JP4992346B2 - Heat pump system, shaft sealing method of heat pump system - Google Patents

Description

  The present invention relates to a heat pump system and a shaft sealing method of the heat pump system.

  As for the heat pump system, as described in Patent Document 1, for example, a technique for returning the lubricant flowing out to the refrigerant circuit to the compressor is disclosed.

JP 2002-333220 A

  In the technique described in Patent Literature 1, the lubricating oil leaked into the refrigerant is collected and returned to the compressor. However, lubricating oil that cannot be recovered remains mixed in the refrigerant.

  An object of the present invention is to provide a highly reliable heat pump system and a shaft seal method of the heat pump system by suppressing leakage of bearing lubricant of the compressor into the heat pump working fluid.

In order to achieve the above object, the present invention provides a heat pump system comprising a heat exchanger that exchanges heat between a heat source and a working fluid, and a compressor that compresses the working fluid, wherein the working fluid is water or steam. includes bearing two systems of lines to purge the compressor, the two purge flow body through the one system of the systems and steam, the compressor main flow flowing purge gas, a portion of the compressor main The purge fluid flowing through the other bearing of the two systems is air, the purge gas flowing into the bearing is air, and the purge flows toward the bearing. Water vapor, which is a fluid, is combined with air, which is the purge fluid that flows toward the main flow of the compressor, and discharged to the outside of the compressor .

ADVANTAGE OF THE INVENTION According to this invention, while suppressing the leakage of the bearing lubricating oil of a compressor to the heat pump working fluid, it can suppress that water etc. mix in a bearing lubricating oil system, and can improve reliability. Play. In the heat pump system of the present invention, the purge steam is steam obtained by extracting a part of the mainstream steam of the compressor. With this configuration, it is not necessary to newly install a purge steam supply system, and the system can be simplified and reduced in cost.

  First, a technical description of a system using water or steam as a working fluid in an industrial heat pump will be given. When supplying energy to heat utilization equipment using an industrial heat pump, there is a technology that uses hot water or cold water as a working fluid. The inventors have repeatedly studied under the technical background of improving the performance of the steam compressor, and found that the amount of energy that can be transported per medium weight can be dramatically improved if the working fluid of the heat pump system is steam. . Furthermore, in this case, it has also been found that if the working fluid is set to a negative pressure, heat from the outside can be taken in very efficiently.

  However, since the atmospheric pressure of the bearing portion of the compressor is about atmospheric pressure, when the working fluid is negative pressure and an oil bearing is used for the compressor bearing, there is a concern that the bearing lubricant is mixed into the working fluid. Therefore, it is desirable to improve reliability by suppressing the mixing of bearing lubricating oil into the compressor mainstream in consideration of the efficiency of the heat pump system.

Next, the present invention will be specifically described with reference to the drawings.
(First embodiment)
A first embodiment of the present invention will be described with reference to FIGS. FIG. 1 is a configuration diagram of a heat pump system according to a first embodiment of the present invention. In this embodiment, a heat pump system that uses one four-stage steam compressor as a plurality of compression means will be described as an example. In this case, between the plurality of compression means is between the stages of the steam compressor, and the inlet and outlet of the plurality of compression means are the inlet of the first stage of the steam compressor and the fourth stage, respectively. It means the exit part.

  The heat pump system shown in FIG. 1 includes an evaporator 4 that evaporates supplied water by heat exchange with an external high-temperature heat source 20, and a vapor compressor 1 that compresses and discharges evaporated water vapor. The steam compressor 1 includes four stages, a first stage 11, a second stage 12, a third stage 13, and a fourth stage 14. The steam compressor 1 is driven by a motor 3 connected via a shaft 2. Further, a humidifier 81 is installed on the inlet side of the steam compressor 1, and between the first stage 11 and the second stage 12 of the steam compressor constituting the steam compressor 1, the second stage 12 and the third stage 13. Between the third stage 13 and the fourth stage 14, humidifiers 82, 83, 84 are respectively installed. Each humidifier cools the working fluid by spraying water supplied from the pump 80. It should be noted that a humidifier may be provided between each stage even when the stage of the steam compressor is other than four stages.

  Next, the flow of the working fluid in the heat pump system of the present embodiment will be described. The supplied water 40 is decompressed by the expander 9 that expands the liquid, and is supplied as low-pressure water 41 to the evaporator 4 that is a heat exchanger that exchanges heat between the heat source and the working fluid. The low-pressure water 41 supplied to the evaporator 4 evaporates by exchanging heat with the external high-temperature heat source 20 and becomes superheated steam 42. The superheated steam 42 is supplied to the humidifier 81, cooled to about the saturation temperature by the spray of water supplied from the pump 80, and becomes the saturated steam 43 to be supplied to the steam compressor 1. As the saturated steam 43 passes through the first stage 11 of the steam compressor 1, the pressure and temperature rise and become superheated steam 44. The superheated steam 44 is supplied to the humidifier 82, cooled to about the saturation temperature by water spray, and supplied as the saturated steam 45 to the second stage 12. When the saturated steam 45 is compressed in the second stage 12, the pressure and temperature rise to become superheated steam 46, supplied to the humidifier 83, and sprayed with water supplied from the pump 80 to the saturation temperature level. Cooled to become saturated steam 47. The saturated steam 47 is supplied to the third stage 13, and the temperature is raised and raised to become superheated steam 48. The superheated steam 48 is cooled to about the saturation temperature by water injection in the humidifier 84 and supplied to the fourth stage 14 as the saturated steam 49. The saturated steam 49 is compressed in the fourth stage 14 and finally discharged as high-temperature and high-pressure superheated steam 50.

  Here, the state of the working fluid in the heat pump system of the present embodiment will be described in detail. In the present embodiment, the supplied water 40 is assumed to be water having a pressure of about 0.5 MPa and a temperature of about 120 ° C. The water 40 becomes decompressed water 41 having a pressure of about 0.02 MPa, a temperature of about 60 ° C., and a mass flow rate of about 1.6 kg / s by the expander 9. The depressurized water 41 obtains latent heat of vaporization by heat exchange with the external high-temperature heat source 20 at about 80 ° C., and changes in phase from the liquid phase to the gas phase to become superheated steam 42 at about 65 ° C. The superheated steam 42 flows into the humidifier 81 and is cooled by being deprived of latent heat of vaporization by about 0.05 kg / s of water sprayed here, and is cooled to about 60 ° C. which is a saturation temperature. And supplied to the steam compressor 1. The saturated steam 43 is compressed to a predetermined pressure ratio of about 2.4 by the first stage 11 and becomes superheated steam 44 having a pressure of about 0.05 MPa and a temperature of about 150 ° C. The superheated steam 44 is cooled to about 80 ° C. which is a saturation temperature by being sprayed with about 0.1 kg / s of water by the humidifier 82, and is supplied to the second stage 12 as the saturated steam 45. The saturated steam 45 is compressed by the second stage 12 to a predetermined pressure ratio of 2.2, and becomes superheated steam 46 having a pressure of about 0.11 MPa and a temperature of about 170 ° C. The superheated steam 46 is cooled to about 100 ° C., which is the saturation temperature, by the about 0.1 kg / s of water sprayed by the humidifier 83, taking latent heat of evaporation, and becomes the saturated steam 47. The saturated steam 47 is compressed to a predetermined pressure ratio of about 2.0 by the third stage 13, and becomes superheated steam 48 having a pressure of about 0.22 MPa and a temperature of about 180 ° C. The superheated steam 48 flows into the humidifier 84, and 0.1 kg / s of water sprayed there deprives the latent heat of vaporization to cool to 120 ° C., which is a saturation temperature, to become saturated steam 49, which is the fourth stage 14. Flows into. The saturated steam 49 is compressed by the fourth stage 14 to a predetermined pressure ratio of 1.8, and finally, the superheated steam 50 having a pressure of about 0.40 MPa and a temperature of about 190 ° C. can be obtained. The superheated steam 50 is used as an industrial heat source in a heat utilization facility such as a paper manufacturer, a food factory, a district air conditioner, and a chemical factory.

  In this embodiment, since the working fluid of the compressor is water vapor, the amount of energy that can be transported per fluid weight can be dramatically improved as compared with the case of using hot water or cold water. Therefore, the installation location of the heat pump system is not limited to a range close to the heat utilization facility.

  The heat pump takes in atmospheric heat, waste heat, and the like and uses them effectively. In this embodiment, the pressure of water, which is a heat pump working fluid, is reduced to a negative pressure by the expander, so that the phase of water can be changed to water vapor even when the temperature of the external high-temperature heat source is relatively low. Therefore, it is possible to obtain two effects, that is, an effect that heat from the heat source can be efficiently taken in and an effect that a heat source that has not been effectively used because the temperature is low can also be used.

  However, in this case, the water vapor that is the working fluid of the compressor also has a negative pressure. A compressor operated with a negative working fluid is generally unreliable due to the influence of leakage of bearing lubricant. In this embodiment, as described later, a purge mechanism is provided in the bearing portion to suppress leakage of the bearing lubricating oil into the working fluid and improve reliability. That is, the heat pump system of the present embodiment achieves both high reliability and excellent efficiency.

  FIG. 2 is a diagram schematically illustrating the compressor structure of the heat pump system of the present embodiment. As shown in FIG. 2, the steam compressor 1 includes a stationary system including stationary members 101, 102, 103, 104, 105, 106, stationary blades 111, 112, 113, 114, a shaft 2, rotors 121, 122, The rotating system includes 123 and 124 and moving blades 131, 132, 133, and 134. The stationary system and the rotating system are connected via bearings 61 and 62. The first stage 11 including the moving blade 131 and the stationary blade 111, the second stage 12 including the moving blade 132 and the stationary blade 112, the third stage 13 including the moving blade 133 and the stationary blade 113, the moving blade 134 and the stationary blade 114. Humidifiers 81, 82, 83, and 84 are installed in front of each of the fourth stages 14, and water is supplied from a pump 80 to each of the humidifiers. In this embodiment, the humidifier is assumed to be a spray nozzle. However, any other type of humidifier may be used as long as it is a mechanism capable of spraying water in a mist form.

  FIG. 3 shows an enlarged view of the bearing portion in the compressor structure of the heat pump system of the present embodiment shown in FIG. A lubricant is supplied to the bearing 61 from the pump 70 through the pipe 71, and the lubricant is collected through the pipe 72. A space 151 partitioned by fins 153 and 155 is provided between the working fluid flow path and the bearing 61. A pipe 160 is connected to the space 151 so that a fluid can be supplied from outside the space 151. In the present embodiment, the fin plays a role of sealing the gap between the shaft 2 as a rotating body and the stationary member 101 as a stationary body. The flow rate of the fluid passing between the space 151 and the bearing portion and between the space 151 and the compressor main flow is suppressed by the sealing effect of the fins 153 and 155. Due to this sealing effect, the pressure in the space 151 is maintained within a predetermined range by appropriately adjusting the pressure of the fluid supplied from the pipe 160.

  In this embodiment, oil is used as the lubricant. If oil leaks into the flow path of the working fluid for some reason, the blades and the flow path may be corroded. In order to suppress this, in this embodiment, the space 151 is purged with a high-pressure fluid to prevent oil from leaking into the flow path of the working fluid. The purge means a shaft seal for preventing the lubricating oil supplied to the bearing portion from leaking out from the bearing portion. Specifically, by supplying a purge fluid having a pressure higher than the pressure of the lubricating oil of the bearing 61 to the space 151, the flow of the fluid from the bearing 61 to the space 151 is suppressed, and the lubricating oil flows into the purge system and the compressor mainstream. It is suppressed from mixing in.

  In a general turbomachine, high-temperature and high-pressure air is used as a purge gas. However, since the compressor working fluid is water vapor in this embodiment, when air flows into the main flow of the compressor using air as the purge gas, the water vapor and air are mixed in the main flow of the compressor. Water vapor and air, which are different gases, have different heat capacities. Since the distance between the portion where the purge gas flows into the main flow and the compressor blade is about several times the chord length, the purge gas collides with the compressor blade before completely diffusing into the main flow. The blade must take into account deformation due to thermal elongation, and if there is a part where the temperature changes locally, the reliability of the blade is low. From the above, when air flows into the main flow of the compressor using air as the purge gas, the gas with a biased heat capacity collides with the blade and the temperature changes intensively only for a part of the blade. Is unreliable.

  Therefore, in this embodiment, water vapor is supplied as purge gas to the purge space of the bearing portion. By making the mainstream gas and purge gas of the compressor into water vapor, which is the same kind of gas, it is possible to suppress the occurrence of local temperature changes of the blades and improve the reliability of the blades. Further, considering that the purge gas leaks into the main stream, it is preferable to use water vapor as the purge gas rather than air. This is because if the steam is used, the reduction of the mass flow rate of the compressor mainstream can be suppressed and the efficiency can be improved.

  In this embodiment, since the bearing is exposed to the atmosphere, the atmospheric pressure of the bearing portion is atmospheric pressure. Therefore, it is assumed that the pressure of the steam for purge supplied to the bearing space 151 of the bearing 61 on the upstream side in the flow direction of the working fluid is about 0.12 MPa slightly higher than the atmospheric pressure and the temperature is about 150 ° C.

  On the other hand, when the lubricating oil of the bearing 62 on the downstream side in the flow direction of the working fluid is mixed in the main flow, it can be considered that it is mixed from the gap between the stationary member 106 and the rotor 124. However, the pressure of the mainstream steam of the compressor at this position is much higher than atmospheric pressure. Therefore, this high-pressure mainstream steam plays the role of purge steam. Since this configuration can be regarded as a purge mechanism, the possibility of the lubricating oil mixing from the bearing 62 into the main flow is extremely low. That is, the bearing 62 may or may not be provided with a new purge mechanism like the bearing 61.

  It is also possible to configure the system in this embodiment using a single fluid other than water. However, it is desirable to apply water in that it is inexpensive, easy to obtain, harmless, and can be used as a refrigerant in a heat pump system.

  Here, the system advantage of the heat pump of this embodiment will be described. Compared to a heat pump system that does not involve cooling due to humidification of the working fluid (hereinafter referred to as a comparative example), in the heat pump system of this embodiment that cools the water vapor that is the working fluid by humidification, the heat transport performance is dramatically improved. The performance of the heat pump system is evaluated by a coefficient of performance (COP). The COP is a value obtained by dividing the available energy by the power of the compressor, and represents the ratio between the amount of heat pumped up by the heat pump and the compression work of the compressor used to pump it up.

  Since the compression power of the steam compressor 1 in the heat pump system of the present embodiment is about 1.2 MW in total and the energy held in the form of the superheated steam 50 is about 5.2 MW, the heat pump coefficient of performance is about 4.3. It is. On the other hand, in the case of the heat pump as the comparative example described above, assuming that the stage efficiency and the stage head are the same as those of the steam compressor, the cooling ratio of the compressor is reduced to about 11 because the working medium is not cooled. To do. In the heat pump of this embodiment, the compression ratio of the compressor is about 20. The reason why the compression ratio is low when the working medium is not cooled is that the pressure rise with respect to the same head is small because the temperature of the water vapor flowing into each stage is high. This is due to the nature of the gas that the density decreases as the temperature rises, and the lower the density, the more compression power is required to pressurize to a predetermined pressure.

  The pressure ratio is determined by user specifications. Therefore, in order to compare the performance, it is necessary to make the pressure ratio of the comparative example the same as that of the present embodiment in which cooling by humidification is performed. In order to increase the compression ratio of the comparative example to the same level as when cooling by humidification, it is necessary to add the number of stages. However, the addition of the number of stages is accompanied by an increase in compression power and an increase in the number of parts. That is, the heat pump system of the comparative example that does not cool the working fluid has a poor coefficient of performance and high cost as compared with the one of the present embodiment. That is, the heat pump system of the present embodiment realizes high performance and low cost by cooling the water vapor by humidification.

  Although the present embodiment shows an example of cooling by humidification, as described above, the same kind of effect can be obtained as long as the method can reduce the temperature of the water vapor that is the working fluid. Therefore, you may use cooling means other than humidification cooling, such as cooling a working medium with a heat exchanger, for example.

If there is an existing heat pump system including an expander that expands the liquid that is the working fluid, an evaporator that evaporates the expanded liquid by heat from an external high-temperature heat source, and a compressor that compresses the evaporated gas, By remodeling this, a heat pump system having the same effect as the heat pump system of the present embodiment can be obtained. This is the same configuration as the heat pump system of the present embodiment by additionally providing a supply means for supplying water as working fluid to the expander and a purge means for sealing the bearing portion of the compressor to the existing heat pump system. Can be realized.
(Second embodiment)
A second embodiment of the present invention will be described with reference to FIG. 4, FIG. 5, and FIG. In this embodiment, for the sake of simplicity, a heat pump system using one single-stage compressor will be described as an example. However, the configuration of the present embodiment can be similarly applied to those using a plurality of compressors and those using a plurality of stages of compressors.

  The overall configuration of the heat pump system of this embodiment will be described with reference to FIG. FIG. 4 is a configuration diagram of the heat pump system according to the first embodiment of the present invention. The compressor 501 is connected to an electric motor 506 that is a drive source via a shaft 507 designated by the first bearing 509 and the second bearing 510. Lubricating oil is supplied to the first bearing 509 and the second bearing 510 by a lubricating oil supply pipe 517 connected to the lubricating oil device 516, and the lubricating oil that has played a role in the bearing is a lubricating oil drain pipe 518. To the lubricating oil device 516. The lubricating oil device 516 has a smoke exhaust fan (not shown).

  The water supplied from the water tank 502 is introduced into the expander 503 through the supply pipe 511 and depressurized. The depressurized water is evaporated by heat exchange with the external heat source 505 in the evaporator 504. The steam generated by the evaporator 504 is supplied to the compressor 501. This steam is heated and pressurized by the compressor 501, and is led to the next process (for example, steam utilization equipment) through the pipe 514 as high-temperature and high-pressure steam.

  Next, the compressor 1 of this embodiment will be described in detail with reference to FIG. FIG. 5 shows a partially enlarged view of the heat pump system of the present embodiment.

  The mainstream steam supplied into the compressor 1 is led from the compressor discharge 541 to the pipe 514 through the impeller inlet 540a, the impeller 520, the impeller outlet 540b, and the diffuser 521. An impeller 520 that is a rotating body is connected to a shaft 507. A casing 522 and a bearing box 523 which are stationary bodies are provided outside the shaft 507. In the casing 522, a first labyrinth seal 530, a second labyrinth seal 531, and a third labyrinth seal 532 are arranged in series in the axial direction, and between the first labyrinth seal 530 and the second labyrinth seal 531. A second cavity 534 is provided between the first cavity 533, the second labyrinth seal 531, and the third labyrinth seal 532. The first cavity 533 is connected to a pipe 514 near the compressor discharge 541 via a purge steam supply port 543 and a purge steam supply pipe 542 provided in the casing 522.

  A gap is inevitably formed between rotating members such as the impeller 520 and the shaft 507 and stationary members such as the casing 522 and the bearing box 523. The gap communicates between the compressor mainstream (impeller outlet 540 b) and the bearing 509. In order to prevent the bearing lubricating oil from leaking into the compressor mainstream through this gap, the heat pump system of the present embodiment is provided with a shaft sealing means for purging the bearing. Hereinafter, the purge mechanism which is the shaft sealing means will be described. In this embodiment, the labyrinth seal is used as the gap sealing means, but other sealing means such as a brush seal may be adopted.

  Between the casing 522 to which the first labyrinth seal 530 is attached and the impeller 520, a steam return flow path 537 communicating with the impeller outlet 540b is formed. The second cavity 534 is connected to a vacuum pump (not shown) via a discharge port 544 and a discharge pipe 545 provided in the casing 522. An oil drain 535 is installed between the third labyrinth seal 532 and the first bearing 509, and a third cavity 536 is formed between the third labyrinth seal 532 and the oil drain 535. The air is communicated with the atmosphere through a purge air supply port 546 provided in the casing 522.

  Next, the flow of fluid around the labyrinth seal portion will be described with reference to FIG. FIG. 6 shows a partially enlarged view of the heat pump system of the present invention.

  The mainstream steam 550 of the compressor 1 is heated and pressurized by passing through the impeller 520 and the diffuser 521, and flows to the pipe 514 through the compressor discharge 541. A part of the steam flowing through the pipe 514 is extracted and supplied as purge steam 552 from the purge steam supply pipe 542 to the purge steam supply hole 543. This extracted steam is branched in the first cavity 533 to become a branched steam flow 553 that passes through the first labyrinth seal 530 and a branched steam flow 554 that passes through the second labyrinth seal 531. On the other hand, the purge air supply port 546 that has sucked the air flow 555 from the atmosphere is branched by the third cavity 536, and the branched air flow 557 that passes through the oil drain 535 and the branched air flow that passes through the third labyrinth seal 532. 556. This branched air flow 556 joins with the aforementioned branched vapor flow 554 in the second cavity 534 and is guided to the vacuum pump through the discharge port 544.

  When starting up, the inside of the compressor 1 is depressurized to about 0.02 MPa in advance by a vacuum pump (not shown). Further, a vacuum pump (not shown) is operated to suck air in the second cavity 534 through the discharge pipe 45. After starting the lubricating oil device 516 and supplying lubricating oil to the first bearing 509 and the second bearing 510, the motor 506 rotates the shaft 507 and the impeller 520 to about 50,000 rpm. The water from the water tank 502 is led to the expander 503 and depressurized, and is evaporated by exchanging heat with the external heat source 505 at about 80 ° C. in the evaporator 504, and as steam at about 60 ° C., the impeller inlet 540 a of the compressor 501. To be supplied. The steam is pressurized to about 0.04 MPa in the process of passing through the rotating impeller 520 and the stationary diffuser 521. The pressurized steam passes through the exhaust pipe 514 and proceeds to the next step. A part of the steam is supplied as extracted steam to the first cavity 533 through the seal steam pipe 542 at a pressure of about 0.035 MPa. . Since the pressure at the impeller outlet 540b is about 0.034 MPa, the branch steam flow 553 that leaks into the main stream from the first cavity 533 through the steam return channel 537 is very small. On the other hand, since the internal pressure of the second cavity 534 is about 0.03 MPa, the branch vapor flow 554 that is the flow from the first cavity 533 to the second cavity 534 is also very small. That is, the amount of steam extracted from the main stream as the seal steam 552 is small, and the amount of steam flowing out from the return flow path 537 to the impeller outlet 540b is also small. Therefore, the influence of the mainstream steam extraction and the purge steam inflow to the mainstream steam on the compressor mainstream is small. In the heat pump system of the present embodiment, leakage of mainstream steam from the impeller outlet 540b, which is an adjacent portion of the rotating body and the stationary body, can be suppressed by such a configuration.

  The lubricating oil device 516 is sucked at about −300 mmAq by an attached smoke exhaust fan (not shown), and the internal pressure of the bearing portion is almost the same (about 0.100 MPa). The air flow 555 having an atmospheric pressure of about 0.103 MPa passes through the purge air supply port 546 and is sucked into the third cavity 536 having about 0.102 MPa. A part of the air flow 555 flows into the lubricating oil device 516 through the oil drain 535 as a branched air flow 557. The remainder of the air flow 555 becomes a branched air flow 556 that flows toward the second cavity 534, merges with the aforementioned branched vapor flow 554, and is led to the vacuum pump side (0.02 MPa) side through the discharge port 544. . With such a configuration, mixing of steam into the first bearing 509 is suppressed. Since relatively low-temperature purge air is guided into the first bearing 509, leakage of the lubricating oil to the impeller 520 side can be suppressed, and temperature rise of the bearing itself can be suppressed.

  The heat pump system of this embodiment includes a system for purging the bearing 509 of the compressor 501 with water or steam as the working fluid, and at least one purge fluid is steam, and the purge gas flowing into the main flow of the compressor 501 is steam. It is constituted so that. By configuring in this way, it is possible to prevent the lubricating oil of the bearing 509 from being mixed into the main flow of the compressor, and further, to make the main flow fluid of the compressor and the purge fluid flowing into the main flow into the same kind of water vapor. Therefore, it is possible to suppress the occurrence of local temperature changes of the blades and to improve the reliability of the compressor. Furthermore, compared with the case where air flows into the main flow of the compressor, a decrease in the main flow mass flow rate can be suppressed, which is advantageous in terms of the thermal efficiency of the system.

  Further, in the heat pump system of this embodiment, at least another kind of purge fluid is air, and the purge gas flowing into the bearing 509 is air. With this configuration, it is possible to suppress water and the like from being mixed into the bearing lubricating oil system, and a device for removing water from the lubricating oil becomes unnecessary, and the system can be simplified and the cost can be reduced.

  In the heat pump system of the present embodiment, the bearing purge mechanism has a steam supply port 543 for supplying purge steam to the compressor discharge 541 side of the gap communicating with the compressor discharge 541 and the bearing 509, and the bearing 509 side of the gap An air supply port 546 for supplying purge air to the air supply port 546 is provided, and a discharge port 544 for discharging purge steam and purge air from the gap is provided between the steam supply port 543 and the air supply port 546. With this configuration, it is possible to realize a system in which the purge gas flowing into the main flow of the compressor 501 becomes water vapor and the purge gas flowing into the bearing 509 becomes air, and as described above, improved reliability and high efficiency And cost reduction.

  In the heat pump system of this embodiment, the bearing purge mechanism has a steam supply port 543 for supplying purge steam to the gap, an air supply port 546 for supplying purge air to the gap, and exhausts purge steam and purge steam from the gap. The purge steam is configured to flow from the steam supply port 543 to the discharge port 544 or the main compressor, and the purge air flows from the air supply port 546 to the discharge port 544 or the bearing 509. By comprising in this way, the inflow to the gap | interval of the mainstream steam of a compressor and a bearing lubricating oil can be suppressed, and the reduction | decrease in the amount of lubricating oil in a compressor mainstream steam amount and a lubricating oil system | strain can be suppressed. Moreover, mixing of lubricating oil into the compressor mainstream, mixing of steam into the lubricating oil system, and inflow of lubricating oil into the purge fluid discharge system can be suppressed, and the reliability of the system can be improved.

  In the heat pump system of the present embodiment, the pressure of the purge steam supplied to the steam supply port 543 is higher than the pressure of the compressor mainstream steam at the communication portion to the gap, and the pressure of the purge air supplied to the air supply port 546 is the bearing. The pressure of the discharge port 544 is higher than the atmospheric pressure of 509, and is lower than the pressure of the compressor mainstream steam at the communicating portion to the gap and the atmospheric pressure of the bearing 509. With this configuration, the purge steam can flow to the discharge port 544 or the compressor main flow, and the purge air can flow to the discharge port 544 or the bearing 509. As described above, the compressor main flow steam amount and A decrease in the amount of lubricating oil in the lubricating oil system can be suppressed, and the reliability of the system can be enhanced.

  In the heat pump system of the present embodiment, the purge steam is steam obtained by extracting a part of the mainstream steam of the compressor 501. With this configuration, it is not necessary to newly install a purge steam supply system, and the system can be simplified and the cost can be reduced.

  In the heat pump system of this embodiment, the discharge port 544 is connected to a vacuum pump. With this configuration, the pressure at the discharge port 544 can be set low, the inflow of lubricating oil into the compressor mainstream and the inflow of steam into the lubricating oil system can be suppressed, and the reliability of the system can be improved. .

  The bearing purge mechanism of the heat pump system of the present embodiment has a labyrinth seal or a brush seal. By providing the labyrinth seal or brush seal in addition to the bearing purge mechanism, the flow rate of the purge fluid itself flowing through the gap can be reduced, and the reliability and efficiency of the system can be further improved.

The block diagram of the heat pump system which is one of embodiment of this invention is shown. The compressor structure figure of the heat pump system of this invention is shown. The enlarged view of the bearing part of the compressor of the heat pump system of this invention is shown. 1 shows a structural diagram of a heat pump system that is one embodiment of the present invention. FIG. The partial enlarged view of the heat pump system which is one of the embodiment of this invention is shown. The partial enlarged view of the heat pump system which is one of the embodiment of this invention is shown.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Steam compressor, 2 ... Shaft, 3 ... Motor, 4 ... Evaporator, 9 ... Expander, 11 ... Steam compressor 1st stage, 12 ... Steam compressor 2nd stage, 13 ... Steam compressor 3rd stage 14 ... Steam compressor fourth stage, 20 ... External high-temperature heat source, 40, 41 ... Water, 42, 44, 46, 48, 50 ... Superheated steam, 43, 45, 47, 49 ... Saturated steam, 61, 62, 509, 510 ... bearing, 70, 80 ... pump, 71, 72, 160, 161, 163, 542, 545 ... piping, 81, 82, 83, 84 ... humidifier, 91 ... condenser first stage, 92 ... condensation Second stage, 93 ... Third stage of condenser, 94 ... Fourth stage of condenser, 100 ... Casing, 101, 102, 103, 104, 105, 106 ... Static member, 111, 112, 113, 114 ... Stator blade 121, 122, 123, 124 ... rotor, 131, 132, 13 , 134 ... Rotor blades, 151, 152 ... Space, 153, 154, 155 ... Fins, 170, 172 ... Control valve, 180 ... Control device, 501 ... Compressor, 507 ... Shaft, 516 ... Lubricating oil device, 520 ... Impeller 521 ... Diffuser, 522 ... Casing, 523 ... Bearing box, 530, 531, 532 ... Labyrinth seal, 533, 534, 536 ... Cavity, 535 ... Oil drain, 537 ... Flow path, 540a ... Impeller inlet, 540b ... Impeller outlet 541: Compressor discharge, 543, 546 ... Supply port, 544 ... Discharge port, 550, 552 ... Steam, 553, 554 ... Steam flow, 555, 556, 557 ... Air flow.

Claims (2)

A heat pump system comprising a heat exchanger that exchanges heat between a heat source and a working fluid, and a compressor that compresses the working fluid,
The working fluid is water or steam, and two systems for purging the compressor bearing are provided,
The 2 purge flow body through the one system of the systems and steam, the compressor main flow flowing purge gas, and configured to be water vapor bleed a part of mainstream steam of the compressor,
The purge fluid flowing through the other one of the two systems is air, and the purge gas flowing into the bearing is air,
A heat pump system configured to combine water vapor, which is a purge fluid flowing toward the bearing, with air, which is the purge fluid, which flows toward the main flow of the compressor, and discharge the vapor outside the compressor . A shaft seal method for a heat pump system comprising a heat exchanger for exchanging heat between a heat source and a working fluid, and a compressor for compressing the working fluid,
The working fluid is water or steam, and the purge gas flowing into the compressor main flow is steam, and the bearing of the compressor is sealed with steam, and the steam is the purge gas flowing toward the bearing The shaft is sealed with air, and the air is discharged to the outside of the compressor together with the water vapor that is a purge gas flowing toward the bearing,
A shaft sealing method for a heat pump system, wherein steam obtained by extracting a part of mainstream steam of a compressor is used as the steam.

Images