WO2003038347A1

WO2003038347A1 - Portable air heater and electric power generator with compressor/turbine unit

Info

Publication number: WO2003038347A1
Application number: PCT/CA2002/001621
Authority: WO
Inventors: Luiz Claudio Vieira Fernandes
Original assignee: Individual
Current assignee: Individual
Priority date: 2001-11-01
Filing date: 2002-10-31
Publication date: 2003-05-08
Anticipated expiration: 2004-05-01
Also published as: CA2362537A1

Abstract

Apparatus with compressor/turbine unit for providing clean hot air and/or electric power. In the combustion cycle, combustible is burned in a combustor. The hot exhaust gases provide heat to a process air cycle via a heat exchanger. Remaining thermal energy can be discharged by an 'air-atmospheric air heat exchanger'. In the process air cycle, cold air flows through a compressor, is heated via the above mentioned heat exchanger and after this expands in a turbine. Turbine and compressor are coupled together on a single shaft. The remaining pressure of the air stream propels an air motor that drives a fan and a generator unit to produce electric energy. The fan mixes hot process air and cold secondary air and provides the mixed air to any place where it is used. Instead of the fan an ejector can be used.

Description

PORTABLE AIR HEATER AND ELECTRIC POWER GENERATOR WITH COMPRESSOR/TURBINE UNIT

5 BACKGROUND:

Indirect self-powered portable air heaters are available in the market for a long time. Traditionally they use either an internal combustion piston engine or an electric motor to drive a fan that supplies air for both combustion and process.

10 Heaters using internal combustion piston engines will only depend on the fuel as the only source of energy, so that, they can be used in remote regions. However, due to the size of this engine, they tend to be bulky, heavy and complex to operate and maintain. Electric driven heaters are less complex but depend not only on the fuel as energy source but also on external power supply. That limits its ability to

15 be operated in remote regions. More recently, the use of thermoelectric driven heaters, open the possibilities of using electric driven fans in remote regions since a small fraction of the heat released in the combustion is converted into electricity in the thermoelectric devices. However, thermoelectric heaters are costly, subject to thermal cycle problems in their thermoelectric system and still present a power

20 limitation on the ability to pump enough combustion and process air. This invention, using both concepts of a combustor and turbocharger, uses the advantages of a heat engine, similar to the benefits of an internal combustion piston engine but without the limitations and drawbacks of being complex and relatively costly to maintain. Additionally, it provides a much larger operational range for both combustion and

25 process air due to the flexibility of both the turbocharger and the combustor. Part of the system can operate in a traditional gas turbine open cycle or in an external heated gas turbine cycle where the gas turbine is replaced by the turbocharger plus combustor plus the necessary system that extracts thermal and mechanical energy. DETAILED DESCRIPTION OF THE INVENTION:

The invention is shown in 3 different basic diagrams with some alternative configurations. All 3 basic configurations use a turbocharger as the central component of the portable air heater/ electrical generator. The idea behind is that the turbocharger provides mechanical power, in form of pressure and velocity, to the process air. This mechanical power can be used to drive a fan and also the combustion system, if necessary. It can also deliver electrical power for external applications. Figure 1 shows the turbocharger system (compressor + turbine components) where heat is provided by a heat exchanger. This heat exchanger also receives combustion gases from a combustor. The turbocharger runs purely in air. The process air coming out of the turbocharger can move a small air turbine/ air-motor or can be used to generate thrust in the fan through small air jets located in the fan blades. A generator is connected to the fan axle, and supplies power for a small oil pressure pump used to lubricate the turbocharger oil bearings. The dashed lines in all figures represent electrical power being delivered by the generator to the electrical motors of both oil pump and starting fan. Electricity has also sometimes provided to a specific so-called combustion fan, that provides combustion air for the combustor. The turbocharger can use air bearings instead of oil bearings. A small fan is used to pump air to both compressor and combustor and the starting fan can be turned off once the turbocharger speed is higher than idle. The process air consists of two air streams: the first coming from the turbocharger and the second, called secondary air, originated either from the process fan movement or from the pumping action of a conventional air ejector system as shown on figure 1A. The secondary air stream also carries out some of the heat generated in the turbocharger components. The components that are used to extract energy from the turbocharger' s turbine outlet air are part of the so-called energy extractor system. Therefore, the energy extractor system can consist of an air turbine or air motor, a fan driven by process air jets or an air ejector plus an electrical generator attached to the shaft. Figure 2, shows a different diagram where the combustor receives some combustion air from the turbine outlet. The rest of the system is similar from the one discussed on figure 1. The main differences between the 2 concepts shown between figures 1 and 2 are: system 1, shown on figures 1 and 1A, uses the combustor receiving air from a blower; system shown on figure 2 uses some pressurized air from the turbocharger that delivers a high efficient heat transfer process in the heat exchanger. Auxiliary air can also be induced in the combustor by the turbine pressurized air. On both systems used on figures 1 and 2, the fuel can be relatively easy supplied to the combustor, since the combustor air pressure is relatively close to the atmosphere. A derivation from Fig.2 is shown on Fig.2A, which is more suitable for electricity generation. In this figure, all turbocharged delivered hot air is directed to an air motor that produces some mechanical power that can be used to drive an electrical generator. After the air expands in the air motor, it is re-heated in a combustor that raises its temperature to values above the turbine inlet air temperature. The gas-air heat exchanger heats the air coming from the turbocharger' s compressor and the combustion gases leave the heat exchanger at lower temperatures. An auxiliary air-atmospheric air heat exchanger is used to provide heat to the surroundings. In this case, the process fan induces the surrounding air. Figure 2B shows a similar configuration but with the difference that all turbine air flows to the energy extractor system, in this case represented by an air-motor. Once it expands in the air motor releasing some mechanical energy, it flows to a so-called combustor heat exchanger, where the combustion gases transfer their thermal energy without being in contact to the process air coming from the air motor. Therefore, the heat exchanger that supplies heat to the process air works with the same process air with no combustion gases being mixed whatsoever. The process air that leaves the heat exchanger can be used externally as hot pure air. In figure 2B it expands in air ejector, creating a surrounding secondary air that simultaneously increases the total process air mass flow decreasing the process air temperature. The combustor air is supplied by a combustor air fan and after leaving the combustor heat exchanger it can release some of its remaining thermal energy to the process air through an air-atmospheric air heat exchanger. Figure 2C has a difference from figure 2B in which the process air that leaves the air-air heat exchanger returns back to the compressor inlet, resulting in a closed loop air system. In this case, the only hot air to be delivered outside the system is the one induced by the process fan. This air will be heated by the air-atmospheric air heat exchanger. This configuration is well suited where electricity generation is an important energy output need. Figure 3 shows a different schematic for the portable air system: a combustor is located in between the compressor and turbine, and combustion gases will expand against the turbine. After that the combustion gases will further expand in an air motor that drives both an electrical generator and a fan, called process fan. The combustion gases leave the air motor and release their thermal energy in an air-atmospheric air heat exchanger that will heat air induced by the process fan. Electricity and heat can be simultaneously generated. In this configuration, a pulse combustor is used as the system combustor, and illustrated the possibility of reducing or eliminating the necessary kinetic energy that is required by the combustion air. Because the air supplied to the combustor is pressurized coming from the compressor outlet, the fuel might also have to be pressurized, demanding a dedicated fuel pump in the system. Ideas shown on figures 1 and 2 are as equally complex, but with the unique application of providing high-pressure processed air, which makes the air heater application much more versatile. Figure 3A differentiates from figure 3 because there is no need for any heat exchanger in the system. Instead, an air motor will provide mechanical and/or electrical power to and outside the system and a process fan or ejector will pump surrounding air to the combustion gases. In this application, the heated air that leaves the system has some fraction of combustion gases. All systems shown on Figs. 1, 1A, 2, 2A, 2B, 2C, 3 and 3 A can also produce excess electricity in the generator part, so that the system can also be used as well as an electrical generator.

Claims

CLAIMS:I claim:

1. A combustor/ turbocharger air heater methodology/ system comprising: turbocharger means a commercial compressor/ gas turbine system connected by a single shaft; process air means the delivery air provided by said turbocharger means that can be used in different applications that require hot air flow; combustor means for high temperature combustion of any kind of fuel that provides heat to air to said turbocharger being either of steady or non-steady flow characteristics; combustor heat exchanger means a combustor in which burned gases provides thermal energy to the said process air means through a heat exchanger without mixing the two gases; energy extractor means a device that receives mechanical energy from outlet gas or air in said turbocharger and transforms it into mechanical movement of either a solid part, denominated air motor or of another induced stream of air, denominated air ejector; process fan means a fan that pump said process air means to any external application that requires hot air; heat exchanger means a device that transfers thermal energy from one fluid to another without being in direct contact: air-air heat exchanger means the two fluids consists of compressed air, gas-air heat exchanger means one fluid is air and other consists of combustion gases and an air-atmospheric air heat exchanger means one fluid is compressed air or combustion gases and the other is air under atmospheric pressure; a lubricating system means a system necessary to lubricated the said turbocharger.

2. A system and method of using said turbochargers means mentioned in claim 1 as a prime moving device to be used in portable heaters that can produce their own mechanical/ electrical power, i.e., self-powered heaters.

3. The use of said turbocharger means mentioned in claim 1 and 2 which is used to transfer energy from said process air means mentioned in claim 1 to the said energy extractor device also mentioned in claim 1.

4. The said energy extractor means mentioned in claim 1 and claim 3 used as an air motor can produce electricity to be supplied not only internally to the system but also externally to any application that requires electrical power.

5. The air motor mentioned on claim 4 can have either a rotor with blades that receive momentum from the said process air means mentioned in claim 1 producing a positive torque. This air motor can also consist of a typical cylinder- piston-crankshaft mechanism where this process air expands producing a positive net work against the piston and consequently the crankshaft.

6. The energy extractor mentioned in claim 4 can also induce a secondary air flow coming from the outside environment that is mixed with the said process air means mentioned in claim 1 for any application that requires hot air flow. This particular energy extractor can use of a fan where its blades have nozzles where the pressurized process air expands creating air jets that can produce a positive torque against the fan rotor. This torque drives the said process fan means mentioned in claim 1 that can consequently induce the secondary air. A similar mechanism of inducing a secondary air stream can be obtained adopting a typical air ejector system, where the primary air is the said process air means mentioned in claim 1 that provides energy to create the secondary air flow. In these two cases described in this paragraph, the primary and secondary flow will mix so that the resulting temperature of the total air stream will be increased due to the hot primary air flow.

7. A methodology and system of using a said turbocharger means mentioned in claim 1 that has an external heat source that can deliver high temperature and high-pressure said process air means mentioned in claim 1 for different applications. This process air released at the exit of the said energy extractor means mentioned in claim 1 can be at least one order of magnitude higher than the pressure achieved by conventional fan heaters.

8. A methodology and system of obtaining the said process air means mentioned in claim 1 where all the air flow after passing to the said gas-air heat exchanger means mentioned in claim 1 located in between the compressor and the turbine of the said turbocharger means mentioned in claim 1 leaves the turbine and have its flow split in two streams. One air flow stream goes to the said combustor means mentioned in claim 1 to assist the combustion process of the fuel. The combustion gases will flow through the mentioned gas-air heater heat exchanger, providing heat to the outlet compressor process air. After that it can pass to a simple said air- atmospheric air heat exchanger means mentioned in claim 1 where surrounding air can be heated and used to any external application. The said energy extractor means mentioned in claim 1 can provide energy to a fan or an air ejector that can move this heated surrounding air. The energy extractor will also provide not only internal electricity for the system itself but also to a required electrical demand for any external application.

9. A methodology and system of obtaining the said process air means mentioned in claim 1 where all the flow after passing to the said gas-air heat exchanger means mentioned in claim 1 located in between the compressor and the turbine of the said turbocharger means mentioned in claim 1 leaves the turbine and goes to the said energy extractor means mentioned in claim 1 releasing some mechanical energy. After that it flows to the said combustor means mentioned in claim 1 to provide air to the combustion process. The combustion gases from this combustor will flow through the said gas-air heat exchanger means mentioned in claim 1 providing thermal energy to the process air that leaves the turbocharger compressor. After that it can pass to a said simple air-atmospheric air heat exchanger means mentioned in claim 1 where surrounding air can be heated and used to any external application. The said energy extractor means mentioned in claim 1 can provide energy to a fan or an air ejector, in this last case releasing some process air flow, that can move this heated surrounding air. The energy extractor will also provide not only internal electricity for the system itself but also to a required electrical demand for an external application.

10. A methodology and system of obtaining the said process air means mentioned in claim 1 where all the flow after passing to the said gas-air heat exchanger means mentioned in claim 1 located in between the compressor and the turbine of the said turbocharger means mentioned in claim 1 leaves the turbine and goes to the said energy extractor means mentioned in claim 1 releasing some mechanical energy. After that it flows to the said combustor heat exchanger means mentioned in claim 1 to receive thermal energy form the combustion gases. The process air continues to flow through the said gas-air heat exchanger means mentioned in claim 1 providing thermal energy to the process air that leaves the turbocharger compressor. After that the process air can be released to provide hot air to any external application that also requires pressurized air. At this stage the combustion gases can pass to a said air-atmospheric air heat exchanger means mentioned in claim lthat releases some of its remaining thermal energy to the process air. The said energy extractor means mentioned in claim 1 can provide energy to a fan or an air ejector, in this last case releasing some process air flow, that can join the flow of the mentioned process air released. The energy extractor will also provide not only internal electricity for the system itself but also to a required electrical demand for any external application.

11. A methodology and system of obtaining the said process air means mentioned in claim 1 where all the flow after passing to the said gas-air heat exchanger means mentioned in claim 1 located in between the compressor and the turbine of the said turbocharger means mentioned in claim 1 leaves the turbine and goes to the said energy extractor means mentioned in claim 1 releasing some mechanical energy. After that it flows to the said combustor heat exchanger means mentioned in claim 1 to receive thermal energy from the combustion gases. The process air continues to flow through the said gas-air heat exchanger means mentioned in claim 1 providing thermal energy to the process air that leaves the turbocharger compressor. After that the process air can flow back into the system through the compressor of the said turbocharger means mentioned in claim 1. Therefore, in this claim, the process air circulates in the system in a closed loop, where the only mechanical energy released by the system happens in the said energy extractor means mentioned in claim 1 either as mechanical or electrical energy. A said process fan means mentioned in claim 1 driven by the energy extractor can provide a flow for the surrounding air. At this stage the combustion gases 25 can pass to a heat exchanger that releases some of its remaining thermal energy to this flow of surrounding air. The energy extractor will also provide not only internal electricity for the system itself but also to a required electrical demand for any external application.

12. A methodology and system of obtaining high temperature and moderate air pressure to a said process air means mentioned on claim 1 using the said turbocharger means mentioned in claim 1 where the process air is heated directly by a said combustor means mentioned in claim 1 located in between the compressor and turbine of the said turbocharger means mentioned in claim 1. In this case the process air at the turbine exit will flow to the said energy extractor means mentioned in claim 1 producing mechanical power and electricity for the system itself and for external applications. Also the energy extractor can drive a fan that will induce a surrounding air flow that can pass though a said gas-air heat exchanger means mentioned in claim 1 that will also receive the combustion gases of the mentioned combustor. The combustion gases will provide thermal energy to the surrounding air flow that can be used for applications that require hot air flows.

13. A methodology and system of obtaining high temperature and pressure air to a said process air means mentioned on claim 1 using said turbocharger means mentioned in claim 1 where the process air is heated directly by a said combustor means mentioned in claim 1 located in between the compressor and turbine of the said turbocharger means mentioned in claim 1. In this case the process air at the turbine exit will flow to the said energy extractor means mentioned in claim 1 producing mechanical power and electricity for the system itself and for external applications. Also the energy extractor can drive a fan or ejector that will induce a surrounding air flow that can be mixed with the high pressure and temperature process air. In this case, the combustion gases will provide thermal energy to the surrounding air by direct mixing and the resulting hot air flow can be used for applications that require hot air flows.

14. A methodology and system using a said turbocharger means mentioned in claim 1 capable of producing high temperature and pressure said process air means mentioned at claim 1 in a very compact and portable system. It uses a novel concept of using a portable commercial turbocharger device to produce this hot air stream. It will also produce electricity from said energy extractor means mentioned in claim 1 that can be used by the system components themselves and the excess electrical energy can be used for external applications.

15. A methodology and system mentioned on claim 4 that is also capable of producing its own mechanical/ electrical power. The only source of energy in this system is an external heat source that can be obtained by fuel burning or any waste heat.

16. A methodology and system mentioned on claim 4 that is also capable of heating water, ethylene glycol or any other fluid that needs to be heated. In this case, the heat exchanger used is a gas-liquid type.