GB2095339A - Hydraulic turbine - Google Patents

Abstract

The turbine is for use in the accumulator-turbine system as described in patent No. 1561261 and includes a rotor 203 having peripheral blades 204, 205, 206 onto which driving liquid is directed by nozzles 201 which also draw in recirculating liquid through pipes 215 from the turbine drain compartments. The blades exhaust from both sides of the rotor into a high vacuum. Side disc plates can be adjusted relative to the rotor for control purposes. <IMAGE>

Description

SPECIFICATION Hydraulic rotor and nozzle arrangement This invention relates to a hydraulic turbine rotor, and is concerned particularly with providing an improvement to the blading arrangement and nozzles, and the recirculation of drainage fluid from a turbine extraction pump.

The invention has been developed primarily with a view to improving the construction disclosed and claimed in United Kingdom Patent Specification No.

1,561,261 in the name of D. G. Purvis.

The present invention will now be described in more detail, by way of example only, with reference to the accompanying drawings in which Figures 1 to 5 show an accumulator-turbine system and are identical with Figures 1 to 5 of U.K. Patent Specification No. 1,561,261, and Figure 6 shows an improved rotor for use in the system disclosed in the specification as aforesaid.

Figure 1 is a schematic view of a first accumulator of the system; Figure 2 is a schematic view of à second accumulator coupled with the first accumulator shown in Figure 1; Figure 3 is a schematic view of a turbine of the system; Figure 4 is a schematic view of ancillary parts of the system; Figure 5 is a diagrammatic illustration of the manner by which the arrangements of Figures 1 to 4 should be combined; and Figure 6 is a schematic illustration of a modification of the construction of rotor blades and nozzle positions to be incorporated in the turbine disclosed in the aforesaid specification.

There will now be described in detail the system disclosed in Figures 1 to 5. Referring now to Figure 1 of the drawings, a first hydraulic accumulator comprises a vertical tube 1 and a heavy piston 2 which is moveable freely within the vertical tube 1. The piston 2, when moving to its top position within the accumulator tube 1, can move an auxiliary valve 3 and a relief valve 4 to the open position. The auxiliary valve 3 is connected to the discharge side by a pipeline 7 and a junction pipe 8 to a slide valve 5 of a piston operated vacuum and air valve 6. The auxiliary valve 3 is connected on the inlet side to a main supply pipeline 9 by pipelines 10, 11 and 12 respectively.

The relief valve is connected on the inlet side by pipelines 13, 14 and 24 to the slide valve 5 of the valve 6, and is connected on the outlet side by pipeline 15 to a main drain pipeline 16. Thereby with the auxiliary valve 3 and the relief valve 4 in the open positions, the valve 6 can move over from right to left, opening the air valve and closing the vacuum valve thereto. The vacuum and air valve 6, when open to air, will increase the pressure within the accumulator tube 1 and above the main piston 2 to increase the discharging force of the main piston 2; through discharge valve 78 when automatically required.

The same heavy piston 2, when moving to its bottom dead centre position, can move an auxiliary valve 19, relief valve 20 and 21 and a magnet and spring vacuum valve switch 22 to open and switchon positions. The auxiliary valve 19 is connected on the discharge side by pipelines 23, 14 and 24 to the slide valve 5 and is connected on the inlet side to main supply pipeline 9 by pipelines 11 and 10 and isolating valve 25.

The relief valve 20 is connected on the inlet side by pipeline 26 to the auxiliary pipeline 7 and is connected on the outlet side by pipeline 27 to a main drain pipeline 16.

The auxiliary valve 19 is also connected on the discharge side by pipeline 23 and 14to a hydraulic change over valve 28. The relief valve 21 is connected on the inlet side by pipeline 29 to auxiliary discharge pipelines 30 and 31 of a second accumulator comprising accumulator tube 35 and free piston 36. The relief valve 21 is connected on the outlet side by pipelines 32 and 27 to the main drain pipeline 16.

The magnet and spring valve switch 22 is arranged to operate a magnet and spring valve 33 which is connected on its inlet side to a port opening 57 in the side of accumulator tube 2 and on its outlet side to a main vacuum pipeline 103 by pipeline 34. In consequence with the auxiliary valve 19, the relief valves 20 and 21 and the magnet and spring valve 22 in the open and switch-on positions, the piston operated vacuum and air valve 6 can move over from left to right opening the vacuum valve and closing the air valve thereof. At the same time, the main hydraulic change-over valve 28 can move over from left to right to shut-off the first accumulator and to discharge the second accumulator into the main hydraulic pipeline 9.

The vacuum and air valve 6, and the magnet and spring valve 33 when open to vacuum, will reduce the pressure within the accumulator tube 1, above the main piston 2 to increase the pressure difference between the underside of main piston 2 and the topside of main piston 2. The aforementioned pressure difference, on reaching the necessary absolute pressure difference will cause the main piston 2 to rise in the accumulator tube 1. (The pressure difference in each case depends on the length of the piston).

With the main piston 2 in vertical transit, the auxiliary valve 19, the relief valves 20 and 21 and the valve switch 22 can return to closed position. A nonreturn fluid inlet valve 58 can move to the open position and a non-return discharge valve 78 can move to the closed position. The non return valve 78 is connected by pipeline 80 to the inlet side of the main hydraulic changeover valve 28 and therethrough to connect by pipeline 82 to the main hydraulic pipeline 9.

Referring now to Figure 2, the second accumulator comprises vertical tube 35 and heavy piston 36 which is able to move freely within the vertical tube 35. The main piston 36, on reaching its top centre position within the accumulatortube 35, can move auxiliary valve 37 and relief valve 38 to the open positions. The auxiliary valve 37 is connected on the discharge side by pipeline 39 and junction pipeline 40 to the slide valve 41 of a vacuum and air valve 42, and on the inlet side is connected to main supply pipeline 9 by pipeline 10. The relief valve 38 is con nected on the inlet side by pipelines 43,31 and 49 to the slide valve 41 of the vacuum and air valve 42, and is connected on the outlet side by pipeline 44 to a main drain pipeline 16.Thereby with The auxiliary valve 37 and the valve 38 in the open positions, the piston operated vacuum and air valve 42 can move over from right to left thereby opening the air valve and closing the vacuum valve thereof. The valve 42, when open to air, will increase the pressure within the accumulator tube 35 and above the main piston 36 to increase the discharging force of the main piston 36, through accumulator discharge valve 79, when automatically required. The non return valve 79 is connected by pipeline 8 to the inlet side of the main hydraulic change over valve 28, and therethrough to connect by pipeline 83 to the main hydraulic pipeline 9. Whereby, with the main hydraulic change over valve 28 moved over from left to right, pressurised fluid can flow from the second accumulator to the main hydraulic pipeline 9.

The heavy piston 36, when moving to its bottom centre position, can move the auxiliary valve 45, the relief valves 46 and 47 and the magnet and spring vacuum valve switch 48 to the open and switch-on positions. The auxiliary valve 45 is connected on the discharge side by pipelines 31 to the slide valve 41 of the piston operated vacuum and air valve 42, and is connected on the inlet side to main supply pipeline 9 by pipelines 50, 10 and isolating valve 25.

The relief valve 46 is connected on the inlet side by pipeline 51 to the auxiliary pipeline 39, and is connected on the outlet side by pipeline 52 to main drain pipeline 16.

The auxiliary valve 45 is also connected on the discharge side by pipeline 31 and 30 to hydraulic change over valve 28. The relief valve 47 is connected on the inlet side by pipeline 53 to the auxiliary discharge pipelines 14 and 23 of the first accumultor, and is connected on the outlet side by pipelines 54 and 52 to the main drain pipeline 16.

The magnet and spring valve switch 48 is arranged to operate a magnet and spring valve 102 which is connected on its inlet side to a port opening 58 in the side of accumulatortube 35, and on its outlet side to a main vacuum pipeline 104. In consequence with the auxiliary valve 45, the relief valve 46 and 47 and the magnet and spring valve 102 in the open and switch-on positions, the piston operated vacuum and air valve 42 can move over from left to right thereby opening the vacuum valve and closing the air valve thereof. At the same time, the main hyd raulic changeover valve 28 can move over from left to right to shut-off the second accumulator and to discharge the first accumulator into the main hyd raulic pipeline 9.

The vacuum and air valve 42 and the magnet and spring valve 102, when open to vacuum, will reduce the pressure within the accumulator tube 35 and above the main piston 36 to increase the pressure difference between the underside of main piston 36 and the topside of main piston 36. The aforementioncd pressure difference (being the absolute pres sura), on reaching the necessary absolute pressure difference, will cause the main piston 36 to rise in the accumulator tube 35 (the pressure difference in each case depending on the length of the piston).

With the main piston 36 in vertical transmit, the auxiliary valve 45, the relief valves 46 and 47 and the magnet and spring valve switch 48, can return to the closed and switch-off positions and a non-return inlet fluid valve 59 to the open position. At the same time, the non-return valve 79 can return to the closed position via the non-return valve 79 (which is connected by pipeline 81 to the inlet side of the main hydraulic change-over valve 28 and therethrough to connect by pipeline 83to the main hydraulic pipeline 9), when the main hydraulic change-over valve 28 is moved over from left to right, a pressurised fluid can discharge from the second accumulator into the main hydraulic pipeline 9.

On the first and second accumulators non-return valves are provided, 84 and 85, and 86 and 87 respectively which are connected from the auxiliary discharge valves 19 and 45 respectively by pipelines 23, 14, 13,24 and pipeline 53 on the first accumulator and by pipelines 31,49,43,30 and pipeline 29 on the second accumulator to the piston operated vacuum and air valves 6 and 42 and to the main hydraulic change-over valve 28. The non-return valves 84 and 85 on the first accumulator and the non-return valves 86 and 87 on the second accumulator are valves for locking, hydraulically, the vacuum and air valves 6 and 42 and the main change-over valve 28 when over to the right hand side or to the left hand side of their respective cylinders.The locked pressures are relieved by the main pistons 2 and 36 as they alternate between the bottom and top of the accumulator tubes 1 and 35 to work the valve arrangements thereat. The valve arrangements, when worked by the moving pistons 2 and 36, will allow the piston operate vacuum and air valves 6 and 42 and the main hydraulic change-over valve 28 to move over from left to right and from right to left in their cylinders automatically.

Non-return valves88 and 89 and 90 and 91, on the first and second accumulators are drain valves for lowering the main pistons 2 and 36 to 'wait' lines 92 and 93 and at the same time closing the auxiliary valves 3 and 37 and the relief valves 4 and 38.

Non return valves 94 and 95 are drain valves for drainingseepagefrom main piston topsides, if necessary and are connected by pipelines 96,97 and 98 on the first accumulator and by pipelines 99, 100 and 101 on the second accumulator to the main drain pipeline 16.

The non-return valves 88 and 89 and 90 and 91 are connected by drain pipes 172 and 173 on the first accumulator and by pipelines 174 and 175 on the second accumulator to the main drain pipeline 16, for drainage therefrom.

The lower section of the accumulator tubes 1 and 35 house magnets 105 and 106 which serve to increase the discharging force exerted by the main pistons 2 and 36.

On the first and second accumulators non-return valves 58 and 59 are connected by pipelines 60,61, 62, 63, 64 and through discharge valve 65 (Figure 4) and connecting pipe 66 to a supply pump 67. The supply pump 67 is connected by suction pipeline 68 to a suction valve 69 which is connected by pipeline 70 to a supply tank 71. As a precautionary measure, the length of discharge pipe 63 is extended to connect to a regulating valve 73 which is connected by pipeline 75 to supply tank 71 at inlet 76. To by-pass the supply pump 67, a pipeline 77 is connected between pipeline 70 and by-pass valve 72 which is connected to the discharge pipeline 63. The supply pump 67 is driven by a motor 76.

Referring now to Figure 3, the main hydraulic pipeline 9 is connected on its discharging end to a hydraulic turbine, the main pipeline 9 being supplied by the hydraulic accumulators shown in Figures 1 and 2. The accumulators, when in working state, will supply pressurised fluid into the main pipeline 9 and to discharge therefrom towards a hydraulic governor valve 111. The governor valve 111 is a working part of a hydraulic turbine, and is connected on the discharge side to a circular supply pipeline 112, by pipelines 113 and 114 and therefrom to discharge pressurised fluid through four pairs of short connecting pipes 115,116,117, and 118.The pressurised fluid passes through four pairs of nozzles 119, 120, 121 and 122, the nozzles being arranged on either side of rotor blading 123 of the main rotor 124 whereby, with pressurised fluid supplied to the above described system, the rotor blading 123 will revolve the rotor 124. Pressurised fluid which is exhausted from the rotor blading 123 will drain, and collect in turbine casing drain compartments 125 and 126 and cross connecting tube 127 (see lower part of Figure 3).

An extraction pump 128 is connected by a suction tube 129 to the drain compartments 125 and 126 and connecting tube 127. The extraction pump 128 is connected by a discharge pipeline 130 to the accumulator supplytank 71 (Figure 4) whereby, when the extraction pump rotates, fluid passes through the suction and dischargetubes 129 and 130 to the accumulator supply tank 71. The discharge pipeline 130 has a junction pipe 131 which is connected via a by-pass valve 132 and a pipeline 133 to the governor valve 111 (shown in detail in the upper part of Figure 4). The governor valve 111 is connected on the discharge side by pipelines 134 and 135 to a circular supply pipeline 136 connection to four pairs of short connecting pipes 137,138,139, and 140 which are connected to four pairs of medium pressure nozzles 172, 173, 174, and 175.

Both sets of high pressure and medium pressure nozzles are set at ninety degrees to each other, respectively, around and on either side of the rotor blading 123 of the main rotor 124 whereby, when the extraction pump 128 rotates, pressurised fluid will pass through the above described piping system and by-pass valve 132, discharging through the nozzles 172,173,174 and 175 to prime the rotor blading 123 of the main rotor 124.

The hydraulic system uses a centrifugally operated governor unit 141 which is connected by a lever 142 and an adjustable spindle 143 to the governor valve 111. A drive shaft is provided between the turbine rotor shaft and the governor unit 141 so that when the rotor shaft rotates, the drive shaft and the governor unit also rotate.

The governor valve 111 has a cylinder which is connected at either end by tubing 144, the tubing 144 being connectedto the turbine casing 145 so that when the main turbine is operating, pressure can be reduced on either side of the governor valve 111, thereby quickening the governor valve reaction to load conditions.

Number 146 designates a valve for supplying high pressure fluid from the main supply pipeline 9 through pipelines 147 and 148 to pass to machined grooves 149 on both sides of rotor hub 150. A seal of fluid in the hub grooves 149, when the hub 150 is rotated at high speed will react under centrifugal forces to press outwards between the main sides and the end cover faces of the rotor. The seal of fluid exhausting from the main rotor sides and end cover faces will disperse therefrom within the turbine casing 145.

A valve 151 is connected from the main supply pipeline 9 by pipeline 152 and 153 to a two stage air ejector 154 which is connected by an air pipe 155 to the turbine casing 145. The air ejector 154 is also connected by drain pipelines 156 and 157 to the turbine drain compartments 125 and 126 so that, upon the supply of pressurised fluid, the air ejector 154 will reduce the pressure within the turbine casing 145 to create a vacuum therein. Hydraulic pressure exhausted from the ejector 154 can drain-away therefrom through pipelines 156 and 157 and drain valves 158 and 159 to the turbine drain compartments 125 and 126.

A lubricating pump 160 has a suction pipe 161 which is connected to the lower section of a gearcase 162 to draw used lubricating oil therefrom. The lubricating pump 160 on its discharge side has a discharge pipeline 163 which is connected to the gearcase 162 and the main bearings by connecting pipes 164, 165, 166 and 167 so that when the lubricating oil pump 160 rotates the lubricating oil passes into the aforementioned parts.

A drain tank 168 is a tank for collecting displaced fluids which pass from the accumulator relief valves and non-return valves into the main drain pipeline 16. The main drain pipeline 16 is connected to a spring loaded regulating valve 169 and therethrough to the drain tank 168. The displaced fluid in the drain tank 168 will pass there from through a control valve 170 and through a connecting pipeline 171 to the turbine drain compartments 125 and 126.

A motor (185) driven forced draught fan 178 is connected by pipelines 182,183 and 184 (Figure 4) to the air valves of the piston operated vacuum and air valves 6 and 42 so that with the fan rotating and the air valves in the open position, pressurised air can pass therethrough into the tube spaces 186 and 187 above the main pistons 2 and 36 of the accumulators (Figures 1 and 2) thereby to increase the discharging forces of the main pistons 2 and 36.

A motor driven air pump 177 is connected by pipelines 103, 104 and 34 to the vacuum and spring valves 33 and 102 and by pipelines 103,179 and 180 to the vacuum valves of the piston operated vacuum and air valves 6 and 42 so that when automatically required, the air pump 177 can reduce the atmospheric pressure above the main pistons 2 and 36, enabling the pistons 2 and 36 to rise in the tubes 1 and 35.

The exhaust pipelines 188 and 189 and 190 are connected on the inlet sides to the vacuum and air valves 6 and 42 and on the outlet side. bo the main drain pipeline 16 so that with vacuum and air valves 6 and 42 in an operational state the exhaust fluids can automatically discharge into the main drain pipeline 16.

Important features of the accumulator-turbine system according to the invention, inter alia, are as fol lows:- (a) the linking together of first and second accumulators (e.g. as disclosed in Patent Specification No. 1,253,997) and a hydraulic turbine (e.g. as shown in the Specification No. 1,453,145) by means of relief valve 20,21 and 4 and the non-return valves 84 and 85 for the first accumulator and the relief valves 46,47 and 38 and the non-return valves 86 and 87 of the second accumulator to enable the slide valves 5,41 and 28 and the main pistons of the piston operated vacuum and air change-over valves 6 and 42 and the main change-over valve 28 to move from left to right and from right to left, by allowing displaced fluids to exhaust through their valve openings and to discharge into drain tank 168 and from there into the turbine drain compartments.

(b) Extraction pump 128 discharges part of its pressurised fluid through by-pass valve 132 via governorvalve 111 and a circular supply pipeline 136 to the turbine nozzles 172,173, 174 and 175 to prime the turbine blading 123 of the main rotor 124.

(c) The seal of fluid generated around the hub grooves 149 and 149a of the turbine rotor 124 and the end cover faces.

(d) The governor valve 111 has connections from the turbine casing 145 for reducing internal pressures on either side of the slide valve of the governor valve 111.

(e) The non-return valves 88,89,90 and 91 arranged to prevent flooding, above the free pistons 2 and 36, while suction is present in the accumulator tubes 1 and 35.

Figure 3a shows a diagram 191 which illustrates the positional angles of the rotor blading and the directional flow of pressurised fluid from the turbine nozzles. Reference 192 designates an angle of 112.5 , this being the angle of the rotor blading 193 to the circumferential centre line 194. Reference 195 designates an angle of 90" between a centre line 196 of the nozzle direction of pressurised fluid from the turbine nozzles and the working surfaces 193 of the rotor blading.

Referring now to Figure 6 of the drawings, reference numeral 201 designates a high pressure nozzle which is of angular design and is arranged to discharge high pressure fluid 214 towards rotor 203 and blades 204,205 and 206. At the same time, it draws in recirculating fluid 215 from pipeline 202. The pipeline 202 is of a larger diameter than the nozzle 201, thereby defining a fluid gap 216 around the nozzle 201. The recirculating fluid 215 is drawn from the turbine draining compartments, and is pumped out by extraction pump 128, which is driven by the turbine (see Figure 3).

When the high pressure fluid 214 is turned-on nozzle 201, and with the same high pressure fluid discharging towards the rotor blades 204, 205 and 206, a moving suction 217 will be created in fluid gap 216 and in pipeline 202. The same moving suction 217 draws in medium pressure drain fluid 215. As the pressure fluid 215 is drawn along pipeline 202, it will increase in pressure until it equates with the high pressure fluid 214 and discharges thereon to thrust on the working surfaces of the blades 204,205 and 206.

The rotor 203 is a rotor having blading arranged to have as many blades as possible under continuous pressure. The blades 204, 205 and 206 are placed across the peripheral surfaces with the outside blades 204 and 206 being of greater diameter than the centre blade 205. A space gap 218, situated above the centre blades 205, enables high pressure fluid 214 to reach as many blades as possible, between nozzles 212.

Reference 207, designates a reactionary ring which is arranged to encircle the outside of the blades. This encirclement should be as close in as possible.

References 208 and 208a designate the flanges of the reactionary ring 207. Reference 209 designates the outside casing cover which bolts onto the flanges 208 and 208a, and reference 210 designates the position of bolt holes. Reference 211 designates the position of a fixed blade which forms part of the reactionary ring 207, and by design is arranged to be located on the underside of reactionary ring 207. The fixed blade 211 is set over the centre blades 205, whereby with the high pressure fluid 214 turned on, the fixed blade 211 being a tapered blade will guide the fluid 214 onto the outside blades 204 and 206.

References 212 and 213 designate the position of nozzles 212, in this case eight in number, around the rotor 3.

The main feature of the rotor disclosed in Figure 6 is that the rotor 203 is designed to have as many blades as possible, under maximum pressure and at the same time, to be able to exhaust from both sides of the rotor into a a very high vacuum.

A second feature is in providing a dual purpose nozzle which, by virtue of its arrangement and its connection to the main and auxiliary pipelines on the one hand and to an extraction pump discharge pipeline on the other hand, can use up, by circulation, a proportion of the main and auxiliary drainage fluids from the turbines and thereby reduce the number of accumulator tubes required.

A third feature concerns the provision of two side disc plates which are arranged to be set around the sides of the revolving rotor blades 204,205 and 206.

The side disc plates are designed to adjust to and from the sides of the rotor 203 and the blades whereby, with the disc plates adjusted to the correct distance from the sides of the rotor 204 and the blading, and with the pressurised fluid turned on, a controlling back pressure can be built-up within the blading of the rotor 203. The same controlling back pressure provides another means of ensuring maximum hydraulic pressure on as many blades as possible, thereby reducing the number of accumulator tubes required even further.

Claims (5)

1. Aturbine rotor having apluralityofblades thereon, a nozzle system arranged to direct fluid towards the blades so as to expose as many of the blades as possible to maximum pressure, and an exhaust system arranged to exhaust fluid from both sides of the rotor into a high vacuum.

2. A rotor according to claim 1, in which the rotor is connected to main and auxiliary pipelines of an accumulator-turbine system, and also connected to an extraction pump discharge pipeline so as to use up, by circulation, a proportion of the main and auxiliary drainage fluids from the turbines and thereby reduce the number of accumulatortubes required.

3. A rotor according to claim 1 or 2, including a pair of side disc plates set around the sides of the revolving rotor blades, said side disc plates being adjustable relative to the sides of the rotor and the blades thereof whereby, upon adjustment of the side disc blades from the sides of the rotor and the blading thereof and with the pressurised fluid turned-on, a controlling back pressure can be built-up within the blading of the rotor.

4. A rotor according to claim 1 and substantially as hereinbefore described with reference to, and as shown in Figure 6 of the accompanying drawings.

5. An accumulator-turbine system including a rotor according to any one of the preceding claims.