JP6394862B2 - Waste heat power generator - Google Patents

Description

  The present invention relates to a waste heat power generation apparatus.

  Conventionally, power generation is performed by recovering waste heat energy released in factories, incineration facilities, and the like, and energy is saved by reusing electric energy obtained by this power generation. In such factories and facilities, waste heat of about 300 ° C. or higher (nearly 1000 ° C. in some cases) is used for power generation because it easily generates high-pressure steam for driving the generator. Most of the low-temperature waste heat below ℃ was still released into the atmosphere. For this reason, it is considered that further energy saving can be realized by recovering waste heat energy of low-temperature waste heat that has hardly been collected in the past and generating power.

  Patent Document 1 below discloses a waste heat power generation apparatus that generates power using waste heat energy of low temperature waste heat of 300 ° C. or lower by a Rankine cycle using a low boiling point working medium. Specifically, the waste heat power generation apparatus disclosed in Patent Document 1 below includes a waste heat recovery device, a steam turbine, a condenser, and a high-pressure pump, and the low-temperature waste heat recovered by the waste heat recovery device. Is used to generate high-pressure steam as a low-boiling working medium, and the steam turbine is driven by this high-pressure steam to generate electricity. The exhaust gas from the steam turbine is condensed and liquefied by a condenser, and the liquefied low boiling point working medium is sent to a waste heat recovery device for circulation.

JP 2000-110514 A

  By the way, the above-described waste heat power generation apparatus circulates low-temperature waste heat (for example, hot water) for generating high-pressure steam of a low-boiling working medium to a waste heat recovery device, and condenses and liquefies the exhaust of the steam turbine. It is necessary to circulate cooling water through the condenser. Over a long period of operation of the waste heat power generation system, impurities contained in the hot water and cooling water adhere to the waste heat recovery unit and the condenser, respectively. It is necessary to prevent the performance deterioration of the waste heat recovery unit and the condenser by cleaning the vessel. In addition, if the chemical solution is poured into the hot water and the cooling water, any of the waste heat recovery device and the condenser that can remove the dirt temporarily needs to be cleaned.

Here, as a main method of knowing the cleaning timing of the waste heat recovery unit and the condenser, the following methods can be mentioned.
(1) Visual method using sight glass (view window) Sight glass is installed in the waste heat recovery unit and condenser (or pipes connected to these), and dirt inside the waste heat recovery unit and condenser is removed from the sight glass. A method of visual confirmation.
(2) Detection method using relationship between flow rate and differential pressure Relationship between flow rate of hot water and differential pressure (differential pressure between hot water supplied to waste heat recovery unit and hot water recovered from waste heat recovery unit) Change in the relationship between the flow rate of cooling water and the differential pressure (the differential pressure between the cooling water supplied to the condenser and the cooling water recovered from the condenser) To detect dirt inside the condenser. Specifically, when the waste heat recovery device (condenser) is contaminated, the internal pressure of the waste heat recovery device (condenser) is detected because the differential pressure with respect to the flow rate increases.

  However, the method shown in the above (1) has a problem of lack of reliability because the contamination of the waste heat recovery unit and the condenser cannot be measured quantitatively. In the method shown in (2) above, the change in the differential pressure with respect to the flow rate is not caused only by the contamination of the waste heat recovery unit and the condenser, but is also caused by the operating state of the waste heat power generation device. Arise. For this reason, when a change in the differential pressure with respect to the flow rate occurs, it is not clear whether the waste heat recovery unit and the condenser are really necessary for cleaning, and there is a problem that reliability is lacking. In addition, in the method shown in (1) above, it is necessary to add a sight glass, and in the method shown in (2) above, it is necessary to add a differential pressure gauge.

  The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a waste heat power generator capable of detecting an appropriate cleaning timing with high reliability without causing an increase in cost.

In order to solve the above-described problem, the waste heat power generation apparatus of the first invention includes an evaporator (11) that performs heat exchange between the waste heat medium (X) and the working medium (Y) to evaporate the working medium, A turbine generator (12) that generates electric power by supplying the working medium from the evaporator, and exchanges heat between the working medium discharged from the turbine generator and the cooling medium (Z). A waste heat power generator (10) comprising a condenser (13) for condensing and a pump (15) for sending the working medium condensed in the condenser toward the evaporator, wherein the waste heat medium And the first sensor (22, 23) for measuring the temperature of the cooling medium, the second sensor (19, 21) for measuring the temperature and pressure of the working medium, and the measurement results of the first and second sensors. Based on the waste heat medium, the working medium, and the cooling medium Represents a state in TS diagram, it is characterized in that a control device (20) for notifying an alarm in response to a change status of the TS diagram.
In the waste heat power generation apparatus according to the first aspect of the invention, the controller needs to clean the evaporator according to the change state of the pinch temperature difference (ΔT11, ΔT12) between the waste heat medium and the working medium. And an alarm indicating that the condenser needs to be cleaned according to a change state of a pinch temperature difference (ΔT21, ΔT22) between the working medium and the cooling medium. It is said.
Alternatively, in the waste heat power generation apparatus according to the first aspect of the invention, the control device needs to clean the evaporator according to a change state of the approach temperature (ΔT31, ΔT32) between the waste heat medium and the working medium. And an alarm indicating that the condenser needs to be cleaned according to a change state of the approach temperature (ΔT41, ΔT42) between the working medium and the cooling medium. .
Alternatively, the waste heat power generator according to the first aspect of the present invention is the case where the control device increases both the pinch temperature difference (ΔT11, ΔT12) and the approach temperature (ΔT31, ΔT32) between the waste heat medium and the working medium. Notifies the alarm indicating that the evaporator needs to be cleaned, and when both the pinch temperature difference (ΔT21, ΔT22) and the approach temperature (ΔT41, ΔT42) between the working medium and the cooling medium increase. Notifies the alarm indicating that the condenser needs to be cleaned, and the pinch temperature difference between the waste heat medium and the working medium (ΔT11, ΔT12) or the pinch temperature difference between the working medium and the cooling medium ( When only ΔT21 and ΔT22) increase, an alarm indicating that an abnormality has occurred in the turbine generator or the pump is notified.
In order to solve the above problems, the waste heat power generation apparatus of the second invention is connected to the heat exchanger (11) to which the waste heat medium (X) and the working medium (Y) are supplied, and the heat exchanger, A turbine generator (12) to which the working medium is supplied from the heat exchanger, and a condenser (Z) connected to the turbine generator and supplied with the cooling medium (Z) and the working medium from the turbine generator ( 13), a waste heat power generation apparatus (10) in which the working medium output from the condenser is supplied to the heat exchanger, wherein the waste heat power generation apparatus further includes the waste heat medium. And a control device (20) for outputting an alarm based on a change in the relationship between the temperature and entropy of each of the working medium and the cooling medium.
In the waste heat power generator according to the second aspect of the invention, the control device needs to clean the heat exchanger based on a change in pinch temperature difference (ΔT11, ΔT12) between the waste heat medium and the working medium. And an alarm indicating that the condenser needs to be cleaned based on a change in pinch temperature difference (ΔT21, ΔT22) between the working medium and the cooling medium.
Alternatively, in the waste heat power generator according to the second aspect of the invention, the control device needs to clean the heat exchanger based on a change in approach temperature (ΔT31, ΔT32) between the waste heat medium and the working medium. An alarm indicating that the condenser needs to be cleaned based on a change in approach temperature (ΔT41, ΔT42) between the working medium and the cooling medium.
Alternatively, the waste heat power generator according to the second aspect of the present invention is the case where the control device increases both the pinch temperature difference (ΔT11, ΔT12) and the approach temperature (ΔT31, ΔT32) between the waste heat medium and the working medium. Notifies the alarm indicating that the heat exchanger needs to be cleaned, and both the pinch temperature difference (ΔT21, ΔT22) and the approach temperature (ΔT41, ΔT42) between the working medium and the cooling medium increase. Alarms indicating that the condenser needs to be cleaned, and the pinch temperature difference (ΔT11, ΔT12) between the waste heat medium and the working medium or the pinch temperature difference between the working medium and the cooling medium. When only (ΔT21, ΔT22) increases, an alarm indicating that an abnormality has occurred in the turbine generator is notified.

  According to the present invention, the state of the waste heat medium, the working medium, and the cooling medium is shown in the TS diagram based on the measurement result of the waste heat medium and the cooling medium and the measurement result of the temperature and pressure of the working medium. The alarm is reported according to the change state of the TS diagram, or the alarm is output based on the change in the relationship between the temperature and entropy of the waste heat medium, the working medium, and the cooling medium. Therefore, there is an effect that it is possible to detect an appropriate cleaning timing with high reliability without causing an increase in cost.

It is a block diagram which simplifies and shows the whole structure of the waste heat power generator by one Embodiment of this invention. It is a block diagram which shows the principal part structure of the control apparatus with which the waste heat power generator by one Embodiment of this invention is provided. It is a figure which shows an example of the TS diagram used with the waste heat power generator by one Embodiment of this invention. It is a figure for demonstrating approach temperature.

  Hereinafter, a waste heat power generator according to an embodiment of the present invention will be described in detail with reference to the drawings. FIG. 1 is a block diagram showing a simplified overall configuration of a waste heat power generator according to an embodiment of the present invention. As shown in FIG. 1, the waste heat power generation apparatus 10 is a power generation apparatus using a Rankine cycle that includes an evaporator 11, an expansion turbine generator 12 (turbine generator), a condenser 13, a reservoir tank 14, and a pump 15. Then, the waste heat energy of a waste heat medium (about “hot water X” in this embodiment) of about 300 ° C. or less discharged from a factory or an incineration facility is collected to generate power. The waste heat medium is not limited to the hot water X, and a gas released from a factory or an incineration facility can also be used.

  In addition, the waste heat power generation apparatus 10 includes an AC / DC converter 16 and a DC / AC converter 17, and converts the power generated by the expansion turbine generator 12 into three-phase AC power having the same specifications as commercial power. Convert. In addition, the waste heat power generation apparatus 10 includes a measurement device 18, a sensor 19 (second sensor), and a control device 20, and the amount of power generation per unit time (for example, seconds) of the expansion turbine generator 12 and expansion. Based on the measurement results of the temperature and pressure of the working medium Y supplied to the turbine generator 12, the drive of the pump 15 is controlled so that the largest amount of power can be generated from the waste heat energy of the hot water X.

  The waste heat power generation apparatus 10 includes a sensor 21 (second sensor) and temperature sensors 22 and 23 (first sensor) in addition to the sensor 19, and notifies various alarms based on the measurement results. To do. Here, the alarm notified by the waste heat power generation apparatus 10 is, for example, an alarm indicating that the evaporator 11 needs to be cleaned and an alarm indicating that the condenser 13 needs to be cleaned.

  The evaporator 11 is supplied with hot water X discharged from a factory or the like and the working medium Y sent from the pump 15 through different paths, and generates heat of the working medium Y by exchanging heat inside. That is, the evaporator 11 recovers the waste heat energy of the hot water X and generates the vapor of the working medium Y. In FIG. 1, two evaporators 11 connected in parallel are illustrated, but the number of evaporators 11 may be one or three or more.

  Here, the working medium Y is a medium having a boiling point (boiling point under atmospheric pressure) of about 15 ° C., and the pressure inside the apparatus during operation is at most 1 MPa (G) (1 MPa in gauge pressure) or less. Is desirable. The reason for this is that, for example, steam can be generated from low-temperature waste heat to enable power generation using waste heat energy of low-temperature waste heat of about 100 ° C. or less, and the expansion turbine is kept low by keeping the pressure of the entire apparatus low. This is to keep the internal pressure of the generator 12 low. As such a working medium Y, for example, hydrofluoroether (HFE), fluorocarbon, fluoroketone, perfluoropolyether or the like can be used.

  The expansion turbine generator 12 includes a turbine 12a and a generator 12b, and generates three-phase AC power using the vaporized working medium Y supplied from the evaporator 11. The turbine 12 a is a rotating machine that rotates the turbine impeller by supplying the working medium Y from the evaporator 11. The generator 12b includes a rotor (rotor) coupled to the shaft of the turbine impeller and a stator (stator) provided so as to surround the outer periphery of the rotor, and the rotor is rotationally driven by the turbine 12a. To generate three-phase AC power. The three-phase AC power output from the generator 12b differs from the commercial power specification in at least one of frequency and output voltage.

  The condenser 13 is supplied with a working medium Y discharged from the expansion turbine generator 12 and a cooling medium (referred to as “cooling water Z” in the present embodiment) through separate paths, and performs heat exchange inside. The working medium Y is cooled and condensed. In FIG. 1, two condensers 13 connected in parallel are illustrated, but the number of condensers 13 may be one or three or more. The reservoir tank 14 is a tank that temporarily stores the working medium Y condensed by the condenser 13. The pump 15 pressurizes the working medium Y condensed by the condenser 13 and temporarily stored in the reservoir tank 14, and sends it to the evaporator 11.

  The AC / DC converter 16 and the DC / AC converter 17 convert the three-phase AC power generated by the generator 12b into three-phase AC power (for example, 50/60 Hz, 200 V class) that conforms to the specifications of commercial power. belongs to. The AC / DC converter 16 converts the three-phase AC power output from the generator 12 b into DC power and outputs the DC power to the DC / AC converter 17. The DC / AC converter 17 converts the DC power from the AC / DC converter 16 into three-phase AC power that conforms to the specifications of commercial power.

  The measuring device 18 measures the current flowing through the DC / AC converter 17 and measures the amount of power generation per unit time (for example, in seconds) of the expansion turbine generator 12. Here, the measurement device 18 may measure the amount of power generated per unit time of the expansion turbine generator 12 by measuring the current flowing through the AC / DC converter 16. Note that the measuring device 18 includes a noise filter so as not to pick up noise of power generation amount (for example, noise on the order of μsec).

  The sensor 19 includes a temperature sensor 19a and a pressure sensor 19b. The sensor 19 is attached to a pipe connecting the evaporator 11 and the expansion turbine generator 12, and the temperature of the working medium Y supplied to the expansion turbine generator 12 and Measure the pressure. The sensor 19 may be attached to the outlet of the working medium Y in the evaporator 11 or the inlet of the working medium Y in the expansion turbine generator 12.

  The sensor 21 includes a temperature sensor 21 a and a pressure sensor 21 b, is attached to a pipe connecting the reservoir tank 14 and the pump 15, and measures the temperature and pressure of the working medium Y supplied to the pump 15. The temperature sensor 22 is attached to a pipe that supplies the hot water X to the evaporator 11, and measures the temperature of the hot water X (the temperature of the hot water X before being distributed to each of the evaporators 11). The temperature sensor 23 is attached to a pipe that supplies the cooling water Z to the condenser 13 and measures the temperature of the cooling water Z (the temperature of the cooling water Z before being distributed to each of the condensers 13).

  The control device 20 controls the overall operation of the waste heat power generation device 10. For example, the control device 20 determines the unit of the pump 15 so that most power generation is possible from the waste heat energy of the hot water X based on the measurement results of the measurement device 18 and the sensor 19 (temperature sensor 19a and pressure sensor 19b). The number of rotations per hour (circulation amount of the working medium Y) is controlled. Specifically, the controller 20 calculates the degree of superheat based on the measurement results of the temperature sensor 19a and the pressure sensor 19b, and rotates the pump 15 per unit time so that the calculated degree of superheat becomes a predetermined target value. Control the number. However, the control device 20 performs control to reduce the number of rotations of the pump 15 per unit time when a sudden change occurs in the measurement result of the measurement device 18. This is to prevent erosion (erosion of the turbine impeller caused when the working medium Y is supplied to the expansion turbine generator 12 in a liquid state) due to a rapid temperature drop of the hot water X.

  Further, the control device 20 is configured to control the waste heat power generation device 10 based on the measurement results of the sensor 19 (temperature sensor 19a and pressure sensor 19b), sensor 21 (temperature sensor 21a and pressure sensor 21b), and temperature sensors 22 and 23. The operating state (the state of the hot water X, the working medium Y, and the cooling water Z) is simulated in the TS diagram (the diagram showing the relationship between the temperature T and the entropy S). Then, an alarm (for example, an alarm indicating that the evaporator 11 or the condenser 13 needs to be cleaned) is notified in accordance with the change state of the TS diagram.

  FIG. 2 is a block diagram illustrating a main configuration of a control device provided in the waste heat power generator according to the embodiment of the present invention. As illustrated in FIG. 2, the control device 20 includes a control unit 31, an operation state simulation unit 32, a monitoring unit 33, and a notification unit 34. The control unit 31 performs the above-described control (control of the pump 15) based on the measurement results of the measuring device 18 and the sensor 19. Based on the measurement results of the sensors 19 and 21 and the temperature sensors 22 and 23, the operation state simulation unit 32 changes the operation state of the waste heat power generation apparatus 10 (the state of the hot water X, the working medium Y, and the cooling water Z) with TS. Simulate on a diagram. Details of the TS diagram will be described later.

  The monitoring unit 33 constantly monitors the operation state (the state of the hot water X, the working medium Y, and the cooling water Z) of the waste heat power generation apparatus 10 simulated by the operation state simulation unit 32 in the TS diagram, and the waste heat power generation apparatus. It is monitored whether or not the ten operating states have changed. Specifically, the monitoring unit 33 increases the pinch temperature difference between the hot water X and the working medium Y (the minimum value of the temperature difference between the hot water X and the working medium Y in the evaporator 11) exceeding a predetermined threshold value. And whether or not the pinch temperature difference between the working medium Y and the cooling water Z (the minimum value of the temperature difference between the working medium Y and the cooling water Z in the condenser 13) has exceeded a predetermined threshold value. Monitor whether or not. And the monitoring part 33 makes the alerting | reporting part 34 alert | report the alarm according to the monitoring result.

  The notification unit 34 notifies an alarm corresponding to the monitoring result of the monitoring unit 33. The notification unit 34 includes, for example, a display device such as a liquid crystal display device, a sound generation device such as a speaker, a wireless transmission device that transmits a radio signal, and the like. Or it displays on a display apparatus with a symbol, and it produces sound from a sound production apparatus, or transmits with a radio signal from a wireless transmission apparatus.

  FIG. 3 is a diagram illustrating an example of a TS diagram used in the waste heat power generator according to the embodiment of the present invention. As shown in FIG. 3, the TS diagram is a diagram with the temperature T on the vertical axis and the entropy S on the horizontal axis, and the operating state of the waste heat power generation apparatus 10 (hot water X, working medium Y, and It is a diagram in which the state of cooling water Z) is simulated. This TS diagram is created by the operation state simulation unit 32 described above.

  In FIG. 3, the line to which the symbol L0 is attached is a saturated vapor pressure line. In FIG. 3, lines denoted by reference signs L11 and L12 are lines indicating the state of the hot water X (state line of hot water X), and lines denoted by reference numerals L21 and L22 are states of the working medium Y. (Line of the working medium Y), and the lines with reference numerals L31 and L32 are lines indicating the state of the cooling water Z (state line of the cooling water Z).

  The left region R1 delimited by the saturated vapor pressure line L0 is a region where the working medium Y is in a liquid phase, and the right region R2 delimited by the saturated vapor pressure line L0 is a gas phase where the working medium Y is in a gas phase. It is an area. The central region R3 delimited by the saturated vapor pressure line L0 is a region where the working medium Y is in a state where the gas phase and the liquid phase are mixed.

  In FIG. 3, the state lines indicated by the solid lines (the state line L11 for the hot water X, the state line L21 for the working medium Y, and the state line L31 for the cooling water Z) are contaminated in the evaporator 11 and the condenser 13. It is a state line when there is not. On the other hand, the state lines (the state line L12 of the hot water X, the state line L22 of the working medium Y, and the state line L32 of the cooling water Z) shown by broken lines are when the evaporator 11 and the condenser 13 are contaminated Is the state line.

  The right end portions (end portions in the region R2) Q11 of the hot water X state lines L11 and L12 indicate the state of the hot water X flowing into the evaporator 11, and the left end portions (regions) of the hot water X state lines L11 and L12. An end Q12 in R1 shows the state of the hot water X discharged from the evaporator 11. Further, the left end portions (end portions in the region R1) Q31 of the state lines L31 and L32 of the cooling water Z indicate the state of the cooling water Z flowing into the condenser 13, and the state lines L31 and L32 of the cooling water Z are shown. The right end portion (end portion in the region R3) Q32 of FIG. 2 shows the state of the cooling water Z discharged from the condenser 13.

  Referring to FIG. 3, the state line L11 of the hot water X has a larger inclination than the state line L12 of the hot water X, and the state line L31 of the cooling water Z has a larger inclination than the state line L32 of the cooling water Z. I understand. Further, it can be seen that the area surrounded by the state line L21 of the working medium Y is larger than the area surrounded by the state line L22 of the working medium Y. This is because the heat exchange between the hot water X and the working medium Y in the evaporator 11 and the heat exchange between the working medium Y and the cooling water Z in the condenser 13 cause contamination of the evaporator 11 and the condenser 13. This is because the case where the evaporator 11 and the condenser 13 are not contaminated is performed better than the case where it is present.

  3, the pinch temperature difference ΔT12 (the pinch temperature difference between the hot water X and the working medium Y when the evaporator 11 is contaminated) is the pinch temperature difference ΔT11 (the evaporator 11 is contaminated). It can be seen that the difference is greater than the pinch temperature difference between the hot water X and the working medium Y in the case where the temperature is not present. Similarly, the pinch temperature difference ΔT22 (pinch temperature difference between the working medium Y and the cooling water Z when the condenser 13 is contaminated) is equal to the pinch temperature difference ΔT21 (when the condenser 13 is not contaminated). It can be seen that this is greater than the pinch temperature difference between the working medium Y and the cooling water Z.

  Thus, the pinch temperature difference between the hot water X and the working medium Y increases according to the contamination of the evaporator 11, and the pinch temperature difference between the working medium Y and the cooling water Z corresponds to the contamination of the condenser 13. There is a characteristic of becoming larger. In the present embodiment, by utilizing such a pinch temperature difference characteristic, an appropriate cleaning timing of the evaporator 11 and the condenser 13 is detected with high reliability without causing an increase in cost.

  Next, the operation of the waste heat power generator 10 having the above configuration will be described. In the waste heat power generation apparatus 10 of the present embodiment, the working medium Y is converted into the evaporator 11 (two evaporators 11) → the expansion turbine generator 12 → the condenser 13 (two condensers 13) → the reservoir tank 14 → the pump 15. → Power generation in the expansion turbine generator 12 is performed by changing the state of the working medium Y to liquid and gas while circulating in the order of the evaporator 11 (two evaporators 11).

  That is, after the working medium Y evaporated by the heat of the hot water X in the evaporator 11 is supplied to the expansion turbine generator 12, is condensed by the cooling water Z in the condenser 13, and is temporarily stored in the reservoir tank 14. Then, it is sent again to the evaporator 11 through the pump 15. In the process of such a cyclic state change of the working medium Y, the expansion turbine generator 12 is driven by the working medium Y to generate electric power. The three-phase AC power generated by the expansion turbine generator 12 is converted into three-phase AC power that conforms to the specifications of commercial power by the AC / DC converter 16 and the DC / AC converter 17 and supplied to the outside. The

  While the above operation is performed, the current flowing through the DC / AC converter 17 (or the current flowing through the AC / DC converter 16) is measured by the measuring device 18, and the unit time of the expansion turbine generator 12 ( For example, the power generation amount per second) is measured by the measuring device 18. Further, the temperature and pressure of the working medium Y supplied to the expansion turbine generator 12 are measured by the temperature sensor 19a and the pressure sensor 19b, respectively.

  Then, the degree of superheat is calculated based on the measurement results of the temperature sensor 19a and the pressure sensor 19b, and control is performed to vary the rotation speed per unit time of the pump 15 so that the calculated degree of superheat becomes a predetermined target value. This is performed by the control unit 31 of the apparatus 20. When a sudden change occurs in the measurement result of the measuring device 18, the control unit 31 of the control device 20 performs control for reducing the rotational speed per unit time of the pump 15 in order to prevent the erosion described above. Done.

  While the above-described control is performed, the temperature and pressure of the working medium Y supplied to the pump 15 are measured by the temperature sensor 21a and the pressure sensor 21b, respectively, and the hot water X supplied to the evaporator 11 is measured. The temperature and the temperature of the cooling water Z supplied to the condenser 13 are measured by the temperature sensors 22 and 23, respectively. 3 is based on the measurement results of the temperature sensor 21a and the pressure sensor 21b, the measurement results of the temperature sensors 22 and 23, and the measurement results of the temperature sensor 19a and the pressure sensor 19b described above. 20 operation state simulation units 32 are created and sequentially updated.

  When the operation state simulation unit 32 generates the TS diagram, the monitoring unit 33 constantly monitors whether or not the operation state of the waste heat power generator 10 has changed. Specifically, whether or not the pinch temperature difference between the hot water X and the working medium Y (for example, the pinch temperature difference ΔT11 in FIG. 3) has exceeded a predetermined threshold, and the working medium Y and the cooling water. The monitoring unit 33 monitors whether or not the pinch temperature difference from Z (for example, the pinch temperature difference ΔT21 in FIG. 3) exceeds a predetermined threshold.

  When the pinch temperature difference between the hot water X and the working medium Y exceeds the threshold value, the monitoring unit 33 controls the notification unit 34 to notify an alarm indicating that the evaporator 11 needs to be cleaned. . When the pinch temperature difference between the working medium Y and the cooling water Z exceeds the threshold value, the notification unit 34 is controlled by the monitoring unit 33 and an alarm indicating that the condenser 13 needs to be cleaned is notified. The

  As described above, in the present embodiment, based on the measurement results of the sensors 19 and 21 and the temperature sensors 22 and 23, the states of the hot water X, the working medium Y, and the cooling water Z are represented in the TS diagram, An alarm is notified in accordance with the change situation. As a result, it is possible to detect whether or not the evaporator 11 and the condenser 13 need to be cleaned without adding a sight glass or a differential pressure gauge. It is possible to detect a proper cleaning timing.

  In the embodiment described above, the evaporator 11 and the condenser 13 need to be cleaned in accordance with the change in the pinch temperature difference between the hot water X and the working medium Y and the pinch temperature difference between the working medium Y and the cooling water Z. It was detected whether or not. However, whether or not the evaporator 11 and the condenser 13 need to be cleaned is detected according to the approach temperature between the hot water X and the working medium Y and the change state of the approach temperature between the working medium Y and the cooling water Z. You may do it.

  FIG. 4 is a diagram for explaining the approach temperature. The approach temperature generally refers to the difference between the high temperature side inlet temperature and the low temperature side outlet temperature. The approach temperature between the hot water X and the working medium Y is a temperature difference between the hot water X flowing into the evaporator 11 and the working medium Y discharged from the evaporator 11 (see approach temperatures ΔT31 and ΔT32 in FIG. 4). The approach temperature between the working medium Y and the cooling water Z is a temperature difference between the working medium Y flowing into the condenser 13 and the cooling water Z discharged from the condenser 13 (approach temperature ΔT41, FIG. 4). See ΔT42).

  Here, referring to FIG. 4, the approach temperature ΔT32 (the approach temperature between the hot water X and the working medium Y when the evaporator 11 is contaminated) is the approach temperature ΔT31 (the evaporator 11 is not contaminated). It can be seen that the temperature is higher than the approach temperature of the hot water X and the working medium Y in the case. The approach temperature ΔT42 (the approach temperature between the working medium Y and the cooling water Z when the condenser 13 is contaminated) is the approach temperature ΔT41 (the working medium Y when the condenser 13 is not contaminated). It turns out that it becomes larger than approach temperature with the cooling water Z).

  As described above, the approach temperature between the hot water X and the working medium Y increases according to the contamination of the evaporator 11 as well as the pinch temperature difference between the hot water X and the working medium Y, and the working medium Y and the cooling water Z Similarly to the pinch temperature difference between the working medium Y and the cooling water Z, the approach temperature has a characteristic of increasing according to the contamination of the condenser 13. Therefore, even when the approach temperature is used, as in the case of using the pinch temperature difference, it is possible to detect the proper cleaning timing of the evaporator 11 and the condenser 13 with high reliability without causing an increase in cost. .

  Further, in consideration of both the above-described change state of the pinch temperature difference and the change state of the approach temperature, an alarm corresponding to these change states may be generated. Here, the pinch temperature difference and the approach temperature are not limited to when the evaporator 11 and the condenser 13 are contaminated, but when the turbine impeller provided in the turbine 12a is deteriorated, or the blade provided in the pump 15 is used. It also changes when deterioration (not shown) occurs. However, the state of change in the pinch temperature difference and the approach temperature is different between when the evaporator 11 and the condenser 13 are contaminated and when the turbine impeller or the like is deteriorated.

For this reason, according to the pinch temperature difference and the change state of approach temperature, you may make it alert | report as follows.
・ When both the pinch temperature difference between hot water X and working medium Y and the approach temperature increase → An alarm indicating that the evaporator 11 needs to be cleaned is notified. ・ Pinch temperature difference between working medium Y and cooling water Z When both the approach temperature and the approach temperature have increased, an alarm indicating that the condenser 13 needs to be cleaned is notified. Only the pinch temperature difference between the hot water X and the working medium Y or the pinch temperature difference between the working medium Y and the cooling medium. → Increase alarm indicating that abnormality has occurred in expansion turbine generator 12 or pump 15

  As mentioned above, although the waste heat power generator by one Embodiment of this invention was demonstrated, this invention is not restrict | limited to the said embodiment, It can change freely within the scope of the present invention. For example, in the above embodiment, the waste heat energy that has become the hot water X is recovered as electric energy, but the present invention is not limited to this, and for example, waste gas may be used as a heat source. Further, the heat source is not limited to waste heat such as waste gas or waste hot water. Further, as the above-described expansion turbine generator 12, a radial turbine generator such as a centrifugal expansion turbine generator or a mixed flow expansion turbine generator may be used.

DESCRIPTION OF SYMBOLS 10 ... Waste heat power generation device, 11 ... Evaporator, 12 ... Expansion turbine generator, 13 ... Condenser, 15 ... Pump, 19 ... Sensor, 20 ... Control device, 21 ... Sensor, 22 ... Temperature sensor, 23 ... Temperature sensor , X ... warm water, Y ... working medium, Z ... cooling water, ΔT11 ... pinch temperature difference, ΔT12 ... pinch temperature difference, ΔT21 ... pinch temperature difference, ΔT22 ... pinch temperature difference, ΔT31 ... approach temperature, ΔT32 ... approach temperature, ΔT41 ... Approach temperature, ΔT42 ... Approach temperature

Claims (8)

An evaporator that evaporates the working medium by exchanging heat between the waste heat medium and the working medium, a turbine generator that generates electric power by supplying the working medium from the evaporator, and discharged from the turbine generator A waste heat power generator comprising: a condenser that performs heat exchange between the working medium and a cooling medium to condense the working medium; and a pump that sends the working medium condensed in the condenser toward the evaporator. Because
A first sensor having a sensor for measuring the temperature of the waste heat medium and a sensor for measuring the temperature of the cooling medium;
A second sensor having a sensor for measuring the temperature of the working medium and a sensor for measuring the pressure of the working medium ;
Based on the measurement results of the first and second sensors, the states of the waste heat medium, the working medium, and the cooling medium are represented in a TS diagram, and an alarm is notified according to the change state of the TS diagram. A waste heat power generator comprising: a control device.   The control device notifies an alarm indicating that the evaporator needs to be cleaned according to a change state of a pinch temperature difference between the waste heat medium and the working medium, and the working medium and the cooling medium The waste heat power generator according to claim 1, wherein an alarm indicating that the condenser needs to be cleaned is notified according to a change state of a pinch temperature difference.   The control device issues an alarm indicating that the evaporator needs to be cleaned according to a change in approach temperature between the waste heat medium and the working medium, and approaches the working medium and the cooling medium. The waste heat power generator according to claim 1, wherein an alarm indicating that the condenser needs to be cleaned is notified according to a change in temperature.   The control device notifies an alarm indicating that the evaporator needs to be cleaned when both the pinch temperature difference between the waste heat medium and the working medium and the approach temperature increase, and the working medium and When both the pinch temperature difference with the cooling medium and the approach temperature increase, an alarm indicating that the condenser needs to be cleaned is notified, and the pinch temperature difference between the waste heat medium and the working medium or The waste according to claim 1, wherein when only the pinch temperature difference between the working medium and the cooling medium increases, an alarm indicating that an abnormality has occurred in the turbine generator or the pump is notified. Thermoelectric generator. A heat exchanger to which a waste heat medium and a working medium are supplied;
A turbine generator connected to the heat exchanger and supplied with the working medium from the heat exchanger;
A condenser connected to the turbine generator and supplied with a cooling medium and the working medium from the turbine generator;
Have
A waste heat power generator in which the working medium output from the condenser is supplied to the heat exchanger,
The waste heat power generator further includes
A waste heat power generation apparatus further comprising a control device that outputs an alarm based on a change in the relationship between the temperature and entropy of each of the waste heat medium, the working medium, and the cooling medium.   The control device issues an alarm indicating that the heat exchanger needs to be cleaned based on a change in a pinch temperature difference between the waste heat medium and the working medium, and pinches the working medium and the cooling medium. The waste heat power generator according to claim 5, wherein an alarm indicating that the condenser needs to be cleaned is notified based on a change in temperature difference.   The control device issues an alarm indicating that the heat exchanger needs to be cleaned based on a change in approach temperature between the waste heat medium and the working medium, and approaches the approach temperature between the working medium and the cooling medium. The waste heat power generator according to claim 5, wherein an alarm indicating that the condenser needs to be cleaned is notified based on a change in the temperature.   The control device issues an alarm indicating that the heat exchanger needs to be cleaned when both the pinch temperature difference between the waste heat medium and the working medium and the approach temperature increase, and the working medium And an alarm indicating that the condenser needs to be cleaned when both the pinch temperature difference and the approach temperature of the cooling medium increase, and the pinch temperature difference between the waste heat medium and the working medium Alternatively, when only a pinch temperature difference between the working medium and the cooling medium increases, an alarm indicating that an abnormality has occurred in the turbine generator is notified. apparatus.

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