JPS61138833A - Generating set using solid fuel - Google Patents

Abstract

PURPOSE:To aim at an efficiency improvement, by heating discharge compressed air with waste gas out of a combustion furnace of a pyrolytic gasifier, while leading it into a duct burner together with pressure combustible gas out of a gasifier furnace for a complete combustion. CONSTITUTION:Waste gas out of a combustion furnace 36 of a pyrolytic gasifier 35 gasifying wood solid fuel is led into an air heater 41 and heats discharge compressed air as specified. And, combustible gas out of a gasifier furnace 38 is pressurized with a gas compressor 43. The heated compressed gas and the pressurized combustible gas both are led into a duct burner 44 and burned and fed to a gas turbine 32. With this constitution, since such combustion gas as being sufficiently raised in temperature is secured, efficiency is well improvable.

Description

[Detailed Description of the Invention] [Industrial Application Field] This invention relates to a power generation device that uses solid fuel, and particularly to a power generation device that uses wood chips obtained by crushing wood chips or waste materials as solid fuel. It is.

[Conventional technology]

Generally, when wood is used, a large amount of wood chips and waste materials are generated, which can be a source of pollution, and it is important to process them and use them effectively from the standpoint of resource conservation. As a link to this demand, a method has been proposed in which these wood chips and waste materials are used as a solid fuel as a driving energy source for a power generation device.

As a conventional power generation device using wood materials as solid fuel, a steam turbine-driven device using a so-called Dutch oven type boiler is known. As shown in Fig. 2, this power generation device supplies solid wood fuel such as wood chips to a hopper 2 directly to a goo-two open type boiler 1 through a feeder 3, etc., and generates electricity using the steam generated. The steam turbine 4 directly connected to the a5 is driven to obtain electric power, the discharged steam is condensed by the condenser 6, and the water supply pump 7 is used to supply water to the wheeler 1 again.

Separately, as an improved power generation device of the same type, as shown in FIG. gas turbine 10,
and a power generation section 8 to which a generator 11 is directly connected, and a burner 14 to which wood solid fuel such as wood chips is supplied from a fuel supply system 15. Combustion furnace 1 each having a water spray nozzle 16
3. A combustion section 12 consisting of an air heater 17 integrally formed with this combustion furnace 13, a steam turbine 20 directly connected to a waste heat recovery boiler 189 and a generator 21, and a condenser 22
．． A waste heat recovery section 1 consisting of a circulation system of a water supply pump 23 and a water supply pump 23.
8 is known.

In the case of the conventional device shown in FIG. 3, fuel and primary air are supplied to a burner 14 in a combustion furnace 13, and are combusted under water spray from a nozzle 16 to form an air heater 17. On the other hand, the air pressurized by the pneumatic machine 9 is heated by the air heater 17, and the high temperature and high pressure air thus obtained is used as a heat source for the gas turbine 1.
0 is driven to obtain electric power, a part of this driving force is used to drive the air compressor Ii 8, and the exhaust air from the gas turbine IO is used as primary air to the eight 14. Furthermore, the residual energy of the combustion gas discharged from the combustion furnace 13 via the air heater 17 is recovered by the waste heat recovery boiler 18, and the steam obtained from the boiler 19 is used to power the steam turbine 20 directly connected to the generator 21. After being driven to obtain electric power, the discharged steam is condensed in a condenser 22, and water is again supplied to the boiler 19 by a water supply pump 23.

[Problem that the invention seeks to solve]

Although the former conventional example shown in FIG. 2 is generally well-established as an established technology, it has the disadvantage of extremely poor thermal efficiency due to its structure. The latter conventional example shown in Fig. 3 is a device that has recently been attracting attention as an alternative to the former device, but when comparing the complexity of the equipment and equipment, the latter device also has the following points. For some reason, this type of wood solid fuel has the disadvantage that the inherent available energy (usually called exergy) cannot always be effectively utilized.

That is, in this latter device, as mentioned above,
Wood chips, etc. that have been crushed to a specified particle size and size,
- It is burned in the combustion furnace 13 by the burner 14 together with secondary air, and the resulting thermal energy is used as a heat source for the air heater 17. At this time, there are restrictions on heat resistance in this type of combustion furnace 13 (usually, its heat resistance The temperature limit is about 900°C), and similarly, the thermal strength constraints of the heat exchanger tubes in the air heater 17 (generally the limit is about 800°C). Therefore, although the adiabatic combustion temperature of wood chips used as fuel is originally around 1,500 to 1,700°C, by using water spray from the nozzle 16 in conjunction with this, the combustion temperature can be lowered to the above-mentioned level. The temperature is decreased according to the constraints, and the temperature decrease during this time (in this case, 1500-1700-800 = 700-90
0℃.

In other words, only about half of the combustion temperature that can be obtained in the first place is considered to be ineffective energy.

Therefore, in this ~, the temperature of the air discharged from the air heater 17 is also necessarily suppressed to, for example, about 8QO ℃,
The efficiency of the next stage gas turbine cycle achieved by introducing this (depending on the turbine inlet temperature of the introduced gas) is extremely reduced, and the performance of the gas turbine 10 cannot be effectively exhibited. It was something that didn't exist. By the way, in a gas turbine that uses normal heavy oil or natural gas as fuel,
Turbine inlet temperature is at least 1000-1150°C
It is possible to some extent. That is, in this way, the third
The conventional device has the disadvantage of not being able to maximize the energy efficiency of the solid wood fuel due to constraints on the strength of the materials that make up the device. Various problems were also overcome regarding the treatment of products such as tar.

[Means for solving problems]

This invention attempts to improve these conventional problems, and includes a power generation section that directly connects an air compressor, a gas turbine, and a generator, a duct eight placed in the path to the gas turbine, and a combustion furnace. , a two-unit fluidized bed type pyrolysis gasifier equipped with a gasification furnace to gasify wood solid fuel, and an air heating system that indirectly heats the air discharged from an air compressor using combustion waste gas from the combustion furnace. A power generation device is composed of a gas compressor and a gas compressor that pressurizes the combustible gas produced in the gasifier.

[For production]

Therefore, in this invention, wood solid fuel is turned into combustible gas by a two-unit fluidized bed type pyrolysis gasifier, and the air discharged from the air compressor is indirectly heated by the combustion waste gas from the combustion furnace, and the air is gasified. By pressurizing the combustible gas generated in the furnace and burning the pressurized combustible gas and indirectly heated high-pressure air with a duct burner, the temperature of the high-pressure air at the gas turbine inlet can be sufficiently raised. It can be used to drive gas turbines.

[Actual travel example]

Hereinafter, one embodiment of a power generation device using solid fuel according to the present invention will be described in detail with reference to FIG.

FIG. 1 is a block diagram showing an outline of the apparatus of this embodiment. That is, in this example device, air compression @32. Gas turbine 33. and a combustion furnace 36 that receives a predetermined amount of sand as a heat medium from a medium supply system 37. The fuel supply system 39 also includes a gasifier 38 that supplies wood solid fuel such as wood chips and gasifies it. and a dual fluidized bed type pyrolysis gasifier 35 comprising a fan 40 that supplies air as a fluidization medium to the combustion furnace 3B, and an air heater 41 using combustion waste gas from the combustion furnace 3B. A gas scrubber 42 for scrubbing the produced gas from the gasifier 38. and a gas compressor 43;
A duct burner 44 for burning this pressurized gas and a waste heat recovery boiler 45 are provided.

In the case of the above-mentioned embodiment configuration, in the two-base fluidized bed type pyrolysis gasifier 35, due to the combustion action in the combustion furnace 36,
Combustion waste gas is discharged from the combustion furnace 36, and combustible gas is generated from the wood solid fuel such as wood chips introduced from the gasification furnace 38.

Therefore, once the combustion waste gas from the combustion furnace 36 is
The air is fed to the air heater 41 and, on the other hand, the air compressor 33
The pressurized discharge air is heated through the air heater 4 and then supplied to the duct burner 44, and the generated gas from the gasifier 38 is once passed through the gas washer 42.
After being sufficiently cleaned with the supplied washing water, the air is pressurized to a predetermined pressure by a gas compressor 43 and supplied to the duct burner 44, where the pressurized and heated air It is combusted together with the gas, producing high-temperature, high-pressure combustion gas.

Next, the gas turbine 10 is driven by the high-temperature, high-pressure combustion gas obtained as described above, electric power is obtained from the generator 11 directly connected to the gas turbine 10, and the air compressor 33 is also driven by a portion of the driving force. The pressurized air described above is obtained. and the combustion waste gas that has passed through the air heater 41;
The exhaust gases discharged from the gas turbine IO are both subjected to waste heat recovery by the waste heat recovery boiler 45, and are appropriately treated to meet environmental emission standards before being released into the outside air.

That is, in the configuration of the embodiment described above, by using the two-unit fluidized bed type pyrolysis gasifier 35, the wood solid fuel is turned into combustible gas, and the char, tar, etc. generated at this time are removed from the combustion furnace 36. ．． While the heat medium is circulating between the gasifiers 38, it is sufficiently burned in the combustion furnace 3B. Further, the pressurized air discharged from the air compressor 33 is indirectly heated in the air heater 41 by the combustion waste gas from the combustion furnace 3B, and the pressurized air after this heating and the combustible air from the gasification furnace 38 are heated. Combustion gas is directly combusted through the duct eight 44, and the temperature of the combustion gas is raised to a turbine inlet temperature comparable to that of a normal gas turbine. Increase temperature to around ℃
- It is possible to obtain combustion gas for driving the turbine, which allows the gas turbine 32 to fully exhibit its intended performance.

Also, in this example device, as you can see, it is possible to convert the entire amount of wood solid fuel introduced into combustible gas.
As described above, in the case of full gasification, the power required to force the gas into the duct bar 44 by the gas compressor 43 becomes large, and there is a risk that it will not necessarily be efficient. Therefore, in the case of this embodiment configuration, during combustion and combustible gasification in the pyrolysis gasifier 35, the pressurized combustible gas from the gas compressor 43, that is, a part of the pressurized product gas, is transferred to the gasifier. 38, and as described above, the pressurized air from the air compressor 33 is indirectly heated to a temperature that is permissible from the viewpoint of material strength, and then the duct burner 44 burns the combustible gas. Direct combustion is carried out using gas, and it is sufficient to supply gas with a moderate temperature rise of 350°C at most, which reduces compressor power.
This makes it possible to further improve the efficiency of the device.

〔Effect of the invention〕

As described in detail above, according to the present invention, the power generating section which directly connects the pneumatic engine, the gas turbine, and the generator, and the duct bar disposed on the path to the gas turbine, the combustion furnace,
A two-column fluidized bed type pyrolysis gasifier is equipped with a gasification furnace to gasify wood solid fuel, and the wood solid fuel is converted into combustible gas by a two-column fluidized bed type pyrolysis gasification device. At the same time, the discharge air of the air compressor is indirectly heated by the combustion waste gas from the combustion furnace, and the combustible gas generated in the gasification furnace is pressurized, and these pressurized combustible gases and high pressure Since air is combusted by a duct burner and the combustion gas is used to drive a gas turbine, there is no risk of thermal effects that would impair the material strength of each part of the equipment up to the duct burner. On the other hand, by burning pressurized combustible gas and high-pressure air in the duct burner, sufficiently heated combustion gas can be obtained, allowing the gas turbine to fully demonstrate its desired performance. As a result, the energy efficiency of solid wood fuel can be maximized, and it has excellent features such as easy treatment of char, tar, etc. generated in solid wood fuel.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing an outline of a power generation device using solid fuel according to the present invention, and FIGS. 2 and 3 are block diagrams of each of the conventional devices described above. 31...Power generation section, 32...Gas turbine, 33
... air compressor, 34... departure tm, 35-...
・Dual fluidized bed type pyrolysis gasifier, 36... combustion furnace, 38... gasifier, 41... air heater,
42... Gas scrubber, 43... Gas compressor, 4
4...Duct burner, 45...Waste heat recovery boiler.

Claims (1)

[Claims] A two-column flow system that gasifies wood solid fuel by having a power generation section directly connected to an air compressor, a gas turbine, and a generator, a duct burner placed in the path to the gas turbine, a combustion furnace, and a gasification furnace. a bed-type pyrolysis gasifier; an air heater that indirectly heats the high-pressure air discharged from the air compressor using combustion waste gas from the combustion furnace; and a gas compressor that compresses the gas, the pressurized combustible gas and indirectly heated high-pressure air are guided to the duct burner and combusted, and the combustion gas drives the gas turbine. A power generation device that uses solid fuel.