JP2005195211A - Heat pump water heater - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a heat pump water heater having a reduced size without causing runout of hot water. <P>SOLUTION: The heat pump water heater comprises a refrigerant circuit 5 consisting of a compressor 1, a radiator 2, a pressure reducer 3, and an air heat exchanger 4, a water circuit to which a hot water storage tank 6, a circulation pump 7, and the radiator 2 are connected, and a hot water supply circuit 17. The hot water supply circuit 17 is connected to the water circuit 9, a water pipe 10 for supplying city water, and a tapping pipe 11 for tapping hot water from the hot water storage tank 6. The tapping pipe 11 and an outlet pipe from the radiator 2 are connected to a first mixing valve 12, and the first mixing valve 12 and a city water pipe 13 are connected to a second mixing valve 14. The outlet pipe of the second mixing valve 14 is connected to a hot water supply terminal 15 and a bathtub 16. The refrigerant circuit 5 is operated in accordance with a tapping signal for supplying hot water heated by the water circuit 9 and hot water in the hot water storage tank 6 at the same time which are mixed with city water with the second mixing valve 14 and tapped at a preset temperature. Thus, the capacity of the hot water storage tank 6 is reduced, and thus the size of the heat pump water heater is reduced. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a heat pump water heater using a heat pump.

FIG. 8 shows a typical configuration of a conventional heat pump water heater (see, for example, Patent Document 1). As shown in FIG. 8, this type of heat pump water heater includes a refrigerant circuit 5 including a compressor 1, a radiator 2, a decompression device 3, and an air heat exchanger 4, a hot water tank 6, a circulation pump 7, and a radiator 2. It is comprised from the water circuit 9 which connected. The air heat exchanger 4 of the refrigerant circuit 5 absorbs heat from the atmosphere and dissipates heat from the radiator 2, and heats water supplied from the lower part of the hot water storage tank 6 to the heat radiator 2 via the circulation pump 7 to the hot water storage tank 6. The hot water stored in the hot water storage tank 6 is circulated to supply hot water.
In this conventional configuration, hot water heated by operating a heat pump water heater at night using electric power in the night is stored in the hot water storage tank 6, and hot water stored in the hot water storage tank 6 and low-temperature city water are mixed in the daytime. Hot water at a predetermined temperature is supplied.
JP 2000-346447 A

  However, when the amount of hot water used during the day (hot water supply load) is large, the hot water in the hot water storage tank 6 is insufficient. Therefore, the hot water storage tank 6 having a large hot water storage capacity must be used to cope with the hot water supply load. However, the hot water storage tank 6 having a large hot water storage capacity has a problem that it requires a large installation area of the equipment.

  The present invention solves the above-described conventional problems, and an object of the present invention is to provide a small heat pump water heater sufficiently corresponding to a hot water supply load.

The heat pump water heater of the present invention according to claim 1 is a refrigerant circuit in which a compressor, a radiator, a pressure reducing device, and an air heat exchanger are sequentially connected, a hot water tank, a circulation pump connected to a lower part of the hot water tank, and the heat radiation. A water circuit that sequentially connects a two-way valve and an upper part of the hot water tank, the lower part of the hot water tank is connected to a water supply pipe that supplies city water, and the upper part of the hot water tank is connected to a hot water pipe And a city water branched from the outlet pipe of the first mixing valve and the water supply pipe, wherein the branch pipe of the pipe connecting the radiator and the two-way valve and the outlet pipe are connected to the first mixing valve The piping is connected to a second mixing valve, and the outlet piping of the second mixing valve is connected to at least one of a hot water supply terminal and a bath tub.
According to a second aspect of the present invention, in the heat pump water heater according to the first aspect, a temperature sensor for detecting a temperature of water supplied from the lower part of the hot water storage tank to the radiator, and hot water heated by the radiator A hot water supply temperature sensor for detecting the temperature of the hot water storage tank, a plurality of remaining hot water temperature sensors for detecting the amount of hot water in the hot water storage tank, and a hot water temperature sensor for detecting the hot water temperature of the second mixing valve. The hot water heated by the radiator and the hot water in the hot water storage tank are mixed by the first mixing valve and supplied to the second mixing valve, and the first mixing is performed by the second mixing valve. The hot water from the valve and the city water are mixed and adjusted to a predetermined temperature.
The heat pump water heater of the present invention according to claim 3 is a refrigerant circuit in which a compressor, a radiator, a pressure reducing device, and an air heat exchanger are sequentially connected, a hot water tank, a circulation pump connected to a lower part of the hot water tank, and the heat radiation. A water circuit that sequentially connects a two-way valve and an upper part of the hot water tank, the lower part of the hot water tank is connected to a water supply pipe that supplies city water, and the upper part of the hot water tank is connected to a hot water pipe And a city water branched from the outlet pipe of the first mixing valve and the water supply pipe, wherein the branch pipe of the pipe connecting the radiator and the two-way valve and the outlet pipe are connected to the first mixing valve A pipe is connected to a second mixing valve, an outlet pipe of the second mixing valve is connected to a hot water supply terminal, a branch pipe of a pipe connecting the first mixing valve and the second mixing valve, and the city A branch pipe of the water pipe is connected to a third mixing valve, and the third mixing valve Outlet pipe is characterized in that it is connected to the bath tub.
According to a fourth aspect of the present invention, in the heat pump water heater according to the third aspect, a temperature sensor for detecting a temperature of water supplied to the radiator from a lower part of the hot water tank, hot water heated by the radiator Hot water temperature sensor for detecting the temperature of the hot water, a plurality of remaining hot water temperature sensors for detecting the amount of hot water in the hot water storage tank, a hot water temperature sensor for detecting the hot water temperature of the second mixing valve, and the hot water temperature of the third mixing valve A bath hot water temperature sensor for detecting the hot water, operating the refrigerant circuit in response to a hot water signal, mixing the hot water heated by the radiator and the hot water in the hot water storage tank with the first mixing valve. Supplying to the mixing valve and the third mixing valve, the hot water and the city water from the first mixing valve are mixed and adjusted to a predetermined temperature by the second mixing valve and the third mixing valve. It is characterized by that.
According to a fifth aspect of the present invention, in the heat pump water heater according to the second or fourth aspect, when hot water supply is started from the hot water supply terminal, hot water is supplied to the first mixing valve only from the hot water storage tank. And when the amount of remaining hot water of the said hot water storage tank becomes below a predetermined value, the said refrigerant circuit is operated and warm water is stored in the said hot water storage tank, It is characterized by the above-mentioned.
According to a sixth aspect of the present invention, in the heat pump water heater according to the fifth aspect, the refrigerant circuit is operated by a hot water supply signal to the bath tub so that the heating temperature of the water circuit is lower than the hot water temperature of the hot water tank. Further, the hot water in the hot water tank is supplied to the bath tub to maximize the supply amount of the hot water.
According to a seventh aspect of the present invention, in the heat pump water heater according to the sixth aspect, when the hot water is supplied to the bath tub, the refrigerant circuit is operated and the heating temperature of the water circuit is set to 35 ° C to 45 ° C. It is characterized by.
According to an eighth aspect of the present invention, in the heat pump water heater according to any one of the first to seventh aspects, the heating capacity Q of the refrigerant circuit and the capacity of the hot water tank are controlled to have a predetermined relationship. It is characterized by that.
According to a ninth aspect of the present invention, in the heat pump water heater according to the first or third aspect, a temperature sensor for detecting a temperature of water supplied to the water circuit from a lower part of the hot water tank, and an outdoor air temperature are detected. And a plurality of remaining hot water temperature sensors for detecting the amount of remaining hot water in the hot water storage tank, the heating capacity Q of the refrigerant circuit is calculated from the output value of the temperature sensor and the output value of the outdoor temperature sensor, When the amount of remaining hot water in the hot water storage tank is less than a predetermined value, the amount of hot water supplied from the hot water storage tank is decreased by a value calculated from the remaining hot water amount in the hot water storage tank and the heating capacity Q of the refrigerant circuit, When the amount of hot water supplied from the water circuit is increased and the remaining amount of hot water in the hot water storage tank is further reduced, the supply from the hot water tank is stopped and hot water is supplied only from the water circuit. .

The heat pump water heater of the present invention can reliably cope with various hot water loads, and can provide a small heat pump water heater without causing hot water to run out.
Also, the refrigerant circuit is not operated when a small amount of hot water is supplied, and the compressor circuit is operated when the amount of hot water supply is large or when the remaining hot water in the hot water tank is low, thereby reducing the number of times the compressor is operated and stopped. Thus, it is possible to provide a heat pump water heater with high device reliability.

The heat pump water heater according to the first embodiment of the present invention stores the hot water heated by the radiator of the refrigerant circuit in the hot water storage tank of the water circuit, and the hot water heated by the radiator and the hot water flowing out of the hot water storage tank are the first. The mixing valve is used, and the temperature is adjusted with city water using the second mixing valve and supplied to the hot water supply terminal and bath tub. According to the present embodiment, when hot water is supplied to a hot water supply terminal or a bath tub, a direct hot water supply operation in which hot water is supplied by operating the refrigerant circuit, a hot water supply operation in which hot water is supplied from the hot water tank without operating the refrigerant circuit, and hot water is supplied to the hot water tank. Different operation modes such as hot water storage operation to store water can be performed.
In the heat pump water heater according to the first embodiment, the second embodiment of the present invention is a temperature sensor that detects the temperature of water supplied to the radiator from the lower part of the hot water tank, and hot water heated by the radiator. A hot water supply temperature sensor for detecting the temperature of the hot water, a plurality of remaining hot water temperature sensors for detecting the amount of hot water in the hot water storage tank, and a hot water temperature sensor for detecting the hot water temperature at the outlet pipe of the second mixing valve. According to the present embodiment, based on the detection signals of these sensors, the hot water heated by the radiator and the hot water in the hot water tank are simultaneously supplied, and the city water is supplied by the second mixing valve or the third mixing valve. By mixing and discharging hot water at a predetermined temperature, the capacity of the hot water storage tank can be reduced, and the heat pump water heater can be reduced in size.
A heat pump water heater according to the third embodiment of the present invention stores hot water heated by a radiator of a refrigerant circuit in a hot water storage tank of a water circuit, and the hot water heated by the radiator and the hot water flowing out of the hot water storage tank are first. The temperature is adjusted with city water with the second mixing valve and supplied to the hot water supply terminal with the second mixing valve, and the temperature is adjusted with city water with the third mixing valve and supplied to the bath tub. . According to the present embodiment, the operation is different at different temperatures, such as a direct hot water supply operation in which hot water is supplied by operating the refrigerant circuit, a hot water supply operation in which hot water is supplied from a hot water tank without operating the refrigerant circuit, and a hot water storage operation in which hot water is stored in the hot water tank. Mode can be performed.
In the heat pump water heater according to the third embodiment, the fourth embodiment of the present invention is a temperature sensor that detects the temperature of water supplied to the radiator from the lower part of the hot water tank, and hot water heated by the radiator. A hot water supply temperature sensor for detecting the temperature of the hot water, a plurality of remaining hot water temperature sensors for detecting the amount of hot water in the hot water storage tank, and a hot water temperature sensor for detecting the hot water temperature at the outlet pipe of the second mixing valve. According to the present embodiment, based on the detection signals of these sensors, the hot water heated by the radiator and the hot water in the hot water tank are simultaneously supplied, and the city water is supplied by the second mixing valve or the third mixing valve. By mixing and discharging hot water at different predetermined temperatures, the capacity of the hot water storage tank can be reduced, and the heat pump water heater can be reduced in size.
In the heat pump water heater according to the second or fourth embodiment, the fifth embodiment of the present invention supplies hot water only to the first mixing valve from the hot water tank when hot water supply is started from the hot water supply terminal. When the remaining amount of hot water in the hot water storage tank becomes a predetermined value or less, the refrigerant circuit is operated to store hot water in the hot water storage tank. According to the present embodiment, the number of operations / stops of the compressor can be reduced, the reliability of the equipment can be increased, and the size of the hot water tank can be reduced.
In the heat pump water heater according to the fifth embodiment, the sixth embodiment of the present invention operates the refrigerant circuit by a hot water supply signal to the bath tub and lowers the heating temperature of the water circuit below the hot water temperature of the hot water tank. In addition, the hot water in the hot water tank is supplied to the bath tub to maximize the supply amount of the hot water. According to the present embodiment, the refrigerant circuit is operated by the hot water supply signal to the bath so that the heating temperature of the water circuit is lower than the hot water temperature of the hot water tank, so that the refrigerant circuit can be operated efficiently. Further, since hot water in the hot water tank is also supplied to the hot water supply circuit at the same time, hot water supply to the bath can be performed in a short time without causing hot water to run out by maximizing the supply amount of hot water.
7th Embodiment of this invention makes the heating temperature of the water circuit at the time of the hot water supply to a bath tub into 35 to 45 degreeC in the heat pump water heater by 6th Embodiment. According to the present embodiment, the refrigerant circuit can be operated more efficiently.
In the eighth embodiment of the present invention, in the heat pump water heater according to any one of the first to seventh embodiments, the heating capacity Q of the refrigerant circuit and the capacity of the hot water storage tank are controlled to have a predetermined relationship. Is. According to the present embodiment, hot water does not run out, and can sufficiently cope with hot water supply load.
The ninth embodiment of the present invention is a heat pump water heater according to the first or third embodiment, which is heated by a temperature sensor and a radiator for detecting the temperature of water supplied to the water circuit from the lower part of the hot water tank. The hot water supply temperature sensor that detects the temperature of the heated hot water, the outdoor air temperature sensor that detects the outdoor air temperature, and the remaining hot water temperature sensor that detects the amount of hot water in the hot water tank, the maximum heating capacity Q of the refrigerant circuit and the output value of the temperature sensor When the amount of remaining hot water in the hot water storage tank is less than a predetermined value, it is calculated based on the output value of the outdoor temperature sensor, so that the ratio is calculated from the amount of hot water in the hot water storage tank and the maximum heating capacity Q of the refrigerant circuit. If the amount of hot water supplied from the tank is decreased, the amount of hot water supplied from the water circuit is increased, and the remaining amount of hot water in the hot water tank is further reduced, the supply from the hot water tank is stopped and hot water is supplied only from the water circuit. Supply Than it is. According to the present embodiment, when the remaining amount of hot water in the hot water storage tank becomes smaller than a predetermined value, the hot water tank has a ratio calculated from the remaining hot water amount of the hot water storage tank and the maximum heating capacity Q of the refrigerant circuit. When the amount of hot water supplied is reduced, the amount of hot water supplied from the water circuit is increased, and the remaining amount of hot water in the hot water tank is further reduced, the supply from the hot water tank is stopped and hot water is supplied only from the water circuit. By supplying, it is possible to sufficiently cope with a hot water supply load without causing hot water shortage.

Hereinafter, a heat pump water heater in an embodiment of the present invention will be described with reference to the drawings.
FIG. 1 shows a configuration diagram of a heat pump water heater in a first embodiment of the present invention. The same constituent members as those in FIG.
In FIG. 1, the refrigerant circuit 5 includes a compressor 1, a radiator 2, a decompressor 3, and an air heat exchanger 4. The water circuit 9 includes a hot water tank 6, a circulation pump 7, a radiator 2, and a two-way valve 8 connected between the hot water tank 6 and the radiator 2. A water supply pipe 10 branched from a water supply valve 18 for supplying city water is connected to the lower part of the hot water tank 6, and a hot water discharge pipe 11 is connected to the upper part of the hot water tank 6. The outlet pipe 11 is connected by a first mixing valve 12 and a pipe connecting the radiator 2 of the water circuit 9 and the two-way valve 8. The outlet pipe of the first mixing valve 12 is connected to a city water pipe 13 branched from the water supply valve 18 via the second mixing valve 14, and the outlet pipe of the second mixing valve 14 is a hot water supply terminal 15 and a bath tub. 16 is connected to the hot water supply circuit 17.
Reference numeral 21 denotes a temperature sensor that detects the temperature of water derived from the lower part of the hot water tank 6, 22 denotes a hot water temperature sensor that detects the temperature of hot water heated by the radiator 2, and 23 detects the amount of hot water remaining in the hot water tank 6. A plurality of remaining hot water temperature sensors 24 are hot water temperature sensors for detecting the hot water temperature of the heat pump water heater.

About the heat pump water heater comprised as mentioned above, the operation | movement and an effect | action are demonstrated below.
First, when the refrigerant circuit 5 is operated by the hot water storage operation signal, the refrigerant is compressed by the compressor 1 to become high temperature and high pressure, dissipates heat by heating the water by the radiator 2, and becomes low temperature and low pressure by the decompression device 3. The heat exchanger 4 absorbs heat from the atmosphere and evaporates, and returns to the compressor 1. In the water circuit 9, the two-way valve 8 is opened, and city water supplied from the water supply pipe 10 to the hot water storage tank 6 is supplied from the lower part of the hot water storage tank 6 to the radiator 2 by the circulation pump 7 and heated by the radiator 2. The Hot water heated by the radiator 2 and heated to high temperature passes through the two-way valve 8 and flows into the upper part of the hot water storage tank 6 and is gradually stored from the upper part. When the temperature sensor 21 detects that the temperature of the water at the inlet of the radiator 2 has reached the set value, the temperature of the hot water stored in the hot water storage tank 6 has reached a predetermined temperature. The operation is stopped and the operation of the refrigerant circuit 5 is stopped. Normally, the hot water temperature supplied from the hot water supply terminal 15 is 45 ° C. or lower, but in the present invention, the heat storage amount in the hot water storage tank 6 is increased by setting the heating temperature of the water circuit 9 to 60 ° C. or higher in the hot water storage operation. Thus, by setting the heating temperature of the water circuit 9 to 60 ° C. or higher and setting the temperature of the hot water stored in the hot water storage tank 6 to be higher than the temperature of the hot water supplied from the hot water supply terminal 15, the capacity of the hot water storage tank 6 is increased. The hot water tank 6 can be reduced in size.
When supplying hot water to the hot water supply terminal 15, the hot water supply circuit 17 is opened in the hot water supply circuit 17, and the hot water in the hot water storage tank 6 is supplied by the pressure of city water flowing into the hot water storage tank 6 from the water supply pipe 10 below the hot water storage tank 6. It is made to flow out into the tapping pipe 11. Hot water flowing out of the hot water storage tank 6 passes through the first mixing valve 12 and is mixed with the low-temperature city water flowing from the city water pipe 13 by the second mixing valve 14. The second mixing valve 14 adjusts the mixing ratio of hot water and city water from the hot water storage tank 6 according to the output value of the hot water temperature sensor 24 and supplies hot water to the hot water supply terminal 15 as a predetermined temperature.
When hot water is supplied from the hot water supply terminal 15 at 45 ° C., the city water temperature varies depending on the season, and thus the heat pump hot water heater needs to be heated depending on the city water temperature and the outside air temperature. Especially in winter, the city water temperature is lowered and the outdoor temperature is lowered, so that the heating capacity of the heat pump water heater is lowered. Therefore, it is necessary to increase the amount of heat stored in the hot water tank 6 by increasing the heating temperature of the water circuit 9. Accordingly, the amount of heat stored in the hot water tank 6 is changed by changing the heating temperature of the water circuit 9 in the range of 60 ° C. to 90 ° C. in accordance with the outdoor air temperature and the city water temperature.

  Next, a hot water supply operation to the bath tub will be described. When hot water supply to the bath tub 16 is started by the bath tub hot water supply signal, the operation of the refrigerant circuit 5 is started, and the set heating temperature of the water circuit 9 is set to 35 ° C to 45 ° C. Thereby, since the compression ratio of the refrigerant circuit 5 can be reduced and the power consumption of the compressor 1 can be reduced, an efficient operation can be performed. Simultaneously with the hot water supply by the operation of the refrigerant circuit 5, the hot water in the hot water storage tank 6 is also supplied to the hot water supply circuit 17 through the first mixing valve 12, so that it is mixed with city water by the second mixing valve 14, and the predetermined temperature is reached. The amount of hot water (for example, 35 ° C. to 45 ° C.) supplied to the bath tub 16 can be maximized. As a result, hot water can be supplied to the bath tub 16 in a short time.

Next, a hot water supply operation when the amount of remaining hot water in the hot water tank 6 is reduced will be described. When the amount of remaining hot water in the hot water storage tank 6 is reduced by repeating the hot water supply and the output of the remaining hot water temperature sensor 23 falls below a predetermined value, a hot water storage operation signal is transmitted, the refrigerant circuit 5 is operated, and the output of the hot water temperature sensor 22 is output. The flow rate of the circulation pump 7 is controlled according to the value, hot water is supplied at the set heating temperature, and the hot water is stored in the hot water tank 6.
When the hot water supply terminal 15 is opened during the hot water storage operation in which the refrigerant circuit 5 is operated, the two-way valve 8 is closed, and the hot water heated by the radiator 2 passes through the first mixing valve 12 and passes through the second mixing valve 12. The mixed valve 14 is mixed with low-temperature city water flowing from the city water pipe 13. The second mixing valve 14 adjusts the mixing ratio of hot water and city water according to the output value of the hot water temperature sensor 24 and supplies hot water from the hot water supply terminal 15 as a predetermined temperature. In that case, when the use of hot water is large and the heating capacity is insufficient with only the refrigerant circuit 5, hot water is also supplied from the hot water storage tank 6 and mixed by the first mixing valve 12 to increase the amount of hot water supply. When the hot water supply terminal 15 is closed, the two-way valve 8 is opened and the first mixing valve 12 is closed to continue the hot water storage operation.

FIG. 2 shows an example of a hot water supply load pattern, assuming that the amount of hot water supply per day is 49320 kJ (11780 kcal) and 18 GJ (4.3 Gcal) per year (equivalent to the IBEC L mode).
FIG. 3 shows that the city water temperature in winter is 5 ° C., the capacity of the hot water storage tank 6 is 100 liters, the heating capacity Q at 45 ° C. is 10 kW, and the heating capacity Q at 65 ° C. is 8. It is the graph which calculated the remaining hot water amount change of the hot water storage tank 6 at the time of performing the above operation as 9 kW.
FIG. 4 is a graph showing a trial calculation of the capacity of the hot water tank 6 when the above operation is performed with a heating capacity Q at 45 ° C. of 5 kW, 10 kW, and 20 kW. In the IBEC L mode, the capacity of the hot water storage tank 6 is required to be 90 liters when the heating capacity is 10 kW and 50 liters when the capacity is 20 kW. Assuming that the amount of hot water supply per day is 73970 kJ (17670 kcal) and 27 GJ (6.45 Gcal) per year (equivalent to 1.5 times the IBEC L mode), the heating capacity of the hot water storage tank 6 is 160 liters at a heating capacity of 10 kW and 110 liters at 20 kW. Capacity is needed. In the L mode in which the hot water storage temperature is 85 ° C., the capacity of the hot water storage tank 6 can be reduced to 70 liters at a heating capacity of 10 kW and 32 liters at 20 kW.
Thus, since the capacity | capacitance of the hot water storage tank 6 can be estimated with the assumed hot water supply load and the heating capacity of the heat pump water heater, if the size of the hot water storage tank 6 is made larger than that capacity, the hot water will not run out.

According to the present embodiment, these operations eliminate the operation of the refrigerant circuit 5 when a small amount of hot water is supplied from the hot water supply terminal 15, and supply hot water to the bath tub 16 having a large amount of hot water supply and the remaining hot water in the hot water tank 6. Since the refrigerant circuit 5 is operated when the amount of water decreases, the number of operations / stops of the compressor 1 can be reduced, the reliability of the equipment can be increased, the size of the hot water tank 6 can be reduced, and the time can be reduced. Thus, the hot water supply to the bath tub 16 can be completed.
Further, as shown in FIG. 5, the two-way valve 8 is replaced with a three-way valve 19, and the three-way valve 19 is switched by the output of the hot water supply temperature sensor 22, so that the temperature of the water at the outlet of the radiator 2 can be increased. When the temperature is low, the water heated by the radiator 2 is returned to the lower part of the hot water tank 6 and the three-way valve 19 is switched when the temperature of the water heated by the radiator 2 approaches the set hot water temperature. If the hot water is returned to the upper part of the hot water tank 6, the temperature of the water in the hot water tank 6 can be kept high.

FIG. 6 is a configuration diagram of a heat pump water heater according to the second embodiment of the present invention. The same components as those in FIG.
In FIG. 6, the outlet pipe of the second mixing valve 14 is connected to the hot water supply terminal 15, and the branch pipe of the pipe connecting the first mixing valve 12 and the second mixing valve 14 and the branch pipe of the city water pipe 13 are connected. The outlet pipe of the third mixing valve 20 is connected to the bath tub 16 to constitute the hot water supply circuit 17. Reference numeral 25 is a bath hot water temperature sensor, and 26 is an outdoor air temperature sensor for detecting the outdoor air temperature.

  In the heat pump water heater configured as described above, during normal operation, the hot water supply terminal 15 is connected to the water circuit 9 via the second mixing valve 14, and the bath tub 16 is connected to the water circuit 9 via the third mixing valve 19, respectively. Since it is connected to the water pipe 13, when hot water is supplied to the hot water supply terminal 15 and the bath tub 16 at the same time, hot water can be supplied at different temperatures. Other hot water supply operation operations and actions are the same as those of the first embodiment described with reference to FIG.

Next, a hot water supply operation when the amount of remaining hot water in the hot water storage tank 6 is reduced will be described. The maximum heating capacity Q of the refrigerant circuit 5 varies depending on the outdoor temperature and the temperature of water supplied from the hot water tank 6 to the refrigerant circuit 5. Since the temperature of water changes with changes in the outside air temperature, the maximum heating capacity Q is considered to change with the outside air temperature. FIG. 7 shows the relationship of the maximum heating capacity Q to the outside air temperature when hot water is supplied at 45 ° C.
When the remaining amount of hot water in the hot water storage tank 6 is less than a predetermined value, such as when a large amount of hot water is supplied to the bath tub 16, the refrigerant circuit 5 depends on the output value of the temperature sensor 21 and the output value of the outdoor temperature sensor 26. Is calculated from the amount of hot water remaining in the hot water storage tank 6 and the maximum heating capacity Q of the refrigerant circuit 5, and the amount of hot water supplied from the hot water storage tank 6 is reduced to increase the heating in the refrigerant circuit 5. The supply capacity of the hot water from the water circuit 9 is increased by maximizing the capacity. Further, when the amount of remaining hot water in the hot water tank 6 decreases, the supply from the hot water tank 6 is stopped and hot water is supplied only from the water circuit 9.
For example, a case where hot water is stored in the hot water tank 6 at 80 ° C., the remaining hot water amount is 90 liters, the outdoor air temperature is 2 ° C., the city water temperature is 5 ° C., and the hot water of 180 liters is supplied to the bath tub 16 at 43 ° C. in 18 minutes. To do. At this time, the maximum heating capacity of the heat pump water heater at a heating temperature of 45 ° C. is 8 kW from FIG. Therefore, 2.87 liters of hot water at 45 ° C. can be supplied per minute.
However, when 180 liters of hot water is supplied to the bath tub 16 at 45 ° C. in 18 minutes, 10 liters of hot water is required per minute. The required hot water supply capacity at this time is 27.9 kW, and the heating capacity of only the refrigerant circuit 5 is insufficient for the hot water supply capacity of 19.9 kW. Accordingly, hot water of 80 ° C. is simultaneously supplied from the hot water storage tank 6 and mixed with city water of 5 ° C. by the second mixing valve 14 to supply hot water. The amount of hot water supplied from the hot water storage tank 6 at this time is 3.8 liters per minute, and 76 liters in 20 minutes. As a result, the remaining hot water amount in the hot water tank 6 is 24 liters.
At this time, the remaining hot water temperature sensor 23 detects the amount of remaining hot water in the hot water storage tank 6, and when the remaining hot water volume reaches 40 liters, the hot water supply amount from the hot water storage tank 6 is reduced to 2 liters per minute. The amount of hot water supplied to 6.6 liters per minute. Further, when the amount of remaining hot water in the hot water storage tank 6 becomes 30 liters, hot water supply from the hot water storage tank 6 is stopped and hot water supply is performed only from the refrigerant circuit 5. In that case, since the amount of hot water supply is 2.87 liters per minute, the time required to supply 180 liters of hot water to the bath tub 16 at 45 ° C. is 23.9 minutes. However, since the remaining hot water amount is 30 liters, hot water is supplied in the kitchen while hot water is supplied to the bath tub 16 (hot water supply amount 42 ° C, 15.9 liters, hot water tank 6 to 80 ° C, 7.9 liters hot water) Even if a shower is used immediately after the hot water supply to the bath tub 16 (the hot water supply amount is 42 ° C., 40 liters, the hot water storage tank 6 is 80 ° C., 19.5 liter hot water supply), a sufficient hot water supply amount can be secured.
By performing the above operation, even after a large amount of hot water is supplied to the bath tub 16, a certain amount of remaining hot water in the hot water tank 6 is secured, and immediately after the hot water is supplied to the bath tub 16, Even when hot water supply is required, not only can hot water run out, but also a sufficient hot water supply flow rate can be secured, and a small heat pump water heater that can sufficiently cope with hot water supply load can be provided.

  As described above, in this embodiment, the maximum heating capacity Q of the refrigerant circuit is calculated from the output value of the temperature sensor 21 and the output value of the outdoor temperature sensor 26, whereby the remaining hot water amount in the hot water storage tank 6 is more than a predetermined value. When the amount decreases, the amount of hot water supplied from the hot water tank 6 is decreased so that the ratio is calculated from the amount of hot water in the hot water tank 6 and the maximum heating capacity Q of the refrigerant circuit 5, and the hot water from the water circuit 9 is reduced. When the amount of remaining hot water in the hot water storage tank 6 is further reduced, the supply from the hot water storage tank 6 is stopped and hot water is supplied only from the water circuit 9, so that the hot water does not run out. It can cope with hot water supply load enough.

  As described above, since the heat pump water heater according to the present invention is small and can sufficiently cope with a hot water supply load, it can be installed in a narrow place, and is applicable not only to household use but also to industrial heat pump water heaters. it can.

The block diagram of the heat pump water heater in Example 1 of this invention Hot water supply load pattern of the heat pump water heater in Example 1 of the present invention The graph of the amount of remaining hot water of the heat pump water heater in Example 1 of this invention Graph of heating capacity and hot water storage tank capacity of heat pump water heater in Example 1 of the present invention The block diagram of the other heat pump water heater in Example 1 of this invention The block diagram of the heat pump water heater in Example 2 of this invention Performance graph of maximum heating capacity against outdoor temperature and city water temperature of heat pump water heater in Example 2 of the present invention Configuration diagram of conventional heat pump water heater

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Compressor 2 Radiator 3 Pressure reducing device 4 Air heat exchanger 5 Refrigerant circuit 6 Hot water tank 7 Circulation pump 8 Two-way valve 9 Water circuit 10 Water supply pipe 11 Hot water pipe 12 First mixing valve 13 City water pipe 14 Second Mixing valve 15 Hot water supply terminal 16 Bathtub 17 Hot water supply circuit 18 Water supply valve 19 Three-way valve 20 Third mixing valve 21 Temperature sensor 22 Hot water temperature sensor 23 Remaining hot water temperature sensor 24 Hot water temperature sensor 25 Bath hot water temperature sensor 26 Outside air temperature sensor 26

Claims (9)

  A refrigerant circuit in which a compressor, a radiator, a pressure reducing device, and an air heat exchanger are sequentially connected, a hot water storage tank, a circulation pump connected to a lower part of the hot water tank, the radiator, a two-way valve, and an upper part of the hot water tank. A water circuit sequentially connected, a lower part of the hot water tank is connected to a water supply pipe supplying city water, an upper part of the hot water tank is connected to a hot water outlet pipe, and the radiator and the two-way valve are connected to each other. A branch pipe of the pipe and the outlet pipe are connected to a first mixing valve, an outlet pipe of the first mixing valve and a city water pipe branched from the water supply pipe are connected to a second mixing valve, and the first 2. A heat pump water heater, wherein the outlet pipe of the mixing valve 2 is connected to at least one of a hot water supply terminal and a bath tub.   A temperature sensor that detects a temperature of water supplied to the radiator from a lower part of the hot water tank, a hot water temperature sensor that detects a temperature of hot water heated by the radiator, and a plurality of hot water amounts detected in the hot water tank. A hot water temperature sensor for detecting a hot water temperature sensor and a hot water temperature sensor for detecting a hot water temperature of the second mixing valve; operating the refrigerant circuit by a hot water signal; and supplying hot water heated by the radiator and hot water in the hot water storage tank Mixing with one mixing valve and supplying to the second mixing valve, and mixing the hot water from the first mixing valve and city water with the second mixing valve to adjust to a predetermined temperature; The heat pump water heater according to claim 1, wherein   A refrigerant circuit in which a compressor, a radiator, a pressure reducing device, and an air heat exchanger are sequentially connected; a hot water storage tank; a circulation pump connected to a lower part of the hot water tank; the radiator; a two-way valve; and an upper part of the hot water tank. A water circuit connected in sequence, a lower part of the hot water tank is connected to a water supply pipe for supplying city water, an upper part of the hot water tank is connected to a hot water outlet pipe, and the radiator and the two-way valve are connected to each other. A branch pipe of the pipe and the outlet pipe are connected to a first mixing valve, an outlet pipe of the first mixing valve and a city water pipe branched from the water supply pipe are connected to a second mixing valve, and the first The outlet pipe of the second mixing valve is connected to a hot water supply terminal, and the branch pipe of the pipe connecting the first mixing valve and the second mixing valve and the branch pipe of the city water pipe are connected to the third mixing valve. And the outlet pipe of the third mixing valve is connected to a bath tub. Heat pump water heater that.   A temperature sensor that detects a temperature of water supplied to the radiator from a lower part of the hot water tank, a hot water temperature sensor that detects a temperature of hot water heated by the radiator, and a plurality of hot water amounts detected in the hot water tank. A residual hot water temperature sensor, a hot water temperature sensor for detecting the hot water temperature of the second mixing valve, and a bath hot water temperature sensor for detecting the hot water temperature of the third mixing valve, and operating the refrigerant circuit by a hot water signal. The hot water heated by the radiator and the hot water in the hot water tank are mixed by the first mixing valve and supplied to the second mixing valve and the third mixing valve, and the second mixing valve and 4. The heat pump water heater according to claim 3, wherein the third mixing valve mixes hot water and city water from the first mixing valve to adjust to a predetermined temperature. 5.   When hot water supply is started from the hot water supply terminal, hot water is supplied only to the first mixing valve from the hot water storage tank, and when the remaining hot water amount in the hot water storage tank becomes a predetermined value or less, the refrigerant circuit is operated. The heat pump water heater according to claim 2 or 4, wherein hot water is stored in the hot water tank.   The refrigerant circuit is operated by a hot water supply signal to the bath tub so that the heating temperature of the water circuit is lower than the hot water temperature of the hot water tank, and the hot water of the hot water tank is supplied to the hot tub to supply hot water. 6. The heat pump water heater according to claim 5, wherein the amount is maximized.   The heat pump water heater according to claim 6, wherein when the hot water is supplied to the bath tub, the refrigerant circuit is operated to set the heating temperature of the water circuit to 35 ° C. to 45 ° C.   The heat pump water heater according to any one of claims 1 to 7, wherein the heating capacity Q of the refrigerant circuit and the capacity of the hot water storage tank are controlled to have a predetermined relationship. A temperature sensor for detecting the temperature of water supplied from the lower part of the hot water tank to the water circuit, an outdoor air temperature sensor for detecting outdoor air temperature, and a plurality of remaining hot water temperature sensors for detecting the amount of hot water in the hot water tank, When the heating capacity Q of the refrigerant circuit is calculated from the output value of the temperature sensor and the output value of the outdoor temperature sensor, and the remaining hot water amount of the hot water storage tank becomes smaller than a predetermined value, the remaining hot water amount of the hot water storage tank and the refrigerant When the supply amount of hot water from the hot water storage tank is decreased by the value calculated from the heating capacity Q of the circuit, the supply amount of hot water from the water circuit is increased, and the remaining hot water amount of the hot water storage tank is further reduced The heat pump water heater according to claim 1 or 3, wherein supply from the hot water tank is stopped and hot water is supplied only from the water circuit.

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