JP7514422B2 - Storage tank type hot water supply device - Google Patents

Description

The present invention relates to a hot water supply device equipped with a hot water storage tank.

The present applicant has previously proposed specific examples of storage type hot water supply devices as described in Patent Documents 1 and 2.
The hot water storage type hot water supply devices described in these documents include a hot water storage tank that stores hot water heated using a main heat source and can be used to fill a bathtub or to supply hot water for other general hot water supply purposes, and an auxiliary heat source unit. The auxiliary heat source unit can heat hot water supplied through a flow path that does not pass through the hot water storage tank, or hot water that is supplied from the hot water storage tank, when there is a temperature shortage, for example, when the temperature of the hot water in the hot water storage tank is lower than the target temperature for filling the bathtub. With this configuration, it is possible to appropriately resolve the difficulty in supplying hot water at the desired temperature when the hot water storage tank runs out of hot water.

Here, in Patent Document 1, the hot water discharged from the hot water storage tank is configured to be heated by the auxiliary heat source unit. In contrast, in Patent Document 2, there is no means (corresponding to the piping 68 and valve V3 shown by the phantom lines in FIG. 1 described later) for sending the hot water in the hot water storage tank to the auxiliary heat source unit, and the hot water discharged from the hot water storage tank cannot be heated by the auxiliary heat source unit. In Patent Document 2, when the hot water in the hot water storage tank is insufficient in temperature, hot water is supplied from the outside to the auxiliary heat source unit and this hot water is heated. With this configuration in Patent Document 2, no piping is required to send the hot water in the hot water storage tank to the auxiliary heat source unit, making it possible to simplify the overall device configuration and reduce manufacturing costs.

However, the configuration described in Patent Document 2 above had the following problems.

That is, in Patent Document 2, if the temperature of the hot water in the hot water storage tank is insufficient, the hot water in the hot water storage tank is not used for hot water supply and is not discharged, so the frequency of replacing the hot water in the hot water storage tank is lower than in Patent Document 1, for example, and the hot water is likely to remain in the hot water storage tank for a long time. If the retention time becomes too long, there is a risk that bacteria such as Legionella bacteria will grow, resulting in unsanitary conditions.
On the other hand, in the past, when the retention time of hot water in the hot water storage tank reaches a predetermined retention limit time, the hot water in the hot water storage tank is sent to the main heat source to be heated and sterilized. By adopting such a means, the above-mentioned problems can be appropriately solved, but in Patent Document 2, the frequency with which the retention time reaches the predetermined retention limit time, and therefore the frequency with which the hot water needs to be sterilized, increases. This is not only disadvantageous in terms of energy conservation, but also causes inconvenience because the hot water in the hot water storage tank cannot be used for hot water supply during sterilization.

JP 2014-25681 A JP 2014-9894 A Patent No. 6252762 Patent No. 4981777

The present invention was conceived in light of the above-mentioned circumstances, and aims to provide a hot water storage type water heater that can adequately solve the problem of hot water staying in the hot water storage tank for a long time, resulting in unsanitary conditions, through a simple configuration.

To solve the above problems, the present invention provides the following technical solutions:

The hot water storage type hot water supply device provided by the present invention is a hot water storage tank that stores hot water heated using a main heat source and can be supplied for filling the bathtub, and an auxiliary heat source unit that, when filling the bathtub, heats hot water supplied from outside without passing through the hot water storage tank if the hot water in the hot water storage tank is not hot enough, and can supply hot water for filling the bathtub.The hot water storage type hot water supply device is characterized in that, when the retention time of at least a portion of the hot water in the hot water storage tank exceeds a predetermined time, a predetermined amount of hot water in the hot water storage tank is supplied to the bathtub when filling the bathtub, regardless of whether the hot water in the hot water storage tank is not hot enough.

According to this configuration, the following effects can be obtained.
In other words, when the retention time of at least a portion of the hot water in the hot water storage tank exceeds a predetermined time, regardless of whether the temperature of the hot water in the hot water storage tank is insufficient or not, a predetermined amount of hot water in the hot water storage tank is supplied to the bathtub, which promotes replacement of the hot water in the hot water storage tank and makes it possible to prevent hot water from remaining in the hot water storage tank for a long time. This makes it possible to prevent the proliferation of bacteria such as Legionella bacteria and to ensure sanitary conditions.
In the case where a means for heating and sterilizing the hot water in the hot water storage tank is adopted when the hot water retention time in the hot water storage tank becomes long, the frequency of the sterilization process is reduced according to the present invention, which makes it possible to save energy. In addition, the inconvenience of being unable to use the hot water in the hot water storage tank during the sterilization process is eliminated or alleviated.

In the present invention, preferably, when the bathtub is filled with hot water, if the temperature of the hot water in the hot water storage tank is insufficient, the hot water coming out of the hot water storage tank and the hot water heated by the auxiliary heat source unit are mixed and supplied to the bathtub.

According to this configuration, the following effects can be obtained.
In other words, if the temperature of the hot water in the hot water storage tank is insufficient, for example, if only the hot water in the hot water storage tank is used to fill the bathtub, the temperature of the hot water in the bathtub may be significantly lower. In contrast, with the above-mentioned configuration, the temperature of the hot water in the bathtub can be made higher than the temperature of the hot water in the hot water storage tank, eliminating the above-mentioned risk.

In the present invention, preferably, when the bathtub is filled with hot water, if the temperature of the hot water in the hot water storage tank is insufficient, hot water heated by the auxiliary heat source device is further supplied to the bathtub, or the hot water in the bathtub is reheated, so that the hot water in the bathtub is set to a predetermined target temperature for filling the bathtub.

With this configuration, even if the hot water in the hot water storage tank is not hot enough and this water is used to fill the bathtub, the water in the bathtub can ultimately be appropriately set to a predetermined target temperature for filling the bathtub.

In the present invention, it is preferable that when the residence time of at least a portion of the hot water in the hot water storage tank exceeds the predetermined time, the amount of stagnant hot water whose residence time exceeds the predetermined time is determined, and an amount equal to or greater than this amount of stagnant hot water is set to the predetermined amount.

With this configuration, all or more than all of the hot water in the hot water storage tank that has a retention time that exceeds a predetermined time is supplied to the bathtub when it is filled. Therefore, when filling the bathtub with water is complete, no hot water that has a retention time that exceeds the predetermined time remains in the hot water storage tank.

In the present invention, preferably, when the retention time of at least a portion of the hot water in the hot water storage tank exceeds the predetermined time, the amount of the retained hot water whose retention time exceeds the predetermined time is calculated, and when it is planned or predicted that the bathtub will be filled multiple times during the period from the present time to the predetermined retention limit time, an amount of hot water equal to or greater than the amount of retained hot water is supplied from the hot water storage tank to the bathtub in a divided state for each of the multiple bathtub filling operations.

With this configuration, hot water in the hot water storage tank that has a retention time exceeding a predetermined time is supplied to the bathtub in small portions for each of the multiple bathtub filling operations under specified conditions, making it possible to avoid supplying a large amount of hot water that is insufficient in temperature in the hot water storage tank to the bathtub all at once. This reduces the risk of the temperature of the hot water filling the bathtub becoming significantly low, and makes it possible to standardize the conditions when the bathtub is filled multiple times (for example, standardizing the so-called bath heating time).

In the present invention, preferably, the device further includes a means for setting a hot water/water replacement promotion mode for promoting the replacement of hot water/water in the hot water storage tank, and when the hot water/water replacement promotion mode is set, when the bathtub is filled with water, at least a portion of the hot water/water in the hot water storage tank is supplied to the bathtub, regardless of whether the residence time of at least a portion of the hot water in the hot water storage tank exceeds the predetermined time or whether the hot water in the hot water storage tank is insufficient in temperature.

With this configuration, when the hot water/cold water replacement promotion mode is set, the replacement of hot water/cold water in the hot water storage tank is further promoted, making it possible to accurately respond to the needs of users who request such a thing.

Other features and advantages of the present invention will become more apparent from the following detailed description of the preferred embodiment of the invention, taken in conjunction with the accompanying drawings.

1 is a schematic explanatory diagram showing an example of a hot water storage type hot water supply device according to the present invention. 4 is a flowchart showing an example of an operational processing procedure executed by the storage type hot water supply device shown in FIG. 1 . 10 is a flowchart showing another example of the operational processing procedure executed in the storage type hot water supply device shown in FIG. 1 . 10 is a flowchart showing another example of the operational processing procedure executed in the storage type hot water supply device shown in FIG. 1 .

The preferred embodiment of the present invention will be described in detail below with reference to the drawings.

The hot water storage type hot water supply device A shown in FIG. 1 includes a heat pump unit U1 and a hot water storage tank unit U2.
2 is combined to form a heat pump hot water supply device.

The heat pump unit U1 corresponds to an example of the main heat source of the present invention, and includes a heat pump 1 and a control unit (not shown) for controlling the heat pump 1. The heat pump 1 is similar to a conventionally known one, and includes an evaporator ₁₀ that absorbs heat from air taken in by a fan 10a, a compressor 11, a condensing heat exchanger 12 (condenser) for heating hot water, and an expansion valve 13 in a circulation path of a refrigerant such as CO2.

The hot water storage tank unit U2 includes a hot water storage tank 2, an auxiliary heat source unit 3, and a control unit 4.

The lower and upper parts of the hot water storage tank 2 are connected (piped connection) to the condensing heat exchanger 12 of the heat pump 1 via the hot water forward flow path 5a and the hot water return flow path 5b. When the circulation pump P1 provided in the hot water forward flow path 5a is driven, hot water flowing out from the lower part of the hot water storage tank 2 to the hot water forward flow path 5a is sent to the condensing heat exchanger 12 and heated, and this heated hot water is returned to the upper part of the hot water storage tank 2 via the hot water return flow path 5b and stored. The hot water storage tank 2 is equipped with multiple temperature sensors Sa, and the control unit 4 can determine the amount of hot water (heat storage amount) stored in the hot water storage tank 2 based on the detection signals from these temperature sensors Sa.

A water inlet pipe 61 with a water inlet 61a and a hot water outlet pipe 62 with a hot water outlet 62a are separately connected to the bottom and top of the hot water storage tank 2. When the hot water tap 90 connected to the hot water outlet 62a is opened, hot water in the hot water storage tank 2 flows out to the hot water outlet pipe 62, and is supplied to the hot water tap 90 (general hot water supply).

In the hot water storage tank unit U2, in addition to the general hot water supply described above, it is also possible to fill the bathtub 91 with water, reheat the bath, and perform heating operations by supplying hot water (heat medium) to the heating terminal 92.Furthermore, if the temperature of the hot water in the hot water storage tank 2 is insufficient, it is possible to use the auxiliary heat source unit 3 to make up for the lack of heat.
Specifically, the hot water storage tank unit U2 is provided with a flow path 63 that guides hot water discharged from the hot water storage tank 2 to the bathtub 91, and an on-off valve V1, and by opening this on-off valve V1, it is possible to supply hot water (fill the bathtub 91). In addition, it is further provided with a circulation pump P2 and heat exchanger 8a that enable bath reheating, a heat medium circulation flow path 64 and heat exchanger 8b having a circulation pump P3 for the heating terminal 92, and various hot water flow paths, valves, pumps, etc. associated with these.

The auxiliary heat source unit 3 is similar to, for example, a gas instantaneous water heater, and is configured such that the burner 30 and heat exchanger 31 are housed in the tank body 32, and hot water supplied to the heat exchanger 31 via the pump P4 can be quickly heated by the burner 30. In this hot water storage tank unit U2, there is no means (means corresponding to the piping 68 and valve V3 shown in phantom lines) capable of directing hot water discharged from the hot water storage tank 2 to the auxiliary heat source unit 3. The auxiliary heat source unit 3 is capable of hot water supply operation in which hot water that enters the water inlet 61a and flows into the auxiliary heat source unit 3 without passing through the hot water storage tank 2 is heated, and the heated hot water is discharged from the water outlet 62a.

The control unit 4 is configured using a microcomputer, etc., and controls the operation of each part of the hot water storage tank unit U2 and processes data, but as described below, it also performs control to ensure that the retention time of hot water in the hot water storage tank 2 does not exceed a predetermined retention limit time.

A remote control 40 is communicatively connected to the control unit 4. The remote control 40 has a data display unit 41 and a number of operation switches 42, and by operating the operation switches 42, for example, it is possible to set a hot water/cold water replacement promotion mode, which will be described later. The control unit 4 has a learning capability to predict future heat demand based on past heat demand (hot water supply operation results), and can automatically start filling the bathtub 91 with water at an appropriate time.

Next, the operational processing procedure executed in the above-mentioned hot water storage type hot water supply device A will be explained with reference to the flowchart shown in FIG. 2. The action at that time will also be explained.

First, the control unit 4 periodically determines the retention time of hot water (oldest hot water) in the hot water storage tank 2 (S1). The retention time of hot water can be calculated from information such as the volume of the hot water storage tank 2, the amount of hot water discharged from the hot water storage tank 2, the time of discharge (the same as the time when water enters the hot water storage tank 2 from the bottom), and the current time. After the retention time of the hot water is determined, it is compared with a predetermined time Ta (S2). This predetermined time Ta is shorter than a predetermined retention limit time, but this retention limit time is a time that is considered undesirable from a hygienic standpoint if hot water remains in the hot water storage tank 2 for a longer period of time than this, as there is a risk of bacteria such as Legionella bacteria proliferating.

If the result of the above comparison shows that the retention time of the hot water does not exceed the predetermined time Ta, no special control is performed. That is, in this case, when the bathtub 91 is subsequently filled with water, normal control is performed, and if the temperature of the hot water in the hot water storage tank 2 is insufficient relative to the target filling temperature, hot water heated using the auxiliary heat source unit 3 is supplied to the bathtub 91 (S2: NO, S9: YES, S10: YES, S11). In contrast, if the temperature of the hot water in the hot water storage tank 2 is not insufficient, the hot water in the hot water storage tank 2 is supplied to the bathtub 91 and the bathtub is filled with water (S10: NO, S12).

On the other hand, if the retention time of the hot water exceeds the predetermined time Ta, the following process is carried out when filling the bathtub 91 with hot water begins (S2: YES, S3: YES).
First, before actually starting to fill the bathtub 91 with hot water, the amount Q of hot water (stagnant hot water) that has exceeded the predetermined time Ta in the hot water storage tank 2 is calculated (S4). This amount Q can be calculated based on the volume of the hot water storage tank 2 and the amount of hot water dispensed from the hot water storage tank 2.

Next, regardless of whether the temperature of the hot water in the hot water storage tank 2 is insufficient relative to the target filling temperature, an amount of hot water equal to or greater than the amount of retained hot water Q is discharged from the hot water storage tank 2 (S5). As a result, the entire amount of hot water whose retention time exceeds the predetermined time Ta is discharged from the hot water storage tank 2, making it possible to maintain an appropriate sanitary condition within the hot water storage tank 2.
In this storage type hot water supply device A, when the retention time of the hot water in the hot water storage tank 2 reaches the above-mentioned retention limit time, it is possible to apply a means for heating the hot water in the hot water storage tank 2 using the heat pump unit U1 and sterilizing it.In this case, according to this embodiment, it is possible to reduce the frequency of the sterilization process, and it is possible to reduce running costs.

In step S5 described above, preferably, when hot water is dispensed from the hot water storage tank 2, the hot water heated using the auxiliary heat source unit 3 is mixed. This makes it possible to supply hot water at or near the target filling temperature to the bathtub 91 even if the temperature of the hot water in the hot water storage tank 2 is low. This is advantageous in that it eliminates the need for reheating the water in the bathtub 91 to bring it to the specified target filling temperature after filling, or in that it shortens the reheating time.

After filling (pouring) the bathtub 91 with water is completed, the temperature of the water in the bathtub 91 is checked, and if it is below the target filling temperature, the temperature of the water in the bathtub is set to the target filling temperature by supplying high-temperature water heated by reheating or using the auxiliary heat source unit 3 to the bathtub 91 (S6: YES, S7, S8).

This storage-type hot water supply device A can be configured to further execute operational control as shown in Figures 3 and 4.

In the flowchart shown in FIG. 3, steps S1 to S4 are the same as those in FIG. 2. In the operational control shown in FIG. 3, when the retention time of hot water in the hot water storage tank 2 exceeds the predetermined time Ta, the number of times the bathtub 91 will be filled from the current time until the predetermined retention time limit is reached is determined (S21). This determination is made based on the learning function of the control unit 4, or reservation information for filling the bathtub 91 with hot water set using the remote control 40. If the result of this determination is that the bathtub 91 will be filled with hot water only once, control similar to that from step S5 onwards in FIG. 2 is executed (S22: NO).

In contrast, if the bathtub 91 is filled multiple times, the amount of hot water dispensed from the hot water storage tank 2 to the bathtub 91 when filling the bathtub 91 is the amount Q of the stagnant hot water calculated in step S4 divided into multiple portions (S22: YES, S23). Of course, the dispense of hot water from the hot water storage tank 2 is performed regardless of whether the temperature of the hot water in the hot water storage tank 2 is insufficient relative to the target filling temperature.

This type of operational control makes it possible to prevent a large amount of insufficient hot water from being supplied to the bathtub 91 from the hot water storage tank 2 when the bathtub 91 is filled with water at one time. This makes it possible to prevent the temperature of the hot water filled in the bathtub 91 from becoming significantly low. If a large amount of insufficient hot water is supplied to the bathtub 91 at once, there is a risk that it will take a long time to reheat this water and raise the temperature to the target filling temperature, but the above-mentioned operational control makes it possible to eliminate such a risk.

In the operational control shown in FIG. 4, when filling the bathtub 91 with water, the control unit 4 is configured to determine whether the hot water replacement promotion mode is set (S31: YES, S32). Here, the hot water replacement promotion mode is a mode for promoting the replacement of hot water in the hot water storage tank 2, and as described above, it can be set, for example, by operating the remote control 40. If this hot water replacement promotion mode is set, when filling the bathtub 91 with water, at least a portion of the hot water in the hot water storage tank 2 is supplied to the bathtub 91 regardless of whether the residence time of the hot water in the hot water storage tank 2 exceeds the above-mentioned predetermined time Ta and whether the hot water in the hot water storage tank 2 is insufficient in temperature (S32: YES, S33).

When the hot water/cold water replacement promotion mode is set, the replacement of hot water/cold water in the hot water storage tank 2 is further promoted, which is preferable for users who desire this.
On the other hand, unlike the above, when the hot and cold water exchange promotion mode is not set, the operation control already described with reference to FIG. 2 is executed (S32: NO).

The present invention is not limited to the above-described embodiment. The specific configurations of the components of the storage type hot water supply device according to the present invention can be freely designed and modified in various ways within the intended scope of the present invention.
Instead of a heat pump unit, the main heat source may be other devices or equipment, such as a gas engine system or a fuel cell unit equipped with a heat exchanger capable of heating hot and cold water.

A Storage type hot water supply device U1 Heat pump unit (main heat source)
U2 Hot water tank unit 1 Heat pump 2 Hot water tank 3 Auxiliary heat source unit 4 Control unit 40 Remote control (means for setting hot water replacement promotion mode)
91 Bathtub

Claims (6)

A hot water storage tank capable of storing hot water heated by a main heat source and discharging hot water for filling a bathtub;
When the bathtub is being filled with hot water, if the temperature of the hot water in the hot water storage tank is insufficient, an auxiliary heat source device heats hot water supplied from the outside without passing through the hot water storage tank, and enables hot water to be supplied for filling the bathtub;
Equipped with
The upper and lower portions of the hot water storage tank are connected to the main heat source by piping, and the hot water storage operation of the hot water storage tank is performed in such a manner that hot water that has been heated by being sent from the lower portion of the hot water storage tank to the main heat source is returned to the upper portion of the hot water storage tank;
A hot water supply device of a storage type, in which a water inlet pipe and a hot water outlet pipe are separately connected to the lower and upper parts of the hot water storage tank, respectively, and hot water is supplied to the bathtub by supplying water from the water inlet pipe to the lower part of the hot water storage tank, and hot water in the upper part of the hot water storage tank flows out to the hot water outlet pipe ,
The hot water storage tank further includes a control unit capable of determining whether a specific state occurs in which the retention time of at least a portion of the hot water in the hot water storage tank exceeds a predetermined time,
When the control unit determines that the specific state has occurred, a predetermined amount of hot water in the hot water storage tank is supplied to the bathtub when the bathtub is filled with hot water, regardless of whether the temperature of the hot water in the hot water storage tank is insufficient or not; and
This storage-type hot water supply device is characterized in that, when the control unit determines that the specific state has occurred, it further performs a process to determine the amount of stagnant hot water in the hot water storage tank whose retention time exceeds the specified time, and when it is scheduled or predicted that the bathtub will be filled multiple times during the period from the current time to the specified retention limit time, an amount of hot water equal to or greater than the amount of stagnant hot water is supplied from the hot water storage tank to the bathtub in a divided state for each of the multiple bathtub filling operations . The hot water storage type hot water supply device according to claim 1,
A storage type hot water supply device , wherein the predetermined amount is equal to or greater than the amount of stagnant hot water . A hot water storage tank capable of storing hot water heated by a main heat source and discharging hot water for filling a bathtub;
When the bathtub is being filled with hot water, if the temperature of the hot water in the hot water storage tank is insufficient, an auxiliary heat source device heats hot water supplied from the outside without passing through the hot water storage tank, and enables hot water to be supplied for filling the bathtub;
Equipped with
The upper and lower portions of the hot water storage tank are connected to the main heat source by piping, and the hot water storage operation of the hot water storage tank is performed in such a manner that hot water that has been heated by being sent from the lower portion of the hot water storage tank to the main heat source is returned to the upper portion of the hot water storage tank;
A hot water supply device of a storage type, in which a water inlet pipe and a hot water outlet pipe are separately connected to the lower and upper parts of the hot water storage tank, respectively, and hot water is supplied to the bathtub by supplying water from the water inlet pipe to the lower part of the hot water storage tank, and hot water in the upper part of the hot water storage tank flows out to the hot water outlet pipe,
The hot water storage tank further includes a control unit capable of determining whether a specific state occurs in which the retention time of at least a portion of the hot water in the hot water storage tank exceeds a predetermined time,
When the control unit determines that the specific state has occurred, a predetermined amount of hot water in the hot water storage tank is supplied to the bathtub when the bathtub is filled with hot water, regardless of whether the temperature of the hot water in the hot water storage tank is insufficient or not; and
The hot water tank further includes a means for setting a hot water replacement promotion mode for promoting replacement of hot water in the hot water storage tank,
This hot water storage type hot water supply device is characterized in that when the hot water/water replacement promotion mode is set, when the bathtub is filled with hot water, at least a portion of the hot water in the hot water storage tank is supplied to the bathtub, regardless of whether the residence time of at least a portion of the hot water in the hot water storage tank exceeds the specified time and whether the hot water in the hot water storage tank is insufficient in temperature. The hot water storage type hot water supply device according to claim 3 ,
When the control unit determines that the specific state has occurred, a process is further executed to determine an amount of hot water that has been retained in the hot water storage tank for a period exceeding the predetermined period,
A storage type hot water supply device , wherein the predetermined amount is equal to or greater than the amount of stagnant hot water . The hot water storage type hot water supply device according to any one of claims 1 to 4,
This storage-type hot water supply device is configured so that if the hot water in the hot water storage tank is insufficient in temperature when the bathtub is filled with hot water, the hot water coming out of the hot water storage tank and the hot water heated by the auxiliary heat source unit are mixed and supplied to the bathtub . The hot water storage type hot water supply device according to any one of claims 1 to 5,
This storage-type hot water supply device is configured so that if the hot water in the storage tank is insufficient in temperature when the bathtub is being filled with water, hot water heated by the auxiliary heat source unit is further supplied to the bathtub, or the hot water in the bathtub is reheated, so that the hot water in the bathtub is set to a predetermined filling target temperature .

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