Freezing air conditioner

Abstract

To provide a freezing air conditioner capable of accurately detecting a refrigerant leaked from an outdoor unit according to an installation location of the outdoor unit.SOLUTION: An air conditioner (100) of the present invention comprises an indoor unit (102) that exchanges heat between indoor air and a refrigerant, and an outdoor unit (101) that exchanges heat between outdoor air and the refrigerant. The refrigerant is flammable. The outdoor unit (101) has a refrigerant detection sensor (S) located below a bottom base (bottom plate (1d)) constituting a housing (1) of the outdoor unit (101).SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a refrigeration and air conditioning apparatus. [Background technology]

[0002] In recent air conditioners, which require refrigerants with both low GWP (Global Warming Potential) and low ODP (Ozone Depletion Potential), air conditioners using a highly flammable refrigerant (R290: propane) have been put to practical use. BACKGROUND ART Conventionally, air conditioners have been known in which a refrigerant detection sensor is provided inside the housing of the indoor unit or in a predetermined opening formed in the housing (see, for example, Patent Document 1). According to such an air conditioner, a safety measure can be taken by detecting refrigerant leakage in the indoor unit with the refrigerant detection sensor. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2017-83083 Summary of the Invention [Problem to be solved by the invention]

[0004] However, refrigerant leakage in air conditioners can occur not only in the indoor unit but also in the outdoor unit, so safety measures must be taken to prevent refrigerant leakage from the outdoor unit as well. However, unlike indoor units installed indoors, outdoor units may be exposed to various installation environments. For example, if an outdoor unit is installed in a narrow space, leaking refrigerant is likely to remain in the space, increasing its concentration and making it more susceptible to ignition. Furthermore, considering the mobility characteristics of flammable refrigerants, which are heavier than air, safety measures for air conditioners must be taken depending on the installation location of the outdoor unit, such as when the outdoor unit is installed on a narrow balcony, when luggage is placed near the outdoor unit, or when the outdoor unit is installed at a high altitude. In other words, an air conditioner that can accurately detect refrigerant leaks in the outdoor unit depending on the installation location of the outdoor unit is desired.

[0005] An object of the present invention is to provide a refrigeration and air conditioning apparatus that can accurately detect refrigerant leakage from an outdoor unit depending on the installation location of the outdoor unit. [Means for solving the problem]

[0006] The refrigeration and air conditioning equipment of the present invention comprises an outdoor unit that uses a refrigerant to exchange heat with outdoor air, water, brine or a secondary refrigerant, the refrigerant being flammable, and the outdoor unit is configured so that a refrigerant detection sensor can be positioned below a bottom base that forms the bottom surface of the outdoor unit's housing. [Effects of the Invention]

[0007] According to the refrigeration and air conditioning apparatus of the present invention, refrigerant leakage from the outdoor unit can be accurately detected depending on the installation location of the outdoor unit. [Brief explanation of the drawings]

[0008] [Figure 1] 1 is a configuration explanatory diagram of an air conditioner (refrigeration air conditioning equipment) according to an embodiment of the present invention. [Figure 2] FIG. 2 is a perspective view showing the outdoor unit with the front panel, top panel, and cover members on the side surfaces of the housing removed. [Figure 3] 5 is a flowchart showing a procedure executed by a control unit of the outdoor unit. [Figure 4] FIG. 4 is a diagram illustrating the configuration of a first modified example of the outdoor unit. [Figure 5] FIG. 10 is a diagram illustrating the configuration of a second modified example of the outdoor unit. [Figure 6] FIG. 10 is a diagram illustrating the configuration of a third modified example of the outdoor unit. DETAILED DESCRIPTION OF THE INVENTION

[0009] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a detailed description will be given of a mode (embodiment) for carrying out a refrigeration and air conditioning apparatus of the present invention, with reference to the drawings as appropriate. The air conditioner of this embodiment, which functions as a refrigeration and air conditioning appliance, has a refrigerant detection sensor located below the bottom base of the outdoor unit. That is, the air conditioner of this embodiment is configured so that the location of the refrigerant detection sensor, which is set below the bottom base of the outdoor unit, can be adjusted depending on the installation location of the outdoor unit. Below, the overall configuration of the air conditioner will be described, and then the refrigerant detection sensor will be described in more detail.

[0010] FIG. 1 is a diagram illustrating the configuration of an air conditioner 100 according to this embodiment. As shown in FIG. 1, the air conditioner 100 includes an outdoor unit 101 installed outdoors and an indoor unit 102 installed indoors. The air conditioner 100 of this embodiment is configured with a compression-type refrigeration cycle using R290 (propane) as an example of a flammable refrigerant. Compression-type refrigeration cycles using R290 in the outdoor unit include chillers that exchange heat with hot or cold water, water heaters, and refrigerators with secondary circuits, and are not limited to the configuration shown in FIG. 1. However, the refrigerant in the air conditioner of the present invention is not limited to R290. Examples include single hydrocarbon (HC) refrigerants such as R170 (ethane), R1270 (propylene), and R600a (isobutane), as well as mixed HC refrigerants of these. The refrigerant may also be a fluorine-based refrigerant such as HFO-1234yf or R-32. Alternatively, a mixed refrigerant of these refrigerants may be used. Flammable refrigerants include mildly flammable and highly flammable refrigerants. Furthermore, in this embodiment, a refrigerant having a specific gravity greater than that of air is preferably used as the refrigerant.

[0011] During cooling operation, the air conditioner 100 takes in liquid refrigerant (including gas-liquid two-phase refrigerant) from the outdoor unit 101 via the liquid piping 20 to flow through the heat transfer tubes of the indoor heat exchanger (not shown) in the indoor unit 102. At this time, the indoor heat exchanger (not shown) functions as an evaporator to cool the surrounding air (room air). The gas refrigerant vaporized in the indoor heat exchanger is then sent to the outdoor unit 101 via the gas piping 30.

[0012] Furthermore, during heating operation, the air conditioner 100 sends high-temperature, high-pressure gas refrigerant from a compressor 7 (see FIG. 2), which will be described later, to the indoor unit 102 via gas piping 30 by switching the refrigerant flow path using a four-way valve (not shown) in the outdoor unit 101. At this time, the indoor heat exchanger (not shown) functions as a condenser to heat the surrounding air (indoor air). Then, the liquid refrigerant (including two-phase gas-liquid refrigerant) condensed in the heat transfer tube (not shown) of this indoor heat exchanger is sent to the outdoor unit 101 via liquid piping 20. 1, reference numeral 102a denotes an alarm display unit (described later) provided in the indoor unit 102. Reference numeral L2 denotes a signal line that electrically connects an alarm transmission circuit (not shown) (described later) and a control board (not shown) of the outdoor unit 101.

[0013] Next, the outdoor unit 101 will be described in more detail. As shown in FIG. 1, the housing 1 of the outdoor unit 101 is configured to include a bottom plate 1d (bottom base), and on this bottom plate 1d, a front plate 1a, a side plate 1b, and a top plate 1c. A cover member 6 is detachably attached to the right side plate 1b. Specifically, the cover member 6 has a claw (not shown) that engages with an engaging portion (not shown) consisting of a vertical slit provided on the side plate 1b. The cover member 6 can be engaged and disengaged by moving up and down relative to the side plate 1b.

[0014] The cover member 6 covers, at its upper part, a relay terminal portion 13 (see FIG. 2) to which a signal cable 11 of a refrigerant detection sensor S, which will be described in detail later, is connected. The cover member 6 also covers, at its lower part, a connection portion 20a (see FIG. 2) of a liquid pipe 20 and a connection portion 30a (see FIG. 2) of a gas pipe 30. In FIG. 1, reference numeral 1a2 denotes a fan grill attached to the opening 1a1 of the front panel 1a.

[0015] FIG. 2 is a perspective view showing the outdoor unit 101 with the front panel 1a (see FIG. 1), top panel 1c (see FIG. 1), and cover member 6 (see FIG. 1) that constitute the housing 1 removed. As shown in FIG. 2, an outdoor fan 9, a compressor 7, an accumulator 4, and an outdoor heat exchanger 3 are arranged inside the outdoor unit 101. Specifically, the interior of the outdoor unit 101 is divided into a blower chamber 5b and a machine chamber 5a by a partition plate 2. The outdoor fan 9 is disposed in the blower chamber 5b, and the compressor 7 and accumulator 4 are disposed in the machine chamber 5a. The outdoor heat exchanger 3 is provided from the fan chamber 5b to the machine chamber 5a along the side panel 1b and back surface (rear surface) of the outdoor unit 101. The side panel 1b and back surface (rear surface) of the outdoor unit 101 form an intake section (not shown) for outdoor air to enter the inside of the outdoor unit 101.

[0016] During cooling operation, the outdoor heat exchanger 3 functions as a condenser, and sends liquid refrigerant (including gas-liquid two-phase refrigerant) back to the indoor unit 102 (see FIG. 1) via the liquid piping 20 (see FIG. 1). During heating operation, the outdoor heat exchanger 3 functions as an evaporator, and sends gas refrigerant from the compressor 7 back to the indoor unit 102 via the gas piping 30 (see FIG. 1). The accumulator 4 separates the gas refrigerant from the liquid refrigerant of the gas-liquid two-phase refrigerant sent via the liquid piping 20 (see FIG. 1), and sends it to the compressor 7.

[0017] The outdoor fan 9 rotates to blow air so that the outdoor heat exchanger 3 is on the upstream side and the fan grill 1a2 (see FIG. 1) is on the downstream side. In this way, the outdoor fan 9 circulates the outdoor air that has been drawn into the outdoor unit 101 from the suction section (not shown) through the outdoor heat exchanger 3, promoting heat exchange between the refrigerant flowing through the outdoor heat exchanger 3 and the outdoor air.

[0018] As shown in FIG. 2, an electric component box 8 having a control board 8a is disposed inside the upper part of the housing 1. A terminal unit 12 for powering the outdoor unit 101 is provided on the upper right side surface of the housing 1. In addition, a relay terminal unit 13 is provided adjacent to the terminal unit 12 on the upper right side surface of the housing 1. The relay terminal unit 13 is electrically connected to the control board 8a. As described above, the signal cable 11 (see FIG. 1) is connected to the relay terminal unit 13. That is, the refrigerant detection sensor S (see FIG. 1) is electrically connected to the control board 8a via the signal cable 11 (see FIG. 1).

[0019] The control board 8a is equipped with electronic components (not shown) that constitute a control unit (not shown) that performs overall control of the air conditioner 100 (see FIG. 1). Furthermore, the control board 8a in this embodiment is equipped with electronic components that perform on / off control of the drive mechanism (not shown) of the outdoor fan 9, on / off control of the drive mechanism (not shown) of the compressor 7, and on / off control of the alarm transmission circuit (not shown), based on a refrigerant detection signal output by the refrigerant detection sensor S (see FIG. 1).

[0020] Such a control unit can be configured to include a ROM (Read Only Memory) that stores control programs for the drive mechanism (not shown) and the alarm transmission circuit (not shown), a RAM (Random Access Memory) that reads out and deploys the control program stored in the ROM, and a CPU (Central Processing Unit) that executes the procedures specified in the deployed control program and outputs commands to the drive mechanism (not shown) and the alarm transmission circuit (not shown). The procedure of the control program executed by this control unit will be explained together with the operation of the air conditioner 100 (see FIG. 1) described below.

[0021] Returning to Figure 1, a refrigerant detection sensor S is detachably attached to one end of signal cable 11. The other end of signal cable 11 is detachably attached to a connector that constitutes relay terminal unit 13 (see Figure 2). Modular plugs (not shown) that connect to refrigerant detection sensor S and relay terminal unit 13 are attached to both ends of signal cable 11.

[0022] The refrigerant detection sensor S in this embodiment is not particularly limited as long as it can detect the concentration of R290, and for example, a semiconductor gas sensor, an infrared gas sensor, a thermal conduction gas sensor, or other sensors can be used. In this embodiment, the refrigerant detection sensor S is attached to the underside of the bottom plate 1d (bottom base) that constitutes the housing 1. Specifically, it is located on the front lower side of the bottom plate 1d (bottom base), approximately in the center in the left-right direction of the opening 1a1 of the front plate 1a.

[0023] The refrigerant detection sensor S has a permanent magnet and is fixed to the bottom plate 1d (bottom base). However, the method of attaching the refrigerant detection sensor S to the bottom plate 1d (bottom base) is not limited to this, and the sensor can also be detachably attached using a predetermined metal fitting or the like.

[0024] Power is supplied to the refrigerant detection sensor S via signal cable 11. However, the power supply to the refrigerant detection sensor S is not limited to this, and it can also be supplied by a battery built into the refrigerant detection sensor S. The refrigerant detection sensor S can also be equipped with a solar battery or a vibration power generation element. Incidentally, the vibration power generation element has a piezoelectric element that receives vibrations generated by the outdoor fan 9 and compressor 7 via the housing 1.

[0025] The length of the signal cable 11 shown in Figure 1 can be adjusted depending on the position of the refrigerant detection sensor S and the installation location of the outdoor unit 101, as with the signal cable 11 in variant 1 (see Figure 4) and variant 2 (see Figure 5) of the outdoor unit 101 described below. Therefore, in the outdoor unit 101 shown in Figure 1, the length of the signal cable 11 can be determined, for example, by calculating at least the length from the relay terminal part 13 provided on the upper right side surface of the housing 1 to the lower end of the right side panel 1b, and the length from the lower end of the right side panel 1b to the position where the refrigerant detection sensor S is located. Furthermore, if the refrigerant detection sensor S is positioned further downward than the position of the refrigerant detection sensor S shown in Fig. 1 (see Figs. 4 and 5), the length of the signal cable 11 will be longer than the length of the signal cable 11 shown in Fig. 1. However, if the distance between the outdoor unit and the refrigerant detection sensor S increases, the refrigerant will diffuse, delaying the detection of an early stage leak. To speed up detection, it is desirable that the length of the signal cable 11 be 2 m or less.

[0026] Incidentally, when the air conditioner 100 of this embodiment is put on the market, for example, the outdoor unit 101, indoor unit 102, liquid piping 20, gas piping 30, etc. will be packaged with multiple signal cables 11 with modular plugs of different lengths according to the expected placement position of the refrigerant detection sensor S.

[0027] In this air conditioner 100, the outdoor unit 101 and the indoor unit 102 are installed in a predetermined location, and after the outdoor unit 101 and the indoor unit 102 are connected by the liquid piping 20 and the gas piping 30, the refrigerant detection sensor S is placed in a predetermined position by the installer. The refrigerant detection sensor S can be attached to a predetermined position in accordance with the installation conditions indicated on the display unit 14 shown in FIG.

[0028] As shown in FIG. 2, the display unit 14 is provided on the outside of the housing 1 (side panel 1b) at a position covered by the cover member 6 (see FIG. 1). The display unit 14 displays precautions such as attaching a modular plug of the signal cable 11 to the relay terminal unit 13 when the outdoor unit 101 is installed in a small, poorly ventilated area. The display unit 14 can also display a notice instructing the user to refer to the instruction manual for the outdoor unit 101.

[0029] Furthermore, the display unit 14 can also display the inequality shown in the following formula (1) as a guide for the space in which the outdoor unit 101 is installed. m max ≧0.5×LFL×A×h (1) (In formula (1), m max is the allowable refrigerant amount [kg], LFL is the lower flammability limit of the refrigerant [kg / m 3 ], A is the area [m 2 ], h is the expected refrigerant accumulation height or the height of the outdoor unit [m])

[0030] Next, the operation of the air conditioner 100 will be explained while explaining the procedures executed by the control unit (hereinafter simply referred to as the "control unit") displayed as the control board 8a (see Figure 2) of this air conditioner 100 (see Figure 1) based on a control program.

[0031] FIG. 3 is a flowchart showing the procedure executed by the control unit. When power is supplied to the air conditioner 100 (see FIG. 1), the control unit detects the refrigerant gas concentration in the outdoor air based on the refrigerant detection signal output by the refrigerant detection sensor S (see FIG. 1) (step S101). Next, the control unit determines whether the detected refrigerant gas concentration exceeds a preset threshold (step S102). The threshold is set according to the flammability of the refrigerant, taking into account a safety factor. For example, the threshold may be set to detect a concentration of 25% or less of the lower flammable limit (LFL) of the refrigerant. If the detected refrigerant gas concentration does not exceed the threshold (No in step S102), the determination in step S102 is repeated.

[0032] Furthermore, if the detected refrigerant gas concentration exceeds the threshold value (Yes in step S102), the control unit outputs an alarm command to an alarm transmission circuit (not shown) of the indoor unit 102 (see FIG. 1) via signal line L2 (see FIG. 1) (step S103). The alarm transmission circuit (not shown) causes an alarm display unit 102a (see FIG. 1) of the indoor unit 102 (see FIG. 1) to display that there is a refrigerant leak in the outdoor unit 101 (see FIG. 1). In this embodiment, the alarm display unit 102a is configured as an alarm lamp, but it can also be configured as a text display or an audio display such as a beep or a voice sound.

[0033] On the other hand, the outdoor fan 9 may stop rotating, for example, when the air conditioner is stopped or the indoor temperature is maintained at a target temperature. In response to this, the control unit determines whether the outdoor fan 9 (see FIG. 2) is stopped (step S104). If the outdoor fan 9 is stopped (Yes in step S104), the control unit outputs a command to start rotation of the outdoor fan 9 to a drive mechanism (not shown) of the outdoor fan 9 (step S105). As the outdoor fan 9 rotates, it exhausts air from the blower chamber 5b (see FIG. 2) through the opening 1a1 (see FIG. 1) in the front panel 1a (see FIG. 1).

[0034] Following step S105, the control unit determines whether the detected refrigerant gas concentration is below a preset threshold based on the refrigerant detection signal output by the refrigerant detection sensor S (see FIG. 1) (step S106). If the detected refrigerant gas concentration is below the threshold (Yes in step S106), the control unit outputs a drive stop command to a drive mechanism (not shown) of the outdoor fan 9 (see FIG. 2) so that the outdoor fan 9 stops after a predetermined time has elapsed (step S107). The control unit ends the control process of this subroutine.

[0035] Furthermore, if the control unit determines in step S104 that the outdoor fan 9 (see FIG. 2) has not stopped (No in step S104), or if the detected refrigerant gas concentration is not less than the threshold value in step S106 (No in step S106), it executes step S108 and then goes through step S107 to end the control process of this subroutine. That is, in step S108, the control unit outputs a command to at least the drive mechanism (not shown) of the compressor 7 to stop the operation of the compressor 7, while maintaining the rotational drive of the outdoor fan 9 (see FIG. 2). By stopping the drive of at least the compressor 7, the amount of refrigerant leakage can be reduced.

[0036] <Action and effect> Next, the effects and advantages achieved by the air conditioner 100 of this embodiment will be described. The air conditioner 100 of this embodiment comprises an indoor unit 102 that exchanges heat between indoor air and a refrigerant, and an outdoor unit 101 that exchanges heat between outdoor air and a refrigerant, the refrigerant being flammable, and the outdoor unit 101 having a refrigerant detection sensor S below a bottom plate 1d (bottom base) that constitutes the housing 1 of the outdoor unit 101. In other words, the refrigerant detection sensor S is disposed between the bottom plate 1d (bottom base) of the outdoor unit 101 and the floor surface located below the outdoor unit 101.

[0037] In general, refrigerant (R290: propane) is heavier than air, so that refrigerant leaking from the outdoor unit 101 moves downward from the outdoor unit 101. If the outdoor unit 101 is installed in, for example, a small space, the refrigerant will accumulate on the floor below the outdoor unit 101. That is, even if the amount of refrigerant leaking from the outdoor unit 101 is small, the accumulated refrigerant may exceed the flammable limit concentration. Therefore, in an air conditioner 100 having a refrigerant detection sensor S inside the housing 1 of the outdoor unit 101, the accumulated refrigerant may ignite and burn even if the refrigerant detection sensor S does not detect the refrigerant.

[0038] In contrast, according to the air conditioner 100 of this embodiment, the refrigerant detection sensor S is located below the bottom plate 1d (bottom base) of the outdoor unit 101, so that refrigerant leaking from the outdoor unit 101 can be detected accurately.

[0039] Furthermore, in this air conditioner 100, the refrigerant detection sensor S is connected to the control board 8a of the outdoor unit 101 by a signal cable 11 (wired) so that the position of the refrigerant detection sensor S can be adjusted between the bottom plate 1d (bottom base) of the outdoor unit 101 and the floor surface located below the outdoor unit 101. Furthermore, the refrigerant detection sensor S can also be connected wirelessly, as will be described later (see FIG. 6). According to such an air conditioner 100, refrigerant leakage in the outdoor unit 101 can be accurately detected depending on the installation location of the outdoor unit 101.

[0040] Furthermore, in this air conditioner 100, the refrigerant detection sensor S can be configured to be attached to the underside of the bottom plate 1d (bottom base). Incidentally, the sensor installation work for the refrigerant detection sensor S is carried out at least after installing the outdoor unit 101. At this time, the installer checks the installation site of the outdoor unit 101 and determines the location of the refrigerant detection sensor S. If the refrigerant detection sensor S is placed on the floor, it is conceivable that the refrigerant detection sensor S will be exposed to rainwater or drain water that soaks into the floor. In contrast, the air conditioner 100 is detachably attached to the underside of the bottom plate 1d (bottom base), and is therefore not exposed to rainwater or drainage water that soaks into the floor surface.

[0041] Furthermore, in this air conditioner 100, the refrigerant detection sensor S is detachably supported at its installation position. According to this air conditioner 100, the refrigerant detection sensor S can be easily attached and detached at its arrangement position.

[0042] In addition, in this air conditioner 100, the refrigerant detection sensor S and the control board 8a are connected by a signal cable 11. According to this air conditioner 100, by adjusting the length of the signal cable 11, the position of the refrigerant detection sensor S below the outdoor unit 101 can be easily adjusted. Furthermore, with this air conditioner 100, the influence of noise is reduced compared to when the refrigerant detection sensor S and the control board 8a are connected wirelessly. Furthermore, according to this air conditioner 100, the refrigerant detection sensor S is connected to the outdoor unit 101 via the signal cable 11, reducing the risk of the refrigerant detection sensor S becoming detached from the outdoor unit 101 and being lost.

[0043] In addition, in this air conditioner 100, the outdoor unit 101 has a relay terminal section 13 electrically connected to the control board 8a on the outside of the housing 1, and one end of a signal cable 11 is connected to the refrigerant detection sensor S, and the other end is electrically and detachably connected to the relay terminal section 13. According to this air conditioner 100, the signal cable 11 can be electrically connected to the control board 8a more easily than in an air conditioner in which the signal cable 11 is directly connected to the control board 8a inside the housing 1. Furthermore, routing of the signal cable 11 to the outdoor unit 101 is also simplified.

[0044] Furthermore, in this air conditioner 100, a display unit 14 for displaying the installation conditions of the refrigerant detection sensor S is provided on the outside of the housing 1 of the outdoor unit 101. With this type of air conditioner 100, when the contractor decides where to place the refrigerant detection sensor S, they can define and indicate small spaces where sensor installation is recommended, thereby eliminating worker errors and ensuring safety.

[0045] Furthermore, in this air conditioner 100, a control unit that performs overall control of the air conditioner 100 is defined on the control board 8a, and the control unit executes a procedure for outputting refrigerant detection information to the alarm display unit 102a of the indoor unit 102 based on the refrigerant detection signal output from the refrigerant detection sensor S. According to this air conditioner 100, if a refrigerant leaks in the outdoor unit 101, it is possible to notify a user who is indoors of the refrigerant leak.

[0046] Furthermore, in this air conditioner 100, a control unit that performs overall control of the air conditioner 100 is defined on the control board 8a, and the control unit executes a procedure to rotate the outdoor fan 9 for a predetermined time and then stop the outdoor fan 9 based on the refrigerant detection signal output from the refrigerant detection sensor S. With this air conditioner 100, it is possible to forcibly discharge the refrigerant remaining in the blower chamber 5b. Furthermore, with this air conditioner 100, by rotating the outdoor fan 9 for a predetermined time and then stopping the outdoor fan 9, it is possible to prevent the refrigerant from accumulating where the outdoor unit 101 is installed if refrigerant leakage from the outdoor unit 101 continues.

[0047] Although the embodiments of the present invention have been described above, the present invention is not limited to the above embodiments and can be embodied in various forms. Below, first, second, and third modified examples of the outdoor unit 101 according to other embodiments will be described with reference to Figures 4 to 6. In these modified examples, the same components as those in the outdoor unit 101 according to the above embodiment will be assigned the same reference numerals, and detailed description thereof will be omitted. In Figures 4 to 6, reference numeral 1 denotes a housing, reference numeral 1d denotes a bottom plate (bottom base), reference numeral 8a denotes a control board (control unit), reference numeral 9 denotes an outdoor fan, and reference numeral 11 denotes a signal cable.

[0048] (First Modification) FIG. 4 is a structural explanatory diagram that schematically illustrates a first modified example of the outdoor unit 101 (see FIG. 1). As shown in FIG. 4, in the first modified example of the outdoor unit 101, the refrigerant detection sensor S is disposed on the floor surface F. Specifically, the outdoor unit 101 is placed in a small space 15 . According to the first modified example, refrigerant leakage can be detected quickly and accurately. This first modified example is a suitable configuration when the outdoor unit 101 is installed on a concrete block, a plastic block, or a high stand, and the floor surface F and the outdoor unit 101 are spaced apart.

[0049] (Second Modification) FIG. 5 is a structural explanatory diagram that schematically illustrates a second modified example of the outdoor unit 101 (see FIG. 1). 5, in the second modified example of the outdoor unit 101, the outdoor unit 101 is installed at a high position. In this second modified example, the distance from the floor surface F is even greater than that of the outdoor unit 101 installed on the floor surface F. According to the second modified example, the refrigerant remaining on the floor surface F can be detected accurately. In addition, it is desirable that the length of the signal cable 11 in the second modified example be 2 m or less. According to the second modified example, the length of the signal cable 11 is set to 2 m or less, which satisfies the installation conditions of the outdoor unit 101 that are usually considered, and also makes it possible to reduce installation costs.

[0050] (Third Modification) FIG. 6 is a structural explanatory diagram that schematically shows a third modified example of the outdoor unit 101 (see FIG. 1). As shown in FIG. 6, in the third modified example of the outdoor unit 101, the refrigerant detection sensor S includes a transmitter 22a that wirelessly transmits a refrigerant detection signal, and the control board 8a is configured to acquire the refrigerant detection signal wirelessly transmitted from the refrigerant detection sensor S via a receiver 22b via wireless communication. Although the receiver 22b shown in FIG. 6 is provided on the control board 8a, it may also be provided at an appropriate location inside or outside the electrical equipment box 8 (see FIG. 2). According to this second modified example, unlike the outdoor unit 101 (see Figure 1) in the above embodiment, the signal cable 11 (see Figure 1) is not connected to the refrigerant detection sensor S, so the installation position of the refrigerant detection sensor S can be freely adjusted. As described above, power is supplied to the refrigerant detection sensor S by a built-in battery, a solar battery, a vibration power generating element, etc. Furthermore, although it is assumed that the synchronization of the transmitter 22a and the receiver 22b will be performed by an installer, synchronization can also be performed at a predetermined frequency. [Explanation of symbols]

[0051] 1 chassis 1d Bottom plate (bottom base) 8a Control board (control unit) 9 Outdoor fan 11 Signal cable 13 Relay terminal 14 Display section 22a transmitter 22b receiver 100 Air conditioners (refrigeration and air conditioning equipment) 101 Outdoor unit 102 Indoor unit 102a Alarm display section S Refrigerant detection sensor F Floor

Claims

1. The outdoor unit uses a refrigerant and exchanges heat with outdoor air, water, brine, or a secondary refrigerant. The refrigerant is flammable, The outdoor unit may have a refrigerant detection sensor disposed below a bottom base that forms the bottom surface of a housing of the outdoor unit.

2. 2. The refrigeration air-conditioning apparatus according to claim 1, wherein the refrigerant detection sensor is disposed between the bottom base of the outdoor unit and a floor surface located below the outdoor unit.

3. The refrigeration and air conditioning equipment according to claim 2, characterized in that the refrigerant detection sensor is connected to the control board of the outdoor unit by wire or wirelessly so that its position between the bottom base of the outdoor unit and the floor surface located below the outdoor unit can be adjusted.

4. 4. The refrigeration and air conditioning apparatus according to claim 3, wherein the refrigerant detection sensor is detachably supported at the arrangement position.

5. 4. The refrigeration and air conditioning apparatus according to claim 3, wherein the refrigerant detection sensor and the control board are connected by a signal cable.

6. 6. The refrigeration and air conditioning apparatus according to claim 5, wherein the length of the signal cable is within 2 m.

7. the outdoor unit has a relay terminal portion electrically connected to the control board on the outside of the housing, 6. The refrigeration and air conditioning apparatus according to claim 5, wherein one end of the signal cable is connected to the refrigerant detection sensor, and the other end of the signal cable is electrically and detachably connected to the relay terminal portion.

8. 4. The refrigeration and air conditioning apparatus according to claim 3, wherein the refrigerant detection sensor includes a transmitter that wirelessly transmits a refrigerant detection signal, and the control board wirelessly acquires the refrigerant detection signal transmitted from the refrigerant detection sensor via a receiver.

9. 2. The refrigeration and air conditioning apparatus according to claim 1, wherein a display unit for displaying installation conditions of the refrigerant detection sensor is provided on the outside of the housing of the outdoor unit.

10. The control board is provided with a control unit that controls the air conditioner in an integrated manner, The refrigeration and air conditioning apparatus according to claim 3, wherein the control unit executes a procedure of outputting refrigerant detection information to an alarm display unit of the indoor unit based on the refrigerant detection signal output from the refrigerant detection sensor.

11. The control board is provided with a control unit that controls the air conditioner in an integrated manner, 4. The refrigeration and air conditioning apparatus according to claim 3, wherein the control unit executes a procedure of rotating the outdoor fan for a predetermined time and then stopping the outdoor fan, based on the refrigerant detection signal output from the refrigerant detection sensor.

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