U.S. patent application number 11/895667 was filed with the patent office on 2008-02-28 for heat regenerative mini-turbine generator.
Invention is credited to Harry Schoell.
Application Number | 20080047272 11/895667 |
Document ID | / |
Family ID | 39112074 |
Filed Date | 2008-02-28 |
United States Patent
Application |
20080047272 |
Kind Code |
A1 |
Schoell; Harry |
February 28, 2008 |
Heat regenerative mini-turbine generator
Abstract
A compact, lightweight steam turbine is connected to a central
shaft that drives a high pressure pump, a high efficiency generator
and a blower. An igniter burns fuel exiting a fuel injector to
generate heat in a cyclone combustion chamber. Water pumped through
coils is heated in the combustion chamber to produce steam energy
to drive the turbine. Exhaust steam is directed through a
centrifugal condenser having an arrangement of flat plates to
condense the steam to a liquid state. The turbine drives the
generator at a high rpm, through the connected shaft, to generate
electric power.
Inventors: |
Schoell; Harry; (Pompano
Beach, FL) |
Correspondence
Address: |
Robert M. Downey, P.A.
Ste. 300, 6751 N. Federal Hwy.
Boca Raton
FL
33487
US
|
Family ID: |
39112074 |
Appl. No.: |
11/895667 |
Filed: |
August 27, 2007 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
60840786 |
Aug 28, 2006 |
|
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Current U.S.
Class: |
60/648 ;
60/670 |
Current CPC
Class: |
F01K 11/02 20130101 |
Class at
Publication: |
60/648 ;
60/670 |
International
Class: |
F01K 17/04 20060101
F01K017/04 |
Claims
1. A generator for producing electric power comprising: a
combustion chamber; a fuel burner for burning fuel to generate heat
in said combustion chamber and including a fuel injector
communicating with said combustion chamber and an igniter for
burning fuel exiting said fuel injector; a blower for directing air
flow into said combustion chamber to promote burning of the fuel
and for circulating the heat from the burning fuel through said
combustion chamber; at least one steam tube coil in said combustion
chamber; at least one steam ejection nozzle connected to said at
least one steam tube coil; a water pump for pumping water from a
collection reservoir through said at least one steam tube coil,
wherein the water is heated by the heat in said combustion chamber
to produce steam for release from said at least one steam ejection
nozzle; a steam driven turbine; said at least one steam ejection
nozzle being structured and disposed to direct a flow of
pressurized steam into said turbine to cause driven rotation of
said turbine; a central shaft connected to said turbine and
rotatable with said turbine; an alternator driven by rotation of
said central shaft for generating electric current; a condenser for
condensing exhaust steam exiting said turbine to produce liquid
condensate, and said condenser being structured to direct the
liquid condensate into the collection reservoir; and an electric
power output connected to said alternator.
2. The generator as recited in claim 1 further comprising: a
plurality of said steam tube coils in said combustion chamber; and
a plurality of said steam ejection nozzles, with each of said
plurality of steam ejection nozzles connected to a respective one
of said plurality of steam tube coils, and said plurality of steam
ejection nozzles being structured, disposed and arranged to direct
the flow of pressurized steam into said turbine to cause driven
rotation of said turbine.
3. The generator as recited in claim 1 wherein said combustion
chamber surrounds said at least one steam tube coil.
4. The generator as recited in claim 2 wherein said combustion
chamber is structured and disposed to surround said plurality of
steam tube coils.
5. The generator as recited in claim 1 wherein said water pump is
driven by rotation of said central shaft.
6. The generator as recited in claim 1 wherein said blower is
driven by rotation of said central shaft.
7. The generator as recited in claim 1 wherein said blower is
structured and disposed for directing the air flow around said
condenser for cooling the exhaust steam.
8. The generator as recited in claim 1 wherein said electric power
output includes a voltage regulator.
9. The generator as recited in claim 8 wherein said electric power
output includes at least one pair of connection terminals.
10. The generator as recited in claim 1 further comprising: a fuel
tank for holding a supply of fuel; and a fuel pump for directing
fuel from said fuel tank to said fuel burner.
11. A generator for producing electric power comprising: a
combustion chamber; a fuel burner connected to a fuel supply, and
said fuel burner being structured for burning fuel to generate heat
in said combustion chamber; a blower for directing air flow into
said combustion chamber to promote burning of the fuel and for
circulating the heat from the burning fuel through said combustion
chamber; at least one steam tube coil in said combustion chamber;
at least one steam ejection nozzle connected to said at least one
steam tube coil; a water pump for pumping water from a collection
reservoir through said at least one steam tube coil, wherein the
water is heated by the heat in said combustion chamber to produce
steam for release from said at least one steam ejection nozzle; a
steam driven turbine; said at least one steam ejection nozzle being
structured and disposed to direct a flow of pressurized steam into
said turbine to cause driven rotation of said turbine; a central
shaft connected to said turbine and rotatable with said turbine; an
alternator driven by rotation of said central shaft for generating
electric current; a condenser for condensing exhaust steam exiting
said turbine to produce liquid condensate, and said condenser being
structured to direct the liquid condensate into the collection
reservoir; and an electric power output connected to said
alternator.
12. The generator as recited in claim 11 further comprising: a
plurality of steam tube coils in said combustion chamber; and a
plurality of said steam ejection nozzles, with each of said
plurality of steam ejection nozzles connected to a respective one
of said plurality of steam tube coils, and said plurality of steam
ejection nozzles being structured, disposed and arranged to direct
the flow of pressurized steam into said turbine to cause driven
rotation of said turbine.
13. The generator as recited in claim 11 wherein said combustion
chamber surrounds said at least one steam tube coil.
14. The generator as recited in claim 12 wherein said combustion
chamber is structured and disposed to surround said plurality of
steam tube coils.
15. The generator as recited in claim 11 wherein said water pump is
driven by rotation of said central shaft.
16. The generator as recited in claim 11 wherein said blower is
driven by rotation of said central shaft.
17. The generator as recited in claim 11 wherein said blower is
structured and disposed for directing the air flow around said
condenser for cooling the exhaust steam.
18. The generator as recited in claim 11 wherein said electric
power output includes a voltage regulator.
19. The generator as recited in claim 18 wherein said electric
power output includes at least one pair of connection
terminals.
20. The generator as recited in claim 11 further comprising: a fuel
tank for holding the supply of fuel; and a fuel pump for directing
fuel from said fuel tank to said fuel burner.
Description
BACKGROUND OF THE INVENTION
[0001] This non-provisional patent application is based on
provisional patent application Ser. No. 60/840,786 filed on Oct.
28, 2006.
DISCUSSION OF THE RELATED ART
[0002] Portable generators for producing electricity are typically
powered by combustion engines fueled by gasoline or diesel.
Combustion engine powered portable generators are known to be noisy
(i.e. loud) and are not fuel efficient. For this reason, portable
generators powered by combustion engines are primarily used for
emergency power situations when more efficient conventional power
sources are unavailable. Additionally, gasoline and diesel powered
combustion engines are considerably heavy and bulky. This adds to
the overall size and weight of portable generators, making them
difficult to transport when used in mobile field operations.
[0003] Accordingly, there remains an urgent need for a fuel
efficient portable generator that is relatively quiet, compact in
size, lightweight and easy to transport. Further, there is a need
for a portable, fuel efficient generator that operates on multiple
fuel types, including a mixture of different fuel types. Finally,
there is a need for a portable, fuel efficient generator that uses
heat regeneration for greater efficiency.
SUMMARY OF THE INVENTION
[0004] The present invention provides a heat regenerative
mini-turbine generator in a compact, lightweight unit. The unit
includes a steam turbine connected to a central shaft that drives a
high pressure pump, a high efficiency generator and a blower. An
igniter burns fuel exiting a fuel injector to generate heat in a
cyclone combustion chamber. Water pumped through coils is heated in
the combustion chamber to produce steam energy to drive the
turbine. Exhaust steam is directed through a centrifugal condenser
having an arrangement of flat plates to condense the steam to a
liquid state. The turbine drives the generator, through the
connected shaft, to generate electric power. It is necessary to
drive the generator at a high rpm to achieve the lightweight and
small size. However, it is known that turbines in small sizes have
poor efficiency. The use of heat regeneration helps this
deficiency. The turbine heat exchanger, condenser and re-heaters
are all contained in one small package. The unit is water
lubricated and operates in a closed loop system. According to
several preferred embodiments, the generator unit operates in a
compact envelope at weight of approximately 10-25 lbs. The unit
size can be scaled up or down to accommodate different power output
requirements.
BRIEF DESCRIPTION OF THE DRAWINGS
[0005] For a fuller understanding of the nature of the present
invention, reference should be made to the following detailed
description taken in conjunction with the accompanying drawings in
which:
[0006] FIG. 1 is a top plan view, shown in partial phantom lines,
illustrating the heat regenerative mini-turbine generator of the
present invention;
[0007] FIG. 2 is a side elevational view, in partial cross-section,
showing the main component parts of the heat regenerative
mini-turbine generator; and
[0008] FIG. 3 is an isolated view of a steam ejector nozzle fitted
to a turbine housing for ejecting a pressurized flow of steam
against a cupped perimeter of a turbine wheel to forcibly drive
rotation of the turbine wheel and a central shaft.
[0009] Like reference numerals refer to like parts throughout the
several views of the drawings.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0010] Referring to the several views of the drawings, and
initially FIG. 2, the heat regenerative mini-turbine generator is
shown and is generally indicated a 10.
[0011] The generator 10 is supported on a base 12 that may include
feet 14 on the bottom for supported engagement on a floor, ground
or counter surface. A fuel tank 16 rests on the top of the base. In
a preferred embodiment, the fuel tank 16 is circular (i.e. donut
shaped) to provide an open central area above the base that
accommodates a centrifugal blower 22 and an alternator 20. A fill
spout 18 with a cap 19 extends upwardly from the fuel tank to
facilitate refilling of fuel.
[0012] A condenser chamber 30 sits above the fuel tank 16 and
alternator 20 and contains a centrifugal condenser 32 and a
condensate collection pan 36 at the bottom of the condenser
chamber. The centrifugal condenser has a spaced arrangement of
condenser plates 34 that present a large surface area for
maximizing heat transfer within a relatively compact space. A sight
gauge 38 on the exterior of the condenser chamber indicates a
working fluid level (i.e. water level) within the condensate
collection pan 36. Water can be added through a fill spout 37 at
the top of the site gauge by removing a pressure relief cap 39.
When a desired working fluid level is indicated in the sight gauge
38, the pressure relief cap 39 is replaced on the fill spout
37.
[0013] A fuel pump 40 pulls fuel from the fuel tank 16 and directs
a supply of fuel through hose 42 leading to fuel injector 44. The
fuel injector 44 directs a spray of fuel past an igniter 46 to burn
the sprayed fuel. The burning fuel is directed into a cyclone
combustion chamber 50 that surrounds a tube bundle 54. An igniter
coil 48 connects to the igniter 46 and is powered by a battery (not
shown). The blower 22 directs air flow from air intake 58 on the
base 12 of the generator through the condenser chamber 30, about
the exterior of the centrifugal condenser plates 34. A portion of
the air flow (approximately 20%) from the blower 22 is directed to
air duct 60 leading to the cyclone combustion chamber 50, thereby
providing sufficient airflow to promote combustion of the fuel. The
directed airflow into the cyclone combustion chamber 50 helps to
circulate the heat around the circular combustion chamber so that
hot gases from combustion circulate around and over the tube bundle
54. The cyclone combustion chamber 50 is surrounded by an insulated
wall structure, including an insulated cover 64 and an insulated
central section 65 partially surrounding a turbine housing 70. The
turbine housing 70 is centrally positioned above the centrifugal
condenser 32 and contains a turbine wheel 72. The central shaft 76
is fixed to the center of the turbine wheel 72 and is supported on
bearings 78. The shaft 76 extends downwardly from the turbine wheel
72 and into driven engagement with the alternator 20 and blower 22
at the lower end. Rotation of the shaft 76 drives the blower 22,
the alternator 20 and a centrifugal water pump 80 in the bottom of
the condensate collection pan 36. The water pump 80 directs a flow
of water to bypass governor 84. At normal operating pressure, water
flow is directed to heat exchanger 86 at the top of the centrifugal
condenser 32 for pre-heating the water. From the heat exchanger 86,
the water flow is directed to a conduit 87 leading to a splitter
valve 88 at the top center of the combustion chamber. The splitter
valve 88 directs the water flow through the tube bundle 54 leading
to multiple steam ejector nozzles 90. In a preferred embodiment,
the splitter valve splits into four separate tubes 92 in the tube
bundle 54, with each tube 92 leading to one of four steam ejector
nozzles 90. In the tube bundle 54, within the cyclone combustion
chamber 50, the pre-heated water is heated to produce steam which
is directed to each of the steam ejector nozzles 90. The steam
ejector nozzles 90 are fitted to the turbine housing 70 and are
arranged at an optimal angle and position to direct the ejected
steam into cup shaped members 73 about the periphery of the turbine
wheel 72. The force from the ejected steam drives the turbine wheel
72 to rotate the shaft 76. When the turbine wheel RPMs get above
normal operating speed (i.e. too high), the increasing pressure of
water flow from the water pump 80 causes a valve member in the
bypass governor 84 to be operated to a bypass position, causing
water flow to bypass the normal passage 85 leading to the heat
exchanger 86 and, instead, going to a conduit 94 leading to the
turbine housing 70. In the bypass position, the pressurized water
flow is directed into the turbine housing and against the turbine
wheel 72, with the impinging force of the pressurized water flow
against the flat face of the turbine wheel 72 having the effect of
slowing the turbine wheel, and, thereby, slowing the RPMs to a
normal operating speed.
[0014] Air flow through the condenser chamber 30 from blower 22 is
exhausted through cooling exhaust port 96. Combustion gases within
the cyclone combustion chamber are exhausted through exhaust port
98 on the top of the cover.
[0015] An electric control panel 100 includes an ON/OFF switch 102
to start and stop operation of the generator. Upon initial start
up, the ON/OFF switch 102 is operated to energize the alternator
20. During startup, the alternator 20 is motorized, using power
from the battery (not shown) to turn the shaft 76 and turbine wheel
72. This allows for initial operation of the blower 22, water pump
80 and fuel pump 40. The fuel pump 40 then directs the fuel supply
to the injector 44 and igniter 46 assembly to generate hot gases in
the cyclone combustion chamber 50, while the water pump 80 directs
water flow to the tube bundle 54. Once steam is produced, the
turbine wheel 72 is driven by the ejected steam and the alternator
20 switches from start up mode to normal alternator operation.
[0016] A voltage regulator 104 on the side of the unit connects to
the alternator 20. The voltage regulator 104 provides DC voltage at
connection terminals 106,108.
[0017] While the present invention has been shown and described in
accordance with a preferred and practical embodiment, it is
recognized that departures from the instant disclosure are
contemplated within the spirit and scope of the invention which,
therefore, is not to be limited except as defined in the following
claims, as interpreted under the doctrine of equivalence.
* * * * *