Classifications

• • 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
  • F01K21/00—Steam engine plants not otherwise provided for
• • 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
  • F01D17/00—Regulating or controlling by varying flow
  • F01D17/10—Final actuators
  • F01D17/12—Final actuators arranged in stator parts
  • F01D17/18—Final actuators arranged in stator parts varying effective number of nozzles or guide conduits, e.g. sequentially operable valves for steam turbines
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
  • F01N—GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
  • F01N5/00—Exhaust or silencing apparatus combined or associated with devices profiting by exhaust energy
  • F01N5/02—Exhaust or silencing apparatus combined or associated with devices profiting by exhaust energy the devices using heat
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F05—INDEXING SCHEMES RELATING TO ENGINES OR PUMPS IN VARIOUS SUBCLASSES OF CLASSES F01-F04
  • F05D—INDEXING SCHEME FOR ASPECTS RELATING TO NON-POSITIVE-DISPLACEMENT MACHINES OR ENGINES, GAS-TURBINES OR JET-PROPULSION PLANTS
  • F05D2220/00—Application
  • F05D2220/30—Application in turbines
  • F05D2220/31—Application in turbines in steam turbines
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F05—INDEXING SCHEMES RELATING TO ENGINES OR PUMPS IN VARIOUS SUBCLASSES OF CLASSES F01-F04
  • F05D—INDEXING SCHEME FOR ASPECTS RELATING TO NON-POSITIVE-DISPLACEMENT MACHINES OR ENGINES, GAS-TURBINES OR JET-PROPULSION PLANTS
  • F05D2220/00—Application
  • F05D2220/60—Application making use of surplus or waste energy
  • F05D2220/62—Application making use of surplus or waste energy with energy recovery turbines
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F05—INDEXING SCHEMES RELATING TO ENGINES OR PUMPS IN VARIOUS SUBCLASSES OF CLASSES F01-F04
  • F05D—INDEXING SCHEME FOR ASPECTS RELATING TO NON-POSITIVE-DISPLACEMENT MACHINES OR ENGINES, GAS-TURBINES OR JET-PROPULSION PLANTS
  • F05D2270/00—Control
  • F05D2270/01—Purpose of the control system
  • F05D2270/16—Purpose of the control system to control water or steam injection

Definitions

• the invention relates to a steam turbine, in particular for waste heat utilization of an internal combustion engine, according to the preamble of claim 1.
• the steam turbine according to the invention with the features of the independent claim has the advantage that a particularly large power spectrum can be covered by the steam turbine through the use of nozzles that are designed for different load points and are independent of each other and can be switched off.
• the different designs of the nozzles are easy and advantageous due to their geometry, the area ratio between the narrowest nozzle cross-section and outlet cross section, the approved flow cross-section and / or the angle of inclination of the nozzle to the impeller specified.
• high load points of the internal combustion engine only the nozzle with the design for high load points can be switched on, while the other nozzle is switched off.
• Next load points of the internal combustion engine can be covered by a combination of both nozzles. The low number of nozzles can save costs in the design and at the same time a broad performance spectrum of the internal combustion engine can be covered.
• vapor nozzles are used for the acceleration of the vapor in the stator, since the steam can be accelerated from supersonic to supersonic through these nozzles, and a particularly high output of the steam turbine can be achieved by the high speeds.
• the use of partially pressurized steam turbines is advantageous because the diameter of the impeller can be increased by the partial application and can be avoided by small and difficult to implement sizes of turbines.
• a further advantage results when the nozzles of the steam turbine are switched on and off via a switching device of control valves or pinholes, as a result, a variety of possible nozzle combinations is available.
• a switching device which is controlled by a voltage applied to the stator pressure difference, since the disconnection and connection of the nozzle can be optimally adapted to the adjacent boundary conditions. It is advisable that the switching device is actuated via a servomotor, in particular a stepper motor, since this is a simple and cost-effective implementation possibility.
• a nozzle as a nozzle bypass, which directs the steam without accelerating on the impeller to slowly flow through the impeller during warm-up or to produce no power in Schubbertrieb the internal combustion engine.
• a bypass implemented in this form is much less expensive than a bypass that bypasses the steam at the steam turbine.
• the slow flow through the turbine during warm-up can prevent low-quality steam from causing damage to the impellers by recondensation.
• freezing of the impellers may be eliminated by the warm steam prior to starting the steam turbine.
• the nozzle which serves as a nozzle bypass
• the direction of the steam jet changed so that no resulting torque is generated on the impeller.
• a power output of the steam turbine is avoided in overrun operation.
• FIG. 1 shows a steam turbine in a schematic representation according to a first embodiment
• FIG. 2 a perspective view of a Laval nozzle
• Figure 3 shows a steam turbine in a schematic representation according to a second embodiment
• FIG. 4 shows a steam turbine with a line circuit in a schematic representation.
• FIGS 1 and 3 show a steam turbine 10 in a schematic representation with an impeller 26, a stator 20 and a switching device 28.
• Diffuser 20 at least two nozzles 22 are arranged, which convert the potential energy of the steam into kinetic energy in the stator 20.
• the nozzles 22 are arranged in the stator 20 parallel to each other, so that the steam in a same plane for all nozzles 22, perpendicular to the main stream tion direction, enters and leaves the nozzles 22 in another plane, which is perpendicular to the main flow direction.
• the nozzles 22 are arranged in a circular manner in the stator 20. It can be a fully pressurized steam turbine 10, in which the nozzles are arranged around the entire stator 20 around or a teilbeetzmannte steam turbine 10, wherein the nozzles 22 fill only parts or a sector of the circle of the stator 20.
• the nozzles 22 are designed for different load points of the impeller 26, wherein at least one of the nozzles 22 is designed for a high load point of the impeller 26 and at least one of the nozzles 22 is designed for a low load point of the impeller 26.
• the different design of the nozzles 22 are determined mainly by their geometry, the released flow cross section, the area ratio between the narrowest nozzle cross section and outlet cross section and / or the inclination angle of the nozzle 22 to the impeller 26.
• the design of the individual nozzles 22 is determined on the basis of the operating conditions occurring, such as mass flow, temperature and pressure conditions. These operating conditions vary particularly strongly in a steam turbine which is used for waste heat utilization of an internal combustion engine.
• the nozzles 22 are preferably Laval nozzles 24, as shown in Figure 2, and direct the steam accelerated to the impeller 26 of the steam turbine 10.
• the Laval nozzles 24 are formed as rectangular channels with a converging and diverging cross-sectional profile. Due to their special shape Laval nozzles 24 are able to accelerate gas flows from subsonic to supersonic.
• nozzles 22 may be provided for other load points of the impeller 26 or a plurality of nozzles 22 may be provided for the same load point of the impeller 26.
• the nozzles 22 may be arranged in nozzle groups or individually in the stator 20.
• the stator 20 is preceded by a switching device 28, which connects the nozzle 22 stator 20 independently of each other and off. Through the Heidelbergvorrich tion 28 each nozzle 22 can be opened alone, while the other nozzles 22 are closed or multiple nozzles 22 are opened simultaneously. If the nozzles 22 are arranged in nozzle groups, whole nozzle groups can also be opened or closed via the switching device 28.
• the switching device 28 may consist of control valves 30 or from a pinhole and may be arranged in front of or behind the stator 20.
• the switching device 28 can be regulated via a voltage applied to the stator 20 pressure difference. Depending on the applied pressure difference, one or more nozzles 22 adapted to this boundary condition are released, while other nozzles 22 are closed.
• the switching device 28 can be actuated via a servomotor, in particular a stepping motor.
• the actuation of the switching device 28 can be active by a servomotor or passively by the use of the applied pressure difference.
• FIG. 3 A further embodiment is shown in Figure 3, in which in addition to the nozzles 22, which serve to accelerate the steam to the impeller 26, a further nozzle is provided, which serves as a nozzle bypass 32.
• This nozzle bypass 32 is not designed as a Laval nozzle 24, since the nozzle bypass 32 is intended to direct the steam unaccelerated to the impeller 26.
• the nozzle bypass 32 has in comparison to the other nozzles 22 a large flow cross-section, so that the pressure in the steam turbine 10 upstream high-pressure part degrades very quickly and the steam reaches only very small flow velocities when entering the impeller 26. Due to the low flow rates, no appreciable power output is achieved in the impeller 26.
• the power of the impeller 26 can be further reduced when the nozzle bypass 32 changes the direction of the steam jet emerging from the nozzle bypass 32 so that no resulting torque is generated. This can be effected by an impingement of the impeller 26 in the axial direction or in the reverse direction of rotation.
• the steam turbine 10 may also be formed as a multi-stage steam turbine 10, in which a plurality of stages of guide wheels 20 and wheels 26 are arranged one behind the other. In each of the turbine stages, the nozzles 22 of the stator 20 can be switched on and off according to the two embodiments of FIG. 1 and FIG. 3 via a switching device 28.
• a switching device 28 for controlling the nozzles 22 may be located only in the first stage of the steam turbine 10 of stator 20 and impeller 26, which is located directly behind the steam source.
• the nozzles 22 of the downstream stages of stator 20 and impeller 26 may be arranged so that they correspond to their positioning with the nozzles 22 of the first stage.
• the steam jet of the nozzle 22 released in the first stage should only enter the corresponding second stage nozzle 22.
• the corresponding nozzles 22 are designed so that they achieve optimum efficiency in the adjacent boundary conditions.
• the steam turbine 10 is particularly suitable for waste heat utilization for applications in motor vehicles. However, the steam turbine 10 of the invention is also suitable for other applications.
• FIG. 4 shows a steam turbine 10 according to one of the previous embodiments in a line circuit 4 for waste heat utilization of an internal combustion engine 2.
• a heat exchanger 8 In the line circuit 4, in which a working medium circulates, are a heat exchanger 8, a
• Condenser 12 a feed pump 6 and the steam turbine 10 is arranged.
• the internal combustion engine 2 burns fuel to generate mechanical energy.
• the resulting exhaust gases are discharged via an exhaust system in which an exhaust gas catalyst can be arranged.
• a line section of the exhaust system is passed through a heat exchanger 8. Heat energy from the exhaust gases or the exhaust gas recirculation is discharged in the heat exchanger 8 to the working fluid, so that the working fluid can be evaporated in the heat exchanger 8 and overheated.
• the heat exchanger 8 of the line circuit 4 is connected via a line to the steam turbine 10. Via the line, the vaporized working fluid flows to the steam turbine 10 and drives it.
• the steam turbine 10 has an output shaft 1 1, via which the steam turbine 10 is connected to a load.
• a working medium water can be used or another liquid that meets the thermodynamic requirements.
• the working medium undergoes thermodynamic changes of state as it flows through the line circuit 4.
• the working medium is brought by the feed pump 6 to the pressure level for the evaporation.
• the heat energy of the exhaust gas is discharged via the heat exchanger 8 to the working medium.
• the working medium is isobarically evaporated and then overheated.
• the steam is relaxed adiabatically in the steam turbine 10. This mechanical energy is obtained and transmitted to the shaft 1 1.
• the working medium is then cooled in the condenser 12, liquefied and fed back to the feed pump 6.
• the heat exchanger 8 produces the steam that is available to the steam turbine 10.
• the steam turbine 10 must work with other boundary conditions (amount of steam, temperature, pressure) and adjust its load points accordingly. This is done by the switching on and off of the nozzles 22 in the stator 20 of the steam turbine 10, which correspond to the different load points of the internal combustion engine 2.

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• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• General Engineering & Computer Science (AREA)
• Chemical & Material Sciences (AREA)
• Combustion & Propulsion (AREA)
• Engine Equipment That Uses Special Cycles (AREA)

Applications Claiming Priority (2)

Publications (1)

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Family Applications (1)

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• 2010
  • 2010-10-13 DE DE102010042412A patent/DE102010042412A1/de not_active Withdrawn
• 2011
  • 2011-09-19 EP EP11757648.8A patent/EP2627869A1/de not_active Withdrawn
  • 2011-09-19 WO PCT/EP2011/066218 patent/WO2012048987A1/de active Application Filing
  • 2011-09-19 CN CN201180049042.9A patent/CN103154439B/zh not_active Expired - Fee Related
  • 2011-09-19 US US13/879,564 patent/US20130205783A1/en not_active Abandoned

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