Water recovery system, method for operating a water recovery system, and method for modifying a water recovery system

Abstract

To provide a water recovery system capable of improving power generation efficiency of a gas turbine cogeneration system, an operating method for the water recovery system and a modification method for the water recovery system.SOLUTION: A water recovery system has a first binary power generation system including: a first evaporator for evaporating a first circulation low-boiling point working medium that is a first organic medium; a first turbine configured to obtain rotating power from the evaporated first circulation low-boiling point working medium; and a first power generator coupled to the first turbine. The first evaporator is configured to evaporate the first circulation low-boiling point working medium by using at least part of exhaust gas flowing from an exhaust heat recovery boiler toward a water recovery device as a heat source.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present disclosure relates to a water recovery system for recovering moisture from exhaust gas of a heat recovery boiler that constitutes a gas turbine cogeneration system, a method for operating the water recovery system, and a method for modifying the water recovery system. [Background technology]

[0002] Conventionally, water recovery systems for recovering moisture from exhaust gas of a heat recovery boiler that constitutes a gas turbine cogeneration system have been known. For example, the water recovery system disclosed in Patent Document 1 includes a water recovery device configured to recover moisture by heat exchange between the exhaust gas of the heat recovery boiler and circulating water. The circulating water containing the recovered moisture is circulated between the water recovery device and a circulating water cooler by the power of a circulating water pump. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent Publication No. 2021-060012 Summary of the Invention [Problem to be solved by the invention]

[0004] In the above configuration, only a portion of the heat contained in the exhaust gas from the heat recovery boiler is recovered by the recovered water, and it cannot be said that this heat is being effectively utilized. Therefore, further improvement in the power generation efficiency of gas turbine cogeneration systems is desired.

[0005] An object of the present disclosure is to provide a water recovery system, a method for operating a water recovery system, and a method for modifying a water recovery system that improve the power generation efficiency of a gas turbine cogeneration system. [Means for solving the problem]

[0006] In accordance with at least one embodiment of the present disclosure, a water recovery system includes: a water recovery device for recovering moisture from exhaust gas discharged from a heat recovery boiler of a gas turbine cogeneration system by heat exchange between the exhaust gas and refrigerant water; a recovered water cooling system including a recovered water cooler for cooling the recovered water containing moisture recovered by the water recovery device; a recovered water circulation line for guiding the recovered water discharged from the water recovery device to the recovered water cooler and for guiding the recovered water cooled by the recovered water cooler to the water recovery device as the refrigerant water; a recovered water circulation pump disposed in the recovered water circulation line; A water recovery system comprising: a first binary power generation system including a first evaporator for evaporating a first circulating low boiling point working medium, which is a first organic medium; a first turbine configured to obtain rotational power from the evaporated first circulating low boiling point working medium; and a first generator connected to the first turbine; The first evaporator is configured to evaporate the first circulating low-boiling-point working medium using, as a heat source, at least a portion of the exhaust gas flowing from the heat recovery boiler toward the water recovery device.

[0007] Here, a binary power generation system is a power generation system that applies unused low-temperature waste heat, which may be heat contained in the exhaust gas of a turbine, as a direct or indirect heat source to an organic medium Rankine cycle. That is, in a binary power generation system, at least a portion of the unused low-temperature waste heat is used as a heat source for an evaporator that constitutes a Rankine cycle, and organic medium vapor generated in the evaporator drives a turbine to generate electricity.

[0008] According to one embodiment of the present disclosure, a method for operating a water recovery system includes: a water recovery device for recovering moisture from exhaust gas discharged from a heat recovery boiler of a gas turbine cogeneration system by heat exchange between the exhaust gas and refrigerant water; a recovered water cooling system including a recovered water cooler for cooling the recovered water containing moisture recovered by the water recovery device; a recovered water circulation line for guiding the recovered water discharged from the water recovery device to the recovered water cooler and for guiding the recovered water cooled by the recovered water cooler to the water recovery device as the refrigerant water; a recovered water circulation pump disposed in the recovered water circulation line; A method of operating a water recovery system comprising: The water recovery system comprises: a first binary power generation system including a first evaporator for evaporating a first circulating low boiling point working medium that is a first organic medium, a first turbine configured to obtain rotational power from the evaporated first circulating low boiling point working medium, and a first generator connected to the first turbine; a first exhaust gas line for guiding the exhaust gas discharged from the heat recovery boiler to the first evaporator; a second exhaust gas line for guiding the exhaust gas discharged from the first evaporator to the water recovery device; a bypass exhaust gas line connected to the first exhaust gas line and the second exhaust gas line so as to bypass the first evaporator; a combined exhaust gas line connecting a connection point between the second exhaust gas line and the bypass exhaust gas line and the water recovery device; an exhaust gas damper for changing a ratio of a flow rate of the exhaust gas flowing into the first evaporator to a flow rate of the exhaust gas flowing through the bypass exhaust gas line; a water recovery device exhaust gas inlet temperature sensor for measuring the temperature of the exhaust gas flowing downstream of a position in the combined exhaust gas line where the second exhaust gas line is connected to the bypass exhaust gas line, The method for operating the water recovery system includes: The method further includes an exhaust gas damper control step of controlling the exhaust gas damper so that the temperature measured by the water recovery device exhaust gas inlet temperature sensor becomes a first specified temperature.

[0009] According to one embodiment of the present disclosure, a method for retrofitting a water recovery system includes: a water recovery device for recovering moisture from exhaust gas discharged from a heat recovery boiler of a gas turbine cogeneration system by heat exchange between the exhaust gas and refrigerant water; a recovered water cooling system including a recovered water cooler for cooling the recovered water containing moisture recovered by the water recovery device; a recovered water circulation line for guiding the recovered water discharged from the water recovery device to the recovered water cooler and for guiding the recovered water cooled by the recovered water cooler to the water recovery device as the refrigerant water; a recovered water circulation pump disposed in the recovered water circulation line; A method for retrofitting a water recovery system comprising: a first binary power generation system additional installation step of additionally installing a first binary power generation system including a first evaporator for evaporating a first circulating low boiling point working medium which is a first organic medium, a first turbine configured to obtain rotational power from the evaporated first circulating low boiling point working medium, and a first generator connected to the first turbine; an exhaust gas line adding step of adding a first exhaust gas line for guiding the exhaust gas discharged from the exhaust heat recovery boiler to the first evaporator, and a second exhaust gas line for guiding the exhaust gas discharged from the first evaporator to the water recovery device; Equipped with.

[0010] According to one embodiment of the present disclosure, a method for retrofitting a water recovery system includes: a water recovery device for recovering moisture from exhaust gas discharged from a heat recovery boiler of a gas turbine cogeneration system by heat exchange between the exhaust gas and refrigerant water; a recovered water cooling system including a recovered water cooler for cooling the recovered water containing moisture recovered by the water recovery device; a recovered water circulation line for guiding the recovered water discharged from the water recovery device to the recovered water cooler and for guiding the recovered water cooled by the recovered water cooler to the water recovery device as the refrigerant water; a recovered water circulation pump disposed in the recovered water circulation line; a first binary power generation system including a first evaporator for evaporating a first circulating low boiling point working medium which is a first organic medium, a first turbine configured to obtain rotational power from the evaporated first circulating low boiling point working medium, and a first generator connected to the first turbine; A method for modifying a water recovery system, wherein the first evaporator is configured to evaporate the first circulating low-boiling point working medium using at least a portion of the exhaust gas flowing from the heat recovery boiler toward the water recovery device as a heat source, a second binary power generation system installation step of installing a second binary power generation system including a second evaporator for evaporating a second circulating low boiling point working medium which is a second organic medium, a second turbine configured to obtain rotational power from the evaporated second circulating low boiling point working medium, and a second generator connected to the second turbine, wherein the second evaporator is configured to evaporate the second circulating low boiling point working medium using at least a portion of the recovered water flowing through the recovered water circulation line as a heat source; a power generation recovered water line adding step of adding a power generation recovered water supply line for guiding the recovered water discharged from the water recovery device to the second evaporator, and a power generation recovered water discharge line for guiding the recovered water discharged from the second evaporator to the water recovery device; Equipped with. [Effects of the Invention]

[0011] According to the present disclosure, it is possible to provide a water recovery system that improves the power generation efficiency of a gas turbine cogeneration system, a method for operating a water recovery system, and a method for modifying a water recovery system. [Brief explanation of the drawings]

[0012] [Figure 1] 1 is a schematic diagram of a gas turbine cogeneration system according to an embodiment. [Figure 2] 1 is a schematic diagram of a water recovery system according to one embodiment. [Figure 3] FIG. 2 is a schematic diagram of a first binary power generation system according to an embodiment. [Figure 4A] 1 is a schematic diagram of a water recovery system according to a first embodiment. [Figure 4B] FIG. 10 is a schematic diagram of a water recovery system according to a second embodiment. [Figure 4C] FIG. 10 is a schematic diagram of a water recovery system according to a third embodiment. [Figure 5] 1 is a graph showing the relationship between the flow rate of exhaust gas and the amount of recovered power of the water recovery system according to one embodiment. [Figure 6] 1 is a graph showing the relationship between the flow rate of exhaust gas and the cooling heat load of the water recovery system according to one embodiment. [Figure 7] 4 is a flowchart showing a water recovery system operation process according to one embodiment. [Figure 8] 1 is a flowchart illustrating a method for retrofitting a water recovery system according to one embodiment. [Figure 9] FIG. 1 is a schematic diagram of a water recovery system before modification according to one embodiment. [Figure 10] 1 is a flowchart illustrating a method for retrofitting a water recovery system according to one embodiment. [Figure 11] FIG. 2 is a schematic diagram of another pre-modification water recovery system according to an embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0013] Hereinafter, several embodiments of the present disclosure will be described with reference to the accompanying drawings. However, the dimensions, materials, shapes, relative arrangements, etc. of components described as embodiments or shown in the drawings are merely illustrative examples and are not intended to limit the scope of the present disclosure. For example, expressions expressing relative or absolute arrangement such as "in a certain direction," "along a certain direction," "parallel," "orthogonal," "center," "concentric," or "coaxial" not only express such an arrangement exactly, but also express a state in which there is a relative displacement with a tolerance or an angle or distance to the extent that the same function is obtained. For example, expressions such as "identical," "equal," and "homogeneous" that indicate that something is in an equal state not only indicate a state of strict equality, but also indicate a state in which there is a tolerance or a difference to the extent that the same function is obtained. For example, expressions representing shapes such as a square shape or a cylindrical shape not only represent shapes such as a square shape or a cylindrical shape in the strict geometric sense, but also represent shapes including uneven portions, chamfered portions, etc., to the extent that the same effect can be obtained. On the other hand, the expressions "comprise," "include," or "have" one element are not exclusive expressions that exclude the presence of other elements. Note that the same components will be denoted by the same reference numerals and the description thereof will be omitted.

[0014] <1. Overview of Gas Turbine Cogeneration System 10> 1 is a schematic diagram of a gas turbine cogeneration system 10 according to an embodiment of the present disclosure. In the following description, the "gas turbine cogeneration system 10" may be abbreviated simply as the "cogeneration system 10."

[0015] The cogeneration system 10 includes a gas turbine 9 and a fuel supply system 4. The gas turbine 9 includes a compressor 16 for generating compressed air 7 from compressor inlet air 6, a combustor 3 for burning fuel supplied by the fuel supply system 4 and raising the temperature of the compressed air 7 to generate combustion gas 12, a turbine 2 for rotating using the combustion gas 12 discharged from the combustor 3 as a driving source, and a generator 5 connected to the turbine 2. The combustor 3 is, for example, a diffusion-type combustor. The generator 5 is configured to generate electricity by driving the turbine 2. Fuel is supplied from the fuel supply system 4 to the combustor 3 in accordance with the power generation demand input to the cogeneration system 10, and the calorific value of the exhaust gas 13 discharged from the turbine 2 varies. More specifically, fuel is supplied from the fuel supply system 4 so that the temperature of the combustion chamber of the combustor 3 increases as the power generation demand increases, and the calorific value of the exhaust gas 13 increases as the power generation demand increases. It is understood that the power generation amount of the generator 5 is the load of the cogeneration system 10.

[0016] The fuel supply system 4 includes a startup fuel supply line 76 and a fuel gas supply line 78. The startup fuel supply line 76 is configured to guide startup fuel supplied by a startup fuel supply facility 77 to the combustor 3. The fuel gas supply line 78 is configured to guide fuel gas supplied by a fuel gas supply facility 79 to the combustor 3. The startup fuel is, for example, LP gas, heavy oil, light oil, kerosene, or a combination thereof. Another example of the startup fuel may be LNG. The fuel gas is, for example, off-gas, LP gas, hydrogen gas, ammonia gas, methane gas, or any combination of these gases.

[0017] The startup fuel supply line 76 and the fuel gas supply line 78 are provided with on-off valves 76A and 78A, respectively. By controlling the opening and closing of these on-off valves, the fuel supplied to the combustor 3 is selectively switched to either the startup fuel or the fuel gas. More specifically, at the start-up of the gas turbine 9, the on-off valve 76A is opened and the on-off valve 78A is closed. As a result, the startup fuel supply line 76 exclusively supplies the startup fuel to the combustor 3, and the combustor 3 exclusively burns one type of startup fuel. After the start-up of the gas turbine 9 is completed, the on-off valve 76A is closed and the on-off valve 78A is opened. As a result, the supply of the startup fuel is terminated, and the fuel gas supply line 78 supplies the fuel gas. Hereinafter, the startup fuel and the fuel gas may be collectively referred to simply as "fuel."

[0018] The cogeneration system 10 further includes a heat recovery boiler 14. The heat recovery boiler 14 is configured to generate boiler steam from boiler feedwater using exhaust gas 13, which is combustion gas 12 discharged from the turbine 2, as a heat source. The boiler feedwater is water to be supplied to the heat recovery boiler 14. The boiler steam discharged from the heat recovery boiler 14 is guided to a steam consumer 11 by a steam supply pipe 21. In this example, the steam consumer 11 is a steam turbine. In other examples, the steam consumer 11 may be a steam turbine of a combined cycle power plant or an industrial process device.

[0019] Although not an essential component of the present disclosure, the cogeneration system 10 includes a steam extraction pipe 130 for supplying boiler steam extracted from the steam supply pipe 21 to the combustor 3. The steam extraction pipe 130 illustrated in the figure includes an upstream steam pipe 131 for supplying the boiler steam to the head end (not shown) side of the combustor 3, and a downstream steam pipe 132 for supplying the boiler steam to the turbine 2 side of the combustor 3.

[0020] The cogeneration system 10 further includes a discharge line 57 through which the flue gas 13 discharged from the heat recovery boiler 14 flows, an exhaust line 29 for guiding the flue gas 13 flowing through the discharge line 57 to the exhaust tower 30, and a water recovery system 40 for recovering moisture in the flue gas 13 discharged from the discharge line 57. An exhaust damper 31 is provided in the exhaust line 29. While the exhaust damper 31 is closed, the flue gas 13 does not flow through the exhaust line 29 but is instead guided to the water recovery system 40. Details of the water recovery system 40 will be described later.

[0021] Although not essential components of the present disclosure, the cogeneration system 10 includes a make-up water tank 17 that stores water containing moisture recovered by the water recovery system 40 as boiler feedwater, a feedwater line 15 for supplying make-up water to the make-up water tank 17, a feedwater line 19 connected to the make-up water tank 17 and the heat recovery boiler 14, a feedwater pump 18 provided on the feedwater line 19, and an excess water line 22 for draining excess water in the feedwater line 19. The boiler feedwater stored in the make-up water tank 17 flows through the feedwater line 19 and is supplied to the heat recovery boiler 14. From the viewpoint of improving the efficiency of the cogeneration system 10, a high temperature of the boiler feedwater supplied to the heat recovery boiler 14 is preferable.

[0022] The cogeneration system 10 further includes a controller 90 for controlling various devices constituting the cogeneration system 10. The various devices controlled by the controller 90 include the on-off valves 76A and 78A and the exhaust damper 31. The controller 90 is configured as a computer and includes a processor, memory, and an external communication interface. The processor may be a CPU, a GPU, an MPU, a DSP, or a combination thereof. In other embodiments, the processor may be implemented as an integrated circuit such as a PLD, an ASIC, an FPGA, or an MCU. The memory (recording medium) is configured to temporarily or non-temporarily store various data and may be implemented, for example, by at least one of RAM, ROM, and flash memory. The processor executes various control processes according to instructions from a program loaded into the memory. The controller 90 may also be a DCS panel constituting one of multiple control panels constituting the cogeneration system 10.

[0023] <2. Water Recovery System 40> FIG. 2 is a schematic diagram of a water recovery system 40 according to an embodiment of the present disclosure. FIG. 3 is a schematic diagram of a first binary power generation system 110 according to an embodiment of the present disclosure. FIG. 4A is a schematic diagram of a water recovery system 40A (40) according to a first embodiment. FIG. 4B is a schematic diagram of a water recovery system 40B (40) according to a second embodiment. The water recovery systems 40A and 40B of this example include a first binary power generation system 110 (see FIG. 2) described below. However, the present disclosure is not limited thereto, and the water recovery systems 40A and 40B according to other examples may not include the first binary power generation system 110.

[0024] <2-1. Exhaust gas supply system for water recovery system 40> 2, the water recovery system 40 includes a water recovery device 33, an exhaust gas supply line 145 for guiding the exhaust gas 13 flowing through a discharge line 57 to the water recovery device 33, and a first binary power generation system 110 for generating power using the exhaust gas 13 flowing through the exhaust gas supply line 145 as a heat source. The water recovery device 33 is configured to recover moisture from the exhaust gas 13 by heat exchange between the exhaust gas 13 flowing in from the discharge line 57 and refrigerant water, which will be described later. The water recovery device 33 includes an exhaust gas inlet 331 connected to the discharge line 57.

[0025] The exhaust gas supply line 145 according to some embodiments includes a first exhaust gas line 141 for guiding the exhaust gas 13 to the first binary power generation system 110, a second exhaust gas line 142 for guiding the exhaust gas 13 discharged from the first binary power generation system 110 to the water recovery device 33, a bypass exhaust gas line 143 connected to the first exhaust gas line 141 and the second exhaust gas line 142 so as to bypass the first binary power generation system 110, and a combined exhaust gas line 144 connected to the exhaust gas inlet 331. The upstream end of the combined exhaust gas line 144 is connected to the second exhaust gas line 142 and the bypass exhaust gas line 143. The exhaust gas 13 flowing through the second exhaust gas line 142 and the bypass exhaust gas line 143 are joined at the upstream end of the combined exhaust gas line 144 and flow into the exhaust gas inlet 331.

[0026] The first binary power generation system 110 illustrated in FIG. 3 is configured to generate power using a Rankine cycle in which a first circulating low-boiling-point working medium, which is a first organic medium, circulates. The boiling point of the first circulating low-boiling-point working medium is lower than the boiling point of water. In this example, R-245fa (HFC-245fa) is used as the first circulating low-boiling-point working medium. In another example, the first circulating low-boiling-point working medium may be HFC-245ca.

[0027] The first binary power generation system 110 includes a first evaporator 111 for evaporating the first circulating low-boiling point working medium, a first turbine 112 configured to obtain rotational power from the evaporated first circulating low-boiling point working medium, a first generator 113 connected to the first turbine 112, and a first circulation line 119 for circulating the first circulating low-boiling point working medium between the first evaporator 111 and the first turbine 112.

[0028] The first evaporator 111 is configured to evaporate the first circulation line 119 using at least a portion of the flue gas 13 flowing from the heat recovery boiler 14 (see FIG. 1) toward the water recovery device 33 as a heat source. More specifically, the flue gas 13 guided by the first flue gas line 141 is used as the heat source of the first evaporator 111. The flue gas 13 used as the heat source in the first evaporator 111 is discharged to the second flue gas line 142. The greater the heat content of the flue gas 13 flowing into the first evaporator 111, the greater the heat input to the first evaporator 111 and the greater the power generation capacity of the first binary power generation system 110. The first evaporator 111 is configured by a fin-and-tube heat exchanger.

[0029] The first circulation line 119 is further provided with a first condenser 114 for condensing the first circulation low-boiling-point working medium discharged from the first turbine 112, and a first pump device 115. The first condenser 114 is configured to condense the first circulation line 119 using cooling water, such as seawater, supplied from a first cooling source 118. The first pump device 115 includes a first circulation pump 115A and a first flow regulation valve 115B. The rotation speed of the first circulation pump 115A and the aperture of the first flow regulation valve 115B are controlled by the above-mentioned controller 90, thereby controlling the flow rate of the first circulation low-boiling-point working medium sent to the first evaporator 111.

[0030] Returning to FIG. 2 , the water recovery system 40 further includes an exhaust gas damper 150 for controlling the exhaust gas flow rate ratio. Here, the exhaust gas flow rate ratio is the ratio between the flow rate of the exhaust gas 13 flowing into the first evaporator 111 of the first binary power generation system 110 and the flow rate of the exhaust gas 13 flowing through the bypass exhaust gas line 143. The exhaust gas damper 150 in this example includes a first exhaust gas damper 151 arranged in the first exhaust gas line 141, a second exhaust gas damper 152 arranged in the second exhaust gas line 142, and a bypass exhaust gas damper 153 arranged in the bypass exhaust gas damper 153. The opening degrees of these dampers are controlled by the controller 90, thereby adjusting the exhaust gas flow rate ratio and controlling the temperature of the exhaust gas 13 at the exhaust gas inlet 331 of the water recovery device 33 (a detailed example of temperature control of the exhaust gas 13 will be described later). The exhaust gas flow rate ratio changes depending on the load of the gas turbine 9, but while the gas turbine 9 is operating at rated speed (partial load operation), the flow rate of the exhaust gas 13 flowing into the first evaporator 111 is set to be equivalent to the ratio of the gas amount during partial load operation to the gas amount during rated operation, and the flow rate of the exhaust gas 13 flowing through the bypass exhaust gas line 143 is controlled so that the exhaust gas temperature at the inlet of the water recovery device becomes a predetermined temperature.

[0031] <2-2. Reclaimed water system of water recovery system 40> The water recovery device 33 shown in FIG. 2 is configured to recover moisture in the flue gas 13 as recovered water by bringing the flue gas 13, introduced by a combined flue gas line 144 of the flue gas supply line 145, into gas-liquid contact with the refrigerant water. As a more detailed example, the water recovery device 33 includes a heat exchanger vessel 135 into which the flue gas 13 and the refrigerant water flow, a sprinkler device 34 for sprinkling the refrigerant water inside the heat exchanger vessel 135, and a packing 35 located inside the heat exchanger vessel 135 below the sprinkler device 34. The heat exchanger vessel 135 is formed with the above-mentioned flue gas inlet 331. The refrigerant water sprinkled by the sprinkler device 34 exchanges heat with the flue gas 13 flowing in from the flue gas inlet 331 via the packing 35. This condenses the moisture in the flue gas 13. The condensed refrigerant water containing the moisture falls and accumulates as recovered water in a water tank 136 that forms the lower part of the heat exchanger vessel 135. The exhaust gas 13 from which moisture has been recovered is discharged from an exhaust gas outlet 332 provided at the top of the water recovery device 33.

[0032] The water recovery system 40 further includes a recovered water cooling system 50 including a recovered water cooler 55 for cooling the recovered water discharged from the water tank 136 of the water recovery device 33, a recovered water circulation line 43 for circulating the recovered water between the water recovery device 33 and the recovered water cooler 55, and a recovered water circulation pump 38 disposed in the recovered water circulation line 43. Details of the recovered water cooling system 50 will be described later. As an example, the recovered water circulation pump 38 is a pump equipped with an inverter, and the rotation speed of the recovered water circulation pump 38 is controlled by a controller 90.

[0033] The recovered water circulation line 43 in this example includes a recovered water discharge line 39 for guiding recovered water discharged from the water tank 136 to the recovered water cooler 55, and a recovered water supply line 42 for guiding the recovered water cooled by the recovered water cooler 55 as refrigerant water to the heat exchange vessel 135. In the example of FIG. 2, the recovered water circulation pump 38 is disposed on the recovered water discharge line 39. Note that the refrigerant water is recovered water cooled by the recovered water cooler 55. When multiple recovered water coolers 55 are arranged in series (see FIG. 4B), the recovered water flowing from the most downstream recovered water cooler 55 toward the water recovery device 33 is the refrigerant water. When multiple recovered water coolers 55 are arranged in parallel (see FIG. 4C), the recovered water flowing from each recovered water cooler 55 toward the water recovery device 33 is the refrigerant water. The heat exchange vessel 135 of the water recovery device 33 includes a refrigerant water inlet 333 through which the refrigerant water flows.

[0034] An outline of the operation of the water recovery system 40 having the above configuration is as follows (see FIGS. 1 to 3). While the exhaust damper 31 is closed, a portion of the flue gas 13 discharged from the heat recovery boiler 14 flows into the first evaporator 111 via the first flue gas line 141, and the remaining flue gas 13 flows through the bypass flue gas line 143. The flue gas 13 cooled in the first evaporator 111 flows through the second flue gas line 142 and then merges with the flue gas 13 flowing through the bypass flue gas line 143. The flue gas 13 is then guided to the water recovery device 33 through the merged flue gas line 144. The flue gas 13 that flows into the water recovery device 33 has moisture recovered by heat exchange with the refrigerant water, and the flue gas 13 is discharged from the flue gas outlet 332.

[0035] On the other hand, recovered water discharged from the water recovery device 33 flows into the recovered water cooler 55 via the recovered water discharge line 39 by driving the recovered water circulation pump 38. The recovered water cooled by the recovered water cooler 55 flows through the recovered water supply line 42 as refrigerant water and returns to the water recovery device 33.

[0036] Furthermore, the first circulating low boiling point working medium evaporated by heat exchange with the exhaust gas 13 in the first evaporator 111 of the first binary power generation system 110 flows into the first turbine 112, and the first generator 113 generates power. The first circulating low boiling point working medium discharged from the first turbine 112 is condensed in the first condenser 114, and the condensed liquid-phase first circulating low boiling point working medium is returned to the first evaporator 111 by the power of the first pump device 115.

[0037] According to the above configuration, the first binary power generation system 110 generates power by utilizing the boiler outlet exhaust gas calorific value, which is the calorific value held in the exhaust gas 13 at the outlet of the heat recovery boiler 14, thereby improving the power generation efficiency of the entire cogeneration system 10. Furthermore, even if the boiler outlet exhaust gas calorific value fluctuates in accordance with load fluctuations on the gas turbine 9, the first binary power generation system 110 recovers a portion of the boiler outlet exhaust gas calorific value, thereby suppressing an increase in the water recovery inlet exhaust gas calorific value, which is the calorific value held in the exhaust gas 13 at the exhaust gas inlet 331. This suppresses an increase in the amount of heat exchange required between the exhaust gas 13 and the refrigerant water in the water recovery device 33, and suppresses an increase in the circulating flow rate of the recovered water in the recovered water circulation line 43. This suppresses the amount of power consumption of the water recovery system 40, further improving the power generation efficiency of the entire cogeneration system 10. In addition, even if the load on the gas turbine 9 fluctuates, the fluctuation in the heat content of the exhaust gas at the water recovery inlet can be suppressed, so the responsiveness of the water recovery system 40 to fluctuations can be relatively improved compared to when the first binary power generation system 110 is not installed.

[0038] The exhaust gas supply line 145 does not have to include the bypass exhaust gas line 143. In this case, all of the exhaust gas 13 flowing through the discharge line 57 flows into the first evaporator 111 via the first exhaust gas line 141, and the exhaust gas 13 discharged from the first evaporator 111 flows into the water recovery device 33 via the second exhaust gas line 142. Even in this case, the above-mentioned advantages can be obtained.

[0039] Furthermore, the water recovery system 40, which includes the first exhaust gas line 141, the second exhaust gas line 142, the bypass exhaust gas line 143, and the exhaust gas damper 150, can adjust the exhaust gas flow rate ratio in response to fluctuations in the calorific value of the exhaust gas at the boiler outlet. Therefore, even if the load on the gas turbine 9 fluctuates, the temperature of the exhaust gas 13 at the exhaust gas inlet 331 can be stabilized. This prevents an increase in the circulating flow rate of the recovered water in the recovered water circulation line 43, thereby reducing the power consumption of the water recovery system 40 and improving the power generation efficiency of the entire cogeneration system 10. Furthermore, if an abnormality occurs in the first binary power generation system 110, the first exhaust gas line 141 and the second exhaust gas line 142 can be closed to prevent the exhaust gas 13 from flowing through the first exhaust gas line 141 and the second exhaust gas line 142, and instead allow the exhaust gas 13 to flow through the water recovery device 33. This allows inspection and repair of the first binary power generation system 110 while the water recovery system 40 continues operating.

[0040] Furthermore, when the first circulation low-boiling point working medium is R-245fa (HFC-245fa), the ozone depletion potential of R-245fa is zero and the global warming potential of R-245fa is relatively low, so that the water recovery system 40 can reduce adverse effects on the surrounding environment.

[0041] <2-3. Additional Components of the Water Recovery System 40> 3, the water recovery system 40 may further include a water recovery device exhaust gas inlet temperature sensor 92. The water recovery device exhaust gas inlet temperature sensor 92 is configured to measure the temperature of the exhaust gas 13 flowing through the combined exhaust gas line 144. In other words, the water recovery device exhaust gas inlet temperature sensor 92 is configured to measure the temperature of the exhaust gas 13 flowing from a position P1 where the second exhaust gas line 142 is connected to the bypass exhaust gas line 143 toward the exhaust gas inlet 331 of the water recovery device 33. Note that even when the water recovery device exhaust gas inlet temperature sensor 92 is provided at the exhaust gas inlet 331, it is understood that the measured temperature indicates the temperature of the exhaust gas 13 flowing from the position P1 toward the exhaust gas inlet 331.

[0042] The controller 90 is configured to control the flue gas inlet temperature, which is the temperature measured by the water recovery device flue gas inlet temperature sensor 92. More specifically, the controller 90 is configured to control the flue gas damper 150 so that the flue gas inlet temperature becomes a first specified temperature. More specifically, if the flue gas inlet temperature exceeds the first specified temperature, the controller 90 increases the opening degrees of the first flue gas damper 151 and the second flue gas damper 152 and decreases the opening degree of the bypass flue gas damper 153. This increases the flow rate of the flue gas 13 cooled in the first evaporator 111, thereby decreasing the water recovery device flue gas inlet temperature. Conversely, if the water recovery device flue gas inlet temperature is below the first specified temperature, the controller 90 decreases the opening degrees of the first flue gas damper 151 and the second flue gas damper 152 and increases the opening degree of the bypass flue gas damper 153. This increases the water recovery device flue gas inlet temperature. The exhaust gas damper 150 does not necessarily have to include either the first exhaust gas damper 151 or the second exhaust gas damper 152. Even in this case, it is possible to control the exhaust gas flow rate ratio.

[0043] According to the above configuration, even if the load on the gas turbine 9 fluctuates, the controller 90 can adjust the exhaust gas flow rate ratio by controlling the exhaust gas damper 150, and the temperature of the exhaust gas 13 flowing into the water recovery device 33 can be adjusted. This makes it possible to stabilize the temperature of the exhaust gas 13 at the exhaust gas inlet 331 at the first specified temperature, and to suppress an increase in the circulating flow rate of the recovered water in the recovered water circulation line 43. Therefore, the amount of power consumed by the water recovery system 40 can be reduced.

[0044] 3 is configured to control the flow rate of the first circulating low-boiling-point working medium discharged from the first pump device 115 so that the temperature at the exhaust gas inlet of the water recovery device becomes a first specified temperature. More specifically, if the temperature at the exhaust gas inlet of the water recovery device exceeds the first specified temperature, the controller 90 controls the first pump device 115 to increase the circulation flow rate of the first circulating low-boiling-point working medium. More specifically, the controller 90 increases the rotation speed of the first circulating pump 115A and increases the aperture of the first flow control valve 115B so that the circulation flow rate of the first circulating low-boiling-point working medium increases in response to an increase in the flow rate of the exhaust gas 13 flowing into the first evaporator 111. As a result, both the flow rate and temperature of the exhaust gas 13 discharged from the first evaporator 111 decrease, and the temperature at the exhaust gas inlet of the water recovery device decreases. Conversely, if the temperature at the exhaust gas inlet of the water recovery device is lower than the first specified temperature, the controller 90 controls the first pump device 115 to reduce the circulation flow rate of the first circulating low-boiling-point working medium, thereby increasing the temperature at the exhaust gas inlet of the water recovery device.

[0045] The flow rate of the exhaust gas 13 flowing into the first evaporator 111 is determined by the controller 90 acquiring a signal indicating the opening degree of the first exhaust gas damper 151 from the first exhaust gas damper 151. Alternatively, the flow rate of the exhaust gas 13 flowing into the first evaporator 111 may be determined based on the measurement results of an exhaust gas flow meter (not shown) arranged in the first exhaust gas line 141.

[0046] According to the above configuration, even if the load on the gas turbine 9 fluctuates, the controller 90 adjusts the temperature of the exhaust gas 13 flowing through the second exhaust gas line 142 through control of the first pump device 115. This makes it possible to stabilize the temperature of the exhaust gas 13 at the exhaust gas inlet 331. Since it is possible to suppress an increase in the circulating flow rate of the recovered water in the recovered water circulation line 43, it is possible to reduce the amount of power consumed by the water recovery system 40.

[0047] As shown in FIG. 2 , although not a required component of the present disclosure, the water recovery system 40 further includes a water recovery device exhaust gas outlet temperature sensor 99. The water recovery device exhaust gas outlet temperature sensor 99 is configured to measure the temperature of the flue gas 13 at the exhaust gas outlet 332. In this example, the controller 90 controls the recovered water circulation pump 38 so that the water recovery device exhaust gas outlet temperature, which is the temperature measured by the water recovery device exhaust gas outlet temperature sensor 99, becomes a specified discharge temperature. More specifically, when the water recovery device exhaust gas outlet temperature exceeds the specified discharge temperature, the controller 90 increases the rotation speed of the recovered water circulation pump 38 to increase the flow rate of the refrigerant water flowing into the water recovery device 33. This increases the amount of heat exchange between the flue gas 13 and the refrigerant water, and decreases the water recovery device exhaust gas outlet temperature. Conversely, when the water recovery device exhaust gas outlet temperature is lower than the specified discharge temperature, the controller 90 decreases the rotation speed of the recovered water circulation pump 38. This increases the water recovery device exhaust gas outlet temperature.

[0048] The specified discharge temperature is set based on the following idea: The lower the specified discharge temperature is set, the greater the amount of temperature drop of the exhaust gas 13 in the water recovery device 33, and therefore the amount of moisture recovered by the water recovery device 33. However, the lower the specified discharge temperature is set, the greater the cooling heat load on the recovered water cooling system 50, and the greater the power consumption of the recovered water cooling system 50. Therefore, in this example, the heat exchange amount in the water recovery device 33 is specified to balance the increase in the amount of moisture recovered by the water recovery device 33 and the increase in the power consumption of the recovered water cooling system 50, and the specified discharge temperature is set. However, the present disclosure is not limited to setting the specified discharge temperature based on the above-mentioned concept. For example, if the cogeneration system 10 is installed in an area where regulations are in place that stipulate the temperature of the exhaust gas 13 released into the atmosphere, the specified discharge temperature is set in accordance with the regulations.

[0049] As shown in FIG. 2 , although not an essential component of the present disclosure, the water recovery system 40 further includes a water supply line 37 for guiding recovered water to the makeup water tank 17, and the water supply line 37 includes a high-temperature water supply line 44 and a low-temperature water supply line 47. The high-temperature water supply line 44 is connected to a recovered water discharge line 39 and is configured to guide the recovered water removed from the recovered water discharge line 39 to the makeup water tank 17. The recovered water removed from the recovered water discharge line 39 has a relatively high temperature because it contains heat recovered from the exhaust gas 13. The low-temperature water supply line 47 is connected to a recovered water supply line 42 and is configured to guide the recovered water removed from the recovered water supply line 42 to the makeup water tank 17. The recovered water removed from the recovered water supply line 42 has been subjected to cooling treatment by a recovered water cooler 55 and is therefore at a relatively low temperature.

[0050] The low-temperature feedwater line 47 is provided with a water treatment device 46, a component of the water recovery system 40. The water treatment device 46 is configured to treat the recovered water flowing through the low-temperature feedwater line 47 to remove impurities, such as sulfur, which can cause corrosion. Impurities are generated during combustion in the combustor 3 and may be mixed into the flue gas 13. At least some of these impurities are dissolved in the recovered water through heat exchange between the flue gas 13 and the refrigerant water in the water recovery device 33. The water treatment device 46 removes impurities from the recovered water, thereby preventing impurities from being contained in the boiler feedwater stored in the makeup water tank 17. In general, the lower the temperature of the water to be treated, the better the impurity removal performance of the water treatment device 46. If the temperature of the recovered water is high, the ion exchange resin 146 constituting the water treatment device 46 may be damaged, which may reduce the impurity removal performance.

[0051] A high-temperature feedwater on-off valve 48 is provided on the high-temperature feedwater line 44, and a low-temperature feedwater on-off valve 45 is provided on the low-temperature feedwater line 47. For example, when LPG is supplied to the combustor 3 as fuel for starting the gas turbine 9, the amount of impurities mixed in the exhaust gas 13 is below a permissible value. In this case, the high-temperature feedwater on-off valve 48 is opened, and high-temperature recovered water that does not require impurity removal treatment flows into the makeup water tank 17 via the high-temperature feedwater line 44 (at this time, the low-temperature feedwater on-off valve 45 is closed). Since the temperature of the boiler feedwater supplied from the makeup water tank 17 to the exhaust heat recovery boiler 14 can be increased, the efficiency of the cogeneration system 10 is improved.

[0052] On the other hand, when off-gas is supplied to the combustor 3 as fuel gas after the gas turbine 9 has started up, the amount of impurities in the exhaust gas 13 may exceed the allowable value and fall below the allowable upper limit. In this case, the high-temperature feedwater on-off valve 48 is closed, the low-temperature feedwater on-off valve 45 is opened, and low-temperature recovered water that requires impurity removal treatment flows into the makeup water tank 17 via the water treatment device 46 provided in the low-temperature feedwater line 47. This prevents impurities from adhering to the equipment that constitutes the cogeneration system 10, such as the feedwater line 19 and the heat recovery boiler 14, and suppresses deterioration of the cogeneration system 10.

[0053] The present disclosure is not limited to the above example with regard to the opening and closing timing of the high-temperature feedwater valve 48 and the low-temperature feedwater valve 45. For example, when heavy oil is supplied to the combustor 3 as the startup fuel, the amount of impurities contained in the flue gas 13 exceeds the allowable upper limit. In this case, the controller 90 opens the exhaust damper 31 and closes the exhaust gas damper 150. At this time, the flue gas 13 is discharged from the exhaust stack 30 without flowing to the water recovery system 40. When the startup fuel is subsequently switched from heavy oil to kerosene, the impurities in the flue gas 13 exceed the allowable limit but fall below the allowable upper limit, and the low-temperature feedwater valve 45 is opened (the high-temperature feedwater valve 48 remains closed). When hydrogen gas is subsequently supplied to the combustor 3 as the fuel gas from the startup fuel, the amount of impurities mixed into the flue gas 13 falls below the allowable limit. At this time, the high-temperature feedwater valve 48 is opened and the low-temperature feedwater valve 45 is closed.

[0054] According to the above configuration, the high-temperature feedwater line 44 guides recovered water that does not require impurity removal to the makeup water tank 17. Because this recovered water is high-temperature water that flows upstream of the recovered water cooler 55, a decrease in the temperature of the boiler feedwater stored in the makeup water tank 17 can be suppressed. As a result, the amount of heat required for the heat recovery steam generator 14 to generate boiler steam can be reduced, improving the thermal efficiency of the cogeneration system 10. On the other hand, the low-temperature feedwater line 47 guides recovered water that requires impurity removal to the makeup water tank 17 via the water treatment device 46. Because this recovered water is low-temperature water that flows downstream of the recovered water cooler 55, a decrease in the impurity removal function of the water treatment device 46 can be suppressed. Therefore, even if the recovered water recovered in the water recovery device 33 contains impurities, the recovered water can be supplied to the makeup water tank 17 without being discarded. As described above, the water recovery system 40 is realized, which can reuse recovered water recovered from the flue gas 13 as boiler feedwater without waste and improves power generation efficiency. The recovered water includes steam injection water and combustion product water. Steam injection water is reused as boiler feed water, while combustion product water is discharged outside the system as surplus water and reused.

[0055] <2-4. Recovered water cooling system 50A (50) according to the first embodiment> FIG. 4A is a schematic diagram of a water recovery system 40A (40) including a recovered water cooling system 50A (50) according to the first embodiment.

[0056] As shown in FIG. 4A, the recovered water cooling system 50A includes a second binary power generation system 220. The system is configured to generate power using a Rankine cycle in which a second circulating low-boiling-point working medium, which is a second organic medium, circulates. The boiling point of the second circulating low-boiling-point working medium is lower than that of water. In this example, R-245fa (HFC-245fa) is used as the second circulating low-boiling-point working medium. In another example, the second circulating low-boiling-point working medium may be HFC-245ca.

[0057] The second binary power generation system 220 comprises a second evaporator 221 for evaporating the second circulating low boiling point working medium, a second turbine 222 configured to obtain rotational power from the evaporated second circulating low boiling point working medium, a second generator 223 coupled to the second turbine 222, and a second circulation line 229 for circulating the second evaporator 221 and the second turbine 222.

[0058] The second evaporator 221 included in the recovered water cooler 55A (55) is configured to evaporate the second circulating low-boiling point working medium using at least a portion of the recovered water flowing through the recovered water circulation line 43A (43) of the water recovery system 40A (40) as a heat source. More specifically, the recovered water circulation line 43A includes a power generation recovered water supply line 61 for guiding the recovered water discharged from the water storage tank 136 to the second evaporator 221, a power generation recovered water discharge line 62 for guiding the recovered water discharged from the second evaporator 221 to the water recovery device 33, and a power generation recovered water bypass line 63 connected to the power generation recovered water supply line 61 and the power generation recovered water discharge line 62 so as to bypass the second evaporator 221. In the example of FIG. 4A , the recovered water discharge line 39 is connected to the power generation recovered water supply line 61 and the power generation recovered water bypass line 63, and the recovered water supply line 42 is connected to the power generation recovered water discharge line 62 and the power generation recovered water bypass line 63. In the example shown in the same figure, the refrigerant water, which is the recovered water discharged from the second evaporator 221 (i.e., recovered water cooler 55A), is led to the water recovery device 33 via the power generation recovered water discharge line 62 and the recovered water supply line 42 in this order.

[0059] The second evaporator 221 is, for example, a plate-type heat exchanger. The plate-type heat exchanger may be a counter-flow type in which the recovered water and the second circulating low-boiling-point working medium flow in opposite directions, or a parallel-flow type in which the recovered water and the second circulating low-boiling-point working medium flow in the same direction.

[0060] The second circulation line 229 is further provided with a second condenser 224 for condensing the second circulation low boiling point working medium discharged from the second turbine 222, and a second pump device 225. The second condenser 224 is configured to condense the second circulation low boiling point working medium using cooling water, such as seawater or LNG cold water, supplied from a second cooling source 228. The second pump device 225 is configured to return the liquid-phase second circulation low boiling point working medium discharged from the second condenser 224 to the second evaporator 221. The second pump device 225 includes a second circulation pump 225A and a second flow control valve 225B. The rotation speed of the second circulation pump 225A and the aperture of the second flow control valve 225B are controlled by a controller 90, thereby controlling the flow rate of the second circulation low boiling point working medium sent to the second evaporator 221.

[0061] The recovered water circulation line 43A further includes a recovered water flow control valve 65 for controlling the recovered water flow rate ratio. Here, the recovered water flow rate ratio is the ratio between the flow rate of recovered water flowing into the second evaporator 221 and the flow rate of recovered water flowing through the recovered water bypass line 63. In this example, the recovered water flow control valve 65 has a supply flow rate valve 67 arranged in the power generation recovered water supply line 61, a discharge flow control valve 68 arranged in the power generation recovered water discharge line 62, and a bypass flow control valve 69 arranged in the recovered water bypass line 63. The apertures of these flow control valves are controlled by the controller 90 to adjust the recovered water flow rate ratio and control the temperature of the refrigerant water at the refrigerant water inlet 333 (a detailed example of refrigerant water temperature control will be described later).

[0062] According to the above configuration, the second binary power generation system 220 generates power by utilizing the heat contained in the recovered water discharged from the water recovery device 33, thereby further improving the power generation efficiency of the entire cogeneration system 10. Furthermore, according to the configuration in which the recovered water flow control valve 65 is provided, it is possible to change the recovered water flow rate ratio even if the temperature of the recovered water discharged from the water recovery device 33 fluctuates. Therefore, even if the temperature of the recovered water discharged from the water recovery device 33 fluctuates, the temperature of the refrigerant water flowing into the water recovery device 33 can be stabilized. Therefore, it is possible to recover moisture from the flue gas 13 in the water recovery device 33 while maintaining the temperature of the flue gas 13 discharged from the water recovery device 33 at the desired specified discharge temperature. The recovered water circulation line 43A does not have to include the recovered water bypass line 63. In this case, all of the recovered water flowing through the recovered water discharge line 39 may flow into the second evaporator 221 via the power generation recovered water supply line 61. Even in this case, the above-mentioned advantages can be obtained.

[0063] Furthermore, when the second circulating low-boiling point working medium is R-245fa (HFC-245fa), the ozone depletion potential of R-245fa is zero and the global warming potential of R-245fa is relatively low, so that the water recovery system 40 can reduce adverse effects on the surrounding environment.

[0064] Although not an essential component of the first embodiment, the water recovery system 40A may further include a water recovery device inlet refrigerant water temperature sensor 93. The water recovery device inlet refrigerant water temperature sensor 93 is configured to measure the temperature of the recovered water (refrigerant water) flowing through the recovered water supply line 42. In other words, the water recovery device inlet refrigerant water temperature sensor 93 is configured to measure the temperature of the recovered water flowing from position P2 in the recovered water circulation line 43A to the water recovery device 33 at the point where the power generation recovered water discharge line 62 is connected to the recovered water bypass line 63. Note that even if the water recovery device inlet refrigerant water temperature sensor 93 is provided at the refrigerant water inlet 333, it will be understood that the measured temperature indicates the recovered water (refrigerant water) flowing from position P2 toward the water recovery device 33.

[0065] The controller 90 is configured to control the water recovery unit inlet refrigerant water temperature, which is the temperature measured by the water recovery unit inlet refrigerant water temperature sensor 93. More specifically, the controller 90 is configured to control the recovered water flow control valve 65 so that the water recovery unit inlet refrigerant water temperature becomes a second specified temperature. Even more specifically, if the water recovery unit inlet refrigerant water temperature exceeds the second specified temperature, the controller 90 increases the openings of the supply flow valve 67 and the discharge flow control valve 68 and decreases the opening of the bypass flow control valve 69. This increases the flow rate of the flue gas 13 cooled in the second evaporator 221, thereby decreasing the water recovery unit inlet refrigerant water temperature. Conversely, if the water recovery unit inlet refrigerant water temperature is lower than the second specified temperature, the controller 90 decreases the openings of the supply flow valve 67 and the discharge flow control valve 68 and increases the opening of the bypass flow control valve 69. This increases the water recovery unit inlet refrigerant water temperature.

[0066] According to the above configuration, even if the temperature of the recovered water discharged from the water recovery device 33 fluctuates, the controller 90 can adjust the recovered water flow rate ratio by controlling the recovered water flow adjustment valve 65, and can adjust the temperature of the refrigerant water flowing into the water recovery device 33. This makes it possible to stabilize the temperature of the refrigerant water at the refrigerant water inlet 333 of the water recovery device 33 at the second specified temperature, and to set the temperature of the exhaust gas 13 discharged from the water recovery device 33 to the desired specified discharge temperature. The recovered water flow adjustment valve 65 does not have to include the first exhaust gas damper 151, the second exhaust gas damper 152, and the bypass flow adjustment valve 69. In this case, the recovered water flow adjustment valve 65 may be a three-way valve located at the connection point between the power generation recovered water supply line 61 and the recovered water bypass line 63. Even in this case, the recovered water flow rate ratio can be adjusted, and the above-mentioned advantages can be obtained.

[0067] The controller 90 shown in FIG. 4A is configured to control the flow rate of the second circulating low-boiling-point working medium discharged from the second pump device 225 so that the refrigerant water temperature at the inlet of the water recovery device becomes equal to a second specified temperature. More specifically, if the refrigerant water temperature at the inlet of the water recovery device exceeds the second specified temperature, the controller 90 controls the second pump device 225 to increase the circulation flow rate of the second circulating low-boiling-point working medium. More specifically, the controller 90 increases the rotation speed of the second circulation pump 225A and the aperture of the second flow control valve 225B so that the circulation flow rate of the second circulating low-boiling-point working medium increases in response to an increase in the flow rate of the recovered water flowing into the second evaporator 221. As a result, both the flow rate and temperature of the recovered water discharged from the second evaporator 221 decrease, and the refrigerant water temperature at the inlet of the water recovery device decreases. Conversely, if the refrigerant water temperature at the inlet of the water recovery device is lower than the second specified temperature, the controller 90 controls the second pump device 225 to reduce the circulation flow rate of the second circulating low-boiling-point working medium, thereby increasing the refrigerant water temperature at the inlet of the water recovery device.

[0068] The flow rate of the recovered water flowing into the second evaporator 221 is determined based on the measurement results of a flow meter (not shown) arranged in the recovered water discharge line 39 or the power generation recovered water supply line 61. Alternatively, the flow rate of the recovered water flowing into the second evaporator 221 may be determined by the controller 90 acquiring an opening signal indicating the opening degree of the recovered water flow adjustment valve 65 from the recovered water flow adjustment valve 65.

[0069] According to the above configuration, even if the temperature of the recovered water discharged from the water recovery device 33 fluctuates, the controller 90 adjusts the temperature of the recovered water flowing through the recovered water supply line 42 and the recovered water circulation line 43A through control of the second pump device 225. This makes it possible to stabilize the temperature of the refrigerant water flowing into the water recovery device 33 at the second specified temperature, and to make the temperature of the exhaust gas 13 discharged from the water recovery device 33 the desired specified discharge temperature.

[0070] <2-5. Recovered water cooling system 50B (50) according to the second embodiment> 4B is a schematic diagram of a water recovery system 40B (40) including a recovered water cooling system 50B (50) according to a second embodiment. The same components shown in FIG. 4B as those in FIG. 4A are given the same numbers as those in FIG. 4A, and descriptions of these components may be omitted below.

[0071] The recovered water cooling system 50B includes an external water cooler 23A (23) in addition to the second binary power generation system 220 described above. More specifically, the recovered water cooler 55B (55) of the recovered water cooling system 50B further includes the external water cooler 23A in addition to the second evaporator 221. The recovered water flowing into the external water cooler 23A includes recovered water flowing into the second evaporator 221 (i.e., recovered water flowing through the recovered water discharge line 39) and recovered water flowing through the recovered water bypass line 63. More specifically, the recovered water circulation line 43B (43) of the water recovery system 40B further includes the recovered water discharge line 39, the recovered water bypass line 63, and a connection line 26 connected to the external water cooler 23A. The recovered water cooled by external water in the external water cooler 23A is discharged as refrigerant water to the recovered water supply line 42 and flows into the water recovery device 33.

[0072] The water recovery system 40B further includes an external water supply line 24 for supplying external water to the external water-using cooler 23A, and an external water supply pump 25 arranged in the external water supply line 24. The external water supply pump 25 is a pump equipped with an inverter, and its rotation speed is controlled by a controller 90. The controller 90 increases the rotation speed of the external water supply pump 25 when the refrigerant water temperature at the inlet of the water recovery device exceeds a second specified temperature, and decreases the rotation speed of the external water supply pump 25 when the refrigerant water temperature at the inlet of the water recovery device is below the second specified temperature.

[0073] 4B, the external water cooler 23A is disposed downstream of the second evaporator 221 and the recovered water bypass line 63, but the present disclosure is not limited to this. The external water cooler 23A may be disposed upstream of the second evaporator 221 and the recovered water bypass line 63.

[0074] According to the above configuration, the second evaporator 221 and the external water cooler 23A perform the cooling function of the recovered water, thereby distributing the cooling heat load of the second binary power generation system 220. Furthermore, if an abnormality occurs in the second binary power generation system 220, the supply flow valve 67 and the discharge flow control valve 68 are closed to stop the recovered water from flowing to the second evaporator 221, and only the external water cooler 23A can perform the cooling function of the recovered water. This allows inspection and repair of the second binary power generation system 220 to be performed while the water recovery system 40 continues to operate.

[0075] <2-6. Recovered water cooling system 50C (50) according to the third embodiment> 4C is a schematic diagram of a water recovery system 40C (40) including a recovered water cooling system 50C (50) according to a third embodiment. The same components shown in FIG. 4C as those in FIG. 4B are given the same numbers as those in FIG. 4B, and descriptions of these components may be omitted below.

[0076] The recovered water cooling system 50C includes an external water use cooler 23B (23) in addition to the above-mentioned second binary power generation system 220. The configuration of the external water use cooler 23B is the same as the configuration of the external water use cooler 23A, but the recovered water cooling system 50C differs from the recovered water cooling system 50B in that the external water use cooler 23B is provided in parallel with the second evaporator 221.

[0077] More specifically, the recovered water circulation line 43C(43) of the water recovery system 40C(40) includes the recovered water discharge line 39, recovered water bypass line 63, power generation recovered water supply line 61, power generation recovered water discharge line 62, and recovered water supply line 42 described above, as well as a recovered water extraction line 81 and a recovered water return line 82. The recovered water extraction line 81 is configured to guide the recovered water extracted from the power generation recovered water supply line 61 to the external water use cooler 23B. The recovered water return line 82 is configured to return the recovered water (refrigerant water) discharged from the external water use cooler 23B to the power generation recovered water discharge line 62. The refrigerant water discharged from the external water use cooler 23B merges with the refrigerant water discharged from the second evaporator 221 at the power generation recovered water discharge line 62. The refrigerant water flowing through the power generation recovered water discharge line 62 is supplied to the water recovery device 33 via the recovered water supply line 42.

[0078] Furthermore, the recovered water cooling system 50C includes a recovered water flow control valve 83 provided in the recovered water extraction line 81, and a recovered water flow control valve 84 provided in the recovered water return line 82. Note that only one of the recovered water flow control valves 83, 84 may be provided.

[0079] According to the above configuration, the second evaporator 221 and the external water cooler 23B perform the cooling function of the recovered water, thereby distributing the cooling heat load of the second binary power generation system 220. Furthermore, if an abnormality occurs in the second binary power generation system 220, the supply flow valve 67 and the discharge flow control valve 68 are closed to stop the recovered water from flowing to the second evaporator 221, and only the external water cooler 23B can perform the cooling function of the recovered water. This allows inspection and repair of the second binary power generation system 220 to be performed while the water recovery system 40 continues to operate.

[0080] <3. Power generation efficiency of the water recovery system 40> Fig. 5 is a graph showing the relationship between the flow rate of the exhaust gas 13 and the amount of power recovered (power generated) by the water recovery system 40A according to an embodiment of the present disclosure. Fig. 6 is a graph showing the relationship between the flow rate of the exhaust gas 13 and the cooling heat load of the water recovery system 40A according to an embodiment of the present disclosure. The horizontal axis of both graphs indicates the ratio (%) of the flow rate of the exhaust gas 13 flowing into the first evaporator 111 to the flow rate of the exhaust gas 13 flowing through the combined exhaust gas line 144. Hereinafter, this ratio may be referred to as the "first binary system exhaust gas supply ratio." Both graphs are obtained by simulation.

[0081] 5, line L1 indicates the amount of power recovered by the first binary power generation system 110, line L2 indicates the amount of power recovered by the second binary power generation system 220, and line L3 indicates the sum of the amount of power recovered by the first binary power generation system 110 and the amount of power recovered by the second binary power generation system 220. As can be seen from the figure, as the exhaust gas supply ratio of the first binary power generation system increases, the amount of power recovered by the second binary power generation system 220 decreases and the amount of power recovered by the first power generation system increases. The reason why the amount of power recovered by the second binary power generation system 220 decreases is because the amount of heat contained in the exhaust gas 13 flowing into the water recovery device 33 decreases, and the amount of heat input to the second binary power generation system 220 decreases. The reason why the amount of power recovered by the first binary power generation system 110 increases is because the amount of heat input to the first binary power generation system 110 increases.

[0082] As can be seen from FIG. 5 , the total power generation capacity of the first binary power generation system 110 and the second binary power generation system 220 increases as the first binary system exhaust gas supply ratio increases. The reason for this is as follows: The first evaporator 111 of the first binary power generation system 110 recovers heat at a medium-temperature recovery temperature difference of the exhaust gas 13 (a temperature difference of 90°C or more). On the other hand, the heat recovered by the second evaporator 221 of the second binary power generation system 220 is recovered at a low-temperature recovery temperature difference of the recovered water (a temperature difference of approximately 30 to 40°C). Therefore, the heat input amount that increases in the first evaporator 111 as the first binary system exhaust gas supply ratio increases exceeds the heat input amount that decreases in the second evaporator 221 as the first binary system exhaust gas supply ratio increases. Therefore, the total power generation capacity of the first binary power generation system 110 and the second binary power generation system 220 increases as the first binary system exhaust gas supply ratio increases.

[0083] 6, line segment M1 indicates the cooling heat load of the first binary power generation system 110, line segment M2 indicates the cooling heat load of the second binary power generation system 220, and line segment M3 indicates the sum of the cooling heat load of the first binary power generation system 110 and the cooling heat load of the second binary power generation system 220. The cooling heat load of the first binary power generation system 110 is the amount of heat held by the first circulating low boiling point working medium discharged in the first condenser 114, and the cooling heat load of the second binary power generation system 220 is the amount of heat held by the second circulating low boiling point working medium discharged in the second condenser 224.

[0084] The cooling heat loads of the first binary power generation system 110 and the second binary power generation system 220 are both heat quantities to be discharged outside the cogeneration system 10, and the power generation efficiency decreases as the cooling heat load increases. As can be seen from FIG. 6, even if the exhaust gas supply ratio to the first binary power generation system increases, the total cooling heat load of the first binary power generation system 110 and the second binary power generation system 220 does not increase but decreases slightly. This is because the power generation efficiency differs between the first binary power generation system 110 and the second binary power generation system 220. In other words, the heat source in the first binary power generation system 110 is exhaust gas 13, whose temperature level is 150°C to 230°C, and the recovery temperature difference is large at 90°C. Therefore, the power generation efficiency as a Rankine cycle with a low boiling point working fluid is high and the cooling heat load is small. On the other hand, the heat source of the second binary power generation system 220 is the recovered circulating water, and the temperature level is 60 to 70°C, the recovery temperature difference is small at 30 to 40°C, and the power generation efficiency of the Rankine cycle with a low boiling point working fluid is low, so the cooling heat load is correspondingly large. Due to this difference in power generation efficiency between the two, the total cooling heat load decreases slightly as the proportion of exhaust gas supplied to the first binary system increases.

[0085] From the graphs in Figures 5 and 6, it can be seen that for the entire power generation system including the first binary power generation system 110 and the second binary power generation system 220, the ratio of power generation recovery to cooling heat load increases as the exhaust gas supply ratio to the first binary system increases.

[0086] <4. Operation method of water recovery system 40> FIG. 7 is a flowchart showing a water recovery system operation process according to an embodiment of the present disclosure, which is an example of a method for operating the water recovery system 40. The water recovery system operation process is executed by at least one processor (hereinafter, sometimes simply referred to as the "processor") constituting the controller 90. The processor loads a predetermined program into memory and executes instructions contained in the program. The water recovery operation process will be described below using the water recovery system 40A (see FIG. 4A) equipped with the first binary power generation system 110 as an example.

[0087] The processor acquires the water recovery device exhaust gas inlet temperature based on the measurement result of the water recovery device exhaust gas inlet temperature sensor 92 (S11). In S11, the processor also executes a process to determine whether the acquired water recovery device exhaust gas inlet temperature is higher than the first specified temperature and / or whether the water recovery device exhaust gas inlet temperature is lower than the first specified temperature.

[0088] Next, the processor controls the flue gas damper 150 so that the water recovery device flue gas inlet temperature acquired in S11 becomes a first specified temperature (S13). More specifically, if it is determined in the determination process of S11 that the water recovery device flue gas inlet temperature exceeds the first specified temperature, the processor increases the opening degrees of the first flue gas damper 151 and the second flue gas damper 152, and decreases the opening degree of the bypass flue gas damper 153. On the other hand, if it is determined in the determination process of S11 that the water recovery device flue gas inlet temperature falls below the first specified temperature, the processor decreases the opening degrees of the first flue gas damper 151 and the second flue gas damper 152, and increases the opening degree of the bypass flue gas damper 153.

[0089] Next, the processor controls the first pump device 115 so that the water recovery device exhaust gas inlet temperature acquired in S11 becomes a first specified temperature (S15). More specifically, if it is determined in the determination process of S11 that the water recovery device exhaust gas inlet temperature exceeds the first specified temperature, the processor increases the rotation speed of the first circulation pump 115A and increases the opening degree of the first flow regulation valve 115B in accordance with an increase in the flow rate of the exhaust gas 13 flowing into the first evaporator 111. On the other hand, if it is determined in the determination process of S11 that the water recovery device exhaust gas inlet temperature falls below the first specified temperature, the processor decreases the rotation speed of the first circulation pump 115A and decreases the opening degree of the first flow regulation valve 115B in accordance with a decrease in the flow rate of the exhaust gas 13 flowing into the first evaporator 111.

[0090] Next, the processor acquires the water recovery device inlet refrigerant water temperature based on the measurement result of the water recovery device inlet refrigerant water temperature sensor 93 (S17). In S17, the processor also executes a process to determine whether the acquired water recovery device inlet refrigerant water temperature is larger than a second specified temperature. This determination process includes a process to determine whether the water recovery device inlet refrigerant water temperature is higher than the second specified temperature and / or a process to determine whether the water recovery device inlet refrigerant water temperature is lower than the second specified temperature.

[0091] The processor controls the recovered water flow adjustment valve 65 so that the water recovery unit inlet refrigerant water temperature acquired in S17 becomes a second specified temperature (S19). More specifically, if it is determined in the determination process of S17 that the water recovery unit inlet refrigerant water temperature exceeds the second specified temperature, the processor increases the apertures of the supply flow valve 67 and the discharge flow adjustment valve 68, and decreases the aperture of the bypass flow adjustment valve 69. On the other hand, if it is determined in the determination process of S17 that the water recovery unit inlet refrigerant water temperature falls below the second specified temperature, the processor decreases the apertures of the recovered water flow adjustment valve 65 and the discharge flow adjustment valve 68, and increases the aperture of the bypass flow adjustment valve 69.

[0092] The processor controls the second pump device 225 so that the water recovery device inlet refrigerant water temperature acquired in S17 becomes a second specified temperature (S21). More specifically, if it is determined in the determination process of S17 that the water recovery device inlet refrigerant water temperature exceeds the second specified temperature, the processor increases the rotation speed of the second circulation pump 225A and increases the opening degree of the second flow adjustment valve 225B in accordance with an increase in the flow rate of the recovered water flowing into the second evaporator 221. On the other hand, if it is determined in the determination process of S17 that the water recovery device inlet refrigerant water temperature falls below the second specified temperature, the processor decreases the rotation speed of the second circulation pump 225A and decreases the opening degree of the second flow adjustment valve 225B in accordance with a decrease in the flow rate of the recovered water flowing into the second evaporator 221.

[0093] Next, the processor acquires the water recovery device exhaust gas outlet temperature based on the detection result of the water recovery device exhaust gas outlet temperature sensor 99 (S23). In S23, the processor also executes a process to determine whether the acquired water recovery device exhaust gas outlet temperature is larger than a specified exhaust temperature. This determination process includes a process to determine whether the water recovery device exhaust gas outlet temperature is higher than the specified exhaust temperature and / or a process to determine whether the water recovery device exhaust gas outlet temperature is lower than the specified exhaust temperature.

[0094] Next, the processor controls the recovered water circulation pump 38 so that the water recovery device exhaust gas outlet temperature becomes a specified discharge temperature (S25). More specifically, if the determination process of S23 determines that the water recovery device exhaust gas outlet temperature exceeds the specified discharge temperature, the processor increases the rotation speed of the recovered water circulation pump 38. On the other hand, if the determination process of S23 determines that the water recovery device exhaust gas outlet temperature falls below the specified discharge temperature, the processor decreases the rotation speed of the recovered water circulation pump 38. Thereafter, the processor ends the water recovery system operation process.

[0095] <5. Method for Modifying the Water Recovery System 40 (First Example)> A method for retrofitting a water recovery system 40D (40) before retrofitting to a water recovery system 40A will be described with reference to Figures 2, 3, 4A, 8, and 9. Figure 8 is a flowchart showing a method for retrofitting a water recovery system 40D (40) according to one embodiment of the present disclosure. Figure 9 is a schematic diagram of a water recovery system 40D (40) according to one embodiment of the present disclosure.

[0096] Before describing the modification method, a water recovery system 40D will be described with reference to Figure 9. The water recovery system 40D does not include the first binary power generation system 110, first exhaust gas line 141, second exhaust gas line 142, and exhaust gas damper 150 shown in Figure 3. The discharge line 57 and the water recovery device 33 are connected by a pre-modification exhaust gas supply line 149. The water recovery system 40D also does not include the second binary power generation system 220, power generation recovered water supply line 61, power generation recovered water discharge line 62, and recovered water flow control valve 65 shown in Figure 4A. Instead, the water recovery system 40D includes a pre-modification recovered water cooling system 50D(50) including an external water-based cooler 23.

[0097] A method for modifying the water recovery system 40D will now be described. As shown in FIG. 8, first, a first binary power generation system adding step of adding a first binary power generation system 110 is executed (S31).

[0098] Next, an exhaust gas line adding step is performed to add a first exhaust gas line 141 and a second exhaust gas line 142 (S33). In S33, the inlet (upstream end) of the first exhaust gas line 141, in which the first exhaust gas damper 151 is arranged, is connected to the pre-modification exhaust gas supply line 149, and the outlet (downstream end) of the second exhaust gas line 142, in which the second exhaust gas damper 152 is arranged, is connected to the pre-modification exhaust gas supply line 149. Furthermore, in S33, a bypass exhaust gas damper 153 is arranged in a portion of the pre-modification exhaust gas supply line 149 between the inlet of the first exhaust gas line 141 and the outlet of the second exhaust gas line 142. As a result, the pre-modification exhaust gas supply line 149 functions as the bypass exhaust gas line 143 and the combined exhaust gas line 144.

[0099] Next, a second binary power generation system addition step is executed to add the second binary power generation system 220 (S35). In S35, as an example, the existing external water cooler 23 is removed and the second binary power generation system 220 is added.

[0100] Next, a power generation recovered water line addition step is performed in which a power generation recovered water supply line 61 and a power generation recovered water discharge line 62 are added (S37). In S37, the inlet (upstream end) of the power generation recovered water supply line 61, in which a supply flow valve 67 is disposed, is connected to the pre-modification recovered water discharge line 39, and the outlet (downstream end) of the power generation recovered water discharge line 62, in which a discharge flow adjustment valve 68 is disposed, is connected to the pre-modification recovered water discharge line 39. Furthermore, in S37, a bypass flow adjustment valve 69 is disposed in a portion of the pre-modification recovered water discharge line 39 between the inlet of the power generation recovered water supply line 61 and the outlet of the power generation recovered water discharge line 62. As a result, a portion of the pre-modification recovered water discharge line 39 can function as a recovered water bypass line 63. In addition, the recovered water circulation line 43, which is downstream of the outlet of the power generation recovered water discharge line 62, can function as the post-modification recovered water supply line 42.

[0101] Thereafter, the controller 90 is modified (S39). S39 may involve the addition of at least one DCS panel, or may involve a software update of the existing controller 90. By performing the above steps, the pre-modification water recovery system 40D is modified into the water recovery system 40A.

[0102] Steps S31 to S39 are performed by a worker, a robot arm operated by the worker, or a combination of these. In step S35, the second binary power generation system 220 may be added without removing the external water cooler 23. In this case, the pre-modification water recovery system 40D is modified into water recovery systems 40B and 40C (see FIGS. 4B and 4C). For example, when modifying the water recovery system 40D into the water recovery system 40C, after step S37 is performed, a step of adding a recovered water extraction line 81 and a recovered water return line 82 is performed.

[0103] <6. Method for Modifying the Water Recovery System 40 (Second Example)> A method for retrofitting a water recovery system 40E (40) before retrofitting to a water recovery system 40A will be described with reference to Figures 2, 3, 4A, 10, and 11. Figure 10 is a flowchart showing a method for retrofitting a water recovery system 40E (40) according to one embodiment of the present disclosure. Figure 11 is a schematic diagram of a water recovery system 40E (40) according to one embodiment of the present disclosure.

[0104] In addition to the configuration of water recovery system 40D, water recovery system 40E includes a first binary power generation system 110 and an exhaust gas damper 150. Water recovery system 40E does not include second binary power generation system 220, power generation recovered water supply line 61, power generation recovered water discharge line 62, or recovered water flow control valve 65. Instead, water recovery system 40E includes a pre-modification recovered water cooling system 50E (50) that includes an external water-using cooler 23 (the configuration of recovered water cooling system 50E is the same as that of recovered water cooling system 50D).

[0105] When such a water recovery system 40E is modified into a water recovery system 40A, steps S35 to S39 shown in Fig. 10 are executed. S35 to S39 in Fig. 10 are the same as S35 to S39 in Fig. 8, and therefore detailed description will be omitted.

[0106] <7. Summary> The contents of the above-described embodiments can be understood, for example, as follows.

[0107] 1) A water recovery system (40) according to at least one embodiment of the present disclosure includes: a water recovery device (33) for recovering moisture from an exhaust gas (13) discharged from a heat recovery boiler (14) of a gas turbine cogeneration system (10) by heat exchange between the exhaust gas and refrigerant water; a recovered water cooling system (50) including a recovered water cooler (55) for cooling the recovered water containing moisture recovered by the water recovery device; a recovered water circulation line (43) for guiding the recovered water discharged from the water recovery device to the recovered water cooler and for guiding the recovered water cooled by the recovered water cooler to the water recovery device as the refrigerant water; a recovered water circulation pump (38) disposed in the recovered water circulation line; A water recovery system comprising: The system further includes a first binary power generation system (110) including a first evaporator (111) for evaporating a first circulating low-boiling-point working medium, which is a first organic medium, a first turbine (112) configured to obtain rotational power from the evaporated first circulating low-boiling-point working medium, and a first generator (113) connected to the first turbine; The first evaporator is configured to evaporate the first circulating low-boiling-point working medium using, as a heat source, at least a portion of the exhaust gas flowing from the heat recovery boiler toward the water recovery device.

[0108] According to the configuration 1), the first binary power generation system generates power using the boiler outlet exhaust gas calorific value, which is the calorific value of the exhaust gas at the outlet of the heat recovery boiler. This improves the power generation efficiency of the entire gas turbine cogeneration system. Furthermore, even if the boiler outlet exhaust gas calorific value fluctuates due to changes in the gas turbine load, the first binary power generation system recovers a portion of the boiler outlet exhaust gas calorific value. This prevents an increase in the water recovery inlet exhaust gas calorific value, which is the calorific value of the exhaust gas at the exhaust gas inlet of the water recovery device. This prevents an increase in the amount of heat exchange required between the exhaust gas and the refrigerant water in the water recovery device and an increase in the circulating flow rate of the recovered water in the recovered water circulation line. This reduces the power consumption of the water recovery system and further improves the power generation efficiency of the entire gas turbine cogeneration system. Furthermore, because fluctuations in the water recovery inlet exhaust gas calorific value can be reduced even when the gas turbine load fluctuates, the responsiveness of the water recovery system to fluctuations is relatively improved compared to a system without the first binary power generation system.

[0109] 2) In some embodiments, the water recovery system described in 1) above, a first exhaust gas line (141) for guiding the exhaust gas discharged from the exhaust heat recovery boiler to the first evaporator; a second exhaust gas line (142) for guiding the exhaust gas discharged from the first evaporator to the water recovery device; a bypass exhaust gas line (143) connected to the first exhaust gas line and the second exhaust gas line so as to bypass the first evaporator; an exhaust gas damper (150) for changing the ratio of the flow rate of the exhaust gas flowing into the first evaporator to the flow rate of the exhaust gas flowing through the bypass exhaust gas line; Further provided are:

[0110] According to the configuration 2) above, it is possible to adjust the ratio between the flow rate of the exhaust gas flowing into the first evaporator and the flow rate of the exhaust gas flowing through the bypass exhaust gas line in accordance with fluctuations in the calorific value of the exhaust gas at the boiler outlet. Therefore, even if the load on the gas turbine fluctuates, the temperature of the exhaust gas at the exhaust gas inlet of the water recovery device can be stabilized. This prevents an increase in the circulating flow rate of the recovered water in the recovered water circulation line, thereby reducing the power consumption of the water recovery system and improving the power generation efficiency of the entire gas turbine cogeneration system. Furthermore, if an abnormality occurs in the first binary power generation system, the exhaust gas can be circulated through the water recovery device without flowing through the first and second exhaust gas lines. This allows inspection and repair of the first binary power generation system to be performed while the water recovery system continues to operate.

[0111] 3) In some embodiments, the water recovery system described in 2) above, a water recovery device exhaust gas inlet temperature sensor (92) for measuring the temperature of the exhaust gas flowing from a position (P1) where the second exhaust gas line is connected to the bypass exhaust gas line toward the water recovery device; a controller (90) for controlling the exhaust gas damper so that the temperature measured by the exhaust gas inlet temperature sensor of the water recovery device becomes a first specified temperature; Further provided are:

[0112] According to the configuration of 3) above, even if the load of the gas turbine fluctuates, the controller controls the exhaust gas damper to adjust the ratio between the flow rate of exhaust gas flowing into the first evaporator and the flow rate of exhaust gas flowing through the bypass exhaust gas line, thereby adjusting the temperature of the exhaust gas flowing into the water recovery device. This makes it possible to stabilize the temperature of the exhaust gas at the exhaust gas inlet of the water recovery device at approximately the first specified temperature, and to prevent an increase in the circulating flow rate of recovered water in the recovered water circulation line. This therefore reduces the power consumption of the water recovery system.

[0113] 4) In some embodiments, the water recovery system according to 2) or 3) above, The first binary power generation system includes: a first circulation line (119) for circulating the first circulation low-boiling-point working medium between the first evaporator and the first turbine; a first pump device (115) including a first circulation pump (115A) disposed in the first circulation line; further comprising The water recovery system comprises: a water recovery device exhaust gas inlet temperature sensor (92) for measuring the temperature of the exhaust gas flowing from a position (P1) where the second exhaust gas line is connected to the bypass exhaust gas line toward the water recovery device; a controller (90) for controlling the flow rate of the first circulating low-boiling-point working medium discharged from the first pump device so that the temperature measured by the water recovery device exhaust gas inlet temperature sensor becomes a first specified temperature; Further provided are:

[0114] According to the configuration of 4) above, even if the load on the gas turbine fluctuates, the controller adjusts the temperature of the exhaust gas flowing through the second exhaust gas line by controlling the first pump device. This makes it possible to stabilize the temperature of the exhaust gas at the exhaust gas inlet of the water recovery device. Since it is possible to prevent an increase in the circulating flow rate of recovered water in the recovered water circulation line, it is possible to reduce the power consumption of the water recovery system.

[0115] 5) In some embodiments, the water recovery system according to any one of 1) to 4) above, The first circulating low boiling point working medium is R-245fa (HFC-245fa).

[0116] According to the configuration of 5) above, since the ozone depletion potential of R-245fa is zero and the global warming potential of R-245fa is relatively low, the water recovery system can reduce the adverse impact on the surrounding environment.

[0117] 6) In some embodiments, the water recovery system according to any one of 1) to 5) above, The recovered water cooling system includes: a second binary power generation system (220) including a second evaporator (221) for evaporating a second circulating low-boiling-point working medium, which is a second organic medium; a second turbine (222) configured to obtain rotational power from the evaporated second circulating low-boiling-point working medium; and a second generator (223) connected to the second turbine; the second evaporator is configured to evaporate the second circulating low-boiling point working medium using at least a portion of the recovered water flowing through the recovered water circulation line as a heat source, The recovered water cooler includes the second evaporator.

[0118] According to the configuration 6) above, the second binary power generation system generates power by utilizing the heat contained in the recovered water discharged from the water recovery device, thereby further improving the power generation efficiency of the entire gas turbine cogeneration system.

[0119] 7) In some embodiments, the water recovery system described in 6) above, The recovered water circulation line is a power generation recovered water supply line (61) for guiding the recovered water discharged from the water recovery device to the second evaporator; a power generation recovered water discharge line (62) for guiding the recovered water discharged from the second evaporator to the water recovery device; a recovered water bypass line (63) connected to the power generation recovered water supply line and the power generation recovered water discharge line so as to bypass the second evaporator; a recovered water flow control valve (65) for changing the ratio of the flow rate of the recovered water flowing into the second evaporator to the flow rate of the recovered water flowing through the recovered water bypass line; Further includes:

[0120] According to the configuration of 7) above, even if the temperature of the recovered water discharged from the water recovery device fluctuates, it is possible to change the ratio of the flow rate of the recovered water flowing into the second evaporator to the flow rate of the recovered water flowing through the recovered water bypass line. Therefore, even if the temperature of the recovered water discharged from the water recovery device fluctuates, the temperature of the refrigerant water flowing into the water recovery device can be stabilized. Therefore, it is possible to recover moisture from the exhaust gas in the water recovery device while maintaining the temperature of the exhaust gas discharged from the water recovery device at a desired temperature.

[0121] 8) In some embodiments, the water recovery system described in 7) above, a water recovery device inlet refrigerant water temperature sensor (93) for measuring the temperature of the recovered water flowing from a position (P2) in the recovered water circulation line where the power generation recovered water discharge line is connected to the recovered water bypass line toward the water recovery device; a controller (90) for controlling the recovered water flow adjustment valve so that the temperature measured by the water recovery device inlet refrigerant water temperature sensor becomes a second specified temperature; Further provided are:

[0122] According to the configuration of 8) above, even if the temperature of the recovered water discharged from the water recovery device fluctuates, the controller controls the recovered water flow control valve to adjust the ratio between the flow rate of the recovered water flowing into the second evaporator and the flow rate of the recovered water flowing through the recovered water bypass line, thereby adjusting the temperature of the recovered water flowing into the water recovery device. This makes it possible to stabilize the temperature of the refrigerant water at the inlet of the water recovery device at approximately the second specified temperature, and to set the temperature of the exhaust gas discharged from the water recovery device to a desired temperature.

[0123] 9) In some embodiments, the water recovery system according to 7) or 8) above, The recovered water cooler further includes an external water cooler (23) configured to cool the recovered water by heat exchange between external water and the recovered water, The recovered water flowing into the external water cooler includes the recovered water flowing into the second evaporator and the recovered water flowing through the recovered water bypass line.

[0124] According to the configuration of 9) above, the cooling function of the recovered water is performed by the second evaporator and the external water cooler, so that the cooling heat load of the second binary power generation system can be distributed. Furthermore, if an abnormality occurs in the second binary power generation system, the recovered water is not flowed to the second evaporator, and only the external water cooler can perform the cooling function of the recovered water. This allows inspection and repair of the second binary power generation system to be carried out while the water recovery system continues to operate.

[0125] 10) In some embodiments, the water recovery system according to any one of 7) to 9) above, The second binary power generation system includes: a second circulation line (229) for circulating the second circulation low-boiling point working medium between the second evaporator and the second turbine; a second pump device (225) including a second circulation pump (225A) disposed in the second circulation line; further comprising The water recovery system comprises: a water recovery device inlet refrigerant water temperature sensor (93) for measuring the temperature of the recovered water flowing from a position in the recovered water circulation line where the power generation recovered water discharge line is connected to the recovered water bypass line to the water recovery device; a controller (90) for controlling the second pump device so that the temperature measured by the water recovery device inlet refrigerant water temperature sensor becomes a second specified temperature; Further provided are:

[0126] According to the configuration of 10) above, even if the temperature of the recovered water discharged from the water recovery device fluctuates, the controller adjusts the temperature of the recovered water flowing through the recovered water discharge line by controlling the second pump device. This makes it possible to stabilize the temperature of the refrigerant water flowing into the water recovery device at the second specified temperature, and to make the temperature of the exhaust gas discharged from the water recovery device a desired temperature.

[0127] 11) In some embodiments, the water recovery system according to any one of 6) to 10) above, The second circulating low boiling point working medium is R-245fa (HFC-245fa).

[0128] According to the configuration of 11) above, since the ozone depletion potential of R-245fa is zero and the global warming potential of R-245fa is relatively low, the water recovery system can reduce the adverse impact on the surrounding environment.

[0129] 12) In some embodiments, the water recovery system according to any one of 1) to 11) above, The recovered water circulation line is a recovered water discharge line (39) for guiding the recovered water discharged from the water recovery device to the recovered water cooler; a recovered water supply line (42) for guiding the recovered water cooled by the recovered water cooler to the water recovery device as the refrigerant water; a high-temperature feedwater line (44) connected to the recovered water discharge line, for guiding the recovered water taken out from the recovered water discharge line to a make-up water tank that stores boiler feedwater to be supplied to the heat recovery boiler; a low-temperature water supply line (47) connected to the recovered water supply line for guiding the recovered water taken out from the recovered water supply line to the make-up water tank; a water treatment device (46) for treating the recovered water flowing through the low-temperature water supply line to remove impurities; Further provided are:

[0130] According to the configuration of 12) above, the high-temperature feedwater line guides recovered water that does not require impurity removal to the makeup water tank. Because this recovered water is high-temperature water that flows upstream of the recovered water cooler, a decrease in the temperature of the boiler feedwater stored in the makeup water tank can be suppressed. As a result, the amount of heat required for the heat recovery boiler to generate boiler steam can be reduced, improving the thermal efficiency of the gas turbine cogeneration system. On the other hand, the low-temperature feedwater line guides recovered water that requires impurity removal to the makeup water tank via the water treatment device. Because this recovered water is low-temperature water that flows downstream of the recovered water cooler, a decrease in the impurity removal function of the water treatment device can be suppressed. Therefore, even if the recovered water recovered in the water recovery device contains impurities, the recovered water can be supplied to the makeup water tank without being discarded. As a result, a water recovery system is realized that can reuse recovered water recovered from exhaust gas as boiler feedwater without waste and improves power generation efficiency.

[0131] 13) A method of operating a water recovery system (40) according to at least one embodiment of the present disclosure, comprising: a water recovery device (33) for recovering moisture from an exhaust gas (13) discharged from a heat recovery boiler (14) of a gas turbine cogeneration system (10) by heat exchange between the exhaust gas and refrigerant water; a recovered water cooling system (50) including a recovered water cooler (55) for cooling the recovered water containing moisture recovered by the water recovery device; a recovered water circulation line (43) for guiding the recovered water discharged from the water recovery device to the recovered water cooler and for guiding the recovered water cooled by the recovered water cooler to the water recovery device as the refrigerant water; a recovered water circulation pump (38) disposed in the recovered water circulation line; A method of operating a water recovery system comprising: The water recovery system comprises: a first binary power generation system (110) including a first evaporator (111) for evaporating a first circulating low-boiling-point working medium, which is a first organic medium; a first turbine (112) configured to obtain rotational power from the evaporated first circulating low-boiling-point working medium; and a first generator (113) connected to the first turbine; a first exhaust gas line (141) for guiding the exhaust gas discharged from the exhaust heat recovery boiler to the first evaporator; a second exhaust gas line (142) for guiding the exhaust gas discharged from the first evaporator to the water recovery device; a bypass exhaust gas line (143) connected to the first exhaust gas line and the second exhaust gas line so as to bypass the first evaporator and connected to the water recovery device; a combined exhaust gas line (143) connecting a connection point between the second exhaust gas line and the bypass exhaust gas line and the water recovery device; an exhaust gas damper (150) for changing the ratio of the flow rate of the exhaust gas flowing into the first evaporator to the flow rate of the exhaust gas flowing through the bypass exhaust gas line; a water recovery and exhaust system exhaust gas inlet temperature sensor (92) for measuring the temperature of the exhaust gas flowing in the bypass exhaust gas line downstream of a position (P1) where the second exhaust gas line is connected to the bypass exhaust gas line, The method for operating the water recovery system includes: The method includes an exhaust gas damper control step (S13) of controlling the exhaust gas damper so that the temperature measured by the exhaust gas inlet temperature sensor of the water recovery device becomes a first specified temperature.

[0132] According to the configuration 13) above, the same effects as those of 1) above can be obtained.

[0133] 14) A method for retrofitting a water recovery system according to at least one embodiment of the present disclosure, comprising: a water recovery device (33) for recovering moisture from an exhaust gas (13) discharged from a heat recovery boiler (14) of a gas turbine cogeneration system (10) by heat exchange between the exhaust gas and refrigerant water; a recovered water cooling system (50) including a recovered water cooler (55) for cooling the recovered water containing moisture recovered by the water recovery device; a recovered water circulation line (43) for guiding the recovered water discharged from the water recovery device to the recovered water cooler and for guiding the recovered water cooled by the recovered water cooler to the water recovery device as the refrigerant water; a recovered water circulation pump (38) disposed in the recovered water circulation line; A method for retrofitting a water recovery system comprising: a first binary power generation system addition step (S31) of additionally installing a first binary power generation system (110) including a first evaporator (111) for evaporating a first circulating low-boiling-point working medium, which is a first organic medium, a first turbine (112) configured to obtain rotational power from the evaporated first circulating low-boiling-point working medium, and a first generator (113) connected to the first turbine; an exhaust gas line additional step (S33) of additionally installing a first exhaust gas line (141) for guiding the exhaust gas discharged from the exhaust heat recovery boiler to the first evaporator and a second exhaust gas line (142) for guiding the exhaust gas discharged from the first evaporator to the water recovery device; A method for retrofitting a water recovery system further comprising:

[0134] According to the configuration 14) above, the same effects as those of the configuration 1) above can be obtained.

[0135] 15) A method for retrofitting a water recovery system according to at least one embodiment of the present disclosure, comprising: a water recovery device (33) for recovering moisture from an exhaust gas (13) discharged from a heat recovery boiler (14) of a gas turbine cogeneration system (10) by heat exchange between the exhaust gas and refrigerant water; a recovered water cooling system (50) including a recovered water cooler (55) for cooling the recovered water containing moisture recovered by the water recovery device; a recovered water circulation line (43) for guiding the recovered water discharged from the water recovery device to the recovered water cooler and for guiding the recovered water cooled by the recovered water cooler to the water recovery device as the refrigerant water; a recovered water circulation pump (38) disposed in the recovered water circulation line; a first binary power generation system (110) including a first evaporator (111) for evaporating a first circulating low-boiling-point working medium, which is a first organic medium; a first turbine (112) configured to obtain rotational power from the evaporated first circulating low-boiling-point working medium; and a first generator (113) connected to the first turbine; A method for modifying a water recovery system, wherein the first evaporator is configured to evaporate the first circulating low-boiling point working medium using at least a portion of the exhaust gas flowing from the heat recovery boiler toward the water recovery device as a heat source, a second binary power generation system addition step (S35) of additionally installing a second binary power generation system (220) including a second evaporator (221) for evaporating a second circulating low boiling point working medium, which is a second organic medium, a second turbine (222) configured to obtain rotational power from the evaporated second circulating low boiling point working medium, and a second generator (223) connected to the second turbine, wherein the second evaporator is configured to evaporate the second circulating low boiling point working medium using at least a part of the recovered water flowing through the recovered water circulation line as a heat source; a power generation recovered water line adding step (S37) of adding a power generation recovered water supply line (61) for guiding the recovered water discharged from the water recovery device to the second evaporator, and a power generation recovered water discharge line (62) for guiding the recovered water discharged from the second evaporator to the water recovery device; Equipped with.

[0136] According to the configuration 15) above, the same effects as those of 1) above can be obtained. [Explanation of symbols]

[0137] 2: Turbine 3: Combustor 5: Generator 9: Gas turbine 10: Cogeneration system 10: Gas turbine cogeneration system 13: Exhaust gas 14: Waste heat recovery boiler 15: Water supply line 17: Refill water tank 19: Water supply line 23: External water cooler 24: External water supply line 25: External water supply pump 26: Connection line 29: Exhaust line 30: Exhaust tower 31: Exhaust damper 33: Water recovery device 37: Water supply line 38: Recovered water circulation pump 39: Reclaimed water discharge line 40: Water recovery system 42: Reclaimed water supply line 43: Recycled water circulation line 44: High temperature water supply line 45: Low temperature water supply valve 46: Water treatment equipment 47: Low temperature water supply line 48: High temperature water supply valve 50: Recovered water cooling system 55: Recovered water cooler 57: Discharge line 61: Power generation recovered water supply line 62: Power generation recovered water discharge line 63: Reclaimed water bypass line 65: Recovered water flow control valve 67: Supply flow valve 68: Discharge flow control valve 69: Bypass flow control valve 90: Controller 92: Water recovery device exhaust gas inlet temperature sensor 93: Water recovery device inlet refrigerant water temperature sensor 99: Water recovery device exhaust gas outlet temperature sensor 110: First binary power generation system 111: First evaporator 112: First turbine 113: First generator 114: First condenser 115: First pump device 115A: First circulation pump 115B: 1st flow control valve 118: 1st cooling source 119: First circulation line 141: First exhaust gas line 142: Second exhaust gas line 143: Bypass exhaust gas line 144: Combined exhaust gas line 145: Exhaust gas supply line 146: Ion exchange resin 149: Exhaust gas supply line before modification 150: Exhaust gas damper 151: First exhaust gas damper 152: Second exhaust gas damper 153: Bypass exhaust gas damper 220: Second binary power generation system 221: Second evaporator 222: Second turbine 223: Second generator 224: Second condenser 225: Second pump unit 225A: Second circulation pump 225B: 2nd flow control valve 228:Second cooling source 229: Second circulation line 331: Exhaust gas inlet 332: Exhaust gas outlet 333: Refrigerant water inlet

Claims

1. a water recovery device for recovering moisture from exhaust gas discharged from a heat recovery boiler of a gas turbine cogeneration system by heat exchange between the exhaust gas and refrigerant water; a recovered water cooling system including a recovered water cooler for cooling the recovered water containing moisture recovered by the water recovery device; a recovered water circulation line for guiding the recovered water discharged from the water recovery device to the recovered water cooler and for guiding the recovered water cooled by the recovered water cooler to the water recovery device as the refrigerant water; a recovered water circulation pump disposed in the recovered water circulation line; A water recovery system comprising: a first binary power generation system including a first evaporator for evaporating a first circulating low boiling point working medium, which is a first organic medium; a first turbine configured to obtain rotational power from the evaporated first circulating low boiling point working medium; and a first generator connected to the first turbine; the first evaporator is configured to evaporate the first circulating low-boiling point working medium using at least a part of the exhaust gas flowing from the exhaust heat recovery boiler toward the water recovery device as a heat source, a first exhaust gas line for guiding the exhaust gas discharged from the heat recovery boiler to the first evaporator; a second exhaust gas line for guiding the exhaust gas discharged from the first evaporator to the water recovery device; a bypass exhaust gas line connected to the first exhaust gas line and the second exhaust gas line so as to bypass the first evaporator; an exhaust gas damper for changing a ratio of a flow rate of the exhaust gas flowing into the first evaporator to a flow rate of the exhaust gas flowing through the bypass exhaust gas line; Further equipped Collection system.

2. a water recovery device exhaust gas inlet temperature sensor for measuring the temperature of the exhaust gas flowing from a position where the second exhaust gas line is connected to the bypass exhaust gas line toward the water recovery device; a controller for controlling the exhaust gas damper so that the temperature measured by the water recovery device exhaust gas inlet temperature sensor becomes a first specified temperature; Further equipped The water recovery system of claim 1 .

3. The first binary power generation system includes: a first circulation line for circulating the first circulation low-boiling point working medium between the first evaporator and the first turbine; a first pump device including a first circulation pump disposed in the first circulation line; further comprising The water recovery system comprises: a water recovery device exhaust gas inlet temperature sensor for measuring the temperature of the exhaust gas flowing from a position where the second exhaust gas line is connected to the bypass exhaust gas line toward the water recovery device; a controller for controlling the flow rate of the first circulating low-boiling-point working medium discharged from the first pump device so that the temperature measured by the water recovery device exhaust gas inlet temperature sensor becomes a first specified temperature; Further equipped 3. The water recovery system according to claim 1 or 2.

4. The first circulating low boiling point working medium is R-245fa (HFC-245fa).

3. The water recovery system according to claim 1 or 2.

5. A water recovery device for recovering moisture from exhaust gas discharged from a heat recovery boiler of a gas turbine cogeneration system by heat exchange between the exhaust gas and refrigerant water; a recovered water cooling system including a recovered water cooler for cooling the recovered water containing moisture recovered by the water recovery device; a recovered water circulation line for guiding the recovered water discharged from the water recovery device to the recovered water cooler and for guiding the recovered water cooled by the recovered water cooler to the water recovery device as the refrigerant water; a recovered water circulation pump disposed in the recovered water circulation line; A water recovery system comprising: a first binary power generation system including a first evaporator for evaporating a first circulating low boiling point working medium, which is a first organic medium; a first turbine configured to obtain rotational power from the evaporated first circulating low boiling point working medium; and a first generator connected to the first turbine; the first evaporator is configured to evaporate the first circulating low-boiling point working medium using at least a part of the exhaust gas flowing from the exhaust heat recovery boiler toward the water recovery device as a heat source, The recovered water cooling system includes: a second binary power generation system including a second evaporator for evaporating a second circulating low boiling point working medium, which is a second organic medium; a second turbine configured to obtain rotational power from the evaporated second circulating low boiling point working medium; and a second generator connected to the second turbine; the second evaporator is configured to evaporate the second circulating low-boiling point working medium using at least a portion of the recovered water flowing through the recovered water circulation line as a heat source, the recovered water cooler has the second evaporator, The recovered water circulation line is a power generation recovered water supply line for guiding the recovered water discharged from the water recovery device to the second evaporator; a power generation recovered water discharge line for guiding the recovered water discharged from the second evaporator to the water recovery device; a recovered water bypass line connected to the power generation recovered water supply line and the power generation recovered water discharge line so as to bypass the second evaporator; a recovered water flow control valve for changing a ratio of a flow rate of the recovered water flowing into the second evaporator to a flow rate of the recovered water flowing through the recovered water bypass line; Also includes Water recovery system.

6. a water recovery device inlet refrigerant water temperature sensor for measuring the temperature of the recovered water flowing from a position in the recovered water circulation line where the power generation recovered water discharge line is connected to the recovered water bypass line toward the water recovery device; a controller for controlling the recovered water flow adjustment valve so that the temperature measured by the water recovery device inlet refrigerant water temperature sensor becomes a second specified temperature; Further equipped 6. The water recovery system of claim 5.

7. the recovered water cooler further includes an external water cooler configured to cool the recovered water by heat exchange between external water and the recovered water; The recovered water flowing into the external water cooler includes the recovered water flowing into the second evaporator and the recovered water flowing through the recovered water bypass line.

6. The water recovery system of claim 5.

8. The second binary power generation system includes: a second circulation line for circulating the second circulation low boiling point working medium between the second evaporator and the second turbine; a second pump device including a second circulation pump disposed in the second circulation line; further comprising The water recovery system comprises: a water recovery device inlet refrigerant water temperature sensor for measuring the temperature of the recovered water flowing from a position in the recovered water circulation line where the power generation recovered water discharge line is connected to the recovered water bypass line to the water recovery device; a controller for controlling the second pump device so that the temperature measured by the water recovery device inlet refrigerant water temperature sensor becomes a second specified temperature; Further equipped 6. The water recovery system of claim 5.

9. The second circulating low boiling point working medium is R-245fa (HFC-245fa).

6. The water recovery system of claim 5.

10. A water recovery device for recovering moisture from exhaust gas discharged from a heat recovery boiler of a gas turbine cogeneration system by heat exchange between the exhaust gas and refrigerant water; a recovered water cooling system including a recovered water cooler for cooling the recovered water containing moisture recovered by the water recovery device; a recovered water circulation line for guiding the recovered water discharged from the water recovery device to the recovered water cooler and for guiding the recovered water cooled by the recovered water cooler to the water recovery device as the refrigerant water; a recovered water circulation pump disposed in the recovered water circulation line; A water recovery system comprising: a first binary power generation system including a first evaporator for evaporating a first circulating low boiling point working medium, which is a first organic medium; a first turbine configured to obtain rotational power from the evaporated first circulating low boiling point working medium; and a first generator connected to the first turbine; the first evaporator is configured to evaporate the first circulating low-boiling point working medium using at least a part of the exhaust gas flowing from the exhaust heat recovery boiler toward the water recovery device as a heat source, The recovered water circulation line is a recovered water discharge line for guiding the recovered water discharged from the water recovery device to the recovered water cooler; a recovered water supply line for guiding the recovered water cooled by the recovered water cooler to the water recovery device as the refrigerant water; a high-temperature feedwater line connected to the recovered water discharge line, for guiding the recovered water taken out from the recovered water discharge line to a make-up water tank that stores boiler feedwater to be supplied to the heat recovery boiler; a low-temperature water supply line connected to the recovered water supply line for guiding the recovered water taken out from the recovered water supply line to the make-up water tank; a water treatment device for treating the recovered water flowing through the low-temperature water supply line to remove impurities; Further equipped Water recovery system.

11. a water recovery device for recovering moisture from exhaust gas discharged from a heat recovery boiler of a gas turbine cogeneration system by heat exchange between the exhaust gas and refrigerant water; a recovered water cooling system including a recovered water cooler for cooling the recovered water containing moisture recovered by the water recovery device; a recovered water circulation line for guiding the recovered water discharged from the water recovery device to the recovered water cooler and for guiding the recovered water cooled by the recovered water cooler to the water recovery device as the refrigerant water; a recovered water circulation pump disposed in the recovered water circulation line; A method of operating a water recovery system comprising: The water recovery system comprises: a first binary power generation system including a first evaporator for evaporating a first circulating low boiling point working medium, which is a first organic medium; a first turbine configured to obtain rotational power from the evaporated first circulating low boiling point working medium; and a first generator connected to the first turbine; a first exhaust gas line for guiding the exhaust gas discharged from the heat recovery boiler to the first evaporator; a second exhaust gas line for guiding the exhaust gas discharged from the first evaporator to the water recovery device; a bypass exhaust gas line connected to the first exhaust gas line and the second exhaust gas line so as to bypass the first evaporator, and connected to the water recovery device; a combined exhaust gas line connecting a connection point between the second exhaust gas line and the bypass exhaust gas line and the water recovery device; an exhaust gas damper for changing a ratio of a flow rate of the exhaust gas flowing into the first evaporator to a flow rate of the exhaust gas flowing through the bypass exhaust gas line; a water recovery device exhaust gas inlet temperature sensor for measuring the temperature of the exhaust gas flowing in the bypass exhaust gas line downstream of a position where the second exhaust gas line is connected to the bypass exhaust gas line, The method for operating the water recovery system includes: an exhaust gas damper control step of controlling the exhaust gas damper so that the temperature measured by the exhaust gas inlet temperature sensor of the water recovery device becomes a first specified temperature; How to operate a water recovery system.

12. a water recovery device for recovering moisture from exhaust gas discharged from a heat recovery boiler of a gas turbine cogeneration system by heat exchange between the exhaust gas and refrigerant water; a recovered water cooling system including a recovered water cooler for cooling the recovered water containing moisture recovered by the water recovery device; a recovered water circulation line for guiding the recovered water discharged from the water recovery device to the recovered water cooler and for guiding the recovered water cooled by the recovered water cooler to the water recovery device as the refrigerant water; a recovered water circulation pump disposed in the recovered water circulation line; A method for retrofitting a water recovery system comprising: a first binary power generation system additional installation step of additionally installing a first binary power generation system including a first evaporator for evaporating a first circulating low boiling point working medium which is a first organic medium, a first turbine configured to obtain rotational power from the evaporated first circulating low boiling point working medium, and a first generator connected to the first turbine; an exhaust gas line adding step of adding a first exhaust gas line for guiding the exhaust gas discharged from the exhaust heat recovery boiler to the first evaporator, a second exhaust gas line for guiding the exhaust gas discharged from the first evaporator to the water recovery device, a bypass exhaust gas line connected to the first exhaust gas line and the second exhaust gas line so as to bypass the first evaporator, and an exhaust gas damper for changing the ratio of the flow rate of the exhaust gas flowing into the first evaporator and the flow rate of the exhaust gas flowing through the bypass exhaust gas line; A method for retrofitting a water recovery system comprising:

13. a water recovery device for recovering moisture from exhaust gas discharged from a heat recovery boiler of a gas turbine cogeneration system by heat exchange between the exhaust gas and refrigerant water; a recovered water cooling system including a recovered water cooler for cooling the recovered water containing moisture recovered by the water recovery device; a recovered water circulation line for guiding the recovered water discharged from the water recovery device to the recovered water cooler and for guiding the recovered water cooled by the recovered water cooler to the water recovery device as the refrigerant water; a recovered water circulation pump disposed in the recovered water circulation line; a first binary power generation system including a first evaporator for evaporating a first circulating low boiling point working medium which is a first organic medium, a first turbine configured to obtain rotational power from the evaporated first circulating low boiling point working medium, and a first generator connected to the first turbine; A method for modifying a water recovery system, wherein the first evaporator is configured to evaporate the first circulating low-boiling-point working medium using at least a portion of the exhaust gas flowing from the exhaust heat recovery boiler toward the water recovery device as a heat source, a second binary power generation system additional installation step of additionally installing a second binary power generation system having a second evaporator for evaporating a second circulating low boiling point working medium which is a second organic medium, a second turbine configured to obtain rotational power from the evaporated second circulating low boiling point working medium, and a second generator connected to the second turbine, wherein the second evaporator is configured to evaporate the second circulating low boiling point working medium using at least a portion of the recovered water flowing through the recovered water circulation line as a heat source; a power generation recovered water line adding step of adding a power generation recovered water supply line for guiding the recovered water discharged from the water recovery device to the second evaporator, a power generation recovered water discharge line for guiding the recovered water discharged from the second evaporator to the water recovery device, a power generation recovered water bypass line connecting the power generation recovered water supply line and the power generation recovered water discharge line so as to bypass the second evaporator, and a recovered water flow adjustment valve for changing the ratio of the flow rate of the recovered water flowing into the second evaporator and the flow rate of the recovered water flowing through the recovered water bypass line; A method for retrofitting a water recovery system comprising:

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