Method and system for converting energy from an industrial process

Abstract

The present invention relates to an energy conversion system comprising a thermoreactor (25) for exothermic reaction processes, in particular a regenerative thermoreactor (25), in particular a thermal exhaust air treatment plant (2), having a reaction chamber (25f), and comprising an energy conversion device (1). The energy conversion device (1) comprises a working medium circuit for transporting thermal energy, a working medium heater (3) and a evaporation device (4), arranged downstream of the working medium heater (3), for isenthalpic evaporation. The working medium heater (3) is arranged within the reaction chamber (25f) of the thermoreactor (25).

Description

[0001] Method and system for converting energy from an industrial process

[0002] Description

[0003] Technical area

[0004] The present invention relates to an energy conversion system comprising a thermal reactor for exothermic reaction processes, in particular a regenerative thermal reactor, in particular a thermal exhaust air purification system, preferably a regenerative thermal exhaust air purification system (also known as RTO), with a reaction chamber and an energy conversion device. Furthermore, the invention relates to a method for converting thermal energy from a fluid stream.

[0005] State of the art

[0006] Thermal processes are used in many industrial processes, for example in thermal exhaust air purification, where contaminated process air from an industrial process is heated to a high temperature using a supporting flame in order to oxidize the combustible pollutants. This creates waste heat, which is often simply released into the environment. However, the waste heat generated can be converted into usable energy as a heat source, for example using an Organic Rankine Cycle (ORC) process. An ORC process can be used in particular when the available temperature gradient between the heat source and sink is too low to operate a turbine driven by steam as the working fluid. The working fluid is typically heated by a heat source, evaporated, and then expanded in a heat engine. The working fluids typically used are methane, butane (e.g. n-butane), pentane (e.g.n-pentane), cyclohexane, methylcyclohexane, isopentane, ethanol, ethylbenzene, toluene, silicone oil or refrigerants such as R1233zd(E) are used.

[0007] Description of the invention

[0008] The present invention is based on the object of creating an improved device for converting energy from an industrial plant / industrial process, whereby increased flexibility of use is achieved while simultaneously improving the energy and CO2 balance and avoiding overly complex designs.

[0009] This object is achieved according to the invention with an energy conversion system which comprises a thermoreactor for exothermic reaction processes, in particular a regenerative thermoreactor, in particular a thermal exhaust air purification system, with a reaction chamber and an energy conversion device.The energy conversion device comprises: a working fluid circuit for transporting thermal energy; a working fluid heater for heating a flowing working fluid, wherein the working fluid is fed in the liquid state through an inlet to the working fluid heater and, after flowing through the working fluid heater in the liquid state, leaves the working fluid heater through an outlet; an evaporation device for isenthalpic evaporation arranged downstream of the working fluid heater, having an inlet through which the working fluid in the liquid state is fed from the working fluid heater into the evaporation device; a first outlet through which a portion of the working fluid in the gaseous state is fed out of the evaporation device; and a second outlet through which a portion of the working fluid in the liquid and / or gaseous state is fed out of the evaporation device.

[0010] According to the invention, the working medium heater is arranged within the reaction chamber of the thermoreactor.

[0011] The working fluid preferably circulates in the working fluid circuit. The working fluid circuit is preferably designed or constructed as a closed media circuit. The working fluid is conveyed or guided in particular in lines or pipes separated from the environment of the device and connecting the devices of the device to one another in a fluid-conducting manner, and / or by direct, fluid-conducting connection of the devices and / or direct integration of individual devices as subcomponents of a more complex device. The working fluid heater can thus be easily arranged directly in the reaction chamber of the thermoreactor, e.g. of an exhaust air purification system. The inventors have discovered that it is advantageous for the energy conversion device to realize the heat transfer from the heat source to the working fluid in a liquid state.This ensures a higher heat transfer in the working fluid heater than if the working fluid partially evaporates during heating and remains in a gaseous phase. It is therefore particularly advantageous if the saturation vapor pressure of the working fluid is not exceeded during heating. This advantage can be technically implemented by applying additional pressure to the working fluid. This means that the working fluid is subjected to a higher pressure before entering the working fluid heater, whereby the working fluid is in, or remains in, a liquid state during heating and even after flowing through the working fluid heater.To further develop the inventive approach, the working fluid is guided to an evaporation device after leaving the working fluid heater, where the working fluid is evaporated isenthalpically and, particularly preferably, is converted or passes predominantly into a gas phase. However, it may happen that the working fluid remains partially in the liquid state. The heat transfer from the heat source to the working fluid takes place in the working fluid heater, while the phase transition of the working fluid from the liquid to a / the gas phase takes place or occurs in the evaporation device. The heating of the working fluid, i.e., the absorption of thermal energy from a heat source, and the phase transition are thus advantageously implemented spatially separate from one another.

[0012] In particular, an organic working fluid can be used for this purpose, for example cyclohexane, butane, pentane, benzene, toluene, R134a, R12, R123, R113, n-perfluoropentane. A suitable working fluid is characterized in particular by its thermodynamic properties. Suitable working fluids typically have an overhanging wet vapor region in the temperature-entropy (TS) or enthalpy-entropy (HS) diagram. An overhanging wet vapor region in a TS diagram can be present in particular when the entropy value on the dew line also decreases with decreasing pressure. In a further preferred embodiment of the invention, the dew line of the working fluid in a temperature-entropy (TS) diagram has a decreasing entropy value with decreasing pressure.

[0013] The working fluid circuit can, in particular, refer to a thermodynamic cycle. The working fluid circulating in the working fluid circuit of the device can therefore participate in a thermodynamic cycle.

[0014] The working fluid can be removed from the working fluid heater in a circulating circuit, particularly within the device, and returned to the working fluid heater at the end of a circuit. The working fluid circuit can thus refer, in particular, to a working fluid circulating in a circuit. The working fluid heater can, in particular, be a heat exchanger or heat transfer device. The heat source can, for example, be a hot industrial process gas from a thermal exhaust air purification process. The hot industrial process gas can flow through the working fluid heater and, in the process, release thermal energy, which is transferred to the working fluid via the heat exchanger, thereby heating the working fluid. According to the invention, the working fluid heater is arranged within the reaction chamber of the thermoreactor.In the reaction chamber of the thermoreactor, for example, an exothermic reaction can take place or proceed in at least one reaction chamber or fixed bed. In preferred applications, such as in thermal exhaust air purification systems, contaminated process air can be oxidized to other air components, for example, using a supporting flame or an electric heating device. The working fluid heater can, in particular, be part of a fixed-bed reactor or be coupled to a fixed-bed reactor.

[0015] The pressure of the working fluid can be adjusted, in particular by means of a pressure adjustment device such as a compressor or a pump, in particular increased to a level suitable for the subsequent absorption of thermal energy in the working fluid heater, which is intended or planned or to be carried out, but which maintains the liquid state of the working fluid. The working fluid therefore has a certain pressure (inlet pressure p1) upon entering the working fluid heater, so that it is always or predominantly in a liquid state throughout the entire heating process as it flows through the working fluid heater. The working fluid therefore remains essentially liquid in the working fluid heater. Maximum temperatures of the working fluid on the heating surfaces arranged in the working fluid heater are preferably below 400 °C, and particularly preferably below 350 °C or below 300 °C, respectively.The temperatures at the heating surfaces can also be understood as film temperatures or temperatures at the heat transfer surfaces. The film temperature is preferably below the critical temperature of the working fluid. For example, this is approximately 340 °C for ethylbenzene. The maximum film temperature when used with ethylbenzene as the working fluid is therefore 340 °C. At temperatures below the maximum temperatures, the working fluids used can remain in a liquid state. The maximum temperatures at the heating surfaces preferably correspond to the boiling points of the working fluids used. Maintaining the liquid state even at the heating surfaces within the working fluid heater can, for example, ensure advantageous heat transfer of thermal energy to the working fluid.

[0016] The evaporation device can, in particular, be an expansion device or an expander. It can, in particular, be designed in the form of a so-called "flash tank" or an evaporation vessel. The evaporation device has, in particular, a diffuser or a distributor, wherein the working fluid, after entering the evaporation device, escapes through the diffuser into the interior and expands, i.e., is expanded or the pressure is at least partially reduced. In particular, the expansion process within the evaporation device does not involve complete expansion, but rather partial expansion. The working fluid is preferably expanded to a pressure level that corresponds to a preferred inlet pressure of a downstream heat engine.The expansion of the working fluid in the evaporation device essentially corresponds, in particular, to an isenthalpic pre-expansion of the working fluid, so that the temperatures of the working fluid at the inlet and at the first and second outlets are identical or almost identical. A portion of the working fluid that has passed into the gas phase due to the pressure reduction can leave the evaporation device via the first outlet. For example, the evaporation ratio in the evaporation device can be more than 50%, 60%, or 70%, preferably more than 80%, particularly preferably more than 85% or 90%. The evaporation ratio can be understood, in particular, as the ratio between the mass flow of the gaseous working fluid, which is passed through the first outlet, and the inlet mass flow of the liquid working fluid, i.e., the total inlet mass flow.The evaporation ratio can be understood, in particular, as the ratio between the gaseous and liquid portions of the working medium after the evaporation process has been carried out. A separation device can, in particular, be arranged upstream of the first outlet of the evaporation device or above the diffuser within the evaporation device, whereby fine droplets can be separated at the separation device and collected in the evaporation device by gravity.

[0017] The liquid-phase portion of the working fluid can be removed from the evaporation device via the second outlet and, for example, returned to the inlet of the working fluid heater. This particularly preferably corresponds to the smaller portion of the inlet mass flow, for example, less than 30%, 20%, 15%, or 10% of the inlet mass flow. For this purpose, the working fluid used has particularly advantageous thermophysical properties to achieve such an evaporation ratio. A large portion of the working fluid supplied to the evaporation device can thus be converted into the gas phase, and only a small portion of the working fluid is returned to the working fluid heater.

[0018] Optionally, the portion of the working fluid in the liquid phase can be further expanded, for example, in another chamber of the evaporation device or by means of a nozzle, so that the liquid working fluid transitions into the gas phase and can be discharged from the evaporation device via the second outlet. Further expansion of the remaining working fluid can have the advantage of generating even more gaseous working fluid, which can be advantageously utilized for energy recovery. The pressure of the gaseous working fluid after further expansion can, in particular, be lower than the pressure of the gaseous working fluid discharged from the evaporation device via the first outlet.

[0019] The pre-expansion in the evaporation device can therefore be understood in particular as meaning that the now gaseous working medium is expanded through the first or second outlet downstream of the evaporation device in an optional expansion device such as in a heat engine, for example in a turbine, wherein in particular the enthalpy contained in the working medium is converted into mechanical energy.

[0020] In the context of this disclosure, "A" and "an" are to be read as indefinite articles unless expressly stated otherwise, and thus always as "at least one" or "at least one." Directional terms such as "downstream" or "after" or "upstream" or "before" generally refer to the flow direction of the working fluid, particularly in the working fluid circuit. For the purposes of the invention, the term "isenthalpic" is also intended to encompass a state that is nearly isenthalpic. Isenthalpic evaporation can, in particular, mean evaporation without the external supply of enthalpy or thermal energy during the phase transition.

[0021] In a preferred embodiment of the invention, the energy conversion system comprises a heat engine arranged downstream of the evaporation device of the energy conversion device, which heat engine is driven by at least a portion of the working medium evaporated in the evaporation device, wherein mechanical energy can be extracted from the heat engine.

[0022] The heat engine can, in particular, be a turbine, preferably of radial design but also of axial or hybrid design. Alternatively, the heat engine can also be designed as a piston engine. The heat engine can, in particular, be connected to a generator for power generation, whereby the mechanical energy extracted from the heat engine can be at least partially converted into electrical energy.

[0023] In a further preferred embodiment of the invention, the energy conversion system has a condenser arranged downstream of the evaporation device of the energy conversion device, wherein the working medium changes from a gaseous state to a liquid state by means of the condenser, during which change of state heat is coupled out of the condenser.

[0024] The condenser is particularly preferably arranged downstream of a heat engine, with the gaseous working fluid being feedable to the condenser downstream of the heat engine. In the condenser, the working fluid can be cooled and thereby converted into a liquid phase, whereby usable thermal energy can preferably be extracted, for example, by transferring it to a heat transfer medium by means of a coupled heat exchanger.

[0025] Downstream of the condenser, the working medium condensed therein can be combined with the liquid portion of the working medium escaping from the second outlet of the evaporation device and / or fed to a working medium reservoir and / or directly fed back to the working medium heater.

[0026] Particularly advantageously, a working fluid reservoir can be arranged downstream of the condenser, whereby the condensed working fluid can be collected in the working fluid reservoir. The working fluid reservoir can be designed, in particular, as a commercially available "hotwell tank," with the temperature, water level, and outlet mass flow adjustable by means of appropriate controllable valves.

[0027] In a further preferred embodiment of the invention, the energy conversion system has a recuperator arranged downstream of a heat engine of the energy conversion device for heating the working fluid, which is led to the inlet of the working fluid heater, wherein a part of the thermal energy is extracted from the working fluid downstream of the heat engine and transferred to the working fluid led to the inlet of the working fluid heater.

[0028] Downstream of a heat engine, the gaseous working fluid may still contain usable thermal energy, which can be extracted in a usable manner downstream by means of a recuperator. Particularly preferably, the gaseous working fluid can be guided to the recuperator after the heat engine. The recuperator can in particular be arranged upstream of a condenser, wherein the working fluid cooled in the recuperator can be guided to the condenser. After the working fluid has been converted into a liquid working fluid in the condenser, the liquid working fluid can be reheated by means of the recuperator. A heat transfer can therefore take place by means of the recuperator. The recuperator can therefore, for example, be designed as a cross-flow heat exchanger, wherein on the one hand the gaseous working fluid upstream of the condenser is cooled and on the other hand a liquid working fluid downstream of the condenser is heated.Preferably, the recuperator can also be arranged downstream of a working fluid reservoir. Particularly preferably, the recuperator can serve as a preheater for the working fluid, whereby the recuperator can be arranged upstream of the working fluid heater, before the working fluid is fed to the working fluid heater. This would have the advantage of improving the overall heating effect of the working fluid heater.

[0029] In a further preferred embodiment of the invention, the energy conversion system comprises a storage unit arranged downstream of the working fluid heater of the energy conversion device, into which storage unit a portion of the working fluid is fed through a storage inlet. A portion of the working fluid is stored in the liquid state by means of the storage unit, and a portion of the stored working fluid is fed to the evaporation device through a storage outlet at a later time than the time of feed in the liquid state. The working fluid in the liquid state downstream of the working fluid heater has a higher volume-specific heat capacity than the working fluid in the gaseous state, for example, downstream of the evaporation device.Due to the increased energy density in the liquid state, the working fluid would have the advantage of being able to be constructed in a space-saving manner compared to the gaseous state, for example by storing the working fluid in the gaseous state with a comparatively lower energy density. The arrangement of the storage unit downstream of the working fluid heater also corresponds to a point in the thermodynamic cycle with comparatively high exergy. It is particularly advantageous to arrange the storage unit at this point, whereby at least part of the working fluid can be stored in the liquid state. The inventive approach further develops this advantage by feeding at least part of the stored working fluid, which has a high exergy, through a storage outlet to the evaporation device at a time later than the time of feed-in.The evaporation device can be used to generate the gaseous working fluid, which can then be used to generate electricity in a heat engine. This makes it possible to convert mechanical energy from stored working fluid in the heat engine, for example, at a later time when the waste heat source has a lower heat input.

[0030] In a further preferred embodiment of the invention, the energy conversion device comprises the following: a working medium circuit for transporting thermal energy; a working medium heater for heating a flowing working medium, which is coupled to a waste heat source of an industrial process, wherein the working medium is guided in the liquid state through an inlet to the working medium heater and, after flowing through the working medium heater in the liquid state, leaves the working medium heater through an outlet; an evaporation device arranged downstream of the working medium heater with an inlet through which the working medium in the liquid state is guided from the working medium heater into the evaporation device; a first outlet through which a portion of the working medium in the gaseous state is guided out of the evaporation device; a second outlet,through which a portion of the working fluid is led out of the evaporation device in the liquid and / or gaseous state, a heat engine arranged downstream of the evaporation device, which is driven by at least a portion of the working fluid evaporated in the evaporation device, wherein mechanical energy, in particular for generating electricity, can be extracted from the heat engine, a condenser arranged downstream of the heat engine, wherein the working fluid condenses by means of the condenser in a condensation process, during which condensation process heat can be extracted from the condenser, a compressor arranged downstream of the condenser for increasing the pressure of the working fluid, a return line arranged downstream of the compressor, through which the working fluid can be conveyed to the inlet of the working fluid heater.

[0031] The thermoreactor of the energy conversion system according to the invention can, in particular, be a thermal exhaust air purification system, wherein contaminated process air is heated to a high temperature. In the process, the combustible pollutants oxidize to other air components. The heat released can serve as a heat source for the energy conversion device. The reaction chamber can, in particular, be a combustion chamber of the thermal exhaust air purification system. A flameless regenerative thermal oxidation system "Oxi.X RV" from the applicant could also be conceivable as a reaction chamber. Any chamber suitable for exothermic oxidation processes, in which at least one hot gas flows whose temperature is above the ignition temperature of the working fluid, could also be conceivable as a reaction chamber. This can, in particular, be a dynamic hot gas storage device, which is, for example, the subject of EP 1 953 489 B1.

[0032] In a further preferred embodiment, at least part of the energy required to operate the reaction chamber can be supplied to the reaction chamber in the form of electrical energy, which is generated by means of a generator coupled to the heat engine of the energy conversion device, wherein mechanical energy can be decoupled from the heat engine and coupled into the generator, wherein the mechanical energy decoupled from the heat engine has been converted from thermal energy of the working medium in the heat engine, which thermal energy originates from the thermoreactor.

[0033] The thermoreactor can therefore, in particular, be an electrically operated thermal exhaust air purification system, with electric heating being used in the reaction chamber. Electricity generated by the energy conversion device can be used to heat the system. The energy source comes from the waste heat source in the form of the thermoreactor, which serves as the heat source for the working fluid heater. In particular, this can reduce the amount of electricity required from the power grid to operate the thermal exhaust air purification system.

[0034] The present invention further relates to a method for converting thermal energy of a fluid stream.

[0035] The method comprises the following method steps: feeding a liquid working fluid into a working fluid heater; transferring thermal energy from a waste heat source of an industrial process to the liquid working fluid within the working fluid heater, wherein the working fluid remains in the liquid state while absorbing thermal energy; discharging the liquid working fluid from the working fluid heater; passing the liquid working fluid into an evaporation device for carrying out an evaporation process in which the working fluid is expanded, wherein a portion of the working fluid is discharged from the evaporation device in the gaseous state by means of a first outlet and a further portion of the working fluid is discharged from the evaporation device in the liquid state and / or gaseous state by means of a second outlet.

[0036] The waste heat source is a thermoreactor for exothermic reaction processes with a reaction chamber, in particular a regenerative thermoreactor, in particular a thermal exhaust air purification system. Here, the working fluid heater is arranged within the reaction chamber of the thermoreactor. When the liquid working fluid is fed into a working fluid heater, the working fluid heater is supplied with, in particular, a predominantly liquid working fluid of a first state Z1, characterized, for example, by a temperature T1 and a pressure p1. The absorption of thermal energy in the working fluid heater is preferably an at least predominantly isochoric change of state, for example to a state Z2 with a temperature T2 and a pressure p2.The expansion of the working fluid in the evaporation device preferably corresponds at least substantially to an isenthalpic pre-expansion of the working fluid, so that the expanded gaseous working fluid from the first outlet experiences, for example, a state Z3 with a temperature T2' essentially identical to T2 and a pressure p3, where: p1 < p3 < p2. The working fluid before expansion can, for example, have a gas content of almost 0% and after expansion can, in particular, have a gas content of 70%, preferably 80% or particularly preferably 90%. The pressure ratio p2 / p3 can, for example, be 1.3 to 4, at an inlet pressure between 20 - 50 bar.

[0037] In a further preferred embodiment of the invention, a part of the gaseous working medium is led to a heat engine arranged downstream of the evaporation device, by means of which energy is extracted from the working medium and decoupled from the heat engine as mechanical energy.

[0038] In a further preferred embodiment of the invention, a part of the gaseous working medium is led to a condenser arranged downstream of a heat engine, by means of which the gaseous working medium is cooled and liquefied in a condensation process, during which condensation process thermal energy is extracted.

[0039] In a further preferred embodiment of the invention, the method comprises the following method steps: a portion of the working fluid is temporarily stored in the liquid state downstream of the working fluid heater; a portion of the temporarily stored working fluid is fed in the liquid state to the evaporation device. In a further preferred embodiment of the invention, the method comprises the following method steps: a portion of the working fluid is fed downstream of a heat engine to a recuperator, wherein thermal energy is extracted from the working fluid by means of the recuperator; using the thermal energy extracted from the working fluid, a portion of the working fluid fed to the working fluid heater is reheated in a method step taking place downstream of the recuperator.

[0040] In a further preferred embodiment of the invention, the working medium in the evaporation device has a larger gaseous than liquid content after the evaporation process has been carried out. The gaseous content can in particular be more than 50%, 60%, or 70%, preferably more than 80%, particularly preferably more than 85% or 90%.

[0041] In a further preferred embodiment of the invention, the method comprises the following method steps: feeding a liquid working fluid into a working fluid heater; transferring thermal energy from a waste heat source of an industrial process to the liquid working fluid within the working fluid heater, wherein the working fluid remains in a liquid state while absorbing thermal energy; removing the liquid working fluid from the working fluid heater;Passing the liquid working fluid into an evaporation device in which the working fluid is expanded, wherein a first larger part of the working fluid in the gaseous state and a second smaller part of the working fluid in the liquid state and / or gaseous state, which gaseous state of the working fluid has a lower pressure than the first larger part of the working fluid, are led out of the evaporation device, a part of the gaseous working fluid is led to a heat engine arranged downstream of the evaporation device, by means of which energy is extracted from the working fluid and decoupled from the heat engine as mechanical energy, a part of the working fluid is led downstream of a heat engine to a recuperator, wherein heat energy is extracted from the working fluid by means of the recuperator;by means of the thermal energy extracted from the working fluid, part of the working fluid fed to the working fluid heater is reheated; downstream of the heat engine, part of the gaseous working fluid is condensed, whereby thermal energy is extracted, the pressure of the working fluid is increased, and the working fluid is fed back to the working fluid heater.

[0042] Examples of implementation

[0043] The invention is explained in more detail below using several exemplary embodiments, without distinguishing between the different claim categories. Furthermore, it is clarified that the proposed solutions according to the invention can be applied to various different industrial processes. An energy conversion device coupled to a thermal exhaust air purification system is presented below as an example.

[0044] Character list

[0045] The drawings show:

[0046] Fig. 1 is a schematic representation of an energy conversion system according to the invention;

[0047] Fig. 1a is a schematic representation of a method according to the invention, preferably for implementation in a device according to Fig. 1;

[0048] Fig. 2 is a schematic representation of a device according to the invention according to Fig. 1 with a storage tank and a hotwell tank;

[0049] Fig. 2a is a schematic representation of a method according to the invention, preferably for implementation in a device according to Fig. 2;

[0050] Fig. 3 is a schematic representation of a device according to the invention with two turbines;

[0051] Fig. 3a is a schematic representation of a method according to the invention, preferably for implementation in a device according to Fig. 3;

[0052] Fig. 4 is a schematic representation of a process in a Ts diagram;

[0053] Fig. 4a shows a further representation of a method according to the invention in a Ts diagram; Fig. 5 shows a schematic representation of a method in a pH diagram;

[0054] Fig. 5a shows a further schematic representation of an inventive

[0055] process in a pH diagram;

[0056] Fig. 6 is a schematic representation of a detail of another energy conversion system according to the invention;

[0057] Fig. 7 is a schematic representation of a detail of yet another energy conversion system according to the invention;

[0058] Fig. 8 is a schematic representation of a detail of yet another energy conversion system according to the invention;

[0059] Fig. 9 is a schematic representation of a detail of yet another energy conversion system according to the invention;

[0060] Fig. 10 is a schematic representation of a detail of yet another energy conversion system according to the invention;

[0061] Fig. 11 section AA according to Fig. 10;

[0062] Fig. 12 is a schematic representation of a detail of yet another energy conversion system according to the invention;

[0063] Fig. 13 Section AA according to Fig. 12;

[0064] Fig. 14 is a schematic representation of a detail of yet another energy conversion system according to the invention and

[0065] Fig. 15 section AA according to Fig. 14;

[0066] Fig. 16 Section AA according to Fig. 14 with an alternative design of the

[0067] Working part heater.

[0068] Preferred embodiment of the invention

[0069] Fig. 1 schematically shows an embodiment of an energy conversion system according to the invention for converting energy from a thermoreactor in the form of an exhaust air purification system 2. In the exhaust air purification system 2, process air contaminated with oxidizable / combustible substances is oxidized, optionally with the aid of an electric heater, and a hot exhaust gas is generated. Such exhaust air purification systems 2 are known, for example, from the previously unpublished application PCT / EP2023 / 054493. The hot exhaust gas is fed to the working fluid heater 3, where it serves as a heat source for heating the working fluid. The hot exhaust gas flows through a heat exchanger in the working fluid heater 3, wherein, for example, liquid cyclohexane or ethylbenzene flowing through the heat exchanger as the working fluid is passed over the heating surfaces and heated.The working fluid heater 3 is arranged within a reaction chamber of the thermoreactor designed as an exhaust air purification system 2. The working fluid heater 3 can be designed as a heat exchanger and arranged in a fixed-bed reactor located in the reaction chamber. Due to the particularly good heat transfer properties of the liquid working fluid, film temperatures of, for example, 340 °C are not exceeded on the heating surfaces of the heat exchanger. The liquid working fluid remains in a liquid state throughout the entire heating process in the working fluid heater 3. The bold arrows in Figures 1 to 4a indicate, by way of example, the at least predominantly liquid state of the working fluid, while the thin arrows indicate the at least predominantly gaseous state of the working fluid.

[0070] At the end of the heating process, the working fluid is heated in the working fluid heater 3 to a temperature of 320 °C and has a pressure of 30 bar.

[0071] In a particularly preferred embodiment, the working fluid heater 3 is arranged in an exhaust air purification system 2, for example, according to WO 2023161313 A1, namely in its reaction chamber. This can include arranging the working fluid heater 3 in its heat storage mass and its fixed bed. The working fluid heater 3 is preferably designed as a pressure-resistant heat exchange device, in particular a corresponding piping arranged in the system 2 for the liquid working fluid pre-pressurized to a suitable pressure.

[0072] The liquid working fluid then leaves the working fluid heater 3 via an outlet 3b and is led to an inlet 4a in an evaporation device 4. The liquid working fluid first flows through a diffuser 4d within the evaporation device 4, where the working fluid is isenthalpically expanded to a pressure of 15 bar. Approximately 80% of the working fluid that was or is fed to the evaporation device 4 evaporates. The evaporated, now gaseous working fluid is further passed through a separation device 4e, where fine liquid droplets of working fluid are separated as a disperse phase with the aid of the separation device 4e. The gaseous working fluid then leaves the evaporation device 4 via a first outlet 4b. At this point, the working fluid has a temperature of 230 °C and a pressure of 15 bar.Approximately 20% of the working fluid which is not evaporated in the evaporation device 4 is returned to the working fluid heater 3 via a second outlet 4c.

[0073] The gaseous working fluid is fed downstream of the evaporation device 4 to a turbine 5, preferably of radial design, in which the working fluid is expanded to a lower enthalpy level. Upon entry, the working fluid has a temperature of approximately 230°C and a pressure of approximately 15 bar. In the turbine 5, the working fluid is expanded to a pressure of approximately 0.5 bar and a temperature of approximately 180°C. Thermal energy is converted into mechanical energy and extracted from the turbine 5. A power generator 6 is connected to the turbine 5, with power being generated from the rotational movement of the generator 6.

[0074] Downstream of the turbine 5, a condenser 7 is arranged in the working fluid circuit, in which the gaseous working fluid is cooled and liquefied. The condenser 5 preferably has a heat exchanger through which a cooling medium, such as water, flows. Heat from the condensation process of the working fluid is extracted from the condenser with the help of the cooling medium. The working fluid flows through the condenser, with the working fluid being separated or deposited as liquid condensate on the cooling surfaces of the condenser. The condensation process in the condenser takes place almost isobarically, so that the working fluid is cooled from approximately 180 °C at the inlet to approximately 50 °C at the outlet at an approximately constant 0.5 bar.

[0075] The working fluid is then fed to a first compressor 81, where the pressure is increased to approximately 15 bar. Downstream of the first compressor 81, liquid working fluid from the evaporator 4 is combined with the working fluid from the condenser 7 and fed to a second compressor 82, where the pressure is increased to approximately 30 bar. Finally, the working fluid is fed back to an inlet 3a of the working fluid heater 3.

[0076] Fig. 1 a shows a schematic representation of a method according to the invention, preferably for implementation in a device according to Fig. 1. The following method steps are accordingly carried out:

[0077] S3: Waste heat from an electrical heater of an exhaust air purification system 2 is transferred to the liquid working fluid within the working fluid heater 3. In this example, the working fluid is supplied to the working fluid heater 3 at a pressure of 30 bar. In the working fluid heater, the temperature of the working fluid increases, preferably isobarically, from approximately 70 °C to 320 °C. The working fluid remains in a liquid state throughout the entire heating process. After the heating process, the liquid working fluid is discharged from the working fluid heater 3 with reference symbol A.

[0078] S4: The liquid working fluid is then passed to an evaporation device 4. In the evaporation device 4, the working fluid is expanded, i.e., the pressure of the working fluid in the evaporation device 4 is reduced isenthalpically from 30 bar to approximately 15 bar. A large portion of the working fluid, in this example approximately 80%, evaporates in the evaporation device 4 during the expansion process. The evaporated, gaseous working fluid is led from the evaporation device 4 to process step S5 via a first outlet 4b. A small portion of the working fluid, referenced A, in this example approximately 20%, remains in the liquid state and is led from the evaporation device 4 to process step S82 via a second outlet 4c.

[0079] S5: At least a portion of the thermal energy of the gaseous working fluid B is converted into another energy in this step. This portion of the thermal energy is preferably converted into mechanical and / or electrical energy. The gaseous working fluid B is expanded, for example, using a turbine, whereby the pressure in this example is reduced from 15 bar to 0.5 bar and the temperature is reduced from 230 °C to approximately 180 °C. In this process step, thermal energy is extracted from the working fluid by means of the turbine and at least partially converted into mechanical energy. The mechanical energy is coupled out of the first turbine 5 via a shaft. The shaft is preferably coupled to a generator 6 for power generation.

[0080] S7: Downstream of turbine 5, the gaseous working fluid B is fed into a condensation process. During this process, the working fluid B is cooled and condenses as condensate. The temperature drops from 180 °C to approximately 50 °C. During the condensation process, the released heat energy is transferred to a cooling circuit coupled to the condenser. This extracts heat energy from the condensation process.

[0081] S81: Downstream of the condenser, the now liquefied working fluid A is passed to a first compression process S81 and conditioned for combining with another liquid working fluid stream A from the second outlet 4c of the evaporation device 4. The pressure level to be set here preferably corresponds to the pressure of the liquid working fluid at the second outlet 4c of the evaporation device 4. This is because the two streams are combined downstream of the first compression process S81. The pressure increases from 0.5 to 15 bar. The working fluid is then combined with the working fluid from the second outlet 4c of the evaporation device 4 and passed to process step S82.

[0082] S82: The now combined working fluid streams are then fed to a second compression process S82. During this process, the working fluid is conditioned for the heating process in process step S3, in particular, its pressure is increased to a corresponding pressure level so that the working fluid remains in a liquid state throughout the entire heating process. During the second compression process S82 of this example, the pressure increases from 15 bar back to the inlet pressure of the working fluid heater 3 at 30 bar. Fig. 2 shows a schematic representation of a second embodiment of a device according to the invention according to Fig. 1 with a reservoir and a hotwell tank;

[0083] In contrast to Fig. 1, a portion of the liquid working fluid is discharged from the working fluid heater 3 through the outlet 3b and guided to a storage inlet 21a, which is arranged downstream of the working fluid heater 3. A first valve 12 is intended to adjust the flow of the working fluid to the storage 21 as well as the flow to the evaporation device 4. In the storage 21, the working fluid is stored in the liquid state, preferably at the same temperature and pressure as the working fluid has when leaving the working fluid heater 3. A portion of the stored working fluid can be guided to the evaporation device through a storage outlet 14 at a later time than the time of feed. A second valve 14 is intended for this purpose, which adjusts or makes adjustable the flow through the storage outlet 14.For example, the waste heat output of the exhaust air purification system 2 may fluctuate, resulting in more or less waste heat being transferred to the working fluid in the working fluid heater 3 at certain times. Such fluctuations can be smoothed or temporally decoupled using the storage unit 3 by storing a portion of the heated working fluid in the storage unit 3 at times of higher heat transfer in the working fluid heater 3, instead of converting the excess heat energy directly and instantly in the turbine. At times of lower heat transfer, stored working fluid can be fed to the evaporation device 4 in order to convert the stored, previously excess heat energy at a later time in the turbine 5.The energy converted in the turbine 5 can thus be advantageously smoothed, in particular at times of higher heat transfer, whereby the mechanical energy otherwise converted in excess in the turbine 5 would not have been required.

[0084] Also in deviation from Fig. 1, a so-called hotwell tank 9 is arranged downstream of the condenser 7. The hotwell tank 9 can be understood as a condensate reservoir, wherein condensed working fluid can be collected or stored downstream of the condenser 7. The hotwell tank 9 can preferably compensate for the portion of the working fluid that is stored, in particular temporarily, in the accumulator 21, wherein additional, condensed working fluid is fed from the hotwell tank 9 to the working fluid heater 3 or to the first compressor 81. The mass flow of the circulated working fluid can thus be compensated by means of the hotwell tank 9 and the accumulator 21 in that the amount of working fluid fed into the accumulator 21 is compensated with the same amount of working fluid that is additionally available in the hotwell tank 9 and is fed out of the hotwell tank 9 or supplied to the working fluid circuit.For this purpose, a third valve 11 is provided, which determines or makes determinable the flow of the working medium which is discharged from the hotwell tank 9.

[0085] Fig. 2a shows a schematic representation of a further embodiment of a method according to the invention, preferably for implementation in a device according to Fig. 2.

[0086] In contrast to Fig. 1 a, after process step S3, a portion of the liquid working fluid A is fed to a process step S21, in which at least a portion of the working fluid A is temporarily stored. A remainder of the working fluid A not stored in process step S21 is preferably fed directly to process step S4, in which the working fluid A is at least partially evaporated. The working fluid A temporarily stored in process step S21 can be fed to process step S4 at least partially offset or delayed from the time of feed-in or temporary storage.

[0087] Also in deviation from the method according to Fig. 1a, after method step S7 the liquid working fluid A is led to a method step S9. In method step S9, a portion of the liquid working fluid A is stored by means of a condensate reservoir, which in this example is designed in the form of a hotwell tank 9. In particular, if the working fluid A is stored in method step S21, whereby a certain amount of working fluid A is withdrawn from the circulating working fluid circuit after method step S3, additional liquid working fluid A can be made available in method step S9 and fed into the circulating working fluid circuit. The additionally fed-in working fluid A originates at least in part from the working fluid A which was previously led from method step S7 to method step S9.

[0088] If temporarily stored liquid working fluid A is returned to the working fluid circuit in process step S21, this additional amount of working fluid can be stored in process step S9 using the condensate reservoir 9 and thus removed from the circulating working fluid circuit after process step S7. The amount of working fluid circulating in the working fluid circuit can thus be balanced, preferably kept constant, using process step S9.

[0089] Fig. 3 shows a schematic representation of a further embodiment of a device according to the invention with two turbines and a recuperator.

[0090] In contrast to Fig. 2, the liquid working fluid discharged via the second outlet 4c is guided to an expansion nozzle, in particular a Laval nozzle 4f, wherein the working fluid is expanded from an original pressure of 15 bar at the second outlet 4c to 8 bar in a nearly isenthalpic manner. The working fluid, which is liquid upstream of the Laval nozzle 4f, transforms into the gaseous state or gas phase in or after the Laval nozzle 4f.

[0091] Optionally, a mixer for mixing the partial flows of the gaseous working medium can be arranged downstream of the Laval nozzle 4f and the turbine 5c as well as upstream of the turbine 5c.

[0092] 1 and 2. In the exemplary embodiment according to Fig. 3, two turbines 5b, 5c are provided. In this example, the turbine 5b is preferably of radial design and the turbine 5c of axial design. Alternatively, the turbines 5b, 5c can also be designed as stages of a multi-stage turbine, in particular a multi-stage axial turbine. The turbines 5b, 5c are operatively coupled to one another, in particular mechanically connected to one another. Thus, as shown in Fig. 3, a shaft of the turbine 5b can be connected to a shaft of the turbine 5c by means of a gear 5d or can be connected or coupled to this. In particular, at least one coupling device (not shown here) in the gear 5d or additionally can design or implement an operative connection between the turbines 5b, 5c in a controllable or regulatable, in particular releasable, manner.

[0093] After the transition to the gas phase, the working fluid expanded to 8 bar in the Laval nozzle 4f is combined with the working fluid downstream of the turbine 5b and led to the turbine 5c, in which the now combined working fluid is further expanded to 0.5 bar, whereby mechanical energy is or can be extracted from the turbine 5c.

[0094] Downstream of the turbine 5c, the gaseous working fluid is fed to a recuperator 10, where, on the one hand, thermal energy is extracted from the gaseous working fluid and, on the other hand, the thermal energy extracted from the gaseous working fluid is fed back to the liquid working fluid fed to the working fluid heater 3. The still gaseous working fluid, cooled in the recuperator, is then fed to the condenser 7, where the working fluid is further cooled to 50 °C and preferably completely liquefied.

[0095] The working fluid liquefied in the condenser 7 is now fed downstream to a hotwell tank 9. This serves in particular to keep the amount of working fluid circulating in the working fluid circuit of the device 1 almost constant.

[0096] Downstream of the hotwell tank 9, the working fluid is compressed to 30 bar by a compressor 83 and fed to the recuperator 10, in which the working fluid is preheated to 150°C by the intersecting working fluid flow, as described above. Due to the preheating by the recuperator 10, the working fluid can be heated more efficiently in the working fluid heater 3. Fig. 3 also shows a power line 6a through which at least part of the energy required in the exhaust air purification system 2 can be supplied electrically, wherein the electrical energy is generated by the generator 6. The energy supplied to the exhaust air purification system 2 can, for example, generate heat output, which is fluidly coupled into the working fluid heater 3 and is at least partially available as thermal energy in the working fluid for conversion in the turbines 5b and 5c.As described above, the electrical energy was generated from the extracted mechanical energy that was previously converted in the turbines 5b and 5c.

[0097] Fig. 3a shows a schematic representation of a further embodiment of a method according to the invention, preferably for implementation in a device according to Fig. 3.

[0098] In contrast to Fig. 2a, a small portion of the liquid working fluid A is fed to a process step S4f after process step S4, in which it is converted into the gaseous state, in particular by further expansion. The working fluid converted into the gas phase in process step 4 is fed as gaseous working fluid B to a process step S5b, in which at least part of the thermal energy of the gaseous working fluid B is converted into another energy. This part of the thermal energy is preferably converted into mechanical and / or electrical energy. Preferably, the gaseous working fluid B after process step S5b has a substantially identical pressure to the gaseous working fluid B after process step S4f. Particularly preferably, the temperatures of the partial streams after S5b and S4f are also substantially identical.Downstream of process step S4f, the two partial streams of the gaseous working medium B are combined and led to process step S5c.

[0099] Optionally, a process step takes place downstream of process steps S5b and S4f, wherein the partial streams from S5b and S4f are mixed before entering process step S5c. Preferably, the gaseous working fluid B, now combined from two partial streams, is expanded in the turbine 5b, and mechanical energy is extracted in the process. In a process step S5c, the gaseous working fluid B is further expanded, with further mechanical energy being extracted. After process step S5c, the working fluid is led to a process step S10a, wherein thermal energy is extracted from the gaseous working fluid B. The working fluid B cools down in the process. The dashed line C in Fig. 3a represents a flow of thermal energy between process steps S10a and S10b, wherein the energy extracted from the gaseous working fluid B in process step S10a is essentially transferred to the liquid working fluid A in process step S10b.

[0100] After process step S10a, the gaseous working medium B is guided or passed to a process step S7.

[0101] In contrast to Fig. 2a, the liquid working fluid A is fed to a process step S83. In process step S83, a compression process takes place, whereby the liquid working fluid A is already compressed to the pressure level required in process step S3; in this embodiment, this is 30 bar. After the working fluid A has been compressed in process step S83, the working fluid A is preheated in process step S10b, whereby the thermal energy used for preheating originates from process step S10a.

[0102] After process step S10b, the liquid working fluid A is returned to process step S3. In addition to Fig. 2a, process step S2 is shown in Fig. 3a, in which a reaction chamber of the exhaust air purification system is electrically heated for the oxidation process, whereby waste heat is generated from the oxidation process. The dashed line E represents a flow of thermal energy between process steps S2 and S3. The dashed line D in Fig. 3a represents a flow of electrical energy between process steps S5b and S5c, in which electrical energy is generated, and process step S2, in which the electrical energy generated in process steps S5b and S5c is used for the electrical heating in the reaction chamber of the exhaust air purification system.

[0103] Fig. 4 shows a schematic representation of a process without an evaporation device in a temperature-entropy (Ts) diagram. Z1a exemplifies the thermodynamic state of the working fluid before entering the working fluid heater 3.

[0104] The following procedural steps are also carried out:

[0105] Z1a to Z2a(i): The working fluid is heated isobarically, causing its temperature to rise. At the same time, the entropy of the working fluid increases, in particular, the entropy of the working fluid increases until the boiling point of a corresponding isobar of the working fluid is reached.

[0106] Z2a(i) to Z2a(ii): In the working fluid heater, an evaporation process then takes place from Z2a(i) to Z2a(ii), with further heat energy being added to the working fluid. The entropy of the working fluid continues to increase, while the temperature remains constant during the evaporation process.

[0107] Z2a(ii) to Z3a: The evaporated working fluid is then expanded in a turbine 5.

[0108] Z3a to Z4a: The essentially still gaseous working fluid is subsequently deheated in the recuperator 10 or the condenser 7, whereby the temperature of the working fluid decreases. In the process, the temperature and entropy of the still gaseous working fluid decrease.

[0109] Z4a to Z5a: At the latest in condenser 7, the working fluid is cooled to or below the dew point, whereby the working fluid is liquefied in a condensation process.

[0110] Z5a to ZOa: Optionally - as shown here - the liquefied working fluid is also subcooled in condenser 7, in particular to ensure complete liquefaction.

[0111] ZOa to Z1 a: The liquid working fluid is compressed and led to the inlet of the working fluid heater 3a.

[0112] Fig. 4a shows a schematic representation of a method according to the invention with

[0113] Evaporation device in a temperature-entropy (Ts) diagram. Z1b exemplifies, as in Fig. 4, the thermodynamic state of the working fluid before entering the working fluid heater 3. State Z2b exemplifies the thermodynamic state of the working fluid upon entering the evaporation device 4. Compared to Fig. 4, state Z2b has a higher pressure than state Z2a(i). State Z2b(i), for example, has a gas fraction of 80% and a liquid fraction of 20%.

[0114] The following procedural steps are also carried out:

[0115] Z1 b to Z2b: The working fluid is heated isobarically in the working fluid heater 3.

[0116] Z2b to Z2b(i): The working fluid is expanded isenthalpically or almost isentropically by means of a throttle, whereby the working fluid has a gaseous portion x1 and a liquid portion x2 after the expansion process.

[0117] Z2b(i) to Z2b(iii): The gaseous working medium x1 is led from the first outlet 4b of the evaporation device 4 to an inlet of the turbine 5.

[0118] Z2b(i) to Z2b(ii): The liquid working fluid x2 is discharged from the second outlet 4c of the evaporation device 4.

[0119] Z2b(ii) to Z1 b: The liquid working fluid x2 is returned to the inlet 3a of the working fluid heater 3.

[0120] Z2b(iii) to Z3b: The gaseous working fluid x1 is expanded in the turbine 5.

[0121] Z3b to Z4b: The working fluid x1 is deheated in the condenser 7, whereby the temperature of the working fluid decreases.

[0122] Z4b to Z5b: The working fluid is further liquefied in a condensation process. Z5b to ZOb: The now liquefied working fluid is subcooled in condenser 7.

[0123] ZOb to Z1 b: The working fluid is compressed and led to the inlet of the working fluid heater 3a.

[0124] Fig. 5 shows a schematic representation of a process without an evaporation device in a pressure-enthalpy (ph) diagram. Z1 aa shows the thermodynamic state of the working fluid before it enters the working fluid heater 3. Isobaric heat energy is then supplied to the working fluid in the working fluid heater 3. Z3aa denotes the state of the working fluid as it enters the turbine 5, before the working fluid expands and part of the heat energy is converted into mechanical energy. The phase transition from liquid to gaseous takes place in the process shown in Fig. 5 within the working fluid heater 3, i.e. like the line that represents the state progression between Z1 aa and Z3aa. The working fluid is therefore heated in the working fluid heater 3, whereby the temperature rises. Further heating takes place in the working fluid heater 3 and the working fluid essentially changes from the liquid to the gas phase.During expansion in turbine 5, the pressure and enthalpy of the working fluid decrease, reaching state Z4aa. Subsequently, the working fluid is liquefied in a condensation process and then compressed to state Z1aa.

[0125] Fig. 5a shows a schematic representation of a method according to the invention with an evaporation device in a pressure-enthalpy (ph) diagram. Z1 bb shows the thermodynamic state of the working fluid before entering the working fluid heater 3. Subsequently, isobaric heat is supplied to the working fluid in the working fluid heater 3, and the working fluid assumes state Z2bb. Compared to Fig. 5, the pressure in state Z1 bb is higher than in Z1 aa. The pressure level of state Z1 bb is preferably selected or adjusted such that the working fluid remains essentially in the liquid phase, preferably completely in the liquid phase, even after passing through the working fluid heater 3. Z2bb characterizes the state of the working fluid after passing through the working fluid heater 3, i.e., upon entering the evaporation device 4.In the evaporator 4, an isenthalpic expansion of the working fluid takes place, reaching state Z3bb at the outlet. During expansion in the turbine 5, the pressure and enthalpy of the working fluid decrease, reaching state Z4bb. Subsequently, the working fluid is liquefied in a condensation process and then compressed back to state Z1bb.

[0126] Fig. 6 shows a schematic representation of an inventive arrangement of the working medium heater 3 in a reaction chamber of a thermoreactor 25. The thermoreactor 25 is depicted as a fixed-bed reactor of the exhaust air purification system 2. Pollutant-containing exhaust air is guided through an inlet 25a into a fixed-bed reaction chamber 25f, in which an electrically operated heating device 25c is arranged. The heating device 25c is designed such that it can be operated using the electrical energy generated by the generator 6. The heating device 25c can also be designed to be operated using electrical energy from the power grid. After flowing through the fixed-bed reaction chamber 25f, the exhaust air is discharged from the thermoreactor 25 via an outlet 25b. In the fixed-bed reaction chamber, reaction processes can preferably proceed autothermally, whereby the pollutant-containing exhaust air can be oxidized into harmless components.In such autothermal operation, the at least one exothermic oxidation process to which the contaminated process air is subjected or exposed generates at least, preferably more, thermal energy than is at least required for the continuous operation of the thermoreactor 25 of the exhaust air purification system 2 or the continuous running of the oxidation process in the thermoreactor 25 of the exhaust air purification system 2. In autothermal operation of the exhaust air purification system 2, in particular, continued electrical heating or other measures supplying additional thermal energy to a reaction chamber of the exhaust air purification system 2 can be dispensed with, or these can be interrupted or suspended. The working medium heater 3 is fluidly coupled to the fixed-bed reaction chamber by means of a pipe system that is arranged at least partially within the fixed bed of the reaction chamber.An organic working medium can be passed through the pipe system to absorb thermal energy. As an advantageous safety feature, a pressure sensor 25d, 25e is arranged on the inlet and outlet sides of the pipe system of the working medium heater 3, wherein the inlet and outlet pressure of the working medium to the fixed bed reaction chamber can be measured by means of the respective pressure sensor 25d, 25e. In the event of a leak in the pipe system, the measured pressure values ​​can deviate from one another. In particular, the measured pressure from the pressure sensor 25e can be lower than the measured pressure of the pressure sensor 25d. In the event of a deviation in the pressure values, a safety device (not shown), for example a valve system or a compressed air system with inert gas, can evacuate the pipe system and thus avoid a possible ignition or fire hazard. As an alternative to the pressure sensors 25d, 25e, it is also possible toIt is also conceivable to provide or arrange a differential pressure sensor between an inlet of the working medium heater 3 and its outlet in order to be able to determine a pressure difference analogously to the use of two pressure sensors 25d, 25e and preferably to activate, actuate or trigger a safety device in the event of deviations or exceedance of a limit value.

[0127] Fig. 7 shows a schematic representation of an inventive arrangement of the working medium heater 3 in a reaction chamber of another thermoreactor 25. The representation in Fig. 7 represents a detail of the energy conversion system according to the invention, since of the device components of the energy conversion device 1, only the working medium heater 3 is shown. The thermoreactor 25 is a regenerative thermoreactor 25, more precisely a system for regenerative thermal oxidation (RTO) with multiple chambers, for example, with two chambers. An RTO is a special design of a thermal exhaust air purification system. Although the embodiments each show systems with two chambers, it goes without saying that the invention is not limited to this and rather also encompasses embodiments with more than two chambers, for example, with three or more chambers.To avoid duplication, only the differences to the arrangement shown in Fig. 6 are explained below.

[0128] The reaction chamber of the thermoreactor 25 is provided in this case by a treatment housing 250 having two chambers, each of which contains a permeable heat storage body 252, 253, separated by an intermediate wall. The heat storage bodies 252, 253 can comprise a thermal storage material (e.g., a ceramic), in particular in the form of a solid, in particular in the form of a honeycomb body.

[0129] The treatment housing 250 further comprises a combustion chamber 255, on which a burner 251 is arranged, via which heat can be supplied to the combustion chamber 255 by burning a fuel. The burner 251 is particularly important during start-up of the system in order to bring the heat storage bodies 252, 253 to their operating temperature. Depending on the concentration and chemical-physical properties of the pollutants in the raw gas stream, however, autothermal operation of the system is also possible and advisable, which means, in particular, that no (or only a reduced) heat supply via the burner 251 is required.

[0130] A raw gas stream F is fed to the treatment housing 250, which is optionally directed via the raw gas valves 20, 40 through one of the heat storage bodies 252, 253 to preheat the raw gas stream F. The raw gas stream F is then exposed to an elevated temperature, for example, between 750°C and 1000°C, in the region of the combustion chamber 255, whereby (organic) pollutants are post-combusted and converted into less harmful combustion products - for example, CO2 and water. The post-combusted raw gas stream flows downstream of the combustion chamber 255 through the respective other heat storage body 252, 253 as a clean gas stream E to the outlet, with heat being transferred to the respective heat storage body 252, 253 and stored therein. Clean gas valves 30, 50 can be used to determine which of the chambers is connected to a suction side of the blower 254. As soon as the heat storage body 252,523, which was previously flowed through by the raw gas flow F, is thermally discharged, iethat its temperature has fallen below a predetermined lower limit, the switching position of the raw gas valves 20, 40 and the clean gas valves 30, 50 is changed so that the raw gas flow F then flows in via the other of the heat storage bodies 252, 253 and the post-combusted raw gas flow flows out analogously via the other of the heat storage bodies 252, 253. The regenerative thermoreactor 25 is operated in particular cyclically, which means that the raw gas valves 20, 40 and the clean gas valves 30, 50 are alternately switched in order to alternately charge and discharge the heat storage bodies 252, 253. A change in the flow regime results in the flow direction of the combustion chamber 255, which is indicated by an arrow, being reversed.

[0131] In the present case, the working fluid heater 3 is embedded in the heat storage bodies 252, 253, with particular consideration given to an arrangement at an end close to the combustion chamber 255 to ensure that as much heat as possible can be supplied to the working fluid heater 3. A single working fluid heater 3 can be provided, extending through both heat storage bodies 252, 253. In other words, the working fluid heater 3 can be a common working fluid heater 3, designed to absorb heat from both chambers.

[0132] In the embodiment of Fig. 8, which essentially corresponds to the embodiment according to Fig. 7, which is why only the differences will be discussed, each of the heat storage bodies 252, 253 arranged in the chambers is assigned its own working fluid heater 3. The energy conversion device 1 can in particular comprise means that allow heat to be selectively extracted from one or the other working fluid heater 3. In particular, it can be provided that heat is extracted via the working fluid heater 3 that is assigned to the chamber through which the post-combusted raw gas stream is currently flowing.

[0133] In the embodiment of Fig. 9, the working fluid heater 3 is arranged directly in the combustion chamber 255, which has the advantage that more heat can be extracted, since the heat is provided at a higher temperature level and heat transfer resistance is eliminated. Otherwise, the embodiment of Fig. 9 corresponds in functionality to the embodiments shown in Figs. 7 and 8.

[0134] Fig. 10 shows yet another design of a regenerative thermoreactor 25, in which a cylindrical or hollow-cylindrical heat storage body with a plurality of heat storage segments 256a to 256h (see also Fig. 11) is used. The heat storage body comprising the heat storage segments 256a to 256h is in turn arranged within the treatment chamber 250. Adjacent to the treatment chamber 250 is a flow distribution element in the form of a rotary valve 200, via which, on the one hand, the raw gas flow F can be directed over a specific heat storage segment 256a to 256h and, on the other hand, the post-burned raw gas flow can be directed downstream of the combustion chamber 255 over another of the heat storage segments 256a to 256h.As soon as a specific pairing of heat storage segments 256a to 256h to be thermally charged and discharged has been brought into a predetermined thermal equilibrium, the rotary valve 200 is rotated further by a predetermined angular amount, so that the heat storage segment 256a to 256h, which was previously arranged on the outlet side, is then arranged on the inlet side, and another heat storage segment 256a to 256h, which is thermally uncharged, is arranged on the outlet side. The heat storage body itself can remain stationary. The rotary valve 200 can be operated in a cyclical manner, which means that during a switching operation it is rotated further by an angular amount that corresponds in particular to an angular extent of a heat storage segment 256a to 256h. Alternatively, the rotary valve 200 can also be operated continuously, which means that it is permanently rotated.

[0135] The advantage of the design with rotary valve 200 lies in particular in a greatly reduced complexity, in particular by minimizing the number of moving components. Similar to the embodiment of Fig. 9, the working medium heater 3 is again arranged within the combustion chamber 255. In Fig. 11, a section AA shows the heat storage body in a plan view, wherein the segmentation into the plurality of heat storage segments 256a to 256h is clearly visible. The heat storage segments 256a to 256h can be separate storage bodies that are joined together to form the heat storage body. Alternatively, the heat storage segments 256a to 256h can also be regions of a uniform heat storage body, each extending over a specific angular range.

[0136] Figs. 12 and 13 show a modification of the embodiment of Fig. 11, which corresponds to Fig. 11 except for the positioning of the working medium heater 3, which is why only the differences will be discussed again. A pair of corresponding heat storage segments 256a to 256h is each assigned its own working medium heater 3, which is embedded in the respective heat storage segment 256a to 256h. The integration of the working medium heaters 3 into the energy conversion device 1 can be carried out as described for Fig. 8. In section AA in Fig. 13, which shows the heat storage body in a plan view, only the working medium heaters 3 assigned to the heat storage segments 256a and 256e are shown. However, further heat storage segments 256a to 256h may also comprise working fluid heaters 3; in particular, each of the heat storage segments 256a to 256h may comprise its own working fluid heater 3. In Figs. 14 and 15,15 shows a further modification of the embodiment of FIG. 11, which corresponds to FIG. 11 except for the positioning of the working medium heater 3, which is why only the differences will be discussed again. The working medium heater 3 comprises a spiral heat exchanger, which in turn is embedded in the heat storage body at an end near the combustion chamber 255. The spiral heat exchanger can, for example, extend in a plane that runs in the normal direction with respect to a rotational axis of the rotary valve 200. The section AA shown in FIG. 15 clearly shows the structure of the spiral heat exchanger of the working medium heater 3, which extends in several turns over the circumference of the heat storage body and is embedded in each of the heat storage segments 256a to 256h.The advantage of this embodiment is that the integration into the energy conversion device 1 of the energy conversion system according to the invention is uncomplicated, since only one working medium heater 3 is present and therefore no means for switching between several working medium heaters are required.

[0137] Fig. 16 shows an alternative version of the embodiment according to Figs. 14 and 15, which corresponds to Figs. 14 and 15 except for the design of the working medium heater 3, which is why only the differences are discussed here. The working medium heater 3 is constructed as a multi-pass heat exchanger, wherein each pass is designed as a substantially complete circular ring or a circular ring segment. The circular rings of the passes are preferably embedded concentrically in the heat storage body. In the embodiment according to Fig. 16, each circular ring or circular ring segment is flow-conductingly connected to a heat exchanger supply line and a heat exchanger discharge line in such a way that the working medium can be introduced into the circular rings or circular ring segments via the heat exchanger supply line and discharged from them via the heat exchanger discharge line. However, it can also be advantageous if the circular rings orCircular ring segments are connected in groups or even individually via separate heat exchanger supply and heat exchanger discharge lines in the working medium heater 3.

Claims

Patent claims 1. Energy conversion system comprising a thermoreactor (25) for exothermic reaction processes, in particular a regenerative thermoreactor (25), in particular a thermal exhaust air purification system, preferably a regenerative-thermal exhaust air purification system (2), with a reaction chamber (25f) and an energy conversion device (1), the energy conversion device (1) comprising: - a working fluid circuit for transporting thermal energy; - a working fluid heater (3) for heating a flowing working fluid, wherein the working fluid is fed in the liquid state through an inlet to the working fluid heater (3a) and, after flowing through the working fluid heater in the liquid state, leaves the working fluid heater (3) through an outlet (3b), - an evaporation device (4) for isenthalpic evaporation arranged downstream of the working medium heater (3) with o an inlet (4a) through which the working medium in the liquid state is led from the working medium heater (3) into the evaporation device (4), o a first outlet (4b) through which a part of the working medium in the gaseous state is led out of the evaporation device (4), o a second outlet (4c) through which a part of the working medium in the liquid and / or gaseous state is led out of the evaporation device (4), wherein the working medium heater (3) is arranged within the reaction chamber (25f) of the thermoreactor (25).

2. Energy conversion system according to claim 1 with a heat engine (5) arranged downstream of the evaporation device (4) of the energy conversion device (1), which is driven by at least a part of the working medium evaporated in the evaporation device (4) wherein mechanical energy, in particular for generating electricity, is or can be extracted from the heat engine (5).

3. Energy conversion system according to one of the preceding claims, with a condenser (7) arranged downstream of the evaporation device (4) of the energy conversion device (1), wherein the working medium changes from a gaseous state to a liquid state by means of the condenser (7), during which change of state heat is coupled out of the condenser (7).

4. Energy conversion system according to one of the preceding claims, with a recuperator (10) arranged downstream of the heat engine (5) of the energy conversion device (1) for heating the working medium, which is led to the inlet of the working medium heater (3a), wherein a part of the thermal energy is extracted from the working medium downstream of the heat engine (5) and transferred to the working medium led to the inlet of the working medium heater (3a).

5. Energy conversion system according to one of the preceding claims, with a storage device (21) arranged downstream of the working medium heater (3) of the energy conversion device (1), into which storage device a part of the working medium is fed through a storage inlet (21a), wherein by means of the storage device (21) a part of the working medium is stored in the liquid state, wherein a part of the stored working medium is led to the evaporation device (4) at a later time than at the time of feeding in the liquid state through a storage outlet (21b).

6. Energy conversion system according to one of the preceding claims, the energy conversion device (1) comprising: - a heat engine (5) arranged downstream of the evaporation device (4) which is driven by at least part of the working medium evaporated in the evaporation device (4), wherein mechanical energy, in particular for generating electricity, can be extracted from the heat engine (5), - a condenser (7) arranged downstream of the heat engine (5), wherein the working medium condenses out by means of the condenser (7) in a condensation process, in which condensation process heat can be extracted from the condenser (7), - a compressor (81, 82) arranged downstream of the condenser (7) for increasing the pressure of the working medium, - a return line (83) arranged downstream of the compressor (81, 82), through which the working medium can be conveyed to the inlet of the working medium heater (3a).

7. Energy conversion system according to one of the preceding claims, wherein at least part of the energy required to operate the reaction chamber (25f) can be supplied to the reaction chamber (25f) in the form of electrical energy, which is generated by means of a generator (6) coupled to the heat engine (5) of the energy conversion device (1), wherein mechanical energy can be decoupled from the heat engine (5) and coupled into the generator (6), wherein the mechanical energy decoupled from the heat engine (5) has been converted from thermal energy of the working medium in the heat engine (5), which thermal energy originates from the thermoreactor (25).

8. A method for converting thermal energy of a fluid stream, the method comprising the following steps: Feeding a liquid working medium into a working medium heater (3); Transferring thermal energy from a waste heat source (2) of an industrial process to the liquid working fluid within the working fluid heater (3), wherein the working fluid remains in the liquid state when absorbing thermal energy; Discharging the liquid working medium from the working medium heater (3); passing the liquid working medium into an evaporation device (4) for carrying out an evaporation process in which the working medium is expanded isenthalpically, wherein a part of the working medium in the gaseous state by means of a first outlet (4b) and a further part of the working medium in the liquid state and / or gaseous state by means of a second outlet (4c) from the evaporation device (4), wherein the waste heat source (2) is a thermoreactor (25) for exothermic reaction processes with a reaction chamber (25f), in particular a regenerative thermoreactor (25), in particular a thermal exhaust air purification system (2), and wherein the working medium heater (3) is arranged within the reaction chamber (25f) of the thermoreactor (25).

9. Method according to claim 8, in which a part of the gaseous working medium is led to a heat engine (5) arranged downstream of the evaporation device (4), by means of which energy is extracted from the working medium and decoupled from the heat engine (5) as mechanical energy.

10. The method according to claim 8 or 9, wherein a portion of the gaseous working medium is fed to a condenser (7) arranged downstream of the heat engine (5), wherein the gaseous working medium is cooled and liquefied in a condensation process, during which condensation process thermal energy is extracted.

11. The method according to any one of claims 8 to 10, wherein the method comprises the following steps: a portion of the working fluid is temporarily stored in the liquid state downstream of the working fluid heater (3); a portion of the temporarily stored working fluid is fed in the liquid state to the evaporation device (4).

12. Method according to one of claims 8 to 11, wherein the method comprises the following method steps: A portion of the working fluid is led downstream of a heat engine (5) to a recuperator (10), wherein thermal energy is extracted from the working fluid by means of the recuperator (10); a portion of the working fluid led to the working fluid heater (3) is reheated by means of the thermal energy extracted from the working fluid.

13. Method according to one of claims 8 to 12, wherein the working medium in the evaporation device (4) has a larger gaseous than liquid portion after carrying out the evaporation process.

14. The method according to any one of claims 8 to 13, wherein the method comprises the following method steps: a first larger portion of the working fluid in the gaseous state and a second smaller portion of the working fluid in the liquid state and / or gaseous state, which gaseous state of the working fluid has a lower pressure than the pressure of the first larger portion of the working fluid, are led from the evaporation device (4); a portion of the gaseous working fluid is led to a heat engine (5) arranged downstream of the evaporation device (4), by means of which heat engine (5) energy is extracted from the working fluid and decoupled from the heat engine (5) as mechanical energy; a portion of the working fluid is led downstream of the heat engine (5) to a recuperator (10), wherein heat energy is extracted from the working fluid by means of the recuperator (10);by means of the thermal energy extracted from the working medium, part of the working medium fed to the working medium heater (3) is reheated, downstream of the heat engine (5) part of the gaseous working medium is condensed, whereby thermal energy is extracted, the pressure of the working medium is increased, the working medium is fed back to the working medium heater (3);

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