Device for generating electrical and / or mechanical energy using an ORC system, and method for operating a working medium circuit of an ORC system

Abstract

The invention relates to a device (100) for generating electrical and / or mechanical energy using an ORC system, the device comprising a working medium circuit (10) with a working medium evaporator (11), an expansion machine (E) and a condenser (12). At least one bypass valve (17) is arranged in the working medium circuit (10) and can be switched in order to bypass the expansion machine (E) through an expansion machine bypass line (19) and thereby at least temporarily transfer an increased proportion of the thermal energy received in the working medium evaporator (11) from a working medium of the working medium circuit (10) to a cooling medium of a cooling medium flow of the condenser (12). The invention also relates to a method for operating a working medium circuit (10) of an ORC system.

Description

[0001] July 18, 2025 u - 1 - Device for generating electrical and / or mechanical energy with an ORC system, and method for operating a working fluid circuit of an ORC system. Description: The invention relates to a device for generating electrical and / or mechanical energy with an ORC system, which has a working fluid circuit for a working fluid, wherein the working fluid circuit comprises a working fluid evaporator and an expansion machine operated with working fluid vapor from the working fluid evaporator. Furthermore, the invention relates to a method for operating a working fluid circuit of an ORC system. An ORC system (ORC = Organic Rankine Cycle) is understood to be a system that generates mechanical and / or electrical energy from heat using a thermodynamic cycle.In an ORC system, there is a working fluid cycle that does not use water as the working fluid, but typically uses organic media such as butane, toluene, silicone oil, or ammonia, which have a lower evaporation temperature compared to water. The working fluid in an ORC system is usually pumped in its liquid state from a working fluid reservoir to a working fluid evaporator by means of a feed pump. There, the liquid working fluid is converted into working fluid vapor by the addition of heat, which then enters an expansion engine, which can be, for example, a steam turbine. In the expansion engine, the working fluid is expanded to a lower pressure while generating mechanical energy and is then condensed in a condenser, from which the liquid working fluid returns to the working fluid reservoir.From this, the working fluid is then fed back into the working fluid evaporator in the working fluid cycle, where it is reheated and evaporated again. It should be noted that media with a higher evaporation temperature than water can also be used as working fluids in an ORC system. ORC systems can be used advantageously for generating electrical and / or mechanical energy from heat, especially when the available temperature difference between a heat source and a heat sink is too low to operate a heat engine, such as a turbine, using water as the working fluid. ORC systems can be operated not only with heat from combustion plants. The heat required to operate an ORC system can also be obtained from other sources or from solar power plants. Furthermore, ORC systems can also be operated with the waste heat from internal combustion engines (e.g.,...These engines are operated by reciprocating engines or gas turbines. When utilizing waste heat from internal combustion engines, it is possible to use heat from the flue gas as well as heat from a coolant circuit designed to cool the engine. The heat dissipated from the working fluid circuit in the condenser is also frequently used for energy recovery by coupling a cooling medium used to cool the condenser into a useful heat circuit, such as a heating circuit. This heating circuit could, for example, be a district heating network, with the temperature level typically between 60°C and 95°C. Based on common mechanical and electrical efficiencies of the working fluid circuit, approximately 75 to 90% of the heat absorbed from the heat source in the working fluid evaporator is recovered at the condenser.To maximize the utilization of the heat supplied by the heat source for heating purposes during periods of increased heating demand, such as in cold winter months, ORC systems often incorporate heating circuit heat exchangers. These heat exchangers transfer heat directly from the heat source to the heating circuit, enabling the transfer of nearly 100% of the heat supplied by the heat source to the heating circuit. Such heating circuit heat exchangers can, for example, be designed as exhaust gas heat exchangers, extracting heat directly from the exhaust gas of a combined heat and power (CHP) engine. During periods of increased heating demand, the ORC system can be switched off, resulting in little to no heat being transferred from the heat source to the working fluid circuit.However, the complexity and maintenance intensity of the system are disadvantages. Furthermore, the additional heating circuit heat exchanger also considerably increases the installation space requirements and system costs, especially since an exhaust gas heat exchanger is a comparatively expensive component. The object of the invention is therefore to provide a device for generating electrical and / or mechanical energy with an ORC system, which at least temporarily allows an increased amount of heat to be dissipated from the condenser, which can then be used, for example, for heating purposes, in a useful heat circuit. This object is achieved by a device for generating electrical and / or mechanical energy according to claim 1 and a method for operating a working fluid circuit of an ORC system according to claim 14. Advantageous embodiments and further developments of the invention are specified in the dependent claims.A first aspect of the present invention relates to a device for generating electrical and / or mechanical energy using an ORC system. The ORC system comprises a working fluid circuit for a working fluid, which includes a working fluid evaporator, an expansion machine operable with working fluid vapor from the working fluid evaporator, and a condenser. A source medium flow passes through the working fluid evaporator on a primary side to transfer thermal energy contained in the source medium flow to the working fluid and thereby at least partially evaporate the working fluid. A cooling medium flow passes through the condenser on a secondary side to transfer thermal energy contained in the working fluid at least partially to a cooling medium contained in the cooling medium flow and thereby at least partially condense the working fluid.According to the invention, at least one bypass valve is arranged in the working fluid circuit, which can be switched to bypass the expansion machine via an expansion machine bypass line, thereby transferring at least a temporarily increased proportion of the heat energy absorbed in the working fluid evaporator from the working fluid to the cooling medium of the cooling medium flow. The "increased proportion" refers to a comparison of an operating state with active bypass (expansion machine is not or only partially flowed through by working fluid and generates no or reduced mechanical and / or electrical energy) with an operating state with inactive bypass (expansion machine is flowed through and generates mechanical and / or electrical energy): With active bypass, more heat energy is transferred to the cooling medium in the condenser than with inactive bypass.In other words, with active bypassing, heat is transferred via the ORC system's working fluid circuit from the working fluid evaporator, into which heat is coupled from the source fluid stream, to the condenser, from which heat is coupled out into the cooling fluid stream. Since the expansion machine is bypassed by the expansion machine bypass line, no enthalpy is extracted from the working fluid between the working fluid evaporator and the condenser, and a large portion of the heat absorbed in the working fluid evaporator is available in the condenser for release to the cooling fluid stream.The operating mode of the working fluid circuit with active bypass can therefore also be described as "heat transfer operation": In this mode, a maximum proportion of the heat provided by the source medium flow is "passed through" to the cooling medium flow via the condenser without converting the heat in the expansion machine, at least partially, into mechanical and / or electrical energy. The device can be switched to the "heat transfer operation" mode by switching the bypass valve, whereby the bypass line is filled with working fluid and the expansion machine is bypassed. It has been calculated that, via the bypass of the expansion machine according to the invention, approximately 98% of the heat absorbed from the source medium flow in the working fluid evaporator can be transferred to the cooling medium flow via the condenser in "heat transfer operation".Advantageously, the device according to the invention therefore allows, particularly during periods of increased heat energy demand, for more heat to be extracted from the condenser. This functionality is implemented in the device according to the invention in a virtually space-neutral and extremely cost-effective manner, since the only additional components required are the expansion machine bypass line and a bypass valve. It is particularly noteworthy that no expensive additional heat exchanger is required. Generally speaking, the source medium flow represents the heat source from which the thermodynamic cycle carried out in the working fluid circuit is fed. The source medium flow can comprise a fluid, in particular a gaseous fluid, especially an exhaust gas stream from an industrial process and / or an internal combustion engine.The exhaust gas stream can, for example, be a flue gas stream from an internal combustion engine of a combined heat and power plant, for instance comprising a piston engine or a gas turbine. The working fluid evaporator can, in particular, be arranged in an exhaust gas stream of the internal combustion engine of the combined heat and power plant. However, in some embodiments, the source medium stream can also comprise a liquid fluid, in particular water or oil, or a mixture of water or oil with another fluid. The cooling medium stream flowing through the condenser on its secondary side can comprise a fluid, in particular a liquid fluid, especially water or a mixture of water with another fluid. In principle, however, cooling medium streams comprising a gaseous fluid, for example air or another, in particular non-toxic, gas, are also conceivable. Preferably, the cooling medium stream can be part of a useful heat circuit.The system is coupled into a useful heat circuit. This useful heat circuit can, for example, be a heating circuit. This advantageously ensures that the heat extracted from the working fluid in the condenser and at least partially transferred to the cooling medium of the cooling medium flow is not simply released unproductively into the environment, but can be used energetically in a downstream process. The working fluid can, in particular, be a so-called dry medium, meaning that the Ts diagram of the working fluid exhibits a positive slope of the saturated steam curve. The working fluid can, in particular, be methylcyclohexane, pentane, butane, or trans-1-chloro-3,3,3-trifluoropropene (R1233zde). The expansion machine can comprise a turbine, in particular a steam turbine, or a positive displacement machine.The condenser and / or the working fluid evaporator can each include at least one heat exchanger, in particular at least one plate heat exchanger. According to a preferred embodiment, at least one throttling device, in particular comprising a throttle orifice, is arranged in the expansion machine bypass line. Other possible throttling devices include at least one Venturi nozzle, a throttle valve, in particular a ball valve, a throttle flap, and / or a capillary. The throttling device expands the working fluid as it passes through the expansion machine bypass line, in particular without extracting enthalpy. By selecting a throttling device with the largest possible flow cross-section, the pressure at which the working fluid evaporates in the working fluid evaporator can be minimized, thereby maximizing the amount of heat absorbed from the source medium flow in the working fluid evaporator.Furthermore, by using a throttling device with the largest possible flow cross-section, the energy requirement of a working fluid pump, particularly a feed pump, provided in the working fluid circuit can be reduced. According to an advantageous embodiment, the throttling device can be interchangeably arranged in the expansion machine bypass line. This is particularly advantageous for selectively using throttling devices with different hydraulic properties, for example, different cross-sectional areas and / or shapes of flow openings, in the expansion machine bypass line. This allows the throttling effect or the intended expansion of the working fluid to be adjusted quickly and with minimal effort.For example, the expansion machine bypass line can be segmented into at least two sections, with a throttle holder arranged between the two sections. This holder connects the two sections and has a receiving space for a throttle element. In some embodiments, the throttle holder comprises a flange connection, with a first flange being assigned to a first section of the expansion machine bypass line and a second flange to a second section. The throttle element, particularly in the form of an orifice plate, can be received in the flange connection, especially clamped between the two flanges. Alternatively or additionally, the throttle element can be adjustable. Adjustable means, in particular, that the cross-sectional area and / or shape of a passage opening of the throttle element can be changed.An adjustable throttle element can be connected, in particular, to an actuating element that allows adjustment while installed. In other words, the throttle element can be an adjustable throttle, for example, a slot throttle or needle throttle. In some embodiments, the expansion machine bypass line can branch off upstream of the expansion machine; in particular, the bypass valve can be located upstream of the expansion machine. Preferably, the expansion machine bypass line can branch off downstream of the working fluid evaporator, i.e., in particular, viewed in the flow direction, between the working fluid evaporator and the expansion machine. A branch upstream of the expansion machine is advantageous to prevent working fluid vapors from condensing in the expansion machine, which could damage it, especially during restart.Furthermore, an upstream branch of the expansion machine reduces unwanted heat loss to the environment and / or the thermal mass of the expansion machine. According to another embodiment, the device can include a recuperator through which working fluid vapor from the expansion machine flows on a primary side and liquid working fluid flows on a secondary side before the liquid working fluid is fed to the working fluid evaporator. The recuperator increases the efficiency of the ORC system when the expansion machine bypass is inactive, i.e., during "normal operation," by transferring residual heat from the working fluid vapor to the liquid working fluid fed to the working fluid evaporator.In a further embodiment, at least one additional bypass valve can be arranged in the working fluid circuit, which can be switched to bypass the recuperator via a recuperator bypass line. In this case, in "heat transfer operation" mode, the recuperator can be bypassed in addition to the expansion machine. By bypassing the recuperator, the liquid working fluid is not preheated before being fed to the working fluid evaporator. This results in a larger temperature gradient, allowing an increased amount of heat to be coupled from the source fluid flow into the working fluid evaporator. In other words, bypassing the recuperator allows a greater amount of heat to be transported from the working fluid evaporator to the condenser. Furthermore, bypassing the recuperator makes it possible to increase the temperature level available at the condenser, for example, up to 200°C.In some designs, the recuperator bypass line can branch off upstream of the recuperator. In particular, the additional bypass valve can be located upstream of the recuperator. The recuperator bypass line can be configured to bypass the recuperator on the primary and / or secondary sides. In other words, the recuperator bypass line can be configured on the steam or liquid side. An arrangement of the recuperator bypass line on the primary side, i.e., especially on the steam side, has the advantage that unwanted heat loss to the environment and / or the thermal mass of the recuperator can be minimized. An arrangement of the recuperator bypass line on the secondary side, i.e.,Particularly on the liquid side, this has the advantage of being a particularly simple and cost-effective solution, since in this case no special requirements are placed on the thermal and / or pressure resistance of the components of the recuperator bypass line and / or the further bypass valve. According to a further embodiment, the device can have at least one source heat exchanger, which is arranged downstream of the working fluid evaporator on a source heat exchanger primary side, allowing the source medium flow to pass through it, and is configured to extract further thermal energy from the source medium flow. By using an additional heat exchanger, a larger overall temperature gradient of the source medium flow can be achieved, i.e., the available thermal energy is used more efficiently.The source heat exchanger can transfer the additional heat extracted from the source medium flow, in particular to a useful heat circuit designed as a heating circuit. This can be, in particular, the same useful heat circuit, especially a heating circuit, to which the condenser also supplies the heat extracted from it. The heat transfer from the source heat exchanger to the useful heat circuit can optionally occur directly or indirectly, i.e., via an intermediate circuit. In some embodiments, the source heat exchanger can be permeated on a secondary side by a heat transfer medium flow to transfer heat from the source medium flow to the heat transfer medium flow, in particular where the heat transfer medium flow is part of a useful heat circuit, especially a heating circuit.The heat transfer medium flow can be thermally coupled to the cooling medium flow, which also flows through the condenser. In some designs, the heat transfer medium flow can be identical to the cooling medium flow. Alternatively or additionally, the device can include a heat pump, wherein the source heat exchanger is permeable to a heat pump working fluid on a secondary side to transfer heat from the source medium flow to the heat pump working fluid. In other words, the source heat exchanger can act as a working fluid evaporator for the heat pump. By combining it with a heat pump, the source medium flow can be cooled to a significantly lower temperature level, thus further increasing the amount of heat transferred to the useful heat circuit, particularly for heating purposes.It is particularly possible that the heat pump is operated, at least partially, with electrical and / or mechanical energy generated by the expansion machine of the ORC system. For this purpose, at least one electrical connection line can be provided that electrically couples the heat pump to a generator driven by the expansion machine of the ORC system. The heat pump can be any type of heat pump that appears suitable to a person skilled in the art in the context of the present invention, in particular a high-temperature heat pump. The working fluid of the heat pump can be, for example, carbon dioxide (CO2) or ammonia (NH3). According to a further embodiment, the device can include a feed pump for conveying liquid working fluid into the working fluid evaporator. The feed pump is designed to circulate the working fluid through the working fluid circuit.In particular, the feed pump can be arranged downstream of the condenser, especially upstream of the recuperator. The feed pump is specifically designed to increase the pressure of the working fluid and compress it to the operating pressure of the working fluid evaporator. Any working fluid conveying device that appears suitable to a person skilled in the art in the art within the context of the present invention can be considered as the feed pump, provided it is suitable for both the desired pressure increase and the desired working fluid volume flow rate. For example, the feed pump can be a radially or semi-axially flowing, particularly variable-speed, centrifugal pump, or a piston pump. The feed pump can include a drive motor, for example, an electric motor.In a further embodiment, the device can include a working fluid reservoir arranged downstream of the condenser and designed to receive working fluid condensed in the condenser. The working fluid reservoir can also be referred to as a "hotwell." The working fluid reservoir serves as an intermediate storage tank for liquid working fluid before it is (re)introduced into the thermodynamic cycle carried out in the working fluid circuit. In this case, the feed pump can be arranged, in particular, downstream of the working fluid reservoir. Alternatively or additionally, a suction side of the feed pump can communicate fluidically with a reservoir for liquid working fluid formed in the working fluid reservoir. Finally, according to a preferred embodiment, at least one throttling device, in particular comprising an orifice plate, can be arranged in the expansion machine bypass line.Furthermore, the expansion machine bypass line can branch off upstream of the expansion machine, and the bypass valve can be located upstream of the expansion machine. The device also includes a recuperator, through which working fluid vapor from the expansion machine flows on a primary side and liquid working fluid flows on a secondary side before the liquid working fluid is fed to the working fluid evaporator. At least one further bypass valve is also arranged in the working fluid circuit, which can be switched to bypass the recuperator via a recuperator bypass line.By bypassing the recuperator and the expansion machine, an even higher amount of heat can be coupled from the source medium flow into the working fluid evaporator in "heat transfer operation" mode. Subsequently, a correspondingly higher amount of heat can be extracted in the condenser and made available, for example, for heating purposes. Branching off the expansion machine bypass line upstream of the expansion machine is advantageous both from an energy perspective and for reasons of gentle operation (protecting the expansion machine from condensate).A second aspect of the present invention relates to a method for operating a working fluid circuit of an ORC system, in which liquid working fluid is evaporated from a source medium stream in a working fluid evaporator, absorbing heat, and can be supplied as working fluid vapor to an expansion engine, in which the working fluid can be expanded, and in which working fluid vapor is condensed in a condenser, releasing heat to a cooling medium of a cooling medium stream. The expansion engine is bypassed, switchable by a bypass valve, by an expansion engine bypass line in order to transfer at least temporarily an increased proportion of the heat energy absorbed in the working fluid evaporator from the working fluid to the cooling medium of the cooling medium stream.According to a preferred embodiment of the method, working fluid vapor from the expansion machine can be routed through a recuperator primary side, wherein liquid working fluid is routed through a recuperator secondary side of the recuperator before the liquid working fluid is fed to the working fluid evaporator. The recuperator is bypassed, switchable by a further bypass valve, by a recuperator bypass line in order to minimize heat transfer between the working fluid vapor on the recuperator primary side and the liquid working fluid on the recuperator secondary side. According to a further embodiment, the source medium flow, after passing through the working fluid evaporator, can be routed to a source heat exchanger primary side of a source heat exchanger, in which further heat is extracted from the source medium flow.By using an additional heat exchanger, a larger overall temperature gradient of the source medium flow can be achieved, allowing the thermal energy provided by the source medium flow to be used even more efficiently. The source heat exchanger can be traversed on a secondary side by a heat transfer medium flow to transfer heat from the source medium flow to the heat transfer medium flow, particularly where the heat transfer medium flow is part of a useful heat circuit, especially a heating circuit. The heat transfer medium flow can be thermally coupled to the cooling medium flow, which also flows through the condenser. In some embodiments, the heat transfer medium flow can be identical to the cooling medium flow.According to a preferred embodiment, the source heat exchanger can be supplied with a working fluid from a heat pump on a secondary side to transfer heat from the source fluid flow to the working fluid of the heat pump. The heat pump can be driven, at least partially, by electrical and / or mechanical energy generated by the expansion machine of the ORC system. All features, combinations of features, and their specific advantages disclosed with respect to the device according to the first aspect of the invention are transferable to the method according to the second aspect of the invention, and vice versa. Advantageous embodiments of the invention are illustrated in the drawings and described below. Figure 1 shows a system diagram of a device for generating electrical and / or mechanical energy with an ORC system according to the prior art; Figure 2 shows...2 a system diagram of a further device for generating electrical and / or mechanical energy with an ORC system according to the prior art; Fig. 3 a system diagram of a device according to the invention for generating electrical and / or mechanical energy with an ORC system according to a first embodiment; Fig. 4 a system diagram of a device according to the invention for generating electrical and / or mechanical energy with an ORC system according to a second embodiment; Fig. 5 a system diagram of a device according to the invention for generating electrical and / or mechanical energy with an ORC system according to a third embodiment; Fig. 6 a system diagram of a device according to the invention for generating electrical and / or mechanical energy with an ORC system according to a fourth embodiment; Fig.Fig. 7 is a system diagram of a device according to the invention for generating electrical and / or mechanical energy with an ORC system according to a fifth embodiment; Fig. 8 is a system diagram of a device according to the invention for generating electrical and / or mechanical energy with an ORC system according to a sixth embodiment; and Fig. 9 is a system diagram of a device according to the invention for generating electrical and / or mechanical energy with an ORC system according to a seventh embodiment. The diagram in Fig.The prior art device 100 for generating electrical and / or mechanical energy comprises an ORC system with a working fluid circuit 10 for a working fluid, in which a working fluid evaporator 11 for evaporating the working fluid, an expansion machine E, in particular in the form of a steam turbine, and a condenser 12 are arranged. The condenser 12 serves to condense working fluid vapor, in particular saturated working fluid steam, to liquid working fluid. The working fluid can in particular be a so-called dry medium, which means that the Ts diagram of the working fluid has a positive slope of the saturated steam curve. The working fluid can in particular be methylcyclohexane, pentane, butane, or trans-1-chloro-3,3,3-trifluoropropene (R1233zde).Alternatively, the working fluid can be ethylbenzene. However, it is also possible to use butane, toluene, silicone oil, or ammonia as the working fluid in the working fluid circuit. To generate electrical energy, the expansion machine E is coupled to an electric generator G, which in turn can be electrically coupled to a power grid N. The thermodynamic cycle carried out in the working fluid circuit 10 begins with the feed pump 15, which compresses liquid working fluid to the operating pressure of the working fluid evaporator 11. A pressure side of the feed pump 15 is connected to a working fluid inlet of a recuperator secondary side of a recuperator 16. The function of the recuperator 16 will be explained later. After passing through the recuperator 16, the working fluid leaves the recuperator 16 at a working fluid outlet of the recuperator secondary side.As the working fluid vapor passes through the expansion machine E, it expands and enters the recuperator 16 via a working fluid inlet. In the recuperator 16, heat is transferred from the working fluid vapor on the recuperator primary side to the liquid working fluid on the recuperator secondary side. This preheats the liquid working fluid before it flows into the working fluid evaporator 11, increasing the mechanical and / or electrical efficiency of the device 100. After the recuperator 16, the working fluid, still at least partially in the form of working fluid vapor, flows from a working fluid outlet of the recuperator primary side into the condenser 12.The working fluid evaporator 11 has a primary side through which a source medium flows, serving as a heat source for the thermodynamic cycle carried out in the working fluid circuit 10. The primary side of the working fluid evaporator has a source medium inlet and a source medium outlet 111. On the secondary side of the working fluid evaporator 11, the working fluid flows, receiving heat from the source medium flow to evaporate it. Liquid working fluid from the feed pump 15 or the recuperator 16 is fed to the inlet of the secondary side of the working fluid evaporator 11. Working fluid evaporated in the working fluid evaporator 11 is conveyed through the outlet of the secondary side of the working fluid evaporator to the expansion machine E.The source medium flow can enter the working fluid evaporator 11 at the source medium inlet of the primary side of the working fluid evaporator, for example, at a temperature TQ_V_in of 500 °C and at an outlet temperature T. Q_V_ausThe working fluid vapor exits the working fluid evaporator 11 at the source medium outlet 111 on the primary side of the working fluid evaporator at a temperature of 200 °C. The source medium stream comprises, in particular, a gaseous fluid, especially an exhaust gas stream from an industrial process and / or an internal combustion engine. As it passes through the expansion machine E, the working fluid vapor is expanded and then directed into the condenser 12. Upon entering the condenser, the working fluid vapor may, for example, have a temperature of 90 °C. Heat is extracted from the working fluid vapor flowing on the primary side of the condenser, leading to at least partial condensation of the working fluid. A cooling medium stream flows on the secondary side of the condenser, absorbing the heat from the working fluid. The cooling medium stream is fed into the secondary side of the condenser at a cooling medium inlet and discharged at a cooling medium outlet.The cooling medium flow can be part of a useful heat circuit, in particular a heating circuit, for example a district heating network or a building heating system. The cooling medium can be supplied at 60 °C (useful heat circuit return) at the cooling medium inlet of the condenser secondary side. This corresponds to the inlet temperature T. KM_K_ein of the cooling medium into the condenser 12. The cooling medium can enter the condenser 12 at the cooling medium outlet of the condenser secondary side with an output temperature T. KM_K_ausfrom, for example, 80 °C. This corresponds to the temperature of a useful heat circuit supply. Based on common mechanical and electrical efficiencies of the working fluid circuit, approximately 75 to 90% of the heat absorbed from the heat source in the working fluid evaporator is recovered at the condenser. The working fluid condensed on the primary side 122 of the condenser is then fed in liquid form to a suction side of the feed pump 15, so that the cycle can begin again. Figure 2 shows another device 100 for generating electrical and / or mechanical energy according to the prior art. Since this largely corresponds to the device 100 according to the first embodiment, only the differences will be discussed.In order to utilize a maximum proportion of the heat supplied by the source medium flow for heating purposes when the heat dissipated at the condenser 12 is used in a heating circuit during periods of increased heating energy demand, for example in cold winter months, the device includes a source heat exchanger 14 to which source medium exiting from the source medium outlet 111 of the working fluid evaporator 11 is supplied. The source medium flow to the source heat exchanger 14 can, for example, be at a temperature T. Q_WT_eina temperature of 200 °C is supplied. Neglecting heat losses, TQ_WT_in can essentially correspond to TQ_V_out. In the source heat exchanger 14, further thermal energy is extracted from the source medium flow, so that the source medium flow can leave the source heat exchanger 14 at a source medium outlet 141, for example, at a temperature TQ_WT_out of 70 °C. The source medium flow flows on a primary side of the source heat exchanger 14. Fluidically separated from this, the source heat exchanger 14 comprises a secondary side through which a heat transfer medium flows to transfer heat from the source medium flow to the heat transfer medium flow. The heat transfer medium flow can be part of a useful heat circuit, in particular a heating circuit.In particular, the heat transfer medium flow through the secondary side of the source heat exchanger 14 can couple heat into the same useful heat circuit to which the condenser 12 also supplies thermal energy. In other words, the secondary side of the source heat exchanger 14 can be supplied with the same cooling medium flow that also flows through the secondary side of the condenser 12. The cooling medium of the cooling medium flow can be supplied at 60 °C (useful heat circuit return) at the cooling medium inlet of the source heat exchanger's secondary side. This corresponds to the inlet temperature TKM_WT_in of the cooling medium entering the source heat exchanger 14. The cooling medium can exit the source heat exchanger 14 at the cooling medium outlet of the source heat exchanger's secondary side with an outlet temperature TKM_WT_out of, for example, 80 °C. This corresponds to the temperature of a useful heat circuit supply.The additional source heat exchanger 14 makes it possible to transfer a significantly higher proportion of the heat energy provided by the source medium flow to a useful heat circuit, in particular a heating circuit, but is disadvantageous with regard to complexity, maintenance intensity, installation space requirements, and system costs. The device according to the invention, shown in a first embodiment in Fig. 3, takes a different approach to at least temporarily increasing the amount of heat transferable to the cooling medium of the cooling medium flow, in particular to a heating circuit. Since the device 100 according to the invention is largely similar to the prior art device 100 shown in Fig. 1, only the differences will be discussed here, and otherwise reference will be made to the description of Fig. 1.According to the invention, at least one bypass valve 17 is arranged in the working fluid circuit 10 of the ORC system. This bypass valve can be switched to bypass the expansion machine E via an expansion machine bypass line 19. This makes it possible, at least temporarily, to transfer an increased proportion of the heat energy absorbed in the working fluid evaporator 11 from the working fluid to the cooling medium of the cooling medium flow without the need for complex additional components, in particular without an additional expensive heat exchanger. Since the expansion machine E is bypassed by the expansion machine bypass line 19, no enthalpy is extracted from the working fluid between the working fluid evaporator 11 and the condenser 12, and a large proportion of the heat absorbed in the working fluid evaporator 11 is available in the condenser 12 for release to the cooling medium flow.The operating mode of the working fluid circuit 10 with active bypass can also be referred to as "heat transfer operation," in which, for example, up to 98% of the heat absorbed from the source medium flow in the working fluid evaporator 11 can be transferred to the cooling medium flow via the condenser 12. By switching the bypass valve 17, the device 100 can be converted from "normal operation" (inactive bypass) to "heat transfer operation" (at least partially active bypass), and vice versa. The device 100 according to the invention further comprises a throttling element 18 arranged in the expansion machine bypass line 19, in particular comprising a throttle orifice. The throttling element 18 expands the working fluid as it passes through the expansion machine bypass line 19 without extracting enthalpy from it.The expansion machine bypass line 19 branches off upstream of the expansion machine E and downstream of the working fluid evaporator 11, with the bypass valve 18 also being located upstream of the expansion machine E. Downstream of the expansion machine E, the expansion machine bypass line 19 rejoins the main line, in particular upstream of the recuperator 16. Working fluid vapor from the working fluid evaporator 11 can therefore be diverted upstream of the expansion machine E via the expansion machine bypass line 19 to bypass it, and reintroduced upstream of the recuperator 16. Figure 4 shows a device 100 according to the invention for generating electrical and / or mechanical energy according to a second embodiment.Since the device 100 according to the second embodiment largely corresponds to the device 100 according to the first embodiment, only the differences will be discussed. Similar to the prior art device 100 shown in Fig. 2, the device according to the invention shown in Fig. 4 also comprises a source heat exchanger 14, to which source medium exiting from the source medium outlet 111 of the working medium evaporator 11 is supplied. The source medium flow to the source heat exchanger 14 can, for example, be at a temperature T. Q_WT_ein supplied at 200 °C. Neglecting heat losses, T Q_WT_ein essentially T Q_V_ausIn the source heat exchanger 14, further thermal energy is extracted from the source medium flow, so that the source medium flow can leave the source heat exchanger 14 at a source medium outlet 141, for example, at a temperature TQ_WT_out of 70 °C. The source medium flow flows on a primary side of the source heat exchanger 14. Fluidically separated from this, the source heat exchanger 14 comprises a secondary side through which a heat transfer medium flows to transfer heat from the source medium flow to the heat transfer medium flow. The heat transfer medium flow can be part of a useful heat circuit, in particular a heating circuit. Specifically, the heat transfer medium flow through the secondary side of the source heat exchanger 14 can couple heat into the same useful heat circuit to which the condenser 12 also supplies thermal energy.In other words, the source heat exchanger 14 can be supplied with the same cooling medium flow on its secondary side as the condenser 12 on its secondary side. The cooling medium for this flow can be supplied at 60 °C (useful heat circuit return) at the cooling medium inlet of the source heat exchanger's secondary side. This corresponds to the inlet temperature T. KM_WT_einof the cooling medium into the source heat exchanger 14. The cooling medium can leave the source heat exchanger 14 at the cooling medium outlet of the source heat exchanger's secondary side with an outlet temperature TKM_WT_out of, for example, 80 °C. This corresponds to the temperature of a useful heat circuit supply. By combining the source heat exchanger 14 with the bypass option for the expansion machine E provided according to the invention, the amount of heat extractable from the source medium flow, particularly for heating purposes, can be further increased. Figure 5 shows a device 100 according to the invention for generating electrical and / or mechanical energy according to a third embodiment. Since the device 100 according to the third embodiment largely corresponds to the device 100 according to the first embodiment, only the differences will be discussed.Furthermore, reference is also made to the description of the device 100 according to the prior art as shown in Fig. 1. The device 100 according to the third embodiment comprises a further bypass valve 171 arranged in the working fluid circuit 10 of the ORC system, which can be switched to bypass the recuperator 16 via a recuperator bypass line 191. In this way, in the operating mode "heat transfer operation", the recuperator 16 can be bypassed in addition to the expansion machine E. By bypassing the recuperator 16, the liquid working fluid is not preheated before it is fed to the working fluid evaporator 11, thus providing a larger temperature gradient at the working fluid evaporator 11 for heat transfer from the source medium flow.This means that, with the same inlet temperature of the source medium flow into the working fluid evaporator 11 TQ_V_ein of 500 °C, the source medium flow in the working fluid evaporator 11, for example, reaches a temperature T. Q_V_ausThe working fluid vapor can be cooled from 70 °C. Since the working fluid vapor is not cooled in the recuperator 16 when the expansion machine bypass line 19 is active, it reaches the primary side of the condenser 12 at a higher temperature, for example, 280 °C. Consequently, the temperature level available at the condenser 12 is also increased, for example, to up to 200 °C. In other words, the cooling medium can leave the condenser 12 at the cooling medium outlet of the secondary side of the condenser with an outlet temperature TKM_K_out of up to 200 °C. It is evident that a supply line for the useful heat circuit at this temperature level opens up a significantly broader range of applications and allows for considerably higher thermal power densities. The recuperator bypass line 191 branches off particularly upstream of the recuperator 16, with the further bypass valve 171 also being arranged upstream of the recuperator 16.The recuperator bypass line 191 is specifically designed to bypass the recuperator 16 on the recuperator primary side, i.e., the steam side. Downstream of the recuperator 16, the recuperator bypass line 191 re-enters the system. Figure 6 shows a device 100 according to the invention for generating electrical and / or mechanical energy according to a fourth embodiment. Since the device 100 according to the fourth embodiment largely corresponds to the device 100 according to the third embodiment, only the differences will be discussed. The main difference lies in the further energetic utilization of the source medium flow exiting the source medium outlet 111 of the working fluid evaporator 11 in a heat pump 20. The source medium flow leaves the working fluid evaporator 11 at a temperature TQ_V_out of, for example, 70 °C and re-enters at a temperature T. Q_WT_ein, which, neglecting heat losses, essentially T Q_V_aus The heat can be supplied on a primary side of a source heat exchanger to a source heat exchanger 14, which is formed by an evaporator 21 of the heat pump 20 and through which a working fluid of the heat pump 20 flows on the secondary side. In the source heat exchanger 14, which is designed as the evaporator 21 of the heat pump 20, additional heat is extracted from the source fluid flow and transferred to the working fluid of the heat pump 20. The use of a heat pump 20 now makes it possible to cool the source fluid flow to a significantly lower temperature level, whereby the temperature T Q_WT_ausThe temperature at which the source medium flow leaves the source heat exchanger 14, which is designed as the evaporator 21 of the heat pump 20, can be, for example, 5 °C. In addition to the evaporator 21, the heat pump 20 comprises a compressor K with a motor M, a condenser 22, and an expansion element 28. The condenser 22 of the heat pump 20 is supplied with the working medium of the heat pump 20 on its primary side and with a cooling medium flow on its secondary side to transfer heat from the working medium of the heat pump 20 to the cooling medium. The cooling medium flow can be part of a useful heat circuit, in particular a heating circuit. Specifically, the cooling medium flow passing through the condenser 22 of the heat pump 20 on its secondary side can couple heat into the same useful heat circuit to which the condenser 12 of the ORC system also supplies thermal energy.In other words, the condenser 22 of the heat pump 20 can be supplied with the same cooling medium flow on its secondary side as the condenser 12 of the ORC system on its secondary side. The cooling medium can be supplied at 60 °C (useful heat circuit return) at the cooling medium inlet on the secondary side of the condenser 22 of the heat pump 20. This corresponds to the inlet temperature TKM_WP_in of the cooling medium entering the condenser 22 of the heat pump 20. The cooling medium can exit the condenser 22 of the heat pump 20 at the cooling medium outlet on the secondary side of the condenser 22 of the heat pump 20 with an outlet temperature T. KM_WP_ausfrom, for example, 80 °C. This corresponds to the temperature of a useful heat circuit supply. Figure 7 shows a device 100 according to the invention for generating electrical and / or mechanical energy according to a fifth embodiment. Since the device 100 according to the fifth embodiment largely corresponds to the device 100 according to the fourth embodiment, only the differences will be discussed. The heat pump 20, in particular the motor M of the heat pump 20, which drives the compressor K, can be driven at least partially by electrical and / or mechanical energy generated by the expansion machine E of the ORC system. For this purpose, an electrical connecting line 200 is provided, which electrically couples the heat pump 20, in particular the motor M, to a generator G driven by the expansion machine E of the ORC system. In Figure 7, the device 100 is shown in the diagram.Figure 8 shows a device 100 according to the invention for generating electrical and / or mechanical energy according to a sixth embodiment. Since the device 100 according to the sixth embodiment largely corresponds to the device 100 according to the fourth embodiment, only the differences will be discussed. The difference consists in particular in that an admixture stream 300 is added to the source medium stream downstream of the working fluid evaporator 11 of the ORC system and upstream of the source heat exchanger 14, which is designed as an evaporator 21 of the heat pump 20. This admixture stream provides additional heat, in particular low-temperature heat. The admixture stream 300 can, for example, contain heat from the environment or from an (industrial) process.By mixing the source medium stream exiting the working fluid evaporator 11 at a temperature TQ_V_out of, for example, 70 °C with an admixture stream 300 at a temperature of, for example, 20 °C, a mixture temperature of, for example, 40 °C can be obtained, which can be raised by the heat pump 20 to the temperature level TKM_WP_out for use in the useful heat circuit, in particular the heating circuit. It is readily apparent that by adding the admixture stream 300, even more useful heat, especially for heating purposes, can be provided. Figure 9 shows a device 100 according to the invention for generating electrical and / or mechanical energy according to a seventh embodiment. Since the device 100 according to the seventh embodiment largely corresponds to the device 100 according to the third embodiment (see Figure 5), only the differences will be discussed.Furthermore, reference is also made to the description of the prior art device 100 according to Fig. 1. The device 100 according to the seventh embodiment also has a recuperator bypass line 191. However, this bypass line is configured to bypass the recuperator 16 on the recuperator secondary side, i.e., on the fluid side. The recuperator bypass line 191 branches off upstream of the recuperator 16, with the further bypass valve 171 also being arranged upstream of the recuperator 16. The recuperator bypass line 191 rejoins the recuperator 16 downstream.

[0002] Reference numeral list 100 Device for generating electrical and / or mechanical energy 10 Working fluid circuit 11 Working fluid evaporator 111 Source medium outlet of the working fluid evaporator 12 Condenser 14 Source heat exchanger 141 Source medium outlet of the source heat exchanger 15 Feed pump 16 Recuperator 17 Bypass valve expansion machine 171 Bypass valve recuperator 18 Throttle body 19 Bypass line expansion machine 191 Bypass line recuperator 20 Heat pump 21 Evaporator heat pump 22 Condenser heat pump 28 Expansion element heat pump 200 Electrical connecting line 300 Mixing flow E Expansion machine G Generator N Power grid M Motor heat pump TQ_V_in Inlet temperature Source medium flow in working fluid evaporator T Q_V_aus Outlet temperature of source medium flow from working fluid evaporator TQ_WT_in Inlet temperature of source medium flow into source heat exchanger T Q_WT_aus Outlet temperature of source medium flow from source heat exchanger TKM_K_ein Inlet temperature of cooling medium to condenser TKM_K_off Outlet temperature of cooling medium from condenser TKM_WP_on Inlet temperature of cooling medium to heat pump TKM_WP_off Outlet temperature of cooling medium from heat pump

Claims

1. Claims 1. Device (100) for generating electrical and / or mechanical energy with an ORC system, which has a working medium circuit (10) for a working medium, the working medium circuit (10) comprising a working medium evaporator (11), an expansion machine (E) that can be operated with working medium vapor from the working medium evaporator (11), and a condenser (12), the working medium evaporator (11) being flowable through by a source medium flow on a working medium evaporator primary side to transfer heat energy contained in the source medium flow to the working medium and thereby at least partially evaporate the working medium, the condenser (12) being flowable through by a cooling medium flow on a condenser secondary side,to transfer at least part of the thermal energy contained in the working medium to a coolant contained in the coolant stream and thereby at least partially to condense the working medium, wherein at least one bypass valve (17) is arranged in the working medium circuit (10), which can be switched to bypass the expansion machine (E) through an expansion machine bypass line (19), and thereby at least temporarily transfer an increased proportion of the thermal energy absorbed in the working medium evaporator (11) from the working medium to the coolant of the coolant stream., 2. The device (100) according to claim 1, wherein at least one throttle member (18), in particular comprising a throttle valve, is arranged in the expansion machine bypass line (19).

3. The device (100) according to claim 1 or 2, wherein the expansion machine bypass line (19) branches off upstream of the expansion machine (E), in particular wherein the bypass valve (17) is arranged upstream of the expansion machine (E).

4. The device (100) according to any one of the preceding claims, comprising a recuperator (16) which is flowable through by working medium steam from the expansion machine (E) on a recuperator primary side and is flowable through by liquid working medium on a recuperator secondary side before the liquid working medium is fed to the working medium evaporator (11). 5.Device (100) according to one of the preceding claims, wherein in the working medium circuit (10) at least one further bypass valve (171) is arranged, which is switchable to bypass the recuperator (16) via a recuperator bypass line (191).

6. Device (100) according to claim 5, wherein the recuperator bypass line (191) branches off upstream of the recuperator (16), in particular wherein the further bypass valve (171) is arranged upstream of the recuperator (16).

7. Device (100) according to claim 5 or 6, wherein the recuperator bypass line (191) is configured to bypass the recuperator (16) on the recuperator primary side and / or the... To bypass the recuperator secondary side.

8. The device (100) according to any one of the preceding claims, comprising at least one source heat exchanger (14, 21) which is arranged downstream of the working medium evaporator (11) and is flowable through by the source medium flow on a source heat exchanger primary side and is configured to extract further heat energy from the source medium flow.

9. The device (100) according to claim 8, wherein the source heat exchanger (14, 21) is flowable through by a heat transfer medium of a heat transfer medium flow on a source heat exchanger secondary side to transfer heat from the source medium flow to the heat transfer medium flow, in particular wherein the heat transfer medium flow is part of a useful heat circuit, in particular a heating circuit. 10.Device (100) according to claim 8, comprising a heat pump (20), wherein the source heat exchanger (14, 21) can be flowed through by a working medium of the heat pump (20) on a source heat exchanger secondary side to transfer heat from the source medium flow to the working medium of the heat pump (20).

11. Device (100) according to claim 10, wherein the heat pump (20) can be at least partially driven by electrical and / or mechanical energy generated by the expansion machine (E) of the ORC plant.

12. Device (100) according to any one of the preceding claims, comprising a feed pump (15) for conveying liquid working medium into the working medium evaporator (11), in particular wherein the feed pump (15). is arranged downstream of the capacitor (12), in particular upstream of the recuperator (16). 13.Device (100) according to claim 1, wherein at least one throttle member (17), in particular comprising a throttle valve, is arranged in the expansion machine bypass line (19), and wherein the expansion machine bypass line (19) branches off upstream of the expansion machine (E) and the bypass valve (17) is arranged upstream of the expansion machine (E), and comprising a recuperator (16) which is flowable through by working medium steam on a recuperator primary side from the expansion machine (E) and is flowable through by liquid working medium on a recuperator secondary side before the liquid working medium is fed to the working medium evaporator (11), wherein at least one further bypass valve (171) is arranged in the working medium circuit (10) and is switchable to bypass the recuperator (16) through a recuperator bypass line (191). 14.Method for operating a working medium circuit (10) of an ORC plant, in which liquid working medium is evaporated in a working medium evaporator (11) with heat absorption from a source medium stream and can be supplied as working medium vapor to an expansion machine (19) in which the working medium can be expanded, and in which working medium vapor is condensed in a condenser (12) with heat dissipation to a cooling medium of a cooling medium stream, wherein the expansion machine (E) can be bypassed by a bypass valve (17) through an expansion machine bypass line (19) in order to thereby at least temporarily achieve an increased proportion. to transfer the heat energy absorbed in the working medium evaporator (11) from the working medium to the cooling medium of the cooling medium flow.

15. The method according to claim 14, wherein working medium vapor can be passed through a primary side of a recuperator (16) of a recuperator from the expansion machine (E), and wherein liquid working medium can be passed through a secondary side of the recuperator (16) of the recuperator before the liquid working medium is fed to the working medium evaporator (11), wherein the recuperator (16) can be bypassed by a further bypass valve (171) through a recuperator bypass line (191) to minimize heat transfer between the working medium vapor on the primary side of the recuperator and the liquid working medium on the secondary side of the recuperator. 16.A method according to any one of claims 14 or 15, wherein the source medium stream is fed to a primary side of a source heat exchanger (14, 21) of a source heat exchanger after passing through the working medium evaporator (11), in which further heat is removed from the source medium stream.

17. The method according to claim 16, wherein the source heat exchanger (14, 21) is flowed through on a secondary side of the source heat exchanger by a heat transfer medium of a heat transfer medium stream to transfer heat from the source medium stream to the heat transfer medium stream, in particular wherein the heat transfer medium stream is part of a useful heat circuit, in particular a heating circuit.

18. The method according to claim 16, wherein the source heat exchanger (14, 21) is flowed through on a secondary side of the source heat exchanger by a working medium of a heat pump (20) to transfer heat from the source medium stream to the... To be transferred to the working medium of the heat pump (20).

19. The method according to claim 18, wherein the heat pump (20) is at least partly driven by electrical and / or mechanical energy generated by the expansion machine (E) of the ORC system.

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