JP2002146454A - Heat transfer tube for antifreezing solution and refrigerator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To increase the corrosion resistance of heat transfer tubes with antifreezing solution circulated at the insides and to prolong the service life of a refrigerator. SOLUTION: The refrigerator is provided with pressure resistant vessels 6, heat transfer tubes 8 arranged at the insides of the pressure resistant vessels 6, hydrogen storage alloys 12 charged to the insides of the pressure resistant vessels 6 in a state of being heat-exchangeable with the heat transfer tubes 8 and antifreezing solution circulation mechanisms 22, 24 and 34 to 40 circulating antifreezing solution through the heat transfer tubes. The heat transfer tube 8 is formed of a copper alloy containing one or more kinds of elements selected from Cr, Zr, Ti, Mg, Ni, Fe, Co, Si, Al, Sn, P and Zn by 0.01 to 10 wt.%. The average crystal grain size of the copper alloy is controlled to 3 to 30 μm, thermal conductivity to 0.5 to 0.9 cal/cmsec deg.C, and proof stress to >=10 kg/mm2.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a refrigeration system using a hydrogen storage alloy, a heat transfer tube for antifreeze used in the refrigeration system, and a method for manufacturing the same.

[0002]

2. Description of the Related Art Since a hydrogen storage alloy has a characteristic of generating heat when absorbing hydrogen and absorbing heat when releasing hydrogen, a refrigerating apparatus utilizing this characteristic has recently been proposed.

In this type of refrigeration apparatus, for example,
As described in Japanese Patent Application Publication No. 196499, a heat transfer tube is disposed inside a pressure-resistant container to which hydrogen gas is supplied, radiation fins are attached to the heat transfer tube, and the pressure-resistant container is filled with hydrogen storage alloy powder. The structure is adopted. Then, after absorbing the hydrogen gas into the hydrogen storage alloy in the pressure vessel, the pressure in the tank is reduced to release the hydrogen gas from the hydrogen storage alloy, and the heat absorbed at this time cools the refrigerant flowing in the heat transfer tube. The refrigerant is used to cool the freezer.

[0004]

Incidentally, an antifreeze such as an aqueous solution of methyl alcohol is generally used as a refrigerant so as not to freeze in the heat transfer tube. On the other hand, a phosphorus deoxidizer having a high thermal conductivity is used as a heat transfer tube. Copper or the like is used.

However, in the refrigeration apparatus having the above-mentioned structure, no problem occurs particularly when the circulation speed of the antifreeze is low. From this, it was found that the phenomenon that copper gradually eluted into the antifreeze became remarkable, and the thickness of the heat transfer tube became small, causing a problem in pressure resistance. This is particularly noticeable when fine fins are formed on the inner surface of the heat transfer tube to obtain the effect of stirring the antifreeze, and it is difficult to form fins on the inner surface of the heat transfer tube. there were.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a technique capable of improving the corrosion resistance of a heat transfer tube through which antifreeze is circulated and extending the life of a refrigeration system.

[0007]

In order to solve the above-mentioned problems, an antifreeze heat transfer tube according to the present invention comprises Cr, Zr, T
i, Mg, Ni, Fe, Co, Si, Al, Sn, P,
One or more elements selected from Zn
It is formed of a copper alloy containing 1 to 10 wt%, the average grain size of the copper alloy is 3 to 30 μm, and the thermal conductivity is 0.1 to 10 wt%.
The temperature is 5 to 0.9 cal / cmsec ° C, and the proof stress is 10 kg / mm ² or more.

Further, the refrigeration apparatus according to the present invention is characterized in that the pressure vessel, a heat transfer tube disposed inside the pressure vessel, and the heat transfer tube are filled in the pressure vessel in a heat exchangeable state. A hydrogen storage alloy, and an antifreeze circulating mechanism for circulating an antifreeze through the heat transfer tube, wherein the heat transfer tube comprises Cr, Z
r, Ti, Mg, Ni, Fe, Co, Si, Al, S
It is formed of a copper alloy containing 0.01 to 10% by weight of one or more elements selected from n, P, and Zn. The copper alloy has an average crystal grain size of 3 to 30 μm or less, and has a thermal conductivity of Is 0.5 to 0.9 cal / cmsec ° C and the proof stress is 1
0 kg / mm ² or more.

Further, the method for manufacturing a heat transfer tube according to the present invention comprises:
r, Zr, Ti, Mg, Ni, Fe, Co, Si, A
a copper alloy containing 0.01 to 10 wt% or less of one or more elements selected from l, Sn, P, and Zn;
A step of heating to 750 to 950 ° C. to perform hot rolling, and repeating the cold rolling of the hot-rolled copper alloy by 70% or more and annealing at 500 to 750 ° C. a plurality of times. Forming the material, and applying the plate material to 450-70.
A step of heating to 0 ° C. to temper the Vickers hardness (Hv) to be 90 or less; and a step of forming a heat transfer tube by subjecting the plate material to electric resistance welding.

[0010]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing a refrigeration apparatus according to one embodiment of the present invention. This refrigerator has 4
The pressure-resistant containers 1, 2, 4, and 6 are provided, and the heat-transfer tubes 8 are arranged in a meandering state in the pressure-resistant containers 1, 2, 4, and 6, respectively. A large number of radiating fins 10 are vertically mounted on the outer periphery of the heat transfer tube 8,
4 and 6, the hydrogen storage alloy powder 12 is
It is filled up between. The pressure-resistant containers 1 and 2 are connected by a hydrogen gas passage 14, and the pressure-resistant containers 4 and 6 are connected by a hydrogen gas passage 16.

One end of the heat transfer tube 8 in the pressure vessel 1 is connected to one end of a hot water circulation path of the boiler 18 via a three-way valve 26, and the other end of the heat transfer tube 8 is connected to the boiler 18 via a three-way valve 28. Is connected to the other end of the hot water circulation path. Therefore, by operating the three-way valves 26 and 28, the hot water (for example, 150 ° C.) heated by the boiler 18 is supplied to the pressure vessel 1
The hydrogen storage alloy powder 12 in the pressure-resistant container 1 can be heated by circulating through the heat transfer tube 8 in the inside.

One end of a heat transfer tube 8 in the pressure vessel 4 is connected to one end of a cooling water circulation path of a cooling tower (cooling tower) 20 via a three-way valve 30, and the other end of the heat transfer tube 8 is connected via a three-way valve 32. And connected to the other end of the cooling water circulation path of the cooling tower 20. Therefore, by operating the three-way valves 30 and 32, the cold water cooled in the cooling tower 20 (for example, 20 to
35 ° C.) can be circulated through the heat transfer tube 8 in the pressure-resistant container 4.

The third port of the three-way valve 26 is connected to the end of the heat transfer tube 8 in the pressure vessel 4 on the side of the three-way valve 30, and the third port of the three-way valve 28 is connected to the three-way of the cooling water circuit of the cooling tower 20. It is connected to the end on the valve 32 side. Thereby, the three-way valves 26 and 28
, The hot water heated by the boiler 18 can be circulated to the heat transfer tube 8 in the pressure vessel 4 instead of the pressure vessel 1.

The third port of the three-way valve 30 is connected to the end of the heat transfer tube 8 in the pressure vessel 1 on the side of the three-way valve 26, and the third port of the three-way valve 32 is connected to the three-way of the hot water circulation path of the boiler 18. It is connected to the end on the valve 28 side. Thereby, the three-way valves 30, 32
, The cold water cooled by the cooling tower 20 can be circulated not to the pressure vessel 4 but to the heat transfer tube 8 in the pressure vessel 1. Pressure vessels 1 and 4, boiler 1
High pressure water is generally circulated through the cooling tower 8 and the cooling tower 20, but other liquid heating media can be used in the present invention.

On the other hand, each of the heat transfer tubes 8 in the pressure-resistant containers 2 and 6 is
The refrigerant circulation path of the cooling tower 22 and the refrigerant circulation path of the freezer 24 are connected via four-way valves 34, 36, 38, and 40 in the state shown in FIG. Thereby, the four-way valves 34, 3
By appropriately operating 6, 38, and 40, the refrigerant (for example, 20 to 35 ° C.) cooled in the cooling tower 22 is circulated to one of the heat transfer tubes 8 of the pressure-resistant containers 2 and 6, and returned from the freezer 24. Refrigerant (for example, −20 ° C.)
Can be circulated to the other heat transfer tube 8.

Further, by employing the four-way valves 34, 36, 38, and 40, the direction of the flow of the refrigerant in each heat transfer tube 8 can be reversed. As the coolant, an antifreeze such as an aqueous solution of methyl alcohol or ethyl alcohol (for example, 30 vol%) or an aqueous solution of ethylene glycol (for example, 45 vol%) is used as described later. This is because the inside of the heat transfer tube 8 in the pressure vessel on the cooling side is cooled down to about −20 ° C.

A method for performing freezing by the above-described apparatus will be described. Now, it is assumed that the hydrogen storage alloy powder 12 in the pressure container 1 is heated to a high temperature and discharges hydrogen, and the hydrogen storage alloy powder 12 in the pressure container 2 is in a state where hydrogen is absorbed. From this state, the water cooled in the cooling tower 20 is circulated to the heat transfer tube 8 in the pressure vessel 1, and the hydrogen storage alloy powder 12
Is cooled from a high temperature state, the hydrogen storage alloy powder 12 in the pressure-resistant container 1 starts absorbing hydrogen in the pressure-resistant container 2, and the hydrogen storage alloy powder 12 in the pressure-resistant container 2 is cooled below freezing by releasing hydrogen. You. When the hydrogen storage alloy powder 12 in the pressure-resistant container 2 is sufficiently cooled, the antifreeze is circulated between the hydrogen storage alloy powder 12 and the freezer 24 to cool the freezer 24.

On the other hand, in parallel with this, a regeneration operation for returning hydrogen transferred from the pressure-resistant container 6 to the pressure-resistant container 4 by the previous freezing operation to the pressure-resistant container 6 is performed. For that purpose, the hot water heated by the boiler 18 is caused to flow to the heat transfer tube 8 in the pressure-resistant container 4, and the hydrogen storage alloy powder 12 is heated to release hydrogen. The released hydrogen is absorbed by the hydrogen storage alloy powder 12 in the pressure-resistant container 6 through the hydrogen gas passage 16, and the hydrogen storage alloy powder 12 in the pressure-resistant container 6 also generates heat. In order to suppress this heat generation, the refrigerant cooled in the cooling tower 22 is circulated through the heat transfer tube 8 in the pressure-resistant container 6 so that the movement of the hydrogen gas from the pressure-resistant container 4 to the pressure-resistant container 6 is continued.

Eventually, when the hydrogen occlusion alloy powder 12 in the pressure-resistant container 2 completely releases the occluded hydrogen and the hydrogen storage alloy powder 12 in the pressure-resistant container 6 has sufficiently occluded hydrogen, the valves 26 to 40 To reverse all flows.

That is, the water cooled in the cooling tower 20 is circulated to the heat transfer tube 8 in the pressure vessel 4, and the hydrogen storage alloy powder 1
2 is cooled from a high temperature state, the hydrogen storage alloy powder 12 in the pressure vessel 4 starts absorbing hydrogen in the pressure vessel 6, and the hydrogen storage alloy powder 12 in the pressure vessel 6 releases hydrogen to cool below freezing. Is done. When the hydrogen storage alloy powder 12 in the pressure-resistant container 6 is sufficiently cooled, the antifreeze is circulated between the hydrogen storage alloy powder 12 and the freezer 24 to cool the freezer 24.

On the other hand, in parallel with this, a regeneration operation for returning hydrogen transferred from the pressure-resistant container 2 to the pressure-resistant container 1 by the previous freezing operation to the pressure-resistant container 2 is performed. For that, boiler 1
The hot water heated in 8 is passed to the heat transfer tube 8 in the pressure vessel 1,
The hydrogen storage alloy powder 12 is heated to release hydrogen. The released hydrogen passes through the hydrogen gas passage 14 and is absorbed by the hydrogen storage alloy powder 12 in the pressure-resistant container 2.
The hydrogen storage alloy powder 12 inside also generates heat. In order to suppress this heat generation, the refrigerant cooled in the cooling tower 22 is circulated through the heat transfer tube 8 in the pressure vessel 2 so that the transfer of hydrogen gas from the pressure vessel 1 to the pressure vessel 2 is continued. By repeating the above steps, the freezer 24 can be continuously cooled.

FIG. 2 is a sectional view showing details of the pressure vessels 1, 2, 4, and 6. The pressure-resistant containers 1, 2, 2 of this embodiment
Reference numerals 4 and 6 each have a cylindrical shape with both ends closed, and the heat transfer tubes 8 are arranged in a meandering manner. Although only a single flow path is formed by the heat transfer tube 8 in FIG.
A plurality of flow paths may be formed in the inside, and these flow paths may be connected in parallel.

FIG. 3 is an enlarged sectional view showing a fixed state of the radiation fin 10 and the heat transfer tube 8. The radiating fin 10 is a thin metal plate formed of aluminum or the like.
Is formed, and an annular flange portion 10B having a constant height is formed around the hole 10A. The heat transfer tube 8 is fixed to the inner surface of the hole 10A by being passed through the hole 10A, and having an outer diameter enlarged by inserting a tube expansion plug therein.
The distance between the radiation fins 10 is the same as that of the flange portion 10B.
Are in contact with the adjacent heat radiation fins 10. Although the interval between the radiation fins 10 is not limited in the present invention, it is preferably about 1 to 5 mm.

The material of the hydrogen storage alloy powder 12 is not limited in the present invention. For example, a powder of a lanthanum-nickel hydrogen storage alloy such as LaNi ₅ can be used. According to this type of lanthanum-nickel-based hydrogen storage alloy, it is possible to store about 1000 times by volume and about 1.5 wt% by weight of hydrogen gas.

The hydrogen storage alloy powder 12 having a high equilibrium temperature is used as the hydrogen storage alloy powder 12 in the pressure-resistant containers 1 and 4 on the relatively high temperature side.
It is preferable that a hydrogen storage alloy having a low equilibrium temperature be used as the hydrogen storage alloy powder 12 therein.

The main feature of the present invention lies in the material of the heat transfer tube 8. The heat transfer tubes 8 used in this embodiment are all Cr, Zr, Ti, Mg, Ni, Fe, Co, S
one or two selected from i, Al, Sn, P, Zn
The alloy contains 0.01 to 10% by weight of at least one kind of element, and the remainder is formed of copper and a copper alloy which is an unavoidable impurity. The average crystal grain size of the copper alloy is 3 to 30 μm, and the thermal conductivity is 0.5 to
0.9 cal / cmsec ° C and proof stress is 10 kg / mm ² or more.

When the content of the element is less than 0.01 wt%, a sufficient amount of precipitates do not precipitate in the copper alloy, the corrosion resistance of the heat transfer tube 8 cannot be sufficiently increased, and erosion due to the antifreeze cannot be suppressed. . On the other hand, when the content of the element is 1
If it is higher than 0 wt%, the precipitate concentration will be too high and the workability of the copper alloy will deteriorate, making it difficult to form the heat transfer tube 8. In particular, it becomes extremely difficult to roll fins (see fins 50 in FIGS. 4 and 5) on the inner surface of the heat transfer tube 8. The content of the element is more preferably 0.05 to 3 w
t%.

It is actually difficult to reduce the average crystal grain size of the copper alloy forming the heat transfer tube 8 to less than 3 μm.
When it is larger than m, the precipitation hardening effect becomes poor, and the corrosion resistance of the heat transfer tube 8 also decreases. More preferably, the average crystal grain size of the copper alloy is 4 to 20 μm.

When the heat conductivity of the copper alloy forming the heat transfer tube 8 is less than 0.5 cal / cmsec ° C., the heat exchange efficiency of the heat transfer tube 8 decreases. The thermal conductivity of the copper alloy is 0.9
It is actually difficult to exceed cal / cmsec ° C.
Further, when the proof stress of the copper alloy is less than 10 kg / mm ² , the strength of the heat transfer tube 8 is insufficient, which is not preferable.

In the copper alloy forming the heat transfer tube 8, precipitates are separated.
Preferably, the alloy is a dispersed precipitation hardening alloy. Precipitate
Preferably has an average particle size of 0.01 to 0.3 μm.
And more preferably 0.02 to 0.15 μm.
If the thickness is less than 0.01 μm, the hardness becomes too high and the workability and
And the moldability decreases. On the other hand, if it is larger than 0.3 μm,
10 kg / mm proof stress required for the invention^TwoIs difficult to obtain
Not only that, it also has a bad effect on the fatigue properties. In copper alloy
The dispersion density of the precipitates is 10⁸Pieces / mm^Two-10 ¹²Pieces/
mm^TwoIt is preferred that To form precipitates
More preferred elements added to the copper alloy are:
One type selected from Cr, Zr, Ni, Fe, Co, and P
Or two or more elements, in which case the strength and heat transfer
It is a material with excellent conductivity and excellent erosion resistance.
Thus, the effect of preventing local corrosion is further enhanced.

The copper alloy has moderate strength and good thermal conductivity, is excellent in workability, and has a good balance of properties. Further, by the above-mentioned dispersed state of the precipitates, grain growth can be suppressed, the structure can be refined, and pitting corrosion resistance (local corrosion resistance) can be improved. Further, at the time of welding, the presence of the dispersed particles can suppress the crystal grains from being coarsened, and can suppress the embrittlement of the heat-affected zone.

By using such a copper alloy as the material of the heat transfer tube 8, the present invention allows the transfer of the antifreeze liquid even when the circulation speed of the antifreeze liquid is increased, particularly in the pressure-resistant containers 2 and 6 on the low temperature side. Erosion of the inner wall surface of the heat tube 8 can be suppressed, and a decrease in the strength of the heat transfer tube 8 due to the erosion can be prevented. Further, since the inner surface of the heat transfer tube 8 is less likely to be corroded, it is possible to form a fin having a fine convex structure that is susceptible to erosion on the inner surface of the heat transfer tube 8, thereby improving the heat exchange efficiency by the fin. .

Further, in the pressure-resistant containers 1 and 4 using water as the refrigerant, erosion similar to that in the case of antifreeze may occur if the circulation rate of water is increased. However, in this embodiment, all the heat transfer tubes are used. Erosion in the pressure-resistant containers 1 and 4 can also be prevented because 8 is made of the copper alloy.

Although a general precipitation hardening type copper alloy has characteristics of good heat conductivity, extremely high strength, and excellent corrosion resistance, it is difficult to form a thin plate material that is poor in workability and can be subjected to ERW. Difficult to manufacture. In addition, in general precipitation hardening type copper alloys, crystal coarsening is apt to occur in the welded portion during ERW, and the mechanical properties of the welded portion are greatly deteriorated compared to the base metal. And the reliability of the welded portion is low.

The present inventors have found that, by using a precipitation hardening type alloy and changing the precipitation hardening conditions from the conventional one, a heat transfer tube having good workability and high reliability of the welded portion can be manufactured. The present invention has been completed.

The specific precipitation hardening treatment in the present invention comprises the following steps. Cr, Zr, Ti, Mg, Ni, Fe, Co, Si,
A copper alloy containing 10 wt% or less of one or more elements selected from Al, Sn, P, and Zn is
A step of performing hot rolling by heating to 950 ° C., more preferably 860 to 930 ° C. The hot-rolled copper alloy is cold-rolled at a working ratio of 70% or more, more preferably 75 to 80%, and 500 to 750.
Forming a sheet material by repeating annealing at a temperature of 600C, more preferably 600 to 700C, a plurality of times. 450-700 ° C, more preferably 60-70 ° C,
When heated to 0 to 650 ° C, the Vickers hardness is 9 (Hv).
Step of tempering so as to be 0 or less, more preferably 60 to 80. A step of forming a heat transfer tube by subjecting the plate material to electric resistance welding.

By performing the above treatments, an appropriate precipitate is generated in the copper alloy, and the thermal conductivity, strength and corrosion resistance of the copper alloy can be increased. In addition, according to the above-mentioned heat treatment, since a precipitate is generated in an overaged state, the strength of the copper alloy shows a slightly lower value than general precipitation hardening treatment conditions. However, by making the precipitation overaged in this way, the workability of the copper alloy is improved, and the present invention facilitates the indispensable electric resistance welding and forms fins on the inner surface of the heat transfer tube 8. Also becomes possible. In addition, since the difference in physical properties between the base metal portion and the welded portion after the electric resistance welding is reduced,
There is no fear that stress concentrates on the welded portion and the welded portion is broken, and the heat transfer tube 8 can be manufactured.

It should be noted that 45% of the heat-transformed heat transfer tube is
A step of performing an annealing treatment at 0 to 700 ° C. for 1 to 120 minutes may be further provided. By providing this annealing treatment step, the material after fin processing can be made uniform, and the effect of improving workability such as bending workability can be obtained. More preferable annealing treatment conditions are 550 to 650 ° C. for 10 to 150 minutes.

When fins are formed on the inner surface of the heat transfer tube 8, a step of rolling the fins on the tempered plate material is provided, and the fin rolled surface is turned inside. What is necessary is just to perform the said electric resistance sewing. By rolling the fins on the inner surface of the heat transfer tube 8, an effect of stirring the antifreeze or water flowing in the heat transfer tube 8 is obtained, and a boundary layer is prevented from being generated in the flow of the antifreeze or water. Alternatively, heat exchange between water and the heat transfer tube 8 is promoted, and the heat exchange efficiency can be increased.

FIGS. 4 and 5 show examples in which fins 50 are rolled on the inner surface of the heat transfer tube 8. FIG. 4 shows an example in which the fins 50 are formed in a simple spiral shape. A groove 52 is formed between the fins 50. A pair of finless portions 54 are formed on the side edges of the strip-shaped plate material serving as the material of the heat transfer tubes 8, and the heat transfer tubes 8 are obtained by welding these finless portions 54. 58 is a welded portion formed by welding the finless portion 54,
Usually, a projection is formed over the entire length toward the inner surface of the tube.

The shape and the like of the fin 50 are not limited in the present invention, but the angle (lead angle) of the fin 50 with respect to the tube axis direction is 30 to 90 °, and the bottom width of the fin 50 is 0.1 to 5 m.
m, the pitch of the fins 50 in the tube axis direction is 0.5 to 5
mm. More preferably, fin 5
0 to the tube axis direction (lead angle) is 60 to 90
゜, the bottom width of the fin 50 is 1 to 3 mm, and the pitch of the fin 50 in the tube axis direction is 1 to 3 mm. Within such a range, the formation of a boundary layer in the flow of antifreeze or water flowing in the heat transfer tube 8 is effectively prevented, and the pressure loss is small.

On the other hand, in the embodiment shown in FIG. 5, the fins 50 have a “W” shape extending in a zigzag manner in the circumferential direction of the inner peripheral surface of the heat transfer tube 8. Instead of the “W” shape, a “V” shape that refracts twice may be used, or “VV” that refracts six times.
It may have a “V” shape. Also, cuts may be made in the bent portions of the fins so that some of the antifreeze or water passes through these cuts to further reduce the pressure loss.

The fin 50 as described above is provided on the inner surface of the heat transfer tube 8.
Is formed, the generation of a boundary layer in the flow of antifreeze or water can be suppressed, and a decrease in heat exchange efficiency due to the generation of the boundary layer can be prevented.

Note that the present invention is not limited to the above-described embodiment, and various modifications may be made as necessary.
For example, since the heat transfer tubes 8 in the pressure-resistant containers 1 and 4 do not come into contact with the antifreeze, they may be configured by ordinary heat transfer tubes. Further, another hot water generator may be used in place of the boiler 18, another liquid cooling device may be used in place of the cooling towers 20 and 22, and another container may be used instead of the freezer 24. A cooling device may be used.

Further, the heat transfer tube of the present invention is not only used for a refrigeration system using a hydrogen storage alloy as described above, but can be applied to a general heat exchange system using a highly corrosive refrigerant. It is possible.

[0046]

As described above, according to the heat transfer tube with inner grooves according to the present invention, even when the circulation speed of the antifreeze is increased, the erosion of the inner wall surface of the heat transfer tube by the antifreeze is suppressed, and the transfer by the erosion is suppressed. A decrease in the strength of the heat tube can be prevented.

Further, since the inner surface of the heat transfer tube is less likely to be corroded, it is possible to form a fin having a fine convex structure that is susceptible to erosion on the inner surface of the heat transfer tube, thereby improving the heat exchange efficiency by the fin. I can do it.

Further, according to the refrigeration system of the present invention, the erosion of the heat transfer tube can be reduced, so that the service life of the system can be prolonged, and the circulation speed of the antifreeze is increased as compared with the conventional one, so that a high cooling capacity is obtained. Obtainable.

[Brief description of the drawings]

FIG. 1 is a block diagram showing an embodiment of a refrigeration apparatus according to the present invention.

FIG. 2 is a cross-sectional view of the pressure container according to the embodiment.

FIG. 3 is an enlarged cross-sectional view showing a fixed state of the radiation fin and the heat transfer tube in the embodiment.

FIG. 4 is a partially developed plan view showing an example of a heat transfer tube used in the embodiment.

FIG. 5 is a partially developed plan view showing an example of a heat transfer tube used in the embodiment.

[Explanation of symbols]

 1, 2, 4, 6 Pressure vessel 8 Heat transfer tube 10 Radiation fin 12 Hydrogen storage alloy powder 14, 16 Hydrogen gas passage 26 to 40 Valve 18 Boiler 20, 22 Cooling tower 24 Freezer 50 Fin

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) C22C 9/04 C22C 9/04 9/06 9/06 9/10 9/10 C22F 1/08 C22F 1 / 08 A HJK F25B 17/12 F25B 17/12 Z F28F 1/40 F28F 1/40 D 21/08 21/08 E // C22F 1/00 604 C22F 1/00 604 626 626 630 630 630A 650 650F 651 651A 682 682 683 683 685 685Z 686 686B 691 691B 691C 694 694A (72) Inventor ▲ Sukumo ▼ Shun Tadashi ▲ Green ▼ 128-7 Ogimachi, Aizuwakamatsu-shi, Fukushima Prefecture Mitsubishi Shindoh Wakamatsu Works F-term (reference) 3L093 NN PP07 PP12 QQ07 RR03

Claims (7)

[Claims] An antifreeze liquid heat transfer tube used in contact with an antifreeze liquid, comprising Cr, Zr, Ti, Mg, Ni,
It is formed of a copper alloy containing 0.01 to 10 wt% of one or more elements selected from Fe, Co, Si, Al, Sn, P, and Zn, and the average grain size of the copper alloy is 3 to 30 μm, thermal conductivity 0.5-0.9 cal / cm
A heat transfer tube for antifreeze, wherein the temperature is sec ° C and the yield strength is 10 kg / mm ² or more. 2. The copper alloy is a precipitation hardening alloy in which precipitates are dispersed, and the precipitates have an average particle size of 0.01 to 0.01.
The heat transfer tube for an antifreeze according to claim 1, wherein the heat transfer tube has a thickness of 0.3 µm. 3. The heat transfer tube for antifreeze according to claim 1, wherein fins are rolled on an inner surface of the heat transfer tube. 4. A pressure vessel, a heat transfer tube disposed inside the pressure vessel, a hydrogen storage alloy filled in the pressure vessel in a heat exchangeable state with the heat transfer tube, An antifreeze circulating mechanism that circulates antifreeze into the heat pipe, wherein the heat transfer pipe includes Cr, Zr, Ti,
Mg, Ni, Fe, Co, Si, Al, Sn, P, Zn
One or two or more elements selected from
It is formed of a copper alloy containing 10 wt%, the copper alloy has an average crystal grain size of 5 to 30 μm or less, and a thermal conductivity of 0.
A refrigeration system characterized by a temperature of 5 to 0.9 cal / cmsec ° C and a proof stress of 10 kg / mm ² or more. 5. Cr, Zr, Ti, Mg, Ni, Fe,
Hot rolling is performed by heating a copper alloy containing 0.1 to 10% by weight or less of one or more elements selected from Co, Si, Al, Sn, P, and Zn to 750 to 950 ° C. A step of forming a strip material on the hot-rolled copper alloy by repeating cold rolling at a working ratio of 70% or more and annealing at 500 to 750 ° C. a plurality of times; Production of a heat transfer tube comprising: a step of heating to about 700 ° C. and tempering so that the Vickers hardness (Hv) becomes 90 or less; and a step of forming a heat transfer tube by subjecting the plate material to electric welding. Method. 6. The heat-transferred heat transfer tube is 450-450.
The method for manufacturing a heat transfer tube according to claim 5, further comprising a step of performing an annealing treatment at 700 ° C for 1 to 120 minutes. 7. The method according to claim 1, further comprising the step of rolling fins on the tempered sheet material, wherein the electric resistance welding is performed with the fin-rolled surface inside. Item 7. The method for manufacturing a heat transfer tube according to item 5 or 6.