JP5617946B2 - Hot water storage water heater - Google Patents

Description

  The present invention relates to a hot water storage type hot water supply apparatus.

  In Patent Document 1, hot water heated by a heat pump device is stored in the upper part of a hot water storage tank at midnight, and intermediate temperature hot water heated by a heat pump device is stored in an intermediate part of the hot water tank in the daytime. A heat pump type hot water supply apparatus is disclosed in which the hot water is discharged from the intermediate temperature hot water when the hot water is discharged from the hot water storage tank during use.

JP 2006-23064 A

  When performing operation to generate hot water in a refrigeration cycle, generally, the lower the temperature of heated water after heating (hereinafter referred to as “heated temperature”), the higher the operating efficiency, and the higher the temperature after heating, the lower the operating efficiency. . In the device of Patent Document 1, by performing an operation of storing hot water during the daytime, by lowering the temperature after heating compared to midnight, compared with the case where all hot water is stored in the hot water storage tank with hot water. Improving efficiency.

  In the device of Patent Document 1, hot water is stored only in the upper part of the hot water storage tank at midnight, and between hot water stored in the upper part of the hot water storage tank and water stored in the lower part in the daytime. Since hot water of medium temperature is stored, hot water can be stored in order from the top without disturbing the layer of hot water, medium temperature hot water, and water (see paragraph 0059 of Patent Document 1). However, in the apparatus of Patent Document 1, hot water is stored only in the upper part of the hot water storage tank at midnight, so that the amount of heat stored in the hot water storage tank can be reduced during the midnight when the power cost is low. For this reason, the amount of heat that must be generated during the daytime when the power cost is high increases, resulting in a high power charge.

  Moreover, in the apparatus of patent document 1, the temperature of the intermediate temperature water produced | generated in the daytime is 50 degreeC-65 degreeC (refer paragraph 0068 of patent document 1). Thus, when the temperature after heating is about 50 ° C. to 65 ° C., the improvement in efficiency is not necessarily sufficiently large.

  The present invention has been made to solve the above-described problems, and can store a large amount of heat in a hot water storage tank, improve the operation efficiency of the apparatus, and can be operated at low cost. An object is to provide a hot water supply apparatus.

  The hot water storage type hot water supply apparatus according to the present invention is made to flow out of a heating means for heating water, a hot water storage tank for stratifying and storing water having different temperatures so that the upper side is hot and the lower side is low temperature, and the hot water storage tank. A first hot water storage path for sending water to the heating means, and allowing the hot water heated by the heating means to flow into the hot water storage tank from the upper inlet provided in the upper part of the hot water storage tank, and the water discharged from the hot water storage tank to the heating means A second hot water storage path for feeding hot water heated by the feeding means and flowing into the hot water storage tank from an intermediate inlet provided at a position lower than the upper inlet of the hot water storage tank, and an upper portion provided above the hot water storage tank Hot water flowing out from the outlet, hot water flowing out from the intermediate outlet provided at a position lower than the upper outlet of the hot water tank, and low temperature water supplied from the lower part of the hot water tank or outside A hot water supply path capable of hot water mixing by mixing at least two, and a hot water temperature setting means that allows a user to set the temperature of the hot water discharged from the hot water supply path, and heating when performing hot water storage operation in the first hot water storage path When the temperature of the hot water on the outlet side of the means is set higher than the set temperature of the hot water temperature setting means, and the hot water storage operation is performed in the second hot water storage path, the temperature of the hot water on the outlet side of the heating means is higher than the set temperature. To lower.

  According to the present invention, it is possible to store a large amount of heat in the hot water storage tank, improve the operation efficiency of the apparatus, and operate at a low cost.

It is a block diagram which shows the hot water storage type hot water supply apparatus of Embodiment 1 of this invention. It is a figure which shows typically the daily change of the temperature distribution in the hot water storage tank in the hot water storage type hot water supply apparatus of this Embodiment 1. FIG.

  Embodiments of the present invention will be described below with reference to the drawings. In addition, the same code | symbol is attached | subjected to the element which is common in each figure, and the overlapping description is abbreviate | omitted.

Embodiment 1 FIG.
FIG. 1 is a configuration diagram illustrating a hot water storage type hot water supply apparatus according to Embodiment 1 of the present invention. As shown in FIG. 1, the hot water storage type hot water supply apparatus 1 according to the first embodiment includes a heat pump unit 10 as a heating means for heating water and a tank unit 2 in which a hot water storage tank 7 is built. The heat pump unit 10 and the tank unit 2 are connected via a water pipe and electrical wiring (not shown).

  In the heat pump unit 10, a compressor 3 that compresses the refrigerant, a water refrigerant heat exchanger 4 that heats water by the heat of the refrigerant, an expansion valve 5 that expands the refrigerant, and air that causes the refrigerant to absorb heat from the air. A heat exchanger 6 and a blower 15 for blowing air to the air heat exchanger 6 are mounted. The compressor 3, the water refrigerant heat exchanger 4, the expansion valve 5, and the air heat exchanger 6 are connected in an annular shape via a refrigerant pipe to constitute a refrigeration cycle. In the heat pump unit 10, a measurement control device 11a that performs measurement and control in the heat pump unit 10 is further mounted.

  The compressor 3 is preferably of a type in which the rotation speed is controlled by an inverter and the capacity is controlled. The water-refrigerant heat exchanger 4 is preferably a plate-type or double-pipe heat exchanger, and the inflowing refrigerant and water exchange heat. The expansion valve 5 is preferably an electronic expansion valve whose opening degree is variable. The air heat exchanger 6 exchanges heat between the outside air blown by the blower 15 and the refrigerant.

  In the tank unit 2, there are a hot water storage tank 7, a pump 8 for circulating hot water, a flow path switching valve 9 a, a mixing valve 9 b, a mixing valve 9 c, a mixing valve 9 d, an electromagnetic valve 14, and a tank unit 2. And a measurement control device 11b for performing measurement and control. In the hot water storage tank 7, hot water can be stratified and stored so that the upper side is hot and the lower side is cold. The pump 8 is preferably of a type in which the rotational speed is controlled by an inverter and the capacity is controlled. The measurement control device 11b is connected to the measurement control device 11a of the heat pump unit 10 so that they can communicate with each other.

  An upper outlet 7 a is provided at the upper part of the hot water storage tank 7. An intermediate part inlet 7b and an intermediate part outlet 7c are provided at a position lower than the upper outlet 7a of the hot water storage tank 7. The intermediate part inflow port 7 b and the intermediate part outflow port 7 c are provided at substantially the same height in the intermediate part of the hot water storage tank 7. A lower outlet 7d and a lower inlet 7e are provided at the lower part of the hot water storage tank 7. The lower outlet 7 d of the hot water storage tank 7 and the suction port of the pump 8 are connected via a pipe 16. The discharge port of the pump 8 and the water inlet of the water / refrigerant heat exchanger 4 are connected via a pipe 17. The water outlet of the water-refrigerant heat exchanger 4 and the inlet of the flow path switching valve 9a are connected via a pipe 18. The first outlet of the flow path switching valve 9 a and the upper outlet / inlet 7 a of the hot water storage tank 7 are connected via a pipe 19. The second outlet of the flow path switching valve 9 a and the intermediate inlet 7 b of the hot water storage tank 7 are connected via a pipe 20.

  In the hot water storage type hot water supply apparatus 1 according to the first embodiment, a first hot water storage path and a second hot water storage path that circulate through the heat pump unit 10 and the tank unit 2 can be formed. The first hot water storage path starts from the lower outlet 7d of the hot water storage tank 7 and passes through the pipe 16, the pump 8, the pipe 17, the water / refrigerant heat exchanger 4, the pipe 18, the flow path switching valve 9a, and the pipe 19 to store the hot water. The structure reaches the upper outlet / inlet 7 a of the tank 7. The second hot water storage path starts from the lower outlet 7d of the hot water storage tank 7 and passes through the pipe 16, the pump 8, the pipe 17, the water / refrigerant heat exchanger 4, the pipe 18, the flow path switching valve 9a, and the pipe 20 to store the hot water. The structure reaches the intermediate part inlet 7b of the tank 7. Switching between the first hot water storage path and the second hot water storage path is performed by switching the flow path of the flow path switching valve 9a.

  A water supply pipe 21 for supplying low temperature water such as city water from the outside is connected to the tank unit 2. The water supply pipe 21 is connected to the lower inlet 7 e of the hot water storage tank 7. Water passing through the water supply pipe 21 flows into the hot water storage tank 7 from the lower inlet 7e.

  Further, in the hot water storage type hot water supply apparatus 1 according to the first embodiment, the hot water supply route for the hot water supply to the bathtub 50 and the hot water supply terminal 60 such as a shower, a currant, a sink, a wash basin, etc. And a hot water supply route. The configuration of the hot water filling route and the hot water supply route will be described. The pipe 22 branched from the middle of the pipe 19 is connected to the first inlet of the mixing valve 9b. The second inlet of the mixing valve 9 b and the intermediate outlet 7 c of the hot water storage tank 7 are connected via a pipe 23. One end of a pipe 24 is connected to the outlet of the mixing valve 9b. The other end of the pipe 24 branches into two and is connected to the first inlet of the mixing valve 9c and the first inlet of the mixing valve 9d. The end of the feed water branch pipe 25 branched from the feed water pipe 21 is branched into two and connected to the second inlet of the mixing valve 9c and the second inlet of the mixing valve 9d. The outlet of the mixing valve 9 c is connected to the bathtub 50 through the pipe 26. A solenoid valve 14 is provided in the middle of the pipe 26. The outlet of the mixing valve 9 d is connected to the hot water supply terminal 60 via the pipe 27. In the first embodiment, the low temperature water from the water supply branch pipe 25 branched from the water supply pipe 21 is supplied to the mixing valve 9c and the mixing valve 9d, but the lower temperature in the hot water storage tank 7 is low. You may comprise so that water may be supplied to the mixing valve 9c and the mixing valve 9d.

  The hot water filling path is such that high temperature water flowing out from the upper outlet / inlet 7a of the hot water storage tank 7 and medium temperature water flowing out from the intermediate outlet 7c are mixed by the mixing valve 9b and then further cooled by the mixing valve 9c. And can be discharged into the bathtub 50 through the electromagnetic valve 14. In the hot water filling path, the temperature of the hot water supplied to the bathtub 50 can be controlled by adjusting the mixing ratio in the mixing valve 9b and the mixing ratio in the mixing valve 9c.

  The hot water supply path is such that high temperature water flowing out from the upper outlet / inlet 7a of the hot water storage tank 7 and medium temperature water flowing out from the intermediate outlet 7c are mixed by the mixing valve 9b, and further mixed with low temperature water by the mixing valve 9d. It can be mixed and discharged to the hot water supply terminal 60. In the hot water supply path, the hot water temperature to the hot water supply terminal 60 can be controlled by adjusting the mixing ratio in the mixing valve 9b and the mixing ratio in the mixing valve 9d.

  The heat pump unit 10 is provided with a pressure sensor 12 a that measures the pressure on the discharge side of the compressor 3 and a pressure sensor 12 b that measures the pressure on the suction side of the compressor 3. The heat pump unit 10 is provided with a temperature sensor 13 a that measures the temperature on the discharge side of the compressor 3 and a temperature sensor 13 b that measures the temperature on the suction side of the compressor 3.

  The tank unit 2 includes a temperature sensor 13c for measuring the temperature of hot water passing through the pipe 18, a temperature sensor 13d for measuring the temperature of hot water passing through the pipe 24 on the downstream side of the mixing valve 9b, and a mixing valve 9c for a hot water filling path. A temperature sensor 13e that measures the temperature of hot water that passes through the downstream pipe 26 and a temperature sensor 13f that measures the temperature of hot water that passes through the pipe 27 on the downstream side of the mixing valve 9d in the hot water supply path are provided. The temperature measured by the temperature sensor 13c corresponds to the temperature of hot water on the outlet side of the heat pump unit 10 (water refrigerant heat exchanger 4). Moreover, several temperature sensors 13g-13k are provided in the mutually different height position from the upper part of the hot water storage tank 7, and the water temperature in the hot water storage tank 7 in each installation height position is measured. Among these, the temperature sensor 13 h (intermediate temperature measuring means) is provided at the same height as the intermediate inlet 7 b and the intermediate outlet 7 c of the hot water storage tank 7.

  A remote control device 30 is connected to the hot water storage type hot water supply device 1 of the first embodiment as a user interface device. The remote control device 30 is installed in a bathroom or kitchen, and is connected to the measurement control device 11b in the tank unit 2 so as to communicate with each other. The user of the hot water storage type hot water supply device 1 can instruct the operation contents and the like by operating the remote control device 30. For example, the user sets the hot water filling temperature of the bathtub 50, sets the hot water supply temperature to the hot water supply terminal 60, or reserves the time when the hot water filling is automatically performed on the bathtub 50 by operating the remote controller 30. You can do it.

  The measurement control device 11a in the heat pump unit 10 is based on the measurement information of the pressure sensors 12a and 12b and the temperature sensors 13a and 13b, the operation content instructed by the user, and the like. And the air flow rate of the blower 15 are controlled.

  The measurement control device 11b in the tank unit 2 is based on the measurement information of the temperature sensors 13c to 13k, the operation content instructed by the user, etc., the operation method of the pump 8, the channel switching of the channel switching valve 9a, The opening degree (mixing ratio) of the mixing valves 9b to 9d and the opening / closing of the electromagnetic valve 14 are controlled.

  Next, the operation of the hot water storage type hot water supply apparatus 1 will be described. The hot water storage type hot water supply apparatus 1 can perform a first hot water storage operation, a second hot water storage operation, a hot water filling operation, and a hot water supply operation.

  First, the operation of the first hot water storage operation and the second hot water storage operation will be described. The first hot water storage operation and the second hot water storage operation are selectively performed by switching the flow path of the flow path switching valve 9a. The first hot water storage operation is performed by the first hot water storage path. The second hot water storage operation is performed by the second hot water storage path. In the first hot water storage operation and the second hot water storage operation, the compressor 3 and the pump 8 are driven as operations common to both, and the pump 8 transfers the low temperature water in the lower portion of the hot water storage tank 7 to the heat pump unit 10. Heating is performed by the water refrigerant heat exchanger 4 in the heat pump unit 10. In the heat pump unit 10, the high-temperature and high-pressure gas refrigerant boosted by the compressor 3 flows into the water-refrigerant heat exchanger 4, and is cooled by heat radiation while heating the low-temperature water flowing into the water-refrigerant heat exchanger 4. It becomes a refrigerant. Thereafter, the refrigerant is depressurized by the expansion valve 5 to become a low-pressure two-phase refrigerant, absorbs heat from the outside air by the air heat exchanger 6, evaporates, becomes a low-pressure low-temperature gas, and is sucked into the compressor 3.

  The low temperature water in the lower part of the hot water storage tank 7 flows out from the lower outlet 7d, is conveyed by the pump 8, heated by the water / refrigerant heat exchanger 4, and then returned to the hot water storage tank 7. The process of returning to the hot water storage tank 7 is different between the first hot water storage operation and the second hot water storage operation. In the first hot water storage operation, hot water heated by the water / refrigerant heat exchanger 4 flows into the hot water storage tank 7 from the upper outlet / inlet 7a. In the second hot water storage operation, hot water heated by the water-refrigerant heat exchanger 4 flows into the hot water storage tank 7 from the intermediate part inlet 7b.

  When the first hot water storage operation is performed, in the hot water storage tank 7, high temperature water (hot water) is retained in the upper portion and low temperature water is retained in the lower portion to form a temperature stratification, and a temperature boundary layer is formed between the high temperature water and the low temperature water. Is generated. As the first hot water storage operation proceeds, the ratio of the low temperature water decreases, the ratio of the high temperature water increases, and the temperature boundary layer moves downward of the hot water storage tank 7.

  When the second hot water storage operation is performed, in the hot water storage tank 7, the hot water flowing from the intermediate part inlet 7 b stays downward from the intermediate part inlet 7 b, and the low temperature water stays in the lower part of the hot water tank 7. A stratification is formed, and a temperature boundary layer is generated between the hot water and the low-temperature water. As the second hot water storage operation proceeds, the ratio of the low temperature water decreases, the ratio of the hot water increases, and the temperature boundary layer moves downward of the hot water storage tank 7. In addition, when high-temperature water has already been stored below the intermediate inlet 7b before the second hot water storage operation is performed, the hot water flowing from the intermediate inlet 7b is performed when the second hot water storage operation is performed. And hot water mixed with hot water in the hot water storage tank 7 stays downward from the intermediate inlet 7b. Then, as the second hot water storage operation proceeds, the ratio of the mixed hot water increases and the ratio of the low temperature water below the hot water storage tank 7 decreases.

  In the first embodiment, the water temperature at the outlet side of the heat pump unit 10 (water refrigerant heat exchanger 4) (hereinafter referred to as “heated temperature”) in the first hot water storage operation and the second hot water storage operation. Change the setting of. In Embodiment 1, the lower limit of the temperature after heating in the first hot water storage operation is set to 65 ° C., and the upper limit of the temperature after heating in the first hot water storage operation is set to 90 ° C. In this range, the amount of hot water used is taken into consideration. Then, the temperature after heating in the first hot water storage operation is set. The lower the temperature after heating, the higher the operating efficiency of the heat pump unit 10. For this reason, when performing the most efficient operation, the temperature after heating in the first hot water storage operation is set to 65 ° C. which is the lower limit. In addition, if it is a temperature of 65 degreeC or more, even if it is a case where it stores in the hot water storage tank 7 for a long time, reproduction of Legionella bacteria can be avoided reliably.

  In the second hot water storage operation, after heating so as to be lower than this set temperature in accordance with the hot water filling temperature (or the hot water supply temperature to the hot water supply terminal 60) set by the user with the remote control device 30 as the hot water temperature setting means. The temperature is set. For example, when the set temperature of the hot water filling temperature (or the hot water supply temperature to the hot water supply terminal 60) is 42 ° C., the temperature after heating in the second hot water storage operation is set to 25 ° C., which is lower than that.

  The flow rate of water transported by the pump 8 is controlled so that the water temperature on the outlet side of the water-refrigerant heat exchanger 4 measured by the temperature sensor 13c becomes a set value of the post-heating temperature. For example, when the water temperature on the outlet side of the water-refrigerant heat exchanger 4 is lower than the set value of the temperature after heating, the operating capacity of the pump 8 is controlled to be low so that the flow rate of water conveyed by the pump 8 is reduced, When the water temperature on the outlet side of the water-refrigerant heat exchanger 4 is higher than the set value of the post-heating temperature, the operation capacity of the pump 8 is controlled to be high so that the flow rate of water conveyed by the pump 8 is increased.

  In the heat pump unit 10, the capacity control of the compressor 3 and the opening degree control of the expansion valve 5 are performed according to the set value of the temperature after heating. The capacity control of the compressor 3 is controlled so that the high pressure of the refrigeration cycle becomes a target value set according to the set value of the temperature after heating. That is, when the high pressure of the refrigeration cycle measured by the pressure sensor 12a is lower than the target value, the operating capacity of the compressor 3 is controlled to be high, and the high pressure of the refrigeration cycle measured by the pressure sensor 12a is higher than the target value. In this case, the operation capacity of the compressor 3 is controlled to be low. The opening degree control of the expansion valve 5 is controlled such that the discharge temperature of the refrigeration cycle becomes a target value set according to the set value of the post-heating temperature. That is, when the discharge temperature of the refrigeration cycle measured by the temperature sensor 13a is lower than the target value, the opening degree of the expansion valve 5 is controlled to be small, and the discharge temperature of the refrigeration cycle measured by the temperature sensor 13a is lower than the target value. If it is too high, the opening of the expansion valve 5 is largely controlled. The heat pump unit 10 performs control according to the temperature after heating in this way, and is controlled so as to perform an operation that maximizes the efficiency at each temperature after heating.

  Next, the operation of the filling operation for filling the bathtub 50 will be described. In the hot water filling operation, the opening degree of the electromagnetic valve 14 which is normally closed is opened. Next, the high temperature water flowing out from the upper outlet 7a of the hot water storage tank 7 and the medium temperature water flowing out from the intermediate outlet 7c are mixed by the mixing valve 9b. Subsequently, the mixed warm water flowing out from the mixing valve 9b and the low-temperature water supplied from the feed water branch pipe 25 are mixed by the mixing valve 9c. And the opening degree of the mixing valve 9b and the mixing valve 9c is each adjusted so that the temperature of the hot water downstream of the mixing valve 9c measured by the temperature sensor 13e becomes the hot water temperature set by the user. At this time, the mixing valve 9b may set the mixing ratio of any one of the high temperature water supplied from the upper outlet / inlet 7a of the hot water storage tank 7 and the intermediate temperature water supplied from the intermediate outlet 7c to zero. That is, the mixing valve 9b may flow only one of the high-temperature water supplied from the upper outlet / inlet 7a and the intermediate-temperature water supplied from the intermediate outlet 7c to the downstream side. Moreover, the mixing valve 9c may make the mixing ratio of the low temperature water supplied from the feed water branch pipe 25 zero.

  Next, the operation of the hot water supply operation for discharging hot water to the hot water supply terminal 60 will be described. In the hot water supply operation, high-temperature water flowing out from the upper outlet / inlet 7a of the hot water storage tank 7 and medium-temperature water flowing out from the intermediate outlet 7c are mixed by the mixing valve 9b. Subsequently, the mixed hot water flowing out from the mixing valve 9b and the low-temperature water supplied from the feed water branch pipe 25 are mixed by the mixing valve 9d. And the opening degree of the mixing valve 9b and the mixing valve 9d is adjusted so that the temperature of the hot water downstream of the mixing valve 9d measured by the temperature sensor 13f becomes the hot water supply temperature set by the user. At this time, the mixing valve 9b may set the mixing ratio of any one of the high temperature water supplied from the upper outlet / inlet 7a of the hot water storage tank 7 and the intermediate temperature water supplied from the intermediate outlet 7c to zero. That is, the mixing valve 9b may flow only one of the high-temperature water supplied from the upper outlet / inlet 7a and the intermediate-temperature water supplied from the intermediate outlet 7c to the downstream side. Moreover, the mixing valve 9d may set the mixing ratio of the low-temperature water supplied from the feed water branch pipe 25 to zero.

  In the hot water filling operation and the hot water supply operation, hot water in the hot water storage tank 7 is supplied to the outside, and the same amount of low temperature water as the supplied hot water flows into the hot water storage tank 7 from the lower inlet 7e through the water supply pipe 21. . Therefore, when the hot water filling operation or the hot water supply operation is performed, the temperature boundary layer between the hot water and the low temperature water in the hot water storage tank 7 moves upward according to the amount of hot water.

  Next, a one-day operation method in which the first hot water storage operation and the second hot water storage operation are combined in the hot water storage type hot water supply apparatus 1 of the first embodiment will be described. FIG. 2 is a diagram schematically showing a daily change in the temperature distribution in the hot water storage tank 7 in the hot water storage type hot water supply apparatus 1 of the first embodiment. In FIG. 2, the temperature of the low-temperature water flowing from the water supply pipe 21 is 9 ° C.

  FIG. 2 (e) shows a state immediately before the late-night power charge application time zone (in the first embodiment, from midnight to 7:00 the next morning), which is a time zone where the power cost is low. This state corresponds to a state at the end of the day, that is, a state in which the hot water for the day is almost finished. In the state of FIG. 2 (e), the temperature distribution in the hot water storage tank 7 is such that only a small amount of high-temperature water remains in the upper portion, and the other areas are occupied by low-temperature water flowing from the water supply pipe 21. .

  In the state of FIG. 2 (e), when the midnight power rate application time zone is reached, the first hot water storage operation is performed. In FIG. 2, it is assumed that the temperature after heating in the first hot water storage operation is set to 65 ° C. By this first hot water storage operation, high-temperature water (65 ° C.) is stored from the upper part of the hot water storage tank 7, and the temperature distribution in the hot water storage tank 7 is changed to that shown in FIG. It will be in the state of a). That is, FIG. 2 (a) shows the temperature distribution around 7:00 in the morning when the late-night electricity rate application time period ends. The first hot water storage operation is performed so that at least the region of the high-temperature water in the hot water storage tank 7 reaches a height lower than the intermediate portion inlet 7b. Thereby, in the state of FIG. 2A, the temperature boundary layer between the high temperature water and the low temperature water in the hot water storage tank 7 is at a position lower than the intermediate part inlet 7 b of the hot water storage tank 7.

  In addition, it is desirable that the amount of heat stored in the hot water storage tank 7 by the first hot water storage operation in the midnight power charge application time zone is set according to the actual amount of hot water used in the past predetermined period of the user. In that case, for example, it is preferable to perform the first hot water storage operation so that the amount of heat corresponding to about 80 to 90% of the average amount of hot water used can be stored. Moreover, the heat storage amount in the hot water storage tank 7 can be estimated from the temperature distribution in the hot water storage tank 7 that is grasped from the measured temperatures of the temperature sensors 13g to 13k.

  In the daytime period, about 10% of the total daily hot water usage is usually discharged from the hot water storage tank 7 by the hot water supply operation. The hot water in the hot water storage tank 7 is reduced by the amount of the hot water discharged, and the low temperature water flows in from the water supply pipe 21, so that the temperature distribution in the hot water storage tank 7 is as shown in FIG. In this hot water supply operation, high temperature water flowing out from the upper outlet 7a of the hot water storage tank 7 and low temperature water supplied from the water supply branch pipe 25 are mixed to discharge hot water at the hot water temperature set by the user. To be driven. That is, in this hot water supply operation, the opening of the mixing valve 9b is opened so that hot water from the upper outlet 7a of the hot water storage tank 7 flows out 100% downstream, and hot water from the intermediate outlet 7c does not flow out. Degree controlled. Further, the mixing valve 9d adjusts the mixing ratio of the high temperature water and the low temperature water by opening control so that the temperature measured by the temperature sensor 13f becomes the hot water supply temperature set by the user.

  Next, a second hot water storage operation performed before the hot water filling operation will be described. In general, bathing is performed in the evening or at night. The hot water filling to the bathtub 50 before bathing is the intensive hot water that is the largest in the day as the amount of hot water discharged from the hot water storage tank 7 and occupies about 40 to 50% of the whole. In the first embodiment, the second hot water storage operation is performed before this hot water filling. In the second hot water storage operation, the temperature after heating is set to a temperature lower than the hot water filling temperature (for example, about 42 ° C.) set by the user. In FIG. 2, the temperature after heating in the second hot water storage operation is 25 ° C. As the time for starting the second hot water storage operation, the second hot water storage operation is performed a predetermined time (for example, 1 to 2 hours) before the average time based on the past hot water filling performance of the user for a predetermined period. It is desirable to start. In addition, when automatic hot water filling is reserved, the start time of the second hot water storage operation may be determined so that the second hot water storage operation is completed by the reservation time.

  When the second hot water storage operation is performed, medium temperature water of 25 ° C. flows from the intermediate portion inlet 7 b of the hot water storage tank 7 and mixes with high temperature water of 65 ° C. originally in the hot water storage tank 7. As a result, intermediate temperature water of 45 ° C. is generated in a region having a height equal to or lower than the intermediate portion inlet 7 b in the hot water storage tank 7. Therefore, the temperature distribution in the hot water storage tank 7 is as shown in FIG. Thus, in this Embodiment 1, the high temperature water (65 degreeC in FIG. 2) in the area | region below the intermediate part inflow port 7b in the hot water storage tank 7 in the hot water storage tank 7 before the start of a 2nd hot water storage operation, The temperature of the hot water (45 ° C. in FIG. 2) generated by mixing the medium hot water (25 ° C. in FIG. 2) flowing in from the intermediate inlet 7b by the hot water storage operation 2 in the hot water storage tank 7 is determined by the user. Is set to be equal to or higher than the set hot water temperature (for example, about 42 ° C.), and the post-heating temperature and operation time of the second hot water storage operation are controlled.

  After performing the second hot water storage operation, the hot water filling operation is performed. In the hot water filling operation, the operation is performed so as to discharge hot water of 45 ° C. generated in the hot water storage tank 7 by performing the second hot water storage operation. That is, in the hot water filling operation, the hot water temperature set by the user is set by mixing 45 ° C. medium temperature water flowing out from the intermediate outlet 7c of the hot water storage tank 7 and low temperature water supplied from the feed water branch pipe 25. It is operated to take out hot water. At this time, the opening degree of the mixing valve 9b is controlled so that the medium-temperature water from the intermediate outlet 7c of the hot water storage tank 7 flows out 100% downstream and the hot water from the upper outlet 7a does not flow out. The Further, the mixing valve 9c adjusts the mixing ratio of the medium-temperature water and the low-temperature water at 45 ° C. by opening control so that the temperature measured by the temperature sensor 13e becomes the hot water temperature set by the user. Due to such hot water filling operation, the region of the medium temperature water at 45 ° C. in the hot water storage tank 7 is reduced, so that the temperature distribution in the hot water storage tank 7 after the hot water filling operation is as shown in FIG.

  Next, the hot water supply operation after the hot water filling operation will be described. In the hot water supply operation after the hot water filling operation is completed, when the intermediate hot water generated in the hot water storage tank 7 in the second hot water storage operation before the hot water filling operation still remains, the hot water is preferentially discharged. drive. Specifically, driving is performed as follows. First, when the hot water temperature at the height position of the intermediate portion outlet 7c measured by the temperature sensor 13h is higher than the hot water supply temperature set by the user (for example, the hot water temperature at the height position of the intermediate portion outlet 7c). Is 43 ° C. and the hot water temperature set by the user is 42 ° C.), the medium temperature water flowing out from the intermediate outlet 7c of the hot water storage tank 7 and the low temperature water supplied from the water supply branch pipe 25 are mixed. , It operates to discharge hot water at the hot water temperature set by the user. In this case, the opening degree of the mixing valve 9b is controlled so that the medium-temperature water flowing out from the intermediate outlet 7c of the hot water storage tank 7 flows out 100% downstream, and the hot water from the upper outlet 7a does not flow out. Is done. Further, the mixing valve 9d adjusts the mixing ratio of the medium-temperature water and the low-temperature water by opening control so that the temperature measured by the temperature sensor 13f becomes the hot water supply temperature set by the user. When the amount of medium-temperature water in the hot water storage tank 7 decreases with the hot water discharge from the intermediate portion outlet 7c, the temperature of the hot water at the height position of the intermediate portion outlet 7c decreases. Therefore, when the hot water temperature at the height of the intermediate outlet 7c measured by the temperature sensor 13h is lower than the hot water temperature set by the user, the hot water flowing out from the upper outlet 7a The hot water flowing out from the intermediate outlet 7c is mixed and discharged, and the low-temperature water supplied from the feed water branch pipe 25 is not mixed. In this case, the degree of opening of the mixing valve 9b is such that the temperature measured by the temperature sensor 13f is the hot water supply temperature set by the user and the hot water from the upper outlet 7a and the hot water from the intermediate outlet 7c. Is adjusted by opening degree control. In the mixing valve 9d, the opening degree is controlled so that hot water from the mixing valve 9b is discharged as it is, so that low temperature water from the water supply branch pipe 25 is not mixed. With this operation, the amount of high-temperature water at 65 ° C. in the hot water storage tank 7 also decreases, so the temperature distribution in the hot water storage tank 7 is as shown in FIG.

  As described above, the first hot water storage operation is performed again when the one-day operation ends and the midnight power charge application time zone is reached.

  The effect of the hot water storage type hot water supply apparatus 1 according to the first embodiment will be described. First, in the hot water storage type hot water supply apparatus 1, medium temperature water heated to a temperature (for example, about 25 ° C.) lower than a user set temperature in the second hot water storage operation, and high temperature water (for example, 65 ° C.) in the hot water storage tank 7 The medium temperature water generated in the hot water storage tank 7 by mixing can be used for mass hot water in hot water filling operation. The operation efficiency of the heat pump unit 10 increases as the temperature after heating of the hot water decreases. In the second hot water storage operation, the temperature after heating is set to a temperature lower than the set temperature of the user, and therefore the temperature after heating can be made extremely low (for example, 25 ° C.) compared to normal boiling, so that the heat pump unit 10 Operation efficiency can be made extremely high. And according to the hot water storage type hot water supply apparatus 1 of the first embodiment, a part of the heat amount used for the hot water filling of the bathtub 50 is generated by the heat amount generated in such a highly efficient second hot water storage operation. I can cover it. For this reason, compared with the case where the amount of heat used for hot water filling is provided only by the amount of heat generated by the first hot water storage operation (that is, high-temperature water in the hot water storage tank 7), the operation efficiency of the entire device is increased and energy saving is achieved. The cost can also be reduced.

  In addition, during the midnight power charge application time period, by performing the first hot water storage operation in which the temperature after heating is higher than the set temperature of the user, high temperature water can be stored in the hot water storage tank 7, so A large amount of heat can be stored in the tank 7. In this way, since a large amount of heat is stored in the hot water storage tank 7 during the midnight power rate application time zone where the power cost is low, the amount of heat generated in the daytime time zone where the power cost is high is suppressed, and the overall power rate is sufficient. Can be reduced. In particular, in the first embodiment, the first hot water storage operation is performed so that the region of the high-temperature water in the hot water storage tank 7 reaches a height lower than the intermediate portion inlet 7b. In addition, a sufficient amount of heat can be stored in the hot water storage tank 7.

  Moreover, in this Embodiment 1, the high temperature water (65 degreeC in FIG. 2) in the area | region below the intermediate part inflow port 7b in the hot water storage tank 7 before the start of a 2nd hot water storage operation, and 2nd The user sets the temperature of the hot water (45 ° C. in FIG. 2) generated by mixing the medium hot water (25 ° C. in FIG. 2) flowing in from the intermediate inlet 7b with the hot water storage operation inside the hot water storage tank 7 The post-heating temperature and operating time of the second hot water storage operation are controlled so as to be equal to or higher than the hot water filling temperature (for example, about 42 ° C.). This makes it possible to increase the efficiency of the second hot water storage operation as much as possible while enabling a large amount of hot water to be discharged at or above the temperature set by the user.

  Moreover, in this Embodiment 1, the 2nd hot water storage operation | movement which produces | generates 45 degreeC medium temperature water in the hot water storage tank 7 is implemented just before the hot water filling operation used as intensive hot water. Therefore, since the time during which the intermediate temperature water in which the temperature zone where Legionella bacteria can propagate is stored in the hot water storage tank 7 can be shortened as much as possible, the reproduction of Legionella bacteria can be reliably suppressed, and more reliable. It can be a high device.

  In the first embodiment, as described above, in the hot water supply operation after the completion of the hot water filling operation, the operation for discharging the hot water remaining in the hot water storage tank 7 with priority from the intermediate outlet 7c of the hot water storage tank 7 is performed. To implement. Thereby, before the start of the first hot water storage operation performed at midnight, the medium temperature water in the hot water storage tank 7 is used up, and only the high temperature water and the low temperature water remain in the hot water storage tank 7 (in FIG. 2 (e)). State) can be realized. When heating water with the heat pump unit 10, the lower the temperature of the water to be heated, the higher the efficiency of operation. For this reason, during the first hot water storage operation, when the warm water remains in the hot water storage tank 7 and the heat pump unit 10 heats the warm water, the operation becomes low efficiency. According to the first embodiment, since such an operation can be avoided, a more efficient operation can be achieved.

  In the first embodiment, an upper inlet through which the hot water heated by the heat pump unit 10 flows into the hot water storage tank 7, and an upper outlet from which the hot water in the hot water storage tank 7 flows out of the hot water storage tank 7 are provided. However, the upper inflow port and the upper outflow port may be separately provided in the hot water storage tank 7. Moreover, in this Embodiment 1, although the intermediate part inflow port 7b and the intermediate part outflow port 7c are provided in the hot water storage tank 7 separately, you may make both common.

DESCRIPTION OF SYMBOLS 1 Hot water storage type hot water supply apparatus, 2 Tank unit, 3 Compressor, 4 Water refrigerant heat exchanger, 5 Expansion valve, 6 Air heat exchanger, 7 Hot water storage tank, 7a Upper outflow inlet, 7b Middle part inflow, 7c Middle part flow Outlet, 7d Lower outlet, 7e Lower inlet, 8 pump, 9a Flow path switching valve, 9b, 9c, 9d Mixing valve, 10 Heat pump unit, 11a, 11b Measurement controller, 12a, 12b Pressure sensor, 13a-13k Temperature Sensor, 14 Solenoid valve, 15 Blower, 16, 17, 18, 19, 20, 22, 23, 24, 26, 27 Piping, 21 Water supply piping, 25 Water supply branch pipe, 30 Remote control device, 50 Bathtub, 60 Hot water supply terminal

Claims (4)

Heating means for heating water;
A hot water storage tank that stratifies and stores water at different temperatures so that the upper side is hot and the lower side is cold;
A first hot water storage path for sending water that has flowed out of the hot water storage tank to the heating means, and allowing hot water heated by the heating means to flow into the hot water storage tank from an upper inflow port provided at an upper portion of the hot water storage tank;
The water discharged from the hot water storage tank is sent to the heating means, and the hot water heated by the heating means flows into the hot water storage tank from an intermediate inlet provided at a position lower than the upper inlet of the hot water storage tank. A second hot water storage path
Hot water flowing out from an upper outlet provided in the upper part of the hot water tank, hot water flowing out from an intermediate outlet provided in a position lower than the upper outlet of the hot water tank, and a lower part of the hot water tank or A hot water discharge path capable of mixing hot water by mixing at least two of the low-temperature water supplied from the outside;
A hot water temperature setting means for allowing a user to set a hot water temperature by the hot water route;
With
When the hot water storage operation is performed in the first hot water storage path, the temperature of the hot water at the outlet side of the heating means is set higher than the set temperature of the hot water temperature setting means, and the hot water storage operation is performed in the second hot water storage path. In this case, a hot water storage type hot water supply apparatus that lowers the temperature of hot water on the outlet side of the heating means below the set temperature. When performing hot water storage operation in the first hot water storage path, the hot water storage area in the hot water storage tank is operated so as to reach a height lower than the intermediate part inlet,
After performing the hot water storage operation in the first hot water storage path, when performing the hot water storage operation in the second hot water storage path, hot water in a region below the intermediate inlet in the hot water storage tank, The operation is performed such that the temperature of the hot water generated by mixing the hot water flowing in from the intermediate portion inlet in the hot water storage tank is equal to or higher than the set temperature. Hot water storage system. An intermediate temperature measuring means for measuring the temperature in the hot water storage tank at a height position equivalent to the intermediate outlet;
When the temperature measured by the intermediate part temperature measuring means is equal to or higher than the set temperature when the hot water is discharged through the hot water path, the hot water flowing out from the intermediate part outlet and the low temperature water are mixed together. The hot water storage hot water supply apparatus according to claim 1 or 2, wherein hot water having the set temperature is generated and discharged.   Hot water storage operation is performed in the first hot water storage path during a day when the power cost is low, and hot water storage operation is performed in the second hot water storage path before a time period during which there is intensive hot water out of the day. The hot water storage type hot water supply apparatus according to any one of claims 1 to 3.

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