JP5188378B2 - Heat pump water heater - Google Patents

Description

  The present invention relates to a heat pump water heater that stores hot water boiled using a heat pump unit as a heat source device in a hot water storage tank and supplies the hot water to a desired hot water supply destination.

  In a hot water supply machine that stores hot water boiled by a heat source machine in a hot water storage tank and supplies hot water to a desired hot water supply destination, a heat pump unit that is more efficient than a heater instead of using a heater as a heat source machine in recent years A heat pump water heater of a type in which the hot water storage tank is made small so that it can be installed in a narrow space is also being sold. However, if the hot water storage tank is made smaller, the amount of hot water that can be stored in the hot water storage tank is inevitably reduced, so that the danger of “hot water shortage” that runs out of hot water during hot water supply increases.

  In order to prevent the above-mentioned “running out of hot water”, for example, in the heat pump water heater described in Patent Document 1, the heat pump unit boils the hot water mixing valve in the hot water supply pipe that supplies hot water in the hot water storage tank to the hot water supply destination. The raised hot water can flow directly according to the situation. Specifically, the first pipe for supplying hot water boiled by the heat pump unit to the hot water storage tank, the second pipe for supplying hot water in the hot water storage tank to the hot water mixing valve, and water such as city water are used as described above. An electric switching valve is provided in each of the third pipes supplied to the hot water mixing valve, and an electric switching valve provided in the first pipe and an electric switching valve provided in each of the second and third pipes are piped. The hot water flowing through the first pipe is allowed to flow directly to the hot water mixing valve by appropriately switching the flow paths by the electric switching valves.

JP 2001-280695 A

  In the heat pump water heater described in Patent Document 1, three electric switching valves are used to prevent “running out of hot water”, so that the number of parts increases and it is difficult to suppress the manufacturing cost. In addition, since many motor-operated valves are controlled according to the situation, the control method becomes complicated.

  The present invention has been made in view of the above circumstances, and an object of the present invention is to obtain a heat pump water heater that can secure a high hot water supply capacity under simple control even when the hot water storage tank is small and that can easily suppress the manufacturing cost. And

  The heat pump water heater of the present invention includes a hot water storage tank for storing water supplied from a water supply pipe, a first heat exchanger for boiling water passed from the hot water storage tank into hot water, and a first heat exchanger. The hot water boiled in is supplied to the hot water storage tank, the mixing valve that mixes the hot water passed from the hot water storage tank and the water passed from the water supply pipe, and the mixed valve passes the water. A second heat exchanger for heating the hot water, a hot water supply pipe for supplying hot water heated by the second heat exchanger to the hot water supply destination, a temperature sensor for detecting the temperature of the hot water in the hot water supply pipe, Hot water supply that operates the second heat exchanger at the time of hot water supply to the hot water supply destination and controls the mixing ratio of hot water at the mixing valve using the detection result of the temperature sensor to adjust the hot water supply temperature to the hot water supply destination And a temperature controller.

  The heat pump water heater of the present invention mixes the hot water passed from the hot water storage tank to the mixing valve and the water passed from the water supply pipe to the mixing valve, and then passes the water to the second heat exchanger. In addition, since the hot water can be supplied to the hot water supply destination after being heated by the second heat exchanger, the hot water in the hot water storage tank is not consumed so much, and the electric switching valve other than the mixing valve is not used. Hot water of temperature can be supplied to the hot water supply destination. Therefore, according to the present invention, even if the hot water storage tank is small, it is possible to obtain a heat pump water heater that can secure high hot water supply capacity under simple control and can easily reduce the manufacturing cost.

  Hereinafter, embodiments of the heat pump water heater of the present invention will be described in detail with reference to the drawings. The present invention is not limited to the embodiments described below.

  FIG. 1 is a schematic view showing an example of a heat pump water heater of the present invention. The heat pump water heater 130 shown in the figure is for boiling water into hot water and supplying it to a predetermined hot water supply destination, and includes a heat pump unit 20, a tank unit 110, and a remote controller 120. Hereinafter, each component of the heat pump water heater 130 will be described.

  The heat pump unit 20 includes a compressor 1 that compresses a refrigerant such as carbon dioxide, a heat exchanger 3 that corresponds to a radiator, an expansion valve 5, an evaporator 7, and a circulation pipe 9 that connects these in an annular shape. And a heat pump side control device 15 that controls the operation of the refrigeration cycle unit 10 and functions as a heat source machine. In the refrigeration cycle unit 10, a refrigerant such as carbon dioxide is compressed by the compressor 1 to become a high temperature and a high pressure, and then radiates heat by the heat exchanger 3, is decompressed by the expansion valve 5, and absorbs heat by the evaporator 7. It becomes a gas state and is sucked into the compressor 1. The heat exchanger 3 can be divided into a first heat exchanger 3a to which a later-described boiling circulation line 50 is connected and a second heat exchanger 3b to which a later-described hot water supply line 80 is connected. is there. In addition, the heat pump side control apparatus 15 is controlled by the tank side control apparatus 100 mentioned later.

  On the other hand, the tank unit 110 includes a hot water storage tank 30, a water supply line 40, a boiling circulation line 50, a mixing line 60, a mixing valve 70, a hot water supply line 80, a flow switch 83, a temperature sensor 85, and a tank side. A control device 100 and the like are included.

  The hot water storage tank 30 stores water supplied from the water supply pipe 40 and hot water boiled by the first heat exchanger 3a. The lower part of the hot water storage tank 30 is connected to a feed water pipe 40 and an outgoing pipe 50a of a boiling circulation pipe 50, and the upper part is connected to a return pipe 50b of the boiling circulation pipe 50 and a mixing pipe 60. The The hot water storage tank 30 is always kept in a full state by supplying water from the water supply pipe 40, and the water supply pressure is always applied to the hot water in the hot water storage tank 30 from the water supply pipe 40. A plurality of temperature sensors (not shown) having different mounting heights are installed on the outer surface of the hot water storage tank 30, and each temperature sensor sends the detection result to the tank-side control device 100.

  The water supply pipe 40 is a pipe that supplies water such as city water to the hot water storage tank 30 and the mixing valve 70, and includes a first water supply pipe section 40a and a second water supply pipe section 40b. The first water supply pipe section 40 a connects the water source and the lower part of the hot water storage tank 30, and the second water supply pipe section 40 b branches from the first water supply pipe section 40 a and connects the first water supply pipe section 40 a and the mixing valve 70. A pressure reducing valve (not shown) is provided upstream of the branch point of the second water supply pipe part 40b from the first water supply pipe part 40a, and the water flows through the first water supply pipe part 40a and the second water supply pipe part 40b. The water pressure is reduced to a predetermined value. Moreover, the 2nd water supply pipe part 40b is provided with the temperature sensor (not shown) which detects the temperature of the water in this 2nd water supply pipe part 40b. The flow direction of water in the water supply line 40 is indicated by a solid arrow A in FIG.

  The boiling circulation pipe 50 is a pipe that reaches the upper part of the hot water storage tank 30 from the lower part of the hot water storage tank 30 via the first heat exchanger 3a, and has an outward pipe 50a and a return pipe 50b. . The forward pipe 50a connects the lower part of the hot water storage tank 30 and the first heat exchanger 3a, and the return pipe 50b connects the first heat exchanger 3a and the upper part of the hot water storage tank 30. A circulation pump 55 whose operation is controlled by the tank-side control device 100 is provided in the forward pipe 50a. By starting up the heat pump unit 20 and the circulation pump 55, the water in the lower part of the hot water storage tank 30 flows into the forward pipe 50a and is boiled up into hot water by heat exchange in the first heat exchanger 3a, and then returns. It returns to the upper part of the hot water storage tank 30 through the pipe 50b. The return pipe 50b functions as a hot water storage pipe that supplies the hot water boiled by the first heat exchanger 3a to the hot water storage tank 30. The flowing direction of hot water in the boiling circulation pipe 50 is indicated by a solid arrow B in FIG.

  The mixing conduit 60 is a conduit for passing hot water stored in the hot water storage tank 30 to the mixing valve 70, and connects the upper portion of the hot water storage tank 30 and the mixing valve 70. The flowing direction of hot water in the mixing pipe 60 is indicated by a solid arrow C in FIG.

  The mixing valve 70 is connected to the mixing pipe 60 and the second water supply pipe 40b. Operation of the mixing valve 70 is controlled by the tank-side control device 100, and the hot water passed from the hot water storage tank 30 through the mixing conduit 60 and the water passed from the second water supply pipe portion 40b are predetermined. The mixture is mixed at a rate of

  The hot water supply pipe 80 is a pipe that reaches the hot water supply destination from the mixing valve 70 via the second heat exchanger 3b, and includes a first hot water supply pipe section 80a and a second hot water supply pipe section 80b. The 1st hot water supply pipe part 80a connects the mixing valve 70 and the 2nd heat exchanger 3b, and the 2nd hot water supply pipe part 80b connects the 2nd heat exchanger 3b and the hot water supply destination. The second hot water supply pipe portion 80b in the hot water supply pipe line 80 functions as a hot water supply pipe. The hot water supply destination is a desired facility that consumes hot water such as a kitchen hot water tap, a bathtub, a hot water type floor heater, etc. In FIG. 1, one hot water tap 150 is shown as an example of the hot water supply destination. ing. Moreover, in FIG. 1, the flow direction of the hot water in the hot water supply pipe line 80 is indicated by a solid arrow D.

  The flow switch 83 is provided in the second hot water supply pipe portion 80b (hot water supply pipe) and detects the presence or absence of a water flow in the second hot water supply pipe portion 80b. Moreover, the temperature sensor 85 is provided in the 2nd hot water supply pipe part 80b (pipe for hot water supply), and detects the temperature of the hot water in this 2nd hot water supply pipe part 80b.

  The tank-side control device 100 is wired or wirelessly connected to the heat pump-side control device 15, the remote controller 120, and other predetermined components. In the illustrated example, a wired connection is made. The tank-side control device 100 includes commands such as a boiling operation start command input by the user from the remote controller 120 and operating conditions such as a boiling operation start time, a boiling temperature, and a hot water supply temperature input by the user from the remote controller 120. The operation of a predetermined component is controlled based on the information related to the above, the detection results of sensors such as the flow switch 83 and the temperature sensor 85, and the like. Specifically, operations of the heat pump side control device 15, the circulation pump 55, and the mixing valve 70 are controlled. In FIG. 1, the connection relationship between the tank-side control device 100 and each component is indicated by broken-line arrows.

  Of the above-described components constituting the tank unit 110, the remaining components excluding the water supply pipeline 40, the boiling circulation pipeline 50, and the hot water supply pipeline 80 are housed in an exterior case (not shown). ing. A part of each of the water supply pipe 40, the boiling circulation pipe 50, and the hot water supply pipe 80 extends to the outside of the outer case.

  The remote controller 120 is configured using an operation unit (not shown) having a plurality of input switches for inputting commands, information, and the like, and a flat display panel such as a liquid crystal display panel, and commands input from the operation unit And a display unit (not shown) for visually displaying information such as operating conditions received from the tank-side control device 100 using characters, figures, characters, and the like. The remote controller 120 sends commands, information, and the like input from the operation unit to the tank-side control device 100, and displays information such as operating conditions received from the tank-side control device 100 on the display unit. The remote controller 120 is installed near the hot water supply destination, for example.

  The heat pump water heater 130 having the above-described constituent members supplies water from the water supply pipe 40 to the hot water storage tank 30 to supply the hot water storage tank 30, the boiling circulation pipe 50, the mixing pipe 60, and the hot water supply pipe 80. After being filled with water, it is ready for use.

  For example, when the user inputs a boiling operation start command from the remote controller 120 or when the boiling start time input by the user from the remote controller 120 is reached, the circulation pump 55 is activated under the control of the tank side control device 100. A command is sent from the tank-side control device 100 to the heat pump-side control device 15, the refrigeration cycle unit 10 is started under the control of the heat pump-side control device 15, and the boiling operation is started.

  The boiling operation is continued until the tank-side control device 100 determines that a predetermined amount of hot water has been stored in the hot water storage tank 30 from a detection result of a temperature sensor (not shown) provided in the hot water storage tank 30. . During this time, water flows from the lower part of the hot water storage tank 30 into the forward pipe 50a of the circulation circuit 50 for boiling, and is passed through the first heat exchanger 3a, and is boiled up to hot water by the first heat exchanger 3a. Then, the water is returned from the upper part of the hot water storage tank 30 to the hot water storage tank 30 through the return pipe 50b (hot water storage pipe) of the boiling circulation pipe 50.

  When the user opens the hot-water tap 150 and the flow switch 83 detects the water flow in the second hot-water supply pipe portion 80b (hot-water supply pipe), the hot-water supply operation is started under the control of the tank-side control device 100. In the hot water supply operation, under the control of the tank-side control device 100, the valve opening on the mixing conduit 60 side and the valve opening on the second water supply pipe section 40b side of the mixing valve 70 are respectively adjusted, and the tank A control command is sent from the side control device 100 to the heat pump side control device 15, the refrigeration cycle unit 10 is started by the heat pump side control device 15, and the hot water passed from the mixing valve 70 to the second heat exchanger 3b Is heated by the second heat exchanger 3b. Then, the valve opening degree (mixing ratio of hot water) in the mixing valve 70 and the boiling capacity of the second heat exchanger 3b are feedback-controlled using the detection result of the temperature sensor 85, so that hot water is supplied to the hot water tap 150. The temperature is adjusted.

  The heat pump water heater 130 that performs the boiling operation and the hot water supply operation as described above has a feature in the hot water supply operation under the control of the heat pump side control device 15 and the tank side control device 100. The configurations and control contents of the heat pump side control device 15 and the tank side control device 100 will be described in detail with reference to FIGS. 2 and 3.

  FIG. 2 is a block diagram schematically showing a heat pump side control device and a tank side control device in the heat pump water heater shown in FIG. 1. As shown in the figure, the heat pump side control device 15 has a transmission / reception processing unit 11 and a control unit 13, and the tank side control device 100 includes a transmission / reception processing unit 91, a timer 93, a control unit 95, and a storage unit 97. Have.

  The transmission / reception processing unit 11 in the heat pump side control device 15 performs processing related to reception of a command from the tank side control device 100 and processing related to transmission of information to the tank side control device 100. In addition, the control unit 13 controls the operation of the refrigeration cycle unit 10 (see FIG. 1) according to the command received from the tank-side control device 100 by the transmission / reception processing unit 11. Therefore, the control unit 13 includes a communication control unit 13a and a heat pump control unit 13b.

  When the transmission / reception processing unit 11 receives a command from the tank-side control device 100, the communication control unit 13a transfers the command to the heat pump control unit 13b and controls the operation of the transmission / reception processing unit 11 to give a predetermined response. A signal is transmitted to the tank side control device. In addition, the heat pump control unit 13b performs operation control of the refrigeration cycle unit 10 in accordance with a command transferred by the communication control unit 13a. Specifically, the operations of the compressor 1, the expansion valve 5 and the evaporator 7 are controlled to start and stop each of the first heat exchanger 3a and the second heat exchanger 3b (see FIG. 1). And control the boiling capacity.

  On the other hand, the transmission / reception processing unit 91 in the tank-side control device 100 performs processing related to transmission of a command to the heat pump-side control device 15, processing related to reception of a response signal from the heat pump-side control device 15, commands from the remote controller 120, A process related to reception of information and a process related to transmission of information to the remote controller 120 (for example, the operation status of the heat pump water heater 130) are performed. The timer 93 operates under the control of the control unit 95, and measures the elapsed time since the control unit 95 instructs the heat pump side control device 15 to stop the operation of the refrigeration cycle unit 10.

  Based on the command and information from the remote controller 120 and the detection results of sensors such as the flow switch 83 and the temperature sensor 85, the control unit 95 performs a boiling operation and a hot water supply operation in the heat pump water heater 130 (see FIG. 1). Control the overall operation. Further, based on the detection results of each sensor, information related to the operation status of the heat pump water heater 130 is collected, and the operation of the transmission / reception processing unit 91 is controlled to transmit the information to the remote controller 120. In order to perform these controls, the control unit 95 includes a communication control unit 95a, a boiling control unit 95b, and a hot water supply temperature control unit 95c.

  When the transmission / reception processing unit 91 receives a boiling operation start command from the remote controller 120, the communication control unit 95a transfers the command to the boiling control unit 95b. In addition, the transmission / reception processing unit 91 stores various types of information received from the heat pump-side control device 15 and the remote controller 120 in the storage unit 97. Further, information is collected from each of the boiling control unit 95b and the hot water supply temperature control unit 95c, and information related to the operation status of the heat pump water heater 130, such as the completion of the boiling operation, the completion of the boiling operation, the hot water supply temperature, and the like is transmitted and received. The operation of 91 is controlled and transmitted to the remote controller 120.

  The boiling control unit 95b is a temperature sensor provided in the hot water storage tank 30 (see FIG. 1) and information related to the boiling temperature and the amount of boiling water input by the user from the remote controller 120 and stored in the storage unit 97. Using a detection result (not shown), a predetermined control command is sent to the heat pump side control device 15 during a boiling operation, and the operation of the circulation pump 55 (see FIG. 1) is controlled.

  The hot water supply temperature control unit 95c uses the information related to the hot water temperature input by the user from the remote controller 120 and stored in the storage unit 97, the detection result of the flow switch 83, and the detection result of the temperature sensor 85, to supply hot water. During operation, a predetermined control command is sent to the heat pump side control device 15 and the valve opening (mixing ratio of hot water) at the mixing valve 70 is controlled to adjust the hot water supply temperature from the hot water tap 150 (see FIG. 1). At this time, using the detection result of the temperature sensor 85, the boiling capacity of the refrigeration cycle unit 10 and the mixing ratio of hot water in the mixing valve 70 are feedback-controlled, and the second heat exchanger 3b to the second hot water supply pipe unit 80b. The temperature of hot water supplied to hot-water tap 150 through (see FIG. 1) is adjusted to the above-mentioned hot-water supply temperature. The operation of the refrigeration cycle unit 10 is indirectly controlled by sending a predetermined control command to the heat pump side control device 15.

  After the operation of the second heat exchanger 3b is stopped in the storage unit 97, the hot water temperature controller 95c can determine how much the current boiling capacity of the second heat exchanger 3b is. Is stored in advance by the manufacturer of the heat pump water heater 130. The data indicating the correspondence between the elapsed time of the second heat exchanger 3b and the boiling capacity of the second heat exchanger 3b is stored in advance. If necessary, the above data can include the correspondence between the outside air temperature and the boiling capacity of the second heat exchanger 3b. In this case, the outside air temperature is detected and the result is stored in the tank. A temperature sensor that communicates to the side control device 100 is installed at a desired location.

In FIG. 2, a signal line connecting the heat pump-side control device 15 and the tank-side control device 100 is denoted by reference numeral “SL ₁ ”, and a signal line connecting the flow switch 83 and the tank-side control device 100 is denoted by a reference numeral. A signal line that is indicated by “SL ₂ ” and that connects the temperature sensor 85 and the tank side control device 100 is indicated by a reference sign “SL ₃ ”, and a signal line that connects the remote controller 120 and the tank side control device 100 is indicated by a reference sign “SL”. ₁₀ ”.

  FIG. 3 is a flowchart schematically showing an example of control performed by the heat pump side control device and the tank side control device during the hot water supply operation. The illustrated example is a case where the hot water supply operation is started when the heat pump unit 20 is stopped. During the hot water supply operation, the heat pump side control device 15 and the tank side control device 100 (see FIG. 2) perform steps. Processing of S1 to S11 is performed. As already described, the hot water supply operation is started when the user opens the hot water tap 150 and the flow switch 83 detects a water flow in the second hot water supply pipe section 80b (see FIG. 1).

  In step S <b> 1 performed first, the hot water supply temperature control unit 95 c (see FIG. 2) of the tank side control device 100 that has received the water flow detection signal from the flow switch 83 instructs the heat pump side control device 15 to start the heat pump unit 20. To do. At this time, the hot water supply temperature control unit 95c also sends information related to the hot water supply temperature stored in the storage unit 97 (see FIG. 2) to the heat pump side control device 15. The heat pump side control device 15 that has received the above command and information activates the heat pump unit 20 by the heat pump control unit 13b, and freezes so that the boiling temperature in the second heat exchanger 3b becomes the above hot water supply temperature. Operation control of the cycle unit 10 (see FIG. 1) is started.

  Next, in step S2, which is performed, only the current boiling capacity of the second heat exchanger 3b is used to supply hot water at a predetermined temperature (the remote controller 120 (see FIG. 1) from the remote controller 120) to the hot water supply destination (hot water tap 150; see FIG. 1). The hot water supply temperature control unit 95c determines whether or not hot water supply at the input hot water supply temperature is possible. At this time, the hot water supply temperature control unit 95c obtains the time measurement result from the timer 93 (see FIG. 2), and the time measurement result and the data stored in the storage unit 97 (see FIG. 2), that is, the second heat exchanger. With respect to the current boiling capacity of the second heat exchanger 3b, using the above-described data showing the correspondence between the elapsed time after the operation of 3b stops and the boiling capacity of the second heat exchanger 3b. Make the above judgment.

  When it is determined in the above step S2 that it is impossible to supply hot water at a predetermined temperature to the hot water destination only with the current boiling capacity, the process proceeds to step S4 described later, and the predetermined temperature to the hot water destination only with the current boiling capacity. When it is determined that the hot water supply is possible, the process proceeds to step S3, where the hot water supply temperature control unit 95c fully opens the mixing valve 70 (see FIG. 1).

  Usually, a heat exchanger in a refrigeration cycle is not responsive, and a certain amount of time is required until the heat exchanger can be heated after the refrigeration cycle unit is started. For this reason, when an affirmative determination is made in step S2 performed immediately after the start of the hot water supply operation, whether the previous hot water supply operation has been completed, whether it is in a boiling operation, It is thought that it is in a state shortly after the lifting operation is finished. In such a case, if the temperature of the hot water flowing from the mixing valve 70 into the first hot water supply pipe section 80a (see FIG. 1) is increased, hot water higher than the hot water temperature specified by the user is discharged from the hot water tap 150. Since there is a danger, in step S3, the mixing valve 70 is fully opened on the water side, and hot water from the hot water tap 150 is prevented from being discharged.

  On the other hand, when it is determined in step S2 described above that it is impossible to supply hot water at a predetermined temperature to the hot water supply destination only with the current boiling capacity and the process proceeds to step S4, the hot water supply temperature stored in the storage unit 97 is related. Using the information and the detection results of temperature sensors (both not shown) provided in each of the hot water storage tank 30 and the second water supply pipe section 40b (see FIG. 1), the hot water supply temperature control section 95c uses the mixing valve 70. Adjust the operation. Specifically, the mixing ratio of the hot water in the mixing valve 70 is adjusted by adjusting the valve opening degree of the mixing valve 70, and the hot water supply temperature to the hot water tap 150 is adjusted to the hot water temperature specified by the user.

  In step S5, the hot water supply temperature control unit 95c readjusts the valve opening of the mixing valve 70 using the information related to the hot water supply temperature stored in the storage unit 97 and the detection result of the temperature sensor 85 (feedback control), The temperature of the hot water flowing from the second heat exchanger 3b into the second hot water supply pipe section 80b, and hence the hot water supply temperature to the hot water tap 150 are readjusted. If a negative determination is made in step S2 described above, the boiling capacity of the second heat exchanger 3b increases as time elapses from the start of the hot water supply operation. The valve opening on the 60 side gradually decreases, and the valve opening on the second water supply pipe portion 40b side gradually increases. When hot water supply at a predetermined temperature to the hot-water tap 150 becomes possible only with the current boiling capacity of the second heat exchanger 3b, the hot water tank side valve in the mixing valve 70 is closed, and the second water supply pipe Only the water passed through the mixing valve 70 from the section 40b flows into the first hot water supply pipe section 80a and is heated by the second heat exchanger 3b.

  In step S6, the hot water supply temperature control unit 95c determines whether or not the hot water supply to the hot water supply destination (hot water tap 150) is stopped based on the detection result of the flow switch 83. When the hot-water tap 150 is closed, there is no water flow in the second hot-water supply pipe portion 80b, so whether or not hot water supply is stopped can be determined based on the detection result of the flow switch 83. The temperature of the water flowing through the water supply pipe 40 (see FIG. 1) and the temperature of the hot water flowing through the mixing valve pipe 60 vary depending on the outside air temperature and the amount of hot water remaining in the hot water storage tank 30, and the second heat exchanger 3b Since the boiling capacity also changes depending on the elapsed time from the start of start-up and the amount of hot water supplied to the hot water tap 150, when it is determined in step S8 that hot water supply is not stopped, the flow returns to step S5 described above and the steps S5 and after are repeated. It is preferable to stabilize the hot water supply temperature to the hot water tap 150.

  On the other hand, when it is determined in step S6 that the hot water supply has been stopped, the process proceeds to step S7, and after the hot water supply temperature control unit 95c controls the operation of the timer 93 (see FIG. 2) to clear the time measurement result of the timer 93, The time elapsed (count) after the hot water supply stops is started. Moreover, the hot water supply temperature control unit 95c starts monitoring the time measurement result of the timer 93.

  In the next step S8, the heat pump side control device 15 or the tank side control device 100 keeps the second heat exchanger 3b in a heatable state so that hot water supply at a predetermined temperature to the hot water tap 150 can be resumed immediately. To do. For example, even if hot water supply is stopped, the hot water supply temperature control unit 95c does not instruct the heat pump control device 15 to stop the refrigeration cycle unit 10 and continues to operate the refrigeration cycle unit 10 as it is. The heat pump water heater 130 (see FIG. 1) can be configured to maintain a heatable state. When the hot water supply is stopped, the boiling control unit 95b (see FIG. 2) starts the boiling operation by the first heat exchanger 3a, thereby maintaining the second heat exchanger 3b in a heatable state. Thus, the heat pump water heater 130 can also be configured.

  For example, it is often necessary to intermittently supply hot water to the hot water tap 150, for example, when washing in the kitchen, so that when the hot water supply is stopped, the second heat exchanger 3b is stopped immediately. The convenience of the heat pump water heater 130 is enhanced by maintaining the second heat exchanger 3b in a heatable state until a certain time has elapsed. Also, in terms of the characteristics of boiling water in the heat pump unit 20, it is preferable to perform such operation control because continuous operation is more energy efficient than intermittent operation for a short time.

  Next, in step S9, the hot water supply temperature control unit 95c determines whether the hot water supply to the hot water tap 150 is stopped based on the detection result of the flow switch 83. When it is determined in step S9 that the hot water supply has been resumed, the process returns to the above-described step S3 and the steps from step S3 are repeated, and when it is determined that the hot water supply has not been resumed, the process proceeds to step S10.

  In step S10, hot water supply temperature control unit 95c determines whether or not the measured time (count number) of timer 93 exceeds the condition value. The above condition value is the maximum time for maintaining the second heat exchanger 3b in a heatable state even after the hot water supply is stopped. The condition value is determined by the manufacturer of the heat pump water heater 130 and stored in the storage unit 97 in advance. Stored.

  If it is determined in step S10 that the time measured (count number) of the timer 93 has not yet exceeded the condition value, the process returns to step S8 to repeat the steps after step S8. On the other hand, when it is determined that the time measured (count number) of the timer 93 exceeds the condition value, the process proceeds to step S11, where the hot water supply temperature control unit 95c instructs the heat pump control unit 13b to stop the refrigeration cycle unit 10, and the above instruction The heat pump control unit 13b that has received the operation stops the refrigeration cycle unit 10, and each of the heat pump side control device 15 and the tank side control device 100 ends the processing. Note that the timer 93 continues the time measurement started in step S7 until the next hot water supply ends (stops).

  In the heat pump water heater 130 in which the heat pump side control device 15 and the tank side control device 100 perform the above-mentioned control during the hot water supply operation, the hot water supply temperature is adjusted while operating the second heat exchanger 3b during the hot water supply operation. Even without consuming so much of the hot water inside, it is possible to supply hot water at a predetermined temperature to the hot water supply destination (hot-water tap 150). Further, hot water supply at a predetermined temperature can be performed at the hot water supply destination without using an electric switching valve other than the mixing valve 70. Therefore, in this heat pump water heater 130, even if the hot water storage tank 30 is small and its volume is small, it is possible to ensure high hot water supply capacity under simple control and prevent “hot water out”, and its manufacturing cost. Can be easily suppressed.

  Moreover, in the heat pump water heater 130, since the hot water storage tank 30 can be easily reduced in size and weight, raw materials required for manufacturing the heat pump water heater 130 can be easily reduced, and energy saving can be achieved. Can do.

  The heat pump water heater of the present invention has been described with reference to the embodiment. However, as described above, the present invention is not limited to the above embodiment. In the heat pump water heater of the present invention, the hot water stored in the hot water storage tank and the water flowing through the water supply pipe are mixed by passing through a mixing valve, and then heated by a heat exchanger and supplied to a desired hot water supply destination. Basically, the remaining configuration can be variously changed except that it is heated by passing water from the mixing valve to the heat exchanger during hot water supply.

  For example, the heat pump unit may be provided with a total of two heat exchangers, a first heat exchanger for boiling operation and a second heat exchanger for hot water supply operation, as described in the embodiment. In addition, only one heat exchanger that serves both for boiling operation and for hot water supply operation may be provided. The heat pump hot water supply includes a desired function other than the function of supplying hot water to a predetermined hot water supply destination, for example, a heat exchanger that uses hot water stored in a hot water storage tank as a heat source, and the heat exchanger supplies a bathtub or a hot water type floor heating device. It is also possible to add a function of reheating hot water that has been used at a reduced temperature.

  The contents of operation control of the heat exchanger for hot water supply (second heat exchanger described in the embodiment) can be selected as appropriate. For example, when hot water supply is started, the hot water supply temperature specified by the user without determining whether or not hot water supply at a predetermined temperature is possible at the hot water supply destination only with the current boiling capacity of the heat exchanger for hot water supply It is also possible to configure the heat pump water heater so as to start hot water supply at a somewhat lower hot water supply temperature and then feedback control the hot water supply temperature. In addition, the heat pump water heater can be configured to stop the heat exchanger for hot water supply as soon as the hot water supply to the hot water supply destination is stopped. However, from the viewpoint of obtaining a heat pump water heater with high convenience, as described in the embodiment, the hot water supply heat exchanger is heated for a predetermined time after the hot water supply to the hot water supply destination is stopped. It is preferable to keep it in a possible state.

  In addition to providing a dedicated control device for the heat pump unit, the tank-side control device may also serve as the heat pump-side control device. The heat pump water heater of the present invention can be variously modified, decorated, combined, etc. in addition to those described above.

  The heat pump water heater of the present invention can be suitably used as a home or business water heater.

It is the schematic which shows an example of the heat pump water heater of this invention. It is a block diagram which shows roughly the heat pump side control apparatus and tank side control apparatus in the heat pump water heater shown in FIG. It is a flowchart which shows roughly an example of the control which a heat pump side control apparatus and a tank side control apparatus perform at the time of the hot water supply operation of the heat pump water heater shown in FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 3 Heat exchanger 3a 1st heat exchanger 3b 2nd heat exchanger 10 Refrigeration cycle part 13 Control part 13a Communication control part 13b Heat pump control part 15 Heat pump side control apparatus 20 Heat pump unit 30 Hot water storage tank 40 Water supply line 40a 1st 1 water supply pipe part 40b 2nd water supply pipe part 50 Boiling circulation pipe 50a Outward pipe 50b Return pipe (pipe for hot water storage)
55 Circulating pump 60 Mixing line 70 Mixing valve 80 Hot water supply line 80a First hot water supply pipe part 80b Second hot water supply pipe part (hot water supply pipe)
83 Flow switch 85 Temperature sensor 95 Control unit 95a Communication control unit 95b Boiling control unit 95c Hot water supply temperature control unit 100 Tank side control device 130 Heat pump water heater 150 Hot water tap

Claims (4)

A hot water storage tank for storing water supplied from a water supply pipeline;
A first heat exchanger for boiling water passed from the hot water storage tank into hot water;
A hot water storage pipe for supplying hot water boiled in the first heat exchanger to the hot water storage tank;
A mixing valve for mixing hot water passed from the hot water storage tank and water passed from the water supply pipe;
A second heat exchanger for heating hot water passed from the mixing valve;
A hot water supply pipe for supplying hot water heated by the second heat exchanger to a hot water supply destination;
A temperature sensor for detecting the temperature of the hot water in the hot water supply pipe;
The second heat exchanger is operated at the time of hot water supply to the hot water supply destination, and the hot water temperature to the hot water supply destination is controlled by controlling the mixing ratio of hot water in the mixing valve using the detection result of the temperature sensor. A hot water temperature controller to be adjusted;
The heat pump water heater characterized by having. The hot water temperature controller is
Instructing activation of the second heat exchanger at the start of hot water supply to the hot water supply destination,
The hot water supply temperature is adjusted by adjusting the mixing ratio of hot water in the mixing valve until hot water supply at a predetermined temperature to the hot water supply destination becomes possible only with the current boiling capacity of the second heat exchanger. And
When hot water supply at a predetermined temperature to the hot water supply destination is possible only with the current boiling capacity of the second heat exchanger, the hot water tank side valve in the mixing valve is closed, and the mixing from the water supply line Only the water passed through the valve is passed through the second heat exchanger and heated by the second heat exchanger to adjust the hot water supply temperature.
The heat pump water heater according to claim 1.   It further has a boiling control unit capable of passing water from the hot water storage tank to the first heat exchanger and boiling the hot water by the first heat exchanger even during hot water supply to the hot water supply destination. The heat pump water heater according to claim 1 or 2.   The hot water supply temperature control unit causes the boiling control unit to boil hot water using the first heat exchanger for a predetermined time after hot water supply to the hot water supply destination is stopped. The heat pump water heater according to claim 3, wherein

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