Piston steam engine comprising a hydrogen boost device, combined heat and power plant comprising said piston steam engine, computer-implemented method for controlling the piston steam engine, and controller for controlling the piston steam engine

Abstract

The invention relates to a piston steam engine (1) having: at least one cylinder (10) which encloses a working chamber (15), a piston which can be moved back and forth in the working chamber (15) between a top dead center and a bottom dead center along a central axis of the cylinder, a steam chamber (76) for providing fresh steam, and an inlet valve (26) for controlling and / or regulating a fluid flow of the provided fresh steam, which functions as a working fluid of the piston steam engine, wherein the working chamber (15) is circumferentially enclosed by a working chamber wall (14) which is inserted into the cylinder (10) or is formed by same. The piston steam engine also has a hydrogen supply device (345) which is designed to introduce a specified quantity of hydrogen or a hydrogen-oxygen mixture into the working fluid and / or the residual steam of the piston steam engine in such a way that during the movement of the piston (30) from the top dead center (OT) to the bottom dead center (UT) or shortly before reaching the top dead center (OT), an explosive mixture, in particular a hydrogen-oxygen mixture, is provided, the (controlled) ignition of which can be used to increase the power output of the piston steam engine. The invention also relates to a combined heat and power plant comprising the steam engine (1), to a computer-implemented method for controlling and / or regulating a piston steam engine, to a computer program, and to a computer-readable storage medium.

Description

[0001] Piston steam engine with hydrogen boost device, a combined heat and power plant comprising the piston steam engine, a computer-implemented method for controlling the piston steam engine and a control system for controlling the piston steam engine

[0002] Technical area

[0003] The present disclosure relates to a piston steam engine with a hydrogen boost device (hydrogen charging device), in particular a piston steam engine that performs mechanical work using steam as a working medium. More specifically, the present disclosure relates to a piston steam engine that is preferably used to generate electricity. Furthermore, the present disclosure relates to a combined heat and power plant with the aforementioned piston steam engine, a computer-implemented method for controlling the piston steam engine, a controller for controlling the piston steam engine, a computer program, and a computer-readable storage medium.

[0004] background

[0005] Decentralized combined heat and power (CHP) plants have for some time now established themselves as an advantageous alternative to the conventional combination of local heating and a central power plant. CHP plants are used to generate electrical energy and obtain useful heat and are preferably operated on site or near the useful heat sink. Combustion engines such as diesel or gasoline engines, Stirling engines, steam engines, combustion turbines or steam engines can be used to drive the power generator. The use of steam engines, especially piston steam engines, has recently gained particular interest in CHP plants. This is primarily due to the high overall efficiency that can be achieved with low pollutant emissions and the almost free choice of liquid or solid fuel, such as wood, pellets, biogas or biomass.The high efficiency can be achieved with steam pressures of 30 bar to 800 bar, preferably 30 to 500 bar, and steam temperatures of 300 °C to 1000 °C, preferably 400 °C to 600 °C. Due to these advantages, piston steam engines are also used in smaller biomass power generation plants, waste heat power plants, waste incineration plants, and thermal afterburning plants.

[0006] In order to be able to operate the piston steam engine, in particular the reciprocating piston of the piston steam engine, efficiently with a sufficient amount of steam which is under a correspondingly high pressure and at a correspondingly high temperature, it is necessary to supply the pressurised steam / live steam (working fluid) to a working chamber of the piston steam engine in a very short time and with precise timing in order to be able to operate the working cycle of the reciprocating piston without disruptions (with smooth running). For this purpose, on the one hand, an inlet valve is necessary in order to be able to optimally control and regulate the fluid flow of the live steam to the working chamber of the piston steam engine. On the other hand, it is necessary to provide the required amount of steam at optimal operating parameters (pressure and temperature).

[0007] In the prior art, a generally known steam generator is used to generate the required live steam (working fluid). An example of such a steam generator is described in European patent application number 22 172 048 5, which comprises: a housing, a flow channel through which a heat exchange fluid, preferably flue gas, can flow from an inlet of the flow channel to an outlet of the flow channel, wherein at least a section of the flow channel is arranged in the housing as a first heat exchange element; at least one second heat exchange element arranged in the housing, through which water can flow to generate steam, a heat transfer medium which is arranged in the housing to transfer heat from the heat exchange fluid flowing through the flow channel to the water flowing through the second heat exchange element to generate steam, wherein the heat transfer medium is a salt bath.

[0008] By using a salt bath as a heat transfer medium, reliable operation can be ensured despite fluctuating energy content of the fuel mass of the steam generator, which uses, for example, biomass as an energy source.

[0009] Combined heat and power plants are often combined with other renewable energies, such as solar energy. However, solar energy can only be converted into electricity using relatively expensive technology and is only available to a limited extent or not at all depending on the time of day, year and weather. Furthermore, where the most energy is needed, conditions are usually unfavorable. On the other hand, wind can only be generated in a usable manner under suitable weather conditions and local circumstances, which means there is neither continuity nor predictability. The disadvantages mentioned have been known for a long time. For this reason, intensive research into new energy sources has been carried out for some time. The use of hydrogen is particularly promising in this regard. The main focus here is on the direct use of hydrogen to drive motor vehicles or turbines, for example.for electricity generation and for direct electricity generation in fuel cells, which is also used to power motor vehicles or for heating systems in buildings.

[0010] Despite all of hydrogen's undeniable advantages, it has so far failed to establish itself as an energy source. This is primarily due to the complex production of hydrogen using conventional processes, which generally involve electrolysis. Conventional electrolysis, however, requires a great deal of electrical energy. Therefore, the process is only profitable and ecologically sound if electricity is available that is both cheap and free of pollutants and carbon dioxide—i.e., produced using conventional renewable energies, which suffer from the disadvantages described above, which brings us back to the beginning of the problem.

[0011] Furthermore, as already described above, conventional renewable energy sources such as wind turbines, solar thermal systems, or photovoltaic systems are subject to strong fluctuations. This means that the available green electricity is subject to significant fluctuations and often has to be balanced with so-called gray electricity, which is generated, for example, from fossil fuels. The achievable energy prices on the electricity market are correspondingly volatile.

[0012] Subject of the invention

[0013] Accordingly, the object of the invention is to provide a piston steam engine which is capable, on the one hand, of further increasing the efficiency of highly developed piston steam engines, as have been developed recently, and thus of bringing them to the physical limits, and, on the other hand, of enabling maximum flexibility of the overall system, whereby external conditions such as load changes, available fresh steam temperature and / or flue gas temperature and / or thermally stored energy in the salt bath, availability of green electricity (green electricity), current electricity demand in the grid, the electricity price on the electricity market can be responded to quickly and, in particular, while maintaining efficiency.

[0014] This object is achieved by a piston steam engine according to claim 1 and a combined heat and power plant having the piston steam engine according to claim 22. The stated object is further achieved by a computer-implemented method according to claim 23, a controller according to claim 26, a computer program according to claim 27 and a computer-readable storage medium according to claim 28. Preferred developments of the invention are given in the dependent claims, wherein the subject matter of the claims relating to the piston steam engine can be used in the context of the combined heat and power plant, the computer-implemented method, the controller, the computer program and the computer-readable storage medium and vice versa.

[0015] One of the basic ideas of the present disclosure is to provide a piston steam engine which has a hydrogen boost device which is designed to introduce a predetermined amount of hydrogen or a hydrogen-oxygen mixture (oxyhydrogen gas) into the working fluid and / or the residual steam of the piston steam engine in such a way that during the movement of the piston from top dead center to bottom dead center, in particular shortly after top dead center or shortly before top dead center, an ignitable (explosive) mixture, in particular a hydrogen-oxygen mixture, is present, by the ignition of which the working output of the piston steam engine can be increased or increased.In this way, a piston steam engine can be provided which, in addition to the conventional working medium / fluid fresh steam, can also be operated with hydrogen plus air or a hydrogen-oxygen mixture, whereby on the one hand the power of the piston steam engine can be increased if required and on the other hand it can be reacted quickly and, in particular, with optimised efficiency to external conditions such as load changes, available fresh steam temperature and / or flue gas temperature and / or thermally stored energy in the salt bath, availability of green electricity (green electricity), current electricity demand in the grid, electricity price on the electricity market.

[0016] According to one aspect, a piston steam engine, which is preferably used for generating electrical power, has: at least one cylinder which encloses a working chamber, a piston which is movable back and forth in the working chamber between a top dead center and a bottom dead center along a central axis of the cylinder, a steam chamber for providing fresh steam, an inlet valve for controlling and / or regulating a fluid flow of the provided fresh steam which acts as the working fluid of the piston steam engine, wherein the working chamber is enclosed over its circumference by a working chamber wall inserted into the cylinder or formed by it, and a hydrogen boost device, comprising: a hydrogen supply device which is designed toIntroducing a predetermined amount of preferably pure hydrogen or a hydrogen-oxygen mixture (oxyhydrogen gas) into the working fluid and / or the residual steam of the piston steam engine in such a way that a flammable (explosive) mixture, in particular a hydrogen-oxygen mixture, is present during the movement of the piston from top dead center to bottom dead center, in particular shortly after top dead center or shortly before top dead center. Through its preferably targeted ignition, it is possible to increase or boost the performance of the piston steam engine.

[0017] Here, "shortly after the top dead center" is defined as an angle range of 0° to 40° (0° to 40° after the top

[0018] dead center) and under "shortly before the top dead center" an angle range of 320° to 360° (40° to 0° before the top

[0019] dead center).

[0020] In the context of the present invention, the term "exhaust steam" refers to the steam or water vapor that remains in the working chamber after the working cycle of the steam engine, i.e. after the movement of the piston from top dead center to bottom dead center (0° to 180°) forced by the introduced fresh steam, and is usually discharged from the working chamber through exhaust steam outlet openings (here the first exhaust steam outlet openings described later, which are opened and closed by the movement of the piston) or is expelled by the upward movement of the piston from bottom dead center to top dead center, in particular by opening second exhaust steam outlet openings that are opened or closed by a valve. The "exhaust steam" remaining in the working chamber after the exhaust steam outlet openings (here the first and / or second exhaust steam outlet openings described later) is referred to as "residual steam" in the context of the present invention.

[0021] Within the scope of the present invention, however, the term "residual steam" may also include "live steam" supplied during the upward movement from bottom dead center to top dead center. However, it is generally expressly stated that this is a combination of residual steam and supplied live steam.According to a further aspect of the present disclosure, the hydrogen supply device is designed as an injection or blowing device, in particular at least as an injector, which is configured to: inject or blow preferably pure hydrogen, optionally with air, or a hydrogen-oxygen mixture (oxyhydrogen gas) into the working chamber of the piston steam engine, and / or to inject or blow hydrogen or a hydrogen-oxygen mixture (oxyhydrogen gas) into the steam chamber to provide the live steam, and / or to inject or blow hydrogen, optionally with air, or a hydrogen-oxygen mixture into the working fluid before the steam chamber.

[0022] Furthermore, it is preferred that the injection or blowing device is designed such that the hydrogen in liquid form or gaseous form and / or the hydrogen-oxygen mixture in gaseous form is injected or blown into the working fluid and / or the residual steam, wherein the hydrogen-oxygen mixture is injected and / or blown into the working fluid and / or the residual steam preferably at pressures of 1 bar to 500 bar, more preferably at pressures of 1 bar to 300 bar.

[0023] According to another aspect of the present disclosure, the hydrogen boost device further comprises: an oxygen injection device configured to:

[0024] - into the working chamber of the piston steam engine, and / or

[0025] - to inject oxygen into the steam chamber to provide the fresh steam in order to adjust the ignition timing of the

[0026] Hydrogen or a hydrogen-oxygen mixture. The injection or blowing of oxygen into the working chamber and / or the vapor space, but in particular into the working chamber, can take place at different times than the injection of the hydrogen and / or the hydrogen-oxygen mixture. The injection or blowing of oxygen preferably takes place after the injection of the hydrogen and / or the hydrogen-oxygen mixture, in particular shortly before top dead center, in order to control the time of ignition of the mixture through the targeted injection of oxygen. In other words, the ignitability of the hydrogen-oxygen mixture (oxyhydrogen gas) can be controlled with the oxygen injection.

[0027] Furthermore, it is preferred that the supply of hydrogen, optionally with air, or of the hydrogen-oxygen mixture and / or the injection / blowing in of the oxygen is / are controlled or regulated in such a way that at a predetermined time, in particular shortly before top dead center, a self-ignitable or a non-self-ignitable hydrogen-oxygen mixture is present.

[0028] Furthermore, it is advantageous if the supply of hydrogen, optionally with air, or of the hydrogen-oxygen mixture, in particular the injection / injection thereof and / or the injection / injection of oxygen, takes place shortly after bottom dead center (BDC), between bottom dead center (BDC) and top dead center (TDC) or shortly before top dead center (TDC), whereby the injection / injection can preferably also take place at several points in time. In this case, the injection / injection shortly after bottom dead center is referred to as low-pressure injection, since the hydrogen (+ air), the hydrogen-oxygen mixture and / or the oxygen or the air are injected or injected at a pressure of 1 to 10 bar, in the case of air preferably at a pressure of 1 to 2 bar (air from the charger). The inlets are preferably arranged just above the first exhaust steam outlet openings.For example, injecting oxygen in the low-pressure range has the advantage of eliminating the risk of oxidation, since the temperature in the working chamber is typically below 100°C. However, this poses the problem of JA blow-by loss during compression.

[0029] If, on the other hand, the hydrogen (+air), the hydrogen-oxygen mixture and / or the oxygen or the air is injected or blown into the working chamber between bottom dead center (BDC) and top dead center (TDC), in particular in a middle region thereof, this is referred to as medium-pressure injection, with the hydrogen (+air) or the hydrogen-oxygen mixture preferably being injected or blown in at a pressure of 5 to 40 bar and / or the oxygen / air at a pressure of 2 to 10 bar. In this case, the inlets are preferably arranged between the first exhaust steam outlet openings and top dead center (TDC), in particular centrally therebetween.

[0030] Furthermore, it is referred to as high-pressure injection when the hydrogen (+air), the hydrogen-oxygen mixture and / or the oxygen or the air are injected or blown in the region of top dead center, in particular shortly before it. The hydrogen (+air) or the hydrogen-oxygen mixture is preferably injected or blown in at a pressure of 200 to 350 bar and / or the oxygen or the air is injected or blown in at a pressure of 200 to 300 bar. The inlets are preferably arranged just below top dead center (TDC). High-pressure injection has the advantage that no H2 blow-by loss occurs during compression, since the hydrogen is only injected after the main compression.According to a further aspect of the present disclosure, the hydrogen boost device further comprises a microwave device which is designed such that the microwaves which can be generated thereby can be coupled into the working chamber of the piston steam engine, in particular into an upper region (upper quarter) of the working chamber, by means of a device for coupling microwaves, whereby the hydrogen-oxygen mixture is ignited or at least the ignition temperature of the hydrogen-oxygen mixture can be reduced.

[0031] Furthermore, it is advantageous if the hydrogen boost device has a solid-state oscillator which is designed to operate the microwave device in a frequency range of 2.45 GHz to 80 GHz, preferably 25 GHz to 50 GHz, wherein the frequency is preferably precisely adjustable in a range of one Hertz.

[0032] Furthermore, it is preferred that the injection device has a plurality of injection openings which are arranged in an annular region which runs in the circumferential direction of the working chamber wall, in particular perpendicular to the central axis, wherein the injection openings are slit-shaped or circular or elliptical and preferably have a diameter or a width of less than 2 mm.

[0033] It is further advantageous if the injection openings of the injection device for injecting / blowing in hydrogen, optionally with air, and / or hydrogen-oxygen mixture and / or oxygen are arranged in the region of or above a plurality of first exhaust steam outlet openings and / or are arranged just below top dead center (TDC), wherein the exhaust steam outlet openings serve to expel the exhaust steam after the power stroke. Furthermore, it is preferred that the piston steam engine has an ignition system which is designed to ignite the introduced hydrogen-oxygen mixture, wherein the ignition system is preferably designed as at least one, preferably several, spark plugs and / or hydrogen spark plug(s), the electrode of which preferably opens directly into the working chamber.

[0034] Conventional spark plugs are not suitable for operation with pure hydrogen. Hydrogen-air mixtures are flammable over a very wide range of mixing ratios (approx. 4 to 76% by volume in air). The auto-ignition temperature of 585 °C is higher than that of a conventional gasoline-air mixture, where it is around 300 °C. Accordingly, it is advantageous to use hydrogen spark plugs in which all edges, corners, and points facing the center electrode are rounded to prevent these parts from overheating and glow ignition. In addition, the surface area to volume ratio of the center electrode is smaller than that of conventional spark plugs in order to dissipate the heat input quickly.However, due to the inert gas-like properties of steam, the high temperature peaks familiar from conventional hydrogen engines do not occur in the piston steam engine according to the invention, so that even conventional spark plugs can be used. The temperature depends on the steam content; the higher the steam content, the lower the temperature.

[0035] Furthermore, it is preferred that the piston steam engine is equipped with a thermolysis device for generating hydrogen, wherein the thermolysis device has at least one cavity which is arranged in the piston steam engine, in particular above the working space, in such a way that a predetermined proportion of the residual steam expelled after the working stroke can be collected therein and compressed to such an extent that the temperature of the compressed residual steam can be increased to 1100°C to 1500°C, in particular 1200°C to 1400°C, whereby a part of the residual steam can be decomposed into hydrogen by thermolysis.

[0036] According to a further aspect of the present disclosure, the volume of the at least one cavity is selected such that the compression ratio of the residual steam compressed in the cavity can be adjusted to a value in the range of 1:30 to 1:50, wherein preferably the amount of residual steam compressed in the cavity can be adjusted in a range of 1% to 20%, preferably 5% to 10%, of the total residual steam (plus optionally fresh steam).

[0037] Furthermore, it is preferred that fresh steam is added to the residual steam; this can be injected into the working chamber shortly before the TDC or directly into the at least one cavity.

[0038] Furthermore, it is preferred that approximately 70% to 90% of the compression volume is provided by the at least one cavity. In other words, at the time when the compression of the residual steam (optionally with live steam) is 100% complete, i.e., the piston is at top dead center (TDC), 70% to 90% of the remaining space (working chamber + cavity) is provided by the at least one cavity.

[0039] The thermolysis device preferably has a plurality of cavities. Five cavities are more preferably used. The cavities are preferably provided in a chamber plate that defines the upper boundary of the working chamber, with the cavities preferably being evenly distributed in the circumferential direction of the working chamber wall.

[0040] Furthermore, it is advantageous if the at least one or the plurality of cavities has / have a shape such that the surface area of ​​the cavity is minimal in relation to the volume of the cavity (A / V ratio), wherein preferably a surface area to volume ratio (A / V ratio) is in the range from 4.8 to 5.7, more preferably 4.83 to 5.2.

[0041] Furthermore, it is preferred that the at least one or the plurality of cavities are at least partially curved, more preferably spherical.

[0042] Furthermore, it is advantageous if a catalyst is provided in the at least one cavity to support the thermolysis, in particular to reduce the necessary starting temperature for the thermolysis. The catalyst preferably consists of nickel, platinum, or a platinum-iridium alloy. This enables so-called "catalytically induced thermolysis."

[0043] According to another aspect of the present disclosure, the catalyst is in the form of:

[0044] - a wire coil made of a platinum-iridium alloy provided within the cavity, and / or

[0045] - a cavity with a warped structure, wherein the surface of the cavity is coated with a platinum-iridium alloy.

[0046] Furthermore, it is preferred if the piston steam engine comprises: a plurality of first exhaust steam outlet openings which are provided distributed in the circumferential direction of the working chamber wall, and a plurality of second exhaust steam outlet openings which are provided above the first exhaust steam outlet openings, preferably distributed in the circumferential direction, in the working chamber wall.

[0047] Furthermore, it is advantageous if the first exhaust steam outlet openings are opened and closed by the up and down movement of the piston, and / or the second exhaust steam outlet openings are opened and closed by a valve, in particular a mechanically, electrically, electronically, pneumatically or hydraulically operated valve or combinations thereof.

[0048] According to a further embodiment of the present disclosure, the second exhaust steam outlet openings are arranged in a first annular region which runs in the circumferential direction of the working chamber wall, in particular perpendicular to the central axis, and preferably has a width (Bi) of 80 to 120 mm, preferably 50 to 80 mm, more preferably 20 to 40 mm, viewed in the direction of the central axis, wherein the second exhaust steam outlet openings preferably have a diameter of 10 to 20 mm. As already mentioned above, the second exhaust steam outlet openings serve to expel the residual steam remaining in the working chamber after the first exhaust steam outlet openings.

[0049] Furthermore, it is preferred if the first annular region of the second exhaust steam outlet openings, in particular an imaginary center line of the region which runs perpendicular to the central axis, is arranged at a distance from the top dead center in the direction of the bottom dead center by 5% to 25%, preferably 10% to 20%, of the piston stroke.

[0050] Furthermore, it is advantageous if the piston steam engine is controlled such that the second exhaust steam outlet openings are opened, preferably by means of the valve, up to a range of 20° to 10°, in particular 15° to 10°, before the top dead center of the piston stroke, wherein the second exhaust steam outlet openings are preferably opened shortly before the bottom dead center BDC, in particular in a range of 140° to 180° (40° to 0° before BDC). Furthermore, it is preferred that the piston steam engine has a superheater which is arranged between the inlet valve and the working chamber and is designed to superheat the live steam flowing in through the inlet valve towards the working chamber.

[0051] Furthermore, it is preferred that the piston steam engine has a first water injection device, comprising an injection valve and at least one water injection opening, preferably a plurality of water injection openings, which is / are provided at the same height or above the first exhaust steam outlet openings, preferably distributed in the circumferential direction, in the working chamber wall, the water being preferably injected through a multi-hole nozzle.

[0052] It is advantageous if the first

[0053] Water injection device is designed in such a way that at the time of ignition (comprising shortly before and also shortly after ignition) of the explosive mixture, it can inject water, preferably under a pressure of 100 bar to 5000 bar, into the working chamber (15) in (finely) atomized form.

[0054] According to a further aspect of the present disclosure, the piston steam engine has a second or further water injection device, comprising an injection valve and at least one water injection opening, preferably a plurality of water injection openings, wherein the injection opening(s) is / are arranged such that it opens directly or indirectly into the at least one cavity. Alternatively, only the second or further water injection device can be provided, since the functions of the two water injection devices are fundamentally different and not linked to one another. As with the first water injection device, the water is preferably injected in a (finely) atomized form under a pressure of 100 bar to 5000 bar.In this way, it is possible to prevent a recombination of the fission products hydrogen and oxygen directly in the area in which the thermolysis of the water vapor (residual vapor + optionally fresh vapor) into hydrogen and oxygen takes place at temperatures of 1100 ° C to 1500 ° C, preferably 1200 ° to 1400 ° C, by a rapid cooling (in the microsecond range) of the temperature of the mixture within the at least one cavity.

[0055] Furthermore, the piston steam engine can have a further microwave device that is arranged or configured to couple generated microwaves into the at least one cavity and thereby support thermolysis, in particular the splitting of water into hydrogen and oxygen. The frequency of the generated microwaves is preferably in a range from 2.45 GHz to 80 GHz, more preferably from 25 GHz to 50 GHz. The microwaves, in particular a microwave beam, are preferably coupled in by means of a corresponding device.

[0056] If the piston steam engine is equipped with the thermolysis device according to the invention, the (second) microwave device and the second water injection device for preventing / suppressing recombination, it is important that these three are optimally coordinated with one another. If the temperature of the live steam drops or other factors mean that the temperature required for the (catalytic) thermolysis is not optimally reached, the microwave coupling can be amplified or started in order to still achieve sufficient thermolysis. Furthermore, it is necessary to optimally adapt the injection time of the water from the second water injection device to the compression and thus to the time of the (catalytic) thermolysis in order to achieve an optimal hydrogen production rate. This can preferably be done by means of a characteristic map control.Furthermore, the timing of the water injection is preferably adapted to the microwave coupling (power) by means of a map control.

[0057] Furthermore, the piston steam engine can have a solid-state oscillator which is arranged to operate the microwave device in the frequency range from 2.45 GHz to 80 GHz, wherein the frequency is preferably precisely adjustable in the range of one Hertz.

[0058] According to a further aspect of the present disclosure, the piston steam engine may comprise a hydrogen separation device configured to separate the hydrogen obtained from the oxygen also obtained, wherein the hydrogen separation device is preferably designed as a molecular sieve or another separation device.

[0059] Furthermore, it is advantageous if the piston steam engine has a radial turbine which is connected downstream of the piston steam engine and is driven by the exhaust steam of the piston steam engine, wherein the pressure of the exhaust steam released from the piston steam engine is preferably reduced from 0.4 bar to 1.0 bar when flowing through the radial turbine to a pressure of 0.04 bar to 0.1 bar.

[0060] Furthermore, it is preferred that the radial turbine is designed to drive a generator to generate electrical energy, wherein the exhaust steam of the piston steam engine expanded by the radial turbine is preferably fed to a downstream condenser which is designed to condense the exhaust steam.

[0061] In this case, it is particularly preferred that the piston steam engine has a spray cooler which is designed to inject water, in particular finely atomized water, into the expanded exhaust steam of the radial turbine in order to reduce the temperature of the exhaust steam and thus the pressure of the exhaust steam.

[0062] It is further preferred if the piston steam engine is provided with a crosshead which couples a piston rod connected to the piston and oscillating in translation to a connecting rod which oscillates in translation and rotation (and at the same time also swings out), wherein the crosshead is preferably mounted in translation via its own sliding bearing, in particular a sliding shoe.

[0063] Furthermore, the present disclosure relates to a combined heat and power plant, comprising: a steam generator and a piston steam engine according to one of the aspects described above, wherein the piston steam engine is coupled to a generator for generating electrical power.

[0064] Furthermore, the present disclosure relates to a computer-implemented method for controlling and / or regulating a piston steam engine according to one of the aspects described above, the method comprising:

[0065] Detection of at least one exhaust steam parameter of an exhaust steam emitted by the piston steam engine, wherein the at least one exhaust steam parameter is selected from the group comprising: exhaust steam temperature, exhaust steam pressure (vacuum) and humidity of the exhaust steam,

[0066] Determining or determining an operating mode of the piston steam engine selected from the group comprising: balanced operation, increased power generation operation, maximum power generation operation and minimized power generation operation,

[0067] Determining an injection or blow-in profile of hydrogen and / or a hydrogen-oxygen mixture into the working fluid and / or the residual steam of the piston steam engine as a function of the detected at least one exhaust steam parameter and the determined or determined operating mode, and / or Determining an opening profile of a plurality of second exhaust steam outlet openings, which are provided above first exhaust steam outlet openings, preferably distributed in the circumferential direction, in the working chamber wall, as a function of the detected at least one exhaust steam parameter and the determined or determined operating mode, and / or

[0068] Determining an injection profile of at least one water injection opening, which is preferably provided at the same height or above the first exhaust steam outlet openings in the working chamber wall, depending on the detected at least one exhaust steam parameter and the determined or specified operating mode, and / or

[0069] Controlling a thermolysis device, in particular its hydrogen production rate, as a function of the detected at least one evaporation parameter and the determined or specified operating mode.

[0070] It is further preferred that the injection or blowing profile of hydrogen and / or a hydrogen-oxygen mixture comprises:

[0071] Time of at least one injection or blowing process,

[0072] Duration of the injection or blowing process, and

[0073] Amount of injected or blown-in hydrogen and / or hydrogen-oxygen mixture, wherein the at least one injection or blowing-in process takes place, preferably shortly before top dead center (TDC), preferably in an angular range of 320° to 360° (40° to 0° before TDC) and / or shortly after top dead center (TDC), preferably in an angular range of 0° to 40° (0° to 40° after TDC).

[0074] Furthermore, it is preferred that at least one opening parameter of the opening profile of the second exhaust steam outlet openings is determined or identified as a function of the detected at least one steam parameter, selected from the group comprising: opening angle (e.g. in a range of 140° to 180° (40° to 0° before bottom dead center)),

[0075] Closing angle (e.g. in a range from 40° to 10° before top dead center), injection time (e.g. 30° before bottom dead center to 30° before top dead center), opening and closing speed and degree of opening and closing, and / or at least one injection parameter of the injection profile of the water injection openings is ascertained or determined as a function of the detected at least one evaporation parameter, selected from the group comprising: opening angle (e.g. in a range from 180° to 240° (0° to 60° after bottom dead center)), closing angle (e.g. in a range from 200° to 300° (20° to 120°) after bottom dead center), opening duration or injection duration and quantity of water to be injected.

[0076] Furthermore, it is advantageous if the computer-implemented method further comprises:

[0077] Control of the thermolysis device, in particular its hydrogen generation rate, depending on the determined operating mode, wherein: in the case of increased power generation operation or maximum power generation operation, the thermolysis device is deactivated, and / or in the case of balanced operation or minimized power generation operation, the thermolysis device is activated, wherein in the case of minimized power generation operation, the hydrogen generation rate of the thermolysis device is preferably greater than in balanced operation.

[0078] Furthermore, it is preferred if, in the case of minimized power generation operation and / or balanced operation, the piston steam engine is operated with increased compression of the residual steam, preferably in the range of 1:30 to 1:50, thereby increasing the hydrogen generation rate while simultaneously reducing the output power of the piston steam engine. It is also advantageous if, in balanced operation, the amount of residual steam compressed in the cavity is lower than in minimized power generation operation.

[0079] Furthermore, it is advantageous if the computer-implemented method further comprises:

[0080] Activating a radial turbine connected downstream of the piston steam engine as a function of the detected at least one exhaust steam parameter, in particular the detected exhaust steam pressure, wherein the downstream radial turbine is preferably activated above a pressure of 1.0 bar, preferably above a pressure of 0.4 bar.

[0081] Furthermore, it is preferred if the computer-implemented method comprises:

[0082] Detection of at least one operating parameter of the piston steam engine selected from the group comprising: fresh steam temperature, fresh steam pressure, fresh steam humidity, superheater temperature, heat exchange fluid temperature, flow rate of the heat exchange fluid, pressure of the heat exchange fluid, speed of the compressor stage, speed of the centrifugal pump and oil temperature of the piston steam engine, and

[0083] Determining a target value of the at least one detected operating parameter as a function of the detected at least one exhaust steam parameter and / or at least one further detected operating parameter. Furthermore, the present disclosure relates to a controller for controlling and / or regulating a steam engine, in particular for generating electrical current, comprising a control unit and means for executing the steps of the computer-implemented method described above.

[0084] The present disclosure also relates to a computer program, in particular application software (app), comprising instructions which, when executed by a computer, cause the computer to execute the above-described computer-implemented method for controlling and / or regulating a piston steam engine. Furthermore, the present disclosure relates to a computer-readable storage medium comprising instructions which, when executed by a computer, cause the computer to execute the above-described computer-implemented method for controlling and / or regulating a piston steam engine.

[0085] Short description of the characters

[0086] Fig. 1 shows a schematic diagram of a combined heat and power plant,

[0087] Fig. 2 shows a schematic sectional view of a steam engine according to an embodiment of the present invention, wherein the piston is at bottom dead center,

[0088] Fig. 3 shows an enlarged partial view of the schematic sectional view of Fig. 2 to illustrate the arrangement of the thermolysis device according to the invention and the superheater,

[0089] Fig. 4 shows a schematic diagram of a combined heat and power plant of another embodiment of the present invention,

[0090] Fig. 5 shows an enlarged partial view of the schematic sectional view of Fig. 2 in order to further clarify the arrangement of the second exhaust steam outlet openings according to the invention and the thermolysis device according to the invention,

[0091] Fig. 6 shows an enlarged partial view of the schematic sectional view of Fig. 2 to illustrate the arrangement of the hydrogen injection device(s) and oxygen injection devices according to the invention, and

[0092] Fig. 7 shows a flow diagram of a computer-implemented method for controlling and / or regulating a piston steam engine according to the invention. Detailed Description of the Preferred Embodiments

[0093] Preferred embodiments of the present invention are described in detail below with reference to the accompanying figures. Further modifications of specific features mentioned in this context can each be combined individually to form further embodiments.

[0094] In the various figures, identical or corresponding elements are designated by the same or similar reference symbols.

[0095] Fig. 1 shows a schematic diagram of a combined heat and power (CHP) plant. The CHP plant 200 shown consists of a steam generator 110, which is connected via a valve 180 to an inlet of a piston steam engine 1, which drives a generator 130 to generate electricity. For the fine sealing of the piston steam engine 1, it is necessary to supply it with oil, which, however, mixes with the expanded steam (exhaust steam) during operation of the piston steam engine 1 and is released with it. For this reason, the expanded steam released by the piston steam engine 1 contains a small amount of oil.

[0096] The piston steam engine 1 is followed by a condenser 150 for condensing the expanded steam, which has a pressure of approximately 0.15 bar and a temperature of approximately 55 ° C when it leaves the piston steam engine 120.

[0097] The condensed steam is fed to or sucked into a condensate extraction pump (or circulation pump) 170, particularly a piston pump, via a water column 190, which increases the pressure of the condensed steam to approximately 0.25 bar. The oil is separated in the steam phase by a separator, and the separated oil is processed by a centrifuge.

[0098] As can also be seen from Fig. 1, the separated or separated oil is fed back to a crankshaft chamber of the piston steam engine or injected into the piston steam engine for fine sealing and the purified water is fed to a feed water tank 160, which makes the treated or purified water available to the steam generator 110 again for steam generation, thus closing the circuit.

[0099] Figure 2 shows a schematic sectional view of a piston steam engine 1 according to an embodiment of the present invention. The piston steam engine 1 shown has a cylinder 10 which has an upper end 11 and a lower end 12. At the lower end 12, the cylinder 10 is connected to a crankcase 20. A plurality of outlet openings 13 (first exhaust steam outlet openings) are provided in the circumferential direction in the cylinder wall / working chamber wall 14 of the cylinder 10. The outlet openings 13 connect a cylinder chamber / working chamber 15 to an annular chamber 16 in order to discharge or discharge used steam (exhaust steam) from the working chamber 15. The exhaust ports 13 are arranged near a bottom dead center UT of a piston 30, which is located at the bottom dead center UT in the view shown.

[0100] The piston 30 is translationally movable along a central axis CA of the cylinder 10 between the bottom dead center UT and a top dead center. The piston 30 is connected via a piston connecting rod or piston control rod (not shown) to a crankshaft (not shown) which is accommodated in the crankcase 20. The piston 30 has a sealing ring 31 at its lower end 32 and a plurality of sealing rings 31 at its upper end 33. The piston steam engine 1 further comprises a cylinder head unit 40. The cylinder head unit 40 has a first housing body 41 and a second housing body 42. Furthermore, a steam chamber 76 (steam space) is provided in the first housing body 41 and communicates with the working chamber 15 via an opening.The opening (valve opening 28) can be opened and closed by means of a valve element 27 of an inlet valve 26, which has a shaft 53 guided translationally in a valve guide, whereby the inflow of live steam (hot steam which is under high pressure) into the working chamber 15 can be controlled and / or regulated, the live steam acting as the working fluid of the piston steam engine 1. Alternatively, the inlet valve 26 can also be designed as an electrical, electronic, hydraulic or pneumatic valve or combinations thereof, in particular an electro-hydraulic valve. This has the advantage that the injection elements of the valve remain cool, since they can be arranged in particular above the superheater described below.

[0101] Furthermore, the piston steam engine 1 shown has a superheater 60, which is arranged between the inlet valve 26 and the working chamber 15 and is designed such that it heats the fresh steam flowing through the inlet valve 26 toward the working chamber 15 and controlled and / or regulated by the inlet valve, thereby preferably superheating it into the supercritical high-temperature range. However, the superheater 60 shown is merely optional and serves to further optimize the efficiency of the piston steam engine.

[0102] As can further be seen from Figure 2, the superheater 60 has a tube heat exchanger which is formed from a large number of individual tubes 62 which are evenly distributed around the central axis CA of the cylinder and arranged at a distance from one another. The individual tubes are bent around a bending axis Y, which is aligned perpendicular to the central axis, with a bending angle of more than 360°, so that at least one loop is formed. In this way, the tube heat exchanger 61 forms a torus-shaped structure with the large number of tubes 62. The individual tubes 62 are formed from a thick-walled steel tube and serve to supply the live steam, which is controlled and / or regulated by the inlet valve 26, from the steam chamber 76 to the working chamber 15.As can also be seen from Figure 2, the piston steam engine 1, in particular the superheater 60, has a heat exchange chamber 63 in which the pipes 62 of the toroidal tube heat exchanger 61 are arranged. The heat exchange chamber 63 has at least one inlet and at least one outlet via which the heat exchange chamber 63 can be supplied with a heat exchange fluid. In other words, during operation of the piston steam engine 1, a heat exchange fluid continuously flows through the heat exchange chamber 63, which flows around the pipes 62 of the tube heat exchanger 61 and thereby gives off heat to the live steam flowing through the pipes 62 and thereby heats, in particular superheats, the live steam.

[0103] As Figure 2 further shows, the pipes 62 are aligned approximately vertically at the end facing the working chamber 15, as a result of which an opening 62A of the pipes 62 opens approximately vertically into the working chamber 15, as a result of which the kinetic energy of the live steam can be optimally used to drive the piston 30. The two ends of the pipes 62 are each welded into a holding element, in particular a holding plate, for fixing, with the ends of the pipes 62 facing away from the working chamber 15 tapering conically towards the valve opening 28. As already described above, the superheater 60 can also be manufactured by 3D printing, in particular selective laser melting (SLM for short), in particular using Inconel (IN718) as the material. In this way, an optimized geometry of the superheater 60, in particular of the pipes 62, can be realized.

[0104] The heat exchange fluid flowing through the heat exchange chamber 63 can be a liquid metal selected from the group comprising: lead, sodium, sodium-potassium alloys (Nak), bismuth, and lead-bismuth eutectic, a salt bath selected from the group comprising: nitrate salt, in particular potassium-sodium nitrate or potassium-sodium-calcium nitrate, sodium chlorite, potassium chloride, sodium carbonate, potassium carbonate and sodium thiosulfate and a noble gas (inert gas), in particular helium, argon or xenon, or a noble gas mixture, preferably helium with nitrogen, or flue gas.

[0105] The use of a liquid metal or a salt bath has the advantage of allowing very large amounts of heat to be transferred at low flow velocities. However, the high temperatures of the liquid metals or salts place stringent demands on the flow-carrying components. When using gases, especially noble gases such as helium, the temperature resistance requirements of the flow-carrying components can be reduced, as helium protects the flow-carrying components, particularly against aging. This even makes it possible to increase the temperature to over 1000°C if desired.

[0106] If a gas, in particular a noble gas, a noble gas mixture or flue gas, is used as the heat exchange fluid, a compressor stage 70 can be connected upstream of the superheater 60, as shown in Figure 4. This compressor stage serves to charge the gas supplied to the piston steam engine 1, in particular to increase the pressure of the gas to 1 to 30 bar, in particular 5 to 20 bar, and to increase the flow velocity of the gas. The highest possible flow velocities in the range of 10 to 20 m / s, sometimes up to 50 m / s, are advantageous here. The charging of the gas, in particular the increase in the flow velocity, is necessary in order to be able to transfer sufficient heat from the heat exchange fluid to the live steam flowing through the pipes 62.

[0107] The compressor stage can be designed as an electrically driven turbine or centrifugal pump or as a turbocharger and, if desired, can have guide vane adjustment. If thermal turbocharging is used, it can be driven by the exhaust steam from the piston steam engine and / or by the exhaust gas (flue gas) from the steam generator 110 connected upstream of the piston steam engine 1.

[0108] On the other hand, if a liquid metal or a salt bath is used as the heat exchange fluid, an agitator and / or a centrifugal pump and / or a magnetic field pump can be connected upstream and / or downstream of the superheater 60, which cause the heat exchange fluid to flow, in particular to flow it through the heat exchange chamber 63.

[0109] Furthermore, the piston steam engine 1 shown has a hydrogen boost device 340. The hydrogen boost device 341 shown has a hydrogen supply device 345 which is designed to introduce a predetermined amount of (pure) hydrogen or a hydrogen-oxygen mixture (oxyhydrogen gas) into the working fluid and / or the residual steam of the piston steam engine in such a way that during the movement of the piston from top dead center (TDC) to bottom dead center (BDC), in particular shortly after top dead center (TDC), or shortly before top dead center (TDC), an explosive or flammable mixture, in particular a hydrogen-oxygen mixture, is present, the (targeted) ignition of which can increase the performance of the piston steam engine.In the embodiment shown, the hydrogen supply device 345 is designed as an injection or blowing device 350 which is designed to inject or blow a hydrogen-oxygen mixture (oxyhydrogen gas) into the working chamber 15 of the piston steam engine 1, wherein the hydrogen-oxygen mixture can be injected or blown in at pressures of 2 bar to 500 bar.

[0110] Furthermore, the hydrogen boost device 340 shown has an oxygen injection device 370 which is designed to inject oxygen into the working chamber 15 of the piston steam engine 1 in order to control or regulate the ignition point of the hydrogen or hydrogen-oxygen mixture.

[0111] The hydrogen boost device 340 shown further comprises an ignition system 360 which is designed to ignite the introduced hydrogen-oxygen mixture, wherein the ignition system is designed as a plurality of spark plugs or hydrogen spark plugs, the electrode(s) of which preferably open directly into the working chamber.

[0112] Furthermore, the piston steam engine 1 shown has a thermolysis device 300, which serves to generate hydrogen by thermolysis at times when there is a surplus of renewable energy, e.g., on extremely sunny days, and thus the achievable energy price is rather low. For this purpose, the thermolysis device 300, as shown in Figures 2, 3, and 5, has at least one cavity 310, preferably a plurality of cavities, which are evenly distributed in the circumferential direction of the working chamber. In the illustrated embodiment, the device 300 has five cavities 310, with only two cavities visible in section. The cavities 310 are open at the bottom and thus communicate with the working chamber 15.In this way, after the power stroke, a desired (predetermined) amount of residual steam, into which live steam can also be injected shortly before TDC, can be collected in the cavities and compressed to such an extent that the temperature of the compressed residual steam is increased to 1200 ° C to 1500 ° C, whereby at least part of the residual steam is decomposed or split into hydrogen and oxygen by thermolysis. For this purpose, the residual steam, which can also contain live steam, must be compressed to values ​​in the range of 1 : 30 to 1 : 50, with approximately 1% to 20% of the available residual steam being compressed in the cavities 310, and the remaining residual steam is expelled as usual.

[0113] As can be seen from Figure 3, the five cavities 310 are provided in the chamber plate 64 which delimits the working space 15 at the top, the cavities 310 having an at least partially spherical contour. What cannot be seen from the figures is that the cavities 310 are provided with a catalyst 311 which serves to assist the thermolysis, in particular to reduce the temperature necessary until the thermolysis starts. For this purpose, platinum or a platinum-iridium alloy is generally used, which can either be introduced into the cavities 310 as a wire coil or the cavities 310 themselves, which preferably have a warp structure, are coated with platinum or a platinum-iridium alloy. Nickel can also be used as a catalyst to bring about catalytically induced thermolysis; accordingly, Inconel is also a suitable material.

[0114] As can also be seen from Fig. 5, the piston steam engine 1 according to the present embodiment has a (second) water injection device 320 which has an injection valve 321 and at least one water injection opening 322, preferably a plurality of water injection openings, wherein the injection opening 322 is arranged such that it opens directly into the at least one cavity 310. In this way, within microseconds after the compressed residual steam has been decomposed or split into hydrogen and oxygen by thermolysis, the temperature in the cavity can be reduced ultra-rapidly and the proportion of water vapor in the cavity can be increased by injecting pressurized water, whereby a recombination of hydrogen and oxygen to form water can be suppressed.The water is injected at a pressure of 100 to 5000 bar, allowing the injected droplets to have extremely small Sauter diameters, resulting in very rapid evaporation and thus rapid cooling. The higher the water injection pressure to prevent recombination, the larger the surface area of ​​the droplets (smaller Sauter diameter), and the faster the recombination is prevented.

[0115] Furthermore, the piston steam engine can be equipped with a microwave device (not shown in the figures) arranged such that the microwaves generated thereby penetrate the at least one cavity 310 and thereby support the thermolysis, in particular the splitting of water into hydrogen, wherein the frequency of the microwaves generated is in a range from 2.45 GHz to 80 GHz, preferably 25 GHz to 50 GHz. In this case, a correspondingly designed device for coupling the microwaves is preferably used.

[0116] In this case, a solid-state oscillator (not shown in the figures) can also be provided, which is designed to operate the microwave device in the frequency range from 2.45 GHz to 80 GHz, wherein the frequency can preferably be precisely adjusted in a range of one Hertz.

[0117] As can also be seen from Figure 5, the piston steam engine shown has a hydrogen separation device 330 which is designed to separate the hydrogen obtained from the oxygen which is also obtained, wherein the hydrogen separation device 330 is preferably designed as a molecular sieve.

[0118] In addition to the first exhaust steam outlet openings 13 (outlet openings), a plurality of second exhaust steam outlet openings 18 are provided above the first exhaust steam outlet openings 13, distributed in the circumferential direction in the working wall 14. The first exhaust steam outlet openings 13 are opened and closed by the up and down movement of the piston 30. The second exhaust steam outlet openings 18, on the other hand, are opened and closed by a valve (19), in particular a mechanically, electrically (magnetically), electronically, pneumatically or hydraulically operated valve or combinations thereof. In this way, it is possible to change the opening and closing times of the valve 19 depending on the engine load and / or the status data of the piston steam engine. In contrast to the first exhaust steam outlet openings 13, the second exhaust steam outlet openings 18 are optional and serve to further optimize the efficiency of the piston steam engine 1.

[0119] As can be seen from Figure 2, but in particular from Figure 5, the second exhaust steam outlet openings 18 are arranged in a first annular region which runs in the circumferential direction of the working chamber wall 14 perpendicular to the central axis CA and has a width Bi of 80 to 120 mm viewed in the direction of the central axis CA, the second exhaust steam outlet openings 18 having a diameter of 10 to 20 mm. Furthermore, the first annular region of the second exhaust steam outlet openings 18, in particular an imaginary center line of the region which runs perpendicular to the central axis CA, is arranged at a distance of 5% to 25% of the piston stroke from the top dead center TDC in the direction of the bottom dead center TDC. Additionally or alternatively, as shown in Figure 4, the piston steam engine 1 or the combined heat and power plant 200 may be equipped with a radial turbine 80 (steam turbine) which is connected downstream of the piston steam engine 1.The radial turbine 80 is driven by the exhaust steam from the piston steam engine 1, whereby the pressure of the exhaust steam released from the piston steam engine 1 is reduced from 0.4 bar to 1.0 bar as it flows through the radial turbine to a pressure of 0.04 bar to 0.1 bar. By installing the radial turbine in the exhaust steam line of the piston steam engine 1, a back pressure is created in the outlet of the piston steam engine 1, whereby the pressure of the released steam increases from approximately 0.15 bar to 0.5 bar. As can also be seen from Figure 4, the radial turbine 80 is used to drive a generator 130 to generate electrical energy, the exhaust steam from the piston steam engine 1 expanded by the radial turbine being fed to a downstream condenser 150 to condense the exhaust steam.

[0120] As Figure 4 also shows, the piston steam engine 1 or the combined heat and power plant 200 can be provided with a spray cooler 90. The spray cooler serves to inject water into the expanded exhaust steam of the radial turbine in order to further lower the temperature of the exhaust steam and thus improve the vacuum. In other words, by injecting finely atomized water into the exhaust steam of the radial turbine, the temperature of the exhaust steam is lowered and thus the pressure is further reduced (the vacuum is increased), whereby the power of the radial turbine can be increased and thus more electrical power can be generated.

[0121] The radial turbine 80 is preferably provided in combination with the spray cooler 90, whereby the increased performance of the radial turbine 80 allows as much electricity and as little heat as possible to be produced in the summer months, since the heat requirement is generally reduced.

[0122] Figures 2 and 4 further show that the piston steam engine 1 or the combined heat and power plant 200 can optionally be equipped with a (first) water injection device 100, which has an injection valve 101 and a plurality of water injection openings 102, wherein the water injection openings 102 are provided at the same height or above the first exhaust steam outlet openings 13, distributed in the circumferential direction in the working chamber wall 14. It is also conceivable to provide the injection openings in the upper region of the cylinder or the cylinder head.

[0123] Figure 6 shows an enlarged partial view of the schematic sectional view of Fig. 2 in order to clarify the arrangement of the hydrogen injection device(s) 350 according to the invention and oxygen injection devices 370. As can be seen from Fig. 6, a first injection or blowing device 350 for hydrogen or a hydrogen-oxygen mixture and an oxygen injection device 370 are arranged approximately centrally between the bottom dead center BDC and the top dead center TDC. In the embodiment shown, both are arranged slightly offset downwards. With such an arrangement of the devices, in particular their inlets or. Injection openings 351 in the working chamber wall, one speaks of a medium pressure injection, in which the hydrogen (+air) or the hydrogen-oxygen mixture at a pressure of 5 to 40 bar and the oxygen or.the air is injected or blown in at a pressure of 2 to 10 bar.

[0124] Additionally or alternatively, the injection or blowing device 350 for hydrogen or a hydrogen-oxygen mixture as well as the oxygen injection device 370 can be arranged in the region of the top dead center, i.e. just below the chamber plate 64. In this case, one speaks of a high-pressure injection, in which hydrogen (+air) or the hydrogen-oxygen mixture is injected or blown in at a pressure of 200 to 350 bar and the oxygen or the air is injected or blown in at a pressure of 200 to 300 bar. In this case, the inlets 351 can be arranged just below the second exhaust steam outlet openings, as shown.

[0125] Furthermore, it is also possible to arrange the injection or blowing device 350 for hydrogen or a hydrogen-oxygen mixture as well as the oxygen injection device 370 in the region of the bottom dead center (not shown). In this case, it is possible to arrange the inlets at the same height as the water injection openings 102 shown. With such a low arrangement of the inlets, one speaks of low-pressure injection, since the hydrogen (+air), the hydrogen-oxygen mixture or the oxygen as well as the air are injected or blown in at a pressure of 1 to 10 bar.

[0126] Figure 7 shows a flow diagram of a computer-implemented method for controlling and / or regulating a piston steam engine 1 according to the invention. The computer-implemented method shown is used to operate the piston steam engine described above in connection with Figures 1 to 6. As can be seen from Figure 7, the method comprises the following steps:

[0127] Detection S 10 of at least one exhaust steam parameter of an exhaust steam emitted by the piston steam engine 1, wherein the at least one exhaust steam parameter is selected from the group comprising: exhaust steam temperature, exhaust steam pressure (vacuum) and humidity of the exhaust steam,

[0128] Determining S20 an operating mode of the piston steam engine, selected from the group comprising: balanced operation, increased power generation operation, maximum power generation operation and minimized power generation operation,

[0129] Determining S30 an injection or blow-in profile of hydrogen and / or a hydrogen-oxygen mixture into the working fluid and / or the residual steam of the piston steam engine 1 as a function of the detected at least one exhaust steam parameter and the determined or specified operating mode, and / or

[0130] Determining S40 an opening profile of a plurality of second exhaust steam outlet openings 18, which are provided above the first exhaust steam outlet openings 13, preferably distributed in the circumferential direction, in the working chamber wall 14, depending on the detected at least one exhaust steam parameter in combination with the determined operating mode, and / or

[0131] Determining S50 an injection profile of a plurality of water injection openings 102, which are preferably provided at the same height or above the first exhaust steam outlet openings 13 in the working chamber wall 14, depending on the detected at least one exhaust steam parameter in combination with the determined operating mode, and / or

[0132] Controlling S60 the thermolysis device 300, in particular its hydrogen generation rate, as a function of the detected at least one evaporation parameter in combination with the determined operating mode.

[0133] As can be further seen from Figure 7, the computer-implemented method may optionally comprise the following additional steps:

[0134] Determining or determining S70 at least one opening parameter of the opening profile of the second exhaust steam outlet openings 18 as a function of the detected at least one steam parameter, selected from the group comprising: opening angle (e.g. in a range from 140° to 180° (40° to 0° before BDC)), closing angle (e.g. in a range from 20° to 10° before TDC), opening and closing speed and opening and closing degree, and / or Determining or determining S80 at least one injection parameter of the injection profile of the water injection openings 102 as a function of the detected at least one exhaust steam parameter, selected from the group comprising: opening angle (e.g. in a range from 180° to 240° (0° to 60° after BDC)), closing angle (e.g. in a range from 200° to 300° (20° to 120° after BDC), opening time or injection time and amount of water to be injected.

[0135] In the computer-implemented method according to the invention, it is further advantageous that the main injection of the fresh steam (high-pressure steam) is prioritized, and all other control loops are subordinate to the control of the fresh steam, in particular its injection. From the foregoing description, those skilled in the art will recognize that various modifications and variations of the device and method of the invention can be implemented without departing from the scope of the invention.

[0136] Furthermore, the invention has been described with reference to specific embodiments, which are intended only to facilitate understanding of the invention and are not intended to be limiting. Those skilled in the art will also readily recognize that many different combinations of the elements may be used to practice the present invention. Therefore, the scope of the invention is indicated by the following claims.

[0137] List of reference symbols

[0138] 1 piston steam engine

[0139] 10 cylinders

[0140] 13 first exhaust steam outlet openings

[0141] 14 Workroom wall

[0142] 15 work space

[0143] 18 second steam outlet valve (control valve second steam outlet)

[0144] Inlet valve

[0145] valve body

[0146] Valve opening

[0147] valve seat

[0148] Pistons

[0149] Superheater

[0150] tube heat exchanger

[0151] Pipes of the tube heat exchanger A opening

[0152] Heat exchange chamber

[0153] Compression stage

[0154] Steam room

[0155] Radial turbine

[0156] Spray cooler 0 (first) water injection device 1 injection valve 2 water injection ports 0 steam generator 0 generator 0 condenser 0 thermolysis device 0 cavity(ies) for thermolysis 0 (second) water injection device 1 injection valve (of the water injection device) 2 injection port(s) (of the water injection device) 0 hydrogen separation device 0 hydrogen boost device 5 hydrogen supply device 0 injection or blowing device 1 injection ports (hydrogen boost device) 0 ignition system 0 oxygen injection device

Claims

Patent claims 1. Piston steam engine (1), which is preferably used for generating electrical power, comprising: at least one cylinder (10) which encloses a working chamber (15), a piston (30) which is movable back and forth in the working chamber (15) between a top dead center (OT) and a bottom dead center (UT) along a central axis (CA) of the cylinder (10), a steam chamber (76) for providing fresh steam, an inlet valve (26) for controlling and / or regulating a fluid flow of the provided fresh steam which functions as the working fluid of the piston steam engine, wherein the working chamber (15) is enclosed over its circumference by a working chamber wall (14) inserted into the cylinder (10) or formed by the latter, and a hydrogen boost device (340), comprising: a hydrogen supply device (345) which is designed toto introduce a predetermined amount of (pure) hydrogen or a hydrogen-oxygen mixture (oxyhydrogen gas) into the working fluid and / or the residual steam of the piston steam engine in such a way that during the movement of the piston (30) from top dead center (TDC) to bottom dead center (UT), in particular shortly after top dead center (TDC), or shortly before top dead center (TDC), an ignitable (explosive) mixture, in particular a hydrogen-oxygen mixture, is present, by the (targeted) ignition of which the working performance of the piston steam engine can preferably be increased.

2. Piston steam engine (1) according to claim 1, wherein the hydrogen supply device (345) is designed as an injection or blowing device (350), in particular at least as an injector, which is designed to: to inject or blow (pure) hydrogen or a hydrogen-oxygen mixture (oxyhydrogen gas) into the working chamber (15) of the piston steam engine (1), and / or to inject or blow hydrogen or a hydrogen-oxygen mixture (oxyhydrogen gas) into the steam chamber (76) to provide the live steam, and / or to inject or blow hydrogen or a hydrogen-oxygen mixture into the working fluid before the steam chamber (76).

3. Piston steam engine (1) according to claim (2), wherein the injection or blowing device (350) is designed such that the hydrogen in liquid form or gaseous form and / or the hydrogen-oxygen mixture in gaseous form is injected or blown into the working fluid and / or the residual steam, wherein the hydrogen-oxygen mixture is injected and / or blown into the working fluid and / or the residual steam preferably at pressures of 1 bar to 500 bar, more preferably pressures of 1 bar to 100 bar.

4. Piston steam engine (1) according to one of the preceding claims, wherein the hydrogen boost device (340) further comprises: an oxygen injection device (370) which is designed to: inject oxygen into the working chamber (15) of the piston steam engine (1) and / or into the steam chamber (76) for providing the hydrogen steam, in order to control and / or regulate the ignition point of the hydrogen or hydrogen-oxygen mixture.

5. Piston steam engine (1) according to one of the preceding Claims, wherein the supply of the hydrogen or the hydrogen-oxygen mixture and / or the Injection / injection of oxygen is controlled or regulated in such a way that at a predetermined time, in particular shortly before top dead center (TDC), a self-ignitable or non-self-ignitable Hydrogen-oxygen mixture is present.

6. Piston steam engine (1) according to one of the preceding claims, wherein the supply of the hydrogen or the hydrogen-oxygen mixture, in particular the injection / injection thereof and / or the injection / injection of the oxygen takes place shortly after the bottom dead center (BDC) (low-pressure injection), between the bottom dead center (BDC) and the top dead center (TDC) (medium-pressure injection) or shortly before the top dead center (TDC) (high-pressure injection), wherein the injection / injection can preferably also take place at several points in time.

7. Piston steam engine (1) according to one of the preceding claims, wherein the hydrogen boost device (340) further comprises a microwave device which is designed such that the microwaves which can be generated thereby can be coupled into the working chamber (15) of the piston steam engine, in particular into an upper region (upper) of the working chamber, by means of a device for coupling in microwaves (whereby the hydrogen-oxygen mixture is ignited or the ignition temperature of the hydrogen-oxygen mixture can be reduced).

8. Piston steam engine (1) according to claim 7, wherein the hydrogen boost device (340) further comprises: a solid-state oscillator configured to operate the microwave device in a frequency range of 2.45 GHz to 80 GHz, preferably 25 GHz to 50 GHz, wherein the frequency is preferably precisely adjustable in a range of one hertz.

9. Piston steam engine (1) according to one of the preceding claims 2 to 8, wherein the injection device has a plurality of injection openings which are arranged in an annular region which runs in the circumferential direction of the working chamber wall (14), in particular perpendicular to the central axis (Ca), wherein the injection openings are slit-shaped or circular or elliptical and preferably have a diameter of less than 2 mm.

10. Piston steam engine (1) according to claim 9, wherein the injection openings of the injection device for injecting / blowing in hydrogen and / or hydrogen-oxygen mixture and / or oxygen are arranged in the region of or above a plurality of first exhaust steam outlet openings (13) and / or are arranged just below the top dead center (TDC).

11. Piston steam engine (1) according to one of the preceding claims, further comprising an ignition system (360) which is designed to ignite the introduced hydrogen-oxygen mixture, wherein the ignition system is preferably designed as at least one, preferably several, spark plugs or hydrogen spark plugs, the electrode of which preferably opens directly into the working chamber (15).

12. Piston steam engine (1) according to one of the preceding claims, further comprising: a thermolysis device (300) for generating hydrogen, wherein the thermolysis device (300) has at least one cavity (310) which is arranged in the piston steam engine (1), in particular above the working space (15), such that a predetermined portion of the residual steam expelled after the working stroke can be collected therein and compressed to such an extent that the temperature of the compressed residual steam reaches 1100°C to 1500°C, in particular 1200°C to 1400°C, whereby part of the residual steam can be decomposed into hydrogen by thermolysis.

13. Piston steam engine (1) according to claim 12, wherein the thermolysis device (300) has a plurality of cavities (310), in particular 5 cavities (310), which are preferably provided in a chamber plate (64) delimiting the working space (15) at the top, which are preferably provided uniformly distributed in the circumferential direction of the working space wall (14).

14. Piston steam engine (1) according to one of the preceding claims 10 or 11, wherein a catalyst (311) is provided in the at least one cavity (310) to support the thermolysis, in particular to reduce the necessary starting temperature of the thermolysis, wherein the catalyst preferably consists of nickel, platinum or a platinum-iridium alloy.

15. Piston steam engine (1) according to one of the preceding claims, further comprising: a plurality of first exhaust steam outlet openings (13) which are provided distributed in the circumferential direction of the working chamber wall (14), and / or a plurality of second exhaust steam outlet openings (18) which are provided above the first exhaust steam outlet openings (13), preferably distributed in the circumferential direction, in the working chamber wall (14).

16. Piston steam engine (1) according to claim 15, wherein the first exhaust steam outlet openings (13) are opened and closed by the up and down movement of the piston (30), and / or the second exhaust steam outlet openings (18) are opened and closed by a valve (19), in particular a mechanically, electrically, electronically, pneumatically or hydraulically operated valve or combinations thereof.

17. Piston steam engine (1) according to one of the preceding claims, further comprising a superheater (60) which is arranged between the inlet valve (26) and the working chamber (15) and is designed to superheat the fresh steam flowing in through the inlet valve (26) in the direction of the working chamber (15).

18. Piston steam engine (1) according to one of the preceding claims, further comprising: a first water injection device (100) having an injection valve (101) and at least one water injection opening, preferably a plurality of water injection openings (102), which is / are provided at the same height or above the first exhaust steam outlet openings (13), preferably distributed in the circumferential direction, in the working chamber wall (14), the water is preferably injected through a multi-hole nozzle.

19. Piston steam engine (1) according to claim 18, wherein the first water injection device (100) is designed such that at the time of ignition (comprising shortly before and also shortly after ignition) of the explosive mixture (fine) it can inject water, preferably under a pressure of 100 bar to 5000 bar, into the working chamber (15) in a (finely) atomized form.

20. Piston steam engine (1) according to one of the preceding claims, further comprising: a second water injection device (320) having an injection valve (321) and at least one water injection opening (322), preferably a plurality of water injection openings, wherein the injection opening(s) is arranged such that it opens directly or indirectly into the at least one cavity (310), wherein the water is preferably injected under a pressure of 100 bar to 5000 bar.

21. Piston steam engine (1) according to one of the preceding claims, further comprising: a further microwave device which is configured to couple producible microwaves into the at least one cavity (310) and thereby support the thermolysis, in particular the splitting of water into hydrogen and oxygen, wherein the frequency of the producible microwaves is in a range from 2.45 GHz to 80 GHz, preferably 25 GHz to 50 GHz, and preferably a device for coupling the microwaves is provided.

22. Combined heat and power plant (200), comprising: a steam generator (110), and a piston steam engine (1) according to one of the preceding claims 1 to 21, wherein the piston steam engine (1) is coupled to a generator (130) for generating electrical power.

23. Computer-implemented method for controlling and / or regulating a piston steam engine (1) according to one of claims 1 to 19, comprising: Detecting at least one exhaust steam parameter of an exhaust steam emitted by the piston steam engine (1), wherein the at least one exhaust steam parameter is selected from the group comprising: exhaust steam temperature, exhaust steam pressure (vacuum) and humidity of the exhaust steam, Determining or determining an operating mode of the piston steam engine (1) selected from the group comprising: balanced operation, increased power generation operation, maximum power generation operation and minimized power generation operation, Determining an injection or blow-in profile of hydrogen and / or a hydrogen-oxygen mixture into the working fluid and / or the exhaust steam of the piston steam engine (1) as a function of the detected at least one exhaust steam parameter and the determined or specified operating mode, and / or Determining an opening profile of a plurality of second exhaust steam outlet openings (18) which are provided above first exhaust steam outlet openings (13), preferably distributed in the circumferential direction, in the working chamber wall (14), depending on the detected at least one exhaust steam parameter and the determined or specified operating mode, and / or Determining an injection profile of at least one water injection opening (102), which is preferably provided at the same height or above the first exhaust steam outlet openings (13) in the working chamber wall (14), depending on the detected at least one exhaust steam parameter and the determined or specified operating mode, and / or Controlling a thermolysis device (300), in particular its hydrogen generation rate, as a function of the detected at least one evaporation parameter and the determined or specified operating mode.

24. A computer-implemented method according to claim 23, wherein the injection or blowing profile of hydrogen and / or a hydrogen-oxygen mixture comprises: Time of at least one injection or blowing process, duration of the injection or blowing process, and quantity of injected or blown-in hydrogen and / or hydrogen-oxygen mixture, wherein the at least one injection or blowing process preferably takes place shortly before top dead center (TDC), preferably in an angular range of 320° to 360° (40° to 0° before TDC) and / or shortly after top dead center (TDC), preferably in an angular range of 0° to 40° (0° to 40° after TDC).

25. Computer-implemented method according to claim 23 or 24, wherein at least one opening parameter of the opening profile of the second exhaust steam outlet openings (18) is determined as a function of the detected at least one steam parameter is determined or ascertained, selected from the group comprising: opening angle (e.g. in a range from 140° to 180° (40° to 0° before BDC)), closing angle (e.g. in a range from 20° to 10° before TDC), opening and closing speed and opening and closing degree, and / or at least one injection parameter of the injection profile of the water injection openings (102) is determined or ascertained as a function of the detected at least one evaporation parameter, selected from the group comprising: Opening angle (e.g. in a range of 180° to 240° (0° to 60° after BDC)), closing angle (e.g. in a range of 200° to 300° (20° to 120° after BDC), opening duration or injection duration and quantity of water to be injected.

26. Control system for controlling and / or regulating a steam engine (1), in particular for generating electrical current, comprising a control unit and means for carrying out the steps of the method according to one of claims 23 to 25.

27. Computer program, in particular application software (app), comprising instructions which, when executed by a computer, cause the computer to execute the computer-implemented method for controlling and / or regulating a piston steam engine (1) according to one of the preceding claims 23 to 25.

28. Computer-readable storage medium comprising instructions which, when executed by a computer, cause the computer to execute the computer-implemented method for controlling and / or regulating a piston steam engine (1) according to one of the preceding claims 23 to 25.

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