JPH11325766A - Evaporative cooling device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an evaporative cooling device, capable of preventing the level of refrigerant from ascending into a condenser and restraining the deterioration of condensing performance of a low-temperature side heat exchanger. SOLUTION: When a bent part 4a is provided in a vapor ascending pipe 4, guiding vapor from an evaporating device 2 into a condenser 3 until the pipe arrives at the highest position H, the bent part 4a is provided without bending the pipe by an angle of 90 deg. or more. Then, liquid refrigerant will not stay in the bent part 4a and is dropped whereby the same is returned into the evaporating device 2. Accordingly, the increase of pressure loss can be restrained and a trouble that the level of refrigerant is ascended into the condenser 3 can be eliminated whereby the whole of the condenser 3 can be used effectively at all times.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a boiling cooling device for cooling the inside of a housing containing a heating element.

[0002]

2. Description of the Related Art As a prior art, for example,
The technique disclosed in Japanese Patent Application Laid-Open No. 119492 is known.
In this boiling cooling device, a boiler and a condenser are annularly connected to form a two-phase natural circulation loop of steam and condensate. According to this, the vapor refrigerant boiled in the boiler flows into the condenser through the vapor riser, and the refrigerant radiated by radiating heat in the condenser returns to the boiler through the liquid return pipe.

[0003]

In some cases, liquid refrigerant is introduced into the vapor riser together with the vapor from the boiler. When the liquid refrigerant accumulates in the bent portion of the vapor riser or the like, the flow of the vapor refrigerant in the vapor riser deteriorates, and the pressure on the high pressure side (steam riser side) of the boiling cooling device rises rapidly. That is, the pressure loss on the high pressure side increases. When the pressure on the high pressure side rises in this way, the pressure difference (head difference) from the low pressure side (liquid return pipe side) increases. Due to the increase in the pressure difference, the liquid level on the low-pressure side of the boiling cooling device rises, and the liquid level of the refrigerant rises inside the condenser. Such a phenomenon is likely to occur when sudden boiling occurs, such as when starting the boiling cooling device or when the heat load suddenly increases during operation. On the other hand, condensers tend to have uneven distribution of vapor to each tube. For this reason, when the liquid level of the refrigerant rises in the condenser, the liquid refrigerant flows into the tube on the side where the amount of vapor distribution is small, and is stabilized in that state, and partially functions as a condenser. It disappears (see FIG. 16).

[0004]

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and an object of the present invention is to prevent a rise in the level of refrigerant in a condenser and reduce the condensation performance of a low-temperature side heat exchanger. It is an object of the present invention to provide a boiling cooling device capable of suppressing the temperature.

[0005]

Means for Solving the Problems [Means of claim 1] By adopting claim 1, the steam riser stands without bending more than 90 ° until it reaches the highest position from the boiler. Since the liquid refrigerant is raised, even if the liquid refrigerant is guided into the vapor riser together with the vapor refrigerant, the liquid refrigerant falls without stagnating at the bent portion and returns to the boiler. As described above, since the liquid refrigerant does not accumulate in the vapor riser, an increase in pressure loss on the high pressure side (the vapor riser side) can be suppressed. As a result, there is no problem that the liquid level of the refrigerant rises in the condenser, and the entire condenser can be used effectively.

According to the second aspect of the present invention, even when the liquid refrigerant is introduced into the vapor riser together with the vapor refrigerant, the bypass pipe connected in the middle of the vapor riser is connected to the vapor riser. To return the liquid refrigerant guided to the boiler,
Liquid refrigerant does not accumulate in the vapor riser. For this reason, an increase in pressure loss on the high pressure side (steam riser tube side) can be suppressed. As a result, there is no problem that the liquid level of the refrigerant rises in the condenser,
The entire condenser can be used effectively.

[0007] According to the third aspect of the present invention, the liquid refrigerant stored in the liquid reservoir can be returned to the evaporator, and the problem that the vapor returns to the evaporator can be suppressed.

According to the fourth aspect of the present invention, the passage of the steam flow can be suppressed by the thin bypass pipe, and the problem that the steam returns to the boiler can be suppressed.

According to the fifth aspect of the present invention, since the interference means provided near the vapor outlet of the boiler blocks the passage of the liquid refrigerant, the liquid refrigerant is supplied to the vapor riser. Ingress is suppressed. For this reason, the liquid refrigerant does not accumulate in the vapor riser, and an increase in pressure loss on the high pressure side (the vapor riser side) can be suppressed. As a result, there is no problem that the liquid level of the refrigerant rises in the condenser, and the entire condenser can be used effectively.

According to the sixth aspect of the present invention, the pressure loss on the high pressure side (steam riser pipe side) increases, and the pressure difference (head difference) from the low pressure side (liquid return pipe side) increases. ) Is increased and the liquid level on the low pressure side rises, but the liquid reservoir suppresses the rise in the liquid level on the low pressure side. As a result, there is no problem that the liquid level of the refrigerant rises in the condenser, and the entire condenser can be used effectively.

According to the seventh aspect of the present invention, the pressure loss on the high-pressure side (steam riser tube side) increases, and the pressure difference (head difference) from the low-pressure side (liquid return tube side) increases. ) Is increased, and even if the liquid level on the low pressure side rises, the liquid return pipe, which meanders or turns and stores a predetermined amount of liquid refrigerant, suppresses the rise in the liquid level on the low pressure side. As a result, there is no problem that the liquid level of the refrigerant rises in the condenser, and the entire condenser can be used effectively.

[0012]

Next, embodiments of the present invention will be described with reference to a plurality of examples. (First Embodiment) FIG. 1 is a refrigerant circuit diagram of a boiling cooling device 1. The boiling cooling device 1 includes a boiler 2 and a casing that are arranged inside a casing (not shown) (for example, a base station of a mobile radio telephone such as a mobile phone, which houses therein a communication device that is a heating element). A condenser 3 disposed outside the body, a pipe (steam riser pipe 4 and a liquid return pipe 5) connecting the boiler 2 and the condenser 3 are provided, and a predetermined amount of refrigerant (for example, H
Freon-based refrigerant such as FC134a) is sealed. In addition, the ebullient cooling device 1 sends an inside air fan 6 (symbol, see FIG. 15) for blowing inside air (having a high temperature due to heat generated by the heating element) to the boiler 2, and sends low temperature outside air to the condenser 3. The inside air fan 6 and the outside air fan 7 are energized by a control circuit (not shown).

The boiler 2 is composed of a plurality of tubes 2a arranged in parallel, upper and lower headers 2b and 2c connected to ends of each tube 2a, and corrugated fins 2d arranged between the tubes 2a. It is composed and brazed integrally, and each component is a metal with excellent heat conductivity (for example,
Aluminum or copper). The condenser 3 is a boiler 2
Similarly, a plurality of tubes 3a and upper and lower headers 3b,
3c and corrugated fins 3d arranged between the tubes 3a, and are integrally brazed.
Each component is made of a metal having excellent heat conductivity (for example, aluminum or copper).

The vapor riser pipe 4 and the liquid return pipe 5 are used by cutting a metal pipe made of, for example, aluminum or the like into a predetermined length, and the vapor riser pipe 4 is generated by the boiler 2 and boiled. The vapor refrigerant collected in the upper header 2b of the vessel 2 is guided into the upper header 3b of the condenser 3. The liquid return pipe 5 guides the liquid refrigerant collected in the lower header 3c of the condenser 3 into the lower header 2c of the boiler 2.

Since the condenser 3 is disposed above the boiler 2, the steam riser 4 is connected to the upper header 2 b of the boiler 2.
At least up to the upper header 3b of the condenser 3 can be started. The steam riser 4 is started without bending beyond 90 ° from the boiler 2 until reaching the highest position H. The steam riser 4 of this embodiment is
It is straightly raised from the upper header 2b of the boiler 2 until it reaches the highest position H.

The operation of the boiling cooling device 1 will be described. In the operation state of the boiling cooling device 1, the high-temperature inside air in the housing is blown to the boiler 2 by the operation of the inside air fan 6, and the outside air fan 7 is
The low temperature outside air is blown to the condenser 3 by the operation of. In the boiler 2, the liquid refrigerant receives heat from high-temperature inside air and boils. The boiled vapor refrigerant is guided from the boiler 2 into the vapor riser 4, rises through the vapor riser 4, and flows into the condenser 3 which is exposed to low-temperature outside air and has a low temperature and a low pressure. The vapor refrigerant flowing into the condenser 3 is deprived of heat by the low-temperature outside air passing through the outside air fan 7 and liquefied and condensed on the inner wall of the tube 3 a of the condenser 3, and drops down by its own weight. The dropped liquid refrigerant descends through the liquid return pipe 5, is returned to the lower part of the boiler 2, and repeats the above cycle. As mentioned above,
By circulating the refrigerant between the boiler 2 and the condenser 3 by repeatedly boiling and condensing the refrigerant, the heat inside the housing can be efficiently discharged to the outside without mixing the high-temperature inside air and the low-temperature outside air, The temperature rise in the housing can be suppressed.

(Effects of the First Embodiment) The steam riser 4 of this embodiment is used for a period from the boiler 2 until the highest position H is reached.
It is launched straight. For this reason, even if the liquid refrigerant is guided into the vapor riser pipe 4 together with the vapor refrigerant, the liquid refrigerant falls without staying in the vapor riser pipe 4 and falls to the evaporator 2.
Returned to As described above, since the liquid refrigerant does not accumulate in the vapor riser 4, an increase in pressure loss on the high pressure side (the vapor riser 4 side) can be suppressed. Therefore, an increase in the pressure difference (head difference) between the high-pressure side and the low-pressure side of the boiling cooling device 1 is suppressed, and the rise in the liquid level on the low-pressure side of the boiling cooling device 1 is suppressed. There is no problem that the liquid level of the refrigerant rises. As a result, the conventional problem (the liquid refrigerant that has risen into the condenser 3 flows into the tube 3a on the side where the amount of vapor distribution is small, stabilizes in that state, and the condensing function is partially lost. No problem), and the entire condenser 3 can always be used effectively.

(Modification of First Embodiment) In the first embodiment described above, an example was described in which the steam riser pipe 4 was started up straight from the boiler 2 until it reached the highest position H. However, due to the arrangement of the boiler 2 and the condenser 3 and restrictions such as the inclination when penetrating the housing, the bent portion 4a is formed in the steam riser pipe 4 from the boiler 2 to the highest position H. It may be necessary to provide one or more. Even in such a case, the steam riser pipe 4 is started up from the boiler 2 without bending beyond 90 ° until reaching the highest position H. That is, as shown in FIG. 2, the bending angle of the bent portion 4a provided from the evaporator 2 to the highest position H is provided so as to exceed 90 °. With this arrangement, there is no problem that the liquid refrigerant stays in the bent portion 4a until reaching the highest position H, and the effect shown in the above embodiment can be obtained.

(Second Embodiment) FIG. 3 is a refrigerant circuit diagram of the boiling cooling device 1. The second embodiment solves the conventional problem by returning the liquid refrigerant that has entered the vapor riser pipe 4 to the boiler 2. Means for returning the liquid refrigerant in the vapor riser pipe 4 to the boiler 2 is a bypass pipe 8, which is provided with a bent portion 4a provided on the way from the boiler 2 to the highest position H, It connects the lower header 2c of the evaporator 2 to the lower header 2c. The bypass pipe 8 is provided sufficiently thinner than the steam riser pipe 4 to prevent a problem that the vapor refrigerant is returned to the boiler 2 via the bypass pipe 8.

(Effect of the Second Embodiment) In the second embodiment, even if the liquid refrigerant is introduced into the vapor riser pipe 4 together with the vapor refrigerant, the liquid refrigerant is supplied by the bypass pipe 8 connected in the middle of the vapor riser pipe 4. Since the refrigerant is returned to the boiler 2, the vapor riser 4
The liquid refrigerant does not stay inside. Therefore, an increase in pressure loss on the high-pressure side of the boiling cooling device 1 is suppressed, and an increase in the pressure difference between the high-pressure side and the low-pressure side is suppressed. It is suppressed, and there is no problem that the liquid level of the refrigerant rises in the condenser 3. As a result, the conventional condenser 3 can be effectively used at all times without occurrence of the conventional trouble.

(Modification of the Second Embodiment) In the second embodiment described above, the lower end of the bypass pipe 8 is connected to the evaporator 2, but as shown in FIG. May be.
In addition, the bypass pipe 8 of the second embodiment has been described as being directed downward from a portion connected to the steam riser pipe 4, but as shown in FIG. May be provided in the horizontal direction.

(Third Embodiment) FIG. 5 is a refrigerant circuit diagram of the boiling cooling device 1. In the third embodiment, a container-like liquid reservoir 9 is provided in the middle of the bypass pipe 8 in order to return only the liquid refrigerant to the boiler 2 by the bypass pipe 8. As shown in FIG. 6, the liquid reservoir 9 separates gas and liquid and guides only the liquid refrigerant into the lower bypass pipe 8. For this reason,
Only the liquid refrigerant stored in the liquid reservoir 9 is returned to the boiler 2 via the lower bypass pipe 8, thereby reliably preventing the vapor refrigerant from returning to the boiler 2 via the bypass pipe 8. be able to. In the third embodiment, the bypass pipe 8 on the upper part of the liquid reservoir 9 is sufficiently thinner than the vapor riser pipe 4 like the bypass pipe 8 on the lower part.

(Modification of Third Embodiment, Part 1) In the third embodiment described above, an example is shown in which the bypass pipe 8 on the upper part of the liquid reservoir 9 is also provided as narrow as the bypass pipe 8 on the lower part. , FIG.
As shown in (2), the bypass pipe 8 above the liquid reservoir 9 may be provided with the same thickness as the vapor riser pipe 4 and only the lower bypass pipe 8 may be provided thin. This facilitates the drop of the liquid refrigerant into the liquid reservoir 9.

(Modification of the Third Embodiment, Part 2) In the third embodiment, the liquid reservoir 9 is arranged in the middle of the bypass pipe 8, but as shown in FIG. May be provided so that the liquid refrigerant in the liquid reservoir 9 is returned to the boiler 2 by the bypass pipe 8.

(Fourth Embodiment) FIG. 9 is a schematic front view of a boiler 2. In the fourth embodiment, the liquid refrigerant is prevented from entering the vapor rise pipe 4, thereby preventing an increase in pressure loss. As means for preventing the liquid refrigerant from entering the vapor riser pipe 4, an interfering means 10 for passing the vapor refrigerant but preventing the liquid refrigerant from passing is used. The interference means 10 shown in the fourth embodiment is, as shown in FIG. 10, a grid arranged at the inlet (steam entrance) of the steam riser 4, and this grid is made of a single or multiple wire mesh. .

(Effect of the Fourth Embodiment) In the fourth embodiment, even if the liquid refrigerant tries to enter the vapor riser 4 together with the vapor refrigerant, the liquid refrigerant passes through the vapor riser 4 by the interference means 10. It is blocked, and only the vapor refrigerant
To enter. As described above, since the liquid refrigerant does not enter the vapor riser 4, the liquid refrigerant does not accumulate in the vapor riser 4, and an increase in the pressure loss on the high pressure side of the boiling cooling device 1 is suppressed. Therefore, an increase in the pressure difference between the high-pressure side and the low-pressure side is suppressed, and the rise in the liquid level on the low-pressure side of the boiling cooling device 1 is suppressed. Absent. As a result, there is no occurrence of the conventional problems,
The entire condenser 3 can always be used effectively.

(Modification of Fourth Embodiment, One of the Sames) In the above-described fourth embodiment, an example in which a lattice is arranged at the entrance of the steam riser pipe 4 is shown as an example of the interference means 10, but FIG. As shown, a louver may be used at the entrance of the vapor riser 4 to block the passage of the liquid refrigerant.

(Modification of Fourth Embodiment, Part 2) In the above fourth embodiment, an example was shown in which the interference means 10 was disposed at the inlet of the steam riser pipe 4. However, as shown in FIG. The interference means 10 (a lattice, a louver, or the like) may be arranged in the upper header 2 b of the vessel 2 so as to prevent the liquid refrigerant from entering the vapor riser 4.

(Fifth Embodiment) FIG. 13 is a refrigerant circuit diagram of the boiling cooling device 1. The fifth embodiment does not prevent the liquid level of the refrigerant from rising in the condenser 3 by suppressing the pressure loss as in the previous embodiments. This prevents the liquid level of the refrigerant from rising in the vessel 3. As the means, in the fifth embodiment,
A liquid reservoir 9 capable of storing a liquid refrigerant is arranged in the middle of the liquid return pipe 5. As shown in FIG. 14, the liquid reservoir 9 has a container shape capable of storing a predetermined amount of liquid refrigerant.
It is preferable to install as high as possible.

(Effect of Fifth Embodiment) In the fifth embodiment, the pressure loss on the high pressure side of the boiling cooling device 1 increases due to a sudden increase in heat load and the like, and the pressure difference from the low pressure side increases. In this case, the liquid level in the liquid return pipe 5 on the low pressure side acts to rise. However, since the liquid refrigerant that increases in the liquid return pipe 5 is stored in the liquid reservoir 9, there is no problem that the liquid level of the refrigerant rises in the condenser 3, and the entire condenser 3 can be used effectively. When the liquid level increasing in the liquid return pipe 5 reaches the liquid reservoir 9, the liquid level in the boiler 2 drops rapidly, and the amount of steam generated in the boiler 2 decreases. As described above, the provision of the liquid reservoir 9 above the liquid return pipe 5 also has a function of alleviating a sudden increase in the steam flow rate.

(Sixth Embodiment) FIG. 15 is a front view of the boiling cooling device 1. In the sixth embodiment, as in the fifth embodiment, even if the pressure loss increases, the liquid level of the refrigerant in the condenser 3 is prevented from rising. As means therefor, in the sixth embodiment, the liquid return pipe 5 above the boiler 2 is meandered or swirled, and the meandering part 5a (or swirling part) is used.
Has a function of a liquid reservoir for storing a predetermined amount of liquid refrigerant. Thus, the effect shown in the fifth embodiment can be obtained.

[Brief description of the drawings]

FIG. 1 is a refrigerant circuit diagram of a boiling cooling device (first embodiment).

FIG. 2 is a refrigerant circuit diagram of a boiling cooling device (a modification of the first embodiment).

FIG. 3 is a refrigerant circuit diagram of a boiling cooling device (second embodiment).

FIG. 4 is a refrigerant circuit diagram of a boiling cooling device (a modification of the second embodiment).

FIG. 5 is a refrigerant circuit diagram of a boiling cooling device (third embodiment).

FIG. 6 is a sectional view of a liquid reservoir (third embodiment).

FIG. 7 is a refrigerant circuit diagram of a boiling cooling device (a modified example of the third embodiment, one of them).

FIG. 8 is a sectional view of a liquid reservoir (a modification of the third embodiment,
Part 2).

FIG. 9 is a schematic front view of a boiler (fourth embodiment).

FIG. 10 is an explanatory view of an interference means (fourth embodiment).

FIG. 11 is an explanatory view of an interference means (a modification of the fourth embodiment, one of them).

FIG. 12 is an explanatory view of an interference unit (a second modification of the fourth embodiment).

FIG. 13 is a refrigerant circuit diagram of a boiling cooling device (fifth embodiment).

FIG. 14 is a sectional view of a liquid reservoir (fifth embodiment).

FIG. 15 is a front view of a boiling cooling device (sixth embodiment).

FIG. 16 is a sectional view of a condenser (explanation of the prior art).

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Boiling cooling device 2 Boiler 3 Condenser 4 Steam riser pipe 4a Bent part 5 Liquid return pipe 5a Meandering part 8 Bypass pipe 9 Liquid reservoir 10 Interference means H Maximum position

Claims (7)

[Claims] 1. A boiling cooling device for cooling an inside of a housing containing a heating element, comprising: a boiler filled with a liquid refrigerant which receives heat from inside air in the housing and boils; and a steam generated by the boiler. A condenser for liquefying and condensing the refrigerant by the outside air outside the housing; a vapor riser for guiding the vapor generated by the boiler to the condenser; and a liquid return for returning the liquid refrigerant liquefied and condensed by the condenser to the boiler. And a pipe, wherein the steam riser is started up without bending more than 90 ° from the boiler until reaching the highest position. 2. A boiling cooling device for cooling an inside of a housing accommodating a heating element, comprising: a boiler filled with a liquid refrigerant which receives heat from inside air in the housing and boils; and steam generated by the boiler. A condenser for liquefying and condensing the refrigerant by the outside air outside the housing; a vapor riser for guiding the vapor generated by the boiler to the condenser; and a liquid return for returning the liquid refrigerant liquefied and condensed by the condenser to the boiler. A boiling cooling device, comprising: a pipe; and a bypass pipe provided in the middle of the vapor riser pipe and returning a liquid refrigerant in the vapor riser pipe to the boiler. 3. The boiling cooling device according to claim 2, wherein a liquid reservoir for storing a liquid refrigerant is disposed in the vapor riser pipe or the bypass pipe. 4. The boiling cooling device according to claim 2, wherein the bypass pipe connected to the boiler or the liquid return pipe is provided to be thinner than the vapor riser pipe. Cooling system. 5. A boiling cooling device for cooling an inside of a housing accommodating a heating element, comprising: a boiler filled with a liquid refrigerant which receives heat from inside air in the housing and boils; and a steam generated by the boiler. A condenser for liquefying and condensing the refrigerant by the outside air outside the housing; a vapor riser for guiding the vapor generated by the boiler to the condenser; and a liquid return for returning the liquid refrigerant liquefied and condensed by the condenser to the boiler. A boiling cooling device comprising: a pipe; and an interference unit provided near a vapor outlet of the boiler and configured to prevent passage of a liquid refrigerant. 6. A boiling cooling device for cooling an inside of a housing containing a heating element, comprising: a boiler filled with a liquid refrigerant which receives heat from inside air in the housing and boils; and a steam generated by the boiler. A condenser for liquefying and condensing the refrigerant by the outside air outside the housing; a vapor riser for guiding the vapor generated by the boiler to the condenser; and a liquid return for returning the liquid refrigerant liquefied and condensed by the condenser to the boiler. A boiling cooling device comprising: a pipe; and a liquid reservoir provided in the middle of the liquid return pipe and capable of storing a predetermined amount of liquid refrigerant. 7. A boiling cooling device for cooling an inside of a housing accommodating a heating element, comprising: a boiler filled with a liquid refrigerant which receives heat from inside air in the housing and boils; and a steam generated by the boiler. A condenser that liquefies and condenses the refrigerant with the outside air outside the housing, a vapor riser that guides the vapor generated by the boiler to the condenser, and returns the liquid refrigerant that has been liquefied and condensed by the condenser to the boiler, And a liquid return pipe capable of storing a predetermined amount of liquid refrigerant by meandering or turning.