JPS59195007A - Method and device for warming high-pressure feedwater heater - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application of the Invention] The present invention provides a warming method and a warming device for preventing sudden changes in the temperature of a feed water heater in a steam generator plant.

[Background of the invention]

Conventionally, the water supply system of a steam generator plant has generally been
This is carried out as follows using a device as shown in ri.

After the boiler is turned on, the water in the deaerator 2 is supplied by the boiler water supply pump 4 and the water supply pipe 5 at a flow rate corresponding to the minimum flow rate of the boiler.
The water is then supplied to the boiler. At this time, the water supply in the deaerator 2 is in a vacuum deaerated state and maintained at about 60C. Therefore, the high-pressure feed water heater is also in a state of about 6 (l). When the ventilation state is reached, the amount of water supplied to the boiler increases to a flow rate corresponding to the amount of steam generated by the boiler, but the temperature of the feed water at this time is Approximately 60
It gradually rises from C. After turbine ventilation, with the turbine square tube reduced to about 20%, the third high-pressure feed water heater 6
, the second high-pressure feedwater heater 7 , and the first high-pressure feedwater heater 8 , the feedwater heaters on the low-pressure, low-temperature side are sequentially put into service. In the figure, 1 is a +q condensate pipe, and 3 is a booster pump. 6, 7°8 are the 3rd. Second. 1st
9, 10, 11.12 are the high pressure feed water heaters, respectively. 2nd, 3rd. This is the fourth bleed pipe. 13 is a deaerator circulation pump, 14 is a deaerator circulation pipe, 15 is a feed water pump bypass pipe, 16 is a boiler cleanup pipe, 17 is a boiler water IB pipe, 18 is an auxiliary steam header, 19 is an in-house boiler, 20 The deaerator auxiliary steam pipe 27 is a high pressure feed water heater bypass pipe.

Figure 2 shows the temperature change during the above in-service operation, where tl is the time of ventilation, t2 is the time of addition, t3 is the time of in-service of the third high-pressure feed water heater, and t4 is the time of in-service of the second high-pressure feed water heater. respectively, and T6 is the inlet of the third high-pressure feed water heater! T7 represents the water supply temperature at the inlet of the second high-pressure water heater, and T8 represents the water supply temperature at the inlet of the first high-pressure water heater.

As mentioned above, the inlet temperature of each high-pressure feed water heater, T6+'f
'7 + T8 is 60 at turbine venting point 111
From this state (temperature), the required temperature when the high pressure feed water heater is in service (third high pressure water heater: approximately 130
C. Second high-pressure water heater: Approximately 148C.

First high-pressure feed water heater: Raise the temperature at approximately 1870) t.

In this case, the temperature increase rate is approximately 21
00/H, about 2271r/H in the second high pressure feed water heater,
Approximately 286 tons for the first high pressure water heater? /H Temperature changes rapidly. Therefore, local thermal stress is generated in the ice chamber of the high-pressure feed water heater.

FIG. 3 shows an example of the life consumption rate of a conventional high-pressure water heater. The temperature change rate (third high pressure water heater; approx. 21
0C/H, 2nd high pressure water heater 227tlG/H,
According to the first high-pressure feedwater heater; approximately 2860/H), the life consumption rate of the high-pressure feedwater heater per one cycle of plant start-up and stop is as shown in this figure, and the third high-pressure feedwater heater; approximately 0.011
%, second high-pressure feed water heater io, 013 section, first high-pressure feed water heater; approximately o, o i s%.

As mentioned above, in order to cope with extreme local thermal stress caused by sudden changes in temperature, conventional high-pressure feed water heaters need to be designed and manufactured with a large R section of the spherical water volume, and high-pressure feed water heaters are large. In addition, the number of times the plant starts and stops due to daily start-stop operation, etc. increases, which shortens the life of the high-pressure feed water heater and has a significant impact on the reliability of the entire plant. Furthermore, in the case of ultra-supercritical pressure blunts, which are currently under consideration and planning for practical use, the required water supply temperature will be relatively high, making it increasingly difficult to deal with the thermal stress described above. For the above reasons, reducing the thermal stress of the high-pressure feed water heater has become an important issue in order to put an ultra-supercritical pressure steam power plant into practical use.

[Purpose of the invention]

The present invention has been made in view of the above-mentioned circumstances, and is a warming method capable of preventing sudden changes in temperature of a high-pressure feedwater heater during the period from boiler ignition to high-pressure feedwater heater in-service in a steam power plant (hereinafter referred to as startup process). , and a warming device.

[Summary of the invention]

In order to achieve the above object, the warming method of the present invention preheats the feed water by introducing a high-temperature fluid other than the bleed steam of the steam engine into the water supply system during the startup process of the steam engine, and from the start of ventilation to the feed water heater. It is characterized by suppressing the temperature rise rate (time rate) of the high-pressure water heater until it is in service.

Further, the warming device of the present invention is installed in a water supply system of a steam engine plant, and is connected to a pipe line that introduces high-temperature fluid other than extracted steam from the steam engine into the water supply system, and between the introduced steam and the water supply. It is characterized by providing means for performing heat exchange.

[Embodiments of the invention]

FIG. 4 shows an example of the apparatus of the present invention configured to carry out the warming method of the present invention.

This embodiment is an improvement by applying the present invention to the conventional device shown in FIG. 1, and the members with the same drawing reference numbers as in FIG. They are similar components.

In this embodiment, the in-house boiler 19 or the pond water 3
0 high temperature steam is introduced into the third high pressure feed water heater 6 via the auxiliary steam header 18. 22 is a temperature tA regulating valve provided in the warming steam pipe 21. This temperature control valve 22 is controlled to open and close by a temperature detector 23 provided at the outlet of the third high-pressure feed water heater 6.

When the boiler is ignited, it does not correspond to the boiler minimum flow rate.
Souji 6-Kopu 4, water supply pipe 5. High pressure water heater bypass pipe 27
The water is then supplied to the boiler. At this time, the high-pressure feed water heater side is shut off by the outlet valve 31 and the inlet valve 32 to prevent the feed water from passing through. On the other hand, the high-pressure feedwater heater warming steam (in this embodiment, steam from the auxiliary steam header 18 is used) passes through the warming steam pipe 21 at the time of boiler ignition, and is sent to the third high-pressure feedwater heater 6 by steam pressure. The third high-pressure water heater 6 is warmed. Warming steam that absorbs heat during warming is drained! 7 The water is recovered to the condenser through the drain pipe (not shown) of the third high-pressure feed water heater 6. In addition, the amount of warming steam is adjusted to the target temperature by a temperature detector 23 installed on the water chamber side of the third high-pressure feed water heater 6 and a temperature control valve 22 installed in the warming steam pipe 21. Adjust. When the turbine enters the ventilation state, the amount of water supplied to the boiler increases, but water is supplied with the high-pressure feedwater heater bypassed by the bypass pipe 27, and the load increases by about 10 to 20 inches, causing the target warming temperature of the high-pressure feedwater heater to rise and the in-service When there is almost no difference in the required temperature, the high-pressure feed water heater is switched from bypass to water flow and warming is stopped. When the turbine load reaches approximately 20φ, the third high-pressure feedwater heater 6, the second high-pressure feedwater heater 7, and the first high-pressure feedwater heater 8 are brought into service in this order.

When warming is performed as described above, when the high-pressure feed water heater is switched from the bypass state to the water flow state, a sudden change in temperature does not occur because the high-pressure feed water heater has been warmed in advance. Therefore, there is no risk of locally generating large thermal stress. As described above, the warming method of the present invention preheats the feed water by introducing a high-temperature fluid other than the extracted steam from the steam engine into the water supply system during the start-up process of the steam engine plant, and the water supply power is adjusted from the start of ventilation. Since it is possible to suppress the temperature rise rate (time rate) of the high-pressure feed water heater until the crusher is placed in service, it is possible to prevent the occurrence of excessive local thermal stress due to sudden changes in temperature. .

Still, the apparatus of the present invention, as described above, in a water supply system of a steam engine plant, has a pipe line for introducing high temperature fluid other than the extracted steam of the steam engine into the water supply system, and By providing a means for exchanging heat with the water supply, the method of the present invention described above can be easily carried out and its effects can be fully exhibited.

FIG. 41 is a construction diagram for explaining an embodiment different from the above.

This first example has the same basic structure of the apparatus as the embodiment shown in FIG. 4, and the operating method is also basically the same. The difference from the embodiment shown in FIG. 4 is that each high-pressure feed water heater is provided with a warming steam g21 and a temperature control valve 22, respectively.

As shown in the implementation rows of Figures 4j and 5 shown above, auxiliary steam is used as the feed water heating fluid, and the feed water is preheated by the auxiliary steam using high-pressure supply and a feed water heater. , and if the high-temperature steam flow rate is controlled based on the feed water temperature at the outlet of the high-pressure feed water heater, the method of the present invention can be carried out without significantly increasing the number of main components of the water supply system, and temperature control is easy. .

FIG. 6 shows a system configuration of an embodiment different from the above.

Similar to the embodiment shown in Fig. 4, water is supplied when the boiler is ignited, and the boiler minimum flow rate is from the deaerator 2, to the booster pump 3, to the boiler feed water pump 4, to the water supply pipe 5, to the high pressure feed water heater bypass pipe. Water is supplied to the boiler through 27. At this time, the high-pressure feed water heater side is shut off by the inlet/outlet valve to prevent feed water from passing through. On the other hand, the high pressure water heater warming water is
Deaerator circulation pump 1 already in operation for deaeration of feed water
Water is passed through a warming pipe 25 branching from the deaerator circulation pipe 14, which is the discharge side of No. 3, to the water supply side inlet of the high-pressure feed water heater. This warming water is heated by a potato that introduces superheated steam (auxiliary steam is used in this embodiment) into the warming heater 24 installed in the warming pipe 25, and the amount of heat necessary for warming is obtained and the high-pressure water heater feed water is heated. Water is passed through the side entrance. The warming water that has passed through the high-pressure feedwater heaters 6, 7.8 is recovered to the condenser via the bre boiler cleanup pipe 16 at the outlet of the first high-pressure feedwater heater 8. Further, the amount of warming water is adjusted by a temperature control valve 22 installed in the warming pipe 25 and a temperature detector 23 installed in the water supply pipe at the outlet of the first high-pressure feed water heater 8 so as to reach a target temperature. Ru.

When the turbine is ventilated, the amount of water supplied to the boiler increases, but water is supplied to the boiler while the high-pressure feedwater heater is bypassed. When the load increases (sections 10 to 20) and there is almost no difference between the high-pressure feedwater heater target warming temperature and the required in-service temperature at the high-pressure feedwater heater inlet, warming is stopped and the high-pressure feedwater heater is bypassed. Switched to water flow operation, and when the turbine load reached about 20 inches, the third
The high-pressure feed water heater 6, the second high-pressure feed water heater 7, and the first high-pressure feed water heater 8 are brought into service in this order.

Because the high-pressure water heater is warmed in advance, large thermal stress does not occur.

FIG. 7 shows a system configuration of a further different embodiment.

The basic configuration and operating method of this embodiment are the same as the embodiment shown in FIG. The difference from the embodiment shown in FIG. 6 is that in the embodiment shown in FIG.
In the embodiment shown in FIG. 7, the steam heat-exchanged by the warming heater 24 is collected in the water storage tank of the deaerator 2 as drain.

As in the embodiments shown in FIGS. 6 and 7 described above, a part of the deaerator circulating water is extracted and used as water supply, the supply water is heated by high-temperature steam, and the above-mentioned method is used. By providing heat through a high-pressure feedwater heater and a separate heat exchanger,
Sudden changes in the temperature of the high-pressure water heater can be prevented.

FIG. 8 shows the system configuration of a further different embodiment. This embodiment is the same as the embodiment in FIG. 6 in terms of both the basic system and the operating method. The difference from the embodiment shown in FIG. 6 lies in the installation position of the warming heater 24.

In the embodiment shown in FIG. 6, the warming heater 24 is installed in the warming pipe 25, whereas in this embodiment, the warming heater 24 is installed in the deaerator circulation pipe 14 on the discharge side of the deaerator tooth ring pump 13.

In this embodiment, by heating the entire deaerator circulating water, it can be expected that it can be used not only for warming the high-pressure feed water heater but also for warming the boiler feed water pump.

FIG. 9 shows a system configuration of a further different embodiment.

Similarly to the above embodiment, water is supplied by boiler ignition for a minimum of σlL"4 minutes, from the deaerator 2, to the booster pump 3, to the boiler bottom, to the water-containing pump 4, to the water supply pipe 5, to the high-pressure water supply 7I.
Water is supplied to the boiler via the O-heater bypass pipe 27. At this time, the pressure feed water heater side is blocked by an inlet/outlet valve so that the feed water does not pass through. On the other hand, warming water for the high-pressure feed water heater is supplied to the booster pump 3 and the boiler feed water pump 4.
A portion of the feed water is passed as warming water to the water supply side inlet of the pressure feed water heater through the boiler feed water pump bypass pipe 15 branching from the communication pipe with the boiler feed water pump. This warming water is heated by introducing superheated steam (in this case, auxiliary steam is used) into the warming heater 24 installed in the boiler feed water pump bypass pipe 15 to obtain the amount of heat necessary for warming and to create a high pressure. Water is passed to the water supply side inlet of the water heater. The warming water that has passed through the high-pressure feedwater heaters 6, 7.8 is recovered to the condenser via the preboiler +J-up pipe 16 at the outlet of the first high-pressure feedwater heater 8. or,
The amount of warming steam is controlled by a temperature control valve 22 installed in the warming steam pipe 21 and a temperature detector 23 installed in the water supply pipe at the outlet of the first high-pressure water heater 8 so as to reach the target temperature. Ru.

When the turbine is ventilated, the number of boiler water supply types increases, but water is supplied to the boiler with the high-pressure feedwater heater bypassed.

When the load increases (10-20%) and there is almost no difference between the warming temperature of the high-pressure feedwater heater and the required in-service temperature of the high-pressure feedwater heater inlet, stop warming and switch the high-pressure feedwater heater from bypass. Switching to water flow operation, when the turbine load reaches about 20%, the third high pressure feed water heater 6, the second high pressure feed water heater 7, and the first high pressure feed water heater 8 are brought into service in this order.

This implementation also provides the same effects as the previous example.

FIG. 10 shows a system configuration of a further different embodiment.

The basic concept and operating method are the same as those of the embodiment shown in FIG. 9 above. The feature of this embodiment is that the warming heater 24 is installed in the boiler water pipe 17, and warming water is supplied to the water pump. This embodiment also provides the same effects as the previous example.

FIG. 11 is a chart showing temperature changes in actual use of the present invention, and corresponds to FIG. 2 in the prior art.

t8 to t5 and T using the same drawing reference symbols as in Figure 2.
6 to T8 represent the same meanings as in FIG. If the warming temperature is controlled at approximately 160C in the above embodiment, the high pressure feed water heater temperature will reach approximately 160C during turbine ventilation9. Approximately 9 for heater T6
00/H1 2nd high pressure feed water heater T7 - about 31 C,
/,)-I.

In the first high-pressure feed water heater T8, the temperature changes by approximately 61c7n, and compared to the temperature change width of the conventional technology (see Figure 2), the temperature change width can be made smaller, and thermal stress can be significantly reduced. It is possible to hold it down.

FIG. 12 shows the life consumption rate of the high-pressure feed water heater according to the embodiment of the present invention. As shown in this figure, compared to the lifetime consumption rate of the conventional technology (see Figure 3), the life consumption rate is 1. Second. In any of the third high-pressure feedwater heaters, the life consumption rate can be reduced by more than 50%, and the lifespan of the high-pressure feedwater heaters is significantly increased.

〔Effect of the invention〕

As detailed above, according to the warming method of the present invention, it is possible to prevent sudden temperature changes in the high-pressure feedwater heater during the startup process from boiler ignition to high-pressure feedwater heater in-service in a steam power plant. Accordingly, local thermal stress can be reduced. This naturally makes it possible to reduce the cost of the high-pressure feed water heater, and also to reduce the life consumption rate, which greatly contributes to the practical application of ultra-supercritical pressure plants.

[Brief explanation of the drawing]

Fig. 1 is a schematic system diagram of the conventional technology, Fig. 2 is a temperature state diagram of the high pressure feed water heater of the conventional technology, Fig. 3 is a chart showing the life consumption rate of the high pressure feed water heater of the conventional technology, and Figs. Fig. 10 is a 4% diagram of the water supply system in one embodiment of the present invention, Fig. 11 is a temperature state diagram of the high-pressure feed water heater in the embodiment of the present invention, and Fig. 12 is a chart showing the life consumption rate. . l... Condensate bone, 2... Deaerator, 3... Booster pump, 4... Boiler water pump, End... Water supply pipe, 6...
...Third high-pressure feed water heater, 7... Second high-pressure feed water heater, 8... First high-pressure feed water heater, 9... First bleed pipe,
10...Second air bleed pipe, 11...Third air bleed pipe, 12.
... Fourth bleed pipe, 13... Deaerator circulation pump, 14.
... Deaerator circulation piping, 15... Water pump bypass pipe, 16... Preboiler cleanup pipe, 17...
Boiler water tvb piping, 18...auxiliary steam header, 19
... In-house boiler, 20 ... Deaeration rice auxiliary steam pipe, 21
... Warming steam pipe, 22 ... Angularity control valve, 2
3... Temperature detector, 24... Warming heater,
25... Warming pipe, 26... Warming drain pipe, 27... High pressure feed water heater bypass pipe, tl.
... At the time of ventilation, "2... At the time of joining, t3... At the time of third high pressure feed water heater in service, t4... At the time of second high pressure feed water heater in service, t5... At the time of first high pressure water supply At the time of heater in-service, T6...Third high-pressure feedwater heater inlet water supply temperature, T7...Second high-pressure feedwater heater inlet water supply temperature, T8...First high-pressure feedwater heater inlet water supply temperature. Patent attorney Masami Akimoto 3 drawings) 'Wed 2FMlK odd L width (・C) Funeral 12 drawings

Claims (1)

[Claims] 1. In the startup process of a steam engine plant, a high-temperature fluid other than the extracted steam of the steam engine is introduced into the water supply system to preheat the feed water, and from the start of ventilation until the feed water heater is in service. A warming method for a high-pressure water heater, characterized by suppressing the temperature rise rate (per hour) of the high-pressure water heater. 2. In the water supply system of a steam engine plant, a pipe line for introducing high temperature fluid other than extracted steam from the steam engine into the water supply system, and a means for heat exchange between the introduced steam and the water supply are provided. A warming device for a high-pressure water heater, which is characterized by: 3. The high-temperature fluid is converted into high-temperature steam, and
Claim 1, characterized in that the above-mentioned preheating of the feed water by high-temperature steam is performed using a high-pressure feed water heater, and the high-temperature steam flow rate is controlled based on the feed water temperature at the outlet of the high-pressure feed water heater. Warming method for the high-pressure water heater described in Section 1. 4. The high-temperature fluid is converted into high-temperature steam, and the heat exchange means is a surface pressure feed water heater, and
Claim 2, further comprising a feed water temperature detector at the outlet of the high pressure feed water heater, and means for controlling the flow rate of high temperature steam based on the detection signal of the detector. A warming device for a high-pressure water heater described in . 5. The above water supply is used by extracting a part of the deaerator circulating water,
2. The method for warming a high-pressure feedwater heater according to claim 1, wherein the high-temperature fluid is high-temperature steam, and the feedwater is heated by a heat exchanger provided separately from the surface-pressure feedwater heater. 6. The means for performing the heat exchange extracts a part of the deaerator circulating water and heats it with high-temperature steam, and is constructed separately from the high-pressure feed water heater. A warming device for a high-pressure feed water heater according to claim 2. 7. The above water supply is used by extracting a part of the deaerator circulating water,
2. The method of warming a high-pressure feedwater heater according to claim 1, wherein the high-temperature fluid is high-temperature steam, and the warming is performed at a location closest to the discharge port of the deaerator circulation pump. 8. The water supply is characterized in that a part of the deaerator circulating water is extracted and heated with high-temperature steam, and is connected to a point immediately adjacent to the discharge port of the deaerator circulation pump. A warming device for a high-pressure feed water heater according to claim 2. 9. The above-mentioned preheating of the feed water is performed by extracting the feed water from the connection point between the booster pump discharge port and the boiler feed water pump suction port,
2. The method for warming a high-pressure feedwater heater according to claim 1, wherein the warming is performed using high-temperature steam, and the heating-side fluid that has been preheated is recovered in a condenser. 10. The means for performing the heat exchange includes connecting the inlet of the fluid to be heated to the discharge port of the booster pump, and
A patent claim characterized in that the outlet of the fluid to be heated is connected to the feed water inlet of a high-pressure feed water heater, and the outlet of the heated fluid of the heat exchange means is connected to a condenser. Warming device for a high-pressure water heater as described in Item 2 of (N SEITO) A warming method for a high-pressure feed water heater according to claim 1, characterized in that: 12. The means for exchanging heat of the flowing water connects the inlet on the side to be heated to water MMt). 3. The warming device for a high-pressure feed water heater according to claim 2, wherein the warming device is connected to a pump discharge port, and the outflow port on the side to be heated is connected to the inlet of the high-pressure feed water heater.