JPH0335960Y2 - - Google Patents

Description

[Detailed description of the invention] (Field of industrial application) This invention improves the ignition performance at extremely low temperatures in a combustor using an oil gasification burner without increasing the pre-purge time under normal conditions. This invention relates to an ignition control circuit for an oil combustor.

(Prior Art) Conventionally, in a heating machine using an oil gasification burner, a heater is usually used to gasify oil. In order to improve the ignition performance at low temperatures, as shown in Figure 4, the pre-purge time t, which is started after the temperature has been raised to a predetermined temperature by the heater, is lengthened to open the path of the vaporized gas. The method used is to raise the temperature to a sufficiently high temperature before igniting it.

However, conventionally, this pre-purge time t is usually fixed at a predetermined time, and in order to improve the ignition performance at extremely low temperatures, if the pre-purge time t is set according to the extremely low temperatures, In the lower case, there is a problem that the pre-purge time t becomes unnecessarily long and the ignition time takes a long time.

(Purpose of the invention) The present invention was made in consideration of the above circumstances, and is an oil combustor that improves ignition performance at extremely low temperatures without increasing the pre-purge time under normal conditions. The purpose is to provide an ignition control circuit for.

Structure of the invention In order to achieve the above-mentioned object, the ignition control method for a combustor according to the invention detects the internal temperature of the carburetor and performs pre-purge when the temperature of the carburetor is raised to a predetermined ignition starting temperature by the heater. After the start of prepurge, when the internal temperature of the vaporizer reaches a predetermined starting temperature, if the shortest prepurge time has elapsed, the prepurge is finished and ignition is started.

The pre-purge start temperature may be at least a temperature required to gasify petroleum. Therefore, the ignition start temperature only needs to be equal to or higher than the prepurge start temperature.

Embodiment 1 An embodiment of the present invention will be specifically described below based on the drawings.

FIG. 1 is a flowchart showing the flow of ignition control of a combustor according to an embodiment of the present invention, and FIG. 2 is a temperature chart showing changes in the internal temperature of the carburetor over time. FIG. 3 is a block diagram of the ignition control circuit.
1 is a vaporizer temperature detector, 2 is a shortest prepurge timer, and 3 is a prepurge time setting circuit.

When the switch is turned on F1, electricity starts flowing to the heater built into the vaporizer that gasifies oil, and F2 is turned on.
The internal temperature T of the vaporizer increases. This internal temperature T
The rate of increase in is determined by the ambient temperature and heater capacity. When the internal temperature T of the vaporizer rises to a predetermined pre-purge start temperature T1 necessary for gasifying oil, F3, pre-purge is started.
4. After this, the shortest prepurge time has passed and F5,
When the internal temperature T of the carburetor becomes equal to or higher than a predetermined ignition start temperature T3 at which ignition can be started, F6, pre-purge is ended F7, and ignition operation is started F8. For the ignition operation, for example, a spark is emitted toward a burner (not shown), and a fuel pump supplies gasified oil to the burner via a vaporizer. The supply of electricity to the heater is stopped when the internal temperature T of the vaporizer reaches a predetermined heating end temperature T2 or higher, and is restarted when the internal temperature T of the vaporizer becomes lower than a predetermined prepurge start temperature T1 necessary for gasifying oil. In this way, the internal temperature T of the vaporizer is maintained within a range of approximately the predetermined pre-purge start temperature T1 necessary for gasifying oil and less than the heating end temperature T2. In addition, when restarting the operation within a short time after the end of operation, if T≧T3, pre-purge is performed only for the shortest time to discharge residual gas.

Note that a temperature detection element such as a thermistor is used to detect the internal temperature T of the vaporizer.

In this way, since the end of pre-purge depends on the internal temperature T of the vaporizer, the pre-purge time can be extended or shortened depending on the ambient temperature. In other words, when the ambient temperature is low and extremely low, these times are sufficiently extended and the ignition performance is enhanced, while under normal conditions where the ambient temperature is relatively high, these times are shortened and ignition occurs within a short time. I can do it.

(Structure of the invention) As described above, the present invention detects the internal temperature of the vaporizer, starts pre-purge when the internal temperature of the vaporizer rises to a predetermined pre-purge start temperature by the heater, and When the internal temperature of the vaporizer reaches the ignition start temperature, the pre-purge ends and the burner is ignited, so at extremely low temperatures, the vaporizer is sufficiently heated to the specified ignition start temperature before being ignited. While performance can be improved,
Under normal conditions, the time required for the vaporizer to reach the ignition starting temperature is shortened, so the ignition time can be shortened.

[Brief explanation of the drawing]

Fig. 1 is a flow diagram of a combustor according to an embodiment of the invention, Fig. 2 is a temperature diagram showing changes in vaporizer temperature over time, Fig. 3 is a block diagram of the ignition control circuit, and Fig. 4 is a flow diagram of a combustor according to an embodiment of the invention.
The figure is a temperature diagram of a conventional example. 1... Vaporizer temperature detector, 2... Shortest prepurge timer, 3... Prepurge time setting circuit.

Claims (1)

[Scope of utility model registration request] It has a vaporizer temperature detector that detects the temperature of the vaporizer heated by the heater and a shortest pre-purge timer, and after the shortest pre-purge time has elapsed, if the internal temperature of the vaporizer is high, the pre-purge time is shortened, An ignition control circuit for an oil combustor, comprising a pre-purge time setting circuit that extends the pre-purge time when the internal temperature of the vaporizer is low.