JP6133690B2 - Water heater - Google Patents

Description

  Embodiments described herein relate generally to a water heater.

  In recent years, a water heater having a heat pump unit and a hot water storage tank unit including a hot water storage tank has become widespread. In such a water heater, tap water supplied from a water pipe is temporarily stored in a hot water storage tank, and the tap water stored in the hot water storage tank is boiled by a heat pump unit using cheap nighttime electric power at night. The raised hot water is stored in a hot water storage tank, and the hot water in the hot water storage tank is used in the daytime.

  In such a water heater, it is necessary to prevent freezing of pipes and the like through which tap water flows in the winter, and this freezing prevention can be achieved by using a heater to raise the surface temperature of the pipe or using a circulation pump to supply hot water to the pipe. A method of passing water (see Patent Document 1 below) is adopted.

JP 2011-94922 A

  However, the method of increasing the surface temperature of the pipe using the heater is not preferable because the manufacturing cost increases due to the increase in the number of parts.

  In addition, there is a case in which hot water is not allowed to flow from the point of water channel design in the system in which hot water is passed through the piping using a circulation pump.

  An object of an embodiment of the present invention is to provide a water heater that can prevent the pipe from freezing without increasing the surface temperature of the pipe using a heater or passing hot water through the pipe. .

The hot water supply device of the embodiment includes a hot water storage tank unit having a hot water storage tank for storing hot water, a hot water tank connected to the hot water storage tank, a hot water taking out from the hot water storage tank, and hot water having a temperature lower than that of the hot water taken out from the hot water storage tank. Supply path, a mixing valve for mixing hot water in the extraction path and hot water in the supply path, a circulation path for returning hot water from the upstream side of the mixing valve in the extraction path to the hot water storage tank, and circulating the hot water in the circulation path A circulation pump, a flow of hot water in the extraction path, a flow of hot water in the supply path, a controller for controlling the opening of the mixing valve and the drive of the circulation pump , and the control section from the extraction path and the supply path to the mixing valve The flow of the water is stopped, the mixing valve is opened, hot water is circulated through the hot water storage tank, the extraction path and the circulation path, and then the circulation pump is stopped and the mixing valve is closed after a predetermined time has elapsed. that makes And butterflies.

It is a system diagram of a heat pump type water heater.

  FIG. 1 is a system diagram of a heat pump type water heater 1, and the water heater 1 includes a hot water storage tank unit 2 indicated by a broken line, a heat pump unit 3 indicated by a broken line, and a control unit 4. The control unit 4 includes a CPU, a ROM, a RAM, and the like, and controls each component of the water heater 1. A heat pump unit 3 and a bathtub 5 are connected to the hot water storage tank unit 2 by piping.

  The hot water storage tank unit 2 includes a hot water storage tank 6, a water supply connection port 7, a hot water supply connection port 8, a heat pump return pipe connection port 9, a heat pump return pipe connection port 10, a bath return pipe connection port 11, and a bath return pipe. It has a connection port 12 and an overpressure prevention valve 13.

  The hot water storage tank 6 includes first and second upper connection ports 14 and 15, first and second lower connection ports 16 and 17, and a plurality of temperature sensors 18. The plurality of temperature sensors 18 are arranged at substantially equal intervals along the vertical direction of the hot water storage tank 6, detect the temperature of the hot water (or hot water) in the hot water storage tank 6, and inform the controller 4 of the detected temperature information. I have come to tell you.

  The heat pump unit 3 is means for boiling hot water to generate hot water, and includes a compressor (not shown), a heating heat exchanger 19 functioning as a condenser, and an expansion valve (not shown). And a refrigeration cycle in which an evaporator (not shown) is connected by a refrigerant pipe. Further, the heat pump unit 3 is provided with an outside air temperature sensor 20 which is an outside air temperature detecting means for detecting the outside air temperature, and transmits information on the detected outside air temperature to the control unit 4. The heat exchanger 19 is connected to the pipe connection port 9 for the heat pump and the heat pump return pipe connection port 10 of the hot water storage tank unit 2 via the pipes 19A and 19B.

  The bathtub 5 is connected to the bath return pipe connection port 11 and the bath outlet pipe connection port 12 of the hot water storage tank unit 2 via the pipes 5A and 5B.

  Next, various components provided in the hot water storage tank unit 2 will be described.

  First, the supply path 21, the intake path 22, the take-out path 23, and peripheral elements that are pipes will be described.

  The supply path 21 is a pipe that supplies tap water supplied from a water pipe (not shown) to the hot water storage tank 6, a bath mixing valve 29, which will be described later, and a hot water mixing valve 42. In the middle of the supply path 21, a pressure reducing valve 24 that suppresses the pressure of tap water within a set value is provided. The supply path 21 is downstream of the pressure reducing valve 24 along the flow direction of tap water, and the vicinity of the bath mixing valve 29 and the hot water mixing valve 42 is made of resin.

  The intake path 22 is provided between the first upper connection port 14 of the hot water storage tank 6 and the heat pump return pipe connection port 10. A boiling three-way valve 25 is provided in the intake path 22, and the boiling three-way valve 25 is connected to the lower pipe 26. One end of the lower pipe 26 is connected to the first lower connection port 16 of the hot water storage tank 6, and the above-described overpressure prevention valve 13 is provided in the lower pipe 26. A boiling pump 27 is provided between the connection side of the boiling three-way valve 25 to the lower pipe 26 and the heat pump outgoing pipe connection port 9. The inlet side of the boiling three-way valve 25 is connected to the heat pump return pipe connection port 10.

  The take-out path 23 is provided between the second upper connection port 15 of the hot water storage tank 6 and the bath return pipe connection port 11. In the middle of the take-out path 23, a pressure relief valve 28, a bath mixing valve 29 which is a mixing valve, an electromagnetic valve 30, a bath flow sensor 31, a silver ion generation unit 32, a flow switch 33, and a water level sensor. 34 is provided.

  The pressure relief valve 28 is a valve that releases pressure when the pressure in the hot water storage tank 6 and the take-out path 23 rises to a set value or more, and the other end of the pipe 35 to which the pressure relief valve 28 is connected at one end. Is connected to the lower pipe 26.

  The bath mixing valve 29 mixes hot water taken out from the upper part of the hot water storage tank 6 with tap water having a temperature lower than the hot water in the hot water storage tank 6 supplied through the supply path 21 and having a specified temperature. As will be described later, the valve is opened when the supply path 21 through which the tap water flows is prevented from freezing.

  The solenoid valve 30 is configured to supply hot water mixed by the bath mixing valve 29 to the bathtub 5 by being opened. The bath flow sensor 31 detects the flow rate of hot water supplied to the bathtub 5, and the water level sensor 34 detects the water level of hot water supplied into the bathtub 5. When the water level reaches the set value, the supply of hot water into the bathtub 5 is stopped.

  The silver ion generation unit 32 has a pair of silver electrodes in the pipe line, generates silver ions by applying a voltage between these electrodes, and supplies the generated silver ions into the bathtub 5 together with hot water. It is like that. By supplying silver ions into the bathtub 5, the antibacterial power in the bathtub 5 is increased.

  Further, the hot water storage tank unit 2 is provided with a first circulation path 36 for circulating hot water in the hot water storage tank 6 and a second circulation path 37 for circulating hot water in the bathtub 5.

  The first circulation path 36 is provided between the upstream side of the bath mixing valve 29 in the extraction path 23 and the first upper connection port 14 of the hot water storage tank 6, and a part of the first circulation path 36 is shared with a part of the intake path 22. ing. In the middle of the first circulation path 36, a reheating pump 38 that is a circulation pump and a reheating heat exchanger 39 for reheating are provided.

  When the reheating pump 38 is driven, the hot water in the hot water storage tank 6 is circulated through a part of the extraction path 23 and the first circulation path 36 and returned to the hot water storage tank 6.

  The additional cooking heat exchanger 39 will be described later.

  The second circulation path 37 is provided between the bath outlet pipe connection port 12 and the bath return pipe connection port 11, and a part of the second circulation path 37 is shared with a part of the extraction path 23. An additional cooking heat exchanger 39 and a bath pump 40 are provided in the middle of the second circulation path 37.

  When the bath pump 40 is driven, the hot water in the bathtub 5 flows and circulates sequentially through the pipe 5A, the flow switch 33, the additional cooking heat exchanger 39, the second circulation path 37, and the pipe 5B. .

  In the additional cooking heat exchanger 39, hot water in the bathtub 5 circulating in the second circulation path 37 and hot water in the upper part of the hot water storage tank 6 circulating in the first circulation path 36 flow inside. The hot water is heated by the temperature difference between the hot water and the hot water, the temperature rises, and the hot water in the bathtub 5 is chased away.

  The hot water storage tank unit 2 is provided with a second extraction path 41. The second extraction path 41 is provided between the second upper connection port 15 and the hot water supply connection port 8 of the hot water storage tank 6. A hot water mixing valve 42 and a hot water flow rate sensor 43 are provided in the middle of the second extraction path 41. A supply path 21 for supplying tap water is connected to the hot water mixing valve 42.

  The hot water mixing valve 42 mixes hot water taken out from the upper part of the hot water storage tank 6 and tap water supplied through the supply path 21 to generate hot water having a specified temperature.

  Freezing prevention heaters 44 are attached to a plurality of locations in the hot water storage tank unit 2 through which low-temperature hot water such as tap water flows. In addition, the freeze prevention heater is not attached to the resin part in the supply path 21.

  In such a configuration, the operation state of the water heater 1 will be described. First, a case where tap water is stored in the hot water storage tank 6 and the tap water is boiled will be described.

  Tap water supplied from a water pipe (not shown) flows through the water supply connection port 7 and the supply path 21 and is supplied from the second lower connection port 17 into the hot water storage tank 6. And the refrigeration cycle of the heat pump unit 3 is driven by using inexpensive late-night power at night, and the boiling pump 27 is further driven. At this time, the boiling three-way valve 25 is switched so that the heat pump return pipe connection port 10 and the intake path 22 communicate with each other. Note that the refrigeration cycle, pump driving and valve opening / closing, as well as driving of other pumps to be described later and opening / closing of other valves are performed under the control of the control unit 4.

  When the boiling pump 27 is driven, the tap water stored in the lower part of the hot water storage tank 6 flows through the lower pipe 26 and the pipe 19 </ b> A and is sent to the heat exchanger 19 of the heat pump unit 3. It is heated to become hot water. The hot water flows through the pipe 19 b and the intake path 22, is supplied into the hot water storage tank 6 from the first upper connection port 14, and is stored in the hot water storage tank 6. The hot water storage tank 6 stores hot water so that the hottest hot water is located at the top.

  Next, a case where hot water is supplied to the bathtub 5 using hot water stored in the hot water storage tank 6 will be described.

  When hot water is supplied to the bathtub 5, the temperature of the hot water supplied to the bathtub 5 is set in a temperature setting unit (not shown), and the operation of starting the supply of hot water is performed, whereby the bath mixing valve is controlled by the control unit 4. The opening degree of 29 is adjusted, and the solenoid valve 30 is opened.

  By adjusting the opening of the bath mixing valve 29, the hot water supplied from the hot water storage tank 6 through the take-out path 23 and the tap water supplied from the water pipe through the supply path 21 are mixed in the bath. By mixing with the valve 29, it becomes hot water having a set temperature, flows through the portion on the downstream side of the bath mixing valve 29 in the extraction path 23, the pipe 5 </ b> A and the pipe 5 </ b> B, and is supplied into the bathtub 5. In this case, the silver ion generation unit 32 is driven to generate silver ions, and the generated silver ions are supplied into the bathtub 5 together with hot water. When the hot water supplied into the bathtub 5 reaches a set amount, the solenoid valve 30 is closed and the supply of hot water into the bathtub 5 is stopped.

  When hot water is used in a place other than the bathtub 5 (for example, in the kitchen), the hot water in the hot water storage tank 6 flows through the extraction path 23 and the second extraction path 41 to reach the hot water mixing valve 42. At the same time, tap water flowing in the supply path 21 reaches the hot water mixing valve 42, and hot water and tap water are mixed by the hot water mixing valve 42 to form hot water, and hot water is supplied from the hot water connection port 8 to each hot water supply location.

  Next, a case where hot water in the bathtub 5 is chased will be described. When reheating hot water in the bathtub 5, the reheating pump 38 and the bath pump 40 are driven.

  By driving the reheating pump 38, the hot water in the upper part of the hot water storage tank 6 circulates through a part of the extraction path 23 and the first circulation path 36 via the additional heat exchanger 39. On the other hand, when the bath pump 40 is driven, hot water in the bathtub 5 is additionally cooked and circulates in the pipe 5A, the second circulation path 37, and the pipe 5B via the heat exchanger 39.

  In the additional cooking heat exchanger 39, heat exchange is performed between the hot water in the hot water storage tank 6 that circulates in the first circulation path 36 and the hot water in the bathtub 5 that circulates in the second circulation path 37. Then, the temperature of the hot water in the bathtub 5 rises, and the hot water whose temperature has risen is returned to the bathtub 5 so that the hot water in the bathtub 5 is replenished.

  Next, prevention of freezing of pipes and the like through which low-temperature hot water such as tap water flows will be described. In a place where the antifreezing heater 44 is provided in the piping, the antifreezing is performed by energizing the antifreezing heater 44. However, the vicinity of the bath mixing valve 29 in the supply path 21 is made of resin, and no anti-freezing heater is provided.

  When the resin portion in the supply path 21 is prevented from freezing, the flow of hot water from the extraction path 23 to the bath mixing valve 29 and the flow of tap water from the supply path 21 to the bath mixing valve 29 are stopped. In the state, the bath mixing valve 29 is opened. As the valve opening position of the bath mixing valve 29 in this case, for example, an intermediate position in the fully opened state is preferable. The hot water or tap water flow to the bath mixing valve 29 is stopped by closing the electromagnetic valve 30 under the control of the control unit 4.

  When the bath mixing valve 29 is opened in a state where the flow of hot water or tap water to the bath mixing valve 29 is stopped, the heat of the hot water in the extraction path 23 is opened via the bath mixing valve 29 opened. It is transmitted to the tap water in the supply path 21, and the supply path 21 is prevented from freezing by heat transfer.

  In this way, the resin portion in the supply path 21 can be prevented from freezing without using a freezing prevention heater. Moreover, when preventing this freezing, the flow of hot water or tap water to the bath mixing valve 29 is reduced without adding a new configuration to the conventional water heater, for example, a configuration for passing hot water in the supply path 21. The control can be performed by stopping and opening the bath mixing valve 29.

  And since a heater is not used for the resin-made part in the supply path | route 21, a number of parts can be reduced and manufacturing cost can be reduced.

  The timing at which the resin portion in the supply path 21 is prevented from freezing is preferably performed when the outside air temperature sensor 20 detects that the outside air temperature has decreased to a predetermined temperature (for example, −10 ° C.) or less. By performing freezing prevention based on the detection result of the outside air temperature sensor 20, it is possible to reliably prevent freezing. Further, by maintaining the bath mixing valve 29 in the open state when the outside air temperature is equal to or lower than a predetermined value, the frequency of the opening and closing operation of the bath mixing valve 29 can be suppressed, and the component life of the bath mixing valve 29 is shortened. Freezing prevention can be performed without this.

  Further, when the supply path 21 is prevented from freezing by opening the bath mixing valve 29, it is preferable to drive the reheating pump 38 and circulate the hot water in the hot water storage tank 6 in the second circulation path 36. It is.

  As the hot water in the hot water storage tank 6 circulates in the second circulation path 36, the hot water taken out from the hot water storage tank 6 passes through the position of the bath mixing valve 29. Thereby, the heat transfer from warm water to the tap water in the supply path 21 can be promoted, and the effect of preventing the freezing of the supply path 21 can be enhanced.

  Further, in order to prevent the supply path 21 from freezing, when the reheating pump 38 is driven to circulate the hot water in the hot water storage tank 6 in the second circulation path 36, the timing for stopping the reheating pump 38 and the bath mixing valve It is preferable to synchronize the timing at which the valve 29 is closed. Here, “synchronization” means that the bath mixing valve 29 is closed after a predetermined time (for example, several minutes) has elapsed since the driving of the reheating pump 38 was stopped. The heat transfer performed via the bath mixing valve 29 is the largest immediately after the driving of the reheating pump 38 is stopped. Therefore, the bath mixing valve 29 is closed with a delay of several minutes after the driving of the reheating pump 38 is stopped. By doing so, the effect of preventing freezing of the supply path 21 can be enhanced.

  As mentioned above, although some embodiment of this invention was described, these embodiment is shown as an example and is not intending limiting the range of invention. These embodiments can be implemented in various other forms, and various omissions, replacements, and changes can be made without departing from the scope of the invention. These embodiments and their modifications are included in the scope and gist of the invention, and are also included in the invention described in the claims and the equivalents thereof.

DESCRIPTION OF SYMBOLS 2 ... Hot water storage tank unit, 4 ... Control part, 6 ... Hot water storage tank, 20 ... Outside temperature sensor (outside temperature detection means), 21 ... Supply path, 23 ... Extraction path, 29 ... Bath mixing valve (mixing valve), 36 ... First circulation path, 38 ... reheating pump (circulation pump)

Claims (1)

A hot water storage tank unit equipped with a hot water storage tank for storing hot water,
An extraction path connected to the hot water storage tank for extracting hot water from the hot water storage tank;
A supply path for supplying hot water having a temperature lower than that of the hot water taken out from the take-out path;
A mixing valve for mixing the hot water in the take-out path and the hot water in the supply path;
A circulation path for returning hot water to the hot water storage tank from the upstream side of the mixing valve of the extraction path;
A circulation pump for circulating hot water in the circulation path;
A hot water flow in the take-out path, a hot water flow in the supply path, an opening of the mixing valve, and a controller for controlling the driving of the circulation pump ;
The controller stops the flow from the take-out path and the supply path to the mixing valve, opens the mixing valve, and circulates hot water through the hot water storage tank, the take-out path, and the circulation path. The hot water heater is characterized in that the mixing valve is closed after a predetermined time has elapsed after the circulation pump is stopped .

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