JP3848029B2 - Power generation equipment using coal gasification gas - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide electric power generation equipment by coal-gasifying gas which can be supplied to the gas turbine equipment at the almost same temperature of clean fuel gas removing sulfur and impurities being supplied for a gas turbine as the gas temperature generating from a gasifying furnace. SOLUTION: Electric power generation equipment is equipped with: high temperature desulfurization equipment 2 for desulfurizing coal-gasifying gas generating from a coal-gasifying furnace 1 at a high temperature; water scrubber equipment 4 washing the coal-gasifying gas at the downstream side; and a heat regenerator 3 supplying a fuel gas recovered up to a temperature of a high temperature gas from the high temperature desulfurization equipment to a gas turbine equipment 5, carrying out alternately heat regeneration action regenerating heat by a high temperature gas from the high temperature desulfurization equipment 2 and heat radiation action radiating heat into gas from the water scrubber equipment.

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a power generation apparatus using coal gasification gas, in particular, a coal gasification furnace that gasifies coal by partial oxidation with oxygen or air (including oxygen-enriched air) under high temperature and high pressure, and generated coal gas. The present invention relates to a gas purification device to be purified and a power generation device that generates power by a combined power generation device including a gas turbine.
[0002]
[Prior art]
Since the gas generated in the coal gasification furnace contains impurities such as sulfur (H ₂ S, COS), ammonia, and gaseous metal substances, impurities in the gas are removed by a gas purifier before using it as a gas turbine fuel. There is a need.
[0003]
As a prior art, one using a wet gas purification apparatus shown in FIG. 7 is known. The coal gasification furnace 71 partially oxidizes coal with an oxidizing agent of oxygen or air to gasify the coal. The coal gas generated from the gasification furnace 71 is about 400 ° C. or higher, and this coal gas temperature is lowered to a normal temperature or lower through an indirect heat exchange device (shell-and-tube type, plate type, etc.) 72, and a water scrubber device 73 etc. In this system, ammonia is removed and impurities in the gas are removed, and then the wet desulfurization device 74 is used to remove the sulfur content using the desulfurization liquid, which is then supplied to the gas turbine device 75. Even if the gas temperature after desulfurization desulfurized by the wet desulfurization device 74 by the indirect heat exchange device 72 is recovered, the gas temperature that can be supplied to the gas turbine 75 is about 300 ° C. from the viewpoint of device size and economy. is there.
[0004]
FIG. 8 shows a system using a dry gas refining device. The coal gas generated from the coal gasification furnace 81 is about 400 ° C. or higher, and is passed through a high-temperature desulfurization device 82 in this high temperature state to obtain a desulfurizing agent (iron oxide, Zinc oxide, titanium-zinc compound, etc.), and the sulfur content is removed and supplied to the gas turbine device 83. In this case, the fuel gas can be supplied to the gas turbine 83 at a temperature approximately the same as the outlet temperature of the coal gasification furnace 81 (400 ° C. or higher). Impurities such as metal substances cannot be removed.
[0005]
9 shows that an indirect heat exchange device (shell and tube type, plate type, etc.) 93 and a water scrubber device 94 are installed on the downstream side of the dry gas purification device 92 described in FIG. This system adds a function to remove medium impurities. The indirect heat exchange device 93 attempts to recover the gas temperature after removing the ammonia component and the impurities in the gas by the water scrubber device 94. From the viewpoint of the function, device size, and economy of the indirect heat exchange device 93, the gas turbine device 95 is used. The gas temperature that can be supplied to is about 300 ° C.
[0006]
[Problems to be solved by the invention]
In a power generation apparatus using coal gasification, the higher the inlet temperature of the fuel gas gas turbine, the higher the thermal efficiency of the entire system. For this reason, the hot gas purification system of FIG. 8 has been proposed. Although the operating temperature of this apparatus is about 400 ° C. or higher, gaseous impurities cannot be removed. When impurities are included in the fuel gas, there are problems such as damage to the gas turbine blades and the environmental impact of the gas turbine exhaust gas.
[0007]
In addition, when removing the impurities in the gas, when the water scrubber employed in FIG. 7 or FIG. 9 is used, the water scrubber operating temperature is a maximum of 220 ° C. or less, so an indirect heat exchanger is used. Although the temperature of the fuel gas supplied to the turbine is recovered, a practical temperature is about 300 ° C., and it cannot be recovered to the coal gasification furnace outlet temperature (400 ° C. or more).
[0008]
Further, in the indirect heat exchanger, a gas impurity precipitation phenomenon (ammonium chloride or the like) occurs in the heat exchanger in the process of lowering the gas temperature, so that the apparatus cannot be operated continuously. In order to raise the temperature of the gas supplied to the gas turbine, the size of the indirect heat exchanger must be increased significantly.
[0009]
In order to solve the above problems, the object of the present invention is to provide a gas turbine at a temperature approximately equal to the temperature of a coal gasification gas generated from a coal gasification furnace by using a clean gas turbine supply fuel gas desulfurized and impurities removed. It is to provide a power generation apparatus using coal gasification gas that can be supplied to the plant.
[0010]
[Means for Solving the Problems]
The above objects are a high temperature desulfurization device for desulfurizing coal gasification gas generated from a coal gasification furnace at a high temperature, a water scrubber device for washing the coal gasification gas downstream, and a high temperature gas from the high temperature desulfurization device. The heat storage operation for storing heat by directly flowing the gas and the heat release operation for dissipating heat to the gas by directly flowing the gas from the water scrubber device are alternately performed to recover the fuel gas recovered to the high temperature gas temperature from the high temperature desulfurization device. This is achieved by providing a heat storage type heat exchange device that supplies the gas turbine device.
[0011]
Moreover, the said objective is achieved by the said heat storage type heat exchange apparatus being provided with the several heat storage body and the control means which switches each heat storage body to heat storage operation | movement, thermal radiation operation | movement, and standby.
[0012]
The above-mentioned object is achieved by operating the heat storage type heat exchange device so that the outlet temperature of the heat storage body is substantially equal to the high temperature gas temperature from the high temperature desulfurization device at the end of the heat storage operation. The
[0013]
According to the above means, the coal gasification gas is removed from the sulfur content by contacting the coal gasification gas with a desulfurization agent by a high temperature desulfurization apparatus in a high temperature state (about 400 ° C. or more). The high-temperature gas (approximately 400 ° C or higher) desulfurized by the high-temperature desulfurization device is washed directly with the heat storage body of the heat storage type heat exchange device and stored in the downstream water scrubber device, and is washed with water. Removal and removal of impurities in the gas are performed. The heat storage of the heat storage body of the heat storage type heat exchange device is continued until the temperature of the heat storage body outlet becomes equal to the high temperature gas temperature from the high temperature desulfurization device (about 400 ° C. or higher). The clean gas from which impurities have been removed by the downstream water scrubber device has its temperature lowered by the water washing treatment, but directly flows through the heat storage body that has been heated and stored up to the same temperature as the high-temperature gas (approximately 400 ° C. or higher). The gas temperature is recovered by releasing heat from the heat storage body. Due to the heat dissipation of the heat accumulator, the gas temperature is easily recovered to a high efficiency (approximately 400 ° C. or higher) and is supplied to the gas turbine apparatus in a high temperature state with high efficiency.
[0014]
A plurality of heat storage elements of the heat storage type heat exchange device are arranged side by side, and by switching between them, the heat storage operation and the heat radiation operation are repeated alternately, and at the end of the heat storage operation, the heat storage body outlet temperature becomes the high temperature gas temperature from the high temperature desulfurization device. The temperature of the heat storage is increased to the same level, and the gas temperature from the water scrubber device is recovered to the same level as the high temperature gas temperature from the high temperature desulfurization device by the heat radiation of the heat storage body, and the gas turbine is heated to a high temperature (about 400 ° C). The above can be supplied as clean fuel gas. By switching between a plurality of heat storage bodies, one can be controlled continuously and independently from each other by switching so that one is in the heat storage operation, the other is in the heat dissipation operation, and is in standby if necessary.
[0015]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[0016]
FIG. 1 is a block diagram showing a configuration of a power generation apparatus using coal gasification gas according to an embodiment of the present invention.
[0017]
In the figure, 1 is a gasification furnace that reacts coal with an oxidant to generate a high-temperature combustible gas. The gas generated in the coal gasification furnace 1 is sulfur (H ₂ S, COS), ammonia, gaseous Since impurities such as metal substances are included, it is necessary to remove impurities in the gas with a gas purifier before using the gas turbine fuel. The high-temperature gas desulfurization apparatus 2 is made by contacting the high-temperature coal gasification gas generated from the gasification furnace 1 with a desulfurization agent (iron oxide, zinc oxide, titanium-zinc compound, etc.) in a high temperature state (about 400 ° C. or higher). Remove minutes.
[0018]
Further, the coal gasification gas is processed by the water scrubber device 4 disposed on the downstream side through the heat storage type heat exchange device 3. The water scrubber device 4 rinses the introduced gas to remove ammonia in the gas and impurities such as gaseous metal substances. The gas whose temperature has been lowered by the water washing treatment passes through the regenerative heat exchange device 3 and recovers the gas temperature to a temperature approximately equal to the high temperature gas temperature (about 400 ° C. or more) of the high temperature desulfurization device 2, and is clean. As a high-temperature fuel gas, it is supplied to the gas turbine device 5 and used for combined power generation.
[0019]
FIG. 2 is a detailed configuration diagram of the coal gasification combined power generation device. In the gasification furnace 1, the supplied coal 11 is reacted with oxygen, air, or oxygen-enriched air supplied as the oxidant 12 under high temperature and high pressure to generate high temperature combustible gas. During the reaction process, most of the ash content in the coal is discharged out of the system from the gasifier as molten ash 13. On the other hand, since the generated coal gasification gas has a high temperature (about 1000 ° C.), it is recovered as steam by the syngas cooler (CGC) 6 and reaches the operating temperature of the high-temperature desulfurization apparatus 2 (about 380 ° C. to 640 ° C.). To be cooled.
[0020]
The steam generated by the syngas cooler 6 merges with the steam generated in the exhaust heat recovery boiler (HRSG) 7 of the combined power generation apparatus, and generates power by the steam turbine 8.
[0021]
Since the generated coal gasification gas contains char (unreacted carbon, hydrogen, ash contained in coal, etc.) as a solid, the cyclone filter 9 separates the gas and char and collects them. The char is re-entered into the gasifier 1. The combustible components in the coal gasification gas from which the solid content has been removed are CO, H ₂ , CH _4, etc., but contain impurities (H ₂ S, COS, NH ₃ , Cl, etc.) originating from the coal. To do. The gas after the char separation is guided to the high-temperature desulfurization apparatus 2, and the sulfur content (H ₂ S, COS) in the gas is removed at a high temperature. The removed sulfur content is recovered by the gypsum absorption tower 10. The outlet gas temperature of the high temperature desulfurization apparatus 2 is maintained at about 400 ° C. or higher.
[0022]
Impurities other than sulfur (NH ₃ , Cl, other gaseous metal substances, etc.) are contained in the exit gas of the high temperature desulfurization device 2 and must be removed. It introduces into the heat exchange device 3. The heat storage type heat exchange device 3 includes a plurality of heat storage towers that can be switched between heat storage, heat dissipation, and standby, and the switched heat storage tower is in direct contact with a heat storage body (such as ceramic) through which desulfurized coal gas flows in the tower. By doing so, heat is exchanged and the heat storage material is heated and stored. The outlet gas temperature flowing out of the heat storage tower changes from about 70 ° C. to about 420 ° C. of the high-temperature gas temperature of the high-temperature desulfurization device 2 depending on the heat storage state of the heat storage body.
[0023]
The coal gasification gas that has passed through the heat storage type heat exchange device 3 is sent to a water scrubber device (water washing tower) 4 to be washed with water, and impurities (NH ₃ , Cl, etc.) in the gas are removed. The clean coal gasification gas that has passed through the water scrubber device 4 flows again into the heat storage type heat exchange device 3 and directly contacts the heat storage body in the switched radiating tower and exchanges heat by heat dissipation and heats it. The high-temperature gas is sent to the gas turbine 5 after being heated to the same temperature as the outlet temperature (about 400 ° C. or higher) of the high-temperature desulfurization apparatus 2 where the heat storage body is heated.
[0024]
In this way, the gas turbine device 5 is supplied with clean high-temperature coal gasification gas from which impurities have been removed, and the fuel gas is operated to generate power. Exhaust gas from the gas turbine device 5 is sent to the HRSG 7 to generate steam and then discharged from the chimney 14 to the outside of the system. The steam generated by the HRSG 7 merges with the steam generated by the syngas cooler 6 to drive the steam turbine 8 to generate power.
[0025]
3-6 is explanatory drawing of the function of a thermal storage type heat exchange apparatus, and shows embodiment in the case where there are several thermal storage bodies from the 1st tower to the 4th tower. The first tower to the fourth tower are arranged in parallel, and each tower alternately performs heat storage, heat radiation and standby operations from (1) to (4) below by switching valves.
[0026]
(1) During the operation of exchanging heat with the high-temperature gas from the high-temperature desulfurization device 2 (heat storage operation of the heat storage body) and introducing the outlet gas to the water scrubber device 4 (2) The heat storage body is heated to the high-temperature gas temperature of the high-temperature desulfurization device (3) Clean coal gasification gas heated to the same temperature as the high temperature gas of the high temperature desulfurization device 2 by heat exchange with the temperature lowering gas from the water scrubber device 4 (heat dissipation operation of the heat storage body) (4) Waiting in a state where the heat storage body is not heated FIG. 3 shows that the first tower opens the valves A and D, and the second tower is in the heat storage operation of (1). During the standby of (2), the third tower opens the valves J and K, during the heat radiation operation of (3), and the fourth tower shows the standby of (4).
[0027]
In the first tower during the heat storage operation, the inlet side becomes hot (white portion in the figure) due to the high temperature gas from the high temperature desulfurization apparatus 2, but the flowing gas is gradually lowered in temperature and introduced into the water scrubber apparatus 4 from the outlet. As the time elapses, the heat storage high temperature state of the heat storage body gradually spreads to the outlet side, and the entire first tower is stored to a temperature similar to the high temperature gas from the high temperature desulfurization apparatus 2 (about 400 ° C. or higher). . In addition, the temperature of the third tower during the heat radiation operation is lowered on the inlet side by the temperature lowering gas from the water scrubber device, but the gas flowing through the heat storage body heated at a high temperature is gradually heated, and the outlet side is in a high temperature state (about 400 ° C). The above is recovered and converted into a high-temperature clean gas and supplied to the gas turbine device 5. However, in this third tower, the temperature drop (black portion in the figure) gradually spreads toward the outlet side with the passage of time, and the heat dissipation of the heat storage body proceeds.
[0028]
FIG. 4 shows the end of the heat storage of the heat storage body of the first tower, and the outlet gas temperature is at the same temperature (about 400 ° C. or higher) as the high temperature gas temperature from the high temperature desulfurization device 2 (of the water scrubber device 4). (Detected by inlet gas temperature) is the end point of the heat storage operation. By introducing high temperature gas from the high temperature desulfurization apparatus 2 and storing heat up to this stage, impurities in the coal gasification gas become ammonium chloride and the like, and are once deposited on the heat storage body (precipitation temperature is 300 ° C. or less). The entire heat storage body is heated to the state of the first column in FIG. 4 (high-temperature gas temperature of the high-temperature desulfurization apparatus, about 400 ° C. or higher). Impurities such as ammonium are evaporated and sent to the downstream water scrubber device 4 where they are dissolved and removed by washing with water, so that the coal gasification gas is clean.
[0029]
On the other hand, the heat storage body of the first tower in the heat storage operation in which high-temperature gas is introduced from the high-temperature desulfurization apparatus 2 to perform heat exchange is stored by setting the temperature of the heat storage body to the impurity sublimation temperature or higher in the final stage of the heat storage operation. Since there is no impurity deposition on the body, porous clogging due to precipitation of impurities in the heat storage body is prevented, and scattering of precipitates on the heat storage body to the clean gas from the water scrubber device 4 during heat radiation operation is prevented, A high temperature clean gas can be supplied to the gas turbine device 5.
[0030]
Further, in FIG. 4, the temperature of the heat storage body in the third tower is also lowered, and the outlet side temperature cannot maintain the high temperature gas temperature from the high temperature desulfurization apparatus 2, so that the high temperature gas (about 400 ° C.) to the gas turbine apparatus 5 can be maintained. This is the end time of the heat dissipation operation where supply of the above is impossible.
[0031]
In FIG. 5, in order to switch the tower for storing heat without stopping the gas flow from the first tower to the fourth tower, the valves Q, T, M, P are gradually opened, and the valves A, D, W are accordingly opened. , X gradually close. Further, in order to switch the tower for radiating heat from the third tower to the second tower, the valves R, F and G are gradually opened, and the valves J, K and V are gradually closed.
[0032]
FIG. 6 shows that the heat storage operation has been switched to the fourth tower and the heat radiation operation has been switched to the second tower, and the high temperature gas is supplied from the high temperature desulfurization apparatus 2 to the fourth tower and supplied to the water scrubber apparatus 4 while storing heat. Clean gas is supplied from the water scrubber device 4 to the two towers, heated by heat radiation from the heat storage body, and supplied to the gas turbine device 5 as high-temperature gas. At this time, the first tower is on standby with the heat storage body heated to a high temperature, and the third tower is on standby with the heat storage body not heated.
[0033]
In the fourth tower during the heat storage operation, the inlet side becomes hot due to the high-temperature gas from the high-temperature desulfurization apparatus 2, but the flowing gas gradually decreases in temperature and the outlet side is in a temperature-decreasing state. However, the high temperature state due to heat storage of the heat storage body gradually spreads to the outlet side as time passes. On the other hand, in the second tower during the heat radiation operation, the temperature on the inlet side is lowered by the temperature lowering gas from the water scrubber device 4, but the flowing gas is gradually heated by the heat radiation of the high-temperature heat accumulator and the high temperature state is recovered on the outlet side. The gas is supplied to the gas turbine device 5. However, the temperature-decreasing part of the heat storage body gradually spreads toward the outlet side as time elapses.
[0034]
At the end of the heat storage operation of the fourth tower during the heat storage operation, the heat storage operation is switched from the fourth tower to the third tower, and the second tower during the heat dissipation operation is switched to the first tower. Note that switching of the tower for the heat radiation operation is performed by detecting the outlet gas temperature of the second tower during the heat radiation operation to supply the high-temperature gas to the gas turbine device 5, until it reaches the high-temperature gas temperature of the high-temperature desulfurization apparatus 2. It is necessary to switch at a point before it becomes unrecoverable. Switching between the heat storage operation and the heat radiation operation may be performed independently of each other.
[0035]
Since heat exchange is performed by directly flowing high-temperature gas and low-temperature gas to a heat storage body that has been switched between heat storage operation and heat dissipation operation, extremely efficient heat exchange can be performed, and the gas turbine device is always in a high-temperature state. By supplying clean fuel gas, it is possible to perform highly efficient power generation.
[0036]
【The invention's effect】
As described above, according to the present invention, clean and high-temperature coal gasification gas can be supplied to the gas turbine device, and high efficiency similar to that of a power generation device using coal gas using high-temperature gas refining can be obtained. Gas turbine blade damage due to quality and environmental impact substances in gas turbine exhaust gas can be reduced, and equipment costs can be reduced compared to systems using tube-type, plate-type, and heat transfer surface type heat exchangers. effective.
[Brief description of the drawings]
FIG. 1 is a block diagram of an embodiment of the present invention.
FIG. 2 is a detailed configuration diagram of a combined power generation apparatus according to an embodiment of the present invention.
FIG. 3 is a functional explanatory diagram of a heat storage type heat exchange device.
FIG. 4 is a functional explanatory diagram of a heat storage type heat exchange device.
FIG. 5 is a functional explanatory diagram of a heat storage type heat exchange device.
FIG. 6 is a functional explanatory diagram of a heat storage type heat exchange device.
FIG. 7 is a block diagram of a conventional power generator.
FIG. 8 is a block diagram of a conventional power generator.
FIG. 9 is a block diagram of a conventional power generator.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Gasification furnace, 2 ... High temperature desulfurization apparatus, 3 ... Thermal storage type heat exchange apparatus, 4 ... Water scrubber apparatus, 5 ... Gas turbine power generation apparatus, 6 ... Syngas cooler, 7 ... HRSG, 8 ... Steam turbine power generation apparatus, 9 ... cyclofilter, 10 ... gypsum absorption tower, 11 ... pulverized coal supply, 12 ... gasification agent supply, 13 ... slag, 14 ... chimney.

Claims (5)

In a power generation apparatus that performs combined power generation by purifying coal gasification gas generated from a gasification furnace and supplying it to a gas turbine, a high-temperature desulfurization apparatus that desulfurizes the coal gasification gas generated from the gasification furnace in a high temperature state, and the coal A water scrubber device that flushes the gasified gas downstream, a heat storage operation that stores heat by directly flowing the high-temperature gas from the high-temperature desulfurization device, and a heat release that dissipates heat to the gas by directly flowing the gas from the water scrubber device. And a regenerative heat exchanger that supplies the gas turbine device with a gas that is alternately operated and that has recovered the gas from the water scrubber device to a temperature that is approximately the same as the high-temperature gas temperature from the high-temperature desulfurization device. A power generation apparatus using coal gasification gas. The power generation apparatus using coal gasification gas according to claim 1, wherein the heat storage type heat exchange device includes a plurality of heat storage bodies and a control unit that switches each heat storage body between a heat storage operation, a heat radiation operation, and standby. A power generation apparatus using coal gasification gas. 3. The power generation apparatus using coal gasification gas according to claim 2, wherein the heat storage body of the heat storage heat exchanger is on standby while the heat storage body is heated to the high temperature gas temperature of the high temperature desulfurization apparatus, A power generation apparatus using coal gasification gas, wherein there is a waiting state in which the body is not heated. The power generation apparatus using coal gasification gas according to any one of claims 1 to 3, wherein the heat storage type heat exchange device has a high temperature from the high-temperature desulfurization device when an outlet temperature of the heat storage body during the heat storage operation ends. A power generation apparatus using coal gasification gas, which is operated so as to have a temperature substantially equal to a gas temperature. The power generation apparatus using coal gasification gas according to any one of claims 1 to 3, wherein the heat storage type heat exchange device has a high temperature from the high-temperature desulfurization device when the outlet temperature of the heat storage body during the heat dissipation operation ends. A power generation apparatus using coal gasification gas, which is operated so as not to be below a gas temperature.

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