defined as a second intersection (P2).

[0070] The first guide plate (92a), some of the second guide plates (92b), each of the third guide plates (92c), and each of the fourth guide plates (92d) are arranged such that the second straight line (L2) is inclined with respect to the front-to-rear direction. In this specification, when the second straight line (L2) of the guide plate (92) forms an upward inclination angle with respect to the imaginary line (L3) corresponding to the front-to-rear direction, the inclination angle is expressed with the prefix "up." When the second straight line (L2) of the guide plate (92) forms a downward inclination angle with respect to the imaginary line (L3) corresponding to the front-to-rear direction, the inclination angle is expressed with the prefix "down."

[0071] The first guide plate (92a) is disposed at an angle with respect to the front-rear direction so that the second intersection point (P2) is located rearward of the first intersection point in the direction of rotation of the crossflow fan (70). The first guide plate (92a) is angled with respect to the front-rear direction so that the second straight line (L2) extends upward toward the crossflow fan (70). The first angle of inclination θ1 formed by the second straight line (L2) of the first guide plate (92a) with respect to the front-rear direction satisfies 0°<θ1≦60°. In this example, the first angle of inclination θ1 is approximately 30° upward.

[0072] Like the first guide plate (92a), each fourth guide plate (92d) is inclined with respect to the front-rear direction so that the second straight line (L2) extends upward toward the crossflow fan (70). In this example, each fourth guide plate (92d) is provided in the same direction as the first guide plate (92a). That is, the fourth inclination angle θ4 formed by the second straight line (L2) of each fourth guide plate (92d) with respect to the front-rear direction satisfies 0°<θ1≦60°, similar to the first inclination angle θ1. The fourth inclination angle θ4 in this example is approximately 30° upward, the same as the first inclination angle θ1.

[0073] Each second guide plate (92b) is oriented such that the second straight line (L2) intersects with the outer peripheral surface (70a) of the crossflow fan (70). Each second guide plate (92b) is inclined with respect to the front-rear direction so that the second straight line (L2) extends downward toward the crossflow fan (70). In this example, each second guide plate (92b) is inclined with respect to the front-rear direction so that the second intersection point (P2) is located rearward of the first intersection point (P1) in the direction of rotation of the crossflow fan (70). The second inclination angle θ2 formed by the second straight line (L2) of each second guide plate (92b) with respect to the front-rear direction satisfies 0°≦θ2≦45°. In this example, the second inclination angle θ2 is approximately 30° downward.

[0074] Each third guide plate (92c) is oriented such that the third inclination angle θ3 that the second straight line (L2) forms with respect to the front-to-rear direction is an angle between the first inclination angle θ1 and the second inclination angle θ2. The third inclination angle θ3 varies depending on the position of the third guide plate (92c) in the up-down direction. The third inclination angle θ3 of the plurality of third guide plates (92c) varies stepwise from the bottom to the top such that the orientation of the third guide plate (92c) approaches the orientation of the second guide plate (92b) from the orientation of the first guide plate (92a). The plurality of third guide plates (92c) are oriented generally radially as a whole such that the second straight lines (L2) intersect with each other on the crossflow fan (70) side.

[0075] The third guide plate (92c) closer to the first guide plate (92a) has a third inclination angle θ3 smaller than the first inclination angle θ1 and is inclined with respect to the front-to-rear direction so that the second straight line (L2) extends upward toward the cross flow fan (70). The third guide plate (92c) closer to the second guide plate (92b) has a third inclination angle θ3 smaller than the second inclination angle θ2 and is inclined with respect to the front-to-rear direction so that the second straight line (L2) extends downward toward the cross flow fan (70). In this example, the third guide plate (92c) located midway in the up-down direction among the plurality of third guide plates (92c) is positioned so that the second straight line (L2) extends straight in the front-to-rear direction, i.e., the third inclination angle θ3 is 0°.

[0076] When the crossflow fan (70) rotates, indoor air is drawn from the suction port (52) through the suction grille (90), the air filter (82), and the fan guard (84) into the air passage (56). The indoor air drawn from the suction port (52) into the air passage (56) is guided by the guide plates (92) as it passes through the suction grille (90), and flows through the air filter (82) into the suction space (56a) with almost no change in flow direction. At this time, the air flow guided by the first guide plate (92a) pre-swirls the air flow drawn into the crossflow fan (70). The air flow guided by the second guide plate (92b) forms a smooth flow toward the crossflow fan (70).

[0077] -Air blowing performance of indoor unit- Fig. 10 shows the specifications of the guide plate (92) of the indoor unit (7) of the example and the indoor units (7) of the comparative examples 1 to 3, and the same air volume (9.45 m ３ 10 shows the rotation speed [rpm] of the cross flow fan (70) at a rotation speed (rpm) ...

[0078] The basic configuration of the indoor unit (7) of the example is the same as that of the embodiment shown in FIG. 6 . In the indoor unit (7) of the example, the number of guide plates (92) is 13, and the thickness of each guide plate (92) is 2.0 mm. Of the 13 guide plates (92), the seven lower guide plates (92) are the first guide plate (92a) and the fourth guide plate (92d). The first guide plate (92a) and the fourth guide plate (92d) are oriented such that the inclination angles (first inclination angle θ1, fourth inclination angle θ4) of the second straight line (L2) relative to the front-to-rear direction are 30° upward. The two upper guide plates (92) are the second guide plates (92b). The second guide plate (92b) is oriented such that the second inclination angle θ2 is 30° downward.

[0079] The indoor unit (7) of Comparative Example 1 has the same configuration as the indoor unit (7) of the Example, except for the number, thickness, and orientation of the guide plates (92). As shown in FIG. 7 , the indoor unit (7) of Comparative Example 1 has 12 guide plates (92). Each guide plate (92) has a thickness of 1.2 mm. The orientations of the 12 guide plates (92) are all horizontal, with the second straight line (L2) extending straight in the front-to-rear direction and the inclination angles (first to fourth inclination angles θ1 to θ4) of the second straight line (L2) relative to the front-to-rear direction being 0°.

[0080] The indoor unit (7) of Comparative Example 2 has the same configuration as the indoor unit (7) of the Example, except for the orientation of the guide plates (92). As shown in Fig. 8 , in the indoor unit (7) of Comparative Example 2, the orientations of all 13 guide plates (92) are uniform, with the inclination angles (first to fourth inclination angles θ1 to θ4) of the second straight line (L2) relative to the front-to-rear direction being upwards of 30°.

[0081] The indoor unit (7) of Comparative Example 3 has the same configuration as the indoor unit (7) of the Example, except for the orientation of the guide plates (92). As shown in FIG. 9 , in the indoor unit (7) of Comparative Example 3, of the thirteen guide plates (92), the four lower guide plates (92) are part of the fourth guide plates (92d). The orientation of these part of the fourth guide plates (92d) is such that the fourth inclination angle θ4 is upward by 30°. The five upper guide plates (92) are the second guide plates (92b) and part of the third guide plates (92c). The orientation of these second guide plates (92b) and part of the third guide plates (92c) is such that the inclination angles (second inclination angle θ2, third inclination angle θ3) of the second straight line (L2) relative to the front-to-rear direction are downward by 30°. The other guide plates (92) (the first guide plate (92a), the remaining third guide plate (92c), and the fourth guide plate (92d)) are arranged in a generally radial orientation as a whole, similar to the third guide plate (92c) of the above embodiment. The orientations of the other guide plates (92) are such that the inclination angles (second inclination angle θ2, third inclination angle θ3) formed with respect to the front-to-rear direction of the second straight line (L2) from the lower guide plate (92) toward the upper guide plate (92) are between 30° upward and 30° downward.

[0082] As shown in FIG. 10, the indoor unit (7) of the embodiment has a same air volume (9.45 m ３ / min) is lower than that of the indoor units (7) of Comparative Examples 1 to 3. Thus, according to the indoor unit (7) of the example, even if the rotation speed of the cross flow fan (70) is relatively low, the same air volume (9.45 m ３ / min) can be achieved because the first guide plate (92a) pre-swirls the flow of air sucked into the cross flow fan (70), thereby increasing the pressure of the cross flow fan (70), while allowing the air that is guided by the second guide plate (92b) when passing through the suction opening (52) and sucked into the air passage (56) to flow smoothly into the cross flow fan (70), thereby reducing loss in the cross flow fan (70). As a result, the energy efficiency of the indoor unit (7) can be improved.

[0083] - Features of the embodiment - In the indoor unit (7) of this embodiment, the air inlet (52) has a first region (A1) corresponding to the cross flow fan (70) as viewed in the front-to-rear direction, and a second region (A2) located on the tongue portion (63) side in the up-down direction relative to the first region (A1). Of the multiple guide plates (92) provided at the air inlet (52), a first guide plate (92a) located closest to the center (C1) of the cross flow fan (70) in the first region (A1) is provided at an angle with respect to the front-to-rear direction. The first guide plate (92a) is oriented such that, in the symmetric cross section of the indoor unit (7), a second intersection (P2) of the outer peripheral surface (70a) of the cross flow fan (70) and the second straight line (L2), which is closer to the inlet (52), is located behind, in the rotation direction of the cross flow fan (70), a first intersection (P1) of the outer peripheral surface (70a) of the cross flow fan (70) and the first straight line (L1), which is closer to the inlet (52). The first guide plate (92a) imparts a pre-swirl to the flow of air sucked into the cross flow fan (70) in the direction opposite to the rotation direction of the cross flow fan (70), thereby increasing the pressure of the cross flow fan (70).

[0084] As shown in FIG. 15 , if all the guide plates (92) are uniformly arranged in the same orientation as the first guide plate (92a), the air guided by the second guide plate (92b) located in the second region (A2) among the guide plates (92) flows radially outward of the crossflow fan (70) and is then drawn into the crossflow fan (70). Therefore, the air guided by the guide plate (92) closer to the upper edge of the inlet (52) travels a longer path to the crossflow fan (70), resulting in losses in the crossflow fan (70). In contrast, in the indoor unit (7) of this embodiment, the second guide plate (92b) is arranged in a different orientation from the first guide plate (92a). The second guide plate (92b) is oriented at a second inclination angle θ2, opposite the side at which the first guide plate (92a) forms the first inclination angle θ1 with respect to the front-rear direction. As a result, compared to when the second guide plate (92b) assumes the same position as the first guide plate (92a), the air that is guided by the second guide plate (92b) when passing through the suction opening (52) and is sucked into the casing (50) can flow more smoothly to the cross flow fan (70), as shown in Fig. 11. This reduces loss in the cross flow fan (70).

[0085] In the indoor unit (7) of this embodiment, the third guide plate (92c), which is located between the first guide plate (92a) and the second guide plate (92b) among the plurality of guide plates (92), is oriented differently from the first guide plate (92a) and the second guide plate (92b). The orientation of the third guide plate (92c) is such that the third inclination angle θ3 formed by the second straight line (L2) with respect to the front-to-rear direction is between the first inclination angle θ1 and the second inclination angle θ2. The third guide plate (92c) prevents the orientation of the plurality of guide plates (92) from significantly changing between the first guide plate (92a) and the second guide plate (92b). This reduces the collision of air flows guided by adjacent guide plates (92) when passing through the air inlet (52). This is advantageous for reducing losses in the crossflow fan (70).

[0086] In the indoor unit (7) of this embodiment, the suction space (56a) in the casing (50) corresponds to the second region (A2) in the front-rear direction and extends to correspond to the portion of the cross-flow fan (70) on the suction port (52) side in the up-down direction. Including such a suction space (56a) in the casing (50) ensures a large opening area for the suction port (52). However, when the second guide plate (92b) assumes the same position as the first guide plate (92a), the air passing through the suction port (52) is guided by the second guide plate (92b) radially outward from the cross-flow fan (70), which tends to increase loss in the cross-flow fan (70). Therefore, the technology of the present disclosure is particularly effective for the indoor unit (7).

[0087] In the indoor unit (7) of this embodiment, the first inclination angle θ1 formed by the second straight line (L2) of the first guide plate (92a) with respect to the front-to-rear direction is greater than 0° and not greater than 60°. When the first inclination angle θ1 is 60° or less, it is possible to prevent excessive resistance (ventilation resistance) when the air passes through the inlet (52), and to suitably impart pre-swirl to the flow of air drawn into the cross flow fan (70).

[0088] In the indoor unit (7) of this embodiment, the second guide plate (92b) is inclined toward the opposite side to the first guide plate (92a) with respect to the front-rear direction, and a second inclination angle θ2 formed by a second straight line (L2) of the second guide plate (92b) with respect to the front-rear direction is greater than or equal to 0° and less than or equal to 45°. When the second inclination angle θ2 is 45° or less, the air passing through the inlet (52) can be guided toward the crossflow fan (70) by the second guide plate (92b) while preventing excessive resistance (ventilation resistance) when the air passes through the inlet (52).

[0089] The air conditioner (1) of this embodiment includes an indoor unit (7). The indoor unit (7) can reduce loss in the crossflow fan (70). This can improve the energy-saving performance of the air conditioner (1).

[0090] First Modification As shown in FIG. 12 , in the indoor unit (7), each of the plurality of fourth guide plates (92d) is oriented such that the fourth inclination angle θ4 is greater than the first inclination angle θ1. The farther the fourth guide plate (92d) is from the first guide plate (92a), the larger the fourth inclination angle θ4 of the fourth guide plate (92d). That is, the fourth inclination angle θ4 of the plurality of fourth guide plates (92d) increases stepwise from the top to the bottom. The fourth inclination angles θ4 of the respective fourth guide plates (92d) satisfy the relationship 30<θ4≦60° and differ from one another by several degrees. The fourth inclination angle θ4 may be different for all of the fourth guide plates (92d), or may be the same for only some of the adjacent fourth guide plates (92d) and different for the other fourth guide plates (92d).

[0091] In the indoor unit (7) of this first modified example, each fourth guide plate (92d) is oriented such that the fourth inclination angle θ4 is greater than the first inclination angle θ1. The fourth guide plate (92d) is a guide plate (92) disposed on the opposite side of the first guide plate (92a) from the second guide plate (92b), and the fourth inclination angle θ4 increases with increasing distance from the first guide plate (92a). The fourth guide plate (92d) prevents the orientation of the multiple guide plates (92) from changing significantly on the opposite side of the first guide plate (92a) from the second guide plate (92b). This reduces collisions between air flows guided by adjacent guide plates (92) as they pass through the air inlet (52). This is advantageous for reducing losses in the crossflow fan (70).

[0092] 13 , each second guide plate (92b) may be oriented such that the second inclination angle θ2 is smaller than the first inclination angle θ1 of the first guide plate (92a). In this example, each second guide plate (92b) is oriented such that the second straight line (L2) extends straight in the front-rear direction, i.e., the second inclination angle θ2 is 0°. In this case, the third guide plate (92c) closer to the second guide plate (92b) may also be oriented such that the third inclination angle θ3 is 0°. Alternatively, only some of the second guide plates (92b) may be oriented such that the second inclination angle θ2 is 0°.

[0093] The indoor unit (7) of the second modified example also achieves the same effects as those of the above embodiment. That is, the first guide plate (92a) pre-swirls the flow of air sucked into the cross flow fan (70), thereby increasing the pressure of the cross flow fan (70), while allowing the air that is guided by the second guide plate (92b) when passing through the suction opening (52) and sucked into the air passage (56) to flow smoothly into the cross flow fan (70), thereby reducing loss in the cross flow fan (70).

[0094] Other Embodiments As shown in Fig. 14, each second guide plate (92b) may be oriented such that the second inclination angle θ2 is greater than 0° and smaller than the first inclination angle θ1 of the first guide plate (92a). For example, the second inclination angle θ2 of each second guide plate (92b) satisfies 0° < θ2 < 30°. As a specific example, the first inclination angle θ1 of the first guide plate (92a) is approximately 30° upward, while the second inclination angle θ2 of each second guide plate (92b) is approximately 10° upward. With such a configuration, the same effects as those of the above embodiment can be obtained.

[0095] In the indoor unit (7) having the above configuration, the third guide plate (92c) closer to the second guide plate (92b) may also be oriented such that the third inclination angle θ3 is the same as the second inclination angle θ2. Alternatively, only some of the second guide plates (92b) may be oriented such that the second inclination angle θ2 is greater than 0° and smaller than the first inclination angle θ1 of the first guide plate (92a) (for example, an upward orientation of approximately 10°).

[0096] The suction port (52) formed in the casing (50) may be only the first suction port (52a). For example, the indoor unit (7) of the above embodiment may not have the second suction port (52b). The suction port (52) may have only the first region (A1) and the second region (A2), and may not have the third region (A3).

[0097] The positions of the suction inlet (52) and the discharge outlet (54) in the casing (50) and the configuration of the air passage (56) may be changed as desired. For example, in the indoor unit (7) of the above embodiment, the positions of the suction inlet (52) and the discharge outlet (54) may be reversed. That is, the suction inlet (52) may be formed on the top surface of the casing (50), and the discharge outlet (54) may be formed on the lower front surface of the casing (50).

[0098] The air conditioner (1) may be configured as a dedicated heating machine capable of performing only heating operation without including a four-way selector valve (22) in the refrigerant circuit (10). In this case, the indoor unit (7) may be configured as, for example, a fan convector. Alternatively, the air conditioner (1) may be configured as a dedicated cooling machine capable of performing only cooling operation.

[0099] The air conditioner (1) does not necessarily have to include the hot water supply unit (5). For example, the indoor heat exchanger (80) may be included in the refrigerant circuit (10) instead of the water heat exchanger (20). In this case, refrigerant flows through the indoor heat exchanger (80). The indoor heat exchanger (80) is configured to exchange heat between the refrigerant flowing therethrough and indoor air.

[0100] A floor heating device may be connected to the cooling / heating hot water supply system constituting the air conditioner (1). In this case, the floor heating device may be configured to perform floor heating using hot water (hot water) stored in the water storage tank (40). Furthermore, a solar power generation device may be connected to the cooling / heating hot water supply system. In this case, the system may be configured to heat the water in the water storage tank (40) using electricity generated by the solar power generation device.

[0101] The indoor unit (7) may be arranged on the front side of the ceiling and suspended from the ceiling, or may be arranged on the back side of the ceiling and suspended from a ceiling beam, or may be a floor-standing unit.

[0102] The air conditioner (1) may include a plurality of indoor units (7). Furthermore, the space to be cooled and heated by the air conditioner (1) is not limited to an indoor space. The target space may be a space inside a warehouse or the like, or a space inside a factory.

[0103] The heat exchange unit according to the present disclosure may be a functional unit other than the indoor unit (7), such as an outdoor unit (3), as long as it houses a cross-flow fan and a heat exchanger in a casing and generates pre-swirl in the flow of air drawn into the cross-flow fan by a guide plate provided at the intake port of the casing.

[0104] Although the embodiments and modifications have been described above, it will be understood that various modifications in form and details are possible without departing from the spirit and scope of the claims. Furthermore, the above embodiments and modifications may be combined or substituted as appropriate as long as the functionality of the subject matter of the present disclosure is not impaired.

[0105] In addition, the terms "first," "second," "third," etc. in the specification and claims are used to distinguish between the terms to which these terms are attached, and do not limit the number or order of the terms.

[0106] INDUSTRIAL APPLICABILITY As described above, the present disclosure is useful for heat exchange units and air conditioners.

[0107] A1 First area A2 Second area C1 Center of cross flow fan C2 Center of guide plate L1 First line L2 Second line P1 First intersection P2 Second intersection Ra Rotation axis 1 Air conditioning unit 7 Indoor unit (heat exchange unit) 50 Casing 52 Intake port 54 Outlet 56 Air passage 56a Intake space 63 Tongue 70 Cross flow fan 80 Indoor heat exchanger (heat exchanger) 92 Guide plate 92a First guide plate 92b Second guide plate 92c Third guide plate 92d Fourth guide plate 93a Upstream end 93b Downstream end

Claims

1. A heat exchanger (80) comprising: a casing (50) having an intake port (52), an outlet port (54), and an air passage (56) connecting the intake port (52) and the outlet port (54); a cross-flow fan (70) accommodated in the air passage (56); and a heat exchanger (80) arranged in the air passage (56) downstream of the cross-flow fan (70), wherein the cross-flow fan (70) is arranged at a position corresponding to the intake port (52) in a first direction perpendicular to the opening surface of the intake port (52) and rotates around a rotation axis (Ra) extending along a second direction perpendicular to the first direction; a tongue portion (63) forming a wall surface of the air passage (56) is provided in the casing (50) along a part of the outer periphery of the cross-flow fan (70) on one side of the cross-flow fan (70) in a third direction perpendicular to the first direction and the second direction; the suction port (52) has a first region (A1) overlapping with the cross flow fan (70) as viewed in the first direction, and a second region (A2) located on the tongue portion (63) side of the first region (A1) in the third direction, the suction port (52) is provided with a plurality of guide plates (92) each extending in the second direction and arranged at intervals from one another in the third direction, the plurality of guide plates (92) including a first guide plate (92a) located closest to a center (C1) of the cross flow fan (70) in the first region (A1) and a second guide plate (92b) located in the second region (A2), in a cross section perpendicular to the second direction, a straight line passing through the center (C2) of the guide plate (92) and the center (C1) of the cross flow fan (70) is defined as a first straight line (L1), A straight line passing through an upstream end (93a) located on the upstream side in the air flow direction of the guide plate (92) and a downstream end (93b) located on the downstream side is defined as a second straight line (L2), a point of intersection between the outer peripheral surface (70a) of the cross flow fan (70) and the first straight line (L1) that is closer to the suction port (52) is defined as a first intersection point (P1), and a point of intersection between the outer peripheral surface (70a) of the cross flow fan (70) and the second straight line (L2) that is closer to the suction port (52) is defined as a second intersection point (P2),the first guide plate (92a) is oriented inclined with respect to the first direction so that the second intersection (P2) is located rearward of the first intersection (P1) in the rotation direction of the cross flow fan (70); and the second guide plate (92b) is oriented such that a second inclination angle formed by the second straight line (L2) of the second guide plate (92b) with respect to the first direction is smaller than a first inclination angle formed by the second straight line (L2) of the first guide plate (92a) with respect to the first direction, or such that the second inclination angle is on a side opposite to a side at which the first guide plate (92a) forms the first inclination angle with respect to the first direction.

2. A heat exchange unit according to claim 1, wherein the plurality of guide plates (92) include a third guide plate (92c) located between the first guide plate (92a) and the second guide plate (92b) in the first region (A1), and the third guide plate (92c) is oriented such that a third inclination angle formed by the second straight line (L2) of the third guide plate (92c) with respect to the first direction is an angle between the first inclination angle and the second inclination angle.

3. A heat exchange unit according to claim 1 or 2, wherein the air passage (56) includes an intake space (56a) provided between the intake port (52) and the cross-flow fan (70), and the intake space (56a) corresponds to the second area (A2) in the first direction and extends to correspond to a portion of the cross-flow fan (70) on the intake port (52) side in the third direction.

4. A heat exchange unit according to any one of claims 1 to 3, wherein the third direction corresponds to the up-down direction, the cross flow fan (70) rotates such that blades (76) of the cross flow fan (70) move from top to bottom on the inlet (52) side, the first guide plate (92a) is inclined with respect to the first direction so that the second straight line (L2) extends upward toward the cross flow fan (70), and the second guide plate (92b) is located higher than the first guide plate (92a) and is inclined with respect to the first direction so that the second straight line (L2) extends downward toward the cross flow fan (70), or the second straight line (L2) is parallel to the first direction.

5. A heat exchange unit according to any one of claims 1 to 4, wherein the first tilt angle θ1 satisfies 0°<θ1≦60°.

6. A heat exchange unit according to any one of claims 1 to 5, wherein the second guide plate (92b) is provided in a position where it forms the second inclination angle on a side opposite to the side where the first guide plate (92a) forms the first inclination angle with respect to the first direction, and the second inclination angle θ2 satisfies 0°≦θ2≦45°.

7. A heat exchange unit according to any one of claims 1 to 6, wherein the plurality of guide plates (92) include a plurality of fourth guide plates (92d) arranged on the opposite side of the first guide plate (92a) from the second guide plate (92b), and wherein each of the plurality of fourth guide plates (92d) is oriented such that a fourth inclination angle formed by the second straight line (L2) of the fourth guide plate (92d) with respect to the first direction is larger than the first inclination angle, and wherein the fourth inclination angle increases as the fourth guide plate (92d) forming the fourth inclination angle becomes farther away from the first guide plate (92a).

8. An air conditioner comprising a heat exchange unit (7) according to any one of claims 1 to 7.

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