JPH10205706A - Pressurized fluidized bed boiler equipment - Google Patents

Abstract

(57) [Summary] [PROBLEMS] The ash adhering to the heat transfer tube in a gas cooler can be blown off by compressed air without separately providing a dedicated compressor and receiver, thereby reducing equipment costs. And a pressurized fluidized-bed boiler facility capable of preventing generation of drain as in the case of using steam. SOLUTION: A compressed air in the pressure vessel 7 is inserted and disposed in a high-pressure gas cooler 37 and a low-pressure gas cooler 39 by inserting a distal end of a pipe 44 having a base end connected to the pressure vessel 7 and provided with a valve 43 on the way. Can be injected into the high-pressure gas cooler 37 and the low-pressure gas cooler 39.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a pressurized fluidized-bed boiler facility.

[0002]

2. Description of the Related Art In recent years, pressurized fluidized-bed boiler equipment has been developed for effective use of energy.

Hereinafter, an example of a pressurized fluidized-bed boiler facility will be described with reference to FIG.

The pressurized fluidized-bed boiler equipment includes a fluidized-bed boiler main body 3 in which an evaporator 5, a superheater 1 and a reheater 2 are installed, and a pressure vessel 7 in which the fluidized-bed boiler main body 3 is installed. A predetermined amount of bed material 4 is charged in the fluidized-bed boiler main body 3.

[0005] The upstream end of the superheater 1 in the steam flow direction is connected to the boiler water supply system 6 via a line 19 via an evaporator 5, and the downstream end is connected to the steam of a high pressure turbine 11 of a steam turbine facility 10 via a line 20. An upstream end of the reheater 2 in the steam flow direction is connected to a steam outlet of the high-pressure turbine 11 of the steam turbine facility 10 via a pipe 21, and a downstream end is connected to a steam outlet of the steam turbine facility 10 via a pipe 22. Medium and low pressure turbine 1
The steam outlet of the medium-to-low pressure turbine 12 is connected to the boiler water supply system 6 via a pipe 23.

[0006] The boiler water supply system 6 includes a condenser 28 for cooling and condensing steam discharged from the medium / low pressure turbine 12,
A condensate pump 29 provided on the outlet side of the condenser 28, a low-pressure feedwater heater 30 for heating the boiler feedwater pressurized by the condensate pump 29, and a boiler feedwater from the low-pressure feedwater heater 30 A deaerator 31 for deaeration, a water supply pump 32 provided on the outlet side of the deaerator 31, and a high-pressure water heater 33 for heating boiler water pressurized by the water supply pump 32 are provided. Has the following configuration.

The pressure vessel 7 has a gas turbine 2
A compressor 14 that is driven by the compressor 6 and compresses the atmosphere 15 is connected via a compressed air supply line 16, and the fluidized-bed boiler main body 3 is provided with a cyclone 8 (two stages in the illustrated example) on the way. The gas inlet of the gas turbine 26 is connected to the gas inlet of the gas turbine 26 via the pipe 25, and the gas outlet of the gas turbine 26 is connected to the chimney 35 by the flue 34.
4 In the middle, the bypass line 36 of the high pressure feed water heater 33
A high-pressure gas cooler 37 for recovering the heat of the exhaust gas by boiler feedwater flowing through, a low-pressure gas cooler 39 for recovering the heat of the exhaust gas by boiler feedwater flowing through the bypass line 38 of the low-pressure feedwater heater 30, and an electric dust collector 40 are provided. .

In the pressurized fluidized-bed boiler equipment described above, compressed air obtained by compressing the atmosphere 15 by the compressor 14 is supplied to the pressure vessel 7 from the compressed air supply line 16, and the bed material 4 flows into the fluidized-bed boiler main body 3. After forming the layer 17, the fuel 18 such as coal is supplied to the fluidized bed 17 to form the fluidized bed 1.
Burn in 7.

When the fuel 18 burns, its thermal energy is transmitted to the bed material 4 in a flowing state, and the bed material 4 comes into contact with the evaporator 5, the superheater 1 and the reheater 2, whereby the heat energy is transferred. Energy is transmitted to the evaporator 5, the superheater 1, and the reheater 2.

[0010] The boiler feedwater supplied from the boiler feedwater system 6 to the evaporator 5 is vaporized by the heat energy, and the steam is turned into superheated steam by the superheater 1, and the superheated steam flows into the high-pressure turbine 11 of the steam turbine facility 10. Thus, the high-pressure turbine 11 is driven.

The steam after driving the high-pressure turbine 11 is:
The steam which flows into the reheater 2 and is reheated by the reheater 2 flows into the medium / low pressure turbine 12 and
2 and the steam after driving the medium-to-low pressure turbine 12 are returned to the boiler feed water by the condenser 28 of the boiler feed system 6, and passed through the condensate pump 29 to the low pressure feed water heater 30.
After the heat of the exhaust gas, which will be described later, is recovered in the low-pressure gas cooler 39 by a part of the boiler feedwater branched to the bypass line 38, the boiler feedwater is deaerated by the deaerator 31. The boiler feed water degassed by the air blower 31 is pressurized by the feed water pump 32 and then heated in the high pressure feed water heater 33 and is later described in the high pressure gas cooler 37 by a part of the boiler feed water branched to the bypass line 36. The heat of the flue gas is recovered,
It is supplied to the evaporator 5 again.

In this way, the steam turbine facility 10 is driven by the steam, and power is generated by the steam turbine generator 24 connected to the steam turbine facility 10.

On the other hand, the flue gas of the fuel 18 burned in the fluidized-bed boiler main body 3 is separated from most of the ash by the cyclone 8 and then passed through the pipe 25 to the gas turbine 2.
6 and is generated by a gas turbine generator 27 connected to the gas turbine 26, and at the same time,
The compressor 14 is driven by the gas turbine 26.

The exhaust gas after driving the gas turbine 26 flows through a flue 34, heat is recovered by a boiler feedwater flowing through a bypass line 36 of a high-pressure feedwater heater 33 in a high-pressure gas cooler 37, and is further reduced in a low-pressure gas cooler 39. The heat is recovered by the boiler feedwater flowing through the bypass line 38 of the feedwater heater 30, and the ash that cannot be separated by the cyclone 8 is further collected in the electric dust collector 40, and then discharged to the atmosphere from the chimney 35.

In the case of the pressurized fluidized-bed boiler equipment as described above, most of the ash is separated and removed in the cyclone 8, but some of the ash is not separated and removed in the cyclone 8, but together with the exhaust gas. Flows into the flue 34, the ash adheres and accumulates on the heat transfer tubes in the high-pressure gas cooler 37 and the low-pressure gas cooler 39, and the heat exchange rate decreases, thereby reducing the overall plant efficiency or increasing the exhaust gas temperature. There is a possibility that the design temperature of various devices may be exceeded.

For this reason, conventionally, as shown in FIG. 2, a dedicated compressor 41 and a receiver 42 are provided, and the high-pressure air pressurized by the compressor 41 is temporarily stored in the receiver 42, and it The high pressure air in the receiver 42 is supplied to the pipe 4
4, the high-pressure gas cooler 37 and the low-pressure gas cooler 3
9 or a part of the auxiliary steam in the system of the steam turbine equipment 10 is injected into the high-pressure gas cooler 37 or the low-pressure gas cooler 39 via a pipe (not shown), and the high-pressure gas cooler 37 or the low-pressure gas cooler 39 The ash adhering to and accumulating on the heat transfer tubes inside is blown off periodically.

[0017]

However, as described above, the high-pressure air pressurized by the compressor 41 is temporarily stored in the receiver 42, and the high-pressure air in the receiver 42 is opened and closed by operating the valve 43 as necessary. Piping 44
Through the high-pressure gas cooler 37 and the low-pressure gas cooler 39
Injecting into the inside requires the dedicated compressor 41 and the receiver 42 to be separately provided, which has a disadvantage that the equipment cost increases.

Further, if a part of the auxiliary steam in the system of the steam turbine facility 10 is injected into the high-pressure gas cooler 37 or the low-pressure gas cooler 39 via a pipe (not shown), drain is easily generated, and ash is drained. This may make it difficult to blow and may cause clogging of the high-pressure gas cooler 37 and the low-pressure gas cooler 39.

According to the present invention, in view of such circumstances, the ash deposited on the heat transfer tube in the gas cooler can be blown off by the compressed air without separately providing a dedicated compressor and receiver, thereby reducing equipment costs. It is an object of the present invention to provide a pressurized fluidized-bed boiler facility capable of preventing drainage from occurring as in the case of using steam.

[0020]

SUMMARY OF THE INVENTION The present invention provides a fluidized bed boiler main body in a pressure vessel, and a gas outlet side of a gas turbine driven by exhaust gas discharged from the fluidized bed boiler main body through a cyclone. In a pressurized fluidized-bed boiler facility in which a gas cooler that recovers heat of exhaust gas by boiler water supply of a boiler water supply system is provided in the middle of a flue connected to a boiler water supply system, compressed air in a pressure vessel can be injected into the gas cooler. The present invention relates to a pressurized fluidized-bed boiler facility characterized by the following.

According to the above means, the following effects can be obtained.

When the compressed air in the pressure vessel is injected into the gas cooler as required, the ash attached to the heat transfer tube in the gas cooler is blown off.

As a result, it is not necessary to separately provide a dedicated compressor and a receiver as in the prior art, and since steam is not used, drain is less likely to occur, and ash does not stick to the ash, and the gas cooler is clogged. There is no need to worry.

[0024]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 shows an example of an embodiment of the present invention. In FIG. 1, the parts denoted by the same reference numerals as those in FIG. This embodiment is the same as the one shown in FIG. 1 except that, as shown in FIG. 1, the distal end of a pipe 44 having a base end connected to the pressure vessel 7 and a valve 43 provided on the way is connected to the high-pressure gas cooler 3.
7 and inserted into the low pressure gas cooler 39,
The configuration is such that the compressed air in the pressure vessel 7 can be injected into the high-pressure gas cooler 37 and the low-pressure gas cooler 39.

Next, the operation of the illustrated example will be described.

Generally, the compressor 14 of the gas turbine 26 is provided in the pressure vessel 7 in the pressurized fluidized-bed boiler facility.
The operating pressure in the pressure vessel 7 is usually several [kgf / cm ² ] to 15
[Kgf / cm ² ], and the pressure vessel 7 is similar to a huge receiver.
When the valve 3 is opened, the compressed air in the pressure vessel 7 is injected into the high-pressure gas cooler 37 and the low-pressure gas cooler 39, and the ash deposited on the heat transfer tubes in the high-pressure gas cooler 37 and the low-pressure gas cooler 39 is blown away.

As a result, it is not necessary to separately provide a dedicated compressor 41 and a receiver 42 as in the prior art.
Since steam is not used, drainage is less likely to occur, drainage does not adhere to the ash, and there is no fear of causing clogging of the high-pressure gas cooler 37 or the low-pressure gas cooler 39.

As described above, the high-pressure gas cooler 37 can be used without providing the dedicated compressor 41 and the receiver 42 individually.
Deposited on the heat transfer tube in the gas cooler 39 or the low-pressure gas cooler 39 can be blown off by compressed air, thereby reducing equipment costs and preventing generation of drain as in the case of using steam. .

The pressurized fluidized-bed boiler equipment of the present invention is not limited to the above-described example, but may be modified in various ways without departing from the gist of the present invention.

[0031]

As described above, according to the pressurized fluidized bed boiler equipment of the present invention, the ash adhering to the heat transfer tube in the gas cooler can be removed by the compressed air without separately providing a dedicated compressor or receiver. Can be blown away,
It is possible to achieve an excellent effect that it is possible to reduce the equipment cost and to prevent the generation of drain as in the case of using steam.

[Brief description of the drawings]

FIG. 1 is an overall schematic configuration diagram of an example of an embodiment of the present invention.

FIG. 2 is an overall schematic configuration diagram of a conventional example.

[Explanation of symbols]

 3 Fluidized bed boiler body 6 Boiler water supply system 7 Pressure vessel 8 Cyclone 26 Gas turbine 37 High pressure gas cooler (gas cooler) 39 Low pressure gas cooler (gas cooler) 43 Valve 44 Piping

Claims (1)

[Claims] 1. A fluidized-bed boiler main body is disposed in a pressure vessel, and is provided in a flue connected to a gas outlet side of a gas turbine driven by exhaust gas discharged from the fluidized-bed boiler main body through a cyclone. In a pressurized fluidized-bed boiler facility provided with a gas cooler that recovers heat of exhaust gas by boiler water supply of a boiler water supply system, pressurization is configured to be able to inject compressed air in a pressure vessel into the gas cooler. Fluidized bed boiler equipment.