JP2001255028A - Freezing cycle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a freezing cycle capable of effectively suppressing the rise of high pressure without discharging a refrigerant to the outside when abnormal rise of the high pressure happens in the freezing cycle using carbon dioxide as the refrigerant. SOLUTION: In a freezing cycle 1 using carbon dioxide as a refrigerant, there are provided an accumulator 7 provided on a high pressure piping 19 for connecting a compressor 2 and a heat radiator, high pressure control means for communicating the high pressure piping 19 and the accumulator 7 and absorbing pressure in the high pressure piping 19 into the accumulator 7 when the pressure in the high pressure piping 19 becomes a first predetermined pressure or higher, and pressure releasing means for communicating the accumulator 7 and the high pressure piping 19 and releasing the pressure in the accumulator 7 into the high pressure piping 19 when the pressure in the high pressure piping 19 becomes predetermined pressure or lower.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a refrigeration cycle using carbon dioxide as a refrigerant for an air conditioner, a refrigerator or the like, and more particularly to a refrigeration cycle having means for absorbing an abnormal pressure rise of a high-pressure refrigerant.

[0002]

2. Description of the Related Art Recently, a refrigeration cycle using carbon dioxide as an alternative refrigerant to CFCs has been attracting attention.
MPa while a (megapascals) about, in the CO ₂ cycle, the maximum pressure for also becomes more 10 MPa, the CO ₂ cycle consideration for high pressure is required than Freon cycle. For this reason, in the conventional cycle, measures such as discharging the refrigerant in the cycle to the outside air when a pressure equal to or more than a certain level is generated in the piping are taken.

[0003]

[Problems to be solved by the invention]

However, as described above, if the refrigerant is discharged to the outside each time a high-pressure abnormality occurs, a shortage of the refrigerant is caused at an early stage, and the refrigerant must be re-injected frequently. Occurs.

[0005] Further, detection and handling of a high-pressure abnormality must be performed in a high-pressure line between the compressor and the expansion means. Therefore, the pressure difference ΔP between the beginning and the end of the high pressure line as shown in FIG.
This pressure difference ΔP is 0.5 MPa depending on the conditions.
Also reach. Therefore, it can be said that detecting and dealing with pressure downstream of the radiator is not a perfect method in that the maximum pressure cannot be detected.

SUMMARY OF THE INVENTION Accordingly, the present invention is to effectively suppress a rise in high-pressure pressure without releasing the refrigerant to the outside when an abnormal rise in high-pressure occurs in a refrigeration cycle using carbon dioxide as a refrigerant. It is an object of the present invention to provide a refrigeration cycle that can perform cooling.

[0007]

In order to solve the above-mentioned problems, in a refrigerating cycle having at least a compressor, a radiator, expansion means, and an evaporator, and using carbon dioxide as a refrigerant, the compressor and the radiator And an accumulator provided on a high-pressure pipe connecting the high-pressure pipe and the high-pressure pipe when the pressure of the high-pressure pipe becomes equal to or higher than a predetermined pressure. The accumulator communicates with the high-pressure pipe to absorb the pressure of the high-pressure pipe. High pressure control means, and pressure releasing means for communicating the accumulator with the high pressure pipe when the pressure of the high pressure pipe becomes equal to or lower than a predetermined pressure, and releasing the pressure in the accumulator to the high pressure pipe. (Claim 1).

According to this, when the refrigerant in the high-pressure pipe from the discharge port of the compressor to the inlet of the radiator becomes higher than the first predetermined pressure for some reason, the high-pressure refrigerant flows into the accumulator, Pressure is absorbed. Then, when the pressure in the high-pressure pipe becomes lower than the predetermined pressure again, the refrigerant in the accumulator is discharged into the high-pressure pipe. Thus, an abnormal increase in the pressure in the high-pressure pipe can be suppressed without releasing the refrigerant to the outside. Since the accumulator plays the role of a damper (buffer) acting at the first predetermined pressure, a sudden pressure increase in the high-pressure pipe can be effectively absorbed. Further, since the accumulator is disposed upstream of the radiator, control can be performed at a place where the refrigerant pressure is highest. In addition, as the high-pressure absorption control means and the pressure release means, a relief (check) valve, a pilot valve, a solenoid valve or the like can be used.

The high-pressure absorption control means includes a closing member for closing a refrigerant inlet of the accumulator communicating with the high-pressure pipe, and a first spring member for urging the closing member in a direction for closing the refrigerant inlet. (Claim 2).

According to this, when the pressure of the high-pressure pipe becomes equal to or higher than the first predetermined pressure, that is, the pressure α of the high-pressure pipe becomes equal to the reference pressure β in the accumulator and the urging pressure γ of the first spring member.
When the state becomes larger than the sum (α> β + γ), the first
Is compressed and the accumulator communicates with the high pressure pipe, and the pressure of the high pressure pipe is released into the accumulator.

The pressure releasing means includes a casing, a moving part slidably disposed in the casing, a spring arrangement space defined between the casing and the moving part, A refrigerant introduction space defined on the opposite side of the spring arrangement space with a second spring member arranged in the spring arrangement space to bias the moving portion in one direction; A first opening communicating with the refrigerant outlet formed in the accumulator, a second opening formed in the casing and communicating with the high-pressure pipe, and a third opening communicating the refrigerant introduction space with the high-pressure pipe. And the moving portion,
The first and second openings are communicated with each other when the moving unit slides toward the refrigerant introduction space, and the first and second openings are communicated when the moving unit slides toward the spring arrangement space. A through passage that moves to a position where communication is not allowed may be formed (claim 3).

According to this, the pressure of the high pressure pipe is reduced to the first pressure.
When the pressure becomes equal to or more than the predetermined pressure, the moving portion opposes the urging force of the second spring member due to the pressure of the refrigerant flowing from the third opening into the refrigerant introduction space defined between the casing and the moving portion. To move to a position where the first opening and the second opening do not communicate with each other, so that the accumulator and the high-pressure pipe do not communicate with each other. At the same time, since the high-pressure absorption control means is open, the refrigerant is stored in the accumulator, and the pressure in the high-pressure pipe decreases. This allows
It is possible to prevent a sudden increase in pressure in the high-pressure pipe.

When the pressure of the high pressure pipe returns to the first predetermined value or less, the moving portion is moved by the urging force of the second spring member to a position where the first opening and the second opening communicate with each other through the through passage. Then, the accumulator and the high-pressure pipe are in communication with each other, and the refrigerant in the accumulator is discharged into the high-pressure pipe.

The pressure releasing means may release the pressure in the accumulator to the high pressure pipe when the degree of superheat of the refrigerant flowing out of the evaporator becomes equal to or higher than a predetermined temperature. 4).

According to this, the refrigerant stored in the accumulator is released not only when the pressure of the high-pressure pipe becomes lower than the first predetermined value but also when the superheat degree of the refrigerant becomes higher than the predetermined temperature. Is done. Thereby, the amount of refrigerant circulating in the cycle increases, and the amount of refrigerant exchanged in the evaporator also increases, so that the degree of superheat of the refrigerant can be reduced.

In addition, a temperature-sensitive cylinder is installed in a pipe between the evaporator and the compressor, and the pressure release means includes a casing, a moving portion slidably disposed in the casing, A spring arrangement space defined between the moving part, a refrigerant introduction space defined on the opposite side of the spring arrangement space across the moving part, and the moving part arranged in the spring arrangement space. A second spring member biasing in a direction, a first opening formed in the casing and communicating with a refrigerant outlet formed in the accumulator, and a second opening formed in the casing and communicating with the high-pressure pipe. An opening, a third opening for communicating the refrigerant introduction space with the high-pressure pipe, and a fourth opening for communicating the temperature sensing cylinder with the spring arrangement space; The moving part is in front of the moving part. The first and second openings communicate with each other when sliding toward the refrigerant introduction space, and move to a position where the first and second openings do not communicate with each other when the moving unit slides toward the spring arrangement space. A through-passage may be formed (claim 5).

According to this, when the degree of superheat of the refrigerant flowing out of the evaporator increases, the refrigerant sealed in the thermosensitive tube expands, and the pressure of the expanded refrigerant is transmitted to the spring arrangement space via the pipe. The moving portion is urged in a direction in which the second spring member is urged, that is, in a direction in which the accumulator communicates with the inside of the high-pressure pipe. As a result, the refrigerant in the accumulator flows out and the amount of circulating refrigerant increases, and the amount of refrigerant flowing through the evaporator increases, so that the degree of superheat decreases. As described above, according to this configuration, when the pressure of the high-pressure pipe becomes equal to or higher than the first predetermined pressure or the degree of superheat of the refrigerant flowing out of the evaporator becomes equal to or higher than the predetermined temperature, the refrigerant (pressure) in the accumulator ) Is released (opened). The temperature-sensitive cylinder and the amount of gas to be sealed are preferably set so that the degree of superheat is about 20 to 30 ° C.

The predetermined pressure is preferably in a range of 10 to 11 MPa.

The CO ₂ cycle tends to have a lower cooling capacity than the CFC cycle. However, as a result of experiments conducted by the inventor, it has been found that a cooling capacity comparable to the CFC cycle can be exerted at around 10 to 11 MPa in a normal use condition. did. Therefore, a high cooling capacity can be maintained by setting the maximum pressure to 10 to 11 MPa.

Further, a pipe connecting the refrigerant outlet of the accumulator and the pressure release means, a leak pipe connecting the high pressure pipe, and a pressure in the high pressure pipe provided on the leak pipe, the pressure in the high pressure pipe being the first pressure A leak valve that opens when the pressure becomes equal to or higher than a second predetermined pressure that is higher than the predetermined pressure (claim 6).
The pressure is preferably in the range of １５15 MPa (claim 7).

Under high load conditions, it may be necessary to further increase the pressure of the high-pressure refrigerant. According to the above configuration, the pressure in the high-pressure pipe is reduced to the first predetermined pressure (10
When the pressure becomes equal to or higher than a second predetermined pressure (13 to 15 MPa) which is a pressure higher than 11 MPa), a leak valve provided on a leak pipe connecting a pipe connecting the accumulator and the pressure release means and the high pressure pipe is opened. Open. As a result, a flow path of high-pressure pipe → leak pipe → accumulator → high-pressure pipe is formed, and the refrigerant accumulated in the accumulator is leaked into the cycle. Thereby, the amount of circulating refrigerant increases, so that a high cooling capacity can be ensured, and local unevenness of the refrigerant can be prevented.

[0022]

Embodiments of the present invention will be described below with reference to the drawings.

A refrigeration cycle 1 according to the first embodiment shown in FIG. 1 is used for an air conditioner, a refrigerator, or the like, circulates carbon dioxide as a refrigerant, and has a compressor 2 for compressing the refrigerant. A radiator 3 for radiating the compressed refrigerant through heat exchange with air, an expansion valve 4 for reducing the pressure of the refrigerant cooled by the radiator 3, and a cooling for evaporating the refrigerant decompressed by the expansion valve 4 and cooling the passing air. And an evaporator 5 are connected in series by piping.

The high-pressure pipe 19 connecting the compressor 2 and the radiator 3 has an accumulator 7 for storing refrigerant and adjusting the pressure, and the refrigerant stored in the accumulator 7 is supplied to the high-pressure pipe 19. And a pressure release valve 8 for discharging the refrigerant to the high-pressure pipe 19 in accordance with the pressure and the degree of superheating of the refrigerant flowing out of the evaporator 5.

A pipe 29 connecting the evaporator 5 and the compressor 2 is filled with a gas such as carbon dioxide as a refrigerant, and the temperature (superheat) of the refrigerant is detected from a change in the volume of the gas. The first temperature sensing tube 10 is installed, and the first temperature sensing tube 10
And the expansion valve 4 are connected through a first pipe 26. Thereby, the opening degree of the expansion valve 4 is adjusted according to the degree of superheating of the refrigerant flowing out of the evaporator 5.

The accumulator 7 shown in FIGS. 2A and 2B includes a casing 15, a first spring 16, and a valve body 17. The casing 15 is formed in a hollow shape, and a refrigerant inlet 15a is provided on a lower surface thereof.
A coolant outlet 15b is formed near the upper end. The first spring 16 has an upper end 16a fixed to an upper surface inside the casing 15, and a lower end 16b fixed to an upper surface of the valve element 17, and presses the valve element 17 downward by a constant pressure. The valve element 17 is provided on the casing 1.
5 is formed in a shape to be fitted to the lower end portion, and the first spring 16 normally closes the refrigerant inlet 15a airtightly. The refrigerant inflow port 15a communicates with a refrigerant inflow pipe 21 connected to the high-pressure pipe 19, and the refrigerant outflow port 15b communicates with a relay pipe 22 connected to the pressure release valve 8 described later. It is preferable that the inner volume of the casing 15 is about 0.5 liter.

The elastic force of the first spring 16 is such that the pressure in the high-pressure pipe 19 is equal to a first predetermined pressure, for example, 10 to 11 MPa.
It is set to be compressed when it becomes a,
During normal operation, as shown in FIG. 2A, the valve 17 closes the refrigerant inlet 15a, but when the pressure in the high-pressure pipe 19 becomes 10 to 11 MPa or more, FIG.
As shown in (b), the valve element 17 moves upward, and the refrigerant flows into the casing 15 from the refrigerant inlet 15a.

The pressure release valve 8 shown in FIGS. 3A and 3B includes a casing 30, a moving portion 31, and a second spring 3.
3 is configured. The casing 30 is formed in a hollow shape, and is provided with an upper surface opening 34, a lower surface opening 35, one side opening 36, and another side opening 37 in upper and lower surfaces and both side surfaces, respectively. The moving portion 31 is disposed in the casing 30 so as to be slidable airtightly to the left and right in the figure, and has a through passage 32 penetrating vertically.
A refrigerant introduction space A and a spring arrangement space B are defined between the inner wall of the casing 30 and the moving part 31 with the moving part 31 interposed therebetween. The second spring 33 is housed in the spring arrangement space B, and one end 33 a of the second spring 33 is connected to the casing 3.
0, on the inner surface where the other side opening 37 is formed,
Further, the other end 33b is fixed to one side surface 31a of the moving section 31, and presses the moving section 31 to the right side in the drawing with a constant pressure.

The upper opening 34 communicates with the relay pipe 22, and the lower opening 35 communicates with the refrigerant outlet pipe 23 connected to the high pressure pipe 19. Further, the one side opening 36 communicates with the high pressure refrigerant introduction pipe 24 (see FIG. 1) having one end connected to the high pressure pipe 19, and the other side opening 37 communicates with a second pipe 27 described later. Communicating.

During normal operation, the moving part 31 is pressed to the right side in the figure by the elastic force of the second spring 33 as shown in FIG. Are in communication with each other through the through path 32. However, when the pressure in the high-pressure pipe 19 becomes equal to or higher than the first predetermined pressure (10 to 11 MPa), FIG.
As shown in (b), the pressure of the refrigerant that has entered the refrigerant introduction space A from the high-pressure refrigerant introduction pipe 24 is increased by the second spring 3.
3, the through passage 32 is shifted to a position where the upper surface opening 34 and the lower surface opening 35 do not communicate with each other.

According to the above configuration, when the pressure in the high-pressure pipe 19 becomes 10 to 11 MPa or more, the valve element 17 of the accumulator 7 opens the first spring 1 as shown in FIG.
6 is compressed and pushed up, and the refrigerant in the high-pressure pipe 19 flows into the casing 15 from the refrigerant inlet 15a. At the same time, the moving part 31 of the pressure relief valve 8
As shown in (b), the second spring 33 is contracted and moved to the left in the figure to close the upper opening 34. Thereby, the refrigerant in the high-pressure pipe 19 is stored in the accumulator 7.

When the pressure becomes lower than 10 to 11 MPa again, the valve element 17 of the accumulator 7 is turned off as shown in FIG.
As shown in FIG. 3A, when the refrigerant is stopped from flowing into the accumulator 7 and the moving part 31 of the pressure release valve 8 is pushed by the second spring 33, as shown in FIG. Moving to the right in the figure, the upper surface opening 34 and the lower surface opening 3
5 is communicated by the through passage 32, so that the refrigerant stored in the accumulator 7 is discharged into the high-pressure pipe 19 through the relay pipe 22.

As a result, it is possible to prevent an abnormal increase in the pressure in the high-pressure pipe 19 without discharging the refrigerant to the outside. Since the accumulator 7 plays a role of a damper (buffer), a sudden increase in pressure in the high-pressure pipe 19 can be effectively absorbed. Further, since the accumulator 7 is arranged on the upstream side of the radiator 3, high pressure control can be performed at a place where the pressure of the refrigerant is highest.

Further, in this embodiment, a pipe 31 connecting the evaporator 5 and the compressor 2 is filled with a gas such as carbon dioxide as a refrigerant, and the temperature of the refrigerant (overheating) Second temperature sensing cylinder 1 for detecting temperature)
The second temperature sensing cylinder 11 is connected to a spring arrangement space B in the pressure release valve 8 through a seventh pipe 27.

Thus, when the degree of superheat of the refrigerant flowing out of the evaporator 5 reaches a predetermined temperature, for example, 25 ° C. or more, the expansion pressure of the gas filled in the second temperature sensing cylinder 11 is applied to the spring arrangement space B. The moving unit 31 moves to the right side in the figure. Thereby, the refrigerant stored in the accumulator 7 is discharged into the pipe, and the amount of refrigerant flowing into the evaporator 5 increases, so that the degree of superheat can be reduced.
The predetermined temperature (set temperature of the degree of superheat) is 20 to 30.
The temperature is preferably about ° C, but should be appropriately changed according to the conditions.

Hereinafter, a second embodiment of the present invention will be described. The same portions as those in the first embodiment and portions having similar functions are denoted by the same reference numerals and the description thereof will be omitted. Omitted.

In the refrigeration cycle 1 according to the second embodiment shown in FIG. 5, the pressure regulator 20 has the accumulator 7, the pressure release valve 8, the leak pipe 40, and the leak valve 41. It is composed.

The leak pipe 40 branches off from the relay pipe 22 connecting the accumulator 7 and the pressure release valve 8,
It is connected to the high pressure pipe 19. The leak valve 41
Is provided on the leak pipe 40 and opens and closes according to the pressure in the high-pressure pipe 19. In this embodiment, the pressure in the high-pressure pipe 19 is the second predetermined pressure of 13 to 15 MPa. It is opened when it becomes the above. As the leak valve 41, a known pressure-operated relief valve, pilot valve, solenoid valve, or the like can be used. Here, the leak valve refrigerant introduction pipe 42 branched from the high-pressure refrigerant introduction pipe 24 leaks. By connecting to the valve 41, the refrigerant pressure in the high-pressure pipe 19 can be detected.

According to the above configuration, when the pressure in the high pressure pipe 19 becomes equal to or higher than the second predetermined pressure (13 to 15 MPa), the leak valve 31 is opened, and the accumulator 7 is connected to the accumulator 7 through the relay pipe 22. The high pressure pipe 19 communicates with the high pressure pipe 19. At this time, the pressure in the high pressure pipe 19 is 10 to 11MP.
a, the valve element 17 in the accumulator 7 is opened as shown in FIG. 2 (b), and the pressure release valve 8 is closed as shown in FIG. 3 (b). become. As a result, the refrigerant stored in the accumulator 7 is leaked to the high-pressure pipe 19, and as a circulation path of the refrigerant from the compressor 2 to the radiator 3, a path passing only through the high-pressure pipe 19, a high-pressure pipe 19 → a leak Tube 40
Two routes are formed, that is, a route passing through the relay pipe 22 → the accumulator 7 → the high-pressure pipe 19.

Under the high load condition of the air conditioner, 10
In some cases, the pressure of the high-pressure refrigerant needs to be increased to 11 MPa (first predetermined pressure) or more, but according to the above configuration, the pressure in the high-pressure pipe 19 is set to be higher than the first predetermined pressure. The second predetermined pressure (13 to 15MP
a) When the above is reached, the leak valve 41 provided on the leak pipe 40 opens. As a result, the amount of circulating refrigerant increases, so that a high cooling capacity can be ensured, and local unevenness of the refrigerant can be prevented.

[0041]

As described above, according to the present invention, it is possible to prevent an abnormal increase in the pressure in the high-pressure pipe without discharging the refrigerant to the outside. In particular, since the accumulator plays a role of a damper (buffer) acting at the first predetermined pressure (10 to 11 MPa), it is possible to effectively absorb a sudden increase in pressure in the high-pressure pipe. In addition, since the accumulator is arranged upstream of the radiator, high pressure control can be performed at a place where the pressure of the refrigerant is highest. Further, since the pressure release valve is opened even when the degree of superheat of the refrigerant becomes too high, an appropriate degree of superheat can be maintained. Further, by providing a means for allowing the refrigerant in the accumulator to leak to the high-pressure pipe when the pressure becomes equal to or higher than a second predetermined pressure (13 to 15 MPa) set higher than the first predetermined pressure, the high-pressure refrigerant under high load conditions is provided. When it is necessary to increase the pressure, the amount of the circulating refrigerant can be increased, so that a high cooling capacity can be ensured and local deviation of the refrigerant can be prevented.

[Brief description of the drawings]

FIG. 1 is a diagram showing a refrigeration cycle according to a first embodiment of the present invention.

FIG. 2A is a sectional view showing an open state of the accumulator according to the embodiment of the present invention.
(B) is a sectional view showing a closed state of the accumulator according to the embodiment of the present invention.

FIG. 3A is a cross-sectional view showing an open state of a pressure release valve according to the embodiment of the present invention, and FIG.
FIG. 2 is a sectional view showing a closed state of the pressure release valve according to the embodiment of the present invention.

FIG. 4 is a graph showing a refrigeration cycle using carbon dioxide as a refrigerant represented on a Mollier diagram.

FIG. 5 is a diagram showing a refrigeration cycle according to a second embodiment of the present invention.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 refrigeration cycle 2 compressor 3 radiator 4 expansion valve 5 evaporator 7 accumulator 8 pressure release valve 15 casing 16 first spring 17 valve element 19 high-pressure pipe 20 pressure control unit 21 refrigerant inflow pipe 22 relay pipe 23 refrigerant outflow pipe 24 High pressure refrigerant introduction pipe 26 First pipe 27 Second pipe 30 Casing 31 Moving part 32 Penetration path 33 Second spring 40 Leak pipe 41 Leak valve 42 Refrigerant introduction pipe for leak valve

Claims (8)

[Claims] At least a compressor, a radiator, an expansion means,
In a refrigeration cycle having an evaporator and using carbon dioxide as a refrigerant, an accumulator provided on a high-pressure pipe connecting the compressor and the radiator, wherein a pressure of the high-pressure pipe is equal to or higher than a first predetermined pressure. When high pressure absorption control means to communicate the high pressure pipe and the refrigerant inlet of the accumulator, When the pressure of the high pressure pipe is equal to or less than the first predetermined pressure, the refrigerant outlet of the accumulator, A refrigeration cycle, comprising: a pressure release means for communicating with the high-pressure pipe. 2. The high-pressure absorption control means includes a closing member that closes a refrigerant inlet of the accumulator, and a first spring member that urges the closing member in a direction in which the refrigerant inlet closes. 2. The method according to claim 1, wherein
Or the refrigeration cycle of 2. 3. The pressure releasing means includes: a casing; a moving portion slidably disposed in the casing; a spring arrangement space defined between an inner wall surface of the casing and the moving portion; A refrigerant introduction space defined on the opposite side of the spring arrangement space across the moving unit, and a second spring member arranged in the spring arrangement space and urging the moving unit toward the refrigerant introduction space, A first opening formed in the casing and communicating with the refrigerant outlet of the accumulator; a second opening formed in the casing and communicating with the high-pressure pipe; and introducing the refrigerant into the casing. A third opening for communicating a space with the high-pressure pipe, wherein the moving part slides toward the refrigerant introduction space and the first and second openings. And communicate with Claim mobile unit, characterized in that the through passage to be moved is formed at a position which does not communicate with the first and second openings when sliding on said spring arrangement space side 1
Or the refrigeration cycle of 2. 4. The pressure release means connects the refrigerant outlet of the accumulator to the high-pressure pipe when the degree of superheat of the refrigerant flowing out of the evaporator becomes equal to or higher than a predetermined temperature. 1. The refrigeration cycle according to 1. 5. A temperature-sensitive cylinder is installed in a pipe between the evaporator and the compressor, wherein the pressure releasing means includes a casing, a moving unit slidably disposed in the casing, and a casing inside the casing. A spring arrangement space defined between a wall surface and the moving unit,
A refrigerant introduction space defined on the opposite side of the spring arrangement space across the moving unit, and a second spring member arranged in the spring arrangement space and urging the moving unit toward the refrigerant introduction space, A first opening formed in the casing and communicating with the refrigerant outlet of the accumulator; a second opening formed in the casing and communicating with the high-pressure pipe; and introducing the refrigerant into the casing. A third opening for communicating a space with the high-pressure pipe; and a fourth opening formed in the casing for communicating the temperature-sensitive cylinder with the spring-arranged space.
The moving part is configured to communicate with the first and second openings when the moving part slides toward the refrigerant introduction space, and the moving part is provided with the spring. 5. A through-path, which is formed to move to a position where the first and second openings are not communicated when slid to the placement space side.
Refrigeration cycle as described. 6. The first predetermined pressure is 10 to 11 MPa.
The refrigeration cycle according to any one of claims 1 to 5, wherein 7. A leak pipe connecting a pipe connecting the refrigerant outlet of the accumulator and the pressure releasing means to the high-pressure pipe, and a pressure in the high-pressure pipe provided on the leak pipe being the pressure in the high-pressure pipe. The refrigeration cycle according to any one of claims 1 to 6, further comprising: a leak valve that opens when the pressure becomes equal to or higher than a second predetermined pressure greater than the first predetermined pressure. 8. The second predetermined pressure is 13 to 15 MPa.
The refrigeration cycle according to claim 7, wherein