JP5041914B2 - Water heater - Google Patents

Description

  The present invention relates to a hot water supply apparatus that utilizes hot water in a hot water storage tank for hot water supply and heat exchange with a heat load.

  Conventionally, in a hot water supply system, during boiling operation, water is taken out from the lower part of the hot water tank and heated by the heat pump unit, and the heated water is taken into the upper part of the hot water tank, so that the specific gravity of hot water and water having different temperatures is increased. Due to the difference, the hot water does not mix with the water in the order from the upper side of the hot water tank through the mixed layer of hot water and water formed between the hot water on the upper side and the lower side of the hot water tank. Hot water is stored.

  The hot water stored in the hot water storage tank is taken out from the upper part of the hot water storage tank and used for hot water supply, and also used as a heat source for heat load such as reheating of the hot water in the bathtub and heating.

  Generally, when the hot water taken out from the upper part of the hot water storage tank and the hot water in the bathtub are exchanged with a heat exchanger, and the hot water in the bathtub is chased away, the hot water that is exchanged with the hot water in the bathtub is the heat exchanger. Since the heat is taken away and becomes hot water (eg, about 40 ° C. to 65 ° C.), the hot water in the upper part of the hot water tank is returned to the lower part of the hot water tank so as not to lower the temperature.

  In this case, assuming that the temperature of the hot water at the upper part of the hot water tank is 80 ° C, the temperature of the water at the lower part of the hot water tank is 10 ° C, and the temperature of the medium hot water that has passed through the heat exchanger is 50 ° C, the heat exchanger is The medium-temperature water that has passed through 50 ° C is mixed with 10 ° C water at the bottom of the hot water tank, and the temperature of the water at the bottom of the hot water tank rises to, for example, about 20 ° C. For this reason, the amount of heat that the medium-temperature water has is merely used for increasing the temperature of the water in the lower part of the hot water storage tank, and is wasted. In addition, since the temperature of the water in the lower part of the hot water storage tank is made higher than the feed water temperature, when boiling using a heat pump unit, the temperature of the water to be boiled becomes high, so that the boiling efficiency (COP) is increased. It will decline.

Therefore, instead of returning the intermediate temperature water that has passed through the heat exchanger to the lower part of the hot water storage tank, by returning it to the vicinity of the mixed layer between the hot water and the water in the hot water storage tank that is substantially the same as the temperature of the intermediate temperature water, There is a configuration in which a decrease in boiling efficiency (COP) due to an increase in the temperature of water in the lower part of the hot water storage tank is provided. In this case, the side surface of the hot water storage tank is provided with a plurality of return ports for returning the intermediate temperature water to the hot water storage tank at the intermediate portion between the upper hot water region and the lower hot water region, and the hot water temperature in the hot water storage tank. A hot water storage tank that has multiple thermistors that detect water temperature at different heights in the vertical direction, and the temperature of the hot water in the hot water tank detected by each thermistor is approximately the same as the temperature of the hot water. The medium temperature water is returned to the hot water storage tank through the return port corresponding to the hot water area inside the hot water tank, so that the temperature gradient of the hot water in the hot water tank is prevented from being disturbed. A decrease in boiling efficiency due to the heat pump unit is prevented (for example, see Patent Document 1).
Japanese Patent No. 3888117 (page 5-10, FIG. 1)

  As described above, when the medium temperature water that has passed through the heat exchanger is returned to the water area at the bottom of the hot water storage tank, the amount of heat that the medium temperature water has is only used to increase the temperature of the water, and is used for hot water supply. It can't be done and is wasted, reducing the amount of hot water available for hot water supply.

  In addition, the medium-temperature water that has passed through the heat exchanger is returned to the vicinity of the mixed layer of hot water and water in the hot water storage tank that is substantially the same as the temperature of the medium-temperature water by selecting one of the plurality of return ports. If the temperature gradient of the hot water in the tank is prevented from being disturbed, the medium hot water is returned to the lower water area of the hot water storage tank when the hot water area is close to the position of the multiple return ports. In addition, when the water region is close to the position of the multiple return ports, or when the temperature of the medium temperature water is lower than the temperature of the mixed layer near the multiple return ports, the medium temperature water is Will be returned to the water area. Therefore, if the intermediate temperature water that has passed through the heat exchanger is returned in accordance with the temperature gradient of the hot water in the hot water storage tank, the intermediate temperature water may be returned to the water region below the hot water storage tank, and the amount of heat that the intermediate temperature water has is reduced. It is only used to increase the temperature of the water, it cannot be used for hot water supply, is wasted, and the amount of hot water that can be used for hot water supply is reduced.

  The present invention has been made in view of such points, and can be effectively used for hot water supply without wasting the amount of heat of the hot water that has passed through the heat exchanger that exchanges heat with the heat load, and can increase the amount of hot water that can be used for hot water supply. It aims at providing a hot-water supply apparatus.

  The hot water supply device according to claim 1 is a hot water storage tank that stores hot water, a heat exchanger that is disposed outside the hot water storage tank and exchanges heat between the hot water in the hot water storage tank and a heat load side, An extraction path for extracting hot water and leading it to the heat exchanger, a plurality of intake paths capable of returning the hot water that has passed through the heat exchanger to the upper, middle, and lower portions of the hot water storage tank, respectively, and the plurality of intake paths A thermal load circuit having switching means for switching to any one of the inlet paths, and at least the upper, middle and lower positions of the hot water tank to which the intake path is connected. Temperature detection means for detecting the temperature of the hot water, and hot water in the hot water storage tank in the vicinity of the upper, middle and lower positions of the hot water storage tank to which the intake path is connected based on the detection of the temperature detection means It is determined whether the temperature is higher than the temperature that can be used for hot water supply, and the intake means is configured to return the hot water that has passed through the heat exchanger to the position of the hot water storage tank that is determined to be higher than the temperature that can be used for hot water supply. And a control unit for switching between.

  The hot water supply device according to claim 2 is the hot water supply device according to claim 1, wherein the controller is arranged at a lower portion of the hot water storage tank if the temperature of the hot water near the position of the lower portion of the hot water storage tank is higher than a temperature usable for hot water supply. The switching means is controlled so as to switch to an intake path for returning hot water that has passed through the heat exchanger, and the temperature of the hot water near the lower position of the hot water storage tank is lower than the temperature that can be used for hot water supply, and the intermediate portion of the hot water storage tank If the temperature of the hot water in the vicinity of the position is equal to or higher than the temperature that can be used for hot water supply, the switching means is controlled to switch to an intake path for returning the hot water that has passed through the heat exchanger to an intermediate portion of the hot water storage tank, If the temperature of the hot water near the position of the intermediate portion of the hot water storage tank is lower than the temperature that can be used for hot water supply, the switching means is switched to an intake path for returning the hot water that has passed through the heat exchanger to the upper part of the hot water storage tank. Control It is intended.

  The hot water supply apparatus according to claim 3 is the hot water supply apparatus according to claim 1 or 2, wherein a heat pump unit that boils hot water, a boiling extraction path that takes out water in a hot water storage tank and guides it to the heat pump unit, and the heat pump. A boiling circuit having a boiling intake path for returning hot water boiled through the unit to the hot water storage tank, and the boiling intake path of the boiling circuit is connected to the heat load circuit. It is shared with the inlet path and the switching means, and is switched to any one of a plurality of intake paths to return the hot water that has passed through the heat pump unit to the hot water storage tank.

  According to the hot water supply apparatus of claim 1, whether the temperature of the hot water in the hot water storage tank in the vicinity of the upper, middle and lower positions of the hot water storage tank to which each intake path is connected is higher than the temperature that can be used for hot water supply. In order to switch to an intake path that returns hot water that has passed through the heat exchanger to a hot water tank position that is determined to be higher than the temperature that can be used for hot water supply, the hot water that has passed through the heat exchanger is The hot water that has passed through the heat exchanger can be effectively used for hot water supply without wasting it, and more hot water can be used for hot water supply.

  According to the hot water supply device of claim 2, in addition to the effect of the hot water supply device of claim 1, the hot water in the hot water storage tank is used for hot water supply, and the temperature of the hot water in the hot water storage tank is higher than the temperature that can be used for hot water supply. Even if the area rises, the hot water that has passed through the heat exchanger can be returned in the order of the lower, middle, and upper parts of the hot water storage tank, so that the hot water that has passed through the heat exchanger can be used for hot water supply to the hot water storage tank. It can be reliably returned to the position of hot water above the temperature.

  According to the hot water supply apparatus according to claim 3, in addition to the effect of the hot water supply apparatus according to claim 1 or 2, the intake path for raising the heating circuit by the heat pump unit is replaced with the intake path of the heat load circuit and switching. Since the hot water that is shared with the means and switched to any one of the plurality of intake paths and passes through the heat pump unit can be returned to the hot water storage tank, the structure can be simplified and the cost can be reduced.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 shows a first embodiment, and a hot water supply device 11 includes a main body unit 12 and an outdoor unit 13 for boiling hot water, and has a function of purging bathtub water stretched on a bathtub 14. Yes.

  The main unit 12 has a hot water storage tank 17 for storing hot water. The hot water storage tank 17 includes an upper position of the hot water storage tank 17 and a 1/5 position and a 2/5 position corresponding to the capacity from the upper portion of the hot water storage tank 17. The thermistors 18a to 18f as temperature detecting means for detecting the hot water temperature in the hot water storage tank 17 are disposed at the 3/5 position, the 4/5 position, and the lower position of the hot water storage tank 17, respectively.

  A water supply path 20 connected to a water supply source such as a water pipe is connected to the lower part of the hot water storage tank 17. The water supply path 20 is provided with a pressure reducing valve 21 for reducing the water supply pressure and a check valve 22 for restricting the backflow.

  An upper take-out path 25 is connected to the upper part of the hot water tank 17, and an intermediate part take-out path 26 is located between the thermistor 18b at the 1/5 position and the thermistor 18c at the 2/5 position, which is the intermediate position in the vertical direction of the hot water tank 17. It is connected. A check valve 27 that allows hot water to flow only in the direction of removing hot water from the intermediate portion of the hot water storage tank 17 is disposed in the intermediate portion extraction path 26. The upper take-out path 25 and the intermediate take-out path 26 are connected to a regulating valve 28 that is a motorized valve, and by this regulating valve 28, the hot water in the upper part of the hot water storage tank 17 taken out from the upper take-out path 25 and the intermediate part take-out path 26 are connected. The hot water storage tank 17 is taken out by adjusting the mixing ratio with the hot water in the intermediate part. The mixing ratio that can be adjusted by the adjusting valve 28 includes the case where either one is 100% and the other is 0%. The adjustment valve 28 is connected to a hot water supply path 29 for supplying the hot water taken out. The hot water supply path 29 is provided with an extraction temperature detection sensor 30 as an extraction temperature detection means for detecting the temperature of the hot water. The upper extraction path 25, the intermediate section extraction path 26, the regulating valve 28, and the hot water supply path 29 form an extraction path 31 for extracting hot water from the hot water storage tank 17.

  Further, the hot water supply path 29 (extraction path 31) and the water supply path 20 are respectively connected to a mixing valve 34 as hot water temperature adjusting means for hot water supply and a mixing valve 35 as hot water temperature adjusting means for bathtubs. These mixing valves 34 and 35 mix hot water from the hot water supply path 29 (extraction path 31) and water from the water supply path 20 to supply hot water at a predetermined temperature. The mixing ratio that can be adjusted by the mixing valves 34 and 35 includes the case where either one is 100% and the other is 0%.

The hot water supply path 29 and the water supply path 20 connected to the mixing valves 34 and 35 are provided with check valves 36 and 37 for restricting the back flow to the hot water supply path 29 side and the water supply path 20 side, respectively.

  The hot water mixing valve 34 supplies hot water having a hot water supply set temperature set by, for example, a main remote controller installed in a kitchen or the like, a bathroom remote controller installed in a bathroom, or the like. A hot water supply passage 38 for supplying hot water to a predetermined hot water supply place is connected to the mixing valve 34 for hot water supply, and a flow rate sensor 39 for measuring the flow rate and a hot water supply temperature sensor 40 for detecting the temperature are provided in the hot water supply passage 38. Yes.

  The mixing valve 35 for the bathtub supplies hot water at a hot water set temperature set by the main remote controller installed in the kitchen or the bathroom or the bathroom remote controller installed in the bathroom, for example, or at the time of reheating operation by the bathroom remote controller Supply hot water at a temperature according to the water repulsion ability. This bathtub mixing valve 35 is connected to a bathtub hot water supply passage 41 for supplying hot water to the bathtub 14, and the bathtub hot water supply passage 41 is provided with a water supply electromagnetic valve or the like as a hot water supply means for bathtubs for opening and closing the flow path. 42 is arranged.

  In addition, on the downstream side of the connection point of the mixing valves 34 and 35 in the hot water supply path 29 (extraction path 31), a check valve 43 that restricts the backflow to the upstream side, and the bathtub water in the bathtub 14 on the heat load side A return path 45 is connected via a heat exchanger 44 for heat exchange as a heat exchanger for heat exchange to return the hot water that has passed through the heat exchanger 44 for heat return to the hot water storage tank 17. In this return path 45, for hot water, the hot water is taken out from the hot water storage tank 17 through the extraction path 31 and the hot water that has passed through the heat exchanger for hot water 44 is circulated so as to return to the hot water storage tank 17 through the return path 45. A circulation pump 46 is provided, and an intake temperature detection sensor 51 is provided as an intake temperature detection means for detecting the temperature of the hot water that has passed through the heat exchanger for remedy 44.

  A switching valve 47 as switching means is connected to the return path 45. The switching valve 47 is an upper intake path 48 connected to the upper part of the hot water storage tank 17, and an intermediate position in the vertical direction of the hot water storage tank 17. The intermediate intake path 49 connected between the thermistor 18d at the / 5 position and the thermistor 18e at the 4/5 position, and the lower intake path 50 connected to the lower part of the hot water tank 17 through the water supply path 20 are connected. Yes. By this switching valve 47, the return path 45 is switched so that any one of the upper intake path 48, the intermediate part intake path 49, and the lower intake path 50 is connected. Then, the return path 45, the upper intake path 48, the intermediate intake path 49, and the lower intake path 50 pass through the heat exchanger 44 for remedy at a plurality of positions in the upper, intermediate and lower portions of the hot water tank 17. A plurality of intake paths 52 for returning the hot water is formed.

  The take-out path 31, the plurality of take-in paths 52 and the switching valve 47 form a memorial circuit 53 as a heat load circuit.

  In addition, the memorial heat exchanger 44 and the bathtub 14 are connected by a circulation path 54 for the bathtub. The circulation path 54 for the bathtub includes a return pipe 55 that takes in the bathtub water of the bathtub 14 and guides it to the heat exchanger 44 for remedy, and a forward pipe 56 that guides the bathtub water that has passed through the heat exchanger 44 for remedy to the bathtub 14. Have. The return pipe 55 includes a thermistor 57 for detecting the temperature of the bathtub water taken from the bathtub 14, a pressure sensor 58 for detecting the water level of the bathtub 14, a switching valve 59 for switching the flow path when automatically filling the bathtub 14, A bath circulation pump 60 for circulating the bath water and a flow switch 61 for detecting the bath water circulation are provided. The forward pipe 56 is provided with a thermistor 62 that detects the temperature of bathtub water introduced into the bathtub 14.

  The switching valve 59 is connected to a hot water supply passage 41 for the bathtub, and hot water supplied from the hot water supply passage 41 for the bathtub can be supplied to the bathtub 14 through one pipe of the return pipe 55 or two pipes of the return pipe 55 and the forward pipe 56. It has become.

  In addition, a relief valve 65 that releases excess pressure during boiling is connected to the upper outlet passage 25 of the hot water storage tank 17, and this relief valve 65 is connected to a drainage passage 66. The lower part of the hot water storage tank 17 and the drainage path 66 are connected via a drain valve 67 that drains the water in the hot water storage tank 17.

  Further, the hot water storage tank 17 side and the outdoor unit 13 are connected by a boiling circuit 70. This boiling circuit 70 includes a boiling extraction path 71 that connects the lower part of the hot water storage tank 17 and the inlet side of the outdoor unit 13, and a boiling intake path that connects the outlet side of the outdoor unit 13 and the hot water storage tank 17. Has 72. The boiling intake path 72 is connected to the return path 45 of the tracking circuit 53 and shares the switching valve 47, the upper intake path 48, the intermediate intake path 49, and the lower intake path 50. Then, the connection to the outlet side of the outdoor unit 13 is switched by the switching valve 47 to any one of the upper intake path 48, the intermediate part intake path 49, and the lower intake path 50.

  Further, the outdoor unit 13 is provided with a heat pump unit 75 as a boiling means for boiling hot water. The heat pump unit 75 has a refrigerant circuit including a compressor, a boiling heat exchanger 76 that functions as a condenser, an expansion valve, an evaporator, and the like. A boiling circuit 70 is connected to the boiling heat exchanger 76 of the heat pump unit 75. On the upstream side of the boiling heat exchanger 76 of the heat pump unit 75, the boiling circulation pump 77 for circulating the water below the hot water storage tank 17 from the boiling extraction path 71 side to the boiling intake path 72 side. Is arranged.

  The hot water supply device 11 includes a control unit 81 that controls the hot water supply device 11. The controller 81 detects the temperature of the hot water in the hot water storage tank 17 near the upper, middle and lower positions of the hot water storage tank 17 to which the intake path 52 is connected based on the detection of the thermistors 18a to 18f. It is determined whether the temperature is higher than the usable temperature, and the switching valve 47 is switched so as to switch to the intake path 52 for returning the hot water that has passed through the heat exchanger 44 for reheating to the position of the hot water storage tank 17 that is determined to be higher than the temperature that can be used for hot water supply. It has a function to control. More specifically, if the temperature of the hot water near the lower position of the hot water tank 17 is higher than the temperature that can be used for hot water supply, the lower intake that returns the hot water that has passed through the heat exchanger 44 for reheating to the lower part of the hot water tank 17 The switching valve 47 is controlled so as to switch to the path 50, and the temperature of the hot water near the lower position of the hot water tank 17 is lower than the temperature usable for hot water supply and the hot water near the intermediate position of the hot water tank 17 If the temperature is higher than the temperature that can be used for hot water supply, the switching valve 47 is controlled so as to switch to the intermediate portion intake path 49 for returning the hot water that has passed through the heat exchanger 44 to the intermediate portion of the hot water storage tank 17, If the temperature of the hot water near the intermediate position of the hot water storage tank 17 is lower than the temperature that can be used for hot water supply, switch to the upper intake path 48 that returns the hot water that has passed through the heat exchanger 44 for hot water to the upper part of the hot water storage tank 17. In this way, the switching valve 47 is controlled.

  Next, the operation of the present embodiment will be described.

  First, the hot water storage operation of the hot water storage tank 17 will be described.

  The heat pump unit 75 and the boiling circulation pump 77 of the outdoor unit 13 are operated as a specific boiling time zone, for example, in the nighttime zone of the hourly lighting system. By the operation of the boiling circulation pump 77, the water in the lower part of the hot water storage tank 17 is taken out from the boiling extraction path 71 and sent to the heat pump unit 75, and the water boiled up by the heat pump unit 75 is heated to the boiling intake path 72. To the hot water storage tank 17.

  When the temperature of the hot water discharged from the heat pump unit 75 of the outdoor unit 13 is low, the switching valve 47 switches to the lower intake path 50 to return the low temperature hot water to the lower part of the hot water tank 17, and the temperature of the hot water in the upper part of the hot water tank 17 Prevent decline. In addition, when the temperature of the hot water boiled by the heat pump unit 75 of the outdoor unit 13 is equal to or higher than the target boiling temperature, the switching valve 47 switches to the upper intake path 48, and the upper part of the hot water storage tank 17 is equal to or higher than the target boiling temperature. Send hot water and store hot water. Thereby, low temperature hot water is not stored in the upper part of the hot water storage tank 17, and the hot water storage temperature can be increased.

  Next, the hot water supply operation will be described.

  By opening a hot water tap or the like disposed on the downstream side of the hot water supply path 38, the hot water in the hot water storage tank 17 is pushed out by the supply water pressure, and through the upper outlet path 25, the intermediate part outlet path 26, the regulating valve 28 and the hot water path 29. The hot water taken out from the hot water storage tank 17 and the water supplied from the water supply path 20 are mixed by the hot water mixing valve 34 to obtain hot water having a predetermined hot water supply temperature, and this hot water is supplied from the hot water supply passage 38. The hot water taken out to the hot water supply passage 29 is adjusted by adjusting the mixing ratio between the hot water in the upper portion of the hot water storage tank 17 taken out from the upper take-out passage 25 and the hot water in the intermediate portion of the hot water storage tank 17 taken out from the intermediate take-out passage 26 by the adjusting valve 28. Take out.

  Next, use of the bathtub 14 will be described.

  When filling the bathtub 14 with hot water, the hot water in the hot water storage tank 17 is pushed out by the water supply pressure by opening the water supply solenoid valve of the hopper 42, and the upper outlet path 25, the intermediate outlet path 26, the regulating valve 28 and the hot water path The hot water taken out from the hot water storage tank 17 through the water 29 and the water supplied from the water supply path 20 are mixed by the mixing valve 35 for the bathtub to obtain hot water at a preset temperature, and this hot water is supplied. Hot water is supplied to the bathtub 14 through the bathtub circulation path 54 constituting a part of the bathtub hot water supply path 41. When filling the bathtub 14 with hot water, by switching the hot water to flow through the return pipe 55 and the forward pipe 56 with the switching valve 59, a predetermined amount of hot water can be quickly supplied and filled. When filling the bathtub 14 with hot water, the switching valve 59 is switched so that hot water flows only to one pipe of the outgoing pipe 56, and hot water is supplied while monitoring the water level with the pressure sensor 58 of the return pipe 55. The hot water can be filled so that the water level exactly matches the set water level. In addition, the hot water taken out to the hot water supply passage 29 is adjusted by the adjustment valve 28 to adjust the mixing ratio of the hot water in the upper portion of the hot water storage tank 17 taken out from the upper take-out passage 25 and the hot water in the intermediate portion of the hot water storage tank 17 taken out from the intermediate portion take-out passage 26. And take it out.

  Then, after filling the bathtub 14, the bathtub circulation pump 60 is operated every predetermined time to circulate the bathtub water in the bathtub 14 in the circulation path 54 for the bathtub, and the temperature of the bathtub water is detected by the thermistor 57. Then, it is monitored whether there is a need for heat insulation, that is, a chasing action.

  In addition, when the temperature of the bathtub water falls below the set temperature, it automatically retreats, and it can also be remediated by manual operation such as a bathtub remote controller.

  In the reheating operation, as shown by the black display of the piping path in FIG. 1 and the arrow, first, the bathtub circulation pump 60 is operated, and the bathtub water is taken into the bathtub circulation path 54 to perform heat exchange for reheating. Circulate in vessel 44. In that state, the hot water in the hot water storage tank 17 is taken out through the upper take-out path 25, the intermediate part take-out path 26, the regulating valve 28, and the hot water supply path 29 (take-out path 31) by operating the circulation pump 46 for memory. It is sent to the heat exchanger for remedy 44, and heat is exchanged between the hot water from the hot water storage tank 17 and the bathtub water from the bathtub 14 by the heat exchanger for remedy 44. The hot water temperature in the bathtub 14 is raised. Note that the hot water taken out to the hot water supply path 29 (take-out path 31) is adjusted with the hot water in the upper part of the hot water storage tank 17 taken out from the upper take-out path 25 and the hot water in the middle part of the hot water storage tank 17 taken out from the intermediate part take-out path 26. Adjust and adjust the mixing ratio.

  Further, the hot water from the hot water storage tank 17 whose temperature has dropped after passing through the heat exchanger for remnant 44 is a return path 45, a switching valve 47, an upper intake path 48, an intermediate intake path 49, and a lower intake path 50. It returns to the hot water storage tank 17 through any one of these.

  At this time, based on the detection of the thermistors 18a to 18f of the hot water storage tank 17, the upper, intermediate and lower portions of the hot water storage tank 17 to which the upper intake path 48, the intermediate intake path 49 and the lower intake path 50 are connected are connected. It is determined whether the temperature of the hot water in the hot water storage tank 17 near each position is higher than the temperature that can be used for hot water supply. The switching valve 47 is switched so as to return the hot water that has passed.

  That is, as condition 1, when the temperature of the hot water detected by the thermistor 18f is higher than the temperature that can be used for hot water supply (approximately 45 ° C.) near the lower part of the hot water storage tank 17 to which the lower intake path 50 is connected, The switching valve 47 switches to the lower intake path 50, and the hot water that has passed through the heat exchanger for remedy 44 is returned to the lower part of the hot water storage tank 17.

  As condition 2, in the vicinity of the lower part of the hot water storage tank 17 to which the lower intake path 50 is connected, the temperature of the hot water detected by the thermistor 18f is lower than the temperature that can be used for hot water supply (approximately 45 ° C.) When the temperature of the hot water detected by the thermistor 18e at the 4/5 position is higher than the temperature that can be used for hot water supply (approximately 45 ° C) in the vicinity of the middle part of the hot water storage tank 17 to which the inlet path 49 is connected, the switching valve 47 is switched to the intermediate portion intake path 49, and the hot water that has passed through the heat exchanger for remedy 44 is returned to the intermediate portion of the hot water storage tank 17.

  Condition 3 is that the temperature of the hot water detected by the thermistor 18e at the 4/5 position is near the temperature (about 45 ° C) that can be used for hot water supply in the vicinity of the intermediate part of the hot water storage tank 17 to which the intermediate part intake path 49 is connected. When the temperature is low, the switching valve 47 switches to the upper intake path 48 to return the hot water that has passed through the reheating heat exchanger 44 to the upper portion of the hot water storage tank 17.

  As described above, when the hot water whose temperature has decreased after passing through the heat exchanger 44 for return is returned to the hot water storage tank 17, the upper, middle and lower parts of the hot water storage tank 17 to which the intake paths 48, 49, 50 are connected. It is determined whether the temperature of the hot water in the hot water storage tank 17 in the vicinity of each position is higher than the temperature that can be used for hot water supply. In order to switch the hot water that has passed through one of the intake paths 48, 49, 50 so as to return the hot water, the amount of heat of the hot water that has passed through the heat exchanger 44 for reheating is used as hot water for the hot water storage tank 17. Return to the area of hot water that can be used, no longer return to the area of water below the hot water storage tank 17 that can not be used for hot water supply, it can be used effectively for hot water supply without wasting the amount of hot water, much hot water that can be used for hot water supply it can.

  Moreover, even if the hot water in the hot water storage tank 17 is used for hot water supply and the region where the temperature of the hot water in the hot water storage tank 17 is higher than the temperature that can be used for hot water supply rises, the lower part of the hot water storage tank 17, the middle part and Since the hot water that has passed through the heat exchanger for reheating 44 can be returned in the order of the top, the hot water that has passed through the heat exchanger for reheating 44 is surely placed at a hot water position above the temperature that can be used for hot water supply in the hot water storage tank 17. Can be returned.

  Further, even if the temperature of the hot water after passing through the heat exchanger 44 for reheating is about 40 ° C. and lower than the temperature that can be used for hot water supply as it is, the hot water after the reheating is 40 ° C. Therefore, it is possible to return the hot water after reheating to an area above the temperature that can be used for hot water supply in the hot water storage tank 17, without wasting the heat of the hot water after reheating. The hot water stored in the hot water storage tank 17 can be raised above the temperature that can be used for hot water supply by mixing it with hot water that is higher than the temperature that can be used for hot water supply in the hot water storage tank 17. However, the amount of hot water that can be used for hot water supply can be increased.

  In addition, by providing an upper intake passage 48 at the upper part of the hot water storage tank 17, even if there is almost no remaining hot water in the hot water storage tank 17, the amount of heat of the hot water after passing through the heat exchanger 44 for reheating is stored. It is possible to match the hot water in the upper part of the tank 17 and leave as much hot water in the hot water storage tank 17 as possible at a temperature higher than the temperature that can be used for hot water supply.

  In addition, the water supplied from the hot water storage tank 17 to the lower part of the hot water storage tank 17 by the hot water supply is not mixed with the hot water after passing through the heat exchanger 44 for reheating. Since the area of the mixed layer of hot water and water can be kept to a minimum size, it is possible to prevent boiling of the medium-temperature water by the heat pump unit 75 and prevent deterioration of the boiling efficiency (COP). it can.

  In addition, the heating intake path 72 of the heating circuit 70 by the heat pump unit 75 is shared with the intake paths 48, 49, 50 and the switching valve 47 of the memory circuit 53, so that the heating operation and freezing prevention operation are performed. Sometimes the hot water that has passed through the heat pump unit 75 can be returned to the hot water storage tank 17 by switching to any one of the intake paths 48, 49, 50, so the water channel configuration is simpler than in the case of separate configuration And cost can be reduced. With regard to the freeze prevention operation, when the boiling circulation pump 77 is operated to circulate hot water between the bottom of the hot water storage tank 17 to prevent freezing of the piping of the boiling circuit 70, the lower valve is removed by the switching valve 47. By switching to the inlet path 50, the low-temperature water in the pipe can be returned to the lower part of the hot water storage tank 17, and the switching valve 47 can be shared, and a dedicated switching valve for preventing freezing can be omitted.

  In addition, although the determination temperature as a temperature usable for hot water supply is assumed to be 45 ° C., in addition to the case where the determination temperature is fixed to one as described above, the water channel configuration, the capacity of the heat exchanger 44 for reheating, the outside air In any case where the judgment temperature is varied according to the temperature, the feed water temperature, etc., and the water channel is switched based on the varied judgment temperature, the amount of heat of the hot water after passing through the heat exchanger for reheating 44 is calculated. You can avoid wasting it.

  In addition, although each intake path 48, 49, 50 is connected to the upper, middle and lower parts of the hot water tank 17, one is connected to the intermediate part intake path 49 connected to the intermediate part of the hot water tank 17. Alternatively, the hot water storage tank 17 may be connected to a plurality of different positions in the vertical direction of the intermediate portion.

  Further, as shown in FIG. 2, the boiling intake path 72 of the boiling circuit 70 may be connected to the upper intake path 48 without passing through the switching valve 47.

  Note that the heat load for exchanging heat with the hot water in the hot water storage tank 17 by the heat exchanger is not limited to the reheating of the bathtub water in the bathtub 14, but can also be applied to hot water heating.

It is a lineblock diagram of the hot-water supply device which shows a 1st embodiment of the present invention. It is a block diagram of the hot water supply apparatus which shows the 2nd Embodiment of this invention.

Explanation of symbols

11 Water heater
17 Hot water storage tank
18a-18f Thermistor as temperature detection means
31 Extraction route
44 Relief heat exchanger as a heat exchanger
47 Switching valve as switching means
52 Intake route
53 Remembrance circuit as thermal load circuit
70 Boiling circuit
71 Boiling extraction route
72 Boiling intake route
75 Heat pump unit
81 Control unit

Claims (3)

A hot water storage tank for storing hot water,
A heat exchanger disposed outside the hot water storage tank, for exchanging the hot water in the hot water storage tank with the heat load side;
An extraction path for taking out hot water in the hot water storage tank and leading it to the heat exchanger, a plurality of intake paths capable of returning the hot water that has passed through the heat exchanger to the upper part, the middle part, and the lower part of the hot water storage tank, respectively And a thermal load circuit having switching means for switching to any one of the plurality of intake paths,
Temperature detecting means for detecting the temperature of hot water in the hot water storage tank in the vicinity of the upper, middle and lower positions of the hot water storage tank to which at least the intake path is connected;
Whether the temperature of the hot water in the hot water storage tank near the upper, middle, and lower positions of the hot water storage tank to which the intake path is connected based on the detection by the temperature detecting means is higher than the temperature that can be used for hot water supply And a controller that switches the intake path with the switching means so as to return the hot water that has passed through the heat exchanger to a position of the hot water storage tank that is determined to be higher than a temperature that can be used for hot water supply. A water heater characterized by that. The control unit
If the temperature of the hot water near the lower position of the hot water storage tank is higher than the temperature that can be used for hot water supply, the switching means is controlled so as to switch to the intake path for returning the hot water that has passed through the heat exchanger to the lower part of the hot water storage tank,
If the temperature of the hot water near the lower position of the hot water storage tank is lower than the temperature usable for hot water supply and the temperature of the hot water near the intermediate position of the hot water storage tank is higher than the temperature usable for hot water supply, the hot water storage tank Controlling the switching means to switch to an intake path for returning the hot water that has passed through the heat exchanger to an intermediate portion;
If the temperature of the hot water near the position of the intermediate portion of the hot water storage tank is lower than the temperature that can be used for hot water supply, the switching means is configured to switch to the intake path for returning the hot water that has passed through the heat exchanger to the upper part of the hot water storage tank. The hot water supply apparatus according to claim 1, wherein: A heat pump unit for boiling water,
A boiling circuit having a boiling extraction path for taking out water from the hot water storage tank and leading it to the heat pump unit, and a boiling intake path for returning hot water boiled through the heat pump unit to the hot water storage tank; Comprising
The boiling intake path of the boiling circuit is shared with the intake path and switching means of the heat load circuit, and the hot water that has passed through the heat pump unit by switching to any one of the multiple intake paths is used. It returns to the said hot water storage tank. The hot water supply apparatus of Claim 1 or 2 characterized by the above-mentioned.

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