Heat exchange unit and air conditioning system

Abstract

In a heat exchange unit that generates pre-swirl using a guide plate provided at the intake port, the losses of the cross-flow fan are reduced. [Solution] In the indoor unit (7), a cross-flow fan (70) housed in a casing (50) is positioned at a location corresponding to the intake port (52). The intake port has a first region (A1) that overlaps with the cross-flow fan in a front view, and a second region (A2) located on the tongue portion (63) side provided inside the casing relative to the first region. Of the multiple guide plates provided at the intake port, the first guide plate (92a) closest to the center of the cross-flow fan in the first region is provided in an upward position extending upward toward the cross-flow fan, and the second guide plate (92b) located in the second region is provided in a downward position extending downward toward the cross-flow fan.

Description

Technical Field

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

Background Art

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

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the heat exchange unit as described above, a plurality of guide plates for guiding air sucked into the air passage by the operation of the cross-flow fan are provided at intervals in the vertical direction at the intake port. In this heat exchange unit, the cross-flow fan is provided near the intake port, and the guide plate located close to the cross-flow fan is oriented to guide air in the direction opposite to the rotation direction of the cross-flow fan, so as to impart pre-rotation to the flow of air sucked into the cross-flow fan and increase the pressure of the cross-flow fan.

[0005] Furthermore, in the heat exchange unit, the vertical width of the intake port is made larger than the diameter of the cross-flow fan, thereby ensuring sufficient airflow into the air passage. The operation of the cross-flow fan then allows for efficient air circulation through the air passage. In this case, multiple guide plates are arranged to cover the entire opening surface of the intake port. Therefore, guide plates are also provided in positions that do not overlap with the cross-flow fan when viewed from the front. In a configuration in which all guide plates are provided in a uniform orientation that causes pre-swirl at the intake port, the following unique challenges arise.

[0006] As shown in Figure 15, when the intake port (52a) is formed to be larger than the diameter of the cross-flow fan (70), if the multiple guide plates (92) are oriented uniformly, the air guided by the guide plate (92) near the upper edge of the intake port (52a), which is located in a position that does not overlap with the cross-flow fan (70) in a front view on the tongue portion (63) side of the wall surface of the air passage (56) provided along a part of the outer circumference of the cross-flow fan (70), flows radially outward from the cross-flow fan (70) before being drawn into the cross-flow fan (70). As a result, the path of the air guided by the guide plate (92) near the upper edge of the intake port (52a) to the cross-flow fan (70) becomes longer, leading to losses in the cross-flow fan (70).

[0007] The purpose of this disclosure is to reduce losses in a cross-flow fan in a heat exchange unit that generates pre-swirl by a guide plate provided at the intake port. [Means for solving the problem]

[0008] A first aspect of the present disclosure relates to a heat exchange unit (7). The heat exchange unit (7) comprises a casing (50) having an inlet (52), an outlet (54), and an air passage (56) connecting the inlet (52) and the outlet (54); a cross-flow fan (70) housed in the air passage (56); and a heat exchanger (80) positioned downstream of the cross-flow fan (70) in the air passage (56). The cross-flow fan (70) is positioned at a location corresponding to the inlet (52) in a first direction perpendicular to the opening surface of the inlet (52), and rotates about a rotation axis (Ra) extending along a second direction perpendicular to the first direction. The casing (50) has a tongue portion (63) that forms the wall surface of the air passage (56), which is provided along a part of the outer circumference of the cross-flow fan (70) on one side in a third direction perpendicular to the first and second directions relative to the cross-flow fan (70). The intake port (52) has a first region (A1) that overlaps with the cross-flow fan (70) when viewed in the first direction, and a second region (A2) located on the tongue portion (63) side in the third direction relative to the first region (A1). The intake port (52) is provided with a plurality of guide plates (92) that extend in the second direction and are spaced apart from each other in the third direction. The plurality of guide plates (92) include a first guide plate (92a) located closest to the 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, the line passing through the center (C2) of the guide plate (92) and the center (C1) of the cross-flow fan (70) is defined as the first line (L1), and the line passing through the upstream end located on the upstream side and the downstream end located on the downstream side in the airflow direction of the guide plate (92) is defined as the second line (L2), and the intersection point of the outer circumferential surface (70a) of the cross-flow fan (70) and the first line (L1) is the intake port ( If we define the point closest to 52) as the first intersection (P1), and define the point closest to the intake port (52) among the intersections of the outer surface (70a) of the cross-flow fan (70) and the second straight line (L2) as the second intersection (P2), then the first guide plate (92a) is provided in an inclined direction with respect to the first direction such that the second intersection (P2) is located on the rear side of the cross-flow fan (70) in the rotational direction relative to the first intersection (P1). The second guide plate (92b) is provided in an orientation such that the second inclination angle made 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 made by the second straight line (L2) of the first guide plate (92a) with respect to the first direction, or in an orientation such that the second inclination angle is on the opposite side of the first inclination angle made by the first guide plate (92a) with respect to the first direction.

[0009] In the first embodiment, the intake port (52) has a first region (A1) that corresponds to the cross-flow fan (70) in a first view, and a second region (A2) located on the tongue (63) side in a third direction relative to the first region (A1). Of the multiple guide plates (92) provided in the intake port (52), the first guide plate (92a) located closest to the center (C1) of the cross-flow fan (70) in the first region (A1) is provided in an inclined direction with respect to the first direction. The orientation of the first guide plate (92a) is such that, in a cross section perpendicular to the second direction, the second intersection (P2) between the outer surface (70a) of the cross-flow fan (70) and the second straight line (L2), which is closer to the intake port (52), is positioned behind the first intersection (P1) between the outer surface (70) of the cross-flow fan (70) and the first straight line (L1), which is closer to the intake port (52), in the direction of rotation of the cross-flow fan (70). This first guide plate (92a) imparts a pre-swirl to the airflow drawn into the cross-flow fan (70) in the opposite direction to the rotation of the cross-flow fan (70), thereby increasing the pressure of the cross-flow fan (70). In addition, the second guide plate (92b) located in the second region (A2) among the multiple guide plates (92) is provided in a different orientation from the first guide plate (92a). The orientation of the second guide plate (92b) is 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 opposite side to the side on which the first guide plate (92a) forms the first inclination angle with respect to the first direction. With this orientation, compared to the case where the second guide plate (92b) takes the same orientation as the first guide plate (92a), the air that is guided by the second guide plate (92b) and drawn into the air passage (56) when passing through the intake port (52) can be smoothly flowed to the cross-flow fan (70). This reduces the losses of the cross-flow fan (70).

[0010] A second aspect of the present disclosure is a heat exchange unit (7) of the first aspect, wherein the plurality of guide plates (92) have 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 provided in such a orientation that the third inclination angle made 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.

[0011] In the second embodiment, a third guide plate (92c) located between the first guide plate (92a) and the second guide plate (92b) among the plurality of guide plates (92) is provided in a different orientation 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 made 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. This third guide plate (92c) suppresses a large change in the orientation of the plurality of guide plates (92) between the first guide plate (92a) and the second guide plate (92b). This makes it possible to mitigate collisions between airflows guided by adjacent guide plates (92) when passing through the intake port (52). This is advantageous in reducing losses of the cross-flow fan (70).

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

[0013] In a third embodiment, the suction space (56a) within the casing (50) expands to correspond with the second region (A2) in a first direction and to correspond with the portion of the cross-flow fan (70) on the intake port (52) side in a third direction. Including such a suction space (56a) in the air passage (56) allows for a larger opening area of ​​the intake port (52). However, when the second guide plate (92b) takes the same orientation as the first guide plate (92a), the air passing through the intake port (52) is guided by the second guide plate (92b) toward the radially outward direction of the cross-flow fan (70), which tends to increase the losses of the cross-flow fan (70). Therefore, the technology of this disclosure is particularly effective in the heat exchange unit (7).

[0014] A fourth aspect of the present disclosure is a heat exchange unit (7) in any one of the first to third aspects, wherein the third direction corresponds to the vertical direction. The cross-flow fan (70) rotates such that the blades (76) of the cross-flow fan (70) move from top to bottom on the intake port (52) side. The first guide plate (92a) is inclined with respect to the first direction such 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 such that the second straight line (L2) extends downward toward the cross-flow fan (70), or the second straight line (L2) is in a position parallel to the first direction.

[0015] A fifth aspect of the present disclosure is a 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 embodiment, the first inclination angle θ1 made by the second straight line (L2) of the first guide plate (92a) with respect to the first direction is 0° or more and 60° or less. When the first inclination angle θ1 is 60° or less, it is possible to suitably impart a pre-swirling motion to the airflow drawn into the cross-flow fan (70) while suppressing excessive resistance (airflow resistance) as the air passes through the intake.

[0017] A sixth aspect of the present disclosure is a heat exchange unit (7) of any one of the first to fifth aspects, wherein the second guide plate (92b) is positioned such that it forms the second inclination angle with respect to the first direction on the side opposite to the side on which the first guide plate (92a) forms the first inclination angle. The second inclination angle θ2 satisfies 0° ≤ θ2 ≤ 45°.

[0018] In the sixth embodiment, the second guide plate (92b) is inclined in the opposite direction to the first guide plate (92a) with respect to the first direction, and the second inclination angle θ2 made by the second straight line (L2) of the second guide plate (92b) with respect to the first direction is 0° or more and 45° or less. When the second inclination angle θ2 is 45° or less, the air passing through the intake port (52) can be guided by the second guide plate (92b) toward the cross-flow fan (70) while suppressing excessive resistance (airflow resistance) as the air passes through the intake port (52).

[0019] A seventh aspect of the present disclosure is a heat exchange unit (7) in any one of the first to sixth aspects, wherein the plurality of guide plates (92) have 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 provided in a direction in which the fourth inclination angle that the second straight line (L2) of the fourth guide plate (92d) makes with respect to the first direction is greater than the first inclination angle. The fourth inclination angle increases as the fourth guide plate (92d) making the fourth inclination angle moves 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 provided in a direction in which the fourth inclination angle formed by the second straight line (L2) with respect to the first direction is larger than the first inclination angle. The fourth guide plate (92d) is a guide plate (92) arranged on the opposite side of the second guide plate (92b) with respect to the first guide plate (92a), and forms a larger fourth inclination angle as it moves away from the first guide plate (92a). With this fourth guide plate (92d), it is possible to suppress a large change in the orientation of the plurality of guide plates (92) on the opposite side of the second guide plate (92b) with respect to the first guide plate (92a). Thereby, it is possible to mitigate the collision of the air flows guided by the guide plates (92) adjacent to each other when passing through the suction port (52). This is advantageous for reducing the loss of the cross-flow fan (70).

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

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

Brief Description of the Drawings

[0023] [Figure 1] FIG. 1 is a schematic configuration diagram of the air conditioner according to the embodiment. [Figure 2] ​​​​​​​​​​​​​​​Figure 7 is a cross-sectional view illustrating the main parts of the indoor unit of Comparative Example 1. [Figure 8] Figure 8 is a cross-sectional view illustrating the main parts of the indoor unit of Comparative Example 2. [Figure 9] Figure 9 is a cross-sectional view illustrating the main parts of the indoor unit of Comparative Example 3. [Figure 10] Figure 10 is a table showing the specifications of the guide plates for the examples and comparative examples 1 to 3, along with the rotation speed at the same airflow.

[0024] [Figure 11] Figure 11 is a cross-sectional view illustrating the airflow in the main part of the indoor unit. [Figure 12] Figure 12 is a cross-sectional view of the main part of the indoor unit of the first modified example, corresponding to Figure 6. [Figure 13] Figure 13 is a cross-sectional view of the main part of the indoor unit of the second modified example, corresponding to Figure 6. [Figure 14] Figure 14 is a cross-sectional view of the main part of the indoor unit of another embodiment, corresponding to Figure 6. [Figure 15] Figure 15 is a cross-sectional view illustrating the airflow in the main part of the indoor unit when all guide plates are tilted upwards towards the rear with respect to the horizontal direction. [Modes for carrying out the invention]

[0025] The following exemplary embodiments will be described in detail with reference to the drawings. The following embodiments will be examples of the application of the heat exchange unit according to the present disclosure to an air conditioning system. The drawings are intended to conceptually illustrate the technology of the present disclosure. Therefore, in order to facilitate understanding of the technology of the present disclosure, dimensions, ratios, or numbers may be exaggerated or simplified in the drawings.

[0026] -Configuration of an air conditioning system- The heat exchange unit of this embodiment is used in an air conditioning system (1). The air conditioning system (1) consists of a heat pump type heating, cooling, and hot water supply system. As shown in Figure 1, the air conditioning system (1) comprises 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 installed indoors, respectively.

[0027] <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 houses the entire closed-circuit refrigerant circuit (10). The casing houses the equipment that makes up the refrigerant circuit (10), such as the compressor (14), outdoor heat exchanger (16), expansion valve (18), and water heat exchanger (20), as well as the outdoor fan (12).

[0028] The refrigerant circuit (10) performs the refrigeration cycle. The refrigerant circuit (10) is filled with refrigerant. The refrigerant in the refrigerant circuit (10) may be, for example, HFC (Hydro Fluoro Carbon) refrigerant, HFO (Hydro Fluoro Olefin) refrigerant, a mixture of HFC and HFO refrigerants, CF3I (Trifluoroiodomethane) refrigerant, carbon dioxide refrigerant, hydrocarbon refrigerant, or a natural refrigerant such as propane (R290) or ammonia (R717).

[0029] The refrigerant circuit (10) mainly comprises a compressor (14), an outdoor heat exchanger (16), an expansion valve (18), and a water heat exchanger (20). The refrigerant circuit (10) further comprises a four-way directional valve (22) and an accumulator (24). The compressor (14) and the four-way directional valve (22), the four-way directional 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 directional valve (22), the four-way directional valve (22) and the accumulator (24), and the accumulator (24) and the compressor (14) are each connected by refrigerant piping (26).

[0030] The compressor (14) compresses the refrigerant. The compressor (14) is configured to have a variable capacity by inverter control. The accumulator (24) stores the liquid in the refrigerant that is drawn into the compressor (14). The outdoor heat exchanger (16) exchanges heat between the refrigerant flowing inside and the outdoor air. The refrigerant from the refrigerant circuit (10) flows inside the outdoor heat exchanger (16). The outdoor fan (12) generates airflow and transports the air to pass 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 from the refrigerant circuit (10) and the water from the water circuit (30).

[0031] The four-way directional control valve (22) switches the circulation direction of the refrigerant in the refrigerant circuit (10). The four-way directional control 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 directional control valve (22) switches between a first state (shown by the solid line in Figure 1) and a second state (shown by the dashed line in Figure 1).

[0032] The first state of the four-way directional control valve (22) is a state in which the first port (22a) and the third port (22c) are connected, and the second port (22b) and the fourth port (22d) are connected. The second state of the four-way directional control valve (22) is a state in which the first port (22a) and the second port (22b) are connected, and the third port (22c) and the fourth port (22d) are connected. When the four-way directional control valve (22) is in the first state, the refrigerant in the refrigerant circuit (10) flows in the direction of the arrows shown by the solid lines in Figure 1, the outdoor heat exchanger (16) functions as an evaporator, and the water heat exchanger (20) functions as a heat 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 arrows shown by the dashed lines in Figure 1, the outdoor heat exchanger (16) functions as a heat radiator, and the water heat exchanger (20) functions as an evaporator.

[0033] <Hot water supply unit> The hot water supply unit (5) stores water heated by the outdoor unit (3). The hot water supply unit (5) is comprised of a water circuit (30). A water heat exchanger (20) and an indoor heat exchanger (80) are connected to the water circuit (30). The water circuit (30) includes a 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 an 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 all connected by water piping (42).

[0034] 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). A hot water supply heat transfer pipe (44) is provided in the water storage tank (40). A water supply source such as a water supply pipe (46) is connected to the inlet of the hot water supply heat transfer pipe (44). A hot water supply device is connected to the outlet of the hot water supply heat transfer pipe (44) via a hot water supply pipe (48).

[0035] The hot water supply equipment consists of faucets and shower taps within the building that can supply hot water. Water sent from the water source to the water storage tank (40) via the water supply pipe (46) is then sent to the hot water supply equipment through the hot water heat transfer pipe (44) and the 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), becoming hot water at approximately 40°C to 50°C. The hot water temperature is adjusted in the hot water supply equipment using a mixing faucet or the like.

[0036] The pump (32) sends the water it draws in to the water heat exchanger (20) and circulates it in the water circuit (30). The first check valve (36) and the second check valve (38) are installed in the water piping (42) that connects the water storage tank (40) and the indoor heat exchanger (80). The water piping (42) that connects the water storage tank (40) and the indoor heat exchanger (80) constitutes a branch pipe (43) formed by the joining of three water pipes (42). The suction side of the pump (32) is connected to the section of the branch pipe (43) between the first check valve (36) and the second check valve (38).

[0037] The first check valve (36) is located on the indoor heat exchanger (80) side of the branch pipe (43) relative to its branching point. The second check valve (38) is located on the water storage tank (40) side of the branch pipe (43) relative to its branching point. 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 the reverse flow. The second check valve (38) allows water to flow from the water storage tank (40) to the pump (32) in the branch pipe (43) and prevents the reverse flow. 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.

[0038] The first state of the three-way valve (34) is when water is circulated between the water heat exchanger (20) and the indoor heat exchanger (80). The second state of the three-way valve (34) is when water is circulated between the water heat exchanger (20) and the water storage tank (40). When the three-way valve (34) is in the first state, the water discharged from the pump (32) flows sequentially through the three-way valve (34), the indoor heat exchanger (80), and the first check valve (36), as shown by the solid line in Figure 1, and is then drawn back into the pump (32). When the three-way valve (34) is in the second state, the water discharged from the pump (32) flows sequentially through the three-way valve (34), the water storage tank (40), and the second check valve (38), as shown by the dashed line in Figure 1, and is then drawn back into the pump (32).

[0039] <Indoor Unit> The indoor unit (7) cools or heats the indoor space using the heat from the water supplied by the water circuit (30). The indoor unit (7) is a fan coil unit. The indoor unit (7) comprises a cross-flow fan (70) as an indoor fan and an indoor heat exchanger (80). The indoor unit (7) further comprises a casing (50) (not shown in Figure 1). The cross-flow fan (70) and the indoor heat exchanger (80) are housed inside the casing (50).

[0040] The indoor heat exchanger (80) exchanges heat between the water flowing inside and the indoor air. Water from the water circuit (30) flows inside the indoor heat exchanger (80). The cross-flow fan (70) generates airflow and transports air to pass through the indoor heat exchanger (80). When the low-temperature water cooled in the water heat exchanger (20) is sent to the indoor heat exchanger (80), the air transported by the cross-flow fan (70) is cooled in the indoor heat exchanger (80). When the high-temperature water heated in the water heat exchanger (20) is sent to the indoor heat exchanger (80), the air transported by the cross-flow fan (70) is heated in the indoor heat exchanger (80).

[0041] -Operation of the air conditioning system- The air conditioning system (1) performs both cooling and heating operations.

[0042] <Air conditioning operation> Cooling operation is the operation of cooling the air in the indoor space. In cooling operation, the four-way switching valve (22) and the three-way valve (34) are set to the first state, and the compressor (14), outdoor fan (12), pump (32), and cross-flow fan (70) are operated. During 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). Then, the air transported by the cross-flow fan (70) is cooled as it passes through the indoor heat exchanger (80) and supplied to the indoor space.

[0043] <Heater operation> Heating operation is the operation of heating the air in the indoor space. In heating operation, the four-way switching valve (22) is set to the second state and the three-way valve (34) is set to the first state, and the compressor (14), outdoor fan (12), pump (32), and cross-flow fan (70) are operated. During 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). Then, the air transported by the cross-flow fan (70) is heated as it passes through the indoor heat exchanger (80) and supplied to the indoor space.

[0044] -Detailed configuration of the indoor unit- The configuration of the indoor unit (7) will be explained in detail with reference to Figures 2 to 6. In the following explanation, the terms "up," "down," "left," "right," "front," and "back" refer to the directions indicated by the arrows in Figures 2, 3, 5, and 6. The front-back direction corresponds to the first direction. The left-right direction corresponds to the second direction. The up-down direction corresponds to the third direction.

[0045] The indoor unit (7) shown in Figure 2 is configured to be wall-mounted. The indoor unit (7) is installed at the bottom of the wall inside the room. As shown in Figure 3, the indoor unit (7) comprises 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, "outer circumferential surface (70a) of the cross-flow fan (70)" means the cylindrical surface represented by the rotational trajectory of the outer end of the blade (76) of the cross-flow fan (70) in the radial direction.

[0046] <Casing> The casing (50) is formed in the shape of a hollow box. Specifically, the casing (50) has its longitudinal direction in the left-right direction and its short direction in the front-back direction, and is a relatively thin rectangular parallelepiped in the front-back direction. The casing (50) houses the cross-flow fan (70), the indoor heat exchanger (80), the air filter (82), and the fan guard (84). The casing (50) is constructed by combining metal plates or resin plates.

[0047] 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) each 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 side of the casing (50). The left plate (50c) constitutes the left side 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).

[0048] The casing (50) has an intake port (52), an outlet port (54), and an air passage (56). The intake port (52) is an opening for drawing in air from the indoor space. The intake port (52) is provided as a first intake port (52a) and a second intake port (52b). The first intake port (52a) is formed in a horizontally elongated rectangular shape on the lower front part of the casing (50), that is, on the lower part of the front plate (50e). The width of the first intake port (52a) in the left-right direction is wider than the width of the first intake port (52a) in the up-down direction. The direction perpendicular to the opening surface of the first intake port (52a) corresponds to the front-back direction.

[0049] A suction grille (90) is provided at the first suction port (52a). The suction grille (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 they may be attached directly to the periphery of the first suction port (52a). The second suction port (52b) is formed in a horizontally elongated rectangular shape at the front of the lower surface of the casing (50), that is, at the front of the bottom plate (50b). 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.

[0050] The air outlet (54) is an opening for blowing the heat-exchanged air into the room space. The air outlet (54) is formed in a horizontally elongated 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-back direction. The air outlet (54) is provided with a plurality of flaps (55). The plurality of flaps (55) extend in the left-right direction and are spaced apart from each other in the front-back direction. The flaps (55) are air direction adjustment plates that change the direction of the air blown out from the air outlet (54), and are attached to the casing (50) so as to be rotatable around an axis that extends in the left-right direction.

[0051] The air passage (56) is a passage that connects the intake port (52) and the outlet port (54), and is provided inside the casing (50). Inside the casing (50), a passage forming section (60) is provided. The passage forming section (60) forms a scroll shape on the intake port (52) side of the air passage (56) and houses the cross-flow fan (70). The air passage (56) formed by the passage forming section (60) is open forward and downward at the bottom and extends forward upward from the scroll-shaped portion. The passage forming section (60) is composed of a stabilizer (62) and a rear guider (64). The stabilizer (62) and the rear guider (64) are metal parts or resin molded products, respectively.

[0052] The stabilizer (62) is attached to the front plate (50e) and positioned above the cross-flow fan (70). The stabilizer (62) divides the air passage (56) formed by the passage forming section (60) into an intake space (56a) and a discharge space (56b). The intake space (56a) is the space through which air is drawn from the intake port (52) to the cross-flow fan (70), and is provided between the intake port (52) and the cross-flow fan (70). The discharge space (56b) is the space through which air is discharged from the cross-flow fan (70) toward the outlet (54), and is provided downstream of the cross-flow fan (70).

[0053] 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 the lower rear side of the stabilizer (62) and protrudes diagonally downward toward the rear side of the front lower surface of the stabilizer (62). The tongue portion (63) corresponds to the area above the rotation axis (Ra) of the cross-flow fan (70). The tongue portion (63) is provided on one side in the vertical direction relative to the cross-flow fan (70), in this example on the upper side, along a part of the outer circumference of the cross-flow fan (70), and extends in the left-right direction to correspond to the entire length of the cross-flow fan (70).

[0054] The tongue portion (63) is located near the outer circumferential surface (70a) of the cross-flow fan (70) and faces the outer circumferential surface (70a) with a gap in between. The tongue portion (63) constitutes the part 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-to-back direction to the second region (A2) of the intake port (52), which will be described later, and extends in the vertical direction to correspond to the portion of the cross-flow fan (70) on the intake port (52) side.

[0055] The rear guide (64) is attached to the rear plate (50f) and the bottom plate (50b) and is positioned behind the cross-flow fan (70). More precisely, the rear guide (64) is positioned 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 guide (64) constitutes the lower and rear walls of the air passage (56). The rear guide (64) extends along the outer circumference of the cross-flow fan (70). The rear guide (64) has a portion that is closest to the outer circumferential surface (70a) of the cross-flow fan (70) at its lower end and curves so as it extends upward, it gradually moves away from the outer circumferential surface of the cross-flow fan (70).

[0056] The rear guide (64) constitutes the water receiving section (65). The water receiving section (65) is located at the upper end of the rear guide (64) and is positioned to cover the lower end of the indoor heat exchanger (80) from below. The water receiving section (65) is a drain pan that receives water and receives condensed water generated in the air inside the indoor heat exchanger (80) or in its vicinity within the casing (50). The indoor unit (7) is provided with a drainage mechanism, although not shown, to discharge the water in the water receiving section to the outside. For example, the drainage mechanism consists of a drain pump and a drain pipe.

[0057] <Cross-flow fan> The cross-flow fan (70) is housed in the air passage (56). The cross-flow fan (70) is provided with its rotation axis (Ra) oriented in the left-right direction and is positioned at the bottom of the air passage (56) formed by the passage forming section (60). Specifically, the cross-flow fan (70) is positioned on the back side of the intake grille (90) so as to correspond to the first intake port (52a) in the front-rear direction. The outer circumferential surface (70a) of the cross-flow fan (70) is located near the intake grille (90). The shortest distance between the outer circumferential surface (70a) of the cross-flow fan (70) and the intake grille (90) is 5 mm or more and 30 mm or less.

[0058] The cross-flow fan (70) rotates around a rotation axis (Ra) that extends along the left-right direction. In this example, the direction of rotation of the cross-flow fan (70) is such that the blades (76) of the cross-flow fan (70) move from top to bottom on the intake port (52) side and from bottom to top on the discharge side (see Figure 7). The cross-flow fan (70) comprises a fan rotor (72) as shown in Figure 4 and a motor (not shown). The fan rotor (72) has a plurality of partition plates (74), a plurality of blades (76), and two shaft portions (78).

[0059] Multiple partition plates (74) are each formed in a disc shape and are spaced apart from one another in the left-right direction so that their centers lie on the same straight line. The straight line connecting the centers of the multiple partition plates (74) coincides with the axis of rotation (Ra) of the fan rotor (72). Two shaft portions (78) are formed 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 shaft portion (78) is rotatably supported by the left plate (50c) or right plate (50d) of the casing (50), or by a support shaft member fixed to the casing (50). The other shaft portion (78) is connected to a motor.

[0060] Multiple blades (76) are provided between each of the multiple partition plates (74) and are stretched across the outer circumference of a pair of opposing partition plates (74). The numerous blades (76) are spaced apart from each other in the circumferential direction of the fan rotor (72). Furthermore, each blade (76) is curved so as to bulge outwards in the opposite direction to the rotation direction (indicated by the arrow in Figure 4) in the circumferential direction of the fan rotor (72), and is arranged in a position that is inclined with respect to the radial direction of the fan rotor (72), with the inner portion of the blades being positioned on the opposite side of the rotation direction in the circumferential direction of the fan rotor (72).

[0061] <Indoor heat exchanger> As shown in Figure 3, the indoor heat exchanger (80) is positioned downstream of the cross-flow fan (70) in the air passage (56). The indoor heat exchanger (80) is, for example, a fin-and-tube type heat exchanger. The indoor heat exchanger (80) is fixed to the casing (50) and the passage forming section (60) so that substantially all of the air flowing through the air passage (56) passes through it. In this example, the indoor heat exchanger (80) is installed above the passage forming section (60) in a forward-tilting position so as to protrude upward and forward. The lower part of the indoor heat exchanger (80) is located behind the casing (50) and is supported by the water receiving section (65). The upper part of the indoor heat exchanger (80) is supported by the front plate (50e) of the casing (50).

[0062] <Air filter> The air filter (82) is positioned upstream of the cross-flow fan (70) in the air passage (56) near the intake port (52). The air filter (82) is mounted in the casing (50) or passage forming section (60) so that substantially all of the air drawn into the cross-flow fan (70) passes through. The air filter (82) is located between the first intake port (52a) and the cross-flow fan (70), and between the second intake port (52b) and the cross-flow fan (70). The air filter (82) is provided on the rear side of the intake grille (90).

[0063] The air filter (82), together with the passage forming section (60), encloses the cross-flow fan (70). In this example, the air filter (82) is formed in an L-shape to correspond continuously to the first intake port (52a) and the second intake port (52b). The air filter (82) may also be provided individually for the first intake port (52a) and the second intake port (52b). The air filter (82) collects dust in the air that is drawn into the air passage (56) from the intake port (52). For example, the air filter (82) is made of a metal mesh made of stainless steel or the like.

[0064] <Fanguard> The fan guard (84) is a protective barrier that prevents human body parts such as fingers or foreign objects from entering the air passage (56) from the intake port (52). The fan guard (84) is positioned further inside the air passage (56) than the air filter (82) and is located 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) consists of a plurality of rods (86). Each of the rods (86) extends in the left-right direction and is arranged at intervals from one another along the rear of the air filter (82). Each rod (86) is made of, for example, metal and is fixed to the casing (50).

[0065] <Inlet, Inlet Grille> As shown in Figures 5 and 6, the vertical width of the first intake port (52a) is greater than the diameter of the cross-flow fan (70). This ensures that the airflow rate drawn into the air passage (56) by the operation of the cross-flow fan (70) is maintained. 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 cross-flow 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).

[0066] The first region (A1) is the 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-back view. The upper part of the first region (A1) corresponds to the rotating part of the cross-flow fan (70) toward the suction port (52). The second region (A2) is the region located on the tongue (63) side in the vertical direction relative to the first region (A1) at the first suction port (52a). In this example, the second region (A2) is located above the first region (A1). The third region (A3) is the region located on the opposite side of the tongue (63) side in the vertical direction relative to the first region (A1) at the first suction port (52a). In this example, the third region (A3) is located below the first region (A1).

[0067] Each of the multiple guide plates (92) forming the intake 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 certain orientation, as shown by dot hatching in Figure 5. In this specification, "orientation of the guide plate (92)" corresponds to the width direction of the guide plate (92) (the direction in which the second straight line (L2), described later, extends), and is the direction in which the air passing through the intake grille (90) is guided. The multiple guide plates (92) include guide plates (92) that are arranged in different orientations from each other. The multiple 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).

[0068] 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 intake port (52). The third guide plate (92c) is the guide plate (92) located in the first region (A1) above the first guide plate (92a), that is, 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, multiple second guide plates (92b), third guide plates (92c), and fourth guide plates (92d) are provided.

[0069] Whether the guide plate (92) is placed in the first region (A1), the second region (A2), or the third region (A3) is determined by which region the center (C2) of the guide plate (92) is located in a cross section perpendicular to the left-right direction of the indoor unit (7) (hereinafter referred to as the symmetric cross section). If the center (C2) of the guide plate (92) is located in the first region (A1), then the guide plate (92) is the first guide plate (92a), the third guide plate (92c), or the fourth guide plate (92d). If the center (C2) of the guide plate (92) is located in the second region (A2), then the guide plate (92) is the second guide plate (92b). If the center (C2) of the guide plate (92) is located in the third region (A3), then the guide plate (92) is the fourth guide plate (92d). In this specification, "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 symmetric cross-section of the guide plate (92).

[0070] In the following, in the symmetric cross-section of the indoor unit (7), the straight line passing through the center of the guide plate (92) and the center (C2) of the cross-flow fan (70) is defined as the first straight line (L1). In the symmetric cross-section of the indoor unit (7), the straight line passing through the upstream end (93a) located on the upstream side in the airflow direction of the guide plate (92) and the downstream end (93b) located on the downstream side is defined as the second straight line (L2). Furthermore, the point closest to the first intake port (52a) among the intersections of the outer surface (70a) of the cross-flow fan (70) and the first straight line (L1) is defined as the first intersection point (P1). The point closest to the first intake port (52a) among the intersections of the outer surface (70a) of the cross-flow fan (70) and the second straight line (L2) is defined as the second intersection point (P2).

[0071] The first guide plate (92a), some of the second guide plates (92b), each third guide plate (92c), and each fourth guide plate (92d) are provided with the second straight line (L2) inclined with respect to the front-rear direction. In this specification, when the second straight line (L2) of a guide plate (92) is inclined upward with respect to a virtual straight line (L3) corresponding to the front-rear direction, that inclination angle is indicated by adding "up". Also, when the second straight line (L2) of a guide plate (92) is inclined downward with respect to a virtual straight line (L3) corresponding to the front-rear direction, that inclination angle is indicated by adding "down".

[0072] The first guide plate (92a) is installed in an inclined direction with respect to the front-rear direction such that the second intersection (P2) is located behind the first intersection in the rotational direction of the cross-flow fan (70). The first guide plate (92a) is inclined with respect to the front-rear direction such that the second straight line (L2) extends upward toward the cross-flow fan (70). The first inclination angle θ1 that the second straight line (L2) of the first guide plate (92a) makes with respect to the front-rear direction satisfies 0° < θ1 ≤ 60°. In this example, the first inclination angle θ1 is approximately 30° upward.

[0073] Each fourth guide plate (92d), like the first guide plate (92a), is inclined with respect to the front-rear direction such that the second straight line (L2) extends upward toward the cross-flow fan (70). In this example, each fourth guide plate (92d) is installed in the same orientation as the first guide plate (92a). That is, the fourth inclination angle θ4 that the second straight line (L2) of each fourth guide plate (92d) makes with respect to the front-rear direction satisfies 0° < θ1 ≤ 60°, just like the first inclination angle θ1. In this example, the fourth inclination angle θ4 is the same as the first inclination angle θ1, and is approximately 30° upward.

[0074] Each second guide plate (92b) is installed in a orientation such that the second straight line (L2) intersects with the outer surface (70a) of the cross-flow fan (70). Each second guide plate (92b) is inclined with respect to the front-rear direction such that the second straight line (L2) extends downward toward the cross-flow fan (70). In this example, each second guide plate (92b) is installed in an orientation inclined with respect to the front-rear direction such that the second intersection point (P2) is located on the rear side of the first intersection point (P1) in the rotational direction of the cross-flow fan (70). The second inclination angle θ2 that the second straight line (L2) of each second guide plate (92b) makes with respect to the front-rear direction satisfies 0° ≤ θ2 ≤ 45°. In this example, the second inclination angle θ2 is approximately 30° downwards.

[0075] Each third guide plate (92c) is positioned such that the third inclination angle θ3 that the second straight line (L2) makes with respect to the front-rear direction is between the first inclination angle θ1 and the second inclination angle θ2. The third inclination angle θ3 differs depending on the vertical position of the third guide plate (92c). The third inclination angle θ3 of the multiple third guide plates (92c) differs in stages from bottom to top, such that the orientation of the third guide plate (92c) approaches that of the second guide plate (92b) from that of the first guide plate (92a). The multiple third guide plates (92c) are positioned so that they generally form a radial arrangement as a whole, such that the second straight line (L2) intersects with each other on the cross-flow fan (70) side.

[0076] The third guide plate (92c) closer to the first guide plate (92a) adopts a third inclination angle θ3 smaller than the first inclination angle θ1, and is inclined in the front-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) adopts a third inclination angle θ3 smaller than the second inclination angle θ2, and is inclined in the front-rear direction so that the second straight line (L2) extends downward toward the cross-flow fan (70). In this example, among the multiple third guide plates (92c), the third guide plate (92c) located in the middle in the vertical direction is set in a position where the second straight line (L2) extends straight in the front-rear direction, that is, in a position where the third inclination angle θ3 is 0°.

[0077] When the cross-flow fan (70) rotates, indoor air is drawn in from the intake port (52) through the intake grille (90), air filter (82), and fan guard (84) into the air passage (56). The indoor air drawn in from the intake port (52) into the air passage (56) is guided by multiple guide plates (92) as it passes through the intake grille (90), and flows through the air filter (82) into the intake space (56a) with almost no change in its flow direction. At this time, the airflow guided by the first guide plate (92a) gives a pre-swirling motion to the airflow drawn into the cross-flow fan (70). In addition, the airflow guided by the second guide plate (92b) forms a smooth flow toward the cross-flow fan (70).

[0078] -Airflow performance of the indoor unit- Figure 10 shows the specifications of the guide plate (92) between the indoor unit (7) of the embodiment and the indoor units (7) of comparative examples 1 to 3, and the same airflow (9.45 m³). 3 This shows the rotational speed [rpm] of the cross-flow fan (70) at / min).

[0079] The basic configuration of the indoor unit (7) of the embodiment is the same as that of the embodiment described above, as shown in Figure 6. In the indoor unit (7) of the embodiment, there are 13 guide plates (92), and the thickness of the guide plates (92) is 2.0 mm. Of the 13 guide plates (92), the seven guide plates (92) located on the lower side are the first guide plate (92a) and the fourth guide plate (92d). The orientation of the first guide plate (92a) and the fourth guide plate (92d) is such that the inclination angle (first inclination angle θ1, fourth inclination angle θ4) that the second straight line (L2) makes with respect to the front-rear direction is 30° upward. The two guide plates (92) located on the upper side are the second guide plates (92b). The orientation of the second guide plate (92b) is such that the second inclination angle θ2 is 30° downward.

[0080] The indoor unit (7) of Comparative Example 1 has the same configuration as the indoor unit (7) of the embodiment, except that the number, thickness, and orientation of the guide plates (92) are different. As shown in Figure 7, the indoor unit (7) of Comparative Example 1 has 12 guide plates (92). The thickness of each guide plate (92) is 1.2 mm. The orientation of all 12 guide plates (92) is such that the second straight line (L2) extends straight in the front-rear direction, and the inclination angle (1st to 4th inclination angles θ1 to θ4) that the second straight line (L2) makes with respect to the front-rear direction is horizontal and 0°.

[0081] The indoor unit (7) of Comparative Example 2 has the same configuration as the indoor unit (7) of the embodiment, except that the orientation of the guide plates (92) is different. As shown in Figure 8, in the indoor unit (7) of Comparative Example 2, the orientation of all 13 guide plates (92) is uniform, such that the inclination angle (1st to 4th inclination angles θ1 to θ4) that the second straight line (L2) makes with respect to the front-rear direction is 30° upward.

[0082] The indoor unit (7) of Comparative Example 3 has the same configuration as the indoor unit (7) of the embodiment, except that the orientation of the guide plates (92) is different. As shown in Figure 9, in the indoor unit (7) of Comparative Example 3, four of the thirteen guide plates (92) located on the lower side are some of the fourth guide plates (92d). The orientation of these some of the fourth guide plates (92d) is such that the fourth inclination angle θ4 is 30° upward. The five guide plates (92) located on the upper side are the second guide plates (92b) and some of the third guide plates (92c). The orientation of these second guide plates (92b) and some of the third guide plates (92c) is such that the inclination angle (second inclination angle θ2, third inclination angle θ3) that the second straight line (L2) makes with respect to the front-rear direction is 30° downward. 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, similar to the third guide plate (92c) in the above embodiment. The orientation of the other guide plates (92) is such that the inclination angle (second inclination angle θ2, third inclination angle θ3) that the lower guide plate (92) makes with respect to the front-to-back direction of the second straight line (L2) approaches the direction where it is 30° upwards and approaches the direction where it is 30° downwards.

[0083] As shown in Figure 10, in the indoor unit (7) of the embodiment, the same airflow (9.45 m³) 3 The rotational speed of the cross-flow fan (70) relative to the airflow rate (9.45 m³ / min) is lower compared to the indoor units (7) of Comparative Examples 1-3. Thus, according to the indoor unit (7) of the embodiment, even with a relatively lower rotational speed of the cross-flow fan (70), the same airflow rate (9.45 m³ / min) can be achieved. 3 This can be achieved ( / min). This is because the first guide plate (92a) pre-swirls the airflow drawn into the cross-flow fan (70), increasing the pressure in the cross-flow fan (70), while the air that is guided by the second guide plate (92b) as it passes through the intake port (52) and drawn into the air passage (56) flows smoothly to the cross-flow fan (70), thereby reducing the losses of the cross-flow fan (70). As a result, the energy efficiency of the indoor unit (7) can be improved.

[0084] -Features of the Embodiment- In the indoor unit (7) of this embodiment, the intake port (52) has a first region (A1) that corresponds to the cross-flow fan (70) when viewed in the front-to-back direction, and a second region (A2) located on the tongue (63) side in the vertical direction relative to the first region (A1). Of the multiple guide plates (92) provided in the intake port (52), the first guide plate (92a) located closest to the center (C1) of the cross-flow fan (70) in the first region (A1) is provided in an inclined direction with respect to the front-to-back direction. The orientation of the first guide plate (92a) is such that, in the symmetrical cross section of the indoor unit (7), the second intersection (P2) between the outer surface (70a) of the cross-flow fan (70) and the second straight line (L2), which is closer to the intake port (52), is positioned behind the first intersection (P1) between the outer surface (70a) of the cross-flow fan (70) and the first straight line (L1), which is closer to the intake port (52), in the direction of rotation of the cross-flow fan (70). This first guide plate (92a) imparts a pre-swirl to the airflow drawn into the cross-flow fan (70) in the opposite direction to the rotation of the cross-flow fan (70), thereby increasing the pressure of the cross-flow fan (70).

[0085] As shown in Figure 15, if all guide plates (92) are uniformly provided 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 multiple guide plates (92) will flow outward in the radial direction of the cross-flow fan (70) before being drawn into the cross-flow fan (70). As a result, the path of the air guided by the guide plate (92) near the upper edge of the intake port (52) to the cross-flow fan (70) becomes longer, leading to losses in the cross-flow fan (70). In contrast, in the indoor unit (7) of this embodiment, the second guide plate (92b) is provided in a different orientation from the first guide plate (92a). The orientation of the second guide plate (92b) is such that it forms a second inclination angle θ2 on the opposite side of the front-rear direction from the side on which the first guide plate (92a) forms a first inclination angle θ1. According to this, compared to the case where the second guide plate (92b) takes the same orientation as the first guide plate (92a), as shown in Figure 11, the air that is guided by the second guide plate (92b) as it passes through the intake port (52) and drawn into the casing (50) can be smoothly directed to the cross-flow fan (70). This reduces the losses of the cross-flow fan (70).

[0086] In the indoor unit (7) of this embodiment, a third guide plate (92c) located between the first guide plate (92a) and the second guide plate (92b) among the multiple guide plates (92) is provided in a different orientation 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 that the second straight line (L2) makes with respect to the front-rear direction takes an angle between the first inclination angle θ1 and the second inclination angle θ2. This third guide plate (92c) suppresses a large change in the orientation of the multiple guide plates (92) between the first guide plate (92a) and the second guide plate (92b). This makes it possible to mitigate collisions between airflows guided by adjacent guide plates (92) when passing through the intake port (52). This is advantageous in reducing losses of the cross-flow fan (70).

[0087] In the indoor unit (7) of this embodiment, the suction space (56a) within the casing (50) corresponds to the second region (A2) in the front-to-back direction and expands to correspond to the portion of the cross-flow fan (70) on the intake port (52) side in the vertical direction. Including such a suction space (56a) within the casing (50) allows for a wider opening area of ​​the intake port (52). However, when the second guide plate (92b) takes the same orientation as the first guide plate (92a), the air passing through the intake port (52) is guided by the second guide plate (92b) toward the radially outward direction of the cross-flow fan (70), which tends to increase the losses of the cross-flow fan (70). Therefore, the technology of this disclosure is particularly effective in the indoor unit (7).

[0088] In the indoor unit (7) of this embodiment, the first inclination angle θ1 made by the second straight line (L2) of the first guide plate (92a) with respect to the front-rear direction is greater than 0° and 60° or less. When the first inclination angle θ1 is 60° or less, it is possible to appropriately impart a pre-swirling motion to the airflow drawn into the cross-flow fan (70) while suppressing excessive resistance (airflow resistance) as the air passes through the intake port (52).

[0089] In the indoor unit (7) of this embodiment, the second guide plate (92b) is inclined in the opposite direction to the first guide plate (92a) with respect to the front-rear direction, and the second inclination angle θ2 made by the second straight line (L2) of the second guide plate (92b) with respect to the front-rear direction is 0° or more and 45° or less. When the second inclination angle θ2 is 45° or less, the air passing through the intake port (52) can be guided by the second guide plate (92b) toward the cross-flow fan (70) while suppressing excessive resistance (ventilation resistance) when the air passes through the intake port (52).

[0090] The air conditioning system (1) in this embodiment includes an indoor unit (7). The indoor unit (7) can reduce the losses of the cross-flow fan (70). Therefore, the energy-saving performance of the air conditioning system (1) can be improved.

[0091] -First variation- As shown in Figure 12, in the indoor unit (7), each of the multiple fourth guide plates (92d) is positioned such that the fourth inclination angle θ4 is greater than the first inclination angle θ1. The further the fourth guide plate (92d) is from the first guide plate (92a), the larger the fourth inclination angle θ4 formed by the fourth guide plate (92d). That is, the fourth inclination angle θ4 of the multiple fourth guide plates (92d) increases in steps from the top to the bottom. The fourth inclination angle θ4 of each fourth guide plate (92d) satisfies 30 < θ4 ≤ 60° and differs from each other by a few degrees. The fourth inclination angle θ4 may be different for all of the fourth guide plates (92d), or it may be the same for only some of the adjacent fourth guide plates (92d), and different for the other fourth guide plates (92d).

[0092] In the indoor unit (7) of this first modified example, each fourth guide plate (92d) is positioned such that its fourth inclination angle θ4 is greater than its first inclination angle θ1. The fourth guide plate (92d) is a guide plate (92) located on the opposite side of the first guide plate (92a) from the second guide plate (92b), and its fourth inclination angle θ4 increases as it moves away from the first guide plate (92a). This fourth guide plate (92d) prevents the orientation of 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 the collision of airflows guided by adjacent guide plates (92) as they pass through the intake port (52). This is advantageous for reducing losses in the cross-flow fan (70).

[0093] -Second variation- As shown in Figure 13, each second guide plate (92b) may be positioned so that its 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 positioned so that the second straight line (L2) extends straight in the front-rear direction, that is, so that its second inclination angle θ2 is 0°. In this case, the third guide plate (92c) closer to the second guide plate (92b) may also be positioned so that its third inclination angle θ3 is 0°. Alternatively, only some of the multiple second guide plates (92b) may be positioned so that their second inclination angle θ2 is 0°.

[0094] The indoor unit (7) of this second modified example also provides the same effects as the embodiment described above. Specifically, the first guide plate (92a) pre-swirls the airflow drawn into the cross-flow fan (70), increasing the pressure in the cross-flow fan (70), while simultaneously allowing the air that is guided by the second guide plate (92b) as it passes through the intake port (52) and drawn into the air passage (56) to flow smoothly to the cross-flow fan (70), thereby reducing losses in the cross-flow fan (70).

[0095] Other embodiments As shown in Figure 14, each second guide plate (92b) may be positioned such that its 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°. To give a specific example, while the first inclination angle θ1 of the first guide plate (92a) is about 30° upwards, the second inclination angle θ2 of each second guide plate (92b) is about 10° upwards. The same effects as in the above embodiment can be obtained with such a configuration as well.

[0096] In the indoor unit (7) with the above configuration, the third guide plate (92c) closer to the second guide plate (92b) may also be positioned so that its third inclination angle θ3 is the same as the second inclination angle θ2. Alternatively, some of the second guide plates (92b) may be positioned so that their second inclination angle θ2 is greater than 0° and smaller than the first inclination angle θ1 of the first guide plate (92a) (for example, so that it is approximately 10° upwards).

[0097] The suction port (52) formed in the casing (50) may consist only of a first suction port (52a). For example, in the indoor unit (7) of the above embodiment, the second suction port (52b) may be omitted. The suction port (52) may have only a first region (A1) and a second region (A2), and may not have a third region (A3).

[0098] The formation positions of the intake port (52) and outlet port (54) in the casing (50) and the configuration of the air passage (56) can be arbitrarily changed. For example, in the indoor unit (7) of the above embodiment, the positions of the intake port (52) and outlet port (54) may be reversed. That is, the intake port (52) may be formed on the upper surface of the casing (50), and the outlet port (54) may be formed on the lower front surface of the casing (50).

[0099] The air conditioning unit (1) may be configured as a heating-only unit capable of performing only heating operations, without a four-way switching valve (22) in the refrigerant circuit (10). In this case, the indoor unit (7) may constitute, for example, a fan convector. Alternatively, the air conditioning unit (1) may be configured as a cooling-only unit capable of performing only cooling operations.

[0100] The air conditioning system (1) does not necessarily have to include a 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 inside the indoor heat exchanger (80). The indoor heat exchanger (80) is configured to exchange heat between the refrigerant flowing inside and the indoor air.

[0101] A floor heating system may be connected to the heating, cooling, and hot water supply system that constitutes the air conditioning unit (1). In this case, the floor heating system may be configured to use hot water stored in the water storage tank (40) to provide floor heating. A solar power generation system may also be connected to the heating, cooling, and hot water supply system. In this case, the system may be configured to use the electricity generated by the solar power generation system to heat the water in the water storage tank (40).

[0102] The indoor unit (7) may be positioned on the front side of the ceiling surface and suspended from the ceiling surface. The indoor unit (7) may be positioned on the back side of the ceiling surface and suspended from the ceiling beams. The indoor unit (7) may also be floor-standing.

[0103] The air conditioning system (1) may be equipped with multiple indoor units (7). Furthermore, the space to which the air conditioning system (1) provides cooling and heating is not limited to indoor spaces. The target space may be a warehouse or other storage space, or a factory space.

[0104] The heat exchange unit according to this 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 within a casing and causes pre-swirl in the airflow drawn into the cross-flow fan by a guide plate provided at the intake port of the casing.

[0105] While embodiments and variations have been described above, it will be understood that a variety of modifications to the form and details are possible without departing from the spirit and scope of the claims. Furthermore, these embodiments and variations may be combined or substituted as appropriate, as long as they do not impair the functions covered by this disclosure.

[0106] Furthermore, the designations "First," "Second," "Third," etc., in the specification and claims are used to distinguish between the terms to which these designations are attached, and do not limit the number or order of such terms. [Industrial applicability]

[0107] As described above, this disclosure is useful for heat exchange units and air conditioning systems. [Explanation of Symbols]

[0108] A1 1st area A2 2nd area C1 Crossflow Fan Center Center of the C2 guide plate L1 1st straight line L2 2nd straight line P1 1st intersection P2 2nd intersection Ra rotation axis 1. Air conditioning system 7. Indoor unit (heat exchange unit) 50 Casing 52 Inlet 54 Air 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 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) housed in the aforementioned air passage (56), The air passage (56) includes a heat exchanger (80) located downstream of the cross-flow fan (70), The cross-flow fan (70) is positioned at a location 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. The casing (50) has tongue portions (63) that constitute the wall surface of the air passage (56), which are provided along a part of the outer circumference of the cross-flow fan (70) on one side in a third direction perpendicular to the first and second directions with respect to the cross-flow fan (70). The intake port (52) has a first region (A1) that overlaps with the cross-flow fan (70) in the first view, and a second region (A2) located on the tongue portion (63) side in the third direction relative to the first region (A1), The suction port (52) is provided with a plurality of guide plates (92) that extend in the second direction and are spaced apart from each other in the third direction. The plurality of guide plates (92) include a first guide plate (92a) located closest to the 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, The 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 the first straight line (L1), The straight line passing through the upstream end (93a) located on the upstream side and the downstream end (93b) located on the downstream side in the airflow direction of the guide plate (92) is defined as the second straight line (L2). The first intersection point (P1) is defined as the point closest to the intake port (52) among the intersection points of the outer surface (70a) of the cross-flow fan (70) and the first straight line (L1). If we define the second intersection point (P2) as the point closest to the intake port (52) among the intersection points of the outer surface (70a) of the cross-flow fan (70) and the second straight line (L2), The first guide plate (92a) is provided in an inclined direction 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 rotational direction of the cross-flow fan (70), The second guide plate (92b) is provided 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 such that 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. Heat exchange unit.

2. In the heat exchange unit according to claim 1, The plurality of guide plates (92) each have 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 provided in such a orientation 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 an angle between the first inclination angle and the second inclination angle. Heat exchange unit.

3. In the heat exchange unit according to claim 1, The air passage (56) includes a suction space (56a) provided between the suction port (52) and the cross-flow fan (70). The suction space (56a) corresponds to the second region (A2) in the first direction and extends to correspond to the portion of the cross-flow fan (70) on the suction port (52) side in the third direction. Heat exchange unit.

4. In the heat exchange unit according to claim 1, The third direction corresponds to the vertical direction, The cross-flow fan (70) rotates such that the blades (76) of the cross-flow fan (70) move from top to bottom on the intake port (52) side. The first guide plate (92a) is inclined with respect to the first direction such that the second straight line (L2) extends upward toward the cross-flow fan (70), The second guide plate (92b) is positioned above the first guide plate (92a), and is inclined with respect to the first direction such that the second straight line (L2) extends downward toward the cross-flow fan (70), or the second straight line (L2) is positioned parallel to the first direction. Heat exchange unit.

5. In the heat exchange unit according to claim 1, The first inclination angle θ1 satisfies 0° < θ1 ≤ 60°. Heat exchange unit.

6. In the heat exchange unit according to claim 1, The second guide plate (92b) is positioned such that it forms the second inclination angle 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. The second inclination angle θ2 satisfies 0° ≤ θ2 ≤ 45°. Heat exchange unit.

7. In the heat exchange unit according to claim 1, The plurality of guide plates (92) have a plurality of fourth guide plates (92d) arranged on the opposite side from the second guide plate (92b) with respect to the first guide plate (92a), Each of the plurality of fourth guide plates (92d) is provided in a direction in which the fourth inclination angle that the second straight line (L2) of the fourth guide plate (92d) makes with respect to the first direction is greater than the first inclination angle. The fourth inclination angle increases as the fourth guide plate (92d) that forms the fourth inclination angle moves away from the first guide plate (92a). Heat exchange unit.

8. A heat exchange unit (7) according to any one of claims 1 to 7, Air conditioning system.

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