Power generating apparatus and working medium circulation operation method

Abstract

The invention relates to a device (10) for generating electrical or mechanical energy, comprising a residual current (RC) system. The RC system can, in particular, be configured as an organic residual cycle (ORC) system. The RC system has a working fluid circuit (12) for a working fluid, in which a working fluid evaporator (14), an expansion machine (16) operated with working fluid vapor from the working fluid evaporator, and a condenser (18) are arranged. According to the invention, a vapor cooler (20) is located in the working fluid circuit (12) between the expansion machine (16) and the condenser (18). The vapor cooler (20) serves to convert working fluid vapor (35) flowing from the expansion machine (16) into saturated working fluid vapor (36), which the condenser (18) receives in order to form liquid working fluid (30). The invention also relates to a method for operating a working fluid circuit (12).

Description

[0001] The invention relates to a device for generating electrical or mechanical energy with an RC system, in particular with an ORC system, which has a working fluid circuit for a working fluid in which a working fluid evaporator as well as an expansion machine operated with working fluid vapor from the working fluid evaporator and a condenser are arranged.

[0002] An RC system (RC = Rankine Cycle) within the meaning of the invention is understood to be a system in which heat is converted into mechanical or electrical energy by means of a thermodynamic cycle process using a working medium, e.g. water or steam, which is circulated in a working medium cycle.

[0003] An ORC plant (ORC = Organic Rankine Cycle) is an RC plant that uses a thermodynamic cycle to generate mechanical or electrical energy from heat. InIn an ORC system, there is a working fluid cycle similar to a steam cycle. However, instead of water vapor, the working fluid in this cycle typically consists of organic media, such as butane, toluene, silicone oil, or ammonia, which have a lower evaporation temperature than 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 may, for example, be a steam turbine. InIn the expansion engine, the working fluid is expanded to a lower pressure, generating mechanical energy, and then condensed in a condenser, from which the liquid working fluid returns to the working fluid reservoir. From there, the working fluid is returned to the working fluid evaporator in the recirculation 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 particularly advantageous for generating electrical or mechanical energy from heat when the available temperature difference between a heat source and a heat sink is too small to operate a heat engine, such as a turbine, with steam.

[0004] ORC systems are not only operated using heat from combustion plants. The heat required to operate an ORC system can also be obtained geothermalally or from solar power plants. Furthermore, ORC systems can also be operated using the waste heat from internal combustion engines (e.g., reciprocating engines).

[0005] The efficiency of ORC systems generally increases with the temperature at which the evaporated working fluid expands in the expansion chamber. Efficient operation of ORC systems is particularly possible when the temperature TE of the working fluid vapor at the inlet of the expansion chamber is in the range of approximately 150 °C ≤ TE ≤ 300 °C. It is known that the efficiency of an ORC system can be increased if the working fluid vapor, after expansion in the expansion chamber, is passed through a recuperator in which residual heat from the working fluid vapor is transferred to the liquid working fluid supplied to the working fluid evaporator.

[0006] The use of recuperators in ORC systems involves considerable investment costs, as they must withstand high temperatures and large temperature differentials occur within them. Furthermore, the use of recuperators in an ORC system inevitably results in a pressure drop between the expansion engine and the condenser, which negatively impacts the expansion engine's performance. Additionally, due to the preheating of the refrigerant supplied to the evaporator in the recuperator, the mean temperature difference of the evaporator is reduced, necessitating a larger evaporator to ensure sufficient working fluid vapor is available for the expansion engine.

[0007] Furthermore, when using gaseous heat sources such as flue gas to operate the working fluid evaporator, significantly less cooling is achievable than when heat is transferred from a liquid heat transfer fluid to the working fluid used in the ORC system. Therefore, in ORC systems with a working fluid evaporator that draws its heat of vaporization from a gaseous heat source, a heat exchanger is commonly used downstream of the evaporator. This heat exchanger serves to extract residual heat from the gaseous heat transfer fluid flowing through the evaporator at its outlet.

[0008] From US patent 2018 / 0353873 A1, a device for generating electrical energy is known which includes a condenser that cools the working fluid vapor flowing from a turbine. In the condenser, heat is isothermally extracted from the working fluid vapor, causing the vaporous working fluid to condense into a liquid working fluid. The liquid working fluid is then pumped to an evaporator, where it is vaporized by the addition of waste heat from exhaust gases, in order to then drive the turbine.

[0009] In DE 10 2017 125 355 B3 a device for generating electrical energy is described which has a steam cooler in which working fluid steam from the turbine is condensed and thus cooled.

[0010] DE 10 2020 200 720 A1 describes a steam cooler that serves to convert superheated steam into saturated steam.

[0011] The object of the invention is to provide a device for generating electrical or mechanical energy with an RC system that can be operated with good efficiency at reduced investment costs.

[0012] This problem is solved by a device for generating electrical or mechanical energy according to claim 1 and the method according to claim 15. Advantageous embodiments and further developments of the invention are specified in the dependent claims.

[0013] An inventive device for generating electrical or mechanical energy includes a residual current (RC) system. This RC system can, in particular, be configured as an organic residual cycle (ORC) system. It comprises a working fluid circuit for a working fluid, in which a working fluid evaporator, an expansion machine operated with working fluid vapor from the working fluid evaporator, and a condenser are arranged. A vapor cooler is arranged in the working fluid circuit between the expansion machine and the condenser. The vapor cooler serves to convert the working fluid vapor flowing from the expansion machine into saturated working fluid vapor, which the condenser receives to form liquid working fluid.

[0014] In the invention, "working fluid vapor" refers to a working fluid whose state of matter is gaseous. "Saturated working fluid vapor" is understood to mean a gaseous working fluid that is in thermodynamic equilibrium with a liquid working fluid and is also referred to as saturated working fluid vapor. "Supercooled liquid working fluid" is understood to mean a liquid working fluid whose temperature is below the boiling point of the working fluid. "Saturated liquid working fluid" is understood in the invention to mean a liquid working fluid at the temperature and pressure at the transition between the liquid and gaseous states of matter of the working fluid.

[0015] The invention is based on the idea that the technical requirements for the condenser in a residual current (RC) system, particularly in an organic residual current (ORC) system, can be reduced if it receives only saturated steam for condensation and is not supplied with superheated steam, which leads to large temperature differences within the condenser. A key aspect of the invention is to lower the temperature of the liquid working fluid that the working fluid evaporator in an RC system, especially an ORC system, receives compared to the temperature of working fluid in such a system operated with a recuperator. In this way, by transferring the heat carried in an exhaust gas stream to the working fluid in the working fluid evaporator, it is possible to extract heat from the exhaust gas stream without an exhaust gas heat exchanger downstream of the working fluid evaporator.

[0016] The steam cooler can have a pressure vessel which has a first port for supplying working fluid vapor from the expansion machine into the pressure vessel, a second port communicating with the condenser for supplying working fluid saturated steam to the condenser, and a third port for discharging liquid working fluid which the working fluid evaporator receives.

[0017] It is advantageous if the pressure vessel has a saturated steam reservoir for receiving saturated working fluid and a liquid reservoir communicating with this reservoir for receiving liquid working fluid.

[0018] Preferably, the device for introducing the working fluid vapor from the expansion machine into the liquid working fluid is designed to introduce the working fluid vapor from the expansion machine into the liquid working fluid below a fill level of the liquid working fluid in the liquid reservoir.

[0019] In particular, it is advantageous if the first connection for supplying working fluid vapor from the expansion machine is connected to the liquid reservoir by a device for introducing the working fluid vapor from the expansion machine into liquid working fluid.

[0020] In this way, the flow resistance of the working fluid moving through the circuit during heat transfer can be kept low. Furthermore, this approach allows the condenser to withstand only low pressures and not excessively high temperatures, enabling it to be designed, for example, as a brazed plate heat exchanger. This also allows for a compact working fluid evaporator design, as it does not receive working fluid preheated in a recuperator, thus enabling increased source cooling. An additional exhaust gas heat exchanger for reducing the gas flow temperature can then be omitted.

[0021] Since the working fluid is routed through the condenser even if the steam cooler fails, the system still allows for emergency operation in this case and therefore has good reliability. The same applies if the condenser fails, as the working fluid evaporator can still receive liquid working fluid from the steam cooler.

[0022] The device for introducing the working fluid vapor from the expansion engine into the liquid working fluid preferably comprises several tubes, which can form a tube bundle and which project into the liquid reservoir. Each tube has an inlet opening for working fluid vapor from the expansion engine and an outlet opening for the flow of working fluid vapor into the liquid working fluid in the liquid reservoir. The corresponding tubes can be routed through the saturated steam reservoir.

[0023] The device for generating electrical or mechanical energy can have a working fluid vapor reservoir that communicates with the liquid reservoir via a multitude of pipes. The first connection for supplying working fluid vapor from the expansion engine can communicate with the liquid reservoir, which is formed within a porous body, via a vapor channel.

[0024] It is also possible that the first connection for supplying working fluid vapor from the expansion machine communicates with the liquid reservoir via a steam channel, which leads into a stack of plates with steam channels formed therein.

[0025] Furthermore, it is possible that the first connection for supplying working fluid vapor from the expansion machine communicates with the liquid reservoir via a steam channel, the steam channel running in a pipe body closed at one end with micro-openings.

[0026] The pressure vessel may have a fourth port for introducing liquid working fluid from the condenser into the liquid reservoir.

[0027] A return line may be provided which is designed to return liquid working fluid formed in the condenser to the vapor cooler.

[0028] It is advantageous if the condenser is designed as a plate heat exchanger, which extracts heat from the saturated working fluid vapor and transfers it to the cooling water flowing through the plate heat exchanger. A feed pump can be provided for conveying liquid working fluid from the pressure vessel to the working fluid evaporator.

[0029] The working fluid evaporator can be designed as a heat exchanger that transfers heat from a fluid flowing through the heat exchanger to the working fluid. The flowing fluid can be, for example, a gaseous fluid, especially flue gas.

[0030] In a method according to the invention for operating a working fluid circuit in which liquid working fluid is evaporated and supplied as a vaporous working fluid to an expansion machine in which the working fluid is expanded, the working fluid expanded in the expansion machine is first converted into saturated working fluid vapor by cooling in a vapor cooler and only then into liquid working fluid by condensation in a condenser, which is again evaporated and made available to the expansion machine for expansion.

[0031] It is advantageous if the liquid working fluid formed in the condenser is returned to the vapor cooler.

[0032] In particular, it is advantageous if working fluid vapor from the expansion machine is introduced into the liquid working fluid in a liquid reservoir of the pressure vessel below a fill level of the liquid working fluid.

[0033] In this way, the flow resistance of the working fluid moving through the circuit during heat transfer can be kept low. Furthermore, this approach allows the condenser to withstand only low pressures and not excessively high temperatures, enabling it to be designed, for example, as a brazed plate heat exchanger. This also allows for a compact working fluid evaporator design, as it does not receive working fluid preheated in a recuperator, thus enabling increased source cooling. An additional exhaust gas heat exchanger for reducing the gas flow temperature can then be omitted.

[0034] Since the working fluid is routed through the condenser even if the steam cooler fails, the system still allows for emergency operation in this case and therefore has good reliability. The same applies if the condenser fails, as the working fluid evaporator can still receive liquid working fluid from the steam cooler.

[0035] The RC or ORC system in the device according to the invention can be designed as a small or large residential system, a large industrial system, or a power plant, for example, for municipalities. A residential system, as used here, is understood to be a system that can ensure the energy supply, including air conditioning, of office buildings, garages, and hospitals. An industrial system, as used here, is defined as a system that supplies industrial production facilities, particularly those in the automotive industry, e.g., paint shops, with electrical energy, for which not only electricity but also heat at different temperature levels must be provided to operate the system. The device according to the invention has a simple design. The corresponding investment costs are therefore low. A device according to the invention can therefore operate with low operating costs.A device according to the invention is particularly suitable for operation in low power ranges for energy and heat.

[0036] Advantageous embodiments of the invention are shown in the drawings and are described below.

[0037] They show: Fig. 1 a first device for generating energy with an ORC system; Fig. 2 an enlarged view of a device for introducing working fluid vapor into liquid working fluid in a vapor cooler of the first device; Fig. 3 a second device for generating energy with an ORC system; Fig. 4 a third device for generating energy with an ORC system; Fig. 5 an enlarged view of a device for introducing working fluid vapor into liquid working fluid in a vapor cooler of the third device; Fig. 6 a fourth device for generating energy with an ORC system; and Fig. 7 an enlarged view of a device for introducing working fluid vapor into liquid working fluid in a vapor cooler of the fourth device.

[0038] The one in Fig. 1The first device 10 shown for generating electrical or mechanical energy comprises an ORC system with a working fluid circuit 12 for a working fluid. This circuit includes a working fluid evaporator 14 for evaporating the working fluid, an expansion engine 16 in the form of a gas turbine operated by working fluid vapor from the working fluid evaporator 14, and a condenser 18, which serves to condense the saturated working fluid vapor into liquid working fluid. The working fluid can be, for example, ethylbenzene. However, it is also possible to use butane, toluene, silicone oil, or ammonia as the working fluid in the circuit. The expansion engine 16 has an output shaft that serves to transmit mechanical energy to a load. To generate electrical energy, the expansion engine 16 can, for example, be connected to an electric generator.

[0039] InIn the working fluid circuit 12, a steam cooler 20 is located between the expansion machine 16 and the condenser 18. The steam cooler 20 has the technical function of converting the working fluid steam 35 flowing from the expansion machine 16, which may be superheated at a temperature T ≈ 270 °C, into saturated working fluid steam 36 by cooling, which is then supplied to the condenser 18.

[0040] The steam cooler 20 has a pressure vessel 22 with a first connection 24 for supplying working fluid vapor from the expansion machine 16. The pressure vessel 22 of the steam cooler 20 has a second connection 26, which is connected to the condenser 18 for supplying saturated working fluid steam 36 to the pressure vessel 22. The pressure vessel 22 has a third connection 28 through which liquid working fluid 30 can be discharged from the pressure vessel 22 to be conveyed to the working fluid evaporator 14 via a delivery line with a feed pump 32.

[0041] InThe pressure vessel 22 has a saturated steam reservoir 34, which serves to receive working medium saturated steam 36, and a liquid reservoir 38 communicating with the saturated steam reservoir 34, which has a fill level 39 up to which it is filled with liquid working medium 30 and whose technical function is to receive liquid working medium 30.

[0042] The first connection 24 for supplying working fluid vapor from the expansion machine 16 is connected to the liquid reservoir 38 by a device 40 for introducing the working fluid vapor from the expansion machine 16 into the liquid working fluid 30. The device 40 for introducing the working fluid vapor from the expansion machine 16 into the liquid working fluid with the liquid reservoir 38 has several tubes 42, forming a tube bundle and projecting into the liquid reservoir 38.

[0043] The Fig. 2Figure 40 is an enlarged view of the device 40 for introducing the working fluid vapor from the expansion machine 16 into the liquid working fluid 30. The pipes 42 each have an inlet opening 44 for working fluid vapor from the expansion machine 16 and an outlet opening 46 for the flow of working fluid vapor into the liquid working fluid in the liquid reservoir 38.

[0044] The pipes 42 extend from a pressure vessel register section 48 into the liquid reservoir 38 of the pressure vessel 22, passing through the saturated steam reservoir 34. The outlet opening 46 of the pipes 42 is immersed in the liquid working fluid in the liquid reservoir 38. The pressure vessel register section 48 is fluid-tightly separated from the saturated steam reservoir 34 of the pressure vessel 24 by a partition 37. The pipes 42 extend from the pressure vessel register section 48 to the liquid reservoir 38, passing through the saturated steam reservoir 34 formed in the pressure vessel 22.

[0045] The vaporous working fluid supplied to the expansion machine 16 at a pressure p A ≈ 14 bar is expanded in the expansion machine to a pressure p E ≈ 0.2 bar and enters the pressure vessel register section 48 as working fluid vapor 35 through the first connection 24 of the pressure vessel 22. There it flows through the inlet opening 44 of the tubes 42 and enters the liquid reservoir 38, into which it flows through the outlet opening 46 of the tubes 42 into the liquid working fluid 30. Since the pressure p E ≈ 0.2 bar at the outlet of the expansion machine 16 is slightly greater than the hydrostatic pressure of the liquid working fluid 30, the working fluid vapor 35 can enter the liquid working fluid 30, forming small vapor bubbles 47 which rise into the saturated steam reservoir 34 and thereby transfer heat to the liquid working fluid 30 through contact with it.

[0046] The saturated steam 36 from the saturated steam reservoir 34 of the pressure vessel 22 enters the condenser 18 via the second port 26 of the pressure vessel 22 and a feed line 27. In the condenser 18, the saturated steam 36 condenses into liquid working fluid 30, which is returned from the condenser 18 to the pressure vessel 22 via a return line 49 and a fourth port 50. The liquid working fluid 30 is fed through the fourth port 50 of the pressure vessel 22 into the liquid reservoir 38 formed therein. The liquid working fluid 30 then enters the pressure vessel 22 via the return line 49 and the fourth port 50.

[0047] The condenser 18 is designed as a plate heat exchanger, which transfers the heat of the working fluid saturated steam to cooling water, which flows through the plate heat exchanger and is supplied to it by a cooling water line 52.

[0048] The liquid working fluid, supplied to the working fluid evaporator 14 by means of the feed pump 32, absorbs heat from a heat transfer fluid 54 in the working fluid evaporator 14, whereby the working fluid's state of matter changes from the liquid state to the gaseous state. The heat transfer fluid 54 is the exhaust gas from a combustion process. It should be noted that the heat transfer fluid can, in principle, also be a different fluid, in particular a liquid.

[0049] The one in Fig. 3 The second device 10' shown for generating energy with an ORC system has a steam cooler 20' that is modified compared to the steam cooler 20 in the first device 10. Corresponding assemblies and elements in Fig. 1 and Fig. 3 are identified by identical numbers as reference symbols.

[0050] The steam cooler 20' has a pressure vessel 22 with a first port 24 for supplying working fluid steam from the expansion machine 16 and a second port 26, which is connected to the condenser 18 for supplying saturated working fluid steam 36 to the pressure vessel 22. The pressure vessel 22 has a third port 28 through which liquid working fluid 30 can be discharged from the pressure vessel 22 to be conveyed to the working fluid evaporator 14 via a delivery line 30 with a feed pump 32.

[0051] The pressure vessel 24 contains a saturated steam reservoir 34, which serves to hold working medium saturated steam 36, and a liquid reservoir 38 communicating with this reservoir, whose technical function is to hold liquid working medium.

[0052] The first port 26 for supplying working fluid vapor from the expansion machine 16 is connected to the liquid reservoir 38 by a device 40' for introducing the working fluid vapor from the expansion machine 16 into the liquid working fluid. The device 40' for introducing the working fluid vapor from the expansion machine 16 into the liquid working fluid with the liquid reservoir 38 has a vapor channel 56 which communicates with the liquid reservoir 38 through a porous body 58 projecting into the liquid reservoir 38 in the pressure vessel 22. The porous body 58 is immersed in the liquid working fluid 30 in the liquid reservoir 38.The technical function of the porous body 58 is that it allows the working fluid vapor from the expansion machine 16 to pass through it in a finely dispersed manner into the liquid working fluid 30 in the liquid reservoir 38, so that heat is transferred to the liquid working fluid 30 in the liquid reservoir 38 over a large surface area. Small vapor bubbles 47 then form in the liquid working fluid 30, which rise into the saturated vapor reservoir 34 and transfer heat to the liquid working fluid 30 through contact with it.

[0053] The one in Fig. 4 The third device 10" shown, for generating energy with an ORC system, also has a steam cooler 20" that is modified compared to the steam cooler 20 in the first device 10. Corresponding assemblies and elements in Fig. 1 and Fig. 3 as well as Fig. 4 are identified by identical numbers as reference symbols.

[0054] The first connection 26 for supplying working fluid vapor from the expansion machine 16 is connected here to the liquid reservoir 38 by a device 40" for introducing the working fluid vapor from the expansion machine 16 into the liquid working fluid. The device 40" for introducing the working fluid vapor from the expansion machine 16 into the liquid working fluid 30 with the liquid reservoir 38 has a vapor channel 58 which communicates with the liquid reservoir 38 via a distributor body 60 projecting into the liquid reservoir 38 in the pressure vessel 22. The distributor body 60 is immersed in the liquid working fluid 30 in the liquid reservoir 38.

[0055] The Fig. 5Figure 40 is an enlarged view of the device for introducing the working fluid vapor from the expansion machine 16 into the liquid working fluid 30. The vapor channel 58 opens into a distributor body 60 with a flat channel arrangement in a plate stack, similar to a plate heat exchanger. In the distributor body 60, the working fluid vapor from the vapor channel 58 flows through stacked flat channels, each with a slot-shaped opening 62 through which the working fluid vapor from the vapor channel 58 can enter the liquid working fluid 30 in the liquid reservoir 38 in the direction indicated by the arrows 64.

[0056] The steam channel 58 communicates with the liquid reservoir 38 via the flat channels. Since the pressure p E ≈ 0.2 bar at the outlet of the expansion machine 16 is slightly higher than the hydrostatic pressure of the liquid working fluid 30, the working fluid vapor 35 can enter the liquid working fluid 30, forming small vapor bubbles 47 that rise into the saturated steam reservoir 34 and transfer heat to the liquid working fluid 30 through contact with it. The technical function of the stacked flat channels is to allow the working fluid vapor from the expansion machine 16 to pass through them as finely dispersed vapor bubbles 47 into the liquid working fluid in the liquid reservoir 38, thus enabling heat transfer to the liquid working fluid in the liquid reservoir 38 over a large surface area.

[0057] The one in Fig. 6The fourth device 10‴ shown, for generating energy with an ORC system, also has a steam cooler 20‴ that is modified compared to the steam cooler 20 in the first device 10. Corresponding assemblies and elements in Fig. 1 , Fig. 3 and Fig. 4 are identified by identical numbers as reference symbols.

[0058] The first connection 24 for supplying working fluid vapor from the expansion machine 16 is connected here to the liquid reservoir 38 by a device 40‴ for introducing the working fluid vapor from the expansion machine 16 into the liquid working fluid. The device 40‴ for introducing the working fluid vapor from the expansion machine 16 into the liquid working fluid with the liquid reservoir 38 has a vapor channel 56 which runs in a pipe body 66 closed at one end and with micro-openings 68.

[0059] The Fig. 7is an enlarged view of the device 40‴ for introducing working fluid vapor into liquid working fluid in the vapor cooler of the fourth device.

[0060] The pipe body 66 is immersed in the liquid working fluid 30 in the liquid reservoir 38 within the pressure vessel 22. Since the pressure p E ≈ 0.2 bar at the outlet of the expansion machine 16 is slightly higher than the hydrostatic pressure of the liquid working fluid 30, the working fluid vapor 35 can enter the liquid working fluid 30, forming small vapor bubbles 47 that rise into the saturated steam reservoir 34 and transfer heat to the liquid working fluid 30 through contact with it. The technical purpose of the micro-openings 68 formed in the pipe body 66 is that the working fluid vapor from the expansion machine 16 can pass through them, finely dispersed as vapor bubbles 47, into the liquid working fluid 30 in the liquid reservoir 38, thus enabling heat transfer to the liquid working fluid 30 in the liquid reservoir 38 via a large surface area.

[0061] In summary, the following preferred features are particularly noteworthy: A device 10, 10', 10", 10‴ for generating electrical or mechanical energy includes a residual current (RC) system. The RC system can, in particular, be designed as an organic residual cycle (ORC) system. The RC system has a working fluid circuit 12 for a working fluid, in which a working fluid evaporator 14, an expansion machine 16 operated with working fluid vapor from the working fluid evaporator 14, and a condenser 18 are arranged. Between the expansion machine 16 and the condenser 18, a vapor cooler 20, 20', 20", 20'' is located in the working fluid circuit 12. The vapor cooler 20, 20', 20", 20‴ serves to convert working fluid vapor flowing from the expansion machine 16 into saturated working fluid steam 36, which the condenser 18 receives in order to produce liquid working fluid 30. form.When operating a working fluid circuit 12, in which liquid working fluid 30 is evaporated and supplied as a vaporous working fluid to an expansion machine 16, in which the working fluid is expanded, the working fluid expanded in the expansion machine 16 is first converted into working fluid saturated steam 36 by cooling in a steam cooler 20, 20', 20", 20‴ and only then into liquid working fluid 30 by condensation in a condenser 18, which is then evaporated again and made available to the expansion machine 16 for expansion. Reference symbol list

[0062] 10; 10', 10", 10‴Device for generating electrical or mechanical energy 12Working medium circuit 14Working medium evaporator 16Expansion machine 18Condenser 20, 20', 20", 20‴Steam cooler 22Pressure vessel 24First connection 26Second connection 27Feed line 28Third connection 30Liquid working medium 32Feed pump 34Saturated steam reservoir 35Working medium steam 36Working medium saturated steam 37Partition 38Liquid reservoir 39Fill level 40, 40', 40", 40‴Device for introducing working medium steam into liquid working medium 42Pipe 44Inlet opening 46Outlet opening 47Steam bladder 48Pressure vessel register section 49Return line 50 Fourth connection 52 Cooling water line 54 Heat transfer fluid 56 Steam channel 58 Porous body 60 Distributor body 62 Opening 64 Arrow 66 Pipe body 68 Micro-opening

Claims

1. Device (10, 10', 10", 10‴) for generating electrical or mechanical energy having an RC system, in particular having an ORC system, which has a working fluid cycle (12) for a working fluid in which a working fluid evaporator (14) as well as an expansion machine (16), operated with working fluid vapor from the working fluid evaporator (14), and a condenser (18) are arranged, comprising a vapor cooler (20, 20', 20", 20‴) arranged in the working fluid cycle (12), between the expansion machine (16) and the condenser (18), and used to convert working fluid vapor flowing from the expansion machine (16) into working fluid saturated vapor (36) that the condenser (18) receives in order to form liquid working fluid (30) therefrom.

2. Device according to claim 1, comprising a return line (49) designed to return liquid working fluid (30) formed in the condenser (18) to the vapor cooler (20, 20', 20", 20‴).

3. Device according to claim 1 or 2, wherein the vapor cooler (20, 20', 20", 20‴) has a pressure vessel (22) having a first port (24) for feeding working fluid vapor from the expansion machine (16) to the pressure vessel (22), a second port (26), communicating with the condenser (18), for supplying working fluid saturated vapor (36) to the condenser (18), and a third port (28) for discharging liquid working fluid (30) that the working fluid evaporator (14) receives.

4. Device according to claim 3, wherein a saturated vapor reservoir (34) for receiving working fluid saturated vapor (36) and a liquid reservoir (38), communicating with this reservoir, for receiving liquid working fluid (30) are present in the pressure vessel (22).

5. Device according to claim 4, wherein the first port (24) for feeding in working fluid vapor (35) from the expansion machine (16) is connected to the liquid reservoir (38) by an apparatus (20, 20', 20", 20‴) for introducing the working fluid vapor from the expansion machine (16) into liquid working fluid (30).

6. Device according to claim 5, wherein the apparatus (20, 20', 20", 20‴) for introducing the working fluid vapor (35) from the expansion machine (16) into liquid working fluid (30) is designed to introduce the working fluid vapor from the expansion machine (16) into the liquid working fluid (30) below a fill level (39) of the liquid working fluid (30) in the liquid reservoir (38).

7. Device according to claim 5 or 6, wherein the apparatus (20) for introducing the working fluid vapor (35) from the expansion machine (16) into liquid working fluid (30) with the liquid reservoir (38) has a plurality of pipes (42) which project into the liquid reservoir (38) and each have an inlet opening (44) for working fluid vapor (35) from the expansion machine (16) and an outlet opening (46) for the influx of working fluid vapor (35) into liquid working fluid (30) in the liquid reservoir (38).

8. Device according to claim 7, wherein the pipes (42) are guided through the saturated vapor reservoir (34).

9. Device according to claim 8 or claim 7, comprising a pressure vessel register portion (48) communicating with the liquid reservoir (38) via the pipes (42).

10. Device according to claim 5 or 6, wherein the first port (24) for feeding in working fluid vapor (35) from the expansion machine (16) communicates with the liquid reservoir (38) through a vapor channel (56) formed in a porous body (58), or the first port for feeding in working fluid vapor (35) from the expansion machine (16) communicates with the liquid reservoir (38) through a vapor channel (56) that opens into a stack of plates with vapor channels formed therein, or that the first port (24) for feeding in working fluid vapor (35) from the expansion machine (16) communicates with the liquid reservoir (38) through a vapor channel (58), wherein the vapor channel (58) runs in a pipe body (66), closed at one end, with micro-openings (68).

11. Device according to any of claims 4 to 10, wherein the pressure vessel (22) has a fourth port (50) for introducing liquid working fluid (30) from the condenser (18) into the liquid reservoir (38).

12. Device according to any of claims 1 to 11, wherein the condenser (18) is designed as a plate heat exchanger that extracts heat from the working fluid saturated vapor (36) and transfers it to cooling water flowing through the plate heat exchanger and / or comprising a feed pump (32) for conveying liquid working fluid (30) from the pressure vessel (22) into the working fluid evaporator (14).

13. Device according to any of claims 1 to 12, wherein the working fluid evaporator (14) is designed as a heat exchanger that transfers heat from a fluid (54) flowing through the heat exchanger to the working fluid (30).

14. Device according to claim 13, wherein the fluid (54) is a gaseous fluid, in particular flue gas.

15. Method for operating a working fluid cycle (12) in which liquid working fluid (30) is evaporated and fed as vaporous working fluid to an expansion machine (16) in which the working fluid is expanded, wherein the working fluid expanded in the expansion machine (16) is first converted into working fluid saturated vapor (36) by cooling in a vapor cooler (20, 20', 20", 20‴) and only then is converted into liquid working fluid (30) by condensing in a condenser (18), which liquid working fluid is evaporated again and provided to the expansion machine (16) for expansion.

16. Method according to claim 15, wherein the liquid working fluid (30) formed in the condenser (18) is returned to the vapor cooler (20, 20', 20", 20‴).

17. Method according to claim 15 or 16, wherein working fluid vapor from the expansion machine (16) is introduced into the liquid working fluid (30) below a fill level of the liquid working fluid (30) in a liquid reservoir (38) of the pressure vessel (22).

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