JPH11246875A - Gasification-complex power generation system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a gasification-complex generation system capable of recovering heat by means of a gasifying-cooling apparatus to sufficiently low temperatures, supplying dust-removed gas to a dry desufurization equipment after the temperature of the gas sufficiently rises, without fear of internal clogging or dust flow into the dry desulfurization equipment and/or a gas turbine and furthermore, enabling the system itself to be made compact. SOLUTION: This gasification-complex power generation system consists of a gasifying-cooling apparatus A for gasifying and cooling fuel to produce crude gas, a dry desulfurization equipment B for dry-desulfurizing the crude gas to produce purified gas and a gas turbine complex power generation equipment C for complex power generation through burning the purified gas; wherein, a dust-removing purifier D for removing dust, heavy metals and alkaline components is equipped between the gasifying-cooling apparatus A and the dry desulfurization equipment B. The dust- removing purifier D consists of a scrubbing apparatus 12 for scrubbing the crude gas with cleaning water and a crude gas-heating apparatus 14 for heating the dust- removed gas coming out of the scrubbing apparatus with high-temperature steam. The high-temperature steam is supplied from a waste heat-recovering boiler 8 and set at a higher pressure than that of the dust-removed gas.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an integrated gasification combined cycle power plant which gasifies a hydrocarbon fuel to be used as a fuel for a gas turbine, and more particularly to a combined gasification combined cycle power plant provided with a dry desulfurization unit.

[0002]

2. Description of the Related Art FIG. 2 is an overall flow chart of a conventional integrated gasification combined cycle power plant equipped with a dry desulfurization unit. In this figure, A is a gasification / cooling facility, which converts a crude gas gasified in a gasification furnace 1 into a radiation crude gas cooler 2 and a convective crude gas cooler 3.
And supply it to the dry desulfurizer B. The convection crude gas cooler 3 has an economizer and an evaporator, and supplies water to the crude gas cooler and supplies excess steam to the exhaust heat recovery boiler 8.

In this example, the dry desulfurization apparatus B comprises a plurality of fixed-bed desulfurization towers to remove sulfur (H 2 S, etc.) in the crude gas. C is a gas turbine combined cycle power plant, and includes a gas turbine 7, an exhaust heat recovery boiler 8,
The gas turbine 7 and the steam turbine 9 generate combined power by burning the purified gas.

Further, in a conventional gasification combined cycle power plant equipped with a dry desulfurization unit, as shown in FIG. 2, dust and heavy metals (halogen, mercury, etc.) are interposed between a gasification / cooling unit A and a dry desulfurization unit B. ), A dust removing and purifying apparatus D for removing an alkali component is provided. In other words, dust, heavy metals, and alkali components cause catalyst deterioration and clogging of the desulfurization tower, and damage the gas turbine blades.
Need to be removed.

[0005]

As shown in FIG. 2, in the above-mentioned dust removing and refining apparatus D, a conventional gas gas heat exchanger (coarse gas heater 4) for exchanging heat between a coarse gas and a dust removing gas is used.
And a scrubber device 5 that circulates cleaning water inside is used. The scrubber device 5 removes dust, heavy metals, and alkali components by washing with water, and the coarse gas heater 4 uses a high temperature suitable for the dry desulfurization device B (for example, 400 ° C. or higher: t4).

That is, in the conventional integrated gasification combined cycle facility, the crude gas flowing into the coarse gas heater 4 is kept at a high temperature (for example, about 460 to 520 ° C .: t 2), and the coarse gas heater 4 reduces the dust removal gas. By heating to 400 ° C. (t4), the performance of the dry desulfurization apparatus B was maintained and the system efficiency was improved. In this figure, t1 is about 1300-1.
500 ° C, t3 is about 140-150 ° C, t5 is about 400
° C, t6 is about 230 ° C, and t6 is the temperature of the crude gas after cooling.

The crude gas heater 4 is a shell-and-tube type heat exchanger, through which the crude gas flows.
Dust removal gas flows on the shell side. However, such a conventional combined gasification power plant has the following problems. The coarse gas contains a large amount of dust (dust and dust), and the dust may accumulate and stick to stop the operation of the power generation equipment. Also, for this measure, it is essential to provide a suit blower or control the flow rate, and the device becomes complicated. High-speed dust may create a through hole in the tube, and if a through hole is formed, dust, heavy metals,
An alkali component or the like flows into the dry desulfurization device B or the gas turbine, and may cause fatal damage to the catalyst, the turbine blade, and the like. Since it is a gas-gas heat exchanger, the heat transfer coefficient is small and large. The discharge temperature of the crude gas from the gasification / cooling facility A is high, and the amount of recovered heat is reduced.

The present invention has been made to solve the above-mentioned problems. That is, an object of the present invention is to enable heat recovery to a sufficiently low temperature in the gasification / cooling facility A, to sufficiently raise the temperature of the dust removal gas, and to supply the gas to the dry desulfurization apparatus B,
It is another object of the present invention to provide a gasification combined cycle power generation facility that does not have a risk of clogging of the inside or dust and the like into a dry desulfurization apparatus or a gas turbine, and that can further reduce the size of the facility.

[0009]

According to the present invention, a gasification / cooling system A for gasifying and cooling a fuel to generate a crude gas is provided.
Gasification combined power generation equipment comprising: a dry desulfurization device B for dry desulfurization of a crude gas to produce purified gas; and a gas turbine combined power plant C for combusting the purified gas for combined power generation. A dust purifier D for removing dust, heavy metals and alkali components is provided between the equipment A and the dry desulfurizer B. The dust purifier D is a scrubber for cleaning crude gas with cleaning water. And a coarse gas heater for heating the dust removal gas exiting the scrubber device with high-temperature steam, and the high-temperature steam is set to a higher pressure than the dust removal gas. A power generation facility is provided.

According to the configuration of the present invention, a scrubber device for cleaning the coarse gas with the cleaning water is installed on the upstream side of the coarse gas heater, and the scrubber device (operating temperature is about 140 to 15).
(0 ° C), the crude gas leaving the gasification / cooling facility A directly flows in, so that the crude gas can be cooled below the operating temperature of the scrubber device, and the gasification / cooling facility A can recover heat to a sufficiently low temperature. it can.

Further, since a coarse gas heater for heating the dust removal gas with high-temperature steam set to a pressure higher than the dust removal gas is provided downstream of the scrubber device, the dust removal gas is heated to about 400 ° C. by the coarse gas heater. Heating can be performed up to the above (t4). Further, since the pressure of the high-temperature steam is higher than the pressure of the dust removing gas, even if a hole is opened in the heat exchange section (tube) of the coarse gas heater, only the boiler water flows into the coarse gas side, which is fatal. There is no influence, and the temperature of the dust removal gas can be increased while protecting the dry desulfurization device and the gas turbine, thereby achieving both reliability and high efficiency.

Further, the heating side of the crude gas heater is high-temperature steam, and by condensing the steam inside, the condensed heat transfer having a high heat transfer rate can be used, and the gas-gas heat exchange and the liquid-gas heat exchanger can be used. As compared with the above, the heat transfer coefficient can be increased and the device can be made more compact.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below with reference to the drawings. In the drawings, common portions are denoted by the same reference numerals, and redundant description is omitted. FIG. 1 is an overall flowchart showing the integrated gasification combined cycle facility of the present invention. In this figure, a combined gasification combined cycle system of the present invention includes a gasification and cooling facility A for gasifying and cooling fuel to produce a crude gas, and a dry desulfurization apparatus B for dry desulfurization of a crude gas to a purified gas. And a gas turbine combined cycle power plant C for combusting the purified gas to perform combined cycle power generation. The equipment constituting the gasification / cooling facility A, the dry desulfurization unit B, and the gas turbine combined cycle facility C is the same as the conventional combined gasification combined cycle facility shown in FIG.

In FIG. 1, an integrated gasification combined cycle system according to the present invention is provided between a gasification / cooling system A and a dry desulfurization unit B.
The apparatus is provided with a dedusting / purifying device D for removing dust, heavy metals and alkali components. The dust removing and refining apparatus D includes a scrubber device 12 for cleaning the crude gas with cleaning water, and a coarse gas heater 14 for heating the dust removal gas exiting the scrubber device 12 with high-temperature steam. The high-temperature steam is supplied from the exhaust heat recovery boiler 8 constituting the gas turbine combined cycle power plant C, and is set at a pressure higher than the dust removal gas.

The scrubber device 12, as shown in FIG.
The crude gas (temperature of about 230 ° C .: t 2) which is installed on the upstream side of the crude gas heater 14 and exits the gasification / cooling facility A directly flows in. The scrubber device 12 holds cleaning water, and the cleaning water is circulated and sprayed inside by a device not shown. With this configuration, the crude gas and the cleaning water are brought into direct contact, and the dust contained in the crude gas,
Heavy metals and alkali components are taken into the washing water side and removed. Dust and the like taken into the cleaning water side are extracted from the lower part as discharge water, and are treated by a device (not shown).

With this configuration, the gasification and cooling equipment A is directly connected to the scrubber device 12 (operating temperature is about 140 to 150 ° C.).
The crude gas that has flowed out of the gas flow is cooled, so that the crude gas can be cooled to a temperature lower than the operating temperature of the scrubber device, and the gasification / cooling facility A can recover heat to a sufficiently low temperature.

The coarse gas heater 14 is a liquid gas heat exchanger (for example, a shell and tube type), and is provided downstream of the scrubber device 12. Further, since the dust removal gas is heated by high-temperature steam set at a pressure higher than that of the dust removal gas, the coarse gas heater 14 reduces the dust removal gas to, for example, about 4%.
Heating can be performed up to 00 ° C. or more (t4). Furthermore,
Since the pressure of the hot steam is higher than the pressure of the dust removal gas,
Even if a hole is opened in the heat exchange section (tube) of the crude gas heater 14, only boiler water flows into the crude gas side, and there is no fatal effect, and dust is removed while protecting the dry desulfurization unit and the gas turbine. The temperature of the gas can be raised, achieving both reliability and high efficiency.

Further, by supplying high-temperature steam to be supplied to the crude gas heater 14 from the exhaust heat recovery boiler 8 constituting the gas turbine combined cycle power plant C, the amount of heat required in the exhaust heat recovery boiler 8 increases. As described above, since the heat can be recovered to a sufficiently low temperature in the gasification / cooling facility A, the overall thermal efficiency can be kept high. Furthermore,
The heating side of the crude gas heater is high-temperature steam, and by condensing it inside, it is possible to use condensation heat transfer with a high heat transfer rate, compared to gas-gas heat exchange and liquid-gas heat exchangers. The heat transfer coefficient can be increased and the device can be made compact.

In the above-described configuration, the temperature of each unit is calculated as a result of a system calculation performed as an example.
~ 1500C, t3: about 140-150C, t5: about 4
00C, t7: about 450-530C. Here, t7 is the temperature of the high-temperature steam.

It should be noted that the present invention is not limited to the above-described embodiment, but can be variously modified without departing from the gist of the present invention.

[0021]

As described above, according to the present invention, the crude gas heater 1 is disposed between the scrubber device 12 and the dry desulfurization device B.
Since the high-temperature steam generated in the exhaust heat recovery boiler 8 is used as the heat source, the coarse gas heater 14 becomes a steam heater, which can be downsized. It is characterized in that trace metals and halogen compounds in gas which cannot be removed by a ceramic filter or the like can be sufficiently removed.

That is, the integrated gasification combined cycle facility of the present invention can recover heat to a sufficiently low temperature in the gasification and cooling facility A,
The temperature of the dust removal gas can be sufficiently raised and supplied to the dry desulfurization apparatus B, and there is no danger of clogging of the inside or dust and the like flowing into the dry desulfurization apparatus or the gas turbine, and the equipment can be made more compact. , Etc. have excellent effects.

[Brief description of the drawings]

FIG. 1 is an overall flowchart showing an integrated gasification combined cycle facility of the present invention.

FIG. 2 is a flow diagram of a combined gasification combined cycle facility equipped with a conventional dry desulfurization device.

[Explanation of symbols]

 Reference Signs List A Gasification / cooling equipment B Dry desulfurization equipment C Gas turbine combined power generation equipment D Dust removal and purification equipment 1 Gasification furnace 2 Radiation coarse gas cooler 3 Convection crude gas cooler 4 Coarse gas heater 5 Scrubber device 7 Gas turbine 8 Discharge Heat recovery boiler 9 Steam turbine 12 Scrubber device 14 Crude gas heater

Continued on the front page (51) Int.Cl. ⁶ Identification code FI C10J 3/48 F01K 23/10 T C10K 1/02 F02C 3/28 F01K 23/10 B01D 53/34 119 F02C 3/28 136Z

Claims (1)

[Claims] 1. A gasification / cooling facility A for producing a crude gas by gasifying and cooling a fuel, a dry desulfurization apparatus B for producing a crude gas by dry desulfurization of a crude gas, and a complex by burning the refined gas In the combined gasification combined cycle facility including the combined gas turbine combined cycle facility C and the gasification and cooling facility A and the dry desulfurization unit B, dust,
The apparatus is provided with a dedusting / purifying device D for removing heavy metals and alkali components. The dedusting / purifying device D is provided with a scrubber device for cleaning coarse gas with cleaning water, and a high-temperature steam for removing dust gas leaving the scrubber device. And a high temperature steam set at a pressure higher than that of the dust removal gas.