JPH05240505A - Intermittent combustion type hot water storing hot water supplying apparatus - Google Patents

Abstract

PURPOSE:To provide an intermittent combustion type hot water storing hot water supplying apparatus in which a combustion amount fixed type burner is intermittently ignited to set the hot water temperature within the hot water storing tank by a temperature setting device and in which a range of variation of the hot water storing temperature and the hot water feeding-out temperature is set low. CONSTITUTION:An intermittent combustion control part 21 sets a combustion starting hot water temperature and a combustion terminating hot water temperature to the same degree of temperature to each other. It further prohibits the operation from transferring to the combustion stopping state during the period ranging from the combustion starting time to the combustion terminating and prohibiting time previously set. During the period ranging from the combustion stopping time to the time when the combustion starting prohibiting time elapses previously set, there is provided a combustion state changing-over restricting timer means 25 for prohibiting the transferring to the combustion state.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an intermittent combustion type hot water storage type hot water supply machine for intermittently burning a fixed burner type burner to keep hot water in a hot water storage tank at a hot water temperature set by a temperature setting device, and more particularly,
The hot water temperature at which combustion starts is prohibited by prohibiting the transition to the combustion stopped state until a predetermined time has elapsed from the start of combustion, and by prohibiting the transition to the combustion state until the predetermined time has elapsed after the combustion has stopped. And a hot water temperature at which combustion is stopped are set to substantially the same temperature to reduce fluctuations in hot water storage and hot water discharge temperatures.

[0002]

2. Description of the Related Art FIG. 11 is a schematic configuration diagram of a so-called semi-hot water type water heater having a hot water storage tank having a relatively small capacity (for example, a hot water storage amount of about 10 to 20 liters). In FIG. 11, a liquid fuel such as petroleum or kerosene is burned in a combustion chamber 2 a formed in the lower portion of the can body 2, and hot air passing through a hot water storage tank 3 equipped with a heat exchanger is exhausted through a muffling chamber 4 and an exhaust port 5. 1 shows a water heater 1 having a structure in which hot water in a hot water storage tank 3 is heated by being discharged to the outside. This water heater 1 includes an electromagnetic pump 7 for feeding liquid fuel to a burner nozzle 6 from a fuel tank (not shown), a fan motor 8 for blowing air, and a hot water such as a thermistor for detecting the hot water temperature in the hot water storage tank 3. Temperature detector 9, hot water temperature setting device 10,
In addition, the intermittent combustion control unit 11 is provided.

The intermittent combustion control unit 11 includes a hot water outlet temperature setting device 1
The signal 10a relating to the set temperature set at 0 is compared with the signal 9a relating to the hot water temperature output from the hot water temperature detector 9,
The operation of the electromagnetic pump 7 and the blower fan motor 8 is controlled, and intermittent combustion control is performed so that the hot water temperature in the hot water storage tank 3 approaches the set temperature. The water inlet 3 provided at the bottom of the hot water storage tank 3
A pressure reducing valve 1 is provided on a water supply pipe 12 for supplying tap water or the like to a.
3 is provided as needed, and a pressure relief valve 14 is also provided as needed.

A fuel main closing valve 16 is provided in the fuel supply pipe 15 in series with the electromagnetic pump 7. The can body 2 is provided with abnormal heating detection means 17 using bimetal or the like, and the intermittent combustion control unit 11 generates a fuel stop command 11b based on the abnormal heating detection signal 17a from the abnormal heating detection means 17. The fuel main closing valve 16 is controlled to be in a closed state, the fan operation command 11a is generated to perform forced air cooling, and further, an alarm or the like is generated as necessary.

In FIG. 11, reference numeral 18 is a combustion chamber, and reference numeral 19 is an ignition device. The ignition device 19 ignites the burner nozzle 6 based on an ignition command 11c supplied from the intermittent combustion control unit 11. It is configured as follows. The electromagnetic pump 7 supplies a predetermined flow rate of liquid fuel to the burner nozzle 6 based on the fuel supply command 11d supplied from the intermittent combustion control unit 11, and the amount of heat supplied by combustion is constant.

[0006]

In the conventional intermittent-heating type water heater, the combustion state is frequently switched between the combustion state and the combustion stop state by setting the combustion stop temperature about 2 ° C. higher than the combustion start temperature. Are prevented. As an example, a range of 2 ° C. to 3 ° C. is provided between the combustion start temperature Ton at which combustion starts and the combustion stop temperature Toff at which combustion is stopped. Temperature is 8
When the temperature exceeds 0 ° C, combustion is stopped and the detected hot water temperature is 77-
It is configured to start combustion when the temperature falls below 78 ° C. For this reason, a temperature fluctuation is caused by the difference between the combustion start temperature and the combustion stop temperature plus the amount of heating and supercooling caused by the delay of the combustion control system.

FIG. 12 and FIG. 13 are graphs showing hot water outlet temperature characteristics of a conventional hot water supply device. The vertical axis represents the hot water temperature and the horizontal axis represents the time. The hot water storage tank 3 has a capacity of 13.5 liters, the burner burns 500 Kcal per minute, and the feed water temperature is 10 ° C. Fig. 12 shows the tapping temperature change characteristics when the tapping temperature is set to 80 ° C and the tapping amount is 6 liters per minute. Fig. 13 is the tapping temperature when the tapping temperature is set to 45 ° C and the tapping amount is 10 liters per minute. The change characteristics are shown respectively. In addition,
The characteristics were measured at room temperature of 22 ° C.

Since the intermittent combustion control unit 11 performs the intermittent combustion control based on the hot water temperature in the hot water storage tank 3, the hot water temperature at which the combustion starts and stops and the above-mentioned combustion start temperature Ton.
In the graph of FIG. 12, there is a deviation of about 4 ° C. from the combustion stop temperature Toff, but even if the combustion is started at the time ton shown in FIG. 12, the outlet heated water temperature is about −10 ° C./20.
The tap water temperature is about +
The temperature starts to rise at a gradient of 10 ° C / 20 seconds, and the tap water temperature is about 7
Can body 2 even if combustion is stopped at time toff when it reaches 7 ° C
The temperature continues to rise for about 10 seconds and then drops due to the heat stored in the heat exchanger and the like. This is because the can body 2 and the hot water storage tank 3 have a predetermined thermal time constant, and therefore there is a relatively long time delay before the hot water temperature rises.

Therefore, in the conventional hot water supply device 1, when the amount of hot water discharged is large or the set temperature is high, the fluctuation range of the hot water discharge temperature becomes extremely large, and hot water of a desired temperature cannot be stably supplied. is there.

The present invention has been made to solve such a problem, and an object thereof is to bring the temperature difference between the combustion start temperature Ton and the combustion stop temperature Toff substantially close to zero, so that the fluctuation range of the outlet heated water temperature can be reduced. An object of the present invention is to provide an intermittent combustion type hot water storage type water heater having a small size.

[0011]

In order to solve the above problems, an intermittent combustion type hot water storage type hot water supply device according to the present invention is a burner of a fixed combustion amount based on the hot water temperature in a hot water storage tank detected by a hot water temperature detector. In a water heater provided with an intermittent combustion control unit that controls the hot water temperature in the hot water storage tank to approach a predetermined hot water temperature by intermittently burning the hot water temperature at which the intermittent combustion control unit starts combustion,
The hot water temperature to stop the combustion is set to substantially the same temperature, and the transition to the combustion stopped state is prohibited until the preset combustion stop prohibited time elapses from the time when the combustion is started, And / or Combustion state switching inhibition timer means for inhibiting transition to the combustion state from the time when the combustion is stopped until the preset combustion start inhibition time elapses.

The switching prohibition time may be set based on the set hot water temperature set by the hot water temperature setting device.

Further, each switching prohibition time may be set based on the difference between the set hot water temperature and the temperature of water entering the hot water storage tank.

Further, each switching prohibition time may be set based on the flow rate of hot water discharged per unit time.

Further, each switching prohibition time may be set based on the difference between the set hot water temperature and the water entering temperature into the hot water storage tank and the hot water discharge flow rate per unit time.

Further, a prohibition time correction means is provided for correcting each switching prohibition time based on the hot water temperature detected by the hot water temperature detector or the difference between the hot water temperature detected by the hot water temperature detector and the set hot water temperature. Good.

Even before the combustion stop inhibition time and the combustion start inhibition time elapse, if the hot water temperature in the hot water storage tank deviates from the preset temperature by the preset allowable temperature or more,
It is preferable that the combustion state switching inhibition timer unit is disabled and the combustion state switching permission unit that enables switching of the combustion state is provided.

[0018]

When the hot water in the hot water storage tank is heated by the combustion of the burner and reaches a predetermined combustion stop temperature, the intermittent combustion control unit stops the combustion. The combustion state switching inhibition timer means prohibits the transition to the combustion state from the time when the combustion is stopped until the combustion start inhibition time elapses. If the hot water temperature is below the combustion start temperature at the time when the combustion start prohibition time elapses, combustion starts immediately, and if the hot water temperature exceeds the combustion start temperature when the combustion start prohibition time elapses, the hot water temperature rises. Combustion starts when the temperature reaches the combustion start temperature. Combustion is continued from the time when new combustion is started until the combustion stop inhibition time elapses. If the hot water temperature is equal to or higher than the combustion stop temperature when the combustion stop inhibition time has elapsed, the combustion is stopped immediately, and if the hot water temperature has not reached the combustion stop temperature when the combustion stop inhibition time has elapsed, it reaches that temperature. Combustion continues until. Therefore, even if the combustion start temperature and the combustion stop temperature are set to the same temperature, the intermittent combustion control with the combustion start prohibition time and the combustion stop prohibition time as the shortest repeating cycle is performed, and fluctuations in the hot water storage temperature and the hot water discharge temperature are reduced. it can.

The combustion start prohibition time and combustion stop prohibition are based on the required heat quantity based on the set temperature, the difference between the set temperature and the incoming water temperature, the hot water flow rate, or the difference between the set temperature and the incoming water temperature and the hot water flow rate. By setting the time, effective temperature control can be performed according to the required combustion conditions, and it can be used over a wide range of tapping conditions such as low temperature to high temperature hot water and small flow rate to high flow rate hot water. It is possible to supply hot water with little temperature fluctuation.

Further, by providing the prohibited time correcting means,
If the hot water storage or hot water temperature is too high or low with respect to the set temperature in the currently set prohibition time, the fluctuation range of the hot water storage or hot water temperature can be suppressed by setting the prohibition time short again.

Furthermore, by providing the combustion state switching permission means for disabling the combustion state switching inhibition timer means and enabling the combustion state switching, the hot water storage or hot water temperature deviates significantly from the set temperature within the prohibited time. Can be prevented.

[0022]

Embodiments of the present invention will be described below with reference to the accompanying drawings. FIG. 1 is a block configuration diagram of an intermittent combustion control unit according to claims 1 and 2. The intermittent combustion control unit 21 performs the intermittent combustion control based on the set hot water temperature data 22a given from the hot water temperature setting device 22 and the hot water temperature signal 9a from the hot water temperature detector 9 shown in FIG. It is a thing. The intermittent combustion control unit 21 uses the signal 9a related to the hot water temperature.
Hot water temperature detection unit 23 for processing the detected hot water temperature data 23a, set hot water temperature data 22a and detected hot water temperature data 23a.
Based on the above, the start / stop judgment of the intermittent combustion is performed, and the combustion start / stop determination unit 24 that outputs the combustion start signal 24a and the combustion stop signal 24b, and the combustion state switching suppression that gives a time constraint on the transition of the combustion state Timer means 25
And the combustion stop signal 24a is set by the combustion start signal 24a.
A set-reset type flip-flop 26 reset by b, and a drive circuit 2 for operating the electromagnetic pump 7 or opening and closing the fuel main closing valve 16 based on the combustion command signal 26a supplied from the Q output terminal of this flip-flop.
It consists of 7.

The outlet hot water temperature setting device 22 is a circuit for outputting data 22a relating to the set hot water temperature in accordance with a set position or the like, and a multi-stage switch or a variable resistor having a knob or the like for setting the outlet hot water temperature. And so on.

The hot water temperature detection unit 23 includes a constant current source 23b for supplying a predetermined current to the hot water temperature detector 9 using a thermistor whose resistance value changes according to temperature, a DC amplifier 23c,
It is provided with an A / D converter 23d and an averaging processing means 23e. The DC amplifier 23c is configured to amplify the voltage signal 9a that changes according to the hot water temperature as necessary and shift the voltage level to a DC voltage range that can be handled by the A / D converter 23d. The A / D converter 23d samples the output voltage of the DC amplifier 23c for each preset sampling period, converts the sampled voltage into a corresponding digital signal, and outputs the digital signal.

The averaging processing means 23e is a temporary storage means such as a shift register for storing a plurality of A / D converted digital signals relating to the hot water temperature in chronological order and a plurality of storage means within a preset time range. And an arithmetic means for calculating and outputting the average value of the digital signal. As shown in FIGS. 5 and 11, in the case of the structure in which the hot water temperature detector 9 is installed on the inner wall surface of the hot water storage tank 3, hot water directly hits the hot water temperature detector 9 due to convection of the hot water when heating the hot water storage. Alternatively, when tapping hot water, cold water introduced from the water inlet 3a may directly hit the hot water temperature detector 9, and the hot water temperature signal 9a greatly fluctuates. Therefore, the averaging processing means 23e calculates the average value of the digital signals of, for example, 5 points excluding the signals of the maximum temperature and the minimum temperature from the digital signals of 7 points that are continuous in time series. , The calculation result is detected hot water temperature data 23a
As a result, it is configured to be supplied to the combustion start / stop determination unit 24.

By performing such an averaging process, restrictions on the mounting position of the hot water temperature detector 9 are reduced. Further, in order to prevent the detected hot water temperature from fluctuating due to the influence of water flow caused by convection or hot water discharge, the hot water temperature detector 9 is covered with a baffle plate or the like, or a thin tube is pulled out from the hot water storage tank 3 to detect the hot water temperature. The structural consideration of can be eliminated.

The combustion start / stop determination section 24 includes a combustion start temperature setting means 24c, a combustion start determination means 24d, a combustion stop temperature setting means 24e, and a combustion stop determination means 24f. The combustion start temperature setting means 24c and the combustion stop temperature setting means 24e calculate the combustion start temperature data 24g and the combustion stop temperature data 24h on the basis of the set hot water temperature data 22a set by the hot water temperature setting device 22. R for storing the combustion start temperature data and the combustion stop temperature data which are predetermined for each set hot water temperature.
It consists of OM.

The combustion start temperature setting means 24c and the combustion stop temperature setting means 24d use the arithmetic processing means to add or subtract the temperature data preset to the set hot water temperature data 22a to obtain the combustion start temperature. The data 24g and the combustion stop temperature data 24h may be output.

Here, the combustion start temperature data 24g and the combustion stop temperature data 24h have their temperatures set to substantially the same value. For example, for the set hot water temperature of 80 ° C., the combustion start temperature Ton is, for example, 80.2 ° C. and the combustion stop temperature To is
ff is set to, for example, 79.8 ° C. In the case of a configuration in which the hot water temperature in the hot water storage tank is indirectly detected from the outside of the can body, a temperature difference due to indirect detection, for example, 6 ° C. is corrected in advance,
The combustion start temperature Ton may be set to 74.2 ° C., and the combustion stop temperature Toff may be set to 73.8 ° C., for example. In addition,
The combustion start temperature Ton and the combustion stop temperature Toff may be set to exactly the same temperature. In this case, only one of the combustion start temperature setting means 24a and the combustion stop temperature setting means 24c is provided and the output data thereof is set. The configuration may be such that the determination means 24d and 24f are supplied.

Further, when the combustion start temperature Ton and the combustion stop temperature Toff are set to the same temperature as the set hot water temperature, the hot water temperature setting data 22a is detected directly or indirectly without providing the temperature setting means 24c and 24e. After the temperature difference due to is corrected, it is supplied to each of the determination means 24d and 24f.

The combustion start determining means 24d is provided in the hot water temperature detecting section 2
Detected hot water temperature data 2 output at a predetermined time interval from 3
3a and the combustion start temperature data 24e are compared, and the time when the detected hot water temperature becomes lower than the combustion start temperature Ton (when the temperature difference is provided between the combustion start temperature Ton and the combustion stop temperature Toff, the detected hot water temperature is detected). When the temperature becomes lower than the combustion start temperature Ton), the combustion start signal 24a having a predetermined pulse width is output. The combustion stop determination means 24f compares the detected hot water temperature data 23a output from the hot water temperature detector 23 at predetermined time intervals with the combustion stop temperature data 24h, and the detected hot water temperature becomes equal to or higher than the combustion stop temperature Toff. At the time point, the combustion start signal 24a having a predetermined pulse width is output.

The combustion start determination means 24d suspends the above-described determination operation while the combustion state inhibition timer means 25 supplies the H level combustion start determination prohibition signal 25a. Each temperature data 22a, 23 from the time when the inhibition signal 25a becomes L level, for example.
When the comparison of a is started and the combustion start condition is satisfied at that time, the combustion start signal 24a is immediately output.

Similarly, the combustion stop determination means 24f suspends the above-described determination operation while the combustion state inhibition timer means 25 supplies the combustion stop determination prohibition signal 25b of H level, for example, and the combustion stop determination is performed. Each temperature data 22a, 2 from the time when the judgment prohibiting signal 25b becomes L level, for example.
When the comparison of 3a is started and the combustion start condition is satisfied at that time, the combustion stop signal 24b is immediately output.

The judging means 24d and 24f constantly compare the set hot water temperature data 22a and the detected hot water temperature data 22a with each other by a comparison circuit such as a magnitude comparator, and use the judgment prohibition signals 25a and 25b. It may be configured to include gate means for controlling whether or not to output the comparison result based on the above.

The combustion state switching inhibition timer means 25 includes an inhibition time setting means 25c, a combustion stop inhibition timer 25d,
A combustion start prohibition timer 25e is provided.

The prohibition time setting means 25c is provided with a storage means such as a ROM for storing the combustion stop switching prohibition time data and the combustion start switching prohibition time data which are preset for each set hot water temperature. The combustion stop switching prohibition time data 25f corresponding to the set hot water temperature data 22a set in step 5 is set to the combustion stop prohibiting timer 25d, and the combustion start switching prohibition time data 25g corresponding to the set hot water temperature data 22a.
Are supplied to the combustion start prohibition timer 25e. Note that an average value may be used without the prohibition time data for each set hot water temperature.

The combustion stop prohibition timer 25d is provided with, for example, a program counter and a reference clock generating circuit, and from the time when the combustion start signal 24a is given until the time based on the combustion stop switching prohibition time data 25f elapses.
For example, the H-level combustion stop determination prohibition signal 25b is output. Similarly, the combustion start prohibition timer 25
d is, for example, an H level combustion start determination prohibition signal 25 from the time when the combustion stop signal 24b is given until the time based on the combustion start switching prohibition time data 25g elapses.
It is configured to output a.

When the combustion start switching prohibition time and the combustion stop switching prohibition time are set to the same value, the prohibition time data storage section 25c has one of the prohibition time data, and the prohibition time data is stored in each prohibition timer 25d. , 25e. When the switching prohibition time is set to a fixed time regardless of the set hot water temperature, the prohibition time data storage unit 2
The prohibit timers 25d and 25e may have a fixed time type configuration without providing 5c.

FIG. 2 is a waveform diagram showing the operation of the intermittent combustion controller of the water heater according to claims 1 and 2. FIG. 2 shows a case where the set hot water temperature is 80 ° C., the combustion stop temperature Toff is 80 ° C. or more, the combustion start temperature Ton is less than 80 ° C., the combustion start switching prohibition time and the combustion stop switching prohibition time are both set to 10 seconds. There is. FIG. 2A shows the detected hot water temperature 23a, and when the hot water discharge temperature reaches 80 ° C. due to combustion heating, the combustion stop determination means 24f outputs the combustion stop signal 24b shown in FIG. 2B. So, the Q of flip-flop 26
The output 26a is inverted from the combustion state (H level) to the combustion stop state (L level) as shown in FIG.
The combustion of the water heater 1 shown in is stopped.

The combustion start prohibition timer 25e supplies the H level combustion start switching prohibition signal 25a shown in FIG. 2C to the combustion start judgment means 24d based on the combustion stop signal 24b to prohibit the combustion start judgment operation. As a result, the detected hot water temperature 23a is affected by the convection in the hot water storage tank 3 and the water flow accompanying the hot water discharge.
As shown by the dotted line in (a), even if it changes below the combustion start temperature, it does not shift to the combustion state within the switching prohibition time.

When the detected hot water temperature 23a becomes lower than the combustion start temperature after the combustion start switching inhibition time has elapsed, the combustion start determination means 24d outputs the combustion start signal 24a shown in FIG. Q output 26a is inverted from the combustion stopped state (L level) to the combustion state (H level), and the combustion of water heater 1 is restarted. The combustion stop prohibition timer 25d is based on the combustion start signal 24a.
The H level combustion stop switching prohibition signal 25b shown in (e) is supplied to the combustion stop determination means 24f to prohibit the operation of determining the combustion stop. Therefore, the hot water detected due to the convection in the hot water tank 3 or the water flow associated with the hot water discharge. Even if the temperature 23a fluctuates above the combustion stop temperature as shown by the dotted line in FIG. 2A, the temperature does not shift to the combustion stop within the switching prohibition time.

Since the combustion state switching inhibition timer means 25 for prohibiting the transition of the combustion state until a predetermined time elapses after the transition to the new combustion state in this way, the combustion start temperature Ton and the combustion stop temperature Toff are provided. Even if the temperature difference between and is set to substantially zero, stable intermittent combustion control can be performed without frequent switching between the combustion state and the combustion stop state.

Further, by adopting a structure in which the combustion state switching prohibition time is changed according to the hot water temperature set by the hot water temperature setting device 22, hot water with a small temperature deviation can be supplied over a wide range of hot water temperature. it can.

FIG. 3 and FIG. 4 are graphs showing the outlet temperature characteristics of the water heater according to the first and second aspects. FIG. 3 shows the characteristics when the tapping temperature was set at 80 ° C. and the tapping temperature was 6 liters per minute, and FIG. 4 shows the characteristics when the tapping temperature was set at 45 ° C. and the tapping temperature was 10 liters per minute. As shown in FIGS. 12 and 13, in the conventional case, the variation range of the tap water temperature is 12 ° C. for the setting of 80 ° C. and 7 ° C. for the setting of 45 ° C. The range of change is 2-4 ° C for the setting of 80 ° C and 4〜 for the setting of 45 ° C
The temperature change width is as small as 5 ° C.

In this embodiment, the timer means 25 for suppressing the switching to both the combustion start and the combustion stop is shown, but the structure for suppressing only the transition to the combustion stop state, or the transition to the combustion state only. May be configured to be suppressed.

FIG. 5 is a schematic configuration diagram of a water heater according to claims 3 to 7. The water heater 31 has a water supply pipe 12 and a hot water storage tank 3
A water temperature detector 32 for detecting the incoming water temperature (supply water temperature) and a flow rate detector 33 for detecting the hot water discharge flow rate are provided as necessary. The flow rate detector 33 may be provided on the hot water outlet pipe 20 side.

FIG. 6 is a block diagram showing the prohibition time setting means according to the third aspect. The prohibited time setting means 35 according to claim 3 sets the set hot water temperature data 22a and the incoming water temperature data 35a.
Setting temperature / input water temperature difference calculation means 35c for outputting temperature difference data 35b, and ROM for storing combustion start switching prohibition time data 35f and combustion stop switching prohibition time data 35g set in advance for each temperature difference. And each prohibited time data 3 corresponding to the specified temperature difference data 35b
Prohibition time data storage means 35h for outputting 5f and 35g
Equipped with. The structure of the incoming water temperature detecting unit 35i is the same as that of the hot water temperature detecting unit 23 shown in FIG.

Since the prohibition time setting means 35 sets the switching prohibition time based on the temperature difference between the set hot water temperature and the incoming water temperature, even if the incoming water temperature greatly differs in summer and winter, for example, the change in hot water temperature is small. Stable hot water can be supplied.

FIG. 7 is a block diagram of prohibition time setting means according to claims 4 and 5. The prohibition time setting means 36 according to claim 4 and claim 5 uses the temperature difference data 35b output from the setting / incoming water temperature difference calculating means 35c.
And the flow rate data 36b output from the flow rate detector 36a
The switching prohibition time data 36f and 36g are set based on the above.

The prohibition time data storage means 36c stores the set data when the detected flow rate is zero, that is, in the hot water storage heat retention state,
The set data corresponding to the detected flow rate is stored corresponding to each temperature difference. When the flow rate detector 33 that outputs a pulse signal for each unit flow rate is used, the flow rate detection unit 36a is configured to output the flow rate data 36b in which the pulse period of the signal 33a related to the flow rate or the number of pulses within a predetermined time is detected. .. Note that each switching prohibition time may be set based on the product of the temperature difference data 35b and the flow rate data 36b (requested heat amount).

As described above, the prohibition time setting means 36 according to claims 4 and 5 can set the combustion state switching inhibition time in accordance with the flow rate of tapping hot water, that is, in accordance with the required amount of heat. It is possible to supply hot water with a small difference in tapping temperature depending on the conditions.

FIG. 8 is a block diagram showing the prohibition time setting means provided with the prohibition time correction means according to the sixth aspect. The prohibition time setting means 40 corrects each switching prohibition time based on the temperature deviation at the time of hot water discharge, and updates each switching prohibition time data.

The prohibition time setting means 40 is a hot water outlet temperature detector 41 provided on the hot water outlet pipe 20 of the water heater 31 shown in FIG.
A hot water temperature detector 42 that outputs hot water temperature data 42a based on a hot water temperature signal 41a output from
Hot water temperature deviation calculating means 43 and correcting means 44, 45 for correcting each switching inhibition time based on the temperature deviation data 43a.
And a prohibition time data updating means 46 and a prohibition time data storage means 47. The structure of the other parts is based on the prohibition time setting means 36 shown in FIG.

Hot water temperature detector 42 has the same structure as hot water temperature detector 23 shown in FIG. The set / outlet temperature deviation calculation means 43 calculates the set temperature data 22a and the outflow temperature data 4
The difference between 2a is obtained, and the temperature deviation data 43a including the polarity (positive / negative) is output.

The prohibition time data storage means 47 is composed of a RAM or a non-volatile ROM backed up by a battery or the like, and each preset prohibition time data is associated with the temperature difference data 35b and the flow rate data 36b. In addition, they are stored at the addresses designated by the respective data 35b and 36b. Further, when the combustion start switching prohibition time update data 47a or the combustion stop switching prohibition time update data 47b is supplied from the prohibition time data updating means 47, the prohibition time data storage means 47 updates the currently specified address. The data 47a and 47b are written.

The combustion start switching prohibition time correction means 44 determines the temporary start storage means such as a register for temporarily storing the combustion start switching prohibition time data 47a output from the prohibition time data storage means 47 and the combustion start determination prohibition signal 25a. A means for increasing or decreasing the combustion start switching prohibition time stored in the temporary storage means is provided based on the temperature deviation data 43a at the time of changing to the permission state (for example, at the time of changing from H level to L level).

That is, the combustion start switching prohibition time correction means 44 determines that the hot water discharge temperature is lower than the preset temperature by a preset threshold temperature or more (for example, 1 ° C. or more) when the combustion start inhibition timer 25e times out. (When the hot water temperature becomes too low), the combustion start switching prohibition time data 44a supplied to the combustion start prohibition timer 25e is set for a preset time (for example, a fixed value of 0.2 seconds or preset according to the temperature deviation). It is configured to reduce only the time).

Further, the combustion start switching prohibition time correction means 44 is provided when the hot water discharge temperature is higher than the preset temperature by a preset threshold temperature or more (for example, 1 ° C. or more) when the combustion start inhibition timer 25e times out. Is the combustion start switching prohibition time data 4 supplied to the combustion start prohibition timer 25e.
4a is configured to be increased by a preset time (for example, a fixed value of 0.2 seconds or a preset time according to the temperature deviation).

The combustion stop switching prohibition time correction means 45 determines the temporary stop means such as a register for temporarily storing the combustion stop switching prohibition time data 47b output from the prohibition time data storage means 47 and the combustion stop determination prohibition signal 25b. A means for increasing or decreasing the combustion start switching prohibition time stored in the temporary storage means is provided based on the temperature deviation data 43a at the time of changing to the permission state (for example, at the time of changing from H level to L level).

That is, the combustion stop switching prohibition time correction means 45 determines that the hot water discharge temperature is higher than the preset temperature by a preset threshold temperature or more (for example, 1 ° C. or more) when the combustion start inhibition timer 25e times out. Is (when the hot water temperature is too high), a preset time of the combustion start switching prohibition time data to be supplied to the combustion start prohibition timer 25e (for example, a fixed value of 0.2 seconds or a preset time according to the temperature deviation). ) Is configured to be shortened only.

Further, the combustion start switching prohibition time correction means 43a determines that the hot water outlet temperature is lower than the preset temperature by a preset threshold temperature or more (for example, 1 ° C. or more) when the combustion start inhibition timer 25e expires. Is configured to increase the combustion start switching prohibition time data supplied to the combustion start prohibition timer 25e by a preset time (for example, a fixed value of 0.2 seconds or a preset time according to the temperature deviation).

The prohibition time data updating means 46 is such that the temperature deviation 43a at the time when the combustion start prohibition timer 25e is up based on the change of the combustion start determination prohibition signal 25a is within a preset allowable value, and Until a predetermined time set in advance (or a predetermined number of combustion
When the corrected combustion start switching prohibition time data 44a does not change (or when the amount of change is within a predetermined value), the currently used combustion start switching prohibition time data 44a is set as the prohibition time data. The combustion start switching prohibition time update data 46a is supplied to the storage means 47,
It is configured to update the prohibited time data.

Similarly, the prohibited time data updating means 46 is
The temperature deviation 43a at the time when the combustion stop inhibition timer 25d times out based on the change of the combustion stop determination inhibition signal 25b is within a preset allowable value, and until a preset predetermined time elapses ( Alternatively, when the corrected combustion stop switching prohibition time data 45a does not change (or while the combustion / stop is repeated a predetermined number of times) (or when the amount of change is within a predetermined value), the combustion stop switching prohibition time currently used. The data 45a is supplied to the prohibition time data storage means 47 as the combustion stop switching prohibition time update data 46b to update the prohibition time data.

Since the water heater having the prohibition time correction means 44 and 45 according to claim 6 has the above-mentioned configuration, the optimum prohibition time is learned according to the usage condition, so that the intermittent combustion cycle is optimized. As a result, hot water can be supplied with little change in tapping temperature.

In FIG. 7, the structure for automatically correcting each prohibited time in the tapping state based on the deviation between the tapping temperature and the set temperature has been described. By performing similar processing based on the temperature deviation data between the hot water temperature detection data 23a and the set hot water temperature data 22a, which are the outputs, correction of each switching inhibition time data in the hot water storage heating state (state where the flow rate data is zero) In addition, the renewal can be performed, and the intermittent combustion cycle during hot water storage can be optimized.

FIG. 9 is a block diagram of an intermittent combustion control unit provided with the combustion state switching permission means according to the seventh aspect. The intermittent combustion control unit 50 according to claim 7 is provided with a combustion state switching permission unit 51 in addition to the intermittent combustion control unit 21 shown in FIG. This combustion state switching permission means 51
Is a switching permission determining means 52 and two AND gates 5.
It is composed of 3,54.

The switching permission determining means 52 compares the set hot water temperature data 22a with the detected hot water temperature data 23a, and if the detected hot water temperature is higher than the preset hot water temperature (for example, 3 ° C.), For example, L level combustion stop determination permission signal 5
2a is output to prevent the timer output 25b of the combustion stop inhibition timer 25d from being supplied to the combustion stop determination means 24f via the AND gate 53, so that the combustion stop determination can be performed. Similarly, when the detected hot water temperature is lower than the preset hot water temperature (for example, 3 ° C.),
For example, the combustion start determination permission signal 52b of L level is output, and the combustion start prohibition timer 25 is output via the AND gate 54.
The timer output 25a of e is prevented from being supplied to the combustion start determination means 24d so that the combustion start determination can be performed.

It is to be noted that a configuration in which the corresponding inhibition timers 25d and 25e are forcibly reset using the determination permission signals 52a and 52b, and the flip-flop 26 is preferentially set / reset based on the determination permission signals 52a and 52b. May be

As described above, by providing the combustion state switching permission means 51 for disabling the combustion state switching inhibition timer means 25 and enabling the combustion state switching, the hot water storage temperature or the hot water discharge temperature with respect to the set temperature is set within the prohibited time. It is possible to prevent a large shift.

Furthermore, the safety of the water heater can be improved by giving priority to the output of the combustion state switching permission means 51 over the determination result of the combustion start / stop determination unit 24 and performing the intermittent combustion control. ..

Although each functional block is shown independently in each block diagram, a microcomputer is used for the combustion start / stop determination unit 24, the combustion state switching inhibition timer unit 25, the combustion state switching permission unit 51, and the like. It may be configured by program control.

FIG. 10 is a block diagram showing another example of the structure of the intermittent combustion control unit according to claims 1 to 3. The intermittent combustion control unit 60 is configured by a relatively simple circuit without using a D / A converter or a microcomputer, and has a hot water temperature detection unit 61, an incoming water temperature detection unit 62, and start / stop of combustion. A voltage comparator 63 that makes a determination, a differential amplifier 64 that calculates the difference between the set hot water temperature and the incoming hot water temperature, a voltage control type timer circuit 65 that constitutes combustion state switching inhibition timer means, and a D type flip-flop 66. And a clock generation circuit 67, an AND gate 68, and a drive circuit 27.

Hot water temperature setting device 70 outputs a variable resistor 71 for setting the hot water temperature, resistors 72, 73 for setting the upper and lower limits of the set temperature, and a voltage 70a relating to the hot water temperature setting. And a buffer amplifier 74.

The hot water temperature detector 61 includes a constant current source 23b and a low pass filter (LPF) 61a for removing sharp changes in the hot water temperature signal 9a detected by the hot water temperature detector 9.
And a DC amplifier 61b, and a voltage 6 related to the detected hot water temperature.
1c is output. A low pass filter (LPF) 6
1a may be composed of an integrating circuit or a smoothing circuit having a predetermined time constant. The incoming water temperature detection unit 62 has the same configuration as the hot water temperature detection unit 61, and outputs a voltage 62c related to the incoming water temperature.

The voltage comparator 63 uses the voltage 6 related to the detected hot water temperature.
When 1c is 70a or less of the voltage related to the set hot water temperature, for example, L
The level logical output is configured to generate, for example, an H level logical output when the detected hot water temperature voltage 61c exceeds the set hot water temperature voltage 70a. The voltage comparison output (combustion start / stop determination output) 63a is supplied to the data (D) input terminal of the D-type flip-flop 66.

The differential amplifier 64 outputs a voltage 64a relating to the difference between the set hot water temperature and the incoming water temperature. The voltage 64a related to the temperature difference is supplied to the time setting input terminal 65a of the voltage control type timer circuit 65.

The voltage control type timer circuit 65 starts the timer operation based on the change of the logic level of the trigger input terminal 65b from H to L and from L to H, and the voltage supplied to the time setting input terminal 65a. The timer output 65c of L level, for example, is generated during the time determined based on.

The clock generation circuit 67 generates a clock 67a having a predetermined cycle (for example, several hundred milliseconds). The clock 67 a is supplied to the clock (C) input terminal of the D-type flip-flop 66 via the AND gate 68. Then, the Q output 66 of the D-type flip-flop 66
Based on a, the drive circuit 27 is used to control the operation / stop of the electromagnetic pump 7 to perform intermittent combustion.

Since the timer input 65c is supplied to the other input terminal of the AND gate 68, the set hot water temperature and the incoming water are supplied from the time when the Q output 66a of the D-type flip-flop 66 is inverted (the time when the combustion state is switched). The clock 67a is not supplied to the clock (C) input terminal of the D-type flip-flop 66 until the time set based on the voltage 64a relating to the temperature difference elapses. The voltage comparison output (combustion start / stop determination output) 63a cannot be taken in, and switching of the combustion state is suppressed.

[0080]

As described above, the water heater according to the first aspect of the invention is provided with the combustion state switching inhibiting timer means, so that even if the combustion start temperature and the combustion stop temperature are set to substantially the same temperature,
Intermittent combustion control is performed with the combustion start inhibition time and the combustion stop inhibition time as the shortest repetition cycle, and fluctuations in the hot water storage temperature and the hot water discharge temperature can be reduced.

The combustion start prohibition time and the combustion stop prohibition are based on the required heat quantity based on the set temperature, the difference between the set temperature and the incoming water temperature, the hot water discharge flow rate, or the difference between the set temperature and the incoming water temperature and the hot water discharge flow rate. By setting the time, effective temperature control can be performed according to the required combustion conditions, and it can be used over a wide range of tapping conditions such as low temperature to high temperature hot water and small flow rate to high flow rate hot water. It is possible to supply hot water with little temperature fluctuation.

Since the hot water supply device according to claim 6 is provided with the prohibition time correction means, the prohibition time is set when the hot water storage or hot water temperature becomes too high or too low with respect to the set temperature in the currently set prohibition time. It can be automatically reset, and the fluctuation range of the hot water storage or hot water discharge temperature can be suppressed.

Since the hot water supply apparatus according to the seventh aspect includes the combustion state switching permission means for disabling the combustion state switching inhibition timer means and switching the combustion state, the hot water storage or hot water temperature is set within the prohibited time with respect to the set temperature. It is possible to prevent a large shift.

[Brief description of drawings]

FIG. 1 is a block configuration diagram of an intermittent combustion control unit for a water heater according to claims 1 and 2.

FIG. 2 is a waveform diagram showing the operation of the intermittent combustion control unit of the water heater according to claims 1 and 2.

FIG. 3 is a graph showing tapping temperature characteristics of the hot water supply apparatus according to the present invention when tapping hot water at medium and high flow rates.

FIG. 4 is a graph showing tapping temperature characteristics of the hot water supply apparatus according to the present invention when tapping at low temperature and with a large flow rate.

FIG. 5 is a schematic configuration diagram of a water heater according to claims 3 to 6.

FIG. 6 is a block diagram of prohibition time setting means according to claim 3;

FIG. 7 is a block configuration diagram of prohibition time setting means according to claims 4 and 5.

FIG. 8 is a block configuration diagram of prohibition time setting means provided with prohibition time correction means according to claim 6;

FIG. 9 is a block configuration diagram of an intermittent combustion control unit including a combustion state switching permission unit according to claim 7.

FIG. 10 is a block configuration diagram showing another configuration example of the intermittent combustion control unit according to claims 1 to 3.

FIG. 11 is a schematic configuration diagram of a water heater according to the related art and claims 1 and 2.

FIG. 12 is a graph showing tapping temperature characteristics of a conventional hot water supply apparatus when tapping hot water at medium and high flow rates.

FIG. 13 is a graph showing tapping temperature characteristics of a conventional hot water supply apparatus at low temperature and large flow rate tapping.

[Explanation of symbols]

1, 31 ... Water heater, 9 ... Hot water temperature detector, 10, 22, 70
... Hot water temperature setting device 11, 21, 50, 60 ... Intermittent combustion control unit, 23, 61 ... Hot water temperature detection unit, 24 ... Combustion start / stop determination means, 25 ... Combustion state switching inhibition timer means, 26
c, 35, 36, 40 ... Prohibited time setting means, 32 ... Water temperature (inlet water temperature) detector, 33 ... Flow rate detector, 35c ... Setting /
Incoming water temperature difference calculating means, 35h, 35i, 62 ... Incoming water temperature detecting section, 47 ... Prohibition time data storing means, 36a ... Flow rate detecting section, 41 ... Outflow hot water temperature detector, 42 ... Outflow hot water temperature detecting section, 43
... setting / outlet temperature deviation calculation means, 44 ... combustion start switching prohibition time correction means, 45 ... combustion stop switching prohibition time correction means, 46 ... prohibition time data updating means, 63 ... combustion start
A voltage comparator that constitutes stop determination means, 64 ... a differential amplifier that calculates the difference between the set hot water temperature and the incoming water temperature, 65 ... a voltage control type timer circuit that constitutes combustion state switching prohibition timer means.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Hidekatsu Yamaguchi, 43-1, Uozakihama-cho, Higashinada-ku, Kobe City, Japan YUPRO Co., Ltd. (72) Inventor, Hiroshi Sawabashi 43-1, Uozakihama-cho, Higashinada-ku, Kobe Within Pro Co., Ltd.

Claims (7)

[Claims] 1. An intermittent control for intermittently combusting a burner of a fixed combustion amount based on the hot water temperature in the hot water storage tank detected by a hot water temperature detector so that the hot water temperature in the hot water storage tank approaches a predetermined hot water temperature. In an intermittent combustion type hot water storage type water heater with a combustion control unit,
The intermittent combustion control unit sets the hot water temperature at which combustion is started and the hot water temperature at which combustion is stopped at substantially the same temperature, and a preset combustion stop inhibition time elapses from the time when combustion is started. Combustion state switching that prohibits the transition to the combustion stop state until and / or prohibits the transition to the combustion state until the preset combustion start inhibition time elapses from the time when the combustion is stopped An intermittent combustion type hot water storage type water heater provided with a suppression timer means. 2. A prohibition time setting means for setting the combustion stop prohibition time, the combustion start prohibition time, or each switching prohibition time based on the set hot water temperature set by the hot water temperature setting device. The intermittent combustion type hot water storage type water heater according to claim 1. 3. A prohibition time setting means for setting the combustion stop prohibition time, the combustion start prohibition time, or each switching prohibition time based on the difference between the set hot water temperature and the water temperature entering the hot water storage tank. The intermittent combustion type hot water storage type hot water supply device according to claim 1, further comprising: 4. Based on the amount of hot water discharged per unit time,
The combustion stop prohibition time or the combustion start prohibition time,
2. The intermittent combustion type hot water storage type hot water supply apparatus according to claim 1, further comprising a prohibition time setting means for setting each switching prohibition time. 5. The combustion stop prohibition time or the combustion start prohibition time, or each switching prohibition time, based on the difference between the set hot water temperature and the incoming water temperature to the hot water storage tank and the hot water discharge flow rate per unit time. 2. The intermittent combustion type hot water storage type hot water supply apparatus according to claim 1, further comprising a prohibition time setting means for setting. 6. The combustion stop inhibition time or the combustion start inhibition time, or the combustion start inhibition time based on the difference between the hot water temperature detected by the hot water temperature detector or the hot water temperature detected by the hot water temperature detector and the preset hot water temperature, or 2. The intermittent combustion type hot water storage type hot water supply apparatus according to claim 1, further comprising a prohibition time correction means for correcting each switching prohibition time. 7. Even before the combustion stop prohibition time and the combustion start prohibition time have elapsed, if the hot water temperature in the hot water tank deviates from the preset temperature by a preset allowable temperature or more, The intermittent combustion type hot water storage type hot water supply apparatus according to claim 1, further comprising combustion state switching permission means for disabling the combustion state switching inhibition timer means to enable switching of combustion states.