JPS6349122B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Technical Field The present invention relates to a liquid fuel vaporizing combustor.

<Prior art> In a liquid fuel vaporization combustor that gasifies liquid fuel in a vaporizer and combusts it in a burner, if poor quality fuel (altered kerosene, etc.) is used, or if normal fuel is used for a long period of time (more than one season) ) When heated, tar adheres and accumulates on the inner surface of the vaporizer, the vaporizing element, the nozzle, etc., resulting in changes in combustion conditions such as the original blue flame combustion becoming red flame combustion and a decrease in calorific value. was occurring. In order to eliminate this problem, it is enough to clean the vaporizer, but it is difficult to determine when to perform this cleaning, especially at the user level, and it is vaguely known as "1.
It was said to be done after the end of the season, ``when the combustion flames have gotten smaller,'' or ``when red flames appear.'' For this reason, it is quite possible that the appropriate time for cleaning will be missed, and more tar will accumulate than can be removed with one cleaning, resulting in cleaning being carried out for a long time.
It is assumed that it will be necessary to increase the number of times. If you clean at the right time, you can save time and frequency. What does cleaning mean here?
The vaporizer is heated to approximately 400℃ higher than the normal combustion control temperature.
The method is to maintain the temperature above the fuel level, stop the inflow of fuel, and instead send air into the carburetor to burn off the tar that has accumulated.

<Objects> In view of the above, an object of the present invention is to provide a liquid fuel vaporizing combustor that can reliably notify when it is time to clean tar attached to a vaporizer or the like and maintain a normal combustion state.

<Implementation> Hereinafter, one embodiment of the present invention will be explained based on FIGS. 1 to 6. This includes a vaporizer 1 for vaporizing liquid fuel, and a vaporizer 1 for pumping liquid fuel to the vaporizer. In a liquid fuel vaporizing type combustor comprising a feed pipe 2 and a burner 3 for burning the fuel vaporized in the vaporizer 1, a method for detecting the pressure of the fuel in the liquid fuel feed path A is provided. A pressure detector 4 is provided, and an alarm device 5 is provided that turns on when the detected value detected by the pressure detector 4 exceeds a pressure setting value in the feed path necessary to obtain a predetermined calorific value. There is. Further, a flame detector 8 such as a flame sensor is provided near the flame port 6 of the burner 3 to detect the state of the flame 7, and when the flame resistance value detected by the flame detector 8 exceeds a predetermined value. A determining means 9 is provided which determines this and generates a dry firing instruction signal P which turns on the notification device 5.

The flame detector 8 detects the resistance value between it and the burner 3 to determine ignition or misfire, but since the resistance value changes depending on the state of the flame, this can be used to detect the dry firing. It's about knowing the time. That is,
As shown in Figure 2, the flame resistance _A0 rapidly decreases from infinity at the time of ignition operation, drops below the ignition level before misfire judgment starts, detects ignition, and then reaches the level of strong combustion. In order to control the room temperature, as the amount of heat generated changes, the resistance value changes accordingly. However, although the calorific value has decreased, the flame resistance B falls below the ignition level after ignition, and although ignition is detected, the flame resistance B does not drop to the level during normal combustion during subsequent combustion. For example, during strong combustion, it is usually 3200Kcal/
There is a correlation between calorific value and flame resistance, as shown by the fact that when the flame resistance is 0.6 to 0.8 MΩ at R, the calorific value decreases to 1.5 to 2 MΩ at around 1500 Kcal/R. By detecting the change, it is possible to know the change in the amount of heat generated. The determining means 9 compares the flame resistance value with a preset value K and generates a dry firing instruction signal P.

The pressure detector 4 has a conventionally known structure,
It has a vertically swingable diaphragm that partitions the detection chamber inside the main body into upper and lower parts. Further, the notification device 5 includes, for example, a lamp 5a that lights up when the detected value exceeds the pressure setting value, and may also include a buzzer, chime, voice, digital display, etc. In the figure, 10 is a jet nozzle of the carburetor 1, 11 is an oil tank, 12 is an oil pan, 13 is an oil pump, 14 is a return pipe, and 15 is a solenoid valve.

In the above configuration, the liquid fuel is supplied to the fuel tank 1
1, the oil accumulates in a saucer 12, is pumped by a pump 13 through a pipe 2 into a vaporizer 1, is heated and vaporized there, and is ejected from a nozzle 10 to a burner 3.

By the way, when the liquid fuel is vaporized in the vaporizer 1, its volume expands, but since the nozzle 10 is the only outlet, the pressure in the vaporizer 1, the feed pipe 2, and the return pipe 14 increases. This pressure varies depending on the calorific value, nozzle diameter, control temperature of the carburetor 1, etc., but it is 1600 to 2000 during strong combustion.
mmAq, about 500 to 600 mmAq during weak combustion.

Here, the calorific value, vaporizer 1, feed pipe 2, return pipe 14
(hereinafter referred to as feed path A), the vaporizer 1 is new and the internal vaporizing element (not shown), nozzle 10, etc. are free of tar and are normal so that liquid fuel vapor can pass through smoothly. During combustion, under the same conditions, the greater the calorific value, the higher the pressure in the feed path A. However, due to long-term use or use of poor-quality kerosene, tar adheres to the inside of the vaporizer 1, the vaporization element, the nozzle 10, etc., and the passage of liquid fuel vapor becomes obstructed, and the vapor outlet is not controlled. As a result, the pressure in feed path A increases.

Next, an example of the control state of the combustor will be shown. In Fig. 2, the control first determines a misfire after igniting burner 3, then stabilizes the combustion by forcibly performing strong combustion for a certain period of time, and then starts determining whether ventilation is good or not. Normal heat generation control is performed. With this control operation, in the case of normal combustion A during forced strong combustion after ignition of the burner 3, there is no tar attached, so the flame resistance detected by the flame detector 8 is in the range of the A ₀ line, and the flame resistance Do not exceed the setting K. However, if tar adheres to the feed path and a constant calorific value cannot be obtained, the calorific value decreases to combustion B, and the flame resistance detected by the flame detector 8 becomes line B, exceeding the set value K. . Therefore, the determining means 9 generates a dry firing instruction signal P to turn on the notification device 5. Therefore, the notification device 5 is activated and displayed on the lamp 5a to inform the operator that it is time for cleaning. The same applies when replacing the vaporizing element etc. without cleaning, and when the tar content in the feed path A exceeds a set value, it is notified that it is time to replace the vaporizing element etc. In addition, by determining different set values K and K1 and outputting different signals, two-stage control can be performed: a lamp display during strong combustion and a lamp display during weak combustion, as shown in Figure 2. .

The dry firing time can also be notified by detecting the pressure in the feed path A with the pressure detector 4 and turning on the lamp 5a of the notification device 5.

The amount of heat generated can be easily determined by using part of the forced strong combustion time from the start of misfire determination to the start of ventilation determination, and if the flame resistance at this time is higher than the set value, it is determined that it is time for dry firing. and let them know.

A determining means for determining whether the flame resistance value is equal to or higher than a predetermined value is provided, and a notification device is provided that is turned on in response to a dry firing instruction signal sent by the determining means.

Therefore, according to the present invention, the presence or absence of tar adhesion in the feed path can be confirmed using the flame detector, the determination means, and the notification device, and the timing of cleaning can be notified, so that a normal combustion state can be maintained reliably.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of a liquid fuel vaporizing combustor showing an embodiment of the present invention, and FIG. 2 is a diagram showing the relationship between combustion time and flame resistance when the same calorific value is set. A: Conveyance path, 1: Vaporizer, 2: Conveyance pipe, 3: Burner, 4: Pressure detector, 5: Notification device, 8: Flame detector, 9: Judgment means.

Claims (1)

[Scope of Claims] 1. A liquid fuel comprising: a vaporizer for vaporizing liquid fuel; a pipe for pressure-feeding the liquid fuel to the vaporizer; and a burner for burning the fuel vaporized by the vaporizer. In the vaporization type combustor, a flame detector provided corresponding to the flame port of the burner, and a determining means for determining whether the output of the flame detector is equal to or higher than a predetermined value and generating a dry firing instruction signal. A liquid fuel vaporizing combustor comprising: