JP6675899B2 - Exhaust gas power generation unit - Google Patents

Description

  The present invention relates to an exhaust gas power generation unit provided with a thermoelectric conversion element that performs thermoelectric conversion by the Seebeck effect in a flow path of exhaust gas.

  The thermoelectric conversion module is a module including a thermoelectric conversion element that can convert heat energy into electric energy by the Seebeck effect. By utilizing such energy conversion properties, it is possible to convert waste heat discharged from industrial / consumer processes and moving objects into effective electric power. Attention has been focused on modules and thermoelectric conversion elements constituting the modules.

  Such a thermoelectric conversion module is generally configured by joining a plurality of thermoelectric conversion elements (p-type semiconductor and n-type semiconductor) with electrodes. Such a thermoelectric conversion module is disclosed, for example, in Patent Document 1. In addition, such a thermoelectric module is disposed downstream of a high-temperature heat source such as an engine in order to generate electric power by using waste heat of exhaust gas in an automobile and other industrial equipment including an engine. The use of such a thermoelectric conversion module and a thermoelectric conversion device using the thermoelectric conversion module are disclosed in Patent Document 2, for example.

JP 2013-115359 A JP 2007-221895 A

  However, the exhaust gas from the engine goes downstream (ie, on the exhaust side), and the amount of heat is insufficient due to the decrease in temperature. There has been a problem that it is not possible to improve the amount of power generated by itself.

  The present invention has been made in view of such a problem, and aims at absorbing heat with excellent thermal energy efficiency even in the downstream while utilizing the flow of exhaust gas, and reducing the amount of power generation as a whole. An object of the present invention is to provide an exhaust gas power generation unit that can be improved.

  In order to achieve the above object, an exhaust gas power generation unit of the present invention is an exhaust gas power generation unit provided between an engine unit and an exhaust unit, wherein the engine unit and the exhaust unit are connected, and the exhaust gas is discharged from the engine unit. Connecting pipe forming a flow path of exhaust gas to be discharged, a plurality of thermoelectric conversion modules provided on the inner surface of the connecting pipe near the engine unit and near the exhaust unit, and the engine of the connecting pipe Flow rate increasing means for increasing the flow rate of the exhaust gas in the vicinity of the exhaust unit of the connection pipe compared to the flow rate of the exhaust gas in the vicinity of the unit.

  In the exhaust gas power generation unit described above, the flow rate increasing means may reduce an opening dimension of the connection pipe from the engine unit side to the exhaust unit side, and may extend from an area near a center line of the connection pipe to the inside surface. At least one wind guide plate for guiding the exhaust gas. In any case, even in the thermoelectric conversion module located on the downstream side, heat absorption can be achieved with better thermal energy efficiency, and the power generation amount of the entire exhaust gas power generation unit can be improved.

  In the exhaust gas power generation unit including the above-described air guide plate, the air guide plate includes an opening in a region that intersects with a center line of the connection pipe, and each of the thermoelectric conversion modules from an upstream side of the exhaust gas passage. It may extend toward. On the other hand, the air guide plate may narrow the flow path of the exhaust gas from the engine unit side to the exhaust unit side of the connection pipe. In any case, even in the thermoelectric conversion module located on the downstream side, heat absorption can be achieved with more excellent thermal energy efficiency, and the power generation amount of the exhaust gas power generation unit as a whole can be further improved.

  ADVANTAGE OF THE INVENTION According to the exhaust gas power generation unit which concerns on this invention, while utilizing the flow of an exhaust gas, it can aim at heat absorption with excellent thermal energy efficiency downstream, and can improve the electric power generation as a whole.

FIG. 2 is a schematic top view including the exhaust gas power generation unit according to the first embodiment and other units. FIG. 2 is a schematic side view including an exhaust gas power generation unit according to the first embodiment and other units. FIG. 9 is a schematic top view including an exhaust gas power generation unit according to a second embodiment and other units. FIG. 7 is a schematic side view including an exhaust gas power generation unit according to a second embodiment and other units. FIG. 10 is a schematic top view including an exhaust gas power generation unit according to a third embodiment and other units. FIG. 13 is a schematic side view including an exhaust gas power generation unit according to a third embodiment and other units.

  Hereinafter, with reference to the drawings, embodiments of an exhaust gas power generation unit according to the present invention will be described in detail based on examples. The present invention is not limited to the contents described below, and can be arbitrarily changed and implemented without changing the gist. In addition, the drawings used in the description of each embodiment schematically show the exhaust gas power generation unit according to the present invention and the components thereof, and are partially emphasized, enlarged, reduced, omitted, etc. for better understanding. Is performed, and the scale, shape, and the like of each component may not be accurately represented. Furthermore, various numerical values used in each embodiment are merely examples, and can be variously changed as needed.

<Example 1>
Hereinafter, the structure of the exhaust gas power generation unit 1 according to the present embodiment will be described with reference to FIGS. 1 and 2. Here, FIG. 1 is a schematic top view including the exhaust gas power generation unit 1 according to the present embodiment and other units. In particular, the internal structure of the exhaust gas power generation unit 1 is visualized. FIG. 2 is a schematic side view including the exhaust gas power generation unit 1 according to the present embodiment and other units.

  As can be seen from FIGS. 1 and 2, the exhaust gas power generation unit 1 according to the present embodiment is provided between an engine unit 2 of an industrial device including a passenger car or another engine and an exhaust unit 3. Further, the exhaust gas power generation unit 1 has a connection pipe 11 which is a pipe connecting the engine unit 2 and the exhaust unit 3 and forms a flow path of exhaust gas discharged from the engine unit 2. Further, the exhaust gas power generation unit 1 has six thermoelectric conversion modules 12 provided on the inner side surface of the connection pipe 11. Note that the number of the thermoelectric conversion modules 12 is not limited to six, and can be appropriately changed according to the size of the exhaust gas power generation unit 1, the required power generation amount, and the size of the thermoelectric conversion module 12.

  As can be seen from FIG. 1, in the connection pipe 11, the width of the flow path of the exhaust gas gradually widens from the connection portion with the engine unit 2 and expands to a desired width, and then toward the connection portion of the exhaust unit 3. Its width is gradually narrowing. That is, although the connection pipe 11 has its width once widened at the connection portion with the engine unit 2, the flow path of the exhaust gas is gradually narrowed from the engine unit 2 side to the exhaust unit 3 side. Further, as can be seen from FIG. 2, in the connection pipe 11, the height of the exhaust gas flow path gradually decreases from the engine unit 2 side to the exhaust unit 3 side. That is, also in the height direction of the connection pipe 11, the flow path of the exhaust gas is gradually narrowed from the engine unit 2 side to the exhaust unit 3 side. From the above, although the opening size of the connection pipe 11 once increases in the vicinity of the engine unit 2, the overall structure of the connection pipe 11 is such that the opening size increases from the engine unit 2 side to the exhaust unit 3 side. Is smaller.

  Due to such a shape of the connection pipe 11, the high-temperature exhaust gas discharged from the engine unit 2 once spreads inside the connection pipe 11, but flows so as to converge toward the exhaust unit 3. That is, the flow rate of the exhaust gas increases as it goes toward the exhaust unit 3. In other words, the flow velocity of the exhaust gas in the vicinity of the exhaust unit 3 of the connection pipe 11 increases as compared with the flow velocity of the exhaust gas in the vicinity of the engine unit 2 of the connection pipe 11. Therefore, such a shape of the connection pipe 11 functions as a flow rate increasing means for increasing the flow rate of the exhaust gas. Note that, due to the shape of the connection pipe 11, the flux density of the exhaust gas also increases on the exhaust unit 3 side.

  As the material of the connection pipe 11, one having heat resistance and relatively low thermal conductivity is used. Thus, the temperature of the exhaust gas does not decrease, and the power generation in the thermoelectric conversion module 12 can be performed efficiently.

  As the thermoelectric conversion module 12, for example, a known module in which a plurality of thermoelectric conversion elements (p-type semiconductor and n-type semiconductor) are electrically connected in series via electrodes can be used. The thermoelectric conversion modules 12 are juxtaposed on the inner side surface of the connection pipe 11. The structure of the thermoelectric conversion module 12 is not limited, and various known types can be used.

  In the exhaust gas power generation unit 1 according to the present embodiment, due to the shape of the connection pipe 11 described above, the flow velocity of the exhaust gas on the downstream side of the flow path increases as compared with that on the upstream side. In other words, on the downstream side of the flow path of the exhaust gas, the heat flux is increased as compared with the case where the shape of the connection pipe 11 is not narrowed toward the end. For this reason, even when the temperature of the exhaust gas decreases on the downstream side, the thermal energy can be concentrated on the thermoelectric conversion module 12 disposed on the downstream side. A sufficient amount of heat is also supplied to the conversion module 12, and the heat absorption efficiency can be improved.

  In the present embodiment, the opening shape of the connection pipe 11 is trapezoidal, but a cylindrical pipe having a circular opening shape of the connection pipe 11 may be used. Even in this case, it is necessary to form the end of the connection pipe located on the exhaust unit 3 side narrower than the other end located on the engine unit 2 side (that is, to reduce the opening size). is there. In addition, the installation location of the thermoelectric conversion module 12 is not limited to the inner side surface of the connection pipe 11, and may be, for example, the upper surface or the bottom surface of the connection pipe 11. You can choose.

<Example 2>
In the first embodiment, the shape of the connection pipe 11 functions as the flow velocity increasing means. However, a baffle plate (also referred to as a baffle body or a baffle plate) for guiding exhaust gas is provided to increase the flow velocity of the baffle plate. You may function as a means. Hereinafter, an exhaust gas power generation unit 101 having such a baffle plate will be described as a second embodiment with reference to FIGS. 3 and 4. Here, FIG. 3 is a schematic top view including the exhaust gas power generation unit 101 according to the present embodiment and other units, and particularly shows the internal structure of the exhaust gas power generation unit 101 in a visualized manner. FIG. 4 is a schematic side view including the exhaust gas power generation unit 101 according to the present embodiment and other units.

  As can be seen from FIGS. 3 and 4, the exhaust gas power generation unit 101 according to the present embodiment is also provided between the engine unit 102 of the industrial equipment including the passenger car or other engine and the exhaust unit 103. Further, the exhaust gas power generation unit 101 has a connection pipe 111 that connects the engine unit 102 and the exhaust unit 103 and forms a flow path of exhaust gas discharged from the engine unit 102. Further, the exhaust gas power generation unit 101 has six thermoelectric conversion modules 112 provided on the inner side surface of the connection pipe 111.

  As can be seen from FIG. 3, in the connection pipe 111, the width of the flow path of the exhaust gas gradually increases from the connection portion with the engine unit 2, and when the width increases to a desired width, the dimension is maintained, and the connection with the exhaust unit 103 is maintained. The width gradually decreases from the vicinity of the connection part toward the exhaust unit 103. That is, the connection pipe 111 has a width that once widens at the connection with the engine unit 2 and gradually decreases at the connection with the exhaust unit 103, but the width is constant over most of the connection pipe 111. It is kept in. Further, as can be seen from FIG. 4, in the connection pipe 111, the height of the exhaust gas flow path gradually decreases from the engine unit 102 side toward the exhaust unit 103 side. That is, in the height direction of the connection pipe 111, the flow path of the exhaust gas is gradually narrowed from the engine unit 102 side to the exhaust unit 103 side. Further, the material of the connection tube 111 is the same as that of the connection tube 11 of the first embodiment, and a material having heat resistance and relatively low thermal conductivity is used.

  As the thermoelectric conversion module 112, similarly to the thermoelectric conversion module 12 of the first embodiment, a known module in which a plurality of thermoelectric conversion elements are electrically connected in series via electrodes can be used. The thermoelectric conversion modules 112 are also provided side by side on the inner side of the connection pipe 111.

  As shown in FIG. 3, three air guide plates 121, 122, and 123 are provided inside the connection pipe 111. Specifically, each air guide plate is provided from the upstream side of the flow path of the exhaust gas (that is, the connection pipe 111) to each thermoelectric conversion module 112.

  The air guide plate 121 is disposed further upstream than the thermoelectric conversion module 112 located at the most upstream position and near the inner side surface of the connection pipe 111. The air guide plate 121 is composed of two plate-like members extending linearly from the vicinity of the inner side surface of the connection pipe 111 to the thermoelectric conversion module 112 (located on the left side in FIG. 3) located at the most upstream position. It comprises 121a and 121b. That is, the air guide plate 121 has a structure in which the plate-like members 121a and 121b are separated from each other in the vicinity of and around the center line O. In other words, the air guide plate 121 has an opening 121c in a region intersecting with the connection pipe 111.

Further, the baffle plate 122 is disposed inside the baffle plate 121, that is, such that a part thereof is surrounded by the baffle plate 121.
The air guide plate 122 linearly extends from the vicinity of the center line O (shown by a broken line in FIG. 3) of the connection pipe 111 to the thermoelectric conversion module 112 (located in the center in FIG. 3) located in the middle stream. It is composed of two extending plate-like members 122a and 122b. That is, the air guide plate 122 has a structure in which the plate members 122a and 122b are separated from each other near the center line O. In other words, the air guide plate 122 has an opening 122c in a region intersecting with the connection pipe 111. Further, the length of the air guide plate 122 is larger than the length of the air guide plate 121.

  Further, the air guide plate 123 is disposed inside the air guide plates 121 and 122, that is, a part thereof is surrounded by the air guide plates 121 and 122. The air guide plate 123 includes two plate-like members extending linearly from the vicinity of the center line O of the connection pipe 111 toward the thermoelectric conversion module 112 (located to the right in FIG. 3) located at the most downstream position. 123a and 123b. That is, similarly to the air guide plate 122, the air guide plate 123 also has a structure in which the plate members 123a and 123b are separated near the center line O. In other words, the air guide plate 123 has an opening 123c in a region intersecting with the connection pipe 111. Further, the length of the air guide plate 123 is larger than the lengths of the air guide plates 121 and 122.

  That is, each of the air guide plates 121, 122, and 123 extends from the upstream side of the exhaust gas channel toward each of the thermoelectric conversion modules 112. Due to the structure and arrangement of the wind guide plates 121, 122, and 123, a part of the exhaust gas (indicated by the thickest arrow in FIG. 3) flowing from the upstream side is formed by the connection pipe 111 and the wind guide plate 121. The flow is guided toward the thermoelectric conversion module 112 located at the uppermost stream via the flow path. Further, a part of the exhaust gas flowing from the upstream side passes through a flow path formed by the baffle plate 121 and the baffle plate 122, and the thermoelectric conversion module 112 located at the uppermost stream and the thermoelectric conversion module 112 located at the center It is guided toward. Further, part of the exhaust gas flowing from the upstream side passes through a flow path formed by the baffle plate 122 and the baffle plate 123, and the thermoelectric conversion module 112 located at the center and the thermoelectric conversion module 112 located at the most downstream position. It is guided toward. Therefore, the exhaust gas discharged from the engine unit 102 is guided to both sides of the connection pipe 111 along the air guide plates 121, 122, and 123, and is directed toward the thermoelectric conversion module 112 provided on the inner side surface of the connection pipe 111. The heat is absorbed by the thermoelectric conversion module 112 with excellent thermal energy efficiency.

  Moreover, although the high-temperature exhaust gas discharged from the engine unit 2 once spreads on the upstream side in the connection pipe 111 due to such wind guide plates 121, 122, and 123, the installation location of the wind guide plates 121, 122, and 123 and On the downstream side, the water flows so as to converge toward the side of the connection pipe 111. That is, the flow rate of the exhaust gas increases as it goes toward the exhaust unit 103. In other words, the flow velocity of the exhaust gas in the vicinity of the exhaust unit 103 of the connection pipe 111 increases as compared with the flow velocity of the exhaust gas in the vicinity of the engine unit 102 of the connection pipe 111. Therefore, such air guide plates 121, 122, and 123 function as flow rate increasing means for increasing the flow rate of exhaust gas. Note that the air guide plates 121, 122, and 123 also increase the flux density of the exhaust gas on the exhaust unit 103 side.

  In the exhaust gas power generation unit 101 according to the present embodiment, the flow velocity of the exhaust gas on the downstream side is increased by the above-described baffle plates 121, 122, and 123 as compared with the upstream side. In other words, the heat flux increases on the downstream side of the exhaust gas flow path as compared with the case where the air guide plates 121, 122, 123 are not present. For this reason, even when the temperature of the exhaust gas decreases on the downstream side, the thermal energy can be concentrated on the thermoelectric conversion module 112 disposed on the downstream side, so that the thermoelectric module disposed on the downstream side can be concentrated. A sufficient amount of heat is also supplied to the conversion module 112, so that the heat absorption efficiency can be improved.

  In the present embodiment, each of the air guide plates 121, 122, and 123 is composed of two plate members. However, the present invention is not limited to this. It may be configured by bending and forming an opening as necessary, or may be configured by two or more plate-shaped members. In the present embodiment, the air guide plates 121, 122, and 123 guide the exhaust gas to both sides of the connection pipe 111. However, when the thermoelectric conversion module 112 is also provided on the top and bottom surfaces of the connection pipe 111, Alternatively, a structure for guiding exhaust gas to the upper and lower surfaces of the connection pipe 111 may be provided. In such a case, the shape of the connection pipe 111 may be a rectangular tube. Further, the outer shape of the connection pipe 111 may be narrowed toward one end (that is, downstream of the flow path of the exhaust gas) as in the connection pipe 11 of the first embodiment. Each plate-like member constituting each wind guide plate may have a curved shape instead of a straight shape. Further, the opening 123c may not be formed in the air guide plate 123. As a result, all the exhaust gas discharged from the engine unit 102 is guided to both sides of the connection pipe 111, so that it is possible to further improve the power generation efficiency.

<Example 3>
In the second embodiment, the three air guide plates 121, 122, and 123 function as flow velocity increasing means, but one air guide plate may function as flow velocity increasing means. Hereinafter, an exhaust gas power generation unit 201 having such a baffle plate will be described as a third embodiment with reference to FIGS. 5 and 6. Here, FIG. 5 is a schematic top view including the exhaust gas power generation unit 201 according to the present embodiment and other units, and particularly shows a visualized structure inside the exhaust gas power generation unit 201. FIG. 6 is a schematic side view including the exhaust gas power generation unit 201 according to the present embodiment and other units.

  As can be seen from FIGS. 5 and 6, the exhaust gas power generation unit 201 according to the present embodiment is also provided between the engine unit 202 of the industrial equipment including the passenger car or other engine and the exhaust unit 203. Further, similarly to the exhaust gas power generation unit 101 of the second embodiment, the exhaust gas power generation unit 201 includes a connection pipe 211 and six thermoelectric conversion modules 212 provided on a side surface inside the connection pipe 211. Note that the shape and material of the connection pipe 211 are the same as those of the connection pipe 111 of the second embodiment, and the thermoelectric conversion module 212 is the same as the thermoelectric conversion module 112 of the second embodiment.

  As shown in FIG. 5, a baffle plate 224 is provided inside the connection pipe 211. Specifically, a triangular prism-shaped baffle plate 224 is disposed downstream from the center of the exhaust gas flow path (that is, the connection pipe 211). The air guide plate has side surfaces 224 a and 224 b extending from the center line O (indicated by a broken line in FIG. 5) of the connection tube 211 toward the inside surface of the connection tube 211. That is, the air guide plate 224 has a structure that narrows the flow path of the exhaust gas from the engine unit 202 side of the connection pipe 211 to the exhaust unit 203 side. The shape of the air guide plate 224 is not limited to a triangular prism shape, and may be a structure having another shape as long as the flow path of the exhaust gas can be gradually narrowed downstream. It can be changed as appropriate depending on the opening shape of the connection pipe 211.

  Due to such a shape of the air guide plate 224, the high-temperature exhaust gas discharged from the engine unit 202 spreads once in the connection pipe 211, but flows so as to converge toward the exhaust unit 203. That is, the flow rate of the exhaust gas increases as it goes toward the exhaust unit 203. In other words, the flow velocity of the exhaust gas in the vicinity of the exhaust unit 203 of the connection pipe 211 is increased as compared with the flow velocity of the exhaust gas in the vicinity of the engine unit 202 of the connection pipe 211. Therefore, such a shape of the air guide plate 224 functions as a flow rate increasing unit that increases the flow rate of the exhaust gas. The flux density of the exhaust gas also increases on the exhaust unit 203 side due to the shape of the air guide plate 224.

  In the exhaust gas power generation unit 201 according to this embodiment, due to the shape of the baffle plate 224 described above, the flow velocity of the exhaust gas on the downstream side of the flow path increases as compared with that on the upstream side. In other words, the heat flux increases on the downstream side of the exhaust gas flow path as compared with the case where the air guide plate 224 is not provided. For this reason, even when the temperature of the exhaust gas decreases on the downstream side, the thermal energy can be concentrated on the thermoelectric conversion module 212 disposed on the downstream side. A sufficient amount of heat is also supplied to the conversion module 212, and the heat absorption efficiency can be improved.

DESCRIPTION OF SYMBOLS 1 Exhaust gas power generation unit 2 Engine unit 3 Exhaust unit 11 Connection pipe 12 Thermoelectric conversion module 101 Exhaust gas power generation unit 102 Engine unit 103 Exhaust unit 111 Connection pipe 112 Thermoelectric conversion module 121 Wind guide plate 122 Wind guide plate 123 Wind guide plate 201 Exhaust gas generation unit 202 Engine unit 203 Exhaust unit 211 Connection pipe 212 Thermoelectric conversion module 224 Wind guide plate

Claims (4)

An exhaust gas power generation unit provided between the engine unit and the exhaust unit,
A connection pipe that connects the engine unit and the exhaust unit and forms a flow path of exhaust gas discharged from the engine unit;
A plurality of thermoelectric conversion modules provided on the inner surface of the connection pipe near the engine unit and near the exhaust unit;
Compared to the flow rate of the exhaust gas in the vicinity of the engine unit of said connection tube, it has a, and the flow velocity increasing means for increasing the flow rate of the exhaust gas in the vicinity of the exhaust unit of the connection tube,
The flow velocity increasing means is at least one baffle plate that guides the exhaust gas from a region near a center line of the connection pipe toward an inner surface,
The exhaust gas power generation unit , wherein the air guide plate includes an opening in a region intersecting with a center line of the connection pipe, and extends from an upstream side of a flow path of the exhaust gas toward each of the thermoelectric conversion modules .   The exhaust gas power generation unit according to claim 1, wherein the air guide plate extends linearly from an upstream side of the flow path of the exhaust gas toward each of the thermoelectric conversion modules. Said connection tube, the direction from the engine unit side to the exhaust unit side, the opening size is reduced, the exhaust gas generator unit according to claim 1 or 2. The baffle plate is toward the exhaust unit side from the engine unit side of the connecting pipe, an exhaust gas generator unit according to any one of claims 1 to 3 to narrow the flow path of the exhaust gas.

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