TWI669465B - Gas appliance and its control method - Google Patents

Abstract

A gas appliance comprises a burner, a gas valve, an igniter, a thermocouple and a control device, wherein the control device is configured to perform a control method comprising the steps of: controlling ignition of the igniter and opening of the gas valve; receiving the output of the thermocouple The detection voltage; when the detection voltage rises to a first voltage value, the ignition of the igniter is stopped and the gas circuit of the gas valve is opened; D, the detection voltage of the thermocouple output is continuously received, and the detection voltage is high The control gas valve blocks the gas line when the second voltage value falls below the second voltage value, wherein the second voltage value is higher than the first voltage value. This speeds up the ignition process and blocks the gas early in the event of a flameout.

Description

Gas appliance and its control method

The present invention relates to gas appliances; in particular, to a gas appliance that uses a thermocouple to detect a flame.

Gas appliances are most commonly used in heating devices. Compared with electrothermal heating devices, the heat energy generated by burning gas is greater than the heat energy generated by using electricity, and the heating time and reaction time are faster than that of the electric heating device.

A conventional gas appliance 1 is shown in FIG. 1. Taking a gas furnace as an example, a burner 10, a manual gas regulating valve assembly 12, an igniter 14, an ignition circuit 16, and a thermocouple 18 are included. The burner 10 is used to burn gas to generate a flame. The manual gas regulating valve assembly 12 includes a valve body 122, a knob 124 and a switch 126. The valve body 122 is disposed on a gas line p connecting the burner 10, and the valve body 122 is internally provided with a solenoid valve (not shown). ), to open or block the gas line p, the knob 124 is coupled to the valve body 122 and is operated by the user to open the solenoid valve, and the gas flow output to the burner 10 can be adjusted when the knob 124 rotates. Additionally, when the knob 124 is rotated to the ignition position, the switch 126 will be activated. The igniter 14 is located beside the fire exit of the burner 10. The igniter 14 is electrically connected to the ignition circuit 16. After the switch 126 is activated, the trigger ignition circuit 16 is controlled to output a high voltage to the igniter 14 to generate a spark with respect to the burner 10. The gas output from the burner 10 is ignited. The thermocouple 18 is located beside the burner 10 for detecting the flame and outputting a corresponding detection voltage. The thermocouple 18 is electrically connected to the solenoid valve of the valve body 122 to output the detection voltage to the solenoid valve inside the valve body 122. .

When the user operates the conventional gas appliance 1, the user presses the knob 124 to open the electromagnetic valve in the valve body 122 to allow the gas to pass into the burner 10, and rotates the knob 124 to the ignition position to touch the switch 126 to ignite the ignition. The device 14 is ignited. Please cooperate with FIG. 2, after the gas is ignited, the voltage value of the detection voltage of the thermocouple 18 gradually rises, and after the detection voltage rises to a predetermined voltage value V, the solenoid valve will maintain magnetism, and the user releases the knob 124. After that, the solenoid valve remains open, allowing the gas to continue to pass, thus completing the ignition process.

In the process of ignition, at the beginning of the flame, even if the user sees the flame in the eye, it still needs to wait for a period of time before the thermocouple 18 is heated until the detection voltage reaches the predetermined voltage value V, after which the user can put Turn on the knob 124. If the knob 124 is released in advance, the solenoid valve cannot be magnetized and the gas line p will be blocked immediately. However, the user does not know that the solenoid valve has been magnetized, and can only judge according to his own experience, resulting in inconvenience in use.

Continued to Fig. 2, in addition, after the ignition is successful, if the flame is blown out by the wind, the voltage value of the detection voltage of the thermocouple 18 will gradually decrease, and when it falls below the predetermined voltage value V, the solenoid valve is no longer magnetized and blocked. The gas line p is broken, thereby preventing the gas from continuously leaking from the burner 10.

However, the detection voltage of the thermocouple 18 drops much faster than the detection voltage rises during heating. Therefore, after the flame is blown out, it is often necessary to detect the voltage for a long time (more than 1 minute). It falls below the predetermined voltage value V. In other words, after the flame is blown out, the solenoid valve is blocked for more than 1 minute to block the gas line p.

Imagine that if the gas is turned off during the flow of large gas, the burner 10 will have a large amount of gas leaking for more than 1 minute. This will affect the safety of the gas appliance 1, and even if there is additional spark ignition. The consequences of gas are even more unimaginable.

In view of the above, an object of the present invention is to provide a gas appliance and a control method thereof, which can shorten the judgment time of successful ignition.

Another object of the present invention is to provide a gas appliance and a control method thereof, which can block gas early after the flame is extinguished, thereby improving the safety of use.

In order to achieve the above object, the present invention provides a method for controlling a gas appliance, wherein the gas appliance comprises a burner, a gas valve, an igniter and a thermocouple, wherein the burner has at least one fire outlet; the gas a valve is disposed on a gas line connecting the burner, the gas valve being controlled to open or block the gas line; the igniter is located beside the fire exit of the burner, the igniter is controlled to ignite from the outlet Gas output from the fire port; the thermocouple is located beside the burner for detecting the flame and outputting a corresponding detection voltage; the control method comprises the following steps; A, controlling the ignition of the igniter and opening the gas tube by the gas valve And receiving the detected voltage of the thermocouple output; C. stopping the ignition of the igniter and maintaining the gas valve to open the gas pipeline when the detected voltage rises to a first voltage value; D. Receiving the detected voltage of the thermocouple output, and controlling the gas valve to block the gas pipeline when the detected voltage is lower than a second voltage value lower than the second voltage value, The second voltage value is higher than the first voltage value. The present invention provides a gas appliance comprising: a burner, a gas valve, an igniter, a thermocouple and a control device, wherein the burner has at least one fire outlet; the gas valve is disposed in communication with the burner a gas control pipe that is controlled to open or block the gas line; the igniter is located beside the fire exit of the burner, the igniter is controlled to ignite the gas output from the fire outlet; the thermocouple Located adjacent to the burner for detecting a flame and outputting a corresponding detection voltage; the control device is electrically connected to the gas valve, the igniter and the thermocouple, and the control device controls the igniter to ignite and the gas The valve opens the gas line, and when the detected voltage outputted by the thermocouple reaches a first voltage value, controlling the igniter to stop ignition and maintaining the gas valve open; after that, the control device outputs at the thermocouple Controlling the gas valve to block the gas pipeline when the detected voltage is lower than the second voltage value and lower than the second voltage value, wherein the second voltage value is higher than the first voltage value

The effect of the invention is that the detection voltage outputted by the thermocouple is used as the first voltage value as the basis for determining the ignition success, which can speed up the ignition process of the igniter, shorten the ignition time and reduce the consumption of electric energy during ignition; The second voltage value of the value can be used as a basis for determining the flame extinguishing, and the gas can be blocked early to improve the safety of the gas appliance.

In order that the present invention may be more clearly described, the preferred embodiments are described in detail with reference to the drawings. Referring to FIG. 3, a gas appliance 2 according to a first preferred embodiment of the present invention includes a burner 20, a gas valve 22, an igniter 24, a thermocouple 26 and a control device 28, in this embodiment. The gas appliance is a gas stove, but it is not limited thereto. It can also be any gas heating device such as a fireplace or a water heater.

The burner 20 has at least one firing port for burning gas to generate a flame. The gas valve 22 is disposed on a gas line P that communicates with the burner 20. The gas valve 22 is controlled to open or block the gas line P, and is controlled to regulate the flow of gas to the burner 20. The igniter 24 is located adjacent to the firing port of the combustor 20, and the igniter 24 is controlled to generate a spark relative to the combustor 20 to ignite the gas output from the firing port of the combustor 20. The thermocouple 26 is located adjacent to the burner 20 for detecting a flame and outputting a corresponding detection voltage.

The control device 28 is electrically connected to the gas valve 22, the igniter 24 and the thermocouple 26, and the control device 28 is connected to a trigger signal source exemplified by the switch 30. The switch 30 is triggered by a user to generate a trigger. The signal is output to the control device 28. The control unit 28 has an ignition circuit (not shown) for controlling the igniter 24. The control device 28 is configured to execute the control method of the gas appliance 2 of the embodiment, and the control method comprises the steps shown in FIG. 4, wherein:

Step S01: Receive a trigger signal generated by the switch 30.

Step S02: Control the igniter 24 to ignite, and control the gas valve 22 to open the gas line P to circulate gas to the burner 20.

Step S03: continuously receiving the detected voltage output by the thermocouple 26.

Referring to FIG. 5, after the gas output from the fire outlet of the burner 20 is ignited (time point t1), the detection voltage will continue to rise.

Step S04: When the detected voltage reaches a first voltage value V1 (time point t2), the control device 28 determines that the ignition is successful. At this time, the ignition of the igniter 24 is stopped and the gas valve 22 is controlled to maintain the gas tube. The road P allows the gas to continue to flow to the burner 20. The flame continuously heats the thermocouple 26 to continuously increase the detection voltage from the first voltage value V1 to a predetermined voltage value V, wherein the predetermined voltage value V is a function of the size of the flame (ie, with the output The gas flow rate to the burner 20 may vary). For convenience of explanation, FIG. 5 is used to control the maximum gas flow rate of the gas valve 22, so that the predetermined voltage value V is an example of the maximum output voltage of the thermocouple 26 at the maximum gas flow rate of the gas appliance.

Step S05: Then, the control device 28 continues to receive the detected voltage output by the thermocouple 26. If the flame is not extinguished by the gas valve 22 blocking gas (time point t3), for example, the flame is blown out by the wind, the gas flow is too small or insufficient, the detection voltage of the thermocouple 26 will be higher than a second voltage value V2. The predetermined voltage value V gradually decreases. When the detected voltage falls below the second voltage value V2 (time point t4), the control device 28 determines that the flame is extinguished, and controls the gas valve 22 to block the gas. In the pipeline P, the second voltage value V2 is higher than the first voltage value V1, and in the embodiment, the second voltage value V2 is more than twice the first voltage value V1.

By the above-mentioned process, the gas appliance 2 of the present invention can speed up the process of judging the success of the fire, reduce the time of continuous ignition of the igniter 24, and block the gas earlier in the abnormal flameout, avoiding the gas igniting device 1 in comparison with the conventional gas appliance 1. The gas is leaked from the fire outlet of the burner 20 for a long time.

In order to prevent the flame from being temporarily blown by the wind until it is not in contact with the thermocouple 26, and then contacting the thermocouple 26, the detection voltage of the thermocouple 26 is lower than the second voltage value V2 and then higher than the second voltage value for a short period of time. V2, causing the flame to be blocked to block the gas. In the second embodiment, the gas valve 22 is controlled to block the gas pipeline P when the detection voltage continues for a predetermined time lower than the second voltage value V2. To avoid blocking the gas due to the flame leaving the thermocouple 26 for a short time. Preferably, the predetermined time is within 10 seconds, that is, within 10 seconds (time point t5) after the time point t4 in FIG. 5, the gas valve 22 is controlled to block the gas line P.

In the third embodiment, it is also possible to include, after step S04, the gas flow rate regulated by the control device 28 to output the gas to the burner 20 (for example, the gas flow rate is determined by the opening degree of the gas valve 22 or measured by the flow rate detector). Gas flow rate), and after the gas flow rate outputted to the burner 20 reaches a predetermined flow rate for a predetermined time (2 to 5 minutes in this embodiment), or the slope of the detected voltage with respect to time is reduced to a predetermined time After the slope (ie, the state in which the temperature range of the flame is stable), a voltage value of the detected voltage is recorded, and a new first voltage value V1 is set according to the recorded voltage value for use in the next re-ignition. The predetermined slope in the foregoing is greater than or equal to zero. In this embodiment, the recorded voltage value is at least divided by two and then set to the new first voltage value V1. Preferably, the first voltage value V1 can be set to be three-thirds of the voltage value. Any value between one and one quarter. Preferably, the predetermined flow rate is the maximum gas flow rate output by the gas valve 22, and therefore, the voltage value may be equal to the predetermined voltage value V in FIG. Thereby, the error of the detection voltage due to aging, oxidation or contamination of the thermocouple 26 can be corrected.

In addition, the second voltage value V2 in the step S05 can be set according to the voltage value. In this embodiment, the second voltage value V2 is greater than one-half of the voltage value. Preferably, the first voltage value can be used. The two voltage value V2 is set to any value between two-thirds and three-quarters of the voltage value.

In practice, the voltage value in the foregoing may be a maximum voltage value that can be output when the thermocouple 26 is at a predetermined temperature, and the predetermined flow rate is any gas flow rate when the flame generated by the heat burner can reach the predetermined temperature.

Further, the control method of each of the foregoing embodiments can also be applied to a premixed gas appliance having a blower to premix air and gas to the burner.

According to the above, the present invention can accelerate the ignition process of the igniter, shorten the ignition time and reduce the power consumption during ignition by using the detection voltage outputted by the thermocouple 26 as the first voltage value V1 as the basis for the successful ignition. . The second voltage value V2 greater than the first voltage value V1 is used as a basis for determining that the flame is extinguished, and the gas can be blocked earlier to improve the safety of the gas appliance 2.

Further, a control method of a fourth preferred embodiment is provided, which is based on the first embodiment, and after the step S05, that is, after the control device 28 controls the gas valve 22 to block the gas line P, the following steps are performed. :

The control device 28 continues to receive the detected voltage output by the thermocouple 26. When the control device 28 determines that the detection voltage is higher than the first voltage value, the control device 28 is set to a state of prohibiting ignition. In the state of prohibiting ignition, if the trigger signal generated by the switch 30 is received, Control device 28 does not control the ignition of the igniter and still maintains the gas valve closing the gas line P.

Until the control device 28 determines that the detected voltage is lower than the first voltage value, the control device 28 cancels the state of prohibiting ignition and sets the state to allow ignition. In the state of allowing ignition, if the ignition is received, After the trigger signal generated by the switch 30, the control device 28 controls the ignition of the igniter 24 and the gas valve 22 opens the gas line P.

Thereby, it is ensured that the detected voltage outputted by the thermocouple 26 is below the first voltage value to ignite.

Further, a control method of a fifth preferred embodiment is provided, which is based on the first embodiment, after the step S05, that is, after the control device 28 controls the gas valve 22 to block the gas line P and When the detection voltage is higher than the first voltage value, the following steps are performed:

Referring to FIG. 6 , the time point t6 is used as an example for controlling the time when the gas valve 22 blocks the gas pipeline P. However, the control device 28 continues to receive after the time point t6. The detected voltage is output by the thermocouple 26. The control unit 28 determines whether the detected voltage continues to drop for a predetermined period of time, for example, a period of 10 to 20 seconds, in other words, detecting whether the slope of the detected voltage versus time after the time point t6 is a negative value. If the detected voltage outputted by the thermocouple 26 continues to decrease during the predetermined period, the gas valve 22 is normally blocked by the gas pipeline P. At this time, the control device 28 is set to an ignition state. In the state of allowing ignition, if the trigger signal generated by the switch 30 is received, the control device 28 controls the ignition of the igniter 24 and the gas valve 22 opens the gas line P. Thereby, when the gas valve 22 is closed and the detection voltage is above the first voltage value, it can be ignited again after the predetermined period of time to accelerate the time for re-ignition after the fire is turned off.

If the detected voltage outputted by the thermocouple 26 does not continuously decrease during the predetermined period, the gas valve 22 is not normally blocked by the gas valve 22, and the burner 20 still has a flame. At this time, the control device 28 is set to prohibit ignition. In the state of the ignition prohibition, after receiving the trigger signal generated by the switch 30, the control device 28 does not control the ignition of the igniter, and issues a warning message.

Further, a control method of a sixth preferred embodiment is provided, which is based on the first embodiment. After the step S05, that is, after the control device 28 controls the gas valve 22 to block the gas line P, the following is performed. step:

The control device 28 receives the detected voltage output by the thermocouple 26, and when determining that the detected voltage is higher than a third voltage value, the control device 28 is set to a state of prohibiting ignition, and in the state of prohibiting ignition, If the trigger signal generated by the switch 30 is received, the control device 28 does not control the ignition of the igniter 24, and still maintains the gas valve 22 to close the gas line P. The third voltage value is between the first voltage value and the second voltage value. Preferably, the voltage difference between the third voltage value and the second voltage value is the voltage of the first voltage value and the second voltage value. Less than one third of the value.

Until the control device 28 determines that the detected voltage is lower than the third voltage value, the control device 28 cancels the state of prohibiting ignition and sets the state to allow ignition, and in the state of allowing ignition, if the ignition is received After the trigger signal generated by the switch 30, the control device 28 controls the ignition of the igniter 24 and the gas valve 22 opens the gas line P.

Thereby, when the detected voltage outputted by the thermocouple 26 is between the third voltage value and the first voltage value, the re-ignition after the ignition is extinguished, and the time for re-ignition after the fire is turned off is shortened.

The control methods of the aforementioned fourth to sixth embodiments are equally applicable to the second and third embodiments.

The above is only a preferred embodiment of the present invention, and equivalent changes to the scope of the present invention and the scope of the patent application are intended to be included in the scope of the present invention.

[customary]

1‧‧ ‧ gas appliances

10‧‧‧ burner

12‧‧‧Manual gas control valve assembly

122‧‧‧ valve body

124‧‧‧ knob

126‧‧‧ switch

14‧‧‧Igniter

16‧‧‧Ignition circuit

18‧‧‧Thermal coupler

P‧‧‧ gas pipeline

V‧‧‧predetermined voltage value

[this invention]

2‧‧ ‧ gas appliances

20‧‧‧ burner

22‧‧‧ gas valve

24‧‧‧Igniter

26‧‧‧Thermal coupler

28‧‧‧Control device

30‧‧‧ switch

P‧‧‧ gas pipeline

S01~S05‧‧‧Steps

T1~t6‧‧‧ time point

V1‧‧‧ first voltage value

V2‧‧‧ second voltage value

V3‧‧‧ third voltage value

V‧‧‧predetermined voltage value

Figure 1 is a schematic view of a conventional gas appliance. Fig. 2 is a graph showing the detection voltage versus time of a thermocouple of a conventional gas appliance. 3 is a schematic view of a gas appliance according to a first preferred embodiment of the present invention. 4 is a flow chart of the control method of the above preferred embodiment. FIG. 5 is a graph showing the relationship between the detected voltage and the time of the thermocouple of the above preferred embodiment. FIG. 6 is a graph showing the relationship between the detected voltage and the time of the thermocouple of the fifth preferred embodiment of the present invention. FIG. 7 is a graph showing the relationship between the detected voltage and the time of the thermocouple of the sixth preferred embodiment of the present invention.

Claims (19)

A gas appliance control method, wherein the gas appliance comprises a burner, a gas valve, an igniter and a thermocouple, wherein the burner has at least one fire outlet; the gas valve is disposed in a gas that communicates with the burner In the pipeline, the gas valve is controlled to open or block the gas pipeline; the igniter is located beside the fire exit of the burner, the igniter is controlled to ignite the gas output from the fire outlet; the thermocouple is located at the Next to the burner, the flame is detected and a corresponding detection voltage is output; the control method comprises the following steps: A. controlling the ignition of the igniter and the gas valve opening the gas pipeline; B, receiving the output of the thermocouple The detecting voltage; C. stopping the ignition of the igniter and maintaining the gas valve to open the gas pipeline when the detecting voltage rises to a first voltage value; D, continuously receiving the detecting voltage of the thermocouple output And controlling the gas valve to block the gas pipeline when the detection voltage is lowered from the second voltage value to be lower than the second voltage value, wherein the second voltage value is higher than the first electricity Value. The method for controlling a gas appliance according to claim 1, wherein in the step D, the gas valve is controlled to block the gas pipeline when the detection voltage continues for a predetermined time and is lower than the second voltage value. The method of controlling a gas appliance according to claim 2, wherein the predetermined time is within 10 seconds. The control method of the gas appliance according to claim 1, wherein the step C includes after the slope of the detected voltage with respect to time is reduced to a predetermined slope, or the gas flow rate outputted to the burner reaches a predetermined flow rate and After maintaining a predetermined time, a voltage value of the detected voltage is recorded, and a new first voltage value is set according to the recorded voltage value, wherein the predetermined slope is not less than zero. The method for controlling a gas appliance according to claim 4, wherein the step C is followed by setting the recorded voltage value to at least two and setting the new first voltage value. The method of controlling a gas appliance according to claim 5, wherein the first voltage value is between one third and one quarter of the voltage value. The method for controlling a gas appliance according to claim 1, wherein the steps C and D include after the slope of the detected voltage decreases with respect to time to a predetermined slope, or the gas flow rate to the burner reaches one. After the predetermined flow rate is maintained for a predetermined period of time, a voltage value of the detected voltage is recorded; in the step D, the second voltage value is set according to the recorded voltage value, wherein the predetermined slope is not less than zero. The method of controlling a gas appliance according to claim 7, wherein the second voltage value is greater than one-half of the voltage value. The method of controlling a gas appliance according to claim 8, wherein the second voltage value is between two-thirds and three-quarters of the voltage value. The method of controlling a gas appliance according to claim 1, wherein the second voltage value is more than twice the value of the first voltage. The method for controlling a gas appliance according to claim 1, wherein in step A, after the trigger signal is received, the ignition of the igniter is controlled and the gas valve is opened to the gas pipeline; after step D and at the detection voltage is high The first voltage value further includes: receiving the detection voltage of the thermocouple output, and determining that the detection voltage continues to decrease for a predetermined period of time, after receiving the trigger signal, controlling the ignition of the igniter and The gas valve opens the gas line. The method for controlling a gas appliance according to claim 11, wherein after the step D is determined that the detection voltage does not continuously decrease during the predetermined period, the ignition of the igniter is not controlled after receiving the trigger signal. The method for controlling a gas appliance according to claim 1, wherein in step A, after receiving a trigger signal, the ignition of the igniter is controlled and the gas valve is opened to the gas pipeline; after step D, the method further comprises: receiving the thermocouple Outputting the detection voltage, after the detection voltage is lower than a third voltage value and receiving the trigger signal, controlling the ignition of the igniter and the gas valve to open the gas pipeline; wherein the third voltage value is between The first voltage value is between the second voltage value. The method for controlling a gas appliance according to claim 13, wherein after the step D is determined to be higher than the third voltage value, the ignition of the igniter is not controlled after receiving the trigger signal. The method of controlling a gas appliance according to claim 13, wherein a voltage difference between the third voltage value and the second voltage value is less than one third of a voltage value of the first voltage value and the second voltage value. The method for controlling a gas appliance according to claim 1, wherein in step A, after receiving a trigger signal, the ignition of the igniter is controlled and the gas valve is opened to the gas pipeline; after step D, the method further comprises: receiving the thermocouple The detected detection voltage, when the detection voltage is higher than the first voltage value, after the trigger signal is received, the gas valve is maintained to close the gas pipeline; the detection voltage is lower than the first At the voltage value, the ignition of the igniter is controlled after the trigger signal is received and the gas valve is opened by the gas valve. A gas appliance comprising: a burner having at least one fire outlet; a gas valve disposed on a gas line connecting the burner, the gas valve being controlled to open or block the gas pipeline; an igniter, Located next to the fire exit of the burner, the igniter is controlled to ignite the gas output from the fire outlet; a thermocouple is located beside the burner for detecting the flame and outputting a corresponding detection voltage; a device electrically connected to the gas valve, the igniter and the thermocouple, the control device controls the igniter to ignite and the gas valve opens the gas pipeline, and the detection voltage at the thermocouple output reaches a first Controlling the igniter to stop ignition and maintaining the gas valve to open; then, the detecting voltage of the control device at the thermocouple output is lowered from a second voltage value to lower than the second voltage value And controlling the gas valve to block the gas pipeline, wherein the second voltage value is higher than the first voltage value. The gas appliance of claim 17, wherein the control device controls the gas valve to block the gas line when the detection voltage output by the thermocouple is lower than the second voltage value for a period of time. The gas appliance of claim 17, wherein the second voltage value is more than twice the value of the first voltage.