JPH08200804A - Supplying apparatus for hot water - Google Patents

Abstract

PURPOSE: To prevent disagreeable high-temperature water from being turned on when a faucet is turned on, by a method wherein either a first temperature condition for maintaining water temperature in a heat-exchanger for hot-water supply at a low temperature or a second temperature condition for maintaining the water temperature therein at a high temperature is selected, and the condition selected is inputted to a heat amount-controlling part. CONSTITUTION: When an amount Q of hot water supplied is lowered from a significant value to an insignificant value, that hot-water supply should be stopped is determined by a determining part 18 for either hot-water supply or additional heating operation, and timer 19 is started in order to measure the time elapsed after stopping of the hot-water supply. The state of the timer 19 is monitored by a transferring part 20, and only during the timing action of the timer 19, a first target temperature and a first maximum temperature, which are stored in a first temperature-storing part 17a, are selected. A second target temperature and a second maximum temperature, which are stored in a second temperature-storing part 17b, are selected, except during the timing action of the timer 19, following which they are respectively inputted to a heat amount-operating part 14 as a target temperature Tzs of a heat- exchanger for the hot-water supply and a maximum temperature Tzm thereof, and a heat amount necessary for additional heating is operated. In this way, water can be maintained at a proper temperature.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a so-called one-can-two system in which a hot-water supply heat exchanger for supplying hot water to a hot-water tap and a reheating heat exchanger for reheating hot water in a bathtub are heated by the same heating section. A waterway type hot water supply device.

[0002]

2. Description of the Related Art Generally, in a hot water supply apparatus that heats a hot water supply heat exchanger and an additional heating heat exchanger by the same heating unit, water in the hot water supply heat exchanger boils when only additional heating is performed. In order not to do so, the combustion amount during the additional firing operation is controlled.

FIG. 5 shows a conventional method for controlling a hot water supply device. First, if hot water is in use (step S1-YE
S), and then it is determined whether or not the additional heating switch is on (step S2). Then, when the additional heating switch is on, combustion is performed with a heat amount that is a combination of the required combustion amounts of both hot water supply and additional heating, and the circulation pump for additional heating is driven (step S3). On the other hand, when the additional heating switch is off, combustion is performed only with the required heat amount for hot water supply, and the circulation pump for additional heating is not driven at this time (step S4).

On the other hand, when hot water supply is not in use (step S1-NO), it is next determined whether or not the additional heating switch is on (step S5). When the additional heating switch is off, combustion is stopped. Alternatively, the combustion stopped state is maintained (step S6), and the process returns to step S1. On the other hand, when the additional heating switch is turned on in step S5, the circulation pump is driven (step S7), and then the water temperature TZ of the heat exchanger for hot water supply.
Is above 90 ° C. (= upper limit temperature for not boiling) (step S8). If YES, combustion is stopped and the rotation speed of the supply / exhaust fan is increased to positively. Cooling (step S9), step S
Return to 1.

On the other hand, if the water temperature TZ of the hot water supply heat exchanger is 90 ° or less in step S8, then the water temperature T
It is determined whether or not Z exceeds 80 degrees Celsius (= target temperature for water temperature TZ) (step S10), and 80 degrees Celsius.
In the following cases, after starting combustion, if not burning,
Alternatively, if combustion is in progress, the combustion amount is increased in that state (step S12) and the process returns to step S1. On the other hand, step S1
At 0, if the water temperature TZ exceeds 80 ° C., the combustion amount is reduced while continuing combustion (step S1
1) and returns to step S1.

[0006]

However, in the above-mentioned conventional hot water supply apparatus, the water temperature TZ of the heat exchanger for hot water supply is from the target temperature of 80 ° C. to the upper limit temperature of 90 ° C. when only the additional heating is performed. Is maintained near the range, so
If the hot water tap is opened in this state, a little too hot water will come out of the hot water tap (although the temperature will drop considerably in the piping leading up to the hot water tap), causing a discomfort to the user. There is.

In order to solve the above problems, a method of setting the target temperature with respect to the hot water supply heat exchanger temperature Tz to a temperature lower than 80 ° C. is conceivable, but in this case, the combustion amount of additional heating is Since it becomes smaller, there is a problem that the cooking time of the bath is delayed.

In view of the above-mentioned conventional problems, the present invention causes a discomfort to the user when the hot-water tap is opened in the one-can two-channel hot water supply device when only the additional heating is performed. The objective is to prevent hot water from coming out as much as possible, and to prevent the problem that the cooking time of the bath is delayed.

[0009]

The present invention relates to a hot water supply apparatus for heating a hot water heat exchanger for supplying hot water to a hot water tap and a hot water heat exchanger for additional heating of bath water by the same heating unit. , The heating amount of the heating unit is controlled according to the temperature condition that the water in the heat exchanger for hot water supply does not boil when only the hot water detection means for detecting the presence or absence of hot water from the hot water tap and the additional heating are performed independently. A heat quantity control means, a timer means for receiving the detection result of the hot water supply detection means and determining whether or not a predetermined time has elapsed from the stop of hot water supply, and before the predetermined time has elapsed, the temperature condition in the heat exchanger for hot water supply is set as the above temperature condition. The first temperature condition for maintaining the water temperature of the water is relatively low, while the second temperature condition for maintaining the water temperature in the hot water supply heat exchanger at a relatively high temperature after a predetermined time has passed. Select the selected first or second temperature condition to the heat quantity control unit. And having a temperature condition selection means for providing.

Here, as the heat quantity control means, for example, a feedback control for feeding back the water temperature of the heat exchanger for hot water supply and adjusting the heating quantity according to the degree to which the feedback value does not satisfy the temperature condition. A device can be employed. Alternatively, it is possible to employ an on / off control device that causes the water temperature in the hot water supply heat exchanger to satisfy the temperature condition by intermittently operating the heating unit.

[0011]

In the present invention, when hot water supply is stopped and only additional heating is performed, the heating amount of additional heating is adjusted under the temperature condition in which the water in the hot water supply heat exchanger does not boil. At that time, the first temperature condition that the water temperature in the heat exchanger for hot water supply is maintained at a relatively low temperature is used within a predetermined time after the hot water supply is stopped. A second temperature condition is used such that the water temperature in the heat exchanger is maintained at a relatively high temperature.

Generally, the frequency of restarting hot water supply after the hot water supply is stopped is high in the time period immediately after the hot water supply is stopped and becomes lower as time passes. The present invention pays attention to this fact, and there is a high possibility that hot water supply will be restarted before a lapse of a predetermined time (for example, 1 minute) from the hot water supply stop. Make sure the water temperature is not too high. On the other hand, after the lapse of a predetermined time, since there is little possibility of restarting hot water supply, the heating amount of the additional heating is increased to efficiently perform the additional heating.

As a result, by appropriately determining the predetermined time and temperature conditions, in many cases where hot water supply is restarted, unpleasant hot water does not come out and the efficiency of reheating can be maintained sufficiently high. Like

In the preferred embodiment, 1 minute is set as the predetermined time, and the first temperature condition is that the target temperature for the hot water heat exchanger temperature is 60 ° C. and the upper limit temperature is 80 ° C.
In addition, as the second temperature condition, the target temperature is set to 80 ° C and the upper limit temperature is set to 90 ° C.
Here, 1 minute is quite likely to restart hot water,
At the same time, the adverse effect on the efficiency of reheating can be ignored. In addition, the first temperature condition of 60 degrees Celsius, 8 degrees Celsius
If 0 ° is maintained in the hot water supply heat exchanger temperature within this range,
It can be expected that the hot water discharge temperature at the time of resuming hot water supply will be an appropriate temperature that is sufficiently acceptable for practical use. The second conditions of 80 ° C. and 90 ° C. are temperature values as high as possible in a range where water in the hot water heat exchanger does not boil,
The most efficient reheating can be expected.

As a method for controlling the amount of heat for additional heating, feedback control, on / off control, or the like can be adopted as described above. Feedback control has an advantage that fine control can be performed. On the other hand, the on / off control has an advantage that the processing load on the control device is reduced because it can be performed by a simple process.

In the preferred embodiment, feedback control and on / off control are used together. That is, the feedback control is used to control the hot water supply heat exchanger temperature to the target temperature, and the on / off control is used to prevent the upper limit temperature from being exceeded. Thereby, boiling can be effectively prevented.

[0017]

Embodiments of the present invention will be described below with reference to the drawings. 1 is a block diagram showing an entire configuration of an embodiment of a hot water supply device according to the present invention, FIG. 2 is a block diagram showing a functional configuration of a control circuit of the hot water supply device, and FIG. FIG. 4 is a block diagram shown, and FIG. 4 is a flow chart for explaining the operation of the control circuit of FIG.

First, the overall structure of the hot water supply apparatus according to this embodiment will be described with reference to FIG. In FIG. 1, during hot water supply or reheating, fuel gas passes through a gas proportional valve 1 and a burner 2
Since it is supplied to and burned, both the additional heating heat exchanger 3a and the hot water supply heat exchanger 3b are simultaneously heated with a combustion amount according to the opening degree of the proportional valve 1.

During reheating, the circulation pump 5 is operated, so that the water in the bathtub 4 is sent to the heat exchanger 3a for reheating to be heated and returned to the bathtub 4. At this time, the temperature of the hot water returning to the bathtub 4 (bath return temperature Tf) is detected by the temperature sensor.

During hot water supply, pressurized water from the water supply pipe is sent to the hot water supply heat exchanger 3b to be heated and supplied to the hot water supply tap 6. At this time, the water supply temperature Tc, the hot water temperature Tz of the hot water supply heat exchanger 3b, and the hot water supply temperature Tn are detected by the respective temperature sensors. At this time, the hot water supply amount Q is detected by the flow rate sensor.

The control circuit 11 is composed of, for example, a microcomputer, and inputs the bath return temperature Tf, the water supply temperature Tc, the hot water supply heat exchanger temperature Tz, the hot water supply temperature Tn, and the hot water supply amount Q from the various sensors described above. Hot water supply temperature TS, hot water supply temperature Tn from a remote controller (not shown)
, And the state of the additional heating switch. Then, as will be described in detail later, the control circuit 11 controls the opening degree of the proportional valve 1 (= combustion amount control of the burner 2) and the operation control of the circulation pump 5 based on those input signals.

Next, the configuration of the control circuit 10 will be described with reference to FIG.

When the hot water supply amount Q shows a significant value (= the hot water tap 6 is opened), the hot water supply heat amount calculation unit 11
Based on the hot water supply amount Q, the hot water supply set temperature TS, the hot water supply temperature Tc, and the hot water supply temperature Tn, the amount of heat required to produce hot water of the hot water supply set temperature TS is calculated.

When the reheating switch is turned on, the bath calorie calculation unit 14 determines the bath return temperature Tf, the bath set temperature Tfs, the hot water supply heat exchanger temperature Tz, and the hot water supply heat exchanger target temperature Tzs.
The amount of heat required for additional heating is calculated based on (described later) and the hot water supply heat exchanger upper limit temperature Tzm (described later).

The gas proportional valve control unit 12 receives the required heat amount from the hot water supply heat amount calculation unit 11 and the required heat amount from the bath heat amount calculation unit 14 calculated in this way, and the gas proportional valve drive unit 1
3, the opening of the gas proportional valve 1 is controlled, and the fan controller 15 controls the rotation of an intake / exhaust fan (not shown) via the fan driver 16.

The details of the function of the bath calorie calculator 14 are shown in FIG. That is, the two calorific value calculation units, that is, the calorific value calculation unit 14a for the bath alone and the feedback calculation unit 14b are provided. Then, the bath-independent-heat-amount calculating unit 14a always operates during heating, and calculates the required amount of heat only for optimum heating, that is, the bath return temperature T.
Calculate the amount of heat required to set f to the bath set temperature Tfs. On the other hand, the feedback calculation unit 14b operates only while only additional heating is performed, and the hot water supply heat exchanger 3 is operated.
The correction heat quantity for preventing the water in b from boiling is calculated, that is, the correction heat quantity for maintaining the hot water supply heat exchanger temperature Tz at the hot water supply heat exchanger target temperature Tzs (described later) is fed back. It is determined by PID (proportional + integral + derivative) calculation for the deviation between the hot water supply heat exchanger temperature Tz and the target temperature Tzs. Then, the added value of the heat amounts obtained by the two heat amount calculation units 14a and 14b is input to the on / off control unit 14c. The on / off control unit 14c
Hot water heat exchanger temperature Tz and hot water heat exchanger upper limit temperature Tzm
If Tz does not exceed Tzm, the added value of the heat amounts from the two heat amount calculation units 14a and 14b is output as the final required heating amount F, and when Tz exceeds Tzm. , A value that means that combustion is stopped is output as the final required heating amount F.

In the configuration of FIG. 3, the feedback calculation unit 14b is omitted, and the on / off control unit 14c comprehensively calculates the heat exchanger temperature Tz for hot water supply, its target temperature Tzs and its upper limit temperature Tzm. The combustion may be intermittently controlled so that the hot water supply heat exchanger temperature Tz is always maintained near the target temperature Tzs.

Now, referring again to FIG. 2, the first temperature storage unit 17a and the second temperature storage unit 17b respectively have a water heater heat exchanger target temperature Tzs and a hot water heat exchanger temperature T.
It stores a set of zm, and each stores a set of temperatures with different values. That is, the first target temperature (for example, 60 degrees Celsius) and the first upper limit temperature (for example, 80 degrees Celsius) are stored in the first temperature storage unit 17a as a set of relatively low temperatures. In addition, the second temperature storage unit 17b stores a second target temperature (for example, 80 degrees Celsius) and a second upper limit temperature (for example, 90 degrees Celsius) as a set of relatively high temperatures.

The hot-water supply / hot-fire execution determination unit 18 detects the hot-water supply and hot-fire operation states by monitoring the hot-water supply amount Q and the state of the hot-fire switch. And hot water supply amount Q
When the value decreases from a significant value to an insignificant value, the hot water supply / additional heating determination unit 18 determines that the hot water supply is stopped, and activates the timer 19 to measure the elapsed time after the hot water supply is stopped. Also,
While the additional heating switch is ON and the hot water supply amount Q shows a significant value, the hot water supply / additional heating determination unit 18 determines that hot water supply and additional heating are being performed at the same time, Stops the counting operation of the timer 19 and resets its counting value to zero.

When the timer 19 is started by stopping hot water supply as described above, the timer 19 performs a time counting operation only for a predetermined time (for example, 1 minute) at which hot water supply is likely to be restarted, and the time measurement of this predetermined time ends. Then, it stops the clock operation itself and resets the clock value to zero. Further, as described above, the timer 19 is forcibly stopped and the measured value is reset even during the simultaneous execution of hot water supply and additional heating. Therefore, timer 1
9 is 1 minute immediately after the hot water supply is stopped, and the time counting operation is performed only while hot water supply and reheating are not performed at the same time, and is stopped at other times.

The switching unit 20 monitors the state of the timer 19, and only while the timer 19 is performing the timekeeping operation, the first
The first target temperature (60 degrees Celsius) and the first upper limit temperature (80 degrees Celsius) stored in the temperature storage section 17a are selected, and otherwise stored in the second temperature storage section 17b. The second target temperature (80 degrees Celsius) and the second upper limit temperature (90 degrees Celsius) are selected, and the hot water heat exchanger target temperature T is selected.
It is passed to the bath heat amount calculation unit 14 as zs and the hot water supply heat exchanger upper limit temperature TzmT.

The pump control unit 21 drives the circulation pump 5 via the pump drive unit 22 only when the additional heating switch is in the ON state (= during additional heating).

Next, the operation of this embodiment will be described with reference to FIG.

First, when the hot water supply amount Q shows a significant value (= while hot water is being used) (step S21-YES),
Next, it is determined whether or not the additional heating switch is on (steps S21 → S22). Then, when the additional heating switch is ON, combustion is performed with a heat amount obtained by adding the necessary heat amounts of both hot water supply and additional heating, and the circulation pump 5 for additional heating is driven (step S23). On the other hand, when the additional heating switch is off, combustion is performed with the required amount of heat for hot water supply, and the circulation pump 5 is not driven at this time (step S24).

On the other hand, when it is determined in step S21 that the hot water supply is not in use, it is next determined whether or not the additional heating switch is on (step S25), and when the additional heating switch is off, combustion is performed. Without (step S26),
It returns to step S21. On the other hand, when the reheating switch is turned on in step S25, the circulation pump for reheating is driven and it is checked whether one minute has elapsed after the hot water supply was stopped (step S27). The result of this check is indicated by the state of the timer 19. That is, when the timer 19 is in the time counting operation, it means before 1 minute has elapsed, and when it is stopped, it means after 1 minute has elapsed. As described above, when hot water supply and reheating are being performed at the same time, even if one minute has elapsed after the hot water supply was stopped, it is treated in the same manner as after one minute has elapsed.

If it is determined in step S28 that one minute has not passed after the hot water supply was stopped, the control proceeds to step S29 and subsequent steps, in which the target temperature Tzs and the upper limit temperature Tzm of the hot water heat exchanger are low. First target temperature (6 degrees Celsius)
0 °) and a first upper temperature limit (80 ° C) are used. On the other hand, when it is determined that one minute has elapsed, the control proceeds to step S34 and thereafter, where the target temperature Tzs and the upper limit temperature Tzm are set to the higher second target temperature (80 degrees Celsius).
°) and a second upper temperature limit (90 ° C) are used.

In the control from step S29 onward before 1 minute has elapsed, it is first determined whether or not the hot water supply heat exchanger temperature TZ exceeds the upper limit temperature of 80 ° C. (step S2).
9) In the case of YES, the combustion is stopped, the rotational speed of the supply / exhaust fan is increased to positively perform cooling (step S30), and the process returns to step S21. On the other hand, step S
In the case of NO in 29, it is then determined whether or not the hot water supply heat exchanger temperature TZ exceeds the target temperature of 60 ° C. (step S31). After the start, or if the combustion is in progress, the combustion amount is increased (step S33), and the process returns to step S21. On the other hand, in step S31, 60 degrees Celsius
If it exceeds 0, the combustion state is continued to decrease the combustion amount (step S32), and the process returns to step S21.

On the other hand, step S34 after one minute has elapsed
In the following control, first, it is determined whether or not the hot water supply heat exchanger temperature TZ exceeds the upper limit temperature of 90 ° C. (step S34). If YES, the combustion is stopped and the supply / exhaust fan The number of rotations is increased to actively perform cooling (step S35), and the process returns to step S21. On the other hand,
In the case of NO in step S34, it is then determined whether or not the hot water supply heat exchanger temperature TZ exceeds the target temperature of 80 ° C. (step S36). If it does not exceed 80 ° C., If combustion is not in progress, combustion is started, or if combustion is in progress, the combustion amount is increased (step S38) and the process returns to step S21. On the other hand, if the temperature exceeds 80 degrees Celsius in step S36,
The combustion state is continued to reduce the combustion amount (step S3
7) and returns to step S21.

Incidentally, steps S32, S33, S37, S
The increase / decrease of the combustion amount at 38 is performed by the correction heat amount from the feedback calculation unit 14b shown in FIG. Further, the combustion stop / continuous loading selection based on the determination results in steps S29 and S34 is performed by the on / off control unit 14c shown in FIG.

According to the above-mentioned embodiment, when the hot water supply is stopped, it is empirically highly likely that the hot water supply will be restarted. , Heat exchange temperature TZ for hot water supply is relatively low from 80 ° C to 6 ° C
Since the combustion amount of additional heating is adjusted so as to be maintained in the range of 0 °, even if the hot water supply is restarted, hot water of a moderate temperature that is not hot will come out from the hot water tap. On the other hand, after 1 minute has passed since the hot water supply was stopped, which is unlikely to be restarted
When the heating operation is performed independently, the hot water heat exchanger temperature TZ is kept as high as possible within the range of 90 ° C. to 80 ° C. within the range where boiling does not occur. Can be done in time.

[0041]

[Effects of the Invention] When hot water supply is restarted during the additional heating operation,
In many cases, it is possible to solve the problem that unpleasant hot water comes out of the hot water tap while satisfying the requirement of not lowering the efficiency of reheating.

[Brief description of drawings]

FIG. 1 is a configuration diagram showing an entire embodiment of a hot water supply device according to the present invention.

FIG. 2 is a block diagram showing a functional configuration of a control circuit of the same embodiment.

FIG. 3 is a block diagram showing in detail the functional configuration of a bath heat amount calculation unit in FIG.

FIG. 4 is a flowchart for explaining the operation of the embodiment.

FIG. 5 is a flowchart for explaining the operation of the conventional hot water supply device.

[Explanation of symbols]

 1 Gas Proportional Valve 2 Heater 3a Reheating Heat Exchanger 3b Hot Water Heat Exchanger 5 Reheating Circulation Pump 6 Hot Water Stopper 10 Control Circuit 11 Hot Water Heater Calculation Unit 12 Gas Proportional Valve Control Unit 13 Gas Proportional Valve Drive Unit 14 Bath heat amount calculation unit 14a Bath alone heat amount calculation unit 14b Feedback calculation unit 14c ON / OFF control unit 17a First temperature storage unit 17b Second temperature storage unit 18 Hot water supply / reheating simultaneous use determination unit 19 Timer 20 Switching unit

Claims (3)

[Claims] 1. A hot water supply apparatus for heating a hot water supply heat exchanger for supplying hot water to a hot water supply tap and a reheating heat exchanger for additional heating of bath water by the same heating unit, wherein the hot water supply from the hot water supply tap is controlled. Hot water supply detection means for detecting the presence or absence, when performing only the additional heating alone, according to the temperature conditions such that the water in the hot water supply heat exchanger does not boil, heat quantity control means for controlling the heating amount of the heating unit, Receiving the detection result of the hot water supply detection means, a timer means for determining whether or not a predetermined time has elapsed from the stop of hot water supply, and before the predetermined time has elapsed, the temperature condition in the heat exchanger for hot water supply is set as the temperature condition. A first temperature condition for maintaining the water temperature at a relatively low temperature is selected, and a second temperature condition for maintaining the water temperature in the hot water supply heat exchanger at a relatively high temperature after the predetermined time has elapsed is selected. The selected first or second temperature condition. Water heater and having a temperature condition selecting means for providing the heat control unit. 2. The heat quantity control means has a feedback control means for adjusting the heating quantity according to the degree to which the feedback value of the water temperature of the hot water supply heat exchanger does not satisfy the temperature condition. Item 1. A water heater according to item 1. 3. The heat quantity control means has an on / off control means for making the water temperature in the hot water supply heat exchanger satisfy the temperature condition by intermittently operating the heating part. The hot water supply device according to claim 1.