JP2001349679A - High temperature plate fin heat exchanger - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a plate fin heat exchanger with excellent mass production wherein there can be realized performance required for a regenerating plate fin heat exchanger in a micro-gas turbine power generating apparatus, i.e., high heat exchange efficiency and high durability under violent variations of a thermal load. SOLUTION: Although in a plate fin heat exchanger all fins in a high temperature side passage are usually brazed to a low temperature side passage, provided all the fins are independently brazed for each low temperature side passage without brazing all the fins in the high temperature side passage, there can be moderated thermal stress due to uneven temperature distribution in a fluid passage and the entire of the fluid passage upon high temperature combustion gas flowing in. Further, the fins located in the high temperature side passage are reduced in their sizes and fixedly mounted on the side of the low temperature side passage, and small spacer bars are disposed at positions where no fin is provided to manufacture core assembling elements. Then, assembling of these elements are very facilitated by subjecting the spacers to sealing welding for example and lamination.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to improvement of a high-temperature plate fin type heat exchanger for exchanging heat between combustion exhaust gas and air, for example, and fins are provided on both tube plate surfaces of a low-temperature air passage. Attached elements are stacked and arranged via a spacer bar, and the cylindrical high-temperature fluid duct itself can be used as a heat exchanger vessel.For example, severe use conditions such as a regenerator of a micro gas turbine power generator However, the present invention relates to a high-temperature plate fin type heat exchanger exhibiting excellent durability and high heat exchange efficiency.

[0002]

2. Description of the Related Art At present, a micro gas turbine power generator has been reviewed and put to practical use as an emergency private power generator or a small- to medium-scale distributed power supply. Gas turbines are characterized in that they can be mass-produced with a simpler configuration than other internal combustion engines, are easy to maintain and inspect, and have low NOx.

[0003] In order to improve the total power generation efficiency, the next-generation micro gas turbine power generator generally employs a single-shaft regeneration cycle gas turbine.

[0004] That is, a compressor, a turbine, and a generator are arranged on a single shaft, and the combustion gas from the combustor rotates the turbine, and then exchanges heat with the air passing through the compressor in a heat exchanger, thereby obtaining combustion gas energy. The heat conversion efficiency is at least as high as that of a conventional diesel-powered generator.

[0005]

SUMMARY OF THE INVENTION In the configuration of a single-shaft regenerative cycle gas turbine, low NOx is realized by lean combustion, and the heat exchange efficiency is increased to about 90% by using a plate fin type heat exchanger. Has been done.

[0006] On the other hand, the micro gas turbine power generator is used not only for emergency use but also for use as a distributed power source, so that not only repeated start and stop operations are performed frequently, but also a good start-up immediately after start-up is performed and high-quality power is immediately supplied. Is required.

[0007] Therefore, the plate fin type heat exchanger used for heat exchange between the combustion gas and the compressed air achieves excellent heat exchange efficiency, and has a rapid heat input, especially an uneven temperature distribution in the fluid passage. Therefore, it is required to maintain the above heat exchange efficiency while maintaining the durability enough to withstand a severe fluctuation of the heat load.

[0008] The present invention can achieve the above-mentioned performance required for a plate fin heat exchanger for regeneration in a micro gas turbine power generation device, that is, high heat exchange efficiency and high durability under a severe fluctuation of heat load, and mass production. An object of the present invention is to provide a plate-fin type heat exchanger having a configuration excellent in performance.

[0009]

SUMMARY OF THE INVENTION In the plate fin type heat exchanger, for example, the present inventors have relieved thermal stress due to uneven temperature distribution in the fluid passage and when the high-temperature combustion gas flows, for example. As a result of various studies on possible configurations, usually all the fins in the high-temperature side passage are brazed to the low-temperature side passage, but as shown in FIG. It has been found that by making each side passage independent, the thermal stress is relieved, the durability is remarkably improved, and the component can be made into an element, and the brazing process is reduced, thereby improving the mass productivity.

[0010] Further, as a result of various studies on the configuration that is easy to manufacture, the inventors have found that the fins in the high-temperature side passage are reduced and fixed to the low-temperature side passage, and a small spacer bar is arranged in a place where no fin is provided. The present inventor has found that it is extremely easy to assemble a core assembling element by stacking the elements by, for example, seal welding the spacer bars to each other, thereby completing the present invention.

That is, the present invention uses a core assembling element in which a fin forming a high-temperature fluid passage and a spacer bar are fixed to at least one of a pair of tube plates forming a low-temperature fluid passage. A high-temperature plate-fin heat exchanger characterized in that a low-temperature fluid passage and a high-temperature fluid passage are laminated and arranged independently for each passage to form a core.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A configuration example of a high-temperature plate-fin heat exchanger according to the present invention will be described with reference to the drawings. Figure
The example shown in FIG. 1 shows a case where the high-temperature fluid and the low-temperature fluid exchange heat in countercurrent. As shown in FIG.1B, the high-temperature fluid H passes through the core 2 of the heat exchanger 1 from the front to the back of the figure, and the low-temperature fluid L flows in from the rear side of the heat exchanger 1 and the front side. It is a configuration that flows out more.

The core 2 of the heat exchanger 1 has a hot fluid passage 4
And the low-temperature fluid passages 5 are alternately stacked. As shown in FIG. 1A and FIG. 2, the low-temperature fluid passage 5 has a corrugation fin 5b between two tube plates 5a, 5a.
, And these members are brazed and integrated so that the outer peripheral portion is closed by the spacer bar 5c.

The spacer bar 5d on one end face is shortened to form the fluid inlet 6 and the outlet 7, and triangular fins are arranged at the fluid distributors 5e and 5f to form a distribution passage.

Further, on the outer surfaces of the two tube plates 5a, 5a of the low-temperature fluid passage 5, corrugation fins 4a,
4b is brazed. Here, the corrugation fins 4a, 4b are arranged at positions facing the fin main part 5g, excluding the distributor parts 5e, 5f in the low-temperature fluid passage 5, and mainly at the ends of the relative positions with the distributor parts 5e, 5f. Short spacer bars 4b are fixed to four places respectively.

[0016] A spacer which uses the element for assembling the core mainly composed of the low-temperature fluid passage 5 having the above-described structure and in which the low-temperature fluid passage 5 abuts up and down in a container 3 containing the core 2 of the heat exchanger 1 The high-temperature fluid passages 4 can be arranged at predetermined intervals by the bar 4b, and the high-temperature fluid passages 4 are formed by the corrugation fins 4a and 4b provided in the low-temperature fluid passages 5 and 5 located above and below. Here, the spacer bars 4b on the right side of the figure are seal-welded to each other, and the spacer bars 4b on the left side of the figure are not fixed.

The fluid inlet 6 and the outlet 7 of the low-temperature fluid passage 5 are fixed only to the right side of the box-shaped container 3 in the drawing and cantilevered, and the spacer bar 4b on the left side of the drawing is fixed. Further, the low-temperature fluid passages 5 are arranged in the container 3 at intervals such that the corrugation fins 4a and 4b do not come into contact with each other. A header tank (not shown) is fixedly disposed at the fluid inlet 6 and the outlet 7 of the container 3.

In the high-temperature plate-fin heat exchanger according to the present invention having the above configuration, for example, when the high-temperature fluid H suddenly flows, the inlet side of the high-temperature fluid passage 4 of the container 3 is rapidly heated. . Here, the high-temperature fluid passage 4 is provided with a corrugation fin 4 provided at the center of the outer surface of the low-temperature fluid passage 5.
a, 4b, which are not constrained in the high-temperature fluid passage 4 and efficiently conduct heat of the high-temperature fluid H into the low-temperature fluid passage 5 without accumulating thermal stress even when heated rapidly. it can.

Further, in the low-temperature fluid passage 5, the low-temperature fluid L flowing from the distributor 5e exchanges heat with the high-temperature fluid H in a counter-current without flowing, and is heated to a higher temperature than the fluid outlet 7 through the distributor 5f. Can be spilled. At this time, as described above, the corrugation fins 4a and 4b of the high-temperature fluid passage 4 are not at the relative positions of the distributors 5e and 5f, and the thermal stress is reduced even when exposed to a high temperature.
No accumulation of thermal stress occurs in the low-temperature fluid passage 5 itself due to the cantilever-supported structure.

The low-temperature fluid passage 5 desired at the inlet of the high-temperature fluid passage 4
By providing shielding covers of various configurations on the front surface, it is possible to alleviate the sudden heat input when the high-temperature fluid H suddenly flows. For example, it is possible to adopt a means such as providing a louver member which also functions as a rectifier, providing a heat insulating member, or extending and bending the tube plate of the low-temperature fluid passage 5.

In the present invention, various means other than the above-mentioned structure can be adopted as means for making each low-temperature fluid passage independent, a structure in which corrugation fins are provided only on one side of the low-temperature fluid passage, a structure for cross-flow heat exchange, A configuration in which the fluid duct itself is used as a container of the heat exchanger can be adopted.

[0022] In the present invention, in the method of laminating the low-temperature fluid passages and the high-temperature fluid passages in the core, the passages are alternately arranged, and various arrangements can be adopted by a combination of countercurrent, crossflow, and the like. It can be appropriately selected according to the fluid type, temperature, and the like.

In the present invention, the material of the heat exchanger is not particularly limited, but when heat resistance is considered, a known Fe-based, Ni-based,
Co-based heat-resistant alloys can be used, for example, austenitic heat-resistant steel, Co ₃ Ti, Ni ₃ Al, etc., and stainless steel containing 10 wt% or less of Al can be appropriately used.

[0024]

Embodiment 1 As a regenerator of a micro gas turbine power generator, FIG.
A high-temperature plate-fin heat exchanger having the configuration shown in FIG. 2 was employed. By setting and configuring the dimensions so that the container inlet of the heat exchanger is directly fitted into the flue gas duct, a flange or the like is not required and the pressure loss of the flue gas can be minimized.

[0025] Two kinds of combustion exhaust gas temperatures, 800 ° C and 900 ° C, were set, and heat exchange was performed between the two and compressed air (0.4 MPa). In each case, a heat exchange efficiency of 90% was obtained. Was completed. As the material of the heat exchanger, austenitic stainless steel was used when the exhaust gas temperature was 800 ° C, and 5 wt% Al-containing stainless steel was used when the exhaust gas temperature was 900 ° C.

[0026] Further, the apparatus cooled to room temperature was started, and after a predetermined time, the apparatus was cooled to the predetermined temperature and restarted, and a durability acceleration test was performed. None of the exchange efficiencies fluctuated, and no peeling or cracking occurred in any part of the heat exchanger.

[0027]

The plate fin type heat exchanger for high temperature according to the present invention employs an independent structure for each of the low temperature fluid passages. Thermal stress can be relaxed by uniform temperature distribution, and high heat exchange efficiency and high durability under severe heat load fluctuation required for plate fin heat exchanger for regeneration in micro gas turbine power generation equipment can be realized.
In addition, as shown in the embodiment, the unit can be formed into a unit, the number of brazing steps can be reduced, and the configuration is excellent in mass productivity.

Further, since the configuration of the heat exchanger of the present invention is independent for each low-temperature fluid passage, for example, in addition to compressed air in the above configuration example, when water is introduced, water vapor is obtained. It is possible. Further, in the above configuration example, since each low-temperature fluid passage is independent and is cantilevered on the side surface of the container, when a problem occurs in any of the low-temperature fluid passages, it is easily closed, or Replacement is possible, which is advantageous for maintenance.

In particular, in the configuration of the embodiment, the assembling unit mainly composed of the low-temperature fluid passage has a rectangular plate as a basic shape and does not have any forming processing. There is an advantage that the assembly can be performed by joining only a few places by brazing or welding.

[Brief description of the drawings]

FIG. 1A is a perspective explanatory view showing an example of a core of a high-temperature plate fin type heat exchanger according to the present invention, and FIG. 1B is a perspective explanatory view showing an example of a high-temperature plate fin type heat exchanger.

2A is a cross-sectional view of the center of the assembling unit mainly including the low-temperature fluid passage, FIG. 2B is an explanatory view of the inside of the assembling unit when the low-temperature fluid passage is viewed, and FIG. It is.

[Explanation of symbols]

 1 Heat exchanger 2 Core 3 Container 4 High temperature fluid passage 4a Corrugation fin 4b, 5b, 5c, 5d Spacer 5 Low temperature fluid passage 5a, 5a Tube plate 5e, 5f Distributor part 5g Fin main part 6 Fluid inlet 7 Outlet H High temperature fluid L Low temperature fluid

Continuing from the front page (72) Inventor Takashi Eda 1-10 Fuso-cho, Amagasaki-shi, Hyogo F-term in Sumitomo Precision Industries, Ltd. (Reference) 3L103 AA09 AA37 BB17 CC22 CC27 DD54 DD92

Claims (4)

[Claims] 1. A low-temperature fluid passage independent by using a core assembly element in which a fin and a spacer bar forming a high-temperature fluid passage are fixed to at least one of a pair of tube plates forming a low-temperature fluid passage. A high-temperature plate-fin heat exchanger having a configuration in which a low-temperature fluid passage and a high-temperature fluid passage are stacked and arranged to form a core. 2. The high-temperature fluid according to claim 1, wherein the tubular high-temperature fluid duct itself is used as a heat exchanger vessel, and a low-temperature fluid inlet / outlet is provided on a side surface of the duct to form a countercurrent core. Plate fin type heat exchanger. 3. The fin of the high-temperature fluid passage is disposed only at a position facing the main fin portion except for the distributor portion in the low-temperature fluid passage, and the spacer bar is disposed at least at a position where the fin is not disposed. The plate fin type heat exchanger for high temperature described in 1. 4. The high-temperature plate fin according to claim 2, wherein a plurality of units in which a plurality of assembling elements are stacked and fixed at a spacer bar portion by brazing or welding are divided and incorporated so as to form a core. Type heat exchanger.