JP2015047564A - Power generating system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To efficiently utilize construction of a power generating system, and to suppress adherence of marine organisms.SOLUTION: The power generating system includes: a power generating unit for generating power by combustion of fuel including carbon; a sea water circulation device that has a gas duct through which exhaust gas generated on the power generating unit flows, and a pump, and that feeds sea water using the pump, and circulates sea water between sea and the power generating unit; and a dissolving device for causing carbon dioxide to dissolve in sea water flowing downstream of the pump of the sea water circulation device. The dissolving device includes: an absorption tower through which at least part of the exhaust gas flowing in an area of an atmospheric air pressure atmosphere of the gas duct flows; and a spray part for spraying sea water flowing in the sea water circulation device into the absorption tower and being inserted into the absorption tower. The dissolving device further includes a dissolving module for causing carbon dioxide in the exhaust gas to dissolve in the sea water sprayed into the absorption tower.

Description

  The present invention relates to a power generation system having a dissolving device for dissolving oxygen dioxide in seawater flowing through a pipeline.

  Among the power generation systems installed adjacent to the sea, there is a power generation system that takes in seawater as cooling water and uses it. Seawater intake and discharge facilities that take in seawater have a problem that marine organisms adhere to pipes through which the seawater flows. As described in Patent Documents 1 and 2, as a method for preventing marine organisms from adhering to the pipe, there is a method in which carbon dioxide is dissolved in seawater to make the pH of the seawater a weak acid.

Japanese Patent Laid-Open No. 11-319853 JP 2011-14870 A

  When dissolving carbon dioxide bubbles mixed with air, the dissolution rate of carbon dioxide is proportional to the partial pressure of carbon dioxide, so the carbon dioxide partial pressure in the bubbles decreases with the dissolution of carbon dioxide, so the dissolution rate and efficiency of carbon dioxide However, it is difficult to completely dissolve carbon dioxide. In addition, if air or undissolved carbon dioxide bubbles stay in the pipe, there is a problem that the flow of the taken seawater is hindered.

  For this reason, in the methods described in Patent Documents 1 and 2, a cylinder gas filled with 100% carbon dioxide is used. Since the cylinder gas filled with 100% carbon dioxide is provided separately from the power generation system, there is room for improvement as a power generation system.

  The present invention solves the above-described problems, and an object thereof is to provide a power generation system that can efficiently use the configuration of the power generation system and suppress adhesion of marine organisms.

  In order to achieve the above object, a power generation system according to the present invention includes a power generation unit that generates power by burning fuel containing carbon, a flue through which exhaust gas generated in the power generation unit flows, and a pump. A seawater circulation device that feeds seawater and circulates the seawater between the power generation unit and the sea, and a dissolution device that dissolves carbon dioxide in seawater flowing downstream from the pump of the seawater circulation device, The melting device includes an absorption tower in which at least a part of the exhaust gas flowing in an area of an atmospheric pressure atmosphere of the flue flows, and at least a part of the seawater that is inserted into the absorption tower and flows in the seawater circulation device. And a melting module for dissolving carbon dioxide in the exhaust gas in the seawater sprayed in the absorption tower.

  Therefore, carbon dioxide can be dissolved in seawater using exhaust gas generated by burning fuel in the power generation unit and flowing in an atmospheric pressure atmosphere. As a result, carbon dioxide can be dissolved in seawater without preparing new power or a carbon dioxide supply source, so the configuration of the power generation system can be used efficiently and the attachment of marine organisms can be suppressed. be able to.

  In the power generation system of the present invention, the melting device connects the seawater circulation device and the melting module, and supplies a part of seawater flowing through the seawater circulation device to the melting module; and the seawater circulation device A discharge pipe for connecting the part of the seawater flow direction downstream side of the supply pipe to the dissolution module and discharging the seawater that has passed through the dissolution module to the seawater circulation device, and the seawater circulation device After the carbon dioxide is dissolved in a part of the seawater flowing through the seawater, the seawater in which the carbon dioxide is dissolved is discharged to the seawater circulation device.

  Therefore, seawater with an appropriate flow rate can be supplied to the melting module, and a large load on the melting module can be suppressed. Moreover, the enlargement of the melting module can be suppressed.

  In the power generation system of the present invention, the melting module is installed in the flue.

  Therefore, piping for guiding the exhaust gas to the melting module is not necessary, and the apparatus configuration is simplified.

  The power generation system of the present invention has a first flow rate adjustment valve disposed between the supply pipe and the discharge pipe of the seawater circulation device, and a second flow rate adjustment valve disposed in the supply pipe. And a controller for adjusting the flow rate of the seawater supplied to the dissolving device by adjusting the opening of the first flow rate adjustment valve and the second flow rate adjustment valve.

  Therefore, seawater with an appropriate flow rate can be supplied to the melting module, and the amount of carbon dioxide dissolved in seawater can be made more appropriate. Thereby, the pH value of seawater can be adjusted more accurately.

  The power generation system of the present invention further includes an exhaust gas treatment device that is disposed in the flue and reduces impurities contained in the exhaust gas, and the melting device converts carbon dioxide in the exhaust gas that has passed through the exhaust gas treatment device to the carbon dioxide in the exhaust gas. It is characterized by being dissolved in seawater.

  Therefore, it can suppress that an impurity mixes in seawater.

  In the power generation system of the present invention, the power generation unit further includes a steam turbine, and further includes a heat exchanger that cools the heat medium that has passed through the steam turbine with the seawater, and the seawater circulation device is provided in the heat exchanger. A water intake pipe that supplies the seawater; and a water discharge pipe that discharges the seawater that has passed through the heat exchanger, and the melting device dissolves carbon dioxide in the exhaust gas in the seawater that flows through the water intake pipe. It is characterized by that.

  Accordingly, it is possible to reduce the risk of marine organisms adhering to the path through which the seawater of the heat exchanger flows.

  According to the present invention, carbon dioxide can be dissolved in seawater using exhaust gas generated by burning fuel in a power generation unit and flowing in an atmospheric pressure atmosphere. As a result, carbon dioxide can be dissolved in seawater without preparing new power or a carbon dioxide supply source, so the configuration of the power generation system can be used efficiently and the attachment of marine organisms can be suppressed. be able to.

FIG. 1 is a schematic diagram illustrating a part of an overview of the power generation system according to the first embodiment of the present invention. FIG. 2 is a schematic diagram illustrating a schematic configuration of the power generation system according to the first embodiment of the present invention. FIG. 3 is a schematic diagram illustrating a schematic configuration of the melting module. FIG. 4 is a schematic diagram illustrating a schematic configuration of the power generation system according to the second embodiment of the present invention.

  Exemplary embodiments of a power generation system according to the present invention will be described below in detail with reference to the accompanying drawings. In addition, this invention is not limited by this Example, Moreover, when there exists multiple Example, what comprises combining each Example is also included.

  FIG. 1 is a schematic diagram illustrating a part of an overview of the power generation system according to the first embodiment of the present invention. FIG. 2 is a schematic diagram illustrating a schematic configuration of the power generation system according to the first embodiment of the present invention. FIG. 3 is a schematic diagram illustrating a schematic configuration of the melting module.

  As shown in FIG. 1, the power generation system 1 includes a steam turbine building 2, a heat exchanger 4, a seawater circulation device 6, a melting device 20, and an aeration device 22. As will be described later, the power generation system 1 includes various devices illustrated in FIG. 2 in addition to the components illustrated in FIG. 1. In the power generation system 1, the heat exchanger 4 is disposed in the steam turbine building 2. A seawater circulation device 6 that circulates seawater between the heat exchanger 4 and the sea is connected to the heat exchanger 4.

  The seawater circulation device 6 includes a water intake pipe 13, a pump 14, and a water discharge pipe 17. The intake pipe 13 is a pipe that connects the sea and the heat exchanger 4. One end of the intake pipe 13 is disposed in the sea surrounded by the intake channel 8, and the other end is connected to the heat exchanger 4. The pump 14 is attached to the intake pipe 13, sucks seawater in the intake path 8 into the intake pipe 13, and sends seawater from the intake path 8 to the heat exchanger 4 in the intake pipe 13. The water discharge pipe 17 is a pipe connecting the sea and the heat exchanger 4. One end of the water discharge pipe 17 is connected to the heat exchanger 4 and the other end is disposed in the sea. The dissolving device 20 dissolves carbon dioxide in seawater flowing through the intake pipe 13. The air diffuser 22 is provided in the water discharge pipe 17 and releases carbon dioxide from seawater flowing through the water discharge pipe 17. Detailed configurations of the dissolving device 20 and the air diffuser 22 will be described later.

The power generation system 1 takes in seawater containing plankton larvae into a water intake pipe 13 by a pump 14. In the power generation system 1, carbon dioxide (CO ₂ ) is dissolved in seawater flowing through the intake pipe 13 by the dissolving device 20 so that the pH of the seawater flowing through the intake pipe 13 is 6 or less, preferably 5 or more and 6 or less. The power generation system 1 supplies seawater in which carbon dioxide is dissolved to the heat exchanger 4, and discharges the seawater that has passed through the heat exchanger 4 from the water discharge pipe 17. Further, the power generation system 1 removes CO ₂ injected into the seawater by the air diffuser 22 in the vicinity of the outlet of the water discharge pipe 17 and returns the seawater returned to the pH of normal seawater from the water discharge pipe 17. To the sea.

  Next, the melting device 20 and the air diffuser 22 of the power generation system 1 will be described in more detail with reference to FIG. First, the power generation system 1 includes a power generation unit 30, a flue 38, an exhaust gas treatment device 40, and a chimney 42 in addition to the above configuration.

  The power generation unit 30 is a mechanism that generates power by converting heat generated by burning fuel into electric power, and includes a boiler 32, a steam turbine 34, and a heat medium circulation line 36. The boiler 32 burns fuel to generate combustion gas. Here, as fuel, various fuels, such as natural gas (LNG), petroleum, coal, biomass, alcohol, can be used, for example. The solid fuel is preferably pulverized and supplied as powder into the boiler 32. The boiler 32 has a heat medium circulation line 36 inserted therein, and heats the heat medium flowing through the heat medium circulation line 36 with combustion gas to produce steam. The combustion gas generated in the boiler 32 exchanges heat with the heat medium circulation line 36 and is then discharged to the flue 38 as exhaust gas. The steam turbine 34 is supplied with steam flowing through the heat medium circulation line 36 and is rotated by the supplied steam. The steam turbine 34 is connected to a generator. The generator generates power by rotating the generator by the rotation of the steam turbine 34.

  The heat medium circulation line 36 is a pipe that circulates the heat medium, and is connected to the boiler 32, the steam turbine 34, and the heat exchanger 4. In the heat medium circulation line 36, the heat medium flows in the order of the boiler 32, the steam turbine 34, and the heat exchanger 4, and is further circulated by supplying the heat medium that has passed through the heat exchanger 4 to the boiler 32. The heat medium flowing through the heat medium circulation line 36 is heated by the boiler 32 to become steam, and then supplied to the steam turbine 34 to rotate the steam turbine 34. The heat medium that has passed through the steam turbine 34 is cooled by heat exchange with the seawater in the heat exchanger 4 and becomes liquid. That is, the heat exchanger 4 becomes a condenser. The heat medium that has become liquid in the heat exchanger 4 is supplied to the boiler 32 again.

  The flue 38 has one end connected to the boiler 32 and the other end connected to the chimney 42, and exhausts the exhaust gas discharged from the boiler 32 from the chimney 42. The exhaust gas treatment device 40 is provided in the flue 38. The exhaust gas treatment device 40 reduces or removes harmful substances contained in the exhaust gas flowing through the flue 38, such as nitrogen oxide, sulfur oxide, PM (Particulate Matter), and the like. The exhaust gas treatment device 40 may be a separate device for each harmful substance to be treated, or may be a single device capable of treating a plurality of harmful substances.

  The dissolving device 20 is a device that dissolves carbon dioxide contained in exhaust gas in seawater. The dissolution apparatus 20 includes a dissolution module 50, a supply pipe 52, a discharge pipe 54, a first pH (hydrogen ion concentration) meter 56, a second pH meter 58, a first flow rate adjustment valve 60, and a second flow rate adjustment valve. 62, flow meters 66 and 67, and a control unit 70.

  The melting module 50 is disposed between the exhaust gas treatment device 40 and the chimney 42 in the flue 38. As shown in FIG. 3, the melting module 50 includes an absorption tower 90 and a spray unit 92. The absorption tower 90 is connected to the flue 38 and further to the discharge pipe 54. The absorption tower 90 has a shape extending in the vertical direction. The absorption tower 90 has a flue 38 on the upstream side in the exhaust gas flow direction connected to a vertically lower surface, that is, in the vicinity of the bottom surface. Further, the absorption tower 90 has a flue 38 on the downstream side in the exhaust gas flow direction connected to the vertical upper surface, that is, the top surface. Thereby, the exhaust gas supplied to the absorption tower 90 flows in from the vicinity of the bottom surface and is discharged from the top surface. That is, the exhaust gas flows from the lower side in the vertical direction of the absorption tower 90 to the upper side. The absorption tower 90 has a discharge pipe 54 connected to the bottom surface. The spray unit 92 is inserted in the vicinity of the upper end of the absorption tower 90 in the vertical direction, and is connected to the supply pipe 52. The spray unit 92 is provided with at least one head for spraying seawater with fine droplets, for example, atomized. The head has a plurality of holes through which, for example, seawater is jetted. The operation of the melting module 50 will be described later.

  The supply pipe 52 has one end connected to the downstream side of the pump 14 of the water intake pipe 13 and the other end connected to the melting module 50. A part of the seawater flowing through the intake pipe 13 flows into the supply pipe 52, and the supplied seawater is supplied to the melting module 50. One end of the discharge pipe 54 is connected to the melting module 50, and the other end is connected to a position downstream of the connection position of the intake pipe 13 with the supply pipe 52 in the seawater flow direction. The discharge pipe 54 discharges the seawater that has passed through the melting module 50 to the water pipe 13. In the melting module 50 of this embodiment, the supply pipe 52 is connected to the upstream portion of the absorption tower 90 in the exhaust gas flow direction, and the exhaust pipe 54 is connected to the downstream portion of the absorption tower 90 in the exhaust gas flow direction. ing.

  The first pH (hydrogen ion concentration) meter 56 is disposed in the discharge pipe 54 and measures the pH value of the seawater that has passed through the dissolution module 50. The 2nd pH meter 58 is arrange | positioned at the intake pipe 13, and the pH value of the seawater which flows through the intake pipe 13, specifically, the pH value of the seawater which flows downstream from the position where the discharge pipe 54 is connected is shown. taking measurement. That is, the second pH meter 58 measures the pH value of the seawater after the seawater flowing through the discharge pipe 54 joins the seawater flowing through the intake pipe 13. The first flow rate adjustment valve 60 is disposed at a portion between the intake pipe 13, specifically, a connection portion of the intake pipe 13 with the supply pipe 52 and a connection portion of the discharge pipe 54. Adjust the flow rate of the seawater flowing through 13. The second flow rate adjustment valve 62 is disposed in the discharge pipe 54 and adjusts the flow rate of seawater flowing through the discharge pipe 54. The flow meter 66 is disposed on the upstream side of the intake pipe 13, specifically, the connection portion of the intake pipe 13 with the supply pipe 52, and measures the flow rate of seawater flowing through the intake pipe 13. The flow meter 67 measures the flow rate of the exhaust gas flowing between the flue 38, specifically, between the exhaust gas treatment device 40 and the melting module 50. The first pH (hydrogen ion concentration) meter 56, the second pH meter 58, and the flow meters 66 and 67 send the measurement results to the control unit 70. Based on the measurement results of the first pH meter 56, the second pH meter 58, and the flow meters 66, 67, the control unit 70 adjusts the opening and opening / closing of the first flow rate adjustment valve 60 and the second flow rate adjustment valve 62, and dissolves them. The flow rate of the seawater supplied to the module 50 is adjusted.

  In the melting device 20, the seawater that flows into the supply pipe 52 from the intake pipe 13 is supplied to the melting module 50. Seawater supplied from the supply pipe 52 to the melting module 50 is sprayed from the spraying part 92 into the absorption tower 90. In the melting apparatus 20, the exhaust gas passing through the flue 38 passes through the absorption tower 90 as a flow from the lower side in the vertical direction to the upper side in the vertical direction. When the exhaust gas passes through the absorption tower 90, the dissolving device 20 comes into contact with seawater droplets sprayed in the absorption tower 90, and a part of carbon dioxide contained in the exhaust gas is dissolved on the seawater side. The liquid sprayed on the absorption tower 90 falls while coming into contact with the exhaust gas, and arrives at the bottom surface in the vertical direction. Seawater that has arrived at the bottom surface of the absorption tower 90 is in a state in which carbon dioxide in the exhaust gas is dissolved. Seawater that has arrived at the bottom surface of the absorption tower 90 is discharged from the discharge pipe 54. In this way, the melting device 20 discharges the seawater in which carbon dioxide has been dissolved through the melting module 50 to the discharge pipe 54 and discharges the seawater from the discharge pipe 54 to the intake pipe 13. The dissolution apparatus 20 sprays seawater on the absorption tower 90 as described above, and makes the carbon dioxide in the exhaust gas dissolve in seawater by bringing the seawater droplets into contact with the exhaust gas, thereby lowering the pH value of the seawater. .

  Further, the dissolving device 20 is controlled by the controller 70 based on the measurement results of the first pH meter 56, the second pH meter 58, and the flow meters 66, 67, and the opening amounts of the first flow rate adjustment valve 60 and the second flow rate adjustment valve 62, The amount of carbon dioxide dissolved in the seawater is adjusted by adjusting the opening and closing and adjusting the flow rate of the seawater supplied to the dissolution module 50. Specifically, the dissolving device 20 sets the pH value of seawater that has passed through the dissolving device 20, that is, seawater flowing through the intake pipe 13 on the downstream side of the connection portion with the discharge pipe 54 to 6 or less, specifically pH. Adjust the flow rate of seawater so that the value is 5 or more and 6 or less. The dissolving device 20 dissolves carbon dioxide in a part of the seawater flowing through the intake pipe 13 and merges the seawater with the seawater flowing through the intake pipe 13 to obtain a target pH value. The pH value of seawater discharged from 50 and the pH value of seawater flowing through the discharge pipe 54 are lower than the target pH value.

  The air diffuser 22 is disposed in the vicinity of the outlet of the water discharge pipe 17, and blows air into the seawater flowing through the water discharge pipe 17, thereby releasing carbon dioxide dissolved in the seawater to the atmosphere and increasing the pH value of the seawater. . The air diffuser 22 includes a blower 80, a flow rate adjustment valve 81, an air diffuser 82, a pH meter 83, and a regulator 84.

  The blower 80 is a blower that sends air, and is connected to the air diffuser 82 by piping. The blower 80 sends air to the air diffuser 82. The flow rate adjusting valve 81 is disposed in a pipe between the blower 80 and the air diffuser 82 and adjusts the flow rate of air sent from the blower 80 to the air diffuser 82. The air diffuser 82 is disposed inside the water discharge pipe 17, and a hole for releasing air is formed inside the water discharge pipe 17. The air diffuser 82 discharges the air that has passed through the flow rate adjustment valve 81 from the hole to the water discharge pipe 17, thereby turning the air into fine bubbles and blowing it into the seawater of the water discharge pipe 17. The pH meter 83 measures the pH value of the seawater flowing through the water discharge pipe 17, specifically, the pH value of the seawater flowing upstream from the position where the air diffuser 82 is disposed. The adjuster 84 adjusts the opening of the flow rate adjustment valve 81 based on the measurement result of the pH meter 83 and adjusts the amount of air blown into the seawater from the air diffuser 82.

  The air diffuser 22 is configured as described above. The pH meter 83 detects the pH value of the seawater that leaves the heat exchanger 4 and flows through the water discharge pipe 17, and based on the result, the regulator 84 controls the flow rate adjustment valve 81. The amount of air blown into the seawater from the air diffuser 82 is adjusted. When the pH value of the seawater is outside the discharge regulation range (for example, the pH value is 5.8 or more and 8.6 or less), the air diffuser 22 sends a signal from the regulator 84 to which the signal of the pH meter 83 is input. Then, the flow regulating valve 81 is opened, air is sent from the blower 80 to the air diffuser 82, and air is discharged from the air diffuser 82 to the seawater in the water discharge pipe 17. The air diffuser 22 releases the carbon dioxide gas dissolved in the seawater to the atmosphere by releasing the air into the seawater in the form of fine bubbles. Thereby, the air diffuser 22 increases the pH value of the seawater flowing through the water discharge pipe 17 so that the pH value of the discharged seawater falls within the range of the discharge regulation value (pH value is 5.8 or more and 8.6 or less). Adjust to.

  The power generation system 1 injects carbon dioxide into the seawater taken into the water intake pipe 13 by the melting device 20 so that the pH value is, for example, 6 or less, so that the pH in the heat exchanger 4 and the seawater circulation device 6 is increased. The seawater which the value fell can be poured. Thereby, the electric power generation system 1 can suppress that marine organisms, such as an adhering organism with a shell, adhere to the path through which seawater flows and grow. In addition, since the power generation system 1 dissolves carbon dioxide so that the seawater flowing in the pipeline is in the proper pH range, the sea life having shells adheres to these tubes and the heat exchanger 4 and the shells are removed. Generation | occurrence | production can be prevented reliably and it can suppress killing useful plankton etc. indiscriminately. Thereby, the electric power generation system 1 can reduce the influence which it has on the sea, suppressing adhesion of marine organisms. In addition, by releasing seawater rich in carbon dioxide, it becomes possible to increase the plankton in the seawater and make it easier for fish and the like to live. Furthermore, since it is not necessary to prepare a cylinder gas filled with 100% carbon dioxide, the running cost can be reduced.

  The power generation system 1 can effectively utilize the carbon dioxide in the combustion exhaust gas generated in the power generation system 1 by dissolving carbon dioxide contained in the exhaust gas generated from the boiler 32 of the power generation unit 30 in seawater. Thereby, the air pollution which arises in the electric power generation system 1 can be decreased. In addition, the power generation system 1 can suppress the occurrence of corrosion of equipment and piping compared to the case where a chlorine-based disinfectant is used, and the processing when discharging to the sea is simplified.

  The melting device 20 sprays seawater into the absorption tower 90 by the spraying unit 92, thereby bringing seawater and exhaust gas into contact with each other and dissolving carbon dioxide in the seawater. Here, the melting device 20 can reduce the pressure loss generated in the exhaust gas by dispersing the sea water into fine droplets in the spray unit 92 and bringing the sea water into contact with the exhaust gas. In addition, the dissolving device 20 can increase the surface area of the seawater and increase the dissolution rate of carbon dioxide by dispersing the seawater into fine droplets by the spray unit 92. Thus, the melting device 20 can move carbon dioxide from the exhaust gas flowing in the atmospheric pressure atmosphere to the seawater by spraying the seawater into the absorption tower 90 by the spraying unit 92. Thereby, even if it does not use mechanisms, such as a blower which sends exhaust gas and carbon dioxide, carbon dioxide can be dissolved in seawater with the power of the flow at the time of being discharged from boiler 32. Thereby, the apparatus configuration can be simplified and the apparatus cost can be reduced.

  Further, the dissolving device 20 can flow seawater using the force of the pump 14 of the seawater circulation device 6. Thereby, since it is not necessary to newly add the driving force for flowing seawater, an apparatus structure can be simplified and apparatus cost can also be reduced.

  In addition, the dissolving device 20 is provided with a flow path serving as a bypass of the intake pipe 13 by the supply pipe 52 and the discharge pipe 54 so that a part of the seawater flowing through the intake pipe 13 is supplied to the dissolution module 50. It can suppress that a piping system becomes large. Moreover, since seawater of a required flow rate can be supplied to the melting module 50, it is possible to suppress a large load from being applied to the melting module 50. Moreover, the enlargement of the melting module 50 can be suppressed.

  In addition, by providing the melting module 50 in the flue 38, the melting device 20 can cause all exhaust gas discharged to pass through the absorption tower 90, and can easily dissolve carbon dioxide. Further, the melting apparatus 20 can be installed without newly adding a pipe for flowing exhaust gas, and the apparatus configuration can be simplified.

  In addition, the dissolution apparatus 20 includes a first flow rate adjustment valve 60 and a second flow rate adjustment valve 62, and adjusts the flow rate of seawater supplied to the dissolution module 50 by the control unit 70 based on the measurement result. The pH value can be adjusted to a more suitable range. It is also possible to adjust according to the flow rate of exhaust gas and the flow rate of seawater. In the present embodiment, the first flow rate adjustment valve 60 and the second flow rate adjustment valve 62 are provided, but the flow rate can be similarly adjusted using only one of the flow rate adjustment valves.

  In addition, the power generation system 1 uses the exhaust gas supplied to the melting device 20 as the exhaust gas that has passed through the exhaust gas processing device 40, thereby suppressing the dissolution of impurities, for example, harmful substances, into seawater when passing through the absorption tower 90. Can do. Thereby, it can suppress that the electric power generation system 1 exerts a bad influence on the sea.

  In addition, the power generation system 1 can increase the pH value by blowing air into the seawater before being released and dissipating carbon dioxide gas dissolved in the seawater to the atmosphere by the air diffuser 22. Thereby, the electric power generation system 1 can perform feedback control so that the pH value of the seawater discharged into the sea falls within the range of the discharge regulation value, and can discharge the seawater in an appropriate state.

  Moreover, although the melt | dissolution apparatus 20 of a present Example sprayed seawater toward the vertical direction lower side by the spraying part 92, you may spray on the vertical direction upper side. The melting device 20 sprays seawater upward in the vertical direction, so that the time floating in the absorption tower 90 can be made longer, and more carbon dioxide can be dissolved. Moreover, it is preferable that the spraying part 92 arrange | positions the head which sprays seawater in a horizontal direction like this embodiment. Thereby, seawater can be sprayed to the whole area in the absorption tower 90, and more carbon dioxide can be dissolved. Moreover, it is also preferable that the spraying part 92 arranges a plurality of heads for spraying seawater in the vertical direction. Thereby, seawater can be sprayed to the whole area in the absorption tower 90, and more carbon dioxide can be dissolved. In the present embodiment, the absorption tower 90 has a shape extending in the vertical direction, but may be inclined with respect to the vertical direction. Moreover, it is preferable that the absorption tower 90 has a shape in which a bottom surface is inclined so that seawater flows toward the discharge pipe 54, and a connection portion with the discharge pipe 54 is the lowest in the vertical direction. Further, the position at which the absorption tower 90 and the flue 38 are connected is not limited to the present embodiment. However, as in this embodiment, the exhaust gas flows from the lower side in the vertical direction to the upper side, thereby absorbing the droplet of seawater. The floating time in 90 can be lengthened, and more carbon dioxide can be dissolved.

  Since the melting device 20 of the present embodiment can efficiently dissolve carbon dioxide in seawater, the seawater flowing through the seawater circulation device 6 is sprayed on the absorption tower 90 through which the entire amount of exhaust gas flowing through the area of the atmospheric atmosphere of the flue flows. Although the carbon dioxide in the exhaust gas is dissolved in the seawater sprayed in the absorption tower 90, it is not limited to this. The melting device 20 may flow at least a part of the exhaust gas flowing in the region of the atmospheric atmosphere of the flue to the absorption tower 90 and spray at least a part of the seawater flowing in the seawater circulation device 6 by the spraying unit.

  FIG. 4 is a schematic diagram illustrating a schematic configuration of the power generation system according to the second embodiment of the present invention. In addition, the same code | symbol is attached | subjected to the member which has the function similar to the Example mentioned above, and detailed description is abbreviate | omitted.

  The power generation system 101 according to the second embodiment includes a main pipe 138 in which the flue 38 does not pass through the melting module 50 and a branch pipe 139 through which the melting module 50 passes. In the flue 38, the branch pipe 139 bypasses the main pipe 138. A dissolution module 50 is disposed in the branch pipe 139. The exhaust gas that has flowed into the branch pipe 139 passes through the melting module 50, and then merges with the exhaust gas flowing through the main pipe 138, and is discharged from the chimney 42 to the outside.

  The melting apparatus 120 includes flow rate adjustment valves 192 and 194 that adjust the flow rate of exhaust gas. The flow rate adjustment valve 192 is disposed in the main pipe 138 and adjusts the flow rate of the exhaust gas flowing through the main pipe 138. The flow rate adjusting valve 194 is disposed in the branch pipe 139 and adjusts the flow rate of the exhaust gas flowing through the branch pipe 139.

  The power generation system 101 supplies part of the exhaust gas to the melting module 50 and dissolves carbon dioxide in the exhaust gas in seawater. The power generation system 101 may supply only a part of the exhaust gas to the melting module 50 of the melting apparatus 120 as in the present embodiment. The power generation system 101 can adjust the flow rate of the exhaust gas supplied to the melting module 50 by providing the flow rate adjustment valves 192 and 194 and adjusting the opening degree and opening / closing. In the present embodiment, the flow rate adjusting valves 192 and 194 are provided, but the flow rate of the exhaust gas can be similarly adjusted with only one of the flow rate adjusting valves.

  In the power generation systems 1 and 101 of the present embodiment, fuel is burned in a boiler, and heat generation is performed by rotating the steam turbine 34 with a heat medium heated by exchanging heat with the generated combustion gas. It is not limited to this. The power generation unit may burn the fuel in the combustor of the gas turbine. The power generation unit may be a combined cycle in which a plurality of facilities for generating power such as a gas turbine and a steam turbine, a gas turbine and a fuel cell, or a gas turbine, a steam turbine, and a fuel cell are combined. Further, although the power generation systems 1 and 101 are provided with the air diffuser 22, the air diffuser 22 may not be provided.

  Next, an example of the relationship between the amount of seawater circulated in the seawater circulation device 6 of the power generation system, the exhaust gas flowing through the flue 38, and the amount of seawater and flue gas passing through the melting module 50 will be described.

As fuel, C is 79.6%, H is 1.5%, O is 1.3%, S is 0.4%, N is 0.4%, ash is 13.3%, and moisture is 3. 5%, theoretical air volume 7.5 m ³ _N / kg, theoretical fuel gas volume 7.6 m ³ _N / kg, CO ₂ maximum value 20.2%, high heat value 28970 kJ / kg, low heat value When using anthracite (coal) with an amount of 28510 kJ / kg, the higher calorific value is 891000 kJ / mol, the lower calorific value is 800 900 kJ / mol, the higher calorific value is 55560 kJ / kg, and the lower calorific value is 50030 kJ / kg. An explanation will be given of the case where LNG mainly composed of methane having kg, a high calorific value of 39730 kJ / m ³ _N and a low calorific value of 35840 kJ / m ³ _N is used.

When the fuel of the power generation system 1 is burned, the condenser loss (heat exchanger loss, cooling loss) is 46%, the generator output is 40%, and the exhaust gas is 14%. The pH value of seawater for preventing the adhesion of shellfish is set to 6, and the carbon dioxide (CO ₂ ) concentration in the corresponding seawater is set to 50 mg / L (= 50 g / t). Next, the specific heat of the seawater is 1 kcal / (kg ° C.) = 4.19 kJ / (kg ° C.). The temperature difference between the seawater inlet and outlet of the heat exchanger 4 is set to 5 ° C.

When the output of the power generation system 1 is 1 million kW, the energy is
860 kJ / kWh × 1 million kW = 8.6 × 10 ¹¹ J / h = 860 GJ.

  Next, the amount of seawater required for cooling is calculated. From the energy balance described above, generator output: heat exchanger loss = 40%: 46% = 860 GJ / h: condenser heat loss. Therefore, the heat quantity of the condenser is 860 GJ / h × (46% / 40%) = 989 GJ / h. The seawater flow rate for heat exchange of 989 GJ is 989 [GJ / h] /4.19 [kJ / (kg ° C.)] / 5 [° C.] / 1000 [kg / t] in consideration of the specific heat and the temperature difference between the inlet and outlet. ] = 47000 [t / h]. That is, the seawater flow rate required for the power generation system with an output of 1 million kW is 47000 t / h.

Next, the amount of carbon dioxide generated is calculated. From the energy balance described above, generator output: fuel = 40%: 100% = 860 GJ / h: fuel heat quantity. Therefore, the fuel heat quantity is 860 GJ / h × 100% / 40% = 2150 GJ / h. Here, when the fuel is coal, the lower heating value of coal is 28510 kJ / kg, so the amount of fuel used is 2150 [GJ / h] / 28510 [kJ / kg] / 1000 [kg / t] = 75. [T / h]. Here, since C + O ₂ → CO ₂ , 44 carbon dioxide (CO ₂ ) is generated with respect to C 12 in consideration of the molecular weight. Here, since the carbon content of the coal of this example is 79.6%, the amount of CO ₂ generated is 75 t / h × 0.796 × (44/12) = 220 t / h. Here, the air of oxygen 20%, as 80% nitrogen, When the complete combustion, since nitrogen is 4 times the CO ₂ CO ₂ concentration is 20%.

On the other hand, when the fuel is LNG, the lower heating value of LNG is 47520 kJ / kg, so the amount of fuel used is 2150 [GJ / h] / 47520 [kJ / kg] / 1000 [kg / t]. = 45 [t / h]. Here, since CH ₄ + 2O ₂ → CO ₂ + 2H ₂ O, when considering the molecular weight, 44 carbon dioxide (CO ₂ ) is generated for 16 CH ₄ . The amount of CO ₂ generated is 45 t / h × (44/16) = 124 t / h. Here, the air of oxygen 20%, as 80% nitrogen, When the complete combustion, nitrogen is four times the CO _2, CO ₂ concentration because steam is 2 times the CO ₂ is 14%.

Next, the flow rate balance is calculated. As described above, the carbon dioxide concentration to be dissolved in seawater, pH value because 6 equivalent 50 g / t, the amount of CO ₂ dissolved in sea water Multiplying seawater flow rate (dissolution amount of CO ₂₎ can be calculated. Specifically, it is 2.4 t / h in the case of coal, and 1.3 t / h in the case of LNG.

Here, dissolving module 50 may dissolve CO ₂ until substantially saturated with the exhaust gas in the CO ₂ concentration. Here, the hollow fiber membrane, since it is possible to dissolve in seawater CO ₂ without generating bubbles, CO ₂ can be regarded as the case of 100%. The saturated dissolved CO ₂ concentration is 1.49 g / L (1490 g / t). The CO ₂ concentration at the outlet of the melting module 50 (melting facility outlet CO ₂ concentration) can be calculated by multiplying 1490 g / t by the CO ₂ concentration in the exhaust gas. Therefore, it is 298 g / t for coal and 209 g / t for LNG.

From the above, the supply flow rate of seawater to the dissolution module (dissolution facility seawater flow rate) required for dissolving CO ₂ having a predetermined concentration in the seawater flowing through the intake pipe is 0.00789 t / h in the case of coal. In this case, it becomes 0.01127 t / h.

  Next, the case where the combined unit of the gas steam turbine and the steam turbine is the power generation unit 30 will be considered. That is, the case where the power generation system 1 is a gas steam turbine combined power plant will be examined. In this example, the energy balance when the fuel of the gas steam turbine combined power plant is burned is as follows: condenser loss (heat exchanger loss, cooling loss) is 31%, generator output is 49%, and exhaust gas is 18%. %. In this example, the case where LNG was used as a fuel was examined.

  Calculate the amount of seawater required to cool the gas steam turbine combined power plant. From the energy balance described above, generator output: heat exchanger loss = 31%: 39% = 860 GJ / h: condenser heat loss. Therefore, the condenser heat quantity is 860 GJ / h × (41% / 49%) = 544 GJ / h. The seawater flow rate for heat exchange of 544GJ is 544 [GJ / h] /4.19 [kJ / (kg ° C)] / 5 [° C] / 1000 [kg / t, taking into account the specific heat and the temperature difference between the inlet and outlet. ] = 26000 [t / h]. That is, the seawater flow rate required for the power generation system with an output of 1 million kW is 26000 t / h. Further, the carbon dioxide generation amount is 120 [t / h] × 49 [%] / 40 [%] = 98 [t / h].

As described above, the supply flow rate of seawater to the dissolution module (dissolution facility seawater flow rate) necessary for dissolving CO ₂ having a predetermined concentration in the seawater flowing through the intake pipe is 0.0623 t / h.

  As shown in Table 1, the power generation system according to the present embodiment has a necessary amount of carbon dioxide for seawater by supplying a part of the seawater flowing through the intake pipe to the melting module 50 in any power generation method. Can be dissolved.

DESCRIPTION OF SYMBOLS 1,101 Power generation system 2 Steam turbine building 4 Heat exchanger 6 Seawater circulation device 8 Intake channel 13 Intake pipe 14 Pump 17 Drain pipe 20 Dissolution device 22 Aeration device 30 Power generation unit 32 Boiler 34 Steam turbine 36 Heat medium circulation line 38 Smoke Road 40 Exhaust gas treatment device 42 Chimney 50 Melting module 52 Supply pipe 54 Discharge pipe 56 First pH meter 58 Second pH meter 60 First flow rate adjustment valve 62 Second flow rate adjustment valve 66, 67 Flow meter 70 Control unit 80 Blower 81 Flow rate adjustment valve 82 Aeration unit 83 pH meter 84 Controller 90 Absorption tower 92 Spray unit

Claims (6)

A power generation unit for generating electricity by burning fuel containing carbon;
A flue through which the exhaust gas generated in the power generation unit flows,
A seawater circulation device that has a pump, feeds seawater with the pump, and circulates seawater between the power generation unit and the sea;
A dissolving device for dissolving carbon dioxide in seawater flowing downstream from the pump of the seawater circulation device,
The melting device includes an absorption tower in which at least a part of the exhaust gas flowing in an area of an atmospheric pressure atmosphere of the flue flows, and at least a part of the seawater that is inserted into the absorption tower and flows in the seawater circulation device. And a spray module for spraying the carbon dioxide in the exhaust gas into the seawater sprayed in the absorption tower. The dissolution apparatus connects the seawater circulation device and the dissolution module, and supplies a part of seawater flowing through the seawater circulation device to the dissolution module;
Connecting the portion of the seawater circulation device downstream of the supply pipe in the flow direction of seawater and the dissolution module, and discharging the seawater that has passed through the dissolution module to the seawater circulation device;
The power generation system according to claim 1, wherein after dissolving carbon dioxide in a part of seawater flowing through the seawater circulation device, the seawater in which carbon dioxide is dissolved is discharged to the seawater circulation device.   The power generation system according to claim 2, wherein the melting module is installed in the flue. A first flow rate adjusting valve disposed between the supply pipe and the discharge pipe of the seawater circulation device;
A second flow rate adjustment valve disposed in the supply pipe,
The control part which adjusts the opening degree of the said 1st flow control valve and the said 2nd flow control valve, and adjusts the flow volume of the said seawater supplied to the said melt | dissolution apparatus is further provided. Power generation system. Further comprising an exhaust gas treatment device disposed in the flue to reduce impurities contained in the exhaust gas;
The power generation system according to any one of claims 1 to 4, wherein the dissolving device dissolves carbon dioxide in the exhaust gas that has passed through the exhaust gas treatment device into the seawater. The power generation unit has a steam turbine,
A heat exchanger that cools the heat medium that has passed through the steam turbine with the seawater;
The seawater circulation device includes a water intake pipe that supplies the seawater to the heat exchanger, and a water discharge pipe that discharges the seawater that has passed through the heat exchanger,
The power generation system according to any one of claims 1 to 5, wherein the melting device dissolves carbon dioxide in the exhaust gas into the seawater flowing through the intake pipe.

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