US20160298499A1 - An energy converter - Google Patents
An energy converter Download PDFInfo
- Publication number
- US20160298499A1 US20160298499A1 US15/038,517 US201415038517A US2016298499A1 US 20160298499 A1 US20160298499 A1 US 20160298499A1 US 201415038517 A US201415038517 A US 201415038517A US 2016298499 A1 US2016298499 A1 US 2016298499A1
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- United States
- Prior art keywords
- energy converter
- feed pump
- working fluid
- machine
- electrical
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Classifications
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
- F01D—NON-POSITIVE DISPLACEMENT MACHINES OR ENGINES, e.g. STEAM TURBINES
- F01D1/00—Non-positive-displacement machines or engines, e.g. steam turbines
- F01D1/02—Non-positive-displacement machines or engines, e.g. steam turbines with stationary working-fluid guiding means and bladed or like rotor, e.g. multi-bladed impulse steam turbines
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
- F01K—STEAM ENGINE PLANTS; STEAM ACCUMULATORS; ENGINE PLANTS NOT OTHERWISE PROVIDED FOR; ENGINES USING SPECIAL WORKING FLUIDS OR CYCLES
- F01K25/00—Plants or engines characterised by use of special working fluids, not otherwise provided for; Plants operating in closed cycles and not otherwise provided for
- F01K25/08—Plants or engines characterised by use of special working fluids, not otherwise provided for; Plants operating in closed cycles and not otherwise provided for using special vapours
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
- F01D—NON-POSITIVE DISPLACEMENT MACHINES OR ENGINES, e.g. STEAM TURBINES
- F01D15/00—Adaptations of machines or engines for special use; Combinations of engines with devices driven thereby
- F01D15/08—Adaptations for driving, or combinations with, pumps
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
- F01D—NON-POSITIVE DISPLACEMENT MACHINES OR ENGINES, e.g. STEAM TURBINES
- F01D15/00—Adaptations of machines or engines for special use; Combinations of engines with devices driven thereby
- F01D15/10—Adaptations for driving, or combinations with, electric generators
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
- F01D—NON-POSITIVE DISPLACEMENT MACHINES OR ENGINES, e.g. STEAM TURBINES
- F01D25/00—Component parts, details, or accessories, not provided for in, or of interest apart from, other groups
- F01D25/08—Cooling; Heating; Heat-insulation
- F01D25/12—Cooling
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
- F01D—NON-POSITIVE DISPLACEMENT MACHINES OR ENGINES, e.g. STEAM TURBINES
- F01D5/00—Blades; Blade-carrying members; Heating, heat-insulating, cooling or antivibration means on the blades or the members
- F01D5/02—Blade-carrying members, e.g. rotors
- F01D5/04—Blade-carrying members, e.g. rotors for radial-flow machines or engines
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
- F01K—STEAM ENGINE PLANTS; STEAM ACCUMULATORS; ENGINE PLANTS NOT OTHERWISE PROVIDED FOR; ENGINES USING SPECIAL WORKING FLUIDS OR CYCLES
- F01K11/00—Plants characterised by the engines being structurally combined with boilers or condensers
- F01K11/02—Plants characterised by the engines being structurally combined with boilers or condensers the engines being turbines
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
- F01K—STEAM ENGINE PLANTS; STEAM ACCUMULATORS; ENGINE PLANTS NOT OTHERWISE PROVIDED FOR; ENGINES USING SPECIAL WORKING FLUIDS OR CYCLES
- F01K15/00—Adaptations of plants for special use
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
- F01K—STEAM ENGINE PLANTS; STEAM ACCUMULATORS; ENGINE PLANTS NOT OTHERWISE PROVIDED FOR; ENGINES USING SPECIAL WORKING FLUIDS OR CYCLES
- F01K9/00—Plants characterised by condensers arranged or modified to co-operate with the engines
- F01K9/003—Plants characterised by condensers arranged or modified to co-operate with the engines condenser cooling circuits
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
- F01K—STEAM ENGINE PLANTS; STEAM ACCUMULATORS; ENGINE PLANTS NOT OTHERWISE PROVIDED FOR; ENGINES USING SPECIAL WORKING FLUIDS OR CYCLES
- F01K9/00—Plants characterised by condensers arranged or modified to co-operate with the engines
- F01K9/02—Arrangements or modifications of condensate or air pumps
Definitions
- the invention relates generally to energy converters for converting thermal energy into electricity. More particularly, the invention relates to an energy converter that can be based on, for example but not necessarily, the Organic Rankine Cycle “ORC”.
- Small-size energy converters which can be based on for example the Organic Rankine Cycle “ORC” process, can be used for converting the thermal energy of waste heat into electricity which is easily used for different purposes.
- the waste heat can be received from various heat-producing processes or heat-producing machines, e.g. a combustion engine or a gas turbine, where, due to the temperature of the waste heat and/or due to the circumstances of the environment, the waste heat cannot be used as such or by means of conventional heat exchangers or corresponding means.
- the ORC process is an applicable technique for this kind of energy conversion.
- the heat of vaporization of organic working fluid is low in relation to e.g. the heat of evaporation of water, and its fall of specific enthalpy in the turbine is small and the mass flow rate in relation to the output is high, wherein it is possible to reach high turbine efficiency even in a range of small capacity.
- the utilization of high-speed technology, wherein the turbine is directly coupled with a generator rotating at the same speed and thus producing high-frequency current, has made it possible to further simplify the process in a way that e.g. a separate reduction gear required by conventional processes is not needed.
- the high speed technology makes it possible to provide a hermetic process, which means significant savings in the operational expenses.
- Publication EP0090022 describes an energy converter that comprises a vaporizer, i.e. a boiler, a radial turbine, a condenser, a feed pump, and a high-speed generator.
- the energy converter may further comprise a recuperator and a pre-feed pump.
- the thermal energy supplied to the vaporizer is arranged to maintain the Organic Rankine Cycle process driving the generator and thus producing electricity.
- the radial turbine and the feed pump are directly connected to the rotor of the generator.
- the rotor is rotatably carried with gas-dynamic bearings utilizing the organic working fluid in gaseous form.
- the back-surface of the radial turbine is arranged to serve as one abutment surface of a gas-static thrust bearing.
- the feed pump connected to the rotor of the generator requires pre-supply pressure in order to avoid cavitation on the vanes of the impeller of the feed pump. Therefore, an energy converter of the kind described above is, in many cases, provided with a pre-supply pump for generating the required pre-supply pressure for the feed pump. However, also the pre-feed pump may require pre-supply pressure in order to avoid cavitation on the vanes of its impeller.
- the pre-feed pump can be placed at a lower level than the condenser tank so as to have a sufficient hydrostatic pressure ⁇ g ⁇ h at the suction side of the pre-feed pump, where ⁇ is the density of the working fluid in condensed form, g is the acceleration of the gravity, and h is the height difference between the pre-feed pump and the liquid surface in the condenser tank.
- ⁇ is the density of the working fluid in condensed form
- g is the acceleration of the gravity
- h is the height difference between the pre-feed pump and the liquid surface in the condenser tank.
- Energy converters of the kind described above are, however, not free from challenges.
- One of the challenges is related to the mechanical dimensions of the energy converters which, in order to be suitable for different operation sites, should be as small as possible.
- Especially the total height of an energy converter installation can be a critical dimension in conjunction with many energy converters in which the pre-feed pump is placed at a lower level than the condenser tank.
- An energy converter that can be based on, for example but not necessarily, the Organic Rankine Cycle “ORC” process.
- An energy converter according to the invention comprises:
- the ejector-pump facilitates generating sufficient pre-supply pressure for the pre-feed pump.
- the pre-feed pump can be located, with respect to the condenser tank, higher than in cases where the pre-supply pressure of the pre-feed pump is based merely on the hydrostatic pressure. Therefore, the total height of an energy converter installation can be lower than in the cases where the pre-supply pressure of the pre-feed pump is based merely on the hydrostatic pressure.
- the pre-feed pump is operated by the motor capable of running independently of the operation of the electrical turbo-machine and the ejector-pump is operated by a part of the output flow of the pre-feed pump
- the required pre-supply pressure can be generated for the pre-feed pump during also a starting phase and other situations in which the electrical turbo-machine and thereby the feed pump are not fully operating.
- an ejector pump is very simply without any moving parts, and very inexpensive to manufacture.
- FIG. 1 a shows a schematic block diagram of an energy converter according to an exemplifying embodiment of the invention
- FIG. 1 b shows a section view of an electrical turbo-machine of the energy converter illustrated in FIG. 1 a.
- FIG. 1 a shows a schematic block diagram of an energy converter according to an exemplifying embodiment of the invention.
- the energy converter is advantageously an Organic Rankine Cycle “ORC” energy converter that uses suitable organic fluid as the working fluid.
- the organic fluid can be, for example but not necessarily, one of the siloxanes. It is also possible that the energy converter uses suitable non-organic fluid as the working fluid.
- the energy converter comprises an electrical turbo-machine 101 for converting energy contained by vaporized working fluid into electrical energy.
- the electrical turbo-machine 101 is advantageously a high-speed machine whose rotational speed can be as high as e.g. 10000 . . . 60000 rpm.
- FIG. 1 b shows a section view of the electrical turbo-machine 101 .
- the section plane is parallel with the yz-plane of a coordinate system 199 shown in FIG. 1 b .
- the electrical energy outputted by the electrical turbo-machine 101 is supplied to a power grid 119 with the aid of a frequency converter 118 .
- a vaporizer, i.e. a boiler, 115 which vaporizes the working fluid can be operated by e.g.
- the energy converter comprises a piping interface 116 a , 116 b for connecting to the vaporizer 115 which is not an integral part of the energy converter but an external element.
- the vaporizer is an integral part of the energy converter.
- the exemplifying energy converter illustrated in FIGS. 1 a and 1 b comprises a condenser 104 for condensing the vaporized working fluid outputted by the electrical turbo-machine 101 .
- An energy converter according to another exemplifying embodiment of the invention comprises a piping interface for connecting to an external condenser element that is not an integral part of the energy converter.
- the energy converter comprises a feed pump 105 for pumping the condensed working fluid to the vaporizer 115 .
- the feed pump 105 is operated by the electrical turbo-machine 101 .
- the energy converter comprises pre-feed pump 106 for pumping the condensed working fluid to the suction side of the feed pump 105 .
- the pre-feed pump 106 is operated by a motor 107 that is capable of running independently of the operation of the electrical turbo-machine 101 .
- the motor 107 can be for example an electrical motor.
- the electrical motor can be such that the air-gap between the rotor and the stator of the motor is filled with the working fluid, and also bearings are exposed to the working fluid.
- the motor 107 and the pre-supply pump 106 can be arranged to form a hermetic entity without a need for seals between the parts constituting the motor 107 and the parts constituting the pre-supply pump 106 .
- the energy converter comprises an ejector-pump 108 for pumping the condensed working fluid to the suction side of the pre-feed pump 106 .
- the ejector-pump 108 is operated by a part of the output flow of the pre-feed pump 106 .
- the ejector-pump 108 facilitates generating the required pre-supply pressure for the pre-feed pump 106 .
- the pre-feed pump can be located, with respect to a condenser tank 129 , higher than in cases where the pre-supply pressure of the pre-feed pump is based merely on the hydrostatic pressure. Therefore, the height of the energy converter can be smaller.
- the pre-feed pump 106 is operated by the motor 107 capable of running independently of the operation of the electrical turbo-machine 101 and the ejector-pump 108 is operated by a part of the output flow of the pre-feed pump 106 , the required pre-supply pressure can be generated for the pre-feed pump 106 during also a starting phase and other situations in which the electrical turbo-machine 101 and thereby the feed pump 105 are not fully operating.
- the pre-feed pump 106 can be started by increasing gradually the rotational speed. Then the pressure produced by the ejector-pump 108 increases in same phase as the feeding pressure required by the pre-feed pump, and danger of cavitation during pre-feed pump start is avoided.
- the energy converter may comprise a controller 133 that is arranged to start the pre-feed pump so that the rotational speed of the pre-feed pump is increased gradually according to a pre-determined speed profile.
- the controller 133 can be implemented for example with the controller elements of the frequency converter 118 or the controller 133 can be a separate element.
- the exemplifying energy converter illustrated in FIGS. 1 a and 1 b comprises the condenser tank 129 .
- An energy converter according to another exemplifying embodiment of the invention comprises a piping interface for connecting to an external condenser tank that is not an integral part of the energy converter.
- the electrical turbo-machine 101 comprises a generator section 103 and a turbine section 102 .
- the feed pump 105 for pumping the working fluid to the vaporizer 115 is integrated with the electrical turbo-machine 101 .
- the generator section comprises a stator 121 and a rotor 110 for magnetically interacting with the stator.
- the stator comprises a stator core structure 122 having a plurality of stator teeth and stator slots, and a stator winding 123 having a plurality of stator coils.
- the stator core structure 122 is preferably made of steel sheets that are electrically insulated from each other and that are stacked in the direction parallel with the axial direction of the rotor 110 .
- the axial direction is parallel with the z-direction of the coordinate system 199 .
- the rotor 110 of the generator section may comprise permanent magnets for producing a magnetic flux penetrating the air-gap between the rotor and the stator.
- the generator section is capable of operating as a permanent magnet synchronous generator “PMSG”.
- the rotor 110 comprises electrically conductive structures so that the generator section is capable of operating as an asynchronous generator.
- the rotor 110 is rotatably carried by bearings 127 and 128 .
- the bearings 125 and 126 are lubricated with the working fluid of the thermodynamic energy conversion process. As illustrated in FIG.
- the energy converter comprises ducts 114 for conducting the working fluid to bearings of the electrical turbo-machine so as to lubricate the bearings of the electrical turbo-machine with the working fluid.
- the ducts 114 can be connected to the delivery side of the pre-feed pump 106 so that the bearings can be lubricated also in situations where the feed pump 105 is not operating. In some cases it is however also possible that the ducts 114 are connected to the delivery side of the feed pump 105 .
- the turbine section of the electrical turbo-machine 101 comprises a diffuser 124 , a stator nozzle ring 125 , and an impeller 126 suitable for operating as a turbine for rotating the rotor 110 of the generator section.
- the feed pump comprises an impeller 109 for pumping the working fluid.
- both of the impellers 126 and 109 are directly coupled to the rotor 110 of the generator section.
- the stator nozzle ring 125 , the impeller 126 , and the diffuser 124 are advantageously suitable for operating as a radial turbine stage whose degree of reaction is less than 50% e.g. 30%.
- the axial height of the vanes of the impeller 126 can be increased and, as a corollary, the ratio of the axial clearance to the axial height of the impeller vanes can be made smaller, and thus the efficiency can be improved.
- the degree of reaction or reaction ratio is defined as the ratio of the static enthalpy drop in the impeller 126 to the static enthalpy drop in the whole turbine stage.
- the impeller 109 of the feed pump can be, for example, a straight vane radial impeller of a “Barske”-type partial emission pump.
- the impeller of the feed pump can be provided with a screw-type inducer 111 for reducing the risk of cavitation on the vanes of the impeller 109 , and thereby to reduce the required pre-supply pressure of the feed pump.
- the electrical turbo-machine 101 may further comprise an impeller 130 for generating cooling flow inside the frame of the generator section.
- the exemplifying energy converter illustrated in FIGS. 1 a and 1 b comprises a recuperator 117 for increasing the efficiency of the energy conversion.
- the recuperator is a heat exchanging element arranged to transfer heat energy from the vaporized working fluid outputted by the electrical turbo-machine 101 to the condensed working fluid outputted by the feed pump 105 and being supplied to the vaporizer 115 .
- the exemplifying energy converter illustrated in FIGS. 1 a and 1 b further comprises first cooling ducts 112 for conducting cooling fluid, e.g. water, to and from the electrical turbo-machine 101 so as to cool the generator section, and second cooling ducts 113 for conducting cooling fluid to and from the condenser 104 .
- the first and second cooling ducts constitute mutually parallel flowing paths for the cooling fluid.
- the first and second cooling ducts can be connected to an external cooling fluid circulation system with the aid of a piping interface 131 a , 131 b .
- this is only an example of a cooling arrangement of the electrical turbo-machine 101 . It may be cooled also otherwise.
- the exemplifying energy converter illustrated in FIGS. 1 a and 1 b comprises a turbine valve 132 and possibly other control and/or safety instrumentation.
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- Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- General Engineering & Computer Science (AREA)
- Chemical & Material Sciences (AREA)
- Combustion & Propulsion (AREA)
- Connection Of Motors, Electrical Generators, Mechanical Devices, And The Like (AREA)
- Engine Equipment That Uses Special Cycles (AREA)
Abstract
An energy converter includes an electrical turbo-machine (101) for converting energy contained by vaporized working fluid into electrical energy, a feed pump (105) for pumping the working fluid in a condensed form to a vaporizer (115), a pre-feed pump (106) for pumping the condensed working fluid to the suction side of the feed pump, and an ejector-pump (108) for pumping the condensed working fluid to the suction side of the pre-feed pump. The energy converter can be based on for example the Organic Rankine Cycle. The feed pump is operated by the electrical turbo-machine, the pre-feed pump is operated by a separate motor (107), and the ejector-pump is operated by a part of the output flow of the pre-feed pump. The ejector-pump facilitates generating sufficient pre-supply pressure for the pre-feed pump during also a starting phase and other situations where the electrical turbo-machine and feed pump are not fully operating.
Description
- The invention relates generally to energy converters for converting thermal energy into electricity. More particularly, the invention relates to an energy converter that can be based on, for example but not necessarily, the Organic Rankine Cycle “ORC”.
- Small-size energy converters, which can be based on for example the Organic Rankine Cycle “ORC” process, can be used for converting the thermal energy of waste heat into electricity which is easily used for different purposes. The waste heat can be received from various heat-producing processes or heat-producing machines, e.g. a combustion engine or a gas turbine, where, due to the temperature of the waste heat and/or due to the circumstances of the environment, the waste heat cannot be used as such or by means of conventional heat exchangers or corresponding means.
- It can be shown thermodynamically that the ORC process is an applicable technique for this kind of energy conversion. The heat of vaporization of organic working fluid is low in relation to e.g. the heat of evaporation of water, and its fall of specific enthalpy in the turbine is small and the mass flow rate in relation to the output is high, wherein it is possible to reach high turbine efficiency even in a range of small capacity. The utilization of high-speed technology, wherein the turbine is directly coupled with a generator rotating at the same speed and thus producing high-frequency current, has made it possible to further simplify the process in a way that e.g. a separate reduction gear required by conventional processes is not needed. Also, the high speed technology makes it possible to provide a hermetic process, which means significant savings in the operational expenses.
- Publication EP0090022 describes an energy converter that comprises a vaporizer, i.e. a boiler, a radial turbine, a condenser, a feed pump, and a high-speed generator. The energy converter may further comprise a recuperator and a pre-feed pump. The thermal energy supplied to the vaporizer is arranged to maintain the Organic Rankine Cycle process driving the generator and thus producing electricity. The radial turbine and the feed pump are directly connected to the rotor of the generator. The rotor is rotatably carried with gas-dynamic bearings utilizing the organic working fluid in gaseous form. The back-surface of the radial turbine is arranged to serve as one abutment surface of a gas-static thrust bearing.
- The feed pump connected to the rotor of the generator requires pre-supply pressure in order to avoid cavitation on the vanes of the impeller of the feed pump. Therefore, an energy converter of the kind described above is, in many cases, provided with a pre-supply pump for generating the required pre-supply pressure for the feed pump. However, also the pre-feed pump may require pre-supply pressure in order to avoid cavitation on the vanes of its impeller. In order to produce sufficient pre-supply pressure for the pre-feed pump, the pre-feed pump can be placed at a lower level than the condenser tank so as to have a sufficient hydrostatic pressure ρ×g×h at the suction side of the pre-feed pump, where ρ is the density of the working fluid in condensed form, g is the acceleration of the gravity, and h is the height difference between the pre-feed pump and the liquid surface in the condenser tank. An inherent advantage of this arrangement where the pre-feed pump is placed at a lower level than the condenser tank is that the pre-supply pressure, i.e. the hydrostatic pressure, is generated for the pre-feed pump irrespective of the operation of the energy converter. Therefore, there is sufficient pre-supply pressure for the pre-feed pump during also a starting phase and other situations in which the turbo-generator and thereby the feed pump are not fully operating.
- Energy converters of the kind described above are, however, not free from challenges. One of the challenges is related to the mechanical dimensions of the energy converters which, in order to be suitable for different operation sites, should be as small as possible. Especially the total height of an energy converter installation can be a critical dimension in conjunction with many energy converters in which the pre-feed pump is placed at a lower level than the condenser tank.
- The following presents a simplified summary in order to provide a basic understanding of some embodiments of the invention. The summary is not an extensive overview of the invention. It is neither intended to identify key or critical elements of the invention nor to delineate the scope of the invention. The following summary merely presents some concepts of the invention in a simplified form as a prelude to a more detailed description of exemplifying embodiments of the invention.
- In accordance with the invention, there is provided a new energy converter that can be based on, for example but not necessarily, the Organic Rankine Cycle “ORC” process. An energy converter according to the invention comprises:
-
- an electrical turbo-machine for converting energy contained by vaporized working fluid into electrical energy, the electrical turbo-machine comprising a turbine section and a generator section,
- a feed pump for pumping the working fluid in a condensed form to a vaporizer, the feed pump being arranged to be operated by the electrical turbo-machine,
- a pre-feed pump for pumping the working fluid in the condensed form to the suction side of the feed pump, the pre-feed pump being arranged to be operated by a motor capable of running independently of operation of the electrical turbo-machine, and
- an ejector-pump for pumping the working fluid in the condensed form to the suction side of the pre-feed pump, the ejector-pump being arranged to be operated by a part of the output flow of the pre-feed pump.
- The ejector-pump facilitates generating sufficient pre-supply pressure for the pre-feed pump. Thus, the pre-feed pump can be located, with respect to the condenser tank, higher than in cases where the pre-supply pressure of the pre-feed pump is based merely on the hydrostatic pressure. Therefore, the total height of an energy converter installation can be lower than in the cases where the pre-supply pressure of the pre-feed pump is based merely on the hydrostatic pressure. As the pre-feed pump is operated by the motor capable of running independently of the operation of the electrical turbo-machine and the ejector-pump is operated by a part of the output flow of the pre-feed pump, the required pre-supply pressure can be generated for the pre-feed pump during also a starting phase and other situations in which the electrical turbo-machine and thereby the feed pump are not fully operating. Also, it should be noted that an ejector pump is very simply without any moving parts, and very inexpensive to manufacture.
- A number of non-limiting and exemplifying embodiments of the invention are described in accompanied dependent claims.
- Various exemplifying embodiments of the invention both as to constructions and to methods of operation, together with additional objects and advantages thereof, will be best understood from the following description of specific exemplifying embodiments when read in connection with the accompanying drawings.
- The verbs “to comprise” and “to include” are used in this document as open limitations that neither exclude nor require the existence of also un-recited features. The features recited in dependent claims are mutually freely combinable unless otherwise explicitly stated. Furthermore, it is to be understood that the use of “a” or “an”, i.e. a singular form, throughout this document does as such not exclude a plurality.
- The exemplifying embodiments of the invention and their advantages are explained in greater detail below in the sense of examples and with reference to the accompanying drawings, in which:
-
FIG. 1a shows a schematic block diagram of an energy converter according to an exemplifying embodiment of the invention, and -
FIG. 1b shows a section view of an electrical turbo-machine of the energy converter illustrated inFIG. 1 a. -
FIG. 1a shows a schematic block diagram of an energy converter according to an exemplifying embodiment of the invention. The energy converter is advantageously an Organic Rankine Cycle “ORC” energy converter that uses suitable organic fluid as the working fluid. The organic fluid can be, for example but not necessarily, one of the siloxanes. It is also possible that the energy converter uses suitable non-organic fluid as the working fluid. - The energy converter comprises an electrical turbo-
machine 101 for converting energy contained by vaporized working fluid into electrical energy. The electrical turbo-machine 101 is advantageously a high-speed machine whose rotational speed can be as high as e.g. 10000 . . . 60000 rpm.FIG. 1b shows a section view of the electrical turbo-machine 101. The section plane is parallel with the yz-plane of acoordinate system 199 shown inFIG. 1b . The electrical energy outputted by the electrical turbo-machine 101 is supplied to apower grid 119 with the aid of afrequency converter 118. A vaporizer, i.e. a boiler, 115 which vaporizes the working fluid can be operated by e.g.waste heat 120 received from a heat-producing process or a heat-producing machine, e.g. a combustion engine. In the exemplifying case illustrated inFIGS. 1a and 1b , the energy converter comprises apiping interface vaporizer 115 which is not an integral part of the energy converter but an external element. In an energy converter according to another exemplifying embodiment of the invention, the vaporizer is an integral part of the energy converter. - The exemplifying energy converter illustrated in
FIGS. 1a and 1b comprises acondenser 104 for condensing the vaporized working fluid outputted by the electrical turbo-machine 101. An energy converter according to another exemplifying embodiment of the invention comprises a piping interface for connecting to an external condenser element that is not an integral part of the energy converter. The energy converter comprises afeed pump 105 for pumping the condensed working fluid to thevaporizer 115. Thefeed pump 105 is operated by the electrical turbo-machine 101. The energy converter comprisespre-feed pump 106 for pumping the condensed working fluid to the suction side of thefeed pump 105. Thepre-feed pump 106 is operated by amotor 107 that is capable of running independently of the operation of the electrical turbo-machine 101. Themotor 107 can be for example an electrical motor. The electrical motor can be such that the air-gap between the rotor and the stator of the motor is filled with the working fluid, and also bearings are exposed to the working fluid. In this case, themotor 107 and thepre-supply pump 106 can be arranged to form a hermetic entity without a need for seals between the parts constituting themotor 107 and the parts constituting thepre-supply pump 106. The energy converter comprises an ejector-pump 108 for pumping the condensed working fluid to the suction side of thepre-feed pump 106. The ejector-pump 108 is operated by a part of the output flow of thepre-feed pump 106. The ejector-pump 108 facilitates generating the required pre-supply pressure for thepre-feed pump 106. Thus, the pre-feed pump can be located, with respect to acondenser tank 129, higher than in cases where the pre-supply pressure of the pre-feed pump is based merely on the hydrostatic pressure. Therefore, the height of the energy converter can be smaller. As thepre-feed pump 106 is operated by themotor 107 capable of running independently of the operation of the electrical turbo-machine 101 and the ejector-pump 108 is operated by a part of the output flow of thepre-feed pump 106, the required pre-supply pressure can be generated for thepre-feed pump 106 during also a starting phase and other situations in which the electrical turbo-machine 101 and thereby thefeed pump 105 are not fully operating. Thepre-feed pump 106 can be started by increasing gradually the rotational speed. Then the pressure produced by the ejector-pump 108 increases in same phase as the feeding pressure required by the pre-feed pump, and danger of cavitation during pre-feed pump start is avoided. The energy converter may comprise acontroller 133 that is arranged to start the pre-feed pump so that the rotational speed of the pre-feed pump is increased gradually according to a pre-determined speed profile. Thecontroller 133 can be implemented for example with the controller elements of thefrequency converter 118 or thecontroller 133 can be a separate element. The exemplifying energy converter illustrated inFIGS. 1a and 1b comprises thecondenser tank 129. An energy converter according to another exemplifying embodiment of the invention comprises a piping interface for connecting to an external condenser tank that is not an integral part of the energy converter. - The electrical turbo-
machine 101 comprises agenerator section 103 and aturbine section 102. Thefeed pump 105 for pumping the working fluid to thevaporizer 115 is integrated with the electrical turbo-machine 101. As illustrated inFIG. 1b , the generator section comprises astator 121 and arotor 110 for magnetically interacting with the stator. The stator comprises astator core structure 122 having a plurality of stator teeth and stator slots, and a stator winding 123 having a plurality of stator coils. Thestator core structure 122 is preferably made of steel sheets that are electrically insulated from each other and that are stacked in the direction parallel with the axial direction of therotor 110. The axial direction is parallel with the z-direction of the coordinatesystem 199. Therotor 110 of the generator section may comprise permanent magnets for producing a magnetic flux penetrating the air-gap between the rotor and the stator. In this case, the generator section is capable of operating as a permanent magnet synchronous generator “PMSG”. It is also possible that therotor 110 comprises electrically conductive structures so that the generator section is capable of operating as an asynchronous generator. Therotor 110 is rotatably carried bybearings FIGS. 1a and 1b , thebearings FIG. 1a , the energy converter comprisesducts 114 for conducting the working fluid to bearings of the electrical turbo-machine so as to lubricate the bearings of the electrical turbo-machine with the working fluid. Theducts 114 can be connected to the delivery side of thepre-feed pump 106 so that the bearings can be lubricated also in situations where thefeed pump 105 is not operating. In some cases it is however also possible that theducts 114 are connected to the delivery side of thefeed pump 105. - As illustrated in
FIG. 1b , the turbine section of the electrical turbo-machine 101 comprises adiffuser 124, astator nozzle ring 125, and animpeller 126 suitable for operating as a turbine for rotating therotor 110 of the generator section. The feed pump comprises animpeller 109 for pumping the working fluid. In the exemplifying energy converter illustrated inFIGS. 1a and 1b , both of theimpellers rotor 110 of the generator section. Thestator nozzle ring 125, theimpeller 126, and thediffuser 124 are advantageously suitable for operating as a radial turbine stage whose degree of reaction is less than 50% e.g. 30%. Thus, the axial height of the vanes of theimpeller 126 can be increased and, as a corollary, the ratio of the axial clearance to the axial height of the impeller vanes can be made smaller, and thus the efficiency can be improved. The degree of reaction or reaction ratio is defined as the ratio of the static enthalpy drop in theimpeller 126 to the static enthalpy drop in the whole turbine stage. Theimpeller 109 of the feed pump can be, for example, a straight vane radial impeller of a “Barske”-type partial emission pump. The impeller of the feed pump can be provided with a screw-type inducer 111 for reducing the risk of cavitation on the vanes of theimpeller 109, and thereby to reduce the required pre-supply pressure of the feed pump. The electrical turbo-machine 101 may further comprise animpeller 130 for generating cooling flow inside the frame of the generator section. - The exemplifying energy converter illustrated in
FIGS. 1a and 1b comprises arecuperator 117 for increasing the efficiency of the energy conversion. The recuperator is a heat exchanging element arranged to transfer heat energy from the vaporized working fluid outputted by the electrical turbo-machine 101 to the condensed working fluid outputted by thefeed pump 105 and being supplied to thevaporizer 115. - The exemplifying energy converter illustrated in
FIGS. 1a and 1b further comprisesfirst cooling ducts 112 for conducting cooling fluid, e.g. water, to and from the electrical turbo-machine 101 so as to cool the generator section, andsecond cooling ducts 113 for conducting cooling fluid to and from thecondenser 104. As illustrated inFIG. 1a , the first and second cooling ducts constitute mutually parallel flowing paths for the cooling fluid. The first and second cooling ducts can be connected to an external cooling fluid circulation system with the aid of apiping interface machine 101. It may be cooled also otherwise. - Furthermore, the exemplifying energy converter illustrated in
FIGS. 1a and 1b comprises aturbine valve 132 and possibly other control and/or safety instrumentation. - The specific examples provided in the description given above should not be construed as limiting. Therefore, the invention is not limited merely to the embodiments described above.
Claims (17)
1-14. (canceled)
15. An energy converter comprising:
an electrical turbo-machine for converting energy contained by vaporized working fluid into electrical energy, the electrical turbo-machine comprising a turbine section and a generator section,
a feed pump for pumping the working fluid in a condensed form to a vaporizer, the feed pump being arranged to be operated by the electrical turbo-machine,
a pre-feed pump for pumping the working fluid in the condensed form to a suction side of the feed pump, the pre-feed pump being arranged to be operated by a motor capable of running independently of operation of the electrical turbo-machine, and
an ejector-pump for pumping the working fluid in the condensed form to a suction side of the pre-feed pump, wherein the ejector-pump is arranged to be operated by a part of an output flow of the pre-feed pump.
16. An energy converter according to claim 15 , wherein the feed-pump comprises an impeller connected directly to an end of a rotor of the generator section.
17. An energy converter according to claim 16 , wherein the impeller of the feed pump is provided with a screw-type inducer for reducing a risk of cavitation on vanes of the impeller of the feed pump.
18. An energy converter according to claim 15 , wherein the motor for operating the pre-feed pump is an electrical motor.
19. An energy converter according to claim 15 , wherein the energy converter comprises:
first cooling ducts for conducting cooling fluid to and from the generator section so as to cool the generator section, and
second cooling ducts for conducting the cooling fluid to and from a condenser for condensing the vaporized working fluid outputted by the electrical turbo-machine, the first and second cooling ducts constituting mutually parallel flowing paths for the cooling fluid.
20. An energy converter according to claim 15 , wherein the energy converter comprises ducts for conducting the working fluid to bearings of the electrical turbo-machine so as to lubricate the bearings of the electrical turbo-machine with the working fluid, the ducts being connected to a delivery side of the pre-feed pump.
21. An energy converter according to claim 15 , wherein the energy converter comprises ducts for conducting the working fluid to bearings of the electrical turbo-machine so as to lubricate the bearings of the electrical turbo-machine with the working fluid, the ducts being connected to a delivery side of the feed pump.
22. An energy converter according to claim 15 , wherein the energy converter further comprises the vaporizer.
23. An energy converter according to claim 15 , wherein the energy converter comprises a piping interface for connecting to the vaporizer.
24. An energy converter according to claim 15 , wherein the energy converter further comprises a recuperator for transferring heat energy from the vaporized working fluid outputted by the electrical turbo-machine to the condensed working fluid outputted by the feed pump.
25. An energy converter according to claim 15 , wherein the functional elements further comprise a frequency converter for supplying the electrical energy outputted by the electrical turbo-machine to an external electrical system.
26. An energy converter according to claim 15 , wherein the energy converter further comprises a condenser for condensing the vaporized working fluid outputted by the electrical turbo-machine.
27. An energy converter according to claim 15 , wherein the energy converter further comprises a controller arranged to start the pre-feed pump so that the rotational speed of the pre-feed pump is increased gradually according to a pre-determined speed profile.
28. An energy converter according to claim 15 , wherein the working fluid is organic working fluid.
29. An energy converter according to claim 19 , wherein the energy converter comprises ducts for conducting the working fluid to bearings of the electrical turbo-machine so as to lubricate the bearings of the electrical turbo-machine with the working fluid, the ducts being connected to a delivery side of the pre-feed pump.
30. An energy converter according to claim 19 , wherein the energy converter comprises ducts for conducting the working fluid to bearings of the electrical turbo-machine so as to lubricate the bearings of the electrical turbo-machine with the working fluid, the ducts being connected to a delivery side of the feed pump.
Applications Claiming Priority (3)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
FI20136171A FI125429B (en) | 2013-11-22 | 2013-11-22 | energy converter |
FI20136171 | 2013-11-22 | ||
PCT/FI2014/050824 WO2015075301A1 (en) | 2013-11-22 | 2014-11-04 | An energy converter |
Publications (1)
Publication Number | Publication Date |
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US20160298499A1 true US20160298499A1 (en) | 2016-10-13 |
Family
ID=51900468
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
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US15/038,517 Abandoned US20160298499A1 (en) | 2013-11-22 | 2014-11-04 | An energy converter |
Country Status (4)
Country | Link |
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US (1) | US20160298499A1 (en) |
EP (1) | EP3084150A1 (en) |
FI (1) | FI125429B (en) |
WO (1) | WO2015075301A1 (en) |
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN113431650A (en) * | 2021-06-28 | 2021-09-24 | 西安热工研究院有限公司 | System and method for improving load response rate of thermal power generating unit |
Families Citing this family (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US9863266B2 (en) | 2015-11-19 | 2018-01-09 | Borgwarner Inc. | Waste heat recovery system for a power source |
FR3064726A1 (en) * | 2017-03-29 | 2018-10-05 | Aqylon | THERMODYNAMIC SYSTEM, PARTICULARLY IMPLEMENTING A RANKINE THERMODYNAMIC CYCLE |
WO2018184770A1 (en) | 2017-04-07 | 2018-10-11 | Huntsman Advanced Materials (Switzerland) Gmbh | Colorant mixtures |
Citations (6)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US4564084A (en) * | 1984-03-22 | 1986-01-14 | Elliott Turbomachinery Co., Inc. | Method and apparatus for controlling the temperature of oil in an overhead tank |
US4593527A (en) * | 1984-01-13 | 1986-06-10 | Kabushiki Kaisha Toshiba | Power plant |
US5570579A (en) * | 1991-07-11 | 1996-11-05 | High Speed Tech Oy Ltd. | Method and apparatus for improving the efficiency of a small-size power plant based on the ORC process |
US6494042B2 (en) * | 2001-02-12 | 2002-12-17 | Ormat Industries Ltd. | Method of and apparatus for producing uninterruptible power |
US8215114B2 (en) * | 2005-06-10 | 2012-07-10 | City University | Expander lubrication in vapour power systems |
US8664785B2 (en) * | 2010-09-13 | 2014-03-04 | Ebara International Corporation | Power recovery system using a rankine power cycle incorporating a two-phase liquid-vapor expander with electric generator |
Family Cites Families (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
FI66234C (en) | 1981-10-13 | 1984-09-10 | Jaakko Larjola | ENERGIOMVANDLARE |
JPH0828805A (en) * | 1994-07-19 | 1996-02-02 | Toshiba Corp | Apparatus and method for supplying water to boiler |
EP1004751B1 (en) * | 1998-11-25 | 2003-02-26 | Alstom Power Generation AG | Steam power plant in open air arrangement |
-
2013
- 2013-11-22 FI FI20136171A patent/FI125429B/en not_active IP Right Cessation
-
2014
- 2014-11-04 WO PCT/FI2014/050824 patent/WO2015075301A1/en active Application Filing
- 2014-11-04 US US15/038,517 patent/US20160298499A1/en not_active Abandoned
- 2014-11-04 EP EP14798910.7A patent/EP3084150A1/en not_active Withdrawn
Patent Citations (6)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US4593527A (en) * | 1984-01-13 | 1986-06-10 | Kabushiki Kaisha Toshiba | Power plant |
US4564084A (en) * | 1984-03-22 | 1986-01-14 | Elliott Turbomachinery Co., Inc. | Method and apparatus for controlling the temperature of oil in an overhead tank |
US5570579A (en) * | 1991-07-11 | 1996-11-05 | High Speed Tech Oy Ltd. | Method and apparatus for improving the efficiency of a small-size power plant based on the ORC process |
US6494042B2 (en) * | 2001-02-12 | 2002-12-17 | Ormat Industries Ltd. | Method of and apparatus for producing uninterruptible power |
US8215114B2 (en) * | 2005-06-10 | 2012-07-10 | City University | Expander lubrication in vapour power systems |
US8664785B2 (en) * | 2010-09-13 | 2014-03-04 | Ebara International Corporation | Power recovery system using a rankine power cycle incorporating a two-phase liquid-vapor expander with electric generator |
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN113431650A (en) * | 2021-06-28 | 2021-09-24 | 西安热工研究院有限公司 | System and method for improving load response rate of thermal power generating unit |
Also Published As
Publication number | Publication date |
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EP3084150A1 (en) | 2016-10-26 |
FI20136171A (en) | 2015-05-23 |
WO2015075301A1 (en) | 2015-05-28 |
FI125429B (en) | 2015-10-15 |
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