JP5347654B2 - Hot water storage hot water supply system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a hot water storage type hot water supply system capable of making the most of an amount of heat of hot water stored in a hot water storage tank accumulated by heat recovery from an external heat source, and consequently, suppressing a fuel consumption amount of an auxiliary heat source machine to the minimum. <P>SOLUTION: Even when the temperature of the hot water stored in the hot water storage tank 3 is lower than a set hot water temperature, the stored hot water taken out from an auxiliary heating passage 51 is heated by the auxiliary heat source machine 6. Meanwhile, the stored water taken out from a stored hot water direct supply passage 52 is merged at a junction 50 and mixed. Both flow rates are adjusted by a first flow rate adjusting valve 56 and a second flow rate adjusting valve 57, thereby adjusting the temperature to the set hot water supply temperature. The hot water can be supplied to a hot water tap 7 without mixing supplied water by a mixing valve 55. When the used flow rate of the hot water is low and a combustion operation is difficult, the water supplied from a branch water supply passage 45 can be mixed by a first mixing valve 53 in order to continue the combustion. <P>COPYRIGHT: (C)2011,JPO&amp;INPIT

Description

  The present invention stores hot water by storing heat from an external heat source such as cooling water exhaust heat from a gas engine or a fuel cell, heat from a heat pump refrigerant, or natural energy solar heat, and the stored hot water is used as hot water. The present invention relates to a hot water storage type hot water supply system that is used, and particularly relates to a technique that can make maximum use of stored hot water storage.

  2. Description of the Related Art Conventionally, as a hot water storage type hot water supply system, a system that stores hot water heated by heat recovery from cooling water exhaust heat of a gas engine in a hot water storage tank is known (see, for example, Patent Document 1 or Patent Document 2). In Patent Document 1, if the hot water storage temperature is higher than the set hot water supply temperature, hot water is taken out from the top of the hot water storage tank by mixing the hot water and the hot water, and then the hot water is supplied. If it is lower, hot water is supplied after the hot water heated by the combustion operation of the auxiliary heat source machine and the hot water are mixed to obtain a set hot water temperature.

  Further, in Patent Document 2, hot water is stored in a hot water tank by heat exchange with a refrigerant of a heat pump, and hot water is stored at a set hot water temperature by mixing hot water stored in the hot water tank and water supply. It is disclosed that when it is determined that the water is generated, the hot water is heated by the combustion operation of the auxiliary heat source device provided in parallel with the hot water storage tank, and the hot water is used for the hot water supply.

JP 2004-125300 A JP-A-2005-214552

  By the way, in the hot water storage type hot water supply system, since the heat storage by the hot water storage depends on the state of the external heat source, the degree of the heat storage varies due to the variation in the heat recovery from the external heat source. It has been added. However, in the conventional hot water storage type hot water supply system, the hot water that has been stored at an angle cannot be used to the maximum extent in the hot water supply, and the fuel consumption has increased due to the increase in the combustion operation by the auxiliary heat source machine. I have it.

  For example, in a hot water storage hot water system in which solar heat, which is an external heat source, is collected by a solar collector, and this collected heat is stored as hot water in a hot water storage tank. It will be affected by variations in heat recovery from solar heat accompanying changes. In this case, in the summertime when there is a lot of hot sun, the hot water of the solar collector can be actively taken into the hot water storage tank, so the hot water often becomes higher than the set hot water temperature, and when using hot water, Without using an auxiliary heat source machine, hot water can be supplied after mixing hot water with hot water and adjusting the temperature to the set hot water temperature. However, in winter when the outside air temperature is low and the sunlight is weak, sufficient heat cannot be collected from the sunlight, and the hot water stored in the hot water tank often does not exceed the set hot water supply temperature. In many cases, the hot water storage in the warm water state is used for hot water supply after auxiliary heating by the combustion operation by the machine.

  At the time of auxiliary heating by this auxiliary heat source machine, it is usually necessary to heat to a temperature of 60 ° C. or higher in order to prevent the formation of condensation due to the combustion operation of the instantaneous water heater that is the auxiliary heat source machine. Even if the hot water storage temperature is in the warm water state, in order to perform the combustion operation, it is necessary to heat the water once to 60 ° C. or higher, and then mix the feed water and lower it to the set hot water temperature. As a result, it is difficult to say that the amount of heat stored as hot water in the hot water storage tank is maximized by heat recovery.

  Furthermore, in the case of using a latent heat recovery type high efficiency water heater, which has been widespread in recent years, as an auxiliary heat source device, the high efficiency water heater has a characteristic that the higher the incoming water temperature, the lower the thermal efficiency. Therefore, in a hot water storage hot water supply system using solar heat with a high ratio of auxiliary heating for hot water storage in warm water (medium hot water) state, there is a risk that the merit of applying a high efficiency hot water supply device may be lost.

  The present invention has been made in view of such circumstances, and its purpose is to make maximum use of the amount of hot water stored in a hot water tank that has been stored by heat recovery from an external heat source, As a result, the present invention is to provide a hot water storage type hot water supply system capable of minimizing fuel consumption (heating energy consumption) due to auxiliary heating of an auxiliary heat source machine.

In order to achieve the above object, in the present invention, a hot water storage tank that stores heat as hot water storage by recovering heat from an external heat source, an auxiliary heat source machine, and auxiliary heating water that is auxiliary heated by the auxiliary heat source machine and discharged, or the hot water storage tank. The hot water storage hot water supply system provided with the first mixing means for supplying hot water after mixing the hot water taken from the outside with the hot water taken out from the inside is provided with the following specific items. That is, an auxiliary heating path for supplying hot water taken out from the top of the hot water storage tank to the auxiliary heat source unit for auxiliary heating, and a hot water outlet path from the auxiliary heat source unit are provided in the first mixing means. A first flow rate adjusting means for adjusting the flow rate of the auxiliary hot water to be supplied, and a hot water storage taken out from the top of the hot water storage tank at a position downstream of the first flow rate adjusting means and the first mixing means. A hot water storage direct hot water supply passage that joins the hot water supply passage at an upstream position of the hot water supply, and a second flow rate adjusting means that is interposed in the hot water storage direct hot water supply passage and adjusts the flow rate of the hot water storage that joins the hot water supply passage. I made it .

In the case of this specific matter, when using hot water stored in the hot water tank for hot water supply, it is possible to supply the hot water in the following manner, and this makes it possible to maximize the amount of heat stored in the hot water tank. As a result, the amount of fuel consumed by the auxiliary heating of the auxiliary heat source machine can be minimized. That is, while the auxiliary heat source machine performs auxiliary heating for hot water storage in the hot water storage tank taken out from the auxiliary heating path, the hot water storage in the hot water storage tank taken out from the hot water storage direct hot water path is joined to this auxiliary heated auxiliary heating water. The temperature is adjusted to the set hot water temperature by adjusting the flow rate of the auxiliary hot water by the first flow rate adjusting means and the flow rate of the hot water from the hot water storage direct hot water supply path by the second flow rate adjusting means. To. That is, as temperature adjustment to the set hot water temperature for finally supplying hot water, mixing with the hot water in the first mixing means is omitted, and the hot water in the hot water tank is mixed. is there. This makes it possible to supply hot water using 100% of the hot water in the hot water tank even if the hot water temperature in the hot water tank is lower than the set hot water temperature, while using auxiliary heating with an auxiliary heat source machine. Nevertheless, since the temperature is not adjusted by mixing the feed water, the amount of combustion in the auxiliary heat source machine can be reduced compared to the case where the temperature is adjusted by mixing the feed water. It is possible to reduce usage consumption.

Further, in the present invention, in the hot water storage type hot water supply system according to the above-mentioned specific item, a hot water supply control means is provided, and as the hot water control means, a control set for hot water supply operation in a combination of the temperature of the hot water stored in the hot water tank and the set hot water supply temperature The hot water storage direct hot water supply mode that is executed when the hot water storage temperature is high and the hot water storage temperature is medium temperature based on the hot water storage temperature classification divided into high temperature, medium temperature, and low temperature in comparison with the set hot water temperature. The hot water supply preheating hot water supply mode to be performed and the hot water storage mixed hot water supply mode executed when the hot water storage temperature is low can be provided. In this case, the hot water storage direct hot water supply mode is configured such that the hot water taken out from the hot water storage tank through the hot water storage direct hot water supply passage is mixed with the hot water in the first mixing means and the temperature is adjusted to the set hot water supply temperature. As the water supply preheating hot water supply mode, the hot water storage taken out from the hot water storage tank through the auxiliary heating path is auxiliary heated by the auxiliary heat source unit, and the auxiliary heating water is mixed with the hot water in the first mixing means to set the hot water supply temperature. In the hot water storage mixed hot water supply mode, the hot water taken out from the hot water storage tank through the auxiliary heating path is auxiliary heated by the auxiliary heat source device, and the auxiliary heated hot water is stored in the hot water storage tank from the hot water storage tank. The stored hot water taken out directly through the hot water supply passage is merged, and at the time of merging, the flow rate of both the first flow rate adjusting means and the second flow rate adjusting means is adjusted. And configured to hot water in terms of the temperature control so that the set hot water supply temperature by (claim 1). In this case, the hot water supply control capable of specifically realizing the above-described operation according to the present invention is realized by executing the hot water storage mixed hot water supply mode.

Also, the auxiliary heating path is provided with a second mixing means, and the auxiliary heat source unit is mixed with hot water taken out from the top of the hot water storage tank and external water supply as the second mixing means. On the other hand, it can also be set as the structure which can be supplied for auxiliary heating. In this case, in the water supply preheating hot water supply mode or the hot water storage mixed hot water supply mode, not only hot water taken out from the hot water storage tank but also water supplied by the second mixing means as an object to be supplied to the auxiliary heat source machine for auxiliary heating. It is also possible to select a mixture of the above (Claim 2 ). By making this selection possible, the auxiliary heat source machine can operate properly when the temperature difference between the set hot water temperature and the hot water temperature is very small, or when the hot water use flow rate is too low and only hot water is used. Even if there is a possibility that there is no possibility, it is possible to continue the hot water supply by appropriately operating the auxiliary heat source machine by subjecting the mixed water supply to the auxiliary heating target.

Further, the second flow rate adjusting means may be configured with a closing function (Claim 3 ). In this way, particularly when executing the water supply preheating hot water supply mode, if the second flow rate adjusting means is switched to the closed state, the inflow from the hot water storage direct hot water supply passage to the hot water supply passage is prevented. The hot water supply mode can be executed more reliably. In the case where the second flow rate adjusting means is configured not to have a closing function, for example, a pump is interposed in the auxiliary heating path, and pumping is used to prevent inflow from the hot water storage direct hot water supply path to the hot water discharge path. Is possible. Therefore, by configuring the second flow rate adjusting means with a closing function, it is possible to omit the pump interposition with respect to the auxiliary heating path.

  As described above, according to the hot water storage type hot water supply system of the present invention, auxiliary heating is performed by the auxiliary heat source device for hot water storage in the hot water tank taken out from the auxiliary heating path. The hot water stored in the hot water storage tank taken out from the hot water storage direct hot water path is mixed and mixed. At that time, the flow rate of the auxiliary heating water is set by the first flow rate adjusting means, and the hot water storage direct hot water path is set by the second flow rate adjusting means. By adjusting the flow rate of the hot water storage from each, the hot water can be adjusted to the set hot water temperature. In other words, as a temperature adjustment to the set hot water temperature for finally supplying hot water, mixing with the hot water in the first mixing means is omitted, and the hot water in the hot water tank is mixed. Can do. Thereby, even if the hot water storage temperature in the hot water storage tank is lower than the set hot water supply temperature, hot water storage in the hot water storage tank can be used for 100% hot water supply, while using auxiliary heating with an auxiliary heat source machine. No, the temperature is not adjusted by mixing the feed water, so the amount of combustion in the auxiliary heat source machine can be reduced compared to the case of adjusting the temperature by mixing the feed water, thereby reducing the fuel consumption. Can be minimized and minimized.

In addition , as a control mode for hot water set by a combination of the hot water storage temperature in the hot water tank and the set hot water temperature by the hot water control means, a hot water direct hot water supply mode, a hot water preheating hot water supply mode, and a hot water mixed hot water supply mode are provided. By providing the above, the above-described effect according to the present invention can be specifically realized, particularly by executing the hot water storage mixed hot water supply mode.

According to claim 2 , by providing the second mixing means, in the water supply preheating hot water supply mode or hot water storage hot water supply mode, as an object to be supplied for auxiliary heating to the auxiliary heat source machine, It is possible to select not only the hot water storage that has been taken out, but also a mixture of water supplies. As a result, when the temperature difference between the set hot water supply temperature and the hot water storage temperature is very small, or when the hot water supply flow rate is too low, there is a risk that the auxiliary heat source unit may not be able to operate properly when only the hot water storage is targeted Even so, the auxiliary heat source device can be appropriately burned and operated by making the mixture of the feed water the target of the auxiliary heating, and the hot water supply can be continued.

Furthermore, according to the third aspect , particularly when executing the water supply preheating hot water supply mode, the second flow rate adjusting means is switched to the closed state, thereby preventing the inflow from the hot water storage direct hot water supply path to the hot water supply path. The water supply preheating hot water supply mode can be executed more reliably. In addition, by configuring the second flow rate adjusting means with a closing function, it is possible to omit the pump from the auxiliary heating path.

It is a schematic diagram which shows embodiment of this invention. It is a block diagram concerning hot water supply control. FIG. 2 is a view corresponding to FIG. 1 for explaining an operation in a hot water storage direct hot water supply mode. FIG. 2 is a diagram corresponding to FIG. 1 for explaining an operation in a water supply preheating hot water supply mode. FIG. 2 is a view corresponding to FIG. 1 for explaining an operation in a hot water storage mixed hot water supply mode. It is a related figure of the set hot-water supply temperature and hot water storage temperature for demonstrating the area | region where each hot-water supply mode is performed.

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

  FIG. 1 shows a hot water storage hot water supply system according to an embodiment of the present invention. Reference numeral 2 in the figure denotes a heat collection circuit that collects solar heat as an external heat source and stores it as hot water storage by exchanging heat with hot water in the hot water storage tank 3, and 4 is a water supply circuit that supplies tap water and the like from the outside. Is a hot water supply circuit for supplying hot water to the hot water tap 7 using hot water stored in the hot water tank 3 or hot water after auxiliary heating from the auxiliary heat source unit 6, 8 is a heating circuit using hot water from the hot water supply circuit 5 as a heating heat source, and 9 is the same. A bath reheating circuit 10 uses hot water from the hot water supply circuit 5 as a heat source, and a controller 10 controls the operation of the hot water storage type hot water supply system.

  The heat collection and recovery circuit 2 operates the heat medium circulation pump 21 to operate the heat medium between the solar heat collector 23 and the hot water storage heat exchanger (for example, coil type heat exchanger) 24 in the hot water tank 3 through the heat medium circulation path 22. It is configured to circulate between them. Reference numeral 25 in FIG. 1 denotes an expansion tank interposed in the heat medium circulation path 22. The hot water storage tank 3 is configured in a sealed manner, and a hot water storage temperature sensor 31 for detecting the temperature of the hot water storage is provided at an appropriate place (at least at the top position).

  In the water supply circuit 4, the upstream end of the main water supply channel 41 is connected to an external water pipe or the like, and the downstream end is connected to the bottom of the hot water tank 3 via a check valve 42. A mixed water supply channel 44 branched from the upstream side of the main water supply channel 41 via a check valve 43 is connected to a first mixing valve 55 (to be described later) of the hot water supply circuit 5 so that water can be supplied. A branch water supply path 45 branched from the downstream side of the main water supply path 41 is connected to a second mixing valve 53 (described later) of the hot water supply circuit 5 so that water can be supplied. In addition, the code | symbol 46 of FIG. 1 is a water supply temperature sensor which detects the temperature of the water supplied by the water supply circuit 4. FIG.

  The hot water supply circuit 5 includes an auxiliary heating path 51 through which hot water discharged from the top of the hot water tank 3 is supplied to the auxiliary heat source unit 6 for auxiliary heating, and a hot water storage direct hot water supply path 52 through which the hot water is directly discharged. It is possible to branch into two. The auxiliary heating path 51 leads hot water storage to the auxiliary heat source unit 6 through the second mixing valve 53 and the heating pump 54 as second mixing means capable of mixing with the feed water from the branch water supply path 45, and this auxiliary heat source unit After the auxiliary heating at 6, the first mixing valve 55, which is the first mixing means for final temperature control, is led through the hot water outlet 60. At this time, the first flow rate adjusting valve 56 as the first flow rate adjusting means with the function of closing the hot water (auxiliary heated water) after the auxiliary heating in the hot water outlet 60 between the auxiliary heat source unit 6 and the first mixing valve 55. Has been to pass through. The hot water storage direct hot water supply path 52 is provided with a second flow rate adjusting valve 57 as a second flow rate adjusting means having a closing function in the middle, and a downstream end of the hot water supply path 60 on the downstream side of the first flow rate adjusting valve 56. On the other hand, hot water can be supplied to the first mixing valve 55 by joining at the joining point 50. Reference numeral 58 in FIG. 1 is a hot water supply temperature sensor for detecting the hot water supply temperature of hot water finally supplied at a downstream position of the first mixing valve 55 as a mixing means, and reference numeral 59 is caused by the occurrence of an abnormality in the equipment. It is an avoidance valve for preventing and avoiding hot water supply. Reference numeral 61 denotes a post-heating temperature sensor for detecting the temperature of hot water after auxiliary heating by the auxiliary heat source unit 6.

  The heating circuit 8 heats the circulating heat medium for heating in the heating circuit 81 by liquid-liquid heat exchange in the heat exchanger 82, and the heated circulating heat medium is heated to a high-temperature heating terminal (for example, a bathroom dryer) 83, A low temperature heating terminal (for example, floor heating) 84 is circulated and supplied. The heated hot water discharged from the auxiliary heat source unit 6 is circulated and supplied to the heat source side of the heat exchanger 82 as a heating source (heating heat source) for liquid-liquid heat exchange in the heat exchanger 82. It has become. That is, heated hot water as a heat source is supplied to the heat exchanger 82 as a heating heat source through a heat source supply path 85 branched from the branch point 80 of the outlet hot water path 60 on the downstream side of the auxiliary heat source unit 6, and liquid-liquid heat exchange is performed. The hot water whose temperature has been reduced by the above is led out to the branch water supply passage 45 through the three-way switching valve 86, led to the second mixing valve 53 through this branch water supply passage 45, and then to the auxiliary heat source unit 6 through the heating pump 54. It is circulated so that it is returned and reheated. The circulating heat medium heated by the liquid-liquid heat exchange in the heat exchanger 82 is supplied to the high-temperature heating terminal 83 or the low-temperature heating terminal 84 to radiate heat, and then passes through the expansion tank 87 and the heating pump 88. It is returned to the heat exchanger 82 and reheated.

  The bath reheating circuit 9 operates the reheating pump 91 to circulate hot water in the bathtub 92 through the recirculation path 93 and the heat exchanger 94, and the liquid-liquid heat in the heat exchanger 94 is obtained. It is designed to heat up by exchanging. On the heat source side of the heat exchanger 94, similarly to the heating circuit 8, heated hot water discharged from the auxiliary heat source unit 6 circulates as a reheating heat source through a heat source supply path 95 branched from the branch point 90. The supplied hot water whose temperature has decreased due to the liquid-liquid heat exchange in the heat exchanger 94 is led out to the branch water supply passage 45 through the three-way switching valve 86 and thereafter returned to the auxiliary heat source unit 6 in the same manner as described above. It will be circulated as if it were reheated.

  The operation of each of the circuits 2, 5, 8, and 9 receives the output of the input setting signal and the operation signal from the remote controller 101, and the output of the detection signals from the various temperature sensors 31, 46, 58, and 61. Thus, the operation is controlled by the controller 10. The controller 10 includes various controls such as a heat collection recovery control unit, a hot water supply control unit, a heating control unit, or a reheating control unit for such operation control.

  Hereinafter, the hot water control characteristic of this embodiment will be mainly described with reference to FIG. FIG. 2 particularly shows the hot water supply control unit 102 extracted, and the hot water supply control unit 102 includes three types of hot water supply modes and a hot water supply mode switching processing unit 103 that performs switching processing. The three types of hot water supply modes are a hot water storage direct hot water supply mode 104, a hot water preheating hot water supply mode 105, and a hot water storage mixed hot water supply mode 106.

  In the hot water storage direct hot water supply mode 104, when hot water having a temperature higher than the set hot water temperature is stored in the hot water tank 3, in other words, when there is a sufficient amount of stored heat, the hot water stored in the hot water tank 3 is stored. The hot water is taken out directly as hot water supply. In this case, the second flow rate adjustment valve 57 is opened while the first flow rate adjustment valve 56 is kept closed. When the hot water tap 7 is opened by the user, as shown in FIG. 3 (the portion where the flow is generated is indicated by a thick line), water is supplied from the main water supply path 41 of the water supply circuit 4 to the bottom of the hot water tank 3, The hot water stored in the hot water storage tank 3 is pushed out from the top and discharged to the first mixing valve 55 through the hot water storage direct hot water supply passage 52 and the second flow rate adjustment valve 57. Based on the hot water storage temperature from the hot water storage temperature sensor 31 or the like, a mixing ratio with the water supply from the mixed water supply passage 44 at the first mixing valve 55 is set, and the set hot water supply set in the remote controller 101 by mixing with the water supply Hot water is supplied to the hot-water tap 7 after the temperature is adjusted. Note that the mixing ratio may be feedback controlled based on the hot water supply temperature of the hot water supply temperature sensor 58.

  Both the hot water supply preheating hot water supply mode 105 and the hot water storage mixed hot water supply mode 106 are applied when the hot water storage temperature in the hot water storage tank 3 is lower than the set hot water supply temperature, in other words, when the heat storage amount is insufficient. In any case, the auxiliary heat source unit 6 is combusted to perform auxiliary heating. Among these, in the hot water supply preheating hot water supply mode 105, the hot water temperature in the hot water tank 3 is near or slightly lower than the set hot water temperature, and in the hot water mixed hot water supply mode 106, the hot water storage temperature is considerably lower than the set hot water temperature. Respectively.

  In the case of the feed water preheating hot water supply mode 105, the first flow rate adjustment valve 56 is opened while the second flow rate adjustment valve 57 is kept closed. When the hot water tap 7 is opened by the user, as shown in FIG. 4 (the portion where the flow is generated is indicated by a thick line), water is supplied from the main water supply path 41 of the water supply circuit 4 to the bottom of the hot water tank 3, Hot water in the hot water tank 3 is pushed out from the top and supplied to the auxiliary heat source unit 6 through the heated hot water supply passage 51 and the second mixing valve 53. The auxiliary heat source unit 6 is combusted after detecting a flow of a predetermined flow rate or more by a flow rate sensor (not shown), and the supplied hot water in the warm water state is auxiliary heated to a predetermined temperature or higher. The auxiliary heated hot water is discharged to the first mixing valve 55 through the opened first flow rate adjustment valve 56, and the hot water supply temperature from the hot water supply temperature sensor 61 and the hot water supply temperature from the supply water temperature sensor 46 in the first mixing valve 55. The temperature is adjusted to the set hot-water supply temperature by mixed water at a predetermined mixing ratio based on the above, and hot water is supplied to the hot-water tap 7.

  In addition, in the case of performing auxiliary heating in the auxiliary heat source unit 6, since the temperature of the hot water supplied to the auxiliary heat source unit 6 is too high, inconvenience occurs. In order to avoid this, in the feed water preheating hot water supply mode 105, The water supply from the branch water supply path 45 is mixed with the hot water storage by the second mixing valve 53 to reduce the hot water storage temperature supplied to the auxiliary heat source machine. That is, the auxiliary heat source unit 6 is required to perform a combustion operation exceeding a certain minimum combustion amount. If the combustion amount becomes less than a certain amount, combustion control becomes impossible, and the hot water storage temperature is monitored. A control for mixing a minimum amount of water that does not stop operation in the second mixing valve 53 is also performed. In this sense, it is desirable that the second mixing valve 53 can mix only a minimum amount of water supply. For example, a three-way switching valve can be used instead of the mixing valve. This is not desirable because the water consumption is switched to 100% by switching, and the amount of hot water used is reduced by that amount, leading to a decrease in the degree of utilization of the hot water.

  In the case of the hot water storage mixed hot water supply mode 106, the auxiliary heating is performed by the auxiliary heat source unit 6, but the first mixing valve 55 is not mixed at the final stage, and the warm hot water storage hot water is mixed. The temperature is adjusted up to the hot water supply temperature. For this purpose, the flow rate is adjusted by the first flow rate adjustment valve 56 and the second flow rate adjustment valve 57. That is, in the case of the hot water storage mixed hot water supply mode 106, both the first flow rate adjustment valve 56 and the second flow rate adjustment valve 57 are opened at a predetermined opening. When the hot water tap 7 is opened by the user, as shown in FIG. 5 (the portion where the flow is generated is indicated by a thick line), water is supplied from the main water supply path 41 of the water supply circuit 4 to the bottom of the hot water tank 3. The hot water in the hot water storage tank 3 is pushed out from the top by the hot water supply and discharged into both the heated hot water supply path 51 and the hot water storage direct hot water supply path 52. The hot water stored in the heated hot water supply passage 51 is supplied to the auxiliary heat source unit 6 through the second mixing valve 53, and the auxiliary heat source unit 6 is combusted by detecting a flow rate equal to or higher than a predetermined flow rate in the same manner as in the feed water preheating hot water supply mode. By this combustion operation, the stored hot water in the warm water state is supplementally heated to a predetermined temperature or higher and supplied to the first flow rate adjustment valve 56, and the heated hot water is passed downstream by a flow rate corresponding to the opening degree. . On the other hand, the hot water discharged from the hot water storage direct hot water supply passage 52 is supplied to the second flow rate adjusting valve 57 and passed downstream by the flow rate corresponding to the opening degree, and merged with the auxiliary hot water at the junction 50. The hot water that has been mixed and temperature-controlled by mixing passes through the first mixing valve 55, that is, without being mixed with the water supplied from the mixed water supply channel 44, is supplied to the hot water tap 7. By executing the hot water storage mixing mode 106 as described above, the hot water storage (heat storage) in the hot water storage tank 3 can be utilized to the maximum (100%). In addition, since the temperature is not adjusted by mixing the feed water, the amount of combustion in the auxiliary heat source unit 6 is compared with the case where the temperature is controlled by mixing the feed water (for example, in the case of the chair preheating hot water supply mode 105). As a result, fuel consumption can be reduced.

  In this hot water storage mixed hot water supply mode 106, the hot water after auxiliary heating is mixed with hot water storage instead of the hot water to adjust the temperature to the set hot water supply temperature. When there is not much temperature difference from the temperature, or when the opening degree of the hot-water tap 7 is small and the hot water supply flow rate is small, the flow rate passing through the auxiliary heat source unit 6 is considerably small, and is necessary for the combustion operation. This could cause the minimum operating flow rate to be exceeded. In this case, it is possible to continue the hot water supply by switching to the water supply preheating hot water supply mode 105 described above.

  As described above, if the above three types of hot water supply modes are switched and executed by the hot water supply mode switching processing unit 103 in accordance with the relationship between the set hot water supply temperature set when hot water is used and the hot water storage temperature at that time. Good. The trend of hot water storage temperature may be affected by the daily weather, but the trend of hot water storage temperature is mainly determined by seasonal changes. FIG. 6 shows a guide for switching between hot water supply modes. In the combination of the set hot water supply temperature and the hot water storage temperature, three regions are set corresponding to the three types of hot water supply modes. If the hot water storage temperature is considerably higher than the set hot water supply temperature, the hot water storage mode 104 may be switched to the hot water storage direct hot water supply mode 104. On the contrary, if the hot water storage temperature is considerably lower than the set hot water supply temperature, Switching to mode 106 may be executed. If the hot water storage temperature is lower than the set hot water temperature, but is close, basically the water supply preheating hot water supply mode 105 may be selected and executed, or the water supply preheating hot water supply mode 105 may be selected or switched, or hot water mixing is performed. Whether to select / switch the hot water supply mode 106 may be determined in consideration of the hot water supply use flow rate at that time.

  As an example of the standard of hot water supply mode switching shown in FIG. 6, when the hot water set temperature is 40 ° C., for example, if the hot water storage temperature is 40 ° C. or higher, the hot water storage mode is switched to the hot water storage direct hot water mode 104 and executed. If it is less than 30 ° C. and higher than 30 ° C., it is switched to the hot water preheating hot water supply mode 105 and executed.

<Other embodiments>
In addition, this invention is not limited to the said embodiment, Various other embodiments are included. That is, in the above-described embodiment, the case where the external heat source that is the heat recovery target that stores hot water in the hot water storage tank 3 is converted to solar heat, but is not limited thereto, and is not limited to this, but a gas engine (engine cooling water exhaust heat) is used as the external heat source. The fuel cell (cooling water exhaust heat) or the heat pump (refrigerant exhaust heat) may be used to store hot water and store the heat. In such a case, the present invention can be applied.

  Further, the heat storage by the heat collection and recovery circuit 2 is performed by exchanging heat with the hot water storage by the hot water storage heat exchanger 24 installed in the hot water storage tank 3, but not limited thereto, for example, the hot water storage of the hot water storage tank 3. A circulation path for extracting (hot water) from the bottom and returning it to the top is installed, and heat exchange with a heat medium collected (heat recovery) by a heat recovery circuit such as the heat collection circuit 2 is performed in the middle of the circulation path. You may make it heat-store by this.

  In the hot water storage type hot water supply system of the above embodiment, the heating pump 54 is interposed. However, when the second flow rate adjustment valve 57 is configured with a closing function, the heating pump 54 can be omitted. In the case where the second flow rate adjustment valve 57 is not provided with a closing function but is configured only with a normal flow rate adjustment function, inflow from the hot water storage direct hot water supply path 52 should be prevented when the hot water preheating hot water supply mode is executed. The heating pump 54 may be operated.

  In the hot water storage type hot water supply system of the above embodiment, the first flow rate adjustment valve has a closing function. However, when the heating circuit 8 and the bath reheating circuit 9 are not attached, it is not necessary to have the closing function. It may have a flow rate adjusting function. That is, when the hot water supplementarily heated from the auxiliary heat source unit 6 is circulated and supplied to the heat source circulation paths 85 and 95 as the heat source, the first flow rate adjustment valve 56 needs to be closed, but the heat source circulation path This is because if the heat source does not need to be circulated and supplied to 85 and 95, the closing function becomes unnecessary. Note that when the hot water storage direct hot water supply mode is executed, the auxiliary heating path 51 side has resistance due to the presence of the auxiliary heat source unit 6 and the like. The hot water stored in the tank 3 flows to the hot water storage direct hot water supply path 52. For this reason, the 1st flow regulating valve 56 does not necessarily need to have a closing function, and is not an essential matter.

3 Hot water storage tank 6 Auxiliary heat source machine 7 Hot water tap 24 Hot water storage heat exchanger 51 Auxiliary heating path 52 Hot water storage direct hot water path 53 First mixing valve (first mixing means)
55 Second mixing valve (second mixing means)
56 1st flow control valve (1st flow control means)
57 Second flow rate adjusting valve (second flow rate adjusting means)
60 Hot water supply passage 102 Hot water supply control unit (hot water supply control means)
103 Hot water supply mode switching processing unit 104 Hot water storage direct hot water supply mode 105 Hot water preheating hot water supply mode 106 Hot water storage mixed hot water supply mode

Claims (3)

A hot water storage tank that stores heat as a hot water storage by recovering heat from an external heat source, an auxiliary heat source machine, an auxiliary heating hot water that is subheated by this auxiliary heat source machine, or a hot water taken out from the hot water storage tank. A hot water storage type hot water supply system comprising first mixing means for supplying hot water after mixing,
An auxiliary heating path for supplying hot water taken out from the top of the hot water storage tank to the auxiliary heat source machine for auxiliary heating, and a hot water supply path from the auxiliary heat source machine are supplied to the first mixing means. First flow rate adjusting means for adjusting the flow rate of the auxiliary heating hot water, and hot water taken out from the top of the hot water storage tank at a position downstream of the first flow rate adjusting means and upstream of the first mixing means. While comprising a hot water storage direct hot water supply path that joins the hot water supply path at the side position, and a second flow rate adjusting means that adjusts the flow rate of the hot water storage that is interposed in the hot water storage direct hot water supply path and joins the hot water supply path,
Furthermore, it has hot water supply control means,
This hot water control means is a control mode set for hot water operation in the combination of the hot water temperature in the hot water tank and the set hot water temperature, and the stored hot water temperature is divided into high temperature, medium temperature and low temperature in comparison with the set hot water temperature. Based on the classification, hot water storage direct hot water supply mode executed when the hot water storage temperature is high, hot water preheating hot water supply mode executed when the hot water storage temperature is medium, and hot water storage executed when the hot water storage temperature is low With mixed hot water supply mode,
The hot water storage direct hot water supply mode is configured to mix hot water in the first mixing means with respect to the hot water taken out from the hot water storage tank through the hot water storage direct hot water path and adjust the temperature to the set hot water temperature, and then supply hot water.
In the hot water preheating hot water supply mode, the hot water storage taken out from the hot water storage tank through the auxiliary heating path is auxiliary heated by the auxiliary heat source device, and the auxiliary heating hot water is mixed with the hot water in the first mixing means to the set hot water supply temperature. It is configured to supply hot water after temperature control,
In the hot water mixed hot water supply mode, the hot water taken out from the hot water tank through the auxiliary heating path is auxiliary heated by the auxiliary heat source device, and the hot water taken out from the hot water storage tank through the direct hot water supply path is joined to the auxiliary heated auxiliary hot water. to the time of the merging, that is configured to the hot water supply in terms of the temperature control so as to set the hot water temperature by both of the flow rate adjustment of the first flow rate adjusting means and the second flow rate adjusting means,
Savings hot water heater system, characterized in that. The hot water storage hot water supply system according to claim 1 ,
A second mixing means is interposed in the auxiliary heating path, and the second mixing means mixes the hot water taken out from the top of the hot water storage tank and the external water supply, and then supplies the auxiliary heat source machine with the auxiliary heat source. Configured to be supplied for auxiliary heating,
In the water supply preheating hot water supply mode or the hot water storage mixed hot water supply mode, not only the hot water taken out from the hot water storage tank but also the water supplied by the second mixing means as a target to be supplied to the auxiliary heat source machine for auxiliary heating A hot water storage hot water system that can be selected. The hot water storage hot water supply system according to claim 1 or 2 ,
The hot water storage hot water supply system, wherein the second flow rate adjusting means is configured with a closing function.

Images