REFRIGERANT LEAKAGE DETECTION SENSOR FOR A HEAT PUMP AND AIR CONDITIONING APPARATUS INCLUDING SAME

Abstract

A refrigerant leakage detection sensor for a heat pump includes a sensor casing, a circuit board enclosed by the sensor casing, and a gas sensor mounted on the circuit board. The gas sensor has a housing, a refrigerant reception area at an end of the housing allowing gaseous refrigerant to enter the housing, and a sensing element in the housing. The housing protrudes through an opening in the sensor casing so that the refrigerant reception area is arranged outside the sensor casing and the sensing element is positioned inside the sensor casing.

Claims

1. A refrigerant leakage detection sensor for a heat pump, the refrigerant leakage detection sensor comprising: a sensor casing; a circuit board enclosed by the sensor casing; and a gas sensor mounted on the circuit board, the gas sensor having a housing, a refrigerant reception area at an end of the housing allowing gaseous refrigerant to enter the housing, and a sensing element in the housing, the housing protruding through an opening in the sensor casing so that the refrigerant reception area is arranged outside the sensor casing and the sensing element is positioned inside the sensor casing.

2. The refrigerant leakage detection sensor according to claim 1, wherein the sensor casing has a mounting surface usable to mount the sensor casing to a structural element, and the opening is provided in a first wall of the sensor casing, and the housing of the gas sensor protrudes toward the mounting surface.

3. The refrigerant leakage detection sensor according to claim 2, wherein the sensor casing includes legs connecting the sensor casing to the mounting surface such that a passage having opposite open ends is formed below the first wall and between the legs.

4. The refrigerant leakage detection sensor according to claim 2, wherein a lip is provided at a free edge of an outer circumference of the first wall, the lip protruding toward the mounting surface.

5. The refrigerant leakage detection sensor according to claim 2, wherein a first portion of the first wall having the opening is arranged further away from the mounting surface than a second portion of the first wall.

6. The refrigerant leakage detection sensor according to claim 5, wherein the first portion of the first wall and the second portion of the first wall are connected by an inclined surface.

7. The refrigerant leakage detection sensor according to claim 1, wherein a through hole is provided in a second wall of the sensor casing in order to pass an isolated electrical cable to be connected to the circuit board through the second wall in a sealed manner.

8. The refrigerant leakage detection sensor according to claim 7, wherein the through hole in the second wall tapers toward the outside of the sensor casing.

9. The refrigerant leakage detection sensor according to claim 7, wherein a socket or plug is mounted on the circuit board in order to releasably connect a plug or socket at an end of the isolated electrical cable, and the socket or plug on the circuit board is accommodated in the sensor casing on a side of the circuit board facing the first wall.

10. The refrigerant leakage detection sensor according to claim 5, wherein a through hole is provided in a second wall of the sensor casing in order to pass an isolated electrical cable to be connected to the circuit board through the second wall in a sealed manner, and the second wall having the through hole is located closer to the second portion of the first wall than to the first portion of the first wall.

11. The refrigerant leakage detection sensor according to claim 1, wherein the housing of the gas sensor protrudes through the opening the sensor casing in a sealed manner.

12. The refrigerant leakage detection sensor according to claim 1, wherein the sensor casing includes a body and a lid detachably fixed to the body, and mating surfaces of the body and the lid overlap in a direction perpendicular to a fixation direction.

13. The refrigerant leakage detection sensor according to claim 1, wherein circuit board is arranged in the sensor casing further away from the first wall than from a third wall, preferably opposite to the first wall.

14. The refrigerant leakage detection sensor according to claim 1, wherein the sensor casing is at least partly thermally insulated by an insulation member.

15. Air conditioner apparatus including the refrigerant leakage detection sensor according to claim 1.

16. The refrigerant leakage detection sensor according claim 2, wherein the housing of the gas sensor protrudes through the opening in the sensor casing in a sealed manner.

17. The refrigerant leakage detection sensor according to claim 2, wherein the sensor casing includes a body and a lid detachably fixed to the body, and mating surfaces of the body and the lid overlap in a direction perpendicular to a fixation direction.

18. The refrigerant leakage detection sensor according to claim 2, wherein the circuit board is arranged in the sensor casing further away from the first wall than from a third wall opposite to the first wall.

19. The refrigerant leakage detection sensor according to claim 2, wherein the sensor casing is at least partly thermally insulated by an insulation member.

20. Air conditioner apparatus including the refrigerant leakage detection sensor according to claim 2.

Description

BRIEF DESCRIPTION OF DRAWINGS

[0032] A more complete appreciation of the present disclosure and many of the attendant advantages thereof will be readily obtained as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying drawings.

[0033] FIG. 1 is a schematic illustration showing a conventional refrigerant detection unit of an air-conditioning apparatus;

[0034] FIG. 2 is a schematic three-dimensional illustration of a refrigerant leakage detection sensor according to an aspect of the present invention;

[0035] FIG. 3 is a schematic sectional view of the refrigerant leakage detection sensor shown in FIG. 2;

[0036] FIG. 4 is a schematic three-dimensional illustration of the sectional view shown in FIG. 3;

[0037] FIG. 5 is a schematic sectional view of an isolated electric cable of a refrigerant leakage detection sensor according to an aspect of the present invention; and

[0038] FIG. 6 is a schematic three-dimensional illustration of a refrigerant leakage detection sensor according to another aspect of the present invention.

DESCRIPTION OF EMBODIMENTS

[0039] Several embodiments of the present disclosure will now be explained with reference to the drawings. It will be apparent to those skilled in the field of air-conditioning apparatus from this disclosure that the following description of the embodiments is provided for illustration only and not for the purpose of limiting the disclosure as defined by the appended claims.

[0040] FIG. 1 is a schematic illustration showing a conventional refrigerant detection unit 99 of an air-conditioning apparatus. As illustrated in FIG. 1, the refrigerant detection unit 99 includes a sensor 200, a mount plate, and a sensor cover 230. The mount plate is arranged on the back surface side of the sensor 200. The sensor cover 230 covers the sensor 200 from the front surface side and surrounds the sensor 200 together with the mount plate. The sensor 200 includes a sensor device and a board 210, the board 210 is configured to accommodate the sensor device therein. As also shown in FIG. 1, the sensor cover 230 includes a roof portion 231, a side surface portion 232 and a bottom surface portion. The side surface portion 232 includes a front surface portion 232a, a right side surface portion and a left side surface portion. Moreover, a plurality of opening ports 234a, 234c configured to introduce air to the inside of the sensor cover 230 therethrough are formed in the front, side and bottom surface portion so as to ensure detectability for a leaking refrigerant.

[0041] FIG. 2 is a schematic three-dimensional illustration of a refrigerant leakage detection sensor 1 according to an aspect of the present invention. As FIG. 2 shows, the refrigerant leakage detection sensor 1 includes a sensor casing 2, a circuit board 3 (shown in FIG. 3) and a gas sensor 4. The gas sensor 4 has a housing 5, which can be seen in more detail in FIG. 3, and a refrigerant reception area 6, which is located at the end of the housing 5, e.g. on the top of the housing. The refrigerant reception area 6 is configured to allow gaseous refrigerant to enter the housing 5. In this way, it is possible that gaseous refrigerant enters the housing 5 and thereby reaches a sensing element (not shown) which is located inside the housing 5.

[0042] As can also be taken from FIG. 2, the gas sensor 4, in particular the housing 5 is protruding through an opening 7 arranged in the sensor casing 2 in such a manner that the refrigerant reception area is arranged outside the sensor casing 2. On the other hand, the sensing element (not shown), which is located inside the housing 5, is positioned inside the sensor casing 2.

[0043] Moreover, in order to better show the location of the gas sensor 4 within the sensor casing 2, the refrigerant leakage detection sensor 1 is shown in FIG. 2 upside down. Meaning, a mounting surface 8 that is used for mounting the sensor casing 2 to an external structural element, is shown on top of the sensor casing 2. However, generally, the mounting surface 8 is positioned below the sensor casing. In other words, in an usual mounting situation of the refrigerant leakage detection sensor 1, the sensor is rotated by 180 degrees, as shown in FIG. 3.

[0044] FIG. 3 is a schematic sectional view of the refrigerant leakage detection sensor 1 shown in FIG. 2. By providing a sectional view of the sensor 1, it becomes possible to see the arrangement of the gas sensor 4 and related elements within the sensor casing 2. As shown in FIG. 3, the sensor casing 2 comprises a body 16, which is in the standard mounting position of the sensor the lower part of the sensor casing 2, and a lid 17. The lid 17 is detachably fixed to the body 16, wherein mating surfaces of the body 16 and the lid 17 overlap in a direction perpendicular to a fixation direction. In FIG. 3, the fixation direction is vertical, hence, the mating surfaces of the body 16 and the lid 17 overlap in the horizontal plane.

[0045] In the refrigerant detection sensor 1 shown in FIG. 3, the mating surface of the lid 17 is arranged outside of the mating surface of the body 16, meaning the mating surface of the lid 17 surrounds the mating surface of the body 16, in particular over the entire outer circumference.

[0046] The circuit board 3 of the gas sensor 4 is arranged inside the sensor casing 2 and parallel to a first wall 2a of the sensor casing 2. In the standard mounting position of the sensor 1 shown in FIG. 3, the first wall 2a is a bottom wall of the sensor casing 2 and is located on the side of the mounting surface 8. The first wall 2a is provided with an opening 7, through which the housing 5 of the gas sensor 2 protrudes toward the mounting surface 8.

[0047] Moreover, as shown in FIGS. 2 and 4, the sensor casing 2 is provided with two legs 9 connecting the sensor casing 2 with the mounting surface 8. In other words, the mounting surface(s) 8 is/are provided at the end surface of the legs 9. The legs 9 are arranged in such a manner that between the two legs 9 and the first wall 2a a passage having opposite open ends is formed.

[0048] As can also be taken from FIGS. 3 and 4, the sensor casing 2, in particular the body 16, is provided at a free edge of the outer circumference of the first wall 2a, which is part of the body 16, a lip 10. The lip 10 is formed in such a way that it protrudes toward the mounting surface 8.

[0049] FIG. 3 also shows that the circuit board 3 is arranged in the sensor casing 2 parallel to the first wall 2a and further away from the first wall 2a than from a third wall 2c, which is in standard mounting position of the sensor 1 shown in FIG. 3 a top wall, opposite to the first wall 2a.

[0050] FIG. 4 is a schematic three-dimensional illustration of the sectional view shown in FIG. 3. As can be taken from FIG. 4 (and also FIG. 3), a first portion of the first wall 2a, in FIG. 4 the left portion of the first wall 2a, is arranged further away from the mounting surface than a second portion of the first wall 2a, in FIG. 4 the right portion of the first wall 2a. Accordingly, the overall height of the sensor casing 2 is reduced on the side of the sensor casing 2, where the gas sensor 3 is located. As also shown in FIG. 4, the first portion of the first wall 2a and the second portion of the first wall 2a are connected by an inclined surface, which is accordingly arranged in the middle of the first wall 2a.

[0051] The sensor casing 2 of the refrigerant detection sensor 1 shown in FIGS. 2 to 4 is also provided with a through hole 12, which is located in a second wall 2b of the sensor casing 2, which is a side wall of the sensor casing 2. The through hole 12 is needed for passing an isolated electrical cable 13 into the sensor casing 2. In the embodiment shown in FIGS. 2 to 5, the isolated electrical cable 13 is provided at the one end, which is located inside the sensor casing 2, with a plug 15 that is insertable into a socket 14, which is mounted on the circuit board 3, so that the isolated electrical cable 13 can be connected to the circuit board 3.

[0052] FIG. 5 is a schematic sectional view showing the isolated electric cable 13 of the refrigerant leakage detection sensor 1 enlarged. As can be seen in FIG. 5, the through hole 12 in the second wall 2b of the sensor casing 2 is formed in such a way that it tapers toward the outside of the sensor casing 2. Moreover, it is advantageous if the isolated electrical cable 13 is passed through the through hole 12 in a sealed manner. FIG. 5 also shows that the socket 14 is accommodated on the circuit board 3 on a side of the circuit board 3 facing the first wall/bottom wall 2a. Yet, as particularly shown in FIG. 4, the second wall 2b having the through hole 12 is located closer to the second portion of the first wall (2a) than to the first portion of the first wall (2a).

[0053] FIG. 6 is a schematic three-dimensional illustration of a refrigerant leakage detection sensor 1 according to another aspect of the present invention. The shown refrigerant leakage detection sensor 1 basically corresponds to the refrigerant leakage detection sensor 1 described with regard to FIGS. 2 to 5, except that the in FIG. 6 shown sensor 1 additionally is provided with an insulation member 20, which partially thermally insulates the sensor casing 2.

[0054] The insulation member 20 is provided with an opening 21, through which the housing 5 of the gas sensor 4 partially protrudes. In the shown embodiment it is preferred that the housing 5 protrudes through the opening 21 in a sealed manner, making it possible that the housing 5 can protrude through the opening 7 of the sensor casing 2 with clearance, in particular in a not sealed manner. The sealing between the insulation member 20 and the housing 5 of the gas sensor 4 can be achieved by a press-fitting, which is particularly advantageous or easy to realize in case the insulation member 20 is made of an elastic material like polyethylene foam.

REFERENCE SIGNS LIST

[0055] 1 Refrigerant leakage detection sensor

[0056] 2 Sensor casing

[0057] 2a fist wall (bottom wall)

[0058] 2b Second wall (side wall)

[0059] 2c Third wall (top wall)

[0060] 3 Circuit board (PCB)

[0061] 4 Gas sensor

[0062] 5 Housing (of gas sensor)

[0063] 6 Refrigerant reception area

[0064] 7 Opening (in the sensor casing)

[0065] 8 Mounting surface(s)

[0066] 9 Legs

[0067] 10 Lip(s)

[0068] 12 Through hole (in side wall)

[0069] 13 Isolated electric cable

[0070] 14 Socket or plug

[0071] 15 Plug or Socket

[0072] 16 Body

[0073] 17 Lid

[0074] 20 Insulating member

[0075] 21 Opening (in insulating member)