Generating electrical energy from hydrogen and oxygen

Abstract

A device and method for generating electrical energy from hydrogen and oxygen, includes a combustion engine, a heat recovery steam generator connected into the exhaust gas duct of the combustion engine, wherein the heat recovery steam generator has only one pressure stage. An H.sub.2O.sub.2 reactor is provided to which steam from the heat recovery steam generator, water, oxygen and hydrogen are fed, such that, in the H.sub.2O.sub.2 reactor, a reaction of oxygen and hydrogen forms steam, the water that is introduced is evaporated, additional steam is generated, the resultant superheated steam is fed to a steam turbine, and a generator connected to the steam turbine provides an electric power. High-pressure feed water is injected from the heat recovery steam generator into the H.sub.2O.sub.2 reactor via a line to control the reaction in the H.sub.2O.sub.2 reactor in a targeted manner and set the steam exit temperature from the H.sub.2O.sub.2 reactor.

Claims

1. An apparatus for generating electrical energy from hydrogen and oxygen, comprising: an internal combustion engine, and a waste heat steam generator (WHSG) connected to an exhaust gas duct of the internal combustion engine, where the waste heat steam generator has only one pressure stage, an H2-O2 reactor, which is fed with WHSG steam from the waste heat steam generator, high-pressure feed water from the waste heat steam generator, oxygen and hydrogen, wherein in the H2-O2 reactor a reaction of oxygen and hydrogen produces additional steam and the high-pressure feed water evaporates into further steam, wherein the WHSG steam, the additional steam, and the further steam together form a greatly superheated steam that is fed to a steam turbine, and a generator connected to the steam turbine provides an electrical power, wherein, for control of the reaction in the H2-O2 reactor and for adjustment of a steam exit temperature from the H2-O2 reactor, the high-pressure feed water from the waste heat steam generator is sprayed into the H2-O2 reactor via a feed water conduit, wherein all WHSG steam exiting the waste heat steam generator is uncooled enroute to the H2-O2 reactor, and wherein expanded steam exits the steam turbine and is condensed before reaching the waste heat steam generator.

2. The apparatus as claimed in claim 1, further comprising: a heat remover designed as a heat exchanger which is connected on a primary side to a steam conduit that connects the steam turbine to a condenser disposed downstream of the steam turbine, and which is connected on a secondary side to the feed water conduit.

3. The apparatus as claimed in claim 1, further comprising: a condensate preheater connected upstream of the waste heat steam generator and configured to preheat the feed water, wherein steam is withdrawn from one or more taps on the steam turbine and is fed to the condensate preheater.

4. The apparatus as claimed in claim 1, wherein an evaporation pressure in the waste heat steam generator is set only sufficiently high that, depending on a fresh steam temperature set via the H2-O2 reaction, wetness at an exit from the steam turbine is avoided even without intermediate superheating.

5. The apparatus as claimed in claim 1, further comprising: an electrically operated superheater which is connected upstream of the H2-O2 reactor and downstream of the waste heat steam generator, and by means of which a fresh steam temperature of the steam when the H2-O2 reactor is not in operation is increased to such an extent that wetness is avoided at an exit from the steam turbine.

6. The apparatus as claimed in claim 1, wherein the waste heat steam generator has heating surfaces that form a first evaporator and a second evaporator, and heating surfaces that form a first superheater, wherein the first superheater is disposed between the heating surfaces of the first evaporator and of the second evaporator, so as to avoid any potential delay on startup of the internal combustion engine.

7. The apparatus of claim 1, wherein the internal combustion engine comprises a gas turbine.

8. The apparatus of claim 1, wherein the H2-O2 reactor is configured to control the reaction and to adjust the steam exit temperature of the H2-O2 reactor by injecting the high-pressure feed water directly into a combustion zone of the H2-O2 reactor.

9. A method of generating electrical energy from hydrogen and oxygen, comprising an internal combustion engine, a waste heat steam generator (WHSG) which is connected to an exhaust gas duct of the internal combustion engine and which has only one pressure stage, and an H2-O2 reactor, the method comprising: feeding the H2-O2 reactor with WHSG steam from the waste heat steam generator, with high-pressure feed water from the waste heat steam generator, with oxygen, and with hydrogen, wherein in the H2-O2 reactor a reaction of oxygen and hydrogen produces additional steam and the high-pressure feed water evaporates into further steam, and wherein the WHSG steam, the additional steam, and the further steam together form a greatly superheated steam that is fed to a steam turbine, and wherein all the WHSG steam exiting the waste heat steam generator is uncooled enroute to the H2-O2 reactor, feeding the greatly superheated steam to a steam turbine, condensing expanded steam that has exited the steam turbine before the expanded steam that has exited the steam turbine reaches the waste heat steam generator, and generating electrical power by a generator connected to the steam turbine, and controlling the reaction in the H2-O2 reactor and a steam temperature at an exit from the H2-O2 reactor by spraying the high-pressure feed water as water from the waste heat steam generator into the H2-O2 reactor via a feed water conduit.

10. The method as claimed in claim 9, further comprising: a heat remover designed as a heat exchanger to absorb heat which is connected on a primary side to a steam conduit that connects the steam turbine to a condenser disposed downstream of the steam turbine, in order, and which is connected on a secondary side to the feed water conduit, in order to release heat.

11. The method as claimed in claim 9, further comprising: a condensate preheater which is connected upstream of the waste heat steam generator and by which feed water is preheated, wherein, steam is withdrawn from one or more taps on the steam turbine and is fed to the condensate preheater.

12. The method as claimed in claim 9, wherein an evaporation pressure in the waste heat steam generator is set only sufficiently high that, depending on a fresh steam temperature set via the H2-O2 reaction, wetness at an exit from the steam turbine is avoided even without intermediate superheating.

13. The method as claimed in claim 9, further comprising: an electrically operated superheater which is connected upstream of the H2-O2 reactor and downstream of the waste heat steam generator, and by means of which a fresh steam temperature of the steam when the superheater is not in operation can be increased to such an extent that wetness is avoided at an exit from the steam turbine.

14. The method as claimed in claim 9, wherein the waste heat steam generator has heating surfaces that form a first evaporator and a second evaporator, and heating surfaces that form a first superheater, wherein the first superheater is disposed between the heating surfaces of the first evaporator and of the second evaporator, so as to avoid any potential delay on startup of the internal combustion engine.

15. The method of claim 9, wherein the internal combustion engine comprises a gas turbine.

16. The method of claim 9, wherein the H2-O2 reactor is configured to control the reaction and to adjust the steam temperature at the exit of the H2-O2 reactor by injecting the high-pressure feed water directly into a combustion zone of the H2-O2 reactor.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) The invention is described in detail hereinafter by figures. The figures show:

(2) FIG. 1: An apparatus of the invention for generation of electrical energy from hydrogen and oxygen

(3) FIG. 2: A collection of multiple developments of the apparatus of the invention

(4) FIG. 3: A development of the apparatus of the invention with separate preheaters

(5) FIG. 4: A development of the apparatus of the invention with a once-through steam generator

DETAILED DESCRIPTION OF INVENTION

(6) FIG. 1 shows the inventive apparatus 1 for generation of electrical energy from hydrogen and oxygen. The apparatus comprises a gas turbine 2, a waste heat steam generator 4 connected to the offgas duct 3 of the gas turbine, an H.sub.2O.sub.2 reactor 6 and a steam turbine 11. The gas turbine 2 and the waste heat steam generator 4 are conventional components. The gas turbine 2 may be fired wholly with hydrogen or partly with hydrogen and natural gas. The waste heat steam generator 4 is designed such that it has just one pressure stage 5 and delivers slightly superheated steam. The H.sub.2O.sub.2 reactor 6 can be fed with steam 7 from the waste heat steam generator 4, oxygen 8, hydrogen 9 and water 31 via separate conduits.

(7) The H.sub.2O.sub.2 reactor is designed such that a reaction of oxygen 8 and hydrogen 9 to give steam 10 is achievable therein. This reaction leads to the combustion product steam. The steam 10 is greatly superheated (with establishment of a permissible steam temperature by addition of steam 7 and water 31) and is fed to the steam turbine 11 via a steam conduit 10. The steam turbine 11 is connected to a generator 12 that can provide electrical power. The steam formed in the reaction of hydrogen and oxygen, which is at high pressure and temperature, is thus introduced into the steam circuit and can be exploited as circulation medium down to the level defined in the condenser. The better exploitation of heat allows the offgas temperature at the chimney exit to be lower. Use of hydrogen in the steam circuit allows the efficiency based on that mass flow of fuel to be very distinctly increased compared to use in the gas turbine.

(8) FIG. 2 shows multiple developments of the apparatus of the invention. The developments may be implemented here in combination or separately from one another.

(9) For control of the reaction and increase in power in the H.sub.2O.sub.2 reactor 6, feed water 13 from the waste heat steam generator 4 is injected into the H.sub.2O.sub.2 reactor 6 via a conduit 19. The feed water 13 may be here high-pressure feed water 14, which is advantageously withdrawn at the exit from the economizer 15 of the waste heat steam generator 4.

(10) To further increase the efficiency, a condensate preheater 20 is additionally provided in FIG. 2, upstream of the waste heat steam generator 4 for preheating of feed water 13. The condensate preheater 20 is heated with steam which is withdrawn from one or more taps 21 in the steam turbine 11.

(11) In order to be able to increase the fresh steam temperature of the steam if required (for example when the H.sub.2O.sub.2 reactor is out of operation) to such an extent that wetness is avoided at the exit from the steam turbine 11, an electrically operated superheater 22 is also provided in FIG. 2, upstream of the H.sub.2O.sub.2 reactor 6. The electrically operated superheater 22 makes it possible to ensure further operation of the H.sub.2O.sub.2 reactor even without hydrogen/oxygen supply.

(12) In order to avoid any potential delay on startup of the gas turbine 2, a superheater 27 is provided in FIG. 2, disposed between the heating surfaces 23 of the first evaporator 25 and of the second evaporator 26. This offers the advantage that the gas turbine 2 can always be started up at full gradient, even when the waste heat steam generator 4 is at ambient pressure and the superheater 27 is still dry and hence uncooled.

(13) FIG. 3 is based on the inventive design according to FIG. 1. FIG. 3 shows a development of the apparatus of the invention with separate preheaters 30 connected to taps on the steam turbine 11.

(14) FIG. 4 is based largely on FIG. 1. FIG. 4 shows a development of the apparatus of the invention with a once-through steam generator 16 and a heat remover 17. Given very highly selected fresh steam pressures and temperatures, it is advantageous to design the waste heat steam generator 4 as a forced circulation tank rather than as a natural circulation (drum) tank. The heat remover 17 is designed as a heat exchanger 18 which, for energy absorption, is connected on the primary side to the steam conduit 10 between the steam turbine 11 and a condenser 24 connected downstream of the steam turbine 11, and, for energy release, on the secondary side is connected to the conduit 19 for feeding feed water from the waste heat steam generator 4 into the H.sub.2O.sub.2 reactor 6. The heat remover 17 is required when the H.sub.2O.sub.2 reactor 6 generates very high fresh steam parameters of, for example, e.g. 1300 C. and pressure 150 bar. At the exit from the steam turbine 11, the steam is then still highly superheated, having been subjected to removal of heat by the heat remover 17, before it is condensed in the condenser 24.