JP2013242115A - Storage type hot water supply system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a storage type hot water supply system capable of enhancing efficiency of a heat pump when the heat pump and an auxiliary heat source machine are operated together to supply hot water.SOLUTION: A storage type hot water supply system includes a second hot water storage control part 122 for performing second boiling operation which prohibits performance of first boiling operation by a first hot water storage control part 121 for heating water in a hot water storage tank 11 to a boiling temperature by a heat pump unit 50 when second hot water supply operation involving operation of a water heater 87 is performed, heats water at a lower part in the hot water storage tank by the heat pump unit 50 to a second boiling temperature lower than the first boiling temperature, and returns the water to an upper part of the hot water storage tank 11.

Description

  The present invention relates to a hot water storage device that heats hot water in a hot water storage tank by a heat pump, and a hot water storage hot water supply system that includes an auxiliary heat source device.

  Conventionally, when a hot water heater (auxiliary heat source) is connected to the downstream side of a hot water storage tank of a hot water storage device that heats the hot water in the hot water storage tank with a heat pump, the hot water temperature in the hot water storage tank drops during hot water supply. In addition, there is known a hot water storage type hot water supply system that operates an instantaneous heating type hot water heater to raise the temperature of hot water from a hot water storage tank (for example, see Patent Document 1).

  In the hot water storage type hot water supply system described in Patent Document 1, the water in the hot water storage tank is heated to a high temperature of about 70 to 90 ° C. to store hot water. Then, when the amount of hot water in the hot water storage tank becomes less than the predetermined amount (so-called hot water condition), the primary energy amount of the water heater and the primary energy amount of the heat pump that are required to obtain the same amount of heat for hot water supply are compared. When the primary energy amount when operating the heat pump is larger than the primary energy amount when operating the water heater, the operation of the heat pump is prohibited.

JP 2009-275958 A

  In the hot water storage type hot water supply system described in Patent Document 1, hot water is supplied by operating a heat pump or an auxiliary heat source alone when the hot water storage tank is out of hot water. Therefore, the efficiency of the heat pump in the case where hot water is supplied by operating both the heat pump and the auxiliary heat source device has not been studied.

  The present invention has been made in view of such a background, and an object of the present invention is to provide a hot water storage type hot water supply system capable of increasing the efficiency of a heat pump when hot water is supplied by operating both a heat pump and an auxiliary heat source machine. .

The present invention has been made to achieve the above object,
A hot water storage tank in which a water supply pipe is connected to the lower part and a hot water supply pipe is connected to the upper part to store water supplied from the water supply pipe,
A tank circulation path connecting a lower part and an upper part of the hot water storage tank, a tank circulation pump for circulating hot water stored in the lower part of the hot water storage tank to the upper part of the hot water storage tank via the tank circulation path, and the tank circulation pump A heat pump unit having a heat pump that heats hot and cold water circulating in the tank circulation path by operation of
The present invention relates to a hot water storage type hot water supply system provided with an auxiliary heat source device that is provided in the middle of the hot water supply pipe and heats hot water flowing through the hot water supply pipe.

And
A flowing water sensor for detecting flowing water in the water supply pipe or the hot water supply pipe;
When the hot water tank is detected to run out, the heat pump unit heats the hot water in the lower part of the hot water tank to a first boiling temperature not lower than the first hot water temperature and returns the hot water to the upper part of the hot water tank. A first hot water storage control unit for performing a boiling operation;
When flowing water is detected by the flowing water sensor, a first hot water supply operation for discharging hot water at a predetermined target hot water supply temperature from the hot water supply pipe without heating by the auxiliary heat source device, or heating by the auxiliary heat source device is performed. A hot water supply control unit for performing a second hot water supply operation for performing hot water discharge at the target hot water supply temperature from the hot water supply pipe;
When the second hot water supply operation is being executed, the first hot water storage controller prohibits execution of the first boiling operation, and the heat pump unit causes the hot water in the lower part of the hot water storage tank to be first boiled. And a second hot water storage control unit for performing a second boiling operation for heating to a second boiling temperature lower than the raised temperature and returning it to the upper part of the hot water storage tank (first invention).

  In the first invention, when the second hot water supply operation is being executed by the hot water supply control unit, the temperature of the hot water supplied from the hot water storage tank to the hot water supply pipe is lower than the target hot water supply temperature. The machine is operating. In this case, when the first boiling operation is executed by the first hot water storage control unit, the auxiliary heat source machine is activated while boiling the hot water in the hot water storage tank with the heat pump. However, the efficiency of the heat pump decreases as the boiling temperature increases.

  Therefore, when the second hot water supply operation is being executed, the second hot water storage control unit prohibits execution of the first boiling operation by the first hot water storage control unit, and executes the second hot water driving operation. To do. Thereby, the second hot water supply operation is performed in a state in which the primary energy efficiency of the heat pump is increased, with the boiling temperature by the heat pump being set as the second boiling temperature lower than the first boiling temperature. it can.

In the first invention,
The second hot water storage control unit has a predetermined temperature higher than the second boiling temperature in the hot water tank when the second boiling operation is started, regardless of whether or not the second hot water supply operation is subsequently performed. Until the amount of hot water above the low second hot water storage temperature becomes equal to or higher than a predetermined hot water storage amount, the first hot water control unit prohibits execution of the first hot water operation and performs the second hot water operation. It is characterized by continuing (second invention).

  According to the second invention, when the second hot water supply operation is intermittently performed, the first boiling operation and the second boiling operation are frequently switched, and the primary energy efficiency of the heat pump is reduced. Can be prevented.

In the first invention,
The hot water pipe is connected to the bathtub on the downstream side of the place where the auxiliary heat source device is provided,
With the predetermined hot water temperature set as the target hot water temperature, the hot water control unit executes the first hot water supply operation or the second hot water supply operation, whereby hot water at the hot water temperature is supplied to the bathtub by a predetermined hot water amount. A hot water filling control section for performing hot water filling operation for supplying only
A hot water filling instruction unit for instructing the start of the hot water filling operation,
In the second hot water storage control unit, when the start of the hot water filling operation is instructed by the hot water filling instructing unit, the heat storage amount of the hot water in the hot water storage tank is greater than or equal to the amount of heat necessary for executing the hot water filling operation. When the amount of stored hot water in the hot water storage tank is less than the amount of heat necessary for the hot water filling operation, the first hot water storage control unit prohibits the first boiling operation from being executed. Then, the second boiling operation is started (third invention).

  According to the third invention, when the second hot water storage control unit is instructed to start the hot water filling operation in accordance with an instruction from the hot water filling instruction unit, the heat storage amount of the hot water in the hot water storage tank is determined by the hot water storage tank. It is determined whether or not the amount of heat required for execution of the tension operation is smaller. When the heat storage amount of the hot water in the hot water storage tank is less than the heat amount required for performing the hot water filling operation, the second hot water storage control unit executes the first boiling operation by the first hot water storage control unit. And the second boiling operation is started.

  As described above, when the hot water filling operation cannot be executed only by the amount of hot water stored in the hot water storage tank, the second boiling operation is started from the start of the hot water filling operation. By doing so, the hot water filling operation can be executed while operating the heat pump more effectively and increasing the primary energy efficiency.

The block diagram of a hot water storage type hot-water supply system. The operation | movement flowchart of a controller. Explanatory drawing of the relationship between the efficiency of a heat pump, and the boiling temperature of the water in a hot water storage tank.

  An embodiment of the present invention will be described with reference to FIGS. With reference to FIG. 1, the hot water storage type hot water supply system of the present embodiment includes a hot water storage unit 10, a heat pump unit 50, a gas heat source unit 80, and a controller 120 that controls the overall operation of the hot water storage type hot water supply system. Has been.

  In FIG. 1, one controller 120 is shown as a controller for the hot water storage type hot water supply system. However, a controller for the hot water storage unit 10, a controller for the heat pump unit 50, and a controller for the gas heat source unit 80 are provided separately. It is good also as a structure which controls the whole action | operation of a hot water storage type hot-water supply system by communication of these.

  The hot water storage unit 10 includes a hot water storage tank 11, a water supply pipe 12, a hot water supply pipe 13, and the like. The hot water storage tank 11 retains hot water therein and stores tank temperature sensors 14 to 17 at substantially equal intervals in the height direction. A drain valve 18 is provided at the bottom of the hot water storage tank 11 and is opened by an operator's manual operation.

  One end of the water supply pipe 12 is connected to a water supply (not shown) through the water supply port 30, and the other end is connected to the lower part of the hot water storage tank 11 to supply water to the lower part of the hot water storage tank 11. The water supply pipe 12 is provided with a pressure reducing valve 19 for preventing the internal pressure of the hot water storage tank 11 from becoming excessive and a check valve 20 for preventing the hot water from flowing out of the hot water storage tank 11 into the water supply pipe 12. ing.

  The water supply pipe 12 communicates with the hot water supply pipe 13 via the tank mixing valve 21, and the hot water supplied from the hot water storage tank 11 to the hot water supply pipe 13 and the hot water supply pipe 12 are supplied to the hot water supply pipe by the tank mixing valve 21. The mixing ratio with water is changed. The water supply pipe 12 includes a water supply temperature sensor 22 that detects the temperature of the water supplied to the water supply pipe 12, a water flow rate sensor 23 that detects the flow rate of the water flowing through the water supply pipe 12, and the water supply pipe 13 to the water supply pipe 12. And a check valve 24 for preventing the outflow of hot and cold water.

  One end of the hot water supply pipe 13 is connected to the hot water supply port 31, and the other end is connected to the upper part of the hot water storage tank 11. Hot water stored in the upper part of the hot water storage tank 11 is supplied to a hot water tap (not shown) (kitchen, washroom, bathroom currant, shower, etc.) via a hot water outlet 31. A hot water pipe 13 circulates through the hot water pipe 13, a check valve 25 that prevents hot water from flowing into the hot water storage tank 11 from the hot water pipe 13, a hot water temperature sensor 26 that detects the temperature of hot water in the hot water pipe 13, and the hot water pipe 13. A hot water flow rate sensor 27 for detecting the flow rate of hot water is provided.

  The hot water supply pipe 13 branches to a bypass pipe 33 (bypass outlet pipe 33a and bypass return pipe 33b) connected to the gas heat source unit 80 on the downstream side of the connection portion of the water supply pipe 12 with the branch pipe. A hot water temperature sensor 28 is provided between the connection portion of the hot water supply pipe 13 with the bypass outlet pipe 33 a and the tank mixing valve 21, and between the connection portion of the hot water supply pipe 13 with the bypass return pipe 33 b and the hot water supply port 31, A mixed hot water temperature sensor 32 is provided.

  Further, a bypass control valve 29 for adjusting the flow rate of the hot water supplied to the bypass forward pipe 33a is provided between the connection part of the hot water supply pipe 13 to the bypass forward pipe 33a and the connection part of the bypass return pipe 33b. ing.

  Detection signals from the sensors provided in the hot water storage unit 10 are input to the controller 120. The operation of the tank mixing valve 21 and the bypass control valve 29 is controlled by a control signal output from the controller 120.

  Next, the heat pump unit 50 circulates the hot water in the hot water storage tank 11 through the tank circulation path 41 and heats it, and is installed outdoors. The heat pump unit 50 includes a heat pump 51 including an evaporator 53, a compressor 54, a heat pump heat exchanger 55 (condenser), and an expansion valve 56 connected by a heat pump circuit 52.

  The evaporator 53 exchanges heat between air (outside air) supplied by the rotation of the fan 60 and a heat medium (alternative chlorofluorocarbon (HFC) or other chlorofluorocarbon, carbon dioxide, etc.) flowing through the heat pump circuit 52. Do. The compressor 54 compresses the heat medium discharged from the evaporator 53 to high pressure and high temperature, and sends it to the heat pump heat exchanger 55. The expansion valve 56 releases the pressure of the heat medium pressurized by the compressor 54.

  The defrost valve 61 is provided so as to bypass the expansion valve 56, and defrosts the evaporator 53 with a heat medium sent from the compressor 54. Heat medium temperature sensors 62, 63 for detecting the temperature of the heat medium circulating in the heat pump circuit 52 are provided upstream and downstream of the expansion valve 56 of the heat pump circuit 52 and upstream and downstream of the compressor 54. 64 and 65 are provided, respectively. The evaporator 53 is provided with an ambient temperature sensor 67 that detects the temperature of air sucked into the evaporator 53.

  The heat pump heat exchanger 55 is connected to the tank circulation path 41, and circulates in the tank circulation path 41 by heat exchange between the heat medium that has been increased in pressure and temperature by the compressor 54 and hot water flowing in the tank circulation path 41. Heat the hot water. The tank circulation path 41 is provided with a tank circulation pump 66 for circulating hot water in the hot water storage tank 11 through the tank circulation path 41.

  Hot water stored in the lower part of the hot water storage tank 11 is guided to the tank circulation path 41 by the tank circulation pump 66, heated to the target boiling temperature by the heat pump heat exchanger 55, and returned to the upper part of the hot water storage tank 11. As a result, hot water at the target boiling temperature is sequentially stacked from the upper part of the hot water storage tank 11 and stored.

  Note that hot water temperature sensors 68 and 69 for detecting the temperature of hot water flowing in the tank circulation path 41 are provided on the upstream side and the downstream side of the heat pump heat exchanger 55 in the tank circulation path 41. The heat pump heat exchanger 55 is provided with an ambient temperature sensor 57 that detects the ambient temperature inside the heat pump heat exchanger 55.

  Detection signals from the sensors provided in the heat pump unit 50 are input to the controller 120. The operation of the compressor 54, the tank circulation pump 66, and the fan 60 is controlled by a control signal output from the controller 120.

  Next, the gas heat source unit 80 heats hot water supplied to the bypass pipe 33 and hot water flowing in the bath circulation path 102 connected to the bathtub 101, and includes a hot water supply burner 81 and a hot water supply heat exchanger 82. A reheating burner 83, a reheating heat exchanger 84, a water supply pipe 85, a hot water supply pipe 86, and the like are provided. The water supply pipe 85, the hot water supply pipe 86, and the water passage of the hot water supply heat exchanger 82 constitute a hot water supply pipe of the present invention connected to the hot water storage tank 11.

  Fuel gas is supplied from a gas supply pipe (not shown) to the hot water supply burner 81 and the reheating burner 83, and combustion air is supplied from a combustion fan (not shown). The controller 120 controls the combustion amount of the hot water supply burner 81 and the additional burner 83 by adjusting the flow rates of the fuel gas and the combustion air supplied to the hot water supply burner 81 and the additional burner 83.

  The hot water supply heat exchanger 82 communicates with the water supply pipe 85 and the hot water supply pipe 86, and heats the water supplied from the water supply pipe 85 by the combustion heat of the hot water supply burner 81 and discharges the hot water to the hot water supply pipe 86. One end of the water supply pipe 85 is connected to the bypass forward pipe 33a of the hot water storage unit 10, and hot water is supplied through the bypass forward pipe 33a. One end of the hot water supply pipe 86 is connected to the bypass return pipe 33b of the hot water storage unit 10, and supplies hot water from the hot water supply port 31 via the bypass return pipe 33b.

  The water supply pipe 85 is provided with a water stop valve 93 and a water amount sensor 88 (corresponding to the water flow sensor of the present invention) in order from the upstream side. The water supply pipe 85 and the hot water supply pipe 86 communicate with each other by a bypass pipe 89, and the bypass pipe 89 is provided with a water amount adjustment valve 90 for adjusting the opening degree of the bypass pipe 89. Hot water supply temperature sensors 91 and 92 for detecting the temperature of hot water flowing through the hot water supply pipe 86 are provided on the downstream side of the hot water supply heat exchanger 82 of the hot water supply pipe 86 and the downstream side of the connection portion with the bypass pipe 89, respectively. It has been.

  With this configuration, when there is no hot water in the hot water storage tank 11 (running out of hot water), the water supplied to the water supply pipe 85 via the bypass forward pipe 33a is heated by the hot water supply heat exchanger 82 to become hot water, and the bypass pipe It is mixed with water from 89 and supplied from the hot water supply port 31 through the hot water supply pipe 86 and the bypass return pipe 33b.

  In addition, a hot water supply heat exchanger 82 connected to the water supply pipe 85 and the hot water supply pipe 86 and a hot water supply burner 81 for heating the hot water supply heat exchanger 82 are provided, and the hot water supply pipe is supplied from the water supply pipe 85 through the hot water supply heat exchanger 82. The configuration for heating the hot water flowing through 86 corresponds to the auxiliary heat source device of the present invention, and is shown as a hot water heater 87 in FIG. The hot water heater 87 is provided in the middle of the hot water supply path of the present invention including the water supply pipe 85, the hot water supply pipe 86 and the water supply heat exchanger 82.

  The hot water supply pipe 86 communicates with the bath circulation path 102 connected to the bathtub 101 through the hot water filled pipe 100. The hot water filling pipe 100 is provided with a hot water filling valve 103 that opens and closes the hot water filling pipe 100 and a hot water filling flow rate sensor 104 that detects the flow rate of hot water flowing through the hot water filling pipe 100.

  The controller 120 opens the hot water filling valve 103, thereby supplying hot water from the hot water supply pipe 86 to the bathtub 101 through the hot water filling pipe 100 and the bath circulation path 102, and the bathtub 101 according to the detected flow rate of the hot water filling flow rate sensor 104. The hot water filling operation for supplying the target hot water amount to the bathtub 101 is performed by accumulating the hot water supply amount to the bathtub 101.

  The bath circulation path 102 includes a bath forward pipe 102a and a bath return pipe 102b in which the bathtub 101 and the reheating heat exchanger 84 are connected. The bath return pipe 102b is circulated in the bath return pipe 102b, a bath circulation pump 105 that circulates hot water in the bathtub 101 through the bath circulation path 102, a water flow switch 108 that detects the water flow in the bath circulation path 102, and the bath return pipe 102b. There is provided a bath return temperature sensor 107 for detecting the temperature of the hot water. Further, the bath-out pipe 102a is provided with a bath-out temperature sensor 106 that detects the temperature of hot water flowing through the bath-out pipe 102a.

  The controller 120 operates the bath circulation pump 105 to heat the hot water in the bathtub 101 by burning the reheating burner 83 in a state where the hot water in the bathtub 101 is circulated through the bath circulation path 102. Execute “retreat operation”.

  Each sensor provided in the gas heat source unit 80 and detection signals of the water flow switch 108 are input to the controller 120. In addition, the operation of the hot water supply burner 81, the reheating burner 83, the water amount adjustment valve 90, the water stop valve 93, the hot water filling valve 103, and the bath circulation pump 105 is controlled by the control signal output from the controller 120.

  The controller 120 is an electronic circuit unit configured by a CPU, a memory, and the like (not shown). By executing a control program for the hot water storage hot water system held in the memory by the CPU, the first hot water storage controller 121, 2 Functions as a hot water storage control unit 122, a hot water supply control unit 123, a hot water filling control unit 124, and a reheating control unit 125.

  The controller 120 is connected to the remote controller 140 via a communication cable 130. The remote controller 140 includes a display 141 for displaying the operating status of the hot water storage hot water supply system, setting of operating conditions, and the like, and a switch unit 142 provided with various switches.

  The user of the hot water storage hot water supply system operates the remote controller 140 to indicate the boiling temperature of the hot water in the hot water storage tank 11 (corresponding to the first boiling temperature of the present invention), the hot water supply temperature from the hot water supply port 31. A (target hot water supply temperature) setting, a hot water supply temperature (target hot water filling temperature) setting to the bathtub 101, a "hot water filling operation" execution instruction, a "reheating operation" execution instruction, and the like can be performed. The hot water filling switch provided in the switch unit 142 for instructing execution of the “hot water filling operation” corresponds to the hot water filling instruction portion of the present invention.

  The first hot water storage control unit 121 detects the hot water out of the hot water storage tank 11 based on the temperature detected by the tank temperature sensors 14 to 17, and when the hot water has run out, operates the heat pump unit 50 to supply hot water in the hot water storage tank 11. Heat to the target boiling temperature. For example, when the target boiling temperature is set to 45 ° C. by the remote controller 140, the temperature detected by the tank temperature sensor 17 at the upper part of the hot water storage tank 11 is 40 ° C. (target boiling temperature −5 ° C., the first of the present invention). The first hot water storage control unit 121 determines that the hot water storage tank 11 is out of hot water.

  It should be noted that the detection of running out of hot water in the hot water storage tank 11 is performed by (1) the hot water heater 87 of the gas heat source unit 80 being operated, and (2) the temperature detected by the tank temperature sensors 14-17 of the hot water storage tank 11 is higher than the target hot water temperature. It may be performed by determining that the temperature has been lowered, (3) the temperature detected by the hot water temperature sensor 26 from the hot water storage tank 11 is lower than the set temperature, and the like.

  The amount of hot water from the upper part of the hot water storage tank 11 to the mounting position of the tank temperature sensor 17 corresponds to the lower limit hot water storage amount of the present invention. Further, when the temperature detected by the tank temperature sensor 17 at the upper part of the hot water storage tank 11 becomes 40 ° C. (first hot water storage temperature) or lower, the remaining amount of hot water below the first hot water storage temperature in the hot water storage tank 11 is the lower limit hot water storage amount. It is as follows.

  The first hot water storage control unit 121 operates the heat pump unit 50 to heat the water below the hot water storage tank 11 to 45 ° C. with the heat pump heat exchanger 55 when the hot water storage tank 11 has run out. By returning to the upper part of the hot water storage tank 11, a “first boiling operation” is performed in which hot water of the target boiling temperature (first boiling temperature) is stacked from the upper part of the hot water storage tank 11.

  During the execution of the “first boiling operation”, the first hot water storage control unit 121 detects the hot water stacking state at the target boiling temperature in the hot water storage tank 11 based on the detected temperatures of the tank temperature sensors 14 to 17, and stores hot water. When the tank 11 is filled with hot water at the target boiling temperature, the “first boiling operation” is terminated.

  In the case described later, the second hot water storage control unit 122 prohibits the execution of the “first boiling operation” by the first hot water storage control unit 121, operates the heat pump unit 50, and heats the water below the hot water storage tank 11 to the heat pump. In the heat exchanger 55, a “second boiling operation” is performed in which the temperature is lower than the target boiling temperature (corresponding to the second boiling temperature of the present invention) and returned to the upper part of the hot water storage tank 11.

  The hot water supply control unit 123 detects that the hot water tap (not shown) connected via the hot water supply port 31 is opened and that the hot water of a predetermined minimum flow rate is flowing in the water supply pipe 85 by the water amount sensor 88. When running (when flowing water in the water supply pipe 85 is detected), a "hot water supply operation" is performed in which hot water at the target hot water supply temperature 31 (hot water temperature set by the remote controller 140) is supplied from the hot water supply port 31.

  When the temperature of the hot water stored in the hot water storage tank 11 is equal to or higher than the target hot water temperature, the hot water supply control unit 123 supplies hot water at the target hot water temperature without operating the water heater 87 by operating the tank mixing valve 21 or the like. A first hot water supply operation for discharging hot water from the mouth 31 is performed. When the temperature of the hot water stored in the hot water storage tank 11 is lower than the target hot water supply temperature, the second hot water supply operation of operating the hot water heater 87 and discharging hot water at the target hot water supply temperature 31 from the hot water supply port 31 is executed.

  The chasing control unit 125 performs the above-described “chasing operation” to heat the hot water in the bathtub 101 when the chasing switch provided in the switch unit 142 of the remote controller 140 is operated.

  When the hot water filling switch provided in the switch unit 142 of the remote controller 140 is operated, the hot water filling control unit 124 performs the above-described “hot water filling operation” to supply hot water at the target hot water temperature to the bathtub 101. Supply only the amount of tension. In the “hot water operation”, the hot water supply control unit 123 performs the “hot water operation” by setting the target hot water temperature as the target hot water temperature.

  Next, according to the flowchart shown in FIG. 2, execution processing of “first boiling operation” and “second boiling operation” when the controller 120 executes “hot water filling operation” and “second hot water supply operation” will be described. .

  In STEP 1, the controller 120 determines whether or not a hot water switch provided in the switch unit 142 of the remote controller 140 has been operated. Then, when the hot water filling switch is operated, the process proceeds to STEP2, and when the hot water filling switch is not operated, the process branches to STEP10. Here, when the hot water filling switch is operated, the hot water filling control unit 124 starts the “hot water filling operation”.

  STEP 2 to STEP 6 are processes by the second hot water storage control unit 122. In STEP 2, the second hot water storage control unit 122 determines whether or not the heat storage amount of the hot water stored in the hot water storage tank 11 is less than the heat amount required for hot water filling at the target hot water temperature.

  The hot water storage amount in the hot water storage tank 11 is equal to or greater than the amount of heat necessary for hot water filling at the target hot water filling temperature, and the hot water filling operation at the target hot water filling temperature is performed only by the hot water stored in the hot water storage tank 11. Branches to STEP10 when possible.

  On the other hand, the heat storage amount of the hot water stored in the hot water storage tank 11 is less than the heat amount required for the hot water filling operation at the target hot water temperature, and the hot water filling at the target hot water temperature is caused only by the hot water stored in the hot water storage tank 11. If impossible, go to STEP3. In this case, the hot water storage tank 11 runs out during execution of the “hot water operation”, so the “second hot water operation” for operating the water heater 87 is executed.

  Thus, when it is assumed that the “second hot water supply operation” is executed, the heat pump unit 50 is operated from the time when the “hot water filling operation” is started, so that the efficiency is higher than that of the hot water heater 87. The energy consumption in the hot water heater 87 can be reduced by actively using the high heat pump 51.

  Here, in FIG. 3, the vertical axis is set to the efficiency (%) of the heat pump 51, the horizontal axis is set to the boiling temperature (° C.) by the heat pump 51, and the feed water temperature Tw is 5 ° C. (c1 in the figure). ) And 25 [deg.] C. (c2 in the figure), the relationship between the efficiency of the heat pump 51 and the boiling temperature is shown. FIG. 3 shows a case where the ambient temperature (= outside temperature) Tout of the heat pump 51 is 5 ° C.

  3 that the efficiency of the heat pump 51 increases as the boiling temperature by the heat pump 51 decreases. Accordingly, the second hot water storage control unit 122 prohibits the execution of the “first boiling operation” by the first hot water storage control unit 121 in STEP 3 and executes the “second boiling operation” in STEP 4.

  In the “second boiling operation”, the second hot water storage control unit 122 sets the boiling temperature to a second boiling temperature that is lower than the target boiling temperature (45 ° C.), and the heat pump unit 50 performs the hot water storage tank 11. Heat the hot water inside. As a result, the “hot water operation” can be performed while operating the heat pump 51 in a highly efficient state.

  For example, when the heating capacity of the heat pump 51 is 5.5 kW, the temperature of water supplied from the water supply pipe 12 to the hot water storage tank 11 is 5 ° C., and the maximum flow rate of the tank circulation pump 66 is 4 liters / min, the second hot water storage The control unit 122 operates the heat pump 51 and the tank circulation pump 66 with the maximum capacity. In this case, the boiling temperature by the heat pump 51 (temperature of the tapping water from the heat pump heat exchanger 55) is 24.7 ° C. (<45 ° C.), and the efficiency of the heat pump 51 is about 700%.

  In subsequent STEP 5, the second hot water storage control unit 122 determines whether or not the “hot water filling operation” by the hot water filling control unit 124 has ended. When the “hot water filling operation” has not ended, the process returns to STEP 4 and the “second boiling-up operation” is continued. Further, when the “hot water filling operation” is completed, the process proceeds to STEP 6, and the second hot water storage control unit 122 ends the “second boiling operation”. In the next STEP 7, the second hot water storage control unit 122 cancels the prohibition of the “first boiling operation” and returns to STEP 1.

  In STEP 10, the second hot water storage control unit 122 determines whether the “second hot water supply operation” is being executed. When the “second hot water supply operation” is being executed (when the water flow sensor 88 detects a water flow that is equal to or higher than the lower limit flow rate and the hot water heater 87 is operating), the process proceeds to STEP 11 and “second hot water supply” is performed. When “operation” is not being executed, the process branches to STEP20.

  In STEP 11, the second hot water storage control unit 122 determines whether the detected temperature of the tank temperature sensor 16 of the hot water storage tank 11 is equal to or higher than the first boiling temperature −5 ° C. (corresponding to the second hot water storage temperature of the present invention). To do. The hot water storage amount from the upper part of the hot water storage tank 11 to the water level corresponding to the tank temperature sensor 16 corresponds to the reserved hot water amount of the present invention.

  When the temperature detected by the tank temperature sensor 16 is lower than the second boiling temperature −5 ° C. and the amount of stored hot water in the hot water storage tank 11 is small (the amount of hot water equal to or higher than the second hot water storage temperature is secured for hot water storage). If it is less than the amount), go to STEP12.

  In STEP 12, the second hot water storage control unit 122 prohibits the “first boiling operation”, executes the “second boiling operation” in subsequent STEP 13, and returns to STEP 1. In this way, when the “second hot water supply operation” is being performed and the water heater 87 is operating, the “second boiling” is set at the second boiling temperature lower than the target boiling temperature. By performing “operation”, the efficiency of the heat pump 51 can be increased.

  On the other hand, when the detected temperature of the tank temperature sensor 16 is equal to or higher than the second boiling temperature −5 ° C. in STEP 11 and a certain amount of hot water is stored in the hot water storage tank 11 (the second temperature in the hot water storage tank 11 is 2nd). When the amount of hot water above the hot water storage temperature is equal to or higher than the reserved hot water amount), the process branches to STEP20. In STEP 20, the second hot water storage control unit 122 ends the “second boiling operation”, and then cancels the prohibition of the “first boiling operation” in STEP 21.

  In this case, when the temperature detected by the tank temperature sensor 16 is equal to or higher than the second boiling temperature and a certain amount of hot water is stored in the hot water storage tank 11, the “second hot water supply operation” is being executed. The “second boiling-up operation” is not executed.

  Therefore, when the user intermittently uses hot water while the hot water storage tank 11 is out of hot water, the “second boiling operation” is executed during hot water supply, and the “first boiling operation” is performed while hot water is stopped. ”Is executed, the boiling temperature by the heat pump 51 is frequently switched between the second boiling temperature and the first boiling temperature, and the efficiency of the heat pump 51 can be prevented from decreasing.

  In the present embodiment, a hot water storage type hot water supply system having a function of performing “hot water filling operation” is shown. However, the effect of the present invention is also applied to a hot water storage type hot water supply system having no function of performing “hot water filling operation”. Can be obtained.

  Further, in this embodiment, in STEP 11 of FIG. 2, it is determined that the “first boiling operation” and the “second boiling operation” are frequently switched by determining the remaining amount of hot water in the hot water storage tank 11. Although the processing to avoid was performed, the effect of the present invention can be obtained even when this processing is not performed.

  In this case, when the second hot water supply operation is being executed in STEP 10, the hot water storage tank 11 is in a hot water condition, and the hot water in the hot water storage tank 11 cannot be heated to the target hot water supply temperature only by heating with the heat pump 51. It is in a situation. Therefore, the second hot water supply is performed in a state where the primary energy efficiency by the heat pump 51 is increased by prohibiting the first boiling operation in STEP 12 and executing the second boiling operation in STEP 13 without making the determination in STEP 11. Driving can be performed.

  Moreover, in this embodiment, although the hot water heater 87 which uses gas as a fuel was shown as an auxiliary heat source apparatus of this invention, other types of auxiliary heat source apparatuses, such as a water heater using other fuels, such as petroleum, and an electric heater, are shown. It may be used.

  DESCRIPTION OF SYMBOLS 10 ... Hot water storage unit, 11 ... Hot water storage tank, 12 ... Water supply pipe, 13 ... Hot water supply pipe, 22 ... Water supply temperature sensor, 67 ... Ambient temperature sensor, 50 ... Heat pump unit, 51 ... Heat pump, 80 ... Gas heat source machine unit, 87 ... Hot water heater, 100 ... hot water filling pipe, 120 ... controller, 121 ... first hot water storage control unit, 122 ... second hot water storage control unit, 123 ... hot water supply control unit, 124 ... hot water filling control unit, 125 ... reheating control unit.

Claims (3)

A hot water storage tank in which a water supply pipe is connected to the lower part and a hot water supply pipe is connected to the upper part to store water supplied from the water supply pipe,
A tank circulation path connecting a lower part and an upper part of the hot water storage tank, a tank circulation pump for circulating hot water stored in the lower part of the hot water storage tank to the upper part of the hot water storage tank via the tank circulation path, and the tank circulation pump A heat pump unit having a heat pump that heats hot and cold water circulating in the tank circulation path by operation of
In the hot water storage hot water supply system provided with an auxiliary heat source device that is provided in the middle of the hot water supply pipe and heats hot water flowing through the hot water supply pipe,
A flowing water sensor for detecting flowing water in the water supply pipe or the hot water supply pipe;
When the hot water tank is detected to run out, the heat pump unit heats the hot water in the lower part of the hot water tank to a first boiling temperature not lower than the first hot water temperature and returns the hot water to the upper part of the hot water tank. A first hot water storage control unit for performing a boiling operation;
When flowing water is detected by the flowing water sensor, a first hot water supply operation for discharging hot water at a predetermined target hot water supply temperature from the hot water supply pipe without heating by the auxiliary heat source device, or heating by the auxiliary heat source device is performed. A hot water supply control unit for performing a second hot water supply operation for performing hot water discharge at the target hot water supply temperature from the hot water supply pipe;
When the second hot water supply operation is being executed, the first hot water storage controller prohibits execution of the first boiling operation, and the heat pump unit causes the hot water in the lower part of the hot water storage tank to be first boiled. A hot water storage type hot water supply system comprising: a second hot water storage control unit for performing a second boiling up operation for heating to a second boiling temperature lower than the raised temperature and returning the heated water to the upper part of the hot water storage tank. In the hot water storage type hot water supply system according to claim 1,
When the second hot water storage control unit starts the second boiling operation, the amount of hot water equal to or higher than the second hot water temperature lower than the first boiling temperature in the hot water tank is a predetermined hot water storage temperature. Until the amount exceeds the secured amount, regardless of whether or not the second hot water supply operation is subsequently performed, the first hot water storage control unit is prohibited from performing the first boiling operation, and the second boiling water operation is performed. Hot water storage hot water supply system that is characterized by continuing. In the hot water storage type hot water supply system according to claim 1,
The hot water pipe is connected to the bathtub on the downstream side of the place where the auxiliary heat source device is provided,
With the predetermined hot water temperature set as the target hot water temperature, the hot water control unit executes the first hot water supply operation or the second hot water supply operation, whereby hot water at the hot water temperature is supplied to the bathtub by a predetermined hot water amount. A hot water filling control section for performing hot water filling operation for supplying only
A hot water filling instruction unit for instructing the start of the hot water filling operation,
In the second hot water storage control unit, when the start of the hot water filling operation is instructed by the hot water filling instructing unit, the heat storage amount of the hot water in the hot water storage tank is greater than or equal to the amount of heat necessary for executing the hot water filling operation. When the amount of stored hot water in the hot water storage tank is less than the amount of heat necessary for the hot water filling operation, the first hot water storage control unit prohibits the first boiling operation from being executed. The hot water storage type hot water supply system is characterized in that the second boiling operation is started.