JPH0688502A - Power generating plant - Google Patents

Abstract

PURPOSE:To improve efficiency at the time of a low load during a night, etc., when power demand is not so much. CONSTITUTION:In a power generating plant provided with a steam generating device 1, a steam heating device 2 for heating steam from the steam generating device 1, steam turbines 4A-4B which are directly supplied with steam heated by the steam heating device 2 at the time of a high load and steam supplied from the steam generating device 1 at the time of a low load, and power generator 5 connected to a steam turbine, the steam turbine is divided into at least a high pressure part 4A and a low pressure part 4B, and they are connected to each other through a clutch 21. The clutch 21 is engaged at the time of high load, and the high pressure part 4A and the low pressure part 4B of the steam turbine are connected to each other so as to form a total shaft system. On the other hand, the clutch 21 is disengaged at the time of the low load, and the high pressure part 4A and the low load 4B of the steam turbine are separated from each other so as to lead directly steam supplied from the steam generating device 1 only to the low pressure part 4B of the steam turbine.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a power plant,
More specifically, a steam generator, a steam heating device for heating steam from the steam generator, steam heated by the steam heating device at high load, and steam from the steam generator at low load. The present invention relates to a power plant that includes a steam turbine that is directly supplied and a generator that is connected to the steam turbine.

[0002]

2. Description of the Related Art As conventional examples of such a power plant, there are two examples shown in FIGS. 4 and 5, for example. First, the conventional example shown in FIG. 4 will be described.

In FIG. 4, reference numeral 1 is a steam generator, 2 is a steam heating apparatus (which is composed of an exhaust gas boiler in this example), and 3 is a steam turbine power generator comprising a steam turbine 4 and a generator 5. Although not shown, the steam generator 1 generates steam by using heat generated in a refuse incinerator as a heat source. Then, at the time of high load, by closing the valve 6 and opening the valves 7 and 8, the steam generated in the steam generator 1 is sent to the steam heating device 2,
Here, the steam temperature is raised by being heated by the exhaust gas from the gas turbine power generator 9 (comprising the compressor 10, the gas turbine combustor 11, the gas turbine 12, and the power generator 13), and then the steam of the steam turbine power generator 3 is increased. After being sent to the turbine 4 for work, the water is condensed in the condenser 14,
It becomes water and is supplied to the steam generator 1 by the pump 15. The generator 5 is driven by the steam turbine 4.

On the other hand, at low load (partial load) such as at night when the power demand is low, the gas turbine power generator 9 is stopped. Therefore, by opening the valve 6 and closing the valves 7 and 8, the steam generator 1 can be operated. The generated steam is steam heating device 2
It is designed to be directly supplied to the steam turbine 4 of the steam turbine power generator 3 without going through.

Next, the conventional example shown in FIG. 5 will be described. This conventional example is a valve 6 in the conventional example shown in FIG.
7, 8 are abolished, the direct connection between the steam generator 1 and the steam turbine 4 is stopped, and the high temperature gas generator 16 is connected to the steam heating device 2 side by side with the gas turbine power generator 9. is there.

Even in the conventional example shown in FIG. 5, as in the conventional example shown in FIG. 4, when the load is high, the steam from the steam generator 1 is fed by the steam heating device 2 to the gas turbine generator 9. After being heated by the exhaust gas from the steam turbine, it is introduced into the steam turbine 4 of the steam turbine power generator 3.

Further, when the load is low, such as at night, when the power demand is low, the gas turbine power generator 9 is stopped as in the conventional example shown in FIG. 4, but the steam supplied from the steam generator 1 to the steam turbine 4 is stopped. In order to maintain the temperature of the engine at the same level as under high load, the high temperature gas generator 16 is supplied with fuel and a forced draft fan 17
The air from the steam generator 1 is introduced into the steam heating device 2 and the high temperature gas generated thereby is burned.
I am trying to heat the steam from.

Since the other structure is the same as that shown in FIG. 4, the same parts are designated by the same reference numerals and the duplicated description will be omitted.

[0009]

By the way, the conventional power plant described above has the following problems.

That is, in the conventional example shown in FIG. 4, the gas turbine power generator 9 is stopped and the steam of the steam generator 1 is not passed through the steam heating device 2 when the load is low such as at night when the power demand is low. Since the steam is directly supplied to the steam turbine 4 of the steam turbine power generator 3, the low temperature steam from the steam generator 1 is directly introduced into the steam turbine 4 without being heated. There was a problem that the steam temperature at the inlet dropped significantly, leading to a drop in efficiency at low loads.

Further, in the conventional example shown in FIG. 5, when the load is low, the high temperature gas generated by the high temperature gas generator 16 is introduced into the steam heating device 2 instead of the exhaust gas from the gas turbine power generator 9. Since the steam from the steam generator 1 is heated by the above, there is no problem of the temperature drop of the steam introduced into the steam turbine 4, but on the other hand, in order to obtain the high temperature gas, the fuel for reheating is added. Also, there is a problem that it is uneconomical because a facility for burning this fuel is required, resulting in high cost.

The present invention has been made in order to solve the problems of the prior art as described above, and does not specially heat the steam introduced into the steam turbine, and the efficiency at the time of low load such as night when the power demand is small. It aims at providing the power generation plant which can improve.

[0013]

In order to solve the above problems, the present invention provides a steam generating device, a steam heating device for heating steam from the steam generating device, and a steam heating device at the time of high load. In a power plant including a steam turbine to which the steam from the steam generator is directly supplied when the heated steam is also under a low load, and a generator connected to the steam turbine, the steam turbine includes at least a high pressure part and a low pressure part. It is divided into parts and connected between them via a clutch.

[0014]

According to the above means, when the load is high, the clutch is engaged and the high pressure part and the low pressure part of the steam turbine are connected to form a full shaft system, but the clutch is disengaged when the load is low such as at night when power demand is low. By separating the high pressure part and the low pressure part of the steam turbine and directly introducing the steam from the steam generator only to the low pressure part of the steam turbine, the efficiency at low load can be improved.

[0015]

Embodiments of the present invention will now be described in detail with reference to the drawings.

FIG. 1 shows an embodiment of a power plant according to the present invention. The same parts as those shown in FIG. 4 are designated by the same reference numerals, and duplicate explanations are omitted. According to the present invention, at least two or more steam turbines 4 of the steam turbine power generator 3 shown in FIG. 4 are divided into a high pressure portion 4A and a low pressure portion 4B in this embodiment, and these are connected via a clutch 21. is doing.

When the load is high, the clutch 21 is inserted to connect the high pressure portion 4A and the low pressure portion 4B of the steam turbine 4 to form a full shaft system, and the valve 22 is opened and the valve 23 is closed. Therefore, the steam from the steam generator 1 is heated by the steam heating device 2 by the exhaust gas from the gas turbine power generator 9, and then introduced into the high pressure part 4A of the steam turbine 4, and then passes through the check valve 24 to the low pressure part. 4B is introduced.

On the other hand, when the load is low such as at night when the power demand is low, the gas turbine generator 9 is stopped and the steam cannot be heated by the exhaust gas in the steam heating device 2, so the clutch 21 is disengaged and the steam turbine 4 is closed. High voltage part 4
A and the low pressure part 4B are separated, and the valve 22 is closed and the valve 23 is opened, so that the steam from the steam generator 1 is directly introduced only to the low pressure part 4B of the steam turbine 4, and when the load is low. Try to improve the efficiency of.

The present invention is by no means limited to the embodiment shown in FIG. 1, and it goes without saying that various modifications can be made. For example, as shown in FIG. 2, the position of the clutch 21 shown in FIG. 1 may be between the generator 5 to which the high pressure portion 4A of the steam turbine is directly connected and the low pressure portion 4B of the steam turbine. Further, as shown in FIG. 3, at the time of high load, part of the exhaust gas from the high pressure portion 4A of the steam turbine can be taken out by the pipe line 25 and used as a heat source. Further, although not shown, the heat source of the steam generator 1 is not limited to the heat generated in the refuse incinerator, and other suitable heat source can be used. Similarly, the heating medium in the steam heating device 2 is not limited to the exhaust gas of the gas turbine 12, and other suitable heating medium can be used.

[0020]

As described above, according to the present invention, the steam generator, the steam heating device for heating the steam from the steam generator, and the steam heated by the steam heating device at the time of high load are provided. Further, in a power plant including a steam turbine to which steam from the steam generator is directly supplied when the load is low and a generator connected to the steam turbine, the steam turbine is divided into at least a high pressure portion and a low pressure portion. By connecting them via a clutch, the clutch is put in at high load to connect the high pressure part and the low pressure part of the steam turbine to form a full shaft system, but at low load such as at night when power demand is low. Sometimes the clutch is disengaged to separate the high pressure and low pressure parts of the steam turbine, and the steam from the steam generator is introduced directly only into the low pressure part of the steam turbine to reduce the load. Effect is achieved that it is possible to improve the rate.

Further, in this case, since the steam introduced from the steam generator into the steam turbine is not heated by the special high temperature gas, the fuel for additional heating and the equipment for burning this fuel are not required. Of course.

[Brief description of drawings]

FIG. 1 is a system diagram showing an example of a power plant according to the present invention.

FIG. 2 is a system diagram of a main part showing another example of the power plant according to the present invention.

FIG. 3 is a system diagram of a main part showing still another example of the power plant according to the present invention.

FIG. 4 is a system diagram showing an example of a conventional power generation plant.

FIG. 5 is a system diagram showing another example of a conventional power generation plant.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Steam generator 2 Steam heating device 4A High pressure part of steam turbine 4B Low pressure part of steam turbine 5 Generator 12 Gas turbine 21 Clutch

Claims (1)

[Claims] 1. A steam generator, a steam heater for heating steam from the steam generator, steam heated by the steam heater under high load, and steam from the steam generator under low load. A steam turbine supplied directly,
A power plant including a power generator connected to the steam turbine, wherein the steam turbine is divided into at least a high-pressure portion and a low-pressure portion, and these are connected via a clutch.