JPS5862418A - Combustor - Google Patents

Abstract

PURPOSE:To prevent explosive combustion in case of the starting of combustion by mounting two injectors, valves thereof are opened at supply pressure, one part thereof is lower than the maximum combustion pressure, the remainder thereof is higher than the maximum combustion pressure and which is lower than the maximum fuel supply pressure and which inject fuel. CONSTITUTION:When ignition operation is conducted, fuel is injected instantaneously to result in ignition combustion because the valve only of a fuel injector 14 is opened first under the state of low pressure. When the supply pressure of fuel rises close to the maximum value with slight time delay, the valve of a fuel injector 15 is opened, and fuel injection is started at the full flow rate. Since combustion is already started through fuel injection from the fuel injector 14 in a combustion chamber 1 at that time, ignition in case of the injection of the full flow rate is rapidly conducted, and a large amount of fuel not burnt is not stored in the combustion chamber 1. Accordingly, the generation of sudden explosive combustion can be prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a combustion device, and more particularly to a secondary combustion device equipped with a fuel injector suitable for preventing the sudden start of explosive combustion that generates high-temperature, high-pressure gas.

First, a conventional combustion device will be explained using FIGS. 1 and 2. FIG. 1 is a system diagram of the entire device. The first
In the figure, the symbol (■) indicates a combustion chamber, which has a fuel injector 2 at one end of the combustion chamber l, and the other end is open to the atmosphere or nitrogen through a nozzle 3. 4 is a spark plug for ignition. The fuel injector 2 is connected via piping to a fuel tank 7 and an oxidizer tank 8 via a fuel tank Arai 5 and an oxidizer tank Arai 6, respectively, and the tank 7.8 is connected to a high pressure nitrogen tank 9 by piping. A supply pressure is provided to inject and atomize the fuel and oxidizer. In this device, when the ignition plug 4 is ignited and the Arai 5.6 is opened, the fuel and oxidizer are injected into the combustion chamber 1 and combust, forming a high temperature and large volume of gas. Since the outlet is constricted by the nozzle 3, the inside of the combustion chamber 1 has a high pressure, and a gas flow faster than the nozzle 3 is generated. Next, FIG. 2 is a sectional view of the fuel injector 2 of FIG. 1. In the figure, IO is a fuel supply pipe, 11 is a fuel injection hole, 12 is an oxidizer supply pipe,
13 is an oxidizing agent injection hole. In such a conventional combustion device, the amount of fuel Q when opening the shield wells 5 and 6 to start combustion is as follows: Cd2 flow coefficient A: nozzle hole area ρ: fluid passing through the nozzle hole Density P, is represented by: fuel supply pressure Po at the fuel injection valve section=pressure inside the combustion chamber 1, and Q is proportional to the square root J100K of the pressure difference before and after the nozzle hole. By the way, Pl is the value obtained by subtracting the fluid resistance loss of the fuel supply system from the original pressure of the nitrogen tank 9, and if the fluid resistance loss is very small compared to the magnitude of the original pressure, the fluid resistance loss due to the flow rate change is Since the change is also small, it can be assumed that Pl is maintained at a substantially constant value. On the other hand, Po is zero (gauge pressure) at the start of combustion. Therefore, during combustion, the pressure difference before and after the nozzle hole (P+-Pa)
is small, but the pressure difference at the start of combustion becomes Pl, which becomes a large value, so a large amount of fuel temporarily flows in at the start of combustion, and if the ignition delay is large, combustion starts explosively.
Not only will it make a loud noise, but it may also cause damage to the equipment. In addition, to prevent destruction,
If the combustion chamber 1 is made strong enough to withstand explosive combustion, problems arise such as increased weight and cost.

FIG. 3 is a system diagram of another conventional combustion apparatus designed to eliminate the above-mentioned drawbacks, and the same parts as in FIG. 1 are designated by the same reference numerals. In FIG. 3, a plurality of fuel injectors with small nozzle hole areas are provided as shown by 2 and 2', and each fuel injector 2 and 2' has a fuel injector 5.5' and an oxidizer. Shaarai wells 6 and 6' are provided, and at the start of combustion, some of the shield wells, for example, Sharai wells 5 and 6, are opened to start combustion with a small fuel flow rate, and after ignition, the other Sharai wells are sequentially opened. Try to bring it to full flow. However, in this case, there are disadvantages in that the number of shutters is large and a control device is required to open them one after another, making the device complicated.

The present invention has been made in view of the above, and its purpose is to provide a combustion device that can prevent explosive combustion from occurring at the start of combustion and does not complicate the device. be.

A feature of the present invention is that at least two fuel injectors are provided for supplying fuel to the combustion chamber, and each fuel injector is provided with a nine-needle valve that is provided with a closing force by a spring whose deflection can be adjusted to close the fuel injection hole. At the same time, a fuel supply chamber is provided around the valve surface of the needle valve, and the fuel supply pressure acting on the valve surface applies an opening force to the needle valve, and this opening force is greater than the closing force of the spring. The fuel supply pressure at which the pressure increases and starts injecting fuel is changed by adjusting the deflection of the spring, and some of the fuel injectors open and inject fuel at a fuel supply pressure that is lower than the maximum combustion pressure. However, the residual fuel injector is set to open and inject fuel at a fuel supply pressure that is higher than the maximum combustion pressure and lower than the maximum fuel supply pressure.

The present invention will be explained in detail below using the embodiments shown in FIGS. 4 and 5. FIG. 4 is a system diagram showing an embodiment of the combustion apparatus of the present invention. The same parts as in FIG. In FIG. 4, a fuel injector 14 according to the present invention is shown in place of the fuel injectors 2, 2' of FIG.
．． The fuel supply pipes 16 and 17 of the fuel injectors 14 and 15 are respectively connected to the fuel tank 7 via the fuel tank 7, and the oxidizer supply pipe 18.
19 are connected to the oxidizer tank 8 via the oxidizer tank Arai 6, respectively. Figure 5 shows the fuel injector 14 of Figure 4.
This is a sectional view showing one embodiment of the present invention, and the fuel injector 15 also has a similar structure. In FIG. 5, 16 is a fuel supply pipe;
1 is a fuel injection hole, 18 is an oxidizing agent supply pipe, and 2 is an oxidizing agent injection hole. By the way, the fuel injection valve section is closed by the needle valve n that is pressed by the spring n, and the closing force is applied by changing the position of the spring holder 6 using the adjustment spring to reduce the deflection of the spring n. This allows it to be changed and adjusted. A fuel supply chamber is provided on the valve face of the needle valve Z, and when the opening force of the needle valve n due to the fuel supply pressure acting on the valve face becomes stronger than the closing force due to the spring n, the needle valve phantom is separated from the fuel injection hole, and fuel is injected from the fuel injection hole into the combustion chamber 1 (see FIG. 4).

The fuel injector 15 has the same structure, but the valve opening pressure of the fuel injector 14, that is, the valve opening fuel supply pressure, is lower than the maximum combustion pressure generated in the combustion chamber 1, and moreover, the fuel injector 14 has the same structure. When Arai 5 is closed, the fuel injection hole (
b) has sufficient closing force to stop leakage from the
When the fuel well 5 opens and injects fuel, the deflection of the spring 5 is made such that the pressure is sufficient to provide the injection hole differential pressure necessary for atomization of the fuel until it is ignited. It is set. On the other hand, the deflection of the spring n is set so that the valve opening pressure of the fuel injector 15 is higher than the maximum combustion pressure and lower than the maximum fuel supply pressure. In other words, this set pressure must be set to be a pressure sufficient to provide the injection hole differential pressure necessary to atomize and supply fuel into the combustion chamber l, which has the highest combustion pressure. be.

According to the above configuration, when the spark plug 4 is ignited and the spark plugs 5 and 6 are opened, the fuel and the oxidizer flow into the fuel injectors 14 and 15, respectively, and the oxidizer flows into the respective oxidizers. The fuel is injected from the injection hole 21, but first, only the fuel injector 14 opens at low pressure, so fuel injection is started immediately to reach ignition combustion, and then fuel is supplied after a slight delay. When the pressure rises to near the maximum value, the fuel injector 15 opens and starts injecting fuel at full flow rate. At this time, combustion has already started in the combustion chamber l due to fuel injection from the fuel injector 14.
Ignition occurs rapidly when the full flow rate is injected, so that a large amount of unfueled fuel does not accumulate in the combustion chamber 1, and sudden explosive combustion can be prevented from occurring. Also,
Since this can be realized by only simple modification of the fuel injectors 14, 15, the device does not become complicated.

As explained above, according to the present invention, it is possible to prevent explosive combustion from occurring at the start of combustion, and there is an effect that the apparatus is not complicated.

[Brief explanation of drawings]

1 and 3 are system diagrams of a conventional combustion device, FIG. 2 is a sectional view of the fuel injector shown in FIG. 1, and FIG. 4 is a system diagram showing an embodiment of the combustion device of the present invention. FIG. 5 is a sectional view showing an embodiment of the fuel injector shown in FIG. 4. l... Combustion chamber, 5... Fuel Arai,
6... Oxidizing agent Arai, 14.15...
Fuel injector, addition...Fuel agent Patent attorney Usui
1) Kosai Toshi 1 illustration

Claims (1)

[Claims] 1. At least two fuel injectors supplying fuel to the combustion chamber
In the side-mounted combustion device, each of the fuel injectors is provided with a needle valve to which a closing force is applied by a deflection-adjustable spring that closes the fuel injection hole, and a fuel supply chamber is provided around the valve surface of the needle valve. is provided, and the opening force is applied to the needle valve by the fuel supply pressure acting on the valve surface, and the fuel supply pressure when the opening force becomes greater than the closing force by the spring and fuel starts to be injected is determined by the spring. some of the fuel injectors open and inject fuel at a fuel supply pressure lower than the maximum combustion pressure, and the remaining fuel injectors are higher than the maximum combustion pressure; A combustion device O characterized in that the valve is set to open and inject fuel at a fuel supply pressure lower than the maximum fuel supply pressure.