JP2007024458A - Hot-water supplier - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To realize a technique capable of suppressing thermal efficiency from lowering, in a hot-water supplier capable of sterilizing water supplied from a storage tank. <P>SOLUTION: The hot-water supplier consists of a hot-water supply route 104, a cold water route 106, a water quantity adjusting means 107, a hot water quantity detecting means 108 and a controller 110. Through the hot-water supply route 104, tap water 112 is supplied out to a hot-water supply position 114 via the storage tank 102 and a burner type heat exchanger 115. The cold water route 106 makes the tap water 112 merge between the burner type heat exchanger 115 and the hot-water supply position 114. The water quantity adjusting means 107 adjusts the quantity of water passing through the cold water route 106. The hot water quantity detecting means 108 detects the quantity of water supplied to the hot-water supply position 114. At the time of sterilizing, the controller 110 burns the burner type heat exchanger 115 more strongly than when it is not sterilizing and when integrated value of the water quantity detected by the hot water quantity detecting means 108 reaches a predetermined value after starting sterilization, sterilization is finished. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a hot water supply apparatus. In particular, the present invention relates to a hot water supply apparatus that can sterilize hot water stored in a hot water storage tank before hot water supply.

There is known a hot water supply apparatus that supplies hot water stored in a hot water storage tank to a hot water supply location. If the hot water stored in the hot water storage tank is not consumed for a long time, the temperature of the hot water stored in the hot water decreases, and various bacteria such as Legionella bacteria may propagate in the hot water. In that case, the hot water stored in the hot water storage tank must be sterilized and then supplied with hot water (hereinafter, “hot water” and “cold water” are collectively referred to as “water” without distinction).
Patent Document 1 discloses a hot water supply device including a hot water storage tank and a burner type heat exchanger. When the temperature of the water stored in the hot water storage tank drops, the water sent from the hot water storage tank is heated by a burner type heat exchanger and then supplied to the hot water supply location. When the temperature of the water stored in the hot water storage tank is high, the burner heat exchanger is not operated. When the hot water storage tank is sterilized, a flow path that makes a circuit between the hot water storage tank and the burner heat exchanger is formed. The water sent out from the hot water storage tank passes through the burner heat exchanger and the temperature rises. The water whose temperature has risen through the burner heat exchanger returns to the hot water storage tank. By repeating such circulation, the water in the hot water storage tank becomes hot and the hot water storage tank is sterilized.

JP 2004-263912 A

The hot water supply apparatus of Patent Document 1 is based on meeting the hot water supply request with the hot water stored, and stores hot water in order to increase the amount of hot water stored. It is normal to store hot water in a hot water storage tank to such an extent that the propagation of various germs can be suppressed. Burner heat exchangers are intended to operate in exceptional cases where hot water storage is insufficient. Even when hot water is stored, if the hot water is not supplied for a long period of time, the temperature of the water in the tank will drop, and there is a possibility that germs will propagate. In this case, it sterilizes by performing the said heating operation using a burner type heat exchanger, and returning to the normal state which stores hot water in a tank.
The hot water storage system that stores hot water in the hot water storage tank is based on meeting the hot water supply demand using the hot water stored in the hot water storage tank. It is necessary to store a large amount of hot water, and a large space is required for installing the tank. Therefore, the hot water storage tank needs high heat insulation performance.
Therefore, it has been attempted to develop a hot water supply apparatus that suppresses the amount of stored hot water on the premise that a burner type heat exchanger is used when the amount of stored hot water is insufficient. It is a system that uses a burner type heat exchanger while having a hot water storage tank, and it seems that the advantages of the hot water storage type hot water supply device cannot be obtained. However, since the amount of hot water stored is small, a small tank is sufficient, and restrictions on installation space are eased. Moreover, since the amount of stored hot water is small, it is sufficient to store low-temperature water, and high heat insulation performance is not required. Moreover, since there is a relatively small amount of hot water supply request, the advantage of the hot water storage type hot water supply device can be enjoyed even if the tank capacity is small. It is expected that the hot water storage type hot water supply device that suppresses the amount of hot water storage and uses a burner type heat exchanger when the amount of hot water storage is insufficient is expected to have high practical value.
This type of hot water storage type hot water supply device normally stores water at low temperature (low temperature to the extent that germs can propagate), and if no hot water is supplied for a long time, germs can propagate in the tank. There is sex. However, the sterilization technique of Patent Document 1 is not compatible with this type of hot water storage type hot water supply apparatus. The sterilization technique of Patent Document 1 is a system in which water in a tank is sterilized by heating to a high temperature, and is not compatible with a hot water storage type hot water supply apparatus that normally stores low temperature water.
The present invention provides a sterilization technique suitable for a hot water supply apparatus that normally stores hot low-temperature water.

The hot water supply apparatus of the present invention will be described with reference to FIGS. 9 to 13 schematically illustrating the concept.
The hot water supply apparatus of the present invention can sterilize the water stored in the hot water storage tank and then send the hot water to the hot water supply location. As shown in FIG. 9, the hot water supply apparatus includes a hot water supply path 104, a cold water path 106, a water amount adjustment means 107, a hot water supply amount detection means 108, and a controller 110. Hot water supply path 104 sends tap water 112 to hot water supply location 114 via hot water storage tank 102 and burner type heat exchanger 115. The cold water path 106 joins the tap water 112 with the water sent out from the burner heat exchanger 115 between the burner heat exchanger 115 and the hot water supply point 114. The water amount adjusting means 107 adjusts the amount of water passing through the cold water path 106. The hot water supply amount detection means 108 detects the amount of water supplied to the hot water supply location 114. The controller 110 is connected to a burner heat exchanger 115, a water amount adjusting means 107, and a hot water supply amount detecting means 108. The controller 110 burns the burner heat exchanger 115 more strongly during the sterilization process than during the non-sterilization process, and the integrated value of the amount of water detected by the hot water supply amount detection means 108 after the start of the sterilization process by the burner type heat exchanger 115. When the value reaches a predetermined value, the sterilization process by the burner heat exchanger is finished.
This hot water supply apparatus burns the burner heat exchanger 115 more strongly during the sterilization process than during the non-sterilization process. By burning the burner heat exchanger 115 strongly, the temperature of the water passing through the burner heat exchanger 115 is increased. For this reason, the water which passes the burner type heat exchanger 115 is sterilized. The tap water that has passed through the cold water passage 106 joins the water sent from the burner heat exchanger 115 and sterilized. By adjusting the amount of water passing through the cold water path 106 by the water amount adjusting means 107, the water whose temperature is appropriately adjusted is sent out to the hot water supply location 114. The amount of heat applied by the burner heat exchanger 115 is effectively used for both sterilization and hot water supply.
According to this hot water supply device, water supplied from the hot water storage tank 102 to the hot water supply location 114 can be sterilized without heating the water in the hot water storage tank 102 to a high temperature. It can be reasonably adapted to a hot water supply apparatus that normally stores hot water of low temperature (low temperature to the extent that various bacteria can propagate). In the technique of Patent Document 1, when there is a hot water request while heating the hot water storage tank 102 to sterilize, hot water cannot be discharged until the hot water storage tank 102 is heated. According to the hot water supply apparatus of the present invention, it is not necessary to heat the entire hot water storage tank 102, and it is possible to respond to a hot water request in a timely manner.
This hot water supply device ends the sterilization process when the integrated value of the amount of water detected by the hot water supply amount detection means 108 after the start of the sterilization process reaches a predetermined value. The sterilization process can be terminated at a timing when all the water that has entered the hot water storage tank 102 at the start of the sterilization process is sterilized.
The hot water supply amount detection means 108 may be at the position A in FIG. If it is in the position A, the amount of hot water discharged from the hot water storage tank 102 is directly detected. If the flow rate passing through A is known, the mixing ratio of hot water and cold water can be determined from the relationship between the hot water temperature, the cold water temperature, and the hot water supply temperature, and the hot water supply amount can be determined. If it is in the position of B, the hot water supply amount is directly detected. If the flow rate passing through B is known, the mixing ratio of hot water and cold water can be found from the relationship between the hot water temperature, cold water temperature, and hot water supply temperature, and the amount of hot water discharged from the hot water storage tank 102 can be found.
By detecting the flow rate at the A position or the B position, all the water that has entered the hot water storage tank 102 at the start of the sterilization process is sent out, and then the timing at which the sterilization process is unnecessary is specified. be able to.

As shown in FIG. 10, temperature detecting means 118 may be provided instead of the hot water supply amount detecting means. The temperature detection means 118 detects the temperature of the water before being sent out from the hot water storage tank 102 and flowing into the burner type heat exchanger 115. In the case of the hot water storage type hot water supply apparatus of FIG. 10, the controller 110 burns the burner heat exchanger 115 more strongly during the sterilization process than during the non-sterilization process, and when the temperature detection means 118 detects a predetermined temperature, The sterilization process by the heat exchanger is finished.
According to this hot water supply device, water supplied from the hot water storage tank 102 to the hot water supply location 114 can be sterilized without heating the water in the hot water storage tank 102 to a high temperature. Moreover, according to this hot water supply apparatus, it is not necessary to heat the whole hot water storage tank 102, and it can respond to a hot water request | requirement timely.
When the water stored in the hot water storage tank 102 is sent out, the tap water 112 enters the hot water storage tank 102 by the amount sent out. When all the water that has entered the hot water storage tank 102 at the start of the sterilization process is sent out, the temperature detection means 118 detects the temperature of the tap water 112. This hot water supply device ends the sterilization process when the temperature detecting means 118 detects a predetermined temperature. Therefore, it becomes possible to end the sterilization process at the timing when all of the water stored in the hot water storage tank 102 at the time of the sterilization start process is sent out and sterilized.

As shown in FIG. 11, the hot water supply apparatus preferably includes a heating path 125, an opening / closing means 121, a pump 122, a heating means 123, and a switching means 120. The heating path 125 branches from the flow path 126 that leads the tap water 112 to the hot water storage tank 102, passes through the heating means 123, and joins the flow path 127 that connects the hot water storage tank 102 and the burner type heat exchanger 115. The opening / closing means 121 can open and close the heating path 125. The pump 122 returns the water stored in the hot water storage tank 102 to the hot water storage tank 102 via the heating path 125. The switching unit 120 enables one or both of the hot water supply path 104 and the heating path 125. The controller 110 closes the opening / closing means 121 when executing the sterilization process in a state where the hot water supply path 104 is enabled by the switching means 120.
When the opening / closing means 121 is closed, the tap water does not flow into the heating path 125, and a lot of water is sent out from the hot water storage tank 102. Therefore, the sterilization operation can be finished earlier.
The heating means 123 and the heating path 125 can heat the water stored in the hot water storage tank 102, and can also heat the water sent to the burner type heat exchanger 115.

In the above hot water supply apparatus, as shown in FIG. 12, it has a sterilization path 140 for returning the water stored in the hot water storage tank 102 to the hot water storage tank 102 through the burner type heat exchanger 115 by the pump 122. Is preferred. In that case, the controller 110 enables any one of the hot water supply path 104, the heating path 125, and the sterilization path 140 by the switching unit 120, and the first predetermined period has elapsed since the start of the sterilization process by the burner heat exchanger. Even if the integrated value of the hot water flow rate detected by the hot water supply amount detection means 108 does not reach the predetermined value, the sterilization path 140 is validated.
In the sterilization process, when the burner type heat exchanger 115 is burned more strongly than the non-sterilization process and the water sent to the hot water supply area 114 is sterilized, the sterilization process is not performed unless the water is consumed at the hot water supply area 114. For this reason, if the consumption of water at the hot water supply point 114 is small, the water stored in the hot water storage tank 102 at the start of the sterilization process by the burner type heat exchanger may remain in the hot water storage tank 102 for a long period of time. is there. If the integrated value of the hot water supply flow rate detected by the hot water supply amount detection means 108 does not reach the predetermined value even after the first predetermined period has elapsed since the start of the sterilization process, the hot water supply device described above makes the sterilization path 140 effective. To do. By enabling the sterilization path 140, the water sent out from the hot water storage tank 102 is heated by the burner heat exchanger 115 and circulated back to the hot water storage tank 102. By this circulation, the water in the hot water storage tank 102 becomes high temperature. The water in the hot water storage tank 102 is sterilized by reaching a high temperature.
This technical element is nothing but the technique of Patent Document 1. Inherently, it is not compatible with the technology of storing hot water of low temperature. In the present invention, the entire hot water storage tank is heated and sterilized only in exceptional cases where hot water is not supplied over a long period of time.

As shown in FIG. 13, a burner heat exchanger 115 heats water with the combustion heat of the burner, and a sensible heat exchanger 132 that heats the water with the latent heat of condensation of water vapor contained in the combustion gas of the burner. It is preferable to provide the exchanger 133. In that case, a latent heat exchanger 133 is interposed between the branching point 135 to the heating path 125 and the hot water storage tank 102, and it appears between the junction point 136 from the heating path 125 and the junction point 138 from the cold water path 106. A heat exchanger 132 is interposed.
The latent heat exchanger 133 is highly efficient when the temperature of the passing water is low. This is because if the temperature of the passing water is low, a large amount of water vapor contained in the combustion gas is condensed. In the hot water supply apparatus described above, the latent heat exchanger 133 is interposed between the branch point 135 to the heating path 125 and the hot water storage tank 102. For this reason, tap water with a low temperature passes through the latent heat exchanger 133. Alternatively, water having a low temperature stored in the bottom of the hot water storage tank 102 passes through the latent heat exchanger 133. The efficiency of the latent heat exchanger 133 can be increased.

In the hot water supply apparatus, the heating means 123 is preferably a heat pump.
By employing the heat pump, the thermal efficiency of the hot water supply device can be increased.

In the hot water supply apparatus described above, the controller 110 preferably starts the sterilization process by the burner type heat exchanger when the second predetermined period has elapsed after the sterilization process by the burner type heat exchanger has been completed.
When a long period of time elapses after the sterilization process is finished, there is a high possibility that many germs have propagated in the water stored in the hot water storage tank 102. This hot water supply device starts the sterilization process by the burner type heat exchanger when the second predetermined period has elapsed after the sterilization process by the burner type heat exchanger has been completed.

  ADVANTAGE OF THE INVENTION According to this invention, even if it does not heat all the water in a hot water storage tank to high temperature, the water sent to a hot-water supply location from a hot water storage tank can be disinfected. It can be reasonably adapted to a hot water supply apparatus that normally stores hot water at low temperature (low enough to allow bacteria to propagate). Moreover, according to the hot water supply apparatus of the present invention, it is not necessary to heat the entire hot water storage tank, and it is possible to respond to a hot water request in a timely manner.

The main features of the embodiments described later will be described.
(1) The hot water supply apparatus includes a heat pump, a hot water storage tank, a burner unit, a flow path connecting them, a sensor, a three-way valve, a flow rate adjustment valve, a pump, a controller, and a remote controller interposed in the flow path.
(2) The heat pump has an outdoor air heat exchanger, a hot water supply heat exchanger, a compressor, a pressure reducing valve, and a flow path that goes around them. The heat medium flows into the outside air heat exchanger. The heat medium flowing through the outside air heat exchanger absorbs heat from outside air. The temperature of the heat medium that has flowed out of the outside heat exchanger is increased by being compressed by the compressor. The hot water supply heat exchanger is provided with a heat medium passage and a water passage. The heat medium compressed by the compressor flows into the heat medium flow path. The heat medium flowing through the heat medium flow path heats the water flowing through the water flow path. The temperature of the heat medium that has flowed out of the heat medium flow path of the hot water supply heat exchanger is reduced by expansion by the pressure reducing valve. The heat medium whose temperature has decreased returns to the outside air heat exchanger and absorbs heat from the outside air.
(3) The burner unit includes a sensible heat exchanger, a latent heat exchanger, and a burner. The controller controls the heat pump, the three-way valve, and the flow rate adjustment valve based on a signal input from a sensor or the like. The remote controller is connected to the controller and is used by the user to set the hot water supply required temperature and the like.
(4) When storing hot water in the hot water storage tank, the heat pump is operated. Do not burn the burner. At this time, when the pump operates, water circulates along a route that passes from the hot water storage tank through the latent heat exchanger and the hot water supply heat exchanger and returns to the hot water storage tank. Water passing through the hot water supply heat exchanger is heated by the heat medium passing through the heat medium flow path, and hot water is stored in the hot water storage tank.
(5) When the temperature of the hot water stored in the hot water storage tank is higher than the required hot water supply temperature, the heat pump is operated. Do not burn the burner. In this case, the tap water supplied to the hot water supply device is sent to the lower part of the hot water storage tank via the latent heat exchanger. When water is sent to the lower part of the hot water storage tank, the hot water stored from the upper part of the hot water storage tank is sent out. The water sent out from the hot water storage tank passes through the sensible heat exchanger and then is supplied to a hot water tap or the like. In addition, the tap water supplied to the hot water supply apparatus joins the water sent from the hot water storage tank after the temperature rises by passing through the water flow path of the hot water supply heat exchanger.
(6) When the temperature of the hot water stored in the hot water storage tank is lower than the required hot water supply temperature, the heat pump is operated and the burner is burned. The tap water supplied to the hot water supply apparatus passes through the latent heat exchanger, and thereby recovers the condensation latent heat of the water vapor contained in the combustion gas and rises in temperature. The water whose temperature has risen through the latent heat exchanger is sent to the lower part of the hot water storage tank. When water is sent to the lower part of the hot water storage tank, the water is sent out from the upper part of the hot water storage tank. The water sent out from the hot water storage tank passes through the sensible heat exchanger. The water that has passed through the sensible heat exchanger is heated by the combustion gas of the burner, and the temperature further rises. The water heated by the sensible heat exchanger is supplied to a hot water tap or the like. In addition, the tap water supplied to the hot water supply apparatus joins the water sent from the hot water storage tank after the temperature rises by passing through the water flow path of the hot water supply heat exchanger.
(7) Two sterilization modes (first sterilization mode and second sterilization mode) can be executed. The first sterilization mode and the second sterilization mode are executed by the controller processing the sterilization process.
The first sterilization mode is started when a first predetermined period elapses after the previous sterilization process is completed. In the first sterilization mode, the heat pump is stopped. The tap water passes through the latent heat exchanger, the hot water storage tank, and the sensible heat exchanger. In the first sterilization mode, the burner is burned strongly. By burning the burner strongly, the temperature of the water flowing out of the sensible heat exchanger becomes high, and the water sent out from the hot water storage tank is sterilized. Tap water is mixed with water that has flowed out of the sensible heat exchanger, and water at a desired temperature is supplied to a hot water tap or the like.
(8) The second sterilization mode is executed when the second predetermined period has elapsed since the start of the first sterilization mode. In the second sterilization mode, the heat pump is operated and the burner is burned. In this case, when the pump operates, water circulates from the hot water storage tank through a latent heat exchanger, a hot water supply heat exchanger, and a sensible heat exchanger, and then returns to the hot water storage tank. The circulating water becomes high temperature by passing through the latent heat exchanger, the hot water supply heat exchanger, and the sensible heat exchanger. The hot water storage tank is sterilized by the hot water.
(9) If there is a hot water supply request during execution of the second sterilization mode, the heat pump is stopped. The burner continues to operate. The tap water supplied to the hot water supply device passes through the sensible heat exchanger. The water passing through the sensible heat exchanger is heated by the burner combustion gas and sterilized, and then supplied to a hot water tap or the like.

One embodiment of the hot water supply apparatus of the present invention will be described with reference to the drawings.
As shown in FIG. 1, a hot water supply apparatus 10 includes a heat pump 12, a hot water storage section 45, a burner section 50, a flow path connecting them, a sensor, a three-way valve, a flow rate adjustment valve, a controller 95, a remote controller 96.
The heat pump 12 includes an outside air heat exchanger 20, a blower 21, a hot water supply heat exchanger 24, a circulation forward path 30, a circulation return path 34, a compressor 32, a pressure reducing valve 37, a first sensor 33, a second sensor 40, and a third sensor 41. Have.
The outside air heat exchanger 20 performs heat exchange between the heat medium passing through the inside and the outside air. The blower 21 is provided adjacent to the outside air heat exchanger 20 and has an electric motor 23 and a fan 22. The fan 22 is driven by the electric motor 23 to rotate. When the fan 22 rotates, outside air is blown to the outside air heat exchanger 20. When the outside air is blown, the efficiency of the outside air heat exchanger 20 is improved. As the heat medium, for example, alternative chlorofluorocarbon (hydrofluorocarbon or the like) or carbon dioxide, for example, can be used.

The hot water supply heat exchanger 24 is provided with a heat medium passage 26 and a water passage 27. The circulation forward path 30 connects the outlet 25 of the outside air heat exchanger 20 and the inlet 31 of the heat medium flow path 26 of the hot water supply heat exchanger 24. The compressor 32 and the first sensor 33 are interposed in the circulation outward path 30.
The circulation return path 34 connects the outlet 35 of the heat medium flow path 26 of the hot water supply heat exchanger 24 and the inlet 36 of the outside air heat exchanger 20. The pressure reducing valve 37, the second sensor 40, and the third sensor 41 are interposed in the circulation return path 34.
The compressor 32 compresses the heat medium flowing out of the outside air heat exchanger 20 and sends it to the hot water supply heat exchanger 24. The first sensor 33 detects the temperature of the heat medium that has flowed out of the outside heat exchanger 20. The hot water supply heat exchanger 24 exchanges heat between the heat medium passing through the heat medium flow path 26 and the water passing through the water flow path 27. The water passing through the water flow path 27 is heated by the heat medium passing through the heat medium flow path 26. The second sensor 40 detects the temperature of the heat medium that has flowed out of the hot water supply heat exchanger 24. The pressure reducing valve 37 depressurizes the passing heat medium. The degree to which the pressure reducing valve 37 depressurizes the heat medium is performed by adjusting the opening degree. The third sensor 41 detects the temperature of the heat medium flowing into the outside heat exchanger 20.

The hot water storage section 45 includes a hot water storage tank 46 and a fourth sensor 47. The hot water storage tank 46 is formed in a vertically long shape. The fourth sensor 47 detects the temperature of the water in the hot water storage tank 46.
The burner unit 50 includes a sensible heat exchanger 52, a latent heat exchanger 51, a burner 53, and a burner fan 54. The burner 53 burns gas. The burner fan 54 blows air for combustion to the burner 53.

Tap water is supplied to one end 57 of the first flow path 56. The other end 58 of the first channel 56 is connected in the middle of a second channel 60 (described later). A flow rate sensor 59 is interposed in the first flow path 56. The flow sensor 59 detects the amount of water flowing through the first flow path.
The second flow path 60 connects the relief valve 62 and one end 63 of the latent heat exchanger 51. A first three-way valve 64 is interposed in the second flow path 60. The relief valve 62 opens when the pressure in the second flow path 60 reaches a predetermined value or more, and releases the pressure in the second flow path 60 to the outside. The first three-way valve 64 switches between a state in which the second flow paths 60 are circulated and a state in which the relief flow valve 62 side of the second flow path 60 and the eleventh flow path 94 (described later) are circulated.
The third flow path 66 connects the other end 67 of the latent heat exchanger 51 and the lower end of the hot water storage tank 46. A fifth sensor 68 is interposed in the third flow channel 66. The fifth sensor 68 detects the temperature of the water flowing through the third flow channel 66.

The fourth flow path 70 connects the middle of the second flow path 60 and the inlet 71 of the water flow path 27 of the hot water supply heat exchanger 24. A pump 73 and a first flow rate adjustment valve 72 are interposed in the fourth flow path 70. The pump 73 sucks water on the upstream side (first flow rate adjustment valve 72 side) and sends it out to the downstream side. The first flow rate adjusting valve 72 adjusts the amount of water passing therethrough by changing its opening degree.
The fifth flow path 75 connects the outlet 74 of the water flow path 27 of the hot water supply heat exchanger 24 and the middle of a seventh flow path 78 (described later). A fifth sensor 76 and a second three-way valve 77 are interposed in the fifth flow path 75. The fifth sensor 76 detects the temperature of the water flowing through the fifth flow path 75.
The upstream end 85 of the sixth flow path 84 is connected to the second three-way valve 77. The downstream side of the sixth flow path 84 communicates with a hot water tap and a bath. A sixth sensor 79 is interposed in the sixth flow path 84. The second three-way valve 77 switches between a state in which the fifth flow paths 75 are circulated and a state in which the upstream side of the fifth flow path 75 and the sixth flow path 84 are circulated. The sixth sensor 79 detects the temperature of water flowing through the sixth flow path 84.
The seventh flow path 78 connects the upper end of the hot water storage tank 46 and a third three-way valve 82 (described later). A seventh sensor 80 is interposed in the seventh flow path 78. The seventh sensor 80 detects the temperature of the water flowing through the seventh flow path 78.

The eighth flow path 81 connects the one end 83 of the sensible heat exchanger 52 and the third three-way valve 82. As described above, the sixth flow path 78 is connected to the third three-way valve 82. An eleventh flow path 94 (described later) is also connected to the third three-way valve 82. The third three-way valve 82 switches between a state in which the seventh channel 78 and the eighth channel 81 are circulated and a state in which the eighth channel 81 and the eleventh channel 94 are circulated.
The ninth flow path 86 connects the other end 87 of the sensible heat exchanger 52 and the middle of the sixth flow path 84. An eighth sensor 88 is interposed in the ninth flow path 86. The eighth sensor 88 detects the temperature of the water flowing through the ninth flow path 86.
One end 92 of the tenth channel 90 is connected to the same part as the ninth channel 86 in the middle of the sixth channel 84. The other end 93 of the tenth channel 90 is connected to the same part as the fourth channel 70 in the middle of the second channel 60. A second flow rate adjustment valve 91 is interposed in the tenth flow path 90. The second flow rate adjustment valve 91 adjusts the amount of water flowing through the tenth flow path 90 by changing the opening degree. The eleventh flow path 94 connects the first three-way valve 64 and the third three-way valve 82.

The controller 95 stores a control program. The controller 95 receives an operation signal from the remote controller 96, a detection signal from the flow sensor 59, and detection signals from the sensors 33, 40, 41, 47, 68, 79, 80, and 88. The controller 95 processes these signals with a control program, whereby the blower 21, the compressor 32, the pressure reducing valve 37, the burner 53, the burner fan 54, the three-way valves 64, 77, 82, the pump 73, the flow rate adjusting valve 72, 91 is controlled.
Instead of the heat pump 12, other heating means (for example, a fuel cell) can be used.

The operation of the hot water supply apparatus 10 will be described.
A liquid heat medium flows into the outside air heat exchanger 20 of the heat pump 12 from the circulation return path 34. The heat medium flowing through the outside heat exchanger 20 evaporates by absorbing heat from the outside air, and changes in phase from liquid to gas. The heat medium that has flowed out of the outside air heat exchanger 20 flows through the circulation path 30 and is compressed by the compressor 32. The temperature of the heat medium compressed by the compressor 32 rises in a gaseous state. The heat medium whose temperature has risen flows into the heat medium flow path 26 of the hot water supply heat exchanger 24. Water having a temperature lower than that of the heat medium flowing through the heat medium flow path 26 flows through the water flow path 27 of the hot water supply heat exchanger 24. The heat medium flowing through the heat medium flow path 26 is cooled by exchanging heat with the water flowing through the water flow path 27. The cooled heat medium undergoes a phase change from a gaseous state to a liquid state. The water flowing through the water flow path 27 is heated by the heat medium flowing through the heat medium flow path 26 and the temperature rises.
The liquid heat medium that has flowed out of the heat medium flow path 26 of the hot water supply heat exchanger 24 flows through the circulation return path 34. The heat medium flowing through the circulation return path 34 is expanded by the pressure reducing valve 37, so that the temperature is lowered. The liquid heat medium having a lowered temperature flows into the outside heat exchanger 20.

The hot water supply device 10 performs an operation of storing hot water in the hot water storage tank 46, supplying hot water to a hot water tap or the like, and sterilizing the hot water storage tank 46. Hereinafter, these operations will be described.
First, the operation of storing hot water in the hot water storage tank 46 will be described with reference to FIG. At this time, the heat pump 12 is operated. The burner 53 is not burned. It is assumed that water is stored in the hot water storage tank 46 and hot water is not supplied from the sixth flow path 84 to the hot water tap or the like. Since hot water is not supplied from the sixth channel 84, tap water does not flow into the first channel 56. The flow path filled in FIG. 1 indicates that the heat medium and water are circulating. The direction of circulation of the heat medium and water is indicated by arrows.

When hot water is stored in the hot water storage tank 46, the first flow rate adjustment valve 72 is opened and the pump 73 is driven. The first three-way valve 64 brings the second flow paths 60 into circulation. The second three-way valve 77 brings the fifth flow path 75 into communication. The third three-way valve 82 brings the eighth channel 81 and the eleventh channel 94 into communication. When the pump 73 is driven, water flows from the fourth channel 70 into the water channel 27 of the hot water supply heat exchanger 24. The water flowing through the water flow path 27 is heated by the heat medium flowing through the heat medium flow path 26 and the temperature rises. The water whose temperature has risen flows through the fifth flow path 75 and the seventh flow path 78 and is sent to the hot water storage tank 46. By feeding water into the hot water storage tank 46, water is sent out from the lower part of the hot water storage tank 46 to the third flow path 66. The water sent to the third flow path 66 flows through the latent heat exchanger 51, the second flow path 60, and the fourth flow path 70 of the burner unit 50 and is sucked into the pump 73. The water heated by the hot water supply heat exchanger 24 and raised in temperature is sent to the hot water storage tank 46, and the water is further sent out from the hot water storage tank 46 and returned to the hot water supply heat exchanger 24 to repeat hot water in the hot water storage tank 46. (Hot water) is stored.
The controller 95 adjusts the operating strength of the heat pump 12 and the pump 73 and the opening degree of the first flow rate adjustment valve 72 based on the temperatures detected by the sensors 47, 68, 76, and 80. When the controller 95 adjusts the operating strength of the heat pump 12, the compression rate of the compressor 32 and the opening degree of the pressure reducing valve 37 are adjusted based on the detected temperatures of the sensors 33, 40, and 41.

The operation when the hot water supply apparatus 10 supplies hot water will be described for the following cases (1), (2), and (3).
(1) When the temperature of the water stored in the hot water storage tank is higher than the required hot water supply temperature.
As shown in FIG. 2, it is assumed that 45 ° C. water is stored in the hot water storage tank 46 and the required hot water supply temperature is 38 ° C. It is detected by the fourth sensor 47 that 45 ° C. water is stored in the hot water storage tank 46. The hot water supply required temperature is set by the user operating the remote controller 96.
In this case, the heat pump 12 is operated. The burner 53 is not burned. While opening the 1st flow regulating valve 72, the pump 73 is stopped. The first three-way valve 64 brings the second flow paths 60 into circulation. The second three-way valve 77 brings the fifth flow path 75 into communication. The third three-way valve 82 brings the seventh flow path 78 and the eighth flow path 81 into communication.
A tap water pressure is applied to the first flow path 56. Therefore, when a hot water tap or the like provided on the downstream side of the sixth flow path 84 is opened, the first flow path 56, the second flow path 60, the latent heat exchanger 51, and the third flow path 66 are passed. Water enters the lower part of the hot water storage tank 46. The supply of tap water to the first flow path 56 is detected by the flow sensor 59. When water enters the lower part of the hot water storage tank 46, 45 ° C. water is sent from the upper part to the seventh flow path 78.

The tap water supplied to the first flow path 56 also flows into the fourth flow path 70 in the middle of the second flow path 60. The water that has flowed into the fourth flow path 70 passes through the first flow rate adjustment valve 72 and the pump 73. As described above, the pump 73 is stopped. Even if the pump 73 is stopped, the water passes through the flow path in the pump 73. The water flowing through the fourth flow path 70 is heated by passing through the hot water supply heat exchanger 24, and the temperature rises to 28 ° C. The water temperature is detected by the fifth sensor 76. The water whose temperature has risen flows through the fifth flow path 75 and is mixed with the water sent out from the hot water storage tank 46 through the seventh flow path 78. The mixed water becomes 42 ° C. The water temperature is detected by the seventh sensor 80.
The water exiting the seventh flow path 78 flows through the eighth flow path 81, the sensible heat exchanger 52, and the ninth flow path 86 after passing through the third three-way valve 82. On the other hand, the tap water that has flowed into the second flow path 60 from the first flow path 56 also flows into the tenth flow path 90. The water that has flowed into the tenth flow path 90 is mixed with the water that has flowed through the ninth flow path 86 in the sixth flow path 84. The amount of water flowing through the tenth flow path 90 is adjusted by the second flow rate adjustment valve 91. When the second flow rate adjusting valve 91 adjusts the amount of water flowing through the tenth flow path 90, the detected temperature of the sixth sensor 79 or the eighth sensor 88 is used. The second flow rate adjusting valve 91 adjusts the amount of water (15 ° C.) flowing through the tenth flow path 90 mixed with the water (42 ° C.) flowing through the ninth flow path 86, thereby Water of 38 ° C. as hot water supply required temperature is supplied from the path 84 to a hot water tap or the like.
As already described, the water (28 ° C.) heated by the hot water supply heat exchanger 24 of the heat pump 12 is mixed with the water (45 ° C.) sent out from the hot water storage tank 46. For this reason, the water (hot water) stored in the hot water storage tank 46 can be saved by the amount of water heated by the hot water supply heat exchanger 24.

(2) When the temperature of the water stored in the hot water storage tank is lower than the required hot water supply temperature.
As shown in FIG. 3, it is assumed that the hot water storage tank 46 contains 33 ° C. water. It is assumed that the required hot water supply temperature is 42 ° C.
In this case, the heat pump 12 is operated. Burner 53 is burned. While opening the 1st flow regulating valve 72, the pump 73 is stopped. The first three-way valve 64 brings the second flow paths 60 into circulation. The second three-way valve 77 brings the fifth flow path 75 into communication. The third three-way valve 82 brings the seventh flow path 78 and the eighth flow path 81 into communication. The second flow rate adjustment valve 91 is closed.
When the hot water tap or the like is opened, 15 ° C. water (tap water) flowing through the first flow path 56 and the second flow path 60 flows into the latent heat exchanger 51. In the latent heat exchanger 51, the water vapor contained in the gas combusted in the burner 53 is cooled to water passing through the latent heat exchanger 51 and condensed to become water. The water whose temperature has risen to 33 ° C. by absorbing the latent heat (condensation heat) generated at that time and heated by the combustion gas of the burner 53 flows from the latent heat exchanger 51 into the third flow path 66. . The water flowing through the third flow path 66 enters the hot water storage tank 46. For this reason, the water temperature in the hot water storage tank 46 becomes 33 ° C.

When water enters the lower part of the hot water storage tank 46, 33 ° C. water is sent from the upper part to the seventh flow path 78. The tap water supplied to the first flow path 56 also flows into the fourth flow path 70. The water flowing through the fourth flow path 70 is heated by passing through the hot water supply heat exchanger 24, and the temperature rises to 28 ° C. The water whose temperature has risen flows through the fifth flow path 75 and is mixed with the water sent out from the hot water storage tank 46 through the seventh flow path 78. The mixed water becomes 31 ° C.
The water that has exited the seventh flow path 78 flows into the sensible heat exchanger 52 through the eighth flow path 81. The water flowing into the sensible heat exchanger 52 is heated by the combustion gas of the burner 53. By adjusting the combustion strength of the burner 53, the water that has passed through the sensible heat exchanger 52 becomes 42 ° C., which is the required hot water supply temperature. In adjusting the combustion strength of the burner 53, the detected temperatures of the sixth sensor 79, the seventh sensor 80, and the eighth sensor 88 are used. The 42 ° C. water that has passed through the sensible heat exchanger 52 flows through the ninth flow path 86 and the sixth flow path 84 and is supplied to a hot water tap or the like.

  As described above, the hot water storage tank 46 is filled with 33 ° C. water heated by the latent heat exchanger 51. Before that, water having a temperature (for example, 45 ° C.) higher than the required hot water supply temperature may enter the hot water storage tank 46. That is, it is the case of (1) described above. In that case, the burner 53 is not burned until the water at 45 ° C. in the hot water storage tank 46 is consumed. Since the burner 53 does not burn, 15 ° C. water (tap water) enters the hot water storage tank 46 from the lower part thereof. Water of 45 ° C. is consumed in a state where a high temperature (45 ° C.) temperature stratification is formed on a low temperature (15 ° C.) temperature stratification. When 45 ° C. water is consumed, 15 ° C. water is sent out from the hot water storage tank 46. This is detected by the seventh sensor 80. When 15 ° C. water is sent out from the hot water storage tank 46, the burner 53 is combusted. When the burner 53 burns, water at, for example, 30 ° C. is fed into the lower part of the hot water storage tank 46 from the latent heat exchanger 51. Since 30 ° C. water having a higher temperature is fed into the lower part of the hot water storage tank 46 containing 15 ° C. water, convection occurs in the hot water storage tank 46. For this reason, a clear temperature stratification is not formed in the hot water storage tank 46. Finally, the hot water storage tank 46 is filled with 30 ° C. water.

(3) When the burner 53 is subjected to minimum combustion, the temperature of the water flowing out from the sensible heat exchanger 52 exceeds the required hot water supply temperature.
Minimum combustion is a state in which the burner 53 is burning weakest. When the burner 53 is subjected to minimum combustion, the temperature of the water flowing out from the sensible heat exchanger 52 exceeds the required hot water supply temperature when the temperature of the water stored in the hot water storage tank 46 is slightly lower than the required hot water supply temperature. Occurs.
As shown in FIG. 4, it is assumed that the hot water storage tank 46 contains 38 ° C. water and the required hot water supply temperature is 42 ° C. The states of the flow rate adjustment valve and the three-way valve are the same as in the case of (2) described above except that the second flow rate adjustment valve 91 is opened. The heat pump 12 operates weakly. The water of 35 ° C. flows into the sensible heat exchanger 52 by mixing the water of 21 ° C. heated by the hot water supply heat exchanger 24 with the 38 ° C. water sent out from the hot water storage tank 46. Since the temperature of the water flowing into the sensible heat exchanger 52 is 35 ° C. and is lower than the required hot water supply temperature of 42 ° C., the burner 53 needs to be operated. When the burner 53 is operated, the temperature of the water flowing out of the sensible heat exchanger 52 exceeds the required hot water supply temperature of 42 ° C. The water that has flowed out of the sensible heat exchanger 52 flows through the ninth flow path 86 and flows into the sixth flow path 84. The sixth channel 84 is mixed with low-temperature (15 ° C.) water whose flow rate is adjusted from the tenth channel 90 by the second flow rate adjustment valve 91. In this manner, 42 ° C. water as hot water supply required temperature is supplied from the sixth channel 84 to the hot water tap or the like.

The amount of hot water supplied from the sixth flow path 84 is regulated by the opening degree of the hot water tap. Therefore, if the ratio of the amount of water flowing from the tenth channel 90 to the sixth channel 84 is increased with respect to the amount of water flowing from the sensible heat exchanger 52 to the sixth channel via the ninth channel 86, The water sent out from the hot water storage tank 46 can be saved.
As already described, by operating the heat pump 12 weakly, the water at 21 ° C. heated by the hot water supply heat exchanger 24 is mixed with the 38 ° C. water delivered from the hot water storage tank 46. By mixing the water heated by the hot water supply heat exchanger 24 with the water sent out from the hot water storage tank 46, the temperature of the water heated by the burner 53 and flowing out from the sensible heat exchanger 52 becomes high. When the temperature of the water flowing out from the sensible heat exchanger 52 increases, the amount of water flowing into the sixth flow path 84 from the tenth flow path 90 increases. Therefore, the water sent out from the hot water storage tank 46 can be saved.
The heat pump 12 can also be operated strongly. When the heat pump 12 is operated strongly, the energy efficiency of the hot water supply device 10 is reduced, but water sent from the hot water storage tank 46 can be further saved.

The sterilization operation performed by the hot water supply apparatus 10 will be described. In the sterilization operation, the controller 95 performs the sterilization process shown in FIG. In S10 which is the first process of the sterilization process, it is determined whether or not the first predetermined period has elapsed since the previous sterilization process was executed. The first predetermined period is set to a period (for example, 48 hours) in which many kinds of bacteria such as Legionella bacteria may grow in the water stored in the hot water storage tank 46. When it is determined that the first predetermined period has not elapsed since the previous sterilization process was performed in S10 (in the case of NO), the process waits as it is. When it is determined that the first predetermined period has elapsed since the previous sterilization process was executed in S10 (in the case of YES), the process proceeds to S12.
In S12, the first sterilization mode is executed. As shown in FIG. 6, the first three-way valve 64 is in a state in which the second flow paths 60 are circulated. The second three-way valve 77 is in a state where the fifth flow paths 75 are circulated. The third three-way valve 82 causes the seventh flow path 78 and the eighth flow path 81 to flow. The heat pump 12 is not operated. While closing the 1st flow regulating valve 72, the pump 73 is stopped. Burner 53 is burned strongly. It is assumed that 35 ° C. water is stored in the hot water storage tank 46. It is assumed that the required hot water supply temperature is 40 ° C.

When a hot water tap or the like provided on the downstream side of the sixth flow path 84 is opened in this state, it is detected by the flow sensor 59. When the hot water tap or the like is opened, water enters the lower portion of the hot water storage tank 46 through the first flow path 56, the second flow path 60, the latent heat exchanger 51, and the third flow path 66. The burner 53 burns strongly. The temperature of the water that has passed through the latent heat exchanger 51 rises. When water enters the lower part of the hot water storage tank 46, 35 ° C. water is sent from the upper part to the seventh flow path 78. The water that has flowed out of the seventh flow path 78 flows into the sensible heat exchanger 52 through the eighth flow path 81. As the burner 53 burns strongly, the temperature of the water that has passed through the sensible heat exchanger 52 becomes 70 ° C. When the temperature of the water reaches 70 ° C., germs contained in the water sent out from the hot water tank 46 are disinfected. When the temperature of the water is heated to 70 ° C., germs are killed after 5 seconds. The water whose temperature has risen after passing through the sensible heat exchanger 52 flows into the sixth channel 84 through the ninth channel 86. 15 ° C. water (tap water) whose flow rate is adjusted by the second flow rate adjustment valve 91 also flows into the sixth flow channel 84 from the tenth flow channel 90. By mixing 70 ° C. water and 15 ° C. water in the sixth flow path 84, 40 ° C. water, which is a required hot water supply temperature, is supplied to a hot water tap or the like.
When the burner 53 is strongly burned and heated to 70 ° C., the amount of hot water required for mixing with cold water to obtain mixed hot water of 40 ° C. may be reduced. Since the water whose temperature has risen through the sensible heat exchanger 52 has a small flow rate, it slowly flows through the ninth flow path 86 and mixes with tap water after 5 seconds or more. Since the water stored in the hot water storage tank is maintained at 70 ° C. for 5 seconds or longer and then mixed with tap water, the germs die during that time.
As shown in FIG. 14, a bypass flow path 104 and a three-way valve 102 may be prepared for the first mode sterilization. In the first sterilization mode, the AB port is opened as shown in FIG. The water whose temperature has risen after passing through the sensible heat exchanger 52 flows through the bypass flow path 104 and then merges with the tap water. The AC port is opened except in the first sterilization mode. The water whose temperature has risen after passing through the sensible heat exchanger 52 is promptly sent to the hot water supply location. When the bypass passage 104 and the three-way valve 102 are used, hot water supply can be started quickly at a hot water supply location except during the sterilization mode, and the sterilization mode can be reliably sterilized.
Since the hot water supply process S10 of FIG. 5 is provided, the first sterilization mode is periodically executed. For this reason, while being able to sterilize the water to supply hot water reliably, performing a useless sterilization is prevented by setting the 1st predetermined period appropriately.

As shown in FIG. 5, in S14 following S12, it is determined whether or not the accumulated hot water flow rate after starting the first sterilization mode has reached a predetermined amount. The accumulated hot water flow rate is calculated using the detection value of the flow rate sensor 59. The predetermined amount of the accumulated hot water flow is a value obtained by multiplying the capacity of the hot water storage tank 46 by a predetermined amount. The predetermined amount is set in this way for the following reason. That is, the flow rate detected by the flow sensor 59 is the flow rate of water sent to the hot water storage tank 46 (equal to the flow rate sent from the hot water storage tank 46) and the flow rate of water passing through the tenth flow path 90 (hot water storage tank 46). And the flow rate of water that bypasses the sensible heat exchanger 52). Therefore, if the predetermined amount of the accumulated hot water flow rate is the capacity of the hot water storage tank 46 and the first sterilization mode is terminated when the accumulated hot water flow rate reaches the predetermined amount, the hot water storage tank 46 is filled with the first sterilization mode. All of the stored water has not been sent out and sterilized. By setting the predetermined amount of the accumulated hot water flow rate to a value obtained by multiplying the capacity of the hot water storage tank 46 by a predetermined value, when the accumulated hot water flow rate reaches the predetermined amount, the accumulated hot water flow rate is stored in the hot water storage tank 46 when the first sterilization mode is started. All the water can be sent out and sterilized. For example, if the ratio of the flow rate of the water fed into the hot water storage tank 46 and the flow rate of the water bypassing the hot water storage tank 46 is “1: 0.5” even when it is maximized, a predetermined amount of the accumulated hot water flow rate Is 1.5 times the capacity of the hot water storage tank 46.
Instead of the above, the mixing ratio of hot water and cold water is calculated from the water temperature heated by the sensible heat exchanger 52, the tap water temperature, and the remote control set temperature, and the hot water storage tank 46 is calculated from the detected amount and mixing ratio of the flow sensor 59. It is also possible to calculate the flow rate of the water sent out from and to end the first sterilization mode when it becomes equal to the tank capacity. For the sake of safety, the first sterilization mode may be terminated in comparison with the amount added to the tank capacity.
As described above, in the first sterilization mode, the first flow rate adjustment valve 72 is closed. When the first flow rate adjustment valve 72 is closed, water does not pass through the fifth flow path 75. For this reason, the amount of water delivered from the hot water storage tank 46 is increased. For this reason, it becomes possible to complete | finish a 1st disinfection mode earlier.
It is also possible to estimate that all the water stored in the hot water storage tank 46 when the flow rate sensor is attached to another part and the first sterilization mode is started is sent out. For example, the flow rate sensor directly detects the amount of water sent out from the hot water storage tank 46.
By detecting the temperature of the water immediately after being sent out from the hot water storage tank 46 or the temperature of the water in the hot water storage tank 46 with the temperature sensor, the water stored in the hot water storage tank 46 when the first sterilization mode is started. You can also estimate that everything was sent out

As shown in FIG. 5, when it is determined that the accumulated hot water flow rate after starting the first sterilization mode in S14 has reached a predetermined amount (in the case of YES), the process proceeds to S16 to shift to the first sterilization mode. Exit. After ending the first sterilization mode, the sterilization process is ended.
When it is determined that the accumulated hot water flow rate after starting the first sterilization mode in S14 has not reached the predetermined amount (in the case of NO), S20 is performed. In S20, it is determined whether or not a second predetermined period has elapsed since the start of the first sterilization mode. When it is determined that the second predetermined period has not elapsed since the first sterilization mode was started in S20 (in the case of NO), S14 is executed again. When it is determined that the second predetermined period has elapsed since the start of the first sterilization mode in S20 (in the case of YES), the process proceeds to S22 to execute the second sterilization mode. The second predetermined period is set with an allowance for a period during which the hot water flow rate after starting the first sterilization mode will exceed the accumulated hot water flow rate when the user performs normal hot water supply. ing. Therefore, YES is determined in S20 when the amount of hot water supplied during the first sterilization mode is very small. As will be described in detail later, in the second sterilization mode executed when YES is determined in S22, the hot water storage tank 46 can be sterilized without performing hot water supply.

The operation of the hot water supply apparatus 10 in the second sterilization mode of S22 will be described with reference to FIG. In the second sterilization mode, the heat pump 12 is operated and the burner 53 is combusted. While opening the 1st flow regulating valve 72, the pump 73 is driven. The first three-way valve 64 brings the second flow paths 60 into circulation. The second three-way valve 77 causes the upstream side of the fifth flow path 75 and the sixth flow path 84 to flow. The third three-way valve 82 causes the seventh flow path 78 and the eighth flow path 81 to flow. The second flow rate adjustment valve 91 is closed.
When the pump 73 is driven, water flows into the hot water supply heat exchanger 24 from the fourth flow path 70 and is heated. The heated and heated water flows from the fifth flow path 75 through the second three-way valve 77 and flows into the sixth flow path 84. The water flowing into the sixth flow path 84 passes through the ninth flow path 86 and then passes through the sensible heat exchanger 52. The water passing through the sensible heat exchanger 52 is heated by the combustion gas of the burner 53 and the temperature rises. The water whose temperature has risen through the sensible heat exchanger 52 flows through the eighth flow path 81, the third three-way valve 82, and the seventh flow path 78 and enters the upper portion of the hot water storage tank 46.

Water flows into the third flow path 66 from the lower part of the hot water storage tank 46. The water flowing into the third flow channel 66 passes through the latent heat exchanger 51. The water that has passed through the latent heat exchanger 51 recovers the latent heat and is heated by the combustion gas of the burner 53 to further increase the temperature. The water whose temperature has further increased after passing through the latent heat exchanger 51 flows into the second flow path 60. The water that has flowed into the second flow path 60 flows into the fourth flow path 70 from the middle of the second flow path 60. In this way, the water sent out from the hot water storage tank 46 is heated by the hot water supply heat exchanger 24 and the burner 53 and is repeatedly circulated back to the hot water storage tank 46, whereby the inside of the hot water storage tank 46 is heated to a high temperature (for example, 60 ° C.). become. The state where the temperature of the hot water storage tank 46 is high is continued for a specific time (for example, 5 minutes). The bacteria are sterilized by continuing the state in which the temperature of the hot water storage tank 46 is high for a predetermined time.
As shown in FIG. 5, after the second sterilization mode is executed, the sterilization process is terminated.

A case where a hot water tap or the like is opened during the execution of the second sterilization mode, that is, a case where a hot water supply is requested will be described with reference to FIG. It is assumed that the required hot water supply temperature is 38 ° C.
In this case, the operation of the heat pump 12 is stopped. Burner 53 continues to burn. While closing the 1st flow regulating valve 72, the pump 73 is stopped. The first three-way valve 64 brings the second flow path 60 into the state where the relief valve 62 side and the eleventh flow path 94 are circulated. The third three-way valve 82 causes the eighth flow path 81 and the eleventh flow path 94 to flow. The second flow rate adjustment valve 91 is closed.
When a hot water tap or the like is opened, tap water passes through the first flow path 56, the second flow path 60, the first three-way valve 64, and the eleventh flow path 94 and then passes through the sensible heat exchanger 52. The water that has passed through the sensible heat exchanger 52 is heated by the combustion gas of the burner 53 and becomes 38 ° C. water, which is the required hot water supply temperature. The water that has passed through the sensible heat exchanger 52 flows through the ninth flow path 86 and the sixth flow path 84 and is supplied to a hot water tap or the like.
According to this hot water supply apparatus 10, even if there is a hot water supply request during the second sterilization mode, it is possible to immediately execute hot water supply without consuming water contained in the hot water storage tank 46. The sterilization operation can be resumed after the hot water supply request is completed.

Thermal efficiency of the hot water supply apparatus 10 when the water fed from the hot water storage tank 46 is sterilized at a high temperature (corresponding to the first sterilization mode) and when the hot water tank 46 is sterilized at a high temperature (corresponding to the second sterilization mode) Compare When the water sent out from the hot water storage tank 46 is sterilized at a high temperature, the amount of heat generated by the burner 53 heating the water is effectively used for hot water supply. In contrast, when sterilizing the hot water storage tank 46 at a high temperature, after the sterilization is completed, the temperature of the water in the hot water storage tank 46 decreases while radiating heat to the outside. The amount of heat dissipated outside is wasted. Therefore, sterilizing the water sent out from the hot water storage tank 46 at a high temperature is superior in thermal efficiency to sterilizing the hot water storage tank 46 at a high temperature.
When sterilizing the hot water storage tank 46 at a high temperature, it is necessary to increase the thickness of the heat insulating material that covers the hot water storage tank 46 in order to reduce heat radiation to the outside as much as possible. If the water sent out from the hot water storage tank 46 is sterilized at a high temperature, the thickness of the heat insulating material can be reduced or the heat insulating material can be omitted.

Specific examples of the present invention have been described in detail above, but these are merely examples and do not limit the scope of the claims. The technology described in the claims includes various modifications and changes of the specific examples illustrated above.
In addition, the technical elements described in the present specification or drawings exhibit technical usefulness alone or in various combinations, and are not limited to the combinations described in the claims at the time of filing. In addition, the technology illustrated in the present specification or the drawings achieves a plurality of objects at the same time, and has technical utility by achieving one of the objects.

System diagram of hot water supply system (during hot water storage). System diagram of hot water supply system (hot water storage temperature> required hot water supply temperature). System diagram of hot water supply system (hot water storage temperature <required hot water supply temperature). System diagram of hot water supply system (burner is burning minimum). The flowchart of a sterilization process. System diagram of the hot water supply device (first sterilization mode). System diagram of the hot water supply device (second sterilization mode). System diagram of the hot water supply system (when there is a hot water supply request while sterilizing the hot water storage tank). The figure which illustrates typically the concept of invention. The figure which illustrates typically the concept of invention. The figure which illustrates typically the concept of invention. The figure which illustrates typically the concept of invention. The figure which illustrates typically the concept of invention. System diagram of the hot water supply device (first sterilization mode). The modification of the systematic diagram of FIG. 6 is shown.

Explanation of symbols

10: Hot water supply device 12: Heat pump 20: Outside air heat exchanger 21: Blower 22: Fan 23: Electric motor 24: Hot water supply heat exchanger 25: Outlet 26: Heat medium flow path 27: Water flow path 30: Circulation forward path 31: Inlet 32 : Compressor 33: first sensor 35: outlet 36: inlet 34: circulation return path 37: pressure reducing valve 40: second sensor 41: third sensor 45: hot water storage section 46: hot water storage tank 47: fourth sensor 50: burner section 51 : Latent heat exchanger 52: sensible heat exchanger 53: burner 54: burner fan 56: first flow path 57: one end 58: other end 59: flow sensor 60: second flow path 62: relief valve 63: one end 64: 1st three-way valve 66: 3rd flow path 67: The other end 68: 5th sensor 70: 4th flow path 71: Inlet 72: 1st flow control valve 73: Pump 74: Outlet 75: 5th flow path 76: 1st 5 sensor 77: second three-way valve 78 7th flow path 79: 6th sensor 80: 7th sensor 81: 8th flow path 82: 3rd three-way valve 83: One end 84: 6th flow path 85: Upstream end 86: 9th flow path 87: Other end 88 : 8th sensor 90: 10th flow path 91: 2nd flow regulating valve 92: One end 93: The other end 94: 11th flow path 95: Controller 96: Remote control

Claims (7)

It is a hot water supply device that can sterilize the water sent from the hot water storage tank to the hot water supply location,
A hot water supply path for sending tap water to a hot water supply point through a hot water storage tank and a burner type heat exchanger,
A cold water path for joining the tap water with the water sent from the burner heat exchanger between the burner heat exchanger and the hot water supply point;
Water amount adjusting means for adjusting the amount of water passing through the cold water path;
Hot water supply amount detection means for detecting the amount of water supplied to the hot water supply location;
It has a controller to which a burner type heat exchanger, water amount adjusting means and hot water supply amount detecting means are connected,
The controller burns the burner heat exchanger more strongly during the sterilization process than during the non-sterilization process, and the integrated value of the amount of water detected by the hot water supply amount detection means after the start of the sterilization process by the burner type heat exchanger becomes a predetermined value. When it becomes, the hot water supply apparatus characterized by complete | finishing the sterilization process by a burner type heat exchanger. It is a hot water supply device that can sterilize the water sent from the hot water storage tank to the hot water supply location,
A hot water supply path for sending tap water to a hot water supply point through a hot water storage tank and a burner type heat exchanger,
A cold water path for joining the tap water with the water sent from the burner heat exchanger between the burner heat exchanger and the hot water supply point;
Water amount adjusting means for adjusting the amount of water passing through the cold water path;
Temperature detecting means for detecting the temperature of water before being sent out from the hot water storage tank and flowing into the burner type heat exchanger;
It is equipped with a controller to which a burner type heat exchanger, water amount adjusting means and temperature detecting means are connected,
The controller burns the burner-type heat exchanger more strongly during the sterilization process than during the non-sterilization process, and terminates the sterilization process by the burner-type heat exchanger when the temperature detection means detects a predetermined temperature. Hot water supply device. A heating path that branches from the flow path leading tap water to the hot water storage tank, passes through the heating means, and joins the flow path connecting the hot water storage tank and the burner heat exchanger;
Opening and closing means capable of opening and closing the heating path;
A pump that returns the water stored in the hot water storage tank to the hot water storage tank via the heating path;
Switching means for enabling either or both of the hot water supply path and the heating path,
3. The hot water supply apparatus according to claim 1, wherein the controller closes the opening / closing means when performing sterilization in a state where the hot water supply path is enabled by the switching means. 4. It has a sterilization path for returning the water stored in the hot water storage tank to the hot water storage tank through the burner type heat exchanger by the pump,
The controller enables any one of the hot water supply path, the heating path, and the sterilization path by the switching means, and the hot water supply amount detection means detects even if the first predetermined period has elapsed from the start of the sterilization process by the burner type heat exchanger. 4. The hot water supply apparatus according to claim 3, wherein the sterilization path is validated when the integrated value of the hot water supply flow rate does not reach a predetermined value. The burner type heat exchanger includes a sensible heat exchanger that heats water with the combustion heat of the burner and a latent heat exchanger that heats water with the condensation latent heat of water vapor contained in the combustion gas of the burner.
A latent heat exchanger is interposed between the branch point to the heating path and the hot water storage tank,
The hot water supply device according to claim 3 or 4, wherein a sensible heat exchanger is interposed between a junction from the heating path and a junction from the cold water path.   6. The hot water supply apparatus according to claim 3, wherein the heating means is a heat pump.   7. The controller according to claim 1, wherein the controller starts the sterilization process by the burner type heat exchanger when the second predetermined period has elapsed after the sterilization process by the burner type heat exchanger has been completed. Water heater.

Images