JP2017044377A - Heat pump type steam generation device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a heat pump type steam generation device which can start stably by suppressing failure in a compressor.SOLUTION: A heat pump type steam generation device 12 includes: a heat pump part 18 in which a compressor 21, a condenser 22, an expansion mechanism 24 and an evaporator 26 are connected in an annular manner, and which recovers heat from an external heat source by the evaporator 26; and a steam generation part 16 for supplying water to be heated to the condenser 22, heating the water to be heated by a refrigerant and for generating steam. At refrigerant piping 27a for connecting a discharge side of the compressor 21 and an inlet side of the condenser 22, a check valve 30 is provided for preventing a backflow of the refrigerant from the condenser 22 to the compressor 21 while the compressor 21 is stopped.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a heat pump steam generator that recovers heat from an external heat source to generate steam.

As one of steam generating apparatuses, there is a heat pump steam generating apparatus that generates steam by recovering heat from warm water such as industrial waste water or waste water such as used cooling water (for example, Patent Document 1). In the heat pump steam generator, the evaporator of the heat pump unit functions as an exhaust heat recovery device, where heat is recovered from the heat source hot water into the refrigerant, and the water to be heated is heated by the condenser using the recovered heat. Since steam is generated, there is an advantage that the running cost and CO ₂ emission amount can be reduced as compared with the combustion system steam generating apparatus that generates steam using boiler equipment or the like.

JP 2012-247156 A

  By the way, in the heat pump type steam generator as described above, since water to be heated is generated by a condenser to generate steam, it is necessary to use a refrigerant having a characteristic having a high critical temperature of 100 ° C. or higher for the heat pump unit. .

  However, this type of refrigerant has a boiling point higher than that of a refrigerant used in a general refrigeration apparatus, and for example, has a characteristic of liquefying at normal pressure and normal temperature. That is, when the refrigerant is liquefied while the heat pump type steam generator is stopped, there is a concern that the liquid refrigerant is sucked into the compressor at the time of startup and liquid compression (liquid back) occurs. In addition, when a large amount of liquid refrigerant is accumulated in the compressor or the decompression mechanism while the apparatus is stopped, it may be difficult to appropriately control the operation speed of the compressor at the time of startup and the opening degree of the expansion mechanism. . In addition, if a large amount of liquid refrigerant accumulates in the compressor during stoppage, a large amount of refrigerant dissolves in the refrigerating machine oil, and the refrigerant boiles under reduced pressure at the time of start-up, causing a foaming phenomenon (oil forming) in the refrigerating machine oil, causing problems in the compressor. There are also concerns.

  The present invention has been made in view of the above-described problems of the prior art, and an object of the present invention is to provide a heat pump type steam generator that can suppress the occurrence of problems in the compressor and can be stably started.

  The heat pump type steam generator according to the present invention includes a compressor, a condenser, an expansion mechanism, and an evaporator connected in a ring shape, and a heat pump unit that recovers heat from an external heat source by the evaporator, and water to be heated in the condenser. And a steam generation unit that generates steam by heating the water to be heated with a refrigerant, between the discharge side of the compressor and the inlet side of the condenser The refrigerant pipe to be connected is provided with a valve for preventing a reverse flow of the refrigerant from the condenser to the compressor when the compressor is stopped.

  According to such a configuration, since the reverse flow of the refrigerant from the condenser to the compressor is prevented when the operation of the apparatus is stopped, for example, the refrigerant on the high pressure side between the condenser and the expansion mechanism immediately after the operation is stopped Therefore, it is possible to prevent a large amount of refrigerant from remaining in the compressor and the expansion mechanism, and to store a large amount of refrigerant in the condenser when stopped. Thereby, at the time of starting after operation stop, generation | occurrence | production of malfunctions, such as liquid compression in a compressor and oil forming, can be suppressed. Further, since the place where the refrigerant is accumulated at the time of start-up can be predicted, the operation speed of the compressor and the opening degree of the expansion mechanism can be controlled smoothly, and a stable start-up operation is possible.

  The said refrigerant | coolant may be the characteristic which has a boiling point in the use temperature range of the said heat pump vapor generation apparatus at atmospheric pressure. By using a refrigerant with such characteristics, high temperature can be secured and reliable water vapor generation is possible, but depending on the ambient temperature at the time of shutdown of the device, the refrigerant in the heat pump part liquefies, liquid compression, oil forming, etc. There is a concern of causing the occurrence of defects. However, in the heat pump type steam generator, the backflow prevention valve is provided in the refrigerant pipe that connects between the discharge side of the compressor and the inlet side of the condenser, so that such a problem can be avoided.

  An on-off valve may be provided between the outlet side of the condenser of the heat pump unit and the expansion mechanism. If it does so, a large amount of refrigerant | coolants can be reliably confine | sealed in a condenser by carrying out closed control of the on-off valve at the time of operation stop of an apparatus. Thereby, generation | occurrence | production of malfunctions, such as liquid compression of the compressor at the time of starting, can be avoided more reliably, and the stable starting operation can be performed.

  A control unit that performs a pump-down operation for introducing the refrigerant of the heat pump unit into the condenser by controlling the closing of the on-off valve and driving the compressor when the heat pump steam generator is stopped. It is good also as a structure provided with. If it does so, the refrigerant | coolant in an expansion mechanism, an evaporator, a compressor, and refrigerant | coolant piping can be compulsorily collected to a condenser at the time of an operation stop.

  The steam generation unit includes a water supply path for supplying heated water to the condenser, and a gas-liquid two-phase flow generated when the heated water is heated by the refrigerant in the condenser. A water vapor separator for separating the water vapor, a circulation path for circulating the separated water to the condenser together with heated water from the water supply path, and a delivery path for sending the water vapor separated by the water vapor separator to the outside. And the structure by which the said condenser was installed in the low position rather than the said water vapor separator may be sufficient. As a result, liquid phase water accumulated in the water vapor separator during operation is concentrated in the condenser when it is stopped, so that there is not enough air to be heated by the condenser (heated water) in the condenser during startup. This can be avoided and the efficiency of the heat exchanger can be improved promptly. Moreover, since the liquid level of the water in the liquid phase is stably held in the condenser even during operation, the idling operation in which the object to be heated by the refrigerant is insufficient during operation is also suppressed.

  Between the condenser of the heat pump unit and the expansion mechanism, heat exchange is performed to exchange heat between the refrigerant exiting the condenser and the water to be heated before being introduced into the condenser flowing through the water supply path. The steam generator may be configured such that the condenser is installed at a lower position than the heat exchanger. Thereby, the supply of heated water from the heat exchanger to the condenser becomes smooth during operation of the apparatus, and the heated water in the heat exchanger can also be collected in the condenser when stopped.

  In the heat pump unit, the condenser may be installed at a lower position than the evaporator. Thereby, the refrigerant | coolant which has accumulated in the evaporator at the time of operation stop of an apparatus can be more smoothly integrated into a condenser.

  According to the present invention, since the backflow of the refrigerant from the condenser to the compressor is prevented when the operation of the apparatus is stopped, for example, the refrigerant between the condenser and the expansion mechanism flows back to the compressor immediately after the operation is stopped. A large amount of refrigerant can be prevented from remaining in the compressor and the expansion mechanism, and a large amount of refrigerant can be stored in the condenser when stopped. Thereby, at the time of starting after operation stop, generation | occurrence | production of malfunctions, such as liquid compression in a compressor and oil forming, can be suppressed. Further, since the place where the refrigerant is accumulated at the time of start-up can be predicted, the operation speed of the compressor and the opening degree of the expansion mechanism can be controlled smoothly, and a stable start-up operation is possible.

It is a perspective view showing the appearance structure of the heat pump type steam generator concerning one embodiment of the present invention. It is a block diagram which shows typically the circuit structure of the heat pump type steam generation apparatus shown in FIG. It is a perspective view which shows the structure of the heat pump part installed in the housing | casing, and a steam generation part. It is a perspective view of the heat pump part shown in FIG. It is a perspective view of the steam production | generation part shown in FIG. FIG. 6A is a front view of the heat pump unit shown in FIG. 4, FIG. 6A shows the state of the refrigerant during operation of the heat pump steam generator, and FIG. 6B is a diagram when the heat pump steam generator is stopped. The state of the refrigerant is shown. FIG. 7A is a front view of the steam generation unit shown in FIG. 5, FIG. 7A shows the state of water during operation of the heat pump steam generation device, and FIG. 7B is when the heat pump steam generation device is stopped. Shows the state of water.

  Hereinafter, preferred embodiments of the heat pump type steam generator according to the present invention will be described in detail with reference to the accompanying drawings.

  FIG. 1 is a perspective view showing an external structure of a heat pump steam generator 12 according to an embodiment of the present invention, and FIG. 2 schematically shows a circuit structure of the heat pump steam generator 12 shown in FIG. It is a block diagram. The heat pump steam generator 12 is a system that generates steam using exhaust heat recovered from warm water such as factory waste water, and the generated steam is sent to an external steam utilization facility such as a drying device or a sterilizer.

  First, a configuration example of a circuit structure of the heat pump type steam generator 12 will be described.

  As shown in FIG. 2, the heat pump steam generator 12 generates heat by evaporating water, generates steam, and heats the hot water (heat source hot water) supplied by the hot water supply unit 17 and the steam generator 16 that sends the water to the outside. And a heat pump unit 18 that supplies this heat as a heat source for generating steam in the steam generation unit 16 and a control unit 20 that controls the system.

  The heat pump unit 18 recovers heat from hot water, a compressor 21 that compresses the refrigerant, a condenser 22 that condenses the refrigerant compressed by the compressor 21, an expansion mechanism 24 that decompresses the refrigerant that has exited the condenser 22, and Then, the evaporator 26 that evaporates the refrigerant is connected in an annular shape using the refrigerant pipes 27a to 27e to circulate the refrigerant. In the present embodiment, a heater (heat exchanger) 28 for preheating the feed water is connected between the outlet side of the condenser 22 and the inlet side of the expansion mechanism 24. The expansion mechanism 24 is an electronic expansion valve, for example, and can adjust the opening degree under the control of the control unit 20. Hereinafter, the refrigerant pipes 27a to 27e may be collectively referred to as the refrigerant pipe 27.

  A check valve 30 is provided in the refrigerant pipe 27 a between the compressor 21 and the condenser 22, and an open / close valve 31 is provided in the refrigerant pipe 27 c between the heater 28 and the expansion mechanism 24. The check valve 30 is a valve that allows the refrigerant to flow from the compressor 21 to the condenser 22 and prevents the refrigerant from flowing backward from the condenser 22 to the compressor. In the case of this embodiment, the check valve 30 only needs to be able to prevent the refrigerant backflow while the heat pump steam generator 12 is stopped, and usually the backflow itself does not occur during operation of the apparatus. Instead, an on-off valve (electromagnetic valve) that is controlled to be closed by the control unit 20 when the apparatus is stopped may be used. The on-off valve 31 is an electromagnetic valve, for example, and can be opened and closed under the control of the control unit 20.

  The refrigerant that has been compressed by the compressor 21 to a high temperature and high pressure is cooled and condensed by exchanging heat with water circulating in the steam generation unit 16 in the condenser 22. The refrigerant that has exited the condenser 22 is preheated with water flowing through a water supply pipe (water supply path) 32a by the heater 28 and further cooled, and then adiabatically expanded by the expansion mechanism 24, and the hot water supply unit 17 is supplied by the evaporator 26. It absorbs heat from the flowing hot water, evaporates and returns to the compressor 21. The operation speed of the compressor 21 is controlled through an inverter based on the pressure and temperature of the refrigerant on the suction side and the discharge side under the control of the control unit 20.

  The steam generating unit 16 uses a refrigerant circulating in the heat pump unit 18 as a heat source to evaporate water to generate steam, and a vapor-liquid two-phase flow including water vapor and water generated by the condenser 22 is converted into steam. A water vapor separator 34 that separates into water, a circulation pipe (circulation path) 32b that joins the water separated by the water vapor separator 34 with the heated water supplied from the water supply pipe 32a and introduces it into the condenser 22; A steam pipe (steam path) 32c for guiding the gas-liquid two-phase flow from the condenser 22 to the steam separator 34, and a delivery pipe (sending path) for sending the steam separated by the steam separator 34 to an external steam utilization facility ) 32d.

  The water vapor separator 34 is configured by a cylindrical container along the vertical direction, and stores water inside the container by replenishing water from a water supply pipe 32a connected to a circulation pipe 32b connected to a lower end wall. The water supply pipe 32 a introduces water (heated water) from a water pipe or water tank (not shown) to the circulation pipe 32 b by a water supply pump 37. The operation of the water supply pump 37 is controlled by the control unit 20. The circulation pipe 32 b is a path that communicates from the lower end wall of the water vapor separator 34 to the condenser 22. The steam pipe 32c is a path through which the gas-liquid two-phase flow circulates from the condenser 22 to the upper side wall of the water vapor separator 34.

  The delivery pipe 32d is connected to the upper end wall of the water vapor separator 34, and is a path that is supplied from the steam pipe 32c into the water vapor separator 34 and sends out the steam after the water is separated here. The delivery pipe 32d is provided with a pressure regulating valve 38 for controlling the flow rate and pressure of the steam sent out from the heat pump steam generator 12 by appropriately adjusting the opening degree under the control of the control unit 20. It has been.

  In the steam generation unit 16, water is supplied from the water vapor separator 34 to the condenser 22 through the circulation pipe 32 b due to the difference in level between the water surface of the water vapor separator 34 and the water surface of the condenser 22, and the condenser 22. A thermosiphon circuit is formed in which the water vapor generated in (1) is sent from the steam pipe 32c to the delivery pipe 32d via the water vapor separator 34. As a result, water can be circulated without providing a power source such as a circulation pump in the water circulation system formed by the circulation pipe 32b, the steam pipe 32c, and the water vapor separator 34. Hereinafter, the water supply pipe 32a, the circulation pipe 32b, the steam pipe 32c, and the delivery pipe 32d through which water flows while changing from the liquid phase to the gas phase may be collectively referred to as the water pipe 32.

  The hot water supply unit 17 includes a hot water supply pipe 17 a that supplies hot water to the evaporator 26 and a hot water discharge pipe 17 b that discharges hot water from the evaporator 26. The hot water supply pipe 17a is provided with a hot water pump (not shown) that supplies hot water supplied from a hot water supply source such as an external hot water tank at a predetermined flow rate.

  The heat pump unit 18 of the heat pump steam generator 12 has a characteristic refrigerant having a boiling point in the operating temperature range of the heat pump steam generator 12 at atmospheric pressure, for example, a temperature range of about −5 ° C. to 40 ° C., For example, R245fa (boiling point of about 15 ° C.) is used. That is, the refrigerant sealed in the heat pump unit 18 needs to have a characteristic having a high critical temperature of 100 ° C. or higher because it is necessary to generate steam by heating the water to be heated in the steam generation unit 16 by the condenser 22. . This type of refrigerant tends to have a higher boiling point than refrigerants used in general refrigeration equipment (for example, the boiling point is about minus several tens of degrees Celsius). For example, some refrigerants such as R245fa liquefy at normal pressure and normal temperature. .

  Next, a specific configuration of each part of the heat pump steam generator 12 will be described.

  In the heat pump type steam generation device 12 according to the present embodiment, the elements constituting the steam generation unit 16, the hot water supply unit 17, and the heat pump unit 18 are accommodated in the housing 14 (see FIG. 1). .

  As shown in FIG. 1, the housing 14 has a box-like structure that is installed on the ground or floor via legs 39, and an opening provided on the front can be opened and closed by a door 40, while the front The other five surfaces (top surface, bottom surface, back surface, left and right side surfaces) are closed by the panel 42. An operation panel 44 is provided on the door 40 serving as a front wall of the housing 14 to be operated when an operator performs various settings, operation commands, and the like for the control unit 20 of the heat pump steam generator 12.

  On the inner surface of the door 40, an electrical box 46 that houses electrical components constituting the control unit 20 is attached, and a front air inlet 48 that sucks external air is provided in the approximate center of the door 40. The outside air sucked from the front air inlet 48 cools the electric parts in the electric box 46 and is then sucked from the air inlet provided at the lower back of the housing 14 to generate heat generating devices (for example, FIG. 3) in the housing 14. The motor 21m for driving the compressor 21 shown in FIG. 5 is combined with the cooled outside air, and is discharged to the outside through an exhaust port provided at the upper back of the housing 14.

  FIG. 3 is a perspective view showing the configuration of the heat pump unit 18 and the steam generation unit 16 installed in the housing 14. 4 is a perspective view of the heat pump unit 18 shown in FIG. 3, and FIG. 5 is a perspective view of the steam generation unit 16 shown in FIG. 6 is a front view of the heat pump unit 18 shown in FIG. 4, FIG. 7 is a front view of the steam generation unit 16 shown in FIG. 5, and FIG. 6 (A) and FIG. The state of the refrigerant and water (heated water) during operation of the heat pump steam generator 12 is shown. FIGS. 6B and 7B show the refrigerant and water when the heat pump steam generator 12 is stopped ( The state of water to be heated) is shown.

  As shown in FIGS. 3 and 4, the heat pump unit 18 includes a compressor 21 and a motor 21 m for driving the compressor 21 arranged side by side along the front side on the bottom surface of the casing 14, and the condenser 22 is disposed in the casing. It is arranged on the back side of the compressor 21 on the bottom surface of the body 14. On the other hand, the evaporator 26 and the heater 28 are arranged side by side with a beam or the like at a position on the back side of the motor 21m and on the side of the condenser 22 and higher than the compressor 21 and the condenser 22. It is installed.

  In the heat pump unit 18, the condenser 22 is located at a lower position than the evaporator 26 and the heater 28, and specifically, a refrigerant inlet port 50 that is a refrigerant inlet to the condenser 22 and to which the refrigerant pipe 27 a is connected. The refrigerant outlet from the evaporator 26 is at the same height as or below the refrigerant outlet port 51 to which the refrigerant pipe 27e is connected. In the present embodiment, the condenser 22 is lower than the lower surface of the evaporator 26. Is in a low position (see also FIG. 6). Further, the refrigerant inlet port 50 of the condenser 22 is at the same height as or lower than the refrigerant inlet port 52 that is an inlet of the refrigerant to the heater 28 and to which the refrigerant pipe 27b is connected. Further, the refrigerant outlet port 51 of the evaporator 26 is at the same height position or at the top as the refrigerant inlet port 52 of the heater 28. In addition, in this embodiment, since the ease of movement of liquid refrigerant or liquid phase water is taken into consideration, the height position of each port is in the same position or upper (lower) means that each port (pipe) It may be paraphrased that the lower surface of the inner diameter is at the same position or at the upper part (lower part), and so on.

  As described above, in the heat pump unit 18, the condenser 22 is disposed at the lowest position among the devices in which the refrigerant circulates through the refrigerant pipe 27. At this time, the compressor 21 is also installed on the floor surface of the housing 14 like the condenser 22, but the compression chamber 21 a in which the refrigerant actually circulates inside the compressor 21 is the uppermost part of the compressor 21. Therefore, the compressor 21 is located higher than the condenser 22 at a height position in the refrigerant circulation portion. In this embodiment, the compressor 21 has an open structure in which power from a separate motor 21m is transmitted via a belt 43 (see FIG. 3), but the motor 21m is integrated into a hermetic seal. A compressor having a mold structure may be used.

  As shown in FIGS. 3 and 5, in the steam generation unit 16, the condenser 22 and the water supply pump 37 are disposed on the back surface side of the compressor 21 and the motor 21 m on the bottom surface of the housing 14. On the other hand, the water vapor separator 34 is disposed above the condenser 22 at a position higher than the condenser 22 and the water supply pump 37 using a beam material or the like. The heater 28 is disposed on the side of the water vapor separator 34 and at a position higher than the condenser 22 and the water supply pump 37 using a beam material or the like.

  In the steam generation unit 16, the condenser 22 is positioned lower than the water vapor separator 34, and specifically, a water inlet port 54 that is an inlet of heated water to the condenser 22 and to which the circulation pipe 32 b is connected. In the case of this embodiment, the upper surface of the condenser 22 is the water outlet port 55 (steam water outlet), which is the outlet of the separated water from the water vapor separator 34 and below the water outlet port 55 to which the circulation pipe 32b is connected. The bottom surface of the separator 34) (see also FIG. 7). Further, the condenser 22 is positioned lower than the heater 28. Specifically, the water inlet port 54 of the condenser 22 is an outlet of water to be heated from the heater 28 and is connected to the circulation pipe 32b. In the present embodiment, the upper surface of the condenser 22 is located lower than the lower surface of the heater 28. The water outlet port 56 is connected to the water supply pipe 32a.

  As described above, in the steam generation unit 16, the condenser 22 is disposed at the lowest position when the water supply pump 37 is excluded from the devices through which water flows through the water pipe 32.

  Next, the operation and action of the heat pump steam generator 12 configured as described above will be described.

  In the heat pump type steam generator 12, when the compressor 21 is driven during the operation, steam in which the water to be heated is heated by the refrigerant is generated in the condenser 22, and the steam separated in the steam separator 34 is sent out from the delivery pipe. 32d is sent to an external steam utilization facility.

  During this operation, in the heat pump unit 18, the refrigerant discharged from the compressor 21 is condensed in the condenser 22 as shown in FIG. 6A, so the refrigerant pipe 27 b, the heater 28, and the refrigerant are arranged from the lower part of the condenser 22. The lower part of the evaporator 26 is filled with the liquid refrigerant RL through the pipe 27c and the expansion mechanism 24. Moreover, in the steam generation part 16, as shown to FIG. 7 (A), the heater 28 and the circulation pipe 32b are filled with the to-be-heated water W from the feed water pipe 32a to which to-be-heated water is supplied, and also gas-liquid two-phase flow The portion excluding the upper portion of the condenser 22 and the lower portion of the water vapor separator 34 to the circulation pipe 32b are filled with heated water W.

  When the operation of the heat pump type steam generator 12 is stopped from this state, depending on the environmental temperature, the refrigerant having the characteristic of having a boiling point at normal pressure at atmospheric pressure as described above may be liquefied in the heat pump unit 18. . Further, the water to be heated remaining in the steam generating section 16 flows downward due to gravity.

  Therefore, in the heat pump steam generator 12, when the operation is stopped, the on-off valve 31 is controlled to be closed under the control of the control unit 20, and the pump-down operation for continuing the operation of the compressor 21 for a predetermined time is executed. By this pump-down operation, the gas refrigerant remaining in the evaporator 26 and the gas refrigerant remaining in the compressor 21 flow into the condenser 22 through the check valve 30 and close the on-off valve 31. Therefore, it is stored between the condenser 22 and the heater 28. As a result, when the refrigerant in the heat pump unit 18 is liquefied when stopped, the liquid refrigerant RL is collected in the condenser 22 (and the heater 28) as shown in FIG. 6B. Further, in the heat pump unit 18, as shown in FIG. 6B, the condenser 22 is at the lowest position in the circuit, so that the liquid refrigerant RL gathers to the condenser 22 by gravity, and most of the refrigerant (liquid refrigerant) RL) is collected and stored in the condenser 22.

  Further, when the steam generating unit 16 is stopped, it is liquid water remaining in the condenser 22 at the lowest position in the circuit or water liquefied from the gas phase as shown in FIG. 7B. The heated water W is collected by gravity. However, most of the heated water remaining in the heater 28 remains as it is.

  Therefore, since most of the liquid refrigerant RL is concentrated in the condenser 22 in the heat pump unit 18 at the start after the operation stop, the compressor 21 is prevented from causing liquid compression, oil forming, or the like at the next start-up. The In addition, since the water to be heated is concentrated in the condenser 22 in the steam generation unit 16, a phenomenon in which the condenser 22 does not have a heating target by the refrigerant (start-up phenomenon) can be avoided at startup, and the heat exchanger efficiency can be quickly increased. improves.

  As described above, in the heat pump steam generation device 12 according to the present embodiment, the compressor 21, the condenser 22, the expansion mechanism 24, and the evaporator 26 are connected in an annular shape, and the evaporator 26 recovers heat from the external heat source. A heat pump unit 18 and a steam generation unit 16 that supplies heated water to the condenser 22 and heats the heated water with a refrigerant to generate steam, and includes a discharge side of the compressor 21 and an inlet of the condenser 22. A check valve 30 is provided in the refrigerant pipe 27 a that connects between the two sides to prevent the refrigerant from flowing backward from the condenser 22 to the compressor 21 when the compressor 21 is stopped.

  Therefore, in the heat pump type steam generator 12, since the backflow of the refrigerant from the condenser 22 to the compressor 21 is prevented by the check valve 30 when the operation is stopped, for example, immediately after the operation is stopped, the condenser 22 and the expansion mechanism 24 It can be avoided that the refrigerant in the middle flows back to the compressor 21 and a large amount of refrigerant remains in the compressor 21 and the expansion mechanism 24, and a large amount of refrigerant can be stored in the condenser 22 when stopped. Thereby, at the time of starting after the operation is stopped, liquid refrigerant liquefied by the refrigerant pipe 27e on the suction side of the compressor 21 is sucked into the compressor 21, and a large amount of refrigerant is contained in the refrigerating machine oil in the compressor 21. Generation | occurrence | production of malfunctions, such as oil forming by melting, can be suppressed. Further, since the refrigerant is collected in the condenser 22 at the time of stopping, the refrigerant collected in the condenser 22 may be circulated at the time of activation. That is, since the place where the refrigerant is accumulated at the time of start-up can be predicted, the operation speed of the compressor 21 and the opening degree of the expansion mechanism 24 can be controlled smoothly, and stable start-up operation by appropriate superheat degree control becomes possible. Moreover, immediately after the operation of the apparatus is stopped, the heated water in the steam generator 16 returns to the condenser 22, so that the refrigerant in the condenser 22 is likely to be vaporized and more likely to flow back to the compressor 21. The check valve 30 can reliably prevent this backflow.

  In particular, in the present embodiment, a refrigerant having a characteristic that has a boiling point in the operating temperature range of the heat pump steam generator 12 at atmospheric pressure is used. That is, when such a refrigerant is used, the refrigerant in the heat pump unit 18 is liquefied depending on the ambient temperature when the operation of the apparatus is stopped, and the specifications such as the above-described liquid compression and oil forming are likely to occur. . However, since the heat pump type steam generator 12 is provided with the check valve 30 in the refrigerant pipe 27a that connects the discharge side of the compressor 21 and the inlet side of the condenser 22, Generation | occurrence | production of the malfunction of the compressor 21 can be avoided.

  In the heat pump steam generator 12, since the on / off valve 31 is provided between the outlet side of the condenser 22 of the heat pump unit 18 and the expansion mechanism 24, the on / off valve 31 is controlled to be closed when the operation of the apparatus is stopped. A large amount of refrigerant can be reliably trapped in the condenser 22 (and the heater 28). Thereby, generation | occurrence | production of malfunctions, such as liquid compression of the compressor at the time of starting, can be avoided more reliably, and the stable starting operation can be performed.

  In the heat pump steam generator 12, when the operation is stopped, the on-off valve 31 is closed and the compressor 21 is driven and controlled under the control of the control unit 20, whereby the refrigerant in the heat pump unit 18 is transferred to the condenser 22. Execute the pump down operation to be introduced. Thereby, the refrigerant | coolant in the expansion mechanism 24, the evaporator 26, the compressor 21, and the refrigerant | coolant piping 27 can be forcedly integrated to the condenser 22 at the time of a driving | operation stop. As a result, the occurrence of the malfunction of the compressor 21 as described above can be avoided more reliably.

  In the heat pump steam generator 12, the condenser 22 is installed at a lower position than the water vapor separator 34 in the steam generator 16. As a result, the liquid-phase water accumulated in the water vapor separator 34 during operation is concentrated to the condenser 22 when stopped, so that the condenser 22 has insufficient air to be heated by the refrigerant (heated water) at the time of startup. The soaking phenomenon can be avoided and the heat exchanger efficiency can be improved promptly. Moreover, since the level of the liquid phase water is stably held in the condenser 22 even during operation (see FIG. 7A), air-operated operation in which there is a shortage of heating targets by the refrigerant during operation is also suppressed. The Thereby, it is suppressed that a refrigerant | coolant becomes high pressure too much, and the operating efficiency of an apparatus improves. Moreover, by arranging the condenser 22 having a relatively large weight among the devices constituting the heat pump type steam generating device 12 at a low position, the center of gravity of the entire device can be lowered, and the vibration resistance performance is improved. In addition, the workability of the assembly work is improved.

  Further, in the steam generation unit 16, the condenser 22 is installed at a lower position than the heater 28. Accordingly, the water to be heated is smoothly supplied from the heater 28 to the condenser 22 during operation of the apparatus, and the water to be heated in the heater 28 can be concentrated to the condenser 22 to some extent when the apparatus is stopped.

  In the heat pump steam generator 12, the condenser 22 is installed at a lower position than the evaporator 26 in the heat pump unit 18. As a result, the refrigerant accumulated in the evaporator 26 when the operation of the apparatus is stopped can be more smoothly collected into the condenser 22.

  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 12 Heat pump type steam generation apparatus 14 Case 16 Steam generation part 17 Hot water supply part 18 Heat pump part 20 Control part 21 Compressor 21m Motor 22 Condenser 24 Expansion mechanism 26 Evaporator 27a-27e Refrigerant piping 28 Heater 30 Check valve 31 On-off valve 32a Water supply pipe 32b Circulation pipe 32c Steam pipe 32d Delivery pipe 34 Steam separator 37 Water supply pump 40 Door 50, 52 Refrigerant inlet port 51 Refrigerant outlet port 54 Water inlet port 55, 56 Water outlet port RL Liquid refrigerant W Heated water

Claims (7)

A compressor, a condenser, an expansion mechanism, and an evaporator connected in an annular shape, and a heat pump unit that recovers heat from an external heat source in the evaporator;
A steam generator that supplies heated water to the condenser and heats the heated water with a refrigerant to generate steam;
A heat pump type steam generator comprising:
A refrigerant pipe connecting the discharge side of the compressor and the inlet side of the condenser is provided with a valve for preventing a reverse flow of the refrigerant from the condenser to the compressor when the compressor is stopped. A heat pump type steam generator characterized by the above. In the heat pump type steam generator according to claim 1,
The heat pump type steam generating apparatus, wherein the refrigerant has a characteristic of having a boiling point in an operating temperature range of the heat pump type steam generating apparatus at atmospheric pressure. In the heat pump type steam generator according to claim 1 or 2,
An on-off valve is provided between the outlet side of the condenser of the heat pump unit and the expansion mechanism. In the heat pump type steam generator according to claim 3,
A control unit that performs a pump-down operation for introducing the refrigerant of the heat pump unit into the condenser by controlling the closing of the on-off valve and driving the compressor when the heat pump steam generator is stopped. A heat pump steam generator characterized by comprising: In the heat pump type steam generator according to any one of claims 1 to 4,
The steam generation unit includes a water supply path for supplying heated water to the condenser, and a gas-liquid two-phase flow generated when the heated water is heated by the refrigerant in the condenser. A water vapor separator for separating the water vapor, a circulation path for circulating the separated water to the condenser together with heated water from the water supply path, and a delivery path for sending the water vapor separated by the water vapor separator to the outside. And
The heat pump type steam generator characterized in that the condenser is installed at a lower position than the water vapor separator. In the heat pump type steam generator according to any one of claims 1 to 5,
Between the condenser of the heat pump unit and the expansion mechanism, heat exchange is performed to exchange heat between the refrigerant exiting the condenser and the water to be heated before being introduced into the condenser flowing through the water supply path. Vessel is provided,
In the steam generation part, the condenser is installed at a lower position than the heat exchanger. In the heat pump type steam generator according to any one of claims 1 to 6,
In the heat pump unit, the condenser is installed at a lower position than the evaporator.

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