JPS593214Y2 - combustor - Google Patents

Description

[Detailed Description of the Invention] This invention relates to a combustor that burns a mixture of gaseous fuel and combustion air, a so-called premix combustor.

Generally, the combustion plate used in this type of combustor often has a large number of independent flame ports 8a in order to equalize the flame and stabilize combustion, as shown in FIG.

However, the flame on the combustion plate 8 cannot be a completely uniform flame because it is impossible to completely mix the gaseous fuel and the combustion air and to equalize the mixed gas speed at each flame port 8a. The heat received from the flame of the plate 8 (mainly radiant heat) is non-uniform on each side of the combustion plate, and the heat radiated from the combustion plate 8 is large at the periphery and low at the center, so the combustion plate has temperature unevenness. This generates thermal stress, which causes deformation and cracking during use.

The present invention provides a combustion plate that is less likely to crack or deform due to such thermal stress.

An embodiment of this invention will be described below with reference to the drawings.

Figure 1 shows a premix combustor, where 1 is the gaseous fuel inlet, 2
5 is a combustion air inlet, and 5 is a mixing chamber surrounded by a bottom wall 3 and side walls 4, in which gaseous fuel and combustion air are mixed.

Reference numeral 6 denotes a rectifier plate provided to close the upper part of the mixing chamber 5, which has small holes 6a uniformly in order to equalize the blowing speed of the mixed gas.

Reference numeral 7 denotes a wire mesh sandwiched between the rectifying plate 6 and the combustion plate 8, which equalizes the blowing speed of the mixed gas and prevents the flame from backfiring into the mixing chamber 5.

Reference numeral 8a designates a large number of independent flame ports provided on the combustion plate, which form a flame 10 in the combustion chamber 9 above.

FIG. 3 shows an embodiment of the combustion plate of the present invention, in which slits 11 extend radially from the center of the combustion plate 8 to a position slightly before the outer peripheral edge, and communicate with each other at the center.

Next, the effect will be explained.

Consider the temperature of the combustion plate 8 during combustion.

The heat received is heat (mainly radiant heat) received from the flame 10, which differs in each part due to the difference in temperature and size of the flame generated due to the concentration of the mixed gas and the non-uniform speed when passing through the flame port 8a.

Next, the heat radiation occurs when the mixed gas hits the combustion plate 8 and the flame opening 8a
, which is taken away by the mixed gas when passing through, and what is taken away by the side wall 4.

Therefore, as shown in FIG. 5, the temperature distribution on the combustion plate 8 is higher at the center and lower at the periphery, causing a difference in thermal expansion between the center and the periphery, causing thermal stress. Deformation and cracking may occur during use.

However, in this invention, the combustion plate 8 has radial slits 11.
Since the slit opening area per unit area of the combustion plate 8 is increased from the periphery to the center, the slit 11 can absorb the difference in thermal expansion, that is, thermal stress, and prevent deformation and cracking. This makes it less likely to occur.

FIG. 4 shows another embodiment, in which each burner port 8a is shown in the figure.
A similar effect can be obtained by radially connecting them with slits 11.

Further, although this invention has been described using only a circular combustion plate 8, the same applies to a rectangular combustion plate.

As described above, this invention is characterized in that the combustion plate is provided with radial slits extending from the center toward the periphery and communicating with each other at the center.

By the way, the temperature distribution of the combustion plate is maximum at the center and decreases toward the periphery.As a result, the maximum thermal expansion occurs at the center, and the amount of expansion decreases toward the periphery. However, in this design, the slits are provided as mentioned above, so the snot opening area per unit area of the combustion plate increases from the periphery to the center, which causes a large amount of thermal expansion. Even in the central portion, the amount of thermal expansion can be sufficiently absorbed by the slit, and the occurrence of deformation and cracking due to thermal stress in the combustion plate can be suppressed.

[Brief explanation of drawings]

Fig. 1 is a sectional view showing a premix combustor, Fig. 2 is a plan view showing a conventional combustion plate, Fig. 3 is a plan view of a combustion plate showing an embodiment of this invention, and Fig. 4 is a plan view showing this invention. FIG. 5 is a plan view of a combustion plate showing another embodiment, and FIG. 5 is a temperature distribution diagram at each part of the combustion plate. In the figure, 1 is a gas fuel population, 2 is a combustion air inlet, 5 is a mixing chamber, 8 is a combustion plate, and 11 is a slit. Note that the same reference numerals in the figures indicate the same or corresponding parts.

Claims (1)

[Scope of utility model registration request] The combustion plate includes a combustion plate having a large number of flame ports, and burns a mixture of gaseous fuel and combustion air on the combustion plate, and the combustion plate includes a combustion plate extending from a central portion to a peripheral portion of the combustion plate;
A combustor characterized by having radial slits that communicate with each other in the center.