JP6672982B2 - Hot water storage system - Google Patents

Description

  The present invention relates to a hot-water storage type hot water supply device such as a heat pump hot water supply device.

  The heat pump water heater has a learning ability based on past heat demand, predicts when heat demand will occur in the future and the amount of heat, and generates heat and water with the heat quantity corresponding to the predicted heat demand by operating the heat pump. There is an operation in which the operation of storing the hot water in the hot water storage tank is performed as soon as possible immediately before the generation of heat demand (for example, Patent Document 1). In the related art, unlike the above-described method, there is a method in which hot water corresponding to one day's heat demand is collectively stored in a hot water storage tank by operating a heat pump using nighttime power, for example. However, the former can reduce the heat radiation loss from the hot water storage tank as compared with such a case. Further, the amount of heat of the hot water stored in the hot water storage tank can be made to more accurately correspond to the actual heat demand. Therefore, it is preferable in suppressing the occurrence of excess or insufficient hot water. Further, as the hot water storage tank, it is not necessary to use a hot water tank having a size capable of storing hot water corresponding to the heat demand for one day, and a small hot water storage tank may be used, and the equipment cost can be reduced. . Conventionally, in addition to the heat pump, as the hot and cold water heating means, there is also a device further provided with an auxiliary heat source device, but according to such a configuration, even if the heat storage amount of the heat pump is insufficient, It is possible to prevent shortage of hot water (running out of hot water).

  However, in the conventional heat pump water heater described above, there is still room for improvement as described below.

That is, when performing the hot water storage operation of the heat pump in order to respond to the predicted latest heat demand, the required heat quantity to be refilled into the hot water storage tank based on the predicted heat demand heat quantity and the current heat quantity in the hot water storage tank. That is, it is necessary to determine the amount of hot water to be newly heated by the heat pump. In this case, instead of calculating the total heat amount of the hot water in the hot water storage tank as the heat amount in the hot water storage tank, the heat amount of the hot water that is lower than the hot water supply set temperature is excluded from the hot water in the hot water storage tank, and the hot water that is higher than the hot water supply set temperature is used. There is a method of calculating the calorific value and using the calorific value as the calorie in the hot water storage tank. According to such means, it is possible to supply hot water above the set hot water supply temperature only with the hot water in the hot water storage tank without operating the auxiliary heat source device for the subsequent heat demand.
However, simply adopting such means does not effectively use hot water below the set hot water supply temperature in the hot water storage tank, and may deteriorate energy efficiency. As a specific example, for example, when a hot water storage operation is performed in response to a demand for hot water supply at night, there is no demand for hot water until the next morning, and the heat pump is stopped for a relatively long time. However, in such a situation, if the above-described means are simply employed, hot water having a temperature lower than the set hot water supply temperature remains in the hot water storage tank during the night, and the calorie of the hot water is relatively large. Even in this case, it is left without being used effectively. When such a situation occurs, the temperature of hot water in the hot water storage tank decreases due to heat radiation loss, and energy efficiency deteriorates. Such a problem may occur not only at night but also when the time from the end of the hot-water storage operation of the heat pump to the start of the next hot-water storage operation is considerably long.

JP-A-2015-10773

  The present invention has been conceived under the circumstances described above, and solves the problem that the heat of the hot water in the hot water storage tank is not effectively used and is left for a long time, It is an object of the present invention to provide a hot water supply type hot water supply device capable of improving energy efficiency.

  In order to solve the above problems, the present invention takes the following technical measures.

  The hot water supply type hot water supply device provided by the present invention is an external heat source device capable of storing hot water in a hot water storage tank and an external heat source device, and hot water supplied from the hot water storage tank to a predetermined tap hole or a heat load in the middle thereof. An auxiliary heat source unit that can be heated, and a heat quantity of a future heat demand based on past hot water supply operation results, and the predicted heat quantity of the heat demand and the hot water stored in the hot water storage tank. A control unit capable of executing a process for determining a required amount of heat to be refilled in the hot water storage tank until the most recent heat demand is generated based on the heat amount and the hot water storage type hot water supply device. In the case of normal hot water storage operation, the amount of heat in the tank does not include the amount of hot water below the predetermined reference temperature, which is equal to or higher than the hot water supply set temperature, of the hot water in the hot water storage tank, and Calorie On the other hand, in the case of the first specific hot-water storage operation as the last hot-water storage operation on the day, or the second specific hot-water storage operation having a predetermined time interval or more from the end of the current hot-water storage operation to the start of the next hot-water storage operation Is characterized in that the heat amount includes the heat amount of the hot and cold water below the reference temperature.

According to such a configuration, the following effects can be obtained.
First, when the above-described first or second specific hot water storage operation is performed, for the subsequent heat demand, in the hot water storage tank, the temperature does not reach the reference temperature, and the hot water can be directly used for hot water supply. Hot water that cannot be used is also effectively used for hot water supply (the hot water temperature can be raised to the hot water supply temperature by operating the auxiliary heat source device). For this reason, if a large amount of hot water below the reference temperature remains in the hot water storage tank and this hot water is carried over from the day to the next day, or if the time interval of the hot water storage operation of the heat pump is long, the hot water below the reference temperature during that period It is eliminated that a large amount of the particles are left.
On the other hand, when the normal hot water storage operation is performed, the subsequent heat demand can be covered only by hot water having a predetermined reference temperature or higher. Therefore, it is not necessary to operate the auxiliary heat source device.
For this reason, it is possible to make the hot water supply type hot water supply apparatus high in energy efficiency and excellent in energy saving and economic efficiency.

  In the present invention, preferably, in the case of the first or second specific hot water storage operation, the amount of heat in the hot water storage tank is set to the total amount of hot water in the hot water storage tank.

  According to such a configuration, when heat demand occurs after the first or second specific hot water storage operation is performed, it becomes more preferable in increasing the utilization efficiency of the remaining hot water in the hot water storage tank.

  In the present invention, preferably, the heat amount in the hot water storage tank is obtained based on a temperature of the hot water in the hot water storage tank and the amount thereof, and as a value of the temperature of the hot water, the water input temperature to the hot water storage tank or the water temperature. The value of the difference between the incoming water temperature to the external heat source device and the actual temperature of the hot water in the hot water storage tank is used.

  According to such a configuration, in addition to facilitating the arithmetic processing for calculating the heat quantity in the hot water storage tank, the heat quantity in the hot water storage tank may reflect the temperature of incoming water to the hot water storage tank or the temperature of incoming water to the external heat source device. it can.

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

BRIEF DESCRIPTION OF THE DRAWINGS It is a schematic explanatory drawing which shows an example of the hot-water storage type hot-water supply apparatus which concerns on this invention. It is a flowchart which shows an example of the basic operation procedure performed by the control part of the hot-water storage type hot water supply apparatus shown in FIG. (A), (b) is a time chart which shows an example of the relationship between heat demand and hot-water storage driving | operation. It is a flowchart which shows the example of the data processing performed by the control part of the hot-water storage type hot water supply apparatus shown in FIG.

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

  A hot water supply type hot water supply apparatus A shown in FIG. 1 is a heat pump hot water supply apparatus, and is configured by combining a heat pump 1 as an external heat source device and a hot water storage tank unit U. Since the hardware configuration of each of these components is the same as that of the heat pump hot water supply device described in Patent Document 1, the description thereof will be made simply.

The heat pump 1 includes, for example, an evaporator 10 that absorbs heat from air taken in using a fan 10a in a circulation path of a refrigerant such as CO ₂ , a compressor 11, a heat exchanger 12 for hot and cold water as a condenser, And an expansion valve 13.

  Hot water storage tank unit U includes hot water storage tank 2, auxiliary heat source unit 3, and control unit 4. A plurality of temperature sensors Sa for detecting the temperature of hot and cold water stored inside the hot water storage tank 2 are attached. The lower part and the upper part of the hot water storage tank 2 are connected to the heat exchanger 12 of the heat pump 1 via the return pipes 50a and 50b, and are driven up by the heat pump 1 by driving the circulation pump P1 of the transfer pipe 50a. Hot water storage operation for storing hot water in the hot water storage tank 2 is possible. In this hot water storage operation, the hot water flows through the routes indicated by arrows N11 to N13, the hot water flowing out from the lower part of the hot water storage tank 2 is heated by the heat exchanger 12, and then returned to the upper part in the hot water storage tank 2.

  A water inlet pipe 61 having a water inlet 61a and a water outlet pipe 62 having a water outlet 62a are connected to a lower part and an upper part of the hot water storage tank 2, respectively. When the hot-water tap 90 connected to the hot-water outlet 62a is opened, the hot water in the hot-water storage tank 2 flows out to the hot-water outlet pipe 62 by the pressure of water input into the hot-water storage tank 2, and the hot water is supplied from the hot-water outlet 62a to the hot water tap 90. Supplied to.

  The auxiliary heat source unit 3 is used for heating hot water when the amount of hot water in the hot water storage tank 2 is insufficient, for example, and has a configuration similar to that of the instantaneous gas water heater, for example, with the burner 30 and the hot water heater. The heat exchanger 31 is housed in the can 32, and the hot water supplied to the heat exchanger 31 can be quickly heated by the burner 30. The water inlet side pipe part 70a of the auxiliary heat source unit 3 is connected to the upper part of the hot water storage tank 2 via the pump P2 and the three-way valve V1. The tapping-side pipe portion 70b of the auxiliary heat source unit 3 is connected to the tapping pipe 62 via the three-way valve V2. For this reason, when hot water is supplied from hot water outlet 62a toward hot water tap 90, three-way valve V2 is switched to discharge hot water heated by auxiliary heat source device 3 as shown by arrows N21 and N22. Can be supplied.

A heat exchanger 92 is provided in a pipe section 71 branched and connected to the tapping-side pipe section 70b of the auxiliary heat source unit 3. The heat exchanger 92 is one of the heat loads, and is for heating a heating medium for a heating terminal 91 such as a floor heating device. The heat medium can be circulated and circulated between the heat exchanger 92 and the heating terminal 91 by driving the pump P3. The three-way valves V1 and V3 are connected via a pipe portion 63, and the hot water that has passed through the heat exchanger 92 and reached the three-way valve V3 is sent again to the auxiliary heat source unit 3 without passing through the hot water storage tank 2. Can be heated.

  The control unit 4 corresponds to an example of a control unit according to the present invention, and is configured using a microcomputer or the like. The control section 4 executes operation control and data processing of each section of the hot water storage tank unit U, and also executes overall operation control of the hot water storage type hot water supply apparatus A in cooperation with a control section (not shown) of the heat pump 1. . A remote controller 8 is communicatively connected to the control unit 4. The remote controller 8 has a data display section 80 and a plurality of operation switches 81. By operating these operation switches 81, for example, setting of hot water supply temperature, operation start time of the heating terminal 91, and the like can be performed. It is possible.

The control unit 4 can execute operation control as shown in the flowchart of FIG.
That is, the control unit 4 predicts the heat demand within a predetermined period from the current time (S1). The control unit 4 has a learning ability for estimating, for example, heat demand in the next nine hours based on past heat demand (hot water supply operation results), various hot water supply reservation settings using the remote controller 8, and the like. Based on this capacity, the above-mentioned heat demand is predicted. Prediction of heat demand is, specifically, a process of predicting a heat demand generation time zone and the amount of heat of the heat demand in that time zone. The heat demand generation time zone is, for example, from 17:00 to 18:00, It is divided every hour, such as from 18:00 to 19:00.

When the heat demand is predicted, a process of calculating the required heat quantity Qn to be refilled into the hot water storage tank 2 until the heat demand is generated is also executed (S2). Although the details of this processing will be described later, the required heat quantity Qn is obtained by the following equation 1.
Qn = Q1-Q2 Equation 1
Q1: Predicted calorific value of heat demand Q2: Current calorie in hot water storage tank

  After calculating the required heat quantity Qn, the control unit 4 determines the required time for boiling the hot water with the required heat quantity Qn by the heat pump 1 and the like, and determines the storage operation start time of the heat pump 1 (S3). Thereafter, when this time comes, the storage operation of the heat pump 1 is started, and the hot water with the required heat quantity Qn is heated (S4: YES, S5).

  Next, the operation of the above-mentioned hot water supply type hot water supply apparatus A, in particular, the processing for obtaining the required amount of heat Qn will be described with reference to the time chart shown in FIG. 3 and the flowchart shown in FIG.

  The required heat quantity Qn is finally obtained by calculating Qn = Q1-Q2 in the above-described equation 1 as shown in step S13 of FIG. 4, but in the present embodiment, the hot-water storage operation of the heat pump 1 is performed. It is determined whether or not it is the last hot water storage operation on the day (S11), and the value of the heat amount Q2 in the hot water storage tank is changed according to the determination result. Here, "the day" does not necessarily have to be in the range from 0:00 to 24:00. For example, as shown in FIG. 3, the start and end of the current day (one day) can be shifted, such that the start is at 3:00 and the end is 24 hours later. In FIG. 3A, heat demands D1 to D3 of the first to third groups are generated, and as shown in FIG. 3B, corresponding hot water storage operation periods P1 to P3 are provided. I have. In the figure, the hot-water storage operation in the period P3 corresponds to the last hot-water storage operation on the day, and the hot-water storage operation in the periods P1 and P2 does not correspond thereto.

  In the case where the hot water storage operation of the heat pump 1 is a normal hot water storage operation that is not the last hot water storage operation on the day, of the hot water in the hot water storage tank 2, the heat amount of the hot water having a temperature lower than the predetermined reference temperature T <b> 1 is not considered. The calorific value of the hot water at or above the temperature T1 is calculated, and this calorie is set as the calorific value Q2 in the hot water storage tank (S11: NO, S14). The amount of heat of the hot water below the reference temperature T1 is not included in the amount of heat Q2 in the hot water storage tank. The reference temperature T1 is a temperature equal to or higher than the hot water supply set temperature T0 (target hot water supply temperature) set using the remote controller 8 or the like, and is, for example, a temperature obtained by adding a fixed value to the hot water supply set temperature T0. The fixed value is, for example, 1 ° C. In this case, if the hot water supply set temperature T0 is 40 ° C., the reference temperature T1 is 41 ° C. However, it goes without saying that the specific value of the reference temperature T1 is not limited to this.

As described above, the heat quantity Q2 in the hot water storage tank is set to the heat quantity of the hot water above the reference temperature T1, and the heat quantity of the hot water is determined by the quantity of the hot water above the reference temperature T1 and the specific hot water temperature T2. It can be calculated based on this. The amount of hot water above the reference temperature T1 is determined from the total capacity of the hot water storage tank 2 based on the number or position of the temperature sensors Sa at which the temperature above the reference temperature T1 is detected among the plurality of temperature sensors Sa. It is possible.
On the other hand, in the present embodiment, as the hot water temperature T2, the value of the difference between the incoming water temperature T3 into the hot water storage tank 2 and the actual temperature T2 'of the hot water in the hot water storage tank 2 is used. The incoming water temperature T3 is detected, for example, using a temperature sensor Sb attached to the inlet pipe 61 shown in FIG. 1, and the actual temperature T2 'is a temperature detected using a plurality of temperature sensors Sa. As a specific example, when the incoming water temperature T3 is 10 ° C. and the actual temperature T2 ′ is 60 ° C., a value of 50 ° C. is used as the hot and cold water temperature T2. If such a method is used, the arithmetic processing becomes easy, and the heat quantity Q2 in the hot water storage tank reflects the incoming water temperature T3. In addition, it is also possible to use the water inlet temperature to the heat pump 1 instead of the water inlet temperature T3, and this water inlet temperature can be detected using, for example, a temperature sensor Sc attached to the going pipe 50a shown in FIG. it can.
After calculating the amount of heat Q2 in the hot water storage tank, as described above, Qn = Q1-Q2 is calculated to obtain the required amount of heat Qn (S13).

  In the normal hot water storage operation, when the hot water having the required heat quantity Qn obtained as described above is refilled into the hot water storage tank 2, when the heat demand is generated thereafter, only the hot water having the reference temperature T1 or higher is supplied. Hot water can be supplied from the hot water storage tank 2 to cover the heat demand. This eliminates the need to operate the auxiliary heat source unit 3 and improves energy efficiency.

  On the other hand, unlike the above, when the hot-water storage operation of the heat pump 1 is the last hot-water storage operation on the day, the heat amount of the entire amount of hot water in the hot water storage tank 2 is calculated, and this heat amount is set as the heat amount Q2 in the hot-water storage tank. (S11: YES, S13). The amount of heat of the hot water below the reference temperature T1 is also included in the amount of heat Q2 in the hot water storage tank. Also in this case, as in the case described above, when calculating the heat quantity Q2 in the hot water storage tank, the hot water temperature T2 in the hot water storage tank 2 is used as the hot water temperature T3 in the hot water storage tank 2 (or the hot water temperature in the heat pump 1). ) And the actual temperature T2 ′ of the hot water in the hot water storage tank 2 is used. The amount of heat Q2 in the hot water storage tank is obtained by Qn = Q1-Q2 as in the case of the normal hot water storage operation (S13).

  In the last hot water storage operation of the day, if the hot water having the required heat quantity Qn obtained as described above is refilled in the hot water storage tank 2, when the heat demand is generated thereafter, the hot water less than the reference temperature T1 is also stored in the hot water storage tank. The hot water is discharged from 2 and can be used effectively. For this reason, it is avoided that the hot water is carried over to the next morning until the next morning, while a large amount of hot water having a temperature lower than the reference temperature T1 remains in the hot water storage tank 2, thereby causing a temperature drop due to heat radiation. Therefore, energy efficiency can be improved. When hot water having a temperature lower than the reference temperature T1 flows out of the hot water storage tank 2, the hot water is heated using the auxiliary heat source unit 3. Therefore, it is possible to appropriately supply hot water at the hot water supply set temperature to the hot water supply destination.

  Although not shown in the flowchart of FIG. 4, in the present invention, the same processing as step S <b> 12 executed in the case of the last hot water storage operation (first specific hot water storage operation) on the day is performed at the end of the current hot water storage operation. The present invention can also be applied to a case of a hot-water storage operation (second specific hot-water storage operation) in which there is a predetermined time interval or more before the next hot-water storage operation starts. If the period from the end of the current hot water storage operation to the next hot water storage operation is long, as in the case of the last hot water storage operation on the day, the water remaining in the hot water storage tank 2 having a temperature lower than the reference temperature T1 is relatively long. There is a possibility that a large amount of energy loss due to heat radiation occurs due to being left for a long time. By applying the same processing as in step S12, such a fear can be appropriately eliminated.

  The present invention is not limited to the contents of the above-described embodiment. The specific configuration of each part of the hot water supply type hot water supply apparatus according to the present invention can be variously modified within the range intended by the present invention.

  In step S12 of FIG. 4, the heat amount of the entire amount of hot water in the hot water storage tank 2 is set to the heat amount Q2 in the hot water storage tank, but is not necessarily limited to this. For example, in the case where there is a part of a very low temperature water below a predetermined temperature, the heat amount Q2 in the hot water storage tank may be obtained in such a manner that the heat amount of the water is ignored.

  As the external heat source device, a device other than the heat pump can be used. The auxiliary heat source unit is not limited to the gas combustion type, but may be an oil combustion type or an electric heater.

A Hot water storage type hot water supply device Qn Required heat quantity Q1 Heat quantity of heat demand Q2 Heat quantity in hot water storage tank 1 Heat pump 2 Hot water storage tank 3 Auxiliary heat source unit 4 Control unit (control means)

Claims (3)

An external heat source device capable of storing hot water in a hot water storage tank,
An auxiliary heat source device capable of heating hot water sent from the hot water storage tank to a predetermined tap hole or heat load on the way,
The heat quantity of the future heat demand is predicted based on the past hot water supply operation results, and the latest heat demand is calculated based on the predicted heat demand heat quantity and the heat quantity in the hot water storage tank stored in the hot water storage tank. Control means capable of executing a process of determining a required amount of heat to be replenished to the hot water storage tank until the heat generation occurs,
A hot water supply type hot water supply device comprising:
The amount of heat in the hot water storage tank is
In the case of the normal hot water storage operation, the hot water in the hot water storage tank does not include the heat amount of the hot water that is lower than the predetermined reference temperature that is equal to or higher than the hot water supply set temperature, and is set to the heat amount of the hot water that is equal to or higher than the reference temperature. ,
In the case of the first specific hot-water storage operation as the last hot-water storage operation on the day, or the second specific hot-water storage operation having a predetermined time interval or more from the end of the current hot-water storage operation to the start of the next hot-water storage operation, A hot-water storage type hot water supply device characterized in that the amount of heat includes the amount of hot water below the reference temperature. It is a hot-water storage type hot-water supply device according to claim 1,
In the case of the first or second specific hot water storage operation, the heat quantity in the hot water storage tank is the heat quantity of the entire amount of hot water in the hot water storage tank. The hot water storage type hot water supply device according to claim 1 or 2,
The amount of heat in the hot water storage tank is obtained based on the temperature of the hot water in the hot water storage tank and the amount thereof, and the value of the temperature of the hot water is a water input temperature to the hot water storage tank or a water input temperature to the external heat source device. And a value of a difference between the actual temperature of the hot water in the hot water storage tank and the actual temperature of the hot water in the hot water storage tank.

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