JP2005315524A - Heat storage device of hot water storage tank - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve the problems resulting from heat radiation during boiling operation wherein a heat storage amount in a hot water storage tank is not sufficient and a large variation occurs in temperature of a hot water for heat storage. <P>SOLUTION: This heat storage device A of a hot water storage tank comprises a heating means heating a hot water flowing in a circulation passage 2 and a control means 4 performing the heating control of the hot water by the heating means 3 so that a boiling operation for storing heat in the hot water storage tank 1 based on data on target boiling temperature for a specified boiling time for the hot water in the hot water storage tank 1. When the boiling operation is performed, the control means 4 obtains a temperature down amount at fixed or unfixed intervals from a time when a hot water heated by the heating means 3 is heated to a time when the boiling operation is completed, and controls to change a heating temperature so as to heat the hot water at a temperature obtained by adding a temperature corresponding to the temperature down amount to the target boiling temperature. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a hot water storage tank heat storage device of a type that stores heat by storing hot water heated using a heat pump or the like in a hot water storage tank.

  An example of a basic configuration of a conventional hot water storage tank heat storage device is shown in FIG. 7 (see, for example, Patent Documents 1 and 2). The hot water storage tank storage device B shown in the figure uses hot water in the hot water storage tank 90 to flow out from the outlet 92a to the circulation path 92 using the circulation pump 91, and then this hot water is supplied from the reduction port 92b to the hot water storage tank 90. It is configured to be able to return to the inside. The circulation path 92 is provided so as to pass through the heat exchanger (condenser) 93 a of the heat pump 93.

  According to such a configuration, the hot water can be heated by the heat pump 93 and returned to the hot water storage tank 90 while the hot water flows out from the hot water storage tank 90 to the circulation path 92. Accordingly, the hot water heated by the heat pump 93 can be sequentially stored in the hot water storage tank 90 from the upper part to the lower part of the hot water storage tank 90 to achieve heat storage. The boiling operation for achieving such heat storage is generally performed at night when the electricity rate is low, and the stored hot water is used during the day.

  Conventionally, when the boiling operation is performed, the heating temperature of the hot water by the heat pump 93 is the same as the target boiling temperature of the hot water, and the temperature is constant from the start to the end of the operation. More specifically, when the target boiling temperature of the hot water is, for example, 80 ° C., the heating temperature of the hot water by the heat pump 93 is also the same 80 ° C., and the heating temperature is constant during the boiling operation period. It was supposed to remain.

  However, the above-described prior art has the following problems.

  First, when hot water heated by the heat pump 93 is returned to the hot water storage tank 90, the temperature of the hot water decreases due to heat radiation over time. Therefore, in the prior art, the hot water heated immediately before the end of the boiling operation can be set to the boiling target temperature or a temperature close thereto, but the hot water heated in the initial stage of the boiling operation is stored in the hot water storage tank. In 90, the temperature may be considerably lower than the boiling target temperature. The hot water storage tank 90 has a structure in which the heat insulating property is enhanced by being covered with a heat insulating material, for example, but the boiling operation for performing heat storage is performed for a long time of several hours or more, for example. Usually, the outside temperature may be very low in winter and the like, so it is often difficult to avoid the temperature drop of the hot water as described above. As a result, in the prior art, the actual heat storage amount in the hot water storage tank 90 is lower than the planned heat storage amount, and there is a case where the heat storage amount is insufficient during use.

Secondly, when hot water is stored in the hot water storage tank 90, preferably, as shown in FIG. 8 (a), the temperature distribution of the heated hot water (dotted portion) is uniform, It is desired that a temperature boundary layer Ra is clearly formed between the hot water and the non-heated low-temperature water. When the hot water is discharged from the hot water storage tank 90, the hot water storage tank 90 is filled with water from an inlet pipe 94a connected to the lower portion of the hot water storage tank 90, and the water pushes the hot water in the hot water storage tank 90 upward. In the state shown in FIG. 8 (a), only the hot water can be appropriately discharged by the water-filling action of the low-temperature water. . On the other hand, in the above-described prior art, the amount of temperature drop due to heat radiation increases as hot water heated near the start timing of the boiling operation increases. For example, as shown in FIG. The temperature of the (dot pattern) is higher at the upper part and lower at the lower part. In this case, the mixed layer Rb is formed in a wide state between the heated hot water and the non-heated low-temperature water, and the temperature boundary layer is not clearly formed. Therefore, in the above-described conventional technology, it may be difficult to appropriately and efficiently discharge hot water only from the hot water storage tank 90. Further, as described above, when the temperature distribution of the hot water stored in the hot water storage tank 90 is non-uniform, the so-called remaining hot water amount display for measuring the temperature and amount of the hot water and displaying the values is performed. In some cases, the measurement error becomes large, and there is a problem that accurate display cannot be performed.
Japanese Patent Laid-Open No. 2002-174459 JP 2002-181385 A

  The present invention has been conceived under such circumstances, and the amount of heat stored in the hot water storage tank after the boiling operation is less than the expected amount due to heat dissipation during the boiling operation period. It is an object of the present invention to provide a hot water storage tank heat storage device that can eliminate or suppress the problem of large variations in the temperature of hot water for heat storage.

  The present invention does not uniformly heat the hot water at the target boiling temperature, but considers the amount of temperature drop during the subsequent boiling operation of the hot water, and boiles the amount corresponding to the temperature drop. This is based on a new idea of heating the hot water at a temperature higher than the target temperature to eliminate the shortage of heat storage due to heat dissipation and the uneven temperature distribution. Specifically, the present invention takes the following technical means.

  The hot water storage tank heat storage device provided by the first aspect of the present invention heats the hot water storage tank, a circulation path for taking out the hot water in the hot water storage tank and returning it to the hot water storage tank, and hot water flowing through the circulation path. The heating means and a heating operation for performing heat storage in the hot water storage tank based on data of a target boiling temperature and a required boiling time for hot water in the hot water storage tank are executed. And a control means for controlling the heating of the hot water by the hot water storage tank heat storage device, wherein the control means, when the boiling operation is performed, from the time of heating the hot water heated by the heating means The amount of temperature drop until the end of the boiling operation is obtained at a constant or indefinite period, and the temperature corresponding to this amount of temperature drop is added to the boiling target temperature. It is characterized by being configured to perform the change control of the heating temperature so as to heat.

  According to such a configuration, when hot water is heated by the heating means, a temperature that is higher than the boiling target temperature by a temperature corresponding to the amount of temperature decrease due to heat radiation from the heating time to the end of the boiling operation. Therefore, when the boiling operation is finished, the heated hot water does not become a temperature considerably lower than the boiling target temperature due to heat radiation, and the temperature is set as the boiling target temperature. The temperature can be substantially the same. Therefore, unlike the prior art, it is appropriately avoided that the amount of heat stored in the hot water storage tank is significantly lower than the target amount of stored heat. Moreover, according to the said structure, the whole hot water heated by the heating means and stored in the hot water storage tank is equalized to the boiling target temperature or a temperature close thereto. Therefore, in the hot water storage tank, it is possible to appropriately form a temperature boundary layer between the heated hot water and the non-heated low temperature water, and when the hot water is discharged from the hot water tank to the outside. Moreover, only hot water can be appropriately and efficiently discharged. Furthermore, when the temperature of the heated hot water is made uniform as described above, the temperature of the hot water is stabilized, and the temperature of the hot water and the amount of storage can be accurately measured. The amount of remaining hot water can be displayed properly.

  In a preferred embodiment of the present invention, when the control means obtains the amount of temperature drop, the remaining time from the time of heating the hot water to the scheduled end time of the boiling operation, the heat dissipation coefficient of the hot water storage tank, and Based on data of the difference between the boiling target temperature and the external temperature of the hot water storage tank, a temperature drop amount of hot water in the hot water storage tank is obtained, and this value is calculated from the time of heating the hot water to the end of the boiling operation. It is configured to be included in the temperature drop amount up to. According to such a configuration, it is possible to determine the amount of temperature drop from when the heated hot water is stored in the hot water storage tank to the end of the boiling operation fairly accurately, and the hot water at the end of the boiling operation is obtained. It is suitable to bring the actual temperature of the water closer to the boiling target temperature.

  In a preferred embodiment of the present invention, the control means further obtains a temperature drop amount of the hot water in the circulation path, and sets this value as a temperature drop amount from the heating time of the hot water to the end of the boiling operation. Is configured to include. According to such a configuration, not only the temperature drop after hot water is stored in the hot water storage tank, but also the temperature drop caused by the hot water passing through the circulation path is taken into account. Since the amount of descent is obtained, the actual temperature of hot water at the end of the boiling operation can be brought closer to the boiling target temperature more accurately.

  In a preferred embodiment of the present invention, a plurality of hot water storage tanks are provided as the hot water storage tanks, and the plurality of hot water storage tanks are connected in series so that hot water inside them can be circulated through the circulation path. Has been. According to such a structure, the heat storage amount can be increased by providing a plurality of hot water storage tanks. The plurality of hot water storage tanks are connected in series, and when the amount of temperature drop after the heated hot water is stored in these hot water storage tanks, the plurality of hot water storage tanks are combined into one hot water storage tank. It can be regarded as a tank, and the process for obtaining the temperature drop can be easily performed.

  The hot water storage tank heat storage device provided by the second aspect of the present invention heats the hot water storage tank, a circulation path for taking out the hot water in the hot water storage tank and returning it to the hot water storage tank, and hot water flowing through the circulation path. The heating means and a heating operation for performing heat storage in the hot water storage tank based on data of a target boiling temperature and a required boiling time for hot water in the hot water storage tank are executed. A hot water tank heat storage device comprising: a control means for performing heating control of hot water using the hot water heating tank, wherein the control means is configured to start the boiling operation of hot water heated at the start of the heating operation. The hot water is heated at a temperature obtained by adding a temperature corresponding to the temperature drop until the end of the heating to the boiling target temperature, and thereafter, it is close to the scheduled end time of the boiling operation. Is characterized by being configured to perform the heating temperature control of the heating temperature of the hot water is brought close to the boiling target temperature according to Ku.

  Even in such a configuration, when hot water is heated by the heating means, the temperature is higher than the boiling target temperature by a temperature corresponding to the amount of temperature decrease due to heat radiation from the heating to the end of the boiling operation. Heated. Therefore, as in the case of the hot water storage tank heat storage device provided by the first aspect of the present invention, when the boiling operation is completed, the temperature of the heated hot water is the same as or substantially the same as the boiling target temperature, It is possible to prevent the amount of heat stored in the hot water storage tank from significantly lowering the target amount. In addition, the temperature of the hot water stored in the hot water storage tank is equalized to the boiling target temperature or a temperature close thereto, so that the heated hot water can be properly discharged. It is also possible to stabilize the temperature of the hot water and optimize the so-called residual hot water display.

  Other features and advantages of the present invention will become more apparent from the following description of embodiments of the present invention with reference to the accompanying drawings.

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

  FIG. 1 shows an embodiment of a hot water storage tank heat storage device according to the present invention. The hot water storage tank heat storage device A of this embodiment includes a hot water storage tank 1, a circulation path 2 provided with a circulation pump 20, a heat pump 3, and a main control unit 4.

  The hot water storage tank 1 is for storing hot water, and is configured so that heat is suppressed as much as possible by covering the periphery thereof with a heat insulating material (not shown). A water inlet pipe 50 is connected to the lower part of the hot water storage tank 1 and a hot water outlet pipe 51 is connected to the upper part of the hot water storage tank 1, and water is stored in the hot water storage tank 1 by entering water into the hot water storage tank 1. The hot water that has been discharged flows out into the tap pipe 51. The hot water outlet pipe 51 is provided with a mixing valve 52 to which the branch pipe 50a of the water inlet pipe 50 is connected. By the action of the mixing valve 52, hot water from the hot water storage tank 1 and water from the branch pipe 50a are desired. They are mixed at a ratio and supplied downstream of the hot water outlet pipe 51.

  Both ends of the circulation path 2 are connected to the lower outlet 21a and the upper reduction port 21b of the hot water storage tank 1, and the hot water in the hot water storage tank 1 can be circulated by a fixed path by driving the circulation pump 20. It is a simple pipe line. A part of the circulation path 2 passes through a heat exchanger (condenser) 30 of the heat pump 3, and hot water flowing through the circulation path 2 is heated via the heat exchanger 30 and then flows into the hot water storage tank 1. It is like that.

  The heat pump 3 corresponds to an example of the heating means in the present invention. As the heat pump 3, a conventionally known heat pump 3 can be used, and details thereof are omitted. In addition to the heat exchanger (condenser) 30 described above, a compressor 31, an expansion valve 32, and an evaporator 33 are used. It has. The heat pump 3 has an auxiliary control unit 34 for controlling the operating state of the heat pump 3 in accordance with a command from the main control unit 4. The auxiliary control unit 34 is connected to a temperature sensor Sa for measuring the temperature of hot water at the outlet portion of the heat exchanger 30 and a temperature sensor Sb for measuring the outside air temperature. These temperature sensors Sa, Temperature data measured using Sb is transmitted to the main control unit 4. These temperature sensors Sa and Sb are configured using, for example, a thermistor, and this is the same for other temperature sensors Sc to Se described later. The temperature measured using the temperature sensor Sa corresponds to the hot water heating temperature by the heat pump 3.

  The main control unit 4 corresponds to an example of the control means in the present invention, and is constituted by a microcomputer including a CPU and a memory attached to the CPU. The main control unit 4 responds to programs and other data recorded in the memory, and switch operation of a remote control operation panel 49 connected to the main control unit 4 and installed in an appropriate place such as indoors. Thus, the entire operation control of the hot water storage tank heat storage device A and predetermined arithmetic processing are executed. The main controller 4 includes a plurality of temperature sensors Sc for measuring the temperature of hot water at a plurality of locations in the hot water storage tank 1, and the temperature of hot water introduced into the circulation path 2 in the vicinity of the outlet 21a of the circulation path 2. A temperature sensor Sd for measuring the temperature and a temperature sensor Se for measuring the temperature of the hot water returned to the hot water storage tank 1 in the vicinity of the reducing port 21b are connected so that a predetermined temperature can be determined using these. It has become. The main control unit 4 controls the driving of the circulation pump 20 and the heat pump 3 to control the boiling target when performing a boiling operation for storing heat using, for example, a so-called late-night power with a low charge. Control is performed to store a target amount of hot water at a predetermined time by a predetermined target time. However, in the present embodiment, as will be described later, the main control unit 4 periodically calculates the temperature drop amount of the hot water due to heat dissipation during the boiling operation, and heats the hot water according to the temperature drop amount. The temperature is changed and controlled, and this is a feature. The hot water heating temperature is changed, for example, by controlling the driving of the circulation pump 20 and adjusting the flow rate of the hot water in the circulation path 2.

  Next, the operation of the hot water storage tank heat storage device A having the above-described configuration and an example of the operation procedure of the main control unit 4 will be described with reference to the flowchart shown in FIG.

  First, when the boiling operation for storing heat is set to ON (S1: YES), the main control unit 4 confirms the boiling condition (S2). The items of the heating condition include a boiling target temperature Ta, a heating amount L, and the like. These conditions are set, for example, when the user operates the remote control operation panel 49. Alternatively, for example, the main control unit 4 may be provided with a learning function so that the main control unit 4 determines the past based on the usage status of the hot water storage tank heat storage device A. Next, the main control unit 4 detects the outside air temperature Tb and the temperature (water temperature) Tc of the hot water in the hot water storage tank 1 (S3). This detection process is performed by receiving data on the outside air temperature using the temperature sensor Sb from the auxiliary control unit 34 or detecting the temperature of each part of the hot water in the hot water storage tank 1 using the plurality of temperature sensors Sc. This can be done by calculating the average value.

  Thereafter, the main control unit 4 calculates the required boiling time H1 based on the above data (S4). Here, the boiling required time H1 is a time required to perform heat storage satisfying the above-mentioned boiling condition, and this time becomes shorter as the capacity of the heat pump 3 is larger. The calculation of the required boiling time H1 is performed using, for example, an equation of H1 = (Ta−Tc) × L / C. Here, C is the work amount of the heat pump 3. As a specific example, the boiling target temperature Ta is 80 ° C., the hot water temperature Tc is 15 ° C., the boiling amount L is 300 liters, and the work amount C of the heat pump 3 is 4.5 kWh (4.5 × 860 Kcal). In this case, when these are applied to the above equation, the boiling time H1 is about 5 hours. When the required heating time H1 is determined, the scheduled start time of the boiling operation is also determined based on the scheduled end time of the boiling operation. The scheduled end time of the boiling operation can be appropriately changed by operating a switch or the like. For example, the end time of late-night power (for example, 7:00 am) or a slightly earlier time It is said. Assuming that the scheduled boiling time is 7:00 am, in the above example, 2:00 am is the scheduled start time for the boiling operation. However, in practice, the scheduled start time may be set a little earlier in view of an appropriate margin time in consideration of heat dissipation factors and other various circumstances.

  The main control unit 4 starts the heating operation by starting driving the heat pump 3 and the circulation pump 20 at the scheduled start time of the boiling operation (S5: YES). 2, the temperature drop amount ΔT1 of the heated hot water in the hot water storage tank 1 and the temperature drop amount ΔT2 caused by the circulation path 2 are calculated, and these values are calculated. Based on this, the hot water heating temperature Tx by the heat pump 3 is calculated (S9). Then, the main control unit 4 adjusts the flow rate of the circulation path 2 by drivingly controlling the circulation pump 20 so that the hot water is heated at the calculated heating temperature Tx (S10).

  The above point will be described in detail. In order to calculate the hot water heating temperature Tx, the temperature drop ΔT1 in the hot water storage tank 1 and the temperature drop ΔT2 in the circulation path 2 are obtained in advance (S7, S8) When calculating the temperature drop ΔT1, prior to that, the heat dissipation time H2 of the hot water heated by the heat pump 3 is calculated (S6). This heat radiation time H2 is the time from when the hot water is actually heated until the boiling operation is completed. That is, the heat radiation time H2 is obtained by the equation H2 = H1-H3 (H3 is an actual boiling operation time). Since H3 is zero at the start of the boiling operation, the heat release time H2 at the start of the boiling operation is the same as the required boiling time H1. The heat radiation time H2 gradually decreases as the heating operation proceeds and the time elapses. The main control unit 4 calculates the temperature drop amount ΔT1 based on the heat dissipation time H2. This amount of temperature drop ΔT1 is obtained by, for example, an equation of ΔT1 = (Ta−Tb) × H2 × γ1. Here, γ1 is a heat dissipation coefficient, and is a constant specific to the hot water storage tank 1 of the hot water storage tank heat storage device A and the same type hot water storage tank. This value can be obtained by, for example, experiments. As an example of specific numerical values, if the boiling target temperature Ta is 80 ° C, the outside air temperature Tb is 16 ° C, the heat radiation time H2 is 5 hours, and the heat radiation coefficient γ1 is 0.006, the temperature drop amount ΔT1 is about 1.9 deg. This value is the temperature at which the hot water heated at the start of the boiling operation decreases in the hot water storage tank 1 by the boiling operation end time.

  The temperature drop amount ΔT2 in the circulation path 2 is obtained by, for example, an equation of ΔT2 = (Ta−Tb) × γ2. Here, γ2 is a heat dissipation coefficient as with γ1, but this heat dissipation coefficient γ2 depends on the construction conditions of the hot water storage tank storage device A, such as the piping length of the circulation path 2, and the hot water storage tank. This is a constant specific to the heat storage device A. This heat dissipation coefficient γ2 is preferably changeable by a learning function of the main control unit 4 or a switch operation of the remote control operation panel 49 (this is the same for the heat dissipation coefficient γ1). As an example of specific numerical values, assuming that the boiling target temperature Ta is 80 ° C, the outside air temperature Tb is 16 ° C, and the heat dissipation coefficient γ2 is 0.02, the temperature drop ΔT2 is about 1.2 deg. It becomes. In calculating the temperature drop amount ΔT2, it is not necessary to consider the heat radiation time H2.

  The total value of the temperature drop amounts ΔT1 and ΔT2 described above corresponds to the amount by which the heated hot water drops by the end of the boiling operation. The main control unit 4 sets a value obtained by adding the total value to the boiling target temperature Ta as the hot water heating temperature Tx. That is, the heating temperature Tx is obtained by the equation Tx = Ta + ΔT1 + ΔT2. This will be explained by applying to the above-described specific example. When the boiling target temperature Ta is 80 ° C. and the temperature drop amounts ΔT1 and ΔT2 are 1.9 deg and 1.2 deg, respectively, the heating temperature Tx is 83.1 °. C. Therefore, at the beginning of the boiling operation, control is performed so that hot water is heated at the heating temperature Tx. When this control is finished, the main control unit 4 accumulates the actual boiling operation time H3 (S11), and then periodically repeats the series of processes described above (S12: NO, S6 to S11), When the accumulated time H3 becomes the required boiling time H1, the calculation is terminated as a completion of boiling (S12: YES). Although omitted in FIG. 2, it is desirable to provide a step of confirming that a predetermined amount (for example, 300 liters) of hot water is actually boiled. When the amount of boiling has not reached the predetermined amount, ΔT1 = 0 and the operation is continued until the predetermined amount is reached. Whether or not a predetermined amount has been boiled can be easily determined by temperature detection using the temperature sensor Sc of the hot water storage tank or the temperature sensor Sd of the circulation path. Further, as another determination method, it is also possible to use a method in which the circulation heating amount is confirmed from the integrated value of the circulation amount calculated from the heating capacity and the inlet / outlet temperature difference of the heating source 30 and is determined based on this.

  In the series of processes described above, the temperature drop amount ΔT1 in the hot water storage tank 1 calculated by the main control unit 4 gradually decreases as time elapses after the boiling operation is started. For example, immediately before the end of the boiling operation, the heat release time H2 of the heated hot water is almost zero, and the temperature drop amount ΔT1 calculated at that time is almost zero as well. For this reason, as shown in FIG. 3, the heating temperature Tx is initially 83.1 ° C., for example, but gradually decreases with the passage of time, immediately before the end of the boiling operation. Is higher than the boiling target temperature Ta (80 ° C.) by a temperature corresponding to the temperature drop amount ΔT2 in the circulation path 2.

  All the hot water stored in the hot water storage tank 1 by the above-described boiling operation is heated at a temperature higher than the boiling target temperature Ta by a temperature corresponding to the temperature drop amount from the time of heating to the end of the boiling operation. Therefore, at the end of the boiling operation, the total amount of heated hot water is equal to or substantially the same as the boiling target temperature Ta regardless of the heating time. Therefore, there is no possibility that the actual heat storage amount will be insufficient as compared with the planned heat storage amount. Moreover, if the temperature of the heated hot water is made uniform, a preferred hot water storage mode shown in FIG. 8 (a) or a mode close thereto is obtained, and heated hot water and non-heated low temperature water During this time, the temperature boundary layer is clearly formed, and it is difficult to cause a problem that a large amount of mixed water of high-temperature water and low-temperature water is discharged when hot water is discharged.

  Further, in the present embodiment, not only the temperature drop amount ΔT1 in the hot water storage tank 1 but also the temperature drop amount ΔT2 in the circulation path 2 is considered as the temperature drop amount of the heated hot water. For this reason, the value of the temperature drop of the hot water determined by the main control unit 4 becomes an accurate value that is very close to the actual temperature drop, and the actual heat storage amount at the end of the boiling operation is a large error with respect to the target heat storage amount. Can be prevented.

  However, in the present invention, the heating temperature Tx may be determined by considering only the temperature drop amount ΔT1 in the hot water storage tank 1, for example, as the temperature drop amount of hot water without considering the temperature drop amount ΔT2 in the circulation path 2. Absent. In this case, the calculation process of step S8 shown in FIG. 2 is not performed, and the temperature drop amount ΔT2 = 0 in the calculation of the heating temperature Tx of step S9. According to such control, for example, as shown in FIG. 4, the heating temperature Tx immediately before the completion of the boiling operation is the same as the boiling target temperature Ta, which is different from the case shown in FIG. The heating temperature Tx is also added to the boiling target temperature Ta by an amount corresponding to the amount of temperature drop in consideration of heat dissipation in the hot water storage tank 1, so that the actual heat storage amount is much lower than the target heat storage amount. Is appropriately avoided. Further, the temperature of the hot water stored in the hot water storage tank 1 can be made uniform.

  In the present invention, when the calculation process of the temperature drop amounts ΔT1 and ΔT2 and the calculation process of the heating temperature Tx are periodically performed, the specific span of the period is not particularly limited. If the span is relatively long (for example, span of several minutes to several tens of minutes), for example, as shown in FIG. 5, the heating temperature Tx is controlled stepwise. In this case, as shown in FIG. 3 and FIG. 4, although the accuracy is lower than the case where the heating temperature Tx is controlled substantially linearly, the heat storage amount is insufficiently suppressed as compared with the conventional technique. In addition, the temperature distribution of the heated hot water can be made uniform, and the present invention may have such control contents. Further, although the above-described calculation of the temperature drop of the hot water and the heating temperature Tx and the control for responding to the heating temperature Tx are preferably performed at a constant cycle, they are not limited to this. For example, the main control unit 4 may be executed at an indefinite period for securing a time for executing another control process. Furthermore, in the present invention, the heating temperature Tx is not necessarily limited to the sum of the hot water temperature drop ΔT1 (or a value obtained by adding ΔT2) calculated by calculation and the boiling target temperature Ta. There is no. For example, even if the heating temperature Tx is finely specified within a range exceeding the adjustment capability of the hot water heating temperature in the hot water storage tank storage device, it is difficult to control the temperature corresponding to such a fine specification. In consideration of the ability to adjust the heating temperature, an approximate value can be obtained.

  FIG. 6 shows another embodiment of the hot water storage tank heat storage device according to the present invention. In the figure, the same or similar elements as those of the previous embodiment shown in FIG. 1 are denoted by the same reference numerals as those of the previous embodiment.

  The hot water storage tank heat storage device Aa shown in FIG. 6 includes two hot water storage tanks 1A and 1B, and is configured to increase the amount of stored hot water. The lower part of the hot water storage tank 1A and the upper part of the hot water storage tank 1B are connected to each other via a pipe part 19 so that the hot water in these two hot water storage tanks 1A, 1B forms a closed loop that can circulate through the circulation path 2. It is configured. In each of the hot water storage tanks 1A and 1B, a plurality of temperature sensors Sc for measuring the temperature of the hot water are provided.

  In the hot water storage tank heat storage device Aa, hot water flowing out from the outlet 21a at the lower part of the hot water storage tank 1B into the circulation path 2 is heated by the heat pump 3, and then into the hot water storage tank 1A from the reducing port 21b at the upper part of the hot water storage tank 1A. Supplied. Therefore, the heated hot water is stored from the upper part to the lower part of the hot water storage tank 1A, and when the hot water storage tank 1A is full, it is stored in the hot water storage tank 1B via the piping part 19. For this reason, in the present embodiment, after determining the value of the heat dissipation coefficient γ1 by regarding the two hot water storage tanks 1A, 1B and the entire pipe portion 19 connecting them as one hot water storage tank, If the temperature drop amount when hot water is stored inside them is calculated, and the control is performed by obtaining the heating temperature of the hot water by the heat pump 3, the intended effect of the present invention can be obtained. This is not limited to the case where there are two hot water storage tanks, and the same applies when three or more hot water storage tanks are provided.

  The content of the present invention is not limited to the embodiment described above. The specific configuration of each part of the hot water storage tank heat storage device according to the present invention can be varied in design in various ways.

  For example, in the above-described embodiment, the temperature drop amount until the heated hot water reaches the end of the boiling operation is periodically obtained, but control different from this can be performed. That is, in the present invention, at the start of the boiling operation, the temperature corresponding to the temperature drop amount of the hot water heated at the start of the operation until the end of the boiling operation and the boiling target temperature are added. The hot water is heated at a temperature, and then the heating temperature of the hot water is brought closer to the boiling target temperature as the boiling operation is scheduled to end without performing a temperature drop calculation process. You may comprise so that heating temperature control may be performed. Even when such control is performed, as a result, the change in the hot water heating temperature can be the same as the change in the hot water heating temperature Tx shown in FIGS. Thus, the effect intended by the present invention can be obtained.

  In the present invention, the temperature drop amount of the heated hot water or the heating temperature of the hot water does not necessarily have to be obtained by arithmetic processing. For example, the main control unit 4 is provided with a data table in which data of the temperature drop amount or hot water heating temperature data corresponding to various boiling operation conditions is stored, and the temperature drop of the hot water is referred to by referring to this data table. The amount or the heating temperature of hot water may be determined.

  In the embodiment described above, the control means (main control unit 4) calculates the required boiling time for the hot water in the hot water storage tank, but it is not limited to this. In the present invention, the user may set the required boiling time by operating a switch or the like. The boiling time required and the boiling target temperature data may be either those obtained by calculation by the control means or those input and set by a switch operation or the like from the outside.

  The heating means is not limited to a heat pump using electric power as a power source, and other various heating means such as those using a gas engine as a power source can be used. Moreover, although the hot water storage tank thermal storage apparatus which concerns on this invention can use the hot water stored by the hot water storage tank by boiling operation for hot water supply, a heating use, etc., the specific use is not ask | required.

It is a schematic explanatory drawing which shows one Embodiment of the hot water storage tank thermal storage apparatus which concerns on this invention. It is a flowchart which shows an example of the operation | movement procedure of the main control part of the hot water storage tank thermal storage apparatus shown in FIG. It is explanatory drawing which shows the change of the heating temperature with respect to the hot water controlled by the operation | movement procedure of the flowchart shown in FIG. It is explanatory drawing which shows the other example of the change of the heating temperature with respect to hot water. It is explanatory drawing which shows the other example of the change of the heating temperature with respect to hot water. It is a schematic explanatory drawing which shows other embodiment of the hot water storage tank thermal storage apparatus which concerns on this invention. It is a schematic explanatory drawing which shows an example of a prior art. (A) is explanatory drawing which shows the preferable storage state of heated hot water, (b) is explanatory drawing which shows the unpreferable storage state of heated hot water.

Explanation of symbols

A, Aa Hot water storage tank thermal storage device Ta Boiling target temperature Tx Heating temperature ΔT1, ΔT2 Temperature drop 1,1A, 1B Hot water storage tank 2 Circulation path 3 Heat pump (heating means)
4 Main control unit (control means)

Claims (5)

A hot water storage tank,
A circulation path for removing hot water from the hot water storage tank and returning it to the hot water storage tank;
Heating means for heating the hot water flowing through the circulation path;
Heating of hot water by the heating means so that a boiling operation for performing heat storage in the hot water storage tank is executed based on the data of the target boiling temperature and the required boiling time for the hot water in the hot water storage tank Control means for performing control;
A hot water storage tank heat storage device comprising:
When the boiling operation is performed, the control means obtains a temperature drop amount from the time of heating the hot water heated by the heating means to the end of the boiling operation at a constant or indefinite period, and this temperature A hot water storage tank heat storage device characterized in that heating temperature change control is performed so that hot water is heated at a temperature obtained by adding a temperature corresponding to the amount of drop to the boiling target temperature.   The control means, when obtaining the temperature drop amount, the remaining time from the time of heating the hot water to the scheduled end time of the boiling operation, the heat dissipation coefficient of the hot water storage tank, and the boiling target temperature and the hot water storage tank A temperature drop amount of hot water in the hot water storage tank is obtained based on data of a difference from the external temperature, and this value is included in the temperature drop amount from the time of heating the hot water to the end of the boiling operation. The hot water storage tank heat storage device according to claim 1, wherein   The control means is configured to further obtain a temperature drop amount of hot water in the circulation path and include this value in a temperature drop amount from the time of heating the hot water to the end of the boiling operation. 2. A hot water storage tank heat storage device according to 2.   A plurality of hot water storage tanks are provided as the hot water storage tanks, and the plurality of hot water storage tanks are connected in series so that hot water inside them can be circulated through the circulation path. A hot water storage tank heat storage device according to any one of the above. A hot water storage tank,
A circulation path for removing hot water from the hot water storage tank and returning it to the hot water storage tank;
Heating means for heating the hot water flowing through the circulation path;
Heating of the hot water by the heating means so that a boiling operation for performing heat storage in the hot water storage tank is executed based on the data of the target boiling temperature and the required boiling time for the hot water in the hot water storage tank Control means for performing control;
A hot water storage tank heat storage device comprising:
The control means, at the start of the boiling operation, is a temperature obtained by adding a temperature corresponding to a temperature drop amount of hot water heated at the start of the operation until the end of the boiling operation to the boiling target temperature. The hot water is heated, and thereafter, the heating temperature is controlled so as to bring the hot water heating temperature closer to the boiling target temperature as it approaches the scheduled end time of the boiling operation. A hot water storage tank heat storage device.

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