JP2940336B2 - Water heater - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to hot water storage temperature control of a hot water storage type water heater.

[0002]

2. Description of the Related Art As shown in FIG. 7, a conventional water heater includes a hot water storage tank 1 covered with a heat insulating material, a water inlet pipe 4 extending from a lower part of the hot water storage tank 1 to a heater 3 via a pump 2, and a hot water storage tank. Tank 1
A hot water pipe 5 reaching the upper part, a hot water temperature detector 6 for detecting hot water temperature in the hot water pipe 5, a water supply pipe 7 at the bottom of the hot water storage tank 1, and a hot water pipe 8 at the top are provided respectively. Reference numeral 9 denotes a water temperature detector provided in the water inlet pipe 4.

The operation of the above configuration will be described.
The heater 3 and the pump 2 are energized in a state where the water supplied into the hot water storage tank 1 from the water supply pipe 7 is full, and the water in the hot water storage tank 1 is guided to the heater 3 via the water inlet pipe 4 by the pump 2. ,
The water is heated by the heater 3, and the hot water flows into the hot water tank 1 and
Hot water is stored from the top of the hot water storage tank 1 in order. Here, tapping pipe 5
The rotation speed of the pump 2 is controlled so that the temperature detected by the hot water temperature detector 6 provided at the first temperature is kept constant at the set temperature T1. The hot water stored in order from the upper part of the hot water storage tank 1 forms a temperature mixing layer as shown in FIG. 8, and the mixed layer advances toward the lower part of the hot water storage tank 1 as the operation time elapses (dotted line in the figure). When the mixed layer reaches the water inlet pipe 4, the inlet water temperature of the heater 3 rises, and since the input of the heater 3 is constant, the temperature detected by the hot water temperature detector 6 rises. Keep the temperature constant. Thereafter, when the water temperature detected by the water temperature detector 9 reaches a predetermined value, the heater 3 and the pump 2 are stopped.

[0004]

However, in the above-mentioned conventional configuration, as shown in FIG.
When entering the lower part, the inlet water temperature of the water inlet pipe 4 rises logarithmically, and accordingly the rotation speed of the pump 2 is increased to increase the water flow rate Q. Since the increase in the flow rate is slow, the detected temperature of the hot water temperature detector 6 rapidly deviates from the constant control of the hot water temperature, and the heater 3
Exceeds the limit temperature Tmax, boiling occurs in the heater 3 and the reliability decreases. When the heater 3 and the pump 2 are stopped at a temperature lower than the limit temperature Tmax in order to prevent the boiling in the heater 3, that is, in a state where the water temperature detected by the water temperature detector 9 is low (TA in the figure), the mixture in the lower part of the hot water tank 1 There was a problem that a layer remained and a predetermined amount of hot water could not be secured.

An object of the present invention is to solve the above-mentioned problems, and an object of the present invention is to provide a water heater that can secure a predetermined amount of hot water without lowering the reliability of the heater.

[0006]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention provides a hot water temperature detector which has a plurality of tap water temperature setting values and detects a water temperature of a tapping pipe, and which corresponds to the plurality of tap temperature setting values. A water temperature detector having a plurality of inlet water temperature setting values and detecting a water temperature of an inlet pipe; and controlling a pump rotation speed so that the detected temperature of the hot water temperature detector becomes the outlet water temperature setting value, and a water temperature detector. When the detected temperature reaches the incoming water temperature set value, the outlet water temperature set value is changed according to the incoming water temperature set value, and when the temperature detected by the water temperature detector reaches the maximum incoming water temperature set value, the heater, The configuration is such that a controller for stopping the pump is provided.

The second means for solving the problems is a hot water temperature detector having a plurality of tapping temperature setting values for detecting the water temperature of the tapping pipe, a pump drive voltage detecting means, and a detecting means for detecting the temperature of the hot water temperature detector. The rotation speed of the pump was controlled so as to reach the tap water temperature set value, and when the detected temperature of the hot water temperature detector exceeded the limit temperature set value, the tap water temperature set value was lowered, and the pump drive voltage became maximum. At this time, a controller for stopping the heater and the pump is provided.

[0008]

According to the present invention having the above-mentioned structure, the number of rotations of the pump is controlled so that the water temperature detected by the hot water temperature detector becomes equal to the set temperature of the hot water, and the hot water of a constant temperature is stored from the top of the hot water storage tank in order. When the temperature reaches the inlet pipe and the temperature detected by the hot water temperature detector rises, the rotation speed of the pump is increased to increase the flow rate of water. Thereafter, when the detected temperature of the water temperature detector rises and reaches the set value of the incoming water temperature, the set value of the tap water temperature is decreased so as to correspond to the set value. The flow rate of water to be pumped is increased by lowering the tap water temperature set value. This operation is repeated, and when the temperature detected by the water temperature detector reaches the maximum water inlet temperature set value, the heater and the pump are stopped.

When the mixed layer of the hot water reaches the inlet pipe, the set point of the outlet water temperature is lowered while monitoring the rise in the inlet water temperature of the inlet pipe, so that the flow rate of the water sent by the pump can be followed to limit the heater. Since the temperature does not exceed Tmax and the boiling is prevented by the heater, the reliability is improved, and the heater and the pump are stopped in a state where the water temperature detected by the water temperature detector is high. A predetermined amount of hot water can be secured without remaining.

According to the second means for solving the problems, when the mixed layer of hot water reaches the water inlet pipe and the temperature detected by the hot water temperature detector rises, the number of rotations of the pump is increased to increase the flow rate of water, and the hot water temperature is increased. When the detected temperature of the detector exceeds the limit temperature set value, the tapping temperature set value is decreased. The flow rate of water to be pumped is increased by lowering the tap water temperature set value. This operation is repeated, and the pump drive voltage detecting means constantly monitors whether the pump voltage is maximum. When the pump voltage reaches the maximum, the heater and the pump are stopped. In this way, it is determined whether or not the hot water enters the mixed layer based on the detected temperature of the hot water temperature detector, the set temperature of the hot water is lowered, and the flow rate of the water sent by the pump is made to follow, so that the limit temperature Tmax of the heater is reached.
, More reliable control can be performed.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIG.

In FIG. 1, the same reference numerals as those in FIG. 7 of the conventional example denote the same members, and have the same functions. Therefore, detailed description will be omitted, and different points will be mainly described. In FIG. 1, reference numeral 10 denotes a tapping temperature set value T1, T2,
A hot water temperature detector T3 has an inlet water temperature setting value TA2, TA3 corresponding to the tap water temperature setting value T2, T3.
3 is a water temperature detector that has a maximum water temperature setting value TA4 for stopping the heater 3, the pump 3, and the water 2, and detects the water temperature of the water inlet pipe 4. Numeral 12 controls the rotation speed of the pump 2 so that the temperature detected by the hot water temperature detector 10 becomes the set value of the hot water temperature, and the temperature detected by the water temperature detector 11 is the set temperature TA2 of the incoming water temperature.
When the temperature reaches TA3, the temperature is changed to the outlet water temperature set values T2 and T3, respectively, in accordance with the incoming water temperature set value. When the temperature detected by the water temperature detector 11 reaches the maximum incoming water temperature set value TA4,
A controller for stopping the heater 3 and the pump 2.

The controller 12 has a specific configuration shown in FIG. In the above configuration, the operation will be described based on the control flow of FIG.

In FIG. 2, when the device is turned on (S1), the pump 2 is driven (S2) and the heater 3 is turned on.
(S3) Next, the hot water temperature To is detected by the hot water temperature detector 10 (S4), and the incoming water temperature Ti is detected by the water temperature detector 11 (S5).

Next, To is compared with the first tapping temperature set value T1, and if To = T1, the process returns to S4, and if not equal, the incoming water temperature Ti is compared with the first incoming water temperature set value TA2 ( S7) If Ti ≧ TA2, the rotation speed of the pump 2 is controlled (S8).

In a normal operation state (a state in which the hot water mixed layer in the hot water storage tank 1 has not reached the water inlet pipe 4), Ti <TA2
S4 → S5 → S6 → S4 or S
The order is 4 → S5 → S6 → S7 → S8 → S4, and the hot water of a constant temperature T1 flowing out of the tapping pipe 5 is stored in order from the top of the hot water storage tank 1.

When the hot water mixed layer in the hot water storage tank 1 reaches the water inlet pipe 4, the water inlet temperature Ti detected by the water temperature detector 11 rises, and Ti ≧ TA2. Next, it is determined whether Ti has reached the second incoming water temperature set value TA3 (S9), and if Ti <TA3, the outlet water temperature set value T1 is changed to the second outlet water temperature set value T2.
Change to (S10) The tap water temperature set value T2 is set lower than T1, and the rotation speed of the pump 2 increases (S10).
8).

Next, returning to S4, the hot water temperature detector 10 detects the hot water temperature To, and the water temperature detector 11 detects the incoming water temperature Ti. (S5) Next, To and the second tapping temperature set value T2
If To = T2, the process returns to S4, and if not equal, the loop of S7 → S9 → S10 → S8 → S4 is repeated.

If the water inlet temperature Ti detected by the water temperature detector 11 further rises and Ti ≧ TA3, it is determined whether or not Ti has reached the maximum water inlet temperature set value TA4, and (S11) Ti <T
If it is A4, the hot water temperature setting value T2 is changed to the third hot water temperature setting value T3. (S12) Hot water temperature set value T3 is T
2, and the rotation speed of the pump 2 increases (S8).

Next, returning to S4, the hot water temperature detector 10 detects the hot water temperature To, the water temperature detector 11 detects the incoming water temperature Ti (S5), and compares To with the second set temperature T3. If To = T3, the process returns to S4, and if not equal, the loop of S4 → S7 → S9 → S11 → S12 → S8 → S4 is repeated.

If the water inlet temperature Ti detected by the water temperature detector 11 further rises and Ti ≧ TA4 (S11), it is determined that Ti has reached the maximum water inlet temperature set value TA4, and the heater 3,
Pump 2 is stopped. (S13, S14) The above operations are performed by the controller 12.

According to the structure of this embodiment, as shown by the dotted line in FIG. 8, the detected temperature Ti rises while monitoring with the water temperature detector 11 that the hot water mixed layer in the hot water storage tank 1 has reached the water inlet pipe 4. When the water inlet temperature set values TA2 and TA3 are reached, the outlet water temperature set values T2 and T3 are decreased to correspond to the set values. The flow rate of the water sent by the pump 2 is increased by lowering the tapping temperature set value. This operation is repeated, and when the temperature Ti detected by the water temperature detector 11 reaches the maximum water inlet temperature set value TA4, the heater 3 and the pump 2 are stopped to thereby stop the water temperature at the inlet of the heater 3, that is, the water temperature detector 11
Can be operated up to a temperature TA4 at which the temperature Ti detected is higher than TA, and a temperature mixed layer is less likely to remain at the lower part of the hot water storage tank 1,
A predetermined amount of hot water can be secured, and the tap water temperature set value T1 to T
By lowering the temperature to 3, the flow rate of the water sent by the pump 2 is followed so as not to exceed the limit temperature Tmax of the heater 3, and the reliability is improved by preventing the heater 3 from boiling.

Next, a second embodiment of the present invention will be described with reference to FIG.
This will be described with reference to FIGS. 4, the same reference numerals as those in the first embodiment shown in FIG. 1 denote the same members, and have the same functions. Therefore, detailed description will be omitted, and different points will be mainly described.

As shown in FIG. 4, reference numeral 13 is provided in the tapping pipe 5 and has a tapping temperature set value T1, T2, T3 and a limit temperature value T4 for judging whether to change the tapping temperature set value. A hot water temperature detector is provided. Reference numeral 14 denotes drive voltage detecting means for detecting a drive voltage of the pump 2. Reference numeral 15 controls a rotation speed of the pump 2 so that a detected temperature of the hot water temperature detector 13 becomes a set value of tap water. When the temperature detected by the hot water temperature detector 13 reaches the limit temperature set value T4, the set temperature of the hot water is changed from T1 to T2 and T3 step by step, and the pump drive voltage detected by the pump drive voltage detection means 14 is used. This is a controller that stops the heater 3 and the pump 2 when the drive voltage reaches the maximum.

The controller 15 has the structure shown in FIG. In the above configuration, the operation is performed in steps S15 to S15.
A description will be given based on the control flow of FIG.

In FIG. 5, when the device is turned on, the pump 2 is driven and the heater 3 is turned on (S15 to S16).

Next, the hot water temperature To is detected by the hot water temperature detector 10 (S17), and To is compared with the first set temperature T1. If To = T1, the process returns to S17. To is compared with the limit temperature value T4. (S1
8, 19) If To ≧ T4, the rotation speed of the pump 2 is controlled (S19, S20).

In a normal operation state (a state in which the hot water mixed layer in the hot water storage tank 1 has not reached the water inlet pipe 4), To <T4, and S17 → S18 → S17 or S1 in the flow shown in FIG.
The loop of 7 → S18 → S19 → S20 → S17 is repeated, and the hot water of the constant temperature T1 coming out of the tapping pipe 5 is stored in order from the top of the hot water storage tank 1.

When the hot water mixed layer in the hot water storage tank 1 reaches the water inlet pipe 4, the water temperature at the inlet of the water inlet pipe 4 increases logarithmically, and the hot water temperature T
1 Deviating from the constant control, the detection temperature T of the hot water temperature detector 10
o increases, and To ≧ T4. This is determined in S19, and then it is determined in S20 whether or not the hot water temperature set value T2 has been reached. Next, it is determined whether the set value is the minimum tapping temperature set value T3. (S21) Since the tapping temperature set value is T1 for the first time, the temperature is changed from T1 to the second set value T2. (S2
2) Next, the drive voltage VT of the pump 2 is detected by the pump drive voltage detection means 14. (S23) Since the detected drive voltage VT of the pump 2 has not reached the maximum drive voltage VMAX (S24), the rotation speed of the pump 2 is controlled. (S
25) Here, the tap water temperature set value T2 is set lower than T1, and the rotation speed of the pump 2 increases to increase the water flow rate.

Next, returning to S17, the hot water temperature detector 13 detects the hot water temperature To, and determines To and the second tapping temperature set value T2.
If To = T2, the process returns to S17, and if not, the loop of S17 → S18 → S19 → S25 → S17 is repeated.

Further, the water temperature at the inlet pipe 4 rises, and T
If o ≧ T4, it is determined in S20 whether or not the tapping temperature set value T2 has been reached, and the tapping temperature set value is changed from T2 to a third set value T3. (S26) Next, the drive voltage VT of the pump 2 is detected by the pump drive voltage detection means 14.
(S22) Since the detected drive voltage VT of the pump 2 has not reached the maximum drive voltage VMAX (S24), the rotation speed of the pump 2 is controlled. (S25) Here, the tap water temperature set value T3 is set lower than T2, and the rotation speed of the pump 2 increases again to increase the water flow rate. Next, returning to S17, the hot water temperature detector 13 detects the hot water temperature To, and compares To with the third tapping temperature set value T3. If To = T3, return to S17; otherwise, return to S17 → S18. → S
Repeat the loop of 19 → S25 → S17 and repeat To ≧
At T4, S19 → S20 → S21 → S23 → S24
And the drive voltage VT of the pump 2 is the maximum drive voltage VMA
X, the heater 3 and the pump 2 are stopped (S
27, S28).

According to the configuration of this embodiment, as shown in FIG. 6, the hot water temperature detector 13 monitors that the hot water mixed layer in the hot water tank 1 has reached the water inlet pipe 4, and the detected temperature To rises. When reaching the limit temperature set value T4, the tap water temperature set value T1
→ T2 → T3 and increase the flow rate of water sent by the pump 2. This operation is repeatedly performed, and the pump driving voltage detecting means 14 constantly monitors whether the pump 2 voltage is maximum.
Is stopped, the heater 3 can be operated up to the inlet water temperature, that is, the inlet pipe 4 inlet temperature, the temperature mixing layer is less likely to remain at the lower part of the hot water storage tank 1, a predetermined amount of hot water can be secured, and the hot water temperature detector 13 , The control can be performed so as not to exceed the limit temperature Tmax of the heater 3, and boiling in the heater 3 can be prevented.

[0033]

As described above, the water heater of the present invention has the following features.
A hot water tank, a water inlet pipe from the lower part of the hot water tank to the heater via the pump, a hot water pipe from the heater to the upper part of the hot water tank, and a hot water temperature detector having a plurality of hot water temperature setting values and detecting the water temperature of the hot water pipe. A water temperature detector having a plurality of inlet temperature set values corresponding to the plurality of set temperature values and detecting a water temperature of an inlet pipe; and a pump having a hot water temperature detector so that the detected temperature of the hot water temperature detector becomes the outlet water temperature set value. When the rotation speed is controlled, and the temperature detected by the water temperature detector reaches the set temperature of the incoming water, the set temperature of the tap water is changed according to the set value of the incoming water temperature, and the temperature detected by the water temperature detector is the maximum incoming water. By installing a controller that stops the heater and pump when the temperature reaches the set temperature, when the mixed layer of hot water reaches the inlet pipe, it monitors the rise in inlet water temperature of the inlet pipe while lowering the outlet temperature set point. And follow the water flow sent by the pump In order to prevent the temperature from exceeding the limit temperature Tmax of the heater and prevent boiling in the heater, the reliability is improved, and the heater and the pump are stopped when the water temperature detected by the water temperature detector is high. Thus, a predetermined amount of hot water can be secured without leaving a temperature mixed layer.

Also, the present invention provides a hot water temperature detector which has a plurality of tap water temperature setting values and detects a water temperature of a tap water pipe, a pump drive voltage detecting means, and a detection temperature of the hot water temperature detector is a tap water temperature setting value. Control the rotation speed of the pump so as to reduce the tap water temperature set value when the detected temperature of the hot water temperature detector exceeds the limit temperature set value, and when the pump drive voltage is maximized, the heater, By providing a controller that stops the pump, it is determined whether or not the hot water temperature detector has entered the mixed layer of hot water at the detected temperature, and the tap water temperature set value is reduced,
The water flow rate sent by the pump is made to follow, and the temperature limit T
In order not to exceed max, more reliable control can be performed, and the above-mentioned effect can be obtained.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of a water heater according to an embodiment of the present invention.

FIG. 2 is a control flow chart of the water heater.

FIG. 3 is a characteristic diagram showing a relationship between time, temperature, and water flow rate of the water heater.

FIG. 4 is a configuration diagram of a water heater according to another embodiment of the present invention.

FIG. 5 is a control flow chart of the water heater.

FIG. 6 is a characteristic diagram showing a relationship between time, temperature, and water flow rate of the water heater.

FIG. 7 is a configuration diagram of a conventional water heater.

FIG. 8 is a characteristic diagram showing the height of a hot water tank and the temperature in the hot water tank of a conventional water heater.

FIG. 9 is a characteristic diagram showing a relationship between time, temperature, and water flow rate of a conventional water heater.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Hot water storage tank 2 Pump 3 Heater 4 Water inlet pipe 5 Hot water pipe 10, 13 Hot water temperature detector 11 Water temperature detector 12, 15 Controller 14 Pump drive voltage detecting means

────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-6-123496 (JP, A) JP-A-2-263040 (JP, A) (58) Fields investigated (Int. Cl. ⁶ , DB name) F24H 1/18 302

Claims (2)

(57) [Claims] 1. A hot water tank, a water inlet pipe from a lower part of the hot water tank to a heater via a pump, a hot water pipe from the heater to an upper part of the hot water tank, and a plurality of hot water temperature setting values for controlling the hot water temperature of the hot water pipe. A hot water temperature detector to detect, a water temperature detector having a plurality of inlet temperature set values corresponding to the plurality of temperature set values, and detecting a water temperature of an inlet pipe, and a detected temperature of the hot water temperature detector being a tap water temperature set value. When the rotation speed of the pump is controlled so that the water temperature detector reaches the set water temperature,
A water heater provided with a controller that changes the outlet water temperature set value according to the inlet water temperature set value, and stops a heater and a pump when the temperature detected by the water temperature detector reaches the maximum incoming water temperature set value. 2. A hot water tank, a water inlet pipe from a lower part of the hot water tank to a heater via a pump, a hot water pipe from the heater to an upper part of the hot water tank, and a plurality of hot water temperature setting values for detecting a water temperature of the hot water pipe. Hot water temperature detector, pump drive voltage detection means, and control the number of rotations of the pump so that the detected temperature of the hot water temperature detector becomes the set value of tap water, and the detected temperature of the hot water temperature detector sets the limit temperature. A water heater provided with a controller for lowering the tapping temperature set value when the value exceeds the value, and for stopping the heater and the pump when the pump drive voltage is maximized.