JP2016161248A - Heat pump type steam generation device and operation method of heat pump type steam generation device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a heat pump type steam generation device and an operation method of the heat pump type steam generation device capable of corresponding to the change of a state of hot water which becomes a heat source, and capable of continuing an operation stably.SOLUTION: A heat pump type steam generation device 10 includes: a heat pump part 16 for connecting an exhaust heat recovery device 20, a compressor 22, a condenser 24 and a throttle expander 26 in an annular manner and for circulating a refrigerant; a hot water supply part 18 for supplying hot water to the exhaust heat recovery device 20 and discharging it; and a steam generation part 14 for supplying heated water to the condenser 24 and for generating steam by heating the heated water by the refrigerant. Furthermore, it includes: a heat amount monitoring unit 44 for monitoring a heat amount of the hot water supplied to the exhaust heat recovery device 20 by the hot water supply part 18; and a control unit 19 for controlling at least one circulation amount out of the hot water and the refrigerant, based on the monitoring result of the heat amount monitoring unit 44.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a heat pump steam generator that recovers exhaust heat from factory wastewater or the like and generates steam, and an operation method of the heat pump steam generator.

As one of the steam generators, there is a heat pump steam generator using a heat pump device. The heat pump type steam generator recovers waste heat from waste water (hot water) such as factory waste water or used cooling water to generate steam. In other words, the heat pump type steam generator causes the evaporator of the heat pump device to function as an exhaust heat recovery unit, where exhaust heat is recovered from the exhaust hot water into a refrigerant, and the recovered water is used to collect the heated water with a condenser. Since steam is generated by heating, there is an advantage that the running cost and CO ₂ emission amount can be reduced as compared with a combustion system steam generator that generates steam using boiler equipment or the like.

  In such a heat pump type steam generator, the temperature and pressure of the refrigerant on the suction side and discharge side of the compressor are measured, and the degree of superheat on the suction side and discharge side of the compressor is always kept at a certain value or more. In general, the heat pump apparatus is controlled. Moreover, in order to respond to changes in the use load of steam on the use side, a heat pump steam generation apparatus that controls a compressor based on the pressure of generated steam has also been proposed (see Patent Document 1).

JP 2011-257122 A

  As described above, since the heat pump steam generator uses waste water such as factory waste water as a heat source, for example, when the supply amount or temperature of the waste water is significantly lower than normal, the heat pump device is discharged. There is a possibility that heat cannot be sufficiently recovered from the heat recovery device. If it does so, a refrigerant | coolant cannot evaporate with an exhaust heat recovery device, and it will be in the state called the liquid back | bag in which a liquid phase refrigerant | coolant is suck | inhaled by a compressor, and will cause damage to a compressor in the worst case.

  In order to avoid such a breakage of the compressor, a method of monitoring the superheat degree using the superheat degree control described above and, for example, emergency stopping the heat pump device (compressor) when the superheat degree on the discharge side becomes zero. There is also. However, once the compressor is stopped, it is necessary to wait until the temperature and pressure in the refrigerant circuit become equal, and a considerable time is required until restart. As a result, even when the supply amount and temperature of the exhaust hot water are subsequently recovered, a certain amount of time is required until the steam is stably generated, which may affect the facility using the steam.

  The present invention has been made in consideration of the above-described problems of the prior art, can cope with a change in the state of hot water serving as a heat source, and a heat pump type steam generator capable of stably continuing operation and It aims at providing the operating method of this heat pump type steam generating device.

  A heat pump steam generator according to the present invention includes an exhaust heat recovery unit that recovers heat from hot water and heats the refrigerant, a compressor that compresses the refrigerant that has exited the exhaust heat recovery unit, and a refrigerant that is compressed by the compressor A condenser that cools the refrigerant, a throttle expander that expands the refrigerant discharged from the condenser, and a heat pump that circulates the refrigerant, and a hot water supply unit that supplies the hot water to the exhaust heat recovery unit and discharges it And a steam generation unit that supplies heated water to the condenser and heats the heated water with the refrigerant to generate steam, wherein the hot water supply unit A calorific value monitoring unit that monitors the calorific value of hot water supplied to the heat recovery unit; and a control unit that controls a flow rate of at least one of the warm water and the refrigerant based on a monitoring result of the calorific value monitoring unit. Features.

  In addition, the operation method of the heat pump steam generator according to the present invention is an operation of the heat pump steam generator that recovers heat from hot water using a heat pump cycle and transmits the recovered heat to the water to be heated to generate steam. The method is characterized in that the amount of heat of the hot water is monitored, and the flow amount of at least one of the hot water and the refrigerant flowing through the heat pump cycle is controlled based on the monitoring result.

  According to such a configuration and method, when the state of the hot water serving as the heat source of the heat pump unit (heat pump cycle) changes, the heat pump based on the lack of heat of the hot water by controlling the flow rate of at least one of the hot water and the refrigerant. The emergency stop of the operation of the part can be avoided as much as possible. For this reason, operation | movement of an apparatus can be continued stably and a vapor | steam can be stably supplied with respect to a vapor | steam utilization equipment.

  In the above configuration, the control unit is configured to control a flow rate of hot water supplied to the exhaust heat recovery unit by the hot water supply unit so that a heat amount of the hot water monitored by the heat amount monitoring unit becomes a set heat amount. May be. Moreover, in the said method, you may control the flow volume of the warm water supplied to the said waste heat recovery device so that the calorie | heat amount of the said warm water monitored may become setting heat amount. Thereby, the calorie | heat amount of the warm water supplied to a waste heat recovery device can be maintained at a setting calorie | heat amount.

  In the above configuration, the hot water supply unit is provided with a calorific value measuring means for measuring the amount of heat of hot water supplied to the exhaust heat recovery device, and a hot water flow rate adjusting means for adjusting the amount of hot water flowing through the exhaust heat recovery device. And the controller controls the flow rate of the hot water by controlling the flow rate of the hot water by driving the hot water flow rate adjusting means so that the heat quantity of the hot water measured by the calorie measuring means becomes a preset heat quantity. The structure which controls calorie | heat amount to the said setting calorie | heat amount may be sufficient.

  In the above configuration, the calorific value measuring unit is a temperature measuring unit that measures a temperature of hot water supplied to the exhaust heat recovery unit, and the control unit is configured to measure the temperature of the hot water measured by the temperature measuring unit and the hot water. Based on the flow rate of the hot water sent out by the flow rate adjusting means, the flow rate of the hot water is controlled by driving the hot water flow rate adjusting means so that the heat amount of the hot water supplied to the exhaust heat recovery device becomes a preset heat amount. Thus, the configuration may be such that the amount of heat of the hot water is controlled to the set amount of heat.

  The said structure WHEREIN: The said control part controls so that the refrigerant | coolant flow rate in the said heat pump part may be reduced rather than a normal operation mode, when the heat quantity of the said hot water monitored by the said heat quantity monitoring part becomes less than predetermined value. The structure which performs standby operation mode may be sufficient. Moreover, in the said method, when the calorie | heat amount of the said warm water monitored becomes less than predetermined value, you may switch to the standby operation mode which controls so that the said refrigerant | coolant flow volume may be reduced rather than normal operation mode. As a result, when the amount of heat of the hot water that is the heat source of the heat pump unit (heat pump cycle) is insufficient, the heat pump unit is shifted to the standby operation mode and the refrigerant flow rate is reduced from that in the normal operation mode. The operation of the heat pump unit can be continued while the amount of heat of the hot water to be supplied is insufficient, and the emergency stop can be avoided as much as possible. And since it can transfer to normal operation mode rapidly after the calorie | heat amount of hot water recovers, the time for which the production | generation of a steam | stagnation can be suppressed to the minimum.

  The said structure WHEREIN: The structure which determines whether the said calorie | heat amount is less than predetermined value based on the flow volume of the warm water supplied to the said waste heat recovery device may be sufficient as the said calorie | heat amount monitoring part.

  In the above configuration, the heat quantity monitoring unit is configured such that the heat quantity is less than a predetermined value based on a temperature difference between the temperature of the hot water supplied to the exhaust heat recovery device and the temperature of the hot water discharged from the exhaust heat recovery device. The structure which determines whether there exists may be sufficient.

  The said structure WHEREIN: The said hot water supply part is provided with the pump which sends out the said warm water to the said waste heat recovery device, The said heat quantity monitoring part is based on the drive rotation speed of the said pump, and the said heat quantity is less than predetermined value It may be configured to determine whether or not.

  The said structure WHEREIN: The structure which determines whether the said calorie | heat amount is less than predetermined value based on the temperature of the hot water supplied to the said exhaust heat recovery device may be sufficient as the said calorie | heat amount monitoring part.

  In the above configuration, when the heat quantity is determined to be greater than or equal to a predetermined value by the heat quantity monitoring unit during the standby operation mode, the control unit increases the refrigerant flow rate in the heat pump unit and enters the normal operation mode. By performing the return control, it is possible to quickly shift from the standby operation mode to the normal operation mode after recovering the heat quantity of the hot water.

  The said structure WHEREIN: The structure which performs the same control pattern as the time of starting of the said heat pump part may be sufficient when the said control part returns from the said standby operation mode to the said normal operation mode. As a result, when returning from the standby operation mode to the normal operation mode, the drive rotational speed of the compressor and the opening of the throttle expander are prevented from increasing suddenly, and liquid phase refrigerant is sucked into the compressor. Can be avoided.

  In the above-described configuration, the control unit includes a degree of superheat on the discharge side or suction side of the compressor, a temperature of hot water supplied to the exhaust heat recovery device, and a temperature of hot water discharged from the exhaust heat recovery device. When the difference or the temperature or the flow rate of the hot water supplied to the exhaust heat recovery device is less than a predetermined value for a certain time or more, the operation of the heat pump unit may be stopped.

  In the above configuration, the control unit controls a flow rate of hot water supplied from the hot water supply unit to the exhaust heat recovery unit so that a heat amount of the hot water monitored by the heat amount monitoring unit becomes a set heat amount, and When the amount of heat of the hot water supplied to the exhaust heat recovery device becomes less than a predetermined value, the standby operation mode in which control is performed to reduce the refrigerant flow rate in the heat pump unit may be executed. Further, in the above method, the flow rate of the hot water supplied to the exhaust heat recovery device is controlled so that the monitored heat amount of the hot water becomes a set heat amount, and the heat amount of the hot water supplied to the exhaust heat recovery device is When it becomes less than a predetermined value, it may be switched to a standby operation mode in which control for reducing the refrigerant flow rate is performed. As a result, while maintaining the amount of hot water supplied to the exhaust heat recovery unit at the set amount of heat, if it becomes difficult to maintain due to the influence of the state of the hot water supply source, the exhaust heat is transferred to the standby operation mode. The operation of the heat pump unit can be continued while the amount of heat of the hot water supplied to the recovery device is insufficient, and the emergency stop can be avoided as much as possible.

  According to the present invention, when the state of the hot water serving as the heat source of the heat pump unit changes, the heat pump unit based on the lack of heat of the hot water supplied to the exhaust heat recovery device by controlling the flow rate of at least one of the hot water and the refrigerant The emergency stop of the operation can be avoided as much as possible, and the operation of the apparatus can be continued stably.

FIG. 1 is a configuration diagram of a heat pump type steam generator according to a first embodiment of the present invention. FIG. 2 is a flowchart showing the procedure of the operation method of the heat pump steam generator according to the first embodiment. FIG. 3 is a flowchart showing a procedure of another operation method of the heat pump type steam generator according to the first embodiment. FIG. 4 is a configuration diagram of a heat pump steam generator according to the second embodiment of the present invention. FIG. 5 is a flowchart showing the procedure of the operation method of the heat pump steam generator according to the second embodiment.

  DESCRIPTION OF EMBODIMENTS Hereinafter, preferred embodiments of a heat pump steam generator and an operation method thereof according to the present invention will be described in detail with reference to the accompanying drawings.

1. Description of Heat Pump Steam Generating Device According to First Embodiment FIG. 1 is a configuration diagram of a heat pump steam generating device 10 according to the first embodiment of the present invention. The heat pump steam generator 10 is a system that recovers exhaust heat from warm water (exhaust warm water) such as factory effluent and used cooling water, and generates steam using the recovered exhaust heat, and the generated steam is dried. It is sent to an external steam utilization facility 12 such as a device or a sterilizer.

  As shown in FIG. 1, the heat pump type steam generation device 10 generates water vapor by evaporating water, collects heat from the hot water, and recovers heat from the hot water. The heat pump part 16 supplied as a heat source for the vapor | steam production | generation, the hot water supply part 18 which supplies the warm water used as the heat source of the heat pump part 16, and the control part 19 are provided.

  The heat pump unit 16 is compressed by the exhaust heat recovery device (evaporator) 20 that recovers heat from the hot water and heats the refrigerant, the compressor 22 that compresses the refrigerant that exits the exhaust heat recovery device 20, and the compressor 22. A refrigerating cycle device (heat pump cycle) in which a condenser 24 that dissipates heat and condenses the refrigerant and a throttle expander 26 that expands the refrigerant that has exited the condenser 24 are connected in an annular manner through a refrigerant pipe in order to circulate the refrigerant. is there.

  The refrigerant that has been compressed by the compressor 22 to high temperature and high pressure is cooled and condensed by exchanging heat with water (heated water) circulating through the steam generation unit 14 in the condenser 24. The refrigerant that has exited the condenser 24 is expanded by a throttle expander 26 that is an electronic expansion valve. The exhaust heat recovery unit 20 absorbs heat from the hot water flowing through the hot water pipe 28 of the hot water supply unit 18 and evaporates. Return to.

  Under the control of the control unit 19, for example, during normal operation, the heat pump unit 16 adjusts the drive rotation speed of the compressor 22 and the opening of the expansion expander 26 so that the refrigerant in the compression stroke has a predetermined degree of superheat. It is operated with superheat control (normal operation mode). This superheat degree control is executed based on detection values (discharge pressure and discharge temperature) of a pressure sensor and a temperature sensor (not shown) provided on the discharge side of the compressor 22, for example.

  The steam generation unit 14 includes a gas-liquid separator 30 that stores water inside the container, a condenser 24 that functions as a steam generator that evaporates water using a refrigerant circulating in the heat pump unit 16 as a heat source, and a gas-liquid separator 30. And a steam compressor 32 that compresses and raises the pressure of the water vapor sent out from the air. The gas-liquid separator 30 and the condenser 24 are connected by a circulation pipe 34 that connects the lower wall of the gas-liquid separator 30 to the upper wall of the gas-liquid separator 30 via the condenser 24.

  Water is supplied from a water supply pipe 35 connected to a circulation pipe 34 connected to the lower wall of the gas-liquid separator 30. Under the control of the control unit 19, the feed water pump 36 is configured so that the mass flow rate Q1 of the supply water is equal to the mass flow rate Q2 of the steam taken out from the steam delivery pipe 38 and the mass flow rate Q3 of the circulating water introduced into the circulation pipe 34. In many cases, the drive rotational speed is controlled so as to be the total amount (Q2 + Q3). Further, based on the detection value (water level) of a water level sensor (not shown) that measures the water level of the water stored in the gas-liquid separator 30, the drive rotation speed may be controlled, or both controls may be used in combination. .

  Connected to the upper end wall of the gas-liquid separator 30 is a steam delivery pipe 38 for sending the steam generated by the heat pump steam generator 10 to the external steam utilization equipment 12 side. The two-phase flow in which the water and the water vapor exiting the condenser 24 are mixed is introduced into the gas-liquid separator 30 from the circulation pipe 34 on the outlet side of the condenser 24, and the water vapor after the water is separated here. It is sent out to the steam delivery pipe 38.

  The hot water supply unit 18 supplies hot water to the exhaust heat recovery device 20 and discharges hot water (drainage) discharged from the exhaust heat recovery device 20, and a hot water piping 28 on the upstream side of the exhaust heat recovery device 20. A hot water pump (pump) 40 provided, and a heat flow meter 42 provided in a hot water pipe 28 between the hot water pump 40 and the exhaust heat recovery device 20 are provided.

  The heat flow meter 42 is a measuring device that measures a heat flow rate (W (= J / s)), which is a heat amount (J) circulated per unit time of hot water supplied to the exhaust heat recovery device 20 through the hot water pipe 28. is there. The measurement value in the heat flow meter 42 is transmitted to the heat quantity monitoring unit 44 of the control unit 19 and is calculated as the heat flow of hot water. The heat quantity monitoring unit 44 controls the drive rotation speed of the hot water pump 40 in order to control the heat quantity (J) of the hot water supplied to the exhaust heat recovery unit 20 based on the measured value of the heat flow of the hot water by the heat flow meter 42. A predetermined control signal is output to the inverter 46. The hot water that has passed through the exhaust heat recovery device 20 is discharged out of the system by the hot water pipe 28 on the downstream side of the exhaust heat recovery device 20, or is cascaded by another exhaust heat recovery device.

  The warm water supplied to the exhaust heat recovery unit 20 by the warm water supply unit 18 is, for example, water having a temperature higher than room temperature (exhaust warm water), and for example, by supplying warm water having a temperature of 60 ° C. or higher to the exhaust heat recovery unit 20 The part 16 can be stably operated normally. The minimum temperature and the optimum temperature of the hot water are appropriately determined according to the type of the compressor 22 and other equipment configurations.

  The control unit 19 is a controller that comprehensively controls the heat pump steam generation device 10, and performs operation control of the steam generation unit 14, the heat pump unit 16, and the hot water supply unit 18. The heat quantity monitoring unit 44 is provided as a function of the control unit 19. The heat quantity monitoring unit 44 monitors the heat quantity of the hot water supplied to the exhaust heat recovery unit 20 through the hot water pipe 28, and based on the monitoring result, the circulation amount of the hot water to the exhaust heat recovery unit 20 by the hot water supply unit 18 and the heat pump The flow rate of the refrigerant in the unit 16 is controlled. The heat quantity monitoring unit 44 may be provided separately from the control unit 19.

  Next, operation | movement of the heat pump type steam generation apparatus 10 which concerns on this embodiment is demonstrated with reference to the flowchart of FIG.

  First, when the operation of the heat pump type steam generator 10 is started and the start-up process is started (step S1 in FIG. 2), the operation of the compressor 22, the steam compressor 32, the feed water pump 36, and the hot water pump 40 is started. Is done.

  In this startup process, the control unit 19 controls the operation of the heat pump unit 16 with the control pattern of the startup operation mode. In the start-up operation mode, for example, the superheat degree on the suction side of the compressor 22 does not become zero based on detection values (suction pressure and suction temperature) of a pressure sensor and a temperature sensor (not shown) provided on the suction side of the compressor 22. Further, while adjusting the drive speed of the compressor 22 and the opening of the throttle expander 26, the drive speed and the opening are gradually increased to lead to a rated operation state.

  When the superheat degree on the discharge side of the compressor 22 becomes equal to or greater than a predetermined value during the startup operation mode, the control unit 19 switches the heat pump unit 16 to the control pattern of the normal operation mode (steady operation mode) to perform the startup process. Ends. In the normal operation mode, for example, based on the discharge pressure and discharge temperature of the compressor 22, the drive rotation speed of the compressor 22 and the opening degree of the throttle expander 26 are set so that the degree of superheat on the discharge side of the compressor 22 becomes a predetermined value or more. Adjust. As a result, the water to be heated that circulates in the circulation pipe 34 evaporates in the condenser 24 to become water vapor, is introduced from the gas-liquid separator 30 into the steam delivery pipe 38, is pressurized by the steam compressor 32, It is sent out to the steam utilization facility 12.

  When the normal operation mode is started, the heat quantity monitoring unit 44 of the control unit 19 starts monitoring the heat quantity of the hot water supplied to the exhaust heat recovery unit 20 by acquiring the measurement value of the heat flow meter 42 at any time ( Step S2). Note that the heat quantity monitoring of the hot water may be started during the startup operation mode. And when the calorie | heat amount of the hot water supplied to the exhaust heat recovery device 20 exists in the range of the setting calorie | heat amount, heat amount monitoring is continued (Yes of step S3). Here, the set heat amount is, for example, an amount of heat within a range that allows the heat pump unit 16 to be stably operated in the normal operation mode without deficient in the amount of heat recovered from the hot water in the heat pump unit 16. In other words, the set heat amount is an amount of heat that can maintain the degree of superheat on the discharge side of the compressor 22 at a predetermined value or higher by the amount of heat recovered from the hot water by the heat pump unit 16.

  On the other hand, in step S3, when the heat quantity of the hot water supplied to the exhaust heat recovery device 20 is out of the set heat quantity range (No in step S3), step S4 is executed. The reason why the amount of heat of the hot water falls outside the range of the set amount of heat is that, for example, when the temperature of the hot water is greatly reduced, the flow rate of hot water introduced into the hot water pump 40 is reduced, so that a sufficient flow of hot water cannot be sent out Or when the temperature or flow rate of hot water is excessively increased and the amount of heat is increased.

  In step S4, the hot water pump 40 is controlled so that the flow rate corresponds to the change in the amount of heat of hot water from the monitoring result in step S3. For example, when it is determined from the monitoring result of step S3 that the amount of heat of the hot water has decreased, the heat amount monitoring unit 44 controls the inverter 46 by PID control or the like to increase the drive rotational speed of the hot water pump 40, and the exhaust heat recovery unit 20 The amount of heat is increased by increasing the flow rate of hot water supplied to the. For example, when it is determined from the monitoring result in step S3 that the amount of heat of the hot water has increased, the heat amount monitoring unit 44 controls the inverter 46 by PID control or the like, reduces the drive rotation speed of the hot water pump 40, and recovers exhaust heat. The amount of heat is reduced by reducing the flow rate of the hot water supplied to the vessel 20. In this way, the heat quantity monitoring unit 44 controls the supply flow rate of the hot water so that the heat quantity of the hot water supplied to the exhaust heat recovery device 20 is within the set heat quantity range. The hot water flow rate adjusting means for adjusting the amount of hot water flowing through the exhaust heat recovery device 20 may be other than the hot water pump 40. For example, an adjustment valve (flow control valve) or the like that can control the hot water flow rate with its opening degree. Can be mentioned.

  Note that the monitoring of the amount of heat supplied to the exhaust heat recovery unit 20 in step S3 can be performed by a method other than the method using the heat flow meter 42. For example, as shown in FIG. 1, there is a method of providing a temperature sensor 41 for measuring the temperature of hot water in the hot water pipe 28 between the hot water pump 40 and the exhaust heat recovery device 20. That is, since the heat quantity monitoring unit 44 grasps the drive rotation speed (control rotation speed) of the hot water pump 40 by the inverter 46, the heat quantity flow rate estimated from the drive rotation speed and the temperature sensor 41 are measured. The amount of heat of the hot water supplied to the exhaust heat recovery device 20 may be calculated from the hot water temperature, and the control steps of steps S3 and S4 may be performed based on the calculation result. As described above, by using the temperature sensor 41, which is a temperature measuring means, instead of the heat flow meter 42 as the calorie measuring means, a relatively high cost heat flow meter can be replaced with a relatively low cost temperature sensor. Cost can be reduced. The temperature sensor 41 may be provided on the upstream side of the exhaust heat recovery unit 20, and may be provided on the upstream side of the hot water pump 40 as long as the temperature of the hot water supplied to the exhaust heat recovery unit 20 can be understood. Good.

  Subsequently, in step S5, the control unit 19 determines whether or not the heat pump steam generating device 10 is in an operating state within a predetermined emergency stop condition range. This emergency stop condition is a condition for determining whether or not to stop the operation of the heat pump unit 16 urgently. For example, the degree of superheat of the refrigerant in the heat pump unit 16, the inlet side in the exhaust heat recovery unit 20, One or more of the temperature difference of the hot water at the outlet side and the temperature or flow rate of the hot water supplied to the exhaust heat recovery device 20 are used. When two or more conditions are used, an emergency stop may be performed when any one of the conditions is satisfied.

  When the superheat degree of the refrigerant is used as the emergency stop condition, the control unit 19 obtains the superheat degree on the discharge side or the suction side of the compressor 22 in the heat pump unit 16, and the obtained superheat degree becomes less than a predetermined value for a predetermined time. In this case, it is determined that there is a concern that a liquid back may occur, and the operation of the compressor 22 is urgently stopped.

  When using the temperature difference of the hot water as the emergency stop condition, the control unit 19 obtains the temperature difference of the hot water on the inlet side and the outlet side of the exhaust heat recovery device 20, and the obtained temperature difference becomes less than the predetermined value for a certain time. In this case, it is determined that the amount of heat of the hot water recovered by the refrigerant is not sufficient, the degree of superheat on the discharge side of the compressor 22 becomes zero, and there is a concern that liquid back may occur, and the operation of the compressor 22 is stopped urgently. Therefore, when performing this control, it is necessary to provide the temperature sensor 41 on the upstream side of the exhaust heat recovery device 20 and also provide the temperature sensor (not shown) on the downstream side.

  When the temperature or flow rate of hot water is used as an emergency stop condition, the control unit 19 measures the temperature or flow rate of the hot water supplied to the exhaust heat recovery device 20, and the measured temperature or flow rate becomes less than a predetermined value for a certain time. In this case, it is determined that the amount of heat of the hot water recovered by the refrigerant is not sufficient, the degree of superheat on the discharge side of the compressor 22 becomes zero, and there is a concern that liquid back may occur, and the operation of the compressor 22 is stopped urgently.

  As described above, when it is determined in step S5 that the heat pump steam generator 10 is within the predetermined emergency stop condition range (Yes in step S5), the operation of the compressor 22 is emergency stopped (step S6). ). After that, when the temperature and pressure of the refrigerant in the refrigerant pipe of the heat pump unit 16 are reduced to equalize / equal pressure and the conditions for restarting are satisfied (Yes in step S7), the process returns to step S1 again. Return to start processing.

  On the other hand, if it is determined in step S5 that the heat pump steam generator 10 is not within the predetermined emergency stop condition range (No in step S5), that is, if it is in a normal operating state, the process returns to step S3 again. . Or when stopping the operation | movement of the said heat pump type steam generation apparatus 10, a predetermined | prescribed stop process is performed by stop operation or a timer, and the driving | operation of the heat pump type steam generation apparatus 10 is complete | finished.

  By the way, when the heat pump unit 16 is urgently stopped as in step S <b> 6, a considerable time is required until it can be restarted thereafter, during which steam is generated and supplied to the steam utilization facility 12. The situation that cannot be done. Therefore, in the heat pump steam generation apparatus 10 according to the present embodiment, an operation method that executes the standby operation mode before the emergency stop and prevents the emergency stop state from occurring can be used.

  FIG. 3 is a flowchart showing a procedure of another operation method of the heat pump steam generating apparatus 10 according to the first embodiment.

  Also in this driving method, steps S11 to S14 in FIG. 3 are the same as steps S1 to S4 in FIG.

  In step S15, the heat quantity monitoring unit 44 of the control unit 19 continues to monitor the heat quantity of the hot water supplied to the exhaust heat recovery unit 20 based on the measurement value of the heat flow meter 42 or the temperature sensor 41, and the monitored heat quantity is a predetermined value. In the above case, the process returns to step S13 (No in step S15). In this step S15, the monitored heat amount is equal to or greater than a predetermined value, for example, within a range in which the heat pump unit 16 can be stably operated in the normal operation mode without deficient in the amount of heat recovered from the hot water in the heat pump unit 16. A certain amount of heat. That is, for example, after it is determined that the monitored heat quantity is outside the set heat quantity range because the hot water temperature has greatly decreased in step S13 (No in step S13), the flow rate of the hot water pump 40 is increased and controlled in step S14. The amount of heat of hot water supplied to the heat recovery unit 20 is sufficiently recovered.

  On the other hand, when the amount of heat of the hot water supplied to the exhaust heat recovery device 20 becomes less than the predetermined value in Step S15 (Yes in Step S15), Step S16 is executed. For example, after it is determined in step S13 that the hot water temperature has greatly decreased and the monitored heat quantity is outside the set heat quantity range (No in step S13), the exhaust heat is discharged even if the flow rate of the hot water pump 40 is increased in step S14. If the amount of heat of the hot water supplied to the recovery device 20 is not sufficiently recovered, the process proceeds to the standby operation mode in step S16. That is, as the predetermined value in step S15, a value of the heat amount that is the same as or smaller than the set heat amount in step S13 is set.

  In the standby operation mode, the control unit 19 operates the heat pump unit 16 in an operation state in which the refrigerant circulation amount in the refrigeration cycle is suppressed as compared to the normal operation mode, or the minimum refrigerant circulation amount that can be executed in the refrigeration cycle. To control.

  Specifically, when the refrigerant circulation amount in the heat pump unit 16 is minimized in the standby operation mode, the opening of the throttle expander 26 is closed to the minimum opening within the controllable range, and at the same time, the compressor 22 Reduce the drive speed to the lowest controllable speed. In addition, since the minimum rotation speed is generally prescribed | regulated by the relationship of the lubricating oil supply mechanism, the compressor 22 is decelerated to this minimum rotation speed, for example. Further, in the standby operation mode, when the refrigerant circulation amount in the heat pump unit 16 is suppressed more than in the normal operation mode, the opening of the throttle expander 26 is closed more than in the normal operation mode, and at the same time, the drive rotation speed of the compressor 22 is increased. Is decelerated from the normal operation mode.

  When such a standby operation mode is executed, for example, the liquid refrigerant that is supplied little by little from the expansion expander 26 that has been throttled to the minimum opening recovers a small amount of heat existing in the exhaust heat recovery unit 20 and evaporates. Then, the operation of the heat pump unit 16 is continued by being sucked into the compressor 22 decelerated to the minimum rotation speed. At this time, if the liquid refrigerant introduced into the exhaust heat recovery unit 20 can continue to evaporate with a small amount of heat existing in the exhaust heat recovery unit 20, no liquid back is generated in the compressor 22. In the standby operation mode, the operation of the steam generation unit 14 is stopped, and the steam generation in the condenser 24 is interrupted.

  Even during such a standby operation mode, the heat quantity monitoring unit 44 of the control unit 19 continues to monitor the heat quantity of the hot water supplied to the exhaust heat recovery device 20 based on the measurement value of the heat flow meter 42 or the temperature sensor 41. (Step S17). If the monitored heat quantity is equal to or greater than the predetermined value (Yes in step S17), the process proceeds to step S18, the standby operation mode is switched to the normal operation mode, and the process returns to step S13. Or when stopping the operation | movement of the said heat pump type steam generation apparatus 10, a predetermined | prescribed stop process is performed by stop operation or a timer, and the driving | operation of the heat pump type steam generation apparatus 10 is complete | finished. It should be noted that the amount of heat monitored in step S17 is greater than or equal to a predetermined value means that the amount of heat of hot water supplied to the exhaust heat recovery device 20 is equal to or greater than the predetermined value in step S15 and the heat pump unit 16 From this, it is determined that a sufficient amount of heat can be recovered. That is, this is a case where the amount of heat of the hot water is recovered to the state before the transition to the standby operation mode.

  However, when returning from the standby operation mode to the normal operation mode, if the control pattern is suddenly changed from the pattern in the standby operation mode to the pattern in the normal operation mode, the drive rotation speed and throttle expansion of the compressor 22 are changed. There is a concern that the opening degree of the vessel 26 increases rapidly, and the refrigerant suddenly circulates in a large amount in the refrigeration cycle and causes liquid back to the compressor 22.

  Therefore, when returning from the standby operation mode to the normal operation mode, it is preferable to apply the same control pattern as the control pattern of the activation operation mode in the activation process in step S11. Thereby, the drive rotation speed of the compressor 22 and the opening degree of the throttle expander 26 are gradually increased, and the occurrence of liquid back can be prevented in advance.

  On the other hand, when the monitoring heat amount supplied to the exhaust heat recovery device 20 during the standby operation mode is less than a predetermined value (No in Step S17), the emergency stop condition is determined in Step S19. Steps S19, S20, and S21 are the same control steps as steps S5, S6, and S7 in FIG. 2, respectively.

  That is, when the amount of heat of hot water supplied to the exhaust heat recovery device 20 does not recover and the amount of heat of the hot water remaining in the exhaust heat recovery device 20 is used up during the standby operation mode, the heat pump unit 16 is no longer used. Thus, the refrigerant cannot be evaporated, and the superheat degree on the discharge side of the compressor 22 becomes zero. Therefore, it determines with it being in the emergency stop condition range by step S19 (Yes of step S19), and the driving | operation of the compressor 22 is urgently stopped (step S20). Thereafter, when the conditions for restarting are satisfied (Yes in step S21), the process returns to step S1 and the startup process is performed.

  On the other hand, if it is determined in step S19 that the heat pump steam generator 10 is not within the predetermined emergency stop condition range, the process returns to step S17 again to continue the standby operation mode.

  As described above, in the heat pump steam generator 10 according to the present embodiment, the heat quantity monitoring unit 44 that monitors the heat quantity of the hot water supplied to the exhaust heat recovery unit 20 by the hot water supply part 18, and the heat quantity monitoring part 44 And a control unit 19 that controls at least one circulation amount of the hot water and the refrigerant based on the monitoring result, and the control unit 19 includes a hot water supply unit so that the heat amount of the hot water monitored by the heat amount monitoring unit 44 becomes the set heat amount. 18 controls the flow rate of the hot water supplied to the exhaust heat recovery unit 20.

  Therefore, since it can respond flexibly to the change in the state of the hot water serving as the heat source of the heat pump unit 16 and can suppress the amount of heat of the hot water supplied to the exhaust heat recovery device 20 from being insufficient, the operation can be stably continued. The steam can be stably supplied to the steam utilization facility 12.

  In addition, when it becomes difficult for the control unit 19 to control the flow rate of the hot water supplied to the exhaust heat recovery unit 20 and the amount of heat of the hot water supplied to the exhaust heat recovery unit 20 becomes less than a predetermined value, A standby operation mode for performing control for reducing the refrigerant flow rate in the heat pump unit 16 is executed. Thereby, it is possible to suppress the emergency stop of the heat pump unit 16 as much as possible due to a change in the state of the hot water serving as a heat source. For example, even when the flow rate or temperature of the hot water is reduced, the heat pump unit 16 can be quickly stopped after the recovery. By shifting to the normal operation mode, it is possible to prevent the steam generation from being delayed for a long time.

2. Description of Heat Pump Steam Generating Device According to Second Embodiment FIG. 4 is a configuration diagram of a heat pump steam generating device 10A according to the second embodiment of the present invention. In addition, in the heat pump type steam generation apparatus 10A according to the second embodiment, elements having the same or similar functions and effects as those of the heat pump type steam generation apparatus 10 according to the first embodiment are denoted by the same reference numerals. Detailed description will be omitted.

  As shown in FIG. 4, the heat pump steam generation device 10 </ b> A is similar to the heat pump steam generation device 10 shown in FIG. 1, and includes a steam generation unit 14, a heat pump unit 16, a hot water supply unit 18, and a control unit 19. Is provided. However, the configuration of the hot water supply unit 18 of the heat pump steam generation device 10A according to the present embodiment is changed compared to the heat pump steam generation device 10 shown in FIG. And a temperature sensor 52 for measuring the temperature on the outlet side in addition to the temperature sensor 41 for measuring the temperature of the hot water on the inlet side of the exhaust heat recovery unit 20.

The flow meter 50 is a measuring device that measures the flow rate (m ³ / s) of hot water supplied to the exhaust heat recovery device 20 through the hot water pipe 28. The measurement value at the flow meter 50 is transmitted to the heat quantity monitoring unit 44 of the control unit 19 and serves as an index for estimating the heat quantity (heat flow rate) of the hot water. The heat quantity monitoring unit 44 is an inverter that controls the drive speed of the hot water pump 40 in order to control the heat quantity (J) of hot water supplied to the exhaust heat recovery unit 20 based on the measured value of the flow rate of hot water by the flow meter 50. A predetermined control signal is output to 46.

  The heat quantity monitoring unit 44 constituting the control unit 19 of the present embodiment monitors the heat quantity of the hot water supplied to the exhaust heat recovery device 20 by the hot water pipe 28, and based on the monitoring result, the heat pump unit 16 is moved from the normal operation mode. Switch to standby operation mode.

  Next, the operation of the heat pump type steam generator 10A according to the present embodiment will be described with reference to the flowchart of FIG.

  Also in the operating method of the heat pump steam generating apparatus 10A according to the present embodiment, steps S101 and S102 in FIG. 5 are the same as steps S1 and S2 in FIG.

  However, step S102 for monitoring the amount of heat in the normal operation mode of the present embodiment is different from step S2 in FIG. 2 in the method for monitoring the amount of heat of hot water, and the following first to fourth methods can be exemplified. Note that a plurality of the first to fourth methods may be used at the same time, and in this case, the determination may be made based on whether one of the plurality of methods has reached the determination criterion.

  First, whether or not the amount of heat of the hot water supplied to the exhaust heat recovery device 20 has become less than a predetermined value by acquiring the measured value of the flow meter 50 as needed for the heat amount monitoring during the normal operation mode in step S102. To monitor. That is, when the flow rate of warm water decreases, it can be estimated that the amount of heat has decreased. Therefore, for example, the measured value of the flow rate by the flow meter 50 is compared with the average flow rate for a certain period of time (for example, 10 seconds) immediately before that, and it is determined whether or not the ratio is below a certain ratio (for example, 50%). Therefore, when this method is used, the temperature sensors 41 and 52 can be omitted.

  Secondly, the amount of heat of the hot water supplied to the exhaust heat recovery device 20 is less than a predetermined value by monitoring the amount of heat during the normal operation mode in step S102 as needed by knowing the drive rotational speed of the hot water pump 40. Monitor whether or not. That is, the control unit 19 transmits a command to the inverter 46 to control the drive rotation speed of the hot water pump 40, and therefore, always acquires the drive rotation speed of the hot water pump 40. It can be presumed that the amount of heat of the hot water has decreased. Therefore, for example, the drive rotation speed of the hot water pump 40 is compared with the average drive rotation speed for a certain period of time (for example, 10 seconds) immediately before it, and it is determined whether or not it has fallen below a certain ratio (for example, 50%). Therefore, when this method is used, the temperature sensors 41 and 52 can be omitted.

  Third, the amount of heat in the normal operation mode in step S102 is monitored by measuring the temperature difference between the hot water at the inlet side and the outlet side of the exhaust heat recovery unit 20, that is, the difference in measured values between the temperature sensor 41 and the temperature sensor 52. By acquiring from time to time, it is monitored whether or not the amount of heat of the hot water supplied to the exhaust heat recovery device 20 has become less than a predetermined value. That is, when the temperature difference before and after the exhaust heat recovery device 20 increases, the flow rate decreases, and as a result, it can be estimated that the amount of heat has decreased. Therefore, for example, the temperature difference between the measured temperatures of the temperature sensors 41 and 52 is compared with the average temperature difference for a certain period of time (for example, 10 seconds) immediately before that to determine whether or not a certain ratio (for example, 150%) has been exceeded. judge. Therefore, when this method is used, the flow meter 50 can be omitted.

  Fourthly, the heat quantity monitoring during the normal operation mode in step S102 is performed by acquiring the temperature of the hot water at the inlet side of the exhaust heat recovery device 20, that is, the measured value of the temperature sensor 41, as needed. It is monitored whether or not the amount of heat of the hot water supplied to the battery becomes less than a predetermined value. That is, when the temperature of the hot water supplied to the exhaust heat recovery device 20 decreases, it can be estimated that the amount of heat has decreased. Therefore, for example, the temperature measured by the temperature sensor 41 is compared with the average temperature for a certain period of time (for example, 10 seconds) immediately before it, and it is determined whether or not the temperature has fallen below a certain ratio (for example, 50%). Therefore, when this method is used, the temperature sensor 52 and the flow meter 50 can be omitted.

  These first to fourth heat quantity monitoring methods can also be used for heat quantity monitoring (steps S2, S3, S12, S13) of the heat pump steam generator 10 according to the first embodiment described above. In addition, the heat amount monitoring (steps S2 and S12) of the heat pump steam generator 10 according to the first embodiment can be used for the heat amount monitoring of the heat pump steam generator 10A according to the present embodiment.

  By each of these methods, when the amount of heat of the hot water supplied to the exhaust heat recovery device 20 becomes less than a predetermined value in step S103 (Yes in step S103), the standby operation mode is executed in step S104. . The standby operation mode executed in step S104 is the same or similar control pattern as the standby operation mode executed in step S16 in FIG.

  Steps S105 to S106 and S107 to S109 may be the same or similar control steps as steps S17 to S18 and S19 to S21 in FIG.

  As described above, in the heat pump steam generation device 10A according to the present embodiment, the heat quantity monitoring unit 44 that monitors the heat quantity of the hot water supplied to the exhaust heat recovery unit 20 by the hot water supply part 18 and the heat quantity monitoring part 44 And a control unit 19 that controls the flow rate of the refrigerant based on the monitoring result. The control unit 19 has a heat quantity of hot water supplied to the exhaust heat recovery unit 20 monitored by the heat quantity monitoring unit 44 that is less than a predetermined value. In this case, the standby operation mode is executed in which the refrigerant flow rate in the heat pump unit 16 is controlled to be lower than that in the normal operation mode.

  Therefore, even if the state of the hot water that becomes the heat source of the heat pump unit 16 changes and the amount of heat is insufficient, the refrigerant circulation amount in the heat pump unit 16 is suppressed by shifting to the standby operation mode, and exhaust heat recovery is performed. The operation of the heat pump unit 16 can be continued using the amount of heat of the hot water remaining in the vessel 20, and the emergency stop of the heat pump unit 16 can be suppressed as much as possible. Thereby, after recovery of the heat quantity of the hot water, it is possible to quickly shift to the normal operation mode, and it is possible to avoid that the steam generation is delayed for a long time.

  It should be noted that the present invention is not limited to the above-described embodiment, and it is needless to say that the present invention can be freely changed without departing from the gist of the present invention.

DESCRIPTION OF SYMBOLS 10,10A Heat pump type steam generator 12 Steam utilization equipment 14 Steam generation part 16 Heat pump part 18 Hot water supply part 19 Control part 20 Waste heat recovery device 22 Compressor 24 Condenser 26 Throttle expander 28 Hot water piping 40 Hot water pump 41, 52 Temperature sensor 42 Heat flow meter 44 Heat quantity monitor 46 Inverter 50 Flow meter

Claims (17)

An exhaust heat recovery unit that recovers heat from hot water and heats the refrigerant, a compressor that compresses the refrigerant that exits the exhaust heat recovery unit, a condenser that cools the refrigerant compressed by the compressor, and an output from the condenser A heat pump unit that circulates the refrigerant by connecting a throttle expander for expanding the refrigerant in an annular shape,
A hot water supply section for supplying and discharging the hot water to the exhaust heat recovery device;
A steam generation unit that supplies heated water to the condenser and heats the heated water with the refrigerant to generate steam;
A heat pump type steam generator comprising:
A heat quantity monitoring unit that monitors the amount of heat of the hot water supplied to the exhaust heat recovery unit by the hot water supply unit;
Based on the monitoring result in the heat quantity monitoring unit, a control unit for controlling the flow rate of at least one of the hot water and the refrigerant;
A heat pump steam generator characterized by comprising: In the heat pump type steam generator according to claim 1,
The control unit controls a flow rate of hot water supplied to the exhaust heat recovery device by the hot water supply unit so that a heat amount of the hot water monitored by the heat amount monitoring unit becomes a set heat amount. Steam generator. In the heat pump type steam generator according to claim 2,
The hot water supply unit is provided with a calorimeter measuring means for measuring the amount of heat of hot water supplied to the exhaust heat recovery device, and a hot water flow rate adjusting means for adjusting the amount of hot water flowing through the exhaust heat recovery device,
The controller controls the flow rate of the hot water by controlling the flow rate of the hot water by driving the hot water flow rate adjusting means so that the heat quantity of the hot water measured by the calorie measurement means becomes a preset heat quantity. A heat pump type steam generator controlled to the set heat quantity. In the heat pump type steam generator according to claim 3,
The calorific value measuring means is a temperature measuring means for measuring a temperature of hot water supplied to the exhaust heat recovery device,
The controller is configured such that the amount of hot water supplied to the exhaust heat recovery device is preset based on the temperature of the hot water measured by the temperature measuring means and the flow rate of the hot water sent out by the hot water flow rate adjusting means. The heat pump steam generator is characterized by controlling the amount of heat of the warm water to the set amount of heat by controlling the flow of the warm water by driving and controlling the warm water flow rate adjusting means. In the heat pump type steam generator according to claim 1,
The control unit has a standby operation mode for controlling the refrigerant flow rate in the heat pump unit to be lower than that in a normal operation mode when the heat amount of the hot water monitored by the heat amount monitoring unit becomes less than a predetermined value. A heat pump type steam generator characterized by being executed. In the heat pump type steam generator according to claim 5,
The heat quantity monitoring unit determines whether or not the heat quantity is less than a predetermined value based on a flow rate of warm water supplied to the exhaust heat recovery unit. In the heat pump type steam generator according to claim 5 or 6,
Whether the heat quantity is less than a predetermined value based on a temperature difference between the temperature of the hot water supplied to the exhaust heat recovery unit and the temperature of the hot water discharged from the exhaust heat recovery unit. The heat pump type steam generator characterized by judging. In the heat pump type steam generator according to any one of claims 5 to 7,
The warm water supply unit is provided with a pump for sending the warm water to the exhaust heat recovery unit,
The heat quantity monitoring unit determines whether or not the heat quantity is less than a predetermined value based on the drive rotational speed of the pump. In the heat pump type steam generator according to any one of claims 5 to 8,
The heat quantity monitoring unit determines whether or not the heat quantity is less than a predetermined value based on a temperature of hot water supplied to the exhaust heat recovery unit. In the heat pump type steam generator according to any one of claims 5 to 9,
During the standby operation mode, when the heat amount is determined by the heat amount monitoring unit to be equal to or greater than a predetermined value, the control unit increases the refrigerant flow rate in the heat pump unit and returns to the normal operation mode. A heat pump type steam generator characterized by the above. In the heat pump type steam generator according to claim 10,
When the control unit returns from the standby operation mode to the normal operation mode, the control unit executes the same control pattern as when the heat pump unit is activated. In the heat pump type steam generator according to any one of claims 1 to 11,
The control unit, the degree of superheat on the discharge side or suction side of the compressor, the temperature difference between the temperature of hot water supplied to the exhaust heat recovery device and the temperature of hot water discharged from the exhaust heat recovery device, or A heat pump steam generator, wherein the operation of the heat pump unit is stopped when the temperature or flow rate of the hot water supplied to the exhaust heat recovery unit is less than a predetermined value for a certain time or more. In the heat pump type steam generator according to claim 1,
The control unit controls a flow rate of hot water supplied from the hot water supply unit to the exhaust heat recovery unit so that a heat amount of the hot water monitored by the heat amount monitoring unit becomes a set heat amount, and the exhaust heat recovery unit When the amount of heat of hot water supplied to the heat pump becomes less than a predetermined value, a standby operation mode for performing control to reduce the refrigerant flow rate in the heat pump unit is executed. It is an operation method of a heat pump steam generator that recovers heat from hot water using a heat pump cycle and transmits the recovered heat to water to be heated to generate steam,
A method for operating a heat pump steam generator, wherein the heat amount of the hot water is monitored, and the flow amount of at least one of the hot water and the refrigerant flowing through the heat pump cycle is controlled based on the monitoring result. In the operation method of the heat pump type steam generator according to claim 14,
A method of operating a heat pump steam generator, wherein the flow rate of the hot water is controlled so that the amount of heat of the hot water to be monitored becomes a set heat amount. In the operation method of the heat pump type steam generator according to claim 14,
Operation of a heat pump steam generator, wherein when the amount of heat of the hot water to be monitored becomes less than a predetermined value, the operation mode is switched to a standby operation mode in which the refrigerant flow rate is controlled to be lower than a normal operation mode. Method. In the operation method of the heat pump type steam generator according to claim 14,
Standby operation for controlling the flow rate of the warm water so that the monitored heat quantity of the hot water becomes a set heat quantity, and for reducing the refrigerant flow rate when the heat quantity of the warm water becomes less than a predetermined value. The operation method of the heat pump type steam generator characterized by switching to a mode.

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