JP2021055568A - Power generation device and method of controlling power generation device - Google Patents

Abstract

To provide a power generation technique that achieves generation of a large amount of power without excessively increasing the pressure in a pipe.SOLUTION: The present application discloses a power generation device that includes: a heat recovery unit that circulates a working medium sent out from a medium pump through an evaporator, an expander, and a condenser in this order and thereafter returns the working medium to the medium pump to recover heat of a heating medium supplied to an evaporator; a generator driven by the expander; a determination processing unit that executes upper limit determination processing of determining whether or not the pressure inside a pipe of a pipeline connecting the evaporator and the expander exceeds a predetermined upper limit threshold value, and overheating determination processing of determining whether or not a degree of overheating of the working medium in the pipeline is within a predetermined control target range; and an inflow control unit that controls an amount of the working medium flowing into the evaporator based on a result of the determination processing by the determination processing unit.SELECTED DRAWING: Figure 1

Description

The present invention relates to a power generation device and a method for controlling the power generation device.

A power generation device has been developed in which a working medium vaporized by heat exchange with a heating medium in an evaporator is supplied to an expander connected to a generator, and the expanding action of the working medium is used to drive the expander and the generator. (See Patent Document 1). In addition to the evaporator, the generator, and the expander, the power generation device includes a condenser that condenses the working medium expanded by the expander, and a medium pump that sends the condensed working medium to the evaporator. The amount of inflow of the working medium from the medium pump to the evaporator is adjusted so that the degree of superheat of the working medium supplied from the evaporator to the expander approaches a predetermined target value.

Japanese Unexamined Patent Publication No. 2014-47632

When the temperature of the heating medium is high, the degree of superheat of the working medium increases, which may exceed the target value. At this time, in order to reduce the degree of superheat, the inflow amount of the working medium into the evaporator is increased. As the inflow of the working medium into the evaporator increases, so does the amount of working medium that evaporates under heat exchange with the hot heating medium. As a result of the increase in the amount of evaporation of the working medium, the pressure inside the conduit that guides the working medium from the evaporator to the expander increases. If the inflow to the evaporator is increased while the pressure in the pipe has already reached a high value, the pressure in the pipe becomes excessively high.

An object of the present invention is to provide a power generation technique that achieves a high amount of power generation without excessively increasing the pressure in the pipe.

The power generation device according to one aspect of the present invention evaporates by circulating the working medium sent out by the medium pump so as to return to the medium pump after passing through the evaporator, the expander and the condenser in this order. The pressure inside the pipe connecting the heat recovery unit for recovering the heat of the heating medium supplied to the vessel, the generator driven by the expander, and the evaporator and the expander exceeds a predetermined upper limit threshold. A determination processing unit that executes an upper limit determination process for determining whether or not the condition is met, and an overheat degree determination process for determining whether or not the degree of superheat of the operating medium in the pipeline is within a predetermined control target range. And an inflow control unit that controls the inflow amount of the working medium into the evaporator based on the result of the determination process of the determination processing unit. When the determination result that the pressure in the pipe is equal to or lower than the upper limit threshold value is obtained in the upper limit determination process, the inflow control unit determines the superheat degree based on the determination result of the superheat degree determination process. The inflow amount is controlled so as to fall within the control target range. When the determination result that the pipe pressure exceeds the upper limit threshold value is obtained in the upper limit determination process, the inflow control unit sets the inflow amount so that the pipe pressure becomes equal to or less than the upper limit threshold value. After reducing the amount, the inflow amount is controlled so that the superheat degree falls within the control target range based on the determination result of the superheat degree determination process.

According to the above configuration, when the determination result that the in-pipe pressure exceeds the upper limit threshold value is obtained, the inflow control unit performs the inflow amount of the working medium into the evaporator so that the in-pipe pressure becomes equal to or less than the upper limit threshold value. To reduce. Therefore, the pressure in the pipe does not become excessively high.

The inflow amount is controlled based on the determination result of the superheat degree determination process under the condition that the pressure in the pipe is equal to or less than the upper limit threshold value. Therefore, even if the inflow amount is increased as a result of controlling the inflow amount based on the determination result of the superheat degree determination process, the pipe pressure only increases at a value equal to or less than the upper limit threshold value, and it is difficult to take an excessively large value. Therefore, the inflow amount can be increased and the evaporation amount of the working medium in the evaporator can be increased without excessively increasing the pressure in the pipe. As a result of the increase in the amount of evaporation of the working medium, the amount of power generated by the generator increases. That is, a high amount of power generation can be obtained without excessively increasing the pressure in the pipe.

The superheat degree determination process is performed after the upper limit determination process. If the inflow amount control based on the superheat degree determination process is performed before the upper limit determination process, the inflow amount control based on the superheat degree determination process may be performed under a state where the pipe pressure is already high. .. When the determination result that the superheat degree exceeds the upper limit of the control target range is obtained in the superheat degree determination process, the inflow amount of the working medium into the evaporator is increased in order to keep the superheat degree within the control target range. .. In this case, it is expected that the pressure inside the pipe will increase further and take an excessively high value. On the other hand, if the upper limit determination process is performed before the superheat degree determination process, the superheat degree is adjusted after setting the in-pipe pressure to the upper limit threshold value or less, so that the in-pipe pressure takes an excessively large value as described above. Is prevented.

With respect to the above configuration, the determination processing unit may further execute a lower limit determination process for determining whether or not the pressure in the pipe is below a predetermined lower limit threshold value. When the pressure in the pipe is within the pressure range determined by the lower limit threshold value and the upper limit threshold value, the inflow control unit sets the superheat degree to the control target based on the determination result of the superheat degree determination process. The inflow amount may be controlled so as to fall within the range. When the pressure inside the pipe is outside the pressure range, the inflow control unit adjusts the inflow amount so that the pressure inside the pipe falls within the pressure range, and then the determination result of the superheat degree determination process. The inflow amount may be controlled so that the degree of superheat falls within the control target range.

According to the above configuration, when the pressure in the pipe is outside the pressure range defined by the lower limit threshold value and the upper limit threshold value, the inflow control unit adjusts the inflow amount so that the pressure in the pipe is within the pressure range. Therefore, the pressure in the pipe does not take an excessively high value or an excessively low value. When the in-pipe pressure is lower than the lower threshold, the inflow control unit increases the inflow of the working medium into the evaporator in order to keep the in-pipe pressure within the pressure range. As a result, the power output from the generator driven by the expander also increases.

The control of the inflow amount based on the determination result in the superheat degree determination process is performed when the pressure in the pipe is within the pressure range. That is, when the inflow amount is controlled based on the determination result in the superheat degree determination process, the pressure inside the pipe exceeds the lower limit threshold value. Even if the inflow amount is reduced as a result of controlling the inflow amount based on the determination result in the superheat degree determination process, the pipe pressure is only reduced from the value equal to or higher than the lower limit threshold value, and it is difficult to take an excessively small value. Therefore, the driving force of the expander is maintained above a certain level, and the amount of power generated from the generator driven by the expander is also maintained above a certain level.

With respect to the above configuration, the determination processing unit may further execute a rotation speed determination process for determining whether or not the rotation speed of the medium pump exceeds a predetermined rotation speed threshold value. In the upper limit determination process, a determination result that the pressure in the pipe is equal to or lower than the upper limit threshold value is obtained, and in the rotation speed determination process, the rotation speed of the medium pump is equal to or less than the rotation speed threshold value. When the determination result is obtained, the inflow control unit may control the inflow amount so that the superheat degree falls within the control target range based on the determination result of the superheat degree determination process. When the determination result that the rotation speed of the medium pump exceeds the rotation speed threshold is obtained in the rotation speed determination process, the inflow control unit rotates the rotation speed of the medium pump. The inflow may be reduced by reducing the value to a value equal to or less than a few thresholds.

Even if the judgment result that the pressure inside the pipe is equal to or less than the upper limit threshold value is obtained in the upper limit judgment process, the pressure inside the pipe may subsequently take an excessively high value if the rotation speed of the medium pump continues to be high. .. According to the above configuration, when the determination result that the rotation speed of the medium pump exceeds the rotation speed threshold is obtained in the rotation speed determination process, the inflow control unit sets the rotation speed of the medium pump to the rotation speed. Reduce to a value below the threshold. As a result, it is possible to prevent the pressure inside the pipe from taking an excessively high value.

The power generation device according to another aspect of the present invention evaporates the working medium delivered by the medium pump by passing the working medium through the evaporator, the expander, and the condenser in this order and then circulating the working medium so as to return to the medium pump. A heat recovery unit that recovers the heat of the heating medium supplied to the vessel, a generator driven by the expander, and a heating medium that exchanges heat with the working medium by the evaporator to evaporate the working medium. When the temperature determination process for determining whether or not the temperature exceeds a predetermined temperature threshold and the determination result that the temperature of the heating medium exceeds the temperature threshold are obtained in the temperature determination process. A superheat degree determination process for raising the control target range of the superheat degree of the working medium in the pipeline connecting the evaporator and the expander to determine whether or not the superheat degree is within the control target range. The amount of inflow of the working medium into the evaporator is controlled so that the superheating degree of the working medium falls within the control target range based on the determination processing unit for executing the above and the result of the superheat degree determination processing. It is equipped with an inflow control unit.

According to the above configuration, when the determination result that the temperature of the heating medium exceeds the temperature threshold value is obtained in the temperature determination process, the control target range for the degree of superheat of the working medium is raised. When the upper limit has a high value, the degree of superheat is less likely to exceed the upper limit. That is, it becomes difficult to control to increase the inflow amount when the degree of superheat exceeds the upper limit. On the other hand, when the lower limit has a high value, the degree of superheat tends to fall below the lower limit. That is, it becomes easier to control to reduce the inflow amount when the degree of superheat falls below. Therefore, when the determination result that the temperature of the heating medium exceeds the temperature threshold value is obtained, the increase in the inflow amount of the working medium into the evaporator is suppressed.

The setting of the control target range described above is useful when the temperature of the heating medium changes significantly. The higher the temperature of the heating medium, the greater the amount of evaporation of the working medium in the evaporator, and the higher the pressure inside the pipeline connecting the evaporator and the expander. However, when the temperature of the heating medium exceeds the temperature threshold, the increase in the inflow amount is suppressed as described above, so that the increase in the evaporation amount of the working medium in the evaporator is also suppressed. Therefore, the pressure inside the pipe is unlikely to become excessively high.

The power generation device according to another aspect of the present invention evaporates the working medium delivered by the medium pump by passing the working medium through the evaporator, the expander, and the condenser in this order and then circulating the working medium so as to return to the medium pump. A heat recovery unit that recovers the heat of the heating medium supplied to the vessel, a generator driven by the expander, and a heating medium that exchanges heat with the working medium by the evaporator to evaporate the working medium. When the temperature determination process for determining whether or not the temperature exceeds a predetermined temperature threshold and the determination result that the temperature of the heating medium is equal to or lower than the temperature threshold are obtained in the temperature determination process, the said. It is determined whether or not the degree of superheat of the working medium in the conduit connecting the evaporator and the expander is within the first control target range of the degree of superheat, and the temperature of the heating medium sets the temperature threshold. When the determination result that the temperature is exceeded is obtained, the determination to execute the overheating degree determination process for determining whether or not the overheating degree is within the second control target range higher than the first control target range. When the determination result that the temperature of the processing unit and the heating medium is equal to or lower than the temperature threshold is obtained, the degree of superheat falls within the first control target range based on the result of the degree of superheat determination processing. The inflow amount of the working medium into the evaporator is controlled so as to be settled, and when the determination result that the temperature of the heating medium exceeds the temperature threshold is obtained, the degree of superheat is said to be the first. 2 It is provided with an inflow control unit that controls the inflow amount so as to fall within the control target range.

In the control method according to still another aspect of the present invention, the working medium delivered by the medium pump is circulated so as to be returned to the medium pump after passing through the evaporator, the expander and the condenser in this order, and the expansion is performed. It can be used to control a power generator that drives a generator using a machine. The control method is to execute an upper limit determination process for determining whether or not the pressure inside the pipe connecting the evaporator and the expander exceeds a predetermined upper limit threshold value, and in the upper limit determination process, the inside of the pipe. When the determination result that the pressure is equal to or lower than the upper limit threshold value is obtained, the working medium is placed on the evaporator so that the degree of superheat of the working medium in the pipeline falls within a predetermined control target range. When the inflow amount is controlled and the determination result that the pipe pressure exceeds the upper limit threshold value is obtained in the upper limit determination process, the inflow is such that the pipe pressure becomes equal to or less than the upper limit threshold value. After reducing the amount, the inflow amount is controlled so that the degree of superheat falls within the control target range.

In the control method according to still another aspect of the present invention, the working medium delivered by the medium pump is circulated so as to be returned to the medium pump after passing through the evaporator, the expander and the condenser in this order, and the expansion is performed. It can be used to control a power generator that drives a generator using a machine. The control method is to execute a temperature determination process of exchanging heat with the working medium in the evaporator and determining whether or not the temperature of the heating medium for evaporating the working medium exceeds a predetermined temperature threshold. When the determination result that the temperature of the heating medium exceeds the temperature threshold is obtained in the temperature determination process, the degree of superheat of the working medium in the conduit connecting the evaporator and the expander is obtained. The control target range is raised to execute a superheat degree determination process for determining whether or not the superheat degree is within the control target range, and based on the result of the superheat degree determination process, the operating medium is said to be said. It includes controlling the inflow amount of the working medium into the evaporator so that the degree of superheat falls within the control target range.

The above-mentioned power generation technology can achieve a high amount of power generation without excessively increasing the pressure in the pipe.

It is the schematic of the power generation apparatus of 1st Embodiment. It is a schematic flowchart which shows the exemplary operation of the determination processing part and the inflow control part of a power generation apparatus. It is a schematic flowchart which shows the other exemplary operation of a determination processing part and an inflow control part. It is the schematic of the power generation apparatus which performs the rotation speed determination processing. It is a schematic flowchart which shows the exemplary operation of the determination processing part which performs the rotation speed determination process. It is the schematic of the power generation apparatus of 2nd Embodiment. It is a conceptual graph of the judgment standard used in the superheat degree judgment processing of a judgment processing part. It is a schematic flowchart which shows the exemplary operation of the determination processing part and the inflow control part. It is a conceptual graph of the judgment standard used in the superheat degree judgment processing.

<First Embodiment>
FIG. 1 is a schematic view of the power generation device 100 of the first embodiment. The power generation device 100 will be described with reference to FIG.

The power generation device 100 includes a heat recovery unit 110 configured to recover heat from a heating medium having a temperature higher than that of the working medium by using a working medium, and a generator 120.

The heat recovery unit 110 is configured to perform the Rankine cycle. The heat recovery unit 110 includes a medium pump 111 that discharges the working medium, and a circulation path 112 that is connected to the discharge port and the suction port of the medium pump 111 and forms a circulation path through which the working medium circulates. .. The heat recovery unit 110 further includes an evaporator 113, an expander 114, and a condenser 115 arranged on the circulation path 112. The evaporator 113, the expander 114, and the condenser 115 are arranged so that the working medium sent out from the medium pump 111 passes through them in sequence.

The evaporator 113 is configured to exchange heat with the heating medium and recover the heat of the heating medium to the working medium. The heating medium is a fluid having a high temperature sufficient for vaporizing the working medium, and is supplied from the outside of the power generation device 100. The heating medium may be exhaust gas from the engine or other fluid having a temperature high enough to vaporize the working medium.

The expander 114 is configured to suck in the working medium vaporized by the evaporator 113 and rotate the internal rotor by the expanding action of the working medium. The rotor of the expander 114 is connected to the generator 120 to drive the generator 120.

The condenser 115 is configured to exchange heat with the cooling medium supplied from the outside of the power generation device 100 in the working medium flowing out of the expander 114. As the cooling medium, a fluid having a temperature sufficiently low to liquefy the working medium (for example, seawater, water, coolant, etc.) is used.

The medium pump 111 is a circulation path 112 from the outlet of the evaporator 113 to the inlet of the expander 114 in the pipe pressure (that is, a part of the circulation path 112 described above) connecting the evaporator 113 and the expander 114. Pressure in the pipe) and the degree of superheat of the working medium flowing through the pipe 116. The power generation device 100 includes an inflow control unit 131, a pressure detection unit 132, a temperature detection unit 133, and a determination processing unit 134 as control-related parts used for controlling the medium pump 111.

Both the pressure detection unit 132 and the temperature detection unit 133 are attached to the pipeline 116. As the pressure detection unit 132, a pressure sensor capable of detecting the pressure inside the pipe line 116 can be used. As the temperature detection unit 133, a temperature sensor capable of detecting the temperature of the working medium flowing through the conduit 116 can be used.

The determination processing unit 134 connects the pressure detection unit 132 and the temperature detection unit 133 to the pressure detection unit 132 and the temperature detection unit 133 so that the detection signals representing the pressure in the pipe and the temperature of the operating medium are received from the pressure detection unit 132 and the temperature detection unit 133, respectively. It is connected to the. The determination processing unit 134 is configured to perform a predetermined determination process using the information represented by the detection signals from the pressure detection unit 132 and the temperature detection unit 133. In addition, the determination processing unit 134 is configured to transmit the determination result obtained from the determination processing to the inflow control unit 131.

The inflow control unit 131 is configured to determine the operation content of maintaining, increasing, or decreasing the rotation speed of the medium pump 111 based on the determination result transmitted from the determination processing unit 134. Has been done. The inflow control unit 131 is configured to generate a drive signal so that the medium pump 111 operates according to the determined operation content. That is, the inflow control unit 131 is configured to control the medium pump 111 based on the determination result obtained from the determination processing unit 134. The inflow of the working medium into the evaporator 113 is controlled through the control of the medium pump 111. The determination processing unit 134 and the inflow control unit 131 may be formed by using a CPU (Central Processing Unit) that executes a program that performs the above-mentioned determination processing and operation content determination, and a signal generation circuit that generates a drive signal.

The flow of the working medium in the power generation device 100 will be described below.

The working medium of the liquid phase is pumped to the evaporator 113 by the medium pump 111. The working medium flows into the evaporator 113 and exchanges heat with the heating medium. As a result, the working medium vaporizes. The vaporized working medium flows into the expander 114 and expands in the expander 114. As a result of the expansion of the working medium in the inflator 114, the rotor of the inflator 114 rotates and the generator 120 connected to the rotor produces electric power. The working medium used for work in the inflator 114 flows from the inflator 114 into the condenser 115. The working medium exchanges heat with the cooling medium in the condenser 115 and returns to the liquid phase. The working medium of the liquid phase is sucked by the medium pump 111 and then sent back to the evaporator 113.

The operations of the determination processing unit 134 and the inflow control unit 131 will be described below with reference to FIGS. 1 and 2. FIG. 2 is a schematic flowchart showing an exemplary operation of the determination processing unit 134 and the inflow control unit 131.

An upper limit threshold value is set for the pressure inside the pipe line 116 for the judgment processing of the judgment processing unit 134. The upper limit threshold is set to a value smaller than the maximum internal pressure allowed by the pipe 116 so that the pressure inside the pipe does not exceed the pressure resistance capacity of the pipe 116. The difference between the upper limit threshold and the maximum internal pressure of the conduit 116 is preferably determined in consideration of the maximum value that the pipe pressure increasing beyond the upper threshold is expected to take.

In addition, a control target range is set for the degree of superheat of the working medium flowing through the conduit 116. For example, the lower limit of the control target range is that the amount of power generated by the generator 120 is the lower limit allowable value (the lower limit value allowed for the amount of power generation or the rotation speed of the generator 120 is the stable power generation of the generator 120). It may take a predetermined value set so as not to fall below the lower limit of the possible rotation speed). The upper limit of the control target range is a predetermined value set in consideration of the upper limit of the capacity of the expander 114 and the generator 120.

The determination processing unit 134 waits for the reception of the detection signal from the pressure detection unit 132 and the temperature detection unit 133 (step S110). When the determination processing unit 134 receives the detection signals, the determination processing unit 134 calculates the degree of superheat of the working medium from the pressure in the pipe and the temperature of the working medium represented by these detection signals (step S120). The determination processing unit 134 then executes an upper limit determination process using the above-mentioned upper limit threshold value (step S130). Regarding the upper limit determination process, the determination processing unit 134 compares the in-pipe pressure represented by the detection signal from the pressure detection unit 132 with the upper limit threshold value, and determines whether or not the in-pipe pressure exceeds the upper limit threshold value. If the in-pipe pressure exceeds the upper limit threshold value (step S130: Yes), a determination result indicating that the in-pipe pressure exceeds the upper limit threshold value is transmitted from the determination processing unit 134 to the inflow control unit 131. In this case, the inflow control unit 131 determines to reduce the rotation speed of the medium pump 111 (step S150). The inflow control unit 131 generates a drive signal so that the rotation speed of the medium pump 111 decreases. The drive signal is output from the inflow control unit 131 to the medium pump 111, and the medium pump 111 rotates at a reduced rotation speed. When the rotation speed of the medium pump 111 is reduced, the amount of inflow of the working medium into the evaporator 113 and the amount of vaporization of the working medium in the evaporator 113 are reduced, and the pressure in the pipe line 116 is reduced. After that, step S110 is executed again. The processing loop including steps S110, S120, S130 and S150 is repeated until a determination result is obtained in the upper limit determination process of step S130 that the pressure in the pipe does not exceed the upper limit threshold value.

If the pressure in the pipe does not exceed the upper limit threshold value (step S130: No), the determination processing unit 134 executes the superheat degree determination process using the above-mentioned control target range (step S140). Regarding the superheat degree determination process, the determination processing unit 134 compares the lower limit and the upper limit of the above-mentioned control target range with the superheat degree calculated in step S120, and the superheat degree of the working medium in the pipeline 116 is the control target range. Determine if it fits in. If the degree of superheat is equal to or greater than the lower limit of the control target range and equal to or less than the upper limit (step S140: Yes), the determination result that the degree of superheat is within the control target range is transmitted from the determination processing unit 134 to the inflow control unit 131. In this case, the inflow control unit 131 determines to maintain the rotation speed of the medium pump 111 (step S160). The inflow control unit 131 generates a drive signal so as to maintain the rotation speed of the inflow control unit 131. The drive signal is output from the inflow control unit 131 to the medium pump 111, and the medium pump 111 discharges the working medium to the evaporator 113 without changing the rotation speed. As a result, the degree of superheat of the working medium in the conduit 116 remains within the control target range. After that, step S110 is executed again.

If the degree of superheat is below the lower limit of the control target range (step S140: No, lower), the determination result that the degree of superheat is below the lower limit of the control target range is from the determination processing unit 134 to the inflow control unit 131. Is transmitted to. In this case, the inflow control unit 131 determines to reduce the rotation speed of the medium pump 111 (step S150). The inflow control unit 131 generates a drive signal so that the rotation speed of the medium pump 111 decreases. The drive signal is output from the inflow control unit 131 to the medium pump 111, and the medium pump 111 rotates at a reduced rotation speed. When the rotation speed of the medium pump 111 is reduced, the inflow of the working medium from the medium pump 111 to the evaporator 113 is reduced, so that the degree of superheat of the working medium in the pipeline 116 is increased. As a result, the degree of superheat of the working medium falls within the control target range. After that, step S110 is executed again.

If the degree of superheat exceeds the upper limit of the control target range (step S140: No, upper), the determination result that the degree of superheat exceeds the upper limit of the control target range is from the determination processing unit 134 to the inflow control unit 131. Is transmitted to. In this case, the inflow control unit 131 determines to increase the rotation speed of the medium pump 111 (step S170). The inflow control unit 131 generates a drive signal so as to increase the rotation speed of the inflow control unit 131. The drive signal is output from the inflow control unit 131 to the medium pump 111, and the medium pump 111 rotates at an increased rotation speed. Since the inflow amount of the working medium from the medium pump 111 to the evaporator 113 increases, the degree of superheat of the working medium in the pipeline 116 decreases. As a result, the degree of superheat of the working medium falls within the control target range. After that, step S110 is executed again.

As described above, the processing loop including steps S110, S120, S130 and S150 is repeated until a determination result is obtained in the upper limit determination process of step S130 that the pressure in the pipe does not exceed the upper limit threshold value. Therefore, the superheat degree determination process in step S140 is performed under the condition that the pressure inside the pipe does not exceed the upper limit threshold value. That is, the control of the inflow amount of the working medium based on the superheat degree determination process is performed under the condition that the pressure in the pipe does not exceed the upper limit threshold value. When the inflow amount of the working medium is controlled based on the superheat degree determination process, even if the inflow amount to the evaporator 113 is increased, the in-pipe pressure only increases from a value below the upper limit threshold value, and the in-pipe pressure is increased. Does not become an excessively large value.

The lower limit of the control target range used in the superheat degree determination process is set so that the amount of power generated by the generator 120 does not fall below the lower limit allowable value. Therefore, when the degree of superheat is equal to or higher than the lower limit of the control target range, the generator 120 can generate electric power exceeding the lower limit allowable value.

If the degree of superheat is below the lower limit of the control target range and the degree of superheat is increased, the amount of power generated by the generator 120 increases. According to the control described with reference to FIG. 2, when the degree of superheat is below the lower limit of the control target range, step S150 is executed and the rotation speed of the medium pump 111 is reduced (ie, the evaporator 113). The inflow of working medium to is reduced). As a result, the degree of superheat of the working medium flowing out of the evaporator 113 increases. As a result of the increase in the degree of superheat, the amount of power generated by the generator 120 increases. Therefore, the amount of power generated by the generator 120 can be maintained at a high level to some extent.

The upper limit determination process is performed before the superheat degree determination process. If the superheat degree determination process is performed before the upper limit determination process, the control of the inflow amount of the working medium based on the superheat degree determination process can be performed under the condition that the pipe pressure has already reached a high value. .. In this case, if it is determined in the superheat degree determination process that the superheat degree is higher than the upper limit of the control target range, the inflow amount of the working medium into the evaporator 113 is increased, and the pressure in the pipe is further increased. .. On the other hand, according to the control described with reference to FIG. 2, the upper limit determination process is performed before the superheat degree determination process. Therefore, when the in-pipe pressure exceeds the upper threshold, the inflow of the working medium into the evaporator 113 is reduced and the in-pipe pressure is reduced under the processing loop consisting of steps S110, S120, S130 and S150. Since the inflow amount of the working medium is controlled based on the superheat degree determination process after the pressure inside the pipe is reduced, the pressure inside the pipe does not take an excessively high value.

In the determination process shown in FIG. 2, the in-pipe pressure is compared with the upper threshold. However, the in-pipe pressure may be additionally compared with a predetermined lower limit threshold value to determine whether or not the in-pipe pressure is below the lower limit threshold value (lower limit determination process). The lower limit threshold value may be set so that the amount of power generated by the generator 120 does not fall below the lower limit allowable value even if the pressure in the pipe falls below the lower limit threshold value. In addition, the calculation of the degree of superheat may be executed when the degree of superheat determination process is performed. FIG. 3 is a schematic flowchart showing the determination process to which these changes have been made.

The lower limit determination process (step S131) is performed by the determination processing unit 134 together with the upper limit determination process after step S110. In the lower limit determination process, if a determination result that the pipe pressure is below the lower limit threshold value is obtained (step S131: No, lower limit threshold value> pipe pressure), the determination result is transmitted from the determination processing unit 134 to the inflow control unit 131. It is output. The inflow control unit 131 increases the rotation speed of the medium pump 111 based on the determination result (step S170).

On the condition that in the lower limit determination process, a determination result that the pipe pressure is equal to or higher than the lower limit threshold value is obtained, and in the upper limit determination process, a determination result that the pipe pressure is equal to or lower than the upper limit threshold value is obtained (step). S131: Yes), the calculation of the degree of superheat (step S132), and the process of determining the degree of superheat (step S140) are performed. The calculation process of the degree of superheat in step S132 is the same as in step S120 described with reference to FIG.

Since the lower limit determination process is performed in addition to the upper limit determination process, when the determination result that the pressure in the pipe is lower than the lower limit threshold value is obtained in the lower limit determination process, the inflow control unit 131 rotates the medium pump 111. Is increased. As a result, the inflow of the working medium from the medium pump 111 to the evaporator 113 increases. As a result of the increase in the inflow of the working medium, the amount of power generation increases.

The calculation of the degree of superheat is performed when the condition for performing the degree of superheat determination process (that is, the condition that the pressure in the pipe is within the pressure range of the lower limit threshold value or more and the upper limit threshold value or less) is satisfied. When the superheat degree determination process is not performed, the superheat degree is not calculated. As a result, unnecessary arithmetic processing is reduced, and the arithmetic load of the determination processing unit 134 is reduced.

In addition to the upper limit determination process, the determination processing unit 134 may determine whether or not the rotation speed of the medium pump 111 exceeds a predetermined rotation speed threshold value (rotation speed determination process). The rotation speed threshold is set in consideration of the maximum value predicted when the rotation speed of the medium pump 111 increases beyond the rotation speed threshold. Even if the medium pump 111 rotates at the predicted maximum value, the magnitude of the rotation speed threshold is set so that the pressure inside the pipe does not exceed a predetermined value set below the pressure resistance capacity of the pipe 116. You may. A schematic diagram of the power generation device 100 that executes the rotation speed determination process is shown in FIG. A flowchart showing the operation of the determination processing unit 134 including the rotation speed determination process is shown in FIG. The rotation speed determination process will be described with reference to FIGS. 1 and 5.

When the determination processing unit 134 performs the rotation speed determination processing, a rotation speed signal representing the rotation speed of the medium pump 111 is output to the determination processing unit 134. The rotation speed signal may be generated by, for example, a speed detector 136 such as an encoder attached to the medium pump 111 to detect the rotation speed of the medium pump 111. In this case, the rotation speed signal is output from the speed detector 136 to the determination processing unit 134.

The determination processing unit 134 receives the rotation speed signal together with the detection signals from the pressure detection unit 132 and the temperature detection unit 133 (step S111). After that, the calculation of the degree of superheat (step S120) and the upper limit determination process (step S130) are sequentially executed. After the upper limit determination process, the rotation speed determination process is executed (step S133).

Regarding the rotation speed determination processing, the determination processing unit 134 compares the rotation speed represented by the rotation speed signal with the rotation speed threshold value. If the rotation speed of the medium pump 111 exceeds the rotation speed threshold value (step S133: No), the determination result indicating that the rotation speed exceeds the rotation speed threshold value is obtained from the determination processing unit 134 to the inflow control unit 131. Is transmitted to. Based on the determination result, the inflow control unit 131 reduces the rotation speed of the medium pump 111 to a value equal to or less than the rotation speed threshold value (step S150), and reduces the inflow amount of the working medium from the medium pump 111 to the evaporator 113. On the condition that the determination result that the rotation speed does not exceed the rotation speed threshold value is obtained in the rotation speed determination process (step S133: Yes), the determination processing unit 134 performs the superheat degree determination process (step S140). To execute.

When the rotation speed of the medium pump 111 exceeds the rotation speed threshold value, even if the pressure inside the pipe detected by the pressure detection unit 132 is low, it is predicted that the pressure inside the pipe will increase thereafter and exceed the upper limit threshold value. However, when the rotation speed determination process is performed and the rotation speed of the medium pump 111 exceeds the rotation speed threshold value, the rotation speed is lowered, so that the pressure inside the pipe is prevented from exceeding the upper limit threshold value. To.

In the series of processes shown in FIG. 5, the rotation speed determination process is performed after the upper limit determination process. However, the rotation speed determination process may be performed before the upper limit determination process or at the same time as the upper limit determination process.

In the series of processes shown in FIG. 5, the upper limit determination process (step S130) is performed, but instead of this, the upper limit determination process and the lower limit determination process (step S131) shown in FIG. 3 may be performed. Good.

Regarding the above-described embodiment, the superheat degree determination process is performed after the upper limit determination process. However, the degree of superheat may be constantly monitored while the power generation device 100 is operating. As long as the control of the inflow amount of the working medium based on the superheat degree determination process is performed after the upper limit determination process, the excessive increase in the pipe pressure is suppressed as described above.

With respect to the above-described embodiment, the heat recovery unit 110 may further include a superheater that further heats the working medium vaporized by the evaporator 113.

With respect to the above embodiment, the speed detector 136 detects the rotation speed of the medium pump 111. However, the speed detector 136 may detect the inverter frequency of the motor that drives the medium pump 111.

With respect to the above-described embodiment, the inflow of the working medium into the evaporator 113 is adjusted through the control of the rotation speed of the medium pump 111. In addition to controlling the rotation speed, a bypass configured so that a part of the working medium discharged from the medium pump 111 flows in and the flowing working medium bypasses the medium pump 111 and returns to the upstream of the medium pump 111. The inflow to the evaporator 113 may be adjusted by using the flow path. In this case, the inflow amount of the working medium into the evaporator 113 is adjusted by controlling the opening degree of the valve body provided in the bypass flow path.

<Second Embodiment>
FIG. 6 is a schematic view of the power generation device 100A of the second embodiment. The power generation device 100A will be described with reference to FIGS. 1 and 6.

The power generation device 100A is different from the power generation device 100 in that it further includes a temperature detection unit 135 for detecting the temperature of the heating medium flowing into the evaporator 113 and in the determination processing of the determination processing unit 134. Except for these differences, the description of the power generation device 100 is incorporated into the power generation device 100A.

The temperature detection unit 135 is attached to a pipeline laid upstream of the evaporator 113 in the flow direction of the heating medium. As the temperature detection unit 135, a temperature sensor capable of detecting the temperature of the heating medium flowing through the pipeline upstream of the evaporator 113 can be used.

The temperature detection unit 135 is configured to generate a detection signal indicating the temperature of the heating medium. The temperature detection unit 135 is connected to the determination processing unit 134 in a wired or wireless manner so that the detection signal is output from the temperature detection unit 135 to the determination processing unit 134.

The determination processing unit 134 executes the temperature determination process instead of the above-mentioned upper limit determination process. In the temperature determination process, the determination processing unit 134 compares the temperature of the heating medium represented by the detection signal from the temperature detection unit 135 with a predetermined temperature threshold value, and determines whether or not the temperature of the heating medium exceeds the temperature threshold value. To judge.

The determination processing unit 134 executes the superheat degree determination process after the temperature determination process. In the superheat degree determination process, the determination process unit 134 uses different determination criteria depending on the result of the temperature determination process. FIG. 7 is a conceptual graph of the determination criteria used in the superheat degree determination process. The superheat degree determination process of the determination process unit 134 will be described with reference to FIGS. 2, 6 and 7.

The horizontal axis of the graph of FIG. 7 represents the temperature of the heating medium detected by the temperature detection unit 135. The vertical axis of the graph of FIG. 7 represents the degree of superheat of the working medium flowing through the conduit 116.

When a determination result (step S134: No) that the temperature of the heating medium is equal to or lower than the temperature threshold value is obtained in the temperature determination process, the determination process unit 134 uses the first control target range to determine the degree of superheat. It is determined whether or not it is within the first control target range. The lower and upper limits of the first control target range are constant values regardless of the temperature of the heating medium. The first control target range is the same as the control target range described with reference to FIG. The description of the control target range described with reference to FIG. 2 is incorporated into the first control target range.

In the temperature determination process, when a determination result (step S134: Yes) that the temperature of the heating medium exceeds the temperature threshold value is obtained, the determination process unit 134 performs the second control higher than the first control target range. Using the target range, it is determined whether or not the degree of superheat is within the second control target range. The lower limit of the second control target range is set to a value larger than the lower limit of the first control target range. The upper limit of the second control target range is set to a value larger than the upper limit of the first control target range. The lower and upper limits of the second control target range take larger values as the temperature of the heating medium becomes larger than the temperature threshold value. In FIG. 7, when the temperature of the heating medium is at the temperature threshold value, the upper limit value of the first control target range matches the upper limit value of the second control target range, and the lower limit value of the first control target range is the second control. It matches the lower limit of the target range. Alternatively, when the temperature of the heating medium is at the temperature threshold, the upper limit of the second control target range may be larger than the upper limit of the first control target range, and the lower limit of the second control target range is It may be larger than the lower limit of the first control target range. In FIG. 7, the lower and upper limits of the second control target range increase linearly, but may increase non-linearly. The difference between the upper limit and the lower limit of the second control target range in FIG. 7 is equal to the difference between the upper limit and the lower limit of the first control target range in FIG. Alternatively, the difference between the upper limit and the lower limit of the second control target range may be larger or smaller than the difference between the upper limit and the lower limit of the first control target range.

Regarding the setting of the temperature threshold value and the second control target range, under the superheat degree determination process using the first control target range, the pressure inside the pipe 116 is set in consideration of the pressure resistance capacity of the pipe 116. The amount of evaporation per unit time of the working medium, which may be too close to the pressure, is taken into account. That is, the temperature threshold value is set to a value at which the amount of evaporation of the working medium per unit time is predicted to be too large under the superheat degree determination process using the first control target range. The lower and upper limits of the second control target range are set so that the amount of evaporation of the working medium per unit time does not become too large under the temperature of the heating medium exceeding the temperature threshold.

The operations of the determination processing unit 134 and the inflow control unit 131 will be described below with reference to FIGS. 6 to 8. FIG. 8 is a schematic flowchart showing an exemplary operation of the determination processing unit 134 and the inflow control unit 131.

The determination processing unit 134 waits for the reception of the detection signals from the temperature detection units 133 and 135 and the pressure detection unit 132 (step S112), and after receiving these detection signals, the degree of superheat is calculated (step S120). After calculating the degree of superheat, the temperature determination process (step S134) is executed.

In the temperature determination process (step S134), the determination process unit 134 compares the temperature of the heating medium represented by the detection signal from the temperature detection unit 135 with the temperature threshold value. If a determination result (step S134: No) that the temperature of the heating medium does not exceed the temperature threshold value is obtained, the determination processing unit 134 performs the superheat degree determination process (step S141) using the first control target range. Execute. If a determination result (step S134: Yes) that the temperature of the heating medium exceeds the temperature threshold value is obtained, the determination processing unit 134 performs the superheat degree determination process (step S142) using the second control target range. Execute.

In the superheat degree determination process (steps S141 and S142), any of the following determination results can be obtained.
(Judgment result 1) Judgment result that the calculated degree of superheat (step S120) is below the lower limit of the first control target range or the second control target range (step S141: No, lower, or step S142: No, bottom).
(Determination result 2) Judgment result (step S141: Yes or step S142: Yes) that the calculated degree of superheat (step S120) is within the range of the first control target range or the second control target range. ).
(Judgment result 3) Judgment result that the calculated degree of superheat (step S120) exceeds the range of the first control target range or the second control target range (step S141: No, above, or step S142: No, above).

The obtained determination result is transmitted from the determination processing unit 134 to the inflow control unit 131. When the above-mentioned determination result 1 is output to the inflow control unit 131, the inflow control unit 131 lowers the rotation speed of the medium pump 111 (step S150). In this case, since the inflow amount of the working medium into the evaporator 113 is reduced, the degree of superheat of the working medium in the conduit 116 is increased and falls within the control target range. When the above-mentioned determination result 2 is output to the inflow control unit 131, the inflow control unit 131 maintains the rotation speed of the medium pump 111 (step S160). In this case, the degree of superheat of the working medium in the conduit 116 remains within the control target range. When the above-mentioned determination result 3 is output to the inflow control unit 131, the inflow control unit 131 increases the rotation speed of the medium pump 111 (step S170). In this case, since the inflow amount of the working medium into the evaporator 113 increases, the degree of superheat of the working medium in the conduit 116 decreases, and the amount falls within the control target range.

In the temperature range higher than the temperature threshold, the upper limit of the second control target range is set to a value larger than the upper limit of the first control target range. Therefore, in the determination result 3, the second control target range is used. At that time (step S142), it is more difficult to obtain than when the first control target range is used (step S141). On the other hand, the lower limit of the second control target range is set to a value larger than the lower limit of the first control target range. Therefore, the determination result 1 is more likely to be obtained when the second control target range is used (step S142) than when the first control target range is used (step S141). Therefore, when step S142 is executed, the control for increasing the rotation speed of the medium pump 111 (step S170) is difficult to be performed, while the control for decreasing the rotation speed of the medium pump 111 (step S150) is likely to be performed. It has become. That is, when step S142 is executed, the supply of the working medium from the medium pump 111 to the evaporator 113 is suppressed. As a result, the evaporation of the working medium in the evaporator 113 and the increase in the pressure inside the pipe line 116 are also suppressed.

Regarding the above-described embodiment, the determination processing unit 134 performs the determination processing using one temperature threshold value. However, the determination processing unit 134 may perform the determination processing using a plurality of temperature threshold values. The determination process of the determination processing unit 134 when a plurality of temperature threshold values are used will be described with reference to FIGS. 6 and 9. FIG. 9 is a conceptual graph of the determination criteria used in the superheat degree determination process.

The horizontal axis of the graph of FIG. 9 represents the temperature of the heating medium detected by the temperature detection unit 135. The vertical axis of the graph of FIG. 9 represents the degree of superheat of the working medium flowing through the conduit 116.

The symbols "T1" to "T4" shown in FIG. 9 are temperature threshold values used in the temperature determination process (T1 <T2 <T3 <T4). In the superheat degree determination process, five control target ranges classified by the temperature thresholds T1 to T4 are used. In the temperature determination process, when the determination result that the temperature of the heating medium is equal to or less than the temperature threshold value T1 is obtained, the control target range used in the superheat degree determination process is described in the following description as "1st control target". It is called "range". In the following description, the control target range used in the superheat degree determination process when the determination result that the temperature of the heating medium is larger than the temperature threshold value T1 and equal to or less than the temperature threshold value T2 is obtained in the temperature determination process is described in the following description. It is called the "second control target range". In the following description, the control target range used in the superheat degree determination process when the determination result that the temperature of the heating medium is larger than the temperature threshold value T2 and equal to or less than the temperature threshold value T3 is obtained in the temperature determination process is described in the following description. It is called the "third control target range". In the following description, the control target range used in the superheat degree determination process when the determination result that the temperature of the heating medium is larger than the temperature threshold value T3 and equal to or less than the temperature threshold value T4 is obtained in the temperature determination process is described in the following description. It is called the "fourth control target range". In the temperature determination process, when the determination result that the temperature of the heating medium exceeds the temperature threshold value T4 is obtained, the control target range used in the superheat degree determination process is described in the following description as "fifth control". It is called "target range".

The lower and upper limits of each of the first control target range to the fifth control target range are constant. However, the lower limit and the upper limit are different from each other between the first control target range and the fifth control target range. The lower and upper limits of the second control target range are larger than the lower and upper limits of the first control target range. The lower and upper limits of the third control target range are larger than the lower and upper limits of the second control target range. The lower and upper limits of the fourth control target range are larger than the lower and upper limits of the third control target range. The lower and upper limits of the fifth control target range are larger than the lower and upper limits of the fourth control target range.

In the superheat degree determination process, any one of the first control target range to the fifth control target range is selected based on the temperature of the heating medium (temperature detected by the temperature detection unit 135). When the determination result that the superheat degree is below the lower limit of the selected control target range is obtained in the superheat degree determination process, the inflow control unit 131 lowers the rotation speed of the medium pump 111. When the determination result that the superheat degree exceeds the upper limit of the selected control target range is obtained in the superheat degree determination process, the inflow control unit 131 increases the rotation speed of the medium pump 111. Even under the setting of the control target range shown in FIG. 9, as the temperature of the heating medium increases, the inflow amount of the working medium from the medium pump 111 to the evaporator 113 and the increase in the pressure in the pipe line 116 are suppressed. ..

In the above-described embodiment, the temperature detection unit 135 detects the temperature of the heating medium flowing through the pipeline piped upstream of the evaporator 113. However, the temperature detection unit 135 may detect the temperature of the heating medium flowing through the pipeline piped downstream of the evaporator 113.

The technique of the above-described embodiment is suitably used in various technical fields in which electric power generation is required.

100, 100A ・ ・ ・ ・ ・ Power generation device 110 ・ ・ ・ ・ ・ ・ ・ ・ Heat recovery unit 111 ・ ・ ・ ・ ・ ・ ・ ・ Medium pump 113 ・ ・ ・ ・ ・ ・ ・ ・ Evaporator 114 ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Expander 115 ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Condenser 120 ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Generator 131 ・ ・ ・ ・ ・ ・ ・ ・Inflow control unit 134 ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Judgment processing unit

Claims (7)

The heat of the heating medium supplied to the evaporator is recovered by circulating the working medium sent out by the medium pump so as to return to the medium pump after passing through the evaporator, the expander, and the condenser in this order. Heat recovery unit and
The generator driven by the expander and
An upper limit determination process for determining whether or not the pressure in the pipe connecting the evaporator and the expander exceeds a predetermined upper threshold value, and a control target in which the degree of superheat of the working medium in the pipe is a predetermined control target. A determination processing unit that executes a superheat degree determination process that determines whether or not it is within the range, and a determination process unit that executes
An inflow control unit that controls the inflow amount of the working medium into the evaporator based on the result of the determination process of the determination processing unit is provided.
When the determination result that the pressure in the pipe is equal to or lower than the upper limit threshold value is obtained in the upper limit determination process, the inflow control unit determines the superheat degree based on the determination result of the superheat degree determination process. Control the inflow amount so that it falls within the control target range,
When the determination result that the pipe pressure exceeds the upper limit threshold value is obtained in the upper limit determination process, the inflow control unit sets the inflow amount so that the pipe pressure becomes equal to or less than the upper limit threshold value. A power generation device that controls the inflow amount so that the superheat degree falls within the control target range based on the determination result of the superheat degree determination process after reducing the amount. The determination processing unit further executes a lower limit determination process for determining whether or not the pressure in the pipe is below a predetermined lower limit threshold value.
When the pressure in the pipe is within the pressure range determined by the lower limit threshold value and the upper limit threshold value, the inflow control unit sets the superheat degree to the control target based on the determination result of the superheat degree determination process. Control the inflow so that it falls within the range,
When the pressure inside the pipe is outside the pressure range, the inflow control unit adjusts the inflow amount so that the pressure inside the pipe falls within the pressure range, and then the determination result of the superheat degree determination process. The power generation device according to claim 1, wherein the inflow amount is controlled so that the degree of superheat falls within the control target range based on the above. The determination processing unit further executes a rotation speed determination process for determining whether or not the rotation speed of the medium pump exceeds a predetermined rotation speed threshold value.
In the upper limit determination process, a determination result that the pressure in the pipe is equal to or lower than the upper limit threshold value is obtained, and in the rotation speed determination process, the rotation speed of the medium pump is equal to or less than the rotation speed threshold value. When the determination result is obtained, the inflow control unit controls the inflow amount so that the superheat degree falls within the control target range based on the determination result of the superheat degree determination process.
When the determination result that the rotation speed of the medium pump exceeds the rotation speed threshold is obtained in the rotation speed determination process, the inflow control unit rotates the rotation speed of the medium pump. The power generation device according to claim 1 or 2, wherein the inflow amount is reduced by reducing the value to a value equal to or less than a few thresholds. The heat of the heating medium supplied to the evaporator is recovered by circulating the working medium sent out by the medium pump so as to return to the medium pump after passing through the evaporator, the expander, and the condenser in this order. Heat recovery unit and
The generator driven by the expander and
In the temperature determination process of determining whether or not the temperature of the heating medium for evaporating the operating medium exceeds a predetermined temperature threshold by exchanging heat with the operating medium in the evaporator, and the heating in the temperature determination process. When it is determined that the temperature of the medium exceeds the temperature threshold, the control target range of the degree of superheat of the working medium in the conduit connecting the evaporator and the expander is raised. A determination processing unit that executes a superheat degree determination process for determining whether or not the superheat degree is within the control target range, and a determination processing unit that executes the operation.
Based on the result of the superheat degree determination process, an inflow control unit that controls the inflow amount of the working medium into the evaporator so that the superheating degree of the working medium falls within the control target range is provided. Power generation equipment. The heat of the heating medium supplied to the evaporator is recovered by circulating the working medium sent out by the medium pump so as to return to the medium pump after passing through the evaporator, the expander, and the condenser in this order. Heat recovery unit and
The generator driven by the expander and
In the temperature determination process of determining whether or not the temperature of the heating medium for evaporating the operating medium exceeds a predetermined temperature threshold by exchanging heat with the operating medium in the evaporator, and the heating in the temperature determination process. When it is determined that the temperature of the medium is equal to or lower than the temperature threshold, the degree of superheat of the working medium in the conduit connecting the evaporator and the expander is the first control target of the degree of superheat. When it is determined whether or not it is within the range and the determination result that the temperature of the heating medium exceeds the temperature threshold is obtained, the second control target range higher than the first control target range is set. A determination processing unit that executes the overheat determination process for determining whether or not the overheat degree is contained, and
When the determination result that the temperature of the heating medium is equal to or lower than the temperature threshold is obtained, the superheat degree is within the first control target range based on the result of the superheat degree determination process. When the inflow amount of the working medium into the evaporator is controlled and the determination result that the temperature of the heating medium exceeds the temperature threshold is obtained, the degree of superheat is the second control target range. A power generation device including an inflow control unit that controls the inflow amount so as to fit in the above. The working medium sent out by the medium pump is circulated so as to pass through the evaporator, the expander, and the condenser in this order and then returned to the medium pump, and the power generation device for driving the generator by using the expander is controlled. It ’s a method,
Executing the upper limit determination process for determining whether or not the pressure in the pipe connecting the evaporator and the expander exceeds a predetermined upper limit threshold value, and
In the upper limit determination process, when the determination result that the pressure in the pipe is equal to or lower than the upper limit threshold value is obtained, the degree of superheat of the working medium in the pipeline is within a predetermined control target range. Controlling the inflow of the working medium into the evaporator and
In the upper limit determination process, when a determination result that the in-pipe pressure exceeds the upper limit threshold value is obtained, the inflow amount is reduced so that the in-pipe pressure becomes equal to or less than the upper limit threshold value, and then the inflow amount is reduced. A method for controlling a power generation device, comprising controlling the inflow amount so that the degree of superheat falls within the control target range. The working medium sent out by the medium pump is circulated so as to pass through the evaporator, the expander, and the condenser in this order and then returned to the medium pump, and the power generation device for driving the generator by using the expander is controlled. It ’s a method,
A temperature determination process for determining whether or not the temperature of the heating medium for evaporating the working medium exceeds a predetermined temperature threshold by exchanging heat with the working medium in the evaporator is executed.
In the temperature determination process, when a determination result is obtained that the temperature of the heating medium exceeds the temperature threshold, the degree of superheat of the working medium in the conduit connecting the evaporator and the expander is obtained. By raising the control target range for the control target range and executing the superheat degree determination process for determining whether or not the superheat degree is within the control target range.
A power generation device including controlling the inflow amount of the working medium into the evaporator so that the superheating degree of the working medium falls within the control target range based on the result of the superheat degree determination process. Control method.

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