The design and test of 250N thruster with HAN-based propellant

摘要

The attempt of replacing toxic propellant hydrazine by green propellant has attracted the relevant industry worldwide. HAN-based propellants have emerged as good alternatives to replace the hydrazine propellant because of their relatively lower toxicity, higher density, lower freezing point and higher specific impulses compared to hydrazine, and a lot of papers have reported the achievements in small thrust class like 1N, 5N by using HAN-based propellants, however, few papers have reported the performance of several hundred Newton thrust level thruster by using the green propellants, and relevant study has indicated that the greater thrust level of the engine, the more difficult of the research. Shanghai Institute of Space Propulsion (SISP) has been focusing on the novel technology since the late 1990's and developing different thrust level of thrusters using HAN-based propellant named as HB510, which is a blend of HAN, water, fuel and other additives, and its density is 1.3g/cm3, SISP's efforts of these years have yielded substantial progress in the development of the thruster design, analysis and test technology, and the most important advances have been achieved on 250N thruster recently. It now has achieved an accumulated 400s firing time, 3500 pulses and 50s longest continuous firing time with catalyst bed temperature preheated to 150°C.It delivers a specific impulse performance of 220s (with 50:1 expansion ratio nozzle) and the highest temperature of the thruster obtained is no more than 1150°C during thruster operations in vacuum conditions, and the propellant throughput of the 250N thruster is 51kg. The current status implies that the 250N thruster has reached technology readiness level 5. SISP has found a unique opportunity to demonstrate the green propulsion, thus taking a significant step towards its use in future space applications, especially in launch vehicle system. The achievements of 250N thruster are the results of comprehensive development of propellant formulations, catalyst and thruster design. This paper gives an overview presentation of the research. In addition to the 250N thruster, it lists the performances of the other thrusters developed by using this new propellant and discusses the mechanism of the reaction, which is the key of this new technology.