Indoor unit of a heat pump

Abstract

An indoor unit of a heat pump comprising a refrigerant circuit, wherein the indoor unit comprises: a housing (10) having a back (16) configured to be mounted on a wall and a front (18) opposite the back (16); a heat exchanger (30) accommodated in the housing (10); a pipe connection section (52) fluidly connected to the heat exchanger (30) at a side (46) of the heat exchanger (30) and configured to connect the heat exchanger (30) to the refrigerant circuit of the heat pump; a fan for introducing an air flow through the heat exchanger (30), wherein heat is exchanged between a refrigerant flowing through the heat exchanger (30) and the air flow; and a refrigerant leakage detection sensor (60) for detecting a refrigerant leakage in the indoor unit, the refrigerant leakage detection sensor (60) being accommodated in the housing, wherein the refrigerant leakage detection sensor (60) is positioned next to the heat exchanger (30) and in front of the pipe connection section (52) in a front view of the indoor unit and between the front (18) of the housing (10) and the pipe connection section (52) in a side view of the indoor unit.

Description

Technical Field

[0001] This disclosure relates to indoor units of heat pumps, particularly wall-mounted indoor units that include a refrigerant leak detection sensor. Background Technology

[0002] For example, such a wall-mounted indoor unit is disclosed in WO 2019 / 138529 A1. The disclosed indoor unit includes a heat exchanger housed in a casing and a pipe connection section fluidly connected to the heat exchanger on one side and configured to connect the heat exchanger to a refrigerant circuit of a heat pump. A refrigerant leak detection sensor is also disclosed, housed in the casing for detecting refrigerant leaks in the indoor unit. In WO 2019 / 138529 A1, the refrigerant leak detection sensor is attached to the refrigerant pipe of the pipe connection section to enable immediate detection of refrigerant leaks.

[0003] During operation, the surface temperature of the refrigerant pipes at the pipe connection section can vary significantly, for example, from -30°C to +80°C. Therefore, relatively robust sensors, which are typically expensive, are required. Furthermore, temperature variations reduce the sensor's lifespan and adversely affect its accuracy.

[0004] Furthermore, if the refrigerant leak detection sensor is positioned close to or even in contact with the refrigerant line at the pipe connection, the sensor itself may have a temperature equal to or below the dew point, for example, after a defrosting operation. Therefore, condensation may form on the sensor surface. This necessitates waterproofing specifications, which increases the sensor's cost.

[0005] Additionally, our aim is to locate refrigerant leak detection sensors to enable rapid detection of refrigerant leaks, regardless of where they occur within the indoor unit. This is particularly suitable for refrigerants with a density higher than air, such as R32.

[0006] In view of the aforementioned problems, the object of this disclosure is to provide an indoor unit that allows the use of relatively inexpensive refrigerant leak detection sensors while still providing good and rapid detection accuracy that is substantially independent of the location of the refrigerant leak within the indoor unit. Summary of the Invention

[0007] This objective is achieved by the indoor unit of the heat pump as defined in claim 1. Further embodiments are defined in the dependent claims.

[0008] According to a first aspect, an indoor unit of a heat pump including a refrigerant circuit is proposed. In its simplest configuration, the refrigerant circuit may include: a heat source heat exchanger (e.g., an outdoor heat exchanger), an expansion mechanism (e.g., an expansion valve), a utilization side heat exchanger (e.g., an indoor heat exchanger), and a compressor connected via refrigerant pipes. The refrigerant circuit may be filled with R32 as the refrigerant. The indoor unit of the first aspect includes a housing having a back portion configured to be mounted on a wall and a front portion opposite the back portion. Additionally, the housing may have a bottom, a top, and opposing side walls. A heat exchanger (either an indoor heat exchanger or a utilization side heat exchanger of the heat pump) is housed within the housing. The heat exchanger may include multiple portions comprising a front portion facing the front of the indoor unit and a rear portion facing the back of the indoor unit. The heat exchanger may have opposing sides, a top, a bottom, a front, and a back. The heat exchanger is connected to the refrigerant circuit of the heat pump via a pipe connection segment fluidly connected to one side of the heat exchanger. This side of the heat exchanger may face one of the opposing sides (side walls) of the housing. In other words, the pipe connection section can be positioned between one side of the heat exchanger and one side (sidewall) of the housing. A fan is provided to introduce airflow through the heat exchanger, wherein heat is exchanged between the refrigerant flowing through the heat exchanger and the airflow introduced by the fan. Furthermore, the indoor unit includes a refrigerant leak detection sensor for detecting refrigerant leaks in the indoor unit, which is housed within the housing. In this first aspect, the refrigerant leak detection sensor is positioned next to (adjacent to) the heat exchanger and in front of (facing the pipe connection section or the front of the pipe connection section) in the front view of the indoor unit, and positioned between the front of the housing and the pipe connection section in the side view of the indoor unit. In other words, the refrigerant leak detection sensor is positioned in the space defined by one side of the heat exchanger, one side (sidewall) of the housing, the front of the housing, and the front of the refrigerant pipe of the pipe connection section. In this context, the front of the refrigerant pipe of the pipe connection section is defined as the minimum envelope surrounding (all) the refrigerant pipe of the pipe connection section. The front of the housing can be a front cover or a portion of the front cover. The back of the housing can be the main body or a portion of the main body.

[0009] According to the first aspect, the refrigerant leak detection sensor does not contact the refrigerant pipe at the pipe connection section. As a result, the refrigerant leak detection sensor is positioned in an area where significant temperature changes are unlikely. Therefore, a less expensive temperature sensor that provides high accuracy and reliable leak detection can be used. Furthermore, the positioning of the refrigerant leak detection sensor in the first aspect allows for reliable leak detection substantially independently of its location within the housing of the indoor unit.

[0010] According to the second aspect, the refrigerant leak detection sensor is positioned closer to the bottom of the heat exchanger than to the top of the heat exchanger. Preferably, the refrigerant leak detection sensor is positioned in the lower third of the housing of the indoor unit.

[0011] The second aspect of the configuration also enables reliable detection of refrigerants with a higher density than air (such as R32), which are likely to accumulate in the bottom area of ​​the indoor unit. Additionally, it allows for faster detection of refrigerant leaks occurring on the opposite side of the heat exchanger (i.e., the side opposite the pipe connection section). Refrigerant leaking from the side will accumulate in the bottom area of ​​the unit and spread throughout the entire bottom area over time. Eventually, the refrigerant will reach the side with the pipe connection section, where it can still be detected by the refrigerant leak detection sensor.

[0012] According to the third aspect, the indoor unit also includes an electrical box housed within the casing, adjacent to the piping connection section of the heat exchanger. A refrigerant leak detection sensor is positioned in the front view of the indoor unit between the heat exchanger and the electrical box, specifically in the space between the side of the heat exchanger and the facing side of the electrical box. The electrical box may, for example, house a controller for controlling the operation of the indoor unit. The controller may be electrically connected to the main controller of the heat pump.

[0013] According to the third aspect, the space where leaked refrigerant might accumulate is limited to the space between the electrical box and the heat exchanger on the side facing the electrical box. Due to the limited space, the concentration of leaked refrigerant increases rapidly, and the detection accuracy and speed are improved. Furthermore, the refrigerant leak detection sensor is positioned close to the electrical box, allowing for a shorter cable length to connect the sensor to, for example, a controller contained within the electrical box.

[0014] According to the fourth aspect, the refrigerant leak detection sensor includes: a sensor housing, a circuit board surrounded by the sensor housing, and a gas sensor mounted on the circuit board. The gas sensor has a housing, a refrigerant receiving area at an end of the housing that allows gaseous refrigerant to enter the housing, and a sensing element within the housing, wherein the housing protrudes through an opening in the side wall of the sensor housing in the direction toward a pipe connection section, such that the refrigerant receiving area is located outside the sensor housing.

[0015] This configuration places the main body of the gas sensor inside the sensor housing, protecting it from moisture. Furthermore, the heat generated by the gas sensor during operation is almost entirely contained within the sensor housing, resulting in a so-called "thermal capsule" or "thermal pocket" covering the gas sensor (particularly the circuit board). The advantage of this "thermal capsule" or "thermal pocket" is that the temperature near the sensor becomes higher, thus reducing humidity around the sensor. However, since the refrigerant receiving area is outside the sensor housing, it means direct contact with the surrounding air, thus improving detection sensitivity and reliability.

[0016] In this context, the term "refrigerant receiving area" in relation to a "gas sensor" defines, in this disclosure, a region or surface of the gas sensor housing (particularly the end or top of the housing) that allows refrigerant (particularly gaseous refrigerant) to penetrate the receiving area and thereby enter the housing of the gas sensor. In this way, the refrigerant receiving area enables, on the one hand, gaseous refrigerant to enter the housing and thereby reach the sensing element preferably disposed inside the housing, and on the other hand, the refrigerant receiving area prevents moisture and water (particularly condensate) from entering the housing. In other words, the refrigerant receiving area, preferably a membrane, is impermeable to liquids (such as moisture and water) but permeable to air. Alternatively, the refrigerant receiving area may comprise an upper layer made of a silica filter and a lower layer made of activated carbon.

[0017] Furthermore, the term "sensing element" in this disclosure defines any device (gas sensor) capable of detecting physical parameters or resistance such as temperature, pressure, or humidity, and in particular the presence of gaseous refrigerant.

[0018] According to the fifth aspect, the sensor housing is mounted in the indoor unit via a support structure. In addition to supporting and mounting the sensor housing in the indoor unit, the support structure is configured to further restrict the space around the refrigerant leak detection sensor facing the front of the indoor unit, particularly the refrigerant receiving area. According to the fifth aspect, the support structure may include a first shielding structure having a first shield extending upward from an open sidewall of the sensor housing and, in a front view, covering a refrigerant pipe extending from the heat exchanger side.

[0019] As a result, leaking refrigerant can be prevented from bypassing the refrigerant leak detection sensor, and the concentration of leaking refrigerant around the sensor (especially in the refrigerant receiving area) can be increased, leading to more accurate and faster detection. In other words, the first shield encloses the space defined between the side of the heat exchanger and the side of the housing (sidewall) / electrical box relative to the front. Additionally, the first shield allows the sensor housing to be shielded from water droplets (condensate from the refrigerant lines) dispersed by the airflow introduced by the fan.

[0020] According to the sixth aspect, the refrigerant leak detection sensor includes a cable that passes through an opening in the top wall of the sensor housing and connects to a circuit board. The cable extends from the top wall of the sensor housing along the front side of a first shield to an electrical box housed within the housing, such that the cable is shielded relative to the refrigerant pipe by the first shield.

[0021] Therefore, the first shield prevents water droplets (condensate from the refrigerant lines) dispersed by the airflow introduced by the fan from reaching the cable. Thus, the risk of water droplets flowing along the cable and entering the sensor housing through the opening in the top wall is reduced.

[0022] According to the seventh aspect, the first shielding structure has a second shield that extends from the side edge of the first shield toward the front surface of the heat exchanger.

[0023] The second baffle can extend / lengthen / enlarge the side surface of the heat exchanger to limit the space where leaked refrigerant may accumulate. In other words, the second baffle works with the heat exchanger to limit the space within which the refrigerant leak detection sensor is located. Therefore, the concentration of leaking refrigerant can be increased, and the accuracy and speed of detection can be improved.

[0024] According to the eighth aspect, the second baffle has an inclined edge that faces the front surface of the heat exchanger and corresponds to the shape of the front surface of the heat exchanger.

[0025] The first baffle extends substantially vertically. Since the front of the heat exchanger can be tilted relative to the vertical direction, the surface of the first baffle facing the front of the heat exchanger can be positioned away from the front of the heat exchanger in the top portion of the first baffle, thus forming a gap between the surface of the first baffle and the front of the heat exchanger. To close this gap, a second baffle is provided, which has an edge facing the front surface of the heat exchanger that is also tilted relative to the vertical direction. Therefore, any leaking refrigerant is prevented from escaping through this gap, thereby improving detection accuracy.

[0026] According to the ninth aspect, the first shielding structure has a third shield extending from the lower end of the first shield toward the pipe connection section and beyond the refrigerant receiving area, such that the end of the third shield facing the pipe connection section is positioned closer to the pipe connection section than the refrigerant receiving area. In other words, the third shield forms a roof-like shoulder protecting the refrigerant receiving area, wherein the leading edge of the third shield is located at a distance from the refrigerant receiving area.

[0027] Therefore, any water droplets captured by the first shield and flowing along the first shield to the refrigerant receiving area are prevented from falling onto the gas sensor, especially its refrigerant receiving area.

[0028] According to the tenth aspect, the support structure has a second shielding structure having a fourth shielding plate that extends downward relative to the sidewall of the sensor housing with an opening.

[0029] Therefore, if a leak occurs at a relatively low position in the space between the side of the heat exchanger and the side wall of the housing / electrical box, the leaking refrigerant is prevented from escaping below the refrigerant leak detection sensor. This ensures reliable detection of leaks in this area.

[0030] According to the tenth aspect, the fourth baffle has a bottom side portion that is inclined toward the pipe connection section and corresponds to the shape of the front surface of the heat exchanger in the side view.

[0031] This configuration restricts the space between the side of the heat exchanger, the front of the pipe connection section, the side of the shell (side wall), and the side of the electrical box to the lower part, thereby increasing the accuracy and speed of detection.

[0032] According to the twelfth aspect, the support structure has a fifth shield that extends from the fourth shield toward the pipe connection section.

[0033] Like the second baffle, the fifth baffle enables the sealing of the gap between the fourth baffle and the side of the housing (side wall) / electrical box, thereby preventing leaked refrigerant from escaping through the gap.

[0034] According to the thirteenth aspect, the support structure has at least one through hole, said at least one through hole for allowing gaseous refrigerant to pass through the support structure from the side of the support structure facing the front of the indoor unit and reach the refrigerant receiving area of ​​the refrigerant leak detection sensor.

[0035] Because the support structure, and particularly the first and / or second shielding structures, enclose the space between the sides of the heat exchanger, the front of the pipe connection section, and the sides of the housing (sidewalls) / electrical box relative to the front, refrigerant potentially leaking on the opposite side or at the front of the heat exchanger may not easily reach the refrigerant leak detection sensor, particularly the refrigerant receiving area of ​​the gas sensor. To also allow for rapid and reliable detection of those leaks, through-holes in the support structure allow gaseous refrigerant to enter the space and thus reach the refrigerant receiving area.

[0036] According to the fourteenth aspect, the circuit board includes an evaluation unit configured to evaluate a signal received from a sensing element, make an inference about refrigerant leakage based on the received signal, and output a (digital) leakage signal to the controller of the indoor unit.

[0037] This digital communication of the leaked signal enables better electromagnetic noise immunity.

[0038] According to the fifteenth aspect, the housing includes a body and a front cover, the body including a back and the front cover including a front, the front cover being removable and the refrigerant leak detection sensor being accessible by removing the front cover.

[0039] This configuration enables the refrigerant leak detection sensor to be easy to maintain. Attached Figure Description

[0040] Figure 1 A front perspective view of the indoor unit according to an embodiment is shown.

[0041] Figure 2A It shows Figure 1 A front perspective view of the interior unit with the front cover removed.

[0042] Figure 2B It shows Figure 1 A front view of the interior unit with the front cover removed.

[0043] Figure 3 It shows Figure 2B A top view showing part of the electrical box of the indoor unit removed.

[0044] Figure 4 It shows Figure 2B Left side view of the interior unit.

[0045] Figure 5 It shows Figure 2A The enlarged portion of the front 3D view shows the electrical box of the indoor unit being removed.

[0046] Figure 6 It shows Figure 3A magnified top view of the interior unit.

[0047] Figure 7 The previous 3D diagram showed an isolated refrigerant leak detection sensor.

[0048] Figure 8 The following 3D diagram shows Figure 7 A refrigerant leak detection sensor.

[0049] Figure 9 A refrigerant leak detection sensor is shown in cross-sectional view. Detailed Implementation

[0050] Preferred embodiments of the interior unit according to this disclosure are depicted in the corresponding figures. Modifications to the features can be combined to form other embodiments. The interior unit described below is to be understood as exemplary and not restrictive. The features of the embodiments described below can also be used to further characterize the interior unit as defined in the claims.

[0051] like Figures 1 to 6 As shown, the indoor unit includes a housing 10. In this embodiment, the housing 10 includes a body 12 and a front cover 14. The body 12 includes at least one back 16, and the front cover 14 includes at least one front portion 18. Only in... Figure 1 The front cover 14 is shown in the image. Figure 3 , Figure 4 as well as Figure 6 A partial cross-sectional view of the front portion 18 of the front cover 14 is shown. Thus, the housing 10 includes a back 16 for mounting the housing 10 (particularly the body 12) to a wall (not shown). The front portion 18 of the housing 10 is positioned opposite the back 16. The housing 10 also includes a bottom 20 and a top 22, as well as opposing sides 24 (first side 24) and 26 (second side 26), which may be partially formed by the front cover 14 and / or the body 12.

[0052] The heat exchanger 30, which is part of the refrigerant circuit of the heat pump, is housed in the housing 10. The heat exchanger 30 may be formed from separate parts connected to each other. In this embodiment, the heat exchanger 30 includes two front portions 32 (first front portion) and 34 (second front portion) and a rear portion 36. However, depending on the configuration of the indoor unit, the heat exchanger 30 may include fewer or more portions.

[0053] The heat exchanger 30 includes a top end 38 defined by the highest point or a corresponding portion of the heat exchanger 30, and a bottom end 40 defined by the lowest point or a corresponding portion of the heat exchanger 30. The heat exchanger 30 also has a front surface 42, which in this embodiment is formed by the front surfaces of the first front side portion 32 and the second front side portion 34 pointing towards the front portion 18 of the housing 10. The heat exchanger 30 also has a rear surface 44 formed by the rear surface of the rear side portion 36 facing the back side 16 of the housing 10. Additionally, the heat exchanger 30 includes opposing side surfaces, namely, a first side 46 and a second side 48.

[0054] The heat exchanger 30 may also include multiple refrigerant pipes passing through multiple fins arranged in rows from the first side 46 to the second side 48. Two refrigerant pipes are fluidly connected to each other via U-shaped bends 50 formed at the first side 46 and the second side 48 of the heat exchanger 30, respectively. To fluidly connect the refrigerant pipes to the refrigerant circuit of the heat pump, a pipe connection section 52 is positioned at the first side 46 of the heat exchanger 30. The pipe connection section 52 may, for example, include headers connected to the refrigerant pipes 58 of the heat exchanger 30. The pipe connection section 52 may also include an indoor expansion valve, a muffler, etc., for the refrigerant circuit.

[0055] In addition, the fan (in) Figure 4 Only the axis of rotation 54 is visible within the housing 10, thereby introducing an airflow through the heat exchanger 30. Specifically, the airflow is introduced into the housing 10 through the intake region 28, passes through the heat exchanger 30, and is discharged via the exhaust region 29. During operation, heat is exchanged between the refrigerant (such as R32) flowing through the refrigerant pipes of the heat exchanger 30 and the airflow introduced by the fan 54 and passing through the heat exchanger 30.

[0056] Furthermore, the electrical box 56 is housed within the housing 10. The electrical box 56 may include a controller for controlling the operation of the indoor unit. The controller may be electrically connected to the main control circuit of the heat pump. In the illustrated embodiment, the electrical box 56 is positioned between the first side 46 of the heat exchanger 30 and the first side 24 of the housing 10.

[0057] The illustrated indoor unit also includes a refrigerant leak detection sensor 60 housed within the housing 10. The purpose of the refrigerant leak detection sensor is to detect refrigerant leaks in the indoor unit, particularly refrigerant leaks within the housing 10 of the indoor unit. (Refer to...) Figures 7 to 9 A more detailed description of the refrigerant leak detection sensor 60.

[0058] The refrigerant leak detection sensor 60 includes a sensor housing 62.

[0059] Sensor housing 62 includes housing body 102 and housing cover 104 removably attached to housing body 102 (see Figure 9 The sensor housing 62 has opposing sidewalls 106 and 108 (which may be referred to as front wall 106 and rear wall 108), a top wall 110, a bottom wall 112, and opposing sidewalls 114 and 116. The sensor housing 62 is surrounded by a thermal insulator 118.

[0060] Circuit board 64 (see) Figure 9 The gas sensor 66 is surrounded by a sensor housing 62. The gas sensor 66 is mounted on a circuit board. The gas sensor 66 has a sensor housing 68 (see...). Figure 9 The sensor housing 68 includes a refrigerant receiving area 70 located at one end of the sensor housing 68. The refrigerant receiving area 70 allows gaseous refrigerant to enter the sensor housing 68 and thereby reach the sensing element (not shown) located inside the sensor housing 68.

[0061] The gas sensor 66 (particularly the sensor housing 68) protrudes into or through an opening 72 provided in or through the (vertical) side wall (rear wall) 108 of the sensor housing 62 (particularly the housing body 102). A refrigerant receiving area 70 is positioned outside the sensor housing 62 or within the opening 72, allowing gaseous refrigerant to reach the refrigerant receiving area 70 and enter the sensor housing 68. In this context, the sensor housing 68 protrudes (extends) in a direction toward the pipe connection section (i.e., toward the back of the indoor unit). Alternatively, a sensing element (not shown) can be positioned within the sensor housing 68.

[0062] Cable 65 is connected to circuit board 64. Cable 65 extends through opening 120 in top wall 110 of sensor housing 62 (particularly housing body 102). Cable 65 leads to electrical box 56 and connects to controller (not shown).

[0063] The circuit board 64 includes an evaluation unit configured to evaluate signals received from sensing elements, make inferences about refrigerant leakage based on the received signals, and output a digital leakage signal to the controller of the indoor unit.

[0064] In the illustrated embodiment, the support structure 74 is used to mount the refrigerant leak detection sensor 60. The support structure may be integrally formed with the sensor housing 62. Alternatively, the sensor housing 62 may be formed separately and attached to the support structure 74. In the illustrated embodiment, the housing body 102 of the sensor housing 62 and the support structure 74 are integrally formed as a single piece.

[0065] The support structure 74 can be removably mounted to the front surface 42 of the heat exchanger 30 via, for example, the mounting portion 76.

[0066] The support structure 74 also includes a first shielding structure 78 and a second shielding structure 90.

[0067] The first shielding structure 78 includes a first shield 80, a second shield 82, and a third shield 84.

[0068] The first shield 80 extends upward from the rear wall 108 of the sensor housing 62. In an embodiment, the first shield 80 may extend substantially vertically. The first shield 80 may be configured to cover, in a front view, the refrigerant pipe 58 extending from the side 46 of the heat exchanger 30 of the pipe connection section 52.

[0069] A cable 65 extending from the top wall 110 of the sensor housing 62 extends along the front side / front surface 81 of the first shield 80. The front side / front surface 81 of the first shield 80 faces away from the pipe connection section 52 and towards the front portion 18 of the housing 10. The cable 65 can be attached to the front side / front surface 81 of the first shield 80 by, for example, a cable clip 86. Thus, the cable 65 is shielded relative to the refrigerant pipe 58 / pipe connection section 52 by the first shield 80.

[0070] The second baffle 82 extends from the side edge 83 of the first baffle 80. The side edge 83 is located on the side facing the first side 46 of the heat exchanger 30. The second baffle 82 protrudes substantially perpendicularly to the first baffle 80 toward the front surface 42 of the heat exchanger 30. The lower edge 85 facing the front surface 42 of the heat exchanger 30 is shaped (inclined) to correspond to the shape of the front surface 42 of the heat exchanger 30. In the illustrated embodiment, the second baffle 82 has a triangular shape, one side of which corresponds to the inclined edge 85 of the second baffle 82.

[0071] The third baffle 84 extends from the lower end 87 of the first baffle 80 toward the pipe connection section 52 and beyond the refrigerant receiving area 70 or even beyond the side wall 108 of the sensor housing 62. Therefore, the end or free edge 88 of the third baffle 84 facing the pipe connection section 52 is positioned closer to the pipe connection section 52 than the refrigerant receiving area 70 or even the side wall 108 of the sensor housing 62.

[0072] The second shielding structure 90 has a fourth shield 92 and a fifth shield 96.

[0073] The fourth shield 92 extends downward relative to the sidewall 108 of the sensor housing 62, which has an opening 72. In the illustrated embodiment, the fourth shield 92 extends substantially vertically downward.

[0074] The fourth baffle 92 has a bottom side portion 94 that is inclined toward the pipe connection section 52 and corresponds to the shape of the front surface 42 of the heat exchanger 30 in the side view.

[0075] The fifth baffle 96 extends from the fourth baffle 92 toward the pipe connection section 52. In this embodiment, the fifth baffle 96 protrudes substantially perpendicularly to the fourth baffle 92 toward the back 16.

[0076] The support structure 74 also has a through hole 98 for allowing gaseous refrigerant to pass through the support structure 74 from the side of the support structure 74 facing the front part 18 of the housing 10 / indoor unit and reach the refrigerant receiving area 70 of the refrigerant leak detection sensor 60.

[0077] Refrigerant leaks are most likely to occur at the brazed joints or fittings of the refrigerant pipe. Therefore, pipe connection 52 is prone to refrigerant leaks. For this reason, the refrigerant leak detection sensor 60 is positioned adjacent to the pipe connection 52. However, instead of attaching the refrigerant leak detection sensor 60 to the refrigerant pipe 58 of the pipe connection 52, the refrigerant leak detection sensor 60 is positioned at a certain distance forward from the refrigerant pipe 58.

[0078] Specifically, the refrigerant leak detection sensor 60 (more particularly, its refrigerant receiving area 70) is positioned in a space defined in a first direction (x-axis) by the first side 46 of the heat exchanger 30 and the first side 24 of the housing 10, or more particularly in this embodiment by the sidewall of the electrical box 56 facing the first side 46 of the heat exchanger 30. This space is defined in a second direction (z-axis) by the front portion 18 of the housing 10 (see the inner or rear surface of the front cover 14) and the pipe connection section 52. In this context, the minimum envelope covering the pipe connection section 52 restricts the space at its rear. As a result, the refrigerant leak detection sensor 60 is positioned next to the heat exchanger 30 and in front of the pipe connection section 52 in the front view of the indoor unit, and in the side view of the indoor unit, it is positioned between the front portion 18 of the housing 10 and the pipe connection section 52.

[0079] In this embodiment, the space is further restricted in the second direction (y-axis) by the support structure 74 (particularly the first shield 80 to the fifth shield 96). Therefore, if a refrigerant leak occurs in the pipe connection section 52, the concentration of the leaking refrigerant and the environment of the refrigerant leak detection sensor 60 (particularly its refrigerant receiving area 70) can be kept high, thereby improving detection speed and accuracy.

[0080] If a refrigerant leak occurs between opposite sides 46 and 48 of the heat exchanger 30, or at the second side 48 of the heat exchanger 30, the refrigerant can still reach the refrigerant leak detection sensor 60, and more specifically, its refrigerant receiving area 70, within a sufficiently short time. In some cases, the refrigerant can flow along the rear surface 44 of the heat exchanger 30 toward the pipe connection section 52, thereby entering the space where the refrigerant leak detection sensor 60 (refrigerant receiving area 70) is located. In another case, the refrigerant can flow along the front surface 42 of the heat exchanger 30 and then through the through-hole 98 of the support structure 74, thereby entering the space where the refrigerant leak detection sensor 60 (refrigerant receiving area 70) is located. Therefore, in this case, it is also possible to detect refrigerant leaks quickly and accurately.

[0081] Furthermore, the refrigerant leak detection sensor 60 (refrigerant receiving area 70) is positioned closer to the bottom 14 of the heat exchanger 30 than to the top 38 of the heat exchanger 30. Specifically, if a refrigerant with a density higher than air (such as R32) is used, leaked refrigerant tends to accumulate on the lower portion of the housing 10. Therefore, this positioning allows for more reliable and faster detection of such refrigerant leaks. Moreover, even small leaks can be detected.

[0082] Furthermore, the first shield 80 shields the cable 65 and thus protects it from water. During operation, condensation can form on the refrigerant pipe 58 in the pipe connection section 52. Due to the airflow introduced by the fan, the condensation may escape from the refrigerant pipe 58. The first shield 80 will capture these water droplets and prevent them from reaching the cable 65. As a result, water can not flow along the cable 65 and thus enter the sensor housing 62 through the opening 120. Therefore, the lifespan of the refrigerant leak detection sensor 60 can be improved.

[0083] The third baffle 84 prevents water droplets captured by the first baffle 80 from reaching the gas sensor 66, and in particular, the refrigerant receiving area 70. Specifically, the refrigerant receiving area 70 is spring-backed relative to the free edge 85 of the third baffle 84. As water droplets fall from the free edge 84, they fall towards the bottom of the housing 10 at a distance from the refrigerant receiving area 70.

[0084] As a result, the first shielding structure 78 has a dual function: to seal the space in the event of a refrigerant leak in order to increase the refrigerant concentration near the refrigerant leak detection sensor 60 (refrigerant receiving area 70), and to protect the refrigerant leak detection sensor 60 from water droplets.

[0085] Furthermore, as mentioned earlier, the refrigerant detection sensor 60 is positioned at a certain distance from the refrigerant pipe 58 at the pipe connection section 52. Therefore, compared to a refrigerant detection sensor 60 positioned close to or even attached to the refrigerant pipe, the refrigerant detection sensor 60 involves a smaller temperature change. The smaller temperature change also results in less condensation forming on the refrigerant detection sensor 60.

[0086] Furthermore, due to the first shielding structure 78 and the second shielding structure 90, the airflow around the refrigerant leak detection sensor 60 (particularly the refrigerant receiving area 70) can be reduced. Therefore, the amount of moisture in the air flowing around the refrigerant leak detection sensor 60 can also be reduced. Therefore, the refrigerant leak detection sensor 60 does not need to be waterproof.

[0087] [List of Labels]

[0088] 10. Shell

[0089] 12 main body

[0090] 14 Front Cover

[0091] 16 Back

[0092] 18 Front

[0093] 20 Bottom

[0094] 22 Top

[0095] 24 First side

[0096] 26 Second side

[0097] 28 Inhalation Zone

[0098] 29 Discharge Area

[0099] 30 Heat Exchanger

[0100] 32 First front section

[0101] 34 Second anterior part

[0102] 36 Rear section

[0103] 38 Top

[0104] 40 bottom

[0105] 42 Front surface

[0106] 44 Rear Surface

[0107] 46 First side

[0108] 48 Second side

[0109] 50 U-shaped bend

[0110] 52 Pipe connection section

[0111] 54 Fan rotation axis

[0112] 56 Electrical Box

[0113] 58 Refrigerant pipe

[0114] 60 Refrigerant Leak Detection Sensor

[0115] 62 Sensor Housing

[0116] 64 circuit boards

[0117] 65 cable

[0118] 66 Gas Sensor

[0119] 68 Sensor Housing

[0120] 70 Refrigerant Receiving Area

[0121] 72 Opening

[0122] 74 Support Structure

[0123] 76 Installation Part

[0124] 78 First Shielding Structure

[0125] 80 First shield

[0126] 81 Front

[0127] 82 Second shield

[0128] 83 Side edge

[0129] 84 Third shield

[0130] 85 Slanted edge

[0131] 86 Cable clamps

[0132] 87 Lower end

[0133] 88 Free Edge

[0134] 90 Second shielding structure

[0135] 92 Fourth shield

[0136] 94 Bottom side section

[0137] 96 Fifth shield

[0138] 98 through hole

[0139] 102 Outer shell body

[0140] 104 covers

[0141] 106 Side wall (anterior wall)

[0142] 108 Side wall (rear wall)

[0143] 110 Top Wall

[0144] 112 bottom wall

[0145] 114 Sidewall

[0146] 116 Sidewall

[0147] 118 Insulators

[0148] 120 opening

[0149] [List of References]

[0150] [Patent Literature]

[0151] [PTL 1]WO 2019 / 138529 A1

Claims

1. An indoor unit of a heat pump including a refrigerant circuit, wherein, The indoor unit includes: A housing (10) having a back (16) configured to be mounted on a wall and a front (18) opposite to the back (16). A heat exchanger (30) is housed in the housing (10); A pipe connection section (52) is fluidly connected to the heat exchanger (30) on one side (46) of the heat exchanger (30), and the pipe connection section is configured to connect the heat exchanger (30) to the refrigerant circuit of the heat pump. A fan is used to introduce an airflow through the heat exchanger (30), wherein heat will be exchanged between the refrigerant flowing through the heat exchanger (30) and the airflow; A refrigerant leak detection sensor (60) is provided, which is used to detect refrigerant leaks in the indoor unit and is housed in the housing. The refrigerant leak detection sensor (60) is positioned next to the heat exchanger (30) and in front of the pipe connection section (52) in the front view of the indoor unit, and positioned between the front part (18) of the housing (10) and the pipe connection section (52) in the side view of the indoor unit. The indoor unit also includes an electrical box (56), which is housed in the housing (10) and adjacent to the pipe connection section (52) of the heat exchanger (30). The refrigerant leak detection sensor (60) is positioned in the front view of the indoor unit between the heat exchanger (30) and the electrical box (56). The refrigerant leak detection sensor (60) includes: a sensor housing (62). The sensor housing (62) is mounted in the indoor unit via a support structure (74), the support structure (74) including a first shielding structure (78) having a first shield (80) extending upward from a side wall (108) of the sensor housing (62) having an opening (72), and covering, in the front view, a refrigerant pipe (58) extending from one side of the heat exchanger (30). The first shielding structure (78) has a second shield (82) that extends from the side edge (83) of the first shield (80) toward the front surface (42) of the heat exchanger (30).

2. The indoor unit according to claim 1, wherein, The refrigerant leak detection sensor (60) is positioned closer to the bottom end (40) of the heat exchanger (30) than to the top end (38) of the heat exchanger (30).

3. The indoor unit according to claim 1 or 2, wherein, The refrigerant leak detection sensor (60) also includes: The circuit board (64) is surrounded by the sensor housing (62); and A gas sensor (66) is mounted on the circuit board (64), the gas sensor (66) having a sensor housing (68), a refrigerant receiving area (70) at the end of the sensor housing (68) allowing gaseous refrigerant to enter the sensor housing (68), and a sensing element in the sensor housing (68), wherein the sensor housing (68) protrudes through the opening (72) in the side wall (108) of the sensor housing (62) in the direction toward the pipe connection section (52), so that the refrigerant receiving area (70) is arranged outside the sensor housing (62).

4. The indoor unit according to claim 3, wherein, The refrigerant leak detection sensor (60) includes a cable (65) that passes through an opening (120) in the top wall (110) of the sensor housing (62) and connects to the circuit board (64). The cable (65) extends from the top wall (110) of the sensor housing (62) along the front side (81) of the first shield (80) to an electrical box (56) housed in the housing (10), such that the cable (65) is shielded relative to the refrigerant pipe (58) through the first shield (80).

5. The indoor unit according to claim 1, wherein, The second baffle (82) has an inclined edge (85) facing the front surface (42) of the heat exchanger (30) and corresponding to the shape of the front surface (42) of the heat exchanger (30).

6. The indoor unit according to claim 4, wherein, The first shielding structure (78) has a third shield (84) that extends from the lower end (87) of the first shield (80) toward the pipe connection section (52) and beyond the refrigerant receiving area (70) such that the end (88) of the third shield (84) facing the pipe connection section (52) is positioned closer to the pipe connection section (52) than the refrigerant receiving area (70).

7. The indoor unit according to claim 4, wherein, The support structure (74) has a second shielding structure (90) with a fourth shield (92) extending downward from the sidewall (108) of the sensor housing (62) having the opening (72).

8. The indoor unit according to claim 7, wherein, The fourth shield (92) has a bottom side portion (94) that is inclined toward the pipe connection section (52) and corresponds in a side view to the shape of the front surface (42) of the heat exchanger (30).

9. The indoor unit according to claim 7, wherein, The support structure (74) has a fifth shield (96) that extends from the fourth shield (92) toward the pipe connection section (52).

10. The indoor unit according to claim 4, wherein, The support structure (74) has at least one through hole (98) for allowing gaseous refrigerant to pass through the support structure (74) from the side of the support structure (74) facing the front (18) of the indoor unit and reach the refrigerant receiving area (70) of the refrigerant leak detection sensor (60).

11. The indoor unit according to claim 3, wherein, The circuit board (64) includes an evaluation unit configured to evaluate a signal received from a sensing element, make an inference about refrigerant leakage based on the received signal, and output a leakage signal to the controller of the indoor unit.

12. The indoor unit according to claim 1 or 2, wherein, The housing (10) includes a body (12) and a front cover (14), the body (12) including at least the back (16), the front cover (14) including at least the front (18), the front cover (14) being removable, and the refrigerant leak detection sensor (60) being accessible when the front cover (14) is removed.

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