JP5454534B2 - Hot water storage hot water supply system - Google Patents

Description

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

  2. Description of the Related Art Hot water storage hot water supply systems that store hot water boiled by heating means in a hot water storage tank and take out the hot water from the hot water storage tank in response to the occurrence of a hot water supply load are widely used. In general, the hot water storage type hot water supply system has features such that the heating capability of the heating means is relatively small compared to the instantaneous hot water supply system and the like, and the rise of the capability at the time of starting the heating means is slow. For this reason, in the hot water storage type hot water supply system, it is necessary to store hot water in a hot water storage tank in advance so that hot water does not run out due to the occurrence of a hot water supply load. On the other hand, from the viewpoint of energy efficiency, it is required to utilize the heat stored in the hot water storage tank as effectively as possible.

  In addition to hot water supply by discharging hot water from hot water taps, hot water storage hot water supply has a function of reheating the bathtub by exchanging heat between hot water taken out from the hot water storage tank and bathtub water circulating from the bathtub. Systems are also known. In such a hot water storage type hot water supply system, it is also necessary to prevent the occurrence of a hot water shortage (hereinafter referred to as “hot water hot water out”) with respect to the heat load required for reheating.

  In Patent Document 1 below, in order to prevent running out of hot water in a hot water storage type hot water system, reheating heat amount calculating means for obtaining a reheating heat amount necessary for retreating the bath water and stored in the hot water storage tank. There is disclosed a technique of providing a remaining hot water calorific value calculating means for obtaining a residual hot water heat amount, and controlling the heating means to perform a boiling operation when the residual hot water calorific value is smaller than the required reheating heat amount.

  Further, in Patent Document 2 below, a calorific value calculation storage means for calculating and storing the amount of heat given to the hot water of the bathtub by the bath chase means, and a boiling temperature based on the calorific value stored in the calorie calculation storage means. A technique for providing a boiling temperature correction means for correction has been proposed.

JP 2004226601 A JP 2009-281658 A

  However, according to the study by the present inventors, the conventional technology can be used for reheating when hot water is supplied after additional boiling in the tank to prevent running out of reheating hot water. There is a risk that a sufficient amount of heat will not remain in the tank.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to provide a hot water storage type hot water supply system capable of improving the proof strength against running-off hot water.

A hot water storage hot water supply system according to the present invention is a heating means for heating water to make hot water, a tank in which hot water heated by the heating means is introduced from the upper side, and water from a water source is introduced from the lower side, A hot water supply circuit for supplying hot water derived from the upper part of the tank to the demand end side, a reheating circuit for exchanging heat from the upper part of the tank with the bath water, and from the upper side to the lower side of the tank When there is a high temperature layer, a medium temperature layer that is higher than the reheating effective temperature that is the temperature of hot water that can be used to raise the bathtub to the bath target temperature, and a low temperature layer , the high temperature layer and the medium temperature layer are mixed. In-tank mixing means for lowering the temperature of the upper part in the tank.

  According to the present invention, when there are a high temperature layer, a medium temperature layer, and a low temperature layer from the upper side to the lower side in the tank, the temperature of the upper part in the tank is lowered by mixing the high temperature layer and the intermediate temperature layer. be able to. Thereby, the temperature of the hot water led out from the tank at the time of hot water supply decreases, and it is possible to increase the amount of heat remaining in the tank after hot water supply and available for reheating. For this reason, it becomes possible to improve the yield strength against running-off hot water.

It is a block diagram which shows the hot water storage type hot-water supply system of Embodiment 1 of this invention. It is a block diagram showing the flow of the signal in the hot water storage type hot-water supply system of Embodiment 1 of this invention. It is a figure for demonstrating the characteristic operation | movement in Embodiment 1 of this invention. It is the table | surface which put together the hot water supply effective heat storage amount before and after hot water supply, and the reheating effective heat storage amount about Embodiment 1 and the comparative example of this invention. It is a block diagram which shows the hot water storage type hot-water supply system of Embodiment 2 of this invention. It is a figure which shows the principal part of the hot water storage type hot-water supply system of Embodiment 2 of this invention. It is a figure which shows the other structural example of the hot water storage type hot-water supply system of Embodiment 2 of this invention. It is a figure which shows the principal part of the hot water storage type hot-water supply system of Embodiment 3 of this invention. It is a figure which shows the principal part of the hot water storage type hot-water supply system of Embodiment 3 of this invention. It is a figure which shows the principal part of the hot water storage type hot-water supply system of Embodiment 4 of this invention.

  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.
≪Device configuration≫
FIG. 1 is a configuration diagram showing a hot water storage type hot water supply system according to Embodiment 1 of the present invention. As shown in FIG. 1, the hot water storage type hot water supply system of this embodiment includes a tank 1, a heating means 2, a heating pump 31, a reheating pump 32, a bathtub pump 33, a mixing pump 34, a mixing valve 4, a reheating valve. Fired heat exchanger 5, bathtub 6, heating pipe 301, water supply pipe 302, outlet pipe 303, mixing pipe 304, hot water supply pipe 305, bathtub return pipe 306a, bathtub return pipe 306b, reheating pipe 307a, A recirculation return pipe 307b, a tank mixing pipe 308, a control means 100, and the like are provided.

  In the following description, the “upper part of the tank 1” is not limited to the uppermost part (top part) of the tank 1, but includes a range of height close to the uppermost part. The “lower part of the tank 1” is not limited to the lowermost part (bottom part) of the tank 1, but includes a range of height close to the lowermost part.

  The heating pipe 301 connects the lower part of the tank 1 and the heating means 2 and also connects the heating means 2 and the upper part of the tank 1. A heating pump 31 is provided in the middle of the heating pipe 301. The heating means 2 boils water into high-temperature hot water, and is configured using, for example, a heat pump cycle. The water supply pipe 302 supplies water from a water source such as city water and is connected to the lower part of the tank 1. In the tank 1, water supplied from the water supply pipe 302 can be stored from the lower side, and hot water boiled by the heating means 2 can be stored from the upper side. The specific gravity of water becomes lighter as the temperature increases. For this reason, the vertical temperature distribution in the tank 1 is high on the upper side and low on the lower side.

  The outlet pipe 303 (hot water supply circuit) connects the upper part of the tank 1 and the mixing valve 4. The mixing valve 4 is further connected to a mixing pipe 304 branched from the water supply pipe 302 and a hot water supply pipe 305. The hot water supplied from the tank 1 through the outlet pipe 303 and the water supplied from the mixing pipe 304 are mixed by the mixing valve 4 to generate hot water whose temperature is adjusted, and this temperature is adjusted. Hot water is supplied through a hot water supply pipe 305 to a demand end such as a bath tub 6, a faucet, and a shower.

  The reheating heat exchanger 5 heats the bathtub water by exchanging heat between the hot water supplied from the tank 1 and the bathtub water circulating from the bathtub 6. The reheating pipe 307 a connects the upper portion of the tank 1 and the reheating heat exchanger 5. The reheating return pipe 307 b is connected to a predetermined height of the tank 1 from the reheating heat exchanger 5 via the reheating pump 32. In the present embodiment, a reheating circuit is configured by the reheating heat exchanger 5, retreating piping 307 a, recirculation returning piping 307 b, and reheating pump 32.

  The bathtub outlet pipe 306 a connects the reheating heat exchanger 5 and the bathtub 6. The bathtub return pipe 306 b is connected to the reheating heat exchanger 5 from the bathtub 6 via the bathtub pump 33. Bathtub water is recirculated from the bathtub 6 to the heat exchanger 5 by the bathtub side circuit including the bathtub return pipe 306a and the bathtub return pipe 306b.

  One end of the tank mixing pipe 308 (mixing circuit) is connected to the upper part of the tank 1, and the other end is connected to a part between the upper part and the lower part of the tank 1 (preferably a part above the middle height). ing. A mixing pump 34 is provided in the middle of the tank mixing pipe 308. In this embodiment, the tank mixing pipe 308 and the mixing pump 34 constitute an in-tank mixing means.

  The control unit 100 controls operations of the heating unit 2, the heating pump 31, the reheating pump 32, the bathtub pump 33, the mixing pump 34, and the mixing valve 4. In addition, a user interface device (not shown) such as a remote controller installed in a bathroom or kitchen is connected to the control means 100 so as to be communicable by wire or wirelessly.

  The tank 1 is provided with six hot water storage temperature sensors 501a to 501f (temperature distribution detecting means) at intervals in the height direction (vertical direction). According to these hot water storage temperature sensors 501a to 501f, the hot water storage temperature in the tank 1 can be detected together with the distribution in the vertical direction. Note that the number of hot water storage temperature sensors is not limited to this, and may be any number that can detect the temperature distribution in the vertical direction in the tank 1.

  The heating pipe 301 is provided with a boiling temperature sensor 502 that detects the hot water temperature after heating on the downstream side of the heating means 2. The water supply pipe 302 is provided with a water supply temperature sensor 504 for detecting the water supply temperature. A derived temperature sensor 503 for detecting the temperature of hot water derived from the tank 1 is provided at the top of the tank 1. The hot water supply pipe 305 is provided with a hot water supply temperature sensor 505 that detects the temperature of hot water that flows out of the mixing valve 4 and is supplied to the demand end. The bathtub return pipe 306b is provided with a bathtub return temperature sensor 506 that detects the temperature of the bathtub water flowing from the bathtub 6 into the reheating heat exchanger 5. In addition, you may utilize this bathtub return temperature sensor 506 as a means to detect the temperature of the bathtub 6 by operating the pump 33 for bathtubs regularly. The hot water supply pipe 305 is provided with a hot water supply flow rate sensor 601 for detecting the amount of hot water supplied to the demand end. A recuperation hot water temperature sensor 507 (a recuperation hot water temperature) that detects the temperature of hot water that returns from the reheating heat exchanger 5 to the tank 1 (hereinafter referred to as “recovery hot water”) is provided in the recirculation return pipe 307b. Acquisition means) is provided. As the reheating hot water temperature acquisition means, instead of directly detecting the reheating hot water temperature by the reheating hot water temperature sensor 507, the rotation speed of the reheating pump 32 and the rotation speed of the bathtub pump 33 are detected. Further, the value of the reheating hot water temperature may be acquired by estimation from the detection temperature of the derived temperature sensor 503 and the bath return temperature sensor 506 or the like.

  FIG. 2 is a block diagram showing a signal flow in the hot water storage type hot water supply system according to Embodiment 1 of the present invention. As shown in FIG. 2, the control means 100 includes a heat storage amount calculation means 101, a necessary heat amount prediction means 104, a heating control means 105, a target temperature setting means 107, a pump control means 108, and the like.

  The control means 100 includes a timer that is time detection means, hot water storage temperature sensors 501a to 501f, a boiling temperature sensor 502, a derived temperature sensor 503, a feed water temperature sensor 504, a hot water supply temperature sensor 505, a bathtub return temperature sensor 506, and a rebirth return. Information from the hot water temperature sensor 507 and the hot water supply flow rate sensor 601 is input. The control means 100 controls the heating means 2, the heating pump 31, the reheating pump 32, the bathtub pump 33, the mixing pump 34, and the mixing valve 4 based on the input information.

  The target temperature setting means 107 is a target temperature (hereinafter referred to as “the temperature is maintained” including the heat retention) in the reheating operation based on a user instruction or the like input to the user interface device. This is referred to as “bath target temperature”.

  The heat storage amount calculation means 101 includes a heat storage amount that can be used for hot water supply to the demand end (hereinafter referred to as “hot water effective heat storage amount”) and a heat storage amount that can be used for reheating (hereinafter referred to as “reheating effective heat storage amount”). Is calculated). The hot water supply effective heat storage amount is calculated based on the information on the temperature distribution in the tank detected by the hot water storage temperature sensors 501a to 501f and the water supply temperature information of the water supply temperature sensor 504. Generally, the hot water supply effective heat storage amount is calculated by integrating the temperature distribution in the tank with the water supply temperature as the energy reference temperature. Here, the hot water supply effective heat storage amount may be calculated without integrating a region below a general predetermined hot water supply temperature (for example, 40 ° C.).

  The reheating effective heat storage amount is calculated based on the tank temperature distribution information by the hot water storage temperature sensors 501a to 501f and the bathtub target temperature set by the target temperature setting means 107. In general, the temperature of hot water that can be used to raise the bathtub 6 to the bath target temperature (for example, the bath target temperature + 5 ° C.) is set as the reheating effective temperature, and the reheating effective temperature is set as the energy reference temperature in the tank. The reheating effective heat storage amount is calculated by integrating the temperature distribution. The reheating effective temperature may be set based on the bathtub target temperature set by the target temperature setting means 107, or may be set based on a general predetermined bathtub target temperature (for example, 40 ° C.).

  The necessary heat amount predicting means 104 is a heat amount necessary for hot water supply after the present time (hereinafter referred to as “hot water supply necessary heat amount”) and a heat amount necessary for reheating after the present time (hereinafter referred to as “required heat amount for reheating”). Predict. The amount of heat required for hot water supply is predicted based on information such as past use history of hot water supply by users and a predetermined design standard that guarantees the minimum reduction. The amount of heat required for reheating is predicted based on information such as past use results of reheating by users, the current temperature and amount of hot water in the bathtub 6, and a predetermined design standard that guarantees the minimum reduction.

  The heating control means 105 determines whether or not it is necessary to perform boiling based on the calculated hot water supply effective heat storage amount, reheating effective heat storage amount, hot water supply necessary heat amount, and reheating required heat amount, and performs boiling. When necessary, the heating means 2 and the heating pump 31 are activated to perform a boiling operation.

  The pump control means 108 controls the number of rotations of the heating pump 31, the reheating pump 32, the bathtub pump 33, and the mixing pump 34, and adjusts the circulation amount (flow rate) of each pump.

  The configuration of the hot water storage type hot water supply system in the first embodiment has been described above. Next, the operation of the hot water storage type hot water supply system in the first embodiment will be described. In the following description, the operation may be described with specific numerical values. However, the numerical values in this case are merely examples, and the present invention is not limited to the numerical values.

≪Basic operation≫
First, the basic operation of the hot water storage type hot water supply system according to the first embodiment will be described. Low-temperature water flows into the tank 1 from below through the water supply pipe 302 and is stored. When performing the boiling operation, the heating means 2 and the heating pump 31 are driven, and the water in the tank 1 is drawn into the heating pipe 301 from the lower part and led to the heating means 2. The heating means 2 heats the introduced water and boils it into hot water. The boiled hot water flows into the tank 1 from above through the heating pipe 301 and is stored.

  There are the following two cases in which such boiling operation is performed. One is a case where boiling is performed for the purpose of accumulating most of the estimated daily required hot water supply amount and reheating required heat amount in the tank 1 during a low electricity bill time period (night time zone). . The other is a case in which when the amount of heat stored in the tank 1 is reduced, additional boiling is performed for the purpose of preventing the hot water supply and the amount of heat necessary for reheating and replenishment.

  When hot water is supplied to the demand end, the hot water stored in the tank 1 flows out from the upper part to the outlet pipe 303 and is led to the mixing valve 4. At this time, the same amount of water as the extracted hot water flows into the lower portion of the tank 1 from the water supply pipe 302. The mixing valve 4 mixes the hot water supplied from the tank 1 and the water supplied from the mixing pipe 304 and supplies the mixed water to the demand end such as a faucet, shower, and bathtub 6 through the hot water supply pipe 305.

  Next, the chasing operation of the bathtub 6 will be described. When the reheating operation is performed, the reheating pump 32 and the bathtub pump 33 are driven. As a result, the hot water stored in the tank 1 flows out from the upper part to the follow-up piping 307 a and is led to the follow-up heat exchanger 5. Almost simultaneously with this timing, the bathtub water in the bathtub 6 is guided to the reheating heat exchanger 5 through the bathtub return pipe 306b. The hot water of the tank system whose temperature has been lowered by applying heat to the bathtub water in the reheating heat exchanger 5 (reheating hot water) returns to the tank 1 through the recirculation return pipe 307b. The bathtub water whose temperature has been increased by receiving heat in the reheating heat exchanger 5 returns to the bathtub 6 through the bathtub outlet pipe 306a. Such a chasing operation is forcibly started in accordance with a user instruction input to the user interface device, or the bath temperature periodically detected by the bath return temperature sensor 506 is the target temperature setting means 107. When the temperature becomes lower than the target bath temperature set by a predetermined amount or more, it is automatically started. Thereafter, the chasing operation is forcibly terminated by a user instruction input to the user interface device, or the bath temperature detected by the bath return temperature sensor 506 is higher than the bath target temperature by a predetermined amount or more. When it becomes, the chasing operation ends automatically.

≪Characteristic action≫
FIG. 3 is a diagram for explaining a characteristic operation in the present embodiment. Hereinafter, with reference to FIG. 3, a characteristic operation in the present embodiment will be described.

  Here, as shown in the upper left column of FIG. 3, after the amount of heat stored in the tank 1 having a capacity of 370 L decreases and the remaining hot water amount reaches 50 ° C./50 L, additional boiling is performed to secure the necessary heat amount. Assuming that The feed water temperature is 10 ° C., and the amount of hot water that is additionally boiled is 70 ° C. · 50 L. In the tank 1 after the additional boiling, from the upper part to the lower part, a high temperature layer of 70 ° C./50 L formed by the additional boiling and a hot water remaining before the additional boiling 50 ° C. / There is a 50 L medium temperature layer and a 10 ° C., 270 L low temperature layer that has not been boiled.

  After this additional boiling, in this embodiment, as shown in the lower left column of FIG. 3, the mixing pump 34 is driven and hot water is circulated through the tank mixing pipe 308, whereby a medium temperature layer of 50 ° C. and 50 L is obtained. And a high temperature layer of 70 ° C. and 50 L are mixed. Thereby, both mix and 60 degreeC * 100L hot water is produced | generated, and the temperature of the upper part in the tank 1 falls from 70 degreeC to 60 degreeC. In the present embodiment, the tank mixing pipe 308 has a circulation direction in which hot water flows from the top to the bottom, but the reverse circulation direction may be used.

  Thereafter, a hot water supply demand occurs at the demand end, and 40 ° C./100 L hot water is supplied to the demand end. In this case, the mixing valve 4 mixes 60 ° C./60 L hot water supplied from the tank 1 and 10 ° C./40 L low temperature water supplied from the mixing pipe 304 to give 40 ° C./100 L hot water. Generate and supply hot water to the demand end. For this reason, the amount of remaining hot water in the tank 1 after hot water supply is 60 degreeC * 40L, as shown in the lower right column of FIG. At this time, the reheating effective heat storage amount remaining in the tank 1 is (60 ° C.−45 ° C.) × 40 L = 600 kcal, assuming that the reheating effective temperature is 45 ° C.

  On the other hand, the case where 40 degreeC * 100L hot water is supplied to a demand end, without mixing an intermediate temperature layer and a high temperature layer after additional boiling is demonstrated as a comparative example. In this case, since 70 ° C. hot water is supplied from the tank 1 to the mixing valve 4, the mixing valve 4 supplies 70 ° C./50 L hot water supplied from the tank 1 and 10 supplied from the mixing pipe 304. Mixing with low-temperature water of ℃ ・ 50L to produce hot water of 40 ℃ ・ 100L and supplying hot water to the demand end. For this reason, the amount of remaining hot water in the tank 1 after hot water supply is 50 degreeC * 50L, as shown in the upper right column of FIG. At this time, the reheating effective heat storage amount remaining in the tank 1 is (50 ° C.−45 ° C.) × 50 L = 250 kcal, assuming that the reheating effective temperature is 45 ° C.

  As described above, according to the present embodiment, it is possible to increase the effective amount of reheating remaining after hot water supply from 250 kcal to 600 kcal as compared with the comparative example. This is because the temperature of the upper part in the tank 1 is reduced from 70 ° C. to 60 ° C. by mixing the intermediate temperature layer and the high temperature layer, so that the temperature of the hot water led out from the tank 1 during hot water supply decreases, This is because exergy loss due to hot water supply is reduced. In this way, in this embodiment, when hot water supply demand occurs after additional boiling, it is possible to increase the amount of additional effective heat that remains in the tank after hot water supply. For this reason, the resistance to reheating hot water is improved, and reheating hot water can be suppressed.

  FIG. 4 is a table summarizing the hot water supply effective heat storage amount and the reheating effective heat storage amount before and after hot water supply for the above-described embodiment and comparative example. As shown in FIG. 4, the hot water supply effective heat storage amount is the same between this embodiment and the comparative example before and after hot water supply. That is, the hot water supply effective heat storage amount does not decrease by mixing the middle temperature layer and the high temperature layer. As described above, in the present embodiment, it is possible to increase the amount of reheating effective heat storage remaining after hot water supply without increasing the amount of additional boiling water, as compared with the comparative example. For this reason, it is possible to improve the proof strength against running out of hot water while suppressing energy consumption.

  In the present embodiment, the hot water in the tank 1 is circulated through the tank mixing pipe 308 that connects the upper portion of the tank 1 and the portion between the upper portion and the lower portion of the tank 1. The layer and the intermediate temperature layer can be reliably mixed, and the temperature of the upper part in the tank 1 can be quickly reduced.

  In the present embodiment, the high temperature layer refers to hot water formed by additional boiling by the heating unit 2 or a predetermined temperature range (a temperature range corresponding to the boiling temperature of the heating unit 2, for example, 65 ° C. to 90 ° C. ). The medium temperature layer is the hot water remaining in the tank 1 before the additional boiling by the heating means 2 or the hot water having a temperature range lower than the lower limit value of the high temperature layer and equal to or higher than a predetermined temperature (for example, 45 ° C. or reheating effective temperature). It is. The low temperature layer is water that has not been boiled or water in a temperature range lower than the lower limit value of the intermediate temperature layer.

Embodiment 2. FIG.
Next, the second embodiment of the present invention will be described with reference to FIG. 5 to FIG. The description is omitted.

  FIG. 5 is a configuration diagram illustrating a hot water storage type hot water supply system according to Embodiment 2 of the present invention. As will be described below, in the second embodiment, the mixing circuit that mixes the inside of the tank 1 and the reheating circuit are shared in whole or in part, so that the cost-saving and simple configuration can be realized. The same effect as in the first mode can be obtained.

  As shown in FIG. 5, the reheating return pipe 307b connects the reheating heat exchanger 5 and a portion between the upper portion and the lower portion of the tank 1 (preferably a portion above an intermediate height). . FIG. 6 is a diagram illustrating a main part of the hot water storage type hot water supply system according to the second embodiment of the present invention. As shown in FIG. 6, when mixing the high temperature layer and the medium temperature layer in the tank 1, the reheating pump 32 is driven, and the hot water in the upper portion of the tank 1 is recirculated to the recirculation piping 307a. It is circulated through the heat exchanger 5 and the return return pipe 307b and returned to the portion between the upper part and the lower part of the tank 1. Thereby, the high temperature layer and the intermediate temperature layer in the tank 1 are mixed, and the temperature of the upper part in the tank 1 is lowered, and the same effect as in the first embodiment is obtained. Further, in the present embodiment, the tank mixing pipe 308 and the mixing pump 34 in the first embodiment are not required, so that the cost can be reduced.

  Further, in the present embodiment, as shown in FIG. 6, the flow direction of the hot water flowing into the tank 1 from the reflow return pipe 307b is regulated at the return port where the reflow return pipe 307b is connected to the tank 1. A flow path regulating member 11 is provided. By this flow path regulating member 11, the flow direction of the hot water flowing into the tank 1 from the recirculation return pipe 307 b is regulated in an upward direction or an obliquely upward direction. In this embodiment, when the high temperature layer and the middle temperature layer in the tank 1 are mixed with each other, the region to be mixed can be surely limited to the region above the return port. It is possible to reliably suppress mixing up to a region below the region. Further, in the reheating operation, the reheating hot water is allowed to flow upward in the tank 1 to promote the mixing of the reheating hot water and the high-temperature water in the upper portion of the tank 1, and the reheating return port. Mixing with a lower region can be suppressed. Note that also in the return port where the tank mixing pipe 308 of Embodiment 1 is connected to the tank 1, the flow direction of the hot water flowing into the tank 1 from the tank mixing pipe 308 is upward or diagonally similar to the above. You may comprise so that it may become an upper direction.

  FIG. 7 is a diagram illustrating another configuration example of the hot water storage type hot water supply system according to Embodiment 2 of the present invention. In the present embodiment, as shown in FIG. 7, a bypass flow path 307 c that bypasses the reheating heat exchanger 5, and a flow path that can be switched between the reheating heat exchanger 5 side and the bypass flow path 307 c side. When the switching valve 307d is provided and the high temperature layer and the middle temperature layer in the tank 1 are mixed, the flow path switching valve 307d may be switched to the bypass flow path 307c side. Thereby, when mixing the high temperature layer and the intermediate temperature layer in the tank 1, the circulating hot water does not pass the reheating heat exchanger 5 but passes the bypass flow path 307 c. Heat dissipation loss can be avoided. For this reason, it is possible to further increase the reheating effective heat storage amount remaining after the hot water supply.

  In the configuration example shown in FIG. 7, a mixing circuit is configured by a part of the follow-up return pipe 307 a and the return return pipe 307 b and the bypass flow path 307 c. Also in this case, since the mixing circuit and the reheating circuit share a common flow path, circuit parts such as pipes and pumps can be reduced, and cost can be reduced.

Embodiment 3 FIG.
Next, the third embodiment of the present invention will be described with reference to FIG. 8 and FIG. 9. The difference from the above-described first or second embodiment will be mainly described, and the same or corresponding parts will be the same. Reference numerals are assigned and description is omitted.

  8 and 9 are diagrams showing a main part of the hot water storage type hot water supply system according to Embodiment 3 of the present invention. As shown in FIG. 8, in the hot water storage type hot water supply system of the present embodiment, a tank mixing pipe 309 for returning hot water derived from the upper part in the tank 1 to the upper part in the tank 1, and hot water in the tank mixing pipe 309. The in-tank mixing means is constituted by the mixing pump 34 for circulating the gas. That is, the outlet for taking out hot water into the tank mixing pipe 309 and the return port for returning the hot water from the tank mixing pipe 309 into the tank 1 are both provided in the upper part of the tank 1.

  When mixing the high temperature layer and the medium temperature layer in the tank 1, the mixing pump 34 is driven. As a result, the region on the upper side in the tank 1 is mixed within the range affected by the jet flow flowing back from the tank mixing pipe 309 into the tank 1 and flowing downward. Therefore, the range of the mixed region can be adjusted by controlling the circulation amount of the mixing pump 34 by the rotational speed.

  When mixing the high temperature layer and the medium temperature layer in the tank 1, mixing to a region of low temperature water below a predetermined effective heating temperature (for example, 45 ° C.) may reduce the effective heating amount remaining after hot water supply. . Therefore, when mixing the high temperature layer and the medium temperature layer in the tank 1, it is desirable to detect the temperature distribution in the vertical direction in the tank 1 and mix the medium temperature layer and the high temperature layer above the effective reheating temperature. . Thereby, it is possible to increase the reheating effective heat amount remaining after hot water supply more reliably.

  In the present embodiment, when mixing the high temperature layer and the medium temperature layer in the tank 1, the temperature distribution in the vertical direction in the tank 1 is detected, and the mixing pump 34 is mixed so that the region above the effective reheating temperature is mixed. By controlling the circulation amount of the mixture, the range of the mixed region can be adjusted. For example, as shown in FIG. 8, when the range of the middle temperature layer and the high temperature layer above the reheating effective temperature is small (the upper stage in FIG. 8), the mixing area of the mixing region can be reduced by reducing the circulation amount of the mixing pump 34. When the range is reduced and the range between the medium temperature layer and the high temperature layer above the effective reheating temperature is large (the lower stage in FIG. 8), the range of the mixing region is increased by increasing the circulation amount of the mixing pump 34. can do. In this way, according to the vertical temperature distribution in the tank 1, the medium temperature layer and the high temperature layer are mixed in an appropriate region (region above the effective reheating temperature), thereby remaining after the hot water supply. The effective heat storage amount can be further increased.

  In the present embodiment, as shown in FIG. 9, the flow of hot water that has flowed into the tank 1 from the tank mixing pipe 309 is provided at the return port for returning the hot water from the tank mixing pipe 309 to the upper part of the tank 1. A flow path regulating member 12 that regulates the direction is provided. By this flow path regulating member 12, the flow direction of the hot water flowing into the tank 1 from the tank mixing pipe 309 is restricted in a direction away from the outlet to the tank mixing pipe 309. In this embodiment, such a configuration ensures that hot water returned from the tank mixing pipe 309 to the tank 1 flows to the outlet side when the high temperature layer and the intermediate temperature layer in the tank 1 are mixed. Since it can suppress, it can prevent that mixing becomes inadequate by a short cycle, and can mix more reliably.

Embodiment 4 FIG.
Next, a fourth embodiment of the present invention will be described with reference to FIG. 10. The description will focus on the differences from the first to third embodiments described above, and the same or corresponding parts will be denoted by the same reference numerals. The description is omitted.

  FIG. 10 is a diagram illustrating a main part of the hot water storage type hot water supply system according to the fourth embodiment of the present invention. As shown in FIG. 10, in the hot water storage type hot water supply system of the present embodiment, a screw propeller (rotor, stirrer) 35 disposed above the tank 1, and a motor 36 that rotationally drives the screw propeller 35. Is provided. In the present embodiment, the screw propeller 35 and the motor 36 as the stirring means constitute an in-tank mixing means.

  When mixing the high temperature layer and the medium temperature layer in the tank 1, the motor 36 is driven to rotate the screw propeller 35. Thereby, the area | region of the upper side in the tank 1 is mixed in the range which the downward water flow formed with the screw propeller 35 influences. Therefore, the range of the mixed region can be adjusted by controlling the rotational speed of the screw propeller 35. As a result, the same effect as in the third embodiment can be obtained. The configuration of the stirring means is not limited to the screw propeller 35 and the motor 36, and any configuration may be used as long as the upper region in the tank 1 can be stirred.

DESCRIPTION OF SYMBOLS 1 Tank 2 Heating means 4 Mixing valve 5 Reheating heat exchanger 6 Bath 11,11 Flow path control member 31 Heating pump 32 Reheating pump 33 Bath pump 34 Mixing pump 35 Screw propeller 36 Motor 100 Control means 301 Heating Piping 302 water supply piping 303 outlet piping 304 mixing piping 305 hot water supply piping 306a bathtub return piping 306b bathtub return piping 307a additional return piping 307b additional return piping 307c bypass channel 307d channel switching valves 308, 309 tank mixing Piping 501a to 501f Hot water storage temperature sensor 502 Boiling temperature sensor 503 Derived temperature sensor 504 Feed water temperature sensor 505 Hot water supply temperature sensor 506 Bath return temperature sensor 507 Reheating hot water temperature sensor 601 Hot water flow rate sensor

Claims (11)

Heating means for heating the water to hot water;
A tank into which hot water heated by the heating means is introduced from the upper side, and water from a water source is introduced from the lower side;
A hot water supply circuit for supplying hot water derived from the upper part of the tank to the demand end side,
A reheating circuit for exchanging heat from the hot water derived from the upper part of the tank with bathtub water;
From the upper side to the lower side in the tank, there are a high temperature layer, a medium temperature layer above the reheating effective temperature that is the temperature of hot water that can be used to raise the bathtub to the bath target temperature, and a low temperature layer. In the case, in-tank mixing means for lowering the temperature of the upper part in the tank by mixing the high temperature layer and the intermediate temperature layer,
A hot water storage hot water system. When the additional boiling by the heating means is performed after the amount of heat stored in the tank is reduced, the mixing means in the tank includes the high-temperature layer formed by the additional boiling after the additional boiling. The hot water storage hot water supply system according to claim 1, wherein the intermediate temperature layer composed of hot water remaining in the tank before the additional boiling is mixed.   The hot water storage hot water supply system according to claim 1 or 2, wherein the in-tank mixing means is capable of adjusting a range of a region in which mixing in the tank is performed. A temperature distribution detecting means for detecting a vertical temperature distribution in the tank;
The hot water storage hot water supply system according to claim 3, wherein the in-tank mixing unit adjusts a range of a region in the tank where mixing is performed based on the detected temperature distribution. The in-tank mixing means includes
A mixing circuit in which one end communicates with the upper part in the tank and the other end communicates with a portion between the upper part and the lower part in the tank;
A mixing pump for circulating hot water in the mixing circuit;
The hot water storage type hot-water supply system according to claim 1.   The hot water storage hot water supply system according to claim 5, wherein the reheating circuit and the mixing circuit are at least partially shared by a flow path. The mixing circuit includes a bypass flow path that bypasses the reheating heat exchanger of the reheating circuit, and a flow path switching valve that switches between the reheating heat exchanger and the bypass flow path,
The hot water storage hot water supply system according to claim 6, wherein when the high temperature layer and the intermediate temperature layer in the tank are mixed, the flow path switching valve is switched to the bypass flow path side.   The return port for introducing the hot water of the mixing circuit into the portion between the tanks is configured such that the flow direction of the hot water flowing into the tank is upward or obliquely upward. The hot water storage hot water supply system according to any one of the above. The in-tank mixing means includes
A mixing circuit for returning hot water led out from the upper part of the tank to the upper part of the tank;
A mixing pump for circulating hot water in the mixing circuit;
Including
The hot water storage hot water supply system according to claim 1, wherein a range of a region where mixing is performed in the tank can be adjusted by a circulation amount of the mixing pump. The in-tank mixing means includes
A mixing circuit for returning hot water led out from an outlet provided in the upper part of the tank to a return port provided in the upper part of the tank;
A mixing pump for circulating hot water in the mixing circuit;
Including
The hot water storage hot water supply system according to claim 1, wherein the return port is configured such that a flow direction of hot water flowing into the tank is away from the take-out port.   The hot water storage hot water supply system according to claim 1, wherein the mixing means in the tank includes a stirring means for stirring the hot water in the tank.

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