JP2014100042A - Alkali metal thermoelectric transducer and operating method thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To increase a power generation voltage per unit volume of a β alumina solid electrolyte member (BASE) by enlarging an ion driving force without further elevating the temperature of a heat receiving part.SOLUTION: An alkali metal thermoelectric transducer 10 comprises: a sealed container 12 which includes a heat receiving part B exposed under a high-temperature fluid and a heat dissipating part C exposed under a low-temperature fluid and in which a circulation path of an alkali metal is defined to pass these parts B and C; a β alumina solid electrolyte member 30 disposed within the sealed container 12 so as to divide the circulation path at a high-temperature part which is a portion corresponding to the heat-receiving part in the circulation path, into a high-temperature part upstream side at an upstream side and a high-temperature part downstream side at a downstream side; a cathode member 34 disposed at the high-temperature part upstream side; and an anode member 31 disposed at the high-temperature part downstream side. The sealed container 12 is rotated around a rotation axial line A so as to increase a pressure difference between both sides of the β alumina solid electrolyte member 30 by a centrifugal force.

Description

  The present invention relates to an alkali metal thermoelectric converter and an operation method thereof, and more particularly to an alkali metal thermoelectric converter using a β alumina solid electrolyte member and an operation method thereof.

  As a thermoelectric converter, an alkali metal thermoelectric converter (AMTEC) using a β alumina solid electrolyte member having ion conductivity of alkali metal such as sodium (Na) is known (for example, Patent Document 1).

  The AMTEC has a vacuum sealed container having a heat receiving part exposed to a high temperature fluid and a heat radiating part exposed to the low temperature fluid, and an alkali is provided so as to pass through the heat receiving part and the heat radiating part in the sealed container. A metal circulation path is defined, and in the high temperature portion that is a portion corresponding to the heat receiving portion of the circulation path, the hermetic passage is divided into an upstream high temperature section upstream and a downstream high temperature section downstream. A β-alumina solid electrolyte member (BASE) is disposed in the container, a cathode member is disposed upstream of the high temperature part, and an anode member is disposed downstream of the high temperature part.

  The operating principle of AMTEC is that the alkali metal is separated into ions and electrons on the cathode member side, that is, on the upstream side of the high temperature part, and only the ions move in the BASE, and the electrons are powered by an external load connected to the cathode member. Generated toward the anode member. The ions that have passed through the BASE recombine with electrons on the anode member downstream of the high temperature portion of the BASE to become the original alkali metal. The alkali metal on the downstream side of the high temperature part is condensed in the low temperature part, and then continuously transported and circulated to the upstream side of the high temperature part of the BASE by a wick pump or an electromagnetic pump using capillary force.

  The power generation efficiency of AMTEC largely depends on the amount of alkali metal ions passing through BASE. The driving force (ion driving force) through which the alkali metal ions pass through the BASE is determined by the pressure difference between the high temperature part upstream side and the high temperature part downstream side of the BASE.

  In the conventional AMTEC, the above pressure difference is given solely by the alkali metal vapor pressure difference between the heat receiving part and the heat radiating part of the sealed container, that is, the temperature difference between the heat receiving part and the heat radiating part. In addition, the alkali metal is continuously transported to the upstream side of the high temperature portion of the BASE by a wick pump or an electromagnetic pump using a capillary force.

Japanese Patent No. 2601889

  In AMTEC, in order to increase the power generation voltage (output density) per unit volume of BASE without increasing the size, it is necessary to further increase the ion driving force by increasing the pressure difference. On the other hand, in the conventional AMTEC, in order to increase the ion driving force, it is necessary to further increase the temperature of the heat receiving part by using the saturated vapor pressure of alkali metal. However, there is a limit to further increasing the temperature of the heat receiving part from the viewpoint of the thermal durability of the materials that make up the sealed container, etc., and high temperature waste heat is required when the temperature of the heat receiving part is increased by using waste heat. This limits the available waste heat sources.

  As a method of increasing the pressure difference, it is conceivable to increase the pump capacity of the wick pump or the electromagnetic pump. However, the surface tension of the wick pump is limited, and the efficiency of the electromagnetic pump (up to 1 atm) becomes a problem, and energy loss due to electromagnetic heat generation is accompanied.

  The problem to be solved by the present invention is to increase the ion driving force without increasing the temperature of the heat receiving part, to increase the power generation voltage per unit volume of BASE, and to increase the pressure difference so far. It is possible to use a low-temperature heat source that has been difficult to obtain.

  The alkali metal thermoelectric converter according to the present invention has a heat receiving part (B) exposed to a high temperature fluid and a heat radiating part (C) exposed to a low temperature fluid, and the heat receiving part (B) and the heat radiating part ( C) and an airtight container (12) in which an alkali metal circulation path is defined, and a high temperature part corresponding to the heat receiving part (B) of the circulation path. A β alumina solid electrolyte member (30) disposed in the sealed container (12) so as to be divided into a high temperature part upstream side and a downstream high temperature part downstream side, and a cathode member ( 34) and an anode member (31) disposed on the downstream side of the high temperature part, the alkali metal thermoelectric converter upstream of the high temperature part with respect to the pressure of the alkali metal on the downstream side of the high temperature part by centrifugal force The pressure difference on the side increases Having a predetermined rotation axis rotating device for rotating the closed container (12) to (A) around (42) on.

  According to this configuration, the pressure difference between the high temperature part upstream side and the high temperature part downstream side of both sides of the β alumina solid electrolyte member (30) is increased by utilizing centrifugal force, and alkali metal ions are converted into β alumina solid electrolyte member. The driving force passing through (30) increases. Accordingly, separation of alkali metal ions and electrons on the cathode side of the β-alumina solid electrolyte member (30) is promoted, and the β-alumina solid electrolyte member (30) can be obtained without further increasing the temperature of the heat receiving portion (B). The generated voltage per unit volume of becomes higher.

  In the alkali metal thermoelectric converter according to the present invention, preferably, the upstream side of the high temperature portion includes a portion disposed radially outward of the rotation axis A from the low temperature portion.

  According to this configuration, the alkali metal is transported from the low temperature part to the high temperature part upstream side by the centrifugal force caused by the rotation of the sealed container (12) around the rotation axis (A), and the both sides of the β alumina solid electrolyte member (30) are transported. The pressure difference between the high temperature part upstream side and the high temperature part downstream side increases.

  In the alkali metal thermoelectric converter according to the present invention, preferably, the portion where the low temperature part communicates with the upstream side of the high temperature part is the rotation axis (A) with respect to the part where the low temperature part communicates with the downstream side of the high temperature part. ) Is arranged radially outward.

  According to this configuration, the alkali metal is transported from the low temperature part to the high temperature part upstream side by the centrifugal force caused by the rotation of the sealed container (12) around the rotation axis (A), and the both sides of the β alumina solid electrolyte member (30) are transported. The pressure difference between the high temperature part upstream side and the high temperature part downstream side increases.

  In the alkali metal thermoelectric converter according to the present invention, preferably, the downstream side of the high temperature portion communicates with the low temperature portion radially inward of the rotation axis (A) from the arrangement position of the β alumina solid electrolyte member (30). doing.

  According to this configuration, the low temperature portion can be extended in the radial direction of the rotation axis (A). In addition, since the alkali metal is a gas having a low density on the downstream side of the high temperature part, the alkali metal is hardly affected by the centrifugal force, and can move from the downstream side of the high temperature part to the low temperature part, and the circulation of the alkali metal is not hindered.

  In the alkali metal thermoelectric converter according to the present invention, preferably, the high temperature portion is disposed on one side in the direction along the rotation axis (A) of the sealed container (12), and the low temperature portion is the one of the sealed container. It arrange | positions in the other side in the direction in alignment with a rotating shaft line (A).

  According to this configuration, since the high temperature part and the low temperature part exist on one rotation axis (A), even if the sealed container (12) rotates around the rotation axis (A), the high temperature part and the low temperature part The position in the direction along the rotational axis (A) does not change, the heat receiving part is always located at a fixed position where it is exposed to the high temperature fluid, and the heat radiating part is always located at a fixed position where it is exposed to the high temperature fluid.

  In the alkali metal thermoelectric converter according to the present invention, preferably, the high temperature part is arranged vertically above the low temperature part.

  According to this configuration, gravity acts on the flow of the alkali metal from the high temperature portion to the low temperature portion, the flow of the alkali metal from the high temperature portion to the low temperature portion becomes smooth, and the alkali metal is removed from the low temperature portion in preparation for restart. Can be stored.

  In the alkali metal thermoelectric converter according to the present invention, preferably, convex portions (33, 37) are integrally formed on the surface of the β alumina solid electrolyte (30) on the upstream side of the high temperature portion.

  According to this configuration, the contact area between the β-alumina solid electrolyte (30) and the alkali metal on the upstream side of the high-temperature part of the β-alumina solid electrolyte (30), that is, the anode side is increased by the convex portions (33, 37). Accordingly, as the amount of ions passing through the β-alumina solid electrolyte (30) increases, the amount of electrons separated on the anode side increases, and the power generation capacity increases.

  In the alkali metal thermoelectric converter according to the present invention, preferably, the sealed container (12) includes a disk part (14) defining a disk-shaped hollow part (16) therein, and one of the disk parts (14). A plurality of outer cylinders which are arranged at intervals in the circumferential direction so as to protrude in the axial direction from the outer peripheral portion on the disk surface side and which define a first cylindrical hollow portion (20) communicating with the disc-shaped hollow portion inside A second cylindrical hollow portion (24) projecting in the axial direction from the center portion on the other disc surface side of the portion (18) and the disc portion (14) and communicating with the disc-like hollow portion (16) A first cylindrical hollow portion (16A) and a second hollow cylindrical portion (22) that define the central cylindrical portion (22) and the disk-shaped hollow portion (16) are positioned on the one disk surface side and the other disk surface side, respectively. A disc-shaped inner partition wall (26) partitioned into a disc-shaped hollow portion (16B), and the circle Extending from the center of the inner wall partition (26) to the vicinity of the projecting end of the center tube (22) so as to divide the inside of the center tube (22) in the radial direction, A cylindrical inner partition wall (28) that communicates the disk-shaped hollow portion (16A) in the vicinity of the protruding end of the second cylindrical hollow portion (24), and the β alumina solid electrolyte member (30) The disk-shaped inner partition wall (26) projects into the first cylindrical hollow portion (20) so as to divide the inside of the outer cylindrical portion (18) in the radial direction, and the tip is closed. It is comprised by the cylinder which has an inner chamber (20A) connected to 2 disk shaped hollow parts (16B).

  According to this configuration, a converter having a high generated voltage can be obtained by incorporating a plurality of β-alumina solid electrolyte members (30) in one rotating sealed container (12).

  In the alkali metal thermoelectric converter according to the present invention, preferably, the central tube portion (22) is arranged concentrically with the rotation axis (A).

  According to this configuration, in the rotation around the rotation axis (A) of the sealed container (12), there is no imbalance in the rotation balance due to the eccentric load.

  The alkali metal thermoelectric converter according to the present invention preferably has a throttle part (32) for restricting the flow at a communication part between the first disc-shaped hollow part (16A) and the inside of the central cylinder part (22). ) Is formed.

  According to this configuration, when the sealed container (12) is rotated, the alkali metal in the central cylindrical portion (22) is prevented from flowing back to the first disk-shaped hollow portion (16A).

  In the alkali metal thermoelectric converter according to the present invention, preferably, the central tube portion (22) is formed of a cylindrical body, and an inner peripheral surface (22B) is directed from the disk portion (14) side to a protruding end side. Accordingly, the taper shape has a smaller inner diameter.

  According to this structure, the upward flow component is given to the alkali metal pressed against the inner peripheral surface (22B) by the centrifugal force, and the alkali metal is directed from the center tube portion (22) toward the disk portion (14). The flow becomes smooth.

  In the alkali metal thermoelectric converter according to the present invention, preferably, the cylindrical inner partition wall (28) is formed of a cylindrical body, and an inner peripheral surface (28A) extends from the disk-shaped inner partition wall (26) side. It has a tapered shape in which the inner diameter increases toward the end side.

  According to this structure, the downward flow component is given to the alkali metal pressed against the inner peripheral surface (28A) by the centrifugal force, and the flow of the alkali metal descending in the center tube portion (22) becomes smooth.

  The alkali metal thermoelectric converter according to the present invention, as one example of use, is arranged such that the heat receiving part is capable of exchanging heat with the exhaust gas of the internal combustion engine, and operates using the exhaust gas as a heat source.

  According to this use example, the alkali metal thermoelectric converter operates by using waste heat.

  The operation method of the alkali metal thermoelectric converter according to the present invention includes a heat receiving portion (B) exposed to a high temperature fluid and a heat radiating portion (C) exposed to a low temperature fluid, and the heat receiving portion (B) and the above In the sealed container (12) in which an alkali metal circulation path is defined so as to pass through the heat radiating part (C), and in the high temperature part corresponding to the heat receiving part (B) of the circulation path, Β-alumina solid electrolyte member (30) disposed in the sealed container (12) so as to be divided into an upstream high-temperature part upstream side and a downstream high-temperature part downstream side, and a high-temperature part upstream side An operation method of an alkali metal thermoelectric converter having a cathode member (34) and an anode member (31) arranged on the downstream side of the high temperature part, the pressure against the pressure of the alkali metal on the downstream side of the high temperature part Increased pressure difference upstream of hot section So that the said closed container (12) is rotated to a predetermined rotational axis (A) around it gives centrifugal force to the alkali metal.

  According to this operation method, the pressure difference between the high temperature part upstream side and the high temperature part downstream side of both sides of the β alumina solid electrolyte member (30) is increased by utilizing centrifugal force, and alkali metal ions are converted into β alumina solid electrolyte. The driving force passing through the member (30) increases. Accordingly, separation of alkali metal ions and electrons on the cathode side of the β-alumina solid electrolyte member (30) is promoted, and the β-alumina solid electrolyte member (30) can be obtained without further increasing the temperature of the heat receiving portion (B). The generated voltage per unit volume of becomes higher.

  The operation method of the alkali metal thermoelectric converter according to the present invention is preferably such that the hermetic container (12) is located at a position away from the arrangement position of the β-alumina solid electrolyte member (30) in the rotational radial direction. (A) Rotate around.

  According to this operation method, the centrifugal force acts on the arrangement position of the β-alumina solid electrolyte member (30) by the rotation around the rotation axis (A) of the sealed container (12), and both sides of the β-alumina solid electrolyte member (30) are applied. The pressure difference between the upstream side of the high temperature part and the downstream side of the high temperature part becomes high.

  The operation method of the alkali metal thermoelectric converter according to the present invention preferably increases the pressure difference of the alkali metal between the upstream side and the downstream side of the β alumina solid electrolyte member (30) by the centrifugal force. The magnitude of the centrifugal force is set so as to promote the separation of the alkali metal ions and electrons on the cathode side of the solid electrolyte member (30).

  According to this operation method, the separation of the alkali metal ions and electrons on the cathode side of the β-alumina solid electrolyte member (30) is promoted by centrifugal force.

  According to the alkali metal thermoelectric converter of the present invention, the pressure difference between the high temperature part upstream side and the high temperature part downstream side of both sides of the β alumina solid electrolyte member is increased by utilizing centrifugal force, and the alkali metal ions are converted into β. The driving force passing through the alumina solid electrolyte member is increased. The power generation voltage per unit volume of the β alumina solid electrolyte member is increased without further increasing the temperature of the heat receiving portion.

Sectional drawing which shows 1st Embodiment of the alkali metal thermoelectric converter by this invention. The top view of the alkali metal thermoelectric converter by 1st Embodiment. Sectional drawing which shows 2nd Embodiment of the alkali metal thermoelectric converter by this invention. Sectional drawing which shows 3rd Embodiment of the alkali metal thermoelectric converter by this invention. FIG. 5 is an enlarged sectional view taken along line VV in FIG. 4. Sectional drawing which shows 4th Embodiment of the alkali metal thermoelectric converter by this invention. The top view of the alkali metal thermoelectric converter by 4th Embodiment. The schematic block diagram which shows the usage example of the alkali metal thermoelectric converter by this invention. The schematic block diagram which shows other embodiment of the alkali metal thermoelectric converter by this invention

  Below, 1st Embodiment of the alkali metal thermoelectric converter by this invention is described with reference to FIG. 1, FIG.

  An alkali metal thermoelectric converter (AMTEC) 10 has an airtight container 12 that forms an outer shell. The hermetic container 12 is made of a metal having high thermal conductivity and high heat resistance, such as stainless steel.

  The hermetic container 12 has a single disk portion 14 disposed horizontally. The disk portion 14 defines a disk-shaped hollow portion 16 therein.

  On the disk surface side (upper disk surface) above the disk portion 14, a plurality of outer cylindrical portions 18 projecting vertically upward from the outer peripheral portion of the disk portion 14 in the axial direction are equally spaced in the circumferential direction. It is arranged at a point-symmetrical position with respect to the center. Each of the plurality of outer cylindrical portions 18 has an upper end closed by an upper end wall 18A, and defines a first columnar hollow portion 20 communicating with the disk-shaped hollow portion 16 on the lower end side.

  On the disk surface side (lower disk surface) below the disk portion 14, one central cylindrical portion 22 that protrudes vertically downward from the center portion of the disk portion 14 in the axial direction is disposed. The central cylindrical portion 22 has a lower end closed by a lower end wall 22A and defines a second columnar hollow portion 24 communicating with the disk-shaped hollow portion 16 on the upper end side.

  A disc-shaped inner partition wall 26 is horizontally provided in the disc portion 14. The disk-shaped inner partition wall 26 includes a disk-shaped hollow portion 16 having an upper disk-shaped hollow portion (first disk-shaped hollow portion) 16A positioned on the upper disk surface side and a lower disk-shaped hollow positioned on the lower disk surface side. Section (second disk-shaped hollow portion) 16B.

  A cylindrical inner partition wall 28 is provided vertically in the central cylindrical portion 22 concentrically with the central cylindrical portion 22. The cylindrical inner partition wall 28 protrudes from the center of the disk-shaped inner partition wall 26 into the second cylindrical hollow portion 24 so as to divide the inside of the center cylindrical portion 22 in the radial direction (lower end). ) Extends to the vicinity, and communicates the upper disk-shaped hollow portion 16A with the vicinity of the protruding end (lower end) of the second columnar hollow portion 24 with its own in-cylinder space (inner hollow portion 24A).

  That is, the cylindrical inner partition wall 28 has the second columnar hollow portion 24 connected to the inner hollow portion 24A communicating with the upper disk-shaped hollow portion 16A on the upper end side and the lower disk-shaped hollow portion 16B on the upper end side. It divides into the outer hollow part 24B which connects. The cylindrical inner partition wall 28 is not joined to the lower end wall 22A, and there is a gap between the lower end of the cylindrical inner partition wall 28 and the lower end wall 22A, so that the inner hollow portion 24A and the outer hollow portion 24B are The cylindrical inner partition wall 28 communicates with the lower end side.

  A β-alumina solid electrolyte member (BASE) 30 extending vertically from the disk-shaped inner partition wall 26 into the first cylindrical hollow portion 20 is attached to the disk-shaped inner partition wall 26. The BASE 30 is preferably made of a β ”alumina sintered material having a characteristic (ion conductivity) of conducting alkali metal ions such as sodium (Na) in a high temperature atmosphere.

  The BASE 30 has a cylindrical body with a closed tip (upper end), and is disposed concentrically with the outer cylindrical portion 18 in the outer cylindrical portion 18 so as to divide the outer cylindrical portion 18 in the radial direction, and on the lower end side. The inner chamber 20A communicates with the side disk-shaped hollow portion 16B. An outer chamber 20B communicating with the upper disk-shaped hollow portion 16A is defined between the outer cylindrical portion 18 and the outer cylindrical portion 18 at the lower end side. That is, the BASE 30 includes an inner chamber 20A that communicates the first cylindrical hollow portion 20 with the lower disc-shaped hollow portion 16B at the lower end side, and an outer chamber 20B that communicates with the upper disc-shaped hollow portion 16A at the lower end side. It is divided into.

  The outer chamber 20B is filled with a foam metal body (porous metal body) having a three-dimensional network structure having conductivity and air permeability. The foam metal body includes a cylindrical portion that contacts the outer peripheral surface (cathode side) of the BASE 30 and the inner peripheral surface of the outer cylindrical portion 18 in a conductive relationship, and forms an anode (cathode) member 31. The anode member 31 also serves as a support member that supports the BASE 30 at a predetermined position in the outer cylindrical portion 18 at the same time.

  As described above, in the sealed container 12, the upper disc-shaped hollow portion 16A, the lower disc-shaped hollow portion 16B, the inner chamber 20A, the outer chamber 20B, the inner hollow portion 24A, and the outer hollow portion 24B are defined. The space is filled with an alkali metal such as sodium in a vacuum atmosphere. In FIG. 1, the horizontal broken line pattern portion indicates the presence of liquid alkali metal, and the halftone dot pattern portion indicates the presence of gaseous alkali metal.

  Of the sealed container 12, portions corresponding to the inner chamber 20 </ b> A and the outer chamber 20 </ b> B (the outer cylindrical portion 18), that is, the vertically upper side of the sealed container 12 is a heat receiving part B that is exposed to a high-temperature fluid. On the other hand, the portion corresponding to the inner hollow portion 24A and the outer hollow portion 24B (the central cylindrical portion 22), that is, the vertically lower side of the sealed container 12 is a heat radiating portion C that is exposed to a low-temperature fluid.

  In this way, the alkali metal passes from the inner hollow portion 24A to the outer hollow portion 24B, the lower disc-shaped hollow portion 16B, the inner chamber 20A, the BASE 30, the outer chamber 20B (anode member 31), and the upper disc-shaped hollow portion 16A. Returning to the inner hollow portion 24A, an alkali metal circulation path is defined by a closed loop that passes through the heat radiating portion C and the heat receiving portion B on the way. The BASE 30 is a portion corresponding to the heat receiving part B of the above-described circulation path, and the upstream side of the circulation path is the upstream side of the high temperature part (inner chamber 20A) and the downstream side of the high temperature part (outer chamber 20B). It arrange | positions in the airtight container 12 so that it may divide into. A throttle part 32 for restricting the flow of the alkali metal is formed at the communication part between the upper disk-shaped hollow part 16A and the inner hollow part 24A.

  A rod-shaped cathode (anode) member 34 positioned on the upstream side of the high temperature portion, that is, in the inner chamber 20 </ b> A, is attached to the disk portion 14 via an electrical insulating member 36. The cathode member 34 is conductively connected to the inner peripheral surface (anode side) of the BASE 30 by the conductivity of the liquid alkali metal that fills the inner chamber 20A.

  A rotation center shaft 38 concentric with the central cylindrical portion 22 extending downward from the lower end wall 22A is provided on the lower bottom portion of the sealed container 12, that is, the lower end wall 22A of the central cylindrical portion 22. The rotation center shaft 38 is connected by a coupling 40 to a rotation output shaft (rotor shaft) 44 of an electric motor 42 as a rotating device in a torque transmission relationship. A casing 46 on the stator side of the electric motor 42 is fixed to a fixed side member 48. The electric motor 42 rotates the hermetic container 12 around the rotation axis A extending vertically through the center of the central cylindrical portion 22. The BASE 30 is located at a position radially outward from the rotation axis A.

  A cathode slip ring 52 is attached to the outer peripheral portion of the rotation center shaft 38 via an electrical insulating member 50. The cathode slip ring 52 is conductively connected to the cathode member 34 by a conductive portion 56 and a lead wire 58 formed on the outer peripheral surface of the sealed container 12 via an electric insulating member 54. An anode slip ring 60 is directly attached to the outer peripheral portion of the rotation center shaft 38. The anode slip ring 60 is conductively connected to the anode member 31 by the conductivity of the sealed container 12 itself. Each of the cathode slip ring 52 and the anode slip ring 60 has a structure in which a current collecting brush (not shown) is in sliding contact with each other and can collect current from the rotating sealed container 12 to the outside (fixed side). An external load (not shown) is connected.

  In the present embodiment, the electrical connection between the anode member 31 and the anode slip ring 60 using the electrical conductivity of the sealed container 12 itself, and the electrode conduction avoiding a short circuit with the alkali metal on the low temperature side. The disk-like inner partition wall 26 and the cylindrical inner partition wall 28 are made of an electrically insulating material so that the structure is established, and the disk portion 14 forms the bottom surface of the lower disk-shaped hollow portion 16B and the inner peripheral surface of the central cylindrical portion 22. 22B is insulatively coated with an electrically insulating coating layer 23.

  In the AMTEC 10 having the above-described configuration, the sealed container 12 is rotated around the rotation axis A by the electric motor 42, thereby generating a centrifugal force. Here, the difference in pressure on the upstream side of the high temperature part (inner chamber 20A) with respect to the pressure on the downstream side of the high temperature part of the alkali metal (outer chamber 20B) is increased by centrifugal force, and ions and electrons of alkali metal on the cathode side of the BASE 30 are increased. The rotational speed of the sealed container 12 is set so that a centrifugal force having a magnitude that promotes the separation of the closed container 12 is obtained.

  The alkali metal in the above-described circulation path is condensed from the gas by the heat radiation into the liquid in the outer hollow portion 24B which is the low temperature portion corresponding to the heat radiation portion C. The liquid alkali metal, which has a higher density than the gaseous alkali metal, moves outward along the inner peripheral surface 22B of the central cylindrical portion 22 such that the liquid level rises while being pressed against the inner peripheral surface 22B of the central cylindrical portion 22 by centrifugal force. The hollow portion 24B is lifted and reaches the lower disk-shaped hollow portion 16B. Then, the liquid alkali metal flows radially outward in the lower disc-shaped hollow portion 16B and is transported to the inner chamber 20A on the upstream side of the high temperature portion.

  The liquid alkali metal transported to the inner chamber 20A is separated into alkali metal ions and electrons in the inner chamber 20A, and only the ions move through the BASE 30. The separated electrons move from the cathode member 34 to the external load (not shown) through the cathode slip ring 52, and travel from the external load to the anode member 31 through the anode slip ring 60. The ions that have passed through the BASE 30 recombine with electrons on the anode member 31 in the outer chamber 20B on the downstream side of the high temperature portion, and become gaseous alkali metal.

  The gaseous alkali metal moves inward in the radial direction so as to diffuse through the anode member 31 and diffuse the upper disk-shaped hollow portion 16A against the centrifugal force, and passes through the throttle portion 32 to move down the inner hollow portion 24A. And return to the outer hollow portion 24B. The flow of the gaseous alkali metal is generated by being drawn by the flow of the alkali metal that rises in the outer hollow portion 24B by centrifugal force. The throttle portion 32 prevents the alkali metal in the inner hollow portion 24A from flowing back to the upper disk-shaped hollow portion 16A when the sealed container 12 is rotated and started.

  The centrifugal force generated by the rotation of the sealed container 12 around the rotation axis A is the pressure between the gaseous alkali metal on the upstream side of the high temperature part (inner chamber 20A) and the gaseous alkali metal on the downstream side of the hot part (outer chamber 20B). Acts to increase the difference. That is, sufficient liquid alkali metal is supplied to the upstream side of the high temperature part (inner chamber 20A) by centrifugal force, and gaseous alkali metal is collected at the interface of the BASE 30 by centrifugal force, so that the alkali metal on the downstream side of the high temperature part. The difference in pressure upstream of the high temperature portion with respect to the pressure increases. The outer chamber 20B includes a portion positioned radially outward from the inner chamber 20A. Since the alkali metal in the outer chamber 20B is a gas having a lower density than the liquid, the pressure increase due to the centrifugal force in this portion is extremely low. Even in this portion, the pressure difference on the upstream side of the high temperature portion with respect to the pressure on the downstream side of the high temperature portion of the alkali metal is increased.

  As a result, the pressure difference between the high temperature part upstream side (anode side) and the high temperature part downstream side (cathode side) on both sides of the BASE 30 increases, and the driving force (ion driving force) through which ions pass through the BASE 30 increases. Accordingly, separation of alkali metal ions and electrons on the anode side (cathode side) of the BASE 30 is promoted, and the power generation voltage per unit volume of the BASE 30 is increased without further increasing the temperature of the heat receiving part B.

  Thereby, utilization of a low-temperature heat source is attained. When the heat receiving part B is heated by using waste heat, the waste heat can be lowered, and the available waste heat sources such as exhaust gas of an internal combustion engine of an automobile are expanded.

  Further, the rotation of the sealed container 12 increases the heat receiving effect in the heat receiving part B and the heat dissipating effect in the heat radiating part C. Even if the temperature difference between the heat radiating part C and the heat receiving part B increases, The difference in pressure at the upstream side of the high temperature portion with respect to the pressure at is increased. This also has the effect of increasing the power generation voltage per unit volume of BASE30.

  Moreover, since the force which conveys an alkali metal to the high temperature part upstream of BASE30 is obtained by a centrifugal force, a wick pump or an electromagnetic pump can be omitted.

  Moreover, since the high temperature part upstream side (inner chamber 20A) is disposed radially outside the rotation axis A from the low temperature part corresponding to the heat radiating part C, that is, the inner hollow part 24A and the outer hollow part 24B, The portion (outer hollow portion 24B) where the low temperature portion communicates with the upstream side of the high temperature portion (inner chamber 20A) via the lower disk-shaped hollow portion 16B is the downstream side of the high temperature portion via the upper disk-shaped hollow portion 16A. Since it is disposed radially outward of the rotation axis A with respect to the portion (inner hollow portion 24A) communicating with (outer chamber 20B), the downstream side of the high temperature portion (outer chamber 20B) is further disposed of BASE30. Since it communicates with the low temperature part (inner hollow part 24A) radially inward of the rotational axis A from the position, the centrifugal force due to the rotation around the rotational axis A of the sealed container 12 is Of the alkali metal with the downstream side of the high temperature part Acting efficiently effectively to increase the force differential.

  Moreover, since the high temperature part (heat receiving part B) and the low temperature part (heat radiation part C) exist on one rotation axis A, even if the sealed container 12 rotates around the rotation axis A, the high temperature part and the low temperature part The position in the direction along the rotation axis A does not change, the high temperature part is always located at a fixed position where it is exposed to the high temperature fluid, and the low temperature part is always located at a fixed position where it is exposed to the high temperature fluid. Since the high temperature part is arranged vertically above the low temperature part, gravity acts on the flow of alkali metal from the high temperature part to the low temperature part, and the flow of alkali metal from the high temperature part to the low temperature part is caused. In addition to being smooth, the alkali metal can be stored in the low temperature portion in preparation for restart.

  Moreover, the converter with a high generated voltage is obtained by incorporating the several BASE30 in the one airtight container 12 to rotate.

  Further, since the central cylindrical portion 22 is arranged concentrically with the rotation axis A, and the arrangement of the plurality of outer cylindrical portions 18 on the disk portion 14 is a point-symmetric arrangement with respect to the rotation axis A, the sealed container 12 is arranged. In the rotation around the rotation axis A, there is no rotation balance imbalance due to the eccentric load.

  A second embodiment of the alkali metal thermoelectric converter according to the present invention will be described with reference to FIG. 3, parts corresponding to those in FIG. 1 are denoted by the same reference numerals as those in FIG. 1, and description thereof is omitted.

  In this embodiment, the inner peripheral surface 22B of the central cylindrical portion 22 has a tapered shape in which the inner diameter becomes smaller from the disk portion 14 side toward the protruding end (lower end) side.

  By this taper shape, an upward flow component is given to the alkali metal moved to the inner peripheral surface 22B side by centrifugal force, and the flow of the alkali metal toward the lower disk-shaped hollow portion 16B through the outer hollow portion 24B becomes smooth.

  Further, the inner peripheral surface 28A of the cylindrical inner partition wall 28 has a tapered shape in which the inner diameter increases from the disk-shaped inner partition wall 26 side toward the extended end (lower end) side.

  With this taper shape, a downward flow component is given to the alkali metal moved to the inner peripheral surface 28A side by centrifugal force, and the flow of the alkali metal descending the inner hollow portion 24A becomes smooth.

  Except for these configurations and effects, the embodiment is the same as the above-described embodiment, and the same effects as those of the above-described embodiment can be obtained.

  A third embodiment of the alkali metal thermoelectric converter according to the present invention will be described with reference to FIGS. 4 and FIG. 5, parts corresponding to those in FIG. 1 are denoted by the same reference numerals as those in FIG. 1 and description thereof is omitted.

  In this embodiment, a plurality of plate-like fins 37 projecting toward the center of the BASE 30 from the inner peripheral surface of the BASE 30, that is, the surface upstream of the high temperature portion, and extending in the axial direction (bus line direction of the BASE 30). Are integrally formed at equal intervals in the circumferential direction.

  According to the BASE 30, the fin 37 increases the surface area of the inner peripheral surface of the BASE 30, that is, the anode side upstream of the high-temperature portion, and the anode side of the BASE 30 increases as the surface area increases. The area in contact with increases.

  The alkali metal such as sodium emits electrons and enters the BASE 30. Among the alkali metals existing near the anode side surface of the BASE 30, those having a certain kinetic energy or more emit electrons and BASE 30. It is thought that it enters inside. Therefore, as the contact area between the anode side surface (inner peripheral surface) of the BASE 30 and the alkali metal is increased, the probability that an alkali metal having high kinetic energy is located near the anode side surface of the BASE 30 increases. The number of ions to increase increases. Accordingly, the amount of electrons separated on the anode side of the BASE 30 is increased, and due to this, centrifugal force generated by the rotation of the sealed container 12 causes the high temperature portion upstream side (anode side) and the high temperature portion downstream side (cathode side) of the BASE 30. By increasing the pressure difference of BASE30, the separation of alkali metal ions and electrons on the anode side of BASE30 is promoted to improve the power generation efficiency, increasing the size of BASE30 and increasing the temperature of heat receiving part B. Without generating, the power generation capacity of the AMTEC 10 increases.

  On the anode side, conduction with the negative electrode member 34 is performed using a liquid alkali metal as a conductor. Therefore, even when the inner peripheral surface of the BASE 30 is uneven by the fins 37, conduction on the anode side is achieved regardless of the shape.

  A fourth embodiment of the alkali metal thermoelectric converter according to the present invention will be described with reference to FIGS. 6 and 7, portions corresponding to those in FIGS. 1 and 2 are denoted by the same reference numerals as those in FIGS. 1 and 2, and description thereof is omitted.

  In this embodiment, the disk part 14 and the center cylindrical part 22 are comprised by the separate member. The disk portion 14 is made of synthetic resin and is integrally formed with the cylindrical inner partition wall 28. The central cylindrical portion 22 is made of metal and is integrally formed with the rotation center shaft 38.

  The outer chamber 20 </ b> B defined between the outer cylindrical portion 18 and the BASE 30 communicates with the inner hollow portion 24 </ b> A in the central cylindrical portion 22 through an inlet passage 27 formed radially in the disk portion 14 for each BASE 30. The inner chamber 20 </ b> A in the BASE 30 communicates with the outer hollow portion 24 </ b> B in the cylindrical inner partition wall 28 by an outlet passage 29 formed radially in the disk portion 14 for each BASE 30.

  In this passage structure, liquid alkali metal is supplied from the outer hollow portion 24B to the outer chamber 20B through the inlet passage 27, and alkali metal ions pass from the outer peripheral side to the inner peripheral side of the BASE 30, and exit from the inner chamber 20A. The gaseous alkali metal is returned to the inner hollow portion 24A through the passage 29.

  Thereby, the outer peripheral surface of BASE30 becomes an anode side, and the inner peripheral surface of BASE30 becomes a cathode side. Disc-shaped fins 33 are integrally formed on the outer peripheral surface of the BASE 30 so as to surround the outer periphery of the BASE 30. A plurality of fins 33 are provided at intervals in the axial direction of the BASE 30, and each protrudes outward from the outer peripheral surface of the BASE 30.

  The outer cylindrical portion 18 also serves as a cathode member, and is electrically connected to the cathode slip ring 52 by a lead wire 53. On the anode side, conduction with the outer cylindrical portion 18 forming the cathode member using the liquid alkali metal present in the outer chamber 20B as a conductor is taken, so even if the outer peripheral surface of the BASE 30 is uneven by the fins 33, Regardless of shape, conduction on the anode side is taken. In this embodiment, the outer chamber 20B is not loaded with a foam metal body, and the outer chamber 20B is a space filled with a liquid alkali metal.

  The inner peripheral surface of the BASE 30, that is, the inner peripheral surface that defines the inner chamber 20 </ b> A is a circumferential surface having the same cross-sectional shape over the entire length in the axial direction, and this inner peripheral surface has an anode layer with a thin film structure having air permeability. 35 is formed by sputtering or the like. The inner chamber 20A is filled with a connecting member 45 made of a porous (three-dimensional network structure) metal having air permeability. The connection member 45 is electrically connected to the anode layer 35 on the outer peripheral surface. A non-breathable connection terminal 39 made of a bulk metal body is attached to the disk portion 14 so as to penetrate the lower side of the outlet passage 29 into and out of the sealed container 12. One end of the connection terminal 39 is located in the inner chamber 20 </ b> A and is conductively connected to the connection member 45. The other end of the connection terminal 39 is outside the sealed container 12 and is conductively connected to the anode slip ring 60 by a lead wire 61. A seal member 41 for keeping the airtightness of the outlet passage 29 is attached to a portion where the connection terminal 39 penetrates the disk portion 14. The connection terminal 39 may be omitted, the lead wire 61 may be extended into the inner chamber 20 </ b> A, and the extended end of the lead wire 61 may be directly connected to the connection member 45.

  Further, heat receiving fins 15 are formed on the outer periphery of the outer cylindrical portion 18 that is the heat receiving portion B of the AMTEC 10, and heat radiating fins 25 are formed on the outer periphery of the central cylindrical portion 22 that is the heat radiating portion C of the AMTEC 10.

  Also in this embodiment, when the sealed container 12 is rotated around the rotation axis A by the electric motor 42, a centrifugal force is generated in the AMTEC 10. The alkali metal in the airtight container 12 is condensed from the gas into a liquid by heat radiation in the outer hollow portion 24B which is a low temperature portion corresponding to the heat radiation portion C. The liquid alkali metal, which has a higher density than the gaseous alkali metal, moves outward along the inner peripheral surface 22B of the central cylindrical portion 22 such that the liquid level rises while being pressed against the inner peripheral surface 22B of the central cylindrical portion 22 by centrifugal force. The hollow portion 24B is lifted and reaches the inlet passage 27. Then, the liquid alkali metal flows radially outward in the inlet passage 27 and is transported to the outer chamber 20B on the upstream side of the high temperature part.

  The liquid alkali metal transported to the outer chamber 20B is separated into alkali metal ions and electrons in the outer chamber 20B, and only ions move through the BASE 30. The separated electrons move from the outer cylindrical portion 18 forming the cathode member to the external load (not shown) through the cathode slip ring 52, and travel from the external load to the anode layer 35 through the anode slip ring 60. The ions that have passed through the BASE 30 recombine with electrons on the anode layer 35 in the inner chamber 20A on the downstream side of the high temperature portion, become gaseous alkali metal, and go to the inner hollow portion 24A through the outlet passage 29.

  According to this BASE 30, the fin 33 increases the surface area of the outer surface of the BASE 30, that is, the anode side upstream of the high temperature portion, as compared with the surface area on the cathode side. The area in contact with the liquid alkali metal in 20B increases.

  Thereby, also in this embodiment, since the probability that the alkali metal having high kinetic energy is located in the vicinity of the anode side surface of the BASE 30 increases, the number of ions entering the BASE 30 increases. Accordingly, the amount of electrons separated on the anode side of the BASE 30 is increased, and due to this, centrifugal force generated by the rotation of the sealed container 12 causes the high temperature portion upstream side (anode side) and the high temperature portion downstream side (cathode side) of the BASE 30. By increasing the pressure difference of BASE30, the separation of alkali metal ions and electrons on the anode side of BASE30 is promoted to improve the power generation efficiency, increasing the size of BASE30 and increasing the temperature of heat receiving part B. Without generating, the power generation capacity of the AMTEC 10 increases.

  The surface area on the anode side of BASE 30 is more than twice the surface area on the cathode side and larger than the surface area on the cathode side, which is preferable in terms of an increase in the amount of electrons separated on the anode side, that is, an increase in power generation output.

  FIG. 7 shows a usage example of the AMTEC 10 using the exhaust gas of the internal combustion engine, which is waste heat, as a heat source. The heat receiving portion B of the AMTEC 10 is disposed in the main passage 102 of the exhaust pipe 100 of the internal combustion engine so as to be able to exchange heat with the exhaust gas flowing through the main passage 102. Thereby, the heat receiving part B is heated by exhaust gas. The heating temperature of the heat receiving part B by the exhaust gas may be 500 ° C. or higher.

  The heat radiation part C of the AMTEC 10 is disposed in a bypass passage 104 parallel to the main passage 102. The exhaust gas inlet 106 of the bypass passage 104 is configured to be opened and closed by an on-off valve 108. An outside air inlet 110 is formed in the bypass passage 104, and a reed valve 112 for taking in outside air is attached to the outside air inlet 110. In this usage example, the heat receiving fin 15 is formed in the heat receiving part B of the AMTEC 10, and the heat radiating fin 25 is formed in the heat radiating part C of the AMTEC 10. Reference numerals 114 and 115 denote hermetic rotary seal portions.

  When the AMTEC 10 is started, in order to preheat the heat dissipating part C, the on-off valve 108 is opened, exhaust gas flows through the bypass passage 104, and the heat dissipating part C is heated by the exhaust gas. The preheating of the heat radiating part C is performed in order to liquefy the alkali metal that has become solid in the low temperature part. After the preheating of the heat dissipating part C is completed, the on-off valve 108 is closed, the outside air is taken into the bypass passage 104 by the reed valve 112, and the heat dissipating part C is kept at a lower temperature than the heat receiving part B. The appropriate temperature of the heat radiating part C is determined by the temperature of the heat receiving part B and may be about 100 to 500 ° C.

  Thereby, the AMTEC 10 operates using the exhaust gas of the internal combustion engine as a heat source.

  Although the present invention has been described above with reference to preferred embodiments, the present invention is not limited to the above-described embodiments and can be understood by those skilled in the art without departing from the spirit of the present invention. The range can be changed as appropriate.

  For example, in order to further increase the heat exchange efficiency with the high temperature fluid in the heat receiving portion B and the heat exchange efficiency with the low temperature fluid in the heat radiating portion C, heat receiving fins and heat radiating fins are formed on the outer peripheral portion of the sealed container 12. May be. In this case, since the heat receiving fins and the heat radiating fins rotate together with the rotation of the sealed container 12, it can be expected that the heat transfer efficiency is increased and the transfer and release of thermal energy is promoted.

  Further, it is not always necessary that the entire upstream side of the high temperature part is arranged radially outward of the rotation axis A with respect to the low temperature part, and at least a part of the upstream side of the high temperature part is radial direction of the rotation axis A with respect to the low temperature part. It only needs to be arranged outward. That is, the upstream side of the high temperature part only needs to include a portion arranged radially outward of the rotation axis A with respect to the low temperature part.

  Further, the AMTEC 10 has an upside down arrangement even when the center cylindrical part 22 is located above the disk part 14 and the outer cylindrical part 18 is located below the disk part 14. Also good.

  As shown in FIG. 8, the alkali metal thermoelectric converter according to the present invention circulates an alkali metal so as to pass through a heat receiving part B exposed to a high temperature fluid and a heat radiating part C exposed to a low temperature fluid. A closed container 70 having a defined path 72 is provided, and the circulation path 72 is divided into an upstream high temperature section upstream and a downstream high temperature section downstream in a high temperature section corresponding to the heat receiving section B of the circulation path 72. The present invention can also be applied to a basic configuration in which a β-alumina solid electrolyte member (BASE) 74 is disposed in a sealed container 70 so as to be separated.

  In this case, the rotation center shaft 76 may be attached to the sealed container 70 so that the position of the BASE 74 is positioned outside the rotation radius, and the rotation center shaft 76 may be rotated by the electric motor 78. A cathode member 80 made of a porous metal body is provided on the upstream side of the high temperature part of the BASE 74, and an anode member 82 made of a porous metal body is provided on the downstream side of the high temperature part.

  Further, the convex portion for increasing the contact area with the alkali metal on the anode side of the BASE 30 is not limited to the fins 33 and 37, but may be a bellows shape or a hemispherical projection.

  In addition, all the components shown in the above embodiment are not necessarily essential, and can be appropriately selected without departing from the gist of the present invention.

10 Alkali metal thermoelectric converter (AMTEC)
DESCRIPTION OF SYMBOLS 12 Sealed container 14 Disc part 16 Disc-shaped hollow part 16A Upper disk-shaped hollow part 16B Lower disk-shaped hollow part 18 Outer cylindrical part 20 1st cylindrical hollow part 20A Inner room 20B Outer room 22 Central cylindrical part 22B Inner peripheral surface 24 2nd cylindrical hollow part 24A inner side hollow part 24B outer side hollow part 26 disk shaped internal partition 28 cylindrical internal partition 28A inner peripheral surface 30 beta alumina solid electrolyte member (BASE)
31 Anode member 33 Fin 34 Cathode member 35 Anode layer 37 Fin

Claims (16)

A sealed container having a heat receiving portion exposed to a high temperature fluid and a heat radiating portion exposed to a low temperature fluid, and having an alkali metal circulation path defined so as to pass through the heat receiving portion and the heat radiating portion;
Β-alumina disposed in the hermetic container so as to divide the circulation path into an upstream high-temperature part upstream and a downstream high-temperature part downstream in a high-temperature part corresponding to the heat-receiving part of the circulation path A solid electrolyte member;
A cathode member disposed upstream of the high temperature part;
An alkali metal thermoelectric converter having an anode member disposed on the downstream side of the high temperature part,
Alkali metal thermoelectric conversion having a rotating device for rotating the hermetic container around a predetermined rotation axis so that a difference in pressure on the upstream side of the high temperature part with respect to pressure on the downstream side of the high temperature part of the alkali metal is increased by centrifugal force vessel.   2. The alkali metal thermoelectric converter according to claim 1, wherein the upstream side of the high temperature part includes a portion disposed radially outward of the rotation axis with respect to the low temperature part.   The part where the low temperature part communicates with the upstream side of the high temperature part is disposed radially outward of the rotation axis with respect to the part where the low temperature part communicates with the downstream side of the high temperature part. The alkali metal thermoelectric converter as described.   The alkali metal thermoelectric conversion according to any one of claims 1 to 3, wherein a downstream side of the high temperature portion communicates with the low temperature portion inward in a radial direction of the rotation axis from a position where the β alumina solid electrolyte member is disposed. vessel. The high temperature part is disposed on one side in the direction along the rotation axis of the sealed container,
The alkali metal thermoelectric converter according to any one of claims 1 to 4, wherein the low-temperature portion is disposed on the other side in the direction along the rotation axis of the sealed container.   The alkali metal thermoelectric converter according to claim 5, wherein the high temperature part is arranged vertically above the low temperature part.   The alkali metal thermoelectric converter according to any one of claims 1 to 6, wherein a convex portion is integrally formed on a surface of the β alumina solid electrolyte member on the upstream side of the high temperature portion. The sealed container is
A disk portion defining a disk-shaped hollow portion therein;
A plurality of first cylindrical hollow portions that are arranged at intervals in the circumferential direction so as to protrude in the axial direction from an outer peripheral portion of one disk surface side of the disk portion and that communicate with the disk-shaped hollow portion. The outer cylinder of the
A central cylindrical portion that projects in an axial direction from a central portion on the other disk surface side of the disk portion and defines a second cylindrical hollow portion communicating with the disk-shaped hollow portion inside;
A disk-shaped internal partition that divides the disk-shaped hollow part into a first disk-shaped hollow part and a second disk-shaped hollow part located on the one disk surface side and the other disk surface side, respectively;
Extending from the center of the disk-shaped inner partition to the vicinity of the projecting end of the center cylinder so as to divide the inside of the center cylinder in the radial direction, the first disk-shaped hollow is A cylindrical inner partition that communicates with the vicinity of the protruding end of the cylindrical hollow portion of 2,
The β-alumina solid electrolyte member protrudes from the disk-shaped inner partition into the first cylindrical hollow portion so as to divide the inside of the outer cylindrical portion in the radial direction, the tip is closed, and the second The alkali metal thermoelectric converter according to any one of claims 1 to 7, comprising a cylindrical body having an inner chamber communicating with the disc-shaped hollow portion.   The alkali metal thermoelectric converter according to claim 8, wherein the central cylinder portion is disposed concentrically with the rotation axis.   The alkali metal thermoelectric converter according to claim 8 or 9, wherein a throttle part for restricting a flow of the alkali metal is formed in a communication part between the first disk-shaped hollow part and the inside of the central cylinder part.   The said center cylinder part is comprised by the cylindrical body, The inner peripheral surface becomes a taper shape from which an internal diameter becomes small as it goes to the protrusion end side from the said disk part side, It is any one of Claim 8 to 10 characterized by the above-mentioned. Alkali metal thermoelectric converter.   The cylindrical inner partition wall is formed of a cylindrical body, and has an inner peripheral surface that has a tapered shape in which an inner diameter increases from the disk-shaped inner partition wall side toward the extending end side. The Aruri metal thermoelectric converter according to one item.   The alkali metal thermoelectric converter according to any one of claims 1 to 12, wherein the heat receiving portion is arranged to be able to exchange heat with exhaust gas of an internal combustion engine. A sealed container having a heat receiving portion exposed to a high temperature fluid and a heat radiating portion exposed to a low temperature fluid, and having an alkali metal circulation path defined so as to pass through the heat receiving portion and the heat radiating portion;
Β-alumina disposed in the hermetic container so as to divide the circulation path into an upstream high-temperature part upstream and a downstream high-temperature part downstream in a high-temperature part corresponding to the heat-receiving part of the circulation path A solid electrolyte member;
A cathode member disposed upstream of the high temperature part;
An operating method of an alkali metal thermoelectric converter having an anode member arranged on the downstream side of the high temperature part,
An operation method of applying centrifugal force to the alkali metal by rotating the hermetic container around a predetermined rotation axis so that a difference in pressure on the upstream side of the high temperature part with respect to pressure on the downstream side of the high temperature part of the alkali metal is increased. .   The method of operating an alkali metal thermoelectric converter according to claim 14, wherein the sealed container is rotated around a rotation axis located at a position away from the arrangement position of the β-alumina solid electrolyte member in the rotational radius direction.   The centrifugal force increases the pressure difference of the alkali metal between the upstream side and the downstream side of the β alumina solid electrolyte member, and promotes separation of the alkali metal ions and electrons on the cathode side of the β alumina solid electrolyte member. The method of operating an alkali metal thermoelectric converter according to claim 14 or 15, wherein the magnitude of the centrifugal force is set as follows.

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