JPH05106919A - Hot water storage type hot water supply device - Google Patents

Abstract

PURPOSE:To greatly reduce the frequency of the delivery of water, the temperature of which has not reached a temperature required for filling water and prevent an interruption of hot water supply by providing a hot water storage tank which pumps up water, utilizing the midnight electric power and a plurality of hot water storage tanks which are exclusively used for storing hot water and controlling the transfer of water among the storage tanks. CONSTITUTION:A first hot water storage tank 11 in which the inside water is boiled by an electric heater 14 and second and third hot water storage tanks 12, 13 which are exclusively used for storing hot water are provided. And, in the third tank 13 the water volume X of the water which is not yet heated is calculated based on the outputs of a plurality of temperature sensors provided longitudinally in the third tank with a distance among them by a controller 4. And, based on the water volume X and water temperature T1, T2 by temperature sensors 1, 2 which are attached to the tanks 11, 12 the water temperature T2' in the second tank 12 which changes when all the water volume X is transferred from the third tank 13 to the first tank 1 when this T2' is higher than a specified temperature T0 for the filling water temperature, transfer of the water that goes to the first hot water tank 11 is started.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hot water storage type hot water supply apparatus having one hot water tank and two dedicated hot water tanks.

[0002]

2. Description of the Related Art Conventionally, as this type of hot water storage type hot water supply device,
For example, the one shown in FIG. 3 is known (actual Kaihei 3
No. 18454). This water heater has an electric heater 1
1st hot water storage tank 11 with built-in 4 and 2nd dedicated hot water reservoir,
The third hot water storage tanks 12 and 13 are erected, the hot water supply pipe 15 is provided on top of the first and second hot water storage tanks 11 and 12, and the water is supplied to the bottoms of the first and third hot water storage tanks 11 and 13 through the three-way valve 17. Piping 1
6 are connected to each other, and the bottom of the second hot water storage tank 12 and the top of the third hot water storage tank 13 are connected by a pipe 18. Further, one end 1 of the circulation pipe 19 having the pump 20 and the condenser 21 interposed therebetween.
9a is connected to the bottom of the first hot water storage tank 11, while the other end 19 of the circulation pipe 19 is branched into two via a three-way valve 22.
b and 19c are connected to the bottoms of the first and third hot water storage tanks 11 and 13, respectively. Further, the controller 25 receives a detection signal from the temperature sensor 23 that detects the water temperature at the top of the first hot water storage tank 11 and the temperature sensor 24 that detects the water temperature at the bottom of the third hot water storage tank 13, and the controller 25 receives the electric heater. 14, the operation of the condenser 21, the pump 20, and the three-way valves 17 and 22 are controlled.

The controller 25 operates the electric heater 14 with inexpensive nighttime electric power to heat all the water in the first hot water storage tank 11 to the boiling temperature (for example, 80 ° C.). Next, the three ports of the three-way valve 17 are fully closed, and the three-way valve 22 is switched so as to communicate with the third hot water tank 13 side.
The pump 20 of 9 is activated to transfer the boiling water from the top of the first hot water storage tank 11 to the second hot water storage tank 12, and the water in the third hot water storage tank 13 from the bottom thereof to the first hot water storage tank 11 And the temperature sensor 23 of this tank
When the temperature of the water surface rising due to the transfer is detected, the pump 20 is stopped and the transfer ends. After that, the water filled in the first hot water storage tank 11 is boiled again by the electric heater 14 and similarly transferred to the second hot water storage tank 12. By repeating this operation, the boiled hot water becomes the third hot water storage tank 13
When the temperature reaches the bottom of the tank, the temperature sensor 24 of this tank detects the hot water temperature, which causes the controller 25 to stop the electric heater 14 assuming that the boiling water has accumulated in all three tanks. , Finish boiling water.

When hot water is discharged in the daytime, the controller 25 switches the three-way valve 17 to the side of the first hot water storage tank 11 to turn the three-way valve 2 on.
All the ports 2 are closed, tap water is supplied from the water supply pipe 16, and a hot water supply tap (not shown) of the hot water supply pipe 15 is opened. Then, the boiling water in the first hot water storage tank 11 is
It is pushed up by the water supply from the bottom and tapped from the hot water supply pipe. When the temperature of the water in the tank decreases due to tap water and water supply, all ports of the three-way valve 17 are closed, additional heating is performed, the three-way valve 22 is switched to the first hot water storage tank 11 side, the pump 20 is started, and the condenser 21 is connected. The compressor of the continuous refrigeration circuit (not shown) is started. Then, the water in the tank 11 is condensed by the condenser 21.
It circulates through and is heated to about 30 ° C. When tapping hot water from the second hot water storage tank 12, all ports of the three-way valve 22 are closed, the three-way valve 17 is switched to the third hot water storage tank 13 side, and tap water is supplied from the water supply pipe 16. Then,
The hot water in the third hot water storage tank 13 is pushed up by the water supply from the bottom, is transferred to the bottom of the second hot water storage tank 12 via the pipe 18, and the hot water in the second hot water storage tank 12 is pushed up, and the hot water is discharged from the hot water supply pipe 15. To be done. Even when hot water is discharged during the daytime, tap water is transferred from the bottom of the third hot water storage tank 13 to the first hot water storage tank 11 in the same route as at night in order to transfer the water warmed by the additional heating by the condenser 21. It is done as appropriate.

[0005]

However, in the conventional hot water storage type hot water supply apparatus described above, even when water is transferred to the first hot water storage tank 11 in the daytime, the temperature sensor 23 at the top of the tank detects the temperature of tap water. Since the transfer is continued, the following problems occur. That is, for example, when water is transferred when the temperature distribution in each tank is as shown in FIG. 3, all 0 ° C. water in the third tank 13 moves to the first tank 11,
All of the 30 ° C water in tank 11 is transferred to the second tank 12,
The transfer continues until part of the 75 ° C. hot water in the second tank 12 is transferred to the third tank 13. Therefore, the second tank 1 after transfer
The average hot water temperature T ₂ 'of ₂ is T ₂ ' = (30 ° C × 100l + 75 ° C
× 50l) / 150l = 45 ° C. However, if hot water is discharged from the second hot water storage tank in this state, the hot water to be supplied becomes 45 ° C., which cannot be used as a hot water supply for a bath that requires high temperature hot water. Therefore, an object of the present invention is to carry out water transfer only when the hot water temperature in the hot water tank after the water transfer is high or when hot water runs out, thereby preventing the occurrence of low-temperature hot water and hot water shortage. It is to provide a hot water storage type hot water supply device that can be prevented.

[0006]

In order to achieve the above object, the hot water storage type hot water supply apparatus of the present invention is, as illustrated in FIG. 1, a first hot water storage tank in which water inside is boiled by heating means 14 and 21. 11 and second and third hot water storage tanks 12 and 13 dedicated to the hot water storage are erected, and the first and second hot water storage tanks 11 and
A hot water supply pipe 15 is provided on the top of 12 and a water supply pipe 16 is provided on the bottom of the first and third hot water storage tanks 11 and 13 via a switching valve 17.
And the bottom of the second hot water storage tank 12 and the top of the third hot water storage tank 13 are connected by a pipe 18, and one end 19a of a circulation pipe 19 provided with a pump 20 is connected to the bottom of the first hot water storage tank 11. The other end 19b of the circulation pipe 19 which is connected to the other end and is branched into two via a three-way valve 22.
19c is connected to the bottoms of the first and third hot water storage tanks 11 and 13, respectively, and is provided with a controller 4 for controlling the operations of the heating means 14 and 21, the pump 20, the switching valve 17 and the three-way valve 22. In the above, the first and second hot water storage tanks 11 and 1
Temperature T ₁ of the the 2, T ₂ first to respectively detect a second temperature sensor 1, longitudinally spaced a predetermined distance to the third hot-water storage tank 13, detects the water temperature Ti in the tank A plurality of third temperature sensors 3a to 3g, and the third temperature sensors 3 described above.
A water amount detecting means 4 for obtaining the water amount X of unheated water in the third hot water storage tank 13 depending on whether or not the water temperature represented by the detection signal Ti of a to 3 g is below a predetermined value, the water amount X and the first and the first Two
Based on the water temperatures T ₁ and T ₂ represented by the detection signals of the temperature sensors 1 and ₂ , when the pump 20 transfers all the water of the above water amount X from the third hot water storage tank 13 to the first hot water storage tank 11, the first hot water storage 'and tapping temperature calculation means 4 for calculating a, the hot water temperature calculating means temperature T ₂ calculated by the 4' second temperature T ₂ of the hot water storage tank 12 after transfer changed by water flowing from the tank 11 reaches a predetermined First discriminating means 4 for discriminating whether or not it is equal to or higher than the hot water temperature T ₀ , and when the first discriminating means 4 judges no, the water amount X obtained by the water amount detecting means 14 is a predetermined value X. _When the second discriminating means 4 for discriminating whether or not it is ₀ or more and either the first or second discriminating means 4 discriminates affirmatively, the three-way valve 22 is communicated to the third hot water storage tank 13 side. , The pump 20 is activated to start the first hot water storage tank 11 Characterized by comprising a transfer initiation means 4 for starting the transfer of water towards.

[0007]

Before the transfer of water from the third hot water storage tank 13 to the first hot water storage tank 11, the water amount detecting means 4 includes the third temperature sensors provided in the third hot water storage tank 13 at predetermined intervals in the vertical direction. The water amount Ti of the unheated water in the third hot water storage tank 13 is determined depending on whether or not the water temperature Ti represented by the detection signals 3a to 3g is equal to or lower than a predetermined value. Next, the outlet heated water temperature calculation means 4 determines the amount of water X based on the water temperatures T ₁ and T ₂ indicated by the detection signals of the first and second temperature sensors 1 and 2 provided in the first and second hot water storage tanks 11 and 12. When all the water is transferred from the third hot water storage tank 13 to the first hot water storage tank 11 by the pump 20,
The water temperature T ₂ 'in the second hot water storage tank 12 after transfer, which changes depending on the water flowing from the first hot water storage tank 11, is calculated. The first determining means 4 determines whether or not the calculated water temperature T ₂ 'is below a predetermined hot water temperature T ₀ . Also, the first
When the determination means 4 determines NO, the second determination means 4 determines whether or not the water amount X obtained by the water amount detection means 4 is equal to or greater than the predetermined value X ₀ . Then, the transfer starting means 4 determines that when either the first or the second determining means 4, 4 determines that the result is positive,
In the former case, it is assumed that hot water having a hot water temperature of T ₀ or higher is discharged, and in the latter case, a small amount of discharged water causes shortage of hot water.
The three-way valve 22 is switched to communicate with the third hot water storage tank 13 side, the pump 20 is started, and the transfer of water toward the first hot water storage tank 11 is started. Therefore, it is possible to prevent the low temperature hot water from coming out and the hot water to run out, thereby improving the usability of the apparatus.

[0008]

The present invention will be described in detail below with reference to the embodiments shown in the drawings. FIG. 1 is a schematic view showing an example of a hot water storage type hot water supply apparatus. This hot water supply apparatus has the same members as those in FIG. 3 except that the temperature sensor is installed and the controller functions differently from the conventional example described in FIG. Have the same number. On the side wall of the third hot water storage tank 13, as a third temperature sensor, the water temperature Ti (i = 3 to 9) in the tank is vertically spaced at regular intervals from the top to the bottom.
Seven temperature sensors 3a to 3g for detecting the temperature are provided. Also,
At the central portions of the side walls of the first and second hot water storage tanks 11 and 12, temperature sensors ₁ and ₂ for detecting the water temperatures T ₁ and T ₂ in the respective tanks are provided as the first and second temperature sensors ( (See S1 in FIG. 2).

The controller 4 is the conventional controller 25 (see FIG. 3).
(See), and also serves as a water amount detecting means, a hot water outlet temperature calculating means, first and second determining means, and a transfer starting means, which will be described later. That is, the controller 4 serves as a water amount detecting means and represents the water temperature T indicated by the detection signals of the temperature sensors 3a to 3g.
The amount X of unheated water in the third hot water storage tank 13 is determined depending on whether i is equal to or lower than the maximum temperature (for example, 20 ° C.) of tap water supplied from the water supply pipe 16. In other words, since the water supply always accumulates on the bottom side of the tank, the detected water temperature Ti is 20
Assuming that the water below the temperature sensor below ℃ (two-dot chain line of the tank) is unheated, find the water amount X at the installation height of the temperature sensor.
(See S2 in FIG. 2). Further, the controller 4 serves as a hot water outlet temperature calculating means based on the water temperatures T ₁ and T ₂ represented by the detection signals of the temperature sensors 1 and ₂ and pumps all the water of the above water amount X from the third hot water storage tank 13 to the third hot water storage tank 13. When the water is transferred to the first hot water storage tank 11, the water temperature T ₂ 'in the second hot water storage tank 12 after the transfer, which changes depending on the water flowing from the first hot water storage tank 11, is calculated. That is, assuming that the volumes of the first and second tanks 11 and 12 are V ₁ and V ₂ and the amount of transferred water is X, the heat balance of the second tank 12 before and after the transfer gives T ₂ 'V ₂ = T ₁ X + T ₂ (V _2- X)
Holds, T ₂ '= {T ₁ X + T ₂ (V ₂ −X)} / V ₂
T ₂ 'is calculated by the formula (see S3).

Further, the controller 4, as a first discriminating means, discriminates whether or not the calculated water temperature T ₂ 'is equal to or higher than a predetermined hot water temperature T ₀ (for example, 60 ° C.) (see FIG. 2). When it is determined to be no, as the second determining means, it is determined whether or not the water amount X is equal to or more than a predetermined value, that is, the maximum water amount X ₀ at which no hot water runs out (see the same S5). ..
Then, when it is determined to be affirmative by either of the above determinations,
As a transfer starting means, the three-way valve 22 is used as the third hot water storage tank 13.
Switch to the side and start pump 20
Start the transfer of water to the hot water storage tank 11 (S6)
reference). It should be noted that the transfer is started based on the former affirmative determination when the amount T ₂ ′ of water in the second hot water storage tank 12 after the transfer is the hot water temperature T.
_{This is because if it is 0} or more, there is no hindrance to hot water, and the reason for opening the transfer in the latter case is that the amount of remaining hot water is so small that water runs out unless the water is transferred and boiled in the first hot water storage tank 11. ..

The operation of the hot water storage type hot water supply apparatus having the above configuration will be described with reference to FIG.
Will be described next with reference to. Hot water boiled by the electric heater 14 at night is stored in all the hot water storage tanks 11, 12, 13 and is supplied to the bottom of the first or third hot water storage tank through the water supply pipe 16 and the three-way valve 17 in the daytime. With water, first
Or the hot water supply pipe 1 from the top of the second hot water storage tank 11, 12
Hot water is discharged after 5 minutes. The third hot water storage tank 13 along with the hot water
When the tap water in the inside increases, it is transferred to the first hot water storage tank 11 in order to heat it in the condenser 21 to about 30 ° C. Prior to the transfer, the controller 4 receives the detection signals of the temperature sensors 3a to 3g vertically provided in the third hot water storage tank 13 in step S2, and the water temperature Ti represented by this signal is 20 ° C.
The water amount X of the unheated water in the third hot water storage tank 13 is determined depending on whether or not it is the following. Next, in step S3, after transfer based on the water temperatures T ₁ and T ₂ indicated by the detection signals (see step S1) of the first and second temperature sensors 1 and 2 provided in the first and second hot water storage tanks 11 and 12, respectively. The water temperature T ₂ 'in the second hot water storage tank 12 is calculated by the following formula. _{T 2 '= {T 1 X} + T 2 (V 2 -X)} / V 2

The controller 4 indicates that the calculated water temperature T ₂ 'is
In step S4, it is determined whether or not the temperature is equal to or higher than the predetermined hot water temperature T ₀ (60 ° C.). When it is determined that the answer is yes, the process proceeds to step S6, and even if the water is transferred to the first hot water storage tank 11, it is determined that the hot water having the hot water temperature T ₀ or higher can be discharged from the second hot water storage tank 12, and the three-way valve 17 All ports are closed, the three-way valve 22 is switched to the first hot water storage tank 13 side, the pump 20 is started, and the transfer of water from the third hot water storage tank 13 to the first hot water storage tank 11 is started. This transfer is performed when the temperature sensor 23 at the top of the first hot water storage tank 11 detects the boundary level (water temperature) between water and hot water that rises during the transfer, or the temperature sensor 3 at the bottom of the third hot water storage tank.
g is the interface level between water and hot water that descends during transfer (hot water temperature)
Ends when is detected. After that, all ports of the three-way valve 22 are closed, the three-way valve 17 is switched to the side of the third hot water storage tank 13, and water is supplied from the water supply pipe 16 to the third hot water storage tank 13, whereby the hot water in the second hot water storage tank 12 is supplied. Temperature T
Hot water having a temperature of ₀ or higher is discharged from the top through the hot water supply pipe 15.

On the other hand, if it is determined to be no in step S4, the process proceeds to step S5, and it is determined whether or not the water amount X obtained in step S3 is a predetermined value X ₀ or more. Then, if it is determined to be affirmative in step S5, the process proceeds to step S6, and it is necessary to boil the water because there is a possibility that the hot water will run out with a small amount of hot water remaining, so it is assumed that the third hot water tank 13
The transfer of water from the first hot water storage tank 11 to the first hot water storage tank 11 is started. This transfer is also completed in the same manner as described above, and the three-way valve 22 is connected to the first hot water storage tank 11 with all ports of the three-way valve 17 closed.
Then, the pump 20 and the condenser 21 are activated to heat the water transferred to the first hot water storage tank 11 to about 30 ° C. If it is determined to be no in step S5, the third hot water storage tank 13 has sufficient hot water so that the hot water does not run out and the water is not transferred.

In this way, the frequency with which low-temperature hot water below the hot water supply temperature (60 ° C.) is discharged from the hot water supply pipe 15 is greatly reduced, and outage of hot water is prevented, so the usability as a hot water supply device is improved. However, it becomes very convenient for the user. In the above embodiment, the electric heater 14,
Since the controller 4 for controlling the condenser 21, the pump 20 and the three-way valves 17, 22 also functions as the outlet heated water temperature calculating means, the first and second determining means, and the transfer starting means, the apparatus is relatively simple and There is an advantage that it can be constructed at low cost. Although the electric heater 14 and the condenser 21 are provided as the heating means in the above embodiment, either one of them may be used.

[0015]

As is clear from the above description, the hot water storage type hot water supply apparatus of the present invention comprises the first hot water storage tank having the first temperature sensor and the heating means and also serving as the heating, and the second temperature sensor dedicated to the hot water storage. The second hot water storage tank and the third hot water storage tank are installed upright, and hot water supply pipes and water supply pipes with a switching valve are connected to the top and bottom of these tanks respectively, and the pump and the three-way valve and the heating installed in the circulation pipe are connected. In the one in which the operation of the means is controlled by the controller, a plurality of third temperature sensors are provided in the third hot water storage tank, and the amount of unheated water in the tank is obtained by the water amount detection means that receives detection signals from these sensors. When all the water is transferred to the first hot water storage tank by the pump, the water temperature in the second hot water storage tank after transfer that changes due to the inflow water from the first hot water storage tank is based on the water temperature by the first and second temperature sensors. Calculated by outlet temperature calculation means On the other hand, whether or not the calculated water temperature is equal to or higher than the hot water temperature is determined by the first determination means, and when determined as negative, the second determination means determines whether or not the water amount is equal to or higher than a predetermined value. When either of the determination means determines that the answer is affirmative, the transfer start means switches the three-way valve to the third hot water storage tank side and starts the pump to start the transfer of water to the first hot water storage tank. The frequency with which hot water below the temperature of the hot water is discharged is greatly reduced, the occurrence of hot water runout is prevented, and usability as a hot water supply device is improved.

[Brief description of drawings]

FIG. 1 is a schematic view showing an embodiment of a hot water storage type hot water supply apparatus of the present invention.

FIG. 2 is a flowchart showing a flow of operations of the hot water storage type hot water supply device.

FIG. 3 is a schematic diagram showing a conventional hot water storage type hot water supply device.

[Explanation of symbols]

1 ... 1st temperature sensor, 2 ... 2nd temperature sensor, 3a-3g ...
Third temperature sensor, 4 ... Controller, 11 ... First hot water storage tank,
12 ... 2nd hot water storage tank, 13 ... 3rd hot water storage tank, 14 ...
Electric heater, 15 ... Hot water supply pipe, 16 ... Water supply pipe, 17 ...
Three-way valve, 18 ... Piping, 19 ... Circulation piping, 19a ... One end,
19b ... other end, 20 ... pump, 21 ... condenser, 22 ... three-way valve.

Claims (1)

[Claims] 1. A first hot water storage tank (11) in which internal water is boiled by heating means (14, 21) and second and third hot water storage tanks (12, 13) dedicated to hot water storage are provided upright. A hot water supply pipe (15) at the top of the first and second hot water storage tanks (11, 12)
A switching valve at the bottom of the first and third hot water storage tanks (11, 13)
The water supply pipes (16) are connected to each other via (17), and the second
The bottom of the hot water storage tank (12) and the top of the third hot water storage tank (13) are connected by a pipe (18), and one end (19a) of a circulation pipe (19) having a pump (20) is connected to the first hot water storage tank. The other end (19b, 1) of the circulation pipe (19) is connected to the bottom of the tank (11) and is branched into two via a three-way valve (22).
9c) are connected to the bottoms of the first and third hot water storage tanks (11, 13) respectively, and the operation of the heating means (14, 21), the pump (20), the switching valve (17) and the three-way valve (22) is performed. Controller to control
In the hot water storage type hot water supply device comprising (4), the water temperature (T ₁ , T ₁ in the first and second hot water storage tanks (11, 12)
T ₂ ), respectively, and first and second temperature sensors (1, 2) for detecting water temperature (Ti) in the third hot water storage tank (13) at predetermined intervals in the vertical direction. Multiple thirds to do
Unheated in the third hot water tank (13) depending on whether or not the water temperature (Ti) represented by the detection signals of the temperature sensors (3a to 3g) and the third temperature sensors (3a to 3g) is below a predetermined value. Based on the water amount detecting means (4) for obtaining the water amount (X) of the water, and the water temperature (T ₁ , T ₂ ) indicated by the detection signals of the water amount (X) and the first and second temperature sensors ( ₁ , ₂ ) , The above-mentioned amount (X) of water is first supplied from the third hot water storage tank (13) to the first by the pump (20).
The first hot water storage tank when transferred to the hot water storage tank (11)
Outlet temperature calculating means (4) for calculating the water temperature (T ₂ ') in the second hot water storage tank (12) after transfer that changes depending on the water flowing in from (11), and this outlet temperature calculating means (4) The first to determine whether the water temperature (T ₂ ') is equal to or higher than a predetermined hot water temperature (T ₀ ).
Whether the water amount (X) obtained by the water amount detecting means (4) is equal to or more than a predetermined value (X ₀ ) when the judging means (4) and the first judging means (4) judge no. When either the second discriminating means (4) for discriminating whether or not the first or second discriminating means (4) discriminates the affirmative, the three-way valve (22) is connected to the third hot water storage tank (13) side. A hot water storage type hot water supply apparatus comprising: a transfer start means (4) for switching to the first hot water storage tank (11) by activating the pump (20).