JPH01118063A - Hot water supplying device - Google Patents

Abstract

PURPOSE:To perform a smooth changing-over operation under a safe combustion condition by a method wherein when a proportional control reaches near a maximum range of a semi- open capability control range, a changing-over solenoid valve is opened to be changed over to a full-open capability controlling range, and in turn when the proportional control reaches near a minimum range of a full-open capability control range, the changing-over solenoid valve is closed to be changed over to a semi-open capability control range. CONSTITUTION:When a gas proportional control reaches near a maximum range of a semi-open capability control range, it is stayed near a maximum range for a specified time after outputting a full-open changing-over signal, a gradual ignition current is supplied to a governor proportional valve 23, a changing-over valve 24 is turned ON and it is changed over to a full-open capability control range caused by a simultaneous combustion of the first and second burners 11a and 11b. When a gas proportional control reaches near a minimum range, it is stayed near a minimum range for a specified range after outputting a semi-open changing- over signal, a changing-over valve 24 is turned OFF and an amount of gas is automatically adjusted through a gas proportional control of a semi-open capability control range through a combustion of only the first burner 11a. An electric current for the governor proportional valve 23 corresponds to its most appropriate valve and a complete combustion state, and a changing-over control from a smooth semi-open state to a full-open or from a full-open state to a semi-open state can be performed.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention employs a feedback sub-door that automatically adjusts the amount of fuel supplied by calculating the required capacity based on the deviation between the set temperature and the hot water temperature. Related to water heaters.

[Prior Art] Japanese Utility Model Publication No. 60-16843 discloses a first burner connected to a fuel supply path through a proportional valve, and a second burner connected to the proportional valve through a switching solenoid valve. Half-open capacity control controlled by proportional control during half-open capacity operation by combustion of only the first burner!
ll range, a full open capacity control range controlled by proportional control during full open capacity operation by simultaneous combustion of the first burner and the second burner, a maximum range of half open capacity control 11Vt, and a minimum range of the full open capacity side tll range. A water heater is disclosed that has an overlapping Wt range.

[Problems to be Solved by the Invention] However, in the water heater having the above configuration, when increasing the combustion capacity from the maximum range of the half-open capacity control range I to the full-open capacity control range tIl, the temperature suddenly changes from the half-open capacity control IM to the full-open capacity control range. When switching to the control range or reducing the combustion capacity from the minimum range of the full-open capacity control range to the half-open capacity side TLL range, the combustion capacity is suddenly switched from the full-open capacity side iI range to the half-open capacity control range, and a safe combustion state is achieved. There was a problem that smooth switching control could not be performed.

The object of the present invention is to provide a water heater that is capable of achieving a safe combustion state and performing smooth switching control between wIg by half-open capacity and full-open capacity control O range.

[Means for Solving the Problems] The water heater of the present invention includes a fuel supply amount control means for adjusting the amount of fuel supplied, and a first fuel supply path connected to the fuel supply path via the fuel supply amount control means. a burner, and a second burner connected to the fuel supply amount control means via a switching solenoid valve, and a heat exchanger that is provided above the burner and heats water passing through the burner; a hot water outlet temperature detection means provided downstream of the heat exchanger and configured to detect the outlet temperature of the water flowing out from the heat exchanger, and a temperature for setting the outlet temperature of the water flowing out from the heat exchanger to a desired set temperature. a setting means, and a half-open capacity control range controlled by proportional control during half-open capacity operation by combustion of only the first burner, based on the deviation between the set temperature and the hot water temperature, and a half-open capacity control range controlled by proportional control;
During full-open capacity operation with simultaneous combustion of the burners, select the full-open capacity side WJ range controlled by proportional control and the overlapping control range of the maximum range of the half-open capacity control range and the minimum range of the full-open capacity control Il range, In the water heater, the water heater is equipped with a control circuit that opens and closes the switching solenoid valve according to the control range a, and also performs feedback control to automatically adjust the amount of fuel supplied. When the maximum capacity control area is reached, the switching solenoid valve is opened while performing slow ignition control to switch to the full-open capacity control area, and the proportional control is on the full-open capacity side! When reaching the vicinity of the minimum range of the Il range, the switching solenoid valve is closed and half-open capacity control tgt is applied.
We adopted a configuration that switches between

In the present invention, 174 half open includes not only fully open 172 but also other partial surfaces.

[Actions and Effects of the Invention] The water heater of the present invention has the following actions and effects due to the above configuration.

Based on the deviation between the set temperature and the hot water temperature, when operating at half-open capacity by burning only the first burner, the l1
During the half-open capacity control llI range, which is controlled by llll, and when the full-open capacity operation is performed by simultaneous combustion of the first burner and the second burner,
Full-open capacity control controlled by proportional control 1lIIit
and the overlapping control range W, which is the maximum range of the half-open capacity control range M and the minimum range during full-open capacity operation, and open and close the switching solenoid valve according to these control ranges, and control the amount of fuel supplied. When the proportional control reaches the maximum range of the half-open capacity control range, the switching solenoid valve is opened and switched to the full-open capacity control range while performing slow ignition control.
When the proportional control reaches the minimum range of the full-open capacity control range, the switching solenoid valve is closed and switched to the half-open capacity control range Il, thereby creating a safe combustion state and smooth half-open capacity control range I and full open capacity. It is possible to switch between the control area and the control area.

[Embodiment] In the present invention, an embodiment of a gas combustion type water heater using fuel gas as fuel will be described with reference to the drawings.

FIG. 1 shows a gas combustion type water heater employing an embodiment of the present invention.

A combustor case 10 is provided inside the water heater case 2 of the gas combustion type water heater 1, and a gas supply pipe 2 is further provided inside the combustor case 10.
A two-barrel gas burner 11 is provided, which consists of a first burner 11a and a second burner 11b that burn fuel gas supplied by the gas.

In addition, in the combustor case 10, a three-phase Y-connected Arasis D
A combustion fan 12 using a C motor is provided, and the gas burner 11 is a forced-air combustor that burns with combustion air supplied by the fan 12 and fuel gas supplied from a gas supply pipe 20. The combustion gas generated by combustion is exhausted to the outside from the exhaust port 3.

A heat exchanger 13 connected to a water supply pipe 30 is provided above the combustion case 10, and water passing through the interior is heated by the flame generated by the gas burner 11 and the heat of the combustion gas. Gas burner 11 inside combustor case 10
A sparker 14, which is an ignition device, and a flame rod 15, which is a flame detection means, are provided near the ignition device.

The gas supply pipe 20 includes a main solenoid valve 21, a main solenoid valve 22, which allows fuel gas to pass through when energized from the upstream side, and a fuel gas supply valve (hereinafter abbreviated as gas valve) that adjusts the supply pressure by adjusting the supply pressure. A governor-type gas proportional valve (hereinafter referred to as governor proportional valve) 23, which is a fuel supply control means, and a second burner 1
A switching electromagnetic valve (hereinafter abbreviated as a switching valve) 24 is provided to cut off fuel gas to 1b depending on the usage state, and supplies fuel gas to the gas burner 11 described above.

A drain plug 32 equipped with a water filter 31 is provided at the most upstream portion of the water supply pipe 30, and a heat exchanger 13 is provided downstream of the drain plug 32.
A water quantity proportional adjustment valve 33 using a geared motor is provided to adjust the amount of water entering the interior.
A potentiometer 34 is provided for detecting the degree.

The temperature of the water whose inflow amount has been adjusted by the water amount proportional adjustment valve 33 is detected by an inlet water temperature thermistor 35 which is an inlet water temperature detection means provided immediately downstream, and a water flow sensor which is a large water amount detection means provided immediately downstream. 36 detects the amount of water entering, and the water is sent to the heat exchanger 13 through the water supply pipe 30.

The water supply pipe 30 on the downstream side of the heat exchanger 13 is provided with a hot water temperature thermistor 38, which is a hot water temperature detection means for detecting the temperature of heated water. A stopper (not shown) is provided.

The water heater 1 having the above configuration is controlled by the control device 50.

As shown in FIG. 2, the control 11 device 50 includes a control circuit 60 connected to a power cord 51 connected to a wiring outlet, and a main controller 54 and a sub-controller 54a for remotely controlling the water heater 1. A terminal for connection and a gas type changeover switch 55 that is set according to the type of fuel gas are provided.

Types of fuel include LP gas and city gas 13A.

City gas 60 or the like is selectively switched by a gas type changeover switch 55.

Main controller 54 and sub controller 54a
is temperature setting means operated by the user, and in this embodiment, a main controller 54 is provided close to the water heater 1, and a sub-controller 54a is provided at a hot water supply location such as a bath. In addition, the main controller 54 and the sub-controller 54a are connected to each operation switch 5.
6.56a and water temperature setting switch 57 for setting the output temperature
．． 57a are provided.

The control circuit 60 includes a microcomputer (hereinafter referred to as CPU).
There are a sparker circuit 71, a fan drive circuit 72, a proportional valve control circuit 73, a geared motor drive circuit 74, a position detection circuit 75, and a water amount detection circuit 76, centered around a sparker circuit 70, which is controlled by the CPU 70. It will be done.

The fan drive circuit 72 rotates the fan 12 according to the combustion capacity such as the set temperature, detects the rotation speed using a Hall IC provided in a three-phase Y-connected brushless DC motor, and sends a detection signal to the CPU 70. In this embodiment, the rotational speed signals are particularly detected from all three phases of the motor to shorten the detection period.

The proportional valve control circuit 73 controls the amount of electricity supplied to the governor proportional valve 23 in order to adjust the amount of fuel gas supplied so that combustion in the gas burner 11 is performed at a desired air-fuel ratio. ) is a circuit that performs control based on a proportional control constant corresponding to The proportional valve control circuit 73 is a semi-fixed volume that proportionally controls the maximum value of the current to the governor proportional valve 23 in order to correct errors due to variations in the water heater 1 and pressure loss due to gas type to obtain an appropriate amount of gas. It is equipped with

The geared motor drive circuit 74 is a circuit that drives the geared motor of the water volume proportional adjustment valve 33 for regulating the amount of water flowing into the heat exchanger 13. It does not operate when the power is off, but when the power is on, the sub-controller 54a Regardless of whether the operation switch 56a is ON or OFF, it is set to the position of the previous set temperature, and from that position it is initially set to a position corresponding to the reference temperature.

The position detection circuit 75 is a circuit for analyzing the signal from the potentiometer 34 provided in the water volume proportional adjustment valve 33 to detect its opening degree.
Accurate control is achieved by using only the electrically effective portion of the entire rotation angle of the potentiometer 34 where changes in rotation appear as changes in resistance, and by reading the detected resistance value directly as the rotation angle. There is.

The water m detection circuit 76 detects the amount of water entering based on the rotational speed signal of the water amount sensor 36, and in this embodiment, the water m detection circuit 76 detects the amount of water entering the water m
By obtaining two new pulse signals from the rising timing and falling timing of the pulse signal from the sensor 36, the pulse repetition period can be shortened and the pulse width can be increased to reduce errors in F/V conversion. are doing.

The CPU 70 has a memory function that stores the reference temperature that is set in advance when the water heater 1 is assembled or shipped, and the type of fuel gas to be used, and the main controller 5.
4 and the sub-controller 54a;
Sequence control that controls the operating order and timing of each of the above circuits, feedforward control (hereinafter referred to as FF control) that controls the combustion amount and water input amount based on the input water temperature and set temperature as capacity control, and output control. Feedback control I (referred to as 12 lower PI system) performs proportional integral control II (referred to as 12 lower PI system) of the amount of fuel and water input, such as automatically adjusting the gas amount based on the temperature, turning on and off the switching valve 24, and adjusting the ffl amount of the fan 12. Below is the FB system t11 to call)) To, FF! 1il
llllt FB! 111111t! It performs switching control and also has safety functions.

The determination function is a part that analyzes pulse signals in order to perform control according to the respective setting states of the main controller 54 and the sub-controller 54a connected to the terminals 61 and 62 of the control circuit 60, respectively.
1 and terminal 62 are wire-saving two-wire terminals that can supply electricity to the main controller 54 and sub-controller 54a.

In the sequence control, when the user opens the hot water faucet and a water flow signal based on the water flow sensor 36 is obtained, the fan 12 is activated, and after pre-purging is performed for a predetermined period of time, the ignition operation is performed. In the ignition operation, the main solenoid valve 21, the main solenoid valve 22, the governor proportional valve 23, and the sparker 14 are energized at the same time, and after ignition is detected, the capacity of the combustion amount is calculated, and combustion begins according to the setting (2).

The sparker 14 is activated not only at the beginning of use, but also in the following cases where a misfire may occur during use, i.e., when the switching valve 24 is in the open state due to capacity control associated with the use of the dual-port gas burner 11. This is also carried out when the set temperature is changed and the current to the governor proportional valve 23 is reduced by, for example, 50% due to a change in the rotation speed of the fan 12.
Each operates for a predetermined time.

On the other hand, when a water flow signal is detected based on the water flow sensor 36, the combustion amount calculation starts simultaneously based on the inlet water temperature thermistor 35, but if the water temperature when water is not flowing through the water supply pipe 30 is read, the water temperature is correct. Therefore, in this embodiment, the water temperature is read by the inlet water temperature thermistor 35 after the water flow signal is detected, and the water temperature at that time is used as the water temperature data.

Capacity control uses FF control and combustion FF by detecting the hot water temperature.
FB (PI) control for correcting the i reading and the amount of water entering is performed.

The FF control is based on a calculated value Q of required capacity calculated from the set temperature, incoming water temperature, and amount of water input by the main controller 54 and sub-controller 54a, and a total required capacity PH1iq calculated from the incoming water temperature, amount of incoming water, and outlet temperature. The most efficient combustion capacity is calculated from the above, and the fan 12, the governor proportional valve 23, the switching valve 24, and the water volume proportional adjustment valve 33 are controlled, respectively, to automatically adjust the amount of gas and water input.

FF! ! 1ljll is controlled by the rapid heating capacity range (Q+α) controlled by the gas proportional division surface during rapid heating which outputs a capacity larger than the required capacity Q, and the gas proportional control during residual heat purge which outputs a capacity smaller than the required capacity Q. The fan 12, the governor proportional valve 23, the switching valve 24, and the water volume proportional adjustment valve 33 are each controlled according to the residual heat purge capacity range (Q-β), thereby automatically adjusting the gas amount and water input amount.

Further, the rapid heating capacity range (Q0α) is the maximum range of the half-open capacity control range controlled by gas proportional control during half-open capacity operation by combustion of only the first burner 11a, and
During full-open capacity operation due to simultaneous combustion of a and the second burner IH), full-open capacity control is differentiated by gas proportional control! I
Limited to areas that overlap with the minimum area of Area II. In particular, in this embodiment, as shown in the graph showing the relationship between the opening degree and the full opening capacity of the governor proportional valve 23 in FIG.
In the case of a water heater 1 having a governor proportional valve 23 that can throttle up to 100%, when the switching valve 24 is in the closed state, half-open capacity control 11aI performs gas proportional control of 178 to 1/2 of the full-open capacity using only the first burner T1a. and, when the switching valve 24 is in the open state, a full open capacity control region (2) in which gas proportional control of the full open capacity of 174 to 1 is performed on the first burner 11a and the second burner 211b;
Maximum III of half open capacity control range Il (172 of full open capacity)
An overlap limit mmmm between the maximum value and the minimum value of the full-open capacity control range (174 of the full-open capacity) is set.

FB! II 111], when the gas proportional control reaches the vicinity of the maximum range of the half-open capacity control area 11, the switching valve 24 is turned ON (open) while performing slow ignition sterilization, and the switch is switched to the full-open capacity control area I1. By the FB sub-control, when the gas proportional control reaches the vicinity of the minimum range of the full-open capacity control range ■, the switching valve 24 is set to 0FF (rIJi valve) and the half-open capacity control 11i is activated.
By switching to itI, a safe combustion state and smooth half-open capacity control (I) and full-open capacity control I can be achieved.
Performs switching control with area I.

As a safety feature, the temperature of the hot water is excellent! The temperature exceeds
If this continues for a predetermined time t8 (e.g. 1 to 10 seconds), if continuous combustion continues for t7 (e.g. 40 to 120) minutes, or if no flame is detected, each solenoid valve is closed and the operation is stopped. Stop.

The operation of the control device 50 of the water heater 1 of this embodiment will be explained based on the operation flowcharts shown in FIGS. 3 to 8.

When installing the water heater 1, the gas company or the distributor of the water heater 1 confirms the type of fuel gas to be used using the gas type selector switch 55, and also sets the reference temperature (40° C. in this example). (Sl).

The fuel gas type and reference temperature are not set by the user of the water heater, and are stored in the memory function of the CPU 70, so they are set regardless of whether the power is turned on or off.
Stored in U70. However, when the set temperature is input by the user, the CPU 70 prioritizes the set temperature over the reference temperature and controls the water heater 1 so that the hot water temperature approaches the set temperature.
control.

In order to use the water heater 1, the power cord 51 is connected to a wiring outlet and the power is turned on (Sl).

The water volume proportional control valve 33 has a reference temperature (40°C in this embodiment).
It is determined whether or not the insect-sized water inflow amount corresponding to the inflow amount is initially set to a severe opening degree (S3).

Here, the water volume proportional control valve 33 is controlled by the sub-controller 54.
Regardless of whether a is ON or OFF, the opening degree is set to the preset temperature (or standard @ degree) when the water heater 1 was used last time. However, with the Gisedo motor that changes the opening degree of the water volume proportional adjustment valve 33, if you try to adjust the opening degree after inputting the set temperature, the movement time requires several seconds, which may cut into the combustion regulation time. Combustion control is delayed. In order to prevent this, in this embodiment, the water amount proportional adjustment valve 33 is moved in advance before starting combustion.

Therefore, the adjustment time of the water volume proportional adjustment valve 33 from the initial setting to the opening corresponding to the set temperature during FF control (to be described later) is shortened, so the outlet hot water temperature can be set quickly during FF control. Temperature can be set.

When the opening degree is set to allow the maximum amount of water for the combustion capacity, the geared motor is turned off (S4).

When the opening degree is not set to allow maximum water entry, the geared motor is operated at 014 (S5). .

Normally, the driving time of the water layer proportional adjustment valve 33 is about a few seconds even when the maximum displacement occurs, but in the event of freezing or foreign matter, the water layer proportional adjustment valve 33 is locked, so the geared motor Even though the drive circuit 74 is energizing, the water volume proportional leak regulating valve 33 may not be displaced, and therefore the energization time is long and there is a risk of burnout due to heating of the remoter or geared motor drive circuit. In this embodiment, in order to prevent equipment failure even in such a case, the geared motor is turned off after the energization time by the geared motor drive circuit 74 is ti (for example, 5 to 30) seconds (S6). .

Next, it is determined whether or not the operating switch 56,56a of the main controller 54 or sub-controller 54a is turned on (S7), and step 87 is repeated until it is turned on. When turned on, the water temperature setting switch 57.57
Determine whether or not the hot water temperature is set by a (S8
).

In addition, if the hot water temperature is not set even after a predetermined period of time (t 2 seconds) has elapsed (S9), the set temperature is changed to 40% of the reference temperature.
℃ (S10). Next, when the user opens the hot water tap (S11), the amount of water entering is detected by the water amount sensor 36 (S12).

Here, when accepting the inflowing water amount change signal, a minute change that is not detected by the inflowing water amount detection circuit 76 is not accepted, and the amount of change in the inflowing water amount is greater than or equal to a predetermined value compared to the current amount of inflowing water (steady flow). Accept when.

Water amount detection circuit 76 that reads the signal from the water amount sensor 36
If the signal is higher than a predetermined voltage, it is detected as a water flow signal, but reading errors will occur in the water amount detection circuit 76 due to curvature, twisting, etc. of the water flow, and if the set voltage is kept constant, chattering will occur. , In this example, chattering is prevented by providing hysteresis characteristics,
The amount of water is 2.5j! /minute or more, it is detected as a water flow signal; 2. Oj! When there is a minute change of less than /min, it is not detected as a water flow signal.

Normally, the water inflow data is updated every sampling time, but taking into account the response delay of the water inflow sensor 36, the water inflow may also change if the cumulative value within a certain time exceeds a predetermined value. accepted as

Therefore, it is possible to detect not only an instantaneous change in the amount of water inflow, but also a change in the amount of water inflow within a certain period of time, and it is possible to adjust the gas amount in response to a wide range of changes in the amount of water inflow.

After detecting the amount of water entering, after a predetermined time (t3 seconds) has elapsed (S
13) The incoming water temperature is detected by the incoming water temperature thermistor 35 (314). Then, it is determined whether or not the incoming water temperature is 55°C or higher (815), and when the temperature is 55°C or higher, the user closes the hot water tap (816), and the operation switches 5θ, 56a of the main controller 54 and subcontroller 54a
517), determines whether the inlet water temperature is below the set temperature when the temperature is lower than 55°C (818), repeats the operation of Si2 or lower when the temperature is higher than the set temperature, and turns off the fan 12 when the temperature is below the set temperature. is turned on (S19).

The number of rotations of the fan 12 is detected by the Hall IC.
), determines whether the rotation speed is equal to or higher than a predetermined rotation speed (S
21). When the rotation speed is lower than the predetermined rotation speed, the rotation speed corresponding to the combustion capacity cannot be obtained, so the main solenoid valve 21, main solenoid valve 22, switching valve 24, governor proportional valve 23, and fan 12 are all set to 0FFt, (822 ~26), the user closes the hot water tap (S27), and then the operation switches 56 and 56 of the main controller 54 and sub-controller 54a
a is turned off (828).

When the rotational speed is equal to or higher than a predetermined rotational speed, t4 (for example, 0.
Pre-purge for 5 to 10) seconds (S29), turn on the sparker 14, the main solenoid valve 21, the main solenoid valve 22, and the switching valve 24, and supply slow ignition current to the governor proportional valve 23 (330 to 33). (S34).

As shown in FIG. 10, the amount of current applied to the governor proportional valve 23 depends on the rotation speed of the fan 12, that is, the air volume, and the type of gas Kp1. : Controlled based on In this embodiment, in particular, the amount of gas for slow ignition during ignition is made to be a constant ratio to the maximum value of the current to the governor proportional valve 23 adjusted by the semi-fixed volume of the proportional valve opening circuit 73. This makes it possible to supply an appropriate amount of slow ignition gas at the time of ignition.

Further, after t5 (for example, 5 to 20) seconds have elapsed after the sparker 14 was turned on (S35), the sparker 1
4 is turned off (S36). And frame rod 1
5 detects the combustion flame, and the flame rod 15 detects the I
Determine whether a current greater than or equal to
7). When a current of IA or more is not input, the operation of 822 and below is repeated as an ignition error.

When a current of IA or higher is input, a slow ignition timer for t6 (for example, 0.1 to 10) seconds is performed (338);
The outlet hot water temperature is detected by the outlet hot water temperature thermistor 38 (S39
).

Next, the combustion capacity control shown in the operation flowcharts of FIGS. 6 to 8 is performed (540), and the following safety function control is performed.

Determine whether the rotation speed of the fan 12 is equal to or higher than a predetermined rotation speed (
841). When the rotation speed is lower than a predetermined rotation speed, an operation of 322 or less is performed, and when the rotation speed is above a predetermined rotation speed, it is determined whether or not a current of IA or more is being inputted by the frame rod 15 (S42). [When a current of A or more is input, continuous combustion continues for t7 (for example, 40 to 120) minutes (843), or the temperature of the hot water exceeds the boiling temperature (844)
), if this continues for t8 (for example, 1 to 10) seconds (S45), the operations from 822 onwards are repeated. If the continuous combustion is within t7 minutes and the hot water temperature does not reach the wBm temperature, the set temperature is input again (846) lit
, 339 and subsequent operations are repeated. 346 deals with the case where the user changes the set temperature.

When a current of +A or more is not input, it is detected as a misfire such as blowing out, and it is difficult to determine whether or not this is the first misfire during combustion (547), and when it is the second misfire, the operations from 822 onwards are repeated. When a misfire occurs for the first time, the original solenoid valve 21, main solenoid valve 22, and switching valve 24 are set to 0FFL (848-50).
Thereafter, the operations from 819 onwards are repeated.

The combustion capacity control will be explained based on the operation flowcharts shown in FIGS. 6 to 8.

First, the required capacity for combustion capacity control is calculated based on the following formula (S1001, (3101)).

Formula 1...Calculated value Q= (Tset -THin)
xw formula 2... Calculated value Q - (THOut - THin
) xwTSet : Set temperature THin : Incoming water temperature THOtlt : Outgoing water temperature W : Incoming water amount FF! 5102),
When performing FF control, the FB (P
I) When performing control and not performing FF control, determine whether t9 seconds have passed after the initial setting (5103), t
After 9 seconds have elapsed, determine whether Q≧qx (31
04).

When Q≧qx is not, determine whether Q<Q or not.5105
), when Q<Q is not satisfied, in order to bring the outlet hot water temperature close to the set temperature, the fan 12, governor proportional valve 23, switching valve 24, and water volume proportional adjustment valve are installed so that the hot water is combusted with a sufficient heating capacity of QX 1.0. 33 (5106).

When Q<Q, the outlet hot water temperature is higher than the set temperature, so in order to bring the outlet hot water temperature closer to the set temperature, the fan 12 and governor are set so that combustion is performed with the minimum combustion capacity (residual heat purge capacity). The proportional valve 23, the switching valve 24, and the water volume proportional adjustment valve 33 are adjusted to 1 lil JIII (S107). τ+=
The fan 12, governor proportional valve 23, The switching valve 24 and the water quantity proportional adjustment valve 33 are immediately controlled (5110) and PIIIjlG is performed.

Here, when there is no light passing for τ1 second, the set temperature (T
The deviation 1 dtl between the hot water temperature (THout) and the hot water temperature (THout) is ±
Determine whether the temperature is within y℃ (8111) and calculate the deviation 1dt1
When the deviation is within ±y°C, step S110 is performed, and when the deviation 1dtl is not within ±y°C, step 3109 is performed again.

Since there may be errors due to variations in the water heater or a gas shortage where the gas pressure is lower than the standard value, the temperature detected by the outlet hot water temperature thermistor 38 will be The set temperature is not achieved Q≧
At the time of QX, the set temperature (Tset) and hot water temperature (THO
It is determined whether the deviation 1dtl from ut) is within ±y℃ (5112), and when the deviation 1dtl is within ±y℃, 510
6, and when the deviation 1d[1 is not within ±y℃, ((
The flan 12, the governor proportional valve 23, the switching valve 24, and the water amount proportional adjustment valve 33 are controlled so that combustion occurs with a rapid heating capacity of Q+α)/Q) (9113).

At this time, for example, the water volume proportional adjustment valve 33 is
Read the data entered in 70 and immediately set the set temperature tll (Tset)' and the hot water temperature (THout).
7) [The opening is narrowed down according to the difference 1dt1.

However, due to a change in the amount of water, the calculated value of combustion capacity is appealed, and if the combustion control is activated at this time, the change in gas amount and the change in the amount of water entering will interfere, and the temperature of the hot water will be affected, so the combustion with rapid heating ability will be maintained. By doing so, when changing the opening degree of the water volume proportional adjustment valve 33, the gas volume is not adjusted by controlling the ) 1 valve 12 and the governor proportional valve 23.

Here, it is determined whether or not the switching valve 24 is turned on (5114). When the switching valve 24 is turned on, that is, when the first burner 11a and the second burner 11b are operated at full capacity by simultaneous combustion, Half open capacity control 1tiilEI
5H5), and if it is not below the maximum range, the governor proportional valve 23 is gas proportionally controlled with the output within the overlap control tsatam (8116). .

When the switching valve 24 is not turned on, that is, during half-open capacity operation with combustion of only the first burner 11a, the minimum * of the full-open capacity control area O (1/4 capacity of the full-open capacity control area ■)
It is determined whether or not it is above the minimum range (step 3117), and if it is not above the minimum range, step 8116 is performed.

Therefore, the judgment level of the rapid heating capacity (Q + α) is half-open capacity control i (maximum range of I-area engineering or less − maximum range of half-open capacity control I-area engineering / ((Q + α) / Q), and full-open capacity control It is limited to the overlap control tl range (fixed value) which is greater than or equal to the minimum range of the capacity control range (■).As a result, the switching valve 24 is turned ON,
Chattering between full open and half open gas burner 11 that occurs when the gas burner 11 is turned off can be prevented, and the temperature control range can be expanded and the speed of rapid heating ability control can be increased at the same time.

Next, calculate τ2 = b - cw [seconds]3118), 1
After 2 seconds have elapsed (S119), the fan 12, governor proportional valve 23, switching valve 24, and water volume proportional adjustment valve 33 should be controlled so that combustion occurs with a residual heat purge capacity of (Q-β)/Q.
S120), and PI control is performed.

Here, if 12 seconds have not elapsed, the set temperature (T
The deviation between set) and output'fAtn (THout) is 1
Determine whether the temperature is within ±y℃ (S121)
, When the deviation 1dt1 is within ±y℃, perform 5120,
When the deviation 10 is not within ±y°C, it is determined whether or not there is a change in the outlet hot water temperature that is less than or equal to the temperature difference Δy in the predetermined time Δt (S122). When there is a change in the outlet S temperature equal to or less than Δy/Δ, step 5120 is performed, and when there is no change in the outlet hot water temperature equal to or less than Δy/Δ, the operations from 8119 onwards are repeated.

In Pllltlllltl, it is determined whether the deviation between the set temperature (TSet) and the hot water outlet temperature (T
Fan 1
2. Governor proportional valve 23, switching valve 24, water volume proportional adjustment valve 3
3 was controlled 8124), and t10 seconds elapsed (S12
5) After that, perform the safety control described above. Further, when tlo seconds have not elapsed, the operations from 8123 onwards are repeated.

When the deviation is not more than +7°C, calculate the integral time from the composite function of the temperature deviation function and the water entry function (S127)
.

Temperature deviation: e = set temperature - hot water temperature ,', F(e)=(K+e)xk.

In K, the constant water inflow W is a known quantity detected by the water sensor, ',
G (W)-(K2-e)Xk2, °, integration time:
T=to:+X (F(e)+G(W))=PI
Due to the proportional proportional control force time, the buried integral time [seconds] where the deviation between the set temperature and the hot water temperature is large is short, or the buried integral time where there is a large amount of water input is short,
The output time to the governor proportional valve 23 or the water volume proportional adjustment valve 33 becomes shorter.

After that, after T time has passed (3128), temperature deviation e≦
5129), when e≦1, the above-mentioned safety control is performed, and when e≦1, the gas type K of the fuel gas is determined.
3130), update the following PI control output so as to switch to the proportional sterilization constant according to the gas type Kp, and change the proportionality of the PI control output to the governor proportional valve 23 or water volume proportional adjustment valve 33. After outputting the control constant as a temperature deviation function (3 T31), safety control is performed.

PI proportional control control force PN -PN-1+exKp proportional output variation: ΔVS = eXKp pN-1=Q+α: Current PII example control output, ', P
I proportional control output PN = PN-1 + ΔVS However, when the amount of water entering is less than the predetermined primary color, the maximum value of the output is brought closer to (Q+α)/Q QX 1.0 to improve stability at minute flow rates.

Therefore, by switching to a proportional control constant according to the load such as gas type Kp, gas amount, and water inflow amount, the gas amount can be increased or decreased (not a fixed value but a variable), allowing for wide-range and free PI control. Sin can be done. Further, it is possible to perform P and I control that is compatible with the characteristics of the governor proportional valve 23 (which vary depending on the type of gas). Roughly speaking, from the integral time T and the PI ratio proportional control output, it is possible to bring the outlet hot water temperature closer to the set temperature quickly. Also, the gas type Kp of the fuel gas.

Alternatively, a predetermined amount of gas may not be obtained due to pressure loss in the gas supply pipe 20. In this case, the amount of current to be applied to the governor proportional valve 23 is changed from A1 to A2 for the minimum current during full-open capacity operation, and from 81 to 82 for the maximum current during half-open capacity operation, as shown in the graph of Fig. 10. is controlled so that a predetermined amount of gas is obtained.

Here, by the PI sub-control, when the following conditions are reached, a safe combustion condition and smooth control are achieved by switching the two-port gas burner 11 based on the operation flowchart shown in FIG. .

When the PN-1 proportional control is output, it is determined whether the switching valve 24 is turned on (8200), and the switching valve 24 is turned on.
When it is not in the state of N, that is, during half-open capacity operation with combustion of only the first burner 11a, the current to the governor proportional valve 23 is controlled by the gas proportional control of the half-open capacity control area I,
The gas amount is set to tlJvA (S201).

At this time, it is determined whether the gas proportional control section is near the maximum range of the half-open capacity 1tilIItl range (8202), and when it reaches near the maximum range, it outputs a full open switching signal (3203).

The full open switching signal uses a limit on the supply voltage to the fan 12 or the current value to the governor proportional valve 23.

A certain period of time 11 (e.g. 5~
(30 seconds) Gas proportional control remains near the maximum range of half-open capacity control 11jlEI (S204), (5205
), a gentle ignition current should be supplied to the governor proportional valve 23.
S206), turn on the switching valve 24 (S207),
Full-open capacity control is switched to region I by simultaneous combustion of the first burner 11a and second burner 11b, and full-open capacity control is 0.
The current to the governor proportional valve 23 is controlled by the gas proportional control in region (3), and the gas amount is automatically adjusted.

When the switching valve 24 is ON, that is, the first burner 1
During full-open capacity operation with simultaneous combustion of burners 1a and 2nd burner 1N), the current to the governor proportional valve 23 is controlled by gas proportional control in m range (3) according to full-open capacity, and the gas amount is automatically adjusted (3208).

At this time, the gas proportional control is on the fully open capacity side! It is determined whether or not the area is near the minimum area of the Ill area ■ (52091), and when the area is near the minimum area, a half-open switching signal is output (S210).

The half-open switching signal uses the supply voltage to the fan 12 or the current limit to the governor proportional valve 23.

A certain period of time 12 (e.g. 5~
30 seconds) When the gas proportional control remains near the minimum range of the fully open capacity m range (S211), (S212), the switching valve 24 is set to 0FFL (S213), and only the first burner 11a is The electric current to the governor proportional valve 23 is controlled by the gas proportional control of the half-open capacity control 1011 by combustion of the gas, and the gas amount is automatically adjusted.

At this time, the air volume of the fan 12 and the current to the governor proportional valve 23 each correspond to the optimum value, and are constant regardless of whether the gas burner 11 is fully open or half open.
Since the inertial force is large and there is a delay in response, the air volume of the fan 12 and the current to the governor proportional valve 23 are not changed. Therefore, a complete combustion state and smooth switching control from half-open to full-open or from full-open to half-open can be performed.

Further, each of the first burner 11a and the second burner 1
1b has a capacity limit, and depending on whether the other burner can cover the limit value, it may be controlled by switching the switching valve 24.
However, the method of detecting the 1;71 change signal using an instantaneous value may cause a chattering phenomenon in water heaters with a large heat capacity or with a delayed response, such as water heater 1. , which caused poor control. However, when the burner is switched to a predetermined burner when the burner is stopped in the off region 9 for a certain period of time as in this embodiment, chattering due to the ON/OFF switching of the switching valve 24 can be prevented.

In this embodiment, gaseous fuel such as fuel gas is used as the fuel, but liquid fuel such as petroleum may also be used as the fuel.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram showing a gas combustion water heater employing an embodiment of the present invention, FIG. 2 is a block diagram showing a gas jujube water heater employing an embodiment of the present invention, and FIG. 8 through 8 are operational flowcharts of a gas combustion water heater employing an embodiment of the present invention, and FIG. 9 is a Wpi diagram of a governor proportional valve for a gas combustion water heater employing an embodiment of the present invention.
Figure 10 is a graph showing the relationship between the current flowing to the governor proportional valve and the gas amount in a gas combustion type water heater employing an embodiment of the present invention. be. In the diagram 1... Gas combustion water heater 11... Gas burner 1
3... Heat exchanger 23... Governor proportional valve (fuel supply amount control means) 24... Solenoid valve for switching 38... Outlet hot water temperature thermistor (outlet hot water temperature detection means) 50... Control device
60... Control circuit 7o... Microcomputer (CPU) 73... Proportional valve control circuit

Claims (1)

[Scope of Claims] A fuel supply amount control means for adjusting the amount of fuel supplied, a first burner connected to a fuel supply path via the fuel supply amount control means, and switching to the fuel supply amount control means. a burner consisting of a second burner connected via a solenoid valve; a heat exchanger provided above the burner to heat water passing through the burner; and a heat exchanger provided downstream of the heat exchanger and configured to heat water passing through the burner; a hot water outlet temperature detection means for detecting the outlet temperature of the water flowing out from the heat exchanger; a temperature setting means for setting the outlet temperature of the water flowing out from the heat exchanger to a desired set temperature; and a temperature setting means for setting the outlet temperature of the water flowing out from the heat exchanger to a desired set temperature; Based on the deviation, there is a half-open capacity control range controlled by proportional control during half-open capacity operation with combustion of only the first burner, and a full-open capacity operation with simultaneous combustion of the first burner and second burner. At the time, a full-open capacity control range controlled by proportional control and an overlapping control range of the maximum range of the half-open capacity control range and the minimum range of the full-open capacity control range are selected, and the switching electromagnetic switch is controlled according to these control ranges. In a water heater equipped with a control circuit that opens and closes a valve and performs feedback control to automatically adjust the amount of fuel supplied, the feedback control causes the proportional control to reach near the maximum range of the half-open capacity control range. At this time, the switching solenoid valve is opened while performing slow ignition control and switched to the full open capacity control range, and when the proportional control reaches the vicinity of the minimum range of the full open capacity control range, the switching solenoid valve is closed and half opened. A water heater characterized by switching to a capacity control range.