Title of the invention: Gasification gas treatment equipment and gasification gas treatment method
Technical field
[0001]
　The present disclosure relates to a gasification gas treatment facility and a gasification gas treatment method.
Background technology
[0002]
　The gasified gas obtained by gasifying fuel (coal, heavy oil, etc.) includes carbon monoxide, hydrogen, and the like. Therefore, the gasification gas can be used in a gasification gas utilization facility such as a gas turbine. However, with the gasification of fuel, the gasified gas contains components such as ammonia and hydrogen chloride. Therefore, for example, before using the gasified gas as a fuel, it is preferable to remove components such as ammonia and hydrogen chloride by a purification treatment of the gasified gas.
[0003]
　As a gasification gas refining treatment technique, the technique described in Patent Document 1 is known. Patent Document 1 describes a gasification gas processing facility for gasification gas produced by gasification of coal and containing ammonia and hydrogen chloride (see, for example, paragraph 0019). In this processing facility, purified gas is obtained by performing a treatment such as cleaning on the gasified gas (see, for example, paragraphs 0025 and 0040). The obtained purified gas is heated by the heat of the gasified gas in a heat exchanger and then supplied to a gas turbine (see, for example, paragraphs 0041 and 0051).
Prior art literature
Patent documents
[0004]
Patent Document 1: Japanese Patent No. 3764568
Outline of the invention
Problems to be solved by the invention
[0005]
　By the way, the temperature of the gasified gas fluctuates depending on the operating state of the gasification equipment. The operating state referred to here includes, for example, the type and composition of fuel, the amount of fuel supplied, and the like. Therefore, when the temperature of the gasified gas becomes lower than the planned temperature, the amount of heat obtained by the heat exchange in the heat exchanger becomes smaller, and the purified gas temperature becomes lower than the planned temperature. As a result, when the refined gas is supplied to the gas turbine, for example, the operation of the gas turbine becomes unstable due to the low temperature of the refined gas.
[0006]
　The composition of the gasified gas also varies depending on the operating state of the gasification equipment. For example, when the concentration of ammonia and the concentration of hydrogen chloride in the gasified gas are high, ammonium chloride is likely to precipitate. Therefore, it is preferable that the gasification gas is maintained at a sufficient temperature in order to suppress the precipitation of ammonium chloride. Therefore, when the gasification gas is cooled in the heat exchanger so that the temperature of the gasification gas becomes the sufficient temperature, the amount of heat supplied to the refined gas decreases, and the temperature of the refined gas decreases. As a result, for example, the operation of the gas turbine becomes unstable as in the above case.
[0007]
　The present invention has been made in view of the above problems, and the problem to be solved by the present invention is a gasification gas treatment facility capable of suppressing precipitation of ammonium chloride while sufficiently raising the temperature of the purified gas. The purpose is to provide a method for treating gasified gas.
Means to solve problems
[0008]
　(1) The gasification gas treatment facility according to at least one embodiment of the present invention is a gasification gas treatment facility
　obtained by gasifying the fuel, and is obtained by
　removing ammonia and hydrogen chloride from the gasification gas. Heat exchange is performed between the first heat exchanger for heat exchange between the obtained purified gas and the steam at the saturation temperature, the
　gasified gas, and at least the condensed water generated by the heat exchange. a second heat exchanger for performing,
　wherein between the first heat exchanger and the second heat exchanger, circulation system for circulating a circulating fluid containing at least one of said vapor or said condensed water The
　circulation system is configured to supply the circulation fluid containing at least the condensed water generated by the first heat exchanger to the second heat exchanger, and the second heat exchange. It is characterized in that the circulating fluid containing at least the steam generated in the vessel is supplied to the first heat exchanger
　.
[0009]
　According to the configuration of (1) above, the temperature of the refined gas can be raised by heating the refined gas with steam at a saturated temperature. Further, the latent heat of the steam at the saturation temperature is taken away by the heating of the refined gas, and the gasified gas can be cooled by the condensed water at the saturation temperature generated thereby. Therefore, the gasification gas can be cooled to the saturation temperature or higher, and the temperature of the gasification gas can be stably maintained at the saturation temperature or higher. As a result, the temperature of the gasified gas can be raised to the precipitation temperature of ammonium chloride or higher by adjusting the steam temperature, and the precipitation of ammonium chloride can be suppressed. Further, since the circulating fluid circulates by supplying steam from the second heat exchanger to the first heat exchanger, a new amount of steam supply can be reduced.
[0010]
　(2) In some embodiments, in the configuration of (1) above, a
　first steam system for supplying steam to the circulation system and
　a condensed water system for extracting the condensed water from the circulation system are provided. provided,
　wherein the first steam system includes a first flow control valve,
　the condensed water system includes a second flow regulating valve
　, characterized in that.
[0011]
　According to the configuration of (2) above, the amount of steam supplied and the amount of condensed water extracted can be adjusted.
[0012]
　(3) In some embodiments, in the above configuration (1) or (2),
　provided with a vapor extraction system for withdrawing vapor from the circulation system,
　the vapor withdrawal system includes a third flow control valve
　that It is characterized by.
[0013]
　According to the configuration of (3) above, when the pressure of the circulation system becomes equal to or higher than the desired pressure, the pressure of the circulation system can be reduced to the desired pressure. In addition, the extracted steam can be used in the gasification gas processing facility. In particular, by using the extracted steam, for example, the amount of air extracted from the steam turbine can be reduced, and the power generation efficiency when power is generated by the steam turbine can be improved.
[0014]
　(4) In some embodiments, in the configuration of any one of (1) to (3)
　above, steam is generated in the front stage of the second heat exchanger by heat exchange with the gasified gas. The third heat exchanger and
　the second steam system for supplying the steam generated in the third heat exchanger to the steam utilization facility are provided
　.
[0015]
　According to the configuration of (4) above, when the purified gas temperature is equal to or higher than the desired temperature and the heat is surplus, steam can be generated by utilizing the heat of the gasified gas. As a result, the generated steam can be used in the gasification gas processing facility. In particular, by using the generated steam, for example, the amount of air extracted from the steam turbine can be reduced, and the power generation efficiency when power is generated by the steam turbine can be improved.
[0016]
　(5) In some embodiments, in the configuration of (4) above, the
　steam utilization equipment is
　characterized by including the first heat exchanger .
[0017]
　According to the configuration (5) above, the amount of steam supplied from the outside to the first heat exchanger can be reduced.
[0018]
　In (6) some embodiments, in any one of the structures (1) to (5),
　the saturation temperature is a temperature 5 ° C. higher than the precipitation temperature of ammonium chloride
　, characterized in that ..
[0019]
　According to the configuration of (6) above, the precipitation of ammonium chloride can be suppressed more reliably.
[0020]
　(7) The method for treating the gasified gas according to at least one embodiment of the present invention is a method for treating
　the gasified gas obtained by gasifying the fuel, and by
　removing ammonia and hydrogen chloride from the gasified gas. A first heat exchange step in which heat is exchanged between the obtained purified gas and steam at a saturation temperature by a first heat exchanger, and between the
　gasification gas and at least the condensed water generated by the heat exchange. A second heat exchange step in which heat is exchanged by the second heat exchanger, and a
　circulating fluid containing at least the condensed water generated by the first heat exchanger are supplied to the second heat exchanger, and the second heat exchanger is supplied.
　It is characterized by including a circulation step of supplying the circulating fluid containing at least the steam generated in the heat exchanger to the first heat exchanger .
[0021]
　According to the configuration of (7) above, the temperature of the refined gas can be raised by heating the refined gas with steam at a saturated temperature. Further, the latent heat of the steam at the saturation temperature is taken away by the heating of the refined gas, and the gasified gas can be cooled by the condensed water at the saturation temperature generated thereby. Therefore, the gasification gas can be cooled to the saturation temperature or higher, and the temperature of the gasification gas can be stably maintained at the saturation temperature or higher. As a result, the temperature of the gasified gas can be raised to the precipitation temperature of ammonium chloride or higher by adjusting the steam temperature, and the precipitation of ammonium chloride can be suppressed. Further, since the circulating fluid circulates by supplying steam from the second heat exchanger to the first heat exchanger, a new amount of steam supply can be reduced.
[0022]
　(8) In some embodiments, in the method (7) above,
　the second heat exchanger is a housing having an internal space for storing the condensed water and a heat transfer tube through which the gasified gas flows. The heat transfer tube is provided so as to be exposed in the internal space, and the
　method for treating the gasified gas is
　to generate condensed water at a saturation temperature by heat exchange with steam in the first heat exchanger. and condensed water generating step,
　in the internal space of the second heat exchanger, including a storage step for storing the condensed water generated in the condensed water generating step to the reference level
　, characterized in that.
[0023]
　According to the method (8) above, the saturated water at the saturation temperature can be stored up to the reference water level in the internal space of the second heat exchanger during the start-up operation of the gasification gas treatment facility. As a result, the temperature of the second heat exchanger can be quickly raised to the saturation temperature of the condensed water, and the start-up time can be shortened.
[0024]
　(9) In some embodiments, in the method (8) above,
　a steam generation step of generating steam by a steam generation facility
　and a steam supply step of supplying the generated steam to the first heat exchanger are performed.
　It is characterized by including .
[0025]
　According to the method (9) above, the steam generated in the steam generation facility can be supplied to the first heat exchanger.
[0026]
　(10) In some embodiments, in any one of the methods (7) to (9)
　above, the circulation step flows through the circulation system so that the pressure in the circulation system becomes equal to or higher than the reference pressure.
　It is characterized by controlling the amount of circulating fluid .
[0027]
　According to the method (10) above, the pressure of the circulation system can be made higher than the reference pressure, and the saturation temperature of the circulating fluid can be raised.
The invention's effect
[0028]
　According to at least one embodiment of the present invention, it is possible to provide a gasification gas treatment facility and a gasification gas treatment method capable of suppressing the precipitation of ammonium chloride while sufficiently raising the temperature of the purified gas.
A brief description of the drawing
[0029]
FIG. 1 is a system diagram showing a gasification gas processing facility according to the first embodiment of the present invention.
FIG. 2 is a cross-sectional view of a second heat exchanger provided in the processing equipment shown in FIG.
FIG. 3 is a flowchart showing a method for treating gasified gas according to the first embodiment of the present invention.
FIG. 4 is a graph showing a change in water level in the second heat exchanger in the storage step.
FIG. 5 is a system diagram showing a gasification gas processing facility according to a second embodiment of the present invention.
Mode for carrying out the invention
[0030]
　Hereinafter, some embodiments of the present invention will be described with reference to the accompanying drawings. However, the contents described as the embodiments below or the contents described in the drawings are merely examples, and can be arbitrarily modified and implemented without departing from the gist of the present invention. In addition, each embodiment can be implemented in any combination of two or more. Further, in each embodiment, the common members are designated by the same reference numerals, and duplicate description will be omitted for simplification of description.
[0031]
　In addition, the dimensions, materials, shapes, relative arrangements, etc. of the components described as embodiments or shown in the drawings are not intended to limit the scope of the present invention to this, but are merely explanatory examples. Absent.
　For example, expressions that represent relative or absolute arrangements such as "in a certain direction", "along a certain direction", "parallel", "orthogonal", "center", "concentric" or "coaxial" are exact. Not only does it represent such an arrangement, but it also represents a state of relative displacement with tolerances or angles and distances to the extent that the same function can be obtained.
　For example, expressions such as "same", "equal", and "homogeneous" that indicate that things are in the same state not only represent exactly the same state, but also have tolerances or differences to the extent that the same function can be obtained. It shall also represent the state of existence.
　For example, the expression representing a shape such as a quadrangular shape or a cylindrical shape not only represents a shape such as a quadrangular shape or a cylindrical shape in a geometrically strict sense, but also an uneven portion or chamfering within a range where the same effect can be obtained. The shape including the part and the like shall also be represented.
　On the other hand, the expressions "equipped", "equipped", "equipped", "included", or "have" one component are not exclusive expressions that exclude the existence of other components.
[0032]
　FIG. 1 is a system diagram showing a gasification gas processing facility 1 according to the first embodiment of the present invention. The processing facility 1 is for processing the gasified gas obtained by gasifying fuels such as coal and heavy oil. Gasification of fuel is performed in a gasification facility (not shown) such as a fluidized bed furnace. The gasification gas treatment is performed by removing nitrogen and sulfur components such as carbonyl sulfide, ammonia, and hydrogen chloride in the gasification gas. By treating the gasified gas, a purified gas containing hydrogen, carbon monoxide and the like can be obtained. Then, the refined gas is supplied to a gasification gas utilization facility such as a gas turbine.
[0033]
　The processing facility 1 includes a heating facility 10 for heating the refined gas by utilizing the heat of the gasified gas, a cleaning facility 3 for cleaning the gasified gas, and a hydrogen sulfide absorption facility 4. First, the overall configuration of the gasification gas processing equipment 1 will be described focusing on the gas flow, and then the configuration of the heating equipment 10 provided in the processing equipment 1 will be described.
[0034]
　The gasified gas generated by the gasification facility (not shown) is supplied to the heat exchanger 2 through the gasification gas system 30. The heat exchanger 2 includes, for example, a gas-gas heat exchanger. The temperature of the gasified gas is, for example, about 300 ° C. to 500 ° C., and in the heat exchanger 2, the purified gas is heated to, for example, about 250 ° C. to 350 ° C. by the heat of the gasified gas. By this heating, the temperature of the gasified gas is lowered to, for example, about 200 ° C. to 300 ° C. The gasified gas after the temperature drops is supplied to a COS converter (not shown) provided in front of the second heat exchanger 12 (described later) in the gasification gas system 30. The COS transducer includes a conversion catalyst (not shown), which converts carbonyl sulfide in the gasified gas into hydrogen sulfide. The conversion to hydrogen sulfide can be performed, for example, at about 200 ° C. to 400 ° C.
[0035]
　The generated gasification gas containing hydrogen sulfide is supplied to the second heat exchanger 12 provided in the heating equipment 10 through the gasification gas system 30. In the second heat exchanger 12, heat exchange is performed between the gasified gas and the condensed water having a saturation temperature generated by the first heat exchanger 11 described later. As a result, the condensed water is heated to change its phase into steam, and the gasified gas is cooled to lower the temperature of the gasified gas. Specifically, the temperature of the gasified gas drops to the saturation temperature at the pressure of the circulation system 13. For example, if the pressure of the circulation system 13 is, for example, about 3.0 MPaG, the outlet temperature of the second heat exchanger 12 of the gasified gas is, for example, about 250 ° C. to 280 ° C. Therefore, in this case, the second heat exchanger 12 functions as a cooler for cooling the gasified gas.
[0036]
　Although details will be described later, in the first heat exchanger 11 of the heating facility 10, the purified gas is circulated by the heat of the gasified gas and the heat of the steam supplied through the first steam system 14. It is heated to the saturation temperature at a pressure of 13. In this case, the first heat exchanger 11 functions as a heater for heating the purified gas. During heating, the latent heat of the steam is deprived, so that at least a part of the steam is condensed to generate condensed water at a saturated temperature. Then, the saturated water having a saturated temperature generated by the first heat exchanger 11 is supplied to the second heat exchanger 12 as described above.
[0037]
　The gasified gas after heat exchange in the second heat exchanger 12 is supplied to the cleaning facility 3 through the gasification gas system 30. The cleaning facility 3 is configured to include, for example, a scrubber, and by bringing the cleaning water into contact with the gasified gas, ammonia and hydrogen chloride in the gasified gas are removed. In addition, a part of hydrogen sulfide in the gasified gas is also dissolved in the washing water. The removed ammonia and hydrogen chloride are dissolved in washing water, and the dissolved ammonia, hydrogen chloride and hydrogen sulfide are treated in a treatment apparatus (not shown).
[0038]
　The gasified gas after removing ammonia and the like is cooled to, for example, about 40 ° C., and then supplied to the hydrogen sulfide absorption facility 4 through the gasification gas system 31. The hydrogen sulfide absorption facility 4 is configured to include, for example, a tower, and hydrogen sulfide in the gasification gas is removed by bringing the amine aqueous solution into contact with the gasification gas.
[0039]
　The refined gas, which is a gasified gas after removing hydrogen sulfide, is supplied to the first heat exchanger 11 provided in the heating facility 10 through the refined gas system 32. Then, in the heating facility 10, the refined gas is heated to, for example, about 250 ° C. by the heat of the gasification gas as described above and the heat of the steam supplied through the first steam system 14 (described later). Will be done. The purified gas after heating is supplied to the heat exchanger 2 through the refined gas system 32, and is heated to, for example, about 250 ° C. to 350 ° C. by the heat of the gasified gas as described above. Then, the refined gas after heating is supplied to gas utilization equipment (not shown) such as a gas turbine.
[0040]
　The heating equipment 10 for heating the refined gas in the processing equipment 1 includes a first heat exchanger 11, a second heat exchanger 12, and a circulation system 13. In the following description, the equipment and the system provided in the heating equipment 10 are all the equipment and the system provided in the processing equipment 1.
[0041]
　The first heat exchanger 11 is a purified gas obtained by removing at least ammonia and hydrogen chloride (in addition to these, for example, hydrogen sulfide is also removed in one embodiment of the present invention) from the gasified gas, and the saturation temperature. It is for exchanging heat with steam. Specifically, the purified gas is heated by steam at a saturation temperature. By depriving the latent heat of steam by heating the refined gas, the steam condenses and condensed water is generated. The saturation temperature referred to here is, for example, a temperature 5 ° C. or higher higher than the precipitation temperature of ammonium chloride, preferably 10 ° C. or higher, and more preferably 20 ° C. or higher. By setting the saturation temperature to such a temperature, the precipitation of ammonium chloride can be suppressed more reliably.
[0042]
　Further, the second heat exchanger 12 is for performing heat exchange between the gasified gas and at least the condensed water generated by the heat exchange. Specifically, the heat of the gasified gas heats the condensed water at a saturated temperature. As a result, the condensed water at the saturation temperature undergoes a phase change, and steam at the saturation temperature is generated.
[0043]
　The first heat exchanger 11 includes, for example, a gas-gas heat exchanger. Further, the second heat exchanger 12 includes, for example, a so-called kettle type heat exchanger. The structure of the second heat exchanger 12 will be described with reference to FIG.
[0044]
　FIG. 2 is a cross-sectional view of the second heat exchanger 12 provided in the processing equipment 1 shown in FIG. The structure of the second heat exchanger 12 is not limited to the illustrated example, and the structure can be arbitrarily changed, for example, the position of the introduction port 141 is turned upside down.
[0045]
　The second heat exchanger 12 has a housing 121 having an internal space 121A for storing condensed water generated by the first heat exchanger 11 and flowing through the circulation system 13 (described later), and a transmission through which gasification gas flows. A heat transfer tube 122, which is a heat tube 122 and is arranged so as to be exposed to the internal space 121A, is provided. Of these, the housing 121 has a shape in which the lower surface extends in the horizontal direction and a part of the upper surface bulges upward.
[0046]
　The upper surface of the housing 121 is provided with a discharge port 142 for discharging steam and an introduction port 146 for introducing gasification gas for heat exchange. Further, on the lower surface of the housing 121, an introduction port 141 for introducing make-up water, condensed water, and steam into the internal space 121A, a discharge port 143 for discharging from the internal space 121A, and gasification after heat exchange. A discharge port 145 for discharging gas is provided. Of these, the circulation system 13 (see FIG. 1) is configured by including the introduction port 141, the discharge port 142, and the internal space 121A. Further, a condensed water system 15 (see FIG. 1) is connected to the discharge port 143. Further, the gasification gas system 30 is configured by including the introduction port 146, the space 151, the heat transfer tube 122, the space 150, and the discharge port 145.
[0047]
　The second heat exchanger 12 includes a water level sensor 36 for measuring the water level of the condensed water L accumulated in the internal space 121A. Then, during the normal operation of the treatment facility 1 (that is, during the normal operation of the heating facility 10), when the water level measured by the water level sensor 36 is lower than the reference water level, the make-up water is set so that the water level becomes the reference water level. The flow control valve 34 provided in the system 33 is opened to supply make-up water. The supply amount of make-up water is controlled by feedback control based on the flow rate measured by the flow meter 35. When the water level measured by the water level sensor 36 becomes higher than the reference water level, the condensed water L is extracted through a discharge system (not shown) so that the water level becomes the reference water level.
[0048]
　The reference water level is set at a position where the entire heat transfer tube 122 is immersed. Therefore, the gasified gas introduced into the space 151 through the introduction port 146 exchanges heat with the condensed water L at the saturation temperature when flowing through the heat transfer tube 122. Then, the gasified gas after heat exchange is discharged to the outside of the second heat exchanger 12 through the space 150 and the discharge port 145.
[0049]
　Returning to FIG. 1, the circulation system 13 is for circulating a circulating fluid containing at least one of steam and condensed water between the first heat exchanger 11 and the second heat exchanger 12. That is, the circulation system 13 is configured to supply the second heat exchanger 12 with a circulating fluid containing at least the condensed water generated by the first heat exchanger 11. Further, the circulation system 13 is configured to supply the first heat exchanger 11 with a circulating fluid containing at least the vapor generated by the second heat exchanger 12.
[0050]
　Further, the circulating fluid circulating in the circulation system 13 has a saturation temperature at the pressure of the circulation system 13. Further, the circulation system 13 is configured so that the pressure in the system becomes constant (for example, about 3.0 MPaG) by supplying steam to the circulation system 13 and discharging steam from the circulation system 13.
[0051]
　By providing the first heat exchanger 11, the second heat exchanger 12, and the circulation system 13, it is possible to raise the temperature of the refined gas by heating the refined gas with steam at a saturation temperature. Further, the latent heat of the steam at the saturation temperature is taken away by the heating of the refined gas, and the gasified gas can be cooled by the condensed water at the saturation temperature generated thereby. Therefore, the gasification gas can be cooled to the saturation temperature or higher, and the temperature of the gasification gas can be stably maintained at the saturation temperature or higher. As a result, the temperature of the gasified gas can be raised to the precipitation temperature of ammonium chloride or higher by adjusting the steam temperature, and the precipitation of ammonium chloride can be suppressed. Further, since the circulating fluid circulates by supplying steam from the second heat exchanger to the first heat exchanger, a new amount of steam supply can be reduced.
[0052]
　Further, the heating facility 10 includes a first steam system 14 for supplying steam to the circulation system 13 and a condensed water system 15 for extracting condensed water as blowdown water from the circulation system 13. Of these, the condensed water system 15 is connected to the discharge port 143 (see FIG. 2) of the second heat exchanger 12. As a result, the condensed water flowing through the circulation system 13 is extracted to the outside through the second heat exchanger 12 and the discharge port 143.
[0053]
　Further, the first steam system 14 includes a first flow rate adjusting valve 18, and the condensed water system 15 includes a second flow rate adjusting valve 17. By providing the first flow rate adjusting valve 18 and the second flow rate adjusting valve 17, the amount of steam supplied and the amount of condensed water extracted can be adjusted.
[0054]
　The steam supply to the circulation system 13 through the first steam system 14 is controlled so that the flow rate measured by the flow meter 20 becomes constant. The steam supply amount control is performed by controlling the opening degree of the first flow rate adjusting valve 18. Further, the drainage of condensed water from the circulation system 13 is also controlled so that the flow rate measured by the flow meter 19 becomes constant. The amount of condensed water drawn out is controlled by controlling the opening degree of the second flow rate adjusting valve 17.
[0055]
　Further, the heating facility 10 includes a steam extraction system 21 for extracting steam from the circulation system 13, and the steam extraction system 21 includes a third flow rate adjusting valve 22. Further, the heating equipment 10 includes a pressure gauge 23 for measuring the pressure of the circulation system 13. Then, the pressure of the circulation system 13 is controlled to be constant so that the pressure of the circulation system 13 measured by the pressure gauge 23 becomes constant.
[0056]
　By providing the steam extraction system 21 and the third flow rate adjusting valve 22, the pressure of the circulation system 13 can be reduced to a desired pressure when the pressure of the circulation system 13 becomes equal to or higher than the desired pressure. Further, the extracted steam can be used in the gasification gas processing facility 1. In particular, by using the extracted steam, for example, the amount of air extracted from the steam turbine can be reduced, and the power generation efficiency when power is generated by the steam turbine can be improved. When the pressure in the circulation system 13 drops, control is performed to increase the amount of steam supplied through the first steam system 14.
[0057]
　The processing equipment 1 including the heating equipment 10 is controlled by an arithmetic control device (not shown). Although not shown, the arithmetic and control devices include a CPU (Central Processing Unit), a RAM (Random Access Memory), a ROM (Read Only Memory), an HDD (Hard Disk Drive), an I / F (InterFace), a control circuit, and the like. It is realized by executing a predetermined control program stored in the ROM by the CPU.
[0058]
　FIG. 3 is a flowchart showing a method for treating gasified gas according to the first embodiment of the present invention. Hereinafter, the method for treating the gasified gas according to the first embodiment of the present invention is simply referred to as "the treatment method for the first embodiment". The processing method of the first embodiment can be performed using, for example, the processing equipment shown in FIG. Therefore, in the following description, FIGS. 1 and 2 will be referred to as appropriate.
[0059]
　The treatment method of the first embodiment is a treatment method of gasified gas obtained by gasification of fuel. The processing method of the first embodiment is circulation of steam generation step S1, steam supply step S2, condensed water generation step S3, storage step S4, first heat exchange step S5, second heat exchange step S6, and circulation. Including step S7. Of these, the steam generation step S1, the steam supply step S2, the condensed water generation step S3, and the storage step S4 are performed during the start-up operation of the treatment equipment 1. Further, the first heat exchange step S5, the second heat exchange step S6, and the circulation step S7 are performed during the normal operation of the processing equipment 1.
[0060]
　Here, the normal operation and the start-up operation will be described.
　The processing facility 1 (see FIG. 1) is installed, for example, as part of an integrated coal gasification combined cycle (IGCC). Then, the gasification gas generated in the gasification furnace (gasification equipment) constituting the IGCC is subjected to the above-mentioned purification treatment to obtain a refined gas. The obtained refined gas is supplied to a gas turbine (gasification gas utilization facility) that also constitutes the IGCC to generate electricity. In addition, the exhaust heat from the gas turbine is recovered by the exhaust heat recovery boiler, and steam is generated. The generated steam is supplied to the steam turbine to generate electricity. The state in which the gas turbine and the steam turbine are constantly generating electricity corresponds to the normal operation in the present specification. Therefore, during normal operation, the gasification gas produced in the gasification furnace is refined in the above processing facility 1.
[0061]
　On the other hand, in order to perform the normal operation from the state where the operation has been stopped due to maintenance or the like, the IGCC including the processing facility 1 is started and operated. Specifically, as the start-up operation, first, in each component equipment of IGCC other than the processing equipment 1 (for example, a gasifier, a gas turbine, a steam turbine, etc., hereinafter referred to as a "main engine" (not shown)), pre-operation preparations (various types) (Start of power supply to equipment, etc.) is performed. Further, in the processing equipment 1, for example, pre-operation preparation of various equipment (start of circulation of circulating fluid by injecting steam into the circulation system 13, start of power supply to various equipment, etc.) is performed. As a result, in the circulation system 13, circulation of the circulating fluid (including at least one of steam and condensed water) at a saturated temperature is started.
[0062]
　Next, in the main engine, the steam turbine is started and the gas turbine is ignited. On the other hand, in the processing equipment 1, the gasification gas systems 30 and 31 and the refined gas system 32 are pressurized by supplying pressurized air using a compressor (not shown). After that, the gasifier included in the main engine is ignited. The fuel used for ignition in the gasifier is an auxiliary fuel such as kerosene or light oil at the time of start-up. Combustion of auxiliary fuel in a gasification furnace produces gas refined gas at a relatively low temperature (for example, about 100 ° C.). Then, by flowing the purified gas refined gas through the gasification gas system 30, 31 and the refined gas system 32, the temperatures of the gasification gas system 30, 31 and the refined gas system 32 rise.
[0063]
　However, the temperature of the gas refining gas is relatively low as described above. Therefore, in this case, the second heat exchanger 12 functions as a heater for heating the gas purification gas. Therefore, when heat exchange is performed between the circulation system 13 through which the circulating fluid at the saturation temperature flows and each of the first heat exchanger 11 and the second heat exchanger 12, the vapors supplied to the circulation system 13 are respectively. It changes to condensed water in the heat exchanger of. Then, the condensed water generated by the first heat exchanger 11 and the second heat exchanger 12 collects in the internal space 121A of the second heat exchanger 12 described with reference to FIG. 2 above (details of this point are described). It will be described later with reference to FIG. 4).
[0064]
　Further, in the first heat exchanger 11, the gas purification through gas is heated by the circulating fluid containing the steam supplied through the first steam system 14. Therefore, the gas purification gas temperature supplied to the gasification gas utilization facility (for example, a gas turbine) through the refined gas system 32 can be rapidly raised. As a result, the startup time can be shortened.
[0065]
　When the temperature of the gas refining gas is sufficiently raised by heating in the first heat exchanger 11, the fuel to be burned in the gasifier is changed to coal. As a result, in the gasification furnace, the combustion of coal begins to generate gasified gas (for example, about 300 ° C. to 500 ° C. as described above) higher than the temperature of the gas refining gas. The generated gasification gas begins to flow through the gasification gas systems 30, 31 and the refined gas system 32, and the temperatures of the gasification gas systems 30, 31 and the refined gas system 32 further rise. Then, the load is increased by increasing the amount of coal to be burned, and the start-up operation is completed when the desired load is reached. After the start-up operation is completed, the above-mentioned normal operation is performed.
[0066]
　In the processing method of the first embodiment shown in FIG. 3 of steam, the steam generation step S1 is a step of generating steam by a steam generation facility (not shown) such as an auxiliary boiler. Further, the steam supply step S2 is a step of supplying the generated steam to the first heat exchanger 11. By passing through the steam generation step S1 and the steam supply step S2, the steam generated in the steam generation facility such as an auxiliary boiler can be supplied to the first heat exchanger 11.
[0067]
　In the condensed water generation step S3, condensed water having a saturation temperature is generated by heat exchange with steam in the first heat exchanger 11. The saturation temperature referred to here is synonymous with the saturation temperature described with reference to FIG. 1 above. Further, in the storage step S4, the condensed water generated in the condensed water generation step S3 is stored up to the reference water level in the internal space 121A (see FIG. 2) of the second heat exchanger 12. The condensed water generated in the condensed water generation step S3 is introduced into the internal space 121A from the introduction port 141 (see FIG. 2) of the housing 121 through the circulation system 13. The storage step S4 will be described with reference to FIG.
[0068]
　FIG. 4 is a graph showing a change in the water level in the second heat exchanger 12 in the storage step S4. However, this graph is a schematic one, and the actual water level does not always match the shape of this graph.
[0069]
　In the storage step S4, condensed water having a saturation temperature is accumulated in the internal space 121A of the second heat exchanger 12 by heat exchange with the steam in the first heat exchanger 11. As described above, since the condensed water is also generated in the second heat exchanger 12, the condensed water generated in the second heat exchanger 12 is also collected in the internal space 121A. Therefore, during the start-up operation, at least the condensed water generated by the first heat exchanger 11 accumulates, so that the water level in the internal space 121A (measured by the water level sensor 36 described above) rises.
[0070]
　Then, after the start-up operation is completed, during the normal operation, a certain amount of steam is supplied to the circulation system 13 and a certain amount of condensed water is extracted from the internal space 121A as described above. As a result, the normal operation is performed so that the water level in the internal space 121A becomes constant at the reference water level.
[0071]
　By going through the condensed water generation step S3 and the storage step S4, the saturated water at the saturation temperature can be stored up to the reference water level in the internal space 121A of the second heat exchanger 12 at the time of starting operation of the gasification gas treatment facility. it can. As a result, the temperature of the second heat exchanger 12 can be quickly raised to the saturation temperature of the condensed water, and the start-up time can be shortened. During the start-up operation, the second heat exchanger 12 functions as a heater for heating the gasified gas.
[0072]
　Returning to FIG. 3, the first heat exchange step S5 is a purified gas obtained by removing at least ammonia and hydrogen chloride (in addition to these, hydrogen sulfide is also removed in one embodiment of the present invention) from the gasified gas. The heat is exchanged between the gas and the steam at the saturation temperature by the first heat exchanger 11. Further, in the second heat exchange step S6, heat exchange is performed between the gasified gas and at least the condensed water generated by the heat exchange in the first heat exchange step S5 by the second heat exchanger 12. .. Further, in the circulation step S7, the circulating fluid containing at least the condensed water generated by the first heat exchanger 11 is supplied to the second heat exchanger 12, and the circulating fluid containing at least the steam generated by the second heat exchanger 12 is supplied. Is supplied to the first heat exchanger 11. The supply of the circulating fluid to the first heat exchanger 11 is performed through the circulation system 13.
[0073]
　By passing through the first heat exchange step S5, the second heat exchange step S6, and the circulation step S7, the temperature of the refined gas can be increased by heating the refined gas with steam at a saturation temperature. Further, the latent heat of the steam at the saturation temperature is taken away by the heating of the refined gas, and the gasified gas can be cooled by the condensed water at the saturation temperature generated thereby. Therefore, the gasification gas can be cooled to the saturation temperature or higher, and the temperature of the gasification gas can be stably maintained at the saturation temperature or higher. As a result, the temperature of the gasified gas can be raised to the precipitation temperature of ammonium chloride or higher by adjusting the steam temperature, and the precipitation of ammonium chloride can be suppressed. Further, since the circulating fluid circulates by supplying steam from the second heat exchanger to the first heat exchanger, a new amount of steam supply can be reduced.
[0074]
　Further, in the treatment method of the first embodiment, in the circulation step S7, the amount of the circulating fluid (at least one of steam or condensed water) flowing through the circulation system 13 is adjusted so that the pressure of the circulation system 13 becomes equal to or higher than the reference pressure. Control. As a result, the pressure of the circulation system 13 can be made higher than the reference pressure, and the saturation temperature of the circulating fluid can be raised.
[0075]
　FIG. 5 is a system diagram showing the gasification gas processing facility 1A according to the second embodiment of the present invention. The processing equipment 1A includes a heating equipment 10A, similarly to the processing equipment 1 described above. However, in the processing facility 1A, in addition to the configuration of the heating facility 10 described above, a third heat exchanger 51 for generating steam by heat exchange with the gasified gas is provided in front of the second heat exchanger 12. A second steam system 62 for supplying steam generated in the third heat exchanger 51 to steam utilization equipment (first heat exchanger 11 and steam turbine (not shown)) is provided.
[0076]
　The required value of the refined gas temperature supplied to the gasification gas utilization equipment such as a gas turbine may be lower than usual. In this case, the temperature of the refined gas supplied to the gasification gas utilization facility satisfies the required value, and the heat of the gasification gas becomes surplus. Therefore, the heat of the gasification gas can be used for purposes other than heating the refined gas. Therefore, in such a case, the heat of the gasification gas is recovered in the third heat exchanger 51, and steam is generated by the recovered heat.
[0077]
　The third heat exchanger 51 is configured to include a so-called kettle-type heat exchanger, similarly to the second heat exchanger 12 described above (see FIG. 2). Therefore, the third heat exchanger 51 includes a make-up water system 61 for supplying make-up water to the internal space (not shown) of the housing constituting the third heat exchanger 51, and the third heat exchanger 51. A condensed water system 64 for extracting the accumulated condensed water is connected. The supply of make-up water by the make-up water system 61 is performed by opening the flow rate adjusting valve 53 provided in the make-up water system 61. The supply amount control of the make-up water is performed by feedback control based on the flow rate measured by the flow meter 54. Further, the extraction of the condensed water by the condensed water system 64 is controlled so that the flow rate measured by the flow meter 56 becomes constant. The amount of condensed water drawn out is controlled by controlling the opening degree of the fourth flow rate adjusting valve 55.
[0078]
　Further, the third heat exchanger 51 includes a water level sensor 57 for measuring the water level of the condensed water accumulated in the internal space. Then, during the normal operation of the treatment facility 1A (that is, during the normal operation of the heating facility 10A), when the water level measured by the water level sensor 57 is lower than the reference water level, the water level becomes the reference water level. In this way, make-up water is supplied. When the water level measured by the water level sensor 57 becomes higher than the reference water level, the condensed water is extracted through a discharge system (not shown) so that the water level becomes the reference water level.
[0079]
　By providing the third heat exchanger 51 and the second steam system 62, when the purified gas temperature is higher than the desired temperature and the heat is surplus, steam is generated by utilizing the heat of the gasification gas. it can. As a result, the generated steam can be used in the gasification gas processing facility 1. In particular, by using the generated steam, for example, the amount of air extracted from the steam turbine can be reduced, and the power generation efficiency when power is generated by the steam turbine can be improved.
[0080]
　The steam utilization equipment to which the steam generated by the third heat exchanger 51 is supplied includes the first heat exchanger 11 in addition to the processing equipment 1. Therefore, the steam generated by the third heat exchanger 51 is supplied to each facility in the plant (not shown) through the steam extraction system 21, and also enters the circulation system 13 through the second steam system 62 to enter the first heat exchanger. It is supplied to 11. By supplying the steam generated by the third heat exchanger 51 to the first heat exchanger 11, the amount of steam supplied from the outside to the first heat exchanger 11 can be reduced.
[0081]
　Further, the steam generated by the third heat exchanger 51 is also used for heating the make-up water supplied to the third heat exchanger 51. Specifically, it branches from the second steam system 62 and is connected to the third steam system 63. The third steam system 63 is provided with a water supply heater 52. In the water supply heater 52, the make-up water is heated by the heat of the steam. On the other hand, the steam that has been deprived of heat becomes condensed water as the temperature drops and is discharged to the outside. Then, the heated make-up water is supplied to the third heat exchanger 51 through the make-up water system 61, and the water level in the third heat exchanger 51 is restored.
[0082]
　Similarly to the above-mentioned processing equipment 1, the processing equipment 1A having the above configuration can suppress the precipitation of ammonium chloride while sufficiently raising the temperature of the purified gas.
Description of the sign
[0083]
1,1A Treatment equipment
2 Heat exchanger
3 Cleaning equipment
4 Hydrogen sulfide absorption equipment
10, 10A Heating equipment
11 1st heat exchanger
12 2nd heat exchanger
13 Circulation system
14 1st steam system
15, 64 Condensed water system
17th 2 Flow control valve
18 1st flow control valve
19, 20, 35, 54, 56 Flow meter
21 Steam extraction system
22 3rd flow control valve
23 Pressure gauge
30, 31 Gasification gas system
32 Purified gas system
33, 61 Makeup water System
34, 53 Flow control valve
36, 57 Water level sensor
51 Third heat exchanger
52 Water supply heater
55 Fourth flow control valve
62 Second steam system
63 Third steam system
121 Housing
121A Internal space
122 Heat transfer tube
141,146 Inlet port
142,143,145 Outlet port
150,151 Space
L Condensed water
S1 Steam generation step
S2 Steam supply step
S3 Condensed water generation step
S4 Storage step
S5 First heat exchange step
S6 Second heat exchange step
S7 Circulation step
The scope of the claims
[Claim 1]
　A facility for treating gasified gas obtained by gasifying fuel, in
　order to exchange heat between the purified gas obtained by removing at least ammonia and hydrogen chloride from the gasified gas and steam at a saturation temperature. The first heat exchanger
　, the second heat exchanger for exchanging heat between the gasified gas and at least the condensed water generated by the heat exchange,
　the first heat exchanger and the first heat exchanger. A circulation system for circulating a circulating fluid containing at least one of the steam or the condensed water is provided between the two heat exchangers, and the
　circulation system is generated by the first heat exchanger. The circulating fluid containing at least the condensed water is supplied to the second heat exchanger, and the circulating fluid containing at least the steam generated by the second heat exchanger is supplied to the first heat exchanger. A
　gasification gas treatment facility characterized by being configured to supply .
[Claim 2]
　Wherein a first steam line for supplying steam to the circulation system,
　and a condensed water line for withdrawing the condensed water from the circulation system,
　the first steam system includes a first flow control valve,
　the condenser
　The gasification gas treatment facility according to claim 1, wherein the water system includes a second flow rate regulating valve .
[Claim 3]
　The gasification gas processing equipment according to claim 1 or 2 　, further
　comprising a steam extraction system for extracting steam from the circulation system, and the steam extraction system includes a third flow rate adjusting valve
.
[Claim 4]
　In
　order to supply the third heat exchanger for generating steam by heat exchange with the gasified gas and the steam generated in the third heat exchanger to the steam utilization facility in front of the second heat exchanger. The
　gasification gas treatment facility according to any one of claims 1 to 3, further comprising a second steam system according to the above.
[Claim 5]

　The gasification gas processing equipment according to claim 4, 　wherein the steam utilization equipment includes the first heat exchanger .
[Claim 6]

　The gasification gas treatment facility according to any one of claims 1 to 5, 　wherein the saturation temperature is 5 ° C. or higher higher than the precipitation temperature of ammonium chloride .
[Claim 7]
　A
　first heat exchanger between the purified gas obtained by removing at least ammonia and hydrogen chloride from the gasified gas and the steam at the saturation temperature , which is a method for treating the gasified gas obtained by gasifying the fuel . a first heat exchange step of performing heat exchange with,
　and the gasification gas, at least a second heat exchange step of performing heat exchange by the second heat exchanger with the condensed water generated by the heat exchange,
　the The circulating fluid containing at least the condensed water generated by the first heat exchanger is supplied to the second heat exchanger, and the circulating fluid containing at least the steam generated by the second heat exchanger is supplied to the first heat exchanger. A
　method of treating gasified gas , which comprises a circulation step of supplying to a vessel .
[Claim 8]
　The second heat exchanger includes a housing having an internal space for storing the condensed water, and a heat transfer tube through which the gasified gas flows and is arranged so as to be exposed in the internal space. The
　method for treating the gasified gas includes
　a condensed water generation step of generating condensed water at a saturation temperature by heat exchange with steam in the first heat exchanger, and the
　internal space of the second heat exchanger. The
　method for treating a gasified gas according to claim 7, further comprising a storage step of accumulating the condensed water generated in the condensed water generation step to a reference water level .
[Claim 9]
　The gasification gas treatment according to claim 8, further
　comprising 　a steam generation step of generating steam by a steam generation facility and a steam supply step of supplying the generated steam to the first heat exchanger.
Method.
[Claim 10]
　The circulation step according
　to any one of claims 7 to 9, wherein the circulation step controls the amount of the circulating fluid flowing through the circulation system so that the pressure of the circulation system becomes equal to or higher than the reference pressure . Gasification gas treatment method.