JPH0443215A - Gasification type combustion device - Google Patents

Abstract

PURPOSE:To prevent an abnormal combustion by a method wherein when an abnormal state occurs in a resistance value of a thermo-sensitive resistor element to cause an electrical energization for a gasification device heater to be stopped, this state is positively detected and a combustion operation is stopped. CONSTITUTION:As a gasification device temperature is lower than a predetermined temperature To during a combustion operation, a relay 3 is turned on and its normal-opened contact point 3m is closed, so that an electrical energization for a gasification device heater 5 is carried out. In addition, a timer 11 is cleared. As the temperature exceeds the predetermined temperature To, the electrical energization for the gasification device heater 5 is stopped. A timer 11 starts to perform a time counting operation. In this way, the temperature of the gasification device is kept near the predetermined temperature and gasification of kerosene is normally carried out. However, if an abnormal state occurs in a thermistor 12 and this thermistor exhibis a resistance value set in case that it detects a value more than the predetermined temperature To irrespective of the fact that the temperature of the gasification device is lowered than the predetermined temperature To, the timer 11 continues its non-cleared state and then the timer reaches a specified time TMo. In this way, a combustion operation is positively stopped and then an abnormal combustion caused by a reduction in temperature of the gasification device 4 is prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial Application Field) The present invention relates to a vaporization type combustion apparatus equipped with a vaporizer that vaporizes liquid fuel.

(Prior art) A vaporization type combustion device is equipped with a vaporizer with a built-in vaporizer heater, and before the start of combustion operation, the vaporizer is heated by the vaporizer heater, and the temperature of the vaporizer reaches a predetermined temperature is detected. When detected by a heat-sensitive resistance element such as a thermistor, liquid fuel is discharged from the tank.
For example, kerosene is supplied to a vaporizer and vaporized, and the vaporized gas is mixed with air and sent to a burner where it is ignited to start a combustion operation.

In such a vaporization combustion device, if the temperature-sensitive resistance element is disconnected or short-circuited, the vaporizer temperature cannot be maintained near a predetermined temperature, causing the vaporizer temperature to drop or reach a high temperature state. Since abnormal combustion occurs, safety measures have been taken to detect if the temperature-sensitive resistance element is disconnected or short-circuited and to stop the combustion operation.

(Problem to be Solved by the Invention) As described above, in conventional devices, safety measures have been taken against disconnection and short-circuiting of the temperature-sensitive resistance element, but if the resistance value of the temperature-sensitive resistance element becomes abnormal, for example, the vaporizer If the resistance value of the temperature-sensitive resistance element is detected to be higher than the predetermined temperature even though the temperature of the vaporizer is low, the vaporizer heater will not be energized even though the vaporizer temperature is low. .

By the way, the carburetor is heated to some extent by the heat recovered from the burner during combustion operation, but the recovered heat alone is not sufficient to maintain the specified temperature. It is designed to be heated.

Therefore, if an abnormality occurs in the resistance value of the temperature-sensitive resistance element and the power supply to the vaporizer heater is stopped, there is a problem that the vaporization of the kerosene by the vaporizer becomes insufficient and abnormal combustion occurs.

Therefore, the present invention makes it possible to reliably detect when an abnormality occurs in the resistance value of the temperature-sensitive resistance element and stop the power supply to the vaporizer heater, and to stop the combustion operation. The present invention aims to provide a vaporization type combustion device that can prevent abnormal combustion due to abnormal resistance values.

[Structure of the Invention] (Means for Solving the Problem) The invention corresponding to claim (1) heats the vaporizer in advance with a vaporizer heater, detects the temperature of the vaporizer with a temperature-sensitive resistance element, and performs vaporization. When the temperature-sensitive resistance element detects that the chamber temperature has reached a predetermined temperature, liquid fuel is supplied to the vaporizer and vaporized, and the vaporized gas is burned in the burner, while the temperature-sensitive resistance element detects the vaporizer temperature. In a vaporization combustion device that controls the energization and de-energization of the vaporizer heater so that the vaporizer temperature maintains approximately a predetermined temperature, the time during which the vaporizer heater is not energized after the start of combustion operation is counted, and the vaporizer heater is The combustion engine is equipped with a timer that is cleared when energization is started, and a control means that controls the combustion operation to stop when the timer counts a predetermined period of time or more.

The invention corresponding to claim (2) includes an energization rate detection means for determining the energization rate to the vaporizer heater within a predetermined time after the start of the combustion operation, and an energization rate detected by the energization rate detection means is set in advance. A control means is provided for controlling the combustion operation to stop when the combustion temperature decreases below a certain value.

(Function) In the invention corresponding to claim (1), even though an abnormality occurs in the resistance value of the temperature-sensitive resistance element and the vaporizer temperature has decreased after the combustion operation has started, the temperature-sensitive resistance element If the resistance value of is detected to be higher than a predetermined temperature, the vaporizer heater will continue to be de-energized, so a timer will count the continuous de-energization state of the vaporizer heater, and the counting time will be set for a certain period of time. When the temperature exceeds the limit, the combustion operation is controlled to stop.

In the invention corresponding to claim (2), even though an abnormality occurs in the resistance value of the temperature-sensitive resistance element and the vaporizer temperature decreases after the combustion operation is started, the resistance value of the temperature-sensitive resistance element is reduced. When a detection state occurs in which the temperature is higher than a predetermined temperature, the energization rate of the vaporizer heater within a predetermined period of time decreases. However, when the energization rate falls below a certain value, it is determined that an abnormality has occurred in the resistance value of the temperature-sensitive resistance element, and the combustion operation is controlled to stop.

(Example) Hereinafter, one embodiment of the present invention will be described with reference to the drawings.

As shown in FIG. 1, a carburetor heater 5 for heating a carburetor 4 is connected to an AC power source 1 via an operation switch 2 and further via a normally open contact 3m of a relay 3.

Further, an input terminal of a full-wave rectifier diode bridge circuit 7 is connected to the AC power supply 1 via a step-down transformer 6. A smoothing capacitor 8 is connected to the output terminal of the diode bridge circuit 7, and an input terminal of a stabilizing circuit 9 is connected to the smoothing capacitor 8. A microcomputer 10 is connected to the output terminal of the stabilizing circuit 9.

The microcomputer 10 has a CPU inside.

ROM, RAM, I10 port, etc. are provided, and the RA
A timer 11 is provided in M.

A connection point between a thermistor 12, which is a temperature-sensitive resistance element for detecting the temperature of the vaporizer 4, and a resistor 13 is connected to a human input terminal 11 with an A/D conversion function of the microcomputer 10. The other end of the thermistor 12 is connected to the +V1 terminal, and the other end of the resistor 13 is grounded.

An input terminal of a driver 14 is connected to an output terminal 01 of the microcomputer 10, and an input terminal of a driver 15 is connected to an output terminal 02.

Each of the drivers 14 and 15 has an output inversion function, and the relay 3 is connected between the output terminal of the driver 14 and the +V2 terminal, and the output terminal of the driver 15 and the +V2 terminal are connected to each other.
An electromagnetic pump 16 for supplying kerosene to the vaporizer 4 is connected between the V2 terminal and the V2 terminal.

The microcomputer 10 is programmed to perform the control shown in FIG. That is, when started, each process A during standby and preheating is performed. In the preheating raw treatment, the vaporizer heater 5 is energized to heat the vaporizer 4.

When the combustion operation is started, the temperature of the carburetor 4 detected by the thermistor 12 is set to a predetermined temperature T. Compare with.

And the vaporizer temperature is T. If so, the relay 3 is turned on to clear the timer 11, and then various processes B necessary for the combustion operation are performed.

Further, if the vaporizer temperature≧To, the relay 3 is turned off and the timer 11 is operated to count. Next, it is checked whether the count time of the timer 11 is equal to or longer than a preset constant time TMO.

If it is a certain time TM that is opened at the time of counting, various processes B necessary for the combustion operation are performed. When the various processes B are completed, the routine returns to the various processes A.

Further, if the count time≧certain time TM, the combustion operation is stopped and extinguished. (Control means) In this embodiment having such a configuration, when the vaporizer temperature detected by the thermistor 12 becomes lower than a predetermined temperature T0 during combustion operation, the relay 3 is turned on and its normally open contact 3m is closed. Therefore, the vaporizer heater 5 is energized. The vaporizer 4 is thus heated and its temperature increases. Also, the vaporizer heater 5
When energization starts, the tar r711 is cleared.

Further, the vaporizer temperature detected by the thermistor 12 during the combustion operation is a predetermined temperature T. When this happens, the relay 3 is turned off and its normally open contact 3m is opened, so that the energization to the carburetor heater 5 is stopped. That is, the vaporizer heater 5 is in a non-energized state. This causes the vaporizer temperature to gradually decrease. Further, when the vaporizer heater 5 becomes de-energized, the timer 11 starts counting time.

When the thermistor 12 is normally changing its resistance value in accordance with the vaporizer temperature in this way, when the vaporizer temperature becomes lower than the predetermined temperature T0, the vaporizer heater 5 is energized, and the vaporizer temperature increases. Predetermined temperature T. When the temperature exceeds that level, the vaporizer heater 5 becomes de-energized, and the vaporizer temperature is maintained near a predetermined temperature.

Therefore, the vaporization of kerosene by the vaporizer 4 is performed normally. Further, the timer 11 is cleared before counting TMo for a certain period of time, so that the combustion operation is not stopped.

However, an abnormality occurred in the thermistor 12 and the vaporizer temperature fell to the predetermined temperature T. Even though the resistance value of the thermistor 12 is lower than the predetermined temperature T. If the resistance value is the same as when the above is detected, the timer 11 will continue to be in a state where it is not cleared.

Therefore, eventually the count time of the timer 11 becomes a certain period TM.
o. In this way, the combustion operation is reliably stopped, and abnormal combustion due to a drop in the temperature of the carburetor 4 is prevented.

Next, other embodiments of the present invention will be described with reference to the drawings.

The circuit configuration of this embodiment is basically the same as that in FIG.

However, timer 1 is stored in the RAM of the microcomputer 10.
1, an A timer, a B timer, and a C timer are provided.

The microcomputer 10 is programmed to perform the control shown in FIG. That is, when started, each process A during standby and preheating is performed.

When the combustion operation is started, the temperature of the carburetor 4 detected by the thermistor 12 is set to a predetermined temperature T. Compare with.

And the vaporizer temperature is T. If so, the relay 3 is turned on to count the time by the A timer and stop the time count by the B timer.

Roughly count the time using the C timer.

Also, if the vaporizer temperature ≧To, turn off relay 3 and
The timer counts the time and stops the time count by the A timer. Furthermore, time is counted by a C timer.

Next, the count time of the C timer and the preset predetermined time M. The count time of the C timer is the predetermined time M
. If the value is not exceeded, various processes B necessary for the combustion operation are performed, and when the various processes B are completed, the routine returns to various processes A.

Further, the count time of the C timer is a predetermined time M. If it exceeds, calculate the energization rate from the ratio of the B timer count time and the A timer count time, that is, the A timer/B timer,
The energization rate is a preset constant value X. Check whether the above is true or not. (Electrification rate detection means) and constant value X. If it is above, C timer, A timer, B
After each timer is cleared, various processes B necessary for the combustion operation are performed, and when these various processes B are completed, the routine returns to various processes A.

Also a constant value X. If it is smaller than , the combustion operation is stopped and the fire is extinguished. (Control means) In this embodiment having such a configuration, the carburetor temperature detected by the thermistor 12 during combustion operation is set to a predetermined temperature T.
When it becomes lower than o, relay 3 turns on and its normally open contact 3
Since m is closed, the vaporizer heater 5 is energized. At this time, timer A counts time and timer B stops counting time.

Also, the vaporizer temperature or a predetermined temperature T detected by the thermistor 12 during combustion operation. When this happens, the relay 3 is turned off and its normally open contact 3m is opened, so that the energization to the carburetor heater 5 is stopped. That is, the vaporizer heater 5 is in a non-energized state. At this time, the B timer counts the time, and the A timer stops counting the time.

In this way, the A timer counts the energizing time of the vaporizer heater 5, and the B timer counts the non-energizing time of the carburetor heater 5.

On the other hand, the C timer counts time both when the vaporizer heater 5 is energized and when it is not energized.

Then, the count time of the C timer is a predetermined time M.

When the value exceeds , the energization rate is determined from the ratio of the count times of the A timer and the B timer.

In this case, when the resistance value of the thermistor 12 is changing normally according to the vaporizer temperature, the A timer is activated because the vaporizer heater 5 is alternately energized and de-energized according to the change in the vaporizer temperature. The energization rate determined by the /B timer is relatively high and constant value X. be higher than Therefore, the combustion operation continues.

However, an abnormality occurred in the thermistor 12 and the vaporizer temperature fell to the predetermined temperature T. Even though the resistance value of the thermistor 12 is lower than the predetermined temperature T. If the above-detected condition continues, the vaporizer temperature reaches the predetermined temperature T. Even if the voltage drops further, the vaporizer heater 5 is not energized, so the count time of the A timer decreases, and conversely, the count time of the B timer increases.

Therefore, at this time, the energization rate is a constant value X. , the combustion operation is stopped.

Therefore, in this embodiment, the same effects as in the previous embodiment can be obtained.

[Effects of the Invention] As described in detail above, according to the present invention, when an abnormality occurs in the resistance value of the temperature-sensitive resistance element and the power supply to the vaporizer heater is stopped, this is reliably detected and the combustion operation is performed. Therefore, it is possible to provide a vaporization type combustion device that can prevent abnormal combustion due to an abnormality in the resistance value of the temperature-sensitive resistance element.

[Brief explanation of drawings]

1 and 2 show one embodiment of the present invention. FIG. 1 is a circuit diagram of the main part, FIG. 2 is a flowchart showing main part control by a microcomputer, and FIG. 3 is a diagram showing an embodiment of the invention. 2 is a flowchart showing main part control by a microcomputer in the embodiment. 3... Relay 4... Vaporizer, 5... Vaporizer heater, 10... Microcomputer, 11... Timer, 12... Thermistor (temperature sensitive resistance element). Applicant's agent Patent attorney Takehiko Suzue Figure 2

Claims (2)

[Claims] (1) The vaporizer is heated in advance by a vaporizer heater, and the temperature of the vaporizer is detected by a temperature-sensitive resistance element, and when the temperature-sensitive resistance element detects that the temperature of the vaporizer has reached a predetermined temperature, the Supply liquid fuel to the vaporizer and vaporize it,
A vaporization type in which the vaporized gas is burned in a burner, the temperature of the vaporizer is detected by the temperature-sensitive resistance element, and the vaporizer heater is controlled to be energized or de-energized so that the vaporizer temperature is maintained at approximately a predetermined temperature. The combustion device includes a timer that counts the non-energization time of the carburetor heater after the start of the combustion operation, and is cleared when the carburetor heater starts to be energized, and a timer that counts the non-energization time of the carburetor heater after the start of the combustion operation, and a timer that counts the non-energization time of the carburetor heater after the start of the combustion operation. A vaporization type combustion device characterized by being provided with a control means for controlling and stopping combustion operation when a count is counted. (2) The vaporizer is heated in advance by the vaporizer heater, and the temperature of the vaporizer is detected by a temperature-sensitive resistance element, and when the temperature-sensitive resistance element detects that the vaporizer temperature has reached a predetermined temperature, the temperature of the vaporizer is detected by the temperature-sensitive resistance element. Supply liquid fuel to the vaporizer and vaporize it,
A vaporization type in which the vaporized gas is burned in a burner, the temperature of the vaporizer is detected by the temperature-sensitive resistance element, and the vaporizer heater is controlled to be energized or de-energized so that the vaporizer temperature is maintained at approximately a predetermined temperature. In the combustion device, an energization rate detection means for determining the energization rate to the vaporizer heater within a predetermined time after the start of combustion operation, and an energization rate detected by the energization rate detection means is set from a preset constant value. 1. A vaporization type combustion device, characterized in that a control means is provided to control the combustion operation to stop when the temperature decreases.