AU2007225001B2

AU2007225001B2 - A steam driven engine

Info

Publication number: AU2007225001B2
Application number: AU2007225001A
Authority: AU
Inventors: David Ernest Ide
Original assignee: Bluegreen Power Technologies Pty Ltd
Current assignee: Bluegreen Power Technologies Pty Ltd
Priority date: 2006-03-10
Filing date: 2007-03-08
Publication date: 2012-03-22
Anticipated expiration: 2027-03-08
Also published as: AU2007225001A1

Abstract

A steam driven engine including a piston adapted to reciprocate within a chamber, and a means for mixing a heated air supply and a heater water supply at or near the piston face, in order to create the steam to drive the piston.

Description

PCT/AU2007/000292 Received 12 February 2008 A STEAM DRIVEN ENGINE TECHNICAL FIELD The present disclosure relates to a steam driven engine, and in particular an internal steam generating engine, a system incorporating the engine, and a 5 method of operation for said engine. BACKGROUND ART The principle of utilising steam to drive a reciprocating piston engine is well known. Nearly all known examples of these engines generate the steam external to the chamber in which the piston reciprocates, and then convey this 10 steam to the chamber via piping. As a result, insulation known as lagging is required in order to prevent thermal losses, which in spite of the preventative measures, are considerable. It is an object of the present disclosure therefore to provide a steam driven engine that substantially ameliorates the aforementioned difficulty, or at the 15 least provides the public with a useful alternative to known steam driven engines. Other objects and advantages of the present disclosure will become apparent from the following description, taken in connection with the accompanying drawings, wherein, by way of illustration and example, an embodiment of the 20 present invention is disclosed. DISCLOSURE OF THE INVENTION One aspect of the present disclosure includes a steam driven engine including a piston adapted to reciprocate within a chamber, said engine generating steam to drive the piston by mixing a supply of heated water with a supply of heated 25 air in the chamber, and wherein the heated air is supplied to the chamber by an engine driven compressor. Amended Sheet

IPEA/AU

2 Preferably, the compressor is in turn driven by exhaust steam from the engine. Preferably, in an alternative, the compressor Is either an electrically or mechanically driven by or via the engine. Preferably, the compressor is part of a turbocharger, the turbine of which is 5 driven by the exhaust steam from the engine Another aspect of the present disclosure includes a piston adapted to reciprocate within a chamber, said engine generating steam in the chamber to drive the piston by mixing a supply of heated water with a supply of heated air in the chamber, and wherein the heated air is supplied by a turbocharger that is 10 driven by exhaust steam from the engine. Preferably, the supply of heated water and the supply of heated air are mixed in the chamber, at or near a face of the piston. Preferably, supply of heated water is released into an atmosphere of the heated air so as to create the steam. 15 Preferably, in an alternative, a supply of heated air is released into a mist of the heated water. Preferably, in an alternative, supplies of heated air and water are released into the chamber simultaneously. Preferably, the supply of heated air has been heated to a temperature above 20 the boiling temperature of the water. Preferably, the supply of water has been heated to a temperature approaching boiling temperature, but not to boiling temperature, Preferably, the chamber includes an air inlet for the supply of heated air, a water inlet for the supply of heated water, and a steam outlet. 25 Preferably, the steam outlet is a valve-closed port Amended Sheet IPEA/AU - PCT/AU2007/000292 Received 12 February 2008 3 Preferably, the air inlet is a valve-closed port and/or an injector, and the water inlet is an injector or atomiser. Preferably, the means for heating the supply of water is an electric heater. Preferably, in an alternative, the means for heating the supply of water is a heat 5 exchanger. Preferably, the heat exchanger utilises steam exhausted from the chamber to heat the supply of water prior to its release into the chamber. Preferably, supplementary heating of the air may be achieved by directing the air supply through the heat exchanger. 10 Another aspect of the present disclosure includes a method of operation for the steam driven engine as in any one of the preceding claims, including the steps of releasing a supply heated air into the chamber, releasing a supply of heated water into the air, thereby creating steam, which then expands and drives the piston down. 15 Preferably, the air is compressed by the piston prior to the water being released therein. Another aspect of the present disclosure includes a method of operation for the steam driven engine as in any one of the preceding claims, including the steps of releasing a supply heated air into the chamber, compressing this supply of 20 heated air with the piston, releasing a supply of heated, misted water into the chamber, and releasing a further supply of heated air into the supply of heated, misted water, the method creating steam which then expands and drives the piston down. Another aspect of the present disclosure includes a method of operation for the 25 steam driven engine as in any one of the preceding claims, including the steps of releasing a supply of the heated air into the chamber, compressing this supply of heated air with the piston, releasing a supply of heated, misted water Amended Sheet

IPEA/AU

4 and a further supply of the heated air into the chamber simultaneously, the method creating steam, which then expands and drives the piston down. Preferably, the method includes the further step of shutting off water and air supply to the chamber.. 5 Preferably, the method includes the further step of opening a valve to the exhaust port, and allowing the piston to drive the vapour out of the chamber. Preferably, a further supply of the heated compressed air is introduced as the exhaust port is opened for the purpose of assisting evacuation of the vapour from the chamber. 10 Preferably, the method includes the further step of inducing a fresh charge of air by utilising the partial vacuum created by the downwardly traveling piston. In this respect, before explaining at least one embodiment of the invention in detail, it is to be understood that the invention is not limited in its application to the details of construction and to the arrangements of the components set forth 15 in the following description or illustrated in the drawing. The invention is capable of embodiments in addition to those described and of being practiced and carried out in various ways. Also, it is to be understood that the phraseology and terminology employed herein, as well as the abstract, are for the purpose of description and should not be regarded as limiting. 20 The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate certain embodiments of the invention, and together with the description, serve to explain the principles of the invention. Those skilled in the art will appreciate that the conception upon which this disclosure is based may readily be utilized as a basis for designing other 25 structures, methods, and systems for carrying out the several purposes of the present invention, It is important, therefore, to recognize that the claims should be regarded as including such equivalent constructions insofar as they do not depart from the spirit and scope of the present invention. Amended Sheet

IPEA/AU

PCT/AU2007/000292 Received 12 February 2008 5 BRIEF DESCRIPTION OF THE DRAWINGS Por a better understanding of this disclosure it will now be described with respect to an exemplary embodiment which shall be described herein with the assistance of drawings wherein: 5 Figure 1 is a schematic diagram of an exemplary system incorporating the engine and its ancillary equipment; Figures 2 through 5 are schematic diagrams illustrating the operating cycle of the exemplary engine in Figure 1; and Figure 6 is a schematic diagram of a system incorporating the engine and its 10 ancillary equipment according to a further embodiment of the invention. BEST MODE FOR CARRYING OUT THE INVENTION Referring now to figure 1, where there is illustrated a steam driven engine 1, having a piston 2 that is adapted to reciprocate within a bore 4 of an engine block 6, so as to define a closed chamber 8, the volume of which changes as 15 the piston 2 reciprocates, The piston 2 is connected by a connecting rod 10 to a crankshaft 12 so as to convert the reciprocal motion of the piston 2 into rotary motion at the crankshaft 12. The steam utilised to drive the piston 2 is generated in the chamber 8 by mixing heated air and water; but we will consider this process in further detail below. 20 For the purpose of explanation, we will consider the flow path for the air, water and the resultant steam in turn, in order to introduce the various components of the system in which the engine 1 operates. In use, the water supply is pumped from a water reservoir 20 by a pump 22 and through a sequence that includes a water filter 24, a heat exchanger 26 (where 25 the water is heated to a temperature just below boiling temperature), and then a water atomiserinjector 28, which outlets the water as a fine mist into the chamber 8. Amended Sheet

IPEA/AU

6 The air supply is drawn from atmosphere and passed through a sequence that includes an air filter 30, a compressor 32 of a turbocharger 34 (in which the air is pressurised and heated in accordance with Charles's law: "when a gas is compressed its temperature is raised"), over an electric heating element 35, 5: and then to an inlet valve closed port 36 of the chamber 8. The compressor 32 of the turbocharger 34 should be designed and sized so as to heat the air to a temperature higher than the boiling temperature of water. The electric heating element 25 then is positioned just before the air inlet port 36. Its purpose is to compensate for any heat losses that might occur between 10 the compressor 32 and the inlet port 36, and to ensure that the air is hot enough to create steam when it mixes with the mist of water in the chamber 8. The exhaust steam is exhausted via a valve-closed exhaust port 40 and then through a sequence that includes a turbine 33 of the turbocharger 34, and the heat exchanger 26. The steam is condensed in the heat exchanger 26, and the 15 water is returned to the reservoir 20. A pressure relief valve ensures that pressure in the reservoir is maintained at an acceptable level. The heat exchanger 26 then transfers heat between exhaust steam from the engine 1 and the water supply to the engine. The mechanisms for driving and timing the operation of the inlet and exhaust 20 valves is the same as that used for a conventional internal combustion engine, namely, either one or more overhead camshafts 50, or alternatively a combination of pushrods and rockers, that are mechanically driven by and synchronised with the crankshaft 12. Referring now to Figures 2 through 5, where the engine cycle is considered in 25 greater detail. As such, we notionally select the step of inducing air into the engine 1 as being the first step in an engine cycle. With the exhaust port 36 closed and the inlet port 40 opened (see Figure 2), the partial vacuum created as the piston 2 travels downward induces a fresh charge of hot air. Amended Sheet

IPEA/AU

7 The inlet port 36 is then closed by its valve, and the piston 1 travels upward, further compressing and heating the air (see Figure 3). Still referring to Figure 3, the hot water 60 is injected into the hot air filled chamber 8 by injector 28 when the piston is at or near top dead centre (TDC), 5 instantly generating steam (or more correctly, water vapour); the resultant expansion in volume (steam has up to 1600 times the volume of water) drives the piston 2 downwards creating a work output at the crankshaft (see Figure 4). Referring now to Figure 5, the exhaust port 40 is opened, and the upward travel of piston 1, which is derived from the momentum carried by the rotating 10 components, drives the water vapour (air and steam mixture) out of the chamber 8. At this stage a further supply of the heated compressed air may be introduced into the chamber via either of a valve closed port or injector (which ever may be applicable) as the exhaust port is opened, this further supply bring for the purpose of assisting evacuation of the vapour from the chamber. 15 The exhaust port 40 closes, the inlet port 36 opens, and a fresh charge of heated air Is Induced, and the.cycle restarts. In order to get the engine running, an electric heater 60 is incorporated into the heat exchanger, and an electric motor is used to drive the pump and the compressor. These electric items would be powered by a battery at start up, but 20 it is anticipated that they would be switched of automatically once the system had reached operating pressures and temperatures i.e. all ancillary equipment would then be powered by the engine 1 itself. Referring now to Figure 6, where the turbocharger has been replaced by a mechanical or electric air compressor 100 having a storage tank 102. This air 25 compressor may be driven either directly or indirectly (in the case of an electric compressor) by the engine 1. Amended Sheet

IIPEA/AU

8 A charge of compressed air from the compressor 100 would then be introduced into the chamber by way of the valve closed inlet port or indeed a suitable injector 104, at the same point in the cycle as described above. What is more, air may also be introduced during the exhaust stroke so as to 5 help evacuate the steam or water vapour from the chamber 8. The compressed air supply line may run relative to the water supply line as shown at 108 so that some heating of the water supply takes place, thereby acting in effect, as a heat exchanger, it is also considered that compressed air may be stored in the compressors 10 tank 102 so that it may be used to assist in starting the engine with an air starter (not shown). It is considered that the engine according to the present invention has the potential to be a useful alternative to known steam engines, particularly considering that it does away with the requirement for a boiler or external steam 15 generator. Although the Invention has been herein shown and described in what is conceived to be the most practical and preferred embodiment, it is recognised that departures can be made within the scope of the invention, which is not to be limited to the details described herein but is to be accorded the full scope of 20 the appended claims so as to embrace any and all equivalent devices and apparatus. Amended Sheet

IPEA/AU

Claims

1. A steam driven engine including a piston adapted to reciprocate within a chamber, said engine generating steam to drive the piston by mixing a supply of heated water with a supply of heated air in the chamber, and wherein the 5 heated air is.supplied to the chamber by an engine driven compressor.

2. The engine of claim 1, wherein the compressor is in turn driven by exhaust steam from the engine.

3. The engine as in either one of the preceding claims, wherein the compressor is part of a turbocharger, the turbine of which is driven by the 10 exhaust steam from the engine.

4. A steam driven engine including a piston adapted to reciprocate within a chamber, said engine generating steam in the chamber to drive the piston by mixing a supply of heated water with a supply of heated air in the chamber, and wherein the heated air is supplied by a turbocharger that is driven by exhaust 15 steam from the engine.

5. The steam driven engine as in any one of the preceding claims, wherein the supply of heated water and the supply of heated air are mixed in the chamber, at or near a face of the piston.

6. The steam driven engine as in any one of the preceding claims, wherein 20 a supply of heated water is released into an atmosphere of the heated air so as to create the steam.

7. The steam driven engine as in any one of claims.1 to 5, wherein a supply of heated air is released into a mist of the heated water.

8. The steam driven engine as in any one of claims 1 to 5, wherein supplies 25 of heated air and water are released into the chamber simultaneously. Amended Sheet IPEA/AU 10

9. The steam driven engine as in any one the preceding claims, wherein the supply of heated air has been heated to a temperature above the boiling temperature of the water.

10- The steam driven engine as in any one of the preceding claims, wherein 5 the supply of water has been heated to a temperature approaching boiling temperature, but not to boiling temperature.

11. The steam driven engine as in any one of the preceding claims, wherein the chamber includes an air inlet for the supply of heated air, a water inlet for the supply of heated water, and a steam outlet. 10 12. The steam driven engine as in claim 11, wherein the steam outlet is a valve-closed port.

13. The steam driven engine as in claim 11, wherein the air inlet is a valve closed port and/or an injector, and the water inlet is an injector or atomiser.

14. The steam driven engine as in any one of the preceding claims, wherein 15 the means for heating the supply of water is an electric heater.

15. The steam driven engine as in any one of claims 1 to 13, wherein the means for heating the supply of water is a heat exchanger.

16. The steam driven engine of claim 16, wherein the heat exchanger utilises steam exhausted from the chamber to heat the supply of water prior to its 20 release into the chamber.

17. The steam driven engine as in either of claims 15 or 16, wherein supplementary heating of the air may be achieved by directing the air supply through the heat exchanger.

18. A method of operation for the steam driven engine as in any one of the 25 preceding claims, including the steps of releasing a supply heated air into the chamber, releasing a supply of heated water into the air, thereby creating steam, which then expands and drives the piston down. Amended Sheet IPEA/AU 11

19. The method of claim 28, wherein the air is compressed by the piston prior to the water being released therein.

20. A method of operation for the steam driven engine as in any one of the preceding claims, including the steps of releasing a supply heated air into the 5 chamber, compressing this supply of heated air with the piston, releasing a supply of heated, misted water into the chamber, and releasing a further supply of heated air into the supply of heated, misted water, the method creating steam which then expands and drives the piston down.

21. A method of operation for the steam driven engine as in any one of the 10 preceding claims, including the steps of releasing a supply of the heated air into the chamber, compressing this supply of heated air with the piston, releasing a supply of heated, misted water and a further supply of the heated air into the chamber simultaneously, the method creating steam, which then expands and drives the piston down. 15 22. . The method as in any one of the preceding method claims, wherein the method includes the further step of shutting off water and air supply to the chamber.

23. The method as in any one of the preceding method claims, wherein the method includes the further step of opening a valve to the exhaust port, and 20 allowing the piston to drive the vapour out of the chamber.

24. The method as in any one of the preceding method claims, wherein the method includes the further step of inducing a fresh charge of air by utilising the partial vacuum created by the downwardly traveling piston.

25. The method of claim 24, wherein a further-supply of the heated 25 compressed air is introduced into the chamber as the exhaust port is opened for the purpose of assisting evacuation of the vapour from the chamber.

26. A steam driven engine as described in the specification with reference to and as illustrated in the accompanying representations. Amended Sheet IPEA/AU 12

27. A method of operation for a steam driven engine as described in the specification with reference to and as illustrated in the accompanying representations. Amended Sheet IPEA/AU