JP5137131B2 - Water heater - Google Patents

Description

  The present invention relates to a hot water supply apparatus that uses a plurality of hot water storage tanks connected in series.

  Conventionally, for example, in a hot water supply apparatus using two hot water storage tanks, the lower part of the upper hot water storage tank and the upper part of the lower hot water storage tank are connected in series with a connection pipe, and a water supply path is provided below the lower hot water storage tank. A boiling circuit is connected to the upper part of the two hot water storage tanks so that hot water can be switched from either one. Further, a boiling circuit is connected to take out water from the lower part of the lower hot water storage tank, send it to the heat pump unit, and return the hot water boiled by this heat pump unit to the upper part of the upper hot water storage tank.

  In addition, for heat exchange with the heat load such as floor heating and reheating of bathtub water, hot water is taken out from the upper part of the upper hot water storage tank and sent to the heat load heat exchanger. A thermal load circuit is connected to return the medium temperature water whose temperature has been lowered by heat exchange to the lower part of the lower hot water storage tank.

  In such a hot water supply apparatus, there may be a case where medium temperature water accumulates in the hot water storage tank due to heat exchange with the heat load, or a large amount of medium temperature water whose temperature has decreased without using the remaining hot water of the previous day may remain. Although this medium temperature water is about 35-40 degreeC and is higher than a feed water temperature, it is lower than the hot water supply temperature normally utilized at about 42 degreeC, and cannot be used for hot water supply as it is.

  It is known that when a large amount of medium-temperature water remains in the hot water storage tank, the boiling efficiency when boiling water from the medium-temperature water by the heat pump unit is significantly lower than when boiling water from water.

Therefore, if it is detected that hot water is present at the upper part of the lower hot water storage tank, the hot water supply ratio from the lower hot water storage tank is increased, and then mixed hot water is supplied from the upper part of both the upper and lower hot water storage tanks. If there is no hot water in the upper part of the lower hot water storage tank and medium temperature water is detected, the hot water supply ratio from the upper hot water storage tank is increased and mixed hot water is supplied from the upper part of both the upper and lower hot water storage tanks. If medium temperature water disappears in the upper part of the lower hot water storage tank and water is detected, hot water is supplied only from the upper hot water storage tank. Thereby, medium temperature water is utilized for hot water supply, and the amount of medium temperature water remaining in the hot water storage tank is reduced (for example, refer to Patent Document 1).
Japanese Patent Laying-Open No. 2005-315460 (page 4-5, FIG. 1-2)

  As described above, in a hot water supply apparatus in which two hot water storage tanks are connected in series, if hot water disappears in the upper part of the lower hot water storage tank and medium temperature water is detected, the hot water supply ratio from the upper hot water storage tank is increased. By trying to supply hot water from the upper part of both the upper and lower hot water storage tanks, we are trying to reduce the medium temperature water remaining in the hot water storage tank, but in order to supply hot water from the upper hot water storage tank as well, Medium temperature water flows in from the lower hot water storage tank, and the medium hot water that has flowed into the upper hot water storage tank cannot be used for hot water supply and remains.

  For this reason, there is a problem that the intermediate hot water remains in the upper hot water storage tank, and the amount of heat of the intermediate hot water cannot be effectively used, and the boiling efficiency when boiling the hot water from the intermediate hot water by the heat pump unit is reduced.

  This invention is made in view of such a point, and it aims at providing the hot-water supply apparatus which can prevent the fall of the boiling-up efficiency at the time of boiling off hot water with a heat pump unit, eliminating the intermediate temperature water in a hot water storage tank. Do

  The hot water supply apparatus according to claim 1, a plurality of hot water storage tanks, a connection pipe that connects a lower part of the upper hot water storage tank and an upper part of the lower hot water storage tank in series, and the vertical direction of each hot water storage tank Temperature sensors that detect the temperature of hot water in hot water storage tanks at different heights, a water supply channel that supplies water to the lower part of the hot water storage tank with the lowest connection order, and a heat pump used for boiling water A unit and a boiling circuit that takes out water from the lower part of the hot water storage tank with the lowest connection order, sends it to the heat pump unit, and switches the hot water boiled by the heat pump unit back to one of the upper parts of the plurality of hot water storage tanks And a hot water supply path that allows hot water to be switched from any of the upper parts of the plurality of hot water storage tanks, and a switching state in which hot water is supplied from the upper part of the hot water storage tank having the highest connection order. It is detected that there is water in the upper part of the hot water storage tank next to the highest rank, and hot water of a predetermined temperature or higher that can be used for hot water supply is stored in the upper part of the hot water storage tank and the lower part. If it is detected that there is medium temperature water that is higher than the feed water temperature but cannot be used for hot water supply as it is, the heat pump unit and the boiling circuit allow a predetermined amount of hot water to be placed above the next hot water storage tank. And a controller for storing hot water.

  The hot water supply device according to claim 2 is the hot water supply device according to claim 1, wherein the control unit stores hot water in a plurality of hot water storage tanks by a heat pump unit and a boiling circuit during hot water storage operation in a specific time zone. Sometimes, hot water stored in the lower hot water storage tank is supplied by the hot water supply passage, and when hot water is supplied from the next hot water storage tank, it is detected that there is no hot water in the upper part of the next hot water storage tank, and the water becomes hot. Then, the hot water at the top of the top hot water storage tank was mixed with the hot water at the top of the hot water storage tank at the top, and the hot water at the top of the next hot water storage tank was changed from medium hot water to water. And when it is detected that there is medium temperature water in the lower part of the uppermost hot water storage tank, a predetermined amount of hot water is stored in the upper part of the next hot water storage tank by the heat pump unit and the boiling circuit. The salary The road is intended to hot water only from the hot water storage tank of the highest level.

  According to the hot water supply apparatus of the first aspect, it is detected that there is water in the upper part of the hot water storage tank of the next connection order in the switching state in which hot water is supplied from the upper part of the hot water storage tank of the highest connection order, and the highest It has been detected that hot water of a predetermined temperature or higher that can be used as it is for hot water supply is stored in the upper part of the upper hot water storage tank, and that there is medium temperature water that is lower than the predetermined temperature that is higher than the hot water supply temperature but cannot be used for hot water supply in the lower part. Therefore, in order to store a predetermined amount of hot water in the upper part of the next hot water storage tank, the hot water in the upper part of the next hot water tank is changed to Mixing with the middle-temperature water at the bottom, raising the temperature to a predetermined temperature that can be used as it is for hot water supply, eliminates the middle-temperature water, and prevents a decrease in boiling efficiency when boiling water with the heat pump unit. It can be.

  According to the hot water supply device of claim 2, in addition to the effect of the hot water supply device of claim 1, when hot water is supplied, hot water stored in the lower hot water storage tank is supplied by the hot water supply path. If it is detected that hot water has disappeared from the hot water storage tank at the top of the next hot water tank and the water has become medium hot water, the hot water at the top of the top hot water tank and the top of the next hot water tank are It is detected that the upper temperature of the next hot water storage tank has changed from medium temperature water to water, and there is medium temperature water at the lower part of the uppermost hot water storage tank. If detected, a predetermined amount of hot water is stored in the upper part of the next hot water storage tank by the heat pump unit and the boiling circuit, and hot water is supplied only from the uppermost hot water storage tank by the hot water supply passage. Make sure to remove hot water It can be.

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

  As shown in FIG. 1, the hot water supply device 11 includes a tank unit 12 and a heat pump unit 13 that is used for boiling water, and has a function of adding water to the bathtub 14.

  The tank unit 12 includes a hot water storage tank (hereinafter referred to as a first hot water storage tank) 16 and a lower hot water storage tank (hereinafter referred to as a second hot water storage tank) 17 which are connected in series and used in an upper order. Have. The lower part of the first hot water storage tank 16 and the upper part of the second hot water storage tank 17 are connected in series by a connection pipe 18.

  The first hot water storage tank 16 and the second hot water storage tank 17 are temperature sensors S1 that detect the hot water temperature in the tanks at different height positions in the vertical direction, for example, at three locations, an upper portion, an intermediate portion, and a lower portion. To S3 and temperature sensors S4 to S6 are respectively arranged.

  A water supply channel 20 connected to a water supply source such as a water pipe is connected to the lower part of the second 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 preventing backflow.

  Hot water supply pipes 26 and 27 constituting a hot water supply passage 25 are connected to the upper part of the first hot water storage tank 16 and the upper part of the second hot water storage tank 17, and these hot water supply pipes 26 and 27 are connected to one by way of the mixing valve 28. It is connected to a hot water supply pipe 29. The mixing valve 28 can adjust the mixing ratio of the hot water taken out from the first hot water storage tank 16 and the hot water taken out from the second hot water storage tank 17, and one of the mixing ratios that can be adjusted is 100%. The case where 0 is 0% is also included. The mixing valve 28 or the hot water supply pipe 29 is provided with a temperature sensor 30 that detects the temperature of the hot water mixed by the mixing valve 28.

  Further, the hot water supply pipe 29 and the water supply path 20 of the hot water supply path 25 are respectively connected to a mixing valve 34 for hot water supply and a mixing valve 35 for a bathtub. These mixing valves 34 and 35 mix hot water from the hot water supply pipe 29 and water from the water supply channel 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 pipe 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 backflow to the hot water supply pipe 29 side and the water supply path 20 side, respectively.

  The hot water mixing valve 34 supplies hot water having a set hot water 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 pipe 38 for supplying hot water to a predetermined hot water supply place is connected to the mixing valve 34 for hot water supply. The hot water supply pipe 38 is provided with a flow rate sensor 39 for measuring the flow rate and a temperature sensor 40 for detecting the hot water supply temperature. Yes.

  The mixing valve 35 for the bathtub supplies hot water at a hot water 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, etc. Supply hot water at a temperature according to the ability to repel water. The mixing valve 35 for the bathtub is connected with a hot water supply passage 41 for supplying hot water to the bathtub 14, and the hot water supply passage 41 for bathtub is provided with a temperature sensor 42 for detecting the hot water supply temperature and a water supply electromagnetic valve for opening and closing the flow passage. A provided hopper 43 is provided.

  Further, on the downstream side of the connection point of the mixing valves 34 and 35 of the hot water supply pipe 29, there is a check valve 44 for restricting the backflow to the upstream side, and a memorial for exchanging heat with the bath water of the bathtub 14 on the heat load side. A return pipe 46 for replenishment for returning the hot water that has passed through the heat exchanger 45 for replenishment to the lower part of the second hot water storage tank 17 is connected via the heat exchanger 45 for recreation. In the return pipe 46 for remedy, after the hot water in the upper part of the first hot water storage tank 16 (or the second hot water storage tank) is taken out from the hot water supply passage 25 and passed through the heat exchanger 45 for remedy, A recirculation circulation pump 47 for circulating hot water is disposed so as to return from the return pipe 46 to the lower part of the second hot water storage tank 17.

  A chasing circuit 48 is configured including the hot water supply path 25, the chasing heat exchanger 45, the chasing circulation pump 47, the chasing return pipe 46, and the like.

  In addition, the memorial heat exchanger 45 and the bathtub 14 are connected by a circulation circuit 54 for the bathtub. The bathtub circulation circuit 54 takes in the bathtub water of the bathtub 14 and leads it to the heat exchanger 45 for bathing, and returns the bathtub water that passes through the heat exchanger 45 for bathing to the bathtub 14. A forward pipe 56 is provided. The return pipe 55 for the bathtub has a temperature sensor 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, and a switch for switching the flow path when automatically filling the bathtub 14. A valve 59, a bath circulation pump 60 for circulating the bath water, and a flow switch 61 for detecting the bath water circulation are provided. The bathtub forward pipe 56 is provided with a temperature sensor 62 for detecting the temperature of the bathtub water introduced into the bathtub 14.

  Bathtub hot water supply passage 41 is connected to switching valve 59, and hot water supplied from bathtub hot water supply passage 41 is supplied as one pipe of bathtub return pipe 55 or two pipes of bathtub return pipe 55 and bathtub forward pipe 56. Hot water can be supplied to the tub 14 through.

  The hot water supply pipe 26 of the first hot water storage tank 16 is connected to a relief valve 65 that releases excessive pressure during boiling, and this relief valve 65 is connected to a drain pipe 66 that drains to the outside.

  The hot water storage tanks 16 and 17 of the tank unit 12 and the heat pump unit 13 are connected by a boiling circuit 70. The boiling circuit 70 connects the lower piping of the second hot water storage tank 17 and the inlet side of the heat pump unit 13, and connects the outlet side 71 of the heat pump unit 13 and the hot water storage tanks 16 and 17. Boiling return pipe 72, disposed in the heat pump unit 13, and disposed in the heat pump unit 13, the boiling circulation pump 73 for taking out water from the lower part of the second hot water storage tank 17 and circulating it in the boiling circuit 70 A boiling heat exchanger 74 and a four-way valve 75 as switching means provided in the boiling return pipe 72 are provided.

  The downstream side of the return pipe 72 for boiling is connected to the first return pipe section 76 connected to the upper part of the first hot water storage tank 16 and the upper part of the second hot water storage tank 17 via a four-way valve 75. The second return pipe section 77 and the third return pipe section 78 connected to the lower part of the second hot water storage tank are branched. A remedy return pipe 46 is connected to the upstream side of the boiling return pipe 72.

  The four-way valve 75 switches so that any one of the first to third return pipe sections 76 to 78 on the downstream side is connected to the upstream side of the return pipe 72 for boiling.

  In addition, below the hot water storage tanks 16 and 17, a water distribution pipe 81 for draining the water in the hot water storage tanks 16 and 17 to the outside and a drain valve 82 for opening and closing the drain pipe 81 are disposed.

  Further, the heat pump unit 13 has a refrigerant circuit including a boiling heat exchanger 74 functioning as a compressor and a condenser, an expansion valve, an evaporator, and the like. A boiling circuit 70 is connected to the boiling heat exchanger 74 of the heat pump unit 13.

  Further, the hot water supply device 11 includes a control unit 91 that controls the operation of the hot water supply device 11. The controller 91 stores hot water in the hot water storage tanks 16 and 17 by the heat pump unit 13 and the boiling circuit 70 during hot water storage operation in a predetermined time zone. On the other hand, when supplying hot water, Hot water stored in the hot water storage tank 17 is preferentially supplied, and there is no hot water that can be used for hot water as it is in the upper part of the second hot water storage tank 17 so that the hot water temperature is higher than the hot water temperature but cannot be used for hot water supply. If it is detected that the hot water supply temperature is set to 42 ° C., 35 to 40 ° C. becomes medium hot water that cannot be used for hot water supply as it is, and the hot water at the top of the first hot water storage tank 16 and the second The hot water in the upper part of the hot water storage tank 17 is mixed with hot water to supply hot water, and it is detected that the upper part of the second hot water storage tank 17 has become water from the intermediate hot water, and the lower part in the first hot water storage tank 16 If it is detected that there is medium temperature water in The over preparative pump unit 13 and Niejo circuit 70 to the hot water storage a predetermined amount of hot water on top of the second hot-water tank 17, and has a function of hot water from only the first of the hot water storage tank 16.

  In addition, when it is detected that the upper part of the second hot water storage tank 17 has changed from medium temperature water to water, there may be a case where the temperature sensor S4 has water around it but a part of the medium temperature water remains above it. is there. At the time of detection, the heat pump unit 13 and the boiling circuit 70 may start hot water storage for the upper portion of the second hot water storage tank 17, or after a predetermined amount of hot water has been supplied from the time of detection, that is, the second hot water storage tank 17 After the medium-temperature water has completely disappeared in the upper part of the hot water, hot water storage for the upper part of the second hot water storage tank 17 may be started by the heat pump unit 13 and the boiling circuit 70.

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

  First, hot water storage operation will be described.

  When a hot water storage operation (boiling operation) is started as a specific time zone, for example, in the nighttime zone of the hourly lighting system, the heat pump unit 13 is activated and the 4-way valve 75 of the boiling circuit 70 returns for boiling. Switching is made so that the upstream side of the pipe 72 is connected to the first return pipe section 76, and the boiling circulation pump 73 is operated.

  Thereby, in the boiling circuit 70, water is taken out from the lower part of the second hot water storage tank 17 and sent to the heat pump unit 13, and the hot water boiled by the heat pump unit 13 is sent to the four-way valve 75 and the first return pipe 76. To the top of the first hot water storage tank 16.

  In the first hot water storage tank 16, hot water and water formed between the hot water on the upper side of the first hot water tank 16 and the water on the lower side due to the specific gravity difference between the hot water and water having different temperatures. Hot water is stored in order from the upper side in the first hot water storage tank 16 without mixing hot water and water through the mixed layer.

  Even if the temperature sensor S3 detects that hot water has been stored up to the lower part of the first hot water storage tank 16, the hot water storage operation is continued and the hot water is sequentially supplied from the upper side of the second hot water storage tank 17 through the connecting pipe 18. Or when the temperature sensor S3 detects that hot water has been stored up to the bottom of the first hot water storage tank 16, the return pipe for boiling is returned by the four-way valve 75 of the boiling circuit 70. 72 so that the upstream side of 72 and the second return pipe 77 are connected to each other, and the hot water boiled by the heat pump unit 13 is transferred to the upper part of the second hot water storage tank 17 through the four-way valve 75 and the second return pipe 77. The hot water may be stored in order from the upper side of the second hot water storage tank 17.

  When it is detected by the temperature sensor S6 that hot water has been stored up to the bottom of the second hot water storage tank 17, the hot water storage operation is stopped.

  Next, use of the bathtub 14 will be described.

  When it is detected by the temperature sensor S4 or the like that there is hot water of a predetermined temperature or more that can be used for hot water supply in the second hot water storage tank 17, the mixing valve 28 of the hot water supply path 25 has priority from the second hot water storage tank 17. The hot water supply is switched.

  To fill the bathtub 14 with hot water, the hot water in the upper part of the second hot water storage tank 17 is pushed out by the water supply pressure by opening the water supply electromagnetic valve of the hopper 43 and sent from the second hot water storage tank 17 through the hot water supply passage 25. The hot water supplied and the water supplied from the water supply channel 20 are mixed by the mixing valve 35 for the bathtub to obtain a hot water having a preset hot water temperature, and this hot water is supplied to the bathtub 14 through the hot water supply channel 41 for the bathtub and the circulation circuit 54 for the bathtub. Hot water supply.

  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 circuit 54 for the bathtub, and the temperature sensor 57 Detect and monitor whether there is a need for heat insulation, that is, a chasing action.

  When the temperature of the bathtub water falls below the set temperature, it automatically retreats, or retreats by manual operation such as a bathtub remote controller.

  In the reheating operation, first, the bathtub circulation pump 60 is operated, and the bathtub water is taken into the bathtub circulation circuit 54 and circulated to the reheating heat exchanger 45. In this state, the hot water circulation pump 47 is operated to take out hot water from the second hot water storage tank 17 and send it to the hot water heat exchanger 45 through the hot water supply passage 25. In this hot water heat exchanger 45, Heat is exchanged between the hot water taken out and the bathtub water from the bathtub 14, and the bathtub water whose temperature has been raised by this heat exchange is returned to the bathtub 14 and the hot water temperature in the bathtub 14 is raised.

  The hot water whose temperature has dropped after passing through the heat exchanger 45 for reheating is added to the second hot water storage tank 17 through the return piping 46 for reheating, the return piping 72 for boiling, the four-way valve 75 and the third return piping section 78. Return to the bottom.

  As a result, the temperature of the hot water in the second hot water storage tank 17 is lowered, and when there is no hot water in the second hot water storage tank 17 exceeding a predetermined temperature that can be used for reheating, the first hot water storage tank 16 Remove hot water from

  Therefore, the second hot water storage tank 17 can be used for hot water and hot water whose temperature is lower than that of hot water depending on the situation such as the use of hot water for hot water, the use of hot water for hot water supply, and the heat dissipation of hot water. Hot water of a predetermined temperature or higher that can be used as it is, medium-temperature water that is lower than a predetermined temperature that cannot be used as it is for hot water supply, and water at a water supply temperature form a layer and accumulate.

  Next, the hot water supply operation will be described.

  When it is detected by the temperature sensor S4 that the second hot water storage tank 17 has hot water of a predetermined temperature or higher that can be used for hot water supply, the mixing valve 28 of the hot water supply path 25 is given priority from the second hot water storage tank 17. It is in the switching state to supply hot water.

  By opening a hot water tap or the like disposed on the downstream side of the hot water supply pipe 38, the hot water in the upper part of the second hot water storage tank 17 is pushed out by the hot water pressure and sent from the second hot water storage tank 17 through the hot water supply passage 25. Hot water and water supplied from the water supply channel 20 are mixed by a mixing valve 34 for hot water supply to obtain hot water having a predetermined hot water supply temperature, and this hot water is supplied from a hot water supply pipe 38.

  If the temperature sensor S4 detects that there is no hot water above a predetermined temperature that can be used for hot water supply in the upper part of the second hot water storage tank 17 and there is medium hot water that is higher than the water supply temperature but cannot be used as it is for hot water supply. The hot water at the upper part of the first hot water storage tank 16, that is, hot water and hot water of the second hot water storage tank 17 are used to supply hot water. That is, the hot water in the upper part of the first hot water storage tank 16 and the intermediate hot water in the upper part of the second hot water storage tank 17 are mixed by the mixing valve 28 of the hot water supply passage 25 and set to a predetermined temperature based on the detection of the temperature sensor 30. Hot water is supplied to the mixing valve 34. As a result, the intermediate temperature water can be reduced while effectively using the amount of heat of the intermediate temperature water in the second hot water storage tank 17.

  At this time, in order to supply hot water from the first hot water storage tank 16, the medium temperature water in the upper part of the second hot water storage tank 17 flows into the lower part of the first hot water storage tank 16 and accumulates.

  Therefore, as the hot water supply proceeds, as shown in FIG. 2, there is no medium-temperature water in the upper part of the second hot water storage tank 17, and all the water in the second hot water storage tank 17 becomes water (B5 to B in FIG. 2). The white display area of B8 is water), and there is hot water at the top of the first hot water storage tank 16 and medium hot water at the bottom (the black display areas of B1 to B3 shown in FIG. 2 are hot water and the gray of B4 The display area is in the middle hot water state.

  When the state shown in FIG. 2 is reached, it has been impossible to reduce or eliminate the medium-temperature water in the past. However, in the present embodiment, if it is detected that the state shown in FIG. As shown in FIG. 3 (the pipe through which hot water flows is displayed in black, the black display of this pipe is not related to temperature), the hot water storage operation (boiling operation) is started, and the upper part of the second hot water storage tank 17 By storing a predetermined amount of hot water in the hot water, medium hot water can be eliminated.

  In the hot water storage operation (boiling operation), the heat pump unit 13 is operated, and the four-way valve 75 of the boiling circuit 70 is switched so that the upstream side of the return piping 72 for boiling and the second return piping section 77 are connected. At the same time, the circulating pump 73 for boiling is operated.

  Thereby, water is taken out from the lower part of the second hot water storage tank 17 and sent to the heat pump unit 13, and the hot water boiled by the heat pump unit 13 is passed through the four-way valve 75 and the second return pipe 77 to the second hot water storage tank. Return to the top of 17.

  In the second hot water storage tank 17, due to the specific gravity difference between the high temperature hot water and water having different temperatures, a mixed layer formed between the high temperature hot water on the upper side of the second hot water storage tank 17 and the water on the lower side is used. Thus, the hot water is stored in order from the upper side in the second hot water storage tank 17 without mixing the hot water and water. At this time, since the temperature difference between the boiled hot water and the water at the feed water temperature is large, the layer width of the mixed layer can be reduced.

  For example, when the temperature sensor S4 detects that a predetermined amount of hot water has been stored in the upper part of the second hot water storage tank 17, the hot water storage operation is stopped.

  When the state shown in FIG. 2 is reached, the hot water supply passage 25 is switched to supply hot water only from the first hot water storage tank 16 by the mixing valve 28.

  Then, as shown in FIG. 4 (the piping through which hot water flows is displayed in black, the black display of this piping is not related to temperature), by opening a hot water tap or the like disposed on the downstream side of the hot water supply pipe 38 The hot water in the upper part of the second hot water storage tank 17 is pushed out from the connecting pipe 18 to the lower part of the first hot water storage tank 16 by the feed water pressure, and the hot water in the upper part of the first hot water storage tank 16 is pushed out into the hot water supply path 25. Hot water sent through the channel 25 and water supplied from the water supply channel 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 pipe 38.

  With such hot water supply, the hot water in the upper part of the second hot water storage tank 17 flows into the lower part of the first hot water storage tank 16, so that the hot water is mixed with the intermediate hot water in the lower part of the first hot water storage tank 16. The temperature of the medium temperature water rises, and the medium temperature water can be used as hot water at a predetermined temperature or higher that can be used as it is for hot water supply.

  If there is 30 L of 35 ° C. hot water in the lower part of the first hot water storage tank 16 and 30 L of hot water of 85 ° C. in the upper part of the second hot water storage tank 17, intermediate hot water of the first hot water storage tank 16 is assumed. The amount of heat (1050 kcal) + the amount of heat of the hot water in the second hot water storage tank 17 (2550 kcal) = 3600 kcal, so 3600 kcal / 60L = 60 ° C, and the medium-temperature water that cannot be used as it is for 35 ° C hot water is converted to 60 ° C (60L) hot water The temperature rises.

  In this way, since the medium-temperature water can be heated to a predetermined temperature or higher that can be used as it is for hot water supply, the amount of hot water that can be used for hot water supply can be increased.

  In addition, during the hot water storage operation (boiling operation) in the night time period of the electric lamp system according to the time zone thereafter, the hot water is not boiled by the heat pump unit 13, and a decrease in the boiling efficiency can be prevented.

  Although the four-way valve 75 is provided in the boiling return pipe 72 of the boiling circuit 70 and the first to third return pipe portions 76 to 78 are switched, the present invention is not limited to this. An opening / closing valve may be provided in the return piping sections 76 to 78 to selectively open any one of them.

  Moreover, in the said embodiment, although the example which applied this invention when two hot water storage tanks were connected in series was shown, this invention is applied similarly when three or more hot water storage tanks are connected in series. it can.

  For the purpose of eliminating the medium temperature water that cannot be used for hot water supply as it is in the first hot water storage tank 16, the capacity may be reduced by using the second hot water storage tank 17 as an auxiliary tank, and the size and cost can be reduced. .

It is a lineblock diagram of a hot-water supply device showing one embodiment of the present invention. It is a block diagram which shows the state which has hot water in the upper part of the 1st hot water storage tank of the same hot-water supply apparatus, and medium temperature water in the lower part, respectively. It is a block diagram which shows the state which stores hot water in the upper part of the 2nd hot water storage tank of a hot-water supply apparatus same as the above. It is a block diagram which shows the state which the hot water of the upper part of a 2nd hot water storage tank flowed into the 1st hot water storage tank by the hot water supply of the same hot water supply apparatus.

Explanation of symbols

11 Water heater
13 Heat pump unit
16, 17 Hot water storage tank
18 Connection piping
20 Waterway
25 Hot water supply path
70 Boiling circuit
91 Control unit
S1 ~ S6 Temperature sensor

Claims (2)

Multiple hot water tanks,
A connection pipe for connecting in series the lower part of the hot water storage tank of the higher order side and the upper part of the lower side hot water storage tank;
A plurality of temperature sensors for detecting the temperature of hot water in the hot water storage tank at a plurality of different height positions in the vertical direction of each hot water storage tank;
A water supply channel that supplies water to the lower part of the hot water storage tank with the lowest connection order,
A heat pump unit used for boiling water,
A boiling circuit that takes out water from the lower part of the hot water storage tank having the lowest connection order and sends it to the heat pump unit, and switches the hot water boiled up by the heat pump unit back to one of the upper parts of the plurality of hot water storage tanks;
A hot water supply path that allows hot water to be switched from any of the upper parts of the plurality of hot water storage tanks;
In a state where hot water is switched from the upper part of the hot water storage tank with the highest connection order, it is detected that there is water in the upper part of the hot water storage tank next to the highest connection order, and the upper part of the uppermost hot water storage tank. If it is detected that hot water of a predetermined temperature or higher that can be used as it is for hot water supply is stored and that there is medium temperature water below the predetermined temperature that is higher than the supply water temperature but cannot be used as it is for hot water supply, the heat pump unit And a controller for storing a predetermined amount of hot water in the upper part of the next hot water storage tank by the boiling circuit. The control unit
During hot water storage operation in a specific time zone, hot water is stored in multiple hot water storage tanks using a heat pump unit and boiling circuit,
During hot water supply
Hot water stored in the hot water storage tank on the lower side is supplied by the hot water supply channel,
If it is detected that there is no hot water in the upper part of the next hot water storage tank when the hot water is supplied from the next hot water storage tank, and the medium hot water is detected, the hot water at the upper part of the uppermost hot water storage tank and the hot water of the next order are detected by the hot water supply path. Mix with the warm water at the top of the tank to supply hot water,
If it is detected that the upper part of the next hot water storage tank has changed from medium temperature water to water, and if it is detected that there is intermediate temperature water in the lower part of the uppermost hot water storage tank, the heat pump unit and the boiling circuit The hot water supply apparatus according to claim 1, wherein a predetermined amount of hot water is stored in an upper part of a next hot water storage tank by the hot water supply, and hot water is supplied from only the uppermost hot water storage tank through the hot water supply passage.

Images