JP2014194316A - Water supply and heating system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To effectively use a relatively high-temperature heat source fluid if fluids at different temperatures are present as the heat sources of a heat pump.SOLUTION: A heat pump 13 pumps up heat from a heat source fluid passing through an evaporator 17 and heats water flowing to a condenser 15 from a water supply path 9. As tanks for storing the heat source fluid for the evaporator 17, a water supply and heating system includes a first tank 6 and a second tank 7. A relatively low-temperature heat source fluid is stored in the first tank 6, and a relatively high-temperature heat source fluid is stored in the second tank 7. The heat source fluid to be supplied to the evaporator 17 can be switched between that in the first tank 6 and that in the second tank 7.

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)

  In a feed water heating system using a heat pump, for example, waste warm water discharged from a factory or the like can be used as a heat source of the heat pump. However, the waste hot water ranges from a high temperature close to 100 ° C. like a steam drain in a steam using facility to a low temperature of about 40 ° C. in a cooling tower or the like.

  Basically, the higher the heat source temperature (waste water temperature), the higher the efficiency of the heat pump. However, regardless of the temperature of the waste warm water, all waste warm water is collected in one tank and used. The temperature is averaged, and even if hot waste water exists, it cannot be used effectively. This is especially true when a waste heat recovery heat exchanger is provided, as in the above-mentioned invention.

  Therefore, the problem to be solved by the present invention is to provide a feed water heating system capable of effectively utilizing a high-temperature heat source fluid.

  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. A heat pump that draws heat from the heat source fluid passed through the evaporator and heats the water in the water supply passage that is passed through the condenser; a first tank that stores the heat source fluid to the evaporator; and A second tank for storing a heat source fluid having a temperature higher than that of the heat source fluid, and the heat source fluid supplied to the evaporator can be switched between the heat source fluid in the first tank and the heat source fluid in the second tank. This is a water supply heating system characterized by that.

  According to the first aspect of the present invention, the first tank and the second tank are provided as the heat source fluid storage tank, the relatively low temperature heat source fluid is stored in the first tank, and the second tank is relatively A hot heat source fluid is stored. Since the heat source fluid supplied to the evaporator can be switched between the heat source fluid of the first tank and the heat source fluid of the second tank, when there is a relatively high temperature heat source fluid, the heat source fluid of the heat pump is used. Can be used as In this way, a high-temperature heat source fluid can be effectively utilized, thereby improving system efficiency.

  According to a second aspect of the present invention, the supercooler for exchanging heat between the water supplied to the condenser and the refrigerant from the condenser, the heat source fluid from the evaporator and the water supplied to the subcooler are heated. A waste heat recovery heat exchanger to be replaced, while supplying the heat source fluid from the second tank to the evaporator, depending on whether the heat source fluid from the waste heat recovery heat exchanger is equal to or higher than the return temperature, It is a feed water heating system of Claim 1 which switches whether a heat source fluid is supplied to a said 1st tank.

  According to the second aspect of the present invention, the water supplied through the water supply channel is passed through the waste heat recovery heat exchanger, the subcooler and the condenser in turn, while the heat source fluid of the heat pump is the evaporator and the waste heat. The recovered heat exchanger is passed through in order. 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. If the heat source fluid from the second tank is being supplied to the evaporator and the heat source fluid from the waste heat recovery heat exchanger is above the return temperature, the heat source fluid is supplied to the first tank and the other heat pump It can be used as a heat source.

  The invention according to claim 3 includes a plurality of heat pump units including the heat pump and the waste heat recovery heat exchanger, and at least one of the plurality of heat pump units includes the second tank. The heat source fluid according to claim 2, wherein the heat source fluid can be supplied while the remaining heat pump unit can be supplied with the heat source fluid from the first tank.

  According to the third aspect of the present invention, the heat source fluid from the second tank can be supplied to at least one heat pump unit among the plurality of heat pump units, and the heat source fluid after use is at a return temperature or higher. If so, the heat source fluid can be supplied to the first tank and used in other heat pump units.

  Furthermore, in the invention according to claim 4, the first tank and the second tank are a common tank, and a plurality of heat source fluids having different temperatures are passed as supply paths for the heat source fluid to the common tank. A supply path is provided, and in the supply path through which the heat source fluid having a higher temperature among the plurality of supply paths is passed, the heat source fluid is passed to the evaporator before the heat source fluid is put into the common tank. The supply water heating system according to any one of claims 1 to 3, wherein a branch path is provided.

  According to the fourth aspect of the present invention, the same effect as that of the first aspect of the present invention can be realized without dividing the first tank and the second tank.

  ADVANTAGE OF THE INVENTION According to this invention, the feed water heating system which can utilize a high temperature heat source fluid effectively is realizable.

It is the schematic which shows Example 1 of the feed water heating system of this invention. It is the schematic which shows Example 2 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 diagram showing a first 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 warms feed water to the feed water tank 3 of the boiler 2, and stores the feed water tank 3 that stores the feed water to the boiler 2 and the feed water to the feed water tank 3. A replenishing water tank 4 to be stored, one or a plurality of heat pump units 5 for heating water supplied from the replenishing water tank 4 to the water supply tank 3, and heat source water (for example, waste hot water) as a heat source of the heat pump unit 5 are stored. A first tank 6 and a second tank 7 are provided.

  Although the number of heat pump units 5 is not particularly limited, two units are installed here. Moreover, the structure of each heat pump unit 5 is mutually the same in a present Example. However, depending on the case, the heat pump units 5 may have different rated outputs, for example.

  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 8 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 use facilities (not shown), but drain (condensed water of steam) from the steam use facility may be returned to the water supply tank 3. In the illustrated example, only one boiler 2 is shown, but a plurality of boilers may be provided.

  The water supply tank 3 can supply water from the make-up water tank 4 via the heat pump unit 5 through the water supply passage 9 and can be supplied through the make-up water passage 10 without going through the heat pump unit 5. Each heat pump unit 5 is provided such that water supplied from the makeup water tank 4 to the water supply tank 3 is passed in parallel. In the case of the illustrated example, the water supply path 9 from the makeup water tank 4 is bifurcated and connected to each heat pump unit 5, and the pipe lines from each heat pump unit 5 are joined and connected to the water supply tank 3.

  By controlling the feed water pump 11 provided in each heat pump unit 5 and the make-up water pump 12 provided in the make-up water channel 10, water supply to the water supply tank 3 by the water supply channel 9 via each heat pump unit 5, and the heat pump unit It is possible to control the supply of water to the water supply tank 3 through the replenishment water channel 10 that does not go through 5.

  Each heat pump unit 5 includes a heat pump 13 and a water supply pump 11. The water supply pump 11 can change the water supply flow rate in this embodiment in addition to the presence or absence of water supply to the water supply tank 3 via the heat pump unit 5 in which it is installed. Specifically, the rotation speed of the feed water pump 11 of the present embodiment can be changed by an inverter, and the feed water flow rate to the feed water tank 3 via the heat pump unit 5 is adjusted by changing the rotation speed. Can do. On the other hand, the makeup water pump 12 is on / off controlled in this embodiment.

  The makeup water tank 4 stores the water supply to the water supply tank 3. In this embodiment, soft water is used as water supply to the makeup water tank 4. 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 4 and stored. By controlling the water supply from the water softener based on the water level of the makeup water tank 4, the water level of the makeup water tank 4 is maintained as desired.

  Each heat pump 13 is a vapor compression heat pump, and includes a compressor 14, a condenser 15, an expansion valve 16, and an evaporator 17 that are sequentially connected in an annular shape. The compressor 14 compresses the gas refrigerant to a high temperature and a high pressure. The condenser 15 condenses and liquefies the gas refrigerant from the compressor 14. Further, the expansion valve 16 allows the liquid refrigerant from the condenser 15 to pass through, thereby reducing the pressure and temperature of the refrigerant. The evaporator 17 evaporates the refrigerant from the expansion valve 16.

  Accordingly, in each of the heat pumps 13, in the evaporator 17, the refrigerant takes heat from the outside and vaporizes, while in the condenser 15, the refrigerant dissipates heat to the outside and condenses. Using this, in this embodiment, each heat pump 13 draws heat from the heat source water in the evaporator 17, and heats the water in the water supply passage 9 in the condenser 15.

  Each heat pump 13 preferably further includes a supercooler 18 between the condenser 15 and the expansion valve 16. The supercooler 18 is an indirect heat exchanger between the refrigerant from the condenser 15 to the expansion valve 16 and the feed water to the condenser 15. The subcooler 18 can supercool the refrigerant from the condenser 15 to the expansion valve 16 by supplying water to the condenser 15, and can supply the refrigerant to the condenser 15 by the refrigerant from the condenser 15 to the expansion valve 16. The water supply can be heated. The refrigerant of each heat pump 13 preferably releases latent heat in the condenser 15 and releases sensible heat in the subcooler 18.

  That is, in the condenser 15, the gas refrigerant is condensed into a liquid refrigerant, and the liquid refrigerant is supplied to the subcooler 18, and the liquid refrigerant is further cooled (supercooled) in the subcooler 18. 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 each heat pump 13, an accumulator is installed on the inlet side of the compressor 14, an oil separator is installed on the outlet side of the compressor 14, or the outlet side of the condenser 15 (the condenser 15 and the subcooler). 18), a liquid receiver may be installed.

  By the way, each heat pump 13 is good to be able to change the output. In the present embodiment, the output of the heat pump 13 can be changed by changing the power supply frequency of the motor of the compressor 14 and thus the rotational speed by an inverter. For example, the heat pump 13 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).

  Each heat pump unit 5 preferably further includes a waste heat recovery heat exchanger 19. The waste heat recovery heat exchanger 19 is an indirect heat exchanger for supplying water to the subcooler 18 and heat source water after passing through the evaporator 17. Therefore, the water in the water supply channel 9 is passed through the waste heat recovery heat exchanger 19, the supercooler 18, and the condenser 15 in order. On the other hand, the heat source water in the first tank 6 or the second tank 7 is passed through the evaporator 17 via the heat source supply path 20 and then passed to the waste heat recovery heat exchanger 19. At this time, in this embodiment, heat source water is supplied in parallel to each heat pump unit 5, and in each heat pump unit 5, the heat source water is passed through the evaporator 17 and the waste heat recovery heat exchanger 19 in order.

  The first tank 6 and the second tank 7 store heat source water as a heat source of the heat pump 13. The heat source water is, for example, waste hot water (hot water discharged from a factory or the like). The waste hot water can have a variety of temperatures from a high temperature close to 100 ° C. like steam drain in a steam using facility to a low temperature of about 40 ° C. in a cooling tower or the like. Therefore, if various heat source waters are collected in one tank without considering the temperature, the relatively high temperature heat source water cannot be effectively used. Therefore, in this embodiment, the heat source water is stored separately in a plurality of tanks 6 and 7 in accordance with the temperature and used separately. Specifically, a relatively low temperature heat source water having a temperature lower than a predetermined temperature is stored in the first tank 6, and a relatively high temperature heat source water having a temperature equal to or higher than the predetermined temperature is stored in the second tank 7. Can be used as a heat source of the heat pump 13 at a high temperature.

  The first tank 6 is provided with a relatively low-temperature heat source water supply path 21 and an overflow path 22 that overflows a predetermined amount or more of water. On the other hand, the second tank 7 is provided with a supply path 23 for relatively high-temperature heat source water and an overflow path 24 for overflowing a predetermined amount or more of water. The heat source water overflowing from the second tank 7 via the overflow path 24 may be supplied to the first tank 6.

  The heat source water in the first tank 6 can be supplied in parallel to the heat pump units 5 via the heat source supply path 20. In the illustrated example, the heat source supply path 20 from the first tank 6 is branched and connected to each heat pump unit 5. The heat source supply path 20B from the second tank 7 is connected to the heat source supply path 20A to the right heat pump unit 5 in FIG. And the water supply three-way valve 25 is provided in the connection part. The water supply three-way valve 25 switches between supplying heat source water in the first tank 6 or supplying heat source water in the second tank 7 as heat source water to the right heat pump unit 5.

  The flow of the heat source water to each heat pump unit 5 is controlled by a heat source supply pump 26 provided in each heat pump unit 5. That is, in FIG. 1, if the right heat source supply pump 26 is operated, the heat source water can be passed through the right heat pump unit 5, and if the left heat source supply pump 26 is operated, the left heat pump unit 5 is supplied to the left heat pump unit 5. Heat source water can be passed. In each heat pump unit 5, the heat source water passes through the evaporator 17, passes through the waste heat recovery heat exchanger 19, and is discharged through the heat source discharge path 27.

  In FIG. 1, the heat source discharge path 27 from the right heat pump unit 5 is provided with a heat source return path 28 branched to the first tank 6. A drainage three-way valve 29 is provided at the branch portion. The drainage three-way valve 29 switches whether the heat source water after use in the right heat pump unit 5 is drained as it is or supplied to the first tank 6. The right heat pump unit 5 can be supplied with relatively high-temperature heat source water stored in the second tank 7. In that case, the heat pump unit 5 supplies the heat source water after use to the first tank 6 as desired. It can be reused in another or the same heat pump unit 5.

Here, the temperature sensor 30 provided in the heat source discharge path 27 from the right heat pump unit 5 monitors the temperature T _H ′ of the heat source water after use in the heat pump unit 5, and the temperature is stored in the first tank 6. If the temperature T _T of the stored water by the provided temperature sensor 31 is higher (T _H ′> T _T ), the heat source water after use is supplied to the first tank 6 by the right heat pump unit 5, and if not, the waste water is discharged. The drainage three-way valve 29 is switched so that it does.

By the way, in the present Example, the hot water temperature sensor 32 is provided in the water supply path 9 in the exit side of each heat pump unit 5 (namely, exit side of each condenser 15). Hot water temperature sensor 32 detects a water temperature T _W having passed through the condenser 15. Each heat pump unit 5, based on the detected temperature T _W of the hot water temperature sensor 32, it is preferable the water supply pump 11 is controlled. Here, the water supply pump 11 is an inverter controlled to maintain the detected temperature T _W of the hot water temperature sensor 32 to a set temperature (e.g. 75 ° C.). That is, the water supply to the water supply tank 3 through the water supply path 9 so as to maintain the set temperature detection temperature T _W of the hot water temperature sensor 32, the flow rate is adjusted.

  The water supply tank 3 is provided with a water level detector (not shown). The configuration of the water level detector is not particularly limited. In this embodiment, the water level detector is an analog water level detector that can obtain an output corresponding to the water level. That is, the water level detector continuously detects the water level in the water supply tank 3. Specifically, a water pressure type water level detector using the fact that the water pressure changes according to the water level in the water supply tank 3 can be used, but a pressure sensor can be used instead. Alternatively, a capacitive water level detector can be used. However, the water level detector is not limited to such an analog type, and an electrode type water level detector may be used depending on circumstances.

  The first tank 6 and the second tank 7 are each provided with a water level detector (not shown) in order to confirm the presence or absence of heat source water. The configuration of the water level detector is not particularly limited. In this embodiment, the water level detector is an electrode-type water level detector, and monitors whether the water level of the heat source water is lower than the setting.

  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).

  The water supply tank 3 can be supplied with water by the water supply path 9 via the heat pump unit 5 and can be supplied by the replenishment water path 10 without passing through the heat pump unit 5. It is preferable to control the priority. For example, the water supply via the water supply channel 9 is controlled as described later so as to maintain the water level of the water supply tank 3 within a set range. If the water level of the water supply tank 3 falls below a predetermined level, the water supply via the supply water channel 10 is controlled. It is preferable to supply water to the water supply tank 3.

  In the feed water warming system 1 of the present embodiment, the number and / or output of the heat pumps 13 are changed according to the use load of the stored water in the feed water tank 3. The usage load of the stored water in the water supply tank 3 is monitored by a water level detector provided in the water supply tank 3. When the water level in the water supply tank 3 falls below the lower limit water level, water supply to the water supply tank 3 via the water supply channel 9 is started, and the number of operating heat pumps 13 and / or the output is increased as the water level decreases to the water supply tank. Increase the amount of tapping. On the contrary, when the water level of the water supply tank is recovered, the number of operating heat pumps 13 and / or the output is decreased as the water level is increased, and the amount of hot water discharged to the water supply tank 3 is decreased. 13 is stopped and the water supply to the water supply tank 3 through the water supply path 9 is stopped.

In each heat pump unit 5, the water supply pump 11 and the heat source supply pump 26 are operated while the heat pump 13 is in operation. At this time, the water supply pump 11, so as to maintain the detected temperature T _W of the hot water temperature sensor 32 to a set temperature, the rotational speed is inverter controlled. As a result, when the heat pump 13 is in a high load operation, water can be supplied to the water supply tank 3 through the water supply passage 9 at a higher flow rate than in a low load operation.

  In the feed water warming system 1 of the present embodiment, in FIG. 1, heat pump units 5 are provided on the left and right, but the heat pump unit 5 on the right side has a relatively low temperature heat source water in the first tank 6 as heat source water, The relatively high temperature heat source water in the second tank 7 can be switched by the water supply three-way valve 25 and supplied. And it is preferable to give priority to the operation of the heat pump unit 5 on the right side as much as possible, and to use relatively high-temperature heat source water in the second tank 7 as the heat source water.

  For example, a heat pump unit capable of supplying stored water in the second tank 7 in a state where some of the heat pump units 5 are operated in relation to the water level of the water supply tank 3 among the plurality of heat pump units 5 (in FIG. 1). It is preferable that the right heat pump unit) 5 is operated so as to use heat source water as hot as possible. System efficiency can be improved by using relatively high-temperature heat source water. The first tank 6 and the second tank 7 are each monitored for the presence or absence of heat source water by a water level detector. For example, if there is no heat source water in the second tank 7, the heat source water from the first tank 6 is supplied, If both heat source waters are lost, the operation of the heat pump 13 should be stopped.

  Further, the output of the heat pump 13 (the number of rotations of the compressor 14) may be adjusted based on the temperature of the heat source water being supplied to the heat pump 13. The higher the temperature of the heat source water, the lower the output of the heat pump 13 can be.

In FIG. 1, while the relatively high temperature heat source water in the second tank 7 is being supplied to the right heat pump unit 5, the heat source water temperature T _H ′ on the outlet side of the heat pump unit 5 is monitored, and the temperature is returned to a predetermined level. If the temperature (water temperature T _T of the stored water in the first tank 6 in this embodiment) is higher (T _H ′> T _T ), the heat source water after use is returned to the first tank 6 by the right heat pump unit 5, If not, it is preferable to drain as it is.

  When the heat pump 13 is operated to supply water from the make-up water tank 4 to the water supply tank 3 through the water supply passage 9, the water supplied from the make-up water tank 4 is used as the waste heat recovery heat exchanger 19, the supercooler 18, and the condenser. 15 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 13 (condenser 15), the water supply is heated in one pass (once through) from the makeup water tank 4 to the water supply tank 3. The temperature difference of the feed water before and after passing through the heat pump 13 can be secured, and the coefficient of performance (COP) of the heat pump 13 can be improved. Moreover, each heat exchanger can also be comprised compactly.

  FIG. 2 is a schematic diagram showing Example 2 of the feed water heating system 1 of the present invention. The feed water heating system 1 of the second embodiment is basically the same as that of the first embodiment. Therefore, in the following description, differences between the two will be mainly described, and corresponding portions will be described with the same reference numerals.

  In the first embodiment, the first tank 6 and the second tank 7 are provided as the heat source water storage tank. However, in the second embodiment, the heat source water storage tank is configured by one common tank 33. The common tank 33 is provided with a heat source water supply path 21 having a relatively low temperature (below a predetermined temperature) and a heat source water supply path 23 having a relatively high temperature (a predetermined temperature or higher). A branch path 34 is provided in front of the common tank 33 in the relatively high-temperature heat source water supply path 23. The branch path 34 is connected to the heat source supply path 20A from the common tank 33 to the right heat pump unit 5, and a water supply three-way valve 25 is provided at the connection portion. That is, the branch path 34 corresponds to the heat source supply path 20B from the second tank 7 in the first embodiment. In addition, a switching three-way valve 35 is provided at the base end portion of the branch path 34, and heat source water is supplied to the common tank 33 by the switching three-way valve 35 or to the heat pump unit 5 via the branch path 34. The supply can be switched.

In the case of the present embodiment, the switching three-way valve 35 and the water supply three-way valve 25 supply relatively high-temperature heat source water to the right heat pump 13 without going through the common tank 33, or each heat pump 13 through the common tank 33. Can be switched to. For example, to monitor the temperature _T L, _{T H} of heat source water, respectively to the supply path 21, 23 of the heat source water is provided to the temperature sensor 36 and 37, a relatively temperature _{T H} of the hot heat source water is relatively cold heat source water When the temperature is higher than the temperature T _L (T _H > T _L ) or higher than the predetermined temperature (T _H > T _L + ΔT), it is preferable to pass the heat pump unit 5 directly without passing through the common tank 33. In this case, if the temperature T _H ′ after use in the heat pump unit 5 is higher than a predetermined return temperature (water temperature T _T of the water stored in the common tank 33 in this embodiment) (T _H ′> T _T ). The used heat source water is preferably supplied to the common tank 33 via the heat source return path 28 and used as a heat source for the other or the same heat pump unit 5. Other configurations are the same as those of the first embodiment, and thus the description thereof is omitted.

  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 said Example, the heat pump unit 5 may be not only two but three or more, and may be only one. Moreover, in the said Example, although the comparatively high temperature heat source water was able to be supplied to only one among several heat pump units 5, comparatively high temperature heat source water is supplied to two or more or all the heat pump units 5. It may be possible. Then, on the outlet side of the heat pump unit 5 to which relatively high-temperature heat source water can be supplied, the first tank 6 (first embodiment) and the common tank 33 (second embodiment) are supplied to the heat source water via the heat source return path 28 as desired. It is preferable to be able to supply to

  Moreover, in the said Example, in order to adjust the water supply flow volume to the water supply tank 3 via the water supply path 9, in each heat pump unit 5, although the water supply pump 11 was inverter-controlled, while controlling the water supply pump 11 on-off, You may adjust the opening degree of the valve | bulb provided in the water supply path 9. FIG. 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 tapping temperature sensor 32, the flow rate adjustment method can be changed as appropriate.

  Further, in each heat pump unit 5, the heat pump 13 is not limited to a single stage, and may be a plurality of stages. When the heat pump 13 has a plurality of stages, the heat pumps in adjacent stages 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 path 9 via the heat pump unit 5 and water can be supplied through the replenishment water path 10 without going through the heat pump unit 5, the specifics of the water supply path 9 and the water supply path 10 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 4 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 makeup water tank 4 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 of the replenishment water channel 10 is not connected to the replenishment water tank 4 but may be provided so as to branch from the water supply channel 9, and the other end 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 replenishing water channel 10 is provided not to be connected to the replenishing water tank 4 but to be branched from the water supply channel 9, the water supply pump 11 is provided in the water supply channel 9 downstream from the branching unit, while the replenishing water channel is provided. 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 makeup water tank 4 was installed in order to store the water supply to the water supply tank 3, installation of the makeup water tank 4 may be abbreviate | omitted depending on the case, and the water supply channel 9 and the replenishment may be performed directly from the 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 4 to the water supply tank 3 was enabled via the water supply channel 9 and / or the supplementary water channel 10, these water supply may be performed directly 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.

  Furthermore, although the said Example demonstrated the system which can heat the water supply to the water supply tank 3 of the boiler 2 with the heat pump 13, the utilization place of the stored water of the water supply tank 3 is not restricted to the boiler 2, and can be changed suitably. is there. In some cases, the water supply tank 3 may be omitted, or the makeup water tank 4 and the makeup water channel 10 may be omitted.

DESCRIPTION OF SYMBOLS 1 Feed water heating system 2 Boiler 3 Feed water tank 4 Supply water tank 5 Heat pump unit 6 1st tank 7 2nd tank 9 Water supply path 11 Feed water pump 13 Heat pump 14 Compressor 15 Condenser 16 Expansion valve 17 Evaporator 18 Supercooler 19 Waste heat recovery heat exchanger 20 Heat source supply path 21 Relatively low temperature heat source water supply path 23 Relatively high temperature heat source water supply path 25 Water supply three-way valve 26 Heat source supply pump 27 Heat source discharge path 28 Heat source return path 29 Drain three-way valve 33 Common tank 34 Branch 35 Switching three-way valve

Claims (4)

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 the heat source fluid that passes through the evaporator, and add water in the water supply passage that passes through the condenser. A heat pump to heat,
A first tank for storing a heat source fluid to the evaporator;
A second tank for storing a heat source fluid having a temperature higher than that of the heat source fluid of the first tank,
The feed water heating system, wherein the heat source fluid supplied to the evaporator can be switched between the heat source fluid in the first tank and the heat source fluid in the second tank. A subcooler for exchanging heat between the water supplied to the condenser and the refrigerant from the condenser;
A waste heat recovery heat exchanger that exchanges heat between the heat source fluid from the evaporator and the feed water to the subcooler;
Whether or not to supply the heat source fluid to the first tank depending on whether or not the heat source fluid from the waste heat recovery heat exchanger is higher than a return temperature while supplying the heat source fluid from the second tank to the evaporator The feed water heating system according to claim 1, wherein: A plurality of heat pump units including the heat pump and the waste heat recovery heat exchanger are provided,
The heat source fluid from the second tank can be supplied to at least one of the plurality of heat pump units, while the heat source fluid from the first tank can be supplied to the remaining heat pump units. The feed water heating system according to claim 2, wherein: The first tank and the second tank are a common tank,
As the supply path of the heat source fluid to the common tank, there are provided a plurality of supply paths through which the heat source fluids having different temperatures pass.
The supply path through which the heat source fluid having a higher temperature among the plurality of supply paths is passed is provided with a branch path for passing the heat source fluid to the evaporator before the heat source fluid is put into the common tank. The feed water warming system according to any one of claims 1 to 3, wherein:

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