JP3836014B2 - Fuel gasification combined power generation system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a fuel gasified compound power generation system capable of stably performing desulfurization reaction. SOLUTION: Measuring devices formed of a flowmeter 8, a pressure gauge 9, and a thermometer 10 is installed in a pipe 4 for communicating a gasified furnace 7 with desulfurization equipment 6. These measuring devices measure the flow, pressure, and temperature of fuel gas passing the pipe 4. The physical quantities thereof are converted 11 to the flow velocity of the fuel gas by calculation. The flow velocity of the fuel gas obtained as above is taken into a control device 12. The control device 12 controls the supplied amounts of fuel 1 and oxidizer 2 fed to the gasified furnace 7 according to the flow velocity of the fuel gas obtained as above.

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a combined fuel gasification power generation system. More specifically, the present invention relates to a combined fuel gasification power generation system capable of stably performing a desulfurization reaction in a desulfurization facility even when a load fluctuates, and a fuel gasification composite having a low pressure loss. The power generation system.
[0002]
[Prior art]
FIG. 4 is a block diagram showing a conventional combined fuel gasification combined power generation system. The fuel gasification combined cycle system is roughly gasifier facility 41, desulfurization 4 2, and composed of a gas turbine equipment 43. The gasifier facility 41 is for generating a fuel gas. The gasifier 47 is supplied with the fuel 44 and the oxidant 45 by the pressure of the nitrogen gas 46, and the unburned fuel fines in the generated gas. And a dust removing device 48 for removing the dust. The oxidant 35 may be air extracted from the compressor 49 of the gas turbine or oxygen separated therefrom by a separation device.
[0003]
The fuel gas generated in the gasifier facility 41 passes through the gasifier pressure control valve 50 and enters the desulfurization facility 42. In the desulfurization facility 42, a COS converter 51 is provided to remove sulfide from the fuel gas, and the COS in the fuel gas is converted into H ₂ S by the catalyst. Thereafter, the gas cooling tower 54 the water by the pump 52 and 53 is circulated, likewise the gas washing tower 55, H ₂ H ₂ S absorption tower 56 S absorbing liquid filled water is circulated passing through the fuel gas.
[0004]
Since the fuel gas that has passed through these reaction towers has a low temperature, the temperature is raised by the gas-gas heaters (GGH) 57 and 58 with the fuel gas that is in a high temperature state before entering the reaction tower. The absorption liquid which absorbed H ₂ S in the H ₂ S absorption tower 56 is the absorbent regenerator 59, H ₂ S is removed, again returned to the H ₂ S absorption tower 56. The removed H ₂ S is then transferred to the gypsumizing step 60.
[0005]
The fuel gas that has passed through the desulfurization facility 42 is sent to the gas turbine facility 43. Specifically, the pressure and flow rate of the fuel gas are adjusted by a pressure control valve 63 and a flow rate control valve 64 provided upstream of the combustor 62 of the gas turbine 61. Then, the gas turbine 61 rotates the turbine using the fuel gas adjusted as described above as fuel, and rotates the generator 65 connected to the turbine shaft. In addition, although not shown here, the case of using a combined plant that uses not only a gas turbine but also a steam turbine as power generation equipment is increasing.
[0006]
Thus, in the combined fuel gasification power generation system in which the gasification furnace 47, the desulfurization equipment 42, and the gas turbine 61 are installed in this order, the load follow-up is performed by opening and closing the flow rate control valve 64 of the gas turbine 61 according to the load. Control is performed. Also known is a technique that contributes to load follow-up control by opening and closing the gasifier pressure control valve 50 according to the deviation between the pressure of the gasifier 47 and the set pressure value (Japanese Patent Laid-Open No. 10-299507).
[0007]
[Problems to be solved by the invention]
However, in the conventional combined fuel gasification combined power generation system, when the power generation output is changed or the load on the system changes, the load on the system naturally varies. In such a case, the gasifier pressure control valve 50 opens and closes so as to adjust the pressure of the gasifier 47, so that the amount of gas flowing into the desulfurization facility 42 varies. Further, in the vicinity of the gas turbine 61, the pressure control valve 63 and the flow rate control valve 64 adjust the pressure and flow rate at the gas turbine inlet, so that the amount of fuel gas flowing out from the desulfurization facility 42 varies.
[0008]
For this reason, the pressure and flow rate of the desulfurization equipment 42 located between the gasification furnace 47 and the gas turbine 61 are not controlled, and fluctuations occur. In the reaction tower, the liquid flows downward and the gas flows upward to react by gas-liquid contact. This fluctuation also causes a phenomenon in which the liquid in the reaction tower is scattered or dropped, which limits the rate of load change. It was with me. In addition, since there are two large pressure control valves 50 and 63 on the pipe from the gasification furnace 47 to the gas turbine 61, the pressure loss of the system is relatively large.
[0009]
Accordingly, the present invention has been made in view of the above, and is a fuel gasification combined power generation system capable of stably performing a desulfurization reaction in a desulfurization facility even when a load fluctuates, and a fuel gasification with low pressure loss. An object is to provide a combined power generation system.
[0010]
[Means for Solving the Problems]
In order to achieve the above object, a combined fuel gasification combined power generation system according to claim 1 includes a gasification furnace facility for generating a fuel gas with a fuel and an oxidant, and a sulfide in the fuel gas in a reaction tower. In the combined fuel gasification combined power generation system, the gasification furnace and the desulfurization facility have a desulfurization facility that removes gas and a gas turbine power generation facility that generates electric power with a generator connected to a gas turbine that uses the fuel gas as fuel And a fuel that is supplied to the gasifier according to a flow rate of the fuel gas determined from the measuring means, The supply amount of the oxidant is controlled.
[0011]
The flow meter is a means for measuring the volume flow rate of the fuel gas. Since this volume flow rate changes depending on the pressure and temperature, the volume flow rate is corrected based on the values of the thermometer and the pressure gauge, and converted into the flow rate of the fuel gas passing through the pipe per unit time. When the flow rate is large, the supply amount of the oxidant mixed with the fuel at a constant ratio is decreased. On the other hand, when the flow rate is small, the supply amount is increased. Thereby, even when the load on the generator changes, the flow rate of the fuel gas passing through the desulfurization equipment becomes constant, and the desulfurization reaction in the reaction tower can be performed stably.
[0012]
Further, the combined fuel gasification combined power generation system according to claim 2 is the combined fuel gasification combined generation system according to claim 1, wherein the desulfurization facility supplies a liquid from above to the fuel gas flowing in from below. The pump has a structure for circulating and cooling / cleaning the fuel gas, and the liquid circulation amount of the pump is controlled according to the flow rate or mass flow rate of the fuel gas.
[0013]
In the cooling / washing process accompanying the desulfurization reaction in the desulfurization facility, the flow rate of the fuel gas becomes a problem. That is, if the flow rate of the fuel gas is too high, problems such as liquid scattering during cooling and cleaning occur, which hinders stable operation in each process. On the other hand, even if the flow rate is too small, the liquid cannot be held and falls or the like, which also decreases the efficiency. In the present invention, the circulation amount of the liquid can be controlled even with respect to a transitional flow rate change that occurs when the flow rate is controlled to be constant, so that an amount of the processing liquid corresponding to the fuel gas flow rate can be circulated.
[0017]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the present invention will be described in detail with reference to the drawings. The present invention is not limited to the embodiments. The constituent elements of this embodiment include those that can be easily replaced by those skilled in the art or those that are substantially the same.
[0018]
(Embodiment 1)
1 is a configuration diagram showing a combined fuel gasification power generation system according to Embodiment 1 of the present invention. Note that the basic configuration of the combined fuel gasification combined power generation system is the same as that of the prior art, and thus the description thereof is omitted. This combined fuel gasification power generation system burns fuel 1 such as coal, heavy oil, a mixture of waste and carbide with an oxidant 2 such as air to generate combustion gas, thereby driving a gas turbine 14. This is a combined gasification power generation system.
[0019]
The fuel gas from which the unburned fuel fine powder has been removed by the dedusting device 3 of the gasification furnace facility 5 passes through the pipe 4 toward the desulfurization facility 6. The piping 4 that communicates between the gasification furnace 7 and the desulfurization facility 6 is provided with a measuring means that includes a flow meter 8, a pressure gauge 9, and a thermometer 10. These measuring means respectively measure the flow rate, pressure, and temperature of the fuel gas passing through the pipe 4. These physical quantities are converted into fuel gas flow rates by calculation (reference numeral 11).
[0020]
The flow rate of the fuel gas obtained as described above is taken into the control device 12. The control device 12 controls the supply amounts of the fuel 1 and the oxidant 2 supplied to the gasification furnace 7 according to the flow rate of the fuel gas obtained as described above. In the figure, the flow rate conversion 11 and the control device 12 are shown separately, but the arithmetic processing is possible with one control device.
[0021]
The control method will be specifically described. When the flow rate of the fuel gas is high, the supply amount of the oxidant mixed with the fuel at a constant rate is decreased, and when the flow rate is low, the supply amount is increased. When the load on the generator 13 changes, the pressure and flow rate of the fuel gas flowing through the pipe 4 also change, so that the pressure is indirectly controlled by controlling the flow rate to be constant. Considering this, it is preferable to keep the flow rate of the fuel gas within a range of at least about ± 20% of the set value.
[0022]
When it is desired to control the pressure of the gasification furnace 7 in advance control using the load signal of the generator 13 as in the prior art, the load signal from the generator 13 is sent to the control device 12 as shown by the dotted line. I'll enter it. Then, an arithmetic expression or an arithmetic table for determining the supply amounts of the fuel 1 and the oxidant 2 within a range in which the flow rate of the fuel gas flowing through the pipe 4 can be made constant may be provided in the arithmetic unit in the control device.
[0023]
By constructing the combined fuel gasification power generation system as described above, the flow rate of the fuel gas passing through the desulfurization equipment is constant even when the load on the generator changes, and there is no scattering or dropping of liquid in the reaction tower, The desulfurization reaction can be performed stably. This combined fuel gasification combined power generation system is also applicable to a so-called SOFC combined system in which a fuel cell (SOFC) using hydrogen contained in fuel gas is incorporated at point A in the figure. is there.
[0024]
(Embodiment 2)
FIG. 2 is a block diagram showing a combined fuel gasification combined power generation system according to Embodiment 2 of the present invention. The basic configuration of the combined fuel gasification combined power generation system is the same as that of the prior art and the first embodiment, and thus the description thereof is omitted. The second embodiment is characterized in that the control device 12 used in the first embodiment is used to control the pumps 23 and 24 of the cooling tower 21 and the washing tower 22 of the desulfurization facility.
[0025]
As described above, the control device 12 determines the supply amounts of the fuel 1 and the oxidant 2 to the gasification furnace 7 so as to keep the flow rate of the fuel gas flowing through the pipe 4 constant. Therefore, when partial load is applied or when the flow rate of the fuel gas is disturbed, the flow rate is controlled to be constant. However, there is some transition time until the flow rate becomes constant.
[0026]
The cooling tower 21 and the washing tower 22 have a structure for cooling and washing the fuel gas by circulating a liquid from the upper part with respect to the fuel gas flowing from the lower part by a pump. Therefore, within the transition time until the fuel gas flow rate is fixed, the circulation amount of the pumps 23 and 24 of the cooling tower 21 and the cleaning unit 22 is set according to the deviation between the set value in the control device 12 and the actual flow rate. By controlling, cooling and cleaning can be performed in accordance with fluctuations in the gas flow rate.
[0027]
That is, when the flow velocity is larger than a certain value, the circulation amount of the pumps 23 and 24 is increased so that the liquid to be circulated does not scatter. On the other hand, when the flow rate is small, the circulation amount of the pumps 23 and 24 is decreased to prevent dripping. By doing so, it is possible to circulate an amount of the processing liquid corresponding to the fuel gas flow rate. Therefore, the desulfurization reaction in the desulfurization facility can always be performed efficiently.
[0028]
(Embodiment 3)
FIG. 3 is a configuration diagram showing a combined fuel gasification power generation system according to Embodiment 3 of the present invention. Note that the basic configuration of the combined fuel gasification combined power generation system is the same as that of the prior art, and thus description thereof is omitted. The third embodiment is characterized in that the gasification furnace pressure control valve in the prior art is not used, and the supply amount control of the fuel and the like is performed by the differential pressure upstream and downstream of the valve used for controlling the pressure control valve at the gas turbine inlet. There is.
[0029]
A flow rate adjustment valve 33 provided upstream of the combustor 32 of the gas turbine 31 adjusts the flow rate of the fuel gas supplied to the combustor 32. When the load applied to the gas turbine 31 fluctuates, the control device 35 performs load follow-up control by opening and closing the flow rate adjusting valve 33 according to the load. The pressure adjustment valve 34 adjusts the fuel gas pressure upstream of the flow rate adjustment valve 33 in order to perform an appropriate flow rate adjustment in the flow rate adjustment valve 33.
[0030]
Strictly speaking, the pressure control valve 34 adjusts the differential pressure upstream and downstream thereof, and as a result, adjusts the fuel gas pressure upstream of the flow rate control valve 33. The control device 35 of the pressure control valve 34 generally performs lift control according to the deviation between the set value and the actual pressure difference. In the third embodiment, control is performed to determine the supply amounts of the fuel 1 and the oxidant 2 supplied to the gasification furnace 7 in accordance with the pressure difference upstream and downstream of the valve used for controlling the pressure control valve 34. The supply amounts of the fuel 1 and the oxidant 2 are adjusted by opening and closing valves provided in the respective supply paths.
[0031]
For example, when the load of the gas turbine 31 is increased, a pressure difference is generated between the upstream side and the downstream side of the pressure regulating valve 34. Therefore, the pressure regulating valve 34 is adjusted to keep the pressure difference constant. At the same time, the supply amounts of the fuel 1 and the oxidant 2 are increased according to the pressure difference. Thereby, the pressure of the gasifier increases, the output of the gas turbine can be increased, and the load fluctuation can be followed.
[0032]
Thus, in the combined fuel gasification power generation system according to the third embodiment, the pressure regulating valve 34 provided upstream of the gas turbine indirectly regulates the gasification furnace pressure and the fuel gas pressure passing through the desulfurization facility. To do. For this reason, a valve for adjusting the pressure other than the pressure adjusting valve 34 is not required, so that an unnecessary pressure loss is eliminated, and the overall plant efficiency can be improved.
[0033]
【The invention's effect】
As described above, according to the combined fuel gasification power generation system according to the present invention (Claim 1), the flow rate of the fuel gas entering the desulfurization facility is constant, so the gas rising speed in the reaction tower is kept constant. be able to. Thereby, even if the load of the power generation system changes greatly, the liquid surface position in the change reaction tower is stabilized, which can contribute to a highly efficient desulfurization reaction.
[0034]
Further, according to the combined fuel gasification combined power generation system according to the present invention (claim 2), in addition to the effect of the combined fuel gasification combined generation system according to claim 1, the circulation flow rate on the liquid side of the desulfurization facility is set to a flow meter or the like. It is possible to easily control the desulfurization performance by changing the flow rate or mass flow rate of the fuel gas obtained from the above.
[Brief description of the drawings]
FIG. 1 is a configuration diagram illustrating a combined fuel gasification power generation system according to a first embodiment.
FIG. 2 is a configuration diagram illustrating a combined fuel gasification power generation system according to a second embodiment.
FIG. 3 is a configuration diagram showing a combined fuel gasification power generation system according to a third embodiment;
FIG. 4 is a block diagram showing a conventional combined fuel gasification combined power generation system.
[Explanation of symbols]
1, 44 Fuel 2, 45 Oxidant 6, 42 Desulfurization equipment 7, 47 Gasification furnace 8 Flow meter 9 Pressure gauge 10 Thermometer 12, 35 Controller 13, 65 Generator 14, 61 Gas turbine 23, 24, 52, 53 Pump 34 Pressure control valve

Claims (2)

A gasifier facility for generating fuel gas with fuel and an oxidant;
A desulfurization facility for removing sulfides in the fuel gas in a reaction tower;
A gas turbine power generation facility for generating electric power with a generator connected to a gas turbine that drives the fuel gas as fuel; and
In the combined fuel gasification power generation system,
A pipe communicating between the gasification furnace and the desulfurization equipment has a measuring means including a flow meter, a thermometer, and a pressure gauge, and the gasification is performed according to the flow rate of the fuel gas obtained from the measuring means. A fuel gasification combined power generation system characterized by controlling supply amounts of the fuel and the oxidant supplied to a furnace.   The desulfurization equipment has a structure in which a liquid is circulated by a pump from above with respect to the fuel gas flowing in from the lower part, and the fuel gas is cooled and washed. Or it controls according to mass flow rate, The fuel gasification combined cycle system of Claim 1 characterized by the above-mentioned.

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