Cold ORC power generator and control method of the same and organic fluid filling method of cold ORC power generator

Abstract

To provide a cold ORC power generator which enables downsizing and can be operated economically.SOLUTION: A cold ORC power generator 1 includes: a condenser 3 which causes propane and a cold source having a temperature of 0°C or lower to exchange heat to condense propane; a circulation pump 5 which transports liquefied propane; an outlet valve 7 which is provided at the outlet side of the circulation pump 5 and controls a flow rate of propane; an evaporator 9 which causes propane guided by the outlet valve 7 and sea water to exchange heat to evaporate propane; a turbine 11 which is operated by propane guided from the evaporator 9; a turbine flow regulating valve 31 which adjusts a flow rate of propane flowing into the turbine 11; and a power generator which is driven by the turbine 11 to generate electric power. The condenser 3 and the evaporator 9 are plate type heat exchangers stored in pressure containers. The cold ORC power generator 1 includes a control unit for controlling the turbine flow regulating valve 31 based on a heat exchange amount of the condenser 3.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to a cold ORC power generation device that uses a cold heat source of, for example, 0°C or less, a control method thereof, and a method for filling an organic fluid into a cold ORC power generation device. [Background technology]

[0002] A cold ORC (Organic Rankine Cycle) power generation system that uses a cold heat source of 0°C or less, such as LNG (liquefied natural gas), is known (see, for example, Patent Document 1). Such a cold ORC power generation system uses an organic fluid, such as propane, as the working fluid for the Rankine cycle. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2017-180323 Summary of the Invention [Problem to be solved by the invention]

[0004] ORC power generation systems typically use shell-and-tube heat exchangers for the condenser and evaporator. Shell-and-tube heat exchangers have a large shell capacity for storing condensate, making them difficult to miniaturize. Furthermore, the supply gas pressure of LNG and other cold energy sources tends to be high, at several MPa, making it difficult to realize an economical cold-energy ORC power generation system. For example, when NG (natural gas) vaporized from LNG in the condenser of an ORC power generation system is supplied to the boiler burner, it is possible to recover energy using a pressure-reducing expansion turbine before supplying the NG to the burner. However, if the NG supply destination requires high pressure, such as a gas turbine combustor, it is not possible to install a pressure-recovery expansion turbine, which reduces economic viability.

[0005] The present disclosure has been made in consideration of these circumstances, and aims to provide a cold ORC power generation system that can be miniaturized and operated economically, a control method therefor, and a method for filling an organic fluid into a cold ORC power generation system. [Means for solving the problem]

[0006] A cold-heat ORC power generation system according to one embodiment of the present disclosure comprises a condenser that condenses an organic fluid by heat exchange with a cold heat source, a liquid pump that transports the organic fluid condensed in the condenser, a liquid pump outlet valve provided on the outlet side of the liquid pump to control the flow rate of the organic fluid, an evaporator that evaporates the organic fluid guided from the liquid pump outlet valve by heat exchange with a hot heat source, a turbine that operates using the organic fluid guided from the evaporator, a turbine flow control valve that adjusts the flow rate of the organic fluid flowing into the turbine, and a generator that generates electricity using the turbine, wherein the condenser and the evaporator are plate-type heat exchangers housed inside a pressure vessel, and the system comprises a control unit that controls the turbine flow control valve based on the heat exchange rate of the condenser.

[0007] A control method for a cold-heat ORC power generation system according to one embodiment of the present disclosure is a control method for a cold-heat ORC power generation system including a condenser that condenses an organic fluid by heat exchange with a cold heat source, a liquid pump that transports the organic fluid condensed in the condenser, a liquid pump outlet valve provided on the outlet side of the liquid pump and controlling the flow rate of the organic fluid, an evaporator that evaporates the organic fluid guided from the liquid pump outlet valve by heat exchange with a hot heat source, a turbine that operates using the organic fluid guided from the evaporator, a turbine flow control valve that adjusts the flow rate of the organic fluid flowing into the turbine, and a generator that generates electricity using the turbine, wherein the condenser and the evaporator are plate-type heat exchangers housed inside a pressure vessel, and the turbine flow control valve is controlled based on the heat exchange rate of the condenser.

[0008] An organic fluid filling method for a cold-heat ORC power generation system according to one embodiment of the present disclosure is a method for filling an organic fluid into any of the cold-heat ORC power generation systems described above, and includes the steps of: evacuating an organic fluid circulation system, through which the organic fluid circulates, including the condenser, the expansion valve, the evaporator, and the turbine, to a pressure equal to or lower than the saturation pressure of water at 0°C; and, after the evacuation step, filling the organic fluid into the organic fluid circulation system. [Effects of the Invention]

[0009] It can be made smaller and is therefore more economical to operate. [Brief explanation of the drawings]

[0010] [Figure 1] 1 is a schematic configuration diagram showing a cold ORC power generation device according to a first embodiment of the present disclosure. [Figure 2] FIG. 4 is a schematic configuration diagram showing a cold ORC power generation device according to a second embodiment of the present disclosure. DETAILED DESCRIPTION OF THE INVENTION

[0011] [First embodiment] A first embodiment according to the present disclosure will be described below with reference to FIG. 1 shows a cold ORC (Organic Rankine Cycle) power generation system 1 according to this embodiment. The cold ORC power generation system 1 uses LNG (Liquefied Natural Gas), which is a cold medium below 0°C, as a cold source. In addition to LNG, other cold mediums that can be used below 0°C include LPG (Liquefied Petroleum Gas) and liquefied ammonia.

[0012] The cold ORC power generation system 1 of this embodiment uses propane (organic fluid) as the working fluid. However, other organic fluids may be used as the working fluid, such as low molecular weight hydrocarbons such as isopentane and butane, or R134a and R245fa, which are used as refrigerants for air conditioners.

[0013] The cold ORC power generation system 1 includes a condenser 3, a circulation pump (liquid pump) 5, an outlet valve (liquid pump outlet valve) 7, an evaporator 9, and a turbine 11. The condenser 3, circulation pump 5, outlet valve 7, evaporator 9, and turbine 11 are connected to a circulation path (organic fluid circulation system) 13 through which propane, which is a working fluid, circulates. The charging pressure of propane into the circulation path 13 is, for example, about 0.1 to 0.5 MPa.

[0014] The condenser 3 exchanges heat between LNG supplied through an LNG supply valve 15 and propane supplied from the turbine 11 via a circulation path 13. In the condenser 3, the LNG removes heat of condensation from the propane, condensing and liquefying the propane. The LNG is supplied to the condenser 3 at a pressure of, for example, several MPa.

[0015] The condenser 3 is a plate heat exchanger housed inside a pressure vessel. A plate heat exchanger is made up of multiple stacked plates, e.g., disc-shaped plates, each with a flow path formed by press molding, and unlike a shell-and-tube heat exchanger, does not have a volume for storing liquefied fluid. This makes it more compact than a shell-and-tube heat exchanger, i.e., it has a larger heat transfer area per unit volume of equipment. The condenser 3 is constructed by housing the entire plate heat exchanger inside a vessel, e.g., a cylindrical vessel.

[0016] The LNG heated by absorbing heat from the propane in the condenser 3 is heated to a predetermined temperature with seawater by the trim heater 17, and then led to a supply destination as vaporized NG (natural gas).

[0017] The propane condensed and liquefied in the condenser 3 is led to the drain tank 19. The drain tank 19 is a sealed container with a predetermined volume. A predetermined amount of liquefied propane is temporarily stored in the drain tank 19. Vaporized propane exists as a gas phase above the drain tank 19. The liquefied propane stored in the drain tank 19 is partially vaporized by heat that inevitably enters from the outside, and remains in the gas phase of the drain tank 19.

[0018] A pressure sensor 21 that detects the pressure in the gas phase portion is provided at the top of the drain tank 19. The output of the pressure sensor 21 is sent to a control unit (not shown). One end of a balance pipe 23 is connected to the top of the drain tank 19. The other end of the balance pipe 23 is connected to the inlet side of the condenser 3, through which propane flows. The balance pipe 23 returns vaporized propane in the gas phase portion of the drain tank 19 to the inlet side of the condenser 3.

[0019] A circulation pump 5 is connected to the downstream side of the flow of liquefied propane in the drain tank 19. The circulation pump 5 supplies the liquefied propane temporarily stored in the drain tank 19 to the downstream side.

[0020] A mini-flow circulation flow path 27 equipped with a mini-flow valve 25 is provided downstream of the circulation pump 5. The mini-flow valve 25 is controlled by the control unit. The mini-flow circulation flow path 27 connects the outlet of the circulation pump 5 to the drain tank 19. By controlling the flow rate through the mini-flow circulation flow path 27, a minimum flow rate (mini-flow) through the circulation pump 5 is ensured. The flow rate of the circulation pump 5 is controlled by the outlet valve 7 and the mini-flow valve.

[0021] The outlet valve 7 is provided downstream of the circulation pump 5 and controls the flow rate of the working fluid (liquefied propane) supplied to the evaporator 9. The outlet valve 7 is controlled by a control unit (not shown).

[0022] The evaporator 9 is provided downstream of the outlet valve 7 and evaporates and gasifies the liquefied propane by exchanging heat with seawater (a hot heat source). The evaporator 9 is a plate heat exchanger housed inside a pressure vessel. A plate heat exchanger is made up of a stack of, for example, circular plates that are press-molded to form flow channels, and unlike a shell-and-tube heat exchanger, it does not have a volume for storing liquefied fluid. This gives it a more compact structure than a shell-and-tube heat exchanger. The evaporator 9 is constructed by housing the entire plate heat exchanger inside a container that is, for example, cylindrical.

[0023] A superheat sensor 29 is provided on the outlet side of the evaporator 9 to measure the degree of superheat of the vaporized propane. The output of the superheat sensor 29 is sent to the control unit. The superheat sensor 29 includes, for example, a temperature sensor and a pressure sensor. The control unit calculates the degree of superheat from the saturation temperature at the gas pressure measured by the pressure sensor and the gas temperature measured by the temperature sensor. The control unit controls the opening of the outlet valve 7 based on the degree of superheat measured using the superheat sensor 29.

[0024] A turbine flow rate control valve 31 is provided downstream of the superheat sensor 29. The turbine flow rate control valve 31 is controlled by the control unit based on the output of a pressure sensor 21 provided in the drain tank 19.

[0025] A turbine 11 is provided downstream of the turbine flow rate control valve 31 via a turbine inlet valve 33. In this embodiment, two turbines 11 are provided in parallel. Two turbines 11 may be provided in parallel as in this embodiment, but one turbine 11 may also be provided, or three or more turbines 11 may be provided in parallel. The turbine inlet valve 33 is controlled by a control unit.

[0026] The turbine 11 is rotated by a working fluid (vaporized propane) supplied via a turbine inlet valve 33. A generator (not shown) is connected to the turbine 11. The generator is driven by the rotational output of the turbine 11 to generate electricity.

[0027] A bypass path 35 is provided to bypass the turbine flow control valve 31, the turbine inlet valve 33, and the turbine 11. The bypass path 35 is provided with a bypass flow control valve 37. The bypass flow control valve 37 is controlled by the control unit based on the output of a pressure sensor 21 provided in the drain tank 19.

[0028] The control unit is composed of, for example, a CPU (Central Processing Unit), RAM (Random Access Memory), ROM (Read Only Memory), and computer-readable storage media. A series of processes for realizing various functions is stored in, for example, a storage medium in the form of a program. The CPU reads this program into RAM and executes information processing and arithmetic operations to realize various functions. The program may be pre-installed in a ROM or other storage medium, provided in a state stored in a computer-readable storage medium, or distributed via wired or wireless communication means. Examples of computer-readable storage media include magnetic disks, magneto-optical disks, CD-ROMs, DVD-ROMs, and semiconductor memories.

[0029] Next, the operation of the cold ORC power generation device 1 having the above configuration will be described.

[0030] Vaporized propane guided from the exhaust side of turbine 11 passes through circulation path 13 and is guided to condenser 3. In condenser 3, the vaporized propane is condensed and liquefied by the cold heat of the LNG. The propane liquefied in condenser 3 is guided to drain tank 19 and temporarily stored there. The vaporized propane in the gas phase in drain tank 19 is returned to the inlet side of condenser 3 via balance pipe 23 and is condensed again in condenser 3.

[0031] The liquefied propane stored in drain tank 19 is sucked out of drain tank 19 by the operation of circulation pump 5 and is led to outlet valve 7 via circulation pump 5. At outlet valve 7, the opening degree is controlled by the control unit so that a predetermined degree of superheat is maintained by superheat sensor 29.

[0032] The liquefied propane that leaves outlet valve 7 is led to evaporator 9, where it is evaporated by seawater to become vaporized propane. The flow rate of the vaporized propane that leaves evaporator 9 is adjusted by turbine flow control valve 31, and then it is led to turbine 11 via turbine inlet valve 33. Meanwhile, a portion of the vaporized propane bypasses turbine 11 via bypass flow control valve 37 and is led to condenser 3.

[0033] The opening degrees of the turbine flow control valve 31 and the bypass flow control valve 37 are controlled by the control unit based on the output of the pressure sensor 21 provided in the drain tank 19. Specifically, when the flow rate of LNG passing through the condenser 3 changes, the heat exchange amount in the condenser 3 changes, and so the amount of propane condensed changes. This change is more pronounced because a plate-type heat exchanger is used as the condenser 3 than in a shell-and-tube heat exchanger, which has a relatively large internal volume. Fluctuations in the amount of propane condensed appear as pressure fluctuations in the drain tank 19. The control unit controls the opening degree of the turbine flow control valve 31 so as to suppress these pressure fluctuations. After the turbine flow control valve 31 is controlled to be fully open, the bypass flow control valve 37, which was fully closed, is opened and controlled.

[0034] For example, when the flow rate of LNG increases, the amount of condensation in the condenser 3 increases, the liquid level in the drain tank rises, and the detected pressure of the pressure sensor 21 decreases. In this case, the opening of the turbine flow control valve 31 is increased to increase the flow rate of propane flowing from the turbine 11 to the condenser 3. After the turbine flow control valve 31 is fully opened, the bypass flow control valve 37 is changed from fully closed to open, and the opening is adjusted by the control unit.

[0035] When vaporized propane flows into the turbine 11 through the turbine inlet valve 33, the vaporized propane rotates the turbine 11. The rotational output of the turbine 11 drives a generator to generate electricity. The vaporized propane that has passed through the turbine 11 is led to the condenser 3 .

[0036] The above-described embodiment has the following advantages. Since the condenser 3 and the evaporator 9 are plate heat exchangers housed inside the pressure vessel, they can be made smaller than shell-and-tube heat exchangers.

[0037] While plate heat exchangers can be made compact, they have a smaller heat capacity than shell-and-tube heat exchangers because the volume for storing condensed liquid is smaller. This means that the internal pressure of the drain tank 19 changes quickly in response to fluctuations in the flow rate of the cold heat source (fluctuations in the heat exchange rate). Therefore, the control unit controls the turbine flow control valve 31 to adjust the amount of propane supplied from the turbine 11 to the condenser 3 based on the heat exchange rate of the condenser 3. This allows the amount of heat exchange rate of the condenser 3 to change even if fluctuations in the flow rate of the LNG, the cold heat source, change, and the organic Rankine cycle using propane can be stably and economically operated.

[0038] By providing a drain tank 19 that temporarily stores the liquefied propane condensed in the condenser 3, which is a plate-type heat exchanger, it is possible to alleviate fluctuations in the condensate condensed in the condenser 3. Furthermore, the turbine flow control valve 31 is controlled so that the internal pressure of the drain tank 19 becomes a predetermined value, thereby stabilizing the organic Rankine cycle.

[0039] A bypass path 35 is provided that bypasses the turbine flow rate control valve 31 and the turbine 11, and the bypass flow rate is adjusted by a bypass flow rate control valve 37. This makes it possible to further improve the ability to follow fluctuations in the flow rate of LNG, which is the cold heat source.

[0040] By providing a balance pipe 23 that connects the gas phase section of drain tank 19 with the inlet side of condenser 3, vaporized propane that has evaporated due to heat input to drain tank 19 is guided to the inlet side of condenser 3 and re-liquefied. This makes it possible to prevent excessive accumulation of vaporized propane in drain tank 19.

[0041] By controlling the outlet valve 7 so that the degree of superheat of the vaporized propane at the outlet of the evaporator 9 is at a predetermined value, evaporation in the evaporator 9 can be performed appropriately.

[0042] [Second embodiment] Next, a second embodiment of the present disclosure will be described with reference to Fig. 2. In this embodiment, an organic fluid filling method for filling the cold ORC power generation apparatus of the first embodiment described above with propane will be described.

[0043] As shown in Fig. 2, a vacuum path 40 is installed in the circulation path 13. In Fig. 2, the circulation path 13 through which vacuuming is performed is indicated by a thick line.

[0044] The evacuation path 40 is provided with an on-off valve 42. The evacuation path 40 is preferably connected so as to perform evacuation from the highest position in the circulation path 13. A vacuum pump (not shown) is connected downstream of the evacuation path 40.

[0045] During the evacuation process for evacuating the circulation path 13, the vacuum pump is started and the on-off valve 42 is opened. This creates a vacuum inside the circulation path 13. The target vacuum level is set to be equal to or lower than the saturated pressure of water at 0°C. When evacuation is not being performed, the on-off valve 42 is closed.

[0046] After the evacuation step, propane is filled into the circulation path 13 up to a predetermined pressure (filling step).

[0047] The above-described embodiment has the following advantages. Since heat exchange occurs with LNG at 0°C or below in the condenser 3, there is a risk that moisture remaining in the circulation path 13 will freeze and reduce the heat exchange efficiency. Therefore, the moisture in the circulation path 13 is removed by evacuating the path to a pressure below the saturation pressure of water at 0°C.

[0048] Between the evacuation step and the filling step, a step of filling the circulation path 13 with an inert gas such as nitrogen and a step of again evacuating the circulation path 13 to a pressure equal to or lower than the saturation pressure of water at 0°C may be performed. This allows further removal of moisture.

[0049] The cold ORC power generation system and the control method thereof, and the organic fluid filling method for the cold ORC power generation system described in the above-described respective embodiments can be understood, for example, as follows.

[0050] A cold-heat ORC power generation system (1) according to a first aspect of the present disclosure includes a condenser (3) that condenses an organic fluid (propane) by heat exchange with a cold heat source (LNG) below 0°C, a liquid pump (5) that transports the organic fluid condensed in the condenser, a liquid pump outlet valve (7) provided on the outlet side of the liquid pump to control the flow rate of the organic fluid, an evaporator (9) that evaporates the organic fluid guided from the liquid pump outlet valve by heat exchange with a hot heat source (seawater), a turbine (11) that operates using the organic fluid guided from the evaporator, a turbine flow control valve (31) that adjusts the flow rate of the organic fluid flowing into the turbine, and a generator that generates electricity by being driven by the turbine, wherein the condenser (3) and the evaporator (9) are plate-type heat exchangers housed inside a pressure vessel, and a control unit that controls the turbine flow control valve (31) based on the heat exchange amount of the condenser (3).

[0051] Since a plate-type heat exchanger housed inside the pressure vessel is used as the condenser and evaporator, it is possible to make the heat exchanger smaller than a shell-and-tube heat exchanger. While plate heat exchangers can be made smaller, they have a smaller heat capacity than shell-and-tube heat exchangers because the volume for storing condensed liquid is smaller. This means that they are subject to large changes in response to fluctuations in the flow rate of the cold heat source (fluctuations in the amount of heat exchanged). Therefore, by controlling the turbine flow control valve with the control unit, the amount of organic fluid supplied from the turbine to the condenser can be adjusted based on the amount of heat exchanged by the condenser. This allows the amount of heat exchanged by the condenser to be adjusted even if fluctuations in the flow rate of the cold heat source change, resulting in stable and economical operation of the Rankine cycle of the organic fluid.

[0052] A cold ORC power generation system (1) according to a second aspect of the present disclosure is the same as that of the first aspect, except that a drain tank (19) is provided for temporarily storing the organic fluid condensed in the condenser (3), and the control unit controls the turbine flow control valve (31) so that the internal pressure of the drain tank (19) becomes a predetermined value.

[0053] By providing a drain tank that temporarily stores the organic fluid condensed in the condenser, fluctuations in the condensate condensed in the condenser can be alleviated. In addition, by controlling the turbine flow control valve so that the internal pressure of the drain tank is maintained at a predetermined value, the organic Rankine cycle can be stabilized.

[0054] The cold ORC power generation system (1) according to a third aspect of the present disclosure is the same as that of the second aspect, except that a bypass path (35) bypassing the turbine flow control valve (31) and the turbine (11) is provided, and a bypass flow control valve (37) is provided in the bypass path (35), and the control unit controls the bypass flow control valve (37) so that the internal pressure of the drain tank (19) becomes a predetermined value.

[0055] A bypass flow control valve is provided to bypass the turbine and the turbine, and the bypass flow rate is adjusted by the bypass flow control valve. This further improves the ability to follow fluctuations in the flow rate of the cold heat source.

[0056] The cold ORC power generation system (1) according to a fourth aspect of the present disclosure is the second or third aspect, and is provided with a balance pipe (23) connecting the gas phase portion of the drain tank (19) and the inlet side of the condenser (3).

[0057] By providing a balance pipe connecting the gas phase of the drain tank with the inlet of the condenser, the organic fluid vapor evaporated by heat input to the drain tank is guided to the inlet of the condenser and re-liquefied, which prevents excessive accumulation of vaporized gas in the drain tank.

[0058] A cold ORC power generation system (1) according to a fifth aspect of the present disclosure is any one of the first to fourth aspects, wherein the control unit controls the liquid pump outlet valve (7) so that the degree of superheat of the organic fluid at the outlet of the evaporator (9) becomes a predetermined value.

[0059] By controlling the liquid pump outlet valve so that the degree of superheat of the organic fluid at the outlet of the evaporator is at a predetermined value, evaporation in the evaporator can be performed appropriately.

[0060] A control method for a cold-heat ORC power generation system (1) according to a first aspect of the present disclosure is a control method for a cold-heat ORC power generation system (1) including: a condenser (3) that condenses an organic fluid (propane) by heat exchange with a cold heat source (LNG) at 0°C or below; a liquid pump (5) that transports the organic fluid condensed in the condenser; a liquid pump outlet valve (7) provided on the outlet side of the liquid pump and controlling the flow rate of the organic fluid; an evaporator (9) that evaporates the organic fluid guided from the liquid pump outlet valve by heat exchange with a hot heat source (seawater); a turbine (11) that operates using the organic fluid guided from the evaporator; a turbine flow control valve (31) that adjusts the flow rate of the organic fluid flowing into the turbine; and a generator that is driven by the turbine to generate electricity. The condenser (3) and the evaporator (9) are plate-type heat exchangers housed inside a pressure vessel, and the turbine flow control valve (31) is controlled based on the heat exchange amount of the condenser (3).

[0061] The organic fluid filling method for a cold-heat ORC power generation system (1) according to a first aspect of the present disclosure is a method for filling an organic fluid into a cold-heat ORC power generation system (1) according to any of the above aspects, and includes a vacuum pumping process for vacuuming an organic fluid circulation system (13) through which the organic fluid circulates, the organic fluid circulation system (13) including the condenser (3), the liquid pump outlet valve (7), the evaporator (9), and the turbine (11), to a pressure equal to or lower than the saturation pressure of water at 0°C, and a filling process for filling the organic fluid into the organic fluid circulation system (13) after the vacuum pumping process.

[0062] Since heat is exchanged with a cold source below 0°C in the condenser, any moisture remaining in the organic fluid circulation system could freeze and reduce the heat exchange efficiency. Therefore, before the filling process of filling the organic fluid, the system was evacuated to a pressure below the saturation pressure of water at 0°C to remove the moisture from the organic fluid circulation system. Between the evacuation step and the filling step, a step of filling the organic fluid circulation system with an inert gas such as nitrogen and a step of again evacuating the organic fluid circulation system to a pressure equal to or lower than the saturation pressure of water at 0°C may be included, thereby enabling further removal of moisture. [Explanation of symbols]

[0063] 1 Cold ORC power generator 3. Condenser 5 Circulation pump (liquid pump) 7 Outlet valve (liquid pump outlet valve) 9. Evaporator 11 Turbine 13 Circulation route (organic fluid circulation system) 15 LNG supply valve 17 Trim heater 19 Drain tank 21 Pressure Sensor 23 Balance pipe 25 Miniflow Valve 27 Miniflow circulation channel 29 Superheat sensor 31 Turbine flow control valve 33 Turbine inlet valve 35 Bypass Route 37 Bypass flow control valve 40 Vacuum path 42 On-off valve

Claims

1. a condenser that condenses the organic fluid by heat exchange with a cold source; a liquid pump for transporting the organic fluid condensed in the condenser; a liquid pump outlet valve provided on the outlet side of the liquid pump to control the flow rate of the organic fluid; an evaporator that evaporates the organic fluid introduced from the liquid pump outlet valve by heat exchange with a heat source; a turbine operated by the organic fluid channeled from the evaporator; a turbine flow rate control valve for controlling the flow rate of the organic fluid flowing into the turbine; a generator driven by the turbine to generate electricity; Equipped with the condenser and the evaporator are plate-type heat exchangers housed inside a pressure vessel; A cold ORC power generation system including a control unit that controls the turbine flow rate control valve based on the heat exchange amount of the condenser.

2. a drain tank for temporarily storing the organic fluid condensed by the condenser is provided; The cold ORC power generation system according to claim 1 , wherein the control unit controls the turbine flow rate control valve so that the internal pressure of the drain tank becomes a predetermined value.

3. a bypass path that bypasses the turbine flow rate control valve and the turbine is provided; a bypass flow rate adjustment valve is provided in the bypass path, The cold ORC power generation system according to claim 2 , wherein the control unit controls the bypass flow rate adjustment valve so that the internal pressure of the drain tank becomes a predetermined value.

4. 3. The cold ORC power generation system according to claim 2, further comprising a balance pipe connecting the gas phase portion of the drain tank and the inlet side of the condenser.

5. The cold ORC power generation system according to claim 1 , wherein the control unit controls the liquid pump outlet valve so that the degree of superheat of the organic fluid at the outlet of the evaporator becomes a predetermined value.

6. a condenser that condenses the organic fluid by heat exchange with a cold source of 0°C or less; a liquid pump for transporting the organic fluid condensed in the condenser; a liquid pump outlet valve provided on the outlet side of the liquid pump to control the flow rate of the organic fluid; an evaporator that evaporates the organic fluid introduced from the liquid pump outlet valve by heat exchange with a heat source; a turbine operated by the organic fluid channeled from the evaporator; a turbine flow rate control valve for controlling the flow rate of the organic fluid flowing into the turbine; a generator driven by the turbine to generate electricity; A method for controlling a cold ORC power generation system comprising: the condenser and the evaporator are plate-type heat exchangers housed inside a pressure vessel; A method for controlling a cold ORC power generation system, the method comprising controlling the turbine flow control valve based on the heat exchange amount of the condenser.

7. 6. A method for filling an organic fluid into a cold ORC power generation system according to claim 1, comprising: an evacuation step of evacuating an organic fluid circulation system, in which an organic fluid circulates, including the condenser, the liquid pump outlet valve, the evaporator, and the turbine, to a pressure equal to or lower than the saturation pressure of water at 0°C; a filling step of filling the organic fluid circulation system with an organic fluid after the evacuation step; A method for filling an organic fluid into a cold ORC power generation system.

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