WO2011029128A1

WO2011029128A1 - Turbine apparatus and method

Info

Publication number: WO2011029128A1
Application number: PCT/AU2010/000879
Authority: WO
Inventors: Mathew James Fletcher
Original assignee: Mathew James Fletcher
Priority date: 2009-09-09
Filing date: 2010-07-09
Publication date: 2011-03-17

Abstract

A turbine apparatus (20) is disclosed which comprises a container (27) for storing a solid fuel (21), a compressor (42) for compressing air, and a combustion chamber (26) for combusting the fuel (21) in the presence of compressed air from the compressor (42) such that ash produced by combusting the fuel (21) is able to be ejected from the chamber (26) while the fuel (21) is being combusted. A turbine (43) is coupled to the chamber (26) such that an exhaust gas produced by combusting the fuel (21) is able to drive the turbine (43). A fuel transfer mechanism (31) is able to transfer the fuel (21) from the container (27) to the chamber (26) while the fuel (21) is being combusted.

Description

TURBINE APPARATUS AND METHOD

Field of the Invention

The present invention relates generally to turbine apparatus and, in particular, to turbine apparatus that are powered by solid fuel and that are able to operate continuously.

Background Art

Internal combustion turbines presently being utilised require gaseous or liquid fuels which are primarily derivatives from crude oil, natural gas or extracted from coal. In addition, synthetic fuels have been developed which are of the liquid type.

A major drawback of such internal combustion turbines is the fact that the fuel which they use is derived from a limited and exhaustible supplies which with time will become so scarce that the expense of operating an internal combustion turbine will become prohibitive. The aforementioned drawback could be overcome to at least to some extent by using solid fuels instead of gaseous or liquid fuels to power internal combustion turbines.

There have been various attempts over the years to burn a variety of solid fuels in internal combustion turbines. The solid fuels which have been used in these attempts have included chopped-up wood and coal. At best, the attempts to date have been marginal or less than adequate.

An example of one such internal combustion turbine apparatus is disclosed in U.S. Pat. No. 985,793 (Fabel). The apparatus includes a combustion chamber which is fed with particulate solid fuel via a slide and chute. The apparatus is quite cumbersome and is subject to jamming and clogging. As a result, the apparatus is not adaptable for use with utilisation devices such as automobiles or trucks which require efficient, long-range operating characteristics.

Some attempts at using solid fuels to power internal combustion turbines have been based around batch gasification and pyrolysis technologies. The fuel is loaded into a large combustion chamber in a batch process. The fuel is then burnt in a low oxygen environment and the off gas is combusted within the turbine.

The principle disadvantages of using the aforementioned batch technologies are that the fuel cannot be introduced into the system in a metered and controlled fashion, and the spent fuel cannot be removed without stopping the process and waiting for it to cool down. The general result is a lot of un-burnt gas and smoke which is emitted from the turbine exhaust. The combustion chamber remains full of charcoal, and the spent charge needs to be manually removed before preparing another batch. The economics behind many of the attempts to date at using solid fuels to power turbines has prevented any real additional developments in this area.

The preceding discussion of the background to the invention is intended only to facilitate an understanding of the present invention. It should be appreciated that the discussion is not an acknowledgment or admission that any of the material referred to was part of the common general knowledge as at the priority date of the application.

Summary of the Invention

It is an object of the present invention to overcome, or at least ameliorate, one or more of the deficiencies of the prior art mentioned above, or to provide the consumer with a useful or commercial choice.

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, a preferred embodiment of the present invention is disclosed.

According to a first broad aspect of the present invention, there is provided a turbine apparatus comprising a container for storing a solid fuel, a compressor for compressing air, a combustion chamber for combusting the fuel in the presence of compressed air from the compressor such that ash produced by combusting the fuel is able to be ejected from the chamber while the fuel is being combusted, a turbine coupled to the chamber such that an exhaust gas produced by combusting the fuel is able to drive the turbine, and a fuel transfer mechanism for transferring the fuel from the container to the chamber while the fuel is being combusted.

In contrast to prior art turbine apparatus in which solid fuel and ash are respectively combusted in and removed from the apparatus in batches so that the apparatus is consequently unable to operate continuously, the turbine apparatus according to the present invention is able to operate continuously because its combustion chamber is able to eject ash while fuel is being combusted in the chamber, and because its fuel transfer mechanism is able to introduce solid fuel into the combustion chamber while fuel is being combusted in the chamber. Preferably, the container is pressurised so that the pressure inside the container and the pressure inside the combustion chamber are substantially the same.

It is preferred that the turbine apparatus also includes an air-lock for introducing solid fuel into the container. In a particular preferred form, the air-lock includes a chamber, a first valve for allowing solid fuel to be introduced into the chamber, and a second valve for allowing solid fuel to be removed from the chamber. The first valve and the second valve are preferably both slide valves.

The turbine apparatus may also include a hopper for introducing the solid fuel into the air-lock. The compressor may be any suitable type of compressor. For example, the compressor may be a centrifugal, diagonal, axial-flow, reciprocating, rotary screw, rotary vane, scroll, or diaphragm compressor.

In a particular preferred form, the compressor is driven by the turbine. In another particular preferred form, the turbine apparatus further comprises a motor, and the compressor is driven by the motor.

Preferably, the turbine apparatus also comprises a valve for varying the amount of air which is able to be compressed by the compressor. In a particular preferred form, the valve is a variable inlet guide vane. Preferably, the combustion chamber includes a wall, a combustion grate on which the fuel is able to be combusted, a first outlet for directing compressed air from the compressor on to the grate, an opening, a second outlet for introducing compressed air from the compressor into the chamber so as to create a vortex in the chamber, wherein the vortex is able to force ash in the chamber to move outwardly, strike the wall, and to then fall out of the chamber through the opening, and an intake for the turbine, wherein the intake is positioned such that the exhaust gas at the centre of the vortex is able to enter the intake.

The turbine apparatus may include a first valve for controlling the flow rate of the compressed air out of the first inlet. The turbine apparatus may include a second valve for controlling the flow rate of the compressed air out of the second inlet.

Preferably, the turbine apparatus also comprises a recuperator for heating the compressed air from the compressor using the exhaust gas.

It is preferred that the turbine apparatus also includes a hopper for collecting ash that is ejected from the combustion chamber.

The turbine apparatus may also include an ash transfer mechanism for transferring ash away from the combustion chamber. Preferably, the ash transfer mechanism includes a motorised auger.

Preferably, the turbine is a radial outflow, axial flow, or radial inflow turbine. ln a preferred form, the fuel transfer mechanism includes a motorised auger. The fuel transfer mechanism may also include a drop tube extending from the auger and into the combustion chamber.

The turbine apparatus may include an igniter for igniting the fuel in the combustion chamber. Preferably, the igniter is an electric heating rod.

Preferably, the turbine apparatus includes a waste gate for venting the exhaust gas.

It is preferred that the turbine apparatus also includes a water heater for heating water using the exhaust gas. Preferably, the turbine apparatus includes a utilisation device which is driven by the turbine. The utilisation device may, for example, be an electricity generator or a vehicle. If the utilisation device is an electricity generator, it is preferred that the turbine apparatus also includes a power management controller for controlling the electrical power which is generated by the electricity generator. The turbine apparatus may also include a hot oil heater for heating oil using the exhaust gas, a secondary turbine coupled to the heater such that the heated oil is able to drive the secondary turbine, an electricity generator driven by the secondary turbine, and a condenser for cooling the heated oil.

Preferably, the turbine apparatus also includes a spray nozzle for introducing demineralised water into the combustion chamber.

It is preferred that the apparatus also includes a cyclonic separator for removing fine particulate matter/material from the exhaust gas.

In a preferred form, the turbine is a high pressure turbine, and the apparatus also includes a generator and a low pressure turbine which is driven by exhaust gas from the high pressure turbine and which drives the generator.

According to a second broad aspect of the present invention, there is provided a method of powering a turbine apparatus with a solid fuel, the method comprising the steps of:

(i) storing a solid fuel in a container;

(ii) compressing air with a compressor; (iii) combusting the fuel in a combustion chamber in the presence of compressed air from the compressor such that ash produced by combusting the fuel is ejected from the chamber while the fuel is being combusted;

(iv) coupling a turbine to the chamber such that an exhaust gas produced by combusting the fuel is able to drive the turbine; and

(v) transferring the fuel from the container to the chamber while the fuel is being combusted.

According to a third broad aspect of the present invention, there is provided a solid fuel internal combustion turbine comprising a tank for storing particulate solid fuel therein. A combustion chamber is positioned proximate to the storage tank for receiving the solid fuel stored within. A combusting agent, such as oxygen with air, is controllably coupled to the combustion chamber under pressure to sustain the oxidation or combustion of the solid fuel therein. The exhaust from the combustion chamber, which is at a high temperature and pressure, is controllably coupled to a power turbine which in turn drives a compressor, an electrical generator or utilisation device such as a vehicle.

Preferably, the combusting fuel or oxidising air is compressed in an air compressor, which is driven by means of the power turbine which is also coupled to an electrical generator on a common shaft.

According to a fourth broad aspect of the present invention, there is provided a solid fuel internal combustion turbine comprising a pressurised tank for storing particulate solid fuel therein a pressurised cyclonic combustion chamber positioned near to the tank, the chamber including a combustion grate with automated cleaning rake and means for removing ash and particulate automatically, a means for controllably introducing combusting air directly into the solid fuel within the combustion grate and in direct contact with the solid fuel in the combustion zone so that a combustion area is formed within the combustion zone, an expansion turbine which is coupled to a compressor for controllably receiving exhaust gases from the combustion chamber, the power turbine driving a utilisation device. Preferably, the means for controllably conducting a combusting air to the combustion chamber comprises means for controlling the rate of rotation of the air compressor.

It is preferred that the solid fuel internal combustion turbine further comprises means associated with the compressor rate controlling means for controlling the input of the combusting air to the air compressor.

In a preferred form, the combusting air is oxygen.

The solid fuel is preferably selected from the group consisting of: wood pellets, biomass, processed tyres, and coal. It is preferred that the solid fuel has a moisture content of less than 10%.

Preferably, the means for controlling the power turbine includes at least one throttle for limiting the pressure of the exhaust gases entering the power turbine.

Advantageously, the solid fuel internal combustion turbine further comprises means for igniting the solid fuel in the combustion chamber when the turbine is started, the means including an electric heating element powered from an external source.

It is preferred that the solid fuel internal combustion turbine further comprises means for moving the solid fuel onto the combustion grate as the fuel is burnt therein. According to a fifth broad aspect of the present invention, there is provided a solid fuel internal combustion turbine comprising a separate fuel storage tank for storing solid fuel which utilises a series of valves mounted to the top of the tank for refilling the tank whilst the turbine is operating, a cyclonic combustion chamber that is closed at both ends with penetrations in the walls of the cylinder to introduce the pressurised combustion air into the cylinder in a vortex motion, a cyclonic combustion chamber that through cyclonic separation removes ash and particulate from the hot production gas, a perforated combustion grate positioned within and extending across the bottom wall of the cyclonic combustion chamber, a combustion area within the grate and an ash collection area there below, automated fuel feeding by means of an auger screw mounted on an angle which transfers solid fuel from the fuel storage tank to the combustion grate within the cyclonic combustor; supply means for controllably supplying combustion air solely to the combustion area by a nozzle positioned below the grate to thereby control the quantity of fuel actually being ignited, the supply means including a turbine driven or motor driven compressor for compressing the combustion air, the compressor turbine having an inlet and outlet, a conduit connecting the nozzle to the outlet of the compressor to a pre-heater so that the combustion grate and cyclonic chamber will receive adequate combustion air, control means for controlling the quantity of combustion air being compressed and discharged by the compressor, turbine drive means for driving the compressor, a conduit connecting the combustion zone with the turbine drive means so that the combustion exhaust gases can be conducted from the combustion zone to the power turbine means for controllably receiving the remaining portion of exhaust gases from the combustion area, the power turbine driving a utilisation device.

Preferably, the solid fuel internal combustion turbine further comprises relief valve means for relieving pressure within the tank.

The utilisation device may, for example, comprise an automobile, train, ship or truck.

It is preferred that the fuel feeding means for moving the solid fuel includes an inclined rotating screw auger mounted between the fuel storage tank and the cyclonic combustion chamber.

According to a sixth broad aspect of the present invention, there is provided a method for controlling the combustion of a solid fuel in a solid fuel internal combustion turbine in response to the operation of power output requirement, the method comprising the steps of:

(i) maintaining pressure on the solid fuel within the storage tank and continuously auguring the solid fuel toward and into the combustion zone; (ii) supplying combustion air into the combustion zone within the level of the grate supporting solid fuel;

(iii) controlling the quantity of fuel actually being ignited in the combustion grate by controlling the rate at which the combustion air is supplied to the combustion zone through the nozzle;

(iv) withdrawing of combustion gases produced from the centre of the combustor and directing that portion to a power turbine; and

(v) controlling the quantity of combustion gas withdrawn and directed through the turbine. Brief Description of the Drawings

The present invention will be farther explained with reference to the attached drawings, wherein like structures are referred to by like numerals throughout the several views. The drawings shown are not necessarily to scale, with emphasis instead generally being placed upon illustrating the principles of the present invention.

The invention will be better understood by reference to the following description of several specific embodiments thereof as shown in the accompanying drawings in which:

Figure 1 is a schematic diagram of a turbine apparatus according to a first preferred embodiment of the present invention;

Figure 2 is a schematic functional description diagram of the turbine apparatus depicted in figure 1 ;

Figure 3 is a schematic diagram of a turbine apparatus according to a second preferred embodiment of the present invention; Figure 4 is a schematic diagram of a turbine apparatus according to a third preferred embodiment of the present invention; Figure 5 is a schematic diagram of a turbine apparatus according to a fourth preferred embodiment of the present invention;

Figure 6 is a schematic diagram of a turbine apparatus according to a fifth preferred embodiment of the present invention; Figure 7 is a schematic diagram of a turbine apparatus according to a sixth preferred embodiment of the present invention; and

Figure 8 is a schematic diagram of a turbine apparatus according to a seventh preferred embodiment of the present invention.

Best Mode(s) for Carrying out the Invention In the drawings, like features have been referenced with like reference numbers.

Refer now to figure 1 where there is disclosed a simplified process flow diagram of a solid fuel combustion turbine apparatus 20 according to the first preferred embodiment of the present invention.

Wood pellets 21 are used to power the apparatus 20. Wood Pellets are an ideal fuel source since they can be regenerated by harvesting trees. The use of wood pellets in the present invention can be achieved easily as it is a manufactured fuel for combustion use. It should be understood, however, that other forms of solid fuel, such as, for example, coal, biomass, wood chips, or processed tyres, may be utilised in keeping with the present invention. The wood pellets 21 are loaded into a hopper 22. The pellets 21 enter an airlock 23 by opening a slide valve 24 of the air lock 23. Whilst slide valve 24 is opened, a slide valve 25 of the air lock 23 must be closed and vice versa to ensure that pressure within a cyclonic combustion chamber 26 of the apparatus 20 does not flow into a receiving tank 27 of the apparatus 20. Slide valve 25 opens to allow pellets or coal that are held in a chamber 28 of the air-lock 23 into the receiving tank 27. Apparatus 20 includes electronic density sensors 29, 30 which are able to respectively sense the density of the solid fuel 21 contained in the chamber 28 and tank 27 to ensure that the chamber 28 of the airlock 23 or the receiving tank 27 don't get over-filled. Once the solid fuel 21 is positioned within the tank 27 via air-lock refueling portal 23, it is reclaimed through an auger 31 which is driven by a motor M1. The reclaimed fuel 21 then passes through a drop tube 32 onto a combustion grate 33 in the combustion chamber 26.

The fuel 21 on the grate 33 is ignited initially by an electric heating rod 34. Once ignition is self-sustaining, electric heating rod 34 is switched off.

Pressure and temperature within the combustion chamber 26 are respectively measured by a pressure transmitter (PT) 35 and a temperature transmitter (TT) 36.

Ash is removed automatically from the combustion chamber 26 and the combustion grate 33 by an auger 37 which is driven by a motor M2.

Combustion grate 33 has a grate cleaner (not depicted) to keep the air passages through the grate 33 clear for combustion air to enter it from a control valve 38.

First off, combustion air enters the system/apparatus 20 through a variable inlet guide vane 39. Vane 39 also acts as a throttle and governor and meters air into the system according to the requirements of heat and power output as directed by the operator. Pressure transmitter (PT) 40 and temperature transmitter (TT) 41 measure ambient air temperature and pressure.

The air is drawn into compressor 42 where the air is compressed/pressurised. Compressor 42 is used to start a turbine 43. Compressed air is directed onto the blades of the compressor 42 to run the compressor 42 and the turbine 43 up to self-sustaining speed. Compressor 42 is directly coupled to turbine 43. It should be noted that compressor 42 can be driven by a separate means such as an electric motor which is not coupled to the turbine 43, and this method may be utilised in keeping with the present invention. It should also be noted that the system/apparatus 20 can utilise a turbine 43 which has a variety of turbine designs including radial outflow, axial flow, and radial inflow designs.

Pressurised air exits compressor 42 and enters recuperator 44. Recuperator 44 is used to scavenge exhaust gas heat from the turbine 43 whilst in simple cycle configuration. Pressure transmitter (PT) 45 and temperature transmitter (TT) 46 respectively measure the pressure and temperature of the compressed air which is discharged from the compressor 42. The pressurised warm air exits recuperator 44. Temperature transmitter (TT) 47 measures the temperature of the compressed air which exits from the recuperator 44, and a control system (not depicted) of the apparatus 20 calculates the difference (i.e. delta T) between the temperatures measured by a temperature transmitter (TT) 48 in the inlet of the recuperator 44 and the temperature measured by TT 47.

The control/check valve 38 modulates combustion air into combustion grate 33. A pressure transmitter (PT) 49 measures combustion grate air inlet pressure. Control/check valve 50 modulates cyclonic air into the combustion chamber 26. The function of the check valves 38, 50 is to ensure that hot gases cannot enter the discharge side of the compressor 42.

A pressure transmitter (PT) 51 measures cyclonic air pressure within the combustion chamber 26. The electronic control system manages the balance between combustion grate inlet air and cyclonic air within the combustion chamber 26.

Air discharging from valve 50 enters into combustion chamber 26 on a tangential angle. The air is heated within the combustion chamber 26. The action of the cyclonic air entering the combustion chamber 26 on a tangential angle is to create a vortex V within the chamber 26. The vortex V causes solid particles (i.e. ash) to be forced towards the walls of the chamber 26 so that they strike the walls and drop into an ash hopper 52 where they can then be removed by the auger 37. Pressurised hot gas is expelled from combustion chamber 26 through an inlet manifold of the turbine 43. The hot gas is expanded across the blades of the turbine 43 forcing it to rotate the turbine 43 which in turn rotates the compressor 42 and an electricity generator 53. The hot gas enters the inlet manifold of the turbine 43 from the centre of the vortex V within the combustion chamber 26. This is to minimise the amount of particulate that may pass through the turbine 43.

Hot gas waste gate 54 is used during starting and stopping of the system/apparatus 20. Waste hot gas is modulated through waste gate 54 and may be used as an emergency hot gas dump valve. The exhaust gas from turbine 43 passes through recuperator 44. Gas exits recuperator 44 and passes temperature transmitter (TT) 55 which measures the temperature of the exiting gas.

Turbine delta T is calculated as the differential between the temperature measured by a temperature transmitter (TT) 56 and the temperature measured by a temperature transmitter (TT) 57. TT 56 measures the temperature of the hot gas which enters the turbine 43. TT 57 measures the temperature of the hot gas which exits from the turbine 43.

An RPM sensor 58 monitors the rotational speed (i.e. rpm) of the shaft of turbine 43. Rotation of the generator 53 by the turbine 43 causes the generator 53 to generate electrical energy.

The hot exhaust gas from the recuperator 44 can then be utilised to further heat water or generate more electricity in a combined cycle mode or by utilising an Organic Rankine Cycle process. It should be noted that fuel efficiencies with the Solid Fuel Combustion Turbine in combined cycle mode will rival that of modern gas turbine combined cycle mode. The reason for this is that the energy from the solid fuel is being extracted from the primary combustion cycle and the waste heat is being re-used, as opposed to a traditional steam boiler system where the heat is used only once.

The foregoing describes the apparatus 20 operating in a "simple cycle" mode. In simple cycle mode the apparatus 20 will approach 30% efficiency, and uses the recuperator to regain some of the heat from the turbine exhaust. The foregoing also describes a method for utilising a manufactured fuel (i.e. wood pellets), which can be regenerated in a relatively short period of time, to power the turbine apparatus 20. Wood Pellets are a much denser fuel than wood. Wood Pellets have a density of 650kg/m3 compared to wood chips at 250kg/m3. The turbine apparatus 20 is also capable of operating or being powered by energy sources such as used tyres and coal which, although exhaustible, are in plentiful supply. In addition, bagasse, general refuse and camel dung could be considered as potential solid fuel sources for the apparatus 20.

It is another preferred object of the present invention to provide an internal combustion turbine apparatus for electrical power generation, locomotives and vehicles wherein solid fuel is utilised.

TECH SPECS - DENSIFIED BIOMASS WOOD PELLETS

Bulk Density: 650 - 700kg/M3

Moisture Content: 8.34%

Ash Yield: 0.41%

Dry Cal Value 20.1 MJ/Kg

Information from HRL Technologies Result Sheet 6/12/2007. TECH SPECS - SFCT TURBINE 10Kw - 3000Kw

Shaft Speed: 10Kw: 70,000 RPM 3000Kw: 20,000 RPM

Compression Ratio: 4:1

Heat Rate: 10 Kw: 14,400 MJ/Kwh 3000Kw: 12,800 Mj/Kwh Max P 3: 60 PSI

Max T 3: 1100'C

Max T 4 800'C

Max T 5 550'c

Fuel: Wood Pellets The following is a more detailed functional description of the operation of the apparatus 20 with reference to figure 2.

Pre Start Conditions:

Fuel system:

The Fuel Tank 27 needs to have sufficient fuel prior to starting. DT 2 is a Density Transmitter that assesses the amount of fuel that is in the fuel tank 27. DT_2 is a discrete input to a PLC (not depicted). Whilst in operation the fuel tank 27 will become depleted. DT_2 will signal this drop in fuel level in the fuel tank 27 and signal the PLC. DT_1 assesses the amount of fuel in the airlock 23 between the two knife gate valves 24, 25. A solenoid Valve SV_2 will open and allow fuel into the airlock 23. The discrete input signal from DT_1 signals the PLC that there is sufficient fuel in the airlock 23 and will close SV_2. SV_3 will open with permission from DT_2 to allow the fuel to pass from the airlock 23 into the main fuel storage tank 27. Whilst the system 20 is cold and under no pressure, both knife gate valves 24, 25 may open so as to quickly fill the fuel tank 27 if desired. Whilst in continuous operation, the fuel system will modulate SV 2 and SV_3 so that at least one valve 24, 25 will always be closed at any time. P_3 and P_4 will provide input to the PLC to inform it if there is pressure in the system 20 or not.

Turbine Lube Oil (TLO):

TLO_P (Pressure), TLO_T (Temperature) and TLO_L (Level) are the inputs for the Turbine Lube Oil System. TLO_P and TLO_T are analogue devices, whilst TLO_L is a discrete input. TLO_L will signal that there is sufficient oil in the TLO tank. TLO P signals that there is sufficient oil pressure in the system. TLO_T is for over temperature protection.

Permissives: TLO T = < 110 deg c

TLO_P = > 30 PSI

TLO L = ON

Air Starting System:

Instrument Air is forced into the compressor 42 to turn the turbine shaft to start the engine. IA_P is a pressure switch that signals that there is sufficient air to start the engine.

Starting Sequence:

When the operator desires to start the turbine 43, the operator will select "start" on a Human Machine Interface (HMI) which is not depicted. The control system will cycle through the "Pre Start Conditions". Once the pre-start conditions have been met, the following sequences occur.

VIGV, CGA, and CCA analogue linear positioners 39, 38, 50 will modulate 0 - 100%. CGA 38 will go to 25% open and CCA 50 will go to 0%. VIGV 39 will be 100% open. EGD (Exhaust Gas Dump) Valve Positioner 54 will cycle from open to close and back to open. It will remain open during the starting sequence. M2 and RV1 37 will cycle on and then off. It will remain off during starting.

VSD_1 M1 will start and then stop when DT_3 senses fuel in the screw auger 31. VSD_1 M1 will wait 3 seconds and then operate for 5 seconds. This will displace fuel from the auger 31 and it will fall down the fuel tube 32 and land on the combustion grate 33. HE_1 34 switched on. It will heat the fuel and it will begin to combust. T3_A, B, C, and D are type K thermocouples and will signal when the temperature within the combustor 26 reaches 50 deg C.

Solenoid Valve SV 1 will be energised and open. The Instrument Air will turn the compressor/turbine/generator shaft. The shaft speed is measured by N1 , and will increase to 10,000 RPM. Temperature and pressure within the combustor 26 will start to increase. UVFD (UV Flame Detector) 1 and 2 will provide a discrete input to the PLC to confirm ignition. When ignition is confirmed and (T3) is = or > 200 deg c, and (P3) is = or > than 7 PSI, the EGD valve 54 will close. The hot gas will now start to flow through the turbine 43. CCA valve 50 will start to open to allow a greater flow of Cyclonic Combustion Air into the turbine 43, and CGA valve 38 will open to 30% - 40% to increase the amount of combustion air flow through the combustion grate 33. N1 (the common shaft of the turbine 43, compressor 42 and generator 53) will start to ramp up to base idle of 20,000 RPM. When N1 is at 18,000 RPM, VIGV 39 will modulate and close to about 30% of open. SV 1 will close. Thermocouples T4 (turbine inlet) and T5 (turbine exhaust) will increase in temperature. P3 will rise to 40 PSI.

Now that the engine is running at base idle, HE_1 34 is turned off. The engine remains at base idle for 5 minutes whilst it warms up. The PLC will assess delta T between T4 and T5, and T5 and T6. The VIGV 39 will modulate open in incremental stage to increase or decrease engine RPM. If VIGV 39 opens 5% from the previous set point with no speed or power increase resulting, it is assumed that there is insufficient fuel on the combustion grate 33. VSD_1 M1 will operate for 10 seconds and then stop. After warm-up is complete, the operator selects the amount of power that they desire from the engine on the HMI. The power output of the engine is governed by the amount of air introduced through the compressor 42 and the amount of fuel 21 admitted to the combustion grate 33. When the operator desires an increase in power output, they will increase the set point on the HMI. Firstly, the VIGV 39 will start to open further until the desired set point is reached. If the VIGV 39 is opened 5% with no significant increase in power, VSD 1 M1 will operate for 10 seconds to introduce more fuel 21 into the engine. VIGV 39 will not open further until T3 thermocouples signify an increase in combustion temperature and P3 indicates an increase in pressure back to set point.

The modes of engine control are:

XNSD Speed Control

T5 Control

P3 Control It should be noted the all modes of control result in power, and that the control mode will be automatically selected by the PLC depending on preset parameters. It should be understood that climatic conditions and altitude conditions will alter the behaviour of each control mode.

XNSD control is the lower range control for the engine and is focused N1 shaft RPM (X).

T5 control measures turbine EGT (exhaust gas temperature). T5 control will not allow EGT to pass 550 deg c, so in effect, T5 control is in control of the engine when the EGT parameters are between 400 - 550 deg c.

P3 control measures combustor pressure. P3 is the maximal power control for the engine. P3 control will not normally be reached unless all of the following occur at the same time:

The turbine installation is less than 500 metres above sea level; The ambient air temperature is less than 3 deg c; The operator has selected maximum power output on the HMI.

P3 control is pressure control and controls the pressure within the combustor 26 to a maximum of 60 PSI as the blower/compressor 42 runs at a maximum of 4:1 compression ratio. The PLC is still monitoring T3 and T5. If the operator reduces the power demand P3 control will return to T5 control and then back to T3 control.

The above modes of control are tuned with tuneable PID set-point control loops. The upper parameters are locked out to prevent damage to the engine by incorrect tuning. The operator sets a MW output on the HMI and the control system decides what control it needs to operate under.

Stopping the engine:

When the operator wished to stop the engine, the operator presses "Stop" on the HMI. The VIGV 39 will start to close in as will the CGA 38 and CCA 50 actuators. The engine power output will start to decrease and temperature and pressures will also decrease. When the engine gets to zero power, the generator circuit breaker will open. The engine will then decrease in RPM speed to base idle 20,000 RPM. The engine will operate at base idle until all of the remaining fuel 21 is depleted. The deletion of fuel 21 will see a decrease in T3 temperature when T3 is = or < 250 deg c, EGD 54 will open to dump the remaining pressure in the combustor 26. SV 1 will open and Instrument Air will rotate the compressor shaft. SV_1 will remain open for 2 minutes in order to cool the combustor 26 and the turbine 43. SV_1 then closes.

When the engine is off, there will be no pressure, fuel or heat within the combustor 26.

Emergency Shutdown:

The engine will shutdown automatically under the following conditions: Electrical Generator Trip - reverse power, phase to phase, phase to earth faults, 86 G relay condition

Low P3 whilst operating within expected T3, T5 or P3 parameters. Assumes a ruptured combustor 26 or pipe.

High vibration

High TLO temperature

Low TLO pressure

Low TLO level

High T3 outside of normal operating parameters

High T4 outside of normal operating parameters

High T5 outside of normal operating parameters

High P3 outside of normal operating parameters

High NI

Position error VIGV

Position error CGA

Position error CCA

Position error EGD

Emergency stop button depressed

In an emergency stop situation, the following occurs simultaneously: Generator breaker Open

EGD Open

VIGV Shut

CGA Shut

CCA Shut

VSD_1 off

In summary, the solid fuel internal combustion turbine apparatus 20 has a pressurised fuel tank 27 for storing pelletised and processed solid fuel such as, for example, wood pellets, biomass, coal or processed tyres. The fuel should be less than 12% in moisture content to ensure clean combustion. Wood Pellets 21 are the preferred option because they are clean burning, easy to handle and produce only 0.5 ash once combusted.

A hopper 22, which is located above the tank 27, has a series of slide valves 24, 25 which act as an air lock for loading granulated solid fuel in the tank 27 whilst the apparatus 20 is in operation. At least one valve 24, 25 must remain shut whilst the other is open in order to retain pressure within the fuel tank 27.

The solid fuel is drawn out of the bottom of the solid fuel tank 27 and is transferred into the pressurised cyclonic combustion chamber 26 by way of a motorised auger 31 and drop tube 32. The auger 31 may be inclined or horizontal and is in keeping with the present invention. The pressurised cyclonic combustion chamber 26 is positioned near to the hopper tank 27 for receiving the solid fuel. The solid fuel is deposited onto a combustion grate 33 within the combustion chamber 26 which has combustion air entering into it from the underside to control and assist with combustion. Primary ignition of the solid fuel is initiated by an electric rod heater 34 within the base of the grate 33.

Combustion air enters the combustion chamber 26 at a tangent to the side wall of the combustion chamber 26 thus creating a cyclonic vortex V within the chamber 26. During the combustion process the ash and particulate are forced to the outer limits within the cyclonic combustor 26, and drop out into an ash collection hopper 52. The ash collection hoper 52 is automatically cleaned with an auger screw 37. The hot producer gases from the combustion chamber 26 are drawn from the less turbulent area at the center of the combustor 26 and vortex V. The combustion chamber exhaust gases are coupled to an expansion turbine 43 which in turn drives an air compressor 42 and generator 53 on the same shaft.

The compressor 42 is for forcing pressurised air into the combustion chamber 26. The air is drawn into the compressor 42 at ambient temperature. It is discharged from the compressor 42 and then enters a recuperator 44 for preheating the combustion air. The preheated compressed air serves as a combusting air for igniting and burning the wood pellets 21 or other solid fuel.

About 85% of the shaft power from the turbine/compressor shaft is used to drive an electrical generator 53 or other utilisation device.

Controlling the system includes a throttle 39 at the input to the compressor 42 to control the quantity of air flow into the combustion chamber 26 and hence control the rate at which the wood pellets 21 are combusted as well as the mass flow through the turbine 43. This in turn controls the temperature and pressure of the exhaust gases coupled to the expansion turbine 43 to thereby control the power output of the expansion turbine 43.

A turbine apparatus 20 according to a second preferred embodiment of the present invention is illustrated in figure 3. Apparatus 70 is similar to the apparatus 20. For clarity, some of the components of the apparatus 70 have been omitted from figure 3. Unlike the apparatus 20, apparatus 70 also includes a power management controller 71 for managing/controlling the electrical power which is generated by the generator 53. A turbine apparatus 80 according to a third preferred embodiment of the present invention is illustrated in figure 4.

Apparatus 80 is similar to the apparatus 70. However, unlike the apparatus 70, apparatus 80 also includes an electric motor 81 which is used to rotate the compressor 42 instead of the turbine 43 rotating the compressor 42 by a common shaft. The turbine 43 of apparatus 80 only drives the generator 53.

A turbine apparatus 90 according to a fourth preferred embodiment of the present invention is illustrated in figure 5.

Apparatus 90 is configured to operate in a combined cycle with an Organic Rankine Cycle "ORC" process, and is able to achieve an efficiency approaching 45%.

Apparatus 90 is similar to the apparatus 80 in that the compressor 42 of the apparatus 90 is driven by an electric motor 81 instead of a turbine 43. However, unlike the apparatus 80, the apparatus 90 does not include a recuperator 44 for pre-heating the compressed air output by the compressor 42. Instead, the compressed air is output directly from the compressor 42 to the combustion chamber 26. Also, the hot exhaust gases which are output from the turbine 43 of the apparatus 90 pass through a hot oil heater 91. Heat is transferred within the heater 91 from the exhaust gases to oil. The oil is heated to such an extent that it is able to drive or rotate a secondary turbine 92 which is part of the apparatus 90. Rotation of turbine 92 causes a secondary electricity generator 93 to rotate and generate electricity. After exiting the turbine 92, the heated oil then passes through a condenser 94 which cools the oil down. The cooled oil exits the condenser 94 before again passing through the heater 91 to repeat the cycle.

A turbine apparatus 100 according to a fifth preferred embodiment of the present invention is illustrated in figure 6.

Apparatus 100 is identical to the apparatus 100, except that apparatus 100 also includes a power management controller 71 for managing/controlling the electrical power which is generated by the generator 53.

A turbine apparatus 110 according to a sixth preferred embodiment of the present invention is illustrated in figure 7.

Apparatus 110 is similar to the apparatus 20, except that apparatus 110 includes a spray nozzle 111 mounted at the top of the combustion chamber 26 so that the nozzle 111 is able to introduce demineralised water (not depicted) into the chamber 26 to increase mass-flow through the turbine 43. In use, nozzle 111 is connected to a mineralised water supply (not depicted).

In addition, apparatus 110 includes a cyclonic separator 112 for removing fine particulate material from the gas stream which flows from the combustion chamber 26 to the turbine 43. The gas stream which flows into the separator 112 from the chamber 26 enters into the separator 112 on a tangential angle. The action of the gas stream entering the separator 112 on a tangential angle is to create a vortex W within the separator 112. The vortex W causes particulate material which is carried in the gas stream to be forced towards the walls of the separator 112 so that the material strikes the walls and fall through the bottom of the separator 112. The material is piped to the auger 37 which transfers the material along with the ash which falls out of the bottom of the chamber 26. The gas stream, minus the particulate material, then flows to the turbine 43 as before so that it causes the turbine 43 to rotate. The turbine 43 is a high pressure turbine and is coupled to the compressor 42 by a common shaft or axle so that rotation of the turbine causes the compressor 42 to rotate.

Cyclonic separator 112 may either be mounted externally of the combustion chamber 26 as depicted in figure 7, or it may be mounted internally within the combustion chamber 26.

Apparatus 110 also differs from the apparatus 20 in that the gas stream which is output from the turbine 43 is then fed to a low pressure turbine 92 rather than directly to the recuperator 44 as is the case with the apparatus 20. The gas stream which flows through the turbine 92 causes it to rotate. Turbine 92 is coupled to the generator 53 by a shaft so that rotation of the turbine 92 causes the rotor of the generator 53 to rotate so that electricity is generated by the generator 53.

A turbine apparatus 140 according to a seventh preferred embodiment of the present invention is illustrated in figure 8.

Apparatus 140 is similar to the apparatus 70 except that its turbine 43 is a high pressure turbine, and that it also has a low pressure turbine 92 which is connected to the output side of the turbine 43 so that the exhaust gas from the turbine 43 is able to cause the turbine 92 to rotate. The exhaust gas from the turbine 92 is fed to the pre-heater/recuperator 44 rather than the exhaust gas from the turbine 43.

Moreover, the generator 53 is coupled to the turbine 92 by a common shaft so that the turbine 92 is able to drive the generator 53 to produce electricity.

In the various preferred embodiments of the apparatus according to the present invention as herein described, it will be appreciated that the exhaust gas which is output from the combustion chamber 26 is channelled between the various components of the apparatus through which the exhaust gas passes by suitable conduits. Similarly, it will be appreciated that the compressed air which is output by the compressor 42 is channelled between the various components of the apparatus through which the compressed air passes by suitable conduits. The conduits may, for example, be pipes, hoses, or any suitable combination thereof.

The apparatus according to the present invention are able to combust renewable and non-renewable sold fuels in a direct and continuous internal combustion process. The apparatus converts heat energy from the combusted solid fuel into rotational shaft energy using a turbine. The rotating turbine is able to drive an electrical generator or other utilisation device. The apparatus may operate in either "simple cycle", "combined cycle" or "combined heat and power" modes with the capacity to use the final exhaust gas to heat water or process air. It will be appreciated by those skilled in the art that variations and modifications to the invention described herein will be apparent without departing from the spirit and scope thereof. The variations and modifications as would be apparent to persons skilled in the art are deemed to fall within the broad scope and ambit of the invention as herein set forth. Throughout the specification and claims, unless the context requires otherwise, the word "comprise" or variations such as "comprises" or "comprising", will be understood to imply the inclusion of a stated integer or group of integers but not the exclusion of any other integer or group of integers.

Throughout the specification and claims, unless the context requires otherwise, the term "substantially" or "about" will be understood to not be limited to the value for the range qualified by the terms.

Claims

CLAIMS:

1. A turbine apparatus comprising a container for storing a solid fuel, a compressor for compressing air, a combustion chamber for combusting the fuel in the presence of compressed air from the compressor such that ash produced by combusting the fuel is able to be ejected from the chamber while the fuel is being combusted, a turbine coupled to the chamber such that an exhaust gas produced by combusting the fuel is able to drive the turbine, and a fuel transfer mechanism for transferring the fuel from the container to the chamber while the fuel is being combusted.

2. The turbine apparatus of claim 1 , wherein the container is pressurised so that the pressure inside the container and the pressure inside the combustion chamber are substantially the same.

3. The turbine apparatus of claim 2, wherein the apparatus also includes an air-lock for introducing solid fuel into the container.

4. The turbine apparatus of claim 3, wherein the apparatus also includes a hopper for introducing the solid fuel into the air-lock.

5. The turbine apparatus of any one of the preceding claims, wherein the compressor is driven by the turbine.

6. The turbine apparatus of any one of claims 1 to 4, wherein the apparatus further comprises a motor, and the compressor is driven by the motor.

7. The turbine apparatus of any one of the preceding claims, wherein the apparatus also comprises a valve for varying the amount of air which is able to be compressed by the compressor.

8. The turbine apparatus of any one of the preceding claims, wherein the combustion chamber includes a wall, a combustion grate on which the fuel is able to be combusted, a first inlet for directing compressed air from the compressor on to the grate, an outlet, a second inlet for introducing compressed air from the compressor into the chamber so as to create a vortex in the chamber, wherein the vortex is able to force ash in the chamber to move outwardly, strike the wall, and to then fall out of the chamber through the outlet, and an intake for the turbine, wherein the intake is positioned such that the exhaust gas at the centre of the vortex is able to enter the intake.

9. The turbine apparatus of claim 8, wherein the apparatus also comprises a first valve for controlling the flow rate of the compressed air out of the first outlet.

10. The turbine apparatus of claim 8 or 9, wherein the apparatus also comprises a second valve for controlling the flow rate of the compressed air out of the second outlet.

11. The turbine apparatus of any one of the preceding claims, wherein the apparatus also comprises a recuperator for heating the compressed air from the compressor using the exhaust gas.

12. The turbine apparatus of any one of the preceding claims, wherein the apparatus also comprises a hopper for collecting ash that is ejected from the combustion chamber.

13. The turbine apparatus of any one of the preceding claims, wherein the apparatus also comprises an ash transfer mechanism for transferring ash away from the combustion chamber.

14. The turbine apparatus of any one of the preceding claims, wherein the apparatus also comprises an igniter for igniting the fuel in the combustion chamber.

15. The turbine apparatus of any one of the preceding claims, wherein the apparatus also comprises a waste gate for venting the exhaust gas.

16. The turbine apparatus of any one of the preceding claims, wherein the apparatus also includes a water heater for heating water using the exhaust gas.

17. The turbine apparatus of any one of the preceding claims, wherein the apparatus also includes a utilisation device which is driven by the turbine.

18. The turbine apparatus of any one of claims 1 to 16, wherein the apparatus also includes a hot oil heater for heating oil using the exhaust gas, a secondary turbine coupled to the heater such that the heated oil is able to drive the secondary turbine, an electricity generator driven by the secondary turbine, and a condenser for cooling the heated oil.

19. The turbine apparatus of any one of the preceding claims, wherein the apparatus also includes a spray nozzle for introducing demineralised water into the combustion chamber.

20. The turbine apparatus of any one of the preceding claims, wherein the apparatus also includes a cyclonic separator for removing fine particulate matter from the exhaust gas.

21. The turbine apparatus of any one of claims 1 to 16, or claim 19 or 20, wherein the turbine is a high pressure turbine, and the apparatus also includes a generator and a low pressure turbine which is driven by exhaust gas from the high pressure turbine and which drives the generator.

22. A method of powering a turbine apparatus with a solid fuel, the method comprising the steps of:

(i) storing a solid fuel in a container;

(ii) compressing air with a compressor;

(iii) combusting the fuel in a combustion chamber in the presence of compressed air from the compressor such that ash produced by combusting the fuel is ejected from the chamber while the fuel is being combusted;

23. A turbine apparatus substantially as herein described with reference to figures 1 and 2; figure 3; figure 4; figure 5; figure 6; figure 7; or figure 8.

24. A method of powering a turbine apparatus with a solid fuel, the method being substantially as herein described with reference to figures 1 and 2; figure 3; figure 4; figure 5; figure 6; figure 7; or figure 8.

25. A solid fuel internal combustion turbine comprising a pressurised tank for storing particulate solid fuel therein, a pressurised cyclonic combustion chamber positioned near to the fuel tank including a combustion grate with automated cleaning rake and means for removing ash and particulate automatically, a means for controllably introducing combusting air directly into the solid fuel within the combustion grate by a nozzle located within the grate and in direct contact with the solid fuel in the combustion zone so that a combustion area is formed within the combustion zone, and an expansion turbine which is coupled to a compressor for controllably receiving exhaust gases from the combustion chamber, the power turbine driving a utilisation device.

26. The solid fuel internal combustion turbine of claim 25, wherein the means for controllably conducting a combusting air to the combustion chamber further comprises means for controlling the rate of rotation of the air compressor.

27. The solid fuel internal combustion turbine of claim 26 further comprising means associated with the compressor rate controlling means for controlling the input of the combusting air to the air compressor.

28. The solid fuel internal combustion turbine of claim 27, wherein the combusting air is oxygen.

29. The solid fuel internal combustion turbine of claim 28, wherein the solid fuel is selected from the group consisting of: wood pellets, biomass, processed tyres, and coal.

30. The solid fuel internal combustion turbine of claim 29, wherein the means for controlling the power turbine includes at least one throttle for limiting the pressure of the exhaust gases entering the power turbine.

31. The solid fuel internal combustion turbine of claim 30 further comprising means for igniting the solid fuel in the combustion chamber when the turbine is started, the means including an electric heating element powered from an external source.

32. The solid fuel internal combustion turbine of claim 31 further comprising means for moving the solid fuel onto the combustion grate as the fuel is burnt therein.

33. A solid fuel internal combustion turbine comprising a separate fuel storage tank for storing solid fuel which utilises a series of valves mounted to the top of the tank for refilling the tank whilst the turbine is operating, a cyclonic combustion chamber that is closed on both ends with penetrations in the walls of the cylinder to introduce the pressurised combustion air into the cylinder in a vortex motion, a cyclonic combustion chamber that through cyclonic separation removes ash and particulate from the hot production gas, a perforated combustion grate positioned within and extending across the bottom wall of the cyclonic combustion chamber, a combustion area within the grate and an ash collection area there below, automated fuel feeding by means of an auger screw mounted on an angle which transfers solid fuel from the fuel storage tank to the combustion grate within the cyclonic combustor; supply means for controllably supplying combustion air solely to the combustion area by a nozzle positioned below the grate to thereby control the quantity of fuel actually being ignited, the supply means including a turbine driven or motor driven compressor for compressing the combustion air, the compressor turbine having an inlet and outlet, a conduit connecting the nozzle to the outlet of the compressor to a pre-heater so that the combustion grate and cyclonic chamber will receive adequate combustion air, control means for controlling the quantity of combustion air being compressed and discharged by the compressor, turbine drive means for driving the compressor, a conduit connecting the combustion zone with the turbine drive means so that the combustion exhaust gases can be conducted from the combustion zone to the power turbine means for controllably receiving the remaining portion of exhaust gases from the combustion area, the power turbine driving a utilisation device.

34. An internal combustion turbine as in claim 33 further including relief valve means for relieving pressure within the tank.

35. An internal combustion turbine as in claim 34, wherein the utilisation device is selected from the group consisting of: an automobile, train, ship, and a truck.

36. An internal combustion turbine as in claim 35, wherein the fuel feeding means for moving the solid fuel includes an inclined rotating screw auger mounted between the fuel storage tank and the cyclonic combustion chamber

37. A method of controlling the combustion of a solid fuel in a solid fuel internal combustion turbine in response to the operation of power output requirement, the method comprising the steps of:

(i) maintaining pressure on the solid fuel within the storage tank and continuously auguring the solid fuel toward and into the combustion zone;

(ii) supplying combustion air into the combustion zone within the level of the grate supporting solid fuel;

(v) controlling the quantity of combustion gas withdrawn and directed through the turbine.