JP2013234791A - Feed water warming system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a feed water warming system using a heat pump, in which the heat pump is efficiently operated.SOLUTION: To a feed water tank 3 of a boiler 2, water can be fed through a water feed path 8 via a condenser 14 of a heat pump 4 and, at the same time, water can be fed through a water replenishment path 9 not through the condenser 14. On the basis of the operation state of the boiler 2 or a water feed state from the feed water tank 3 to the boiler 2, water feed to the feed water tank 3 via the water feed path 8 and an output of the heat pump 4 are controlled. The flowing volume of water to the condenser 14 is preferably adjusted such that an output side water temperature of the condenser 14 of the heat pump 4 is maintained at the set temperature during the water feed to the feed water tank 3 via the water feed path 8.

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 this system, the water supply tank (23) can supply water from a water supply source (21) via a water supply channel, and can also supply water via a heat pump water heater (12) branched from the water supply channel. When the water supply tank (23) falls below the first water level (52L), water supply from the heat pump water heater (12) is started, and when the water supply tank (23) exceeds the second water level (52H) higher than the first water level, the heat pump Water supply from the water heater (12) is stopped. When the water level is lower than the third water level (32L), which is lower than the first water level, water supply from the water supply source (21) is started, and the fourth water level is higher than the third water level but lower than the first water level. If it exceeds (32H), the water supply from a water supply source (21) will be stopped.

JP 2010-25431 A (Claim 4, FIG. 2-3)

  In the invention described in Patent Document 1, depending on the water level in the water supply tank, whether to supply water via a heat pump, to supply water directly, or to stop all water supply can be switched.

  However, when water is supplied via the heat pump, the output of the heat pump is constant, and water supply to the water supply tank cannot be performed quickly and efficiently according to the usage load of the stored water in the water supply tank.

  Therefore, the problem to be solved by the present invention is to quickly and efficiently supply water to the water supply tank according to the use load of the stored water in the water supply tank in the water supply heating system using the heat pump.

  The present invention has been made to solve the above-mentioned problems, and the invention according to claim 1 is capable of supplying water through a water supply path via a heat pump capable of changing output and a condenser of the heat pump, A water supply tank capable of supplying water through a replenishment water channel without passing through the condenser, and a boiler supplied with water from the water supply tank, and based on the operation state of the boiler or the water supply state from the water supply tank to the boiler, It is a feed water heating system characterized by controlling the feed water to the feed water tank through the feed water channel and the output of the heat pump.

  According to the first aspect of the present invention, the water supply to the water supply tank via the water supply channel and the output of the heat pump are controlled based on the operation state of the boiler or the state of water supply to the boiler, and according to the boiler load. Water can be quickly supplied to the water tank.

  According to a second aspect of the present invention, the amount of water flow to the condenser is adjusted so that the water temperature on the outlet side of the condenser of the heat pump is maintained at a set temperature during water supply to the water supply tank via the water supply passage. The feed water warming system according to claim 1, wherein:

  According to the second aspect of the present invention, the amount of water flow to the condenser is adjusted so that the water temperature at the outlet side of the condenser of the heat pump is maintained at the set temperature during the water supply to the water supply tank via the water supply channel. Thus, the water supply temperature via the water supply channel can be maintained as desired.

  According to a third aspect of the present invention, the heat pump is controlled at least at three positions of high load operation, low load operation and stop, and the boiler is controlled at least at three positions of high combustion state, low combustion state and stop. When the boiler is in a high combustion state, the heat pump is operated at a high load, when the boiler is in a low combustion state, the heat pump is operated at a low load, and when the boiler is stopped, the heat pump is stopped. The feed water warming system according to claim 1 or 2.

  According to invention of Claim 3, the amount of water supply corresponding to the evaporation amount of a boiler can be supplied to a water supply tank via a water supply path, heating with a heat pump. Moreover, since the combustion state of the boiler corresponds to the operation state of the heat pump, it can be realized by simple control.

  The invention according to claim 4 is characterized in that the output of the heat pump is controlled based on the operation state of the water supply pump from the water supply tank to the boiler or the water supply flow rate from the water supply tank to the boiler. It is a feed water heating system of Claim 1 or Claim 2.

  According to invention of Claim 4, the amount of water supply corresponding to the evaporation amount of a boiler can be supplied to a water supply tank via a water supply path, heating with a heat pump. Moreover, since the water supply state required by the boiler corresponds to the operating state of the heat pump, it can be realized by simple control.

  The invention according to claim 5 comprises a plurality of the heat pumps and the boilers, and increases or decreases the number of operating heat pumps and the output of each heat pump as the number of operating boilers and the amount of combustion of each boiler increase or decrease. It is a feed water heating system of any one of Claims 1-3 characterized by the above-mentioned.

  According to the invention described in claim 5, even if there are a plurality of heat pumps and boilers, the number of operating heat pumps and the output of each heat pump are increased or decreased as the number of operating boilers and the combustion amount of each boiler increase or decrease. Thus, the amount of water supply corresponding to the amount of evaporation of the boiler can be supplied to the water supply tank via the water supply channel while being heated by the heat pump.

  Further, in the invention described in claim 6, when the water level of the water supply tank falls below a setting, water is supplied to the water supply tank even through the makeup water channel. It is a feed water heating system described in 1.

  According to the sixth aspect of the present invention, if the water level in the water supply tank cannot be maintained as desired by only water supply via the water supply channel, water can be supplied to the water supply tank also through the makeup water channel.

  ADVANTAGE OF THE INVENTION According to this invention, in the feed water heating system using a heat pump, the water supply to a water supply tank can be rapidly and efficiently performed according to the use load of the stored water in a water supply tank.

It is the schematic which shows one Example of the feed water heating system of this invention. It is a figure which shows an example of the control method of the feed water heating system of FIG. It is a figure which shows the modification of the control method of the feed water heating system of FIG.

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 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.

  The boiler 2 is typically controlled in combustion quantity so as to maintain the steam pressure as desired. Here, control is performed at three positions: a high combustion state (100% combustion), a low combustion state (50% combustion), and a stop. This control is performed by a boiler controller (not shown) grasping the use load of the steam based on the pressure of the steam to the steam using facility and adjusting the combustion amount of the burner of the boiler 2.

  The boiler 2 is controlled to supply water to the boiler 2 so as to maintain a desired water level in the can. Specifically, the pump 7 provided in the water supply path from the water supply tank 3 to the boiler 2 is controlled by the boiler controller based on the water level in the can.

  The water supply tank 3 can be supplied with water from the make-up water tank 5 via the heat pump 4 through the water supply path 8 and can be supplied through the make-up water path 9 without going through the heat pump 4. By controlling the operation of the water supply pump 10 provided in the water supply path 8 and the makeup water pump 11 provided in the makeup water path 9, via either one or both of the water supply path 8 and the makeup water path 9, Water can be supplied from the makeup water tank 5 to the water supply tank 3. In the water supply passage 8, a waste heat recovery heat exchanger 12 and a heat pump 4 are sequentially provided downstream from the water supply pump 10.

  In the present embodiment, the feed water pump 10 can control the rotation speed by an inverter. By changing the rotation speed of the water supply pump 10, the amount of water supplied to the water supply tank 3 via the water supply path 8 can be adjusted. On the other hand, the makeup water pump 11 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. In this embodiment, the heat pump 4 draws heat from the heat source water as a heat source in the evaporator 16 and heats the water in the water supply channel 8 in the condenser 14.

  The heat pump 4 may be provided with a supercooler 17 between the condenser 14 and the expansion valve 15 as desired. 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 releases latent heat in the condenser 14 and releases sensible heat in the subcooler 17.

  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).

  By the way, the heat pump 4 can change the output (the capacity | capacitance of the compressor 13) in steps. In the present embodiment, the heat pump 4 can be switched between a low load operation and a high load operation with a higher output by changing the rotation speed of the motor of the compressor 13 with an inverter. For example, full load operation (100% output) is performed in a high load operation, and low load operation (for example, 50% output) is performed in a low load operation rather than a high load operation.

  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 18 and an overflow path 19 for overflowing a predetermined amount or more of water.

  The water in the heat source water tank 6 passes through the evaporator 16 of the heat pump 4 through the heat source supply path 20 and then passes through the waste heat recovery heat exchanger 12. The heat source supply path 20 is provided with a heat source supply pump 21 on the upstream side of the evaporator 16. By operating the heat source supply pump 21, the heat source water from the heat source water tank 6 is discarded with the evaporator 16. The heat recovery heat exchanger 12 can be passed through in order.

  The waste heat recovery heat exchanger 12 is an indirect heat exchanger for supplying water from the makeup water tank 5 to the supercooler 17 and heat source water from the evaporator 16. In the case of the present embodiment, the water supply from the makeup water tank 5 to the water supply tank 3 through the water supply channel 8 is sequentially passed from the makeup water tank 5 through the waste heat recovery heat exchanger 12, the supercooler 17 and the condenser 14. Then, the water is supplied to the water supply tank 3.

  In the water supply path 8, a water temperature sensor 22 is provided on the outlet side of the condenser 14. The water temperature sensor 22 detects the water temperature after passing through the condenser 14. Based on the temperature detected by the water temperature sensor 22, the water supply pump 10 is controlled. Here, the feed water pump 10 is inverter-controlled so as to maintain the temperature detected by the water temperature sensor 22 at a set temperature T1 (for example, 75 ° C.). That is, the flow rate of water supplied to the water supply tank 3 through the water supply path 8 is adjusted so that the temperature detected by the water temperature sensor 22 is maintained at the set temperature T1. However, in some cases, such flow rate adjustment control by the water temperature sensor 22 can be omitted.

  The water supply tank 3 is provided with a water level detector 23 that detects that the water level has dropped below a set level. The configuration of the water level detector 23 is not particularly limited. In the present embodiment, an electrode type water level detector is used. That is, the low water level detection electrode rod 24 is inserted into the water supply tank 3, and it is monitored whether the water level in the water supply tank 3 is lower than the setting.

  The heat source water tank 6 is provided with a water level detector 25 that detects that the water level has dropped below a set level. The configuration of the water level detector 25 is not particularly limited, but in the present embodiment, an electrode type water level detector is used. That is, the low water level detection electrode rod 26 is inserted into the heat source water tank 6, and it is monitored whether the water level in the heat source water tank 6 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).

  FIG. 2 is a diagram illustrating an example of a control method of the feed water heating system 1 according to the present embodiment. In this embodiment, water supply to the water supply tank 3 via the water supply path 8 and the output of the heat pump 4 are controlled based on the operating state of the boiler 2. That is, the feed water pump 10 and the heat pump 4 (particularly, the compressor 13) are controlled based on the boiler operation signal of the boiler controller.

  As described above, in this embodiment, the boiler 2 is in three positions: a high combustion state (100% combustion), a low combustion state (for example, 50% combustion), and a stop depending on the use load of steam in the steam using facility. The amount of fuel is adjusted. Further, the heat pump 4 is switched between operation and stop depending on whether or not the compressor 13 is operated, so that high load operation (full load operation = 100% output), low load operation (for example, 50% output), and stop (0% output). ) Controlled in three positions.

  On the other hand, the water supply pump 10 is interlocked with the operation of the heat pump 4, the water supply pump 10 is also operated while the heat pump 4 is being operated, and the water supply pump 10 is also stopped while the heat pump 4 is being stopped. However, strictly speaking, when the compressor 13 of the heat pump 4 is started, the water supply pump 10 is operated first. Further, as described above, the rotation speed of the feed water pump 10 is inverter-controlled so that the detected temperature of the water temperature sensor 22 is maintained as desired during operation. As a result, it is possible to supply water to the water supply tank 3 through the water supply path 8 at a higher flow rate during high load operation of the heat pump 4 than during low load operation.

  In the present embodiment, the amount of water supply corresponding to the evaporation amount of one boiler 2 can be covered by the water supply via one heat pump 4. Specifically, the amount of water supply corresponding to the amount of evaporation in the high combustion state of the boiler 2 can be covered by supplying water through the water supply path 8 while operating the heat pump 4 at a high load, and the low combustion state of the boiler 2. The amount of water supply corresponding to the amount of evaporation can be covered by supplying water via the water supply path 8 while operating the heat pump 4 at a low load.

  Therefore, in this embodiment, as shown in FIG. 2, when the boiler 2 is stopped, the heat pump 4 is also stopped accordingly, and the water supply to the water supply tank 3 through the water supply path 8 is stopped. do it. Further, when the boiler 2 is in a low combustion state, the heat pump 4 may be supplied to the water supply tank 3 through the water supply path 8 while operating the heat pump 4 at a low load. Furthermore, when the boiler 2 is in a high combustion state, water may be supplied to the water supply tank 3 via the water supply path 8 while operating the heat pump 4 at a high load accordingly.

  Thus, the operation signal of the boiler 2 (high combustion, low combustion or stop signal of the boiler controller) is provided so as to cover the amount of water supplied from the water supply tank 3 to the boiler 2 in accordance with the amount of evaporation of the boiler 2. ), Water can be supplied from the replenishing water tank 5 to the water supply tank 3 through the water supply path 8 via the heat pump 4 while controlling the heat pump 4.

  When the heat pump 4 is operated to supply water from the make-up water tank 5 to the water supply tank 3 through the water supply path 8, the water supplied from the make-up water tank 5 is used as the waste heat recovery heat exchanger 12, the supercooler 17, and the condenser. 14 is gradually heated and supplied to the water supply tank 3 at a predetermined temperature. Compared with the case where water is circulated between the water supply tank 3 and the heat pump 4, the water supply is heated by a single pass (once through) from the makeup water tank 5 to the water supply tank 3, so that it passes through the heat pump 4. It is possible to secure a temperature difference between before and after the water supply and improve the coefficient of performance (COP) of the heat pump 4. Furthermore, the system efficiency of the feed water heating system 1 can be improved by the heat pump 4 and the waste heat recovery heat exchanger 12.

  By the way, if the water level in the water supply tank 3 falls below the lower limit water level, the makeup water pump 11 should be operated. Specifically, when the water level in the water supply tank 3 falls and the low water level detection electrode rod 24 does not detect the water level, the makeup water pump 11 is operated until the water level returns to a predetermined water level or a predetermined time elapses. It is preferable to recover the water level in the water supply tank 3.

  If the water level in the heat source water tank 6 falls below the lower limit water level, the heat pump 4 and the heat source supply pump 21 should be stopped. Specifically, when the water level in the heat source water tank 6 falls and the low water level detection electrode rod 26 no longer detects the water level, the operation of the heat pump 4 is stopped and the heat source supply pump 21 is stopped to the evaporator 16. It is better to stop the supply of heat source water.

  Further, during operation of the heat pump 4, that is, during water supply to the water supply tank 3 through the water supply path 8, the water temperature in the heat source water tank 6 is monitored by a heat source temperature sensor (not shown), and the heat pump 4 The output may be adjusted (corrected). That is, the output% of the heat pump 4 may be changed according to the detected temperature of the heat source temperature sensor. The higher the temperature of the heat source water as the heat source of the heat pump 4, the lower the output% during operation of the heat pump 4. By adjusting the output during operation 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 8 can be stabilized regardless of the temperature change of the heat source water.

  FIG. 3 is a diagram illustrating a modification of the control method of the feed water warming system 1 of the present embodiment. In the said Example, although the boiler 2 and the heat pump 4 were each set as 1 unit | set, it is good also considering one or both among the boiler 2 and the heat pump 4 as multiple units | sets. When there are a plurality of boilers 2, the water supply from the water supply tank 3 is distributed to each boiler 2, and when there are a plurality of heat pumps 4, a water supply path 8 is installed in parallel between the makeup water tank 5 and the water supply tank 3. In the middle of each water supply channel 8, a condenser 14 of another heat pump 4 is arranged.

  In this case, the number of operating heat pumps 4 and the output of each heat pump 4 may be increased or decreased as the number of operating boilers 2 and the combustion amount of each boiler 2 increase or decrease. For example, when all the boilers 2 are stopped, all the heat pumps 4 are also stopped accordingly, and water supply to the water supply tank 3 via the water supply path 8 may be stopped. Further, when one boiler 2 is in a low combustion state, water may be supplied to the water supply tank 3 via the water supply passage 8 while operating one heat pump 4 at a low load accordingly. Further, when one boiler 2 is in a high combustion state or two boilers 2 are in a low combustion state, one heat pump 4 is operated at a high load in response to the supply water tank 3 via the water supply path 8. You only need to supply water. Similarly, the number of operating pumps and the output of the heat pumps 4 may be increased as the number of operating boilers 2 and the amount of combustion increase. Conversely, when the number of operating boilers 2 and the amount of combustion decrease, the number of operating heat pumps 4 and the output may be decreased according to the decrease.

  However, when operating a plurality of heat pumps 4 at the same time, it is preferable to set the number of low-load operation to a maximum of one. For example, when one boiler 2 is in a high combustion state or two boilers 2 are in a low combustion state, two heat pumps 4 are not operated at a low load, but one heat pump 4 is operated at a high load. Is good. By operating the heat pump 4 with as high an output as possible, the thermal efficiency of the feed water heating system 1 can be improved.

  By the way, in the said Example and modification, although the water supply to the water supply tank 3 via the water supply path 8 and the output of the heat pump 4 were controlled based on the operation state of the boiler 2, the water supply state from the water supply tank 3 to the boiler 2 is controlled. Based on the above, the water supply to the water supply tank 3 via the water supply path 8 and the output of the heat pump 4 may be controlled. Specifically, the output of the heat pump 4 may be controlled based on the operation state of the feed water pump 7 from the feed water tank 3 to the boiler 2 or the feed water flow rate from the feed water tank 3 to the boiler 2. For example, the heat pump 4 may be controlled based on the operation signal of the water supply pump 7 provided in the water supply path from the water supply tank 3 to the boiler 2. Alternatively, as shown by a two-dot chain line in FIG. 1, a flow switch, a flow sensor 27, and the like may be provided in a water supply path from the water supply tank 3 to the boiler 2, and the heat pump 4 may be controlled based on the flow switch.

  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. In particular, if the water supply to the water supply tank 3 via the water supply path 8 and the output of the heat pump 4 can be controlled based on the operation state of the boiler 2 or the water supply state from the water supply tank 3 to the boiler 2, the other configurations are appropriately set. It can be changed. In short, it is only necessary to grasp the water supply request to the boiler 2 and to supply water to the water supply tank 3 while heating with the heat pump 4 accordingly.

  Moreover, in the said Example, the example which controlled the heat pump 4 in three positions, a high load driving | operation, a low load driving | operation, and a stop was shown in connection with controlling the boiler 2 in three positions. When controlling at four positions (100% combustion), medium combustion state (for example, 80% combustion), low combustion state (for example, 50% combustion) and stop, the heat pump 4 is also operated at high load (typically full load operation = 100% output), medium load operation (for example, 80% output), low load operation (for example, 50% output), and control at four positions such as stop, etc. May be. And what is necessary is just to comprise so that the water supply corresponding to the evaporation amount in each combustion amount of the boiler 2 can be performed, heating with the heat pump 4. FIG.

  Moreover, the amount of evaporation of the boiler 2 and the amount of water supplied via the heat pump 4 are not limited to the case where one boiler 2 and one heat pump 4 correspond, and one boiler 2 and two heat pumps 4, Two boilers 2 and one heat pump 4 can be appropriately changed.

  Moreover, in the said Example, although the combustion amount is adjusted in steps in the boiler 2, the proportional control boiler which adjusts a combustion amount continuously may be sufficient, and the evaporation amount according to the combustion amount is covered in that case. As described above, water may be supplied to the water supply tank 3 through the water supply path 8 while proportionally controlling the output of the heat pump 4. Furthermore, in the said Example, although the boiler 2 was a fuel-fired boiler, it is applicable similarly to an electric boiler.

  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 4 includes a single-stage multi-stage heat pump, a multi-element (multi-element) heat pump, or a combination of them.

  Further, if water can be supplied to the water supply tank 3 through the water supply channel 8 via the condenser 14 and water can be supplied through the replenishment water channel 9 without going through the condenser 14, the specifics of the water supply channel 8 and the water supply channel 9 are specified. The configuration is not limited to the configuration of the above embodiment and can be changed as appropriate. For example, in the above-described embodiment, the water supply channel 8 and the supply water channel 9 are provided in parallel so as to connect the supply water tank 5 and the water supply tank 3, respectively, but one end portion of the water supply channel 8 and the supply water channel 9 ( 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 of the makeup water channel 9 may be provided so as to branch from the water supply channel 8 instead of being connected to the makeup water tank 5, and the other end of the makeup water channel 9 is connected to the water supply tank 3. Instead, it may be provided so as to join the water supply path 8 before the water supply tank 3. When one end portion of the replenishment water channel 9 is provided so as to branch from the water supply channel 8 instead of being connected to the replenishment water tank 5, the water supply pump 10 is provided in the water supply channel 8 downstream from the branching unit, while the replenishment water channel 9 may be provided with a supplementary water pump 11, but a pump is provided only in the common pipe upstream of the branching portion, and the valves provided in the water supply passage 8 and / or the supplementary waterway 9 downstream of the branching portion are opened. By adjusting the degree, the flow rate through the water supply channel 8 and the replenishment channel 9 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 8 and the supplement may be directly from a water supply source. Water may be passed through the water channel 9.

  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 8, the water supply pump 10 was inverter-controlled, However, The water supply pump 10 was provided in the water supply path 8 while performing on-off control. The opening degree of the valve may be adjusted. That is, if the flow rate of the water supply through the water supply path 8 can be adjusted based on the temperature detected by the water temperature sensor 22, the flow rate adjustment method can be changed as appropriate.

  Moreover, in the said Example, although it was made possible to supply water from the makeup water tank 5 to the water supply tank 3 via the water supply channel 8 and / or the makeup water channel 9, these water supply may be performed directly from a water softener. For example, in FIG. 1, instead of omitting the installation of the water supply pump 10 by connecting the base ends of the water supply channel 8 and the makeup water channel 9 together to the water softener, the opening of an electric valve (motor valve) provided in the water supply channel 8 Instead of adjusting the degree and omitting the installation of the makeup water pump 11, the opening and closing of the electromagnetic valve provided in the makeup water channel 9 may be controlled.

  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.

1 Water supply heating system 2 Boiler 3 Water supply tank 4 Heat pump 5 Supply water tank 6 Heat source water tank 7 Pump (water supply pump from water supply tank to boiler)
DESCRIPTION OF SYMBOLS 8 Water supply path 9 Supply water path 10 Supply water pump 11 Supply water pump 12 Waste heat recovery heat exchanger 13 Compressor 14 Condenser 15 Expansion valve 16 Evaporator 17 Subcooler 18 Supply path 19 Overflow path 20 Heat source supply path 21 Heat source supply pump 22 Water temperature sensor 23 Water level detector (for water supply tank) 24 Low water level detection electrode rod (for water supply tank) 25 Water level detector (for heat source water tank) 26 Low water level detection electrode rod (for heat source water tank) 27 Flow rate sensor

Claims (6)

A heat pump whose output can be changed,
A water supply tank capable of supplying water by a water supply channel via a condenser of the heat pump, and capable of supplying water by a replenishment water channel without using the condenser,
A boiler that is supplied with water from this water supply tank,
Water supply heating system characterized by controlling water supply to the water supply tank via the water supply path and output of the heat pump based on an operation state of the boiler or a water supply state from the water supply tank to the boiler. . The amount of water flow to the condenser is adjusted so that the outlet water temperature of the condenser of the heat pump is maintained at a set temperature during water supply to the water supply tank via the water supply path. Water supply heating system described in 1. The heat pump is controlled at least at three positions of high load operation, low load operation and stop,
The boiler is controlled at least in three positions, a high combustion state, a low combustion state, and a stop,
When the boiler is in a high combustion state, the heat pump is operated at a high load,
When the boiler is in a low combustion state, the heat pump is operated at a low load,
The feed water warming system according to claim 1 or 2, wherein the heat pump is stopped when the boiler is stopped. The output of the heat pump is controlled based on the operation state of the water supply pump from the water supply tank to the boiler or the flow rate of water supply from the water supply tank to the boiler. Water heating system. A plurality of the heat pump and the boiler are provided,
The supply water heating according to any one of claims 1 to 3, wherein the number of operating heat pumps and the output of each heat pump are increased or decreased as the number of operating boilers and the amount of combustion in each boiler increase or decrease. system. The feed water heating system according to any one of claims 1 to 5, wherein when the water level of the feed water tank falls below a setting, water is supplied to the feed water tank even through the makeup water channel.

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