JP3400108B2 - Piping device and air conditioner equipped with piping device - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a piping device and an air conditioner equipped with the piping device. The present invention can be applied to, for example, an air conditioner of a system in which a compressor for compressing a refrigerant is driven by an engine.

[0002]

2. Description of the Related Art A conventional technique will be described by taking an engine-driven air conditioner as an example. Conventionally, in an engine driven air conditioner, a variable speed compressor driven by an engine, a four-way switching valve, an outdoor heat exchanger, an expansion valve and a plurality of indoor heat exchangers are arranged in a refrigerant circuit. .

The engine speed control range for driving the compressor is, for example, about 1000 to 2500 rpm.
The ratio of the maximum rotation speed to the minimum rotation speed is about 2-3 times. Therefore, the capacity control range of the compressor is about 2-3 times the minimum capacity. By the way, some operation may be stopped among a some indoor heat exchanger depending on a use condition. In this case, the present applicant has developed an air conditioner of a system in which the rotation speed of the compressor is reduced to reduce the flow rate of the refrigerant supplied to the indoor heat exchanger. In this type of air conditioner, a bypass passage that connects the high-pressure passage portion of the forward passage and the low-pressure passage portion of the return passage is further provided, and an opening / closing valve that opens and closes the bypass passage is provided. When the operation of a part of the indoor heat exchanger is stopped, the bypass passage is opened by opening the on-off valve, whereby the high-pressure and high-temperature gaseous refrigerant is passed through the bypass passage to the low-pressure passage portion of the return passage. I'm going to bring it back.

[0004]

As described above, when the high-pressure and high-temperature gaseous refrigerant is returned to the low-pressure passage portion of the return path through the bypass passage, the high-pressure and high-temperature gaseous refrigerant flows at high speed in the low-pressure passage portion of the return passage. Gush out at. Therefore, an offensive high-frequency sound (for example, 8000 to 20000 Hertz) is apt to be generated, which may impair quietness and comfort.

The present invention has been made in view of the above situation. An object of the present invention is to provide a piping device which is advantageous in reducing or avoiding annoying high-frequency sound when a high-pressure fluid in a high-pressure pipe is ejected to a low-pressure pipe, and ensuring quietness and comfort. Especially. An object of the present invention is to provide an air conditioner equipped with a piping device that is advantageous in reducing or avoiding annoying high-frequency noise when a high-pressure refrigerant is ejected to a low-pressure return path and ensuring quietness and comfort. To do.

[0006]

A piping device according to claim 1 is
A low pressure pipe having a low pressure passage through which a low pressure fluid flows, and a high pressure passage through which a fluid having a higher pressure than the fluid in the low pressure passage flows,
A high-pressure pipe body in which the tip opening of the high-pressure passage communicates with the low-pressure passage,
In the region of the low pressure passage of the low pressure pipe facing the tip opening of the high pressure passage, a mesh body against which the high pressure fluid ejected from the tip opening hits is arranged. As the fluid, a gaseous refrigerant, air, another gas or the like can be adopted.

An air conditioner equipped with the piping device of claim 2 is a compressor for compressing a gaseous refrigerant to a high pressure and a high temperature, and a condenser for condensing and liquefying the high pressure and high temperature gaseous refrigerant compressed by the compressor. And an expander for expanding the liquefied refrigerant in the condenser,
A plurality of evaporators that generate cold heat by evaporating the refrigerant that has passed through the expander, a forward path that sends the refrigerant from the compressor to each evaporator through the condenser and the expander, and return the refrigerant from each evaporator to the compressor. The high-pressure high-temperature gaseous refrigerant compressed by the compressor passes through the main pipe provided with the return path and the high-pressure passage part between the compressor and the condenser in the outward path of the main pipe and the low-pressure passage part of the return path. A bypass passage and an opening / closing valve that is openably and closably provided in the bypass passage are provided, and the tip opening of the bypass passage is formed in a region of the return passage of the main pipe facing the tip opening of the bypass passage. It is characterized in that a net body against which a high-pressure and high-temperature gaseous refrigerant ejected from the jet hits is arranged.

[0008]

According to the present invention, the high-pressure fluid in the high-pressure passage of the high-pressure pipe is jetted from the tip opening toward the low-pressure passage of the low-pressure pipe. At the time of ejection, the high-pressure fluid hits the net body, which reduces or avoids the annoying high-frequency sound that has been conventionally generated. Therefore, it is advantageous to improve quietness and comfort.

In the second aspect, the gaseous refrigerant is compressed by the compressor to a high pressure and high temperature, further reaches the condenser, and is condensed and liquefied by the condenser. Further, the refrigerant that has passed through the condenser expands in the expander to have a low pressure and a low temperature, further flows into the evaporator, takes heat around the evaporator, and evaporates to generate cold heat. In claim 2, when the cooling load is small, the on-off valve is opened and the bypass passage is opened, so that part of the high-pressure and high-temperature gaseous refrigerant compressed by the compressor flows to the condenser. Instead, return directly from the bypass line to the low pressure passage part of the return line of the main pipe. At this time, the high-pressure and high-temperature gaseous refrigerant hits the net,
This reduces or avoids an offensive high-frequency sound that has been conventionally generated.

Therefore, it is advantageous to improve quietness and comfort when the air conditioner is operated. The remaining high-pressure and high-temperature gaseous refrigerant that does not flow through the bypass passage flows through the condenser, expander, and evaporator, and produces cold heat in the evaporator.

[0011]

Embodiments of the present invention will be described below with reference to FIGS. In FIG. 1, the low-pressure pipe body 5 is made of a metal pipe, and has a low-pressure fluid (which can be appropriately selected, for example, 2
It has a low pressure passage 50 through which ~ 6 kg / cm ² ) flows. The low-pressure pipe body 5 includes a small-diameter first pipe body 51, a large-diameter second pipe body 52, and a small-diameter third pipe body 53. The high-pressure pipes 6 are made of metal pipe and are arranged in parallel. The high-pressure pipe body 6 includes a high-pressure passage 60. A fluid having a higher pressure than the fluid in the low pressure passage 50 (which can be appropriately selected, for example, 10 to 60 kg / cm ² ) flows through the high pressure passage 60. High pressure pipe 6
Is connected to the low-pressure pipe body 5 by welding, brazing, etc. Therefore, the tip opening 60a of the high-pressure passage 60 communicates with the low-pressure passage 50.

As shown in FIG. 1, the tip opening 60a has a dimension Δ.
L1 is arranged so as to project into the low pressure passage 50. Here, the high-pressure pipe body 6 is arranged so as to intersect with the low-pressure pipe body 5 in a direction substantially orthogonal thereto. The intersection angle between the high-pressure pipe body 6 and the low-pressure pipe body 5 is not limited to the orthogonal state, and can be appropriately selected. As shown in FIG. 1, a net member 7 is arranged substantially coaxially with the low pressure pipe 5 in a region of the low pressure passage 50 of the low pressure pipe 5 facing the tip opening 60 a of the high pressure passage 60. The mesh member 7 includes a metal ring portion 70 having a double ring,
The metal ring portion 70 is composed of a double ring of stainless steel net 71 whose one end is clamped. Net 71
Has a mesh-shaped cylindrical side wall 71a and a mesh-shaped bottom wall 71b. The mesh of the mesh 71 is about 100 mesh.

In this embodiment, the net member 7 is provided in the second tubular body 52.
After press-fitting, the net member 7 is assembled by squeezing the ends 52f and 52i of the second tubular body 52. By such press-fitting and drawing, the retention of the mesh member 7 is secured.
In this embodiment, the first tubular body 51 is on the upper side and the third tubular body 53 is
Are arranged on the lower side, the metal ring portion 70 is arranged on the upper side, and the net body 71 is arranged on the lower side, but the vertical relationship is not limited to this.

In the present embodiment, the low pressure passage 50 of the low pressure pipe body 5 is provided.
A low-pressure fluid flows in the direction of arrow P1 shown in FIG. A high-pressure fluid flows in the high-pressure passage 60 of the high-pressure pipe 6 in the direction of arrow P2 shown in FIG. Then, the tip opening 6 of the high-pressure pipe 6
A high-pressure fluid is jetted from 0a into the low-pressure passage 50. At this time, the high-pressure fluid hits the side wall 71 a of the net 71 of the net member 7. As a result, the annoying high-frequency sound of “shoe” that has been conventionally generated is reduced. This has been confirmed by testing. The reason is that the occurrence of abnormal turbulence causes the mesh member 7
It is presumed that this is because the mesh body 71 of FIG.

The high-pressure fluid in the high-pressure pipe 6 is the mesh member 7
When hitting the mesh 71, it is considered that the high-pressure fluid passes through the mesh of the mesh 71 or flows around the mesh 71. By the way, when the fluid pressure in the high-pressure passage 60 is high, or when the strength of the mesh 71 is not sufficient, the cylindrical side wall 71a is caused by the ejection of the high-pressure fluid.
Abnormal deformation may occur. In this case, there is a possibility that the effect of the net body 71 for reducing the annoying high frequency sound may be impaired. In this respect, in the present embodiment in which the net body 71 has the bottom wall 71b, since the reinforcing effect of the bottom wall 71b can be expected, the cylindrical shape maintainability of the side wall 71a of the net body 71 is improved, and the net body 71 is improved.
This is advantageous for reducing or avoiding abnormal deformation of the cylindrical side wall 71a. Therefore, it is advantageous to maintain the effect of reducing high-frequency sound that is offensive to the ear for a long period of time.

In addition, as can be seen from FIG. 1, the net member 7
In this embodiment, in which the metal ring portion 70 is arranged on the upstream side and the mesh body 71 is arranged on the downstream side substantially coaxially, in the low pressure passage 50,
Since the smooth flow of the fluid in the
It is even more effective in preventing abnormal deformation of the side wall 71a. Furthermore, according to this embodiment, the dust contained in the fluid is removed from the net member 7
You can expect the effect of collecting by. Therefore, when a collecting member such as a strainer is already installed, the dust collecting effect can be achieved by both the collecting member such as the strainer and the net member 7. Furthermore, if the size of the mesh of the collecting member such as a strainer and the size of the mesh of the mesh member 7 are changed, it is advantageous to collect dust according to the size of each mesh.

The mesh size of the mesh 71 is 1
The number of meshes is not limited to 00 mesh, and can be appropriately selected, such as 50 to 100 mesh, 100 to 150 mesh, 150 to 200 mesh, 200 to 250 mesh, 250 to 300 mesh, 300 to 350 mesh, 350 to 400 mesh, etc. it can. The net 71 has corrosion resistance, heat resistance,
Also, considering the strength and the like, it is formed of stainless steel as described above. Therefore, even if the fluid ejected from the high-pressure passage 60 has a considerably high temperature (for example, 50 to 200 ° C.), it is advantageous for reducing or avoiding the thermal deformation of the net 71.
In this sense as well, it is advantageous to maintain the effect of the net body 71 for reducing annoying high frequency sound. The mesh 71 is not limited to stainless steel, but may be formed of another metal such as aluminum, titanium, or steel, or a hard resin.

In the example shown in FIG. 1, among the large-diameter second pipe bodies 52 constituting the low-pressure pipe body 5, the third pipe body 53 on the downstream side of the inner diameter on the first pipe body 51 side on the upstream side. It is also possible to make the inner diameter of the side slightly smaller. In this case, since the fluid flows in the low pressure pipe body 5 in the arrow P1 direction, the metal ring portion 70 of the mesh member 7 tends to be urged in the arrow P1 direction by the fluid flowing in the arrow P1 direction. It is advantageous to prevent the ring portion 70 from loosening, and the retaining property of the metal ring portion 70 can be secured.

FIG. 3 shows another embodiment of the present invention. The configuration of this example is basically the same as the example shown in FIGS. However, in this example, three high-pressure pipes 6 are arranged in parallel.
Similarly, in the example shown in FIG. 3, it is possible to expect an effect of reducing annoying high frequency sound. (Application example) In FIG. 1, the refrigerant circuit 11 in the engine-driven air conditioner 10 is composed of a main pipe 12. The main pipe 12 functions as a compressor 13, an oil separator 14, a switchable four-way switching valve 15, an outdoor heat exchanger 16 acting as a condenser for condensing a refrigerant (for example, CFC), and an expander for expanding the refrigerant. First expansion valve 17, receiver 18, second expansion valve 1 that also functions as an expander
9. An indoor heat exchanger group 20, which functions as an evaporator for evaporating a refrigerant, a refrigerant-cooling water heat exchanger 21, and an accumulator 22 having a pressure accumulating action are arranged in series.

Of the main pipe 12, the discharge side 1 of the compressor 13
The path from 3a to the indoor heat exchanger group 20 is the outward path 1
It is set to 2A. From the indoor heat exchanger group 20 to the compressor 13
The passage up to the suction side 13b is designated as the return path 12B.
Here, the indoor heat exchanger group 20 is configured by arranging a large number of indoor heat exchangers in parallel. In this example, 3
Although the indoor heat exchangers 20a, 20b, 20c are arranged in parallel, the number is not limited and any number may be used.

The compressor 13 drives the belt 2 by the engine 23.
It is driven via 4 to compress the gaseous refrigerant to a high pressure and high temperature. On the other hand, in order to cool the engine 23, an engine cooling water circuit 25 including a cooling water pipe 26 is provided. In the cooling water pipe 26, the water pump 27, the engine 23, the cooling water-exhaust gas heat exchanger 2
8, a switchable three-way switching valve 29, a refrigerant-cooling water heat exchanger 21, a radiator 30, and a buffer 31 are arranged.

Further, bypass passages 35, 36 and 37 are provided in front of the outdoor heat exchanger 16 in the high pressure passage portion of the outward passage 12A of the main pipe 12. In the bypass passages 35, 36, 37, the bypass valve 3 as an opening / closing valve is provided.
2, 33, 34 are arranged respectively. The bypass valves 32, 33, and 34 have different passage flow rates. Therefore, when the bypass valves 32, 33, 34 are opened, the high-pressure side gaseous refrigerant compressed by the compressor 13 is bypassed by the bypass passage 3.
5, 36 and 37 are supplied in the direction of arrow E1. Although the number of bypass valves is three in this embodiment, the number is not limited and any number may be used.

The operation of the engine-driven air conditioner 10 having the above structure will be described. When the engine 23 is driven and driven based on a user's command or the like, the compressor 13 is driven via the belt 24. First, the cooling mode in which the indoor heat exchanger 20 has a cooling effect will be described. In this case, the refrigerant in the refrigerant circuit 11 is discharged from the discharge side 13a of the compressor 13 to become a high-pressure, high-temperature gaseous refrigerant, and goes through the high-pressure passage portion of the outward path 12A in the arrow A1 direction. Then, it reaches the oil separator 14, and the compressor lubricating oil in the refrigerant is separated. Next, the arrow A2 is passed through the four-way switching valve 15.
Is sent to the outdoor heat exchanger 16. In the outdoor heat exchanger 16, a high-pressure and high-temperature fluid refrigerant (for example, 10 to 10) is used.
30 kg / cm ² , 60 to 110 ° C) is condensed and liquefied by releasing heat to the outside air. Further, the refrigerant is arrow A
Heading in three directions, the first expansion valve 17, the receiver 18, the second
By passing through the expansion valve 19, the liquid refrigerant rapidly expands,
It becomes a low-temperature low-pressure atomized refrigerant. Further, the refrigerant flows into the indoor heat exchangers 20a to 20c of the indoor heat exchanger group 20 in the arrow A4 direction. The mist-like refrigerant that has flowed into the indoor heat exchanger group 20 robs the heat of the surroundings of the indoor heat exchanger group 20 and evaporates to generate cold heat. That is, cooling is performed here.

Further, the low-pressure low-temperature gaseous refrigerant (for example, ² to 6 kg / cm ² , 0 ° C.) that has passed through the indoor heat exchanger group 20 flows in the directions of arrow A5 and arrow A6, and passes through the four-way switching valve 15 and arrow A7. Direction, and further the refrigerant-cooling water heat exchanger 21
To the suction side 13b of the compressor 13 through the accumulator 22 and the arrow A9 direction. Then, the refrigerant is compressed again in the compressor 13 and flows as described above.

In the cooling mode described above, the engine cooling water is discharged from the water pump 27 and the engine 2 is discharged.
3 and the cooling water-exhaust gas heat exchanger 28 to cool the engine 23, and then the radiator 3 is operated by the three-way switching valve 29.
0, flows through the buffer 31 and returns to the water pump 27 again. Therefore, due to the switching action of the three-way switching valve 29, the refrigerant-
The engine cooling water does not flow into the cooling water heat exchanger 21, and therefore, in the cooling mode described above, the refrigerant-cooling water heat exchanger 2
In the case of 1, no heat exchange effect occurs.

Next, the heating mode in which the indoor heat exchanger group 20 has a heating effect will be described. In the heating mode, the four-way switching valve 15 is switched to the form shown by the arrow K in FIG.
Even in the heating mode, the refrigerant is compressed by the compressor 13 to become a high-pressure and high-temperature gaseous refrigerant, and the discharge side 13a of the compressor 13
The oil for compressor lubrication in the refrigerant is separated by the oil separator 14. In this heating mode, the four-way switching valve 15 is switched to the form shown by the arrow K in FIG. 4 by the electronic control unit, so that the high-pressure high-temperature gaseous refrigerant passes through the four-way switching valve 15 in the direction of the arrow B1 and then the arrow B2. Flows in the direction and reaches the indoor heat exchanger group 20. Then, in the indoor heat exchanger group 20, the high-pressure and high-temperature gaseous refrigerant is condensed to release heat into the room to be liquefied and become a high-pressure and high-temperature liquid refrigerant. That is, in the heating mode, the indoor heat exchanger group 20 functions as a condenser and heating is performed. Further, the refrigerant is the arrow B3.
Direction and the direction of arrow B4 and passing through the second expansion valve 19, the receiver 18, and the first expansion valve 17, the liquid refrigerant expands and becomes a low-temperature low-pressure atomized refrigerant. Then, in the outdoor heat exchanger 16, the refrigerant evaporates to receive heat from the outside air and become a low-temperature low-pressure gaseous refrigerant. That is, in such a heating mode, the outdoor heat exchanger 16 acts as an evaporator. The refrigerant that has passed through the outdoor heat exchanger 16 heads in the direction of arrow B5, reaches the refrigerant-cooling water heat exchanger 21 through the four-way switching valve 15, and
It returns to the suction side 13b of the compressor 13 via the accumulator 22.

In such a heating mode, the refrigerant-cooling water heat exchanger 21 operates. That is, the engine cooling water is discharged from the water pump 27 and the engine 23 and the cooling water-
After flowing through the exhaust gas heat exchanger 28 to cool the engine 23 to a high temperature, the three-way switching valve 29 moves in the direction of arrow C1, flows through the refrigerant-cooling water heat exchanger 21 in the direction of arrow C2, and again. Return to the water pump 27. The engine cooling water having such a high temperature passes through the refrigerant-cooling water heat exchanger 21 and exchanges heat with the refrigerant by the heat exchanger 21 to heat the refrigerant, which can further contribute to the improvement of the heating capacity.

By the way, in both the cooling mode and the heating mode, the number of operating indoor heat exchangers 20a, 20b, 20c can be arbitrarily set according to the usage condition of the room. In this case, the indoor heat exchanger 20a,
By operation switches provided on 20b and 20c. In this case, the amount of refrigerant flowing into the indoor heat exchanger group 20 must be variably controlled depending on the number of operating units. Therefore,
The open / closed states of the bypass valves 32, 33 and 34 are controlled by the electronic control device (not shown) or the like as follows.

Bypass valves 32, 33, 34 are all closed Bypass valve 32 only Open bypass valve 33 only Open bypass valve 34 only Open bypass valves 32, 33 only Open bypass valves 32, 34 only Open bypass valves 33, 34 only Open bypass As a matter of course, all the valves 32, 33, 34 are opened, and the amount of the refrigerant bypassed to the bypass passages 35, 36, 37 increases toward the direction, and the amount of the refrigerant flowing into the indoor heat exchanger group 20 decreases. To go.

In the example shown in FIG. 4, the amount of refrigerant flowing to the indoor heat exchanger group 20 can be variously changed by opening / closing the bypass valves 32, 33, 34 having different passage flow rates. An appropriate amount of the refrigerant can be supplied to the indoor heat exchanger group 20 according to the change in the operating number of the group 20. Even when the number of operating indoor heat exchanger groups 20 fluctuates in this way, the refrigerant flowing into the indoor heat exchanger groups 20 does not become excessive, so problems such as abnormal pressure in the refrigerant system do not occur.

By the way, W in FIG. 4 shows a merging portion where the high-pressure and high-temperature gaseous refrigerant flowing through the bypass passages 35, 36, 37 joins the low-pressure passage portion of the return passage 12B. The merging can be performed in both the cooling mode and the heating mode. Bypass passages 35, 36, 37 described above
Since the gaseous refrigerant compressed by the compressor 13 flows,
High pressure and high temperature. That is, when the bypass valve 32 is open, the high-pressure and high-temperature gaseous refrigerant in the bypass passage 35 flows in the direction of the arrow E1 and then flows into the low-pressure side return passage 12B via the junction W. Further, when the bypass valve 33 is open, the high-pressure and high-temperature gaseous refrigerant in the bypass passage 36 flows in the direction of the arrow E1, passes through the joining portion W, and the return passage 12B on the low-pressure side.
Flow to. When the bypass valve 34 is open, the high-pressure and high-temperature gaseous refrigerant in the bypass passage 37 flows in the direction of the arrow E1 and then flows into the return passage 12B on the low-pressure side via the merging portion W.

The merging portion W is equipped with the mesh member 7 shown in FIG. That is, in the low-pressure passage of the return passage 12B as the low-pressure pipe body, the mesh member 7 is provided in the area facing the tip openings of the bypass passages 35 and 36 in the form shown in FIG. And bypass passages 35, 3
The high-pressure and high-temperature gaseous refrigerant ejected from the front end opening of 6 hits the mesh member 7. Therefore, similarly to the above, it is advantageous for reducing or avoiding the high frequency sound generated by the ejection of the high-pressure and high-temperature gaseous refrigerant.

[Brief description of drawings]

FIG. 1 is a vertical cross-sectional view of a main part of a piping device.

FIG. 2 is a perspective view of a mesh member.

FIG. 3 is a vertical cross-sectional view of a main part of a piping device.

FIG. 4 shows a configuration diagram of an engine-driven air conditioner.

[Explanation of symbols]

In the figure, 5 is a low pressure pipe, 50 is a low pressure passage, 6 is a high pressure pipe,
60 is a high pressure passage, 7 is a mesh member, 71 is a mesh, 13 is a compressor, 16 is an outdoor heat exchanger (condenser), 17 is an expansion valve,
Reference numeral 19 is an expansion valve (expander), 20a to 20c are indoor heat exchangers (evaporators), 32 to 34 are bypass valves, and 35 to 37 are bypass passages.

─────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP 62-166270 (JP, A) JP 60-236825 (JP, A) Actually open 4-113859 (JP, U) Actually open 56- 018871 (JP, U) Actually open 59-139875 (JP, U) Actually open 61-74624 (JP, U) (58) Fields investigated (Int.Cl. ⁷ , DB name) F25B 41/00 F25B 1 / 00

Claims (2)

(57) [Claims] 1. A low-pressure pipe having a low-pressure passage through which a low-pressure fluid flows, and a high-pressure passage through which a fluid having a higher pressure than the fluid in the low-pressure passage flows, and a tip opening of the high-pressure passage communicates with the low-pressure passage. In the high-pressure pipe body, and in the low-pressure passage of the low-pressure pipe body, in a region facing the tip opening of the high-pressure passage, a mesh body against which the high-pressure fluid ejected from the tip opening of the high-pressure passage hits is arranged. Characteristic piping device. 2. A compressor for compressing a gaseous refrigerant to a high pressure and high temperature, a condenser for condensing and liquefying the high pressure and high temperature gaseous refrigerant compressed by the compressor, and a refrigerant liquefied by the condenser. An expander that expands; a plurality of evaporators that evaporate the refrigerant that has passed through the expander to generate cold heat; and a forward path that sends the refrigerant from the compressor to the evaporator through the condenser and the expander. A main pipe having a return path for returning the refrigerant from each of the evaporators to the compressor; a high-pressure passage portion between the compressor and the condenser and a low-pressure passage portion of the return passage in the outward passage of the main pipe. A low-pressure passage on the return passage of the main pipe, which is in communication with the bypass passage through which a high-pressure and high-temperature gaseous refrigerant compressed by the compressor passes and an opening / closing valve provided on the bypass passage so as to be opened and closed. In the region of the portion facing the tip opening of the bypass, the tip of the bypass is An air conditioner equipped with a piping device, in which a net body against which a high-pressure and high-temperature gaseous refrigerant ejected from an opening hits is arranged.