WO2007104087A1

WO2007104087A1 - A steam driven engine

Info

Publication number: WO2007104087A1
Application number: PCT/AU2007/000292
Authority: WO
Inventors: David Ernest Ide
Original assignee: David Ernest Ide
Priority date: 2006-03-10
Filing date: 2007-03-08
Publication date: 2007-09-20
Also published as: CN101400946A

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

A STEAM DRIVEN ENGINE

TECHNICAL FIELD

The present invention relates to a steam driven engine, and in particular an internal steam generating engine, a system incorporating the engine, and a 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 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 invention therefore to provide a steam driven engine that substantially ameliorates the aforementioned difficulty, or at the least provides the public with a useful alternative to known steam driven engines.

Other objects and advantages of the present invention 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 present invention is disclosed.

DISCLOSURE OF THE INVENTION

In one form of this invention there is proposed a steam driven engine including a piston reciprocating in a chamber, and means to generate steam in the chamber to drive the piston. Preferably, the means to generate steam includes a means for heating a water supply, a means for heating an air supply, and a means for mixing the heated air and water in order to create the steam to drive the piston.

In a further form, the invention may be said to reside in a steam driven engine including a reciprocating piston, a means for heating a water supply, a means for heating an air supply, and a means for mixing the heated air and water in order to create the steam to drive the piston, at or near the piston face.

Preferably, the means for heating the air does so by pressurising the air.

Preferably, the means for heating the air does so by compressing the air.

Preferably, alternatively, the means for heating the air is the compressor of a turbo charger.

Preferably, alternatively, the means for heating the air is an air compressor.

Preferably, the air is heated to a temperature above the boiling temperature of the water.

Preferably, the means for preheating the water heats the water to a temperature approaching boiling temperature, but not to boiling temperature.

Preferably, alternatively, the means for preheating the water is an electric heater.

Preferably, alternatively, the means for preheating the water is a heat exchanger.

Preferably, the piston reciprocates within a chamber, the chamber including an air inlet, a water inlet, and a steam outlet.

Preferably, the heat exchanger utilises steam exhausted from the chamber to heat water prior to its release into the chamber. In a further form, supplementary heating of the air may be achieved by directing the air through this heat exchanger.

Preferably, the air and the water are mixed in the chamber.

Preferably, the air and water are mixed in the region directly above the piston in the chamber.

Preferably, the means for mixing the heated air and water releases the air into a mist of water to create steam.

In a further form, the means for mixing the heated air and water releases a mist of water into the heated air.

In a further form, the means of mixing the heated air and water releases these simultaneously.

Preferably, the steam outlet is a valve-closed port.

Preferably, the air inlet is a valve-closed port, and the water inlet is an injector.

Preferably, alternatively,_. the air inlet is an injector.

In a further form, the invention may be said to reside in a steam driven engine including a piston reciprocating in a chamber, wherein water and heated air are mixed in the chamber so as to generate steam, the generation of which drives the piston.

In a further form, the invention may be said to reside in a method of operation of the steam driven engine above, including the steps of releasing heated, compressed air into the chamber, releasing the heated, misted water into the air creating steam, which then expands and drives the piston down.

Preferably, the air is compressed by the piston prior to the water being released therein. In a further form the method includes the steps of releasing the heated, misted water into the chamber, releasing the heated, compressed air into the water creating steam, which then expands and drives the piston down.

In a further form the method includes the steps of releasing the heated, misted water into and the heated, compressed air into the chamber simultaneously, thereby creating steam, which then expands and drives the piston down.

preferably, the method further includes the step of shutting off water and air supply to the chamber.

Preferably, the method further includes the step of opening the valve to the exhaust port, and allowing the piston to drive the vapour out of the chamber.

Preferably, the method further includes the step of inducing a fresh charge of air and/or water by utilising the partial vacuum created by the downwardly traveling piston.

BRIEF DESCRIPTION OF THE DRAWINGS

For a better understanding of this invention it will now be described with respect to the preferred embodiment which shall be described herein with the assistance of drawings wherein;

Figure 1 is a schematic diagram of a system incorporating the engine and its ancillary equipment;

Figures 2 through 5 are schematic diagrams illustrating the operating cycle of the engine. in Figure 1 ; and

Figure 6 is a schematic diagram of a system incorporating the engine and its 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 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.

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 the water is heated to a temperature just below boiling temperature), and then a water atomiser/injector 28, which outlets the water as a fine mist into the chamber 8.

The air supply is drawn from atmosphere and passed through a sequence that includes an air filter 3O₁ 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, 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 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 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 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 puεhrods 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 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.

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), 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 components, drives the water vapour (air and steam mixture) out of the chamber 8. 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 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 compressor may be driven either directly or indirectly (in the case of an electric compressor) by the engine 1.

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 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 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 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 the appended claims so as to embrace any and all equivalent devices and apparatus.

Claims

1. A steam driven engine including a piston adapted to reciprocate within a chamber, and means for generating steam in the chamber to drive the piston.

2. The steam driven engine of claim 1 , wherein the means to generate steam includes a means for mixing a supply of heated water with a supply of heated air.

3. The steam driven engine of claim 2, wherein the means to generate steam mixes the supply of heated water and the supply of heated air in the chamber, at or near a face of the piston.

4. The steam driven engine of claim 3, wherein the means for mixing the supplies of heated air and water releases the heated air into a mist of the heated water so as to create the steam.

5. The steam driven engine of claim 3, wherein the means for mixing the supplies of heated air and water releases a mist of heated water into an atmosphere of the heated air so as to create the steam.

6. The steam driven engine of claim 3, wherein the means for mixing the supplies of heated air and water releases these into the chamber simultaneously so as to create the steam.

7. The stearrv driven engine as in any one of claims 2 to 6, wherein the supply of heated air has been heated to a temperature above the boiling temperature of the water.

8. The steam driven engine as in any one of claims 2 to 7, wherein the supply of water has been heated to a temperature approaching boiling temperature, but not to boiling temperature.

9. 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. The steam driven engine as in claim 9, wherein the steam outlet is a valve-closed port.

11. The steam driven engine as in claim 9, wherein the air inlet is a valve- closed port or an injector, and the water inlet is an injector or atomiser.

12. The steam driven engine as in any one of claims 2 to 1 1 , wherein there is included a means for heating the water supply, and a means for heating the air supply.

13. The steam driven engine of claim 12, wherein the means for heating the air does so by pressurising the air.

14. The steam driven engine as in either of claims 12 or 13, wherein the means for heating the air does so by compressing the air.

15. The steam driven engine as in any one of claims 12 to 14, wherein, the means for heating the air is the compressor of a turbo charger.

16. The steam driven engine of claim 12, wherein the means for heating the water is an electric heater.

17. The steam driven engine of claim 12, wherein the means for heating the water is a heat exchanger.

18. The steam driven engine of claim 17, wherein the heat exchanger utilises steam exhausted from the chamber to heat water prior to its release into the chamber.

19. The steam driven engine as in either of claims 17 or 18, wherein supplementary heating of the air may be achieved by directing the air supply through the heat exchanger. n

20. 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.

21. A method of operation for the steam driven engine as in any one of the preceding claims, including the steps of releasing heated air into the chamber, releasing the heated water into the air, thereby creating steam, which then expands and drives the piston down.

22. The method of claim 21 , wherein the air is compressed by the piston prior to the water being released therein.

23. A method of operation for the steam driven engine as in any one of the preceding claims, including the steps of releasing the heated, misted water into the chamber, releasing the heated air into the water creating steam, which then expands and drives the piston down.

24. A method of operation for the steam driven engine as in any one of the preceding claims, including the steps of releasing the heated, misted water into and the heated air into the chamber simultaneously, thereby creating steam, which then expands and drives the piston down.

25. 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.

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

27. 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 and/or water by utilising the partial vacuum created by the downwardly traveling piston.

28. A steam driven engine as described in the specification with reference to and as illustrated in the accompanying representations.

29. A method of operation for a steam driven engine as described in the specification with reference to and as illustrated in the accompanying representations.