DE102016204738A1 - Heater head for a hot gas engine - Google Patents

Abstract

The present invention relates to a heater head (6) for an alpha type hot gas engine having a plurality of double acting cylinders in Siemens arrangement. The heater head (6) comprises a plurality of heating tubes (14) in an annular array (20) about a central axis (18) each connecting an expansion space (12) of such a cylinder to a regenerator (10). The regenerators (10) are distributed in the circumferential direction (16) along an outer track (19), while the expansion spaces (12) in the circumferential direction (16) are arranged distributed along an inner track (19). The inner web (17) and the outer web (19) are arranged coaxially to the central axis (18). The inner web (17) is arranged radially inside the outer web (19). An improved efficiency results when the heating tubes (14) in the annular assembly (20) are arranged so that each heating tube (14) from the respective expansion space (12) to the respective regenerator (10) in the circumferential direction (16) over more extends as 180 °.

Description

The present invention relates to a heater head for an alpha type hot gas machine having the features of the preamble of claim 1. The invention also relates to a hot gas engine equipped with such a heater head and to a solar system having at least one such hot gas engine.

A hot gas engine is usually a sterling machine or a Vuilleumier machine. In such a hot gas engine, a regenerator is connected on the one hand to an expansion space and on the other hand to a compression space. In an alpha type hot gas engine, the expansion space and the compression space, which are connected to each other via the regenerator, are arranged in different cylinders, which are accordingly single-acting cylinders. In a double-acting cylinder, a piston which is adjustably arranged in the cylinder in an adjustable manner separates within the cylinder an expansion space from a compression space. In the case of a Siemens arrangement of double-acting cylinders, the associated expansion space in each cylinder is connected via such a regenerator to a compression space of another cylinder, while the associated compression space is connected to the expansion space of another cylinder via a further regenerator.

A hot gas engine of the alpha type with several double-acting cylinders in Siemens arrangement is, for example, from the DE 199 28 202 A1 known.

Within the hot gas machine, a working medium, usually a gas, is pumped back and forth between an expansion space and a compression space. In this case, the respective regenerator is fluidically coupled to the respective expansion space via at least one heating tube and to the respective compression space via at least one cooling tube. Heat can be supplied to the hot gas engine via the heating pipes to effect the expansion of the working medium. If the hot gas engine has a plurality of cylinders, the associated heating pipes are expediently combined to form a unit in a heater head.

A generic heater head is, for example, from the DE 26 31 306 C2 known. Such a heater head has a plurality of heating tubes in an annular arrangement about a central axis. These heating pipes each connect an expansion space of a cylinder with a regenerator. In this case, the regenerators or the regenerators associated ends of the heating tubes are distributed in the circumferential direction along an inner track in the heater head, while the expansion spaces or the expansion spaces associated ends of the heating tubes are arranged distributed in the circumferential direction along an outer track. The inner web and the outer web are arranged coaxially to the central axis. In addition, the inner web is arranged radially within the outer web. In other words, in the hot gas engine, the regenerators are arranged radially further inward than the cylinders with the expansion spaces. For the heater head this means that the heating tube ends assigned to the regenerators are arranged radially further inwards than the heating tube ends assigned to the expansion spaces.

In the known heater head is ever a pair of regenerator and expansion space, which are interconnected via at least one such heating tube, adjacent to each other in the circumferential direction over less than 90 °. Furthermore, in the known heater head, the heating tubes are arranged in the annular arrangement so that each heating tube extends from the respective regenerator to the respective expansion space in the circumferential direction over less than 90 °, namely approximately the same angular range in which the associated regenerator and the associated Expansion space in the circumferential direction are spaced apart. In the known heater head thus the heating pipes are laid on the shortest path between the regenerator and expansion chamber to achieve the lowest possible volume of working fluid within the heating pipes. The volume of working fluid contained in the heating tubes represents a passive volume that reduces the efficiency of the hot gas engine.

In order to be able to realize the highest possible heat output, each pair of regenerator and expansion space is advantageously connected to one another via a plurality of such heating pipes, which run parallel to one another within the arrangement. In order to accommodate as many such, mutually parallel heating pipes within the arrangement, this may be configured conical or frusto-conical. This gives the heater head an axial height, which is the greater, the more heating tubes are used.

The present invention is concerned with the problem of providing an improved embodiment for a generic heater head or for a hot gas engine equipped therewith or for a solar system equipped therewith, which is characterized in particular by an increased energy efficiency and / or by a reduced axial height.

This problem is inventively achieved by the subject matter of the independent claim solved. Advantageous embodiments are the subject of the dependent claims.

The invention is based on the general idea of extending the heating tubes within the annular arrangement. For this purpose, the invention proposes to arrange the heating tubes in the annular arrangement so that each heating tube extends from the respective regenerator to the respective expansion space in the circumferential direction over more than 180 °. The circumferential direction in the present context refers to the center axis of the heater head, i. the circumferential direction rotates about the central axis. The central axis is defined by the arrangement of the heating tubes of the heater head, which extends annularly with respect to the central axis. The central axis also defines an axial direction which is parallel to the central axis, while a radial direction extends transversely to the central axis.

Due to the longer heating pipes, the area in which a heat supply is possible, increased, so that the working fluid along the heating pipes can absorb more heat energy. Although the respective heating tube by its greater length contains a larger passive volume of working medium, the overall efficiency of the hot gas engine can be increased due to the proposed design. This is due, on the one hand, to the fact that the ratio of useful volume to dead volume can be increased in the passive volume. The useful volume is in the heated areas of the heating tubes, while the dead volume is in the connection areas of the heating tubes, which connect the heated areas with the expansion spaces and the regenerators. Due to the longer heating tubes decreases their number. For example, in the case of the heating tubes extended according to the invention, the number of heating tubes per pair of expansion space and regenerator can be halved. Now, if fewer heating tubes per pair of regenerator and expansion space are required to effect the desired heating of the working medium, the dead volume decreases as the useful volume increases. On the other hand can be achieved by the extended heating tubes or by the larger useful volume, a higher temperature in the working fluid, which increases the energy efficiency of the hot gas engine. Furthermore, it has been shown that despite the longer heating tubes due to the reduced number of heating tubes per pair of regenerator and expansion space, the axial height of the annular arrangement can be reduced. Furthermore, it has also been shown that with a reduced number of heating pipes optimized laying of the heating tubes within the annular arrangement can be realized, for example, to realize minimum gap distances between adjacent in the circumferential direction heating pipes. In particular, adjacent heating pipes, which are associated with the same pair of regenerator and expansion space, also touch.

The abovementioned numerical reduction of the required heating pipes also results in a corresponding reduction of the required solder joints at the connection points to the expansion spaces and the regenerators, which simplifies the production and makes it less expensive. The longer heating tubes are bend softer than short heating tubes, so that the heating tube assembly is less stiff.

Furthermore, the invention proposes that the regenerators are distributed in the circumferential direction along an outer track, while the expansion spaces are arranged distributed in the circumferential direction along an inner track. The inner web and the outer web are expediently arranged coaxially to the central axis, wherein the inner web is arranged radially within the outer web. The arrangement of the cylinders with the expansion spaces on the inner track has energetic advantages, because they are close together and the heat can be concentrated. In contrast, the external regenerators are further apart, which facilitates the dissipation of heat. Thus, this particular arrangement already leads to an improvement in the energy efficiency of the heater head or the hot gas machine equipped therewith.

According to an advantageous embodiment, the respective heating tube may extend from the associated expansion space to the associated regenerator in the circumferential direction in an angular range of 225 ° to 315 °. Preferably, the respective heating tube may extend from the associated expansion space to the associated regenerator in the circumferential direction over approximately 270 °. The latter applies in particular to a heater head intended for a four-cylinder hot gas engine.

Suitably, a pair of regenerator and expansion space, which are connected to each other via at least one such heating tube, be adjacent to each other in the circumferential direction over less than 180 °. The distance measured in the circumferential direction is in each case the smaller angle that the regenerator and the expansion space of the same pair have with each other. Suitably, regenerator and expansion space of the same pair may be adjacent to each other in the circumferential direction in an angular range of 45 ° to 135 °. It is preferably provided that the regenerator and expansion space of the same pairing are adjacent to one another in the circumferential direction over approximately 90 °. The latter is especially the case when the heater head is provided for a four-cylinder hot gas engine.

Particularly expedient is an embodiment in which, within a pairing of regenerator and expansion space, which are connected to each other via at least one such heating tube, regenerator and expansion space in the circumferential direction are arranged offset from one another such that a first direction of rotation, e.g. in the counterclockwise direction, from the expansion space to the regenerator, while the respective heating tube connecting the regenerator and the expansion space of this pairing extends from the expansion space to the regenerator in a second direction of rotation, e.g. clockwise, which is opposite to the first direction of rotation. The distance between regenerator and expansion space, measured in the circumferential direction, and the direction of extension of the respective heating tubes in total complement one another in a 360 ° fashion.

Preferably, the annular arrangement is designed to be concave on a side remote from the regenerators and the expansion spaces. This improves the usability of the heater head in a solar system using e.g. by means of a parabolic mirror of the annular array of sunbeams, preferably concentrated, are supplied. For example, the annular arrangement may be frusto-conical or spherical, ie spherical shell-shaped, or parabolically shaped.

According to another advantageous embodiment, each heating tube may have an inner connecting portion, an outer connecting portion and a heating portion, wherein the respective heating portion is connected via the inner connecting portion with the respective expansion space and via the outer connecting portion with the respective regenerator. Furthermore, the respective heating section is located in the annular arrangement, while the connecting sections lead substantially axially to the arrangement or substantially axially away from the arrangement. By this design, the heating sections can be arranged particularly favorable in the annular arrangement in order to achieve the highest possible heat utilization.

Particularly advantageous is an embodiment in which the heating pipes connect exactly four regenerators with the expansion spaces of exactly four cylinders. In this case, the heater head is provided for a four-cylinder hot gas engine.

Furthermore, an embodiment is advantageous in which the annular arrangement of the heating tubes is designed as a solar receiver. Such a solar receiver receives within a solar system solar radiation, useful in concentrated or bundled form.

A hot gas engine according to the invention of the alpha type is characterized by a plurality of cylinders in Siemens arrangement and has a plurality of regenerators, namely suitably one regenerator per cylinder. Further, a heater head of the type described above is provided. In each cylinder, a piston is arranged adjustable in stroke, which separates an expansion space of a compression space in each cylinder. Each regenerator is connected on the one hand via at least one heating tube to the expansion space of such a cylinder and on the other hand connected via at least one cooling tube with the compression space of another such cylinder.

A solar system according to the invention is equipped with at least one parabolic mirror for concentrating solar radiation on a solar receiver. Furthermore, the solar system is equipped with at least one hot gas machine having a heater head of the type described above. The parabolic mirror concentrates the sun's rays on the annular arrangement of the heating pipes, which thus serves as a solar receiver.

Other important features and advantages of the invention will become apparent from the dependent claims, from the drawings and from the associated figure description with reference to the drawings.

It is understood that the features mentioned above and those yet to be explained below can be used not only in the particular combination given, but also in other combinations or in isolation, without departing from the scope of the present invention.

Preferred embodiments of the invention are illustrated in the drawings and will be described in more detail in the following description, wherein like reference numerals refer to the same or similar or functionally identical components.

Show, in each case schematically,

1 a simplified schematic diagram of a solar system,

2 a simplified, isometric schematic representation of a hot gas machine,

3 a schematic plan view of a heater head in omitted heating tubes,

4 a top view of a heater head with heating pipes,

5 an isometric view of the heater head 4 ,

Corresponding 1 includes a solar system 1 at least one parabolic mirror 2 , with whose help sunbeams 3 on a solar receiver 4 can be concentrated. The solar system 1 is also with at least one hot gas engine 5 equipped with the help of which the solar energy or the solar radiation energy can be converted into electrical energy. For this purpose, the hot gas machine 5 on the one hand a heater head 6 and on the other hand, a generator 7 on. At the heater head 6 is the solar receiver 4 educated. Inside the hot gas engine 5 The heat energy is transferred through the heater head 6 is fed, converted into mechanical work, with the help of the generator 7 can be converted into electricity. The electric current is here, for example, via a cable 8th dissipated. The solar system 1 may also have suitable means for tracking the parabolic mirror 2 be fitted to the orientation of the parabolic mirror 2 to track the sun according to the course of the sun.

The hot gas engine 5 is according to 2 suitably of the alpha type and has several double-acting cylinders 9 in Siemens arrangement. Every cylinder 9 is a regenerator 10 assigned. In the shown, preferred example is the hot gas engine 5 designed as a four-cylinder engine, so that accordingly four cylinders 9 and four regenerators 10 available. The hot gas engine 5 is preferably designed as a sterling machine or as a sterling motor.

Every cylinder 9 contains a displacer or piston 11 that is inside the respective cylinder 9 each an expansion space 12 from a compression room 13 separates. In 2 are the expansion spaces 12 each overhead, while the compression rooms 13 each are arranged below lying. The pistons 11 are over connecting rods 26 coupled with an output device, not shown here, in which the bidirectional strokes of the piston 11 be converted into a continuous rotational movement of an output shaft of the output device. This output shaft drives the generator 7 at.

The regenerators 10 are each about a heating pipe 14 with an expansion area 12 connected. Furthermore, the respective regenerator 10 over a cooling tube 15 with a compression space 13 connected. According to the Siemens arrangement is the respective regenerator 10 over the heating tube 14 and the cooling tube 15 with an expansion area 12 and a compression room 13 of different cylinders 9 connected.

About the heating pipes 14 the heat supply to the hot gas machine takes place 5 , These are the heating pipes 14 combined into one unit, the heater head 6 forms. Furthermore, for the realization of such a heater head 6 the regenerators 10 according to 3 in the circumferential direction, in the 3 to 5 indicated by a double arrow and with 16 is designated, along an outer track 19 arranged coaxially with a central axis 18 which runs in the 3 and 4 extends perpendicular to the plane of the drawing. The expansion spaces 12 or the cylinders 9 are in the circumferential direction 16 along an inner track 17 arranged, which are also coaxial with the central axis 18 is arranged and located radially inside the outer track 19 located. The central axis 18 defines an axial direction to which the radial direction is perpendicular. The circumferential direction 16 rotates around the central axis 18 ,

Through the Siemens arrangement of double-acting cylinders 9 there are pairings a to d, where each pairing a to d is a regenerator 10 and an expansion area 12 includes. In 3 are the expansion spaces 12 and the regenerators 10 , which are assigned to the same pairing a to d, additionally marked with the corresponding letters a to d of the respective pairing. Recognizable is within the respective pairing a to d in the circumferential direction 16 measured distance between associated expansion space 12 and associated regenerator 10 in the example shown about 90 °. For such a pair a from regenerator 10a and expansion chamber 12a is in 4 the distance plotted and labeled A. Because the arrangement of regenerators 10 and cylinders 9 in the circumferential direction 16 symmetrically, the other pairings b to d have the same distances A between the expansion chamber 12 and regenerator 10 ,

According to the 4 and 5 form the heating pipes 14 an annular arrangement 20 around the central axis 18 , Furthermore, the heating pipes 14 within the annular arrangement 20 arranged so that each heating tube 14 from the respective expansion area 12 to the respective regenerator 10 in the circumferential direction 16 extends over more than 180 °. In the example of 4 and 5 extends the respective heating tube 14 over at least 270 °. This extension in the circumferential direction 16 is in 4 indicated by a double arrow and denoted by E. Starting from the respective expansion area 12 is the associated regenerator 10 in the circumferential direction 16 in a first direction of rotation 21 neighboring, the in 4 oriented counterclockwise. Starting from the respective expansion area 12 extend the heating pipes 14 towards the associated regenerator 10 in contrast in a second direction of rotation 22 , the first direction of rotation 21 is opposite. Thus, the second direction of rotation 22 in 4 oriented in a clockwise direction. Furthermore extend the heating pipes 14 spiraling to the expansion space 12 that is on the inside track 17 located, with the respective regenerator 10 to connect, located on the outer track 19 located.

How in particular the isometric view of the 5 can be seen, is the annular arrangement 20 the heating pipes 14 at one of the regenerators 10 and from the expansion spaces 12 opposite side, in 5 facing the viewer, concave. Furthermore, the annular arrangement 20 designed here essentially frusto-conical. Alternatively, the arrangement could 20 be designed also spherical or parabolic.

How, in particular 5 can be removed, owns each heating tube 14 an inner connecting portion 23 , an outer connecting portion 24 and one between inner connecting portion 23 and outer connection section 24 lying heating section 25 , The respective heating section 25 is over the inner connecting section 23 with the respective expansion space 12 connected. Furthermore, the respective heating section 25 over the outer connecting section 24 with the respective regenerator 10 connected. In addition, the heating sections are 25 within the annular arrangement 20 , In contrast to this are the connecting sections 23 . 24 axially outside of this annular arrangement 20 or stand thereof largely in the axial direction.

The annular arrangement 20 the heating pipes 14 forms the solar receiver 4 the hot gas engine 5 or the solar system 1 , Because the heating pipes 14 within the arrangement 20 in the circumferential direction 16 take the longer way to the expansion area 12 with the regenerator 10 to connect, own the heating pipes 14 especially in the heating section 25 a particularly long length. As a result, the working medium guided therein is also intensively exposed to the heat supply, in particular by the solar radiation. This leads to an efficient heating of the working medium. Overall, this allows the energy efficiency of the hot gas engine 5 increase. Furthermore, it has been shown that the number of required heating pipes 14 can be reduced, yet the desired heat supply to the expansion spaces 12 to obtain. This increases the ratio of useful volume to dead volume and also allows an axially compact design for the heater head 6 , what its integration into the hot gas engine 5 and their integration into the solar system 1 simplified. In addition, it has been shown that the longer and in terms of their number reduced heating pipes 14 can be packed radially dense, whereby within the annular arrangement 20 the utilization of the supplied heat is improved.

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• DE 19928202 A1 [0003]
• DE 2631306 C2 [0005]

Claims (14)

Heater head for a hot gas engine ( 5 ) of the alpha type, which has several double-acting cylinders ( 9 ) in Siemens arrangement, - with several heating pipes ( 14 ) in an annular arrangement ( 20 ) about a central axis ( 18 ), each with an expansion space ( 12 ) of such a cylinder ( 9 ) with a regenerator ( 10 ), characterized in that - the regenerators ( 10 ) in the circumferential direction ( 16 ) along an outer track ( 19 ), while the expansion areas ( 12 ) in the circumferential direction ( 16 ) along an inner track ( 17 ) are arranged, - that the inner web ( 17 ) and the outer track ( 19 ) coaxial with the central axis ( 18 ) are arranged, - that the inner web ( 17 ) radially inside the outer track ( 19 ), - that the heating pipes ( 14 ) in the annular arrangement ( 20 ) are arranged so that each heating tube ( 14 ) of the respective expansion area ( 12 ) to the respective regenerator ( 10 ) in the circumferential direction ( 16 ) extends over more than 180 °. Heater head according to claim 1, characterized in that the respective heating tube ( 14 ) from the associated expansion space ( 12 ) to the associated regenerator ( 10 ) in the circumferential direction ( 16 ) extends in an angular range of 225 ° to 315 °. Heater head according to claim 1 or 2, characterized in that the respective heating tube ( 14 ) from the associated expansion space ( 12 ) to the associated regenerator ( 10 ) in the circumferential direction ( 16 ) extends over about 270 °. Heater head according to one of claims 1 to 3, characterized in that a regenerator ( 10 ) and an expansion area ( 12 ), which via at least one such heating tube ( 14 ) are interconnected in the circumferential direction ( 16 ) are adjacent to each other over less than 180 °. Heater head according to claim 2 or 3, characterized in that a regenerator ( 10 ) and an expansion area ( 12 ), which via at least one such heating tube ( 14 ) are interconnected in the circumferential direction ( 16 ) are adjacent to each other in an angular range of 45 ° to 135 °. Heater head according to claim 3, characterized in that a regenerator ( 10 ) and an expansion area ( 12 ), which via at least one such heating tube ( 14 ) are interconnected in the circumferential direction ( 16 ) are adjacent to each other over about 90 °. Heater head according to one of claims 1 to 6, characterized in that in a pairing (a to d) of regenerator ( 10 ) and expansion space ( 12 ), which via at least one such heating tube ( 14 ), Regenerator ( 10 ) and expansion space ( 12 ) in the circumferential direction ( 16 ) are arranged offset to one another such that a first direction of rotation ( 21 ) from the expansion area ( 12 ) to the regenerator ( 10 ), while the respective heating tube ( 14 ), the regenerator ( 10 ) and the expansion area ( 12 ) of this pairing (a to d), from the expansion space ( 12 ) to the regenerator ( 10 ) in a second direction of rotation ( 22 ) extending the first direction of rotation ( 21 ) is opposite. Heater head according to one of claims 1 to 7, characterized in that the annular arrangement ( 20 ) on one of the regenerators ( 10 ) and the expansion areas ( 12 ) facing away from concave side. Heater head according to one of claims 1 to 8, characterized in that the annular arrangement ( 20 ) is truncated or spherically or parabolically shaped. Heater head according to one of claims 1 to 9, characterized in that each heating tube ( 14 ) an inner connecting portion ( 23 ), an outer connecting portion ( 24 ) and a heating section ( 25 ), wherein the heating section ( 25 ) in the annular arrangement ( 20 ) and via the inner connecting section ( 23 ) with the respective expansion space ( 12 ) while being connected via the outer connecting section ( 24 ) with the respective regenerator ( 10 ) connected is. Heater head according to one of claims 1 to 10, characterized in that the heating pipes ( 14 ) exactly four regenerators ( 10 ) with the expansion spaces ( 12 ) of exactly four cylinders ( 9 ) connect. Heater head according to one of claims 1 to 11, characterized in that the annular arrangement ( 20 ) of the heating pipes ( 14 ) as a solar receiver ( 4 ) is configured. Hot gas engine of the Alpha type, - with several cylinders ( 9 ) in Siemens arrangement, - with several regenerators ( 10 ), - with a heater head ( 6 ) according to one of the preceding claims, - in each cylinder ( 9 ) a piston ( 11 ) is arranged adjustable in stroke, in the respective cylinder ( 9 ) such an expansion space ( 12 ) from a compression space ( 13 ), wherein - the respective regenerator ( 10 ) on the one hand via at least one such heating tube ( 14 ) with the expansion space ( 12 ) of such a cylinder ( 9 ) and on the other hand via at least one Cooling tube ( 15 ) with the compression space ( 13 ) of another such cylinder ( 9 ) connected is. Solar system, - with at least one parabolic mirror ( 2 ) for concentrating sun rays ( 3 ) on a solar receiver ( 4 ), - with at least one hot gas engine ( 5 ), which has a heater head ( 6 ) according to one of claims 1 to 11, - wherein the parabolic mirror ( 2 ) the sunrays ( 3 ) on the as a solar receiver ( 4 ) annular arrangement ( 20 ) of the heating pipes ( 14 ).

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