JPS60228806A - Starting method of combustion device with burners making pair - Google Patents

Abstract

PURPOSE:To enable to reduce the number of times of ignition failures during the transient period shifting to the stable combustion, in which the pressure fluctuation occurs in inverse phase, by a method wherein at least predetermined time differences are provided to the arrivals of mixtures to the combustion chambers of respective burners at the starting of combustion. CONSTITUTION:An air supply part 17 is arranged at a position, the distances from which to the combustion chambers 14, 15 and 16 of burners 11, 12 and 13 and to the combustion chambers 14', 15' and 16' of burners 11', 12' and 13' respectively making a pair to the burners 11, 12 and 13 in the order named are different, at an air supply side manifold 18 so as to provide at least predetermined time differences to the arrivals of mixtures to the combustion chambers of the burners, which makes a pair, at the start of combustion. After the pressure fluctuation, the phase of which is inverse to the phase of the pressure fluctuation in the combustion chambers 14, 15 and 16, is developed in the combustion chambers 14', 15' and 16' as the result of the pressure fluctuation in the combustion chambers 14, 15 and 16, which is developed by the ignition of mixture arrived earlier at the combustion chambers 14, 15 and 16 than that at the combustion chambers 14', 15' and 16', is developed in the combustion chambers 14', 15' and 16', the mixture is arrived due to said time difference to the combustion chambers 14', 15' and 16' and ignited, resulting in easily developing the stable combustion, in which the pressure fluctuation occurs in opposite phase at the burners in pairs.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for starting a combustion apparatus having a pair of combustors.

A pair of combustors having the same resonance frequency are connected by a manifold on the intake side and the exhaust side, and each combustor is combusted with pressure fluctuations in opposite phases with a phase shift of 1800 degrees, thereby achieving pulse combustion, etc. Combustion devices that suppress noise during unsteady combustion are known. When starting such a combustion device, the air-fuel mixture in each combustion chamber is ignited by a spark plug installed in each combustion chamber, but if both combustion chambers are ignited at the same time or with a very short time difference, As shown in part a of FIG. 1, both pressure fluctuations collide in the exhaust manifold, so stable combustion with anti-phase pressure fluctuations does not occur and misfire occurs. In the conventional starting method, when such ignition trials are repeated, it is only when the ignition in each combustion chamber is performed with a time difference of more than a certain time that the out-of-phase pressure fluctuation is detected, as shown in part b of Figure 1. Since the combustion is to proceed, the number of misfires until a stable combustion state is reached is as high as, for example, 6 to 8 on average. Attempts have been made to create a time difference by controlling the ignition in each combustion chamber using spark plugs installed in each combustion chamber, but in addition to being extremely difficult to control, the ignition is delayed. There are many disadvantages such as difficulty in ignition normally due to the large amount of air-fuel mixture entering the combustion chamber.

The present invention overcomes these conventional drawbacks. The purpose of this invention is as follows, and will be described in detail below based on examples.

Symbols 1 and 1' are a pair of combustors, 2 and 2' are combustion chambers,
3.3' is an exhaust pipe. The combustor 1, 1' is the combustion chamber 2
, 2' and the exhaust pipes 3, 3' constitute, for example, a Helmholtz resonance system, and the resonance frequencies thereof are made to be the same. This pair of combustors 1, 1' are connected by manifolds 4, 4' on the intake side and the exhaust side, and each combustor 1, 1' is configured to burn in a state of pressure fluctuations in opposite phases. do. code 5
6 is an air-fuel mixture supply part provided in the intake manifold 4, 6 is an exhaust part provided in the exhaust manifold 4, and 7 and 7' are spark plugs provided in the respective combustion chambers 2 and 2'. Therefore, the present invention provides the air supply section 5 at different distances t and t' from the combustion chambers 2 and 2' of the respective combustors 1 and 1', so that the distances t and t' from the combustion chambers 2 and 2' of the respective combustors 1 and 1' are different. . After a pressure fluctuation occurs in the combustion chamber 2' on the other side in a phase opposite to that of the combustion chamber 2 on the other side, the air-fuel mixture is caused to reach the combustion chamber 2' on the other side, and the air-fuel mixture is ignited. It is characterized by the following.

The specific configuration of the air supply section 5 and the air supply side manifold 4 and the installation position of the air supply section 5 may be implemented as shown by the solid line and the two-dot chain line in FIG. In addition to examples, any other appropriate information may be used.

However, when the air-fuel mixture that has reached the combustion chamber 2 on one side before the combustion chamber 2' on the other side is ignited at point 0 in FIG. It propagates to the after-combustion chamber 2', and therein the combustion chamber 2', for example, de of FIG.
As shown in C, pressure fluctuations occur in the opposite phase to the combustion chamber 2. Then, after the pressure fluctuations in the opposite phase to the combustion chamber 2 have occurred, the air-fuel mixture reaches the combustion chamber 2' due to the above-mentioned time difference, so this mixture is ignited in synchronization with the pressure fluctuations in the opposite phase. Pressure fluctuations caused by ignition in both the burning chambers 2 and 2' do not collide at the exhaust side manifold 4', and
Immediately shifts to combustion with stable anti-phase pressure fluctuations. In this way, the method of the present invention can significantly reduce the number of misfires until a stable combustion state is achieved, to an average of 0 to 1.

The difference in time between the arrival of the air-fuel mixture to the combustion chambers 2 and 2' at the time of startup is due to the fact that, as mentioned above, the pressure fluctuations caused by the ignition propagate after the air-fuel mixture reaches the combustion chamber 2, and the combustion The time may be set appropriately as long as it is longer than the time required for a pressure fluctuation in the opposite phase to that in the combustion chamber 2 to occur in the combustion chamber 2'. In addition to being set to be performed within the first cycle of , it is also possible to set it to be performed within more than one cycle, for example, within several cycles or more.

Although a pair of combustors have been described above, the present invention can also be applied to multiple pairs of combustors, as described below. That is, FIG. 4 shows a plurality of pairs of combustors 11, 11'; 12° 12'; 13, 13 having the same resonance frequency.
'... are connected by manifolds 18, 18' on the intake side and the exhaust side, and both combustors 11, 11'; 12, 12'; 13, 13 in each pair ' is a combustion apparatus configured to combust in a pressure fluctuation state of opposite phase. 14°15.16 and the combustor 11' on the other side,
12', 13' combustion chambers 14', 15', 16'
The air supply parts 17 are provided at different distances from the combustion chambers on the one side and the other side at the time of starting. 4, 15
, 16; 14'.

A time difference of more than a predetermined time is provided for the arrival of the air-fuel mixture to 15' and 16'. Therefore, the pressure fluctuation due to ignition in the combustion chamber 14, 15, 16 on one side, where the air-fuel mixture reached first, propagates to the combustion chambers 14', 15', and 16' on the other side, causing the combustion chamber 14' to reach the combustion chamber 14'. , 15', 16', the combustion chamber 14
．． 15.16 and the opposite phase pressure fluctuations occur, that is, after the combination of opposite phase pressure fluctuations in each pair is established,
Due to the time difference, the combustion chamber 14'.

By allowing the air-fuel mixture to reach the air-fuel mixtures 15' and 16' and igniting these air-fuel mixtures, combustion with stable anti-phase pressure fluctuations can be easily generated.

As described above, the present invention connects a pair or a discrete pair of combustors having the same resonance frequency with a manifold on the intake side and the exhaust side, and burns each combustor with pressure fluctuations in opposite phases. In this configuration, by providing a time difference of more than a predetermined time for the air-fuel mixture to reach the combustion chamber of each combustor during startup, a time difference is created for ignition in each combustion chamber, which eliminates the drawbacks of the conventional method. The major feature of this method is that it can effectively prevent misfires caused by collisions of simultaneously ignited pressure fluctuations, and can significantly reduce the number of misfires until combustion with stable antiphase pressure fluctuations occurs. Thus, the present invention has the great feature that it is possible to extremely easily and reliably start a combustion apparatus that causes a pair of combustors to combust with pressure fluctuations in opposite phases.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram showing the pressure fluctuation state at the time of starting in the conventional case, and FIG. 2 and FIGS. Figure 4 (
b) is an explanatory view taken along the line X--X of (a), and FIG. 6 is an explanatory view showing the pressure fluctuation state at the time of starting in the present invention. Code 1.1', 11.11', 12.12', 13°1
3'...Combustor, 2.2', 14.14', 15.1
5'. 16, 16'... combustion chamber, 3, 3', 19.
・Exhaust pipe, 4.4', 18.18'... Manifold, 5.17... Air supply section, 6, 20... Exhaust section, 7.
7'...Spark plug. Applicant Tokyo Gas Co., Ltd. Agent Koji Sanse] Mef Tobakatsuo

Claims (2)

[Claims] (1) A pair of combustors having the same resonant frequency are connected by a manifold on the intake side and the exhaust side, so that each combustor burns in a pressure fluctuation state of opposite phase, and the intake air The side manifolds are provided with air supply sections at different distances from the combustion chambers of the respective combustors, and a time lag of more than a predetermined time is established for the air-fuel mixture to reach each combustion chamber at the time of startup. The pressure fluctuation due to ignition in the combustion chamber on one side, where the air-fuel mixture reached first, propagates to the combustion chamber on the other side, and the pressure fluctuation in the combustion chamber on the other side is in the opposite phase to that of the combustion chamber on the other side. A method for starting a combustion apparatus having a pair of combustors, characterized in that after the combustion occurs, the mixture reaches the combustion chamber on the other side and ignites the mixture. (2) A configuration in which multiple pairs of combustors having the same resonance frequency are connected by a manifold on the intake side and the exhaust side, and both combustors in each pair are combusted with pressure fluctuations in opposite phases. At the same time, the air supply side manifold is provided with an air supply section at a position where the distance from the combustion chamber of one side combustor and the combustion chamber of the other side combustor in each pair is different,
At the time of starting, a time difference of more than a predetermined time is set between the arrival of the air-fuel mixture to the combustion chambers on one side and the other side, and due to this time difference, the pressure fluctuation due to ignition in the combustion chamber on one side, where the air-fuel mixture arrived first, is reduced to the combustion chamber on the other side. After propagating to the combustion chamber and causing a pressure fluctuation in the combustion chamber on the other side that has a phase opposite to that of the combustion chamber on the other side, the air-fuel mixture reaches the combustion chamber on the other side and ignites the air-fuel mixture. A method for starting a combustion apparatus having a pair of combustors, characterized in that: