Single-channel pressure spray pump head and dual-channel spray pump head
1. The working principle of the single-channel and dual-channel pressure of the spray pump head
The single-channel pressure spray pump head is also called a simple centrifugal nozzle. As the name implies, it uses the swirl in the nozzle to generate liquid rotation, accelerates the spraying of FFJ in the converging channel, and spreads the cone-shaped oil film, using the high-speed difference between the liquid and the outside air. Broken and atomized. The centrifugal force of the cyclone is used, so the cyclone is the key part. The swirl chamber and nozzle connected to the cyclone (sheet) are equally important. They can be integrated (collectively referred to as atomizers), or they can be separated into a single-piece combination.
There are two oil circuits (main and auxiliary oil circuits or primary and secondary oil circuits) in the dual-oil pressure spray pump head for oil supply. When the fuel supply of the combustion chamber is small, that is, under low working conditions (such as the engine slow-moving state), only the auxiliary oil circuit (one channel) supplies fuel. As the fuel supply increases, the fuel pressure rises to a certain value. The oil separation valve (spring valve) inside or outside the nozzle is opened, and the main and auxiliary oil circuits supply oil at the same time. Dual-channel is an improved type of single-channel pressure spray pump head. Its outstanding advantages are that the oil volume adjustment range is large, and it can ensure low operating conditions (low oil supply). Due to the small diameter of the nozzle of the auxiliary oil channel, the oil pressure can still be Higher, can obtain better atomization quality (especially for the nozzle with dual-channel dual-chamber and dual-nozzle, and can reliably improve the swirl velocity for the dual-channel single-jet nozzle), which can meet the different working conditions of aviation gas turbines at high and low altitudes. Requirements for stable combustion and complete combustion. Therefore, two-way nozzles are widely used in aviation gas turbines, and are also widely used in ground gas turbines.
2. Structural characteristics of single-channel and dual-channel pressure of spray pump head
The single-channel pressure spray pump head has simple structure and good atomization quality. It is widely used in various types of combustion devices. Although the oil volume adjustment ratio range is small, it has been widely used in aircraft afterburners. Currently, it is widely used in the main combustion chamber. It is still used as the starting nozzle and the working nozzle, and the combined atomization device of the high-performance aviation gas turbine is used as the core nozzle. In addition, the pressure atomization method on non-combustion equipment, such as spray drying equipment, also uses a single-channel pressure spray pump head. It is also used in burners (or burners) on industrial furnaces and boilers.
There are many structural forms of dual-channel pressure spray pump heads. Here we introduce three types of spray pump heads: dual-channel single-chamber single-jet nozzle, dual-channel dual-chamber single-jet nozzle, and dual-channel dual-chamber dual-jet nozzle.
In order to accurately design and calculate the single-channel pressure spray pump head and the dual-channel spray pump head, the current design methods are based on the maximum flow principle method and the momentum equation method. In addition, we have developed or improved many design methods on this basis.