JP2013234790A - Water supply heating system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To efficiently supply water to a water tank promptly according to a use load of water stored in the water tank, in a water supply heating system that uses a heat pump.SOLUTION: Water can be supplied to a water tank 3 by a water supply channel 8 through a condenser 14 of a heat pump 4, as well as by a replenishing water channel 9 without using the condenser 14. Output of the heat pump 4 is controlled based on a fluctuation speed of a water level of the water tank 3. Preferably, during supplying water to the water tank 3 through the water supply channel 8, a water supply pump 10 is inverter-controlled based on the temperature detected by a water temperature sensor 22, and the volume of water to be supplied to the condenser 14 is regulated to maintain the water temperature on the outlet side of the condenser 14 at a preset temperature.

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 heating system comprising: a water supply tank capable of supplying water through a replenishment water channel without passing through the condenser, and controlling an output of the heat pump based on a fluctuation speed of a water level in the water supply tank.

  According to the first aspect of the present invention, by controlling the output of the heat pump based on the fluctuation speed of the water level in the water supply tank, water supply to the water supply tank is performed according to the usage load of the stored water in the water supply tank. It can be done quickly and efficiently.

  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 of the heat pump is adjusted so that the outlet water temperature of the condenser of the heat pump is maintained at the set temperature. The amount of water supplied to the water tank via the road will increase. Therefore, if the output of the heat pump is controlled based on the fluctuation speed of the water level in the water supply tank, the water supply to the water supply tank can be performed quickly and efficiently according to the usage load of the stored water in the water supply tank. Also, by adjusting the water flow rate to the condenser so that the water temperature on 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 path, the water supply temperature via the water supply path is adjusted. It can be maintained as desired.

  According to a third aspect of the present invention, when the water level in the water supply tank rises, the output of the heat pump is reduced compared to when the water level is lowered, or the output of the heat pump is reduced as the water level rise speed is faster, or the water level rise speed When the water level is higher than a set value, the heat pump is stopped, and at least one control is performed, and when the water level in the water supply tank is lowered, the output of the heat pump is increased more than when the water level is raised, The higher the speed is, the more the output of the heat pump is increased, or when the water level lowering speed is equal to or higher than a set value, the water supply tank is supplied with water through the make-up water channel. The feed water warming system according to claim 1 or claim 2.

  According to the third aspect of the present invention, the water supply to the water supply tank is controlled while controlling the output of the heat pump based on whether the water level in the water supply tank is rising or falling, or based on the rising speed or the falling speed of the water level in the water supply tank. By controlling, water supply to the water supply tank can be performed quickly and efficiently according to the usage load of the stored water in the water supply tank.

  According to a fourth aspect of the present invention, the heat pump can be switched between a low load operation and a high load operation with a higher output than that, the water level in the water supply tank is rising, and the water level rising speed (V) Is equal to or greater than a set value (V1) (V1 ≦ V), the heat pump is stopped and water supply to the water supply tank is stopped via the water supply channel and the replenishment water channel, and the water level in the water supply tank is reduced. When rising and the water level rising speed (V) is less than a set value (V1) (0 <V <V1), water is supplied to the water supply tank through the water supply path while operating the heat pump at a low load, When the water level in the water supply tank is descending and the water level descending speed (| V |) is less than a set value (V1) (0 <| V | <V1), the water supply is performed while operating the heat pump at a high load. The water tank through the road When water is supplied and the water level in the water supply tank is descending and the water level descending speed (| V |) is equal to or higher than a set value (V1) (V1 ≦ | V |), the heat pump is operated at a high load while The water supply and heating system according to any one of claims 1 to 3, wherein water is supplied to the water supply tank via a water supply path and also supplied to the water supply tank via the replenishment water path. .

  According to invention of Claim 4, according to the fluctuation speed of the water level in a water supply tank, the output of a heat pump, the water supply to a water supply tank via a water supply channel, and the water supply to a water supply tank via a replenishment water channel are carried out. By switching, the water supply to the water supply tank can be easily controlled according to the usage load of the stored water in the water supply tank.

  According to a fifth aspect of the present invention, when the water level in the water supply tank falls below a lower limit water level, the water supply tank is operated via the water supply channel while operating the heat pump regardless of the fluctuation speed of the water level in the water supply tank. Water is supplied to the water supply tank via the replenishment water channel, and when the water level in the water supply tank exceeds the upper limit water level, the heat pump is stopped regardless of the fluctuation speed of the water level in the water supply tank. The feed water heating system according to any one of claims 1 to 4, wherein water supply to the water supply tank via the water supply channel and the makeup water channel is stopped.

  According to the invention described in claim 5, when the water level in the water supply tank falls below the lower limit water level, water is forcibly supplied to the water supply tank via the water supply channel and the makeup water channel, while the water level in the water supply tank has the upper limit water level. If it exceeds, water supply to the water supply tank through the water supply channel and the supply water channel will be forcibly stopped. Thereby, while maintaining the water level in a water supply tank more than the minimum, it can prevent overflowing.

  The invention according to claim 6 adjusts the output at the time of low load operation of the heat pump based on the temperature of the heat source fluid passed through the evaporator of the heat pump. It is a temperature system.

  According to the sixth aspect of the present invention, by adjusting the output at the time of low load operation of the heat pump in consideration of the temperature of the heat source fluid, regardless of the temperature change of the heat source fluid, to the water supply tank via the water supply channel The feed water flow rate can be stabilized.

  Further, the invention according to claim 7 stops the operation of the heat pump and stops the supply of the heat source fluid to the evaporator when the amount of the heat source fluid passed through the evaporator of the heat pump falls below a setting. It is a feed water heating system of any one of Claims 1-6 characterized by the above-mentioned.

  According to the seventh aspect of the present invention, when the heat source fluid of the heat pump is exhausted, the operation of the heat pump can be stopped.

  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.

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 water supply path from the water supply tank 3 to 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.

  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. Using this, in this embodiment, the heat pump 4 draws heat from the heat source water passing through the heat source supply path 20 as a heat source in the evaporator 16, and warms the water in the water supply path 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 its output (the capacity of the compressor 13). 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. 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 means for monitoring the fluctuation speed of the water level in the water supply tank 3. The configuration of the monitoring means is not particularly limited. In this embodiment, the monitoring means is an analog water level detector 23 that can obtain an output corresponding to the water level. 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.

  The fluctuation speed V of the water level is a change in the water level per unit time, but can also be referred to as a fluctuation water level within a predetermined time, in other words, a fluctuation range of the water level within a certain time. Although details will be described later with reference to FIG. 2, in this embodiment, if the water level rises within a predetermined time, the fluctuation speed V is positive, and if the water level falls within the predetermined time, the fluctuation speed V is negative. Accordingly, it can be said that the positive fluctuation speed V is an ascending speed and the negative fluctuation speed V is a descending speed. And when it is called a descending speed, it is obvious that the water level is descending, so the absolute value | V | of the fluctuation speed V is used. That is, in the case of the fluctuation speed V, it may be positive or negative, but in the case of the ascending speed or the falling speed, the absolute value | V | of the fluctuation speed V is always positive.

  The water level detector 23 further detects that the water level in the water supply tank 3 has fallen below the lower limit water level, and also detects that the water level in the water supply tank 3 has exceeded the upper limit water level. As a result, it is possible to detect the water level in the water supply tank 3 before it runs out of water or overflows. The water level detector for detecting the lower limit water level and the upper limit water level may be configured separately from the water level detector for monitoring the water level fluctuation speed.

  The heat source water tank 6 is provided with a water level detector 24 that detects that the water level has dropped below the setting. The configuration of the water level detector 24 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 25 is inserted into the heat source water tank 6, and it is monitored whether the water level of the heat source water is below the setting. The heat source water tank 6 may be provided with a heat source temperature sensor 26 that detects the temperature of the heat source water.

  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. As shown in this figure, the heat pump 4 (particularly the compressor 13), the feed water pump 10, and the makeup water pump 11 are controlled based on the fluctuation speed V of the water level in the feed water tank 3.

  The output of the heat pump 4 is controlled based on the fluctuation speed V of the water level in the water supply tank 3. When the water level in the water supply tank 3 rises, the output of the heat pump 4 is decreased than when the water level is lowered, or the output of the heat pump 4 is reduced as the water level rise speed | V | is faster, or the water level rise speed | V | It is preferable to perform at least one control of stopping the heat pump 4 when it becomes V1 or higher (faster than the set value V1). Conversely, when the water level in the water supply tank 3 is lowered, the output of the heat pump 4 is increased more than when the water level is raised, or the output of the heat pump 4 is increased as the water level lowering speed | V | is faster, or the water level lowering speed | V | When the value becomes equal to or higher than the set value V1 (becomes faster than the set value V1), it is preferable to control at least one of the water supply to the water supply tank 3 through the replenishment water channel 9. The fluctuation level V of the water level (water level rising speed | V |, water level falling speed | V |) is determined by the controller based on the detection signal from the water level detector 23 at regular intervals.

  In the present embodiment, the control is performed as shown in FIG. Here, the heat pump 4 is switched between operation and stop depending on whether or not the compressor 13 is activated. Further, as described above, in this embodiment, the heat pump 4 is operated at a high load (typically full load operation = 100% output), a low load operation (for example, 50% output), and stopped (0% output). Are controlled in three positions. Further, the feed water pump 10 is interlocked with the operation of the heat pump 4, the feed water pump 10 is also operated while the heat pump 4 is being operated, and the feed water pump 10 is also stopped while the heat pump 4 is being stopped. However, as described above, the rotation speed of the water supply pump 10 is inverter-controlled so as to maintain a desired temperature detected by the water temperature sensor 22 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.

  Hereinafter, the control of FIG. 2 will be described in more detail. Note that V is the fluctuation speed of the water level in the water supply tank 3, and takes a positive value while the water level is rising and a negative value while the water level is falling, as described above. V1 is a set value (set speed) preset in the controller.

(1) When V1 ≦ V.
When the water level in the water supply tank 3 is rising and the water level rising speed | V | is not less than the set value V1 (V1 ≦ | V |), the heat pump 4 is stopped and the water supply pump 10 is stopped, Water supply to the water supply tank 3 through the water supply path 8 is stopped. At this time, the operation of the makeup water pump 11 is also stopped, and water is not supplied to the water supply tank 3 through the makeup water channel 9. Thereby, the water supply to the water supply tank 3 through the water supply path 8 and the replenishment water path 9 is stopped.

(2) When 0 <V <V1.
When the water level in the water supply tank 3 is rising and the water level rising speed | V | is less than the set value V1 (0 <| V | <V1), the heat pump 4 is operated at a low load via the water supply path 8. To supply water to the water supply tank 3. At this time, the makeup water pump 11 stops operating, and water is not supplied to the feed water tank 3 through the makeup water channel 9.

(3) When -V1 <V <0.
When the water level in the water supply tank 3 is descending and the water level descending speed | V | is less than the set value V1 (0 <| V | <V1), the heat pump 4 is operated through the water supply channel 8 while operating at a high load. To supply water to the water supply tank 3. At this time, the makeup water pump 11 stops operating, and water is not supplied to the feed water tank 3 through the makeup water channel 9.

(4) V ≦ −V1
When the water level in the water supply tank 3 is lowering and the water level lowering speed | V | is equal to or higher than the set value V1 (V1 ≦ | V |), water is supplied through the water supply path 8 while operating the heat pump 4 at a high load. While supplying water to the tank 3, the replenishment water pump 11 is also operated to supply water to the water supply tank 3 via the replenishment water channel 9.

  In the above (1) to (4), V = 0, that is, the case where the water level in the water supply tank 3 does not fluctuate was not mentioned, but in this case, the control need not be changed. That is, for example, as described in (3) above, assuming that −V1 <V <0, the water level does not change during water supply to the water supply tank 3 via the water supply path 8 while operating the heat pump 4 at a high load. Next, the current control may be maintained (here, the heat pump 4 is operated at a high load) until the water level fluctuates. However, when the fluctuation of the water level disappears, the heat pump 4 may be supplied to the water supply tank 3 through the water supply path 8 while operating at a low load. That is, although the condition for performing the control (2) is “0 <V <V1”, this may be “0 ≦ V <V1” (0 ≦ | V | <V1).

  The feed water warming system 1 of the present embodiment is controlled as described above. When the heat pump 4 is operated to feed water from the make-up water tank 5 to the feed water tank 3 through the feed water path 8, the make-up water tank The feed water from 5 is gradually heated by the waste heat recovery heat exchanger 12, the supercooler 17 and the condenser 14, and is supplied to the feed water 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, due to the requirement of the water level fluctuation speed V, even if the feed water pump 10 and the makeup water pump 11 are stopped, if the water level in the feed water tank 3 falls below the lower limit water level, the feed water pump 10 and the makeup water pump 11 are operated. Is good. Specifically, when it is detected that the water level in the water supply tank 3 has dropped and the water level detector 23 has fallen below the lower limit water level, the water level in the water supply tank 3 returns to the predetermined water level regardless of the fluctuation speed V of the water level, or Until the predetermined time elapses, water is supplied to the water supply tank 3 through the water supply path 8 while operating the heat pump 4 at a high load, and the water supply tank 3 is also operated to supply water to the water supply tank 3 through the supply water path 9. It is preferable to restore the water level in the water supply tank 3. Then, after that, it is only necessary to return to normal control (control based on the water level fluctuation speed V). In this way, depletion of the stored water in the water supply tank 3 can be prevented beforehand.

  On the contrary, due to the requirement of the water level fluctuation speed V, even if the feed water pump 10 and the makeup water pump 11 are in operation, if the water level in the feed water tank 3 exceeds the upper limit water level, the feed water pump 10 and the makeup water pump 11 are stopped. It is good. Specifically, when the water level in the water supply tank 3 rises and the water level detector 23 detects that the water level has exceeded the upper limit water level, the water level in the water supply tank 3 returns to a predetermined water level regardless of the fluctuation speed V of the water level, or It is preferable to stop the heat pump 4 and stop water supply to the water supply tank 3 through the water supply path 8 and the replenishment water path 9 until a predetermined time elapses. Then, after that, it is only necessary to return to normal control (control based on the water level fluctuation speed V). In this way, overflow from the water supply tank 3 can be prevented in advance.

  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 25 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, 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 the heat source temperature sensor 26, and the heat pump 4 (particularly low load) is monitored based on the temperature. The output during operation may be adjusted (corrected). That is, the output% of the heat pump 4 may be changed according to the temperature detected by the heat source temperature sensor 26. 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.

  If any trouble occurs during the operation of the feed water warming system 1, it is preferable to stop the operation of the heat pump 4 and stop the heat source supply pump 21 to stop the supply of the heat source fluid to the evaporator 16. . For example, in the unlikely event that the water level in the makeup water tank 5 falls below the lower limit water level, the operation of the heat pump 4 is stopped and the heat source supply pump 21 is stopped to stop the supply of the heat source fluid to the evaporator 16. Is good. In addition, if the measured flow rate in the water supply channel 8 becomes a predetermined value or less during water supply through the water supply channel 8, it is assumed that the water supply channel 8 is clogged, so the operation of the heat pump 4 is stopped. At the same time, it is preferable to stop the supply of the heat source fluid to the evaporator 16 by stopping the heat source supply pump 21.

  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, the configuration is not limited to the configuration of FIG. 2 as long as the configuration supplies water to the water supply tank 3 while controlling the output of the heat pump 4 based on the fluctuation speed V of the water level in the water supply tank 3. That is, in FIG. 2, although the control pattern was divided into four according to the water level fluctuation | variation speed V, you may prescribe | regulate a control pattern further finely.

  And when the control pattern which makes the heat pump 4 carry out low load operation at the time of a water level rise and the time of a water level fall appears, the output at the time of low load operation of the heat pump 4 is the direction when the water level of the water supply tank 3 is lowered than when the water level rises May be set to a high output.

  Moreover, although the example which controlled the heat pump 4 in the three positions of high load operation, low load operation, and a stop was shown in the said Example, the heat pump 4 is high load operation (typically full load operation = 100% output). Control may be performed at four or more positions, such as medium load operation (for example, 80% output), low load operation (for example, 50% output), and stop.

  Moreover, in the said Example, although the setting value V1 for dividing | segmenting a control pattern was made into the value mutually corresponding at the time of a water level rise and a water level fall, it is good also as a mutually different value.

  Moreover, in the said Example, although 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, according to the fluctuation speed V of the water level in the water supply tank 3, the output of the heat pump 4 is shown. You may control continuously (inverter control of the compressor 13).

  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.

  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.

  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.

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 7 Pump 8 Supply water path 9 Supply water channel 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 24 (for water supply tank) Water level detector 24 (for heat source water tank) 25 Low water level detection electrode rod 26 Heat source temperature sensor

Claims (7)

A heat pump whose output can be changed,
A water supply tank capable of supplying water by a water supply path via a condenser of the heat pump, and having a water supply tank capable of supplying water by a replenishment water path without passing through the condenser,
The feed water heating system characterized by controlling the output of the heat pump based on the fluctuation speed of the water level in the feed water tank. 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. When the water level in the water tank rises, the output of the heat pump is reduced compared to when the water level is lowered, or the output of the heat pump is reduced as the water level rise speed is faster, or when the water level rise speed exceeds a set value, the heat pump is turned off. Do one or more of the controls to stop,
When the water level in the water supply tank is lowered, the output of the heat pump is increased as compared to the time when the water level is raised, or the output of the heat pump is increased as the water level lowering speed is faster, or when the water level lowering speed exceeds a set value, The feed water warming system according to claim 1 or 2, wherein at least one of the water supply to the water supply tank is controlled through the control. The heat pump can be switched between a low load operation and a high load operation with a higher output than this,
When the water level in the water supply tank is rising and the water level rising speed (V) is equal to or higher than a set value (V1) (V1 ≦ V), the heat pump is stopped and the water supply channel and the makeup water channel are passed through. Stop water supply to the water tank,
When the water level in the water supply tank is rising and the water level rising speed (V) is less than a set value (V1) (0 <V <V1), the heat pump is operated with a low load through the water supply channel. Supplying water to the water supply tank;
When the water level in the water supply tank is descending and the water level descending speed (| V |) is less than a set value (V1) (0 <| V | <V1), the water supply is performed while operating the heat pump at a high load. Water is supplied to the water supply tank via the road,
When the water level in the water supply tank is descending and the water level descending speed (| V |) is equal to or higher than a set value (V1) (V1 ≦ | V |), the heat pump is operated at a high load, The water supply heating system according to any one of claims 1 to 3, wherein water is supplied to the water supply tank via the water supply tank, and water is supplied to the water supply tank via the supply water channel. When the water level in the water supply tank falls below the lower limit water level, water is supplied to the water supply tank through the water supply path while operating the heat pump regardless of the fluctuation speed of the water level in the water supply tank, Even through the water tank,
When the water level in the water supply tank exceeds the upper limit water level, the heat pump is stopped regardless of the fluctuation speed of the water level in the water supply tank, and water is supplied to the water supply tank via the water supply channel and the makeup water channel. It stops. The feed water heating system of any one of Claims 1-4 characterized by the above-mentioned. The feed water heating system according to claim 4, wherein an output at the time of low load operation of the heat pump is adjusted based on a temperature of a heat source fluid passed through an evaporator of the heat pump. When the amount of the heat source fluid passed through the evaporator of the heat pump falls below a setting, the operation of the heat pump is stopped and the supply of the heat source fluid to the evaporator is stopped. The feed water heating system according to any one of the above.

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