JP2007068297A - Gas power generation equipment and fuel cell system combined with gas power generation equipment - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide gas power generation equipment and a fuel cell system combined with gas power generation equipment wherein when the thermal energy of gas is converted into electrical energy, the efficiency of thermoelectric conversion is further enhanced. <P>SOLUTION: The gas power generation equipment is provided with a passage partitioning portion 29 including: a gas passage 23 that lets high-temperature gas through the central part in its body barrel 21; and a thermoelectric conversion module housing section 31. The thermoelectric conversion module housing section is defined by a cooling medium passage wall 32 outside the gas passage 23, and houses a thermoelectric conversion module 1 constructed of a p-type semiconductor chip 2 and an n-type semiconductor chip 3. The gas power generation equipment is further provided with a cooling medium passage 28a that adjoins the passage partitioning portion 29 and lets a cooling medium through so that the cooling medium intersects the flow of the high-temperature gas and meanders. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a gas power generator that further improves thermoelectric conversion efficiency when converting thermal energy of a high-temperature gas into electric energy, and a fuel cell system combined with the gas power generator.

Recently, human energy consumption has been accelerated to an unprecedented level, and global warming due to greenhouse gases such as CO ₂ has been highlighted as a serious social problem, and CO ₂ generation is suppressed as much as possible. Measures are required from all over the world.

  Under such demands, research and development of effective use of waste heat is being promoted from the viewpoint of energy saving, and among them, the use of medium to small-scale waste heat is attracting attention.

  Medium and small-scale waste heat use has a relatively low heat quantity even if the heat quality is good. For example, in a large-scale waste heat use power plant such as a steam turbine, a large amount of heat is required to increase the heat quantity. There is a problem that the power generation efficiency is lowered and the amount of electricity corresponding to the cost of modification, maintenance and repair of the existing equipment cannot be obtained.

  In addition, due to its low calorific value, it is often sent off for hot water use and the like, and the use of small and medium-sized waste heat worldwide tends to be difficult to actively use over a wide range of fields.

  Under such circumstances, there has been a demand for the realization of a thermoelectric conversion device that can easily convert electric energy from the heat energy into small-scale waste heat with a small facility even with small-scale waste heat.

  Based on such a request, recently, as seen in Patent Document 1 and Non-Patent Document 1, development of a thermoelectric conversion device that directly converts thermal energy of a high-temperature fluid into electrical energy using a semiconductor element has advanced. It has been.

  When the high-temperature fluid is a gas, for example, as disclosed in Patent Document 2, thermal energy is converted into electric energy between a high-temperature gas flow path (high-temperature side) through which a high-temperature gas flows and a cooling medium flow path (low-temperature side). It has been proposed that a semiconductor element to be converted into a module is modularized, and the modularized semiconductor element is arranged between a high temperature side and a low temperature side to generate power.

  In the gas power generation system having such a configuration, in order to improve the thermoelectric conversion efficiency, it is necessary to increase the temperature on the high temperature side and to take a large temperature difference between the high temperature side and the low temperature side.

  In addition to improving the thermal conductivity of each flow path member on the high temperature side and the low temperature side, the contact heat resistance on the high temperature side and the low temperature side of the modularized semiconductor element is small, and each other with an appropriate surface pressure. Contact was required.

Although such problems have been studied through trial and error, they still have no prospect of a solution, and are currently searching for them.
JP 2004-1119833 A JP 11-36981 A “Thermoelectric Conversion Engineering-Fundamentals and Applications-” Realize, Inc. 349-363 (2001)

  In the case of a gas power generation device, for example, in the case of a solid oxide fuel cell, the temperature of the gas power generation device rises to about 800 to 1000 ° C. Therefore, thermal expansion in the longitudinal direction (axial direction), width direction, and thickness direction depends on the temperature. Becomes larger.

  On the other hand, on the low temperature side, the temperature is still around the outside temperature recently and thermal expansion is small.

  Thus, when the temperature difference becomes remarkably large, distortion and deviation occur between the high temperature side and the low temperature side of the modularized semiconductor element, and the semiconductor element may be damaged.

  In addition, if the temperature difference is large, the surface contact force between the high temperature side and the low temperature side is reduced due to thermal expansion, the semiconductor element has a large contact thermal resistance, and the thermal conductivity is deteriorated, and the thermoelectric conversion efficiency is remarkably increased. There was a decline. In particular, since the material of the modularized semiconductor element used in the gas power generation apparatus is brittle and has low rigidity, it has problems such as a decrease in thermal conductivity due to deformation and damage to the material itself.

  The present invention has been made based on such circumstances, and is combined with a gas power generation apparatus and a gas power generation apparatus that further improve the thermoelectric conversion efficiency when converting the thermal energy of gas into electric energy. An object is to provide a fuel cell system.

  In order to achieve the above-mentioned object, the gas power generator according to the present invention is defined by a gas passage for allowing a high-temperature gas to flow through a central portion in the body trunk, and a cooling medium passage wall outside the gas passage. Providing a passage partition portion including a thermoelectric conversion module housing portion for housing a thermoelectric conversion module composed of a p-type semiconductor chip and an n-type semiconductor chip, and adjacent to the passage partition portion, for the flow of the high-temperature gas In addition, a cooling medium passage is provided which passes through the cooling medium while meandering.

  In order to achieve the above object, a fuel cell system combined with a gas power generation device according to the present invention combines a fuel cell with at least two gas power generation devices, and the gas power generation device from the fuel cell. Any of means for supplying exhaust gas as a high-temperature gas, and fuel gas, air, a mixed gas of hydrogen and air, a mixed gas of fuel gas and air, and a mixed gas of carbon monoxide and air as a cooling medium to the gas power generator And a means for selecting and supplying these.

  The gas power generation device according to the present invention is provided with a passage partition portion that meanders while intersecting the cooling medium with respect to the flow of the high-temperature gas, and a gas passage wall and a cooling medium passage wall are provided outside both sides of the passage partition portion, Since the thermoelectric conversion module is accommodated in each wall and its rigidity and surface contactability are increased, the stability of the thermoelectric conversion module is maintained, and the thermal conductivity and thermoelectric conversion efficiency are further improved and improved. be able to.

  Further, the fuel cell system combined with the gas power generation device according to the present invention supplies the exhaust gas from the fuel cell main body as a high-temperature gas to the thermoelectric conversion module of the gas power generation device, so that the energy can be reused. The effective thermoelectric conversion efficiency of the gas power generator can be further improved.

  Hereinafter, embodiments of a gas power generation apparatus and a fuel cell system combined with the gas power generation apparatus according to the present invention will be described with reference to the drawings and reference numerals attached to the drawings.

  FIG. 1 is a conceptual diagram illustrating the principle of one of the thermoelectric conversion modules incorporated in the gas power generation apparatus according to the present invention.

  In the thermoelectric conversion module 1, the p-type semiconductor chip 2 and the n-type semiconductor chip 3 are sandwiched between a high-temperature side insulating plate 7 having a high-temperature side electrode 5 and a low-temperature side insulating plate 8 having a low-temperature side electrode 6. The thermoelectric conversion element 4 is comprised and many thermoelectric conversion elements 4 are provided electrically and thermally.

  The p-type semiconductor chip 2 and the n-type semiconductor chip 3 are connected to the high-temperature side electrode 5 by the high-temperature side semiconductor chip connection portion 11, and the p-type semiconductor chip 2 and the n-type semiconductor chip 3 are connected to the low-temperature side electrode 6. The connection is made at the low temperature side semiconductor chip connecting portion 12.

  In the thermoelectric conversion module 1 having such a configuration, when the heat flow 13 is applied to the high temperature side electrode 5, the heat is supplied to each of the p-type semiconductor chip 2 and the n-type semiconductor chip 3 via the high temperature side semiconductor chip connecting portion 11. To be told.

  Furthermore, when the heat passes through the semiconductor chips 2 and 3, the heat flows along the heat flow 14, and the holes 16 and the electrons 17 that are semiconductor carriers in the respective interiors are connected to the low temperature side via the chip connection portion 12. It moves toward the low temperature side electrode 6.

  Further, the heat flow 14 passing through each of the semiconductor chips 2 and 3 passes through the low temperature side electrode 6 and becomes a heat flow 15 released from here to the outside.

  On the other hand, an electric load unit 19 is provided outside the thermoelectric conversion module 1 via an electrode current coupling unit 9 and a current extraction unit 10 provided in the thermoelectric conversion element 4, and the movement of each of the semiconductor carriers described above is a current. The flow 18 is taken out by the electric load unit 19 and supplied to the outside as electric power.

  As described above, the thermoelectric conversion module 1 utilizes the ability of the thermoelectric conversion element 4 to skillfully utilize the temperature difference between the high temperature side and the low temperature side to directly supply electricity to the outside. ing.

  In this way, the gas power generation apparatus 20 incorporating the thermoelectric conversion module 1 that converts thermal energy into electrical energy includes a box-shaped main body cylinder 21 and an axial direction at the center of the main body cylinder 21 as shown in FIG. After the gas passage 23 through which the high temperature gas 22 flows along the (longitudinal direction), the cooling medium supply passage 25 for supplying the cooling medium 24 to the main body cylinder 21, and the thermoelectric conversion with the high temperature gas 22 in the main body cylinder 21 And a cooling medium discharge path 26 for discharging the cooling medium 24 to the outside.

  Further, as shown in FIG. 3, the main body 21 of the gas power generation apparatus 20 has a cooling medium supplied from the cooling medium supply path 25 while the hot gas 22 flows along the axial direction in the center of the inside. A cooling medium passage 28a is formed in which the one end is the cooling medium passage opening 27 and the other end is formed in the cooling medium bag passage 18 from the bottom side to the head side so as to meander while flowing. , 28a,... And the cooling medium passages 28a, 28a,... Are provided with partition portions 29, 29,..., And the thermoelectric conversion module 1 is accommodated in the passage partition portions 29, 29,. Yes.

  FIG. 4 is a diagram showing a positional relationship among the thermoelectric conversion module 1, the cooling medium passage opening 27, the cooling medium bag passage portion 28, and the like in the main body cylinder 21 of the gas power generation apparatus 20, and the gas power generation apparatus 20 includes the main body cylinder. The cooling power generation passage opening 27 and the cooling medium passage portion 28 are disposed on both sides of the passage 21, and passage partition portions 29, 29,... For housing and forming the thermoelectric conversion module 1 and the gas flow passage 23 are provided at intermediate positions.

  Then, a broken line area A is extracted, and the positional relationship between the cooling medium passages 28a, 28a,... And the passage partition portions 29, 29,. .. Are provided adjacent to each of the cooling medium passages 28a, 28a,..., And the central portion of the passage partition portions 29, 29,... Is divided by gas passage walls 30, 30,. And a thermoelectric conversion module housing part 31 for housing the thermoelectric conversion module 1 on the outside of the thermoelectric conversion module housing part 31, and a thermoelectric conversion at the end of the thermoelectric conversion module housing part 31. A passage portion 33 through which a lead wire connected to the module 1 is inserted is provided.

  In the gas power generator 20 having such a configuration, the high temperature gas supplied to the gas passage 23 gives high temperature heat to the thermoelectric conversion module 1 through the gas passage walls 30 and 30, and further from the cooling medium supply passage 25. The cooling medium that is supplied to the cooling medium passages 28a, 28a,... And flows meandering while intersecting the high temperature gas gives the refrigerant heat to the thermoelectric conversion module 1 via the cooling medium passage walls 32, 32. And the thermoelectric conversion module 1 produces | generates electric power using the temperature difference of the high temperature heat of high temperature gas, and the refrigerant | coolant heat of a cooling medium.

  As described above, in the present embodiment, when the cooling medium intersects and meanders with respect to the flow of the high-temperature gas, the passage partition portions 29, 29,... Are adjacent to each other in the cooling medium passages 28a, 28a,. .., Each of the passage partition portions 29, 29,... Is partitioned by the gas passage walls 30, 30 and the cooling medium passage walls 32, 32, and the thermoelectrics formed between the partitioned walls 29, 29,. Since the thermoelectric conversion module 1 is housed in the conversion module housing portion 31 and its rigidity and surface contactability are maintained high, the thermoelectric conversion module 1 is maintained in a stable manner to improve the thermal conductivity, and the thermoelectric conversion. Efficiency can be further improved and more power can be generated.

  FIG. 6 is a perspective view showing a second embodiment of the gas power generator according to the present invention.

  The gas power generation apparatus 20 according to the present embodiment is a combination of at least two gas power generation apparatuses, that is, a first gas power generation apparatus 20a and a second gas power generation apparatus 20b.

  Both the first gas power generation apparatus 20a and the second gas power generation apparatus 20b, as in the first embodiment, supply the hot gas 22 along the axial direction of the box-shaped main body cylinders 21a and 21b and the main body cylinders 21a and 21b. Gas passages 23a and 23b to be passed, cooling medium supply paths 25a and 25b for supplying the cooling medium 24 to the main body cylinders 21a and 21b, and cooling medium supply paths 25a and 25b for supplying the cooling medium 24 to the main body cylinders 21a and 21b. And cooling medium discharge paths 26a and 26b for discharging the hot medium 22 in the main body cylinders 21a and 21b and the cooling medium 24 after thermoelectric conversion to the outside.

  In addition, air 34 is supplied as a refrigerant to a cooling medium supply path 25a provided in the main body cylinder 21a of the first gas power generation apparatus 20a, and an exhaust gas 35 of a solid oxide fuel cell (not shown) is supplied as a high-temperature gas to the gas path 23a. Supplied.

  Further, the fuel gas 36 is supplied as a refrigerant to the cooling medium supply path 25b provided in the main body cylinder 21b of the second gas power generation device 20b, and the exhaust gas 35 of the solid oxide fuel cell is supplied as the high temperature gas to the gas passage 23b.

  In this case, the air 34 and the fuel gas 36 may be mixed, and the fuel gas may be city gas, hydrogen gas, or carbon monoxide gas.

  In addition, since each main body trunk | drum 21a, 21b is the same as that of the structure of 1st Embodiment, description is abbreviate | omitted here.

  As described above, in the present embodiment, the gas power generation device 20 is configured by combining at least two of the first gas power generation device 20a and the second gas power generation device 20b, and the cooling medium supply paths 25a and 25b and the gas path. Since the fluids supplied by 23a and 23b are made different, it is possible to cope with thermoelectric conversion by selecting a wide variety of fluid types.

  FIG. 7 is a schematic system diagram showing an embodiment of a fuel cell system combined with a gas power generation apparatus according to the present invention.

  The fuel cell system combined with the gas power generation device according to the present embodiment includes, for example, at least two gas power generation devices 20 including, for example, a first gas power generation device 21a and a second gas power generation device 21b illustrated in FIG. The power plant 43 is configured by combining a solid electrolyte fuel cell main body 37.

  Among the power generation plants 43, one of the gas power generation devices 20 uses the exhaust gas 35 from the fuel cell main body 37 as a high-temperature gas, uses air 34 as a cooling medium, and, for example, a blower 38 that sucks air from the atmosphere. And an air flow rate control unit 39 that controls the flow rate so as to balance the sucked air 34 with the flow rate of the exhaust gas 35 from the fuel cell main body 37, and the rotation of the blower 38 based on a command from the air flow rate control unit 39. The number is adjusted up or down.

  Another one of the gas power generation devices 20 uses the exhaust gas 35 from the fuel cell main body 37 as a high temperature gas, and uses, for example, city gas (fuel gas) 40 as a cooling medium, and is included in the city gas 40. And a city gas flow rate control unit 42 for controlling the flow rate of the supplied city gas 40 to balance the supplied city gas 40 with the flow rate of the exhaust gas 35 from the fuel cell body 37. The flow rate of the city gas 40 is controlled by the unit 42. The cooling medium may be selected from a mixed gas of hydrogen and air, a mixed gas of fuel gas and air, or a mixed gas of carbon monoxide and air instead of the city gas 40. Good.

  The city gas flow rate control unit 42 controls the flow rate, and the city gas 40 is supplied to the power generation device 20 including at least two first gas power generation devices 20a and 20b, where thermoelectric conversion is performed. .

  In this thermoelectric conversion, the exhaust gas 35 from the fuel cell main body 37 is used as a high-temperature gas, and a temperature difference with the city gas 40 as a cooling medium is used, so that the thermoelectric conversion module (not shown) shown in FIGS. To convert electric energy into electric energy and generate electric power.

  The city gas 40 after the thermoelectric conversion is reformed into a fuel gas rich in hydrogen concentration by the reformer 44, and chemically reacts with oxygen gas in the fuel cell main body 37 to generate electric power.

  The p-type semiconductor chip 2 and the n-type semiconductor chip 3 of the thermoelectric conversion module 1 incorporated in the gas power generation apparatus 20 (20a, 20b) are rare earth elements, actinoids, cobalt, iron, rhodium, ruthenium, palladium, platinum, nickel. , Antimony, titanium, zirconium, hafnium, nickel, tin, cobalt, silicon, manganese, zinc, boron, carbon, nitrogen, gallium, germanium, indium, vanadium, niobium, barium, magnesium, bismuth, tellurium, selenium, lead At least three elements are selected.

  The p-type semiconductor chip 2 -n-type semiconductor chip 3 includes germanium-silicon, bismuth-tellurium, bismuth-antimony, bismuth-tellurium-antimony, zinc-antimony, cobalt-antimony, iron-antimony, iron-silicon, lead. -Either tellurium or boron-carbon may be the main component.

  The p-type semiconductor chip and the n-type semiconductor chip 3 may be any of manganese-silicon, skutterudite, filled skutterudite crystal structure, Heusler crystal structure, half-Heusler crystal structure, and clathrate crystal structure.

  As described above, the present embodiment includes the gas power generation device 20 (20a, 20b) and the fuel cell main body 37 that both generate electric power and supplies the high temperature to the thermoelectric conversion module 1 of the gas power generation device 20 (20a, 20b). Since the gas and the exhaust gas 35 from the fuel cell main body 37 are obtained and energy is effectively used, the thermoelectric conversion efficiency of the gas power generation apparatus 20 (20a, 20b) can be further improved.

The conceptual diagram which takes out one of the thermoelectric conversion modules integrated in the gas power generation device which concerns on this invention, and demonstrates the principle. 1 is an external view showing a first embodiment of a gas power generator according to the present invention. FIG. 3 is a longitudinal sectional view of the gas power generator according to the present invention shown in FIG. 2. The figure which extracted the thermoelectric conversion module among the gas power generators which concern on this invention. FIG. 5 is a cross-sectional view of the gas power generator according to the present invention shown in FIG. 4. The external view which shows 2nd Embodiment of the gas power generator which concerns on this invention. 1 is a system diagram showing an embodiment of a fuel cell system combined with a gas power generator according to the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Thermoelectric conversion module 2 p-type semiconductor chip 3 n-type semiconductor chip 4 Thermoelectric conversion element 5 High temperature side electrode 6 Low temperature side electrode 7 High temperature side insulating plate 8 Low temperature side insulating plate 9 Electrode current coupling part 10 Current extraction part 11 High temperature side semiconductor Chip connection portion 12 Low-temperature side semiconductor chip connection portions 13, 14, 15 Heat flow 16 Hole 17 Electron 18 Current flow 19 Electric load portion 20 Gas power generation device 20a First gas power generation device 20b Second gas power generation devices 21, 21a, 21b Main body body 22 High-temperature gas 23, 23a, 23b Gas passage 24 Cooling medium 25, 25a, 25b Cooling medium supply passage 26, 26a, 26b Cooling medium discharge passage 27 Cooling medium passage opening 28 Cooling medium bag passage portion 28a Cooling medium passage 29 Passage section 30 Gas passage wall 31 Thermoelectric conversion module housing part 32 Cooling medium passage wall 33 Passage part 34 Air 35 Exhaust gas 3 Fuel gas 37 fuel cell body 38 blower 39 air flow control unit 40 city gas 41 desulfurizer 42 city gas flow rate control unit 43 power plant 44 reformer

Claims (7)

A gas passage that allows high-temperature gas to flow through the central part of the body body, and a thermoelectric conversion module that is defined by a cooling medium passage wall outside the gas passage and that includes a p-type semiconductor chip and an n-type semiconductor chip. And a cooling medium passage that is adjacent to the passage partitioning portion and that passes through the meandering air while crossing the cooling medium with respect to the flow of the high-temperature gas. A gas power generator characterized by that. 2. The gas power generator according to claim 1, wherein the cooling medium passage includes a cooling medium passage opening communicating with the cooling medium supply passage at one end and a cooling medium bag passage portion at the other end. Means for combining a fuel cell with at least two gas power generation devices and supplying exhaust gas from the fuel cell as a high temperature gas to the gas power generation device; and fuel gas, air, hydrogen as a cooling medium for the gas power generation device And a gas power generation device characterized by comprising: means for selectively supplying one of a mixed gas of air and air, a mixed gas of fuel gas and air, and a mixed gas of carbon monoxide and air Battery system. 4. The fuel cell system combined with the gas power generator according to claim 3, wherein the gas power generator comprises a blower and an air flow rate control unit for controlling the amount of air sucked by the blower. The fuel cell includes a desulfurizer, a fuel gas flow rate control unit that controls a flow rate of the fuel gas that has passed through the desulfurizer, and a reformer that reforms the fuel gas into hydrogen gas. A fuel cell system combined with the gas power generation device according to Item 3. The p-type semiconductor chip and n-type semiconductor chip constituting the thermoelectric conversion module are rare earth elements, actinides, cobalt, iron, rhodium, ruthenium, palladium, platinum, nickel, antimony, titanium, zirconium, hafnium, nickel, tin, cobalt, It is characterized by selecting at least three elements among silicon, manganese, zinc, boron, carbon, nitrogen, gallium, germanium, indium, vanadium, niobium, barium, magnesium, bismuth, tellurium, selenium and lead. The gas power generator according to claim 1. The p-type semiconductor chip and the n-type semiconductor chip constituting the thermoelectric conversion module are selected from a skutterudite crystal structure, a Heusler crystal structure, a half-Heusler crystal structure, and a clathrate crystal structure. Item 2. A gas power generation device according to item 1.

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