Heat utilization system and heat utilization method

Abstract

To provide a heat utilization system that can supply a sufficient amount of heat to a heat demand facility.SOLUTION: A heat utilization system comprises: a heat recovery device for generating first steam, and second steam having lower pressure than that of the first steam, from water by exchanging heat between heating fluid and the water; a discharge source for discharging the heating fluid; a first steam turbine to be driven by the first steam; a pressure reducing member for reducing the pressure of exhaust steam that is steam having driven the first steam turbine; a heat demand facility for using heat of at least one of at least a portion of the exhaust steam or the second steam; an exhaust steam line for establishing communication between the first steam turbine and the heat demand facility; and a second steam line through which the second steam flows out of the heat recovery device. The second steam line is connected to the exhaust steam line downstream of the pressure reducing member.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to a heat utilization system and a heat utilization method. [Background technology]

[0002] Each of Patent Documents 1 to 3 describes a configuration in which part of the steam (exhaust steam) discharged from an intermediate-pressure steam turbine is used as a heat source for a carbon dioxide recovery unit. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2012-184712 [Patent Document 2] Special Publication No. 2013-506091 [Patent Document 3] Japanese Patent Application Laid-Open No. 2014-29139 Summary of the Invention [Problem to be solved by the invention]

[0004] However, in all of the systems disclosed in Patent Documents 1 to 3, the exhaust steam from the steam turbine is used as the heat source for the carbon dioxide capture device, which poses a problem that a sufficient amount of heat may not be supplied to the carbon dioxide capture device.

[0005] In view of the above circumstances, an object of at least one embodiment of the present disclosure is to provide a heat utilization system and a heat utilization method that can supply a sufficient amount of heat to heat-demanding equipment. [Means for solving the problem]

[0006] In order to achieve the above object, a heat utilization system according to the present disclosure includes a heat recovery device that generates first steam and second steam having a lower pressure than the first steam from water by heat exchange between a heating fluid and the water, an exhaust source that discharges the heating fluid, a first steam turbine that is driven by the first steam, a pressure reducing member that reduces the pressure of exhaust steam that is steam after driving the first steam turbine, heat demand equipment that utilizes heat from at least a portion of the exhaust steam or at least one of the second steam, and an exhaust steam line that connects the first steam turbine and the heat demand equipment. a first steam line through which the first steam flows out from the heat recovery device; a second steam line through which the second steam flows out of the heat recovery device, the second steam line being connected to the exhaust steam line downstream of the pressure reduction member. The heat recovery device includes a first steam generating unit that generates the first steam and a second steam generating unit that generates the second steam, the first steam line having an upstream end connected to the first steam generating unit and a downstream end connected to the first steam turbine, and the second steam line having an upstream end connected to the second steam generating unit and a downstream end connected to the exhaust steam line. are.

[0007] A heat utilization system according to the present disclosure includes a heat recovery device that generates first steam from water by heat exchange between a heating fluid and the water, a discharge source that discharges the heating fluid, a first steam turbine that is driven by the first steam, a pressure reduction member that reduces the pressure of exhaust steam that is steam after driving the first steam turbine, and heat demand equipment that utilizes heat of at least a portion of the exhaust steam downstream of the pressure reduction member, the pressure reduction member is configured so that a pressure reduction amount of the exhaust steam increases as a flow path area of ​​the pressure reduction member decreases; The pressure reduction member adjusts the amount of pressure reduction of the exhaust steam based on the heat demand in the heat demand facility.

[0008] A heat utilization method according to the present disclosure includes the steps of discharging a heated fluid from a discharge source, generating first steam from the water by exchanging heat between the heated fluid and water, driving a first steam turbine with the first steam, reducing the pressure of exhaust steam that is the steam after driving the first steam turbine, and supplying the reduced-pressure exhaust steam to heat-demanding equipment, wherein the step of reducing the pressure of the exhaust steam includes adjusting an amount of pressure reduction of the exhaust steam based on heat demand in the heat-demanding equipment. The pressure reducing member that reduces the pressure of the exhaust steam is configured so that the amount of pressure reduction of the exhaust steam increases as the flow path area of ​​the pressure reducing member decreases. . [Effects of the Invention]

[0009] According to the heat utilization system of the present disclosure, not only the exhaust steam, which is the steam after driving the first steam turbine, but also the second steam supplied from the heat recovery device can be used as a heat source for the heat demand equipment, so that a sufficient amount of heat can be supplied to the heat demand equipment.

[0010] Furthermore, according to the heat utilization system and heat utilization method disclosed herein, increasing the pressure drop of the exhaust steam increases the pressure at the inlet of the pressure reduction member, i.e., the outlet of the first steam turbine, decreasing the pressure expansion ratio of the first steam turbine and decreasing the output of the first steam turbine. This increases the temperature of the exhaust steam, making it possible to increase the amount of heat supplied to the heat-demanding facility, and thus ensure that a sufficient amount of heat can be supplied to the heat-demanding facility. [Brief explanation of the drawings]

[0011] [Figure 1] 1 is a schematic diagram illustrating the configuration of a heat utilization system according to a first embodiment of the present disclosure. [Figure 2] 1 is a schematic diagram illustrating the configuration of a heat recovery device of a heat utilization system according to a first embodiment of the present disclosure. [Figure 3] 3 is a TQ diagram of condensate and exhaust gas in a low-pressure evaporator when the heat recovery device of the heat utilization system according to the first embodiment of the present disclosure has the configuration shown in FIG. 2. FIG. [Figure 4] 1 is a schematic diagram illustrating a configuration for controlling the opening degree or flow path area of ​​a pressure regulating valve in a heat utilization system according to a first embodiment of the present disclosure. FIG. [Figure 5] 1 is a schematic diagram illustrating a configuration for controlling an exhaust steam supply amount adjustment member in a heat utilization system according to a first embodiment of the present disclosure. FIG. [Figure 6] 1 is an example of a pressure reduction member that can be used in the heat utilization system according to the first embodiment of the present disclosure. [Figure 7] 1 is an example of a pressure reduction member that can be used in the heat utilization system according to the first embodiment of the present disclosure. [Figure 8] 1 is an example of a pressure reduction member that can be used in the heat utilization system according to the first embodiment of the present disclosure. [Figure 9] 1 is an example of a pressure reduction member that can be used in the heat utilization system according to the first embodiment of the present disclosure. [Figure 10] 1 is an example of a pressure reduction member that can be used in the heat utilization system according to the first embodiment of the present disclosure. [Figure 11] FIG. 11 is a cross-sectional view taken along line XI-XI in FIG. [Figure 12] FIG. 10 is a schematic diagram illustrating the configuration of a heat utilization system according to a second embodiment of the present disclosure. [Figure 13] FIG. 10 is a configuration diagram of a modified example of the heat utilization system according to the second embodiment of the present disclosure. [Figure 14] FIG. 10 is a schematic diagram illustrating the configuration of a heat utilization system according to a third embodiment of the present disclosure. DETAILED DESCRIPTION OF THE INVENTION

[0012] Hereinafter, a heat utilization system and a heat utilization method according to embodiments of the present disclosure will be described with reference to the drawings. The embodiments described below represent one aspect of the present disclosure, and are not intended to limit the present disclosure. Modifications can be made as desired within the scope of the technical concept of the present disclosure.

[0013] (Embodiment 1) <Configuration of heat utilization system according to embodiment 1 of the present disclosure> 1 , a heat utilization system 1 according to a first embodiment of the present disclosure includes a heat recovery unit 30 that generates first steam and second steam having a lower pressure than the first steam from water by heat exchange between a heating fluid and water (including not only liquid water but also steam), a gas turbine 20 that serves as an exhaust source for discharging the heating fluid, a steam turbine 40, a pressure control valve 50a that serves as a pressure reduction member 50 that reduces the pressure of exhaust steam, which is steam after driving the steam turbine 40, a heat demand facility 60 that utilizes heat from at least a portion of the exhaust steam or at least one of the second steam, an exhaust steam line 51 that connects the steam turbine 40 and the heat demand facility 60, and a second steam line 32 through which the second steam flows out of the heat recovery unit 30. The second steam line 32 is connected to the exhaust steam line 51 downstream of the pressure reduction member 50.

[0014] The exhaust steam line 51 is provided with a heat demand facility inlet valve 52. By opening and closing the heat demand facility inlet valve 52, it is possible to start or stop the supply of at least a portion of the exhaust steam or at least one of the second steam to the heat demand facility 60. The heat demand facility inlet valve 52 is not limited to an on-off valve, and may be a flow control valve that can adjust the flow rate of at least a portion of the exhaust steam or at least one of the second steam. The exhaust steam line 51 may be provided with an on-off valve 53 between the pressure adjustment valve 50a and the heat demand facility inlet valve 52. By providing the on-off valve 53, the supply of exhaust steam to the heat demand facility 60 is stopped, making it possible to supply only the second steam to the heat demand facility 60.

[0015] The configuration of the heat demand facility 60 is not particularly limited, and may include a heat exchange mechanism that heats a solid, liquid, or gaseous object to be heated with heat from at least a portion of the exhaust steam or at least one of the second steam, or may be a chemical device (e.g., a steam reforming device) that uses the exhaust steam as a raw material for a chemical reaction. In the first embodiment, an example will be described in which the heat demand facility 60 is a district hot water supply / heating facility 60a.

[0016] Although the configuration of the steam turbine 40 is not particularly limited in the present disclosure, in the first embodiment, the steam turbine 40 includes a high-pressure turbine 40a, an intermediate-pressure turbine 40b, and a low-pressure turbine 40c. The high-pressure turbine 40a and the intermediate-pressure turbine 40b are connected to each other by their respective rotating shafts, and a power generation device 41 is provided that is driven by the rotation of the rotating shafts. The low-pressure turbine 40c is provided independently of the high-pressure turbine 40a and the intermediate-pressure turbine 40b, and the intermediate-pressure turbine 40b and the low-pressure turbine 40c are connected to each other via an exhaust steam branch line 54 that branches off from the exhaust steam line 51 downstream of the pressure regulating valve 50a. In other words, the low-pressure turbine 40c is configured to be driven by at least a portion of the exhaust steam discharged from the intermediate-pressure turbine 40b. The exhaust steam branch line 54 is provided with a low-pressure turbine inlet valve 55, which is a flow rate regulating valve. The low-pressure turbine 40c is provided with a power generation device 42 that is driven by the low-pressure turbine 40c.

[0017] In this disclosure, a steam turbine that discharges exhaust steam to be supplied to heat demanding equipment 60 is defined as a first steam turbine, and a steam turbine driven by the exhaust steam from the first steam turbine is defined as a second steam turbine. Also, steam that drives the first steam turbine is defined as first steam. Therefore, in the first embodiment, the intermediate-pressure turbine 40b corresponds to the first steam turbine, and the low-pressure turbine 40c corresponds to the second steam turbine. Details of the first steam that drives the intermediate-pressure turbine 40b, which is the first steam turbine in the first embodiment, will be described later.

[0018] An exhaust steam line 70, through which exhaust steam discharged from the low-pressure turbine 40c flows, is connected to a condenser 71. In order to supply the condensate generated in the condenser 71 to the heat recovery device 30, the condenser 71 and the heat recovery device 30 are communicated by a condensate line 72. A condensate pump 73 is provided in the condensate line 72 to supply the condensate to the heat recovery device 30. A discharge line 61 for steam used in the district hot water supply / heating facility 60a is connected to the exhaust steam line 70 downstream of the condensate pump 73. A pressure regulating valve 62 and a pump 63 located downstream of the pressure regulating valve 62 are provided in the discharge line 61.

[0019] The gas turbine 20 includes a compressor 21 that compresses air, a combustor 22 that burns fuel using the compressed air compressed by the compressor 21, and a turbine 23 that is driven by combustion gas generated by burning the fuel in the combustor 22. A fuel supply line 12 for supplying fuel is connected to the combustor 22. Also, a power generation device 26 that is driven by the gas turbine 20 is provided.

[0020] The turbine 23 and the heat recovery device 30 are connected via an exhaust gas line 28 to supply exhaust gas discharged from the turbine 23 to the heat recovery device 30. The heat recovery device 30 is configured so that condensate supplied to the heat recovery device 30 via a condensate line 72 exchanges heat with exhaust gas supplied to the heat recovery device 30 via the exhaust gas line 28, thereby heating the condensate and generating two steam streams of different pressures. Here, the exhaust gas is a heating fluid that exchanges heat with the condensate, and the gas turbine 20 is an emission source that discharges the exhaust gas, which is a heating fluid. The heat recovery device 30 and the high-pressure turbine 40a are connected via a steam supply line 31 to supply the high-pressure steam generated in the heat recovery device 30 to the high-pressure turbine 40a. The low-pressure steam generated in the heat recovery device 30 corresponds to the second steam described above. The upstream end of a second steam line 32 is connected to the heat recovery device 30 so that the second steam flows out of the heat recovery device 30.

[0021] In order to supply exhaust steam from the high-pressure turbine 40a to the heat recovery device 30, the high-pressure turbine 40a and the heat recovery device 30 are connected via an exhaust steam line 43. The heat recovery device 30 is also configured to generate reheated steam by heating the exhaust steam supplied to the heat recovery device 30 via the exhaust steam line 43 through heat exchange between the exhaust steam and the exhaust gas supplied to the heat recovery device 30 via the exhaust gas line 28. In order to supply the reheated steam to the intermediate-pressure turbine 40b, the heat recovery device 30 and the intermediate-pressure turbine 40b are connected via a reheated steam supply line 33. In the first embodiment, the reheated steam that drives the intermediate-pressure turbine 40b, which is the first steam turbine, corresponds to the first steam.

[0022] An example of the configuration of the heat recovery device 30 that can generate first steam and second steam by the above-mentioned heat exchange in the heat recovery device 30 will be described with reference to Fig. 2. The heat recovery device 30 includes an exhaust gas flow path 200 through which exhaust gas supplied to the heat recovery device 30 via an exhaust gas line 28 flows. A low-pressure economizer 201, a low-pressure evaporator 202, and a low-pressure superheater 203 are provided within the exhaust gas flow path 200 as a configuration for generating second steam. A condensate line 72 is connected to the low-pressure economizer 201, and the low-pressure economizer 201 and the low-pressure evaporator 202 are connected, and the low-pressure evaporator 202 and the low-pressure superheater 203 are connected, and a second steam line 32 is connected to the low-pressure superheater 203. With this configuration, the condensate supplied to the heat recovery device 30 via the condensate line 72 is heated by heat exchange with the exhaust gas in the low-pressure economizer 201, the low-pressure evaporator 202, and the low-pressure superheater 203, successively, to become second steam, which flows out of the heat recovery device 30 and circulates through the second steam line 32.

[0023] Furthermore, a first reheater 204 and a second reheater 205 connected to each other are provided in the exhaust gas flow path 200 as a configuration for generating first steam. An exhaust steam line 43 is connected to the first reheater 204, and a reheated steam supply line 33 is connected to the second reheater 205. With this configuration, exhaust steam supplied to the heat recovery device 30 via the exhaust steam line 43 is heated by heat exchange with the exhaust gas in the first reheater 204 and the second reheater 205 successively, and becomes first steam (reheated steam). The first steam then flows out of the heat recovery device 30 and circulates through the reheated steam supply line 33.

[0024] The heat recovery system 30 may also have a configuration in which first steam is generated using a portion of the condensate supplied to the heat recovery system 30 via the condensate line 72. In this configuration, an intermediate-pressure economizer 206, an intermediate-pressure evaporator 207, and an intermediate-pressure superheater 208 are provided in the exhaust gas flow path 200. The intermediate-pressure economizer 206 is connected to the low-pressure economizer 201 via a line 209, and an intermediate-pressure feedwater pump 210 is provided on the line 209. The intermediate-pressure economizer 206 is connected to the intermediate-pressure evaporator 207, and the intermediate-pressure evaporator 207 is connected to the intermediate-pressure superheater 208. One end of a steam line 211 is connected to the intermediate-pressure superheater 208, and the other end of the steam line 211 is connected to the exhaust steam line 43. With this configuration, a portion of the condensate heated in the low-pressure economizer 201 is converted into steam by heat exchange with the exhaust gas as it flows sequentially through the medium-pressure economizer 206, the medium-pressure evaporator 207, and the medium-pressure superheater 208 by the medium-pressure feed water pump 210, and is mixed with the exhaust steam flowing through the exhaust steam line 43 via the steam line 211 and supplied again to the heat recovery device 30 to become the first steam.

[0025] Further, within the exhaust gas flow path 200, a first high-pressure economizer 212, a second high-pressure economizer 213, a high-pressure evaporator 214, a first high-pressure superheater 215, and a second high-pressure superheater 216 are provided as components for generating steam to be supplied to the high-pressure turbine 40a. The first high-pressure economizer 212 is connected to the low-pressure economizer 201 via a line 217, and a high-pressure feedwater pump 218 is provided on the line 217. The first high-pressure economizer 212 and the second high-pressure economizer 213 are connected, the second high-pressure economizer 213 and the high-pressure evaporator 214 are connected, the high-pressure evaporator 214 and the first high-pressure superheater 215 are connected, and the first high-pressure superheater 215 and the second high-pressure superheater 216 are connected. A steam supply line 31 is connected to the second high-pressure superheater 216. With this configuration, a portion of the condensate heated in the low-pressure economizer 201 is converted into steam by heat exchange with the exhaust gas as it flows sequentially through the first high-pressure economizer 212, the second high-pressure economizer 213, the high-pressure evaporator 214, the first high-pressure superheater 215, and the second high-pressure superheater 216 by the high-pressure feed water pump 218, and then flows out of the heat recovery device 30 and flows through the steam supply line 31.

[0026] In the above, a heating fluid (exhaust gas) is supplied to the heating fluid flow path (exhaust gas flow path 200) of the heat recovery device 30, and in the heating fluid flow path (exhaust gas flow path 200), the second high-pressure superheater 216 (in parallel with the second reheater 205), the first reheater 204, the first high-pressure superheater 215, the high-pressure evaporator 214, the second high-pressure economizer 213, the medium-pressure superheater 208, the medium-pressure evaporator 207, the medium-pressure economizer 206 (in parallel with the first high-pressure economizer 212), the low-pressure superheater 203, the low-pressure evaporator 202, and the low-pressure economizer 201 are arranged in this order from upstream to downstream of the flow of the heating fluid (exhaust gas). The heating fluid (exhaust gas) flowing in the heating fluid flow path (exhaust gas flow path 200) of the heat recovery unit 30 exchanges heat with steam or water flowing in the superheater, reheater, evaporator, or economizer, in that order, to heat the steam or water. Multiple evaporators (high-pressure evaporator 214, medium-pressure evaporator 207, and low-pressure evaporator 202) are installed in the heating fluid flow path (exhaust gas flow path 200) of the heat recovery unit 30. Of the multiple evaporators installed in the heating fluid flow path (exhaust gas flow path 200) of the heat recovery unit 30, the low-pressure evaporator 202 is installed most downstream in terms of the flow of the heating fluid (exhaust gas). Furthermore, of the multiple evaporators installed in the heating fluid flow path (exhaust gas flow path 200) of the heat recovery unit 30, the low-pressure evaporator 202 has the lowest evaporating steam pressure.

[0027] The heat utilization system of this embodiment includes three evaporators with different pressures: the high-pressure evaporator 214, the intermediate-pressure evaporator 207, and the low-pressure evaporator 202. However, it is also possible to include an evaporator with a higher pressure than the high-pressure evaporator 214, for a total of four evaporators. Alternatively, instead of the three evaporators, it is also possible to include only two evaporators: the high-pressure evaporator 214 and the low-pressure evaporator 202, and the intermediate-pressure evaporator 207 and the low-pressure evaporator 202. In the heat utilization system 1 of the first embodiment, the steam after driving the high-pressure turbine 40a is sent to a reheater for reheating. However, the outlet of the high-pressure turbine 40a may be directly connected to the inlet of the intermediate-pressure turbine 40b without including a reheater. In this case, a steam line 211 may be connected to the steam flow path directly connecting the outlet of the high-pressure turbine 40a and the inlet of the intermediate-pressure turbine 40b, and the steam evaporated in the intermediate-pressure evaporator 207 may be supplied to the inlet of the intermediate-pressure turbine 40b together with the steam after driving the high-pressure turbine 40a. Furthermore, in this case, the high-pressure turbine 40a and the intermediate-pressure turbine 40b may be integrated, and a steam line 211 may be connected to an intermediate stage of the turbine to supply steam evaporated in the intermediate-pressure evaporator 207. As described above, the heat recovery system 30 and the steam turbine 40 may employ various configurations within the scope of the present invention.

[0028] One end of an exhaust gas line 29 is connected to the heat recovery device 30 so that the exhaust gas that has exchanged heat with the condensate and the exhaust steam of the high-pressure turbine 40a in the heat recovery device 30 flows out of the heat recovery device 30. The other end of the exhaust gas line 29 is connected to the chimney 10.

[0029] <Operation of the heat utilization system according to the first embodiment of the present disclosure (heat utilization method)> Next, the operation of the heat utilization system according to the first embodiment of the present disclosure will be described. Fuel is supplied to the combustor 22 of the gas turbine 20 via the fuel supply line 12. The combustor 22 is supplied with fuel and compressed air compressed by the compressor 21, and the fuel is combusted using the compressed air. Combustion gas generated by the combustion of the fuel in the combustor 22 drives the turbine 23. The rotation of the compressor 21 and the turbine 23 drives the power generation device 26, generating electricity.

[0030] The exhaust gas discharged from the turbine 23 flows into the heat recovery unit 30 via an exhaust gas line 28. In the heat recovery unit 30, the exhaust gas is cooled by heat exchange with water. As will be described later, the exhaust gas is also cooled by heat exchange between the exhaust steam discharged from the high-pressure turbine 40a and the exhaust gas. The exhaust gas cooled in the heat recovery unit 30 flows through an exhaust gas line 29 and is released into the atmosphere via the chimney 10.

[0031] Meanwhile, water heated by heat exchange with the exhaust gas in the heat recovery unit 30 flows out of the heat recovery unit 30 as two types of steam with different pressures. The high-pressure steam is supplied to the high-pressure turbine 40a via the steam supply line 31 and drives the high-pressure turbine 40a. On the other hand, the low-pressure steam flows through the second steam line 32 as second steam. The exhaust steam discharged from the high-pressure turbine 40a after driving the high-pressure turbine 40a flows through the exhaust steam line 43 and flows back into the heat recovery unit 30. In the heat recovery unit 30, the exhaust steam discharged from the high-pressure turbine 40a is heated by heat exchange with the exhaust gas and becomes reheated steam (first steam). The reheated steam is supplied to the intermediate-pressure turbine 40b via the reheat steam supply line 33 and drives the intermediate-pressure turbine 40b. The power generation unit 41 is driven by the high-pressure turbine 40a and the intermediate-pressure turbine 40b to generate electricity.

[0032] The exhaust steam discharged from the intermediate-pressure turbine 40b after driving the intermediate-pressure turbine 40b flows through an exhaust steam line 51. By operating a heat demand facility inlet valve 52, an on-off valve 53, and a low-pressure turbine inlet valve 55, the exhaust steam flows into either the low-pressure turbine 40c or the district hot water supply and heating facility 60a, or into both the low-pressure turbine 40c and the district hot water supply and heating facility 60a. The exhaust steam supplied to the low-pressure turbine 40c through an exhaust steam branch line 54 drives the low-pressure turbine 40c, which drives the power generation device 42, thereby generating electricity.

[0033] The exhaust steam discharged from the low-pressure turbine 40c after driving the low-pressure turbine 40c flows through an exhaust steam line 70 and into a condenser 71. The exhaust steam that flows into the condenser 71 is condensed to become condensed water, which is then circulated through a condensate line 72 by a condensate pump 73 and supplied to the heat recovery device 30 where it exchanges heat with the exhaust gas.

[0034] When at least a portion of the exhaust steam discharged from the intermediate-pressure turbine 40b is supplied to the district hot water supply and heating system 60a, the exhaust steam is mixed with the second steam flowing through the second steam line 32 while flowing through the exhaust steam line 51 and flows into the district hot water supply and heating system 60a. As described above, by fully closing the on-off valve 53, only the second steam can be supplied to the district hot water supply and heating system 60a. The second steam (and the exhaust steam) flowing into the district hot water supply and heating system 60a is used as a heat source for hot water supply and heating. The pressure of the second steam (and the exhaust steam) in the district hot water supply and heating system 60a can be adjusted by the pressure regulating valve 62. By maintaining a sufficiently high pressure within the district hot water supply and heating system 60a, sufficient steam density and heat transfer coefficient can be obtained, thereby providing the required amount of heat and condensing the steam at the temperature required by the district hot water supply and heating system 60a. The second steam (and exhaust steam) used as a heat source in the district hot water supply and heating facility 60a condenses into water, which is circulated through the discharge line 61 by the pump 63, then flows into the condensate line 72 and is supplied to the heat recovery device 30 together with the condensate.

[0035] In this way, in the heat utilization system 1, not only the exhaust steam, which is the steam after driving the intermediate-pressure turbine 40b, but also the second steam supplied from the heat recovery device 30 can be used as a heat source for the district hot water supply and heating facility 60a, so that a sufficient amount of heat can be supplied to the district hot water supply and heating facility 60a.

[0036] <Control based on heat demand in heat demand facilities> Next, we will explain a method for controlling the amount of heat supplied to the district hot water supply and heating system 60a based on the heat demand in the district hot water supply and heating system 60a when at least a portion of the exhaust steam discharged from the intermediate-pressure turbine 40b is supplied to the district hot water supply and heating system 60a. For example, the amount of heat supplied to the district hot water supply and heating system 60a can be controlled by changing the aperture of the pressure regulating valve 50a. Reducing the aperture of the pressure regulating valve 50a, i.e., reducing the flow area of ​​the pressure regulating valve 50a, increases the amount of pressure drop (pressure loss) of the exhaust steam caused by the pressure regulating valve 50a. This increases the pressure at the inlet of the pressure regulating valve 50a, i.e., the outlet of the intermediate-pressure turbine 40b (first steam turbine), reduces the expansion ratio of the intermediate-pressure turbine 40b (first steam turbine), and reduces the output of the intermediate-pressure turbine 40b (first steam turbine). As a result, the temperature of the exhaust steam discharged from the intermediate-pressure turbine 40b (first steam turbine) increases. Therefore, the amount of heat supplied to the district hot water supply and heating system 60a increases. On the other hand, when the heat demand of the district hot water supply and heating system 60a is low, the opening degree of the pressure regulating valve 50a, i.e., the flow path area, is kept at a maximum. As the heat demand of the district hot water supply and heating system 60a increases, the opening degree of the pressure regulating valve 50a, i.e., the flow path area, is reduced, and the temperature of the exhaust steam discharged from the intermediate-pressure turbine 40b (first steam turbine) rises, so that an amount of heat corresponding to the heat demand of the district hot water supply and heating system 60a can be supplied to the district hot water supply and heating system 60a.

[0037] The effects of the heat recovery device 30 having the configuration shown in Fig. 2 will be described. The TQ diagram shown in Fig. 3 is a diagram showing a line indicating the relationship between the amount of heat recovered from the condensate and its temperature in the low-pressure evaporator 202 of the heat recovery device 30 (lines for when the saturated vapor pressure in the low-pressure evaporator 202 is high and when it is low), and a line indicating the relationship between the amount of heat recovered from the exhaust gas and its temperature. By lowering the saturated vapor pressure and saturated vapor temperature in the low-pressure evaporator 202, that is, by changing from the solid line in Fig. 3 when the saturated vapor pressure in the low-pressure evaporator 202 is high to the dashed line in Fig. 3 when the saturated vapor pressure in the low-pressure evaporator 202 is low, the amount of heat recovered in the latter case can be increased compared to the former case. In this embodiment, the pressure adjustment valve 50a (pressure reduction member) is provided to increase the amount of pressure drop (pressure loss), thereby maintaining a low pressure in the exhaust steam line 51 downstream of the pressure adjustment valve 50a (pressure reduction member). This also maintains a low saturated steam pressure in the second steam line 32 connected to the exhaust steam line 51 downstream of the pressure adjustment valve 50a (pressure reduction member) and in the low-pressure evaporator 202 of the heat recovery unit 30, which supplies steam to the second steam line 32. Therefore, as shown in FIG. 3 , the amount of heat recovered from the condensate in the low-pressure evaporator 202 of the heat recovery unit 30 can be increased. At the same time, the temperature of the exhaust steam discharged from the intermediate-pressure turbine 40b (first steam turbine) is increased by the above-mentioned operation, thereby further increasing the amount of heat that can be supplied to the district hot water supply / heating system 60a. In this embodiment, by providing a pressure regulating valve 50a (pressure reducing member) and increasing the amount of pressure drop (pressure loss), it is possible to increase the pressure upstream of the pressure regulating valve 50a (pressure reducing member) while maintaining a low pressure downstream of the pressure regulating valve 50a (pressure reducing member). Therefore, it is possible to maintain a low saturated steam pressure in the low-pressure evaporator 202 of the heat recovery system 30, while simultaneously increasing the temperature and heat quantity of the exhaust steam discharged from the intermediate-pressure turbine 40b (first steam turbine), and to increase the amount of heat supplied to the district hot water supply and heating system 60a (heat demand facility).

[0038] Next, we will explain the above-mentioned control of the opening or flow path area of ​​the pressure regulating valve 50a (pressure reducing member) to satisfy the heat demand of the district hot water supply and heating facility 60a (heat demand facility) when the heat demand changes. As shown in FIG. 4, the heat utilization system 1 is provided with a heat supply amount control device 501. The heat supply amount control device 501 includes a receiver 511 that receives a heat demand signal, which is a signal related to the heat demand of the district hot water supply and heating facility 60a (heat demand facility), from the district hot water supply and heating facility 60a (heat demand facility); a control signal generator 512 that uses the heat demand signal to generate a control signal, which is a signal for controlling the opening or flow path area of ​​the pressure regulating valve 50a; and a control signal transmitter 513 that transmits the control signal to the pressure regulating valve 50a. The receiver 511 is electrically connected to the control signal generator 512, and the control signal generator 512 is electrically connected to the control signal transmitter 513.

[0039] The receiver 511 is electrically connected to a controller 60a1 that controls the operation of the district hot water supply and heating facility 60a (heat demand facility), for example, the district hot water supply and heating facility 60a (heat demand facility), via a heat demand signal line 502 so as to receive a heat demand signal from the district hot water supply and heating facility 60a (heat demand facility). The control signal transmitter 513 is electrically connected to a driver of the pressure regulating valve 50a (pressure reducing member) via a control signal line 503 so as to transmit a control signal to a driver (not shown) that controls the opening or flow area of ​​the pressure regulating valve 50a (pressure reducing member). Note that if the transmission and reception of the heat demand signal between the receiver 511 and the district hot water supply and heating facility 60a (heat demand facility) and / or the transmission and reception of the control signal between the control signal transmitter 513 and the pressure regulating valve 50a (pressure reducing member) are performed wirelessly, then either or both of the heat demand signal line 502 and the control signal line 503 can be omitted.

[0040] The heat supply amount control device 501 is composed of, for example, a CPU (Central Processing Unit), RAM (Random Access Memory), ROM (Read Only Memory), and a computer-readable storage medium. A series of processes for realizing various functions is stored in a storage medium, for example, in the form of a program. The CPU reads this program into RAM and executes information processing and arithmetic operations to realize various functions. The program may be pre-installed in a ROM or other storage medium, provided in a state stored in a computer-readable storage medium, or distributed via wired or wireless communication means. Examples of computer-readable storage media include magnetic disks, magneto-optical disks, CD-ROMs, DVD-ROMs, and semiconductor memories.

[0041] When the heat supply amount control device 501 is provided, the heat demand of the district hot water supply and heating facility 60a (heat demand facility) is transmitted continuously or intermittently as a heat demand signal, and a receiver 511 of the heat supply amount control device 501 receives the heat demand signal. A control signal generator 512 uses the heat demand signal received by the receiver 511 to generate a control signal for controlling the aperture or flow area of ​​the pressure regulating valve 50a (pressure reduction member). For example, the control signal generator 512 may be pre-loaded with a map showing the relationship between the aperture or flow area of ​​the pressure regulating valve 50a (pressure reduction member) and the exhaust steam temperature, as well as a map showing the relationship between the amount of change in the exhaust steam flow rate and temperature and the amount of change in the heat demand of the district hot water supply and heating facility 60a (heat demand facility). The control signal generator 512 can then determine the aperture or flow area of ​​the pressure regulating valve 50a (pressure reduction member) based on these maps and generate a control signal. The control signal transmitter 513 transmits the control signal generated by the control signal generator 512 to a driver for the pressure regulating valve 50a. The drive unit of the pressure regulating valve 50a adjusts the opening degree or flow path area of ​​the pressure regulating valve 50a based on the control signal, thereby making it possible to set the opening degree or flow path area of ​​the pressure regulating valve 50a (pressure reduction member) according to the heat demand of the district hot water supply and heating facility 60a (heat demand facility).

[0042] When the heat demand of the district hot water supply and heating facility 60a (heat demand facility) is low, a control signal is generated to maximize the opening or flow area of ​​the pressure regulating valve 50a (pressure reduction member), i.e., a control signal to minimize the amount of pressure reduction; when the heat demand of the district hot water supply and heating facility 60a (heat demand facility) increases, a control signal is generated to decrease the opening or flow area of ​​the pressure regulating valve 50a (pressure reduction member), i.e., a control signal to increase the amount of pressure reduction; and when the heat demand of the district hot water supply and heating facility 60a (heat demand facility) decreases, a control signal is generated to increase the opening or flow area of ​​the pressure regulating valve 50a (pressure reduction member), i.e., a control signal to decrease the amount of pressure reduction.

[0043] As explained below, by adjusting the aperture of the pressure control valve 50a (pressure reduction member) as well as the aperture of the heat demand facility inlet valve 52 or the low-pressure turbine inlet valve 55 (exhaust steam supply rate adjustment member), which are flow rate adjustment valves, the amount of heat corresponding to the wide range of heat demand of the district hot water supply and heating facility 60a (heat demand facility) can be supplied to the district hot water supply and heating facility 60a (heat demand facility). As shown in Figure 1, when the heat demand of the district hot water supply and heating facility 60a (heat demand facility) is low, the aperture of the pressure control valve 50a (pressure reduction member), i.e., the flow path area, is maximized. The heat demand of the district hot water supply and heating facility 60a (heat demand facility) is compared with the heat supply rate to the district hot water supply and heating facility 60a (heat demand facility), and if the heat demand is greater, the aperture of the low-pressure turbine inlet valve 55 (exhaust steam supply rate adjustment member) is reduced. In this way, the amount of exhaust steam supplied to the low-pressure turbine 40c decreases, thereby increasing the amount of exhaust steam supplied to the district hot water supply and heating facility 60a (heat demand facility), and therefore the amount of heat supplied to the district hot water supply and heating facility 60a (heat demand facility) increases, thereby satisfying the heat demand of the district hot water supply and heating facility 60a (heat demand facility). Conversely, if the heat demand is smaller in the above comparison, the opening of the low-pressure turbine inlet valve 55 (exhaust steam supply rate adjustment member) is increased. In this way, the amount of exhaust steam supplied to the low-pressure turbine 40c (second steam turbine) increases, thereby decreasing the amount of exhaust steam supplied to the district hot water supply and heating facility 60a (heat demand facility), and therefore the amount of heat supplied to the district hot water supply and heating facility 60a (heat demand facility) decreases, thereby satisfying the heat demand of the district hot water supply and heating facility 60a (heat demand facility). In this case, the amount of pressure drop in the exhaust steam caused by the pressure control valve 50a (pressure reduction member) is minimized, so the heat demand of the district hot water supply and heating facility 60a (heat demand facility) can be met without reducing the output of the intermediate-pressure turbine 40b (first steam turbine). As described above, if the heat demand of the district hot water supply and heating facility 60a (heat demand facility) is low and the heat demand of the district hot water supply and heating facility 60a (heat demand facility) can be met even if the opening degree, i.e., the flow path area, of the pressure control valve 50a (pressure reduction member) is maximized and the amount of pressure drop (pressure loss) is minimized, it is preferable to maintain the opening degree, i.e., the flow path area, of the pressure control valve 50a (pressure reduction member) at its maximum and the amount of pressure drop (pressure loss) at its minimum.This is because the smaller the pressure drop (pressure loss) in the pressure regulating valve 50a (pressure drop member), the greater the output of the intermediate-pressure turbine 40b (first steam turbine), and the higher the efficiency of the plant.

[0044] Even if the low-pressure turbine inlet valve 55 (exhaust steam supply adjustment member) is fully closed and the supply of exhaust steam to the low-pressure turbine 40c (second steam turbine) is stopped, if the heat demand is greater in the above comparison, the heat demand of the district hot water supply and heating facility 60a (heat demand facility) can be met by adjusting the pressure and temperature of the exhaust steam by adjusting the opening of the above-mentioned pressure control valve 50a (pressure reduction member).

[0045] In the above control, the pressure control valve 50a (pressure reduction member) starts at a fully open position, but this is not limited to this. The pressure control valve 50a (pressure reduction member) may start at any opening position adjusted to maintain a desired output of the high-pressure turbine 40a and the intermediate-pressure turbine 40b. In this state, if the heat demand of the district hot water supply and heating system 60a (heat demand facility) cannot be met even when the low-pressure turbine inlet valve 55 (exhaust steam supply rate adjustment member) is fully closed, the pressure control valve 50a (pressure reduction member) may be adjusted to increase the heat supply to the district hot water supply and heating system 60a (heat demand facility).

[0046] In the above control, the heat supply to the district hot water supply and heating facility 60a (heat demand facility) is regulated by adjusting the opening of the low-pressure turbine inlet valve 55, but this is not limited to this form. The heat supply to the district hot water supply and heating facility 60a (heat demand facility) may also be regulated by adjusting the opening of the heat demand facility inlet valve 52. In this case, the opening of the heat demand facility inlet valve 52 is changed in the opposite direction to the direction in which the opening of the low-pressure turbine inlet valve 55 is changed. Specifically, in the above control, when the opening of the low-pressure turbine inlet valve 55 is reduced, an operation is performed to increase the opening of the heat demand facility inlet valve 52. This is because the exhaust steam discharged from the intermediate-pressure turbine 40b (first steam turbine) flows into either the low-pressure turbine 40c (second steam turbine) or the district hot water supply and heating plant 60a (heat demand facility), and therefore, if the amount of exhaust steam supplied to the district hot water supply and heating plant 60a (heat demand facility) is increased, the amount of exhaust steam supplied to the low-pressure turbine 40c (second steam turbine) will decrease, and if the amount of exhaust steam supplied to the district hot water supply and heating plant 60a (heat demand facility) is decreased, the amount of exhaust steam supplied to the low-pressure turbine 40c (second steam turbine) will increase. Therefore, the heat demand facility inlet valve 52 and the low-pressure turbine inlet valve 55 each constitute exhaust steam supply amount adjustment members for adjusting the amount of exhaust steam supplied to the low-pressure turbine 40c (second steam turbine).

[0047] Next, the above-mentioned control of the exhaust steam supply amount adjustment member for satisfying the heat demand of the district hot water supply / heating facility 60a (heat demand facility) when the heat demand changes will be described. As shown in Fig. 5, the heat supply amount control device 501 further includes an adjustment signal generation unit 522 that uses a heat demand signal to generate an adjustment signal for adjusting the amount of exhaust steam supplied to the low-pressure turbine 40c (second steam turbine), and an adjustment signal transmission unit 523 that transmits the adjustment signal to the exhaust steam supply amount adjustment member (heat demand facility inlet valve 52 or low-pressure turbine inlet valve 55). The adjustment signal generation unit 522 is electrically connected to the receiving unit 511, and the adjustment signal generation unit 522 is electrically connected to the adjustment signal transmission unit 523.

[0048] The adjustment signal transmission unit 523 is electrically connected to a drive unit of the heat demand facility inlet valve 52 or the low-pressure turbine inlet valve 55 (exhaust steam supply amount adjustment member) via an adjustment signal line 504a or 504b to transmit an adjustment signal to a drive unit (not shown) for controlling the aperture of the heat demand facility inlet valve 52 or the low-pressure turbine inlet valve 55 (exhaust steam supply amount adjustment member). The adjustment signal transmission unit 523 is also electrically connected to a drive unit of the on-off valve 53 via an on-off control signal line 505 to transmit an on-off control signal for opening and closing the on-off valve 53 to the drive unit (not shown) of the on-off valve 53. Note that when the transmission and reception of the adjustment signal between the adjustment signal transmission unit 523 and the heat demand facility inlet valve 52 or the low-pressure turbine inlet valve 55 (exhaust steam supply amount adjustment member) and / or the transmission and reception of the on-off control signal between the adjustment signal transmission unit 523 and the on-off valve 53 are performed by wireless communication, either or both of the adjustment signal line 504a or 504b and the on-off control signal line 505 can be omitted.

[0049] As described above, when the opening degree of the heat demand equipment inlet valve 52 or the low-pressure turbine inlet valve 55 (exhaust steam supply amount adjustment component) is adjusted to supply the district hot water supply and heating equipment 60a (heat demand equipment) with a heat amount corresponding to a wide range of heat demand of the district hot water supply and heating equipment 60a (heat demand equipment), the adjustment signal generating unit 522 uses the heat demand signal received by the receiving unit 511 to generate an adjustment signal for adjusting the amount of exhaust steam supplied to the low-pressure turbine 40c (second steam turbine). For example, the adjustment signal generating unit 522 may be previously configured with a map showing the relationship between the aperture of the heat demand facility inlet valve 52 or the low-pressure turbine inlet valve 55 (exhaust steam supply rate adjusting member) and the amount of exhaust steam supplied to the low-pressure turbine 40c (second steam turbine), as well as a map showing the relationship between the amount of change in the amount of exhaust steam supplied to the district hot water supply and heating facility 60a (heat demand facility) and the amount of change in heat demand of the district hot water supply and heating facility 60a (heat demand facility), and the adjustment signal can be generated by determining the aperture of the heat demand facility inlet valve 52 or the low-pressure turbine inlet valve 55 (exhaust steam supply rate adjusting member) based on these maps. The adjustment signal transmitting unit 523 transmits the adjustment control signal generated by the adjustment signal generating unit 522 to a drive unit for the heat demand facility inlet valve 52 or the low-pressure turbine inlet valve 55 (exhaust steam supply rate adjusting member). The drive unit of the heat demand facility inlet valve 52 or the low-pressure turbine inlet valve 55 (exhaust steam supply amount adjustment member) adjusts the opening of the heat demand facility inlet valve 52 or the low-pressure turbine inlet valve 55 (exhaust steam supply amount adjustment member) to an opening amount based on the adjustment signal, thereby changing the amount of exhaust steam supplied to the low-pressure turbine 40c (second steam turbine), and enabling the supply of an amount of exhaust steam to the district hot water supply and heating facility 60a (heat demand facility) according to the heat demand of the district hot water supply and heating facility 60a (heat demand facility).

[0050] When the heat demand of the district hot water supply and heating facility 60a (heat demand facility) is low, an adjustment signal is generated to minimize the opening of the heat demand facility inlet valve 52 or an adjustment signal to maximize the opening of the low-pressure turbine inlet valve 55. Alternatively, the adjustment signal generation unit 522 may generate an opening / closing control signal to close the opening / closing valve 53, and the adjustment signal transmission unit 523 may transmit this opening / closing control signal to the opening / closing valve 53, thereby closing the opening / closing valve 53 in accordance with the opening / closing control signal. When the heat demand of the district hot water supply and heating facility 60a increases, an adjustment signal is generated to increase the opening of the heat demand facility inlet valve 52 or an adjustment signal to decrease the opening of the low-pressure turbine inlet valve 55. This increases the amount of exhaust steam supplied to the district hot water supply and heating facility 60a (heat demand facility), making it possible to respond to the increase in heat demand of the district hot water supply and heating facility 60a (heat demand facility). Depending on the heat demand of the district hot water supply and heating system 60a (heat demand system), an adjustment signal is generated to reduce the opening of the low-pressure turbine inlet valve 55 to zero, i.e., to fully close the low-pressure turbine inlet valve 55. As a result, all of the exhaust steam is supplied to the district hot water supply and heating system 60a (heat demand system). However, if this does not meet the heat demand of the district hot water supply and heating system 60a (heat demand system), the opening or flow area of ​​the pressure control valve 50a (pressure reduction member) is adjusted using the control described above. If the heat demand of the district hot water supply and heating system 60a (heat demand system) decreases, an adjustment signal is generated to reduce the opening of the heat demand system inlet valve 52 or an adjustment signal to increase the opening of the low-pressure turbine inlet valve 55. This reduces the amount of exhaust steam supplied to the district hot water supply and heating system 60a, allowing the decrease in heat demand of the district hot water supply and heating system 60a (heat demand system) to be met.

[0051] The above-described control based on the heat demand of the district hot water supply and heating system 60a (heat demand facility) can also be applied to a configuration in which the second steam is not supplied to the district hot water supply and heating system 60a (heat demand facility). This configuration can be realized, for example, by removing the components for generating the second steam (the low-pressure economizer 201, the low-pressure evaporator 202, and the low-pressure superheater 203 (see FIG. 2)) from the heat recovery system 30, or by relocating the on-off valve 53 provided in the exhaust steam line 51 to the second steam line 32 and closing the on-off valve 53. Even in this configuration, the pressure expansion ratio of the intermediate-pressure turbine 40b (first steam turbine) is reduced by adjusting the aperture or flow path area of ​​the pressure regulating valve 50a (pressure reduction member), thereby reducing the pressure of the exhaust steam, and thereby reducing the output of the intermediate-pressure turbine 40b (first steam turbine). This increases the temperature of the exhaust steam, making it possible to increase the amount of heat supplied to the district hot water supply and heating facility 60a (heat demand facility), and therefore it is possible to supply a sufficient amount of heat to the district hot water supply and heating facility 60a (heat demand facility). Also, in this configuration, the amount of exhaust steam supplied to the low-pressure turbine 40c (second steam turbine) is adjusted to adjust the amount of exhaust steam supplied to the district hot water supply and heating facility 60a (heat demand facility), so it is possible to supply a sufficient amount of heat to the district hot water supply and heating facility 60a (heat demand facility).

[0052] <Modifications of the Pressure Dropping Member> In the first embodiment, the pressure-reducing member 50 is a pressure regulating valve 50a, but this is not intended to be limiting. Below, several modified examples of the pressure-reducing member 50 are given. Note that the modified examples given below are merely examples, and are not intended to limit the form of the pressure-reducing member 50 to these examples.

[0053] As shown in FIG. 6 , the pressure reduction member 50 may be configured to include multiple branch lines 56 arranged in parallel with one another and an on-off valve 57 provided in each branch line 56. By opening and closing each on-off valve 57, the number of branch lines 56 through which the exhaust steam flows can be changed, thereby changing the pressure loss of the exhaust steam caused by the pressure reduction member 50, thereby adjusting the amount of pressure loss of the exhaust steam. Specifically, all on-off valves 57 are opened to minimize the amount of pressure loss, and the number of on-off valves 57 that are closed is increased to increase the amount of pressure loss of the exhaust steam. Closing more on-off valves 57 reduces the number of branch lines 56 through which the exhaust steam flows. This reduces the flow area of ​​the pressure reduction member 50, increasing the pressure loss of the exhaust steam caused by the pressure reduction member 50, thereby increasing the amount of pressure loss of the exhaust steam. The number of branch lines 56 can be changed as desired.

[0054] 7 , the pressure reduction member 50 may include a first line 64 branching from the exhaust steam line 51 and having multiple turn-backs; a second line 65 branching from the exhaust steam line 51 downstream of the first line 64; multiple connecting lines 66 connected to the first line 64 and the second line 65, arranged in parallel; and an on-off valve 67 provided on each connecting line 66. Opening any one of the on-off valves 67 provided on each connecting line 66 changes the distance the exhaust steam travels through the first line 64, any of the connecting lines 66, and the second line 65, thereby changing the pressure loss of the exhaust steam caused by the pressure reduction member 50, thereby adjusting the amount of pressure reduction of the exhaust steam. Specifically, to minimize the amount of pressure reduction, an on-off valve 67a provided on a connecting line 66a connecting the branch points where the first line 64 and the second line 65 branch from the exhaust steam line 51 is opened. To maximize the amount of pressure drop in the exhaust steam, the on-off valve 67b provided in the connecting line 66b farthest from the connecting line 66a is opened. The number of connecting lines 66 can be changed as desired. The second line 65 may have multiple turn-back sections, or both the first line 64 and the second line 65 may have multiple turn-back sections. The greater the number of turn-back sections or the longer each turn-back section is, the greater the difference in pressure loss caused by changing the on-off valve 67 to be opened, and therefore the range of pressure drop that can be adjusted by the pressure-reduction member 50 can be widened.

[0055] As shown in Figure 8, the pressure reduction member 50 may be configured to change the number of orifices 75 arranged in series in the exhaust steam line 51. A case 76 capable of accommodating the orifices 75 may be provided in the exhaust steam line 51 as a portion into which the orifices 75 are inserted. The pressure reduction member 50 may also be configured so that the orifices 75 can be added or removed manually or by a hydraulic cylinder or the like. In this pressure reduction member 50, the number of orifices 75 is set to zero to minimize the amount of pressure drop, orifices 75 are added to increase the amount of pressure drop, and orifices 75 are removed to decrease the amount of pressure drop.

[0056] The pressure reduction member 50 having the configuration shown in Figures 6 to 8 is provided in the exhaust steam line 51 and reduces the pressure of the exhaust steam discharged from the intermediate-pressure turbine 40b. However, the pressure reduction member 50 is not limited to this configuration, and may also reduce the pressure of the exhaust steam after driving the intermediate-pressure turbine 40b and before being discharged from the intermediate-pressure turbine 40b. Two examples of the pressure reduction member 50 having this configuration will be described below.

[0057] 9, the pressure reduction member 50 may be a louver 50b provided downstream of the final stage stator vanes 45 and rotor blades 46 in the casing 44 of the intermediate-pressure turbine 40b. The louver 50b has a configuration in which a plurality of blade-like members 48 are provided in parallel on a shaft portion 47, and the angle of the blade-like members 48 can be changed to increase or decrease the flow path area of ​​the exhaust steam passing through the louver 50b after driving the intermediate-pressure turbine 40b. The louver 50b can adjust the amount of pressure reduction of the exhaust steam by changing the angle of the blade-like members 48.

[0058] As shown in FIG. 10 , the pressure reduction member 50 may include two disks 58, 59 located downstream of the final stage stator vanes 45 and rotor blades 46 within the casing 44 of the intermediate-pressure turbine 40b. As shown in FIG. 11 , the disks 58, 59 have the same configuration, and holes 58b, 59b of the same shape are provided around holes 58a, 59a, through which the rotating shaft of the intermediate-pressure turbine 40b is inserted, at equal intervals along the circumferential direction of the holes 58a, 59a. Rotating either one of the disks 58, 59 changes the overlapping area between the holes 58a and 59a. The overlapping area between the holes 58a and 59a forms the flow path for exhaust steam after driving the intermediate-pressure turbine 40b. Therefore, rotating either one of the disks 58, 59 changes the flow path area for the exhaust steam, thereby adjusting the amount of pressure reduction of the exhaust steam.

[0059] <Modification of the heat utilization system according to the first embodiment of the present disclosure> In the first embodiment, the pressure regulating valve 62 is described as a single valve, but this is not limiting. Like the pressure reducing member 50, the pressure regulating valve 62 may have the same configuration as any of the modified pressure reducing member 50 configurations shown in Figures 2 to 4.

[0060] In the first embodiment, the source of the heated fluid is the gas turbine 20, but this is not limiting. Any type of source can be used as the source of the heated fluid as long as it emits a fluid at a temperature that can evaporate water into steam by heat exchange with water in the heat recovery device 30. For example, a boiler, a gas engine, a solid oxide fuel cell, or the like can be used as the source of the heated fluid, and their exhaust gases can be used as the heated fluid. Other examples of combinations of the heated fluid and the source of the discharged fluid include a reactor and a product of an exothermic reaction in a chemical plant, a waste incinerator and combustion gas, a solar-powered heating device and a heat transfer gas, a geothermal-powered heating device and a heat transfer gas, and a nuclear reactor and a heat transfer gas. Examples of the heat transfer gas that can be used include helium, argon, carbon dioxide, and nitrogen.

[0061] (Embodiment 2) Next, a heat utilization system according to embodiment 2 will be described. The heat utilization system according to embodiment 2 is different from embodiment 1 in that the heat demand facility 60 is changed to a facility (carbon dioxide recovery device) that recovers carbon dioxide from the exhaust gas of the gas turbine 20. In embodiment 2, the same components as those in embodiment 1 are given the same reference numerals, and detailed descriptions thereof will be omitted.

[0062] <Configuration of heat utilization system according to embodiment 2 of the present disclosure> As shown in FIG. 12 , in a heat utilization system 1 according to a second embodiment of the present disclosure, exhaust gas discharged from a steelmaking facility 2 is used as fuel to be combusted in a combustor 22 of a gas turbine 20. The steelmaking facility 2 has a melter-gasifier 3, which produces steel using coal and iron ore as raw materials. Therefore, the exhaust gas discharged from the melter-gasifier 3 contains combustible components (e.g., carbon monoxide) and carbon dioxide. A fuel supply line 12 is connected to the melter-gasifier 3, and the fuel supply line 12 may be provided with a compressor 25 for pressurizing the exhaust gas discharged from the melter-gasifier 3. A nitrogen supply line 24 may also be connected to the fuel supply line 12. The calorific value of the fuel in the combustor 22 can be adjusted by mixing nitrogen supplied from the nitrogen supply line 24 with the fuel flowing through the fuel supply line 12.

[0063] Although the other configurations of the second embodiment may be the same as those of the first embodiment, the second embodiment is configured by partially modifying the configuration of the first embodiment as described below. In the heat utilization system 1 according to the second embodiment of the present disclosure, the steam turbine 40 only has a high-pressure turbine 40a. Therefore, in the second embodiment, the high-pressure turbine 40a constitutes the first steam turbine, and there is no second steam turbine. An exhaust steam line 51 is provided to connect the high-pressure turbine 40a to the heat demand facility 60. In addition, in the heat recovery device 30, water and exhaust gas exchange heat, causing the water to evaporate and generate two types of steam with different pressures. As described below, the higher-pressure steam is supplied to the high-pressure turbine 40a to drive it, and therefore the higher-pressure steam corresponds to the first steam. As in the first embodiment, the lower-pressure steam corresponds to the second steam.

[0064] The heat demand facility 60 is a carbon dioxide recovery unit 60b for recovering carbon dioxide from the exhaust gas discharged from the gas turbine 20, specifically, from the exhaust gas after heat exchange with water in the heat recovery unit 30. The carbon dioxide recovery unit 60b includes a cooling tower 100 for cooling the exhaust gas flowing out from the heat recovery unit 30, an absorption tower 101 for causing an absorption liquid to absorb the carbon dioxide contained in the exhaust gas cooled in the cooling tower 100, a regeneration tower 102 for dissipating the carbon dioxide by heating the absorption liquid that has absorbed the carbon dioxide in the absorption tower 101, and a reboiler 103 for heating the absorption liquid in the regeneration tower 102. The exhaust gas line 29 is connected to the cooling tower 100. Note that the cooling tower 100 is not an essential component of the carbon dioxide recovery unit 60b, and the cooling tower 100 may be omitted if the temperature of the exhaust gas flowing out from the heat recovery unit 30 is sufficiently low and the concentrations of solid components such as sulfur oxides and dust contained in the exhaust gas are sufficiently low. When the carbon dioxide recovery unit 60b does not include the cooling tower 100, the heat recovery unit 30 and the absorption tower 101 are communicated with each other via an exhaust gas line 29.

[0065] One end of the exhaust steam line 51 is connected to the high-pressure turbine 40a, and the other end is connected to the reboiler 103, thereby connecting the high-pressure turbine 40a and the reboiler 103. The heat recovery device 30 and the reboiler 103 are also connected via a water supply line 104. The water supply line 104 is provided with a pressure regulating valve 62 and a water feed pump 105 provided downstream of the pressure regulating valve 62.

[0066] The absorption tower 101 and the regeneration tower 102 are communicated with each other through a rich absorbent line 110 that connects the bottom of the absorption tower 101 to a position above the bottom of the regeneration tower 102, and a lean absorbent line 111 that connects the bottom of the regeneration tower 102 to a position above the bottom of the absorption tower 101. As will be described later, a rich absorbent that is an absorbent containing a large amount of carbon dioxide flows through the rich absorbent line 110, and a lean absorbent that is an absorbent that has stripped carbon dioxide from the rich absorbent and has a carbon dioxide content relatively lower than that of the rich absorbent flows through the lean absorbent line 111. A heat exchanger 112 that exchanges heat between the rich absorbent flowing through the rich absorbent line 110 and the lean absorbent flowing through the lean absorbent line 111 is provided in the rich absorbent line 110. A rich absorbent pump 113 is provided in the rich absorbent line 110 between the absorption tower 101 and the heat exchanger 112. The lean absorbent line 111 is provided with a lean absorbent pump 114 between the regenerator 102 and the heat exchanger 112 .

[0067] An exhaust line 122 is connected to the top of the absorption tower 101 to release the gas in the absorption tower 101 into the atmosphere. The regeneration tower 102 is provided with a circulation line 115 through which the absorbing liquid in the regeneration tower 102 is circulated so that the absorbing liquid is extracted from the bottom of the regeneration tower 102 and returned to the regeneration tower 102. The circulation line 115 is provided to pass through a reboiler 103. An outlet line 120 is connected to the top of the regeneration tower 102 to allow the gas in the regeneration tower 102, i.e., the gas containing carbon dioxide stripped from the absorbing liquid, to flow out from the regeneration tower 102. The outlet line 120 may be provided with a booster 121 to pressurize the gas.

[0068] Although details will be described later, in the second embodiment, the absorption liquid is heated by heat exchange between the mixed steam of the exhaust steam and the second steam discharged from the high-pressure turbine 40a and the absorption liquid in the reboiler 103 of the carbon dioxide recovery unit 60b, which is the heat demanding facility 60. Therefore, the reboiler 103 corresponds to a heat exchange mechanism that heats the absorption liquid, which is the heated body.

[0069] <Operation of the heat utilization system according to the second embodiment of the present disclosure (heat utilization method)> Next, the operation of the heat utilization system 1 according to the second embodiment of the present disclosure will be described. Due to the iron-making operation in the iron-making facility 2, exhaust gas is discharged from the melter-gasifier 3. The exhaust gas discharged from the melter-gasifier 3 is supplied as fuel to the combustor 22 of the gas turbine 20 via the fuel supply line 12. If a compressor 25 is provided in the fuel supply line 12, the exhaust gas is pressurized by the compressor 25 and then supplied to the combustor 22. The operation of the gas turbine 20 and the power generation device 26 is the same as in the first embodiment.

[0070] In the heat recovery system 30, the exhaust gas of the gas turbine 20 is cooled by heat exchange with water, as in the first embodiment. The cooled exhaust gas flows through the exhaust gas line 29 and flows into the cooling tower 100 of the carbon dioxide recovery system 60b. If the carbon dioxide recovery system 60b does not have a cooling tower 100, the exhaust gas flows into the absorption tower 101.

[0071] The water heated by heat exchange with the exhaust gas in the heat recovery unit 30 flows out of the heat recovery unit 30 as first steam and second steam having different pressures. The first steam is supplied to the high-pressure turbine 40a via the steam supply line 31 and drives the high-pressure turbine 40a. The high-pressure turbine 40a drives the power generation unit 41 to generate electricity. Meanwhile, the second steam flows through the second steam line 32. The exhaust steam discharged from the high-pressure turbine 40a after driving the high-pressure turbine 40a flows through the exhaust steam line 51, where it mixes with the second steam that has flowed through the second steam line 32, and flows into the reboiler 103 of the carbon dioxide recovery unit 60b.

[0072] As will be described later, the mixed steam of the exhaust steam and the second steam that has flowed into the reboiler 103 is cooled by heat exchange with the lean absorption liquid circulating through the circulation line 115. At this time, the pressure of the mixed fluid in the reboiler 103 can be adjusted by the pressure regulating valve 62. As a result, by maintaining the pressure inside the reboiler 103 at a sufficiently high level, a sufficient steam density and a sufficient heat transfer coefficient can be obtained, making it possible to provide the required amount of heat and further condensing the steam at a temperature required in the reboiler 103. The mixed steam that has exchanged heat with the lean absorption liquid in the reboiler 103 condenses into water, which is circulated through the water supply line 104 by the feed water pump 105 and then supplied to the heat recovery device 30, where it exchanges heat with the exhaust gas.

[0073] As described above, the exhaust gas that has flowed into the cooling tower 100 is cooled as it rises within the cooling tower 100 by coming into gas-liquid contact with the cooling water that falls within the cooling tower 100. If the exhaust gas contains sulfur oxides, solid components, etc., the sulfur oxides, solid components, etc. are captured in the cooling water through gas-liquid contact between the exhaust gas and the cooling water, and the sulfur oxides, solid components, etc. are removed from the exhaust gas.

[0074] The flue gas flowing out from the cooling tower 100 flows into the absorption tower 101. In the absorption tower 101, the flue gas rises and the lean absorbing liquid falls, so that the flue gas and the lean absorbing liquid come into gas-liquid contact, and the carbon dioxide contained in the flue gas is absorbed by the lean absorbing liquid. By absorbing the carbon dioxide, the lean absorbing liquid becomes a rich absorbing liquid and accumulates at the bottom of the absorption tower 101. By this operation, at least a portion of the carbon dioxide is removed from the flue gas, and the flue gas with a reduced carbon dioxide concentration flows out from the top of the absorption tower 101 and is released into the atmosphere via an exhaust line 122. Note that the exhaust line 122 may be connected to another facility, for example, a chimney, so that the flue gas with a reduced carbon dioxide concentration may be released via the chimney.

[0075] The rich absorbent in the absorption tower 101 is extracted from the bottom of the absorption tower 101 by the rich absorbent pump 113 and circulates through the rich absorbent line 110. The rich absorbent circulating through the rich absorbent line 110 is heated by heat exchange with the lean absorbent circulating through the lean absorbent line 111 in a heat exchanger 112 as described below, and then flows into the regenerator 102. The rich absorbent that has flowed into the regenerator 102 falls within the regenerator 102. As it falls within the regenerator 102, the rich absorbent is heated by contact with saturated steam that is generated in an operation described below and rises within the regenerator 102. As a result, at least a portion of the carbon dioxide is stripped from the rich absorbent, and the rich absorbent becomes lean absorbent and accumulates at the bottom of the regenerator 102. The lean absorbent in the regenerator 102 is extracted from the bottom of the regenerator 102, circulates through a circulation line 115, and is returned to the regenerator 102. When the lean absorbing liquid flows through the circulation line 115, the lean absorbing liquid is heated by heat exchange between the lean absorbing liquid and the mixed steam in the reboiler 103. As a result, the temperature of the lean absorbing liquid in the regenerator 102 rises, so that carbon dioxide is released from the lean absorbing liquid and water evaporates, and saturated steam containing mainly carbon dioxide and water vapor rises inside the regenerator 102. The circulation of the lean absorbing liquid through the circulation line 115 may be performed using a pump (not shown) provided in the circulation line 115, or may be performed using the density difference of the absorbing liquid without providing a pump.

[0076] The lean absorbent in the regenerator 102 is also extracted from the bottom of the regenerator 102 by a lean absorbent pump 114, and flows through a lean absorbent line 111. The lean absorbent flowing through the lean absorbent line 111 is cooled by heat exchange with the rich absorbent flowing through the rich absorbent line 110 in a heat exchanger 112. The lean absorbent cooled in the heat exchanger 112 flows into the absorber 101 and falls within the absorber 101, as described above.

[0077] The gas containing carbon dioxide stripped from the rich absorption liquid and the lean absorption liquid in the regeneration tower 102 flows out from the top of the regeneration tower 102 and flows through an outflow line 120. The gas flowing through the outflow line 120 is pressurized by a booster 121 and is supplied to a facility that consumes carbon dioxide or a facility that stores carbon dioxide (neither of which is shown).

[0078] Thus, in the second embodiment as in the first embodiment, not only the exhaust steam, which is the steam after driving the high-pressure turbine 40a, but also the second steam supplied from the heat recovery device 30 can be used as a heat source in the reboiler 103 of the carbon dioxide recovery device 60b, so that a sufficient amount of heat can be supplied to the reboiler 103.

[0079] In the carbon dioxide capture unit 60b, the amount of heat required by the reboiler 103 changes depending on the amount of carbon dioxide captured. In contrast, in the second embodiment, as in the first embodiment, the amount of heat supplied to the reboiler 103 can be controlled by changing the aperture of the pressure regulating valve 50a. The specific control method is the same as the control method described in the first embodiment. This makes it possible to control the amount of heat supplied to the carbon dioxide capture unit 60b based on the heat demand in the carbon dioxide capture unit 60b.

[0080] In the second embodiment, the carbon dioxide capture device 60b captures carbon dioxide from the exhaust gas discharged from the gas turbine 20. Therefore, even if the exhaust gas discharged from the steelmaking facility 2 is used as fuel for the gas turbine 20, it is possible to capture carbon dioxide generated in the steelmaking facility 2 and the gas turbine 20. The exhaust gas discharged from the steelmaking facility 2 contains carbon dioxide generated when iron ore is reduced using coal. In addition, when carbon monoxide and the like contained in the exhaust gas discharged from the steelmaking facility 2 is combusted in the combustor 22 of the gas turbine 20, further carbon dioxide is generated. Therefore, the exhaust gas discharged from the gas turbine 20 that uses the exhaust gas discharged from the steelmaking facility 2 as fuel contains a higher concentration of carbon dioxide than the exhaust gas discharged from a general gas turbine that uses fuel such as natural gas. Therefore, in order to capture carbon dioxide from the exhaust gas discharged from the gas turbine 20 that uses the exhaust gas discharged from the steelmaking facility 2 as fuel, a larger amount of heat is required than in order to capture carbon dioxide from the exhaust gas discharged from a general gas turbine. In contrast, by using the invention of the present disclosure, the amount of heat supplied to the carbon dioxide recovery device 60b can be increased, and even in the gas turbine 20 that uses the exhaust gas emitted from the steelmaking facility 2 as fuel, the carbon dioxide in the exhaust gas can be sufficiently recovered.

[0081] <Modification of the heat utilization system according to the second embodiment of the present disclosure> In the second embodiment, the heat for heating the lean absorption liquid in the reboiler 103 is heat recovered from the exhaust gas of the gas turbine 20 in the heat recovery unit 30, but the present invention is not limited to this heat. As shown in FIG. 13 , in the gas turbine 20, cooling air obtained by cooling a part of the compressed air is usually used to cool the inside of the combustor 22, the stationary blades 130, the turbine rotor 131, the moving blades 132 of the turbine rotor 131, etc. For this reason, the gas turbine 20 is provided with an air cooler 133 for cooling the compressed air. The air cooler 133 is a heat exchanger that exchanges heat between the compressed air and water supplied from the reboiler 103, and the compressed air is cooled and the water is heated by this heat exchange. The air cooler 133 may be configured to include, for example, a cooler 133a for preparing cooling air for cooling the inside of the combustor 22, a cooler 133b for preparing cooling air for cooling the stationary blades 130 of the turbine 23, and a cooler 133c for preparing cooling air for cooling the turbine rotor 131 and the moving blades 132 of the turbine rotor 131. The water (or steam) heated in the air cooler 133 may be supplied to the reboiler 103, or may be mixed with water that exchanges heat with the exhaust gas in the heat recovery device 30 (see FIG. 12 ), heated, and then supplied to the reboiler 103.

[0082] As described above, in the second embodiment, similar to the first embodiment, the steam turbine 40 may be configured to include an intermediate-pressure turbine 40b (see FIG. 1) and a low-pressure turbine 40c (see FIG. 1) in addition to the high-pressure turbine 40a, or the steam turbine 40 may be configured to include the high-pressure turbine 40a and the intermediate-pressure turbine 40b. In either of these configurations, similar to the first embodiment, the intermediate-pressure turbine 40b serves as the first steam turbine.

[0083] In the second embodiment, exhaust gas discharged from the steelmaking facility 2 is used as the fuel to be combusted in the combustor 22 of the gas turbine 20, but the present invention is not limited to this. Any fuel production facility that produces a gas containing combustible components (carbon monoxide, hydrocarbons, etc.) and carbon dioxide as exhaust gas or a product can be provided as a supply source for supplying fuel to the combustor 22 of the gas turbine 20. The steelmaking facility 2 of the second embodiment is an example of a fuel production facility. Other examples of fuel production facilities that can be used include a gasifier that gasifies coal or biomass fuel to obtain a gas containing hydrogen and carbon monoxide, and a reforming reaction device that adds steam to hydrocarbons and heats them to obtain a gas containing hydrogen and carbon monoxide.

[0084] (Embodiment 3) Next, a heat utilization system according to embodiment 3 will be described. In the heat utilization system according to embodiment 3, the heat demand facility 60 is changed to a vaporization facility used in chemical plants, etc., in comparison with embodiment 1. In embodiment 3, the same components as those in embodiment 1 are given the same reference numerals, and detailed descriptions thereof will be omitted.

[0085] <Configuration of heat utilization system according to embodiment 3 of the present disclosure> 14, in a heat utilization system 1 according to a third embodiment of the present disclosure, the heat-demanding facility 60 is a vaporization facility 60c for vaporizing a liquid substance (e.g., ammonia, methanol, etc.) that is a raw material used in a chemical plant or the like. The vaporization facility 60c includes a heat exchange mechanism 60c1 that exchanges heat between the liquid substance that is a heated object and first and second vapors. The vaporization facility 60c may include a tank 60c2 that stores the liquid substance and a pump 60c3 that supplies the liquid substance in the tank 60c2 to the heat exchange mechanism 60c1.

[0086] Although the other configurations of the third embodiment may be the same as those of the first embodiment, the third embodiment is configured by modifying the configuration of the first embodiment as described below. In the heat utilization system 1 according to the third embodiment of the present disclosure, the steam turbine 40 only has a high-pressure turbine 40a and an intermediate-pressure turbine 40b. The other configurations are the same as those of the first embodiment, except that the low-pressure turbine 40c (see FIG. 1) and the condenser 71 (see FIG. 1) that are present in the first embodiment are not present, and therefore the peripheral components thereof, the heat demand facility inlet valve 52 (see FIG. 1) and the on-off valve (see FIG. 1) are not present, and an exhaust line 61 connects the vaporization facility 60c and the heat recovery device 30. In the third embodiment, the intermediate-pressure turbine 40b corresponds to the first steam turbine as in the first embodiment, but unlike the first embodiment, there is no second steam turbine.

[0087] <Operation of the heat utilization system according to the third embodiment of the present disclosure (heat utilization method)> Next, the operation of the heat utilization system 1 according to the third embodiment of the present disclosure will be described. Except for the operation in which the heat of the first steam and the second steam is utilized in the vaporization equipment 60c, the operations of the first and third embodiments are the same, and therefore, only the operations that differ between the first and third embodiments will be described below.

[0088] A mixture of exhaust steam (first steam) discharged from the intermediate-pressure turbine 40b and second steam from the heat recovery unit 30 is supplied to the vaporization unit 60c. The mixed steam supplied to the vaporization unit 60c flows into the heat exchange mechanism 60c1 and exchanges heat with a liquid substance supplied from the tank 60c2 by the pump 60c3. The liquid substance is heated and vaporized by the heat exchange in the heat exchange mechanism 60c1, and is supplied to a reaction unit (not shown). Meanwhile, the mixed steam is cooled. During this heat exchange, the pressure of the mixed fluid in the heat exchange mechanism 60c1 can be adjusted by the pressure control valve 62. By maintaining a sufficiently high pressure within the heat exchange mechanism 60c1, a sufficient vapor density and heat transfer coefficient can be obtained, thereby providing the required amount of heat. Furthermore, the steam can be condensed at the required temperature in the heat exchange mechanism 60c1. Water condensed from the mixed steam is circulated through the discharge line 61 by the pump 63 and supplied to the heat recovery unit 30.

[0089] Thus, in the third embodiment as in the first embodiment, not only the exhaust steam, which is the steam after driving the intermediate-pressure turbine 40b, but also the second steam supplied from the heat recovery device 30 can be used as a heat source in the heat exchange mechanism 60c1 of the evaporation equipment 60c, so that a sufficient amount of heat can be supplied to the heat exchange mechanism 60c1.

[0090] In vaporization equipment 60c, the amount of heat required by heat exchange mechanism 60c1 changes depending on the amount of vaporization of the liquid substance. In contrast, in embodiment 3, as in embodiment 1, the amount of heat supplied to heat exchange mechanism 60c1 can be controlled by changing the opening degree of pressure regulating valve 50a. The specific control method is the same as the control method described in embodiment 1. In this way, the amount of heat supplied to vaporization equipment 60c can be controlled based on the heat demand in vaporization equipment 60c.

[0091] The contents described in each of the above embodiments can be understood, for example, as follows.

[0092] [1] A heat utilization system according to one aspect includes: a heat recovery device (30) that generates first steam and second steam having a pressure lower than that of the first steam from the water by heat exchange between a heating fluid and the water; an exhaust source (gas turbine 20) that exhausts the heated fluid; a first steam turbine (high-pressure turbine 40a or intermediate-pressure turbine 40b) driven by the first steam; a pressure reduction member (50) that reduces the pressure of exhaust steam, which is steam after driving the first steam turbine (40a or 40b); a heat demand facility (60) that utilizes heat of at least one of at least a part of the exhaust steam and the second steam; an exhaust steam line (51) connecting the first steam turbine (40a or 40b) and the heat demand facility (60); a second steam line (32) through which the second steam flows out from the heat recovery device (30); Equipped with The second vapor line (32) is connected to the exhaust vapor line (51) downstream of the pressure reduction element (50).

[0093] According to the heat utilization system of the present disclosure, not only the exhaust steam, which is the steam after driving the first steam turbine, but also the second steam supplied from the heat recovery device can be used as a heat source for the heat demand equipment, so that a sufficient amount of heat can be supplied to the heat demand equipment.

[0094] [2] A heat utilization system according to another aspect is the heat utilization system according to [1], The heat demand facility (60) includes a heat exchange mechanism (reboiler 103 / heat exchange mechanism 60c1) in which at least one of the exhaust steam and the second steam exchanges heat with the object to be heated, thereby heating the object to be heated.

[0095] With this configuration, it is possible to heat an object to be heated in the heat demand facility.

[0096] [3] A heat utilization system according to yet another aspect is the heat utilization system according to [2], The heat demand facility (60) is a vaporization facility (60c) for vaporizing the liquid substance to be heated.

[0097] With this configuration, the liquid substance can be vaporized in the heat demand facility.

[0098] [4] A heat utilization system according to yet another embodiment is a heat utilization system according to any one of [1] to [3], The plant includes a second steam turbine (low-pressure turbine 40c) driven by at least a portion of the exhaust steam.

[0099] With this configuration, when the heat demand in the heat demand equipment is small, exhaust steam that does not need to be used in the heat demand equipment can be used to drive the second steam turbine, thereby increasing the amount of power generation within the heat utilization system.

[0100] [5] A heat utilization system according to yet another embodiment is a heat utilization system according to any one of [1] to [4], The pressure reduction member (50) adjusts the amount of reduction in the pressure of the exhaust steam based on the heat demand in the heat demand facility (60).

[0101] With this configuration, when the pressure of the exhaust steam is reduced by the pressure reduction member, the output of the first steam turbine is reduced, and the temperature of the exhaust steam increases. Therefore, when the heat demand in the heat demanding facility increases, the amount of reduction in the exhaust steam pressure by the pressure reduction member can be adjusted so that the exhaust steam with an increased temperature can be supplied to the heat demanding facility, thereby making it possible to supply a sufficient amount of heat to the heat demanding facility based on the heat demand in the heat demanding facility.

[0102] [6] A heat utilization system according to yet another aspect is the heat utilization system according to [4], an exhaust steam supply amount adjustment member (heat demand facility inlet valve 52 / low-pressure turbine inlet valve 55) for adjusting the amount of exhaust steam supplied to the second steam turbine (40c); Based on the heat demand in the heat demand facility (60), the exhaust steam supply amount adjustment member (52 / 55) adjusts the amount of exhaust steam supplied to the second steam turbine (40c), thereby adjusting the amount of exhaust steam supplied to the heat demand facility (60).

[0103] With this configuration, by reducing the amount of exhaust steam supplied to the second steam turbine and increasing the amount of exhaust steam supplied to the heat-demanding facility, a sufficient amount of heat based on the heat demand in the heat-demanding facility can be supplied to the heat-demanding facility. Furthermore, when the heat demand in the heat-demanding facility is small, by increasing the amount of exhaust steam supplied to the second steam turbine, the exhaust steam that does not need to be used in the heat-demanding facility can be used to drive the second steam turbine, thereby increasing the amount of power generation in the heat utilization system.

[0104] [7] A heat utilization system according to yet another aspect is the heat utilization system according to [4], an exhaust steam supply amount adjustment member (52 / 55) for adjusting the amount of exhaust steam supplied to the second steam turbine (40c); Based on the heat demand in the heat demand facility (60), the exhaust steam supply amount adjustment member (52 / 55) stops the supply of the exhaust steam to the second steam turbine (40c), and the pressure reduction member (50) adjusts the amount of reduction in the pressure of the exhaust steam.

[0105] With this configuration, if it is not possible to supply the heat demand equipment with an amount of heat equivalent to the heat demand in the heat demand equipment without supplying the exhaust steam to the second steam turbine, the amount of reduction in the pressure of the exhaust steam can be adjusted using a pressure reduction member, so that exhaust steam with an increased temperature can be supplied to the heat demand equipment, thereby making it possible to supply the heat demand equipment with a sufficient amount of heat based on the heat demand in the heat demand equipment.

[0106] [8] A heat utilization system according to yet another aspect is the heat utilization system according to [2], the heat demand facility (60) is a carbon dioxide recovery unit (60b) for recovering carbon dioxide contained in the heating fluid; The carbon dioxide recovery device (60b) an absorption tower (101) for bringing the heating fluid that has been heat exchanged with the water in the heat recovery device (30) into contact with an absorbing liquid, thereby absorbing carbon dioxide into the absorbing liquid; a regeneration tower (102) for heating the absorbing solution that has absorbed carbon dioxide in the absorption tower (101) to release carbon dioxide from the absorbing solution; Including, The heat exchange mechanism is a reboiler (103) for heating the absorption liquid in the regeneration tower (102) as the heated body.

[0107] According to this configuration, the carbon dioxide recovery device heats the absorbing liquid in the regeneration tower to cause the carbon dioxide to dissipate from the absorption tower, thereby making it possible to recover the carbon dioxide contained in the heated fluid.

[0108] [9] A heat utilization system according to yet another aspect is the heat utilization system according to [8], the emission source is a gas turbine (20); The gas turbine (20) a compressor (21) for compressing air; a combustor (22) that burns fuel using the compressed air compressed by the compressor (21); a turbine (23) driven by combustion gas generated by burning the fuel in the combustor (22); an air cooler (133) that cools a portion of the compressed air by heat exchange between a portion of the compressed air and a portion of the water; Equipped with.

[0109] With this configuration, the heat removed from the compressed air to adjust the temperature of the cooling air that cools the combustor and turbine of the gas turbine is used to heat the absorption liquid, thereby increasing the amount of heat available in the carbon dioxide recovery system.

[0110]

[10] A heat utilization system according to yet another aspect is the heat utilization system according to [8], the emission source is a gas turbine (20); The gas turbine (20) a compressor (21) for compressing air; a combustor (22) that burns fuel using the compressed air compressed by the compressor (21); a turbine (23) driven by combustion gas generated by burning the fuel in the combustor (22); Equipped with The heat utilization system (1) includes a fuel production facility (steel manufacturing facility 2) that produces a gas containing combustible components and carbon dioxide as an exhaust gas or a product, The fuel production facility (2) is configured to supply the gas as the fuel to the combustor (22).

[0111] With this configuration, the carbon dioxide capture device captures carbon dioxide from the gas discharged from the gas turbine, so even if gas supplied from the fuel production facility is used as fuel for the gas turbine, it is possible to capture carbon dioxide generated in the fuel production facility and the gas turbine.

[0112]

[11] A heat utilization system according to one aspect includes: a heat recovery device (30) that generates first steam from water by heat exchange between a heating fluid and the water; an exhaust source (gas turbine 20) that exhausts the heated fluid; a first steam turbine (high-pressure turbine 40a or intermediate-pressure turbine 40b) driven by the first steam; a pressure reduction member (50) that reduces the pressure of exhaust steam, which is steam after driving the first steam turbine (40a or 40b); a heat demand facility (60) that utilizes heat from at least a portion of the exhaust steam downstream of the pressure reduction member (50); Equipped with The pressure reduction element (50) adjusts the amount of pressure reduction of the exhaust steam based on the heat demand in the heat demand facility (60).

[0113] According to the heat utilization system of the present disclosure, increasing the pressure drop of the exhaust steam increases the pressure at the inlet of the pressure reduction member, i.e., the outlet of the first steam turbine, decreasing the pressure expansion ratio of the first steam turbine and decreasing the output of the first steam turbine. This increases the temperature of the exhaust steam, making it possible to increase the amount of heat supplied to the heat demanding facility, and therefore to supply a sufficient amount of heat to the heat demanding facility.

[0114]

[12] A heat utilization system according to another aspect is the heat utilization system according to

[11] , As the heat demand in the heat demand facility (60) increases, the amount of pressure reduction by the pressure reduction member (50) is increased.

[0115] With this configuration, when the heat demand in the heat demand facility increases, the temperature of the exhaust steam increases by increasing the amount of pressure reduction of the exhaust steam using the pressure reduction member, so that the amount of heat supplied to the heat demand facility can be increased, and a sufficient amount of heat can be supplied to the heat demand facility.

[0116]

[13] A heat utilization system according to yet another embodiment is the heat utilization system according to

[11] or

[12] , As the heat demand in the heat demand facility (60) increases, the flow area of ​​the exhaust steam in the pressure reduction member (50) is reduced.

[0117] With this configuration, when the heat demand in the heat demand facility increases, the amount of pressure drop in the exhaust steam increases by reducing the flow path area of ​​the exhaust steam in the pressure reduction member, and the temperature of the exhaust steam rises, so that the amount of heat supplied to the heat demand facility can be increased, and a sufficient amount of heat can be supplied to the heat demand facility.

[0118]

[14] A heat utilization system according to yet another embodiment is a heat utilization system according to any one of

[11] to

[13] , a second steam turbine (low-pressure turbine 40c) driven by at least a portion of the exhaust steam; an exhaust steam supply amount adjustment member (heat demand facility inlet valve 52 / low-pressure turbine inlet valve 55) for adjusting the amount of exhaust steam supplied to the second steam turbine (40c); Equipped with The exhaust steam supply amount adjustment member (52 / 55) adjusts the amount of exhaust steam supplied to the second steam turbine (40c) based on the heat demand in the heat demand facility (60), thereby adjusting the amount of exhaust steam supplied to the heat demand facility (60).

[0119] With this configuration, by reducing the amount of exhaust steam supplied to the second steam turbine and increasing the amount of exhaust steam supplied to the heat-demanding facility, a sufficient amount of heat based on the heat demand in the heat-demanding facility can be supplied to the heat-demanding facility. Furthermore, when the heat demand in the heat-demanding facility is small, by increasing the amount of exhaust steam supplied to the second steam turbine, the exhaust steam that does not need to be used in the heat-demanding facility can be used to drive the second steam turbine, thereby increasing the amount of power generation in the heat utilization system.

[0120]

[15] A heat utilization system according to yet another aspect is the heat utilization system according to

[14] , The amount of exhaust steam supplied to the heat demand facility (60) is adjusted while minimizing the amount of pressure drop across the pressure drop member (50).

[0121] With this configuration, the heat demand in the heat demand facility can be met without reducing the output of the first steam turbine.

[0122]

[16] A heat utilization system according to yet another aspect is the heat utilization system according to

[14] , Based on the heat demand in the heat demand facility (60), the exhaust steam supply amount adjustment member (52 / 55) stops the supply of the exhaust steam to the second steam turbine (40c), and the pressure reduction member (50) adjusts the amount of pressure reduction of the exhaust steam.

[0123] With this configuration, if the heat demand in the heat demand equipment cannot be met even if the entire amount of exhaust steam is supplied to the heat demand equipment, the pressure reduction element can be used to increase the amount of pressure reduction in the exhaust steam, thereby raising the temperature of the exhaust steam and increasing the amount of heat supplied to the heat demand equipment, thereby meeting the heat demand of the heat demand equipment.

[0124]

[17] A heat utilization system according to yet another aspect is the heat utilization system according to

[16] , As the heat demand in the heat demand facility (60) increases, the amount of pressure reduction by the pressure reduction member (50) is increased.

[0125] With this configuration, if the heat demand in the heat demand equipment increases while the entire amount of exhaust steam is being supplied to the heat demand equipment, the temperature of the exhaust steam increases by increasing the amount of pressure reduction of the exhaust steam using the pressure reduction member, so that the amount of heat supplied to the heat demand equipment can be increased and the heat demand in the heat demand equipment can be met.

[0126]

[18] A heat utilization system according to yet another aspect is the heat utilization system according to

[14] , Based on the heat demand in the heat demand facility (60), the exhaust steam supply amount adjustment member (52 / 55) stops the supply of the exhaust steam to the second steam turbine (40c) and adjusts the flow path area of ​​the exhaust steam in the pressure reduction member (50).

[0127] With this configuration, if the heat demand in the heat demand equipment cannot be met even if the entire amount of exhaust steam is supplied to the heat demand equipment, the flow path area of ​​the exhaust steam in the pressure reduction member can be reduced to increase the amount of pressure reduction of the exhaust steam, thereby raising the temperature of the exhaust steam and increasing the amount of heat supplied to the heat demand equipment, thereby meeting the heat demand in the heat demand equipment.

[0128]

[19] A heat utilization system according to yet another aspect is the heat utilization system according to

[18] , As the heat demand in the heat demand facility increases, the flow area of ​​the exhaust steam in the pressure reduction member is reduced.

[0129] With this configuration, if the heat demand in the heat demand equipment increases while the entire amount of exhaust steam is being supplied to the heat demand equipment, the temperature of the exhaust steam can be increased by reducing the flow path area of ​​the exhaust steam in the pressure reduction member and increasing the amount of pressure reduction of the exhaust steam, thereby increasing the amount of heat supplied to the heat demand equipment and satisfying the heat demand in the heat demand equipment.

[0130]

[20] A heat utilization system according to yet another aspect is the heat utilization system according to

[11] , A heat supply amount control device (501) is provided, The heat supply amount control device (501) a receiving unit (511) that receives a heat demand signal, which is a signal related to heat demand in the heat demand facility (60), from the heat demand facility; a control signal generator (512) that uses the heat demand signal to generate a control signal for controlling the amount of pressure reduction by the pressure reduction element (50); a control signal transmitter (513) for transmitting the control signal to the pressure reduction member (50); Equipped with.

[0131] With this configuration, the heat supply amount control device adjusts the amount of pressure reduction by the pressure reduction member based on the heat demand in the heat demanding facility, so that the amount of heat can be appropriately supplied to the heat demanding facility in accordance with the heat demand.

[0132]

[21] A heat utilization system according to yet another aspect is the heat utilization system according to

[20] , When the control signal generator (512) detects an increase in heat demand in the heat demand facility (60) based on the heat demand signal, it generates the control signal to increase the amount of pressure reduction by the pressure reduction member (50).

[0133] With this configuration, when the heat demand in the heat demand facility increases, the temperature of the exhaust steam increases by increasing the amount of pressure reduction of the exhaust steam using the pressure reduction member, so that the amount of heat supplied to the heat demand facility can be increased, and a sufficient amount of heat can be supplied to the heat demand facility.

[0134]

[22] A heat utilization system according to yet another embodiment is the heat utilization system according to

[20] or

[21] , When the control signal generating unit (512) detects an increase in heat demand in the heat demand facility (60) based on the heat demand signal, it generates the control signal to reduce a flow area of ​​the exhaust steam in the pressure reduction member (50).

[0135] With this configuration, when the heat demand in the heat demand facility increases, the amount of pressure drop in the exhaust steam increases by reducing the flow path area of ​​the exhaust steam in the pressure reduction member, and the temperature of the exhaust steam rises, so that the amount of heat supplied to the heat demand facility can be increased, and a sufficient amount of heat can be supplied to the heat demand facility.

[0136]

[23] A heat utilization system according to yet another embodiment is a heat utilization system according to any one of

[20] to

[22] , a second steam turbine (40c) driven by at least a portion of the exhaust steam; an exhaust steam supply amount adjustment member (52 / 55) for adjusting the amount of exhaust steam supplied to the second steam turbine (40c); Equipped with The heat supply amount control device (501) an adjustment signal generating unit (522) that generates an adjustment signal for adjusting a supply amount of the exhaust steam supplied to the second steam turbine (40c) by using the heat demand signal; an adjustment signal transmitting unit (523) for transmitting the adjustment signal to the exhaust steam supply amount adjusting member (52 / 55); Equipped with The exhaust steam supply amount adjustment member (52 / 55) adjusts the amount of exhaust steam supplied to the second steam turbine (40c) based on the adjustment signal.

[0137] With this configuration, by reducing the amount of exhaust steam supplied to the second steam turbine and increasing the amount of exhaust steam supplied to the heat-demanding facility, a sufficient amount of heat based on the heat demand in the heat-demanding facility can be supplied to the heat-demanding facility. Furthermore, when the heat demand in the heat-demanding facility is small, by increasing the amount of exhaust steam supplied to the second steam turbine, the exhaust steam that does not need to be used in the heat-demanding facility can be used to drive the second steam turbine, thereby increasing the amount of power generation in the heat utilization system.

[0138]

[24] A heat utilization system according to yet another aspect is the heat utilization system according to

[23] , The control signal generator (522) generates the control signal that minimizes the amount of pressure reduction caused by the pressure reduction member (50).

[0139] With this configuration, the heat demand in the heat demand facility can be met without reducing the output of the first steam turbine.

[0140]

[25] A heat utilization system according to yet another aspect is the heat utilization system according to

[23] , The adjustment signal generating unit (522) generates the adjustment signal to stop the supply of the exhaust steam to the second steam turbine (40c).

[0141] With this configuration, when the priority of supplying heat to the heat demanding equipment is higher than the amount of power generated in the heat utilization system, the second steam turbine can be stopped and the entire amount of exhaust steam can be supplied to the heat demanding equipment, thereby satisfying the heat demand in the heat demanding equipment with high priority.

[0142]

[26] A heat utilization system according to yet another aspect is the heat utilization system according to

[25] , When the control signal generator (522) detects an increase in heat demand in the heat demand facility (60) based on the heat demand signal, it generates the control signal for increasing the amount of pressure reduction by the pressure reduction member (50).

[0143] With this configuration, if the heat demand in the heat demand equipment cannot be met even if the entire amount of exhaust steam is supplied to the heat demand equipment, the pressure reduction element can be used to increase the amount of pressure reduction in the exhaust steam, thereby raising the temperature of the exhaust steam and increasing the amount of heat supplied to the heat demand equipment, thereby meeting the heat demand of the heat demand equipment.

[0144]

[27] A heat utilization system according to yet another aspect is the heat utilization system according to

[25] , When the control signal generating unit (522) detects an increase in heat demand in the heat demand facility (60) based on the heat demand signal, it generates the control signal to reduce a flow area of ​​the exhaust steam in the pressure reduction member (50).

[0145] With this configuration, if the heat demand in the heat demand equipment cannot be met even if the entire amount of exhaust steam is supplied to the heat demand equipment, the flow path area of ​​the exhaust steam in the pressure reduction member can be reduced to increase the amount of pressure reduction of the exhaust steam, thereby raising the temperature of the exhaust steam and increasing the amount of heat supplied to the heat demand equipment, thereby meeting the heat demand in the heat demand equipment.

[0146]

[28] A heat utilization method according to one aspect includes: Discharging a heated fluid from a discharge source (gas turbine 20); generating first steam from the water by heat exchange between the heating fluid and the water; driving a first steam turbine (high-pressure turbine 40a or intermediate-pressure turbine 40b) with the first steam; a step of reducing the pressure of exhaust steam, which is steam after driving the first steam turbine (40a or 40b); supplying the exhaust steam whose pressure has been reduced to a heat demand facility (60); Equipped with The step of reducing the pressure of the exhaust steam adjusts the amount of reduction in the pressure of the exhaust steam based on the heat demand in the heat demand facility (60).

[0147] According to the heat utilization method of the present disclosure, increasing the pressure drop of the exhaust steam increases the pressure at the inlet of the pressure reduction member, i.e., the outlet of the first steam turbine, decreasing the pressure expansion ratio of the first steam turbine and decreasing the output of the first steam turbine. This increases the temperature of the exhaust steam, making it possible to increase the amount of heat supplied to the heat-demanding facility, and thus ensure that a sufficient amount of heat can be supplied to the heat-demanding facility.

[0148]

[29] A heat utilization method according to another aspect is the heat utilization method according to

[28] , In the step of reducing the pressure of the exhaust steam, the amount of pressure reduction is increased as the heat demand in the heat demand facility (60) increases.

[0149] According to this method, when the heat demand in the heat demand facility increases, the temperature of the exhaust steam increases by increasing the amount of pressure reduction in the exhaust steam, thereby increasing the amount of heat supplied to the heat demand facility, and making it possible to supply a sufficient amount of heat to the heat demand facility.

[0150]

[30] A heat utilization method according to yet another embodiment is the heat utilization method according to

[28] or

[29] , The step of reducing the pressure of the exhaust steam includes reducing the pressure of the exhaust steam using a pressure reduction member (50); The step of reducing the pressure of the exhaust steam reduces a flow area of ​​the exhaust steam in the pressure reduction member (50) in response to an increase in heat demand in the heat demand facility (60).

[0151] According to this method, when the heat demand in the heat demand facility increases, the amount of pressure drop in the exhaust steam increases by reducing the flow path area of ​​the exhaust steam in the pressure reduction member, and the temperature of the exhaust steam rises, so that the amount of heat supplied to the heat demand facility can be increased, and a sufficient amount of heat can be supplied to the heat demand facility.

[0152]

[31] A heat utilization method according to yet another embodiment is any one of the heat utilization methods

[28] to

[30] , supplying a portion of the exhaust steam to a second steam turbine (40c) driven by the exhaust steam; adjusting the amount of exhaust steam supplied to the second steam turbine (40c) in accordance with heat demand in the heat demand facility (60); Equipped with.

[0153] According to this method, by reducing the amount of exhaust steam supplied to the second steam turbine and increasing the amount of exhaust steam supplied to the heat-demanding facility, a sufficient amount of heat based on the heat demand in the heat-demanding facility can be supplied to the heat-demanding facility. Furthermore, when the heat demand in the heat-demanding facility is small, by increasing the amount of exhaust steam supplied to the second steam turbine, the exhaust steam that does not need to be used in the heat-demanding facility can be used to drive the second steam turbine, thereby increasing the amount of power generation in the heat utilization system. [Explanation of symbols]

[0154] 1. Heat utilization system 2. Steelmaking facilities (fuel production facilities) 20 Gas turbine (emission source) 21 Compressor 22 Combustor 23 Turbine 30 Heat recovery device 32 Second Steam Line 33 Reheat steam supply line (No. 1 steam line) 40a High Pressure Turbine (No. 1 Steam Turbine) 40b Intermediate pressure turbine (No. 1 steam turbine) 40c low pressure turbine (second steam turbine) 50 Pressure reducing member 51 Exhaust steam line 52 Heat demand equipment inlet valve (exhaust steam supply amount adjustment component) 55 Low pressure turbine inlet valve (exhaust steam supply amount adjustment component) 60 Heat demand equipment 60b Carbon dioxide capture equipment 60c vaporizer 60c1 heat exchange mechanism 101 Absorption Tower 102 Regeneration Tower 103 Reboiler (heat exchange mechanism) 133 Air Cooler 204 First reheater (first steam generating section) 205 Second reheater (first steam generating section) 501 Heat supply control device 511 Receiving unit 512 control signal generation unit 513 Control signal transmitter 522 Adjustment signal generation section 523 Adjustment signal transmitter

Claims

1. a heat recovery device that generates first steam and second steam having a pressure lower than that of the first steam from the water by heat exchange between the heating fluid and water; a discharge source for discharging the heating fluid; a first steam turbine driven by the first steam; a pressure reducing member that reduces the pressure of exhaust steam that is steam after driving the first steam turbine; a heat demand facility that utilizes heat from at least one of at least a portion of the exhaust steam and the second steam; an exhaust steam line connecting the first steam turbine and the heat demand facility; a first steam line through which the first steam flows out from the heat recovery device; a second steam line through which the second steam flows out from the heat recovery device; Equipped with the second steam line is connected to the exhaust steam line downstream of the pressure reduction member; The heat recovery device is a first steam generating unit that generates the first steam; a second steam generating unit that generates the second steam; Equipped with an upstream end of the first steam line connected to the first steam generating section and a downstream end of the first steam line connected to the first steam turbine; The second steam line has an upstream end connected to the second steam generating unit and a downstream end connected to the exhaust steam line.

2. The heat utilization system according to claim 1 , wherein the heat demand facility includes a heat exchange mechanism that heats a heated object by heat exchange between at least one of the exhaust steam and the second steam and the heated object.

3. The heat utilization system according to claim 2 , wherein the heat demand facility is a vaporization facility for vaporizing the liquid substance that is the object to be heated.

4. The heat utilization system according to claim 1 or 2, further comprising a second steam turbine driven by at least a portion of the exhaust steam.

5. The heat utilization system according to claim 1 or 2, wherein the pressure reduction member adjusts the amount of reduction in pressure of the exhaust steam based on heat demand in the heat demand facility.

6. an exhaust steam supply amount adjustment member for adjusting the amount of exhaust steam supplied to the second steam turbine; 5. The heat utilization system of claim 4, wherein the exhaust steam supply amount adjustment member adjusts the amount of exhaust steam supplied to the second steam turbine based on the heat demand in the heat demand facility, thereby adjusting the amount of exhaust steam supplied to the heat demand facility.

7. an exhaust steam supply amount adjustment member for adjusting the amount of exhaust steam supplied to the second steam turbine; 5. The heat utilization system according to claim 4, wherein the exhaust steam supply amount adjustment member stops the supply of the exhaust steam to the second steam turbine and the pressure reduction member adjusts the amount of reduction in the pressure of the exhaust steam based on the heat demand in the heat demand facility.

8. the heat demand facility is a carbon dioxide recovery device for recovering carbon dioxide contained in the heating fluid, The carbon dioxide capture device an absorption tower that brings the heating fluid that has exchanged heat with the water in the heat recovery device into contact with an absorption liquid, thereby absorbing carbon dioxide into the absorption liquid; a regeneration tower that heats the absorption liquid that has absorbed carbon dioxide in the absorption tower and releases carbon dioxide from the absorption liquid; Including, The heat utilization system according to claim 2 , wherein the heat exchange mechanism is a reboiler for heating the absorption liquid in the regeneration tower as the heated body.

9. the emission source is a gas turbine; The gas turbine comprises: a compressor for compressing air; a combustor that burns fuel using the compressed air compressed by the compressor; a turbine driven by combustion gas generated by burning the fuel in the combustor; an air cooler that cools a portion of the compressed air by exchanging heat between a portion of the compressed air and a portion of the water; The heat utilization system according to claim 8 , comprising:

10. the emission source is a gas turbine; The gas turbine comprises: a compressor for compressing air; a combustor that burns fuel using the compressed air compressed by the compressor; a turbine driven by combustion gas generated by burning the fuel in the combustor; Equipped with The heat utilization system includes a fuel production facility that produces a gas containing a combustible component and carbon dioxide as an exhaust gas or a product, The heat utilization system according to claim 8 , wherein the fuel production facility is configured to supply the gas as the fuel to the combustor.

11. a heat recovery device that generates first steam from water by heat exchange between a heating fluid and the water; a discharge source for discharging the heating fluid; a first steam turbine driven by the first steam; a pressure reducing member that reduces the pressure of exhaust steam that is steam after driving the first steam turbine; a heat demand facility that utilizes heat from at least a portion of the exhaust steam downstream of the pressure reduction member; Equipped with the pressure reduction member is configured so that a pressure reduction amount of the exhaust steam increases as a flow path area of ​​the pressure reduction member decreases; The heat utilization system includes a pressure reduction member that adjusts the amount of pressure reduction of the exhaust steam based on heat demand in the heat demand facility.

12. The heat utilization system according to claim 11 , wherein the amount of pressure drop caused by the pressure drop member is increased as the heat demand in the heat demanding facility increases.

13. The heat utilization system according to claim 11 , wherein a flow area of ​​the exhaust steam in the pressure reduction member is reduced as the heat demand in the heat demand facility increases.

14. a second steam turbine driven by at least a portion of the exhaust steam; an exhaust steam supply amount adjustment member for adjusting the amount of exhaust steam supplied to the second steam turbine; Equipped with The heat utilization system according to any one of claims 11 to 13, wherein the exhaust steam supply amount adjustment member adjusts the amount of exhaust steam supplied to the second steam turbine based on the heat demand in the heat demand facility, thereby adjusting the amount of exhaust steam supplied to the heat demand facility.

15. The heat utilization system according to claim 14 , wherein the amount of exhaust steam supplied to the heat demanding facility is adjusted while minimizing the amount of pressure drop in the pressure reduction member.

16. 15. The heat utilization system according to claim 14, wherein the exhaust steam supply amount adjustment member stops the supply of the exhaust steam to the second steam turbine and the pressure reduction member adjusts the amount of pressure reduction of the exhaust steam based on heat demand in the heat demand facility.

17. The heat utilization system according to claim 16 , wherein the amount of pressure drop caused by the pressure drop member is increased as the heat demand in the heat demanding facility increases.

18. 15. The heat utilization system according to claim 14, wherein the exhaust steam supply amount adjustment member stops the supply of the exhaust steam to the second steam turbine and adjusts a flow path area of ​​the exhaust steam in the pressure reduction member based on heat demand in the heat demand facility.

19. The heat utilization system according to claim 18 , wherein a flow area of ​​the exhaust steam in the pressure reduction member is reduced as the heat demand in the heat demand facility increases.

20. A heat supply amount control device is provided, The heat supply amount control device is a receiving unit that receives a heat demand signal from the heat demand facility, the heat demand signal being a signal related to heat demand in the heat demand facility; a control signal generator that uses the heat demand signal to generate a control signal for controlling the amount of pressure reduction by the pressure reduction member; a control signal transmitter that transmits the control signal to the pressure reduction member; The heat utilization system according to claim 11 , comprising:

21. 21. The heat utilization system according to claim 20, wherein the control signal generator generates the control signal to increase the amount of pressure reduction by the pressure reduction member when an increase in heat demand in the heat demand facility is detected based on the heat demand signal.

22. 21. The heat utilization system according to claim 20, wherein the control signal generation unit generates the control signal to reduce a flow area of ​​the exhaust steam in the pressure reduction member when an increase in heat demand in the heat demand facility is detected based on the heat demand signal.

23. a second steam turbine driven by at least a portion of the exhaust steam; an exhaust steam supply amount adjustment member for adjusting the amount of exhaust steam supplied to the second steam turbine; Equipped with The heat supply amount control device is an adjustment signal generating unit that generates an adjustment signal for adjusting a supply amount of the exhaust steam supplied to the second steam turbine using the heat demand signal; an adjustment signal transmitting unit that transmits the adjustment signal to the exhaust steam supply amount adjusting member; Equipped with The heat utilization system according to any one of claims 20 to 22, wherein the exhaust steam supply amount adjustment member adjusts the amount of exhaust steam supplied to the second steam turbine based on the adjustment signal.

24. The heat utilization system according to claim 23 , wherein the control signal generator generates the control signal to minimize the amount of pressure drop caused by the pressure reduction member.

25. The heat utilization system according to claim 23 , wherein the adjustment signal generation unit generates the adjustment signal to stop the supply of the exhaust steam to the second steam turbine.

26. 26. The heat utilization system of claim 25, wherein the control signal generator generates the control signal to increase the amount of pressure reduction by the pressure reduction member when an increase in heat demand in the heat demand facility is detected based on the heat demand signal.

27. 26. The heat utilization system according to claim 25, wherein the control signal generation unit generates the control signal to reduce a flow area of ​​the exhaust steam in the pressure reduction member when an increase in heat demand in the heat demand facility is detected based on the heat demand signal.

28. Discharging the heated fluid from the discharge source; generating first steam from the water by heat exchange between the heating fluid and the water; driving a first steam turbine with the first steam; reducing the pressure of exhaust steam that is the steam after driving the first steam turbine; supplying the exhaust steam whose pressure has been reduced to a heat demand facility; Equipped with The step of reducing the pressure of the exhaust steam includes adjusting an amount of reduction in the pressure of the exhaust steam based on heat demand in the heat demand facility; The pressure reducing member for reducing the pressure of the exhaust steam is configured so that the amount of pressure reduction of the exhaust steam increases as the flow area of ​​the pressure reducing member decreases.

29. 29. The heat utilization method according to claim 28, wherein the step of reducing the pressure of the exhaust steam increases the amount of pressure reduction as heat demand in the heat demanding facility increases.

30. The step of reducing the pressure of the exhaust steam includes reducing the pressure of the exhaust steam using the pressure reducing member; 29. The heat utilization method according to claim 28, wherein the step of reducing the pressure of the exhaust steam comprises reducing a flow area of ​​the exhaust steam in the pressure reducing member in accordance with an increase in heat demand in the heat demand facility.

31. supplying a portion of the exhaust steam to a second steam turbine driven by the exhaust steam; adjusting the amount of exhaust steam supplied to the second steam turbine in accordance with heat demand in the heat demand facility; The heat utilization method according to any one of claims 28 to 30, comprising:

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