EP3704356A1

EP3704356A1 - Method and device for converting thermal energy into mechanical or electrical energy

Info

Publication number: EP3704356A1
Application number: EP19730251.6A
Authority: EP
Inventors: Jürgen KRAIL; Georg Beckmann
Original assignee: Fachhochschule Burgenland GmbH
Current assignee: Fachhochschule Burgenland GmbH
Priority date: 2018-05-29
Filing date: 2019-05-28
Publication date: 2020-09-09
Also published as: AT521050A4; WO2019227117A1; AT521050B1

Abstract

The invention is intended to increase the energy efficiency and cost efficiency of Clausius-Rankine cycles, in particular for utilizing low-temperature heat, and to avoid the disadvantages of the processes that have become known. The heat-absorbing part of the cycle is provided with branches (24), which branch off flows from the main flow of the medium used in the cycle, connect them to mixers (31), in which the branched-off flows are mixed with the exhaust steam from exhaust-steam lines (20) of the expansion engines or the turbines (19), and these mixed steam flows are reintroduced into the cycle by way of cold exhaust-steam lines (21). A significant increase in the energy efficiency is obtained when using media of the "dry" fluid class in the cycle, by virtue of the fact that the flows mixed in evaporate completely, in return for which there is overheating in the main flow, and a greater flow of steam is available to the medium-pressure turbine (19MD) for expansion, which leads to extra power at the turbines of 10 to 15%.

Description

Method and device for converting thermal into mechanical or electrical energy

The invention relates to a method and a device for increasing the energy efficiency in Clausius-Rankine cycles. In this thermodynamic cycle according to the invention, heat is efficiently converted into mechanical or electrical energy using circulating media.

For the use of heat sources, especially with low temperature levels, such. B. in (industrial) waste heat, in geothermal energy and solar thermal use, also circulation media are used, which do not consist of water / steam; These are z. As ethanol and organic

Circulation media (used in the so-called Organic Rankine Cycle "ORC" processes) .These possible alternatives

Circulation media usually have a higher vapor pressure and a lower enthalpy of vaporization than water / steam and could better use the available heat source; In many cases, these circulation media are guided in hermetically closed circuits. Most of these

Circulation media belong to the "dry" or "drying"

Fluid class in which the saturated steam does not expand in an expansion in the wet steam area, but removed from the saturated steam curve and overheats (dries); this circumstance is generally considered to be an advantage, which certainly applies to the operation of the expansion machine, but may be detrimental to the energy efficiency of the overall process, as explained below.

Fig. 1 shows a corresponding circuit diagram, based on an ORC process, according to the prior art, which, for example, for use in geothermal

Power plants is explained; here is the geothermal energy Heat source and the geothermal water of the heat carrier, with which the heat is transported to the cycle. The

geothermal water ("thermal water") from the

Production bore (1) passes through a filter (2) and a thermal water line (3) in the steam generator (4), where this gives off its heat and is cooled; the cooled

Thermal water reaches via a return line (5)

Return pump (6), which the cooled thermal water to

Promotes injection hole (7).

Looking at the ORC process, the condensate from the exhaust steam condenser (8), which has almost ambient temperature, via the condensate line (9) to the condensate pump (10) out; this conveys the condensate via the feed line (11)

usually to the recuperator (12); the preheated there

Condensate is through the boiler feed line (13) the

Steam generator (4) supplied, which in the subcritical operation, a preheater (14) and, connected via a connecting line (15), an evaporator (16), optionally with a subsequent superheater, having the

Live steam generated. The connecting channel (17) connects on the side of the thermal water, the evaporator (16) and the preheater (14). The steam produced in the steam generator (4), saturated or at most slightly overheated, is a

Main steam line (18) of the expansion machine or the turbine (19) supplied, where it expands; the turbine exhaust steam, which is still a considerable one for dry circulation media

Overheating (with respect to the temperature and the heat content) in itself, is derived via the exhaust steam line (20), cooled in the recuperator (12) to just below its saturation temperature and passes through the cold exhaust steam line (21) in the

Abdampfkondensator (8), where this is deposited as condensate; this closes the cycle. The turbine shaft (22) of the turbine (19) gives off mechanical energy or drives the generator (23) to generate electricity.

Because of the preheating of the circulation medium in the recuperator (12) of the steam generator can cool the available thermal water only to a limited extent, which is disadvantageous to the

Energy efficiency of the overall process. Leaving the recuperator (12) aside, it would be possible to extract an additional amount of heat from the thermal water, which increases the power to be dissipated at the exhaust-steam condenser (8), so that no increase in efficiency can be achieved.

The example shows the application in geothermal power plants, but can, in an analogous manner instead of the thermal water, other (liquid, vapor and gaseous) heat transfer medium, for. As well as hot water streams from large condensate networks, or hot heat transfer oil flows from heat recovery systems, exhaust, hot air or compressed air streams to use for

Power generation to be supplied.

The patent DE 10 2012 220 188 B4 shows z. B. how a symbiotic ORC process for using the

Intercooling in compressor stations can be used to drive the performance of such compressor stations

by reducing the turbine of the ORC process, e.g. B. via a drive shaft, is coupled to the compressor station to reduce the required drive power of this compressor station; the proposed ORC process, apart from its very ambitious integration into the

Gas compressor station, but still corresponds to the prior art. There was no lack of further proposals to improve the attractiveness and efficiency of the ORC process. Focusing on the aspect of cooling the available heat source and its heat transfer medium as far as possible (and beneficial), two main strategies are known: a. The two-pressure or multi-pressure process: The patent DE 11 2010 003 230 B4 discloses a thermodynamic system in which two waste heat streams with different waste heat temperatures not in a single impression boiler (ie in the impression process), but in separate high pressure (HD) - and low pressure ( ND) - boiling kettles are used and made of a single

organic fluid-derived HD and LP vapors are expanded in sitting on a common shaft turbines. It would be conceivable, even a single heat flow (eg thermal water) to flow first through the HD and then through the LP boiler, whereby the desired further cooling of the

Thermal water, associated with an increase in electricity yield, would be achieved. However, this increased energy efficiency would be estimated by the factor of 1.23 higher

Compared to the cost of equipment, since instead of a cycle with a total output of the impression process, two cycles would be required, each with half the total output, which would add up to an equipment cost degression exponent of 0.7 (see also PERRY's Chemical Engineering Handbook) 2 * (1/2) ^L 0.7 = 1.23, ie the investment costs are 23% higher than in the comparison case of an imprint process. b. The injection of liquid circulation medium or of completely preheated circulating medium directly into the turbine or into the expansion machine is disclosed in US Pat. No. 5,555,731 or in International Publication Number WO 2017 / 008972A1. Both proposals would be a new concept of

Turbine or the expansion machine require; about the Availability and application of such a turbine or

Expansion machine currently has no information, so this strategy only as a state of knowledge

quantify and not as common practice. Whether the short residence time in the turbine or in the expansion machine, in the range of one-hundredth of a second, is even sufficient to completely vaporize the injected circulating medium remains to be seen.

All under points a. and b. patents or

Patents disclose thermodynamic systems in the subcritical process management, so that in these

Patent proposals on the additional potential of

Increased efficiency through a supercritical process management is omitted. In contrast, the subject invention proposal is also suitable for a supercritical

Litigation, as in the following descriptions

is executed, so the potential of the supercritical

Process management efficiency-enhancing and can be used additionally.

The object of the invention is to provide the energy and cost efficiency of the Rankine cycle cycle,

in particular for the mentioned use of Ab- and

Low-temperature heating, to increase and still avoid the mentioned disadvantages of the known processes.

The invention describes a method for increasing the

Energy efficiency in Clausius-Rankine cycle processes for the use of heat from heat sources, especially at low levels

Temperature levels, which are available to the cycle

is placed and converted there into mechanical or electrical energy, in which a condensate of a

Circulation medium via a condensate line of a condensate pump supplied and is pressurized by this, this

Circulation medium evaporated in a steam generator with heat absorption from the heat source and, where appropriate, superheated and this steam via a main steam line a

Expansion machine or turbine for generating the mechanical energy is supplied, there expands and condenses the exhaust steam of the expansion machine or turbine with the release of residual heat outside the cycle, characterized

characterized in that in the heat-absorbing portion of the

Circuit process, between a condensate line (9) and a main steam line (18), at least one branch (24) is provided, which is a current from the main stream of

Circulating medium branches, this via an inlet (26) to a connecting line (25), optionally including

Feed pumps (27), heat exchangers (28) and fittings (29), and via a drain (30), which in a Zumischeintritt (32) of a mixer (31) opens, in which the branched stream with the exhaust steam from an exhaust steam line ( 20) one

Expansion machine or a turbine (19), provided via a steam supply line (33), is mixed and this mixed stream via a steam outlet (35) and a cold exhaust steam line (21) in the cycle back and

is continued (Fig. 2, Fig. 8).

Furthermore, the method is characterized in that the circulating medium is water or steam or carbon dioxide or else another inorganic chemical compound; that the circulating medium ethanol or another

organic chemical compound is; that the circulation medium is a synthetic circulatory medium; that the circulation medium is a mixture consisting of two or more components; that the circulation medium is a mixture with a lowered freezing point, ie an antifreeze mixture, such. Water and glycol or ethanol; that the circulation medium is a zeotropic mixture which distils apart during heat uptake; that the circulation medium is a sorptive mixture which desorbs the volatile component during heat absorption and absorbs it during mixing; that the circulating medium belongs to the dry class, which in an expansion away from the wet steam area; that the circulation medium is operated subcritically in a steam generator and the steam generator (4) heating surfaces for

Preheating (14), for evaporation (16) and optionally for overheating of the circulation medium (Fig. 2, Fig. 8); the circulation medium is operated supercritically in the steam generator and the steam generator (4) has heating surfaces for preheating (14) and for reheating (16) the circulating medium (FIG. 2); that a feed line (11) to a boiler feed line (13), optionally via a valve and or a branch (24a) closes (Figure 8, Fig. 2); the number of branches (24) is greater than the number of mixers (31) (Figures 2, 8); in that at least one mixer, preferably the medium-pressure mixer (31MD), has two or more admixed inlets, preferably the two admixed inlets (32 b and 32 c) (FIGS. 2, 8); in that the mixer (31) has a nozzle or a nozzle group (34) with which the branched stream is introduced into the interior of the mixer (FIG. 4); in that the mixer (31) has filling bodies (36), which via a trickling device (37) with the branched-off stream

be sprinkled (Figure 5); in that the mixer (31) has a liquid separator (40)

is connected downstream (Figure 6); that the medium-pressure mixer (31MD), optionally with the downstream liquid separator (40), a medium-pressure turbine (19MD) is connected downstream (Fig. 2, Fig. 8); the low-pressure mixer (31ND) is followed by an exhaust-steam condenser (8) (FIGS. 2, 8); that the heat exchanger (28ND) in the connection line (25ND) to the low pressure mixer (31ND) the heat outside of the

Circuit process outputs (Fig. 2, Fig. 8); that the heat exchanger (28ND) in the connection line (25ND) to the low pressure mixer (31ND) the overheating and the

Dissipates condensation heat of the exhaust steam of the exhaust steam line (20ND), so that the desuperheating and condensation of the exhaust steam takes place in the low-pressure mixer (31ND) and out of the cold

Evaporator line (21ND) condensate comes and this condensate is led directly into the condensate line (9) (FIG. 2, FIG.

that a branch (24b and / or 24c) before the end of a

Preheater (14), which by reaching the

least temperature difference between the heat carrier and the circulating medium is characterized (Fig. 2, Fig. 7, Fig. 8); that branches (24b and / or 24c) are made by distributors and / or collectors (43) of the preheater (14), its heating surface packs (42) or its connecting lines (Figure 7); that branches (24b and / or 24c) from the mantle space of

Preheater (14), in which the heat transfer medium is guided on the pipe side, take place (FIG. 8); in that within the connecting sections (25a, 25b, 25c or 25HD) the respective heat exchangers (28a, 28b, 28c or 28HD) are heated by a further, external heat source; the heat exchanger (28) of the connecting section (25) is arranged before, after or parallel to the preheater (14) and is heated by the flow or partial flow of the heat carrier (FIG. 9); in that the heat exchanger (28) is heated by a branched-off flow of the heat carrier by removing this branched off stream from the heat carrier side in the region of the preheater (14) via a bypass branch (44) and optionally via a bypass flap (45) and after the heat release a

Bypass return line (46) is supplied to the main stream (Fig. that the throughput and the state of the sequence (30) of the

Connection path (25) by the feed pump (27), or the heat exchanger (28), or the armature (29) is controlled such that the state in the cold exhaust duct (21) comes to rest near the saturation line (Figure 3). the throughput of the inflow to the connecting line (25) is regulated via the bypass branch (44) and the bypass control flap (45) such that the temperature of the circulating medium in the bypass return line (46) and in a return line (5) of the heat carrier is almost the same ( Fig. 10); that the branch (24 b and / or 24 c) takes place at the location where the preheat temperature at this branch is equal to or higher than the steam saturation temperature in the exhaust steam line (20MD).

The invention describes an energy conversion device for increasing the energy efficiency in Clausius-Rankine cycle processes for the use of heat from heat sources,

especially with low temperature levels, which the

Circular process is made available and converted there into mechanical or electrical energy, in which a condensate of a circulating medium via a condensate line fed to a condensate pump and is pressurized by this, this cycle medium in a steam generator below

Heat absorption from the heat source evaporated and optionally superheated and this steam is supplied via a steam line expansion machine or turbine for generating the mechanical energy, there expands and condenses the exhaust steam of the expansion machine or turbine with the release of residual heat outside the cycle, characterized

characterized in that in the heat-absorbing part of

Energy conversion device, between the condensate line (9) and the main steam line (18), at least one branch (24) is provided, which is a current from the main stream of the

Circulation medium branches, this via an inlet (26) to the connecting line (25), optionally containing feed pumps (27), heat exchangers (28) and fittings (29), and via a drain (30) in a Zumischeintritt (32) of

Mixer (31) opens, which the branched stream with the exhaust steam from the exhaust steam line (20) of the expansion machine or the turbine (19), provided via the steam supply line (33), mixed and this mixed stream over the

Steam outlet (35) and the cold exhaust pipe (21) in

Circuit process is continued and continued (Fig. 2, Fig. 8).

Furthermore, the energy conversion device is thereby

characterized in that the device comprises a steam generator (4) with heating surfaces for preheating (14), for evaporation (16) and optionally for overheating of the circulation medium and the

Circulation medium is operated subcritically in the steam generator (Fig. 2, Fig. 8); the device has a steam generator (4) with heating surfaces for preheating (14) and for reheating (16) the circulating medium and the circulating medium in the steam generator is operated supercritically (FIG. 2); that the feed line (11) to the boiler feed line (13), optionally via a valve and or a branch (24a) closes (Figure 8, Fig. 2); the number of branches (24) is greater than the number of mixers (31) (Figures 2, 8); in that at least one mixer, preferably the medium-pressure mixer (31MD), has two or more admixed inlets, preferably the two admixed inlets (32 b and 32 c) (FIGS. 2, 8); in that the mixer (31) has a nozzle or a nozzle group (34) with which the branched stream is introduced into the interior of the mixer (FIG. 4); in that the mixer (31) has filling bodies (36) which, via the sprinkling device (37), are connected to the diverted stream

be sprinkled (Figure 5); in that the mixer (31) has a liquid separator (40)

is connected downstream (Figure 6); that the medium-pressure mixer (31MD), optionally with the downstream liquid separator (40), a medium-pressure turbine (19MD) is connected downstream (Fig. 2, Fig. 8); that the low-pressure mixer (31ND) downstream of the exhaust steam condenser (8) (Fig. 2, Fig. 8); that the heat exchanger (28ND) in the connection line (25ND) to the low pressure mixer (31ND) the heat outside of the

a branch (24b and / or 24c) before the end of the

Preheater (14), which by reaching the

Preheater (14), in which the heat transfer medium is guided on the pipe side, take place (FIG. 8); in that within the connecting sections (25a, 25b, 25c or 25HD) the respective heat exchangers (28a, 28b, 28c or 28HD) are heated by a further, external heat source; the heat exchanger (28) of the connecting section (25) is arranged before, after or parallel to the preheater (14) and is heated by the flow or partial flow of the heat carrier (FIG. 9); that the heat exchanger (28) is heated by a branched-off flow of the heat carrier, by the branched off current in the region of the preheater (14) from the heat carrier side over the

Bypass branch (44) and optionally removed via a bypass flap (45) and after the heat transfer over the

Bypass return line (46) is supplied to the main stream (Fig. 10); that the throughput and the state of the sequence (30) of the

Connection path (25) by the feed pump (27), or the heat exchanger (28), or the armature (29) is controlled such that the state in the cold exhaust duct (21) comes to rest near the saturation line (Figure 3). the flow rate of the inflow to the connecting section (25) is regulated via the bypass branch (44) and the bypass control flap (45) such that the temperature of the circulating medium in the bypass return line (46) and in the return line (5) of the heat carrier is almost the same ( Fig. 10); that the branch (24 b and / or 24 c) takes place at the location where the preheat temperature at this branch is equal to or higher than the steam saturation temperature in the exhaust steam line (20MD).

The following drawings explain the concept of the invention:

Fig. 1 shows the known, practiced and already described prior art in ORC processes.

The invention will be explained in more detail by means of embodiments according to the following drawings:

Fig. 2 shows an exemplary, simplified

Process flow diagram.

3 shows the associated T (s) diagram.

Figures 4 to 6, for example, disclose embodiments for the mixer, and

FIGS. 7 to 10 show advantageous integrations of

Characteristics according to the invention with the generation of steam.

FIG. 8 shows an overall process flow diagram with a steam generator in which the circulating medium is guided on the shell side.

Fig. 2 shows the scheme of the invention

Circular process: the cycle according to the invention has no Recuperator, however, some components are similar to the ORC cycle process of the current state of the art. in the

heat receiving portion, between the condensate line (9) and the main steam line (18), which opens into the turbine (19), however, one, two or more branches (24) are provided which branch off streams from the main stream of the heat-absorbing cycle medium; These branched streams are via one, two or more connecting sections (25), each consisting of an inlet (26), possibly conveying pumps (27),

Heat exchangers (28) and fittings (29) and one each

Outlet (30), the exhaust steam located in the exhaust steam line (20) of a turbine (19) via one, two or more mixers (31) fed back to the main flow. The mixer (31) has

on the main flow side, a steam supply line (33) for the exhaust steam and a steam discharge line (35) for the cold exhaust steam; on the side of the branched stream, the mixer usually has a

Zumischeintritt (32), but it can also be, as shown in the case of two (32b and 32c), or there may be even more

Zumischeintritte be useful. The interconnection of the branches and connecting lines, up to or to the mixers can be done in many ways. In the case shown, in which the

Total expansion in a high-pressure turbine (19HD) and a medium-pressure turbine (19MD), a medium-pressure mixer (31MD) between the exhaust steam line (20MD) and the cold exhaust steam line (21MD) is provided. The significant increase in energy efficiency is due to the fact that the mixed branched stream completely evaporates at the expense of overheating in the main stream, and a higher vapor stream for expansion is available to the medium pressure turbine (19MD), resulting in more power at the medium pressure turbine. Turbine (19MD) leads. This effect can be increased by the

diverted stream undergoes preheating, z. B. by the local choice of the branch (24b and / or 24c) within the preheater (14). So it is possible the local choice of Branch (24b and / or 24c) to be selected so that the

Preheating temperature at this branch is less than or equal to the steam saturation temperature in the exhaust steam line (20MD). In a further increased preheating of the

branched stream, possibly also by the

Utilization of a heat exchanger (28), can take place after the throttling valve (29) or in the mixer (31) itself an additional relaxation steam generation, which can provide a further increase in energy efficiency. The cyclic process according to the invention is also suitable for supercritical process control; in this supercritical operation on the steam generator side, by the choice of a corresponding circulation medium and the steam generator pressure, the Durchlaufheizfläche (14, 15, 16) mentally in one

Divide preheater (14) and in a "reheater" (16), wherein the preheating in the preheater (14) thermodynamically ends where the temperature difference between the streams of

Heat transfer medium and the circulation medium is the lowest.

Overall, the proposed process allows through the

lower temperature in the boiler feed line and the

increased flow in the preheater a deeper cooling of the heat transfer and this gain in the heat transferred benefits the additional power of electricity. The stronger cooling of the thermal water also leads to additional advantages outside of the cycle, in the overall process of the geothermal power plant.

An additional efficiency-increasing measure is to remove the overheated exhaust steam from the exhaust steam line (20ND)

Medium pressure turbine (19MD) on a low pressure mixer (31ND) to lead, and then one

Abdampfkondensator (8), which is a capacitor with a

Heat exchanger surface is to supply. To this positive To explain the effect, one must include the design of the affected apparatus: with the proposed arrangement to avoid the poor heat transfer of the overheated

Steam to the heat exchanger surface, which only one

Thirtieth (!) Is that of the condensing vapor. Thus, not only the effort of the proposed arrangement is lower, but also the pressure drop in the apparatus, the latter being directly the thermodynamics of the cycle

improved. The resulting increase in energy efficiency of the above measures can be estimated at 10 to 15%. The desuperheating in the mixer (31ND) before the surface condenser can of course be increased and also a (partial)

Contain condensation of the circulating medium by the

Connecting piece (25ND) contains a heat exchanger (28ND), which heat (eg. To the environment or to a

Heat extraction) releases; in extreme cases, even the

downstream surface condensation in the exhaust steam condenser (8) can be dispensed with.

In a completely different application, when the heat carrier is a moist exhaust gas, for. B. from a biomass combustion is, and by the low boiler feed temperature in parts of the

Evaporator takes place on the heat carrier side an exhaust gas condensation, even more efficiency increases are possible.

For completeness, Fig. 3 shows the

inventive cycle in the T (s) diagram. This diagram shows two things:

On the one hand, it shows the thermodynamic properties of the selected cyclic medium, characterized by its

respective temperature T, on the ordinate, as a function of its specific entropy s, on the abscissa, and by its pressure p, on the corresponding isobaric (p = const.); in the Wet steam area additionally requires the parameter of the vapor wetness x, where x = 0 the boiling line and x = 1 the

Saturation line of the saturation line describes. Because the

Saturated steam line is "overhanging" and in an isentropic expansion (s = const.) The condition of the circulating medium of the saturated steam line away, that is superheated, it is in the present case and a "dry" circulating medium, such as.

Pentane.

Secondly, the drawn, clockwise curve already outlines the characteristics of the cycle, with its respective states (temperature, pressure and entropy) of the circulation medium.

For simplicity and clarity are the

Conditions around the medium pressure mixer (31MD) with only a single branch (24c) provided and shown. The branched stream from the branch (24c) passes via the inlet (26c) and the connecting line (25c) to its outlet (30c), which merges into the admixing inlet (32c); because - again simplistic - within this connection section no heat exchanger is provided, the states of

diverted stream almost unchanged.

The circulation medium of the boiler feed line (13) is preheated in the preheaters (14) up to the boiling limit, in the

Conduit (15) forwarded, evaporated in the evaporator (16) and via the main steam line (18) for

subsequent expansion provided. The high-pressure turbine (19HD) expands the live steam to the exhaust steam condition in the exhaust steam line (20MD); Since the example shown is a circulating medium of the "dry" fluid class, the steam overheats during the expansion.The overheating of the exhaust steam from the medium pressure exhaust steam line (20MD) is overheated Mitteldruck- mixer (31MD) by the controlled admixing of the branched stream of the branch (24c), which over the inlet (26c), the connecting line (25c), the outlet (30c) and the admixing inlet (32c) is reduced to the maximum extent so that the steam condition in the cold exhaust steam line (21MD) comes close to the saturated steam line.

The location of the diversion of the branch (24c) was chosen so that the preheat temperature at this junction equal to the

Steam saturation temperature in the exhaust steam line (20MD) is.

A further expansion in the medium-pressure turbine (19MD) leads to the exhaust steam condition in the low-pressure exhaust steam line (2 OND).

The low-pressure mixer (31ND) manages the desuperheating of this exhaust steam from the low-pressure exhaust steam line (20ND), also by mixing in a branched-off flow, which comes from the condensate line (9). The branched stream from the branch (24ND) passes via the inlet (26ND) of the connecting line (25ND) to its outlet (30ND), which merges into the admixing inlet (32ND); there - again simplistic - within this connecting section no heat exchanger

is provided, the states of the branched stream remain almost unchanged. The amount of branched stream is preferably controlled so that the vapor state on the cold low pressure exhaust stream (21ND) substantially

is saturated and the exhaust steam condensor (8) predominantly precipitates the saturated steam, which returns as condensate in the condensate line (9) back into the circulation.

Analogously, the branched stream can also be branched off from the feed line (11), ie after the condensate pump (10), at an increased pressure, from the branch (24a); This was not shown separately in the present diagram, since the curves and states are nearly identical to those of the illustrated diagram.

In addition to the mentioned energetic effects of diversion and mixing is still a very special advantage of

By mixing in addition to monovalent circulation media (water, organic, synthetic and other media) and Kreislaufmediums- mixtures can be used, resulting in the heat absorption

apart distill. Thus, the field of application of this technology is essential to the so-called zeotropic mixtures, extended. In addition, even absorptive working substance pairs (such as in the technology of absorption refrigeration systems) can be used, where they are then mixed by the mixture

Absorption, associated with a temperature increase, comes;

This makes the mixer between the high-pressure turbine and the medium-pressure turbine the reheater, with the known thermodynamic advantages.

The mixers (31) can be designed differently, as the following examples show:

4 shows an embodiment of the mixer (31), with a steam supply line (33) adjoining the exhaust steam line (20), and a steam outlet (35), which opens into the cold exhaust steam line (21), the branched stream being via the outlet (30) of the connecting line (25) reaches the mixing inlet (32) of the mixer and is brought there via a nozzle or a nozzle group (34) in the interior of the mixer.

Fig. 5 shows an embodiment of the mixer as a trickle, with a steam supply line (33), a Zumischeintritt (32), with

Packages (36), wherein the branched stream via a Sprinkler (37) is distributed within the distribution space (38) of the mixer (31) and the mixed stream in the

Collecting space (39) of the mixer (31) collected and on the

Steam discharge (35) is discharged.

There may be one, two or more admix entries per mixer.

As shown in FIG. 6, the actual mixer (31) can also be followed by a liquid separator (40) for reducing the wetness or for prolonging the contact time. This liquid separator can, for. B. as

Moist collecting cyclone, or as a "demister", with a wire mesh packing to catch moisture drops

be executed, with the most isolated

Liquid is discharged via a liquid drain (41) and preferably added to the main stream of the process or recycled.

The branches can also be performed differently, such. B. the high-pressure branch (24HD) shown in FIG. 2, which the steam wetness from the (wet)

Fresh steam branches off, or branches, only in the

working liquid phase (and in which the states in the

branched stream always equal the states in the main stream at the branch).

The embodiments of the branches also depend on the

Type of steam generator from. If z. B. the circulation medium on the tube inside the heating surface of the steam generator (4) and the heating surface consists of a continuous tubing string, the branches can z. B. as T or Y pipe branches, as indicated in Figure 2, executed; consists however, the heating surface of several parallel

Pipe strands, from Heizflächenpaketen (42), the beginning

Distributor and at the end of collector (43), it may be structurally advantageous to integrate the branch in the manifold or collector by these a branched stream via the inlet (26) is removed to the connecting line (25), as shown in FIG. 7 is shown.

If, in contrast to this, the heat carrier is guided on the tube side and the circulation medium on the jacket side, as shown in FIG. 8, then the branches (24b and 24c) are formed on the jacket of the preheater (14), in the form of removal nozzles. Of the

procedural information content of this diagram corresponds to that of the circuit diagram of Fig. 2, with the

Simplification that in the "only" the branches (24ND, 24b and 24c), with the associated connecting lines (25ND, 25b and 25c) are provided and shown, this diagram is in accordance with the idea according to which at least one branch, at least one Connecting pieces and

at least one mixer is provided.

In any case, the extra effort is low to the

According to the invention branches to accomplish, so it may well be useful to provide more branches than mixers in the cycle according to the invention.

Fig. 9 shows a variant, in particular to Fig. 7. It may in fact structurally and operationally advantageous if the

Heat exchanger (28) of the connecting path (25) with a

diverted stream of the heat carrier within the steam generator (4) is heated and the heat exchanger (28), from the perspective of the heat carrier, ie z. B. of thermal water, parallel to

Preheater (14), or in series with the preheater or else

between preheater parts (14a, 14b, 14c), or also into one another As shown in Fig. 9, for example, the branched stream of the circulation medium in the branch (24) before the condensate pump (10) is removed, with the feed pump (27) to the heat exchanger ( 28), and brought via a fitting (29) to the outlet (30) of the connecting section (25) .The outlet (30) of the connecting section (25) is advantageously connected to the medium-pressure mixer (31MD).

Fig. 10 shows a variant of Fig. 9, with the same

thermodynamic effect and the same invention features. Here, however, the heat exchanger (28) outside of

Steam generator (4) arranged and the heat exchanger (28) is heated via a branched stream of the heat carrier ("bypass stream"), which the steam generator (4) via a

Bypass branch (44), and possibly via a bypass control flap (45) is removed. The cooled heat transfer medium is via the bypass return line (46) possibly the main flow of the

Added heat carrier, wherein preferably the cooled branched stream and the cooled main stream have the same temperature. This variant allows a certain

Control to maximize efficiency, but it is associated with some extra effort, especially in gaseous heat transfer (exhaust gases, exhaust air, humid gas streams). Instead of heating the heat exchanger (28) via the bypass flow, the heating can also take place via a further, external heat source. Legend :

1. Production well (heat source)

2nd filter

3. Thermal water pipe or heat transfer line

4. Steam generator

5. return line

6. return pump

7. injection hole

8. Abdampfkondensator (heat sink)

9. Condensate line

10. Condensate pump

11. Feedline

12. Recuperator

13. Boiler feed line

14. Preheater

15. Connecting line (of the circulation medium) between preheater and evaporator or reheater

16. evaporator, optionally with a downstream

Superheater or reheater

17. Connecting channel (of the heat carrier) between evaporator and preheater

18. live steam line

19. Expander or turbine (for the entry pressures HD or MD)

20. exhaust steam line

21. Cold exhaust steam line

22nd turbine shaft

23. generator

24th branch

25. Link

26. Feed

27. Feed pump

28. Heat exchanger

29th fitting 30. Procedure

31. Mixer (for the printing levels HD, MD or ND)

32. Zumischeintritt

33. Steam supply

34. Nozzle or nozzle group

35. steam discharge

36. packing

37. Sprinkler device

38. distribution room

39. Collection room

40. liquid separator

41. Liquid drainage

42. heating surface package

43. Distributor or collector

44. Bypass branch

45. Bypass control flap

46. Bypass return line

HD ... high pressure (live steam pressure)

MD ... medium pressure

ND ... low pressure (exhaust pressure)

a, b, c, d ... several components with similar procedural tasks

Claims

(Patent) claims

1. A method for increasing the energy efficiency in Clausius-Rankine cycle processes for the use of heat from heat sources, especially with low temperature levels, which the

characterized in that in the heat-absorbing portion of the

is continued (Fig. 2, Fig. 8).

2. The method according to claim 1, characterized in that the

Circulation medium is water or steam or carbon dioxide or other inorganic chemical compound.

3. The method according to claim 1, characterized in that the

Circulatory medium ethanol or another organic

chemical compound is.

4. The method according to claim 1, characterized in that the

Circulatory medium is a synthetic circulatory medium.

5. The method according to at least one of the preceding claims, characterized in that the circulation medium is a mixture which consists of two or more components.

6. The method according to at least one of the preceding claims, characterized in that the circulation medium is a mixture with a lowered freezing point, ie an antifreeze mixture, such. As water and glycol or ethanol is.

7. The method according to at least one of the preceding claims, characterized in that the circulation medium is a zeotropic mixture which distils apart during the heat absorption.

8. The method according to at least one of the preceding claims, characterized in that the circulation medium is a sorptives

Mixture, which during heat absorption the

desorbs more volatile component and absorbs it during mixing.

9. The method according to at least one of the preceding claims, characterized in that the circulation medium of the dry Belongs class, which in an expansion away from the wet steam area.

10. The method according to at least one of the preceding

Claims, characterized in that the circulation medium is operated subcritically in a steam generator and the

Steam generators (4) Heating surfaces for preheating (14), for

Evaporation (16) and possibly to overheat the

Circulation medium has (Fig. 2, Fig. 8).

11. The method according to at least one of the preceding

Claims, characterized in that the circulation medium is operated supercritically in the steam generator and the steam generator (4) heating surfaces for preheating (14) and for reheating (16) of the circulation medium has (Fig. 2).

12. The method according to at least one of the preceding

Claims, characterized in that a feed line (11) to a boiler feed line (13), optionally via a

Armature and or a branch (24a), closes (Fig. 8, Fig. 8).

2).

13. The method according to at least one of the preceding

Claims, characterized in that the number of

Branches (24) is greater than the number of mixers (31)

(Figures 2, 8).

14. Method according to at least one of the preceding

Claims, characterized in that at least one mixer, preferably the medium-pressure mixer (31MD), two or more Zumischteintritte, preferably the two Zumischteintritte (32 b and 32 c), has (Fig. 2, Fig. 8).

15. The method according to at least one of the preceding claims, characterized in that the mixer (31) has a nozzle or a nozzle group (34), with which the branched stream is introduced into the interior of the mixer (Fig. 4).

16. The method according to at least one of the preceding

Claims, characterized in that the mixer (31)

Has filling body (36) which via a

Sprinkling device (37) with the branched stream

be sprinkled (Fig. 5).

17. The method according to at least one of the preceding

Claims, characterized in that the mixer (31) a liquid separator (40) is connected downstream (Fig. 6).

18. The method according to at least one of the preceding

Claims, characterized in that the medium pressure mixer

(31MD), if necessary with the downstream one

Liquid separator (40), a medium-pressure turbine (19MD) is connected downstream (Fig. 2, Fig. 8).

19. Method according to at least one of the preceding

Claims, characterized in that the low pressure mixer

(31ND) an exhaust steam condenser (8) is connected downstream (FIG. 2,

Fig. 8th ) .

20. The method according to at least one of the preceding

Claims, characterized in that the heat exchanger (28ND) in the connecting path (25ND) to the low-pressure mixer (31ND), the heat outside the cycle outputs (Fig. 2, Fig. 8).

21. The method according to at least one of the preceding claims, characterized in that the heat exchanger (28ND) in the connecting line (25ND) to the low-pressure mixer (31ND) dissipates the superheat and the condensation heat of the exhaust steam of the exhaust steam line (20ND), so that the desuperheating and

Condensation of the exhaust steam takes place in the low-pressure mixer (31ND) and condensate comes from the cold exhaust steam line (21ND) and this condensate is led directly into the condensate line (9) (FIGS. 2, 8).

22. Method according to at least one of the preceding

Claims, characterized in that a branch (24b and / or 24c) before the end of a preheater (14), which is characterized by the achievement of the lowest temperature difference between the heat carrier and the circulating medium (Fig. 2, Fig. 7, Fig . 8th) .

23. Method according to at least one of the preceding

Claims, characterized in that branches (24b and / or 24c) of distributors and / or collectors (43) of the

Preheater (14), its Heizflächenpakete (42) or his

Connecting lines take place (Fig. 7).

24. The method according to at least one of the preceding

Claims, characterized in that branches (24b and / or 24c) from the jacket space of the preheater (14), wherein the heat carrier is guided on the tube side, take place (Fig.

8th) .

25. The method according to at least one of the preceding

Claims, characterized in that within the

Links (25a, 25b, 25c or 25HD) the respective Heat exchangers (28a, 28b, 28c and 28HD) are heated by another, external heat source.

26. Method according to at least one of the preceding

Claims, characterized in that the heat exchanger (28) of the connecting path (25) before, after or parallel to

Preheater (14) is arranged and this from the stream or

Partial flow of the heat carrier is heated (Fig. 9).

27. Method according to at least one of the preceding

Claims, characterized in that the heat exchanger (28) is heated by a branched stream of the heat carrier by in the region of the preheater (14) from the heat carrier side this branched off stream via a bypass branch (44) and optionally via a bypass flap (45) and after the

Heat output via a bypass return line (46) is supplied to the main stream (Fig. 10).

28. The method according to at least one of the preceding

Claims, characterized in that the flow rate and the state of the outlet (30) of the connecting line (25) by the feed pump (27), or the heat exchanger (28), or the valve (29) is controlled such that the state in the cold

Evaporating line (21) comes to rest near the saturation line (Fig. 3).

29. Method according to at least one of the preceding

Claims, characterized in that the throughput of the

Inflow to the connecting line (25) via the bypass branch (44) and the bypass control flap (45) is controlled such that the temperature of the circulating medium in the bypass return line (46) and in a return line (5) of the heat carrier is almost equal (Fig. 10) ,

30. The method according to at least one of the preceding claims, characterized in that the branch (24 b and / or 24 c) takes place at the place where the preheating temperature at this branch is equal to or higher than that

Steam saturation temperature in the exhaust steam line (20MD).

31. Energy conversion device for increasing the

Temperature levels, which are available to the cycle

Circulation medium supplied via a condensate line to a condensate pump and is increased by this pressure, this

characterized in that in the heat-absorbing part of

Energy conversion device, between the condensate line (9) and the main steam line (18), at least one branch (24) is provided, which is a flow from the main stream of the

Mixer (31) opens, which the branched stream with the exhaust steam from the exhaust steam line (20) of the expansion machine or the turbine (19), provided via the steam supply line (33), mixed and this mixed stream over the Steam discharge (35) and the cold exhaust steam line (21) in the cyclic process back and forth is continued (Fig. 2, Fig. 8).

32. Energy conversion device according to claim 31, characterized in that the device has a steam generator (4) with heating surfaces for preheating (14), for evaporation (16) and optionally for overheating of the circulation medium and the circulation medium is operated subcritically in the steam generator (FIG , Fig. 8).

33. Energy conversion device according to at least one of the preceding device claims, characterized in that the device has a steam generator (4) with heating surfaces for preheating (14) and reheating (16) of the circulation medium and the circulation medium is operated supercritically in the steam generator (Fig. ,

34. Energy conversion device according to at least one of the preceding device claims, characterized in that the feed line (11) to the boiler feed line (13), optionally via a valve and or a branch (24a), closes (Fig. 8, Fig. 2).

35. Energy conversion device according to at least one of the preceding device claims, characterized in that the number of branches (24) is greater than the number of mixers (31) (Fig. 2, Fig. 8).

36. Energy conversion device according to at least one of the preceding device claims, characterized in that at least one mixer, preferably the medium-pressure mixer (31MD), two or more Zumischteintritte, preferably the two Zumischeintritte (32 b and 32 c), has (Fig. 2, Fig. 8).

37. Energy conversion device according to at least one of the preceding device claims, characterized in that the mixer (31) has a nozzle or a nozzle group (34), with which the branched stream is introduced into the interior of the mixer (Fig. 4).

38. Energy conversion device according to at least one of the preceding device claims, characterized in that the mixer (31) filler (36) which are sprinkled via the sprinkler (37) with the branched stream (Fig. 5).

39. Energy conversion device according to at least one of the preceding device claims, characterized in that the mixer (31) has a liquid separator (40)

is connected downstream (Fig. 6).

40. Energy conversion device according to at least one of the preceding device claims, characterized in that the medium-pressure mixer (31MD), optionally with the downstream liquid separator (40), a medium-pressure turbine (19MD) is connected downstream (Fig. 2, Fig. 8).

41. Energy conversion device according to at least one of the preceding device claims, characterized in that the low-pressure mixer (31ND) of the exhaust steam condenser (8) is connected downstream (Fig. 2, Fig. 8).

42. Energy conversion device according to at least one of the preceding device claims, characterized that the heat exchanger (28ND) in the connection line (25ND) to the low pressure mixer (31ND) the heat outside of the

Circuit process outputs (Fig. 2, Fig. 8).

43. Energy conversion device according to at least one of the preceding device claims, characterized in that the heat exchanger (28ND) in the connecting line (25ND) to the low-pressure mixer (31ND) the superheat and the

Evaporating line (21ND) condensate comes and this condensate is led directly into the condensate line (9) (Fig. 2, Fig.

44. Energy conversion device according to at least one of the preceding device claims, characterized in that a branch (24b and / or 24c) before the end of

Preheater (14), which by reaching the

lowest temperature difference between the heat carrier and the circulating medium is characterized (Fig. 2, Fig. 7, Fig. 8).

45. Energy conversion device according to at least one of the preceding device claims, characterized in that branches (24b and / or 24c) of distributors and / or collectors (43) of the preheater (14), its Heizflächenpakete (42) or its connecting lines carried out (Fig ).

46. Energy conversion device according to at least one of the preceding device claims, characterized in that branches (24b and / or 24c) from the shell space of the

Preheater (14), in which the heat transfer medium is guided on the tube side, take place (FIG. 8).

47. Energy conversion device according to at least one of the preceding device claims, characterized in that within the connecting sections (25a, 25b, 25c or 25HD) the respective heat exchangers (28a, 28b, 28c and 28HD) are heated by a further, external heat source.

48. Energy conversion device according to at least one of the preceding device claims, characterized in that the heat exchanger (28) of the connecting line (25) before, after or parallel to the preheater (14) is arranged and this is heated by the stream or partial flow of the heat carrier (Fig ).

49. Energy conversion device according to at least one of the preceding device claims, characterized in that the heat exchanger (28) is heated by a branched stream of the heat carrier by in the region of the preheater (14) from the heat carrier side of this branched stream over the

Bypass return line (46) is supplied to the main stream (Fig. 10).

50. Energy conversion device according to at least one of the preceding device claims, characterized in that the throughput and the state of the sequence (30) of the

Connecting line (25) by the feed pump (27), or the heat exchanger (28), or the valve (29) is controlled such that the state in the cold exhaust steam line (21) comes to rest near the saturation line (Fig. 3).

51. Energy conversion device according to at least one of the preceding device claims, characterized in that the throughput of the inflow to the connecting line (25) via the bypass branch (44) and the bypass control flap (45) are regulated in such a way that the temperature of the circulation medium in the bypass return line (46) and in the return line (5) of the heat carrier is almost identical (FIG. 10).

52. Energy conversion device according to at least one of the preceding device claims, characterized in that the branch (24 b and / or 24 c) takes place at the location where the preheating temperature at this branch is equal to or higher than the steam saturation temperature in the exhaust steam line (20MD).