JP2019219081A - Combustion control method of gas flyer - Google Patents

Abstract

To solve a problem that, when igniting a gas burner of a gas flyer, the gas burner is ignited by being supplied with a gas at the secondary pressure lower than the primary pressure of a gas supplied from the outside, however, when igniting the gas burner once again after a failure of the first ignition, an unburnt gas remaining in a combustion chamber may be explosively ignited, thus causing the instability of a time up until the complete reignition after the ignition failure due to a variation of the gas secondary pressure, and a malfunction in usability.SOLUTION: In a gas flyer in which a gas burner is ignited by setting the pressure of a gas supplied to the gas burner to secondary pressure lower than primary pressure which is supplied at normal combustion at the ignition of the gas burner, when the secondary pressure which is set at the first ignition of the gas burner is higher than prescribed reference secondary pressure, a time up to the reignition of the gas burner due to an ignition failure of the gas burner is set long, and when the secondary pressure which is set at the first ignition of the gas burner is lower than the prescribed reference secondary pressure, the time up to the reignition of the gas burner is set short.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a gas fryer combustion control method for burning gas supplied from the outside with a gas burner, heating cooking oil stored in an oil storage tank with high-temperature combustion gas (flame) and frying food. .

  Commercial gas fryers are widely used in restaurants and convenience stores. This gas fryer includes an oil storage tank provided in the main body, and heating means for heating the cooking oil stored in the oil storage tank. As the heating means, a gas burner disposed outside the oil storage tank and heating the oil storage tank by burning gas, an electric heater immersed in cooking oil in the oil storage tank to directly heat the cooking oil, and the like There is. The present invention relates to a gas fryer combustion control method using a gas burner as a heating means. A gas fryer employing a gas burner is disclosed in Patent Document 1.

  FIG. 11 is a vertical sectional side view showing a schematic configuration of the gas fryer 10. The gas fryer 10 has a box-shaped main body 12, an oil storage tank 14 opened upward and disposed in the main body 12, A gas burner 16 is provided in the main body 12 below the front side of the oil storage tank 14. An inner box 18 is provided on the outer surface of the oil storage tank 14, and a combustion gas passage 20 for moving the combustion gas of the gas burner 16 is formed between the oil storage tank 14 and the inner box 18. At the rear of the main body 12 (on the rear side of the oil storage tank 14), an exhaust duct 22 communicating with the combustion gas passage 20 is provided upright, and the high-temperature combustion gas from the gas burner 16 is heated between the main body 12 and the oil storage tank 14. The oil storage tank 14 is heated by replacement, and is raised from the combustion gas passage 20 to the exhaust duct 22 to be discharged to the outside. Then, the combustion gas rises in the exhaust duct 22 to generate a so-called draft effect (chimney effect), so that the combustion air in the gas burner 16 flows from the intake port 24 opened adjacent to the top of the exhaust duct 22 to the inner side. It is taken in the box 18.

  As shown in FIG. 11, the gas fryer 10 is provided with two solenoid valves 28 and 30 in the middle of a gas supply pipe 26 connected to the gas burner 16, and the control circuit 32 shown in FIG. , 30 is controlled to open and close to supply and shut off gas to the gas burner 16 via the gas supply pipe 26. FIG. 12 schematically shows a piping system and an ignition system of the gas burner 16. In the gas fryer 10 of FIG. 12, two gas burners 16a and 16b are arranged in parallel in a combustion chamber 34 defined forward between the oil storage tank 14 and the inner box 18. A gas supply pipe 26 derived from an external gas supply source has a first solenoid valve 28 for supplying and blocking gas to the first gas burner 16a and a second solenoid valve for supplying and blocking gas to the second gas burner 16b. An electromagnetic valve 30 is provided. Downstream of the first solenoid valve 28 and the second solenoid valve 30 is a proportional control valve 36 for adjusting the gas supply to a secondary pressure lower than the primary pressure of the gas supply when each gas burner 16 is ignited. Is provided.

  Further, in the vicinity of the nozzle of each gas burner 16, an ignition means 38 typified by a spark rod and a flame detection means (frame rod) 40 as an ignition detection means are provided. As shown in FIG. 10, the ignition means 38 receives a high voltage supply from a high voltage generation means 42 driven by an instruction from the control circuit 32, ignites a spark or the like, and ignites the nozzle of the gas burner 16. It is supposed to.

  Further, the flame detecting means 40 detects whether or not each gas burner 16 is ignited (ignited) or failed in ignition by the ignition means 38 based on the presence or absence of a flame. In the present invention, a thermocouple that detects the temperature of the flame is preferably used. Whether the gas burner 16 has been ignited is determined by detecting a change in the temperature signal from the flame detection means 40 by the flame detection circuit 44 in FIG. 10 and inputting ignition confirmation or ignition failure to the control circuit 32. I have.

JP-A-3-105115

  When igniting the gas burner 16 with the gas fryer 10 shown in FIG. 12, a spark is emitted from an ignition means 38 represented by a spark rod to ignite the gas. When the gas burner 16 is ignited, the gas supply pressure to the nozzle adversely affects the carbon dioxide concentration of the exhaust gas. For this reason, the pressure (referred to as primary pressure) of the gas supplied from the outside to the gas supply pipe 26 is lower than that during normal combustion only when the gas burner 16 is ignited. It is adjusted by the proportional control valve 36. Further, if the ignition of the gas burner 16 by the ignition means 38 fails, if the ignition is immediately performed again without time, the residual gas diffused in the combustion chamber 34 at the time of the previous ignition failure is ignited, so-called “explosion ignition”. " For this reason, when reignition occurs due to ignition failure, reignition is not performed immediately even if the operator presses the ignition switch 46 shown in FIG. 10, but is automatically performed after a certain period of time (gas concentration decreases). Is controlled.

  However, if the gas burner 16 fails to ignite and then automatically reignites after a certain period of time, if the gas secondary pressure at the gas burner 16 at the time of ignition is high, the ignition will fail. In this case, a large amount of unburned gas fills the combustion chamber 34 and the gas concentration increases. At this time, the explosion may occur at the time of re-ignition because the gas concentration is still high even after a certain period of time has elapsed. That is, reignition is not always safe even after a certain time has elapsed.

  Conversely, if the gas secondary pressure at the time of ignition is low, the diffusion of unburned gas in the combustion chamber 34 when the ignition has failed is small. That is, since the concentration of the remaining unburned gas is low, re-ignition may be performed automatically without waiting for a certain time. For this reason, even if it is desired to re-ignite as soon as possible after the ignition failure, a certain period of time has to be waited, which wastes time.

  The present invention has been proposed in view of the problems inherent in the conventional gas fryer, and has been proposed in order to solve the problem appropriately.When reignition of the gas burner fails at the gas secondary pressure, Rather than re-igniting after a certain period of time, the time for safe automatic re-ignition is changed according to the fluctuation of the gas secondary pressure, so that unnecessary time is required before explosion ignition or re-ignition. It is an object of the present invention to provide a method for controlling combustion of a gas burner that does not cause the burning.

In order to solve the above problems and achieve the intended purpose, the invention according to claim 1
Combustion control of a gas fryer in which the pressure of gas supplied to a gas burner for heating oil in an oil storage tank is set to a secondary pressure lower than the primary pressure supplied during normal combustion when the gas burner is ignited. In the method,
When the secondary pressure set at the time of the first ignition of the gas burner is higher than a predetermined reference secondary pressure, a time until re-ignition due to a failure in ignition of the gas burner is set longer,
When the secondary pressure set at the time of the first ignition of the gas burner is lower than the predetermined reference secondary pressure, the point is that the time until reignition of the gas burner is set short.
According to the first aspect of the present invention, if the gas secondary pressure at the time of ignition is higher than the reference gas secondary pressure, the time until re-ignition is automatically set to be long to reduce the residual gas. So it doesn't ignite even if re-ignited. Conversely, if the gas secondary pressure is lower than the reference gas secondary pressure, setting a short time until re-ignition can prevent unnecessary redundant standby time.

The invention according to claim 2 solves the above-mentioned problem and achieves an intended purpose.
Combustion control of a gas fryer in which the pressure of gas supplied to a gas burner for heating oil in an oil storage tank is set to a secondary pressure lower than the primary pressure supplied during normal combustion when the gas burner is ignited. In the method,
When the temperature of the oil in the oil storage tank is always detected by the oil temperature detecting means, and when the ignition of the gas burner fails and is re-ignited,
If the temperature of the oil detected by the oil temperature detecting means is higher than a predetermined reference temperature, the time until re-ignition due to ignition failure of the gas burner is set short,
When the oil temperature detected by the oil temperature detecting means is lower than a predetermined reference temperature, the gist is that the time until re-ignition due to the failure of ignition of the gas burner is set longer.
According to the invention according to claim 2, when the oil temperature is higher than when the time until the automatic re-ignition after failing the ignition is kept constant in accordance with the case where the oil temperature in the oil storage tank is low, The time required for automatic re-ignition can be shortened, and therefore the fall of the fryer oil temperature until re-ignition can be prevented.

The invention according to claim 3 solves the above-mentioned problem and achieves an intended purpose.
Combustion control of a gas fryer in which the pressure of gas supplied to a gas burner for heating oil in an oil storage tank is set to a secondary pressure lower than the primary pressure supplied during normal combustion when the gas burner is ignited. In the method,
When always detecting the wind speed around the gas burner by the wind speed detecting means, and reigniting after failing to ignite the gas burner,
When the wind speed detected by the wind speed detecting means is higher than a predetermined reference wind speed, the time until re-ignition due to the failure of ignition of the gas burner is set short,
When the wind speed detected by the wind speed detecting means is lower than a predetermined reference wind speed, the gist is that the time until re-ignition due to failure of ignition of the gas burner is set longer.
According to the third aspect of the invention, the wind around the gas burner is stronger than the case where the time until the automatic re-ignition after the failure of the ignition is set to be constant in accordance with the case where the wind near the gas burner is weak. At times, the time until automatic reignition can be shortened. For this reason, it is possible to prevent a decrease in the oil temperature in the oil storage tank 14 until re-ignition.

In order to solve the above-mentioned problems and achieve the intended purpose, the invention according to claim 4 is
Combustion control of a gas fryer in which the pressure of gas supplied to a gas burner for heating oil in an oil storage tank is set to a secondary pressure lower than the primary pressure supplied during normal combustion when the gas burner is ignited. In the method,
If the elapsed time after extinguishing the gas burner is shorter than a predetermined reference time, the time until automatic reignition of the gas burner is set shorter,
When the elapsed time after extinguishing the gas burner is longer than the reference time, the gist is that the time until automatic reignition of the gas burner is set longer.
According to the invention according to claim 4, the elapsed time after extinguishment of the gas burner is shorter than the conventional method in which the time until re-ignition after extinguishing the fire is made constant in accordance with the case where the elapsed time after extinguishing is long. Sometimes, the time until automatic re-ignition can be shortened, so that a decrease in oil temperature in the oil storage tank until re-ignition can be prevented.

In order to solve the above problems and achieve the intended purpose, the invention according to claim 5
When igniting the gas burner, the gas supplied to the gas burner that heats the oil in the oil storage tank is ignited at a secondary pressure lower than the primary pressure supplied during normal combustion, and the ignition of the gas burner fails. In the case of a gas fryer combustion control method that automatically reignites after a time that is a function elapses,
When the main power is turned off without re-ignition when the ignition fails, even if the ignition switch is turned on after the main power is turned on, the time that is the function has elapsed since the main power was turned on. The gist is that automatic ignition is performed only later.
According to the invention according to claim 5, when the ignition is failed, when the power is turned off without re-ignition, "a certain time" has elapsed from the power-on even if the ignition instruction is issued at the next power-on. Since the ignition is controlled only later, the explosion and ignition by the unburned gas remaining in the combustion chamber is eliminated.

  ADVANTAGE OF THE INVENTION According to the combustion control method of the gas fryer according to the present invention, after the ignition of the gas burner fails under the gas secondary pressure, even if it is automatically re-ignited, the explosion does not occur, and the waste until the re-ignition does not occur. This has the effect of eliminating the lapse of time.

4 is a flowchart illustrating a gas fryer combustion control method according to the first embodiment of the present invention. FIG. 1 is a graph showing the time behavior of the gas concentration when the ignition fails after the gas valve is opened at the time of ignition in Example 1 shown in FIG. 1, and shows that the explosion ignition time differs depending on the level of the gas secondary pressure. Is shown. 6 is a flowchart illustrating a gas fryer combustion control method according to Embodiment 2 of the present invention. FIG. 3 is a graph showing the time behavior of the gas concentration when the ignition fails after the gas valve is opened at the time of ignition in the second embodiment shown in FIG. 3, showing that the explosion ignition time varies depending on the oil temperature. I have. It is a flowchart which shows the combustion control method of the gas fryer which concerns on Example 3 of this invention. FIG. 5 is a graph showing the time behavior of the gas concentration when the ignition fails after the gas valve is opened at the time of ignition in Example 3 showing that the explosion ignition time differs depending on the magnitude of the wind speed near the gas burner. Is shown. It is a flowchart which shows the combustion control method of the gas fryer which concerns on Example 4 of this invention. FIG. 7 is a graph showing the time behavior of gas concentration when ignition fails after the gas valve is opened during ignition in Example 4 shown in FIG. 7. Is shown. It is a flowchart which shows the combustion control method of the gas fryer which concerns on Example 5 of this invention. 1 is a block diagram of a control system used for carrying out a gas fryer combustion control method according to the present invention. It is a vertical side view which shows the schematic structure of a general gas fryer. It is a schematic front view showing a gas burner in a gas fryer with a gas supply system and an ignition system.

  Next, a method for controlling combustion of a gas fryer according to the present invention will be described with reference to the accompanying drawings, using Examples 1 to 5. The gas fryer that executes the combustion control method according to each embodiment has the configuration described with reference to FIGS.

  As described with reference to FIGS. 11 and 12, the gas fryer 10 that implements the combustion control method of the present invention is configured such that the pressure of the gas supplied to the gas burner 16 that heats the oil stored in the oil storage tank 14 ignites the gas burner 16. At this time, the secondary pressure is controlled to be lower than the primary pressure supplied during normal gas combustion. In the first embodiment, the secondary pressure when the gas burner 16 is initially ignited in the gas fryer 10 is not always constant. The time is varied according to the “secondary pressure serving as a reference”.

  For example, the graph of FIG. 2 shows the behavior of gas concentration when ignition fails after the gas valve is opened at the time of ignition. The vertical axis represents the concentration (ppm) of unburned gas in the combustion chamber 34, and the horizontal axis represents Represents elapsed time (seconds). In FIG. 2, the horizontal axis indicated by a dashed line indicates the lower limit concentration of gas combustion. When the concentration of the unburned gas remaining in the combustion chamber 34 is higher than the lower limit concentration, the above-described explosion is performed by re-ignition. There is a high possibility of ignition. In FIG. 2, when the gas secondary pressure (solid line) at the time of ignition is 2.0 kPa, the gas combustion lower limit concentration is reached after the elapse of B seconds. When the gas secondary pressure (dashed line) at the time of ignition is 1.0 kPa, the explosion does not occur if re-ignition is performed after the elapse of A seconds.

The gas used in FIG. 2 is a city gas, and when propane gas (LPG) is used, a tendency different from that of the city gas is shown. For example, "time (seconds) until automatic re-ignition after ignition failure" due to use of city gas and use of propane gas (LPG) is as follows.

  As described above, it can be seen that the fluctuation in the gas secondary pressure when the gas burner 16 is ignited for the first time has an effect on the time of whether the explosion and ignition occur when the automatic reignition is performed after the ignition failure. That is, the lower the gas secondary pressure at the time of igniting the gas burner 16 in the gas fryer 10, the shorter the time until automatic ignition after igniting failure can be shortened. Therefore, in the present embodiment, a set value of a predetermined reference secondary pressure is input to the control circuit 32 in advance by the reference secondary pressure setting means 48 shown in FIG. 10 with respect to the gas secondary pressure when the gas burner 16 is ignited. Remember it. The gas secondary pressure set by the proportional control valve 36 is also input to the control circuit 32, and the actually set gas secondary pressure and the reference gas secondary pressure are compared in the control circuit 32. The time to reignite automatically is adjusted. With this adjusted time, an instruction to drive the high voltage generating means 42 is issued from the reignition instruction circuit 50 shown in FIG. 10, and the gas burner 16 is reignited by the spark from the ignition means 38. That is, when the secondary pressure set at the time of the first ignition of the gas burner 16 is higher than a predetermined reference secondary pressure, the time until re-ignition due to ignition failure to the gas burner 16 is set longer, and conversely, the gas burner 16 is set. If the secondary pressure set at the time of the first ignition of No. 16 is lower than the predetermined reference secondary pressure, the time until reignition of the gas burner 16 is set short.

  Next, an operation flow of the combustion control method according to the first embodiment will be described with reference to FIG. First, after the main power switch 52 shown in FIG. 10 is turned on to energize the electric system of the gas fryer 10, the ignition switch 46 is turned on in step S1. As a result, in step S2, the proportional control valve 36 operates to adjust the gas pressure at the time of ignition of the gas burner to the secondary pressure. Next, in step S3, the ignition means (for example, a spark rod) 38 operates to ignite the nozzle of the gas burner 16.

  If the gas burner 16 is ignited, the temperature rises due to the flame. The flame detection means 40 detects this, and inputs information to the control circuit 32 via the flame detection circuit 44. Therefore, in step S4, it is confirmed whether or not the ignition of the gas burner 16 has failed. If the ignition has been normally performed, the determination is negative (NO), and the normal combustion of the gas burner 16 is continued in step S5. However, if the ignition in the gas burner 16 has failed, the result is affirmative (YES) in step S4, and the process proceeds to step S6.

  In step S6, it is confirmed whether or not the gas secondary pressure set at the time of gas ignition is higher than the reference secondary pressure set by the reference secondary pressure setting means 48 in FIG. If the determination in step S6 is negative (NO), the unburned gas is less scattered in the combustion chamber 34 at the time of ignition failure, so that the process proceeds to step S7 and the time until automatic re-ignition is set short. Then, in step S9, the ignition means 38 is driven via the reignition instruction circuit 50 (FIG. 10) to cause automatic reignition. If the result of the determination in step S6 is affirmative (YES), it means that the residual diffusion of the unburned gas was large at the time of ignition failure, so that the process proceeds to the next step S8 and the time until automatic re-ignition is set longer. I do. Next, in step S9, the ignition means 38 is turned on to instruct re-ignition. Even if the process proceeds from step S7 or from step S9, it is reconfirmed whether reignition has failed in step S10, and if not, the determination is negative (NO) and the normal combustion in step S11 is performed. continue. If the reignition failure is affirmed (YES) in step S10, the routine returns to step S6 and the routine is performed again. That is, the time until the automatic re-ignition after the failure of the ignition is made to be lower at the time of the ignition of the gas burner than at the time when the time until the automatic re-ignition of the gas fryer is made constant in accordance with the higher one. If this is done, the time until automatic re-ignition can be shortened, so that a decrease in oil temperature until re-ignition can be prevented.

  In the first embodiment described above, the function for correcting the time from the ignition failure to the automatic reignition with respect to the fluctuation of the gas secondary pressure at the time of ignition is the setting of the gas secondary pressure as a reference. On the other hand, the second embodiment presents another correction criterion as a function, and focuses on the temperature of the cooking oil in the oil storage tank 14.

  For example, the graph of FIG. 4 is basically the same as the graph of FIG. 2 described above, and shows the behavior of the gas concentration when ignition fails after the gas valve is opened at the time of ignition. In FIG. 4, the horizontal axis indicated by a dashed line indicates the lower limit concentration of gas combustion, and when the concentration of unburned gas remaining in the combustion chamber 34 is higher than the lower limit concentration, re-ignition is performed as described above. There is a high possibility of ignition. In FIG. 4, when the oil temperature at the time of ignition (solid line) is 20 ° C., the gas combustion lower limit concentration is reached after elapse of B seconds. When the oil temperature at the time of ignition (broken line) is 200 ° C., the explosion does not occur if re-ignition is performed after A seconds have elapsed. This is because when the oil temperature of the oil storage tank 14 is higher than the ambient temperature, an upward airflow is generated in the combustion chamber 34, and the unburned gas remaining in the combustion chamber 34 is diffused and its concentration is reduced. That is, the higher the oil temperature of the oil storage tank 14 in the gas fryer 10, the shorter the time until automatic re-ignition after a failed ignition can be set.

  Therefore, in the second embodiment, the oil temperature is detected by oil temperature detecting means 54 such as a thermistor, and the control circuit 32 shown in FIG. 10 adjusts the time for automatically reigniting the gas burner 16. At the adjusted time, a driving instruction for the high-voltage generating means 42 is issued from the re-ignition instruction circuit 50 in FIG. 10, and the gas burner 16 is re-ignited by the spark from the ignition means 38. That is, when the oil temperature of the oil storage tank 14 is high, the time until re-ignition due to a failure in ignition of the gas burner 16 is set short. Conversely, when the oil temperature is low, the time until re-ignition of the gas burner 16 is set. Is set to be longer.

  An operation flow of the combustion control method according to the second embodiment will be described with reference to FIG. In FIG. 3, the flow from step S1 to step S5 is the same as the flow in FIG. If the determination result of the ignition failure is affirmative (YES) in step S4, it is checked in step S6 whether the oil temperature is higher than a temperature set in advance as a reference. If the determination result in step S6 is negative (NO), the updraft in the combustion chamber 34 is considered to be small as a result of the low oil temperature, so that the residual concentration of the unburned gas is high. Therefore, the process proceeds to step S7 to set a longer time until automatic reignition, and then the reignition instruction circuit 50 instructs the gas burner 16 to reignite in step S9.

  If the determination result in step S6 is that the detected oil temperature is higher than the reference oil temperature, it is considered that the unburned gas has been diffused because the updraft of the combustion chamber 34 is large. Set a shorter time until transition and automatic reignition. Next, after the process proceeds to step S9, the flow is the same as the flow of FIG. 1 in the first embodiment described above. In this way, the time until the automatic reignition after the failure of the ignition is set to be constant in accordance with the case where the oil temperature in the oil storage tank is low. The time can be shortened, and therefore the fall of the fryer oil temperature until re-ignition can be prevented.

  In the second embodiment described above, the function for correcting the time from the ignition failure to the automatic re-ignition focuses on the temperature of the cooking oil in the oil storage tank 14. On the other hand, in the third embodiment, the wind speed flowing near the gas burner 16 is made a function as another correction reference.

  For example, the graph of FIG. 6 is basically the same as the graph of FIG. 2 described above, and shows the behavior of the gas concentration when ignition fails after the gas valve is opened at the time of ignition. In FIG. 6, the horizontal axis indicated by a dashed line indicates the lower limit concentration of gas combustion, and when the concentration of the unburned gas remaining in the combustion chamber 34 is higher than the lower limit concentration, re-ignition is performed as described above. There is a high possibility of ignition. In FIG. 6, when the wind speed near the gas burner 16 is 0.1 m / s (solid line), the gas combustion lower limit concentration is reached after the elapse of B seconds. When the wind speed is as strong as 2 m / s (broken line), the explosion does not occur if re-ignition is performed after the elapse of A seconds. This is because if the velocity of the wind flowing in the vicinity of the gas burner 16 in the combustion chamber 34 is high, the unburned gas remaining in the combustion chamber 34 is diffused early and the concentration is reduced. Conversely, if the wind velocity is low, the residual gas is compared. This is because the stagnation becomes longer and the concentration becomes higher. That is, as the wind speed near the gas burner 16 in the gas fryer 10 becomes higher, the time until automatic re-ignition after the ignition failure can be set shorter.

  Therefore, in the third embodiment, as shown in FIG. 12, a probe (described later) of a wind speed detecting means 56 installed near the gas burner 16 detects the wind speed near the gas burner, and the control circuit 32 shown in FIG. Adjust the time to relight. At the adjusted time, a driving instruction for the high-voltage generating means 42 is issued from the re-ignition instruction circuit 50 in FIG. 10, and the gas burner 16 is re-ignited by the spark from the ignition means 38. That is, when the wind speed in the combustion chamber 34 is high, the time until re-ignition due to a failure in ignition of the gas burner 16 is set short, and conversely, when the wind speed is low, the time until re-ignition to the gas burner 16 is set long. Is what you do. As the wind speed detecting means 56, for example, two temperature detecting probes having excellent heat resistance are provided, and one of the temperature detecting probes faces the vicinity of the gas burner 16 to change at the speed of the wind flowing near the gas burner. It is recommended that the temperature difference between the two probes be converted into an electric wind speed signal by a transducer. In this case, the electric signal converted by the transducer is input to the control circuit 32 in FIG. Further, the wind speed detecting means 56 can change the detection range in accordance with the measured wind speed, and can store the reference wind speed in the control circuit 32 in advance.

  An operation flow of the combustion control method according to the third embodiment will be described with reference to FIG. In FIG. 5, the flow from step S1 to step S5 is the same as the flow in FIG. If the determination result of the ignition failure is affirmative (YES) in step S4, it is checked in step S6 whether the wind speed is higher than a preset reference wind speed. If the determination result of step S6 is negative (NO), the residual concentration of the unburned gas in the combustion chamber 34 is high as a result of the low wind speed. Therefore, the process proceeds to step S7 to set a longer time until automatic reignition, and then the reignition instruction circuit 50 instructs the gas burner 16 to reignite in step S9.

  If the determination result of the wind speed is higher than the reference wind speed in step S6 (positive), it is considered that the unburned gas is diffused in the combustion chamber 34 and the concentration is reduced. Set a shorter time until reignition. Next, after the process proceeds to step S9, the flow is the same as the flow of FIG. 1 in the first embodiment described above. As described above, according to the control method of the third embodiment, the time until the automatic reignition after the failure of the ignition is set to be constant in accordance with the case where the wind near the gas burner is weak. Even when the wind is strong, the time until automatic relighting can be shortened. For this reason, it is possible to prevent a decrease in the oil temperature in the oil storage tank 14 until re-ignition. In particular, when frying frozen foods, the oil temperature tends to decrease, and this decrease in the oil temperature causes the finished product to have a sticky appearance and reduce its commercial value. However, in the third embodiment, such inconvenience can be avoided.

  In the second embodiment described above, the function for correcting the time from the ignition failure to the automatic re-ignition focuses on the temperature of the cooking oil in the oil storage tank 14. On the other hand, in the fourth embodiment, as another correction criterion, the reignition interval of the gas burner 16 is made a function of the elapsed time after the fire is extinguished.

  For example, the graph of FIG. 8 is basically the same as the graph of FIG. 2 described above, and shows the behavior of the gas concentration when ignition fails after the gas valve is opened at the time of ignition. In FIG. 8, the horizontal axis indicated by a dashed line indicates the lower limit concentration of gas combustion, and when the concentration of unburned gas remaining in the combustion chamber 34 is higher than the lower limit concentration, re-ignition is performed as described above. There is a high possibility of ignition. In FIG. 8, when the elapsed time after extinguishing the gas burner 16 is 200 seconds (solid line), the gas combustion lower limit concentration is reached after B seconds elapse, and it can be seen that explosion and ignition will not occur if reignition is performed thereafter. If the elapsed time after the extinguishing is 30 seconds (broken line), the explosion does not occur if re-ignition is performed after the elapse of A seconds. The reason is that if the elapsed time after extinguishing the gas burner 16 is as short as 30 seconds, the combustion chamber 34 is in a state of being warmed by the gas combustion before this. For this reason, even after the fire is extinguished, the indoor temperature decreases slowly due to the large heat capacity of the metal plate, such as stainless steel, surrounding the combustion chamber 34, and a rising airflow is generated in the combustion chamber 34, whereby the unburned gas is diffused. Because it becomes easy. That is, the shorter the time elapsed after the gas burner 16 was extinguished, the shorter the time from the failure of ignition to the automatic reignition can be shortened.

  An operation flow of the combustion control method according to the fourth embodiment will be described with reference to FIG. In FIG. 7, the flow from step S1 to step S3 is the same as the flow in FIG. When the ignition operation is performed in step S3, the gas burner 16 normally burns to heat the oil storage tank 14, and fried food is cooked. Then, for example, when the cooking of the fried food is completed, the fire of the gas burner 16 is extinguished in step S5. When the cooking of the fried food is resumed after this fire extinguishing, the ignition means is turned on in step S6, and in the next step S7, it is checked whether the elapsed time after the previous fire extinguishing is shorter than a preset reference time, and the judgment result is obtained. Is negative (NO), the time until automatic ignition is set short in step S8. Next, after automatic ignition in step S9, it is checked in step S12 whether ignition has failed. If the result is negative (NO), normal combustion is continued in step S13. If the elapsed time is short in step S7, the result is affirmative (YES), the time until automatic reignition is set long in the next step S10, and then automatic ignition is performed in step S11. The following routines are the same as the routines transferred from the previous step S9.

  In the control method according to the invention of the fourth embodiment, the elapsed time after extinguishment of the gas burner is longer than the conventional method in which the time until re-ignition after extinguishing the fire is made constant in accordance with the case where the elapsed time after extinguishing is long. When the time is short, the time until automatic re-ignition can be shortened, and therefore, a decrease in oil temperature in the oil storage tank 14 until re-ignition can be prevented. In particular, when frying frozen foods, the oil temperature tends to decrease, and this oil temperature decrease causes the finished product to have a sticky appearance and reduce its commercial value. However, the control method according to the fourth embodiment can avoid such inconvenience.

  The fourth embodiment described above relates to a control method in a case where the gas burner 16 is ignited, fried food is cooked in the oil storage tank 14, the gas burner 16 is extinguished after cooking is completed, and then ignited again. On the other hand, in the control method of the fifth embodiment, when the ignition of the gas burner 16 fails, the main power is turned off (off), and then when the main power is turned on (on), the time interval required for reignition is automatically set. It is intended to be able to secure it.

  Further, when the “certain time” changes depending on the gas burner status, it may be either the state when the power is turned off or the time determined when the power is turned on. Except for the gas secondary pressure at the time of ignition, the time determined when the power is turned on is more preferable because explosion and ignition are close to each other.

  FIG. 9 shows a control flow of the fifth embodiment. Steps S1 to S4 are the same as those in FIG. As a result of checking whether ignition has failed in step S4, if the determination result is negative (NO), the process proceeds to step S5 to perform normal combustion.

  However, if the result of step S4 is that ignition has failed, the main power supply may be turned off in step S6 without reignition. In this case, the main power may be turned off and the operation on the day may be ended, but the main power may be turned on (turned on) again in step S7 and restarted. Therefore, when the main power is turned on again, the process proceeds to step S8, the ignition switch is turned on, and the process proceeds to the next step S9. In this step S9, for example, it is confirmed whether or not a predetermined time has elapsed with respect to a preset reference time, and if the result of the determination is affirmative (YES), the flow proceeds to step S10 to turn on the ignition means. In S11, normal combustion is performed. If the result of the determination in step S9 is negative (NO), that is, if the fixed time has not elapsed, the process returns to step S8 to turn on the ignition switch.

  After the main power is turned on again in step S7, the operation of turning on the ignition switch in step S8 may be skipped, and the process may directly proceed to step S9. Further, after the normal combustion is performed in step S5, the gas burner 16 is extinguished in step S12, and after reignition is performed in step S13, the process may proceed to step S6 to turn off the main power supply. At this time, the main power supply may be turned on (turned on) again in step S7, and the process may proceed to step S8, or may skip step S8 and proceed to step S9.

  As described above, according to the control method of the fifth embodiment, when the power is turned off without re-ignition when the ignition fails, even if the ignition is instructed at the next power-on, "a certain time" has elapsed since the power-on. Is controlled so as to ignite only after elapse of the expiration, so that the explosion and ignition by the unburned gas remaining in the combustion chamber is eliminated. Here, the “certain time” may be a fixed time, or a time that changes due to the number of times of ignition failure, oil temperature, gas secondary pressure, elapsed time after extinguishing, wind speed around the fryer, and the like. Further, when the “certain time” changes depending on the state of the gas burner, either the state when the power is turned off or the time determined when the power is turned on (on) may be used. Except for the gas secondary pressure at the time of ignition, the time determined when the power is turned on (ON) is more preferable because explosion and ignition are close to each other.

(Modification of Embodiment 5)
As to the fifth embodiment described above, there are basically the same modifications, but different modifications in detail. Therefore, a description will be given below as modified examples 1 and 2.

(Modification 1)
In the fifth embodiment, when the ignition fails after the ignition instruction is issued, the main power supply is immediately turned off in step S6 of FIG. However, in the first modification, the main power is not turned off immediately after confirming the ignition failure, but is turned off before the "certain time" described above elapses and without re-ignition. did.

  That is, without re-ignition when the ignition fails, and by turning off the main power before a certain time elapses, at the next main power-on, even if the ignition instruction is given, Control is performed so that ignition occurs only after a certain period of time has elapsed since the main power was turned on. For this reason, the explosion ignition due to the unburned gas remaining in the combustion chamber does not occur, and when the main power supply is turned on and re-ignition is performed next time, ignition can be performed immediately, so that user dissatisfaction can be resolved.

(Modification 2)
The second modification is a slightly modified version of the first modification. That is, in the first modification, after "the main power is turned off before a certain time elapses and without re-ignition", the main power is turned off in step S7 in FIG. However, in the second modified example, "the main power is turned off before the lapse of a certain time and without relighting" is the same, but immediately before the main power is turned off, the lapse of a certain time (the remaining ) Is stored in the control circuit 32 of FIG. As a method of storing the remaining time, there is a method of storing the remaining time at every fixed time when a certain time elapses.

  That is, when the main power is turned off without re-ignition and before a certain time elapses when ignition fails, the elapsed time (remaining time) of a certain time is stored immediately before the main power is turned off. Then, even when an ignition instruction is given when the next main power supply is turned on, the ignition is controlled only after the remaining time of "a certain time" after the main power supply is turned on. For this reason, explosion ignition by the unburned gas remaining in the combustion chamber is eliminated. Further, when the main power supply is turned on next and re-ignition is performed, the ignition is performed immediately, so that user dissatisfaction can be resolved.

  14 oil storage tank, 16 gas burner, 54 oil temperature detecting means, 56 wind speed detecting means

Claims (5)

When the gas burner (16) is ignited, the pressure of the gas supplied to the gas burner (16) for heating the oil in the oil storage tank (14) is set to a secondary pressure lower than the primary pressure supplied during normal combustion. In the method of controlling the combustion of a gas fryer,
When the secondary pressure set at the time of the first ignition of the gas burner (16) is higher than a predetermined reference secondary pressure, the time until re-ignition due to ignition failure of the gas burner (16) is set longer,
When the secondary pressure set at the time of the first ignition of the gas burner (16) is lower than the predetermined reference secondary pressure, the time until reignition of the gas burner (16) is set to be short. A combustion control method for a gas fryer, comprising: When the gas burner (16) is ignited, the pressure of the gas supplied to the gas burner (16) for heating the oil in the oil storage tank (14) is set to a secondary pressure lower than the primary pressure supplied during normal combustion. In the method of controlling the combustion of a gas fryer,
When always detecting the temperature of the oil in the oil storage tank (14) by the oil temperature detecting means (54) and reigniting after failing to ignite the gas burner (16),
If the temperature of the oil detected by the oil temperature detection means (54) is higher than a predetermined reference temperature, the time until re-ignition due to the ignition failure of the gas burner (16) is set short,
When the oil temperature detected by the oil temperature detecting means (54) is lower than a predetermined reference temperature, the time until re-ignition due to the ignition failure of the gas burner (16) is set longer. Control method of gas fryer. When the gas burner (16) is ignited, the pressure of the gas supplied to the gas burner (16) for heating the oil in the oil storage tank (14) is set to a secondary pressure lower than the primary pressure supplied during normal combustion. In the method of controlling the combustion of a gas fryer,
When always detecting the wind speed around the gas burner (16) by the wind speed detecting means (56), and reigniting the ignition of the gas burner (16) fails,
When the wind speed detected by the wind speed detecting means (56) is higher than a predetermined reference wind speed, a time until re-ignition due to ignition failure of the gas burner (16) is set short,
When the wind speed detected by the wind speed detecting means (56) is smaller than a predetermined reference wind speed, the gas until the re-ignition due to the ignition failure of the gas burner (16) is set longer. Flyer combustion control method. When the gas burner (16) is ignited, the pressure of the gas supplied to the gas burner (16) for heating the oil in the oil storage tank (14) is set to a secondary pressure lower than the primary pressure supplied during normal combustion. In the method of controlling the combustion of a gas fryer,
If the elapsed time after extinguishing the gas burner (16) is shorter than a predetermined reference time, the time until the automatic reignition of the gas burner (16) is set shorter.
If the elapsed time after extinguishing the gas burner (16) is longer than the reference time, the time until the automatic reignition of the gas burner (16) is set to be longer. Combustion control method. When the gas burner (16) is ignited, the pressure of the gas supplied to the gas burner (16) for heating the oil in the oil storage tank (14) is set to a secondary pressure lower than the primary pressure supplied during normal combustion. In addition, if the ignition of the gas burner (16) fails, in the combustion control method of the gas fryer so as to automatically re-ignition after a function time has elapsed,
When the main power is turned off without re-ignition when the ignition fails, even if the ignition switch is turned on after the main power is turned on, the time that is the function has elapsed since the main power was turned on. A method for controlling combustion of a gas fryer, wherein automatic ignition is performed only afterwards.

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