JPH0333888B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a power generation system that is particularly effective for small private power generation equipment.

An example of this type of power generation system is the one shown in FIG. In this system, a boiler 1 and a turbine 3 connected to a generator 2 are connected, and a pressure reducing valve 5 is provided in a bypass pipe 4 provided in parallel with the turbine 3. Under normal conditions, steam generated in the boiler 1 is sent to the turbine 3 to generate electricity. On the other hand, if the steam load decreases to 20 to 30% of the rated value, there will be no load as shown in FIG. 2, and if the steam load decreases further, motoring will occur, that is, power will be consumed. For this reason, when the load is low, the turbine 3 and generator 2 are stopped and process steam is supplied via the pressure reducing valve 5.

However, starting and stopping the turbine 3 and the generator 2 requires a lot of time and manual operations in order to avoid problems such as thermal stress deformation. Therefore, it is difficult to use this power generation system when the above-mentioned load fluctuation occurs every day. Therefore, in this case, steam is generally supplied by a low-pressure boiler and electricity is purchased from electricity, but this poses a problem in terms of energy conservation.

On the other hand, in the case of steam conditions where the pressure is low and the load difference between day and night is large as shown in FIG. 3, a system combining a low pressure boiler 6 and an accumulator 7 shown in FIG. 4 is known as a steam supply system. In this case, the accumulator is controlled independently using valves 8 and 9, and the boiler is controlled manually to keep the internal pressure of the accumulator within a certain range. However, since this system is manually operated, there is a problem in terms of labor saving.

The present invention was made in view of the above circumstances, and
It is an object of the present invention to provide a power generation system that can drive a turbine even when the load is low, thereby saving energy and labor.

That is, the present invention connects a boiler and a generator to a turbine via a pressure control valve, and a bypass pipe equipped with a steam ejector is interposed in parallel between the boiler and the pressure control valve, and A part of the process steam pipe connected to the steam outlet of the turbine is branched and connected to the steam inlet of an accumulator, and the steam outlet of the accumulator is connected to the steam ejector.

The present invention will be explained below with reference to the embodiment shown in FIG. In the illustrated power generation system, a boiler 11 and a turbine 12 are connected by a steam supply pipe 13, and a pressure control valve 14 is attached to the steam supply pipe 13. A bypass pipe 15 is provided between the boiler 11 and the pressure control valve 14 in parallel with the steam supply pipe 13, and a valve 16, a steam ejector 17, and a valve 18 are attached to this bypass pipe 15 in this order.

The turbine 12 is connected to a generator 19. A process steam pipe 20 is connected to the steam outlet of the turbine 12, and a valve 21 is attached to the process steam pipe 20. A branch pipe 22 branched from the process steam pipe is equipped with a valve 23 and connected to a steam inlet of an accumulator 24 . A steam outlet of the accumulator 24 is connected to the steam ejector 17 via a steam supply pipe 25 and a steam supply pipe 26
It is connected to the process steam pipe 20 via. A valve 27 is attached to this steam supply pipe 26. Further, the valve 18 of the bypass pipe 15 is connected to the process steam pipe 20.

This power generation system automatically controls the boiler 11 by detecting the internal pressure of the accumulator 24, and controls the boiler pressure at a constant level using the pressure control valve 14.

The steam generated in the boiler 11 drives the turbine 12 to generate electric power, and then passes through the process steam pipe 20.
pass through.

If the steam passing through the turbine is greater than the steam required for the process, it passes through the branch pipe 22 and is transferred to the accumulator 2.
4 is temporarily stored.

Conversely, if the amount is low, the steam stored in the accumulator 24 is pressurized through the steam ejector 17 using the steam passing through the bypass pipe 15, and is supplied to the process.

The pressure control valve 14 serves to ensure a minimum amount of steam passing through the turbine 12 and to prevent backflow so that the amount of power generated by the generator 19 does not exceed the amount required by the factory. In this case, a portion of the process steam is passed through the valve 18 to the process steam line 20 to make up for the shortage of process steam.

Note that the present invention is not limited to the above-mentioned embodiment, and it is possible to vary the outlet pressure of the turbine 12 within a range of variation according to a change in the internal pressure of the accumulator 24. This allows the plant to meet the steam and
Can respond flexibly to electricity.

As explained above, according to the present invention, by combining the accumulator and the steam ejector,
It is possible to cope with low loads and severe load fluctuations using existing equipment, and it is possible to save energy and labor, and it is particularly effective for small private power generation equipment.

[Brief explanation of drawings]

Figure 1 is an explanatory diagram of a conventional power generation system, Figure 2 is a characteristic diagram showing the relationship between generator end output and steam load in the same system, Figure 3 is an explanatory diagram showing an example of variation in process steam load, FIG. 4 is an explanatory diagram of a steam supply boiler and an accumulator system, and FIG. 5 is an explanatory diagram of a power generation system showing an embodiment of the present invention. DESCRIPTION OF SYMBOLS 11...Boiler, 12...Turbine, 13...Steam supply pipe, 14...Pressure control valve, 15...Bypass pipe, 1
6, 18, 21, 23, 27... Valve, 17... Steam ejector, 19... Generator, 20... Process steam pipe,
22... Branch pipe, 24... Accumulator, 25... Steam supply pipe, 26... Steam supply pipe.

Claims (1)

[Claims] 1. A boiler and a turbine connected to a generator are connected via a pressure control valve, and a bypass pipe equipped with a steam ejector is interposed in parallel between the boiler and the pressure control valve, and a steam outlet of the turbine is connected. A power generation system characterized in that a part of a process steam pipe connected to the is branched and connected to a steam inlet of an accumulator, and a steam outlet of the accumulator is connected to the steam ejector.