[0028] (First embodiment of the invention)
[0029] figure 1 It is a piping diagram of the refrigerant circuit 10 in the air conditioner 1 according to the first embodiment of the present invention. This air conditioner 1 is a heat pump type air conditioner capable of performing cooling operation and heating operation. Such as figure 1 As shown, the air conditioner 1 has an outdoor unit 100 installed outdoors and an indoor unit 200 installed indoors. The outdoor unit 100 and the indoor unit 200 are connected to each other via the first connection pipe 11 and the second connection pipe 12 to constitute a refrigerant circuit 10 that circulates the refrigerant to perform a vapor compression refrigeration cycle.
[0030]
[0031] The indoor unit 200 is provided with an indoor heat exchanger 210 for exchanging heat between the refrigerant and indoor air. As the indoor heat exchanger 210, for example, a cross-fin type fin-and-tube heat exchanger or the like can be used. In addition, an indoor fan (not shown) is installed in the vicinity of the indoor heat exchanger 210.
[0032]
[0033] The outdoor unit 100 is provided with a compressor 13, an oil separator 14, an outdoor heat exchanger 15, an outdoor fan 16, an expansion valve 17, an accumulator 18, a four-way reversing valve 19, and a refrigerant jacket 20. And the circuit 30, and house them in a casing (an outdoor unit casing 70 described below).
[0034] The compressor 13 sucks the refrigerant from the suction port and compresses it, and discharges the compressed refrigerant from the discharge port. Various compressors such as a scroll compressor can be used as the compressor 13.
[0035] The oil separator 14 separates the refrigerant mixed with lubricating oil discharged from the compressor 13 into refrigerant and lubricating oil, then sends the refrigerant to the four-way switching valve 19 and returns the lubricating oil to the compressor 13.
[0036] The outdoor heat exchanger 15 is an air heat exchanger for exchanging heat between the refrigerant and outdoor air. For example, a transverse fin type fin-and-tube heat exchanger can be used. In the vicinity of the outdoor heat exchanger 15, an outdoor fan 16 that sends outdoor air to the outdoor heat exchanger 15 is provided.
[0037] The expansion valve 17 is connected to the outdoor heat exchanger 15 and the indoor heat exchanger 210, and expands the refrigerant that has flowed in, reduces the pressure to a predetermined pressure, and then flows out. The expansion valve 17 can be constituted by, for example, an electronic expansion valve with a variable opening degree.
[0038] The accumulator 18 performs gas-liquid separation of the refrigerant flowing in, and sends the separated gaseous refrigerant to the compressor 13.
[0039] The four-way reversing valve 19 is provided with four valve ports from the first valve port to the fourth valve port, and can communicate with the second valve port and the fourth valve port while the first valve port communicates with the third valve port. A state ( figure 1 The state shown by the solid line) and the second state where the first valve port is connected to the fourth valve port while the second valve port is connected to the third valve port ( figure 1 Switch between states shown by the dotted line). In this outdoor unit 100, the first valve port is connected to the discharge port of the compressor 13 via the oil separator 14, and the second valve port is connected to the suction port of the compressor 13 via the accumulator 18. In addition, the third valve port is connected to the second connecting pipe 12 via the outdoor heat exchanger 15 and the expansion valve 17, and the fourth valve port is connected to the first connecting pipe 11. In addition, in the outdoor unit 100, the first state is switched when the cooling operation is performed, and the second state is switched when the heating operation is performed.
[0040] The refrigerant jacket 20 is made, for example, by forming a metal such as aluminum into a flat rectangular parallelepiped shape, and covers a part of the refrigerant pipe 21 connecting the outdoor heat exchanger 15 and the expansion valve 17, and is connected to the refrigerant pipe 21 Hot connection. Specifically, in the refrigerant jacket 20, such as figure 2 As shown, there are two through holes into which the refrigerant pipe 21 is embedded. The refrigerant pipe 21 passes through one through hole and is bent into a "U" shape, and then passes through the other through hole. In other words, it can be considered that the refrigerant used in the refrigeration cycle circulates inside the refrigerant jacket 20.
[0041] The circuit 30 controls the rotation speed of the motor of the compressor 13 and the like. The circuit 30 is formed on a printed circuit board 31, and the printed circuit board 31 is fixed in the switch box 40 via a spacer 32. Such as figure 2 As shown, the printed circuit board 31 is provided with a power element 33 and the like. The power element 33 is, for example, a switching element of a direct-to-ac conversion circuit that supplies power to the electric motor of the compressor 13. The power element 33 generates heat when the compressor 13 is operating. If the power element 33 is not pre-cooled, the temperature of the power element 33 is It is possible to exceed the working temperature (for example, 90°C). For this reason, in the air conditioner 1, the power element 33 is cooled by the refrigerant circulating in the refrigerant jacket 20.
[0042] Specifically, in the air conditioner 1, such as figure 2 As shown, the refrigerant jacket 20 is fixed on the switch box 40 to cool the power element 33 in the switch box 40. More specifically, the switch box 40 is formed in the shape of a flat box with one open side, and a through hole 40a is provided on the surface facing the open portion. The heat transfer plate 50 formed in a plate shape is fixed by the mounting screw 51 to cover the through hole. 孔40a. The heat transfer plate 50 is made of a material with low thermal resistance such as aluminum.
[0043] The refrigerant jacket 20 is fixed to the heat transfer plate 50 with mounting screws 51 from the outside of the switch box 40, and the power element 33 is fixed to the heat transfer plate 50 with mounting screws 51 from the inside of the switch box 40. With this structure, the heat of the power element 33 is transferred to the refrigerant jacket 20 via the heat transfer plate 50 and radiates heat to the refrigerant circulating in the refrigerant jacket 20.
[0044] Specifically, during the cooling operation, the refrigerant whose temperature is lower than the temperature of the power element 33 after being condensed in the outdoor heat exchanger 15 flows in the refrigerant jacket 20; during the heating operation, the refrigerant flows in the indoor heat exchanger 210 The refrigerant whose temperature is lower than the temperature of the power element 33 after condensation flows in the refrigerant jacket 20. In the above case, the temperature of the refrigerant flowing in the refrigerant jacket 20 differs depending on the operating conditions, outdoor air conditions, etc., and the temperature of the refrigerant during the cooling operation is approximately 40 to 45°C, for example. For this reason, the heat generated in the power element 33 of the circuit 30 is transferred to the refrigerant jacket 20 via the heat transfer plate 50, and the heat is released to the refrigerant in the refrigerant pipe 21 in the refrigerant jacket 20. Thus, the power element 33 is maintained at an operable temperature.
[0045] image 3 It is a schematic diagram showing the cross-sectional shape of the outdoor unit 100 and shows the layout of main equipment such as the compressor 13. Such as image 3 As shown, the outdoor unit casing 70 is divided into two spaces by a partition 60. In one space (heat exchange chamber), the outdoor heat exchanger 15 having an "L" shape in cross-section is provided facing the side and back of the outdoor unit casing 70, and an outdoor fan is installed near the outdoor heat exchanger 15 16. Also, in another space (machine room), a refrigerant jacket 20, a compressor 13, a switch box 40, and the like are provided. Specifically, on the front side of the outdoor unit casing 70, an opening 71 for operation facing the machine room is provided. When viewed from the opening 71 for operation, the heat transfer plate 50 side of the switch box 40 faces To the front side. In addition, the refrigerant jacket 20 is arranged closer to the front side than the heat transfer plate 50 (that is, closer to the front side than the power element 33) when viewed from the working opening 71.
[0046] -Installation of the switch box 40 into the outdoor unit casing 70-
[0047] In this embodiment, the printed circuit board 31 and the heat transfer plate 50 are mounted on the switch box 40 in advance. Specifically, first, the heat transfer plate 50 is fixed to the switch box 40 with the mounting screws 51. In this state, the printed circuit board 31 is placed in the switch box 40, and the printed circuit board 31 is fixed to the switch box 40 via the spacer 32 On the switch box 40, the power element 33 is fixed on the heat transfer plate 50 with mounting screws 51, so that the power element 33 and the heat transfer plate 50 are thermally connected. For example, when the air conditioner 1 is manufactured or when the printed circuit board 31 is to be mounted again due to repairs or the like, the switch box 40 assembled in this way is placed in the outdoor unit casing 70 from the opening 71 for work.
[0048] Figure 4 It is a front view of the outdoor unit 100. In this example, the outdoor unit casing 70 is provided with a space above the refrigerant jacket 20 through which the switch box 40 can pass, and the working opening 71 is open to this space. Then, the switch box 40 is installed in the outdoor unit casing 70 from the opening 71 for operation. In this case, the switch box 40 is passed over the refrigerant jacket 20, and the switch box 40 is placed at a position farther back than the refrigerant jacket 20. At this time, the side of the heat transfer plate 50 of the switch box 40 is made the front side (that is, the side facing the refrigerant jacket 20). Furthermore, in this state, the refrigerant jacket 20 and the heat transfer plate 50 are fixed with the mounting screws 51.
[0049] At this time, if there is a gap between the refrigerant jacket 20 and the heat transfer plate 50, the heat exchange between the refrigerant jacket 20 and the power element 33 cannot be performed appropriately, and the desired cooling effect cannot be obtained. In this embodiment, the refrigerant jacket 20 is arranged closer to the front side than the power element 33 as seen from the working opening 71, so when the refrigerant jacket 20 and the heat transfer plate 50 are fixed with the mounting screws 51, The connection status of the two can be observed. Therefore, according to this embodiment, it is possible to appropriately connect the refrigerant jacket 20 and the power element 33 at the time of manufacture, repair, etc., to obtain a desired cooling effect.
