JP2016075420A - Heat exchanger - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a heat exchanger in which heat is exchanged between an inner tube and an outer tube and in which entire area in the inner tube is filled with gas, resulting in improvement of the heat exchange efficiency of the heat exchanger.SOLUTION: A heat exchanger 10 comprises an outer tube 11 of rectangular parallelepiped shape and a cylindrical-shaped inner tube 12 formed inside the outer tube 11. The inner tube 12 forms an exhaust gas flow passage 12F in it. The exhaust gas flow passage 12F is formed to connect an exhaust gas inlet 13 with an exhaust gas outlet 14. The outer tube 11 forms an air flow passage 11F between an outer circumferential surface of the inner tube 12 and an inner circumferential surface of the outer tube 11. A resisting member 17 is arranged inside the inner tube 12. The resisting member 17 is an exhaust gas flow passage 12F and provided between the exhaust gas inlet 13 and the exhaust gas outlet 14. The resisting member 17 acts as a partition plate which has a plurality of through-holes and closes the exhaust gas flow passage 12F. The resisting member 17 provides throttling to the exhaust gas flow passage 12F to increase an inner pressure in the exhaust gas flow passage 12F.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a heat exchanger used in a fuel cell device.

  In a heat exchanger used in a fuel cell device, in order to improve the heat exchange efficiency between the exhaust gas and the oxidant gas as the heat receiving fluid, the heat exchanger has a double pipe structure, and an exhaust gas passage pipe is formed in the inner pipe. In addition, a technique has been proposed in which an air flow path serving as a heat receiving fluid is formed in the outer pipe and heat exchange between exhaust gas and air is performed.

  For example, in the heat exchanger of Patent Document 1, an exhaust gas passage pipe having an exhaust gas introduction passage and an exhaust gas discharge passage is accommodated in a case, and a plurality of exhaust pipes are formed in parallel from the exhaust gas introduction side to the exhaust side. ing. The power generation air flow path is formed between the case and the exhaust gas flow pipe, and the oxidant gas flowing in the case flows meandering around the outer periphery of the plurality of exhaust gas flow pipes while being guided by the guide plate. Thus, heat exchange between the inflowing air and the exhaust gas is performed.

JP 2012-14921 A

  By the way, an air flow path is formed between the case of the heat exchanger and the exhaust gas flow path pipe, or conversely, an exhaust gas flow path is formed between the case of the heat exchanger and the air flow path pipe. In such a case, as in the heat exchanger of Patent Document 1, air or gas does not flow into the corners of the case and the like, but the air or gas is distributed over the entire outer periphery of the exhaust gas channel pipe or air channel tube. I couldn't. Therefore, the heat exchange efficiency between exhaust gas and air was low. In particular, when the exhaust gas or air inlet or outlet is formed other than the end of the case, the upstream side of the inlet or the downstream side of the outlet is not filled with gas or air. Efficiency was even lower.

  The present invention has been made in view of such a problem, and an object of the present invention is to provide a heat exchanger that performs heat exchange between the inner tube and the outer tube, and distributes gas over the entire area of the inner tube. A heat exchanger with improved exchange efficiency is provided.

  In order to solve the above problems, a heat exchanger according to the present invention is formed between an inner tube forming a first gas flow path and an outer periphery of the inner tube, and between the outer peripheral surface of the inner tube. An outer pipe that forms a gas flow path, and the inner pipe includes a gas inlet through which a gas flows, a gas outlet through which the gas is discharged, the gas inlet, and the gas outlet. A resistor for restricting the first gas flow path to be connected, and the resistor is formed between the gas inlet and the gas outlet.

  According to the above aspect, the internal pressure of the first gas flow path is increased by providing the resistor in the first gas flow path of the inner tube and providing the throttle to the first gas flow path by the resistance body. Can do. As a result, the gas can be spread over the entire first gas flow path, and the heat exchange efficiency between the inner tube and the outer tube can be increased.

  Preferably, the resistor is a partition plate in which a plurality of through holes are formed, and is formed on the inner pipe so as to close the first gas flow path. In this aspect, it is possible to dispose the resistor in the first gas flow path with a simple configuration in which the partition plate having a plurality of through holes is formed in the inner tube.

  Further, preferably, the inner pipe has irregularities on the wall surface so as to increase the surface area of the first gas flow path. In this aspect, the inner tube and the outer tube are increased by increasing the surface area of the first gas flow channel in the inner tube while increasing the internal pressure of the first gas flow channel by the resistor and spreading the gas into the flow channel. The heat exchange efficiency with can be further increased.

  Preferably, the unevenness is formed in a spiral shape on the wall surface of the inner tube. In this aspect, by forming the irregularities in a spiral shape, not only can the surface area of the first gas channel be increased, but also the internal pressure of the first gas channel can be increased in addition to the resistor. be able to. Therefore, the gas can be spread all over the first gas flow path, and the heat exchange efficiency between the inner tube and the outer tube can be further enhanced.

  ADVANTAGE OF THE INVENTION According to this invention, in the heat exchanger which performs heat exchange between an inner tube | pipe and an outer tube | pipe, the heat exchanger which improved heat exchange efficiency can be provided by spreading gas over the whole region of an inner tube | pipe.

The block diagram which shows the whole structure of the fuel cell apparatus incorporating the heat exchanger of this invention. The cross-sectional schematic diagram which shows the whole structure of the heat exchanger of this invention. AA sectional drawing of FIG. The cross-sectional schematic diagram which shows other embodiment of the heat exchanger of this invention.

  Hereinafter, embodiments of the present invention (hereinafter referred to as the present embodiment) will be described with reference to the accompanying drawings. In order to facilitate the understanding of the description, the same constituent elements in the drawings will be denoted by the same reference numerals as much as possible, and redundant description will be omitted.

  With reference to FIG. 1, the whole structure of the fuel cell apparatus 100 in which the heat exchanger 10 of this embodiment was integrated is shown. As shown in FIG. 1, the fuel cell device 100 has the same configuration as that of a conventional fuel cell device, and the heat exchanger 10, the fuel reformer 20, the fuel cell stack 30, and the inverter 40 of the present embodiment. And a control device 50.

  The fuel reformer 20 is means for taking out hydrogen from the gas by reacting the gas with water vapor. The fuel cell stack 30 is a means for generating electricity by reacting oxidant gas (power generation air) CG with hydrogen supplied from the fuel reformer 20. The inverter 40 is means for converting direct current electricity generated in the fuel cell stack 30 into alternating current electricity. The control device 50 is means for controlling the entire fuel cell device 100.

  The heat exchanger 10 in the present embodiment is means for heating the oxidant gas CG introduced from the outside by the heat of the exhaust gas EG generated by combustion in the fuel cell stack 30.

  Then, with reference to FIG.2 and FIG.3, the structure of the heat exchanger 10 is demonstrated. 2 is a cross-sectional plan view showing the overall configuration of the heat exchanger 10, and FIG. 3 is a cross-sectional view taken along the line AA in FIG.

  As shown in FIGS. 2 and 3, the heat exchanger 10 includes a rectangular parallelepiped outer tube 11 and a cylindrical inner tube 12 formed inside the outer tube 11. In other words, the outer tube 11 is formed on the outer periphery of the inner tube 12. In the present embodiment, the outer tube 11 also serves as the case of the heat exchanger 10, but the present invention is not limited to such an embodiment, and the case and the outer tube 11 may be configured separately.

  As shown in FIG. 2, the inner pipe 12 forms an exhaust gas passage (first gas passage) 12 </ b> F inside. The exhaust gas flow path 12 </ b> F is formed so as to connect the exhaust gas inlet 13 and the exhaust gas outlet 14. That is, the exhaust gas EG discharged from the fuel reformer 20 shown in FIG. 1 flows from the exhaust gas inlet 13, passes through the exhaust gas passage 12 </ b> F in the inner pipe 12, and is discharged to the outside from the exhaust gas outlet 14. Is done.

  The exhaust gas inlet 13 and the exhaust gas outlet 14 are formed of a cylindrical pipe and are attached to the wall surfaces of the outer tube 11 and the inner tube 12. The inner pipe 12 is supported and fixed to the outer pipe 11 by the exhaust gas inlet 13 and the exhaust gas outlet 14.

  The outer tube 11 forms an air flow path (second gas flow path) 11 </ b> F between the outer peripheral surface of the inner tube 12 and the inner peripheral surface of the outer tube 11. That is, the air flow path 11 </ b> F is formed over the entire outer peripheral surface of the cylindrical inner tube 12. The air flow path 11 </ b> F is formed so as to connect the air inlet 15 and the air outlet 16. That is, the oxidant gas CG which is a heat receiving fluid is supplied from the outside, flows in from the air inlet 15 and is heated while passing through the air flow path 11F, and then, from the air outlet 16 as described in FIG. The fuel cell stack 30 is supplied.

  The air inlet 15 and the air outlet 16 are formed of a cylindrical pipe and are attached to the wall surface of the outer tube 11 in the same manner as the exhaust gas inlet 13 and the exhaust gas outlet 14. Although the attachment position of the air inlet 15 and the air outlet 16 with respect to the outer tube 11 is arbitrary, it is preferable to attach to both ends in the longitudinal direction as shown in FIG. 2 in consideration of the flow of the air flow path 11F.

  As shown in FIG. 2, a resistor 17 is provided inside the inner tube 12. The resistor 17 is an exhaust gas flow path 12 </ b> F and is provided between the exhaust gas inlet 13 and the exhaust gas outlet 14. The resistor 17 is for partitioning the exhaust gas passage 12F and increasing the internal pressure in the exhaust gas passage 12F, and is a partition plate that blocks the exhaust gas passage 12F.

  The detailed structure of the resistor 17 is also shown with reference to FIG. As shown in FIGS. 2 and 3, the resistor 17 has a circular shape as a whole and has a tray shape including a flat plate portion 17 </ b> A and a mounting portion 17 </ b> B. That is, the mounting portion 17B is formed to rise in the vertical direction on the outer periphery of the flat plate portion 17A with respect to the disc-shaped flat plate portion 17A.

  A plurality of through holes 17C are formed in the flat plate portion 17A. The through-hole 17C is a portion that forms the exhaust gas passage 12F and that restricts the exhaust gas passage 12F. The attachment portion 17B is an attachment allowance for fixing to the inner peripheral surface of the inner tube 12 by welding or the like. When the resistor 17 is formed integrally with the inner tube 12 or when the end of the flat plate portion 17A is attached as it is, the attaching portion 17B can be omitted.

  According to the heat exchanger 10 described above, the resistor 17 is provided in the exhaust gas passage 12F of the inner pipe 12, and the exhaust gas passage 12F is throttled by the resistor 17 to increase the internal pressure of the exhaust gas passage 12F. Can do. As a result, the exhaust gas EG can be spread over the entire exhaust gas flow path 12F. Therefore, the heat of the exhaust gas EG flowing through the inner pipe 12 can be conducted to the oxidant gas CG flowing through the outer pipe 11 over the entire inner pipe 12, and the heat exchange efficiency of the heat exchanger 10 can be increased. .

  In particular, as shown in the example of FIG. 2, in the case where the exhaust gas inlet 13 is formed near the center of the exhaust gas flow channel 12F instead of the end of the inner pipe 12, the upstream side of the exhaust gas flow channel 12F. The corners on the side are difficult to fill with exhaust gas. In this respect, according to the heat exchanger 10, since the internal pressure of the inner pipe 12 can be increased by the resistor 17, the exhaust gas can be filled in the corner on the upstream side of the exhaust gas passage 12F. Therefore, the heat exchange efficiency of the heat exchanger 10 can be kept high regardless of the position where the exhaust gas inlet 13 and the exhaust gas outlet 14 are provided.

  Further, the resistor 17 can be freely arranged in the exhaust gas flow path 12F by a simple configuration in which a partition plate in which a plurality of through holes 17C are formed is attached to the inner pipe 12.

  Then, with reference to FIG. 4, 10 A of heat exchangers which become the other aspect of the heat exchanger 10 are demonstrated. In addition, the same code | symbol is attached | subjected about the structure similar to the heat exchanger 10, and description is abbreviate | omitted. 4 does not show the resistor 17 for convenience of explanation, it is assumed that the resistor 17 is also formed in the heat exchanger 10A as shown in FIG.

  As shown in FIG. 4, the heat exchanger 10 </ b> A is obtained by improving the configuration of the wall surface of the inner tube 12 </ b> A. The inner pipe 12A includes irregularities 12A1 on the wall surface so as to increase the surface area of the exhaust gas passage 12F. The unevenness 12A1 is formed in a spiral shape on the wall surface of the inner tube 12A.

  In the above heat exchanger 10A, the internal pressure of the exhaust gas passage 12F in the inner pipe 12 is increased by increasing the internal pressure of the exhaust gas passage 12F by the resistor 17 and spreading the exhaust gas into the exhaust gas passage 12F. The heat exchange efficiency between the pipe 12A and the outer pipe 11 can be further increased.

  Further, by forming the irregularities 12A1 in a spiral shape, not only can the surface area of the exhaust gas passage 12F be increased, but also the exhaust gas can flow smoothly in the exhaust gas passage 12F. Therefore, the exhaust gas EG can be spread over the entire exhaust gas flow path 12F, and the heat exchange efficiency between the inner pipe 12A and the outer pipe 11 can be further enhanced by flowing the exhaust gas smoothly.

  The embodiments of the present invention have been described above with reference to specific examples. However, the present invention is not limited to these specific examples. In other words, those specific examples that have been appropriately modified by those skilled in the art are also included in the scope of the present invention as long as they have the characteristics of the present invention.

  In the present embodiment, the resistor 17 is configured by a plate-like body in which a plurality of through holes 17C are formed. However, the resistor in the present invention is not limited to such an embodiment, and the internal pressure of the exhaust gas passage 12F is In order to increase, it can be widely included as long as it becomes a resistance of the exhaust gas flow. For example, an orifice plate that protrudes toward the center of the inner pipe 12 and that restricts the exhaust gas flow path 12F can be installed inside the inner pipe 12. Further, by crushing the inner pipe 12 in a circumferential shape, the inner pipe 12 can be protruded toward the gas flow path side of the inner pipe 12 and configured as a throttle of the exhaust gas flow path 12F. Further, the resistors are not necessarily provided on the inner circumference of the inner tube 12, and can be formed by being divided in the longitudinal direction of the inner tube 12. It is also possible to form by placing.

  In this embodiment, the air flow path 11F is formed in the outer tube 11, and the exhaust gas flow channel 12F is formed in the inner tube 12. However, in the present invention, this is reversed and the exhaust gas flow channel is formed in the outer tube 11. And an air flow path may be formed in the inner tube 12. Further, the overall shape of the outer tube 11 and the inner tube 12 is not limited to a square tube or a circular tube, and can be arbitrarily configured according to the design.

  In addition, the elements included in each of the specific examples described above and their arrangement, materials, conditions, shapes, sizes, and the like are not limited to those illustrated, but can be changed as appropriate. Moreover, each element with which each embodiment mentioned above is provided can be combined as long as technically possible, and the combination of these is also included in the scope of the present invention as long as it includes the features of the present invention.

10, 10A: Heat exchanger 11: Outer tube 11F: Air channel 12, 12A: Inner tube 12A1: Concavity and convexity 12F: Exhaust gas channel 13: Exhaust gas inlet 14: Exhaust gas outlet 15: Air inlet 16: Air outlet 17: resistor 17A: flat plate portion 17B: mounting portion 17C: through hole 20: fuel reformer 30: fuel cell stack 40: inverter 50: control device 100: fuel cell device CG: oxidant gas EG: exhaust gas

Claims (4)

An inner pipe that forms a first gas flow path, and an outer pipe that is formed on the outer periphery of the inner pipe and that forms a second gas flow path between the outer peripheral surface of the inner pipe,
The inner pipe includes a gas inlet for allowing gas to flow in, a gas outlet for discharging gas, and a resistor for restricting the first gas flow path connecting the gas inlet and the gas outlet. ,
The resistor is a heat exchanger formed between the gas inlet and the gas outlet.   2. The heat exchanger according to claim 1, wherein the resistor is a partition plate in which a plurality of through holes are formed, and is formed in the inner pipe so as to close the first gas flow path.   3. The heat exchanger according to claim 1, wherein the inner pipe is provided with unevenness on a wall surface so as to increase a surface area of the first gas flow path.   The heat exchanger according to claim 3, wherein the unevenness is formed in a spiral shape on the wall surface of the inner tube.

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