Ceiling mounted air conditioning unit for a heat pump comprising a refrigerant circuit and having a refrigerant leakage sensor

Abstract

The present disclosure relates to a ceiling mounted air conditioner indoor unit (1) for a heat pump comprising a refrigerant circuit, the indoor unit comprising: a casing (2) comprising an air inlet (2a) and at least one air outlet (2b); a drain pan (3) located at a bottom portion of the casing (2) having a first rim (3a) and a second rim (3b); a heat exchanger (4) being part of the refrigerant circuit and arranged above the drain pan (3) to accumulate water dripping from the heat exchanger (3) in the drain pan (3); a fan (5) housed in the casing (2) to draw air from the air inlet (2a) and discharge it from the at least one air outlet (2b) through the heat exchanger (4); a bell mouth (6) located at the air inlet (2a) and used to direct the drawn air to the fan (5); and a refrigerant leak detection sensor (7) for detecting a refrigerant leaking from the refrigerant circuit, wherein the refrigerant leak detection sensor (7) is located between an outer surface (8) of the second rim (3b) of the drain pan (3) and an inner surface (9) of the bell mouth (6), wherein the outer surface (8) of the second rim (3b) of the drain pan (3) and the inner surface (9) of the bell mouth (6) face each other.

Description

TECHNICAL FIELD

[0001] The present disclosure relates to a ceiling mounted air conditioning unit for a heat pump comprising a refrigerant circuit. BACKGROUND

[0002] As described in EP3279590A1, generally, in an air conditioning apparatus having a ceiling mounted indoor unit using a refrigerant having a specific gravity greater than air at the time of vaporization, an air intake port and a blow-out port are formed in the indoor unit, which has an indoor fan for sucking indoor air from the air intake port and blowing air-conditioned air from the blow-out port, an air intake temperature sensor, an indoor-side refrigerant circuit for circulating a refrigerant and producing air-conditioned air from the indoor air, and a refrigerant temperature sensor for detecting the temperature of the refrigerant in the indoor-side refrigerant circuit. A control device drives the indoor fan according to the operation mode and / or the detected value of the refrigerant temperature sensor, and detects refrigerant leakage by using a refrigerant gas sensor.

[0003] In EP3279590A1, the refrigerant gas sensor is installed in the air flow path within the indoor unit. The described refrigerant gas sensor uses air sucked from the indoor including the leaked refrigerant. More specifically, in the described indoor unit, the refrigerant having a specific gravity greater than air at the time of vaporization accumulates at the bottom of the indoor space, thus, without operating the indoor fan, it is not possible to reliably detect refrigerant leakage. This problem is mainly caused by the position of the refrigerant gas sensor, i.e. it is mainly caused by the refrigerant gas sensor being located on the outer surface of the bell mouth. Since refrigerant leakage most likely occurs at the pipes of the refrigerant circuit, the distance between the possible leakage location and the refrigerant gas sensor is too large and there are too many obstacles between them, thus, without continuously operating the indoor fan, it is not possible to reliably detect refrigerant leakage.

[0004] Thus, when the indoor fan stops due to reaching the required room temperature, the leaked refrigerant cannot be detected due to the distance between the outlet reached by the leaked refrigerant and the refrigerant sensor. Therefore, in order to overcome the above problem, EP3279590A1 teaches performing a sampling operation to drive the indoor fan to detect refrigerant leakage. Thus, the indoor fan operates even when the air conditioning does not need to operate, which causes a sacrifice in user comfort and an increase in energy consumption. Finally, in case of any mechanical problem that causes the indoor fan to stop functioning, it adversely affects the detection of the leaked refrigerant.

[0005] [CITATION LIST]

[0006] [Patent Literature]

[0007] [Patent Literature 1] EP3279590A1

[0008] [Patent Literature 2] EP2813777A1

[0009] [Patent Literature 3] JP2012-77952A SUMMARY

[0010] In view of the above, it is desirable to provide a ceiling-mounted air-conditioner indoor unit for a heat pump including a refrigerant circuit, which can provide high detection efficiency / accuracy and high detection reliability while avoiding continuous operation of an indoor fan of the indoor unit, thereby reducing energy consumption of the indoor unit.

[0011] This object can be achieved by a ceiling-mounted air-conditioner indoor unit for a heat pump including a refrigerant circuit, which is defined by technical solution one. Embodiments can be found in the dependent technical solutions, the following description and the drawings.

[0012] According to a first aspect of the present disclosure, there is provided a ceiling-mounted air-conditioner indoor unit for a heat pump including a refrigerant circuit, the indoor unit comprising: a casing including an air inlet and at least one air outlet; a drain pan located at a bottom portion of the casing, the drain pan having a first rim (outer peripheral rim) and a second rim (inner peripheral rim); a heat exchanger that is part of the refrigerant circuit and is arranged above the drain pan such that water dripping from the heat exchanger accumulates in the drain pan; a fan housed in the casing to draw air from the air inlet and pass through the heat exchanger to be discharged from the at least one air outlet; a bellmouth located at the air inlet and configured to guide the drawn air to the fan; and a refrigerant leakage detection sensor configured to detect refrigerant leaking from the refrigerant circuit. The refrigerant leakage detection sensor is located between an outer surface of the second rim of the drain pan and an inner surface of the bellmouth, wherein the outer surface of the second rim of the drain pan and the inner surface of the bellmouth face each other.

[0013] In this way, a ceiling-mounted air-conditioner indoor unit can be provided, which can provide improved detection efficiency / accuracy and detection reliability. This is particularly possible because the refrigerant gas sensor is provided at the bellmouth side, i.e. the refrigerant circuit side, where refrigerant leakage is likely to occur.

[0014] Further, since the refrigerant leakage detection sensor is located on the bell mouth, the sensor can be easily contacted from the outside of the indoor unit through the bell mouth, thereby reducing maintenance costs.

[0015] There are different types of ceiling mounted indoor units, for example, the indoor unit included in the present disclosure can have, for example, two air outlets or four air outlets. The type of indoor unit not only differs in the number of outlets, for example, in the design or location of the outlets.

[0016] For example, EP2813777A1 describes a ceiling suspended indoor unit arranged to be suspended from a ceiling surface T (see Figure 11 ). The indoor unit comprises a housing having a cuboid shape, a heat exchanger arranged annularly in the housing, a fan arranged inside the heat exchanger, and a drain pan arranged below the heat exchanger.

[0017] The housing has a rectangular shape in a bottom view. The housing comprises a decorative panel having a suction grille, a top panel, and four corner covers between the decorative panel and the top panel, four upper decorative frames extending in a horizontal direction between the corner covers adjacent to each other, and four lower decorative frames extending in a horizontal direction between the corner covers adjacent to each other.

[0018] A filter is arranged between the suction grille and the fan. Air outlets are arranged in four side walls of the housing, respectively. The upper decorative frames are arranged above the air outlets corresponding thereto. The lower decorative frames are arranged below the air outlets corresponding thereto. A thermal insulator is arranged inside the upper decorative frames along the upper decorative frames and the top panel connected to the upper decorative frames.

[0019] For example, as the heat exchanger, a cross fin type heat exchanger in which a large number of plate-shaped fins are attached to a plurality of heat transfer pipes arranged in parallel to each other in a right angle state can be used. However, the heat exchanger is not limited thereto. The heat exchanger functions as an evaporator during cooling operation and as a condenser during heating operation.

[0020] The drain pan collects drain water generated in the heat exchanger. The drain pan is formed of a foamed resin, such as foamed polystyrene. The drain pan comprises a storage portion located directly below the heat exchanger, which can temporarily store the drain water, and a side end portion located further away from the air outlet side with respect to the storage portion, which forms a part of a lower edge portion of the air outlet. The side end portion is arranged inside (upper side) of the lower decorative frame.

[0021] As the fan, for example, a centrifugal fan (turbo fan), an axial fan, or the like can be used. The fan includes an impeller including a circular hub, a circular shroud having an air guide opening at the center, and a plurality of blades held between the hub and the shroud. A rotation shaft of a fan motor is connected to the hub of the fan. On the lower side of the shroud, a bell mouth for guiding the indoor air to the fan is provided. The bell mouth includes an opening at the center, which is slightly smaller than the opening of the shroud. When the impeller of the fan rotates, the indoor air is sucked into the casing from the suction grating of the decorative panel, and after passing through the heat exchanger, is blown out to the side from the air outlet.

[0022] The air outlet is an opening portion, the shape and size of which are indicated by members forming the casing. Specifically, the air outlet is a substantially rectangular opening portion, which is indicated by the corner covers at both sides of the air outlet, the upper decorative frame, and the lower decorative frame. The air outlet has a shape that is longer in the lateral direction, and the opening size in the horizontal direction is larger than that in the vertical direction. A louver-like member that adjusts the blowing direction of air is provided in the air outlet.

[0023] Further, JP 2012-77952 A describes an indoor unit having two air outlets (see also Figure 12 ). The bottom plate includes a decorative sheet arranged almost horizontally below the filter. The suction port of the indoor unit extends along the edge of the decorative sheet at a position outside the center of the intake port. Further, a guide member is provided in the suction passage, in which the air sucked from the suction port flows to the filter to guide the air sucked from the suction port to a region on the central side of the intake port in the filter.

[0024] According to another aspect of the present disclosure, a header is provided, which fluidly connects the refrigerant piping of the heat exchanger to the refrigerant circuit at a first end of the heat exchanger, wherein the refrigerant leakage detection sensor is arranged in a position close to the first end and the header.

[0025] Further, the heat exchanger can circumferentially surround the inlet opening and can have a second end opposite to the first end, wherein the first end and the second end are directed towards each other, wherein the refrigerant leakage detection sensor can be arranged in the vicinity of the first end and the second end of the heat exchanger.

[0026] In this way, the refrigerant leakage detection sensor can be provided in the vicinity of the refrigerant circuit, in particular in the vicinity of a position where a refrigerant leakage is most likely to occur, thereby eliminating possible obstructions between the refrigerant leakage detection sensor and the refrigerant leakage position(s) that can interfere with the refrigerant leakage detection. Thereby, the reliability of the refrigerant leakage detection sensor can be ensured.

[0027] Further, the refrigerant leakage detection sensor can be a gas sensor having a housing and a refrigerant receiving area at one end of the housing, which allows gaseous refrigerant to enter the housing, wherein the refrigerant receiving area is located below the top of the second rim portion of the drain pan and / or below the top of the inner surface of the bell mouth.

[0028] In this way, the condensed water accumulated in the drain pan will automatically start to drain before the water level approaches to overflow towards the refrigerant leakage detection sensor. Thereby, the sensor can be protected from contact with the condensed water.

[0029] The term "refrigerant receiving area" in connection with "gas sensor" defines in the present disclosure an area or surface of the housing of the gas sensor, in particular of an end or top portion of the housing, which is provided to allow refrigerant, in particular gaseous refrigerant, to penetrate the receiving area and thereby enter the housing of the gas sensor. In this way, on the one hand, the refrigerant receiving area enables gaseous refrigerant to enter the housing and thereby reach the sensing element arranged inside the housing, on the other hand, the refrigerant receiving area is able to prevent water vapor and water, in particular condensed water, from entering the housing. In other words, the refrigerant receiving area, which is preferably a membrane, is impermeable to liquids like water vapor and water, but permeable to air. Alternatively, the refrigerant receiving area can comprise an upper layer made of a silicon dioxide filter and a lower layer made of activated carbon.

[0030] Additionally, the refrigerant leakage detection sensor can further comprise a sensor housing and a circuit board enclosed by the sensor housing, wherein the gas sensor can be mounted on the circuit board and further has a sensing element in the housing, wherein the housing protrudes through an opening of the sensor housing such that the refrigerant receiving area is arranged outside the sensor housing and the sensing element is located inside the sensor housing.

[0031] The term "sensing element" defines in the present disclosure any device (gas sensor) capable of detecting a physical parameter, in particular the presence of gaseous refrigerant, such as temperature, pressure or humidity.

[0032] According to another aspect of the present disclosure, the sensor housing can have a mounting surface mounted to the bell mouth, wherein the opening is provided to a bottom wall of the housing facing the mounting surface and the housing of the gas sensor protrudes towards the mounting surface.

[0033] In a ceiling mounted air conditioning indoor unit, the sensor housing can comprise a leg portion connecting the sensor housing to the mounting surface, thereby forming a passage having opposite open ends between the leg portion, the bottom wall and the bell mouth.

[0034] Furthermore, the first portion of the bottom wall with the opening can be arranged further away from the mounting surface than the second portion of the bottom wall, wherein the first portion of the first wall and the second portion of the first wall are preferably connected by an inclined surface.

[0035] In this way, a sensor housing with a passage or space can be provided, through which air surrounding the sensor housing can easily flow, in particular through the refrigerant receiving area of the gas sensor. Accordingly, gaseous refrigerant can move more freely around the sensor housing and more easily come into contact with the gas sensor. Thus, faster and more efficient detection of leaking refrigerant can be achieved.

[0036] Additionally, the refrigerant leakage detection sensor can be positioned with the first portion facing the inner surface of the bell mouth.

[0037] Positioning the refrigerant leakage detection sensor at the bottom of the inner wall of the bell mouth facilitates detection of refrigerant having a higher density than air and traveling through the lower portion of the indoor unit.

[0038] According to another aspect of the present disclosure, a through-hole can be provided in a wall of the sensor housing facing the outer surface of the second rim portion of the drain pan, and an insulated cable electrically connected to the gas sensor can pass through the through-hole of the wall, in particular in a sealed manner.

[0039] The ceiling-mounted air conditioning indoor unit can further include an electrical box, wherein the refrigerant leakage detection sensor is electrically connected to a component in the electrical box via a sensor cable.

[0040] Furthermore, the housing can have four side walls, the electrical box can be located outside one of the side walls, and the refrigerant leakage detection sensor can be located close to the inside of the side wall where the electrical box is located.

[0041] According to another aspect of the present disclosure, the drain pan can have an air inlet side surface, a sensor cable connecting the refrigerant leakage detection sensor to a component in the electrical box can travel from the refrigerant leakage detection sensor to the air inlet side surface of the drain pan, and along the air inlet side surface of the drain pan to the component in the electrical box.

[0042] Furthermore, a groove extending from the second rim portion of the drain pan to the first rim portion of the drain pan can be provided in the air inlet side surface of the drain pan, and the sensor cable can be accommodated in the groove.

[0043] Furthermore, a seal is preferably also provided in the groove extending between the bell mouth and the drain pan to avoid improper functioning (false suction).

[0044] Because the sensor cable is located in the recess, space can be left below the drain pan, thereby reducing the size of the indoor unit. Furthermore, the recessed location of the sensor cable prevents damage during installation. Attached Figure Description

[0045] This disclosure can be better understood when considered in conjunction with the accompanying drawings and by referring to the following detailed description, thereby making it easier to obtain a more complete understanding of this disclosure and the many advantages that come with it.

[0046] Figure 1 This is a schematic cross-sectional view showing a conventional ceiling-mounted air conditioning indoor unit with a refrigerant leak detection sensor;

[0047] Figure 2 This is a three-dimensional schematic cross-sectional view showing a ceiling-mounted air conditioning indoor unit according to one embodiment of the present disclosure;

[0048] Figure 3 It is shown Figure 2 A three-dimensional schematic diagram showing the location of the leak detection sensor inside the ceiling-mounted air conditioning indoor unit;

[0049] Figure 4 It is shown Figure 2 and Figure 3 A schematic cross-sectional view of a leak detection sensor inside a ceiling-mounted air conditioning indoor unit, as shown.

[0050] Figure 5 This is a three-dimensional schematic diagram illustrating a refrigerant leak detection sensor according to one aspect of the present disclosure;

[0051] Figure 6 yes Figure 5 A schematic cross-sectional view of the refrigerant leak detection sensor shown;

[0052] Figure 7 yes Figure 6 A three-dimensional schematic diagram of the sectional view shown;

[0053] Figure 8 This is a three-dimensional schematic diagram of a refrigerant leak detection sensor according to another aspect of this disclosure.

[0054] Figure 9 This is a three-dimensional schematic diagram showing the cable of a leak detection sensor according to one aspect of the present disclosure;

[0055] Figure 10 It shows the basis Figure 9 A schematic cross-sectional view of the cable wiring for a leak detection sensor as shown.

[0056] Figure 11is a schematic cross-sectional view showing a design of a drain pan and a bell mouth according to an embodiment of the present disclosure in more detail;

[0057] Figure 12 is a schematic cross-sectional view showing a known indoor unit of a ceiling-suspended type provided to be suspended from a ceiling surface;

[0058] Figure 13 is a schematic cross-sectional view showing another known indoor unit of a ceiling-suspended type having two air outlets. DETAILED DESCRIPTION

[0059] Several embodiments of the present disclosure will now be described with reference to the accompanying drawings. It will be apparent to those skilled in the art of air conditioning apparatuses that the following description of embodiments is merely illustrative of the present disclosure and is not intended to limit the present disclosure defined by the appended claims.

[0060] Figure 1 is a schematic illustration showing a cross-sectional view of a conventional ceiling-mounted air conditioning indoor unit having a refrigerant leakage detection sensor. The illustrated indoor unit 40 is a ceiling-mounted indoor unit installed, for example, by being embedded in or suspended from a ceiling CE of a room of an office building or other type of building.

[0061] As Figure 1 illustrated, the conventional ceiling-mounted air conditioning indoor unit includes an indoor heat exchanger 42 serving as a use-side heat exchanger for cooling an indoor space during a cooling operation, an indoor fan 43 serving as a blower for sucking indoor air into the indoor unit 40, where the indoor fan 43 can be a turbo fan, a bell mouth 403, an intake air temperature sensor 46, and a refrigerant gas sensor 45 for detecting leaked gaseous refrigerant when refrigerant circulating through an indoor-side refrigerant circuit leaks into the atmosphere. Further, as Figure 1The conventional ceiling-mounted air-conditioning indoor unit shown has a square shape when viewed from below, and includes four blow-out ports 402 provided along the four sides of the square, and an indoor heat exchanger 42 arranged along the four sides of the square. For example, in a case where a refrigerant gas sensor 45 is attached near the left side of the air inlet port 401, when a leak occurs at a point Pl extending along the right side of the indoor heat exchanger 42 and the indoor fan 43 is stopped, the leaked refrigerant gas flows, for example, in the path of the arrow AR3. Therefore, when the leaked refrigerant gas flows from a point away from the position at which the refrigerant gas sensor 45 is attached, the refrigerant gas sensor 45 is less likely to detect the leaked refrigerant. When the indoor fan 43 is driven, air flows as shown by the double-dot chain line rl, and thus, the refrigerant leaked from the point Pl is captured in the air flow and discharged from the blow-out port 402 through the path shown by the arrow AR4. Therefore, since the position of the refrigerant gas sensor 45 does not necessarily coincide with the flow path of the leaked refrigerant, the reliability of detection of the leaked refrigerant is low.

[0062] Figure 2 is a three-dimensional schematic sectional view showing a ceiling-mounted air-conditioning indoor unit 1 according to one embodiment of the present disclosure. As shown in Figure 2 The ceiling-mounted air-conditioning unit 1 for a heat pump including a refrigerant circuit through which a refrigerant having a specific gravity greater than that of air, preferably when vaporized, flows includes a housing 2 having one air inlet 2a and four blow-out ports 2b, and a drain pan 3 having an outer peripheral portion (first rim portion) 3a and an inner peripheral portion (second rim portion) 3b. The indoor unit 1 further includes a heat exchanger 4 that is part of the refrigerant circuit and is arranged above the drain pan 3 when viewed in Figure 2 The ceiling-mounted air-conditioning unit 1 for a heat pump including a refrigerant circuit through which a refrigerant having a specific gravity greater than that of air, preferably when vaporized, flows includes a housing 2 having one air inlet 2a and four blow-out ports 2b, and a drain pan 3 having an outer peripheral portion (first rim portion) 3a and an inner peripheral portion (second rim portion) 3b. The indoor unit 1 further includes a heat exchanger 4 that is part of the refrigerant circuit and is arranged above the drain pan 3 when viewed in Figure 2 A ceiling-mounted air-conditioning unit in an installed position is shown. Since the drain pan 3 is arranged below the heat exchanger 4, condensed water dripping from the heat exchanger 4 accumulates in the drain pan 3. Additionally, the indoor unit 1 includes a fan 5 provided inside the housing 2 to operate to draw indoor air, in particular, air to be air-conditioned, into the housing 2 through the air inlet 2a and to cause the air to pass through the heat exchanger 3 to exchange heat between the air and the heat exchanger 3, and to blow the air out from the four air outlets 2b. The indoor unit 1 further includes a bell mouth located above the air inlet 2a or forming at least a portion of the air inlet to guide the air drawn in by the fan 5 to the fan. Furthermore, the indoor unit 1 includes a refrigerant leak detection sensor 7 for detecting a refrigerant leaked from the refrigerant circuit. As can be seen, in Figure 2 As can be seen, in Figure 3 and 4It can be seen that the refrigerant leakage detection sensor 7 is located between the outer surface 8 of the inner peripheral portion 3b of the drain pan 3 and the inner surface 9 of the bell mouth 6.

[0063] Figure 3 is a three-dimensional schematic view of the position of the leakage detection sensor 7 within the ceiling-mounted air-conditioning indoor unit 1 shown in Figure 2 . In order to better illustrate the position of the refrigerant leakage detection sensor 7 within the indoor unit 1, the way the section is chosen should ensure that only the bottom part of the indoor unit 1, in particular the drain pan 3 and the bell mouth 6, is shown.

[0064] Figure 3 It is also shown that the heat exchanger 4 has a first end 4a and a second end 4b, in which a header (not shown) fluidly connects the refrigerant piping of the heat exchanger 4 with the refrigerant circuit. The first end 4a and the second end 4a are directed towards each other and are arranged perpendicularly to each other. The refrigerant leakage detection sensor 7 is arranged in the vicinity of the first end 4a and the second end 4b of the heat exchanger 4 and of the header.

[0065] Figure 4 is a schematic cross-sectional view of the leakage detection sensor within the ceiling-mounted air-conditioning indoor unit shown in Figure 2 and Figure 3 . In order to facilitate orientation, Figure 4 the bottom part of the same indoor unit as in Figure 3 is shown. In Figure 4 , the refrigerant leakage detection sensor 7 is shown to be located to the right of the bell mouth 6. As Figure 4 indicated, the refrigerant leakage detection sensor 7 is located between the outer surface 8 of the inner peripheral portion 3b of the drain pan and the inner surface 9 of the bell mouth 6. Here, the inner surface 9 of the bell mouth 6 faces the inner side of the housing 2. In other words, the side facing away from the air inlet 2a. Figure 4 It is also shown that the outer surface 8 of the inner peripheral portion 3b of the drain pan 3 faces the inner surface 9 of the bell mouth 6.

[0066] Figure 4 It is also shown that the refrigerant receiving area of the refrigerant detection sensor 7, which is located at one end of the housing of the refrigerant detection sensor 7 and which allows gaseous refrigerant to enter the housing, is located below the top of the inner peripheral portion 3b of the drain pan 3 and / or below the top of the inner surface 9 of the bell mouth 6. Furthermore, as Figure 4 indicated, the refrigerant leakage detection sensor 7 is positioned with the first portion (which will be explained in more detail with reference to Figures 5 to 7 ) facing the inner surface 9 of the bell mouth 6.

[0067] Figure 5 is a three-dimensional schematic view of the refrigerant leakage detection sensor 7 according to one embodiment of the present application. As Figure 5The refrigerant leakage detection sensor 7 comprises, as shown, a sensor housing 102, a circuit board 103 (shown in Figure 6 ) and a gas sensor 104. The gas sensor 104 has a housing 105, which can be seen in more detail in Figure 6 , and a refrigerant receiving area 106, which is located at an end of the housing 105, for example at the top of the housing 105. The refrigerant receiving area 106 is configured to allow gaseous refrigerant to enter the housing 105. In this way, gaseous refrigerant can enter the housing 105 and thereby reach a sensor element (not shown) located within the housing 105.

[0068] As can also be seen from Figure 5 , the gas sensor 104, in particular the housing 105, protrudes through an opening 107 arranged in the sensor housing 102 in such a way that the refrigerant receiving area 106 is arranged outside the sensor housing 102. On the other hand, the sensor element (not shown) located inside the housing 105 is positioned inside the sensor housing 102.

[0069] Furthermore, in order to better illustrate the position of the gas sensor 104 inside the sensor housing 102, the refrigerant leakage detection sensor 7 is shown in Figure 5 in an inverted manner. This means that a mounting surface 108 for mounting the sensor housing 102 to an external structural element, in particular to the bell mouth 6, is shown at the top of the sensor housing 102. However, in general, the mounting surface 108 is positioned below the sensor housing 102. In other words, in the usual mounting situation of the refrigerant leakage detection sensor 7, the sensor is rotated by 180 degrees as shown in Figure 6 .

[0070] Figure 6 is a schematic sectional view of the refrigerant leakage detection sensor 7 shown in Figure 5 . By providing a sectional view of the sensor 7, it can be seen how the gas sensor 104 and the associated elements are arranged inside the sensor housing 102. As shown in Figure 3 , the sensor housing 102 comprises a main body 116, which in the standard mounting position of the sensor is located at the lower part of the sensor housing 102, and a cover 117. The cover 117 is detachably fixed to the main body 116, wherein the mating surfaces of the main body 116 and the cover 117 overlap in a direction perpendicular to the direction of the fixing. In Figure 6 , the direction of the fixing is vertical, and therefore the mating surfaces of the main body 116 and the cover 117 overlap in the horizontal plane.

[0071] In Figure 6In the shown refrigerant leak detection sensor 7, the mating surface of the cap 117 is arranged outside the mating surface of the body 116, which means that the mating surface of the cap 117 particularly surrounds the mating surface of the body 116 over the entire peripheral extent.

[0072] The circuit board 103 of the gas sensor 104 is arranged inside the sensor housing 102 and parallel to the first wall 102a of the sensor housing 102, particularly to a portion of the first wall 102a which is most distant from the circuit board 103 and parallel to the mounting surface 108. In Figure 6 In the shown standard mounting position of the sensor 7, the first wall 102a is a bottom wall of the sensor housing 102 and located at the mounting surface 108 side. The first wall 2a is provided with an opening 107 through which the housing 105 of the gas sensor 104 protrudes towards the mounting surface 8.

[0073] Furthermore, as Figure 5 and Figure 7 shown, the sensor housing 102 is provided with two legs 109 connecting the sensor housing 102 with the mounting surface 108. In other words, the mounting surface(s) 108 is / are arranged at the end surfaces of the legs 109. The legs 109 are arranged in such a way that a passage with opposite open ends is formed between the two legs 109 and the first wall 102a.

[0074] As can also be seen from Figure 6 and Figure 7 , the sensor housing 102, particularly the body 116, is arranged at a free edge of the outer periphery of the first wall 102a, which is the portion of the body 116 having the lip 110. The lip 110 is formed in such a way that it protrudes towards the mounting surface 108.

[0075] Figure 6 Also shown is the circuit board 103, which is arranged in the sensor housing 102 and parallel to the first wall 102a, particularly to a portion of the first wall 102a which is most distant from the circuit board 103 and parallel to the mounting surface 108, and which is more distant from the first wall 102a than from the third wall 102c, which is Figure 6 In the shown standard mounting position of the sensor 7, the third wall 102a is a top wall opposite the first wall 102a.

[0076] Figure 7 is Figure 6 a three-dimensional view of the cross-sectional view. As can be seen from Figure 7 ( and Figure 6 ), a first portion of the first wall 102a is arranged more distant from the mounting surface 108 than a second portion of the first wall 102a, the first portion of the first wall 102a being Figure 7The first part of the first wall 102a is a left portion of the first wall 102a, and the second part of the first wall 102a is a right portion of the first wall 102a. Figure 7 The first part of the first wall 102a is a left portion of the first wall 102a, and the second part of the first wall 102a is a right portion of the first wall 102a. Figure 7 As shown in Fig. 2, the first part of the first wall 102a and the second part of the first wall 102a are connected by a sloping surface, which is arranged in the middle of the first wall 102a accordingly.

[0077] In the sensor housing 102 of the refrigerant detection sensor 7 shown in Fig. 1, a through hole 112 is provided in a second wall 102b of the sensor housing 102, which is a side wall of the sensor housing 102. The through hole 112 is used for the passage of an insulation cable 113 into the sensor housing 102. Figures 5 to 7 In the embodiment shown in Fig. 2, the insulation cable 113 has a plug 115 at one end inside the sensor housing 102, into which a socket 114 can be inserted, which is mounted on the circuit board 103, so that the insulation cable 113 can be connected to the circuit board 103. Figures 5 to 7

[0078] Figure 8 is a three-dimensional schematic view of a refrigerant leakage detection sensor 1 according to another aspect of the present application. The refrigerant leakage detection sensor 1 shown basically corresponds to the refrigerant leakage detection sensor 1 described with reference to Figure 8 Fig. 1, with the addition of an insulation member 20, which locally thermally insulates the sensor housing 2. Figures 5 to 7

[0079] The insulation member 20 is provided with an opening 21, through which the housing 5 of the gas sensor 4 locally protrudes. In the embodiment shown, it is preferred that the housing 5 protrudes through the opening 21 in a sealed manner, so that the housing 5 can protrude through the opening 7 of the sensor housing 2 in particular not in a sealed manner, but with a gap. The sealing between the insulation member 20 and the housing 5 of the gas sensor 4 can be achieved by a press fit, which is particularly advantageous or easy to achieve in the case that the insulation member 20 is made of an elastic material such as polyethylene foam.

[0080] Figure 9 is a three-dimensional schematic view showing a cable 11 of a leakage detection sensor 7 according to one aspect of the present disclosure. As shown in Figure 9 Fig. 1, the indoor unit 1 comprises an electrical box 10, in which for example a control unit of the indoor unit 1 is accommodated, wherein the refrigerant leakage detection sensor 7 is electrically connected to components within the electrical box 10, for example the control unit, via a sensor cable 11. The sensor cable 11 can be an insulation cable. ​​

[0081] The electrical box 10 is provided outside the four side walls of the casing 2 of the indoor unit 1, and the refrigerant leakage detection sensor 7 is located inside the side wall on which the electrical box 10 is located. In this way, the length of the sensor cable 11 required can be reduced to a minimum.

[0082] Still as Figure 9 shown, the drain pan 3 has an air inlet side surface 3c which, for ease of explanation, faces upwards in Figure 9 the present embodiment. The sensor cable 11 connecting the refrigerant leakage detection sensor 7 to the components in the electrical box 10 runs from the refrigerant leakage detection sensor 7 to the air inlet side surface 3c of the drain pan 3 and along the air inlet side surface 3c of the drain pan 3 up to the components in the electrical box 10. To this end, the air inlet side surface 3c of the drain pan 3 is provided with a groove 12 extending from the inner peripheral portion 3b to the outer peripheral portion 3a thereof, and the sensor cable 11 is accommodated in the groove 12.

[0083] Figure 10 is a schematic cross-sectional view showing the routing of the cable or sensor cable 11 of the leakage detection sensor 7 according to Figure 9 the present embodiment.

[0084] As Figure 9 and Figure 10 shown, the groove 12 provided in the drain pan 3 connects the inner and outer periphery of the drain pan 3. Since the sensor cable 11 is accommodated in the groove 12, a space can be left above the drain pan, thereby reducing the overall height of the indoor unit.

[0085] Figure 10 The area in which the conventional cable 13 is located is also shown in dotted lines, in which the cable is easily damaged due to the sharp edges and high temperatures of the piping of the heat exchanger 4. The routing of the sensor cable 11 proposed by the present disclosure, in particular the accommodation of the sensor cable 11 in the groove 12, can better protect the cable.

[0086] Figure 11 is a schematic cross-sectional view showing the design of the drain pan 3 and the bell mouth 6 in more detail. As Figure 11As shown, the drainage pan 3 and the design of the bell mouth 6 are such that the water condensed on the heat exchanger forms a barrier. The drainage pan 3 is provided with a first barrier (top of the inner peripheral portion 3b) facing the bell mouth 6 and a second barrier (top of the outer peripheral portion 3a) facing the air outlet 2b. The height of the first barrier in the direction of the air inlet is greater than the height of the second barrier in the direction of the air inlet. Thus, in the event of an overflow, the condensed water collected in the drainage pan 3, in particular between the two barriers, flows towards the air outlet and not towards the bell mouth 6. In this way, it is possible to prevent the refrigerant leak detection sensor 7 located at the bell mouth from coming into contact with the condensed water.

[0087] Figure 12 is a schematic cross-sectional view showing a known ceiling-mounted indoor unit suspended from a ceiling surface, Figure 13 is a schematic cross-sectional view showing another known ceiling-mounted indoor unit having two air outlets.

[0088] [LIST OF REFERENCE NUMERALS]

[0089] 1 Ceiling-mounted air conditioning indoor unit

[0090] 2 Housing

[0091] 3 Drainage pan

[0092] 3a Outer peripheral portion

[0093] 3b Inner peripheral portion

[0094] 3c Air inlet side surface

[0095] 4 Heat exchanger

[0096] 5 Fan

[0097] 6 Bell mouth

[0098] 7 Refrigerant leak detection sensor

[0099] 8 Outer surface of the inner peripheral portion

[0100] 9 Inner surface of the bell mouth

[0101] 10 Electrical box

[0102] 11 Sensor cable

[0103] 12 Groove

[0104] 102 Sensor housing

[0105] 102a First wall (bottom wall)

[0106] 102b Second wall (side wall)

[0107] 102c third wall (top wall);

[0108] 103 circuit board (PCB);

[0109] 104 gas sensor;

[0110] 105 (of the gas sensor) housing;

[0111] 106 refrigerant receiving area;

[0112] 107 (in the sensor housing) opening;

[0113] 108 (one or more) mounting surface(s);

[0114] 109 leg;

[0115] 110 (one or more) lip(s);

[0116] 112 (in the side wall) through hole;

[0117] 113 insulated cable;

[0118] 114 socket or plug;

[0119] 115 plug or socket;

[0120] 116 body;

[0121] 117 cover;

[0122] 120 insulating member;

[0123] 121 (in the insulating member) opening.

Claims

1. A ceiling-mounted air conditioning indoor unit (1), the ceiling-mounted air conditioning indoor unit (1) being used for a heat pump including a refrigerant circuit, the indoor unit comprising: A housing (2), the housing (2) including an air inlet (2a) and at least one air outlet (2b); A drain plate (3) is located at the bottom part of the housing (2), and the drain plate (3) has a first edge (3a) and a second edge (3b); A heat exchanger (4), which is part of the refrigerant circuit, is arranged above the drain pan (3) so that water dripping from the heat exchanger (4) accumulates in the drain pan (3); A fan (5), which is housed in the housing (2), draws air in from the air inlet (2a) and passes it through the heat exchanger (4) and discharges it from the at least one air outlet (2b); A flared opening (6), located at the air inlet (2a), is used to guide the intake air to the fan (5); and A refrigerant leak detection sensor (7), wherein the refrigerant leak detection sensor (7) is used to detect refrigerant leaking from the refrigerant circuit, characterized in that, The refrigerant leak detection sensor (7) is located between the outer surface (8) of the second edge (3b) of the drain pan (3) and the inner surface (9) of the flared opening (6), wherein the outer surface (8) of the second edge (3b) of the drain pan (3) and the inner surface (9) of the flared opening (6) face each other. The refrigerant leak detection sensor (7) is a gas sensor (104), which has a housing (105) and a refrigerant receiving area (106) located at the end of the housing (105), the refrigerant receiving area (106) allowing gaseous refrigerant to enter the housing (105). The refrigerant leak detection sensor (7) also includes a sensor housing (102). The outer casing (105) protrudes through the opening (107) of the sensor housing (102) so that the refrigerant receiving area (106) is arranged outside the sensor housing (102). The outer casing (105) protrudes downward from the opening (107).

2. The ceiling-mounted air conditioning indoor unit (1) as described in claim 1, characterized in that, The ceiling-mounted air conditioning indoor unit (1) is provided with a manifold, which connects the refrigerant piping of the heat exchanger (4) to the refrigerant circuit at the first end (4a) of the heat exchanger, wherein the refrigerant leak detection sensor (7) is located near the first end and the manifold.

3. The ceiling-mounted air conditioning indoor unit (1) as described in claim 2, characterized in that, The heat exchanger (4) is circumferentially surrounding the air inlet (2a) and has a second end (4b) opposite to the first end (4a), wherein the first end (4a) and the second end (4b) point to each other, wherein the refrigerant leak detection sensor (7) is arranged near the first end (4a) and the second end (4b) of the heat exchanger (4).

4. The ceiling-mounted air conditioning indoor unit (1) as described in claim 1, characterized in that, The refrigerant receiving area (106) is located below the top of the second edge (3b) of the drain pan (3) and / or below the top of the inner surface (9) of the flared mouth (6).

5. The ceiling-mounted air conditioning indoor unit (1) as described in claim 1, characterized in that, The refrigerant leak detection sensor (7) also includes: A circuit board (103) is surrounded by the sensor housing (102), wherein the gas sensor (104) is mounted on the circuit board (103), and a sensing element is also provided in the housing (105), wherein the sensing element is located inside the sensor housing (102).

6. The ceiling-mounted air conditioning indoor unit (1) as described in claim 5, characterized in that, The sensor housing (102) has a mounting surface (108) mounted on the horn (6), wherein the opening (107) is provided on a first wall (102a) of the sensor housing (102) facing the mounting surface (108), and the outer shell (105) of the gas sensor (104) protrudes toward the mounting surface (108).

7. The ceiling-mounted air conditioning indoor unit (1) as described in claim 6, characterized in that, The sensor housing (102) includes a leg (109) that connects the sensor housing (102) to the mounting surface (108), thereby forming a passage with opposing open ends between the leg (109), the first wall (102a) and the flared mouth (6).

8. The ceiling-mounted air conditioning indoor unit (1) as described in claim 6, characterized in that, A first portion of the first wall (102a) having the opening (107) is arranged further away from the mounting surface (108) than a second portion of the first wall (102a), wherein the first portion of the first wall (102a) and the second portion of the first wall (102a) are connected by an inclined surface.

9. The ceiling-mounted air conditioning indoor unit (1) as described in claim 8, characterized in that, The refrigerant leak detection sensor (7) is positioned along with the inner surface (9) of the first portion facing the horn (6).

10. The ceiling-mounted air conditioning indoor unit (1) as described in any one of claims 5 to 9, characterized in that, A through hole (112) is provided in the second wall (102b) of the outer surface (8) of the second edge (3b) of the sensor housing (102) facing the drain pan (3), and an insulated cable electrically connected to the gas sensor (104) passes through the through hole (112) of the second wall (102b).

11. The ceiling-mounted air conditioning indoor unit (1) as described in any one of claims 1 to 9, characterized in that, The ceiling-mounted air conditioning indoor unit (1) also includes an electrical box (10), wherein the refrigerant leak detection sensor (7) is electrically connected to the components in the electrical box (10) via a sensor cable (11).

12. The ceiling-mounted air conditioning indoor unit (1) as described in claim 11, characterized in that, The housing (2) of the indoor unit (1) has four side walls, the electrical box (10) is located on the outside of one of the four side walls, and the refrigerant leak detection sensor (7) is located on the inside of the side wall where the electrical box (10) is located.

13. The ceiling-mounted air conditioning indoor unit (1) as described in claim 11, characterized in that, The drain pan (3) has an air inlet side surface (3c), and the sensor cable (11) connecting the refrigerant leak detection sensor (7) to the components in the electrical box (10) travels from the refrigerant leak detection sensor (7) to the air inlet side surface (3c) of the drain pan (3), and along the air inlet side surface (3c) of the drain pan (3) to the components in the electrical box (10).

14. The ceiling-mounted air conditioning indoor unit (1) as described in claim 13, characterized in that, A groove (12) is provided on the air inlet side surface (3c) of the drain pan (3) extending from the second edge (3b) of the drain pan (3) to the first edge (3a) of the drain pan (3), and the sensor cable (11) is accommodated in the groove (12).

Images