Apparatus for supplying cooling water to the cooling channels of the rotors of electrical machines

Claim 2

Apparatus for supplying cooling water to the cooling channels of an electrical machine rotor having a rotor shaft, comprising an inlet chamber surrounding the rotor shaft in liquid-tight relation to the ambient, an outlet chamber communicating with the rotor channels for receiving the cooling water, the latter being heated and reduced in pressure by its passage through the rotor channels, said outlet chamber surrounding the rotor shaft in liquid-tight relation to the ambient, primary conveying means connected between said outlet chamber and said inlet chamber for conducting the water between said outlet chamber and said inlet chamber; pump means for supplying the cooling water to said inlet chamber under pressure and for urging the same through said primary conveying means; a leakage water chamber next to said outlet chamber in a direction toward the ambient, said leakage water chamber having a first contactless seal disposed with respect to the shaft where said leakage chamber adjoins the ambient and a second contactless seal where said leakage chamber adjoins said outlet chamber, said leakage chamber serving to collect cooling water which leaks through said second seal during normal operation, said cooling water being mixed with air leaking into said leakage-water chamber from the ambient, said pump means communicating with said leakage-water chamber for drawing the leakage cooling water from said leakage chamber, hydrogen gas supply means connected to said conveying means for saturating the cooling water conveyed by the latter with hydrogen, and an oxygen removal device for receiving the leakage water mixed with air, said device being connected between said leakage water chamber and said primary conveying means.

Claim 3

Apparatus according to claim 1, said pump means comprising a shaft pump mounted on one end portion of the rotor shaft so as to be rotatable therewith and said apparatus further comprising a stationary cooling water connection head surrounding said end portion of the shaft, said inlet chamber and said outlet chamber both constituting respective portions of said connection head, said rotor shaft having a central bore and an annular bore concentric with the latter, said central bore and said annular bore constituting respective portions of said primary conveying means, said connection head including a suction chamber connected ahead of said inlet chamber, said shaft pump being arranged with respect to said primary conveying means for pumping the cooling water from said suction chamber into said inlet chamber and then into said central bore, the cooling water flowing through said central bore in a direction opposite to the direction that the cooling water is pumped by said shaft pump; said connection head being arranged as an outer housing surrounding said end portion and said shaft pump; said inlet chamber, said suction chamber and said outlet chamber being within said housing and being arranged axially along said end portion one next to the other in the last recited order when viewed from the end of the shaft; a first separating wall disposed between said suction chamber and said outlet chamber, a first contactless shaft seal mounted on said separating wall, said leakage-water chamber being arranged within said housing after said outlet chamber in axial direction along said end portion, a second separating wall disposed between said outlet chamber and said leakage-water chamber, and a second contactless shaft seal mounted on said second separating wall.

Claim 4

Apparatus accOrding to claim 2, said primary conveying means comprising a flow path between said inlet chamber and said central bore, the latter communicating with the cooling channels of the rotor for directing the cooling water thereto, a stationary entrance stub located at the inlet of said central bore, a branch path connected into said flow path, a filter and a cooler connected into said branch path and loading the pressure side of said shaft pump, the output of said branch path being connected into said entrance stub, said entrance stub extending from the ambient through said inlet chamber in seal-tight relation to the latter.

Claim 5

Apparatus according to claim 1, each of said contactless shaft seals being configured as a labyrinth seal comprising a stationary part, and a rotating part separated from said stationary part by a radial distance of sufficient size to prevent rubbing therebetween which would otherwise occur because of radial and axial movements of the rotor.

Claim 6

Apparatus according to claim 4, one of said parts overlapping the other of said parts, said parts being axially displaced a sufficient distance to prevent rubbing therebetween which would otherwise occur because of radial and axial movements of the rotor.

Claim 7

Apparatus according to claim 1, comprising contact-making shaft seals for sealing said primary conveying means from the ambient to protect the rotor channels from the oxygen of air penetrating to the latter in the event of a fault.

Claim 8

Apparatus for supplying cooling water to the cooling channels of an electrical machine rotor having a rotor shaft, comprising an inlet chamber surrounding the rotor shaft in liquid-tight relation to the ambient, an outlet chamber communicating with the rotor channels for receiving the cooling water, the latter being heated and reduced in pressure by its passage through the rotor channels, said outlet chamber surrounding the rotor shaft in liquid-tight relation to the ambient, primary conveying means connected between said outlet chamber and said inlet chamber for conducting the water between said outlet chamber and said inlet chamber; pump means for supplying the cooling water to said inlet chamber under pressure and for urging the same through said primary conveying means; a leakage water chamber next to said outlet chamber in a direction toward the ambient, said leakage water chamber having a first contactless seal disposed with respect to the shaft where said leakage chamber adjoins the ambient and a second contactless seal where said leakage chamber adjoins said outlet chamber, said leakage chamber serving to collect cooling water which leaks through said second seal during normal operation, said cooling water being mixed with air leaking into said leakage-water chamber from the ambient, said pump means communicating with said leakage-water chamber for drawing the leakage cooling water from said leakage chamber, hydrogen gas supply means connected to said conveying means for saturating the cooling water conveyed by the latter with hydrogen, and an oxygen removal device for receiving the leakage water mixed with air, said oxygen removal device being connected between said leakage water chamber and said primary conveying means and having a palladium catalyzer which serves as a contact medium for causing a chemical reaction whereby the hydrogen and oxygen of the air combine to form water.

Claim 9

Apparatus for supplying cooling water to the cooling channels of an electrical machine rotor having a rotor shaft, comprising an inlet chamber surrounding the rotor shaft in liquid-tight relation to the ambient, an outlet chamber communicating with the rotor channels for receiving the cooling water, the latter being heated and reduced in pressure by its passage through the rotor channels, said outlet chamber surrounding the rotor shaft in liquid-tight relation to the ambient, primary conveying means connected between said outlet chamber and said inlet chamber for conducting the water between said outlet chamber and said inlet chamber; pump means for supplying the cooling water to said inlet chamber under pressure and for urging the same through said primary conveying means; a leakage water chamber next to said outlet chamber in a direction toward the ambient, said leakage water chamber having a first contactless seal disposed with respect to the shaft where said leakage chamber adjoins the ambient and a second contactless seal where said leakage chamber adjoins said outlet chamber, said leakage chamber serving to collect cooling water which leaks through said second seal during normal operation, said cooling water being mixed with air leaking into said leakage-water chamber from the ambient, said pump means communicating with said leakage-water chamber for drawing the leakage cooling water from said leakage chamber, hydrogen gas supply means connected to said conveying means for saturating the cooling water conveyed by the latter with hydrogen, and an oxygen removal device for receiving the leakage water mixed with air, said oxygen removal device being connected between said leakage water chamber and said primary conveying means and having a palladium catalyzer which serves as a contact medium for causing a chemical reaction whereby the hydrogen and oxygen of the air combine to form water.

Claim 10

An apparatus according to claim 7, control means connected in proximity with said hydrogen gas supply means and said oxygen removal device for maintaining a hydrogen surplus relative to the oxygen content in the water flowing to said oxygen removal device so as to keep the oxygen content flowing in said primary conveying means below an upper limit value.

Claim 11

An apparatus according to claim 8, said hydrogen gas supply means comprising a water storage configured as an expansion tank, and when containing water, said tank defining a gas space between its wall and the surface of the water contained therein, said gas space being a gAs pressure cushion when filled with gas, gas inlet means and gas outlet means communicating with said gas space at respective locations in the wall of said tank for supplying hydrogen gas flowing in a continuous stream through said gas space whereby the water becomes saturated with hydrogen gas.

Claim 12

An apparatus according to claim 9, a first conduit connecting said leakage-water chamber and said oxygen removal device, an ancillary conduit feeding into said first conduit from said water storage for supplying hydrogen saturated water to said oxygen removal device, said control means being disposed in said ancillary conduit for adjusting the flow of hydrogen saturated water to said oxygen removal device in accordance with the hydrogen surplus required for said chemical reaction in view of the composition of the leakage-water flowing from said leakage-water chamber.

Claim 13

An apparatus according to claim 9, comprising a rotor-water conduit connected between said outlet chamber and said water storage, a throttle valve arranged on said rotor-water conduit for adjusting the pressure PIII in said outlet chamber to prevent the occurrence of cavitation in the latter, said pressure PIII being taken with reference to the overpressure PG of the hydrogen gas in said water storage and being adjustable to a minimal value given by the empirically derived approximation formula: PIII about 6. Cube Root PG

Claim 14

An apparatus according to claim 11, said minimal pressure obtained with said formula being 3.5 kp/cm2 when PG 0.2 kg/cm2.

Claim 15

Apparatus according to claim 10, comprising gas exhaust means connected to said leakage-water chamber for drawing air through said first contactless seal into said leakage-water chamber in an amount sufficient to hold the hydrogen escaping from the leakage water to a concentration below the combustion concentration, and said control means being dimensioned to adjust the flow of hydrogen saturated water through said ancillary conduit in sufficient quantity to accommodate the increased oxygen concentration in the leakage water resulting from the presence of the air drawn by said gas exhaust means.

Claim 16

Apparatus according to claim 9, comprising a pressure-balancing chamber disposed between said outlet chamber and said leakage-water chamber, said pressure-balancing chamber defining respective interfaces with said leakage-water chamber and said outlet chamber and being fillable with cooling water at a pressure level lying between the pressure level of said outlet chamber and said leakage-water chamber, said interfaces having respective shaft-gaps, and a contactless shaft seal disposed at each of said shaft-gaps for sealing the latter.

Claim 17

Apparatus according to claim 14, comprising a gas evacuation chamber connected in front of said leakage-water chamber in the direction toward the ambient, the pressure level obtaining in said gas evacuation chamber being substantially the same as the pressure level in said leakage-water chamber, said gas evacuation chamber having an intermediate shaft seal between the same and said leakage-water chamber and having an end shaft seal for sealing the latter relative to the ambient, gas exhaust means connecting said gas evacuation chamber with the ambient for exhausting air from said evacuation chamber through said end shaft seal in such quantities that the hydrogen reaching the gas evacuation chamber from said leakage-water chamber through said intermediate shaft seal lies below the combustible gas concentration.

Claim 18

Apparatus according to claim 15, said intermediate shaft seal being configured at least partially as a water ring stuffing box seal.

Claim 19

Apparatus according to claim 15, said outlet chamber, said pressure-balancing chamber, said leakage-water chamber and said gas evacuation chamber being arranged axially one next to the other, and respective separating walls intermediate each two mutually adjacent ones of said axially arrAnged chambers, said separating walls having respective inner peripheries in surrounding relation to the rotor shaft, the respective seals at said inner peripheries having respective stationary parts said stationary parts being secured to said inner peripheries respectively.

Claim 20

Apparatus according to claim 14, wherein the region occupied by the water in said water storage defines a water space, said pressure-balancing chamber being connected to said water storage via a pressure-balancing conduit feeding into said water space.

Claim 21

Apparatus for supplying cooling water to the cooling channels of an electrical machine rotor having a rotor shaft, comprising an inlet chamber surrounding the rotor shaft in liquid-tight relation to the ambient, an outlet chamber communicating with the rotor channels for receiving the cooling water, the latter being heated and reduced in pressure by its passage through the rotor channels, said outlet chamber surrounding the rotor shaft in liquid-tight relation to the ambient, primary conveying means connected between said outlet chamber and said inlet chamber for conducting the water between said outlet chamber and said inlet chamber; pump means for supplying the cooling water to said inlet chamber under pressure and for urging the same through said primary conveying means; a leakage water chamber next to said outlet chamber in a direction toward the ambient, said leakage water chamber having a first contactless seal disposed with respect to the shaft where said leakage chamber adjoins the ambient and a second contactless seal where said leakage chamber adjoins said outlet chamber, said leakage chamber serving to collect cooling water which leaks through said second seal during normal operation, said cooling water being mixed with air leaking into said leakage-water chamber from the ambient, said pump means communicating with said leakage-water chamber for drawing the leakage cooling water from said leakage chamber, hydrogen gas supply means connected to said conveying means for saturating the cooling water conveyed by the latter with hydrogen, and an oxygen removal device for receiving the leakage water mixed with air, said device being connected between said leakage water chamber and said primary conveying means, a self-regulating feed-back pump, a water cooler connected to said feed-back pump, a down-comer conduit for connecting said feed-back pump after said leakage-water chamber, the pressure side of said feed-back pump being connected via a first flow resistance, on the one hand, to said down-comer line via a return conduit having a second flow resistance, on the other hand, to said primary conveying means via a forwarding conduit having a check valve, said oxygen removal device being connected into said forwarding conduit, said feedback pump having a back pressure referred to said check valve above the pressure drop produced by said feedback pump reduced by the pressure loss occurring up to said check valve, said feedback pump having an inlet pressure dependent upon the level of the water in said down-comer conduit, said feedback pump having a delivery head being controllable by said inlet pressure such that said feedback pump pumps only in a circulating path comprising said cooler and said return conduit when said water level is below a minimum height, whereas said feedback pump pumps an amount of cooling water into said primary conveying means when said inlet pressure exceeds said back pressure in response to an increase of said water level over said minimum height, said amount of cooling water corresponding to the pressure excess of said inlet pressure over said back pressure.

Claim 22

Apparatus for supplying cooling water to the cooling channels of an electrical machine rotor having a rotor shaft, comprising an inlet chamber surrounding the rotor shaft in liquid-tight relation to the ambient, an outlet chamber communicating with the rotor channels for receiving the cooling water, the latter being heated and reduced in pressure by its passage through the rotor channels, said outlet chamber surrounding the rotor shaft in liquid-tight relation to the ambient, primary conveying means connected between said outlet chamber and said inlet chamber for conducting the water between said outlet chamber and said inlet chamber; pump means for supplying the cooling water to said inlet chamber under pressure and for urging the same through said primary conveying means; a leakage water chamber next to said outlet chamber in a direction toward the ambient, said leakage water chamber having a first contactless seal disposed with respect to the shaft where said leakage chamber adjoins the ambient and a second contactless seal where said leakage chamber adjoins said outlet chamber, said leakage chamber serving to collect cooling water which leaks through said second seal during normal operation, said cooling water being mixed with air leaking into said leakage-water chamber from the ambient, said pump means communicating with said leakage-water chamber for drawing the leakage cooling water from said leakage chamber, hydrogen gas supply means connected to said conveying means for saturating the cooling water conveyed by the latter with hydrogen, and an oxygen removal device for receiving the leakage water mixed with air, said device being connected between said leakage water chamber and said primary conveying means, a self-regulating feed-back pump, a water cooler connected to said feed-back pump, a down-comer conduit for connecting said feed-back pump after said leakage-water chamber, the pressure side of said feed-back pump being connected via a first flow resistance, on the one hand, to said down-comer line via a return conduit having a second flow resistance, on the other hand, to said primary conveying means via a forwarding conduit having a check valve, said oxygen removal device being connected into said forwarding conduit, said feedback pump having a back pressure referred to said check valve above the pressure drop produced by said feedback pump reduced by the pressure loss occurring up to said check valve, said feedback pump having an inlet pressure dependent upon the level of the water in said down-comer conduit, said feedback pump having a delivery head being controllable by said inlet pressure such that said feedback pump pumps only in a circulating path comprising said cooler and said return conduit when said water level is below a minimum height, whereas said feedback pump pumps an amount of cooling water into said primary conveying means when said inlet pressure exceeds said back pressure in response to an increase of said water level over said minimum height, said amount of cooling water corresponding to the pressure excess of said inlet pressure over said back pressure.

Claim 23

Apparatus according to claim 19, said first flow resistance and said second flow resistance each being an adjustable control valve.

Claim 24

Apparatus according to claim 19, said hydrogen gas supply means comprising a water storage, and said primary conveying means comprising a rotor-water conduit connected between said outlet chamber and said water storaGe, said forwarding conduit being connected to said rotor-water conduit.

Claim 25

Apparatus according to claim 19, comprising a second feedback pump connected in parallel with said first mentioned feedback pump as a reserve pump, and an overflow assembly comprising a drain, an overflow pipe having a riser loop and emptying into said drain whereby said apparatus is protected against flooding should both of said feedback pumps fail, said overflow pipe having a U-shaped end portion and being connected to said down-comer conduit at a location below said leakage-water chamber, and sealing liquid column means arranged in said U-shaped end portion for sealing said overflow pipe under the non-failure condition of said feedback pumps, said column means being responsive to pressure occurring in the event of failure of both of said pumps such that said column means empties into said drain.