U.S. patent number 3,648,458 [Application Number 05/058,934] was granted by the patent office on 1972-03-14 for vapor pressurized hydrostatic drive.
Invention is credited to Roy E. McAlister.
United States Patent |
3,648,458 |
McAlister |
March 14, 1972 |
VAPOR PRESSURIZED HYDROSTATIC DRIVE
Abstract
A hydrostatic drive system generally of the type wherein vapor
is alternately directed into one of two reservoir tanks so that
working fluid in that tank is forced out of the tank by pressure of
the vapor and through a fluidic motor to generate a mechanical
output before it returns to refill the other tank. When the first
tank is substantially depleted, the vapor pressure is directed into
the refilled tank so that fluid from that tank now flows through
the motor to refill the first, now depleted, tank. In one
embodiment, cyclic pressure generated by a vapor generator forces
fluid cyclically through an AC fluid motor. In another embodiment,
heat from the working fluid is employed to generate the vapor
pressure and reduce the temperature of the working fluid passing
through the motor. In a further embodiment, the fuel serves as the
working fluid and the vapor from the refilling tank is combusted to
provide heat to convert the fuel from its liquid to vapor state. In
another embodiment, the combustion gases are combined with the
vapor so that, when water is the working fluid, the water vapor in
the combustion gases serves as make up working fluid. In a further
embodiment, heat from working fluid on its way to the motor is
transferred to other working fluid in a second system to drive a
second motor. Further aspects of the invention are set forth
below.
Inventors: |
McAlister; Roy E. (Phoenix,
AZ) |
Family
ID: |
22019817 |
Appl.
No.: |
05/058,934 |
Filed: |
July 28, 1970 |
Current U.S.
Class: |
60/415; 60/371;
60/375; 60/486; 91/4R |
Current CPC
Class: |
F04B
45/0536 (20130101); F16H 43/00 (20130101); F03B
17/005 (20130101) |
Current International
Class: |
F16H
43/00 (20060101); F04B 45/00 (20060101); F04B
45/053 (20060101); F03B 17/00 (20060101); F15b
015/18 (); F15b 013/042 () |
Field of
Search: |
;91/5 ;60/51 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Geoghegan; Edgar W.
Assistant Examiner: Ostrager; Allen M.
Claims
What is claimed is:
1. An energy conversion system comprising:
first means for containing a working fluid, second means for
containing a working fluid, motor means operatively communicating
with said working fluid in said first and second containing means
for receiving said working fluid so that said working fluid flows
into and out of at least a portion of said motor means so as to
generate a mechanical motion,
means for alternately supplying a given fluid in a vapor phase to
said first means at a pressure such that said working fluid is
forced from said first means, into and out of said portion of said
motor means and into said second means and to said second means at
a pressure such that said working fluid is forced from said second
means, into and out of said portion of said motor means and into
said first means,
means for receiving said fluid in a liquid phase and for heating
said fluid in said liquid phase to convert it to said given fluid
in said vapor phase, and
means for receiving a portion of said working fluid forced from
said first and second means and injecting said portion in fine
droplets into said receiving and heating means.
2. A system as in claim 1 wherein said motor means is a DC fluid
motor.
3. A system as in claim 1 wherein said motor means is an AC fluid
motor.
4. A system as in claim 1 further including first check valve means
connecting said first means to the entrance of said portion of said
motor means for permitting fluid to flow from said first means
toward said motor means and for preventing flow from said motor
means toward said first means, second check valve means connecting
said second means to the entrance of said portion of said motor
means for permitting fluid to flow from said second means to said
motor means and for preventing flow from said motor means toward
said second means, third check valve means connecting the exit of
said portion of said motor means to said first means for permitting
fluid to flow from said exit to said first means when said given
fluid in said vapor phase is being supplied to said second means
and for preventing flow from said first means to said exit and
fourth check valve means connecting said exit to said second means
for permitting fluid to flow from said exit to said second means
when said given fluid in said vapor phase is being supplied to said
first means and for preventing flow from said second means to said
exit.
5. A system as in claim 1 wherein said first and second means are
tanks and said receiving and heating means includes means for
combusting a fuel and means for supplying said fuel to said
combusting means.
6. A system as in claim 1 wherein said receiving and injecting
means includes a vessel having walls adapted for harmonic
resonance, an inlet for receiving said portion of said working
fluid and an outlet connected to said receiving and heating means
and means for harmonically resonating said walls to inject said
fluid into said receiving and heating means as fine droplets.
7. A system as in claim 1 wherein said receiving and injecting
means includes a liquid horn having a large inlet for receiving
said portion of said working fluid and a small outlet connected to
said receiving and heating means and tuning fork means mounted
adjacent said inlet for causing said horn to inject said droplets
into said receiving and heating means.
8. A system as in claim 1 wherein said first and second means are
each reservoir tanks and wherein each said tank includes a thin
walled quench tube having a plurality of apertures and mounted
within that tank for receiving said working forced into said tanks
so as to prevent thermal shock to the walls of that tank.
9. A system as in claim 1 further including means for venting said
first means to the atmosphere while said supplying means is
supplying said given fluid in said vapor phase to said second means
and for venting said second means to the atmosphere while said
supplying means is supplying said given fluid in said vapor phase
to said first means.
Description
BRIEF DESCRIPTION OF THE PRIOR ART AND
SUMMARY OF THE INVENTION
The invention relation to a vapor pressurized hydrostatic drive for
converting heat into mechanical motion.
Over the past few centuries, one of the continuing goals of
technology has been the improvement of systems for converting
energy in the form of heat into mechanical motion. The widely
employed conventional steam engine and internal combustion engine
are the products of this continued effort. Neither of these engines
is, however, completely satisfactory. Both are complicated heavy
machines whose efficiency in accomplishing the energy conversion is
normally quite low. The internal combustion engine produces
pollutants which are both dangerous and obnoxious.
One promising heat conversion apparatus which has been developed
includes a tank containing a working fluid and a fluid motor
operatively connected to the tank so that when heat is added to the
system a pressure is generated on the fluid in the tank which
forces it out the tank and through the motor, thus generating a
mechanical output. A second tank can be added to the system so that
the fluid after passage through the motor can refill that tank.
When the second tank is full, pressure can be generated on the
fluid in that tank to force fluid flow out of the second and
through the motor to refill the first. Such systems are shown, for
example, in Pike U.S. Pat. Nos. 228,555 and Parish 2,941,608.
The present invention relates to a number of embodiments basically
similar to such devices. In these embodiments, the basic engine is
improved to increase its efficiency and make it more satisfactory
for use as an energy conversion system.
Many other objects and purposes of the invention will become clear
from the following detailed description of the drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows a first embodiment of the invention with a DC fluid
motor,
FIG. 2 shows a further embodiment with an AC fluid motor,
FIG. 3 shows a device for injecting fluid as fine droplets into a
steam generator,
FIG. 4 shows a further embodiment of the invention wherein the
fluid to be vaporized is drawn from the reservoir tank,
FIG. 5 shows a further embodiment of the invention in which a
resonant coupled acoustic pump is employed to inject the fluid into
a steam generator as fine droplets,
FIG. 6 shows a reservoir tank having a thin walled steam quench for
preventing thermal shock to the reservoir walls,
FIG. 7 shows a further embodiment of the invention wherein the
working fluid is a fuel which is combusted to provide heat,
FIG. 8 shows yet another embodiment of the invention in which fluid
transmitted to the steam generator absorbs heat from the working
fluid in the tank being refilled,
FIG. 9 shows a further embodiment of the invention in which a
porous steam storage bed absorbs heat from the working fluid in the
tank being refilled,
FIG. 10 shows another embodiment of the invention wherein a portion
of the heat in the working fluid is recovered and employed to
generate a mechanical output,
FIG. 11 shows another embodiment in which heat in the fluid on its
way to the fluid motor is transmitted to fluid leaving the fluid
motor on its way to refill one of the reservoir tanks,
FIG. 12 shows another embodiment of the invention wherein a portion
of the working fluid is evaporated from the heat exchanger to cool
the working fluid,
FIG. 13 shows another embodiment of the invention in which the
working fluid which is vaporized absorbs heat from the working
fluid in the tank being refilled,
FIG. 14 shows a further embodiment whereby heat in the working
fluid on its way to the fluid motor is transferred to working fluid
in a second system to cause vaporization of that second fluid and
operation of a second fluid motor,
FIG. 15 shows an embodiment of the invention wherein two systems
are connected together to a single shaft,
FIG. 16 shows an embodiment of the invention in which each
reservoir includes fluids separated by an impermeable barrier which
is able to move within the reservoir,
FIG. 17 shows another embodiment of the invention in which the heat
generated by fuel being combusted is employed to generate vapor
pressure to force the fuel through a fluid motor and into the
combustion chamber,
FIG. 18 shows a modification of the embodiment of FIG. 17 in which
the vapor pressure in the reservoir tank is generated by vaporizing
a portion of the fuel in that tank.
DETAILED DESCRIPTION OF THE DRAWINGS
Reference is now made to FIG. 1 which illustrates a hydrostatic
drive system 18 suitable for use with a DC fluid motor. In this
embodiment, as in many of the other embodiments of the invention,
as discussed in detail below, vapor is alternatively directed into
one of the two reservoir tanks 20 and 22 so that the working fluid
in that tank is forced out of the tank by the pressure of the
vapor, and through a conventional fluidic motor 38 to generate a
mechanical output before it returns to refill the other tank. When
the first tank is substantially depleted, the vapor pressure is
directed into the refilled tank so that the fluid from that tank
now flows again through motor 38 to refill the first, now depleted,
tank.
In FIG. 1, a suitable reservoir 24 of a fluid such as water is
connected to a conventional phase converter or boiler 26 which
converts the fluid from a liquid to a vapor phase. This conversion
may be accomplished by burning a suitable fuel such as a
hydrocarbon adjacent boiler 26 so that the generated heat changes
the phase of at least a portion of the fluid in boiler 26. Any
other suitable arrangement for generating the vapor which is
employed to impart motion to the working fluid can be employed. The
vapor pressure output of boiler 26 is directed to either reservoir
tank 20 or tank 22 via master valve 28 which may be a conventional
solenoid valve or any other suitable type of conventional
mechanism. As depicted schematically in FIG. 1, valve 28 is
operated by a suitable control apparatus 30, which alternately
causes valve 28 to direct the vapor pressure generated by boiler 26
to reservoir tanks 20 and 22. Control 30 may be mechanically or
otherwise linked to the fluid motor 38 so that the position of the
valve 28 is responsive to the physical position of the rotating
part of fluid motor 38. Alternately, control 30 may include means
for sensing the fluid level in tanks 20 and 22 and switching the
tank which is being emptied whenever the fluid in a tank is
detected below a certain predetermined level.
Assuming for the purposes of describing the operation of the
embodiment of FIG. 1 that control 30 has shifted valve 28 to a
position such that the vapor pressure generated by boiler 26 is
transmitted into tank 22 as depicted, then that vapor pressure
pushing the fluid in tank 22 causes working fluid to exit from the
bottom of tank 22 and to flow through motor 38 via one way check
valve 32. Valve 32, as well as the other check valves in this and
the other embodiments set forth below, permit fluid flow in one
direction but prevent it in the other. These valves may be of any
suitable type and are well known in the art. After passage through
motor 38, the moving fluid passes through check valve 34 and enters
tank 20. The differential between the pressure of the fluid exiting
from tank 22 and the fluid exiting from motor 38 prevents fluid
from flowing back through check valves 36 and 38. An exhaust valve
40, which also is shown under the control of apparatus 30, is
vented to the atmosphere during this time so that the fluid can
freely enter chamber 20. Valve 42 at the same time is closed to
prevent the loss of the vapor pressure generated by the flow of
vapor into tank 22 via valve 28.
The cyclic venting of tanks 20 and 22 to the atmosphere results in
a gradual reduction in the quantity of working fluid in the system.
Reservoir 24 provides some makeup fluid since some of the vapor
directed into the tanks condenses therein and is thus added to the
supply of working fluid. However, it may be desirable to provide
some suitable arrangement for automatically or otherwise
replenishing the working fluid from time to time.
When tank 22 has been depleted or substantially depleted, control
mechanism 30 shifts the position of valve 28 so that the vapor
pressure generated by boiler 26 is now directed into tank 20 and
begins to force the fluid which has refilled it out of tank 20 and
through fluid motor 38 via check valve 36. At the same time,
exhaust valve 40 is closed and valve 42 opened by apparatus 30 so
that the fluid now flowing through motor 38 via check valve 36
returns to tank 32 via check valve 39. Open valve 42 permits the
vapor pressure in chamber 22 to escape to the atmosphere so that
tank 22 can refill.
A portion of the fluid flowing out of one or the other of the tanks
20 or 22 also returns to reservoir 24 via valve 46 which may be
controlled by apparatus 30 or may be manually or otherwise adjusted
to provide a suitable flow of liquid into reservoir 24 for
vaporization within boiler 26. As mentioned above, while water is
one suitable material which exists in the vapor and gaseous phase
and can be suitably used in this arrangement, any other suitable
fluid which can be satisfactorily converted from its liquid to its
vapor phase can be employed.
Reference is now made to FIG. 2 which shows another embodiment of
the invention of this application. In this arrangement, the fluid
motor 50 is an AC hydrostatic motor which is capable of converting
reciprocating motion into continuous shaft rotation, e.g., by means
of a reciprocating or swashplate motor. Such AC motors are well
known in the art, and no further discussion of them is necessary.
This embodiment of the invention operates in the same fashion as
the embodiment illustrated in FIG. 1 as discussed above with two
tanks 52 and 54 alternately filled and emptied of the working fluid
by means of vapor generated within boiler 54 and alternately
directed to tanks 52 and 54 by master valve 56 which is under the
control of a suitable control mechanism 58. A reservoir 60 is
provided in the system and a valve 62 connects reservoir 60 to the
fluid in the two tanks for providing additional fluid for
vaporization in boiler 54. Boiler or vapor generator 54 produces
cyclic pressure at N times the hydraulic motor 50 shaft rotation
frequency, N being any suitable integer.
Reference is now made to FIG. 3 which depicts one suitable
arrangement for injecting fluid into a boiler or similar device,
such as boiler 26 depicted in FIG. 1, for conversion into a vapor
phase such as steam. The fluid thus injected is preferably divided
into droplets which are as small as possible to minimize the time
required for vaporization. In the embodiment of FIG. 3, fluid
enters vessel 70 through a conventional inlet valve 72. Vessel 70
is constructed or associated with piezo electric, magnetic
restrictive, or solenoid driven material or structure so that the
volume of vessel 70 is cyclically changed due to the harmonic
residence of its elastic walls. Thus, the fluid which enters vessel
70 through inlet check valve 72 is cyclically injected into boiler
74 for conversion from a liquid to gaseous phase. This injection
technique also finely divides the injected droplets. In fact, inlet
valve 72 may not be required in operation because water is injected
into the boiler steam generator 74 at such high rate to make
backflow through the normally small orifices which will preferably
be employed a negligible problem.
FIG. 4 illustrates another arrangement similar to that of FIG. 1
whereby the fluid which is converted into vapor is derived directly
from the vessels themselves. In this arrangement, fluid lines 76
and 78 are connected to vessels 80 and 82 as shown. Valves 86 and
88 connect lines 76 and 78, respectively, to a conventional boiler
or other steam generator 90 which converts the received fluid from
its liquid to its gaseous phase. Master valve 92 directs the fluid
to tanks 80 and 82 alternately as in the embodiment of FIG. 1, and
the fluid forced from one tank by vapor pressure flows through
actuator or fluid motor 94 and refills the other tank in the same
manner as in FIG. 1. Valves 86 and 88 are operated by control
mechanism 100 which also controls master valve 92 so that fluid is
drawn from the tank which is refilling to provide fluid to be
vaporized to provide the pressure which imparts motion to the
working fluid. As in the other embodiments, vapor pressure in the
tank being refilled is vented to the atmosphere through valves 102
and 104. Valves 86 and 88 are cyclically opened to cause flow into
boiler 90. The heat available from the walls of boiler 90
preferably converts the liquid to vapor. Preferably the period
during which water flows into boiler 90 is related to the speed of
sound in the vapor compared to its speed in the liquid and upon the
geometrical proximities of valves and reservoirs.
FIG. 5 illustrates another embodiment of the invention similar to
that of FIG. 1 in which a hydrostatic resonant coupled acoustic
pump is employed to draw liquid from the drive system to be
converted into vapor within boiler 110. As in the arrangement of
FIG. 1, tanks 112 and 114 are alternately emptied and refilled with
the working fluid by means of vapor pressure which is generated in
boiler 110 and alternately directed into the respective tanks by
master valve 116 which is controlled by a suitable control 120.
Whenever additional working fluid, e.g., water, is required for
boiler 110, tuning fork 120 is set in motion by any suitable
mechanism. For example, in this embodiment tuning fork 120 is shown
connected to the hydrostatic motor 124 by some suitable linkage
mechanism. The horn may also be driven by cams or strikers from the
motor 124. Horn 122 magnifies the acoustic excursion generated by
fork 120 by the inverse ratio of the steam chamber inlet area to
the base area so that water is pushed from the region of tuning
fork 120 through horn 122 and injected into boiler 110 as fine
droplets.
FIG. 6 illustrates one particular reservoir which is believed to be
of particular use in conjunction with a system such as depicted in
FIGS. 1-5 and in the other Figures discussed below. In this
arrangement, the returning hot water enters tank 126 and is kept
from the walls thereof by a thin-walled steam quench 128 which is
provided with a number of holes which permit the returning hot
water to exit therefrom. Quench 128 thus prevents the return water
from thermally shocking the reservoir tank walls and also allows
the heat stored in that wall to generate steam within the reservoir
tank itself.
FIG. 7 illustrates yet another embodiment of the invention
similarly to the basic DC hydrostatic drive system shown in FIG. 1.
In this arrangement, as in the others, fluid from two vessels 130
and 132 is alternately forced through a fluidic motor 134 via
suitable check valves. However, this particular arrangement differs
from those illustrated above in that the fuel which is burned to
generate the heat which is converted to mechanical energy is also
employed as the working fluid. The fuel, e.g., methane, is stored
in a suitable reservoir 136 and added to the system at point 138
where the working fluid exists from fluidic motor 134. The working
fluid which is also the fuel then returns to the tank 130 or 132
which is being refilled through the associated check valve.
Part of the liquid which flows out of the tank 130 or 132 which is
being depleted is also diverted through either valve 140 or 142,
which are both controlled by the control mechanism 134, into either
boiler 150 or 152, respectively, where heat is added to cause the
fuel to change from a liquid to a gaseous state and expand into the
associated tank so as to force the working fluid therein out its
exit to drive fluid motor 138 and refill the other tank. The gas in
the tank which is being refilled, for example, tank 130, is also
exhausted to a burner 160 via either valve 164 or 166. An oxidant
from a suitable reservoir 168 is also supplied to burner 160 for
combusting the gaseous fuel. Thus the liquid fuel serves as the
working fluid and the vapor which must be exhausted from the tank
being refilled then combusted to provide a compact heat source.
Floating head barriers may be disposed in each of the vessels 130
and 132 to increase heat transfer between the gas and fluid
stages.
FIG. 8 illustrates yet another modification of the basic
hydrostatic drive system set forth in FIG. 1. In this arrangement,
heat exchange from the vapor expanding within the reservoir tank to
feed water on its way to the boiler or vapor generators provides a
simple regenerative system. Tanks 170 and 172 are filled with a
suitable working fluid as in the other embodiment, and this working
fluid is alternately forced out of one of the tanks 170 and 172
through fluidic motor 174 to refill the other tank. Further, some
of the fluid forced from tank 172 or 174 is diverted into line 176,
and from line 176, the working fluid thus diverted flows through
either coil 178 or 180 depending on which of the check valves 184
and 186 is open. Valves 184 and 186 are under the control of a
suitable control apparatus 190 as shown so that the fluid is
normally permitted to flow only through the coil 178 or 180 which
is in the tank being refilled. The fluid passing through coil 178
or 180 absorbs heat from the working fluid in the surrounding tank
and from the hot vapor in that tank as it is exhausted. Thus, the
feed fluid enters either boiler 200 or 202 at an elevated
temperature, which reduces the quantity of heat necessary to
convert the fluid from a liquid to a vapor phase before injection
into tank 170 or 172.
FIG. 9 illustrates another embodiment of the invention which is
regenerative in the sense that heat in the working fluid is
employed, at least in part, to generate the vapor pressure which
forces that fluid for one tank through the motor to refill the
other tank. In this embodiment, two tanks 210 and 212 are designed
to be filled to a maximum level which is just below the porous heat
storage bed 214 with a fluid which will change from liquid to vapor
phase at a suitable temperature. When heat is added to one side of
storage bed 214, for example, the side associated with tank 210,
the added heat causes a conversion of some of the fluid in vessel
210 from its liquid to its vapor phase resulting in a volume
expansion which force part of the remaining fluid out the exit of
vessel 210 and through a fluidic motor 220 to refill tank 210. When
tank 210 has been emptied to a desired level, the procedure is
reversed and heat is added to the portion of the porous heat
storage bed 214 associated with tank 212. Next the working fluid in
tank 212 is partially vaporized so that part of the remaining fluid
is out the exit of tank 212 and through fluidic motor 220 into
vessel 210.
Meanwhile in the tank that is being refilled with working fluid,
bed 214 is absorbing heat from the fluid entering that tank. This
heat is retained in bed 214 until that tank has been refilled and
additional heat can thereafter be added to cause partial
vaporization of the fluid in that tank. Thus, the system is
regenerative in the sense that a portion of the heat which is
imparted to the working fluid and not initially used to generate
mechanical output is thereafter removed from the fluid and reused
to generate mechanical output.
FIG. 10 shows yet another embodiment of the invention in which heat
is exchanged in the system in a manner similar to an Ericson cycle.
In this arrangement, heat is generated, for example, by burning
methane or some other suitable fuel in burner 218, and then
conducted into the vessel through coils 220 and 222. Suitable
valves may be provided for switching the flow of the exhaust gases
and the heat to the respective tanks for cyclically emptying and
refilling tanks 224 and 226. The fluid reentering either of the
tanks also passes through a coil 228 or 230 before being emptied
into vessel 226 or 224, respectively, so that the heat which exists
in the fluid which is leaving the tank on its way through motor 232
is in part given back to the water which is returning to the
vessel. Similarly, coils 242 and 244 are provided to at least
partially cool the fluid exiting from motor 232.
FIG. 11 shows yet another embodiment of the invention whereby the
heat imparted to the working fluid which would be otherwise lost is
in part saved and used to generate a mechanical output. In this
embodiment, two tanks 240 242 are alternately filled and emptied
with working fluid which passes through conventional fluid motor
244. Fuel such as kerosene, natural gas, powdered coal or LP gas
from a suitable source 246 is combined with a suitable oxidant and
combusted in a suitable burner 248 after passage through a valve
250 which may be manually or automatically adjusted to permit flow
of a desired amount of fuel. Heat from the burner 248 is employed
to convert the working fluid injected into boilers 252 and 254 into
vapor, in which state it is directed into tanks 240 and 242,
respectively. Suitable valve means may be provided in boilers 252
and 254 if necessary or desirable.
A portion of the fluid exiting from the tank 240 and 242 being
emptied is drawn through either coil 260 or 262 into boiler 252 or
254, respectively. Valves 266 and 268 control the flow of fluid
into coils 260 and 262 and these valves are controlled in turn by a
suitable control apparatus 270 which insures that fluid will enter
only that boiler which is supplying vapor to the tank which is
being emptied. Thus, if fluid is to be forced out of tank 240 by
the addition of vapor to the top thereof, then valve 268 will be
open and valve 266 closed so that the fluid which passes valve 268
will pass through coil 262 and be injected by a suitable injector
into boiler 254. As the working fluid passes through coil 262, heat
is imparted to it by the burner 248 to preheat the fluid so that it
arrives at the boiler at an elevated temperature, thus considerably
increasing the amount of vapor that can be injected into the tanks
240 and 242 within any given period of time.
Further, water or other fluid existing from the tank being emptied
passes through heat exhanger 270 or 272 before passage through
fluid motor 244. These heat exchangers reduce the temperature of
the working fluid on its way to motor 244 and thereby decrease the
possibility of damage to the fluid motor because of exposure to
overheated fluid. The heat in the fluid which enters heat exchanger
272 from the tank 240 or 242 being emptied is in part transferred
to the fluid which is leaving motor 244 and is being returned to
the tank 240 or 242 which is being refilled so that this heat
raises the temperature of the fluid in the tank being refilled.
Reference is now made to FIG. 12 which shows another embodiment of
the engine whereby water derived as a byproduct of hydrocarbon or
other fuel combustion is employed as a makeup supply for the
working fluid of the system and further as means of rejecting into
the atmosphere heat which is not converted into useful mechanical
output. This heat transfer management technique significantly
simplifies the apparatus required for converting chemical potential
energy into shaft work and increases the efficiency compared to
Otto or Diesel cycle processes.
Hydrocarbon fuels yield carbon monoxide and water when burned to
completion in oxygen or oxygen-bearing atmospheres. The amount of
water produced compared to the amount of carbon monoxide produced
depends upon the hydrogen to carbon ratio of the fuel being burned.
In common liquid petroleum fuels, the amount of water produced is
approximately equal to the amount of fuel burned. In liquefied
petroleum gas fuels (butane, propane, methane, etc.) combustion
products tend to an even greater extent to be water. Vaporization
of water at a fixed pressure fixes the boil off temperature. At sea
level the temperature for boil off is about 212.degree. F. and, at
lower atmospheric pressure, the boil off temperature is
correspondingly lower. The embodiment of the invention as
illustrated in FIG. 12 uses this byproduct of hydrogenous fuel
combustion as a makeup working fluid supply.
In this embodiment, as in the other embodiments, two reservoir
tanks 276 and 278 are alternately discharged and refilled with
working fluid which flows from one tank to the other through fluid
motor 280, thus, converting the pressure of the working fluid and
the kinetic energy embodied in the flow of that fluid into useful
output shaft power. The flow of the working fluid is also
cyclically directed via valves 282 and 284 into the boilers 286 and
288 which provide the vapor pressure for forcing the working fluid
cyclially from tanks 278 and 280. Fuel from a suitable source 300
is directed via valve 302 into boilers 286 and 288, respectively.
Valve 302 may be under the control of a suitable mechanism such as
control apparatus 304 which controls valves 282 and 284 as well as
valves 306 and 308 in the same fashion as discussed above.
In contrast to the embodiment illustrated in FIG. 11, the fuel
derived from source 300 is combusted within boilers 286 or 288
which alternately may be any other type of combustion device
suitable for combusting the fuel and directing the combined vapor
and exhaust gases therefrom. The exhaust gases of combustion
together with the water or other vapor produced from the working
fluid are alternately passed into tanks 276 and 278 to force the
fluid therein to flow out the exit and pass through the fluid motor
280. In this fashion, the water vapor which is derived from the
burning of the hydrocarbon fuel and thus added to the system at
least in part replaces the vapor which is exhausted to the
atmosphere by the alternate opening of valves 310 and 312 during
alternate refilling of tanks 276 and 278.
A portion of the fluid existing from motor 280 also passes through
valves 306 and 308 which are under control of apparatus 304 and
enter the evaporator-radiator devices 320 and 322. These devices
are preferably provided with an open top or are otherwise
accessible to the atmosphere so that the fluid that enters these
devices evaporates to the atmosphere taking with it heat imparted
to the evaporating fluid by the working fluid which passes through
coils 324 and 326 on its way to fluid motor 280. Part of the heat
imparted to the fluid in evaporators 320 and 322 is also
transmitted to the fluid returning to tanks 276 and 278 via coils
330 and 332. Thus, part of the heat of the working fluid in tanks
276 and 278 is employed to preheat the fluid returning to the tanks
after passing through motor 280 and part is vented to the
atmosphere so that the fluid which is passed through motor 280 is
at a temperature which will not damage the motor.
As in the other embodiments, the working fluid in this embodiment
may be water or may be more sophisticated solutions, e.g., mixtures
of water and other compounds which might, for example, prevent
freezing, increase lubricity, increase or decrease heat transfer,
or aid or retard absorption and retention of combustion gases.
Conversely, the working fluid may contain a less dense compound or
particle which floats upon its surface, thus providing insulation
between the combustion gases and working fluid during the period
that the pressure is being transmitted in from the hot gases to the
working fluid in the reservoir. Compounds added to the working
fluid may be separated from vaporizable or combustible portions of
the working fluid prior to admission to the generator-combustor
sections such as boilers 286 and 288.
By utilization of common and inexpensive steels, ceramics,
bearings, valves and other hardware, the embodiment of the
invention illustrated in FIG. 12, as well as the embodiments of the
other figures, may be designed to operate at temperatures of, for
example, 2,000.degree. F. and 6,000 lbs. per square inch at the
inlet of the tank receiving the vapor through 160.degree. F. or
lower by use of heat-dams, insulation, and other arrangements such
as flow deflectors and surface coatings. Conversely, the upper
portion of the reservoir walls may be maintained at temperatures
exceeding 1,200.degree. F. if desired, thus allowing heat input and
storage previous to steam generation by conduction of heat into the
fluid at the time during the filling of the reservoir tank that the
fluid level reaches the high wall temperature level.
The basic versatility of the embodiment of FIG. 12 is further
illustrated by the potential of using more than two fluid
reservoirs. Manufacture of 100 horsepower modules consisting of two
reservoirs and one motor actuator allows engine units of 200 hp.,
400 hp., 600 hp., and 1,000 hp., or more, to be assembled simply by
joining the output shafts of each motor to a common output shaft.
Such an output shaft would only have the minimum fabrication
requirement of being attachable per the application function and
would not involve the various sophistications characteristic of
internal combustion engine crankshafts. Similarly multiple
reservoir modules may be hydraulically connected to a single
motor.
The vast variety of hydrostatic, hydraulic, and hydrodynamic
actuators further exemplifies particularly the versatility of the
embodiment of FIG. 12 in various applications only being served
today by complex mechanisms involving clutches, transmissions,
angle drives, universal joints, and differentials. The probability
of costly failure is inherently reduced in the embodiment. Fig. 12,
as well as the other embodiments, compares favorably to
conventional internal combustion reciprocating engines by the
reduced number of workings parts, the reduced metal to metal
relative motion, and the reduced gyratory forces involved. The
ability to achieve high horsepower to weight ratios at high
efficiencies, particularly when materials selections typical to
aircraft turbines are made, makes the engine shown in FIG. 12
preferable to turbines for propeller driven aircraft.
Reference is now made to FIG. 13 which shows another embodiment of
the invention which is somewhat similar to the conventional
Stirling cycle engine. The Stirling cycle distinguishes itself
primarily as one employing regeneration techniques in which heat is
transferred from the working fluid into a thermal reservoir as a
working fluid begins its expansion. After mechanical output has
been generated, the stored heat is readded to the cooled working
fluid as it is being reheated to the maximum temperature of the
cycle.
The embodiment of the invention illustrated in FIG. 13 is similar
in that it is regenerative, but this embodiment also employs
advantageous aspects of both the liquid and gas phases in the
process of converting heat into mechanical work. In the embodiment
illustrated in FIG. 13, heat, for example, produced by combustion
of hydrocarbon or other fuels, nuclear fission, or fusion is
transferred into vapor phases of the working fluid at heat source
350 which may be, for example, a boiler such as in the other
embodiments.
As in the other embodiments, heat from source 350 is employed to
convert working fluid from a liquid to a gaseous phase and to
direct the vapor pressure thus generated alternately into tanks 352
and 354 so that working fluid is forced out of one of the tanks and
through fluidic motor 356 to refill the other tank. A portion of
the working fluid which is forced out of each of the tanks is also
employed to provide liquid for conversion to a gaseous phase.
However, in this embodiment, fluid on its way to a vapor generator
such as a boiler passes through a heating coil in the tank being
refilled so as to absorb as much of the heat as possible from the
fluid entering that tank and also to absorb as much heat as
possible from an extended heat transfer surface which is mounted
adjacent to the coil through which the fluid passes. For example, a
portion of the fluid exiting from tank 352 passes through valve 360
and coil 362 which is mounted in tank 354 as shown. During the time
that tank 354 is refilling, working fluid on its way to boiler 366
passes through tank 354 via coil 362. The fluid returning to tank
354 from motor 356 passes through negative heat rejection coil 364
and the fluid returning to tank 352 through negative heat rejection
coil 365.
Further, an extended heat transfer surface comprising coil 367
within tank 354 is mounted adjacent coil 362. Coil 367 absorbs heat
from the working fluid reentering tank 354 and also absorbs heat
from the exhaust gases generated by source 350 which are exhausted
to the atmosphere via coil 367 as well as coil 370. The heated
fluid existing from coil 362 is injected into boiler 366 where it
is converted into its vapor phase and that vapor then transmitted
to tank 352 to force the working fluid therein out its exit and
through motor 356. Coils 368 and 370 within tank 352 operate
similarly when that tank is being refilled, and tank 354 is being
emptied. As shown, coils 362 and 368, which each preferably
comprise a hollow coil, are connected to an exhaust 372 so that,
for example, the hot combustion gases are transmitted through coils
366 and 368 so that the heat of the combustion gases can, at least
in part, be imparted to the working fluid which is to be vaporized
and eventually employed to generate a mechanical output. Nuclear
loop transfers, of course, would not need an exhaust but preferably
employ a similar circuit to optimize the efficiency of energy
conversion.
Reference is now made to FIG. 14 which shows yet another embodiment
of the invention. In this arrangement, two or more working fluids
are employed to permit extension of the thermal gradiant to higher
and lower temperatures than allowed by a single working fluid. This
arrangement offers considerable advantages from the standpoint of
thermodynamics. In this embodiment, as in the embodiment of FIG.
11, fuel from a suitable source 400 is burned by a suitable burner
402 adjacent conventional boilers 406 and 408. Vapor thus generated
is alternately directed into reservoir tanks 410 and 412, one of
which is continually emptying and refilling the other through
fluidic motor 414 and thus generating a continuous and useful
mechanical shaft output.
However, fluid issuing from either of the tanks 410 or 412 passes
through a heat exchanging coil 414 or 416 on its path through motor
414, thus imparting heat to the fluid in lines 420 and 422
respectively which will normally contain working fluid having a
different critical point than the working fluid in tanks 410 and
412. The heat thus imparted causes the fluid in lines 420 and 422
to change from its liquid to its vapor phase and the resulting
expansion of the working fluid causes the fluid in tanks 424 and
426 alternately to be forced through a second fluid motor 426 which
may be in parallel with the first motor for combining the
mechanical shaft output.
A number of combinations of working fluids can be employed in this
arrangement. A few examples are mercury and water, mercury and
potassium-sodium eutectic, water and freon, water and silicone
fluids, freon and liquefied gases and many others. A simple
extension of the illustrated system permits the development of
engines which use three or four or more working fluids.
Reference is now made to FIG. 15 which shows yet another embodiment
of the invention in which two hydrostatic systems, each having two
tanks are employed to operate a single shaft with two motors 402
and 404 connected in parallel. It should be apparent that any
number of systems such as illustrated above can connected together
to generate any desired power output.
FIG. 16 shows yet another embodiment of the invention wherein
elastic diaphragms 410 and 412 are connected between two working
fluids. The diaphragms separate each of the two tanks 416 and 418
into an upper and lower compartment. The fluid in the upper
compartment, for example, the fluid in the upper part of tank 418
can be expanded for any suitable means, for example, by heating in
boiler 420 with the result that the downward pressure exerted by
elastic diaphragm 412 forces the fluid in the lower portion of tank
418 out of its exit and through hydrostatic motor 420 thus deriving
a mechanical output. The fluid thus forced from tank 412 then
refills the bottom portion of tank 410 which then forces the fluid
out of the upper portion and thereof and into the upper portion of
tank 418 via valve 422. The process is then reversed with the fluid
in the lower portion of tank 410 being forced out by the fluid
expanded by boiler 426 and directed into the upper portion of tank
410. Similarly pistons, bellows, and floating particles may be used
to separate the fluids.
Reference is now made to FIG. 17 which shows a hydrostatic drive
system employing only a single reservoir tank 424. This embodiment
which could be used, for example, in a rocket system for travel in
outer space employs the heat generated by the fuel which is
combusted to supply the rocket thrust to impart motion to the fuel
which then serves as the working fluid for conventional hydrostatic
or other similar motor 426. The heat generated in combustion
chamber 428 which is normally wasted is employed to convert the
fuel fluid from a liquid to a gaseous state in pressure source 430
so that the pressure thus generated forces the fuel fluid in tank
424 out its exit and through motor 426 to be burned in combustion
chamber 428. A cooling arrangement 432 can be disposed adjacent the
tank 424 for condensing some of the vapor added to tank 424 into a
liquid which can then be used as the working fluid and combusted
after passage through motor 426.
FIG. 18 shows a modification of the embodiment of FIG. 7 whereby
the heat generated by combusting the working fluid in a combustion
chamber 440, for example, to generate thrust to propel a rocket or
other vehicle is employed by a heater 442 which has coils disposed
about reservoir tank 444 which is filled with a suitable fuel
fluid. The heat added to the fluid in tank 444 by heater 442 causes
a portion of it to be converted into a vapor state and expand, thus
forcing part of the working fluid in chamber 444 out past valve 446
and through fluid motor 448 to combustion chamber 440 where it is
burned. Thus, the waste heat from the combustion is employed to
generate the mechanical output which can be employed in the device
for any purpose desired.
The above discussed embodiments of the invention can of course be
satisfactorily employed in a number of applications. These include,
but are not limited to:
a. Air heating and cooling,
b. Lawn mowers,
c. Motor-generator units,
d. Garden Tractors,
e. Sump pumps,
f. Garbage Disposal and Compaction,
g. Irrigation pumps,
h. Electrical Power Generation
i. Compressor Stations
j. Oil and Gas Drill Drilling and Pumping
k. Elevators and Lifts
l. Conveyors
m. Ore Crushers and Pulverizers
n. Grain mills
o. Scrap Shredders and Compactors
p. Automobile
q. Rail Cars
r. Bus and Train
s. Truck and Tractors
t. Other Farm Equipment
u. Highway construction equipment
v. Pleasure and Commercial Boats
w. Aircraft
The following table represents a few resultant engine horsepowers
and weights based upon the use of fired boiler rated steels and
conventional hydrostatic motors as derived from computer modeling
studies.
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TABLE
maximum No. Engine Continuous of Full Torque Total engine shown in
hp. Reser r.p.m. range dry weight to voirs
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FIG. 12 5 2 100-2000 or 30 lb. 2000-20,000 FIG. 12 15 4 100-2,000
or 72 lb. 2,000-20,000 FIG. 13 50 4 100-2,000 128 lb. FIG. 13 100 4
100-2,000 182 lb. FIG. 11 300 2 100-2,000 287 lb. FIG. 11 600 4
100-2,000 665 lb.
__________________________________________________________________________
The use of titanium alloys, composites, and coatings will permit
considerable improvement in the weight to power ratios of the
Table. However, for most applications the Table ratios will be
sufficient.
Many changes and modifications in the above discussed embodiments
of the invention can of course be made without departing from the
scope of the invention. Accordingly, that scope is intended to be
limited only by the scope of the appended claims.
* * * * *