Power station

Technical field

The present invention relates to a power plant in accordance with the Preamble of claim. 1

State of the art

Accumulator power plants are in the art, for example, made famous in the US 2003/0131599 or US 5,537,822. The Storage of the storage fluid is generally carried out at pressures of about 50 bar, in particular about 100 bar, have to present in the Storage volumes to be able to save as much energy. The US 5,537,822 discloses the possibility power plants, in which a Compressor and an expansion machine together with a both electric motor as a generator operable electric Machine are arranged on a common power train. Furthermore, is disclosed in US 5,537,822 power plants, in which not only a single-screw air storage arrangement, a gas-turbine group is arranged. Such an arrangement can be considered as a disadvantage be because, for example, each time the total compressor power must be operated. In charging mode the air storage system shows Therefore, a small degree of flexibility. Furthermore, it has both the Shafting the air storage device as well as on the shaft assembly the gas turbine group can be arranged an electric machine. The electric machine, which the on the shafting Air storage device is arranged, must for maximum performance the expansion machine and the compressor to be designed. The electric machine of the gas turbine group is however, in the charging mode air storage facility not used. Under the proviso that the Compressor power is greater than the power of the expansion machine, the electric machine the air storage device must be greater be dimensioned than would be necessary for power operation. in the Return remains the machine of the gas turbine group Charging mode, in which the air volume of memory with accumulator fluid is charged, unused. As a result, on the one hand results in the Need to oversize an electric machine, while on the other side of the other electric machine remains temporarily unused.

In addition, it has been found that at pressure ratios over which 50 or even more than 100 are, compressor and / or on a shafting arranged compressor units with high performances which around about 120 MW are, pose significant problems. According to the prior Art turbo compressors for the mentioned pressure conditions therefore only up to a unit output of around 100 to 120 MW in the market. A second observation is that for starting of compressors such Power class up to the rated speed Anfahrvorrichtungen, For example, static frequency converters, with also very high are services required, which can be realized only very expensive can. It is therefore also known in the prior art, Compressors and / or compressor units smaller benefits each separately arrange. However, this means a large number of Components, whereby such a power plant and expensive consuming, is next to implement even with a large amount of space.

In summary it can be stated that in arrangements the state and thus capital employed art resources only be used satisfactory, and the arrangement of components air storage facility only insufficient operating flexibility allows.

Summary of the Invention

It is therefore an object of the present invention, a specify the power plant of the type mentioned, which the Disadvantages of the prior art avoids. It is a particular The object of the invention to provide such a power plant so that maximum flexibility of operation is made possible. According to another aspect of the invention is a power plant specify which with a small number of shafting manages. It should also be borne in mind that easy realized and possible on the market and compressors Combustion engines can be used. According to yet an aspect the invention is such a power plant are given, the entire compressor capacity in charge mode about 100 MW, in particular more than 120 MW, for example in the range of 150 MW to 200 MW is.

Core of the invention is therefore to divide the power compressor and in a power plant to arrange two line shafts, each of which an electrical machine and at least one compressor carries, further wherein a first shafting carries a gas-turbine group, and on a second shafting a relaxation machine work expansion of a storage fluid is disposed.

Under a compressor is in the context of the present disclosure not only to understand a single compressor, but more generally on shafting arranged compressor units. Just like that can it here by several fluidically connected in series Compressors with intercoolers act. For example, a Compressor Throughout the nomenclature used a include low-pressure compressor, which with a intermediate cooler promotes in a medium-pressure compressor, which in turn, through an intermediate cooler into a High pressure compressor promotes. In this case, the low-pressure compressor, the Medium-pressure compressor and the high pressure compressor on a Shafting arranged. A shaft assembly does not mean an imperative that the low-pressure compressor, the intermediate pressure compressor and the high pressure compressor at a joint rigidly coupled Shaft must be arranged. Between the individual Part compressors may on the contrary also gear units be arranged. These are often necessary, for example because of Operating a high-pressure compressor is generally in the present pressure ratios higher speed requires as the Operating a low-pressure compressor. The term includes shafting Therefore, in the context of the present disclosure generally even more Waves, which are connected by means of gears. This makes it possible, in The present invention gas turbine sets, to use expanders, and compressors whose Rated speed of the network-synchronous speed of the electric Machine is different.

In a preferred embodiment, the compressors, Expansion machine, and the gas-turbine group at one end a shafting arranged. Each between a compressor and the gas-turbine group respectively between a compressor and the Expansion machine is arranged an electric machine, which is both a generator and an electric motor operable. In between the electrical machines and the respective work or Engine is arranged in each case a switchable coupling element, which allows a mechanical connection between the electric machine and the compressor or the gas turbine group produce respectively the expansion machine. Thus a electric machine during power operation of the Power plant with the gas-turbine group, respectively the connected expansion machine and operated as a generator. The Connection to the respective compressor is separated thereby. In charging mode the power plant will connect to the gas-turbine group respectively of the expansion machine separately, and there is a Connection with a compressor manufactured; the electric machine is then operated to drive a compressor by electric motor. Both electrical machines can therefore according to the invention both in performance mode and in the charging operation of the air storage facility be operated and used.

According to a first embodiment of the invention, a first Compressor, which is arranged on the first shaft line, and a second compressor which is arranged on the second shaft line is connected in parallel in terms of flow, such that both compressors Ambient air suck and both compressors in a common promote storage volume. According to a second embodiment of the Invention, the first and the second compressor in terms of flow in connected in series, such that one of the compressors, a partially densified Fluid to the other compressor delivers; the other compressor further compressed fluid, and promotes the completely compressed fluid in the storage volume. Advantageously, in the second embodiment between the two compressors, a cooler for the partially compressed Fluid arranged. The first embodiment has the advantage that the Compressors can be operated independently of one another, resulting in a superior flexibility in loading operating results: It is namely to readily possible, only a portion of the compressor capacity use and thus the charging mode to limit the power consumption. The second embodiment has the advantage that the pressure build-up on the two compressors can be distributed such that each of the Compressors must process a reduced pressure ratio.

With the greatest advantage includes the inventive power plant a heat supply, which in the flow path of the Storage volume to the expansion machine is arranged, and to the incoming supply of heat to the expansion machine Storage fluid allows. In one embodiment of this invention is Heat supply, an exhaust gas heat exchanger of the gas-turbine group, in the exhaust heat of the gas turbine group beneficially to the storage fluid Gets transferred. This, however, almost no further action mandatory to each simultaneous operation of the gas turbine group and the Expansion machine. Therefore, an alternative Embodiment of the invention proposed, in which the flow path the storage volume to a relaxation machine of the Gas turbine group independent heat supply device is arranged. This independent heat supply device is in a development of the arranged invention as directly in the flow path Firing run. In a second further development of the Invention is the independent heat supply as Heat exchanger formed with an external firing. On significant advantage of the first embodiment here is the low equipment expense. A disadvantage is that the expansion machine with is applied aggressive flue gases. Here, despite the larger apparatus required a significant advantage of the embodiment with an indirect firing system: The expansion machine is not aggressive combustion gases acted upon, and it is therefore possible use a relatively simple and inexpensive machine, as For example, a standard steam turbine, which for these Use only small changes needed. Furthermore, permits indirect firing system, the storage fluid in the expansion machine so relax far that the outlet temperature of the storage fluid from the expansion machine to ambient temperature or even including falls, what with the least Abströmungs-heat losses accompanied. This is possible because not of the underflow Dew point of corrosive flue gas components into consideration must be taken. If, however, a direct firing is used as an expansion machine must be selected, which is resistant to corrosive fumes, which ultimately much more expensive components to achieve the same service life requires. Even then, care must be taken that the Temperature of the working fluid as it exits the not expansion machine below the dew point of the Flue gas components fall because otherwise serious Corrosion damage. The outlet temperature of the Expansion machine is then, for example, over 130 ° C, resulting in Rates increased exhaust gas heat losses result.

The to be placed here Wärmezuführvorrichtung is particularly well the use of low temperature heat, such as solar heating or other at a low temperature level of the heat produced because the inflowing reservoir fluid is at a low temperature.

In a preferred embodiment of the invention which is on a Shafting in the form of the gas turbine group or the Expansion machine disposed drive power greater than or at least the same size as the capacity of the same on the Shafting arranged compressor. This results in a best possible adjustment of the power size of the electric machine as well as the necessary electrical equipment, such as Transformers, switching units, and Anfahrvorrichtungen, both the generator and the electric motor operating the electric machine.

Preferably, the compressors are dimensioned such that they are Able, with pressures above 50 and in particular greater than 100 to be operated. That is, at standard ambient conditions is the pressure of the stored fluid and more than 50 especially more than 100 bar. In a preferred embodiment of the Invention, the entire compressor capacity of the two Compressors together more than 100 MW and in particular more than 120 MW, for example, 150 to 200 MW. The on a single Shafting installed compressor capacity is preferably below of approximately 115 to 120 MW, for example, at 50 to 110 MW.

Further advantageous embodiments and modes of operation of the inventive power plant will become apparent to those skilled in the light of the embodiments described below and the Subclaims.

Brief Description of Drawing

The invention will be illustrated based on the drawing Embodiments explained in more detail. show in detail

1 shows a first inventive power plant;

2 shows a second embodiment of an inventive Power plant; and

3 shows another example of an advantageous embodiment of a inventive power plant.

The exemplary embodiments and the drawings are to be purely instructively understand and are not intended to restrict the Claims marked the invention are used.

WAYS OF CARRYING OUT OF THE INVENTION

A first embodiment of an inventive Power plant is shown in FIG. 1 The power plant comprises a first shafting 1 and a second shafting. 2 On the first shafting 1 is a gas turbine group 11 and Compressor 13 is arranged. The gas-turbine group and the compressor are arranged at the two ends of the shaft assembly. Between the Gas turbine group 11 and the compressor 13 is an electric machine 12. which both an electric motor and a generator operable. Switchable coupling elements 14 and 15 make it possible the electric machine either with the gas turbine group 11 and the Compressor 13 mechanically connect. The gas turbine group 11 is present as a simple, familiar to those skilled readily Gas turbine group shown. It includes a compressor 111, a Combustion chamber 112, and a turbine 113. Of course, here find a different type of a gas turbine group use, For example, a gas turbine group with sequential combustion, as it is for example from EP 0620362 known. On the second Shafting 2 are at the two ends of the shaft assembly a Expansion machine 21 and a compressor 23. In between the expansion machine and the compressor is both regenerative and motorized operable electric machine 22. By means of the coupling elements 24 and 25 is the electric machine either with the expansion machine 21 and the compressor 23 mechanically coupled. The compressors 13 and 23 are presently shown as simple turbo compressors; without Limiting the invention, the compressor is also a have intermediate cooling, or there may be several in series connected compressor with or without terms of flow intermediate coolers can be arranged on a shafting. Also, of course, within a shafting between the electrical machine and the compressor and / or the Relaxation tool or the gas turbine group in the Those skilled in the known manner, a present Embodiment not shown translation or be such that the speed of the reduction gear arranged Power or working machine of the rotational speed of the electrical machine is different. Especially in times of high energy demand, the Power plant operated in the power mode. It is at least one of the coupling elements 14, 24 are closed, the corresponding mechanical connection is thus produced; the coupling elements 15 and 25 are opened, the corresponding mechanical connection is so separated. To drive the electric machine 12 is the Gas turbine group 11 is operated in a known per se. in the Flow of the gas turbine group 11 is downstream of the turbine 113 For example, a familiar to the expert se arranged HRSG 43rd The arrangement of the HRSG 43 is optional and is not in itself relevant to the invention. In the heat recovery steam generator 43 is to se known manner by means of the exhaust gases in the gas-turbine group Residual energy contained generates steam, which in turn itself known manner to drive a steam turbine or other Process purposes can be used. It is also well known, initiate the steam generated therein to the gas-turbine group and in the Turbine of the gas turbine group producing work to relax. to drive the electric machine 22 is the expansion machine 21 operated. A stored in the storage volume 3 under pressure Storage fluid via the actuator 34 to the expansion machine 21 directed and expanded there to perform work. flows through the storage fluid on the way from the storage volume 3 for expansion machine 21 a heat supply and is heated thereby. The Heat supply is present as heat exchanger 41 with a external combustion device 42 is shown. The benefits that off this arrangement over a direct firing of Storage fluid result, have already been set forth above. Of the Heat exchanger 41 is, moreover, particularly well suited for use of low-temperature heat such as solar heat or other at a low temperature level of the heat produced as the inflowing reservoir fluid is at a low temperature, and in Generally not high inflow temperature for the require expansion machine 21st On the contrary it is of advantage, the temperature limit at the inlet of the expansion machine 21, for example, to a temperature of less than 500 ° C or less than 550 ° C. This also facilitates the use of commercially available Cheap relaxation equipment such as Steam turbines, which are not extremely high inlet temperatures are designed. Because of the limit of the inlet temperature may be at the use of expensive and complex to be processed high-temperature resistant materials are dispensed. The Warming of the storage fluid advance of relaxation in the Expansion machine 21 increases the mass-specific Enthalpy of the storage fluid, thereby increasing the achievable Power output with the data stored in the storage volume 3 Storage fluid increases. In times of high energy and availability of corresponding low electricity prices, for example, overnight, is the power plant operated in the charging mode. It promotes at least one of the compressors 13 and 23, a compressed storage fluid to Storage volume 3. The actuator 34 is closed and the actuator 33 opened. The compressors 13 and 23 can operate individually will. This allows a convenient staging of power the power plant is in charge mode. A particularly advantageous Regulatory option arises when the compressors 13 and 23 have different power ratings. For example, if a the compressors has twice the power as the other, so it is possible power consumption of the power plant in the ratio 1: 2: altering 3, wherein the compressors in each case in the nominal operating point work. Downstream of the compressors are check valves 31 and 32 arranged that a return flow of fluid through the compressors prevent. Preferably promote and compress the compressors 13 23 and ambient air, the stored under pressure in the storage volume 3 becomes. Downstream of the compressors 13, 23 and upstream of the Storage volume 3 according to a preferred embodiment of the Invention, a cooler 36. By means of the cooler 36, the while the largely adiabatic compression heated fluid to be cooled down before it is supplied to the storage volume of the third For loading operation is at least one of the coupling elements 15 and 25 closed, and the coupling elements 14 and 24 are open. At least one of the electric motors 12 and 22 is electro-power and drives a compressor 13, 23 to, whereby the storage volume is charged with 3 storage fluid, which then again to work expansion in the Expansion machine 21 is available.

Another embodiment of the invention is shown in FIG. 2 As well as the power plant shown in FIG 1 also comprises the power plant shown in Figure 2 two line shafts 1 and 2, on each of which an electric machine 12, 22, a compressor 13, 23 and a gas turbine group 11, respectively an accumulator fluid expansion machine arranged 21st In contrast to the figure in 1 power plant shown, the compressors 13 and 23 fluidly not connected in parallel but in series, such that from the compressor 13 compressed fluid flows to the compressor 23, and is further compressed by the latter. Downstream of the compressor 13 and upstream of the compressor 23 is a cooler 35 for the compressor from 13 partially compressed fluid disposed. Downstream of the compressor 23 is a Another cooler 36 arranged to cool the compressed fluid. in the Exhaust gas flow path of the gas turbine group 11 is in the illustrated Embodiment, an exhaust gas heat exchanger 44 is located. Of the Exhaust gas heat exchanger 44 on the primary side, on the heat-dissipating Side, exhaust gas flows through the gas turbine group. During power operation the accumulator fluid expansion machine 21 is reservoir fluid from the Storage volume 3 through the actuator 34 in countercurrent to the Exhaust gases of the gas turbine group passed through the exhaust gas heat exchanger 44; it takes the storage fluid heat from the exhaust gases on, is this heated and the heated reservoir fluid is work in the Storage fluid expansion machine relaxed. The so maximum attainable temperature of the storage fluid substantially corresponds to the Temperature of exhaust gas at the outlet from the turbine 113 of the Gas turbine group 11. This is modern gas turbine sets typically in the range of about 550 ° C, and is true in almost perfect Way with the permissible inlet temperature of Accumulator expansion machine 21 match. The operation of Power plant in Figure 2 is carried out to perfectly analogous to that in Figure 1 shown and discussed above embodiment. in the Power operation of the power plant, the electric machine 12 and / or 22 operated as a generator. In this case, the clutches 14 and / or 24 are closed, the clutches 15 and 25 are open, and the electrical machines of the engine 11 and / or 21 driven. During operation of the accumulator fluid expansion machine 21, the storage volume 3 is emptied. In charging mode the Power plant to the electric motors 12 and 22 electric motor operated. In this case, the clutches 14 and 24 opened, and the clutches 15 and 25 connect the electrical machines with the compressors 13 and 23 forth. by virtue of the series circuit of the compressors 13 and 23, the Compressors of the two shaft lines not independently operate. That is, the operation of the compressors also requires the operation of the other compressor. During operation of the Compressors is the storage volume 3 with pressure reservoir fluid charged, which then again to work expansion in the storage fluid expansion machine 21 is available. Very convenient and advantageous for the temperature of the exhaust gas of the Gas turbine group downstream of the heat exchanger 44 is measured, and for example, by control interventions on the actuator 34 of the Storage fluid mass flow is set such that the dew point of Exhaust gas is not reached, or a safety margin Dew point of the exhaust gases is retained. Upstream of the exhaust gas heat exchanger 44 or within the exhaust gas heat exchanger can be a be arranged Zusatzfeuerungseinrichtung to the storage fluid, a to provide greater thermal performance. In the example Illustrated embodiment is upstream of the exhaust gas heat exchanger 44 supplementary firing 45 with a fan 46 outside the Flow path of the exhaust gas of the gas turbine group arranged. By Operation of the fan 46 is directed fresh air for supplemental 45 where a fuel can be burned. The flue gases are conducted through the exhaust gas heat exchanger 44, and are also for the heating of the storage fluid in the exhaust heat exchanger 44 for Available. The external arrangement of the supplemental firing 45 with a Fresh air blower 46 has the advantage that the accumulator fluid expansion machine 21 even with heated storage fluid can be operated when the gas turbine group 11 is stationary. This increases the operational flexibility of the power plant considerably. furthermore can also be a not shown exhaust gas bypass for the exhaust gas of the be arranged in gas-turbine group, which allows the exhaust gas of Gas turbine group by forwarding the exhaust gas heat exchanger 44th this has considerable benefits if, for example, with an empty Storage volume 3, the gas turbine set at rest the storage fluid expansion machine to be operated 21st It is then the thermal stress or overload of the power supplier perfused exhaust gas heat exchanger 44 avoided.

The inventive example shown in Figure 3 Power plant is in terms of heat and electrical connections of Gas turbine group 11 and the accumulator fluid expansion machine 21 identical in structure to the power plant shown in FIG. 2 The arranged on the two shaftings compressors 13 and 23 As in the embodiment of Figure 1 in terms of flow parallel disposed, from which, as shown, greater flexibility in operation the power plant resulted. On storage volume 3 is in the here Illustrated embodiment, a shut-off device 37 is arranged. This detail increases the operational flexibility as shown below considerably. The illustrated embodiment allows a Power operation of the power plant even when deflated Storage volume 3. In such an operation are the couplings 14 and 24 the connection of both the gas turbine group 11 as well as the Expander 21 with the electric motors 12 and 22 forth. At least one of the clutches 15, 25 connects a electric machine with one of the compressors 13, 23 ago. In this Mode is the obturator 37 is closed, the emptied or insufficiently filled storage volume 3 is therefore of the Power plant separately. The actuators 33 and 34 are open. From the compressors 13 and / or 23 will be conveyed, compressed air the exhaust heat exchanger 44 to the expansion machine 21 and passed expanded there to perform work. In the exhaust heat exchanger 44, the fluid is heats. It is thus possible, even with the expansion machine insufficient pressure in the storage volume to operate. Furthermore, the exhaust heat of the gas turbine group 11 also advantageous in deflated Storage volume are used. The gas turbine group 11 can therefore also are then operated without problems, when no fluid from the Storage volume 3 is available, and no bypass line for the disposed exhaust gas heat exchanger 44th The cooler 36 is in this Mode with advantage out of service.

The embodiments described above illustrate the one hand, high operational flexibility of the inventive power plant. Furthermore, it is clear that the utilization of the inserted Resources is far better than in the prior art known power plants. In particular, each of the electrical Machines both in performance mode and in the charging mode of Power plant to be operated. The gas turbine set allows also to generate power when the storage volume 3 has been completely emptied. In light of these will open up the Skilled readily further possible embodiments of the Invention. open more savings and improvement potentials by the fact that the electrical machines, both on the Shaft lines are arranged, a common electrical can use equipment. This is for the power plant with two shaft lines, for example, only one power connection transformer, so-called "step-up transformer", and a starting device, For example, a static frequency converter is required. This reduces the investment costs and the use of resources on. Also the space requirement is considerably reduced, because a more compact construction is the entire power plant possible.

LIST OF REFERENCE NUMBERS

1 first shafting

2 second shafting

3 storage volume

11 gas-turbine group

12 electric machine

13 compressor, compressor, centrifugal compressor

14 coupling element, clutch

15 coupling element, clutch

21 expansion machine, Speicherflui expansion machine

22 electric machine

23 compressor, compressor, centrifugal compressor

24 coupling element, clutch

25 coupling element, clutch

31 checking member, non-return valve

32 checking member, non-return valve

33 actuator, valve

34 actuator, valve

35 Cool

36 Cool

37 shutoff

41 heat exchanger

42 firing

43 HRSG

44 Exhaust Gas Heat Exchangers

45 supplemental

46 Fresh air blower