Designers from Voronezh KB Khimavtomatiki have developed a liquid rocket engine chamber in which its own fuel is simultaneously used to cool the gas duct. After passing through special channels, the heated fuel is directed to pressurize the rocket's tank, so a separate heat exchange unit is not required for the design.
The gas duct is proposed to be manufactured using an additive method, forming a system of expanding and contracting channels inside it. The fuel passes through them according to a “co-current-counter-current” scheme, taking heat from the walls.
According to calculations, this scheme allows for a pressure of 300–350 atmospheres in the gas duct and a generator gas temperature of up to 1500 K, which is approximately 1227 °C.
At the same time, the fuel heated after cooling is not discarded. It enters the tank cavity and is used for its pressurization. This should simultaneously increase the engine's energy characteristics, reduce its mass, and decrease manufacturing complexity.
The authors note that traditional designs limit the generator gas temperature to approximately 800–1000 K, while the new scheme is designed for a significantly higher regime.