JPH01114663A - Forced circulation type burner - Google Patents

Abstract

PURPOSE:To prevent the stepout of a pump by setting a timer longer than die out detection delay time of a flame detector, stopping the combustion when no circulation can be detected during the combustion, starting a timer means, driving the pump continuously, and judging the detection status at the point of time up. CONSTITUTION:When no circulation can be detected due to some failure, a fuel valve 8 is adapted to be closed so that the combustion of a burner 7 will come to a stop immediately. At the same time, is started a timer means which is designed to set a timer longer than die out detection delay time determined by the characteristics of a flame detector 10. During the performance of the timer means, a detection status of a circulation detection means 4 is detected, then judged. When the circulation is detected, the operation returns to a combustion sequence, thereby starting the combustion of the burner 7 once again. In other words, the pump is kept driving before the time up of the timer means irrespective of the detection states of the flame detector 10. The detection status of a circulation detection means 4 is being judged. When no circulation is detected during the operation of the timer means, the detection status of the flame detector 10 is judged during the time up of the timer means.

Description

DETAILED DESCRIPTION OF THE INVENTION (-Field of Industrial Application) The present invention relates to forced circulation combustion devices such as forced circulation bathtubs and hot water heaters.

(Prior Art) In conventional forced circulation bathtubs, etc., a pump and circulation detection means such as a water flow switch are provided in the circulation path, and when circulation is detected after starting the pump, the burner is fired. If aMa is not detected during combustion, combustion is stopped to prevent dry firing. In cases where the burner's flame detector has a delay in detecting fire breakage, the flame detector is in the flame detection state immediately after combustion stops, so it is judged as an abnormal state, and the pump is also stopped and goes into standby mode. .

(Problem to be Solved by the Invention) However, the delay in the flame detector's detection of flames is resolved in a short period of time, and the pump is started again when the flame detector goes into a state where no flame is detected. There was a problem in that the pump stopped and started within a very short period of time, which caused the pump to step out.

The present invention solves the above-mentioned conventional problems, and provides a forced WIEI system that prevents the pump from stepping out due to the delay in detection of the flame detector.
The purpose is to provide type combustion equipment.

(Means for Solving the Problems) In order to achieve the above object, the present invention has the following configuration. That is, in a device that has a pump and a circulation detecting means in the wi loop and controls the burner and the pump based on the detection state of a flame detector of the burner and the circulation detecting means, the flame detector detects a ignition. A timer means with a timer time longer than the delay time is provided, and if circulation is not detected during combustion, the combustion is stopped, and the pump continues to be driven regardless of the flame detection state during operation, and at the time of time-up, the combustion is stopped. A control sequence is provided to determine the detection state of the flame detector.

(Example) Fig. 2 is an overall configuration diagram of the forced circulation type combustion apparatus according to the present invention, and the wil! The circuit (2) is provided with a pump (3) and circulation detection means (4) such as a water flow switch. (5) is a heat exchanger, and (6) is a hot water temperature detector. (7) is a burner, (8) is a fuel valve of the burner (7), (9) is an igniter, (10) is a flame detector, (
11) is a controller that controls various functions of the forced circulation combustion apparatus according to a predetermined control sequence.

FIG. 1 shows the main part of the control sequence, and the following explanation will be based on this control sequence.

First, the pump (3) is started and Il! ! ! I detection means (
4) starts the combustion sequence when it detects circulation. That is, when the fuel valve (8) is opened, the igniter (9) is operated to ignite the burner (7), and when the flame detector (IO) detects a flame, the fuel valve (8) is maintained in the open state. Ru.

Combustion continues until the hot water temperature detector (6) detects a preset temperature. For some reason during combustion, Wm
When it is not detected, the fuel valve (8) is closed and the combustion of the burner (7) is immediately stopped. A timer means set to a long timer time is activated (Fl). Note that the timer means is formed within the controller (11) and uses, for example, a capacitor timer circuit or a microcomputer. While the timer means is operating, the detection state of the circulation detection means (4) is determined, and if circulation is detected, the combustion sequence is returned to and the burner (7) starts combustion again. That is, before the timer means times up, the pump (3) remains driven regardless of the detection state of the flame detector (1G), and W! The detection state of the ll detection means (4) is determined. If no flame is detected during the operation of the timer means, the detection state of the flame detector (lO) is determined when the timer means times out. At this time, there is no false detection due to a delay in the detection of flame breakage by the flame detector (10), so if the flame detector (10) is normal, it will be in a flame non-detection state and return to the initial state after starting the pump (3). The detection state of the circulation detection means (4) is determined. On the other hand, if the flame detector (lO) is in the flame detection state, the pump (
3) may be stopped.

In any case, the operation of stopping and starting the pump due to the delay in detection of fire by the flame detector is prevented, and it is possible to reduce the possibility of pump out-of-step.

(Effects of the Invention) The present invention has the following excellent effects. In other words, in the forced circulation type combustion apparatus, it is possible to prevent the pump from stopping and starting and the accompanying pump out-of-step caused by a delay in the detection of ignition by the flame detector.

[Brief explanation of the drawing]

FIG. 1 is an operation flow diagram of a control sequence showing an embodiment of the present invention, and FIG. 2 is an overall configuration diagram of a forced circulation combustion apparatus according to the present invention. (2)...W1 loop (3)...Pump (4)...Circulation detection means (7)...Burner (lO)...Flame detector

Claims (1)

[Claims] In a device that has a pump and a circulation detection means in a circulation path, and controls the burner and the pump based on the detection state of a flame detector of the burner and the circulation detection means, the detection delay time of the flame detector A timer means having a long timer time is provided, and when no circulation is detected during combustion, the combustion is stopped and the timer means is activated, and while the timer means is in operation, regardless of the detection state of the flame detector. A forced circulation combustion device characterized by providing a control sequence that continues to drive a pump and determines the detection state of a flame detector at the time of time up.