GB1575684A

GB1575684A - Installation proveded with a hollow rotor

Info

Publication number: GB1575684A
Application number: GB26952/77A
Authority: GB
Original assignee: Ultra Centrifuge Nederland NV
Current assignee: Ultra Centrifuge Nederland NV
Priority date: 1976-06-28
Filing date: 1977-06-28
Publication date: 1980-09-24
Also published as: BR7704198A; AU2566377A; IN147066B; AU509733B2; DE2729134A1; NL7607040A

Description

(54) INSTALLATION PROVIDED WITH A HOLLOW ROTOR (71) We, ULTRA CENTRIFUGE NEDER LAND N.V., a body Corporate organised and existing under the laws of The Netherlands, of Schevenigseweg 44, The Hague, The Netherlands, do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement: The present invention relates to a rotary heat machine which either produces work, in this case rotary drive, from heat or effects transfer of heat when driven. Thus, for example, the heat machine may act as a heat engine which generates rotation by absorbing solar energy, or as a heat pump or cooling apparatus.

In accordance with the invention there is provided a rotary heat machine comprising a rotor mounted in a housing and so arranged that a fluid medium circulates within the rotor and is subject to an increase of pressure and a reduction in pressure alternating with changes of temperature by heat exchange, wherein the rotor is a hollow vessel within which the medium is compressed by centrifugal action near one end of the vessel, flows in heat-exchanging contact with the inner surface of the peripheral wall of the vessel to the other end, and there expands centripetally and wherein at least one region of the outer surface of the peripheral wall of the vessel has a high thermal radiation exchange coefficient.

If such a machine is to act as a heat pump the rotor is driven and the thermodynamic processes within the rotor have the effect of transferring heat from the inner part of the vessel to the peripheral wall, from which it is then radiated, especially in the region having a high thermal radiation exchange coefficient, that is to say a high emission coefficient and correspondingly a high absorption coefficient. Fluid circulated through a coil surrounding the housing can therefore be heated by the radiated heat, while fluid passed through a duct to the axis of the rotor will be cooled by heat exchange with the fluid circulating within the rotor.

If the machine is to be used as heat engine heat is supplied to the peripheral wall of the rotor by radiation and the inner part of the rotor is preferably cooled by passaged of a cooling fluid through a duct close to the axis of the rotor, with the result that the circulation of fluid set up in the rotor will drive the rotor.

In a preferred construction the rotor rotates about a central hollow shaft which is fixed against rotation and provides the duct for the flow of cooling fluid which cools the fluid within the rotor by heat exchange. The central shaft may also support non-rotating flow-guiding structure disposed within the hollow rotor vessel. The rotor itself is preferably provided with guide vanes at opposite ends for conversion of the rotation of the into the movement of the fluid or vice-versa.

Externally, the rotor is preferably given the shape of a cylinder, which can be placed inside a substantially cylindrical housing.

The said region of the peripheral wall of the rotating vessel can be blackened in part, or the surface can be provided in part with a finely ribbed or knurled structure. The latter can, for example, be rolled or pressed into the rotor, but such a structure can also be obtained by winding a fibre of a material having good heat-conducting properties, such as carbon fibre, about the rotor, in such a way that a distance remains between the fibres which is equal to the order of magnitude of the fibre thickness. Such windings are preferably in criss-cross form, so that an open cavity (pore) is formed at the junctions of each pair of fibres. All this contributes very materially to enhancing the heat exchange with the aid of radiation.

Part of the outer surface of the rotor can also be given a highly reflecting finish, in contrast to the rest of the outer surface, which is not made reflecting or to a much lesser extent.

The blackened or correspondinedy treated surface is advangeously concentrated near the rotor end having a centrifugal flow pattern of the medium. As a result, a heat gradient of such a nature is produced along the rotor that the thermodynamic process which takes place inside the rotor is supported as effectively as possible. There are numerous ways in which the pattern of the proportion of, for example, blackened and nonblackened surface in the direction of the rotor axis along the outer surface of the rotor can be so optimized that the effect obtained is as favourable as possible.This can be accomplished by having bands with a higher thermal radiation exchange coefficient and with, for example, a constant width, alternate with intermediate bright bands with a lower coefficient, in such a way that the successive bands of the latter type exhibit a progressively increasing width.

Part of the centripetally expanded medium can be conveyed outside the rotor if required, where it may be subjected to a process of heat exchange, for example, instead of this taking place inside the rotor.

Since the amount of medium inside the rotor vessel must remain constant, at least in otherwise identical operating conditions, this implies that at least a portion of the medium which is centrifugally pressurized in the rotor can be similarly supplied from outside the rotor in such cases.

Some examples of embodiment of the invention will be explained in further detail on the basis of the following figures, of which: Fig. 1 is a vertical partial transverse section through an installation according to the invention; Fig. 2 is a variant of Fig. 1 showing a transverse section through the inside of a rotor which is placed inside a housing provided with a heat-exchange coil; Fig. 3 shows schematically, in longitudinal section, a heat machine in accordance with the invention in its most general form; Fig. 4 shows a rotor of a machine according to the invention, provided on the outside with alternating bands of black and of bright material; Fig. 5 shows a variant of Fig. 4, where the black bands all have the same width.

In Fig. 1, a housing 1 accommodates a cylindrical rotor 2, which is rotatable about a vertical shaft. This rotor is supported on the underside, via the shaft 3, in a bearing 4. On the lower end of the shaft 3, a rotor 5 of an electromotor is mounted. the stator of which bears the number 6. The parts 7 and 8 are seals. The bearings on the upper side are not shown. Cooling: fins 9 are fitted on the outside of the housing 1. The figure indicates that the upper end of the rotor has been eiven a black surface, the lower part 11 of this rotor having been left bright.

Fig. 2 shows a transverse section in greater detail of a rotor which can be used as a heat pump, a cooling machine or an energy producer. This design will be described, it being assumed that the installation is to be used as a heat pump.

The rotor is here provided with a cylindrical outer jacket 12, which is secured at both ends to rotor end walls 13 and 14. The end wall 14 bears a hub 15 which is supported in an end bearing 16 which is fastened in a sleeve 17 of the end cover 18 of the housing. The rotor end wall 13 is provided analogously with a sleeve-like part 19, no details of the bearing system of which are shown. Inside the rotor, the end wall 13 is designed as a centrifugal compressor 20; similarly, the inside of the end wall 14 is designed as a centrifugal turbine 21. A system of guiding passages is fixed in position between these two rotor parts and connected to a central hollow shaft 22. The guiding passages consist first of all of passages 23, in which the medium from the compressor rotor is received and diverted in axial direction.Passages 24 receive the medium from the compressor and divert it to the inlet of the turbine rotor 21. Passages 25 connect the outlet of the turbine 21 to the inlet of the compressor 20. Cooling fins 26 are so fitted in these last guiding passages as to be capable of transferring heat from the inside of the shaft 22 to the passages 25, and conversely.

The inside of the cylindrical jacket 12 of the rotor forms the boundary of guiding passages 27, which increase in cross-sectional area slightly near the inlet of the guiding blades 24 of the turbine. The outside of a housing 28 in which the rotor is mounted is covered with a heat-exchange coil 29 which is in good heat-conducting contact with it.

The operation of the installation described is as follows: When the apparatus is to serve as a heat pump, the operating medium can be constituted, for example, by one of the materials sold under the Registered Trade Mark "Freon". With such a heat pump, the operation takes place entirely in the range of saturation of the operating medium. This medium absorbs heat from the fins 26 during its flow through the guiding passages 25.

These fins are supplied with heat from a medium which is passed through the inside of the shaft 22. This medium can come, for example, from a soil-water reserve which contains water at a temperature that is too low to allow it to be used for an application like heating. After the circulating medium in the rotor has been heated, compression takes place in the compressor 20, whereupon the medium, having been heated by the compression, continues its flow through the guiding passages 27. This makes it necessary for the outside of the cylindrical wall 12 to be so finished between annular boundaries indicated by references 30 and 31 that this surface has a high heat emissivity. In the area mentioned, therefore, this surface can, for example, be blackened. The inside surface of the housing opposite this blackened surface can be similarly treated if required.

As a result of this blackening, the heat from the hot medium contained in the guiding passages 27 is radiated to the inside wall of the housing 28 and is transmitted by conduction to the heat-exchange coil 29. A heat-transferring medium, which flows through this coil, enters at 32 at a relatively low temperature and is passed on through the discharge pipe 33 at a much higher temperature, for example to radiators for domestic heating.

The medium, having reached the end of the guiding passages 27, is then deflected by the guiding blades 24 to the inlet of the turbine 21. Following its expansion therein, it arrives in partly liquid form in the guiding passages 25. As a result of heat absorption, it passes largely into vapour form, whereupon having finally reached the compressor 20, the application of heat causes also the last liquid parts to be reconverted into vapour form.

The turbine, the compressor and all guiding passages are provided with an anti-cavitation layer. The numbers 34 and 35 indicate seals which prevent operating medium from escaping from the interior of the rotor.

Figure 3 shows diagramatically the invention in its most general form. The housing 36 is provided with a cooling jacket 37 having an inlet 38 and an outlet 39, within which housing a rotor 40 is rotatably ininstalled and supported in bearings which are not shown. An operating medium can so follow a circuit inside this rotor that it moves downwards along the inside wall of the rotor in the direction of flow indicated by the arrow 41, whereupon it is deflected in centripetal direction near the end cover 42 and then flows upwards in the direction indicated by the arrows 43 towards the upper cover 44, where it is again deflected and resumes its return flow in centrifugal direction towards the outside of the rotor.

The numbers 45 and 46 indicate sleeveshaped rotor parts through which, if required, at least a portion of the medium used can be conveyed outside the housing 36, for heat exchange purposes it being also possible to return a portion of this medium to the rotor through the other connection, such as 46 in this case. The blackened portion of the outside of the rotor wall extends around the whole periphery between the limits indicated by references 47 and 48.

This constitutes the best manner of removing to the cooling jacket 37 the heat generated during the pressure increase near the top cover 44.

Fig. 4 finally shows the manner in which the blackening can be distributed over a rotor. The black bands 49 are here so divi- ded over the length of the rotor that a major part of the blankening is concentrated near the rotor end 50 within which centrifugal compression of the medium occurs.

According to an alternative version shown in Fig. 5, use can also be made of black bands 51 which all have the same width. In this case, however, the distance between the bands mutually is great near the upper end 52 of the rotor and small near the lower end 53. In between these areas, the band width of the bright rotor parts exhibits a pattern of gradual change.

WHAT WE CLAIM IS:- 1. A rotary heat machine comprising a rotor mounted in a housing and so arranged that a fluid medium circulates within the rotor and is subject to an increase of pressure and a reduction in pressure alternating with changes of temperature by heat exchange, wherein the rotor is a hollow vessel within which the medium is compressed by centrifugal action near one end of the vessel, flows in heat-exchanging contact with the inner surface of the peripheral wall of the vessel to the other end, and there expands centripetally and wherein at least one region of the outer surface of the peripheral wall of the vessel has a high thermal radiation exchange coefficient.

2. A heat machine as claimed in claim 1 in which the said region of high thermal radiation exchange coefficient is a blackened region.

3. A heat machine as claimed in claim 1 in which the said region of high thermal radiation exchange coefficient is ribbed or knurled.

4. A heat machine as claimed in claim 3 in which the ribbing or knuling has been formed by rolling.

5. A heat machine as claimed in claim 3 in which the ribbing or knurling is formed by a winding of a fibre having good thermal conductivity.

6. A heat machine as claimed in claim 5 in which the fibre is carbon fibre.

7. A heat machine as claimed in claim 5 or 6 in which the fibre is wound in crisscross form to form cavities between the crossing fibres.

8. A heat machine as claimed in any of the preceding claims in which the said region of high thermal radiation exchange coefficient is near the end of the rotor at which the medium is compressed by centrifugal action.

9. A heat machine as claimed in any of the preceding claims in which another region or regions of the said outer surface have a bright reflective finish.

**WARNING** end of DESC field may overlap start of CLMS **.

Claims

**WARNING** start of CLMS field may overlap end of DESC **. indicated by references 30 and 31 that this surface has a high heat emissivity. In the area mentioned, therefore, this surface can, for example, be blackened. The inside surface of the housing opposite this blackened surface can be similarly treated if required. As a result of this blackening, the heat from the hot medium contained in the guiding passages 27 is radiated to the inside wall of the housing 28 and is transmitted by conduction to the heat-exchange coil 29. A heat-transferring medium, which flows through this coil, enters at 32 at a relatively low temperature and is passed on through the discharge pipe 33 at a much higher temperature, for example to radiators for domestic heating. The medium, having reached the end of the guiding passages 27, is then deflected by the guiding blades 24 to the inlet of the turbine 21. Following its expansion therein, it arrives in partly liquid form in the guiding passages 25. As a result of heat absorption, it passes largely into vapour form, whereupon having finally reached the compressor 20, the application of heat causes also the last liquid parts to be reconverted into vapour form. The turbine, the compressor and all guiding passages are provided with an anti-cavitation layer. The numbers 34 and 35 indicate seals which prevent operating medium from escaping from the interior of the rotor. Figure 3 shows diagramatically the invention in its most general form. The housing 36 is provided with a cooling jacket 37 having an inlet 38 and an outlet 39, within which housing a rotor 40 is rotatably ininstalled and supported in bearings which are not shown. An operating medium can so follow a circuit inside this rotor that it moves downwards along the inside wall of the rotor in the direction of flow indicated by the arrow 41, whereupon it is deflected in centripetal direction near the end cover 42 and then flows upwards in the direction indicated by the arrows 43 towards the upper cover 44, where it is again deflected and resumes its return flow in centrifugal direction towards the outside of the rotor. The numbers 45 and 46 indicate sleeveshaped rotor parts through which, if required, at least a portion of the medium used can be conveyed outside the housing 36, for heat exchange purposes it being also possible to return a portion of this medium to the rotor through the other connection, such as 46 in this case. The blackened portion of the outside of the rotor wall extends around the whole periphery between the limits indicated by references 47 and 48. This constitutes the best manner of removing to the cooling jacket 37 the heat generated during the pressure increase near the top cover 44. Fig. 4 finally shows the manner in which the blackening can be distributed over a rotor. The black bands 49 are here so divi- ded over the length of the rotor that a major part of the blankening is concentrated near the rotor end 50 within which centrifugal compression of the medium occurs. According to an alternative version shown in Fig. 5, use can also be made of black bands 51 which all have the same width. In this case, however, the distance between the bands mutually is great near the upper end 52 of the rotor and small near the lower end 53. In between these areas, the band width of the bright rotor parts exhibits a pattern of gradual change. WHAT WE CLAIM IS:-

1. A rotary heat machine comprising a rotor mounted in a housing and so arranged that a fluid medium circulates within the rotor and is subject to an increase of pressure and a reduction in pressure alternating with changes of temperature by heat exchange, wherein the rotor is a hollow vessel within which the medium is compressed by centrifugal action near one end of the vessel, flows in heat-exchanging contact with the inner surface of the peripheral wall of the vessel to the other end, and there expands centripetally and wherein at least one region of the outer surface of the peripheral wall of the vessel has a high thermal radiation exchange coefficient.

6. A heat machine as claimed in claim 5 in which the fibre is carbon fibre.

10. A heat machine as claimed in any

of the preceding claims having several regions of high thermal radiation exchange coefficient in the form of annular zones of the same width, alternating with zones having a low thermal radiation exchange coefficient.

11. A heat machine as claimed in claim 10 in which the zones of low radiation exchange coefficient have progressively increasing widths.

12. A heat machine as claimed in any of the preceding claims in which the housing has a heat-exchange coil around its outer surface.

13. A heat machine as claimed in any of the preceding claims having a central hollow shaft which is stationery and around which the rotor rotates, fluid passing through the shaft being in heat-exchange relationship with the medium within the rotor.

14. A heat machine as claimed in claim 13 in which the central shaft supports nonrotating flow-guiding structure extending within the rotor to guide the circulation of the medium within the rotor.

15. A heat machine as claimed in claim 14 in which the rotor includes flow passages extending substantially parallel to the axis of the rotor adjacent the peripheral wall of the rotor.

16. A heat machine as claimed in claim 14 or 15 in which the rotor has guide vanes at its ends for effecting transfer of energy between the circulation of the medium in the rotor and the rotation of the rotor.

17. A heat machine as claimed in any of the preceding claims including means for withdrawing part of the centripetally expanded medium from the rotor for heating by heat exchange before it is returned to the rotor.

18. A heat machine as claimed in any of the preceding claims in which the inside of the housing is provided at least in part with a surface layer facilitating thermal radiation exchange.