Steam generation system for CO2 recovery device, CO2 recovery device equipped with the same, and steam generation method for CO2 recovery device

Abstract

Provided is a steam generation system for a CO₂ recovery device that can supply thermal energy to the CO₂ recovery device using heat below 100°C. 【Solution means】The steam generation system 9 includes a steam generator 27 that heats negative-pressure water with warm water below 100°C to generate negative-pressure steam, a steam supply line 31 that supplies the negative-pressure steam generated by the steam generator 27 to the CO₂ recovery device 7, a water supply line 29 that supplies water to the steam generator 27, and a pressure reducing valve 35 provided in the water supply line 29 that reduces the pressure of the water supply to below atmospheric pressure.

Description

Technical Field

[0001] The present disclosure relates to a steam generation system for a CO2 recovery device, a CO2 recovery device including the same, and a method for generating steam for a CO2 recovery device.

Background Art

[0002] A CO2 recovery device that recovers CO2 from exhaust gas discharged from an internal combustion engine is known (see, for example, Patent Document 1). The CO2 recovery device described in Patent Document 1 uses a part of the exhaust gas as a heat source for desorbing CO2 adsorbed on the adsorbent.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, exhaust gas often reaches a high temperature such as 300°C to 400°C. If a part of the exhaust gas is used as a heat source for desorbing CO2 as in the CO2 recovery device described in Cited Document 1, the amount of exhaust gas that can be used for high-temperature applications such as waste heat recovery boilers will relatively decrease.

[0005] Since steam is often used as a heat source for CO2 recovery devices, it is advantageous to generate steam and supply it to the CO2 recovery device. On the other hand, although there is heat below 100°C around the CO2 recovery device, it is discarded without being utilized, and there is a problem that the effective utilization of thermal energy is not achieved.

[0006] The present disclosure has been made in view of such circumstances, and an object thereof is to provide a steam generation system for a CO2 recovery device that can supply thermal energy to the CO2 recovery device using heat below 100°C, a CO2 recovery device including the same, and a steam generation method for a CO2 recovery device.

Means for Solving the Problems

[0007] A steam generation system for a CO2 recovery device according to an aspect of the present disclosure includes a steam generator that heats negative pressure water with a heat medium to generate steam, and a steam supply unit that supplies the steam generated by the steam generator to the CO2 recovery device. The heat medium is cooling water of a CO2 generation source recovered by the CO2 recovery device or a heat medium heated by the cooling water.

[0008] A CO2 recovery device according to an aspect of the present disclosure includes the above-described steam generation system for a CO2 recovery device.

[0009] A steam generation method for a CO2 recovery device according to an aspect of the present disclosure includes a steam generation step of heating negative pressure water with a heat medium to generate steam, and a steam supply step of supplying the steam generated in the steam generation step to the CO2 recovery device. The heat medium is cooling water of a CO2 generation source recovered by the CO2 recovery device or a heat medium heated by the cooling water.

Effects of the Invention

[0010] Thermal energy can be supplied to the CO2 recovery device using heat below 100°C.

Brief Description of the Drawings

[0011]

Figure 1

Figure 2

Figure 3

Mode for Carrying Out the Invention

[0012] [First Embodiment] Hereinafter, the first embodiment according to the present disclosure will be described with reference to FIG. 1. FIG. 1 shows a cogeneration system 1A according to the present embodiment. The cogeneration system 1A includes a gas engine (power generation engine) 3, an exhaust gas boiler (waste heat recovery boiler) 5, a CO2 recovery device 7, and a steam generator (steam generation system for CO2 recovery device) 9.

[0013] The gas engine 3 is operated using a gas fuel such as city gas as fuel. A generator (not shown) is driven by the gas engine 3 to generate electric power. The electric power generated by the generator is supplied to the demand destination. Instead of the gas engine 3, other power generation engines (internal combustion engines) such as a gas turbine engine or a diesel engine using oil fuel may be used. Also, a plurality of gas engines 3 may be provided.

[0014] The exhaust gas boiler 5 generates steam by the exhaust gas discharged from the gas engine 3. The exhaust gas that has completed heat exchange in the exhaust gas boiler 5 is led to the CO2 recovery device 7 through the exhaust gas flow path 11. The steam generated in the exhaust gas boiler 5 is led to the boiler steam supply path 13 and supplied to an external demand destination.

[0015] The CO2 recovery device 7 recovers CO2 (carbon dioxide) from the exhaust gas led from the gas engine 3. The CO2 recovery device 7 employs a chemical absorption method using an absorption liquid that chemically absorbs CO2, such as an amine absorption liquid (adsorbent).

[0016] The CO₂ recovery device 7 includes an absorption tower 15 and a regeneration tower 16. In the absorption tower 15, an amine absorption liquid is brought into contact with the exhaust gas to absorb CO₂ in the exhaust gas. A lean solution supply section 15a that supplies a lean solution from which CO₂ has been desorbed and the CO₂ concentration has been made lean is connected to the absorption tower 15. While the amine absorption liquid (lean solution) supplied from the lean solution supply section 15a flows through the absorption tower 15, it absorbs CO₂ in the exhaust gas. The rich solution that has absorbed CO₂ in the absorption tower 15 and has a rich CO₂ concentration is sent by an absorption tower pump 22 to a rich solution supply section 16a via a heat exchanger 20.

[0017] The heat exchanger 20 is a non-contact type heat exchanger and exchanges heat between the lean solution supplied from a regeneration tower pump 18 and the rich solution supplied from an absorption tower pump 22.

[0018] The exhaust gas from which CO₂ has been removed by the amine absorption liquid is discharged from the absorption tower 15 to the outside.

[0019] In the regeneration tower 16, CO₂ is desorbed from the rich solution that has absorbed CO₂. The amine absorption liquid (rich solution) supplied into the regeneration tower 16 from the rich solution supply section 16a is heated by the heat exchanger 20, thereby being given the amount of heat required for the endothermic reaction of desorbing CO₂. While the amine absorption liquid (rich solution) supplied from the rich solution supply section 16a flows through the regeneration tower 16, CO₂ is desorbed from the rich solution. The CO₂ desorbed from the rich solution is discharged from the regeneration tower 16 and led to a CO₂ storage section (not shown).

[0020] The regeneration tower 16 is connected to a reboiler 17 that heats the amine absorption liquid. The reboiler 17 heats the amine absorption liquid taken out from the regeneration tower 16 via the absorption liquid recovery path 16b. As the heating source of the reboiler 17, the steam led from a boiler steam branch path (steam supply section) 13a branched from the boiler steam supply path 13 is used. The amine absorption liquid heated by the reboiler 17 is returned to the regeneration tower 16 via the absorption liquid return path 16c. The heated amine absorption liquid (lean solution) is taken out from the bottom of the regeneration tower 16 and sent to the heat exchanger 20 by the regeneration tower pump 18.

[0021] The steam generation system 9 is connected to the gas engine 3. The steam generation system 9 includes a hot water circuit 25 in which hot water (heat medium) circulates between the gas engine 3, and a steam generator 27 to which the hot water circuit 25 is connected.

[0022] In the present embodiment, this heat medium is the cooling water that cools the gas engine 3, which is the source of CO2 recovered by the CO2 recovery device 7, or the heat medium heated by the cooling water. More specifically, for example, it is configured as follows. The hot water circuit 25 is a closed-loop flow path for circulating the hot water led from the gas engine 3. The hot water is heated by exchanging heat with the cooling water that cools the gas engine 3, and is set to a temperature of less than 100°C, for example. A hot water pump 33 is provided in the hot water circuit 25. The operation of the hot water pump 33 is controlled by a control unit (not shown). Note that the cooling water that cools the gas engine 3 may be directly supplied to the hot water circuit 25, or the hot water circuit 25 may be constituted by the circulation path itself of the cooling water. Here, the cooling water that cools the gas engine 3 includes the cooling water that cools the oil circulating inside or passing through the gas engine 3. Note that as a configuration in which the cooling water that cools the gas engine 3 heats the hot water circuit 25, the cooling water may be drawn out to the outside of the gas engine 3 by a water supply pipe, and the hot water inside the hot water circuit 25 is heated by a heat exchanger provided outside the gas engine 3.

[0023] The steam generator 27 is a non-contact heat exchanger in which hot water and feed water exchange heat without contact, and for example, a partition heat exchanger such as a plate heat exchanger, a shell & plate heat exchanger, or a shell & tube heat exchanger can be used.

[0024] A water supply passage (water supply section) 29 for supplying feed water to be heated is connected to the steam generator 27. A pressure reducing valve 35 is provided in the water supply passage 29. The pressure reducing valve 35 reduces the pressure of the feed water at normal temperature (for example, 20°C) and atmospheric pressure to negative pressure water. The opening degree of the pressure reducing valve 35 is controlled by a control section (not shown). The pressure reducing valve 35 is controlled so that the inside of the steam generator 27 reaches a desired pressure in coordination with the operation of each steam compressor 37 as necessary.

[0025] A steam supply passage (steam supply section) 31 through which the negative pressure steam generated in the steam generator 27 flows out is connected to the steam generator 27. The negative pressure steam generated in the steam generator 27 is generated by hot water below 100°C supplied from the hot water circuit 25. For example, when the pressure of the feed water is -0.054 MPaG, the saturated steam is 80°C, so negative pressure steam can be generated with hot water at about 85°C.

[0026] A plurality of steam compressors 37 and a supply amount adjustment section 39 are provided in the steam supply passage 31. Each steam compressor 37 compresses the negative pressure steam to a pressure equal to or higher than atmospheric pressure. As the steam compressor 37, for example, a positive displacement compressor such as a screw compressor or a claw compressor, or a turbo compressor is used. Further, due to the operation of the steam compressor 37, the flow path in the range from its upstream side to the downstream side of the pressure reducing valve 35 is depressurized. The steam compressor 37 is driven by, for example, an electric motor, and its rotation speed is controlled by a control section (not shown). In the present embodiment shown in FIG. 1, four steam compressors 37 are arranged in series, but the number is not limited and may be one, two, three, or five or more.

[0027] The supply amount adjustment section 39 separates the pressurized steam into gas and liquid and adjusts the steam flow rate to be discharged. The steam flow rate discharged from the supply amount adjustment section 39 is controlled by a control section (not shown).

[0028] On the downstream side of each vapor compressor 37 and the supply amount adjustment unit 39, a part of the feed water is led from the feed water passage 29 via the water injection pipe 41. By injecting the feed water led from the water injection pipe 41, the pressurized vapor and the vapor led to the supply amount adjustment unit 39 are cooled. Note that a pressure boosting means (such as a pump) may be provided in the water injection pipe 41 to obtain the pressure required for injection.

[0029] The pressurized vapor flowing out from the supply amount adjustment unit 39 passes through the vapor supply passage 31 and merges into the boiler vapor branch passage 13a. In this way, the vapor led from the supply amount adjustment unit 39 merges into the boiler vapor branch passage 13a and is led to the reboiler 17 of the CO2 recovery device 7.

[0030] A turbine 14 is provided on the upstream side of the confluence position P1 where the vapor supply passage 31 merges into the boiler vapor branch passage 13a. The turbine 14 reduces the pressure of the vapor and recovers the pressure energy. Note that an expansion valve may be provided instead of the turbine 14.

[0031] The control unit is composed of, for example, a CPU (Central Processing Unit), a RAM (Random Access Memory), a ROM (Read Only Memory), and a computer-readable storage medium, etc. A series of processes for realizing various functions are stored in a storage medium, etc. in the form of a program as an example. The CPU reads this program into the RAM, etc., and executes information processing and arithmetic processing, whereby various functions are realized. Note that the program may be in a form pre-installed in the ROM or other storage media, a form provided in a state stored in a computer-readable storage medium, a form distributed via wired or wireless communication means, etc. A computer-readable storage medium is a magnetic disk, a magneto-optical disk, a CD-ROM, a DVD-ROM, a semiconductor memory, etc.

[0032] The above-described cogeneration system 1A operates as follows. Power generation is performed by operating the gas engine 3, and the exhaust gas discharged from the gas engine 3 passes through the exhaust gas boiler 5 and is led to the CO2 recovery device 7. The steam generated in the exhaust gas boiler 5 is supplied to the demand destination through the boiler steam supply path 13. A part of the steam generated in the exhaust gas boiler 5 is branched at the boiler steam branch path 13a, decompressed by the turbine 14, and then led to the reboiler 17 of the CO2 recovery device 7. The steam generated by the steam generator 27 and pressurized by each steam compressor 37 also merges into the boiler steam branch path 13a.

[0033] Warm water below 100°C heated by the cooling water that cools the gas engine 3 circulates in the warm water circuit 25. The warm water below 100°C is decompressed by the pressure reducing valve 35 to form negative pressure water, which is heated by the steam generator 27 to generate negative pressure steam. The negative pressure steam generated by the steam generator 27 passes through the steam supply path 31, is pressurized to above atmospheric pressure by a plurality of steam compressors 37, and then led to the supply amount adjustment unit 39. The steam whose flow rate is adjusted by the supply amount adjustment unit 39 passes through the steam supply path 31 and merges with the boiler steam branch path 13a. The steam after merging at the boiler steam branch path 13a is led to the reboiler 17 and used as a heating source.

[0034] In the CO2 recovery device 7, CO2 is recovered from the exhaust gas led from the gas engine 3 in the absorption tower 15, and the exhaust gas after CO2 absorption is discharged to the outside. In the regeneration tower 16, the amine absorption liquid is heated by the reboiler 17. The CO2 desorbed from the amine absorption liquid is discharged from the regeneration tower 16 and sent to the CO2 storage section.

[0035] The functions and effects of the present embodiment described above are as follows. The negative-pressure water is heated using warm water below 100°C to generate steam. This enables the generation of steam even from warm water below 100°C, which has relatively low thermal utilization value. That is, even if the heat energy generated by the CO2 source recovered by the CO2 recovery device 7 is relatively low-temperature, such as warm water below 100°C, it can be effectively utilized in the CO2 recovery process. Therefore, without using heat sources or steam generation means other than the CO2 source, by supplying the steam generated by the steam generator 27 to the CO2 recovery device 7 as a heat source, CO2 can be desorbed from the amine absorption liquid.

[0036] A pressure reducing valve 35 is provided in the water supply line 29 that supplies water to the steam generator 27, and the supplied water is made into negative-pressure water below atmospheric pressure. This allows the supply of negative-pressure water to the steam generator 27 even with water supply above atmospheric pressure.

[0037] Even when directly supplying the negative-pressure steam generated by the steam generator 27 to the CO2 recovery device 7, the sensible heat of the negative-pressure steam can be utilized, and heat can be supplied to the CO2 recovery device 7 with equipment that is less costly than installing a warm water pipe. On the other hand, it is also possible to boost the pressure of the negative-pressure steam above atmospheric pressure by the steam compressor 37 and supply it to the CO2 recovery device 7. This enables flexible response to the required pressure of the CO2 recovery device 7. At this time, if necessary, the pressure reducing valve 35 is controlled by a control unit (not shown) in coordination with the operation of each steam compressor 37, and steam of a desired temperature, pressure, or flow rate can be supplied to the CO2 recovery device 7. Also, by this control unit, fluctuations in the temperature, pressure, or flow rate of the steam supplied to the CO2 recovery device 7 can be suppressed regardless of fluctuations in the amount of heat per unit time supplied by the warm water circuit 25.

[0038] It was decided to generate negative-pressure steam in the steam generator 27 using warm water heated by the cooling water of the gas engine 3 that performs power generation. This enables the configuration of a system capable of combined heat and power supply. In particular, when the CO2 source to be recovered is an engine generator, although the total energy is large, the thermal energy of the engine cooling water below 100°C, which could not be effectively utilized conventionally due to its low temperature, can be utilized in the CO2 recovery process. Therefore, high-temperature and high-pressure steam energy such as steam generated by an exhaust gas boiler using engine exhaust gas can be effectively utilized for other industrial applications.

[0039] [Second Embodiment] The second embodiment of the present disclosure will be described below. This embodiment differs from the first embodiment in the configurations of the turbine and the steam compressor, and is otherwise the same. Therefore, in the following description, the same components will be denoted by the same reference numerals and their description will be omitted.

[0040] FIG. 2 shows a combined heat and power system 1B according to this embodiment. In FIG. 2, the CO2 recovery device 7 in FIG. 1 is shown omitted, but the combined heat and power system 1B of this embodiment includes the CO2 recovery device 7 as in FIG. 1.

[0041] As shown in FIG. 2, the steam compressor 37A (37) of the final stage (the fourth stage), which is located at the most downstream of the four steam compressors 37, is connected by a common rotating shaft 44 to the turbine 14. Thereby, the power recovered by the turbine 14 is transmitted to the impeller of the steam compressor 37A.

[0042] Upstream of the turbine 14, a plurality of variable nozzle assemblies 45 for controlling the steam flow rate are provided. As shown in FIG. 3, the variable nozzle assembly 45 includes a plurality of variable nozzles 45a at a predetermined interval in the circumferential direction on the upstream side (outer side) of the outer circumference of the turbine 14. Each variable nozzle 45a rotates synchronously around a rotation shaft 45b. The angle of each variable nozzle 45a is controlled by a control unit (not shown). By changing the angle of each variable nozzle 45a to change the flow passage area, the flow rate flowing into the turbine 14 is variably adjusted. The turbine 14 is a variable geometry (VG) turbine by virtue of including the variable nozzle assembly 45.

[0043] A pressure equalizing pipe 46 is provided between the outlet of the steam compressor 37A and the outlet of the turbine 14. The pressure equalizing pipe 46 makes the outlet pressure of the steam compressor 37A and the outlet pressure of the turbine 14 substantially uniform. Note that instead of the pressure equalizing pipe 46, a pressure equalizing flow path may be provided inside the main body of a turbocharger configured by integrating the steam compressor 37A and the turbine 14.

[0044] According to this embodiment, the following operational effects are achieved. Since power is recovered from the boiler steam generated in the exhaust gas boiler 5 by the turbine 14 to drive the steam compressor 37A, the energy efficiency can be improved.

[0045] The steam compressor 37A and the turbine 14 are connected by a common rotating shaft 44, and the outlet steam of the steam compressor 37A and the outlet steam of the turbine 14 are equalized by the pressure equalizing pipe 46. As a result, the thrust force applied to the rotating shaft 44 can be reduced by canceling out the thrust force due to the outlet steam applied to the steam compressor 37A and the thrust force due to the outlet steam applied to the turbine 14.

[0046] Since the turbine 14 is a variable capacity turbine equipped with a variable nozzle assembly 45, power can be recovered with little loss even if the pressure of the boiler steam from which the turbine 14 recovers power fluctuates.

[0047] Note that a motor generator may be applied to the rotating shaft 44 connecting the steam compressor 37A and the turbine 14. The motor generator is controlled by a control unit (not shown). When the recovered power by the turbine 14 is greater than the required power of the steam compressor 37A, the motor generator is used as a generator. When the recovered power by the turbine 14 is less than the required power of the steam compressor 37A, the motor generator is used as a motor (electric motor). Thereby, the steam compressor 37A can be operated flexibly even if the pressure of the boiler steam from which the turbine 14 recovers power fluctuates.

[0048] In addition, although the final-stage steam compressor 37A is connected to the turbine 14, the steam compressor 37 that provides the recovered power of the turbine 14 may be a compressor in another stage (the first stage, the second stage, or the third stage).

[0049] In addition, a foil gas bearing may be adopted as the bearing of the turbine 14 in each of the above-described embodiments to achieve oil-free operation.

[0050] The steam generation system for a CO2 recovery device, the CO2 recovery device including the same, and the steam generation method for a CO2 recovery device described in each of the embodiments described above are understood as follows, for example.

[0051] The steam generation system for a CO2 recovery device according to the first aspect of the present disclosure includes a steam generator (27) that heats negative-pressure water with a heat medium to generate steam, and a steam supply unit (31) that supplies the steam generated by the steam generator to the CO2 recovery device. The heat medium is cooling water of a CO2 generation source recovered by the CO2 recovery device or a heat medium heated by the cooling water.

[0052] Negative-pressure water is heated using a heat medium below 100°C to generate negative-pressure steam. As a result, steam can be generated even with a heat medium below 100°C that has relatively low thermal utilization value. By supplying the negative-pressure steam generated in the steam generator to the CO2 recovery device as a heat source, CO2 can be desorbed from the adsorbent.

[0053] The steam generation system for a CO2 recovery device according to the second aspect of the present disclosure includes, in the first aspect, a water supply unit (29) that supplies water to the steam generator, and a pressure reducing valve (35) that is provided in the water supply unit and reduces the pressure of water to below atmospheric pressure.

[0054] A pressure reducing valve is provided in the water supply unit that supplies water to the steam generator to make the water negative-pressure water below atmospheric pressure. As a result, even water above atmospheric pressure can be supplied to the steam generator as negative-pressure water.

[0055] The steam generation system for a CO2 recovery device according to the third aspect of the present disclosure is, in the first aspect or the second aspect, wherein the steam supply unit includes a steam compressor (37) that boosts negative pressure steam to a pressure equal to or higher than atmospheric pressure.

[0056] The negative pressure steam is boosted to a pressure equal to or higher than atmospheric pressure by the steam compressor and supplied to the CO2 recovery device. Thereby, it is possible to flexibly respond to the required pressure of the CO2 recovery device.

[0057] The steam generation system for a CO2 recovery device according to the fourth aspect of the present disclosure is, in any one of the first aspect to the third aspect, provided with a turbine (14) that recovers power from the boiler steam generated by the boiler, and the steam compressor is driven by the turbine.

[0058] Since power is recovered from the boiler steam generated by the boiler by the turbine to drive the steam compressor, the energy efficiency can be improved. As the boiler, for example, a waste heat recovery boiler that generates steam by the exhaust gas discharged from an internal combustion engine (such as a power generation engine) can be used.

[0059] The steam generation system for a CO2 recovery device according to the fifth aspect of the present disclosure is, in the fourth aspect, wherein the steam compressor and the turbine are connected by a common rotating shaft (44), and the outlet steam of the steam compressor and the outlet steam of the turbine are equalized in pressure.

[0060] The steam compressor and the turbine are connected by a common rotating shaft, and the outlet steam of the steam compressor and the outlet steam of the turbine are equalized in pressure. Thereby, the thrust force acting on the rotating shaft can be reduced.

[0061] The steam generation system for a CO2 recovery device according to the sixth aspect of the present disclosure is, in the fourth aspect or the fifth aspect, wherein the steam compressor and the turbine are connected to a motor generator.

[0062] Since the vapor compressor and the turbine are connected to the motor generator, when the recovered power by the turbine is greater than the required power of the vapor compressor, the motor generator is used as a generator, and when the recovered power by the turbine is less than the required power of the vapor compressor, the motor generator is used as a motor. Thereby, even if the pressure of the boiler steam from which the turbine recovers power fluctuates, the vapor compressor can be operated flexibly.

[0063] In the steam generation system for a CO2 recovery device according to the seventh aspect of the present disclosure, in any one of the fourth aspect to the sixth aspect, the turbine is a variable capacity turbine.

[0064] Since the turbine is a variable geometry (VG) turbine, power can be recovered with less loss even if the pressure of the boiler steam from which the turbine recovers power fluctuates.

[0065] In the steam generation system for a CO2 recovery device according to the eighth aspect of the present disclosure, in any one of the first aspect to the seventh aspect, the temperature of the heat medium is obtained from cooling water that cools the engine (3) for power generation.

[0066] The temperature of the heat medium below 100 °C is obtained from the cooling water of the engine for power generation. Thereby, a system capable of combined heat and power supply can be configured.

[0067] The CO2 recovery device according to the first aspect of the present disclosure includes the steam generation system for a CO2 recovery device described in any of the above.

[0068] The steam generation method for a CO2 recovery device according to the first aspect of the present disclosure includes a steam generation step of heating negative pressure water with a heat medium to generate steam, and a steam supply step of supplying the steam generated in the steam generation step to the CO2 recovery device, wherein the heat medium is cooling water of a CO2 generation source recovered by the CO2 recovery device or a heat medium heated by the cooling water.

Description of Signs

[0069] 1A, 1B Cogeneration System 3 Gas Engine (Power Generation Engine) 5 Exhaust Gas Boiler (Waste Heat Recovery Boiler) 7 CO2 Recovery Device 9 Steam Generation System (Steam Generation System for CO2 Recovery Device) 11 Exhaust Gas Flow Path 13 Boiler Steam Supply Path 13a Boiler Steam Branch Path (Steam Supply Section) 14 Turbine 15 Absorption Tower 15a Lean Solution Supply Section 16 Regeneration Tower 16a Rich Solution Supply Section 16b Absorbent Recovery Path 16c Absorbent Return Path 17 Reboiler 18 Regeneration Tower Pump 20 Heat Exchanger 22 Absorption Tower Pump 25 Warm Water Circuit 27 Steam Generator 29 Water Supply Path (Water Supply Section) 31 Steam Supply Path (Steam Supply Section) 33 Warm Water Pump 35 Pressure Reducing Valve 37 Steam Compressor 39 Supply Quantity Adjustment Section 41 Water Injection Pipe 44 Rotating Shaft 45 Variable Nozzle Assembly 45a Variable Nozzle 45b Rotating Axis 46 Equalizing Pipe

Claims

1. A steam generator that heats negative-pressure water with a heat medium to generate negative-pressure steam, A steam supply unit that supplies the steam generated by the steam generator to a CO₂ recovery device, Comprising, The heat medium is cooling water of a CO₂ generation source recovered by the CO₂ recovery device or a heat medium heated by the cooling water, a steam generation system for a CO₂ recovery device.

2. A water supply unit that supplies water to the steam generator, A pressure reducing valve provided in the water supply unit for reducing the pressure of water to below atmospheric pressure, The steam generation system for a CO₂ recovery device according to claim 1, comprising.

3. The steam supply unit is provided with a steam compressor for boosting the negative-pressure steam to above atmospheric pressure, the steam generation system for a CO₂ recovery device according to claim 1.

4. Comprising a turbine for recovering power from the boiler steam generated by a boiler, The steam compressor is driven by the turbine, the steam generation system for a CO₂ recovery device according to claim 3.

5. The steam compressor and the turbine are connected by a common rotating shaft, The outlet steam of the steam compressor and the outlet steam of the turbine are equalized, the steam generation system for a CO₂ recovery device according to claim 4.

6. The steam compressor and the turbine are connected to a motor generator, the steam generation system for a CO₂ recovery device according to claim 4.

7. The turbine is a variable-capacity turbine, the steam generation system for a CO₂ recovery device according to claim 4.

8. The temperature of the heat medium is obtained from the cooling water for cooling the power generation engine, the steam generation system for a CO₂ recovery device according to claim 1.

9. A CO₂ recovery device comprising the steam generation system for a CO₂ recovery device according to any one of claims 1 to 8.

10. A steam generation step of heating negative-pressure water with a heat medium to generate steam, A steam supply step of supplying the negative-pressure steam generated in the steam generation step to a CO₂ recovery device, Having, The heat medium is cooling water of a CO₂ generation source recovered by the CO₂ recovery device or a heat medium heated by the cooling water, a steam generation method for a CO₂ recovery device.

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