JPH0688505A - Power generating plant - Google Patents

Abstract

PURPOSE:To utilize energy effectively so as to heat the exhaust gas in a garbage incinerator up to a temperature necessary for denitration. CONSTITUTION:In a power generating plant provided with in parallel a garbage incinerator exhaust gas line (A) for discharging exhaust gas generated in a garbage incinerator 1 toward the atmosphere through at least an exhaust heat recovery boiler 2, an exhaust gas purifying device 5, an exhaust gas reheating device 6A and an exhaust gas denitration device 7 in order, and the gas turbine exhaust gas line (B) of a gas turbine power generating device, at least a part of heat in the exhaust gas discharged from a gas turbine 11 is used as heat source of the exhaust gas reheating device 6A, so as to heat the garbage incinerator exhaust gas.

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 waste gas incinerator exhaust gas line that sequentially discharges exhaust gas generated in the waste incinerator into the atmosphere through at least an exhaust heat recovery boiler, an exhaust gas purification device, an exhaust gas reheating device, and an exhaust gas denitration device, and a gas turbine power generation The present invention relates to a power plant having both a gas turbine exhaust gas line of an apparatus.

[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, A is a waste incinerator exhaust gas line, and B is a gas turbine exhaust gas line. Then, in the waste incinerator exhaust gas line A, the exhaust gas generated in the waste incinerator 1 sequentially flows through the exhaust heat recovery boiler 2, the air preheater 3 and the desuperheater 4 to be cooled to 150 ° C. or lower, and then the exhaust gas. The gas is introduced into the purifying device 5 to remove hydrogen chloride, sulfur oxides, dust, dioxin, mercury gas and the like contained in the exhaust gas. The waste gas incinerator exhaust gas thus purified is then fed to the indirect exhaust gas reheating device 6
It is guided to A, heated by a part of the steam generated in the above-mentioned exhaust heat recovery boiler 2, and heated to about 200 ° C. or higher,
After that, NO _x in the exhaust gas is removed by the exhaust gas denitration device 7 and discharged from the chimney 8 into the atmosphere. On the other hand, in the gas turbine exhaust gas line B, the exhaust gas of the gas turbine 11 of the gas turbine power generator passes through the exhaust heat recovery boiler 12 and is discharged into the atmosphere from the chimney 13.

Next, the conventional example shown in FIG. 5 will be described. In this conventional example, the indirect type exhaust gas reheating device 6A in the conventional example shown in FIG. 4 is replaced with a direct type exhaust gas reheating device 6B, and a part of the high temperature air obtained by the air preheater 3 ( Alternatively, it may be a high-temperature gas) and is mixed with the exhaust gas of the refuse incinerator to raise the exhaust gas temperature to about 200 ° C or higher. Since other configurations are the same as those shown in FIG. 4, the same parts are designated by the same reference numerals, and the duplicated description will be omitted.

In the power plant shown in FIGS. 4 and 5, the temperature of the waste incinerator exhaust gas introduced into the exhaust gas purifying device 5 is set to 150 ° C. or lower because the removal rate of dioxin and mercury in the exhaust gas purifying device is high. This is because it depends on the temperature and becomes larger as the temperature becomes lower, so that operation at 150 ° C. or lower is required. The waste incinerator exhaust gas is heated to about 200 ° C or higher by the exhaust gas reheating devices 6A and 6B because the optimum operating temperature of the exhaust gas denitration device 7 is 200 to 350 ° C.

[0006]

In the prior art described above, however, there was a problem from the viewpoint of effective utilization of energy to heat the waste incinerator exhaust gas to the temperature required for denitration. That is, in the conventional example shown in FIG. 4, part of the high-temperature steam obtained in the exhaust heat recovery boiler 2 of the waste incinerator exhaust gas line A, and in the conventional example shown in FIG. Part of the high temperature air obtained by the air preheater 3 is used as a heat source for heating the exhaust gas in the exhaust gas reheating devices 6A and 6B, but the steam is used as steam for driving the steam turbine and the air is This is because it is useful energy used as combustion air.
On the other hand, although the exhaust gas from the gas turbine 11 is recovered by the exhaust heat recovery boiler 12, the remaining heat is not used at all and is discarded from the chimney 13.

The present invention has been made in order to solve the problems of the prior art as described above, and it aims at effective utilization of energy to heat the waste gas incinerator exhaust gas to a temperature required for denitration. The purpose is to provide a plant.

[0008]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention relates to at least exhaust gas recovery boiler, exhaust gas purifying device, exhaust gas reheating device and exhaust gas denitration device for exhaust gas generated in a refuse incinerator. In a power plant having both a waste incinerator exhaust gas line for exhausting to the atmosphere via a gas turbine exhaust gas line of a gas turbine power generator, at least a part of the heat of the exhaust gas discharged from the gas turbine of the gas turbine power generator is Is used as the heat source of the exhaust gas reheating device.

[0009]

According to the above means, the heat of the gas turbine exhaust gas can be used to heat the waste incinerator exhaust gas to the temperature required for denitration, and the gas turbine exhaust gas can be effectively used and exhausted. It is not necessary to use the important steam obtained from the heat recovery boiler to heat the exhaust gas from the refuse incinerator.

[0010]

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

FIG. 1 shows a first embodiment of the present invention. The same parts as those shown in FIG. 4 are designated by the same reference numerals, and the duplicated description will be omitted. In the present embodiment, the gas turbine exhaust gas discharged from the gas turbine 11 and passed through the exhaust heat recovery boiler 12 is connected to the indirect exhaust gas reheating device 6A by the pipe line 21.
Through which the waste incinerator exhaust gas is heated to a temperature (about 200 ° C. or higher) necessary for denitration. The supply amount of this gas turbine exhaust gas to the indirect exhaust gas reheating device 6A can be adjusted by the valve 22.

Next, FIG. 2 shows a second embodiment of the present invention.
The same parts as those shown in FIG. 4 are designated by the same reference numerals, and the duplicated description will be omitted. In this embodiment, the gas turbine exhaust gas discharged from the gas turbine 11 and passed through the exhaust heat recovery boiler 12 is guided to a heat exchanger 31 to heat a heat medium such as air, and the heated heat medium is pumped by a pump 32. The waste gas incinerator exhaust gas is heated to a temperature (about 200 ° C. or higher) necessary for denitration by passing the inside of the indirect exhaust gas reheating device 6A through the path 33.

Finally, FIG. 3 shows a third embodiment of the present invention, in which the same parts as those shown in FIG. 5 are designated by the same reference numerals, and a duplicate description will be omitted. In this example, the gas turbine exhaust gas discharged from the gas turbine 11 and passed through the exhaust heat recovery boiler 12 is directly introduced into the exhaust gas reheating device 6B through the pipe line 41 as it is, and is mixed with the waste incinerator exhaust gas. The temperature of the exhaust gas from the refuse incinerator is raised to the temperature required for denitration (about 200 ° C. or higher).

[0014]

As described above, according to the present invention, the exhaust gas generated in the refuse incinerator is sequentially introduced into the atmosphere through at least the exhaust heat recovery boiler, the exhaust gas purifying device, the exhaust gas reheating device and the exhaust gas denitration device. In a power plant having both a waste incinerator exhaust gas line to be discharged and a gas turbine exhaust gas line of a gas turbine power generator, at least a part of heat of exhaust gas discharged from the gas turbine of the gas turbine power generator is reheated. By using it as the heat source of the equipment, the heat of the gas turbine exhaust gas can be used to heat the waste incinerator exhaust gas to the temperature required for denitration, so that the gas turbine exhaust gas can be effectively used and exhausted. The effect is that the valuable steam obtained in the heat recovery boiler does not have to be used for heating the exhaust gas of the refuse incinerator.

[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 showing another example of a power plant according to the present invention.

FIG. 3 is a system diagram 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]

 A waste incinerator exhaust gas line B gas turbine exhaust gas line 1 waste incinerator 2 exhaust heat recovery boiler 3 air preheater 4 temperature reducer 5 exhaust gas purification device 6A indirect exhaust gas reheating device 6B direct exhaust gas reheating device 7 exhaust gas denitration device 8 Chimney 11 Gas turbine 12 Exhaust heat recovery boiler 13 Chimney 31 Heat exchanger

Claims (1)

[Claims] 1. A waste incinerator exhaust gas line for sequentially discharging exhaust gas generated in a waste incinerator to the atmosphere through at least an exhaust heat recovery boiler, an exhaust gas purifying device, an exhaust gas reheating device and an exhaust gas denitration device, and a gas turbine power generation. In a power plant that also has a gas turbine exhaust gas line of the device,
A power plant, wherein heat of at least part of exhaust gas discharged from a gas turbine of the gas turbine power generator is used as a heat source of the exhaust gas reheating device.