WO2001013057A1

WO2001013057A1 - Heat exchange tube and heat recovery method using it

Info

Publication number: WO2001013057A1
Application number: PCT/JP2000/005205
Authority: WO
Inventors: Takashi Noto; Hiroaki Nishio
Original assignee: Nkk Corporation
Priority date: 1999-08-12
Filing date: 2000-08-03
Publication date: 2001-02-22
Also published as: EP1122506A1; TW546454B; KR20010072966A

Abstract

A heat exchange tube consisting of a sintered body having a porosity of 2-60%, and a heat exchange tube having a surface layer consisting of a composite material of ceramics and metal; specifically, when a heat-resistant alloy tube is used as a base and a surface layer is formed of a composite material of ceramics and metal, such structures are preferable; that the outer surface of the heat-resistant alloy tube is non-bondingly covered with a composite material of ceramics and metal, with the heat-resistant alloy tube contacting the composite material at at least part of their boundary; or that the outer surface of the heat-resistant alloy tube is sequentially covered non-bondingly with a thermal expansion buffer material and a composite material of ceramics and metal, with the alloy tube contacting the thermal expansion buffer material and/or the thermal expansion buffer material contacting the composite material at at least part of their boundaries. The heat exchange tube ensures a stable heat recovery over an extended time even in a high-temperature, corrosive environment such as combustion exhaust gas of industrial wastes.

Description

Description Heat tube and heat recovery method using the same Technical field The present invention relates to a heat exchange tube for recovering heat from high-temperature exhaust gas generated when incinerating municipal solid waste or the like, through water vapor, air, or the like. It relates to the heat recovery method using it. Background Discussion Currently, municipal solid waste, coal, sewage, «sludge, and other industries» The heat generated by burning 400-1200 exhaust gas generated from the combustion of materials such as steam, air, etc. As a result, the heat recovery system that recovers heat and uses it for power generation etc. has been enhanced.

However, the exhaust gas generated when the fuel and cities GoMiyasan, higher temperature corrosive become stronger salt I NaCl, KC1, Na ₂ SO Dian because it contains that, Suminori boiler Heat exchange tubes made of meta-alloys such as stainless steel and Ni-Co alloy cannot be used at high temperatures, and the temperature of the fluid to be heated flowing through the heat exchange tubes will be below 300 ° C Is controlled as follows. For this reason, dogs do not have sufficient heat recovery.

Therefore, in order to recover higher-temperature heat without causing corrosion, Japanese Patent Application Laid-Open No. 5-332508 discloses a ceramic heat source, and Japanese Patent Application Laid-Open No. 10-274401 discloses the following method. There is a heat tube in which the outer surface of a heat tube made of such a metal alloy is covered with ceramics.

However, when exposed to elevation for a long time, they adhere and accumulate on the ceramic surface. The rate difference between the deposited layer of fly ash containing fertilized salt and the ceramics The cracks and exfoliation occur in the ceramics due to the difference in thermal conductivity between the metal alloy and the ceramics, and stable heat recovery over a long period of time is not possible. In addition, the thickening of the bottle may cause a decrease in the amount of Xinyuan, which may lead to a decrease in heat rate of 3%. DISCLOSURE OF THE INVENTION An object of the present invention is to provide a heat tube capable of performing stable heat recovery for a long time even at a height, and a heat recovery method using the same. This purpose is achieved by a heat tube made of a sintered body with a porosity of 2-60% or a heat tube made of a composite forest material with ceramics.

Especially, を part is made of ceramics ^! When formed with a composite forest material, the outer surface of the base metal tube is covered with a composite forest material of ceramics and metal. In the material, the outer surface of a heat tube or a metal alloy tube at least at the interface at its interface is covered with a composite of the material, ceramics and metal in a sequential manner. The meta-combustion alloy tube and the heat material and the heat or the heat-exposure material and the composite material make the heat tube, which is at least "^" at the interface, stable for a longer time. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a screen view of a heat tube according to the present invention.

FIG. 2 is a longitudinal sectional view of a heat exchange tube which is another example of the present invention.

FIG. 3 is a cross-sectional view of a heat tube according to another example of the present invention.

FIG. 4 is a simplified view of a heat tube according to another example of the present invention.

FIG. 5 is a cross-sectional view of the heat tube of FIG.

FIG. 6 is a cross-sectional view of a heat tube of another example of the present invention. FIG. 7 is a cross-sectional view of a heat tube as another example of the present invention.

FIG. 8 is a longitudinal sectional view of a heat exchange tube as another example of the present invention.

FIG. 9 is a cross-sectional view of the heat exchange tube of FIG.

FIG. 10 is a cross-sectional view of a heat tube according to another example of the present invention.

FIG. 11 is a cross-sectional view of a heat tube of another example of the present invention. BEST MODE FOR CARRYING OUT THE INVENTION We studied heat exchange tubes that can be used for a long time under high-temperature rot from the viewpoints of preventing fly ash accumulation and cracking of ceramics itself. As a result, to prevent fly ash from escaping, if a heat exchange tube consisting of a sintered body of metal-ceramic with a porosity of 2-60% is used, the heated fluid flowing through the heat exchange tube Part of the gas can be ejected from the pores, preventing the accumulation of other particles including ^ Sffi ^. At this time, the porosity is set to 2 to 60%. When the porosity is set to 2% or more, there is no need to manufacture under a special high-temperature and high-pressure condition, and S¾g cost is reduced. Then git to make the tube itself cool. Also, as a method of ejecting “" ”of the heat fluid from the pores, it is advisable to set the pressure of the heat fluid in the heat-building tube higher than the pressure of the atmosphere outside the heat exchange tube. If the heat tube made of this sintered body is made of a composite forest material of ceramics and metal, the ceramics will have excellent corrosion resistance, and the metal will also improve the brittleness of the ceramics itself, and will have excellent corrosion resistance and cracking. Difficult heat 3 ^ tube. On the other hand, for the prevention of cracking of the ceramic itself, the surface layer may be a heat tube formed of a ceramic / metal composite forest material for the reasons described above.

The ceramic in the composite forest charges described _{_{above, i0 2, Zr0 2, Cr}} 2 O 3, A1 2 0 3, Si0 2, Y 2 0 3, Ce0 2, oxides such as Sc s, BN, MgB ₂ Ca¾ , Ί¾Β ₂ , ZrB ₂ , AlB j: Which boride, B ₄ C, iC, ZrC, carbides such as _{_{_{Cr 3 C 2, A1 4 C}}} 3, SiC, A1N, TiN ZrN, Cr 2 N, Si 3 N 4 of which nitrides, such as AION or Si ₂ N ₂ 0 Or a mixture thereof.

In addition, any metal can be used as the metal in the composite material, but Al, Al-Si alloy, Al-Mg alloy, etc., which are excellent in terms of receptivity and cost effective, should be used. Good. In particular, A1 contained in the composite pillow is excellent in reciting as ceramics, 14 and is more preferable than A1N force, which is hard to adhere to. 1¾ ^ ± is also convenient because it is only necessary to醒理the A1 in an N ₂ atmosphere. However, in order to suppress the occurrence of corrosion and cracks under high temperature decay, A1N should be 1-90 wt. /. And (A1 + A1) must be 50 wt% or more. If A1ON of ceramics is further added to this composite forest material consisting of A1 and A1N, it will become more difficult to adhere the covertly. However, in this case, A1N is 1-90 wt. /. And make the power (A1 + A1N + A10N) more than 50 wt% '. Here, the A10N, Al, O, the total term for solid liquid _{_{N, A1 U 0 16 N,}} Α10Ν, ΑΙ ^ Ο ^, A ^ 0 39 N, Α1 10 Ο 3 Ν 8, A, 0 3 _{_{N SiAl 7 0, N 7 SiaAl}} 3 represent like 0 ₄₅ N _5.

In such ceramics and metal composite pillow charges the surface of, BN, compound or SiC containing B (boric萄such B ₄ C, by coating or dipping a compound containing a C (charcoal ^) such as black ^, such as 1- With a thickness of 400 m, adhesion of the compound can be substantially prevented, and if the compound is applied or immersed regularly, the heat tube can be stabilized for a longer time.

For the heat exchange tube, the surface layer may be formed of such a composite material, and the inside may be formed of a conventional heat-resistant alloy tube, for example. Force to 12 mm is better. If the base is made of a metal alloy tube and the details are made of such a composite forest material, the outer surface of the metal tube can be covered with a composite material of ceramics and metal in a non-enclosed state. At least the heat of the forest material in the direction of the pipe Ifc ^ The strain due to the difference in the long rate can be overcome and the cracking and peeling of the composite material can be more reliably prevented. Also, this meta-twisted alloy tube and this composite forest material, If the interface is made at least as HTiri-fibre-structured, heat recovery can be performed with high heat without a significant decrease in tranquility.

In this case, the ceramic-metal composite material contains 1-90 wt% of A1N and 50% or more of (A1 + A1N + A10N), and has a porosity of 2-60% for the reasons described above. ^ T that power is good.

When the compound containing B or c as described above is applied to the outer surface of the metal alloy tube, the sliding force between the metal alloy and the composite pillow will be smooth, and the difference in heat length ratio between the tubes will be smooth. The distortion due to is almost completely reduced. When a metal alloy tube is used as the base and a part of the metal tube is made of such a composite material, the outer surface of the metal alloy tube is covered with a heat material and a composite material of ceramics and metal. The structure of the composite pillow may be at least at the interface between the slif material and the heat-expandable material and the composite pillow. In this case, the distortion due to the difference in the heat in the pipe diameter direction due to the difference of the Peng's tension ratio is also caused by the 爱 bend material.

In this case, as the heat material, it is possible to use fiber ridges mainly composed of B, C or A1, powder, film or tape.

For the above reasons, the composite material contains 1-90 wt% of A1N and 50 wt% or more of (A1 + A1N + A10N) and has a porosity of 2-60%. . Also, compounds containing B or C are likely to be ^ ffiT on the outer surface of the stranded metal tube. In any of the above-mentioned heat tubes, considering the sintering and cracking of the composite material and the heat of the tube itself, such as the bow iSt, etc., the length is less than 6 mm and the outer diameter is 20-200 mm. It is preferred that The cross-sectional shape may be circular or square, and there is no particular PI. Example 1

It is composed of a ceramic-metal composite material 1 having the cross-sectional shape and microstructure shown in Fig. 1. Single-layer heat 3 熱 tube No. 1 and the surface shape shown in Fig. 2, the first layer is an S-twisted metal tube 2, the second layer is carbon fiber 隹 3, and the third layer is a surface layer The three-layered heat tube No. 2 whose part is a composite material 1 of ceramics and metal, and the heat exchange tube No. 3 with BN coating on the outer surface of the heat tube No. 2 were installed in a municipal solid waste incineration pilot plant. Heat recovery was performed according to the high-temperature exhaust gas of 750-950 ° C.

Details of heat exchange tubes No. 1 and 2 are as follows.

Heat tube No. 1

Composite material of ceramics and metal: A1 + A1N + A10N 90 wt% or more, thickness 4 mm, outer diameter: 40 mm

Heat exchange tube No. 2

Metal alloy tube: SUS304, thickness 4 rmn, carbon fiber 繊: thickness 4 mm, composite material of ceramic and metal: A1 + A1N + A10N 90 wt% i¾ ±, thickness 10 mm, outer diameter: 40 mm

In addition, the waste gas from the Tokyo Togomi TO pilot plant! ^ Is, 2-16% (vol, dry, following the same of 0 _2, 100-500 ppm of HC1, max 300 ppm of SOx, 5-18% of C0 _2, balance N ₂ der ivy. Heat exchanger in the tube As the ¾¾D thermal fluid, a water vapor at the inlet of 150-400 ° C and a mixed gas of air and 120-300 ° C and a combustion gas were used.

As a result, it was recognized that in all cases of heat 3¾ tubes, the amount of reduction in thickness due to corrosion was slight and cracks did not occur. In particular, in Hot Tube No. 3 with BN coating on the outer surface, the reduction in thickness due to corrosion was as small as 30% or less of that in Mature Exchange Tubes Nos. 1 and 2. Unprecedented 2

The single-layer heat exchange tubes Nos. 4 and 5 made of a composite material 1 of ceramics and metal having a surface shape and having pores 4 shown in FIG. In the high-temperature exhaust gas of 750-950 ° C, the pressure of the hot fluid was increased above the pressure of the exhaust gas atmosphere as in Example 1 and the hot fluid "^" was ejected from the pores. The details of heat tubes Nos. 4 and 5 are as follows. Heat tube No. 4

Composite fee of ceramic and ^] man: A1 + A1N 90 wt /. Above, thickness 4 mm, porosity 20%, outer diameter: 40 mm

Heat tube No. 5

Composite material with ceramics: A1 + A1N 90 wt% or more, thickness 6 mm, porosity 60%, outer diameter: 40 mm

As a result, in any of the heat tubes, 含む containing water does not accumulate on the surface. 水蒸気 The steam with the inlet of 150-400 ° C was used as the heat fluid until the outlet ^ reached 500 ° C. If the inlet ^^ is 120-300 ° C and the mixed gas of 1000-5000 mmAq of air and 100-400 mmAq of leak gas is used, it can be heated until the outlet SJ is about 800, Heat recovery with high heat.

In the case of heat exchange tube No. 5 with a porosity of 60%, when the pressure of the fluid to be heated is set to 5000 mm Aq or more, the outer surface of the heat tube becomes 100 ° C or more lower than Si in the exhaust gas atmosphere. The pressure of the fluid to be heated should be 4000 mmAq. Example 3

The dog has a longitudinal section shown in FIG. 4 and a cross section shown in FIG. 5, and the outer surface of the meta-combustion alloy tube 2 is covered with a ceramic and metal composite pillow 1 in a non-coated state, and The metal alloy tube 2 is in contact with the composite material dough 1 at least at its interface, so the heat tube No. 6-9 with a gap 5 is replaced by the same municipal waste pipe as in male example 1. The heat was recovered from the plant plant's high-temperature exhaust gas at 650-950 ° C.

Details of heat exchange tube No. 6-9 are as follows.

Heat exchange tube No. 6

Metal alloy tube: SUS304-15A, composite material of ceramics and metal: A1 + A1N + A10N 90 wt% or more, thickness 5-10 mm, porosity 40%

Heat tube No. 7

Metal alloy tube: SUS304-20A, composite material of ceramics and metal: A1 + A1N + A10N 9 0 wt. /. Above, thickness 6-8 mm, porosity 20%

Heat tube No. 8

Biaxial alloy tube: SUS304 "20A, outer surface BN coating, composite forest material of ceramics and metal: A1 + A1N + A1ON 90 wt% or more, thickness 6-8 mm, porosity 20%

Heat 3¾ tube No. 9

而撤Alloy Tube: SUS304-20A, composite of ceramic and ^ S _{_{梂料: A1 2 0 3 80 \ ^}} % or more on the + AL thickness 2-4 mm, porosity of 30%

Further, components of To巿waste '腳pilot plan Bok of exhaust gas, 2-16% of 0 _2, HC1 of 200-600 pp m, max 300 ppm of SOx, 4 · 19% of C0 _2, with the balance N ₂ there were.

As a result, for any of the heat tubes, the amount of reduction in thickness due to corrosion is small, and no cracks are generated. It was recognized that it was capable. In particular, in heat tube No. 8 in which the outer surface of the metal alloy tube was coated with BN, no change was observed in the cross-sectional shape after the fiber, and the sliding force between the BN coat and the ceramic-metal composite material was reduced.力 6.

In addition, if the inlet £! Uses steam at 300-400 ° C as the heat fluid, the outlet can obtain 500 以上 C or more ata ata force, and the inlet heat can be 120-300 ° C. It was confirmed that when using a mixed gas of air of 1000-5000 mmAq and waste gas of 100-400 mmAq, it was possible to heat up to 800 ° C at the outlet. Difficult case 4

With the surface shape shown in Fig. 4 and the cross-sectional shape shown in Fig. 5, the outer surface of the meta-alloy tube 2 is inactively covered with the composite forest material 1 of ceramics and metal, and the meta-alloy tube is 2 and composite pillow 1 force At least at ^^ at the interface, so heat tubes Nos. 10 and 11 with air gap 5 can be removed using the same municipal waste pilot plant as in Example 1. In the ¾¾ exhaust gas atmosphere at 700-1000 ° C, which was converted into gas, heat was applied.

Details of heat tubes No. 10 and 11 are as follows. Heat exchange tube No. 10

而燃Alloy Tube: boiler而携collars STBA28-20A, ceramic and metal composite materials: A 1 + A1N 90 wt% > Al 2 O 3 7wt%, thickness 6-7 mm, porosity 25%

Heat; ^ tube No. 11

Meta-combustion alloy tube: For boiler! ^ ff STBA28-20A, composite material of ceramics and metal: SiC 95 wt% or more + Mg, thickness 6-7 mm, porosity 2%

As a result, since the high-temperature exhaust gas was a commercial gas atmosphere with 5 to 15% CO, there was almost no phenomenon of deterioration due to sic or flattened wrinkles, and it was possible to perform good heat recovery. . Example 5

The outer surface of the metamorphic alloy tube 2 of the same shape or U-shaped tube shape shown in Fig. 6 and Fig. 7 is non-bell-covered with the composite forest material 1 of ceramics and metal. 2 and 1 composite material, at least at the interface of which is marked with "^", and therefore heat tube No. 12-14 with void 5 was placed in the coal, sewage cake, and the combustion gas of the furnace. Installed and heat recovered.

Details of heat exchange tube No. 12-14 are as follows.

Atsushi male tube No. 12

Meta-combustion alloy tube: Heat-resistant tube for boiler STBA28-40A and 65A, composite material of ceramics and metal: SiC 95 wt% or more + Mg, thickness about 7 mm, same shape (Fig. 6)

Heat exchange tube No. 13

而燃Alloy Tube:而燃tube STBA28-20A and 50A boiler, ceramic and metal composite materials: A1 ₂ 0 ₃ 95 wt. /. + AL thickness about 3 mm, coaxial tube shape (Fig. 6)

Heat tube No. 14

Meta-combustion alloy tube: For boiler! ^ STBA28-15A and 20A, composite material of ceramic and metal: A1 + A1N 90 wt% or more, thickness 6-10 mm, U-tube shape (Fig. 7)

As a result, coal and sewage mud burnt gas contains several hundred ppm of SOx power; These heat exchange tubes were not corroded, and were capable of recovering high-temperature high-efficiency 7K steam, achieving high power generation efficiency of 30% or more, and recovering high-temperature air and fine gas.

When a U-shaped control dog is used as shown in Fig. 7, it is necessary to allow more voids 5 to exist at the bend. Example 6

With the vertical cross-sectional shape shown in Fig. 8 and the horizontal cross-sectional shape shown in Fig. 9, the outer surface of the meta-twisted alloy tube 2 is successively covered in a non-crane state with a composite material of 露 ^ R I and ceramic and ^. The metal alloy tube 2 and the ^ 6 material 6 and the Z or material 6 and the composite material 1 are at least partially in contact with each other at their interfaces, and therefore, the heat exchange tube No. 15 -18 was installed in high-temperature exhaust gas at 650-950 ° C in the same municipal solid waste pipe plant as in Example 1, and heat was recovered.

Details of heat 3¾ tube No. 15-18 are as follows.

Heat exchange tube No. 15

Bi-twist alloy tube: SUS304-15A, heat return material: A1 foil, thickness 1-2 mm, composite material of ceramics and metal: A1 + A1 + A10N 90 wt ° /. Above, thickness 4-10 mm, porosity 40% heat exchange tube No. 16

Bi-twisted alloy tube: SUS304> 20A, mmm: carbon fiber 隹, thickness O.2-2 mm, composite forest material of ceramics and metal: A1 + A1N + A10N 90 wt ⁰ /. Above, thickness 3-8 mm, porosity 20% Heat exchange tube No. 17

Metallic twisted alloy tube: SUS304-20A, outer surface BN coating, heat] Peng Yongjia material: carbon fiber 隹, thickness 0.2-2 mm, composite forest material of ceramics and metal: A1 + A1N + A10N 90 wt% or more , Thickness 3-8 mm, porosity 20%

Heat exchange tube No. 18

Metal alloy tube: SUS30 20A, heat I Coating material: carbon H 锥, thickness 1-2 mm, composite material of ceramics and metal: Αίβ ₃ 80 wt% or more + Α1, thickness 2-4 mm, porosity 30 %

In addition, the composition of flue gas from the Municipal Garin Pilot Plant is 2-16% 0. , 200-600 pp m of HC1, max 300 ppm of SOx, 4-19% of CO _2, and the balance N _2.

As a result, it was confirmed that the thickness of each of the heat exchange tubes was slightly reduced due to corrosion, no cracks were generated, and stable heat exchange was possible over a long period of time. In particular, in heat exchange tube No. 17 in which the outer surface of the metal alloy tube was coated with BN, no change was observed in the cross section of the dog after 1200 hours. It was recognized that the slip was smooth.

In addition, the age of using steam with the inlet ^ t of 280-400 ° C as the heat fluid is more than 540 at the outlet, and lOO ata can be obtained. In the case of using a mixed gas of 1000-4000 mmAq of air and 50-400 mmAq of ^^ fuel J¾ ^ gas, it was confirmed that heating up to 800 ° C was possible at the outlet. Example 7

With the vertical cross-sectional shape shown in Fig. 8 and the horizontal cross-sectional shape shown in Fig. 9, the outer surface of the metal alloy tube 2 is mm mm, and the ceramics and metal pipes are joined together by Nadarin Lin. , And the metal tube 2 and the heat <1> material 6 and heat or heat> The H 爱 impact material 6 and the composite forest material 1 are at least partially in contact at the interface, and thus the heat exchange tube Bu Nos. 19 and 20 were heated in a 700-1000 ° C exhaust gas atmosphere where municipal solid waste was partially oxidized by the same municipal solid waste pilot plant as in Example 1, and heat was recovered.

Details of heat tubes No. 19 and 20 are as follows.

Heat exchange tube No. 19

Meta-combustion alloy tube: Boiler meta-combustion tube STBA28-20A, heat Awakening material: carbon 80% or more fine pine, thickness 0.5-3 mm, composite material of ceramics and metal: A1 + A1N 86 wt%, A1, 0 ₃ 6wt%, thickness 4-5mm, porosity 25%

Heat exchange tube No. 20

Kyo alloy tube: Boiler tubing STBA28-20A, heat] Peng Yong-sheng material: carbon 80 wt. /. Fine fiber of above, thickness 1-3 mm, composite material of ceramics and metal: SiC 95 wt% or more and Mg, thickness 4-5 mm, porosity 2% As a result, since the high-temperature exhaust gas was in an S¾ gas atmosphere with a CO separation of 5 to 15%, there was almost no experience of deterioration due to the application of SiC or A1N, and good heat recovery was possible. . Male example 8

10 and the Development ^ ³ 11幵娥outer surface of而撤alloy tube 2 of that shown in FIG. 11 is covered with the BS ^ Takaya爱衝material 6 and the ceramic and sequentially unbonded忧態by composite material 1 of the metal In addition, the heat tubing that passes through the gap 5 is at least at the interface between the alloy tube 2 and the heat, and the X Xiao lumber 6 and Z or Wei Zhuo lumber 6 and the composite forestry 1 at the interface. Bu No. 21-23 was installed in coal, sewage water cake, and the combustion gas of the ^^^ TO furnace, and heat was recovered.

Heat 33 ^ Tube No. 21-23 The following is the paste.

Heat exchange tube No. 21

Meta-combustion alloy tube: Boiler meta-combustion tube STBA28-40A and 65A, heat] Awakening material: Mixture of fine powder and fiber of 80 wt% or more carbon, thickness 0.2-4 mm, Composite material of ceramics and metal: SiC 95 wt % + Mg, thickness about 7 mm, same as above (Fig. 10)

Heat tube No. 22

而撚Alloy Tube:而擻tube STBA28-20A and 50A boilers, heat "彭弓material: carbon 80 wt% or more fines, the thickness 0.3-2 mm, ceramic and metal composites: Α1 ₂ Ο ₃ 95 wt% Above + A1, about 4 mm thick (Fig. 10)

Heat tube No. 23

Twisted alloy tube: Boiler for STBA28-15A and 20A, Heng Peng Yong-sheng material: carbon fiber 80wt% or more fine pine, thickness 0.4-1mm, ceramic and metal composite material: A1 + A1 90wt% or more , Thickness 6-8 mm, U Ψ ^ Τί (Fig. 11)

As a result, coal and sewage-burning fuel gas contain hundreds of ppm of SOx power, but none of the heat exchange tubes are corroded, and the high-temperature high temperature exceeding 30% is generated. Recovery of steam and recovery of hot air and column gas were the functions of the [^]. In the case of a U-shaped tube shape as shown in FIG. 11, the force ¾ ^ is to allow more voids 5 to be present in the bent portion.

Claims

Claims 1. A heat 33 tube made of a sintered body having a porosity of 2-60%.

2. The heat tube according to claim 1, wherein the sintered body is a composite material with ceramics.

3. Using the heat exchange tube of claim 1, the pressure of the fluid to be heated flowing through the heat exchange tube is determined by the pressure of the atmosphere outside the heat tube.

4. A method for recovering heat, comprising the step of using the heat tube of claim 2 to raise the pressure of the heat fluid in the knitting heat tube higher than the pressure of the atmosphere outside the IS heat exchange tube.

5. Thermal tube made of composite material of ceramic and metal.

6. The composite material is l-90wt% A1N, 50wt. /. The heat exchange tube according to claim 5, comprising (A1 + A1N).

7. The composite material is 1-90 wt ° /. The thermowing wing tube according to claim 5, comprising 50 wt% or more of (A1N) and (A1 + A1N + A10).

8. The tube according to claim 5, wherein the surface of the composite material has a compound containing B (borax or C (charcoal).

9. The ISH 5 heat ^^ tube as claimed in which the composite material has a 3-12 mm.

10. External surface force of the metal alloy tube The metal tube is unsealed by a composite material of ceramics and metal, and the self-twisted alloy tube and the metal composite material are at least partially formed at the interface.熱 heat tube.

11. The composite material is l-90 wt% A1N, 50 wt. /. Claim 10 including the above (A1 + A1N + A10N) Heat Wei tube.

12. B or on the outer surface of the twisted alloy tube. Compounds containing a ffl 10 heat 3d ^ tuf are claimed.

13. The heat exchange tube of claim 10, wherein the composite material has a porosity of 2-60%.

14. The outer surface force of the fuel alloy tube is covered with mS ^ SI material and a composite forest material of ceramics and metal. Bubble dew impact material and Z or discomfort heat ”Awakening material and till self-composite forest material is a heat 3¾ tube characterized by at least ^^ at the interface.

15. The heat tube according to claim 14, wherein the composite material contains l-90 wt% of A1N and 50 wt% or more of (A1 + A1N + A10N).

16. The heat exchange tube according to claim 14, wherein the material of Pengya is a material mainly composed of B, C or A1, such as fine powder, powder, film or tape.

17. The heat tube of claim 114, wherein a compound containing B or C is provided on the outer surface of the tube.

18. The heat exchange tube of claim 14, wherein the composite material has a porosity of 2-60%.