WO2013135761A2

WO2013135761A2 - Power regulation and/or frequency regulation in a solar thermal steam power plant

Info

Publication number: WO2013135761A2
Application number: PCT/EP2013/055120
Authority: WO
Inventors: Matthias BUGGERT; Wolfgang WIESENMÜLLER
Original assignee: Siemens Aktiengesellschaft
Priority date: 2012-03-16
Filing date: 2013-03-13
Publication date: 2013-09-19
Also published as: DE102012204219A1; WO2013135761A3

Abstract

The invention relates to a method for, in particular automatic or alternated, power regulation and/or frequency or primary and/or secondary frequency regulation in a solar thermal steam power plant with a primary heat source that is not freely adjustable and an additional heat source and also a solar thermal steam power plant. According to the invention, on the basis of the method for power regulation and/or frequency or primary and/or secondary frequency regulation in this solar thermal steam power plant (1), provision is made for the additional heat source (20) to be used in a primary circuit (2) of the solar thermal steam power plant (1) in order to fill at least one thermal energy store (63, 47) in a secondary circuit (3) of the solar thermal steam power plant (1).

Description

description

Power control and / or frequency control in a solar thermal steam power plant

The invention relates to a method for a Leistungsrege ^¬ ment and / or frequency or primary and / or a secondary control in a solar thermal steam power plant with a not freely adjustable primary heat source and an additional borrowed heat source and a solar thermal steam power plant.

Steam power plants in their general form are well known, for example

http://de.wikipedia.org/wiki/Dampfkraftwerk (available on 14.03.2012).

A steam power plant is a type of power plant for

Power generation, in which a thermal energy of steam in a steam turbine is converted into kinetic energy and further converted into electrical energy in a generator.

In such a steam power plant, the steam required for operating the steam turbine is first of all generated in a steam boiler from previously cleaned and prepared (feed) water. By further heating the steam in a superheater, the temperature and specific volume of the steam increase. From the steam boiler, the steam flows via pipelines into the steam turbine, where it delivers part of its previously absorbed energy as kinetic energy to the turbine. To the turbine, a generator is coupled, which converts mechanical Leis ^¬ tion into electrical power.

Thereafter, the expanded and cooled steam flows into the con ^¬ capacitor, where it is condensed by heat transfer to the environment and accumulates as liquid water. Through condensate pumps and preheaters through the water is cached in a feedwater tank and then through a feed pump and preheater through the again

Steam boiler supplied, whereby a circuit is closed.

Various steam power plant species, as with ^¬ play as coal power plants, oil plants, gas and steam combined cycle power plants (CCPP) as well as solar thermal steam power plants (short solar thermal hereinafter Kraftwer ^¬ ke), a distinction.

Solar thermal power plants are also known, example ^¬ from http: // de. wikipedia. org / wiki / Solar thermal power plant (available on 14.03.2012).

A solar thermal power plant is a special form of steam power plant, in welehern solar energy is used as a primary source of energy or heat source for steam generation.

For this purpose, such a solar thermal power plant has two - via a heat exchanger (thermal) coupled - circuits, a primary (solar circuit) and a secondary circuit (water-steam cycle), ie. It works on a two-circuit principle.

In the primary circuit or solar cycle is - to ^¬ usually a plurality of solar collectors, arranged in a solar collector field, flowing through - heat transfer medium, for example (thermal) oil there by solar irradiation he warms ^¬ (primary heat / energy source or primary energy / Heat supply).

The heated heat transfer medium continues to flow through the heat ^¬ exchanger by the recorded thermal energy to the secondary circuit, the water-steam cycle, or to the local process medium, ie to a (food) water transmits.

Thereafter, the - now cooled - heat transfer medium flows back to the solar collectors, whereby the primary circuit or the solar circuit is closed.

Through the heat transfer from the primary circuit to the secondary ^¬ circuit or to the water-steam circuit of the (food grade) is where water is converted into steam, that is, it is heated, vaporized and superheated, and flows via Rohrleitun ^¬ gen to the steam turbine, in the water vapor releases some of its energy to the turbine as relaxation energy as relaxation energy.

By coupled to the turbine generator, the mechanical power is then converted into electrical power, which is fed as electrical power in a power grid.

Is generally below the turbine, the condenser being arranged ^¬, in which the steam - after expansion in the turbine - the largest part of its heat transfer to the cooling water. During this process, the vapor liquefies by condensation.

The feed water pump promotes the resulting liquid water as feed water again to the heat exchanger, which also the secondary circuit is closed.

All of the information obtained in a solar thermal steam power plant, such as measured values, process ^¬ or state data are displayed in a control room and there, usually in a central processing unit, evaluated, operating states of individual power plant components are displayed, evaluated, controlled, controlled and / or regulated , Via control units, a power plant operator can intervene in a Be ^¬ operating sequence of the power plant, for example by opening or closing a valve or a valve or by a change in a supplied Brennstoffmen- ge.

The central component of such a control room is a Leit ^¬ computer, on which a block management, a central control or control and / or regulating unit, - for example, as an automation system / automation software - implemented by means of which a control, a STEU ^¬ tion and / or a regulation of the solar thermal power plant can be carried out. In a deregulated electricity market gain a more flexible

Load operation of power plants and facilities for frequency control in power grids for power plant operation more and more important. With regard to the frequency control in power grids, a distinction is made between different types of frequency control, for example a primary control and a secondary control with or without a so-called dead band. Since electrical energy on the way from producer to consumer ^¬ cher can not be stored, electricity generation and consumption must be in equilibrium at every moment in the power grid, meaning it has to be generated as much electrical energy as is consumed. The frequency of the elec- innovative energy is the integrating control variable and assumes the power frequency rated value as long as electricity generation ^¬ supply and power consumption are in balance. The speeds of the power plant generators connected to a power grid are synchronized with this grid frequency.

If, at any given time to a Erzeugungsde ^¬ deficit in the power grid, so this deficit is first ei ^¬ ne in centrifugal masses (of rotating machinery turbines, Ge generators). As a result, the machines are braked, as a result of which their speed and thus the (network) frequency continue to drop.

Failure to counteract this drop in grid frequency by appropriate power or frequency regulation in the grid would lead to grid collapse.

Within the so-called deadband in the range of small frequency deviations of up to V-0.07-0.1 Hz normally no control interventions take place. It is possible in this area only a delayed slow counter-control to compensate for remaining deviations between generation and consumption.

Larger frequency deviations in the range of 0.1-3.0 Hz, caused for example by power plant failures and

Fluctuations in electricity consumption are distributed by the primary control system to the power plants involved in primary control throughout the electricity grid. These provide a so-called primary control reserve, ie a power reserve, which is automatically supplied by the participating power plants to the power grid in order to compensate for the imbalance between production and consumption within seconds by regulating production.

The primary control thus serves to stabilize the network frequency with as small a deviation as possible, but at a level deviating from a prescribed nominal power frequency value.

The subsequent to the primary control Sekundärregelun has the task to restore the balance between the ^{Stromerzeu ¬} like and consumers in the power grid and thereby the network frequency again to the predetermined Netzfre quenznennwert, z. B. 50 Hz, due. For this purpose, the power plants involved in the secondary control provide a secondary control ^{reserve in} order to restore the grid frequency to the nominal grid frequency and restore the balance in the grid.

The request for the primary control reserve and the discharge of the primary control reserve into the power grid are automatic by the control equipment of the power plants involved in the primary control (the power grid as such or the frequency change in the power grid requires the primary control reserve), whereas the secondary control is provided by a Parent network controller in the power grid at the power plants involved in the secondary control requested and then released to this request from the power plants in the power grid.

In part, the provision of frequency or primary and / or secondary control reserve for the power plants in - by national regulations - certain extent mandatory; Control reserves provided by the power plants are usually remunerated to the power plants as special network services.

Thus participation in frequency control or power control mode can also be economically attractive for solar thermal steam power plants. Also, an expansion of renewable energy (e.g., wind energy) is expected to exacerbate demands on governing capability of different types of power plants. Thus, it is to be expected that the requirement for frequency regulation will in future also be laid down for solar thermal power plants.

The operation of a solar thermal power plant has recently ^¬ of all the disadvantage that this is not a performance by the inertia of the solar-thermal process and / or frequency control capable due to the non freely adjustable primary heat source and to ground. It should be understood by the non-freely adjustable primary heat source that this primary heat source conditions is subject ^¬ gene, which are outside of a power plant side influence, - and it so - from the viewpoint of the power plant - is not freely adaptable. Thus beispielswei ^¬ se subject to sunlight or their primary supply of heat to the heat carrier medium more or less random, unpredictable changes, such as by changing sunlight or cloudiness, whereby such heat source is powerful factory not freely adjustable.

A generally large-scale expansion of the solar collector field also leads to temporally strongly delayed changes in the solar collector field. This can not be caused by a change in focusing of the solar collectors targeted adjustment of the generator power, which also the

Power and / or frequency control capability in a so ^¬ larthermal power plant severely limited. A power control and / or frequency or a primary and / or secondary control, or the provision of a frequency or primary and / or secondary control reserve - as desired or as required - is not possible in such solar thermal power plants.

In order nevertheless to allow a certain power adaptation in solar thermal power plants, an additional heat source, for example an additional natural gas firing by means of special natural gas boilers, can be provided in the primary circuit for the primary heat source (in the solar cycle).

This additional heat source and in particular a such additional natural gas firing, in particular arranged so ^¬ stellar circuit shear immediately before the heat exchanger or heat exchangers, allows, as required, the temperature of Wärmeträ ^¬ transfer medium in the primary circuit to adjust, thereby correspondingly more or less electrical Power can be generated in the secondary circuit. If heat is supplied or reduced as required by the additional heat source, for example natural gas firing, the delivered electrical power plant output can be stabilized in such a solar thermal power plant with non-freely adaptable primary heat source / supply and with an additional heat source / heat supply or to some extent electric power ramps, as well as a frequency or primary and / or a secondary control are driven.

Limited - also here, i. in such a solar thermal power plant with - not freely adaptable - primary heat source and additional heat source, as with solar thermal power plants in general - the achievable

Performance only by a determined optional power, i. a maximum mobile power of the power plant depending on the condition of individual power-limiting units (e.g., feed pumps in operation).

Moreover, the additional heat source can also be used in the primary ^¬ circulation to keep the heat transfer medium liquid ( "antifreeze protection"). A measure of the use of this additional heat source, such as the additional natural gas firing, but is based solely and alone For economic reasons, such additional firing or heat input requires additional / increased fuel and / or power plant costs.

Although a ge ^¬ certain power ^adjustment in these solar thermal power plants in principle is possible by such additional heat, so the disadvantage remains that it is not foreseeable in which area or extent the power adjustment is possible or a

Power regulation is possible because the fluctuations in the - unadaptable - primary heat source, ie the Solar energy, can not be influenced by the power plant and occur more or less randomly.

But this is also such a solar thermal power plant - with not freely adjustable primary heat source and additional heat source due to the random fluctuations occurring in the primary heat supply not performance and / or frequency or primary and / or secondary controlled, which - as a minimum negative impact - incurs corresponding revenue losses for the operator of the power plant.

For acceleration of power changes in the context of frequency control or secondary and / or primary control in steam power plants, it is known ("Flexible Load Operation and Frequency Support Steam Turbine Power Plants", Wichtmann et al., VGB Power Tech 7/2007, pages 49 -. 55), to use fast-acting additional measures which are based on the use of energy contained in the process medium of the steam power plant, ie in the feed water or water vapor ("thermal (energy) storage in the water-steam cycle").

Well-known examples of this are a throttling of a high-pressure turbine control valve, an overload introduction to the high-pressure turbine part, a condensate backflow, a bypass of high-pressure preheaters on the feed water side, and a discharge of the bleed steam lines to the high-pressure preheaters.

This process medium-immanent energy storage and this thermal storage in the water-steam circuit are aller- recently limited so that also is limited by available alternate ^¬ bare control reserve.

There is also the need to replenish such a thermal storage in the water-steam cycle when the energy storage or thermal storage in the water-steam circuit is once used / emptied, which further restricts the Regelreser ^¬ ven. The invention has for its object to provide a method which one, in particular automatic or auto ^¬ matisierte, power control and / or frequency or primary and / or secondary control, in a solar thermal power plant with a non-adjustable primary heat source and a additional heat source allows. Also is the He ^¬-making based on the object to create a suitable for a particular au ^¬ matic or automated, power control and / or frequency or primary and / or secondary control solar thermal power plant.

The object is by the method for, in particular auto ^¬ matischen or automated, power control and / or frequency or primary and / or secondary control in a solar thermal steam power plant with a non-adjustable primary heat source and an additional heat source and by a solar thermal power plant the features according to the respective independent claim.

Preferred developments of the invention will become apparent from the dependent claims. The further developments relate both to the method according to the invention and to the solar thermal power plant according to the invention. The dung OF INVENTION ^¬ modern solar thermal power plant is particularly geeig ^¬ net for carrying out the method of the invention or one of its developments explained below.

The invention and the developments described can be implemented both in software and in hardware, for example using a special electrical circuit.

Furthermore, a realization of the invention or a further development described is possible by a computer-readable storage medium on which a computer program is stored, which carries out the invention or a further development. The invention and / or any further development described can also be realized by a computer program product which has a storage medium on which a computer program is stored which carries out the invention and / or the development.

The invention relates to a solar thermal power plant with a primary as well as with the primary, in particular via a heat exchanger (thermal) coupled secondary circuit.

In the primary circuit is a - to a non anpassba ^¬ ren primary heat source for a primary supply of heat - additional heat source to a (additional) increasing or decreasing the supply of heat a circulating in the primary circuit heat transfer medium, for example a

(Thermal) oil, provided.

The secondary circuit also has at least one thermi ^¬ rule energy storage.

Such a thermal energy storage - in the secondary

Circulation - can be based on in a process medium of the secondary circuit, such as in a feedwater or water vapor of a water-steam cycle, immanent energy storage. For example, a throttling of a high-pressure turbine control valve, an overload introduction to the high-pressure turbine part, a condensate accumulation, a bypass of high-pressure preheaters and a Androsse- treatment of the bleed steam lines to the Hochdruckvorwärmern known thermal energy storage ("Flexible Load Operation ^¬ tion and Frequency Support for Steam Turbine Power Plants ", Wichtmann et al., VGB Power Tech 7/2007, pages 49-55).

Such a thermal energy storage allows - in "retrieval" of the stored energy, eg by changing the throttling or building up the condensate - to some extent a change in performance in the secondary circuit. However, emptied it, ie "recall" there vomit ^¬ cherter energy, thermal energy storage.

According to the invention, it is provided according to the method for power control and / or frequency or primary and / or secondary frequency control in this solar thermal steam power plant, that the additional heat source is used to replenish the at least one thermal energy storage in the secondary circuit.

To put it simply or simply, a thermal energy store in the secondary circuit that is no longer full is filled in the primary circuit using the additional heat source.

For this purpose, the additional heat input - be activated or increased by the additional heat source, such as a gas burner, on the heat transfer medium in the primary circuit, which - by the (thermal) coupling of the primary with the secondary circuit - to an additional energy input into the process medium of secondary cycle leads.

This additional energy input in the process medium of the seconding ^¬ dary cycle can fill the thermal energy storage are used in the secondary circuit then for the (re) - without that changes a power of the solar thermal power plant or drops.

The corresponding solar thermal power plant according to the invention has a data processing means, in particular a programmed computing unit, in particular implemented in a block guide, which is set up such that the inventive method for power control and / or frequency control is performed.

Thus, the inventive method allows for Leis ^¬ processing control and / or frequency or primary and / or secondary darfrequenzregelung as well as the corresponding erfindungsge ^¬ mäße solar thermal power plant a power control

and / or frequency or primary and / or secondary frequency control in this solar thermal power plant, because of the invention (re) filling the thermal energy storage in the secondary circuit - regardless of the power plant output - this "repeatedly replenished" thermal energy storage almost constantly represents Leis ^¬ directional changes within the frequency control or secondary and / or primary control in the solar thermal power plant available.

The invention proves to be considerably advantageous in many respects.

Thus, the invention enables a power control operation of the solar thermal power plant. In particular, the invention ^¬ It enables frequency or primary and / or secondary control capability of the solar thermal power plant.

Thus, required grid connection conditions can be met by a solar thermal power plant operated according to the invention. The plant operator also receives corresponding remuneration for the primary and / or secondary regulation.

Preferred developments of the invention will become apparent from the dependent claims. The developments described relate both to the method according to the invention and to the power plant according to the invention.

Conveniently, ie to allow for increased and / or accelerated power adjustments in the solar thermal power plant, several such thermal energy stores can be used in any combination or multiple times in the secondary circuit, each of which can be refilled using the additional heat source. According to a preferred embodiment, the filling of the thermal energy storage means of the additional heat source is dependent on a degree of filling of the thermal energy storage. If, for example, the degree of filling of the thermal energy store falls below a certain level, it can be filled according to the invention.

Thus, the thermal energy storage can always be kept at or above a predetermined degree of filling. In particular, the thermal energy store can always be filled completely or be.

It can further be provided that the data processing means according to the invention is part of a block of the guide ^¬ solar thermal power plant. For this purpose, the data processing ^¬ medium may be implemented in the block management.

According to a particularly preferred embodiment, the solar thermal power plant just then such a block guide, which is adapted to carry out the invention.

In other words, it may be expedient to implement the Invention ^¬ method according or their training in a block guidance of the solar thermal power plant, which then perform the inventive method and / or their Wei ^¬ developments of - and accordingly control the solar thermal power plant and / or regulate or can drive.

It may also be appropriate that the additional sources of heat ^¬ le allows quick heat input to the heat transfer medium and / or that - within wide ranges - is re ^¬ Gelbar. In particular, several smaller additional heat ^¬ sources ("small denominations") - instead of a large additional heat source - may be useful here.

For example, the additional heat supply for the heat transfer medium or on the heat transfer medium, a natural gas fire with a corresponding special natural gas burner or Natural gas boilers - or, in the case of smaller denominations - be with several natural gas burners or natural gas boilers or take place by means of such. Other additional firings, such as coal or oil firing, are also possible.

According to a further preferred refinement, a method is provided for adjusting the nominal value of a nominal value in the solar-thermal power plant, in particular in the context of an automated power control or frequency or primary and / or secondary frequency control.

With this setpoint adjustment it can be provided that a current power range ((power) window) for the solar thermal power plant is determined for at least one predetermined time during operation of the solar thermal power plant.

This current power range of the solar thermal steam power plant can be limited by a lower control range limit and by an upper control range limit.

Further, the current output range can be performed using a current output from the current primary heat supply through the primary heat source as well as using egg nes power range from the additional heat source ^¬ be true.

In other words, the current power range results from the current power from the current primary heat input by the primary heat source and / or the power range of the additional heat source.

In the lower control range limit, a lower Leis ^¬ tung reserve can be considered processing rules with at least one replacement percentage for a performance and / or frequency or primary and / or secondary frequency control. In the upper control range limit, an upper power ^¬ reserve will also be taken into account with at least one replacement percentage for power control and / or frequency or primary and / or secondary frequency control.

When the setpoint adjustment can then be a current, for example, predetermined by a load distributor, setpoint of the solar thermal power plant, if the currently specified setpoint is outside the current power range, be set in the current power range.

The limits of the current power range can also be part of the current power range. Expressed differently or further education, a current power range (power window) for the power plant is determined here at a time of operation of this solar thermal power plant. This current power range is determined by the

Power, which is achievable by the primary heat source / supply, ie by solar energy, and - whereby the Leis ^{¬ area is} spanned as a window - by one hand, the performance which is achieved by the minimum possible additional heat (minimum additional heat input or -. firing) and on the other hand, the power, which is achievable by the ma ^¬ ximal possible additional heat (maxima ^¬ le additional heat supply or -feuerung). With this minimum and maximum possible additional heat ^¬ supply maximum possible - down and up - technical boundary conditions of the additional heat source can be considered. The minimal additional heat can erge ^¬ ben from the fact that a certain (minimum) is necessary amount of additional Wär ^¬ mezufuhr to operate the additional source of heat stable. Accordingly, a maximum additional From this heat supply result that a stable operation of the additional heat source "up" is limited.

At the limits of this current power range from current primary heat input and additional heat input (minimum and maximum additional heat input), a power reserve with at least one power reserve component for power control and / or frequency or primary and / or secondary frequency control can then be "installed" respectively be taken into account.

That is, the limits of this current power range are pushed together in each case by this to be incorporated, or to be considered Leis ^¬ tung reserve, whereby the current output range for these two performance margins at upper limit and lower limit is reduced - and thus for these current power range a spare portion for a power control and / or frequency or primary and / or secondary frequency control is available or guaranteed.

The limits of the current power range can be considered as belonging to the area. These limits can be as limitations or of this current power range / (power) window may then be connected as a limitation to a set point adjuster of this solar thermal power plant, which the currently pre give ^¬ external command value if it lies outside the power window, that within the current Leistungsfens ^¬ ters sets or leads into the current power window (setpoint adjustment).

Illustratively, here the current setpoint to be adjusted can be pushed at least to / to the corresponding relevant upper or lower window limit. A further displacement of the target value within the current power window is possible, for example, to the middle of the power window, however it appears appropriate to the desired value "only" to the Leistungsfenster- limit zoom down, thereby avoiding unnecessarily large power ^¬ fluctuations of the system.

Then located the predetermined or adjusted target value of this solar ^¬ thermal power plant within this Leistungsfens- ters, a power control, such as an electric Leis ^¬ tung ramp, the secondary or primary control, this solar thermal power plant is always possible or ensured.

Regardless of the achievable performance of this solar thermal power plant is only limited by a ermit ^¬ Telte Can performance, that is, a maximum mobile performance of the solar thermal power plant according to the state a ^¬ of individual power limiting units (for example, feed pumps in operation).

The current power window and / or its limits can - for information - also be transmitted to the load distributor. If this setpoint adjustment over a time course, ie at successive times, a time interval, for example an operating phase or an operating time ^¬ ses steam power plant / solar thermal power plant, durchge leads ^¬ so shifts with each of the currently available primary heat quantity, in particular solar radiation , (over time) the power window, within which the setpoint - for ensuring the power control and / or frequency or primary and / or secondary frequency control of this steam power plant - may lie, only automatically up or down.

This is associated with an automatic adjustment of the possible setting range of the setpoint adjuster. A current setpoint, which would now lie abruptly above the upper limit of the power window due to a reduction in the primary amount of heat, in particular when, for example, entry of clouds, and / or additional heat quantity capacity, can be adjusted accordingly by the setpoint adjuster, ie it can from the sinking upper Limitation automatically be guided down. Once, due to a change or increase in the primary heat amount, in particular, for example, cloudless Son ^¬ neneinstrahlung, and / or additional amount of heat capacity, the upper limit is shifted upward again, and thereby the desired value previously led mitge- with the upper power window limit down "game after above ", the setpoint can also be adjusted as far upwards as possible.

That is, the target value, the overall by the displacement of the upper power window limit upward at his disposal presented exploit game and as much as mög ^¬ Lich (power), that is again limited by the translating upwardly power window limit, upward in the direction of the ur ^¬ originally predetermined outside the then performance window lying setpoint move.

This can be done as long as until the setpoint reaches the originally ^¬ Lich predetermined lying outside the former performance window level or a new setpoint is specified, which is within the current performance window.

Alternatively, however, the setpoint value can initially also be left at the level with the upper power window limit shifting upwards until a new, current setpoint is specified.

The same also applies to current setpoint values suddenly lying below the lower limit of the performance window. In particular, it is expedient to implement this setpoint adjustment in the block management of the solar thermal power plant, which then executes the setpoint adjustment - and so the solar thermal power plant automated control in a power control mode and / or can regulate or drive.

The description of advantageous embodiments of the invention given hitherto contains numerous features which are reproduced in some detail in the individual subclaims. However, those skilled in the art will conveniently consider these features individually and summarize them to meaningful further combinations.

In particular, these characteristics are in each case individually and in liebiger be ^¬ suitable combination with the method according to the invention and / or with the apparatus according to the respective independent claim combinable.

In the figures, an embodiment of the invention is shown, which will be explained in more detail below.

Show it:

1 shows a control / control / system diagram of a power control capable solar thermal power plant according to an embodiment, FIG 2 is a schematic representation of a Leistungsfens ^¬ ters of the power control performance solar thermal power plant according to FIG 1,

3 shows service areas and performance of a so-larthermischen power station in actual operation, and in Leistungsfol ^¬ give operating according to the embodiment. Embodiment: Automated power control enabled so ^¬ larthermisches power plant

FIG. 1 shows a control / control / system diagram 60 of a power-setting solar thermal power plant 1.

Notwithstanding usual solar thermal power plants is the power plant 1 described here - in addition to customary processes known actual operation of the plant a, c and 72 - automatic ^¬ tisiert power control capable mobile ( "load setting mode" / output sequential operation) b and 71 ,

The power control capability of this solar thermal power station level 1 includes the ability of the secondary Rege ^¬ adjustment ( "Secondary grid frequency control").

All of the information obtained in the solar thermal power plant 1, such as measured values, process or status data are displayed in a control room and there in a central processing unit 64, a block guide 61 - as a central control or control and / or regulating organ of solar thermal Power station 1, evaluated, with operating states of individual power plant components are displayed, evaluated, controlled, controlled and / or regulated.

About control organs can intervene there by a control room operator (operator) on the Blockführung - as a central part of the host computer - or automatically in the operation of the solar thermal power plant 1 - and thereby the system - driven, for example, by opening or closing a valve or a valve or also by a change in an amount of fuel supplied. In particular, the power control and / or Frequenzbzw. Primary and / or secondary frequency control and the automatic load following operation 71 of the solar thermal power plant 1 is controlled via the block guide 61. This solar thermal power plant 1, also in the following only briefly power plant 1, has two - via a multi-stage heat exchanger 40 (thermally) coupled - circuits 2, 3, a primary- (solar circuit) 2 and a secondary circuit (What ^¬ water vapor Cycle) 3, ie it operates on a two-circuit principle.

In the primary circuit or solar circuit 2 is a mostly a plurality of in a solar collector array 11 to ^¬ ordered solar panels 12 by flowing Wärmeträgerme ^¬ dium 13, here a (thermal) oil 13, there heated by solar radiation 10 (primary heat / Energy source or primary energy / heat input or input, primary energy / source 10).

The heated heat transfer medium 13 also flows through a natural gas fired natural gas boiler 21, in which the "primary heated" thermal oil 13 is further heated 20 or can (additional heat source / supply, additional energy / source 20).

This additional heat source 20 on the one hand used to operate the plant 1 economically optimal, the - uncontrollable fluctuations unsuccessful - power from the primary power source 10 to stabilize and - described as nachfol ^¬ quietly in detail - the frequency control ability and the automatic load-following operation 71 of the Power plant 1 to ^¬ possible. On the other hand, the additional heat source 20 is used to keep the thermal oil 13 liquid ("anti-freeze protection").

Subsequent to the additional heat source 20, the thermal oil 13 flows through the heat exchanger 40, where it - at least partially - the absorbed thermal energy from primary and possibly additional heat 10, 20 to the secondary circuit 3, the water-steam circuit 3, or. to the local process medium 41, ie to a (food) water 41 transmits.

Thereafter - promoted by a feed pump 23 - the - now cooled - heat transfer medium 13 or thermal oil 13 ^¬ back to the solar panels 12 and the solar panel 11, whereby the primary circuit 2 and the solar circuit 2 is ge ^¬ closed. Through the heat transfer from the primary circuit 2 to the seconding ^¬ därkreislauf 3 or to the water-steam circuit 3, the (food grade) is where water is converted into steam 41 41, ie it is heated, vaporized and superheated, and flows through conduits 43 to the steam turbine 42, in which the water vapor 41 releases a part of its energy by relaxation as kinetic energy to the turbine 42.

By the coupled to the turbine 42 generator 44, the mechanical power is then converted into electrical power, which is fed as electrical current into a power grid 33 45.

Below the turbine, a condenser 46 is arranged, in which the steam 41 - after relaxation in the turbine 42 - transmits most of its heat to cooling water. During this process, the vapor 41 liquefies by condensation ^¬ tion.

A feedwater pump 48 conveys the resulting liquid water 41 as feed water 41 again to the multi-stage heat exchanger 40, whereby the secondary circuit 3 is closed ^¬ sen.

In the secondary circuit 3, ie in the water-steam cycle 3, various thermal storage 63 are reali ^¬ Siert, which are based on a the feed water 41 and water vapor 41 immanent energy storage. FIG 1 shows example here such thermi ^¬ rule memory 63 in the form of a throttling of a high-pressure turbine control valve 47 and a high pressure turbine control valve throttle 47th

Other - unspecified - thermal storage 63 are an overload introduction to the high pressure turbine part, a condensate backwash, a feedwater side by

High-pressure preheaters and a throttling of the bleed steam lines to the high-pressure preheaters.

In this case, throttling of the high-pressure turbine control valve 63 controlled by the block guide 61 permits the targeted "call-off" of the feed water 41 or water vapor 41 immanent energy, whereby a targeted power change in the secondary circuit 3 - in the context of frequency control - is possible.

Is from the - described here by way of example - thermal storage 63, i. the throttling of the high-pressure

Turbine control valve 47, has been retrieved for the required power change in the frequency control energy / power, so this thermal memory 63, 47 - if necessary level or filling level depending - be filled again.

This is done - also controlled by the block guide 61 - by the additional or increased natural gas furnace 20 in the solar circuit 2, whereby additional thermal energy is introduced into the thermal oil 13.

Via the heat exchanger 40, this additional energy input is transferred to the secondary circuit 3 and is available there for the replenishment of the used thermal storage 63, 47. The throttling 47 is returned to its original state by block guide 61 - and the thermal reservoir 63, 47 is filled again. As FIG 1 shows, be it - via corresponding line ^¬ compounds 62 - the block guide 61 in particular, the performance of the solar panel 30, the operating state of the gas ^¬ lights 34, the state of the throttling 35 and the power generated from the power plant 1 31 as well as the Mains frequency 32 of the power network 33 transmitted.

As FIG 1 further illustrates, then the control of the natural gas firing 20 - via control / regulation of the natural gas flow 22, 73 - and the throttling of the high pressure

Turbine control valve 47 - via the control / regulation of the high-pressure turbine control valve throttle 47, 72- also through the block guide 61. That is, the system 1 in the frequency or primary and / or secondary controlled Lastfolebetrieb 71 - after automatic specification of the load distributor 14th - be driven. The plant 1 or the turbine 42 is in order to power control, i. in modified sliding pressure mode with throttled valves, driven.

In the solar thermal power plant 1, the achievable power is limited only by a determined optional power 96, i. a maximum mobile power of the power plant 1 as a function of the state of individual power-limiting units (for example, feed pumps in operation).

Mode of operation of the power plant 1 in the "load setting mode" 71 FIG. 2 schematically illustrates the power following mode / load setting mode 71 or the corresponding power range 80 of the power plant 1 for the power ^follow-up mode b or. 71. possible by the system 1 operating power sequence b and 71, the system is in modified variable-pressure operation with ge ^¬ throttled valves is driven. Corresponding performance curves or the operating behavior are or is shown in more detail in FIG.

As initially shown in FIG. 2, the power range (power window / "range of adaptability") 80, in which the power plant 1 can be automatically power-controlled, that is to say in the "load setting mode" 71, is subject to certain restrictions. Within this power ^window 80, the Leistungssoll ^¬ value (setpoint) 70 of the system 1 must be in order to be automatically power controlled. For this purpose, the boundaries 90 of the power window 80 are connected as a limitations on a power ^¬ set point adjuster (not labeled).

Downwardly the power window 80 is initially limited by the performance of the currently available primary power 81 plus the power from the minimal mög ^¬ union feuerbaren amount of natural gas 82; At the top, the power window 80 is initially limited by the power from the current available primary energy 81 plus the power from the maximum possible amount of flammable gas 83. Further, at the lower limit 90 of the power window 80, a natural gas fire amount is provided to achieve the economic optimum 86 , That is, the lower limit 90 of the Leis ^¬ tung window 80 shifts by this - considered economic boundary conditions - amount upwards.

To be automated power control capable, be a lower Leis ^¬ tung reserve 84 and an upper power reserve 85 is built ^¬ at the boundaries 90 of the power window 80th That is, the power window 80 decreases (further) by this lower or upper power reserve 84, 85.

These power reserves 84, 85 ensure that the

Power plant 1, as long as it is within these "reserve limits" 91 (lower limit of the power range / window in the "load setting mode"), 92 (upper limit of the power range / window in the "load setting mode") is driven, ie the setpoints are set within these limits 91, 92, quiet is controllable.

The lower power reserve 84 is composed of a reserve for underfiring at power ramps, a damper reserve, a reserve for unloading the vapor storage and the load control reserve and the reserve for the primary regulation; the upper power reserve 85 is composed of a reserve for overshoot at power ramps, the damping reserve, a reserve for steam storage loading, and the reserve for power control and the reserve for the primary control.

A power increase or a power reduction of the plant in the "load setting mode," write the steam are pressure increased or decreased accordingly. This requires a entspre ^¬-reaching, adequate amount of reserve power information for the required ^¬ celled to driving power ramp provided ^¬ the. also for the power control must be maintained in a specific power ^¬ reserve, resulting from the requirements of power control of the turbine 42 and the secondary control. This power window 80 may lie within which the target value 70 of the plant 1, is dynamic, ie it moves during the operation of the power plant 1 in depen ^¬ dependence of - fluctuating or changing - available primary energy 10, 93. If more primary energy 10 available (increased sun exposure), the power window 80 shifts upwards 94 represents less primary energy (cloudiness) available, shifts s I down the performance window 95. The achievable power of the power plant 1, "Ranks of Operation" 100, is limited only by a determined optional power 96, ie a maximum drivable power of the power plant 1 depending on the state of individual power-limiting units (eg feed pumps in operation). . After below the traveling performance of the system is 1 le ^¬ diglich limited by a maximum (minimum) Last 97 wel ^¬ che for stable operation of the plant 1 at least emergency is agile.

Only when the power window 80 and the determined Fen ^¬ tergröße falls below a predetermined minimum range, for example, by the fact that the power based on the primary heat supply 10 is already the maximum system power or optional power approaches 96, the system 1 is to the actual ^¬ value tracked and load distributor influence or primary / secondary control influence switched off (actual operation 74). As FIG 1 shows, the power plant 1 by - part of the

Load distributor 14 - Specification of the (power) setpoint, MWel, 70 driven. From this predetermined desired value 70, corresponding setpoint values for the natural gas firing control 73 and the turbine control 72 are determined - and the system 1 is regulated or driven accordingly.

For information, the limits 90 of the current power window 80 are also transmitted to the load distributor 14. FIG 3 shows in curves the power ranges and the operating performance of the solar thermal power plant 1 in actual operation a, c or 74 and in the power following mode b or 71 ("load setting mode")

Curves in [%] (axis 105) over time t (axis 106) angege ^¬ ben. The curve 101 shows the course of the power available through the primary heat source / supply 10. The curve 104 shows the profile of the (power) desired value of Appendices 1 ^¬ ge; Curve 107 shows the actual power output of system 1.

During the operating phases a and c of Appendix 1, the so ^¬ larthermic power plant 1 in the usual actual operation 74 - driven by the surgeon by hand -. According to the related to available power from the primary heat source / feed method 10 of the target value 70 of the plant 1 that is the target value ^¬ 70 follows the course 1 of the primary energy 10, 101 is set.

At time A, the power plant 1 is operating in the Leistungsfolgebe- b and 71 offset, in which the system is operated until the time point ^¬ B.

At the point in time A of the onset of the power-following operation 71, the power window 80 "opens" with the lower power window limits 102 and 91 shown in FIG. 3 and the upper power window limits 103 and 92, respectively. The setpoint becomes approximately centered at time A . the Leis ^¬ tung window 80 driven As FIG 3 also shows, shifts with changing the per ^¬ weils currently available "primary energy" 10, 101, the power window 80, within which the target value 70 - for ensuring the power control 71 in the solar thermal Power plant 1 - may lie (curve C), up or down.

This is associated with an automatic adjustment of the possible setting range of the setpoint adjuster. As FIG 3 shows, a current setpoint 70, which suddenly above the upper limit 103, 92 of the power window 80 lie ^¬ gene would result a reduction in the primary energy 10 (point G), adapted accordingly by the setpoint generator fits, ie it is automatically guided by the sinking upper limit 103 down (course / phase e).

As soon as, due to a change or increase in the primary energy 10, the upper limit 103 moves upward again (point H), the setpoint is initially left at the level at point H until a new current setpoint value 70 is specified becomes (point D). The same also applies to current setpoint values 70 that are suddenly below the lower limit 102 of the performance ^window 80.

As shown in FIG. 3, a current setpoint value 70, which as a result of an increase in the primary energy 10 would suddenly be below the lower limit 102, 91 of the power window 80 (point E), is adjusted in accordance with the setpoint adjuster, i. it is automatically guided upwards by the rising lower limit 102 (course / phase d).

As soon as, due to a change or reduction of the primary energy 10, the lower limit 102 shifts downward again (point F), the desired value 70 is initially left at the level at point F, until a new current nominal value is reached 70 is specified (point D).

At time B, the plant 1 leaves the Leistungsfolgebe ^¬ drive b and goes back to the actual operation c or 74 on. The power window 80 "closes." The set point 70 directly follows the primary energy 10 again.

Although the invention has been further illustrated and described in detail by the preferred embodiments, the invention is not limited to the disclosed examples, and other variations can be derived therefrom by those skilled in the art without departing from the scope of the invention.

Claims

claims

1. Method for a power control and / or Frequenzbzw. Primary and / or secondary control in a solar thermal steam power plant (1) with a non-freely adjustable primary heat source (10) and an additional heat source (20) and with at least one thermal energy store (63, 47),

characterized in that

using the additional heat source (20) in a primary circuit (2) of the solar thermal steam power plant (1) the at least one thermal storage (63, 47) in a secondary circuit (3) of the solar thermal steam power plant (1) is filled.

2. The method according to claim 1,

characterized in that

the primary heat source (10) is solar energy and / or that the additional heat source (20) is a natural gas firing (20).

3. The method according to at least one of the preceding claims,

characterized in that

the additional heat source (20) has a plurality of fragmented heat ^¬ sources.

4. The method according to at least one of the preceding claims,

characterized in that

the additional heat source (20) a rapid heat input into the primary circuit (2) circulating a heat transfer medium (13), and in particular a thermo-oil (13), made ^¬ light and / or that the additional heat source (10) over a wide Area is regimentable.

5. The method according to at least one of the preceding claims, characterized in that

a plurality of using the additional heat source (20) refillable thermal energy storage (63, 47) in the secondary circuit (3) of the solar thermal steam power plant (1) are present.

6. The method according to at least one of the preceding claims,

characterized in that

the at least one thermal energy store (63, 47) is based on a process medium (41) circulating in a secondary circuit (3), in particular on an energy store immanent in water vapor.

7. The method according to at least one of the preceding claims,

characterized in that

the at least one thermal energy store (63) is a Dros ^¬ tion of a high-pressure turbine control valve (47), an overload introduction to a high pressure turbine part, a condensate backwash, a feedwater side bypass of Hochdruckvor ^¬ warmer or throttling of bleed steam lines to Hochdruckvorwärmern.

8. The method according to at least one of the preceding claims,

characterized in that

the filling of the at least one thermal Energiespei ^¬ chers (63, 47) depending on a degree of filling (level) of the at least one thermal memory (63, 47) takes place.

9. solar thermal steam power plant (1) with a not freely adjustable primary heat source (10) and an additional heat source (20) and with at least one thermal energy storage (63, 47),

signed with

a data processing means (64), in particular a per ^{¬-programmed} processing unit (64) which is set up such is that at least one of the preceding method claims is feasible.

10. Solar thermal steam power plant (1) according to at least the preceding claim,

in which the data processing means (64) is part of a block guide (61) of the solar thermal steam power plant (1).