U.S. patent number 3,879,949 [Application Number 05/424,758] was granted by the patent office on 1975-04-29 for two-phase engine.
This patent grant is currently assigned to Biphase Engines, Inc.. Invention is credited to David G. Elliott, Lance G. Hays.
United States Patent |
3,879,949 |
Hays , et al. |
April 29, 1975 |
Two-phase engine
Abstract
A two-phase power source comprises a rotor; a nozzle having an
outlet directed to discharge a two-phase jet for impingement on the
rotor to rotate same, the nozzle having means to subdivide flow
therein; and means to supply a heated first fluid in liquid state
to the nozzle for subdivided flow therein toward said outlet and to
supply a second and vaporizable fluid in liquid state to the nozzle
to receive heat from the first fluid therein causing the second
fluid to vaporize in the nozzle and mix with the first fluid in
essentially liquid state to produce said discharging jet.
Inventors: |
Hays; Lance G. (La Crescenta,
CA), Elliott; David G. (La Canada, CA) |
Assignee: |
Biphase Engines, Inc. (La
Crescenta, CA)
|
Family
ID: |
26977281 |
Appl.
No.: |
05/424,758 |
Filed: |
December 14, 1973 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
Issue Date |
|
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310210 |
Nov 29, 1972 |
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Current U.S.
Class: |
60/649; 415/89;
416/197R; 60/694; 415/202 |
Current CPC
Class: |
B01D
19/0052 (20130101); F01K 25/04 (20130101); F05B
2210/13 (20130101) |
Current International
Class: |
B01D
19/00 (20060101); F01K 25/00 (20060101); F01K
25/04 (20060101); F01k 025/06 () |
Field of
Search: |
;60/649,651,671,673,39.52,682,685,694 ;415/202 ;416/197 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Schwadron; Martin P.
Assistant Examiner: Ostrager; Allen M.
Attorney, Agent or Firm: Haefliger; William W.
Parent Case Text
This application is a continuation-in-part of our earlier
application Ser. No. 310,210, filed Nov. 29, 1972, now abandonned.
Claims
We claim:
1. In a two-phase power source, the combination comprising
a. a wheel providing a moving peripheral surface,
b. a nozzle having an outlet directed to discharge a two-phase jet
for tangential impingement on said surface to freely rotate the
wheel, the nozzle having means to subdivide flow therein,
c. means to supply a heated first fluid in liquid state to the
nozzle for subdivided flow therein toward said outlet and to supply
a second and vaporizable fluid in liquid state to the nozzle to
receive heat from the first fluid therein causing the second fluid
to vaporize in the nozzle and mix with the first fluid in
essentially liquid state to produce said discharging jet,
d. said surface enabling separation of the fluid gas and liquid
phases with low friction, transforming the flow momentum from a low
value at the nozzle exit to a high value in the liquid phase,
e. means to capture first fluid which has separated from the second
fluid and has acted to impart rotation to the wheel, with
essentially no power transfer to the wheel,
f. and means to convert the added momentum of the captured fluid to
mechanical or hydraulic power.
2. The combination of claim 1 including a second wheel having a
periphery extending in proximity with the periphery of the first
wheel whereby the two wheels define a gap therebetween to receive
the jet, and means supporting both wheels for simultaneous rotation
in response to tangential impingement of the jet on the wheel
peripheries defining said gap.
3. The combination of claim 1 wherein said periphery faces toward
the wheel axis.
4. The combination of claim 1 wherein said means to capture first
fluid comprises a diffuser, and including a fluid motor connected
to be driven by fluid captured by the diffuser.
5. The combination of claim 1 wherein the nozzle is defined by
parts that are relatively movable to vary the nozzle throat area
while enabling the pressure ratio, area ratio, exit velocity and
droplet trajectories to remain nearly constant.
6. In a two-phase power source, the combination comprising
a. separator and turbine rotors,
b. a nozzle having an outlet directed to discharge a two-phase jet
for impingement on the separator rotor to rotate same, the
separator rotor defining an annular zone for liquid retention,
and
c. means to supply a first fluid in liquid state to the nozzle for
flow therein to the outlet, and to supply a second fluid in the
form of hot products of combustion to the nozzle to mix with the
first fluid in essentially liquid state to produce said discharging
jet,
d. the turbine rotor having peripheral communication with said
zone.
7. The combination of claim 6 wherein said last named means
includes a combuster receiving compressed air and fuel for
combusting the fuel to produce said second fluid.
8. The combination of claim 6 including a load driven by the
turbine rotor.
9. In a two-phase power source, the combination comprising
a. a rotary separator,
b. a nozzle having an outlet directed to discharge a two-phase jet
for impingement on the rotary separator to rotate same freely, the
nozzle having means to subdivide flow therein,
c. means to supply a heated first fluid in liquid state to the
nozzle for subdivided flow therein toward said outlet and to supply
a second and vaporizable fluid in liquid state to the nozzle to
receive heat from the first fluid therein causing the second fluid
to vaporize in the nozzle and mix with the first fluid in
essentially liquid state to produce said discharging jet,
d. said rotary separator defining an annular zone in which first
fluid that acts to impart free rotation to the rotary separator is
centrifugally received,
e. a turbine rotor, and
f. means to recover liquid from said zone and deliver said liquid
to the turbine rotor.
10. The combination of claim 9 wherein the turbine rotor extends
coaxially with said rotary separator and defines generally radially
extending flow passage means for reception of said liquid.
11. The combination of claim 9 wherein the turbine rotor has
generally radially extending passages with peripheral inlets
rotating within an annular liquid receiving chamber defined by said
rotary separator and communicating with said zone.
12. The combination of claim 11 wherein said passages define
diffuser regions in which the velocity of the entering liquid is
partially converted to pressure.
13. The combination of claim 11 including means to return the
liquid received in said passages to the nozzle.
14. The combination of claim 12 including a casing for said rotary
separator and turbine rotor, and within which leakage liquid
collects in a casing drain zone, and including means on the rotary
separator movable through said drain zone for recovering the
collected liquid and for redirecting same back into the jet.
15. The combination of claim 11 including flow splitters on turbine
rotor extents proximate said passage inlets for dividing the flow
tending to impinge on said turbine rotor extents, whereby the
divided flow may travel relatively toward wake regions behind said
inlets.
16. The combination of claim 12 wherein the turbine rotor has
movable walls adjacent said diffuser regions for varying the areas
of said inlets.
17. The combination of claim 9 wherein said last named means
includes another nozzle to receive the first and second fluids with
the second fluid in vaporized and pressurized state, the second
fluid expanding to lesser pressure in said other nozzle, and a
vapor-liquid separator receiving the first and second fluid
discharging from said other nozzle for separating the expanded
vapor from the first fluid.
18. The combination of claim 17 wherein said means includes a first
path for first fluid recirculation from the separator to the first
nozzle and a second path for second fluid recirculation from the
separator to the first nozzle, a heater to heat first fluid flowing
in said first path and a diffuser to receive first fluid from the
separator and to recover kinetic energy thereof as pressure
sufficient to return the first fluid to the heater.
Description
BACKGROUND OF THE INVENTION
This invention relates generally to two-phase engines, and more
specifically concerns the use of a gaseous or vapor fluid to
accelerate a liquid to provide a mixture to drive a turbine or
hydraulic motor at shaft velocities much lower than required in
conventional gas or steam turbines, for the same power output.
There is a need for engines characterized by simplicity of
construction and operation, low weight in relation to power output,
low pollutant output in relation to conventional internal
combustion engines and high torque at engine speeds from zero to
the maximum design value. Gas and steam turbines do not meet all of
these criteria since their very high rotary speeds necessitate
relatively heavy speed-reducing mechanism or transmissions. While
proposals toward meeting these criteria have been made in the past,
none have embodied the many innovations of the present invention
which make possible the provision of a highly efficient engine.
SUMMARY OF THE INVENTION
It is a major aspect of the invention to provide a two-phase (gas
and liquid) engine capable of meeting all of the above
requirements, as well as overcoming other problems encountered in
this field. As will be seen, the engine is characterized by
relatively low weight and low pollutant emission per given power
output, and by output angular velocities that are much lower than
those characteristic of gas and steam turbines.
Basically, and in one of its forms, the invention is embodied in a
two-phase, power source that comprises a rotor; a nozzle having an
outlet directed to discharge a two-phase jet for impingement on the
rotor to rotate same; and means to supply a heated first fluid A in
liquid state to the nozzle for subdivided flow therein toward the
output and to supply a second and vaporizable fluid B in finely
divided liquid state to the nozzle to receive heat from the A fluid
causing the B fluid to vaporize in the nozzle and be expanded with
the A fluid which remains in essentially liquid state to produce
the discharging two-phase jet. Accordingly, no boiler or vaporizer
for the B fluid is required, there is improved mixing of vapor and
liquid in the nozzle, and the mass flow of the jet is sufficient to
permit operation of the rotor at much lower velocities than are
characteristic of gas and steam turbines. Also, heating of the A
fluid as by an external combustion heater prior to fluid
introduction to the nozzle permits achievement of low pollutant
level output.
Additional objects of the invention include the provision of a
first path to recirculate first fluid to the nozzle and in which
the motor is connected, and a second path to recirculate the second
fluid to the nozzle and containing a condenser; the provision of a
second nozzle to receive A and B fluids from the casing for the
rotor in such state that the second fluid expands further in the
second nozzle whereby the first fluid velocity is increased and the
second fluid may be separated in a gas-liquid separator; the
provision of a diffuser to receive the high velocity first fluid to
recover its kinetic energy as pressure sufficient to return the
first fluid to a heater, whereby a separate pump is eliminated; the
provision of a separator wheel and turbine wheel combination; and
the application of the invention to power a vehicle.
It is a further object of the invention to provide a two-phase
power source having first and second turbine rotors with separate
shafts and power take-offs, each rotor receiving impingement of a
two-phase jet from nozzle means as described; with pump means
driven at approximately constant speed by one rotor power take-off
for recirculating at least one of the A and B fluids to the nozzle
means, and other loads also driven at approximately constant speed
by the same rotor; and the other rotor power take-off being
operatively connectible to a variable speed load, as for example a
vehicle. A regenerative heat exchanger may be employed in this form
of the invention, as will be seen.
A still further object of the invention is to provide a rotary
separator acting as a gas-liquid separator, the rotary separator
periphery being essentially bladeless and receiving impingement of
the two-phase jet, and being free to rotate so that the velocity at
the periphery is essentially equal to the jet velocity, with a duct
or slit capturing liquid A which has impinged on the rotor for
supply to a diffuser wherein kinetic energy may be converted to
pressure in order to power a fluid motor, or otherwise cause liquid
to be circulated.
It is another object of the invention to provide a two-phase power
source characterized by supply to the nozzle of first fluid A in
liquid state, and second fluid B consisting of hot products of
combustion or compressed gas, the two fluids mixing in the inlet of
the nozzle to produce the two-phase jet, as will be described.
These and other objects and advantages of the invention, as well as
the details of illustrative embodiments will be more fully
understood from the following description and drawings, in
which:
DRAWING DESCRIPTION
FIG. 1 is a schematic diagram of one preferred embodiment of the
invention;
FIG. 1a is an elevation showing a vehicle powered by the power
apparatus of the invention;
FIG. 2 is a schematic diagram of another embodiment of the
invention;
FIG. 3 is a section through a turbine blade;
FIGS. 4 and 5 are schematic diagrams of further embodiments of the
invention;
FIGS. 6 and 7 are elevations showing two types of separators usable
in the invention;
FIG. 7a is a section on lines 7a--7a of FIG. 7;
FIGS. 8 and 9 are elevation and plan views respectively of a
two-phase nozzle;
FIG. 9a is a perspective view of nozzle injector structure;
FIG. 10 is a schematic of a segmented heat radiator;
FIG. 11 is a schematic of a further modification;
FIG. 12 is a side elevation of another form of a two-phase
engine;
FIG. 13 is an enlarged sectional elevation taken on lines 13--13 of
FIG. 16;
FIG. 14 is a fragmentary section on lines 14--14 of FIG. 13;
FIG. 15 is an enlarged section on lines 15--15 of FIG. 14;
FIG. 16 is a top plane view, partly in section, of the FIG. 12
engine;
FIG. 17 is a schematic fragmentary side elevation of a two-phase
turbine rotor;
FIG. 18 is a top plan view of the FIG. 17 rotor;
FIG. 19 is a schematic showing of jet impingement on the FIGS. 17
and 18 rotor, and of two-phase fluid separation therefrom; and
FIG. 20 is a diagram of power and torque characteristics for the
two-phase engine.
DETAILED DESCRIPTION
Referring first to FIG. 1, the two-phase power source or engine 10
includes a turbine rotor 11 rotatable about axis 12 to drive a
power take-off shaft 13, and having peripheral blades 14. A nozzle
15 has inlets 16 and 17, and an outlet 18 directed to discharge a
two-phase (gas and liquid) jet 19 for impingement on the blades to
rotate the rotor. Such a rotor may be used to drive a wheel 150 of
a vehicle 151 as seen in FIG. 1a, via a transmission 152, for
example, or directly via the power take-off shaft.
Means is provided to supply a heated first fluid in liquid state to
the nozzle inlet 16 for flow in the nozzle toward outlet 18, and to
supply a second and vaporizable fluid in liquid state to the nozzle
inlet 17 to receive heat from the first fluid causing the second
fluid to vaporize in the nozzle inlet. Such vaporization results
from intimate mixing of the second fluid, in liquid state, with the
first fluid at the nozzle inlet by means of an injector structure
as for example is shown in FIG. 8, 9 and 9a at 15. As there
illustrated, the injector structure comprises many small tubes 151
to subdivide and pass the fluid A entering the tubes via a plenum
chamber 152a in the nozzle passage. Note that the tubes are located
in the convergent portion 153 of the nozzle passage, the latter
also have a throat 154 and a divergent portion 155. A transverse
plate 158 in the passage supports the tubes at their entrances and
closes the spaces therebetween.
The second or B fluid is supplied via a plenum 156 to the cusps 157
formed between the tubes, for subdivided flow through the cusps
toward the nozzle throat, to intimately contact and mix with the A
fluid. Such vaporization produces even finer droplets, which
results in efficient coupling between the liquid droplets and the
vapor as the vapor is expanded in the nozzle to a lower pressure
and accelerated to a higher velocity at the nozzle exit, dragging
the first fluid to a similar higher velocity. The mixture then
inpinges on the rotor blades causing the turbine rotor to turn and
converting jet energy to shaft energy.
More specifically, such means includes a first path, (as for
example at 20) for first fluid recirculation to the nozzle from a
rotor casing or housing 21 wherein the first fluid collects in a
pool or annular film at 22 after separation from the rotor blades;
and a second path (as for example at 23) for second fluid
recirculation to the nozzle from the interior 24 of the housing 21.
A pump 25 and external combustion heater 26 may be connected in
series with the first path 20, as shown; and a condenser 27, pump
28 and control valve 29 may be connected in series with the second
path 23. The condenser operates to condense vaporized second fluid
removed from the housing interior 24, and the pump pressurizes and
circulates the condensed fluid for ultimate vaporization and
expansion in the nozzle at reduced pressure; accordingly, a very
compact system is achieved. With respect to the heater 26, heat may
be supplied from steady, low-pressure, low temperature combustion
of fuel, resulting in low exhaust emissions of harmful pollutants,
or from any other suitable heat source. The first fluid A may for
example consist of a hydraulic oil or heat transfer fluid and the
second fluid B may consist of water, or other vaporizable fluid,
fluid A having a lower vapor pressure than fluid B.
The system shown in FIG. 2 is similar in principle to FIG. 1,
excepting that the fluid supply means includes another nozzle 30
operating in series with the first nozzle and having inlets 30a and
30b communicating with the casing to receive the first and second
fluids from casing outlets 31 and 32 via lines 33 and 34,
respectively, for re-mixing. The second fluid, received by the
nozzle in vaporized and intermediately pressurized state (for
example around 35 psia) is expanded to low pressure (i.e., around
15 psia for example) and high velocity in the second nozzle 30. The
exit stream from the latter is passed at 36 to a vapor-liquid
separator 37 in which the vapor B is separated from the liquid A
and passed at 23a to condenser 27. Separator 37 may comprise a
surface inclined at an angle to the two-phase flow with a capture
slot, or it may be of the rotating type discussed below. The high
velocity liquid stream discharging from the separator is passed at
20b to a diffuser 38 where the kinetic energy of the liquid is
recovered as pressure sufficient to return the first fluid to the
heater 26. Accordingly, pump 25 is not needed, and system
complexity and cost are reduced. Instead of the separator, the
mixture exiting from the second nozzle may impinge on a second row
of blades on the same rotor resulting in an even lower rpm.
FIG. 3 illustrates a typical turbine blade 14 in section, with
concave curvature such as to separate the fluids A and B impinging
thereon as two-phase jet 19. Note that first fluid A separates as a
liquid film adherent to the blade concave surface 14a, whereas
second fluid B separates as gas flow indicated by arrows 140.
In FIG. 4, first and second rotors or turbines 40 and 41 have
suitable blades, as described previously, as well as power
take-offs such as shafts 42 and 43. First and second nozzles 44 and
45 have outlets 46 and 47 respectively directed to discharge
two-phase (gas and liquid) jets 48 and 49 for impingement on the
blades of the respective turbines to rotate them. Means is provided
to supply a heated first fluid A in liquid state to each nozzle for
flow therein toward the nozzle outlet, such means for example
including duct or path 50 containing an external combustion heater
51, for example, and communicating with nozzle end inlets 52 and
53. Means is also provided to supply a second and vaporizable fluid
B, as for example in liquid state, to each nozzle to receive heat
from the first fluid in the nozzle causing the second fluid to
expand in the nozzle and mix with the first fluid, which remains in
essentially liquid state, to produce the discharging jets. Such
means for example includes the duct or path 54 communicating with
the nozzle side inlets 55 and 56.
Turbine casings are shown at 57 and 58, and first fluid collects
therein and is withdrawn at 59 and 60 for return to path 50 via a
pump 61 driven by the power take-off of turbine 40. The turbine 40
and its power take-off are operated at constant speed, to provide
the most efficient operation of pump 61, a second pump 62 and any
other auxiliary equipment 63 such as an air conditioner, alternator
etc. The speed of turbine 40 is independent of the speed of turbine
41, enabling full flow and high torque over the entire range of
engine speed. The turbine 41 and its power take-off 43 are allowed
to vary in speed in accordance with the demands imposed by a
variable speed load 64, as for example a vehicle drive. Fluid A
flow control valves may be included at 66 and 67 in series with
path 50 to control the flow of liquid mass to the nozzles in order
to independently achieve the turbine velocities described. Another
method, discussed below, is to control the throat area of the
nozzle.
Also shown in FIG. 4 is a regenerative heat exchanger 70 having an
inlet 71 connected with the vapor outlets 72 and 73 from the
casings 57 and 58, as via paths 74 and 75. Second fluid leaves the
heat exchanger via outlet 76 connected with a condenser 77 wherein
second fluid is condensed as liquid and circulated at 78 to pump
62. The thus cooled and pressurized liquid is recirculated at 79 to
path 54 via the heat exchanger (see inlet 80 and outlet 81) to cool
the fluid vapor passing through the heat exchanger to the
condenser, for higher efficiency.
Referring to FIG. 5, the two-phase nozzle 15, heater 26 in path or
line 20 and valve 29, condenser 27 and pump 28 in path or line 23
are the same elements as in FIG. 1. The rotor is a rotary separator
in this form of the invention and comprises one or two wheels such
as indicated at 82 and supported by shafts 82a. The two-phase jet
19 is directed at the wheel peripheries 83 as shown, and
specifically to the gap 84 formed therebetween, whereby the wheel
peripheries or surfaces are driven at velocities matching the jet
velocity, to avoid excessive friction losses while separating the
liquid from the gas. The wheel or wheels act as separators in that
the vapor separates laterally as indicate by arrows 85, whereas the
liquid phase is captured by means such as a diffuser 86, the inlet
87 of which is in the direct path of liquid travel on the rotor
peripheries. No shaft power is obtained from the rotary separator.
Typically, for a 1,200 psia nozzle inlet pressure, between 3,000
and 4,000 psia can be recovered in the diffuser, wherein the
velocity head is converted to a pressure head. In FIG. 5 the high
pressure liquid flows from the diffuser at 91 to and through a
fluid motor 92 producing power at output shaft 93 due to the
pressure drop in the motor. Enough pressure remains in the fluid A
(liquid) discharging from the motor at 94 for return to the heater
26. The vapor consisting of fluid B and any fluid A carryover flows
at 95 from the casing 96 to the condenser 27, and is condensed,
pressurized at 28, and returned to the nozzle 15. FIG. 6 shows a
single rotary separator wheel 82, usable in the FIG. 5 device, with
a liquid A capture slot 97 with attached diffuser 98. FIGS. 7 and
7a show a modified rotary separator wheel 99 rotating on a shaft
100, and wherein the nozzle 15 is directed toward the inner
periphery 101 of a wheel rim 102. A layer 103 of liquid A forms on
that periphery, and a liquid capture slot 104 is located to receive
liquid for flow to a diffuser 105 operating in the manner of
diffuser 86 in FIG. 5.
In FIGS. 8 and 9, the nozzle 15 includes relatively movable body
parts 106 and 107. Part 106 is U-shaped in cross-section and
receives part 107, the latter being movable to increase or decrease
the flow area and in particualr the flow area at the nozzle throat
154 in order to keep the system temperature, pressure and nozzle
area ratio constant, while changing mass flow rate. An actuator rod
109 connected with part 107 is movable for this purpose. Part 107
includes a peripheral seal 160 sealing off against inner wall 161
of body part 106 defining recess 162. Note thrust bearing 163 to
receive endwise pressure exerted by part 107, and duct 165 through
part 107 to conduct flow pressure to the back side 166 of the
nozzle for equalization, facilitating control.
In FIG. 10 a modified condenser 27a usable in the above systems in
place of condenser 27 includes a vapor duct 110 receiving vapor
from the rotor casing, and discharging condensate at 111 for return
to the two-phase nozzle. Separate fluid coolant ducts 112 extend in
heat transfer relation with the duct 110, and a heat radiator 113
has segmented passages 114 in communication with the respective
separate ducts 112 as via heat pipes 115. This arrangement isolates
the radiator 113 from the vapor in the condenser in the event of
rupture or puncture of any radiator segment.
Referring to FIG. 11, the modified two-phase power source 120
includes a turbine rotor 121 rotatable to drive a power take-off
shaft 122. A nozzle 123 has inlets 124 and 125, and an outlet 126
directed to discharge a two-phase jet 127 for impingement on the
rotor to rotate same.
Means is provided to supply a first fluid A in liquid state to the
nozzle for flow therein toward the outlet. Such means may include a
liquid path 128 in which a pump 129 is connected to supply the
liquid (as for example hydraulic oil) to the nozzle. Means is also
provided to supply a second fluid in the form of hot products of
combustion or compressed gas to the nozzle to mix with the first
fluid in essentially liquid state to produce the discharging jet.
The latter means may for example include a steady state combustor
130 receiving compressed air at 131 as from an air compressor 132,
and also receiving fuel at 132a as from a pump 133 for combusting
the fuel to produce the second fluid at 134. In the nozzle the
temperature of the liquid A is raised, the temperature of the hot
products of combustion B is reduced, and the mixture is accelerated
to a relatively high velocity for doing work in the turbine rotor.
The latter, however, rotates at a much lower angular velocity than
a conventional gas turbine, for the same power output, so that a
much smaller speed reducing transmission may be employed. Further,
since the temperature of the combustion products is relatively low
after expansion through the nozzle, a lower than conventional
percentage of harmful polluting constituents is produced, and a
nearly isothermal expansion process is employed, increasing
efficiency.
A gas-liquid separator 140 is shown as connected with the turbine
discharge to receive the first and second fluid mix and to separate
the two fluids, the liquid A being recycled at 128 to the nozzle.
Fluid B may be discharged to atmosphere. A particularly effective
separator for FIG. 11 is one of the rotary separators discussed
previously.
FIGS. 12-16 show another design of a two-phase turbine engine,
including nozzles 167, separator wheel 168 rotating within casing
180, and radial-flow turbine 169, shown as coaxially rotatable
within the casing. The liquid and gas mixture comprising the
working fluid, as previously described, is supplied at high
pressure to the nozzle inlets 170. The mixture expands to low
pressure at the nozzle exits 171, and the resulting high-velocity
two-phase jets 172 impinge on the inner surface 173 of the rim 174
of the rotating separator at locations 175, seen in FIG. 16. The
liquid becomes concentrated in a layer 176 on the inner surface 173
due to the inertia of the liquid and to centrifugal force, while
the gas separates and flows radially inward through passages 177
and enters the gas discharge pipe 178 through ports 179 in the
stationary casing or housing 180. The rotating separator is
supported by bearings 181 mounted in the housing 180, and receiving
a separator wheel axle 168a.
The rotation of the separator 168 is impeded only by windage and
bearing friction losses which can be very small. Thus only a very
small relative velocity between the impinging jet 172 and the
surface 173, aided by the torque imparted to the rotating separator
by the inward flow of the gas through passages 177, serves to
maintain the speed of the liquid layer 176 at a value nearly equal
to that of the jets 172.
The liquid flows from the liquid layer 176 through passages 182 in
the rim of the rotating separator 168 and then into annular chamber
183 which forms an integral part of the separator wheel 168. As a
result another liquid layer 184 is formed, held against the surface
185 by centrifugal force. This layer furnishes the fluid energy
source for the turbine rotor 169 rotating concentrically within the
separator wheel and having turbine inlet passages 186 immersed in
the liquid layer 184.
The turbine 169 may have blades or passages arranged to intercept
the liquid layer 184, and FIGS. 13 and 14 show a radial-flow type
turbine. The turbine rotor 169 typically rotates at a lower angular
velocity than the separator wheel 168, causing liquid from the
layer 184 to enter the inlets 186, flow radially inward through
passages 187, and flow to liquid outlet pipe 188 via axial passage
187a in shaft 190 and apertures 189 in the wall of the turbine
shaft 190. The shaft 190 is connected to the load to be driven. The
turbine 169 is supported on bearings 191.
Each turbine passage 187 can optionally incorporate a diffuser 192
in which the velocity of the liquid entering inlet 186 can be
partially converted to pressure such that, even allowing for the
pressure drop in the radial passages 187 due to centrifugal force,
the liquid pressure in discharge pipe 188 is substantially higher
than the pressure in the turbine casing 180, and, in fact, greater
than the pressure at the nozzle inlets 170. Thus the diffusers 192
can supply the necessary pumping of the liquid, eliminating the
need for a separate pump to return the liquid to the nozzles.
For operation with high pressure at the discharge 188 the leakage
of liquid between the shaft 190 and the housing 180 is reduced by
labyrinth seals 193 and drains 194 which return liquid leakage to
the bottom 195 of the housing 180, where the liquid from this and
other internal leakage sources is picked up by slinger blades 196
and thrown back into the jets 172. Leakage to the outside of
housing 180 is prevented by a shaft seal 197.
The external shape of the turbine inlet ports 186 must be such as
to minimize external drag and turbulence that could disturb and
retard the liqid layer 184. The design shown in FIG. 15 employs a
wedge-shaped strut 198 for the portion of the turbine inlet which
intercepts the surface of the liquid layer 184 so that the flow
intercepted by the strut is split at 199 with minimum disturbance
and returned with little velocity loss to the liquid layer in the
wake region 200 behind the turbine inlet 186.
To allow for operation of the engine at different liquid flow rates
the passages 192 may be equipped with moveable walls 201 which
serve to vary the area of the turbine inlets 186.
Accordingly, the FIGS. 12-16 embodiment provide, essentially, a
moving surface to enable separation of the gas and liquid phases
with extremely low friction, said surface comprising a first wheel
having a periphery toward which the jet is tangentially directed,
which is free to rotate, and including means to capture first fluid
which has been separated from the second and has acted to impart
rotation to the wheel but with essentially no power transfer. Also,
they provide a second wheel having a periphery extending in
proximity with the periphery of the first wheel whereby the two
wheels define a gap therebetween to receive the separated first
fluid A and supply the fluid to the second wheel wherein the
kinetic energy of the fluid is converted partly to shaft power and
partly to pumping power.
FIGS. 17-19 illustrate a highly efficient turbine wheel 300 having
blades 301 to convert the kinetic energy of a two-phase jet into
power at shaft 302. As best seen in FIG. 19, each blade has a
generally straight first surface portion of portions 303 to receive
jet impingement, and inclined forwardly and transversely relative
to the forward direction of travel (indicated by arrow 305) of the
impinging jet 306 to effect separation of the first fluid in liquid
state from the second fluid and so that the separated liquid forms
a continuous film (as for example at 307) on the straight surface
portion. Thus, in the example, the first surface portion (or
portions) is inclined at a gradual angle .alpha. (10.degree. to
30.degree.) to the flow direction 305, so that film 307 may be
formed with minimum momentum loss.
The FIGS. 17-19 blade section also has a concavely (for example
circularly) curved second surface portion 308 merging with straight
surface portion 303 to receive the liquid film and to turn it
through a large angle to travel generally reversely relative to the
impinging direction, as seen at 307a, transferring momentum of the
flow to the rotor; further, the total rearwardly projected area
(indicated at 320) of the second surface portion is less than
one-half the projected area (indicated at 321) of the impinging
extent of the two-phase jet, for most efficient operation.
Referring again to the nozzle structure, as for example is seen in
FIG. 9, it provides very uniform initial sub-division and
distribution across the entire nozzle cross section of the
two-phases, either in gas and liquid states, or with both in the
liquid state. The nozzle contour minimizes the local velocity
difference between the gas and liquid at any point, for either
constant ratio of gas and liquid, or for varying ratios resulting
from vaporization or dissolutions of the different phases or
components, in order to minimize the energy dissipation due to
friction between the two phases.
FIG. 20 illustrates the fact that the engine variation of FIG. 4
produces a large torque when the output shaft is not rotating. This
highly desirable condition (as for vehicle use) may be achieved
with no auxiliary power supplies for the appurtenance equipment
employed to effect recirculation of the first and second fluids, as
is clear from the description.
Further, the means to supply heated first fluid in liquid state to
the nozzle may include another nozzle and rotor, or nozzle,
separator, and diffuser, communicating with the casing to receive
the first and second fluids therefrom, with the second fluid in the
vaporized and pressurized state, the second fluid expanding to
higher pressure in the first nozzle, retaining enthalpy for
expansion in the second nozzle, each nozzle operating with a lower
velocity to provide lower rotor velocity than would be possible
with a single nozzle and rotor. The second nozzle and rotor
combination may be followed by any number of other nozzle and rotor
combinations, the speed being proportional in the ideal case to the
one-half power of the number of nozzle-rotor combinations. All
rotors may be affixed to a common drive shaft producing a drive
shaft speed lower by the one-half power of the number of
combinations than would occur for a single stage.
Further, each fluid may be subdivided before introduction to the
first nozzle, with portions of each fluid being diverted to a
second nozzle in parallel to the first nozzle wherein they are
accelerated to produce power in a second rotor which rotates
independently of the first rotor to provide all parasitic power
requirements. This enables the first rotor to have a high torque at
zero shaft speed and enables the engine to operate in a self
sustaining fashion at zero shaft speed. The flows from both rotors
and rotor casings may be merged to form a single stream of the
first fluid, which is circulated through a heat exchanger, which
may receive heat from any suitable source, back to the nozzles, and
a single stream of the second fluid which is condensed and
circulated back to the nozzles.
* * * * *