Piston steam engine comprising an additional outlet valve, 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 present invention relates to a piston steam engine (1) that is preferably used to generate electric power, said piston steam engine comprising: at least one cylinder (10) that encloses a working chamber (15); a piston that can move back and forth in the working chamber (15) along a central axis of the cylinder (10) between a top dead centre and a bottom dead centre; a steam chamber (76) for providing fresh steam; an inlet valve (26) for controlling, in an open-loop and / or closed-loop manner, a fluid flow of the provided fresh steam which acts as the working fluid of the piston steam engine, the working chamber (15) being enclosed over its periphery by a working chamber wall (14) formed by or inserted into the cylinder (10); a plurality of first exhaust-steam outlet openings (13) which are distributed peripherally in the working chamber wall (14); and a plurality of second exhaust-steam outlet openings (18) which are provided in the working chamber wall (14), preferably distributed peripherally, above the first exhaust-steam outlet openings (13). The present invention also relates to: a combined heat and power plant comprising the steam engine (1); a computer-implemented method for controlling, in an open-loop and / or closed loop manner, a piston steam engine; and a computer program and a computer-readable storage medium.

Description

[0001] Piston steam engine with additional exhaust valve, one

[0002] Combined heat and power plant having a piston steam engine, a computer-implemented method for controlling the piston steam engine and a control system for controlling the piston steam engine

[0003] Technical area

[0004] The present disclosure relates to a piston steam engine with an additional exhaust valve, in particular to a piston steam engine that performs mechanical work using steam as its working fluid. More specifically, the present disclosure relates to a piston steam engine that is preferably used in the generation of electricity. Furthermore, the present disclosure relates to a combined heat and power plant comprising 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.

[0005] background

[0006] 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.

[0007] 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).

[0008] 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.

[0009] By using a salt bath as a heat transfer medium, reliable operation can be ensured despite the fluctuating energy content of the fuel mass of the steam generator, which uses, for example, biomass as an energy source. However, such steam generators are slow and, particularly at desired fresh steam temperatures above 500 °C, place high demands on the material (aging resistance) of the flow-carrying components of the fresh steam in the combined heat and power plant.

[0010] Accordingly, there is a need for a solution for a piston steam engine or a combined heat and power plant which operates efficiently, particularly when using biomass, in the high-temperature and high-pressure range and at the same time minimises the thermal load on the individual components.

[0011] Subject of the invention

[0012] The object of the invention is to provide a piston steam engine which is capable of further increasing the efficiency of highly developed piston steam engines, such as those developed in recent times, and thus of pushing them to their physical limits. On the one hand, the aim is to achieve maximum superheating of the working fluid (live steam) with minimal thermal stress on the overall system (piston steam engine and components of the combined heat and power plant), and on the other hand, to enable maximum flexibility of the overall system, thus enabling a quick and, in particular, efficient response to external conditions such as load changes, available live steam temperature and / or flue gas temperature.

[0013] 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 13. The stated object is further achieved by a computer-implemented method according to claim 14, a controller according to claim 18, a computer program according to claim 19 and a computer-readable storage medium according to claim 20. 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.

[0014] One of the basic ideas of the present disclosure is to provide a piston steam engine having a superheater arranged between an inlet valve of the piston steam engine and the working chamber of the piston steam engine and configured to superheat the fresh steam flowing in through the inlet valve toward the working chamber.

[0015] In this way, a piston steam engine can be provided which, on the one hand, makes it possible to operate the piston steam engine with live steam which has a lower temperature (superheating), which reduces the demands on the upstream steam generator and avoids or reduces material fatigue of the components carrying the live steam, and on the other hand, the supplied live steam can be heated directly to the required or optimized temperature on the way to the working chamber, in particular during introduction / injection into this. This also makes it possible to reduce the temperature occurring at the control valve (inlet valve) of the piston steam engine, whereby reliable and permanent closing or shutting off of the control valve can be ensured, despite the high working temperatures and pressures present in the working cycle of a piston steam engine according to the invention.

[0016] When reference is made to high temperatures in the present application, this applies in particular to the necessary steam flow, where temperatures in excess of 100°C are necessary to operate the piston steam engine efficiently. For the efficient operation of a piston steam engine, operating parameters with a fluid pressure (steam pressure) of, as already mentioned above, 30 to 800 bar, preferably 30 to 500 bar, particularly preferably 30 to 180 bar, and fluid temperatures (steam temperatures) of 300°C to 1000°C, preferably 300°C to 600°C are not unusual. With such operating parameters, high thermal stress on all components, in particular high thermal stresses, are to be expected. Furthermore, in piston steam engines, reliable sealing is more difficult to achieve due to the smaller molecular size (H2O) of the water vapor compared to the combustion gases (CO2) in the internal combustion engine.

[0017] The term "live steam" in the present disclosure refers to steam / superheated steam that is supplied, for example, from a steam generator to a piston steam engine to operate the piston steam engine. The live steam generally has pressures in the range of 30 to 180 bar and temperatures above 100 °C. Due to the proposed piston steam engine with superheater, it is possible to operate the piston steam engine even in the supercritical high-temperature range with pressures of 200 bar to 800 bar and temperatures in the range of 200 °C to 1000 °C. In other words, due to the provided superheater, it is possible to increase the live steam temperature from 100 °C to 200 °C, as provided by the steam generator, to a temperature of 300 °C to 100 °C without exposing the control valve to such high temperatures.

[0018] Accordingly, the term "superheating" in the present disclosure means that the temperature of the fresh steam, which is generally dependent on the upstream steam generator, is increased to a desired or optimized working temperature which lies in a range from 200 ° C to 1000 ° C. However, since the fresh steam is usually already provided by the steam generator at temperatures above 100 ° C, this does not refer to heating the fresh steam but to superheating, in particular superheating into the supercritical high-temperature range.

[0019] 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 can be moved 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 fresh steam provided, which acts as the working fluid of the piston steam engine, and a superheater which is arranged between the inlet valve and the working chamber and is designed to superheat the fresh steam flowing in through the inlet valve towards the working chamber.According to a further aspect of the present disclosure, the superheater comprises a tube heat exchanger which is designed such that the fresh steam supplied from the steam space flows through at least one pipe, preferably a plurality of pipes, of the tube heat exchanger and thereby absorbs heat from a heat exchange fluid flowing around the pipe, whereby the fresh steam can be superheated.

[0020] Furthermore, it is advantageous if an opening in the at least one pipeline, preferably in the plurality of pipelines, which is provided at an end of the pipeline facing the working space, opens approximately vertically into the working space. It is also conceivable to create the superheater using 3D laser printing, which allows for the realization of an optimized heat exchanger surface. For example, the pipelines or guide channels can be designed with a square, rectangular, n-sided, oval, or similar cross-section.

[0021] Furthermore, it is preferred that the tube heat exchanger has a plurality of pipes, which are preferably arranged in a toroidal shape around the central axis of the cylinder, preferably evenly distributed. It is also advantageous if the individual pipes are bent in a loop-like manner around a bending axis, which is preferably aligned approximately perpendicular to the central axis, with a bending angle of more than 360°, preferably more than 540°.

[0022] In this way, the residence time of the fresh steam flowing through the pipes of the tube heat exchanger can be extended, thus increasing the heat exchange between the heat exchange fluid and the fresh steam. The loop-shaped geometry significantly increases the wall heat transfer. Furthermore, it is advantageous if the heat exchange fluid is a:

[0023] 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, a noble gas (inert gas), in particular helium, argon or xenon, or a noble gas mixture, preferably helium with nitrogen, or flue gas.

[0024] Furthermore, it is preferred if a gas, in particular noble gas, noble gas mixture or flue gas, is used as the heat exchange fluid, a compressor stage is connected upstream of the superheater, which compressor stage is designed to charge the gas supplied to the piston steam engine, in particular to increase the pressure of the gas to 1 to 30 bar, in particular 5 to 20 bar, and / or to increase the flow velocity of the gas.

[0025] Furthermore, it is advantageous if the compressor stage is designed as an electrically driven turbine or centrifugal pump or as a turbocharger and preferably has a guide vane adjustment, wherein in the case of a turbocharger this is preferably designed such that it can be driven by the exhaust steam of the piston steam engine and / or by the exhaust gas (flue gas) of a steam generator connected upstream of the piston steam engine.

[0026] Furthermore, 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, which is designed to set the heat exchange fluid in flow, in particular to flow it through a heat exchange chamber in which the at least one pipe of the tube heat exchanger is arranged.

[0027] Preferably, the supplied fresh steam can be superheated by the superheater to a temperature of 100 ° C to 1000 ° C, more preferably from 300 ° C to 700 ° C. The fresh steam can be supplied to the piston steam engine (1) at a pressure of 30 bar to 800 bar, preferably from 30 bar to 500 bar.

[0028] In one embodiment of the present disclosure, the working chamber is enclosed over its circumference by a working chamber wall inserted into the cylinder or formed by the cylinder, a plurality of first exhaust steam outlet openings are provided distributed in the circumferential direction of the working chamber wall, and a plurality of second exhaust steam outlet openings are provided above the first exhaust steam outlet openings, preferably distributed in the circumferential direction, in the working wall.

[0029] Furthermore, it is preferred that 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 (magnetically), pneumatically or hydraulically operated valve, more preferably a side valve.

[0030] Furthermore, it is advantageous if 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 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. Alternatively, the second exhaust steam outlet openings can be realized by a channel in the cylinder head in conjunction with a valve, e.g. SV arrangement (side valve arrangement).

[0031] It is further preferred that 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.

[0032] Furthermore, it is advantageous if the piston steam engine is controlled such that the second exhaust steam outlet openings are opened by means of the valve up to a range of 30° to 10°, in particular 15° to 10°, before top dead center of the piston stroke, with the second exhaust steam outlet openings preferably being opened shortly before bottom dead center, in particular in a range of 140° to 180° (40° to 0° before BDC). In this case, the compression ratio can be adjusted over a small compression space.

[0033] The inlet valve may have a valve opening that connects the steam chamber and the working chamber, in particular the steam chamber and an inlet side of the superheater, a valve seat surrounding the valve opening, and a movable valve body that interacts with the valve seat to close and open (release) the valve opening. The inlet valve or control valve may be designed as an electric, electronic, hydraulic, or pneumatic valve, or a combination thereof.

[0034] According to a further embodiment, a piston steam engine, which is preferably used for generating electrical power, has: at least one cylinder that encloses a working chamber, a piston that can be moved 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, a plurality of first exhaust steam outlet openings are provided distributed in the circumferential direction of the working chamber wall, and a plurality of second exhaust steam outlet openings, which are arranged above the first exhaust steam outlet openings, preferably distributed in the circumferential direction,is provided in the work wall.,

[0035] Furthermore, the first exhaust steam outlet openings can be opened and closed by the up and down movement of the piston, and / or the second exhaust steam outlet openings can be opened and closed by a valve, in particular a mechanically (e.g. side valve), electrically (magnetically), pneumatically or hydraulically operated valve.

[0036] In this case, it is particularly preferred that 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 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.

[0037] Furthermore, it is advantageous 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 of 5% to 25%, preferably 10% to 20%, of the piston stroke from the top dead center in the direction of the bottom dead center.

[0038] It is further preferred if the piston steam engine is controlled such that the second exhaust steam outlet openings are opened 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, in particular in a range of 140° to 180° (40° to 0° before the bottom dead center).

[0039] It is also preferred if the piston steam engine has a superheater which is arranged between the inlet valve and the working chamber and is designed to superheat the fresh steam flowing through the inlet valve towards the working chamber.

[0040] It is also advantageous if the piston steam engine has a radial turbine or steam turbine connected downstream of the piston steam engine and driven by the exhaust steam from the piston steam engine. Preferably, the pressure of the exhaust steam released by the piston steam engine 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. The installation of the radial turbine creates a backflow in the outlet of the piston steam engine, which increases the pressure of the released steam from approximately 0.15 bar to 0.5 bar.

[0041] Furthermore, it is advantageous if the radial turbine is designed to drive a generator for generating electrical energy, the exhaust steam from the piston steam engine expanded by the radial turbine preferably being fed to a downstream condenser which is designed to condense the exhaust steam. Furthermore, it is preferred that the piston steam engine has a spray cooler which is designed to inject water into the expanded exhaust steam from the radial turbine in order to further lower the temperature of the exhaust steam and thus improve the vacuum. In other words, by injecting water into the exhaust steam from the radial turbine, the temperature is lowered and thus the vacuum is increased, whereby the power of the radial turbine can be increased and thus more electrical power can be generated. This is particularly interesting in the summer months when there is a low heat demand.

[0042] It is also advantageous if the piston steam engine further comprises a crosshead which couples a piston rod, which is preferably rigidly connected to the piston and oscillates translationally (moves back and forth), to a connecting rod which oscillates translationally and rotationally (and at the same time swings out), the crosshead preferably being mounted translationally via its own plain bearing, in particular a sliding block. In this way, the distance between the piston and the engine crankshaft chamber can be increased and thermal insulation can thus be achieved. This is particularly advantageous since the superheater provided operates at temperatures of up to 750 °C and therefore glows. For this reason, the best possible insulation or thermal separation is necessary, e.g. also by means of a ceramic spacer, in particular a zirconium dioxide spacer (ZrCh).

[0043] It is also advantageous if the piston has a suitable design in which the upper part of the piston can glow during operation (temperatures above 500 ° C) but does not rest against the cylinder wall, so that the heat transfer from the hot piston upper part to the cylinder can be reduced. The piston lower part, with sealing and lubrication, takes over the guidance. The upper part of the piston can preferably be made of Inconel (IN718) and the lower part preferably of coated steel. Advantageously, a gap can be provided between the non-restoring piston upper part and the cylinder wall, which gap is in a range of 0.1 mm to 0.3 mm. Accordingly, the upper part of the piston has no piston rings.

[0044] According to a further embodiment, the piston steam engine has a water injection device which has an injection valve and at least one water injection opening, preferably a plurality of water injection openings, which is / are provided in the working chamber wall at the same height or above the first exhaust steam outlet openings, preferably distributed in the circumferential direction. The water is preferably injected at a pressure of 50 to 350 bar, wherein the water is preferably preheated to a temperature of 60° to 90°. It is advantageous if the water is injected in small droplets, which can be achieved by means of a multi-hole nozzle.

[0045] Furthermore, it is advantageous if the piston steam engine is designed to detect an exhaust steam temperature of the exhaust steam released from the piston steam engine and, based on the detected exhaust steam temperature, to determine whether, when and how much water should be injected into the working chamber by means of the water injection device.

[0046] Furthermore, it is preferred if the control valve of the piston steam engine is a springless control valve or at least does not require a spring to fulfill its basic function. In this way, a control valve can be provided in which a valve body, which cooperates with a valve seat to open and close the valve, can be or is subjected to a force against the valve seat purely by a fluid pressure which acts on a side of the valve body facing away from the valve seat. In other words, the control valve according to the invention does not necessarily have a spring element, such as a spring (compression spring), which is designed to apply a closing force to the valve body in a closing direction of the valve.

[0047] Alternatively, a control valve can be used in which the inlet valve or its valve member is opened hydraulically and closed pneumatically. For this purpose, the inlet valve has a valve opening which connects the steam chamber and the working chamber, a valve seat surrounding the valve opening and a movable valve member which interacts with the valve seat to close and open the valve opening. The valve member can comprise a valve stem and a valve body, with the valve body interacting with the valve seat. Furthermore, a valve control is provided for moving the valve member. The valve control comprises a control cylinder and a control piston which interacts with the valve member. The control piston divides the control cylinder into a pneumatic chamber (closing chamber) and a hydraulic chamber (actuation chamber). The pneumatic chamber serves to close the valve opening, with the valve member orThe valve body is pressed into the valve seat by the pneumatic pressure in the pneumatic chamber. The hydraulic chamber can be pressurized with hydraulic fluid to lift the valve element from the valve seat and release the valve opening.

[0048] This makes it possible to control or regulate the opening flank (valve lift or opening as well as speed) of the inlet valve via the hydraulic pressure. In other words, the lift curve (gradient, compression, etc.) can be adjusted as desired to a large extent. At the same time, the pneumatics can achieve a steep closing flank in the lift curve, i.e. the inlet valve closes very quickly (particularly in comparison to a spring). This allows the expansion phase of the steam in the working chamber of the reciprocating piston to be extended and a higher level of efficiency to be achieved. Furthermore, pneumatics are not subject to the above-mentioned disadvantages of a spring, especially a steel spring. The tightness of the inlet valve can therefore be ensured over a very long period of time. In addition, pneumatics enable seals to be comparatively simpler than those used with hydraulics because the gas pressure provides additional sealing.

[0049] The working space is not necessarily to be understood as the maximum total volume limited by the reciprocating piston, but rather as the space in which the supplied fresh steam is expanded.

[0050] Furthermore, the present disclosure relates to a combined heat and power plant which has a steam generator and the steam engine described above, wherein the steam engine is coupled to a generator for generating electrical power.

[0051] Furthermore, the present disclosure relates to a computer-implemented method for controlling and / or regulating a piston steam engine, in particular the piston steam engine described above, wherein the piston steam engine has: at least one cylinder enclosing a working chamber, a piston 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, and a working chamber wall enclosing the working chamber over its circumference, inserted into the cylinder or formed by it, having a plurality of first exhaust steam outlet openings provided distributed in the circumferential direction of the working chamber wall, wherein the method comprises:

[0052] Detecting 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,

[0053] Determining an opening profile of 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, depending on the detected at least one exhaust steam parameter, and / or

[0054] Determining an injection profile of at least one water injection opening, preferably a plurality of water injection openings, 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.

[0055] Furthermore, it is preferred that at least one opening parameter of the opening profile of the second exhaust steam outlet openings is determined or ascertained 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 bottom dead center)), 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 opening and closing degree, and / or at least one injection parameter of the injection profile of the water injection openings is determined or ascertained 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 bottom dead center) ), closing angle (e.g.in a range of 200° to 300° (20° to 120° after bottom dead center), opening duration or injection duration and quantity of water to be injected.

[0056] Furthermore, it is advantageous if the computer-implemented method further comprises: 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.

[0057] Furthermore, it is preferred if the computer-implemented method further comprises:

[0058] 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

[0059] Determining a target value of the at least one detected operating parameter as a function of the detected at least one evaporation parameter and / or at least one further detected operating parameter.

[0060] 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 carrying out the steps of the computer-implemented method described above.

[0061] The present disclosure also relates to a computer program, in particular an application software (app), comprising commands which, when executed by a computer, cause the computer to carry out the above-described computer-implemented method for controlling and / or regulating a piston steam engine.

[0062] Furthermore, the present disclosure relates to a computer-readable storage medium comprising instructions which, when executed by a computer, cause the computer to carry out the above-described computer-implemented method for controlling and / or regulating a piston steam engine.

[0063] Short description of the characters

[0064] Fig. 1 shows a schematic diagram of a combined heat and power plant,

[0065] 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, and

[0066] Fig. 3 shows an enlarged partial view of the schematic sectional view of Fig. 2 to illustrate the arrangement of the superheater according to the invention,

[0067] Fig. 4 shows a schematic diagram of a combined heat and power plant of another embodiment of the present invention,

[0068] Fig. 5 shows an enlarged partial view of the schematic sectional view of Fig. 2 to illustrate the arrangement of the second exhaust steam outlet openings according to the invention, and

[0069] Fig. 6 shows a flow diagram of a computer-implemented method for controlling and / or regulating a piston steam engine according to the invention.

[0070] Detailed description of the preferred embodiments

[0071] 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 be combined individually to form further embodiments. In the various figures, identical or corresponding elements are designated by the same or similar reference numerals.

[0072] 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 relatively large amount of oil.

[0073] 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.

[0074] 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.

[0075] 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.

[0076] 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.

[0077] 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 housed 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.

[0078] 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, which 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, wherein the live steam functions as the working fluid of the piston steam engine 1.Alternatively, the inlet valve 26 can also be designed as an electric, 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.

[0079] 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 in through the inlet valve 26 in the direction of the working chamber 15 and controlled and / or regulated by the inlet valve, and thereby preferably superheats it into the supercritical high-temperature range.

[0080] 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.

[0081] 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.

[0082] 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.

[0083] The use of a liquid metal or a salt bath has the advantage that very large amounts of heat can 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.

[0084] 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, which compressor stage 70 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. In this case, the highest possible flow velocities in the range from 10 to 20 m / s, sometimes up to 50 m / s, are advantageous. 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.

[0085] 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.

[0086] 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.

[0087] Furthermore, as can be seen in Figure 2, the piston steam engine has a plurality of oil injection openings 17 which are introduced into the working chamber wall 14 above the outlet openings 13 and which enable communication between the outside of the working chamber wall 14 and the working chamber 15 which is defined by the working chamber wall 14, an underside of a chamber plate 64 delimiting the heat exchange chamber 63, together with the valve element 27, and an upper side of the piston 30. In the embodiment shown, the outlet openings 13 are arranged on a common imaginary line which runs perpendicular to the central axis CA and is spaced from the outlet openings 13 in the direction of top dead center OT.

[0088] As can be seen from Figure 2, in the embodiment shown, the oil injection openings 17 are evenly distributed over the circumference of the working chamber wall 14. This means that the angle between two adjacent oil injection openings 17 is always the same size. In the embodiment shown, twelve oil injection openings 17 are provided over the circumference of the working chamber wall 14.

[0089] 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.

[0090] 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.

[0091] Additionally or alternatively, as shown in Figure 4, the piston steam engine 1 or the combined heat and power plant 200 can 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 approx. 0.15 bar to 0.5 bar.As can also be seen from Figure 4, the radial turbine 80 serves to drive a generator 130 to generate electrical energy, wherein the exhaust steam of the piston steam engine 1 expanded by the radial turbine is fed to a downstream condenser 150 for condensing the exhaust steam.

[0092] 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.

[0093] 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.

[0094] Figure 4 further shows that the piston steam engine 1 or the combined heat and power plant 200 can optionally be equipped with a water injection device 100 having an injection valve 101 and a plurality of water injection openings 102, wherein the water injection openings 102 are provided at the same height as 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. Figure 6 further shows a flow diagram of a computer-implemented method for controlling and / or regulating a piston steam engine according to an embodiment of the present disclosure. The computer-implemented method shown is used to operate the piston steam engine described above in connection with Figures 1 to 5.As can be seen from Figure 6, the method comprises the following steps:.

[0095] Detection S10 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,

[0096] Determining S20 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, and / or

[0097] Determining S30 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.

[0098] As can be further seen from Figure 6, the computer-implemented method may optionally comprise the following additional steps:

[0099] Determining or determining S40 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 S50 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 UT),

[0100] Opening time or injection time and injected

[0101] Amount of water. Furthermore, as shown in Figure 6, the method may further comprise the step: activating S60 a radial turbine 80 connected downstream of the piston steam engine 1 as a function of the detected at least one exhaust steam parameter, in particular the detected exhaust steam pressure, wherein the downstream radial turbine 80 is activated above a pressure of 1.0 bar, preferably above a pressure of 0.4 bar.

[0102] Furthermore, as Figure 6 shows, the computer-implemented method may comprise the steps:

[0103] Detection S70 of at least one operating parameter of the piston steam engine 1 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 70, speed of the centrifugal pump and oil temperature of the piston steam engine, and

[0104] Determining S80 a setpoint value of the at least one detected operating parameter as a function of the detected at least one evaporation parameter and / or at least one further detected operating parameter.

[0105] 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, the person 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.

[0106] Furthermore, the invention has been described with reference to specific embodiments, which are intended only to provide a better 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.

[0107] List of reference symbols

[0108] 1 piston steam engine

[0109] 10 cylinders

[0110] 13 first steam outlet openings

[0111] 14 Workroom wall

[0112] 15 work space

[0113] 18 second steam outlet openings

[0114] 19 Valve (control valve for second exhaust steam outlet openings)

[0115] 26 Inlet valve

[0116] 27 Valve body

[0117] 28 Valve opening

[0118] 29 Valve seat

[0119] 30 pistons

[0120] 60 superheaters

[0121] 61 tube heat exchangers

[0122] 62 pipes of the tube heat exchanger

[0123] 62A Opening

[0124] 63 Heat exchange chamber

[0125] 70 compressor stage

[0126] 76 Steam room

[0127] 80 Radial turbine

[0128] 90 Spray cooler Water injection device Injection valve Water injection openings Steam generator Generator Condenser

Claims

Patent claims 1. Piston steam engine (1), which is preferably used for the generation of 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, a plurality of first exhaust steam outlet openings (13) which are provided distributed in the circumferential direction of the working chamber wall (14), and a plurality of second exhaust steam outlet openings (18) which are arranged above the first Exhaust steam outlet openings (13),preferably distributed in the circumferential direction, are provided in the working space wall (14)., 2. Piston steam engine (1) according to claim 1, 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, can be opened and closed.

3. Piston steam engine (1) according to claim 1 or 2, wherein the second exhaust steam outlet openings (18) are arranged in a first annular region which extends in the circumferential direction of the working chamber wall (14), in particular perpendicular to Central axis (CA) 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 (CA), wherein the second exhaust steam outlet openings (18) preferably have a diameter of 10 to 20 mm.

4. Piston steam engine (1) according to claim 3, wherein 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 from the top dead center (OT) in the direction of the bottom dead center (OT) by 5% to 25%, preferably 10% to 20%, of the piston stroke.

5. Piston steam engine (1) according to one of claims 1 to 4, wherein the piston steam engine (1) is controlled such that the second exhaust steam outlet openings (18) (by means of the valve (19)) are opened up to a range of 20° to 10°, in particular 15° to 10°, before the top dead center (TDC) of the piston stroke, wherein the second exhaust steam outlet openings (18) are preferably opened shortly before the bottom dead center (UT), in particular in a range of 140° to 180° (40° to 0° before BDC).

6. Piston steam engine (1) according to one of claims 1 to 5, 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).

7. Piston steam engine (1) according to one of the preceding claims, further comprising a radial turbine (80) which is connected downstream of the piston steam engine (1) and is driven by the exhaust steam of the piston steam engine (1), wherein preferably the pressure of the exhaust steam discharged from the piston steam engine (1) 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.

8. Piston steam engine (1) according to claim 7, wherein the radial turbine (80) is designed to drive a generator (130) for generating electrical energy, wherein the exhaust steam of the piston steam engine (1) expanded by the radial turbine is preferably fed to a downstream condenser (150) which is designed to condense the exhaust steam.

9. Piston steam engine (1) according to claim 7 or 8, further comprising a spray cooler (90) which is designed to inject water, in particular finely atomized water, into the expanded exhaust steam of the radial turbine (80) in order to reduce the temperature of the exhaust steam and thus the pressure of the exhaust steam.

10. Piston steam engine (1) according to one of the preceding claims, further comprising: a crosshead which couples a piston rod connected to the piston (30) and oscillating in translation to a connecting rod which oscillates in translation and rotation (and at the same time also pivots out), wherein the crosshead is preferably mounted in translation via its own sliding bearing, in particular a sliding shoe.

11. Piston steam engine (1) according to one of the preceding claims, further comprising: a 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.

12. Piston steam engine (1) according to claim 11, which is designed to detect an exhaust steam temperature of the exhaust steam discharged from the piston steam engine (1) and to determine, based on the detected exhaust steam temperature, whether, when and how much water should be injected into the working chamber (15) by means of the water injection device (100).

13. 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 12, wherein the piston steam engine (1) is coupled to a generator (130) for generating electrical power.

14. A computer-implemented method for controlling and / or regulating a piston steam engine, in particular the piston steam engine (1) according to one of claims 1 to 12, comprising: at least one cylinder (10) enclosing a working chamber (15), a piston (30) 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, and a working chamber wall (14) enclosing the working chamber (15) over its circumference, inserted into the cylinder (10) or formed by it, comprising a plurality of first exhaust steam outlet openings (13) provided distributed in the circumferential direction of the working chamber wall (14), the method 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 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 space wall (14), depending on the detected at least one exhaust steam parameter, 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), as a function of the detected at least one exhaust steam parameter.

15. Computer-implemented method according to claim 14, wherein at least one opening parameter of the opening profile of the second exhaust steam outlet openings (18) is determined or ascertained 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 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 exhaust steam 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.

16. A computer-implemented method according to claim 14 or 15, further comprising: Activating a radial turbine (80) downstream of the piston steam engine (1) depending on the detected at least one exhaust steam parameter, in particular the detected exhaust steam pressure, wherein the downstream radial turbine (80) is preferably activated above a pressure of 1.0 bar, preferably above a pressure of 0.4 bar.

17. A computer-implemented method according to any one of claims 14 to 16, further comprising: Detection of at least one operating parameter of the piston steam engine (1) 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 (70), speed of the centrifugal pump and oil temperature of the piston steam engine, and Determining a target value of the at least one detected operating parameter as a function of the detected at least one evaporation parameter and / or at least one further detected operating parameter.

18. 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 14 to 17.

19. Computer program, in particular application software (app), comprising instructions which, when executed by a computer, cause the computer to carry out the computer-implemented method for controlling and / or regulating a piston steam engine (1) according to one of the preceding claims 14 to 17.

20. Computer-readable storage medium comprising instructions which, when executed by a computer, cause the computer-implemented method for controlling and / or Control of a piston steam engine (1) according to one of the preceding claims 14 to 17.

Images