JPH07111253B2 - Water heater - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a water heater having a control device including a microcomputer, and particularly to a controller having the same hardware configuration among a plurality of models having different hot water supply capabilities. The present invention relates to an improvement for making it available.

[Prior Art] Even though it is a conventional example, a recent hot water supply device has come to use a microcomputer for combustion control.
A fairly high degree of control is possible. In addition, some heat exchangers have a plurality of heat exchangers dedicated to heating the bath for hot water supply. As will be apparent from the following, the present invention is naturally applicable to such a device, but for the sake of understanding, in this section, a conventional hot water supply system having a relatively basic form is shown in FIG. I will explain immediately.

The illustrated water heater has a hot water heat exchanger 11 for tapping hot water from a hot water outlet 15 represented by one faucet 15 as needed.

Water from the water supply pipe is passed through the hot water supply heat exchanger 11 as indicated by the arrow "water" in the figure, and this water is heated by heating the heat exchanger 11 with the burner 12. Be warmed. Of course,
The burner 12 is supplied with fuel for combustion, but in the illustrated water heater, the most common gas is used as fuel. However, kerosene and other fuels may have almost the same structure as the hot water supply system, and if the gas is read as such other fuels, the following description of the present specification or the present invention can be applied as it is.

The gas from the gas pipe goes through the original solenoid valve 13, and then, based on a command from the microcomputer 20 simply described as a CPU, a dedicated gas flow rate control solenoid valve (so-called proportional valve) 14 on the hot water supply side makes it optimal at that time. Burner controlled by supply
The amount of air sent to the burner 12 is also controlled by the fan 19 based on the command from the microcomputer 20.

On the other hand, in order to perform the optimal combustion control as described above, the actual amount of water Q _H that passes through the heat exchanger 11 that is selectively heated by the burner 12 is detected by the flow rate sensor 16 and detected by the micro sensor. The temperature T _C of the water sent to the computer 20 and before entering the heat exchanger 11 is measured by the feed water temperature sensor 17,
Hot water temperature T _H from heat exchanger 11 is detected by hot water temperature sensor 18, and these temperature data T _C , T _H are also given to microcomputer 20.

Although not shown, whether or not the burner 12 has ignited as prescribed for safety, or the present burner, is not shown.
A flame detection sensor such as a flame rod to detect whether 12 is burning, or a high limit switch that detects this when the hot water temperature from the heat exchanger 11 becomes abnormally high. Further, in order to further enhance the controllability, a sensor or the like for detecting the air flow rate actually output by the fan 19 or the actual rotation speed and performing feedback control is incorporated as necessary.

However, even when performing control using such a microcomputer, even if the hardware configuration of the microcomputer is the same, depending on the hot water supply ability of the hot water represented by the so-called "number". In terms of software, that is, programs, basic data, etc. must be set according to the hot water supply capacity of each model.

By the way, most of the hot water supply capacity of existing water heaters is about 10 to 32 in terms of number, but that number is the heat exchanger.
Based on the flow rate Q _H passing through the heat exchanger 11, the water supply noise T _C , and the tap water temperature T _H under the condition that the heating burner 11 is maximally burned, the large output heat value FF is first set to FF = Q _H (T _H− T _C ) [Kcal / min]…, further reduce this to ⅕, and round the obtained value as appropriate.

Therefore, as a matter of course, if the numbers are different, the hot water outlet temperature T _H at the time of maximum combustion in the burner 12 changes even with the same heat exchanger passage flow rate Q _H and feed water temperature T _C , and the higher the number, the higher. vice versa,
If you want to keep the particular set temperature in the hot water temperature T _H is
The opening of the proportional valve 14 (or the current value given to it) that regulates the amount of gas given to the burner 12 and the amount of air supply (the number of fan revolutions) also differ, and at least with respect to the proportional valve opening, The bigger the water heater, the more narrow it will be compared to the smaller one.

In the past, however, was it necessary to prepare a dedicated control device from the hardware for each hot water heater of each number, or to prepare a dedicated program and data even if the hardware was almost the same? Alternatively, the control device is configured so that the target number can be changed between at least some different numbers by operating a switch, and when such a control device is actually installed in each water heater, the hot water supply is performed. The switch was mounted at the position of the number corresponding to the hot water supply capacity of the machine.

[Problems to be Solved by the Invention] However, when a control device having a dedicated hardware configuration is used according to the hot water supply capacity, that is the development of one type of control device for each hot water supply capacity, It was a great waste of production time and development resources.

On the other hand, in the case of a device in which a program or data for a built-in microcomputer is dedicated to each hot water supply capacity, although it can be rationalized a little, on the contrary, it may be indistinguishable only by looking at the hardware. Yes, there was still the risk of incorrect installation.

On the other hand, it is configured so that it can be applied to at least some types of models or hot water supply capacities, and depending on the hot water supply capacity of the actually installed water heater, it can be controlled by switching the switch at the time of mounting. The method of setting the target number of the device is superior to the other conventional methods described above, and it is rich in the diversion of the same control device between different models, but it is also manual switch operation at the time of mounting. Therefore, it was not possible to completely prevent erroneous switching.

Therefore, the present invention makes it possible to divert the same control device among at least some models, yet eliminates the risk of erroneous operation by humans when the control device is installed in each water heater, and the hot water supply capability of the installed model. According to the above, it was decided to automatically set the target number in the control device.

[Means for Solving the Problems] In order to achieve the above object, in the present invention, as an improvement in a water heater having a control device including a microcomputer, the hot water supply in which the microcomputer satisfies the following (a) to (c): Suggest a machine.

(A) An ignition operation is commanded to a burner that heats the heat exchanger by receiving a detection output of a water flow generation detection sensor that detects generation of a water flow of a predetermined flow rate or more passing through the heat exchanger.

(B) After the burner is ignited, the hot water supply capacity data calculation mode is entered, and under this hot water supply capacity data calculation mode, the fuel flow rate control valve provided in the fuel flow path to the burner is fixed at a predetermined valve opening and kept constant. Hot water temperature data obtained from the hot water temperature sensor that detects the hot water temperature discharged from the heat exchanger when the time has elapsed, and water temperature data obtained from the hot water temperature sensor that detects the temperature of the hot water supplied to the heat exchanger , And hot water supply capacity data representing the maximum output heat quantity value that can be obtained at the output of the heat exchanger, based on the flow rate data obtained from the flow rate sensor that detects the flow rate passing through the heat exchanger.

(C) After calculating the hot water supply capacity data, the normal control mode is entered, and under the normal control mode, the hot water supply capacity data calculated above, the water supply temperature data obtained from the water supply temperature sensor at each time, and the flow rate obtained from the flow rate sensor The valve opening of the fuel flow rate control valve at each time is controlled according to the data and the predetermined hot water temperature data.

However, in (b) above, the calculation of hot water supply capacity data is
It is "when a certain period of time has elapsed since the fuel flow rate control valve was fixed at a predetermined valve opening degree". However, in another aspect of the present invention, instead of this, the microcomputer performs "fuel flow rate control". When it is judged that the hot water temperature data obtained from the hot water temperature sensor that detects the hot water temperature discharged from the heat exchanger with the valve fixed at the predetermined valve opening is stable, The hot water supply capacity data may be calculated based on the water supply temperature data and the flow rate data.

Further, in any of the above cases, the microcomputer does not always enter the hot water supply capacity data calculation mode each time the burner is ignited, but as still another aspect of the present invention, the microcomputer (d) ignites the burner. Only when the command is the first command after the power is turned on to the microcomputer, the above hot water supply capacity data calculation mode is entered; (e) and is calculated as described above under the hot water supply capacity data calculation mode. (F) If the command for the ignition operation to the burner is not the first command after the microcomputer is powered on, the above-mentioned hot water supply capacity data storage mode is not performed. Enter the normal control mode; (g) Under the normal control mode, the hot water supply capacity data already stored in the above-mentioned storage means is read out. It is also proposed to use a hot water supply device characterized by using as calculated hot water supply capacity data.

[Operation] It can be said that there has been a water heater with a control device including a microcomputer that is compatible with water heaters with different hot water supply capacities. However, in such a conventional example, a switch operation was manually performed on the microcomputer. In contrast to the hot water supply capacity (number) of the target water heater to be controlled by the above, the microcomputer itself in the present invention calculates the hot water supply capacity data of the water heater incorporated therein, and thereafter Based on the combustion control. Therefore, not only is it time-consuming, but it is possible to escape from the fear of human error.

Further, according to a further lower aspect of the present invention, the hot water supply capacity data is obtained only with the first ignition operation after the controller is first powered on, and the once obtained hot water supply capacity data is stored in the storage means. , If the configuration that uses this stored data as long as the power is continuously turned on is adopted, it is not necessary to enter the hot water supply capacity data calculation mode each time the burner is ignited. Except for the first time (including), the other ignition times can quickly shift to normal control according to the hot water supply capacity of the water heater.

[Examples] Examples of the present invention will be described below with reference to FIG.
However, as long as the water heater to which the present invention is applicable or the water heater that can be improved by the present invention has the basic configuration shown in FIG. 2, most of the conventional structures are applicable.
In other words, even if a control mechanism for reheating and a heat exchanger dedicated to reheating are additionally provided, the second
As long as there is a heat exchanger for hot water supply as shown in the figure, the present invention can be applied.

Therefore, also in the embodiment of the present invention, the device configuration will be described with reference to the second illustrated one.

In the basic embodiment of the present invention, when a water flow passing through the heat exchanger 11 occurs as the user twists the faucet 15, etc., based on the data of the flow rate Q _H from the flow rate sensor 16, CP
A control device including a microcomputer 20 abbreviated as U detects the occurrence of the water flow, and at the beginning of each ignition time, which attempts to deliver the gas from the gas pipe through the original solenoid valve 13 to the burner 12. , The control device first enters the "hot water supply capacity data calculation mode" for knowing the hot water supply capacity data (maximum output heat quantity that can be output) of the water heater installed in the controller, and the proportional A constant current I _S is applied to the valve 14, the valve opening of the proportional valve 14 is set to a certain angle to supply a predetermined gas amount, and at the same time, the fan 19 also has a predetermined rotation speed according to the constant gas amount. Supply power to rotate at R _S.

When the burner is ignited by an ignition mechanism (not shown) in this state, a predetermined heat quantity F _I is given to the heat exchanger. This state is shown in FIG. ₁ as a time region from time t ₀ to determination time t ₁ described later.

Similarly, when a constant amount of heat F ₁ is applied to the heat exchanger 11 as shown in the portion after time t _{0 in} FIG. 1, the temperature of the water before entering the heat exchanger 11 at that time. depending on the T _C, hot water temperature T _H is detected by the hot water temperature sensor 18 starts to rise, eventually converges to a stable value that.

Therefore, as shown at time t ₁ in FIG. ₁ , a predetermined time from time t _{0 at} which the hot water temperature data is expected to be stable is set in advance, and the time at which the measurement is completed by using the microcomputer 20 is completed. t ₁ or actually hot water temperature T _H and monitoring (flow rate data in the time t ₁ determines that the value becomes substantially stable Q _H and water temperature data T _C by the microcomputer 20 is already stabilized before that It is usual that), each of these data Q _H , T _H , T _C is fetched into the microcomputer 20 and the operation of the above equation is performed.

The effective output heat value FF obtained as a result is the heat exchanger 11
Since the amount of heat applied to the water heater is known and constant, it changes according to the hot water supply capacity or number of the water heater, and falls within a certain range for each hot water supply capacity.

On the other hand, in the present invention, the range of the value FF expected at this time is given to the control device including the microcomputer 20 in advance for each hot water supply capacity. This can be achieved by the use of ROM or programmable memory by conventional techniques.

Therefore, the microcomputer 20 can compare the calculated FF value with a previously stored value range data group for each hot water supply ability, and thereby obtain the hot water supply ability of the water heater in which it is incorporated.

In this way, if it is possible to know the built-in hot water supply capacity data in the hot water supply capacity data calculation mode, this data can be transferred to a controlled object capacity switching part (change of program or data group) of the microcomputer 20 by a known method. Etc., including software and software changes), to enter the "normal control mode" in which the water heater can be used for normal use by the user after the hot water supply capacity determination time t1 in Fig. ₁ Therefore, the combustion control similar to that of the known combustion control of this type of existing water heater can be performed while effectively utilizing the maximum capacity of the water heater.

For example, under the normal control mode after the determination time t ₁ , each constraint at the constant values I _S and R _S during the determination period up to that time is released, and the water heater of this kind is supplied according to the flow rate Q _H at that time. follow the usual manner in the combustion control, to be changed control to an optimum value proportional valve current and fan speed, etc., as shown in a more schematic manner a time t ₂ later, the user changes the degree of opening of the faucet 15 When the flow rate changes due to the above, the maximum hot water supply capacity of the water heater can be effectively used, and the proportional valve current and the fan speed can be controlled to the optimum values.

Of course, although not shown, in the case where the user can set the desired hot water temperature (which is common these days), in order to keep the hot water temperature at the set temperature as much as possible, The control device can control combustion of the water heater.

However, the control device including the microcomputer used in the present invention needs to be designed and manufactured in advance so as to be compatible with at least two types of models having different hot water supply capacities in order to satisfy the above functions. There is. However, since the control device can know the hot water supply capacity of the built-in water heater after it is installed in the hot water supply machine, it is not necessary to manually change the hot water supply capacity according to the hot water supply capacity, and the manufacturer must be careful. Of course, it suffices to simply incorporate a control device that is common to all models in a plurality of model groups. You can escape from the risk of incorrect installation, so safety,
Reliability also increases.

Moreover, in reality, at least two or more types of control devices, which can cover most of the number ranges on the market, are simply used to run a microcomputer while the hardware configuration remains the same. It is also possible to realize it only by changing the contents of the program or the data group used. Therefore, based on such a reality, the effectiveness of the present invention becomes even more extreme.

Further, in the above-described embodiment, the determination of the hot water supply capacity is made for each ignition time. However, as another embodiment of the present invention,
It is possible to include the case where the above determination process is performed only in the first ignition time after the control device is powered on.

When the power is turned on for the first time, the water heater is first installed, the power plug is plugged into a commercial AC power outlet, the power is restored after a power failure, etc. The hot water supply capacity data calculation mode is entered only at the first ignition after the power is turned on, and the hot water supply capacity data obtained under the mode is stored in the volatile memory attached to the microcomputer until the power is turned off. Since the control device can perform combustion control based on the same hot water supply capacity data, compared with the case where the hot water supply capacity data is recalculated for each ignition, of course, for example, to bring the hot water supply temperature to the set temperature. The control of is faster in time.

Furthermore, if at least an electrically writable, preferably rewritable, non-volatile memory is used, it is possible to obtain hot water supply capacity data according to the above only at the first ignition time when the power is first turned on after the hot water supply is installed. By storing this in this non-volatile memory, even if the power supply is interrupted once, for example, due to a power failure or the plugging / unplugging of the power supply plug, the memory contents are read out after the recovery, and the calculation is performed again. No processing is required.

In FIG. 1, during the hot water supply capacity determination period from time t ₀ to time t _1, it is possible to adopt a device configuration in which the flow rate Q _H is also constantly throttled by a flow rate valve (not shown). Then, as is clear from the above equation, the calculation itself for obtaining the hot water supply capacity data is actually only the difference calculation between the hot water supply temperature T _H and the water supply temperature T _C , which simplifies further.

[Effect] According to the present invention, the control device incorporated in the hot water supply apparatus determines the hot water supply capacity of the hot water supply apparatus by itself and performs subsequent combustion control based on the determined hot water supply capacity data. The user does not have to intervene in that determination at all.

Therefore, as in the past, when incorporating into a control device that performs combustion control according to each hot water supply capacity for multiple types of hot water supply machines with different hot water supply capabilities, the hardware-specific device configuration itself provides a dedicated control for each model. There is no irrational need to prepare the device, and conversely even though it is common in hardware, it is necessary to provide a switch manually because it is intended to be used between multiple models, which may cause erroneous operation. However, the appearance of the device does not change, so there is no concern about mis-installing the control device for each type, and the manufacturing process is dramatically simplified and rationalized, and the safety and reliability of the water heater are improved.

Moreover, the present invention can be embodied immediately even in the existing device configuration, and does not require any special member.

[Brief description of drawings]

FIG. 1 is an explanatory view for explaining one embodiment of the present invention according to the state of each part at the time of hot water supply capacity determination, and FIG. 2 is an explanatory view of a basic component part of a hot water supply device to which the present invention can be applied. In the figure, 11 is a heat exchanger, 12 is a burner, 13 is a solenoid valve, 14 is a proportional valve, 15 is a hot water outlet, 16 is a flow sensor, 17 is a water temperature sensor, 18 is a hot water temperature sensor, 19 is a fan, Twenty is a microcomputer.

Continuation of the front page (56) Reference JP-A-59-221518 (JP, A) JP-A-2-171903 (JP, A) JP-A-2-123408 (JP, A) Actual development Sho-60-176344 (JP , U)

Claims (4)

[Claims] 1. A water heater having a control device including a microcomputer; the microcomputer comprising: (a) detection of a water flow generation detection sensor for detecting generation of a water flow exceeding a predetermined flow rate passing through the heat exchanger. In response to the output, the burner that heats the heat exchanger is commanded to perform an ignition operation; (b) After the burner is ignited, the hot water supply capacity data calculation mode is entered, and under the hot water supply capacity data calculation mode, the fuel flow to the burner is started. The fuel flow rate control valve provided in the passage is fixed to a predetermined valve opening degree, and when a fixed time elapses while the valve opening degree is fixed,
Hot water temperature data obtained from a hot water temperature sensor that detects the hot water temperature discharged from the heat exchanger, water temperature data obtained from a hot water temperature sensor that detects the temperature of the hot water supplied to the heat exchanger, and Based on the flow rate data obtained from the flow rate sensor that detects the flow rate passing through the heat exchanger, hot water supply capacity data representing the maximum output heat quantity value that can be obtained at the output of the heat exchanger is calculated; (c) the hot water supply capacity After the data calculation, the normal control mode is entered, and under the normal control mode, the calculated hot water supply capacity data, the water supply temperature data obtained from the water supply temperature sensor at each time, the flow rate data obtained from the flow rate sensor, and the predetermined value Controlling the opening degree of the fuel flow rate control valve at each time in accordance with the hot water discharge temperature data of the hot water supply apparatus. 2. The water heater according to claim 1, wherein: in the microcomputer, (d) the instruction of the ignition operation to the burner is the first instruction after the microcomputer is powered on. (E) and stores the calculated hot water supply capacity data in the storage means in the hot water supply capacity data calculation mode, and (f) ignites the burner. Command is not the first command when the microcomputer is powered on, the normal control mode is entered without going through the hot water supply capacity data calculation mode; (g) Under the normal control mode, Reading the hot water supply capacity data stored in the storage means and using it as the calculated hot water supply capacity data; 3. A water heater having a control device including a microcomputer, wherein the microcomputer comprises: (a) detection of a water flow generation detection sensor for detecting generation of a water flow of a predetermined flow rate or more passing through the heat exchanger. In response to the output, the burner that heats the heat exchanger is commanded to perform an ignition operation; (b) After the burner is ignited, the hot water supply capacity data calculation mode is entered, and under the hot water supply capacity data calculation mode, the fuel flow to the burner is started. The fuel flow rate control valve provided in the passage is fixed to a predetermined valve opening, and the hot water temperature data obtained from the hot water temperature sensor that detects the hot water temperature discharged from the heat exchanger with the valve opening fixed is obtained. When it is judged to be stable, the hot water temperature data, the water temperature data obtained from a water temperature sensor for detecting the temperature of the water supplied to the heat exchanger, and the flow rate passing through the heat exchanger are detected. Based on the flow rate data obtained from the quantity sensor, calculate hot water supply capacity data representing the maximum output heat quantity value that can be obtained at the output of the heat exchanger; (c) After calculating the hot water supply capacity data, enter the normal control mode, Under the normal control mode, the fuel is supplied in accordance with the calculated hot water supply capacity data, the water supply temperature data obtained from the water supply temperature sensor at each time, the flow rate data obtained from the flow rate sensor, and the predetermined hot water temperature data. Controlling the opening degree of the flow control valve at any given time; 4. The water heater according to claim 3, wherein: in the microcomputer, (d) the command for the ignition operation to the burner is the first command after the microcomputer is powered on. (E) and stores the calculated hot water supply capacity data in the storage means in the hot water supply capacity data calculation mode, and (f) ignites the burner. Command is not the first command when the microcomputer is powered on, the normal control mode is entered without going through the hot water supply capacity data calculation mode; (g) Under the normal control mode, Reading the hot water supply capacity data stored in the storage means and using it as the calculated hot water supply capacity data;