DE2535996A1 - Peak load turbine with steam accumulator - has series of expansion valves between high and low pressure accumulators - Google Patents

Abstract

A high pressure accumulator is connected by an unloading pipe to a low pressure accumulator. Several steam generating expansion vessels are placed in cascade within the unloading pipe. There is an expansion valve on the inlet of each expansion vessel. High pressure hot water from the high pressure accumulator flashes into steam in the expansion vessels and passes to a peak load turbine. A return pipe runs from the low pressure accumulator through heat exchangers back to the high pressure accumulator. This returns excess water at times of low load. Bypasses round the expansion vessels make it possible to regulate the quantity of flash steam generated. The pressure and temperature in the high pressure accumulator remain constant.

Description

Steam generating plant with steam accumulator The invention relates to a Steam generating plant with storage vessels, in particular a steam storage power plant for the production of top-quality algae. The invention also relates to a steam accumulator, which is particularly suitable for such a system.

There are known steam generating systems, which on the one hand with Gerällespeicher with pressure and temperature reduction during steam extraction and on the other hand with Displacement memories work, where the pressure is almost constant is held, and the water content with the help of a circulation pump at most several times is circulated, the memory contents cooling down after each circulation. at in both storage systems there is a reduction during charging and discharging the temperature of the storage vessel, which limits the service life of the vessel.

The present invention avoids the stated disadvantages and is characterized in that between a high pressure storage vessel of which hot water is taken from the lower part, and a low pressure storage vessel one or more expansion steam generators with upstream in a discharge line Throttle devices are arranged, from which the generated steam via steam lines the steam consumers, in particular turbines, is supplied. More essential Features of the invention are listed in the subclaims. The expansion steam generator can also be used as a steam accumulator in a system according to the invention, albeit as those with a small storage volume.

They mostly have a rising canal and a falling canal and are mainly characterized in that the riser channel is designed as an annular channel is, which is limited by the wall of the storage tank and the internals, and that the fall channel is arranged centrally within the ring channel.

A major advantage of the system according to the invention is therein see that during the operation of the storage system, esp.

during the discharge during the peak energy demand, none large external energy is consumed, such. 3. for circulation pumps, so that the generated Energy can be used in its entirety to cover peak energy requirements. The design described of the steam accumulator is more general Significance, especially for conventional sloping steam storage.

In the following the invention is based on only one embodiment illustrative drawing, which also discloses further features of the invention in more detail explained. There are shown in a schematic representation Fig. 1 a circuit diagram of a storage power plant, FIG. 2 shows a partial circuit diagram for FIG. 1, FIG. 3 shows the overheating of the working steam in the form of a partial circuit diagram, FIG. 4 shows a construction variant of FIG. 3, FIG. 5 a circuit for superheating the working steam, with a device at the same time for keeping the pressure in the high-pressure accumulator absolutely constant, Fig. 6 is a partial circuit diagram of a thermal power plant with reheating of the partial expanded high pressure steam, Fig. 7 shows a known expansion steam generator as a memory, FIG. 8 an expansion steam generator according to the invention, FIG. 9 a another embodiment of the object of FIG. 8, Fig. 10 a further embodiment of the subject of FIG. 8.

The circuit diagram according to FIG. 1 shows a high-pressure storage vessel 1, which is connected to a low-pressure storage vessel 2 via a discharge line. In the discharge line 7 one or more expansion steam generators 3 or 3 'are shown, the lower pressure flash steam generators being indicated by 3 '. A throttle device is located in the discharge line 7 upstream of each expansion steam generator 4 provided. The steam generated in the expansion steam generator 3 or 3 'is over Steam lines 5 supplied to one or more steam consumers 6.

In most cases, a peak load turbine is used as the steam consumer function, but heating steam consumers are also possible in this system. The im Steam consumer 6 cooled steam is condensed and fed to a condensate container and can ultimately be used as condensate from the feedwater preheating of a base load circuit are fed. A return line 10 leads over from the low-pressure storage vessel 2 two heat exchangers 11 in the high pressure storage vessel 1, through which during the The relaxed water collected in the low-pressure storage vessel 2 is passed over during the low-load period the return pump 12 to the heat exchangers 11 functioning as preheaters in the high-pressure storage vessel 1 is returned. To charge this storage vessel 1 is the same in the steam space a steam connection 21 is provided for higher pressure steam.

This charge can also be replaced by the charging nozzles 17 in the water space or be supplemented.

To regulate the amount of steam generated are parallel to the discharge lines 7 bypass lines 8 provided with separate throttle devices 9, which the hot water with almost saturated steam temperature after a throttling a voltage steam generator with relatively low pressure, i.e. relatively high steam generation, fed. This measure allows the steam generation in the individual expansion steam generators 3 'regulate according to need, keeping the hot water consumption optimal can be.

Essential with this circuit list that in contrast to downhill and downhill Displacement storage tank is taken from the high-pressure storage vessel hot water, which does not return to the storage vessel during the unloading process and is in a separate container, which is designed as a low-pressure storage vessel, is stored, so that this vessel requires only small wall thicknesses. In the The discharge of the high pressure storage vessel remains through the withdrawal of the hot water Pressure and temperature of the withdrawn water largely constant, whereby by replenishment from a second pressure vessel (see Fig. 5) also a complete constant holding up too close to complete emptying is possible.

This new type of storage (expansion storage) combines the advantages of the two previously known storage systems (slope storage and displacement storage) by keeping both the pressure and the temperature the same during the discharge as well as the acquisition and management of the expensive circulation pumps is avoided. In addition, the storage vessel, which at the end of the discharge contains only vapor, both during discharge and during charging about the same temperature is kept, what thick-walled storage vessels, this applies to welded high-pressure tanks with large diameters and prestressed concrete tanks as also for pre-stressed cast iron containers, is of great importance. Unless from For reasons of temperature voltage, temperature drops in the storage vessel are tolerable, an expansion of the steam volume can be connected to the normal discharge, whereby the wall heat serves partly for drying or for slight overheating.

In Fig. 2 is a partial circuit diagram of FIG. 1 is shown in which the expansion steam generator 3 'and the low-pressure storage vessel in one component are united. In the remaining details, the circuit diagram is identical to Fig. 1.

In Fig. 3, the overheating of the flowing in the steam line 5 is Steam of the expansion steam generator 3 by a heated superheater with hot water shown. With this construction, the whole is via the discharge line 7 Hot water removed from the high pressure storage vessel "is passed through the superheater 14.

In Fig. 4, a design variant of FIG. 3 is shown at from the discharge line 7 branches off a branch line 15 through which hot water from the high-pressure storage vessel 1 to the superheaters 14 in the steam lines 5 will. The superheaters are switched in such a way that the hot water goes through the superheater first higher pressure and then each lower pressure flows through and finally over a throttle valve 4 is fed into an expansion steam generator 3t lower pressure will.

In Fig. 5 is the overheating of the working steam in the steam line 5 shown by a superheater 14 that of hot water of higher pressure and higher Temperature than the high pressure accumulator 1 flows through from an overheating accumulator 16 will. After throttling, this hot water is used in the high-pressure storage tank Keeping the accumulator pressure constant, fed into the high-pressure accumulator. Through this Measure, the heat from the overheating storage system is fully utilized in a profitable manner. To increase the control capability, there is a bypass line to the superheater 14 18 provided with a control device 19 so that the inlet temperature in the High pressure accumulator 1 can be regulated.

In Fig. 6 is a partial circuit diagram for a condensation turbine with Reheating of the partially expanded steam is shown where the exhaust steam from the high pressure part of the steam turbine with the steam from the expansion steam generator 3 'is mixed in the superheater 14' before it is overheated.

The illustrated principle of the expansion memory can be advantageous use to generate superheated steam. Individual circuits are in the figures 1 to 6 shown by namely the entire removed hot water or only one Partial flow in a superheater or several superheaters connected in series and / or reheaters for the individual pressure stages in the expansion steam generators generated working steam is used. In the use of two separate storage colors this differs for different pressure levels and saturation temperatures Circuit advantageous from all previously known. From the vessel with higher pressure becomes hot water higher Taken from the pressure, which is in the superheater is cooled and throttled into the vapor space of the main storage. With the appropriate Interpretation of overheating, the relative sizes of the two tanks and the two Both the pressure and the temperature in the main memory can be used during pressures of the entire discharge can be kept at completely constant values. Keeping constant the overheating temperature can be reduced by a partial by-pass circuit of the Superheater can be reached. Another advantage over the well-known memory lies in the fact that the storage vessels are almost completely filled with hot water can, while with sloping storage at least 5, but mostly 10 as a steam room are to be provided.

The connection of the discharge line 7 to the high pressure storage vessel 1 can, as is shown in dashed lines in FIG. 5, also in the upper part of the high-pressure storage vessel 1 take place by a line 22 in the interior of the vessel in the water space up to almost to the lowest point of the vessel. This has the advantage that below of the storage vessel no space is required for the discharge line 7, whereby the Foundation is simplified. The discharge line can also go through near the ground the cylindrical wall of the vessel or directly through the bottom vertically be guided downwards. The vessel itself can have a prestressed construction, in particular prestressed concrete construction.

8 to 10 show a steam accumulator as described in the Plant can be used. However, this steam accumulator is more general This is important because it can be used wherever you would otherwise find a sloping steam storage system has used.

Fig. 7 initially shows a standing steam accumulator with circulation-promoting State-of-the-art installations. In this construction is a ring-shaped Fall channel provided, which has a riser channel in its center. This arrangement causes a convex water level, whereby the degree of filling of the reservoir is due the minimum distance between the water level 118 and the discharge line 115 is given is. To prevent water from entering the discharge line, a In the simplest case, baffle plate 117 or a water separator can be provided. When such an accumulator is discharged, the pressure drops, which means from which water steam is generated. Cools by removing the heat of evaporation the water content slowly decreases, creating a temperature difference on the slope wall arises, so that vapor bubbles form on the container wall when the discharge is forced, which slow down the circulation of the water in the storage tank.

This disadvantage increases as the wall thickness increases of the steam storage vessel. In addition, the internals are relatively large Show diameter, since the downcomer has a smaller cross-section than the riser should have. The main features of the memory construction known per se are the cone-shaped fittings r19, the tips of which point upwards.

8 schematically shows a steam accumulator according to the invention.

One can see from the comparison of the two figures that the Internals corresponding to the device according to the invention have a smaller volume to complete. The storage container 102 has an annular channel 101, which acts as a riser channel is formed and is closed on its outside from the container wall. The inner boundary of the annular channel 101 is at least partially through the Internals 103 shown. The internals essentially comprise two parts. In the water room 106 a cylinder jacket 107 is arranged. In the area of the mirror fluctuation of the The memory contents are provided with truncated cone jackets 105, the tips of which are downward point.

The water level 120 in the reservoir has a concavely curved surface on> so that the maximum degree of filling of the memory compared to the prior art with the same minimum distance of the water level from the discharge line 115 can be increased. To get liquid droplets coming out of the rising bubbles the liquid level, from the entrance into the discharge tube 115 to prevent, deflector plates 116 are provided in the steam space 114, which are preferably have a conical shape.

In Fig. 9 a further embodiment of the invention is shown, in which the conical jacket-shaped internals 105 are replaced by a movable part 109 are, which can be retracted telescopically into the part 108 of the fixtures 103 fixed to the container is. The relative movement of the two parts 108 and 109 is controlled by a float 111 controlled, which is connected to the truncated cone jacket 110 of the part 109 in connection. This measure ensures that the water level 120 is always above the Leading edge 121 is in the fall channel 104. The storage tank is discharged via the central discharge tube 113, which is also used to guide the movable Part 109 is used.

In Fig. 10 is a further embodiment of a steam storage device Vessel shown with internals according to the invention. In this construction, the Cylinder jacket 107 of the internals 103 by a support star 122 at its lower End held, with a movable holding structure 123 at its upper end is provided. The frustoconical jacket-shaped internals 105 are on her upper end held by supporting stars 124. The discharge line 115 stirs through the Annular channel 101 into the water space 106 of the reservoir 3 from where it is approximately in the middle of the container is guided radially outwards. Somewhat below the passage of the discharge line 115 through the jacket of the storage container 112, the charging line 125 is provided, which has an annular nozzle 112 in the annular channel 101, which is designed as a charging nozzle is. The steam accumulator is charged through this charging nozzle, and at the same time the circulation of the memory contents is accomplished in the same sense as in the discharge flows. This has the great advantage that even during discharge the memory can be recharged through the charging nozzle 112 without circulation disturbances appear. It is crucial for the stability of the circulation that the water particles be pulled from the surface into the felling space at great speed and be prevented from evaporating by increasing the static pressure. This requires that the cross section of the fall channel is slightly smaller than that of the riser space, wherein the hydraulic cross-section of the downcomer should be as large as possible around the turbulent Ensure flow. These requirements are met by the present invention optimally fulfilled. By arranging the riser channel inside the ring channel comes a concave deformation of the water level occurs during the discharge.

Through the steam extraction at the top central point of the storage tank the ideal case is also achieved that the distance between the extraction line and the water surface remains almost constant, which means that a higher degree of filling can be achieved. Through this that the downcomer is arranged centrally with a smaller flow cross-section, can the internals are designed with a smaller diameter, so that compared to the solution according to the prior art, a material saving occurs.

The charging nozzle (Fig. 10) can be designed as a ring line and thereby enables a very short charging line within the storage volume and is therefore especially for storage with a very short charging time, such as. B. Storage of great advantage for LD waste heat boilers.

Claims (21)

Expectations X Steam generating plant with storage vessels, especially for a Steam storage power plant, for generating peak energy, d a d u r c h g e k e nn z e i c h n e t that between a high pressure storage vessel valley), of which hot water is taken from the lower part, and a low pressure storage vessel (2) one or more expansion steam generators (3) in a discharge line (7) upstream throttle devices (4) are arranged, of which the generated Steam via steam lines (5) consuming steam (6), in particular turbines, is fed. 2. Steam generating plant according to claim 1, characterized in that that parallel to the discharge line (7) bypass lines (8) with separate throttle devices (9) are provided to regulate the amount of steam generated, which the hot water from the high pressure storage vessel (1) directly to an expansion steam generator (3) low Apply pressure (Fig. 1). 3. Steam generating system according to claim 1> characterized that the expansion steam generator (3 ') of the lowest pressure level and the low-pressure storage vessel (2) are arranged in a common vessel (Fig. 2). 4. Steam generating plant according to claim 1, characterized in that that between the low-pressure storage vessel (2) and the high-pressure storage device (1) a return line (10) is arranged with a return pump. (Fig. 1) 5. Steam generating plant according to claim 4> characterized in that in the return line (10) one or more between the recirculation pump and the high-pressure storage vessel (1) Heat exchangers (11) are arranged> those with hot water or steam, in particular Extraction steam from a base load power plant can be heated during the off-peak period (Fig. I). 6. Steam generating system according to claim 4, characterized in that that the return line (10) and a steam connection for higher pressure steam in opens into the upper part of the high-pressure accumulator (1), 7. Steam generating plant after Claim 6, characterized in that in the water space of the high-pressure storage vessel (1) charging nozzles (13) are provided (Fig. 1). 8. Steam generating plant according to claim 1, characterized in that that in the discharge line (7) between the high pressure storage vessel (1) and the expansion steam generator (3) with the highest pressure level as a superheater (14) for the working steam of the Expansion steam generator (3) switched heat exchanger is arranged (Fig. 3). 9. Steam generating system according to claim 1, characterized in that superheater (14) are provided in the steam line (5) to the steam consumer (6), which from a branch line (15) branching off from the discharge line (7) with hot water are supplied (Fig. 4). 10. Steam generating system according to claim 9, characterized in that that the hot water cooled in the superheaters (14) is sent to an expansion steam generator (3 ') is supplied according to the temperature level of the hot water (Fig. 4). 11. Steam generating system according to claim 1, characterized in that that in addition to the high pressure accumulator (1) a separate overheating accumulator (16) of higher boost pressure than the high pressure accumulator (1) is provided, the water side with a superheater (14) for the working steam of an expansion steam generator (3) is connected, the cooled hot water through a throttle device (17) the high pressure accumulator (1) is supplied (Fig. 5). 12. Steam generating plant according to claim 11, characterized in that that to control the superheating temperature of the superheater (14) and / or the pressure in the high-pressure accumulator (1) a high-pressure bypass line (18) to the superheaters (14) and a control device (19) is provided (Fig. 5). 13. Steam generating plant according to claim 1, characterized in that that the steam from the expansion steam generator (3) with the highest pressure the high pressure housing (20) of the steam consumer (6), in particular the turbine, is supplied and the Evaporation of this turbine part with the steam from the expansion steam generator (3 ') the next lower pressure level combined and together in a superheater / intermediate overheater is overheated. 14. Steam generating system according to claims 1 to 19 with as a steam accumulator trained expansion steam generator - and independently of it, characterized by that the steam accumulator internals open the water space subdivided into a rising and falling canal and that the rising canal is an annular canal is formed by the wall of the storage container (102) and the internals (103) is limited, and that the fall channel (104) is centrally located within the annular channel (101) is arranged. 15. Steam accumulator according to claim 14, characterized in that the Internals (103) within the water level fluctuation as coaxially arranged truncated cone shells (105), the tips of which point downwards, and in the water space (106) as a cylinder jacket (107) are formed. 16. Steam accumulator according to claim 14, characterized in that a Part of the internals (103) is permanently installed in the storage container (102) and the other part is arranged axially displaceably to this, the container fixed Part (108) has the shape of a cylinder jacket and in the lower region of the storage container (102) is arranged, while the displaceable part (109) consists of a cylindrical There is a jacket which can be retracted telescopically into the part (108) which is fixed to the container and at its upper end a frustoconical shell (110) which is connected to a Float (111) is in communication (Fig. 9). 17. Steam accumulator according to claim 14, characterized in that the Fall channel (104) has a smaller cross section than the ring channel (101). 18. Steam accumulator according to claim 14, characterized in that the Fall channel (104) has a larger hydraulic diameter than the annular channel (101). 19. Steam accumulator according to claim 14> characterized in that in the annular channel (101) charging nozzles (112) are arranged, the esp. are ring-shaped. 20. Steam accumulator according to claim 14> characterized in that the discharge line (113) is arranged in the drop channel (FIG. 9). 21. Steam accumulator according to claim 14, characterized in that im Vapor space (114) of the storage container (102) coaxial with the discharge line (115) deflector plates (116) are arranged, in particular, of a conical shape.