GB2298238A

GB2298238A - Radial turbine and compressor arrangements

Info

Publication number: GB2298238A
Application number: GB9503319A
Authority: GB
Inventors: Mark John Snee
Original assignee: MARK JOHN SNEE
Current assignee: MARK JOHN SNEE
Priority date: 1995-02-21
Filing date: 1995-02-21
Publication date: 1996-08-28
Also published as: GB9503319D0

Abstract

A radial turbine 10 and a radial compressor 15 are arranged to produce a power output from a working fluid which is heated and cooled to produce variations in its density. The radial turbine 10 draws heated fluid radially inwards and the radial compressor 15 drives cooled, denser fluid radially outwards. The arrangement operates in either an open or closed cycle. The fluid may be heated by sunlight or combustion and may be cooled by spraying water through nozzles 40. The working fluid may be liquid, gaseous or a mixture of liquid and vapour. An axial turbine (200, Fig 7) or stationary vanes may be provided between the radial turbine and the radial compressor.

Description

RADIAL TURBINE AND COMPRESSOR ARRANGEMENTS This invention relates to radial turbines and compressors, and more specifically to those which utilise the difference in density between a hot and a cold fluid.

At the present time it is known that water, sprayed in very fine droplets, will rapidly evaporate in warm air. As the water evaporates the surrounding air cools. It is also known that cool air is denser than warm air and that cool air surrounded by warm air will sink due to gravity. This principle can be exploited to generate power. It has been proposed in the prior art that warm air, cooled by water evaporation at the top of a high tower, will fall and the flow of air down the tower can be used to drive turbines located at the base of the tower.

The main problem associated with a tower is that work must be done in pumping the water to the top of it. To get more energy out than is put in, it is necessary to build a very tall tower.

According to the present invention there is provided a radial turbine which provides a movement of warm fluid radially inwards, a centrifugal compressor which provides a movement of cool fluid radially outwards means for heating and cooling said fluid and means for producing a power output from the rotation of said turbine and said compressor.

Specific embodiments of the invention will now be described by way of example with reference to the accompanying drawings in which:- Fig.1 shows a schematic cross-sectional view of a radial compressor and turbine mounted on a single shaft with an intermediate cooling chamber.

Fig.2 shows a turbine/compressor arrangement with a heat source and means for collecting the cooling fluid.

Fig.3 shows a turbine/compressor arrangement which operates in a closed cycle.

Fig.4 shows an external view of the closed cycle arrangement with heat source.

Fig.5 shows the closed cycle arrangement with a cooling chamber.

Fig.6 shows a further closed cycle arrangement with a cooling chamber.

Fig.7 shows the closed cycle arrangement with an additional axial turbine.

In the prior art, a tower is described which exploits the principle of cold, dense air falling due to gravity. The present invention uses centrifugal force to produce a similar effect.

Fig.1 shows a schematic cross-sectional view of a first embodiment of the invention. The radial turbine 10 and the centrifugal compressor 15 are securely mounted on the shaft 20. They preferably rotate at the same speed though they may, alternatively, be geared to rotate at different speeds and/or in opposite directions. The shaft 20 is mounted in bearings 25.

Heated air (or similar) enters the turbine 10 at it's periphery. The air travels radially inwards to the cooling chamber 35. Here, water is injected into the air stream by a plurality of nozzles 40. The water, represented by arrows 45, is fed to the nozzles 40 at a high pressure relative to the air pressure in the cooling chamber 35 so that it enters the air stream in the form of a very fine spray. This rapidly evaporates and cools the surrounding air. The cooled air/water vapour mixture then passes through the compressor 15. Arrows 50 show the flow of air/water vapour from the arrangement.

The turbine 10 is preferably larger in diameter than the compressor 15 so that more work is put in to drive the shaft 20 than is used to accelerate the air/water vapour through the compressor 15. Alternatively, if the turbine 10 and the compressor are made similar in size then a seperate turbine is preferably used to drive an output shaft. This turbine could be positioned either at the inlet to the turbine 10, between the turbine 10 and the compressor 15 or at the outlet of the compressor 15 and could be of either the axial or radial type.

The casings 55 of the turbine 10 and the compressor 15 rotate and the casing 60 of the cooling chamber 35 is stationary. Leakage to or from the cooling chamber 35 is prevented by rotating seals 65. Alternatively, the casings 55 are stationary and there is simply a small clearance between the turbine and compressor vanes 70 and 75. The turbine 10, compressor 15 and cooling chamber 35 are shaped to substantially conform to the optimum streamlines of the air flow.

Fig.2 shows a further embodiment of the invention in which the inlet air is heated by the sun. Reservoir 90 has a blackened lower surface and a transparent upper surface. Inlet air from the atmosphere passes between the two surfaces and is heated as it does so. The blackened surface absorbs solar energy and heats up. This heat is then transferred to the air by conduction and convection. The transparent surface simply traps in the heat and minimises losses to the atmosphere.

The heated inlet air is channelled from the reservoir 90 to the volute 80 which then guides the air into the turbine 10. A volute 85 also surrounds the outlet of the compressor 15. It's functions are to both guide the exhaust air and to collect condensed water for re-use in cooling. The water vapour is condensed by the increase in pressure induced by the compressor 15. Because the condensed water is much denser than the air it ils flung outwards to the periphery of the volute 85. From here, the water is fed back to the nozzles 40 through one or more pipes 100. The difference in pressure between the volute 85 and the cooling chamber 35 is preferably sufficient to produce the necessary fine spray at the nozzles 40.Additional pressure could be provided, if required, by one or more positive displacement pumps positioned somewhere along the length of the pipes 100.

In a further embodiment of the invention the reservoir 90 is replaced by one or more combustion chambers. The working fluid is then substantially the combusted gases produced in the combustion chamber. The exact shape and configuration of the combustion chamber may be borrowed from existing fuel burning technology.

In a further embodiment of the invention using solar energy, the air from the exhaust of the compressor 15 is recycled back through the reservoir 90. This may form a completely closed cycle, in which case, no cooling water vapour is lost to the atmosphere.

Fig.3 shows a further embodiment of the invention in which the turbine 10 and the compressor 15 are completely enclosed and the working fluid operates in a closed cycle. The working fluid may be either liquid, gaseous or a mixture of liquid and vapour. The turbine 10 is preferably larger in diameter than the compressor 15 and the radial vanes of each are preferably joined or in close contact with each other at the hub 105.

Because the tangential velocity of the inlet to the turbine 10 is greater than that of the outlet of the compressor 15, intermediate stationary vanes 107 are used to guide the working fluid so that it conforms to the optimum streamlines. The vanes 107 are attached to the stationary portion 108 of the casing 117 which is itself attached to vanes 109 mounted on the outer wall 125.

Heating and cooling of the working fluid is preferably provided by air or combusted gases flowing through the passages 110 and 115 which surround the casing 117. Cool gases flow through the passage 110 and channel heat away from the working fluid. To help this heat transfer the outer casing 117 of the compressor 15 and turbine 10 is preferably made from a good heat conducting material such as aluminium. The flow of gases in the passage 110 is preferably in the direction shown by the arrows 120 i.e. from the periphery to the centre.

Hot gases flow into passage 115 at the centre and out at the periphery.

Heat is transferred to the working fluid from the hot gases through the outer casing 117. The cavity 119 is preferably filled with suitably insulating material to minimise heat transfer between the turbine 10 and the compressor 15. Preferably, the outer walls 120 and 125 are stationary and are also insulated so there is little heat transfer to or from the atmosphere.

Water nozzles may be place in the cooling passage 110 to inject a cooling spray which evaporates on close contact with the compressor casing 117.

The water vapour produced is then later condensed in the heating passage 115 and collected from the volute 135 surrounding the exhaust of the heating passage 115 to be recycled through piping back to the nozzles in the cooling passage 110.

Fig.4 shows a view of the present arrangement from the outside in which the inlet to the cooling passage 110 is surrounded by volute 130 and the outlet of the heating passage 115 is surrounded by volute 135. The gases from the cooling passage 110 are channelled to the reservoir 140 where they gain further heat from the sun. The reservoir 140 is similar to the reservoir 90 mentioned previously. It has a blackened lower surface and a transparent upper surface and the gases pass between the two. From the reservoir 140, the hot gases are then channelled to the heating passage 115 and then out through the volute 135.

The heating and cooling gases are preferably driven around the circuit by radial vanes 150 attached to the casing 117 in the heating passage 115. The gases are compressed and cooled as they pass through the heating passage 115. The water vapour condenses and further heat is supplied to the working fluid. To ensure that the optimum amount of heat is transferred to the working fluid, the rate of flow of gases through the arrangement can be limited by restricting the size of the outlet 145 of the heating passage 115. The gases passing through the outlet 145 expand and cool as they enter the volute 135. The condensed water from the heating passage 115 does not re-evaporate as it enters the volute 135 because the temperature is preferably sufficiently low.

Fig.5 shows a further embodiment of the present invention in which the working fluid is in the liquid/vapour state. In operation, the liquid is flung to the periphery of the turbine/compressor arrangement and the vapour occupies the remaining space. The pressure in the arrangement is such that the boiling point of the liquid is slightly lower than the inlet temperature of the cooling gases in the cooling passage 110. The figure also shows a cooling chamber 35 with nozzles 40. Liquid is tapped off from the periphery of the turbine/compressor chamber 170 through a plurality of pipes 160. The pipes 160 direct the liquid to one or more channels 165 in the shaft 20 which feed to the nozzles 40. The nozzles preferably rotate with the shaft 20 and the turbine/compressor arrangement.

The pipes 60 are preferably stationary and sealably engage with the shaft 20 and the turbine/compressor chamber 170. The pressure difference between the periphery of the turbine/compressor chamber 170 and the cooling chamber 35 is preferably sufficient to pump the liquid through the nozzles 40 to produce a fine spray. Additional pressure may be provided by one or more pumps positioned somewhere along the length of the pipes 160.

Fig.6 shows an alternative arrangement of the present invention in which both the pipes 180 and the nozzles 40 rotate with the compressor 15 and the turbine 10. The liquid is channelled through one or more pipes 180, through one or more channels 185 in the shaft 20 and out to a positive displacement pump. The liquid is then pumped through one or more channels 190 in the shaft 20 and through to the nozzles 40 in the cooling chamber 35.

Fig.7 shows a further embodiment of the invention in which an axial turbine 200 is mounted on the shaft 205. The compressor/turbine arrangement 170 is mounted on the hollow member 210. The shaft 205 is mounted in bearings 215 and the hollow member 210 is mounted in bearings 220. Preferably, the turbine 200 and the turbine/compressor arrangement 170 counter-rotate.

To drive a single output shaft the hollow member 210 and the shaft 205 are preferably provided with a suitable gearing arrangement. The working fluid may be gaseous, liquid or liquid/vapour. A cooling chamber may be located immediately upstream or downstream of the turbine 200 and it's operation would be similar to that of the previous examples.

The turbine 10 and compressor 15 are preferably equal in diameter or at least similar. Their vanes 230 are preferably continuous at the periphery.

The shape of the vanes 230 and the shape of the blades of the turbine 200 should substantially conform to the optimum streamlines of the flow of the working fluid.

In a further embodiment of the invention the turbine 200 is replaced by stationary vanes. The shaft 205 is also stationary so that the power output is obtained solely from the rotating hollow member 210.

Claims

1. A radial turbine and compressor arrangement comprising a radial turbine which provides a movement of warm fluid radially inwards, a centrifugal compressor which provides a movement of cool fluid radially outwards, means for heating and cooling said fluid and means for producing a power output from said turbine and said compressor, the arrangement operates in either an open cycle or with additional features, in a closed cycle and in both cases the compressor stage occurs after the turbine stage and the arrangement sigificantly utilises the difference in density between the said warm fluid and said cool fluid.

2. A radial turbine and compressor arrangement as claimed in Claim 1 wherein the said radial turbine and said centrifugal compressor are securely mounted on the same shaft.

3. A radial turbine and compressor arrangement as claimed in Claim 1 wherein the said radial turbine and said centrifugal compressor are mounted on separate shafts which are in some way connected or geared to rotate at different speeds and or in different directions.

4. A radial turbine and compressor arrangement as claimed in Claim 2 or Claim 3 wherein the working fluid is preferably air, combusted gases, liquid or liquid/vapour mixture.

5. A radial turbine and compressor arrangement as claimed in any preceding claim wherein the said working fluid is heated by a combustion process, thermonuclear princess, solar energy or similar.

6. A radial turbine and compressor arrangement as claimed in any preceding claim wherein the said working fluid is air or combustion products and there is a cooling chamber located upstream of the said compressor which directs water or similar into the working fluid stream through one or more nobles producing a fine spray which rapidly evaporates and cools the working fluid.

7. A radial turbine and compressor arrangement as claimed in any preceding claim wherein the shape and size of the said turbine relative to the said compressor is such that the power output created by the said working fluid flowing through the said turbine is greater than the power the arrangement uses in driving the said working fluid through the said compressor.

8. A radial turbine and compressor arrangement as claimed in any preceding claim wherein the arrangement operates in a closed cycle and the working fluid passes from the outer portion of the said turbine radially inwards towards the hub then to said compressor and radially outwards to the outer portion of the said compressor, then through stationary guide vanes and then back to the outer portion of the said turbine.

9. A radial turbine and compressor arrangement as claimed in Claim 8 wherein the closed cycle turbine/compressor arrangement is encased in a jacket which directs heating fluid to the said turbine and cooling fluid to the said compressor in such a way that heat is transferred to and from the said working fluid by conduction through the walls of the said turbine and said compressor.

10. A radial turbine and compressor arrangement as claimed in Claim 9 wherein the said heating and cooling fluid is heated by a combustion process, a solar energy process or similar and is cooled by the evaporation of a fluid such as water which is injected into the cooling fluid stream in the form of a fine spray.

11. A radial turbine and compressor arrangement as claimed in Claim 10 wherein the working fluid is a liquid/vapour mixture and the liquid is tapped off from the periphery of the turbine/compressor chamber through a plurality of pipes which then feed the fluid back to nozzles in the inner radial portion of the said turbine/compressor chamber to create a cooling spray.

12. A radial turbine and compressor arrangement as claimed in any preceding claim wherein the vanes of the said turbine, said compressor and any stationary vanes all conform substantially to the optimum streamlines of the fluid flows.

13. A radial turbine and compressor arrangement sustantially as described herein with reference to Figures 1-7 of the accompanying drawing.