JPH0252920A - Exhaust fan rotating speed controller for hot water supply apparatus - Google Patents

Abstract

PURPOSE:To supply air at an optimum flow rate during gas combustion by operating a fan motor according to a first set speed of low speed at igniting operation, and according to a second set speed of high speed after igniting operation. CONSTITUTION:When an operating switch 61 is turned on, a solenoid valve 45 is opened by a valve operating circuit 48, and sparks are generated by a spark generating circuit 49. When ignition is confirmed by a pilot lamp 41 that is lighted by a signal transmitted from a flame detecting circuit 51, ready- to-supply state of hot water is established. When water supply is confirmed by an output signal from a water flow detecting circuit 55, the first set speed of low speed most suitable for igniting a gas burner 2 is set and transmitted, and a motor 9 is operated at the first set speed. When a solenoid valve 33 is opened by a valve driving circuit 39, and combustion of the burner 2 is confirmed by an output signal from a flame detecting circuit 42, a second set speed most suitable for combustion of gas is set and transmitted to operate the motor 9 at the second set speed.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a rotation speed control device for an exhaust fan that forcibly exhausts exhaust gas from a water heater.

(Prior Art) Gas water heaters are known that are equipped with an exhaust fan that forcibly exhausts exhaust gas from a gas burner that heats water.

In such a gas water heater, the hot water tap is opened after the pilot burner is ignited, and as water is supplied into the water heater, the exhaust fan starts rotating, fuel gas is supplied to the gas burner, and ignition is performed. The exhaust fan starts rotating.

(Problem to be solved by the invention) The exhaust fan not only discharges exhaust gas but also supplies air to the gas burner. Conventionally, the rotational speed of the exhaust fan has been set so as to obtain the optimum air volume when burning fuel gas. It was set.

Therefore, when the gas burner is ignited, there is a problem in that the amount of air is excessive and the ignition performance is degraded.

The present invention was made in view of the current situation, and an object of the present invention is to provide a lid made by controlling the rotational speed of an exhaust fan that can obtain an optimal air volume during combustion of fuel gas and does not reduce ignition performance. shall be.

(Means for Solving the Problems) As a means for solving the above problems, the present invention, as shown in FIG. The flame detection means 3 detects ignition, and the first setting speed is set at a low speed when the water supply detection means 1 sends a water supply detection signal, and the second setting speed is set at a high speed when the flame detection means 3 sends a flame detection signal. It has a rotation speed setting means 5 for setting a set speed, a speed signal generation means 7 for transmitting a set speed signal based on these set speeds, and a motor of an exhaust fan 8 at a rotation speed based on the speed signal of the speed signal generation means 7. 9 and a motor drive means 11 for rotationally driving the exhaust fan rotation speed control device.

Further, as shown in FIG. 2, the speed generation signal means 7 is configured to set a time period for the rotational speed setting means 5 to shift the rotational speed from the first set speed to the second set speed in multiple stages based on a predetermined time function. A function generating means 13 may also be provided.

Furthermore, as shown in FIG. 3, it is provided with an exhaust temperature detection means 15 for detecting the exhaust gas temperature of the gas burner 2, and a speed signal generation means 7 is provided with a speed signal generation means 7 based on the temperature and time detected by the exhaust gas temperature detection means 15. The temperature-time function generating means 17 may be provided, which generates a function and uses the temperature-time function to cause the rotational speed setting means 5 to shift the rotational speed from the first set speed to the second set speed in multiple stages.

(Function) According to the above configuration, at the time of ignition, the fan 8
After ignition, the motor 9 is driven based on the high second set speed, so that air can be supplied at the optimum air volume when burning the gas, and the air volume can be prevented from becoming excessive when igniting. Can be effectively prevented.

In addition, since the optimal value of the air volume supplied to the gas burner changes depending on the temperature that gradually rises due to gas combustion, a sudden change in the rotational speed of the fan 8 from the first set speed to the second set speed will cause the gas burner to turn off. However, by providing the time function generating means 13 and changing the rotation speed in multiple stages from the first setting speed to the second setting speed, the rotation speed of the fan 8 can be gradually increased. By doing so, it is possible to effectively prevent the gas burner from turning off due to a sudden increase in air volume.

In addition, since the temperature rise due to combustion of gas changes depending on the external environment, by providing a temperature-time function generating means 17 that detects the actual temperature by the exhaust temperature detecting means 15 and changes the rotation speed based on this temperature and time. Furthermore, it is possible to more effectively respond to changes in the optimum value of the air volume supplied to the gas burner.

(Example) As a first example of the present invention, a gas water heater using an exhaust fan rotation speed control device configured as shown in FIG. 1 will be described below with reference to the accompanying drawings.

FIG. 4 is a block diagram showing the circuit configuration of the gas water heater according to the present invention. As shown in the figure, the gas water heater includes a gas burner 2, a combustion chamber 23 above the gas burner 2, and a combustion chamber 23.
3, an exhaust fan 8 installed in an exhaust pipe line 27 connected to the upper end of the combustion chamber 23, and a myratalocomputer 30 that controls the operation of these.

The gas burner 2 is arranged separately on a chamber 37 provided at the tip of a main gas pipe 35 in which a governor 31 and a solenoid valve 33 are arranged, and the solenoid valve 33 on the main gas pipe 35 is operated by a valve actuation circuit 39. Driven to open and close.

A thermocouple 40 and a pilot burner 41 are arranged near the gas burner 2 .

The thermocouple 45 generates an electromotive force upon ignition of the gas burner 2, and this electromotive force is converted into a signal by the flame detection circuit 42.

The pilot lamp 41 branches from the main gas pipe 35,
Branch gas pipe 47 equipped with a governor 43 and a solenoid valve 45
A solenoid valve 45 on the branch gas pipe 47 is driven to open and close by a valve operating circuit 48.

Further, the pilot burner 41 is ignited by a spark generated by a spark generation circuit 49 that includes a transformer 49a, and this ignition is confirmed by a detection signal from a flame detection circuit 51 that signals generation of an electromotive force by a thermocouple 50.

A water flow switch 53 is provided on the upstream side of the water supply pipe 25,
The on/off state of the water flow switch 53 is converted into a signal by the water supply detection circuit 55.

The exhaust fan 8 is fixed to the drive shaft of a motor 9, and the motor 9 is driven by a motor drive circuit 59.

The water heater also includes an activation switch 61.

Each of the above circuits is connected to the microcomputer 30, and is centrally controlled to supply hot water and stop the supply of hot water based on the on/off status of the operating switch 61. The operation of an example gas water heater will be explained.

FIG. 5 is a diagram showing the control of the microcomputer according to this embodiment. As shown in the figure, when the operation switch 61 is turned on (step 100), the solenoid valve 4
5 is opened by the valve actuation circuit 48 (step 101),
A spark is generated in the spark generation circuit 49 (step 102). Then, the ignition of the pilot lamp 41 is confirmed by generation of a detection signal from the flame detection circuit 51 (step 103), and the hot water supply becomes possible.

Thereafter, until the activation switch 61 is turned off (step 104), when water supply is confirmed by the output signal of the water flow detection circuit 55 (step 105), the first set speed is set to the low speed that is optimal for igniting the gas burner 2. is set (step 106), and then the first set speed is output (step 1
07), the motor drive circuit 59 drives the motor 9 at the first set speed. (Step 108).

Then, the solenoid valve 33 is opened by the valve operating circuit 39 (
Step 109), when ignition of the burner 2 is confirmed by the output signal of the flame detection circuit 42 (step 110),
The second set speed that is optimal for gas combustion is set (step 1).
11), the second set speed is output (step 112).
), the motor drive circuit 59 drives the motor 9 at the second set speed (step 113).

In the hot water supply state described above, when the stop of water supply is confirmed by the output signal of the water flow detection circuit 55 (step 114), the solenoid valve 33 is closed by the valve operating circuit 39 (step 115), and the motor drive circuit 59 9 is stopped (step 116), and the state returns to the hot water supply ready state.

Furthermore, when the operation switch 61 is turned off in the hot water supply enabled state (step 104), the solenoid valve 45 is closed by the valve operation circuit 48 (step 117).

Incidentally, steps 105 and 114 are applied to the water supply detection means 1, step 110 is applied to the ignition detection means 3, and step 106.11 is applied to the ignition detection means 3.
1 corresponds to the rotational speed setting means 5, steps 107 and 112 correspond to the speed signal generating means 7, and steps 108 and 113 correspond to the motor driving means 1, respectively.

According to the exhaust fan control device of this embodiment described above,
Since the rotational speed of the exhaust fan 9 is changed between ignition and gas combustion, it is possible to supply the optimal air volume to the gas burner 2 during gas combustion, and it is also possible to effectively prevent the air volume from becoming excessive during ignition. performance is improved.

Next, a gas water heater using the exhaust fan rotation speed control device having the configuration shown in FIG. 2 will be described with reference to FIGS. 4 and 6.

That is, as shown in FIG. 4, this embodiment is the same as the first embodiment except that the microcomputer 30 has a built-in timer 71, and a description of the similar parts will be omitted.

Here, the operation of the water heater of this embodiment will be explained with reference to FIG. 6, which shows the control of the microcomputer according to this embodiment. The operation of the water heater is the same except that after the second set speed is set, the motor is driven (step 113 in Figure 5) at the rotational speed set by the time function, and in Figure 6 the operation is the same. The part was omitted.

As shown in the figure, in the water heater of this embodiment, after the second set speed is set, the timer 71 is reset (step 113a), and then the time m of the timer 71 is read (step 113b).

Then, the time m is substituted into the number of time intervals f (m), the rotational speed R is calculated (step 113c), and then the rotational speed R is output (step 113d).

The time function f (m) indicates a gradual speed change over time from the first set speed to the second set speed,
A second set speed is given at time M.

Next, the motor 9 is driven based on the rotational speed R set by the time function f (m) (step 113e) m
Steps 113a to 113d are repeated until >M (step 113f).

Note that steps 113a, 113b, 113c and 113
f corresponds to the time function generating means 13, step 113d corresponds to the set rotational speed generating means 7, and step 113e corresponds to the motor driving means 11.

According to the exhaust fan rotation speed control device of the present embodiment described above, the rotation speed is multi-staged from the first set speed to the second set speed based on the time function f (m) generated by the time function generating means 13. It is possible to gradually increase the rotational speed of the fan 8 by setting the fan 8, and it is possible to effectively prevent the gas burner from turning off due to a sudden increase in air volume.

Next, a gas water heater using the exhaust fan rotation speed control device having the configuration shown in FIG. 3 will be described with reference to FIGS. 4 and 7.

That is, in this embodiment, as shown in FIG. 4, the microcomputer 30 has a built-in timer 71 and the exhaust pipe 27
The second embodiment is the same as the first embodiment except that a thermocouple 73 facing inside and a temperature detection circuit 75 for converting a change in electromotive force of the thermocouple into a signal are provided, and a description of the similar parts will be omitted.

Here, the operation of the water heater of this embodiment will be explained with reference to FIG. 7 showing the program of the microcomputer according to this embodiment. The operation of the water heater is the same except that after the second set speed is set, the motor is driven (step 113 in Figure 5) at a rotation speed based on the temperature/time function g (t, +n). , similar parts are omitted in FIG.

As shown in the figure, in the water heater of this embodiment, after the second set speed is set and the timer 71 is reset (step 113p), the temperature t is read from the output signal of the temperature detection circuit 73 (step 1113). and time m are read (step 1113).

Then, temperature t and time m are temperature-time function g (t, m
), and the rotational speed R is calculated (step 113
s), the rotational speed R is output (step 113t).
Ru.

The temperature/time number g (t, m) gives the temperature and time m the rotational speed that supplies the optimal air volume to the burner.

Next, the motor 9 is driven based on the rotation speed R set by the temperature time function g (t, m) (step 113u
) Steps 1132 to 113u are repeated until m>M (step 113v).

In addition, the temperature/time function g (t, m) is set to a function that uses only the temperature t as a variable after time m>M, and the time M
After , the motor 9 can be driven based on the rotational speed set by g (t).

Also, steps 113p and 113q.

113r, 113s, and 113v correspond to the temperature/time function generating means 17, step 113t corresponds to the set rotational speed generating means, and step 113u corresponds to the motor driving means 11.

According to the exhaust fan rotation speed control device of the present embodiment described above, the speed is changed from the first set speed to the second set speed based on the temperature/time function g (t, m) generated by the temperature/time function generating means 17. The rotational speed can be set in multiple stages, and as described above, it is possible to effectively prevent the gas burner from going out due to a sudden increase in air volume.

(Effects of the Invention) As detailed above, according to the present invention, the fan motor is driven based on the low first set speed at the time of ignition, and the fan motor is driven based on the high second set speed after ignition. As a result, it is possible to provide an exhaust fan rotation speed control device that provides an optimal air volume during fuel gas combustion and does not reduce ignition performance.

[Brief explanation of the drawing]

The attached FIGS. 1 to 3 are block diagrams showing the configuration of the present invention, FIG. 4 is a system diagram when the present invention is realized using a microcomputer, and FIGS. 5 to 7 are block diagrams showing the configuration of the present invention. 3 is a flowchart showing programs of first to third embodiments according to the present invention. In the drawings, 1 is a water supply detection means, 2 is a burner 3 is a flame detection means, 5 is a rotation speed setting means, 7 is a speed signal generation means, 8 is an exhaust fan, 9 is a motor, 11 is a motor drive means, and 13 is a Time function generating means 17 is temperature/time function generating means. Fig. 1 Fig. 2 Diversion number occurrence + counter

Claims (3)

[Claims] (1) A rotational speed control device for an exhaust fan that forcibly exhausts exhaust gas from a gas burner that heats water supplied to a water heater, comprising water supply detection means for detecting water supply to the water heater; flame detection means for detecting ignition of the gas burner after the water supply; setting a low first set speed when the water supply detection means transmits the water supply detection signal; and transmitting the flame detection signal from the flame detection means; a speed signal generating means for transmitting a set speed signal based on the set speed; and a speed signal generating means for transmitting a set speed signal based on the set speed; An exhaust fan rotation speed control device for a water heater, comprising: a motor driving means for rotationally driving a motor. (2) The speed signal generating means is characterized by comprising time function generating means that causes the rotational speed setting means to transition from the first set speed to the second set speed in multiple stages based on a predetermined time function. The exhaust fan rotation speed control device for a water heater according to claim 1. (3) An exhaust temperature detection means for detecting the exhaust gas temperature of the gas burner is provided, and the speed signal generation means generates a function based on the temperature and time detected by the exhaust temperature detection means, and the temperature time function Exhaust fan rotation speed control for a water heater according to claim 1, further comprising temperature time function generation means for setting the transition from the first set speed to the second set speed by the rotation speed setting means in multiple stages. Device.