JP6083509B2 - Water heating system - Google Patents

Description

  The present invention relates to a feed water heating system using a heat pump.

  Conventionally, as disclosed in Patent Document 1 below, a system capable of heating water supplied to a water supply tank (23) of a boiler (24) using a heat pump (12) is known. In addition, the applicant has proposed a feed water warming system in which the efficiency of the heat pump is further improved as compared with this prior art, and has already filed a patent application (Japanese Patent Application No. 2012-79191).

  The water supply warming system in this application includes a heat pump and a water supply tank, and water supplied to the water supply tank via the water supply path is sequentially passed through a waste heat recovery heat exchanger, a supercooler, and a condenser. The waste heat recovery heat exchanger is an indirect heat exchanger between the water supply to the water supply tank via the water supply channel and the heat source fluid after passing through the evaporator, and the supercooler to the water supply tank via the water supply channel Indirect heat exchanger between the water supply and the refrigerant from the condenser to the expansion valve. It is preferable to adjust the amount of water flow to the condenser so that the heat pump is operated during water supply to the water supply tank via the water supply path, and the outlet water temperature of the condenser of the heat pump is maintained at the set temperature.

JP 2010-25431 A (FIGS. 2 and 3)

  The problem to be solved by the present invention is to reduce power consumption by driving a compressor using a steam engine in a feed water heating system using a heat pump.

  The present invention has been made to solve the above problems, and the invention according to claim 1 is characterized in that a compressor, a condenser, an expansion valve, and an evaporator are sequentially connected in an annular manner to circulate a refrigerant, and the evaporation. Heat is pumped from the heat source fluid that is passed through the condenser, and the heat pump that heats the water that is passed through the condenser, the waste heat recovery heat exchanger, the supercooler, and the condenser are passed through the water supply passage in order. A water supply tank, a boiler that heats the water supplied from the water supply tank to steam, and a steam engine that uses the steam from the boiler to generate power, and the waste heat recovery heat exchanger includes the water supply An indirect heat exchanger for supplying water to the water supply tank via a channel and a heat source fluid after passing through the evaporator, the supercooler supplying water to the water tank via the water supply channel, Between the refrigerant from the condenser to the expansion valve A heat exchanger, a water heating system, characterized by driving the compressor by the steam engine.

  According to the first aspect of the present invention, water supplied to the water supply tank via the water supply passage is sequentially passed through the waste heat recovery heat exchanger, the subcooler, and the condenser, while the heat source fluid of the heat pump is evaporated. Through the heat exchanger and the waste heat recovery heat exchanger. The efficiency of the heat pump can be improved by preheating the feed water to the condenser using the heat of the heat source fluid after passing through the evaporator and the heat of the refrigerant after passing through the condenser. Moreover, since the compressor of the heat pump is driven by a steam engine, it is possible to reduce power consumption.

Invention of Claim 2 uses the steam after use with the said steam engine in any one of following (a)-(c), The feed water heating of Claim 1 characterized by the above-mentioned. System.
(A) Steam after use in the steam engine is injected into the water supply channel or the water supply tank, or indirectly exchanges heat with water in the water supply channel or the water supply tank, so that the water supply channel or the water supply water is supplied. Warm the water in the tank.
(B) The steam after use in the steam engine is injected into the heat source fluid or indirectly heat-exchanged with the heat source fluid on the upstream side of the evaporator to heat the heat source fluid.
(C) The steam after use in the steam engine is supplied to the steam using facility as it is or after being pressurized.

  According to invention of Claim 2, using the steam after use with a steam engine, (a) heating the water supply to a water supply tank or the stored water in a water supply tank, or (b) supplying to an evaporator The heat source fluid can be heated, or (c) steam to the steam using facility can be secured.

  According to a third aspect of the present invention, the water is supplied to the water supply tank via the water supply channel, the heat pump is operated, and the outlet side water temperature of the condenser of the heat pump is maintained at a set temperature. The feed water warming system according to claim 1 or 2, wherein the amount of water passing through the vessel is adjusted.

  According to the third aspect of the present invention, the amount of water flow to the condenser (via the water supply channel) is maintained so that the water temperature on the outlet side of the condenser is maintained at the set temperature during the water supply to the water supply tank via the water supply channel. Regardless of the water temperature of the water supply source or the temperature of the heat source fluid, hot water having a desired temperature can be obtained by adjusting the water supply flow rate to the water supply tank. In addition, in order to maintain the outlet water temperature of the condenser at the set temperature, the heat pump is not controlled, but the amount of water flow to the condenser is controlled, so that the heat pump can be operated with a high efficiency and high load, The load can be adjusted according to the water level.

  Invention of Claim 4 is a feed water heating system of any one of Claims 1-3 which controls the steam supply to the said steam engine based on the water level of the said water supply tank. is there.

  According to the fourth aspect of the present invention, the output of the heat pump can be changed by controlling the steam supply to the steam engine based on the water level of the water supply tank.

  Further, the invention according to claim 5 is the water temperature on the condenser outlet side or the compressor outlet side of the heat pump in a state where the water supply flow rate is kept at a predetermined level during the water supply to the water supply tank via the water supply channel. The feed water warming system according to claim 1 or 2, wherein steam supply to the steam engine is controlled based on a refrigerant pressure or a refrigerant temperature.

  According to the fifth aspect of the present invention, the water supply to the water supply tank through the water supply channel, the steam supply to the steam engine is controlled based on the water temperature on the condenser outlet side of the heat pump, and the output of the heat pump is adjusted. Thus, hot water having a desired temperature can be obtained. Moreover, even if it controls based on the refrigerant | coolant pressure or refrigerant | coolant temperature by the side of a compressor, the refrigerant | coolant temperature in a condenser can be maintained as desired, and hot water of desired temperature can be obtained as a result.

  According to the present invention, in a feed water warming system using a heat pump, power consumption can be reduced by driving a compressor using a steam engine.

It is the schematic which shows one Example of the feed water heating system of this invention.

Hereinafter, specific embodiments of the present invention will be described in detail with reference to the drawings.
FIG. 1 is a schematic view showing an embodiment of a feed water warming system 1 of the present invention.

  The feed water warming system 1 of the present embodiment is a system that can heat the feed water to the feed water tank 3 of the boiler 2 with the heat pump 4. The feed water tank 3 that stores the feed water to the boiler 2, and the feed water tank 3 A replenishment water tank 5 for storing water supply, a heat pump 4 for heating water supplied from the replenishment water tank 5 to the water supply tank 3, and a heat source water tank for storing heat source water (for example, waste hot water) as a heat source of the heat pump 4. 6.

  The boiler 2 is a steam boiler, and heats the feed water from the feed water tank 3 into steam. The boiler 2 is typically adjusted in combustion quantity so as to maintain the desired steam pressure. Moreover, the pump 7 provided in the inside of the water supply path from the water supply tank 3 to the boiler 2, or the boiler 2 is controlled so that the boiler 2 may maintain the water level in a can body as desired. The steam from the boiler 2 is sent to various steam-using facilities, but drain (condensed water of steam) from the steam-using facility may be returned to the feed water tank 3. Although details will be described later, there is a steam engine (steam motor) 8 for driving the heat pump 4 as one of the steam use facilities of this type.

  The water supply tank 3 can supply water from the make-up water tank 5 through the heat pump 4 through the water supply passage 9 and can be supplied through the make-up water passage 10 without going through the heat pump 4. By controlling the operation of the water supply pump 11 provided in the water supply channel 9 and the makeup water pump 12 provided in the makeup water channel 10, via either one or both of the water supply channel 9 and the makeup water channel 10, Water can be supplied from the makeup water tank 5 to the water supply tank 3.

  In this embodiment, the feed water pump 11 can control the rotation speed by an inverter. By changing the rotation speed of the water supply pump 11, the water supply flow rate to the water supply tank 3 through the water supply path 9 can be adjusted. On the other hand, the makeup water pump 12 is on / off controlled in this embodiment.

  The makeup water tank 5 stores water supplied to the water supply tank 3. In this embodiment, soft water is used as the water supply to the makeup water tank 5. That is, the soft water from which the water hardness has been removed by the water softener (not shown) is supplied to the makeup water tank 5 and stored. By controlling the water supply from the water softener based on the water level of the makeup water tank 5, the water level of the makeup water tank 5 is maintained as desired.

  The heat pump 4 is a vapor compression heat pump, and is configured by sequentially connecting a compressor 13, a condenser 14, an expansion valve 15, and an evaporator 16 in an annular shape. The compressor 13 compresses the gas refrigerant to a high temperature and a high pressure. The condenser 14 condenses and liquefies the gas refrigerant from the compressor 13. Further, the expansion valve 15 allows the liquid refrigerant from the condenser 14 to pass through, thereby reducing the pressure and temperature of the refrigerant. The evaporator 16 then evaporates the refrigerant from the expansion valve 15.

  Therefore, in the heat pump 4, in the evaporator 16, the refrigerant takes heat from the outside and vaporizes, while in the condenser 14, the refrigerant dissipates heat to the outside and condenses. Using this, in this embodiment, the heat pump 4 draws heat from the heat source water in the evaporator 16, and heats the water in the water supply passage 9 in the condenser 14.

  It is preferable that the heat pump 4 further includes a supercooler 17 between the condenser 14 and the expansion valve 15. The supercooler 17 is an indirect heat exchanger between the refrigerant from the condenser 14 to the expansion valve 15 and the feed water to the condenser 14. The subcooler 17 can supercool the refrigerant from the condenser 14 to the expansion valve 15 by supplying water to the condenser 14, and can supply the refrigerant to the condenser 14 by the refrigerant from the condenser 14 to the expansion valve 15. The water supply can be heated. The refrigerant of the heat pump 4 preferably releases latent heat in the condenser 14 and releases sensible heat in the subcooler 17.

  That is, in the condenser 14, the gas refrigerant is condensed into a liquid refrigerant, and the liquid refrigerant is supplied to the subcooler 17, and the liquid refrigerant is further cooled (supercooled) in the subcooler 17. By separating heat exchangers for refrigerant condensation and supercooling, the heat exchanger can be easily designed, the heat exchanger can be reduced in size with a simple structure, and costs can be reduced. In addition, a general-purpose heat exchanger can be used.

  In addition, in the heat pump 4, an accumulator is installed on the inlet side of the compressor 13, an oil separator is installed on the outlet side of the compressor 13, or the outlet side of the condenser 14 (the condenser 14 and the subcooler 17 A receiver may be installed between the two).

  The compressor 13 of the heat pump 4 is driven by the steam engine 8. In the present embodiment, the compressor 13 of the heat pump 4 is driven only by the steam engine 8, but in some cases, it may be driven by an electric motor in addition to the steam engine 8. In that case, what is necessary is just to adjust the drive ratio of the steam engine 8 and an electric motor suitably.

  The steam engine 8 is a device that generates power using steam. Steam is supplied to the steam engine 8 via a steam supply path 18, and the steam is discharged via a steam exhaust path 19. Steam from the boiler 2 can be used as steam to the steam engine 8.

  A steam supply valve 20 is provided in the steam supply path 18 to the steam engine 8. By switching the opening and closing of the steam supply valve 20, it is possible to switch the operation of the steam engine 8 and thus the heat pump 4 (compressor 13). Further, by adjusting the opening of the steam supply valve 20, the output of the steam engine 8 and thus the heat pump 4 (compressor 13) can be adjusted. Needless to say, the steam supply path 18 from the boiler 2 to the steam engine 8 may be provided with a steam header or a pressure reducing valve as desired. In addition, the steam supply control to the steam engine 8 may be performed by a valve provided in the exhaust steam passage 19 depending on circumstances.

  The steam after use in the steam engine 8 is led out through the exhaust steam path 19 and can be used as follows, for example.

  (A) As shown by the solid line A, the steam from the steam engine 8 is injected into the water supply channel 9 downstream of the condenser 14 in the water supply channel 9, or the water from the water supply channel 9 and the steam engine 8 The steam is indirectly heat-exchanged to heat the water supplied to the water supply tank 3 via the water supply passage 9.

  (B) As shown by a two-dot chain line B, water from the steam engine 8 is injected into the water supply tank 3 or water in the water supply tank 3 and steam from the steam engine 8 are indirectly heat-exchanged to supply water. The stored water in the tank 3 is heated.

  (C) As indicated by a two-dot chain line C, the steam from the steam engine 8 is injected into the heat source water tank 6 or the heat source water in the heat source water tank 6 and the steam from the steam engine 8 are indirectly heat-exchanged. Then, the heat source water in the heat source water tank 6 is heated. However, such heating of the heat source water may be performed not in the heat source water tank 6 but in the heat source supply path 21 from the heat source water tank 6 to the evaporator 16. That is, the steam from the steam engine 8 is injected into the heat source supply path 21 upstream of the evaporator 16 in the heat source supply path 21, or the heat source water in the heat source supply path 21 and the steam from the steam engine 8 are indirectly connected. The heat source water to the evaporator 16 via the heat source supply path 21 may be heated by heat exchange.

  (D) As shown by a two-dot chain line D, the steam after use in the steam engine 8 is supplied to the steam using equipment as it is via the exhaust steam passage 19, or is boosted by a steam ejector and supplied to the steam using equipment. To do. In this case, it goes without saying that a steam header may be used.

  It is preferable that the feed water heating system 1 further includes a waste heat recovery heat exchanger 22. The waste heat recovery heat exchanger 22 is an indirect heat exchanger for supplying water to the subcooler 17 and heat source water after passing through the evaporator 16. Accordingly, the water in the water supply channel 9 is passed through the waste heat recovery heat exchanger 22, the subcooler 17, and the condenser 14 in order. On the other hand, the heat source water in the heat source water tank 6 is passed through the evaporator 16 via the heat source supply path 21 and then passed to the waste heat recovery heat exchanger 22.

  The heat source water tank 6 stores heat source water as a heat source of the heat pump 4. The heat source water is, for example, waste hot water (hot water discharged from a factory or the like). The heat source water tank 6 is provided with a heat source water supply path 23 and an overflow path 24 that overflows a predetermined amount or more of water.

  The heat source water in the heat source water tank 6 is passed through the evaporator 16 of the heat pump 4 through the heat source supply path 21 and then passed through the waste heat recovery heat exchanger 22. The heat source supply path 21 is provided with a heat source supply pump 25 on the upstream side of the evaporator 16. By operating the heat source supply pump 25, the heat source water from the heat source water tank 6 is discarded with the evaporator 16. The heat recovery heat exchanger 22 can be passed through in order.

  By passing the heat source water through the waste heat recovery heat exchanger 22 after passing the evaporator 16 first, compared with the case where the heat source water is passed through the evaporator 16 after passing the waste heat recovery heat exchanger 22 first. Further, the evaporation temperature (that is, the evaporation pressure) of the refrigerant in the evaporator 16 can be increased, the pressure ratio of the compressor 13 can be reduced, and energy saving can be achieved.

  In the water supply passage 9, a hot water temperature sensor 26 is provided on the outlet side of the condenser 14. The tapping temperature sensor 26 detects the water temperature after passing through the condenser 14. Based on the temperature detected by the hot water temperature sensor 26, the feed water pump 11 is controlled. Here, the feed water pump 11 is inverter-controlled so that the temperature detected by the tapping temperature sensor 26 is maintained at a set temperature (tapping temperature setting value). That is, the flow rate of the water supplied to the water supply tank 3 through the water supply passage 9 is adjusted so that the temperature detected by the hot water temperature sensor 26 is maintained at the set temperature.

  A water level detector 27 is provided in the water supply tank 3. The water level detector 27 is not particularly limited in configuration, and for example, an electrode type water level detector or a capacitance type water level detector can be used.

  The heat source water tank 6 is provided with a water level detector 28 for confirming the presence or absence of the heat source water. The configuration of the water level detector 28 is not particularly limited. In the present embodiment, the water level detector 28 is an electrode type water level detector. In this case, the low water level detection electrode rod 29 is inserted into the heat source water tank 6 to monitor whether the water level of the heat source water is lower than the setting.

  The heat source water tank 6 is provided with a heat source temperature sensor 30 that detects the temperature of the heat source water. However, the heat source temperature sensor 30 may be provided in the heat source supply path 21 from the heat source water tank 6 to the evaporator 16.

  Next, control (operation method) of the feed water heating system 1 of the present embodiment will be described. A series of control described below is automatically performed using a controller (not shown).

  Although it is possible to supply water to the water supply tank 3 via the water supply channel 9 and also to supply water via the replenishment water channel 10, the water supply via the water supply channel 9 is normally controlled so that priority is given. Is preferred. For example, the water supply through the water supply channel 9 is controlled so as to maintain the water level of the water supply tank 3 within the set range. However, if the water level of the water supply tank 3 cannot maintain the set range, the water supply through the supply water channel 10 is controlled. It is preferable to supply water to the water supply tank 3. Such control can be performed by controlling the feed water pump 11 and the makeup water pump 12 based on the detection signal of the water level detector 27 provided in the feed water tank 3.

  During the water supply through the water supply path 9, the heat pump 4 is operated and the heat source supply pump 25 is operated. The heat pump 4 is switched between operation and stop depending on whether or not the compressor 13 is activated. The output of the heat pump 4 is preferably controlled based on the water level of the water supply tank 3.

  As described above, the start and stop of the heat pump 4 and the control of the output are performed by controlling the steam supply to the steam engine 8 by the steam supply valve 20. It is preferable to adjust the opening of the steam supply valve 20 such that the lower the water level in the water supply tank 3 is, the higher the output of the steam engine 8 and hence the heat pump 4 is. At this time, the output of the steam engine 8 may be switched in stages or may be adjusted continuously. For example, the heat pump 4 is controlled at three positions: high load operation (typically full load operation = 100% output), low load operation (for example, 50% output), and stop (0% output).

  During the water supply through the water supply path 9, the water supply pump 11 is inverter-controlled for the rotation speed so as to maintain the temperature detected by the tapping temperature sensor 26 at the set temperature. As a result, it is possible to supply water to the water supply tank 3 through the water supply passage 9 at a larger flow rate as the output of the heat pump 4 is larger.

  When the heat pump 4 is operated and water is supplied from the make-up water tank 5 to the water supply tank 3 through the water supply path 9, the water supplied from the make-up water tank 5 is used as the waste heat recovery heat exchanger 22, the supercooler 17, and the condenser. 14 is gradually heated and supplied to the water supply tank 3 at a set temperature. Compared with the case where water is circulated between the water supply tank 3 and the heat pump 4 (condenser 14), the water supply is heated by a single pass (once through) from the makeup water tank 5 to the water supply tank 3. The temperature difference of the feed water before and after passing through the heat pump 4 can be secured, and the coefficient of performance (COP) of the heat pump 4 can be improved. Moreover, each heat exchanger can also be comprised compactly.

  Further, during operation of the heat pump 4, that is, water supply to the water supply tank 3 via the water supply passage 9, the water temperature of the heat source water tank 6 is monitored by the heat source temperature sensor 30, and the output of the heat pump 4 is adjusted based on the temperature. May be. The higher the temperature of the heat source water as the heat source of the heat pump 4, the lower the output of the heat pump 4. By adjusting the output of the heat pump 4 in consideration of the temperature of the heat source water, the water supply flow rate to the water supply tank 3 through the water supply path 9 can be stabilized regardless of the temperature change of the heat source water.

  Further, when the water level of the heat source water tank 6 falls during the operation of the heat pump 4 and the low water level detection electrode rod 29 does not detect the water level, the operation of the heat pump 4 is stopped, and the heat source supply pump 25 is stopped and the evaporator It is preferable to stop the supply of heat source water to 16. This prevents the heat pump 4 from being wasted. Similarly, during operation of the heat pump 4 (that is, during water supply control to the water supply tank 3 via the water supply channel 9), if the amount of water supplied through the water supply channel 9 falls below the setting, the operation of the heat pump 4 is stopped. While stopping, it is preferable to stop the heat source supply pump 25 to stop the supply of the heat source water to the evaporator 16.

  In the above embodiment, the water pump 11 is connected to the inverter so that the heat pump 4 is operated during the water supply to the water supply tank 3 through the water supply passage 9 and the temperature detected by the tapping temperature sensor 26 is maintained at the set temperature. The feed water flow rate to the feed water tank 3 via the feed water channel 9 was adjusted. At that time, preferably, the steam supply amount to the steam engine 8 is adjusted based on the water level of the water supply tank 3, and the load of the compressor 13 by the steam engine 8 is adjusted. However, instead of such control, the following control may be performed.

  That is, the condenser 14 of the heat pump 4 in a state where the water supply flow rate to the water supply tank 3 through the water supply channel 9 and the water supply flow rate to the water supply tank 3 through the water supply channel 9 by the water supply pump 11 are kept at a predetermined constant flow rate. The steam supply amount to the steam engine 8 may be adjusted based on the water temperature on the outlet side or the refrigerant pressure or refrigerant temperature on the outlet side of the compressor 13. Specifically, the steam supply valve 20 is controlled or the detection temperature of the pressure sensor 31 or the temperature sensor provided on the outlet side of the compressor 13 is set so that the detection temperature of the tapping temperature sensor 26 is maintained at the set temperature. What is necessary is just to control the steam supply valve 20 so that it may maintain at temperature. Control based on the water temperature on the outlet side of the condenser 14 is control for directly obtaining hot water having a desired temperature. Further, the control based on the refrigerant pressure or the refrigerant temperature on the outlet side of the compressor 13 is a control for maintaining a desired saturation temperature of the refrigerant in the condenser 14 and indirectly obtaining hot water at a desired temperature.

  The feed water warming system 1 of the present invention is not limited to the configuration of the above embodiment, and can be changed as appropriate. For example, in the above-described embodiment, the feed water pump 11 is inverter-controlled in order to adjust the feed water flow rate to the feed water tank 3 through the feed water channel 9, but the feed water pump 11 is provided on the feed water channel 9 while being on / off controlled. The opening degree of the valve may be adjusted. That is, if the flow rate of the water supply through the water supply channel 9 can be adjusted based on the temperature detected by the hot water temperature sensor 26, the flow rate adjustment method can be changed as appropriate.

  Further, the heat pump 4 is not limited to a single stage, and may be a plurality of stages. When the heat pump 4 has a plurality of stages, adjacent stage heat pumps may be connected using an indirect heat exchanger, or may be connected using a direct heat exchanger (intercooler). In the latter case, an intermediate cooler that receives the refrigerant from the compressor of the lower heat pump and the refrigerant from the expansion valve of the upper heat pump and directly exchanges heat between the two refrigerants is provided. And the evaporator of the upper heat pump. As described above, the multi-stage (multi-stage) heat pump includes a single-stage multi-stage heat pump, a multi-element (multi-element) heat pump, or a combination thereof.

  In addition, if water can be supplied to the water supply tank 3 through the water supply channel 9 via the condenser 14 and water can be supplied through the replenishment water channel 10 without going through the condenser 14, the specifics of the water supply channel 9 and the water supply channel 10 can be specified. The configuration is not limited to the configuration of the above embodiment and can be changed as appropriate. For example, in the above embodiment, the water supply channel 9 and the replenishment water channel 10 are provided in parallel so as to connect the replenishment water tank 5 and the water supply tank 3, respectively, but one end of the water supply channel 9 and the replenishment water channel 10 ( One or both of the end portion on the make-up water tank 5 side and the other end portion (the end portion on the water supply tank 3 side) may be a common conduit. In other words, one end portion of the replenishment water channel 10 may be provided so as to branch from the water supply channel 9 instead of being connected to the replenishment water tank 5, and the other end portion of the replenishment water channel 10 is connected to the water supply tank 3. Instead, it may be provided so as to merge with the water supply channel 9 before the water supply tank 3. When one end of the replenishment water channel 10 is provided so as to branch from the water supply channel 9 instead of being connected to the replenishment water tank 5, the water supply pump 11 is provided in the water supply channel 9 downstream from the branching unit, while the replenishment water channel 10 may be provided with a make-up water pump 12, but a pump is provided only in the common pipe upstream of the branch portion, and the valves provided in the water supply passage 9 and / or the make-up water passage 10 downstream of the branch portion are opened. By adjusting the degree, the flow rate through the water supply channel 9 and the replenishment channel 10 may be adjusted.

  Moreover, in the said Example, although the supplementary water tank 5 was installed in order to store the water supply to the water supply tank 3, installation of the supplementary water tank 5 may be abbreviate | omitted by the case, and the water supply path 9 and the supplement may be directly from a water supply source. Water may be passed through the water channel 10.

  Moreover, in the said Example, although the water supply from the supplementary water tank 5 to the water supply tank 3 was enabled via the water supply path 9 and / or the supplementary water path 10, these water supplies may be directly performed from a water softener. For example, in FIG. 1, the base end portions of the water supply channel 9 and the makeup water channel 10 are collectively connected to the water softener, and instead of omitting the installation of the water supply pump 11, an electric valve (motor valve) provided in the water supply channel 9 is opened. Instead of adjusting the degree and omitting the installation of the makeup water pump 12, the opening and closing of the electromagnetic valve provided in the makeup water channel 10 may be controlled.

  Moreover, although the said Example demonstrated the system which can heat the water supply to the feed water tank 3 of the boiler 2 with the heat pump 4, the utilization place of the stored water of the feed water tank 3 is not restricted to the boiler 2, and can be changed suitably. is there. In some cases, the replenishment water tank 5 and the replenishment water channel 10 may be omitted.

  Furthermore, although the said Example demonstrated the example which used heat-source water as a heat source of the heat pump 4, as a heat-source fluid of the heat pump 4, not only heat-source water but various fluids, such as air and waste gas, can be used. However, while the heat source fluid gives heat (sensible heat) to the refrigerant of the heat pump 4 in the evaporator 16, the heat source fluid itself falls in temperature, and then gives heat (sensible heat) to the feed water in the waste heat recovery heat exchanger 22. The fluid itself with a temperature drop is preferable.

DESCRIPTION OF SYMBOLS 1 Supply water heating system 2 Boiler 3 Supply water tank 4 Heat pump 5 Supply water tank 6 Heat source water tank 8 Steam engine 9 Supply channel 10 Supply water channel 11 Supply water pump 12 Supply water pump 13 Compressor 14 Condenser 15 Expansion valve 16 Evaporator 17 Overflow Cooler 18 Steam supply path 19 Waste steam path 20 Steam supply valve 21 Heat source supply path 22 Waste heat recovery heat exchanger 26 Hot water temperature sensor 27 Water level detector 31 Pressure sensor (or temperature sensor)

Claims (5)

A compressor, a condenser, an expansion valve, and an evaporator are sequentially connected in an annular manner to circulate the refrigerant, draw up heat from a heat source fluid that passes through the evaporator, and heat water that passes through the condenser When,
A water supply tank through which a waste heat recovery heat exchanger, a supercooler and the condenser are passed in order and can be supplied by a water supply channel;
A boiler that heats the feed water from this feed tank to steam,
A steam engine that generates power using steam from this boiler,
The waste heat recovery heat exchanger is an indirect heat exchanger between the water supply to the water supply tank via the water supply channel and the heat source fluid after passing through the evaporator,
The supercooler is an indirect heat exchanger between water supplied to the water supply tank via the water supply channel and refrigerant from the condenser to the expansion valve,
The compressor is driven by the steam engine. The feed water heating system according to claim 1, wherein the steam after use in the steam engine is used in any one of the following (a) to (c).
(A) Steam after use in the steam engine is injected into the water supply channel or the water supply tank, or indirectly exchanges heat with water in the water supply channel or the water supply tank, so that the water supply channel or the water supply water is supplied. Warm the water in the tank.
(B) The steam after use in the steam engine is injected into the heat source fluid or indirectly heat-exchanged with the heat source fluid on the upstream side of the evaporator to heat the heat source fluid.
(C) The steam after use in the steam engine is supplied to the steam using facility as it is or after being pressurized. Adjusting the amount of water flow to the condenser so that the water temperature at the outlet side of the condenser of the heat pump is maintained at a set temperature while operating the heat pump during water supply to the water supply tank via the water supply channel. The feed water warming system according to claim 1 or 2, wherein The feed water heating system according to any one of claims 1 to 3, wherein steam supply to the steam engine is controlled based on a water level of the feed water tank. The steam engine is based on the water temperature on the condenser outlet side of the heat pump or the refrigerant pressure or refrigerant temperature on the compressor outlet side while maintaining a predetermined water supply flow rate while supplying water to the water supply tank via the water supply channel. The feed water warming system according to claim 1, wherein steaming to the water is controlled.

Images