DE1751226A1 - Gas turbine power plants heated by nuclear power or fossil fuels - Google Patents

Description

You oh nuclear power baw. foopile fuels heated gas turbine power plants

The present invention relates to e'.η -by-.nuclear force or fooaile fuels heated Gacturbinonkraftwerk, vorzugoweioe with GOp alu working medium, consisting of a heat source, gas turbine, Recuperative warning devices, compressors and coolers. He, iat Has already been proposed several times, thermal energy e.g.:; o Lohe, die Fuels are obtained with the help of gas turbine processes to convert ■ electrical energy. In addition to other districts

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PLA 68 / 11TjT ₇₅ - | 226

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With its favorable critical pressure and temperature values, the relatively inert Gaa GOp has already been considered several times as a working medium for such a gas turbine process . See for example the magazine "Journal of Engineering for Power ¹¹ April 1967, page d'l ^ - ^ 36 as well as the not yet known patent applications TLA 66/147; $, Akt.Z .: S 1ü4 720 VIIIc / 21g as well as PIA 67 / 1540, Akt.Z .: S 112 375 Ia / Hh and PLA 67/1562, Akt.Z.: S 112 663 Ia / 46i '. In the gas turbine process mentioned in the first reference, a condensation of the working medium takes place Compressor sucks in a mixture of liquid and gas and thus the occurrence of cavitation phenomena must be feared. The patent applications mentioned further show gas turbine circuits with recuperative heat exchangers, which have great differences in the specific heat of the working medium on the high and low pressure side, which is why The overall efficiency of the systems is disadvantageous, as a result of which part of the profit is consumed which can be achieved when the compressor is required through the high density of the working medium.

The present invention is based on the problem of efficiency of gas turbine systems with a compact design without the complication of reheating, such as it has also been proposed to increase. It was in particular to power plants with sodium or gas cooled Nuclear reactors are intended, but also other gas turbine systems, since the heating method itself determines the mode of operation of the cycle

10982 1/037 9

ORIGINAL

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unaffected. According to the invention, the mean specific heat of the working medium on the high pressure side of the recuperative heat exchanger is more than 5 $> higher than on the low pressure side, and at least two compressors are provided, two of which are connected as partial flow compressors at different temperature levels on the high pressure side of the recuperative heat exchanger, and are the density of the gaseous working medium in the intake port of each compressor is at least 100 kg / m. The high-pressure gas coming from the compressors is thus fed to the recuperative heat exchanger in two partial flows. For this purpose it can for example be provided with a tap in its pipe / mangle system, but it can also have separate pipe coils for both partial flows, each of which is compressed by its own compressor. By guiding the high pressure gas in this way, the large difference in the specific heat of the working gas on the high and low pressure side is compensated and the efficiency is thus increased. Despite the additional compressor output required for the partial coolant flow compared to previous systems, the heat requirement of the overall system is so greatly reduced that even with turbine inlet temperatures of only 500 ^° G, thermal efficiencies of over .40 " are achieved in the turbine process The supercritical suction condition of the gas - preferably COp upstream of the compressor - has the advantage that power control can be achieved in a simple manner by regulating the weight throughput by shifting the temperature at the cooler outlet.

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PLA 68/1177

There is no risk of liquefied gas occurring, since, as can also be seen from FIG. 2 a, the process is supercritical Area of gas remains.

Figures 1 to 4 show various circuit examples to illustrate the present inventive concept. Each other Corresponding components are always provided with the same reference numbers.

FIG. 1 shows an example of a circuit for a ^{sodium-heated CO ^ gas turbine system with} partial flow and pre-compression. The actual heat source is a sodium-cooled nuclear reactor system (not shown). With the aid of the heat exchanger 10, the heat generated in the reactor process is transferred to the gas circuit; the corresponding temperatures and pressure conditions are shown at the respective points in the circuit. The heated in the heat exchanger 10 gas stream with a temperature of 500 C and a. A pressure of 300 ata reaches the drive turbines 13 and via two valves P 30 and 31 in two partial flows.The turbine 14 is the main turbine and is used to drive the compressors 16 and 18 as well as the power generator 15. The auxiliary turbine 13 drives the compressor 17. According to an expansion of the working gas at 57 ata in the turbines 13 and 14 passes the same to a temperature of 320 ⁰ C for Rekuperativwärmetau- • shear 19 "releases its residual heat there to the flowing back to the heat exchanger 10 coolant from and engages with a temperature of 85 ⁰ C. to the cooler 22. After cooling to 35 ^° C., it arrives at

10 9 8 2 ^ / m IA, - ⁴ - a «, obkkNAL ^{MU / Kr}

PLA 68 / 1.177 ■ ''

the pre-compressor 16 driven by the main turbine 14. Behind it, about $ 30 of the working medium is branched off and led to a first partial flow compressor 17, while the other partial flow of 70 $ reaches the compressor via a further cooler 21. The working medium leaving the compressor 18 flows via a non-return flap 33 through the coils 20 of the recuperative heat exchanger 19. The inlet temperature is 68 ^° C. The partial flow coming from the compressor 17 has a higher temperature because it has not passed through the second cooler 21, namely 190 C and is fed to the high pressure coils 20 after passing through the non-return valve 32 at point a. In the upper half of this package, partial flows are again combined to form the total working medium flow and return to ^{the heat exchanger 10 at a temperature of 273 °} C. and a pressure of 305 ata.

The valves are for this, described case - normal operation 37 and 36 closed, valves 30, 31 »32 and 33 each

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but open ·. In the case of a required Turbinenschnell- 'i rschlusses the bypass valve 36 is opened. If partial load is to be run, the auxiliary turbine can be switched off by closing the valve 30. To restart the same, the valves 30 and 37 are opened in a controlled manner, the valve 37 acting as a bypass valve and the auxiliary cooler 23 an impermissible increase in temperature prevented during start-up.

A somewhat simpler circuit is shown in FIG. In

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this has been dispensed with the pre-compressor 16 and the cooler 22. Here, too, is a sodium-heated _{CO 2 -Uioine system.} The division into partial flows takes place before entry into the cooler 21, 30 #, arrive via the valve 35 and the compressor 17 via the check valve 32 with a temperature

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temperature of 197 C to inlet a in the tube coil package 20 des

Recuperative heat exchanger 19. The greater part of the working medium flows through the cooler 21 and reaches ^{the compressor 18 and at a temperature of 33 °} C. and a pressure of 90 ata

from there at a pressure of 310 at and 68 ^° C. to the lower end of the tube coil package 20. The partial flows recombined inside the tube coil package 20 return to the heat exchanger 10 ^{after passing through the heat exchanger 19 at a pressure of 305 at and 237 ° C.} For the normal operation described here, the valves 35, 32 and 30 are therefore open, the latter being able to be regulated, for example. The valves 34, 36 and 38, however, are closed.

P In partial load operation, in turn, the Teilströmverdichter 17 and the power turbine 13 by closing the valve · '30 off '"■ are switched when the entering there increase in Rekuperatoraustrittstemperatur to be verh'indert on the Hochdruckseit ^^. In this case also include the valves ^': 35 ^{un (i} 32 is closed for the restart of the Teilstromve ^ dibhters 17, the valves 38, 35, 34 and 30 in a controlled Wei'se · £ ^ & Opens are, in which case the cooler 21 in the function of the.' Figure ¹ -ic ^ u '

109821/0379 " ⁶ ' ^{MU / Kr}

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illustrated auxiliary cooler 23 takes over. After completion During the start-up process, the valve positions described for normal operation prevail again. As in Figure 1 is also for the bypass valve 36 fully opened with the tendon key.

In contrast to the examples mentioned above, FIG. 3 shows a circuit in which a nuclear reactor.11 serves as a direct heat source for the gas turbine cycle. The working fluid of the gas turbine is also the coolant for the nuclear reactor; A separate primary circuit, for example with sodium ™, is therefore dispensed with here. According to application PLA 66/1473 mentioned at the beginning, the coolant heated in the nuclear reactor does not reach the turbine directly, but first flows through the recuperative heat exchanger 19; the working fluid is expanded in the turbine H before the coolant enters the reactor 11. ensures that the core reactor is not subjected to the maximum pressure of the system. In addition, the distribution of the working medium flow according to the flow of the recuperative heat exchanger 19 - _f j is provided, 25 f « reach the partial flow compressor 17, 75 i ° via the cooler 21 to the compressor 16. The merging in the tube bundle 20 des heat exchanger is 19 as in the previous example. after leaving this heat exchanger, the working medium passes at a pressure of 300 at and at a temperature of 436 ⁰ C to the turbines H and 13 and the same after passing through at a pressure of 120 and 334 C returned to the nuclear reactor as coolant.

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For normal operation, the valves 50, 35 and 32 are open, the valves 36 and 34 are closed. During partial load operation, the partial flow compressor is switched off again; to restart, valve 35 is partially closed and valve 36 is opened for mixed cooling. The bypass valve 34 and the valve 30 are opened approximately simultaneously. After reaching the final speed of the turbine 13, the valve 34 is closed again and the valve initially described state for the m normal operation re-established, so that the conveyed by the compressor 17 partial flow can enter the Rekuperativwarmetauscner.

Another circuit example for the simultaneous use of ■ -des Working gas as reactor coolant results if one deviates of Fig. 3 applies a second expansion turbine after the reactor. This enables a greater temperature difference at the reactor between inlet and outlet. Fig. 4 shows such a direct circuit with two-stage relaxation, Vorver-P seal and partial flow compression in the TS diagram.

Figure 5 shows how such a gas turbine system can be switched with a fossil-heated heat source. The furnace is denoted by 12. The heat is transferred to the gas turbine circuit in the heat exchanger 121. The heat exchanger 122 im Heating gas flow is used to preheat the air for the furnace 12. An air preheater connected in series serves the same purpose 123, through which part of the working gas flows. The '

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BAÖ O8J6INAL

PIA 68/1177

The circuit is otherwise exactly the same as in the previous examples. Only a partial flow of about 15 $ with a pressure of 92 ata and 120 ⁰ G is branched off from the recuperative heat exchanger on the low pressure side at b, passed through the air preheater 123 and fed back into the cooler 21 at 50 C at point b. In this circuit, the start-up control valves etc. are omitted for the sake of simplicity.

From these examples it can be seen that it is proportionate simple circuits. There is no need for intermediate overheating after partial relaxation of the work equipment. Such a one Reheating would be in a sodium-cooled reactor very uncomfortable because the heat transfer to the COp side in the Reheater draft would be bad - very large-volume sodium COp heat exchangers would have to be used for this - also the complicated routing would be a disadvantage, since the COp pipelines would have to be led into and out of the reactor building twice.

At the proposed high pressures and limited expansion ratios of the working gas, the working gas retains a high density at the inlet to the compressors. These can be designed as radial compressors , which do not react to a change in their throughput as quickly as axial compressors with instabilities. Processes with condensation and strong expansion that have become known up to now require axial compressors, at least in the lower pressure stages! in the event of a change in service, in which the business

109821/0379 - 9 - • Mü / Kr

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Weight throughput must be changed by the high pressure stages, forcibly achieve a gas flow that can be below their surge limit. The somewhat poorer efficiency of the centrifugal compressor has little effect on the actually low compressor output and can also be largely mitigated by the use of volute casings with several straight nozzle diffusers. It is useful to mainstream compressor ^ thus has about 70 i "to promote the working fluid, equipped with an adjustable Eintrittsleitvorrichtung and his behavior at partial load is better adapt to the changing COp fabric values.

It is a peculiarity of the COp material properties that the warm-up period in the COp heater decreases during partial load operation. If this reasons eg lying in the reactor should be undesirable, then there is a possibility, as described in the examples to set the separately driven compressor bypass silent and thereby increase the ψ enthalpy rise again. The arrangement of the partial flow compressor on a separate shaft with its own drive turbine also has the advantage that it can continue to run on its own if necessary and thus ensure a certain after-cooling of the system, including the nuclear reactor that is then switched off. ..., ...

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Of course, it would also be possible to use the Teilstrpmverdicht.r 17 to be driven from the main shaft via the main turbine. , Also, can, As already mentioned at the beginning, the partial stiom in its own tube

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109821/03 79 «,«, hau .nspected "

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snake passed through the Rekupera.tivwärmetauscher 19 so that the tapping of the pressure coil bundle 20 is then omitted. It would also be possible to separate this secondary stream through the CC ^ heater and thus a completely independent one To create a secondary flow compressor turbine system that is also at a lower high-pressure side pressure level than the main flow can run, but usually with a kind of overflow, i.e. check valve connected to the main flow on the high-pressure side is. Such a separate bypass system can be started up without a bypass.

The intake temperature of the bypass compressor does not have to correspond exactly to the ■ COp temperature at the transition from the recuperator to the cooler; it can also be reduced, for example by actuating the mixing circuit shown in FIG of the bypass compressor and the overall efficiency 'goes down' somewhat.

Of course, nuclear reactors that use coolants other than sodium, such as helium or CO ₂ , can also be used as heat sources. Gas cooling is an option for fast breeders, graphite-moderated or heavy-water-moderated nuclear reactors. For safety reasons, an indirect circuit is often advantageous, ie a primary-secondary heat exchanger is used. If both sides of a COg-cooled reactor carry the same medium, namely COg-Gae, considerable

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lent leaks between these, for example in the order of magnitude of 1 ton of CO ₂ per day, can be allowed without the fear of contamination of the turbine circuit, since this has a higher pressure than the primary circuit. The indirect switching has the disadvantage of the additional power requirement for the primary circulation fan. With the freedom to choose the secondary pressures optimally, this disadvantage is, however, in many cases largely compensated despite the lower turbine inlet temperature of for example 464 ⁰ C at a COp-cooled fast breeder reactor. (See the TS diagram in Figure 2b). In this example, the recuperator outlet temperature - see point 9 in the diagram - is so low that its distance from the end temperature - point 7 - the bypass flow compression is only moderate or small. This applies in particular because the pressure ratio in the turbine has been increased somewhat compared to FIG It is sufficient to simply mix the partial flows and to go into the heater, ie the primary-secondary heat exchanger, with the mixing temperature 8. Another interesting application of the indirect COp turbine process is obtained with a helium-cooled High-temperature reactor with an outlet temperature of, for example, 750 ^° C. There, the primary-secondary heat exchanger can be designed with a relatively very small heating surface if one is at a temperature of

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PLA 68/1177

590 ⁰ C on the COg turbine is sufficient. At this temperature, the COo turbine process similar to FIG. 2 delivers a power plant net efficiency of more than 40 Si.

In general, it can also be said that C02 turbines are gas-cooled Nuclear reactors also drive the primary coolant circulation vessels Can be used. All of the mechanical The structure of the recuperative heat exchanger 19 and the cooler are based on the patent application already mentioned at the beginning PLA 67/1562, Akt.2 .: S 112 663 Ia / 46f referenced, where the proposal for assembling these apparatuses in a common Prestressed concrete container was made. ... · ■■

11 claims

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Claims (1)

PLA 68/1177 1 »Claims 1.yGas turbine power plant heated by nuclear power or fossil fuels consisting of heat source, gas turbine, ßkuperativwärmetausch, compressor and cooler, thereby characterized in that the mean specific heat of the working medium on the high pressure side of the recuperative heat exchanger is more than 5 ^ higher than on the low pressure side, and that at least two compressors are provided, two of which as partial flow compressors on different ones Temperature levels are connected to the high pressure side of the recuperator heat exchanger and the Density of the gaseous working medium in the intake manifold of each compressor is at least 100 kg / m. 2. Gas turbine power plant according to claim 1, characterized in that each partial flow compressor is driven by its own drive turbine. 3. gas turbine power plant according to claim 1, characterized in that that the compressors are built as radial compressors and, if necessary, in a manner known per se with inlet devices and spiral housings must be equipped with straight pipe diffusers. - H- Mü / Kr 1 0 9 821/0 3 7 9 BAD ORKäiNAL PLA 68/1177 4. Gas turbine power plant according to claim 1, characterized in that - that both partial flow compressors work with approximately the same suction pressure, and that this is preferably via the critical pressure lies. 5. Gas turbine power plant according to claim!, Characterized in that that the suction point for a partial flow compressor before and for the other after "the cooler lies. 6. Gas turbine power plant according to claims 1 to 5, characterized characterized in that C0_ is used as the working medium. 7. Gas turbine power plant according to claims 1 to 6, characterized in that the working fluid is heated in a heat exchanger, the primary side with a fast breeder reactor with sodium, helium or COP cooling or with a graphite-moderated reactor with COp or helium cooling, or with a COp-moderated reactor with COo-cooling is connected. i 8. Gas turbine power plant according to claims 1 to 6, characterized characterized in that a nuclear reactor directly cooled by the working fluid is provided as the heat source. 9. Gas turbine power plant according to claim 8, characterized in that that a power turbine is provided before and after the nuclear reactor. 109821/0379 " ¹⁵ " ^{MU / Kr} PLA 68/1177 1Q. Gas turbine power plant according to Claims 1 to 6, characterized in that a fossil-heated heat source is used as the heat source Boiler system is used, with the residual heat of the working gas cycle is at least partially used for air preheating. 11. Gas turbine power plant according to claim 1, characterized in that that the partial load control of the power plant via the bypass compressor as well as the intake temperature of the main compressor is provided. 1 0982 1/0379 - 16 - Mü / Kr JHSP € CT6D