WO2011128284A1

WO2011128284A1 - Rotary leadthrough for hot steam

Info

Publication number: WO2011128284A1
Application number: PCT/EP2011/055598
Authority: WO
Inventors: Uwe Kark
Original assignee: Kark Ag
Priority date: 2010-04-12
Filing date: 2011-04-11
Publication date: 2011-10-20
Also published as: DE202010004847U1

Abstract

The invention relates to a rotary leadthrough (1) for hot steam, in particular for use in solar-thermal installations (100). The invention also relates to a system (100) of a solar-thermal installation, comprising a thermal solar collector and a rotary leadthrough according to the invention. The rotary leadthrough (1) according to the invention for heat carrier fluid in the liquid or gaseous state comprises a shaft (10) with a hollow bore (13), and a pressure distributor space (14) which surrounds the shaft (10) in an annular manner and is bounded in the axial direction by at least one spring collar (15) which is firmly connected to the shaft (10). A connecting bore (16) through the wall of the hollow bore (13) is arranged in the region of the pressure distributor space (14). In addition, at least one sealing and bearing bushing (30) is provided, wherein each sealing and bearing bushing (30) is prestressed so as to rest flush against that face of the respectively adjacent spring collar (15) which is averted from the pressure distributor space (14).

Description

The invention relates to a rotary feedthrough for superheated steam, in particular for use in solar thermal systems. The invention further relates to a system of a solar thermal system, comprising a solar thermal collector and a rotary feedthrough.

In thermal solar collectors, the incident solar radiation is focused by means of an optical element, for example a Fresnel lens, onto an absorber through which heat transfer fluid flows. By incident solar radiation, the heat transfer fluid in

Absorber heated. The energy stored in the form of heat in the heat transfer fluid can then be fed via pipelines connected to the solar collector devices, eg. Heat exchangers, and made usable there.

It is also known that the heat transfer fluid in the absorber is heated so much that it participates in a phase transition towards the gaseous form. The gaseous heat transfer fluid can then be used to drive a turbine, where it cools again, goes into a liquid state and the absorber can be fed again.

In order to achieve the highest possible efficiency in a solar thermal collector, it is necessary that the thermal solar collector of the sun is tracked. The optical element should always perpendicular to the be aligned with incident solar radiation. It is known to mount the solar collector for this purpose pivotable about at least one axis, so that the optical element can be tracked to the position of the sun.

The absorber usually firmly connected to the optical element. Therefore, the position of the absorber changes in the above-described tracking of the solar collector. Depending on whether a one- or two-axis tracking of the solar collector takes place, the absorber is pivoted about one or two axes. Nevertheless, the supply and discharge of heat transfer fluid - and thus the flow through the absorber - must be ensured. The invention has for its object to provide a device which allows the supply and discharge of heat transfer fluid in the liquid or gaseous state along a pivot axis of a solar thermal collector.

The object is achieved by a device according to the main claim, as well as by a system according to the independent claim. Advantageous embodiments will be apparent from the dependent claims.

Accordingly, the invention relates to a rotary feedthrough for heat transfer fluid in the liquid or gaseous state for use in solar thermal systems comprising a shaft with a hollow bore, a pressure-distribution space annularly surrounding the shaft, which is bounded in the axial direction by at least one spring collar fixedly connected to the shaft, and with a arranged in the region of the pressure distribution chamber connecting bore through the wall of the Hollow bore, as well as at least one sealing and bearing bush, wherein each of the sealing and bearing bushes is flush against the side facing away from the pressure distribution chamber side of their respective adjacent spring collar and biased against it.

The invention further relates to a system comprising a thermal solar collector mounted pivotably about at least one pivot axis with an optical element and an absorber, which is designed to flow through with heat transfer fluid, and at least one rotary union with a shaft having a hollow bore, a pressure distribution chamber surrounding the shaft which is bounded in the axial direction by at least one spring collar fixedly connected to the shaft, and with a connection bore arranged in the region of the pressure distribution chamber through the wall of the hollow bore, and at least one sealing and bearing bush, each sealing and bearing bush being flush the side facing away from the pressure distribution chamber side of the respective adjacent Federbundes and biased against it, wherein the shaft of the at least one rotary feedthrough is arranged coaxially with one of the at least one pivot axis and the absorber of the thermal solar collector rotates firmly and fluidly connected to the hollow bore or the pressure distribution chamber.

In the rotary feedthrough according to the invention, heat transfer fluid can be introduced into the pressure distribution chamber. The pressure distribution chamber is arranged in a ring around the shaft and limited by at least one, with the shaft fixed and pressure-tight connected spring collar. It is preferred if the pressure chamber is delimited by two (spaced apart) spring collars, so that the pressure distribution chamber between see the two spring struts lies. Furthermore, pressure and bearing bushings are provided according to the number of spring collars. The shaft can be rotatably or slidably mounted in the or the sealing and bearing bushes. Depending on a sealing and bearing bush is sealed to the of

Pressure distributor space facing away from the respective adjacent spring collar and is biased against this. This ensures that heat transfer fluid from the pressure distribution chamber can not pass between a spring collar and the adjacent sealing and bearing bushing.

From the pressure distribution chamber, the heat transfer fluid passes through the connecting hole in the hollow bore of the shaft. The hollow bore is preferably designed as an axial blind hole. The hollow bore then has only one opening at one end of the shaft. The connection bore is designed as a through hole through the wall of the hollow bore, so that pressure distribution chamber and hollow bore are fluid-conductively connected to each other. The heat carrier fluid can flow away through the at least one opening of the hollow bore. If the hollow bore is designed as an axial blind hole, then the heat transfer fluid can flow through the opening at one end of the shaft. If the hollow bore is designed as an axial through hole, then the heat transfer fluid can flow out through the openings at the respective ends of the shaft.

Since the shaft-and thus also the at least one opening of the hollow bore-is rotatable relative to the pressure and bearing bushes and the pressure distribution chamber, a rotary feedthrough for a heat transfer fluid is achieved. A fixed against the pressure distribution chamber and with this connected component can be pivoted relative to a component connected to the shaft without a

Fluid flow would be interrupted by the rotary feedthrough according to the invention.

The rotary feedthrough according to the invention can also be flowed through in the reverse direction. The fluid then flows in the opposite direction, namely from the at least one opening of the hollow bore through the connection bore in the pressure distribution chamber.

In the case of thermal solar collectors, it is possible, in particular, for the absorber to be fixed in a rotationally fixed manner to the shaft and to be connected in a fluid-conducting manner to at least one opening of the hollow bore. The solar collector can then rotate around the axis of the shaft

Rotary feedthrough and be pivoted relative to the pressure distribution chamber, without the inflow or outflow of heat transfer medium fluid to or from the absorber would be interrupted. But it is of course also possible that the absorber is secured against rotation relative to the pressure distribution chamber and the pivoting movement relative to the shaft of the rotary feedthrough or an associated component takes place. It is preferred if the sealing and bearing bushes are held in a housing which has an opening for the passage of the shaft and an inlet and outlet opening, wherein the inlet and outlet opening opens into the pressure distribution chamber. In embodiments with more than one spring collar of the pressure distribution chamber is between the spring struts of the shaft. Heat transfer fluid can be introduced into or out of the pressure distribution chamber via the inlet and outlet opening in the housing. Since the sealing and bearing bushes are held in the housing and the shaft opposite the

Sealing and bearing bushes is rotatable, the shaft is also rotatably mounted relative to the housing. The pressure distribution chamber and the sealing and bearing bushes are sealed relative to the housing, so that fluid can flow out of the pressure distribution chamber only through the inlet and outlet openings in the housing or the connecting bore of the shaft or can flow into the pressure distribution chamber. To ensure this seal, but also to achieve the above-described bias of the sealing and bearing bushings, a circumferential spring lip may be provided on the housing. The spring lip abuts in the assembled state of the device to a sealing and bearing bush and exerts a biasing force on a sealing and bearing bush in the direction of the adjacent spring collar due to elastic deformation. Since the spring lip is circumferential, the system is also pressure-tight on a sealing and bearing bush. Between a sealing and bearing bush and the adjacent spring lip so a fluid passage is not possible.

It is preferred if the region of at least one sealing and bearing bush, which rests flush against one of the spring collars, is of spherical design. Due to the crowned design, a small sealing surface is achieved at the same time high surface pressure between the sealing and bearing bush and spring collar. Even with a slight misalignment of the shaft relative to one of the sealing and bearing bushings, a good sealing effect is achieved due to this crowned configuration.

Due to the small respective sealing surface between

Sealing and bearing bushings and spring collars, the breakaway torque in the rotary feedthrough according to the invention is very ring. The term "breakaway torque" denotes the moment required to overcome the static friction between the sealing and bearing bushes and the spring struts or the shaft A small breakaway torque, as achieved with the rotary feedthrough according to the invention, is particularly advantageous for use in Solarthermischen plants, since the rotation speed around the pivot axis of the solar collectors is very small.The sealing and bearing bushes can be used in one piece as

Flange be executed. But it is also possible that they are made in two parts, each with a collar and a socket part. The latter offers the advantage of easier manufacture of the sealing and bearing bushes. However, this can increase the assembly costs of the rotary feedthrough.

The spring collars are firmly connected to the shaft disc springs. The connection of the spring struts to the shaft is designed pressure-tight. "Pressure-tight" in the sense of this invention means that a fluid passage between two pressure-tight interconnected elements is not possible.The spring struts can be made in one piece with the shaft, but it is also possible that they are subsequently attached to the shaft, for example by welding.

Throughout the working range of the rotary feedthrough according to the invention, it should be ensured that the spring collars are always in the elastic range of their material. Only in this way can a sufficiently high sealing effect be achieved permanently. The spring collars are therefore preferably made of corrosion-resistant spring steel. Further preferred it, if the shaft is made of corrosion resistant spring steel. It is further preferred if at least one sealing and bearing bush or at least the collar part of a two-part sealing and bearing bush made of graphite. Graphite is characterized by good self-lubrication properties and heat tolerance.

An appropriate choice of material ensures that the rotary union according to the invention is suitable for high temperatures of more than 450 ° C. and high pressures of up to 150 bar. Corresponding fields of application are required, in particular, in solar thermal systems in which heat transfer fluid is brought from the liquid to the gaseous state with the aid of solar radiation.

In order to allow a simple assembly of the rotary feedthrough according to the invention, it is preferred if the housing is designed in two parts, wherein the two parts are preferably sealed against each other by a pinch seal made of copper. It is further preferred if the pressure distribution chamber is arranged in one of the two housing parts. This prevents the parting line between the two housing parts from passing through the pressure distribution chamber and forming a possible leak on the pressure distribution chamber.

The at least one opening of the hollow bore can be designed as a sealing cone, so that a further component, for example. An absorber or a conduit, pressure-tight manner can be connected to the rotary feedthrough according to the invention. It is further preferred that a threaded or clamping ring is provided at the end of the shaft on which the blind hole is arranged. Alternatively, it is possible that at the end of de the shaft on which the blind hole is arranged, a part of a cutting ring connection is formed.

In order to reduce load peaks at the connection points of the rotary leadthrough with further components, torque supports can be provided in a rotationally fixed manner relative to the distributor chamber and / or rotationally fixed relative to the shaft. About such a torque support loads on the connection areas between rotary feedthrough and other components can be reduced.

The system according to the invention comprises a thermal solar collector with an optical element and an absorber. Using the optical element, incident solar radiation can be focused on the absorber. The absorber is designed so that it can be flowed through by heat transfer fluid.

The thermal solar collector is pivotally mounted about at least one pivot axis. By the thermal solar collector is pivotally mounted, the optical element can be aligned so that it is as perpendicular to the incident solar radiation as possible. If only one pivot axis is provided, it is possible to track the solar collector according to the time of day of the sun. If the solar collector can also be pivoted about a second pivot axis, a compensation of the seasonal solar movement is also possible. The absorber can be designed as an elongated absorber tube. The optical element may be a linear Fresnel lens which focuses the incident solar radiation onto the absorber tube. A linear one Fresnel lens does not focus the incident solar radiation on one point but along a focus line. The absorber tube is then arranged along this focal line. The system according to the invention further comprises a rotary feedthrough according to the invention. To explain the rotary feedthrough reference is made to the above statements. In the system according to the invention, the absorber pipe is connected to the rotary feedthrough, either rotationally fixed and fluid-conducting with the hollow bore or with the pressure distribution chamber. The shaft of the rotary feedthrough is arranged coaxially with one of the at least one pivot axis.

Due to the rotary feedthrough, it is possible that heat transfer fluid is supplied to the absorber of the solar collector or can run off, regardless of the position around the at least one pivot axis of the thermal solar collector. The heat transfer fluid can, for example, pass from the pressure distribution chamber via the connection bore and the hollow bore into one end of the absorber tube. If a further rotary feedthrough is provided at the opposite end of the absorber tube, the heat transfer fluid can flow away via this additional rotary feedthrough. The thermal solar collector is thus pivotable about the pivot axis, without the supply or the outflow of heat transfer fluid would be interrupted. By an additional device stored in the heated, discharged from the absorber tube heat transfer fluid stored energy can be converted into usable energy. This additional device may be a heat exchanger or to be a turbine. The cooled in the additional device heat transfer fluid can then be supplied to the absorber again. It is preferred if two rotary unions are provided per pivot axis. The supply of heat transfer fluid can then be ensured via a rotary feedthrough, while the heat transfer fluid is discharged from the absorber via the other rotary feedthrough.

In addition to the function of liquid supply, the rotary unions can also fulfill the function of supporting the solar thermal collector around a pivot axis. Separate bearings are then no longer required.

If the tracking of the solar thermal collector about two axes, then rotary feedthroughs may be provided on the second pivot axis. The invention will now be further described by way of exemplary embodiments with reference to the accompanying drawings. Show it:

Fig. 1 shows a first embodiment of an inventive

Rotary union;

2 is a sectional view through the first embodiment along section line II-II of Figure 1; 3 shows a section through the first embodiment along the section line III-III of Figure 1; 4 shows a sectional illustration through the first embodiment along the section line IV-IV from FIG. 1; 5 is a sectional view of a second embodiment of a rotary feedthrough according to the invention;

6 is a sectional view of a third embodiment of a rotary feedthrough according to the invention;

FIG. 7 shows a plan view of the third embodiment according to FIG. 6; FIG. and

8 shows a schematic representation of a system according to the invention.

In Figures 1 to 4, a first embodiment of a rotary feedthrough 1 according to the invention is shown. Figure 1 shows a side view of the rotary feedthrough 1, in Figure 2 is a sectional view of the rotary feedthrough 1 along the section line II-II shown in Figure 1.

The rotary feedthrough 1 comprises a shaft 10 which is rotatably mounted in a housing 20. The rotary feedthrough 1 is designed so that - regardless of the position of the shaft 10 relative to the housing 20 - heat transfer fluid in the liquid or gaseous state from an inlet and outlet port 21 in the housing 20 to an opening 11 on an end face 12 of the shaft 10 (or conversely) can flow.

Behind the opening 11 on one end face 12 of the shaft 10, a hollow bore 13 is provided. The hollow bore 13th is aligned concentrically with the axis of the shaft 10 and designed as a blind hole.

Furthermore, a pressure distribution chamber 14 is provided, which surrounds the shaft 10 in an annular manner. The pressure distribution chamber 14 is limited in the axial direction of the shaft 10 by two spring collars 15. The spring struts 15 are formed integrally with the shaft 10 and thus firmly and pressure-tightly connected thereto.

In the area of the pressure distribution chamber 14, a connection bore 16 is provided. The connection bore 16 is a through-bore through the wall of the hollow bore 13. Through the connection bore 16, the hollow bore 13 and pressure-distribution chamber 14 are connected to one another in a fluid-conducting manner.

Due to the connecting bore 16 and the hollow bore 13, the opening 11 on the one end 12 of the shaft 10 is connected to the pressure distribution chamber 14 so that heat transfer fluid from the pressure distribution chamber 14 to the opening 11 on one end face 12 of the shaft 10 can pass. A reverse flow direction of the heat transfer fluid is of course possible.

When the spring struts 15 are fixed and pressure-tight with the shaft 10 connected disc springs. "Pressure-tight" means that between spring struts 15 and the shaft 10 no fluid can pass.

The spring struts 15 can - as shown - be designed in one piece with the shaft. But you can also made separately from the shaft 10 and then with the shaft 10 pressure-pressure-tight, eg. By welding, be connected. The spring collars 15 are designed so that they can be elastically pivoted or deformed in the axial direction of the shaft 10.

The shaft 10 is mounted in two sealing and bearing bushes 30. Between sealing and bearing bushes 30 and the shaft 10 is a sliding bearing. In each case one of the sealing and bearing bushes 30 is flush against the side facing away from the Druckverteiler- 14 side 17 of a spring collar 15 and is biased against this. Between a sealing and bearing bush 30 and the adjacent spring collar 15 so there is a contact pressure. By the voltage applied to the spring collar 15 part of the sealing and bearing bush 30 prevents fluid between the sealing and bearing bush 30 and shaft 10 can pass.

The sealing and bearing bushes 30 are designed as flanged bushings, wherein the voltage applied to one side 17 of a spring collar 15 waist section 31 of the sealing and Lagerb chse 30 is configured crowned. Due to the crowned design of the collar section 31 of the sealing and bearing bushes 30 creates a small sealing surface 32 between a spring collar 15 and a sealing and bearing bushing 30. Due to the small sealing surface 32 there is a high surface pressure, which is a good sealing effect Episode has. Due to the crowned design of the collar section 31 of the sealing and bearing bushings 30, a high sealing effect is achieved even when there is a slight skewed position of the shaft 10 relative to a sealing and bearing bush 30. Is there in the pressure distribution chamber 14 a relation to the environment increased pressure, the spring struts 15 are pressed against the sealing and bearing bushes 30 due to this overpressure and their elastic deformability. The surface compression between spring struts 15 and sealing and bearing bushes 30 is thereby further increased. Due to the small sealing surface between the two aforementioned elements, the breakaway torque of the shaft 10 with respect to the sealing and bearing bushes 30 still remains low.

The sealing and bearing bushes 30 are rotatably supported in the housing 20. The housing 20 comprises a first and a second housing part 22, 23, which are sealed with a metallic 0-ring (for example, a pinch seal 24 made of copper) against each other. The pressure distribution chamber 14 is arranged in a 22 of the two housing parts 22, 23. The parting line 28 between the two housing parts 22, 23 thus does not extend through the pressure distribution chamber 14. The parting line 28 therefore does not form a possible leak at the pressure distribution chamber 14.

The above-mentioned inlet and outlet opening 21 is provided in the first housing part 22 and arranged so that it is in the assembled state of the rotary feedthrough 1 in connection with the pressure distribution chamber 14. The inlet and outlet opening 21 is provided with an internal thread 25. As a result, the connection of the inlet and outlet opening 21 to a pipeline system (not shown) is simplified. The housing 20 also has an opening 27 for the passage of the shaft 10.

The shaft 10 and the spring collars 15 connected in one piece are made of corrosion-resistant spring steel. provides. This ensures that even in extreme applications with temperatures of over 450 ° C and high pressures up to 150 bar, the spring collars 15 can still be deformed elastically. The sealing effect between Federbün- the 15 and sealing and bearing bushes 30 is guaranteed even in such extreme applications. The sealing and bearing bushes 30 are made of graphite. As a result, a lower friction between the sealing and bearing bushes 30 and the shaft 10 is achieved, which has a low breakaway torque of the rotary feedthrough 1 result.

The opening 11 of the blind hole 13 is designed as a sealing cone. In the region of the end face 12, at which the opening 11 of the hollow bore 13 is located, the shaft 10 has an external thread 18. At this external thread 18, a threaded ring 40 is fixed, which surrounds the shaft 10 annular and regularly distributed over its circumference through holes 41 having internal thread. At the threaded ring 40 can be against the shaft 10 non-rotatable, fastened relative to the housing 20 rotatable component. Due to the design of the blind hole 11 as a sealing cone can be a pressure-resistant, fluid-conducting connection between a rotatable member and the shaft 10 accomplish.

The threaded ring 40 is shown in detail in Figure 3 as a sectional view along the section line III-III of Figure 1.

The threaded ring 40 is screwed onto the external thread 18 of the shaft 10 and secured by a threaded pin 42 against unwanted release of the shaft 10. He is so rotatably connected to the shaft 10. The threaded ring 40 has uniformly over the circumference and around the opening for the shaft 10 distributed holes with internal thread 41. At these holes with internal thread 41, a component on the threaded ring 41 and thus with the shaft 10 can be connected by screws or bolts. The component is preferably designed so that it is also fluid-conductively connected to the opening 11 on the end face 12 of the shaft 10 during attachment to the threaded ring 41.

On the threaded ring 40, a torque support 43 is further provided, with the loads on the bore with internal thread 41 or inserted therein screws or bolts due to torques about the axis of the shaft 10 can be greatly reduced.

4 shows a sectional view of the housing 20 according to the section line IV-IV of Figure 1 is shown. The illustrated first housing part 22 has distributed over the circumference and arranged around the axis of the shaft 10 holes 26. The holes 26 are equipped with an internal thread. By means of screws or bolts, which engage in the internal thread of the holes 26, the second housing part 23 can be fixedly connected to the first housing part 22.

FIG. 5 shows a second exemplary embodiment of a rotary feedthrough 1 according to the invention. The rotary feedthrough 1 from FIG. 2 is largely identical to the rotary feedthrough 1 from FIGS. 1 to 4, for which reason reference is made to the statements there. The following will be only the differences between the two embodiments.

Instead of a single connecting bore 16 (cf., first exemplary embodiment, FIG. 2), two connecting bores 16 are provided in the exemplary embodiment shown in FIG. The two connecting bores 16 lie on a common axis and can be produced in a production step as a through-bore through the shaft 10. In the two connection holes 16 are provided, the flow resistance of the rotary feedthrough 1 can be reduced.

In the embodiment of Figure 5, the sealing and bearing bushes 30 are made in two parts and that with a socket part 33 and a collar part 34. The bushing parts 31 are the sliding bearing of the shaft 10 in the housing 20. The collar parts 32 of the sealing and bearing bushes 30 are each the side facing away from the pressure distribution chamber 14 side of one of the spring collars 15 of the shaft. By a voltage applied to the spring collar 15 waistband member 32 prevents fluid between the waistband 32 and the shaft 10 can pass. Thus, a sealing of the pressure distribution chamber 14 with respect to the outside of the shaft 10 or the environment is achieved. As in the first embodiment, the region of the sealing and bearing bushes 30 and the collar parts 32, which bears against one of the spring collars 15, designed crowned. FIG. 5 furthermore shows how a further component 90 can be fastened to the shaft 10. The component 90 has a fluid channel 91, whose one end 92 in the Sealing cone of the opening 11 of the hollow bore 13 of the shaft 10 can be inserted.

The component 90 further has a circumferential projection 93, which is engaged behind by a clamping ring 94. The clamping ring 94 is connected via screws 95 which engage in the holes with internal thread 41 of the threaded ring 40, with the threaded ring 40 and thus the shaft 10 rotatably connected. By pressing the component 90 or the one end 92 of the fluid channel 91 into the sealing cone of the opening 11 of the hollow bore 13, a pressure-tight, fluid-conducting connection is created between the hollow bore 13 and the fluid channel 91 of the component 90. Independently of the position of the component 90 With respect to the housing 20, fluid can pass from the inlet and outlet opening 21 in the housing 20 via the pressure distribution chamber 14, the connection bores 16 and the hollow bore 13 heat transfer fluid into the fluid channel 91 of the component 90 with the rotary feedthrough 1 according to the invention. Of course, a reverse flow direction is possible.

It is also possible that the threaded ring 40 is connected to the component 90 and an associated clamping ring engages behind a projection on the shaft 10 (not shown).

In Figures 6 and 7, a third embodiment of a rotary feedthrough 1 according to the invention is shown. The rotary feedthrough 1 of Figures 6 and 7 is identical in many parts to the rotary feedthrough according to Figures 1 to 4, and 5, which is why reference is made to the statements there. In the following, particular attention is paid to the differences between the exemplary embodiments. It is also self- understandable that individual aspects, such. Example, the configuration of the shaft 10 for connection to other components 90 (see Fig .. 5) are interchangeable between the individual embodiments.

The rotary feedthrough 1 according to FIGS. 6 and 7 differs mainly in that only one spring collar 15 is provided on the shaft 10. With this spring collar 15, the pressure chamber 14 is limited in the axial direction on one side. The limitation of the pressure chamber 14 in the axial direction on the other side is ensured by the housing 20 and the first housing part 22.

Since only one spring collar 15 is provided, only one sealing and bearing bush 30 is present. The sealing and bearing bush 30 is in this case made in two parts, wherein the bushing part 33 of the sliding bearing of the shaft 10 is used while the collar part 34 does not necessarily contribute to the storage of the shaft 10. The collar part 34 is, as described below, pressed with a bias to the spring collar 15, so that between the spring collar 15 and waistband 34 no liquid can pass through.

For generating said bias, a circumferential spring lip 29 is provided on the second housing part 23. The spring lip 29 is in the illustrated assembled state of the rotary feedthrough 1 on the collar part 34 of the sealing and bearing bush 30 and exerts a biasing force on the collar part 34 in the direction of the spring collar 15 due to elastic deformation. Since the spring lip 11 is also circumferential, the system is on the collar part 34 of the sealing and bearing bush 30 pressure-tight. So there can be no liquid keits between the collar portion 34 of the bearing bush 30 and the spring lip 29 abutting thereon pass.

The shaft 10 is still stored in a guide bush 40 in addition to the socket part 33 of the sealing and bearing bush 30. In order to prevent the shaft 10 from changing its position within the housing 20, a spacer 41 in the form of a ball is also provided, with which the distance between the shaft 10 and the housing part 22 is fixed. The shaft 10 is then held in position due to the bias on the spring collar 15 and the spacer 41, while remaining naturally rotatable.

The collar part 34 of the sliding and bearing bush 35 is made of graphite, the bushing part 33 and the guide bushing 40 can also be made of other material. The bushing part 33 and / or the guide bushing 40 may alternatively be designed as rolling bearings. The rotary feedthrough 1 according to the invention is suitable both for the rotary feedthrough of liquid heat transfer fluid and of heat transfer fluid in gaseous form. The latter is particularly required for use with thermal solar collectors in which an initially liquid heat transfer medium is heated to such an extent that a phase change takes place towards the gas form. A system 100 with a corresponding thermal solar collector 101 is shown in FIG. The system 100 includes a solar thermal collector 101 having an optical element 102 and an absorber 103. The optical element 102 is a linear fresnel lens perpendicular to the optical element 102 concentrating incident solar radiation on a focus line. In the focal line of the optical element 102, the absorber 103 is arranged. The absorber 103 is designed as an absorber tube through which heat transfer fluid can flow. The heat transfer fluid flowing through the absorber 103 is heated by the solar radiation focused on the absorber 103.

So that the solar radiation always impinges perpendicularly on the optical element 102, the solar thermal collector 101 is pivotable about a first and a second pivot axis 201, 202. Due to the pivotability about the two pivot axes 201, 202 a biaxial tracking of the solar thermal collector 101 to the sun is possible. The thermal solar collector 101 can always be aligned with the sun so that the sun's rays impinge perpendicularly on the optical element 102.

In spite of the pivotability about the two pivot axes 201, 202 required for the tracking, it must be ensured that the absorber 103 does not depend on the position of the thermal solar collector 101

Swivel axes 201, 202 is flowed through by heat transfer fluid. In order to achieve this, the system 100 comprises rotary unions 1 according to the invention. For an explanation of the rotary unions according to the invention, reference is made to FIGS. 1 to 5 and the above explanations.

In order to achieve the pivotability about the pivot axis 201, two rotary unions 1 are provided, which are aligned with their respective shaft 10 coaxial with the pivot axis 201 and with the end faces 12 of the respective shafts 10 opposite. The thermal solar collector 101 is fixedly connected to the shafts 10 of the rotary feedthrough 1. Due to the rotatable bearings of the shafts 10 in the housings 20 of the rotary unions 1, the solar collector 101 is pivotable relative to the housings 20 of the rotary unions 1 about the pivot axis 201. An additional storage of the solar collector 101 about the pivot axis 201 is not required.

The respective openings 11 in the shafts 10 of the rotary leadthrough 1 are connected in a fluid-conducting manner via tubes 104 to one end of the absorber 103. It is therefore possible that heat transfer fluid from the inlet and outlet 21 of a rotary feedthrough 1 passes through the rotary feedthrough 1 and through the pipes 104 to the absorber 102, flows through it, and again through pipes 104 and the other rotary feedthrough 1 to the outlet opening 21 of the other Rotary union 1 flows. This flow of heat transfer fluid is independent of the position of the solar collector 101 about the pivot axis 201 possible.

The housing 20 of the rotary feedthrough 1 are fixedly mounted on a frame 105. The frame 105 is rotatably supported about the pivot axis 202. The rotary feedthroughs 1 are aligned with their shaft 10 coaxial with the pivot axis 202 and are opposite to the respective end faces 12. The inlet and outlet openings 21 of the rotary feedthroughs 1 along the pivot axis 201 are connected via pipe 106, each having an opening 11 on the end faces 12 of the shaft 10 of the rotary feedthrough 1.

The frame 105 - and thus the pivot axis 201 and the thermal solar collector 101 - can be adjusted around the pivoting axis 202 pivot. Due to the rotary feedthroughs 1 along this pivot axis 202, heat transfer fluid can arrive independently of the position of the solar collector 101 about the pivot axes 201, 202 to the absorber 103 or be led away from it.

The housing 20 of the rotary feedthrough 1 about the pivot axis 202 are connected to a local infrastructure 300. The infrastructure 300 includes a pump 301, a turbine 302, and a piping system 304.

With the pump 301, heat transfer fluid is conveyed through the piping system 304 to an inlet opening 21 of a rotary feedthrough 1 about the pivot axis 202. The rotary feedthrough 1 is - as explained above with reference to FIGS. 1 to 5 - flowing through, so that the heat transfer fluid passes via the pipe connection 106 to one of the rotary feedthroughs 1 about the pivot axis 201. The heat transfer fluid also flows through this rotary feedthrough 1 and passes via the pipe 104 into the absorber 103. In the absorber 103, it is so strongly heated by the solar radiation focused on the absorber 103 with the optical element 102 that it changes its phase and becomes gaseous. The gaseous heat transfer medium is discharged via the pipes 104 from the absorber 103 and passes through the rotary unions 1 and the pipes 106 back into the piping system 303 of the local infrastructure 300. The gaseous heat transfer medium is then fed to the turbine 302, where it is for generating electrical energy is used. During this process, the heat transfer medium cools down again so strongly that it changes its phase again and is again in liquid form. The liquid ge heat transfer medium can then be supplied to the absorber 103 via the pump 301 as described.

Since the system 100 according to the invention comprises the rotary unions 1 according to the invention, it is possible that the absorber 103 is flowed through by heat transfer fluid, regardless of which position the thermal solar collector 100 occupies about the pivot axes 201, 202.

Claims

claims

Rotary feedthrough (1) for heat transfer fluid in the liquid or gaseous state for use in solar thermal systems, comprising a shaft (10) with a hollow bore (13), a pressure distribution chamber (14) surrounding the shaft (10) in an annular manner of at least one in the axial direction fixedly connected to the shaft (10) spring collar (15) is limited, and with a in the region of the pressure distribution chamber (14) arranged connecting bore (16) through the wall of the hollow bore (13), and at least one sealing and bearing bush (30), wherein each sealing and bearing bush (30) is flush against the side facing away from the pressure distribution chamber (14) side of their respective adjacent spring collar (15) fitting and biased against it.

Rotary feedthrough according to claim 1, characterized in that two sealing and bearing bushes (30) and two fixedly connected to the shaft (10) spring collars (15) are provided.

Rotary feedthrough according to claim 1 or 2, characterized in that the shaft (10) is slidably mounted in at least one sealing and bearing bush (30).

Rotary feedthrough according to one of the preceding claims, characterized in that the at least one sealing and bearing bush (30) is held in a housing (20) which has an opening (27) for the passage of the shaft (10) and an inlet and outlet opening (30). 21), wherein the inlet and outlet opening (21) opens into the pressure distribution chamber (14).

5. Rotary feedthrough according to claim 4, characterized in that the housing (20) has at least one circumferential spring lip (29) for generating the bias on a sealing and bearing bush (30).

6. Rotary feedthrough according to one of the preceding claims, characterized in that the hollow bore (13) is designed as an axial blind hole.

7. Rotary feedthrough according to one of the preceding claims, characterized in that the region of at least one sealing and bearing bush (30), which bears flush against a spring collar (15) is designed crowned.

8. Rotary feedthrough according to one of the preceding claims, characterized in that at least one

Sealing and bearing bush (30) in one piece as a collar bushing or in two parts with a socket part (33) and a collar part (34) is executed.

9. Rotary feedthrough according to one of the preceding claims, characterized in that the shaft (10) and / or the spring collars (15) are made of corrosion-resistant spring steel.

10. Rotary feedthrough according to one of the preceding claims, characterized in that at least one sealing and bearing bush (30) or at least the collar part (34) of a two-part sealing and bearing bush (30) made of graphite. Rotary feedthrough according to one of the preceding claims, characterized in that the housing (20) is designed in two parts, wherein preferably the pressure distribution chamber (14) in one of the two Gehäusetei le (22, 23) is arranged.

Rotary feedthrough according to one of the preceding claims, characterized in that at least one of the openings (11) of the hollow bore (13) is guided as a sealing cone.

Rotary feedthrough according to one of the preceding claims, characterized in that at the end of the shaft (10) to which an opening (11) of the hollow bore (13) is arranged, a threaded ring or a clamping ring is seen easily.

Rotary feedthrough according to one of claims 1 to 8, characterized in that the end of the shaft (10) on which an opening (11) of the hollow bore (13) is arranged, is designed for a cutting ring connection.

Rotary feedthrough according to one of the preceding claims, characterized in that a torque support (43) is provided on the housing (20), on the threaded ring (40) or clamping ring.

System comprising a at least one pivot axis (201) pivotally mounted, thermal solar collector (101) having an optical element (102) and an absorber (103), which is designed to flow with Wärmeträgerflu id, and at least one rotary feedthrough (1) with a Shaft (10) with a hollow bore (13), a ring surrounding the shaft (10) pressure distribution chamber (14) in the axial direction of wenigs least one fixed to the shaft (10) connected spring collar (15) is limited, and with a in the region of the pressure distribution chamber (14 ) arranged connecting bore (16) through the wall of the hollow bore (13), and at least one sealing and bearing bush (30), wherein each sealing and bearing bush (30) flush on the side facing away from the pressure distribution chamber side of their respective adjacent spring collar (15 ) and biased against it, wherein the shaft (10) of the Drehdurchfüh tion (1) coaxially with one of the at least one

Swivel axis (201) is arranged and the absorber (103) of the thermal solar collector (101) rotatably and fluidly connected to the hollow bore (13) or the pressure distribution chamber (14) of the rotary feedthrough (1).

System according to claim 16, characterized in that the rotary feedthrough (1) is designed according to one of claims 2 to 15.

System according to one of claims 16 or 17, characterized in that the optical element (102) is a linear Fresnel lens and / or the absorber (103) is an absorber tube.

19. System according to any one of claims 16 to 18, characterized in that a second pivot axis (202) is provided.