Heat utilization system and heat utilization method

Abstract

This heat utilization system is provided with: a heat recovery device that generates first vapor and second vapor having a lower pressure than the first vapor from water by heat exchange between a heating fluid and water; a discharge source that discharges the heating fluid; a first steam turbine driven by the first steam; a pressure reducing means for reducing the pressure of exhaust steam, which is steam after driving the first steam turbine; a heat demand device that uses the heat of at least a portion of the exhaust steam and / or the second steam; an exhaust vapor line communicating the first vapor turbine with the heat demand device; and a second vapor line from which the second vapor flows out, the second vapor line being connected to the exhaust vapor line downstream of the pressure reducing component.

Description

Technical Field

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

[0002] This application claims priority based on Japanese Patent Application No. 2022-181269 filed with the Japan Patent Office on November 11, 2022, and incorporates its content herein. Background Art

[0003] In Patent Documents 1 to 3, there are respectively described structures in which a part of the vapor (exhaust vapor) discharged from a medium-pressure steam turbine is used as a heat source for a carbon dioxide recovery device.

[0004] Prior Art Documents

[0005] Patent Document 1: Japanese Unexamined Patent Application Publication No. 2012-184712

[0006] Patent Document 2: Japanese Patent Application Laid-Open No. 2013-506091

[0007] Patent Document 3: Japanese Unexamined Patent Application Publication No. 2014-29139 Summary of the Invention

[0008] Problems to be Solved by the Invention

[0009] However, in any of the systems in Patent Documents 1 to 3, only the exhaust vapor from the steam turbine is used as the heat source for the carbon dioxide recovery device, so there is a problem that there may be a case where sufficient heat cannot be supplied to the carbon dioxide recovery device.

[0010] In view of the above situation, an object of at least one embodiment of the present disclosure is to provide a heat utilization system and a heat utilization method capable of supplying sufficient heat to a heat demand device.

[0011] Means for Solving the Problems

[0012] To achieve the above object, the heat utilization system of the present disclosure includes: a heat recovery device that generates first vapor and second vapor having a pressure lower than that of the first vapor from the water by heat-exchanging the heating fluid with the water; a discharge source that discharges the heating fluid; a first steam turbine driven by the first vapor; a pressure reducing component that reduces the pressure of the vapor (exhaust vapor) after driving the first steam turbine; a heat demand device that utilizes heat of at least a part of the exhaust vapor and at least one of the second vapor; an exhaust vapor pipeline that connects the first steam turbine and the heat demand device; and a second vapor pipeline through which the second vapor flows out from the heat recovery device, and the second vapor pipeline is connected to the exhaust vapor pipeline downstream of the pressure reducing component.

[0013] In addition, the heat utilization system of the present disclosure includes: a heat recovery device that generates first steam from the water by heat-exchanging a heating fluid with the water; a discharge source that discharges the heating fluid; a first steam turbine driven by the first steam; a pressure reducing component that reduces the pressure of the exhaust steam, which is the steam after driving the first steam turbine; and a heat demand device that utilizes at least part of the heat of the exhaust steam downstream of the pressure reducing component. Based on the heat demand in the heat demand device, the pressure reducing component adjusts the amount of pressure reduction of the exhaust steam.

[0014] In addition, the heat utilization method of the present disclosure includes the following steps: a step of discharging a heating fluid from a discharge source; a step of generating first steam from the water by heat-exchanging the heating fluid with the water; a step of driving a first steam turbine by the first steam; a step of reducing the pressure of the exhaust steam, which is the steam after driving the first steam turbine; and a step of supplying the exhaust steam with reduced pressure to a heat demand device. In the step of reducing the pressure of the exhaust steam, the amount of pressure reduction of the exhaust steam is adjusted based on the heat demand in the heat demand device.

[0015] Advantages of the Invention

[0016] 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 device. Therefore, sufficient heat can be supplied to the heat demand device.

[0017] In addition, according to the heat utilization system and heat utilization method of the present disclosure, by increasing the amount of pressure reduction of the exhaust steam, the pressure at the inlet of the pressure reducing component, i.e., the outlet of the first steam turbine, rises, the pressure expansion ratio of the first steam turbine decreases, and the output of the first steam turbine decreases. As a result, the temperature of the exhaust steam rises. Therefore, the amount of heat supplied to the heat demand device can be increased, and sufficient heat can be supplied to the heat demand device. Brief Description of the Drawings

[0018] Figure 1 is a schematic structural diagram of the heat utilization system according to Embodiment 1 of the present disclosure.

[0019] Figure 2 is a schematic structural diagram of the heat recovery device of the heat utilization system according to Embodiment 1 of the present disclosure.

[0020] Figure 3 is the T-Q line chart of the condensed water and exhaust gas in the low-pressure evaporator when the heat recovery device of the heat utilization system according to Embodiment 1 of the present disclosure has Figure 2 the structure shown.

[0021] Figure 4It is a schematic structural diagram for controlling the opening degree or flow path area of a pressure regulating valve in the heat utilization system of Embodiment 1 of the present disclosure.

[0022] Figure 5 It is a schematic structural diagram for controlling a component for regulating the supply amount of exhaust steam in the heat utilization system of Embodiment 1 of the present disclosure.

[0023] Figure 6 It is an example of a pressure reducing component that can be used in the heat utilization system of Embodiment 1 of the present disclosure.

[0024] Figure 7 It is an example of a pressure reducing component that can be used in the heat utilization system of Embodiment 1 of the present disclosure.

[0025] Figure 8 It is an example of a pressure reducing component that can be used in the heat utilization system of Embodiment 1 of the present disclosure.

[0026] Figure 9 It is an example of a pressure reducing component that can be used in the heat utilization system of Embodiment 1 of the present disclosure.

[0027] Figure 10 It is an example of a pressure reducing component that can be used in the heat utilization system of Embodiment 1 of the present disclosure.

[0028] Figure 11 It is along Figure 10 a cross-sectional view taken along line XI-XI.

[0029] Figure 12 It is a schematic structural diagram of the heat utilization system of Embodiment 2 of the present disclosure.

[0030] Figure 13 It is a structural diagram of a modified example of the heat utilization system of Embodiment 2 of the present disclosure.

[0031] Figure 14 It is a schematic structural diagram of the heat utilization system of Embodiment 3 of the present disclosure. Specific Embodiments

[0032] Hereinafter, the heat utilization system and heat utilization method of the embodiments of the present disclosure will be described based on the drawings. The embodiments described below represent one mode of the present disclosure and do not limit the present disclosure, and can be arbitrarily changed within the scope of the technical idea of the present disclosure.

[0033] (Embodiment 1)

[0034] <Structure of the heat utilization system of Embodiment 1 of the present disclosure>

[0035] As Figure 1As shown, the heat utilization system 1 of Embodiment 1 of the present disclosure includes: a heat recovery device 30 that generates first vapor and second vapor having a pressure lower than that of the first vapor from water through heat exchange between a heating fluid and water (including not only liquid water but also vapor); a gas turbine 20 that is a discharge source of the heating fluid; a steam turbine 40; a pressure regulating valve 50a that is a pressure reducing component 50 for reducing the pressure of the exhaust steam, which is the steam after driving the steam turbine 40; a heat demand device 60 that utilizes the heat of at least a part of the exhaust steam and at least one of the second vapor; an exhaust steam pipeline 51 that connects the steam turbine 40 and the heat demand device 60; and a second steam pipeline 32 through which the second vapor flows out from the heat recovery device 30. The second steam pipeline 32 is connected to the exhaust steam pipeline 51 downstream of the pressure reducing component 50.

[0036] A heat demand device inlet valve 52 is provided in the exhaust steam pipeline 51. By opening and closing the heat demand device inlet valve 52, the supply of at least a part of the exhaust steam and at least one of the second vapor to the heat demand device 60 can be carried out or stopped. The heat demand device inlet valve 52 is not limited to an on-off valve, and may also be a flow regulating valve capable of regulating the flow rate of at least a part of the exhaust steam and at least one of the second vapor. In the exhaust steam pipeline 51, an on-off valve 53 may also be provided between the pressure regulating valve 50a and the heat demand device inlet valve 52. By providing the on-off valve 53, the supply of the exhaust steam to the heat demand device 60 is stopped, so that only the second vapor can be supplied to the heat demand device 60.

[0037] The structure of the heat demand device 60 is not particularly limited. It may include a heat exchange mechanism for heating a solid, liquid, or gaseous object to be heated by the heat of at least a part of the exhaust steam and at least one of the second vapor, or may be a chemical device (such as a steam reforming device) that uses the exhaust steam as a raw material for a chemical reaction. In Embodiment 1, the heat demand device 60 is taken as an example of a district hot water and heating device 60a for explanation.

[0038] In the present disclosure, the structure of the steam turbine 40 is not particularly limited. However, in Embodiment 1, the steam turbine 40 includes: a high-pressure turbine 40a, a medium-pressure turbine 40b, and a low-pressure turbine 40c. The rotating shafts of the high-pressure turbine 40a and the medium-pressure turbine 40b are connected to each other, and a power generation device 41 driven by the rotation of the rotating shaft is provided. The low-pressure turbine 40c is provided independently of the high-pressure turbine 40a and the medium-pressure turbine 40b, and the medium-pressure turbine 40b and the low-pressure turbine 40c are connected through an exhaust steam branch pipeline 54 branched from the exhaust steam pipeline 51 downstream of the pressure regulating valve 50a. That is, the low-pressure turbine 40c is configured to be driven by at least a part of the exhaust steam discharged from the medium-pressure turbine 40b. A low-pressure turbine inlet valve 55 serving as a flow regulating valve is provided in the exhaust steam branch pipeline 54. A power generation device 42 driven by the low-pressure turbine 40c is provided in the low-pressure turbine 40c.

[0039] In the present disclosure, the steam turbine that discharges the exhaust steam supplied to the heat demand device 60 is defined as the first steam turbine, and the steam turbine driven by the exhaust steam of the first steam turbine is defined as the second steam turbine. In addition, the steam that drives the first steam turbine is defined as the first steam. Therefore, in Embodiment 1, 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 first steam turbine, i.e., the intermediate-pressure turbine 40b in Embodiment 1, will be described later.

[0040] The exhaust steam pipeline 70 through which the exhaust steam discharged from the low-pressure turbine 40c flows is connected to the condenser 71. In order to supply the condensed water generated in the condenser 71 to the heat recovery device 30, the condenser 71 and the heat recovery device 30 are communicated through a condensate pipeline 72. A condensate pump 73 is provided in the condensate pipeline 72 to supply the condensed water to the heat recovery device 30. The discharge pipeline 61 of the steam used in the district hot water and heating device 60a is connected to the exhaust steam pipeline 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 pipeline 61.

[0041] 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 the combustion gas generated by burning fuel in the combustor 22. A fuel supply pipeline 12 for supplying fuel is connected to the combustor 22. In addition, a power generation device 26 driven by the gas turbine 20 is provided.

[0042] In order to supply the exhaust gas discharged from the turbine 23 to the heat recovery device 30, the turbine 23 and the heat recovery device 30 are communicated via an exhaust pipeline 28. The heat recovery device 30 is configured such that the condensed water supplied to the heat recovery device 30 via the condensate pipeline 72 exchanges heat with the exhaust gas supplied to the heat recovery device 30 via the exhaust pipeline 28, whereby the condensed water is heated to generate two steams with different pressures. Here, the exhaust gas is the heating fluid that exchanges heat with the condensed water, and the gas turbine 20 is the discharge source that discharges the exhaust gas as the heating fluid. In order to supply the steam with a higher pressure generated in the heat recovery device 30 to the high-pressure turbine 40a, the heat recovery device 30 and the high-pressure turbine 40a are communicated via a steam supply pipeline 31. The steam with a lower pressure generated in the heat recovery device 30 corresponds to the above-mentioned second steam. In order to allow the second steam to flow out of the heat recovery device 30, the upstream end of the second steam pipeline 32 is connected to the heat recovery device 30.

[0043] In order to supply the exhaust steam of 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 pipeline 43. The heat recovery device 30 is also configured such that the exhaust steam supplied to the heat recovery device 30 via the exhaust steam pipeline 43 exchanges heat with the exhaust gas supplied to the heat recovery device 30 via the exhaust pipe 28, thereby heating the exhaust steam to generate reheated steam. 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 pipeline 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.

[0044] Refer to Figure 2 An example of the structure of the heat recovery device 30 that can generate the first steam and the second steam through the above heat exchange in the heat recovery device 30 will be described. The heat recovery device 30 includes an exhaust gas flow path 200 through which the exhaust gas supplied to the heat recovery device 30 via the exhaust pipe 28 flows. In the exhaust gas flow path 200, as a structure for generating the second steam, a low-pressure economizer 201, a low-pressure evaporator 202, and a low-pressure superheater 203 are provided. A condensate water pipeline 72 is connected to the low-pressure economizer 201. The low-pressure economizer 201 is connected to the low-pressure evaporator 202. The low-pressure evaporator 202 is connected to the low-pressure superheater 203. A second steam pipeline 32 is connected to the low-pressure superheater 203. With this structure, the condensate water supplied to the heat recovery device 30 via the condensate water pipeline 72 is heated to become the second steam by sequentially exchanging heat with the exhaust gas in the low-pressure economizer 201, the low-pressure evaporator 202, and the low-pressure superheater 203, flows out of the heat recovery device 30, and flows through the second steam pipeline 32.

[0045] In addition, in the exhaust gas flow path 200, as a structure for generating the first steam, a first reheater 204 and a second reheater 205 that are connected to each other are provided. The exhaust steam pipeline 43 is connected to the first reheater 204. The reheated steam supply pipeline 33 is connected to the second reheater 205. With this structure, the exhaust steam supplied to the heat recovery device 30 via the exhaust steam pipeline 43 is heated to become the first steam (reheated steam) by sequentially exchanging heat with the exhaust gas in the first reheater 204 and the second reheater 205, flows out of the heat recovery device 30, and flows through the reheated steam supply pipeline 33.

[0046] The heat recovery device 30 may also have a structure that generates first steam using a part of the condensed water supplied to the heat recovery device 30 via the condensate pipeline 72. As this structure, a medium-pressure economizer 206, a medium-pressure evaporator 207, and a medium-pressure superheater 208 are provided in the exhaust gas flow path 200. The medium-pressure economizer 206 is connected to the low-pressure economizer 201 via a pipeline 209, and a medium-pressure water supply pump 210 is provided in the pipeline 209. The medium-pressure economizer 206 is connected to the medium-pressure evaporator 207, and the medium-pressure evaporator 207 is connected to the medium-pressure superheater 208. The other end of the steam pipeline 211 connected to one end of the medium-pressure superheater 208 is connected to the exhaust steam pipeline 43. With this structure, when a part of the condensed water heated by the low-pressure economizer 201 sequentially flows through the medium-pressure economizer 206, the medium-pressure evaporator 207, and the medium-pressure superheater 208 via the medium-pressure water supply pump 210, it exchanges heat with the exhaust gas to become steam, mixes with the exhaust steam flowing in the exhaust steam pipeline 43 via the steam pipeline 211, and is supplied to the heat recovery device 30 again, becoming the first steam.

[0047] In addition, in the exhaust gas flow path 200, as a structure for generating steam supplied to the high-pressure turbine 40a, 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. The first high-pressure economizer 212 is connected to the low-pressure economizer 201 via a pipeline 217, and a high-pressure water supply pump 218 is provided in the pipeline 217. The first high-pressure economizer 212 is connected to the second high-pressure economizer 213, the second high-pressure economizer 213 is connected to the high-pressure evaporator 214, the high-pressure evaporator 214 is connected to the first high-pressure superheater 215, and the first high-pressure superheater 215 is connected to the second high-pressure superheater 216. A steam supply pipeline 31 is connected to the second high-pressure superheater 216. With this structure, when a part of the condensed water heated by the low-pressure economizer 201 sequentially flows 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 via the high-pressure water supply pump 218, it exchanges heat with the exhaust gas to become steam, flows out of the heat recovery device 30, and flows in the steam supply pipeline 31.

[0048] As described above, heating fluid (exhaust gas) is supplied to the heating fluid flow path (exhaust gas flow path 200) of the heat recovery device 30. In the heating fluid flow path (exhaust gas flow path 200), a second high-pressure superheater 216 (with a second reheater 205 in parallel), a first reheater 204, a first high-pressure superheater 215, a high-pressure evaporator 214, a second high-pressure economizer 213, a medium-pressure superheater 208, a medium-pressure evaporator 207, a medium-pressure economizer 206 (with a first high-pressure economizer 212 in parallel), a low-pressure superheater 203, a low-pressure evaporator 202, and a low-pressure economizer 201 are arranged in sequence from the upstream to the 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 device 30 exchanges heat with the steam or water flowing in the superheater, reheater, evaporator, or economizer in the above-mentioned order to heat the steam or water. A plurality of evaporators (high-pressure evaporator 214, medium-pressure evaporator 207, low-pressure evaporator 202) are provided in the heating fluid flow path (exhaust gas flow path 200) of the heat recovery device 30. The low-pressure evaporator 202 is arranged at the most downstream when observed from the flow of the heating fluid (exhaust gas) among the plurality of evaporators provided in the heating fluid flow path (exhaust gas flow path 200) of the heat recovery device 30. In addition, among the plurality of evaporators provided in the heating fluid flow path (exhaust gas flow path 200) of the heat recovery device 30, the low-pressure evaporator 202 has the lowest pressure of the evaporated steam.

[0049] In addition, in the heat utilization system of the present embodiment, three-pressure evaporators, namely, a high-pressure evaporator 214, a medium-pressure evaporator 207, and a low-pressure evaporator 202, are provided. However, an evaporator with a pressure higher than that of the high-pressure evaporator 214 may be provided, and a total of four evaporators may be provided. Or, instead of providing three evaporators, only two evaporators, such as a high-pressure evaporator 214 and a low-pressure evaporator 202, or a medium-pressure evaporator 207 and a low-pressure evaporator 202, may be provided. In addition, in the heat utilization system 1 of Embodiment 1, the steam after driving the high-pressure turbine 40a is sent to the reheater for reheating. However, the reheater may not be provided, and the outlet of the high-pressure turbine 40a may be directly connected to the inlet of the medium-pressure turbine 40b. In addition, in this case, the steam flow path connecting the outlet of the high-pressure turbine 40a and the inlet of the medium-pressure turbine 40b may be connected to the steam pipeline 211, and the steam evaporated by the medium-pressure evaporator 207 may be supplied to the inlet of the medium-pressure turbine 40b together with the steam after driving the high-pressure turbine 40a. Moreover, in this case, the high-pressure turbine 40a and the medium-pressure turbine 40b may be integrated, or the steam pipeline 211 may be connected at the intermediate stage of the turbine to supply the steam evaporated by the medium-pressure evaporator 207. As described above, the heat recovery device 30 and the steam turbine 40 can adopt various structures within the scope not violating the gist of the present invention.

[0050] In order for the exhaust gas that has undergone heat exchange with the condensed water and the exhaust steam of the high-pressure turbine 40a to flow out of the heat recovery device 30, one end of the exhaust pipe line 29 is connected to the heat recovery device 30. The other end of the exhaust pipe line 29 is connected to the chimney 10.

[0051] <Operation (heat utilization method) of the heat utilization system according to Embodiment 1 of the present disclosure>

[0052] Next, the operation of the heat utilization system according to Embodiment 1 of the present disclosure will be described. Fuel is supplied to the burner 22 of the gas turbine 20 via the fuel supply line 12. Fuel and compressed air compressed by the compressor 21 are supplied to the burner 22, and the fuel is burned using the compressed air. The combustion gas generated by burning the fuel in the burner 22 drives the turbine 23. The power generation device 26 is driven by the rotation of the compressor 21 and the turbine 23 to generate electricity.

[0053] The exhaust gas discharged from the turbine 23 flows into the heat recovery device 30 via the exhaust pipe line 28. In the heat recovery device 30, the exhaust gas is cooled by heat exchange with water. In addition, as 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 device 30 flows through the exhaust pipe line 29 and is discharged into the atmosphere via the chimney 10.

[0054] On the other hand, the water heated by heat exchange with the exhaust gas in the heat recovery device 30 flows out of the heat recovery device 30 as two kinds of steam with different pressures. The steam with a higher pressure 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 steam with a lower pressure flows through the second steam pipe line 32 as the second steam. The exhaust steam discharged from the high-pressure turbine 40a after driving the high-pressure turbine 40a flows through the exhaust steam pipe line 43 and flows into the heat recovery device 30 again. In the heat recovery device 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 reheated steam supply line 33 and drives the intermediate-pressure turbine 40b. The power generation device 41 is driven by the high-pressure turbine 40a and the intermediate-pressure turbine 40b to generate electricity.

[0055] After driving the medium-pressure turbine 40b, the exhaust steam discharged from the medium-pressure turbine 40b flows in the exhaust steam pipeline 51. Through the operation of the heat demand equipment inlet valve 52, the on-off valve 53, and the low-pressure turbine inlet valve 55, the exhaust steam flows into either the low-pressure turbine 40c and the district hot water and heating equipment 60a or both the low-pressure turbine 40c and the district hot water and heating equipment 60a. The exhaust steam supplied to the low-pressure turbine 40c via the exhaust steam branch pipeline 54 drives the low-pressure turbine 40c, and the power generation device 42 is driven by the low-pressure turbine 40c to generate electricity.

[0056] After driving the low-pressure turbine 40c, the exhaust steam discharged from the low-pressure turbine 40c flows in the exhaust steam pipeline 70 and flows into the condenser 71. The exhaust steam flowing into the condenser 71 condenses into condensed water, which flows in the condensed water pipeline 72 through the condensate pump 73 and is supplied to the heat recovery device 30 for heat exchange with the above-mentioned exhaust gas.

[0057] When at least a part of the exhaust steam discharged from the medium-pressure turbine 40b is supplied to the district hot water and heating equipment 60a, during the period when the exhaust steam flows in the exhaust steam pipeline 51, it mixes with the second steam flowing in the second steam pipeline 32 and flows into the district hot water and heating equipment 60a. As described above, if the on-off valve 53 is fully closed, only the second steam can be supplied to the district hot water and heating equipment 60a. The second steam (and exhaust steam) flowing into the district hot water and heating equipment 60a is used as the heat source for hot water supply and heating. The pressure of the second steam (and exhaust steam) in the district hot water and heating equipment 60a can be adjusted by the pressure regulating valve 62. Thus, by keeping the pressure in the district hot water and heating equipment 60a sufficiently high, sufficient steam density and sufficient heat conductivity can be obtained, so that the required heat can be provided. In addition, the steam can be condensed at the temperature required in the district hot water and heating equipment 60a. The second steam (and exhaust steam) used as the heat source in the district hot water and heating equipment 60a condenses into water, flows in the discharge pipeline 61 through the pump 63, and then flows into the condensed water pipeline 72 and is supplied to the heat recovery device 30 together with the condensed water.

[0058] In this way, in the heat utilization system 1, not only the exhaust steam, which is the steam after driving the medium-pressure turbine 40b, but also the second steam supplied from the heat recovery device 30 can be utilized as the heat source for the district hot water and heating equipment 60a. Therefore, sufficient heat can be supplied to the district hot water and heating equipment 60a.

[0059] <Control Based on the Heat Demand in the Heat Demand Equipment>

[0060] Next, a method for controlling the heat supplied to the district hot water and heating equipment 60a based on the heat demand of the district hot water and heating equipment 60a will be described in the case where at least a part of the exhaust steam discharged from the medium-pressure turbine 40b is supplied to the district hot water and heating equipment 60a. For example, the heat supplied to the district hot water and heating equipment 60a can be controlled by changing the opening degree of the pressure regulating valve 50a. When the opening degree of the pressure regulating valve 50a is reduced, that is, when the flow path area of the pressure regulating valve 50a is reduced, the pressure reduction amount (pressure loss) of the exhaust steam based on the pressure regulating valve 50a becomes larger. Then, the pressure at the inlet of the pressure regulating valve 50a, that is, the outlet of the medium-pressure turbine 40b (first steam turbine), rises, the expansion ratio of the medium-pressure turbine 40b (first steam turbine) decreases, the output of the medium-pressure turbine 40b (first steam turbine) decreases, and thus the temperature of the exhaust steam discharged from the medium-pressure turbine 40b (first steam turbine) rises. Therefore, the heat supplied to the district hot water and heating equipment 60a increases. On the other hand, when the heat demand of the district hot water and heating equipment 60a is low, the opening degree of the pressure regulating valve 50a, that is, the flow path area, is maximized. If the opening degree of the pressure regulating valve 50a, that is, the flow path area, is reduced as the heat demand of the district hot water and heating equipment 60a becomes higher, the temperature of the exhaust steam discharged from the medium-pressure turbine 40b (first steam turbine) rises, and thus heat corresponding to the heat demand of the district hot water and heating equipment 60a can be supplied to the district hot water and heating equipment 60a.

[0061] The effects in the case where the heat recovery device 30 has Figure 2 the structure will be described. Figure 3 The TQ line graph shown is a graph showing a line representing the relationship between the heat recovery amount of the condensate in the low-pressure evaporator 202 of the heat recovery device 30 and the temperature (lines in the case where the saturated vapor pressure in the low-pressure evaporator 202 is high and low) and a line representing the relationship between the heat of the exhaust gas and the temperature. When the saturated vapor pressure and the saturated vapor temperature in the low-pressure evaporator 202 are reduced, that is, when in Figure 3 the line depicted by the solid line in the case where the saturated vapor pressure in the low-pressure evaporator 202 is high becomes the line depicted by the dashed line in the case where the saturated vapor pressure in the low-pressure evaporator 202 is low, the heat recovery amount of the latter can be increased compared to the former. In the present embodiment, a pressure regulating valve 50a (pressure reducing component) is provided, and by increasing the pressure reduction amount (pressure loss), the pressure of the exhaust steam pipeline 51 downstream of the pressure regulating valve 50a (pressure reducing component) is maintained at a lower level, and thus the saturated vapor pressure in the second steam pipeline 32 connected to the exhaust steam pipeline 51 downstream of the pressure regulating valve 50a (pressure reducing component) and the low-pressure evaporator 202 of the heat recovery device 30 that supplies steam to the second steam pipeline 32 can also be maintained at a lower level. Therefore, as Figure 3As shown, it is possible to increase the amount of heat recovered from the condensed water in the low-pressure evaporator 202 of the heat recovery device 30. At the same time, the temperature of the exhaust steam discharged from the medium-pressure turbine 40b (first steam turbine) is increased by the above-described operation, whereby it is possible to further increase the amount of heat that can be supplied to the district hot water and heating equipment 60a. In the present embodiment, a pressure regulating valve 50a (pressure reducing component) is provided, and by increasing the pressure reduction amount (pressure loss), it is possible to keep the pressure downstream of the pressure regulating valve 50a (pressure reducing component) low and increase the pressure upstream of the pressure regulating valve 50a (pressure reducing component). Therefore, while keeping the saturated vapor pressure in the low-pressure evaporator 202 of the heat recovery device 30 low, it is possible to increase the temperature and heat of the exhaust steam discharged from the medium-pressure turbine 40b (first steam turbine), and increase the amount of heat supplied to the district hot water and heating equipment 60a (heat demand equipment).

[0062] Next, the above control regarding the opening degree or flow path area of the pressure regulating valve 50a (pressure reducing component) will be described. The opening degree or flow path area of the pressure regulating valve 50a (pressure reducing component) is used to meet the heat demand when the heat demand of the district hot water and heating equipment 60a (heat demand equipment) changes. As Figure 4 shown, a heat supply amount control device 501 is provided in the heat utilization system 1. The heat supply amount control device 501 includes: a receiving unit 511 that receives a heat demand signal, which is a signal related to the heat demand of the district hot water and heating equipment 60a (heat demand equipment), from the district hot water and heating equipment 60a (heat demand equipment); a control signal generation unit 512 that generates a control signal for controlling the opening degree or flow path area of the pressure regulating valve 50a using the heat demand signal; and a control signal transmission unit 513 that transmits the control signal to the pressure regulating valve 50a. The receiving unit 511 is electrically connected to the control signal generation unit 512, and the control signal generation unit 512 is electrically connected to the control signal transmission unit 513.

[0063] The receiving unit 511 is electrically connected via a heat demand signal line 502 to a control device 60a1 that controls the operation of a district hot water and heating device 60a (heat demand device), such as the district hot water and heating device 60a (heat demand device), so as to be able to receive a heat demand signal from the district hot water and heating device 60a (heat demand device). The control signal transmitting unit 513 is electrically connected via a control signal line 503 to a drive unit (not shown) for controlling the opening degree or flow path area of a pressure regulating valve 50a (pressure reducing component) in order to transmit a control signal to the drive unit. Additionally, in the case where the heat demand signal is transmitted and received between the receiving unit 511 and the district hot water and heating device 60a (heat demand device) and / or the control signal is transmitted and received between the control signal transmitting unit 513 and the pressure regulating valve 50a (pressure reducing component) by wireless communication, either or both of the heat demand signal line 502 and the control signal line 503 can be omitted.

[0064] The heat supply amount control device 501 is composed of, for example, a CPU (Central Processing Unit), a RAM (Random Access Memory), a ROM (Read Only Memory), and a computer-readable storage medium, etc. And, as an example, a series of processes for implementing various functions are stored in a storage medium, etc. in the form of a program, and the CPU reads the program into the RAM, etc., and executes information processing and arithmetic processing, thereby implementing various functions. Additionally, the program can also be applied in a manner of being pre-installed in the ROM or other storage media, in a state of being stored in a computer-readable storage medium, in a manner of being distributed via a wired or wireless communication unit, etc. The computer-readable storage medium is a magnetic disk, a magneto-optical disk, a CD-ROM, a DVD-ROM, a semiconductor memory, etc.

[0065] In the case where there is a heat supply amount control device 501, the heat demand of the district hot water and heating equipment 60a (heat demand device) is continuously or intermittently transmitted as a heat demand signal, and the receiving unit 511 of the heat supply amount control device 501 receives the heat demand signal. The control signal generation unit 512 uses the heat demand signal received by the receiving unit 511 to generate a control signal for controlling the opening degree or flow path area of the pressure regulating valve 50a (pressure reducing component). For example, a map representing the relationship between the opening degree or flow path area of the pressure regulating valve 50a (pressure reducing component) and the exhaust steam temperature and a map representing the relationship between the change amounts of the flow rate and temperature of the exhaust steam and the change amount of the heat demand of the district hot water and heating equipment 60a (heat demand device) can be pre-loaded in the control signal generation unit 512, and based on these maps, the opening degree or flow path area of the pressure regulating valve 50a (pressure reducing component) is determined, and a control signal is generated. The control signal transmission unit 513 transmits the control signal generated by the control signal generation unit 512 to the drive unit of the pressure regulating valve 50a. The drive unit of the pressure regulating valve 50a can set the opening degree or flow path area of the pressure regulating valve 50a (pressure reducing component) corresponding to the heat demand of the district hot water and heating equipment 60a (heat demand device) by adjusting the opening degree or flow path area of the pressure regulating valve 50a based on the control signal.

[0066] In the case where the heat demand of the district hot water and heating equipment 60a (heat demand device) is low, a control signal for maximizing the opening degree or flow path area of the pressure regulating valve 50a (pressure reducing component), that is, a control signal for minimizing the pressure reduction amount, is generated. In the case where the heat demand of the district hot water and heating equipment 60a (heat demand device) increases, a control signal for reducing the opening degree or flow path area of the pressure regulating valve 50a (pressure reducing component), that is, a control signal for increasing the pressure reduction amount, is generated. In the case where the heat demand of the district hot water and heating equipment 60a (heat demand device) decreases, a control signal for increasing the opening degree or flow path area of the pressure regulating valve 50a (pressure reducing component), that is, a control signal for reducing the pressure reduction amount, is generated.

[0067] As will be described below, not only the opening degree of the pressure regulating valve 50a (pressure reducing component) is adjusted, but also the opening degree of the heat demand device inlet valve 52 or the low-pressure turbine inlet valve 55 (exhaust steam supply amount regulating component) as a flow regulating valve is adjusted, so that heat corresponding to a wide range of heat demands of the district hot water and heating equipment 60a can be supplied to the district hot water and heating equipment 60a. As Figure 1As shown, when the heat demand of the district hot water and heating equipment 60a (heat demand equipment) is low, the opening degree, i.e., the flow path area, of the pressure regulating valve 50a (pressure reducing component) is maximized. The heat demand of the district hot water and heating equipment 60a (heat demand equipment) is compared with the heat supply amount to the district hot water and heating equipment 60a (heat demand equipment). When the heat demand is large, the opening degree of the low-pressure turbine inlet valve 55 (exhaust steam supply amount regulating component) is reduced. Then, by reducing the supply amount of the exhaust steam to the low-pressure turbine 40c and increasing the supply amount of the exhaust steam to the district hot water and heating equipment 60a (heat demand equipment), the heat supply amount to the district hot water and heating equipment 60a (heat demand equipment) increases, and the heat demand of the district hot water and heating equipment 60a (heat demand equipment) can be satisfied. On the contrary, when the heat demand is small in the above comparison, the opening degree of the low-pressure turbine inlet valve 55 (exhaust steam supply amount regulating component) is increased. Then, by increasing the supply amount of the exhaust steam to the low-pressure turbine 40c (second steam turbine) and reducing the supply amount of the exhaust steam to the district hot water and heating equipment 60a (heat demand equipment), the heat supply amount to the district hot water and heating equipment 60a (heat demand equipment) decreases, and the heat demand of the district hot water and heating equipment 60a (heat demand equipment) can be satisfied. In this case, the pressure reduction amount of the exhaust steam caused by the pressure regulating valve 50a (pressure reducing component) is the smallest, so the heat demand of the district hot water and heating equipment 60a (heat demand equipment) can be satisfied without reducing the output of the medium-pressure turbine 40b (first steam turbine). As described above, when the heat demand of the district hot water and heating equipment 60a (heat demand equipment) is low, the opening degree, i.e., the flow path area, of the pressure regulating valve 50a (pressure reducing component) is maximized, and the pressure reduction amount (pressure loss) is minimized, and the heat demand of the district hot water and heating equipment 60a (heat demand equipment) can still be satisfied. In this case, it is preferable to maintain the state where the opening degree, i.e., the flow path area, of the pressure regulating valve 50a (pressure reducing component) is the largest and the pressure reduction amount (pressure loss) is the smallest. This is because the smaller the pressure reduction amount (pressure loss) in the pressure regulating valve 50a (pressure reducing component), the greater the output of the medium-pressure turbine 40b (first steam turbine), and the efficiency of the equipment can also be improved.

[0068] Even when the low-pressure turbine inlet valve 55 (exhaust steam supply amount regulating component) is fully closed and the supply of the exhaust steam to the low-pressure turbine 40c (second steam turbine) stops, when the heat demand is large in the above comparison, the pressure and temperature of the exhaust steam can also be adjusted by adjusting the opening degree of the above-mentioned pressure regulating valve 50a (pressure reducing component) to satisfy the heat demand of the district hot water and heating equipment 60a (heat demand equipment).

[0069] In addition, in the above control, the opening degree of the pressure regulating valve 50a (pressure reducing component) starts from the fully open state, but is not limited to this mode. It can also start from any opening degree of the pressure regulating valve 50a (pressure reducing component) adjusted to maintain an arbitrary output of the high-pressure turbine 40a and the medium-pressure turbine 40b. In this state, control is performed based on the low-pressure turbine inlet valve 55 (exhaust steam supply amount regulating component). When the heat demand of the district hot water and heating equipment 60a (heat demand equipment) cannot be satisfied even when the low-pressure turbine inlet valve 55 (exhaust steam supply amount regulating component) is fully closed, the heat supply to the district hot water and heating equipment 60a (heat demand equipment) can be increased by adjusting the opening degree of the pressure regulating valve 50a (pressure reducing component).

[0070] In the above control, the heat supply to the district hot water and heating equipment 60a (heat demand equipment) is adjusted by adjusting the opening degree of the low-pressure turbine inlet valve 55, but is not limited to this mode. The heat supply to the district hot water and heating equipment 60a (heat demand equipment) can also be adjusted by adjusting the opening degree of the heat demand equipment inlet valve 52. In this case, the opening degree of the heat demand equipment inlet valve 52 is changed in the direction opposite to the direction of changing the opening degree of the low-pressure turbine inlet valve 55. Specifically, in the above control, when the opening degree of the low-pressure turbine inlet valve 55 is reduced, an operation of increasing the opening degree of the heat demand equipment inlet valve 52 is performed. This is because the exhaust steam discharged from the medium-pressure turbine 40b (first steam turbine) flows into either the low-pressure turbine 40c (second steam turbine) or the district hot water and heating equipment 60a (heat demand equipment). Therefore, if the supply amount of exhaust steam to the district hot water and heating equipment 60a (heat demand equipment) is increased, the supply amount of exhaust steam to the low-pressure turbine 40c (second steam turbine) is reduced, and if the supply amount of exhaust steam to the district hot water and heating equipment 60a (heat demand equipment) is reduced, the supply amount of exhaust steam to the low-pressure turbine 40c (second steam turbine) is increased. Therefore, the heat demand equipment inlet valve 52 and the low-pressure turbine inlet valve 55 respectively constitute exhaust steam supply amount regulating components for regulating the supply amount of exhaust steam supplied to the low-pressure turbine 40c (second steam turbine).

[0071] Next, the above control of the exhaust steam supply amount regulating component for satisfying the heat demand when the heat demand of the district hot water and heating equipment 60a (heat demand equipment) changes will be described. As Figure 5As shown, the heat supply amount control device 501 further includes: an adjustment signal generation unit 522 that generates an adjustment signal for adjusting the supply amount of exhaust steam supplied to the low-pressure turbine 40c (second steam turbine) using a heat demand signal; and an adjustment signal transmission unit 523 that transmits the adjustment signal to an exhaust steam supply amount adjustment component (heat demand equipment inlet valve 52 or low-pressure turbine inlet valve 55). The adjustment signal generation unit 522 is electrically connected to the reception unit 511, and the adjustment signal generation unit 522 is electrically connected to the adjustment signal transmission unit 523.

[0072] The adjustment signal transmission unit 523 is electrically connected to the drive unit of the heat demand equipment inlet valve 52 or the low-pressure turbine inlet valve 55 (exhaust steam supply amount adjustment component) via the adjustment signal line 504a or 504b in order to transmit an adjustment signal to a drive unit (not shown) for controlling 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). In addition, the adjustment signal transmission unit 523 is electrically connected to the drive unit of the on-off valve 53 via the on-off control signal line 505 in order to transmit an on-off control signal for opening and closing the on-off valve 53 to a drive unit (not shown) of the on-off valve 53. In addition, in the case where each or either of the transmission and reception of the adjustment signal between the adjustment signal transmission unit 523 and the heat demand equipment inlet valve 52 or the low-pressure turbine inlet valve 55 (exhaust steam supply amount adjustment component) and 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, each or either of the adjustment signal line 504a or 504b and the on-off control signal line 505 can be omitted.

[0073] As described above, when adjusting the opening degree of the inlet valve 52 of the heat demand device or the inlet valve 55 of the low-pressure turbine (exhaust steam supply amount adjustment component) to supply heat corresponding to a wide range of heat demands of the district hot water and heating device 60a (heat demand device) to the district hot water and heating device 60a (heat demand device), the adjustment signal generation unit 522 uses the heat demand signal received by the reception unit 511 to generate an adjustment signal for adjusting the supply amount of the exhaust steam supplied to the low-pressure turbine 40c (second steam turbine). For example, a mapping indicating the relationship between the opening degree of the inlet valve 52 of the heat demand device or the inlet valve 55 of the low-pressure turbine (exhaust steam supply amount adjustment component) and the supply amount of the exhaust steam supplied to the low-pressure turbine 40c (second steam turbine) and a mapping indicating the relationship between the change amount of the supply amount of the exhaust steam to the district hot water and heating device 60a (heat demand device) and the change amount of the heat demand of the district hot water and heating device 60a (heat demand device) can be pre-loaded into the adjustment signal generation unit 522, and based on these mappings, the opening degree of the inlet valve 52 of the heat demand device or the inlet valve 55 of the low-pressure turbine (exhaust steam supply amount adjustment component) is determined, and an adjustment signal is generated. The adjustment signal transmission unit 523 transmits the adjustment control signal generated by the adjustment signal generation unit 522 to the drive unit of the inlet valve 52 of the heat demand device or the inlet valve 55 of the low-pressure turbine (exhaust steam supply amount adjustment component). The drive unit of the inlet valve 52 of the heat demand device or the inlet valve 55 of the low-pressure turbine (exhaust steam supply amount adjustment component) adjusts the opening degree of the inlet valve 52 of the heat demand device or the inlet valve 55 of the low-pressure turbine (exhaust steam supply amount adjustment component) to the opening degree based on the adjustment signal, whereby the supply amount of the exhaust steam supplied to the low-pressure turbine 40c (second steam turbine) changes, and the amount of exhaust steam corresponding to the heat demand of the district hot water and heating device 60a (heat demand device) can be supplied to the district hot water and heating device 60a (heat demand device).

[0074] When the heat demand of the district hot water and heating equipment 60a (heat demand equipment) is low, an adjustment signal for minimizing the opening degree of the heat demand equipment inlet valve 52 or an adjustment signal for maximizing the opening degree of the low-pressure turbine inlet valve 55 is generated. Alternatively, the adjustment signal generation unit 522 may also generate an opening / closing control signal for closing the on-off valve 53, and the adjustment signal transmission unit 523 transmits this opening / closing control signal to the on-off valve 53, thereby closing the on-off valve 53 according to the opening / closing control signal. When the heat demand of the district hot water and heating equipment 60a increases, an adjustment signal for increasing the opening degree of the heat demand equipment inlet valve 52 or an adjustment signal for decreasing the opening degree of the low-pressure turbine inlet valve 55 is generated. As a result, the supply amount of the exhaust steam to the district hot water and heating equipment 60a (heat demand equipment) increases, so that the increase in the heat demand of the district hot water and heating equipment 60a (heat demand equipment) can be coped with. According to the heat demand of the district hot water and heating equipment 60a (heat demand equipment), an adjustment signal for making the opening degree of the low-pressure turbine inlet valve 55 zero, that is, fully closing the low-pressure turbine inlet valve 55, is generated. As a result, the entire amount of the exhaust steam is supplied to the district hot water and heating equipment 60a (heat demand equipment). However, in the case where the heat demand of the district hot water and heating equipment 60a (heat demand equipment) still cannot be coped with even so, the opening degree or the flow path area of the pressure regulating valve 50a (pressure reducing component) is adjusted by the above control. When the heat demand of the district hot water and heating equipment 60a (heat demand equipment) decreases, an adjustment signal for decreasing the opening degree of the heat demand equipment inlet valve 52 or an adjustment signal for increasing the opening degree of the low-pressure turbine inlet valve 55 is generated. As a result, the supply amount of the exhaust steam to the district hot water and heating equipment 60a decreases, so that the decrease in the heat demand of the district hot water and heating equipment 60a (heat demand equipment) can be coped with.

[0075] In addition, the above control based on the heat demand of the district hot water and heating equipment 60a (heat demand equipment) can also be applied to a structure that does not supply the second steam to the district hot water and heating equipment 60a (heat demand equipment). This structure can be, for example, obtained by removing the structure for generating the second steam from the heat recovery device 30 (low-pressure economizer 201, low-pressure evaporator 202, low-pressure superheater 203 (refer to Figure 2)) or by moving the on-off valve 53 provided in the exhaust steam pipeline 51 to the second steam pipeline 32 and closing the on-off valve 53, etc. In this structure, the pressure of the exhaust steam is also reduced by adjusting the opening degree or flow path area of the pressure regulating valve 50a (pressure reducing component), whereby the pressure expansion ratio of the medium-pressure turbine 40b (first steam turbine) is reduced, and the output of the medium-pressure turbine 40b (first steam turbine) is reduced. As a result, the temperature of the exhaust steam rises, so that the amount of heat supplied to the district hot water and heating equipment 60a (heat demand equipment) can be increased, and sufficient heat can be supplied to the district hot water and heating equipment 60a (heat demand equipment). In addition, in this structure, the supply amount of the exhaust steam supplied to the low-pressure turbine 40c (second steam turbine) is also adjusted to adjust the supply amount of the exhaust steam to the district hot water and heating equipment 60a (heat demand equipment), so that sufficient heat can be supplied to the district hot water and heating equipment 60a (heat demand equipment).

[0076] <Deformation example of pressure reducing component>

[0077] In Embodiment 1, the pressure reducing component 50 is the pressure regulating valve 50a, but it is not limited to this embodiment. Hereinafter, several deformation examples of the pressure reducing component 50 will be illustrated. In addition, the deformation examples shown below are merely illustrative, and are not intended to limit the mode of the pressure reducing component 50 thereto.

[0078] As Figure 6 shown, the pressure reducing component 50 may also be a structure including a plurality of branch pipelines 56 arranged in parallel with each other and on-off valves 57 provided in each branch pipeline 56. By opening and closing each on-off valve 57, the number of branch pipelines 56 through which the exhaust steam flows is changed, so that the pressure loss of the exhaust steam caused by the pressure reducing component 50 changes, and thus the amount of pressure reduction of the exhaust steam can be adjusted. Specifically, all the on-off valves 57 are opened to minimize the amount of pressure reduction, and the number of closed on-off valves 57 is increased to increase the amount of pressure reduction of the exhaust steam. When the number of closed on-off valves 57 increases, the number of branch pipelines 56 through which the exhaust steam flows decreases, that is, the flow path area of the pressure reducing component 50 becomes smaller, and the pressure loss of the exhaust steam caused by the pressure reducing component 50 becomes larger, so that the amount of pressure reduction of the exhaust steam can be increased. In addition, the number of branch pipelines 56 can be arbitrarily changed.

[0079] As Figure 7As shown, the pressure reducing component 50 can also be configured to include: a first pipeline 64 that branches from the exhaust steam pipeline 51 and has a plurality of folding portions; a second pipeline 65 that branches from the exhaust steam pipeline 51 on the downstream side of the first pipeline 64; a plurality of connecting pipelines 66, one end of which is connected to the first pipeline 64 and the other end of which is connected to the second pipeline 65, and are arranged side by side; and an on-off valve 67 provided in each connecting pipeline 66. By opening any one of the on-off valves 67 provided in each connecting pipeline 66, the distance through which the exhaust steam flows successively in the first pipeline 64, any one of the connecting pipelines 66, and the second pipeline 65 changes, and the pressure loss of the exhaust steam caused by the pressure reducing component 50 changes. Therefore, the amount of pressure reduction of the exhaust steam can be adjusted. Specifically, in order to minimize the amount of pressure reduction, the on-off valve 67a provided in the connecting pipeline 66a that connects between the branch points of the first pipeline 64 and the second pipeline 65 branched from the exhaust steam pipeline 51 is opened. In order to maximize the amount of pressure reduction of the exhaust steam, the on-off valve 67b provided in the connecting pipeline 66b that is farthest from the connecting pipeline 66a is opened. In addition, the number of connecting pipelines 66 can be arbitrarily changed. In addition, the second pipeline 65 can also have a plurality of folding portions, and both the first pipeline 64 and the second pipeline 65 can have a plurality of folding portions. The more the number of folding portions or the longer each folding portion, the greater the difference in pressure loss caused by changing the opened on-off valve 67. Therefore, the range of the amount of pressure reduction that can be adjusted by the pressure reducing component 50 can be expanded.

[0080] As Figure 8 shown, the pressure reducing component 50 can also be a structure that can change the number of orifice plates 75 connected in series to the exhaust steam pipeline 51. As a part for inserting the orifice plate 75, a housing 76 capable of accommodating the orifice plate 75 can also be provided in the exhaust steam pipeline 51. In addition, the pressure reducing component 50 can be a structure in which the orifice plate 75 is added or removed manually, or can be a structure in which the orifice plate 75 is added or removed by a hydraulic cylinder or the like. In this pressure reducing component 50, in order to minimize the amount of pressure reduction, the number of orifice plates 75 is set to zero, the orifice plate 75 is added to increase the amount of pressure reduction, and the orifice plate 75 is removed to reduce the amount of pressure reduction.

[0081] Figures 6 - 8 The pressure reducing component 50 having the structure shown is provided in the exhaust steam pipeline 51 to reduce the pressure of the exhaust steam discharged from the medium-pressure turbine 40b. However, the pressure reducing component 50 is not limited to such a structure, and can also reduce the pressure of the exhaust steam before it is discharged from the medium-pressure turbine 40b after driving the medium-pressure turbine 40b. Hereinafter, two examples of the pressure reducing component 50 having this structure will be described.

[0082] As Figure 9As shown, the pressure reducing component 50 may also be a grid 50b provided inside the casing 44 of the medium-pressure turbine 40b on the downstream side of the last-stage stationary blade 45 and moving blade 46. The grid 50b has a structure in which a plurality of vane-shaped components 48 are provided in parallel with the shaft portion 47, and is configured to increase or decrease the flow path area when the exhaust steam after driving the medium-pressure turbine 40b passes through the grid 50b by changing the angle of the vane-shaped component 48. The grid 50b can adjust the pressure reduction amount of the exhaust steam by changing the angle of the vane-shaped component 48.

[0083] As Figure 10 shown, the pressure reducing component 50 may also have a structure including two circular plates 58 and 59 provided inside the casing 44 of the medium-pressure turbine 40b on the downstream side of the last-stage stationary blade 45 and moving blade 46. As Figure 11 shown, the circular plates 58 and 59 have the same structure. Around the holes 58a and 59a into which the rotating shaft of the medium-pressure turbine 40b is inserted, holes 58b and 59b having the same shape are provided at the same intervals along the circumferences of the holes 58a and 59a. By rotating either one of the circular plates 58 and 59, the overlapping area of the holes 58a and 59a changes. The overlapping portion of the holes 58a and 59a becomes the flow path of the exhaust steam after driving the medium-pressure turbine 40b. Therefore, by rotating either one of the circular plates 58 and 59, the flow path area of the exhaust steam can be changed to adjust the pressure reduction amount of the exhaust steam.

[0084] <Modification of the heat utilization system according to Embodiment 1 of the present disclosure>

[0085] In Embodiment 1, the pressure regulating valve 62 was described as a single valve, but it is not limited to this mode. The pressure regulating valve 62 may also have the same structure as any one of the Figures 2 - 4 as a modification of the pressure reducing component 50.

[0086] In Embodiment 1, the discharge source of the discharged heating fluid is the gas turbine 20, but it is not limited to this mode. As long as it is a structure that discharges a fluid having a temperature capable of evaporating water into steam by heat exchange with water in the heat recovery device 30, any structure can be used as the discharge source. For example, a boiler, a gas engine, a solid oxide fuel cell, etc. can also be used as the discharge source, and their exhaust gases can be used as the heating fluid. Moreover, as examples of combinations of other discharge sources and heating fluids, a reactor in a chemical plant and the product after an exothermic reaction, a waste incinerator and combustion gas, a solar energy utilization heating device and a heat medium gas, a geothermal energy utilization heating device and a heat medium gas, a nuclear reactor and a heat medium gas, etc. can be cited. In addition, as the heat medium gas, helium, argon, carbon dioxide, nitrogen, etc. can be used.

[0087] (Embodiment 2)

[0088] Next, the heat utilization system of Embodiment 2 will be described. In the heat utilization system of Embodiment 2, as compared with Embodiment 1, the heat demand device 60 is changed to a device (carbon dioxide recovery device) that recovers carbon dioxide from the exhaust gas of the gas turbine 20. In addition, in Embodiment 2, the same reference numerals are given to the components that are the same as those in Embodiment 1, and their detailed descriptions are omitted.

[0089] <Structure of the heat utilization system of Embodiment 2 of the present disclosure>

[0090] As Figure 12 shown, in the heat utilization system 1 of Embodiment 2 of the present disclosure, as the fuel burned in the burner 22 of the gas turbine 20, the exhaust gas discharged from the iron-making facility 2 is used. The iron-making facility 2 has a smelting gasifier 3, and iron is made using coal and iron ore as raw materials in the smelting gasifier 3. Therefore, the exhaust gas discharged from the smelting gasifier 3 contains combustible components (such as carbon monoxide) and carbon dioxide. A fuel supply pipeline 12 may be connected to the smelting gasifier 3, and a compressor 25 for boosting the exhaust gas discharged from the smelting gasifier 3 may be provided on the fuel supply pipeline 12. In addition, a nitrogen supply pipeline 24 may be connected to the fuel supply pipeline 12. The calorific value of the fuel in the burner 22 can be adjusted by mixing nitrogen supplied from the nitrogen supply pipeline 24 into the fuel flowing in the fuel supply pipeline 12.

[0091] Embodiment 2 may also be configured with other structures the same as those in Embodiment 1, but as described below, a part of the structure of Embodiment 1 is changed to configure Embodiment 2. In the heat utilization system 1 of Embodiment 2 of the present disclosure, the steam turbine 40 only has a high-pressure turbine 40a. Therefore, in Embodiment 2, the high-pressure turbine 40a constitutes the first steam turbine, and there is no second steam turbine. The exhaust steam pipeline 51 is provided in a manner that connects the high-pressure turbine 40a and the heat demand device 60. In addition, in the heat recovery device 30, water exchanges heat with the exhaust gas, and thus water evaporates to generate two steams with different pressures. However, as described later, the steam with a higher pressure is supplied to the high-pressure turbine 40a to drive the high-pressure turbine 40a. Therefore, the steam with a higher pressure corresponds to the first steam. Similar to Embodiment 1, the steam with a lower pressure corresponds to the second steam.

[0092] The heat demand device 60 is a carbon dioxide recovery device 60b for recovering carbon dioxide from the exhaust gas discharged from the gas turbine 20, specifically, the exhaust gas that has undergone heat exchange with water in the heat recovery device 30. The carbon dioxide recovery device 60b includes: a cooling tower 100 that cools the exhaust gas flowing out from the heat recovery device 30; an absorption tower 101 that causes an absorption liquid to absorb the carbon dioxide contained in the exhaust gas cooled in the cooling tower 100; a regeneration tower 102 that releases carbon dioxide by heating the absorption liquid that has absorbed carbon dioxide in the absorption tower 101; and a reboiler 103 that is used to heat the absorption liquid in the regeneration tower 102. An exhaust gas pipeline 29 is connected to the cooling tower 100. In addition, in the carbon dioxide recovery device 60b, the cooling tower 100 is not an essential structure, and when the temperature of the exhaust gas flowing out from the heat recovery device 30 is sufficiently low and the concentration of solid components such as sulfur oxides and dust contained in the exhaust gas is sufficiently low, the cooling tower 100 may be omitted. When the carbon dioxide recovery device 60b does not include the cooling tower 100, the heat recovery device 30 and the absorption tower 101 communicate with each other via the exhaust gas pipeline 29.

[0093] The other end of the exhaust steam pipeline 51, one end of which is connected to the high-pressure turbine 40a, is connected to the reboiler 103, whereby the high-pressure turbine 40a and the reboiler 103 communicate with each other. In addition, the heat recovery device 30 and the reboiler 103 communicate with each other via a water supply pipeline 104. A pressure regulating valve 62 and a water supply pump 105 provided downstream of the pressure regulating valve 62 are provided in the water supply pipeline 104.

[0094] The absorption tower 101 and the regeneration tower 102 communicate with each other through a rich absorption liquid pipeline 110 and a lean absorption liquid pipeline 111. The rich absorption liquid pipeline 110 is connected to the bottom of the absorption tower 101 and a position above the bottom of the regeneration tower 102, and the lean absorption liquid pipeline 111 is connected to the bottom of the regeneration tower 102 and a position above the bottom of the absorption tower 101. As will be described later, a rich absorption liquid containing a lot of carbon dioxide, that is, a rich absorption liquid, flows in the rich absorption liquid pipeline 110, and a lean absorption liquid that releases carbon dioxide from the rich absorption liquid and has a relatively lower carbon dioxide content rate than the rich absorption liquid flows in the lean absorption liquid pipeline 111. A heat exchanger 112 is provided to exchange heat between the rich absorption liquid flowing in the rich absorption liquid pipeline 110 and the lean absorption liquid flowing in the lean absorption liquid pipeline 111. In the rich absorption liquid pipeline 110, a rich absorption liquid pump 113 is provided between the absorption tower 101 and the heat exchanger 112. In the lean absorption liquid pipeline 111, a lean absorption liquid pump 114 is provided between the regeneration tower 102 and the heat exchanger 112.

[0095] At the top of the absorption tower 101, an exhaust gas pipeline 122 is connected for discharging the gas in the absorption tower 101 to the atmosphere. The regeneration tower 102 is provided with a circulation pipeline 115, and the absorption liquid circulates in this circulation pipeline, so that the absorption liquid in the regeneration tower 102 is drawn out from the bottom of the tower and returned to the regeneration tower 102 again. The circulation pipeline 115 is arranged in such a way as to pass through the reboiler 103. At the top of the regeneration tower 102, an outflow pipeline 120 is connected for allowing the gas in the regeneration tower 102, that is, the gas containing carbon dioxide released from the absorption liquid, to flow out of the regeneration tower 102. A booster 121 for boosting the pressure of the gas can also be provided in the outflow pipeline 120.

[0096] Details will be described later, but in Embodiment 2, in the reboiler 103 of the carbon dioxide recovery device 60b which is a heat demand device 60, the mixed vapor of the exhaust vapor discharged from the high-pressure turbine 40a and the second vapor exchanges heat with the absorption liquid and the absorption liquid is heated. Therefore, the reboiler 103 is equivalent to a heat exchange mechanism for heating the absorption liquid which is a body to be heated.

[0097] <Operation (heat utilization method) of the heat utilization system of Embodiment 2 of the present disclosure>

[0098] Next, the operation of the heat utilization system 1 of Embodiment 2 of the present disclosure will be described. Through the iron-making operation in the iron-making device 2, exhaust gas is discharged from the smelting gasifier 3. The exhaust gas discharged from the smelting gasifier 3 is supplied as fuel to the burner 22 of the gas turbine 20 via the fuel supply pipeline 12. When a compressor 25 is provided on the fuel supply pipeline 12, the exhaust gas is boosted by the compressor 25 and supplied to the burner 22. The operations of the gas turbine 20 and the power generation device 26 are the same as those in Embodiment 1.

[0099] In the heat recovery device 30, in the same manner as in Embodiment 1, the exhaust gas of the gas turbine 20 is cooled by exchanging heat with water. The cooled exhaust gas flows in the exhaust gas pipeline 29 and flows into the cooling tower 100 of the carbon dioxide recovery device 60b. When the cooling tower 100 does not exist in the carbon dioxide recovery device 60b, the exhaust gas flows into the absorption tower 101.

[0100] The water heated by exchanging heat with the exhaust gas in the heat recovery device 30 flows out of the heat recovery device 30 as the first vapor and the second vapor with different pressures respectively. The first vapor is supplied to the high-pressure turbine 40a via the vapor supply pipeline 31 and drives the high-pressure turbine 40a. The power generation device 41 is driven by the high-pressure turbine 40a to generate electricity. On the other hand, the second vapor flows in the second vapor pipeline 32. When the exhaust vapor discharged from the high-pressure turbine 40a after driving the high-pressure turbine 40a flows in the exhaust vapor pipeline 51, it mixes with the second vapor flowing in the second vapor pipeline 32 and flows into the reboiler 103 of the carbon dioxide recovery device 60b.

[0101] As described later, the mixed vapor of the exhaust vapor and the second vapor flowing into the reboiler 103 is cooled by exchanging heat with the lean absorbent liquid flowing in 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. Thus, by keeping the pressure in the reboiler 103 sufficiently high, a sufficient vapor density and a sufficient heat conductivity can be obtained, whereby the required heat can be provided, and further, the vapor can be condensed at the temperature required in the reboiler 103. The mixed vapor that has exchanged heat with the lean absorbent liquid in the reboiler 103 condenses into water, flows through the water supply line 104 by the water supply pump 105, and then is supplied to the heat recovery device 30 to exchange heat with the exhaust gas.

[0102] As described above, when the exhaust gas flowing into the cooling tower 100 rises in the cooling tower 100, it is cooled by gas-liquid contact with the cooling water falling in the cooling tower 100. When sulfur oxides or solid components are contained in the exhaust gas, the sulfur oxides or solid components are captured by the cooling water through the gas-liquid contact between the exhaust gas and the cooling water, and the sulfur oxides or solid components are removed from the exhaust gas.

[0103] The exhaust gas flowing out of the cooling tower 100 flows into the absorption tower 101. In the absorption tower 101, the exhaust gas rises and the lean absorbent liquid falls, whereby the exhaust gas and the lean absorbent liquid are in gas-liquid contact, and the carbon dioxide contained in the exhaust gas is absorbed by the lean absorbent liquid. By absorbing carbon dioxide, the lean absorbent liquid becomes a rich absorbent liquid and stays at the bottom of the absorption tower 101. Through such an operation, at least a part of the carbon dioxide is removed from the exhaust gas, and the exhaust gas with a reduced carbon dioxide concentration flows out from the top of the absorption tower 101 and is discharged into the atmosphere via the exhaust pipe line 122. Alternatively, the exhaust pipe line 122 may be connected to other equipment such as a chimney, and the exhaust gas with a reduced carbon dioxide concentration may be discharged via the chimney.

[0104] The rich absorbent liquid in the absorption tower 101 is pumped out from the bottom of the absorption tower 101 by the rich absorbent liquid pump 113 and flows in the rich absorbent liquid pipeline 110. The rich absorbent liquid flowing in the rich absorbent liquid pipeline 110 is heated by heat exchange with the lean absorbent liquid flowing in the lean absorbent liquid pipeline 111 in the heat exchanger 112 as described later, and then flows into the regeneration tower 102. The rich absorbent liquid flowing into the regeneration tower 102 falls in the regeneration tower 102. When the rich absorbent liquid falls in the regeneration tower 102, it is heated by contact with the saturated vapor generated in the subsequent operation and rising in the regeneration tower 102. Thereby, at least a part of carbon dioxide is released from the rich absorbent liquid, and the rich absorbent liquid becomes lean absorbent liquid and stays at the bottom of the regeneration tower 102. The lean absorbent liquid in the regeneration tower 102 is pumped out from the bottom of the regeneration tower 102 and flows in the circulation pipeline 115 and returns to the inside of the regeneration tower 102 again. When the lean absorbent liquid flows in the circulation pipeline 115, the lean absorbent liquid exchanges heat with the mixed vapor in the reboiler 103, whereby the lean absorbent liquid is heated. Thereby, the temperature of the lean absorbent liquid in the regeneration tower 102 rises, so carbon dioxide is released from the lean absorbent liquid and water evaporates, and the saturated vapor mainly containing carbon dioxide and water vapor rises in the regeneration tower 102. In addition, the circulation of the lean absorbent liquid via the circulation pipeline 115 can be carried out by using a pump (not shown) provided in the circulation pipeline 115, or can be carried out without setting a pump by the density difference of the absorbent liquid.

[0105] The lean absorbent liquid in the regeneration tower 102 is also pumped out from the bottom of the regeneration tower 102 by the lean absorbent liquid pump 114 and flows in the lean absorbent liquid pipeline 111. The lean absorbent liquid flowing in the lean absorbent liquid pipeline 111 is cooled by heat exchange with the rich absorbent liquid flowing in the rich absorbent liquid pipeline 110 in the heat exchanger 112. The lean absorbent liquid cooled in the heat exchanger 112 flows into the absorption tower 101 as described above and falls in the absorption tower 101.

[0106] The gas containing carbon dioxide released from the rich absorbent liquid and the lean absorbent liquid in the regeneration tower 102 flows out from the top of the regeneration tower 102 and flows in the outflow pipeline 120. The gas flowing in the outflow pipeline 120 is boosted by the booster 121, and thus is supplied to the equipment that consumes carbon dioxide or the equipment that stores carbon dioxide (both not shown).

[0107] Thus, similar to the first embodiment, in the second embodiment, not only the exhaust vapor which is the vapor after driving the high-pressure turbine 40a, but also the second vapor supplied from the heat recovery device 30 can be used as the heat source in the reboiler 103 of the carbon dioxide recovery device 60b, so sufficient heat can be supplied to the reboiler 103.

[0108] In the carbon dioxide recovery apparatus 60b, the heat required for the reboiler 103 varies according to the amount of carbon dioxide recovered. In this regard, in the second embodiment, as in the first embodiment, the heat supplied to the reboiler 103 can be controlled by changing the opening degree of the pressure regulating valve 50a. The specific control method is the same as the control method described in the first embodiment. Thus, the heat supplied to the carbon dioxide recovery apparatus 60b can be controlled based on the heat demand in the carbon dioxide recovery apparatus 60b.

[0109] In the second embodiment, the carbon dioxide recovery apparatus 60b recovers carbon dioxide from the exhaust gas discharged from the gas turbine 20. Therefore, even if the exhaust gas discharged from the iron-making facility 2 is used as fuel for the gas turbine 20, the carbon dioxide generated in the iron-making facility 2 and the gas turbine 20 can be recovered. In the exhaust gas discharged from the iron-making facility 2, in addition to the carbon dioxide generated when coal is used to reduce iron ore, carbon dioxide is also generated when carbon monoxide and the like contained in the exhaust gas discharged from the iron-making facility 2 are burned in the burner 22 of the gas turbine 20. Therefore, the exhaust gas discharged from the gas turbine 20 that uses the exhaust gas discharged from the iron-making facility 2 as fuel contains carbon dioxide at a higher concentration than the exhaust gas discharged from a general gas turbine that uses a fuel such as natural gas. Therefore, in order to recover carbon dioxide from the exhaust gas discharged from the gas turbine 20 that uses the exhaust gas discharged from the iron-making facility 2 as fuel, a large amount of heat is required compared to recovering carbon dioxide from the exhaust gas discharged from a general gas turbine. In this regard, if the invention of the present disclosure is used, the heat supplied to the carbon dioxide recovery apparatus 60b can be increased, and the carbon dioxide in the exhaust gas can be sufficiently recovered even in the gas turbine 20 that uses the exhaust gas discharged from the iron-making facility 2 as fuel.

[0110] <Modification example of the heat utilization system according to the second embodiment of the present disclosure>

[0111] In the second embodiment, the heat used to heat the lean absorbent liquid in the reboiler 103 is the heat recovered from the exhaust gas of the gas turbine 20 in the heat recovery device 30, but it is not limited to this heat. As Figure 13As shown, in the gas turbine 20, generally, the cooling air obtained by cooling a part of the compressed air is used to cool the inside of the burner 22, the stationary blades 130 of the turbine 23, the turbine rotor 131, the moving blades 132 of the turbine rotor 131, etc. Therefore, 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 the water supplied from the reboiler 103. Through this heat exchange, the compressed air is cooled and the water is heated. The air cooler 133 may, for example, also have a structure including a cooler 133a for modulating the cooling air for cooling the inside of the burner 22, a cooler 133b for modulating the cooling air for cooling the stationary blades 130 of the turbine 23, and a cooler 133c for modulating the 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 can be supplied to the reboiler 103, or can be mixed with the water that has exchanged heat with the exhaust gas in the heat recovery device 30 (refer to Figure 12 ) and then supplied to the reboiler 103 after being heated.

[0112] In the second embodiment, as described above, similar to the first embodiment, the steam turbine 40 may have a structure including a medium-pressure turbine 40b (refer to Figure 1 ) and a low-pressure turbine 40c (refer to Figure 1 ) in addition to the high-pressure turbine 40a, or the steam turbine 40 may have a structure including the high-pressure turbine 40a and the medium-pressure turbine 40b. In these structures, similar to the first embodiment, the medium-pressure turbine 40b becomes the first steam turbine.

[0113] In the second embodiment, as the fuel burned in the burner 22 of the gas turbine 20, the exhaust gas discharged from the iron-making facility 2 is used, but it is not limited to this method. As a supply source for supplying fuel to the burner 22 of the gas turbine 20, any fuel generation device that generates a gas containing combustible components (such as carbon monoxide or hydrocarbons) and carbon dioxide as exhaust gas or a product can be provided. The iron-making facility 2 of the second embodiment is an example of a fuel generation device. In addition to this, as a fuel generation device, a gasifier that gasifies coal or biomass fuel to obtain a gas containing hydrogen and carbon monoxide, a reforming reaction device that adds steam to hydrocarbons and heats them to obtain a gas containing hydrogen and carbon monoxide, etc. can also be used.

[0114] (Third Embodiment)

[0115] Next, the heat utilization system of Embodiment 3 will be described. In the heat utilization system of Embodiment 3, compared with Embodiment 1, the heat demand device 60 is changed to a gasification device used in a chemical plant or the like. In addition, in Embodiment 3, the same reference numerals are assigned to the components that are the same as those in Embodiment 1, and their detailed descriptions are omitted.

[0116] <Structure of the heat utilization system of Embodiment 3 of the present disclosure>

[0117] As Figure 14 shown, in the heat utilization system 1 of Embodiment 3 of the present disclosure, the heat demand device 60 is a gasification device 60c for gasifying a liquid substance (for example, ammonia or methanol, etc.), which is a raw material used in a chemical plant or the like. The gasification device 60c includes a heat exchange mechanism 60c1 that exchanges heat between the liquid substance as the object to be heated and the first vapor and the second vapor. The gasification device 60c may also include a tank 60c2 for storing the liquid substance and a pump 60c3 for supplying the liquid substance in the tank 60c2 to the heat exchange mechanism 60c1.

[0118] Embodiment 3 may also be configured with other structures the same as those in Embodiment 1, but Embodiment 3 is configured by changing the structure of Embodiment 1 as described below. In the heat utilization system 1 of Embodiment 3 of the present disclosure, the steam turbine 40 only has a high-pressure turbine 40a and a medium-pressure turbine 40b. Except for the peripheral structural components that do not exist due to the absence of the low-pressure turbine 40c (refer to Figure 1 ) and the condenser 71 (refer to Figure 1 ), the non-existence of the heat demand device inlet valve 52 (refer to Figure 1 ) and the on-off valve (refer to Figure 1 ), and the discharge pipeline 61 connecting the gasification device 60c to the heat recovery device 30, the other structures are the same as those in Embodiment 1. In Embodiment 3, similar to Embodiment 1, the medium-pressure turbine 40b corresponds to the first steam turbine, but different from Embodiment 1, there is no second steam turbine.

[0119] <Operation (heat utilization method) of the heat utilization system of Embodiment 3 of the present disclosure>

[0120] Next, the operation of the heat utilization system 1 of Embodiment 3 of the present disclosure will be described. Except for the operation of utilizing the heat of the first vapor and the second vapor in the gasification device 60c, the operations of Embodiments 1 and 3 are the same, so only the different operations in the operations of Embodiments 1 and 3 will be described below.

[0121] The exhaust steam (first steam) discharged from the intermediate-pressure turbine 40b and the mixed steam of the second steam from the heat recovery device 30 are supplied to the gasification device 60c. The mixed steam supplied to the gasification device 60c flows into the heat exchange mechanism 60c1 and exchanges heat with the liquid substance supplied from the tank 60c2 by the pump 60c3. Through the heat exchange in the heat exchange mechanism 60c1, the liquid substance is heated and vaporized and supplied to a reaction device (not shown). On the other hand, 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 regulating valve 62. Thus, by maintaining the pressure in the heat exchange mechanism 60c1 sufficiently high, a sufficient steam density and a sufficient heat conductivity can be obtained, whereby the required heat can be provided, and further, the steam can be condensed at the temperature required by the heat exchange mechanism 60c1. The water formed by the condensation of the mixed steam flows through the discharge pipeline 61 by the pump 63 and is supplied to the heat recovery device 30.

[0122] Thus, similar to the first embodiment, in the third 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 utilized as the heat source in the heat exchange mechanism 60c1 of the gasification device 60c. Therefore, sufficient heat can be supplied to the heat exchange mechanism 60c1.

[0123] In the gasification device 60c, the heat required by the heat exchange mechanism 60c1 varies according to the vaporization amount of the liquid substance. In this regard, in the third embodiment, similar to the first embodiment, the heat supplied to the heat exchange mechanism 60c1 can be controlled by changing the opening degree of the pressure regulating valve 50a. The specific control method is the same as the control method described in the first embodiment. Thus, the heat supplied to the gasification device 60c can be controlled based on the heat demand in the gasification device 60c.

[0124] The content described in each of the above embodiments can be grasped as follows, for example.

[0125] [1] A heat utilization system according to one aspect includes:

[0126] 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-exchanging a heating fluid with the water;

[0127] An exhaust source (gas turbine 20) that discharges the heating fluid;

[0128] A first steam turbine (high-pressure turbine 40a or intermediate-pressure turbine 40b) driven by the first steam;

[0129] A pressure reducing component (50) that reduces the pressure of the exhaust steam, which is the steam after driving the first steam turbine (40a or 40b);

[0130] A heat demand device (60) that utilizes the heat of at least a part of the exhaust steam and at least one of the second steam;

[0131] An exhaust steam pipeline (51) that connects the first steam turbine (40a or 40b) to the heat demand device (60); and

[0132] A second steam pipeline (32) through which the second steam flows out from the heat recovery device (30),

[0133] The second steam pipeline (32) is connected to the exhaust steam pipeline (51) downstream of the pressure reducing component (50).

[0134] In the heat utilization system according to 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 utilized as the heat source of the heat demand device. Therefore, sufficient heat can be supplied to the heat demand device.

[0135] [2] The heat utilization system of another embodiment is based on the heat utilization system of [1],

[0136] The heat demand device (60) includes a heat exchange mechanism (reboiler 103 / heat exchange mechanism 60c1), and the heat exchange mechanism (reboiler 103 / heat exchange mechanism 60c1) exchanges heat with a heated body through at least one of the exhaust steam and the second steam to heat the heated body.

[0137] According to such a structure, the heated body can be heated in the heat demand device.

[0138] [3] The heat utilization system of yet another embodiment is based on the heat utilization system of [2],

[0139] The heat demand device (60) is a vaporization device (60c) for vaporizing a liquid substance as the heated body.

[0140] According to such a structure, the liquid substance can be vaporized in the heat demand device.

[0141] [4] The heat utilization system of yet another embodiment is based on any one of the heat utilization systems of [1] to [3],

[0142] The heat utilization system includes a second steam turbine (low-pressure turbine 40c) driven by at least a part of the exhaust steam.

[0143] According to such a structure, when the heat demand in the heat demand device is small, in order to drive the second steam turbine, the exhaust steam that does not need to be used in the heat demand device can be used. Therefore, the power generation amount in the heat utilization system can be increased.

[0144] [5] The heat utilization system of yet another solution is based on any one of the heat utilization systems in [1] to [4],

[0145] Based on the heat demand in the above-mentioned heat demand device (60), the pressure reduction component (50) adjusts the amount of pressure reduction of the exhaust steam.

[0146] According to such a structure, when the pressure of the exhaust steam is reduced by the pressure reduction component, the output of the first steam turbine decreases, so the temperature of the exhaust steam rises. Therefore, when the heat demand in the heat demand device becomes larger, the amount of pressure reduction of the exhaust steam is adjusted by the pressure reduction component, whereby the exhaust steam with an increased temperature can be supplied to the heat demand device, and thus sufficient heat based on the heat demand in the heat demand device can be supplied to the heat demand device.

[0147] [6] The heat utilization system of yet another solution is based on the heat utilization system in [4],

[0148] The heat utilization system is provided with an exhaust steam supply amount adjustment component (heat demand device inlet valve 52 / low-pressure turbine inlet valve 55) for adjusting the supply amount of the exhaust steam supplied to the above-mentioned second steam turbine (40c),

[0149] Based on the heat demand in the above-mentioned heat demand device (60), the above-mentioned exhaust steam supply amount adjustment component (52 / 55) adjusts the supply amount of the exhaust steam supplied to the above-mentioned second steam turbine (40c), thereby adjusting the supply amount of the exhaust steam supplied to the above-mentioned heat demand device (60).

[0150] According to such a structure, it is possible to supply sufficient heat based on the heat demand in the heat demand device to the heat demand device by reducing the supply amount of the exhaust steam supplied to the second steam turbine and increasing the supply amount of the exhaust steam supplied to the heat demand device. In addition, when the heat demand in the heat demand device is small, it is possible to use the exhaust steam that is not required in the heat demand device to drive the second steam turbine by increasing the supply amount of the exhaust steam supplied to the second steam turbine, so the power generation amount in the heat utilization system can be increased.

[0151] [7] The heat utilization system of yet another solution is based on the heat utilization system in [4],

[0152] The heat utilization system is provided with an exhaust steam supply amount adjustment component (52 / 55) for adjusting the supply amount of the exhaust steam supplied to the above-mentioned second steam turbine (40c),

[0153] Based on the heat demand in the above heat demand device (60), the above exhaust steam supply amount adjusting member (52 / 55) stops the supply of the above exhaust steam to the above second steam turbine (40c), and the above pressure reducing member (50) adjusts the amount of pressure reduction of the above exhaust steam.

[0154] According to such a configuration, in a case where it is impossible to supply heat equivalent to the heat demand in the heat demand device to the heat demand device even without supplying exhaust steam to the second steam turbine, the amount of pressure reduction of the exhaust steam is adjusted by the pressure reducing member, whereby it is possible to supply the exhaust steam with an increased temperature to the heat demand device, and thus it is possible to supply sufficient heat based on the heat demand in the heat demand device to the heat demand device.

[0155] [8] Another heat utilization system is based on the heat utilization system in [2],

[0156] The above heat demand device (60) is a carbon dioxide recovery device (60b) for recovering carbon dioxide contained in the above heating fluid,

[0157] The above carbon dioxide recovery device (60b) includes:

[0158] An absorption tower (101) that causes the absorption liquid to absorb carbon dioxide by bringing the above heating fluid that has undergone heat exchange with the above water in the above heat recovery device (30) into contact with the absorption liquid; and

[0159] A regeneration tower (102) that heats the absorption liquid that has absorbed carbon dioxide in the above absorption tower (101) to release carbon dioxide from the absorption liquid,

[0160] The above heat exchange mechanism is a reboiler (103) for heating the absorption liquid in the above regeneration tower (102) that is the above heated object.

[0161] According to such a configuration, it is possible to recover carbon dioxide contained in the heating fluid by heating the absorption liquid in the regeneration tower in the carbon dioxide recovery device to release carbon dioxide from the absorption tower.

[0162] [9] Another heat utilization system is based on the heat utilization system in [8],

[0163] The above discharge source is a gas turbine (20),

[0164] The above gas turbine (20) includes: a compressor (21) that compresses air;

[0165] A burner (22) that burns fuel using the compressed air compressed by the above compressor (21);

[0166] A turbine (23) driven by combustion gas generated by burning the fuel in the burner (22); and

[0167] An air cooler (133) that cools a part of the compressed air by heat exchange between a part of the compressed air and a part of the water.

[0168] According to such a structure, in order to adjust the temperature of the cooling air for cooling the burner and the turbine of the gas turbine, the heat removed from the compressed air is used for heating the absorption liquid, so that the available heat of the carbon dioxide recovery device can be increased.

[0169]

[10] A heat utilization system according to another aspect is based on the heat utilization system of [8],

[0170] The discharge source is a gas turbine (20),

[0171] The gas turbine (20) includes:

[0172] A compressor (21) that compresses air;

[0173] A burner (22) that burns fuel using the compressed air compressed by the compressor (21); and

[0174] A turbine (23) driven by combustion gas generated by burning the fuel in the burner (22),

[0175] The heat utilization system (1) includes a fuel generation device (ironmaking device 2), and the fuel generation device (ironmaking device 2) generates a gas containing combustible components and carbon dioxide as exhaust gas or a product,

[0176] The fuel generation device (2) is configured to supply the gas as the fuel to the burner (22).

[0177] According to such a structure, the carbon dioxide recovery device recovers carbon dioxide from the gas discharged by the gas turbine. Therefore, even if the gas supplied from the fuel generation device is used as the fuel of the gas turbine, the carbon dioxide generated in the fuel generation device and the gas turbine can be recovered.

[0178]

[11] A heat utilization system according to one aspect includes:

[0179] A heat recovery device (30) that generates first steam from the water by heat exchange between a heating fluid and the water;

[0180] A discharge source (gas turbine 20) that discharges the heating fluid;

[0181] The first steam turbine (high-pressure turbine 40a or intermediate-pressure turbine 40b) is driven by the above-mentioned first steam;

[0182] A pressure reducing component (50) reduces the pressure of the exhaust steam, which is the steam after driving the above-mentioned first steam turbine (40a or 40b); and

[0183] A heat demand device (60) utilizes at least a part of the heat of the exhaust steam downstream of the above-mentioned pressure reducing component (50),

[0184] Based on the heat demand in the above-mentioned heat demand device (60), the pressure reducing component (50) adjusts the amount of pressure reduction of the exhaust steam.

[0185] In the heat utilization system according to the present disclosure, by increasing the amount of pressure reduction of the exhaust steam, the pressure at the inlet of the pressure reducing component, that is, the outlet of the first steam turbine, rises, the pressure expansion ratio of the first steam turbine decreases, and the output of the first steam turbine decreases. As a result, the temperature of the exhaust steam rises, so the amount of heat supplied to the heat demand device can be increased, and sufficient heat can be supplied to the heat demand device.

[0186]

[12] Another heat utilization system is based on the heat utilization system in

[11] ,

[0187] As the heat demand in the above-mentioned heat demand device (60) increases, the amount of pressure reduction based on the above-mentioned pressure reducing component (50) increases.

[0188] According to such a structure, when the heat demand in the heat demand device increases, the amount of pressure reduction of the exhaust steam is increased by the pressure reducing component, so that the temperature of the exhaust steam rises. Therefore, the amount of heat supplied to the heat demand device can be increased, and sufficient heat can be supplied to the heat demand device.

[0189]

[13] Another heat utilization system is based on the heat utilization system in

[11] or

[12] ,

[0190] As the heat demand in the above-mentioned heat demand device (60) increases, the flow path area of the exhaust steam in the above-mentioned pressure reducing component (50) is reduced.

[0191] According to such a structure, when the heat demand in the heat demand device increases, by reducing the flow path area of the exhaust steam in the pressure reducing component, the amount of pressure reduction of the exhaust steam increases, and the temperature of the exhaust steam rises. Therefore, the amount of heat supplied to the heat demand device can be increased, and sufficient heat can be supplied to the heat demand device.

[0192]

[14] Another heat utilization system is based on any one of the heat utilization systems in

[11] to

[13] ,

[0193] The heat utilization system includes:

[0194] A second steam turbine (low-pressure turbine 40c) driven by at least a part of the exhaust steam; and

[0195] An exhaust steam supply amount adjusting member (heat demand equipment inlet valve 52 / low-pressure turbine inlet valve 55) for adjusting the supply amount of the exhaust steam supplied to the second steam turbine (40c),

[0196] Based on the heat demand in the heat demand equipment (60), the exhaust steam supply amount adjusting member (52 / 55) adjusts the supply amount of the exhaust steam supplied to the second steam turbine (40c), thereby adjusting the supply amount of the exhaust steam supplied to the heat demand equipment (60).

[0197] According to such a structure, by reducing the supply amount of the exhaust steam supplied to the second steam turbine and increasing the supply amount of the exhaust steam supplied to the heat demand equipment, it is possible to supply sufficient heat based on the heat demand in the heat demand equipment to the heat demand equipment. In addition, when the heat demand in the heat demand equipment is small, it is possible to use the exhaust steam that is not required in the heat demand equipment to drive the second steam turbine by increasing the supply amount of the exhaust steam supplied to the second steam turbine, so the power generation amount in the heat utilization system can be increased.

[0198]

[15] On the basis of the heat utilization system in

[14] , another heat utilization system

[0199] Adjusts the supply amount of the exhaust steam supplied to the heat demand equipment (60) in a state where the pressure reduction amount in the pressure reduction member (50) is minimized.

[0200] According to such a structure, it is possible to meet the heat demand in the heat demand equipment without reducing the output of the first steam turbine.

[0201]

[16] On the basis of the heat utilization system in

[14] , another heat utilization system

[0202] Based on the heat demand in the heat demand equipment (60), the exhaust steam supply amount adjusting member (52 / 55) stops the supply of the exhaust steam to the second steam turbine (40c), and the pressure reduction member (50) adjusts the pressure reduction amount of the exhaust steam.

[0203] According to such a structure, when the heat demand in the heat demand equipment cannot be met even if the full amount of the exhaust steam is supplied to the heat demand equipment, the pressure reduction amount of the exhaust steam is increased by the pressure reduction member, whereby the temperature of the exhaust steam rises, so the amount of heat supplied to the heat demand equipment can be increased, and the heat demand of the heat demand equipment can be met.

[0204]

[17] The heat utilization system of another solution, based on the heat utilization system in

[16] ,

[0205] along with the increase in the heat demand in the above heat demand device (60), increases the pressure reduction amount based on the above pressure reduction component (50).

[0206] According to such a structure, when the heat demand in the heat demand device increases in the state where the entire amount of exhaust steam is supplied to the heat demand device, the pressure reduction amount of the exhaust steam is increased by the pressure reduction component, and thus the temperature of the exhaust steam rises. Therefore, the amount of heat supplied to the heat demand device can be increased, and the heat demand in the heat demand device can be satisfied.

[0207]

[18] The heat utilization system of another solution, based on the heat utilization system in

[14] ,

[0208] Based on the heat demand in the above heat demand device (60), the above exhaust steam supply amount adjustment component (52 / 55) stops the supply of the above exhaust steam to the above second steam turbine (40c), and adjusts the flow path area of the above exhaust steam in the above pressure reduction component (50).

[0209] According to such a structure, when the heat demand in the heat demand device cannot be satisfied even if the entire amount of exhaust steam is supplied to the heat demand device, the flow path area of the exhaust steam in the pressure reduction component is reduced to increase the pressure reduction amount of the exhaust steam, and thus the temperature of the exhaust steam rises. Therefore, the amount of heat supplied to the heat demand device can be increased, and the heat demand in the heat demand device can be satisfied.

[0210]

[19] The heat utilization system of another solution, based on the heat utilization system in

[18] ,

[0211] along with the increase in the heat demand in the above heat demand device, reduces the flow path area of the above exhaust steam in the above pressure reduction component.

[0212] According to such a structure, when the heat demand in the heat demand device increases in the state where the entire amount of exhaust steam is supplied to the heat demand device, the flow path area of the exhaust steam in the pressure reduction component is reduced to increase the pressure reduction amount of the exhaust steam, and thus the temperature of the exhaust steam rises. Therefore, the amount of heat supplied to the heat demand device can be increased, and the heat demand in the heat demand device can be satisfied.

[0213]

[20] The heat utilization system of another solution, based on the heat utilization system in

[11] ,

[0214] The above heat utilization system is provided with a heat supply amount control device (501),

[0215] The above heat supply amount control device (501) includes:

[0216] a receiving unit (511) that receives a heat demand signal, which is a signal related to the heat demand in the above heat demand device, from the above heat demand device;

[0217] a control signal generation unit (512) that generates a control signal for controlling the pressure reduction amount based on the above pressure reduction component (50) using the above heat demand signal; and

[0218] a control signal transmission unit (513) that transmits the above control signal to the above pressure reduction component (50).

[0219] According to such a configuration, the heat supply amount control device adjusts the pressure reduction amount based on the pressure reduction component according to the heat demand in the heat demand device, so that it can appropriately supply heat corresponding to the heat demand to the heat demand device.

[0220]

[21] On the basis of the heat utilization system in

[20] , the heat utilization system of another aspect

[0221] after the above control signal generation unit (512) detects an increase in the heat demand in the above heat demand device (60) based on the above heat demand signal, generates the above control signal for increasing the pressure reduction amount based on the above pressure reduction component (50).

[0222] According to such a configuration, when the heat demand in the heat demand device increases, the pressure reduction amount of the exhaust steam is increased by the pressure reduction component, so that the temperature of the exhaust steam rises. Therefore, the amount of heat supplied to the heat demand device can be increased, and sufficient heat can be supplied to the heat demand device.

[0223]

[22] On the basis of the heat utilization system in

[20] or

[21] , the heat utilization system of another aspect

[0224] after the above control signal generation unit (512) detects an increase in the heat demand in the above heat demand device (60) based on the above heat demand signal, generates the above control signal for reducing the flow path area of the above exhaust steam in the above pressure reduction component (50).

[0225] According to such a configuration, when the heat demand in the heat demand device increases, by reducing the flow path area of the exhaust steam in the pressure reduction component, the pressure reduction amount of the exhaust steam increases, and the temperature of the exhaust steam rises. Therefore, the amount of heat supplied to the heat demand device can be increased, and sufficient heat can be supplied to the heat demand device.

[0226]

[23] On the basis of any one of the heat utilization systems in

[20] to

[22] , the heat utilization system of another aspect

[0227] The above heat utilization system includes:

[0228] a second steam turbine (40c) driven by at least a part of the above exhaust steam; and

[0229] an exhaust steam supply amount adjusting member (52 / 55) for adjusting the supply amount of the above exhaust steam supplied to the above second steam turbine (40c),

[0230] The above heat supply amount control device (501) includes:

[0231] an adjustment signal generation unit (522) that uses the above heat demand signal to generate an adjustment signal for adjusting the supply amount of the above exhaust steam supplied to the above second steam turbine (40c); and

[0232] an adjustment signal transmission unit (523) that transmits the above adjustment signal to the above exhaust steam supply amount adjusting member (52 / 55),

[0233] The above exhaust steam supply amount adjusting member (52 / 55) adjusts the supply amount of the above exhaust steam supplied to the above second steam turbine (40c) based on the above adjustment signal.

[0234] According to such a configuration, by reducing the supply amount of the exhaust steam supplied to the second steam turbine and increasing the supply amount of the exhaust steam supplied to the heat demand device, it is possible to supply sufficient heat based on the heat demand in the heat demand device to the heat demand device. In addition, when the heat demand in the heat demand device is small, it is possible to use the exhaust steam that is not required in the heat demand device to drive the second steam turbine by increasing the supply amount of the exhaust steam supplied to the second steam turbine, so that the power generation amount in the heat utilization system can be increased.

[0235]

[24] On the basis of the heat utilization system in

[23] , the heat utilization system of another aspect

[0236] The above control signal generation unit (522) generates the above control signal that minimizes the pressure reduction amount based on the above pressure reduction member (50).

[0237] According to such a configuration, it is possible to meet the heat demand in the heat demand device without reducing the output of the first steam turbine.

[0238]

[25] On the basis of the heat utilization system in

[23] , the heat utilization system of another solution

[0239] The above adjustment signal generation unit (522) generates the above adjustment signal that stops the supply of the above exhaust steam to the above second steam turbine (40c).

[0240] According to such a configuration, when the priority of heat supply to the heat demand device is higher than the power generation amount in the heat utilization system, the second steam turbine is stopped, and all the exhaust steam is supplied to the heat demand device, thereby enabling the heat demand in the heat demand device with a higher priority to be satisfied.

[0241]

[26] The heat utilization system of still another embodiment is based on the heat utilization system of

[25] .

[0242] After detecting an increase in the heat demand in the heat demand device (60) based on the heat demand signal, the control signal generation unit (522) generates the control signal that increases the pressure reduction amount of the pressure reduction component (50).

[0243] According to such a configuration, when the heat demand in the heat demand device cannot be satisfied even if all the exhaust steam is supplied to the heat demand device, the pressure reduction amount of the exhaust steam is increased by the pressure reduction component, whereby the temperature of the exhaust steam rises. Therefore, the amount of heat supplied to the heat demand device can be increased, and the heat demand in the heat demand device can be satisfied.

[0244]

[27] The heat utilization system of still another embodiment is based on the heat utilization system of

[25] .

[0245] After detecting an increase in the heat demand in the heat demand device (60) based on the heat demand signal, the control signal generation unit (522) generates the control signal that reduces the flow path area of the exhaust steam in the pressure reduction component (50).

[0246] According to such a configuration, when the heat demand in the heat demand device cannot be satisfied even if all the exhaust steam is supplied to the heat demand device, the flow path area of the exhaust steam in the pressure reduction component is reduced to increase the pressure reduction amount of the exhaust steam, whereby the temperature of the exhaust steam rises. Therefore, the amount of heat supplied to the heat demand device can be increased, and the heat demand in the heat demand device can be satisfied.

[0247]

[28] A heat utilization method of one embodiment includes the following steps:

[0248] A step of discharging a heating fluid from a discharge source (gas turbine 20);

[0249] A step of generating first steam from the water by heat exchange between the heating fluid and the water;

[0250] A step of driving a first steam turbine (high-pressure turbine 40a or medium-pressure turbine 40b) by the first steam;

[0251] A step of reducing the pressure of the exhaust steam, which is the steam after driving the first steam turbine (40a or 40b); and

[0252] A step of supplying the above-described exhaust steam with reduced pressure to a heat demand device (60).

[0253] In the step of reducing the pressure of the above-described exhaust steam, the amount of pressure reduction of the above-described exhaust steam is adjusted based on the heat demand in the above-described heat demand device (60).

[0254] According to the heat utilization method of the present disclosure, by increasing the amount of pressure reduction of the exhaust steam, the pressure at the inlet of the pressure reduction component, i.e., the outlet of the first steam turbine, rises, the pressure expansion ratio of the first steam turbine decreases, and the output of the first steam turbine decreases. As a result, the temperature of the exhaust steam rises, so that the amount of heat supplied to the heat demand device can be increased, and sufficient heat can be supplied to the heat demand device.

[0255]

[29] The heat utilization method of another aspect is based on the heat utilization method of

[28] .

[0256] In the step of reducing the pressure of the above-described exhaust steam, as the heat demand in the above-described heat demand device (60) increases, the amount of pressure reduction is increased.

[0257] According to such a method, when the heat demand in the heat demand device increases, the temperature of the exhaust steam rises by increasing the amount of pressure reduction of the exhaust steam, so that the amount of heat supplied to the heat demand device can be increased, and sufficient heat can be supplied to the heat demand device.

[0258]

[30] The heat utilization method of yet another aspect is based on the heat utilization method of

[28] or

[29] .

[0259] In the step of reducing the pressure of the above-described exhaust steam, the pressure of the above-described exhaust steam is reduced by using a pressure reduction component (50).

[0260] In the step of reducing the pressure of the above-described exhaust steam, as the heat demand in the above-described heat demand device (60) increases, the flow path area of the above-described exhaust steam in the above-described pressure reduction component (50) is reduced.

[0261] According to such a method, when the heat demand in the heat demand device increases, the amount of pressure reduction of the exhaust steam increases by reducing the flow path area of the exhaust steam in the pressure reduction component, and the temperature of the exhaust steam rises, so that the amount of heat supplied to the heat demand device can be increased, and sufficient heat can be supplied to the heat demand device.

[0262]

[31] The heat utilization method of yet another aspect is based on any one of the heat utilization methods of

[28] to

[30] .

[0263] The above-described heat utilization method includes the following steps:

[0264] A step of supplying a part of the exhaust steam to a second steam turbine (40c) driven by the above-mentioned exhaust steam; and

[0265] A step of adjusting the supply amount of the exhaust steam supplied to the second steam turbine (40c) according to the heat demand in the above-mentioned heat demand device (60).

[0266] According to such a method, by reducing the supply amount of the exhaust steam supplied to the second steam turbine and increasing the supply amount of the exhaust steam supplied to the heat demand device, it is possible to supply sufficient heat based on the heat demand in the heat demand device to the heat demand device. In addition, when the heat demand in the heat demand device is small, it is possible to use the exhaust steam that does not need to be used in the heat demand device to drive the second steam turbine by increasing the supply amount of the exhaust steam supplied to the second steam turbine, so the power generation amount in the heat utilization system can be increased.

[0267] Explanation of reference numerals

[0268] 1 Heat utilization system

[0269] 2 Ironmaking equipment (fuel generation equipment)

[0270] 20 Gas turbine (exhaust source)

[0271] 21 Compressor

[0272] 22 Burner

[0273] 23 Turbine

[0274] 30 Heat recovery device

[0275] 32 Second steam pipeline

[0276] 40a High-pressure turbine (first steam turbine)

[0277] 40b Medium-pressure turbine (first steam turbine)

[0278] 40c Low-pressure turbine (second steam turbine)

[0279] 50 Pressure reducing component

[0280] 51 Exhaust steam pipeline

[0281] 52 Heat demand device inlet valve (exhaust steam supply amount adjusting component)

[0282] 55 Low-pressure turbine inlet valve (exhaust steam supply amount adjusting component)

[0283] 60 Heat demand device

[0284] 60b Carbon dioxide recovery device

[0285] 60c Gasification Equipment

[0286] 60c1 Heat Exchange Mechanism

[0287] 101 Absorption Tower

[0288] 102 Regeneration Tower

[0289] 103 Reboiler (Heat Exchange Mechanism)

[0290] 133 Air Cooler

[0291] 501 Heat Supply Control Device

[0292] 511 Receiving Section

[0293] 512 Control Signal Generation Section

[0294] 513 Control Signal Transmission Section

[0295] 522 Regulation Signal Generation Section

[0296] 523 Regulation Signal Transmission Section.

Claims

1. A heat utilization system, comprising: A heat recovery device that generates first vapor and second vapor having a pressure lower than that of the first vapor from the water by heat exchange between a heating fluid and the water; A discharge source that discharges the heating fluid; A first steam turbine driven by the first vapor; A pressure reducing component that reduces the pressure of the exhaust vapor, which is the vapor after driving the first steam turbine; A heat demand device that utilizes the heat of at least a part of the exhaust vapor and at least one of the second vapor; An exhaust vapor pipeline that connects the first steam turbine and the heat demand device; and A second steam pipeline through which the second vapor flows out from the heat recovery device, The second steam pipeline is connected to the exhaust vapor pipeline downstream of the pressure reducing component.

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

3. The heat utilization system according to claim 2, wherein, The heat demand device is a gasification device for gasifying a liquid substance as the object to be heated.

4. The heat utilization system according to claim 1 or 2, wherein, The heat utilization system includes a second steam turbine driven by at least a part of the exhaust vapor.

5. The heat utilization system according to claim 1 or 2, wherein, Based on the heat demand in the heat demand device, the pressure reducing component adjusts the amount of pressure reduction of the exhaust vapor.

6. The heat utilization system according to claim 4, wherein, The heat utilization system includes an exhaust vapor supply amount adjusting component for adjusting the supply amount of the exhaust vapor supplied to the second steam turbine, Based on the heat demand in the heat demand device, the exhaust vapor supply amount adjusting component adjusts the supply amount of the exhaust vapor supplied to the second steam turbine, thereby adjusting the supply amount of the exhaust vapor supplied to the heat demand device.

7. The heat utilization system according to claim 4, wherein, The heat utilization system includes an exhaust vapor supply amount adjusting component for adjusting the supply amount of the exhaust vapor supplied to the second steam turbine, Based on the heat demand in the heat demand device, the exhaust vapor supply amount adjusting component stops the supply of the exhaust vapor to the second steam turbine, and the pressure reducing component adjusts the amount of pressure reduction of the exhaust vapor.

8. The heat utilization system according to claim 2, wherein, The heat demand device is a carbon dioxide recovery device for recovering carbon dioxide contained in the heating fluid, The carbon dioxide recovery device includes: An absorption tower that causes the absorption liquid to absorb carbon dioxide by bringing the heating fluid that has undergone heat exchange with the water in the heat recovery device into contact with the absorption liquid; and A regeneration tower that heats the absorption liquid that has absorbed carbon dioxide in the absorption tower to release carbon dioxide from the absorption liquid, The heat exchange mechanism is a reboiler for heating the absorption liquid in the regeneration tower as the object to be heated.

9. The heat utilization system according to claim 8, wherein, the discharge source is a gas turbine, the gas turbine includes: a compressor for compressing air; a burner for burning fuel using the compressed air compressed by the compressor; a turbine driven by combustion gas generated by burning the fuel in the burner; and an air cooler for cooling a part of the compressed air by heat exchange between a part of the compressed air and a part of the water.

10. The heat utilization system according to claim 8, wherein, the discharge source is a gas turbine, the gas turbine includes: a compressor for compressing air; a burner for burning fuel using the compressed air compressed by the compressor; and a turbine driven by combustion gas generated by burning the fuel in the burner, the heat utilization system includes a fuel generation device that generates a gas containing a combustible component and carbon dioxide as exhaust gas or a product, the fuel generation device is configured to supply the gas as the fuel to the burner.

11. A heat utilization system, comprising: a heat recovery device for generating first steam from the 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 component for reducing the pressure of the exhaust steam after driving the first steam turbine; and a heat demand device for utilizing heat of at least a part of the exhaust steam downstream of the pressure reducing component, based on the heat demand in the heat demand device, the pressure reducing component adjusts the amount of pressure reduction of the exhaust steam.

12. The heat utilization system according to claim 11, wherein, as the heat demand in the heat demand device increases, the amount of pressure reduction based on the pressure reducing component increases.

13. The heat utilization system according to claim 11, wherein, as the heat demand in the heat demand device increases, the flow path area of the exhaust steam in the pressure reducing component decreases.

14. The heat utilization system according to any one of claims 11 to 13, wherein, the heat utilization system includes: a second steam turbine driven by at least a part of the exhaust steam; and an exhaust steam supply amount adjusting component for adjusting the supply amount of the exhaust steam supplied to the second steam turbine, based on the heat demand in the heat demand device, the exhaust steam supply amount adjusting component adjusts the supply amount of the exhaust steam supplied to the second steam turbine, thereby adjusting the supply amount of the exhaust steam supplied to the heat demand device.

15. The heat utilization system according to claim 14, wherein, in a state where the amount of pressure reduction in the pressure reducing component is minimized, the supply amount of the exhaust steam supplied to the heat demand device is adjusted.

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

17. The heat utilization system according to claim 16, wherein, as the heat demand in the heat demand device increases, the pressure reduction amount based on the pressure reduction component is increased.

18. The heat utilization system according to claim 14, wherein, Based on the heat demand in the heat demand device, the exhaust steam supply amount adjustment component stops the supply of the exhaust steam to the second steam turbine, and adjusts the flow path area of the exhaust steam in the pressure reduction component.

19. The heat utilization system according to claim 18, wherein, as the heat demand in the heat demand device increases, the flow path area of the exhaust steam in the pressure reduction component is reduced.

20. The heat utilization system according to claim 11, wherein, the heat utilization system includes a heat supply amount control device, the heat supply amount control device includes: a receiving unit that receives a heat demand signal, which is a signal related to the heat demand in the heat demand device, from the heat demand device; a control signal generation unit that uses the heat demand signal to generate a control signal for controlling the pressure reduction amount based on the pressure reduction component; and a control signal transmission unit that transmits the control signal to the pressure reduction component.

21. The heat utilization system according to claim 20, wherein, after detecting an increase in the heat demand in the heat demand device based on the heat demand signal, the control signal generation unit generates the control signal that increases the pressure reduction amount based on the pressure reduction component.

22. The heat utilization system according to claim 20, wherein, after detecting an increase in the heat demand in the heat demand device based on the heat demand signal, the control signal generation unit generates the control signal that reduces the flow path area of the exhaust steam in the pressure reduction component.

23. The heat utilization system according to any one of claims 20 to 22, wherein, the heat utilization system includes: a second steam turbine driven by at least a part of the exhaust steam; and an exhaust steam supply amount adjustment component for adjusting the supply amount of the exhaust steam supplied to the second steam turbine, the heat supply amount control device includes: an adjustment signal generation unit that uses the heat demand signal to generate an adjustment signal for adjusting the supply amount of the exhaust steam supplied to the second steam turbine; and an adjustment signal transmission unit that transmits the adjustment signal to the exhaust steam supply amount adjustment component, and the exhaust steam supply amount adjustment component adjusts the supply amount of the 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 generation unit generates the control signal that minimizes the pressure reduction amount based on the pressure reduction component.

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

26. The heat utilization system according to claim 25, wherein, after detecting an increase in the heat demand in the heat demand device based on the heat demand signal, the control signal generation unit generates the control signal for increasing the pressure reduction amount based on the pressure reduction component.

27. The heat utilization system according to claim 25, wherein, after detecting an increase in the heat demand in the heat demand device based on the heat demand signal, the control signal generation unit generates the control signal for reducing the flow path area of the exhaust steam in the pressure reduction component.

28. A heat utilization method includes the following steps: a step of discharging a heating fluid from a discharge source; a step of generating first steam from the water by heat exchange between the heating fluid and the water; a step of driving a first steam turbine by the first steam; a step of reducing the pressure of the exhaust steam, which is the steam after driving the first steam turbine; and a step of supplying the exhaust steam with reduced pressure to a heat demand device, in the step of reducing the pressure of the exhaust steam, the pressure reduction amount of the exhaust steam is adjusted based on the heat demand in the heat demand device.

29. The heat utilization method according to claim 28, wherein, in the step of reducing the pressure of the exhaust steam, the pressure reduction amount is increased along with an increase in the heat demand in the heat demand device.

30. The heat utilization method according to claim 28, wherein, in the step of reducing the pressure of the exhaust steam, the pressure of the exhaust steam is reduced using a pressure reduction component, in the step of reducing the pressure of the exhaust steam, the flow path area of the exhaust steam in the pressure reduction component is reduced along with an increase in the heat demand in the heat demand device.

31. The heat utilization method according to any one of claims 28 to 30, wherein, the heat utilization method includes the following steps: a step of supplying a part of the exhaust steam to a second steam turbine driven by the exhaust steam; and a step of adjusting the supply amount of the exhaust steam supplied to the second steam turbine according to the heat demand in the heat demand device.

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