Axial-piston engine, method for operating an axial-piston engine, and method for producing a heat exchanger of an axial-piston engine

Abstract

The aim of the invention is to improve the efficiency of an axial-piston motor comprising at least one working cylinder fed by a continuously operating combustion chamber comprising a pre-combustion chamber and a main combustion chamber. To this end, the axial-piston motor is provided with a pre-combustion chamber comprising a check valve.

Claims

1. An axial-piston engine with at least one compressor cylinder, with at least one working cylinder, and with at least one pressure line, through which compressed combustion agent is conducted from the compressor cylinder to the working cylinder, the axial-piston engine comprising a combustion agent reservoir in which compressed medium can be stored temporarily, the axial-piston engine further comprising a first heat exchanger, a second heat exchanger, a first valve for the first heat exchanger, and a second valve for the second heat exchanger, wherein exhaust channels lead from the working cylinders to said first and second heat exchanger, and wherein the combustion agent reservoir is provided between the compressor cylinder and the first heat exchanger and is provided between the compressor cylinder and the second heat exchanger; and wherein the first heat exchanger or the second heat exchanger is in the pressure line for heating up compressed gas; and wherein the first valve is situated a) between the combustion agent reservoir and the compressor cylinder and also situated between the combustion agent reservoir and a combustion chamber and b) wherein the second valve is situated between the combustion agent reservoir and the compressor cylinder.

2. The axial-piston engine according to claim 1, wherein said at least one working cylinder, is fed from a continuously working combustion chamber that includes a precombustion chamber and a main combustion chamber into which fuel being thermally decomposed by a flame in said precombustion chamber is injected, wherein the precombustion chamber includes a mixing pipe for mixing fuel and combustion air and a fuel processing system which is situated ahead of said mixing pipe, and wherein the fuel processing system vaporizes fuel inserted into the precombustion chamber before entry into the precombustion chamber when said fuel has not already come into contact with combustion air.

3. The axial-piston engine according to claim 2, wherein the fuel processing system is situated ahead of a mixing pipe for mixing fuel and other combustible substances.

4. The axial-piston engine according to claim 2, wherein the combustion air fed to the precombustion chamber is tempered by a combustion agent processing system.

5. The axial-piston engine according to claim 4, wherein the combustion agent processing system includes a combustion agent heater, for example a glow plug, a glow coil, an induction heater or a laser heater.

6. The axial-piston engine according to claim 2, wherein the precombustion chamber has an eccentric combustion agent input.

7. The axial-piston engine according to claim 2, wherein the precombustion chamber has two combustion air inputs.

8. The axial-piston engine according to claim 7, wherein the two combustion-air inputs are designed for differently tempered combustion air.

9. The axial-piston engine according to claim 1, further comprising a third valve, the third valve being situated between the compressor cylinder and the combustion agent reservoir.

10. The axial-piston engine according to claim 1, comprising at least two combustion agent reservoirs.

11. The axial-piston engine according to claim 10, wherein the at least two combustion agent reservoirs are charged with different pressures.

12. The axial-piston engine according to claim 11, comprising a pressure regulating system that defines a first lower pressure limit and a first upper pressure limit for the first combustion agent reservoir, and a second lower pressure limit and a second upper pressure limit for the second combustion agent reservoir, within which the first combustion agent reservoir and the second combustion agent reservoir are pressurized, wherein the first upper pressure limit is lower than the second upper pressure limit and the first lower pressure limit is preferably lower than the second lower pressure limit.

13. The axial-piston engine according to claim 12, wherein the first upper pressure limit is lower than or equal to the second lower pressure limit.

14. The axial-piston engine according to claim 1, wherein the first heat exchanger and the second heat exchanger are in the pressure line for heating up compressed gas.

Description

(1) The figures show the following:

(2) FIG. 1 a schematic sectional view of a fuel heating system of an axial-piston engine for its preburner;

(3) FIG. 2 a schematic sectional view of a check valve ahead of a precombustion chamber of an axial-piston engine;

(4) FIG. 3 a schematic sectional view of an axial-piston engine with two heat exchangers, on which the assemblies from FIGS. 1 and 2 can be used advantageously;

(5) FIG. 4 a schematic sectional view of an axial-piston engine with two heat exchangers and with a combustion agent reservoir, on which the assemblies from FIGS. 1 and 2 can be used advantageously;

(6) FIG. 5 a schematic sectional view of another axial-piston engine, on which the assemblies from FIGS. 1 and 2 can likewise be used advantageously; and

(7) FIG. 6 a schematic depiction of a flange for a heat exchanger, with a matrix situated in it to receive pipes of a heat exchanger.

(8) The fuel processing system 980 shown in FIG. 1 is placed ahead of a precombustion chamber 927 of an axial-piston engine 901, and includes a fuel heater 981 in the form of a glow plug 982. The glow plug 982 corresponds in this case to a mixing pipe 983 for mixing of fuel 928 and combustion air 929. The combustion air 929 is fed to the mixing pipe 983 by means of a combustion air supply 984 that is axially flush therewith. To supply the fuel 928, the fuel processing system 980 includes a fuel injection system 985 with a processing nozzle 912, which is placed radially to the mixing pipe 983. Arranged in this way, the processing nozzle 912 can apply the fuel 928 to a vaporizer 986, whereby the fuel 928 can be vaporized especially effectively by means of the glow plug 982 before it is fed to the mixing pipe 983.

(9) Combustion agents mixed in this mannerfuel 928 and combustion air 929can then be applied to the precombustion chamber 927, to burn there completely for example by self-ignition. In particular in a starting phase of the axial-piston engine 901, specifically when the axial-piston engine 901 is still cold and far from its operating temperature, the ignition of the combustion agent can be made easier by having a spark plug 987 ignite the combustion agent. To this end, the spark plug 987 projects into the precombustion chamber 927 on the input side. Alternatively, such a spark plug 987 can also be assigned to a mixing pipe 983 and project into the mixing pipe 983 accordingly.

(10) In the area of the fuel injection system 985 a cooling system 988 is also provided, by means of which overheating of the fuel injection system 985 can be prevented effectively.

(11) According to the schematic sectional view of FIG. 2, in the second exemplary embodiment a check valve 1095 is provided ahead of a precombustion chamber 1027 of an axial-piston engine 1001, whereby the check valve 1095 comprises in a known manner a valve seat 1096 and a corresponding ceramic valve ball 1097. Otherwise the fuel processing system 1080 corresponds to the fuel processing system 980.

(12) In this exemplary embodiment the check valve 1095 is situated between a mixing pipe 1083 of a fuel processing system 1080 and a combustion air supply system 1084 axially flush therewith.

(13) The fuel processing system 1080 includes a fuel heater 1081 in the form of a glow plug 1082 and a processing nozzle 1012 with a vaporizer 1086. By means of the glow plug 1082, a fuel injected by the processing nozzle 1012 can be vaporized in the vaporizer 1086 before it is fed to the mixing pipe 1083 in gaseous form.

(14) In particular during starting processes of the axial-piston engine 1001, the check valve 1095 can contribute to making combustion of combustion agents within the precombustion chamber 1027 uniform, wherein ignition of the combustion agents applied to the precombustion chamber 1027 can be further improved or supported by means of an additional spark plug 1087.

(15) Both the fuel processing system 980 described in FIG. 1 as an example and the check valve 1095 described in FIG. 2 as an example can be used advantageously on axial-piston engines of almost any configuration with at least one working cylinder, that is fed from one continuously working combustion chamber and is equipped with a precombustion chamber and a main combustion chamber, in order to improve the respective efficiency of such an axial-piston engine. Only three axial-piston engines 201, 401 and 501 will now be explained by way of example, in which the fuel processing system 980 and the check valve 1085 can be used advantageously.

(16) In this case in particular the mixing pipes 983, 1083 can also discharge eccentrically into the precombustion chambers 927, 1027. The spark plugs 987, 1087 can likewise be provided in the mixing pipes 983, 1083 or at some other suitable location.

(17) The axial-piston engine 201 depicted as an example in FIG. 3 has a continuously working combustion chamber 210, from which working medium is fed successively via shot channels 215 (numbered as an example) to working cylinders 220 (numbered as an example). Situated in each of the working cylinders 220 are respective working pistons 230 (numbered as an example), which are connected on the one hand by way of a straight connecting rod 235 to an output, which is realized in this exemplary embodiment as a spacer 242 carrying a curved track 240, situated on an output shaft 241, and are connected on the other hand to a compressor piston 250, each of which runs in the compressor cylinder 260 in a manner explained in greater detail below.

(18) After the working medium has performed its work in working cylinder 220 and has placed a load on working piston 230 accordingly, the working medium is expelled from the working cylinder 220 through exhaust gas channels 225. Provided on the exhaust gas channels 225 are temperature sensors, not shown, which measure the temperature of the exhaust gas.

(19) The exhaust gas channels 225 discharge in each instance into heat exchangers 270, and subsequently leave the axial-piston engine 201 at appropriate outlets 227 in a known manner. The outlets 227 for their part can be connected again in particular to an ring channel, not shown, so that in the end the exhaust gas leaves the engine 201 at only one or two places. Depending on the concrete configuration in particular of the heat exchanger 270, a sound damper can possibly also be dispensed with, since the heat exchangers 270 themselves already have a sound-damping effect.

(20) The heat exchangers 270 serve to preheat combustion agent which is compressed in the compressor cylinders 260 by the compressor pistons 250 and conducted through a pressure line 255 to the combustion chamber 210. The compression takes place in this case in a known manner, by the fact that supply air is drawn in through supply lines 257 (numbered as an example) by the compressor pistons 250 and compressed in the compressor cylinders 260. Known and readily appropriately utilizable valve systems are used to this end.

(21) The axial-piston engine 201 has two heat exchangers 270, which in each instance are situated axially in reference to the axial-piston engine 201. Through this arrangement, the paths which the exhaust gas must traverse through the exhaust gas channels 225 to the heat exchangers 270 can be reduced significantly, compared to state-of-the-art axial-piston engines. The result of this is that in the end the exhaust gas reaches the respective heat exchanger 270 at a significantly higher temperature, so that in the end the combustion agent can also be preheated to correspondingly higher temperatures. In practice, it has been found that at least 20% of fuel can be saved through such a configuration. It is assumed in this connection that even savings of up to 30% or more are possible by means of an optimized design.

(22) In this connection it is understood that the efficiency of the axial-piston engine 201 can be increased through additional measures. For example, the combustion agent can be used in a known manner for cooling or thermally insulating the combustion chamber 210, whereby its temperature can be increased still further before it enters the combustion chamber 210. Let it be emphasized here that the corresponding tempering can be limited on the one hand only to components of the combustion agent, as is the case in the present exemplary embodiment in reference to combustion air. It is also conceivable to apply water to the combustion air already before or during the compression; this is also readily possible afterwards, however, for example in the pressure line 255.

(23) Especially preferably, the application of water to the compressor cylinder 260 takes place during an intake stroke of the corresponding compressor piston 250, which results in isothermal compression, or compression as close as possible to isothermal compression. As is directly apparent, each working cycle of the compressor piston 250 comprises an intake stroke and a compression stroke, wherein during the intake stroke combustion agent enters the compressor cylinder 260, which is then compressed, i.e., compressed, during the compression stroke, and conveyed into the pressure line 255. By application of water during the intake stroke, a uniform distribution of the water can be ensured in an operationally simple manner.

(24) Preferably, the fuel is processed as described above. This can be dispensed with, however, depending on the concrete exemplary embodiment.

(25) The application of water in this configuration can also take place in the pressure line 255, wherein the water mixes uniformly with the combustion agent within the heat exchanger due to appropriate deflection of the flow. The exhaust gas channel 225 can also be chosen for the application of water or of another fluid, such as fuel or means for exhaust gas aftertreatment, in order to ensure a homogeneous mixing within the heat exchanger 270. The configuration of the depicted heat exchanger 270 also allows aftertreatment of the exhaust gas in the heat exchanger itself, wherein heat released by the aftertreatment is supplied directly to the combustion agent present in the pressure line 255. Situated in the outlet 227 is a water trap, not shown, which returns the condensed water present in the exhaust gas to the axial-piston engine 201 for renewed application. The water trap can of course be realized in combination with a condenser. Furthermore, use with similarly designed axial-piston engines is of course possible, wherein the other advantageous features of the axial-piston engine 201 or of similar axial-piston engines are advantageous even without use of a water trap in the outlet 227.

(26) The axial-piston engine 401 shown only as an example in FIG. 4 also corresponds essentially to the axial-piston engine 201 according to FIG. 3. Accordingly, identically or similarly working assemblies are labeled similarly, and differ only in the first digit. Accordingly, in other respects a detailed explanation of the mode of operation will also be dispensed with for this exemplary embodiment, since that was already done in reference to the axial-piston engine 201 according to FIG. 3.

(27) The axial-piston engine 401 also includes a housing body 405, on which a continuously working combustion chamber 410, six working cylinders 420 and six compressor cylinders 460 are provided. In this case the combustion chamber 410 is connected via shot channels 415 to the working cylinders 420, in each instance, so that working medium can be fed to the working cylinders 420 corresponding to the timing rate of the axial-piston engine 401.

(28) After its work is done, the working medium leaves the working cylinders 420 in each instance through exhaust gas channels 425, which lead to heat exchangers 470, wherein these heat exchangers 470 are arranged identically to the heat exchangers 270 of the axial-piston engine 201 according to FIG. 3. The working medium leaves the heat exchangers 470 through outlets 427 (numbered as an example).

(29) Situated in the working cylinders 420 and the compressor cylinders 460 are working pistons 430 and compressor pistons 450, respectively, which are connected with one another by means of a rigid connecting rod 435. The connecting rod 435 includes in a known manner a curved track 440, which is provided on a spacer 424, which ultimately drives an output shaft 441.

(30) In this exemplary embodiment also, combustion air is drawn in through supply lines 457 and compressed in the compressor cylinders 460, in order to be applied via pressure lines 455 to the combustion chamber 410, wherein the measures named in the case of the aforementioned exemplary embodiment can likewise be provided, depending on the concrete implementation.

(31) In addition, in the case of the axial-piston engine 401 the pressure lines 455 are connected with one another via an ring channel 456, whereby a uniform pressure in all pressure lines 455 can be guaranteed in a known manner. Between the ring channel 456 and each of the pressure lines 455 valves 485 are provided in each instance, wherein the supply of combustion agent can be regulated or set by the pressure lines 455. Furthermore, a combustion agent reservoir 480 is connected to the ring channel 456 via a reservoir line 481, in which a valve 482 is likewise situated.

(32) The valves 482 and 485 can be opened or closed, depending on the operating state of the axial-piston engine 401. Thus it is conceivable, for example, to close one of the valves 485 when the axial-piston engine 401 needs less combustion agent. It is also conceivable to partially close all valves 485 in such operating situations, and to let them operate as throttles. The surplus of combustion agent can then be fed to the combustion agent reservoir 480 when valve 482 is open. The latter is also possible in particular when the axial-piston engine 401 is running under deceleration, i.e., when no combustion agent at all is needed, but rather it is being driven via the output shaft 441. The surplus of combustion agent caused by the movement of the compressor pistons 450 that occurs in such an operating situation can likewise readily be stored in the combustion agent reservoir 480.

(33) The combustion agent stored in this way can be fed supplementally to the axial-piston engine 401 as needed, i.e., in particular in driving off or acceleration situations, as well as for starting, so that a surplus of combustion agent is provided without additional or more rapid movements of the compressor pistons 450.

(34) The valves 482 and 485 can also be dispensed with, if appropriate, to guarantee the latter. Foregoing such valves for prolonged storage of compressed combustion agent seems little suited, due to unavoidable leakage.

(35) In an alternative embodiment to the axial-piston engine 401, the ring channel 456 can be dispensed with, whereby the outlets of the compressor cylinders 460 are then combined corresponding to the number of pressure lines 455possibly by means of a section of ring channel. With a configuration of this sort it may possibly make sense to connect only one of the pressure lines 455, or not all of the pressure lines 455, to the combustion agent reservoir, or to provide them as connectible. Such a configuration means, however, that not all compressor pistons 450 can fill the combustion agent reservoir 480 during deceleration. On the other hand, sufficient combustion agent is then available to the combustion chamber 410 so that combustion can be maintained without additional regulating or control measures. Simultaneously with this, the combustion agent reservoir 480 is filled by means of the other compressor pistons 450, so that combustion agent is stockpiled accordingly and is available immediately, in particular for starting, driving off or acceleration phases.

(36) It is understood that the axial-piston engine 401, in a different alternative embodiment not shown explicitly here, can be equipped with two combustion agent reservoirs 480, wherein the two combustion agent reservoirs 480 can then also be charged with different pressures, so that it is always possible with the two combustion agent reservoirs 480 to work with different pressure intervals in real time. Preferably a pressure regulating system is provided in this case, which sets a first lower pressure limit and a first upper pressure limit for the first combustion agent reservoir 480, and a second lower pressure limit and a second upper pressure limit for the second combustion agent reservoir (not shown here), within which a combustion agent reservoir 480 is charged with pressures, wherein the first upper pressure limit is below the second upper pressure limit and the first lower pressure limit is below the second lower pressure limit. Specifically, the first upper pressure limit can be set lower than or equal to the second lower pressure limit.

(37) Not shown explicitly in FIGS. 3 and 4 are temperature sensors for measuring the temperature of the exhaust gas or in the combustion chamber. For such temperature sensors, all temperature sensors can be considered which can operationally reliably measure temperatures between 800 C. and 1,100 C. In particular, if the combustion chamber comprises a precombustion chamber and a main combustion changer, the temperature of the precombustion chamber can be measured by means of such temperature sensors. In this respect, the axial-piston engines 201 and 401 described above can each be regulated by means of the temperature sensors in such a way that the exhaust gas temperature when leaving the working cylinders 220 and 420 is approximately 900 C., and the temperature in the precombustion chamberif presentis approximately 1,000 C.

(38) In the case of the other axial-piston engine 501 shown as an example according to the depiction in FIG. 5, such temperature sensors are present in the form of a prechamber temperature sensor 592 and two exhaust gas temperature sensors 593, and are depicted schematically accordingly. In particular by means of the prechamber temperature sensor 592which in this exemplary embodiment can also be referred to as preburner temperature sensor 592, due to its proximity to a preburner 517 of the other axial-piston engine 501a meaningful value concerning the quality of combustion or with regard to the running stability of the other axial-piston engine 501 is ascertained. For example, a flame temperature can be measured in the preburner 517, in order to be able to regulate different operating states in the other axial-piston engine 501 by means of a combustion chamber regulating system. By means of the exhaust gas temperature sensors 593, which are positioned at outlets or exhaust gas channels 525 of the respective working cylinder 520, specifically the operating state of the combustion chamber 510 can be checked cumulatively and regulated if necessary, so that optimal combustion of the combustion agents is always ensured.

(39) Otherwise, the construction and operating principle of the other axial-piston engine 501 correspond to those of the previously described axial-piston engines. In this respect, the other axial-piston engine 501 has a housing body 505, on which a continuously working combustion chamber 510, six working cylinders 520 and six compressor cylinders 560 are provided.

(40) Inside the combustion chamber 510, combustion agents can be both ignited and burned, wherein the combustion chamber 510 can be charged with combustion agents in the manner described above. Advantageously, the other axial-piston engine 501 works with a two-stage combustion system, to which end the combustion chamber 510 has the previously already mentioned preburner 517 and a main burner 518. Combustion agents can be injected into the preburner 517 and into the main burner 518, wherein a proportion of combustion air of the axial-piston engine 501, which specifically in this exemplary embodiment can be smaller than 15% of the total combustion air, can also be introduced in particular into the preburner 517. Preferably, the pressure at which the combustion air is applied to the preburner 517 is higher than the pressure at which combustion air is applied to the main burner 518. This can be achieved especially easily by using line systems with appropriately differing flow resistances for the corresponding supply lines. In particular, a shorter heat exchanger or even none at all can be used for example for the combustion air applied to the preburner 517, while the combustion air applied to the main burner 518 is conducted through the heat exchanger depicted in the drawing.

(41) The preburner 517 has a smaller diameter than the main burner 518, wherein the combustion chamber 510 has a transition area that comprises a conical chamber 513 and a cylindrical chamber 514.

(42) To supply combustion agents and combustion air, on the one hand a main nozzle 511 and on the other hand a processing nozzle 512 discharge into the combustion chamber 510, in particular into the associated conical chamber 513. By means of the main nozzle 511 and the processing nozzle 512, combustion agents or combustible substance can be injected into the combustion chambers 510, wherein in this exemplary embodiment the combustion agents injected by means of the processing nozzle 512 are mixed with combustion air via a perforated ring 523.

(43) The main nozzle 511 is aligned essentially parallel to a main combustion direction 502 of the combustion chamber 510. Furthermore, the main nozzle 511 is aligned coaxially to an axis of symmetry 503 of the combustion chamber 510, wherein the axis of symmetry 503 lies parallel to the main combustion direction 502.

(44) Furthermore, the processing nozzle 512 is situated at an angle (not sketched in explicitly here for the sake of clarity) with respect to the main nozzle 511, so that a jet direction 516 of the main nozzle 511 and a jet direction 519 of the processing nozzle 512 intersect at a mutual point of intersection within the conical chamber 513. In this way, the fuel can be processed from the main nozzle 511 through the preburner 517, and in particular is thermally decomposed before it arrives in the combustion space 526.

(45) Combustible substance or fuel is injected from the main nozzle 511 into the main burner 518 in this exemplary embodiment without further air supply, and is thermally decomposed by the preburner 517, as already explained earlier. To this end, the volume of combustion air corresponding to the quantity of combustible substance flowing through the main nozzle 511 is introduced into a combustion space 526 behind the preburner 517 or the main burner 518, to which end a separate combustion air supply system 504 is provided, which discharges into the combustion space 526.

(46) To this end, the separate combustion air supply system 504 is connected to a process air supply 521, which is carried to the heat exchanger, not shown here, wherein another combustion air supply 522 can be supplied with combustion air directly from the compressor or compressor piston 550, which in this case supply a perforated ring 523 with combustion air. The perforated ring 523 is assigned in this case to the processing nozzle 512. In this respect, the combustible substance injected with the processing nozzle 512, mixed additionally with process air, can be injected into the preburner 517 or into the conical chamber 513 of the main burner 518.

(47) In addition, the combustion chamber 510, in particular the combustion space 526, includes a ceramic assembly 506, which is advantageously air-cooled. The ceramic assembly 506 includes in this case a ceramic combustion chamber wall 507, which in turn is surrounded by a profiled pipe 508. Around this profiled pipe 508 extends a cooling air chamber 509, which is connected to the process air supply system 521 by means of a cooling air chamber supply system 524.

(48) The known working cylinders 520 carry corresponding working pistons 530, which are mechanically connected in each case with compressor pistons by means of connecting rods 535.

(49) In this exemplary embodiment the connecting rods 535 include connecting rod running wheels 536, which run along a curved track 540, while the working pistons 530 or the compressor pistons 550 are moved. An output shaft 541 is thereby set in rotation, which is connected to the curved track 540 by means of a driving curved track carrier 537. Power produced by the axial-piston engine 501 can be delivered via the output shaft 541.

(50) In a known way, by means of the compressor pistons 550 compression of the process air occurs, also including injected water if appropriate, which can be used if necessary for additional cooling. If the application of water or of water vapor occurs during an intake stroke of the corresponding compressor piston 550, isothermal compression of the combustion agent can specifically be promoted. An application of water that accompanies the intake stroke can ensure an especially uniform distribution of the water within the combustion agent, in an operationally simple manner.

(51) Exhaust gases can be cooled significantly more deeply thereby, if necessary, in one or more heat exchangers not depicted here (but see FIG. 4), if the process air is to be prewarmed by means of one or more such heat exchangers and carried to the combustion chamber 510 as combustion agent, as already described in detail for example in the exemplary embodiment explained above for FIG. 4. The exhaust gases can be fed to the heat exchanger or heat exchangers via the exhaust gas channels 525 named above, wherein the heat exchangers are arranged axially in reference to the other axial-piston engine 501.

(52) In addition, the process air can be further prewarmed or heated through a contact with additional assemblies of the axial-piston engine 501 that must be cooled, as has also already been explained. The process air compressed and heated in this way is then applied to the combustion chamber 510 in a manner that has already been explained, whereby the efficiency of the other axial-piston engine 501 can be further increased.

(53) Each of the working cylinders 520 of the axial-piston engine 501 is connected via a shot channel 515 to the combustion chamber 510, so that an ignited fuel-air mixture can pass out of the combustion chamber 510 via the shot channels 515 into the respective working cylinder 520 and can perform work on the working pistons 530 as a working medium.

(54) In this respect, the working medium flowing from the combustion chamber 510 can be fed via at least one shot channel 515 successively to at least two working cylinders 520, wherein for each working cylinder 520 one shot channel 515 is provided, which is closed and opened by means of a control piston 531. Thus the number of control pistons 531 of the other axial-piston engine 501 is predetermined by the number of working cylinders 520. Closing the shot channel 515 is done in this case by means of the control piston 531, including its control piston cover 532. The control piston 531 is driven by means of a control piston curved track 533, wherein a spacer 534 for the control piston curved track 533 to the output shaft 541 is provided, which also serves in particular for thermal decoupling. In the present exemplary embodiment of the other axial-piston engine 501, the control piston 531 can perform an essentially axially directed stroke motion 543. To this end, each of the control pistons 531 is guided by means of sliders, not further labeled, which are supported in the control piston curved track 533, wherein the sliders each have a safety cam that runs back and forth in a guideway, not further labeled, and prevents turning of the control piston 531.

(55) Since the control piston 531 comes into contact in the area of the shot channel 515 with the hot working medium from the combustion chamber 510, it is advantageous if the control piston 531 is water-cooled. To this end, the other axial-piston engine 501 has a water cooling system 538, in particular in the area of the control piston 531, wherein the water cooling system 538 includes inner cooling channels 545, middle cooling channels 546 and outer cooling channels 547. Well cooled in this way, the control piston 531 can be moved operationally reliably in a corresponding control piston cylinder.

(56) Furthermore, the surfaces of the control piston 531 that are in contact with combustion agent are reflective, or are provided with a reflective coating, so that a heat input into the control pistons 531 that occurs by way of heat radiation is minimized. The other surfaces of the shot channels 515 and of the combustion chamber 510 that are in contact with combustion agents in this exemplary embodiment (likewise not shown) are also provided with a coating with elevated spectral reflectivity. This applies in particular to the combustion chamber floor (not labeled explicitly), but also to the ceramic combustion chamber wall 507. It is understood that this configuration of the surfaces that are in contact with combustion agent can also be present in an axial-piston engine, independently of the other configuration features. It is understood that in modified embodiments additional assemblies can also be reflective, or else that the aforenamed reflectivenesses can be at least partially dispensed with.

(57) The shot channels 515 and the control pistons 531 can be provided using especially simple configuration, if the other axial piston engine 501 has a shot channel ring 539. In this case the shot channel ring 539 has a middle axis, around which in particular the parts of the working cylinders 520 and of the control piston cylinders are arranged concentrically. Between each working cylinder 520 and control piston cylinder a shot channel 515 is provided, wherein every shot channel 515 is spatially connected to a cutout (not labeled here) of a combustion chamber floor 548 of the combustion chamber 510. In this respect, the working medium can pass from the combustion chamber 510 via the shot channels 515 into the working cylinders 520 and there perform work, by means of which the compressor pistons 550 can also be moved. It is understood that coatings and inserts can also be provided, depending on the concrete configuration, in order to protect in particular the shot channel ring 539 or its material from direct contact with corrosive combustion products or with excessively high temperatures. The combustion chamber floor 548 in turn can be characterized by another ceramic or metallic coating, in particular reflectiveness, on its surface, which on the one hand reduces the heat radiation occurring from the combustion chamber 510 by increasing the reflectivity, and on the other hand reduces the heat conduction by lowering the thermal conductivity.

(58) It is understood that the other axial-piston engine 501 for example can likewise be equipped with at least one combustion fuel reservoir and corresponding valves, although this is not shown explicitly in the concrete exemplary embodiment according to FIG. 6. In addition, in the case of the other axial-piston engine the combustion agent reservoir can be provided in a double version, in order to be able to store compressed combustion agents at different pressures. The two existing combustion agent reservoirs can be connected in this case to corresponding pressure lines of the combustion chamber 510, wherein the combustion agent reservoirs are fluid-connectible with or separable from the pressure lines by means of valves. Stop valves or throttle valves, or regulating or control valves, can be provided in particular between the working cylinders 520 or compressor cylinders 560 and the combustion agent reservoir. For example, the aforementioned valves can be opened or closed appropriately during driving-off or acceleration situations, as well as for starting, whereby a surplus of combustion agent can be made available to the combustion chamber 510, at least for a limited period of time. The combustion agent reservoirs are interconnected fluidically preferably between one of the compressor cylinders and one of the heat exchangers. The two combustion agent reservoirs are ideally operated at different pressures, in order thereby to be able to make very good use of the energy provided by the other axial-piston engine 501 in the form of pressure. To this end, the provided upper pressure limit and lower pressure limit at the first combustion agent reservoir can be set by means of an appropriate pressure regulating system below the upper pressure limits and lower pressure limits of the second combustion agent reservoir. It is understood that in this case work can be done on the combustion agent reservoirs with different pressure intervals.

(59) Not shown in the drawing is a thermal insulation of the heat exchangers 270, 470, or of the heat exchangers, not shown, of the axial-piston engine 501. To this end, an asbestos substitute is placed in an appropriate manner around the respective heat exchangers, which is subsequently secured by a housing. This ensures that with these exemplary embodiments the external temperature of the axial-piston engine does not exceed 450 C. in the vicinity of the heat exchangers under nearly all operating conditions. The only exceptions are overload situations, which occur only briefly anyway. In this case, the thermal insulation is designed to ensure a temperature gradient of 350 C. at the hottest place on the heat exchanger.

(60) FIG. 6 shows a heat exchanger head plate 3020 which is suitable for use for a heat exchanger for an axial-piston engine. For the purpose of mounting on and connection to an output manifold of an axial-piston engine, the heat exchanger head plate 3020 includes a flange 3021 with corresponding bore holes 3022 arranged in a circle of holes in the radially outer area of the heat exchanger head plate 3020. In the radially inner area of the flange 3021 is the matrix 3023, which has numerous bore holes designed as pipe seats 3024 for accommodation of pipes.

(61) The entire heat exchanger head plate 3020 is preferably made from the same material from which the pipes are also made, in order to ensure that the thermal expansion coefficient is as homogeneous as possible in the entire heat exchanger and that thermal stresses in the heat exchanger are thereby minimized. Cumulatively to this, the jacket housing of the heat exchanger can likewise be produced from a material that corresponds to the heat exchanger head plate 3020 or to the pipes. The pipe seats 3024 can be designed for example with a fit such that the pipes mounted in these pipe seats 3024 are inserted by means of a press fit.

(62) Alternatively to this, the pipe seats 3024 can also be designed so that a clearance fit or a transition fit is realized. In this way, installation of the pipes in the pipe seats 3024 can be carried out by means of a materially bonded connection rather than a frictional connection. The material connection is preferably effected in this case by welding or soldering, wherein a material corresponding to the heat exchanger head plate 3020 or to the pipes is used as the soldering or welding material. This also has the advantage that thermal stresses in the pipe seats 3024 can be minimized by homogeneous thermal expansion coefficients.

(63) It is also possible in the case of this solution to install pipes in the pipe seats 3024 by force fit, and in addition to this to solder or weld them. Through this type of installation, seal tightness of the heat exchanger can also be ensured, if different materials are used for the pipes and the heat exchanger head plate 3020, since the possibility exists that due to the very high occurring temperatures of over 1,000 C. use of only a press fit can possibly fail under certain circumstances because of different thermal expansion coefficients.

(64) TABLE-US-00001 Reference labels: 201 axial-piston engine 205 housing body 210 combustion chamber 215 shot channel 220 working cylinder 225 exhaust gas channel 227 outlet 230 working piston 235 connecting rod 240 curved track 241 output shaft 242 spacer 250 compressor piston 255 pressure line 257 supply line 260 compressor cylinder 270 heat exchanger 401 axial-piston engine 405 housing body 410 combustion chamber 415 shot channel 420 working cylinder 425 exhaust gas channel 427 outlet 430 working piston 435 connecting rod 440 curved track 441 output shaft 442 spacer 450 compressor piston 455 pressure line 456 ring channel 457 supply line 460 compressor cylinder 470 heat exchanger 480 combustion agent reservoir 481 reservoir line 485 valve 501 axial-piston engine 502 main combustion direction 503 axis of symmetry 504 combustion air supply system 505 housing body 506 ceramic assembly 507 ceramic combustion chamber wall 508 profiled pipe 509 cooling air chamber 510 combustion chamber 511 main nozzle 512 processing nozzle 513 conical chamber 514 cylindrical chamber 515 shot channel 516 first jet direction 517 preburner 518 main burner 519 other jet direction 520 working cylinder 521 process air supply 522 other combustion air supply 523 perforated ring 524 cooling air chamber supply 525 exhaust gas channel 526 combustion space 530 working piston 531 control piston 532 control piston cover 533 control piston curved track 534 spacer 535 connecting rod 536 connecting rod running wheels 537 driving curved track carrier 538 water cooling system 539 shot channel ring 540 curved track 541 output shaft 543 stroke motion 545 inner cooling channels 546 middle cooling channels 547 outer cooling channels 548 combustion chamber floor 550 compressor piston 560 compressor cylinder 592 prechamber temperature sensor 593 exhaust gas temperature sensor 901 axial-piston engine 912 processing nozzle 927 precombustion chamber 928 fuel 929 combustion air 980 fuel processing system 981 fuel heater 982 glow plug 983 mixing pipe 984 flush combustion air supply 985 fuel injection system 986 vaporizer 987 spark plug 988 cooling system 1001 axial-piston engine 1012 processing nozzle 1027 precombustion chamber 1080 fuel processing system 1081 fuel heater 1082 glow plugs 1083 mixing pipe 1084 flush combustion air supply 1086 vaporizer 1087 spark plug 1095 check valve 1096 valve seat 1097 ceramic valve ball 3020 heat exchanger head plate 3021 flange 3022 mounting hole 3023 matrix 3024 pipe seat