U.S. patent number 3,627,449 [Application Number 05/049,283] was granted by the patent office on 1971-12-14 for combustion pump--gas turbine system.
Invention is credited to Eric A. Salo.
United States Patent |
3,627,449 |
Salo |
December 14, 1971 |
COMBUSTION PUMP--GAS TURBINE SYSTEM
Abstract
A combustion pump system for the high pressure pumping of
liquids comprising a plurality of casings, a free piston slidably
disposed within each of said casings for reciprocal movement
between an upper combustion chamber and a lower hydraulic chamber
defined therein, a liquid input line connected to the hydraulic
chamber of each casing, each free piston being adapted to be raised
from its related hydraulic chamber toward its related combustion
chamber by admission of liquid into said hydraulic chamber through
the input line connected thereto, a liquid output line connected to
each hydraulic chamber, means for each casing to introduce a
fuel-air mixture into the combustion chamber of the casing and for
igniting the same therein to drive the free piston downwardly and
forcibly discharge liquid therebeneath from the hydraulic chamber
through said output line, said liquid output lines being
interconnected to form a single liquid discharge line, and control
means adapted to sequentially integrate the reciprocal movement
cycles of said free pistons to provide a substantially continuous
liquid output from said discharge line; Turbine rotor means
comprising a drive nozzle, said discharge line being in
communication with said nozzle to thereby drive said turbine rotor
means; and An exhaust line interconnecting each combustion chamber
with a gas turbine and adapted to convey the products of combustion
from each such combustion chamber to a gas discharge nozzle at said
gas turbine during the course of upward movement of the free piston
associated with said combustion chamber.
Inventors: |
Salo; Eric A. (San Lorenzo,
CA) |
Family
ID: |
21959024 |
Appl.
No.: |
05/049,283 |
Filed: |
June 24, 1970 |
Current U.S.
Class: |
417/73; 60/595;
60/39.181; 417/339 |
Current CPC
Class: |
F02B
75/04 (20130101); F04B 19/003 (20130101); F02B
71/06 (20130101); F03B 13/00 (20130101) |
Current International
Class: |
F04B
19/00 (20060101); F02B 71/06 (20060101); F02B
75/04 (20060101); F03B 13/00 (20060101); F02B
71/00 (20060101); F02B 75/00 (20060101); F04f
001/16 (); F04b 017/00 () |
Field of
Search: |
;417/73,74 ;60/13F,39.18
;417/339 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
Primary Examiner: Hart; Douglas
Assistant Examiner: Olsen; Warren
Parent Case Text
This application is a division of my copending application, Ser.
No. 773,000, filed Nov. 4, 1968, now U.S. Pat. No. 3,560,115 and
entitled THREE ELEMENT COMBINED ENERGY CYCLE.
Claims
What is claimed is:
1. In combination:
a combustion pump system having a multistaged discharge for the
pumping of liquids therefrom in accordance with predetermined
levels of pressure applying to such liquids, said system comprising
a plurality of casings, each having a liquid output line at each of
a plurality of liquid discharge stations, the output lines for each
group of corresponding discharge stations being interconnected to
form a single liquid discharge line for each such group of
stations, each of said casings having a free piston slidably
disposed therein for reciprocal movement between an upper
combustion chamber and a lower hydraulic chamber defined by said
casing, a liquid input line connected to each hydraulic chamber to
admit liquid into said chamber and thereby raise the free piston
therein towards its associated combustion chamber, said output
lines being connected to the hydraulic chambers, means for
introducing a fuel-air mixture into each combustion chamber and for
igniting the same therein to drive the piston downwardly and
discharge liquid from the hydraulic chamber, means including valve
means for the selective discharge of said liquids to first one of
said output lines and then the other of said output lines
responsive to the hydraulic pressure condition of said liquid, and
control means for sequentially integrating the reciprocal movement
cycles of said pistons to provide a substantially continuous liquid
output to each discharge line for each group of discharge
stations;
a plurality of turbine rotor means comprising drive nozzles, one
such turbine rotor means and nozzle being provided for each group
of discharge stations, the discharge line for each group of
discharge stations being connected to one of the nozzles to deliver
liquid therethrough and thereby drive the associated turbine rotor
means, said turbine rotor means being united to form a multistage
turbine rotor means through common output drive means; and
a gas turbine comprising a plurality of gas discharge nozzles to
drive the same, there being one such nozzle for each combustion
chamber, and an exhaust line for each combustion chamber
interconnecting the same with one of said gas discharge
nozzles.
2. A combustion pump and turbine combination for powering an
electric generator and the like comprising: at least one chamber
unit having a high pressure cylindrical casing containing a free
piston slidable therein; an hydraulic chamber defined by the bottom
of the free piston, the cylindrical casing, and a hemispherical
lower portion of the casing, wherein a liquid to be pumped is
admitted through an input line connected to said hydraulic chamber,
said liquid being supplied under pressure sufficient to
hydraulically raise the free piston; a combustion chamber defined
by the top of the free piston, the cylindrical casing, and a
hemispherical top portion of the casing, wherein a compressed
mixture of fuel and air is admitted and by ignition means ignited,
whereby the liquid is pumped at high pressure out a first output
line and thereafter at a lower pressure out a second output line
connected to said hydraulic chamber, said pumping being generated
by action of the forced descent of the free piston in the
cylindrical casing; a first turbine rotor means powered by liquid
discharge from the first output line until the pressure in said
hydraulic chamber reaches a lower, first terminal pressure; a
second turbine rotor means powered by liquid discharge from the
second output line at a pressure below the said first terminal
pressure until the pressure in the said hydraulic chamber reaches a
lower, second terminal pressure; a gas turbine powered by the
products of combustion which are exhausted from said unit when said
second terminal pressure is reached; valve means to selectively
control the pumping of liquid to power the respective turbine rotor
means, and valve means controlling the admission, combustion and
exhaust of the mixture of fuel and air and resulting combustion
products into and from the combustion chamber.
Description
BACKGROUND OF THE INVENTION
AS requirements for electrical power increase, new and different
means of powering electric generators are required to satisfy the
variety of conditions under which a plant must operate to produce
cheap electrical power. The system of the invention, when utilized
in combination with a generator provides a competitive means of
producing electrical power. Although the system may be employed for
other uses, its primary use is for the production of electrical
power.
Power plants of conventional design often have certain limitations
which curtail their efficiency under certain operating conditions.
Nuclear and other thermal plants have large water requirements for
cooling which necessitate location of the plants near large water
supplies. Conventional hydraulic plants also depend on a continuous
supply of water, and are further limited by the necessity of
locating plants where natural water heads occur. Additional
problems of atmospheric or thermal pollution affect a determination
of the plant design for a particular location.
SUMMARY OF THE INVENTION
The invention disclosed and claimed in my aforementioned copending
application, Ser. No. 773,000 in its basic form can most aptly be
described as a combustion pump. Fuel is principally converted to
hydraulic energy in the form of pumped fluid at extremely high
pressures. To raise the overall efficiency of the energy cycle the
combustion products are further utilized to drive a conventional
gas turbine. It is with this latter operation that the present
invention is particularly concerned.
The system, herein disclosed, has been adapted to power an electric
generator for which it is primarily suitable. A high pressure
cylindrical casing contains a piston which is freely slidable in an
inner cylindrical sleeve of the casing. A combustion chamber is
defined by the top of the free piston, the casing sleeve and a
hemispherical cylinder head. A mixture of fuel and air may be
compressed in the combustion chamber by a variety of conventional
methods. However, to attain the extremely high pressures desired in
the pump unit, a method similar to that employed in certain diesel
engines is preferred. With the piston at a top position, fuel and
air are simultaneously injected at high pressure into the
combustion chamber.
Below the free piston a hydraulic chamber is defined by the bottom
of the free piston, the casing sleeve and a hemispherical lower
portion of the casing. The free piston, which is mechanically
contained in the cylindrical casing only by action of the sides of
the piston against the casing sleeve, is raised to the top position
by admission of water from a conventional water supply. Once the
piston reaches the top dead position by the hydraulic lift from
admitted water, the supplied water is valved off.
With fuel and air injected, the unit commences its power stroke
when the gas mixture is ignited. The high pressure developed by the
combusted gases is transmitted through the piston by the downward
force exerted on the top of the piston to the water in the
hydraulic chamber. The high pressure water is bled through
discharge lines to a discharge nozzle which emits an extremely high
velocity water jet to an impulse-type hydraulic turbine. Although a
single hydraulic turbine may comprise the sole power output of the
combustion pump, the efficiency of the energy cycle may be raised
considerably by employing a three stage output.
As the water is discharged, the free piston descends in the
cylindrical casing. The descending piston permits the combustion
gases to expand in the enlarged combustion chamber thereby causing
an accompanying loss in pressure which is transmitted to the water
in the hydraulic chamber. Since hydraulic turbine design varies
according to the velocity and flow of the drive fluid to obtain an
efficient power output, it enhances the overall efficiency of the
combustion pump to employ two separate hydraulic turbines to
effectively handle the wide pressure range encountered during
operation of the pump. A first turbine is supplied by water at the
initial high pressures immediately subsequent to combustion. As the
pressure transmitted to the water drops to a selected terminal
pressure below which the first turbine would not be driven
efficiently, the supply to the first turbine ceases upon automatic
closing of a regulator valve and the supply to the second turbine
commences. This first terminal pressure may, for example, be 1,000
p.s.i.
Water is supplied to the second hydraulic turbine through a
discharge nozzle such as is utilized for the first turbine until
the velocity-flow relationship of the emitted jet no longer
efficiently drives the turbine. A second regulator valve terminates
the water supply at a related second terminal pressure of the water
in the hydraulic chamber which in the disclosed embodiment is
selected at 200 p.s.i. At the second terminal pressure, the water
contained in the hydraulic chamber has been substantially
discharged to either the first or second hydraulic turbines.
In accordance with the present invention, to additionally increase
the overall operating efficiency of the combustion pump, the
combustion products are exhausted to a gas turbine comprising a
third stage output for the cycle. The combustion products continue
to drive the gas turbine until expansion of the combustion products
nears completion. At an appropriate pressure slightly above
atmospheric pressure, water is again admitted to the hydraulic
chamber raising the free piston to the top dead position and
scavenging any remaining combustion products in the combustion
chamber. An exhaust valve automatically closes upon positioning the
piston at the top of its stroke and the combustion pump is again
ready to commence another cycle.
The two hydraulic turbines and the gas turbine may be appropriately
coupled together to drive an electric generator. Although a geared
coupling will in all likelihood be necessary to accommodate the
differing speeds of the turbines corresponding to their most
efficient operation, the turbines are schematically disclosed in
the drawings as directly coupled for simplicity of description.
To provide a relatively continuous output to each of the three
output stages, a plurality of individual units are integrated and
controlled by a central cam-operated timing device. For instance,
sequential coordination of three units would operate to supply the
discharge nozzle for a single first hydraulic turbine with high
pressure water from the second unit once the high pressure supply
from the first unit ceased. Sequentially, high pressure water from
the third unit would be supplied once pumped water from the second
unit ceased. Similarly, for the second hydraulic turbine and gas
turbine the respective fluids could be supplied in a substantially
continuous manner to thereby further increase the efficiency of a
power plant.
A power plant utilizing the subject system contains many advantages
over a plant utilizing either conventional reciprocal combustion
engines or conventional steam generators for driving steam
turbines. The system combustion pump contains far fewer moving
parts than a conventional reciprocal combustion and the system
combustion pump may be be continuously operated with far fewer
incident breakdowns than are encountered in continuous operation of
conventional reciprocal combustion engines. An additional
contributing factor to prolonging continuous operation is the low
cycle frequency which also enables use of cheaper fuels than those
necessary for high speed reciprocal combustion engines. The
free-piston design permits construction of large units not
attainable by the conventional reciprocal engines.
These large units are cost-competitive with the larger
steam-electric power equipment and yet have certain distinct
advantages over such equipment. Since steam is not utilized to a
significant extent in any of the three output stages in the subject
combustion pump, starting and stopping times are of very short
duration. In conventional steam power equipment, a substantial
amount of energy is lost in the change of state involved when
turbine steam is condensed, the loss corresponding to the latent
heat of steam. Such energy losses greater limit the overall
efficiency of steam power equipment.
The system combustion pump when employed in an electric power plant
has additional advantages over conventional steam power equipment
with which the invented device is particularly competitive. The
comparative low retention time of the combustion products in the
combustion pump inhibits the agglomeration of fuel minerals into
particulates of the light-scattering size range and minimizes the
formation of visible emissions, thereby resulting in less
objectionable emissions of products of combustion than in
conventional steam power plants. Also, thermal pollution, common in
conventional thermal or nuclear plants, is substantially reduced as
the water cooling requirements are only a fraction of the
requirements for conventional plants. This advantage also permits
location of the power plant utilizing combustion pumps to be
convenient to the load rather than to cooling water. It alternately
enables the subject power plant to be readily and cheaply
integrated into existing hydraulic generating stations to provide
fuel generator output during periods of curtailed water supply.
Since high temperature metallurgy problems are confined to the gas
turbine which contributes only a relatively small portion of the
total output of the combustion pump, manufacturing and maintenance
costs are drastically reduced. Use of hydraulic power as the prime
mover to operate the electric generator greatly reduces starting
warmup and permits practically instantaneous adjustment to load
changes over the full output range of the combustion pump. These
and other advantages will become apparent from a detailed
consideration of the drawings and accompanying specification.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic illustration of a three unit combustion
pump--turbine system constructed in accordance with the teachings
of the present invention powering an electric generator.
FIG. 2 is a sectional view of a typical pump unit in FIG. 1.
FIG. 3 is an enlarged partial section taken on lines 3--3 in FIG.
2.
FIG. 4 is an enlarged partial section of the throat and flow valve
shown in FIG. 2.
FIG. 5 is a sectional view taken on lines 5--5 in FIG. 2.
FIG. 6 is an enlarged partial view of the liner and outer casing
shown in FIG. 5.
FIG. 7 is a partial section showing the surface of the liner taken
along the lines 7--7 in FIG. 6.
FIG. 8 is an enlarged view of the discharge nozzle shown in FIG.
1.
FIG. 9 is a schematic illustration of the three unit pump and
timing control system.
FIG. 10 is a sequence chart illustrating the sequence of operations
for the three unit pump shown in FIG. 1.
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 illustrates a detailed schematic of the basic elements in a
three unit combustion pump arrangement incorporating the teachings
of the present invention for use in a power plant. The combined
chamber units, unit 1, unit 2 and unit 3, deliver a three-stage
output to a combination turbine 10 that is coupled to an electric
generator 12. The first stage output of the combined units is a
high velocity water discharge delivered to a first hydraulic
turbine 14. The second stage output is a lower velocity water
discharge delivered to a second hydraulic turbine 16, which may be
connected to the first hydraulic turbine 14 by a shaft 18. The two
hydraulic turbines 14 and 16 may be of the impulse type and each is
of conventional design for handling the respective velocity and
flow of water discharge for each output stage. The third stage
output comprises a gas discharge of the combustion products of the
three units. The gas discharge drives a gas turbine 20 coupled to
hydraulic turbines 14 and 16 by the common shaft 18. The combined
rotational output of the three turbines 14, 16 and 20 powers the
electric generator 12.
The three-stage output is developed by a novel combustion engine,
which is the subject of my copending application, Ser. No. 773,000,
and which operates most efficiently when three identical chamber
units are coupled in sequence to provide a continuous output at
each of the three output stages. For simplicity of description the
elements of each of the three identical units will be designated by
the same numerals on each unit.
As illustrated in FIG. 1, each chamber unit has a cylindrical
high-pressure casing 22 in which a free-floating piston 24 is
encased. The cylindrical casing is capped with a cylinder head 26
fastened to the cylindrical casing 22 by a peripheral series of
bolts extending through a flange 30 on the cylindrical casing and a
flange 32 on the cylinder head 26. At one side of the free-floating
piston is a combustion chamber 34 formed by the cylindrical casing
22, the cylinder head 26, and the free-floating piston 24.
At the opposite side of the free-floating piston 24 is a hydraulic
chamber 36 formed by the cylindrical casing 22, a hemispherical end
portion 38 of the cylindrical casing, and the free-floating piston
24.
Water is introduced to the hydraulic chamber through a water input
line 40 under a moderate pressure common to water supply lines. The
moderate pressure of introduced water rises the free-floating
piston 24 until the piston reaches an annular stop 42 formed by an
overlap of the cylinder 26 at the juncture of head 26 and casing
22, as shown in FIG. 2. The hydraulic raising of the free-floating
piston 24 scavenges residual combustion gases in combustion chamber
34, forcing the residual gases out exhaust discharge line 41.
The water surge produced by the sudden stoppage of the
free-floating piston 24 against the annular stop 42 releases a
spring-latched relief valve 44 in a hydraulic control line 46 shown
in FIG. 2. Water from input line 40 flows through hydraulic control
line 46 to a hydraulic actuator 48, FIG. 2, closing exhaust valve
50 in the combustion chamber 34. The hydraulic actuator 48
comprises a conventional arrangement of cylinder 52 and piston 54
hydraulically operated by control lines 46 and 56 connected to the
cylinder 52 at each side of the piston 54.
The lowered pressure sensed in exhaust manifold 58 by a pressure
sensing line 60 closes a pressure-operated valve 62 in the water
input line 40.
With the exhaust valve 50 closed and the free-floating piston 24 at
its raised position, the unit, typically unit 2 in FIG. 1, is set
for the combustion process. Simultaneously, air and liquid fuel are
injected at high pressures into the combustion chamber. Fuel from a
high pressure fuel line 64 is injected into the combustion chamber
through a fuel-injection nozzle 66 shown most clearly in FIGS. 2
and 3. The tip 68 of the fuel-injection nozzle 66 contains four
small holes 70 to disperse the discharged fuel in a fine spray. Air
from a high-pressure air supply line 72 is injected into the
combustion chamber 34 at a point adjacent fuel injection. To assist
in the full and uniform dispersion of the fuel, a cupola 74, FIGS.
2 and 3 is fixed to the cylinder head 26 in the combustion chamber
34. The cupola 74 has an opening 76 which is concentrically located
adjacent to the tip 68 of the fuel-injection nozzle 66, creating an
annular passage 78 for the air. Compressed air is injected into the
cupola 74 at orifice 80, entering the combustion chamber through
annular passage 78 and effectively mixing with the injected fuel
spray. After the charge of fuel and air is injected, the mixture is
ignited by an arcing spark between two electrodes 82 at the end of
high voltage leads 84 and 86.
The injection process continues for a timed interval and then
ceases when the fuel line 64 and air supply line 72 are valved off
by a timing control hereinafter discussed in detail. The ignited
gas mixture develops pressures in the combustion chamber greatly
exceeding 1,000 p.s.i. in the preferred embodiment. To accommodate
the high pressures and temperatures in the combustion chamber, the
inner wall of the high pressure cylinder head 26 is lined with a
deposit of porous or spongy metal. This porous metal liner 88, FIG.
2, is able to withstand the high temperatures attained in the
combustion chamber. The porous metal liner 88 will additionally
prevent excessive thermal stressing through the yielding
characteristics of the porous metal. The cylinder head 26 is of
hemispherical construction for the high strength advantages
inherent in such structural design. The free-floating piston 24
also contains a porous metal liner 90 on the surface exposed to the
combustion chamber 34. This liner 90 has the same advantageous
characteristics as the liner 88 in the cylinder head 26.
Since the cylindrical casing 22 is exposed to both the high
temperatures of the combustion chamber 34 and the low temperatures
of the hydraulic chamber 36 during each complete cycle of a unit's
operation, a special liner or sleeve is required to dissipate the
thermal stressing inherent from the thermal extremes encountered
during operation.
FIG. 5 illustrates the metallic liner 92 interposed between the
cylindrical casing 22 and the free-floating piston 24. The liner 92
is shown in greater detail in cross section in FIG. 6. The liner 92
contains a plurality of interconnected cooling water channels 94,
to which water is circulated by supply 96 and return line 98, both
shown in FIG. 2. The channels 94 run throughout the length of the
liner, whereby the circulated water maintains the cylindrical
casing at a reasonably low temperature. To further aid in cooling,
the liner 92 contains a series of thin slots 100 machined in to the
internal wall of the liner. The slots 100 are uniformly spaced
around the inner circumference of the liner 92. The slots are
staggered longitudinally in an adjacently overlapping manner as
shown in FIG. 7. This arrangement avoids continuous passageways in
bypassing relation to the free-floating piston which would permit
an excessive amount of water to enter the combustion chamber. Any
water which is trapped in the slots 100 and enters the combustion
chamber 34 as the free-floating piston descends will be vaporized
to cool the liner 92 and to add volume to the combustion gases
discharged to the gas engine.
Additionally, slots 102 are machined in the outer surface of the
liner 92. The slots 102 are slightly wider than the slots 100 on
the internal wall of the liner 92, and continuously run the entire
length of the liner 92 since no problem of water bypass is present
at the outer surface of the liner 92. The depth of the slots 102
extends slightly beyond the depth of the adjacent slots 100 on the
inner surface as shown in FIG. 6. The primary purpose of the
arrangement of slots 100 and 102 in the liner 92 is to provide a
means for transmitting the internal pressures of the combustion
pump units to the cylindrical casing 22 while preventing exposure
of the cylindrical casing 22 to the mechanical stressing generated
by changes in temperature during operation. The liner 92, which is
exposed to products of combustion and to radiation effects, as the
free-floating piston 24 descends during a power stroke, and to
subsequent quench effects as the free-floating piston 24 rises on
the scavenge part of the cycle, absorbs the mechanical stressing by
its ability to compress without changes in the liner's inner or
outer circumference.
Two piston guide tracks 104 are also machined at diametrically
opposed positions on the internal wall of the liner 92, as shown in
FIGS. 5 and 6. The guide tracks 104 run the length of the liner 92
and engage protruding arcuate guides 106 on the free-floating
piston 24, as shown in FIGS. 1, 2, and 5. The protruding arcuate
guides 106 provide stabilizing extensions on the free-floating
piston 24, preventing any occurrence of tilting or of rotation of
the piston 24 as it descends during the power stroke and rises
during the scavenging part of the cycle.
Returning to a detailed consideration of FIG. 2, the high pressures
developed during combustion are transmitted to the top of the
free-floating piston 24. The forces on the piston pressurize the
water in the hydraulic chamber such that hydraulic pressures
exceeding 1,000 p.s.i. are achieved. Regulator valve 108 is closed
to prevent the high pressure water from entering a small chamber
110 which is adapted to feed the second hydraulic turbine 16. The
regulator valve 108 is spring-operated, and by adjustment of the
compression of its spring 112 the hydraulic pressure required to
close the valve may be controlled. Adjustment is accomplished by
rotation of a hex-head 114 at the end of a valve stem 116. The
valve stem 116, which is threaded through an end bracket 118 at the
base of the pump unit, has a small circular plate 121 fixed to it
and has a small circular plate 123 freely sliding on it, between
which plates the spring 112 is compressed. The pressurized water in
hydraulic chamber 36 is pumped through a conventional check valve
120 in a high pressure output line 122 to a fluid directing outlet
which may be in the form of a specially designed discharge nozzle
124 shown in FIG. 8, and which forms the subject matter of the
copending application, Ser. No. 49,383, filed June 24, 1970. The
high pressure output line 122 for each of the three units is
connected to a single discharge line 126 feeding the discharge
nozzle 124. The velocity of the jet of water emitted from the
discharge nozzle 124 is regulated to a relatively constant value by
a needle valve 128, slidably mounted in the hollow nozzle portion
of the discharge nozzle 124 and directed out a convergent jet
orifice 130. Positioning of the needle valve 128 is responsive to
the pressure in the discharge line 126.
A hydraulic regulator 132 for the needle valve 128 comprises a
piston 134 connected to the distal end of the needle valve 128
contained in a cylinder 136. The piston 134 is actuated in one
direction to remove the needle valve 128 away from the orifice 130
of the discharge nozzle 124 by the hydraulic pressure in the
discharge line 126, which line is connected to the cylinder 136 by
a small hydraulic line 138. The degree of actuation is controlled
by a compression spring 140 which is maintained in position by the
outer wall of the hydraulic regulator and the face of an adjustment
screw 142 on a threaded portion of the needle valve 128. As the
pressure in the discharge line 126 drops, the force of the
compression spring overcomes the hydraulic force on the piston 134
to gradually close the needle valve 128. Although the flow of the
emitted jet of water from the discharge nozzle 124 is reduced, the
velocity is maintained relatively constant until a terminal
pressure is reached at which point the needle valve 128 is fully
closed and the discharge stopped. The terminal pressure can be
controlled by selection of a suitable compression spring and by
proper positioning of the adjustment screw 142 on the threaded
portion 144 of the needle valve 128.
In the preferred embodiment herein disclosed, the first stage
terminal pressure may be, for example, 1,000 p.s.i. As this first
stage output is supplied by the high pressure output of the three
units delivered in sequential fashion, the emitted jet of water
from the single high velocity discharge nozzle 124 will be
continuous, varying only in the degree of flow discharged to the
first hydraulic turbine in FIG. 1 the nozzle 124 being a variable
flow--constant velocity type as described above.
As the combustion gases expand when the free-floating piston 24
descends to pump water to the high pressure nozzle 124, the
hydraulic pressure in the hydraulic chamber also reaches a first
terminal pressure, here again selected at 1,000 p.s.i. At 1,000
p.s.i., the spring-loaded regulator valve 108, FIG. 2, opens to
permit the water to be pumped to the small chamber 110 below the
regulator valve 108 and then to lower pressure output line 146. As
previously noted, once the pressure for a particular unit drops
below 1,000 p.s.i., the high pressure discharge nozzle 124 either
closes to prevent further flow from that particular unit or
continues to remain open if sequentially it is being supplied by
the next following unit. In the latter case, check valve 120 not
only prevents backflow but also prevents further discharge from the
particular unit in which the pressure has dropped below the first
terminal pressure.
The lower pressure output line 146 for each of the three units is
connected to a single lower pressure discharge line 148 feeding a
lower pressure discharge nozzle 150, FIG. 1, which is substantially
identical to the nozzle shown in FIG. 8. To obtain a second
terminal pressure setting, which may be, for example, 200 p.s.i.,
the lower pressure discharge nozzle 150 need differ only in the use
of a compression spring which will permit operation of the
discharge nozzle in the 1,000 -- 200 p.s.i. range. Once a
particular unit reaches the second terminal pressure of 200 p.s.i.
the discharge nozzle will close unless it has begun to discharge
water supplied from the next following unit in sequential
operation. Once the next following unit commences its lower
pressure pumping, the back flow to the preceding unit will
hydraulically close a specially designed flow-operated valve 152
shown in FIGS. 2 and 4.
The flow-operated valve 152 comprises a cylindrical sleeve 154
seated on a shoulder formed in the end portion of the pump unit.
This sleeve has four ascending helically arranged slots 160 such
that the lower terminal portion of one slot commences at a point
directly below the upper beginning portion of the adjacent slot.
Two spring-loaded ball pins 162, which may be of the type commonly
employed in socket wrenches, are mounted in the valve throat 164 so
that they freely extend into two opposed slots 160 in the sleeve
154. Two opposed vanes 166 are disposed at an angle on the inner
surface of the sleeve 154.
Backflow from the lower pressure output line exerts upward and
lateral forces against the vanes 166 to cause the sleeve 154 to
turn and ride up the ball pins 162 until the top of the sleeve 154
contacts the bottom of the poppet 168 of the regulator valve 108.
In this position the ball pins 162 are located at the lower
terminal portions of their respective slots 160. The flow-operated
valve 152 in essence operates as a check valve. The sleeve remains
in this closed position until the combustion process in the
following cycle raises the hydraulic pressure in the hydraulic
chamber 36 to a point exceeding 1,000 p.s.i., whereupon the
spring-loaded regulator valve 108 is forced down by action of the
hydraulic pressure on the poppet 168 over coming the oppositely
directed force of spring 112. The downward movement of the
regulator valve 108 also forces the flow-operated valve 152 down to
its seating shoulder 156. The spring-loaded ball pins 162 are
forced to retract until the sleeve is seated, at which point they
extend into the upper beginning portions of their respective slots
160.
When the second terminal pressure is reached, a spring-loaded
control valve 169, FIG. 2, opens to permit water to flow through
control line 56 to the hydraulic actuator 48 to open exhaust valve
50. The combustion products which at their lowest pressure are at
the second terminal pressure value expand into the exhaust
discharge line 41 and are emitted from a separate gas discharge
nozzle 171 for each unit to a single gas turbine 20. Again, the
sequentially integrated cycles of the three units provide a
substantially continuous driving force to, in this instance, the
gas turbine.
Just prior to the reaching of the second terminal pressure value in
the hydraulic chamber, the downward moving free-floating piston 24
will be approaching the bottom of its stroke. To dissipate the
momentum of the descending piston, an arresting device, as
illustrated in FIG. 2 has been included. The bottom of the
free-floating piston 26 carries a trotuberance 170 which has
integral therewith plunger 172. The plunger 172 fits closely but
slidably within a centrally located bore 174 of an arresting boss
176 connected to the cylindrical casing by yoke member 178 which
permits water to freely pass to the lower part 36a of the hydraulic
chamber 36. Four tapered channels 180 are longitudinally machined
in the plunger 172, as shown in FIGS. 2 and 5. When the piston 24
descends, the plunger 172 projects into the bore 174 forcing the
trapped water therein upwardly through the tapered channels 180.
The hydraulic pressure of the trapped water increases rapidly as
the effective area of the channels 180 decreases to the discharge
of water. The increasing hydraulic pressure opposes piston momentum
to hydraulically snub the piston downstroke and bring the piston to
a full stop without severe impact of the plunger 172 with the
bottom 174a of the bore 174. A small drain opening 182 is drilled
through the bottom 174a of the bore 174 to provide a flow of water
at the end of each stroke and in this manner keep debris and
sediment flowing out of the bore 174.
Sequential operation of the three pumping units is controlled by
the timing device and fuel-air regulator shown in FIG. 9. Fuel from
a reservoir 184 is pumped at high pressure by a hydraulic pump 186
located in a fuel supply line 188 for the three units. The fuel
supply line 188 branches into individual feeder lines 190a, b, and
c, for each of the units. Pressure-operated flow regulator valves
192a, b, and c, are included in each of the feeder lines 190 to
control the amount of fuel supplied during each cycle of a unit.
Air is supplied from an air cylinder 194 which is pumped to a high
pressure by a compressor 196. An air supply line 198 branches into
three feeder lines 200 a, b, and c, which are individually
controlled by flow regulator valves 202 a, b and c. The flow
control valves 192 and 202 for fuel and air supply to the units are
operated by pneumatic pressure from a control cylinder 204.
Pressure in the control cylinder which regulates the degree of flow
in each of the flow regulator valves 192 and 202 is regulated by a
master control lever 206. The master control lever 206 is variably
positionable by a detent rack 208, and, by rotation of a cam 210
asymmetrically pivoted on a pivot pin 212, will vary the
compressive force of a spring 214. The spring 214 engages a pivot
link 216 which swingably responds to the cam action of the master
control lever 206. The opposite end of the spring 214 is connected
to a pressure control valve 218. An offsetting force developed by a
feedback pressure from bleeder line 222 running from control
cylinder 204 to a control diaphragm 224 regulates the pressure
control valve so that the desired pressure is maintained in the
control cylinder 204 by a compressor 226.
Sequential timing is regulated by a rotating distributor cam 228
which is gear-driven by motor 232. Equidistantly positioned around
the periphery of the distributor cam 228 are three piston-operated
air valves 234 a, b and c. Considering exemplar air valve 234c in
detail, a pivotally mounted cam follower 236 is linked to the
piston 238 in the air valve 234c. When the raised portion 240 of
the distributor cam 228 engages the cam follower 236, which is held
against the distributor cam 228 by a compression spring 242, the
valve piston 238 is depressed to permit compressed air to flow from
the control cylinder 204 to the pressure operated flow regulator
valves 192c and 202c and controls the supply of fuel and air, in
this instance, to unit 3. The rate of air and fuel supplied to unit
3 is regulated by the selected pressure in the control cylinder 204
which is transmitted to the flow regulator valves 192 and 202c.
Once the raised portion 240 of the distributor cam passes,
injection of fuel and air to the combustion chamber of the
particular unit ceases. Each of the other two piston-operated air
valves, 234a and b, operates in an identical manner to actuate and
regulate the flow regulation valves 192a and b, and 202c and b for
units 1 and 2, respectively.
After a charge of fuel and air has been injected into the
combustion chamber, during engagement of the raised portion 240 of
the distributor cam 228 with the cam follower 236, the raised
portion 240 of the cam 228 then engages and closes a set of
spring-loaded ignition points 246 to ignite the injected charge. A
high voltage potential is connected through the set of ignition
points 246 to the electrodes 82, FIG. 2, by high voltage lead 84.
As the distributor cam rotates, each unit is fueled and fired in
timed sequence in like manner.
The sequential operation of the three unit pump system is shown in
FIG. 10. First considering unit 1, remaining combustion gases are
scavenged by the rising piston in the scavenge step. The charge is
fired on closure of the set of ignition points by the distributor
cam to raise the pressure of the water in the hydraulic chamber and
pump water to the high pressure turbine in first stage output. The
duration of high pressure pumping may be controlled by variation in
the amount of injected fuel and air, or by variation in the
velocity-flow relationship of water emitted from the high pressure
discharge nozzle. As the free-floating piston descends in the
cylinder casing, there is a resultant expansion of the gases.
During this procedure, a first terminal pressure is reached, at
which point pumping to the high pressure turbine ceases and pumping
to the low pressure turbine commences in second stage output.
Duration of second stage output may be also controlled by variation
in the amount of initially injected fuel and air, or by variation
in the velocity-flow relationship of water emitted from the low
pressure discharge nozzle. As the water level decreases with an
accompanying drop in pressure, a second terminal pressure is
reached, at which point pumping to the low pressure turbine ceases
and the exhaust valve is opened to deliver the combustion products
to the gas turbine for third stage output. When the combustion
products have been delivered for the most part to the gas turbine,
the scavenging step is again initiated.
The steps for unit 2 are identical, with timed injection of fuel
and air commencing immediately after the scavenging step. Unit 3
follows in a similar manner, whereupon, on completion of the
scavenging step, unit 1 is again ready to commence fuel and air
injection. The sequential operation of the three combined units
delivers a substantially continuous output to each of the three
turbines powering the generator.
* * * * *